cli/policy: route check through gRPC; bypass goes direct to DB

policy check previously ran the full policy engine in-process inside
the CLI, building a sandbox PolicyManager from the file and the
database. That duplicated the engine's runtime dependencies onto the
CLI and forced --bypass-grpc-and-access-database-directly to pull in
full server config validation. nblock hit it on PR #3229: passing
--bypass with a real config produced a flood of 'Fatal config error:'
lines from validateServerConfig because the cobra init early-return
for 'policy check' skipped --config registration and OnInitialize.

Make 'policy check' a thin frontend for the new CheckPolicy gRPC
method. The server-side handler builds a fresh PolicyManager from the
request bytes and the state's live users/nodes, runs SetPolicy on the
sandbox so the tests block executes, and returns the result through
gRPC status. No persistence, no policy_mode coupling.

--bypass-grpc-and-access-database-directly keeps doing what its name
says — opens the DB directly for cases where the server is not
running — but is no longer the only way to evaluate a tests block.

Drop the 'policy check' early-return in cmd/headscale/cli/root.go
(added in PR #2580 when check was syntax-only). All paths now need
either gRPC or direct DB access, both of which want the config and
flags the rest of cobra init sets up.

integration/cli_policy_test.go covers the matrix nblock asked about:
policy_mode={file,database} x fixture={acl-only, acl+passing-tests,
acl+failing-tests} x bypass={false,true} = 12 rows. acl-only and
acl-plus-passing-tests must pass; acl-plus-failing-tests must surface
'test(s) failed'; the policy_mode axis proves check does not depend
on where the server stores its current policy.

Updates #1803

.github/workflows/container-main.yml

@@ -59,7 +59,7 @@ jobs:
           nix develop --command -- ko build \
             --bare \
             --platform=linux/amd64,linux/arm64 \
-            --tags=main-${GITHUB_SHA::7} \
+            --tags=main-${GITHUB_SHA::7},development \
             ./cmd/headscale
 
       - name: Push to Docker Hub
@@ -71,7 +71,7 @@ jobs:
           nix develop --command -- ko build \
             --bare \
             --platform=linux/amd64,linux/arm64 \
-            --tags=main-${GITHUB_SHA::7} \
+            --tags=main-${GITHUB_SHA::7},development \
             ./cmd/headscale
 
   binaries:

.github/workflows/gh-action-integration-generator.go

@@ -68,6 +68,7 @@ func findTests() []string {
 	args := []string{
 		"--type", "go",
 		"--regexp", "func (Test.+)\\(.*",
+		"--max-depth", "1",
 		"../../integration/",
 		"--replace", "$1",
 		"--sort", "path",

.github/workflows/needs-more-info-timer.yml

@@ -58,15 +58,16 @@ jobs:
 
             # Find when needs-more-info was last added
             let events = (gh api $"repos/($env.GH_REPO)/issues/($number)/events"
-              --paginate | from json | flatten)
+              --paginate | from json)
             let label_event = ($events
-              | where event == "labeled" and label.name == "needs-more-info"
+              | where event == "labeled"
+              | where label.name == "needs-more-info"
               | last)
             let label_added_at = ($label_event.created_at | into datetime)
 
             # Check for non-bot comments after the label was added
             let comments = (gh api $"repos/($env.GH_REPO)/issues/($number)/comments"
-              --paginate | from json | flatten)
+              --paginate | from json)
             let human_responses = ($comments
               | where user.type != "Bot"
               | where { ($in.created_at | into datetime) > $label_added_at })

.github/workflows/test-integration.yaml

@@ -239,6 +239,7 @@ jobs:
           - TestHASubnetRouterFailover
           - TestSubnetRouteACL
           - TestEnablingExitRoutes
+          - TestExitRoutesWithAutogroupInternetACL
           - TestSubnetRouterMultiNetwork
           - TestSubnetRouterMultiNetworkExitNode
           - TestAutoApproveMultiNetwork/authkey-tag.*
@@ -249,6 +250,10 @@ jobs:
           - TestAutoApproveMultiNetwork/webauth-group.*
           - TestSubnetRouteACLFiltering
           - TestGrantViaSubnetSteering
+          - TestHASubnetRouterPingFailover
+          - TestHASubnetRouterFailoverBothOffline
+          - TestHASubnetRouterFailoverBothOfflineCablePull
+          - TestHASubnetRouterFailoverDockerDisconnect
           - TestHeadscale
           - TestTailscaleNodesJoiningHeadcale
           - TestSSHOneUserToAll
@@ -296,6 +301,7 @@ jobs:
           - TestTagsAuthKeyWithoutUserInheritsTags
           - TestTagsAuthKeyWithoutUserRejectsAdvertisedTags
           - TestTagsAuthKeyConvertToUserViaCLIRegister
+          - TestTailscaleRustAxum
     uses: ./.github/workflows/integration-test-template.yml
     secrets: inherit
     with:

.goreleaser.yml

@@ -42,10 +42,9 @@ source:
     - "vendor/"
 
 nfpms:
-  # Configure nFPM for .deb and .rpm releases
+  # Configure nFPM for .deb releases
   #
-  # See https://nfpm.goreleaser.com/configuration/
-  # and https://goreleaser.com/customization/nfpm/
+  # See https://goreleaser.com/customization/package/nfpm/
   #
   # Useful tools for debugging .debs:
   # List file contents: dpkg -c dist/headscale...deb
@@ -79,6 +78,8 @@ nfpms:
         dst: /usr/lib/systemd/system/headscale.service
       - dst: /var/lib/headscale
         type: dir
+      - src: ./config-example.yaml
+        dst: /usr/share/doc/headscale/examples/config-example.yaml
       - src: LICENSE
         dst: /usr/share/doc/headscale/copyright
     scripts:

.pre-commit-config.yaml

@@ -13,6 +13,7 @@ repos:
     rev: v6.0.0
     hooks:
       - id: check-added-large-files
+        args: [--maxkb=1024]
       - id: check-case-conflict
       - id: check-executables-have-shebangs
       - id: check-json

AGENTS.md

@@ -198,7 +198,7 @@ databases. The `migrationsRequiringFKDisabled` map in
 
 Headscale enforces **tags XOR user ownership**: every node is either
 tagged (owned by tags) or user-owned (owned by a user namespace), never
-both. This is a load-bearing architectural invariant.
+both. This is a load-bearing architectural rule.
 
 - **Use `node.IsTagged()`** (`hscontrol/types/node.go:221`) to determine
   ownership, not `node.UserID().Valid()`. A tagged node may still have

CHANGELOG.md

@@ -27,13 +27,29 @@ A new `headscale auth` CLI command group supports the approval flow:
 [#1850](https://github.com/juanfont/headscale/pull/1850)
 [#3180](https://github.com/juanfont/headscale/pull/3180)
 
+### Policy tests (beta)
+
+Headscale now evaluates the `tests` block in a policy file. Tests assert reachability between
+named sources and destinations and cover the whole policy — both `acls` and `grants` rules
+contribute. They run on user-initiated writes via `headscale policy set`, the file watcher, and
+`headscale policy check`. A failing test rejects the write before it is applied, with the same
+error message Tailscale SaaS would return for the same policy.
+
+Tests do not run at boot. An already-stored policy that no longer passes — for example because a
+referenced user was deleted while the server was offline — logs a warning and the server keeps
+running.
+
+This feature is **beta** while behavioural coverage against Tailscale SaaS broadens.
+
+[#3229](https://github.com/juanfont/headscale/pull/3229)
+
 ### Grants
 
-We now support [Tailscale grants](https://tailscale.com/kb/1324/grants) alongside ACLs. Grants
-extend what you can express in a policy beyond packet filtering: the `app` field controls
-application-level features like Taildrive file sharing and peer relay, and the `via` field steers
-traffic through specific tagged subnet routers or exit nodes. The `ip` field works like an ACL rule.
-Grants can be mixed with ACLs in the same policy file.
+We now support [Tailscale grants](https://tailscale.com/docs/features/access-control/grants)
+alongside ACLs. Grants extend what you can express in a policy beyond packet filtering: the `app`
+field controls application-level features like Taildrive file sharing and peer relay, and the `via`
+field steers traffic through specific tagged subnet routers or exit nodes. The `ip` field works like
+an ACL rule. Grants can be mixed with ACLs in the same policy file.
 [#2180](https://github.com/juanfont/headscale/pull/2180)
 
 As part of this, we added `autogroup:danger-all`. It resolves to `0.0.0.0/0` and `::/0` — all IP
@@ -41,66 +57,154 @@ addresses, including those outside the tailnet. This replaces the old behaviour
 all IPs (see BREAKING below). The name is intentionally scary: accepting traffic from the entire
 internet is a security-sensitive choice. `autogroup:danger-all` can only be used as a source.
 
+### Hostname handling (cleanroom rewrite)
+
+The hostname ingest pipeline has been rewritten to match Tailscale SaaS byte-for-byte.
+Headscale previously had three overlapping regexes and two disagreeing entry points
+(registration vs map-request update), which caused a recurring class of bugs: names
+containing apostrophes, spaces, dots, or non-ASCII characters were alternately rejected
+(dropping updates with log spam) or stored as `invalid-<rand>` surrogates
+([#3188](https://github.com/juanfont/headscale/issues/3188),
+[#2926](https://github.com/juanfont/headscale/issues/2926),
+[#2343](https://github.com/juanfont/headscale/issues/2343),
+[#2762](https://github.com/juanfont/headscale/issues/2762),
+[#2177](https://github.com/juanfont/headscale/issues/2177),
+[#2121](https://github.com/juanfont/headscale/issues/2121),
+[#2449](https://github.com/juanfont/headscale/issues/2449),
+[#363](https://github.com/juanfont/headscale/issues/363)).
+
+What changed:
+
+- Sanitisation and validation now come directly from
+  `tailscale.com/util/dnsname.SanitizeHostname` / `ValidLabel`.
+- Admin rename (`headscale nodes rename`) now validates via `dnsname.ValidLabel` and
+  rejects labels already held by another node (previously coerced invalid input silently).
+
+Examples that previously regressed and now work:
+
+| Input                | Raw (Hostname)       | DNS label (GivenName) |
+| -------------------- | -------------------- | --------------------- |
+| `Joe's Mac mini`     | `Joe's Mac mini`     | `joes-mac-mini`       |
+| `Yuri's MacBook Pro` | `Yuri's MacBook Pro` | `yuris-macbook-pro`   |
+| `Test@Host`          | `Test@Host`          | `test-host`           |
+| `mail.server`        | `mail.server`        | `mail-server`         |
+| `My-PC!`             | `My-PC!`             | `my-pc`               |
+| `我的电脑`           | `我的电脑`           | `node`                |
+
 ### BREAKING
 
-- **ACL Policy**: Wildcard (`*`) in ACL sources and destinations now resolves to Tailscale's CGNAT range (`100.64.0.0/10`) and ULA range (`fd7a:115c:a1e0::/48`) instead of all IPs (`0.0.0.0/0` and `::/0`) [#3036](https://github.com/juanfont/headscale/pull/3036)
+#### Hostname handling
+
+- The `GivenName` collision policy changed from an 8-char random hash suffix (`laptop-abc12xyz`) to a monotonic numeric suffix (`laptop`, `laptop-1`, `laptop-2`, …), matching Tailscale SaaS. Empty / all-non-ASCII hostnames now fall back to the literal `node` instead of `invalid-<rand>`. MagicDNS names change on upgrade for any node whose previous label was a random-suffix form; the raw `Hostname` column is unchanged.
+
+#### ACL Policy
+
+- Wildcard (`*`) in ACL sources and destinations now resolves to Tailscale's CGNAT range (`100.64.0.0/10`) and ULA range (`fd7a:115c:a1e0::/48`) instead of all IPs (`0.0.0.0/0` and `::/0`) [#3036](https://github.com/juanfont/headscale/pull/3036)
   - This better matches Tailscale's security model where `*` means "any node in the tailnet" rather than "any IP address"
   - Policies that need to match all IP addresses including non-Tailscale IPs should use `autogroup:danger-all` as a source, or explicit CIDR ranges as destinations [#2180](https://github.com/juanfont/headscale/pull/2180)
   - `autogroup:danger-all` can only be used as a source; it cannot be used as a destination
   - **Note**: Users with non-standard IP ranges configured in `prefixes.ipv4` or `prefixes.ipv6` (which is unsupported and produces a warning) will need to explicitly specify their CIDR ranges in ACL rules instead of using `*`
-- **ACL Policy**: Validate autogroup:self source restrictions matching Tailscale behavior - tags, hosts, and IPs are rejected as sources for autogroup:self destinations [#3036](https://github.com/juanfont/headscale/pull/3036)
+- Validate autogroup:self source restrictions matching Tailscale behavior - tags, hosts, and IPs are rejected as sources for autogroup:self destinations [#3036](https://github.com/juanfont/headscale/pull/3036)
   - Policies using tags, hosts, or IP addresses as sources for autogroup:self destinations will now fail validation
-- **Upgrade path**: Headscale now enforces a strict version upgrade path [#3083](https://github.com/juanfont/headscale/pull/3083)
+- The `proto:icmp` protocol name now only includes ICMPv4 (protocol 1), matching Tailscale behavior [#3036](https://github.com/juanfont/headscale/pull/3036)
+  - Previously, `proto:icmp` included both ICMPv4 and ICMPv6
+  - Use `proto:ipv6-icmp` or protocol number `58` explicitly for ICMPv6
+
+#### Upgrade Path
+
+- Headscale now enforces a strict version upgrade path [#3083](https://github.com/juanfont/headscale/pull/3083)
   - Skipping minor versions (e.g. 0.27 → 0.29) is blocked; upgrade one minor version at a time
   - Downgrading to a previous minor version is blocked
   - Patch version changes within the same minor are always allowed
-- **ACL Policy**: The `proto:icmp` protocol name now only includes ICMPv4 (protocol 1), matching Tailscale behavior [#3036](https://github.com/juanfont/headscale/pull/3036)
-  - Previously, `proto:icmp` included both ICMPv4 and ICMPv6
-  - Use `proto:ipv6-icmp` or protocol number `58` explicitly for ICMPv6
-- **CLI**: `headscale nodes register` is deprecated in favour of `headscale auth register --auth-id <id> --user <user>` [#1850](https://github.com/juanfont/headscale/pull/1850)
+
+#### CLI
+
+- `headscale nodes register` is deprecated in favour of `headscale auth register --auth-id <id> --user <user>` [#1850](https://github.com/juanfont/headscale/pull/1850)
   - The old command continues to work but will be removed in a future release
 
+### HA subnet router health probing
+
+Headscale now actively probes HA subnet routers to detect nodes that are connected but not
+forwarding traffic. The control plane periodically pings HA subnet routers via the Noise
+control channel and fails over to a healthy standby if the primary stops responding. This is
+enabled by default (`node.routes.ha.probe_interval: 10s`, `probe_timeout: 5s`) and only
+active when HA routes exist (2+ nodes advertising the same prefix). Set `probe_interval` to
+`0` to disable. This complements the existing disconnect-based failover, catching "zombie
+connected" routers that maintain their control session but cannot route packets.
+
 ### Changes
 
-- **OIDC registration**: Add a confirmation page before completing node registration, showing the device hostname and machine key fingerprint [#3180](https://github.com/juanfont/headscale/pull/3180)
-- **Debug endpoints**: Omit secret fields (`Pass`, `ClientSecret`, `APIKey`) from `/debug/config` JSON output [#3180](https://github.com/juanfont/headscale/pull/3180)
-- **Debug endpoints**: Route `statsviz` through `tsweb.Protected` [#3180](https://github.com/juanfont/headscale/pull/3180)
-- Remove gRPC reflection from the remote (TCP) server [#3180](https://github.com/juanfont/headscale/pull/3180)
-- **Node Expiry**: Add `node.expiry` configuration option to set a default node key expiry for nodes registered via auth key [#3122](https://github.com/juanfont/headscale/pull/3122)
-  - Tagged nodes (registered with tagged pre-auth keys) are exempt from default expiry
-  - `oidc.expiry` has been removed; use `node.expiry` instead (applies to all registration methods including OIDC)
-  - `ephemeral_node_inactivity_timeout` is deprecated in favour of `node.ephemeral.inactivity_timeout`
-- **SSH Policy**: Add support for `localpart:*@<domain>` in SSH rule `users` field, mapping each matching user's email local-part as their OS username [#3091](https://github.com/juanfont/headscale/pull/3091)
-- **ACL Policy**: Add ICMP and IPv6-ICMP protocols to default filter rules when no protocol is specified [#3036](https://github.com/juanfont/headscale/pull/3036)
-- **ACL Policy**: Fix autogroup:self handling for tagged nodes - tagged nodes no longer incorrectly receive autogroup:self filter rules [#3036](https://github.com/juanfont/headscale/pull/3036)
-- **ACL Policy**: Use CIDR format for autogroup:self destination IPs matching Tailscale behavior [#3036](https://github.com/juanfont/headscale/pull/3036)
-- **ACL Policy**: Merge filter rules with identical SrcIPs and IPProto matching Tailscale behavior - multiple ACL rules with the same source now produce a single FilterRule with combined DstPorts [#3036](https://github.com/juanfont/headscale/pull/3036)
-- Remove deprecated `--namespace` flag from `nodes list`, `nodes register`, and `debug create-node` commands (use `--user` instead) [#3093](https://github.com/juanfont/headscale/pull/3093)
-- Remove deprecated `namespace`/`ns` command aliases for `users` and `machine`/`machines` aliases for `nodes` [#3093](https://github.com/juanfont/headscale/pull/3093)
-- Add SSH `check` action support with OIDC and CLI-based approval flows [#1850](https://github.com/juanfont/headscale/pull/1850)
-- Add `headscale auth register`, `headscale auth approve`, and `headscale auth reject` CLI commands [#1850](https://github.com/juanfont/headscale/pull/1850)
-- Add `auth` related routes to the API. The `auth/register` endpoint now expects data as JSON [#1850](https://github.com/juanfont/headscale/pull/1850)
-- Deprecate `headscale nodes register --key` in favour of `headscale auth register --auth-id` [#1850](https://github.com/juanfont/headscale/pull/1850)
-- Generalise auth templates into reusable `AuthSuccess` and `AuthWeb` components [#1850](https://github.com/juanfont/headscale/pull/1850)
-- Unify auth pipeline with `AuthVerdict` type, supporting registration, reauthentication, and SSH checks [#1850](https://github.com/juanfont/headscale/pull/1850)
-- Add support for policy grants with `ip`, `app`, and `via` fields [#2180](https://github.com/juanfont/headscale/pull/2180)
-- Add `autogroup:danger-all` as a source-only autogroup resolving to all IP addresses [#2180](https://github.com/juanfont/headscale/pull/2180)
-- Add capability grants for Taildrive (`cap/drive`) and peer relay (`cap/relay`) with automatic companion capabilities [#2180](https://github.com/juanfont/headscale/pull/2180)
-- Add per-viewer via route steering — grants with `via` tags control which subnet router or exit node handles traffic for each group of viewers [#2180](https://github.com/juanfont/headscale/pull/2180)
-- Enable Taildrive node attributes on all nodes; actual access is controlled by `cap/drive` grants [#2180](https://github.com/juanfont/headscale/pull/2180)
-- Fix exit nodes incorrectly receiving filter rules for destinations that only overlap via exit routes [#2180](https://github.com/juanfont/headscale/pull/2180)
+#### ACL Policy
+
+- Fix subnet-to-subnet peer visibility — subnet routers now correctly become peers when ACL rules reference only subnet CIDRs as sources, without requiring node IP rules [#3175](https://github.com/juanfont/headscale/pull/3175)
+- Fix filter rule reduction to use only approved subnet routes instead of all advertised routes, matching Tailscale SaaS behavior [#3175](https://github.com/juanfont/headscale/pull/3175)
+- Add ICMP and IPv6-ICMP protocols to default filter rules when no protocol is specified [#3036](https://github.com/juanfont/headscale/pull/3036)
+- Fix autogroup:self handling for tagged nodes - tagged nodes no longer incorrectly receive autogroup:self filter rules [#3036](https://github.com/juanfont/headscale/pull/3036)
+- Use CIDR format for autogroup:self destination IPs matching Tailscale behavior [#3036](https://github.com/juanfont/headscale/pull/3036)
+- Merge filter rules with identical SrcIPs and IPProto matching Tailscale behavior - multiple ACL rules with the same source now produce a single FilterRule with combined DstPorts [#3036](https://github.com/juanfont/headscale/pull/3036)
+- Fix exit nodes incorrectly receiving filter rules for destinations that only overlap via exit routes [#3169](https://github.com/juanfont/headscale/issues/3169) [#3175](https://github.com/juanfont/headscale/pull/3175)
 - Fix address-based aliases (hosts, raw IPs) incorrectly expanding to include the matching node's other address family [#2180](https://github.com/juanfont/headscale/pull/2180)
 - Fix identity-based aliases (tags, users, groups) resolving to IPv4 only; they now include both IPv4 and IPv6 matching Tailscale behavior [#2180](https://github.com/juanfont/headscale/pull/2180)
 - Fix wildcard (`*`) source in ACLs now using actually-approved subnet routes instead of autoApprover policy prefixes [#2180](https://github.com/juanfont/headscale/pull/2180)
 - Fix non-wildcard source IPs being dropped when combined with wildcard `*` in the same ACL rule [#2180](https://github.com/juanfont/headscale/pull/2180)
 - Fix exit node approval not triggering filter rule recalculation for peers [#2180](https://github.com/juanfont/headscale/pull/2180)
 - Policy validation error messages now include field context (e.g., `src=`, `dst=`) and are more descriptive [#2180](https://github.com/juanfont/headscale/pull/2180)
+- Reject policies whose `user@` tokens match multiple DB users; rename the duplicate via `headscale users rename` to load [#3160](https://github.com/juanfont/headscale/issues/3160)
+- Evaluate the policy `tests` block on user-initiated writes across both `acls` and `grants`; reject policies whose tests fail (beta) [#1803](https://github.com/juanfont/headscale/issues/1803)
 
-## 0.28.1 (202x-xx-xx)
+#### Grants
 
-### Changes
+- Add support for policy grants with `ip`, `app`, and `via` fields [#2180](https://github.com/juanfont/headscale/pull/2180)
+- Add `autogroup:danger-all` as a source-only autogroup resolving to all IP addresses [#2180](https://github.com/juanfont/headscale/pull/2180)
+- Add capability grants for Taildrive (`cap/drive`) and peer relay (`cap/relay`) with automatic companion capabilities [#2180](https://github.com/juanfont/headscale/pull/2180)
+- Add per-viewer via route steering — grants with `via` tags control which subnet router or exit node handles traffic for each group of viewers [#2180](https://github.com/juanfont/headscale/pull/2180)
+- Enable Taildrive node attributes on all nodes; actual access is controlled by `cap/drive` grants [#2180](https://github.com/juanfont/headscale/pull/2180)
 
+#### SSH Policy
+
+- Add support for `localpart:*@<domain>` in SSH rule `users` field, mapping each matching user's email local-part as their OS username [#3091](https://github.com/juanfont/headscale/pull/3091)
+- Add SSH `check` action support with OIDC and CLI-based approval flows [#1850](https://github.com/juanfont/headscale/pull/1850)
+
+#### CLI
+
+- Add `headscale auth register`, `headscale auth approve`, and `headscale auth reject` CLI commands [#1850](https://github.com/juanfont/headscale/pull/1850)
+- Deprecate `headscale nodes register --key` in favour of `headscale auth register --auth-id` [#1850](https://github.com/juanfont/headscale/pull/1850)
+- `headscale policy check --bypass-grpc-and-access-database-directly` validates `user@` tokens against the live user database [#3160](https://github.com/juanfont/headscale/issues/3160)
+- Remove deprecated `--namespace` flag from `nodes list`, `nodes register`, and `debug create-node` commands (use `--user` instead) [#3093](https://github.com/juanfont/headscale/pull/3093)
+- Remove deprecated `namespace`/`ns` command aliases for `users` and `machine`/`machines` aliases for `nodes` [#3093](https://github.com/juanfont/headscale/pull/3093)
 - **User deletion**: Fix `DestroyUser` deleting all pre-auth keys in the database instead of only the target user's keys [#3155](https://github.com/juanfont/headscale/pull/3155)
+- `headscale policy check` evaluates the `tests` block when invoked with `--bypass-grpc-and-access-database-directly`; without the flag it warns instead of running the tests against empty data [#1803](https://github.com/juanfont/headscale/issues/1803)
+
+#### API
+
+- Add `auth` related routes. The `auth/register` endpoint now expects data as JSON [#1850](https://github.com/juanfont/headscale/pull/1850)
+- Remove gRPC reflection from the remote (TCP) server [#3180](https://github.com/juanfont/headscale/pull/3180)
+
+#### OIDC
+
+- Add a confirmation page before completing node registration, showing the device hostname and machine key fingerprint [#3180](https://github.com/juanfont/headscale/pull/3180)
+- Generalise auth templates into reusable `AuthSuccess` and `AuthWeb` components [#1850](https://github.com/juanfont/headscale/pull/1850)
+- Unify auth pipeline with `AuthVerdict` type, supporting registration, reauthentication, and SSH checks [#1850](https://github.com/juanfont/headscale/pull/1850)
+
+#### Configuration
+
+- Add `node.expiry` configuration option to set a default node key expiry for nodes registered via auth key [#3122](https://github.com/juanfont/headscale/pull/3122)
+  - Tagged nodes (registered with tagged pre-auth keys) are exempt from default expiry
+  - `oidc.expiry` has been removed; use `node.expiry` instead (applies to all registration methods including OIDC)
+  - `ephemeral_node_inactivity_timeout` is deprecated in favour of `node.ephemeral.inactivity_timeout`
+
+#### Debug
+
+- Add node connectivity ping page for verifying control-plane reachability [#3183](https://github.com/juanfont/headscale/pull/3183)
+- Omit secret fields (`Pass`, `ClientSecret`, `APIKey`) from `/debug/config` JSON output [#3180](https://github.com/juanfont/headscale/pull/3180)
+- Route `statsviz` through `tsweb.Protected` [#3180](https://github.com/juanfont/headscale/pull/3180)
+
+#### Other
+
+- Remove old migrations for the debian package [#3185](https://github.com/juanfont/headscale/pull/3185)
+- Install `config-example.yaml` as example for the debian package [#3186](https://github.com/juanfont/headscale/pull/3186)
+- **Node Expiry**: Fix user owned re registration with zero client expiry and no default storing `0001-01-01 00:00:00` in the database instead of NULL [#3199](https://github.com/juanfont/headscale/pull/3199)
+  - Pre-existing rows with `0001-01-01 00:00:00` are not backfilled; they clear themselves the next time the node re-registers
 
 ## 0.28.0 (2026-02-04)
 
@@ -111,7 +215,7 @@ internet is a security-sensitive choice. `autogroup:danger-all` can only be used
 Tags are now implemented following the Tailscale model where tags and user ownership are mutually exclusive. Devices can be either
 user-owned (authenticated via web/OIDC) or tagged (authenticated via tagged PreAuthKeys). Tagged devices receive their identity from
 tags rather than users, making them suitable for servers and infrastructure. Applying a tag to a device removes user-based
-ownership. See the [Tailscale tags documentation](https://tailscale.com/kb/1068/tags) for details on how tags work.
+ownership. See the [Tailscale tags documentation](https://tailscale.com/docs/features/tags) for details on how tags work.
 
 User-owned nodes can now request tags during registration using `--advertise-tags`. Tags are validated against the `tagOwners` policy
 and applied at registration time. Tags can be managed via the CLI or API after registration. Tagged nodes can return to user-owned
@@ -210,7 +314,7 @@ sequentially through each stable release, selecting the latest patch version ava
 
 - **SSH Policy**: SSH source/destination validation now enforces Tailscale's security model [#3010](https://github.com/juanfont/headscale/issues/3010)
 
-  Per [Tailscale SSH documentation](https://tailscale.com/kb/1193/tailscale-ssh), the following rules are now enforced:
+  Per [Tailscale SSH documentation](https://tailscale.com/docs/features/tailscale-ssh), the following rules are now enforced:
   1. **Tags cannot SSH to user-owned devices**: SSH rules with `tag:*` or `autogroup:tagged` as source cannot have username destinations (e.g., `alice@`) or `autogroup:member`/`autogroup:self` as destination
   2. **Username destinations require same-user source**: If destination is a specific username (e.g., `alice@`), the source must be that exact same user only. Use `autogroup:self` for same-user SSH access instead
 
@@ -339,8 +443,8 @@ DERPMap updates when upstream is changed.
 
 This release adds support for the three missing autogroups: `self`
 (experimental), `member`, and `tagged`. Please refer to the
-[documentation](https://tailscale.com/kb/1018/autogroups/) for a detailed
-explanation.
+[documentation](https://tailscale.com/docs/reference/targets-and-selectors#autogroups)
+for a detailed explanation.
 
 `autogroup:self` is marked as experimental and should be used with caution, but
 we need help testing it. Experimental here means two things; first, generating
@@ -503,7 +607,7 @@ The SSH policy has been reworked to be more consistent with the rest of the
 policy. In addition, several inconsistencies between our implementation and
 Tailscale's upstream has been closed and this might be a breaking change for
 some users. Please refer to the
-[upstream documentation](https://tailscale.com/kb/1337/acl-syntax#tailscale-ssh)
+[upstream documentation](https://tailscale.com/docs/reference/syntax/policy-file#tailscale-ssh)
 for more information on which types are allowed in `src`, `dst` and `users`.
 
 There is one large inconsistency left, we allow `*` as a destination as we
@@ -1017,7 +1121,7 @@ part of adopting [#1460](https://github.com/juanfont/headscale/pull/1460).
 
 - Added support for Tailscale TS2021 protocol [#738](https://github.com/juanfont/headscale/pull/738)
 - Add experimental support for
-  [SSH ACL](https://tailscale.com/kb/1018/acls/#tailscale-ssh) (see docs for
+  [SSH ACL](https://tailscale.com/docs/reference/syntax/policy-file#tailscale-ssh) (see docs for
   limitations) [#847](https://github.com/juanfont/headscale/pull/847)
   - Please note that this support should be considered _partially_ implemented
   - SSH ACLs status:
@@ -1094,7 +1198,7 @@ part of adopting [#1460](https://github.com/juanfont/headscale/pull/1460).
 ### BREAKING
 
 - Old ACL syntax is no longer supported ("users" & "ports" -> "src" & "dst").
-  Please check [the new syntax](https://tailscale.com/kb/1018/acls/).
+  Please check [the new syntax](https://tailscale.com/docs/features/access-control/acls).
 
 ### Changes
 
@@ -1124,7 +1228,7 @@ part of adopting [#1460](https://github.com/juanfont/headscale/pull/1460).
 - Add -c option to specify config file from command line [#285](https://github.com/juanfont/headscale/issues/285)
   [#612](https://github.com/juanfont/headscale/pull/601)
 - Add configuration option to allow Tailscale clients to use a random WireGuard
-  port. [kb/1181/firewalls](https://tailscale.com/kb/1181/firewalls)
+  port. [Tailscale docs](https://tailscale.com/docs/reference/syntax/policy-file#randomizeclientport)
   [#624](https://github.com/juanfont/headscale/pull/624)
 - Improve obtuse UX regarding missing configuration
   (`ephemeral_node_inactivity_timeout` not set)

Dockerfile.derper

@@ -1,6 +1,6 @@
 # For testing purposes only
 
-FROM golang:1.26.2-alpine AS build-env
+FROM golang:1.26.3-alpine AS build-env
 
 WORKDIR /go/src
 

Dockerfile.tailscale-HEAD

@@ -4,7 +4,7 @@
 # This Dockerfile is more or less lifted from tailscale/tailscale
 # to ensure a similar build process when testing the HEAD of tailscale.
 
-FROM golang:1.26.2-alpine AS build-env
+FROM golang:1.26.3-alpine AS build-env
 
 WORKDIR /go/src
 

Dockerfile.tailscale-rs

@@ -0,0 +1,26 @@
+FROM rust:1.94-bookworm AS builder
+
+ARG TAILSCALE_RS_REPO=https://github.com/tailscale/tailscale-rs.git
+ARG TAILSCALE_RS_REF=main
+
+WORKDIR /app
+RUN git clone --depth 1 --branch "$TAILSCALE_RS_REF" "$TAILSCALE_RS_REPO" .
+
+# Re-export ts_control's insecure-keyfetch feature through the tailscale
+# crate so the axum example can fetch the headscale control key over
+# plain HTTP. The integration harness serves the control plane without
+# TLS, and upstream only allows plain-HTTP key fetches when this Cargo
+# feature is compiled in.
+RUN sed -i '/^axum = \["dep:axum"\]/a insecure-keyfetch = ["ts_control/insecure-keyfetch"]' Cargo.toml
+
+RUN cargo build --release --features axum,insecure-keyfetch --example axum
+
+FROM debian:bookworm-slim
+
+RUN apt-get update && \
+    apt-get install -y --no-install-recommends \
+    ca-certificates \
+    iproute2 \
+    && rm -rf /var/lib/apt/lists/*
+
+COPY --from=builder /app/target/release/examples/axum /usr/local/bin/axum

Makefile

@@ -105,6 +105,11 @@ clean:
 .PHONY: dev
 dev: fmt lint test build
 
+# Start a local headscale dev server (use mts to add nodes)
+.PHONY: dev-server
+dev-server:
+	go run ./cmd/dev
+
 # Help target
 .PHONY: help
 help:

README.md

@@ -30,8 +30,8 @@ nodes in the Tailscale network. It assigns the IP addresses of the clients,
 creates the boundaries between each user, enables sharing machines between users,
 and exposes the advertised routes of your nodes.
 
-A [Tailscale network (tailnet)](https://tailscale.com/kb/1136/tailnet/) is private
-network which Tailscale assigns to a user in terms of private users or an
+A [Tailscale network (tailnet)](https://tailscale.com/docs/concepts/tailnet) is
+private network which Tailscale assigns to a user in terms of private users or an
 organisation.
 
 ## Design goal

cmd/dev/README.md

@@ -0,0 +1,96 @@
+# cmd/dev -- Local Development Environment
+
+Starts a headscale server on localhost with a pre-created user and
+pre-auth key. Pair with `mts` to add real tailscale nodes.
+
+## Quick start
+
+```bash
+# Terminal 1: start headscale
+go run ./cmd/dev
+
+# Terminal 2: start mts server
+go tool mts server run
+
+# Terminal 3: add and connect nodes
+go tool mts server add node1
+go tool mts server add node2
+
+# Disable logtail (avoids startup delays, see "Known issues" below)
+for n in node1 node2; do
+  cat > ~/.config/multi-tailscale-dev/$n/env.txt << 'EOF'
+TS_NO_LOGS_NO_SUPPORT=true
+EOF
+done
+
+# Restart nodes so env.txt takes effect
+go tool mts server stop node1 && go tool mts server start node1
+go tool mts server stop node2 && go tool mts server start node2
+
+# Connect to headscale (use the auth key printed by cmd/dev)
+go tool mts node1 up --login-server=http://127.0.0.1:8080 --authkey=<KEY> --reset
+go tool mts node2 up --login-server=http://127.0.0.1:8080 --authkey=<KEY> --reset
+
+# Verify
+go tool mts node1 status
+```
+
+## Flags
+
+| Flag     | Default | Description                  |
+| -------- | ------- | ---------------------------- |
+| `--port` | 8080    | Headscale listen port        |
+| `--keep` | false   | Keep state directory on exit |
+
+The metrics/debug port is `port + 1010` (default 9090) and the gRPC
+port is `port + 42363` (default 50443).
+
+## What it does
+
+1. Builds the headscale binary into a temp directory
+2. Writes a minimal dev config (SQLite, public DERP, debug logging)
+3. Starts `headscale serve` as a subprocess
+4. Creates a "dev" user and a reusable 24h pre-auth key via the CLI
+5. Prints a banner with server URL, auth key, and usage instructions
+6. Blocks until Ctrl+C, then kills headscale
+
+State lives in `/tmp/headscale-dev-*/`. Pass `--keep` to preserve it
+across restarts (useful for inspecting the database or reusing keys).
+
+## Useful endpoints
+
+- `http://127.0.0.1:8080/health` -- health check
+- `http://127.0.0.1:9090/debug/ping` -- interactive ping UI
+- `http://127.0.0.1:9090/debug/ping?node=1` -- quick-ping a node
+- `POST http://127.0.0.1:9090/debug/ping` with `node=<id>` -- trigger ping
+
+## Managing headscale
+
+The banner prints the full path to the built binary and config. Use it
+for any headscale CLI command:
+
+```bash
+/tmp/headscale-dev-*/headscale -c /tmp/headscale-dev-*/config.yaml nodes list
+/tmp/headscale-dev-*/headscale -c /tmp/headscale-dev-*/config.yaml users list
+```
+
+## Known issues
+
+### Logtail delays on mts nodes
+
+Freshly created `mts` instances may take 30+ seconds to start if
+`~/.local/share/tailscale/` contains stale logtail cache from previous
+tailscaled runs. The daemon blocks trying to upload old logs before
+creating its socket.
+
+Fix: write `TS_NO_LOGS_NO_SUPPORT=true` to each instance's `env.txt`
+before starting (or restart after writing). See the quick start above.
+
+### mts node cleanup
+
+`mts` stores state in `~/.config/multi-tailscale-dev/`. Old instances
+accumulate over time. Clean them with:
+
+```bash
+go tool mts server rm <name>
+```

cmd/dev/main.go

@@ -0,0 +1,314 @@
+// cmd/dev starts a local headscale development server with a pre-created
+// user and pre-auth key, ready for connecting tailscale nodes via mts.
+package main
+
+import (
+	"context"
+	"encoding/json"
+	"errors"
+	"flag"
+	"fmt"
+	"log"
+	"net/http"
+	"os"
+	"os/exec"
+	"os/signal"
+	"path/filepath"
+	"strconv"
+	"syscall"
+	"time"
+)
+
+var (
+	port = flag.Int("port", 8080, "headscale listen port")
+	keep = flag.Bool("keep", false, "keep state directory on exit")
+)
+
+var errHealthTimeout = errors.New("health check timed out")
+
+var errEmptyAuthKey = errors.New("empty auth key in response")
+
+// maxDevPort is the highest --port value that keeps both the derived
+// metrics port (port+1010) and gRPC port (port+42363) inside the valid
+// 1..65535 TCP range.
+const maxDevPort = 23172
+
+const devConfig = `---
+server_url: http://127.0.0.1:%d
+listen_addr: 127.0.0.1:%d
+metrics_listen_addr: 127.0.0.1:%d
+grpc_listen_addr: 127.0.0.1:%d
+grpc_allow_insecure: true
+
+noise:
+  private_key_path: %s/noise_private.key
+
+prefixes:
+  v4: 100.64.0.0/10
+  v6: fd7a:115c:a1e0::/48
+  allocation: sequential
+
+database:
+  type: sqlite
+  sqlite:
+    path: %s/db.sqlite
+    write_ahead_log: true
+
+derp:
+  server:
+    enabled: false
+  urls:
+    - https://controlplane.tailscale.com/derpmap/default
+  auto_update_enabled: false
+
+dns:
+  magic_dns: true
+  base_domain: headscale.dev
+  override_local_dns: false
+
+log:
+  level: debug
+  format: text
+
+policy:
+  mode: database
+
+unix_socket: %s/headscale.sock
+unix_socket_permission: "0770"
+`
+
+func main() {
+	flag.Parse()
+	log.SetFlags(0)
+
+	if *port < 1 || *port > maxDevPort {
+		log.Fatalf(
+			"--port must be in 1..%d (higher values overflow the derived gRPC port); got %d",
+			maxDevPort, *port,
+		)
+	}
+
+	http.DefaultClient.Timeout = 2 * time.Second
+	http.DefaultClient.CheckRedirect = func(*http.Request, []*http.Request) error {
+		return http.ErrUseLastResponse
+	}
+
+	err := run()
+	if err != nil {
+		log.Fatal(err)
+	}
+}
+
+func run() error {
+	metricsPort := *port + 1010 // default 9090
+	grpcPort := *port + 42363   // default 50443
+
+	tmpDir, err := os.MkdirTemp("", "headscale-dev-")
+	if err != nil {
+		return fmt.Errorf("creating temp dir: %w", err)
+	}
+
+	if !*keep {
+		defer os.RemoveAll(tmpDir)
+	}
+
+	// Write config.
+	configPath := filepath.Join(tmpDir, "config.yaml")
+	configContent := fmt.Sprintf(devConfig,
+		*port, *port, metricsPort, grpcPort,
+		tmpDir, tmpDir, tmpDir,
+	)
+
+	err = os.WriteFile(configPath, []byte(configContent), 0o600)
+	if err != nil {
+		return fmt.Errorf("writing config: %w", err)
+	}
+
+	// Build headscale.
+	fmt.Println("Building headscale...")
+
+	hsBin := filepath.Join(tmpDir, "headscale")
+
+	ctx, stop := signal.NotifyContext(context.Background(), syscall.SIGINT, syscall.SIGTERM)
+	defer stop()
+
+	build := exec.CommandContext(ctx, "go", "build", "-o", hsBin, "./cmd/headscale")
+	build.Stdout = os.Stdout
+	build.Stderr = os.Stderr
+
+	err = build.Run()
+	if err != nil {
+		return fmt.Errorf("building headscale: %w", err)
+	}
+
+	// Start headscale serve.
+	fmt.Println("Starting headscale server...")
+
+	serve := exec.CommandContext(ctx, hsBin, "serve", "-c", configPath)
+	serve.Stdout = os.Stdout
+	serve.Stderr = os.Stderr
+
+	err = serve.Start()
+	if err != nil {
+		return fmt.Errorf("starting headscale: %w", err)
+	}
+
+	// Wait for server to be ready.
+	healthURL := fmt.Sprintf("http://127.0.0.1:%d/health", *port)
+
+	err = waitForHealth(ctx, healthURL, 30*time.Second)
+	if err != nil {
+		return fmt.Errorf("waiting for headscale: %w", err)
+	}
+
+	// Create user.
+	fmt.Println("Creating user and pre-auth key...")
+
+	userJSON, err := runHS(ctx, hsBin, configPath, "users", "create", "dev", "-o", "json")
+	if err != nil {
+		return fmt.Errorf("creating user: %w", err)
+	}
+
+	userID, err := extractUserID(userJSON)
+	if err != nil {
+		return fmt.Errorf("parsing user: %w", err)
+	}
+
+	// Create pre-auth key.
+	keyJSON, err := runHS(
+		ctx, hsBin, configPath,
+		"preauthkeys", "create",
+		"-u", strconv.FormatUint(userID, 10),
+		"--reusable",
+		"-e", "24h",
+		"-o", "json",
+	)
+	if err != nil {
+		return fmt.Errorf("creating pre-auth key: %w", err)
+	}
+
+	authKey, err := extractAuthKey(keyJSON)
+	if err != nil {
+		return fmt.Errorf("parsing pre-auth key: %w", err)
+	}
+
+	// Print banner.
+	fmt.Printf(`
+=== Headscale Dev Environment ===
+  Server:  http://127.0.0.1:%d
+  Metrics: http://127.0.0.1:%d
+  Debug:   http://127.0.0.1:%d/debug/ping
+  Config:  %s
+  State:   %s
+
+Pre-auth key: %s
+
+Connect nodes with mts:
+  go tool mts server run                  # start mts (once, another terminal)
+  go tool mts server add node1            # create a node
+  go tool mts node1 up --login-server=http://127.0.0.1:%d --authkey=%s
+  go tool mts node1 status                # check connection
+
+Manage headscale:
+  %s -c %s nodes list
+  %s -c %s users list
+
+Press Ctrl+C to stop.
+`,
+		*port, metricsPort, metricsPort,
+		configPath, tmpDir,
+		authKey,
+		*port, authKey,
+		hsBin, configPath,
+		hsBin, configPath,
+	)
+
+	// Wait for headscale to exit.
+	err = serve.Wait()
+	if err != nil {
+		// Context cancellation is expected on Ctrl+C.
+		if ctx.Err() != nil {
+			fmt.Println("\nShutting down...")
+
+			return nil
+		}
+
+		return fmt.Errorf("headscale exited: %w", err)
+	}
+
+	return nil
+}
+
+// waitForHealth polls the health endpoint until it returns 200 or the
+// timeout expires.
+func waitForHealth(ctx context.Context, url string, timeout time.Duration) error {
+	deadline := time.Now().Add(timeout)
+
+	for time.Now().Before(deadline) {
+		if ctx.Err() != nil {
+			return ctx.Err()
+		}
+
+		req, err := http.NewRequestWithContext(ctx, http.MethodGet, url, nil)
+		if err != nil {
+			return fmt.Errorf("creating request: %w", err)
+		}
+
+		resp, err := http.DefaultClient.Do(req)
+		if err == nil {
+			resp.Body.Close()
+
+			if resp.StatusCode == http.StatusOK {
+				return nil
+			}
+		}
+
+		// Busy-wait is acceptable for a dev tool polling a local server.
+		time.Sleep(200 * time.Millisecond) //nolint:forbidigo
+	}
+
+	return errHealthTimeout
+}
+
+// runHS executes a headscale CLI command and returns its stdout.
+func runHS(ctx context.Context, bin, config string, args ...string) ([]byte, error) {
+	fullArgs := append([]string{"-c", config}, args...)
+	cmd := exec.CommandContext(ctx, bin, fullArgs...)
+	cmd.Stderr = os.Stderr
+
+	return cmd.Output()
+}
+
+// extractUserID parses the JSON output of "users create" and returns the
+// user ID.
+func extractUserID(data []byte) (uint64, error) {
+	var user struct {
+		ID uint64 `json:"id"`
+	}
+
+	err := json.Unmarshal(data, &user)
+	if err != nil {
+		return 0, fmt.Errorf("unmarshalling user JSON: %w (raw: %s)", err, data)
+	}
+
+	return user.ID, nil
+}
+
+// extractAuthKey parses the JSON output of "preauthkeys create" and
+// returns the key string.
+func extractAuthKey(data []byte) (string, error) {
+	var key struct {
+		Key string `json:"key"`
+	}
+
+	err := json.Unmarshal(data, &key)
+	if err != nil {
+		return "", fmt.Errorf("unmarshalling key JSON: %w (raw: %s)", err, data)
+	}
+
+	if key.Key == "" {
+		return "", errEmptyAuthKey
+	}
+
+	return key.Key, nil
+}

cmd/headscale/cli/api_key.go

@@ -81,7 +81,7 @@ var createAPIKeyCmd = &cobra.Command{
 	Long: `
 Creates a new Api key, the Api key is only visible on creation
 and cannot be retrieved again.
-If you loose a key, create a new one and revoke (expire) the old one.`,
+If you lose a key, create a new one and revoke (expire) the old one.`,
 	Aliases: []string{"c", "new"},
 	RunE: grpcRunE(func(ctx context.Context, client v1.HeadscaleServiceClient, cmd *cobra.Command, args []string) error {
 		expiration, err := expirationFromFlag(cmd)

cmd/headscale/cli/nodes.go

@@ -175,8 +175,10 @@ Use --disable to disable key expiry (node will never expire).`,
 		now := time.Now()
 
 		expiryTime := now
+
 		if expiry != "" {
 			var err error
+
 			expiryTime, err = time.Parse(time.RFC3339, expiry)
 			if err != nil {
 				return fmt.Errorf("parsing expiry time: %w", err)
@@ -397,6 +399,7 @@ func nodesToPtables(
 		}
 
 		var ipBuilder strings.Builder
+
 		for _, addr := range node.GetIpAddresses() {
 			ip, err := netip.ParseAddr(addr)
 			if err == nil {

cmd/headscale/cli/policy.go

@@ -48,6 +48,7 @@ func init() {
 	policyCmd.AddCommand(setPolicy)
 
 	checkPolicy.Flags().StringP("file", "f", "", "Path to a policy file in HuJSON format")
+	checkPolicy.Flags().BoolP(bypassFlag, "", false, "Open the database directly (no gRPC, no running server) to validate user@ token references and to evaluate the policy's tests block. Required when those checks are needed.")
 	mustMarkRequired(checkPolicy, "file")
 	policyCmd.AddCommand(checkPolicy)
 }
@@ -63,6 +64,7 @@ var getPolicy = &cobra.Command{
 	Aliases: []string{"show", "view", "fetch"},
 	RunE: func(cmd *cobra.Command, args []string) error {
 		var policyData string
+
 		if bypass, _ := cmd.Flags().GetBool(bypassFlag); bypass {
 			if !confirmAction(cmd, "DO NOT run this command if an instance of headscale is running, are you sure headscale is not running?") {
 				return errAborted
@@ -169,6 +171,11 @@ var setPolicy = &cobra.Command{
 var checkPolicy = &cobra.Command{
 	Use:   "check",
 	Short: "Check the Policy file for errors",
+	Long: `
+	Check validates the policy against the server's live users and nodes,
+	running any "tests" block. By default the command is a thin frontend
+	for a gRPC call to a running headscale; pass --` + bypassFlag + ` to
+	open the database directly when headscale is not running.`,
 	RunE: func(cmd *cobra.Command, args []string) error {
 		policyPath, _ := cmd.Flags().GetString("file")
 
@@ -177,9 +184,56 @@ var checkPolicy = &cobra.Command{
 			return fmt.Errorf("reading policy file: %w", err)
 		}
 
-		_, err = policy.NewPolicyManager(policyBytes, nil, views.Slice[types.NodeView]{})
+		if bypass, _ := cmd.Flags().GetBool(bypassFlag); bypass {
+			if !confirmAction(cmd, "DO NOT run this command if an instance of headscale is running, are you sure headscale is not running?") {
+				return errAborted
+			}
+
+			d, err := bypassDatabase()
+			if err != nil {
+				return err
+			}
+			defer d.Close()
+
+			users, err := d.ListUsers()
+			if err != nil {
+				return fmt.Errorf("loading users: %w", err)
+			}
+
+			nodes, err := d.ListNodes()
+			if err != nil {
+				return fmt.Errorf("loading nodes: %w", err)
+			}
+
+			// NewPolicyManager validates structure and user references
+			// but intentionally skips test evaluation (boot path).
+			// SetPolicy is the user-write boundary and is what runs the
+			// tests block.
+			pm, err := policy.NewPolicyManager(policyBytes, users, nodes.ViewSlice())
+			if err != nil {
+				return fmt.Errorf("parsing policy file: %w", err)
+			}
+
+			_, err = pm.SetPolicy(policyBytes)
+			if err != nil {
+				return err
+			}
+
+			fmt.Println("Policy is valid")
+
+			return nil
+		}
+
+		ctx, client, conn, cancel, err := newHeadscaleCLIWithConfig()
 		if err != nil {
-			return fmt.Errorf("parsing policy file: %w", err)
+			return fmt.Errorf("connecting to headscale: %w", err)
+		}
+		defer cancel()
+		defer conn.Close()
+
+		_, err = client.CheckPolicy(ctx, &v1.CheckPolicyRequest{Policy: string(policyBytes)})
+		if err != nil {
+			return err
 		}
 
 		fmt.Println("Policy is valid")

cmd/headscale/cli/root.go

@@ -3,7 +3,6 @@ package cli
 import (
 	"os"
 	"runtime"
-	"slices"
 	"strings"
 
 	"github.com/juanfont/headscale/hscontrol/types"
@@ -22,11 +21,6 @@ func init() {
 		return
 	}
 
-	if slices.Contains(os.Args, "policy") && slices.Contains(os.Args, "check") {
-		zerolog.SetGlobalLevel(zerolog.Disabled)
-		return
-	}
-
 	cobra.OnInitialize(initConfig)
 	rootCmd.PersistentFlags().
 		StringVarP(&cfgFile, "config", "c", "", "config file (default is /etc/headscale/config.yaml)")

config-example.yaml

@@ -20,7 +20,7 @@ listen_addr: 127.0.0.1:8080
 
 # Address to listen to /metrics and /debug, you may want
 # to keep this endpoint private to your internal network
-# Use an emty value to disable the metrics listener.
+# Use an empty value to disable the metrics listener.
 metrics_listen_addr: 127.0.0.1:9090
 
 # Address to listen for gRPC.
@@ -128,7 +128,7 @@ derp:
   #
   # This option is mostly interesting for people hosting
   # their own DERP servers:
-  # https://tailscale.com/kb/1118/custom-derp-servers/
+  # https://tailscale.com/docs/reference/derp-servers/custom-derp-servers
   #
   # paths:
   #   - /etc/headscale/derp-example.yaml
@@ -165,6 +165,26 @@ node:
     # Time before an inactive ephemeral node is deleted.
     inactivity_timeout: 30m
 
+  # HA subnet router health probing.
+  #
+  # When HA routes exist (2+ nodes advertising the same prefix), headscale
+  # pings each HA node every probe_interval via the Noise channel. If a node
+  # fails to respond within probe_timeout it is marked unhealthy and the
+  # primary role moves to the next healthy node. A node that later responds
+  # is marked healthy again but does NOT reclaim primary (avoids flapping).
+  #
+  # Worst-case detection time is probe_interval + probe_timeout (15s default).
+  # No-op when no HA routes exist. Set probe_interval to 0 to disable.
+  routes:
+    ha:
+      # How often to ping HA subnet routers. Set to 0 to disable probing.
+      # Must be >= 2s when enabled.
+      probe_interval: 10s
+
+      # How long to wait for a ping response before marking a node unhealthy.
+      # Must be >= 1s and less than probe_interval.
+      probe_timeout: 5s
+
 database:
   # Database type. Available options: sqlite, postgres
   # Please note that using Postgres is highly discouraged as it is only supported for legacy reasons.
@@ -263,7 +283,7 @@ log:
 ## Policy
 # headscale supports Tailscale's ACL policies.
 # Please have a look to their KB to better
-# understand the concepts: https://tailscale.com/kb/1018/acls/
+# understand the concepts: https://tailscale.com/docs/features/access-control/acls
 policy:
   # The mode can be "file" or "database" that defines
   # where the ACL policies are stored and read from.
@@ -277,9 +297,9 @@ policy:
 # headscale supports Tailscale's DNS configuration and MagicDNS.
 # Please have a look to their KB to better understand the concepts:
 #
-# - https://tailscale.com/kb/1054/dns/
-# - https://tailscale.com/kb/1081/magicdns/
-# - https://tailscale.com/blog/2021-09-private-dns-with-magicdns/
+# - https://tailscale.com/docs/features/access-control/acls
+# - https://tailscale.com/docs/features/magicdns
+# - https://tailscale.com/blog/2021-09-private-dns-with-magicdns
 #
 # Please note that for the DNS configuration to have any effect,
 # clients must have the `--accept-dns=true` option enabled. This is the
@@ -289,12 +309,12 @@ policy:
 # Setting _any_ of the configuration and `--accept-dns=true` on the
 # clients will integrate with the DNS manager on the client or
 # overwrite /etc/resolv.conf.
-# https://tailscale.com/kb/1235/resolv-conf
+# https://tailscale.com/docs/reference/faq/dns-resolv-conf
 #
 # If you want stop Headscale from managing the DNS configuration
 # all the fields under `dns` should be set to empty values.
 dns:
-  # Whether to use [MagicDNS](https://tailscale.com/kb/1081/magicdns/).
+  # Whether to use [MagicDNS](https://tailscale.com/docs/features/magicdns).
   magic_dns: true
 
   # Defines the base domain to create the hostnames for MagicDNS.
@@ -316,11 +336,11 @@ dns:
       - 2606:4700:4700::1111
       - 2606:4700:4700::1001
 
-      # NextDNS (see https://tailscale.com/kb/1218/nextdns/).
+      # NextDNS (see https://tailscale.com/docs/integrations/nextdns).
       # "abc123" is example NextDNS ID, replace with yours.
       # - https://dns.nextdns.io/abc123
 
-    # Split DNS (see https://tailscale.com/kb/1054/dns/),
+    # Split DNS (see https://tailscale.com/docs/reference/dns-in-tailscale#restricted-nameservers),
     # a map of domains and which DNS server to use for each.
     split: {}
       # foo.bar.com:
@@ -425,7 +445,7 @@ unix_socket_permission: "0770"
 # Logtail is Tailscales logging and auditing infrastructure, it allows the
 # control panel to instruct tailscale nodes to log their activity to a remote
 # server. To disable logging on the client side, please refer to:
-# https://tailscale.com/kb/1011/log-mesh-traffic#opting-out-of-client-logging
+# https://tailscale.com/docs/features/logging#opt-out-of-client-logging
 logtail:
   # Enable logtail for tailscale nodes of this Headscale instance.
   # As there is currently no support for overriding the log server in Headscale, this is
@@ -434,12 +454,12 @@ logtail:
 
 # Enabling this option makes devices prefer a random port for WireGuard traffic over the
 # default static port 41641. This option is intended as a workaround for some buggy
-# firewall devices. See https://tailscale.com/kb/1181/firewalls/ for more information.
+# firewall devices. See https://tailscale.com/docs/integrations/firewalls for more information.
 randomize_client_port: false
 
 # Taildrop configuration
 # Taildrop is the file sharing feature of Tailscale, allowing nodes to send files to each other.
-# https://tailscale.com/kb/1106/taildrop/
+# https://tailscale.com/docs/features/taildrop
 taildrop:
   # Enable or disable Taildrop for all nodes.
   # When enabled, nodes can send files to other nodes owned by the same user.

derp-example.yaml

@@ -1,4 +1,5 @@
-# If you plan to somehow use headscale, please deploy your own DERP infra: https://tailscale.com/kb/1118/custom-derp-servers/
+# If you plan to somehow use headscale, please deploy your own DERP infra.
+# See: https://tailscale.com/docs/reference/derp-servers/custom-derp-servers
 regions:
   1: null # Disable DERP region with ID 1
   900:

docs/about/faq.md

@@ -145,7 +145,7 @@ This is essentially how Tailscale works. If traffic is allowed to flow in one di
 in their output of `tailscale status`. Traffic is still filtered according to the ACL, with the exception of
 `tailscale ping` which is always allowed in either direction.
 
-See also <https://tailscale.com/kb/1087/device-visibility>.
+See also <https://tailscale.com/docs/concepts/device-visibility>.
 
 ## My policy is stored in the database and Headscale refuses to start due to an invalid policy. How can I recover?
 
@@ -199,7 +199,7 @@ Nodes should reconnect within a few seconds and pickup their newly assigned IP a
 ## How can I avoid to send logs to Tailscale Inc?
 
 A Tailscale client [collects logs about its operation and connection attempts with other
-clients](https://tailscale.com/kb/1011/log-mesh-traffic#client-logs) and sends them to a central log service operated by
+clients](https://tailscale.com/docs/features/logging#client-logs) and sends them to a central log service operated by
 Tailscale Inc.
 
 Headscale, by default, instructs clients to disable log submission to the central log service. This configuration is
@@ -209,5 +209,5 @@ applied by a client once it successfully connected with Headscale. See the confi
 Alternatively, logging can also be disabled on the client side. This is independent of Headscale and opting out of
 client logging disables log submission early during client startup. The configuration is operating system specific and
 is usually achieved by setting the environment variable `TS_NO_LOGS_NO_SUPPORT=true` or by passing the flag
-`--no-logs-no-support` to `tailscaled`. See
-<https://tailscale.com/kb/1011/log-mesh-traffic#opting-out-of-client-logging> for details.
+`--no-logs-no-support` to `tailscaled`. See <https://tailscale.com/docs/features/logging#opt-out-of-client-logging> for
+details.

docs/about/features.md

@@ -9,11 +9,11 @@ provides on overview of Headscale's feature and compatibility with the Tailscale
     - [x] [Web authentication](../ref/registration.md#web-authentication)
     - [x] [Pre authenticated key](../ref/registration.md#pre-authenticated-key)
 - [x] [DNS](../ref/dns.md)
-    - [x] [MagicDNS](https://tailscale.com/kb/1081/magicdns)
-    - [x] [Global and restricted nameservers (split DNS)](https://tailscale.com/kb/1054/dns#nameservers)
-    - [x] [search domains](https://tailscale.com/kb/1054/dns#search-domains)
+    - [x] [MagicDNS](https://tailscale.com/docs/features/magicdns)
+    - [x] [Global and restricted nameservers (split DNS)](https://tailscale.com/docs/reference/dns-in-tailscale#nameservers)
+    - [x] [search domains](https://tailscale.com/docs/reference/dns-in-tailscale#search-domains)
     - [x] [Extra DNS records (Headscale only)](../ref/dns.md#setting-extra-dns-records)
-- [x] [Taildrop (File Sharing)](https://tailscale.com/kb/1106/taildrop)
+- [x] [Taildrop (File Sharing)](https://tailscale.com/docs/features/taildrop)
 - [x] [Tags](../ref/tags.md)
 - [x] [Routes](../ref/routes.md)
     - [x] [Subnet routers](../ref/routes.md#subnet-router)
@@ -23,16 +23,17 @@ provides on overview of Headscale's feature and compatibility with the Tailscale
 - [x] Embedded [DERP server](../ref/derp.md)
 - [x] Access control lists ([GitHub label "policy"](https://github.com/juanfont/headscale/labels/policy%20%F0%9F%93%9D))
     - [x] ACL management via API
-    - [x] Some [Autogroups](https://tailscale.com/kb/1396/targets#autogroups), currently: `autogroup:internet`,
-      `autogroup:nonroot`, `autogroup:member`, `autogroup:tagged`, `autogroup:self`
-    - [x] [Auto approvers](https://tailscale.com/kb/1337/acl-syntax#auto-approvers) for [subnet
+    - [x] Some [Autogroups](https://tailscale.com/docs/reference/targets-and-selectors#autogroups), currently:
+      `autogroup:internet`, `autogroup:nonroot`, `autogroup:member`, `autogroup:tagged`, `autogroup:self`,
+      `autogroup:danger-all`
+    - [x] [Auto approvers](https://tailscale.com/docs/reference/syntax/policy-file#auto-approvers) for [subnet
       routers](../ref/routes.md#automatically-approve-routes-of-a-subnet-router) and [exit
       nodes](../ref/routes.md#automatically-approve-an-exit-node-with-auto-approvers)
-    - [x] [Tailscale SSH](https://tailscale.com/kb/1193/tailscale-ssh)
+    - [x] [Tailscale SSH](https://tailscale.com/docs/features/tailscale-ssh)
 - [x] [Node registration using Single-Sign-On (OpenID Connect)](../ref/oidc.md) ([GitHub label "OIDC"](https://github.com/juanfont/headscale/labels/OIDC))
     - [x] Basic registration
     - [x] Update user profile from identity provider
     - [ ] OIDC groups cannot be used in ACLs
-- [ ] [Funnel](https://tailscale.com/kb/1223/funnel) ([#1040](https://github.com/juanfont/headscale/issues/1040))
-- [ ] [Serve](https://tailscale.com/kb/1312/serve) ([#1234](https://github.com/juanfont/headscale/issues/1921))
-- [ ] [Network flow logs](https://tailscale.com/kb/1219/network-flow-logs) ([#1687](https://github.com/juanfont/headscale/issues/1687))
+- [ ] [Funnel](https://tailscale.com/docs/features/tailscale-funnel) ([#1040](https://github.com/juanfont/headscale/issues/1040))
+- [ ] [Serve](https://tailscale.com/docs/features/tailscale-serve) ([#1234](https://github.com/juanfont/headscale/issues/1921))
+- [ ] [Network flow logs](https://tailscale.com/docs/features/logging/network-flow-logs) ([#1687](https://github.com/juanfont/headscale/issues/1687))

docs/ref/acls.md

@@ -3,7 +3,8 @@ Headscale implements the same policy ACLs as Tailscale.com, adapted to the self-
 For instance, instead of referring to users when defining groups you must
 use users (which are the equivalent to user/logins in Tailscale.com).
 
-Please check https://tailscale.com/kb/1018/acls/ for further information.
+Please check [manage permissions using ACLs](https://tailscale.com/docs/features/access-control/acls) for further
+information.
 
 When using ACL's the User borders are no longer applied. All machines
 whichever the User have the ability to communicate with other hosts as
@@ -15,8 +16,8 @@ To enable and configure ACLs in Headscale, you need to specify the path to your
 
 Your ACL policy file must be formatted using [huJSON](https://github.com/tailscale/hujson).
 
-Info on how these policies are written can be found
-[here](https://tailscale.com/kb/1018/acls/).
+Info on how these policies are written can be found in [Tailscale's ACL
+documentation](https://tailscale.com/docs/features/access-control/acls).
 
 Please reload or restart Headscale after updating the ACL file. Headscale may be reloaded either via its systemd service
 (`sudo systemctl reload headscale`) or by sending a SIGHUP signal (`sudo kill -HUP $(pidof headscale)`) to the main
@@ -24,13 +25,13 @@ process. Headscale logs the result of ACL policy processing after each reload.
 
 ## Simple Examples
 
-- [**Allow All**](https://tailscale.com/kb/1192/acl-samples#allow-all-default-acl): If you define an ACL file but completely omit the `"acls"` field from its content, Headscale will default to an "allow all" policy. This means all devices connected to your tailnet will be able to communicate freely with each other.
+- [**Allow All**](https://tailscale.com/docs/reference/examples/acls#allow-all-default-acl): If you define an ACL file but completely omit the `"acls"` field from its content, Headscale will default to an "allow all" policy. This means all devices connected to your tailnet will be able to communicate freely with each other.
 
     ```json
     {}
     ```
 
-- [**Deny All**](https://tailscale.com/kb/1192/acl-samples#deny-all): To prevent all communication within your tailnet, you can include an empty array for the `"acls"` field in your policy file.
+- [**Deny All**](https://tailscale.com/docs/reference/examples/acls#deny-all): To prevent all communication within your tailnet, you can include an empty array for the `"acls"` field in your policy file.
 
     ```json
     {
@@ -87,7 +88,7 @@ Here are the ACL's to implement the same permissions as above:
     "group:intern": ["intern1@"]
   },
   // tagOwners in tailscale is an association between a TAG and the people allowed to set this TAG on a server.
-  // This is documented [here](https://tailscale.com/kb/1068/acl-tags#defining-a-tag)
+  // This is documented [here](https://tailscale.com/docs/features/tags)
   // and explained [here](https://tailscale.com/blog/rbac-like-it-was-meant-to-be/)
   "tagOwners": {
     // the administrators can add servers in production
@@ -286,3 +287,9 @@ Used in Tailscale SSH rules to allow access to any user except root. Can only be
   "users": ["autogroup:nonroot"]
 }
 ```
+
+### `autogroup:danger-all`
+
+This autogroup resolves to all IP addresses (`0.0.0.0/0` and `::/0`) which also includes all IP addresses outside the
+standard Tailscale IP ranges. [This autogroup can only be used as
+source](https://tailscale.com/docs/reference/targets-and-selectors#autogroupdanger-all).

docs/ref/debug.md

@@ -3,16 +3,16 @@
 Headscale and Tailscale provide debug and introspection capabilities that can be helpful when things don't work as
 expected. This page explains some debugging techniques to help pinpoint problems.
 
-Please also have a look at [Tailscale's Troubleshooting guide](https://tailscale.com/kb/1023/troubleshooting). It offers
-a many tips and suggestions to troubleshoot common issues.
+Please also have a look at [Tailscale's Troubleshooting guide](https://tailscale.com/docs/reference/troubleshooting). It
+offers a many tips and suggestions to troubleshoot common issues.
 
 ## Tailscale
 
 The Tailscale client itself offers many commands to introspect its state as well as the state of the network:
 
-- [Check local network conditions](https://tailscale.com/kb/1080/cli#netcheck): `tailscale netcheck`
-- [Get the client status](https://tailscale.com/kb/1080/cli#status): `tailscale status --json`
-- [Get DNS status](https://tailscale.com/kb/1080/cli#dns): `tailscale dns status --all`
+- [Check local network conditions](https://tailscale.com/docs/reference/tailscale-cli#netcheck): `tailscale netcheck`
+- [Get the client status](https://tailscale.com/docs/reference/tailscale-cli#status): `tailscale status --json`
+- [Get DNS status](https://tailscale.com/docs/reference/tailscale-cli#dns): `tailscale dns status --all`
 - Client logs: `tailscale debug daemon-logs`
 - Client netmap: `tailscale debug netmap`
 - Test DERP connection: `tailscale debug derp headscale`

docs/ref/derp.md

@@ -1,8 +1,8 @@
 # DERP
 
-A [DERP (Designated Encrypted Relay for Packets) server](https://tailscale.com/kb/1232/derp-servers) is mainly used to
-relay traffic between two nodes in case a direct connection can't be established. Headscale provides an embedded DERP
-server to ensure seamless connectivity between nodes.
+A [DERP (Designated Encrypted Relay for Packets) server](https://tailscale.com/docs/reference/derp-servers) is mainly
+used to relay traffic between two nodes in case a direct connection can't be established. Headscale provides an embedded
+DERP server to ensure seamless connectivity between nodes.
 
 ## Configuration
 
@@ -31,8 +31,8 @@ traversal. [Check DERP server connectivity](#check-derp-server-connectivity) to
 ### Remove Tailscale's DERP servers
 
 Once enabled, Headscale's embedded DERP is added to the list of free-to-use [DERP
-servers](https://tailscale.com/kb/1232/derp-servers) offered by Tailscale Inc. To only use Headscale's embedded DERP
-server, disable the loading of the default DERP map:
+servers](https://tailscale.com/docs/reference/derp-servers) offered by Tailscale Inc. To only use Headscale's embedded
+DERP server, disable the loading of the default DERP map:
 
 ```yaml title="config.yaml" hl_lines="6"
 derp:
@@ -59,8 +59,8 @@ maps fetched via URL or to offer your own, custom DERP servers to nodes.
 
 === "Remove specific DERP regions"
 
-    The free-to-use [DERP servers](https://tailscale.com/kb/1232/derp-servers) are organized into regions via a region
-    ID. You can explicitly disable a specific region by setting its region ID to `null`. The following sample
+    The free-to-use [DERP servers](https://tailscale.com/docs/reference/derp-servers) are organized into regions via a
+    region ID. You can explicitly disable a specific region by setting its region ID to `null`. The following sample
     `derp.yaml` disables the New York DERP region (which has the region ID 1):
 
     ```yaml title="derp.yaml"

docs/ref/dns.md

@@ -6,8 +6,8 @@ within the `dns` section of the [configuration file](./configuration.md).
 ## Setting extra DNS records
 
 Headscale allows to set extra DNS records which are made available via
-[MagicDNS](https://tailscale.com/kb/1081/magicdns). Extra DNS records can be configured either via static entries in the
-[configuration file](./configuration.md) or from a JSON file that Headscale continuously watches for changes:
+[MagicDNS](https://tailscale.com/docs/features/magicdns). Extra DNS records can be configured either via static entries
+in the [configuration file](./configuration.md) or from a JSON file that Headscale continuously watches for changes:
 
 - Use the `dns.extra_records` option in the [configuration file](./configuration.md) for entries that are static and
   don't change while Headscale is running. Those entries are processed when Headscale is starting up and changes to the

docs/ref/integration/web-ui.md

@@ -22,5 +22,6 @@ Headscale doesn't provide a built-in web interface but users may pick one from t
 - [headscale-piying](https://github.com/wszgrcy/headscale-piying) - headscale web ui,support visual ACL configuration
 - [HeadControl](https://github.com/ahmadzip/HeadControl) - Minimal Headscale admin dashboard, built with Go and HTMX
 - [Headscale Manager](https://github.com/hkdone/headscalemanager) - Headscale UI for Android
+- [Headscale UI](https://github.com/MunMunMiao/headscale-ui) - Headscale UI online and Self-hosting
 
 You can ask for support on our [Discord server](https://discord.gg/c84AZQhmpx) in the "web-interfaces" channel.

docs/ref/registration.md

@@ -11,8 +11,8 @@ Tailscale's identity model distinguishes between personal and tagged nodes:
   workstations or mobile phones. End-user devices are managed by a single user.
 - A tagged node (or service-based node or non-human node) provides services to the network. Common examples include web-
   and database servers. Those nodes are typically managed by a team of users. Some additional restrictions apply for
-  tagged nodes, e.g. a tagged node is not allowed to [Tailscale SSH](https://tailscale.com/kb/1193/tailscale-ssh) into a
-  personal node.
+  tagged nodes, e.g. a tagged node is not allowed to [Tailscale SSH](https://tailscale.com/docs/features/tailscale-ssh)
+  into a personal node.
 
 Headscale implements Tailscale's identity model and distinguishes between personal and tagged nodes where a personal
 node is owned by a Headscale user and a tagged node is owned by a tag. Tagged devices are grouped under the special user
@@ -61,8 +61,8 @@ headscale users create <USER>
 === "Tagged devices"
 
     Your Headscale user needs to be authorized to register tagged devices. This authorization is specified in the
-    [`tagOwners`](https://tailscale.com/kb/1337/policy-syntax#tag-owners) section of the [ACL](acls.md). A simple
-    example looks like this:
+    [`tagOwners`](https://tailscale.com/docs/reference/syntax/policy-file#tag-owners) section of the [ACL](acls.md). A
+    simple example looks like this:
 
     ```json title="The user alice can register nodes tagged with tag:server"
     {

docs/ref/routes.md

@@ -1,7 +1,8 @@
 # Routes
 
-Headscale supports route advertising and can be used to manage [subnet routers](https://tailscale.com/kb/1019/subnets)
-and [exit nodes](https://tailscale.com/kb/1103/exit-nodes) for a tailnet.
+Headscale supports route advertising and can be used to manage [subnet
+routers](https://tailscale.com/docs/features/subnet-routers) and [exit
+nodes](https://tailscale.com/docs/features/exit-nodes) for a tailnet.
 
 - [Subnet routers](#subnet-router) may be used to connect an existing network such as a virtual
   private cloud or an on-premise network with your tailnet. Use a subnet router to access devices where Tailscale can't
@@ -72,8 +73,8 @@ $ sudo tailscale set --accept-routes
 ```
 
 Please refer to the official [Tailscale
-documentation](https://tailscale.com/kb/1019/subnets#use-your-subnet-routes-from-other-devices) for how to use a subnet
-router on different operating systems.
+documentation](https://tailscale.com/docs/features/subnet-routers#use-your-subnet-routes-from-other-devices) for how to
+use a subnet router on different operating systems.
 
 ### Restrict the use of a subnet router with ACL
 
@@ -135,8 +136,9 @@ Advertise the route `192.168.0.0/24` from a subnet router that also advertises t
 $ sudo tailscale up --login-server <YOUR_HEADSCALE_URL> --advertise-tags tag:router --advertise-routes 192.168.0.0/24
 ```
 
-Please see the [official Tailscale documentation](https://tailscale.com/kb/1337/acl-syntax#autoapprovers) for more
-information on auto approvers.
+Please see the [official Tailscale
+documentation](https://tailscale.com/docs/reference/syntax/policy-file#auto-approvers) for more information on auto
+approvers.
 
 ## Exit node
 
@@ -199,8 +201,8 @@ The exit node can now be used on a node with:
 $ sudo tailscale set --exit-node myexit
 ```
 
-Please refer to the official [Tailscale documentation](https://tailscale.com/kb/1103/exit-nodes#use-the-exit-node) for
-how to use an exit node on different operating systems.
+Please refer to the official [Tailscale documentation](https://tailscale.com/docs/features/exit-nodes#use-the-exit-node)
+for how to use an exit node on different operating systems.
 
 ### Restrict the use of an exit node with ACL
 
@@ -282,26 +284,23 @@ Advertise a node as exit node and also advertise the tag `tag:exit` when joining
 $ sudo tailscale up --login-server <YOUR_HEADSCALE_URL> --advertise-tags tag:exit --advertise-exit-node
 ```
 
-Please see the [official Tailscale documentation](https://tailscale.com/kb/1337/acl-syntax#autoapprovers) for more
-information on auto approvers.
+Please see the [official Tailscale documentation](https://tailscale.com/docs/reference/syntax/policy-file#autoapprovers)
+for more information on auto approvers.
 
 ## High availability
 
-Headscale has limited support for high availability routing. Multiple subnet routers with overlapping routes or multiple
-exit nodes can be used to provide high availability for users. If one router node goes offline, another one can serve
-the same routes to clients. Please see the official [Tailscale documentation on high
-availability](https://tailscale.com/kb/1115/high-availability#subnet-router-high-availability) for details.
+Headscale supports high availability routing. Multiple subnet routers with overlapping routes or multiple exit nodes can
+be used to provide high availability for users. If one router node goes offline, another one can serve the same routes
+to clients. Please see the official [Tailscale documentation on high
+availability](https://tailscale.com/docs/how-to/set-up-high-availability#subnet-router-high-availability) for details.
 
-!!! bug
-
-    In certain situations it might take up to 16 minutes for Headscale to detect a node as offline. A failover node
-    might not be selected fast enough, if such a node is used as subnet router or exit node causing service
-    interruptions for clients. See [issue 2129](https://github.com/juanfont/headscale/issues/2129) for more information.
+This feature is enabled by default when at least two nodes advertise the same prefix. See the configuration options
+`node.routes.ha` in the [configuration file](./configuration.md) for details.
 
 ## Troubleshooting
 
 ### Enable IP forwarding
 
 A subnet router or exit node is routing traffic on behalf of other nodes and thus requires IP forwarding. Check the
-official [Tailscale documentation](https://tailscale.com/kb/1019/subnets/?tab=linux#enable-ip-forwarding) for how to
+official [Tailscale documentation](https://tailscale.com/docs/features/subnet-routers#enable-ip-forwarding) for how to
 enable IP forwarding.

docs/ref/tags.md

@@ -1,7 +1,7 @@
 # Tags
 
-Headscale supports Tailscale tags. Please read [Tailscale's tag documentation](https://tailscale.com/kb/1068/tags) to
-learn how tags work and how to use them.
+Headscale supports Tailscale tags. Please read [Tailscale's tag documentation](https://tailscale.com/docs/features/tags)
+to learn how tags work and how to use them.
 
 Tags can be applied during [node registration](registration.md):
 

docs/setup/install/official.md

@@ -24,7 +24,8 @@ distributions are Ubuntu 22.04 or newer, Debian 12 or newer.
     sudo apt install ./headscale.deb
     ```
 
-1. [Configure headscale by editing the configuration file](../../ref/configuration.md):
+1. [Configure headscale by editing the configuration file](../../ref/configuration.md). An up-to date example
+   configuration file is also available in `/usr/share/doc/headscale/examples/config-example.yaml`:
 
     ```shell
     sudo nano /etc/headscale/config.yaml

docs/setup/requirements.md

@@ -17,7 +17,7 @@ The ports in use vary with the intended scenario and enabled features. Some of t
 - tcp/80
     - Expose publicly: yes
     - HTTP, used by Let's Encrypt to verify ownership via the HTTP-01 challenge.
-    - Only required if the built-in Let's Enrypt client with the HTTP-01 challenge is used. See [TLS](../ref/tls.md) for
+    - Only required if the built-in Let's Encrypt client with the HTTP-01 challenge is used. See [TLS](../ref/tls.md) for
       details.
 - tcp/443
     - Expose publicly: yes

docs/usage/connect/apple.md

@@ -25,7 +25,8 @@ Install the official Tailscale iOS client from the [App Store](https://apps.appl
 
 ### Installation
 
-Choose one of the available [Tailscale clients for macOS](https://tailscale.com/kb/1065/macos-variants) and install it.
+Choose one of the available [Tailscale clients for macOS](https://tailscale.com/docs/concepts/macos-variants) and
+install it.
 
 ### Configuring the headscale URL
 

docs/usage/connect/windows.md

@@ -33,7 +33,8 @@ all the time, please enable "Unattended mode":
 - Enable `Run unattended`
 - Confirm the "Unattended mode" message
 
-See also [Keep Tailscale running when I'm not logged in to my computer](https://tailscale.com/kb/1088/run-unattended)
+See also [Keep Tailscale running when I'm not logged in to my
+computer](https://tailscale.com/docs/how-to/run-unattended).
 
 ### Failing node registration
 

flake.nix

@@ -27,7 +27,7 @@
         let
           pkgs = nixpkgs.legacyPackages.${prev.stdenv.hostPlatform.system};
           buildGo = pkgs.buildGo126Module;
-          vendorHash = "sha256-x0xXxa7sjyDwWLq8fO0Z/pbPefctzctK3TAdBea7FtY=";
+          vendorHash = "sha256-8vTEkPEMbJ6DSOjcoQrYRyKSYI8jjcllTmJ6RXmUV9w=";
         in
         {
           headscale = buildGo {

gen/go/headscale/v1/headscale.pb.go

@@ -109,7 +109,7 @@ const file_headscale_v1_headscale_proto_rawDesc = "" +
 	"\x1cheadscale/v1/headscale.proto\x12\fheadscale.v1\x1a\x1cgoogle/api/annotations.proto\x1a\x17headscale/v1/user.proto\x1a\x1dheadscale/v1/preauthkey.proto\x1a\x17headscale/v1/node.proto\x1a\x19headscale/v1/apikey.proto\x1a\x17headscale/v1/auth.proto\x1a\x19headscale/v1/policy.proto\"\x0f\n" +
 	"\rHealthRequest\"E\n" +
 	"\x0eHealthResponse\x123\n" +
-	"\x15database_connectivity\x18\x01 \x01(\bR\x14databaseConnectivity2\xeb\x19\n" +
+	"\x15database_connectivity\x18\x01 \x01(\bR\x14databaseConnectivity2\xe0\x1a\n" +
 	"\x10HeadscaleService\x12h\n" +
 	"\n" +
 	"CreateUser\x12\x1f.headscale.v1.CreateUserRequest\x1a .headscale.v1.CreateUserResponse\"\x17\x82\xd3\xe4\x93\x02\x11:\x01*\"\f/api/v1/user\x12\x80\x01\n" +
@@ -144,7 +144,8 @@ const file_headscale_v1_headscale_proto_rawDesc = "" +
 	"\vListApiKeys\x12 .headscale.v1.ListApiKeysRequest\x1a!.headscale.v1.ListApiKeysResponse\"\x16\x82\xd3\xe4\x93\x02\x10\x12\x0e/api/v1/apikey\x12v\n" +
 	"\fDeleteApiKey\x12!.headscale.v1.DeleteApiKeyRequest\x1a\".headscale.v1.DeleteApiKeyResponse\"\x1f\x82\xd3\xe4\x93\x02\x19*\x17/api/v1/apikey/{prefix}\x12d\n" +
 	"\tGetPolicy\x12\x1e.headscale.v1.GetPolicyRequest\x1a\x1f.headscale.v1.GetPolicyResponse\"\x16\x82\xd3\xe4\x93\x02\x10\x12\x0e/api/v1/policy\x12g\n" +
-	"\tSetPolicy\x12\x1e.headscale.v1.SetPolicyRequest\x1a\x1f.headscale.v1.SetPolicyResponse\"\x19\x82\xd3\xe4\x93\x02\x13:\x01*\x1a\x0e/api/v1/policy\x12[\n" +
+	"\tSetPolicy\x12\x1e.headscale.v1.SetPolicyRequest\x1a\x1f.headscale.v1.SetPolicyResponse\"\x19\x82\xd3\xe4\x93\x02\x13:\x01*\x1a\x0e/api/v1/policy\x12s\n" +
+	"\vCheckPolicy\x12 .headscale.v1.CheckPolicyRequest\x1a!.headscale.v1.CheckPolicyResponse\"\x1f\x82\xd3\xe4\x93\x02\x19:\x01*\"\x14/api/v1/policy/check\x12[\n" +
 	"\x06Health\x12\x1b.headscale.v1.HealthRequest\x1a\x1c.headscale.v1.HealthResponse\"\x16\x82\xd3\xe4\x93\x02\x10\x12\x0e/api/v1/healthB)Z'github.com/juanfont/headscale/gen/go/v1b\x06proto3"
 
 var (
@@ -190,33 +191,35 @@ var file_headscale_v1_headscale_proto_goTypes = []any{
 	(*DeleteApiKeyRequest)(nil),       // 26: headscale.v1.DeleteApiKeyRequest
 	(*GetPolicyRequest)(nil),          // 27: headscale.v1.GetPolicyRequest
 	(*SetPolicyRequest)(nil),          // 28: headscale.v1.SetPolicyRequest
-	(*CreateUserResponse)(nil),        // 29: headscale.v1.CreateUserResponse
-	(*RenameUserResponse)(nil),        // 30: headscale.v1.RenameUserResponse
-	(*DeleteUserResponse)(nil),        // 31: headscale.v1.DeleteUserResponse
-	(*ListUsersResponse)(nil),         // 32: headscale.v1.ListUsersResponse
-	(*CreatePreAuthKeyResponse)(nil),  // 33: headscale.v1.CreatePreAuthKeyResponse
-	(*ExpirePreAuthKeyResponse)(nil),  // 34: headscale.v1.ExpirePreAuthKeyResponse
-	(*DeletePreAuthKeyResponse)(nil),  // 35: headscale.v1.DeletePreAuthKeyResponse
-	(*ListPreAuthKeysResponse)(nil),   // 36: headscale.v1.ListPreAuthKeysResponse
-	(*DebugCreateNodeResponse)(nil),   // 37: headscale.v1.DebugCreateNodeResponse
-	(*GetNodeResponse)(nil),           // 38: headscale.v1.GetNodeResponse
-	(*SetTagsResponse)(nil),           // 39: headscale.v1.SetTagsResponse
-	(*SetApprovedRoutesResponse)(nil), // 40: headscale.v1.SetApprovedRoutesResponse
-	(*RegisterNodeResponse)(nil),      // 41: headscale.v1.RegisterNodeResponse
-	(*DeleteNodeResponse)(nil),        // 42: headscale.v1.DeleteNodeResponse
-	(*ExpireNodeResponse)(nil),        // 43: headscale.v1.ExpireNodeResponse
-	(*RenameNodeResponse)(nil),        // 44: headscale.v1.RenameNodeResponse
-	(*ListNodesResponse)(nil),         // 45: headscale.v1.ListNodesResponse
-	(*BackfillNodeIPsResponse)(nil),   // 46: headscale.v1.BackfillNodeIPsResponse
-	(*AuthRegisterResponse)(nil),      // 47: headscale.v1.AuthRegisterResponse
-	(*AuthApproveResponse)(nil),       // 48: headscale.v1.AuthApproveResponse
-	(*AuthRejectResponse)(nil),        // 49: headscale.v1.AuthRejectResponse
-	(*CreateApiKeyResponse)(nil),      // 50: headscale.v1.CreateApiKeyResponse
-	(*ExpireApiKeyResponse)(nil),      // 51: headscale.v1.ExpireApiKeyResponse
-	(*ListApiKeysResponse)(nil),       // 52: headscale.v1.ListApiKeysResponse
-	(*DeleteApiKeyResponse)(nil),      // 53: headscale.v1.DeleteApiKeyResponse
-	(*GetPolicyResponse)(nil),         // 54: headscale.v1.GetPolicyResponse
-	(*SetPolicyResponse)(nil),         // 55: headscale.v1.SetPolicyResponse
+	(*CheckPolicyRequest)(nil),        // 29: headscale.v1.CheckPolicyRequest
+	(*CreateUserResponse)(nil),        // 30: headscale.v1.CreateUserResponse
+	(*RenameUserResponse)(nil),        // 31: headscale.v1.RenameUserResponse
+	(*DeleteUserResponse)(nil),        // 32: headscale.v1.DeleteUserResponse
+	(*ListUsersResponse)(nil),         // 33: headscale.v1.ListUsersResponse
+	(*CreatePreAuthKeyResponse)(nil),  // 34: headscale.v1.CreatePreAuthKeyResponse
+	(*ExpirePreAuthKeyResponse)(nil),  // 35: headscale.v1.ExpirePreAuthKeyResponse
+	(*DeletePreAuthKeyResponse)(nil),  // 36: headscale.v1.DeletePreAuthKeyResponse
+	(*ListPreAuthKeysResponse)(nil),   // 37: headscale.v1.ListPreAuthKeysResponse
+	(*DebugCreateNodeResponse)(nil),   // 38: headscale.v1.DebugCreateNodeResponse
+	(*GetNodeResponse)(nil),           // 39: headscale.v1.GetNodeResponse
+	(*SetTagsResponse)(nil),           // 40: headscale.v1.SetTagsResponse
+	(*SetApprovedRoutesResponse)(nil), // 41: headscale.v1.SetApprovedRoutesResponse
+	(*RegisterNodeResponse)(nil),      // 42: headscale.v1.RegisterNodeResponse
+	(*DeleteNodeResponse)(nil),        // 43: headscale.v1.DeleteNodeResponse
+	(*ExpireNodeResponse)(nil),        // 44: headscale.v1.ExpireNodeResponse
+	(*RenameNodeResponse)(nil),        // 45: headscale.v1.RenameNodeResponse
+	(*ListNodesResponse)(nil),         // 46: headscale.v1.ListNodesResponse
+	(*BackfillNodeIPsResponse)(nil),   // 47: headscale.v1.BackfillNodeIPsResponse
+	(*AuthRegisterResponse)(nil),      // 48: headscale.v1.AuthRegisterResponse
+	(*AuthApproveResponse)(nil),       // 49: headscale.v1.AuthApproveResponse
+	(*AuthRejectResponse)(nil),        // 50: headscale.v1.AuthRejectResponse
+	(*CreateApiKeyResponse)(nil),      // 51: headscale.v1.CreateApiKeyResponse
+	(*ExpireApiKeyResponse)(nil),      // 52: headscale.v1.ExpireApiKeyResponse
+	(*ListApiKeysResponse)(nil),       // 53: headscale.v1.ListApiKeysResponse
+	(*DeleteApiKeyResponse)(nil),      // 54: headscale.v1.DeleteApiKeyResponse
+	(*GetPolicyResponse)(nil),         // 55: headscale.v1.GetPolicyResponse
+	(*SetPolicyResponse)(nil),         // 56: headscale.v1.SetPolicyResponse
+	(*CheckPolicyResponse)(nil),       // 57: headscale.v1.CheckPolicyResponse
 }
 var file_headscale_v1_headscale_proto_depIdxs = []int32{
 	2,  // 0: headscale.v1.HeadscaleService.CreateUser:input_type -> headscale.v1.CreateUserRequest
@@ -246,37 +249,39 @@ var file_headscale_v1_headscale_proto_depIdxs = []int32{
 	26, // 24: headscale.v1.HeadscaleService.DeleteApiKey:input_type -> headscale.v1.DeleteApiKeyRequest
 	27, // 25: headscale.v1.HeadscaleService.GetPolicy:input_type -> headscale.v1.GetPolicyRequest
 	28, // 26: headscale.v1.HeadscaleService.SetPolicy:input_type -> headscale.v1.SetPolicyRequest
-	0,  // 27: headscale.v1.HeadscaleService.Health:input_type -> headscale.v1.HealthRequest
-	29, // 28: headscale.v1.HeadscaleService.CreateUser:output_type -> headscale.v1.CreateUserResponse
-	30, // 29: headscale.v1.HeadscaleService.RenameUser:output_type -> headscale.v1.RenameUserResponse
-	31, // 30: headscale.v1.HeadscaleService.DeleteUser:output_type -> headscale.v1.DeleteUserResponse
-	32, // 31: headscale.v1.HeadscaleService.ListUsers:output_type -> headscale.v1.ListUsersResponse
-	33, // 32: headscale.v1.HeadscaleService.CreatePreAuthKey:output_type -> headscale.v1.CreatePreAuthKeyResponse
-	34, // 33: headscale.v1.HeadscaleService.ExpirePreAuthKey:output_type -> headscale.v1.ExpirePreAuthKeyResponse
-	35, // 34: headscale.v1.HeadscaleService.DeletePreAuthKey:output_type -> headscale.v1.DeletePreAuthKeyResponse
-	36, // 35: headscale.v1.HeadscaleService.ListPreAuthKeys:output_type -> headscale.v1.ListPreAuthKeysResponse
-	37, // 36: headscale.v1.HeadscaleService.DebugCreateNode:output_type -> headscale.v1.DebugCreateNodeResponse
-	38, // 37: headscale.v1.HeadscaleService.GetNode:output_type -> headscale.v1.GetNodeResponse
-	39, // 38: headscale.v1.HeadscaleService.SetTags:output_type -> headscale.v1.SetTagsResponse
-	40, // 39: headscale.v1.HeadscaleService.SetApprovedRoutes:output_type -> headscale.v1.SetApprovedRoutesResponse
-	41, // 40: headscale.v1.HeadscaleService.RegisterNode:output_type -> headscale.v1.RegisterNodeResponse
-	42, // 41: headscale.v1.HeadscaleService.DeleteNode:output_type -> headscale.v1.DeleteNodeResponse
-	43, // 42: headscale.v1.HeadscaleService.ExpireNode:output_type -> headscale.v1.ExpireNodeResponse
-	44, // 43: headscale.v1.HeadscaleService.RenameNode:output_type -> headscale.v1.RenameNodeResponse
-	45, // 44: headscale.v1.HeadscaleService.ListNodes:output_type -> headscale.v1.ListNodesResponse
-	46, // 45: headscale.v1.HeadscaleService.BackfillNodeIPs:output_type -> headscale.v1.BackfillNodeIPsResponse
-	47, // 46: headscale.v1.HeadscaleService.AuthRegister:output_type -> headscale.v1.AuthRegisterResponse
-	48, // 47: headscale.v1.HeadscaleService.AuthApprove:output_type -> headscale.v1.AuthApproveResponse
-	49, // 48: headscale.v1.HeadscaleService.AuthReject:output_type -> headscale.v1.AuthRejectResponse
-	50, // 49: headscale.v1.HeadscaleService.CreateApiKey:output_type -> headscale.v1.CreateApiKeyResponse
-	51, // 50: headscale.v1.HeadscaleService.ExpireApiKey:output_type -> headscale.v1.ExpireApiKeyResponse
-	52, // 51: headscale.v1.HeadscaleService.ListApiKeys:output_type -> headscale.v1.ListApiKeysResponse
-	53, // 52: headscale.v1.HeadscaleService.DeleteApiKey:output_type -> headscale.v1.DeleteApiKeyResponse
-	54, // 53: headscale.v1.HeadscaleService.GetPolicy:output_type -> headscale.v1.GetPolicyResponse
-	55, // 54: headscale.v1.HeadscaleService.SetPolicy:output_type -> headscale.v1.SetPolicyResponse
-	1,  // 55: headscale.v1.HeadscaleService.Health:output_type -> headscale.v1.HealthResponse
-	28, // [28:56] is the sub-list for method output_type
-	0,  // [0:28] is the sub-list for method input_type
+	29, // 27: headscale.v1.HeadscaleService.CheckPolicy:input_type -> headscale.v1.CheckPolicyRequest
+	0,  // 28: headscale.v1.HeadscaleService.Health:input_type -> headscale.v1.HealthRequest
+	30, // 29: headscale.v1.HeadscaleService.CreateUser:output_type -> headscale.v1.CreateUserResponse
+	31, // 30: headscale.v1.HeadscaleService.RenameUser:output_type -> headscale.v1.RenameUserResponse
+	32, // 31: headscale.v1.HeadscaleService.DeleteUser:output_type -> headscale.v1.DeleteUserResponse
+	33, // 32: headscale.v1.HeadscaleService.ListUsers:output_type -> headscale.v1.ListUsersResponse
+	34, // 33: headscale.v1.HeadscaleService.CreatePreAuthKey:output_type -> headscale.v1.CreatePreAuthKeyResponse
+	35, // 34: headscale.v1.HeadscaleService.ExpirePreAuthKey:output_type -> headscale.v1.ExpirePreAuthKeyResponse
+	36, // 35: headscale.v1.HeadscaleService.DeletePreAuthKey:output_type -> headscale.v1.DeletePreAuthKeyResponse
+	37, // 36: headscale.v1.HeadscaleService.ListPreAuthKeys:output_type -> headscale.v1.ListPreAuthKeysResponse
+	38, // 37: headscale.v1.HeadscaleService.DebugCreateNode:output_type -> headscale.v1.DebugCreateNodeResponse
+	39, // 38: headscale.v1.HeadscaleService.GetNode:output_type -> headscale.v1.GetNodeResponse
+	40, // 39: headscale.v1.HeadscaleService.SetTags:output_type -> headscale.v1.SetTagsResponse
+	41, // 40: headscale.v1.HeadscaleService.SetApprovedRoutes:output_type -> headscale.v1.SetApprovedRoutesResponse
+	42, // 41: headscale.v1.HeadscaleService.RegisterNode:output_type -> headscale.v1.RegisterNodeResponse
+	43, // 42: headscale.v1.HeadscaleService.DeleteNode:output_type -> headscale.v1.DeleteNodeResponse
+	44, // 43: headscale.v1.HeadscaleService.ExpireNode:output_type -> headscale.v1.ExpireNodeResponse
+	45, // 44: headscale.v1.HeadscaleService.RenameNode:output_type -> headscale.v1.RenameNodeResponse
+	46, // 45: headscale.v1.HeadscaleService.ListNodes:output_type -> headscale.v1.ListNodesResponse
+	47, // 46: headscale.v1.HeadscaleService.BackfillNodeIPs:output_type -> headscale.v1.BackfillNodeIPsResponse
+	48, // 47: headscale.v1.HeadscaleService.AuthRegister:output_type -> headscale.v1.AuthRegisterResponse
+	49, // 48: headscale.v1.HeadscaleService.AuthApprove:output_type -> headscale.v1.AuthApproveResponse
+	50, // 49: headscale.v1.HeadscaleService.AuthReject:output_type -> headscale.v1.AuthRejectResponse
+	51, // 50: headscale.v1.HeadscaleService.CreateApiKey:output_type -> headscale.v1.CreateApiKeyResponse
+	52, // 51: headscale.v1.HeadscaleService.ExpireApiKey:output_type -> headscale.v1.ExpireApiKeyResponse
+	53, // 52: headscale.v1.HeadscaleService.ListApiKeys:output_type -> headscale.v1.ListApiKeysResponse
+	54, // 53: headscale.v1.HeadscaleService.DeleteApiKey:output_type -> headscale.v1.DeleteApiKeyResponse
+	55, // 54: headscale.v1.HeadscaleService.GetPolicy:output_type -> headscale.v1.GetPolicyResponse
+	56, // 55: headscale.v1.HeadscaleService.SetPolicy:output_type -> headscale.v1.SetPolicyResponse
+	57, // 56: headscale.v1.HeadscaleService.CheckPolicy:output_type -> headscale.v1.CheckPolicyResponse
+	1,  // 57: headscale.v1.HeadscaleService.Health:output_type -> headscale.v1.HealthResponse
+	29, // [29:58] is the sub-list for method output_type
+	0,  // [0:29] is the sub-list for method input_type
 	0,  // [0:0] is the sub-list for extension type_name
 	0,  // [0:0] is the sub-list for extension extendee
 	0,  // [0:0] is the sub-list for field type_name

gen/go/headscale/v1/headscale.pb.gw.go

@@ -966,6 +966,33 @@ func local_request_HeadscaleService_SetPolicy_0(ctx context.Context, marshaler r
 	return msg, metadata, err
 }
 
+func request_HeadscaleService_CheckPolicy_0(ctx context.Context, marshaler runtime.Marshaler, client HeadscaleServiceClient, req *http.Request, pathParams map[string]string) (proto.Message, runtime.ServerMetadata, error) {
+	var (
+		protoReq CheckPolicyRequest
+		metadata runtime.ServerMetadata
+	)
+	if err := marshaler.NewDecoder(req.Body).Decode(&protoReq); err != nil && !errors.Is(err, io.EOF) {
+		return nil, metadata, status.Errorf(codes.InvalidArgument, "%v", err)
+	}
+	if req.Body != nil {
+		_, _ = io.Copy(io.Discard, req.Body)
+	}
+	msg, err := client.CheckPolicy(ctx, &protoReq, grpc.Header(&metadata.HeaderMD), grpc.Trailer(&metadata.TrailerMD))
+	return msg, metadata, err
+}
+
+func local_request_HeadscaleService_CheckPolicy_0(ctx context.Context, marshaler runtime.Marshaler, server HeadscaleServiceServer, req *http.Request, pathParams map[string]string) (proto.Message, runtime.ServerMetadata, error) {
+	var (
+		protoReq CheckPolicyRequest
+		metadata runtime.ServerMetadata
+	)
+	if err := marshaler.NewDecoder(req.Body).Decode(&protoReq); err != nil && !errors.Is(err, io.EOF) {
+		return nil, metadata, status.Errorf(codes.InvalidArgument, "%v", err)
+	}
+	msg, err := server.CheckPolicy(ctx, &protoReq)
+	return msg, metadata, err
+}
+
 func request_HeadscaleService_Health_0(ctx context.Context, marshaler runtime.Marshaler, client HeadscaleServiceClient, req *http.Request, pathParams map[string]string) (proto.Message, runtime.ServerMetadata, error) {
 	var (
 		protoReq HealthRequest
@@ -1533,6 +1560,26 @@ func RegisterHeadscaleServiceHandlerServer(ctx context.Context, mux *runtime.Ser
 		}
 		forward_HeadscaleService_SetPolicy_0(annotatedContext, mux, outboundMarshaler, w, req, resp, mux.GetForwardResponseOptions()...)
 	})
+	mux.Handle(http.MethodPost, pattern_HeadscaleService_CheckPolicy_0, func(w http.ResponseWriter, req *http.Request, pathParams map[string]string) {
+		ctx, cancel := context.WithCancel(req.Context())
+		defer cancel()
+		var stream runtime.ServerTransportStream
+		ctx = grpc.NewContextWithServerTransportStream(ctx, &stream)
+		inboundMarshaler, outboundMarshaler := runtime.MarshalerForRequest(mux, req)
+		annotatedContext, err := runtime.AnnotateIncomingContext(ctx, mux, req, "/headscale.v1.HeadscaleService/CheckPolicy", runtime.WithHTTPPathPattern("/api/v1/policy/check"))
+		if err != nil {
+			runtime.HTTPError(ctx, mux, outboundMarshaler, w, req, err)
+			return
+		}
+		resp, md, err := local_request_HeadscaleService_CheckPolicy_0(annotatedContext, inboundMarshaler, server, req, pathParams)
+		md.HeaderMD, md.TrailerMD = metadata.Join(md.HeaderMD, stream.Header()), metadata.Join(md.TrailerMD, stream.Trailer())
+		annotatedContext = runtime.NewServerMetadataContext(annotatedContext, md)
+		if err != nil {
+			runtime.HTTPError(annotatedContext, mux, outboundMarshaler, w, req, err)
+			return
+		}
+		forward_HeadscaleService_CheckPolicy_0(annotatedContext, mux, outboundMarshaler, w, req, resp, mux.GetForwardResponseOptions()...)
+	})
 	mux.Handle(http.MethodGet, pattern_HeadscaleService_Health_0, func(w http.ResponseWriter, req *http.Request, pathParams map[string]string) {
 		ctx, cancel := context.WithCancel(req.Context())
 		defer cancel()
@@ -2052,6 +2099,23 @@ func RegisterHeadscaleServiceHandlerClient(ctx context.Context, mux *runtime.Ser
 		}
 		forward_HeadscaleService_SetPolicy_0(annotatedContext, mux, outboundMarshaler, w, req, resp, mux.GetForwardResponseOptions()...)
 	})
+	mux.Handle(http.MethodPost, pattern_HeadscaleService_CheckPolicy_0, func(w http.ResponseWriter, req *http.Request, pathParams map[string]string) {
+		ctx, cancel := context.WithCancel(req.Context())
+		defer cancel()
+		inboundMarshaler, outboundMarshaler := runtime.MarshalerForRequest(mux, req)
+		annotatedContext, err := runtime.AnnotateContext(ctx, mux, req, "/headscale.v1.HeadscaleService/CheckPolicy", runtime.WithHTTPPathPattern("/api/v1/policy/check"))
+		if err != nil {
+			runtime.HTTPError(ctx, mux, outboundMarshaler, w, req, err)
+			return
+		}
+		resp, md, err := request_HeadscaleService_CheckPolicy_0(annotatedContext, inboundMarshaler, client, req, pathParams)
+		annotatedContext = runtime.NewServerMetadataContext(annotatedContext, md)
+		if err != nil {
+			runtime.HTTPError(annotatedContext, mux, outboundMarshaler, w, req, err)
+			return
+		}
+		forward_HeadscaleService_CheckPolicy_0(annotatedContext, mux, outboundMarshaler, w, req, resp, mux.GetForwardResponseOptions()...)
+	})
 	mux.Handle(http.MethodGet, pattern_HeadscaleService_Health_0, func(w http.ResponseWriter, req *http.Request, pathParams map[string]string) {
 		ctx, cancel := context.WithCancel(req.Context())
 		defer cancel()
@@ -2100,6 +2164,7 @@ var (
 	pattern_HeadscaleService_DeleteApiKey_0      = runtime.MustPattern(runtime.NewPattern(1, []int{2, 0, 2, 1, 2, 2, 1, 0, 4, 1, 5, 3}, []string{"api", "v1", "apikey", "prefix"}, ""))
 	pattern_HeadscaleService_GetPolicy_0         = runtime.MustPattern(runtime.NewPattern(1, []int{2, 0, 2, 1, 2, 2}, []string{"api", "v1", "policy"}, ""))
 	pattern_HeadscaleService_SetPolicy_0         = runtime.MustPattern(runtime.NewPattern(1, []int{2, 0, 2, 1, 2, 2}, []string{"api", "v1", "policy"}, ""))
+	pattern_HeadscaleService_CheckPolicy_0       = runtime.MustPattern(runtime.NewPattern(1, []int{2, 0, 2, 1, 2, 2, 2, 3}, []string{"api", "v1", "policy", "check"}, ""))
 	pattern_HeadscaleService_Health_0            = runtime.MustPattern(runtime.NewPattern(1, []int{2, 0, 2, 1, 2, 2}, []string{"api", "v1", "health"}, ""))
 )
 
@@ -2131,5 +2196,6 @@ var (
 	forward_HeadscaleService_DeleteApiKey_0      = runtime.ForwardResponseMessage
 	forward_HeadscaleService_GetPolicy_0         = runtime.ForwardResponseMessage
 	forward_HeadscaleService_SetPolicy_0         = runtime.ForwardResponseMessage
+	forward_HeadscaleService_CheckPolicy_0       = runtime.ForwardResponseMessage
 	forward_HeadscaleService_Health_0            = runtime.ForwardResponseMessage
 )

gen/go/headscale/v1/headscale_grpc.pb.go

@@ -46,6 +46,7 @@ const (
 	HeadscaleService_DeleteApiKey_FullMethodName      = "/headscale.v1.HeadscaleService/DeleteApiKey"
 	HeadscaleService_GetPolicy_FullMethodName         = "/headscale.v1.HeadscaleService/GetPolicy"
 	HeadscaleService_SetPolicy_FullMethodName         = "/headscale.v1.HeadscaleService/SetPolicy"
+	HeadscaleService_CheckPolicy_FullMethodName       = "/headscale.v1.HeadscaleService/CheckPolicy"
 	HeadscaleService_Health_FullMethodName            = "/headscale.v1.HeadscaleService/Health"
 )
 
@@ -86,6 +87,7 @@ type HeadscaleServiceClient interface {
 	// --- Policy start ---
 	GetPolicy(ctx context.Context, in *GetPolicyRequest, opts ...grpc.CallOption) (*GetPolicyResponse, error)
 	SetPolicy(ctx context.Context, in *SetPolicyRequest, opts ...grpc.CallOption) (*SetPolicyResponse, error)
+	CheckPolicy(ctx context.Context, in *CheckPolicyRequest, opts ...grpc.CallOption) (*CheckPolicyResponse, error)
 	// --- Health start ---
 	Health(ctx context.Context, in *HealthRequest, opts ...grpc.CallOption) (*HealthResponse, error)
 }
@@ -368,6 +370,16 @@ func (c *headscaleServiceClient) SetPolicy(ctx context.Context, in *SetPolicyReq
 	return out, nil
 }
 
+func (c *headscaleServiceClient) CheckPolicy(ctx context.Context, in *CheckPolicyRequest, opts ...grpc.CallOption) (*CheckPolicyResponse, error) {
+	cOpts := append([]grpc.CallOption{grpc.StaticMethod()}, opts...)
+	out := new(CheckPolicyResponse)
+	err := c.cc.Invoke(ctx, HeadscaleService_CheckPolicy_FullMethodName, in, out, cOpts...)
+	if err != nil {
+		return nil, err
+	}
+	return out, nil
+}
+
 func (c *headscaleServiceClient) Health(ctx context.Context, in *HealthRequest, opts ...grpc.CallOption) (*HealthResponse, error) {
 	cOpts := append([]grpc.CallOption{grpc.StaticMethod()}, opts...)
 	out := new(HealthResponse)
@@ -415,6 +427,7 @@ type HeadscaleServiceServer interface {
 	// --- Policy start ---
 	GetPolicy(context.Context, *GetPolicyRequest) (*GetPolicyResponse, error)
 	SetPolicy(context.Context, *SetPolicyRequest) (*SetPolicyResponse, error)
+	CheckPolicy(context.Context, *CheckPolicyRequest) (*CheckPolicyResponse, error)
 	// --- Health start ---
 	Health(context.Context, *HealthRequest) (*HealthResponse, error)
 	mustEmbedUnimplementedHeadscaleServiceServer()
@@ -508,6 +521,9 @@ func (UnimplementedHeadscaleServiceServer) GetPolicy(context.Context, *GetPolicy
 func (UnimplementedHeadscaleServiceServer) SetPolicy(context.Context, *SetPolicyRequest) (*SetPolicyResponse, error) {
 	return nil, status.Error(codes.Unimplemented, "method SetPolicy not implemented")
 }
+func (UnimplementedHeadscaleServiceServer) CheckPolicy(context.Context, *CheckPolicyRequest) (*CheckPolicyResponse, error) {
+	return nil, status.Error(codes.Unimplemented, "method CheckPolicy not implemented")
+}
 func (UnimplementedHeadscaleServiceServer) Health(context.Context, *HealthRequest) (*HealthResponse, error) {
 	return nil, status.Error(codes.Unimplemented, "method Health not implemented")
 }
@@ -1018,6 +1034,24 @@ func _HeadscaleService_SetPolicy_Handler(srv interface{}, ctx context.Context, d
 	return interceptor(ctx, in, info, handler)
 }
 
+func _HeadscaleService_CheckPolicy_Handler(srv interface{}, ctx context.Context, dec func(interface{}) error, interceptor grpc.UnaryServerInterceptor) (interface{}, error) {
+	in := new(CheckPolicyRequest)
+	if err := dec(in); err != nil {
+		return nil, err
+	}
+	if interceptor == nil {
+		return srv.(HeadscaleServiceServer).CheckPolicy(ctx, in)
+	}
+	info := &grpc.UnaryServerInfo{
+		Server:     srv,
+		FullMethod: HeadscaleService_CheckPolicy_FullMethodName,
+	}
+	handler := func(ctx context.Context, req interface{}) (interface{}, error) {
+		return srv.(HeadscaleServiceServer).CheckPolicy(ctx, req.(*CheckPolicyRequest))
+	}
+	return interceptor(ctx, in, info, handler)
+}
+
 func _HeadscaleService_Health_Handler(srv interface{}, ctx context.Context, dec func(interface{}) error, interceptor grpc.UnaryServerInterceptor) (interface{}, error) {
 	in := new(HealthRequest)
 	if err := dec(in); err != nil {
@@ -1151,6 +1185,10 @@ var HeadscaleService_ServiceDesc = grpc.ServiceDesc{
 			MethodName: "SetPolicy",
 			Handler:    _HeadscaleService_SetPolicy_Handler,
 		},
+		{
+			MethodName: "CheckPolicy",
+			Handler:    _HeadscaleService_CheckPolicy_Handler,
+		},
 		{
 			MethodName: "Health",
 			Handler:    _HeadscaleService_Health_Handler,

gen/go/headscale/v1/policy.pb.go

@@ -206,6 +206,86 @@ func (x *GetPolicyResponse) GetUpdatedAt() *timestamppb.Timestamp {
 	return nil
 }
 
+type CheckPolicyRequest struct {
+	state         protoimpl.MessageState `protogen:"open.v1"`
+	Policy        string                 `protobuf:"bytes,1,opt,name=policy,proto3" json:"policy,omitempty"`
+	unknownFields protoimpl.UnknownFields
+	sizeCache     protoimpl.SizeCache
+}
+
+func (x *CheckPolicyRequest) Reset() {
+	*x = CheckPolicyRequest{}
+	mi := &file_headscale_v1_policy_proto_msgTypes[4]
+	ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
+	ms.StoreMessageInfo(mi)
+}
+
+func (x *CheckPolicyRequest) String() string {
+	return protoimpl.X.MessageStringOf(x)
+}
+
+func (*CheckPolicyRequest) ProtoMessage() {}
+
+func (x *CheckPolicyRequest) ProtoReflect() protoreflect.Message {
+	mi := &file_headscale_v1_policy_proto_msgTypes[4]
+	if x != nil {
+		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
+		if ms.LoadMessageInfo() == nil {
+			ms.StoreMessageInfo(mi)
+		}
+		return ms
+	}
+	return mi.MessageOf(x)
+}
+
+// Deprecated: Use CheckPolicyRequest.ProtoReflect.Descriptor instead.
+func (*CheckPolicyRequest) Descriptor() ([]byte, []int) {
+	return file_headscale_v1_policy_proto_rawDescGZIP(), []int{4}
+}
+
+func (x *CheckPolicyRequest) GetPolicy() string {
+	if x != nil {
+		return x.Policy
+	}
+	return ""
+}
+
+type CheckPolicyResponse struct {
+	state         protoimpl.MessageState `protogen:"open.v1"`
+	unknownFields protoimpl.UnknownFields
+	sizeCache     protoimpl.SizeCache
+}
+
+func (x *CheckPolicyResponse) Reset() {
+	*x = CheckPolicyResponse{}
+	mi := &file_headscale_v1_policy_proto_msgTypes[5]
+	ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
+	ms.StoreMessageInfo(mi)
+}
+
+func (x *CheckPolicyResponse) String() string {
+	return protoimpl.X.MessageStringOf(x)
+}
+
+func (*CheckPolicyResponse) ProtoMessage() {}
+
+func (x *CheckPolicyResponse) ProtoReflect() protoreflect.Message {
+	mi := &file_headscale_v1_policy_proto_msgTypes[5]
+	if x != nil {
+		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
+		if ms.LoadMessageInfo() == nil {
+			ms.StoreMessageInfo(mi)
+		}
+		return ms
+	}
+	return mi.MessageOf(x)
+}
+
+// Deprecated: Use CheckPolicyResponse.ProtoReflect.Descriptor instead.
+func (*CheckPolicyResponse) Descriptor() ([]byte, []int) {
+	return file_headscale_v1_policy_proto_rawDescGZIP(), []int{5}
+}
+
 var File_headscale_v1_policy_proto protoreflect.FileDescriptor
 
 const file_headscale_v1_policy_proto_rawDesc = "" +
@@ -221,7 +301,10 @@ const file_headscale_v1_policy_proto_rawDesc = "" +
 	"\x11GetPolicyResponse\x12\x16\n" +
 	"\x06policy\x18\x01 \x01(\tR\x06policy\x129\n" +
 	"\n" +
-	"updated_at\x18\x02 \x01(\v2\x1a.google.protobuf.TimestampR\tupdatedAtB)Z'github.com/juanfont/headscale/gen/go/v1b\x06proto3"
+	"updated_at\x18\x02 \x01(\v2\x1a.google.protobuf.TimestampR\tupdatedAt\",\n" +
+	"\x12CheckPolicyRequest\x12\x16\n" +
+	"\x06policy\x18\x01 \x01(\tR\x06policy\"\x15\n" +
+	"\x13CheckPolicyResponseB)Z'github.com/juanfont/headscale/gen/go/v1b\x06proto3"
 
 var (
 	file_headscale_v1_policy_proto_rawDescOnce sync.Once
@@ -235,17 +318,19 @@ func file_headscale_v1_policy_proto_rawDescGZIP() []byte {
 	return file_headscale_v1_policy_proto_rawDescData
 }
 
-var file_headscale_v1_policy_proto_msgTypes = make([]protoimpl.MessageInfo, 4)
+var file_headscale_v1_policy_proto_msgTypes = make([]protoimpl.MessageInfo, 6)
 var file_headscale_v1_policy_proto_goTypes = []any{
 	(*SetPolicyRequest)(nil),      // 0: headscale.v1.SetPolicyRequest
 	(*SetPolicyResponse)(nil),     // 1: headscale.v1.SetPolicyResponse
 	(*GetPolicyRequest)(nil),      // 2: headscale.v1.GetPolicyRequest
 	(*GetPolicyResponse)(nil),     // 3: headscale.v1.GetPolicyResponse
-	(*timestamppb.Timestamp)(nil), // 4: google.protobuf.Timestamp
+	(*CheckPolicyRequest)(nil),    // 4: headscale.v1.CheckPolicyRequest
+	(*CheckPolicyResponse)(nil),   // 5: headscale.v1.CheckPolicyResponse
+	(*timestamppb.Timestamp)(nil), // 6: google.protobuf.Timestamp
 }
 var file_headscale_v1_policy_proto_depIdxs = []int32{
-	4, // 0: headscale.v1.SetPolicyResponse.updated_at:type_name -> google.protobuf.Timestamp
-	4, // 1: headscale.v1.GetPolicyResponse.updated_at:type_name -> google.protobuf.Timestamp
+	6, // 0: headscale.v1.SetPolicyResponse.updated_at:type_name -> google.protobuf.Timestamp
+	6, // 1: headscale.v1.GetPolicyResponse.updated_at:type_name -> google.protobuf.Timestamp
 	2, // [2:2] is the sub-list for method output_type
 	2, // [2:2] is the sub-list for method input_type
 	2, // [2:2] is the sub-list for extension type_name
@@ -264,7 +349,7 @@ func file_headscale_v1_policy_proto_init() {
 			GoPackagePath: reflect.TypeOf(x{}).PkgPath(),
 			RawDescriptor: unsafe.Slice(unsafe.StringData(file_headscale_v1_policy_proto_rawDesc), len(file_headscale_v1_policy_proto_rawDesc)),
 			NumEnums:      0,
-			NumMessages:   4,
+			NumMessages:   6,
 			NumExtensions: 0,
 			NumServices:   0,
 		},

gen/openapiv2/headscale/v1/headscale.swagger.json

@@ -660,6 +660,38 @@
         ]
       }
     },
+    "/api/v1/policy/check": {
+      "post": {
+        "operationId": "HeadscaleService_CheckPolicy",
+        "responses": {
+          "200": {
+            "description": "A successful response.",
+            "schema": {
+              "$ref": "#/definitions/v1CheckPolicyResponse"
+            }
+          },
+          "default": {
+            "description": "An unexpected error response.",
+            "schema": {
+              "$ref": "#/definitions/rpcStatus"
+            }
+          }
+        },
+        "parameters": [
+          {
+            "name": "body",
+            "in": "body",
+            "required": true,
+            "schema": {
+              "$ref": "#/definitions/v1CheckPolicyRequest"
+            }
+          }
+        ],
+        "tags": [
+          "HeadscaleService"
+        ]
+      }
+    },
     "/api/v1/preauthkey": {
       "get": {
         "operationId": "HeadscaleService_ListPreAuthKeys",
@@ -1044,6 +1076,17 @@
         }
       }
     },
+    "v1CheckPolicyRequest": {
+      "type": "object",
+      "properties": {
+        "policy": {
+          "type": "string"
+        }
+      }
+    },
+    "v1CheckPolicyResponse": {
+      "type": "object"
+    },
     "v1CreateApiKeyRequest": {
       "type": "object",
       "properties": {

go.mod

@@ -54,6 +54,7 @@ require (
 	gopkg.in/yaml.v3 v3.0.1
 	gorm.io/driver/postgres v1.6.0
 	gorm.io/gorm v1.31.1
+	pgregory.net/rapid v1.2.0
 	tailscale.com v1.96.5
 	zombiezen.com/go/postgrestest v1.0.1
 )
@@ -96,11 +97,14 @@ require (
 	atomicgo.dev/schedule v0.1.0 // indirect
 	dario.cat/mergo v1.0.2 // indirect
 	filippo.io/edwards25519 v1.2.0 // indirect
+	fyne.io/systray v1.11.1-0.20250812065214-4856ac3adc3c // indirect
 	github.com/Azure/go-ansiterm v0.0.0-20250102033503-faa5f7b0171c // indirect
+	github.com/Kodeworks/golang-image-ico v0.0.0-20141118225523-73f0f4cfade9 // indirect
 	github.com/Microsoft/go-winio v0.6.2 // indirect
 	github.com/Nvveen/Gotty v0.0.0-20120604004816-cd527374f1e5 // indirect
 	github.com/akutz/memconn v0.1.0 // indirect
 	github.com/alexbrainman/sspi v0.0.0-20250919150558-7d374ff0d59e // indirect
+	github.com/atotto/clipboard v0.1.4 // indirect
 	github.com/aws/aws-sdk-go-v2 v1.41.1 // indirect
 	github.com/aws/aws-sdk-go-v2/config v1.32.7 // indirect
 	github.com/aws/aws-sdk-go-v2/credentials v1.19.7 // indirect
@@ -111,6 +115,7 @@ require (
 	github.com/aws/aws-sdk-go-v2/service/internal/accept-encoding v1.13.4 // indirect
 	github.com/aws/aws-sdk-go-v2/service/internal/presigned-url v1.13.17 // indirect
 	github.com/aws/aws-sdk-go-v2/service/signin v1.0.5 // indirect
+	github.com/aws/aws-sdk-go-v2/service/ssm v1.45.0 // indirect
 	github.com/aws/aws-sdk-go-v2/service/sso v1.30.9 // indirect
 	github.com/aws/aws-sdk-go-v2/service/ssooidc v1.35.13 // indirect
 	github.com/aws/aws-sdk-go-v2/service/sts v1.41.6 // indirect
@@ -135,6 +140,7 @@ require (
 	github.com/dustin/go-humanize v1.0.1 // indirect
 	github.com/felixge/fgprof v0.9.5 // indirect
 	github.com/felixge/httpsnoop v1.0.4 // indirect
+	github.com/fogleman/gg v1.3.0 // indirect
 	github.com/fxamacker/cbor/v2 v2.9.0 // indirect
 	github.com/gaissmai/bart v0.26.1 // indirect
 	github.com/glebarez/go-sqlite v1.22.0 // indirect
@@ -145,6 +151,7 @@ require (
 	github.com/go-viper/mapstructure/v2 v2.5.0 // indirect
 	github.com/godbus/dbus/v5 v5.2.2 // indirect
 	github.com/golang-jwt/jwt/v5 v5.3.1 // indirect
+	github.com/golang/freetype v0.0.0-20170609003504-e2365dfdc4a0 // indirect
 	github.com/golang/groupcache v0.0.0-20241129210726-2c02b8208cf8 // indirect
 	github.com/golang/protobuf v1.5.4 // indirect
 	github.com/google/btree v1.1.3 // indirect
@@ -165,8 +172,10 @@ require (
 	github.com/jackc/puddle/v2 v2.2.2 // indirect
 	github.com/jinzhu/inflection v1.0.0 // indirect
 	github.com/jinzhu/now v1.1.5 // indirect
+	github.com/jmespath/go-jmespath v0.4.0 // indirect
 	github.com/jsimonetti/rtnetlink v1.4.2 // indirect
 	github.com/kamstrup/intmap v0.5.2 // indirect
+	github.com/kballard/go-shellquote v0.0.0-20180428030007-95032a82bc51 // indirect
 	github.com/klauspost/compress v1.18.3 // indirect
 	github.com/lib/pq v1.11.1 // indirect
 	github.com/lithammer/fuzzysearch v1.1.8 // indirect
@@ -189,6 +198,7 @@ require (
 	github.com/opencontainers/image-spec v1.1.1 // indirect
 	github.com/opencontainers/runc v1.3.2 // indirect
 	github.com/pelletier/go-toml/v2 v2.2.4 // indirect
+	github.com/peterbourgon/ff/v3 v3.4.0 // indirect
 	github.com/petermattis/goid v0.0.0-20260113132338-7c7de50cc741 // indirect
 	github.com/pires/go-proxyproto v0.9.2 // indirect
 	github.com/pkg/errors v0.9.1 // indirect
@@ -200,6 +210,7 @@ require (
 	github.com/safchain/ethtool v0.7.0 // indirect
 	github.com/sagikazarmark/locafero v0.12.0 // indirect
 	github.com/sirupsen/logrus v1.9.4 // indirect
+	github.com/skip2/go-qrcode v0.0.0-20200617195104-da1b6568686e // indirect
 	github.com/spf13/afero v1.15.0 // indirect
 	github.com/spf13/cast v1.10.0 // indirect
 	github.com/spf13/pflag v1.0.10 // indirect
@@ -210,6 +221,7 @@ require (
 	github.com/tailscale/setec v0.0.0-20260115174028-19d190c5556d // indirect
 	github.com/tailscale/web-client-prebuilt v0.0.0-20251127225136-f19339b67368 // indirect
 	github.com/tailscale/wireguard-go v0.0.0-20250716170648-1d0488a3d7da // indirect
+	github.com/toqueteos/webbrowser v1.2.0 // indirect
 	github.com/x448/float16 v0.8.4 // indirect
 	github.com/xeipuuv/gojsonpointer v0.0.0-20190905194746-02993c407bfb // indirect
 	github.com/xeipuuv/gojsonreference v0.0.0-20180127040603-bd5ef7bd5415 // indirect
@@ -224,6 +236,7 @@ require (
 	go.yaml.in/yaml/v2 v2.4.3 // indirect
 	go.yaml.in/yaml/v3 v3.0.4 // indirect
 	go4.org/mem v0.0.0-20240501181205-ae6ca9944745 // indirect
+	golang.org/x/image v0.27.0 // indirect
 	golang.org/x/mod v0.35.0 // indirect
 	golang.org/x/sys v0.43.0 // indirect
 	golang.org/x/term v0.42.0 // indirect
@@ -233,10 +246,15 @@ require (
 	golang.zx2c4.com/wintun v0.0.0-20230126152724-0fa3db229ce2 // indirect
 	golang.zx2c4.com/wireguard/windows v0.5.3 // indirect
 	google.golang.org/genproto/googleapis/rpc v0.0.0-20260401024825-9d38bb4040a9 // indirect
+	k8s.io/client-go v0.34.0 // indirect
+	sigs.k8s.io/yaml v1.6.0 // indirect
+	software.sslmate.com/src/go-pkcs12 v0.4.0 // indirect
 )
 
 tool (
 	golang.org/x/tools/cmd/stress
 	golang.org/x/tools/cmd/stringer
+	tailscale.com/cmd/tailscale
 	tailscale.com/cmd/viewer
+	tailscale.com/tstest/mts
 )

go.sum

@@ -14,10 +14,14 @@ filippo.io/edwards25519 v1.2.0 h1:crnVqOiS4jqYleHd9vaKZ+HKtHfllngJIiOpNpoJsjo=
 filippo.io/edwards25519 v1.2.0/go.mod h1:xzAOLCNug/yB62zG1bQ8uziwrIqIuxhctzJT18Q77mc=
 filippo.io/mkcert v1.4.4 h1:8eVbbwfVlaqUM7OwuftKc2nuYOoTDQWqsoXmzoXZdbc=
 filippo.io/mkcert v1.4.4/go.mod h1:VyvOchVuAye3BoUsPUOOofKygVwLV2KQMVFJNRq+1dA=
+fyne.io/systray v1.11.1-0.20250812065214-4856ac3adc3c h1:km4PIleGtbbF1oxmFQuO93CyNCldwuRTPB8WlzNWNZs=
+fyne.io/systray v1.11.1-0.20250812065214-4856ac3adc3c/go.mod h1:RVwqP9nYMo7h5zViCBHri2FgjXF7H2cub7MAq4NSoLs=
 github.com/Azure/go-ansiterm v0.0.0-20250102033503-faa5f7b0171c h1:udKWzYgxTojEKWjV8V+WSxDXJ4NFATAsZjh8iIbsQIg=
 github.com/Azure/go-ansiterm v0.0.0-20250102033503-faa5f7b0171c/go.mod h1:xomTg63KZ2rFqZQzSB4Vz2SUXa1BpHTVz9L5PTmPC4E=
 github.com/BurntSushi/toml v1.5.0 h1:W5quZX/G/csjUnuI8SUYlsHs9M38FC7znL0lIO+DvMg=
 github.com/BurntSushi/toml v1.5.0/go.mod h1:ukJfTF/6rtPPRCnwkur4qwRxa8vTRFBF0uk2lLoLwho=
+github.com/Kodeworks/golang-image-ico v0.0.0-20141118225523-73f0f4cfade9 h1:1ltqoej5GtaWF8jaiA49HwsZD459jqm9YFz9ZtMFpQA=
+github.com/Kodeworks/golang-image-ico v0.0.0-20141118225523-73f0f4cfade9/go.mod h1:7uhhqiBaR4CpN0k9rMjOtjpcfGd6DG2m04zQxKnWQ0I=
 github.com/MarvinJWendt/testza v0.1.0/go.mod h1:7AxNvlfeHP7Z/hDQ5JtE3OKYT3XFUeLCDE2DQninSqs=
 github.com/MarvinJWendt/testza v0.2.1/go.mod h1:God7bhG8n6uQxwdScay+gjm9/LnO4D3kkcZX4hv9Rp8=
 github.com/MarvinJWendt/testza v0.2.8/go.mod h1:nwIcjmr0Zz+Rcwfh3/4UhBp7ePKVhuBExvZqnKYWlII=
@@ -40,6 +44,8 @@ github.com/anmitsu/go-shlex v0.0.0-20200514113438-38f4b401e2be/go.mod h1:ySMOLuW
 github.com/arl/statsviz v0.8.0 h1:O6GjjVxEDxcByAucOSl29HaGYLXsuwA3ujJw8H9E7/U=
 github.com/arl/statsviz v0.8.0/go.mod h1:XlrbiT7xYT03xaW9JMMfD8KFUhBOESJwfyNJu83PbB0=
 github.com/atomicgo/cursor v0.0.1/go.mod h1:cBON2QmmrysudxNBFthvMtN32r3jxVRIvzkUiF/RuIk=
+github.com/atotto/clipboard v0.1.4 h1:EH0zSVneZPSuFR11BlR9YppQTVDbh5+16AmcJi4g1z4=
+github.com/atotto/clipboard v0.1.4/go.mod h1:ZY9tmq7sm5xIbd9bOK4onWV4S6X0u6GY7Vn0Yu86PYI=
 github.com/aws/aws-sdk-go-v2 v1.41.1 h1:ABlyEARCDLN034NhxlRUSZr4l71mh+T5KAeGh6cerhU=
 github.com/aws/aws-sdk-go-v2 v1.41.1/go.mod h1:MayyLB8y+buD9hZqkCW3kX1AKq07Y5pXxtgB+rRFhz0=
 github.com/aws/aws-sdk-go-v2/aws/protocol/eventstream v1.7.4 h1:489krEF9xIGkOaaX3CE/Be2uWjiXrkCH6gUX+bZA/BU=
@@ -164,6 +170,8 @@ github.com/felixge/fgprof v0.9.5 h1:8+vR6yu2vvSKn08urWyEuxx75NWPEvybbkBirEpsbVY=
 github.com/felixge/fgprof v0.9.5/go.mod h1:yKl+ERSa++RYOs32d8K6WEXCB4uXdLls4ZaZPpayhMM=
 github.com/felixge/httpsnoop v1.0.4 h1:NFTV2Zj1bL4mc9sqWACXbQFVBBg2W3GPvqp8/ESS2Wg=
 github.com/felixge/httpsnoop v1.0.4/go.mod h1:m8KPJKqk1gH5J9DgRY2ASl2lWCfGKXixSwevea8zH2U=
+github.com/fogleman/gg v1.3.0 h1:/7zJX8F6AaYQc57WQCyN9cAIz+4bCJGO9B+dyW29am8=
+github.com/fogleman/gg v1.3.0/go.mod h1:R/bRT+9gY/C5z7JzPU0zXsXHKM4/ayA+zqcVNZzPa1k=
 github.com/frankban/quicktest v1.14.6 h1:7Xjx+VpznH+oBnejlPUj8oUpdxnVs4f8XU8WnHkI4W8=
 github.com/frankban/quicktest v1.14.6/go.mod h1:4ptaffx2x8+WTWXmUCuVU6aPUX1/Mz7zb5vbUoiM6w0=
 github.com/fsnotify/fsnotify v1.9.0 h1:2Ml+OJNzbYCTzsxtv8vKSFD9PbJjmhYF14k/jKC7S9k=
@@ -212,6 +220,8 @@ github.com/gofrs/uuid/v5 v5.4.0 h1:EfbpCTjqMuGyq5ZJwxqzn3Cbr2d0rUZU7v5ycAk/e/0=
 github.com/gofrs/uuid/v5 v5.4.0/go.mod h1:CDOjlDMVAtN56jqyRUZh58JT31Tiw7/oQyEXZV+9bD8=
 github.com/golang-jwt/jwt/v5 v5.3.1 h1:kYf81DTWFe7t+1VvL7eS+jKFVWaUnK9cB1qbwn63YCY=
 github.com/golang-jwt/jwt/v5 v5.3.1/go.mod h1:fxCRLWMO43lRc8nhHWY6LGqRcf+1gQWArsqaEUEa5bE=
+github.com/golang/freetype v0.0.0-20170609003504-e2365dfdc4a0 h1:DACJavvAHhabrF08vX0COfcOBJRhZ8lUbR+ZWIs0Y5g=
+github.com/golang/freetype v0.0.0-20170609003504-e2365dfdc4a0/go.mod h1:E/TSTwGwJL78qG/PmXZO1EjYhfJinVAhrmmHX6Z8B9k=
 github.com/golang/groupcache v0.0.0-20241129210726-2c02b8208cf8 h1:f+oWsMOmNPc8JmEHVZIycC7hBoQxHH9pNKQORJNozsQ=
 github.com/golang/groupcache v0.0.0-20241129210726-2c02b8208cf8/go.mod h1:wcDNUvekVysuuOpQKo3191zZyTpiI6se1N1ULghS0sw=
 github.com/golang/protobuf v1.5.4 h1:i7eJL8qZTpSEXOPTxNKhASYpMn+8e5Q6AdndVa1dWek=
@@ -284,11 +294,15 @@ github.com/jinzhu/now v1.1.5 h1:/o9tlHleP7gOFmsnYNz3RGnqzefHA47wQpKrrdTIwXQ=
 github.com/jinzhu/now v1.1.5/go.mod h1:d3SSVoowX0Lcu0IBviAWJpolVfI5UJVZZ7cO71lE/z8=
 github.com/jmespath/go-jmespath v0.4.0 h1:BEgLn5cpjn8UN1mAw4NjwDrS35OdebyEtFe+9YPoQUg=
 github.com/jmespath/go-jmespath v0.4.0/go.mod h1:T8mJZnbsbmF+m6zOOFylbeCJqk5+pHWvzYPziyZiYoo=
+github.com/jmespath/go-jmespath/internal/testify v1.5.1 h1:shLQSRRSCCPj3f2gpwzGwWFoC7ycTf1rcQZHOlsJ6N8=
+github.com/jmespath/go-jmespath/internal/testify v1.5.1/go.mod h1:L3OGu8Wl2/fWfCI6z80xFu9LTZmf1ZRjMHUOPmWr69U=
 github.com/josharian/intern v1.0.0/go.mod h1:5DoeVV0s6jJacbCEi61lwdGj/aVlrQvzHFFd8Hwg//Y=
 github.com/jsimonetti/rtnetlink v1.4.2 h1:Df9w9TZ3npHTyDn0Ev9e1uzmN2odmXd0QX+J5GTEn90=
 github.com/jsimonetti/rtnetlink v1.4.2/go.mod h1:92s6LJdE+1iOrw+F2/RO7LYI2Qd8pPpFNNUYW06gcoM=
 github.com/kamstrup/intmap v0.5.2 h1:qnwBm1mh4XAnW9W9Ue9tZtTff8pS6+s6iKF6JRIV2Dk=
 github.com/kamstrup/intmap v0.5.2/go.mod h1:gWUVWHKzWj8xpJVFf5GC0O26bWmv3GqdnIX/LMT6Aq4=
+github.com/kballard/go-shellquote v0.0.0-20180428030007-95032a82bc51 h1:Z9n2FFNUXsshfwJMBgNA0RU6/i7WVaAegv3PtuIHPMs=
+github.com/kballard/go-shellquote v0.0.0-20180428030007-95032a82bc51/go.mod h1:CzGEWj7cYgsdH8dAjBGEr58BoE7ScuLd+fwFZ44+/x8=
 github.com/klauspost/compress v1.18.3 h1:9PJRvfbmTabkOX8moIpXPbMMbYN60bWImDDU7L+/6zw=
 github.com/klauspost/compress v1.18.3/go.mod h1:R0h/fSBs8DE4ENlcrlib3PsXS61voFxhIs2DeRhCvJ4=
 github.com/klauspost/cpuid/v2 v2.0.9/go.mod h1:FInQzS24/EEf25PyTYn52gqo7WaD8xa0213Md/qVLRg=
@@ -370,6 +384,8 @@ github.com/ory/dockertest/v3 v3.12.0 h1:3oV9d0sDzlSQfHtIaB5k6ghUCVMVLpAY8hwrqoCy
 github.com/ory/dockertest/v3 v3.12.0/go.mod h1:aKNDTva3cp8dwOWwb9cWuX84aH5akkxXRvO7KCwWVjE=
 github.com/pelletier/go-toml/v2 v2.2.4 h1:mye9XuhQ6gvn5h28+VilKrrPoQVanw5PMw/TB0t5Ec4=
 github.com/pelletier/go-toml/v2 v2.2.4/go.mod h1:2gIqNv+qfxSVS7cM2xJQKtLSTLUE9V8t9Stt+h56mCY=
+github.com/peterbourgon/ff/v3 v3.4.0 h1:QBvM/rizZM1cB0p0lGMdmR7HxZeI/ZrBWB4DqLkMUBc=
+github.com/peterbourgon/ff/v3 v3.4.0/go.mod h1:zjJVUhx+twciwfDl0zBcFzl4dW8axCRyXE/eKY9RztQ=
 github.com/petermattis/goid v0.0.0-20250813065127-a731cc31b4fe/go.mod h1:pxMtw7cyUw6B2bRH0ZBANSPg+AoSud1I1iyJHI69jH4=
 github.com/petermattis/goid v0.0.0-20260113132338-7c7de50cc741 h1:KPpdlQLZcHfTMQRi6bFQ7ogNO0ltFT4PmtwTLW4W+14=
 github.com/petermattis/goid v0.0.0-20260113132338-7c7de50cc741/go.mod h1:pxMtw7cyUw6B2bRH0ZBANSPg+AoSud1I1iyJHI69jH4=
@@ -430,6 +446,8 @@ github.com/sergi/go-diff v1.3.2-0.20230802210424-5b0b94c5c0d3 h1:n661drycOFuPLCN
 github.com/sergi/go-diff v1.3.2-0.20230802210424-5b0b94c5c0d3/go.mod h1:A0bzQcvG0E7Rwjx0REVgAGH58e96+X0MeOfepqsbeW4=
 github.com/sirupsen/logrus v1.9.4 h1:TsZE7l11zFCLZnZ+teH4Umoq5BhEIfIzfRDZ1Uzql2w=
 github.com/sirupsen/logrus v1.9.4/go.mod h1:ftWc9WdOfJ0a92nsE2jF5u5ZwH8Bv2zdeOC42RjbV2g=
+github.com/skip2/go-qrcode v0.0.0-20200617195104-da1b6568686e h1:MRM5ITcdelLK2j1vwZ3Je0FKVCfqOLp5zO6trqMLYs0=
+github.com/skip2/go-qrcode v0.0.0-20200617195104-da1b6568686e/go.mod h1:XV66xRDqSt+GTGFMVlhk3ULuV0y9ZmzeVGR4mloJI3M=
 github.com/spf13/afero v1.15.0 h1:b/YBCLWAJdFWJTN9cLhiXXcD7mzKn9Dm86dNnfyQw1I=
 github.com/spf13/afero v1.15.0/go.mod h1:NC2ByUVxtQs4b3sIUphxK0NioZnmxgyCrfzeuq8lxMg=
 github.com/spf13/cast v1.10.0 h1:h2x0u2shc1QuLHfxi+cTJvs30+ZAHOGRic8uyGTDWxY=
@@ -487,6 +505,8 @@ github.com/tcnksm/go-latest v0.0.0-20170313132115-e3007ae9052e h1:IWllFTiDjjLIf2
 github.com/tcnksm/go-latest v0.0.0-20170313132115-e3007ae9052e/go.mod h1:d7u6HkTYKSv5m6MCKkOQlHwaShTMl3HjqSGW3XtVhXM=
 github.com/tink-crypto/tink-go/v2 v2.6.0 h1:+KHNBHhWH33Vn+igZWcsgdEPUxKwBMEe0QC60t388v4=
 github.com/tink-crypto/tink-go/v2 v2.6.0/go.mod h1:2WbBA6pfNsAfBwDCggboaHeB2X29wkU8XHtGwh2YIk8=
+github.com/toqueteos/webbrowser v1.2.0 h1:tVP/gpK69Fx+qMJKsLE7TD8LuGWPnEV71wBN9rrstGQ=
+github.com/toqueteos/webbrowser v1.2.0/go.mod h1:XWoZq4cyp9WeUeak7w7LXRUQf1F1ATJMir8RTqb4ayM=
 github.com/u-root/u-root v0.14.0 h1:Ka4T10EEML7dQ5XDvO9c3MBN8z4nuSnGjcd1jmU2ivg=
 github.com/u-root/u-root v0.14.0/go.mod h1:hAyZorapJe4qzbLWlAkmSVCJGbfoU9Pu4jpJ1WMluqE=
 github.com/u-root/uio v0.0.0-20240224005618-d2acac8f3701 h1:pyC9PaHYZFgEKFdlp3G8RaCKgVpHZnecvArXvPXcFkM=
@@ -631,6 +651,9 @@ gopkg.in/check.v1 v1.0.0-20201130134442-10cb98267c6c h1:Hei/4ADfdWqJk1ZMxUNpqntN
 gopkg.in/check.v1 v1.0.0-20201130134442-10cb98267c6c/go.mod h1:JHkPIbrfpd72SG/EVd6muEfDQjcINNoR0C8j2r3qZ4Q=
 gopkg.in/yaml.v2 v2.2.2/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
 gopkg.in/yaml.v2 v2.2.4/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
+gopkg.in/yaml.v2 v2.2.8/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
+gopkg.in/yaml.v2 v2.4.0 h1:D8xgwECY7CYvx+Y2n4sBz93Jn9JRvxdiyyo8CTfuKaY=
+gopkg.in/yaml.v2 v2.4.0/go.mod h1:RDklbk79AGWmwhnvt/jBztapEOGDOx6ZbXqjP6csGnQ=
 gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
 gopkg.in/yaml.v3 v3.0.0-20210107192922-496545a6307b/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
 gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
@@ -647,6 +670,8 @@ honnef.co/go/tools v0.7.0 h1:w6WUp1VbkqPEgLz4rkBzH/CSU6HkoqNLp6GstyTx3lU=
 honnef.co/go/tools v0.7.0/go.mod h1:pm29oPxeP3P82ISxZDgIYeOaf9ta6Pi0EWvCFoLG2vc=
 howett.net/plist v1.0.0 h1:7CrbWYbPPO/PyNy38b2EB/+gYbjCe2DXBxgtOOZbSQM=
 howett.net/plist v1.0.0/go.mod h1:lqaXoTrLY4hg8tnEzNru53gicrbv7rrk+2xJA/7hw9g=
+k8s.io/client-go v0.34.0 h1:YoWv5r7bsBfb0Hs2jh8SOvFbKzzxyNo0nSb0zC19KZo=
+k8s.io/client-go v0.34.0/go.mod h1:ozgMnEKXkRjeMvBZdV1AijMHLTh3pbACPvK7zFR+QQY=
 modernc.org/cc/v4 v4.27.1 h1:9W30zRlYrefrDV2JE2O8VDtJ1yPGownxciz5rrbQZis=
 modernc.org/cc/v4 v4.27.1/go.mod h1:uVtb5OGqUKpoLWhqwNQo/8LwvoiEBLvZXIQ/SmO6mL0=
 modernc.org/ccgo/v4 v4.32.0 h1:hjG66bI/kqIPX1b2yT6fr/jt+QedtP2fqojG2VrFuVw=
@@ -677,6 +702,8 @@ modernc.org/token v1.1.0 h1:Xl7Ap9dKaEs5kLoOQeQmPWevfnk/DM5qcLcYlA8ys6Y=
 modernc.org/token v1.1.0/go.mod h1:UGzOrNV1mAFSEB63lOFHIpNRUVMvYTc6yu1SMY/XTDM=
 pgregory.net/rapid v1.2.0 h1:keKAYRcjm+e1F0oAuU5F5+YPAWcyxNNRK2wud503Gnk=
 pgregory.net/rapid v1.2.0/go.mod h1:PY5XlDGj0+V1FCq0o192FdRhpKHGTRIWBgqjDBTrq04=
+sigs.k8s.io/yaml v1.6.0 h1:G8fkbMSAFqgEFgh4b1wmtzDnioxFCUgTZhlbj5P9QYs=
+sigs.k8s.io/yaml v1.6.0/go.mod h1:796bPqUfzR/0jLAl6XjHl3Ck7MiyVv8dbTdyT3/pMf4=
 software.sslmate.com/src/go-pkcs12 v0.4.0 h1:H2g08FrTvSFKUj+D309j1DPfk5APnIdAQAB8aEykJ5k=
 software.sslmate.com/src/go-pkcs12 v0.4.0/go.mod h1:Qiz0EyvDRJjjxGyUQa2cCNZn/wMyzrRJ/qcDXOQazLI=
 tailscale.com v1.96.5 h1:gNkfA/KSZAl6jCH9cj8urq00HRWItDDTtGsyATI89jA=

hscontrol/app.go

@@ -276,6 +276,31 @@ func (h *Headscale) scheduledTasks(ctx context.Context) {
 		extraRecordsUpdate = make(chan []tailcfg.DNSRecord)
 	}
 
+	var (
+		haProber     *state.HAHealthProber
+		haHealthChan <-chan time.Time
+	)
+	if h.cfg.Node.Routes.HA.ProbeInterval > 0 {
+		haProber = state.NewHAHealthProber(
+			h.state,
+			h.cfg.Node.Routes.HA,
+			h.cfg.ServerURL,
+			h.mapBatcher.IsConnected,
+		)
+
+		haTicker := time.NewTicker(h.cfg.Node.Routes.HA.ProbeInterval)
+		defer haTicker.Stop()
+
+		haHealthChan = haTicker.C
+
+		log.Info().
+			Dur("interval", h.cfg.Node.Routes.HA.ProbeInterval).
+			Dur("timeout", h.cfg.Node.Routes.HA.ProbeTimeout).
+			Msg("HA subnet router health probing enabled")
+	} else {
+		haHealthChan = make(<-chan time.Time)
+	}
+
 	for {
 		select {
 		case <-ctx.Done():
@@ -332,6 +357,9 @@ func (h *Headscale) scheduledTasks(ctx context.Context) {
 			h.cfg.TailcfgDNSConfig.ExtraRecords = records
 
 			h.Change(change.ExtraRecords())
+
+		case <-haHealthChan:
+			haProber.ProbeOnce(ctx, h.Change)
 		}
 	}
 }
@@ -460,6 +488,20 @@ func (h *Headscale) ensureUnixSocketIsAbsent() error {
 	return os.Remove(h.cfg.UnixSocket)
 }
 
+// securityHeaders sets baseline response headers on every HTTP response:
+// deny framing (clickjacking), forbid MIME-type sniffing, drop the Referer
+// header on outbound navigation. Cheap defense-in-depth for HTML surfaces.
+func securityHeaders(next http.Handler) http.Handler {
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		h := w.Header()
+		h.Set("X-Frame-Options", "DENY")
+		h.Set("Content-Security-Policy", "frame-ancestors 'none'")
+		h.Set("X-Content-Type-Options", "nosniff")
+		h.Set("Referrer-Policy", "no-referrer")
+		next.ServeHTTP(w, r)
+	})
+}
+
 func (h *Headscale) createRouter(grpcMux *grpcRuntime.ServeMux) *chi.Mux {
 	r := chi.NewRouter()
 	r.Use(metrics.Collector(metrics.CollectorOpts{
@@ -473,6 +515,7 @@ func (h *Headscale) createRouter(grpcMux *grpcRuntime.ServeMux) *chi.Mux {
 	r.Use(middleware.RealIP)
 	r.Use(middleware.RequestLogger(&zerologRequestLogger{}))
 	r.Use(middleware.Recoverer)
+	r.Use(securityHeaders)
 
 	r.Post(ts2021UpgradePath, h.NoiseUpgradeHandler)
 
@@ -509,6 +552,10 @@ func (h *Headscale) createRouter(grpcMux *grpcRuntime.ServeMux) *chi.Mux {
 		r.Use(h.httpAuthenticationMiddleware)
 		r.HandleFunc("/v1/*", grpcMux.ServeHTTP)
 	})
+	// Ping response endpoint: receives HEAD from clients responding
+	// to a PingRequest. The unguessable ping ID serves as authentication.
+	r.Head("/machine/ping-response", h.PingResponseHandler)
+
 	r.Get("/favicon.ico", FaviconHandler)
 	r.Get("/", BlankHandler)
 
@@ -1109,6 +1156,11 @@ func (h *Headscale) StartBatcherForTest(tb testing.TB) {
 	tb.Cleanup(func() { h.mapBatcher.Close() })
 }
 
+// MapBatcher returns the map response batcher (for test use).
+func (h *Headscale) MapBatcher() *mapper.Batcher {
+	return h.mapBatcher
+}
+
 // StartEphemeralGCForTest starts the ephemeral node garbage collector.
 // It registers a cleanup function on tb to stop the collector.
 // It panics when called outside of tests.

hscontrol/app_test.go

@@ -0,0 +1,26 @@
+package hscontrol
+
+import (
+	"context"
+	"net/http"
+	"net/http/httptest"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestSecurityHeaders(t *testing.T) {
+	handler := securityHeaders(http.HandlerFunc(func(w http.ResponseWriter, _ *http.Request) {
+		w.WriteHeader(http.StatusOK)
+	}))
+
+	rec := httptest.NewRecorder()
+	req := httptest.NewRequestWithContext(context.Background(), http.MethodGet, "/", nil)
+	handler.ServeHTTP(rec, req)
+
+	h := rec.Result().Header
+	assert.Equal(t, "DENY", h.Get("X-Frame-Options"))
+	assert.Equal(t, "frame-ancestors 'none'", h.Get("Content-Security-Policy"))
+	assert.Equal(t, "nosniff", h.Get("X-Content-Type-Options"))
+	assert.Equal(t, "no-referrer", h.Get("Referrer-Policy"))
+}

hscontrol/assets/style.css

@@ -11,11 +11,46 @@
   --md-typeset-a-color: var(--md-primary-fg-color);
   --md-text-font: "Roboto", -apple-system, BlinkMacSystemFont, "Segoe UI", "Helvetica Neue", Arial, sans-serif;
   --md-code-font: "Roboto Mono", "SF Mono", Monaco, "Cascadia Code", Consolas, "Courier New", monospace;
+  --hs-success: #059669;
+  --hs-success-bg: #d1fae5;
+  --hs-error: #dc2626;
+  --hs-error-bg: #fee2e2;
+  --hs-warning-text: #92400e;
+  --hs-warning-bg: #fef3c7;
+  --hs-warning-border: #f59e0b;
+  --hs-border: #e5e7eb;
+  --hs-bg: #ffffff;
+  --hs-focus-ring: #4051b5;
 }
 
-/* Base Typography */
+/* Dark mode */
+@media (prefers-color-scheme: dark) {
+  :root {
+    --md-default-fg-color: rgba(255, 255, 255, 0.87);
+    --md-default-fg-color--light: rgba(255, 255, 255, 0.6);
+    --md-default-fg-color--lighter: rgba(255, 255, 255, 0.38);
+    --md-default-fg-color--lightest: rgba(255, 255, 255, 0.07);
+    --md-code-fg-color: #c9d1d9;
+    --md-code-bg-color: #1e1e1e;
+    --md-primary-fg-color: #7b8fdb;
+    --md-accent-fg-color: #8fa4ff;
+    --md-typeset-a-color: var(--md-primary-fg-color);
+    --hs-success: #34d399;
+    --hs-success-bg: #064e3b;
+    --hs-error: #f87171;
+    --hs-error-bg: #450a0a;
+    --hs-warning-text: #fbbf24;
+    --hs-warning-bg: #451a03;
+    --hs-warning-border: #d97706;
+    --hs-border: #374151;
+    --hs-bg: #111827;
+    --hs-focus-ring: #7b8fdb;
+  }
+}
+
+/* Base Typography - 1rem (16px) avoids iOS auto-zoom on inputs */
 .md-typeset {
-  font-size: 0.8rem;
+  font-size: 1rem;
   line-height: 1.6;
   color: var(--md-default-fg-color);
   font-family: var(--md-text-font);
@@ -76,16 +111,33 @@
   padding-left: 2em;
 }
 
-/* Links */
+.md-typeset li {
+  margin-bottom: 0.25em;
+}
+
+/* Links - underline for accessibility (don't rely on color alone) */
 .md-typeset a {
   color: var(--md-typeset-a-color);
-  text-decoration: none;
+  text-decoration: underline;
+  text-decoration-thickness: 1px;
+  text-underline-offset: 2px;
   word-break: break-word;
+  cursor: pointer;
 }
 
 .md-typeset a:hover,
 .md-typeset a:focus {
   color: var(--md-accent-fg-color);
+  text-decoration-thickness: 2px;
+}
+
+/* Focus styles - visible ring for keyboard navigation */
+.md-typeset a:focus-visible,
+button:focus-visible,
+input:focus-visible {
+  outline: 2px solid var(--hs-focus-ring);
+  outline-offset: 2px;
+  border-radius: 2px;
 }
 
 /* Code (inline) */
@@ -118,6 +170,7 @@
   overflow-wrap: break-word;
   word-wrap: break-word;
   white-space: pre-wrap;
+  border-radius: 0.25rem;
 }
 
 /* Links in code */
@@ -125,6 +178,36 @@
   color: currentcolor;
 }
 
+/* Buttons - styled via CSS for hover/active/focus pseudo-classes */
+.md-typeset button {
+  display: inline-flex;
+  align-items: center;
+  justify-content: center;
+  padding: 0.75rem 1.5rem;
+  font-size: 1rem;
+  font-weight: 500;
+  font-family: var(--md-text-font);
+  line-height: 1;
+  color: #ffffff;
+  background-color: var(--md-primary-fg-color);
+  border: none;
+  border-radius: 0.375rem;
+  cursor: pointer;
+  min-height: 44px;
+  transition:
+    background-color 150ms ease-out,
+    box-shadow 150ms ease-out;
+}
+
+.md-typeset button:hover {
+  background-color: var(--md-accent-fg-color);
+  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.12);
+}
+
+.md-typeset button:active {
+  transform: translateY(1px);
+}
+
 /* Logo */
 .headscale-logo {
   display: block;
@@ -138,6 +221,17 @@
 @media (max-width: 768px) {
   .headscale-logo {
     width: 200px;
-    margin-left: 0;
+  }
+}
+
+/* Reduced motion */
+@media (prefers-reduced-motion: reduce) {
+  *,
+  *::before,
+  *::after {
+    animation-duration: 0.01ms !important;
+    animation-iteration-count: 1 !important;
+    transition-duration: 0.01ms !important;
+    scroll-behavior: auto !important;
   }
 }

hscontrol/auth.go

@@ -10,7 +10,6 @@ import (
 	"time"
 
 	"github.com/juanfont/headscale/hscontrol/types"
-	"github.com/juanfont/headscale/hscontrol/util"
 	"github.com/rs/zerolog/log"
 	"gorm.io/gorm"
 	"tailscale.com/tailcfg"
@@ -336,11 +335,10 @@ func registrationDataFromRequest(
 	req tailcfg.RegisterRequest,
 	machineKey key.MachinePublic,
 ) *types.RegistrationData {
-	hostname := util.EnsureHostname(
-		req.Hostinfo.View(),
-		machineKey.String(),
-		req.NodeKey.String(),
-	)
+	var hostname string
+	if req.Hostinfo != nil {
+		hostname = req.Hostinfo.Hostname
+	}
 
 	regData := &types.RegistrationData{
 		MachineKey: machineKey,

hscontrol/auth_tags_test.go

@@ -1119,3 +1119,72 @@ func TestReregistrationAppliesDefaultExpiry(t *testing.T) {
 	assert.True(t, node2.Expiry().Get().After(firstExpiry),
 		"re-registration expiry should be later than initial registration expiry")
 }
+
+// TestReregistrationZeroExpiryStaysNil tests that when a user-owned node
+// re-registers with zero client expiry and node.expiry is disabled (0),
+// the node's expiry stays nil rather than being set to a pointer to zero
+// time. Regression test for the else branch introduced in commit 6337a3db
+// which assigned `&regReq.Expiry` (pointer to time.Time{}) instead of nil,
+// causing the database row to hold `0001-01-01 00:00:00` instead of NULL.
+//
+// The same !regReq.Expiry.IsZero() gate at state.go:2221-2228 is shared by
+// the tags-only PreAuthKey path (createAndSaveNewNode also receives nil
+// when the client sends zero expiry), so this regression is covered for
+// tagged nodes by inspection.
+func TestReregistrationZeroExpiryStaysNil(t *testing.T) {
+	t.Parallel()
+
+	// node.expiry = 0 means "no default expiry"
+	app := createTestAppWithNodeExpiry(t, 0)
+
+	user := app.state.CreateUserForTest("node-owner")
+
+	pak, err := app.state.CreatePreAuthKey(user.TypedID(), true, false, nil, nil)
+	require.NoError(t, err)
+
+	machineKey := key.NewMachine()
+	nodeKey := key.NewNode()
+
+	// Initial registration with zero client expiry
+	regReq := tailcfg.RegisterRequest{
+		Auth: &tailcfg.RegisterResponseAuth{
+			AuthKey: pak.Key,
+		},
+		NodeKey: nodeKey.Public(),
+		Hostinfo: &tailcfg.Hostinfo{
+			Hostname: "reregister-zero-expiry",
+		},
+		Expiry: time.Time{},
+	}
+
+	resp, err := app.handleRegisterWithAuthKey(regReq, machineKey.Public())
+	require.NoError(t, err)
+	require.True(t, resp.MachineAuthorized)
+
+	node, found := app.state.GetNodeByNodeKey(nodeKey.Public())
+	require.True(t, found)
+	assert.False(t, node.Expiry().Valid(),
+		"initial registration with zero expiry and no default should leave expiry nil")
+
+	// Re-register with a new node key but same machine key + user
+	nodeKey2 := key.NewNode()
+	regReq2 := tailcfg.RegisterRequest{
+		Auth: &tailcfg.RegisterResponseAuth{
+			AuthKey: pak.Key,
+		},
+		NodeKey: nodeKey2.Public(),
+		Hostinfo: &tailcfg.Hostinfo{
+			Hostname: "reregister-zero-expiry",
+		},
+		Expiry: time.Time{}, // still zero
+	}
+
+	resp2, err := app.handleRegisterWithAuthKey(regReq2, machineKey.Public())
+	require.NoError(t, err)
+	require.True(t, resp2.MachineAuthorized)
+
+	node2, found := app.state.GetNodeByNodeKey(nodeKey2.Public())
+	require.True(t, found)
+	assert.False(t, node2.Expiry().Valid(),
+		"re-registration with zero client expiry and no default should leave expiry nil, not pointer to zero time")
+}

hscontrol/auth_test.go

@@ -816,10 +816,12 @@ func TestAuthenticationFlows(t *testing.T) {
 			validate: func(t *testing.T, resp *tailcfg.RegisterResponse, app *Headscale) { //nolint:thelper //nolint:thelper
 				assert.True(t, resp.MachineAuthorized)
 
-				// Node should be created with generated hostname
+				// Raw hostname is preserved (empty in, empty stored), and
+				// GivenName falls back to the literal "node" per SaaS.
 				node, found := app.state.GetNodeByNodeKey(nodeKey1.Public())
 				assert.True(t, found)
-				assert.NotEmpty(t, node.Hostname())
+				assert.Empty(t, node.Hostname())
+				assert.Equal(t, "node", node.GivenName())
 			},
 		},
 		// TEST: Nil hostinfo is handled with defensive code
@@ -854,12 +856,12 @@ func TestAuthenticationFlows(t *testing.T) {
 			validate: func(t *testing.T, resp *tailcfg.RegisterResponse, app *Headscale) { //nolint:thelper //nolint:thelper
 				assert.True(t, resp.MachineAuthorized)
 
-				// Node should be created with generated hostname from defensive code
+				// With nil Hostinfo the raw hostname stays empty and GivenName
+				// falls back to the literal "node" per the SaaS spec.
 				node, found := app.state.GetNodeByNodeKey(nodeKey1.Public())
 				assert.True(t, found)
-				assert.NotEmpty(t, node.Hostname())
-				// Hostname should start with "node-" (generated from machine key)
-				assert.True(t, strings.HasPrefix(node.Hostname(), "node-"))
+				assert.Empty(t, node.Hostname())
+				assert.Equal(t, "node", node.GivenName())
 			},
 		},
 
@@ -2251,9 +2253,9 @@ func TestAuthenticationFlows(t *testing.T) {
 				assert.True(t, found, "node should be registered despite nil hostinfo")
 
 				if found {
-					// Should have some default hostname or handle nil gracefully
-					hostname := node.Hostname()
-					assert.NotEmpty(t, hostname, "should have some hostname even with nil hostinfo")
+					// Raw hostname stays empty; GivenName falls back to "node".
+					assert.Empty(t, node.Hostname())
+					assert.Equal(t, "node", node.GivenName())
 				}
 			},
 		},
@@ -3986,3 +3988,116 @@ func TestTaggedNodeWithoutUserToDifferentUser(t *testing.T) {
 		nodeAfterReauth.ID().Uint64(), nodeAfterReauth.Tags().AsSlice(),
 		nodeAfterReauth.IsTagged(), nodeAfterReauth.UserID().Get())
 }
+
+// TestHandleNodeFromPreAuthKey_OldUserNil_NoPanic asserts that
+// HandleNodeFromPreAuthKey does not panic when the in-memory NodeStore
+// holds a non-tagged node whose UserID points at a user but whose User
+// pointer is nil (orphan snapshot, e.g. a Preload("User") join missed
+// the row). Re-registering the same machine key under a different user
+// enters the "different user" branch and would otherwise crash at
+// oldUser.Name() in UserView.Name when the backing pointer is nil.
+func TestHandleNodeFromPreAuthKey_OldUserNil_NoPanic(t *testing.T) {
+	app := createTestApp(t)
+
+	userA := app.state.CreateUserForTest("preauth-orphan-old")
+	userB := app.state.CreateUserForTest("preauth-orphan-new")
+
+	machineKey := key.NewMachine()
+	orphanNodeKey := key.NewNode()
+
+	userIDA := userA.ID
+	orphan := types.Node{
+		ID:             99001,
+		MachineKey:     machineKey.Public(),
+		NodeKey:        orphanNodeKey.Public(),
+		Hostname:       "preauth-orphan",
+		GivenName:      "preauth-orphan",
+		UserID:         &userIDA,
+		User:           nil,
+		RegisterMethod: "authkey",
+	}
+	app.state.PutNodeInStoreForTest(orphan)
+
+	pakB, err := app.state.CreatePreAuthKey(userB.TypedID(), true, false, nil, nil)
+	require.NoError(t, err)
+
+	newNodeKey := key.NewNode()
+	regReq := tailcfg.RegisterRequest{
+		Auth: &tailcfg.RegisterResponseAuth{
+			AuthKey: pakB.Key,
+		},
+		NodeKey: newNodeKey.Public(),
+		Hostinfo: &tailcfg.Hostinfo{
+			Hostname: "preauth-orphan-newuser",
+		},
+		Expiry: time.Now().Add(24 * time.Hour),
+	}
+
+	resp, err := app.handleRegisterWithAuthKey(regReq, machineKey.Public())
+	require.NoError(t, err, "registration must not panic when old user is nil")
+	require.NotNil(t, resp)
+	require.True(t, resp.MachineAuthorized)
+
+	var registered types.NodeView
+
+	require.EventuallyWithT(t, func(c *assert.CollectT) {
+		var found bool
+
+		registered, found = app.state.GetNodeByNodeKey(newNodeKey.Public())
+		assert.True(c, found, "new node should be available in NodeStore")
+	}, 1*time.Second, 50*time.Millisecond, "waiting for new node")
+
+	assert.NotEqual(t, types.NodeID(99001), registered.ID(), "new node, not orphan")
+	assert.Equal(t, userB.ID, registered.UserID().Get(), "new node belongs to userB")
+}
+
+// TestHandleNodeFromAuthPath_OldUserNil_NoPanic is the parallel guard
+// for the gRPC/OIDC entry point. Same orphan shape as
+// TestHandleNodeFromPreAuthKey_OldUserNil_NoPanic; HandleNodeFromAuthPath
+// has its own oldUser.Name() log line in the existingNodeOwnedByOtherUser
+// branch and panics independently of the noise registration path.
+func TestHandleNodeFromAuthPath_OldUserNil_NoPanic(t *testing.T) {
+	app := createTestApp(t)
+
+	userA := app.state.CreateUserForTest("authpath-orphan-old")
+	userB := app.state.CreateUserForTest("authpath-orphan-new")
+
+	machineKey := key.NewMachine()
+	orphanNodeKey := key.NewNode()
+
+	userIDA := userA.ID
+	orphan := types.Node{
+		ID:             99002,
+		MachineKey:     machineKey.Public(),
+		NodeKey:        orphanNodeKey.Public(),
+		Hostname:       "authpath-orphan",
+		GivenName:      "authpath-orphan",
+		UserID:         &userIDA,
+		User:           nil,
+		RegisterMethod: "oidc",
+	}
+	app.state.PutNodeInStoreForTest(orphan)
+
+	newNodeKey := key.NewNode()
+	authID := types.MustAuthID()
+	regEntry := types.NewRegisterAuthRequest(&types.RegistrationData{
+		MachineKey: machineKey.Public(),
+		NodeKey:    newNodeKey.Public(),
+		Hostname:   "authpath-orphan-newuser",
+		Hostinfo: &tailcfg.Hostinfo{
+			Hostname: "authpath-orphan-newuser",
+		},
+	})
+	app.state.SetAuthCacheEntry(authID, regEntry)
+
+	node, _, err := app.state.HandleNodeFromAuthPath(
+		authID,
+		types.UserID(userB.ID),
+		nil,
+		"oidc",
+	)
+	require.NoError(t, err, "auth-path registration must not panic on nil old user")
+	require.True(t, node.Valid())
+	assert.NotEqual(t, types.NodeID(99002), node.ID(), "new node, not orphan")
+	assert.Equal(t, userB.ID, node.UserID().Get(), "new node belongs to userB")
+}

hscontrol/db/ephemeral_garbage_collector_test.go

@@ -379,7 +379,7 @@ func TestEphemeralGarbageCollectorConcurrentScheduleAndClose(t *testing.T) {
 	stopScheduling := make(chan struct{})
 
 	// Track how many nodes have been scheduled
-	var scheduledCount int64
+	var scheduledCount atomic.Int64
 
 	// Launch goroutines that continuously schedule nodes
 	for schedulerIndex := range numSchedulers {
@@ -396,7 +396,7 @@ func TestEphemeralGarbageCollectorConcurrentScheduleAndClose(t *testing.T) {
 				default:
 					nodeID := types.NodeID(baseNodeID + j + 1) //nolint:gosec // safe conversion in test
 					gc.Schedule(nodeID, 1*time.Hour)           // Long expiry to ensure it doesn't trigger during test
-					atomic.AddInt64(&scheduledCount, 1)
+					scheduledCount.Add(1)
 
 					// Yield to other goroutines to introduce variability
 					runtime.Gosched()
@@ -410,7 +410,7 @@ func TestEphemeralGarbageCollectorConcurrentScheduleAndClose(t *testing.T) {
 		defer wg.Done()
 
 		// Wait until enough nodes have been scheduled
-		for atomic.LoadInt64(&scheduledCount) < int64(numSchedulers*closeAfterNodes) {
+		for scheduledCount.Load() < int64(numSchedulers*closeAfterNodes) {
 			runtime.Gosched()
 		}
 

hscontrol/db/node.go

@@ -5,11 +5,9 @@ import (
 	"errors"
 	"fmt"
 	"net/netip"
-	"regexp"
 	"slices"
 	"sort"
 	"strconv"
-	"strings"
 	"sync"
 	"testing"
 	"time"
@@ -21,6 +19,7 @@ import (
 	"gorm.io/gorm"
 	"tailscale.com/net/tsaddr"
 	"tailscale.com/types/key"
+	"tailscale.com/util/dnsname"
 )
 
 const (
@@ -34,8 +33,6 @@ const (
 // ErrNodeNameNotUnique is returned when a node name is not unique.
 var ErrNodeNameNotUnique = errors.New("node name is not unique")
 
-var invalidDNSRegex = regexp.MustCompile("[^a-z0-9-.]+")
-
 var (
 	ErrNodeNotFound                  = errors.New("node not found")
 	ErrNodeRouteIsNotAvailable       = errors.New("route is not available on node")
@@ -291,7 +288,7 @@ func SetLastSeen(tx *gorm.DB, nodeID types.NodeID, lastSeen time.Time) error {
 func RenameNode(tx *gorm.DB,
 	nodeID types.NodeID, newName string,
 ) error {
-	err := util.ValidateHostname(newName)
+	err := dnsname.ValidLabel(newName)
 	if err != nil {
 		return fmt.Errorf("renaming node: %w", err)
 	}
@@ -299,8 +296,7 @@ func RenameNode(tx *gorm.DB,
 	// Check if the new name is unique
 	var count int64
 
-	err = tx.Model(&types.Node{}).Where("given_name = ? AND id != ?", newName, nodeID).Count(&count).Error
-	if err != nil {
+	if err := tx.Model(&types.Node{}).Where("given_name = ? AND id != ?", newName, nodeID).Count(&count).Error; err != nil { //nolint:noinlineerr
 		return fmt.Errorf("checking name uniqueness: %w", err)
 	}
 
@@ -427,22 +423,11 @@ func RegisterNodeForTest(tx *gorm.DB, node types.Node, ipv4 *netip.Addr, ipv6 *n
 	node.IPv4 = ipv4
 	node.IPv6 = ipv6
 
-	var err error
-
-	node.Hostname, err = util.NormaliseHostname(node.Hostname)
-	if err != nil {
-		newHostname := util.InvalidString()
-		log.Info().Err(err).Str(zf.InvalidHostname, node.Hostname).Str(zf.NewHostname, newHostname).Msgf("invalid hostname, replacing")
-		node.Hostname = newHostname
-	}
-
 	if node.GivenName == "" {
-		givenName, err := EnsureUniqueGivenName(tx, node.Hostname)
-		if err != nil {
-			return nil, fmt.Errorf("ensuring unique given name: %w", err)
+		node.GivenName = dnsname.SanitizeHostname(node.Hostname)
+		if node.GivenName == "" {
+			node.GivenName = "node"
 		}
-
-		node.GivenName = givenName
 	}
 
 	if err := tx.Save(&node).Error; err != nil { //nolint:noinlineerr
@@ -484,72 +469,6 @@ func NodeSetMachineKey(
 	}).Error
 }
 
-func generateGivenName(suppliedName string, randomSuffix bool) (string, error) {
-	// Strip invalid DNS characters for givenName
-	suppliedName = strings.ToLower(suppliedName)
-	suppliedName = invalidDNSRegex.ReplaceAllString(suppliedName, "")
-
-	if len(suppliedName) > util.LabelHostnameLength {
-		return "", types.ErrHostnameTooLong
-	}
-
-	if randomSuffix {
-		// Trim if a hostname will be longer than 63 chars after adding the hash.
-		trimmedHostnameLength := util.LabelHostnameLength - NodeGivenNameHashLength - NodeGivenNameTrimSize
-		if len(suppliedName) > trimmedHostnameLength {
-			suppliedName = suppliedName[:trimmedHostnameLength]
-		}
-
-		suffix, err := util.GenerateRandomStringDNSSafe(NodeGivenNameHashLength)
-		if err != nil {
-			return "", err
-		}
-
-		suppliedName += "-" + suffix
-	}
-
-	return suppliedName, nil
-}
-
-func isUniqueName(tx *gorm.DB, name string) (bool, error) {
-	nodes := types.Nodes{}
-
-	err := tx.
-		Where("given_name = ?", name).Find(&nodes).Error
-	if err != nil {
-		return false, err
-	}
-
-	return len(nodes) == 0, nil
-}
-
-// EnsureUniqueGivenName generates a unique given name for a node based on its hostname.
-func EnsureUniqueGivenName(
-	tx *gorm.DB,
-	name string,
-) (string, error) {
-	givenName, err := generateGivenName(name, false)
-	if err != nil {
-		return "", err
-	}
-
-	unique, err := isUniqueName(tx, givenName)
-	if err != nil {
-		return "", err
-	}
-
-	if !unique {
-		postfixedName, err := generateGivenName(name, true)
-		if err != nil {
-			return "", err
-		}
-
-		givenName = postfixedName
-	}
-
-	return givenName, nil
-}
-
 // EphemeralGarbageCollector is a garbage collector that will delete nodes after
 // a certain amount of time.
 // It is used to delete ephemeral nodes that have disconnected and should be

hscontrol/db/node_test.go

@@ -5,7 +5,6 @@ import (
 	"fmt"
 	"math/big"
 	"net/netip"
-	"regexp"
 	"runtime"
 	"sync"
 	"sync/atomic"
@@ -227,122 +226,6 @@ func TestSetTags(t *testing.T) {
 	assert.Equal(t, []string{"tag:bar", "tag:test", "tag:unknown"}, node.Tags)
 }
 
-func TestHeadscale_generateGivenName(t *testing.T) {
-	type args struct {
-		suppliedName string
-		randomSuffix bool
-	}
-
-	tests := []struct {
-		name    string
-		args    args
-		want    *regexp.Regexp
-		wantErr bool
-	}{
-		{
-			name: "simple node name generation",
-			args: args{
-				suppliedName: "testnode",
-				randomSuffix: false,
-			},
-			want:    regexp.MustCompile("^testnode$"),
-			wantErr: false,
-		},
-		{
-			name: "UPPERCASE node name generation",
-			args: args{
-				suppliedName: "TestNode",
-				randomSuffix: false,
-			},
-			want:    regexp.MustCompile("^testnode$"),
-			wantErr: false,
-		},
-		{
-			name: "node name with 53 chars",
-			args: args{
-				suppliedName: "testmaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaachine",
-				randomSuffix: false,
-			},
-			want:    regexp.MustCompile("^testmaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaachine$"),
-			wantErr: false,
-		},
-		{
-			name: "node name with 63 chars",
-			args: args{
-				suppliedName: "nodeeeeeee12345678901234567890123456789012345678901234567890123",
-				randomSuffix: false,
-			},
-			want:    regexp.MustCompile("^nodeeeeeee12345678901234567890123456789012345678901234567890123$"),
-			wantErr: false,
-		},
-		{
-			name: "node name with 64 chars",
-			args: args{
-				suppliedName: "nodeeeeeee123456789012345678901234567890123456789012345678901234",
-				randomSuffix: false,
-			},
-			want:    nil,
-			wantErr: true,
-		},
-		{
-			name: "node name with 73 chars",
-			args: args{
-				suppliedName: "nodeeeeeee123456789012345678901234567890123456789012345678901234567890123",
-				randomSuffix: false,
-			},
-			want:    nil,
-			wantErr: true,
-		},
-		{
-			name: "node name with random suffix",
-			args: args{
-				suppliedName: "test",
-				randomSuffix: true,
-			},
-			want:    regexp.MustCompile(fmt.Sprintf("^test-[a-z0-9]{%d}$", NodeGivenNameHashLength)),
-			wantErr: false,
-		},
-		{
-			name: "node name with 63 chars with random suffix",
-			args: args{
-				suppliedName: "nodeeee12345678901234567890123456789012345678901234567890123",
-				randomSuffix: true,
-			},
-			want:    regexp.MustCompile(fmt.Sprintf("^nodeeee1234567890123456789012345678901234567890123456-[a-z0-9]{%d}$", NodeGivenNameHashLength)),
-			wantErr: false,
-		},
-	}
-	for _, tt := range tests {
-		t.Run(tt.name, func(t *testing.T) {
-			got, err := generateGivenName(tt.args.suppliedName, tt.args.randomSuffix)
-			if (err != nil) != tt.wantErr {
-				t.Errorf(
-					"Headscale.GenerateGivenName() error = %v, wantErr %v",
-					err,
-					tt.wantErr,
-				)
-
-				return
-			}
-
-			if tt.want != nil && !tt.want.MatchString(got) {
-				t.Errorf(
-					"Headscale.GenerateGivenName() = %v, does not match %v",
-					tt.want,
-					got,
-				)
-			}
-
-			if len(got) > util.LabelHostnameLength {
-				t.Errorf(
-					"Headscale.GenerateGivenName() = %v is larger than allowed DNS segment %d",
-					got,
-					util.LabelHostnameLength,
-				)
-			}
-		})
-	}
-}
 
 func TestAutoApproveRoutes(t *testing.T) {
 	tests := []struct {
@@ -633,7 +516,7 @@ func TestEphemeralGarbageCollectorLoads(t *testing.T) {
 
 	want := 1000
 
-	var deletedCount int64
+	var deletedCount atomic.Int64
 
 	e := NewEphemeralGarbageCollector(func(ni types.NodeID) {
 		mu.Lock()
@@ -644,7 +527,7 @@ func TestEphemeralGarbageCollectorLoads(t *testing.T) {
 
 		got = append(got, ni)
 
-		atomic.AddInt64(&deletedCount, 1)
+		deletedCount.Add(1)
 	})
 	go e.Start()
 
@@ -655,7 +538,7 @@ func TestEphemeralGarbageCollectorLoads(t *testing.T) {
 
 	// Wait for all deletions to complete
 	assert.EventuallyWithT(t, func(c *assert.CollectT) {
-		count := atomic.LoadInt64(&deletedCount)
+		count := deletedCount.Load()
 		assert.Equal(c, int64(want), count, "all nodes should be deleted")
 	}, 10*time.Second, 50*time.Millisecond, "waiting for all deletions")
 
@@ -742,281 +625,6 @@ func TestListEphemeralNodes(t *testing.T) {
 	assert.Equal(t, nodeEph.Hostname, ephemeralNodes[0].Hostname)
 }
 
-func TestNodeNaming(t *testing.T) {
-	db, err := newSQLiteTestDB()
-	if err != nil {
-		t.Fatalf("creating db: %s", err)
-	}
-
-	user, err := db.CreateUser(types.User{Name: "test"})
-	require.NoError(t, err)
-
-	user2, err := db.CreateUser(types.User{Name: "user2"})
-	require.NoError(t, err)
-
-	node := types.Node{
-		ID:             0,
-		MachineKey:     key.NewMachine().Public(),
-		NodeKey:        key.NewNode().Public(),
-		Hostname:       "test",
-		UserID:         &user.ID,
-		RegisterMethod: util.RegisterMethodAuthKey,
-		Hostinfo:       &tailcfg.Hostinfo{},
-	}
-
-	node2 := types.Node{
-		ID:             0,
-		MachineKey:     key.NewMachine().Public(),
-		NodeKey:        key.NewNode().Public(),
-		Hostname:       "test",
-		UserID:         &user2.ID,
-		RegisterMethod: util.RegisterMethodAuthKey,
-		Hostinfo:       &tailcfg.Hostinfo{},
-	}
-
-	// Using non-ASCII characters in the hostname can
-	// break your network, so they should be replaced when registering
-	// a node.
-	// https://github.com/juanfont/headscale/issues/2343
-	nodeInvalidHostname := types.Node{
-		MachineKey:     key.NewMachine().Public(),
-		NodeKey:        key.NewNode().Public(),
-		Hostname:       "我的电脑", //nolint:gosmopolitan // intentional i18n test data
-		UserID:         &user2.ID,
-		RegisterMethod: util.RegisterMethodAuthKey,
-	}
-
-	nodeShortHostname := types.Node{
-		MachineKey:     key.NewMachine().Public(),
-		NodeKey:        key.NewNode().Public(),
-		Hostname:       "a",
-		UserID:         &user2.ID,
-		RegisterMethod: util.RegisterMethodAuthKey,
-	}
-
-	err = db.DB.Save(&node).Error
-	require.NoError(t, err)
-
-	err = db.DB.Save(&node2).Error
-	require.NoError(t, err)
-
-	err = db.DB.Transaction(func(tx *gorm.DB) error {
-		_, err := RegisterNodeForTest(tx, node, nil, nil)
-		if err != nil {
-			return err
-		}
-
-		_, err = RegisterNodeForTest(tx, node2, nil, nil)
-		if err != nil {
-			return err
-		}
-
-		_, _ = RegisterNodeForTest(tx, nodeInvalidHostname, new(mpp("100.64.0.66/32").Addr()), nil)
-		_, err = RegisterNodeForTest(tx, nodeShortHostname, new(mpp("100.64.0.67/32").Addr()), nil)
-
-		return err
-	})
-	require.NoError(t, err)
-
-	nodes, err := db.ListNodes()
-	require.NoError(t, err)
-
-	assert.Len(t, nodes, 4)
-
-	t.Logf("node1 %s %s", nodes[0].Hostname, nodes[0].GivenName)
-	t.Logf("node2 %s %s", nodes[1].Hostname, nodes[1].GivenName)
-	t.Logf("node3 %s %s", nodes[2].Hostname, nodes[2].GivenName)
-	t.Logf("node4 %s %s", nodes[3].Hostname, nodes[3].GivenName)
-
-	assert.Equal(t, nodes[0].Hostname, nodes[0].GivenName)
-	assert.NotEqual(t, nodes[1].Hostname, nodes[1].GivenName)
-	assert.Equal(t, nodes[0].Hostname, nodes[1].Hostname)
-	assert.NotEqual(t, nodes[0].Hostname, nodes[1].GivenName)
-	assert.Contains(t, nodes[1].GivenName, nodes[0].Hostname)
-	assert.Equal(t, nodes[0].GivenName, nodes[1].Hostname)
-	assert.Len(t, nodes[0].Hostname, 4)
-	assert.Len(t, nodes[1].Hostname, 4)
-	assert.Len(t, nodes[0].GivenName, 4)
-	assert.Len(t, nodes[1].GivenName, 13)
-	assert.Contains(t, nodes[2].Hostname, "invalid-") // invalid chars
-	assert.Contains(t, nodes[2].GivenName, "invalid-")
-	assert.Contains(t, nodes[3].Hostname, "invalid-") // too short
-	assert.Contains(t, nodes[3].GivenName, "invalid-")
-
-	// Nodes can be renamed to a unique name
-	err = db.Write(func(tx *gorm.DB) error {
-		return RenameNode(tx, nodes[0].ID, "newname")
-	})
-	require.NoError(t, err)
-
-	nodes, err = db.ListNodes()
-	require.NoError(t, err)
-	assert.Len(t, nodes, 4)
-	assert.Equal(t, "test", nodes[0].Hostname)
-	assert.Equal(t, "newname", nodes[0].GivenName)
-
-	// Nodes can reuse name that is no longer used
-	err = db.Write(func(tx *gorm.DB) error {
-		return RenameNode(tx, nodes[1].ID, "test")
-	})
-	require.NoError(t, err)
-
-	nodes, err = db.ListNodes()
-	require.NoError(t, err)
-	assert.Len(t, nodes, 4)
-	assert.Equal(t, "test", nodes[0].Hostname)
-	assert.Equal(t, "newname", nodes[0].GivenName)
-	assert.Equal(t, "test", nodes[1].GivenName)
-
-	// Nodes cannot be renamed to used names
-	err = db.Write(func(tx *gorm.DB) error {
-		return RenameNode(tx, nodes[0].ID, "test")
-	})
-	require.ErrorContains(t, err, "name is not unique")
-
-	// Rename invalid chars
-	err = db.Write(func(tx *gorm.DB) error {
-		return RenameNode(tx, nodes[2].ID, "我的电脑") //nolint:gosmopolitan // intentional i18n test data
-	})
-	require.ErrorContains(t, err, "invalid characters")
-
-	// Rename too short
-	err = db.Write(func(tx *gorm.DB) error {
-		return RenameNode(tx, nodes[3].ID, "a")
-	})
-	require.ErrorContains(t, err, "at least 2 characters")
-
-	// Rename with emoji
-	err = db.Write(func(tx *gorm.DB) error {
-		return RenameNode(tx, nodes[0].ID, "hostname-with-💩")
-	})
-	require.ErrorContains(t, err, "invalid characters")
-
-	// Rename with only emoji
-	err = db.Write(func(tx *gorm.DB) error {
-		return RenameNode(tx, nodes[0].ID, "🚀")
-	})
-	assert.ErrorContains(t, err, "invalid characters")
-}
-
-func TestRenameNodeComprehensive(t *testing.T) {
-	db, err := newSQLiteTestDB()
-	if err != nil {
-		t.Fatalf("creating db: %s", err)
-	}
-
-	user, err := db.CreateUser(types.User{Name: "test"})
-	require.NoError(t, err)
-
-	node := types.Node{
-		ID:             0,
-		MachineKey:     key.NewMachine().Public(),
-		NodeKey:        key.NewNode().Public(),
-		Hostname:       "testnode",
-		UserID:         &user.ID,
-		RegisterMethod: util.RegisterMethodAuthKey,
-		Hostinfo:       &tailcfg.Hostinfo{},
-	}
-
-	err = db.DB.Save(&node).Error
-	require.NoError(t, err)
-
-	err = db.DB.Transaction(func(tx *gorm.DB) error {
-		_, err := RegisterNodeForTest(tx, node, nil, nil)
-		return err
-	})
-	require.NoError(t, err)
-
-	nodes, err := db.ListNodes()
-	require.NoError(t, err)
-	assert.Len(t, nodes, 1)
-
-	tests := []struct {
-		name    string
-		newName string
-		wantErr string
-	}{
-		{
-			name:    "uppercase_rejected",
-			newName: "User2-Host",
-			wantErr: "must be lowercase",
-		},
-		{
-			name:    "underscore_rejected",
-			newName: "test_node",
-			wantErr: "invalid characters",
-		},
-		{
-			name:    "at_sign_uppercase_rejected",
-			newName: "Test@Host",
-			wantErr: "must be lowercase",
-		},
-		{
-			name:    "at_sign_rejected",
-			newName: "test@host",
-			wantErr: "invalid characters",
-		},
-		{
-			name:    "chinese_chars_with_dash_rejected",
-			newName: "server-北京-01", //nolint:gosmopolitan // intentional i18n test data
-			wantErr: "invalid characters",
-		},
-		{
-			name:    "chinese_only_rejected",
-			newName: "我的电脑", //nolint:gosmopolitan // intentional i18n test data
-			wantErr: "invalid characters",
-		},
-		{
-			name:    "emoji_with_text_rejected",
-			newName: "laptop-🚀",
-			wantErr: "invalid characters",
-		},
-		{
-			name:    "mixed_chinese_emoji_rejected",
-			newName: "测试💻机器", //nolint:gosmopolitan // intentional i18n test data
-			wantErr: "invalid characters",
-		},
-		{
-			name:    "only_emojis_rejected",
-			newName: "🎉🎊",
-			wantErr: "invalid characters",
-		},
-		{
-			name:    "only_at_signs_rejected",
-			newName: "@@@",
-			wantErr: "invalid characters",
-		},
-		{
-			name:    "starts_with_dash_rejected",
-			newName: "-test",
-			wantErr: "cannot start or end with a hyphen",
-		},
-		{
-			name:    "ends_with_dash_rejected",
-			newName: "test-",
-			wantErr: "cannot start or end with a hyphen",
-		},
-		{
-			name:    "too_long_hostname_rejected",
-			newName: "this-is-a-very-long-hostname-that-exceeds-sixty-three-characters-limit",
-			wantErr: "must not exceed 63 characters",
-		},
-		{
-			name:    "too_short_hostname_rejected",
-			newName: "a",
-			wantErr: "at least 2 characters",
-		},
-	}
-
-	for _, tt := range tests {
-		t.Run(tt.name, func(t *testing.T) {
-			err := db.Write(func(tx *gorm.DB) error {
-				return RenameNode(tx, nodes[0].ID, tt.newName)
-			})
-			assert.ErrorContains(t, err, tt.wantErr)
-		})
-	}
-}
 
 func TestListPeers(t *testing.T) {
 	// Setup test database

hscontrol/db/users.go

@@ -28,7 +28,7 @@ func (hsdb *HSDatabase) CreateUser(user types.User) (*types.User, error) {
 // CreateUser creates a new User. Returns error if could not be created
 // or another user already exists.
 func CreateUser(tx *gorm.DB, user types.User) (*types.User, error) {
-	err := util.ValidateHostname(user.Name)
+	err := util.ValidateUsername(user.Name)
 	if err != nil {
 		return nil, err
 	}
@@ -102,7 +102,7 @@ func RenameUser(tx *gorm.DB, uid types.UserID, newName string) error {
 		return err
 	}
 
-	if err = util.ValidateHostname(newName); err != nil { //nolint:noinlineerr
+	if err = util.ValidateUsername(newName); err != nil { //nolint:noinlineerr
 		return err
 	}
 

hscontrol/db/users_test.go

@@ -100,7 +100,7 @@ func TestDestroyUserErrors(t *testing.T) {
 				user, err := db.CreateUser(types.User{Name: "test"})
 				require.NoError(t, err)
 
-				// Create a tagged node with no user_id (the invariant).
+				// Create a tagged node with no user_id (the rule for tagged nodes).
 				node := types.Node{
 					ID:             0,
 					Hostname:       "tagged-node",

hscontrol/debug.go

@@ -1,16 +1,21 @@
 package hscontrol
 
 import (
+	"context"
 	"encoding/json"
 	"fmt"
 	"net"
 	"net/http"
 	"net/netip"
 	"strings"
+	"time"
 
 	"github.com/arl/statsviz"
+	"github.com/juanfont/headscale/hscontrol/templates"
 	"github.com/juanfont/headscale/hscontrol/types"
+	"github.com/juanfont/headscale/hscontrol/types/change"
 	"github.com/prometheus/client_golang/prometheus/promhttp"
+	"tailscale.com/tailcfg"
 	"tailscale.com/tsweb"
 )
 
@@ -324,6 +329,41 @@ func (h *Headscale) debugHTTPServer() *http.Server {
 		}
 	}))
 
+	// Ping endpoint: sends a PingRequest to a node and waits for it to respond.
+	// Supports POST (form submit) and GET with ?node= (clickable quick-ping links).
+	debug.Handle("ping", "Ping a node to check connectivity", http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		var (
+			query  string
+			result *templates.PingResult
+		)
+
+		switch r.Method {
+		case http.MethodPost:
+			r.Body = http.MaxBytesReader(w, r.Body, 4096) //nolint:mnd
+
+			err := r.ParseForm()
+			if err != nil {
+				http.Error(w, "bad form data", http.StatusBadRequest)
+				return
+			}
+
+			query = r.FormValue("node")
+			result = h.doPing(r.Context(), query)
+		case http.MethodGet:
+			// Support ?node= for auto-ping links from other debug pages.
+			if q := r.URL.Query().Get("node"); q != "" {
+				query = q
+				result = h.doPing(r.Context(), query)
+			}
+		}
+
+		nodes := h.connectedNodesList()
+
+		w.Header().Set("Content-Type", "text/html; charset=utf-8")
+		w.WriteHeader(http.StatusOK)
+		_, _ = w.Write([]byte(templates.PingPage(query, result, nodes).Render()))
+	}))
+
 	// statsviz.Register would mount handlers directly on the raw mux,
 	// bypassing the access gate. Build the server by hand and wrap
 	// each handler with protectedDebugHandler.
@@ -339,7 +379,7 @@ func (h *Headscale) debugHTTPServer() *http.Server {
 
 	debugHTTPServer := &http.Server{
 		Addr:         h.cfg.MetricsAddr,
-		Handler:      debugMux,
+		Handler:      securityHeaders(debugMux),
 		ReadTimeout:  types.HTTPTimeout,
 		WriteTimeout: 0,
 	}
@@ -395,13 +435,13 @@ func (h *Headscale) debugBatcher() string {
 		}
 
 		if node.activeConnections > 0 {
-			sb.WriteString(fmt.Sprintf("Node %d:\t%s (%d connections)\n", node.id, status, node.activeConnections))
+			fmt.Fprintf(&sb, "Node %d:\t%s (%d connections)\n", node.id, status, node.activeConnections)
 		} else {
-			sb.WriteString(fmt.Sprintf("Node %d:\t%s\n", node.id, status))
+			fmt.Fprintf(&sb, "Node %d:\t%s\n", node.id, status)
 		}
 	}
 
-	sb.WriteString(fmt.Sprintf("\nSummary: %d connected, %d total\n", connectedCount, totalNodes))
+	fmt.Fprintf(&sb, "\nSummary: %d connected, %d total\n", connectedCount, totalNodes)
 
 	return sb.String()
 }
@@ -436,3 +476,97 @@ func (h *Headscale) debugBatcherJSON() DebugBatcherInfo {
 
 	return info
 }
+
+// connectedNodesList returns a list of connected nodes for the ping page.
+func (h *Headscale) connectedNodesList() []templates.ConnectedNode {
+	debugInfo := h.mapBatcher.Debug()
+
+	var nodes []templates.ConnectedNode
+
+	for nodeID, info := range debugInfo {
+		if !info.Connected {
+			continue
+		}
+
+		nv, ok := h.state.GetNodeByID(nodeID)
+		if !ok {
+			continue
+		}
+
+		cn := templates.ConnectedNode{
+			ID:       nodeID,
+			Hostname: nv.Hostname(),
+		}
+
+		for _, ip := range nv.IPs() {
+			cn.IPs = append(cn.IPs, ip.String())
+		}
+
+		nodes = append(nodes, cn)
+	}
+
+	return nodes
+}
+
+const pingTimeout = 30 * time.Second
+
+// doPing sends a PingRequest to the node identified by query and waits for a response.
+func (h *Headscale) doPing(ctx context.Context, query string) *templates.PingResult {
+	if query == "" {
+		return &templates.PingResult{
+			Status:  "error",
+			Message: "No node specified.",
+		}
+	}
+
+	node, ok := h.state.ResolveNode(query)
+	if !ok {
+		return &templates.PingResult{
+			Status:  "error",
+			Message: fmt.Sprintf("Node %q not found.", query),
+		}
+	}
+
+	nodeID := node.ID()
+
+	if !h.mapBatcher.IsConnected(nodeID) {
+		return &templates.PingResult{
+			Status:  "error",
+			NodeID:  nodeID,
+			Message: fmt.Sprintf("Node %d is not connected.", nodeID),
+		}
+	}
+
+	pingID, responseCh := h.state.RegisterPing(nodeID)
+	defer h.state.CancelPing(pingID)
+
+	// The callback hits /machine/ping-response on the main TLS router,
+	// not the noise chain, so URLIsNoise stays false. Operators running
+	// server_url over plain HTTP are on their own — don't do that.
+	callbackURL := h.cfg.ServerURL + "/machine/ping-response?id=" + pingID
+	h.Change(change.PingNode(nodeID, &tailcfg.PingRequest{
+		URL: callbackURL,
+		Log: true,
+	}))
+
+	select {
+	case latency := <-responseCh:
+		return &templates.PingResult{
+			Status:  "ok",
+			Latency: latency,
+			NodeID:  nodeID,
+		}
+	case <-time.After(pingTimeout):
+		return &templates.PingResult{
+			Status:  "timeout",
+			NodeID:  nodeID,
+			Message: fmt.Sprintf("No response after %s.", pingTimeout),
+		}
+	case <-ctx.Done():
+		return &templates.PingResult{
+			Status:  "error",
+			NodeID:  nodeID,
+			Message: "Request cancelled.",
+		}
+	}
+}

hscontrol/grpcv1.go

@@ -26,6 +26,7 @@ import (
 	"tailscale.com/types/views"
 
 	v1 "github.com/juanfont/headscale/gen/go/headscale/v1"
+	policyv2 "github.com/juanfont/headscale/hscontrol/policy/v2"
 	"github.com/juanfont/headscale/hscontrol/state"
 	"github.com/juanfont/headscale/hscontrol/types"
 	"github.com/juanfont/headscale/hscontrol/util"
@@ -781,6 +782,35 @@ func (api headscaleV1APIServer) SetPolicy(
 	return response, nil
 }
 
+// CheckPolicy validates the given policy against the server's live users
+// and nodes, running its `tests` block as a sandbox. Nothing is persisted
+// and the live PolicyManager is not touched. Works regardless of
+// policy.mode so operators can validate a policy file before storing it.
+func (api headscaleV1APIServer) CheckPolicy(
+	_ context.Context,
+	request *v1.CheckPolicyRequest,
+) (*v1.CheckPolicyResponse, error) {
+	polB := []byte(request.GetPolicy())
+
+	users, err := api.h.state.ListAllUsers()
+	if err != nil {
+		return nil, status.Errorf(codes.Internal, "loading users: %s", err)
+	}
+
+	nodes := api.h.state.ListNodes()
+
+	pm, err := policyv2.NewPolicyManager(polB, users, nodes)
+	if err != nil {
+		return nil, status.Error(codes.InvalidArgument, err.Error())
+	}
+
+	if _, err := pm.SetPolicy(polB); err != nil {
+		return nil, status.Error(codes.InvalidArgument, err.Error())
+	}
+
+	return &v1.CheckPolicyResponse{}, nil
+}
+
 // The following service calls are for testing and debugging
 func (api headscaleV1APIServer) DebugCreateNode(
 	ctx context.Context,

hscontrol/grpcv1_test.go

@@ -596,7 +596,7 @@ func TestDeleteUser_TaggedNodeSurvives(t *testing.T) {
 	require.NoError(t, err)
 	require.True(t, resp.MachineAuthorized)
 
-	// Verify the registered node has nil UserID (enforced invariant).
+	// Verify the registered node has nil UserID (enforced at registration).
 	node, found := app.state.GetNodeByNodeKey(nodeKey.Public())
 	require.True(t, found)
 	require.True(t, node.IsTagged())

hscontrol/handlers.go

@@ -44,6 +44,54 @@ func httpError(w http.ResponseWriter, err error) {
 	}
 }
 
+// httpUserError logs an error and sends a styled HTML error page.
+// Use this for browser-facing error paths (OIDC, registration confirm)
+// where the user should see a branded page instead of plain text.
+// Technical details go to the server log; the HTML page only shows
+// an actionable message derived from the HTTP status code.
+func httpUserError(w http.ResponseWriter, err error) {
+	code := http.StatusInternalServerError
+
+	if herr, ok := errors.AsType[HTTPError](err); ok {
+		if herr.Code != 0 {
+			code = herr.Code
+		}
+
+		log.Error().Err(herr.Err).Int("code", code).Msgf("user msg: %s", herr.Msg)
+	} else {
+		log.Error().Err(err).Int("code", code).Msg("http internal server error")
+	}
+
+	userMsg := userMessageForStatusCode(code)
+
+	w.Header().Set("Content-Type", "text/html; charset=utf-8")
+	w.WriteHeader(code)
+
+	page := templates.AuthError(templates.AuthErrorResult{
+		Title:   "Headscale - Error",
+		Heading: http.StatusText(code),
+		Message: userMsg,
+	})
+
+	_, werr := w.Write([]byte(page.Render()))
+	if werr != nil {
+		log.Error().Err(werr).Msg("failed to write HTML error response")
+	}
+}
+
+func userMessageForStatusCode(code int) string {
+	switch {
+	case code == http.StatusUnauthorized || code == http.StatusForbidden:
+		return "You are not authorized. Please contact your administrator."
+	case code == http.StatusGone:
+		return "Your session has expired. Please try again."
+	case code >= 400 && code < 500:
+		return "The request could not be processed. Please try again."
+	default:
+		return "Something went wrong. Please try again later."
+	}
+}
+
 // HTTPError represents an error that is surfaced to the user via web.
 type HTTPError struct {
 	Code int    // HTTP response code to send to client; 0 means 500

hscontrol/handlers_test.go

@@ -12,6 +12,8 @@ import (
 	"github.com/stretchr/testify/assert"
 )
 
+var errTestUnexpected = errors.New("unexpected failure")
+
 // TestHandleVerifyRequest_OversizedBodyRejected verifies that the
 // /verify handler refuses POST bodies larger than verifyBodyLimit.
 // The MaxBytesReader is applied in VerifyHandler, so we simulate
@@ -55,3 +57,73 @@ func errorAsHTTPError(err error) (HTTPError, bool) {
 
 	return HTTPError{}, false
 }
+
+func TestHttpUserError(t *testing.T) {
+	t.Parallel()
+
+	tests := []struct {
+		name           string
+		err            error
+		wantCode       int
+		wantContains   string
+		wantNotContain string
+	}{
+		{
+			name:           "forbidden_renders_authorization_message",
+			err:            NewHTTPError(http.StatusForbidden, "csrf token mismatch", nil),
+			wantCode:       http.StatusForbidden,
+			wantContains:   "You are not authorized. Please contact your administrator.",
+			wantNotContain: "csrf token mismatch",
+		},
+		{
+			name:           "unauthorized_renders_authorization_message",
+			err:            NewHTTPError(http.StatusUnauthorized, "unauthorised domain", nil),
+			wantCode:       http.StatusUnauthorized,
+			wantContains:   "You are not authorized. Please contact your administrator.",
+			wantNotContain: "unauthorised domain",
+		},
+		{
+			name:           "gone_renders_session_expired",
+			err:            NewHTTPError(http.StatusGone, "login session expired, try again", nil),
+			wantCode:       http.StatusGone,
+			wantContains:   "Your session has expired. Please try again.",
+			wantNotContain: "login session expired",
+		},
+		{
+			name:           "bad_request_renders_generic_retry",
+			err:            NewHTTPError(http.StatusBadRequest, "state not found", nil),
+			wantCode:       http.StatusBadRequest,
+			wantContains:   "The request could not be processed. Please try again.",
+			wantNotContain: "state not found",
+		},
+		{
+			name:         "plain_error_renders_500",
+			err:          errTestUnexpected,
+			wantCode:     http.StatusInternalServerError,
+			wantContains: "Something went wrong. Please try again later.",
+		},
+		{
+			name:         "html_structure_present",
+			err:          NewHTTPError(http.StatusGone, "session expired", nil),
+			wantCode:     http.StatusGone,
+			wantContains: "<!DOCTYPE html>",
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			t.Parallel()
+
+			rec := httptest.NewRecorder()
+			httpUserError(rec, tt.err)
+
+			assert.Equal(t, tt.wantCode, rec.Code)
+			assert.Contains(t, rec.Header().Get("Content-Type"), "text/html")
+			assert.Contains(t, rec.Body.String(), tt.wantContains)
+
+			if tt.wantNotContain != "" {
+				assert.NotContains(t, rec.Body.String(), tt.wantNotContain)
+			}
+		})
+	}
+}

hscontrol/mapper/batcher_concurrency_test.go

@@ -782,6 +782,7 @@ func TestBug3_CleanupOfflineNodes_TOCTOU(t *testing.T) {
 	entry.lastUsed.Store(time.Now().Unix())
 	mc.addConnection(entry)
 	mc.markConnected()
+
 	lb.channels[targetNode] = newCh
 
 	// Now run cleanup. Node 3 is in the candidates list (old disconnect

hscontrol/mapper/batcher_test.go

@@ -16,7 +16,6 @@ import (
 	"github.com/juanfont/headscale/hscontrol/state"
 	"github.com/juanfont/headscale/hscontrol/types"
 	"github.com/juanfont/headscale/hscontrol/types/change"
-	"github.com/rs/zerolog"
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 	"tailscale.com/tailcfg"
@@ -141,9 +140,9 @@ type node struct {
 	ch chan *tailcfg.MapResponse
 
 	// Update tracking (all accessed atomically for thread safety)
-	updateCount   int64
-	patchCount    int64
-	fullCount     int64
+	updateCount   atomic.Int64
+	patchCount    atomic.Int64
+	fullCount     atomic.Int64
 	maxPeersCount atomic.Int64
 	lastPeerCount atomic.Int64
 	stop          chan struct{}
@@ -404,14 +403,14 @@ func (n *node) start() {
 		for {
 			select {
 			case data := <-n.ch:
-				atomic.AddInt64(&n.updateCount, 1)
+				n.updateCount.Add(1)
 
 				// Parse update and track detailed stats
 				info := parseUpdateAndAnalyze(data)
 				{
 					// Track update types
 					if info.IsFull {
-						atomic.AddInt64(&n.fullCount, 1)
+						n.fullCount.Add(1)
 						n.lastPeerCount.Store(int64(info.PeerCount))
 						// Update max peers seen using compare-and-swap for thread safety
 						for {
@@ -427,7 +426,7 @@ func (n *node) start() {
 					}
 
 					if info.IsPatch {
-						atomic.AddInt64(&n.patchCount, 1)
+						n.patchCount.Add(1)
 						// For patches, we track how many patch items using compare-and-swap
 						for {
 							current := n.maxPeersCount.Load()
@@ -466,9 +465,9 @@ func (n *node) cleanup() NodeStats {
 	}
 
 	return NodeStats{
-		TotalUpdates:  atomic.LoadInt64(&n.updateCount),
-		PatchUpdates:  atomic.LoadInt64(&n.patchCount),
-		FullUpdates:   atomic.LoadInt64(&n.fullCount),
+		TotalUpdates:  n.updateCount.Load(),
+		PatchUpdates:  n.patchCount.Load(),
+		FullUpdates:   n.fullCount.Load(),
 		MaxPeersSeen:  int(n.maxPeersCount.Load()),
 		LastPeerCount: int(n.lastPeerCount.Load()),
 	}
@@ -509,7 +508,7 @@ func TestEnhancedNodeTracking(t *testing.T) {
 
 	// Wait for tracking goroutine to process the update
 	assert.EventuallyWithT(t, func(c *assert.CollectT) {
-		assert.GreaterOrEqual(c, atomic.LoadInt64(&testNode.updateCount), int64(1), "should have processed the update")
+		assert.GreaterOrEqual(c, testNode.updateCount.Load(), int64(1), "should have processed the update")
 	}, time.Second, 10*time.Millisecond, "waiting for update to be processed")
 
 	// Check stats
@@ -553,7 +552,7 @@ func TestEnhancedTrackingWithBatcher(t *testing.T) {
 
 			// Wait for updates to be processed (at least 1 update received)
 			assert.EventuallyWithT(t, func(c *assert.CollectT) {
-				assert.GreaterOrEqual(c, atomic.LoadInt64(&testNode.updateCount), int64(1), "should have received updates")
+				assert.GreaterOrEqual(c, testNode.updateCount.Load(), int64(1), "should have received updates")
 			}, time.Second, 10*time.Millisecond, "waiting for updates to be processed")
 
 			// Check stats
@@ -574,12 +573,6 @@ func TestEnhancedTrackingWithBatcher(t *testing.T) {
 // and ensure all nodes can see all other nodes. This is a critical test for mesh network
 // functionality where every node must be able to communicate with every other node.
 func TestBatcherScalabilityAllToAll(t *testing.T) {
-	// Reduce verbose application logging for cleaner test output
-	originalLevel := zerolog.GlobalLevel()
-	defer zerolog.SetGlobalLevel(originalLevel)
-
-	zerolog.SetGlobalLevel(zerolog.ErrorLevel)
-
 	// Test cases: different node counts to stress test the all-to-all connectivity
 	testCases := []struct {
 		name      string
@@ -2141,8 +2134,8 @@ func TestNodeDeletedWhileChangesPending(t *testing.T) {
 
 			assert.EventuallyWithT(t, func(c *assert.CollectT) {
 				// Node 1 and 2 should receive updates
-				stats1 := NodeStats{TotalUpdates: atomic.LoadInt64(&node1.updateCount)}
-				stats2 := NodeStats{TotalUpdates: atomic.LoadInt64(&node2.updateCount)}
+				stats1 := NodeStats{TotalUpdates: node1.updateCount.Load()}
+				stats2 := NodeStats{TotalUpdates: node2.updateCount.Load()}
 				assert.Positive(c, stats1.TotalUpdates, "node1 should have received updates")
 				assert.Positive(c, stats2.TotalUpdates, "node2 should have received updates")
 			}, 5*time.Second, 100*time.Millisecond, "waiting for remaining nodes to receive updates")

hscontrol/mapper/builder.go

@@ -277,6 +277,12 @@ func (b *MapResponseBuilder) buildTailPeers(peers views.Slice[types.NodeView]) (
 	return tailPeers, nil
 }
 
+// WithPingRequest adds a PingRequest to the response.
+func (b *MapResponseBuilder) WithPingRequest(pr *tailcfg.PingRequest) *MapResponseBuilder {
+	b.resp.PingRequest = pr
+	return b
+}
+
 // WithPeerChangedPatch adds peer change patches.
 func (b *MapResponseBuilder) WithPeerChangedPatch(changes []*tailcfg.PeerChange) *MapResponseBuilder {
 	b.resp.PeersChangedPatch = changes

hscontrol/mapper/mapper.go

@@ -308,6 +308,10 @@ func (m *mapper) buildFromChange(
 		builder.WithPeerChangedPatch(resp.PeerPatches)
 	}
 
+	if resp.PingRequest != nil {
+		builder.WithPingRequest(resp.PingRequest)
+	}
+
 	return builder.Build()
 }
 

hscontrol/mapper/tail_test.go

@@ -9,7 +9,6 @@ import (
 
 	"github.com/google/go-cmp/cmp"
 	"github.com/google/go-cmp/cmp/cmpopts"
-	"github.com/juanfont/headscale/hscontrol/routes"
 	"github.com/juanfont/headscale/hscontrol/types"
 	"tailscale.com/net/tsaddr"
 	"tailscale.com/tailcfg"
@@ -209,25 +208,30 @@ func TestTailNode(t *testing.T) {
 
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
-			primary := routes.New()
 			cfg := &types.Config{
 				BaseDomain:          tt.baseDomain,
 				TailcfgDNSConfig:    tt.dnsConfig,
 				RandomizeClientPort: false,
 				Taildrop:            types.TaildropConfig{Enabled: true},
 			}
-			_ = primary.SetRoutes(tt.node.ID, tt.node.SubnetRoutes()...)
 
-			// This is a hack to avoid having a second node to test the primary route.
-			// This should be baked into the test case proper if it is extended in the future.
-			_ = primary.SetRoutes(2, netip.MustParsePrefix("192.168.0.0/24"))
+			// Stub primary-route lookup: tt.node owns its SubnetRoutes,
+			// node ID 2 owns 192.168.0.0/24 (a hack carried over from
+			// the original routes-package-driven version of this test —
+			// avoids spinning up a second node just to validate that
+			// other nodes' primaries don't leak into tt.node's TailNode
+			// output).
+			primaries := map[types.NodeID][]netip.Prefix{
+				tt.node.ID: tt.node.SubnetRoutes(),
+				2:          {netip.MustParsePrefix("192.168.0.0/24")},
+			}
 			nv := tt.node.View()
 			got, err := nv.TailNode(
 				0,
 				func(id types.NodeID) []netip.Prefix {
 					// Route function returns primaries + exit routes
 					// (matching the real caller contract).
-					return slices.Concat(primary.PrimaryRoutes(id), nv.ExitRoutes())
+					return slices.Concat(primaries[id], nv.ExitRoutes())
 				},
 				cfg,
 			)

hscontrol/noise.go

@@ -169,7 +169,7 @@ func (h *Headscale) NoiseUpgradeHandler(
 		r.Post("/map", ns.PollNetMapHandler)
 
 		// SSH Check mode endpoint, consulted to validate if a given SSH connection should be accepted or rejected.
-		r.Get("/ssh/action/from/{src_node_id}/to/{dst_node_id}", ns.SSHActionHandler)
+		r.Get("/ssh/action/{src_node_id}/to/{dst_node_id}", ns.SSHActionHandler)
 
 		// Not implemented yet
 		//
@@ -295,6 +295,31 @@ func (ns *noiseServer) NotImplementedHandler(writer http.ResponseWriter, req *ht
 	http.Error(writer, "Not implemented yet", http.StatusNotImplemented)
 }
 
+// PingResponseHandler handles HEAD requests from clients responding to a
+// PingRequest. The client calls this endpoint to prove connectivity.
+// The unguessable ping ID serves as authentication.
+func (h *Headscale) PingResponseHandler(
+	writer http.ResponseWriter,
+	req *http.Request,
+) {
+	if req.Method != http.MethodHead {
+		http.Error(writer, "method not allowed", http.StatusMethodNotAllowed)
+		return
+	}
+
+	pingID := req.URL.Query().Get("id")
+	if pingID == "" {
+		http.Error(writer, "missing ping ID", http.StatusBadRequest)
+		return
+	}
+
+	if h.state.CompletePing(pingID) {
+		writer.WriteHeader(http.StatusOK)
+	} else {
+		http.Error(writer, "unknown or expired ping", http.StatusNotFound)
+	}
+}
+
 func urlParam[T any](req *http.Request, key string) (T, error) {
 	var zero T
 
@@ -394,7 +419,6 @@ func (ns *noiseServer) SSHActionHandler(
 	reqLog := log.With().
 		Uint64("src_node_id", srcNodeID.Uint64()).
 		Uint64("dst_node_id", dstNodeID.Uint64()).
-		Str("ssh_user", req.URL.Query().Get("ssh_user")).
 		Str("local_user", req.URL.Query().Get("local_user")).
 		Logger()
 
@@ -495,8 +519,8 @@ func (ns *noiseServer) sshActionHoldAndDelegate(
 ) (*tailcfg.SSHAction, error) {
 	holdURL, err := url.Parse(
 		ns.headscale.cfg.ServerURL +
-			"/machine/ssh/action/from/$SRC_NODE_ID/to/$DST_NODE_ID" +
-			"?ssh_user=$SSH_USER&local_user=$LOCAL_USER",
+			"/machine/ssh/action/$SRC_NODE_ID/to/$DST_NODE_ID" +
+			"?local_user=$LOCAL_USER",
 	)
 	if err != nil {
 		return nil, NewHTTPError(

hscontrol/noise_test.go

@@ -198,13 +198,50 @@ func TestRegistrationHandler_OversizedBody(t *testing.T) {
 	assert.Equal(t, http.StatusBadRequest, rec.Code)
 }
 
+// TestSSHActionRoute_OldPathReturns404 pins the wire-format shape of the
+// SSH check-action endpoint. Pre-alignment headscale served
+// /machine/ssh/action/from/{src}/to/{dst}?ssh_user=...; the current
+// endpoint is /machine/ssh/action/{src}/to/{dst}?local_user=.... If
+// someone re-adds the old route shape, this fails.
+func TestSSHActionRoute_OldPathReturns404(t *testing.T) {
+	t.Parallel()
+
+	r := chi.NewRouter()
+	r.Route("/machine", func(r chi.Router) {
+		r.Get("/ssh/action/{src_node_id}/to/{dst_node_id}", func(w http.ResponseWriter, _ *http.Request) {
+			w.WriteHeader(http.StatusOK)
+		})
+	})
+
+	cases := []struct {
+		name string
+		path string
+		want int
+	}{
+		{"new", "/machine/ssh/action/1/to/2", http.StatusOK},
+		{"old-with-from", "/machine/ssh/action/from/1/to/2", http.StatusNotFound},
+	}
+
+	for _, tc := range cases {
+		t.Run(tc.name, func(t *testing.T) {
+			t.Parallel()
+
+			req := httptest.NewRequestWithContext(context.Background(), http.MethodGet, tc.path, nil)
+			rec := httptest.NewRecorder()
+			r.ServeHTTP(rec, req)
+
+			assert.Equal(t, tc.want, rec.Code)
+		})
+	}
+}
+
 // newSSHActionRequest builds an httptest request with the chi URL params
 // SSHActionHandler reads (src_node_id and dst_node_id), so the handler
 // can be exercised directly without going through the chi router.
 func newSSHActionRequest(t *testing.T, src, dst types.NodeID) *http.Request {
 	t.Helper()
 
-	url := fmt.Sprintf("/machine/ssh/action/from/%d/to/%d", src.Uint64(), dst.Uint64())
+	url := fmt.Sprintf("/machine/ssh/action/%d/to/%d", src.Uint64(), dst.Uint64())
 	req := httptest.NewRequestWithContext(context.Background(), http.MethodGet, url, nil)
 
 	rctx := chi.NewRouteContext()
@@ -315,7 +352,7 @@ func TestSSHActionFollowUp_RejectsBindingMismatch(t *testing.T) {
 	}
 
 	url := fmt.Sprintf(
-		"/machine/ssh/action/from/%d/to/%d?auth_id=%s",
+		"/machine/ssh/action/%d/to/%d?auth_id=%s",
 		srcOther.ID.Uint64(), dstOther.ID.Uint64(), authID.String(),
 	)
 	req := httptest.NewRequestWithContext(context.Background(), http.MethodGet, url, nil)

hscontrol/oidc.go

@@ -155,21 +155,21 @@ func (a *AuthProviderOIDC) authHandler(
 ) {
 	authID, err := authIDFromRequest(req)
 	if err != nil {
-		httpError(writer, err)
+		httpUserError(writer, err)
 		return
 	}
 
 	// Set the state and nonce cookies to protect against CSRF attacks
 	state, err := setCSRFCookie(writer, req, "state")
 	if err != nil {
-		httpError(writer, err)
+		httpUserError(writer, err)
 		return
 	}
 
 	// Set the state and nonce cookies to protect against CSRF attacks
 	nonce, err := setCSRFCookie(writer, req, "nonce")
 	if err != nil {
-		httpError(writer, err)
+		httpUserError(writer, err)
 		return
 	}
 
@@ -222,7 +222,7 @@ func (a *AuthProviderOIDC) OIDCCallbackHandler(
 ) {
 	code, state, err := extractCodeAndStateParamFromRequest(req)
 	if err != nil {
-		httpError(writer, err)
+		httpUserError(writer, err)
 		return
 	}
 
@@ -230,29 +230,29 @@ func (a *AuthProviderOIDC) OIDCCallbackHandler(
 
 	cookieState, err := req.Cookie(stateCookieName)
 	if err != nil {
-		httpError(writer, NewHTTPError(http.StatusBadRequest, "state not found", err))
+		httpUserError(writer, NewHTTPError(http.StatusBadRequest, "state not found", err))
 		return
 	}
 
 	if state != cookieState.Value {
-		httpError(writer, NewHTTPError(http.StatusForbidden, "state did not match", nil))
+		httpUserError(writer, NewHTTPError(http.StatusForbidden, "state did not match", nil))
 		return
 	}
 
 	oauth2Token, err := a.getOauth2Token(req.Context(), code, state)
 	if err != nil {
-		httpError(writer, err)
+		httpUserError(writer, err)
 		return
 	}
 
 	idToken, err := a.extractIDToken(req.Context(), oauth2Token)
 	if err != nil {
-		httpError(writer, err)
+		httpUserError(writer, err)
 		return
 	}
 
 	if idToken.Nonce == "" {
-		httpError(writer, NewHTTPError(http.StatusBadRequest, "nonce not found in IDToken", err))
+		httpUserError(writer, NewHTTPError(http.StatusBadRequest, "nonce not found in IDToken", err))
 		return
 	}
 
@@ -260,12 +260,12 @@ func (a *AuthProviderOIDC) OIDCCallbackHandler(
 
 	nonce, err := req.Cookie(nonceCookieName)
 	if err != nil {
-		httpError(writer, NewHTTPError(http.StatusBadRequest, "nonce not found", err))
+		httpUserError(writer, NewHTTPError(http.StatusBadRequest, "nonce not found", err))
 		return
 	}
 
 	if idToken.Nonce != nonce.Value {
-		httpError(writer, NewHTTPError(http.StatusForbidden, "nonce did not match", nil))
+		httpUserError(writer, NewHTTPError(http.StatusForbidden, "nonce did not match", nil))
 		return
 	}
 
@@ -273,7 +273,7 @@ func (a *AuthProviderOIDC) OIDCCallbackHandler(
 
 	var claims types.OIDCClaims
 	if err := idToken.Claims(&claims); err != nil { //nolint:noinlineerr
-		httpError(writer, fmt.Errorf("decoding ID token claims: %w", err))
+		httpUserError(writer, fmt.Errorf("decoding ID token claims: %w", err))
 		return
 	}
 
@@ -310,26 +310,17 @@ func (a *AuthProviderOIDC) OIDCCallbackHandler(
 	// against allowed emails, email domains, and groups.
 	err = doOIDCAuthorization(a.cfg, &claims)
 	if err != nil {
-		httpError(writer, err)
+		httpUserError(writer, err)
 		return
 	}
 
 	user, _, err := a.createOrUpdateUserFromClaim(&claims)
 	if err != nil {
-		log.Error().
-			Err(err).
-			Caller().
-			Msgf("could not create or update user")
-		writer.Header().Set("Content-Type", "text/plain; charset=utf-8")
-		writer.WriteHeader(http.StatusInternalServerError)
-
-		_, werr := writer.Write([]byte("Could not create or update user"))
-		if werr != nil {
-			log.Error().
-				Caller().
-				Err(werr).
-				Msg("Failed to write HTTP response")
-		}
+		httpUserError(writer, NewHTTPError(
+			http.StatusInternalServerError,
+			"could not create or update user",
+			err,
+		))
 
 		return
 	}
@@ -341,7 +332,7 @@ func (a *AuthProviderOIDC) OIDCCallbackHandler(
 	authInfo := a.getAuthInfoFromState(state)
 	if authInfo == nil {
 		log.Debug().Caller().Str("state", state).Msg("state not found in cache, login session may have expired")
-		httpError(writer, NewHTTPError(http.StatusGone, "login session expired, try again", nil))
+		httpUserError(writer, NewHTTPError(http.StatusGone, "login session expired, try again", nil))
 
 		return
 	}
@@ -367,7 +358,7 @@ func (a *AuthProviderOIDC) OIDCCallbackHandler(
 	authReq, ok := a.h.state.GetAuthCacheEntry(authInfo.AuthID)
 	if !ok {
 		log.Debug().Caller().Str("auth_id", authInfo.AuthID.String()).Msg("auth session expired before authorization completed")
-		httpError(writer, NewHTTPError(http.StatusGone, "login session expired, try again", nil))
+		httpUserError(writer, NewHTTPError(http.StatusGone, "login session expired, try again", nil))
 
 		return
 	}
@@ -376,7 +367,7 @@ func (a *AuthProviderOIDC) OIDCCallbackHandler(
 		log.Warn().Caller().
 			Str("auth_id", authInfo.AuthID.String()).
 			Msg("OIDC callback hit non-registration path with auth request that is not an SSH check binding")
-		httpError(writer, NewHTTPError(http.StatusBadRequest, "auth session is not for SSH check", nil))
+		httpUserError(writer, NewHTTPError(http.StatusBadRequest, "auth session is not for SSH check", nil))
 
 		return
 	}
@@ -389,7 +380,7 @@ func (a *AuthProviderOIDC) OIDCCallbackHandler(
 			Str("auth_id", authInfo.AuthID.String()).
 			Uint64("src_node_id", binding.SrcNodeID.Uint64()).
 			Msg("SSH check src node no longer exists")
-		httpError(writer, NewHTTPError(http.StatusGone, "src node no longer exists", nil))
+		httpUserError(writer, NewHTTPError(http.StatusGone, "src node no longer exists", nil))
 
 		return
 	}
@@ -404,7 +395,7 @@ func (a *AuthProviderOIDC) OIDCCallbackHandler(
 			Bool("src_is_tagged", srcNode.IsTagged()).
 			Str("oidc_user", user.Username()).
 			Msg("SSH check rejected: src node has no user owner")
-		httpError(writer, NewHTTPError(http.StatusForbidden, "src node has no user owner", nil))
+		httpUserError(writer, NewHTTPError(http.StatusForbidden, "src node has no user owner", nil))
 
 		return
 	}
@@ -417,7 +408,7 @@ func (a *AuthProviderOIDC) OIDCCallbackHandler(
 			Uint("oidc_user_id", user.ID).
 			Str("oidc_user", user.Username()).
 			Msg("SSH check rejected: OIDC user is not the owner of src node")
-		httpError(writer, NewHTTPError(http.StatusForbidden, "OIDC user is not the owner of the SSH source node", nil))
+		httpUserError(writer, NewHTTPError(http.StatusForbidden, "OIDC user is not the owner of the SSH source node", nil))
 
 		return
 	}
@@ -680,7 +671,7 @@ func (a *AuthProviderOIDC) renderRegistrationConfirmInterstitial(
 	authReq, ok := a.h.state.GetAuthCacheEntry(authID)
 	if !ok {
 		log.Debug().Caller().Str("auth_id", authID.String()).Msg("registration session expired before authorization completed")
-		httpError(writer, NewHTTPError(http.StatusGone, "login session expired, try again", nil))
+		httpUserError(writer, NewHTTPError(http.StatusGone, "login session expired, try again", nil))
 
 		return
 	}
@@ -689,14 +680,14 @@ func (a *AuthProviderOIDC) renderRegistrationConfirmInterstitial(
 		log.Warn().Caller().
 			Str("auth_id", authID.String()).
 			Msg("OIDC callback hit registration path with auth request that is not a node registration")
-		httpError(writer, NewHTTPError(http.StatusBadRequest, "auth session is not for node registration", nil))
+		httpUserError(writer, NewHTTPError(http.StatusBadRequest, "auth session is not for node registration", nil))
 
 		return
 	}
 
 	csrf, err := util.GenerateRandomStringURLSafe(32)
 	if err != nil {
-		httpError(writer, fmt.Errorf("generating csrf token: %w", err))
+		httpUserError(writer, fmt.Errorf("generating csrf token: %w", err))
 
 		return
 	}
@@ -748,14 +739,14 @@ func (a *AuthProviderOIDC) RegisterConfirmHandler(
 	req *http.Request,
 ) {
 	if req.Method != http.MethodPost {
-		httpError(writer, errMethodNotAllowed)
+		httpUserError(writer, errMethodNotAllowed)
 
 		return
 	}
 
 	authID, err := authIDFromRequest(req)
 	if err != nil {
-		httpError(writer, err)
+		httpUserError(writer, err)
 
 		return
 	}
@@ -766,54 +757,54 @@ func (a *AuthProviderOIDC) RegisterConfirmHandler(
 	req.Body = http.MaxBytesReader(writer, req.Body, 4*1024)
 
 	if err := req.ParseForm(); err != nil { //nolint:noinlineerr,gosec // body is bounded above
-		httpError(writer, NewHTTPError(http.StatusBadRequest, "invalid form", err))
+		httpUserError(writer, NewHTTPError(http.StatusBadRequest, "invalid form", err))
 
 		return
 	}
 
 	formCSRF := req.PostFormValue(registerConfirmCSRFCookie) //nolint:gosec // body is bounded above
 	if formCSRF == "" {
-		httpError(writer, NewHTTPError(http.StatusBadRequest, "missing csrf token", nil))
+		httpUserError(writer, NewHTTPError(http.StatusBadRequest, "missing csrf token", nil))
 
 		return
 	}
 
 	cookie, err := req.Cookie(registerConfirmCSRFCookie)
 	if err != nil {
-		httpError(writer, NewHTTPError(http.StatusForbidden, "missing csrf cookie", err))
+		httpUserError(writer, NewHTTPError(http.StatusForbidden, "missing csrf cookie", err))
 
 		return
 	}
 
 	if cookie.Value != formCSRF {
-		httpError(writer, NewHTTPError(http.StatusForbidden, "csrf token mismatch", nil))
+		httpUserError(writer, NewHTTPError(http.StatusForbidden, "csrf token mismatch", nil))
 
 		return
 	}
 
 	authReq, ok := a.h.state.GetAuthCacheEntry(authID)
 	if !ok {
-		httpError(writer, NewHTTPError(http.StatusGone, "registration session expired", nil))
+		httpUserError(writer, NewHTTPError(http.StatusGone, "registration session expired", nil))
 
 		return
 	}
 
 	pending := authReq.PendingConfirmation()
 	if pending == nil {
-		httpError(writer, NewHTTPError(http.StatusForbidden, "registration not OIDC-authorized", nil))
+		httpUserError(writer, NewHTTPError(http.StatusForbidden, "registration not OIDC-authorized", nil))
 
 		return
 	}
 
 	if pending.CSRF != cookie.Value {
-		httpError(writer, NewHTTPError(http.StatusForbidden, "csrf token does not match cached registration", nil))
+		httpUserError(writer, NewHTTPError(http.StatusForbidden, "csrf token does not match cached registration", nil))
 
 		return
 	}
 
 	user, err := a.h.state.GetUserByID(types.UserID(pending.UserID))
 	if err != nil {
-		httpError(writer, fmt.Errorf("looking up user: %w", err))
+		httpUserError(writer, fmt.Errorf("looking up user: %w", err))
 
 		return
 	}
@@ -821,12 +812,12 @@ func (a *AuthProviderOIDC) RegisterConfirmHandler(
 	newNode, err := a.handleRegistration(user, authID, pending.NodeExpiry)
 	if err != nil {
 		if errors.Is(err, db.ErrNodeNotFoundRegistrationCache) {
-			httpError(writer, NewHTTPError(http.StatusGone, "registration session expired", err))
+			httpUserError(writer, NewHTTPError(http.StatusGone, "registration session expired", err))
 
 			return
 		}
 
-		httpError(writer, err)
+		httpUserError(writer, err)
 
 		return
 	}

hscontrol/oidc_template_test.go

@@ -7,6 +7,71 @@ import (
 	"github.com/stretchr/testify/assert"
 )
 
+func TestAuthErrorTemplate(t *testing.T) {
+	tests := []struct {
+		name   string
+		result templates.AuthErrorResult
+	}{
+		{
+			name: "bad_request",
+			result: templates.AuthErrorResult{
+				Title:   "Headscale - Error",
+				Heading: "Bad Request",
+				Message: "The request could not be processed. Please try again.",
+			},
+		},
+		{
+			name: "forbidden",
+			result: templates.AuthErrorResult{
+				Title:   "Headscale - Error",
+				Heading: "Forbidden",
+				Message: "You are not authorized. Please contact your administrator.",
+			},
+		},
+		{
+			name: "gone_expired",
+			result: templates.AuthErrorResult{
+				Title:   "Headscale - Error",
+				Heading: "Gone",
+				Message: "Your session has expired. Please try again.",
+			},
+		},
+		{
+			name: "internal_server_error",
+			result: templates.AuthErrorResult{
+				Title:   "Headscale - Error",
+				Heading: "Internal Server Error",
+				Message: "Something went wrong. Please try again later.",
+			},
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			html := templates.AuthError(tt.result).Render()
+
+			// Verify the HTML contains expected structural elements
+			assert.Contains(t, html, "<!DOCTYPE html>")
+			assert.Contains(t, html, "<title>"+tt.result.Title+"</title>")
+			assert.Contains(t, html, tt.result.Heading)
+			assert.Contains(t, html, tt.result.Message)
+
+			// Verify Material for MkDocs design system CSS is present
+			assert.Contains(t, html, "Material for MkDocs")
+			assert.Contains(t, html, "Roboto")
+			assert.Contains(t, html, ".md-typeset")
+
+			// Verify SVG elements are present
+			assert.Contains(t, html, "<svg")
+			assert.Contains(t, html, "class=\"headscale-logo\"")
+			assert.Contains(t, html, "id=\"error-icon\"")
+
+			// Verify no success checkbox icon
+			assert.NotContains(t, html, "id=\"checkbox\"")
+		})
+	}
+}
+
 func TestAuthSuccessTemplate(t *testing.T) {
 	tests := []struct {
 		name   string

hscontrol/policy/matcher/matcher.go

@@ -53,6 +53,11 @@ func MatchFromFilterRule(rule tailcfg.FilterRule) Match {
 	return MatchFromStrings(rule.SrcIPs, dests)
 }
 
+// MatchFromStrings builds a Match from raw source and destination
+// strings. Unparseable entries are silently dropped (fail-open): the
+// resulting Match is narrower than the input described, but never
+// wider. Callers that need strict validation should pre-validate
+// their inputs via util.ParseIPSet.
 func MatchFromStrings(sources, destinations []string) Match {
 	srcs := new(netipx.IPSetBuilder)
 	dests := new(netipx.IPSetBuilder)
@@ -96,18 +101,20 @@ func (m *Match) DestsOverlapsPrefixes(prefixes ...netip.Prefix) bool {
 	return slices.ContainsFunc(prefixes, m.dests.OverlapsPrefix)
 }
 
-// DestsIsTheInternet reports if the destination contains "the internet"
-// which is a IPSet that represents "autogroup:internet" and is special
-// cased for exit nodes.
-// This checks if dests is a superset of TheInternet(), which handles
-// merged filter rules where TheInternet is combined with other destinations.
+// DestsIsTheInternet reports whether the destination covers "the
+// internet" — the set represented by autogroup:internet, special-cased
+// for exit nodes. Returns true if either family's /0 is contained
+// (0.0.0.0/0 or ::/0), or if dests is a superset of TheInternet(). A
+// single-family /0 counts because operators may write it directly and
+// it still denotes the whole internet for that family.
 func (m *Match) DestsIsTheInternet() bool {
 	if m.dests.ContainsPrefix(tsaddr.AllIPv4()) ||
 		m.dests.ContainsPrefix(tsaddr.AllIPv6()) {
 		return true
 	}
 
-	// Check if dests contains all prefixes of TheInternet (superset check)
+	// Superset-of-TheInternet check handles merged filter rules
+	// where the internet prefixes are combined with other dests.
 	theInternet := util.TheInternet()
 	for _, prefix := range theInternet.Prefixes() {
 		if !m.dests.ContainsPrefix(prefix) {

hscontrol/policy/matcher/matcher_test.go

@@ -2,6 +2,7 @@ package matcher
 
 import (
 	"net/netip"
+	"strings"
 	"testing"
 
 	"github.com/stretchr/testify/assert"
@@ -428,4 +429,44 @@ func TestDebugString(t *testing.T) {
 	assert.Contains(t, s, "Destinations:")
 	assert.Contains(t, s, "10.0.0.0/8")
 	assert.Contains(t, s, "192.168.1.0/24")
+
+	// Sources appear before Destinations in the output.
+	assert.Less(
+		t,
+		strings.Index(s, "Sources:"),
+		strings.Index(s, "Destinations:"),
+		"Sources section must precede Destinations",
+	)
+}
+
+func TestDebugString_Empty(t *testing.T) {
+	t.Parallel()
+
+	m := MatchFromStrings(nil, nil)
+
+	s := m.DebugString()
+	assert.Contains(t, s, "Match:")
+	assert.Contains(t, s, "Sources:")
+	assert.Contains(t, s, "Destinations:")
+	assert.NotContains(t, s, "/")
+}
+
+// TestMatchFromStrings_MalformedFailsOpen asserts that unparseable
+// entries are silently dropped and do not crash or widen the Match.
+func TestMatchFromStrings_MalformedFailsOpen(t *testing.T) {
+	t.Parallel()
+
+	m := MatchFromStrings(
+		[]string{"not-a-cidr", "10.0.0.0/8"},
+		[]string{"also-bogus", "192.168.1.0/24"},
+	)
+
+	assert.True(t, m.SrcsContainsIPs(netip.MustParseAddr("10.1.2.3")),
+		"valid src entry must still match")
+	assert.False(t, m.SrcsContainsIPs(netip.MustParseAddr("1.1.1.1")),
+		"malformed src entry must not widen the set")
+	assert.True(t, m.DestsContainsIP(netip.MustParseAddr("192.168.1.10")),
+		"valid dst entry must still match")
+	assert.False(t, m.DestsContainsIP(netip.MustParseAddr("8.8.8.8")),
+		"malformed dst entry must not widen the set")
 }

hscontrol/policy/policy_test.go

@@ -4,7 +4,6 @@ import (
 	"fmt"
 	"net/netip"
 	"testing"
-	"time"
 
 	"github.com/google/go-cmp/cmp"
 	"github.com/juanfont/headscale/hscontrol/policy/matcher"
@@ -952,11 +951,13 @@ func TestReduceNodesFromPolicy(t *testing.T) {
   ]
 }`,
 			node: n(1, "100.64.0.1", "mobile", "mobile"),
-			// autogroup:internet does not generate packet filters - it's handled
-			// by exit node routing via AllowedIPs, not by packet filtering.
-			// Only server is visible through the mobile -> server:80 rule.
+			// autogroup:internet emits no client packet filter, but it
+			// must still produce a matcher: Node.CanAccess uses
+			// matcher.DestsIsTheInternet() + IsExitNode() to surface
+			// exit-node peers (juanfont/headscale#3212).
 			want: types.Nodes{
 				n(2, "100.64.0.2", "server", "server"),
+				n(3, "100.64.0.3", "exit", "server", "0.0.0.0/0", "::/0"),
 			},
 			wantMatchers: 1,
 		},
@@ -1264,11 +1265,11 @@ func TestSSHPolicyRules(t *testing.T) {
 					},
 					Action: &tailcfg.SSHAction{
 						Accept:                    false,
-						SessionDuration:           24 * time.Hour,
-						HoldAndDelegate:           "unused-url/machine/ssh/action/from/$SRC_NODE_ID/to/$DST_NODE_ID?ssh_user=$SSH_USER&local_user=$LOCAL_USER",
-						AllowAgentForwarding:      true,
-						AllowLocalPortForwarding:  true,
-						AllowRemotePortForwarding: true,
+						SessionDuration:           0,
+						HoldAndDelegate:           "unused-url/machine/ssh/action/$SRC_NODE_ID/to/$DST_NODE_ID?local_user=$LOCAL_USER",
+						AllowAgentForwarding:      false,
+						AllowLocalPortForwarding:  false,
+						AllowRemotePortForwarding: false,
 					},
 				},
 			}},

hscontrol/policy/policyutil/doc.go

@@ -0,0 +1,9 @@
+// Package policyutil contains pure functions that transform compiled
+// policy rules for a specific node. The headline function is
+// ReduceFilterRules, which filters global rules down to those relevant
+// to one node.
+//
+// A node's SubnetRoutes (approved, non-exit) participate in rule
+// matching so subnet routers receive filter rules for destinations
+// their subnets cover — the fix for issue #3169.
+package policyutil

hscontrol/policy/policyutil/reduce.go

@@ -6,6 +6,7 @@ import (
 
 	"github.com/juanfont/headscale/hscontrol/types"
 	"github.com/juanfont/headscale/hscontrol/util"
+	"go4.org/netipx"
 	"tailscale.com/tailcfg"
 )
 
@@ -17,6 +18,8 @@ import (
 // to this function. Use PolicyManager.FilterForNode() instead, which handles both cases.
 func ReduceFilterRules(node types.NodeView, rules []tailcfg.FilterRule) []tailcfg.FilterRule {
 	ret := []tailcfg.FilterRule{}
+	subnetRoutes := node.SubnetRoutes()
+	hasExitRoutes := node.IsExitNode()
 
 	for _, rule := range rules {
 		// Handle CapGrant rules separately — they use CapGrant[].Dsts
@@ -33,18 +36,16 @@ func ReduceFilterRules(node types.NodeView, rules []tailcfg.FilterRule) []tailcf
 		// record if the rule is actually relevant for the given node.
 		var dests []tailcfg.NetPortRange
 
-	DEST_LOOP:
 		for _, dest := range rule.DstPorts {
 			expanded, err := util.ParseIPSet(dest.IP, nil)
-			// Fail closed, if we can't parse it, then we should not allow
-			// access.
+			// Fail closed: unparseable dests are dropped.
 			if err != nil {
-				continue DEST_LOOP
+				continue
 			}
 
 			if node.InIPSet(expanded) {
 				dests = append(dests, dest)
-				continue DEST_LOOP
+				continue
 			}
 
 			// If the node has approved subnet routes, preserve
@@ -55,26 +56,45 @@ func ReduceFilterRules(node types.NodeView, rules []tailcfg.FilterRule) []tailcf
 			// Exit routes (0.0.0.0/0, ::/0) are excluded by
 			// SubnetRoutes() and handled separately via
 			// AllowedIPs/routing.
-			for _, subnetRoute := range node.SubnetRoutes() {
-				if expanded.OverlapsPrefix(subnetRoute) {
-					dests = append(dests, dest)
-					continue DEST_LOOP
-				}
+			if slices.ContainsFunc(subnetRoutes, expanded.OverlapsPrefix) {
+				dests = append(dests, dest)
+				continue
+			}
+
+			// Exit-route advertisers need rules targeting the
+			// public internet so the kernel filter accepts
+			// traffic forwarded by autogroup:internet sources.
+			if hasExitRoutes && ipSetSubsetOf(expanded, util.TheInternet()) {
+				dests = append(dests, dest)
 			}
 		}
 
 		if len(dests) > 0 {
-			ret = append(ret, tailcfg.FilterRule{
-				SrcIPs:   rule.SrcIPs,
-				DstPorts: dests,
-				IPProto:  rule.IPProto,
-			})
+			// Struct-copy preserves any unknown future FilterRule
+			// fields.
+			out := rule
+			out.DstPorts = dests
+			ret = append(ret, out)
 		}
 	}
 
 	return ret
 }
 
+func ipSetSubsetOf(candidate, container *netipx.IPSet) bool {
+	if candidate == nil || container == nil {
+		return false
+	}
+
+	for _, pref := range candidate.Prefixes() {
+		if !container.ContainsPrefix(pref) {
+			return false
+		}
+	}
+
+	return true
+}
+
 // reduceCapGrantRule filters a CapGrant rule to only include CapGrant
 // entries whose Dsts match the given node's IPs. When a broad prefix
 // (e.g. 100.64.0.0/10 from dst:*) contains a node's IP, it is
@@ -87,6 +107,7 @@ func reduceCapGrantRule(
 	var capGrants []tailcfg.CapGrant
 
 	nodeIPs := node.IPs()
+	subnetRoutes := node.SubnetRoutes()
 
 	for _, cg := range rule.CapGrant {
 		// Collect the node's IPs that fall within any of this
@@ -111,13 +132,15 @@ func reduceCapGrantRule(
 			}
 		}
 
-		// Also check approved subnet routes — nodes serving
-		// approved routes should receive CapGrant rules for
-		// destinations that overlap those routes. SubnetRoutes()
-		// excludes both unapproved and exit routes, matching
-		// Tailscale SaaS behavior.
+		// Asymmetric on purpose: the IP-match loop above narrows broad
+		// prefixes to node-specific /32 or /128 so peers receive only
+		// the minimum routing surface. The route-match loop below
+		// preserves the original prefix so the subnet-serving node
+		// receives the full CapGrant scope. SubnetRoutes() excludes
+		// both unapproved and exit routes, matching Tailscale SaaS
+		// behavior.
 		for _, dst := range cg.Dsts {
-			for _, subnetRoute := range node.SubnetRoutes() {
+			for _, subnetRoute := range subnetRoutes {
 				if dst.Overlaps(subnetRoute) {
 					// For route overlaps, keep the original prefix.
 					matchingDsts = append(matchingDsts, dst)
@@ -126,6 +149,13 @@ func reduceCapGrantRule(
 		}
 
 		if len(matchingDsts) > 0 {
+			// A Dst can be appended twice when a broad prefix both
+			// contains a node IP and overlaps one of its approved
+			// subnet routes. Sort + Compact dedups; netip.Prefix is
+			// comparable so Compact works with ==.
+			slices.SortFunc(matchingDsts, netip.Prefix.Compare)
+			matchingDsts = slices.Compact(matchingDsts)
+
 			capGrants = append(capGrants, tailcfg.CapGrant{
 				Dsts:   matchingDsts,
 				CapMap: cg.CapMap,

hscontrol/policy/policyutil/reduce_test.go

@@ -1203,6 +1203,55 @@ func TestReduceFilterRulesCapGrant(t *testing.T) {
 			},
 			want: []tailcfg.FilterRule{},
 		},
+		{
+			// A broad prefix that both contains the node IP (/32 narrow)
+			// and overlaps one of its approved subnet routes (route
+			// preserved) would otherwise be emitted twice.
+			name: "capgrant-ip-and-route-overlap-dedup",
+			node: &types.Node{
+				IPv4: ap("100.64.0.1"),
+				IPv6: ap("fd7a:115c:a1e0::1"),
+				Hostinfo: &tailcfg.Hostinfo{
+					RoutableIPs: []netip.Prefix{
+						netip.MustParsePrefix("100.64.0.0/24"),
+					},
+				},
+				ApprovedRoutes: []netip.Prefix{
+					netip.MustParsePrefix("100.64.0.0/24"),
+				},
+			},
+			rules: []tailcfg.FilterRule{
+				{
+					SrcIPs: []string{"*"},
+					CapGrant: []tailcfg.CapGrant{
+						{
+							Dsts: []netip.Prefix{
+								netip.MustParsePrefix("100.64.0.0/24"),
+							},
+							CapMap: tailcfg.PeerCapMap{
+								"tailscale.com/cap/relay-target": nil,
+							},
+						},
+					},
+				},
+			},
+			want: []tailcfg.FilterRule{
+				{
+					SrcIPs: []string{"*"},
+					CapGrant: []tailcfg.CapGrant{
+						{
+							Dsts: []netip.Prefix{
+								netip.MustParsePrefix("100.64.0.1/32"),
+								netip.MustParsePrefix("100.64.0.0/24"),
+							},
+							CapMap: tailcfg.PeerCapMap{
+								"tailscale.com/cap/relay-target": nil,
+							},
+						},
+					},
+				},
+			},
+		},
 	}
 
 	for _, tt := range tests {

hscontrol/policy/v2/compiled.go

@@ -5,6 +5,7 @@ import (
 	"slices"
 
 	"github.com/juanfont/headscale/hscontrol/types"
+	"github.com/juanfont/headscale/hscontrol/util"
 	"github.com/rs/zerolog/log"
 	"go4.org/netipx"
 	"tailscale.com/tailcfg"
@@ -72,9 +73,10 @@ type viaGrantData struct {
 	srcIPStrings      []string
 }
 
-// userNodeIndex maps user IDs to their untagged nodes. Precomputed
-// once per node-set change, used by compileAutogroupSelf to avoid
-// O(N) scans per self-grant per node.
+// userNodeIndex maps user IDs to their untagged nodes. Built once per
+// policy or node-set change and read from many goroutines under
+// PolicyManager.mu; readers must hold the lock (or the snapshot
+// returned to them).
 type userNodeIndex map[uint][]types.NodeView
 
 func buildUserNodeIndex(
@@ -100,7 +102,7 @@ func (pol *Policy) compileGrants(
 	users types.Users,
 	nodes views.Slice[types.NodeView],
 ) []compiledGrant {
-	if pol == nil || (pol.ACLs == nil && len(pol.Grants) == 0) {
+	if pol == nil || (pol.ACLs == nil && pol.Grants == nil) {
 		return nil
 	}
 
@@ -269,7 +271,9 @@ func (pol *Policy) compileOneViaGrant(
 
 // resolveSources resolves grant sources per-alias, returning the
 // resolved addresses and a separate slice of non-wildcard sources.
-// This is the shared source resolution used by all grant categories.
+// This is the canonical source-resolution path. Its output lands in
+// compiledGrant.srcIPStrings (among other places) and callers on the
+// hot path should prefer reading that over calling Resolve again.
 func resolveSources(
 	pol *Policy,
 	sources Aliases,
@@ -457,8 +461,9 @@ func hasPerNodeGrants(grants []compiledGrant) bool {
 }
 
 // globalFilterRules extracts global filter rules from compiled
-// grants. Only includes pre-compiled rules from non-via grants.
-// Via grants produce no global rules (they are per-node only).
+// grants. Via grants produce no global rules (they are per-node
+// only); regular grants contribute their full pre-compiled ruleset;
+// self grants contribute their non-self portion.
 func globalFilterRules(grants []compiledGrant) []tailcfg.FilterRule {
 	var rules []tailcfg.FilterRule
 
@@ -667,11 +672,10 @@ func compileViaForNode(
 		return nil
 	}
 
-	// Find matching destination prefixes.
+	// Find matching destination prefixes. SubnetRoutes() excludes exit
+	// routes, so the *Prefix check below sees only subnet advertisements;
+	// the *AutoGroup AutoGroupInternet branch checks IsExitNode() instead.
 	nodeSubnetRoutes := node.SubnetRoutes()
-	if len(nodeSubnetRoutes) == 0 {
-		return nil
-	}
 
 	var viaDstPrefixes []netip.Prefix
 
@@ -685,8 +689,19 @@ func compileViaForNode(
 				)
 			}
 		case *AutoGroup:
-			// autogroup:internet via grants do not produce
-			// PacketFilter rules on exit nodes.
+			// autogroup:internet on a via-tagged exit advertiser
+			// becomes a rule whose DstPorts enumerate
+			// util.TheInternet(). The matchers derived from this
+			// rule let Node.CanAccess surface the exit node to the
+			// grant source via DestsIsTheInternet. ReduceFilterRules
+			// strips the rule from the wire format on non-exit
+			// advertisers, preserving SaaS PacketFilter encoding.
+			if d.Is(AutoGroupInternet) && node.IsExitNode() {
+				viaDstPrefixes = append(
+					viaDstPrefixes,
+					util.TheInternet().Prefixes()...,
+				)
+			}
 		}
 	}
 

hscontrol/policy/v2/filter.go

@@ -1,6 +1,7 @@
 package v2
 
 import (
+	"cmp"
 	"errors"
 	"fmt"
 	"net/netip"
@@ -62,7 +63,7 @@ func companionCapGrantRules(
 	}
 
 	slices.SortFunc(pairs, func(a, b pair) int {
-		return strings.Compare(string(a.original), string(b.original))
+		return cmp.Compare(a.original, b.original)
 	})
 
 	companions := make([]tailcfg.FilterRule, 0, len(pairs))
@@ -137,7 +138,7 @@ func (pol *Policy) compileFilterRules(
 	users types.Users,
 	nodes views.Slice[types.NodeView],
 ) ([]tailcfg.FilterRule, error) {
-	if pol == nil || (pol.ACLs == nil && len(pol.Grants) == 0) {
+	if pol == nil || (pol.ACLs == nil && pol.Grants == nil) {
 		return tailcfg.FilterAllowAll, nil
 	}
 
@@ -165,12 +166,6 @@ func (pol *Policy) destinationsToNetPortRange(
 			continue
 		}
 
-		// autogroup:internet does not generate packet filters - it's handled
-		// by exit node routing via AllowedIPs, not by packet filtering.
-		if ag, isAutoGroup := dest.(*AutoGroup); isAutoGroup && ag.Is(AutoGroupInternet) {
-			continue
-		}
-
 		ips, err := dest.Resolve(pol, users, nodes)
 		if err != nil {
 			log.Trace().Caller().Err(err).Msgf("resolving destination ips")
@@ -229,6 +224,8 @@ var sshAccept = tailcfg.SSHAction{
 // checkPeriodFromRule extracts the check period duration from an SSH rule.
 // Returns SSHCheckPeriodDefault if no checkPeriod is configured,
 // 0 if checkPeriod is "always", or the configured duration otherwise.
+// This is used server-side by SSHCheckParams to resolve the real period
+// when the client calls back; the wire format always sends 0.
 func checkPeriodFromRule(rule SSH) time.Duration {
 	switch {
 	case rule.CheckPeriod == nil:
@@ -240,13 +237,13 @@ func checkPeriodFromRule(rule SSH) time.Duration {
 	}
 }
 
-func sshCheck(baseURL string, duration time.Duration) tailcfg.SSHAction {
-	holdURL := baseURL + "/machine/ssh/action/from/$SRC_NODE_ID/to/$DST_NODE_ID?ssh_user=$SSH_USER&local_user=$LOCAL_USER"
+func sshCheck(baseURL string, _ time.Duration) tailcfg.SSHAction {
+	holdURL := baseURL + "/machine/ssh/action/$SRC_NODE_ID/to/$DST_NODE_ID?local_user=$LOCAL_USER"
 
 	return tailcfg.SSHAction{
 		Reject:          false,
 		Accept:          false,
-		SessionDuration: duration,
+		SessionDuration: 0,
 		// Replaced in the client:
 		//   * $SRC_NODE_IP (URL escaped)
 		//   * $SRC_NODE_ID (Node.ID as int64 string)
@@ -255,9 +252,9 @@ func sshCheck(baseURL string, duration time.Duration) tailcfg.SSHAction {
 		//   * $SSH_USER (URL escaped, ssh user requested)
 		//   * $LOCAL_USER (URL escaped, local user mapped)
 		HoldAndDelegate:           holdURL,
-		AllowAgentForwarding:      true,
-		AllowLocalPortForwarding:  true,
-		AllowRemotePortForwarding: true,
+		AllowAgentForwarding:      false,
+		AllowLocalPortForwarding:  false,
+		AllowRemotePortForwarding: false,
 	}
 }
 

hscontrol/policy/v2/filter_test.go

@@ -1071,7 +1071,7 @@ func TestCompileSSHPolicy_CheckAction(t *testing.T) {
 	assert.False(t, rule.Action.Reject)
 	assert.NotEmpty(t, rule.Action.HoldAndDelegate)
 	assert.Contains(t, rule.Action.HoldAndDelegate, "/machine/ssh/action/")
-	assert.Equal(t, 24*time.Hour, rule.Action.SessionDuration)
+	assert.Equal(t, time.Duration(0), rule.Action.SessionDuration)
 
 	// Verify check params are NOT encoded in the URL (looked up server-side).
 	assert.NotContains(t, rule.Action.HoldAndDelegate, "check_explicit")
@@ -2632,25 +2632,24 @@ func TestCompileSSHPolicy_CheckPeriodVariants(t *testing.T) {
 
 	nodes := types.Nodes{&node}
 
+	// SaaS always sends SessionDuration=0 in the wire format
+	// regardless of checkPeriod. The check period is resolved
+	// server-side, not embedded in the SSHAction.
 	tests := []struct {
-		name         string
-		checkPeriod  *SSHCheckPeriod
-		wantDuration time.Duration
+		name        string
+		checkPeriod *SSHCheckPeriod
 	}{
 		{
-			name:         "nil period defaults to 12h",
-			checkPeriod:  nil,
-			wantDuration: SSHCheckPeriodDefault,
+			name:        "nil period",
+			checkPeriod: nil,
 		},
 		{
-			name:         "always period uses 0",
-			checkPeriod:  &SSHCheckPeriod{Always: true},
-			wantDuration: 0,
+			name:        "always period",
+			checkPeriod: &SSHCheckPeriod{Always: true},
 		},
 		{
-			name:         "explicit 2h",
-			checkPeriod:  &SSHCheckPeriod{Duration: 2 * time.Hour},
-			wantDuration: 2 * time.Hour,
+			name:        "explicit 2h",
+			checkPeriod: &SSHCheckPeriod{Duration: 2 * time.Hour},
 		},
 	}
 
@@ -2682,7 +2681,7 @@ func TestCompileSSHPolicy_CheckPeriodVariants(t *testing.T) {
 			require.Len(t, sshPolicy.Rules, 1)
 
 			rule := sshPolicy.Rules[0]
-			assert.Equal(t, tt.wantDuration, rule.Action.SessionDuration)
+			assert.Equal(t, time.Duration(0), rule.Action.SessionDuration)
 			// Check params must NOT be in the URL; they are
 			// resolved server-side via SSHCheckParams.
 			assert.NotContains(t, rule.Action.HoldAndDelegate, "check_explicit")
@@ -3538,11 +3537,26 @@ func TestFilterAllowAllFix(t *testing.T) {
 			wantFilterAllow: true,
 		},
 		{
-			name: "nil ACLs and empty grants returns FilterAllowAll",
+			name: "nil ACLs and empty grants denies all",
 			pol: &Policy{
 				Grants: []Grant{},
 			},
-			wantFilterAllow: true,
+			wantFilterAllow: false,
+		},
+		{
+			name: "empty ACLs and nil grants denies all",
+			pol: &Policy{
+				ACLs: []ACL{},
+			},
+			wantFilterAllow: false,
+		},
+		{
+			name: "empty ACLs and empty grants denies all",
+			pol: &Policy{
+				ACLs:   []ACL{},
+				Grants: []Grant{},
+			},
+			wantFilterAllow: false,
 		},
 		{
 			name: "both ACLs and grants should not return FilterAllowAll",
@@ -3654,6 +3668,27 @@ func TestCompileViaGrant(t *testing.T) {
 		Hostinfo: &tailcfg.Hostinfo{},
 	}
 
+	// Expected rule for autogroup:internet on a via-tagged exit
+	// advertiser: SrcIPs scoped to the grant source, DstPorts
+	// enumerating util.TheInternet() prefixes.
+	internetDstPorts := make(
+		[]tailcfg.NetPortRange, 0, len(util.TheInternet().Prefixes()),
+	)
+
+	for _, p := range util.TheInternet().Prefixes() {
+		internetDstPorts = append(internetDstPorts, tailcfg.NetPortRange{
+			IP:    p.String(),
+			Ports: tailcfg.PortRangeAny,
+		})
+	}
+
+	internetWant := []tailcfg.FilterRule{
+		{
+			SrcIPs:   []string{"100.64.0.10"},
+			DstPorts: internetDstPorts,
+		},
+	}
+
 	tests := []struct {
 		name    string
 		grant   Grant
@@ -3710,11 +3745,12 @@ func TestCompileViaGrant(t *testing.T) {
 			},
 		},
 		{
-			// autogroup:internet via grants do NOT produce PacketFilter rules
-			// on exit nodes. Tailscale SaaS handles exit traffic forwarding
-			// through the client's exit node mechanism, not PacketFilter.
-			// Verified by golden captures GRANT-V14 through GRANT-V36.
-			name: "autogroup:internet with exit routes produces no rules",
+			// autogroup:internet on a via-tagged exit advertiser
+			// produces a rule with DstPorts enumerating
+			// util.TheInternet(). The matchers derived from this
+			// rule let Node.CanAccess surface the exit node to
+			// grant sources via DestsIsTheInternet.
+			name: "autogroup:internet with exit routes produces TheInternet rule",
 			grant: Grant{
 				Sources:           Aliases{up("testuser@")},
 				Destinations:      Aliases{agp(string(AutoGroupInternet))},
@@ -3724,7 +3760,7 @@ func TestCompileViaGrant(t *testing.T) {
 			node:  exitNode,
 			nodes: types.Nodes{exitNode, srcNode},
 			pol:   &Policy{},
-			want:  nil,
+			want:  internetWant,
 		},
 		{
 			name: "autogroup:internet without exit routes returns nil",
@@ -4087,6 +4123,14 @@ func TestDestinationsToNetPortRange_AutogroupInternet(t *testing.T) {
 	pol := &Policy{}
 	ports := []tailcfg.PortRange{tailcfg.PortRangeAny}
 
+	// autogroup:internet must surface as DstPorts (not be skipped at
+	// compile time). The matcher derived from these FilterRules is
+	// what makes Node.CanAccess return true for exit-node peers via
+	// DestsIsTheInternet (#3212). The wire format is currently the
+	// canonical CIDR breakdown of util.TheInternet(); aligning it to
+	// the SaaS range form is tracked separately.
+	internetPrefixCount := len(util.TheInternet().Prefixes())
+
 	tests := []struct {
 		name     string
 		dests    Aliases
@@ -4094,9 +4138,9 @@ func TestDestinationsToNetPortRange_AutogroupInternet(t *testing.T) {
 		wantStar bool
 	}{
 		{
-			name:    "autogroup:internet produces no DstPorts",
+			name:    "autogroup:internet produces TheInternet DstPorts",
 			dests:   Aliases{agp(string(AutoGroupInternet))},
-			wantLen: 0,
+			wantLen: internetPrefixCount,
 		},
 		{
 			name:     "wildcard produces DstPorts with star",

hscontrol/policy/v2/issue_3212_test.go

@@ -0,0 +1,172 @@
+// Tests pinned against tscap captures for juanfont/headscale#3212.
+//
+// The captures were taken on 2026-04-28 against a live Tailscale SaaS
+// tailnet. They reproduce the literal #3212 setup: an ACL granting
+// access to autogroup:internet:* combined with autoApprovers.exitNode
+// approving exit routes on tagged exit nodes. SaaS surfaces those exit
+// nodes as peers in the ACL source's netmap with 0.0.0.0/0 and ::/0 in
+// AllowedIPs. Headscale must do the same — that is the user-visible UX
+// driving `tailscale exit-node list`.
+//
+// Captures live under testdata/issue_3212/ rather than testdata/
+// routes_results/ so the broader TestRoutesCompat / *PeerAllowedIPs /
+// *ReduceRoutes machinery does not pull them in. Those tests assume a
+// PacketFilterRules wire format (CIDR prefix per dest entry) that
+// differs from what SaaS emits for autogroup:internet (range form per
+// IPSet range — e.g. "0.0.0.0-9.255.255.255"). Aligning that wire
+// format is tracked separately; the #3212 fix is about peer
+// visibility, not packet-filter encoding.
+
+package v2
+
+import (
+	"path/filepath"
+	"slices"
+	"strings"
+	"testing"
+
+	"github.com/juanfont/headscale/hscontrol/types"
+	"github.com/juanfont/headscale/hscontrol/types/testcapture"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+	"tailscale.com/net/tsaddr"
+)
+
+// TestIssue3212AutogroupInternetExitVisibility loads the b17/b18
+// SaaS captures and asserts headscale's BuildPeerMap surfaces every
+// exit-route advertiser to every ACL-source node — matching the peer
+// list in the captured netmap.
+//
+// The bug fixed by this PR (#3212) was that headscale skipped
+// autogroup:internet during FilterRule compilation, which silently
+// dropped the matchers that Node.CanAccess reads via DestsIsTheInternet.
+// The captures pin the SaaS-equivalent expectation as a regression
+// guard so the same skip cannot sneak back in unnoticed.
+func TestIssue3212AutogroupInternetExitVisibility(t *testing.T) {
+	t.Parallel()
+
+	files := []string{
+		"routes-b17-autogroup-internet-with-exit-autoapprover",
+		"routes-b18-autogroup-internet-wildcard-src-with-exit-autoapprover",
+	}
+
+	for _, testID := range files {
+		path := filepath.Join(
+			"testdata", "issue_3212", testID+".hujson",
+		)
+		tf := loadRoutesTestFile(t, path)
+
+		t.Run(tf.TestID, func(t *testing.T) {
+			t.Parallel()
+
+			users, nodes := buildRoutesUsersAndNodes(t, tf.Topology)
+			policyJSON := convertPolicyUserEmails(tf.Input.FullPolicy)
+
+			pm, err := NewPolicyManager(
+				policyJSON, users, nodes.ViewSlice(),
+			)
+			require.NoErrorf(t, err,
+				"%s: failed to create PolicyManager", tf.TestID,
+			)
+
+			peerMap := pm.BuildPeerMap(nodes.ViewSlice())
+
+			expected := expectedExitPeerVisibility(t, tf, nodes)
+			require.NotEmptyf(t, expected,
+				"%s: capture exposes no source→exit relationships — "+
+					"the test is meaningless if SaaS itself never "+
+					"surfaced an exit node to a source",
+				tf.TestID,
+			)
+
+			for srcName, exitNames := range expected {
+				srcNode := findNodeByGivenName(nodes, srcName)
+				require.NotNilf(t, srcNode,
+					"%s: src node %q missing from topology",
+					tf.TestID, srcName,
+				)
+
+				peerIDs := make(
+					map[types.NodeID]struct{},
+					len(peerMap[srcNode.ID]),
+				)
+				for _, p := range peerMap[srcNode.ID] {
+					peerIDs[p.ID()] = struct{}{}
+				}
+
+				for _, exitName := range exitNames {
+					exitNode := findNodeByGivenName(nodes, exitName)
+					require.NotNilf(t, exitNode,
+						"%s: exit node %q missing from topology",
+						tf.TestID, exitName,
+					)
+
+					_, found := peerIDs[exitNode.ID]
+					assert.Truef(t, found,
+						"%s: source %q must see exit node %q "+
+							"as a peer via the autogroup:internet "+
+							"ACL — Tailscale SaaS does (#3212)",
+						tf.TestID, srcName, exitName,
+					)
+				}
+			}
+		})
+	}
+}
+
+// expectedExitPeerVisibility extracts (source-node, exit-node) pairs
+// the capture's netmaps witness. A node is treated as an exit-route
+// advertiser when its ApprovedRoutes contain 0.0.0.0/0 or ::/0;
+// a (source, exit) pair is recorded when the source's captured netmap
+// lists the advertiser as a peer with 0.0.0.0/0 or ::/0 in AllowedIPs.
+func expectedExitPeerVisibility(
+	t *testing.T,
+	tf *testcapture.Capture,
+	nodes types.Nodes,
+) map[string][]string {
+	t.Helper()
+
+	v4Exit := tsaddr.AllIPv4()
+	v6Exit := tsaddr.AllIPv6()
+
+	exitAdvertisers := make(map[string]bool)
+
+	for _, n := range nodes {
+		if slices.Contains(n.ApprovedRoutes, v4Exit) ||
+			slices.Contains(n.ApprovedRoutes, v6Exit) {
+			exitAdvertisers[n.GivenName] = true
+		}
+	}
+
+	expected := make(map[string][]string)
+
+	for srcName, capture := range tf.Captures {
+		if capture.Netmap == nil {
+			continue
+		}
+
+		var seen []string
+
+		for _, peer := range capture.Netmap.Peers {
+			peerName := strings.Split(peer.Name(), ".")[0]
+
+			if !exitAdvertisers[peerName] {
+				continue
+			}
+
+			peerAllowed := peer.AllowedIPs().AsSlice()
+			if !slices.Contains(peerAllowed, v4Exit) &&
+				!slices.Contains(peerAllowed, v6Exit) {
+				continue
+			}
+
+			seen = append(seen, peerName)
+		}
+
+		if len(seen) > 0 {
+			expected[srcName] = seen
+		}
+	}
+
+	return expected
+}

hscontrol/policy/v2/issue_3233_test.go

@@ -0,0 +1,106 @@
+// A via grant scoping autogroup:internet to a tag must surface only
+// the matching exit node to the source — not strip every exit node
+// from the source's view.
+//
+// Spec: https://tailscale.com/docs/features/access-control/grants/grants-via#route-users-through-exit-nodes-based-on-location
+package v2
+
+import (
+	"net/netip"
+	"slices"
+	"testing"
+
+	"github.com/juanfont/headscale/hscontrol/types"
+	"github.com/stretchr/testify/require"
+	"gorm.io/gorm"
+	"tailscale.com/net/tsaddr"
+	"tailscale.com/tailcfg"
+)
+
+// TestIssue3233ViaInternetExitVisibility loads a policy where alice's
+// only access to autogroup:internet is via tag:exit1. Alice sees her
+// tag:exit1 exit node as a peer with 0.0.0.0/0 + ::/0 in AllowedIPs,
+// and does not see bob's tag:exit2 exit node.
+func TestIssue3233ViaInternetExitVisibility(t *testing.T) {
+	t.Parallel()
+
+	users := types.Users{
+		{Model: gorm.Model{ID: 1}, Name: "alice", Email: "alice@headscale.net"},
+		{Model: gorm.Model{ID: 2}, Name: "bob", Email: "bob@headscale.net"},
+	}
+
+	exitRoutes := []netip.Prefix{tsaddr.AllIPv4(), tsaddr.AllIPv6()}
+
+	aliceLaptop := node("alice-laptop", "100.64.0.10", "fd7a:115c:a1e0::a", users[0])
+	aliceLaptop.ID = 1
+
+	aliceExit := node("alice-exit", "100.64.0.11", "fd7a:115c:a1e0::b", users[0])
+	aliceExit.ID = 2
+	aliceExit.Tags = []string{"tag:exit1"}
+	aliceExit.Hostinfo = &tailcfg.Hostinfo{RoutableIPs: exitRoutes}
+	aliceExit.ApprovedRoutes = exitRoutes
+
+	bobExit := node("bob-exit", "100.64.0.21", "fd7a:115c:a1e0::15", users[1])
+	bobExit.ID = 3
+	bobExit.Tags = []string{"tag:exit2"}
+	bobExit.Hostinfo = &tailcfg.Hostinfo{RoutableIPs: exitRoutes}
+	bobExit.ApprovedRoutes = exitRoutes
+
+	nodes := types.Nodes{aliceLaptop, aliceExit, bobExit}
+
+	policy := `{
+		"tagOwners": {
+			"tag:exit1": ["alice@headscale.net"],
+			"tag:exit2": ["bob@headscale.net"]
+		},
+		"grants": [
+			{
+				"src": ["alice@headscale.net"],
+				"dst": ["autogroup:internet"],
+				"via": ["tag:exit1"],
+				"ip": ["*"]
+			}
+		]
+	}`
+
+	pm, err := NewPolicyManager([]byte(policy), users, nodes.ViewSlice())
+	require.NoError(t, err)
+
+	t.Run("BuildPeerMap_includes_via_tagged_exit", func(t *testing.T) {
+		t.Parallel()
+
+		peerMap := pm.BuildPeerMap(nodes.ViewSlice())
+
+		require.True(t,
+			slices.ContainsFunc(peerMap[aliceLaptop.ID], func(n types.NodeView) bool {
+				return n.ID() == aliceExit.ID
+			}),
+			"alice must see her tag:exit1 exit node as a peer")
+
+		require.False(t,
+			slices.ContainsFunc(peerMap[aliceLaptop.ID], func(n types.NodeView) bool {
+				return n.ID() == bobExit.ID
+			}),
+			"alice must not see bob's tag:exit2 exit node — via grant scopes to tag:exit1")
+	})
+
+	t.Run("ViaRoutesForPeer_includes_exit_for_matching_tag", func(t *testing.T) {
+		t.Parallel()
+
+		result := pm.ViaRoutesForPeer(aliceLaptop.View(), aliceExit.View())
+		require.Contains(t, result.Include, tsaddr.AllIPv4(),
+			"alice viewing tag:exit1 exit must Include 0.0.0.0/0 — drives AllowedIPs in state.RoutesForPeer")
+		require.Contains(t, result.Include, tsaddr.AllIPv6(),
+			"alice viewing tag:exit1 exit must Include ::/0 — drives AllowedIPs in state.RoutesForPeer")
+	})
+
+	t.Run("ViaRoutesForPeer_excludes_exit_for_other_tag", func(t *testing.T) {
+		t.Parallel()
+
+		result := pm.ViaRoutesForPeer(aliceLaptop.View(), bobExit.View())
+		require.Contains(t, result.Exclude, tsaddr.AllIPv4(),
+			"alice viewing tag:exit2 exit must Exclude 0.0.0.0/0 — strips it from AllowedIPs")
+		require.Contains(t, result.Exclude, tsaddr.AllIPv6(),
+			"alice viewing tag:exit2 exit must Exclude ::/0 — strips it from AllowedIPs")
+	})
+}

hscontrol/policy/v2/policy.go

@@ -20,6 +20,7 @@ import (
 	"tailscale.com/tailcfg"
 	"tailscale.com/types/views"
 	"tailscale.com/util/deephash"
+	"tailscale.com/util/multierr"
 )
 
 // ErrInvalidTagOwner is returned when a tag owner is not an Alias type.
@@ -55,6 +56,11 @@ type PolicyManager struct {
 	// Lazy map of per-node filter rules (reduced, for packet filters)
 	filterRulesMap map[types.NodeID][]tailcfg.FilterRule
 
+	// Lazy map of per-node matchers derived from UNREDUCED filter
+	// rules. Only populated on the slow path when needsPerNodeFilter
+	// is true; the fast path returns pm.matchers directly.
+	matchersForNodeMap map[types.NodeID][]matcher.Match
+
 	// needsPerNodeFilter is true when any compiled grant requires
 	// per-node work (autogroup:self or via grants).
 	needsPerNodeFilter bool
@@ -68,6 +74,91 @@ type filterAndPolicy struct {
 	Policy *Policy
 }
 
+// validateUserReferences surfaces ambiguous user@ tokens at policy load so
+// duplicate DB rows fail loudly instead of silently dropping rules (#3160).
+// Missing-user tokens stay tolerant (#2863). Empty users → no-op for
+// syntax-only checks.
+func validateUserReferences(pol *Policy, users types.Users) error {
+	if pol == nil || len(users) == 0 {
+		return nil
+	}
+
+	var errs []error
+
+	check := func(u *Username) {
+		if u == nil {
+			return
+		}
+
+		_, err := u.resolveUser(users)
+		if err != nil && errors.Is(err, ErrMultipleUsersFound) {
+			errs = append(errs, err)
+		}
+	}
+
+	checkAlias := func(a Alias) {
+		if u, ok := a.(*Username); ok {
+			check(u)
+		}
+	}
+
+	checkOwner := func(o Owner) {
+		if u, ok := o.(*Username); ok {
+			check(u)
+		}
+	}
+
+	checkAutoApprover := func(aa AutoApprover) {
+		if u, ok := aa.(*Username); ok {
+			check(u)
+		}
+	}
+
+	for _, usernames := range pol.Groups {
+		for i := range usernames {
+			check(&usernames[i])
+		}
+	}
+
+	for _, owners := range pol.TagOwners {
+		for _, o := range owners {
+			checkOwner(o)
+		}
+	}
+
+	for _, approvers := range pol.AutoApprovers.Routes {
+		for _, aa := range approvers {
+			checkAutoApprover(aa)
+		}
+	}
+
+	for _, aa := range pol.AutoApprovers.ExitNode {
+		checkAutoApprover(aa)
+	}
+
+	for _, acl := range pol.ACLs {
+		for _, src := range acl.Sources {
+			checkAlias(src)
+		}
+
+		for _, dst := range acl.Destinations {
+			checkAlias(dst.Alias)
+		}
+	}
+
+	for _, ssh := range pol.SSHs {
+		for _, src := range ssh.Sources {
+			checkAlias(src)
+		}
+
+		for _, dst := range ssh.Destinations {
+			checkAlias(dst)
+		}
+	}
+
+	return multierr.New(errs...)
+}
+
 // NewPolicyManager creates a new PolicyManager from a policy file and a list of users and nodes.
 // It returns an error if the policy file is invalid.
 // The policy manager will update the filter rules based on the users and nodes.
@@ -77,12 +168,18 @@ func NewPolicyManager(b []byte, users []types.User, nodes views.Slice[types.Node
 		return nil, fmt.Errorf("parsing policy: %w", err)
 	}
 
+	err = validateUserReferences(policy, users)
+	if err != nil {
+		return nil, fmt.Errorf("validating policy user references: %w", err)
+	}
+
 	pm := PolicyManager{
-		pol:            policy,
-		users:          users,
-		nodes:          nodes,
-		sshPolicyMap:   make(map[types.NodeID]*tailcfg.SSHPolicy, nodes.Len()),
-		filterRulesMap: make(map[types.NodeID][]tailcfg.FilterRule, nodes.Len()),
+		pol:                policy,
+		users:              users,
+		nodes:              nodes,
+		sshPolicyMap:       make(map[types.NodeID]*tailcfg.SSHPolicy, nodes.Len()),
+		filterRulesMap:     make(map[types.NodeID][]tailcfg.FilterRule, nodes.Len()),
+		matchersForNodeMap: make(map[types.NodeID][]matcher.Match, nodes.Len()),
 	}
 
 	_, err = pm.updateLocked()
@@ -103,7 +200,7 @@ func (pm *PolicyManager) updateLocked() (bool, error) {
 	pm.needsPerNodeFilter = hasPerNodeGrants(pm.compiledGrants)
 
 	var filter []tailcfg.FilterRule
-	if pm.pol == nil || (pm.pol.ACLs == nil && len(pm.pol.Grants) == 0) {
+	if pm.pol == nil || (pm.pol.ACLs == nil && pm.pol.Grants == nil) {
 		filter = tailcfg.FilterAllowAll
 	} else {
 		filter = globalFilterRules(pm.compiledGrants)
@@ -207,6 +304,7 @@ func (pm *PolicyManager) updateLocked() (bool, error) {
 		// that nodes has been added or removed.
 		clear(pm.sshPolicyMap)
 		clear(pm.filterRulesMap)
+		clear(pm.matchersForNodeMap)
 	}
 
 	// If nothing changed, no need to update nodes
@@ -227,6 +325,11 @@ func (pm *PolicyManager) updateLocked() (bool, error) {
 	return true, nil
 }
 
+// SSHPolicy returns the tailcfg.SSHPolicy for node, compiling and
+// caching on first access. Rules use SessionDuration = 0 (no
+// auto-approval) and emit check URLs of the form
+// /machine/ssh/action/{src}/to/{dst}?local_user={local_user} per the
+// SaaS wire format. Cache is invalidated on policy reload.
 func (pm *PolicyManager) SSHPolicy(baseURL string, node types.NodeView) (*tailcfg.SSHPolicy, error) {
 	pm.mu.Lock()
 	defer pm.mu.Unlock()
@@ -247,9 +350,12 @@ func (pm *PolicyManager) SSHPolicy(baseURL string, node types.NodeView) (*tailcf
 
 // SSHCheckParams resolves the SSH check period for a source-destination
 // node pair by looking up the current policy. This avoids trusting URL
-// parameters that a client could tamper with.
-// It returns the check period duration and whether a matching check
-// rule was found.
+// parameters that a client could tamper with. First-match wins across
+// the policy's SSH rules.
+//
+// Returns (duration, true) when a matching rule is found and
+// (0, false) when none is. A (0, true) return means the matched rule
+// uses a zero check period (re-check every session).
 func (pm *PolicyManager) SSHCheckParams(
 	srcNodeID, dstNodeID types.NodeID,
 ) (time.Duration, bool) {
@@ -336,6 +442,20 @@ func (pm *PolicyManager) SetPolicy(polB []byte) (bool, error) {
 	pm.mu.Lock()
 	defer pm.mu.Unlock()
 
+	err = validateUserReferences(pol, pm.users)
+	if err != nil {
+		return false, fmt.Errorf("validating policy user references: %w", err)
+	}
+
+	// SetPolicy is the user-write boundary. Tests evaluate against a
+	// sandbox compiled from the new policy + current users/nodes; if
+	// they fail, return without mutating the live PolicyManager so the
+	// failed write does not knock the running config offline.
+	err = evaluateTests(pol, pm.users, pm.nodes)
+	if err != nil {
+		return false, err
+	}
+
 	// Log policy metadata for debugging
 	log.Debug().
 		Int("policy.bytes", len(polB)).
@@ -344,6 +464,7 @@ func (pm *PolicyManager) SetPolicy(polB []byte) (bool, error) {
 		Int("hosts.count", len(pol.Hosts)).
 		Int("tagOwners.count", len(pol.TagOwners)).
 		Int("autoApprovers.routes.count", len(pol.AutoApprovers.Routes)).
+		Int("tests.count", len(pol.Tests)).
 		Msg("Policy parsed successfully")
 
 	pm.pol = pol
@@ -502,6 +623,9 @@ func (pm *PolicyManager) filterForNodeLocked(
 // to only include rules relevant to that node.
 // If the policy uses autogroup:self, this returns node-specific compiled rules.
 // Otherwise, it returns the global filter reduced for this node.
+//
+// Cache is invalidated by updateLocked on policy reload, node-set
+// change, or tag-state change.
 func (pm *PolicyManager) FilterForNode(node types.NodeView) ([]tailcfg.FilterRule, error) {
 	if pm == nil {
 		return nil, nil
@@ -519,6 +643,10 @@ func (pm *PolicyManager) FilterForNode(node types.NodeView) ([]tailcfg.FilterRul
 //
 // For global policies: returns the global matchers (same for all nodes)
 // For autogroup:self: returns node-specific matchers from unreduced compiled rules.
+//
+// Per-node results are cached and invalidated on policy/node updates
+// so BuildPeerMap's O(N²) slow path avoids recomputing matchers for
+// every pair.
 func (pm *PolicyManager) MatchersForNode(node types.NodeView) ([]matcher.Match, error) {
 	if pm == nil {
 		return nil, nil
@@ -534,11 +662,17 @@ func (pm *PolicyManager) MatchersForNode(node types.NodeView) ([]matcher.Match,
 		return pm.matchers, nil
 	}
 
+	if cached, ok := pm.matchersForNodeMap[node.ID()]; ok {
+		return cached, nil
+	}
+
 	// For autogroup:self or via grants, derive matchers from
 	// the stored compiled grants for this specific node.
 	unreduced := pm.filterRulesForNodeLocked(node)
+	matchers := matcher.MatchesFromFilterRules(unreduced)
+	pm.matchersForNodeMap[node.ID()] = matchers
 
-	return matcher.MatchesFromFilterRules(unreduced), nil
+	return matchers, nil
 }
 
 // SetUsers updates the users in the policy manager and updates the filter rules.
@@ -610,6 +744,7 @@ func (pm *PolicyManager) SetNodes(nodes views.Slice[types.NodeView]) (bool, erro
 			// This ensures fresh filter rules are generated for all nodes
 			clear(pm.sshPolicyMap)
 			clear(pm.filterRulesMap)
+			clear(pm.matchersForNodeMap)
 		}
 		// Always return true when nodes changed, even if filter hash didn't change
 		// (can happen with autogroup:self or when nodes are added but don't affect rules)
@@ -758,6 +893,9 @@ func (pm *PolicyManager) NodeCanApproveRoute(node types.NodeView, route netip.Pr
 		return false
 	}
 
+	pm.mu.Lock()
+	defer pm.mu.Unlock()
+
 	// If the route to-be-approved is an exit route, then we need to check
 	// if the node is in allowed to approve it. This is treated differently
 	// than the auto-approvers, as the auto-approvers are not allowed to
@@ -769,16 +907,9 @@ func (pm *PolicyManager) NodeCanApproveRoute(node types.NodeView, route netip.Pr
 			return false
 		}
 
-		if slices.ContainsFunc(node.IPs(), pm.exitSet.Contains) {
-			return true
-		}
-
-		return false
+		return slices.ContainsFunc(node.IPs(), pm.exitSet.Contains)
 	}
 
-	pm.mu.Lock()
-	defer pm.mu.Unlock()
-
 	// The fast path is that a node requests to approve a prefix
 	// where there is an exact entry, e.g. 10.0.0.0/8, then
 	// check and return quickly
@@ -811,6 +942,10 @@ func (pm *PolicyManager) NodeCanApproveRoute(node types.NodeView, route netip.Pr
 // For each via grant where the viewer matches the source, it checks whether the
 // peer advertises any of the grant's destination prefixes. If the peer has the
 // via tag, those prefixes go into Include; otherwise into Exclude.
+//
+// Performance note: this holds pm.mu for its full duration. Hot
+// callers should memoise by (policy-hash, viewer-id) rather than
+// invoking this per-pair.
 func (pm *PolicyManager) ViaRoutesForPeer(viewer, peer types.NodeView) types.ViaRouteResult {
 	var result types.ViaRouteResult
 
@@ -831,28 +966,33 @@ func (pm *PolicyManager) ViaRoutesForPeer(viewer, peer types.NodeView) types.Via
 		grants = append(grants, aclToGrants(acl)...)
 	}
 
-	for _, grant := range grants {
-		if len(grant.Via) == 0 {
-			continue
-		}
-
-		// Check if viewer matches any grant source.
-		viewerMatches := false
+	// Resolve each grant's sources against the viewer once. The three
+	// passes below reuse this result instead of calling src.Resolve
+	// per grant per pass.
+	viewerIPs := viewer.IPs()
+	viewerMatchesGrant := make([]bool, len(grants))
 
+	for i, grant := range grants {
 		for _, src := range grant.Sources {
 			ips, err := src.Resolve(pm.pol, pm.users, pm.nodes)
 			if err != nil {
 				continue
 			}
 
-			if ips != nil && slices.ContainsFunc(viewer.IPs(), ips.Contains) {
-				viewerMatches = true
+			if ips != nil && slices.ContainsFunc(viewerIPs, ips.Contains) {
+				viewerMatchesGrant[i] = true
 
 				break
 			}
 		}
+	}
 
-		if !viewerMatches {
+	for i, grant := range grants {
+		if len(grant.Via) == 0 {
+			continue
+		}
+
+		if !viewerMatchesGrant[i] {
 			continue
 		}
 
@@ -869,11 +1009,16 @@ func (pm *PolicyManager) ViaRoutesForPeer(viewer, peer types.NodeView) types.Via
 					matchedPrefixes = append(matchedPrefixes, dstPrefix)
 				}
 			case *AutoGroup:
-				// autogroup:internet via grants do NOT affect AllowedIPs or
-				// route steering for exit nodes. Tailscale SaaS handles exit
-				// traffic forwarding through the client's exit node selection
-				// mechanism, not through AllowedIPs. Verified by golden
-				// captures GRANT-V14 through GRANT-V36.
+				// Per-viewer steering for autogroup:internet: a peer
+				// advertising approved exit routes is the via-tagged
+				// node's analogue of "advertises the destination".
+				// The downstream Include/Exclude split below restricts
+				// alice to exit nodes carrying the via tag.
+				if d.Is(AutoGroupInternet) && peer.IsExitNode() {
+					matchedPrefixes = append(
+						matchedPrefixes, peer.ExitRoutes()...,
+					)
+				}
 			}
 		}
 
@@ -899,6 +1044,113 @@ func (pm *PolicyManager) ViaRoutesForPeer(viewer, peer types.NodeView) types.Via
 		}
 	}
 
+	// Detect prefixes that should fall back to HA primary election
+	// rather than per-viewer via steering. Two conditions trigger this:
+	//
+	// 1. Multi-router via: a via grant's tag matches multiple peers
+	//    advertising the same prefix.
+	// 2. Regular grant overlap: a non-via grant also covers the same
+	//    prefix for this viewer.
+	//
+	// When neither condition is met, per-viewer via steering applies.
+	if len(result.Include) > 0 || len(result.Exclude) > 0 {
+		// Multi-router via election: when a via grant's tag matches
+		// multiple peers advertising the same prefix, only the
+		// lowest-ID peer (the via-group primary) keeps the prefix in
+		// Include. The others move to Exclude. This mirrors HA
+		// primary election scoped to the via tag group.
+		//
+		// Unlike the global PrimaryRoutes election (routes/primary.go),
+		// which picks one primary across ALL advertisers of a prefix,
+		// this election is scoped to the via tag. Two via grants with
+		// different tags (e.g., tag:ha-a vs tag:ha-b) each elect their
+		// own winner independently.
+		//
+		// Only process via grants where the viewer matches the source,
+		// otherwise grants for other viewer groups would incorrectly
+		// demote the peer.
+		for i, grant := range grants {
+			if len(grant.Via) == 0 {
+				continue
+			}
+
+			if !viewerMatchesGrant[i] {
+				continue
+			}
+
+			for _, dst := range grant.Destinations {
+				d, ok := dst.(*Prefix)
+				if !ok {
+					continue
+				}
+
+				dstPrefix := netip.Prefix(*d)
+				if !slices.Contains(result.Include, dstPrefix) {
+					continue
+				}
+
+				// Find the lowest-ID peer with this via tag that
+				// advertises this prefix — the via-group primary.
+				var viaPrimaryID types.NodeID
+
+				for _, viaTag := range grant.Via {
+					for _, node := range pm.nodes.All() {
+						if node.HasTag(string(viaTag)) &&
+							slices.Contains(node.SubnetRoutes(), dstPrefix) {
+							if viaPrimaryID == 0 || node.ID() < viaPrimaryID {
+								viaPrimaryID = node.ID()
+							}
+						}
+					}
+				}
+
+				// If the current peer is not the via-group primary,
+				// demote the prefix from Include to Exclude.
+				if viaPrimaryID != 0 && peer.ID() != viaPrimaryID {
+					result.Include = slices.DeleteFunc(result.Include, func(p netip.Prefix) bool {
+						return p == dstPrefix
+					})
+					if !slices.Contains(result.Exclude, dstPrefix) {
+						result.Exclude = append(result.Exclude, dstPrefix)
+					}
+				}
+			}
+		}
+
+		// Check for regular (non-via) grants covering the same prefix.
+		// When a regular grant also covers a prefix that a via grant
+		// included, defer to global HA primary election (UsePrimary).
+		// When a regular grant covers a prefix that a via grant excluded
+		// (peer lacks via tag), remove the exclusion so RoutesForPeer
+		// can apply normal ReduceRoutes + primary logic.
+		for i, grant := range grants {
+			if len(grant.Via) > 0 {
+				continue
+			}
+
+			if !viewerMatchesGrant[i] {
+				continue
+			}
+
+			for _, dst := range grant.Destinations {
+				if d, ok := dst.(*Prefix); ok {
+					dstPrefix := netip.Prefix(*d)
+					if slices.Contains(result.Include, dstPrefix) &&
+						!slices.Contains(result.UsePrimary, dstPrefix) {
+						result.UsePrimary = append(result.UsePrimary, dstPrefix)
+					}
+
+					// A regular grant overrides a via exclusion: the
+					// peer doesn't need the via tag if the viewer has
+					// direct (non-via) access to the prefix.
+					result.Exclude = slices.DeleteFunc(result.Exclude, func(p netip.Prefix) bool {
+						return p == dstPrefix
+					})
+				}
+			}
+		}
+	}
+
 	return result
 }
 
@@ -1111,10 +1363,12 @@ func (pm *PolicyManager) invalidateAutogroupSelfCache(oldNodes, newNodes views.S
 		if found {
 			if _, affected := affectedUsers[nodeUserID]; affected {
 				delete(pm.filterRulesMap, nodeID)
+				delete(pm.matchersForNodeMap, nodeID)
 			}
 		} else {
 			// Node not found in either old or new list, clear it
 			delete(pm.filterRulesMap, nodeID)
+			delete(pm.matchersForNodeMap, nodeID)
 		}
 	}
 
@@ -1163,6 +1417,7 @@ func (pm *PolicyManager) invalidateGlobalPolicyCache(newNodes views.Slice[types.
 
 		if newNode.HasNetworkChanges(oldNode) {
 			delete(pm.filterRulesMap, nodeID)
+			delete(pm.matchersForNodeMap, nodeID)
 		}
 	}
 
@@ -1172,6 +1427,12 @@ func (pm *PolicyManager) invalidateGlobalPolicyCache(newNodes views.Slice[types.
 			delete(pm.filterRulesMap, nodeID)
 		}
 	}
+
+	for nodeID := range pm.matchersForNodeMap {
+		if _, exists := newNodeMap[nodeID]; !exists {
+			delete(pm.matchersForNodeMap, nodeID)
+		}
+	}
 }
 
 // flattenTags flattens the TagOwners by resolving nested tags and detecting cycles.

hscontrol/policy/v2/policy_test.go

@@ -10,6 +10,7 @@ import (
 	"github.com/juanfont/headscale/hscontrol/types"
 	"github.com/stretchr/testify/require"
 	"gorm.io/gorm"
+	"tailscale.com/net/tsaddr"
 	"tailscale.com/tailcfg"
 )
 
@@ -44,6 +45,20 @@ func TestPolicyManager(t *testing.T) {
 			wantFilter:   tailcfg.FilterAllowAll,
 			wantMatchers: matcher.MatchesFromFilterRules(tailcfg.FilterAllowAll),
 		},
+		{
+			name:         "empty-acls-denies-all",
+			pol:          `{"acls": []}`,
+			nodes:        types.Nodes{},
+			wantFilter:   nil,
+			wantMatchers: matcher.MatchesFromFilterRules(nil),
+		},
+		{
+			name:         "empty-grants-denies-all",
+			pol:          `{"grants": []}`,
+			nodes:        types.Nodes{},
+			wantFilter:   nil,
+			wantMatchers: matcher.MatchesFromFilterRules(nil),
+		},
 	}
 
 	for _, tt := range tests {
@@ -1625,10 +1640,14 @@ func TestViaRoutesForPeer(t *testing.T) {
 		require.NoError(t, err)
 
 		result := pm.ViaRoutesForPeer(nodes[0].View(), nodes[1].View())
-		// Include should have only the subnet route.
-		// autogroup:internet does not produce via route effects.
+		// Include contains the subnet route plus the peer's approved
+		// exit routes — the peer holds tag:router and advertises exit
+		// routes, so autogroup:internet steering applies alongside the
+		// explicit prefix.
 		require.Contains(t, result.Include, mp("10.0.0.0/24"))
-		require.Len(t, result.Include, 1)
+		require.Contains(t, result.Include, mp("0.0.0.0/0"))
+		require.Contains(t, result.Include, mp("::/0"))
+		require.Len(t, result.Include, 3)
 		require.Empty(t, result.Exclude)
 	})
 
@@ -1698,17 +1717,20 @@ func TestViaRoutesForPeer(t *testing.T) {
 		pm, err := NewPolicyManager([]byte(pol), users, nodes.ViewSlice())
 		require.NoError(t, err)
 
-		// autogroup:internet via grants do NOT affect AllowedIPs or
-		// route steering. Tailscale SaaS handles exit traffic through
-		// the client's exit node mechanism, not ViaRoutesForPeer.
-		// Verified by golden captures GRANT-V14 through GRANT-V36.
+		// autogroup:internet via grants surface the peer's approved
+		// exit routes when the peer carries the via tag, and exclude
+		// them when it does not — restricting which exit nodes the
+		// viewer may use, per Tailscale's grants-via spec for
+		// autogroup:internet.
 		resultExit := pm.ViaRoutesForPeer(nodes[0].View(), nodes[1].View())
-		require.Empty(t, resultExit.Include)
+		require.Contains(t, resultExit.Include, mp("0.0.0.0/0"))
+		require.Contains(t, resultExit.Include, mp("::/0"))
 		require.Empty(t, resultExit.Exclude)
 
 		resultOther := pm.ViaRoutesForPeer(nodes[0].View(), nodes[2].View())
 		require.Empty(t, resultOther.Include)
-		require.Empty(t, resultOther.Exclude)
+		require.Contains(t, resultOther.Exclude, mp("0.0.0.0/0"))
+		require.Contains(t, resultOther.Exclude, mp("::/0"))
 	})
 
 	t.Run("via_routes_survive_reduce_routes", func(t *testing.T) {
@@ -1792,3 +1814,211 @@ func TestViaRoutesForPeer(t *testing.T) {
 				"state.RoutesForPeer adds via routes after ReduceRoutes to fix this")
 	})
 }
+
+// TestBuildPeerMap_AutogroupInternetMakesExitNodeVisible reproduces
+// juanfont/headscale#3212. An ACL that grants access only via
+// `autogroup:internet` must keep the exit node visible to the source
+// in BuildPeerMap so the Tailscale client surfaces it in
+// `tailscale exit-node list`. Authoritative SaaS captures
+// (tscap routes-b17/b18, 2026-04-28) confirm SaaS includes the exit
+// node in the source's Peers with 0.0.0.0/0 and ::/0 in AllowedIPs.
+func TestBuildPeerMap_AutogroupInternetMakesExitNodeVisible(t *testing.T) {
+	t.Parallel()
+
+	users := types.Users{
+		{Model: gorm.Model{ID: 1}, Name: "alice", Email: "alice@headscale.net"},
+	}
+
+	aliceNode := node("alice-laptop", "100.64.0.10", "fd7a:115c:a1e0::a", users[0])
+	aliceNode.ID = 1
+
+	exitRoutes := []netip.Prefix{tsaddr.AllIPv4(), tsaddr.AllIPv6()}
+	exitNode := node("alice-exit", "100.64.0.1", "fd7a:115c:a1e0::1", users[0])
+	exitNode.ID = 2
+	exitNode.Hostinfo = &tailcfg.Hostinfo{RoutableIPs: exitRoutes}
+	exitNode.ApprovedRoutes = exitRoutes
+
+	nodes := types.Nodes{aliceNode, exitNode}
+
+	policy := `{
+		"acls": [
+			{"action": "accept", "src": ["alice@headscale.net"], "dst": ["autogroup:internet:*"]}
+		]
+	}`
+
+	pm, err := NewPolicyManager([]byte(policy), users, nodes.ViewSlice())
+	require.NoError(t, err)
+
+	peerMap := pm.BuildPeerMap(nodes.ViewSlice())
+
+	require.True(t,
+		slices.ContainsFunc(peerMap[aliceNode.ID], func(n types.NodeView) bool {
+			return n.ID() == exitNode.ID
+		}),
+		"alice should see the exit node as a peer when an ACL grants autogroup:internet (#3212)")
+
+	_, matchers := pm.Filter()
+	require.True(t, aliceNode.View().CanAccess(matchers, exitNode.View()),
+		"alice.CanAccess(exit) should be true via DestsIsTheInternet()+IsExitNode() (#3212)")
+}
+
+// Reproduction for #3160: ambiguous user@ used to silently drop rules.
+func TestNewPolicyManager_DuplicateUsername(t *testing.T) {
+	users := types.Users{
+		{Model: gorm.Model{ID: 2}, Name: "yala"},
+		{Model: gorm.Model{ID: 7}, Name: "yala", Email: "yala@yala.yala"},
+	}
+
+	polB := []byte(`{
+  "groups":    {"group:admins": ["yala@"]},
+  "tagOwners": {"tag:ssh": ["group:admins"]},
+  "acls":      [{"action":"accept","src":["*"],"dst":["*:*"]}],
+  "ssh": [
+    {"action":"accept","src":["group:admins"],"dst":["tag:ssh"],"users":["root"]}
+  ]
+}`)
+
+	_, err := NewPolicyManager(polB, users, types.Nodes{}.ViewSlice())
+	require.Error(t, err, "NewPolicyManager must reject policy with ambiguous username")
+	require.ErrorIs(t, err, ErrMultipleUsersFound)
+	require.Contains(t, err.Error(), "yala@",
+		"error must name the offending token")
+}
+
+// Missing-user tokens stay tolerant per #2863; only multi-match blocks load.
+func TestNewPolicyManager_UnknownUsernameTolerant(t *testing.T) {
+	users := types.Users{
+		{Model: gorm.Model{ID: 1}, Name: "alice"},
+	}
+
+	polB := []byte(`{
+  "acls": [{"action":"accept","src":["ghost@"],"dst":["*:*"]}]
+}`)
+
+	_, err := NewPolicyManager(polB, users, types.Nodes{}.ViewSlice())
+	require.NoError(t, err, "missing-user references must not block policy load (#2863)")
+}
+
+// Rejected SetPolicy must keep the previous policy intact.
+func TestSetPolicy_DuplicateUsername(t *testing.T) {
+	users := types.Users{
+		{Model: gorm.Model{ID: 2}, Name: "yala"},
+		{Model: gorm.Model{ID: 7}, Name: "yala", Email: "yala@yala.yala"},
+	}
+
+	good := []byte(`{
+  "acls": [{"action":"accept","src":["*"],"dst":["*:*"]}]
+}`)
+
+	pm, err := NewPolicyManager(good, users, types.Nodes{}.ViewSlice())
+	require.NoError(t, err)
+
+	bad := []byte(`{
+  "groups": {"group:admins": ["yala@"]},
+  "acls":   [{"action":"accept","src":["group:admins"],"dst":["*:*"]}]
+}`)
+
+	_, err = pm.SetPolicy(bad)
+	require.Error(t, err)
+	require.ErrorIs(t, err, ErrMultipleUsersFound)
+
+	filter, _ := pm.Filter()
+	require.NotNil(t, filter, "filter must remain populated after rejected SetPolicy")
+}
+
+// Empty users → syntax-only check, used by `headscale policy check`.
+func TestValidateUserReferences_EmptyUsersTolerant(t *testing.T) {
+	polB := []byte(`{
+  "groups":    {"group:admins": ["yala@"]},
+  "tagOwners": {"tag:ssh": ["group:admins"]},
+  "acls":      [{"action":"accept","src":["yala@"],"dst":["*:*"]}],
+  "ssh": [
+    {"action":"accept","src":["yala@"],"dst":["tag:ssh"],"users":["root"]}
+  ]
+}`)
+
+	_, err := NewPolicyManager(polB, nil, types.Nodes{}.ViewSlice())
+	require.NoError(t, err, "nil users must skip user-reference validation")
+
+	_, err = NewPolicyManager(polB, types.Users{}, types.Nodes{}.ViewSlice())
+	require.NoError(t, err, "empty users must skip user-reference validation")
+}
+
+// One case per AST site so a dropped walk fails the matching subtest.
+func TestValidateUserReferences_AllSites(t *testing.T) {
+	users := types.Users{
+		{Model: gorm.Model{ID: 1}, Name: "alice"},
+		{Model: gorm.Model{ID: 2}, Name: "dup"},
+		{Model: gorm.Model{ID: 3}, Name: "dup"},
+	}
+
+	tests := []struct {
+		name string
+		pol  string
+	}{
+		{
+			name: "groups",
+			pol: `{
+  "groups": {"group:admins": ["dup@"]},
+  "acls":   [{"action":"accept","src":["group:admins"],"dst":["*:*"]}]
+}`,
+		},
+		{
+			name: "tagOwners",
+			pol: `{
+  "tagOwners": {"tag:ssh": ["dup@"]},
+  "acls":      [{"action":"accept","src":["*"],"dst":["*:*"]}]
+}`,
+		},
+		{
+			name: "autoApprovers.routes",
+			pol: `{
+  "autoApprovers": {"routes": {"10.0.0.0/8": ["dup@"]}},
+  "acls":          [{"action":"accept","src":["*"],"dst":["*:*"]}]
+}`,
+		},
+		{
+			name: "autoApprovers.exitNode",
+			pol: `{
+  "autoApprovers": {"exitNode": ["dup@"]},
+  "acls":          [{"action":"accept","src":["*"],"dst":["*:*"]}]
+}`,
+		},
+		{
+			name: "acls.src",
+			pol: `{
+  "acls": [{"action":"accept","src":["dup@"],"dst":["*:*"]}]
+}`,
+		},
+		{
+			name: "acls.dst",
+			pol: `{
+  "acls": [{"action":"accept","src":["alice@"],"dst":["dup@:*"]}]
+}`,
+		},
+		{
+			name: "ssh.src",
+			pol: `{
+  "tagOwners": {"tag:ssh": ["alice@"]},
+  "acls":      [{"action":"accept","src":["*"],"dst":["*:*"]}],
+  "ssh": [{"action":"accept","src":["dup@"],"dst":["tag:ssh"],"users":["root"]}]
+}`,
+		},
+		{
+			// ErrSSHUserDestRequiresSameUser forces src==dst when dst is a user.
+			name: "ssh.dst",
+			pol: `{
+  "acls": [{"action":"accept","src":["*"],"dst":["*:*"]}],
+  "ssh": [{"action":"accept","src":["dup@"],"dst":["dup@"],"users":["root"]}]
+}`,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			_, err := NewPolicyManager([]byte(tt.pol), users, types.Nodes{}.ViewSlice())
+			require.Error(t, err, "site %q must surface duplicate-user errors", tt.name)
+			require.ErrorIs(t, err, ErrMultipleUsersFound)
+		})
+	}
+}

hscontrol/policy/v2/policytester_compat_test.go

@@ -0,0 +1,170 @@
+// Compatibility tests for the policy `tests` block, replaying captures
+// recorded against a real Tailscale SaaS tailnet. The runner mirrors the
+// pattern in tailscale_grants_compat_test.go: a single Glob over a
+// testdata directory, one t.Run per file. Each capture is one of:
+//
+//   - APIResponseCode != 200 — the policy was rejected by the SaaS, the
+//     captured Message is the byte-exact body the user saw, and headscale
+//     must reject the same input with an error string that contains the
+//     same body (substring match, allowing wrapping like "test(s)
+//     failed:\n…").
+//   - APIResponseCode == 200 — the SaaS accepted the policy (its `tests`
+//     block passed); headscale's RunTests must also pass.
+//
+// Captures live in testdata/policytest_results/*.hujson. Scenarios in
+// knownPolicyTesterDivergences are skipped with their tracking note —
+// these are real Tailscale ↔ headscale divergences uncovered by the
+// captures that need engine-level fixes in follow-up PRs.
+//
+// Source format: github.com/juanfont/headscale/hscontrol/types/testcapture
+
+package v2
+
+import (
+	"path/filepath"
+	"strings"
+	"testing"
+
+	"github.com/juanfont/headscale/hscontrol/types"
+	"github.com/juanfont/headscale/hscontrol/types/testcapture"
+	"github.com/stretchr/testify/require"
+	"gorm.io/gorm"
+	"tailscale.com/tailcfg"
+)
+
+// knownPolicyTesterDivergences lists scenarios where headscale's evaluator
+// disagrees with Tailscale SaaS on whether the policy should be accepted.
+// Each entry is a real bug to fix in a follow-up; documenting them here
+// keeps the compat suite green and the divergence list visible.
+var knownPolicyTesterDivergences = map[string]string{} //nolint:gosec // strings here are human-readable notes, not credentials
+
+// policyTesterCompatUsers / policyTesterCompatNodes mirror the small
+// shared topology used to record the captures. When more captures land
+// we'll also exercise an autogroup-heavy second topology — for now this
+// minimal one is enough to make the runner go.
+func policyTesterCompatUsers() types.Users {
+	return types.Users{
+		{Model: gorm.Model{ID: 1}, Name: "odin", Email: "odin@example.com"},
+		{Model: gorm.Model{ID: 2}, Name: "thor", Email: "thor@example.org"},
+		{Model: gorm.Model{ID: 3}, Name: "freya", Email: "freya@example.com"},
+	}
+}
+
+func policyTesterCompatNodes(users types.Users) types.Nodes {
+	return types.Nodes{
+		{
+			ID:        1,
+			GivenName: "bulbasaur",
+			User:      &users[0],
+			UserID:    &users[0].ID,
+			IPv4:      ptrAddr("100.90.199.68"),
+			IPv6:      ptrAddr("fd7a:115c:a1e0::2d01:c747"),
+			Hostinfo:  &tailcfg.Hostinfo{},
+		},
+		{
+			ID:        2,
+			GivenName: "ivysaur",
+			User:      &users[1],
+			UserID:    &users[1].ID,
+			IPv4:      ptrAddr("100.110.121.96"),
+			IPv6:      ptrAddr("fd7a:115c:a1e0::1737:7960"),
+			Hostinfo:  &tailcfg.Hostinfo{},
+		},
+		{
+			ID:        3,
+			GivenName: "venusaur",
+			User:      &users[2],
+			UserID:    &users[2].ID,
+			IPv4:      ptrAddr("100.103.90.82"),
+			IPv6:      ptrAddr("fd7a:115c:a1e0::9e37:5a52"),
+			Hostinfo:  &tailcfg.Hostinfo{},
+		},
+		{
+			ID:        4,
+			GivenName: "beedrill",
+			IPv4:      ptrAddr("100.108.74.26"),
+			IPv6:      ptrAddr("fd7a:115c:a1e0::b901:4a87"),
+			Tags:      []string{"tag:server"},
+			Hostinfo:  &tailcfg.Hostinfo{},
+		},
+		{
+			ID:        5,
+			GivenName: "kakuna",
+			IPv4:      ptrAddr("100.103.8.15"),
+			IPv6:      ptrAddr("fd7a:115c:a1e0::5b37:80f"),
+			Tags:      []string{"tag:client"},
+			Hostinfo:  &tailcfg.Hostinfo{},
+		},
+	}
+}
+
+// TestPolicyTesterCompat replays every capture under
+// testdata/policytest_results/ against the engine. With no captures the
+// test is a no-op — committed early so the layout/wiring lands before
+// the bulk import.
+func TestPolicyTesterCompat(t *testing.T) {
+	t.Parallel()
+
+	files, err := filepath.Glob(filepath.Join("testdata", "policytest_results", "*.hujson"))
+	require.NoError(t, err, "failed to glob test files")
+
+	if len(files) == 0 {
+		t.Skip("no policytest captures yet")
+	}
+
+	users := policyTesterCompatUsers()
+	nodes := policyTesterCompatNodes(users)
+
+	for _, file := range files {
+		c, err := testcapture.Read(file)
+		require.NoError(t, err, "reading %s", file)
+
+		t.Run(c.TestID, func(t *testing.T) {
+			t.Parallel()
+
+			if reason, skip := knownPolicyTesterDivergences[c.TestID]; skip {
+				t.Skip(reason)
+			}
+
+			policyJSON := []byte(c.Input.FullPolicy)
+
+			pm, parseErr := NewPolicyManager(policyJSON, users, nodes.ViewSlice())
+
+			// Tailscale validates and runs tests as one POST step:
+			// either failure mode produces the same 400. Headscale
+			// splits structural validation (parse) from test
+			// evaluation (SetPolicy). For the compat assertion, the
+			// two are equivalent — whichever surfaces first carries
+			// the captured body.
+			if c.Input.APIResponseCode == 200 {
+				require.NoError(t, parseErr, "tailscale accepted this policy; headscale must parse it")
+
+				_, setErr := pm.SetPolicy(policyJSON)
+				require.NoError(t, setErr, "tailscale accepted this policy; headscale tests should pass")
+
+				return
+			}
+
+			var got error
+
+			switch {
+			case parseErr != nil:
+				got = parseErr
+			default:
+				_, setErr := pm.SetPolicy(policyJSON)
+				got = setErr
+			}
+
+			require.Error(t, got, "tailscale rejected; headscale must reject too")
+
+			if c.Input.APIResponseBody == nil || c.Input.APIResponseBody.Message == "" {
+				return
+			}
+
+			want := c.Input.APIResponseBody.Message
+			if !strings.Contains(got.Error(), want) {
+				t.Errorf("error body mismatch\n  tailscale wants: %q\n  headscale got:   %q", want, got.Error())
+			}
+		})
+	}
+}

hscontrol/policy/v2/tailscale_acl_data_compat_test.go

@@ -16,6 +16,7 @@ package v2
 
 import (
 	"encoding/json"
+	"fmt"
 	"net/netip"
 	"path/filepath"
 	"strings"
@@ -141,18 +142,20 @@ func cmpOptions() []cmp.Option {
 			return a.Bits() < b.Bits()
 		}),
 		// Compare tailcfg.RawMessage semantically (it's a string type
-		// containing JSON) to handle indentation differences.
+		// containing JSON) to handle indentation differences. Both
+		// sides must be valid JSON — golden data parse failures are
+		// always errors.
 		cmp.Comparer(func(a, b tailcfg.RawMessage) bool {
 			var va, vb any
 
 			err := json.Unmarshal([]byte(a), &va)
 			if err != nil {
-				return a == b
+				panic(fmt.Sprintf("golden RawMessage A unparseable: %v", err))
 			}
 
 			err = json.Unmarshal([]byte(b), &vb)
 			if err != nil {
-				return a == b
+				panic(fmt.Sprintf("golden RawMessage B unparseable: %v", err))
 			}
 
 			ja, _ := json.Marshal(va)
@@ -163,7 +166,6 @@ func cmpOptions() []cmp.Option {
 	}
 }
 
-
 // buildACLUsersAndNodes constructs users and nodes from an ACL
 // golden file's topology. This ensures the test creates the same
 // nodes that were present during the Tailscale SaaS capture.
@@ -254,22 +256,6 @@ func loadACLTestFile(t *testing.T, path string) *testcapture.Capture {
 	return c
 }
 
-// aclSkipReasons documents WHY tests are expected to fail and WHAT needs to be
-// implemented to fix them. Tests are grouped by root cause.
-//
-// Impact summary:
-//
-//	SRCIPS_FORMAT            - tests: SrcIPs use adapted format (100.64.0.0/10 vs partitioned CIDRs)
-//	DSTPORTS_FORMAT          - tests: DstPorts IP format differences
-//	IPPROTO_FORMAT           - tests: IPProto nil vs [6,17,1,58]
-//	IMPLEMENTATION_PENDING   - tests: Not yet implemented in headscale
-var aclSkipReasons = map[string]string{
-	// Currently all tests are in the skip list because the ACL engine
-	// output format changed with the ResolvedAddresses refactor.
-	// Tests will be removed from this list as the implementation is
-	// updated to match the expected output.
-}
-
 // TestACLCompat is a data-driven test that loads all ACL-*.json test files
 // and compares headscale's ACL engine output against the expected behavior.
 //
@@ -298,16 +284,6 @@ func TestACLCompat(t *testing.T) {
 		t.Run(tf.TestID, func(t *testing.T) {
 			t.Parallel()
 
-			// Check skip list
-			if reason, ok := aclSkipReasons[tf.TestID]; ok {
-				t.Skipf(
-					"TODO: %s — see aclSkipReasons for details",
-					reason,
-				)
-
-				return
-			}
-
 			if tf.Error {
 				testACLError(t, tf)
 
@@ -326,13 +302,6 @@ func TestACLCompat(t *testing.T) {
 	}
 }
 
-// aclErrorMessageMap maps Tailscale SaaS error substrings to headscale
-// equivalents. Populated as mismatches are discovered.
-var aclErrorMessageMap = map[string]string{
-	// Add known wording differences here as they are discovered.
-	// Example: "tag not found" -> "undefined tag",
-}
-
 // testACLError verifies that an invalid policy produces the expected error.
 func testACLError(t *testing.T, tf *testcapture.Capture) {
 	t.Helper()
@@ -374,12 +343,9 @@ func testACLError(t *testing.T, tf *testcapture.Capture) {
 	)
 }
 
-// assertACLErrorContains checks that an error message matches the
-// expected Tailscale SaaS message, using progressive fallbacks:
-//  1. Direct substring match
-//  2. Mapped equivalent from aclErrorMessageMap
-//  3. Key-part extraction (tags, autogroups, port, undefined)
-//  4. t.Errorf on no match (strict)
+// assertACLErrorContains requires that headscale's error contains the
+// Tailscale SaaS error message exactly. Divergence means an emitter
+// needs to be aligned, not papered over with a translation table.
 func assertACLErrorContains(
 	t *testing.T,
 	err error,
@@ -389,37 +355,10 @@ func assertACLErrorContains(
 	t.Helper()
 
 	errStr := err.Error()
-
-	// 1. Direct substring match.
 	if strings.Contains(errStr, wantMsg) {
 		return
 	}
 
-	// 2. Mapped equivalent.
-	for tsKey, hsKey := range aclErrorMessageMap {
-		if strings.Contains(wantMsg, tsKey) &&
-			strings.Contains(errStr, hsKey) {
-			return
-		}
-	}
-
-	// 3. Key-part extraction.
-	for _, part := range []string{
-		"autogroup:self",
-		"not valid on the src",
-		"port range",
-		"tag not found",
-		"tag:",
-		"undefined",
-		"capability",
-	} {
-		if strings.Contains(wantMsg, part) &&
-			strings.Contains(errStr, part) {
-			return
-		}
-	}
-
-	// 4. No match — strict failure.
 	t.Errorf(
 		"%s: error message mismatch\n"+
 			"  want (tailscale): %q\n"+

hscontrol/policy/v2/tailscale_grants_compat_test.go

@@ -409,7 +409,7 @@ func TestGrantsCompat(t *testing.T) {
 			// different node IPs.
 			nodes := buildGrantsNodesFromCapture(users, tf)
 
-			// Use the captured full policy verbatim (anonymization
+			// Use the captured full policy as is (anonymization
 			// in tscap already rewrote SaaS emails).
 			policyJSON := convertPolicyUserEmails(tf.Input.FullPolicy)
 
@@ -456,85 +456,22 @@ func testGrantError(t *testing.T, policyJSON []byte, tf *testcapture.Capture) {
 		tf.TestID, wantMsg)
 }
 
-// grantErrorMessageMap maps Tailscale error messages to their headscale equivalents
-// where the wording differs but the meaning is the same.
-var grantErrorMessageMap = map[string]string{
-	// Tailscale says "ip and app can not both be empty",
-	// headscale says "grants must specify either 'ip' or 'app' field"
-	"ip and app can not both be empty": "grants must specify either",
-	// Tailscale says "via can only be a tag",
-	// headscale rejects at unmarshal time via Tag.UnmarshalJSON: "tag must start with 'tag:'"
-	"via can only be a tag": "tag must start with",
-}
-
-// assertGrantErrorContains checks that an error message contains the expected
-// Tailscale error message (or its headscale equivalent).
+// assertGrantErrorContains requires that headscale's error contains
+// the Tailscale SaaS error message exactly. Divergence means an
+// emitter needs to be aligned, not papered over with a translation
+// table.
 func assertGrantErrorContains(t *testing.T, err error, wantMsg string, testID string) {
 	t.Helper()
 
 	errStr := err.Error()
-
-	// First try direct substring match
 	if strings.Contains(errStr, wantMsg) {
 		return
 	}
 
-	// Try mapped equivalent
-	if mapped, ok := grantErrorMessageMap[wantMsg]; ok {
-		if strings.Contains(errStr, mapped) {
-			return
-		}
-	}
-
-	// Try matching key parts of the error message
-	// Extract the most distinctive part of the Tailscale message
-	keyParts := extractErrorKeyParts(wantMsg)
-	for _, part := range keyParts {
-		if strings.Contains(errStr, part) {
-			return
-		}
-	}
-
 	t.Errorf("%s: error message mismatch\n  tailscale wants: %q\n  headscale got:   %q",
 		testID, wantMsg, errStr)
 }
 
-// extractErrorKeyParts extracts distinctive substrings from an error message
-// that should appear in any equivalent error message.
-func extractErrorKeyParts(msg string) []string {
-	var parts []string
-
-	// Common patterns to extract
-	if strings.Contains(msg, "tag:") {
-		// Extract tag references like tag:nonexistent
-		for word := range strings.FieldsSeq(msg) {
-			word = strings.Trim(word, `"'`)
-			if strings.HasPrefix(word, "tag:") {
-				parts = append(parts, word)
-			}
-		}
-	}
-
-	if strings.Contains(msg, "autogroup:") {
-		for word := range strings.FieldsSeq(msg) {
-			word = strings.Trim(word, `"'`)
-			if strings.HasPrefix(word, "autogroup:") {
-				parts = append(parts, word)
-			}
-		}
-	}
-
-	if strings.Contains(msg, "capability name") {
-		parts = append(parts, "capability")
-	}
-
-	if strings.Contains(msg, "port range") {
-		parts = append(parts, "port")
-	}
-
-	return parts
-}
-
 // testGrantSuccess verifies that a valid policy produces the expected
 // packet filter rules for each node.
 func testGrantSuccess(
@@ -554,34 +491,9 @@ func testGrantSuccess(
 
 	for nodeName, capture := range tf.Captures {
 		t.Run(nodeName, func(t *testing.T) {
-			// Check if this node was offline during capture.
-			// kakuna (tag:prod) was frequently offline (132 of 188 success tests).
-			// When offline, packet_filter_rules is null and topology shows
-			// hostname="unknown" with empty tags.
-			if len(capture.PacketFilterRules) == 0 {
-				topoNode, exists := tf.Topology.Nodes[nodeName]
-				if exists && (topoNode.Hostname == "unknown" || topoNode.Hostname == "") {
-					t.Skipf(
-						"node %s was offline during Tailscale capture (hostname=%q)",
-						nodeName,
-						topoNode.Hostname,
-					)
-
-					return
-				}
-				// Node was online but has empty rules — means Tailscale
-				// produced no rules. headscale should also produce no rules.
-			}
-
 			node := findGrantsNode(nodes, nodeName)
-			if node == nil {
-				t.Skipf(
-					"node %s not found in test setup (may be a test-specific node)",
-					nodeName,
-				)
-
-				return
-			}
+			require.NotNilf(t, node,
+				"golden node %s not found in test setup", nodeName)
 
 			// Compile headscale filter rules for this node
 			gotRules, err := pol.compileFilterRulesForNode(

hscontrol/policy/v2/tailscale_routes_data_compat_test.go

@@ -171,9 +171,6 @@ func buildRoutesUsersAndNodes(
 	return users, nodes
 }
 
-// routesSkipReasons documents WHY tests are expected to fail.
-var routesSkipReasons = map[string]string{}
-
 // subnetToSubnetFiles lists the golden files that test subnet-to-subnet
 // ACL scenarios. These are the scenarios where the fix for issue #3157
 // (CanAccess considering subnet routes as source identity) is critical.
@@ -210,15 +207,6 @@ func TestRoutesCompat(t *testing.T) {
 		t.Run(tf.TestID, func(t *testing.T) {
 			t.Parallel()
 
-			if reason, ok := routesSkipReasons[tf.TestID]; ok {
-				t.Skipf(
-					"TODO: %s — see routesSkipReasons for details",
-					reason,
-				)
-
-				return
-			}
-
 			// Build topology from JSON
 			users, nodes := buildRoutesUsersAndNodes(t, tf.Topology)
 
@@ -245,14 +233,8 @@ func TestRoutesCompat(t *testing.T) {
 			for nodeName, capture := range tf.Captures {
 				t.Run(nodeName, func(t *testing.T) {
 					node := findNodeByGivenName(nodes, nodeName)
-					if node == nil {
-						t.Skipf(
-							"node %s not found in topology",
-							nodeName,
-						)
-
-						return
-					}
+					require.NotNilf(t, node,
+						"golden node %s not found in topology", nodeName)
 
 					compiledRules, err := pol.compileFilterRulesForNode(
 						users,
@@ -532,8 +514,12 @@ func TestRoutesCompatPeerVisibility(t *testing.T) {
 			)
 
 			t.Run("CanAccess", func(t *testing.T) {
-				// For each expected pair, verify that at least one
-				// direction of CanAccess returns true.
+				// Peer visibility is satisfied if either direction of
+				// CanAccess returns true — that mirrors the
+				// ReduceNodes semantics used at runtime. An ACL may
+				// legitimately grant access in only one direction
+				// (tested in ReduceNodes below), and a symmetric
+				// assertion would reject the intentional asymmetry.
 				for pair := range wantPairs {
 					nodeA := findNodeByGivenName(nodes, pair[0])
 					nodeB := findNodeByGivenName(nodes, pair[1])
@@ -544,15 +530,15 @@ func TestRoutesCompatPeerVisibility(t *testing.T) {
 						"node %s not found", pair[1],
 					)
 
-					// Get matchers — these are the unreduced global
-					// matchers used for peer relationship determination.
-					matchers, err := pm.MatchersForNode(nodeA.View())
+					matchersA, err := pm.MatchersForNode(nodeA.View())
+					require.NoError(t, err)
+					matchersB, err := pm.MatchersForNode(nodeB.View())
 					require.NoError(t, err)
 
 					canAccess := nodeA.View().CanAccess(
-						matchers, nodeB.View(),
+						matchersA, nodeB.View(),
 					) || nodeB.View().CanAccess(
-						matchers, nodeA.View(),
+						matchersB, nodeA.View(),
 					)
 					assert.Truef(t, canAccess,
 						"%s: %s and %s should be peers "+
@@ -643,13 +629,20 @@ func TestRoutesCompatPeerVisibility(t *testing.T) {
 
 					for _, rule := range rules {
 						for _, dp := range rule.DstPorts {
-							prefix, err := netip.ParsePrefix(
-								dp.IP,
-							)
-							if err != nil {
+							if dp.IP == "*" {
 								continue
 							}
 
+							prefix, err := netip.ParsePrefix(dp.IP)
+							if err != nil {
+								// DstPorts.IP can be a bare IP without /prefix.
+								addr, addrErr := netip.ParseAddr(dp.IP)
+								require.NoErrorf(t, addrErr,
+									"golden DstPorts.IP %q unparseable as prefix or addr", dp.IP)
+
+								prefix = netip.PrefixFrom(addr, addr.BitLen())
+							}
+
 							dstPrefixes = append(
 								dstPrefixes, prefix,
 							)
@@ -767,12 +760,18 @@ func TestRoutesCompatAutoApproval(t *testing.T) {
 					len(nodeDef.ApprovedRoutes),
 				)
 				for _, r := range nodeDef.ApprovedRoutes {
-					approvedSet[netip.MustParsePrefix(r)] = true
+					pfx, err := netip.ParsePrefix(r)
+					require.NoErrorf(t, err,
+						"golden approved_route %q for %s", r, nodeName)
+
+					approvedSet[pfx] = true
 				}
 
 				t.Run(nodeName, func(t *testing.T) {
 					for _, routeStr := range nodeDef.RoutableIPs {
-						route := netip.MustParsePrefix(routeStr)
+						route, err := netip.ParsePrefix(routeStr)
+						require.NoErrorf(t, err,
+							"golden routable_ip %q for %s", routeStr, nodeName)
 
 						wantApproved := approvedSet[route]
 						gotApproved := pm.NodeCanApproveRoute(
@@ -841,12 +840,6 @@ func TestRoutesCompatReduceRoutes(t *testing.T) {
 		t.Run(tf.TestID, func(t *testing.T) {
 			t.Parallel()
 
-			if reason, ok := routesSkipReasons[tf.TestID]; ok {
-				t.Skipf("TODO: %s", reason)
-
-				return
-			}
-
 			// Build topology from JSON.
 			users, nodes := buildRoutesUsersAndNodes(t, tf.Topology)
 
@@ -879,9 +872,17 @@ func TestRoutesCompatReduceRoutes(t *testing.T) {
 					var dstPrefixes []netip.Prefix
 
 					for _, dp := range rule.DstPorts {
+						if dp.IP == "*" {
+							continue
+						}
+
 						prefix, parseErr := netip.ParsePrefix(dp.IP)
 						if parseErr != nil {
-							continue
+							addr, addrErr := netip.ParseAddr(dp.IP)
+							require.NoErrorf(t, addrErr,
+								"golden DstPorts.IP %q unparseable", dp.IP)
+
+							prefix = netip.PrefixFrom(addr, addr.BitLen())
 						}
 
 						if !slices.Contains(dstPrefixes, prefix) {
@@ -897,12 +898,27 @@ func TestRoutesCompatReduceRoutes(t *testing.T) {
 					var srcBuilder netipx.IPSetBuilder
 
 					for _, srcIP := range rule.SrcIPs {
+						if srcIP == "*" {
+							continue
+						}
+
+						// SrcIPs can be CIDR prefixes, bare IPs, or
+						// dash-separated IP ranges (e.g. "100.115.94.0-100.127.255.255").
+						if strings.Contains(srcIP, "-") {
+							ipRange, rangeErr := netipx.ParseIPRange(srcIP)
+							require.NoErrorf(t, rangeErr,
+								"golden SrcIP range %q unparseable", srcIP)
+
+							srcBuilder.AddRange(ipRange)
+
+							continue
+						}
+
 						prefix, parseErr := netip.ParsePrefix(srcIP)
 						if parseErr != nil {
 							addr, parseErr2 := netip.ParseAddr(srcIP)
-							if parseErr2 != nil {
-								continue
-							}
+							require.NoErrorf(t, parseErr2,
+								"golden SrcIP %q unparseable as prefix or addr", srcIP)
 
 							srcBuilder.Add(addr)
 
@@ -1154,12 +1170,6 @@ func TestRoutesCompatNoPeersBeyondCaptures(t *testing.T) {
 		t.Run(tf.TestID, func(t *testing.T) {
 			t.Parallel()
 
-			if reason, ok := routesSkipReasons[tf.TestID]; ok {
-				t.Skipf("TODO: %s", reason)
-
-				return
-			}
-
 			users, nodes := buildRoutesUsersAndNodes(t, tf.Topology)
 			policyJSON := convertPolicyUserEmails(tf.Input.FullPolicy)
 
@@ -1423,14 +1433,9 @@ func TestRoutesCompatPeerAllowedIPs(t *testing.T) {
 		t.Run(tf.TestID, func(t *testing.T) {
 			t.Parallel()
 
-			if reason, ok := routesSkipReasons[tf.TestID]; ok {
-				t.Skipf("TODO: %s", reason)
-
-				return
-			}
-
+			// SaaS rejected this policy — verify headscale also rejects it.
 			if tf.Error {
-				t.Skipf("%s: SaaS rejected the policy", tf.TestID)
+				testRoutesError(t, tf)
 
 				return
 			}
@@ -1508,3 +1513,67 @@ func TestRoutesCompatPeerAllowedIPs(t *testing.T) {
 		"no golden files with netmap data found — test is vacuous",
 	)
 }
+
+// testRoutesError verifies that an invalid policy produces the expected error.
+func testRoutesError(t *testing.T, tf *testcapture.Capture) {
+	t.Helper()
+
+	policyJSON := convertPolicyUserEmails(tf.Input.FullPolicy)
+
+	pol, err := unmarshalPolicy(policyJSON)
+	if err != nil {
+		// Parse-time error.
+		if tf.Input.APIResponseBody != nil {
+			wantMsg := tf.Input.APIResponseBody.Message
+			if wantMsg != "" {
+				assertRoutesErrorContains(t, err, wantMsg, tf.TestID)
+			}
+		}
+
+		return
+	}
+
+	err = pol.validate()
+	if err != nil {
+		if tf.Input.APIResponseBody != nil {
+			wantMsg := tf.Input.APIResponseBody.Message
+			if wantMsg != "" {
+				assertRoutesErrorContains(t, err, wantMsg, tf.TestID)
+			}
+		}
+
+		return
+	}
+
+	t.Errorf(
+		"%s: expected error but policy parsed and validated successfully",
+		tf.TestID,
+	)
+}
+
+// assertRoutesErrorContains requires that headscale's error contains
+// the Tailscale SaaS error message exactly. Divergence means an
+// emitter needs to be aligned, not papered over with a translation
+// table.
+func assertRoutesErrorContains(
+	t *testing.T,
+	err error,
+	wantMsg string,
+	testID string,
+) {
+	t.Helper()
+
+	errStr := err.Error()
+	if strings.Contains(errStr, wantMsg) {
+		return
+	}
+
+	t.Errorf(
+		"%s: error message mismatch\n"+
+			"  want (tailscale): %q\n"+
+			"  got  (headscale): %q",
+		testID,
+		wantMsg,
+		errStr,
+	)
+}

hscontrol/policy/v2/tailscale_ssh_data_compat_test.go

@@ -18,6 +18,7 @@ package v2
 
 import (
 	"path/filepath"
+	"strings"
 	"testing"
 
 	"github.com/google/go-cmp/cmp"
@@ -30,7 +31,6 @@ import (
 	"tailscale.com/tailcfg"
 )
 
-
 // setupSSHDataCompatUsers returns the 3 test users for SSH data-driven
 // compatibility tests. Users get norse-god names; nodes get original-151
 // pokémon names — matching the anonymized identifiers tscap writes into
@@ -129,11 +129,24 @@ func loadSSHTestFile(t *testing.T, path string) *testcapture.Capture {
 // sshSkipReasons documents why each skipped test fails and what needs to be
 // fixed. Tests are grouped by root cause to identify high-impact changes.
 var sshSkipReasons = map[string]string{
-	// user:*@passkey wildcard pattern not supported in headscale.
+	// USER_PASSKEY_WILDCARD (2 tests)
+	//
 	// headscale does not support passkey authentication and has no
-	// equivalent for this wildcard pattern.
+	// equivalent for the user:*@passkey wildcard pattern.
 	"ssh-b5":  "user:*@passkey wildcard not supported in headscale",
 	"ssh-d10": "user:*@passkey wildcard not supported in headscale",
+
+	// DOMAIN_NOT_ASSOCIATED (4 tests)
+	//
+	// SaaS validates that email domains in user:*@domain and
+	// localpart:*@domain expressions are configured tailnet domains.
+	// headscale has no concept of "associated tailnet domains" — it
+	// only has users with email addresses. These policies are
+	// legitimately rejected by SaaS but not by headscale.
+	"ssh-b4": "domain validation: headscale has no 'associated tailnet domains' concept",
+	"ssh-d1": "domain validation: headscale has no 'associated tailnet domains' concept",
+	"ssh-e1": "domain validation: headscale has no 'associated tailnet domains' concept",
+	"ssh-e2": "domain validation: headscale has no 'associated tailnet domains' concept",
 }
 
 // TestSSHDataCompat is a data-driven test that loads all ssh-*.hujson test
@@ -159,6 +172,16 @@ func TestSSHDataCompat(t *testing.T) {
 		"no ssh-*.hujson test files found in testdata/ssh_results/",
 	)
 
+	allHujson, err := filepath.Glob(
+		filepath.Join("testdata", "ssh_results", "*.hujson"),
+	)
+	require.NoError(t, err, "failed to glob all hujson files")
+	require.Lenf(t, files, len(allHujson),
+		"ssh_results/ contains hujson files not picked up by the ssh-*.hujson loader; "+
+			"loader sees %d, directory has %d. Stale fixtures should be deleted.",
+		len(files), len(allHujson),
+	)
+
 	t.Logf("Loaded %d SSH test files", len(files))
 
 	users := setupSSHDataCompatUsers()
@@ -179,9 +202,10 @@ func TestSSHDataCompat(t *testing.T) {
 				return
 			}
 
-			// Skip captures the SaaS rejected — no expected SSH rules to compare against.
+			// SaaS rejected this policy — verify headscale also rejects it.
 			if tf.Error {
-				t.Skipf("%s: SaaS rejected the policy (api_response_code=%d); no expected SSH rules captured", tf.TestID, tf.Input.APIResponseCode)
+				testSSHError(t, tf)
+
 				return
 			}
 
@@ -190,7 +214,7 @@ func TestSSHDataCompat(t *testing.T) {
 			// different node IPs.
 			nodes := buildGrantsNodesFromCapture(users, tf)
 
-			// Use the captured full policy verbatim. Anonymization in
+			// Use the captured full policy as is. Anonymization in
 			// tscap already rewrites SaaS emails to @example.com.
 			policyJSON := tf.Input.FullPolicy
 
@@ -206,14 +230,12 @@ func TestSSHDataCompat(t *testing.T) {
 			for nodeName, capture := range tf.Captures {
 				t.Run(nodeName, func(t *testing.T) {
 					node := findNodeByGivenName(nodes, nodeName)
-					if node == nil {
-						t.Skipf("node %s not in this test's node set", nodeName)
-						return
-					}
+					require.NotNilf(t, node,
+						"golden node %s not found in test setup", nodeName)
 
 					// Compile headscale SSH policy for this node
 					gotSSH, err := pol.compileSSHPolicy(
-						"unused-server-url",
+						"https://unused",
 						users,
 						node.View(),
 						nodes.ViewSlice(),
@@ -242,40 +264,11 @@ func TestSSHDataCompat(t *testing.T) {
 					// Sort principals within rules (order doesn't matter).
 					// Do NOT sort rules — order matters (first-match-wins).
 					//
-					// Ignore SSHAction fields that are known to differ
-					// between headscale and Tailscale SaaS for "check"
-					// actions:
-					//
-					//   - SessionDuration: headscale defaults to a
-					//     12-hour check window; SaaS emits 0s when the
-					//     scenario policy does not specify a checkPeriod.
-					//
-					//   - AllowAgentForwarding / AllowLocalPortForwarding
-					//     / AllowRemotePortForwarding: headscale hardcodes
-					//     these to true for both accept and check actions
-					//     (filter.go sshAccept / sshCheck); SaaS emits
-					//     false for check actions.
-					//
-					//   - HoldAndDelegate: headscale uses a URL template
-					//     containing "/from/…?ssh_user=$SSH_USER&local_user=…"
-					//     so its own SSH check handler can identify the
-					//     requested SSH user; SaaS uses "…?local_user=…"
-					//     without the ssh_user query parameter. Comparing
-					//     the literal template would flag every check
-					//     action — we still assert presence via a
-					//     separate check below.
 					opts := cmp.Options{
 						cmpopts.SortSlices(func(a, b *tailcfg.SSHPrincipal) bool {
 							return a.NodeIP < b.NodeIP
 						}),
 						cmpopts.EquateEmpty(),
-						cmpopts.IgnoreFields(tailcfg.SSHAction{},
-							"SessionDuration",
-							"AllowAgentForwarding",
-							"AllowLocalPortForwarding",
-							"AllowRemotePortForwarding",
-							"HoldAndDelegate",
-						),
 					}
 					if diff := cmp.Diff(wantSSH, gotSSH, opts...); diff != "" {
 						t.Errorf(
@@ -316,3 +309,97 @@ func TestSSHDataCompat(t *testing.T) {
 		})
 	}
 }
+
+// sshErrorMessageMap maps Tailscale SaaS error substrings to headscale
+// equivalents where the wording differs but the meaning is the same.
+var sshErrorMessageMap = map[string]string{}
+
+// testSSHError verifies that an invalid policy produces the expected error.
+func testSSHError(t *testing.T, tf *testcapture.Capture) {
+	t.Helper()
+
+	policyJSON := []byte(tf.Input.FullPolicy)
+
+	pol, err := unmarshalPolicy(policyJSON)
+	if err != nil {
+		// Parse-time error.
+		if tf.Input.APIResponseBody != nil {
+			wantMsg := tf.Input.APIResponseBody.Message
+			if wantMsg != "" {
+				assertSSHErrorContains(t, err, wantMsg, tf.TestID)
+			}
+		}
+
+		return
+	}
+
+	err = pol.validate()
+	if err != nil {
+		if tf.Input.APIResponseBody != nil {
+			wantMsg := tf.Input.APIResponseBody.Message
+			if wantMsg != "" {
+				assertSSHErrorContains(t, err, wantMsg, tf.TestID)
+			}
+		}
+
+		return
+	}
+
+	t.Errorf(
+		"%s: expected error but policy parsed and validated successfully",
+		tf.TestID,
+	)
+}
+
+// assertSSHErrorContains checks that an error message matches the
+// expected Tailscale SaaS message, using progressive fallbacks:
+//  1. Direct substring match
+//  2. Mapped equivalent from sshErrorMessageMap
+//  3. Key-part extraction (tags, autogroups)
+//  4. t.Errorf on no match (strict)
+func assertSSHErrorContains(
+	t *testing.T,
+	err error,
+	wantMsg string,
+	testID string,
+) {
+	t.Helper()
+
+	errStr := err.Error()
+
+	// 1. Direct substring match.
+	if strings.Contains(errStr, wantMsg) {
+		return
+	}
+
+	// 2. Mapped equivalent.
+	for tsKey, hsKey := range sshErrorMessageMap {
+		if strings.Contains(wantMsg, tsKey) &&
+			strings.Contains(errStr, hsKey) {
+			return
+		}
+	}
+
+	// 3. Key-part extraction.
+	for _, part := range []string{
+		"autogroup:",
+		"tag:",
+		"undefined",
+		"not valid",
+	} {
+		if strings.Contains(wantMsg, part) &&
+			strings.Contains(errStr, part) {
+			return
+		}
+	}
+
+	// 4. No match — strict failure.
+	t.Errorf(
+		"%s: error message mismatch\n"+
+			"  want (tailscale): %q\n"+
+			"  got  (headscale): %q",
+		testID,
+		wantMsg,
+		errStr,
+	)
+}

hscontrol/policy/v2/test.go

@@ -0,0 +1,426 @@
+package v2
+
+import (
+	"errors"
+	"fmt"
+	"net/netip"
+	"slices"
+	"strings"
+
+	"github.com/juanfont/headscale/hscontrol/types"
+	"github.com/juanfont/headscale/hscontrol/util"
+	"tailscale.com/tailcfg"
+	"tailscale.com/types/views"
+)
+
+// Tailscale's policy file `tests` block validates a policy against operator
+// assertions: from a given src, named dst:port pairs must be accepted, and
+// (optionally) other dst:port pairs must be denied. They run at user-write
+// boundaries — `headscale policy set`, file-mode reload after a change,
+// `headscale policy check` — and reject the write if any assertion fails.
+// Boot-time reload of an already-stored policy does not run them, so a
+// stale referenced entity (e.g. a deleted user) cannot lock the server out.
+//
+// The tests evaluate against the compiled global filter rules, which fold in
+// both `acls` and `grants`, so the `tests` block validates the whole policy.
+
+// errPolicyTestsFailed wraps the rendered failure body so callers can
+// type-assert when they need to react differently to test failures vs. parse
+// errors. The Error() prefix is "test(s) failed", the same string Tailscale
+// SaaS returns in the api_response_body.message — see
+// hscontrol/policy/v2/testdata/policytest_results/.
+var (
+	errPolicyTestsFailed   = errors.New("test(s) failed")
+	errTestDestinationNoIP = errors.New("destination resolved to no IP addresses")
+)
+
+// PolicyTest is one entry in the policy's `tests` block.
+type PolicyTest struct {
+	// Src is a single source alias (user, group, tag, host, autogroup, or IP).
+	// Tailscale only supports a single src per test entry.
+	Src string `json:"src"`
+
+	// Proto restricts the test to one protocol. Empty matches the default
+	// set the client applies when proto is omitted (TCP/UDP/ICMP).
+	Proto Protocol `json:"proto,omitempty"`
+
+	// Accept lists destinations in `host:port` form that must be reachable
+	// from Src. A test fails if any entry is denied by the compiled filter.
+	Accept []string `json:"accept,omitempty"`
+
+	// Deny lists destinations in `host:port` form that must NOT be reachable
+	// from Src. A test fails if any entry is allowed by the compiled filter.
+	Deny []string `json:"deny,omitempty"`
+}
+
+// PolicyTestResult is the outcome of a single PolicyTest.
+type PolicyTestResult struct {
+	Src    string   `json:"src"`
+	Proto  Protocol `json:"proto,omitempty"`
+	Passed bool     `json:"passed"`
+
+	// Errors are non-assertion problems: src failed to resolve, dst was
+	// malformed, etc. These cause the test to fail.
+	Errors []string `json:"errors,omitempty"`
+
+	// AcceptOK / AcceptFail / DenyOK / DenyFail partition the per-dst
+	// outcomes for diagnostics.
+	AcceptOK   []string `json:"accept_ok,omitempty"`
+	AcceptFail []string `json:"accept_fail,omitempty"`
+	DenyOK     []string `json:"deny_ok,omitempty"`
+	DenyFail   []string `json:"deny_fail,omitempty"`
+}
+
+// PolicyTestResults aggregates a run.
+type PolicyTestResults struct {
+	AllPassed bool               `json:"all_passed"`
+	Results   []PolicyTestResult `json:"results"`
+}
+
+// Errors renders the per-test failure breakdown joined by newlines.
+// Tailscale SaaS itself only returns the literal "test(s) failed" — we
+// keep the per-test detail because it is significantly more useful in
+// CLI / config-reload paths where the user does not have a separate
+// audit endpoint to consult.
+func (r PolicyTestResults) Errors() string {
+	if r.AllPassed {
+		return ""
+	}
+
+	var lines []string
+
+	for _, res := range r.Results {
+		if res.Passed {
+			continue
+		}
+
+		protoSuffix := ""
+		if res.Proto != "" {
+			protoSuffix = fmt.Sprintf(" (%s)", res.Proto)
+		}
+
+		for _, e := range res.Errors {
+			lines = append(lines, fmt.Sprintf("%s%s: %s", res.Src, protoSuffix, e))
+		}
+
+		for _, dst := range res.AcceptFail {
+			lines = append(lines, fmt.Sprintf("%s -> %s%s: expected ALLOWED, got DENIED", res.Src, dst, protoSuffix))
+		}
+
+		for _, dst := range res.DenyFail {
+			lines = append(lines, fmt.Sprintf("%s -> %s%s: expected DENIED, got ALLOWED", res.Src, dst, protoSuffix))
+		}
+	}
+
+	return strings.Join(lines, "\n")
+}
+
+// RunTests evaluates the policy's own `tests` block against the live compiled
+// filter and returns a wrapped error when any test fails. Callers that need
+// the per-test breakdown can call runPolicyTests directly.
+func (pm *PolicyManager) RunTests() error {
+	if pm == nil || pm.pol == nil || len(pm.pol.Tests) == 0 {
+		return nil
+	}
+
+	pm.mu.Lock()
+	defer pm.mu.Unlock()
+
+	results := runPolicyTests(pm.pol, pm.filter, pm.users, pm.nodes)
+	if results.AllPassed {
+		return nil
+	}
+
+	return fmt.Errorf("%w:\n%s", errPolicyTestsFailed, results.Errors())
+}
+
+// evaluateTests runs the `tests` block against a fresh compilation of pol.
+// It is the user-write sandbox: the live PolicyManager state is left
+// untouched, so a failing test rejects the write without side effects.
+func evaluateTests(pol *Policy, users []types.User, nodes views.Slice[types.NodeView]) error {
+	if pol == nil || len(pol.Tests) == 0 {
+		return nil
+	}
+
+	grants := pol.compileGrants(users, nodes)
+
+	var filter []tailcfg.FilterRule
+	if pol.ACLs == nil && pol.Grants == nil {
+		filter = tailcfg.FilterAllowAll
+	} else {
+		filter = globalFilterRules(grants)
+	}
+
+	results := runPolicyTests(pol, filter, users, nodes)
+	if results.AllPassed {
+		return nil
+	}
+
+	return fmt.Errorf("%w:\n%s", errPolicyTestsFailed, results.Errors())
+}
+
+// runPolicyTests is the pure evaluation function: given a policy, the
+// compiled filter rules derived from it, and the active users/nodes, run
+// every test and return the aggregated outcome. It does not lock anything
+// or mutate any input.
+func runPolicyTests(pol *Policy, filter []tailcfg.FilterRule, users []types.User, nodes views.Slice[types.NodeView]) PolicyTestResults {
+	results := PolicyTestResults{
+		AllPassed: true,
+		Results:   make([]PolicyTestResult, 0, len(pol.Tests)),
+	}
+
+	for _, test := range pol.Tests {
+		res := runPolicyTest(test, pol, filter, users, nodes)
+		if !res.Passed {
+			results.AllPassed = false
+		}
+
+		results.Results = append(results.Results, res)
+	}
+
+	return results
+}
+
+// runPolicyTest evaluates one PolicyTest.
+func runPolicyTest(test PolicyTest, pol *Policy, filter []tailcfg.FilterRule, users []types.User, nodes views.Slice[types.NodeView]) PolicyTestResult {
+	res := PolicyTestResult{
+		Src:    test.Src,
+		Proto:  test.Proto,
+		Passed: true,
+	}
+
+	srcPrefixes, err := resolveTestSource(test.Src, pol, users, nodes)
+	if err != nil {
+		res.Passed = false
+		res.Errors = append(res.Errors, fmt.Sprintf("failed to resolve source %q: %v", test.Src, err))
+
+		return res
+	}
+
+	if len(srcPrefixes) == 0 {
+		res.Passed = false
+		res.Errors = append(res.Errors, fmt.Sprintf("source %q resolved to no IP addresses", test.Src))
+
+		return res
+	}
+
+	for _, dst := range test.Accept {
+		allowed, err := evalReachability(srcPrefixes, dst, test.Proto, pol, filter, users, nodes)
+		if err != nil {
+			res.Passed = false
+			res.Errors = append(res.Errors, fmt.Sprintf("error testing %q: %v", dst, err))
+
+			continue
+		}
+
+		if allowed {
+			res.AcceptOK = append(res.AcceptOK, dst)
+		} else {
+			res.Passed = false
+			res.AcceptFail = append(res.AcceptFail, dst)
+		}
+	}
+
+	for _, dst := range test.Deny {
+		allowed, err := evalReachability(srcPrefixes, dst, test.Proto, pol, filter, users, nodes)
+		if err != nil {
+			res.Passed = false
+			res.Errors = append(res.Errors, fmt.Sprintf("error testing %q: %v", dst, err))
+
+			continue
+		}
+
+		if !allowed {
+			res.DenyOK = append(res.DenyOK, dst)
+		} else {
+			res.Passed = false
+			res.DenyFail = append(res.DenyFail, dst)
+		}
+	}
+
+	return res
+}
+
+// resolveTestSource resolves the Src alias of a PolicyTest into a slice of
+// netip.Prefix. parseAlias + Alias.Resolve cover every alias type the rest
+// of the policy engine supports, so tests inherit alias semantics for free.
+func resolveTestSource(src string, pol *Policy, users []types.User, nodes views.Slice[types.NodeView]) ([]netip.Prefix, error) {
+	alias, err := parseAlias(src)
+	if err != nil {
+		return nil, fmt.Errorf("invalid alias: %w", err)
+	}
+
+	addrs, err := alias.Resolve(pol, users, nodes)
+	if err != nil {
+		return nil, fmt.Errorf("resolving: %w", err)
+	}
+
+	if addrs == nil || addrs.Empty() {
+		return nil, nil
+	}
+
+	return addrs.Prefixes(), nil
+}
+
+// evalReachability reports whether traffic from any srcPrefix to dst (in
+// `host:port` form) is allowed by filter for the requested protocol.
+//
+// Empty proto means the default set the client applies when proto is
+// omitted (TCP/UDP/ICMP) — we accept a rule whose IPProto list contains
+// any of those, or rules with no IPProto restriction at all.
+func evalReachability(srcPrefixes []netip.Prefix, dst string, proto Protocol, pol *Policy, filter []tailcfg.FilterRule, users []types.User, nodes views.Slice[types.NodeView]) (bool, error) {
+	awp, err := parseDestinationAlias(dst)
+	if err != nil {
+		return false, fmt.Errorf("invalid destination %q: %w", dst, err)
+	}
+
+	dstAddrs, err := awp.Resolve(pol, users, nodes)
+	if err != nil {
+		return false, fmt.Errorf("resolving destination: %w", err)
+	}
+
+	if dstAddrs == nil || dstAddrs.Empty() {
+		return false, fmt.Errorf("%w: %q", errTestDestinationNoIP, dst)
+	}
+
+	dstPrefixes := dstAddrs.Prefixes()
+
+	// Tailscale's tests semantics: ALL src prefixes must reach the dst for
+	// the test to consider it allowed. A partial allow is a fail.
+	for _, src := range srcPrefixes {
+		if !srcReachesDst(src, dstPrefixes, awp.Ports, proto, filter) {
+			return false, nil
+		}
+	}
+
+	return true, nil
+}
+
+// parseDestinationAlias is a thin wrapper over AliasWithPorts.UnmarshalJSON
+// so callers can hand it a bare `"host:port"` string without re-implementing
+// the parse logic.
+func parseDestinationAlias(dst string) (*AliasWithPorts, error) {
+	var awp AliasWithPorts
+
+	// AliasWithPorts.UnmarshalJSON expects a quoted JSON string, so wrap.
+	err := awp.UnmarshalJSON([]byte(`"` + dst + `"`))
+	if err != nil {
+		return nil, err
+	}
+
+	return &awp, nil
+}
+
+// srcReachesDst walks the compiled filter rules and reports whether
+// traffic from src to any prefix in dstPrefixes on at least one of ports
+// (or any port when ports is empty) is allowed under proto.
+//
+// An empty test proto means the Tailscale client default set
+// {TCP, UDP, ICMP, ICMPv6} — the protocols the client tries when proto
+// is omitted. The captured Tailscale matches show these four IANA
+// numbers explicitly when no proto is set, so a rule restricted to any
+// of them satisfies an empty-proto test.
+func srcReachesDst(src netip.Prefix, dstPrefixes []netip.Prefix, ports []tailcfg.PortRange, proto Protocol, filter []tailcfg.FilterRule) bool {
+	requestedProtos := proto.toIANAProtocolNumbers()
+	if len(requestedProtos) == 0 {
+		requestedProtos = []int{ProtocolTCP, ProtocolUDP, ProtocolICMP, ProtocolIPv6ICMP}
+	}
+
+	for _, rule := range filter {
+		if !ruleMatchesSource(rule, src) {
+			continue
+		}
+
+		if !ruleMatchesProto(rule, requestedProtos) {
+			continue
+		}
+
+		if ruleAllowsAnyDest(rule, dstPrefixes, ports) {
+			return true
+		}
+	}
+
+	return false
+}
+
+// ruleMatchesSource reports whether the rule's source list contains src.
+// SrcIPs may be CIDR, single addresses, IP ranges (`a-b`), or `*`; we use
+// util.ParseIPSet to cover all of those uniformly. Unparseable entries
+// are skipped (the rule compiler emits well-formed strings, so this is
+// defence-in-depth, not error handling).
+func ruleMatchesSource(rule tailcfg.FilterRule, src netip.Prefix) bool {
+	for _, raw := range rule.SrcIPs {
+		set, err := util.ParseIPSet(raw, nil)
+		if err != nil {
+			continue
+		}
+
+		if set.OverlapsPrefix(src) {
+			return true
+		}
+	}
+
+	return false
+}
+
+// ruleMatchesProto reports whether the rule permits any of requestedProtos.
+// An unset rule.IPProto means "any protocol" and matches everything.
+// requestedProtos is the per-test protocol set: a single proto for an
+// explicit test.Proto, or the default set when test.Proto is empty.
+func ruleMatchesProto(rule tailcfg.FilterRule, requestedProtos []int) bool {
+	if len(rule.IPProto) == 0 {
+		return true
+	}
+
+	for _, ruleProto := range rule.IPProto {
+		if slices.Contains(requestedProtos, ruleProto) {
+			return true
+		}
+	}
+
+	return false
+}
+
+// ruleAllowsAnyDest reports whether at least one destination prefix in
+// dstPrefixes is allowed by at least one of the rule's DstPorts entries
+// for at least one of ports (or any port when ports is empty).
+func ruleAllowsAnyDest(rule tailcfg.FilterRule, dstPrefixes []netip.Prefix, ports []tailcfg.PortRange) bool {
+	for _, dp := range rule.DstPorts {
+		if !destEntryMatchesPrefixes(dp, dstPrefixes) {
+			continue
+		}
+
+		if portsAllowed(ports, dp.Ports) {
+			return true
+		}
+	}
+
+	return false
+}
+
+// destEntryMatchesPrefixes reports whether the rule's NetPortRange.IP
+// (CIDR, single IP, IP range, or "*") covers any prefix in dstPrefixes.
+func destEntryMatchesPrefixes(dp tailcfg.NetPortRange, dstPrefixes []netip.Prefix) bool {
+	set, err := util.ParseIPSet(dp.IP, nil)
+	if err != nil {
+		return false
+	}
+
+	return slices.ContainsFunc(dstPrefixes, set.OverlapsPrefix)
+}
+
+// portsAllowed reports whether at least one requested port is contained
+// in allowed. Empty requested means "any port".
+func portsAllowed(requested []tailcfg.PortRange, allowed tailcfg.PortRange) bool {
+	if len(requested) == 0 {
+		return true
+	}
+
+	for _, r := range requested {
+		if r.First >= allowed.First && r.Last <= allowed.Last {
+			return true
+		}
+	}
+
+	return false
+}

hscontrol/policy/v2/test_test.go

@@ -0,0 +1,424 @@
+package v2
+
+import (
+	"strings"
+	"testing"
+
+	"github.com/juanfont/headscale/hscontrol/types"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+	"gorm.io/gorm"
+)
+
+// policyTestUsers/policyTestNodes are reused across the test cases below to
+// keep each table row focussed on the policy + tests under exercise.
+func policyTestUsers() types.Users {
+	return types.Users{
+		{Model: gorm.Model{ID: 1}, Name: "alice", Email: "alice@headscale.net"},
+		{Model: gorm.Model{ID: 2}, Name: "bob", Email: "bob@headscale.net"},
+	}
+}
+
+func policyTestNodes(users types.Users) types.Nodes {
+	nodes := types.Nodes{
+		// alice's user-owned laptop
+		{
+			ID:       1,
+			Hostname: "alice-laptop",
+			IPv4:     ap("100.64.0.1"),
+			IPv6:     ap("fd7a:115c:a1e0::1"),
+			User:     &users[0],
+			UserID:   &users[0].ID,
+		},
+		// bob's user-owned laptop
+		{
+			ID:       2,
+			Hostname: "bob-laptop",
+			IPv4:     ap("100.64.0.2"),
+			IPv6:     ap("fd7a:115c:a1e0::2"),
+			User:     &users[1],
+			UserID:   &users[1].ID,
+		},
+		// tagged server (created via tagged preauth key from alice)
+		{
+			ID:       3,
+			Hostname: "server",
+			IPv4:     ap("100.64.0.3"),
+			IPv6:     ap("fd7a:115c:a1e0::3"),
+			User:     &users[0],
+			UserID:   &users[0].ID,
+			Tags:     []string{"tag:server"},
+		},
+	}
+
+	return nodes
+}
+
+// TestRunTests covers the engine's per-test outcome reporting. Each row
+// constructs a PolicyManager (which also runs SetPolicy's sandbox) and
+// checks the resulting RunTests behaviour. SetPolicy gating is exercised
+// separately in TestSetPolicyRejectsFailingTests.
+func TestRunTests(t *testing.T) {
+	users := policyTestUsers()
+	nodes := policyTestNodes(users)
+
+	tests := []struct {
+		name        string
+		policy      string
+		wantPass    bool
+		wantErrSub  []string // substrings expected in the rendered error
+		wantNoErrIs error    // sentinel the error must wrap
+	}{
+		{
+			name: "all-pass-user-to-tag",
+			policy: `{
+				"tagOwners": { "tag:server": ["alice@headscale.net"] },
+				"acls": [{
+					"action": "accept",
+					"src": ["alice@headscale.net"],
+					"dst": ["tag:server:22"]
+				}],
+				"tests": [{
+					"src": "alice@headscale.net",
+					"accept": ["tag:server:22"]
+				}]
+			}`,
+			wantPass: true,
+		},
+		{
+			name: "accept-fail-blocked-by-policy",
+			policy: `{
+				"tagOwners": { "tag:server": ["alice@headscale.net"] },
+				"acls": [{
+					"action": "accept",
+					"src": ["alice@headscale.net"],
+					"dst": ["tag:server:22"]
+				}],
+				"tests": [{
+					"src": "bob@headscale.net",
+					"accept": ["tag:server:22"]
+				}]
+			}`,
+			wantPass:    false,
+			wantErrSub:  []string{"bob@headscale.net", "tag:server:22", "expected ALLOWED"},
+			wantNoErrIs: errPolicyTestsFailed,
+		},
+		{
+			name: "deny-fail-policy-allows-traffic",
+			policy: `{
+				"tagOwners": { "tag:server": ["alice@headscale.net"] },
+				"acls": [{
+					"action": "accept",
+					"src": ["alice@headscale.net"],
+					"dst": ["tag:server:22"]
+				}],
+				"tests": [{
+					"src": "alice@headscale.net",
+					"deny": ["tag:server:22"]
+				}]
+			}`,
+			wantPass:    false,
+			wantErrSub:  []string{"alice@headscale.net", "tag:server:22", "expected DENIED"},
+			wantNoErrIs: errPolicyTestsFailed,
+		},
+		{
+			name: "unknown-src-user",
+			policy: `{
+				"acls": [{
+					"action": "accept",
+					"src": ["*"],
+					"dst": ["*:*"]
+				}],
+				"tests": [{
+					"src": "ghost@headscale.net",
+					"accept": ["alice-laptop:22"]
+				}]
+			}`,
+			wantPass:    false,
+			wantErrSub:  []string{"ghost@headscale.net", "failed to resolve source"},
+			wantNoErrIs: errPolicyTestsFailed,
+		},
+		// "malformed-dst-missing-port" used to live here; structural
+		// shape errors are now caught at parse by validateTests, so
+		// RunTests no longer sees them. The parse-side behaviour is
+		// covered by TestUnmarshalPolicy/tests-* in types_test.go.
+		{
+			name: "wildcard-src-passes",
+			policy: `{
+				"tagOwners": { "tag:server": ["alice@headscale.net"] },
+				"acls": [{
+					"action": "accept",
+					"src": ["*"],
+					"dst": ["tag:server:80"]
+				}],
+				"tests": [{
+					"src": "alice@headscale.net",
+					"accept": ["tag:server:80"]
+				}]
+			}`,
+			wantPass: true,
+		},
+		{
+			name: "proto-restrict-tcp-only",
+			policy: `{
+				"tagOwners": { "tag:server": ["alice@headscale.net"] },
+				"acls": [{
+					"action": "accept",
+					"proto": "tcp",
+					"src": ["alice@headscale.net"],
+					"dst": ["tag:server:22"]
+				}],
+				"tests": [
+					{
+						"src": "alice@headscale.net",
+						"proto": "tcp",
+						"accept": ["tag:server:22"]
+					},
+					{
+						"src": "alice@headscale.net",
+						"proto": "udp",
+						"deny": ["tag:server:22"]
+					}
+				]
+			}`,
+			wantPass: true,
+		},
+		{
+			name: "grants-only-policy-evaluated",
+			policy: `{
+				"tagOwners": { "tag:server": ["alice@headscale.net"] },
+				"grants": [{
+					"src": ["alice@headscale.net"],
+					"dst": ["tag:server"],
+					"ip":  ["22"]
+				}],
+				"tests": [{
+					"src": "alice@headscale.net",
+					"accept": ["tag:server:22"]
+				}]
+			}`,
+			wantPass: true,
+		},
+		{
+			name: "mixed-pass-and-fail-reports-failure",
+			policy: `{
+				"tagOwners": { "tag:server": ["alice@headscale.net"] },
+				"acls": [{
+					"action": "accept",
+					"src": ["alice@headscale.net"],
+					"dst": ["tag:server:22"]
+				}],
+				"tests": [
+					{
+						"src": "alice@headscale.net",
+						"accept": ["tag:server:22"]
+					},
+					{
+						"src": "bob@headscale.net",
+						"accept": ["tag:server:22"]
+					}
+				]
+			}`,
+			wantPass:    false,
+			wantErrSub:  []string{"bob@headscale.net", "expected ALLOWED"},
+			wantNoErrIs: errPolicyTestsFailed,
+		},
+		{
+			name: "no-tests-block-is-no-op",
+			policy: `{
+				"acls": [{
+					"action": "accept",
+					"src": ["*"],
+					"dst": ["*:*"]
+				}]
+			}`,
+			wantPass: true,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			pm, err := NewPolicyManager([]byte(tt.policy), users, nodes.ViewSlice())
+			require.NoError(t, err, "policy must parse and compile")
+
+			runErr := pm.RunTests()
+			if tt.wantPass {
+				require.NoError(t, runErr, "tests should pass")
+
+				return
+			}
+
+			require.Error(t, runErr, "tests should fail")
+			require.ErrorIs(t, runErr, tt.wantNoErrIs, "error should wrap errPolicyTestsFailed")
+
+			for _, sub := range tt.wantErrSub {
+				assert.Contains(t, runErr.Error(), sub, "rendered error should mention %q", sub)
+			}
+		})
+	}
+}
+
+// TestSetPolicyRejectsFailingTests asserts that SetPolicy is the user-write
+// boundary: a policy whose tests fail must be rejected without mutating the
+// live PolicyManager. NewPolicyManager (boot path) does not run tests.
+func TestSetPolicyRejectsFailingTests(t *testing.T) {
+	users := policyTestUsers()
+	nodes := policyTestNodes(users)
+
+	good := `{
+		"tagOwners": { "tag:server": ["alice@headscale.net"] },
+		"acls": [{
+			"action": "accept",
+			"src": ["alice@headscale.net"],
+			"dst": ["tag:server:22"]
+		}],
+		"tests": [{
+			"src": "alice@headscale.net",
+			"accept": ["tag:server:22"]
+		}]
+	}`
+
+	bad := `{
+		"tagOwners": { "tag:server": ["alice@headscale.net"] },
+		"acls": [{
+			"action": "accept",
+			"src": ["alice@headscale.net"],
+			"dst": ["tag:server:22"]
+		}],
+		"tests": [{
+			"src": "bob@headscale.net",
+			"accept": ["tag:server:22"]
+		}]
+	}`
+
+	pm, err := NewPolicyManager([]byte(good), users, nodes.ViewSlice())
+	require.NoError(t, err)
+
+	beforeFilter, _ := pm.Filter()
+
+	changed, err := pm.SetPolicy([]byte(bad))
+	require.Error(t, err, "SetPolicy must reject a policy whose tests fail")
+	require.False(t, changed, "SetPolicy must report no change when rejected")
+	require.ErrorIs(t, err, errPolicyTestsFailed)
+	require.Contains(t, err.Error(), "expected ALLOWED")
+
+	afterFilter, _ := pm.Filter()
+	require.Len(t, afterFilter, len(beforeFilter), "live filter must not change after a rejected SetPolicy")
+}
+
+// TestNewPolicyManagerSkipsTests asserts the boot path does not evaluate
+// tests, so a stale stored policy referencing a now-deleted user does not
+// stop the server from booting.
+func TestNewPolicyManagerSkipsTests(t *testing.T) {
+	users := policyTestUsers()
+	nodes := policyTestNodes(users)
+
+	// Tests reference "ghost@headscale.net" which doesn't exist. Boot
+	// must not error.
+	stale := `{
+		"acls": [{
+			"action": "accept",
+			"src": ["*"],
+			"dst": ["*:*"]
+		}],
+		"tests": [{
+			"src": "ghost@headscale.net",
+			"accept": ["alice-laptop:22"]
+		}]
+	}`
+
+	pm, err := NewPolicyManager([]byte(stale), users, nodes.ViewSlice())
+	require.NoError(t, err, "boot must not run tests")
+	require.NotNil(t, pm)
+
+	// And a subsequent SetPolicy of the same body must reject — that's
+	// the user-write path.
+	_, err = pm.SetPolicy([]byte(stale))
+	require.Error(t, err)
+	require.ErrorIs(t, err, errPolicyTestsFailed)
+}
+
+// TestRunTestsEmptyProtoMatchesDefaultProtocols captures the bug where a
+// test entry with no `proto` field fails to match a filter rule whose
+// IPProto is restricted to a default protocol (TCP, UDP, ICMP, ICMPv6).
+// Tailscale's client default set is {6, 17, 1, 58} when proto is omitted,
+// so a TCP-only rule must satisfy an empty-proto test.
+//
+// The capture
+// testdata/policytest_results/policytest-allpass-acls-and-grants-mixed.hujson
+// is the captured signal for this same bug (api_response_code 200, two
+// passing tests including `tag:client → webserver:80` with no proto over
+// a `ip: tcp:80` grant).
+func TestRunTestsEmptyProtoMatchesDefaultProtocols(t *testing.T) {
+	users := types.Users{
+		{Model: gorm.Model{ID: 1}, Name: "odin", Email: "odin@example.com"},
+	}
+	nodes := types.Nodes{
+		{
+			ID:       1,
+			Hostname: "client",
+			IPv4:     ap("100.64.0.10"),
+			IPv6:     ap("fd7a:115c:a1e0::a"),
+			Tags:     []string{"tag:client"},
+		},
+		{
+			ID:       2,
+			Hostname: "webserver",
+			IPv4:     ap("100.64.0.16"),
+			IPv6:     ap("fd7a:115c:a1e0::10"),
+			Tags:     []string{"tag:server"},
+		},
+	}
+
+	policy := `{
+		"tagOwners": {
+			"tag:client": ["odin@example.com"],
+			"tag:server": ["odin@example.com"]
+		},
+		"hosts": {
+			"webserver": "100.64.0.16"
+		},
+		"grants": [
+			{"src": ["tag:client"], "dst": ["webserver"], "ip": ["tcp:80"]}
+		],
+		"tests": [
+			{"src": "tag:client", "accept": ["webserver:80"]}
+		]
+	}`
+
+	pm, err := NewPolicyManager([]byte(policy), users, nodes.ViewSlice())
+	require.NoError(t, err, "policy must parse and compile")
+
+	require.NoError(t, pm.RunTests(),
+		"empty-proto test must match a tcp-only grant rule (TCP is in the client default set)")
+}
+
+// TestPolicyTestResultsErrorsRendering checks the multi-line render layout
+// since the body becomes the user-facing error.
+func TestPolicyTestResultsErrorsRendering(t *testing.T) {
+	results := PolicyTestResults{
+		AllPassed: false,
+		Results: []PolicyTestResult{
+			{
+				Src:        "alice@headscale.net",
+				AcceptFail: []string{"tag:server:22"},
+			},
+			{
+				Src:      "bob@headscale.net",
+				Proto:    "tcp",
+				DenyFail: []string{"tag:server:443"},
+			},
+		},
+	}
+
+	rendered := results.Errors()
+	for _, sub := range []string{
+		"alice@headscale.net -> tag:server:22: expected ALLOWED, got DENIED",
+		"bob@headscale.net -> tag:server:443 (tcp): expected DENIED, got ALLOWED",
+	} {
+		assert.Contains(t, rendered, sub)
+	}
+
+	// Lines should be newline-separated, not space-joined.
+	assert.Equal(t, 2, strings.Count(rendered, "\n")+1, "expected one line per failing assertion")
+}