util: remove dead helpers and stale comments

hscontrol/util/dns.go

@@ -150,24 +150,6 @@ func GenerateIPv4DNSRootDomain(ipPrefix netip.Prefix) []dnsname.FQDN {
 	return fqdns
 }
 
-// generateMagicDNSRootDomains generates a list of DNS entries to be included in [tailcfg.DNSConfig.Routes] in [tailcfg.MapResponse].
-// This list of reverse DNS entries instructs the OS on what subnets and domains the Tailscale embedded DNS
-// server (listening in 100.100.100.100 udp/53) should be used for.
-//
-// Tailscale.com includes in the list:
-// - the [types.DNSConfig.BaseDomain] of the user
-// - the reverse DNS entry for IPv6 (0.e.1.a.c.5.1.1.a.7.d.f.ip6.arpa., see below more on IPv6)
-// - the reverse DNS entries for the IPv4 subnets covered by the user's `IPPrefix`.
-//   In the public SaaS this is [64-127].100.in-addr.arpa.
-//
-// The main purpose of this function is then generating the list of IPv4 entries. For the 100.64.0.0/10, this
-// is clear, and could be hardcoded. But we are allowing any range as `IPPrefix`, so we need to find out the
-// subnets when we have 172.16.0.0/16 (i.e., [0-255].16.172.in-addr.arpa.), or any other subnet.
-//
-// How IN-ADDR.ARPA domains work is defined in RFC1035 (section 3.5). Tailscale.com seems to adhere to this,
-// and do not make use of RFC2317 ("Classless IN-ADDR.ARPA delegation") - hence generating the entries for the next
-// class block only.
-
 // GenerateIPv6DNSRootDomain generates the IPv6 reverse DNS root domains.
 // From the netmask we can find out the wildcard bits (the bits that are not set in the netmask).
 // This allows us to then calculate the subnets included in the subsequent class block and generate the entries.
@@ -192,7 +174,8 @@ func GenerateIPv6DNSRootDomain(ipPrefix netip.Prefix) []dnsname.FQDN {
 	for i := range maskBits / nibbleLen {
 		prefixConstantParts = append(
 			[]string{string(nibbleStr[i])},
-			prefixConstantParts...)
+			prefixConstantParts...,
+		)
 	}
 
 	makeDomain := func(variablePrefix ...string) (dnsname.FQDN, error) {

hscontrol/util/log.go

@@ -32,19 +32,15 @@ type DBLogWrapper struct {
 }
 
 func NewDBLogWrapper(origin *zerolog.Logger, slowThreshold time.Duration, skipErrRecordNotFound bool, parameterizedQueries bool) *DBLogWrapper {
-	l := &DBLogWrapper{
+	return &DBLogWrapper{
 		Logger:                origin,
 		Level:                 origin.GetLevel(),
 		SlowThreshold:         slowThreshold,
 		SkipErrRecordNotFound: skipErrRecordNotFound,
 		ParameterizedQueries:  parameterizedQueries,
 	}
-
-	return l
 }
 
-type DBLogWrapperOption func(*DBLogWrapper)
-
 func (l *DBLogWrapper) LogMode(gormLogger.LogLevel) gormLogger.Interface {
 	return l
 }
@@ -71,16 +67,16 @@ func (l *DBLogWrapper) Trace(ctx context.Context, begin time.Time, fc func() (sq
 	}
 
 	if err != nil && (!errors.Is(err, gorm.ErrRecordNotFound) || !l.SkipErrRecordNotFound) {
-		l.Logger.Error().Err(err).Fields(fields).Msgf("")
+		l.Logger.Error().Err(err).Fields(fields).Msg("")
 		return
 	}
 
 	if l.SlowThreshold != 0 && elapsed > l.SlowThreshold {
-		l.Logger.Warn().Fields(fields).Msgf("")
+		l.Logger.Warn().Fields(fields).Msg("")
 		return
 	}
 
-	l.Logger.Debug().Fields(fields).Msgf("")
+	l.Logger.Debug().Fields(fields).Msg("")
 }
 
 func (l *DBLogWrapper) ParamsFilter(ctx context.Context, sql string, params ...any) (string, []any) {

hscontrol/util/string.go

@@ -3,10 +3,7 @@ package util
 import (
 	"crypto/rand"
 	"encoding/base64"
-	"fmt"
 	"strings"
-
-	"tailscale.com/tailcfg"
 )
 
 // GenerateRandomBytes returns securely generated random bytes.
@@ -79,40 +76,3 @@ func MustGenerateRandomStringDNSSafe(size int) string {
 
 	return hash
 }
-
-func TailNodesToString(nodes []*tailcfg.Node) string {
-	temp := make([]string, len(nodes))
-
-	for index, node := range nodes {
-		temp[index] = node.Name
-	}
-
-	return fmt.Sprintf("[ %s ](%d)", strings.Join(temp, ", "), len(temp))
-}
-
-func TailMapResponseToString(resp tailcfg.MapResponse) string {
-	return fmt.Sprintf(
-		"{ Node: %s, Peers: %s }",
-		resp.Node.Name,
-		TailNodesToString(resp.Peers),
-	)
-}
-
-func TailcfgFilterRulesToString(rules []tailcfg.FilterRule) string {
-	var sb strings.Builder
-
-	for index, rule := range rules {
-		fmt.Fprintf(&sb, `
-{
-  SrcIPs: %v
-  DstIPs: %v
-}
-`, rule.SrcIPs, rule.DstPorts)
-
-		if index < len(rules)-1 {
-			sb.WriteString(", ")
-		}
-	}
-
-	return fmt.Sprintf("[ %s ](%d)", sb.String(), len(rules))
-}