for all of ./...

This applies the `go fix` recommendations for go1.26

.github/workflows/smoke/smoke-windows.ps1

@@ -51,19 +51,15 @@ wsl -d $Distro -- bash -c "rm -rf $WslDir && mkdir -p $WslDir" | Out-Null
 $DevName = 'nebula-smoke'
 $Ip1 = '192.168.241.1'
 $Ip2 = '192.168.241.2'
-# Dual stack on purpose: a v4-only overlay never exercises the v6 side of tun.mtu.
-$Ip6_1 = 'fd42:4242:241::1'
-$Ip6_2 = 'fd42:4242:241::2'
-$Mtu = 1300
 $Port = 4242
 
 & $NebulaCert ca -name 'smoke-ca' -out-crt "$WorkDir\ca.crt" -out-key "$WorkDir\ca.key"
 if ($LASTEXITCODE -ne 0) { throw "nebula-cert ca failed (exit $LASTEXITCODE)" }
 
-& $NebulaCert sign -name 'lighthouse' -networks "$Ip1/24,$Ip6_1/64" -ca-crt "$WorkDir\ca.crt" -ca-key "$WorkDir\ca.key" -out-crt "$WorkDir\lighthouse.crt" -out-key "$WorkDir\lighthouse.key"
+& $NebulaCert sign -name 'lighthouse' -networks "$Ip1/24" -ca-crt "$WorkDir\ca.crt" -ca-key "$WorkDir\ca.key" -out-crt "$WorkDir\lighthouse.crt" -out-key "$WorkDir\lighthouse.key"
 if ($LASTEXITCODE -ne 0) { throw "nebula-cert sign lighthouse failed (exit $LASTEXITCODE)" }
 
-& $NebulaCert sign -name 'peer' -networks "$Ip2/24,$Ip6_2/64" -ca-crt "$WorkDir\ca.crt" -ca-key "$WorkDir\ca.key" -out-crt "$WorkDir\peer.crt" -out-key "$WorkDir\peer.key"
+& $NebulaCert sign -name 'peer' -networks "$Ip2/24" -ca-crt "$WorkDir\ca.crt" -ca-key "$WorkDir\ca.key" -out-crt "$WorkDir\peer.crt" -out-key "$WorkDir\peer.key"
 if ($LASTEXITCODE -ne 0) { throw "nebula-cert sign peer failed (exit $LASTEXITCODE)" }
 
 # Windows lighthouse config.
@@ -86,7 +82,7 @@ tun:
   drop_local_broadcast: false
   drop_multicast: false
   tx_queue: 500
-  mtu: $Mtu
+  mtu: 1300
   network_category: private
 logging:
   level: info
@@ -130,7 +126,7 @@ tun:
   drop_local_broadcast: false
   drop_multicast: false
   tx_queue: 500
-  mtu: $Mtu
+  mtu: 1300
 logging:
   level: info
   format: text
@@ -173,7 +169,7 @@ Write-Host '=== WSL diagnostic ==='
 wsl --version 2>&1 | Out-Host
 wsl --list --verbose 2>&1 | Out-Host
 wsl -d $Distro -u root -- uname -a | Out-Host
-wsl -d $Distro -u root -- bash -c "modprobe tun 2>&1 || true; mkdir -p /dev/net; [ -c /dev/net/tun ] || mknod /dev/net/tun c 10 200; chmod 600 /dev/net/tun; { echo 0 > /proc/sys/net/ipv6/conf/all/disable_ipv6; echo 0 > /proc/sys/net/ipv6/conf/default/disable_ipv6; } 2>/dev/null || true; ls -l /dev/net/tun"
+wsl -d $Distro -u root -- bash -c "modprobe tun 2>&1 || true; mkdir -p /dev/net; [ -c /dev/net/tun ] || mknod /dev/net/tun c 10 200; chmod 600 /dev/net/tun; ls -l /dev/net/tun"
 if ($LASTEXITCODE -ne 0) { throw "failed to prepare /dev/net/tun in WSL (TUN support missing?)" }
 
 # Deliberately no New-NetFirewallRule calls here -- nebula's windows_bypass_wdf
@@ -218,16 +214,6 @@ try {
     }
     Write-Host "OK: $DevName NetworkCategory=Private"
 
-    # v6 silently kept the adapter default of 65535 while v4 was correct.
-    foreach ($family in @('IPv4', 'IPv6')) {
-        Wait-Until -TimeoutSec 30 -What "$DevName $family NlMtu=$Mtu" -Predicate {
-            if ($lhProc.HasExited) { throw "lighthouse exited (code $($lhProc.ExitCode)) before $family mtu was set" }
-            $rows = @(Get-NetIPInterface -InterfaceAlias $DevName -AddressFamily $family -ErrorAction SilentlyContinue)
-            $rows.Count -gt 0 -and -not ($rows | Where-Object { $_.NlMtu -ne $Mtu })
-        }
-        Write-Host "OK: $DevName $family NlMtu=$Mtu"
-    }
-
     Wait-Until -TimeoutSec 30 -What "WSL nebula1 with $Ip2" -Predicate {
         if ($peerProc.HasExited) { throw "peer exited (code $($peerProc.ExitCode)) before tun was ready" }
         $r = wsl -d $Distro -u root -- bash -c "ip -o addr show nebula1 2>/dev/null | grep -q 'inet $Ip2' && echo yes"
@@ -235,13 +221,6 @@ try {
     }
     Write-Host "OK: WSL nebula1 has $Ip2"
 
-    Wait-Until -TimeoutSec 30 -What "WSL nebula1 with $Ip6_2" -Predicate {
-        if ($peerProc.HasExited) { throw "peer exited (code $($peerProc.ExitCode)) before the v6 address was up" }
-        $r = wsl -d $Distro -u root -- bash -c "ip -o addr show nebula1 2>/dev/null | grep -q 'inet6 $Ip6_2' && echo yes"
-        ("$r").Trim() -eq 'yes'
-    }
-    Write-Host "OK: WSL nebula1 has $Ip6_2"
-
     Wait-Until -TimeoutSec 30 -What "ping from WSL peer to windows lighthouse ($Ip1)" -Predicate {
         if ($peerProc.HasExited) { throw "peer exited (code $($peerProc.ExitCode)) before ping succeeded" }
         $r = wsl -d $Distro -u root -- bash -c "ping -c1 -W1 $Ip1 >/dev/null 2>&1 && echo OK"
@@ -255,14 +234,6 @@ try {
     }
     Write-Host "OK: windows lighthouse -> WSL peer"
 
-    # Otherwise the v6 networks only prove the interface exists, not that it forwards.
-    Wait-Until -TimeoutSec 30 -What "v6 ping from WSL peer to windows lighthouse ($Ip6_1)" -Predicate {
-        if ($peerProc.HasExited) { throw "peer exited (code $($peerProc.ExitCode)) before the v6 ping succeeded" }
-        $r = wsl -d $Distro -u root -- bash -c "ping -6 -c1 -W1 $Ip6_1 >/dev/null 2>&1 && echo OK"
-        ("$r").Trim() -eq 'OK'
-    }
-    Write-Host "OK: WSL peer -> windows lighthouse over v6"
-
     Write-Host ''
     Write-Host 'All smoke checks passed.'
 }

CHANGELOG.md

@@ -7,32 +7,6 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
-### Added
-
-- New `nebula ctl <command>` subcommand, which runs any of the debug and administrative commands the sshd
-  block exposes without requiring an ssh server, a host key, or authorized keys. Nebula serves them over a
-  local unix socket, configured by the new `ctl` block and enabled by default at `/run/nebula/ctl.sock` on
-  Linux and `/var/run/nebula/ctl.sock` elsewhere. The socket lives in a `0700` directory so filesystem
-  permissions are the access control; failing to create it is logged and never prevents nebula from
-  starting. Packagers running nebula under systemd will want `RuntimeDirectory=nebula` in the unit so the
-  directory exists with the right ownership. Not supported on Windows yet, and never enabled on iOS or
-  Android. Reloadable.
-
-### Changed
-
-- The ssh console now reports a real exit status for `ssh <host> <command>` rather than always reporting
-  success, so commands run that way are scriptable.
-- The debug and administrative commands moved out of `ssh.go` into `commands.go` and are no longer tied to
-  ssh: both the ssh console and `nebula ctl` dispatch against one shared registry, so a command added in
-  one place is available over both. Embedders of the `sshd` package are affected: `sshd.NewSSHServer` now
-  takes a `*diag.Registry`, `sshd.SSHServer.RegisterCommand` is gone in favor of registering on that
-  registry directly, and the command types now live in the `diag` package rather than being re-exported
-  from `sshd`.
-
-## [1.11.1] - 2026-08-21
-
-See the [v1.11.1](https://github.com/slackhq/nebula/milestone/30?closed=1) milestone for a complete list of changes.
-
 ### Changed
 
 - IPv6 packets whose next header is a protocol Nebula does not parse (SCTP, GRE, IP-in-IP, etc.) are now
@@ -41,18 +15,11 @@ See the [v1.11.1](https://github.com/slackhq/nebula/milestone/30?closed=1) miles
   their true protocol, so only a `proto: any` rule allows them. If you carry one of these protocols over the
   overlay, confirm a `proto: any` rule covers it before upgrading, it may have been passing only through this
   bypass. (#1840)
-- Drop the dependency on `github.com/cyberdelia/go-metrics-graphite`, which has been unmaintained for over ten
-  years, by inlining the small amount of code Nebula used. (#1832)
 
 ### Fixed
 
 - The ICMPv6 type was read from the wrong byte when classifying IPv6 packets, so the echo identifier used
   for conntrack was never picked up. (#1840)
-- Enforce outbound message counter limits so a tunnel is rehandshaked before the counter can wrap, preventing
-  nonce reuse. This is unreachable in practice, but is enforced as a defense-in-depth measure. (#1841)
-- Prevent `nebula-cert ca` from running out of memory on 32bit systems when generating encrypted private keys. (#1834)
-- Tolerate `ErrDumpInterrupted` when listing tun addresses on Linux, so a transient interrupted netlink dump
-  no longer aborts startup. (#1835)
 
 ## [1.11.0] - 2026-07-23
 
@@ -917,9 +884,7 @@ created.)
 
 - Initial public release.
 
-[Unreleased]: https://github.com/slackhq/nebula/compare/v1.11.1...HEAD
-[1.11.1]: https://github.com/slackhq/nebula/releases/tag/v1.11.1
-[1.11.0]: https://github.com/slackhq/nebula/releases/tag/v1.11.0
+[Unreleased]: https://github.com/slackhq/nebula/compare/v1.10.3...HEAD
 [1.10.3]: https://github.com/slackhq/nebula/releases/tag/v1.10.3
 [1.10.2]: https://github.com/slackhq/nebula/releases/tag/v1.10.2
 [1.10.1]: https://github.com/slackhq/nebula/releases/tag/v1.10.1

bits.go

@@ -79,13 +79,7 @@ func (b *Bits) clearRange(startPos, count uint64) uint64 {
 	// handle the potential partial word before pos becomes u64 aligned
 	word := pos >> 6
 	bit := pos & 63
-	take := uint64(64) - bit
-	if take > remaining {
-		take = remaining
-	}
-	if take > b.length-pos {
-		take = b.length - pos
-	}
+	take := min(min(uint64(64)-bit, remaining), b.length-pos)
 	var mask uint64
 	if take == 64 {
 		mask = math.MaxUint64
@@ -189,10 +183,7 @@ func (b *Bits) Update(l *slog.Logger, i uint64) bool {
 func (b *Bits) updateSlow(l *slog.Logger, i uint64) bool {
 	// If i is a jump, adjust the window, record lost, update current, and return true
 	if i > b.current {
-		end := i
-		if end > b.current+b.length {
-			end = b.current + b.length
-		}
+		end := min(i, b.current+b.length)
 		count := end - b.current
 		startPos := (b.current + 1) & b.lengthMask
 

cert/sign_test.go

@@ -120,7 +120,7 @@ func TestCertificate_SignP256_AlwaysNormalized(t *testing.T) {
 	pub := elliptic.Marshal(elliptic.P256(), priv.PublicKey.X, priv.PublicKey.Y)
 	rawPriv := priv.D.FillBytes(make([]byte, 32))
 
-	for i := 0; i < 1000; i++ {
+	for i := range 1000 {
 		if i&1 == 1 {
 			tbs.Version = Version1
 		} else {

cmd/nebula-cert/ca.go

@@ -151,7 +151,7 @@ func ca(args []string, out io.Writer, errOut io.Writer, pr PasswordReader) error
 
 	var groups []string
 	if *cf.groups != "" {
-		for _, rg := range strings.Split(*cf.groups, ",") {
+		for rg := range strings.SplitSeq(*cf.groups, ",") {
 			g := strings.TrimSpace(rg)
 			if g != "" {
 				groups = append(groups, g)
@@ -171,7 +171,7 @@ func ca(args []string, out io.Writer, errOut io.Writer, pr PasswordReader) error
 	}
 
 	if *cf.networks != "" {
-		for _, rs := range strings.Split(*cf.networks, ",") {
+		for rs := range strings.SplitSeq(*cf.networks, ",") {
 			rs := strings.Trim(rs, " ")
 			if rs != "" {
 				n, err := netip.ParsePrefix(rs)
@@ -193,7 +193,7 @@ func ca(args []string, out io.Writer, errOut io.Writer, pr PasswordReader) error
 	}
 
 	if *cf.unsafeNetworks != "" {
-		for _, rs := range strings.Split(*cf.unsafeNetworks, ",") {
+		for rs := range strings.SplitSeq(*cf.unsafeNetworks, ",") {
 			rs := strings.Trim(rs, " ")
 			if rs != "" {
 				n, err := netip.ParsePrefix(rs)
@@ -221,7 +221,7 @@ func ca(args []string, out io.Writer, errOut io.Writer, pr PasswordReader) error
 	if !isP11 && *cf.encryption {
 		passphrase = []byte(os.Getenv("NEBULA_CA_PASSPHRASE"))
 		if len(passphrase) == 0 {
-			for i := 0; i < 5; i++ {
+			for range 5 {
 				errOut.Write([]byte("Enter passphrase: "))
 				passphrase, err = pr.ReadPassword()
 

cmd/nebula-cert/ca_test.go

@@ -1,5 +1,4 @@
 //go:build !windows
-// +build !windows
 
 package main
 

cmd/nebula-cert/sign.go

@@ -146,7 +146,7 @@ func signCert(args []string, out io.Writer, errOut io.Writer, pr PasswordReader)
 			passphrase = []byte(os.Getenv("NEBULA_CA_PASSPHRASE"))
 			if len(passphrase) == 0 {
 				// ask for a passphrase until we get one
-				for i := 0; i < 5; i++ {
+				for range 5 {
 					errOut.Write([]byte("Enter passphrase: "))
 					passphrase, err = pr.ReadPassword()
 
@@ -203,7 +203,7 @@ func signCert(args []string, out io.Writer, errOut io.Writer, pr PasswordReader)
 	}
 
 	if *sf.networks != "" {
-		for _, rs := range strings.Split(*sf.networks, ",") {
+		for rs := range strings.SplitSeq(*sf.networks, ",") {
 			rs := strings.Trim(rs, " ")
 			if rs != "" {
 				n, err := netip.ParsePrefix(rs)
@@ -228,7 +228,7 @@ func signCert(args []string, out io.Writer, errOut io.Writer, pr PasswordReader)
 	}
 
 	if *sf.unsafeNetworks != "" {
-		for _, rs := range strings.Split(*sf.unsafeNetworks, ",") {
+		for rs := range strings.SplitSeq(*sf.unsafeNetworks, ",") {
 			rs := strings.Trim(rs, " ")
 			if rs != "" {
 				n, err := netip.ParsePrefix(rs)
@@ -247,7 +247,7 @@ func signCert(args []string, out io.Writer, errOut io.Writer, pr PasswordReader)
 
 	var groups []string
 	if *sf.groups != "" {
-		for _, rg := range strings.Split(*sf.groups, ",") {
+		for rg := range strings.SplitSeq(*sf.groups, ",") {
 			g := strings.TrimSpace(rg)
 			if g != "" {
 				groups = append(groups, g)

cmd/nebula-cert/sign_test.go

@@ -1,5 +1,4 @@
 //go:build !windows
-// +build !windows
 
 package main
 

cmd/nebula-service/logs_generic.go

@@ -1,5 +1,4 @@
 //go:build !windows
-// +build !windows
 
 package main
 

cmd/nebula/ctl.go

@@ -1,131 +0,0 @@
-package main
-
-import (
-	"errors"
-	"flag"
-	"fmt"
-	"io/fs"
-	"log/slog"
-	"os"
-	"syscall"
-
-	"github.com/slackhq/nebula/config"
-	"github.com/slackhq/nebula/diag"
-)
-
-// ctlMain implements `nebula ctl <command> [args...]`, which runs a debug command against the
-// nebula already running on this host. Everything after the command name is forwarded to that
-// nebula verbatim and parsed there by the same flag sets the ssh console uses, so this side
-// deliberately understands as little as possible about it.
-//
-// Returns the process exit status.
-func ctlMain(argv []string) int {
-	fl := flag.NewFlagSet("nebula ctl", flag.ContinueOnError)
-	fl.Usage = func() {
-		out := fl.Output()
-		fmt.Fprintf(out, "Usage: nebula ctl [-config path] [-socket path] <command> [arguments]\n\n")
-		fmt.Fprintf(out, "Runs a debug command against the running nebula on this host, over its local\n")
-		fmt.Fprintf(out, "control socket. Run `nebula ctl` with no command for the list of commands.\n\n")
-		fl.PrintDefaults()
-	}
-
-	socket := fl.String("socket", "", "Path to the control socket. Overrides ctl.socket from the config")
-	configPath := fl.String("config", "", "Path to the nebula config, read only to find ctl.socket")
-
-	// The flag package stops at the first non-flag argument, which is exactly the behaviour
-	// wanted here: `nebula ctl -socket /x list-hostmap -json` consumes -socket, stops at
-	// list-hostmap, and leaves the rest untouched for the daemon to parse.
-	if err := fl.Parse(argv); err != nil {
-		// -h is a request, not a failure.
-		if errors.Is(err, flag.ErrHelp) {
-			return diag.StatusOK
-		}
-		return diag.StatusUsage
-	}
-
-	path := *socket
-	if path == "" {
-		path = ctlSocketPath(*configPath)
-	}
-
-	if path == "" {
-		fmt.Fprintln(os.Stderr, "nebula ctl: no control socket path is known for this platform, set ctl.socket in the config")
-		return diag.StatusError
-	}
-
-	client, err := diag.Dial(path)
-	if err != nil {
-		fmt.Fprintln(os.Stderr, ctlDialError(path, err))
-		return diag.StatusError
-	}
-	defer client.Close()
-
-	args := fl.Args()
-	status, err := client.Run(args, os.Stdout)
-	if err != nil {
-		if errors.Is(err, diag.ErrTruncated) {
-			fmt.Fprintf(os.Stderr, "nebula ctl: nebula closed the connection before %s finished\n", ctlCommandName(args))
-			return diag.StatusError
-		}
-
-		fmt.Fprintf(os.Stderr, "nebula ctl: %s\n", err)
-		if status == diag.StatusOK {
-			return diag.StatusError
-		}
-	}
-
-	return status
-}
-
-// ctlSocketPath finds the socket to talk to. The platform default is the primary mechanism;
-// reading the config is the refinement for someone who moved the socket. It is best effort by
-// design, because config.DefaultPath resolves next to the nebula binary and a packaged install
-// keeps its config somewhere else entirely, so a config we cannot find is the normal case
-// rather than a failure.
-func ctlSocketPath(configPath string) string {
-	if configPath == "" {
-		p, err := config.DefaultPath()
-		if err != nil {
-			return diag.DefaultSocketPath()
-		}
-		configPath = p
-	}
-
-	c := config.NewC(slog.New(slog.DiscardHandler))
-	if err := c.Load(configPath); err != nil {
-		return diag.DefaultSocketPath()
-	}
-
-	return c.GetString("ctl.socket", diag.DefaultSocketPath())
-}
-
-// ctlDialError turns a connect failure into something an operator can act on. These messages
-// are the entire user experience when things are not working, so they name the path and say
-// what to check.
-func ctlDialError(path string, err error) string {
-	switch {
-	case errors.Is(err, diag.ErrNotSupported):
-		return "nebula ctl is not supported on this platform yet"
-
-	case errors.Is(err, fs.ErrNotExist):
-		return fmt.Sprintf("nebula ctl: no control socket at %s. Is nebula running? Is ctl.enabled set to false, or ctl.socket set to another path?", path)
-
-	case errors.Is(err, syscall.ECONNREFUSED):
-		return fmt.Sprintf("nebula ctl: found a stale socket at %s, nebula is not listening on it", path)
-
-	case errors.Is(err, fs.ErrPermission):
-		return fmt.Sprintf("nebula ctl: permission denied opening %s. nebula ctl must run as the user nebula runs as, usually root", path)
-
-	default:
-		return fmt.Sprintf("nebula ctl: %s", err)
-	}
-}
-
-// ctlCommandName names the command for an error message, for the case where there isn't one.
-func ctlCommandName(args []string) string {
-	if len(args) == 0 {
-		return "the command"
-	}
-
-	return args[0]
-}

cmd/nebula/ctl_test.go

@@ -1,70 +0,0 @@
-package main
-
-import (
-	"errors"
-	"io/fs"
-	"os"
-	"path/filepath"
-	"syscall"
-	"testing"
-
-	"github.com/slackhq/nebula/diag"
-	"github.com/stretchr/testify/assert"
-	"github.com/stretchr/testify/require"
-)
-
-// The daemon parses the command's own flags, so this side must consume its own and forward
-// everything from the command name onwards untouched.
-func TestCtlSocketPath(t *testing.T) {
-	t.Run("a config naming a socket is used", func(t *testing.T) {
-		dir := t.TempDir()
-		path := filepath.Join(dir, "config.yml")
-		require.NoError(t, os.WriteFile(path, []byte("ctl:\n  socket: /run/somewhere/ctl.sock\n"), 0600))
-
-		assert.Equal(t, "/run/somewhere/ctl.sock", ctlSocketPath(path))
-	})
-
-	t.Run("a config without a ctl block falls back to the platform default", func(t *testing.T) {
-		dir := t.TempDir()
-		path := filepath.Join(dir, "config.yml")
-		require.NoError(t, os.WriteFile(path, []byte("pki:\n  ca: /dev/null\n"), 0600))
-
-		assert.Equal(t, diag.DefaultSocketPath(), ctlSocketPath(path))
-	})
-
-	// A packaged install keeps its config somewhere config.DefaultPath will never look, so a
-	// config we cannot read is the ordinary case and must not be fatal.
-	t.Run("an unreadable config falls back to the platform default", func(t *testing.T) {
-		assert.Equal(t, diag.DefaultSocketPath(), ctlSocketPath(filepath.Join(t.TempDir(), "nope.yml")))
-	})
-}
-
-func TestCtlDialError(t *testing.T) {
-	tests := []struct {
-		name  string
-		err   error
-		wants string
-	}{
-		{"missing socket names the path and what to check", fs.ErrNotExist, "no control socket at /x/ctl.sock. Is nebula running?"},
-		{"a stale socket is called stale", syscall.ECONNREFUSED, "found a stale socket at /x/ctl.sock"},
-		{"permission denied suggests the right user", fs.ErrPermission, "must run as the user nebula runs as"},
-		{"an unsupported platform says so", diag.ErrNotSupported, "not supported on this platform"},
-		{"anything else is reported verbatim", errors.New("something else"), "something else"},
-	}
-
-	for _, tt := range tests {
-		t.Run(tt.name, func(t *testing.T) {
-			assert.Contains(t, ctlDialError("/x/ctl.sock", tt.err), tt.wants)
-		})
-	}
-
-	t.Run("a wrapped syscall error is still recognised", func(t *testing.T) {
-		err := &os.SyscallError{Syscall: "connect", Err: syscall.ECONNREFUSED}
-		assert.Contains(t, ctlDialError("/x/ctl.sock", err), "stale socket")
-	})
-}
-
-func TestCtlCommandName(t *testing.T) {
-	assert.Equal(t, "print-cert", ctlCommandName([]string{"print-cert", "-json"}))
-	assert.Equal(t, "the command", ctlCommandName(nil))
-}

cmd/nebula/main.go

@@ -32,26 +32,11 @@ func init() {
 }
 
 func main() {
-	// Subcommands are dispatched before flag.Parse, because flag.Parse stops at the first
-	// non-flag argument and everything after `ctl` has to reach the running nebula's own flag
-	// parser untouched. Nothing here looks at -json or a vpn address.
-	if len(os.Args) > 1 && os.Args[1] == "ctl" {
-		os.Exit(ctlMain(os.Args[2:]))
-	}
-
 	configPath := flag.String("config", "", "Path to either a file or directory to load configuration from")
 	configTest := flag.Bool("test", false, "Test the config and print the end result. Non zero exit indicates a faulty config")
 	printVersion := flag.Bool("version", false, "Print version")
 	printUsage := flag.Bool("help", false, "Print command line usage")
 
-	flag.Usage = func() {
-		out := flag.CommandLine.Output()
-		fmt.Fprintf(out, "Usage of %s:\n", os.Args[0])
-		flag.PrintDefaults()
-		fmt.Fprintf(out, "\nCommands:\n")
-		fmt.Fprintf(out, "  ctl [command]\n\tRun a debug command against the running nebula on this host.\n\tRun `nebula ctl` on its own for the list of commands.\n")
-	}
-
 	flag.Parse()
 
 	if *printVersion {

cmd/nebula/notify_notlinux.go

@@ -1,5 +1,4 @@
 //go:build !linux
-// +build !linux
 
 package main
 

commands.go

@@ -1,922 +0,0 @@
-package nebula
-
-// The commands nebula exposes for debugging and administration. They are transport neutral:
-// the ssh console in ssh.go and the `nebula ctl` socket in ctl.go both dispatch against the
-// registry attachCommands fills in, and a command cannot tell which one invoked it. Adding a
-// command here makes it available over both.
-
-import (
-	"bytes"
-	"encoding/json"
-	"errors"
-	"flag"
-	"fmt"
-	"log/slog"
-	"maps"
-	"net/netip"
-	"os"
-	"path/filepath"
-	"runtime"
-	"runtime/pprof"
-	"sort"
-	"strconv"
-	"strings"
-
-	"github.com/slackhq/nebula/config"
-	"github.com/slackhq/nebula/diag"
-	"github.com/slackhq/nebula/header"
-	"github.com/slackhq/nebula/logging"
-)
-
-type listHostMapFlags struct {
-	Json    bool
-	Pretty  bool
-	ByIndex bool
-}
-
-type printCertFlags struct {
-	Json   bool
-	Pretty bool
-	Raw    bool
-}
-
-type printTunnelFlags struct {
-	Pretty bool
-}
-
-type changeRemoteFlags struct {
-	Address string
-}
-
-type closeTunnelFlags struct {
-	LocalOnly bool
-}
-
-type createTunnelFlags struct {
-	Address string
-}
-
-type deviceInfoFlags struct {
-	Json   bool
-	Pretty bool
-}
-
-func attachCommands(l *slog.Logger, c *config.C, reg *diag.Registry, f *Interface) {
-	// sandboxDir defaults to a dir in temp. The intention is that end user will
-	// create this dir as needed. Overriding this config value to "" allows
-	// writing to anywhere in the system.
-	defaultDir := filepath.Join(os.TempDir(), "nebula-debug")
-	// The key is spelled for both transports now: the profile writers are reachable over
-	// `nebula ctl` as well, but sshd.sandbox_dir keeps working for anyone already setting it.
-	sandboxDir := c.GetString("ctl.sandbox_dir", c.GetString("sshd.sandbox_dir", defaultDir))
-
-	reg.RegisterCommand(&diag.Command{
-		Name:             "list-hostmap",
-		ShortDescription: "List all known previously connected hosts",
-		Flags: func() (*flag.FlagSet, any) {
-			fl := flag.NewFlagSet("", flag.ContinueOnError)
-			s := listHostMapFlags{}
-			fl.BoolVar(&s.Json, "json", false, "outputs as json with more information")
-			fl.BoolVar(&s.Pretty, "pretty", false, "pretty prints json, assumes -json")
-			fl.BoolVar(&s.ByIndex, "by-index", false, "gets all hosts in the hostmap from the index table")
-			return fl, &s
-		},
-		Callback: func(fs any, a []string, w diag.StringWriter) error {
-			return cmdListHostMap(f.hostMap, fs, w)
-		},
-	})
-
-	reg.RegisterCommand(&diag.Command{
-		Name:             "list-pending-hostmap",
-		ShortDescription: "List all handshaking hosts",
-		Flags: func() (*flag.FlagSet, any) {
-			fl := flag.NewFlagSet("", flag.ContinueOnError)
-			s := listHostMapFlags{}
-			fl.BoolVar(&s.Json, "json", false, "outputs as json with more information")
-			fl.BoolVar(&s.Pretty, "pretty", false, "pretty prints json, assumes -json")
-			fl.BoolVar(&s.ByIndex, "by-index", false, "gets all hosts in the hostmap from the index table")
-			return fl, &s
-		},
-		Callback: func(fs any, a []string, w diag.StringWriter) error {
-			return cmdListHostMap(f.handshakeManager, fs, w)
-		},
-	})
-
-	reg.RegisterCommand(&diag.Command{
-		Name:             "list-lighthouse-addrmap",
-		ShortDescription: "List all lighthouse map entries",
-		Flags: func() (*flag.FlagSet, any) {
-			fl := flag.NewFlagSet("", flag.ContinueOnError)
-			s := listHostMapFlags{}
-			fl.BoolVar(&s.Json, "json", false, "outputs as json with more information")
-			fl.BoolVar(&s.Pretty, "pretty", false, "pretty prints json, assumes -json")
-			return fl, &s
-		},
-		Callback: func(fs any, a []string, w diag.StringWriter) error {
-			return cmdListLighthouseMap(f.lightHouse, fs, w)
-		},
-	})
-
-	reg.RegisterCommand(&diag.Command{
-		Name:             "reload",
-		ShortDescription: "Reloads configuration from disk, same as sending HUP to the process",
-		Callback: func(fs any, a []string, w diag.StringWriter) error {
-			return cmdReload(c, w)
-		},
-	})
-
-	reg.RegisterCommand(&diag.Command{
-		Name:             "start-cpu-profile",
-		ShortDescription: "Starts a cpu profile and write output to the provided file, ex: `cpu-profile.pb.gz`",
-		Callback: func(fs any, a []string, w diag.StringWriter) error {
-			return cmdStartCpuProfile(sandboxDir, fs, a, w)
-		},
-	})
-
-	reg.RegisterCommand(&diag.Command{
-		Name:             "stop-cpu-profile",
-		ShortDescription: "Stops a cpu profile and writes output to the previously provided file",
-		Callback: func(fs any, a []string, w diag.StringWriter) error {
-			pprof.StopCPUProfile()
-			return w.WriteLine("If a CPU profile was running it is now stopped")
-		},
-	})
-
-	reg.RegisterCommand(&diag.Command{
-		Name:             "save-heap-profile",
-		ShortDescription: "Saves a heap profile to the provided path, ex: `heap-profile.pb.gz`",
-		Callback: func(fs any, a []string, w diag.StringWriter) error {
-			return cmdGetHeapProfile(sandboxDir, fs, a, w)
-		},
-	})
-
-	reg.RegisterCommand(&diag.Command{
-		Name:             "mutex-profile-fraction",
-		ShortDescription: "Gets or sets runtime.SetMutexProfileFraction",
-		Callback:         cmdMutexProfileFraction,
-	})
-
-	reg.RegisterCommand(&diag.Command{
-		Name:             "save-mutex-profile",
-		ShortDescription: "Saves a mutex profile to the provided path, ex: `mutex-profile.pb.gz`",
-		Callback: func(fs any, a []string, w diag.StringWriter) error {
-			return cmdGetMutexProfile(sandboxDir, fs, a, w)
-		},
-	})
-
-	reg.RegisterCommand(&diag.Command{
-		Name:             "log-level",
-		ShortDescription: "Gets or sets the current log level",
-		Callback: func(fs any, a []string, w diag.StringWriter) error {
-			return cmdLogLevel(l, fs, a, w)
-		},
-	})
-
-	reg.RegisterCommand(&diag.Command{
-		Name:             "log-format",
-		ShortDescription: "Gets or sets the current log format",
-		Callback: func(fs any, a []string, w diag.StringWriter) error {
-			return cmdLogFormat(l, fs, a, w)
-		},
-	})
-
-	reg.RegisterCommand(&diag.Command{
-		Name:             "version",
-		ShortDescription: "Prints the currently running version of nebula",
-		Callback: func(fs any, a []string, w diag.StringWriter) error {
-			return cmdVersion(f, fs, a, w)
-		},
-	})
-
-	reg.RegisterCommand(&diag.Command{
-		Name:             "device-info",
-		ShortDescription: "Prints information about the network device.",
-		Flags: func() (*flag.FlagSet, any) {
-			fl := flag.NewFlagSet("", flag.ContinueOnError)
-			s := deviceInfoFlags{}
-			fl.BoolVar(&s.Json, "json", false, "outputs as json with more information")
-			fl.BoolVar(&s.Pretty, "pretty", false, "pretty prints json, assumes -json")
-			return fl, &s
-		},
-		Callback: func(fs any, a []string, w diag.StringWriter) error {
-			return cmdDeviceInfo(f, fs, w)
-		},
-	})
-
-	reg.RegisterCommand(&diag.Command{
-		Name:             "print-cert",
-		ShortDescription: "Prints the current certificate being used or the certificate for the provided vpn addr",
-		Flags: func() (*flag.FlagSet, any) {
-			fl := flag.NewFlagSet("", flag.ContinueOnError)
-			s := printCertFlags{}
-			fl.BoolVar(&s.Json, "json", false, "outputs as json")
-			fl.BoolVar(&s.Pretty, "pretty", false, "pretty prints json, assumes -json")
-			fl.BoolVar(&s.Raw, "raw", false, "raw prints the PEM encoded certificate, not compatible with -json or -pretty")
-			return fl, &s
-		},
-		Callback: func(fs any, a []string, w diag.StringWriter) error {
-			return cmdPrintCert(f, fs, a, w)
-		},
-	})
-
-	reg.RegisterCommand(&diag.Command{
-		Name:             "print-tunnel",
-		ShortDescription: "Prints json details about a tunnel for the provided vpn addr",
-		Flags: func() (*flag.FlagSet, any) {
-			fl := flag.NewFlagSet("", flag.ContinueOnError)
-			s := printTunnelFlags{}
-			fl.BoolVar(&s.Pretty, "pretty", false, "pretty prints json")
-			return fl, &s
-		},
-		Callback: func(fs any, a []string, w diag.StringWriter) error {
-			return cmdPrintTunnel(f, fs, a, w)
-		},
-	})
-
-	reg.RegisterCommand(&diag.Command{
-		Name:             "print-relays",
-		ShortDescription: "Prints json details about all relay info",
-		Flags: func() (*flag.FlagSet, any) {
-			fl := flag.NewFlagSet("", flag.ContinueOnError)
-			s := printTunnelFlags{}
-			fl.BoolVar(&s.Pretty, "pretty", false, "pretty prints json")
-			return fl, &s
-		},
-		Callback: func(fs any, a []string, w diag.StringWriter) error {
-			return cmdPrintRelays(f, fs, a, w)
-		},
-	})
-
-	reg.RegisterCommand(&diag.Command{
-		Name:             "change-remote",
-		ShortDescription: "Changes the remote address used in the tunnel for the provided vpn addr",
-		Flags: func() (*flag.FlagSet, any) {
-			fl := flag.NewFlagSet("", flag.ContinueOnError)
-			s := changeRemoteFlags{}
-			fl.StringVar(&s.Address, "address", "", "The new remote address, ip:port")
-			return fl, &s
-		},
-		Callback: func(fs any, a []string, w diag.StringWriter) error {
-			return cmdChangeRemote(f, fs, a, w)
-		},
-	})
-
-	reg.RegisterCommand(&diag.Command{
-		Name:             "close-tunnel",
-		ShortDescription: "Closes a tunnel for the provided vpn addr",
-		Flags: func() (*flag.FlagSet, any) {
-			fl := flag.NewFlagSet("", flag.ContinueOnError)
-			s := closeTunnelFlags{}
-			fl.BoolVar(&s.LocalOnly, "local-only", false, "Disables notifying the remote that the tunnel is shutting down")
-			return fl, &s
-		},
-		Callback: func(fs any, a []string, w diag.StringWriter) error {
-			return cmdCloseTunnel(f, fs, a, w)
-		},
-	})
-
-	reg.RegisterCommand(&diag.Command{
-		Name:             "create-tunnel",
-		ShortDescription: "Creates a tunnel for the provided vpn address",
-		Help:             "The lighthouses will be queried for real addresses but you can provide one as well.",
-		Flags: func() (*flag.FlagSet, any) {
-			fl := flag.NewFlagSet("", flag.ContinueOnError)
-			s := createTunnelFlags{}
-			fl.StringVar(&s.Address, "address", "", "Optionally provide a real remote address, ip:port ")
-			return fl, &s
-		},
-		Callback: func(fs any, a []string, w diag.StringWriter) error {
-			return cmdCreateTunnel(f, fs, a, w)
-		},
-	})
-
-	reg.RegisterCommand(&diag.Command{
-		Name:             "query-lighthouse",
-		ShortDescription: "Query the lighthouses for the provided vpn address",
-		Help:             "This command is asynchronous. Only currently known udp addresses will be printed.",
-		Callback: func(fs any, a []string, w diag.StringWriter) error {
-			return cmdQueryLighthouse(f, fs, a, w)
-		},
-	})
-}
-
-func cmdListHostMap(hl controlHostLister, a any, w diag.StringWriter) error {
-	fs, ok := a.(*listHostMapFlags)
-	if !ok {
-		return fmt.Errorf("internal error: expected flags to be listHostMapFlags but was %+v", a)
-	}
-
-	var hm []ControlHostInfo
-	if fs.ByIndex {
-		hm = listHostMapIndexes(hl)
-	} else {
-		hm = listHostMapHosts(hl)
-	}
-
-	sort.Slice(hm, func(i, j int) bool {
-		return hm[i].VpnAddrs[0].Compare(hm[j].VpnAddrs[0]) < 0
-	})
-
-	if fs.Json || fs.Pretty {
-		js := json.NewEncoder(w.GetWriter())
-		if fs.Pretty {
-			js.SetIndent("", "    ")
-		}
-
-		err := js.Encode(hm)
-		if err != nil {
-			return nil
-		}
-
-	} else {
-		for _, v := range hm {
-			err := w.WriteLine(fmt.Sprintf("%s: %s", v.VpnAddrs, v.RemoteAddrs))
-			if err != nil {
-				return err
-			}
-		}
-	}
-
-	return nil
-}
-
-func cmdListLighthouseMap(lightHouse *LightHouse, a any, w diag.StringWriter) error {
-	fs, ok := a.(*listHostMapFlags)
-	if !ok {
-		return fmt.Errorf("internal error: expected flags to be listHostMapFlags but was %+v", a)
-	}
-
-	type lighthouseInfo struct {
-		VpnAddr string    `json:"vpnAddr"`
-		Addrs   *CacheMap `json:"addrs"`
-	}
-
-	lightHouse.RLock()
-	addrMap := make([]lighthouseInfo, len(lightHouse.addrMap))
-	x := 0
-	for k, v := range lightHouse.addrMap {
-		addrMap[x] = lighthouseInfo{
-			VpnAddr: k.String(),
-			Addrs:   v.CopyCache(),
-		}
-		x++
-	}
-	lightHouse.RUnlock()
-
-	sort.Slice(addrMap, func(i, j int) bool {
-		return strings.Compare(addrMap[i].VpnAddr, addrMap[j].VpnAddr) < 0
-	})
-
-	if fs.Json || fs.Pretty {
-		js := json.NewEncoder(w.GetWriter())
-		if fs.Pretty {
-			js.SetIndent("", "    ")
-		}
-
-		err := js.Encode(addrMap)
-		if err != nil {
-			return nil
-		}
-
-	} else {
-		for _, v := range addrMap {
-			b, err := json.Marshal(v.Addrs)
-			if err != nil {
-				return err
-			}
-			err = w.WriteLine(fmt.Sprintf("%s: %s", v.VpnAddr, string(b)))
-			if err != nil {
-				return err
-			}
-		}
-	}
-
-	return nil
-}
-
-// sanitizeFilePath validates that the given file path is within the sandbox directory.
-// If sandboxDir is empty, the path is returned as-is for backwards compatibility.
-func sanitizeFilePath(sandboxDir, filePath string) (string, error) {
-	if sandboxDir == "" {
-		return filePath, nil
-	}
-
-	// Clean and resolve the path relative to the sandbox directory
-	if !filepath.IsAbs(filePath) {
-		filePath = filepath.Join(sandboxDir, filePath)
-	}
-	cleaned := filepath.Clean(filePath)
-
-	// Ensure the resolved path is within the sandbox directory
-	cleanedSandbox := filepath.Clean(sandboxDir)
-	if cleaned == cleanedSandbox {
-		return "", fmt.Errorf("path %q resolves to the sandbox directory itself %q", filePath, sandboxDir)
-	}
-	if !strings.HasPrefix(cleaned, cleanedSandbox+string(filepath.Separator)) {
-		return "", fmt.Errorf("path %q is outside the sandbox directory %q", filePath, sandboxDir)
-	}
-
-	return cleaned, nil
-}
-
-func cmdStartCpuProfile(sandboxDir string, fs any, a []string, w diag.StringWriter) error {
-	if len(a) == 0 {
-		err := w.WriteLine("No path to write profile provided")
-		return err
-	}
-
-	filePath, err := sanitizeFilePath(sandboxDir, a[0])
-	if err != nil {
-		return w.WriteLine(err.Error())
-	}
-
-	file, err := os.Create(filePath)
-	if err != nil {
-		err = w.WriteLine(fmt.Sprintf("Unable to create profile file: %s", err))
-		return err
-	}
-
-	err = pprof.StartCPUProfile(file)
-	if err != nil {
-		err = w.WriteLine(fmt.Sprintf("Unable to start cpu profile: %s", err))
-		return err
-	}
-
-	err = w.WriteLine(fmt.Sprintf("Started cpu profile, issue stop-cpu-profile to write the output to %s", a))
-	return err
-}
-
-func cmdVersion(ifce *Interface, fs any, a []string, w diag.StringWriter) error {
-	return w.WriteLine(fmt.Sprintf("%s", ifce.version))
-}
-
-func cmdQueryLighthouse(ifce *Interface, fs any, a []string, w diag.StringWriter) error {
-	if len(a) == 0 {
-		return w.WriteLine("No vpn address was provided")
-	}
-
-	vpnAddr, err := netip.ParseAddr(a[0])
-	if err != nil {
-		return w.WriteLine(fmt.Sprintf("The provided vpn address could not be parsed: %s", a[0]))
-	}
-
-	if !vpnAddr.IsValid() {
-		return w.WriteLine(fmt.Sprintf("The provided vpn address could not be parsed: %s", a[0]))
-	}
-
-	var cm *CacheMap
-	rl := ifce.lightHouse.Query(vpnAddr)
-	if rl != nil {
-		cm = rl.CopyCache()
-	}
-	return json.NewEncoder(w.GetWriter()).Encode(cm)
-}
-
-func cmdCloseTunnel(ifce *Interface, fs any, a []string, w diag.StringWriter) error {
-	flags, ok := fs.(*closeTunnelFlags)
-	if !ok {
-		return fmt.Errorf("internal error: expected flags to be closeTunnelFlags but was %+v", fs)
-	}
-
-	if len(a) == 0 {
-		return w.WriteLine("No vpn address was provided")
-	}
-
-	vpnAddr, err := netip.ParseAddr(a[0])
-	if err != nil {
-		return w.WriteLine(fmt.Sprintf("The provided vpn address could not be parsed: %s", a[0]))
-	}
-
-	if !vpnAddr.IsValid() {
-		return w.WriteLine(fmt.Sprintf("The provided vpn address could not be parsed: %s", a[0]))
-	}
-
-	hostInfo := ifce.hostMap.QueryVpnAddr(vpnAddr)
-	if hostInfo == nil {
-		return w.WriteLine(fmt.Sprintf("Could not find tunnel for vpn address: %v", a[0]))
-	}
-
-	if !flags.LocalOnly {
-		ifce.send(
-			header.CloseTunnel,
-			0,
-			hostInfo.ConnectionState,
-			hostInfo,
-			[]byte{},
-			make([]byte, 12, 12),
-			make([]byte, mtu),
-		)
-	}
-
-	ifce.closeTunnel(hostInfo)
-	return w.WriteLine("Closed")
-}
-
-func cmdCreateTunnel(ifce *Interface, fs any, a []string, w diag.StringWriter) error {
-	flags, ok := fs.(*createTunnelFlags)
-	if !ok {
-		return fmt.Errorf("internal error: expected flags to be createTunnelFlags but was %+v", fs)
-	}
-
-	if len(a) == 0 {
-		return w.WriteLine("No vpn address was provided")
-	}
-
-	vpnAddr, err := netip.ParseAddr(a[0])
-	if err != nil {
-		return w.WriteLine(fmt.Sprintf("The provided vpn address could not be parsed: %s", a[0]))
-	}
-
-	if !vpnAddr.IsValid() {
-		return w.WriteLine(fmt.Sprintf("The provided vpn address could not be parsed: %s", a[0]))
-	}
-
-	hostInfo := ifce.hostMap.QueryVpnAddr(vpnAddr)
-	if hostInfo != nil {
-		return w.WriteLine(fmt.Sprintf("Tunnel already exists"))
-	}
-
-	hostInfo = ifce.handshakeManager.QueryVpnAddr(vpnAddr)
-	if hostInfo != nil {
-		return w.WriteLine(fmt.Sprintf("Tunnel already handshaking"))
-	}
-
-	var addr netip.AddrPort
-	if flags.Address != "" {
-		addr, err = netip.ParseAddrPort(flags.Address)
-		if err != nil {
-			return w.WriteLine("Address could not be parsed")
-		}
-	}
-
-	hostInfo = ifce.handshakeManager.StartHandshake(vpnAddr, nil)
-	if addr.IsValid() {
-		hostInfo.SetRemote(addr)
-	}
-
-	return w.WriteLine("Created")
-}
-
-func cmdChangeRemote(ifce *Interface, fs any, a []string, w diag.StringWriter) error {
-	flags, ok := fs.(*changeRemoteFlags)
-	if !ok {
-		return fmt.Errorf("internal error: expected flags to be changeRemoteFlags but was %+v", fs)
-	}
-
-	if len(a) == 0 {
-		return w.WriteLine("No vpn address was provided")
-	}
-
-	if flags.Address == "" {
-		return w.WriteLine("No address was provided")
-	}
-
-	addr, err := netip.ParseAddrPort(flags.Address)
-	if err != nil {
-		return w.WriteLine("Address could not be parsed")
-	}
-
-	vpnAddr, err := netip.ParseAddr(a[0])
-	if err != nil {
-		return w.WriteLine(fmt.Sprintf("The provided vpn address could not be parsed: %s", a[0]))
-	}
-
-	if !vpnAddr.IsValid() {
-		return w.WriteLine(fmt.Sprintf("The provided vpn address could not be parsed: %s", a[0]))
-	}
-
-	hostInfo := ifce.hostMap.QueryVpnAddr(vpnAddr)
-	if hostInfo == nil {
-		return w.WriteLine(fmt.Sprintf("Could not find tunnel for vpn address: %v", a[0]))
-	}
-
-	hostInfo.SetRemote(addr)
-	return w.WriteLine("Changed")
-}
-
-func cmdGetHeapProfile(sandboxDir string, fs any, a []string, w diag.StringWriter) error {
-	if len(a) == 0 {
-		return w.WriteLine("No path to write profile provided")
-	}
-
-	filePath, err := sanitizeFilePath(sandboxDir, a[0])
-	if err != nil {
-		return w.WriteLine(err.Error())
-	}
-
-	file, err := os.Create(filePath)
-	if err != nil {
-		err = w.WriteLine(fmt.Sprintf("Unable to create profile file: %s", err))
-		return err
-	}
-
-	err = pprof.WriteHeapProfile(file)
-	if err != nil {
-		err = w.WriteLine(fmt.Sprintf("Unable to write profile: %s", err))
-		return err
-	}
-
-	err = w.WriteLine(fmt.Sprintf("Mem profile created at %s", a))
-	return err
-}
-
-func cmdMutexProfileFraction(fs any, a []string, w diag.StringWriter) error {
-	if len(a) == 0 {
-		rate := runtime.SetMutexProfileFraction(-1)
-		return w.WriteLine(fmt.Sprintf("Current value: %d", rate))
-	}
-
-	newRate, err := strconv.Atoi(a[0])
-	if err != nil {
-		return w.WriteLine(fmt.Sprintf("Invalid argument: %s", a[0]))
-	}
-
-	oldRate := runtime.SetMutexProfileFraction(newRate)
-	return w.WriteLine(fmt.Sprintf("New value: %d. Old value: %d", newRate, oldRate))
-}
-
-func cmdGetMutexProfile(sandboxDir string, fs any, a []string, w diag.StringWriter) error {
-	if len(a) == 0 {
-		return w.WriteLine("No path to write profile provided")
-	}
-
-	filePath, err := sanitizeFilePath(sandboxDir, a[0])
-	if err != nil {
-		return w.WriteLine(err.Error())
-	}
-
-	file, err := os.Create(filePath)
-	if err != nil {
-		return w.WriteLine(fmt.Sprintf("Unable to create profile file: %s", err))
-	}
-	defer file.Close()
-
-	mutexProfile := pprof.Lookup("mutex")
-	if mutexProfile == nil {
-		return w.WriteLine("Unable to get pprof.Lookup(\"mutex\")")
-	}
-
-	err = mutexProfile.WriteTo(file, 0)
-	if err != nil {
-		return w.WriteLine(fmt.Sprintf("Unable to write profile: %s", err))
-	}
-
-	return w.WriteLine(fmt.Sprintf("Mutex profile created at %s", a))
-}
-
-func cmdLogLevel(l *slog.Logger, fs any, a []string, w diag.StringWriter) error {
-	ctrl, ok := l.Handler().(interface {
-		GetLevel() slog.Level
-		SetLevel(slog.Level)
-	})
-	if !ok {
-		return w.WriteLine("Log level is not reconfigurable on this logger")
-	}
-
-	if len(a) == 0 {
-		return w.WriteLine(fmt.Sprintf("Log level is: %s", logging.LevelName(ctrl.GetLevel())))
-	}
-
-	level, err := logging.ParseLevel(strings.ToLower(a[0]))
-	if err != nil {
-		return w.WriteLine(fmt.Sprintf("Unknown log level %s. Possible log levels: trace, debug, info, warn, error", a))
-	}
-
-	ctrl.SetLevel(level)
-	return w.WriteLine(fmt.Sprintf("Log level is: %s", logging.LevelName(ctrl.GetLevel())))
-}
-
-func cmdLogFormat(l *slog.Logger, fs any, a []string, w diag.StringWriter) error {
-	ctrl, ok := l.Handler().(interface {
-		GetFormat() string
-		SetFormat(string) error
-	})
-	if !ok {
-		return w.WriteLine("Log format is not reconfigurable on this logger")
-	}
-
-	if len(a) == 0 {
-		return w.WriteLine(fmt.Sprintf("Log format is: %s", ctrl.GetFormat()))
-	}
-
-	if err := ctrl.SetFormat(strings.ToLower(a[0])); err != nil {
-		return err
-	}
-	return w.WriteLine(fmt.Sprintf("Log format is: %s", ctrl.GetFormat()))
-}
-
-func cmdPrintCert(ifce *Interface, fs any, a []string, w diag.StringWriter) error {
-	args, ok := fs.(*printCertFlags)
-	if !ok {
-		return fmt.Errorf("internal error: expected flags to be printCertFlags but was %+v", fs)
-	}
-
-	cert := ifce.pki.getCertState().GetDefaultCertificate()
-	if len(a) > 0 {
-		vpnAddr, err := netip.ParseAddr(a[0])
-		if err != nil {
-			return w.WriteLine(fmt.Sprintf("The provided vpn addr could not be parsed: %s", a[0]))
-		}
-
-		if !vpnAddr.IsValid() {
-			return w.WriteLine(fmt.Sprintf("The provided vpn addr could not be parsed: %s", a[0]))
-		}
-
-		hostInfo := ifce.hostMap.QueryVpnAddr(vpnAddr)
-		if hostInfo == nil {
-			return w.WriteLine(fmt.Sprintf("Could not find tunnel for vpn addr: %v", a[0]))
-		}
-
-		cert = hostInfo.GetCert().Certificate
-	}
-
-	if args.Json || args.Pretty {
-		b, err := cert.MarshalJSON()
-		if err != nil {
-			return nil
-		}
-
-		if args.Pretty {
-			buf := new(bytes.Buffer)
-			err := json.Indent(buf, b, "", "    ")
-			b = buf.Bytes()
-			if err != nil {
-				return nil
-			}
-		}
-
-		return w.WriteBytes(b)
-	}
-
-	if args.Raw {
-		b, err := cert.MarshalPEM()
-		if err != nil {
-			return nil
-		}
-
-		return w.WriteBytes(b)
-	}
-
-	return w.WriteLine(cert.String())
-}
-
-func cmdPrintRelays(ifce *Interface, fs any, a []string, w diag.StringWriter) error {
-	args, ok := fs.(*printTunnelFlags)
-	if !ok {
-		return fmt.Errorf("internal error: expected flags to be printTunnelFlags but was %+v", fs)
-	}
-
-	relays := map[uint32]*HostInfo{}
-	ifce.hostMap.Lock()
-	maps.Copy(relays, ifce.hostMap.Relays)
-	ifce.hostMap.Unlock()
-
-	type RelayFor struct {
-		Error          error
-		Type           string
-		State          string
-		PeerAddr       netip.Addr
-		LocalIndex     uint32
-		RemoteIndex    uint32
-		RelayedThrough []netip.Addr
-	}
-
-	type RelayOutput struct {
-		NebulaAddr    netip.Addr
-		RelayForAddrs []RelayFor
-	}
-
-	type CmdOutput struct {
-		Relays []*RelayOutput
-	}
-
-	co := CmdOutput{}
-
-	enc := json.NewEncoder(w.GetWriter())
-
-	if args.Pretty {
-		enc.SetIndent("", "    ")
-	}
-
-	for k, v := range relays {
-		ro := RelayOutput{NebulaAddr: v.vpnAddrs[0]}
-		co.Relays = append(co.Relays, &ro)
-		relayHI := ifce.hostMap.QueryVpnAddr(v.vpnAddrs[0])
-		if relayHI == nil {
-			ro.RelayForAddrs = append(ro.RelayForAddrs, RelayFor{Error: errors.New("could not find hostinfo")})
-			continue
-		}
-		for _, vpnAddr := range relayHI.relayState.CopyRelayForIps() {
-			rf := RelayFor{Error: nil}
-			r, ok := relayHI.relayState.GetRelayForByAddr(vpnAddr)
-			if ok {
-				t := ""
-				switch r.Type {
-				case ForwardingType:
-					t = "forwarding"
-				case TerminalType:
-					t = "terminal"
-				default:
-					t = "unknown"
-				}
-
-				s := ""
-				switch r.State {
-				case Requested:
-					s = "requested"
-				case Established:
-					s = "established"
-				default:
-					s = "unknown"
-				}
-
-				rf.LocalIndex = r.LocalIndex
-				rf.RemoteIndex = r.RemoteIndex
-				rf.PeerAddr = r.PeerAddr
-				rf.Type = t
-				rf.State = s
-				if rf.LocalIndex != k {
-					rf.Error = fmt.Errorf("hostmap LocalIndex '%v' does not match RelayState LocalIndex", k)
-				}
-			}
-			relayedHI := ifce.hostMap.QueryVpnAddr(vpnAddr)
-			if relayedHI != nil {
-				rf.RelayedThrough = append(rf.RelayedThrough, relayedHI.relayState.CopyRelayIps()...)
-			}
-
-			ro.RelayForAddrs = append(ro.RelayForAddrs, rf)
-		}
-	}
-	err := enc.Encode(co)
-	if err != nil {
-		return err
-	}
-	return nil
-}
-
-func cmdPrintTunnel(ifce *Interface, fs any, a []string, w diag.StringWriter) error {
-	args, ok := fs.(*printTunnelFlags)
-	if !ok {
-		return fmt.Errorf("internal error: expected flags to be printTunnelFlags but was %+v", fs)
-	}
-
-	if len(a) == 0 {
-		return w.WriteLine("No vpn address was provided")
-	}
-
-	vpnAddr, err := netip.ParseAddr(a[0])
-	if err != nil {
-		return w.WriteLine(fmt.Sprintf("The provided vpn addr could not be parsed: %s", a[0]))
-	}
-
-	if !vpnAddr.IsValid() {
-		return w.WriteLine(fmt.Sprintf("The provided vpn addr could not be parsed: %s", a[0]))
-	}
-
-	hostInfo := ifce.hostMap.QueryVpnAddr(vpnAddr)
-	if hostInfo == nil {
-		return w.WriteLine(fmt.Sprintf("Could not find tunnel for vpn addr: %v", a[0]))
-	}
-
-	enc := json.NewEncoder(w.GetWriter())
-	if args.Pretty {
-		enc.SetIndent("", "    ")
-	}
-
-	return enc.Encode(copyHostInfo(hostInfo, ifce.hostMap.GetPreferredRanges()))
-}
-
-func cmdDeviceInfo(ifce *Interface, fs any, w diag.StringWriter) error {
-
-	data := struct {
-		Name string         `json:"name"`
-		Cidr []netip.Prefix `json:"cidr"`
-	}{
-		Name: ifce.inside.Name(),
-		Cidr: make([]netip.Prefix, len(ifce.inside.Networks())),
-	}
-
-	copy(data.Cidr, ifce.inside.Networks())
-
-	flags, ok := fs.(*deviceInfoFlags)
-	if !ok {
-		return fmt.Errorf("internal error: expected flags to be deviceInfoFlags but was %+v", fs)
-	}
-
-	if flags.Json || flags.Pretty {
-		js := json.NewEncoder(w.GetWriter())
-		if flags.Pretty {
-			js.SetIndent("", "    ")
-		}
-
-		return js.Encode(data)
-	} else {
-		return w.WriteLine(fmt.Sprintf("name=%v cidr=%v", data.Name, data.Cidr))
-	}
-}
-
-func cmdReload(c *config.C, w diag.StringWriter) error {
-	err := w.WriteLine("Reloading config")
-	c.ReloadConfig()
-	return err
-}

commands_test.go

@@ -1,69 +0,0 @@
-package nebula
-
-import (
-	"bytes"
-	"log/slog"
-	"testing"
-
-	"github.com/slackhq/nebula/config"
-	"github.com/slackhq/nebula/diag"
-	"github.com/stretchr/testify/assert"
-	"github.com/stretchr/testify/require"
-)
-
-// attachedCommands is every command nebula exposes. The ssh console and `nebula ctl` dispatch
-// against this one set, so this list is the contract for both transports.
-var attachedCommands = []string{
-	"change-remote",
-	"close-tunnel",
-	"create-tunnel",
-	"device-info",
-	"list-hostmap",
-	"list-lighthouse-addrmap",
-	"list-pending-hostmap",
-	"log-format",
-	"log-level",
-	"mutex-profile-fraction",
-	"print-cert",
-	"print-relays",
-	"print-tunnel",
-	"query-lighthouse",
-	"reload",
-	"save-heap-profile",
-	"save-mutex-profile",
-	"start-cpu-profile",
-	"stop-cpu-profile",
-	"version",
-}
-
-func TestAttachCommands(t *testing.T) {
-	l := slog.New(slog.DiscardHandler)
-	reg := diag.NewRegistry()
-
-	// The callbacks capture these but do not touch them until a command runs, and this test
-	// only registers and asks for help.
-	attachCommands(l, config.NewC(l), reg, &Interface{})
-
-	t.Run("every command is registered", func(t *testing.T) {
-		for _, name := range attachedCommands {
-			assert.Equal(t, []string{name}, reg.Match(name), "%s is not registered", name)
-		}
-	})
-
-	t.Run("help is available for every command", func(t *testing.T) {
-		for _, name := range attachedCommands {
-			buf := &bytes.Buffer{}
-			require.NoError(t, reg.DispatchArgs([]string{"help", name}, diag.NewWriter(buf)), name)
-			assert.Contains(t, buf.String(), name+" - ", name)
-		}
-	})
-
-	t.Run("the command list names them all", func(t *testing.T) {
-		buf := &bytes.Buffer{}
-		require.NoError(t, reg.DispatchArgs(nil, diag.NewWriter(buf)))
-
-		for _, name := range attachedCommands {
-			assert.Contains(t, buf.String(), name+" - ", name)
-		}
-	})
-}

config/config.go

@@ -5,6 +5,7 @@ import (
 	"errors"
 	"fmt"
 	"log/slog"
+	"maps"
 	"math"
 	"os"
 	"os/signal"
@@ -154,9 +155,7 @@ func (c *C) ReloadConfig() {
 	defer c.reloadLock.Unlock()
 
 	c.oldSettings = make(map[string]any)
-	for k, v := range c.Settings {
-		c.oldSettings[k] = v
-	}
+	maps.Copy(c.oldSettings, c.Settings)
 
 	err := c.Load(c.path)
 	if err != nil {
@@ -177,9 +176,7 @@ func (c *C) ReloadConfigString(raw string) error {
 	defer c.reloadLock.Unlock()
 
 	c.oldSettings = make(map[string]any)
-	for k, v := range c.Settings {
-		c.oldSettings[k] = v
-	}
+	maps.Copy(c.oldSettings, c.Settings)
 
 	err := c.LoadString(raw)
 	if err != nil {
@@ -216,7 +213,7 @@ func (c *C) GetStringSlice(k string, d []string) []string {
 	}
 
 	v := make([]string, len(rv))
-	for i := 0; i < len(v); i++ {
+	for i := range v {
 		v[i] = fmt.Sprintf("%v", rv[i])
 	}
 
@@ -310,8 +307,8 @@ func (c *C) IsSet(k string) bool {
 }
 
 func (c *C) get(k string, v any) any {
-	parts := strings.Split(k, ".")
-	for _, p := range parts {
+	parts := strings.SplitSeq(k, ".")
+	for p := range parts {
 		m, ok := v.(map[string]any)
 		if !ok {
 			return nil

connection_state_test.go

@@ -97,7 +97,7 @@ func TestConnectionState_NextMessageCounter(t *testing.T) {
 	assert.Equal(t, RejectAfterMessages, cs.messageCounter.Load())
 
 	// Continued send attempts stay refused and the counter never wraps
-	for i := 0; i < 10; i++ {
+	for range 10 {
 		_, ok = cs.NextMessageCounter()
 		assert.False(t, ok)
 	}

control.go

@@ -50,7 +50,6 @@ type Control struct {
 	ctx                    context.Context
 	cancel                 context.CancelFunc
 	sshStart               func()
-	ctlStart               func()
 	statsStart             func()
 	dnsStart               func()
 	lighthouseStart        func()
@@ -100,9 +99,6 @@ func (c *Control) Start() error {
 	if c.sshStart != nil {
 		go c.sshStart()
 	}
-	if c.ctlStart != nil {
-		go c.ctlStart()
-	}
 	if c.statsStart != nil {
 		go c.statsStart()
 	}

control_lifecycle_test.go

@@ -247,7 +247,7 @@ func TestControl_ConcurrentStopAndStart(t *testing.T) {
 	c, _, _ := newReadyControl(t)
 
 	var wg sync.WaitGroup
-	for i := 0; i < 2; i++ {
+	for range 2 {
 		wg.Go(func() { c.Stop() })
 	}
 	wg.Go(func() { _ = c.Start() })

ctl.go

@@ -1,234 +0,0 @@
-package nebula
-
-import (
-	"context"
-	"errors"
-	"log/slog"
-	"net"
-	"path/filepath"
-	"sync"
-
-	"github.com/slackhq/nebula/config"
-	"github.com/slackhq/nebula/diag"
-	"github.com/slackhq/nebula/util"
-)
-
-// ctlConfig is the parsed form of the `ctl` config block. It is comparable so that a reload
-// can tell "nothing changed" from "the socket moved" with ==.
-type ctlConfig struct {
-	enabled bool
-	socket  string
-
-	// explicit records that the operator named a socket path rather than taking the platform
-	// default. It only affects how loudly a failure to listen is reported: an unprivileged
-	// nebula that cannot create /run/nebula is a normal deployment, not a problem to shout
-	// about on every upgrade, but a path someone chose deliberately failing to bind is.
-	explicit bool
-}
-
-// ctlServer owns the unix socket `nebula ctl` connects to. It exposes the same command
-// registry the ssh console does, minus the ceremony of running an ssh server: the socket is
-// local only and guarded by filesystem permissions, so it needs no keys.
-//
-// The lifecycle mirrors statsServer: the constructor wires the reload callback, reload
-// records config and reconciles a running listener, Start builds and serves the runtime, and
-// Stop tears it down.
-type ctlServer struct {
-	l   *slog.Logger
-	ctx context.Context
-	srv *diag.Server
-
-	runMu  sync.Mutex
-	runCfg *ctlConfig
-	run    *ctlRuntime
-}
-
-// ctlRuntime is the live state owned by a single Start invocation.
-type ctlRuntime struct {
-	cancel   context.CancelFunc
-	listener net.Listener
-}
-
-// newCtlServerFromConfig builds a ctlServer, parses the config, and registers a reload
-// callback. It deliberately does not start listening: there is no interface yet, and
-// Control.Start is what launches the first runtime. The callback is registered before the
-// config is parsed so a SIGHUP can fix a bad block even if the first parse failed.
-//
-// reg is only held, never read, until Start runs. That is what lets this be constructed
-// before attachCommands has populated the registry.
-func newCtlServerFromConfig(ctx context.Context, l *slog.Logger, c *config.C, reg *diag.Registry) (*ctlServer, error) {
-	s := &ctlServer{
-		l:   l,
-		ctx: ctx,
-		srv: diag.NewServer(l, reg),
-	}
-
-	c.RegisterReloadCallback(func(c *config.C) {
-		if err := s.reload(c, false); err != nil {
-			s.l.Error("Failed to reload ctl from config", "error", err)
-		}
-	})
-
-	if err := s.reload(c, true); err != nil {
-		return s, err
-	}
-
-	return s, nil
-}
-
-// loadCtlConfig parses and validates the `ctl` block. An empty socket path while enabled is
-// not an error: it means the platform has no default and the operator did not name one, so
-// there is simply nothing to listen on.
-func loadCtlConfig(c *config.C) (ctlConfig, error) {
-	cfg := ctlConfig{
-		enabled:  c.GetBool("ctl.enabled", true),
-		socket:   c.GetString("ctl.socket", diag.DefaultSocketPath()),
-		explicit: c.IsSet("ctl.socket"),
-	}
-
-	if cfg.enabled && cfg.socket != "" && !filepath.IsAbs(cfg.socket) {
-		return cfg, util.NewContextualError("ctl.socket must be an absolute path", m{"path": cfg.socket}, nil)
-	}
-
-	return cfg, nil
-}
-
-// reload parses the config and records it, then reconciles the running listener against it:
-//
-//   - newly enabled -> spawn Start
-//   - newly disabled -> Stop the runtime
-//   - socket moved (still enabled) -> Stop the old, Start the new
-//   - no change -> no-op
-//
-// On the initial call it only records configuration; Control.Start is what launches the first
-// runtime via ctlStart. There is no interface to serve yet at that point.
-func (s *ctlServer) reload(c *config.C, initial bool) error {
-	newCfg, err := loadCtlConfig(c)
-	if err != nil {
-		return err
-	}
-
-	s.runMu.Lock()
-	sameCfg := s.runCfg != nil && *s.runCfg == newCfg
-	s.runCfg = &newCfg
-	running := s.run != nil
-	s.runMu.Unlock()
-
-	if initial || sameCfg {
-		return nil
-	}
-
-	if running {
-		s.Stop()
-	}
-
-	if newCfg.enabled && newCfg.socket != "" {
-		go s.Start()
-	}
-
-	return nil
-}
-
-// Start binds the socket and serves until Stop is called or ctx fires. Safe to call when ctl
-// is disabled or already running: both no-op.
-func (s *ctlServer) Start() {
-	s.runMu.Lock()
-	if s.ctx.Err() != nil || s.run != nil || s.runCfg == nil {
-		s.runMu.Unlock()
-		return
-	}
-	cfg := *s.runCfg
-	s.runMu.Unlock()
-
-	if !cfg.enabled || cfg.socket == "" {
-		if cfg.enabled {
-			s.l.Info("ctl has no socket path on this platform, `nebula ctl` will not be available",
-				"hint", "set ctl.socket to enable it",
-			)
-		}
-		return
-	}
-
-	listener, err := diag.Listen(cfg.socket)
-	if err != nil {
-		// A default path nebula cannot create is an ordinary state for an unprivileged
-		// install; a path the operator chose failing to bind is something they want to know
-		// about. Either way ctl is optional and nebula carries on without it.
-		if cfg.explicit {
-			s.l.Error("Failed to listen on the ctl socket", "ctlSocket", cfg.socket, "error", err)
-		} else {
-			s.l.Info("Not serving the ctl socket, `nebula ctl` will not be available",
-				"ctlSocket", cfg.socket,
-				"error", err,
-				"hint", "set ctl.socket to a path nebula can write, or ctl.enabled to false",
-			)
-		}
-
-		// Drop the cached config so a SIGHUP retries once the underlying problem is fixed,
-		// even when the config itself is unchanged.
-		s.runMu.Lock()
-		if s.runCfg != nil && *s.runCfg == cfg {
-			s.runCfg = nil
-		}
-		s.runMu.Unlock()
-		return
-	}
-
-	runCtx, cancel := context.WithCancel(s.ctx)
-	rt := &ctlRuntime{cancel: cancel, listener: listener}
-
-	s.runMu.Lock()
-	// Losing the race against a Stop or a competing Start means this listener is already
-	// obsolete. Close it rather than serving a socket nobody will tear down.
-	if s.ctx.Err() != nil || s.run != nil {
-		s.runMu.Unlock()
-		cancel()
-		_ = listener.Close()
-		return
-	}
-	s.run = rt
-	s.runMu.Unlock()
-
-	s.l.Info("ctl socket is listening", "ctlSocket", cfg.socket)
-
-	err = s.srv.Serve(runCtx, listener)
-	if err != nil {
-		s.l.Error("The ctl listener stopped", "ctlSocket", cfg.socket, "error", err)
-	}
-
-	// Clear our runtime only if nothing has replaced it.
-	s.runMu.Lock()
-	if s.run == rt {
-		rt.cancel()
-		s.run = nil
-		if err != nil {
-			// An unclean exit leaves runCfg cached as if it were applied, so drop it and let a
-			// SIGHUP retry.
-			s.runCfg = nil
-		}
-	}
-	s.runMu.Unlock()
-}
-
-// Stop closes the listener and unlinks the socket. It deliberately does not touch connections
-// that are already being served: `nebula ctl reload` runs every reload callback inline on its
-// own connection, including this one, and hanging up on it would truncate the response to a
-// reload that actually succeeded.
-//
-// The socket file is removed by net.UnixListener's unlink-on-close, so there is no os.Remove
-// here; doing it by hand would delete a successor's socket after a fast reload.
-func (s *ctlServer) Stop() {
-	s.runMu.Lock()
-	rt := s.run
-	s.run = nil
-	s.runMu.Unlock()
-
-	if rt == nil {
-		return
-	}
-
-	rt.cancel()
-	if err := rt.listener.Close(); err != nil && !errors.Is(err, net.ErrClosed) {
-		s.l.Warn("Failed to close the ctl listener", "error", err)
-	}
-}

ctl_test.go

@@ -1,305 +0,0 @@
-//go:build !windows
-
-package nebula
-
-import (
-	"context"
-	"log/slog"
-	"os"
-	"path/filepath"
-	"testing"
-	"time"
-
-	"github.com/slackhq/nebula/config"
-	"github.com/slackhq/nebula/diag"
-	"github.com/stretchr/testify/assert"
-	"github.com/stretchr/testify/require"
-)
-
-func newTestCtlServer(t *testing.T) (*ctlServer, *config.C) {
-	t.Helper()
-	l := slog.New(slog.DiscardHandler)
-	ctx, cancel := context.WithCancel(context.Background())
-	t.Cleanup(cancel)
-
-	return &ctlServer{
-		l:   l,
-		ctx: ctx,
-		srv: diag.NewServer(l, diag.NewRegistry()),
-	}, config.NewC(l)
-}
-
-func setCtlConfig(c *config.C, m map[string]any) {
-	c.Settings["ctl"] = m
-}
-
-func currentCtlRuntime(s *ctlServer) *ctlRuntime {
-	s.runMu.Lock()
-	defer s.runMu.Unlock()
-	return s.run
-}
-
-// testCtlSocket returns a short socket path, see the note in diag/server_test.go about
-// sun_path on darwin.
-func testCtlSocket(t *testing.T) string {
-	t.Helper()
-
-	dir, err := os.MkdirTemp("/tmp", "nebctl")
-	require.NoError(t, err)
-	t.Cleanup(func() { _ = os.RemoveAll(dir) })
-
-	return filepath.Join(dir, "ctl.sock")
-}
-
-func startCtl(t *testing.T, s *ctlServer) chan struct{} {
-	t.Helper()
-
-	done := make(chan struct{})
-	go func() {
-		s.Start()
-		close(done)
-	}()
-	return done
-}
-
-func requireCtlStopped(t *testing.T, done chan struct{}) {
-	t.Helper()
-
-	select {
-	case <-done:
-	case <-time.After(5 * time.Second):
-		t.Fatal("ctl Start did not return after Stop")
-	}
-}
-
-func TestCtlServer_loadConfig(t *testing.T) {
-	t.Run("defaults to enabled at the platform path", func(t *testing.T) {
-		_, c := newTestCtlServer(t)
-
-		cfg, err := loadCtlConfig(c)
-		require.NoError(t, err)
-		assert.True(t, cfg.enabled)
-		assert.Equal(t, diag.DefaultSocketPath(), cfg.socket)
-		assert.False(t, cfg.explicit)
-	})
-
-	t.Run("an operator chosen path is recorded as explicit", func(t *testing.T) {
-		_, c := newTestCtlServer(t)
-		setCtlConfig(c, map[string]any{"socket": "/run/somewhere/ctl.sock"})
-
-		cfg, err := loadCtlConfig(c)
-		require.NoError(t, err)
-		assert.Equal(t, "/run/somewhere/ctl.sock", cfg.socket)
-		assert.True(t, cfg.explicit)
-	})
-
-	t.Run("a relative path is rejected", func(t *testing.T) {
-		_, c := newTestCtlServer(t)
-		setCtlConfig(c, map[string]any{"socket": "ctl.sock"})
-
-		_, err := loadCtlConfig(c)
-		require.Error(t, err)
-		assert.Contains(t, err.Error(), "must be an absolute path")
-	})
-
-	t.Run("a relative path is not rejected when ctl is off", func(t *testing.T) {
-		_, c := newTestCtlServer(t)
-		setCtlConfig(c, map[string]any{"enabled": false, "socket": "ctl.sock"})
-
-		_, err := loadCtlConfig(c)
-		assert.NoError(t, err)
-	})
-}
-
-func TestCtlServer_reload(t *testing.T) {
-	t.Run("the initial reload records config without listening", func(t *testing.T) {
-		s, c := newTestCtlServer(t)
-		setCtlConfig(c, map[string]any{"socket": testCtlSocket(t)})
-
-		require.NoError(t, s.reload(c, true))
-		assert.Nil(t, currentCtlRuntime(s), "Control.Start is what starts listening")
-	})
-
-	t.Run("enabling on reload starts listening", func(t *testing.T) {
-		s, c := newTestCtlServer(t)
-		path := testCtlSocket(t)
-		setCtlConfig(c, map[string]any{"enabled": false, "socket": path})
-		require.NoError(t, s.reload(c, true))
-
-		setCtlConfig(c, map[string]any{"enabled": true, "socket": path})
-		require.NoError(t, s.reload(c, false))
-
-		waitFor(t, func() bool { return currentCtlRuntime(s) != nil })
-		assert.FileExists(t, path)
-
-		s.Stop()
-	})
-
-	t.Run("disabling on reload stops listening and unlinks", func(t *testing.T) {
-		s, c := newTestCtlServer(t)
-		path := testCtlSocket(t)
-		setCtlConfig(c, map[string]any{"enabled": true, "socket": path})
-		require.NoError(t, s.reload(c, true))
-
-		done := startCtl(t, s)
-		waitFor(t, func() bool { return currentCtlRuntime(s) != nil })
-
-		setCtlConfig(c, map[string]any{"enabled": false, "socket": path})
-		require.NoError(t, s.reload(c, false))
-
-		requireCtlStopped(t, done)
-		assert.Nil(t, currentCtlRuntime(s))
-		assert.NoFileExists(t, path)
-	})
-
-	t.Run("moving the socket restarts at the new path", func(t *testing.T) {
-		s, c := newTestCtlServer(t)
-		oldPath := testCtlSocket(t)
-		newPath := testCtlSocket(t)
-		setCtlConfig(c, map[string]any{"socket": oldPath})
-		require.NoError(t, s.reload(c, true))
-
-		done := startCtl(t, s)
-		waitFor(t, func() bool { return currentCtlRuntime(s) != nil })
-		require.FileExists(t, oldPath)
-
-		setCtlConfig(c, map[string]any{"socket": newPath})
-		require.NoError(t, s.reload(c, false))
-		requireCtlStopped(t, done)
-
-		waitFor(t, func() bool { return currentCtlRuntime(s) != nil })
-		assert.FileExists(t, newPath)
-		assert.NoFileExists(t, oldPath, "the old socket should have been unlinked")
-
-		s.Stop()
-	})
-
-	t.Run("an unchanged config leaves the listener alone", func(t *testing.T) {
-		s, c := newTestCtlServer(t)
-		setCtlConfig(c, map[string]any{"socket": testCtlSocket(t)})
-		require.NoError(t, s.reload(c, true))
-
-		startCtl(t, s)
-		waitFor(t, func() bool { return currentCtlRuntime(s) != nil })
-		before := currentCtlRuntime(s)
-
-		require.NoError(t, s.reload(c, false))
-		assert.Same(t, before, currentCtlRuntime(s), "the runtime should not have been replaced")
-
-		s.Stop()
-	})
-}
-
-func TestCtlServer_Start(t *testing.T) {
-	t.Run("a command can be run over the socket", func(t *testing.T) {
-		l := slog.New(slog.DiscardHandler)
-		ctx, cancel := context.WithCancel(context.Background())
-		t.Cleanup(cancel)
-
-		reg := diag.NewRegistry()
-		s := &ctlServer{l: l, ctx: ctx, srv: diag.NewServer(l, reg)}
-		c := config.NewC(l)
-
-		path := testCtlSocket(t)
-		setCtlConfig(c, map[string]any{"socket": path})
-		require.NoError(t, s.reload(c, true))
-
-		startCtl(t, s)
-		waitFor(t, func() bool { return currentCtlRuntime(s) != nil })
-
-		client, err := diag.Dial(path)
-		require.NoError(t, err)
-		defer client.Close()
-
-		out := &testWriter{}
-		status, err := client.Run([]string{"help"}, out)
-		require.NoError(t, err)
-		assert.Equal(t, diag.StatusOK, status)
-		assert.Contains(t, out.String(), "Available commands:")
-
-		s.Stop()
-	})
-
-	t.Run("Start is a no-op when ctl is disabled", func(t *testing.T) {
-		s, c := newTestCtlServer(t)
-		setCtlConfig(c, map[string]any{"enabled": false, "socket": testCtlSocket(t)})
-		require.NoError(t, s.reload(c, true))
-
-		s.Start()
-		assert.Nil(t, currentCtlRuntime(s))
-	})
-
-	t.Run("Start is a no-op with no socket path for this platform", func(t *testing.T) {
-		s, c := newTestCtlServer(t)
-		setCtlConfig(c, map[string]any{"enabled": true, "socket": ""})
-		require.NoError(t, s.reload(c, true))
-
-		s.Start()
-		assert.Nil(t, currentCtlRuntime(s))
-	})
-
-	t.Run("Start is a no-op after the context is cancelled", func(t *testing.T) {
-		l := slog.New(slog.DiscardHandler)
-		ctx, cancel := context.WithCancel(context.Background())
-		s := &ctlServer{l: l, ctx: ctx, srv: diag.NewServer(l, diag.NewRegistry())}
-		c := config.NewC(l)
-
-		path := testCtlSocket(t)
-		setCtlConfig(c, map[string]any{"socket": path})
-		require.NoError(t, s.reload(c, true))
-		cancel()
-
-		s.Start()
-		assert.Nil(t, currentCtlRuntime(s))
-		assert.NoFileExists(t, path)
-	})
-
-	// A path nebula cannot bind must not stop it from running, and a SIGHUP with the same
-	// config has to be able to retry once the problem is fixed.
-	t.Run("a listen failure is survivable and retried on the next reload", func(t *testing.T) {
-		s, c := newTestCtlServer(t)
-		path := testCtlSocket(t)
-		require.NoError(t, os.MkdirAll(filepath.Dir(path), 0700))
-		require.NoError(t, os.WriteFile(path, []byte("in the way"), 0600))
-
-		setCtlConfig(c, map[string]any{"socket": path})
-		require.NoError(t, s.reload(c, true))
-
-		s.Start()
-		assert.Nil(t, currentCtlRuntime(s))
-
-		s.runMu.Lock()
-		cachedCfg := s.runCfg
-		s.runMu.Unlock()
-		assert.Nil(t, cachedCfg, "the cached config should be dropped so a reload retries")
-
-		require.NoError(t, os.Remove(path))
-		require.NoError(t, s.reload(c, false))
-		waitFor(t, func() bool { return currentCtlRuntime(s) != nil })
-
-		s.Stop()
-	})
-
-	t.Run("Stop is idempotent", func(t *testing.T) {
-		s, c := newTestCtlServer(t)
-		setCtlConfig(c, map[string]any{"socket": testCtlSocket(t)})
-		require.NoError(t, s.reload(c, true))
-
-		done := startCtl(t, s)
-		waitFor(t, func() bool { return currentCtlRuntime(s) != nil })
-
-		s.Stop()
-		requireCtlStopped(t, done)
-		assert.NotPanics(t, s.Stop)
-	})
-}
-
-// testWriter collects command output.
-type testWriter struct{ b []byte }
-
-func (w *testWriter) Write(p []byte) (int, error) {
-	w.b = append(w.b, p...)
-	return len(p), nil
-}
-
-func (w *testWriter) String() string { return string(w.b) }

diag/client.go

@@ -1,41 +0,0 @@
-package diag
-
-import (
-	"bufio"
-	"io"
-	"net"
-	"time"
-)
-
-// dialTimeout bounds the connect only. A command may take as long as it likes to answer.
-const dialTimeout = 2 * time.Second
-
-// Client is a connection to a nebula serving the ctl socket. It carries exactly one command.
-type Client struct {
-	conn net.Conn
-}
-
-// Dial connects to the nebula serving at path. On a platform without socket support the
-// returned error wraps ErrNotSupported.
-func Dial(path string) (*Client, error) {
-	conn, err := dialSocket(path, dialTimeout)
-	if err != nil {
-		return nil, err
-	}
-
-	return &Client{conn: conn}, nil
-}
-
-// Run sends args and streams the command's output to out, returning the command's exit
-// status. A non-nil error means the exchange itself failed and the status means nothing.
-func (c *Client) Run(args []string, out io.Writer) (int, error) {
-	if err := writeRequest(c.conn, args); err != nil {
-		return 0, err
-	}
-
-	return readResponse(bufio.NewReader(c.conn), out)
-}
-
-func (c *Client) Close() error {
-	return c.conn.Close()
-}

diag/proto.go

@@ -1,226 +0,0 @@
-package diag
-
-import (
-	"bufio"
-	"encoding/binary"
-	"encoding/json"
-	"errors"
-	"fmt"
-	"io"
-)
-
-// The ctl protocol is one request, one response, one connection.
-//
-// The request is a single JSON line. argv travels as a list rather than a joined string so
-// that a path with a space in it survives the trip; the client already has a real argv from
-// the operating system and re-splitting it would only ever lose information.
-//
-// The response is a stream of frames rather than raw bytes followed by a status line,
-// because there is no sentinel that is safe to look for: `print-cert -raw` emits arbitrary
-// PEM and `list-hostmap -json` emits arbitrary JSON, either of which could contain whatever
-// terminator we picked.
-const (
-	// ProtoVersion is the only request version this build understands. An unknown version
-	// gets a legible error rather than a hang, which is the whole point of sending it.
-	ProtoVersion = 1
-
-	// frameOutput carries raw command output, destined for the client's stdout.
-	frameOutput = 0x01
-	// frameEnd carries a JSON endPayload and is the last frame on a connection.
-	frameEnd = 0x02
-	// frameStderr is reserved. Commands write to a single writer today, so there is nothing
-	// to put in it, but holding the number means adding one later needs no version bump.
-	frameStderr = 0x03
-
-	// maxFrame bounds a single frame's payload. Larger writes are split across frames.
-	maxFrame = 64 * 1024
-	// maxRequest bounds the request line, so a client that never sends a newline cannot make
-	// nebula buffer without limit.
-	maxRequest = 64 * 1024
-	// outputBuffer is what keeps json.NewEncoder(w.GetWriter()) from emitting a frame per
-	// token; output accumulates here and flushes in useful sized chunks.
-	outputBuffer = 32 * 1024
-)
-
-// ErrTruncated means the connection ended before the end frame arrived, which is how a
-// client notices that nebula died or was torn down partway through a command.
-var ErrTruncated = errors.New("connection closed before the command finished")
-
-// request is the JSON line a client sends.
-type request struct {
-	Version int      `json:"version"`
-	Args    []string `json:"args"`
-}
-
-// endPayload is the JSON body of the end frame. Error is set only when Status is non-zero
-// and describes a failure to run the command, not a failure the command itself reported.
-type endPayload struct {
-	Status int    `json:"status"`
-	Error  string `json:"error,omitempty"`
-}
-
-// writeRequest sends the request line.
-func writeRequest(w io.Writer, args []string) error {
-	b, err := json.Marshal(request{Version: ProtoVersion, Args: args})
-	if err != nil {
-		return err
-	}
-
-	if len(b)+1 > maxRequest {
-		return fmt.Errorf("command line is too long: %d bytes", len(b))
-	}
-
-	_, err = w.Write(append(b, '\n'))
-	return err
-}
-
-// readRequest reads and validates one request line.
-func readRequest(r *bufio.Reader) (request, error) {
-	var req request
-
-	line, err := readLimitedLine(r, maxRequest)
-	if err != nil {
-		return req, err
-	}
-
-	if err := json.Unmarshal(line, &req); err != nil {
-		return req, fmt.Errorf("malformed request: %w", err)
-	}
-
-	if req.Version != ProtoVersion {
-		return req, fmt.Errorf("unsupported protocol version %d, this nebula speaks version %d", req.Version, ProtoVersion)
-	}
-
-	return req, nil
-}
-
-// readLimitedLine reads through the next newline, refusing a line longer than limit rather
-// than buffering whatever an unfriendly client decides to send.
-func readLimitedLine(r *bufio.Reader, limit int) ([]byte, error) {
-	line := make([]byte, 0, 256)
-	for {
-		b, err := r.ReadByte()
-		if err != nil {
-			return nil, err
-		}
-
-		if b == '\n' {
-			return line, nil
-		}
-
-		if len(line) >= limit {
-			return nil, fmt.Errorf("request exceeded %d bytes without a newline", limit)
-		}
-
-		line = append(line, b)
-	}
-}
-
-// frameWriter turns writes into output frames. It is handed to commands wrapped in a
-// bufio.Writer, so a command that makes many small writes does not make many small frames.
-type frameWriter struct {
-	w io.Writer
-}
-
-func (f *frameWriter) Write(b []byte) (int, error) {
-	written := 0
-	for {
-		chunk := b[written:]
-		if len(chunk) > maxFrame {
-			chunk = chunk[:maxFrame]
-		}
-
-		if err := writeFrame(f.w, frameOutput, chunk); err != nil {
-			return written, err
-		}
-
-		written += len(chunk)
-		if written == len(b) {
-			return written, nil
-		}
-	}
-}
-
-// writeFrame emits one frame: a type byte, a big endian length, then the payload.
-func writeFrame(w io.Writer, kind byte, payload []byte) error {
-	var hdr [5]byte
-	hdr[0] = kind
-	binary.BigEndian.PutUint32(hdr[1:], uint32(len(payload)))
-
-	if _, err := w.Write(hdr[:]); err != nil {
-		return err
-	}
-
-	if len(payload) == 0 {
-		return nil
-	}
-
-	_, err := w.Write(payload)
-	return err
-}
-
-// writeEnd emits the final frame. A transport error here is unreportable by definition, the
-// connection is the only channel we have.
-func writeEnd(w io.Writer, status int, msg string) error {
-	b, err := json.Marshal(endPayload{Status: status, Error: msg})
-	if err != nil {
-		return err
-	}
-
-	return writeFrame(w, frameEnd, b)
-}
-
-// readResponse consumes frames until the end frame, copying output to out. It returns the
-// command's exit status. A non-nil error means the exchange failed and the status is
-// meaningless.
-func readResponse(r io.Reader, out io.Writer) (int, error) {
-	var hdr [5]byte
-
-	for {
-		if _, err := io.ReadFull(r, hdr[:]); err != nil {
-			if errors.Is(err, io.EOF) || errors.Is(err, io.ErrUnexpectedEOF) {
-				return 0, ErrTruncated
-			}
-			return 0, err
-		}
-
-		length := binary.BigEndian.Uint32(hdr[1:])
-		if length > maxFrame {
-			return 0, fmt.Errorf("frame of %d bytes exceeds the %d byte maximum", length, maxFrame)
-		}
-
-		payload := make([]byte, length)
-		if _, err := io.ReadFull(r, payload); err != nil {
-			if errors.Is(err, io.EOF) || errors.Is(err, io.ErrUnexpectedEOF) {
-				return 0, ErrTruncated
-			}
-			return 0, err
-		}
-
-		switch hdr[0] {
-		case frameOutput:
-			if _, err := out.Write(payload); err != nil {
-				return 0, err
-			}
-
-		case frameEnd:
-			var end endPayload
-			if err := json.Unmarshal(payload, &end); err != nil {
-				return 0, fmt.Errorf("malformed end frame: %w", err)
-			}
-
-			if end.Error != "" {
-				return end.Status, errors.New(end.Error)
-			}
-
-			return end.Status, nil
-
-		case frameStderr:
-			// Reserved and unused by this build. Skipping rather than failing means an older
-			// client stays usable against a newer nebula that starts sending them.
-
-		default:
-			return 0, fmt.Errorf("unknown frame type 0x%02x", hdr[0])
-		}
-	}
-}

diag/proto_test.go

@@ -1,144 +0,0 @@
-package diag
-
-import (
-	"bufio"
-	"bytes"
-	"encoding/binary"
-	"strings"
-	"testing"
-
-	"github.com/stretchr/testify/assert"
-	"github.com/stretchr/testify/require"
-)
-
-func TestRequestRoundTrip(t *testing.T) {
-	t.Run("argv survives a round trip, spaces and all", func(t *testing.T) {
-		buf := &bytes.Buffer{}
-		args := []string{"start-cpu-profile", "/tmp/a path.pb.gz", "-json"}
-		require.NoError(t, writeRequest(buf, args))
-
-		req, err := readRequest(bufio.NewReader(buf))
-		require.NoError(t, err)
-		assert.Equal(t, ProtoVersion, req.Version)
-		assert.Equal(t, args, req.Args)
-	})
-
-	t.Run("an unknown version is refused by name", func(t *testing.T) {
-		r := bufio.NewReader(strings.NewReader(`{"version":99,"args":["version"]}` + "\n"))
-
-		_, err := readRequest(r)
-		require.Error(t, err)
-		assert.Contains(t, err.Error(), "unsupported protocol version 99")
-	})
-
-	t.Run("malformed json is refused", func(t *testing.T) {
-		r := bufio.NewReader(strings.NewReader("not json\n"))
-
-		_, err := readRequest(r)
-		require.Error(t, err)
-		assert.Contains(t, err.Error(), "malformed request")
-	})
-
-	t.Run("a line without a newline is bounded rather than buffered forever", func(t *testing.T) {
-		r := bufio.NewReader(strings.NewReader(strings.Repeat("a", maxRequest+10)))
-
-		_, err := readRequest(r)
-		require.Error(t, err)
-		assert.Contains(t, err.Error(), "without a newline")
-	})
-}
-
-func TestResponseRoundTrip(t *testing.T) {
-	t.Run("output and status survive a round trip", func(t *testing.T) {
-		wire := &bytes.Buffer{}
-		w := bufio.NewWriterSize(&frameWriter{w: wire}, outputBuffer)
-		require.NoError(t, NewWriter(w).WriteLine("hello"))
-		require.NoError(t, w.Flush())
-		require.NoError(t, writeEnd(wire, StatusOK, ""))
-
-		out := &bytes.Buffer{}
-		status, err := readResponse(wire, out)
-		require.NoError(t, err)
-		assert.Equal(t, StatusOK, status)
-		assert.Equal(t, "hello\n", out.String())
-	})
-
-	// print-cert -raw and list-hostmap -json both emit arbitrary bytes, so a payload larger
-	// than one frame has to reassemble exactly.
-	t.Run("a payload larger than one frame reassembles byte for byte", func(t *testing.T) {
-		big := bytes.Repeat([]byte("nebula"), maxFrame)
-
-		wire := &bytes.Buffer{}
-		fw := &frameWriter{w: wire}
-		n, err := fw.Write(big)
-		require.NoError(t, err)
-		require.Equal(t, len(big), n)
-		require.NoError(t, writeEnd(wire, StatusOK, ""))
-
-		out := &bytes.Buffer{}
-		status, err := readResponse(wire, out)
-		require.NoError(t, err)
-		assert.Equal(t, StatusOK, status)
-		assert.Equal(t, big, out.Bytes())
-	})
-
-	t.Run("a non-zero status carries its message", func(t *testing.T) {
-		wire := &bytes.Buffer{}
-		require.NoError(t, writeEnd(wire, StatusError, "it went wrong"))
-
-		status, err := readResponse(wire, &bytes.Buffer{})
-		require.Error(t, err)
-		assert.Equal(t, StatusError, status)
-		assert.Contains(t, err.Error(), "it went wrong")
-	})
-
-	// This is how the CLI notices a nebula that died mid-command rather than silently
-	// reporting whatever partial output it managed to read.
-	t.Run("a stream ending without an end frame is truncated, not successful", func(t *testing.T) {
-		wire := &bytes.Buffer{}
-		_, err := (&frameWriter{w: wire}).Write([]byte("partial"))
-		require.NoError(t, err)
-
-		out := &bytes.Buffer{}
-		_, err = readResponse(wire, out)
-		assert.ErrorIs(t, err, ErrTruncated)
-	})
-
-	t.Run("a truncated frame header is truncated, not successful", func(t *testing.T) {
-		_, err := readResponse(bytes.NewReader([]byte{frameOutput, 0x00}), &bytes.Buffer{})
-		assert.ErrorIs(t, err, ErrTruncated)
-	})
-
-	t.Run("an oversized frame is refused rather than allocated", func(t *testing.T) {
-		var hdr [5]byte
-		hdr[0] = frameOutput
-		binary.BigEndian.PutUint32(hdr[1:], maxFrame+1)
-
-		_, err := readResponse(bytes.NewReader(hdr[:]), &bytes.Buffer{})
-		require.Error(t, err)
-		assert.Contains(t, err.Error(), "exceeds")
-	})
-
-	// A reserved frame an older client does not understand must not break it.
-	t.Run("a reserved frame type is skipped", func(t *testing.T) {
-		wire := &bytes.Buffer{}
-		require.NoError(t, writeFrame(wire, frameStderr, []byte("future")))
-		require.NoError(t, writeFrame(wire, frameOutput, []byte("now")))
-		require.NoError(t, writeEnd(wire, StatusOK, ""))
-
-		out := &bytes.Buffer{}
-		status, err := readResponse(wire, out)
-		require.NoError(t, err)
-		assert.Equal(t, StatusOK, status)
-		assert.Equal(t, "now", out.String())
-	})
-
-	t.Run("an unknown frame type is an error", func(t *testing.T) {
-		wire := &bytes.Buffer{}
-		require.NoError(t, writeFrame(wire, 0x7f, nil))
-
-		_, err := readResponse(wire, &bytes.Buffer{})
-		require.Error(t, err)
-		assert.Contains(t, err.Error(), "unknown frame type")
-	})
-}

diag/registry.go

@@ -1,125 +0,0 @@
-package diag
-
-import (
-	"fmt"
-	"sync"
-
-	"github.com/anmitsu/go-shlex"
-	"github.com/armon/go-radix"
-)
-
-// Registry is the set of commands nebula exposes for debugging and administration. It is
-// transport neutral: the ssh console and the `nebula ctl` unix socket dispatch against the
-// same registry, and neither knows the other exists.
-//
-// Registration is expected to happen once during startup, before any transport is serving,
-// but the lock makes a late RegisterCommand safe rather than a data race waiting to happen.
-type Registry struct {
-	mu       sync.RWMutex
-	commands *radix.Tree
-}
-
-// NewRegistry returns a registry containing only `help`. Everything else is attached by
-// the caller, see attachCommands in the nebula package.
-func NewRegistry() *Registry {
-	r := &Registry{commands: radix.New()}
-
-	r.RegisterCommand(&Command{
-		Name:             "help",
-		ShortDescription: "prints available commands or help <command> for specific usage info",
-		Callback: func(a any, args []string, w StringWriter) error {
-			return r.help(args, w)
-		},
-	})
-
-	return r
-}
-
-// RegisterCommand adds a command that a user can run.
-func (r *Registry) RegisterCommand(c *Command) {
-	r.mu.Lock()
-	defer r.mu.Unlock()
-	r.commands.Insert(c.Name, c)
-}
-
-// Clone returns an independent copy sharing no tree with the original. The ssh session uses
-// this so the `logout` command it adds for itself is invisible to every other session, and
-// to `nebula ctl`.
-func (r *Registry) Clone() *Registry {
-	r.mu.RLock()
-	defer r.mu.RUnlock()
-	return &Registry{commands: radix.NewFromMap(r.commands.ToMap())}
-}
-
-// Match returns every registered command name carrying the given prefix, for tab completion.
-func (r *Registry) Match(prefix string) []string {
-	r.mu.RLock()
-	defer r.mu.RUnlock()
-	return matchCommand(r.commands, prefix)
-}
-
-// Dispatch splits line the way a shell would and runs the result. The ssh console uses this
-// because a terminal only ever hands it a line; a transport that already has a real argv
-// should call DispatchArgs instead rather than round tripping through a quoting parser.
-func (r *Registry) Dispatch(line string, w StringWriter) error {
-	args, err := shlex.Split(line, true)
-	if err != nil {
-		if wErr := w.WriteLine(fmt.Sprintf("Unable to parse command: %s", err)); wErr != nil {
-			return wErr
-		}
-		return err
-	}
-
-	return r.DispatchArgs(args, w)
-}
-
-// DispatchArgs runs args[0] with args[1:] as its arguments, writing everything the command
-// produces to w. An empty args dumps the command list, matching what an empty line does on
-// the ssh console.
-//
-// Callbacks report user facing problems as prose on w and return nil by convention, so a
-// non-nil error here means the command could not be run at all: ErrUnknownCommand, an
-// ErrUsage wrapped flag failure, or an internal failure a callback chose to surface.
-func (r *Registry) DispatchArgs(args []string, w StringWriter) error {
-	if len(args) == 0 {
-		r.mu.RLock()
-		defer r.mu.RUnlock()
-		dumpCommands(r.commands, w)
-		return nil
-	}
-
-	r.mu.RLock()
-	cmd, err := lookupCommand(r.commands, args[0])
-	r.mu.RUnlock()
-	if err != nil {
-		if wErr := w.WriteLine(fmt.Sprintf("Command lookup failed: %s", err)); wErr != nil {
-			return wErr
-		}
-		return err
-	}
-
-	if cmd == nil {
-		if wErr := w.WriteLine(fmt.Sprintf("Did not understand: %s", args[0])); wErr != nil {
-			return wErr
-		}
-		r.mu.RLock()
-		defer r.mu.RUnlock()
-		dumpCommands(r.commands, w)
-		return fmt.Errorf("%w: %s", ErrUnknownCommand, args[0])
-	}
-
-	// -h and -help anywhere in the arguments mean the user wants to know how the command
-	// works, not to run it.
-	if checkHelpArgs(args) {
-		return r.help([]string{cmd.Name}, w)
-	}
-
-	return execCommand(cmd, args[1:], w)
-}
-
-// help renders the command list, or one command's usage, onto w.
-func (r *Registry) help(args []string, w StringWriter) error {
-	r.mu.RLock()
-	defer r.mu.RUnlock()
-	return helpCallback(r.commands, args, w)
-}

diag/registry_test.go

@@ -1,167 +0,0 @@
-package diag
-
-import (
-	"bytes"
-	"flag"
-	"strings"
-	"testing"
-
-	"github.com/stretchr/testify/assert"
-	"github.com/stretchr/testify/require"
-)
-
-type testFlags struct {
-	Json bool
-}
-
-// testCommand builds a command carrying a flag set, recording what the callback was actually
-// handed so a test can assert on it.
-func testCommand(name string, seen *any, args *[]string) *Command {
-	return &Command{
-		Name:             name,
-		ShortDescription: name + " short description",
-		Flags: func() (*flag.FlagSet, any) {
-			fl := flag.NewFlagSet("", flag.ContinueOnError)
-			f := &testFlags{}
-			fl.BoolVar(&f.Json, "json", false, "outputs json")
-			return fl, f
-		},
-		Callback: func(fs any, a []string, w StringWriter) error {
-			if seen != nil {
-				*seen = fs
-			}
-			if args != nil {
-				*args = a
-			}
-			return w.WriteLine("ran " + name)
-		},
-	}
-}
-
-func newTestRegistry(t *testing.T) (*Registry, *bytes.Buffer, StringWriter) {
-	t.Helper()
-	buf := &bytes.Buffer{}
-	return NewRegistry(), buf, NewWriter(buf)
-}
-
-func TestRegistryDispatch(t *testing.T) {
-	t.Run("a new registry knows help and nothing else", func(t *testing.T) {
-		r, buf, w := newTestRegistry(t)
-
-		require.NoError(t, r.DispatchArgs([]string{"help"}, w))
-		assert.Contains(t, buf.String(), "help -")
-	})
-
-	t.Run("empty args dump the command list, matching an empty line on the console", func(t *testing.T) {
-		r, buf, w := newTestRegistry(t)
-		r.RegisterCommand(testCommand("do-thing", nil, nil))
-
-		require.NoError(t, r.DispatchArgs(nil, w))
-		assert.Contains(t, buf.String(), "Available commands:")
-		assert.Contains(t, buf.String(), "do-thing - do-thing short description")
-	})
-
-	t.Run("an unknown command reports ErrUnknownCommand and still tells the user", func(t *testing.T) {
-		r, buf, w := newTestRegistry(t)
-
-		err := r.DispatchArgs([]string{"nope"}, w)
-		require.ErrorIs(t, err, ErrUnknownCommand)
-		assert.Contains(t, buf.String(), "Did not understand: nope")
-		assert.Contains(t, buf.String(), "Available commands:")
-	})
-
-	// This is the hazard the ctl transport has to preserve: every callback in ssh.go begins by
-	// type asserting fs to its own concrete flags struct. Reach a callback without going
-	// through Command.Flags and every one of them fails.
-	t.Run("a callback is handed the concrete struct its Flags callback returned", func(t *testing.T) {
-		var seen any
-		r, _, w := newTestRegistry(t)
-		r.RegisterCommand(testCommand("do-thing", &seen, nil))
-
-		require.NoError(t, r.DispatchArgs([]string{"do-thing", "-json"}, w))
-
-		flags, ok := seen.(*testFlags)
-		require.True(t, ok, "callback was handed %T, not *testFlags", seen)
-		assert.True(t, flags.Json)
-	})
-
-	t.Run("positional arguments survive flag parsing", func(t *testing.T) {
-		var args []string
-		r, _, w := newTestRegistry(t)
-		r.RegisterCommand(testCommand("do-thing", nil, &args))
-
-		require.NoError(t, r.DispatchArgs([]string{"do-thing", "-json", "10.0.0.1"}, w))
-		assert.Equal(t, []string{"10.0.0.1"}, args)
-	})
-
-	// Documents stdlib flag behaviour rather than endorsing it: parsing stops at the first
-	// positional, so a flag written after one is silently a positional too.
-	t.Run("a flag after a positional is not parsed as a flag", func(t *testing.T) {
-		var seen any
-		var args []string
-		r, _, w := newTestRegistry(t)
-		r.RegisterCommand(testCommand("do-thing", &seen, &args))
-
-		require.NoError(t, r.DispatchArgs([]string{"do-thing", "10.0.0.1", "-json"}, w))
-		assert.False(t, seen.(*testFlags).Json)
-		assert.Equal(t, []string{"10.0.0.1", "-json"}, args)
-	})
-
-	t.Run("a bad flag reports ErrUsage and writes the usage text", func(t *testing.T) {
-		r, buf, w := newTestRegistry(t)
-		r.RegisterCommand(testCommand("do-thing", nil, nil))
-
-		err := r.DispatchArgs([]string{"do-thing", "-nope"}, w)
-		require.ErrorIs(t, err, ErrUsage)
-		assert.Contains(t, buf.String(), "flag provided but not defined")
-	})
-
-	t.Run("-h anywhere routes to help instead of running the command", func(t *testing.T) {
-		var seen any
-		r, buf, w := newTestRegistry(t)
-		r.RegisterCommand(testCommand("do-thing", &seen, nil))
-
-		require.NoError(t, r.DispatchArgs([]string{"do-thing", "-h"}, w))
-		assert.Nil(t, seen, "the callback should not have run")
-		assert.Contains(t, buf.String(), "do-thing - do-thing short description")
-		assert.Contains(t, buf.String(), "-json")
-	})
-
-	t.Run("Dispatch splits a line the way a shell would", func(t *testing.T) {
-		var args []string
-		r, _, w := newTestRegistry(t)
-		r.RegisterCommand(testCommand("do-thing", nil, &args))
-
-		require.NoError(t, r.Dispatch(`do-thing "/tmp/a path.pb.gz"`, w))
-		assert.Equal(t, []string{"/tmp/a path.pb.gz"}, args)
-	})
-
-	t.Run("Match returns names by prefix for tab completion", func(t *testing.T) {
-		r, _, _ := newTestRegistry(t)
-		r.RegisterCommand(testCommand("print-cert", nil, nil))
-		r.RegisterCommand(testCommand("print-tunnel", nil, nil))
-		r.RegisterCommand(testCommand("version", nil, nil))
-
-		assert.Equal(t, []string{"print-cert", "print-tunnel"}, r.Match("print-"))
-	})
-}
-
-// A clone is what keeps the ssh session's `logout` command from being visible to every other
-// session, and to nebula ctl.
-func TestRegistryCloneIsolation(t *testing.T) {
-	parent, _, w := newTestRegistry(t)
-	parent.RegisterCommand(testCommand("shared", nil, nil))
-
-	child := parent.Clone()
-	child.RegisterCommand(testCommand("logout", nil, nil))
-
-	require.NoError(t, child.DispatchArgs([]string{"logout"}, w))
-
-	buf := &bytes.Buffer{}
-	err := parent.DispatchArgs([]string{"logout"}, NewWriter(buf))
-	assert.ErrorIs(t, err, ErrUnknownCommand)
-
-	buf.Reset()
-	require.NoError(t, child.DispatchArgs([]string{"shared"}, NewWriter(buf)))
-	assert.True(t, strings.HasPrefix(buf.String(), "ran shared"))
-}

diag/server.go

@@ -1,137 +0,0 @@
-package diag
-
-import (
-	"bufio"
-	"context"
-	"errors"
-	"fmt"
-	"log/slog"
-	"net"
-	"time"
-)
-
-// Exit statuses the client reports. They follow shell convention closely enough that a
-// script can tell "you asked for something that does not exist" from "it ran and failed".
-const (
-	// StatusOK means the command ran. Note that commands report their own user facing
-	// problems as prose and still exit 0, matching the ssh console.
-	StatusOK = 0
-	// StatusError means the command could not be completed.
-	StatusError = 1
-	// StatusUsage means the arguments were not valid for that command.
-	StatusUsage = 2
-	// StatusUnknownCommand means there is no such command.
-	StatusUnknownCommand = 127
-)
-
-// requestTimeout bounds how long a connected client may take to send its request line. There
-// is deliberately no timeout on the response: `reload` runs every reload callback inline
-// before it returns, and a slow one is not a reason to hang up on the operator.
-const requestTimeout = 5 * time.Second
-
-// Server serves a Registry over a stream listener. It knows nothing about unix sockets, so
-// tests can drive it over a net.Pipe.
-type Server struct {
-	l   *slog.Logger
-	reg *Registry
-}
-
-func NewServer(l *slog.Logger, reg *Registry) *Server {
-	return &Server{l: l, reg: reg}
-}
-
-// Serve accepts connections until ln is closed. Cancelling ctx closes ln, which is what ends
-// the accept loop; a listener closed underneath us is a normal shutdown, not an error.
-func (s *Server) Serve(ctx context.Context, ln net.Listener) error {
-	go func() {
-		<-ctx.Done()
-		if err := ln.Close(); err != nil && !errors.Is(err, net.ErrClosed) {
-			s.l.Warn("Failed to close the ctl listener", "error", err)
-		}
-	}()
-
-	for {
-		conn, err := ln.Accept()
-		if err != nil {
-			if errors.Is(err, net.ErrClosed) || ctx.Err() != nil {
-				return nil
-			}
-			return err
-		}
-
-		go s.ServeConn(ctx, conn)
-	}
-}
-
-// ServeConn handles one request and closes c.
-func (s *Server) ServeConn(ctx context.Context, c net.Conn) {
-	defer func() {
-		if err := c.Close(); err != nil && !errors.Is(err, net.ErrClosed) {
-			s.l.Debug("Failed to close a ctl connection", "error", err)
-		}
-	}()
-
-	if err := c.SetReadDeadline(time.Now().Add(requestTimeout)); err != nil {
-		s.l.Debug("Failed to set a ctl read deadline", "error", err)
-	}
-
-	req, err := readRequest(bufio.NewReaderSize(c, maxRequest))
-	if err != nil {
-		s.l.Debug("Rejected a ctl request", "error", err)
-		// Best effort: the client may already be gone, and there is nowhere else to report it.
-		_ = writeEnd(c, StatusError, err.Error())
-		return
-	}
-
-	// The request is in hand, so the command owns the rest of the connection's lifetime.
-	if err := c.SetReadDeadline(time.Time{}); err != nil {
-		s.l.Debug("Failed to clear the ctl read deadline", "error", err)
-	}
-
-	s.l.Debug("Running a ctl command", "args", req.Args)
-
-	buf := bufio.NewWriterSize(&frameWriter{w: c}, outputBuffer)
-	dispatchErr := s.reg.DispatchArgs(req.Args, NewWriter(buf))
-
-	if err := buf.Flush(); err != nil {
-		s.l.Debug("Failed to flush ctl output", "error", err)
-		return
-	}
-
-	status, msg := statusFor(dispatchErr)
-	if err := writeEnd(c, status, msg); err != nil {
-		s.l.Debug("Failed to write the ctl end frame", "error", err)
-	}
-}
-
-// StatusFor maps a dispatch error onto an exit status, for a transport that has somewhere to
-// put one.
-func StatusFor(err error) int {
-	status, _ := statusFor(err)
-	return status
-}
-
-// statusFor maps a dispatch error onto an exit status and, when the failure is ours to
-// explain rather than one the command already wrote as prose, a message to go with it.
-func statusFor(err error) (int, string) {
-	switch {
-	case err == nil:
-		return StatusOK, ""
-	case errors.Is(err, ErrUnknownCommand):
-		return StatusUnknownCommand, ""
-	case errors.Is(err, ErrUsage):
-		return StatusUsage, ""
-	default:
-		return StatusError, fmt.Sprintf("%s", err)
-	}
-}
-
-// ErrNotSupported means this platform has no ctl transport. Windows is waiting on a named
-// pipe implementation; mobile has no daemon for a CLI to attach to in the first place.
-var ErrNotSupported = errors.New("nebula ctl is not supported on this platform")
-
-// Listen creates the ctl listener at path. It is the platform boundary: everything above it
-// in this package is portable.
-func Listen(path string) (net.Listener, error) {
-	return listenSocket(path)
-}

diag/server_test.go

@@ -1,273 +0,0 @@
-//go:build !windows
-
-package diag
-
-import (
-	"bytes"
-	"context"
-	"errors"
-	"fmt"
-	"io/fs"
-	"log/slog"
-	"net"
-	"os"
-	"path/filepath"
-	"sync"
-	"testing"
-	"time"
-
-	"github.com/stretchr/testify/assert"
-	"github.com/stretchr/testify/require"
-)
-
-// testSocketPath returns a short socket path. t.TempDir on darwin lives under
-// /var/folders/... and readily exceeds the 104 byte sun_path limit, which fails as a bare
-// "invalid argument" a long way from the cause.
-func testSocketPath(t *testing.T) string {
-	t.Helper()
-
-	dir, err := os.MkdirTemp("/tmp", "nebctl")
-	require.NoError(t, err)
-	t.Cleanup(func() { _ = os.RemoveAll(dir) })
-
-	path := filepath.Join(dir, "sub", "ctl.sock")
-	require.LessOrEqual(t, len(path), maxSocketPath, "test socket path is too long for sun_path")
-	return path
-}
-
-func newTestServer(t *testing.T) (*Registry, string) {
-	t.Helper()
-
-	reg := NewRegistry()
-	path := testSocketPath(t)
-
-	ln, err := Listen(path)
-	require.NoError(t, err)
-
-	ctx, cancel := context.WithCancel(context.Background())
-	srv := NewServer(slog.New(slog.DiscardHandler), reg)
-
-	var wg sync.WaitGroup
-	wg.Add(1)
-	go func() {
-		defer wg.Done()
-		assert.NoError(t, srv.Serve(ctx, ln))
-	}()
-
-	t.Cleanup(func() {
-		cancel()
-		wg.Wait()
-	})
-
-	return reg, path
-}
-
-func run(t *testing.T, path string, args ...string) (string, int, error) {
-	t.Helper()
-
-	c, err := Dial(path)
-	require.NoError(t, err)
-	defer c.Close()
-
-	out := &bytes.Buffer{}
-	status, err := c.Run(args, out)
-	return out.String(), status, err
-}
-
-func TestServeConn(t *testing.T) {
-	t.Run("a command runs and its output comes back", func(t *testing.T) {
-		reg, path := newTestServer(t)
-		reg.RegisterCommand(&Command{
-			Name:             "version",
-			ShortDescription: "prints a version",
-			Callback: func(fs any, a []string, w StringWriter) error {
-				return w.WriteLine("1.2.3")
-			},
-		})
-
-		out, status, err := run(t, path, "version")
-		require.NoError(t, err)
-		assert.Equal(t, StatusOK, status)
-		assert.Equal(t, "1.2.3\n", out)
-	})
-
-	t.Run("no args gets the command list", func(t *testing.T) {
-		_, path := newTestServer(t)
-
-		out, status, err := run(t, path)
-		require.NoError(t, err)
-		assert.Equal(t, StatusOK, status)
-		assert.Contains(t, out, "Available commands:")
-	})
-
-	t.Run("an unknown command exits 127", func(t *testing.T) {
-		_, path := newTestServer(t)
-
-		out, status, err := run(t, path, "nope")
-		require.NoError(t, err)
-		assert.Equal(t, StatusUnknownCommand, status)
-		assert.Contains(t, out, "Did not understand: nope")
-	})
-
-	t.Run("a bad flag exits 2", func(t *testing.T) {
-		reg, path := newTestServer(t)
-		var seen any
-		reg.RegisterCommand(testCommand("do-thing", &seen, nil))
-
-		out, status, err := run(t, path, "do-thing", "-nope")
-		require.NoError(t, err)
-		assert.Equal(t, StatusUsage, status)
-		assert.Contains(t, out, "flag provided but not defined")
-	})
-
-	t.Run("a callback error exits 1 and reports why", func(t *testing.T) {
-		reg, path := newTestServer(t)
-		reg.RegisterCommand(&Command{
-			Name:             "explode",
-			ShortDescription: "fails",
-			Callback: func(fs any, a []string, w StringWriter) error {
-				return errors.New("boom")
-			},
-		})
-
-		_, status, err := run(t, path, "explode")
-		require.Error(t, err)
-		assert.Equal(t, StatusError, status)
-		assert.Contains(t, err.Error(), "boom")
-	})
-
-	t.Run("output larger than the buffer arrives intact", func(t *testing.T) {
-		reg, path := newTestServer(t)
-		want := bytes.Repeat([]byte("x"), outputBuffer*3+7)
-		reg.RegisterCommand(&Command{
-			Name:             "big",
-			ShortDescription: "writes a lot",
-			Callback: func(fs any, a []string, w StringWriter) error {
-				return w.WriteBytes(want)
-			},
-		})
-
-		out, status, err := run(t, path, "big")
-		require.NoError(t, err)
-		assert.Equal(t, StatusOK, status)
-		assert.Equal(t, string(want), out)
-	})
-
-	t.Run("concurrent clients are all served", func(t *testing.T) {
-		reg, path := newTestServer(t)
-		reg.RegisterCommand(&Command{
-			Name:             "slow",
-			ShortDescription: "takes a moment",
-			Callback: func(fs any, a []string, w StringWriter) error {
-				time.Sleep(10 * time.Millisecond)
-				return w.WriteLine("done")
-			},
-		})
-
-		var wg sync.WaitGroup
-		for i := 0; i < 8; i++ {
-			wg.Add(1)
-			go func() {
-				defer wg.Done()
-				out, status, err := run(t, path, "slow")
-				assert.NoError(t, err)
-				assert.Equal(t, StatusOK, status)
-				assert.Equal(t, "done\n", out)
-			}()
-		}
-		wg.Wait()
-	})
-
-	t.Run("a client that hangs up mid command does not take the server down", func(t *testing.T) {
-		reg, path := newTestServer(t)
-		reg.RegisterCommand(&Command{
-			Name:             "version",
-			ShortDescription: "prints a version",
-			Callback: func(fs any, a []string, w StringWriter) error {
-				return w.WriteLine("1.2.3")
-			},
-		})
-
-		c, err := Dial(path)
-		require.NoError(t, err)
-		require.NoError(t, writeRequest(c.conn, []string{"version"}))
-		require.NoError(t, c.Close())
-
-		// The next client still gets served.
-		out, status, err := run(t, path, "version")
-		require.NoError(t, err)
-		assert.Equal(t, StatusOK, status)
-		assert.Equal(t, "1.2.3\n", out)
-	})
-}
-
-func TestListenSocket(t *testing.T) {
-	t.Run("the socket is 0600 inside a 0700 directory", func(t *testing.T) {
-		path := testSocketPath(t)
-		ln, err := Listen(path)
-		require.NoError(t, err)
-		defer ln.Close()
-
-		fi, err := os.Stat(path)
-		require.NoError(t, err)
-		assert.Equal(t, os.FileMode(0600), fi.Mode().Perm(), "socket mode")
-
-		di, err := os.Stat(filepath.Dir(path))
-		require.NoError(t, err)
-		assert.Equal(t, os.FileMode(0700), di.Mode().Perm(), "socket directory mode")
-	})
-
-	t.Run("the socket is unlinked when the listener closes", func(t *testing.T) {
-		path := testSocketPath(t)
-		ln, err := Listen(path)
-		require.NoError(t, err)
-		require.NoError(t, ln.Close())
-
-		_, err = os.Stat(path)
-		assert.ErrorIs(t, err, fs.ErrNotExist)
-	})
-
-	// A crashed nebula leaves its socket behind, and the next one has to be able to start.
-	t.Run("a socket left behind by a dead nebula is replaced", func(t *testing.T) {
-		path := testSocketPath(t)
-		ln, err := Listen(path)
-		require.NoError(t, err)
-
-		// Close the listener without unlinking, the way a killed process leaves things.
-		unix, ok := ln.(*net.UnixListener)
-		require.True(t, ok)
-		unix.SetUnlinkOnClose(false)
-		require.NoError(t, ln.Close())
-		require.FileExists(t, path)
-
-		ln2, err := Listen(path)
-		require.NoError(t, err)
-		assert.NoError(t, ln2.Close())
-	})
-
-	// Silently stealing it would break the nebula that got there first.
-	t.Run("a socket another nebula is serving is refused", func(t *testing.T) {
-		_, path := newTestServer(t)
-
-		_, err := Listen(path)
-		require.Error(t, err)
-		assert.Contains(t, err.Error(), "already being served")
-	})
-
-	t.Run("a path that is not a socket is refused rather than removed", func(t *testing.T) {
-		path := testSocketPath(t)
-		require.NoError(t, os.MkdirAll(filepath.Dir(path), 0700))
-		require.NoError(t, os.WriteFile(path, []byte("precious"), 0600))
-
-		_, err := Listen(path)
-		require.Error(t, err)
-		assert.Contains(t, err.Error(), "is not a socket")
-		assert.FileExists(t, path, "the file must not have been removed")
-	})
-
-	t.Run("a path too long for sun_path says so", func(t *testing.T) {
-		_, err := Listen("/tmp/" + fmt.Sprintf("%0*d", maxSocketPath, 0) + "/ctl.sock")
-		require.Error(t, err)
-		assert.Contains(t, err.Error(), "the maximum is")
-	})
-}

diag/socket_unix.go

@@ -1,107 +0,0 @@
-//go:build !windows
-
-package diag
-
-import (
-	"errors"
-	"fmt"
-	"io/fs"
-	"net"
-	"os"
-	"path/filepath"
-	"runtime"
-	"time"
-)
-
-// maxSocketPath is the smallest sun_path across the platforms nebula ships on: 104 bytes on
-// darwin and the BSDs, 108 on Linux. Checking it ourselves turns a bare "invalid argument"
-// into something an operator can act on.
-const maxSocketPath = 103
-
-// DefaultSocketPath is where nebula listens when ctl.socket is unset. An empty string means
-// the platform has no sensible default and ctl stays off unless an operator names a path.
-func DefaultSocketPath() string {
-	switch runtime.GOOS {
-	case "ios", "android":
-		// No daemon to attach to and no shell to attach from, and nowhere writable that
-		// would survive being guessed. Mobile embedders drive nebula through Control.
-		return ""
-	case "linux":
-		return "/run/nebula/ctl.sock"
-	default:
-		// /run does not exist on darwin, and /var/run is the portable spelling everywhere
-		// else nebula builds.
-		return "/var/run/nebula/ctl.sock"
-	}
-}
-
-// listenSocket creates the listening socket at path, taking over one a previous nebula left
-// behind but refusing one that is still being served.
-func listenSocket(path string) (net.Listener, error) {
-	if len(path) > maxSocketPath {
-		return nil, fmt.Errorf("socket path is %d bytes, the maximum is %d", len(path), maxSocketPath)
-	}
-
-	// The directory, not the socket, is what enforces access control. net.Listen creates the
-	// socket with 0777&^umask, so with a typical 0022 umask it is world connectable for the
-	// window between bind and chmod. Nobody can traverse into a 0700 directory to reach it in
-	// that window, and unlike the socket's own mode, directory traversal is enforced
-	// consistently across every platform this file builds for.
-	dir := filepath.Dir(path)
-	if err := os.MkdirAll(dir, 0700); err != nil {
-		return nil, fmt.Errorf("failed to create %s: %w", dir, err)
-	}
-	if err := os.Chmod(dir, 0700); err != nil {
-		return nil, fmt.Errorf("failed to set permissions on %s: %w", dir, err)
-	}
-
-	if err := clearStaleSocket(path); err != nil {
-		return nil, err
-	}
-
-	ln, err := net.Listen("unix", path)
-	if err != nil {
-		return nil, err
-	}
-
-	// Defence in depth behind the directory, for anyone who relocates the socket somewhere
-	// more permissive.
-	if err := os.Chmod(path, 0600); err != nil {
-		_ = ln.Close()
-		return nil, fmt.Errorf("failed to set permissions on %s: %w", path, err)
-	}
-
-	return ln, nil
-}
-
-// dialSocket connects to a nebula serving at path.
-func dialSocket(path string, timeout time.Duration) (net.Conn, error) {
-	return net.DialTimeout("unix", path, timeout)
-}
-
-// clearStaleSocket removes a socket a crashed nebula left behind, but refuses to steal one
-// another nebula is still serving. Two instances on one host need two paths; they cannot
-// share one, and silently taking the socket would break the instance that got there first.
-func clearStaleSocket(path string) error {
-	fi, err := os.Lstat(path)
-	if errors.Is(err, fs.ErrNotExist) {
-		return nil
-	}
-	if err != nil {
-		return err
-	}
-
-	if fi.Mode()&fs.ModeSocket == 0 {
-		return fmt.Errorf("%s exists and is not a socket, refusing to remove it", path)
-	}
-
-	// A successful dial is the only reliable way to tell a live socket from an abandoned
-	// one; the inode looks identical either way.
-	c, err := net.DialTimeout("unix", path, 100*time.Millisecond)
-	if err == nil {
-		_ = c.Close()
-		return fmt.Errorf("%s is already being served, is another nebula running?", path)
-	}
-
-	return os.Remove(path)
-}

diag/socket_windows.go

@@ -1,27 +0,0 @@
-//go:build windows
-
-package diag
-
-import (
-	"net"
-	"time"
-)
-
-// Windows has AF_UNIX since Windows 10 1803, but no way to secure the socket that resembles
-// what the unix build does: os.Chmod cannot express an ACL, and a socket's reachability comes
-// down to whatever its directory inherited. Doing this properly means a named pipe with an
-// explicit security descriptor, which is a dependency and a design this change does not carry.
-// Until then the stub keeps the package building and gives operators a real answer.
-
-// DefaultSocketPath returns an empty string: there is no path worth defaulting to here.
-func DefaultSocketPath() string {
-	return ""
-}
-
-func listenSocket(path string) (net.Listener, error) {
-	return nil, ErrNotSupported
-}
-
-func dialSocket(path string, timeout time.Duration) (net.Conn, error) {
-	return nil, ErrNotSupported
-}

e2e/echo_test.go

@@ -1,5 +1,4 @@
 //go:build e2e_testing
-// +build e2e_testing
 
 package e2e
 

e2e/handshake_manager_test.go

@@ -1,5 +1,4 @@
 //go:build e2e_testing
-// +build e2e_testing
 
 package e2e
 

e2e/handshakes_test.go

@@ -1,5 +1,4 @@
 //go:build e2e_testing
-// +build e2e_testing
 
 package e2e
 

e2e/helpers_test.go

@@ -1,5 +1,4 @@
 //go:build e2e_testing
-// +build e2e_testing
 
 package e2e
 
@@ -116,9 +115,6 @@ func newSimpleServerWithUdpAndUnsafeNetworks(v cert.Version, caCrt cert.Certific
 			"key":  string(myPrivKey),
 		},
 		//"tun": m{"disabled": true},
-		// Several tests bring up more than one nebula in this process, and they would all
-		// contend for the same default ctl socket path. None of them exercise it.
-		"ctl": m{"enabled": false},
 		"firewall": m{
 			"outbound": []m{{
 				"proto": "any",
@@ -216,9 +212,6 @@ func newServer(caCrt []cert.Certificate, certs []cert.Certificate, key []byte, o
 			"key":  string(key),
 		},
 		//"tun": m{"disabled": true},
-		// Several tests bring up more than one nebula in this process, and they would all
-		// contend for the same default ctl socket path. None of them exercise it.
-		"ctl": m{"enabled": false},
 		"firewall": m{
 			"outbound": []m{{
 				"proto": "any",

e2e/leak_test.go

@@ -1,5 +1,4 @@
 //go:build e2e_testing
-// +build e2e_testing
 
 package e2e
 

e2e/rebind_test.go

@@ -1,5 +1,4 @@
 //go:build e2e_testing
-// +build e2e_testing
 
 package e2e
 

e2e/recovery_timing_test.go

@@ -1,5 +1,4 @@
 //go:build e2e_testing
-// +build e2e_testing
 
 package e2e
 

e2e/router/hostmap.go

@@ -1,5 +1,4 @@
 //go:build e2e_testing
-// +build e2e_testing
 
 package router
 

e2e/router/router.go

@@ -1,5 +1,4 @@
 //go:build e2e_testing
-// +build e2e_testing
 
 package router
 

e2e/sshd_test.go

@@ -1,5 +1,4 @@
 //go:build e2e_testing
-// +build e2e_testing
 
 package e2e
 

e2e/tunnels_test.go

@@ -1,5 +1,4 @@
 //go:build e2e_testing
-// +build e2e_testing
 
 package e2e
 

examples/config.yml

@@ -236,30 +236,6 @@ punchy:
   # Overriding this to "" is the same as "/" and will allow overwriting any path on the host.
   #sandbox_dir: /var/tmp/nebula-debug
 
-# ctl exposes nebula's debug and administrative commands over a local unix socket, so that `nebula ctl <command>` can
-# reach the same commands the sshd block offers above without running an ssh server. Run `nebula ctl` on its own for the
-# list of commands. Anyone who can open the socket can do everything the ssh console can, including closing tunnels,
-# changing remotes, and writing profile data to disk, so the socket lives in a directory only the user nebula runs as
-# can enter. Enabled by default. Not supported on Windows yet, and never enabled on iOS or Android.
-#ctl:
-  # Toggles the feature. This setting is reloadable.
-  #enabled: true
-
-  # socket is the unix socket to listen on. The parent directory is created if it is missing and made readable only by
-  # the user nebula runs as, and a socket left behind by a crashed nebula is replaced. Defaults to /run/nebula/ctl.sock
-  # on Linux and /var/run/nebula/ctl.sock everywhere else; running nebula as a non-root user means picking a path it can
-  # write. Two nebulas on one host need two paths, the second to start will log that the socket is already being served
-  # and carry on without one. `nebula ctl` reads this value from the same config file when it is given -config, and
-  # otherwise assumes the default above. This setting is reloadable.
-  #socket: /run/nebula/ctl.sock
-
-  # sandbox_dir restricts the file paths the profiling commands (start-cpu-profile, save-heap-profile,
-  # save-mutex-profile) may write, exactly like sshd.sandbox_dir above, which it defaults to. Note that these paths are
-  # resolved by the nebula process and not by the shell running `nebula ctl`, so a relative path lands in this directory
-  # rather than in your working directory, and under a systemd unit with PrivateTmp=yes it lands somewhere your shell
-  # cannot see at all. The directory is NOT automatically created.
-  #sandbox_dir: /var/tmp/nebula-debug
-
 # EXPERIMENTAL: relay support for networks that can't establish direct connections.
 relay:
   # Relays are a list of Nebula IP's that peers can use to relay packets to me.

firewall/cache_test.go

@@ -22,7 +22,7 @@ func newFixedTicker(t *testing.T, l *slog.Logger, cacheLen int) *ConntrackCacheT
 		l:     l,
 		cache: make(ConntrackCache, cacheLen),
 	}
-	for i := 0; i < cacheLen; i++ {
+	for i := range cacheLen {
 		c.cache[Packet{LocalPort: uint16(i) + 1}] = struct{}{}
 	}
 	c.cacheTick.Store(1) // cacheV starts at 0, so Get() takes the reset path

lighthouse.go

@@ -34,9 +34,7 @@ type LightHouse struct {
 
 	myVpnNetworks      []netip.Prefix
 	myVpnNetworksTable *bart.Lite
-	// myVpnAddrsTable contains our overlay host addrs, as opposed to the overlay networks
-	myVpnAddrsTable *bart.Lite
-	punchy          *Punchy
+	punchy             *Punchy
 
 	// localAddrsFn enumerates the underlay addresses we advertise. It is a field so tests can supply simulated
 	// addresses rather than whatever this machine's NICs happen to be. Set it before Start.
@@ -106,7 +104,6 @@ func NewLightHouseFromConfig(ctx context.Context, l *slog.Logger, c *config.C, c
 		amLighthouse:       amLighthouse,
 		myVpnNetworks:      cs.myVpnNetworks,
 		myVpnNetworksTable: cs.myVpnNetworksTable,
-		myVpnAddrsTable:    cs.myVpnAddrsTable,
 		addrMap:            make(map[netip.Addr]*RemoteList),
 		nebulaPort:         nebulaPort,
 		punchy:             p,
@@ -1161,17 +1158,6 @@ func (lhh *LightHouseHandler) handleHostQuery(n *NebulaMeta, fromVpnAddrs []neti
 		return
 	}
 
-	// Don't respond to requests for us.
-	if lhh.lh.myVpnAddrsTable.Contains(queryVpnAddr) {
-		if lhh.l.Enabled(context.Background(), slog.LevelDebug) {
-			lhh.l.Debug("Ignoring HostQuery for one of my own addresses",
-				"fromVpnAddrs", fromVpnAddrs,
-				"queryVpnAddr", queryVpnAddr,
-			)
-		}
-		return
-	}
-
 	found, ln, err := lhh.lh.queryAndPrepMessage(queryVpnAddr, func(c *cache) (int, error) {
 		n = lhh.resetMeta()
 		n.Type = NebulaMeta_HostQueryReply

lighthouse_test.go

@@ -27,27 +27,15 @@ func TestOldIPv4Only(t *testing.T) {
 	assert.Equal(t, binary.BigEndian.Uint32(bp[:]), m.GetAddr())
 }
 
-func testCertState(networks ...netip.Prefix) *CertState {
-	cs := &CertState{
-		myVpnNetworks:      networks,
-		myVpnNetworksTable: new(bart.Lite),
-		myVpnAddrs:         make([]netip.Addr, 0, len(networks)),
-		myVpnAddrsTable:    new(bart.Lite),
-	}
-
-	for _, n := range networks {
-		cs.myVpnNetworksTable.Insert(n)
-		cs.myVpnAddrs = append(cs.myVpnAddrs, n.Addr())
-		cs.myVpnAddrsTable.Insert(netip.PrefixFrom(n.Addr(), n.Addr().BitLen()))
-	}
-
-	return cs
-}
-
 func Test_lhStaticMapping(t *testing.T) {
 	l := test.NewLogger()
 	myVpnNet := netip.MustParsePrefix("10.128.0.1/16")
-	cs := testCertState(myVpnNet)
+	nt := new(bart.Lite)
+	nt.Insert(myVpnNet)
+	cs := &CertState{
+		myVpnNetworks:      []netip.Prefix{myVpnNet},
+		myVpnNetworksTable: nt,
+	}
 	lh1 := "10.128.0.2"
 
 	c := config.NewC(l)
@@ -67,7 +55,12 @@ func Test_lhStaticMapping(t *testing.T) {
 func TestReloadLighthouseInterval(t *testing.T) {
 	l := test.NewLogger()
 	myVpnNet := netip.MustParsePrefix("10.128.0.1/16")
-	cs := testCertState(myVpnNet)
+	nt := new(bart.Lite)
+	nt.Insert(myVpnNet)
+	cs := &CertState{
+		myVpnNetworks:      []netip.Prefix{myVpnNet},
+		myVpnNetworksTable: nt,
+	}
 	lh1 := "10.128.0.2"
 
 	c := config.NewC(l)
@@ -97,7 +90,12 @@ func TestReloadLighthouseInterval(t *testing.T) {
 func BenchmarkLighthouseHandleRequest(b *testing.B) {
 	l := test.NewLogger()
 	myVpnNet := netip.MustParsePrefix("10.128.0.1/0")
-	cs := testCertState(myVpnNet)
+	nt := new(bart.Lite)
+	nt.Insert(myVpnNet)
+	cs := &CertState{
+		myVpnNetworks:      []netip.Prefix{myVpnNet},
+		myVpnNetworksTable: nt,
+	}
 
 	c := config.NewC(l)
 	lh, err := NewLightHouseFromConfig(b.Context(), l, c, cs, nil, nil)
@@ -197,7 +195,12 @@ func TestLighthouse_Memory(t *testing.T) {
 	c.Settings["listen"] = map[string]any{"port": 4242}
 
 	myVpnNet := netip.MustParsePrefix("10.128.0.1/24")
-	cs := testCertState(myVpnNet)
+	nt := new(bart.Lite)
+	nt.Insert(myVpnNet)
+	cs := &CertState{
+		myVpnNetworks:      []netip.Prefix{myVpnNet},
+		myVpnNetworksTable: nt,
+	}
 	lh, err := NewLightHouseFromConfig(t.Context(), l, c, cs, nil, nil)
 	lh.ifce = &mockEncWriter{}
 	require.NoError(t, err)
@@ -277,7 +280,12 @@ func TestLighthouse_reload(t *testing.T) {
 	c.Settings["listen"] = map[string]any{"port": 4242}
 
 	myVpnNet := netip.MustParsePrefix("10.128.0.1/24")
-	cs := testCertState(myVpnNet)
+	nt := new(bart.Lite)
+	nt.Insert(myVpnNet)
+	cs := &CertState{
+		myVpnNetworks:      []netip.Prefix{myVpnNet},
+		myVpnNetworksTable: nt,
+	}
 
 	lh, err := NewLightHouseFromConfig(t.Context(), l, c, cs, nil, nil)
 	require.NoError(t, err)
@@ -307,7 +315,12 @@ func TestLighthouse_reloadStaticHostMap(t *testing.T) {
 	}
 
 	myVpnNet := netip.MustParsePrefix("10.128.0.1/24")
-	cs := testCertState(myVpnNet)
+	nt := new(bart.Lite)
+	nt.Insert(myVpnNet)
+	cs := &CertState{
+		myVpnNetworks:      []netip.Prefix{myVpnNet},
+		myVpnNetworksTable: nt,
+	}
 
 	lh, err := NewLightHouseFromConfig(t.Context(), l, c, cs, nil, nil)
 	require.NoError(t, err)
@@ -416,9 +429,7 @@ func TestLighthouse_reloadStaticHostMap(t *testing.T) {
 	assert.Equal(t, []netip.AddrPort{netip.MustParseAddrPort("3.3.3.3:4242")}, rl.CopyAddrs([]netip.Prefix{}))
 }
 
-// sendLHHostRequest delivers a HostQuery to lhh and hands back the writer that
-// captured what it emitted. Pass a nil filter to see every message.
-func sendLHHostRequest(fromAddr netip.AddrPort, myVpnIp, queryVpnIp netip.Addr, lhh *LightHouseHandler, filter *NebulaMeta_MessageType) *testEncWriter {
+func newLHHostRequest(fromAddr netip.AddrPort, myVpnIp, queryVpnIp netip.Addr, lhh *LightHouseHandler) testLhReply {
 	req := &NebulaMeta{
 		Type:    NebulaMeta_HostQuery,
 		Details: &NebulaMetaDetails{},
@@ -436,59 +447,12 @@ func sendLHHostRequest(fromAddr netip.AddrPort, myVpnIp, queryVpnIp netip.Addr,
 		panic(err)
 	}
 
-	w := &testEncWriter{metaFilter: filter}
-	lhh.HandleRequest(fromAddr, []netip.Addr{myVpnIp}, b, w)
-	return w
-}
-
-func newLHHostRequest(fromAddr netip.AddrPort, myVpnIp, queryVpnIp netip.Addr, lhh *LightHouseHandler) testLhReply {
 	filter := NebulaMeta_HostQueryReply
-	return sendLHHostRequest(fromAddr, myVpnIp, queryVpnIp, lhh, &filter).lastReply
-}
-
-func TestLighthouse_IgnoresHostQueryForItself(t *testing.T) {
-	// Validate that we don't answer host queries for our own address.
-	l := test.NewLogger()
-
-	myVpnNet := netip.MustParsePrefix("10.128.0.1/24")
-	myVpnIp := myVpnNet.Addr()
-
-	c := config.NewC(l)
-	c.Settings["lighthouse"] = map[string]any{"am_lighthouse": true}
-	c.Settings["listen"] = map[string]any{"port": 4242}
-	// Add a static_host_map entry for ourselves, so our address
-	// is in the addrMap.
-	c.Settings["static_host_map"] = map[string]any{
-		myVpnIp.String(): []any{"192.168.100.1:4242"},
+	w := &testEncWriter{
+		metaFilter: &filter,
 	}
-
-	lh, err := NewLightHouseFromConfig(t.Context(), l, c, testCertState(myVpnNet), nil, nil)
-	require.NoError(t, err)
-	lh.ifce = &mockEncWriter{}
-	lhh := lh.NewRequestHandler()
-
-	peerVpnIp := netip.MustParseAddr("10.128.0.2")
-	peerUdpAddr := netip.MustParseAddrPort("10.0.0.2:4242")
-	otherVpnIp := netip.MustParseAddr("10.128.0.3")
-	otherUdpAddr := netip.MustParseAddrPort("10.0.0.3:4242")
-
-	newLHHostUpdate(peerUdpAddr, peerVpnIp, []netip.AddrPort{peerUdpAddr}, lhh)
-	newLHHostUpdate(otherUdpAddr, otherVpnIp, []netip.AddrPort{otherUdpAddr}, lhh)
-
-	// Control: a query about a real peer is still answered, and still ends with
-	// the punch notification aimed at the host that was asked about.
-	w := sendLHHostRequest(peerUdpAddr, peerVpnIp, otherVpnIp, lhh, nil)
-	require.NotNil(t, w.lastReply.msg)
-	assert.Equal(t, NebulaMeta_HostPunchNotification, w.lastReply.msg.Type)
-	assert.Equal(t, otherVpnIp, w.lastReply.vpnIp)
-
-	// Now validate that we don't send to ourselves.
-	found, _, err := lh.queryAndPrepMessage(myVpnIp, func(*cache) (int, error) { return 0, nil })
-	require.NoError(t, err)
-	require.True(t, found, "the lighthouse should hold a cache entry for its own address")
-
-	w = sendLHHostRequest(peerUdpAddr, peerVpnIp, myVpnIp, lhh, nil)
-	assert.Nil(t, w.lastReply.msg, "a query about our own address must produce no reply and no punch notification")
+	lhh.HandleRequest(fromAddr, []netip.Addr{myVpnIp}, b, w)
+	return w.lastReply
 }
 
 func newLHHostUpdate(fromAddr netip.AddrPort, vpnIp netip.Addr, addrs []netip.AddrPort, lhh *LightHouseHandler) {
@@ -678,7 +642,12 @@ func TestLighthouse_Dont_Delete_Static_Hosts(t *testing.T) {
 	}
 
 	myVpnNet := netip.MustParsePrefix("10.128.0.1/24")
-	cs := testCertState(myVpnNet)
+	nt := new(bart.Lite)
+	nt.Insert(myVpnNet)
+	cs := &CertState{
+		myVpnNetworks:      []netip.Prefix{myVpnNet},
+		myVpnNetworksTable: nt,
+	}
 	lh, err := NewLightHouseFromConfig(t.Context(), l, c, cs, nil, nil)
 	require.NoError(t, err)
 	lh.ifce = &mockEncWriter{}
@@ -739,7 +708,12 @@ func TestLighthouse_DeletesWork(t *testing.T) {
 	}
 
 	myVpnNet := netip.MustParsePrefix("10.128.0.1/24")
-	cs := testCertState(myVpnNet)
+	nt := new(bart.Lite)
+	nt.Insert(myVpnNet)
+	cs := &CertState{
+		myVpnNetworks:      []netip.Prefix{myVpnNet},
+		myVpnNetworksTable: nt,
+	}
 	lh, err := NewLightHouseFromConfig(t.Context(), l, c, cs, nil, nil)
 	require.NoError(t, err)
 	lh.ifce = &mockEncWriter{}

main.go

@@ -14,7 +14,6 @@ import (
 
 	"github.com/slackhq/nebula/config"
 	"github.com/slackhq/nebula/cpupick"
-	"github.com/slackhq/nebula/diag"
 	"github.com/slackhq/nebula/noiseutil"
 	"github.com/slackhq/nebula/overlay"
 	"github.com/slackhq/nebula/sshd"
@@ -69,9 +68,7 @@ func Main(c *config.C, configTest bool, buildVersion string, l *slog.Logger, dev
 	}
 	l.Info("Firewall started", "firewallHashes", fw.GetRuleHashes())
 
-	commands := diag.NewRegistry()
-
-	ssh, err := sshd.NewSSHServer(ctx, l.With("subsystem", "sshd"), commands)
+	ssh, err := sshd.NewSSHServer(ctx, l.With("subsystem", "sshd"))
 	if err != nil {
 		return nil, util.ContextualizeIfNeeded("Error while creating SSH server", err)
 	}
@@ -325,20 +322,13 @@ func Main(c *config.C, configTest bool, buildVersion string, l *slog.Logger, dev
 		return nil, util.ContextualizeIfNeeded("Failed to start stats emitter", err)
 	}
 
-	// Built before the configTest return so that a bad ctl block fails `nebula -test`. It only
-	// holds the registry, which attachCommands populates below, and reads nothing until Start.
-	ctlServer, err := newCtlServerFromConfig(ctx, l.With("subsystem", "ctl"), c, commands)
-	if err != nil {
-		return nil, util.ContextualizeIfNeeded("Failed to configure the ctl socket", err)
-	}
-
 	if configTest {
 		return nil, nil
 	}
 
 	go ifce.emitStats(ctx, c.GetDuration("stats.interval", time.Second*10))
 
-	attachCommands(l, c, commands, ifce)
+	attachCommands(l, c, ssh, ifce)
 
 	networkChanges := udp.NewNetworkChangeMonitor(ctx, l, c)
 
@@ -349,7 +339,6 @@ func Main(c *config.C, configTest bool, buildVersion string, l *slog.Logger, dev
 		ctx:                    ctx,
 		cancel:                 cancel,
 		sshStart:               sshStart,
-		ctlStart:               ctlServer.Start,
 		statsStart:             stats.Start,
 		dnsStart:               ds.Start,
 		lighthouseStart:        lightHouse.StartUpdateWorker,

noiseutil/boring.go

@@ -1,5 +1,4 @@
 //go:build boringcrypto
-// +build boringcrypto
 
 package noiseutil
 

noiseutil/boring_test.go

@@ -1,5 +1,4 @@
 //go:build boringcrypto
-// +build boringcrypto
 
 package noiseutil
 

overlay/batch/checksum_seed_test.go

@@ -127,7 +127,7 @@ func TestPseudoSumIPv6MatchesReference(t *testing.T) {
 func TestIPv4HdrChecksumMatchesReference(t *testing.T) {
 	rng := rand.New(rand.NewSource(0x1791))
 	for _, hdrLen := range []int{20, 24, 40, 60} {
-		for trial := 0; trial < 200; trial++ {
+		for trial := range 200 {
 			hdr := make([]byte, hdrLen)
 			rng.Read(hdr)
 			hdr[0] = 0x40 | byte(hdrLen/4)
@@ -156,7 +156,7 @@ func TestIPv4HdrChecksumMatchesReference(t *testing.T) {
 // the way a receiver does (pseudo-header + L4 must sum to all-ones).
 func TestChecksumSeedReceiverAcceptance(t *testing.T) {
 	rng := rand.New(rand.NewSource(0x1826))
-	for trial := 0; trial < 200; trial++ {
+	for trial := range 200 {
 		src := [4]byte{byte(rng.Intn(256)), byte(rng.Intn(256)), byte(rng.Intn(256)), byte(rng.Intn(256))}
 		dst := [4]byte{byte(rng.Intn(256)), byte(rng.Intn(256)), byte(rng.Intn(256)), byte(rng.Intn(256))}
 		payLen := rng.Intn(1500)

overlay/batch/tcp_coalesce_test.go

@@ -540,7 +540,7 @@ func TestCoalescerCapBySegments(t *testing.T) {
 	c := newTestTCPCoalescer(t, w)
 	pay := make([]byte, 512)
 	seq := uint32(1000)
-	for i := 0; i < tcpCoalesceMaxSegs+5; i++ {
+	for range tcpCoalesceMaxSegs + 5 {
 		if err := c.Commit(buildTCPv4(seq, tcpAck, pay)); err != nil {
 			t.Fatal(err)
 		}

overlay/batch/tx_batch_test.go

@@ -28,7 +28,7 @@ func TestSendBatchReserveCommitFlush(t *testing.T) {
 	b := NewSendBatch(fw, 4, 32)
 
 	ap := netip.MustParseAddrPort("10.0.0.1:4242")
-	for i := 0; i < 4; i++ {
+	for i := range 4 {
 		slot := b.Reserve(32)
 		if cap(slot) != 32 {
 			t.Fatalf("slot %d: cap=%d want 32", i, cap(slot))
@@ -72,7 +72,7 @@ func TestSendBatchSlotsDoNotOverlap(t *testing.T) {
 	b := NewSendBatch(fw, 3, 8)
 	ap := netip.MustParseAddrPort("10.0.0.1:80")
 
-	for i := 0; i < 3; i++ {
+	for i := range 3 {
 		s := b.Reserve(8)
 		pkt := append(s[:0], byte(0xA0+i), byte(0xB0+i))
 		b.Commit(pkt, ap)

overlay/batch/udp_coalesce_test.go

@@ -129,7 +129,7 @@ func TestUDPCoalescerCoalescesEqualSized(t *testing.T) {
 	w := &fakeTunWriter{gsoEnabled: true}
 	c := newTestUDPCoalescer(t, w)
 	pay := make([]byte, 1200)
-	for i := 0; i < 3; i++ {
+	for range 3 {
 		if err := c.Commit(buildUDPv4(1000, 53, pay)); err != nil {
 			t.Fatal(err)
 		}
@@ -259,7 +259,7 @@ func TestUDPCoalescerCapsAtMaxSegs(t *testing.T) {
 	w := &fakeTunWriter{gsoEnabled: true}
 	c := newTestUDPCoalescer(t, w)
 	pay := make([]byte, 100)
-	for i := 0; i < udpCoalesceMaxSegs+5; i++ {
+	for range udpCoalesceMaxSegs + 5 {
 		if err := c.Commit(buildUDPv4(1000, 53, pay)); err != nil {
 			t.Fatal(err)
 		}
@@ -317,7 +317,7 @@ func TestUDPCoalescerIPv6Coalesces(t *testing.T) {
 	w := &fakeTunWriter{gsoEnabled: true}
 	c := newTestUDPCoalescer(t, w)
 	pay := make([]byte, 1200)
-	for i := 0; i < 3; i++ {
+	for range 3 {
 		if err := c.Commit(buildUDPv6(1000, 53, pay)); err != nil {
 			t.Fatal(err)
 		}

overlay/checksum/checksum_test.go

@@ -151,7 +151,7 @@ func TestChecksumTailPaths(t *testing.T) {
 			offsets := []int{0, 1, 3, 7, 15} // mix of aligned and odd starts
 
 			for k := 0; k <= maxK; k++ {
-				for tail := 0; tail < 64; tail++ {
+				for tail := range 64 {
 					length := 64*k + tail
 					for _, seed := range seeds {
 						for _, off := range offsets {

overlay/network_category_windows.go

@@ -1,5 +1,4 @@
 //go:build !e2e_testing
-// +build !e2e_testing
 
 package overlay
 

overlay/network_category_windows_test.go

@@ -1,5 +1,4 @@
 //go:build !e2e_testing
-// +build !e2e_testing
 
 package overlay
 

overlay/tio/blockon_linux.go

@@ -1,5 +1,4 @@
 //go:build linux && !android
-// +build linux,!android
 
 package tio
 

overlay/tio/queueset_gso_linux.go

@@ -1,5 +1,4 @@
 //go:build linux && !android
-// +build linux,!android
 
 package tio
 

overlay/tio/queueset_poll_linux.go

@@ -1,5 +1,4 @@
 //go:build linux && !android
-// +build linux,!android
 
 package tio
 

overlay/tio/tio_gso_linux.go

@@ -1,5 +1,4 @@
 //go:build linux && !android
-// +build linux,!android
 
 package tio
 

overlay/tio/tio_poll_linux.go

@@ -1,5 +1,4 @@
 //go:build linux && !android
-// +build linux,!android
 
 package tio
 

overlay/tio/tun_file_linux_test.go

@@ -1,5 +1,4 @@
 //go:build linux && !android && !e2e_testing
-// +build linux,!android,!e2e_testing
 
 package tio
 
@@ -117,17 +116,15 @@ func TestPoll_ConcurrentWrite_NoRace(t *testing.T) {
 	}()
 
 	var wg sync.WaitGroup
-	for w := 0; w < writers; w++ {
-		wg.Add(1)
-		go func() {
-			defer wg.Done()
-			for i := 0; i < perWriter; i++ {
+	for range writers {
+		wg.Go(func() {
+			for range perWriter {
 				if _, werr := p.Write(payload); werr != nil {
 					t.Errorf("write: %v", werr)
 					return
 				}
 			}
-		}()
+		})
 	}
 	wg.Wait()
 

overlay/tio/tun_linux_offload.go

@@ -1,5 +1,4 @@
 //go:build linux && !android
-// +build linux,!android
 
 package tio
 

overlay/tio/tun_linux_offload_test.go

@@ -1,5 +1,4 @@
 //go:build linux && !android && !e2e_testing
-// +build linux,!android,!e2e_testing
 
 package tio
 
@@ -137,7 +136,7 @@ func buildTSOv4(t *testing.T, payLen, mss int) ([]byte, virtio.Hdr) {
 	binary.BigEndian.PutUint16(pkt[34:36], 65535) // window
 
 	// payload
-	for i := 0; i < payLen; i++ {
+	for i := range payLen {
 		pkt[ipLen+tcpLen+i] = byte(i & 0xff)
 	}
 	return pkt, virtio.NewHeader(
@@ -257,7 +256,7 @@ func TestSegmentTCPv6(t *testing.T) {
 	pkt[53] = 0x19 // FIN | ACK | PSH — exercise FIN clearing too
 	binary.BigEndian.PutUint16(pkt[54:56], 65535)
 
-	for i := 0; i < payLen; i++ {
+	for i := range payLen {
 		pkt[ipLen+tcpLen+i] = byte(i)
 	}
 
@@ -361,7 +360,7 @@ func buildUSOv4(t *testing.T, payLen, gsoSize int) ([]byte, virtio.Hdr) {
 	binary.BigEndian.PutUint16(pkt[22:24], 53)                    // dport
 	binary.BigEndian.PutUint16(pkt[24:26], uint16(udpLen+payLen)) // superpacket length
 
-	for i := 0; i < payLen; i++ {
+	for i := range payLen {
 		pkt[ipLen+udpLen+i] = byte(i & 0xff)
 	}
 
@@ -473,7 +472,7 @@ func TestSegmentUDPv6(t *testing.T) {
 	// Superpacket-wide length, as the kernel supplies it; see buildUSOv4.
 	binary.BigEndian.PutUint16(pkt[44:46], uint16(udpLen+payLen))
 
-	for i := 0; i < payLen; i++ {
+	for i := range payLen {
 		pkt[ipLen+udpLen+i] = byte(i)
 	}
 
@@ -772,7 +771,7 @@ func buildTSOv6(payLen, gso int) []byte {
 	pkt[53] = 0x10 // ACK only
 	binary.BigEndian.PutUint16(pkt[54:56], 65535)
 
-	for i := 0; i < payLen; i++ {
+	for i := range payLen {
 		pkt[ipLen+tcpLen+i] = byte(i)
 	}
 	return pkt

overlay/tio/virtio/header_linux.go

@@ -1,5 +1,4 @@
 //go:build linux && !android
-// +build linux,!android
 
 package virtio
 

overlay/tio/virtio/segment_linux.go

@@ -1,5 +1,4 @@
 //go:build linux && !android
-// +build linux,!android
 
 // Package virtio implements the pure validation, header-correction, and
 // per-segment slicing logic for kernel-supplied TSO/USO superpackets on
@@ -254,12 +253,9 @@ func SegmentTCP(pkt []byte, hdrLenU, csumStartU, gsoSizeU uint16, yield func(seg
 	var savedHdr [maxSegHdrLen]byte
 	copy(savedHdr[:headerLen], pkt[:headerLen])
 
-	for i := 0; i < numSeg; i++ {
+	for i := range numSeg {
 		segStart := i * gsoSize
-		segEnd := segStart + gsoSize
-		if segEnd > payLen {
-			segEnd = payLen
-		}
+		segEnd := min(segStart+gsoSize, payLen)
 		segPayLen := segEnd - segStart
 		segLen := headerLen + segPayLen
 		headerOff := i * gsoSize
@@ -359,12 +355,9 @@ func SegmentUDP(pkt []byte, hdrLenU, csumStartU, gsoSizeU uint16, yield func(seg
 	var savedHdr [maxSegHdrLen]byte
 	copy(savedHdr[:headerLen], pkt[:headerLen])
 
-	for i := 0; i < numSeg; i++ {
+	for i := range numSeg {
 		segStart := i * gsoSize
-		segEnd := segStart + gsoSize
-		if segEnd > payLen {
-			segEnd = payLen
-		}
+		segEnd := min(segStart+gsoSize, payLen)
 		segPayLen := segEnd - segStart
 		segLen := headerLen + segPayLen
 		headerOff := i * gsoSize

overlay/tio/virtio/segment_linux_test.go

@@ -1,5 +1,4 @@
 //go:build linux && !android
-// +build linux,!android
 
 package virtio
 
@@ -58,7 +57,7 @@ func buildTCPv4Super(payLen int) (pkt []byte, hdrLen, csumStart uint16) {
 	pkt[33] = 0x18                                // ACK | PSH
 	binary.BigEndian.PutUint16(pkt[34:36], 65535) // window
 
-	for i := 0; i < payLen; i++ {
+	for i := range payLen {
 		pkt[ipLen+tcpLen+i] = byte(i & 0xff)
 	}
 	return pkt, ipLen + tcpLen, ipLen
@@ -82,7 +81,7 @@ func buildUDPv4Super(payLen int) (pkt []byte, hdrLen, csumStart uint16) {
 	binary.BigEndian.PutUint16(pkt[20:22], 12345) // sport
 	binary.BigEndian.PutUint16(pkt[22:24], 53)    // dport
 
-	for i := 0; i < payLen; i++ {
+	for i := range payLen {
 		pkt[ipLen+udpLen+i] = byte(i & 0xff)
 	}
 	return pkt, ipLen + udpLen, ipLen
@@ -188,7 +187,7 @@ func TestSegmentTCPHeaderNotCorrupted(t *testing.T) {
 				// Payload bytes must be the original contiguous slice.
 				segPayLen := len(seg) - int(hdrLen)
 				wantPay := make([]byte, segPayLen)
-				for k := 0; k < segPayLen; k++ {
+				for k := range segPayLen {
 					wantPay[k] = byte((off + k) & 0xff)
 				}
 				if !bytes.Equal(seg[hdrLen:], wantPay) {
@@ -317,7 +316,7 @@ func TestSegmentUDPHeaderNotCorrupted(t *testing.T) {
 				}
 
 				wantPay := make([]byte, segPayLen)
-				for k := 0; k < segPayLen; k++ {
+				for k := range segPayLen {
 					wantPay[k] = byte((off + k) & 0xff)
 				}
 				if !bytes.Equal(seg[hdrLen:], wantPay) {
@@ -365,7 +364,7 @@ func buildUDPv4Single(payload []byte) (pkt []byte, hdr Hdr) {
 // 0xffff, because all-zero is the reserved "no checksum" encoding that IPv6 rejects outright.
 func TestFinishChecksumUDPZeroStoresAllOnes(t *testing.T) {
 	var payload []byte
-	for i := 0; i < 0x10000; i++ {
+	for i := range 0x10000 {
 		p := []byte{byte(i >> 8), byte(i)}
 		pkt, hdr := buildUDPv4Single(p)
 		cs, co := int(hdr.CsumStart), int(hdr.CsumOffset)
@@ -544,7 +543,7 @@ func TestBaseSumsMatchZeroingReference(t *testing.T) {
 
 	t.Run("ipv4", func(t *testing.T) {
 		for ihl := ipv4HeaderMinLen; ihl <= ipv4HeaderMaxLen; ihl += 4 {
-			for iter := 0; iter < 5000; iter++ {
+			for range 5000 {
 				pkt := make([]byte, ihl)
 				for i := range pkt {
 					pkt[i] = randByte(&state)
@@ -574,7 +573,7 @@ func TestBaseSumsMatchZeroingReference(t *testing.T) {
 		for dataOff := 5; dataOff <= 15; dataOff++ {
 			tcpLen := dataOff * 4
 			headerLen := csumStart + tcpLen
-			for iter := 0; iter < 5000; iter++ {
+			for range 5000 {
 				pkt := make([]byte, headerLen+64)
 				for i := range pkt {
 					pkt[i] = randByte(&state)

overlay/tun.go

@@ -93,14 +93,14 @@ func prefixToMask(prefix netip.Prefix) netip.Addr {
 }
 
 func flipBytes(b []byte) []byte {
-	for i := 0; i < len(b); i++ {
+	for i := range b {
 		b[i] ^= 0xFF
 	}
 	return b
 }
 func orBytes(a []byte, b []byte) []byte {
 	ret := make([]byte, len(a))
-	for i := 0; i < len(a); i++ {
+	for i := range a {
 		ret[i] = a[i] | b[i]
 	}
 	return ret

overlay/tun_android.go

@@ -1,5 +1,4 @@
 //go:build !e2e_testing
-// +build !e2e_testing
 
 package overlay
 

overlay/tun_bypass_windows_386.go

@@ -1,5 +1,4 @@
 //go:build !e2e_testing
-// +build !e2e_testing
 
 package overlay
 

overlay/tun_darwin.go

@@ -1,5 +1,4 @@
 //go:build !ios && !e2e_testing
-// +build !ios,!e2e_testing
 
 package overlay
 

overlay/tun_freebsd.go

@@ -1,5 +1,4 @@
 //go:build !e2e_testing
-// +build !e2e_testing
 
 package overlay
 

overlay/tun_ios.go

@@ -1,5 +1,4 @@
 //go:build ios && !e2e_testing
-// +build ios,!e2e_testing
 
 package overlay
 

overlay/tun_linux.go

@@ -1,5 +1,4 @@
 //go:build !android && !e2e_testing
-// +build !android,!e2e_testing
 
 package overlay
 
@@ -548,7 +547,7 @@ func (t *tun) setDefaultRoute(cidr netip.Prefix) error {
 	if err != nil {
 		t.l.Warn("Failed to set default route MTU, retrying", "error", err, "cidr", cidr)
 		//retry twice more -- on some systems there appears to be a race condition where if we set routes too soon, netlink says `invalid argument`
-		for i := 0; i < 2; i++ {
+		for range 2 {
 			time.Sleep(100 * time.Millisecond)
 			err = netlink.RouteReplace(&nr)
 			if err == nil {

overlay/tun_linux_test.go

@@ -1,5 +1,4 @@
 //go:build !e2e_testing
-// +build !e2e_testing
 
 package overlay
 

overlay/tun_netbsd.go

@@ -1,5 +1,4 @@
 //go:build !e2e_testing
-// +build !e2e_testing
 
 package overlay
 

overlay/tun_notwin.go

@@ -1,5 +1,4 @@
 //go:build !windows
-// +build !windows
 
 package overlay
 

overlay/tun_openbsd.go

@@ -1,5 +1,4 @@
 //go:build !e2e_testing
-// +build !e2e_testing
 
 package overlay
 

overlay/tun_tester.go

@@ -1,5 +1,4 @@
 //go:build e2e_testing
-// +build e2e_testing
 
 package overlay
 

overlay/tun_windows.go

@@ -1,5 +1,4 @@
 //go:build !e2e_testing
-// +build !e2e_testing
 
 package overlay
 
@@ -11,7 +10,6 @@ import (
 	"os"
 	"path/filepath"
 	"runtime"
-	"slices"
 	"sync/atomic"
 	"syscall"
 	"unsafe"
@@ -183,7 +181,6 @@ func (t *winTun) addRoutes(logErrors bool) error {
 	luid := winipcfg.LUID(t.tun.LUID())
 	routes := *t.Routes.Load()
 	foundDefault4 := false
-	carriesV6 := slices.ContainsFunc(t.vpnNetworks, func(p netip.Prefix) bool { return p.Addr().Is6() })
 
 	for _, r := range routes {
 		if len(r.Via) == 0 || !r.Install {
@@ -191,9 +188,6 @@ func (t *winTun) addRoutes(logErrors bool) error {
 			continue
 		}
 
-		// A v6 unsafe_route is legal under a v4-only cert; uninstalled ones put nothing on the adapter.
-		carriesV6 = carriesV6 || r.Cidr.Addr().Is6()
-
 		// Add our unsafe route as an on-link route to the nebula tun device.
 		err := luid.AddRoute(r.Cidr, unspecifiedNextHop(r.Cidr), uint32(r.Metric))
 		if err != nil {
@@ -215,11 +209,6 @@ func (t *winTun) addRoutes(logErrors bool) error {
 		}
 	}
 
-	return t.setMTU(luid, foundDefault4, carriesV6)
-}
-
-// setMTU applies tun.mtu per address family. The default route metric rides along on the v4 handle.
-func (t *winTun) setMTU(luid winipcfg.LUID, foundDefault4, carriesV6 bool) error {
 	ipif, err := luid.IPInterface(windows.AF_INET)
 	if err != nil {
 		return fmt.Errorf("failed to get ip interface: %w", err)
@@ -234,25 +223,6 @@ func (t *winTun) setMTU(luid winipcfg.LUID, foundDefault4, carriesV6 bool) error
 	if err := ipif.Set(); err != nil {
 		return fmt.Errorf("failed to set ip interface: %w", err)
 	}
-
-	// Windows tracks NLMTU per family and wintun sets neither, so v6 keeps the adapter default of 65535.
-	// Gated so a v4-only overlay under 1280 boots; a v6 one deliberately does not, as linux also refuses.
-	if !carriesV6 {
-		return nil
-	}
-
-	ipif6, err := luid.IPInterface(windows.AF_INET6)
-	if err != nil {
-		// No v6 on the adapter means there is no NLMTU to get wrong. A failed Set below is not the same thing.
-		t.l.Info("Skipping ipv6 MTU, no ipv6 interface on this adapter", "error", err)
-		return nil
-	}
-
-	ipif6.NLMTU = uint32(t.MTU)
-	if err := ipif6.Set(); err != nil {
-		return fmt.Errorf("failed to set ipv6 interface: %w", err)
-	}
-
 	return nil
 }
 

overlay/user_test.go

@@ -108,7 +108,7 @@ func TestUserDeviceReadersConcurrentRace(t *testing.T) {
 	var wg sync.WaitGroup
 	run := func(idx int) {
 		defer wg.Done()
-		for i := 0; i < iterations; i++ {
+		for range iterations {
 			pkts, err := readers[idx].Read()
 			if err != nil {
 				errs <- err
@@ -136,7 +136,7 @@ func TestUserDeviceReadersConcurrentRace(t *testing.T) {
 	// waiting reader's private buffer, so reusing buf between writes is safe.
 	go func() {
 		buf := make([]byte, 32)
-		for i := 0; i < 2*iterations; i++ {
+		for i := range 2 * iterations {
 			for j := range buf {
 				buf[j] = byte(i + j)
 			}

routing/balance_test.go

@@ -27,7 +27,7 @@ func TestPacketsAreBalancedEqually(t *testing.T) {
 	gw3count := 0
 
 	iterationCount := uint16(65535)
-	for i := uint16(0); i < iterationCount; i++ {
+	for i := range iterationCount {
 		packet := firewall.Packet{
 			LocalAddr:  netip.MustParseAddr("192.168.1.1"),
 			RemoteAddr: netip.MustParseAddr("10.0.0.1"),
@@ -74,7 +74,7 @@ func TestPacketsAreBalancedByPriority(t *testing.T) {
 	gw2count := 0
 
 	iterationCount := uint16(65535)
-	for i := uint16(0); i < iterationCount; i++ {
+	for i := range iterationCount {
 		packet := firewall.Packet{
 			LocalAddr:  netip.MustParseAddr("192.168.1.1"),
 			RemoteAddr: netip.MustParseAddr("10.0.0.1"),
@@ -115,7 +115,7 @@ func TestBalancePacketDistributsRandomlyAndReturnsFalseIfBucketsNotCalculated(t
 	gw1count := 0
 	gw2count := 0
 
-	for i := uint16(0); i < iterationCount; i++ {
+	for i := range iterationCount {
 		packet := firewall.Packet{
 			LocalAddr:  netip.MustParseAddr("192.168.1.1"),
 			RemoteAddr: netip.MustParseAddr("10.0.0.1"),

routing/gateway.go

@@ -3,6 +3,7 @@ package routing
 import (
 	"fmt"
 	"net/netip"
+	"strings"
 )
 
 const (
@@ -13,14 +14,14 @@ const (
 type Gateways []Gateway
 
 func (g Gateways) String() string {
-	str := ""
+	var str strings.Builder
 	for i, gw := range g {
-		str += gw.String()
+		str.WriteString(gw.String())
 		if i < len(g)-1 {
-			str += ", "
+			str.WriteString(", ")
 		}
 	}
-	return str
+	return str.String()
 }
 
 type Gateway struct {

scheduler_test.go

@@ -1,21 +1,19 @@
 package nebula
 
 import (
-	"context"
 	"testing"
 	"time"
 )
 
 func TestScheduler_PooledReuse(t *testing.T) {
-	ctx, cancel := context.WithCancel(context.Background())
-	defer cancel()
+	ctx := t.Context()
 
 	s := NewScheduler[int](16)
 	delivered := make(chan int, 256)
 	go s.Run(ctx, func(item int) { delivered <- item })
 
 	const N = 100
-	for i := 0; i < N; i++ {
+	for i := range N {
 		s.Schedule(ctx, i, time.Millisecond)
 	}
 
@@ -34,8 +32,7 @@ func TestScheduler_PooledReuse(t *testing.T) {
 // BenchmarkScheduler_Schedule reports allocations per Schedule call.
 // In steady state the Scheduler's sync.Pool means we should see zero allocs per op once the pool warms up.
 func BenchmarkScheduler_Schedule(b *testing.B) {
-	ctx, cancel := context.WithCancel(context.Background())
-	defer cancel()
+	ctx := b.Context()
 
 	s := NewScheduler[int](b.N)
 	go s.Run(ctx, func(int) {})
@@ -51,8 +48,7 @@ func BenchmarkScheduler_Schedule(b *testing.B) {
 // What we'd pay per Schedule if Punchy called time.AfterFunc directly without the pooled Scheduler.
 // Allocates a *time.Timer plus a closure each call.
 func BenchmarkBareAfterFunc(b *testing.B) {
-	ctx, cancel := context.WithCancel(context.Background())
-	defer cancel()
+	ctx := b.Context()
 
 	queue := make(chan int, b.N)
 	go func() {

ssh.go

@@ -1,19 +1,62 @@
 package nebula
 
-// Configuration and lifecycle for the ssh debug console. The commands it serves are not
-// defined here; see commands.go, which registers them for every transport.
-
 import (
+	"bytes"
+	"encoding/json"
+	"errors"
+	"flag"
 	"fmt"
 	"log/slog"
+	"maps"
 	"net"
+	"net/netip"
 	"os"
+	"path/filepath"
+	"runtime"
+	"runtime/pprof"
+	"sort"
+	"strconv"
 	"strings"
 
 	"github.com/slackhq/nebula/config"
+	"github.com/slackhq/nebula/header"
+	"github.com/slackhq/nebula/logging"
 	"github.com/slackhq/nebula/sshd"
 )
 
+type sshListHostMapFlags struct {
+	Json    bool
+	Pretty  bool
+	ByIndex bool
+}
+
+type sshPrintCertFlags struct {
+	Json   bool
+	Pretty bool
+	Raw    bool
+}
+
+type sshPrintTunnelFlags struct {
+	Pretty bool
+}
+
+type sshChangeRemoteFlags struct {
+	Address string
+}
+
+type sshCloseTunnelFlags struct {
+	LocalOnly bool
+}
+
+type sshCreateTunnelFlags struct {
+	Address string
+}
+
+type sshDeviceInfoFlags struct {
+	Json   bool
+	Pretty bool
+}
+
 func wireSSHReload(l *slog.Logger, ssh *sshd.SSHServer, c *config.C) {
 	c.RegisterReloadCallback(func(c *config.C) {
 		if c.GetBool("sshd.enabled", false) {
@@ -154,3 +197,862 @@ func configSSH(l *slog.Logger, ssh *sshd.SSHServer, c *config.C) (func(), error)
 
 	return runner, nil
 }
+
+func attachCommands(l *slog.Logger, c *config.C, ssh *sshd.SSHServer, f *Interface) {
+	// sandboxDir defaults to a dir in temp. The intention is that end user will
+	// create this dir as needed. Overriding this config value to "" allows
+	// writing to anywhere in the system.
+	defaultDir := filepath.Join(os.TempDir(), "nebula-debug")
+	sandboxDir := c.GetString("sshd.sandbox_dir", defaultDir)
+
+	ssh.RegisterCommand(&sshd.Command{
+		Name:             "list-hostmap",
+		ShortDescription: "List all known previously connected hosts",
+		Flags: func() (*flag.FlagSet, any) {
+			fl := flag.NewFlagSet("", flag.ContinueOnError)
+			s := sshListHostMapFlags{}
+			fl.BoolVar(&s.Json, "json", false, "outputs as json with more information")
+			fl.BoolVar(&s.Pretty, "pretty", false, "pretty prints json, assumes -json")
+			fl.BoolVar(&s.ByIndex, "by-index", false, "gets all hosts in the hostmap from the index table")
+			return fl, &s
+		},
+		Callback: func(fs any, a []string, w sshd.StringWriter) error {
+			return sshListHostMap(f.hostMap, fs, w)
+		},
+	})
+
+	ssh.RegisterCommand(&sshd.Command{
+		Name:             "list-pending-hostmap",
+		ShortDescription: "List all handshaking hosts",
+		Flags: func() (*flag.FlagSet, any) {
+			fl := flag.NewFlagSet("", flag.ContinueOnError)
+			s := sshListHostMapFlags{}
+			fl.BoolVar(&s.Json, "json", false, "outputs as json with more information")
+			fl.BoolVar(&s.Pretty, "pretty", false, "pretty prints json, assumes -json")
+			fl.BoolVar(&s.ByIndex, "by-index", false, "gets all hosts in the hostmap from the index table")
+			return fl, &s
+		},
+		Callback: func(fs any, a []string, w sshd.StringWriter) error {
+			return sshListHostMap(f.handshakeManager, fs, w)
+		},
+	})
+
+	ssh.RegisterCommand(&sshd.Command{
+		Name:             "list-lighthouse-addrmap",
+		ShortDescription: "List all lighthouse map entries",
+		Flags: func() (*flag.FlagSet, any) {
+			fl := flag.NewFlagSet("", flag.ContinueOnError)
+			s := sshListHostMapFlags{}
+			fl.BoolVar(&s.Json, "json", false, "outputs as json with more information")
+			fl.BoolVar(&s.Pretty, "pretty", false, "pretty prints json, assumes -json")
+			return fl, &s
+		},
+		Callback: func(fs any, a []string, w sshd.StringWriter) error {
+			return sshListLighthouseMap(f.lightHouse, fs, w)
+		},
+	})
+
+	ssh.RegisterCommand(&sshd.Command{
+		Name:             "reload",
+		ShortDescription: "Reloads configuration from disk, same as sending HUP to the process",
+		Callback: func(fs any, a []string, w sshd.StringWriter) error {
+			return sshReload(c, w)
+		},
+	})
+
+	ssh.RegisterCommand(&sshd.Command{
+		Name:             "start-cpu-profile",
+		ShortDescription: "Starts a cpu profile and write output to the provided file, ex: `cpu-profile.pb.gz`",
+		Callback: func(fs any, a []string, w sshd.StringWriter) error {
+			return sshStartCpuProfile(sandboxDir, fs, a, w)
+		},
+	})
+
+	ssh.RegisterCommand(&sshd.Command{
+		Name:             "stop-cpu-profile",
+		ShortDescription: "Stops a cpu profile and writes output to the previously provided file",
+		Callback: func(fs any, a []string, w sshd.StringWriter) error {
+			pprof.StopCPUProfile()
+			return w.WriteLine("If a CPU profile was running it is now stopped")
+		},
+	})
+
+	ssh.RegisterCommand(&sshd.Command{
+		Name:             "save-heap-profile",
+		ShortDescription: "Saves a heap profile to the provided path, ex: `heap-profile.pb.gz`",
+		Callback: func(fs any, a []string, w sshd.StringWriter) error {
+			return sshGetHeapProfile(sandboxDir, fs, a, w)
+		},
+	})
+
+	ssh.RegisterCommand(&sshd.Command{
+		Name:             "mutex-profile-fraction",
+		ShortDescription: "Gets or sets runtime.SetMutexProfileFraction",
+		Callback:         sshMutexProfileFraction,
+	})
+
+	ssh.RegisterCommand(&sshd.Command{
+		Name:             "save-mutex-profile",
+		ShortDescription: "Saves a mutex profile to the provided path, ex: `mutex-profile.pb.gz`",
+		Callback: func(fs any, a []string, w sshd.StringWriter) error {
+			return sshGetMutexProfile(sandboxDir, fs, a, w)
+		},
+	})
+
+	ssh.RegisterCommand(&sshd.Command{
+		Name:             "log-level",
+		ShortDescription: "Gets or sets the current log level",
+		Callback: func(fs any, a []string, w sshd.StringWriter) error {
+			return sshLogLevel(l, fs, a, w)
+		},
+	})
+
+	ssh.RegisterCommand(&sshd.Command{
+		Name:             "log-format",
+		ShortDescription: "Gets or sets the current log format",
+		Callback: func(fs any, a []string, w sshd.StringWriter) error {
+			return sshLogFormat(l, fs, a, w)
+		},
+	})
+
+	ssh.RegisterCommand(&sshd.Command{
+		Name:             "version",
+		ShortDescription: "Prints the currently running version of nebula",
+		Callback: func(fs any, a []string, w sshd.StringWriter) error {
+			return sshVersion(f, fs, a, w)
+		},
+	})
+
+	ssh.RegisterCommand(&sshd.Command{
+		Name:             "device-info",
+		ShortDescription: "Prints information about the network device.",
+		Flags: func() (*flag.FlagSet, any) {
+			fl := flag.NewFlagSet("", flag.ContinueOnError)
+			s := sshDeviceInfoFlags{}
+			fl.BoolVar(&s.Json, "json", false, "outputs as json with more information")
+			fl.BoolVar(&s.Pretty, "pretty", false, "pretty prints json, assumes -json")
+			return fl, &s
+		},
+		Callback: func(fs any, a []string, w sshd.StringWriter) error {
+			return sshDeviceInfo(f, fs, w)
+		},
+	})
+
+	ssh.RegisterCommand(&sshd.Command{
+		Name:             "print-cert",
+		ShortDescription: "Prints the current certificate being used or the certificate for the provided vpn addr",
+		Flags: func() (*flag.FlagSet, any) {
+			fl := flag.NewFlagSet("", flag.ContinueOnError)
+			s := sshPrintCertFlags{}
+			fl.BoolVar(&s.Json, "json", false, "outputs as json")
+			fl.BoolVar(&s.Pretty, "pretty", false, "pretty prints json, assumes -json")
+			fl.BoolVar(&s.Raw, "raw", false, "raw prints the PEM encoded certificate, not compatible with -json or -pretty")
+			return fl, &s
+		},
+		Callback: func(fs any, a []string, w sshd.StringWriter) error {
+			return sshPrintCert(f, fs, a, w)
+		},
+	})
+
+	ssh.RegisterCommand(&sshd.Command{
+		Name:             "print-tunnel",
+		ShortDescription: "Prints json details about a tunnel for the provided vpn addr",
+		Flags: func() (*flag.FlagSet, any) {
+			fl := flag.NewFlagSet("", flag.ContinueOnError)
+			s := sshPrintTunnelFlags{}
+			fl.BoolVar(&s.Pretty, "pretty", false, "pretty prints json")
+			return fl, &s
+		},
+		Callback: func(fs any, a []string, w sshd.StringWriter) error {
+			return sshPrintTunnel(f, fs, a, w)
+		},
+	})
+
+	ssh.RegisterCommand(&sshd.Command{
+		Name:             "print-relays",
+		ShortDescription: "Prints json details about all relay info",
+		Flags: func() (*flag.FlagSet, any) {
+			fl := flag.NewFlagSet("", flag.ContinueOnError)
+			s := sshPrintTunnelFlags{}
+			fl.BoolVar(&s.Pretty, "pretty", false, "pretty prints json")
+			return fl, &s
+		},
+		Callback: func(fs any, a []string, w sshd.StringWriter) error {
+			return sshPrintRelays(f, fs, a, w)
+		},
+	})
+
+	ssh.RegisterCommand(&sshd.Command{
+		Name:             "change-remote",
+		ShortDescription: "Changes the remote address used in the tunnel for the provided vpn addr",
+		Flags: func() (*flag.FlagSet, any) {
+			fl := flag.NewFlagSet("", flag.ContinueOnError)
+			s := sshChangeRemoteFlags{}
+			fl.StringVar(&s.Address, "address", "", "The new remote address, ip:port")
+			return fl, &s
+		},
+		Callback: func(fs any, a []string, w sshd.StringWriter) error {
+			return sshChangeRemote(f, fs, a, w)
+		},
+	})
+
+	ssh.RegisterCommand(&sshd.Command{
+		Name:             "close-tunnel",
+		ShortDescription: "Closes a tunnel for the provided vpn addr",
+		Flags: func() (*flag.FlagSet, any) {
+			fl := flag.NewFlagSet("", flag.ContinueOnError)
+			s := sshCloseTunnelFlags{}
+			fl.BoolVar(&s.LocalOnly, "local-only", false, "Disables notifying the remote that the tunnel is shutting down")
+			return fl, &s
+		},
+		Callback: func(fs any, a []string, w sshd.StringWriter) error {
+			return sshCloseTunnel(f, fs, a, w)
+		},
+	})
+
+	ssh.RegisterCommand(&sshd.Command{
+		Name:             "create-tunnel",
+		ShortDescription: "Creates a tunnel for the provided vpn address",
+		Help:             "The lighthouses will be queried for real addresses but you can provide one as well.",
+		Flags: func() (*flag.FlagSet, any) {
+			fl := flag.NewFlagSet("", flag.ContinueOnError)
+			s := sshCreateTunnelFlags{}
+			fl.StringVar(&s.Address, "address", "", "Optionally provide a real remote address, ip:port ")
+			return fl, &s
+		},
+		Callback: func(fs any, a []string, w sshd.StringWriter) error {
+			return sshCreateTunnel(f, fs, a, w)
+		},
+	})
+
+	ssh.RegisterCommand(&sshd.Command{
+		Name:             "query-lighthouse",
+		ShortDescription: "Query the lighthouses for the provided vpn address",
+		Help:             "This command is asynchronous. Only currently known udp addresses will be printed.",
+		Callback: func(fs any, a []string, w sshd.StringWriter) error {
+			return sshQueryLighthouse(f, fs, a, w)
+		},
+	})
+}
+
+func sshListHostMap(hl controlHostLister, a any, w sshd.StringWriter) error {
+	fs, ok := a.(*sshListHostMapFlags)
+	if !ok {
+		return nil
+	}
+
+	var hm []ControlHostInfo
+	if fs.ByIndex {
+		hm = listHostMapIndexes(hl)
+	} else {
+		hm = listHostMapHosts(hl)
+	}
+
+	sort.Slice(hm, func(i, j int) bool {
+		return hm[i].VpnAddrs[0].Compare(hm[j].VpnAddrs[0]) < 0
+	})
+
+	if fs.Json || fs.Pretty {
+		js := json.NewEncoder(w.GetWriter())
+		if fs.Pretty {
+			js.SetIndent("", "    ")
+		}
+
+		err := js.Encode(hm)
+		if err != nil {
+			return nil
+		}
+
+	} else {
+		for _, v := range hm {
+			err := w.WriteLine(fmt.Sprintf("%s: %s", v.VpnAddrs, v.RemoteAddrs))
+			if err != nil {
+				return err
+			}
+		}
+	}
+
+	return nil
+}
+
+func sshListLighthouseMap(lightHouse *LightHouse, a any, w sshd.StringWriter) error {
+	fs, ok := a.(*sshListHostMapFlags)
+	if !ok {
+		return nil
+	}
+
+	type lighthouseInfo struct {
+		VpnAddr string    `json:"vpnAddr"`
+		Addrs   *CacheMap `json:"addrs"`
+	}
+
+	lightHouse.RLock()
+	addrMap := make([]lighthouseInfo, len(lightHouse.addrMap))
+	x := 0
+	for k, v := range lightHouse.addrMap {
+		addrMap[x] = lighthouseInfo{
+			VpnAddr: k.String(),
+			Addrs:   v.CopyCache(),
+		}
+		x++
+	}
+	lightHouse.RUnlock()
+
+	sort.Slice(addrMap, func(i, j int) bool {
+		return strings.Compare(addrMap[i].VpnAddr, addrMap[j].VpnAddr) < 0
+	})
+
+	if fs.Json || fs.Pretty {
+		js := json.NewEncoder(w.GetWriter())
+		if fs.Pretty {
+			js.SetIndent("", "    ")
+		}
+
+		err := js.Encode(addrMap)
+		if err != nil {
+			return nil
+		}
+
+	} else {
+		for _, v := range addrMap {
+			b, err := json.Marshal(v.Addrs)
+			if err != nil {
+				return err
+			}
+			err = w.WriteLine(fmt.Sprintf("%s: %s", v.VpnAddr, string(b)))
+			if err != nil {
+				return err
+			}
+		}
+	}
+
+	return nil
+}
+
+// sshSanitizeFilePath validates that the given file path is within the sandbox directory.
+// If sandboxDir is empty, the path is returned as-is for backwards compatibility.
+func sshSanitizeFilePath(sandboxDir, filePath string) (string, error) {
+	if sandboxDir == "" {
+		return filePath, nil
+	}
+
+	// Clean and resolve the path relative to the sandbox directory
+	if !filepath.IsAbs(filePath) {
+		filePath = filepath.Join(sandboxDir, filePath)
+	}
+	cleaned := filepath.Clean(filePath)
+
+	// Ensure the resolved path is within the sandbox directory
+	cleanedSandbox := filepath.Clean(sandboxDir)
+	if cleaned == cleanedSandbox {
+		return "", fmt.Errorf("path %q resolves to the sandbox directory itself %q", filePath, sandboxDir)
+	}
+	if !strings.HasPrefix(cleaned, cleanedSandbox+string(filepath.Separator)) {
+		return "", fmt.Errorf("path %q is outside the sandbox directory %q", filePath, sandboxDir)
+	}
+
+	return cleaned, nil
+}
+
+func sshStartCpuProfile(sandboxDir string, fs any, a []string, w sshd.StringWriter) error {
+	if len(a) == 0 {
+		err := w.WriteLine("No path to write profile provided")
+		return err
+	}
+
+	filePath, err := sshSanitizeFilePath(sandboxDir, a[0])
+	if err != nil {
+		return w.WriteLine(err.Error())
+	}
+
+	file, err := os.Create(filePath)
+	if err != nil {
+		err = w.WriteLine(fmt.Sprintf("Unable to create profile file: %s", err))
+		return err
+	}
+
+	err = pprof.StartCPUProfile(file)
+	if err != nil {
+		err = w.WriteLine(fmt.Sprintf("Unable to start cpu profile: %s", err))
+		return err
+	}
+
+	err = w.WriteLine(fmt.Sprintf("Started cpu profile, issue stop-cpu-profile to write the output to %s", a))
+	return err
+}
+
+func sshVersion(ifce *Interface, fs any, a []string, w sshd.StringWriter) error {
+	return w.WriteLine(fmt.Sprintf("%s", ifce.version))
+}
+
+func sshQueryLighthouse(ifce *Interface, fs any, a []string, w sshd.StringWriter) error {
+	if len(a) == 0 {
+		return w.WriteLine("No vpn address was provided")
+	}
+
+	vpnAddr, err := netip.ParseAddr(a[0])
+	if err != nil {
+		return w.WriteLine(fmt.Sprintf("The provided vpn address could not be parsed: %s", a[0]))
+	}
+
+	if !vpnAddr.IsValid() {
+		return w.WriteLine(fmt.Sprintf("The provided vpn address could not be parsed: %s", a[0]))
+	}
+
+	var cm *CacheMap
+	rl := ifce.lightHouse.Query(vpnAddr)
+	if rl != nil {
+		cm = rl.CopyCache()
+	}
+	return json.NewEncoder(w.GetWriter()).Encode(cm)
+}
+
+func sshCloseTunnel(ifce *Interface, fs any, a []string, w sshd.StringWriter) error {
+	flags, ok := fs.(*sshCloseTunnelFlags)
+	if !ok {
+		return nil
+	}
+
+	if len(a) == 0 {
+		return w.WriteLine("No vpn address was provided")
+	}
+
+	vpnAddr, err := netip.ParseAddr(a[0])
+	if err != nil {
+		return w.WriteLine(fmt.Sprintf("The provided vpn address could not be parsed: %s", a[0]))
+	}
+
+	if !vpnAddr.IsValid() {
+		return w.WriteLine(fmt.Sprintf("The provided vpn address could not be parsed: %s", a[0]))
+	}
+
+	hostInfo := ifce.hostMap.QueryVpnAddr(vpnAddr)
+	if hostInfo == nil {
+		return w.WriteLine(fmt.Sprintf("Could not find tunnel for vpn address: %v", a[0]))
+	}
+
+	if !flags.LocalOnly {
+		ifce.send(
+			header.CloseTunnel,
+			0,
+			hostInfo.ConnectionState,
+			hostInfo,
+			[]byte{},
+			make([]byte, 12, 12),
+			make([]byte, mtu),
+		)
+	}
+
+	ifce.closeTunnel(hostInfo)
+	return w.WriteLine("Closed")
+}
+
+func sshCreateTunnel(ifce *Interface, fs any, a []string, w sshd.StringWriter) error {
+	flags, ok := fs.(*sshCreateTunnelFlags)
+	if !ok {
+		return nil
+	}
+
+	if len(a) == 0 {
+		return w.WriteLine("No vpn address was provided")
+	}
+
+	vpnAddr, err := netip.ParseAddr(a[0])
+	if err != nil {
+		return w.WriteLine(fmt.Sprintf("The provided vpn address could not be parsed: %s", a[0]))
+	}
+
+	if !vpnAddr.IsValid() {
+		return w.WriteLine(fmt.Sprintf("The provided vpn address could not be parsed: %s", a[0]))
+	}
+
+	hostInfo := ifce.hostMap.QueryVpnAddr(vpnAddr)
+	if hostInfo != nil {
+		return w.WriteLine(fmt.Sprintf("Tunnel already exists"))
+	}
+
+	hostInfo = ifce.handshakeManager.QueryVpnAddr(vpnAddr)
+	if hostInfo != nil {
+		return w.WriteLine(fmt.Sprintf("Tunnel already handshaking"))
+	}
+
+	var addr netip.AddrPort
+	if flags.Address != "" {
+		addr, err = netip.ParseAddrPort(flags.Address)
+		if err != nil {
+			return w.WriteLine("Address could not be parsed")
+		}
+	}
+
+	hostInfo = ifce.handshakeManager.StartHandshake(vpnAddr, nil)
+	if addr.IsValid() {
+		hostInfo.SetRemote(addr)
+	}
+
+	return w.WriteLine("Created")
+}
+
+func sshChangeRemote(ifce *Interface, fs any, a []string, w sshd.StringWriter) error {
+	flags, ok := fs.(*sshChangeRemoteFlags)
+	if !ok {
+		return nil
+	}
+
+	if len(a) == 0 {
+		return w.WriteLine("No vpn address was provided")
+	}
+
+	if flags.Address == "" {
+		return w.WriteLine("No address was provided")
+	}
+
+	addr, err := netip.ParseAddrPort(flags.Address)
+	if err != nil {
+		return w.WriteLine("Address could not be parsed")
+	}
+
+	vpnAddr, err := netip.ParseAddr(a[0])
+	if err != nil {
+		return w.WriteLine(fmt.Sprintf("The provided vpn address could not be parsed: %s", a[0]))
+	}
+
+	if !vpnAddr.IsValid() {
+		return w.WriteLine(fmt.Sprintf("The provided vpn address could not be parsed: %s", a[0]))
+	}
+
+	hostInfo := ifce.hostMap.QueryVpnAddr(vpnAddr)
+	if hostInfo == nil {
+		return w.WriteLine(fmt.Sprintf("Could not find tunnel for vpn address: %v", a[0]))
+	}
+
+	hostInfo.SetRemote(addr)
+	return w.WriteLine("Changed")
+}
+
+func sshGetHeapProfile(sandboxDir string, fs any, a []string, w sshd.StringWriter) error {
+	if len(a) == 0 {
+		return w.WriteLine("No path to write profile provided")
+	}
+
+	filePath, err := sshSanitizeFilePath(sandboxDir, a[0])
+	if err != nil {
+		return w.WriteLine(err.Error())
+	}
+
+	file, err := os.Create(filePath)
+	if err != nil {
+		err = w.WriteLine(fmt.Sprintf("Unable to create profile file: %s", err))
+		return err
+	}
+
+	err = pprof.WriteHeapProfile(file)
+	if err != nil {
+		err = w.WriteLine(fmt.Sprintf("Unable to write profile: %s", err))
+		return err
+	}
+
+	err = w.WriteLine(fmt.Sprintf("Mem profile created at %s", a))
+	return err
+}
+
+func sshMutexProfileFraction(fs any, a []string, w sshd.StringWriter) error {
+	if len(a) == 0 {
+		rate := runtime.SetMutexProfileFraction(-1)
+		return w.WriteLine(fmt.Sprintf("Current value: %d", rate))
+	}
+
+	newRate, err := strconv.Atoi(a[0])
+	if err != nil {
+		return w.WriteLine(fmt.Sprintf("Invalid argument: %s", a[0]))
+	}
+
+	oldRate := runtime.SetMutexProfileFraction(newRate)
+	return w.WriteLine(fmt.Sprintf("New value: %d. Old value: %d", newRate, oldRate))
+}
+
+func sshGetMutexProfile(sandboxDir string, fs any, a []string, w sshd.StringWriter) error {
+	if len(a) == 0 {
+		return w.WriteLine("No path to write profile provided")
+	}
+
+	filePath, err := sshSanitizeFilePath(sandboxDir, a[0])
+	if err != nil {
+		return w.WriteLine(err.Error())
+	}
+
+	file, err := os.Create(filePath)
+	if err != nil {
+		return w.WriteLine(fmt.Sprintf("Unable to create profile file: %s", err))
+	}
+	defer file.Close()
+
+	mutexProfile := pprof.Lookup("mutex")
+	if mutexProfile == nil {
+		return w.WriteLine("Unable to get pprof.Lookup(\"mutex\")")
+	}
+
+	err = mutexProfile.WriteTo(file, 0)
+	if err != nil {
+		return w.WriteLine(fmt.Sprintf("Unable to write profile: %s", err))
+	}
+
+	return w.WriteLine(fmt.Sprintf("Mutex profile created at %s", a))
+}
+
+func sshLogLevel(l *slog.Logger, fs any, a []string, w sshd.StringWriter) error {
+	ctrl, ok := l.Handler().(interface {
+		GetLevel() slog.Level
+		SetLevel(slog.Level)
+	})
+	if !ok {
+		return w.WriteLine("Log level is not reconfigurable on this logger")
+	}
+
+	if len(a) == 0 {
+		return w.WriteLine(fmt.Sprintf("Log level is: %s", logging.LevelName(ctrl.GetLevel())))
+	}
+
+	level, err := logging.ParseLevel(strings.ToLower(a[0]))
+	if err != nil {
+		return w.WriteLine(fmt.Sprintf("Unknown log level %s. Possible log levels: trace, debug, info, warn, error", a))
+	}
+
+	ctrl.SetLevel(level)
+	return w.WriteLine(fmt.Sprintf("Log level is: %s", logging.LevelName(ctrl.GetLevel())))
+}
+
+func sshLogFormat(l *slog.Logger, fs any, a []string, w sshd.StringWriter) error {
+	ctrl, ok := l.Handler().(interface {
+		GetFormat() string
+		SetFormat(string) error
+	})
+	if !ok {
+		return w.WriteLine("Log format is not reconfigurable on this logger")
+	}
+
+	if len(a) == 0 {
+		return w.WriteLine(fmt.Sprintf("Log format is: %s", ctrl.GetFormat()))
+	}
+
+	if err := ctrl.SetFormat(strings.ToLower(a[0])); err != nil {
+		return err
+	}
+	return w.WriteLine(fmt.Sprintf("Log format is: %s", ctrl.GetFormat()))
+}
+
+func sshPrintCert(ifce *Interface, fs any, a []string, w sshd.StringWriter) error {
+	args, ok := fs.(*sshPrintCertFlags)
+	if !ok {
+		return nil
+	}
+
+	cert := ifce.pki.getCertState().GetDefaultCertificate()
+	if len(a) > 0 {
+		vpnAddr, err := netip.ParseAddr(a[0])
+		if err != nil {
+			return w.WriteLine(fmt.Sprintf("The provided vpn addr could not be parsed: %s", a[0]))
+		}
+
+		if !vpnAddr.IsValid() {
+			return w.WriteLine(fmt.Sprintf("The provided vpn addr could not be parsed: %s", a[0]))
+		}
+
+		hostInfo := ifce.hostMap.QueryVpnAddr(vpnAddr)
+		if hostInfo == nil {
+			return w.WriteLine(fmt.Sprintf("Could not find tunnel for vpn addr: %v", a[0]))
+		}
+
+		cert = hostInfo.GetCert().Certificate
+	}
+
+	if args.Json || args.Pretty {
+		b, err := cert.MarshalJSON()
+		if err != nil {
+			return nil
+		}
+
+		if args.Pretty {
+			buf := new(bytes.Buffer)
+			err := json.Indent(buf, b, "", "    ")
+			b = buf.Bytes()
+			if err != nil {
+				return nil
+			}
+		}
+
+		return w.WriteBytes(b)
+	}
+
+	if args.Raw {
+		b, err := cert.MarshalPEM()
+		if err != nil {
+			return nil
+		}
+
+		return w.WriteBytes(b)
+	}
+
+	return w.WriteLine(cert.String())
+}
+
+func sshPrintRelays(ifce *Interface, fs any, a []string, w sshd.StringWriter) error {
+	args, ok := fs.(*sshPrintTunnelFlags)
+	if !ok {
+		w.WriteLine(fmt.Sprintf("sshPrintRelays failed to convert args type"))
+		return nil
+	}
+
+	relays := map[uint32]*HostInfo{}
+	ifce.hostMap.Lock()
+	maps.Copy(relays, ifce.hostMap.Relays)
+	ifce.hostMap.Unlock()
+
+	type RelayFor struct {
+		Error          error
+		Type           string
+		State          string
+		PeerAddr       netip.Addr
+		LocalIndex     uint32
+		RemoteIndex    uint32
+		RelayedThrough []netip.Addr
+	}
+
+	type RelayOutput struct {
+		NebulaAddr    netip.Addr
+		RelayForAddrs []RelayFor
+	}
+
+	type CmdOutput struct {
+		Relays []*RelayOutput
+	}
+
+	co := CmdOutput{}
+
+	enc := json.NewEncoder(w.GetWriter())
+
+	if args.Pretty {
+		enc.SetIndent("", "    ")
+	}
+
+	for k, v := range relays {
+		ro := RelayOutput{NebulaAddr: v.vpnAddrs[0]}
+		co.Relays = append(co.Relays, &ro)
+		relayHI := ifce.hostMap.QueryVpnAddr(v.vpnAddrs[0])
+		if relayHI == nil {
+			ro.RelayForAddrs = append(ro.RelayForAddrs, RelayFor{Error: errors.New("could not find hostinfo")})
+			continue
+		}
+		for _, vpnAddr := range relayHI.relayState.CopyRelayForIps() {
+			rf := RelayFor{Error: nil}
+			r, ok := relayHI.relayState.GetRelayForByAddr(vpnAddr)
+			if ok {
+				t := ""
+				switch r.Type {
+				case ForwardingType:
+					t = "forwarding"
+				case TerminalType:
+					t = "terminal"
+				default:
+					t = "unknown"
+				}
+
+				s := ""
+				switch r.State {
+				case Requested:
+					s = "requested"
+				case Established:
+					s = "established"
+				default:
+					s = "unknown"
+				}
+
+				rf.LocalIndex = r.LocalIndex
+				rf.RemoteIndex = r.RemoteIndex
+				rf.PeerAddr = r.PeerAddr
+				rf.Type = t
+				rf.State = s
+				if rf.LocalIndex != k {
+					rf.Error = fmt.Errorf("hostmap LocalIndex '%v' does not match RelayState LocalIndex", k)
+				}
+			}
+			relayedHI := ifce.hostMap.QueryVpnAddr(vpnAddr)
+			if relayedHI != nil {
+				rf.RelayedThrough = append(rf.RelayedThrough, relayedHI.relayState.CopyRelayIps()...)
+			}
+
+			ro.RelayForAddrs = append(ro.RelayForAddrs, rf)
+		}
+	}
+	err := enc.Encode(co)
+	if err != nil {
+		return err
+	}
+	return nil
+}
+
+func sshPrintTunnel(ifce *Interface, fs any, a []string, w sshd.StringWriter) error {
+	args, ok := fs.(*sshPrintTunnelFlags)
+	if !ok {
+		return nil
+	}
+
+	if len(a) == 0 {
+		return w.WriteLine("No vpn address was provided")
+	}
+
+	vpnAddr, err := netip.ParseAddr(a[0])
+	if err != nil {
+		return w.WriteLine(fmt.Sprintf("The provided vpn addr could not be parsed: %s", a[0]))
+	}
+
+	if !vpnAddr.IsValid() {
+		return w.WriteLine(fmt.Sprintf("The provided vpn addr could not be parsed: %s", a[0]))
+	}
+
+	hostInfo := ifce.hostMap.QueryVpnAddr(vpnAddr)
+	if hostInfo == nil {
+		return w.WriteLine(fmt.Sprintf("Could not find tunnel for vpn addr: %v", a[0]))
+	}
+
+	enc := json.NewEncoder(w.GetWriter())
+	if args.Pretty {
+		enc.SetIndent("", "    ")
+	}
+
+	return enc.Encode(copyHostInfo(hostInfo, ifce.hostMap.GetPreferredRanges()))
+}
+
+func sshDeviceInfo(ifce *Interface, fs any, w sshd.StringWriter) error {
+
+	data := struct {
+		Name string         `json:"name"`
+		Cidr []netip.Prefix `json:"cidr"`
+	}{
+		Name: ifce.inside.Name(),
+		Cidr: make([]netip.Prefix, len(ifce.inside.Networks())),
+	}
+
+	copy(data.Cidr, ifce.inside.Networks())
+
+	flags, ok := fs.(*sshDeviceInfoFlags)
+	if !ok {
+		return fmt.Errorf("internal error: expected flags to be sshDeviceInfoFlags but was %+v", fs)
+	}
+
+	if flags.Json || flags.Pretty {
+		js := json.NewEncoder(w.GetWriter())
+		if flags.Pretty {
+			js.SetIndent("", "    ")
+		}
+
+		return js.Encode(data)
+	} else {
+		return w.WriteLine(fmt.Sprintf("name=%v cidr=%v", data.Name, data.Cidr))
+	}
+}
+
+func sshReload(c *config.C, w sshd.StringWriter) error {
+	err := w.WriteLine("Reloading config")
+	c.ReloadConfig()
+	return err
+}

sshd/command.go

@@ -1,4 +1,4 @@
-package diag
+package sshd
 
 import (
 	"errors"
@@ -10,17 +10,6 @@ import (
 	"github.com/armon/go-radix"
 )
 
-var (
-	// ErrUnknownCommand is returned by the Registry when the first argument names no
-	// registered command. The user has already been told so on their writer.
-	ErrUnknownCommand = errors.New("unknown command")
-
-	// ErrUsage wraps a flag parsing failure. The flag package has already written the
-	// details to the caller's writer by the time this is returned, so a transport should
-	// use it only to pick an exit status.
-	ErrUsage = errors.New("usage")
-)
-
 // CommandFlags is a function called before help or command execution to parse command line flags
 // It should return a flag.FlagSet instance and a pointer to the struct that will contain parsed flags
 type CommandFlags func() (*flag.FlagSet, any)
@@ -55,10 +44,8 @@ func execCommand(c *Command, args []string, w StringWriter) error {
 			fl.SetOutput(w.GetWriter())
 			err := fl.Parse(args)
 			if err != nil {
-				// fl.Parse has dumped error information to the user via the w writer, so
-				// the wrapper exists purely so a transport can tell a usage problem from a
-				// command that ran and failed.
-				return fmt.Errorf("%w: %w", ErrUsage, err)
+				// fl.Parse has dumped error information to the user via the w writer.
+				return err
 			}
 			args = fl.Args()
 		}

sshd/server.go

@@ -9,9 +9,8 @@ import (
 	"net"
 	"sync"
 
+	"github.com/armon/go-radix"
 	"golang.org/x/crypto/ssh"
-
-	"github.com/slackhq/nebula/diag"
 )
 
 type SSHServer struct {
@@ -26,9 +25,10 @@ type SSHServer struct {
 	trustedKeys map[string]map[string]bool
 	trustedCAs  []ssh.PublicKey
 
-	// The commands this server serves. Shared with every other transport, see diag.Registry.
-	commands *diag.Registry
-	listener net.Listener
+	// List of available commands
+	helpCommand *Command
+	commands    *radix.Tree
+	listener    net.Listener
 
 	// ctx parents per-Run contexts. Cancelling it (e.g. via Control.Stop) tears the server down even
 	// across reloads, since each Run derives a fresh child rather than reusing this one directly.
@@ -38,11 +38,11 @@ type SSHServer struct {
 // NewSSHServer creates a new ssh server rigged with default commands and prepares to listen.
 // The ssh server's context is parented off the supplied ctx so cancelling it
 // (e.g. on Control.Stop) tears down active sessions and closes the listener.
-func NewSSHServer(ctx context.Context, l *slog.Logger, commands *diag.Registry) (*SSHServer, error) {
+func NewSSHServer(ctx context.Context, l *slog.Logger) (*SSHServer, error) {
 	s := &SSHServer{
 		trustedKeys: make(map[string]map[string]bool),
 		l:           l,
-		commands:    commands,
+		commands:    radix.New(),
 		ctx:         ctx,
 	}
 
@@ -90,6 +90,14 @@ func NewSSHServer(ctx context.Context, l *slog.Logger, commands *diag.Registry)
 		ServerVersion:     fmt.Sprintf("SSH-2.0-Nebula???"),
 	}
 
+	s.RegisterCommand(&Command{
+		Name:             "help",
+		ShortDescription: "prints available commands or help <command> for specific usage info",
+		Callback: func(a any, args []string, w StringWriter) error {
+			return helpCallback(s.commands, args, w)
+		},
+	})
+
 	return s, nil
 }
 
@@ -152,6 +160,11 @@ func (s *SSHServer) AddAuthorizedKey(user, pubKey string) error {
 	return nil
 }
 
+// RegisterCommand adds a command that can be run by a user, by default only `help` is available
+func (s *SSHServer) RegisterCommand(c *Command) {
+	s.commands.Insert(c.Name, c)
+}
+
 // Run begins listening and accepting connections. Each invocation derives a fresh per-Run context
 // from the constructor-supplied ctx so a Stop+Run sequence (used by config reload) starts clean
 // rather than carrying a permanently-cancelled context across runs.

sshd/session.go

@@ -1,38 +1,37 @@
 package sshd
 
 import (
+	"fmt"
 	"log/slog"
 	"sort"
 	"strings"
 
+	"github.com/anmitsu/go-shlex"
+	"github.com/armon/go-radix"
 	"golang.org/x/crypto/ssh"
 	"golang.org/x/term"
-
-	"github.com/slackhq/nebula/diag"
 )
 
 type session struct {
 	l        *slog.Logger
 	c        *ssh.ServerConn
 	term     *term.Terminal
-	commands *diag.Registry
+	commands *radix.Tree
 	cancel   func()
 }
 
-func NewSession(commands *diag.Registry, conn *ssh.ServerConn, chans <-chan ssh.NewChannel, cancel func(), l *slog.Logger) *session {
+func NewSession(commands *radix.Tree, conn *ssh.ServerConn, chans <-chan ssh.NewChannel, cancel func(), l *slog.Logger) *session {
 	s := &session{
-		// A copy, so the logout command this session adds for itself stays invisible to every
-		// other session and to `nebula ctl`.
-		commands: commands.Clone(),
+		commands: radix.NewFromMap(commands.ToMap()),
 		l:        l,
 		c:        conn,
 		cancel:   cancel,
 	}
 
-	s.commands.RegisterCommand(&diag.Command{
+	s.commands.Insert("logout", &Command{
 		Name:             "logout",
 		ShortDescription: "Ends the current session",
-		Callback: func(a any, args []string, w diag.StringWriter) error {
+		Callback: func(a any, args []string, w StringWriter) error {
 			s.Close()
 			return nil
 		},
@@ -88,11 +87,9 @@ func (s *session) handleRequests(in <-chan *ssh.Request, channel ssh.Channel) {
 			}
 
 			req.Reply(true, nil)
-			dErr := s.commands.Dispatch(payload.Value, diag.NewWriter(channel))
+			s.dispatchCommand(payload.Value, &stringWriter{channel})
 
-			// Report a real exit status rather than a hardcoded zero, so that
-			// `ssh nebula-host list-hostmap` is scriptable the same way `nebula ctl` is.
-			status := struct{ Status uint32 }{uint32(diag.StatusFor(dErr))}
+			status := struct{ Status uint32 }{uint32(0)}
 			channel.SendRequest("exit-status", false, ssh.Marshal(status))
 			channel.Close()
 			return
@@ -114,7 +111,7 @@ func (s *session) createTerm(channel ssh.Channel) *term.Terminal {
 	term.AutoCompleteCallback = func(line string, pos int, key rune) (newLine string, newPos int, ok bool) {
 		// key 9 is tab
 		if key == 9 {
-			cmds := s.commands.Match(line)
+			cmds := matchCommand(s.commands, line)
 			if len(cmds) == 1 {
 				return cmds[0] + " ", len(cmds[0]) + 1, true
 			}
@@ -131,19 +128,49 @@ func (s *session) createTerm(channel ssh.Channel) *term.Terminal {
 }
 
 func (s *session) handleInput() {
-	w := diag.NewWriter(s.term)
+	w := &stringWriter{w: s.term}
 	for {
 		line, err := s.term.ReadLine()
 		if err != nil {
 			break
 		}
 
-		// The interactive console reports problems on the terminal the user is already
-		// looking at, so the error is nothing extra to say here.
-		_ = s.commands.Dispatch(line, w)
+		s.dispatchCommand(line, w)
 	}
 }
 
+func (s *session) dispatchCommand(line string, w StringWriter) {
+	args, err := shlex.Split(line, true)
+	if err != nil {
+		return
+	}
+
+	if len(args) == 0 {
+		dumpCommands(s.commands, w)
+		return
+	}
+
+	c, err := lookupCommand(s.commands, args[0])
+	if err != nil {
+		return
+	}
+
+	if c == nil {
+		err := w.WriteLine(fmt.Sprintf("did not understand: %s", line))
+		_ = err
+
+		dumpCommands(s.commands, w)
+		return
+	}
+
+	if checkHelpArgs(args) {
+		s.dispatchCommand(fmt.Sprintf("%s %s", "help", c.Name), w)
+		return
+	}
+
+	_ = execCommand(c, args[1:], w)
+}
+
 func (s *session) Close() {
 	s.c.Close()
 	s.cancel()

sshd/writer.go

@@ -1,4 +1,4 @@
-package diag
+package sshd
 
 import "io"
 
@@ -30,9 +30,3 @@ func (w *stringWriter) WriteBytes(b []byte) error {
 func (w *stringWriter) GetWriter() io.Writer {
 	return w.w
 }
-
-// NewWriter adapts an io.Writer to the StringWriter commands are handed. Transports
-// implement their own framing behind w; the commands never know the difference.
-func NewWriter(w io.Writer) StringWriter {
-	return &stringWriter{w: w}
-}

test/assert.go

@@ -25,7 +25,7 @@ func AssertDeepCopyEqual(t *testing.T, a any, b any) {
 }
 
 func traverseDeepCopy(t *testing.T, v1 reflect.Value, v2 reflect.Value, name string) bool {
-	if v1.Type() == v2.Type() && v1.Type() == reflect.TypeOf(netip.Addr{}) {
+	if v1.Type() == v2.Type() && v1.Type() == reflect.TypeFor[netip.Addr]() {
 		// Ignore netip.Addr types since they reuse an interned global value
 		return false
 	}
@@ -72,7 +72,7 @@ func traverseDeepCopy(t *testing.T, v1 reflect.Value, v2 reflect.Value, name str
 		}
 		return traverseDeepCopy(t, v1.Elem(), v2.Elem(), name)
 
-	case reflect.Ptr:
+	case reflect.Pointer:
 		local := reflect.ValueOf(time.Local).Pointer()
 		if local == v1.Pointer() && local == v2.Pointer() {
 			return true

udp/netchange_darwin.go

@@ -1,5 +1,4 @@
 //go:build darwin && !ios && !e2e_testing
-// +build darwin,!ios,!e2e_testing
 
 package udp
 

udp/netchange_darwin_test.go

@@ -1,5 +1,4 @@
 //go:build darwin && !ios && !e2e_testing
-// +build darwin,!ios,!e2e_testing
 
 package udp
 

udp/netchange_generic.go

@@ -1,5 +1,4 @@
 //go:build !darwin || ios || e2e_testing
-// +build !darwin ios e2e_testing
 
 package udp
 

udp/udp_android.go

@@ -1,5 +1,4 @@
 //go:build !e2e_testing
-// +build !e2e_testing
 
 package udp
 

udp/udp_bypass_windows_386.go

@@ -1,5 +1,4 @@
 //go:build !e2e_testing
-// +build !e2e_testing
 
 package udp
 

udp/udp_darwin.go

@@ -1,5 +1,4 @@
 //go:build !e2e_testing
-// +build !e2e_testing
 
 package udp
 

udp/udp_linux.go

@@ -294,10 +294,7 @@ func deliverSegments(r EncReader, from netip.AddrPort, payload []byte, segSize i
 		return
 	}
 	for off := 0; off < len(payload); off += segSize {
-		end := off + segSize
-		if end > len(payload) {
-			end = len(payload)
-		}
+		end := min(off+segSize, len(payload))
 		r(from, payload[off:end:end])
 	}
 }
@@ -479,7 +476,7 @@ func NewUDPStatsEmitter(udpConns []Conn) func() {
 	return func() {
 		for i, gauges := range udpGauges {
 			if err := udpConns[i].(*StdConn).getMemInfo(&meminfo); err == nil {
-				for j := 0; j < unix.SK_MEMINFO_VARS; j++ {
+				for j := range unix.SK_MEMINFO_VARS {
 					gauges[j].Update(int64(meminfo[j]))
 				}
 			}

udp/udp_linux_fixes_test.go

@@ -107,7 +107,7 @@ func TestWriteBatchBadFamilyDeliversOthers(t *testing.T) {
 	got := map[string]bool{}
 	rx.SetReadDeadline(time.Now().Add(2 * time.Second))
 	buf := make([]byte, 64)
-	for i := 0; i < 2; i++ {
+	for i := range 2 {
 		n, _, rerr := rx.ReadFromUDPAddrPort(buf)
 		if rerr != nil {
 			t.Fatalf("expected 2 delivered packets, read #%d failed: %v", i+1, rerr)
@@ -161,7 +161,7 @@ func TestWriteBatchUnreachableDestDeliversOthers(t *testing.T) {
 	got := map[string]bool{}
 	rx.SetReadDeadline(time.Now().Add(2 * time.Second))
 	buf := make([]byte, 64)
-	for i := 0; i < 4; i++ {
+	for i := range 4 {
 		n, _, rerr := rx.ReadFromUDPAddrPort(buf)
 		if rerr != nil {
 			t.Fatalf("expected 4 delivered packets, read #%d failed: %v (got so far: %v)", i+1, rerr, got)
@@ -691,7 +691,7 @@ func TestGSOEngagesOnLoopback(t *testing.T) {
 	// The kernel must deliver the original datagram boundaries and bytes.
 	_ = rx.SetReadDeadline(time.Now().Add(5 * time.Second))
 	got := make([]byte, pktLen+1)
-	for i := 0; i < numPkts; i++ {
+	for i := range numPkts {
 		n, _, err := rx.ReadFromUDP(got)
 		if err != nil {
 			t.Fatalf("rx read %d: %v", i, err)
@@ -699,7 +699,7 @@ func TestGSOEngagesOnLoopback(t *testing.T) {
 		if n != pktLen {
 			t.Fatalf("rx read %d: len=%d want %d (kernel segmented at wrong boundary)", i, n, pktLen)
 		}
-		for j := 0; j < n; j++ {
+		for j := range n {
 			if got[j] != byte(i) {
 				t.Fatalf("rx read %d: byte %d = %#x, want %#x", i, j, got[j], byte(i))
 			}

udp/udp_linux_writebatch.go

@@ -112,7 +112,7 @@ func (w *batchWriter) prepareWriteMessages(n int, offloadsEnabled bool) {
 
 	w.cmsg = make([]byte, n*w.cmsgSpace)
 
-	for k := 0; k < n; k++ {
+	for k := range n {
 		base := k * w.cmsgSpace
 		seg := (*unix.Cmsghdr)(unsafe.Pointer(&w.cmsg[base]))
 		seg.Level = unix.SOL_UDP
@@ -214,7 +214,7 @@ func (w *batchWriter) WriteBatch(bufs [][]byte, addrs []netip.AddrPort) (int, er
 				break
 			}
 
-			for k := 0; k < runLen; k++ {
+			for k := range runLen {
 				b := bufs[i+k]
 				if len(b) == 0 {
 					w.iovs[iovIdx+k].Base = nil
@@ -318,10 +318,7 @@ func (w *batchWriter) planRun(bufs [][]byte, addrs []netip.AddrPort, start, iovB
 		return 1, segSize
 	}
 	dst := addrs[start]
-	maxLen := w.maxGSOSegments
-	if iovBudget < maxLen {
-		maxLen = iovBudget
-	}
+	maxLen := min(iovBudget, w.maxGSOSegments)
 	runLen := 1
 	total := segSize
 	for runLen < maxLen && start+runLen < len(bufs) {

udp/udp_linux_writebatch_alloc_test.go

@@ -64,13 +64,13 @@ func TestWriteBatchNoAllocs(t *testing.T) {
 				addrs = append(addrs, dst)
 			}
 			// GSO-eligible run with a short tail.
-			for k := 0; k < 8; k++ {
+			for range 8 {
 				add(payload, dstA)
 			}
 			add(short, dstA)
 			add(payload, dstA)
 			// Alternating destinations defeat coalescing entirely.
-			for k := 0; k < 4; k++ {
+			for k := range 4 {
 				dst := dstA
 				if k%2 == 0 {
 					dst = dstB

udp/udp_netbsd.go

@@ -1,5 +1,4 @@
 //go:build !e2e_testing
-// +build !e2e_testing
 
 package udp