Release: Yggdrasil 0.5.2

Co-authored-by: Neil Alexander <neilalexander@users.noreply.github.com>

.github/workflows/pkg.yml

@@ -16,7 +16,7 @@ jobs:
 
     name: Package (Debian, ${{ matrix.pkgarch }})
 
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-20.04
     steps:
       - uses: actions/checkout@v3
         with:
@@ -107,7 +107,7 @@ jobs:
 
     name: Package (Router, ${{ matrix.pkgarch }})
 
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-20.04
     steps:
       - uses: actions/checkout@v3
         with:

CHANGELOG.md

@@ -26,7 +26,32 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 - in case of vulnerabilities.
 -->
 
-## [0.5.0] - Release Candidate 1
+## [0.5.2] - 2023-11-06
+
+### Added
+
+* New `-publickey` command line option that prints the derived public key from a configuration file
+* Support for connecting to TLS peers via SOCKS with the new `sockstls://` link schema
+
+### Changed
+
+* Stabilise tree parent selection algorithm
+* Improved logging when the TUN interface fails to set up
+
+### Fixed
+
+* Fixed a panic that could occur when a connection reaches an inconsistent error state
+* The admin socket will now report more peering handshake error conditions in `getPeers`
+* Yggdrasil will no longer panic at startup when duplicate peers are configured
+* The `build` script will no longer incorrectly import `LDFLAGS` from the environment
+
+## [0.5.1] - 2023-10-28
+
+### Fixed
+
+* Fix the Debian package so that upgrades are handled more smoothly
+
+## [0.5.0] - 2023-10-28
 
 ### Added
 

cmd/genkeys/main.go

@@ -16,6 +16,7 @@ import (
 	"fmt"
 	"net"
 	"runtime"
+	"time"
 
 	"github.com/yggdrasil-network/yggdrasil-go/src/address"
 )
@@ -27,6 +28,8 @@ type keySet struct {
 
 func main() {
 	threads := runtime.GOMAXPROCS(0)
+	fmt.Println("Threads:", threads)
+	start := time.Now()
 	var currentBest ed25519.PublicKey
 	newKeys := make(chan keySet, threads)
 	for i := 0; i < threads; i++ {
@@ -36,7 +39,7 @@ func main() {
 		newKey := <-newKeys
 		if isBetter(currentBest, newKey.pub) || len(currentBest) == 0 {
 			currentBest = newKey.pub
-			fmt.Println("-----")
+			fmt.Println("-----", time.Since(start))
 			fmt.Println("Priv:", hex.EncodeToString(newKey.priv))
 			fmt.Println("Pub:", hex.EncodeToString(newKey.pub))
 			addr := address.AddrForKey(newKey.pub)

cmd/yggdrasil/main.go

@@ -48,8 +48,9 @@ func main() {
 	autoconf := flag.Bool("autoconf", false, "automatic mode (dynamic IP, peer with IPv6 neighbors)")
 	ver := flag.Bool("version", false, "prints the version of this build")
 	logto := flag.String("logto", "stdout", "file path to log to, \"syslog\" or \"stdout\"")
-	getaddr := flag.Bool("address", false, "returns the IPv6 address as derived from the supplied configuration")
-	getsnet := flag.Bool("subnet", false, "returns the IPv6 subnet as derived from the supplied configuration")
+	getaddr := flag.Bool("address", false, "use in combination with either -useconf or -useconffile, outputs your IPv6 address")
+	getsnet := flag.Bool("subnet", false, "use in combination with either -useconf or -useconffile, outputs your IPv6 subnet")
+	getpkey := flag.Bool("publickey", false, "use in combination with either -useconf or -useconffile, outputs your public key")
 	loglevel := flag.String("loglevel", "info", "loglevel to enable")
 	flag.Parse()
 
@@ -67,7 +68,7 @@ func main() {
 
 	case "syslog":
 		if syslogger, err := gsyslog.NewLogger(gsyslog.LOG_NOTICE, "DAEMON", version.BuildName()); err == nil {
-			logger = log.New(syslogger, "", log.Flags() &^ (log.Ldate | log.Ltime))
+			logger = log.New(syslogger, "", log.Flags()&^(log.Ldate|log.Ltime))
 		}
 
 	default:
@@ -113,6 +114,7 @@ func main() {
 		_ = f.Close()
 
 	case *genconf:
+		cfg.AdminListen = ""
 		var bs []byte
 		if *confjson {
 			bs, err = json.MarshalIndent(cfg, "", "  ")
@@ -154,7 +156,12 @@ func main() {
 		fmt.Println(ipnet.String())
 		return
 
+	case *getpkey:
+		fmt.Println(hex.EncodeToString(publicKey))
+		return
+
 	case *normaliseconf:
+		cfg.AdminListen = ""
 		var bs []byte
 		if *confjson {
 			bs, err = json.MarshalIndent(cfg, "", "  ")
@@ -205,6 +212,10 @@ func main() {
 		if n.core, err = core.New(cfg.Certificate, logger, options...); err != nil {
 			panic(err)
 		}
+		address, subnet := n.core.Address(), n.core.Subnet()
+		logger.Infof("Your public key is %s", hex.EncodeToString(n.core.PublicKey()))
+		logger.Infof("Your IPv6 address is %s", address.String())
+		logger.Infof("Your IPv6 subnet is %s", subnet.String())
 	}
 
 	// Setup the admin socket.
@@ -212,6 +223,9 @@ func main() {
 		options := []admin.SetupOption{
 			admin.ListenAddress(cfg.AdminListen),
 		}
+		if cfg.LogLookups {
+			options = append(options, admin.LogLookups{})
+		}
 		if n.admin, err = admin.New(n.core, logger, options...); err != nil {
 			panic(err)
 		}

cmd/yggdrasilctl/cmd_line_env.go

@@ -39,8 +39,8 @@ func (cmdLineEnv *CmdLineEnv) parseFlagsAndArgs() {
 		fmt.Println("  - ", os.Args[0], "list")
 		fmt.Println("  - ", os.Args[0], "getPeers")
 		fmt.Println("  - ", os.Args[0], "setTunTap name=auto mtu=1500 tap_mode=false")
-		fmt.Println("  - ", os.Args[0], "-endpoint=tcp://localhost:9001 getDHT")
-		fmt.Println("  - ", os.Args[0], "-endpoint=unix:///var/run/ygg.sock getDHT")
+		fmt.Println("  - ", os.Args[0], "-endpoint=tcp://localhost:9001 getPeers")
+		fmt.Println("  - ", os.Args[0], "-endpoint=unix:///var/run/ygg.sock getPeers")
 	}
 
 	server := flag.String("endpoint", cmdLineEnv.endpoint, "Admin socket endpoint")

contrib/deb/generate.sh

@@ -21,13 +21,16 @@ if [ $PKGBRANCH = "master" ]; then
   PKGREPLACES=yggdrasil-develop
 fi
 
-if [ $PKGARCH = "amd64" ]; then GOARCH=amd64 GOOS=linux ./build
-elif [ $PKGARCH = "i386" ]; then GOARCH=386 GOOS=linux ./build
-elif [ $PKGARCH = "mipsel" ]; then GOARCH=mipsle GOOS=linux ./build
-elif [ $PKGARCH = "mips" ]; then GOARCH=mips64 GOOS=linux ./build
-elif [ $PKGARCH = "armhf" ]; then GOARCH=arm GOOS=linux GOARM=6 ./build
-elif [ $PKGARCH = "arm64" ]; then GOARCH=arm64 GOOS=linux ./build
-elif [ $PKGARCH = "armel" ]; then GOARCH=arm GOOS=linux GOARM=5 ./build
+GOLDFLAGS="-X github.com/yggdrasil-network/yggdrasil-go/src/config.defaultConfig=/etc/yggdrasil/yggdrasil.conf"
+GOLDFLAGS="${GOLDFLAGS} -X github.com/yggdrasil-network/yggdrasil-go/src/config.defaultAdminListen=unix:///var/run/yggdrasil/yggdrasil.sock"
+
+if [ $PKGARCH = "amd64" ]; then GOARCH=amd64 GOOS=linux ./build -l "${GOLDFLAGS}"
+elif [ $PKGARCH = "i386" ]; then GOARCH=386 GOOS=linux ./build -l "${GOLDFLAGS}"
+elif [ $PKGARCH = "mipsel" ]; then GOARCH=mipsle GOOS=linux ./build -l "${GOLDFLAGS}"
+elif [ $PKGARCH = "mips" ]; then GOARCH=mips64 GOOS=linux ./build -l "${GOLDFLAGS}"
+elif [ $PKGARCH = "armhf" ]; then GOARCH=arm GOOS=linux GOARM=6 ./build -l "${GOLDFLAGS}"
+elif [ $PKGARCH = "arm64" ]; then GOARCH=arm64 GOOS=linux ./build -l "${GOLDFLAGS}"
+elif [ $PKGARCH = "armel" ]; then GOARCH=arm GOOS=linux GOARM=5 ./build -l "${GOLDFLAGS}"
 else
   echo "Specify PKGARCH=amd64,i386,mips,mipsel,armhf,arm64,armel"
   exit 1
@@ -38,7 +41,7 @@ echo "Building $PKGFILE"
 mkdir -p /tmp/$PKGNAME/
 mkdir -p /tmp/$PKGNAME/debian/
 mkdir -p /tmp/$PKGNAME/usr/bin/
-mkdir -p /tmp/$PKGNAME/etc/systemd/system/
+mkdir -p /tmp/$PKGNAME/lib/systemd/system/
 
 cat > /tmp/$PKGNAME/debian/changelog << EOF
 Please see https://github.com/yggdrasil-network/yggdrasil-go/
@@ -68,35 +71,52 @@ EOF
 cat > /tmp/$PKGNAME/debian/install << EOF
 usr/bin/yggdrasil usr/bin
 usr/bin/yggdrasilctl usr/bin
-etc/systemd/system/*.service etc/systemd/system
+lib/systemd/system/*.service lib/systemd/system
 EOF
 cat > /tmp/$PKGNAME/debian/postinst << EOF
 #!/bin/sh
 
+systemctl daemon-reload
+
 if ! getent group yggdrasil 2>&1 > /dev/null; then
-  groupadd --system --force yggdrasil || echo "Failed to create group 'yggdrasil' - please create it manually and reinstall"
+  groupadd --system --force yggdrasil
 fi
 
-if [ -f /etc/yggdrasil.conf ];
+if [ ! -d /etc/yggdrasil ];
+then
+    mkdir -p /etc/yggdrasil
+    chown root:yggdrasil /etc/yggdrasil
+    chmod 750 /etc/yggdrasil
+fi
+
+if [ ! -f /etc/yggdrasil/yggdrasil.conf ];
+then
+    test -f /etc/yggdrasil.conf && mv /etc/yggdrasil.conf /etc/yggdrasil/yggdrasil.conf
+fi
+
+if [ -f /etc/yggdrasil/yggdrasil.conf ];
 then
   mkdir -p /var/backups
   echo "Backing up configuration file to /var/backups/yggdrasil.conf.`date +%Y%m%d`"
-  cp /etc/yggdrasil.conf /var/backups/yggdrasil.conf.`date +%Y%m%d`
-  echo "Normalising and updating /etc/yggdrasil.conf"
-  /usr/bin/yggdrasil -useconf -normaliseconf < /var/backups/yggdrasil.conf.`date +%Y%m%d` > /etc/yggdrasil.conf
-  chgrp yggdrasil /etc/yggdrasil.conf
+  cp /etc/yggdrasil/yggdrasil.conf /var/backups/yggdrasil.conf.`date +%Y%m%d`
 
-  if command -v systemctl >/dev/null; then
-    systemctl daemon-reload >/dev/null || true
-    systemctl enable yggdrasil || true
-    systemctl start yggdrasil || true
-  fi
+  echo "Normalising and updating /etc/yggdrasil/yggdrasil.conf"
+  /usr/bin/yggdrasil -useconf -normaliseconf < /var/backups/yggdrasil.conf.`date +%Y%m%d` > /etc/yggdrasil/yggdrasil.conf
+  
+  chown root:yggdrasil /etc/yggdrasil/yggdrasil.conf
+  chmod 640 /etc/yggdrasil/yggdrasil.conf
 else
-  echo "Generating initial configuration file /etc/yggdrasil.conf"
-  echo "Please familiarise yourself with this file before starting Yggdrasil"
-  sh -c 'umask 0027 && /usr/bin/yggdrasil -genconf > /etc/yggdrasil.conf'
-  chgrp yggdrasil /etc/yggdrasil.conf
+  echo "Generating initial configuration file /etc/yggdrasil/yggdrasil.conf"
+  /usr/bin/yggdrasil -genconf > /etc/yggdrasil/yggdrasil.conf
+
+  chown root:yggdrasil /etc/yggdrasil/yggdrasil.conf
+  chmod 640 /etc/yggdrasil/yggdrasil.conf
 fi
+
+systemctl enable yggdrasil
+systemctl restart yggdrasil
+
+exit 0
 EOF
 cat > /tmp/$PKGNAME/debian/prerm << EOF
 #!/bin/sh
@@ -110,13 +130,14 @@ EOF
 
 cp yggdrasil /tmp/$PKGNAME/usr/bin/
 cp yggdrasilctl /tmp/$PKGNAME/usr/bin/
-cp contrib/systemd/*.service /tmp/$PKGNAME/etc/systemd/system/
+cp contrib/systemd/yggdrasil-default-config.service.debian /tmp/$PKGNAME/lib/systemd/system/yggdrasil-default-config.service
+cp contrib/systemd/yggdrasil.service.debian /tmp/$PKGNAME/lib/systemd/system/yggdrasil.service
 
-tar -czvf /tmp/$PKGNAME/data.tar.gz -C /tmp/$PKGNAME/ \
+tar --no-xattrs -czvf /tmp/$PKGNAME/data.tar.gz -C /tmp/$PKGNAME/ \
   usr/bin/yggdrasil usr/bin/yggdrasilctl \
-  etc/systemd/system/yggdrasil.service \
-  etc/systemd/system/yggdrasil-default-config.service
-tar -czvf /tmp/$PKGNAME/control.tar.gz -C /tmp/$PKGNAME/debian .
+  lib/systemd/system/yggdrasil.service \
+  lib/systemd/system/yggdrasil-default-config.service
+tar --no-xattrs -czvf /tmp/$PKGNAME/control.tar.gz -C /tmp/$PKGNAME/debian .
 echo 2.0 > /tmp/$PKGNAME/debian-binary
 
 ar -r $PKGFILE \

contrib/mobile/mobile.go

@@ -48,6 +48,7 @@ func (m *Yggdrasil) StartJSON(configjson []byte) error {
 	logger.EnableLevel("error")
 	logger.EnableLevel("warn")
 	logger.EnableLevel("info")
+	m.logger = logger
 	m.config = config.GenerateConfig()
 	if err := m.config.UnmarshalHJSON(configjson); err != nil {
 		return err
@@ -70,16 +71,24 @@ func (m *Yggdrasil) StartJSON(configjson []byte) error {
 			}
 			options = append(options, core.AllowedPublicKey(k[:]))
 		}
+		for _, lAddr := range m.config.Listen {
+			options = append(options, core.ListenAddress(lAddr))
+		}
 		var err error
 		m.core, err = core.New(m.config.Certificate, logger, options...)
 		if err != nil {
 			panic(err)
 		}
+		address, subnet := m.core.Address(), m.core.Subnet()
+		logger.Infof("Your public key is %s", hex.EncodeToString(m.core.PublicKey()))
+		logger.Infof("Your IPv6 address is %s", address.String())
+		logger.Infof("Your IPv6 subnet is %s", subnet.String())
 	}
 
 	// Setup the multicast module.
 	if len(m.config.MulticastInterfaces) > 0 {
 		var err error
+		logger.Infof("Initializing multicast %s", "")
 		options := []multicast.SetupOption{}
 		for _, intf := range m.config.MulticastInterfaces {
 			options = append(options, multicast.MulticastInterface{
@@ -91,9 +100,10 @@ func (m *Yggdrasil) StartJSON(configjson []byte) error {
 				Password: intf.Password,
 			})
 		}
+		logger.Infof("Starting multicast %s", "")
 		m.multicast, err = multicast.New(m.core, m.logger, options...)
 		if err != nil {
-			m.logger.Errorln("An error occurred starting multicast:", err)
+			logger.Errorln("An error occurred starting multicast:", err)
 		}
 	}
 
@@ -152,15 +162,20 @@ func (m *Yggdrasil) RecvBuffer(buf []byte) (int, error) {
 func (m *Yggdrasil) Stop() error {
 	logger := log.New(m.log, "", 0)
 	logger.EnableLevel("info")
-	logger.Infof("Stop the mobile Yggdrasil instance %s", "")
-	if err := m.multicast.Stop(); err != nil {
-		return err
+	logger.Infof("Stopping the mobile Yggdrasil instance %s", "")
+	if m.multicast != nil {
+		logger.Infof("Stopping multicast %s", "")
+		if err := m.multicast.Stop(); err != nil {
+			return err
+		}
 	}
+	logger.Infof("Stopping TUN device %s", "")
 	if m.tun != nil {
 		if err := m.tun.Stop(); err != nil {
 			return err
 		}
 	}
+	logger.Infof("Stopping Yggdrasil core %s", "")
 	m.core.Stop()
 	return nil
 }
@@ -208,8 +223,11 @@ func (m *Yggdrasil) GetPeersJSON() (result string) {
 		IP string
 	}{}
 	for _, v := range m.core.GetPeers() {
-		a := address.AddrForKey(v.Key)
-		ip := net.IP(a[:]).String()
+		var ip string
+		if v.Key != nil {
+			a := address.AddrForKey(v.Key)
+			ip = net.IP(a[:]).String()
+		}
 		peers = append(peers, struct {
 			core.PeerInfo
 			IP string

contrib/systemd/yggdrasil-default-config.service.debian

@@ -0,0 +1,13 @@
+[Unit]
+Description=Yggdrasil default config generator
+ConditionPathExists=|!/etc/yggdrasil/yggdrasil.conf
+ConditionFileNotEmpty=|!/etc/yggdrasil/yggdrasil.conf
+Wants=local-fs.target
+After=local-fs.target
+
+[Service]
+Type=oneshot
+Group=yggdrasil
+ExecStartPre=/usr/bin/mkdir -p /etc/yggdrasil
+ExecStart=/usr/bin/yggdrasil -genconf > /etc/yggdrasil/yggdrasil.conf
+ExecStartPost=/usr/bin/chmod -R 0640 /etc/yggdrasil

contrib/systemd/yggdrasil.service.debian

@@ -0,0 +1,25 @@
+[Unit]
+Description=Yggdrasil Network
+Wants=network-online.target
+Wants=yggdrasil-default-config.service
+After=network-online.target
+After=yggdrasil-default-config.service
+
+[Service]
+Group=yggdrasil
+ProtectHome=true
+ProtectSystem=strict
+NoNewPrivileges=true
+RuntimeDirectory=yggdrasil
+ReadWritePaths=/var/run/yggdrasil/ /run/yggdrasil/
+SyslogIdentifier=yggdrasil
+CapabilityBoundingSet=CAP_NET_ADMIN CAP_NET_BIND_SERVICE
+AmbientCapabilities=CAP_NET_ADMIN CAP_NET_BIND_SERVICE
+ExecStartPre=+-/sbin/modprobe tun
+ExecStart=/usr/bin/yggdrasil -useconffile /etc/yggdrasil/yggdrasil.conf
+ExecReload=/bin/kill -HUP $MAINPID
+Restart=always
+TimeoutStopSec=5
+
+[Install]
+WantedBy=multi-user.target

go.mod

@@ -3,7 +3,7 @@ module github.com/yggdrasil-network/yggdrasil-go
 go 1.20
 
 require (
-	github.com/Arceliar/ironwood v0.0.0-20230805085300-86206813435f
+	github.com/Arceliar/ironwood v0.0.0-20231104025256-ec84c695fc44
 	github.com/Arceliar/phony v0.0.0-20220903101357-530938a4b13d
 	github.com/cheggaaa/pb/v3 v3.1.4
 	github.com/gologme/log v1.3.0

go.sum

@@ -1,5 +1,5 @@
-github.com/Arceliar/ironwood v0.0.0-20230805085300-86206813435f h1:Fz0zG7ZyQQqk+ROnmHuGrIZO250Lx/YHmp9o48XE+Vw=
-github.com/Arceliar/ironwood v0.0.0-20230805085300-86206813435f/go.mod h1:5x7fWW0mshe9WQ1lvSMmmHBYC3BeHH9gpwW5tz7cbfw=
+github.com/Arceliar/ironwood v0.0.0-20231104025256-ec84c695fc44 h1:u328GAZGtL0W4oFWQs4YWHZT215LL6Lw9aYJxx76UVs=
+github.com/Arceliar/ironwood v0.0.0-20231104025256-ec84c695fc44/go.mod h1:5x7fWW0mshe9WQ1lvSMmmHBYC3BeHH9gpwW5tz7cbfw=
 github.com/Arceliar/phony v0.0.0-20220903101357-530938a4b13d h1:UK9fsWbWqwIQkMCz1CP+v5pGbsGoWAw6g4AyvMpm1EM=
 github.com/Arceliar/phony v0.0.0-20220903101357-530938a4b13d/go.mod h1:BCnxhRf47C/dy/e/D2pmB8NkB3dQVIrkD98b220rx5Q=
 github.com/VividCortex/ewma v1.2.0 h1:f58SaIzcDXrSy3kWaHNvuJgJ3Nmz59Zji6XoJR/q1ow=

src/admin/options.go

@@ -1,9 +1,24 @@
 package admin
 
+import (
+	"crypto/ed25519"
+	"encoding/hex"
+	"encoding/json"
+	"net"
+	"sync"
+	"time"
+
+	"github.com/Arceliar/ironwood/network"
+
+	"github.com/yggdrasil-network/yggdrasil-go/src/address"
+)
+
 func (c *AdminSocket) _applyOption(opt SetupOption) {
 	switch v := opt.(type) {
 	case ListenAddress:
 		c.config.listenaddr = v
+	case LogLookups:
+		c.logLookups()
 	}
 }
 
@@ -14,3 +29,51 @@ type SetupOption interface {
 type ListenAddress string
 
 func (a ListenAddress) isSetupOption() {}
+
+type LogLookups struct{}
+
+func (l LogLookups) isSetupOption() {}
+
+func (a *AdminSocket) logLookups() {
+	type resi struct {
+		Address string   `json:"addr"`
+		Key     string   `json:"key"`
+		Path    []uint64 `json:"path"`
+		Time    int64    `json:"time"`
+	}
+	type res struct {
+		Infos []resi `json:"infos"`
+	}
+	type info struct {
+		path []uint64
+		time time.Time
+	}
+	type edk [ed25519.PublicKeySize]byte
+	infos := make(map[edk]info)
+	var m sync.Mutex
+	a.core.PacketConn.PacketConn.Debug.SetDebugLookupLogger(func(l network.DebugLookupInfo) {
+		var k edk
+		copy(k[:], l.Key[:])
+		m.Lock()
+		infos[k] = info{path: l.Path, time: time.Now()}
+		m.Unlock()
+	})
+	_ = a.AddHandler(
+		"lookups", "Dump a record of lookups received in the past hour", []string{},
+		func(in json.RawMessage) (interface{}, error) {
+			m.Lock()
+			rs := make([]resi, 0, len(infos))
+			for k, v := range infos {
+				if time.Since(v.time) > 24*time.Hour {
+					// TODO? automatic cleanup, so we don't need to call lookups periodically to prevent leaks
+					delete(infos, k)
+				}
+				a := address.AddrForKey(ed25519.PublicKey(k[:]))
+				addr := net.IP(a[:]).String()
+				rs = append(rs, resi{Address: addr, Key: hex.EncodeToString(k[:]), Path: v.path, Time: v.time.Unix()})
+			}
+			m.Unlock()
+			return &res{Infos: rs}, nil
+		},
+	)
+}

src/admin/removepeer.go

@@ -1,5 +1,10 @@
 package admin
 
+import (
+	"fmt"
+	"net/url"
+)
+
 type RemovePeerRequest struct {
 	Uri   string `json:"uri"`
 	Sintf string `json:"interface,omitempty"`
@@ -8,5 +13,9 @@ type RemovePeerRequest struct {
 type RemovePeerResponse struct{}
 
 func (a *AdminSocket) removePeerHandler(req *RemovePeerRequest, res *RemovePeerResponse) error {
-	return a.core.RemovePeer(req.Uri, req.Sintf)
+	u, err := url.Parse(req.Uri)
+	if err != nil {
+		return fmt.Errorf("unable to parse peering URI: %w", err)
+	}
+	return a.core.RemovePeer(u, req.Sintf)
 }

src/config/config.go

@@ -46,13 +46,14 @@ type NodeConfig struct {
 	Peers               []string                   `comment:"List of connection strings for outbound peer connections in URI format,\ne.g. tls://a.b.c.d:e or socks://a.b.c.d:e/f.g.h.i:j. These connections\nwill obey the operating system routing table, therefore you should\nuse this section when you may connect via different interfaces."`
 	InterfacePeers      map[string][]string        `comment:"List of connection strings for outbound peer connections in URI format,\narranged by source interface, e.g. { \"eth0\": [ \"tls://a.b.c.d:e\" ] }.\nNote that SOCKS peerings will NOT be affected by this option and should\ngo in the \"Peers\" section instead."`
 	Listen              []string                   `comment:"Listen addresses for incoming connections. You will need to add\nlisteners in order to accept incoming peerings from non-local nodes.\nMulticast peer discovery will work regardless of any listeners set\nhere. Each listener should be specified in URI format as above, e.g.\ntls://0.0.0.0:0 or tls://[::]:0 to listen on all interfaces."`
-	AdminListen         string                     `comment:"Listen address for admin connections. Default is to listen for local\nconnections either on TCP/9001 or a UNIX socket depending on your\nplatform. Use this value for yggdrasilctl -endpoint=X. To disable\nthe admin socket, use the value \"none\" instead."`
+	AdminListen         string                     `json:",omitempty" comment:"Listen address for admin connections. Default is to listen for local\nconnections either on TCP/9001 or a UNIX socket depending on your\nplatform. Use this value for yggdrasilctl -endpoint=X. To disable\nthe admin socket, use the value \"none\" instead."`
 	MulticastInterfaces []MulticastInterfaceConfig `comment:"Configuration for which interfaces multicast peer discovery should be\nenabled on. Each entry in the list should be a json object which may\ncontain Regex, Beacon, Listen, and Port. Regex is a regular expression\nwhich is matched against an interface name, and interfaces use the\nfirst configuration that they match gainst. Beacon configures whether\nor not the node should send link-local multicast beacons to advertise\ntheir presence, while listening for incoming connections on Port.\nListen controls whether or not the node listens for multicast beacons\nand opens outgoing connections."`
 	AllowedPublicKeys   []string                   `comment:"List of peer public keys to allow incoming peering connections\nfrom. If left empty/undefined then all connections will be allowed\nby default. This does not affect outgoing peerings, nor does it\naffect link-local peers discovered via multicast."`
 	IfName              string                     `comment:"Local network interface name for TUN adapter, or \"auto\" to select\nan interface automatically, or \"none\" to run without TUN."`
 	IfMTU               uint64                     `comment:"Maximum Transmission Unit (MTU) size for your local TUN interface.\nDefault is the largest supported size for your platform. The lowest\npossible value is 1280."`
 	NodeInfoPrivacy     bool                       `comment:"By default, nodeinfo contains some defaults including the platform,\narchitecture and Yggdrasil version. These can help when surveying\nthe network and diagnosing network routing problems. Enabling\nnodeinfo privacy prevents this, so that only items specified in\n\"NodeInfo\" are sent back if specified."`
 	NodeInfo            map[string]interface{}     `comment:"Optional node info. This must be a { \"key\": \"value\", ... } map\nor set as null. This is entirely optional but, if set, is visible\nto the whole network on request."`
+	LogLookups          bool                       `json:",omitempty"`
 }
 
 type MulticastInterfaceConfig struct {

src/core/api.go

@@ -3,7 +3,6 @@ package core
 import (
 	"crypto/ed25519"
 	"encoding/json"
-	"fmt"
 	"net"
 	"net/url"
 	"sync/atomic"
@@ -192,28 +191,8 @@ func (c *Core) AddPeer(u *url.URL, sintf string) error {
 
 // RemovePeer removes a peer. The peer should be specified in URI format, see AddPeer.
 // The peer is not disconnected immediately.
-func (c *Core) RemovePeer(uri string, sourceInterface string) error {
-	return fmt.Errorf("not implemented yet")
-	/*
-		var err error
-		phony.Block(c, func() {
-			peer := Peer{uri, sourceInterface}
-			linkInfo, ok := c.config._peers[peer]
-			if !ok {
-				err = fmt.Errorf("peer not configured")
-				return
-			}
-			if ok && linkInfo != nil {
-				c.links.Act(nil, func() {
-					if link := c.links._links[*linkInfo]; link != nil {
-						_ = link.conn.Close()
-					}
-				})
-			}
-			delete(c.config._peers, peer)
-		})
-		return err
-	*/
+func (c *Core) RemovePeer(u *url.URL, sintf string) error {
+	return c.links.remove(u, sintf, linkTypePersistent)
 }
 
 // CallPeer calls a peer once. This should be specified in the peer URI format,

src/core/core.go

@@ -4,7 +4,6 @@ import (
 	"context"
 	"crypto/ed25519"
 	"crypto/tls"
-	"encoding/hex"
 	"fmt"
 	"io"
 	"net"
@@ -104,10 +103,6 @@ func New(cert *tls.Certificate, logger Logger, opts ...SetupOption) (*Core, erro
 	); err != nil {
 		return nil, fmt.Errorf("error creating encryption: %w", err)
 	}
-	address, subnet := c.Address(), c.Subnet()
-	c.log.Infof("Your public key is %s", hex.EncodeToString(c.public))
-	c.log.Infof("Your IPv6 address is %s", address.String())
-	c.log.Infof("Your IPv6 subnet is %s", subnet.String())
 	c.proto.init(c)
 	if err := c.links.init(c); err != nil {
 		return nil, fmt.Errorf("error initialising links: %w", err)
@@ -140,7 +135,14 @@ func New(cert *tls.Certificate, logger Logger, opts ...SetupOption) (*Core, erro
 }
 
 func (c *Core) RetryPeersNow() {
-	// TODO: figure out a way to retrigger peer connections.
+	phony.Block(&c.links, func() {
+		for _, l := range c.links._links {
+			select {
+			case l.kick <- struct{}{}:
+			default:
+			}
+		}
+	})
 }
 
 // Stop shuts down the Yggdrasil node.

src/core/debug.go

@@ -1,6 +1,3 @@
-//go:build debug
-// +build debug
-
 package core
 
 import (
@@ -8,28 +5,13 @@ import (
 	"net/http"
 	_ "net/http/pprof"
 	"os"
-	"runtime"
-
-	"github.com/gologme/log"
 )
 
-// Start the profiler in debug builds, if the required environment variable is set.
+// Start the profiler if the required environment variable is set.
 func init() {
 	envVarName := "PPROFLISTEN"
-	hostPort := os.Getenv(envVarName)
-	switch {
-	case hostPort == "":
-		fmt.Fprintf(os.Stderr, "DEBUG: %s not set, profiler not started.\n", envVarName)
-	default:
+	if hostPort := os.Getenv(envVarName); hostPort != "" {
 		fmt.Fprintf(os.Stderr, "DEBUG: Starting pprof on %s\n", hostPort)
-		go func() { fmt.Println(http.ListenAndServe(hostPort, nil)) }()
+		go fmt.Println(http.ListenAndServe(hostPort, nil))
 	}
 }
-
-// Starts the function profiler. This is only supported when built with
-// '-tags build'.
-func StartProfiler(log *log.Logger) error {
-	runtime.SetBlockProfileRate(1)
-	go func() { log.Println(http.ListenAndServe("localhost:6060", nil)) }()
-	return nil
-}

src/core/link.go

@@ -53,9 +53,11 @@ type linkInfo struct {
 
 // link tracks the state of a connection, either persistent or non-persistent
 type link struct {
-	kick      chan struct{} // Attempt to reconnect now, if backing off
-	linkType  linkType      // Type of link, i.e. outbound/inbound, persistent/ephemeral
-	linkProto string        // Protocol carrier of link, e.g. TCP, AWDL
+	ctx       context.Context    // Connection context
+	cancel    context.CancelFunc // Stop future redial attempts (when peer removed)
+	kick      chan struct{}      // Attempt to reconnect now, if backing off
+	linkType  linkType           // Type of link, i.e. outbound/inbound, persistent/ephemeral
+	linkProto string             // Protocol carrier of link, e.g. TCP, AWDL
 	// The remaining fields can only be modified safely from within the links actor
 	_conn    *linkConn // Connected link, if any, nil if not connected
 	_err     error     // Last error on the connection, if any
@@ -129,6 +131,7 @@ type linkError string
 func (e linkError) Error() string { return string(e) }
 
 const ErrLinkAlreadyConfigured = linkError("peer is already configured")
+const ErrLinkNotConfigured = linkError("peer is not configured")
 const ErrLinkPriorityInvalid = linkError("priority value is invalid")
 const ErrLinkPinnedKeyInvalid = linkError("pinned public key is invalid")
 const ErrLinkPasswordInvalid = linkError("password is invalid")
@@ -176,6 +179,22 @@ func (l *links) add(u *url.URL, sintf string, linkType linkType) error {
 			}
 			options.password = []byte(p)
 		}
+		// SNI headers must contain hostnames and not IP addresses, so we must make sure
+		// that we do not populate the SNI with an IP literal. We do this by splitting
+		// the host-port combo from the query option and then seeing if it parses to an
+		// IP address successfully or not.
+		if sni := u.Query().Get("sni"); sni != "" {
+			if net.ParseIP(sni) == nil {
+				options.tlsSNI = sni
+			}
+		}
+		// If the SNI is not configured still because the above failed then we'll try
+		// again but this time we'll use the host part of the peering URI instead.
+		if options.tlsSNI == "" {
+			if host, _, err := net.SplitHostPort(u.Host); err == nil && net.ParseIP(host) == nil {
+				options.tlsSNI = host
+			}
+		}
 
 		// If we think we're already connected to this peer, load up
 		// the existing peer state. Try to kick the peer if possible,
@@ -199,6 +218,7 @@ func (l *links) add(u *url.URL, sintf string, linkType linkType) error {
 			linkProto: strings.ToUpper(u.Scheme),
 			kick:      make(chan struct{}),
 		}
+		state.ctx, state.cancel = context.WithCancel(l.core.ctx)
 
 		// Store the state of the link so that it can be queried later.
 		l._links[info] = state
@@ -218,12 +238,14 @@ func (l *links) add(u *url.URL, sintf string, linkType linkType) error {
 			backoff++
 			duration := time.Second * time.Duration(math.Exp2(float64(backoff)))
 			select {
-			case <-time.After(duration):
-				return true
 			case <-state.kick:
 				return true
+			case <-state.ctx.Done():
+				return false
 			case <-l.core.ctx.Done():
 				return false
+			case <-time.After(duration):
+				return true
 			}
 		}
 
@@ -232,20 +254,29 @@ func (l *links) add(u *url.URL, sintf string, linkType linkType) error {
 		// then the loop will run endlessly, using backoffs as needed.
 		// Otherwise the loop will end, cleaning up the link entry.
 		go func() {
-			defer func() {
-				phony.Block(l, func() {
-					if l._links[info] == state {
-						delete(l._links, info)
-					}
-				})
-			}()
+			defer phony.Block(l, func() {
+				if l._links[info] == state {
+					delete(l._links, info)
+				}
+			})
 
 			// This loop will run each and every time we want to attempt
 			// a connection to this peer.
 			// TODO get rid of this loop, this is *exactly* what time.AfterFunc is for, we should just send a signal to the links actor to kick off a goroutine as needed
 			for {
-				conn, err := l.connect(u, info, options)
-				if err != nil {
+				select {
+				case <-state.ctx.Done():
+					// The peering context has been cancelled, so don't try
+					// to dial again.
+					return
+				default:
+				}
+
+				conn, err := l.connect(state.ctx, u, info, options)
+				if err != nil || conn == nil {
+					if err == nil && conn == nil {
+						l.core.log.Warnf("Link %q reached inconsistent error state", u.String())
+					}
 					if linkType == linkTypePersistent {
 						// If the link is a persistent configured peering,
 						// store information about the connection error so
@@ -319,13 +350,39 @@ func (l *links) add(u *url.URL, sintf string, linkType linkType) error {
 					}
 					return
 				}
-				break
 			}
 		}()
 	})
 	return retErr
 }
 
+func (l *links) remove(u *url.URL, sintf string, linkType linkType) error {
+	var retErr error
+	phony.Block(l, func() {
+		// Generate the link info and see whether we think we already
+		// have an open peering to this peer.
+		lu := urlForLinkInfo(*u)
+		info := linkInfo{
+			uri:   lu.String(),
+			sintf: sintf,
+		}
+
+		// If this peer is already configured then we will close the
+		// connection and stop it from retrying.
+		state, ok := l._links[info]
+		if ok && state != nil {
+			state.cancel()
+			if conn := state._conn; conn != nil {
+				retErr = conn.Close()
+			}
+			return
+		}
+
+		retErr = ErrLinkNotConfigured
+	})
+	return retErr
+}
+
 func (l *links) listen(u *url.URL, sintf string) (*Listener, error) {
 	ctx, cancel := context.WithCancel(l.core.ctx)
 	var protocol linkProtocol
@@ -374,7 +431,7 @@ func (l *links) listen(u *url.URL, sintf string) (*Listener, error) {
 		for {
 			conn, err := listener.Accept()
 			if err != nil {
-				continue
+				return
 			}
 			go func(conn net.Conn) {
 				defer conn.Close()
@@ -453,30 +510,14 @@ func (l *links) listen(u *url.URL, sintf string) (*Listener, error) {
 	return li, nil
 }
 
-func (l *links) connect(u *url.URL, info linkInfo, options linkOptions) (net.Conn, error) {
+func (l *links) connect(ctx context.Context, u *url.URL, info linkInfo, options linkOptions) (net.Conn, error) {
 	var dialer linkProtocol
 	switch strings.ToLower(u.Scheme) {
 	case "tcp":
 		dialer = l.tcp
 	case "tls":
-		// SNI headers must contain hostnames and not IP addresses, so we must make sure
-		// that we do not populate the SNI with an IP literal. We do this by splitting
-		// the host-port combo from the query option and then seeing if it parses to an
-		// IP address successfully or not.
-		if sni := u.Query().Get("sni"); sni != "" {
-			if net.ParseIP(sni) == nil {
-				options.tlsSNI = sni
-			}
-		}
-		// If the SNI is not configured still because the above failed then we'll try
-		// again but this time we'll use the host part of the peering URI instead.
-		if options.tlsSNI == "" {
-			if host, _, err := net.SplitHostPort(u.Host); err == nil && net.ParseIP(host) == nil {
-				options.tlsSNI = host
-			}
-		}
 		dialer = l.tls
-	case "socks":
+	case "socks", "sockstls":
 		dialer = l.socks
 	case "unix":
 		dialer = l.unix
@@ -485,7 +526,7 @@ func (l *links) connect(u *url.URL, info linkInfo, options linkOptions) (net.Con
 	default:
 		return nil, ErrLinkUnrecognisedSchema
 	}
-	return dialer.dial(l.core.ctx, u, info, options)
+	return dialer.dial(ctx, u, info, options)
 }
 
 func (l *links) handler(linkType linkType, options linkOptions, conn net.Conn) error {
@@ -508,8 +549,9 @@ func (l *links) handler(linkType linkType, options linkOptions, conn net.Conn) e
 	}
 	meta = version_metadata{}
 	base := version_getBaseMetadata()
-	if !meta.decode(conn, options.password) {
-		return conn.Close()
+	if err := meta.decode(conn, options.password); err != nil {
+		_ = conn.Close()
+		return err
 	}
 	if !meta.check() {
 		return fmt.Errorf("remote node incompatible version (local %s, remote %s)",

src/core/link_socks.go

@@ -2,6 +2,7 @@ package core
 
 import (
 	"context"
+	"crypto/tls"
 	"fmt"
 	"net"
 	"net/url"
@@ -34,7 +35,16 @@ func (l *linkSOCKS) dial(_ context.Context, url *url.URL, info linkInfo, options
 		return nil, fmt.Errorf("failed to configure proxy")
 	}
 	pathtokens := strings.Split(strings.Trim(url.Path, "/"), "/")
-	return dialer.Dial("tcp", pathtokens[0])
+	conn, err := dialer.Dial("tcp", pathtokens[0])
+	if err != nil {
+		return nil, fmt.Errorf("failed to dial: %w", err)
+	}
+	if url.Scheme == "sockstls" {
+		tlsconfig := l.tls.config.Clone()
+		tlsconfig.ServerName = options.tlsSNI
+		conn = tls.Client(conn, tlsconfig)
+	}
+	return conn, nil
 }
 
 func (l *linkSOCKS) listen(ctx context.Context, url *url.URL, _ string) (net.Listener, error) {

src/core/options.go

@@ -13,7 +13,15 @@ func (c *Core) _applyOption(opt SetupOption) (err error) {
 		if err != nil {
 			return fmt.Errorf("unable to parse peering URI: %w", err)
 		}
-		return c.links.add(u, v.SourceInterface, linkTypePersistent)
+		err = c.links.add(u, v.SourceInterface, linkTypePersistent)
+		switch err {
+		case ErrLinkAlreadyConfigured:
+			// Don't return this error, otherwise we'll panic at startup
+			// if there are multiple of the same peer configured
+			return nil
+		default:
+			return err
+		}
 	case ListenAddress:
 		c.config._listeners[v] = struct{}{}
 	case NodeInfo:

src/core/options_test.go

@@ -0,0 +1,41 @@
+package core
+
+import (
+	"net/url"
+	"testing"
+
+	"github.com/yggdrasil-network/yggdrasil-go/src/config"
+)
+
+// Tests that duplicate peers in the configuration file
+// won't cause an error when the node starts. Otherwise
+// we can panic unnecessarily.
+func TestDuplicatePeerAtStartup(t *testing.T) {
+	cfg := config.GenerateConfig()
+	for i := 0; i < 5; i++ {
+		cfg.Peers = append(cfg.Peers, "tcp://1.2.3.4:4321")
+	}
+	if _, err := New(cfg.Certificate, nil); err != nil {
+		t.Fatal(err)
+	}
+}
+
+// Tests that duplicate peers given to us through the
+// API will still error as expected, even if they didn't
+// at startup. We expect to notify the user through the
+// admin socket if they try to add a peer that is already
+// configured.
+func TestDuplicatePeerFromAPI(t *testing.T) {
+	cfg := config.GenerateConfig()
+	c, err := New(cfg.Certificate, nil)
+	if err != nil {
+		t.Fatal(err)
+	}
+	u, _ := url.Parse("tcp://1.2.3.4:4321")
+	if err := c.AddPeer(u, ""); err != nil {
+		t.Fatalf("Adding peer failed on first attempt: %s", err)
+	}
+	if err := c.AddPeer(u, ""); err == nil {
+		t.Fatalf("Adding peer should have failed on second attempt")
+	}
+}

src/core/tls.go

@@ -8,7 +8,7 @@ import (
 func (c *Core) generateTLSConfig(cert *tls.Certificate) (*tls.Config, error) {
 	config := &tls.Config{
 		Certificates: []tls.Certificate{*cert},
-		ClientAuth:   tls.RequireAnyClientCert,
+		ClientAuth:   tls.NoClientCert,
 		GetClientCertificate: func(cri *tls.CertificateRequestInfo) (*tls.Certificate, error) {
 			return cert, nil
 		},

src/core/version.go

@@ -87,22 +87,22 @@ func (m *version_metadata) encode(privateKey ed25519.PrivateKey, password []byte
 }
 
 // Decodes version metadata from its wire format into the struct.
-func (m *version_metadata) decode(r io.Reader, password []byte) bool {
+func (m *version_metadata) decode(r io.Reader, password []byte) error {
 	bh := [6]byte{}
 	if _, err := io.ReadFull(r, bh[:]); err != nil {
-		return false
+		return err
 	}
 	meta := [4]byte{'m', 'e', 't', 'a'}
 	if !bytes.Equal(bh[:4], meta[:]) {
-		return false
+		return fmt.Errorf("invalid handshake preamble")
 	}
-	bs := make([]byte, binary.BigEndian.Uint16(bh[4:6]))
+	hl := binary.BigEndian.Uint16(bh[4:6])
+	if hl < ed25519.SignatureSize {
+		return fmt.Errorf("invalid handshake length")
+	}
+	bs := make([]byte, hl)
 	if _, err := io.ReadFull(r, bs); err != nil {
-		return false
-	}
-
-	if len(bs) < ed25519.SignatureSize {
-		return false
+		return err
 	}
 	sig := bs[len(bs)-ed25519.SignatureSize:]
 	bs = bs[:len(bs)-ed25519.SignatureSize]
@@ -132,14 +132,17 @@ func (m *version_metadata) decode(r io.Reader, password []byte) bool {
 
 	hasher, err := blake2b.New512(password)
 	if err != nil {
-		return false
+		return fmt.Errorf("invalid password supplied")
 	}
 	n, err := hasher.Write(m.publicKey)
 	if err != nil || n != ed25519.PublicKeySize {
-		return false
+		return fmt.Errorf("failed to generate hash")
 	}
 	hash := hasher.Sum(nil)
-	return ed25519.Verify(m.publicKey, hash, sig)
+	if !ed25519.Verify(m.publicKey, hash, sig) {
+		return fmt.Errorf("password is incorrect")
+	}
+	return nil
 }
 
 // Checks that the "meta" bytes and the version numbers are the expected values.

src/core/version_test.go

@@ -34,7 +34,7 @@ func TestVersionPasswordAuth(t *testing.T) {
 		}
 
 		var decoded version_metadata
-		if allowed := decoded.decode(bytes.NewBuffer(encoded), tt.password2); allowed != tt.allowed {
+		if allowed := decoded.decode(bytes.NewBuffer(encoded), tt.password2) == nil; allowed != tt.allowed {
 			t.Fatalf("Permutation %q -> %q should have been %v but was %v", tt.password1, tt.password2, tt.allowed, allowed)
 		}
 	}
@@ -67,8 +67,8 @@ func TestVersionRoundtrip(t *testing.T) {
 			}
 			encoded := bytes.NewBuffer(meta)
 			decoded := &version_metadata{}
-			if !decoded.decode(encoded, password) {
-				t.Fatalf("failed to decode")
+			if err := decoded.decode(encoded, password); err != nil {
+				t.Fatalf("failed to decode: %s", err)
 			}
 			if !reflect.DeepEqual(test, decoded) {
 				t.Fatalf("round-trip failed\nwant: %+v\n got: %+v", test, decoded)

src/tun/tun.go

@@ -44,7 +44,7 @@ type TunAdapter struct {
 	isOpen      bool
 	isEnabled   bool // Used by the writer to drop sessionTraffic if not enabled
 	config      struct {
-    fd   int32
+		fd   int32
 		name InterfaceName
 		mtu  InterfaceMTU
 	}
@@ -116,7 +116,10 @@ func (tun *TunAdapter) _start() error {
 	tun.addr = tun.rwc.Address()
 	tun.subnet = tun.rwc.Subnet()
 	prefix := address.GetPrefix()
-	addr := fmt.Sprintf("%s/%d", net.IP(tun.addr[:]).String(), 8*len(prefix[:])-1)
+	var addr string
+	if tun.addr.IsValid() {
+		addr = fmt.Sprintf("%s/%d", net.IP(tun.addr[:]).String(), 8*len(prefix[:])-1)
+	}
 	if tun.config.name == "none" || tun.config.name == "dummy" {
 		tun.log.Debugln("Not starting TUN as ifname is none or dummy")
 		tun.isEnabled = false

src/tun/tun_bsd.go

@@ -78,7 +78,7 @@ type in6_ifreq_lifetime struct {
 func (tun *TunAdapter) setup(ifname string, addr string, mtu uint64) error {
 	iface, err := wgtun.CreateTUN(ifname, int(mtu))
 	if err != nil {
-		panic(err)
+		return fmt.Errorf("failed to create TUN: %w", err)
 	}
 	tun.iface = iface
 	if mtu, err := iface.MTU(); err == nil {
@@ -86,7 +86,10 @@ func (tun *TunAdapter) setup(ifname string, addr string, mtu uint64) error {
 	} else {
 		tun.mtu = 0
 	}
-	return tun.setupAddress(addr)
+	if addr != "" {
+		return tun.setupAddress(addr)
+	}
+	return nil
 }
 
 // Configures the "utun" adapter from an existing file descriptor.

src/tun/tun_darwin.go

@@ -7,6 +7,7 @@ package tun
 
 import (
 	"encoding/binary"
+	"fmt"
 	"os"
 	"strconv"
 	"strings"
@@ -24,7 +25,7 @@ func (tun *TunAdapter) setup(ifname string, addr string, mtu uint64) error {
 	}
 	iface, err := wgtun.CreateTUN(ifname, int(mtu))
 	if err != nil {
-		panic(err)
+		return fmt.Errorf("failed to create TUN: %w", err)
 	}
 	tun.iface = iface
 	if m, err := iface.MTU(); err == nil {
@@ -32,24 +33,27 @@ func (tun *TunAdapter) setup(ifname string, addr string, mtu uint64) error {
 	} else {
 		tun.mtu = 0
 	}
-	return tun.setupAddress(addr)
+	if addr != "" {
+		return tun.setupAddress(addr)
+	}
+	return nil
 }
 
 // Configures the "utun" adapter from an existing file descriptor.
 func (tun *TunAdapter) setupFD(fd int32, addr string, mtu uint64) error {
 	dfd, err := unix.Dup(int(fd))
 	if err != nil {
-		return err
+		return fmt.Errorf("failed to duplicate FD: %w", err)
 	}
 	err = unix.SetNonblock(dfd, true)
 	if err != nil {
 		unix.Close(dfd)
-		return err
+		return fmt.Errorf("failed to set FD as non-blocking: %w", err)
 	}
 	iface, err := wgtun.CreateTUNFromFile(os.NewFile(uintptr(dfd), "/dev/tun"), 0)
 	if err != nil {
 		unix.Close(dfd)
-		return err
+		return fmt.Errorf("failed to create TUN from FD: %w", err)
 	}
 	tun.iface = iface
 	if m, err := iface.MTU(); err == nil {
@@ -108,7 +112,7 @@ func (tun *TunAdapter) setupAddress(addr string) error {
 
 	if fd, err = unix.Socket(unix.AF_INET6, unix.SOCK_DGRAM, 0); err != nil {
 		tun.log.Printf("Create AF_SYSTEM socket failed: %v.", err)
-		return err
+		return fmt.Errorf("failed to open AF_SYSTEM: %w", err)
 	}
 
 	var ar in6_aliasreq
@@ -146,13 +150,13 @@ func (tun *TunAdapter) setupAddress(addr string) error {
 	if _, _, errno := unix.Syscall(unix.SYS_IOCTL, uintptr(fd), uintptr(darwin_SIOCAIFADDR_IN6), uintptr(unsafe.Pointer(&ar))); errno != 0 { // nolint:staticcheck
 		err = errno
 		tun.log.Errorf("Error in darwin_SIOCAIFADDR_IN6: %v", errno)
-		return err
+		return fmt.Errorf("failed to call SIOCAIFADDR_IN6: %w", err)
 	}
 
 	if _, _, errno := unix.Syscall(unix.SYS_IOCTL, uintptr(fd), uintptr(unix.SIOCSIFMTU), uintptr(unsafe.Pointer(&ir))); errno != 0 { // nolint:staticcheck
 		err = errno
 		tun.log.Errorf("Error in SIOCSIFMTU: %v", errno)
-		return err
+		return fmt.Errorf("failed to call SIOCSIFMTU: %w", err)
 	}
 
 	return err

src/tun/tun_linux.go

@@ -19,7 +19,7 @@ func (tun *TunAdapter) setup(ifname string, addr string, mtu uint64) error {
 	}
 	iface, err := wgtun.CreateTUN(ifname, int(mtu))
 	if err != nil {
-		panic(err)
+		return fmt.Errorf("failed to create TUN: %w", err)
 	}
 	tun.iface = iface
 	if mtu, err := iface.MTU(); err == nil {
@@ -27,7 +27,10 @@ func (tun *TunAdapter) setup(ifname string, addr string, mtu uint64) error {
 	} else {
 		tun.mtu = 0
 	}
-	return tun.setupAddress(addr)
+	if addr != "" {
+		return tun.setupAddress(addr)
+	}
+	return nil
 }
 
 // Configures the "utun" adapter from an existing file descriptor.
@@ -42,20 +45,20 @@ func (tun *TunAdapter) setupFD(fd int32, addr string, mtu uint64) error {
 func (tun *TunAdapter) setupAddress(addr string) error {
 	nladdr, err := netlink.ParseAddr(addr)
 	if err != nil {
-		return err
+		return fmt.Errorf("couldn't parse address %q: %w", addr, err)
 	}
 	nlintf, err := netlink.LinkByName(tun.Name())
 	if err != nil {
-		return err
+		return fmt.Errorf("failed to find link by name: %w", err)
 	}
 	if err := netlink.AddrAdd(nlintf, nladdr); err != nil {
-		return err
+		return fmt.Errorf("failed to add address to link: %w", err)
 	}
 	if err := netlink.LinkSetMTU(nlintf, int(tun.mtu)); err != nil {
-		return err
+		return fmt.Errorf("failed to set link MTU: %w", err)
 	}
 	if err := netlink.LinkSetUp(nlintf); err != nil {
-		return err
+		return fmt.Errorf("failed to bring link up: %w", err)
 	}
 	// Friendly output
 	tun.log.Infof("Interface name: %s", tun.Name())

src/tun/tun_other.go

@@ -16,7 +16,7 @@ import (
 func (tun *TunAdapter) setup(ifname string, addr string, mtu uint64) error {
 	iface, err := wgtun.CreateTUN(ifname, mtu)
 	if err != nil {
-		panic(err)
+		return fmt.Errorf("failed to create TUN: %w", err)
 	}
 	tun.iface = iface
 	if mtu, err := iface.MTU(); err == nil {
@@ -24,7 +24,10 @@ func (tun *TunAdapter) setup(ifname string, addr string, mtu uint64) error {
 	} else {
 		tun.mtu = 0
 	}
-	return tun.setupAddress(addr)
+	if addr != "" {
+		return tun.setupAddress(addr)
+	}
+	return nil
 }
 
 // Configures the "utun" adapter from an existing file descriptor.

src/tun/tun_windows.go

@@ -35,9 +35,11 @@ func (tun *TunAdapter) setup(ifname string, addr string, mtu uint64) error {
 			return err
 		}
 		tun.iface = iface
-		if err = tun.setupAddress(addr); err != nil {
-			tun.log.Errorln("Failed to set up TUN address:", err)
-			return err
+		if addr != "" {
+			if err = tun.setupAddress(addr); err != nil {
+				tun.log.Errorln("Failed to set up TUN address:", err)
+				return err
+			}
 		}
 		if err = tun.setupMTU(getSupportedMTU(mtu)); err != nil {
 			tun.log.Errorln("Failed to set up TUN MTU:", err)