Version 0.4.6

CHANGELOG.md

@@ -26,6 +26,25 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 - in case of vulnerabilities.
 -->
 
+## [0.4.6] - 2022-10-25
+
+### Added
+
+- Support for prioritising multiple peerings to the same node has been added, useful for nodes with multiple network interfaces
+  - The priority can be configured by specifying `?priority=X` in a `Peers` or `Listen` URI, or by specifying `Priority` within a `MulticastInterfaces` configuration entry
+  - Priorities are values between 0 and 254 (default is 0), lower numbers are prioritised and nodes will automatically negotiate the higher of the two values
+
+### Changed
+
+- On Linux, `SO_REUSEADDR` is now used on the multicast port instead of `SO_REUSEPORT`, which should allow processes running under different users to run simultaneously
+
+### Fixed
+
+- Adding peers using the `InterfacePeers` configuration option should now work correctly again
+- Multiple connections from the same remote IP address will no longer be incorrectly dropped
+- The admin socket will no longer incorrectly claim TCP connections as TLS
+- A panic that could occur when calling `GetPeers` while a peering link is being set up has been fixed
+
 ## [0.4.5] - 2022-10-15
 
 ### Added

cmd/yggdrasil/main.go

@@ -335,10 +335,11 @@ func run(args yggArgs, ctx context.Context) {
 		options := []multicast.SetupOption{}
 		for _, intf := range cfg.MulticastInterfaces {
 			options = append(options, multicast.MulticastInterface{
-				Regex:  regexp.MustCompile(intf.Regex),
+				Regex:    regexp.MustCompile(intf.Regex),
-				Beacon: intf.Beacon,
+				Beacon:   intf.Beacon,
-				Listen: intf.Listen,
+				Listen:   intf.Listen,
-				Port:   intf.Port,
+				Port:     intf.Port,
+				Priority: intf.Priority,
 			})
 		}
 		if n.multicast, err = multicast.New(n.core, logger, options...); err != nil {

cmd/yggdrasilctl/main.go

@@ -174,7 +174,7 @@ func run() int {
 		if err := json.Unmarshal(recv.Response, &resp); err != nil {
 			panic(err)
 		}
-		table.SetHeader([]string{"Port", "Public Key", "IP Address", "Uptime", "RX", "TX", "URI"})
+		table.SetHeader([]string{"Port", "Public Key", "IP Address", "Uptime", "RX", "TX", "Pr", "URI"})
 		for _, peer := range resp.Peers {
 			table.Append([]string{
 				fmt.Sprintf("%d", peer.Port),
@@ -183,6 +183,7 @@ func run() int {
 				(time.Duration(peer.Uptime) * time.Second).String(),
 				peer.RXBytes.String(),
 				peer.TXBytes.String(),
+				fmt.Sprintf("%d", peer.Priority),
 				peer.Remote,
 			})
 		}

contrib/mobile/mobile.go

@@ -83,10 +83,11 @@ func (m *Yggdrasil) StartJSON(configjson []byte) error {
 		options := []multicast.SetupOption{}
 		for _, intf := range m.config.MulticastInterfaces {
 			options = append(options, multicast.MulticastInterface{
-				Regex:  regexp.MustCompile(intf.Regex),
+				Regex:    regexp.MustCompile(intf.Regex),
-				Beacon: intf.Beacon,
+				Beacon:   intf.Beacon,
-				Listen: intf.Listen,
+				Listen:   intf.Listen,
-				Port:   intf.Port,
+				Port:     intf.Port,
+				Priority: intf.Priority,
 			})
 		}
 		m.multicast, err = multicast.New(m.core, logger, options...)

go.mod

@@ -3,7 +3,7 @@ module github.com/yggdrasil-network/yggdrasil-go
 go 1.17
 
 require (
-	github.com/Arceliar/ironwood v0.0.0-20220924160422-ed4b6d4750b6
+	github.com/Arceliar/ironwood v0.0.0-20221025225125-45b4281814c2
 	github.com/Arceliar/phony v0.0.0-20210209235338-dde1a8dca979
 	github.com/cheggaaa/pb/v3 v3.0.8
 	github.com/gologme/log v1.2.0

go.sum

@@ -1,5 +1,5 @@
-github.com/Arceliar/ironwood v0.0.0-20220924160422-ed4b6d4750b6 h1:iwL6nm2ibyuHXYimRNtFof7RJfe8JB+6CPDskV7K7gA=
+github.com/Arceliar/ironwood v0.0.0-20221025225125-45b4281814c2 h1:Usab30pNT2i/vZvpXcN9uOr5IO1RZPcUqoGH0DIAPnU=
-github.com/Arceliar/ironwood v0.0.0-20220924160422-ed4b6d4750b6/go.mod h1:RP72rucOFm5udrnEzTmIWLRVGQiV/fSUAQXJ0RST/nk=
+github.com/Arceliar/ironwood v0.0.0-20221025225125-45b4281814c2/go.mod h1:RP72rucOFm5udrnEzTmIWLRVGQiV/fSUAQXJ0RST/nk=
 github.com/Arceliar/phony v0.0.0-20210209235338-dde1a8dca979 h1:WndgpSW13S32VLQ3ugUxx2EnnWmgba1kCqPkd4Gk1yQ=
 github.com/Arceliar/phony v0.0.0-20210209235338-dde1a8dca979/go.mod h1:6Lkn+/zJilRMsKmbmG1RPoamiArC6HS73xbwRyp3UyI=
 github.com/BurntSushi/xgb v0.0.0-20160522181843-27f122750802/go.mod h1:IVnqGOEym/WlBOVXweHU+Q+/VP0lqqI8lqeDx9IjBqo=
@@ -17,8 +17,6 @@ github.com/hashicorp/go-syslog v1.0.0 h1:KaodqZuhUoZereWVIYmpUgZysurB1kBLX2j0MwM
 github.com/hashicorp/go-syslog v1.0.0/go.mod h1:qPfqrKkXGihmCqbJM2mZgkZGvKG1dFdvsLplgctolz4=
 github.com/hjson/hjson-go v3.1.0+incompatible h1:DY/9yE8ey8Zv22bY+mHV1uk2yRy0h8tKhZ77hEdi0Aw=
 github.com/hjson/hjson-go v3.1.0+incompatible/go.mod h1:qsetwF8NlsTsOTwZTApNlTCerV+b2GjYRRcIk4JMFio=
-github.com/kardianos/minwinsvc v1.0.0 h1:+JfAi8IBJna0jY2dJGZqi7o15z13JelFIklJCAENALA=
-github.com/kardianos/minwinsvc v1.0.0/go.mod h1:Bgd0oc+D0Qo3bBytmNtyRKVlp85dAloLKhfxanPFFRc=
 github.com/kardianos/minwinsvc v1.0.2 h1:JmZKFJQrmTGa/WiW+vkJXKmfzdjabuEW4Tirj5lLdR0=
 github.com/kardianos/minwinsvc v1.0.2/go.mod h1:LUZNYhNmxujx2tR7FbdxqYJ9XDDoCd3MQcl1o//FWl4=
 github.com/lxn/walk v0.0.0-20210112085537-c389da54e794/go.mod h1:E23UucZGqpuUANJooIbHWCufXvOcT6E7Stq81gU+CSQ=
@@ -50,7 +48,6 @@ golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACk
 golang.org/x/crypto v0.0.0-20190510104115-cbcb75029529/go.mod h1:yigFU9vqHzYiE8UmvKecakEJjdnWj3jj499lnFckfCI=
 golang.org/x/crypto v0.0.0-20191011191535-87dc89f01550/go.mod h1:yigFU9vqHzYiE8UmvKecakEJjdnWj3jj499lnFckfCI=
 golang.org/x/crypto v0.0.0-20210421170649-83a5a9bb288b/go.mod h1:T9bdIzuCu7OtxOm1hfPfRQxPLYneinmdGuTeoZ9dtd4=
-golang.org/x/crypto v0.0.0-20210921155107-089bfa567519 h1:7I4JAnoQBe7ZtJcBaYHi5UtiO8tQHbUSXxL+pnGRANg=
 golang.org/x/crypto v0.0.0-20210921155107-089bfa567519/go.mod h1:GvvjBRRGRdwPK5ydBHafDWAxML/pGHZbMvKqRZ5+Abc=
 golang.org/x/crypto v0.0.0-20221012134737-56aed061732a h1:NmSIgad6KjE6VvHciPZuNRTKxGhlPfD6OA87W/PLkqg=
 golang.org/x/crypto v0.0.0-20221012134737-56aed061732a/go.mod h1:IxCIyHEi3zRg3s0A5j5BB6A9Jmi73HwBIUl50j+osU4=
@@ -58,8 +55,6 @@ golang.org/x/exp v0.0.0-20190731235908-ec7cb31e5a56/go.mod h1:JhuoJpWY28nO4Vef9t
 golang.org/x/image v0.0.0-20190227222117-0694c2d4d067/go.mod h1:kZ7UVZpmo3dzQBMxlp+ypCbDeSB+sBbTgSJuh5dn5js=
 golang.org/x/image v0.0.0-20190802002840-cff245a6509b/go.mod h1:FeLwcggjj3mMvU+oOTbSwawSJRM1uh48EjtB4UJZlP0=
 golang.org/x/mobile v0.0.0-20190312151609-d3739f865fa6/go.mod h1:z+o9i4GpDbdi3rU15maQ/Ox0txvL9dWGYEHz965HBQE=
-golang.org/x/mobile v0.0.0-20220722155234-aaac322e2105 h1:3vUV5x5+3LfQbgk7paCM6INOaJG9xXQbn79xoNkwfIk=
-golang.org/x/mobile v0.0.0-20220722155234-aaac322e2105/go.mod h1:pe2sM7Uk+2Su1y7u/6Z8KJ24D7lepUjFZbhFOrmDfuQ=
 golang.org/x/mobile v0.0.0-20221012134814-c746ac228303 h1:K4fp1rDuJBz0FCPAWzIJwnzwNEM7S6yobdZzMrZ/Zws=
 golang.org/x/mobile v0.0.0-20221012134814-c746ac228303/go.mod h1:M32cGdzp91A8Ex9qQtyZinr19EYxzkFqDjW2oyHzTDQ=
 golang.org/x/mod v0.1.0/go.mod h1:0QHyrYULN0/3qlju5TqG8bIK38QM8yzMo5ekMj3DlcY=
@@ -73,7 +68,7 @@ golang.org/x/net v0.0.0-20210226172049-e18ecbb05110/go.mod h1:m0MpNAwzfU5UDzcl9v
 golang.org/x/net v0.0.0-20210805182204-aaa1db679c0d/go.mod h1:9nx3DQGgdP8bBQD5qxJ1jj9UTztislL4KSBs9R2vV5Y=
 golang.org/x/net v0.0.0-20210927181540-4e4d966f7476/go.mod h1:9nx3DQGgdP8bBQD5qxJ1jj9UTztislL4KSBs9R2vV5Y=
 golang.org/x/net v0.0.0-20211011170408-caeb26a5c8c0/go.mod h1:9nx3DQGgdP8bBQD5qxJ1jj9UTztislL4KSBs9R2vV5Y=
-golang.org/x/net v0.0.0-20220722155237-a158d28d115b h1:PxfKdU9lEEDYjdIzOtC4qFWgkU2rGHdKlKowJSMN9h0=
+golang.org/x/net v0.0.0-20211112202133-69e39bad7dc2/go.mod h1:9nx3DQGgdP8bBQD5qxJ1jj9UTztislL4KSBs9R2vV5Y=
 golang.org/x/net v0.0.0-20220722155237-a158d28d115b/go.mod h1:XRhObCWvk6IyKnWLug+ECip1KBveYUHfp+8e9klMJ9c=
 golang.org/x/net v0.0.0-20221014081412-f15817d10f9b h1:tvrvnPFcdzp294diPnrdZZZ8XUt2Tyj7svb7X52iDuU=
 golang.org/x/net v0.0.0-20221014081412-f15817d10f9b/go.mod h1:YDH+HFinaLZZlnHAfSS6ZXJJ9M9t4Dl22yv3iI2vPwk=
@@ -87,7 +82,6 @@ golang.org/x/sys v0.0.0-20190606203320-7fc4e5ec1444/go.mod h1:h1NjWce9XRLGQEsW7w
 golang.org/x/sys v0.0.0-20200116001909-b77594299b42/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20200217220822-9197077df867/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20200223170610-d5e6a3e2c0ae/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
-golang.org/x/sys v0.0.0-20200602225109-6fdc65e7d980/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20201018230417-eeed37f84f13/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20201119102817-f84b799fce68/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20210403161142-5e06dd20ab57/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
@@ -97,9 +91,7 @@ golang.org/x/sys v0.0.0-20210809222454-d867a43fc93e/go.mod h1:oPkhp1MJrh7nUepCBc
 golang.org/x/sys v0.0.0-20210927094055-39ccf1dd6fa6/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.0.0-20211007075335-d3039528d8ac/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.0.0-20220520151302-bc2c85ada10a/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
-golang.org/x/sys v0.0.0-20220722155257-8c9f86f7a55f h1:v4INt8xihDGvnrfjMDVXGxw9wrfxYyCjk0KbXjhR55s=
 golang.org/x/sys v0.0.0-20220722155257-8c9f86f7a55f/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
-golang.org/x/sys v0.0.0-20220728004956-3c1f35247d10 h1:WIoqL4EROvwiPdUtaip4VcDdpZ4kha7wBWZrbVKCIZg=
 golang.org/x/sys v0.0.0-20220728004956-3c1f35247d10/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.0.0-20221013171732-95e765b1cc43 h1:OK7RB6t2WQX54srQQYSXMW8dF5C6/8+oA/s5QBmmto4=
 golang.org/x/sys v0.0.0-20221013171732-95e765b1cc43/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
@@ -109,7 +101,6 @@ golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
 golang.org/x/text v0.3.3/go.mod h1:5Zoc/QRtKVWzQhOtBMvqHzDpF6irO9z98xDceosuGiQ=
 golang.org/x/text v0.3.6/go.mod h1:5Zoc/QRtKVWzQhOtBMvqHzDpF6irO9z98xDceosuGiQ=
 golang.org/x/text v0.3.7/go.mod h1:u+2+/6zg+i71rQMx5EYifcz6MCKuco9NR6JIITiCfzQ=
-golang.org/x/text v0.3.8-0.20211004125949-5bd84dd9b33b h1:NXqSWXSRUSCaFuvitrWtU169I3876zRTalMRbfd6LL0=
 golang.org/x/text v0.3.8-0.20211004125949-5bd84dd9b33b/go.mod h1:EFNZuWvGYxIRUEX+K8UmCFwYmZjqcrnq15ZuVldZkZ0=
 golang.org/x/text v0.3.8 h1:nAL+RVCQ9uMn3vJZbV+MRnydTJFPf8qqY42YiA6MrqY=
 golang.org/x/text v0.3.8/go.mod h1:E6s5w1FMmriuDzIBO73fBruAKo1PCIq6d2Q6DHfQ8WQ=

src/admin/getpeers.go

@@ -19,6 +19,7 @@ type PeerEntry struct {
 	IPAddress string   `json:"address"`
 	PublicKey string   `json:"key"`
 	Port      uint64   `json:"port"`
+	Priority  uint8    `json:"priority"`
 	Coords    []uint64 `json:"coords"`
 	Remote    string   `json:"remote"`
 	RXBytes   DataUnit `json:"bytes_recvd"`
@@ -35,6 +36,7 @@ func (a *AdminSocket) getPeersHandler(req *GetPeersRequest, res *GetPeersRespons
 			IPAddress: net.IP(addr[:]).String(),
 			PublicKey: hex.EncodeToString(p.Key),
 			Port:      p.Port,
+			Priority:  p.Priority,
 			Coords:    p.Coords,
 			Remote:    p.Remote,
 			RXBytes:   DataUnit(p.RXBytes),
@@ -43,6 +45,9 @@ func (a *AdminSocket) getPeersHandler(req *GetPeersRequest, res *GetPeersRespons
 		})
 	}
 	sort.Slice(res.Peers, func(i, j int) bool {
+		if res.Peers[i].Port == res.Peers[j].Port {
+			return res.Peers[i].Priority < res.Peers[j].Priority
+		}
 		return res.Peers[i].Port < res.Peers[j].Port
 	})
 	return nil

src/config/config.go

@@ -40,10 +40,11 @@ type NodeConfig struct {
 }
 
 type MulticastInterfaceConfig struct {
-	Regex  string
+	Regex    string
-	Beacon bool
+	Beacon   bool
-	Listen bool
+	Listen   bool
-	Port   uint16
+	Port     uint16
+	Priority uint8
 }
 
 // NewSigningKeys replaces the signing keypair in the NodeConfig with a new

src/core/api.go

@@ -20,14 +20,15 @@ type SelfInfo struct {
 }
 
 type PeerInfo struct {
-	Key     ed25519.PublicKey
+	Key      ed25519.PublicKey
-	Root    ed25519.PublicKey
+	Root     ed25519.PublicKey
-	Coords  []uint64
+	Coords   []uint64
-	Port    uint64
+	Port     uint64
-	Remote  string
+	Priority uint8
-	RXBytes uint64
+	Remote   string
-	TXBytes uint64
+	RXBytes  uint64
-	Uptime  time.Duration
+	TXBytes  uint64
+	Uptime   time.Duration
 }
 
 type DHTEntryInfo struct {
@@ -62,6 +63,9 @@ func (c *Core) GetPeers() []PeerInfo {
 	names := make(map[net.Conn]string)
 	phony.Block(&c.links, func() {
 		for _, info := range c.links._links {
+			if info == nil {
+				continue
+			}
 			names[info.conn] = info.lname
 		}
 	})
@@ -72,6 +76,7 @@ func (c *Core) GetPeers() []PeerInfo {
 		info.Root = p.Root
 		info.Coords = p.Coords
 		info.Port = p.Port
+		info.Priority = p.Priority
 		info.Remote = p.Conn.RemoteAddr().String()
 		if name := names[p.Conn]; name != "" {
 			info.Remote = name

src/core/link.go

@@ -8,6 +8,7 @@ import (
 	"io"
 	"net"
 	"net/url"
+	"strconv"
 	"strings"
 	"sync/atomic"
 	"time"
@@ -45,6 +46,7 @@ type link struct {
 
 type linkOptions struct {
 	pinnedEd25519Keys map[keyArray]struct{}
+	priority          uint8
 }
 
 type Listener struct {
@@ -120,17 +122,24 @@ func (l *links) call(u *url.URL, sintf string) (linkInfo, error) {
 		copy(sigPubKey[:], sigPub)
 		options.pinnedEd25519Keys[sigPubKey] = struct{}{}
 	}
+	if p := u.Query().Get("priority"); p != "" {
+		pi, err := strconv.ParseUint(p, 10, 8)
+		if err != nil {
+			return info, fmt.Errorf("priority invalid: %w", err)
+		}
+		options.priority = uint8(pi)
+	}
 	switch info.linkType {
 	case "tcp":
 		go func() {
-			if err := l.tcp.dial(u, options, sintf); err != nil {
+			if err := l.tcp.dial(u, options, sintf); err != nil && err != io.EOF {
 				l.core.log.Warnf("Failed to dial TCP %s: %s\n", u.Host, err)
 			}
 		}()
 
 	case "socks":
 		go func() {
-			if err := l.socks.dial(u, options); err != nil {
+			if err := l.socks.dial(u, options); err != nil && err != io.EOF {
 				l.core.log.Warnf("Failed to dial SOCKS %s: %s\n", u.Host, err)
 			}
 		}()
@@ -154,14 +163,14 @@ func (l *links) call(u *url.URL, sintf string) (linkInfo, error) {
 			}
 		}
 		go func() {
-			if err := l.tls.dial(u, options, sintf, tlsSNI); err != nil {
+			if err := l.tls.dial(u, options, sintf, tlsSNI); err != nil && err != io.EOF {
 				l.core.log.Warnf("Failed to dial TLS %s: %s\n", u.Host, err)
 			}
 		}()
 
 	case "unix":
 		go func() {
-			if err := l.unix.dial(u, options, sintf); err != nil {
+			if err := l.unix.dial(u, options, sintf); err != nil && err != io.EOF {
 				l.core.log.Warnf("Failed to dial UNIX %s: %s\n", u.Host, err)
 			}
 		}()
@@ -272,8 +281,7 @@ func (intf *link) handler() error {
 		var key keyArray
 		copy(key[:], meta.key)
 		if _, allowed := pinned[key]; !allowed {
-			intf.links.core.log.Errorf("Failed to connect to node: %q sent ed25519 key that does not match pinned keys", intf.name())
+			return fmt.Errorf("node public key that does not match pinned keys")
-			return fmt.Errorf("failed to connect: host sent ed25519 key that does not match pinned keys")
 		}
 	}
 	// Check if we're authorized to connect to this key / IP
@@ -286,31 +294,33 @@ func (intf *link) handler() error {
 		}
 	}
 	if intf.incoming && !intf.force && !isallowed {
-		intf.links.core.log.Warnf("%s connection from %s forbidden: AllowedEncryptionPublicKeys does not contain key %s",
-			strings.ToUpper(intf.info.linkType), intf.info.remote, hex.EncodeToString(meta.key))
 		_ = intf.close()
-		return fmt.Errorf("forbidden connection")
+		return fmt.Errorf("node public key %q is not in AllowedPublicKeys", hex.EncodeToString(meta.key))
 	}
 
 	phony.Block(intf.links, func() {
 		intf.links._links[intf.info] = intf
 	})
 
+	dir := "outbound"
+	if intf.incoming {
+		dir = "inbound"
+	}
 	remoteAddr := net.IP(address.AddrForKey(meta.key)[:]).String()
 	remoteStr := fmt.Sprintf("%s@%s", remoteAddr, intf.info.remote)
 	localStr := intf.conn.LocalAddr()
-	intf.links.core.log.Infof("Connected %s: %s, source %s",
+	intf.links.core.log.Infof("Connected %s %s: %s, source %s",
-		strings.ToUpper(intf.info.linkType), remoteStr, localStr)
+		dir, strings.ToUpper(intf.info.linkType), remoteStr, localStr)
 
-	// TODO don't report an error if it's just a 'use of closed network connection'
+	err = intf.links.core.HandleConn(meta.key, intf.conn, intf.options.priority)
-	if err = intf.links.core.HandleConn(meta.key, intf.conn); err != nil && err != io.EOF {
+	switch err {
-		intf.links.core.log.Infof("Disconnected %s: %s, source %s; error: %s",
+	case io.EOF, net.ErrClosed, nil:
-			strings.ToUpper(intf.info.linkType), remoteStr, localStr, err)
+		intf.links.core.log.Infof("Disconnected %s %s: %s, source %s",
-	} else {
+			dir, strings.ToUpper(intf.info.linkType), remoteStr, localStr)
-		intf.links.core.log.Infof("Disconnected %s: %s, source %s",
+	default:
-			strings.ToUpper(intf.info.linkType), remoteStr, localStr)
+		intf.links.core.log.Infof("Disconnected %s %s: %s, source %s; error: %s",
+			dir, strings.ToUpper(intf.info.linkType), remoteStr, localStr, err)
 	}
-
 	return nil
 }
 
@@ -318,14 +328,7 @@ func (intf *link) close() error {
 	return intf.conn.Close()
 }
 
-func (intf *link) name() string {
-	return intf.lname
-}
-
 func linkInfoFor(linkType, sintf, remote string) linkInfo {
-	if h, _, err := net.SplitHostPort(remote); err == nil {
-		remote = h
-	}
 	return linkInfo{
 		linkType: linkType,
 		local:    sintf,
@@ -353,3 +356,12 @@ func (c *linkConn) Write(p []byte) (n int, err error) {
 	atomic.AddUint64(&c.tx, uint64(n))
 	return
 }
+
+func linkOptionsForListener(u *url.URL) (l linkOptions) {
+	if p := u.Query().Get("priority"); p != "" {
+		if pi, err := strconv.ParseUint(p, 10, 8); err == nil {
+			l.priority = uint8(pi)
+		}
+	}
+	return
+}

src/core/link_socks.go

@@ -23,7 +23,7 @@ func (l *links) newLinkSOCKS() *linkSOCKS {
 func (l *linkSOCKS) dial(url *url.URL, options linkOptions) error {
 	info := linkInfoFor("socks", "", url.Path)
 	if l.links.isConnectedTo(info) {
-		return fmt.Errorf("duplicate connection attempt")
+		return nil
 	}
 	proxyAuth := &proxy.Auth{}
 	proxyAuth.User = url.User.Username()

src/core/link_tcp.go

@@ -31,24 +31,24 @@ func (l *links) newLinkTCP() *linkTCP {
 }
 
 func (l *linkTCP) dial(url *url.URL, options linkOptions, sintf string) error {
-	info := linkInfoFor("tcp", sintf, strings.SplitN(url.Host, "%", 2)[0])
-	if l.links.isConnectedTo(info) {
-		return fmt.Errorf("duplicate connection attempt")
-	}
 	addr, err := net.ResolveTCPAddr("tcp", url.Host)
 	if err != nil {
 		return err
 	}
-	addr.Zone = sintf
+	dialer, err := l.dialerFor(addr, sintf)
-	dialer, err := l.dialerFor(addr.String(), sintf)
 	if err != nil {
 		return err
 	}
+	info := linkInfoFor("tcp", sintf, tcpIDFor(dialer.LocalAddr, addr))
+	if l.links.isConnectedTo(info) {
+		return nil
+	}
 	conn, err := dialer.DialContext(l.core.ctx, "tcp", addr.String())
 	if err != nil {
 		return err
 	}
-	return l.handler(url.String(), info, conn, options, false)
+	uri := strings.TrimRight(strings.SplitN(url.String(), "?", 2)[0], "/")
+	return l.handler(uri, info, conn, options, false, false)
 }
 
 func (l *linkTCP) listen(url *url.URL, sintf string) (*Listener, error) {
@@ -82,10 +82,11 @@ func (l *linkTCP) listen(url *url.URL, sintf string) (*Listener, error) {
 				cancel()
 				break
 			}
-			addr := conn.RemoteAddr().(*net.TCPAddr)
+			laddr := conn.LocalAddr().(*net.TCPAddr)
-			name := fmt.Sprintf("tls://%s", addr)
+			raddr := conn.RemoteAddr().(*net.TCPAddr)
-			info := linkInfoFor("tcp", sintf, strings.SplitN(addr.IP.String(), "%", 2)[0])
+			name := fmt.Sprintf("tcp://%s", raddr)
-			if err = l.handler(name, info, conn, linkOptions{}, true); err != nil {
+			info := linkInfoFor("tcp", sintf, tcpIDFor(laddr, raddr))
+			if err = l.handler(name, info, conn, linkOptionsForListener(url), true, raddr.IP.IsLinkLocalUnicast()); err != nil {
 				l.core.log.Errorln("Failed to create inbound link:", err)
 			}
 		}
@@ -96,13 +97,13 @@ func (l *linkTCP) listen(url *url.URL, sintf string) (*Listener, error) {
 	return entry, nil
 }
 
-func (l *linkTCP) handler(name string, info linkInfo, conn net.Conn, options linkOptions, incoming bool) error {
+func (l *linkTCP) handler(name string, info linkInfo, conn net.Conn, options linkOptions, incoming, force bool) error {
 	return l.links.create(
 		conn,     // connection
 		name,     // connection name
 		info,     // connection info
 		incoming, // not incoming
-		false,    // not forced
+		force,    // not forced
 		options,  // connection options
 	)
 }
@@ -121,13 +122,11 @@ func (l *linkTCP) getAddr() *net.TCPAddr {
 	return addr
 }
 
-func (l *linkTCP) dialerFor(saddr, sintf string) (*net.Dialer, error) {
+func (l *linkTCP) dialerFor(dst *net.TCPAddr, sintf string) (*net.Dialer, error) {
-	dst, err := net.ResolveTCPAddr("tcp", saddr)
-	if err != nil {
-		return nil, err
-	}
 	if dst.IP.IsLinkLocalUnicast() {
-		dst.Zone = sintf
+		if sintf != "" {
+			dst.Zone = sintf
+		}
 		if dst.Zone == "" {
 			return nil, fmt.Errorf("link-local address requires a zone")
 		}
@@ -181,3 +180,16 @@ func (l *linkTCP) dialerFor(saddr, sintf string) (*net.Dialer, error) {
 	}
 	return dialer, nil
 }
+
+func tcpIDFor(local net.Addr, remoteAddr *net.TCPAddr) string {
+	if localAddr, ok := local.(*net.TCPAddr); ok && localAddr.IP.Equal(remoteAddr.IP) {
+		// Nodes running on the same host — include both the IP and port.
+		return remoteAddr.String()
+	}
+	if remoteAddr.IP.IsLinkLocalUnicast() {
+		// Nodes discovered via multicast — include the IP only.
+		return remoteAddr.IP.String()
+	}
+	// Nodes connected remotely — include both the IP and port.
+	return remoteAddr.String()
+}

src/core/link_tls.go

@@ -47,19 +47,18 @@ func (l *links) newLinkTLS(tcp *linkTCP) *linkTLS {
 }
 
 func (l *linkTLS) dial(url *url.URL, options linkOptions, sintf, sni string) error {
-	info := linkInfoFor("tls", sintf, strings.SplitN(url.Host, "%", 2)[0])
-	if l.links.isConnectedTo(info) {
-		return fmt.Errorf("duplicate connection attempt")
-	}
 	addr, err := net.ResolveTCPAddr("tcp", url.Host)
 	if err != nil {
 		return err
 	}
-	addr.Zone = sintf
+	dialer, err := l.tcp.dialerFor(addr, sintf)
-	dialer, err := l.tcp.dialerFor(addr.String(), sintf)
 	if err != nil {
 		return err
 	}
+	info := linkInfoFor("tls", sintf, tcpIDFor(dialer.LocalAddr, addr))
+	if l.links.isConnectedTo(info) {
+		return nil
+	}
 	tlsconfig := l.config.Clone()
 	tlsconfig.ServerName = sni
 	tlsdialer := &tls.Dialer{
@@ -70,7 +69,8 @@ func (l *linkTLS) dial(url *url.URL, options linkOptions, sintf, sni string) err
 	if err != nil {
 		return err
 	}
-	return l.handler(url.String(), info, conn, options, false)
+	uri := strings.TrimRight(strings.SplitN(url.String(), "?", 2)[0], "/")
+	return l.handler(uri, info, conn, options, false, false)
 }
 
 func (l *linkTLS) listen(url *url.URL, sintf string) (*Listener, error) {
@@ -105,10 +105,11 @@ func (l *linkTLS) listen(url *url.URL, sintf string) (*Listener, error) {
 				cancel()
 				break
 			}
-			addr := conn.RemoteAddr().(*net.TCPAddr)
+			laddr := conn.LocalAddr().(*net.TCPAddr)
-			name := fmt.Sprintf("tls://%s", addr)
+			raddr := conn.RemoteAddr().(*net.TCPAddr)
-			info := linkInfoFor("tls", sintf, strings.SplitN(addr.IP.String(), "%", 2)[0])
+			name := fmt.Sprintf("tls://%s", raddr)
-			if err = l.handler(name, info, conn, linkOptions{}, true); err != nil {
+			info := linkInfoFor("tls", sintf, tcpIDFor(laddr, raddr))
+			if err = l.handler(name, info, conn, linkOptionsForListener(url), true, raddr.IP.IsLinkLocalUnicast()); err != nil {
 				l.core.log.Errorln("Failed to create inbound link:", err)
 			}
 		}
@@ -166,6 +167,6 @@ func (l *linkTLS) generateConfig() (*tls.Config, error) {
 	}, nil
 }
 
-func (l *linkTLS) handler(name string, info linkInfo, conn net.Conn, options linkOptions, incoming bool) error {
+func (l *linkTLS) handler(name string, info linkInfo, conn net.Conn, options linkOptions, incoming, force bool) error {
-	return l.tcp.handler(name, info, conn, options, incoming)
+	return l.tcp.handler(name, info, conn, options, incoming, force)
 }

src/core/link_unix.go

@@ -2,7 +2,6 @@ package core
 
 import (
 	"context"
-	"fmt"
 	"net"
 	"net/url"
 	"time"
@@ -36,7 +35,7 @@ func (l *links) newLinkUNIX() *linkUNIX {
 func (l *linkUNIX) dial(url *url.URL, options linkOptions, _ string) error {
 	info := linkInfoFor("unix", "", url.Path)
 	if l.links.isConnectedTo(info) {
-		return fmt.Errorf("duplicate connection attempt")
+		return nil
 	}
 	addr, err := net.ResolveUnixAddr("unix", url.Path)
 	if err != nil {
@@ -75,7 +74,7 @@ func (l *linkUNIX) listen(url *url.URL, _ string) (*Listener, error) {
 				break
 			}
 			info := linkInfoFor("unix", "", url.String())
-			if err = l.handler(url.String(), info, conn, linkOptions{}, true); err != nil {
+			if err = l.handler(url.String(), info, conn, linkOptionsForListener(url), true); err != nil {
 				l.core.log.Errorln("Failed to create inbound link:", err)
 			}
 		}

src/multicast/multicast.go

@@ -37,11 +37,12 @@ type Multicast struct {
 }
 
 type interfaceInfo struct {
-	iface  net.Interface
+	iface    net.Interface
-	addrs  []net.Addr
+	addrs    []net.Addr
-	beacon bool
+	beacon   bool
-	listen bool
+	listen   bool
-	port   uint16
+	port     uint16
+	priority uint8
 }
 
 type listenerInfo struct {
@@ -77,7 +78,11 @@ func (m *Multicast) _start() error {
 	if m._isOpen {
 		return fmt.Errorf("multicast module is already started")
 	}
-	if len(m.config._interfaces) == 0 {
+	var anyEnabled bool
+	for intf := range m.config._interfaces {
+		anyEnabled = anyEnabled || intf.Beacon || intf.Listen
+	}
+	if !anyEnabled {
 		return nil
 	}
 	m.log.Debugln("Starting multicast module")
@@ -190,10 +195,11 @@ func (m *Multicast) _getAllowedInterfaces() map[string]*interfaceInfo {
 				continue
 			}
 			interfaces[iface.Name] = &interfaceInfo{
-				iface:  iface,
+				iface:    iface,
-				beacon: ifcfg.Beacon,
+				beacon:   ifcfg.Beacon,
-				listen: ifcfg.Listen,
+				listen:   ifcfg.Listen,
-				port:   ifcfg.Port,
+				port:     ifcfg.Port,
+				priority: ifcfg.Priority,
 			}
 			break
 		}
@@ -383,7 +389,7 @@ func (m *Multicast) listen() {
 		})
 		if info, ok := interfaces[from.Zone]; ok && info.listen {
 			addr.Zone = ""
-			pin := fmt.Sprintf("/?key=%s", hex.EncodeToString(key))
+			pin := fmt.Sprintf("/?key=%s&priority=%d", hex.EncodeToString(key), info.priority)
 			u, err := url.Parse("tls://" + addr.String() + pin)
 			if err != nil {
 				m.log.Debugln("Call from multicast failed, parse error:", addr.String(), err)

src/multicast/multicast_unix.go

@@ -15,15 +15,19 @@ func (m *Multicast) _multicastStarted() {
 
 func (m *Multicast) multicastReuse(network string, address string, c syscall.RawConn) error {
 	var control error
-	var reuseport error
+	var reuseaddr error
 
 	control = c.Control(func(fd uintptr) {
-		reuseport = unix.SetsockoptInt(int(fd), unix.SOL_SOCKET, unix.SO_REUSEPORT, 1)
+		// Previously we used SO_REUSEPORT here, but that meant that machines running
+		// Yggdrasil nodes as different users would inevitably fail with EADDRINUSE.
+		// The behaviour for multicast is similar with both, so we'll use SO_REUSEADDR
+		// instead.
+		reuseaddr = unix.SetsockoptInt(int(fd), unix.SOL_SOCKET, unix.SO_REUSEADDR, 1)
 	})
 
 	switch {
-	case reuseport != nil:
+	case reuseaddr != nil:
-		return reuseport
+		return reuseaddr
 	default:
 		return control
 	}

src/multicast/options.go

@@ -16,10 +16,11 @@ type SetupOption interface {
 }
 
 type MulticastInterface struct {
-	Regex  *regexp.Regexp
+	Regex    *regexp.Regexp
-	Beacon bool
+	Beacon   bool
-	Listen bool
+	Listen   bool
-	Port   uint16
+	Port     uint16
+	Priority uint8
 }
 
 type GroupAddress string