Bug fixes

Refactoring and code cleanup. Improved client command interface.

README.md

@@ -1,8 +1,10 @@
 # vppn: Virtual Potentially Private Network
 
-## TODO
+## TO DO
 
-* Add `-force-init` argument to `node` main?
+* peer - write status to file instead of using sockets
+* peer - improve relay selection
+* Double buffering in IFReader and ConnReader ?
 
 ## Hub Server Configuration
 
@@ -13,7 +15,6 @@ adduser user
 # Enable ssh.
 cp -r ~/.ssh /home/user/
 chown -R user:user /home/user/.ssh
-
 ```
 
 Upload `hub` executable:
@@ -33,7 +34,6 @@ WorkingDirectory=/home/user/
 ExecStart=/home/user/hub -listen <addr>:https -root-dir=/home/user
 Restart=always
 RestartSec=8
-TimeoutStopSec=24
 
 [Install]
 WantedBy=default.target
@@ -43,6 +43,7 @@ Add and start the hub server:
 
 ```
 systemctl daemon-reload
+systemctl enable hub
 systemctl start hub
 ```
 
@@ -60,18 +61,25 @@ Install the binary somewhere, for example `~/bin/vppn`.
 
 Create systemd file in `/etc/systemd/system/vppn.service`.
 
-
 ```
 [Service]
 AmbientCapabilities=CAP_NET_BIND_SERVICE CAP_NET_ADMIN
 Type=simple
 User=user
 WorkingDirectory=/home/user/
-ExecStart=/home/user/vppn -name vppn -hub-address https://my.hub -api-key 1234567890
+ExecStart=/home/user/vppn run my_net_name https://my.hub my_api_key
 Restart=always
 RestartSec=8
 TimeoutStopSec=24
 
 [Install]
-WantedBy=default.target
+WantedBy=multi-user.target
+```
+
+Add and start the service:
+
+```
+systemctl daemon-reload
+systemctl enable vppn
+systemctl start vppn
 ```

cmd/vppn/main.go

@@ -2,10 +2,10 @@ package main
 
 import (
 	"log"
-	"vppn/node"
+	"vppn/peer"
 )
 
 func main() {
 	log.SetFlags(0)
-	node.Main()
+	peer.Main2()
 }

go.mod

@@ -1,17 +1,15 @@
 module vppn
 
-go 1.23.2
+go 1.25.1
 
 require (
-	git.crumpington.com/lib/go v0.8.1
-	git.crumpington.com/lib/webutil v0.0.7
-	github.com/songgao/water v0.0.0-20200317203138-2b4b6d7c09d8
-	golang.org/x/crypto v0.29.0
+	git.crumpington.com/lib/go v0.9.1
+	golang.org/x/crypto v0.42.0
+	golang.org/x/sys v0.36.0
 )
 
 require (
-	github.com/mattn/go-sqlite3 v1.14.24 // indirect
-	golang.org/x/net v0.31.0 // indirect
-	golang.org/x/sys v0.27.0 // indirect
-	golang.org/x/text v0.20.0 // indirect
+	github.com/mattn/go-sqlite3 v1.14.32 // indirect
+	golang.org/x/net v0.44.0 // indirect
+	golang.org/x/text v0.29.0 // indirect
 )

go.sum

@@ -1,16 +1,12 @@
-git.crumpington.com/lib/go v0.8.1 h1:rWjddllSxQ4yReraqDaGZAod4NpRD9LtGx1yV71ytcU=
-git.crumpington.com/lib/go v0.8.1/go.mod h1:XjQaf2NFlje9BJ1EevZL8NNioPrAe7WwHpKUhcDw2Lk=
-git.crumpington.com/lib/webutil v0.0.7 h1:1RG9CpuXYalT0NPj8fvxjOLV566LqL37APvAdASFzgA=
-git.crumpington.com/lib/webutil v0.0.7/go.mod h1:efIEiuK1uqFIhI/dlsWUHMsC5bXcEbJEjmdluRoFPPQ=
-github.com/mattn/go-sqlite3 v1.14.24 h1:tpSp2G2KyMnnQu99ngJ47EIkWVmliIizyZBfPrBWDRM=
-github.com/mattn/go-sqlite3 v1.14.24/go.mod h1:Uh1q+B4BYcTPb+yiD3kU8Ct7aC0hY9fxUwlHK0RXw+Y=
-github.com/songgao/water v0.0.0-20200317203138-2b4b6d7c09d8 h1:TG/diQgUe0pntT/2D9tmUCz4VNwm9MfrtPr0SU2qSX8=
-github.com/songgao/water v0.0.0-20200317203138-2b4b6d7c09d8/go.mod h1:P5HUIBuIWKbyjl083/loAegFkfbFNx5i2qEP4CNbm7E=
-golang.org/x/crypto v0.29.0 h1:L5SG1JTTXupVV3n6sUqMTeWbjAyfPwoda2DLX8J8FrQ=
-golang.org/x/crypto v0.29.0/go.mod h1:+F4F4N5hv6v38hfeYwTdx20oUvLLc+QfrE9Ax9HtgRg=
-golang.org/x/net v0.31.0 h1:68CPQngjLL0r2AlUKiSxtQFKvzRVbnzLwMUn5SzcLHo=
-golang.org/x/net v0.31.0/go.mod h1:P4fl1q7dY2hnZFxEk4pPSkDHF+QqjitcnDjUQyMM+pM=
-golang.org/x/sys v0.27.0 h1:wBqf8DvsY9Y/2P8gAfPDEYNuS30J4lPHJxXSb/nJZ+s=
-golang.org/x/sys v0.27.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
-golang.org/x/text v0.20.0 h1:gK/Kv2otX8gz+wn7Rmb3vT96ZwuoxnQlY+HlJVj7Qug=
-golang.org/x/text v0.20.0/go.mod h1:D4IsuqiFMhST5bX19pQ9ikHC2GsaKyk/oF+pn3ducp4=
+git.crumpington.com/lib/go v0.9.1 h1:xLBzcgiZRB6Ky3Ce9hKE+Ko0YbkA4USF4eJk5i5RJF4=
+git.crumpington.com/lib/go v0.9.1/go.mod h1:5nnfjdnUnj/FHhakaliKQKsKeSkUb0GEUKF3PqRgUXg=
+github.com/mattn/go-sqlite3 v1.14.32 h1:JD12Ag3oLy1zQA+BNn74xRgaBbdhbNIDYvQUEuuErjs=
+github.com/mattn/go-sqlite3 v1.14.32/go.mod h1:Uh1q+B4BYcTPb+yiD3kU8Ct7aC0hY9fxUwlHK0RXw+Y=
+golang.org/x/crypto v0.42.0 h1:chiH31gIWm57EkTXpwnqf8qeuMUi0yekh6mT2AvFlqI=
+golang.org/x/crypto v0.42.0/go.mod h1:4+rDnOTJhQCx2q7/j6rAN5XDw8kPjeaXEUR2eL94ix8=
+golang.org/x/net v0.44.0 h1:evd8IRDyfNBMBTTY5XRF1vaZlD+EmWx6x8PkhR04H/I=
+golang.org/x/net v0.44.0/go.mod h1:ECOoLqd5U3Lhyeyo/QDCEVQ4sNgYsqvCZ722XogGieY=
+golang.org/x/sys v0.36.0 h1:KVRy2GtZBrk1cBYA7MKu5bEZFxQk4NIDV6RLVcC8o0k=
+golang.org/x/sys v0.36.0/go.mod h1:OgkHotnGiDImocRcuBABYBEXf8A9a87e/uXjp9XT3ks=
+golang.org/x/text v0.29.0 h1:1neNs90w9YzJ9BocxfsQNHKuAT4pkghyXc4nhZ6sJvk=
+golang.org/x/text v0.29.0/go.mod h1:7MhJOA9CD2qZyOKYazxdYMF85OwPdEr9jTtBpO7ydH4=

hub/api/api.go

@@ -54,17 +54,11 @@ func (a *API) ensurePassword() error {
 	log.Printf("Setting password: %s", pwd)
 
 	hashed, err := bcrypt.GenerateFromPassword([]byte(pwd), bcrypt.DefaultCost)
-
 	if err != nil {
 		return err
 	}
 
-	conf := &Config{
-		ConfigID:   1,
-		VPNNetwork: []byte{10, 1, 1, 0},
-		Password:   hashed,
-	}
-
+	conf := &Config{ConfigID: 1, Password: hashed}
 	return db.Config_Insert(a.db, conf)
 }
 
@@ -80,10 +74,6 @@ func (a *API) Config_Update(conf *Config) error {
 	return db.Config_Update(a.db, conf)
 }
 
-func (a *API) Config_UpdatePassword(pwdHash []byte) error {
-	return db.Config_UpdatePassword(a.db, pwdHash)
-}
-
 func (a *API) Session_Delete(sessionID string) error {
 	return db.Session_Delete(a.db, sessionID)
 }
@@ -137,6 +127,24 @@ func (a *API) Session_SignIn(s *Session, pwd string) error {
 	return db.Session_SetSignedIn(a.db, s.SessionID)
 }
 
+func (a *API) Network_Create(n *Network) error {
+	n.NetworkID = idgen.NextID(0)
+	return db.Network_Insert(a.db, n)
+}
+
+func (a *API) Network_Delete(n *Network) error {
+	return db.Network_Delete(a.db, n.NetworkID)
+}
+
+func (a *API) Network_Get(id int64) (*Network, error) {
+	return db.Network_Get(a.db, id)
+}
+
+func (a *API) Network_List() ([]*Network, error) {
+	const query = db.Network_SelectQuery + ` ORDER BY Name ASC`
+	return db.Network_List(a.db, query)
+}
+
 func (a *API) Peer_CreateNew(p *Peer) error {
 	p.Version = idgen.NextID(0)
 	p.PubKey = []byte{}
@@ -146,7 +154,7 @@ func (a *API) Peer_CreateNew(p *Peer) error {
 	return db.Peer_Insert(a.db, p)
 }
 
-func (a *API) Peer_Init(peer *Peer, args m.PeerInitArgs) (*m.PeerConfig, error) {
+func (a *API) Peer_Init(peer *Peer, args m.PeerInitArgs) error {
 	a.lock.Lock()
 	defer a.lock.Unlock()
 
@@ -154,19 +162,7 @@ func (a *API) Peer_Init(peer *Peer, args m.PeerInitArgs) (*m.PeerConfig, error)
 	peer.PubKey = args.EncPubKey
 	peer.PubSignKey = args.PubSignKey
 
-	if err := db.Peer_UpdateFull(a.db, peer); err != nil {
-		return nil, err
-	}
-
-	conf := a.Config_Get()
-
-	return &m.PeerConfig{
-		PeerIP:   peer.PeerIP,
-		Network:  conf.VPNNetwork,
-		PublicIP: peer.PublicIP,
-		Port:     peer.Port,
-		Relay:    peer.Relay,
-	}, nil
+	return db.Peer_UpdateFull(a.db, peer)
 }
 
 func (a *API) Peer_Update(p *Peer) error {
@@ -177,16 +173,16 @@ func (a *API) Peer_Update(p *Peer) error {
 	return db.Peer_Update(a.db, p)
 }
 
-func (a *API) Peer_Delete(ip byte) error {
-	return db.Peer_Delete(a.db, ip)
+func (a *API) Peer_Delete(networkID int64, peerIP byte) error {
+	return db.Peer_Delete(a.db, networkID, peerIP)
 }
 
-func (a *API) Peer_List() ([]*Peer, error) {
-	return db.Peer_ListAll(a.db)
+func (a *API) Peer_List(networkID int64) ([]*Peer, error) {
+	return db.Peer_ListAll(a.db, networkID)
 }
 
-func (a *API) Peer_Get(ip byte) (*Peer, error) {
-	return db.Peer_Get(a.db, ip)
+func (a *API) Peer_Get(networkID int64, ip byte) (*Peer, error) {
+	return db.Peer_Get(a.db, networkID, ip)
 }
 
 func (a *API) Peer_GetByAPIKey(key string) (*Peer, error) {

hub/api/db/generated.go

@@ -16,13 +16,11 @@ type TX interface {
 // ----------------------------------------------------------------------------
 
 type Config struct {
-	ConfigID   int64
-	HubAddress string
-	VPNNetwork []byte
-	Password   []byte
+	ConfigID int64
+	Password []byte
 }
 
-const Config_SelectQuery = "SELECT ConfigID,HubAddress,VPNNetwork,Password FROM config"
+const Config_SelectQuery = "SELECT ConfigID,Password FROM config"
 
 func Config_Insert(
 	tx TX,
@@ -33,7 +31,7 @@ func Config_Insert(
 		return err
 	}
 
-	_, err = tx.Exec("INSERT INTO config(ConfigID,HubAddress,VPNNetwork,Password) VALUES(?,?,?,?)", row.ConfigID, row.HubAddress, row.VPNNetwork, row.Password)
+	_, err = tx.Exec("INSERT INTO config(ConfigID,Password) VALUES(?,?)", row.ConfigID, row.Password)
 	return err
 }
 
@@ -46,7 +44,7 @@ func Config_Update(
 		return err
 	}
 
-	result, err := tx.Exec("UPDATE config SET HubAddress=?,VPNNetwork=? WHERE ConfigID=?", row.HubAddress, row.VPNNetwork, row.ConfigID)
+	result, err := tx.Exec("UPDATE config SET Password=? WHERE ConfigID=?", row.Password, row.ConfigID)
 	if err != nil {
 		return err
 	}
@@ -74,7 +72,7 @@ func Config_UpdateFull(
 		return err
 	}
 
-	result, err := tx.Exec("UPDATE config SET HubAddress=?,VPNNetwork=?,Password=? WHERE ConfigID=?", row.HubAddress, row.VPNNetwork, row.Password, row.ConfigID)
+	result, err := tx.Exec("UPDATE config SET Password=? WHERE ConfigID=?", row.Password, row.ConfigID)
 	if err != nil {
 		return err
 	}
@@ -124,8 +122,8 @@ func Config_Get(
 	err error,
 ) {
 	row = &Config{}
-	r := tx.QueryRow("SELECT ConfigID,HubAddress,VPNNetwork,Password FROM config WHERE ConfigID=?", ConfigID)
-	err = r.Scan(&row.ConfigID, &row.HubAddress, &row.VPNNetwork, &row.Password)
+	r := tx.QueryRow("SELECT ConfigID,Password FROM config WHERE ConfigID=?", ConfigID)
+	err = r.Scan(&row.ConfigID, &row.Password)
 	return
 }
 
@@ -139,7 +137,7 @@ func Config_GetWhere(
 ) {
 	row = &Config{}
 	r := tx.QueryRow(query, args...)
-	err = r.Scan(&row.ConfigID, &row.HubAddress, &row.VPNNetwork, &row.Password)
+	err = r.Scan(&row.ConfigID, &row.Password)
 	return
 }
 
@@ -159,7 +157,7 @@ func Config_Iterate(
 		defer rows.Close()
 		for rows.Next() {
 			row := &Config{}
-			err := rows.Scan(&row.ConfigID, &row.HubAddress, &row.VPNNetwork, &row.Password)
+			err := rows.Scan(&row.ConfigID, &row.Password)
 			if !yield(row, err) {
 				return
 			}
@@ -302,11 +300,156 @@ func Session_List(
 	return l, nil
 }
 
+// ----------------------------------------------------------------------------
+// Table: networks
+// ----------------------------------------------------------------------------
+
+type Network struct {
+	NetworkID int64
+	Name      string
+	Network   []byte
+}
+
+const Network_SelectQuery = "SELECT NetworkID,Name,Network FROM networks"
+
+func Network_Insert(
+	tx TX,
+	row *Network,
+) (err error) {
+	Network_Sanitize(row)
+	if err = Network_Validate(row); err != nil {
+		return err
+	}
+
+	_, err = tx.Exec("INSERT INTO networks(NetworkID,Name,Network) VALUES(?,?,?)", row.NetworkID, row.Name, row.Network)
+	return err
+}
+
+func Network_UpdateFull(
+	tx TX,
+	row *Network,
+) (err error) {
+	Network_Sanitize(row)
+	if err = Network_Validate(row); err != nil {
+		return err
+	}
+
+	result, err := tx.Exec("UPDATE networks SET Name=?,Network=? WHERE NetworkID=?", row.Name, row.Network, row.NetworkID)
+	if err != nil {
+		return err
+	}
+
+	n, err := result.RowsAffected()
+	if err != nil {
+		panic(err)
+	}
+	switch n {
+	case 0:
+		return sql.ErrNoRows
+	case 1:
+		return nil
+	default:
+		panic("multiple rows updated")
+	}
+}
+
+func Network_Delete(
+	tx TX,
+	NetworkID int64,
+) (err error) {
+	result, err := tx.Exec("DELETE FROM networks WHERE NetworkID=?", NetworkID)
+	if err != nil {
+		return err
+	}
+
+	n, err := result.RowsAffected()
+	if err != nil {
+		panic(err)
+	}
+	switch n {
+	case 0:
+		return sql.ErrNoRows
+	case 1:
+		return nil
+	default:
+		panic("multiple rows deleted")
+	}
+}
+
+func Network_Get(
+	tx TX,
+	NetworkID int64,
+) (
+	row *Network,
+	err error,
+) {
+	row = &Network{}
+	r := tx.QueryRow("SELECT NetworkID,Name,Network FROM networks WHERE NetworkID=?", NetworkID)
+	err = r.Scan(&row.NetworkID, &row.Name, &row.Network)
+	return
+}
+
+func Network_GetWhere(
+	tx TX,
+	query string,
+	args ...any,
+) (
+	row *Network,
+	err error,
+) {
+	row = &Network{}
+	r := tx.QueryRow(query, args...)
+	err = r.Scan(&row.NetworkID, &row.Name, &row.Network)
+	return
+}
+
+func Network_Iterate(
+	tx TX,
+	query string,
+	args ...any,
+) iter.Seq2[*Network, error] {
+	rows, err := tx.Query(query, args...)
+	if err != nil {
+		return func(yield func(*Network, error) bool) {
+			yield(nil, err)
+		}
+	}
+
+	return func(yield func(*Network, error) bool) {
+		defer rows.Close()
+		for rows.Next() {
+			row := &Network{}
+			err := rows.Scan(&row.NetworkID, &row.Name, &row.Network)
+			if !yield(row, err) {
+				return
+			}
+		}
+	}
+}
+
+func Network_List(
+	tx TX,
+	query string,
+	args ...any,
+) (
+	l []*Network,
+	err error,
+) {
+	for row, err := range Network_Iterate(tx, query, args...) {
+		if err != nil {
+			return nil, err
+		}
+		l = append(l, row)
+	}
+	return l, nil
+}
+
 // ----------------------------------------------------------------------------
 // Table: peers
 // ----------------------------------------------------------------------------
 
 type Peer struct {
+	NetworkID  int64
 	PeerIP     byte
 	Version    int64
 	APIKey     string
@@ -318,7 +461,7 @@ type Peer struct {
 	PubSignKey []byte
 }
 
-const Peer_SelectQuery = "SELECT PeerIP,Version,APIKey,Name,PublicIP,Port,Relay,PubKey,PubSignKey FROM peers"
+const Peer_SelectQuery = "SELECT NetworkID,PeerIP,Version,APIKey,Name,PublicIP,Port,Relay,PubKey,PubSignKey FROM peers"
 
 func Peer_Insert(
 	tx TX,
@@ -329,7 +472,7 @@ func Peer_Insert(
 		return err
 	}
 
-	_, err = tx.Exec("INSERT INTO peers(PeerIP,Version,APIKey,Name,PublicIP,Port,Relay,PubKey,PubSignKey) VALUES(?,?,?,?,?,?,?,?,?)", row.PeerIP, row.Version, row.APIKey, row.Name, row.PublicIP, row.Port, row.Relay, row.PubKey, row.PubSignKey)
+	_, err = tx.Exec("INSERT INTO peers(NetworkID,PeerIP,Version,APIKey,Name,PublicIP,Port,Relay,PubKey,PubSignKey) VALUES(?,?,?,?,?,?,?,?,?,?)", row.NetworkID, row.PeerIP, row.Version, row.APIKey, row.Name, row.PublicIP, row.Port, row.Relay, row.PubKey, row.PubSignKey)
 	return err
 }
 
@@ -342,7 +485,7 @@ func Peer_Update(
 		return err
 	}
 
-	result, err := tx.Exec("UPDATE peers SET Version=?,Name=?,PublicIP=?,Port=?,Relay=? WHERE PeerIP=?", row.Version, row.Name, row.PublicIP, row.Port, row.Relay, row.PeerIP)
+	result, err := tx.Exec("UPDATE peers SET Version=?,Name=?,PublicIP=?,Port=?,Relay=? WHERE NetworkID=? AND PeerIP=?", row.Version, row.Name, row.PublicIP, row.Port, row.Relay, row.NetworkID, row.PeerIP)
 	if err != nil {
 		return err
 	}
@@ -370,7 +513,7 @@ func Peer_UpdateFull(
 		return err
 	}
 
-	result, err := tx.Exec("UPDATE peers SET Version=?,APIKey=?,Name=?,PublicIP=?,Port=?,Relay=?,PubKey=?,PubSignKey=? WHERE PeerIP=?", row.Version, row.APIKey, row.Name, row.PublicIP, row.Port, row.Relay, row.PubKey, row.PubSignKey, row.PeerIP)
+	result, err := tx.Exec("UPDATE peers SET Version=?,APIKey=?,Name=?,PublicIP=?,Port=?,Relay=?,PubKey=?,PubSignKey=? WHERE NetworkID=? AND PeerIP=?", row.Version, row.APIKey, row.Name, row.PublicIP, row.Port, row.Relay, row.PubKey, row.PubSignKey, row.NetworkID, row.PeerIP)
 	if err != nil {
 		return err
 	}
@@ -391,9 +534,10 @@ func Peer_UpdateFull(
 
 func Peer_Delete(
 	tx TX,
+	NetworkID int64,
 	PeerIP byte,
 ) (err error) {
-	result, err := tx.Exec("DELETE FROM peers WHERE PeerIP=?", PeerIP)
+	result, err := tx.Exec("DELETE FROM peers WHERE NetworkID=? AND PeerIP=?", NetworkID, PeerIP)
 	if err != nil {
 		return err
 	}
@@ -414,14 +558,15 @@ func Peer_Delete(
 
 func Peer_Get(
 	tx TX,
+	NetworkID int64,
 	PeerIP byte,
 ) (
 	row *Peer,
 	err error,
 ) {
 	row = &Peer{}
-	r := tx.QueryRow("SELECT PeerIP,Version,APIKey,Name,PublicIP,Port,Relay,PubKey,PubSignKey FROM peers WHERE PeerIP=?", PeerIP)
-	err = r.Scan(&row.PeerIP, &row.Version, &row.APIKey, &row.Name, &row.PublicIP, &row.Port, &row.Relay, &row.PubKey, &row.PubSignKey)
+	r := tx.QueryRow("SELECT NetworkID,PeerIP,Version,APIKey,Name,PublicIP,Port,Relay,PubKey,PubSignKey FROM peers WHERE NetworkID=? AND PeerIP=?", NetworkID, PeerIP)
+	err = r.Scan(&row.NetworkID, &row.PeerIP, &row.Version, &row.APIKey, &row.Name, &row.PublicIP, &row.Port, &row.Relay, &row.PubKey, &row.PubSignKey)
 	return
 }
 
@@ -435,7 +580,7 @@ func Peer_GetWhere(
 ) {
 	row = &Peer{}
 	r := tx.QueryRow(query, args...)
-	err = r.Scan(&row.PeerIP, &row.Version, &row.APIKey, &row.Name, &row.PublicIP, &row.Port, &row.Relay, &row.PubKey, &row.PubSignKey)
+	err = r.Scan(&row.NetworkID, &row.PeerIP, &row.Version, &row.APIKey, &row.Name, &row.PublicIP, &row.Port, &row.Relay, &row.PubKey, &row.PubSignKey)
 	return
 }
 
@@ -455,7 +600,7 @@ func Peer_Iterate(
 		defer rows.Close()
 		for rows.Next() {
 			row := &Peer{}
-			err := rows.Scan(&row.PeerIP, &row.Version, &row.APIKey, &row.Name, &row.PublicIP, &row.Port, &row.Relay, &row.PubKey, &row.PubSignKey)
+			err := rows.Scan(&row.NetworkID, &row.PeerIP, &row.Version, &row.APIKey, &row.Name, &row.PublicIP, &row.Port, &row.Relay, &row.PubKey, &row.PubSignKey)
 			if !yield(row, err) {
 				return
 			}

hub/api/db/sanitize-validate.go

@@ -3,35 +3,21 @@ package db
 import (
 	"errors"
 	"net/netip"
-	"net/url"
 	"strings"
 )
 
 var (
-	ErrInvalidIP   = errors.New("invalid IP")
-	ErrInvalidPort = errors.New("invalid port")
+	ErrInvalidIP       = errors.New("invalid IP")
+	ErrNonPrivateIP    = errors.New("non-private IP")
+	ErrInvalidPort     = errors.New("invalid port")
+	ErrInvalidNetName  = errors.New("invalid network name")
+	ErrInvalidPeerName = errors.New("invalid peer name")
 )
 
 func Config_Sanitize(c *Config) {
-	if u, err := url.Parse(c.HubAddress); err == nil {
-		c.HubAddress = u.String()
-	}
-
-	if addr, ok := netip.AddrFromSlice(c.VPNNetwork); ok {
-		c.VPNNetwork = addr.AsSlice()
-	}
 }
 
 func Config_Validate(c *Config) error {
-	if _, err := url.Parse(c.HubAddress); err != nil {
-		return err
-	}
-
-	addr, ok := netip.AddrFromSlice(c.VPNNetwork)
-	if !ok || !addr.Is4() || addr.As4()[3] != 0 || addr.As4()[0] == 0 {
-		return ErrInvalidIP
-	}
-
 	return nil
 }
 
@@ -42,6 +28,42 @@ func Session_Validate(s *Session) error {
 	return nil
 }
 
+func Network_Sanitize(n *Network) {
+	n.Name = strings.TrimSpace(n.Name)
+
+	if addr, ok := netip.AddrFromSlice(n.Network); ok {
+		n.Network = addr.AsSlice()
+	}
+}
+
+func Network_Validate(c *Network) error {
+	// 16 bytes is linux limit for network interface names.
+	if len(c.Name) == 0 || len(c.Name) > 16 {
+		return ErrInvalidNetName
+	}
+
+	for _, c := range c.Name {
+		if c >= 'a' && c <= 'z' {
+			continue
+		}
+		if c >= '0' && c <= '9' {
+			continue
+		}
+		return ErrInvalidNetName
+	}
+
+	addr, ok := netip.AddrFromSlice(c.Network)
+	if !ok || !addr.Is4() || addr.As4()[3] != 0 || addr.As4()[0] == 0 {
+		return ErrInvalidIP
+	}
+
+	if !addr.IsPrivate() {
+		return ErrNonPrivateIP
+	}
+
+	return nil
+}
+
 func Peer_Sanitize(p *Peer) {
 	p.Name = strings.TrimSpace(p.Name)
 	if len(p.PublicIP) != 0 {
@@ -65,5 +87,20 @@ func Peer_Validate(p *Peer) error {
 	if p.Port == 0 {
 		return ErrInvalidPort
 	}
+
+	for _, c := range p.Name {
+		if c >= 'a' && c <= 'z' {
+			continue
+		}
+		if c >= '0' && c <= '9' {
+			continue
+		}
+		if c == '.' || c == '-' || c == '_' {
+			continue
+		}
+
+		return ErrInvalidPeerName
+	}
+
 	return nil
 }

hub/api/db/tables.defs

@@ -1,8 +1,6 @@
 TABLE config OF Config (
   ConfigID    int64  PK,
-  HubAddress  string,
-  VPNNetwork  []byte,
-  Password    []byte NoUpdate
+  Password    []byte
 );
 
 TABLE sessions OF Session NoUpdate (
@@ -13,7 +11,14 @@ TABLE sessions OF Session NoUpdate (
   LastSeenAt int64
 );
 
+TABLE networks OF Network (
+  NetworkID int64 PK,
+  Name      string NoUpdate,
+  Network   []byte NoUpdate
+);
+
 TABLE peers OF Peer (
+  NetworkID  int64 PK,
   PeerIP     byte PK,
   Version    int64,
   APIKey     string NoUpdate,

hub/api/db/written.go

@@ -26,16 +26,9 @@ func Session_DeleteBefore(
 	return err
 }
 
-func Config_UpdatePassword(
-	tx TX,
-	pwdHash []byte,
-) (err error) {
-	_, err = tx.Exec("UPDATE config SET Password=? WHERE ConfigID=1", pwdHash)
-	return err
-}
-
-func Peer_ListAll(tx TX) ([]*Peer, error) {
-	return Peer_List(tx, Peer_SelectQuery)
+func Peer_ListAll(tx TX, networkID int64) ([]*Peer, error) {
+	const query = Peer_SelectQuery + ` WHERE NetworkID=? ORDER BY PeerIP ASC`
+	return Peer_List(tx, query, networkID)
 }
 
 func Peer_GetByAPIKey(tx TX, apiKey string) (*Peer, error) {
@@ -45,7 +38,8 @@ func Peer_GetByAPIKey(tx TX, apiKey string) (*Peer, error) {
 		apiKey)
 }
 
-func Peer_Exists(tx TX, ip byte) (exists bool, err error) {
-	err = tx.QueryRow(`SELECT EXISTS(SELECT 1 FROM peers WHERE PeerIP=?)`, ip).Scan(&exists)
+func Peer_Exists(tx TX, networkID int64, ip byte) (exists bool, err error) {
+	const query = `SELECT EXISTS(SELECT 1 FROM peers WHERE NetworkID=? AND PeerIP=?)`
+	err = tx.QueryRow(query, networkID, ip).Scan(&exists)
 	return
 }

hub/api/migrations/2024-11-30-init.sql

@@ -1,7 +1,5 @@
 CREATE TABLE config (
   ConfigID    INTEGER NOT NULL PRIMARY KEY, -- Always 1.
-  HubAddress  TEXT    NOT NULL, -- https://for.example.com
-  VPNNetwork  BLOB    NOT NULL, -- Network (/24), example 10.51.50.0
   Password    BLOB    NOT NULL  -- bcrypt password for web interface
 ) WITHOUT ROWID;
 
@@ -15,13 +13,22 @@ CREATE TABLE sessions (
 
 CREATE INDEX sessions_last_seen_index ON sessions(LastSeenAt);
 
+CREATE TABLE networks (
+  NetworkID   INTEGER NOT NULL PRIMARY KEY,
+  Name        TEXT    NOT NULL UNIQUE, -- Network/interface name.
+  Network     BLOB    NOT NULL UNIQUE  -- Network (/24), example 10.51.50.0
+) WITHOUT ROWID;
+
 CREATE TABLE peers (
-  PeerIP     INTEGER NOT NULL PRIMARY KEY, -- Final byte.
-  Version    INTEGER NOT NULL,
-  APIKey     TEXT    NOT NULL UNIQUE,
+  NetworkID  INTEGER NOT NULL,
+  PeerIP     INTEGER NOT NULL,             -- Final byte of IP.
+  Version    INTEGER NOT NULL,             -- Changes when updated.
+  APIKey     TEXT    NOT NULL UNIQUE,      -- Peer's secret API key.
   Name       TEXT    NOT NULL UNIQUE,      -- For humans.
   PublicIP   BLOB    NOT NULL,
   Port       INTEGER NOT NULL,
   Relay      INTEGER NOT NULL DEFAULT 0,   -- Boolean if peer will forward packets. Must also have public address.
-  PubKey     BLOB    NOT NULL
+  PubKey     BLOB    NOT NULL,
+  PubSignKey BLOB    NOT NULL,
+  PRIMARY KEY(NetworkID, PeerIP)
 ) WITHOUT ROWID;

hub/api/migrations/2024-12-27-signing-keys.sql

@@ -1 +0,0 @@
-ALTER TABLE peers ADD COLUMN PubSignKey BLOB NOT NULL DEFAULT '';

hub/api/types.go

@@ -4,4 +4,5 @@ import "vppn/hub/api/db"
 
 type Config = db.Config
 type Session = db.Session
+type Network = db.Network
 type Peer = db.Peer

hub/app.go

@@ -7,7 +7,7 @@ import (
 	"path/filepath"
 	"vppn/hub/api"
 
-	"git.crumpington.com/lib/webutil"
+	"git.crumpington.com/lib/go/webutil"
 )
 
 //go:embed static

hub/form.go

@@ -0,0 +1,42 @@
+package hub
+
+import (
+	"net/url"
+	"vppn/hub/api"
+
+	"git.crumpington.com/lib/go/webutil"
+)
+
+func (app *App) formGetNetwork(form url.Values) (*api.Network, error) {
+	var id int64
+	if err := webutil.NewFormScanner(form).Scan("NetworkID", &id).Error(); err != nil {
+		return nil, err
+	}
+
+	return app.api.Network_Get(id)
+}
+
+func (app *App) formGetNetworkPeers(form url.Values) (*api.Network, []*api.Peer, error) {
+	n, err := app.formGetNetwork(form)
+	if err != nil {
+		return nil, nil, err
+	}
+
+	peers, err := app.api.Peer_List(n.NetworkID)
+	return n, peers, err
+}
+
+func (app *App) formGetPeer(form url.Values) (*api.Network, *api.Peer, error) {
+	net, err := app.formGetNetwork(form)
+	if err != nil {
+		return nil, nil, err
+	}
+
+	var ip byte
+	if err := webutil.NewFormScanner(form).Scan("PeerIP", &ip).Error(); err != nil {
+		return nil, nil, err
+	}
+
+	peer, err := app.api.Peer_Get(net.NetworkID, ip)
+	return net, peer, err
+}

hub/handler.go

@@ -5,7 +5,7 @@ import (
 	"net/http"
 	"vppn/hub/api"
 
-	"git.crumpington.com/lib/webutil"
+	"git.crumpington.com/lib/go/webutil"
 )
 
 type handlerFunc func(s *api.Session, w http.ResponseWriter, r *http.Request) error

hub/handlers.go

@@ -5,8 +5,6 @@ import (
 	"errors"
 	"log"
 	"net/http"
-	"net/netip"
-	"strings"
 	"vppn/hub/api"
 	"vppn/m"
 
@@ -16,7 +14,7 @@ import (
 
 func (a *App) _root(s *api.Session, w http.ResponseWriter, r *http.Request) error {
 	if s.SignedIn {
-		return a.redirect(w, r, "/admin/config/")
+		return a.redirect(w, r, "/admin/network/list/")
 	} else {
 		return a.redirect(w, r, "/sign-in/")
 	}
@@ -54,54 +52,198 @@ func (a *App) _adminSignOutSubmit(s *api.Session, w http.ResponseWriter, r *http
 	return a.redirect(w, r, "/")
 }
 
-func (a *App) _adminConfig(s *api.Session, w http.ResponseWriter, r *http.Request) error {
-	peers, err := a.api.Peer_List()
+func (a *App) _adminNetworkList(s *api.Session, w http.ResponseWriter, r *http.Request) error {
+	l, err := a.api.Network_List()
 	if err != nil {
 		return err
 	}
-
-	return a.render("/admin-config.html", w, struct {
-		Session *api.Session
-		Peers   []*api.Peer
-		Config  *api.Config
-	}{
-		s,
-		peers,
-		a.api.Config_Get(),
-	})
+	return a.render("/admin-network-list.html", w, struct {
+		Session  *api.Session
+		Networks []*api.Network
+	}{s, l})
 }
 
-func (a *App) _adminConfigEdit(s *api.Session, w http.ResponseWriter, r *http.Request) error {
-	return a.render("/admin-config-edit.html", w, struct {
-		Session *api.Session
-		Config  *api.Config
-	}{
-		s,
-		a.api.Config_Get(),
-	})
+func (a *App) _adminNetworkCreate(s *api.Session, w http.ResponseWriter, r *http.Request) error {
+	return a.render("/admin-network-create.html", w, struct{ Session *api.Session }{s})
 }
 
-func (a *App) _adminConfigEditSubmit(s *api.Session, w http.ResponseWriter, r *http.Request) error {
-	var (
-		conf  = a.api.Config_Get()
-		ipStr string
-	)
+func (a *App) _adminNetworkCreateSubmit(s *api.Session, w http.ResponseWriter, r *http.Request) error {
+	n := &api.Network{}
+	var netStr string
 
 	err := webutil.NewFormScanner(r.Form).
-		Scan("HubAddress", &conf.HubAddress).
-		Scan("VPNNetwork", &ipStr).
+		Scan("Name", &n.Name).
+		Scan("Network", &netStr).
 		Error()
 	if err != nil {
 		return err
 	}
 
-	if conf.VPNNetwork, err = stringToIP(ipStr); err != nil {
+	n.Network, err = stringToIP(netStr)
+	if err != nil {
 		return err
 	}
-	if err := a.api.Config_Update(conf); err != nil {
+
+	if err := a.api.Network_Create(n); err != nil {
 		return err
 	}
-	return a.redirect(w, r, "/admin/config/")
+
+	return a.redirect(w, r, "/admin/network/view/?NetworkID=%d", n.NetworkID)
+}
+
+func (a *App) _adminNetworkView(s *api.Session, w http.ResponseWriter, r *http.Request) error {
+	n, peers, err := a.formGetNetworkPeers(r.Form)
+	if err != nil {
+		return err
+	}
+
+	return a.render("/network/network-view.html", w, struct {
+		Session *api.Session
+		Network *api.Network
+		Peers   []*api.Peer
+	}{s, n, peers})
+}
+
+func (a *App) _adminNetworkDelete(s *api.Session, w http.ResponseWriter, r *http.Request) error {
+	n, peers, err := a.formGetNetworkPeers(r.Form)
+	if err != nil {
+		return err
+	}
+
+	return a.render("/network/network-delete.html", w, struct {
+		Session *api.Session
+		Network *api.Network
+		Peers   []*api.Peer
+	}{s, n, peers})
+}
+
+func (a *App) _adminNetworkDeleteSubmit(s *api.Session, w http.ResponseWriter, r *http.Request) error {
+	n, err := a.formGetNetwork(r.Form)
+	if err != nil {
+		return err
+	}
+
+	if err = a.api.Network_Delete(n); err != nil {
+		return err
+	}
+	return a.redirect(w, r, "/admin/network/list/")
+}
+
+func (a *App) _adminPeerCreate(s *api.Session, w http.ResponseWriter, r *http.Request) error {
+	n, err := a.formGetNetwork(r.Form)
+	if err != nil {
+		return err
+	}
+
+	return a.render("/network/peer-create.html", w, struct {
+		Session *api.Session
+		Network *api.Network
+	}{s, n})
+}
+
+func (a *App) _adminPeerCreateSubmit(s *api.Session, w http.ResponseWriter, r *http.Request) error {
+	var ipStr string
+
+	p := &api.Peer{}
+	err := webutil.NewFormScanner(r.Form).
+		Scan("NetworkID", &p.NetworkID).
+		Scan("IP", &p.PeerIP).
+		Scan("Name", &p.Name).
+		Scan("PublicIP", &ipStr).
+		Scan("Port", &p.Port).
+		Scan("Relay", &p.Relay).
+		Error()
+	if err != nil {
+		return err
+	}
+
+	if p.PublicIP, err = stringToIP(ipStr); err != nil {
+		return err
+	}
+
+	if err := a.api.Peer_CreateNew(p); err != nil {
+		return err
+	}
+	return a.redirect(w, r, "/admin/peer/view/?NetworkID=%d&PeerIP=%d", p.NetworkID, p.PeerIP)
+}
+
+func (a *App) _adminPeerView(s *api.Session, w http.ResponseWriter, r *http.Request) error {
+	net, peer, err := a.formGetPeer(r.Form)
+	if err != nil {
+		return err
+	}
+
+	return a.render("/network/peer-view.html", w, struct {
+		Session *api.Session
+		Network *api.Network
+		Peer    *api.Peer
+	}{s, net, peer})
+}
+
+func (a *App) _adminPeerEdit(s *api.Session, w http.ResponseWriter, r *http.Request) error {
+	net, peer, err := a.formGetPeer(r.Form)
+	if err != nil {
+		return err
+	}
+
+	return a.render("/network/peer-edit.html", w, struct {
+		Session *api.Session
+		Network *api.Network
+		Peer    *api.Peer
+	}{s, net, peer})
+}
+
+func (a *App) _adminPeerEditSubmit(s *api.Session, w http.ResponseWriter, r *http.Request) error {
+	_, peer, err := a.formGetPeer(r.Form)
+	if err != nil {
+		return err
+	}
+
+	var ipStr string
+
+	err = webutil.NewFormScanner(r.Form).
+		Scan("Name", &peer.Name).
+		Scan("PublicIP", &ipStr).
+		Scan("Port", &peer.Port).
+		Scan("Relay", &peer.Relay).
+		Error()
+	if err != nil {
+		return err
+	}
+
+	if peer.PublicIP, err = stringToIP(ipStr); err != nil {
+		return err
+	}
+
+	if err = a.api.Peer_Update(peer); err != nil {
+		return err
+	}
+
+	return a.redirect(w, r, "/admin/peer/view/?NetworkID=%d&PeerIP=%d", peer.NetworkID, peer.PeerIP)
+}
+
+func (a *App) _adminPeerDelete(s *api.Session, w http.ResponseWriter, r *http.Request) error {
+	n, peer, err := a.formGetPeer(r.Form)
+	if err != nil {
+		return err
+	}
+
+	return a.render("/network/peer-delete.html", w, struct {
+		Session *api.Session
+		Network *api.Network
+		Peer    *api.Peer
+	}{s, n, peer})
+}
+
+func (a *App) _adminPeerDeleteSubmit(s *api.Session, w http.ResponseWriter, r *http.Request) error {
+	n, peer, err := a.formGetPeer(r.Form)
+	if err != nil {
+		return err
+	}
+	if err := a.api.Peer_Delete(n.NetworkID, peer.PeerIP); err != nil {
+		return err
+	}
+	return a.redirect(w, r, "/admin/network/view/?NetworkID=%d", n.NetworkID)
 }
 
 func (a *App) _adminPasswordEdit(s *api.Session, w http.ResponseWriter, r *http.Request) error {
@@ -143,194 +285,61 @@ func (a *App) _adminPasswordSubmit(s *api.Session, w http.ResponseWriter, r *htt
 		return err
 	}
 
-	if err := a.api.Config_UpdatePassword(hash); err != nil {
+	conf.Password = hash
+
+	if err := a.api.Config_Update(conf); err != nil {
 		return err
 	}
 
 	return a.redirect(w, r, "/admin/config/")
 }
 
-func (a *App) _adminHosts(s *api.Session, w http.ResponseWriter, r *http.Request) error {
-	conf := a.api.Config_Get()
-
-	peers, err := a.api.Peer_List()
-	if err != nil {
-		return err
-	}
-
-	b := strings.Builder{}
-
-	for _, peer := range peers {
-		ip := conf.VPNNetwork
-		ip[3] = peer.PeerIP
-		b.WriteString(netip.AddrFrom4([4]byte(ip)).String())
-		b.WriteString(" ")
-		b.WriteString(peer.Name)
-		b.WriteString("\n")
-	}
-
-	w.Write([]byte(b.String()))
-	return nil
-}
-
-func (a *App) _adminPeerCreate(s *api.Session, w http.ResponseWriter, r *http.Request) error {
-	return a.render("/admin-peer-create.html", w, struct{ Session *api.Session }{s})
-}
-
-func (a *App) _adminPeerCreateSubmit(s *api.Session, w http.ResponseWriter, r *http.Request) error {
-	var ipStr string
-
-	p := &api.Peer{}
-	err := webutil.NewFormScanner(r.Form).
-		Scan("IP", &p.PeerIP).
-		Scan("Name", &p.Name).
-		Scan("PublicIP", &ipStr).
-		Scan("Port", &p.Port).
-		Scan("Relay", &p.Relay).
-		Error()
-	if err != nil {
-		return err
-	}
-
-	if p.PublicIP, err = stringToIP(ipStr); err != nil {
-		return err
-	}
-
-	if err := a.api.Peer_CreateNew(p); err != nil {
-		return err
-	}
-	return a.redirect(w, r, "/admin/peer/view/?PeerIP=%d", p.PeerIP)
-}
-
-func (a *App) _adminPeerView(s *api.Session, w http.ResponseWriter, r *http.Request) error {
-	var peerIP byte
-	err := webutil.NewFormScanner(r.Form).Scan("PeerIP", &peerIP).Error()
-	if err != nil {
-		return err
-	}
-
-	peer, err := a.api.Peer_Get(peerIP)
-	if err != nil {
-		return err
-	}
-
-	return a.render("/admin-peer-view.html", w, struct {
-		Session *api.Session
-		Peer    *api.Peer
-	}{s, peer})
-}
-
-func (a *App) _adminPeerEdit(s *api.Session, w http.ResponseWriter, r *http.Request) error {
-	var peerIP byte
-	err := webutil.NewFormScanner(r.Form).Scan("PeerIP", &peerIP).Error()
-	if err != nil {
-		return err
-	}
-
-	peer, err := a.api.Peer_Get(peerIP)
-	if err != nil {
-		return err
-	}
-
-	return a.render("/admin-peer-edit.html", w, struct {
-		Session *api.Session
-		Peer    *api.Peer
-	}{s, peer})
-}
-
-func (a *App) _adminPeerEditSubmit(s *api.Session, w http.ResponseWriter, r *http.Request) error {
-	var (
-		peerIP byte
-		ipStr  string
-	)
-
-	err := webutil.NewFormScanner(r.Form).Scan("PeerIP", &peerIP).Error()
-	if err != nil {
-		return err
-	}
-
-	peer, err := a.api.Peer_Get(peerIP)
-	if err != nil {
-		return err
-	}
-	err = webutil.NewFormScanner(r.Form).
-		Scan("Name", &peer.Name).
-		Scan("PublicIP", &ipStr).
-		Scan("Port", &peer.Port).
-		Scan("Relay", &peer.Relay).
-		Error()
-	if err != nil {
-		return err
-	}
-
-	if peer.PublicIP, err = stringToIP(ipStr); err != nil {
-		return err
-	}
-
-	if err = a.api.Peer_Update(peer); err != nil {
-		return err
-	}
-
-	return a.redirect(w, r, "/admin/peer/view/?PeerIP=%d", peer.PeerIP)
-}
-
-func (a *App) _adminPeerDelete(s *api.Session, w http.ResponseWriter, r *http.Request) error {
-	var peerIP byte
-	err := webutil.NewFormScanner(r.Form).Scan("PeerIP", &peerIP).Error()
-	if err != nil {
-		return err
-	}
-
-	peer, err := a.api.Peer_Get(peerIP)
-	if err != nil {
-		return err
-	}
-
-	return a.render("/admin-peer-delete.html", w, struct {
-		Session *api.Session
-		Peer    *api.Peer
-	}{s, peer})
-}
-
-func (a *App) _adminPeerDeleteSubmit(s *api.Session, w http.ResponseWriter, r *http.Request) error {
-	var peerIP byte
-	err := webutil.NewFormScanner(r.Form).Scan("PeerIP", &peerIP).Error()
-	if err != nil {
-		return err
-	}
-
-	if err := a.api.Peer_Delete(peerIP); err != nil {
-		return err
-	}
-
-	return a.redirect(w, r, "/admin/peer/list/")
-}
-
 func (a *App) _peerInit(peer *api.Peer, w http.ResponseWriter, r *http.Request) error {
 	args := m.PeerInitArgs{}
 	if err := json.NewDecoder(r.Body).Decode(&args); err != nil {
 		return err
 	}
 
-	conf, err := a.api.Peer_Init(peer, args)
+	net, err := a.api.Network_Get(peer.NetworkID)
 	if err != nil {
 		return err
 	}
 
-	return a.sendJSON(w, conf)
+	if err := a.api.Peer_Init(peer, args); err != nil {
+		return err
+	}
+
+	resp := m.PeerInitResp{
+		PeerIP:  peer.PeerIP,
+		Network: net.Network,
+	}
+
+	resp.NetworkState.Peers, err = a.peersArray(net.NetworkID)
+	if err != nil {
+		return err
+	}
+
+	return a.sendJSON(w, resp)
 }
 
 func (a *App) _peerFetchState(peer *api.Peer, w http.ResponseWriter, r *http.Request) error {
-	peers, err := a.api.Peer_List()
+
+	peers, err := a.peersArray(peer.NetworkID)
 	if err != nil {
 		return err
 	}
+	return a.sendJSON(w, m.NetworkState{Peers: peers})
+}
 
-	state := m.NetworkState{}
+func (a *App) peersArray(networkID int64) (peers [256]*m.Peer, err error) {
+	l, err := a.api.Peer_List(networkID)
+	if err != nil {
+		return peers, err
+	}
 
-	for _, p := range peers {
+	for _, p := range l {
 		if len(p.PubKey) != 0 {
-			state.Peers[p.PeerIP] = &m.Peer{
+			peers[p.PeerIP] = &m.Peer{
 				PeerIP:     p.PeerIP,
 				Version:    p.Version,
 				Name:       p.Name,
@@ -343,5 +352,5 @@ func (a *App) _peerFetchState(peer *api.Peer, w http.ResponseWriter, r *http.Req
 		}
 	}
 
-	return a.sendJSON(w, state)
+	return
 }

hub/main.go

@@ -6,7 +6,7 @@ import (
 	"net/http"
 	"os"
 
-	"git.crumpington.com/lib/webutil"
+	"git.crumpington.com/lib/go/webutil"
 )
 
 func Main() {

hub/routes.go

@@ -9,14 +9,16 @@ func (a *App) registerRoutes() {
 	a.handleNotSignedIn("GET  /sign-in/", a._signin)
 	a.handleNotSignedIn("POST /sign-in/", a._signinSubmit)
 
-	a.handleSignedIn("GET  /admin/config/", a._adminConfig)
-	a.handleSignedIn("GET  /admin/config/edit/", a._adminConfigEdit)
-	a.handleSignedIn("POST /admin/config/edit/", a._adminConfigEditSubmit)
 	a.handleSignedIn("GET  /admin/sign-out/", a._adminSignOut)
 	a.handleSignedIn("POST /admin/sign-out/", a._adminSignOutSubmit)
-	a.handleSignedIn("GET  /admin/password/edit/", a._adminPasswordEdit)
-	a.handleSignedIn("POST /admin/password/edit/", a._adminPasswordSubmit)
-	a.handleSignedIn("GET  /admin/peer/hosts/", a._adminHosts)
+
+	a.handleSignedIn("GET  /admin/network/list/", a._adminNetworkList)
+	a.handleSignedIn("GET  /admin/network/create/", a._adminNetworkCreate)
+	a.handleSignedIn("POST /admin/network/create/", a._adminNetworkCreateSubmit)
+	a.handleSignedIn("GET  /admin/network/delete/", a._adminNetworkDelete)
+	a.handleSignedIn("POST /admin/network/delete/", a._adminNetworkDeleteSubmit)
+
+	a.handleSignedIn("GET  /admin/network/view/", a._adminNetworkView)
 	a.handleSignedIn("GET  /admin/peer/create/", a._adminPeerCreate)
 	a.handleSignedIn("POST /admin/peer/create/", a._adminPeerCreateSubmit)
 	a.handleSignedIn("GET  /admin/peer/view/", a._adminPeerView)
@@ -25,6 +27,9 @@ func (a *App) registerRoutes() {
 	a.handleSignedIn("GET  /admin/peer/delete/", a._adminPeerDelete)
 	a.handleSignedIn("POST /admin/peer/delete/", a._adminPeerDeleteSubmit)
 
+	a.handleSignedIn("GET  /admin/password/edit/", a._adminPasswordEdit)
+	a.handleSignedIn("POST /admin/password/edit/", a._adminPasswordSubmit)
+
 	a.handlePeer("POST /peer/init/", a._peerInit)
 	a.handlePeer("GET /peer/fetch-state/", a._peerFetchState)
 }

hub/static/custom.css

@@ -1,7 +1,3 @@
-body {
-    max-width: 1920px;
-}
-
 .def-list tr td:first-child {
     text-align:right;
     width:1%;

hub/templates/admin-config-edit.html

@@ -1,20 +0,0 @@
-{{define "body" -}}
-<h2>Config</h2>
-
-<form method="POST">
-  <input type="hidden" name="CSRF" value="{{.Session.CSRF}}">
-  <p>
-    <label>Hub Address</label><br>
-    <input type="url" name="HubAddress" value="{{.Config.HubAddress}}">
-  </p>
-  <p>
-    <label>VPN Network</label><br>
-    <input type="text" name="VPNNetwork" value="{{ipToString .Config.VPNNetwork}}">
-  </p>
-  <p>
-    <button type="submit">Save</button>
-    <a href="/admin/config/">Cancel</a>
-  </p>
-</form>
-
-{{- end}}

hub/templates/admin-network-create.html

@@ -0,0 +1,19 @@
+{{define "body" -}}
+<h2>Create Network</h2>
+
+<form method="POST">
+  <input type="hidden" name="CSRF" value="{{.Session.CSRF}}">
+  <p>
+    <label>Name</label><br>
+    <input type="text" name="Name">
+  </p>
+  <p>
+    <label>Network /24</label><br>
+    <input type="text" name="Network">
+  </p>
+  <p>
+    <button type="submit">Save</button>
+    <a href="/admin/network/list/">Cancel</a>
+  </p>
+</form>
+{{- end}}

hub/templates/admin-network-list.html

@@ -0,0 +1,38 @@
+{{define "body" -}}
+<h2>Networks</h2>
+
+<p>
+  <a href="/admin/network/create/">Create</a>
+</p>
+
+{{if .Networks -}}
+<table>
+  <thead>
+    <tr>
+      <th>Name</th>
+      <th>Network</th>
+    </tr>
+  </thead>
+  <tbody>
+  {{range .Networks -}}
+  <tr>
+    <td>
+      <a href="/admin/network/view/?NetworkID={{.NetworkID}}">
+        {{.Name}}
+      </a>
+    </td>
+    <td>{{ipToString .Network}}</td>
+  </tr>
+  </tbody>
+  {{- end}}
+</table>
+{{- else}}
+<p>No networks.</p>
+{{- end}}
+
+<h3>Settings</h3>
+
+<ul>
+  <li><a href="/admin/password/edit/">Password</a></li>
+</ul>
+{{- end}}

hub/templates/admin-peer-delete.html

@@ -1,36 +0,0 @@
-{{define "body" -}}
-<h2>Delete Peer</h2>
-
-{{with .Peer -}}
-<form method="POST">
-  <input type="hidden" name="CSRF" value="{{$.Session.CSRF}}">
-  <p>
-    <label>Peer IP</label><br>
-    <input type="number" name="PeerIP" value="{{.PeerIP}}" disabled>
-  </p>
-  <p>
-    <label>Name</label><br>
-    <input type="text" value="{{.Name}}" disabled>
-  </p>
-  <p>
-    <label>Public IP</label><br>
-    <input type="text" value="{{ipToString .PublicIP}}" disabled>
-  </p>
-  <p>
-    <label>Port</label><br>
-    <input type="number" value="{{.Port}}" disabled>
-  </p>
-  <p>
-    <label>
-      <input type="checkbox" {{if .Relay}}checked{{end}} disabled>
-      Relay
-    </label>
-  </p>
-  <p>
-    <button type="submit">Delete</button>
-    <a href="/admin/peer/view/?PeerIP={{.PeerIP}}">Cancel</a>
-  </p>
-</form>
-{{- end}}
-
-{{- end}}

hub/templates/admin-peer-init.html

@@ -1,13 +0,0 @@
-{{define "body" -}}
-<h2>Initialize Peer</h2>
-
-<p>
-  Configure the peer with the following URL:
-</p>
-<pre>
-  {{.HubAddress}}/peer/init/?Code={{.Code}}
-</pre>
-<p>
-  <a href="/admin/config/">Done</a>
-</p>
-{{- end}}

hub/templates/admin-peer-intent.html

@@ -1,13 +0,0 @@
-{{define "body" -}}
-<h2>Create Peer</h2>
-
-<p>
-  Configure the peer with the following URL:
-</p>
-<pre>
-  {{.HubAddress}}/peer/create/?Code={{.Code}}
-</pre>
-<p>
-  <a href="/admin/config/">Done</a>
-</p>
-{{- end}}

hub/templates/admin-sign-out.html

@@ -5,7 +5,7 @@
   <input type="hidden" name="CSRF" value="{{.Session.CSRF}}">
   <p>
     <button type="submit">Sign Out</button>
-    <a href="/admin/config/">Cancel</a>
+    <a href="/">Cancel</a>
   </p>
 </form>
 {{- end}}

hub/templates/base.html

@@ -10,7 +10,7 @@
     <h1>VPPN</h1>
     <nav>
       {{if .Session.SignedIn -}}
-      <a href="/admin/config/">Home</a> /
+      <a href="/admin/networks/list/">Home</a> /
       <a href="/admin/sign-out/">Sign out</a>
       {{- end}}
     </nav>

hub/templates/network/base.html

@@ -0,0 +1,25 @@
+<!DOCTYPE html>
+<html lang="en">
+<head>
+  <title>VPPN Hub</title>
+  <link rel="stylesheet" href="/static/new.min.css">
+    <link rel="stylesheet" href="/static/custom.css">
+</head>
+<body>
+  <header>
+    <h1>VPPN</h1>
+    <nav>
+      {{if .Session.SignedIn -}}
+      <a href="/admin/networks/list/">Home</a> /
+      <a href="/admin/sign-out/">Sign out</a>
+      {{- end}}
+    </nav>
+  </header>
+  <h2>
+    Network:
+    <a href="/admin/network/view/?NetworkID={{.Network.NetworkID}}">{{.Network.Name}}</a>
+  </h2>
+
+  {{block "body" .}}There's nothing here.{{end}}
+</body>
+</html>

hub/templates/network/network-delete.html

@@ -0,0 +1,16 @@
+{{define "body" -}}
+<h3>Delete</h3>
+
+{{if .Peers -}}
+<p>You must first delete all peers.</p>
+{{- else -}}
+<form method="POST">
+  <input type="hidden" name="CSRF" value="{{.Session.CSRF}}">
+  <input type="hidden" name="NetworkID" value="{{.Network.NetworkID}}">
+  <p>
+    <button type="submit">Delete</button>
+    <a href="/admin/network/view/?NetworkID={{.Network.NetworkID}}">Cancel</a>
+  </p>
+</form>
+{{- end}}
+{{- end}}

hub/templates/network/network-view.html

@@ -1,27 +1,19 @@
 {{define "body" -}}
-<h2>Config</h2>
-
 <p>
-  <a href="/admin/config/edit/">Edit</a> /
-  <a href="/admin/password/edit/">Change Password</a>
+  <a href="/admin/network/delete/?NetworkID={{.Network.NetworkID}}">Delete</a>
 </p>
 
 <table class="def-list">
   <tr>
-    <td>Hub Address</td>
-    <td>{{.Config.HubAddress}}</td>
-  </tr>
-  <tr>
-    <td>VPN Network</td>
-    <td>{{ipToString .Config.VPNNetwork}}</td>
+    <td>Network</td>
+    <td>{{ipToString .Network.Network}}/24</td>
   </tr>
 </table>
 
-<h2>Peers</h2>
+<h3>Peers</h3>
 
 <p>
-  <a href="/admin/peer/create/">Add Peer</a> /
-  <a href="/admin/peer/hosts/">Hosts</a>
+  <a href="/admin/peer/create/?NetworkID={{.Network.NetworkID}}">Create</a>
 </p>
 
 {{if .Peers -}}
@@ -39,7 +31,7 @@
   {{range .Peers -}}
   <tr>
     <td>
-      <a href="/admin/peer/view/?PeerIP={{.PeerIP}}">
+      <a href="/admin/peer/view/?NetworkID={{$.Network.NetworkID}}&PeerIP={{.PeerIP}}">
         {{.PeerIP}}
       </a>
     </td>

hub/templates/network/peer-create.html

@@ -1,8 +1,9 @@
 {{define "body" -}}
-<h2>New Peer</h2>
+<h3>New Peer</h3>
 
 <form method="POST">
   <input type="hidden" name="CSRF" value="{{.Session.CSRF}}">
+  <input type="hidden" name="NetworkID" value="{{.Network.NetworkID}}">
   <p>
     <label>IP</label><br>
     <input type="number" name="IP" min="1" max="255" value="0">
@@ -27,7 +28,7 @@
   </p>
   <p>
     <button type="submit">Save</button>
-    <a href="/admin/config/">Cancel</a>
+    <a href="/admin/network/view/?NetworkID={{.Network.NetworkID}}">Cancel</a>
   </p>
 </form>
 

hub/templates/network/peer-delete.html

@@ -0,0 +1,15 @@
+{{define "body" -}}
+<h3>Delete {{.Peer.Name}}</h3>
+
+{{with .Peer -}}
+<form method="POST">
+  <input type="hidden" name="CSRF" value="{{$.Session.CSRF}}">
+  <input type="hidden" name="NetworkID" value="{{.NetworkID}}">
+  <input type="hidden" name="NetworkID" value="{{.PeerIP}}">
+  <p>
+    <button type="submit">Delete</button>
+    <a href="/admin/peer/view/?PeerIP={{.PeerIP}}&NetworkID={{.NetworkID}}">Cancel</a>
+  </p>
+</form>
+{{- end}}
+{{- end}}

hub/templates/network/peer-edit.html

@@ -6,7 +6,7 @@
   <input type="hidden" name="CSRF" value="{{$.Session.CSRF}}">
   <p>
     <label>Peer IP</label><br>
-    <input type="number" name="PeerIP" value="{{.PeerIP}}" disabled>
+    <input type="text" value="{{.PeerIP}}" disabled>
   </p>
   <p>
     <label>Name</label><br>
@@ -28,9 +28,8 @@
   </p>
   <p>
     <button type="submit">Save</button>
-    <a href="/admin/peer/view/?PeerIP={{.PeerIP}}">Cancel</a>
+    <a href="/admin/peer/view/?NetworkID={{$.Network.NetworkID}}&PeerIP={{.PeerIP}}">Cancel</a>
   </p>
 </form>
 {{- end}}
-
 {{- end}}

hub/templates/network/peer-view.html

@@ -1,21 +1,25 @@
 {{define "body" -}}
-<h2>Peer</h2>
-
+<h3>{{.Peer.Name}}</h3>
 <p>
-  <a href="/admin/peer/edit/?PeerIP={{.Peer.PeerIP}}">Edit</a> /
-  <a href="/admin/peer/init/?PeerIP={{.Peer.PeerIP}}">Initialize</a> /
-  <a href="/admin/peer/delete/?PeerIP={{.Peer.PeerIP}}">Delete</a>
+  <a href="/admin/peer/edit/?NetworkID={{.Network.NetworkID}}&PeerIP={{.Peer.PeerIP}}">Edit</a> /
+  <a href="/admin/peer/delete/?NetworkID={{.Network.NetworkID}}&PeerIP={{.Peer.PeerIP}}">Delete</a>
 </p>
 
 {{with .Peer -}}
 <table class="def-list">
   <tr><td>Peer IP</td><td>{{.PeerIP}}</td></tr>
-  <tr><td>Name</td><td>{{.Name}}</td></tr>
   <tr><td>Public IP</td><td>{{ipToString .PublicIP}}</td></tr>
   <tr><td>Port</td><td>{{.Port}}</td></tr>
   <tr><td>Relay</td><td>{{if .Relay}}T{{else}}F{{end}}</td></tr>
-  <tr><td>API Key</td><td>{{.APIKey}}</td></tr>
+</td></tr>
 </table>
+
+<details>
+  <summary>API Key</summary>
+  <p>{{.APIKey}}</p>
+</details>
+
+
 {{- end}}
 
 {{- end}}

m/models.go

@@ -6,12 +6,10 @@ type PeerInitArgs struct {
 	PubSignKey []byte
 }
 
-type PeerConfig struct {
-	PeerIP   byte
-	Network  []byte
-	PublicIP []byte
-	Port     uint16
-	Relay    bool
+type PeerInitResp struct {
+	PeerIP       byte
+	Network      []byte
+	NetworkState NetworkState
 }
 
 type Peer struct {

node/addrdiscovery.go

@@ -1,67 +0,0 @@
-package node
-
-import (
-	"log"
-	"net/netip"
-	"time"
-)
-
-func addrDiscoveryServer() {
-	var (
-		buf1 = make([]byte, bufferSize)
-		buf2 = make([]byte, bufferSize)
-	)
-
-	for {
-		msg := <-discoveryMessages
-		p := msg.Packet
-
-		route := routingTable[msg.SrcIP].Load()
-		if route == nil || !route.RemoteAddr.IsValid() {
-			continue
-		}
-
-		_sendControlPacket(addrDiscoveryPacket{
-			TraceID: p.TraceID,
-			ToAddr:  msg.SrcAddr,
-		}, *route, buf1, buf2)
-	}
-}
-
-func addrDiscoveryClient() {
-	var (
-		checkInterval = 8 * time.Second
-		timer         = time.NewTimer(4 * time.Second)
-
-		buf1 = make([]byte, bufferSize)
-		buf2 = make([]byte, bufferSize)
-
-		addrPacket addrDiscoveryPacket
-		lAddr      netip.AddrPort
-	)
-
-	for {
-		select {
-		case msg := <-discoveryMessages:
-			p := msg.Packet
-			if p.TraceID != addrPacket.TraceID || !p.ToAddr.IsValid() || p.ToAddr == lAddr {
-				continue
-			}
-
-			log.Printf("Discovered local address: %v", p.ToAddr)
-			lAddr = p.ToAddr
-			localAddr.Store(&p.ToAddr)
-
-		case <-timer.C:
-			timer.Reset(checkInterval)
-
-			route := getRelayRoute()
-			if route == nil {
-				continue
-			}
-
-			addrPacket.TraceID = newTraceID()
-			_sendControlPacket(addrPacket, *route, buf1, buf2)
-		}
-	}
-}

node/cipher-discovery.go

@@ -1,13 +0,0 @@
-package node
-
-/*
-func signData(privKey *[64]byte, h header, data, out []byte) []byte {
-	out = out[:headerSize]
-	h.Marshal(out)
-	return sign.Sign(out, data, privKey)
-}
-
-func openData(pubKey *[32]byte, signed, out []byte) (data []byte, ok bool) {
-	return sign.Open(out[:0], signed[headerSize:], pubKey)
-}
-*/

node/config.go

@@ -1,11 +0,0 @@
-package node
-
-import "vppn/m"
-
-type localConfig struct {
-	m.PeerConfig
-	PubKey      []byte
-	PrivKey     []byte
-	PubSignKey  []byte
-	PrivSignKey []byte
-}

node/conn.go

@@ -1,50 +0,0 @@
-package node
-
-import (
-	"io"
-	"log"
-	"net"
-	"net/netip"
-	"sync"
-)
-
-// ----------------------------------------------------------------------------
-
-type connWriter struct {
-	lock sync.Mutex
-	conn *net.UDPConn
-}
-
-func newConnWriter(conn *net.UDPConn) *connWriter {
-	return &connWriter{conn: conn}
-}
-
-func (w *connWriter) WriteTo(packet []byte, addr netip.AddrPort) {
-	// Even though a conn is safe for concurrent use, it turns out that a mutex
-	// in Go is more fair when there's contention. Without this lock, control
-	// packets may fail to be sent in a timely manner causing timeouts.
-	w.lock.Lock()
-	if _, err := w.conn.WriteToUDPAddrPort(packet, addr); err != nil {
-		log.Printf("Failed to write to UDP port: %v", err)
-	}
-	w.lock.Unlock()
-}
-
-// ----------------------------------------------------------------------------
-
-type ifWriter struct {
-	lock  sync.Mutex
-	iface io.ReadWriteCloser
-}
-
-func newIFWriter(iface io.ReadWriteCloser) *ifWriter {
-	return &ifWriter{iface: iface}
-}
-
-func (w *ifWriter) Write(packet []byte) {
-	w.lock.Lock()
-	if _, err := w.iface.Write(packet); err != nil {
-		log.Fatalf("Failed to write to interface: %v", err)
-	}
-	w.lock.Unlock()
-}

node/globalfuncs.go

@@ -1,73 +0,0 @@
-package node
-
-import (
-	"net/netip"
-	"sync/atomic"
-)
-
-func getRelayRoute() *peerRoute {
-	if ip := relayIP.Load(); ip != nil {
-		return routingTable[*ip].Load()
-	}
-	return nil
-}
-
-func getLocalAddr() netip.AddrPort {
-	if a := localAddr.Load(); a != nil {
-		return *a
-	}
-	return netip.AddrPort{}
-}
-
-func _sendControlPacket(pkt interface{ Marshal([]byte) []byte }, route peerRoute, buf1, buf2 []byte) {
-	buf := pkt.Marshal(buf2)
-	h := header{
-		StreamID: controlStreamID,
-		Counter:  atomic.AddUint64(&sendCounters[route.IP], 1),
-		SourceIP: localIP,
-		DestIP:   route.IP,
-	}
-	buf = route.ControlCipher.Encrypt(h, buf, buf1)
-
-	if route.Direct {
-		_conn.WriteTo(buf, route.RemoteAddr)
-		return
-	}
-
-	_relayPacket(route.IP, buf, buf2)
-}
-
-func _sendDataPacket(route *peerRoute, pkt, buf1, buf2 []byte) {
-	h := header{
-		StreamID: dataStreamID,
-		Counter:  atomic.AddUint64(&sendCounters[route.IP], 1),
-		SourceIP: localIP,
-		DestIP:   route.IP,
-	}
-
-	enc := route.DataCipher.Encrypt(h, pkt, buf1)
-
-	if route.Direct {
-		_conn.WriteTo(enc, route.RemoteAddr)
-		return
-	}
-
-	_relayPacket(route.IP, enc, buf2)
-}
-
-func _relayPacket(destIP byte, data, buf []byte) {
-	relayRoute := getRelayRoute()
-	if relayRoute == nil || !relayRoute.Up || !relayRoute.Relay {
-		return
-	}
-
-	h := header{
-		StreamID: dataStreamID,
-		Counter:  atomic.AddUint64(&sendCounters[relayRoute.IP], 1),
-		SourceIP: localIP,
-		DestIP:   destIP,
-	}
-
-	enc := relayRoute.DataCipher.Encrypt(h, data, buf)
-	_conn.WriteTo(enc, relayRoute.RemoteAddr)
-}

node/globals.go

@@ -1,87 +0,0 @@
-package node
-
-import (
-	"net"
-	"net/netip"
-	"net/url"
-	"sync/atomic"
-	"time"
-)
-
-const (
-	bufferSize            = 1536
-	if_mtu                = 1200
-	if_queue_len          = 2048
-	controlCipherOverhead = 16
-	dataCipherOverhead    = 16
-	signOverhead          = 64
-)
-
-var (
-	multicastIP   = netip.AddrFrom4([4]byte{224, 0, 0, 157})
-	multicastAddr = net.UDPAddrFromAddrPort(netip.AddrPortFrom(multicastIP, 4560))
-)
-
-type peerRoute struct {
-	IP            byte
-	Up            bool // True if data can be sent on the route.
-	Relay         bool // True if the peer is a relay.
-	Direct        bool // True if this is a direct connection.
-	PubSignKey    []byte
-	ControlCipher *controlCipher
-	DataCipher    *dataCipher
-	RemoteAddr    netip.AddrPort // Remote address if directly connected.
-}
-
-var (
-	hubURL *url.URL
-	apiKey string
-
-	// Configuration for this peer.
-	netName     string
-	localIP     byte
-	localPub    bool
-	privKey     []byte
-	privSignKey []byte
-
-	// Shared interface for writing.
-	_iface *ifWriter
-
-	// Shared connection for writing.
-	_conn *connWriter
-
-	// Counters for sending to each peer.
-	sendCounters [256]uint64 = func() (out [256]uint64) {
-		for i := range out {
-			out[i] = uint64(time.Now().Unix()<<30 + 1)
-		}
-		return
-	}()
-
-	// Duplicate checkers for incoming packets.
-	dupChecks [256]*dupCheck = func() (out [256]*dupCheck) {
-		for i := range out {
-			out[i] = newDupCheck(0)
-		}
-		return
-	}()
-
-	// Messages for the supervisor.
-	messages = make(chan any, 512)
-
-	// Global routing table.
-	routingTable [256]*atomic.Pointer[peerRoute] = func() (out [256]*atomic.Pointer[peerRoute]) {
-		for i := range out {
-			out[i] = &atomic.Pointer[peerRoute]{}
-			out[i].Store(&peerRoute{})
-		}
-		return
-	}()
-
-	// Managed by the addrDiscovery* functions.
-	discoveryMessages = make(chan controlMsg[addrDiscoveryPacket], 256)
-
-	// Managed by the relayManager.
-	localAddr = &atomic.Pointer[netip.AddrPort]{}
-	relayIP   = &atomic.Pointer[byte]{}
-)

node/header.go

@@ -1,35 +0,0 @@
-package node
-
-import "unsafe"
-
-// ----------------------------------------------------------------------------
-
-const (
-	headerSize        = 12
-	controlStreamID   = 2
-	controlHeaderSize = 24
-	dataStreamID      = 1
-	dataHeaderSize    = 12
-)
-
-type header struct {
-	StreamID byte
-	Counter  uint64 // Init with time.Now().Unix << 30 to ensure monotonic.
-	SourceIP byte
-	DestIP   byte
-}
-
-func (h *header) Parse(b []byte) {
-	h.StreamID = b[0]
-	h.Counter = *(*uint64)(unsafe.Pointer(&b[1]))
-	h.SourceIP = b[9]
-	h.DestIP = b[10]
-}
-
-func (h *header) Marshal(buf []byte) {
-	buf[0] = h.StreamID
-	*(*uint64)(unsafe.Pointer(&buf[1])) = h.Counter
-	buf[9] = h.SourceIP
-	buf[10] = h.DestIP
-	buf[11] = 0
-}

node/hubpoller.go

@@ -1,92 +0,0 @@
-package node
-
-import (
-	"encoding/json"
-	"io"
-	"log"
-	"net/http"
-	"time"
-	"vppn/m"
-)
-
-type hubPoller struct {
-	client   *http.Client
-	req      *http.Request
-	versions [256]int64
-}
-
-func newHubPoller() *hubPoller {
-	u := *hubURL
-	u.Path = "/peer/fetch-state/"
-
-	client := &http.Client{Timeout: 8 * time.Second}
-
-	req := &http.Request{
-		Method: http.MethodGet,
-		URL:    &u,
-		Header: http.Header{},
-	}
-	req.SetBasicAuth("", apiKey)
-
-	return &hubPoller{
-		client: client,
-		req:    req,
-	}
-}
-
-func (hp *hubPoller) Run() {
-	defer panicHandler()
-
-	state, err := loadNetworkState(netName)
-	if err != nil {
-		log.Printf("Failed to load network state: %v", err)
-		log.Printf("Polling hub...")
-		hp.pollHub()
-	} else {
-		hp.applyNetworkState(state)
-	}
-
-	for range time.Tick(64 * time.Second) {
-		hp.pollHub()
-	}
-}
-
-func (hp *hubPoller) pollHub() {
-	var state m.NetworkState
-
-	resp, err := hp.client.Do(hp.req)
-	if err != nil {
-		log.Printf("Failed to fetch peer state: %v", err)
-		return
-	}
-	body, err := io.ReadAll(resp.Body)
-	_ = resp.Body.Close()
-	if err != nil {
-		log.Printf("Failed to read body from hub: %v", err)
-		return
-	}
-
-	if err := json.Unmarshal(body, &state); err != nil {
-		log.Printf("Failed to unmarshal response from hub: %v\n%s", err, body)
-		return
-	}
-
-	hp.applyNetworkState(state)
-
-	if err := storeNetworkState(netName, state); err != nil {
-		log.Printf("Failed to store network state: %v", err)
-	}
-}
-
-func (hp *hubPoller) applyNetworkState(state m.NetworkState) {
-	for i, peer := range state.Peers {
-		if i != int(localIP) {
-			if peer == nil || peer.Version != hp.versions[i] {
-				messages <- peerUpdateMsg{PeerIP: byte(i), Peer: state.Peers[i]}
-				if peer != nil {
-					hp.versions[i] = peer.Version
-				}
-			}
-		}
-	}
-}

node/localdiscovery.go

@@ -1,97 +0,0 @@
-package node
-
-import (
-	"log"
-	"net"
-	"time"
-
-	"golang.org/x/crypto/nacl/sign"
-)
-
-func localDiscovery() {
-	conn, err := net.ListenMulticastUDP("udp", nil, multicastAddr)
-	if err != nil {
-		log.Printf("Failed to bind to multicast address: %v", err)
-		return
-	}
-
-	go sendLocalDiscovery(conn)
-	go recvLocalDiscovery(conn)
-}
-
-func sendLocalDiscovery(conn *net.UDPConn) {
-	var (
-		buf1 = make([]byte, bufferSize)
-		buf2 = make([]byte, bufferSize)
-	)
-
-	for range time.Tick(32 * time.Second) {
-		signed := buildLocalDiscoveryPacket(buf1, buf2)
-		if _, err := conn.WriteToUDP(signed, multicastAddr); err != nil {
-			log.Printf("Failed to write multicast UDP packet: %v", err)
-		}
-	}
-}
-
-func recvLocalDiscovery(conn *net.UDPConn) {
-	var (
-		raw = make([]byte, bufferSize)
-		buf = make([]byte, bufferSize)
-	)
-
-	for {
-		n, remoteAddr, err := conn.ReadFromUDPAddrPort(raw[:bufferSize])
-		if err != nil {
-			log.Fatalf("Failed to read from UDP port (multicast): %v", err)
-		}
-
-		raw = raw[:n]
-		h, ok := openLocalDiscoveryPacket(raw, buf)
-		if !ok {
-			log.Printf("Failed to open discovery packet?")
-			continue
-		}
-
-		msg := controlMsg[localDiscoveryPacket]{
-			SrcIP:   h.SourceIP,
-			SrcAddr: remoteAddr,
-			Packet:  localDiscoveryPacket{},
-		}
-
-		select {
-		case messages <- msg:
-		default:
-			log.Printf("Dropping local discovery message.")
-		}
-	}
-}
-
-func buildLocalDiscoveryPacket(buf1, buf2 []byte) []byte {
-	h := header{
-		StreamID: controlStreamID,
-		Counter:  0,
-		SourceIP: localIP,
-		DestIP:   255,
-	}
-	out := buf1[:headerSize]
-	h.Marshal(out)
-	return sign.Sign(buf2[:0], out, (*[64]byte)(privSignKey))
-}
-
-func openLocalDiscoveryPacket(raw, buf []byte) (h header, ok bool) {
-	if len(raw) != headerSize+signOverhead {
-		ok = false
-		return
-	}
-
-	h.Parse(raw[signOverhead:])
-	route := routingTable[h.SourceIP].Load()
-	if route == nil || route.PubSignKey == nil {
-		log.Printf("Missing signing key: %d", h.SourceIP)
-		ok = false
-		return
-	}
-
-	_, ok = sign.Open(buf[:0], raw, (*[32]byte)(route.PubSignKey))
-	return
-}

node/localdiscovery_test.go

@@ -1,35 +0,0 @@
-package node
-
-import (
-	"bytes"
-	"crypto/rand"
-	"testing"
-
-	"golang.org/x/crypto/nacl/sign"
-)
-
-func TestLocalDiscoveryPacketSigning(t *testing.T) {
-	localIP = 32
-
-	var (
-		buf1                      = make([]byte, bufferSize)
-		buf2                      = make([]byte, bufferSize)
-		pubSignKey, privSigKey, _ = sign.GenerateKey(rand.Reader)
-	)
-
-	privSignKey = privSigKey[:]
-	route := routingTable[localIP].Load()
-	route.IP = byte(localIP)
-	route.PubSignKey = pubSignKey[0:32]
-	routingTable[localIP].Store(route)
-
-	out := buildLocalDiscoveryPacket(buf1, buf2)
-
-	h, ok := openLocalDiscoveryPacket(bytes.Clone(out), buf1)
-	if !ok {
-		t.Fatal(h, ok)
-	}
-	if h.StreamID != controlStreamID || h.SourceIP != localIP || h.DestIP != 255 {
-		t.Fatal(h)
-	}
-}

node/main.go

@@ -1,331 +0,0 @@
-package node
-
-import (
-	"bytes"
-	"crypto/rand"
-	"encoding/json"
-	"flag"
-	"fmt"
-	"io"
-	"log"
-	"net"
-	"net/http"
-	"net/netip"
-	"net/url"
-	"os"
-	"runtime/debug"
-	"time"
-	"vppn/m"
-
-	"golang.org/x/crypto/nacl/box"
-	"golang.org/x/crypto/nacl/sign"
-)
-
-func panicHandler() {
-	if r := recover(); r != nil {
-		log.Fatalf("\n %v\n\nstacktrace from panic: %s\n", r, string(debug.Stack()))
-	}
-}
-
-func Main() {
-	defer panicHandler()
-
-	var hubAddress string
-
-	flag.StringVar(&netName, "name", "", "[REQUIRED] The network name.")
-	flag.StringVar(&hubAddress, "hub-address", "", "[REQUIRED] The hub address.")
-	flag.StringVar(&apiKey, "api-key", "", "[REQUIRED] The node's API key.")
-	flag.Parse()
-
-	if netName == "" || hubAddress == "" || apiKey == "" {
-		flag.Usage()
-		os.Exit(1)
-	}
-
-	var err error
-
-	hubURL, err = url.Parse(hubAddress)
-	if err != nil {
-		log.Fatalf("Failed to parse hub address: %v", err)
-	}
-
-	main()
-}
-
-func initPeerWithHub() {
-	encPubKey, encPrivKey, err := box.GenerateKey(rand.Reader)
-	if err != nil {
-		log.Fatalf("Failed to generate encryption keys: %v", err)
-	}
-
-	signPubKey, signPrivKey, err := sign.GenerateKey(rand.Reader)
-	if err != nil {
-		log.Fatalf("Failed to generate signing keys: %v", err)
-	}
-
-	initURL := *hubURL
-	initURL.Path = "/peer/init/"
-
-	args := m.PeerInitArgs{
-		EncPubKey:  encPubKey[:],
-		PubSignKey: signPubKey[:],
-	}
-
-	buf := &bytes.Buffer{}
-	if err := json.NewEncoder(buf).Encode(args); err != nil {
-		log.Fatalf("Failed to encode init args: %v", err)
-	}
-
-	req, err := http.NewRequest(http.MethodPost, initURL.String(), buf)
-	if err != nil {
-		log.Fatalf("Failed to construct request: %v", err)
-	}
-	req.SetBasicAuth("", apiKey)
-
-	resp, err := http.DefaultClient.Do(req)
-	if err != nil {
-		log.Fatalf("Failed to init with hub: %v", err)
-	}
-	defer resp.Body.Close()
-
-	data, err := io.ReadAll(resp.Body)
-	if err != nil {
-		log.Fatalf("Failed to read response body: %v", err)
-	}
-
-	peerConfig := localConfig{}
-	if err := json.Unmarshal(data, &peerConfig.PeerConfig); err != nil {
-		log.Fatalf("Failed to parse configuration: %v\n%s", err, data)
-	}
-
-	peerConfig.PubKey = encPubKey[:]
-	peerConfig.PrivKey = encPrivKey[:]
-	peerConfig.PubSignKey = signPubKey[:]
-	peerConfig.PrivSignKey = signPrivKey[:]
-
-	if err := storePeerConfig(netName, peerConfig); err != nil {
-		log.Fatalf("Failed to store configuration: %v", err)
-	}
-
-	log.Print("Initialization successful.")
-}
-
-// ----------------------------------------------------------------------------
-
-func main() {
-	config, err := loadPeerConfig(netName)
-	if err != nil {
-		log.Printf("Failed to load configuration: %v", err)
-		log.Printf("Initializing...")
-		initPeerWithHub()
-
-		config, err = loadPeerConfig(netName)
-		if err != nil {
-			log.Fatalf("Failed to load configuration: %v", err)
-		}
-	}
-
-	iface, err := openInterface(config.Network, config.PeerIP, netName)
-	if err != nil {
-		log.Fatalf("Failed to open interface: %v", err)
-	}
-
-	myAddr, err := net.ResolveUDPAddr("udp", fmt.Sprintf(":%d", config.Port))
-	if err != nil {
-		log.Fatalf("Failed to resolve UDP address: %v", err)
-	}
-
-	conn, err := net.ListenUDP("udp", myAddr)
-	if err != nil {
-		log.Fatalf("Failed to open UDP port: %v", err)
-	}
-
-	conn.SetReadBuffer(1024 * 1024 * 8)
-	conn.SetWriteBuffer(1024 * 1024 * 8)
-
-	// Intialize globals.
-	_iface = newIFWriter(iface)
-	_conn = newConnWriter(conn)
-
-	localIP = config.PeerIP
-
-	ip, ok := netip.AddrFromSlice(config.PublicIP)
-	if ok {
-		localPub = true
-		addr := netip.AddrPortFrom(ip, config.Port)
-		localAddr.Store(&addr)
-	}
-
-	privKey = config.PrivKey
-	privSignKey = config.PrivSignKey
-
-	if localPub {
-		go addrDiscoveryServer()
-	} else {
-		go addrDiscoveryClient()
-		go relayManager()
-		go localDiscovery()
-	}
-
-	go func() {
-		for range time.Tick(pingInterval) {
-			messages <- pingTimerMsg{}
-		}
-	}()
-
-	go startPeerSuper()
-
-	go newHubPoller().Run()
-	go readFromConn(conn)
-	readFromIFace(iface)
-}
-
-// ----------------------------------------------------------------------------
-
-func readFromConn(conn *net.UDPConn) {
-
-	defer panicHandler()
-
-	var (
-		remoteAddr netip.AddrPort
-		n          int
-		err        error
-		buf        = make([]byte, bufferSize)
-		decBuf     = make([]byte, bufferSize)
-		data       []byte
-		h          header
-	)
-
-	for {
-		n, remoteAddr, err = conn.ReadFromUDPAddrPort(buf[:bufferSize])
-		if err != nil {
-			log.Fatalf("Failed to read from UDP port: %v", err)
-		}
-
-		remoteAddr = netip.AddrPortFrom(remoteAddr.Addr().Unmap(), remoteAddr.Port())
-
-		data = buf[:n]
-
-		if n < headerSize {
-			continue // Packet it soo short.
-		}
-
-		h.Parse(data)
-		switch h.StreamID {
-		case controlStreamID:
-			handleControlPacket(remoteAddr, h, data, decBuf)
-
-		case dataStreamID:
-			handleDataPacket(h, data, decBuf)
-
-		default:
-			log.Printf("Unknown stream ID: %d", h.StreamID)
-		}
-	}
-}
-
-func handleControlPacket(addr netip.AddrPort, h header, data, decBuf []byte) {
-	route := routingTable[h.SourceIP].Load()
-	if route.ControlCipher == nil {
-		//log.Printf("Not connected (control).")
-		return
-	}
-
-	if h.DestIP != localIP {
-		log.Printf("Incorrect destination IP on control packet: %d != %d", h.DestIP, localIP)
-		return
-	}
-
-	out, ok := route.ControlCipher.Decrypt(data, decBuf)
-	if !ok {
-		log.Printf("Failed to decrypt control packet.")
-		return
-	}
-
-	if len(out) == 0 {
-		log.Printf("Empty control packet from: %d", h.SourceIP)
-		return
-	}
-
-	if dupChecks[h.SourceIP].IsDup(h.Counter) {
-		log.Printf("[%03d] Duplicate control packet: %d", h.SourceIP, h.Counter)
-		return
-	}
-
-	msg, err := parseControlMsg(h.SourceIP, addr, out)
-	if err != nil {
-		log.Printf("Failed to parse control packet: %v", err)
-		return
-	}
-
-	if dm, ok := msg.(controlMsg[addrDiscoveryPacket]); ok {
-		discoveryMessages <- dm
-		return
-	}
-
-	select {
-	case messages <- msg:
-	default:
-		log.Printf("Dropping control packet.")
-	}
-
-}
-
-func handleDataPacket(h header, data []byte, decBuf []byte) {
-	route := routingTable[h.SourceIP].Load()
-	if !route.Up {
-		log.Printf("Not connected (recv).")
-		return
-	}
-
-	dec, ok := route.DataCipher.Decrypt(data, decBuf)
-	if !ok {
-		log.Printf("Failed to decrypt data packet.")
-		return
-	}
-
-	if dupChecks[h.SourceIP].IsDup(h.Counter) {
-		log.Printf("[%03d] Duplicate data packet: %d", h.SourceIP, h.Counter)
-		return
-	}
-
-	if h.DestIP == localIP {
-		_iface.Write(dec)
-		return
-	}
-
-	destRoute := routingTable[h.DestIP].Load()
-	if !destRoute.Up {
-		log.Printf("Not connected (relay): %d", destRoute.IP)
-		return
-	}
-
-	_conn.WriteTo(dec, destRoute.RemoteAddr)
-}
-
-// ----------------------------------------------------------------------------
-
-func readFromIFace(iface io.ReadWriteCloser) {
-	var (
-		packet   = make([]byte, bufferSize)
-		buf1     = make([]byte, bufferSize)
-		buf2     = make([]byte, bufferSize)
-		remoteIP byte
-		err      error
-	)
-
-	for {
-		packet, remoteIP, err = readNextPacket(iface, packet)
-		if err != nil {
-			log.Fatalf("Failed to read from interface: %v", err)
-		}
-
-		route := routingTable[remoteIP].Load()
-		if !route.Up {
-			log.Printf("Route not connected: %d", remoteIP)
-			continue
-		}
-
-		_sendDataPacket(route, packet, buf1, buf2)
-	}
-}

node/packets-util_test.go

@@ -1,40 +0,0 @@
-package node
-
-import (
-	"net/netip"
-	"reflect"
-	"testing"
-)
-
-func TestBinWriteRead(t *testing.T) {
-	buf := make([]byte, 1024)
-
-	type Item struct {
-		Type     byte
-		TraceID  uint64
-		DestAddr netip.AddrPort
-	}
-
-	in := Item{1, 2, netip.AddrPortFrom(netip.AddrFrom4([4]byte{1, 2, 3, 4}), 22)}
-
-	buf = newBinWriter(buf).
-		Byte(in.Type).
-		Uint64(in.TraceID).
-		AddrPort(in.DestAddr).
-		Build()
-
-	out := Item{}
-
-	err := newBinReader(buf).
-		Byte(&out.Type).
-		Uint64(&out.TraceID).
-		AddrPort(&out.DestAddr).
-		Error()
-	if err != nil {
-		t.Fatal(err)
-	}
-
-	if !reflect.DeepEqual(in, out) {
-		t.Fatal(in, out)
-	}
-}

node/packets.go

@@ -1,120 +0,0 @@
-package node
-
-import (
-	"errors"
-	"net/netip"
-)
-
-var (
-	errMalformedPacket   = errors.New("malformed packet")
-	errUnknownPacketType = errors.New("unknown packet type")
-)
-
-const (
-	packetTypeSyn = iota + 1
-	packetTypeSynAck
-	packetTypeAck
-	packetTypeProbe
-	packetTypeAddrDiscovery
-)
-
-// ----------------------------------------------------------------------------
-
-type synPacket struct {
-	TraceID   uint64   // TraceID to match response w/ request.
-	SharedKey [32]byte // Our shared key.
-	Direct    bool
-	FromAddr  netip.AddrPort // The client's sending address.
-}
-
-func (p synPacket) Marshal(buf []byte) []byte {
-	return newBinWriter(buf).
-		Byte(packetTypeSyn).
-		Uint64(p.TraceID).
-		SharedKey(p.SharedKey).
-		Bool(p.Direct).
-		AddrPort(p.FromAddr).
-		Build()
-}
-
-func parseSynPacket(buf []byte) (p synPacket, err error) {
-	err = newBinReader(buf[1:]).
-		Uint64(&p.TraceID).
-		SharedKey(&p.SharedKey).
-		Bool(&p.Direct).
-		AddrPort(&p.FromAddr).
-		Error()
-	return
-}
-
-// ----------------------------------------------------------------------------
-
-type ackPacket struct {
-	TraceID  uint64
-	FromAddr netip.AddrPort
-}
-
-func (p ackPacket) Marshal(buf []byte) []byte {
-	return newBinWriter(buf).
-		Byte(packetTypeSynAck).
-		Uint64(p.TraceID).
-		AddrPort(p.FromAddr).
-		Build()
-}
-
-func parseAckPacket(buf []byte) (p ackPacket, err error) {
-	err = newBinReader(buf[1:]).
-		Uint64(&p.TraceID).
-		AddrPort(&p.FromAddr).
-		Error()
-	return
-}
-
-// ----------------------------------------------------------------------------
-
-type addrDiscoveryPacket struct {
-	TraceID uint64
-	ToAddr  netip.AddrPort
-}
-
-func (p addrDiscoveryPacket) Marshal(buf []byte) []byte {
-	return newBinWriter(buf).
-		Byte(packetTypeAddrDiscovery).
-		Uint64(p.TraceID).
-		AddrPort(p.ToAddr).
-		Build()
-}
-
-func parseAddrDiscoveryPacket(buf []byte) (p addrDiscoveryPacket, err error) {
-	err = newBinReader(buf[1:]).
-		Uint64(&p.TraceID).
-		AddrPort(&p.ToAddr).
-		Error()
-	return
-}
-
-// ----------------------------------------------------------------------------
-
-// A probeReqPacket is sent from a client to a server to determine if direct
-// UDP communication can be used.
-type probePacket struct {
-	TraceID uint64
-}
-
-func (p probePacket) Marshal(buf []byte) []byte {
-	return newBinWriter(buf).
-		Byte(packetTypeProbe).
-		Uint64(p.TraceID).
-		Build()
-}
-
-func parseProbePacket(buf []byte) (p probePacket, err error) {
-	err = newBinReader(buf[1:]).
-		Uint64(&p.TraceID).
-		Error()
-	return
-}
-
-// ----------------------------------------------------------------------------
-
-type localDiscoveryPacket struct{}

node/packets_test.go

@@ -1,41 +0,0 @@
-package node
-
-import (
-	"crypto/rand"
-	"net/netip"
-	"reflect"
-	"testing"
-)
-
-func TestPacketSyn(t *testing.T) {
-	in := synPacket{
-		TraceID:  newTraceID(),
-		FromAddr: netip.AddrPortFrom(netip.AddrFrom4([4]byte{4, 5, 6, 7}), 22),
-	}
-	rand.Read(in.SharedKey[:])
-
-	out, err := parseSynPacket(in.Marshal(make([]byte, bufferSize)))
-	if err != nil {
-		t.Fatal(err)
-	}
-
-	if !reflect.DeepEqual(in, out) {
-		t.Fatal("\n", in, "\n", out)
-	}
-}
-
-func TestPacketSynAck(t *testing.T) {
-	in := ackPacket{
-		TraceID:  newTraceID(),
-		FromAddr: netip.AddrPortFrom(netip.AddrFrom4([4]byte{4, 5, 6, 7}), 22),
-	}
-
-	out, err := parseAckPacket(in.Marshal(make([]byte, bufferSize)))
-	if err != nil {
-		t.Fatal(err)
-	}
-
-	if !reflect.DeepEqual(in, out) {
-		t.Fatal("\n", in, "\n", out)
-	}
-}

node/relaymanager.go

@@ -1,40 +0,0 @@
-package node
-
-import (
-	"log"
-	"math/rand"
-	"time"
-)
-
-func relayManager() {
-	time.Sleep(2 * time.Second)
-	updateRelayRoute()
-
-	for range time.Tick(8 * time.Second) {
-		relay := getRelayRoute()
-		if relay == nil || !relay.Up || !relay.Relay {
-			updateRelayRoute()
-		}
-	}
-}
-
-func updateRelayRoute() {
-	possible := make([]*peerRoute, 0, 8)
-	for i := range routingTable {
-		route := routingTable[i].Load()
-		if !route.Up || !route.Relay {
-			continue
-		}
-		possible = append(possible, route)
-	}
-
-	if len(possible) == 0 {
-		log.Printf("No relay available.")
-		relayIP.Store(nil)
-		return
-	}
-
-	ip := possible[rand.Intn(len(possible))].IP
-	log.Printf("New relay IP: %d", ip)
-	relayIP.Store(&ip)
-}

node/supervisor.go

@@ -1,395 +0,0 @@
-package node
-
-import (
-	"fmt"
-	"log"
-	"net/netip"
-	"strings"
-	"sync/atomic"
-	"time"
-	"vppn/m"
-
-	"git.crumpington.com/lib/go/ratelimiter"
-)
-
-const (
-	pingInterval    = 8 * time.Second
-	timeoutInterval = 25 * time.Second
-)
-
-// ----------------------------------------------------------------------------
-
-func startPeerSuper() {
-	peers := [256]peerState{}
-	for i := range peers {
-		data := &peerStateData{
-			published: routingTable[i],
-			remoteIP:  byte(i),
-			buf1:      make([]byte, bufferSize),
-			buf2:      make([]byte, bufferSize),
-			limiter: ratelimiter.New(ratelimiter.Config{
-				FillPeriod:   50 * time.Millisecond,
-				MaxWaitCount: 1,
-			}),
-		}
-		peers[i] = data.OnPeerUpdate(nil)
-	}
-	go runPeerSuper(peers)
-}
-
-func runPeerSuper(peers [256]peerState) {
-	for raw := range messages {
-		switch msg := raw.(type) {
-
-		case peerUpdateMsg:
-			peers[msg.PeerIP] = peers[msg.PeerIP].OnPeerUpdate(msg.Peer)
-
-		case controlMsg[synPacket]:
-			peers[msg.SrcIP].OnSyn(msg)
-
-		case controlMsg[ackPacket]:
-			peers[msg.SrcIP].OnAck(msg)
-
-		case controlMsg[probePacket]:
-			peers[msg.SrcIP].OnProbe(msg)
-
-		case controlMsg[localDiscoveryPacket]:
-			peers[msg.SrcIP].OnLocalDiscovery(msg)
-
-		case pingTimerMsg:
-			for i := range peers {
-				if newState := peers[i].OnPingTimer(); newState != nil {
-					peers[i] = newState
-				}
-			}
-
-		default:
-			log.Printf("WARNING: unknown message type: %+v", msg)
-		}
-	}
-}
-
-// ----------------------------------------------------------------------------
-
-type peerState interface {
-	OnPeerUpdate(*m.Peer) peerState
-	OnSyn(controlMsg[synPacket])
-	OnAck(controlMsg[ackPacket])
-	OnProbe(controlMsg[probePacket])
-	OnLocalDiscovery(controlMsg[localDiscoveryPacket])
-	OnPingTimer() peerState
-}
-
-// ----------------------------------------------------------------------------
-
-type peerStateData struct {
-	// The purpose of this state machine is to manage this published data.
-	published *atomic.Pointer[peerRoute]
-	staged    peerRoute // Local copy of shared data. See publish().
-
-	// Immutable data.
-	remoteIP byte // Remote VPN IP.
-
-	// Mutable peer data.
-	peer      *m.Peer
-	remotePub bool
-
-	// Buffers for sending control packets.
-	buf1 []byte
-	buf2 []byte
-
-	// For logging. Set per-state.
-	client bool
-
-	limiter *ratelimiter.Limiter
-}
-
-// ----------------------------------------------------------------------------
-
-func (s *peerStateData) sendControlPacket(pkt interface{ Marshal([]byte) []byte }) {
-	s._sendControlPacket(pkt, s.staged)
-}
-
-func (s *peerStateData) sendControlPacketTo(pkt interface{ Marshal([]byte) []byte }, addr netip.AddrPort) {
-	if !addr.IsValid() {
-		s.logf("ERROR: Attepted to send packet to invalid address: %v", addr)
-		return
-	}
-	route := s.staged
-	route.Direct = true
-	route.RemoteAddr = addr
-	s._sendControlPacket(pkt, route)
-}
-
-func (s *peerStateData) _sendControlPacket(pkt interface{ Marshal([]byte) []byte }, route peerRoute) {
-	if err := s.limiter.Limit(); err != nil {
-		s.logf("Not sending control packet: rate limited.") // Shouldn't happen.
-		return
-	}
-	_sendControlPacket(pkt, route, s.buf1, s.buf2)
-}
-
-// ----------------------------------------------------------------------------
-
-func (s *peerStateData) publish() {
-	data := s.staged
-	s.published.Store(&data)
-}
-
-func (s *peerStateData) logf(format string, args ...any) {
-	b := strings.Builder{}
-	b.WriteString(fmt.Sprintf("%30s: ", s.peer.Name))
-
-	if s.client {
-		b.WriteString("CLIENT|")
-	} else {
-		b.WriteString("SERVER|")
-	}
-
-	if s.staged.Direct {
-		b.WriteString("DIRECT |")
-	} else {
-		b.WriteString("RELAYED|")
-	}
-
-	if s.staged.Up {
-		b.WriteString("UP  |")
-	} else {
-		b.WriteString("DOWN|")
-	}
-
-	log.Printf(b.String()+format, args...)
-}
-
-// ----------------------------------------------------------------------------
-
-func (s *peerStateData) OnPeerUpdate(peer *m.Peer) peerState {
-	defer s.publish()
-
-	if peer == nil {
-		return enterStateDisconnected(s)
-	}
-
-	s.peer = peer
-	s.staged.IP = s.remoteIP
-	s.staged.PubSignKey = peer.PubSignKey
-	s.staged.ControlCipher = newControlCipher(privKey, peer.PubKey)
-	s.staged.DataCipher = newDataCipher()
-
-	if ip, isValid := netip.AddrFromSlice(peer.PublicIP); isValid {
-		s.remotePub = true
-		s.staged.Relay = peer.Relay
-		s.staged.Direct = true
-		s.staged.RemoteAddr = netip.AddrPortFrom(ip, peer.Port)
-	} else if localPub {
-		s.staged.Direct = true
-	}
-
-	if s.remotePub == localPub {
-		if localIP < s.remoteIP {
-			return enterStateServer(s)
-		}
-		return enterStateClient(s)
-	}
-
-	if s.remotePub {
-		return enterStateClient(s)
-	}
-	return enterStateServer(s)
-}
-
-// ----------------------------------------------------------------------------
-
-type stateDisconnected struct {
-	*peerStateData
-}
-
-func enterStateDisconnected(s *peerStateData) peerState {
-	s.peer = nil
-	s.staged = peerRoute{}
-	s.publish()
-	return &stateDisconnected{s}
-}
-
-func (s *stateDisconnected) OnSyn(controlMsg[synPacket])                       {}
-func (s *stateDisconnected) OnAck(controlMsg[ackPacket])                       {}
-func (s *stateDisconnected) OnProbe(controlMsg[probePacket])                   {}
-func (s *stateDisconnected) OnLocalDiscovery(controlMsg[localDiscoveryPacket]) {}
-
-func (s *stateDisconnected) OnPingTimer() peerState {
-	return nil
-}
-
-// ----------------------------------------------------------------------------
-
-type stateServer struct {
-	*stateDisconnected
-	lastSeen   time.Time
-	synTraceID uint64
-}
-
-func enterStateServer(s *peerStateData) peerState {
-	s.client = false
-	return &stateServer{stateDisconnected: &stateDisconnected{s}}
-}
-
-func (s *stateServer) OnSyn(msg controlMsg[synPacket]) {
-	s.lastSeen = time.Now()
-	p := msg.Packet
-
-	// Before we can respond to this packet, we need to make sure the
-	// route is setup properly.
-	//
-	// The client will update the syn's TraceID whenever there's a change.
-	// The server will follow the client's request.
-	if p.TraceID != s.synTraceID || !s.staged.Up {
-		s.synTraceID = p.TraceID
-		s.staged.Up = true
-		s.staged.Direct = p.Direct
-		s.staged.DataCipher = newDataCipherFromKey(p.SharedKey)
-		s.staged.RemoteAddr = msg.SrcAddr
-		s.publish()
-		s.logf("Got syn.")
-	}
-
-	// Always respond.
-	ack := ackPacket{
-		TraceID:  p.TraceID,
-		FromAddr: getLocalAddr(),
-	}
-	s.sendControlPacket(ack)
-
-	if !s.staged.Direct && p.FromAddr.IsValid() {
-		s.sendControlPacketTo(probePacket{TraceID: newTraceID()}, p.FromAddr)
-	}
-}
-
-func (s *stateServer) OnProbe(msg controlMsg[probePacket]) {
-	if !msg.SrcAddr.IsValid() {
-		s.logf("Invalid probe address.")
-		return
-	}
-	s.sendControlPacketTo(probePacket{TraceID: msg.Packet.TraceID}, msg.SrcAddr)
-}
-
-func (s *stateServer) OnPingTimer() peerState {
-	if time.Since(s.lastSeen) > timeoutInterval && s.staged.Up {
-		s.staged.Up = false
-		s.publish()
-		s.logf("Connection timeout.")
-	}
-	return nil
-}
-
-// ----------------------------------------------------------------------------
-
-type stateClient struct {
-	*stateDisconnected
-
-	lastSeen time.Time
-	syn      synPacket
-	ack      ackPacket
-
-	probeTraceID uint64
-	probeAddr    netip.AddrPort
-
-	localProbeTraceID uint64
-	localProbeAddr    netip.AddrPort
-}
-
-func enterStateClient(s *peerStateData) peerState {
-	s.client = true
-	ss := &stateClient{stateDisconnected: &stateDisconnected{s}}
-	ss.syn = synPacket{
-		TraceID:   newTraceID(),
-		SharedKey: s.staged.DataCipher.Key(),
-		Direct:    s.staged.Direct,
-		FromAddr:  getLocalAddr(),
-	}
-	ss.sendSyn()
-	return ss
-}
-
-func (s *stateClient) OnAck(msg controlMsg[ackPacket]) {
-	if msg.Packet.TraceID != s.syn.TraceID {
-		s.logf("Ack has incorrect trace ID")
-		return
-	}
-
-	s.ack = msg.Packet
-	s.lastSeen = time.Now()
-
-	if !s.staged.Up {
-		s.staged.Up = true
-		s.logf("Got ack.")
-		s.publish()
-	} else {
-	}
-}
-
-func (s *stateClient) OnProbe(msg controlMsg[probePacket]) {
-	if s.staged.Direct {
-		return
-	}
-
-	switch msg.Packet.TraceID {
-	case s.probeTraceID:
-		s.staged.RemoteAddr = s.probeAddr
-	case s.localProbeTraceID:
-		s.staged.RemoteAddr = s.localProbeAddr
-	default:
-		return
-	}
-
-	s.staged.Direct = true
-	s.publish()
-
-	s.syn.TraceID = newTraceID()
-	s.syn.Direct = true
-	s.syn.FromAddr = getLocalAddr()
-	s.sendControlPacket(s.syn)
-
-	s.logf("Established direct connection to %s.", s.staged.RemoteAddr.String())
-}
-
-func (s *stateClient) OnLocalDiscovery(msg controlMsg[localDiscoveryPacket]) {
-	if s.staged.Direct {
-		return
-	}
-
-	// Send probe.
-	//
-	// The source port will be the multicast port, so we'll have to
-	// construct the correct address using the peer's listed port.
-	s.localProbeTraceID = newTraceID()
-	s.localProbeAddr = netip.AddrPortFrom(msg.SrcAddr.Addr(), s.peer.Port)
-	s.sendControlPacketTo(probePacket{TraceID: s.localProbeTraceID}, s.localProbeAddr)
-}
-
-func (s *stateClient) OnPingTimer() peerState {
-	if time.Since(s.lastSeen) > timeoutInterval {
-		if s.staged.Up {
-			s.logf("Connection timeout.")
-		}
-		return s.OnPeerUpdate(s.peer)
-	}
-
-	s.sendSyn()
-
-	if !s.staged.Direct && s.ack.FromAddr.IsValid() {
-		s.probeTraceID = newTraceID()
-		s.probeAddr = s.ack.FromAddr
-		s.sendControlPacketTo(probePacket{TraceID: s.probeTraceID}, s.probeAddr)
-	}
-
-	return nil
-}
-
-func (s *stateClient) sendSyn() {
-	localAddr := getLocalAddr()
-	if localAddr != s.syn.FromAddr {
-		s.syn.TraceID = newTraceID()
-		s.syn.FromAddr = localAddr
-	}
-	s.sendControlPacket(s.syn)
-}

peer/bitset.go

@@ -1,4 +1,4 @@
-package node
+package peer
 
 const bitSetSize = 512 // Multiple of 64.
 

peer/bitset_test.go

@@ -1,4 +1,4 @@
-package node
+package peer
 
 import (
 	"math/rand"

peer/cipher-control.go

@@ -1,4 +1,4 @@
-package node
+package peer
 
 import "golang.org/x/crypto/nacl/box"
 
@@ -12,7 +12,7 @@ func newControlCipher(privKey, pubKey []byte) *controlCipher {
 	return &controlCipher{shared}
 }
 
-func (cc *controlCipher) Encrypt(h header, data, out []byte) []byte {
+func (cc *controlCipher) Encrypt(h Header, data, out []byte) []byte {
 	const s = controlHeaderSize
 	out = out[:s+controlCipherOverhead+len(data)]
 	h.Marshal(out[:s])

peer/cipher-control_test.go

@@ -1,4 +1,4 @@
-package node
+package peer
 
 import (
 	"bytes"
@@ -40,7 +40,7 @@ func TestControlCipher(t *testing.T) {
 	}
 
 	for _, plaintext := range testCases {
-		h1 := header{
+		h1 := Header{
 			StreamID: controlStreamID,
 			Counter:  235153,
 			SourceIP: 4,
@@ -51,7 +51,7 @@ func TestControlCipher(t *testing.T) {
 
 		encrypted = c1.Encrypt(h1, plaintext, encrypted)
 
-		h2 := header{}
+		h2 := Header{}
 		h2.Parse(encrypted)
 		if !reflect.DeepEqual(h1, h2) {
 			t.Fatal(h1, h2)
@@ -80,7 +80,7 @@ func TestControlCipher_ShortCiphertext(t *testing.T) {
 
 func BenchmarkControlCipher_Encrypt(b *testing.B) {
 	c1, _ := newControlCipherForTesting()
-	h1 := header{
+	h1 := Header{
 		Counter:  235153,
 		SourceIP: 4,
 		DestIP:   88,
@@ -100,7 +100,7 @@ func BenchmarkControlCipher_Encrypt(b *testing.B) {
 func BenchmarkControlCipher_Decrypt(b *testing.B) {
 	c1, c2 := newControlCipherForTesting()
 
-	h1 := header{
+	h1 := Header{
 		Counter:  235153,
 		SourceIP: 4,
 		DestIP:   88,

peer/cipher-data.go

@@ -1,9 +1,10 @@
-package node
+package peer
 
 import (
 	"crypto/aes"
 	"crypto/cipher"
 	"crypto/rand"
+	"log"
 )
 
 type dataCipher struct {
@@ -14,7 +15,7 @@ type dataCipher struct {
 func newDataCipher() *dataCipher {
 	key := [32]byte{}
 	if _, err := rand.Read(key[:]); err != nil {
-		panic(err)
+		log.Fatalf("Failed to read random data: %v", err)
 	}
 	return newDataCipherFromKey(key)
 }
@@ -22,12 +23,12 @@ func newDataCipher() *dataCipher {
 func newDataCipherFromKey(key [32]byte) *dataCipher {
 	block, err := aes.NewCipher(key[:])
 	if err != nil {
-		panic(err)
+		log.Fatalf("Failed to create new cipher: %v", err)
 	}
 
 	aead, err := cipher.NewGCM(block)
 	if err != nil {
-		panic(err)
+		log.Fatalf("Failed to create new GCM: %v", err)
 	}
 
 	return &dataCipher{key: key, aead: aead}
@@ -37,7 +38,7 @@ func (sc *dataCipher) Key() [32]byte {
 	return sc.key
 }
 
-func (sc *dataCipher) Encrypt(h header, data, out []byte) []byte {
+func (sc *dataCipher) Encrypt(h Header, data, out []byte) []byte {
 	const s = dataHeaderSize
 	out = out[:s+dataCipherOverhead+len(data)]
 	h.Marshal(out[:s])

peer/cipher-data_test.go

@@ -1,4 +1,4 @@
-package node
+package peer
 
 import (
 	"bytes"
@@ -22,7 +22,7 @@ func TestDataCipher(t *testing.T) {
 	}
 
 	for _, plaintext := range testCases {
-		h1 := header{
+		h1 := Header{
 			StreamID: dataStreamID,
 			Counter:  235153,
 			SourceIP: 4,
@@ -33,7 +33,7 @@ func TestDataCipher(t *testing.T) {
 
 		dc1 := newDataCipher()
 		encrypted = dc1.Encrypt(h1, plaintext, encrypted)
-		h2 := header{}
+		h2 := Header{}
 		h2.Parse(encrypted)
 
 		dc2 := newDataCipherFromKey(dc1.Key())
@@ -67,7 +67,7 @@ func TestDataCipher_ModifyCiphertext(t *testing.T) {
 	}
 
 	for _, plaintext := range testCases {
-		h1 := header{
+		h1 := Header{
 			Counter:  235153,
 			SourceIP: 4,
 			DestIP:   88,
@@ -99,7 +99,7 @@ func TestDataCipher_ShortCiphertext(t *testing.T) {
 }
 
 func BenchmarkDataCipher_Encrypt(b *testing.B) {
-	h1 := header{
+	h1 := Header{
 		Counter:  235153,
 		SourceIP: 4,
 		DestIP:   88,
@@ -118,7 +118,7 @@ func BenchmarkDataCipher_Encrypt(b *testing.B) {
 }
 
 func BenchmarkDataCipher_Decrypt(b *testing.B) {
-	h1 := header{
+	h1 := Header{
 		Counter:  235153,
 		SourceIP: 4,
 		DestIP:   88,

peer/connreader.go

@@ -0,0 +1,46 @@
+package peer
+
+import (
+	"log"
+	"net"
+	"net/netip"
+)
+
+type ConnReader struct {
+	Globals
+	conn *net.UDPConn
+	buf  []byte
+}
+
+func NewConnReader(g Globals, conn *net.UDPConn) *ConnReader {
+	return &ConnReader{
+		Globals: g,
+		conn:    conn,
+		buf:     make([]byte, bufferSize),
+	}
+}
+
+func (r *ConnReader) Run() {
+	for {
+		r.handleNextPacket()
+	}
+}
+
+func (r *ConnReader) handleNextPacket() {
+	buf := r.buf[:bufferSize]
+	n, remoteAddr, err := r.conn.ReadFromUDPAddrPort(buf)
+	if err != nil {
+		log.Fatalf("Failed to read from UDP port: %v", err)
+	}
+
+	if n < headerSize {
+		return
+	}
+
+	remoteAddr = netip.AddrPortFrom(remoteAddr.Addr().Unmap(), remoteAddr.Port())
+
+	buf = buf[:n]
+	h := parseHeader(buf)
+
+	r.RemotePeers[h.SourceIP].Load().HandlePacket(h, remoteAddr, buf)
+}

peer/controlmessage.go

@@ -1,4 +1,4 @@
-package node
+package peer
 
 import (
 	"net/netip"
@@ -16,33 +16,33 @@ type controlMsg[T any] struct {
 func parseControlMsg(srcIP byte, srcAddr netip.AddrPort, buf []byte) (any, error) {
 	switch buf[0] {
 
-	case packetTypeSyn:
-		packet, err := parseSynPacket(buf)
-		return controlMsg[synPacket]{
+	case packetTypeInit:
+		packet, err := parsePacketInit(buf)
+		return controlMsg[packetInit]{
 			SrcIP:   srcIP,
 			SrcAddr: srcAddr,
 			Packet:  packet,
 		}, err
 
-	case packetTypeSynAck:
-		packet, err := parseAckPacket(buf)
-		return controlMsg[ackPacket]{
+	case packetTypeSyn:
+		packet, err := parsePacketSyn(buf)
+		return controlMsg[packetSyn]{
+			SrcIP:   srcIP,
+			SrcAddr: srcAddr,
+			Packet:  packet,
+		}, err
+
+	case packetTypeAck:
+		packet, err := parsePacketAck(buf)
+		return controlMsg[packetAck]{
 			SrcIP:   srcIP,
 			SrcAddr: srcAddr,
 			Packet:  packet,
 		}, err
 
 	case packetTypeProbe:
-		packet, err := parseProbePacket(buf)
-		return controlMsg[probePacket]{
-			SrcIP:   srcIP,
-			SrcAddr: srcAddr,
-			Packet:  packet,
-		}, err
-
-	case packetTypeAddrDiscovery:
-		packet, err := parseAddrDiscoveryPacket(buf)
-		return controlMsg[addrDiscoveryPacket]{
+		packet, err := parsePacketProbe(buf)
+		return controlMsg[packetProbe]{
 			SrcIP:   srcIP,
 			SrcAddr: srcAddr,
 			Packet:  packet,
@@ -56,12 +56,9 @@ func parseControlMsg(srcIP byte, srcAddr netip.AddrPort, buf []byte) (any, error
 // ----------------------------------------------------------------------------
 
 type peerUpdateMsg struct {
-	PeerIP byte
-	Peer   *m.Peer
+	Peer *m.Peer
 }
 
 // ----------------------------------------------------------------------------
 
 type pingTimerMsg struct{}
-
-// ----------------------------------------------------------------------------

peer/crypto.go

@@ -0,0 +1,30 @@
+package peer
+
+import (
+	"crypto/rand"
+	"log"
+
+	"golang.org/x/crypto/nacl/box"
+	"golang.org/x/crypto/nacl/sign"
+)
+
+type cryptoKeys struct {
+	PubKey      []byte
+	PrivKey     []byte
+	PubSignKey  []byte
+	PrivSignKey []byte
+}
+
+func generateKeys() cryptoKeys {
+	pubKey, privKey, err := box.GenerateKey(rand.Reader)
+	if err != nil {
+		log.Fatalf("Failed to generate encryption keys: %v", err)
+	}
+
+	pubSignKey, privSignKey, err := sign.GenerateKey(rand.Reader)
+	if err != nil {
+		log.Fatalf("Failed to generate signing keys: %v", err)
+	}
+
+	return cryptoKeys{pubKey[:], privKey[:], pubSignKey[:], privSignKey[:]}
+}

peer/data-flow.dot

@@ -0,0 +1,13 @@
+digraph d {
+    ifReader   -> remote;
+
+    connReader -> remote;
+    mcReader   -> remote;
+    remote -> connWriter;
+    remote -> ifWriter;
+    hubPoller  -> remote;
+
+    connWriter [shape="box"];
+    mcWriter [shape="box"];
+    ifWriter [shape="box"];
+}

peer/dupcheck.go

@@ -1,4 +1,4 @@
-package node
+package peer
 
 type dupCheck struct {
 	bitSet
@@ -38,20 +38,20 @@ func (dc *dupCheck) IsDup(counter uint64) bool {
 	delta := counter - dc.tailCounter
 
 	// Full clear.
-	if delta >= bitSetSize {
+	if delta >= bitSetSize-1 {
 		dc.ClearAll()
 		dc.Set(0)
 
 		dc.tail = 1
 		dc.head = 2
 		dc.tailCounter = counter + 1
-		dc.headCounter = dc.tailCounter - bitSetSize
+		dc.headCounter = dc.tailCounter - bitSetSize + 1
 
 		return false
 	}
 
 	// Clear if necessary.
-	for i := 0; i < int(delta); i++ {
+	for range delta {
 		dc.put(false)
 	}
 

peer/dupcheck_test.go

@@ -1,4 +1,4 @@
-package node
+package peer
 
 import (
 	"testing"
@@ -19,6 +19,7 @@ func TestDupCheck(t *testing.T) {
 	}
 
 	testCases := []TestCase{
+		{511, true},
 		{0, true},
 		{1, true},
 		{2, true},
@@ -39,11 +40,13 @@ func TestDupCheck(t *testing.T) {
 		{516, false},
 		{517, true},
 		{2512, false},
-		{2000, true},
-		{2001, false},
+		{2512, true},
+		{2001, true},
+		{2002, false},
+		{2002, true},
 		{4000, false},
-		{4000 - 512, true},  // Too old.
-		{4000 - 511, false}, // Just in the window.
+		{4000 - 511, true},  // Too old.
+		{4000 - 510, false}, // Just in the window.
 	}
 
 	for i, tc := range testCases {

peer/errors.go

@@ -0,0 +1,8 @@
+package peer
+
+import "errors"
+
+var (
+	errMalformedPacket   = errors.New("malformed packet")
+	errUnknownPacketType = errors.New("unknown packet type")
+)

peer/files.go

@@ -1,4 +1,4 @@
-package node
+package peer
 
 import (
 	"encoding/json"
@@ -8,6 +8,19 @@ import (
 	"vppn/m"
 )
 
+type LocalConfig struct {
+	LocalPeerIP byte
+	Network     []byte
+	PubKey      []byte
+	PrivKey     []byte
+	PubSignKey  []byte
+	PrivSignKey []byte
+}
+
+type startupCount struct {
+	Count uint16
+}
+
 func configDir(netName string) string {
 	d, err := os.UserHomeDir()
 	if err != nil {
@@ -16,12 +29,24 @@ func configDir(netName string) string {
 	return filepath.Join(d, ".vppn", netName)
 }
 
+func lockFilePath(netName string) string {
+	return filepath.Join(configDir(netName), "__lock__")
+}
+
 func peerConfigPath(netName string) string {
-	return filepath.Join(configDir(netName), "peer-config.json")
+	return filepath.Join(configDir(netName), "config.json")
 }
 
 func peerStatePath(netName string) string {
-	return filepath.Join(configDir(netName), "peer-state.json")
+	return filepath.Join(configDir(netName), "state.json")
+}
+
+func startupCountPath(netName string) string {
+	return filepath.Join(configDir(netName), "startup_count.json")
+}
+
+func statusSocketPath(netName string) string {
+	return filepath.Join(configDir(netName), "status.sock")
 }
 
 func storeJson(x any, outPath string) error {
@@ -56,7 +81,7 @@ func storeJson(x any, outPath string) error {
 	return os.Rename(tmpPath, outPath)
 }
 
-func storePeerConfig(netName string, pc localConfig) error {
+func storePeerConfig(netName string, pc LocalConfig) error {
 	return storeJson(pc, peerConfigPath(netName))
 }
 
@@ -73,10 +98,18 @@ func loadJson(dataPath string, ptr any) error {
 	return json.Unmarshal(data, ptr)
 }
 
-func loadPeerConfig(netName string) (pc localConfig, err error) {
+func loadPeerConfig(netName string) (pc LocalConfig, err error) {
 	return pc, loadJson(peerConfigPath(netName), &pc)
 }
 
 func loadNetworkState(netName string) (ps m.NetworkState, err error) {
 	return ps, loadJson(peerStatePath(netName), &ps)
 }
+
+func loadStartupCount(netName string) (c startupCount, err error) {
+	return c, loadJson(startupCountPath(netName), &c)
+}
+
+func storeStartupCount(netName string, c startupCount) error {
+	return storeJson(c, startupCountPath(netName))
+}

peer/files_test.go

@@ -0,0 +1,57 @@
+package peer
+
+import (
+	"path/filepath"
+	"reflect"
+	"testing"
+)
+
+func TestFilePaths(t *testing.T) {
+	confDir := configDir("netName")
+	if filepath.Base(confDir) != "netName" {
+		t.Fatal(confDir)
+	}
+	if filepath.Base(filepath.Dir(confDir)) != ".vppn" {
+		t.Fatal(confDir)
+	}
+
+	path := peerConfigPath("netName")
+	if path != filepath.Join(confDir, "config.json") {
+		t.Fatal(path)
+	}
+
+	path = peerStatePath("netName")
+	if path != filepath.Join(confDir, "state.json") {
+		t.Fatal(path)
+	}
+}
+
+func TestStoreLoadJson(t *testing.T) {
+	type Object struct {
+		Name  string
+		Age   int
+		Price float64
+	}
+
+	tmpDir := t.TempDir()
+	outPath := filepath.Join(tmpDir, "object.json")
+
+	obj := Object{
+		Name:  "Jason",
+		Age:   22,
+		Price: 123.534,
+	}
+
+	if err := storeJson(obj, outPath); err != nil {
+		t.Fatal(err)
+	}
+
+	obj2 := Object{}
+	if err := loadJson(outPath, &obj2); err != nil {
+		t.Fatal(err)
+	}
+
+	if !reflect.DeepEqual(obj, obj2) {
+		t.Fatal(obj, obj2)
+	}
+}

peer/globals.go

@@ -0,0 +1,109 @@
+package peer
+
+import (
+	"io"
+	"net"
+	"net/netip"
+	"sync"
+	"sync/atomic"
+	"time"
+)
+
+const (
+	version = 1
+
+	bufferSize = 8192 // Enough for data packets and encryption buffers.
+
+	if_mtu       = 1200
+	if_queue_len = 2048
+
+	controlCipherOverhead = 16
+	dataCipherOverhead    = 16
+	signingOverhead       = 64
+
+	pingInterval                  = 8 * time.Second
+	timeoutInterval               = 30 * time.Second
+	broadcastInterval             = 16 * time.Second
+	broadcastErrorTimeoutInterval = 8 * time.Second
+)
+
+var multicastAddr = net.UDPAddrFromAddrPort(netip.AddrPortFrom(
+	netip.AddrFrom4([4]byte{224, 0, 0, 157}),
+	4560))
+
+// ----------------------------------------------------------------------------
+
+type Globals struct {
+	LocalConfig // Embed, immutable.
+
+	// The number of startups
+	StartupCount uint16
+
+	// Local public address (if available). Immutable.
+	LocalAddr netip.AddrPort
+
+	// True if local public address is valid. Immutable.
+	LocalAddrValid bool
+
+	// All remote peers by VPN IP.
+	RemotePeers [256]*atomic.Pointer[Remote]
+
+	// Discovered public addresses.
+	PubAddrs *pubAddrStore
+
+	// Attempts to ensure that we have a relay available.
+	RelayHandler *relayHandler
+
+	// Send UDP - Global function to write UDP packets.
+	SendUDP func(b []byte, addr netip.AddrPort) (n int, err error)
+
+	// Global TUN interface.
+	IFace io.ReadWriteCloser
+
+	// For trace ID.
+	NewTraceID func() uint64
+}
+
+func NewGlobals(
+	localConfig LocalConfig,
+	startupCount startupCount,
+	localAddr netip.AddrPort,
+	conn *net.UDPConn,
+	iface io.ReadWriteCloser,
+) (g Globals) {
+	g.LocalConfig = localConfig
+	g.StartupCount = startupCount.Count
+
+	g.LocalAddr = localAddr
+	g.LocalAddrValid = localAddr.IsValid()
+
+	g.PubAddrs = newPubAddrStore(localAddr)
+
+	g.RelayHandler = newRelayHandler()
+
+	// Use a lock here avoids starvation, at least on my Linux machine.
+	sendLock := sync.Mutex{}
+	g.SendUDP = func(b []byte, addr netip.AddrPort) (int, error) {
+		sendLock.Lock()
+		n, err := conn.WriteToUDPAddrPort(b, addr)
+		sendLock.Unlock()
+		return n, err
+	}
+
+	g.IFace = iface
+
+	traceID := (uint64(g.StartupCount) << 48) + 1
+	g.NewTraceID = func() uint64 {
+		return atomic.AddUint64(&traceID, 1)
+	}
+
+	for i := range g.RemotePeers {
+		g.RemotePeers[i] = &atomic.Pointer[Remote]{}
+	}
+
+	for i := range g.RemotePeers {
+		g.RemotePeers[i].Store(newRemote(g, byte(i)))
+	}
+
+	return g
+}

peer/header.go

@@ -0,0 +1,47 @@
+package peer
+
+import "unsafe"
+
+// ----------------------------------------------------------------------------
+
+const (
+	headerSize        = 12
+	controlHeaderSize = 24
+	dataHeaderSize    = 12
+
+	dataStreamID    = 1
+	controlStreamID = 2
+)
+
+type Header struct {
+	Version  byte
+	StreamID byte
+	SourceIP byte
+	DestIP   byte
+	Counter  uint64 // Init with time.Now().Unix << 30 to ensure monotonic.
+}
+
+func parseHeader(b []byte) (h Header) {
+	h.Version = b[0]
+	h.StreamID = b[1]
+	h.SourceIP = b[2]
+	h.DestIP = b[3]
+	h.Counter = *(*uint64)(unsafe.Pointer(&b[4]))
+	return h
+}
+
+func (h *Header) Parse(b []byte) {
+	h.Version = b[0]
+	h.StreamID = b[1]
+	h.SourceIP = b[2]
+	h.DestIP = b[3]
+	h.Counter = *(*uint64)(unsafe.Pointer(&b[4]))
+}
+
+func (h *Header) Marshal(buf []byte) {
+	buf[0] = h.Version
+	buf[1] = h.StreamID
+	buf[2] = h.SourceIP
+	buf[3] = h.DestIP
+	*(*uint64)(unsafe.Pointer(&buf[4])) = h.Counter
+}

peer/header_test.go

@@ -1,9 +1,9 @@
-package node
+package peer
 
 import "testing"
 
 func TestHeaderMarshalParse(t *testing.T) {
-	nIn := header{
+	nIn := Header{
 		StreamID: 23,
 		Counter:  3212,
 		SourceIP: 34,
@@ -13,7 +13,7 @@ func TestHeaderMarshalParse(t *testing.T) {
 	buf := make([]byte, headerSize)
 	nIn.Marshal(buf)
 
-	nOut := header{}
+	nOut := Header{}
 	nOut.Parse(buf)
 	if nIn != nOut {
 		t.Fatal(nIn, nOut)

peer/hubpoller.go

@@ -0,0 +1,111 @@
+package peer
+
+import (
+	"encoding/json"
+	"io"
+	"log"
+	"net/http"
+	"net/url"
+	"time"
+	"vppn/m"
+)
+
+type HubPoller struct {
+	Globals
+	client   *http.Client
+	req      *http.Request
+	versions [256]int64
+	netName  string
+}
+
+func NewHubPoller(
+	g Globals,
+	netName,
+	hubURL,
+	apiKey string,
+) (*HubPoller, error) {
+	u, err := url.Parse(hubURL)
+	if err != nil {
+		return nil, err
+	}
+	u.Path = "/peer/fetch-state/"
+
+	client := &http.Client{Timeout: 8 * time.Second}
+
+	req := &http.Request{
+		Method: http.MethodGet,
+		URL:    u,
+		Header: http.Header{},
+	}
+	req.SetBasicAuth("", apiKey)
+
+	return &HubPoller{
+		Globals: g,
+		client:  client,
+		req:     req,
+		netName: netName,
+	}, nil
+}
+
+func (hp *HubPoller) logf(s string, args ...any) {
+	log.Printf("[HubPoller] "+s, args...)
+}
+
+func (hp *HubPoller) Run() {
+	state, err := loadNetworkState(hp.netName)
+	if err != nil {
+		hp.logf("Failed to load network state: %v", err)
+		hp.logf("Polling hub...")
+		hp.pollHub()
+	} else {
+		hp.applyNetworkState(state)
+	}
+
+	for range time.Tick(64 * time.Second) {
+		hp.pollHub()
+	}
+}
+
+func (hp *HubPoller) pollHub() {
+	var state m.NetworkState
+
+	resp, err := hp.client.Do(hp.req)
+	if err != nil {
+		hp.logf("Failed to fetch peer state: %v", err)
+		return
+	}
+	body, err := io.ReadAll(resp.Body)
+	_ = resp.Body.Close()
+	if err != nil {
+		hp.logf("Failed to read body from hub: %v", err)
+		return
+	}
+
+	if err := json.Unmarshal(body, &state); err != nil {
+		hp.logf("Failed to unmarshal response from hub: %v\n%s", err, body)
+		return
+	}
+
+	if err := storeNetworkState(hp.netName, state); err != nil {
+		hp.logf("Failed to store network state: %v", err)
+	}
+
+	hp.applyNetworkState(state)
+}
+
+func (hp *HubPoller) applyNetworkState(state m.NetworkState) {
+	for i, peer := range state.Peers {
+		if i == int(hp.LocalPeerIP) {
+			continue
+		}
+
+		if peer != nil && peer.Version == hp.versions[i] {
+			continue
+		}
+
+		hp.RemotePeers[i].Load().HandlePeerUpdate(peerUpdateMsg{Peer: state.Peers[i]})
+		if peer != nil {
+			hp.versions[i] = peer.Version
+		}
+	}
+}

peer/ifreader.go

@@ -0,0 +1,73 @@
+package peer
+
+import (
+	"log"
+)
+
+type IFReader struct {
+	Globals
+}
+
+func NewIFReader(g Globals) *IFReader {
+	return &IFReader{Globals: g}
+}
+
+func (r *IFReader) Run() {
+	packet := make([]byte, bufferSize)
+	for {
+		r.handleNextPacket(packet)
+	}
+}
+
+func (r *IFReader) handleNextPacket(packet []byte) {
+	packet = r.readNextPacket(packet)
+	remoteIP, ok := r.parsePacket(packet)
+	if !ok {
+		return
+	}
+	r.RemotePeers[remoteIP].Load().SendDataTo(packet)
+}
+
+func (r *IFReader) readNextPacket(buf []byte) []byte {
+	n, err := r.IFace.Read(buf[:cap(buf)])
+	if err != nil {
+		log.Fatalf("Failed to read from interface: %v", err)
+	}
+
+	return buf[:n]
+}
+
+// parsePacket returns the VPN ip for the packet, and a boolean indicating
+// success.
+func (r *IFReader) parsePacket(buf []byte) (byte, bool) {
+	n := len(buf)
+	if n == 0 {
+		return 0, false
+	}
+
+	version := buf[0] >> 4
+
+	switch version {
+	case 4:
+		if n < 20 {
+			r.logf("Short IPv4 packet: %d", len(buf))
+			return 0, false
+		}
+		return buf[19], true
+
+	case 6:
+		if len(buf) < 40 {
+			r.logf("Short IPv6 packet: %d", len(buf))
+			return 0, false
+		}
+		return buf[39], true
+
+	default:
+		r.logf("Invalid IP packet version: %v", version)
+		return 0, false
+	}
+}
+
+func (*IFReader) logf(s string, args ...any) {
+	log.Printf("[IFReader] "+s, args...)
+}

peer/ifreader_test.go

@@ -0,0 +1,81 @@
+package peer
+
+/*
+func TestIFReader_IPv4(t *testing.T) {
+	p1, p2, _ := NewPeersForTesting()
+
+	pkt := make([]byte, 1234)
+	pkt[0] = 4 << 4
+	pkt[19] = 2 // IP.
+
+	p1.IFace.UserWrite(pkt)
+	p1.IFReader.handleNextPacket(newBuf())
+
+	packets := p2.Conn.Packets()
+	if len(packets) != 1 {
+		t.Fatal(packets)
+	}
+}
+
+func TestIFReader_IPv6(t *testing.T) {
+	p1, p2, _ := NewPeersForTesting()
+
+	pkt := make([]byte, 1234)
+	pkt[0] = 6 << 4
+	pkt[39] = 2 // IP.
+
+	p1.IFace.UserWrite(pkt)
+	p1.IFReader.handleNextPacket(newBuf())
+
+	packets := p2.Conn.Packets()
+	if len(packets) != 1 {
+		t.Fatal(packets)
+	}
+}
+
+func TestIFReader_parsePacket_emptyPacket(t *testing.T) {
+	r := NewIFReader(nil, nil)
+	pkt := make([]byte, 0)
+	if ip, ok := r.parsePacket(pkt); ok {
+		t.Fatal(ip, ok)
+	}
+}
+
+func TestIFReader_parsePacket_invalidIPVersion(t *testing.T) {
+	r := NewIFReader(nil, nil)
+
+	for i := byte(1); i < 16; i++ {
+		if i == 4 || i == 6 {
+			continue
+		}
+		pkt := make([]byte, 1234)
+		pkt[0] = i << 4
+
+		if ip, ok := r.parsePacket(pkt); ok {
+			t.Fatal(i, ip, ok)
+		}
+	}
+}
+
+func TestIFReader_parsePacket_shortIPv4(t *testing.T) {
+	r := NewIFReader(nil, nil)
+
+	pkt := make([]byte, 19)
+	pkt[0] = 4 << 4
+
+	if ip, ok := r.parsePacket(pkt); ok {
+		t.Fatal(ip, ok)
+	}
+}
+
+func TestIFReader_parsePacket_shortIPv6(t *testing.T) {
+	r := NewIFReader(nil, nil)
+
+	pkt := make([]byte, 39)
+	pkt[0] = 6 << 4
+
+	if ip, ok := r.parsePacket(pkt); ok {
+		t.Fatal(ip, ok)
+	}
+}
+*/

peer/interface.go

@@ -1,9 +1,8 @@
-package node
+package peer
 
 import (
 	"fmt"
 	"io"
-	"log"
 	"net"
 	"os"
 	"syscall"
@@ -11,45 +10,6 @@ import (
 	"golang.org/x/sys/unix"
 )
 
-// Get next packet, returning packet, ip, and possible error.
-func readNextPacket(iface io.ReadWriteCloser, buf []byte) ([]byte, byte, error) {
-	var (
-		version byte
-		ip      byte
-	)
-	for {
-		n, err := iface.Read(buf[:cap(buf)])
-		if err != nil {
-			return nil, ip, err
-		}
-
-		buf = buf[:n]
-		version = buf[0] >> 4
-
-		switch version {
-		case 4:
-			if n < 20 {
-				log.Printf("Short IPv4 packet: %d", len(buf))
-				continue
-			}
-			ip = buf[19]
-
-		case 6:
-			if len(buf) < 40 {
-				log.Printf("Short IPv6 packet: %d", len(buf))
-				continue
-			}
-			ip = buf[39]
-
-		default:
-			log.Printf("Invalid IP packet version: %v", version)
-			continue
-		}
-
-		return buf, ip, nil
-	}
-}
-
 func openInterface(network []byte, localIP byte, name string) (io.ReadWriteCloser, error) {
 	if len(network) != 4 {
 		return nil, fmt.Errorf("expected network to be 4 bytes, got %d", len(network))

peer/main.go

@@ -0,0 +1,209 @@
+package peer
+
+import (
+	"encoding/json"
+	"fmt"
+	"log"
+	"net"
+	"net/http"
+	"net/netip"
+	"os"
+	"time"
+)
+
+// Usage:
+//
+// vppn netName run
+// vppn netName status
+func Main2() {
+	printUsage := func() {
+		fmt.Fprintf(os.Stderr, `%s COMMAND [ARGUMENTS...]
+
+Available commands:
+    run
+    status
+    hosts
+`, os.Args[0])
+		os.Exit(1)
+	}
+
+	if len(os.Args) < 2 {
+		printUsage()
+	}
+
+	command := os.Args[1]
+
+	switch command {
+	case "run":
+		main_run()
+	case "status":
+		main_status()
+	case "hosts":
+		main_hosts()
+	default:
+		printUsage()
+	}
+}
+
+// ----------------------------------------------------------------------------
+
+type mainArgs struct {
+	NetName    string
+	HubAddress string
+	APIKey     string
+}
+
+func main_run() {
+	printUsage := func() {
+		fmt.Fprintf(os.Stderr, `Usage: %s run NETWORK_NAME HUB_ADDRESS API_KEY
+
+    NETWORK_NAME
+        Unique name of the network interface created. The network name
+        shouldn't change between invocations of the application.
+
+    HUB_ADDRESS
+        The address of the hub server. This should also contain the scheme, for
+        example https://hub.domain.com/.
+
+    API_KEY
+        The API key assigned to this peer by the hub.
+
+`, os.Args[0])
+		os.Exit(1)
+	}
+
+	if len(os.Args) != 5 {
+		printUsage()
+	}
+
+	args := mainArgs{
+		NetName:    os.Args[2],
+		HubAddress: os.Args[3],
+		APIKey:     os.Args[4],
+	}
+
+	newPeerMain(args).Run()
+}
+
+// ----------------------------------------------------------------------------
+
+func main_status() {
+	printUsage := func() {
+		fmt.Fprintf(os.Stderr, `Usage: %s status NETWORK_NAME
+
+    NETWORK_NAME
+        Unique name of the network interface created.
+
+`, os.Args[0])
+		os.Exit(1)
+	}
+
+	if len(os.Args) != 3 {
+		printUsage()
+	}
+
+	netName := os.Args[2]
+	report := fetchStatusReport(netName)
+
+	fmt.Printf("\n%s Status\n\n", netName)
+
+	if len(report.Network) != 4 {
+		fmt.Println("ERROR: Network isn't 4 bytes.")
+		fmt.Printf("Network: %v\n\n", report.Network)
+	} else {
+		nw := report.Network
+		fmt.Printf("%-8s %d.%d.%d.%d\n", "IP", nw[0], nw[1], nw[2], report.LocalPeerIP)
+		fmt.Printf("%-8s %d.%d.%d.%d/24\n", "Network", nw[0], nw[1], nw[2], nw[3])
+	}
+
+	if report.RelayPeerIP != 0 {
+		fmt.Printf("%-8s %d\n\n", "Relay", report.RelayPeerIP)
+	} else {
+		fmt.Printf("%-8s -\n\n", "Relay")
+	}
+
+	for _, status := range report.Remotes {
+		fmt.Printf("%3d %s\n", status.PeerIP, status.Name)
+		fmt.Printf("    %-11s %v\n", "Up", status.Up)
+
+		pubIP, ok := netip.AddrFromSlice(status.PublicIP)
+		if ok {
+			fmt.Printf("    %-11s %v\n", "Public IP", pubIP)
+		} else {
+			fmt.Printf("    %-11s\n", "Public IP")
+		}
+		fmt.Printf("    %-11s %d\n", "Port", status.Port)
+		fmt.Printf("    %-11s %v\n", "Relay", status.Relay)
+		fmt.Printf("    %-11s %v\n", "Server", status.Server)
+		fmt.Printf("    %-11s %v\n", "Direct", status.Direct)
+		if status.DirectAddr.IsValid() {
+			fmt.Printf("    %-11s %v\n", "Address", status.DirectAddr)
+		}
+		fmt.Println("")
+	}
+}
+
+// ----------------------------------------------------------------------------
+
+func main_hosts() {
+	printUsage := func() {
+		fmt.Fprintf(os.Stderr, `Usage: %s hosts NETWORK_NAME
+
+    NETWORK_NAME
+        Unique name of the network interface created.
+
+`, os.Args[0])
+		os.Exit(1)
+	}
+
+	if len(os.Args) != 3 {
+		printUsage()
+	}
+
+	netName := os.Args[2]
+	state, err := loadNetworkState(netName)
+	if err != nil {
+		log.Fatalf("Failed to load network state: %v", err)
+	}
+
+	config, err := loadPeerConfig(netName)
+	if err != nil {
+		log.Fatalf("Failed to load config: %v", err)
+	}
+
+	nw := config.Network
+	for _, peer := range state.Peers {
+		if peer == nil {
+			continue
+		}
+		fmt.Printf("%d.%d.%d.%d %s\n",
+			nw[0], nw[1], nw[2], peer.PeerIP, peer.Name)
+	}
+	fmt.Println("")
+}
+
+// ----------------------------------------------------------------------------
+
+func fetchStatusReport(netName string) StatusReport {
+	client := http.Client{
+		Transport: &http.Transport{
+			Dial: func(_, _ string) (net.Conn, error) {
+				return net.Dial("unix", statusSocketPath(netName))
+			},
+		},
+		Timeout: 8 * time.Second,
+	}
+
+	getURL := "http://unix" + statusSocketPath(netName)
+	resp, err := client.Get(getURL)
+	if err != nil {
+		log.Fatalf("Failed to get response: %v", err)
+	}
+
+	report := StatusReport{}
+	if err := json.NewDecoder(resp.Body).Decode(&report); err != nil {
+		log.Fatalf("Failed to decode status report: %v", err)
+	}
+
+	return report
+}

peer/main_test.go

@@ -0,0 +1,5 @@
+package peer
+
+func newBuf() []byte {
+	return make([]byte, bufferSize)
+}

peer/mcreader.go

@@ -0,0 +1,47 @@
+package peer
+
+import (
+	"log"
+	"net"
+	"time"
+)
+
+func RunMCReader(g Globals) {
+	for {
+		runMCReaderInner(g)
+		time.Sleep(broadcastErrorTimeoutInterval)
+	}
+}
+
+func runMCReaderInner(g Globals) {
+	var (
+		buf  = make([]byte, bufferSize)
+		logf = func(s string, args ...any) {
+			log.Printf("[MCReader] "+s, args...)
+		}
+	)
+
+	conn, err := net.ListenMulticastUDP("udp", nil, multicastAddr)
+	if err != nil {
+		logf("Failed to bind to multicast address: %v", err)
+		return
+	}
+
+	for {
+		conn.SetReadDeadline(time.Now().Add(32 * time.Second))
+		n, remoteAddr, err := conn.ReadFromUDPAddrPort(buf[:bufferSize])
+		if err != nil {
+			logf("Failed to read from UDP port): %v", err)
+			return
+		}
+
+		buf = buf[:n]
+		h, ok := headerFromLocalDiscoveryPacket(buf)
+		if !ok {
+			logf("Failed to open discovery packet?")
+			continue
+		}
+
+		g.RemotePeers[h.SourceIP].Load().HandleLocalDiscoveryPacket(h, remoteAddr, buf)
+	}
+}

peer/mcreader_test.go

@@ -0,0 +1,132 @@
+package peer
+
+/*
+type mcMockConn struct {
+	packets chan []byte
+}
+
+func newMCMockConn() *mcMockConn {
+	return &mcMockConn{make(chan []byte, 32)}
+}
+
+func (c *mcMockConn) WriteToUDP(in []byte, addr *net.UDPAddr) (int, error) {
+	c.packets <- bytes.Clone(in)
+	return len(in), nil
+}
+
+func (c *mcMockConn) ReadFromUDPAddrPort(b []byte) (n int, addr netip.AddrPort, err error) {
+	buf := <-c.packets
+	b = b[:len(buf)]
+	copy(b, buf)
+	return len(b), netip.AddrPort{}, nil
+}
+
+func TestMCReader(t *testing.T) {
+	keys := generateKeys()
+	super := &mockControlMsgHandler{}
+	conn := newMCMockConn()
+
+	peers := [256]*atomic.Pointer[RemotePeer]{}
+	peer := &RemotePeer{
+		IP:         1,
+		Up:         true,
+		PubSignKey: keys.PubSignKey,
+	}
+	peers[1] = &atomic.Pointer[RemotePeer]{}
+	peers[1].Store(peer)
+
+	w := newMCWriter(conn, 1, keys.PrivSignKey)
+	r := newMCReader(conn, super, peers)
+
+	w.SendLocalDiscovery()
+	r.handleNextPacket()
+
+	if len(super.Messages) != 1 {
+		t.Fatal(super.Messages)
+	}
+	msg, ok := super.Messages[0].(controlMsg[PacketLocalDiscovery])
+	if !ok || msg.SrcIP != 1 {
+		t.Fatal(ok, msg)
+	}
+}
+
+func TestMCReader_noHeader(t *testing.T) {
+	keys := generateKeys()
+	super := &mockControlMsgHandler{}
+	conn := newMCMockConn()
+
+	peers := [256]*atomic.Pointer[RemotePeer]{}
+	peer := &RemotePeer{
+		IP:         1,
+		Up:         true,
+		PubSignKey: keys.PubSignKey,
+	}
+	peers[1] = &atomic.Pointer[RemotePeer]{}
+	peers[1].Store(peer)
+
+	r := newMCReader(conn, super, peers)
+	conn.WriteToUDP([]byte("0123546789"), nil)
+	r.handleNextPacket()
+
+	if len(super.Messages) != 0 {
+		t.Fatal(super.Messages)
+	}
+}
+
+func TestMCReader_noPeer(t *testing.T) {
+	keys := generateKeys()
+	super := &mockControlMsgHandler{}
+	conn := newMCMockConn()
+
+	peers := [256]*atomic.Pointer[RemotePeer]{}
+	peer := &RemotePeer{
+		IP:         1,
+		Up:         true,
+		PubSignKey: keys.PubSignKey,
+	}
+	peers[1] = &atomic.Pointer[RemotePeer]{}
+	peers[2] = &atomic.Pointer[RemotePeer]{}
+	peers[1].Store(peer)
+
+	w := newMCWriter(conn, 2, keys.PrivSignKey)
+	r := newMCReader(conn, super, peers)
+
+	w.SendLocalDiscovery()
+	r.handleNextPacket()
+
+	if len(super.Messages) != 0 {
+		t.Fatal(super.Messages)
+	}
+}
+
+func TestMCReader_badSignature(t *testing.T) {
+	keys := generateKeys()
+	super := &mockControlMsgHandler{}
+	conn := newMCMockConn()
+
+	peers := [256]*atomic.Pointer[RemotePeer]{}
+	peer := &RemotePeer{
+		IP:         1,
+		Up:         true,
+		PubSignKey: keys.PubSignKey,
+	}
+	peers[1] = &atomic.Pointer[RemotePeer]{}
+	peers[1].Store(peer)
+
+	w := newMCWriter(conn, 1, keys.PrivSignKey)
+	w.SendLocalDiscovery()
+
+	// Break signing.
+	packet := <-conn.packets
+	packet[0]++
+	conn.packets <- packet
+
+	r := newMCReader(conn, super, peers)
+
+	r.handleNextPacket()
+
+	if len(super.Messages) != 0 {
+		t.Fatal(super.Messages)
+	}
+}
+*/

peer/mcwriter.go

@@ -0,0 +1,54 @@
+package peer
+
+import (
+	"log"
+	"net"
+	"time"
+
+	"golang.org/x/crypto/nacl/sign"
+)
+
+func createLocalDiscoveryPacket(localIP byte, signingKey []byte) []byte {
+	h := Header{
+		SourceIP: localIP,
+		DestIP:   255,
+	}
+	buf := make([]byte, headerSize)
+	h.Marshal(buf)
+	out := make([]byte, headerSize+signingOverhead)
+	return sign.Sign(out[:0], buf, (*[64]byte)(signingKey))
+}
+
+func headerFromLocalDiscoveryPacket(pkt []byte) (h Header, ok bool) {
+	if len(pkt) != headerSize+signingOverhead {
+		return
+	}
+
+	h.Parse(pkt[signingOverhead:])
+	ok = true
+	return
+}
+
+func verifyLocalDiscoveryPacket(pkt, buf []byte, pubSignKey []byte) bool {
+	_, ok := sign.Open(buf[:0], pkt, (*[32]byte)(pubSignKey))
+	return ok
+}
+
+// ----------------------------------------------------------------------------
+
+func RunMCWriter(localIP byte, signingKey []byte) {
+	discoveryPacket := createLocalDiscoveryPacket(localIP, signingKey)
+
+	conn, err := net.ListenMulticastUDP("udp", nil, multicastAddr)
+	if err != nil {
+		log.Fatalf("[MCWriter] Failed to bind to multicast address: %v", err)
+	}
+
+	for range time.Tick(broadcastInterval) {
+		log.Printf("[MCWriter] Broadcasting on %v...", multicastAddr)
+		_, err := conn.WriteToUDP(discoveryPacket, multicastAddr)
+		if err != nil {
+			log.Printf("[MCWriter] Failed to write multicast: %v", err)
+		}
+	}
+}

peer/mcwriter_test.go

@@ -0,0 +1,98 @@
+package peer
+
+/*
+// ----------------------------------------------------------------------------
+
+// Testing that we can create and verify a local discovery packet.
+func TestVerifyLocalDiscoveryPacket_valid(t *testing.T) {
+	keys := generateKeys()
+
+	created := createLocalDiscoveryPacket(55, keys.PrivSignKey)
+
+	header, ok := headerFromLocalDiscoveryPacket(created)
+	if !ok {
+		t.Fatal(ok)
+	}
+	if header.SourceIP != 55 || header.DestIP != 255 {
+		t.Fatal(header)
+	}
+
+	if !verifyLocalDiscoveryPacket(created, make([]byte, 1024), keys.PubSignKey) {
+		t.Fatal("Not valid")
+	}
+}
+
+// Testing that we don't try to parse short packets.
+func TestVerifyLocalDiscoveryPacket_tooShort(t *testing.T) {
+	keys := generateKeys()
+
+	created := createLocalDiscoveryPacket(55, keys.PrivSignKey)
+
+	_, ok := headerFromLocalDiscoveryPacket(created[:len(created)-1])
+	if ok {
+		t.Fatal(ok)
+	}
+}
+
+// Testing that modifying a packet makes it invalid.
+func TestVerifyLocalDiscoveryPacket_invalid(t *testing.T) {
+	keys := generateKeys()
+
+	created := createLocalDiscoveryPacket(55, keys.PrivSignKey)
+	buf := make([]byte, 1024)
+	for i := range created {
+		modified := bytes.Clone(created)
+		modified[i]++
+		if verifyLocalDiscoveryPacket(modified, buf, keys.PubSignKey) {
+			t.Fatal("Verification should have failed.")
+		}
+	}
+}
+
+// ----------------------------------------------------------------------------
+
+type testUDPWriter struct {
+	written [][]byte
+}
+
+func (w *testUDPWriter) WriteToUDP(b []byte, addr *net.UDPAddr) (int, error) {
+	w.written = append(w.written, bytes.Clone(b))
+	return len(b), nil
+}
+
+func (w *testUDPWriter) Written() [][]byte {
+	out := w.written
+	w.written = [][]byte{}
+	return out
+}
+
+// ----------------------------------------------------------------------------
+
+// Testing that the mcWriter sends local discovery packets as expected.
+func TestMCWriter_SendLocalDiscovery(t *testing.T) {
+	keys := generateKeys()
+	writer := &testUDPWriter{}
+
+	mcw := newMCWriter(writer, 42, keys.PrivSignKey)
+	mcw.SendLocalDiscovery()
+
+	out := writer.Written()
+	if len(out) != 1 {
+		t.Fatal(out)
+	}
+
+	pkt := out[0]
+
+	header, ok := headerFromLocalDiscoveryPacket(pkt)
+	if !ok {
+		t.Fatal(ok)
+	}
+	if header.SourceIP != 42 || header.DestIP != 255 {
+		t.Fatal(header)
+	}
+
+	if !verifyLocalDiscoveryPacket(pkt, make([]byte, 1024), keys.PubSignKey) {
+		t.Fatal("Verification should succeed.")
+	}
+}
+*/

peer/mock-iface_test.go

@@ -0,0 +1,31 @@
+package peer
+
+import "bytes"
+
+type TestIFace struct {
+	out *bytes.Buffer // Toward the network.
+	in  *bytes.Buffer // From the network
+}
+
+func NewTestIFace() *TestIFace {
+	return &TestIFace{
+		out: &bytes.Buffer{},
+		in:  &bytes.Buffer{},
+	}
+}
+
+func (iface *TestIFace) Write(b []byte) (int, error) {
+	return iface.in.Write(b)
+}
+
+func (iface *TestIFace) Read(b []byte) (int, error) {
+	return iface.out.Read(b)
+}
+
+func (iface *TestIFace) UserWrite(b []byte) (int, error) {
+	return iface.out.Write(b)
+}
+
+func (iface *TestIFace) UserRead(b []byte) (int, error) {
+	return iface.in.Read(b)
+}

peer/mock-network_test.go

@@ -0,0 +1,80 @@
+package peer
+
+import (
+	"bytes"
+	"net"
+	"net/netip"
+	"sync"
+)
+
+type TestPacket struct {
+	Addr netip.AddrPort
+	Data []byte
+}
+
+type TestNetwork struct {
+	lock    sync.Mutex
+	packets map[netip.AddrPort]chan TestPacket
+}
+
+func NewTestNetwork() *TestNetwork {
+	return &TestNetwork{packets: map[netip.AddrPort]chan TestPacket{}}
+}
+
+func (n *TestNetwork) NewUDPConn(localAddr netip.AddrPort) *TestUDPConn {
+	n.lock.Lock()
+	defer n.lock.Unlock()
+	if _, ok := n.packets[localAddr]; !ok {
+		n.packets[localAddr] = make(chan TestPacket, 1024)
+	}
+	return &TestUDPConn{
+		addr:    localAddr,
+		n:       n,
+		packets: n.packets[localAddr],
+	}
+}
+
+func (n *TestNetwork) write(b []byte, from, to netip.AddrPort) {
+	n.lock.Lock()
+	defer n.lock.Unlock()
+	if _, ok := n.packets[to]; !ok {
+		n.packets[to] = make(chan TestPacket, 1024)
+	}
+	n.packets[to] <- TestPacket{
+		Addr: from,
+		Data: bytes.Clone(b),
+	}
+}
+
+type TestUDPConn struct {
+	addr    netip.AddrPort
+	n       *TestNetwork
+	packets chan TestPacket
+}
+
+func (c *TestUDPConn) WriteToUDPAddrPort(b []byte, addr netip.AddrPort) (int, error) {
+	c.n.write(b, c.addr, addr)
+	return len(b), nil
+}
+
+func (c *TestUDPConn) WriteToUDP(b []byte, addr *net.UDPAddr) (int, error) {
+	return c.WriteToUDPAddrPort(b, addr.AddrPort())
+}
+
+func (c *TestUDPConn) ReadFromUDPAddrPort(b []byte) (n int, addr netip.AddrPort, err error) {
+	pkt := <-c.packets
+	b = b[:len(pkt.Data)]
+	copy(b, pkt.Data)
+	return len(b), pkt.Addr, nil
+}
+
+func (c *TestUDPConn) Packets() (out []TestPacket) {
+	for {
+		select {
+		case pkt := <-c.packets:
+			out = append(out, pkt)
+		default:
+			return
+		}
+	}
+}

peer/packets-util.go

@@ -1,18 +1,10 @@
-package node
+package peer
 
 import (
 	"net/netip"
-	"sync/atomic"
-	"time"
 	"unsafe"
 )
 
-var traceIDCounter uint64 = uint64(time.Now().Unix()<<30) + 1
-
-func newTraceID() uint64 {
-	return atomic.AddUint64(&traceIDCounter, 1)
-}
-
 // ----------------------------------------------------------------------------
 
 type binWriter struct {
@@ -63,12 +55,20 @@ func (w *binWriter) Int64(x int64) *binWriter {
 }
 
 func (w *binWriter) AddrPort(addrPort netip.AddrPort) *binWriter {
+	w.Bool(addrPort.IsValid())
 	addr := addrPort.Addr().As16()
 	copy(w.b[w.i:w.i+16], addr[:])
 	w.i += 16
 	return w.Uint16(addrPort.Port())
 }
 
+func (w *binWriter) AddrPort8(l [8]netip.AddrPort) *binWriter {
+	for _, addrPort := range l {
+		w.AddrPort(addrPort)
+	}
+	return w
+}
+
 func (w *binWriter) Build() []byte {
 	return w.b[:w.i]
 }
@@ -146,15 +146,34 @@ func (r *binReader) Int64(x *int64) *binReader {
 }
 
 func (r *binReader) AddrPort(x *netip.AddrPort) *binReader {
-	if !r.hasBytes(18) {
+	if !r.hasBytes(19) {
 		return r
 	}
+
+	var (
+		valid bool
+		port  uint16
+	)
+
+	r.Bool(&valid)
 	addr := netip.AddrFrom16(([16]byte)(r.b[r.i : r.i+16])).Unmap()
 	r.i += 16
 
-	var port uint16
 	r.Uint16(&port)
-	*x = netip.AddrPortFrom(addr, port)
+
+	if valid {
+		*x = netip.AddrPortFrom(addr, port)
+	} else {
+		*x = netip.AddrPort{}
+	}
+
+	return r
+}
+
+func (r *binReader) AddrPort8(x *[8]netip.AddrPort) *binReader {
+	for i := range x {
+		r.AddrPort(&x[i])
+	}
 	return r
 }
 

peer/packets-util_test.go

@@ -0,0 +1,76 @@
+package peer
+
+import (
+	"net/netip"
+	"reflect"
+	"testing"
+)
+
+func TestBinWriteRead_invalidAddrPort(t *testing.T) {
+	addr := netip.AddrPort{}
+	buf := make([]byte, 1024)
+	buf = newBinWriter(buf).
+		AddrPort(addr).
+		Build()
+
+	var addr2 netip.AddrPort
+	err := newBinReader(buf).
+		AddrPort(&addr2).
+		Error()
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if addr2.IsValid() {
+		t.Fatal(addr, addr2)
+	}
+}
+
+func TestBinWriteRead(t *testing.T) {
+	buf := make([]byte, 1024)
+
+	type Item struct {
+		Type     byte
+		TraceID  uint64
+		Addrs    [8]netip.AddrPort
+		DestAddr netip.AddrPort
+	}
+
+	in := Item{
+		1,
+		2,
+		[8]netip.AddrPort{},
+		netip.AddrPortFrom(netip.AddrFrom4([4]byte{1, 2, 3, 4}), 22),
+	}
+
+	in.Addrs[0] = netip.AddrPortFrom(netip.AddrFrom4([4]byte{0, 1, 2, 3}), 20)
+	in.Addrs[2] = netip.AddrPortFrom(netip.AddrFrom4([4]byte{2, 3, 4, 5}), 22)
+	in.Addrs[3] = netip.AddrPortFrom(netip.AddrFrom4([4]byte{2, 3, 4, 3}), 23)
+	in.Addrs[4] = netip.AddrPortFrom(netip.AddrFrom4([4]byte{2, 3, 4, 4}), 24)
+	in.Addrs[5] = netip.AddrPortFrom(netip.AddrFrom4([4]byte{2, 3, 4, 5}), 25)
+	in.Addrs[6] = netip.AddrPortFrom(netip.AddrFrom4([4]byte{2, 3, 4, 6}), 26)
+	in.Addrs[7] = netip.AddrPortFrom(netip.AddrFrom4([4]byte{7, 8, 9, 7}), 27)
+
+	buf = newBinWriter(buf).
+		Byte(in.Type).
+		Uint64(in.TraceID).
+		AddrPort(in.DestAddr).
+		AddrPort8(in.Addrs).
+		Build()
+
+	out := Item{}
+
+	err := newBinReader(buf).
+		Byte(&out.Type).
+		Uint64(&out.TraceID).
+		AddrPort(&out.DestAddr).
+		AddrPort8(&out.Addrs).
+		Error()
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if !reflect.DeepEqual(in, out) {
+		t.Fatal(in, out)
+	}
+}

peer/packets.go

@@ -0,0 +1,120 @@
+package peer
+
+import (
+	"net/netip"
+)
+
+const (
+	packetTypeSyn           = 1
+	packetTypeInit          = 2
+	packetTypeAck           = 3
+	packetTypeProbe         = 4
+	packetTypeAddrDiscovery = 5
+)
+
+// ----------------------------------------------------------------------------
+
+type packetInit struct {
+	TraceID uint64
+	Direct  bool
+	Version uint64
+}
+
+func (p packetInit) Marshal(buf []byte) []byte {
+	return newBinWriter(buf).
+		Byte(packetTypeInit).
+		Uint64(p.TraceID).
+		Bool(p.Direct).
+		Uint64(p.Version).
+		Build()
+}
+
+func parsePacketInit(buf []byte) (p packetInit, err error) {
+	err = newBinReader(buf[1:]).
+		Uint64(&p.TraceID).
+		Bool(&p.Direct).
+		Uint64(&p.Version).
+		Error()
+	return
+}
+
+// ----------------------------------------------------------------------------
+
+type packetSyn struct {
+	TraceID       uint64   // TraceID to match response w/ request.
+	SharedKey     [32]byte // Our shared key.
+	Direct        bool
+	PossibleAddrs [8]netip.AddrPort // Possible public addresses of the sender.
+}
+
+func (p packetSyn) Marshal(buf []byte) []byte {
+	return newBinWriter(buf).
+		Byte(packetTypeSyn).
+		Uint64(p.TraceID).
+		SharedKey(p.SharedKey).
+		Bool(p.Direct).
+		AddrPort8(p.PossibleAddrs).
+		Build()
+}
+
+func parsePacketSyn(buf []byte) (p packetSyn, err error) {
+	err = newBinReader(buf[1:]).
+		Uint64(&p.TraceID).
+		SharedKey(&p.SharedKey).
+		Bool(&p.Direct).
+		AddrPort8(&p.PossibleAddrs).
+		Error()
+	return
+}
+
+// ----------------------------------------------------------------------------
+
+type packetAck struct {
+	TraceID       uint64
+	ToAddr        netip.AddrPort
+	PossibleAddrs [8]netip.AddrPort // Possible public addresses of the sender.
+}
+
+func (p packetAck) Marshal(buf []byte) []byte {
+	return newBinWriter(buf).
+		Byte(packetTypeAck).
+		Uint64(p.TraceID).
+		AddrPort(p.ToAddr).
+		AddrPort8(p.PossibleAddrs).
+		Build()
+}
+
+func parsePacketAck(buf []byte) (p packetAck, err error) {
+	err = newBinReader(buf[1:]).
+		Uint64(&p.TraceID).
+		AddrPort(&p.ToAddr).
+		AddrPort8(&p.PossibleAddrs).
+		Error()
+	return
+}
+
+// ----------------------------------------------------------------------------
+
+// A probeReqPacket is sent from a client to a server to determine if direct
+// UDP communication can be used.
+type packetProbe struct {
+	TraceID uint64
+}
+
+func (p packetProbe) Marshal(buf []byte) []byte {
+	return newBinWriter(buf).
+		Byte(packetTypeProbe).
+		Uint64(p.TraceID).
+		Build()
+}
+
+func parsePacketProbe(buf []byte) (p packetProbe, err error) {
+	err = newBinReader(buf[1:]).
+		Uint64(&p.TraceID).
+		Error()
+	return
+}
+
+// ----------------------------------------------------------------------------
+
+type packetLocalDiscovery struct{}

peer/packets_test.go

@@ -0,0 +1,64 @@
+package peer
+
+import (
+	"crypto/rand"
+	"net/netip"
+	"reflect"
+	"testing"
+)
+
+func TestSynPacket(t *testing.T) {
+	p := packetSyn{
+		TraceID: 2342342345,
+		Direct:  true,
+	}
+	rand.Read(p.SharedKey[:])
+
+	p.PossibleAddrs[0] = netip.AddrPortFrom(netip.AddrFrom4([4]byte{1, 2, 3, 4}), 234)
+	p.PossibleAddrs[1] = netip.AddrPortFrom(netip.AddrFrom4([4]byte{2, 2, 3, 4}), 12399)
+	p.PossibleAddrs[2] = netip.AddrPortFrom(netip.AddrFrom4([4]byte{3, 2, 3, 4}), 60000)
+
+	buf := p.Marshal(newBuf())
+	p2, err := parsePacketSyn(buf)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if !reflect.DeepEqual(p, p2) {
+		t.Fatal(p2)
+	}
+}
+
+func TestAckPacket(t *testing.T) {
+	p := packetAck{
+		TraceID: 123213,
+		ToAddr:  netip.AddrPortFrom(netip.AddrFrom4([4]byte{1, 2, 3, 4}), 234),
+	}
+
+	p.PossibleAddrs[0] = netip.AddrPortFrom(netip.AddrFrom4([4]byte{8, 2, 3, 4}), 100)
+	p.PossibleAddrs[1] = netip.AddrPortFrom(netip.AddrFrom4([4]byte{2, 2, 3, 4}), 12399)
+	p.PossibleAddrs[2] = netip.AddrPortFrom(netip.AddrFrom4([4]byte{3, 2, 3, 4}), 60000)
+
+	buf := p.Marshal(newBuf())
+	p2, err := parsePacketAck(buf)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if !reflect.DeepEqual(p, p2) {
+		t.Fatal(p2)
+	}
+}
+
+func TestProbePacket(t *testing.T) {
+	p := packetProbe{
+		TraceID: 12345,
+	}
+
+	buf := p.Marshal(newBuf())
+	p2, err := parsePacketProbe(buf)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if !reflect.DeepEqual(p, p2) {
+		t.Fatal(p2)
+	}
+}

peer/peer.go

@@ -0,0 +1,201 @@
+package peer
+
+import (
+	"bytes"
+	"encoding/json"
+	"fmt"
+	"io"
+	"log"
+	"math"
+	"net"
+	"net/http"
+	"net/netip"
+	"net/url"
+	"os"
+	"vppn/m"
+
+	"git.crumpington.com/lib/go/flock"
+)
+
+type peerMain struct {
+	Globals
+	ifReader   *IFReader
+	connReader *ConnReader
+	hubPoller  *HubPoller
+	lockFile   *os.File
+}
+
+func newPeerMain(args mainArgs) *peerMain {
+	logf := func(s string, args ...any) {
+		log.Printf("[Main] "+s, args...)
+	}
+
+	if err := os.MkdirAll(configDir(args.NetName), 0700); err != nil {
+		log.Fatalf("Failed to create config directory: %v", err)
+	}
+
+	lockFile, err := flock.TryLock(lockFilePath(args.NetName))
+	if err != nil {
+		log.Fatalf("Failed to open lock file: %v", err)
+	}
+	if lockFile == nil {
+		log.Fatalf("Failed to obtain file lock.")
+	}
+
+	config, err := loadPeerConfig(args.NetName)
+	if err != nil {
+		logf("Failed to load configuration: %v", err)
+		logf("Initializing...")
+		initPeerWithHub(args)
+
+		config, err = loadPeerConfig(args.NetName)
+		if err != nil {
+			log.Fatalf("Failed to load configuration: %v", err)
+		}
+	}
+
+	state, err := loadNetworkState(args.NetName)
+	if err != nil {
+		log.Fatalf("Failed to load network state: %v", err)
+	}
+
+	startupCount, err := loadStartupCount(args.NetName)
+	if err != nil {
+		if !os.IsNotExist(err) {
+			log.Fatalf("Failed to load startup count: %v", err)
+		}
+	}
+
+	if startupCount.Count == math.MaxUint16 {
+		log.Fatalf("Startup counter overflow.")
+	}
+	startupCount.Count += 1
+
+	if err := storeStartupCount(args.NetName, startupCount); err != nil {
+		log.Fatalf("Failed to write startup count: %v", err)
+	}
+
+	iface, err := openInterface(config.Network, config.LocalPeerIP, args.NetName)
+	if err != nil {
+		log.Fatalf("Failed to open interface: %v", err)
+	}
+
+	localPeer := state.Peers[config.LocalPeerIP]
+
+	myAddr, err := net.ResolveUDPAddr("udp", fmt.Sprintf(":%d", localPeer.Port))
+	if err != nil {
+		log.Fatalf("Failed to resolve UDP address: %v", err)
+	}
+
+	logf("Listening on %v...", myAddr)
+	conn, err := net.ListenUDP("udp", myAddr)
+	if err != nil {
+		log.Fatalf("Failed to open UDP port: %v", err)
+	}
+
+	conn.SetReadBuffer(1024 * 1024 * 8)
+	conn.SetWriteBuffer(1024 * 1024 * 8)
+
+	var localAddr netip.AddrPort
+	ip, localAddrValid := netip.AddrFromSlice(localPeer.PublicIP)
+	if localAddrValid {
+		localAddr = netip.AddrPortFrom(ip, localPeer.Port)
+	}
+
+	g := NewGlobals(config, startupCount, localAddr, conn, iface)
+
+	hubPoller, err := NewHubPoller(g, args.NetName, args.HubAddress, args.APIKey)
+	if err != nil {
+		log.Fatalf("Failed to create hub poller: %v", err)
+	}
+
+	// Start status server.
+	go runStatusServer(g, statusSocketPath(args.NetName))
+
+	return &peerMain{
+		Globals:    g,
+		ifReader:   NewIFReader(g),
+		connReader: NewConnReader(g, conn),
+		hubPoller:  hubPoller,
+		lockFile:   lockFile,
+	}
+}
+
+func (p *peerMain) Run() {
+	for i := range p.RemotePeers {
+		remote := p.RemotePeers[i].Load()
+		go newRemoteFSM(remote).Run()
+	}
+
+	go p.ifReader.Run()
+	go p.connReader.Run()
+
+	if !p.LocalAddrValid {
+		go RunMCWriter(p.LocalPeerIP, p.PrivSignKey)
+		go RunMCReader(p.Globals)
+	}
+
+	go p.hubPoller.Run()
+
+	select {}
+}
+
+func initPeerWithHub(args mainArgs) {
+	keys := generateKeys()
+
+	initURL, err := url.Parse(args.HubAddress)
+	if err != nil {
+		log.Fatalf("Failed to parse hub URL: %v", err)
+	}
+	initURL.Path = "/peer/init/"
+
+	initArgs := m.PeerInitArgs{
+		EncPubKey:  keys.PubKey,
+		PubSignKey: keys.PubSignKey,
+	}
+
+	buf := &bytes.Buffer{}
+	if err := json.NewEncoder(buf).Encode(initArgs); err != nil {
+		log.Fatalf("Failed to encode init args: %v", err)
+	}
+
+	req, err := http.NewRequest(http.MethodPost, initURL.String(), buf)
+	if err != nil {
+		log.Fatalf("Failed to construct request: %v", err)
+	}
+	req.SetBasicAuth("", args.APIKey)
+
+	resp, err := http.DefaultClient.Do(req)
+	if err != nil {
+		log.Fatalf("Failed to init with hub: %v", err)
+	}
+	defer resp.Body.Close()
+
+	data, err := io.ReadAll(resp.Body)
+	if err != nil {
+		log.Fatalf("Failed to read response body: %v", err)
+	}
+
+	initResp := m.PeerInitResp{}
+	if err := json.Unmarshal(data, &initResp); err != nil {
+		log.Fatalf("Failed to parse configuration: %v\n%s", err, data)
+	}
+
+	config := LocalConfig{}
+	config.LocalPeerIP = initResp.PeerIP
+	config.Network = initResp.Network
+	config.PubKey = keys.PubKey
+	config.PrivKey = keys.PrivKey
+	config.PubSignKey = keys.PubSignKey
+	config.PrivSignKey = keys.PrivSignKey
+
+	if err := storeNetworkState(args.NetName, initResp.NetworkState); err != nil {
+		log.Fatalf("Failed to store network state: %v", err)
+	}
+
+	if err := storePeerConfig(args.NetName, config); err != nil {
+		log.Fatalf("Failed to store configuration: %v", err)
+	}
+
+	log.Print("Initialization successful.")
+}

peer/peerfsm.dot

@@ -0,0 +1,28 @@
+digraph d {
+        disconnected -> peerUpdating;
+        peerUpdating -> disconnected;
+        peerUpdating -> server;
+        peerUpdating -> clientInit;
+        server -> peerUpdating;
+        clientInit -> peerUpdating;
+        clientInit -> clientInit;
+        clientInit -> client;
+        client -> clientInit;
+        client -> peerUpdating;
+
+        clientInitializing -> clientSyncing;
+        clientSyncing -> clientInitializing;
+        clientSyncing -> clientUpIndirect;
+        clientSyncing -> clientUpDirect;
+        clientUpIndirect -> clientUpDirect;
+        clientUpIndirect -> clientInitializing;
+        clientUpDirect -> clientInitializing;
+
+        serverInitializing -> serverSyncing;
+        serverSyncing -> serverInitializing;
+        serverSyncing -> serverUpIndirect;
+        serverSyncing -> serverUpDirect;
+        serverUpIndirect -> serverUpDirect;
+        serverUpIndirect -> serverInitializing;
+        serverUpDirect -> serverInitializing;
+}

peer/pubaddrs.go

@@ -0,0 +1,86 @@
+package peer
+
+import (
+	"net/netip"
+	"sort"
+	"sync"
+	"time"
+)
+
+type pubAddrStore struct {
+	lock      sync.Mutex
+	localPub  bool
+	localAddr netip.AddrPort
+	lastSeen  map[netip.AddrPort]time.Time
+	addrList  []netip.AddrPort
+}
+
+func newPubAddrStore(localAddr netip.AddrPort) *pubAddrStore {
+	return &pubAddrStore{
+		localPub:  localAddr.IsValid(),
+		localAddr: localAddr,
+		lastSeen:  map[netip.AddrPort]time.Time{},
+		addrList:  make([]netip.AddrPort, 0, 32),
+	}
+}
+
+func (store *pubAddrStore) Store(addr netip.AddrPort) {
+	if store.localPub {
+		return
+	}
+
+	if !addr.IsValid() {
+		return
+	}
+
+	if addr.Addr().IsPrivate() {
+		return
+	}
+
+	store.lock.Lock()
+	defer store.lock.Unlock()
+
+	if _, exists := store.lastSeen[addr]; !exists {
+		store.addrList = append(store.addrList, addr)
+	}
+	store.lastSeen[addr] = time.Now()
+	store.sort()
+}
+
+func (store *pubAddrStore) Get() (addrs [8]netip.AddrPort) {
+	store.lock.Lock()
+	defer store.lock.Unlock()
+
+	store.clean()
+
+	if store.localPub {
+		addrs[0] = store.localAddr
+		return
+	}
+
+	copy(addrs[:], store.addrList)
+	return
+}
+
+func (store *pubAddrStore) clean() {
+	if store.localPub {
+		return
+	}
+
+	for ip, lastSeen := range store.lastSeen {
+		if time.Since(lastSeen) > timeoutInterval {
+			delete(store.lastSeen, ip)
+		}
+	}
+	store.addrList = store.addrList[:0]
+	for ip := range store.lastSeen {
+		store.addrList = append(store.addrList, ip)
+	}
+	store.sort()
+}
+
+func (store *pubAddrStore) sort() {
+	sort.Slice(store.addrList, func(i, j int) bool {
+		return store.lastSeen[store.addrList[j]].Before(store.lastSeen[store.addrList[i]])
+	})
+}

peer/pubaddrs_test.go

@@ -0,0 +1,29 @@
+package peer
+
+import (
+	"net/netip"
+	"testing"
+	"time"
+)
+
+func TestPubAddrStore(t *testing.T) {
+	s := newPubAddrStore(netip.AddrPort{})
+
+	l := []netip.AddrPort{
+		netip.AddrPortFrom(netip.AddrFrom4([4]byte{0, 1, 2, 3}), 20),
+		netip.AddrPortFrom(netip.AddrFrom4([4]byte{1, 1, 2, 3}), 21),
+		netip.AddrPortFrom(netip.AddrFrom4([4]byte{2, 1, 2, 3}), 22),
+	}
+
+	for i := range l {
+		s.Store(l[i])
+		time.Sleep(time.Millisecond)
+	}
+
+	s.clean()
+
+	l2 := s.Get()
+	if l2[0] != l[2] || l2[1] != l[1] || l2[2] != l[0] {
+		t.Fatal(l, l2)
+	}
+}

peer/relayhandler.go

@@ -0,0 +1,54 @@
+package peer
+
+import (
+	"log"
+	"sync"
+	"sync/atomic"
+)
+
+type relayHandler struct {
+	lock   sync.Mutex
+	relays map[byte]*Remote
+	relay  atomic.Pointer[Remote]
+}
+
+func newRelayHandler() *relayHandler {
+	return &relayHandler{
+		relays: make(map[byte]*Remote, 256),
+	}
+}
+
+func (h *relayHandler) Add(r *Remote) {
+	h.lock.Lock()
+	defer h.lock.Unlock()
+
+	h.relays[r.RemotePeerIP] = r
+
+	if h.relay.Load() == nil {
+		log.Printf("Setting Relay: %v", r.conf().Peer.Name)
+		h.relay.Store(r)
+	}
+}
+
+func (h *relayHandler) Remove(r *Remote) {
+	h.lock.Lock()
+	defer h.lock.Unlock()
+
+	log.Printf("Removing relay %d...", r.RemotePeerIP)
+	delete(h.relays, r.RemotePeerIP)
+
+	if h.relay.Load() == r {
+		// Remove current relay.
+		h.relay.Store(nil)
+
+		// Find new relay.
+		for _, r := range h.relays {
+			h.relay.Store(r)
+			break
+		}
+	}
+}
+
+func (h *relayHandler) Load() *Remote {
+	return h.relay.Load()
+}

peer/remote.go

@@ -0,0 +1,351 @@
+package peer
+
+import (
+	"fmt"
+	"log"
+	"net/netip"
+	"strings"
+	"sync/atomic"
+	"vppn/m"
+)
+
+// ----------------------------------------------------------------------------
+// The remoteConfig is the shared, immutable configuration for a remote
+// peer. It's read and written atomically. See remote.config.
+// ----------------------------------------------------------------------------
+
+type remoteConfig struct {
+	Up            bool           // True if peer is up and we can send data.
+	Server        bool           // True if role is server.
+	Direct        bool           // True if this is a direct connection.
+	DirectAddr    netip.AddrPort // Remote address if directly connected.
+	ControlCipher *controlCipher
+	DataCipher    *dataCipher
+	Peer          *m.Peer
+}
+
+// CanRelay returns true if the remote configuration is able to relay packets.
+// to other hosts.
+func (rc remoteConfig) CanRelay() bool {
+	return rc.Up && rc.Direct && rc.Peer.Relay
+}
+
+// A Remote represents a remote peer and contains functions for handling
+// incoming control, data, and multicast packets, peer udpates, as well as
+// sending, forwarding, and relaying packets.
+type Remote struct {
+	Globals
+	RemotePeerIP byte // Immutable.
+
+	dupCheck    *dupCheck
+	sendCounter uint64 // init to startupCount << 48. Atomic access only.
+
+	// config should be accessed via conf() and updateConf(...) methods.
+	config   atomic.Pointer[remoteConfig]
+	messages chan any
+}
+
+func newRemote(g Globals, remotePeerIP byte) *Remote {
+	r := &Remote{
+		Globals:      g,
+		RemotePeerIP: remotePeerIP,
+		dupCheck:     newDupCheck(0),
+		sendCounter:  (uint64(g.StartupCount) << 48) + 1,
+		messages:     make(chan any, 8),
+	}
+	r.config.Store(&remoteConfig{})
+	return r
+}
+
+// ----------------------------------------------------------------------------
+
+func (r *Remote) conf() remoteConfig {
+	return *(r.config.Load())
+}
+
+func (r *Remote) updateConf(conf remoteConfig) {
+	old := r.config.Load()
+	r.config.Store(&conf)
+
+	if !old.CanRelay() && conf.CanRelay() {
+		r.RelayHandler.Add(r)
+	}
+
+	if old.CanRelay() && !conf.CanRelay() {
+		r.RelayHandler.Remove(r)
+	}
+}
+
+// ----------------------------------------------------------------------------
+
+func (r *Remote) sendUDP(b []byte, addr netip.AddrPort) {
+	if _, err := r.SendUDP(b, addr); err != nil {
+		r.logf("Failed to send UDP packet: %v", err)
+	}
+}
+
+// ----------------------------------------------------------------------------
+
+func (r *Remote) encryptData(conf remoteConfig, destIP byte, packet []byte) []byte {
+	h := Header{
+		StreamID: dataStreamID,
+		Counter:  atomic.AddUint64(&r.sendCounter, 1),
+		SourceIP: r.Globals.LocalPeerIP,
+		DestIP:   destIP,
+	}
+	return conf.DataCipher.Encrypt(h, packet, packet[len(packet):cap(packet)])
+}
+
+func (r *Remote) encryptControl(conf remoteConfig, packet []byte) []byte {
+	h := Header{
+		StreamID: controlStreamID,
+		Counter:  atomic.AddUint64(&r.sendCounter, 1),
+		SourceIP: r.LocalPeerIP,
+		DestIP:   r.RemotePeerIP,
+	}
+	return conf.ControlCipher.Encrypt(h, packet, packet[len(packet):cap(packet)])
+}
+
+func (r *Remote) Status() (RemoteStatus, bool) {
+	conf := r.conf()
+	if conf.Peer == nil {
+		return RemoteStatus{}, false
+	}
+
+	return RemoteStatus{
+		PeerIP:     conf.Peer.PeerIP,
+		Up:         conf.Up,
+		Name:       conf.Peer.Name,
+		PublicIP:   conf.Peer.PublicIP,
+		Port:       conf.Peer.Port,
+		Relay:      conf.Peer.Relay,
+		Server:     conf.Server,
+		Direct:     conf.Direct,
+		DirectAddr: conf.DirectAddr,
+	}, true
+}
+
+// ----------------------------------------------------------------------------
+
+// SendDataTo sends a data packet to the remote, called by the IFReader.
+func (r *Remote) SendDataTo(data []byte) {
+	conf := r.conf()
+	if !conf.Up {
+		r.logf("Cannot send: link down")
+		return
+	}
+
+	// Direct:
+
+	if conf.Direct {
+		r.sendUDP(r.encryptData(conf, conf.Peer.PeerIP, data), conf.DirectAddr)
+		return
+	}
+
+	// Relayed:
+	relay := r.RelayHandler.Load()
+
+	if relay == nil {
+		r.logf("Connot send: no relay")
+		return
+	}
+
+	relay.relayData(conf.Peer.PeerIP, r.encryptData(conf, conf.Peer.PeerIP, data))
+}
+
+func (r *Remote) relayData(toIP byte, enc []byte) {
+	conf := r.conf()
+	if !conf.Up || !conf.Direct {
+		r.logf("Cannot relay: not up or not a direct connection")
+		return
+	}
+	r.sendUDP(r.encryptData(conf, toIP, enc), conf.DirectAddr)
+}
+
+func (r *Remote) sendControl(conf remoteConfig, data []byte) {
+	// Direct:
+
+	if conf.Direct {
+		enc := r.encryptControl(conf, data)
+		r.sendUDP(enc, conf.DirectAddr)
+		return
+	}
+
+	// Relayed:
+
+	relay := r.RelayHandler.Load()
+
+	if relay == nil {
+		r.logf("Connot send: no relay")
+		return
+	}
+
+	relay.relayData(conf.Peer.PeerIP, r.encryptControl(conf, data))
+}
+
+func (r *Remote) sendControlToAddr(buf []byte, addr netip.AddrPort) {
+	enc := r.encryptControl(r.conf(), buf)
+	r.sendUDP(enc, addr)
+}
+
+func (r *Remote) forwardPacket(data []byte) {
+	conf := r.conf()
+	if !conf.Up || !conf.Direct {
+		r.logf("Cannot forward to %d: not a direct connection", conf.Peer.PeerIP)
+		return
+	}
+	r.sendUDP(data, conf.DirectAddr)
+}
+
+// ----------------------------------------------------------------------------
+
+// HandlePacket is called by the ConnReader to handle an incoming packet.
+func (r *Remote) HandlePacket(h Header, srcAddr netip.AddrPort, data []byte) {
+	switch h.StreamID {
+	case controlStreamID:
+		r.handleControlPacket(h, srcAddr, data)
+	case dataStreamID:
+		r.handleDataPacket(h, data)
+	default:
+		r.logf("Unknown stream ID: %d", h.StreamID)
+	}
+}
+
+// Handle a control packet. Decrypt, verify, etc.
+func (r *Remote) handleControlPacket(h Header, srcAddr netip.AddrPort, data []byte) {
+	conf := r.conf()
+	if conf.ControlCipher == nil {
+		r.logf("No control cipher")
+		return
+	}
+
+	dec, ok := conf.ControlCipher.Decrypt(data, data[len(data):cap(data)])
+	if !ok {
+		r.logf("Failed to decrypt control packet")
+		return
+	}
+
+	if r.dupCheck.IsDup(h.Counter) {
+		r.logf("Dropping control packet as duplicate: %d", h.Counter)
+		return
+	}
+
+	msg, err := parseControlMsg(h.SourceIP, srcAddr, dec)
+	if err != nil {
+		r.logf("Failed to parse control packet: %v", err)
+		return
+	}
+
+	select {
+	case r.messages <- msg:
+	default:
+		r.logf("Dropping control message")
+	}
+}
+
+func (r *Remote) handleDataPacket(h Header, data []byte) {
+	conf := r.conf()
+	if conf.DataCipher == nil {
+		return
+	}
+
+	dec, ok := conf.DataCipher.Decrypt(data, data[len(data):cap(data)])
+	if !ok {
+		r.logf("Failed to decrypt data packet")
+		return
+	}
+
+	if r.dupCheck.IsDup(h.Counter) {
+		r.logf("Dropping data packet as duplicate: %d", h.Counter)
+		return
+	}
+
+	// For local.
+	if h.DestIP == r.LocalPeerIP {
+		if _, err := r.IFace.Write(dec); err != nil {
+			// This could be a malformed packet from a peer, so we don't crash if it
+			// happens.
+			r.logf("Failed to write to interface: %v", err)
+		}
+		return
+	}
+
+	// Forward.
+	dest := r.RemotePeers[h.DestIP].Load()
+	dest.forwardPacket(dec)
+}
+
+// ----------------------------------------------------------------------------
+
+// HandleLocalDiscoveryPacket is called by the MCReader.
+func (r *Remote) HandleLocalDiscoveryPacket(h Header, srcAddr netip.AddrPort, data []byte) {
+	conf := r.conf()
+	if conf.Peer == nil {
+		r.logf("No peer for discovery packet.")
+		return
+	}
+
+	if conf.Peer.PubSignKey == nil {
+		r.logf("No signing key for discovery packet.")
+		return
+	}
+
+	if !verifyLocalDiscoveryPacket(data, data[len(data):cap(data)], conf.Peer.PubSignKey) {
+		r.logf("Invalid signature on discovery packet.")
+		return
+	}
+
+	msg := controlMsg[packetLocalDiscovery]{
+		SrcIP:   h.SourceIP,
+		SrcAddr: srcAddr,
+	}
+
+	select {
+	case r.messages <- msg:
+	default:
+		r.logf("Dropping discovery message.")
+	}
+}
+
+// ----------------------------------------------------------------------------
+
+// HandlePeerUpdate is called by the HubPoller when it gets a new version of
+// the associated peer configuration.
+func (r *Remote) HandlePeerUpdate(msg peerUpdateMsg) {
+	r.messages <- msg
+}
+
+// ----------------------------------------------------------------------------
+
+func (s *Remote) logf(format string, args ...any) {
+	conf := s.conf()
+
+	b := strings.Builder{}
+	name := ""
+	if conf.Peer != nil {
+		name = conf.Peer.Name
+	}
+	b.WriteString(fmt.Sprintf("%03d", s.RemotePeerIP))
+
+	b.WriteString(fmt.Sprintf("%30s: ", name))
+
+	if conf.Server {
+		b.WriteString("SERVER | ")
+	} else {
+		b.WriteString("CLIENT | ")
+	}
+
+	if conf.Direct {
+		b.WriteString("DIRECT  | ")
+	} else {
+		b.WriteString("RELAYED | ")
+	}
+
+	if conf.Up {
+		b.WriteString("UP   | ")
+	} else {
+		b.WriteString("DOWN | ")
+	}
+
+	log.Printf(b.String()+format, args...)
+}

peer/remotefsm.go

@@ -0,0 +1,448 @@
+package peer
+
+import (
+	"net/netip"
+	"time"
+	"vppn/m"
+)
+
+type stateFunc func(msg any) stateFunc
+
+type sentProbe struct {
+	SentAt time.Time
+	Addr   netip.AddrPort
+}
+
+type remoteFSM struct {
+	*Remote
+
+	pingTimer *time.Ticker
+	lastSeen  time.Time
+	traceID   uint64
+	probes    map[uint64]sentProbe
+
+	buf []byte
+}
+
+func newRemoteFSM(r *Remote) *remoteFSM {
+	fsm := &remoteFSM{
+		Remote:    r,
+		pingTimer: time.NewTicker(timeoutInterval),
+		probes:    map[uint64]sentProbe{},
+		buf:       make([]byte, bufferSize),
+	}
+	fsm.pingTimer.Stop()
+	return fsm
+}
+
+func (r *remoteFSM) Run() {
+	go func() {
+		for range r.pingTimer.C {
+			r.messages <- pingTimerMsg{}
+		}
+	}()
+	state := r.enterDisconnected()
+	for msg := range r.messages {
+		state = state(msg)
+	}
+}
+
+// ----------------------------------------------------------------------------
+
+func (r *remoteFSM) enterDisconnected() stateFunc {
+	r.updateConf(remoteConfig{})
+	return r.stateDisconnected
+}
+
+func (r *remoteFSM) stateDisconnected(iMsg any) stateFunc {
+	switch msg := iMsg.(type) {
+	case peerUpdateMsg:
+		return r.enterPeerUpdating(msg.Peer)
+	case controlMsg[packetInit]:
+		r.logf("Unexpected INIT")
+	case controlMsg[packetSyn]:
+		r.logf("Unexpected SYN")
+	case controlMsg[packetAck]:
+		r.logf("Unexpected ACK")
+	case controlMsg[packetProbe]:
+		r.logf("Unexpected probe")
+	case controlMsg[packetLocalDiscovery]:
+		// Ignore
+	case pingTimerMsg:
+		r.logf("Unexpected ping")
+	default:
+		r.logf("Ignoring message: %#v", iMsg)
+	}
+
+	return r.stateDisconnected
+}
+
+// ----------------------------------------------------------------------------
+
+func (r *remoteFSM) enterPeerUpdating(peer *m.Peer) stateFunc {
+	if peer == nil {
+		return r.enterDisconnected()
+	}
+
+	conf := remoteConfig{
+		Peer:          peer,
+		ControlCipher: newControlCipher(r.PrivKey, peer.PubKey),
+	}
+	r.updateConf(conf)
+
+	if _, isValid := netip.AddrFromSlice(peer.PublicIP); isValid {
+		if r.LocalAddrValid && r.LocalPeerIP < peer.PeerIP {
+			return r.enterServer()
+		}
+		return r.enterClientInit()
+	}
+
+	if r.LocalAddrValid || r.LocalPeerIP < peer.PeerIP {
+		return r.enterServer()
+	}
+
+	return r.enterClientInit()
+}
+
+// ----------------------------------------------------------------------------
+
+func (r *remoteFSM) enterServer() stateFunc {
+
+	conf := r.conf()
+	conf.Server = true
+	r.updateConf(conf)
+	r.logf("==> Server")
+
+	r.pingTimer.Reset(pingInterval)
+	r.lastSeen = time.Now()
+	return r.stateServer
+}
+
+func (r *remoteFSM) stateServer(iMsg any) stateFunc {
+	switch msg := iMsg.(type) {
+	case peerUpdateMsg:
+		return r.enterPeerUpdating(msg.Peer)
+	case controlMsg[packetInit]:
+		r.stateServer_onInit(msg)
+	case controlMsg[packetSyn]:
+		r.stateServer_onSyn(msg)
+	case controlMsg[packetAck]:
+		r.logf("Unexpected ACK")
+	case controlMsg[packetProbe]:
+		r.stateServer_onProbe(msg)
+	case controlMsg[packetLocalDiscovery]:
+		// Ignore
+	case pingTimerMsg:
+		r.stateServer_onPingTimer()
+	default:
+		r.logf("Unexpected message: %#v", iMsg)
+	}
+
+	return r.stateServer
+}
+
+func (r *remoteFSM) stateServer_onInit(msg controlMsg[packetInit]) {
+	conf := r.conf()
+	conf.Up = false
+	conf.Direct = msg.Packet.Direct
+	conf.DirectAddr = msg.SrcAddr
+	r.updateConf(conf)
+
+	init := packetInit{
+		TraceID: msg.Packet.TraceID,
+		Direct:  conf.Direct,
+		Version: version,
+	}
+
+	// Reset traceID to force state update on SYN.
+	r.traceID = 0
+	r.sendControl(conf, init.Marshal(r.buf))
+}
+
+func (r *remoteFSM) stateServer_onSyn(msg controlMsg[packetSyn]) {
+	r.lastSeen = time.Now()
+	p := msg.Packet
+
+	conf := r.conf()
+
+	// New trace ID => Update the route configuration.
+	if p.TraceID != r.traceID {
+		r.traceID = p.TraceID
+
+		conf.Up = true
+		conf.Direct = p.Direct
+		conf.DirectAddr = msg.SrcAddr
+
+		conf.DataCipher = newDataCipherFromKey(p.SharedKey)
+
+		r.updateConf(conf)
+		r.logf("Got SYN.")
+	}
+
+	r.sendControl(conf, packetAck{
+		TraceID:       p.TraceID,
+		ToAddr:        conf.DirectAddr,
+		PossibleAddrs: r.PubAddrs.Get(),
+	}.Marshal(r.buf))
+
+	if p.Direct {
+		return
+	}
+
+	// Send probes if not a direct connection. The server sends probes without
+	// trace IDs unless responding to a client probe.
+	for _, addr := range msg.Packet.PossibleAddrs {
+		if !addr.IsValid() {
+			break
+		}
+		r.logf("Probing %v...", addr)
+		r.sendControlToAddr(packetProbe{}.Marshal(r.buf), addr)
+	}
+}
+
+func (r *remoteFSM) stateServer_onProbe(msg controlMsg[packetProbe]) {
+	if !msg.SrcAddr.IsValid() {
+		return
+	}
+
+	data := packetProbe{TraceID: msg.Packet.TraceID}.Marshal(r.buf)
+	r.sendControlToAddr(data, msg.SrcAddr)
+}
+
+func (r *remoteFSM) stateServer_onPingTimer() {
+	conf := r.conf()
+	if time.Since(r.lastSeen) > timeoutInterval && conf.Up {
+		// Reset trace ID to ensure connection goes up on next SYN.
+		r.traceID = 0
+		conf.Up = false
+		r.updateConf(conf)
+		r.logf("Timeout.")
+	}
+}
+
+// ----------------------------------------------------------------------------
+
+func (r *remoteFSM) enterClientInit() stateFunc {
+	conf := r.conf()
+	ip, ipValid := netip.AddrFromSlice(conf.Peer.PublicIP)
+
+	conf.Up = false
+	conf.Server = false
+	conf.Direct = ipValid
+	conf.DirectAddr = netip.AddrPortFrom(ip, conf.Peer.Port)
+	conf.DataCipher = newDataCipher()
+
+	r.updateConf(conf)
+	r.logf("==> ClientInit")
+
+	r.lastSeen = time.Now()
+	r.pingTimer.Reset(pingInterval)
+	r.stateClientInit_sendInit()
+	return r.stateClientInit
+}
+
+func (r *remoteFSM) stateClientInit(iMsg any) stateFunc {
+	switch msg := iMsg.(type) {
+	case peerUpdateMsg:
+		return r.enterPeerUpdating(msg.Peer)
+	case controlMsg[packetInit]:
+		return r.stateClientInit_onInit(msg)
+	case controlMsg[packetSyn]:
+		r.logf("Unexpected SYN")
+	case controlMsg[packetAck]:
+		r.logf("Unexpected ACK")
+	case controlMsg[packetProbe]:
+		// Ignore
+	case controlMsg[packetLocalDiscovery]:
+		// Ignore
+	case pingTimerMsg:
+		return r.stateClientInit_onPing()
+	default:
+		r.logf("Unexpected message: %#v", iMsg)
+	}
+
+	return r.stateClientInit
+}
+
+func (r *remoteFSM) stateClientInit_sendInit() {
+	conf := r.conf()
+	r.traceID = r.NewTraceID()
+	init := packetInit{
+		TraceID: r.traceID,
+		Direct:  conf.Direct,
+		Version: version,
+	}
+	r.sendControl(conf, init.Marshal(r.buf))
+}
+
+func (r *remoteFSM) stateClientInit_onInit(msg controlMsg[packetInit]) stateFunc {
+	if msg.Packet.TraceID != r.traceID {
+		r.logf("Invalid trace ID on INIT.")
+		return r.stateClientInit
+	}
+	r.logf("Got INIT version %d.", msg.Packet.Version)
+	return r.enterClient()
+}
+
+func (r *remoteFSM) stateClientInit_onPing() stateFunc {
+	if time.Since(r.lastSeen) < timeoutInterval {
+		r.stateClientInit_sendInit()
+		return r.stateClientInit
+	}
+
+	// Direct connect failed. Try indirect.
+	conf := r.conf()
+
+	if conf.Direct {
+		conf.Direct = false
+		r.updateConf(conf)
+		r.lastSeen = time.Now()
+		r.stateClientInit_sendInit()
+		r.logf("Direct connection failed. Attempting indirect connection.")
+		return r.stateClientInit
+	}
+
+	// Indirect failed. Re-enter init state.
+	r.logf("Timeout.")
+	return r.enterClientInit()
+}
+
+// ----------------------------------------------------------------------------
+
+func (r *remoteFSM) enterClient() stateFunc {
+	conf := r.conf()
+	clear(r.probes)
+
+	r.traceID = r.NewTraceID()
+	r.stateClient_sendSyn(conf)
+
+	r.pingTimer.Reset(pingInterval)
+	r.logf("==> Client")
+	return r.stateClient
+}
+
+func (r *remoteFSM) stateClient(iMsg any) stateFunc {
+	switch msg := iMsg.(type) {
+	case peerUpdateMsg:
+		return r.enterPeerUpdating(msg.Peer)
+	case controlMsg[packetAck]:
+		r.stateClient_onAck(msg)
+	case controlMsg[packetProbe]:
+		r.stateClient_onProbe(msg)
+	case controlMsg[packetLocalDiscovery]:
+		r.stateClient_onLocalDiscovery(msg)
+	case pingTimerMsg:
+		return r.stateClient_onPingTimer()
+	default:
+		r.logf("Ignoring message: %v", iMsg)
+	}
+	return r.stateClient
+}
+
+func (r *remoteFSM) stateClient_onAck(msg controlMsg[packetAck]) {
+	if msg.Packet.TraceID != r.traceID {
+		return
+	}
+
+	r.lastSeen = time.Now()
+
+	conf := r.conf()
+	if !conf.Up {
+		conf.Up = true
+		r.updateConf(conf)
+		r.logf("Got ACK.")
+	}
+
+	if conf.Direct {
+		r.PubAddrs.Store(msg.Packet.ToAddr)
+		return
+	}
+
+	// Relayed.
+
+	r.stateClient_cleanProbes()
+
+	for _, addr := range msg.Packet.PossibleAddrs {
+		if !addr.IsValid() {
+			break
+		}
+		r.stateClient_sendProbeTo(addr)
+	}
+}
+
+func (r *remoteFSM) stateClient_cleanProbes() {
+	for key, sent := range r.probes {
+		if time.Since(sent.SentAt) > pingInterval {
+			delete(r.probes, key)
+		}
+	}
+}
+
+func (r *remoteFSM) stateClient_sendProbeTo(addr netip.AddrPort) {
+	probe := packetProbe{TraceID: r.NewTraceID()}
+	r.probes[probe.TraceID] = sentProbe{
+		SentAt: time.Now(),
+		Addr:   addr,
+	}
+	r.logf("Probing %v...", addr)
+	r.sendControlToAddr(probe.Marshal(r.buf), addr)
+}
+
+func (r *remoteFSM) stateClient_onProbe(msg controlMsg[packetProbe]) {
+	conf := r.conf()
+	if conf.Direct {
+		return
+	}
+
+	r.stateClient_cleanProbes()
+
+	sent, ok := r.probes[msg.Packet.TraceID]
+	if !ok {
+		return
+	}
+
+	conf.Direct = true
+	conf.DirectAddr = sent.Addr
+	r.updateConf(conf)
+
+	r.traceID = r.NewTraceID()
+	r.stateClient_sendSyn(conf)
+	r.logf("Successful probe to %v.", sent.Addr)
+}
+
+func (r *remoteFSM) stateClient_onLocalDiscovery(msg controlMsg[packetLocalDiscovery]) {
+	conf := r.conf()
+	if conf.Direct {
+		return
+	}
+
+	// The source port will be the multicast port, so we'll have to
+	// construct the correct address using the peer's listed port.
+	addr := netip.AddrPortFrom(msg.SrcAddr.Addr(), conf.Peer.Port)
+	r.stateClient_sendProbeTo(addr)
+}
+
+func (r *remoteFSM) stateClient_onPingTimer() stateFunc {
+	conf := r.conf()
+
+	if time.Since(r.lastSeen) > timeoutInterval {
+		if conf.Up {
+			r.logf("Timeout.")
+		}
+		return r.enterClientInit()
+	}
+
+	r.stateClient_sendSyn(conf)
+	return r.stateClient
+}
+
+func (r *remoteFSM) stateClient_sendSyn(conf remoteConfig) {
+	syn := packetSyn{
+		TraceID:       r.traceID,
+		SharedKey:     conf.DataCipher.Key(),
+		Direct:        conf.Direct,
+		PossibleAddrs: r.PubAddrs.Get(),
+	}
+
+	r.sendControl(conf, syn.Marshal(r.buf))
+}

peer/statusserver.go

@@ -0,0 +1,71 @@
+package peer
+
+import (
+	"encoding/json"
+	"log"
+	"net"
+	"net/http"
+	"net/netip"
+	"os"
+)
+
+type StatusReport struct {
+	LocalPeerIP byte
+	Network     []byte
+	RelayPeerIP byte
+	Remotes     []RemoteStatus
+}
+
+type RemoteStatus struct {
+	PeerIP     byte
+	Up         bool
+	Name       string
+	PublicIP   []byte
+	Port       uint16
+	Relay      bool
+	Server     bool
+	Direct     bool
+	DirectAddr netip.AddrPort
+}
+
+func runStatusServer(g Globals, socketPath string) {
+	_ = os.RemoveAll(socketPath)
+
+	handler := func(w http.ResponseWriter, r *http.Request) {
+		report := StatusReport{
+			LocalPeerIP: g.LocalPeerIP,
+			Network:     g.Network,
+			Remotes:     make([]RemoteStatus, 0, 255),
+		}
+
+		relay := g.RelayHandler.Load()
+		if relay != nil {
+			if relayStatus, ok := relay.Status(); ok {
+				report.RelayPeerIP = relayStatus.PeerIP
+			}
+		}
+
+		for i := range g.RemotePeers {
+			remote := g.RemotePeers[i].Load()
+			status, ok := remote.Status()
+			if !ok {
+				continue
+			}
+			report.Remotes = append(report.Remotes, status)
+		}
+
+		json.NewEncoder(w).Encode(report)
+	}
+
+	server := http.Server{
+		Handler: http.HandlerFunc(handler),
+	}
+
+	unixListener, err := net.Listen("unix", socketPath)
+	if err != nil {
+		log.Fatalf("Failed to bind to unix socket: %v", err)
+	}
+	if err := server.Serve(unixListener); err != nil {
+		log.Fatalf("Failed to serve on unix socket: %v", err)
+	}
+}