From 7ea4e9575e611192ec4b81b51dfc13e89e200e74 Mon Sep 17 00:00:00 2001
From: Neil Alexander <neilalexander@users.noreply.github.com>
Date: Thu, 28 Mar 2019 16:13:14 +0000
Subject: [PATCH] Break out multicast into a separate package

---
 cmd/yggdrasil/main.go                         | 11 +++-
 src/{yggdrasil => multicast}/multicast.go     | 63 +++++++++++--------
 .../multicast_darwin.go                       |  8 +--
 .../multicast_other.go                        |  6 +-
 .../multicast_unix.go                         |  6 +-
 .../multicast_windows.go                      |  6 +-
 src/yggdrasil/admin.go                        |  4 +-
 src/yggdrasil/core.go                         | 30 ++++++---
 src/yggdrasil/mobile.go                       |  4 +-
 src/yggdrasil/tcp.go                          | 36 +++++------
 10 files changed, 103 insertions(+), 71 deletions(-)
 rename src/{yggdrasil => multicast}/multicast.go (78%)
 rename src/{yggdrasil => multicast}/multicast_darwin.go (86%)
 rename src/{yggdrasil => multicast}/multicast_other.go (53%)
 rename src/{yggdrasil => multicast}/multicast_unix.go (75%)
 rename src/{yggdrasil => multicast}/multicast_windows.go (75%)

diff --git a/cmd/yggdrasil/main.go b/cmd/yggdrasil/main.go
index cec77056..fe848497 100644
--- a/cmd/yggdrasil/main.go
+++ b/cmd/yggdrasil/main.go
@@ -19,6 +19,7 @@ import (
 	"github.com/mitchellh/mapstructure"
 
 	"github.com/yggdrasil-network/yggdrasil-go/src/config"
+	"github.com/yggdrasil-network/yggdrasil-go/src/multicast"
 	"github.com/yggdrasil-network/yggdrasil-go/src/tuntap"
 	"github.com/yggdrasil-network/yggdrasil-go/src/yggdrasil"
 )
@@ -27,8 +28,9 @@ type nodeConfig = config.NodeConfig
 type Core = yggdrasil.Core
 
 type node struct {
-	core Core
-	tun  tuntap.TunAdapter
+	core      Core
+	tun       tuntap.TunAdapter
+	multicast multicast.Multicast
 }
 
 func readConfig(useconf *bool, useconffile *string, normaliseconf *bool) *nodeConfig {
@@ -254,6 +256,11 @@ func main() {
 		logger.Errorln("An error occurred during startup")
 		panic(err)
 	}
+	// Start the multicast interface
+	n.multicast.Init(&n.core, cfg, logger)
+	if err := n.multicast.Start(); err != nil {
+		logger.Errorln("An error occurred starting multicast:", err)
+	}
 	// The Stop function ensures that the TUN/TAP adapter is correctly shut down
 	// before the program exits.
 	defer func() {
diff --git a/src/yggdrasil/multicast.go b/src/multicast/multicast.go
similarity index 78%
rename from src/yggdrasil/multicast.go
rename to src/multicast/multicast.go
index ab1b158e..71bdbc83 100644
--- a/src/yggdrasil/multicast.go
+++ b/src/multicast/multicast.go
@@ -1,4 +1,4 @@
-package yggdrasil
+package multicast
 
 import (
 	"context"
@@ -7,23 +7,31 @@ import (
 	"regexp"
 	"time"
 
+	"github.com/gologme/log"
+
+	"github.com/yggdrasil-network/yggdrasil-go/src/config"
+	"github.com/yggdrasil-network/yggdrasil-go/src/yggdrasil"
 	"golang.org/x/net/ipv6"
 )
 
-type multicast struct {
-	core        *Core
+type Multicast struct {
+	core        *yggdrasil.Core
+	config      *config.NodeConfig
+	log         *log.Logger
 	reconfigure chan chan error
 	sock        *ipv6.PacketConn
 	groupAddr   string
-	listeners   map[string]*tcpListener
+	listeners   map[string]*yggdrasil.TcpListener
 	listenPort  uint16
 }
 
-func (m *multicast) init(core *Core) {
+func (m *Multicast) Init(core *yggdrasil.Core, config *config.NodeConfig, log *log.Logger) {
 	m.core = core
+	m.config = config
+	m.log = log
 	m.reconfigure = make(chan chan error, 1)
-	m.listeners = make(map[string]*tcpListener)
-	current, _ := m.core.config.Get()
+	m.listeners = make(map[string]*yggdrasil.TcpListener)
+	current := m.config //.Get()
 	m.listenPort = current.LinkLocalTCPPort
 	go func() {
 		for {
@@ -34,15 +42,15 @@ func (m *multicast) init(core *Core) {
 	m.groupAddr = "[ff02::114]:9001"
 	// Check if we've been given any expressions
 	if count := len(m.interfaces()); count != 0 {
-		m.core.log.Infoln("Found", count, "multicast interface(s)")
+		m.log.Infoln("Found", count, "multicast interface(s)")
 	}
 }
 
-func (m *multicast) start() error {
+func (m *Multicast) Start() error {
 	if len(m.interfaces()) == 0 {
-		m.core.log.Infoln("Multicast discovery is disabled")
+		m.log.Infoln("Multicast discovery is disabled")
 	} else {
-		m.core.log.Infoln("Multicast discovery is enabled")
+		m.log.Infoln("Multicast discovery is enabled")
 		addr, err := net.ResolveUDPAddr("udp", m.groupAddr)
 		if err != nil {
 			return err
@@ -67,9 +75,10 @@ func (m *multicast) start() error {
 	return nil
 }
 
-func (m *multicast) interfaces() map[string]net.Interface {
+func (m *Multicast) interfaces() map[string]net.Interface {
 	// Get interface expressions from config
-	current, _ := m.core.config.Get()
+	//current, _ := m.config.Get()
+	current := m.config
 	exprs := current.MulticastInterfaces
 	// Ask the system for network interfaces
 	interfaces := make(map[string]net.Interface)
@@ -106,7 +115,7 @@ func (m *multicast) interfaces() map[string]net.Interface {
 	return interfaces
 }
 
-func (m *multicast) announce() {
+func (m *Multicast) announce() {
 	groupAddr, err := net.ResolveUDPAddr("udp6", m.groupAddr)
 	if err != nil {
 		panic(err)
@@ -122,9 +131,9 @@ func (m *multicast) announce() {
 		for name, listener := range m.listeners {
 			// Prepare our stop function!
 			stop := func() {
-				listener.stop <- true
+				listener.Stop <- true
 				delete(m.listeners, name)
-				m.core.log.Debugln("No longer multicasting on", name)
+				m.log.Debugln("No longer multicasting on", name)
 			}
 			// If the interface is no longer visible on the system then stop the
 			// listener, as another one will be started further down
@@ -135,7 +144,7 @@ func (m *multicast) announce() {
 			// It's possible that the link-local listener address has changed so if
 			// that is the case then we should clean up the interface listener
 			found := false
-			listenaddr, err := net.ResolveTCPAddr("tcp6", listener.listener.Addr().String())
+			listenaddr, err := net.ResolveTCPAddr("tcp6", listener.Listener.Addr().String())
 			if err != nil {
 				stop()
 				continue
@@ -184,17 +193,18 @@ func (m *multicast) announce() {
 				// Join the multicast group
 				m.sock.JoinGroup(&iface, groupAddr)
 				// Try and see if we already have a TCP listener for this interface
-				var listener *tcpListener
-				if l, ok := m.listeners[iface.Name]; !ok || l.listener == nil {
+				var listener *yggdrasil.TcpListener
+				if l, ok := m.listeners[iface.Name]; !ok || l.Listener == nil {
 					// No listener was found - let's create one
 					listenaddr := fmt.Sprintf("[%s%%%s]:%d", addrIP, iface.Name, m.listenPort)
-					if li, err := m.core.link.tcp.listen(listenaddr); err == nil {
-						m.core.log.Debugln("Started multicasting on", iface.Name)
+					//if li, err := m.core.link.tcp.listen(listenaddr); err == nil {
+					if li, err := m.core.ListenTCP(listenaddr); err == nil {
+						m.log.Debugln("Started multicasting on", iface.Name)
 						// Store the listener so that we can stop it later if needed
 						m.listeners[iface.Name] = li
 						listener = li
 					} else {
-						m.core.log.Warnln("Not multicasting on", iface.Name, "due to error:", err)
+						m.log.Warnln("Not multicasting on", iface.Name, "due to error:", err)
 					}
 				} else {
 					// An existing listener was found
@@ -205,7 +215,7 @@ func (m *multicast) announce() {
 					continue
 				}
 				// Get the listener details and construct the multicast beacon
-				lladdr := listener.listener.Addr().String()
+				lladdr := listener.Listener.Addr().String()
 				if a, err := net.ResolveTCPAddr("tcp6", lladdr); err == nil {
 					a.Zone = ""
 					destAddr.Zone = iface.Name
@@ -219,7 +229,7 @@ func (m *multicast) announce() {
 	}
 }
 
-func (m *multicast) listen() {
+func (m *Multicast) listen() {
 	groupAddr, err := net.ResolveUDPAddr("udp6", m.groupAddr)
 	if err != nil {
 		panic(err)
@@ -251,8 +261,9 @@ func (m *multicast) listen() {
 			continue
 		}
 		addr.Zone = ""
-		if err := m.core.link.call("tcp://"+addr.String(), from.Zone); err != nil {
-			m.core.log.Debugln("Call from multicast failed:", err)
+		//if err := m.core.link.call("tcp://"+addr.String(), from.Zone); err != nil {
+		if err := m.core.CallPeer("tcp://"+addr.String(), from.Zone); err != nil {
+			m.log.Debugln("Call from multicast failed:", err)
 		}
 	}
 }
diff --git a/src/yggdrasil/multicast_darwin.go b/src/multicast/multicast_darwin.go
similarity index 86%
rename from src/yggdrasil/multicast_darwin.go
rename to src/multicast/multicast_darwin.go
index 53646113..900354c7 100644
--- a/src/yggdrasil/multicast_darwin.go
+++ b/src/multicast/multicast_darwin.go
@@ -1,6 +1,6 @@
 // +build darwin
 
-package yggdrasil
+package multicast
 
 /*
 #cgo CFLAGS: -x objective-c
@@ -31,11 +31,11 @@ import (
 
 var awdlGoroutineStarted bool
 
-func (m *multicast) multicastStarted() {
+func (m *Multicast) multicastStarted() {
 	if awdlGoroutineStarted {
 		return
 	}
-	m.core.log.Infoln("Multicast discovery will wake up AWDL if required")
+	m.log.Infoln("Multicast discovery will wake up AWDL if required")
 	awdlGoroutineStarted = true
 	for {
 		C.StopAWDLBrowsing()
@@ -49,7 +49,7 @@ func (m *multicast) multicastStarted() {
 	}
 }
 
-func (m *multicast) multicastReuse(network string, address string, c syscall.RawConn) error {
+func (m *Multicast) multicastReuse(network string, address string, c syscall.RawConn) error {
 	var control error
 	var reuseport error
 	var recvanyif error
diff --git a/src/yggdrasil/multicast_other.go b/src/multicast/multicast_other.go
similarity index 53%
rename from src/yggdrasil/multicast_other.go
rename to src/multicast/multicast_other.go
index e20bbda3..16ea15d6 100644
--- a/src/yggdrasil/multicast_other.go
+++ b/src/multicast/multicast_other.go
@@ -1,13 +1,13 @@
 // +build !linux,!darwin,!netbsd,!freebsd,!openbsd,!dragonflybsd,!windows
 
-package yggdrasil
+package multicast
 
 import "syscall"
 
-func (m *multicast) multicastStarted() {
+func (m *Multicast) multicastStarted() {
 
 }
 
-func (m *multicast) multicastReuse(network string, address string, c syscall.RawConn) error {
+func (m *Multicast) multicastReuse(network string, address string, c syscall.RawConn) error {
 	return nil
 }
diff --git a/src/yggdrasil/multicast_unix.go b/src/multicast/multicast_unix.go
similarity index 75%
rename from src/yggdrasil/multicast_unix.go
rename to src/multicast/multicast_unix.go
index 3da1ab4e..9d6a01a8 100644
--- a/src/yggdrasil/multicast_unix.go
+++ b/src/multicast/multicast_unix.go
@@ -1,15 +1,15 @@
 // +build linux netbsd freebsd openbsd dragonflybsd
 
-package yggdrasil
+package multicast
 
 import "syscall"
 import "golang.org/x/sys/unix"
 
-func (m *multicast) multicastStarted() {
+func (m *Multicast) multicastStarted() {
 
 }
 
-func (m *multicast) multicastReuse(network string, address string, c syscall.RawConn) error {
+func (m *Multicast) multicastReuse(network string, address string, c syscall.RawConn) error {
 	var control error
 	var reuseport error
 
diff --git a/src/yggdrasil/multicast_windows.go b/src/multicast/multicast_windows.go
similarity index 75%
rename from src/yggdrasil/multicast_windows.go
rename to src/multicast/multicast_windows.go
index 3e07f6cc..7a846b1e 100644
--- a/src/yggdrasil/multicast_windows.go
+++ b/src/multicast/multicast_windows.go
@@ -1,15 +1,15 @@
 // +build windows
 
-package yggdrasil
+package multicast
 
 import "syscall"
 import "golang.org/x/sys/windows"
 
-func (m *multicast) multicastStarted() {
+func (m *Multicast) multicastStarted() {
 
 }
 
-func (m *multicast) multicastReuse(network string, address string, c syscall.RawConn) error {
+func (m *Multicast) multicastReuse(network string, address string, c syscall.RawConn) error {
 	var control error
 	var reuseaddr error
 
diff --git a/src/yggdrasil/admin.go b/src/yggdrasil/admin.go
index 002f974c..2db7ad4c 100644
--- a/src/yggdrasil/admin.go
+++ b/src/yggdrasil/admin.go
@@ -209,13 +209,13 @@ func (a *admin) init(c *Core) {
 				}, nil
 			}
 		})*/
-	a.addHandler("getMulticastInterfaces", []string{}, func(in admin_info) (admin_info, error) {
+	/*a.addHandler("getMulticastInterfaces", []string{}, func(in admin_info) (admin_info, error) {
 		var intfs []string
 		for _, v := range a.core.multicast.interfaces() {
 			intfs = append(intfs, v.Name)
 		}
 		return admin_info{"multicast_interfaces": intfs}, nil
-	})
+	})*/
 	a.addHandler("getAllowedEncryptionPublicKeys", []string{}, func(in admin_info) (admin_info, error) {
 		return admin_info{"allowed_box_pubs": a.getAllowedEncryptionPublicKeys()}, nil
 	})
diff --git a/src/yggdrasil/core.go b/src/yggdrasil/core.go
index a583d582..461e8e93 100644
--- a/src/yggdrasil/core.go
+++ b/src/yggdrasil/core.go
@@ -40,9 +40,9 @@ type Core struct {
 	dht         dht
 	admin       admin
 	searches    searches
-	multicast   multicast
-	link        link
-	log         *log.Logger
+	//multicast   multicast
+	link link
+	log  *log.Logger
 }
 
 func (c *Core) init() error {
@@ -82,7 +82,7 @@ func (c *Core) init() error {
 	c.searches.init(c)
 	c.dht.init(c)
 	c.sessions.init(c)
-	c.multicast.init(c)
+	//c.multicast.init(c)
 	c.peers.init(c)
 	c.router.init(c)
 	c.switchTable.init(c) // TODO move before peers? before router?
@@ -137,7 +137,7 @@ func (c *Core) UpdateConfig(config *config.NodeConfig) {
 		c.router.cryptokey.reconfigure,
 		c.switchTable.reconfigure,
 		c.link.reconfigure,
-		c.multicast.reconfigure,
+		//c.multicast.reconfigure,
 	}
 
 	for _, component := range components {
@@ -228,10 +228,10 @@ func (c *Core) Start(nc *config.NodeConfig, log *log.Logger) error {
 		return err
 	}
 
-	if err := c.multicast.start(); err != nil {
+	/*if err := c.multicast.start(); err != nil {
 		c.log.Errorln("Failed to start multicast interface")
 		return err
-	}
+	}*/
 
 	if err := c.router.tun.Start(c.router.addr, c.router.subnet); err != nil {
 		c.log.Errorln("Failed to start TUN/TAP")
@@ -251,6 +251,11 @@ func (c *Core) Stop() {
 	c.admin.close()
 }
 
+// ListenOn starts a new listener
+func (c *Core) ListenTCP(uri string) (*TcpListener, error) {
+	return c.link.tcp.listen(uri)
+}
+
 // Generates a new encryption keypair. The encryption keys are used to
 // encrypt traffic and to derive the IPv6 address/subnet of the node.
 func (c *Core) NewEncryptionKeys() (*crypto.BoxPubKey, *crypto.BoxPrivKey) {
@@ -303,11 +308,20 @@ func (c *Core) SetLogger(log *log.Logger) {
 }
 
 // Adds a peer. This should be specified in the peer URI format, i.e.
-// tcp://a.b.c.d:e, udp://a.b.c.d:e, socks://a.b.c.d:e/f.g.h.i:j
+// tcp://a.b.c.d:e, udp://a.b.c.d:e, socks://a.b.c.d:e/f.g.h.i:j. This adds the
+// peer to the peer list, so that they will be called again if the connection
+// drops.
 func (c *Core) AddPeer(addr string, sintf string) error {
 	return c.admin.addPeer(addr, sintf)
 }
 
+// Calls a peer. This should be specified in the peer URI format, i.e.
+// tcp://a.b.c.d:e, udp://a.b.c.d:e, socks://a.b.c.d:e/f.g.h.i:j. This calls the
+// peer once, and if the connection drops, it won't be called again.
+func (c *Core) CallPeer(addr string, sintf string) error {
+	return c.link.call(addr, sintf)
+}
+
 // Adds an allowed public key. This allow peerings to be restricted only to
 // keys that you have selected.
 func (c *Core) AddAllowedEncryptionPublicKey(boxStr string) error {
diff --git a/src/yggdrasil/mobile.go b/src/yggdrasil/mobile.go
index 81aa47f1..bad1424a 100644
--- a/src/yggdrasil/mobile.go
+++ b/src/yggdrasil/mobile.go
@@ -115,7 +115,7 @@ func (c *Core) GetSigPubKeyString() string {
 // dummy adapter in place of real TUN - when this call returns a packet, you
 // will probably want to give it to the OS to write to TUN.
 func (c *Core) RouterRecvPacket() ([]byte, error) {
-	packet := <-c.router.tun.recv
+	packet := <-c.router.tun.Recv
 	return packet, nil
 }
 
@@ -125,6 +125,6 @@ func (c *Core) RouterRecvPacket() ([]byte, error) {
 // Yggdrasil.
 func (c *Core) RouterSendPacket(buf []byte) error {
 	packet := append(util.GetBytes(), buf[:]...)
-	c.router.tun.send <- packet
+	c.router.tun.Send <- packet
 	return nil
 }
diff --git a/src/yggdrasil/tcp.go b/src/yggdrasil/tcp.go
index f25ac412..b9681fc2 100644
--- a/src/yggdrasil/tcp.go
+++ b/src/yggdrasil/tcp.go
@@ -36,14 +36,14 @@ type tcp struct {
 	link        *link
 	reconfigure chan chan error
 	mutex       sync.Mutex // Protecting the below
-	listeners   map[string]*tcpListener
+	listeners   map[string]*TcpListener
 	calls       map[string]struct{}
 	conns       map[linkInfo](chan struct{})
 }
 
-type tcpListener struct {
-	listener net.Listener
-	stop     chan bool
+type TcpListener struct {
+	Listener net.Listener
+	Stop     chan bool
 }
 
 // Wrapper function to set additional options for specific connection types.
@@ -64,7 +64,7 @@ func (t *tcp) getAddr() *net.TCPAddr {
 	t.mutex.Lock()
 	defer t.mutex.Unlock()
 	for _, l := range t.listeners {
-		return l.listener.Addr().(*net.TCPAddr)
+		return l.Listener.Addr().(*net.TCPAddr)
 	}
 	return nil
 }
@@ -76,7 +76,7 @@ func (t *tcp) init(l *link) error {
 	t.mutex.Lock()
 	t.calls = make(map[string]struct{})
 	t.conns = make(map[linkInfo](chan struct{}))
-	t.listeners = make(map[string]*tcpListener)
+	t.listeners = make(map[string]*TcpListener)
 	t.mutex.Unlock()
 
 	go func() {
@@ -103,7 +103,7 @@ func (t *tcp) init(l *link) error {
 					t.mutex.Lock()
 					if listener, ok := t.listeners[d[6:]]; ok {
 						t.mutex.Unlock()
-						listener.stop <- true
+						listener.Stop <- true
 					} else {
 						t.mutex.Unlock()
 					}
@@ -129,7 +129,7 @@ func (t *tcp) init(l *link) error {
 	return nil
 }
 
-func (t *tcp) listen(listenaddr string) (*tcpListener, error) {
+func (t *tcp) listen(listenaddr string) (*TcpListener, error) {
 	var err error
 
 	ctx := context.Background()
@@ -138,9 +138,9 @@ func (t *tcp) listen(listenaddr string) (*tcpListener, error) {
 	}
 	listener, err := lc.Listen(ctx, "tcp", listenaddr)
 	if err == nil {
-		l := tcpListener{
-			listener: listener,
-			stop:     make(chan bool),
+		l := TcpListener{
+			Listener: listener,
+			Stop:     make(chan bool),
 		}
 		go t.listener(&l, listenaddr)
 		return &l, nil
@@ -150,7 +150,7 @@ func (t *tcp) listen(listenaddr string) (*tcpListener, error) {
 }
 
 // Runs the listener, which spawns off goroutines for incoming connections.
-func (t *tcp) listener(l *tcpListener, listenaddr string) {
+func (t *tcp) listener(l *TcpListener, listenaddr string) {
 	if l == nil {
 		return
 	}
@@ -158,7 +158,7 @@ func (t *tcp) listener(l *tcpListener, listenaddr string) {
 	t.mutex.Lock()
 	if _, isIn := t.listeners[listenaddr]; isIn {
 		t.mutex.Unlock()
-		l.listener.Close()
+		l.Listener.Close()
 		return
 	} else {
 		t.listeners[listenaddr] = l
@@ -167,20 +167,20 @@ func (t *tcp) listener(l *tcpListener, listenaddr string) {
 	// And here we go!
 	accepted := make(chan bool)
 	defer func() {
-		t.link.core.log.Infoln("Stopping TCP listener on:", l.listener.Addr().String())
-		l.listener.Close()
+		t.link.core.log.Infoln("Stopping TCP listener on:", l.Listener.Addr().String())
+		l.Listener.Close()
 		t.mutex.Lock()
 		delete(t.listeners, listenaddr)
 		t.mutex.Unlock()
 	}()
-	t.link.core.log.Infoln("Listening for TCP on:", l.listener.Addr().String())
+	t.link.core.log.Infoln("Listening for TCP on:", l.Listener.Addr().String())
 	for {
 		var sock net.Conn
 		var err error
 		// Listen in a separate goroutine, as that way it does not block us from
 		// receiving "stop" events
 		go func() {
-			sock, err = l.listener.Accept()
+			sock, err = l.Listener.Accept()
 			accepted <- true
 		}()
 		// Wait for either an accepted connection, or a message telling us to stop
@@ -192,7 +192,7 @@ func (t *tcp) listener(l *tcpListener, listenaddr string) {
 				return
 			}
 			go t.handler(sock, true, nil)
-		case <-l.stop:
+		case <-l.Stop:
 			return
 		}
 	}