net -> p2p/net

The net package is the next to move. It will be massaged
a bit still to fix the Network / "NetworkBackend" conflict.

net/mock/interface.go

+// Package mocknet provides a mock net.Network to test with.
+//
+// - a Mocknet has many inet.Networks
+// - a Mocknet has many Links
+// - a Link joins two inet.Networks
+// - inet.Conns and inet.Streams are created by inet.Networks
+package mocknet
+
+import (
+	"io"
+	"time"
+
+	ic "github.com/jbenet/go-ipfs/p2p/crypto"
+	inet "github.com/jbenet/go-ipfs/p2p/net"
+	peer "github.com/jbenet/go-ipfs/p2p/peer"
+
+	ma "github.com/jbenet/go-ipfs/Godeps/_workspace/src/github.com/jbenet/go-multiaddr"
+)
+
+type Mocknet interface {
+
+	// GenPeer generates a peer and its inet.Network in the Mocknet
+	GenPeer() (inet.Network, error)
+
+	// AddPeer adds an existing peer. we need both a privkey and addr.
+	// ID is derived from PrivKey
+	AddPeer(ic.PrivKey, ma.Multiaddr) (inet.Network, error)
+
+	// retrieve things (with randomized iteration order)
+	Peers() []peer.ID
+	Net(peer.ID) inet.Network
+	Nets() []inet.Network
+	Links() LinkMap
+	LinksBetweenPeers(a, b peer.ID) []Link
+	LinksBetweenNets(a, b inet.Network) []Link
+
+	// Links are the **ability to connect**.
+	// think of Links as the physical medium.
+	// For p1 and p2 to connect, a link must exist between them.
+	// (this makes it possible to test dial failures, and
+	// things like relaying traffic)
+	LinkPeers(peer.ID, peer.ID) (Link, error)
+	LinkNets(inet.Network, inet.Network) (Link, error)
+	Unlink(Link) error
+	UnlinkPeers(peer.ID, peer.ID) error
+	UnlinkNets(inet.Network, inet.Network) error
+
+	// LinkDefaults are the default options that govern links
+	// if they do not have thier own option set.
+	SetLinkDefaults(LinkOptions)
+	LinkDefaults() LinkOptions
+
+	// Connections are the usual. Connecting means Dialing.
+	// **to succeed, peers must be linked beforehand**
+	ConnectPeers(peer.ID, peer.ID) error
+	ConnectNets(inet.Network, inet.Network) error
+	DisconnectPeers(peer.ID, peer.ID) error
+	DisconnectNets(inet.Network, inet.Network) error
+}
+
+// LinkOptions are used to change aspects of the links.
+// Sorry but they dont work yet :(
+type LinkOptions struct {
+	Latency   time.Duration
+	Bandwidth int // in bytes-per-second
+	// we can make these values distributions down the road.
+}
+
+// Link represents the **possibility** of a connection between
+// two peers. Think of it like physical network links. Without
+// them, the peers can try and try but they won't be able to
+// connect. This allows constructing topologies where specific
+// nodes cannot talk to each other directly. :)
+type Link interface {
+	Networks() []inet.Network
+	Peers() []peer.ID
+
+	SetOptions(LinkOptions)
+	Options() LinkOptions
+
+	// Metrics() Metrics
+}
+
+// LinkMap is a 3D map to give us an easy way to track links.
+// (wow, much map. so data structure. how compose. ahhh pointer)
+type LinkMap map[string]map[string]map[Link]struct{}
+
+// Printer lets you inspect things :)
+type Printer interface {
+	// MocknetLinks shows the entire Mocknet's link table :)
+	MocknetLinks(mn Mocknet)
+	NetworkConns(ni inet.Network)
+}
+
+// PrinterTo returns a Printer ready to write to w.
+func PrinterTo(w io.Writer) Printer {
+	return &printer{w}
+}

net/mock/mock.go

+package mocknet
+
+import (
+	eventlog "github.com/jbenet/go-ipfs/util/eventlog"
+
+	context "github.com/jbenet/go-ipfs/Godeps/_workspace/src/code.google.com/p/go.net/context"
+)
+
+var log = eventlog.Logger("mocknet")
+
+// WithNPeers constructs a Mocknet with N peers.
+func WithNPeers(ctx context.Context, n int) (Mocknet, error) {
+	m := New(ctx)
+	for i := 0; i < n; i++ {
+		if _, err := m.GenPeer(); err != nil {
+			return nil, err
+		}
+	}
+	return m, nil
+}
+
+// FullMeshLinked constructs a Mocknet with full mesh of Links.
+// This means that all the peers **can** connect to each other
+// (not that they already are connected. you can use m.ConnectAll())
+func FullMeshLinked(ctx context.Context, n int) (Mocknet, error) {
+	m, err := WithNPeers(ctx, n)
+	if err != nil {
+		return nil, err
+	}
+
+	nets := m.Nets()
+	for _, n1 := range nets {
+		for _, n2 := range nets {
+			// yes, even self.
+			if _, err := m.LinkNets(n1, n2); err != nil {
+				return nil, err
+			}
+		}
+	}
+
+	return m, nil
+}
+
+// FullMeshConnected constructs a Mocknet with full mesh of Connections.
+// This means that all the peers have dialed and are ready to talk to
+// each other.
+func FullMeshConnected(ctx context.Context, n int) (Mocknet, error) {
+	m, err := FullMeshLinked(ctx, n)
+	if err != nil {
+		return nil, err
+	}
+
+	nets := m.Nets()
+	for _, n1 := range nets {
+		for _, n2 := range nets {
+			if err := m.ConnectNets(n1, n2); err != nil {
+				return nil, err
+			}
+		}
+	}
+
+	return m, nil
+}

net/mock/mock_conn.go

+package mocknet
+
+import (
+	"container/list"
+	"sync"
+
+	ic "github.com/jbenet/go-ipfs/p2p/crypto"
+	inet "github.com/jbenet/go-ipfs/p2p/net"
+	mux "github.com/jbenet/go-ipfs/p2p/net/services/mux"
+	peer "github.com/jbenet/go-ipfs/p2p/peer"
+
+	ma "github.com/jbenet/go-ipfs/Godeps/_workspace/src/github.com/jbenet/go-multiaddr"
+)
+
+// conn represents one side's perspective of a
+// live connection between two peers.
+// it goes over a particular link.
+type conn struct {
+	local  peer.ID
+	remote peer.ID
+
+	localAddr  ma.Multiaddr
+	remoteAddr ma.Multiaddr
+
+	localPrivKey ic.PrivKey
+	remotePubKey ic.PubKey
+
+	net     *peernet
+	link    *link
+	rconn   *conn // counterpart
+	streams list.List
+
+	sync.RWMutex
+}
+
+func (c *conn) Close() error {
+	for _, s := range c.allStreams() {
+		s.Close()
+	}
+	c.net.removeConn(c)
+	return nil
+}
+
+func (c *conn) addStream(s *stream) {
+	c.Lock()
+	s.conn = c
+	c.streams.PushBack(s)
+	c.Unlock()
+}
+
+func (c *conn) removeStream(s *stream) {
+	c.Lock()
+	defer c.Unlock()
+	for e := c.streams.Front(); e != nil; e = e.Next() {
+		if s == e.Value {
+			c.streams.Remove(e)
+			return
+		}
+	}
+}
+
+func (c *conn) allStreams() []inet.Stream {
+	c.RLock()
+	defer c.RUnlock()
+
+	strs := make([]inet.Stream, 0, c.streams.Len())
+	for e := c.streams.Front(); e != nil; e = e.Next() {
+		s := e.Value.(*stream)
+		strs = append(strs, s)
+	}
+	return strs
+}
+
+func (c *conn) remoteOpenedStream(s *stream) {
+	c.addStream(s)
+	c.net.handleNewStream(s)
+}
+
+func (c *conn) openStream() *stream {
+	sl, sr := c.link.newStreamPair()
+	c.addStream(sl)
+	c.rconn.remoteOpenedStream(sr)
+	return sl
+}
+
+func (c *conn) NewStreamWithProtocol(pr inet.ProtocolID) (inet.Stream, error) {
+	log.Debugf("Conn.NewStreamWithProtocol: %s --> %s", c.local, c.remote)
+
+	s := c.openStream()
+	if err := mux.WriteProtocolHeader(pr, s); err != nil {
+		s.Close()
+		return nil, err
+	}
+	return s, nil
+}
+
+// LocalMultiaddr is the Multiaddr on this side
+func (c *conn) LocalMultiaddr() ma.Multiaddr {
+	return c.localAddr
+}
+
+// LocalPeer is the Peer on our side of the connection
+func (c *conn) LocalPeer() peer.ID {
+	return c.local
+}
+
+// LocalPrivateKey is the private key of the peer on our side.
+func (c *conn) LocalPrivateKey() ic.PrivKey {
+	return c.localPrivKey
+}
+
+// RemoteMultiaddr is the Multiaddr on the remote side
+func (c *conn) RemoteMultiaddr() ma.Multiaddr {
+	return c.remoteAddr
+}
+
+// RemotePeer is the Peer on the remote side
+func (c *conn) RemotePeer() peer.ID {
+	return c.remote
+}
+
+// RemotePublicKey is the private key of the peer on our side.
+func (c *conn) RemotePublicKey() ic.PubKey {
+	return c.remotePubKey
+}

net/mock/mock_link.go

+package mocknet
+
+import (
+	"io"
+	"sync"
+
+	inet "github.com/jbenet/go-ipfs/p2p/net"
+	peer "github.com/jbenet/go-ipfs/p2p/peer"
+)
+
+// link implements mocknet.Link
+// and, for simplicity, inet.Conn
+type link struct {
+	mock *mocknet
+	nets []*peernet
+	opts LinkOptions
+
+	// this could have addresses on both sides.
+
+	sync.RWMutex
+}
+
+func newLink(mn *mocknet, opts LinkOptions) *link {
+	return &link{mock: mn, opts: opts}
+}
+
+func (l *link) newConnPair(dialer *peernet) (*conn, *conn) {
+	l.RLock()
+	defer l.RUnlock()
+
+	mkconn := func(ln, rn *peernet) *conn {
+		c := &conn{net: ln, link: l}
+		c.local = ln.peer
+		c.remote = rn.peer
+
+		c.localAddr = ln.ps.Addresses(ln.peer)[0]
+		c.remoteAddr = rn.ps.Addresses(rn.peer)[0]
+
+		c.localPrivKey = ln.ps.PrivKey(ln.peer)
+		c.remotePubKey = rn.ps.PubKey(rn.peer)
+
+		return c
+	}
+
+	c1 := mkconn(l.nets[0], l.nets[1])
+	c2 := mkconn(l.nets[1], l.nets[0])
+	c1.rconn = c2
+	c2.rconn = c1
+
+	if dialer == c1.net {
+		return c1, c2
+	}
+	return c2, c1
+}
+
+func (l *link) newStreamPair() (*stream, *stream) {
+	r1, w1 := io.Pipe()
+	r2, w2 := io.Pipe()
+
+	s1 := &stream{Reader: r1, Writer: w2}
+	s2 := &stream{Reader: r2, Writer: w1}
+	return s1, s2
+}
+
+func (l *link) Networks() []inet.Network {
+	l.RLock()
+	defer l.RUnlock()
+
+	cp := make([]inet.Network, len(l.nets))
+	for i, n := range l.nets {
+		cp[i] = n
+	}
+	return cp
+}
+
+func (l *link) Peers() []peer.ID {
+	l.RLock()
+	defer l.RUnlock()
+
+	cp := make([]peer.ID, len(l.nets))
+	for i, n := range l.nets {
+		cp[i] = n.peer
+	}
+	return cp
+}
+
+func (l *link) SetOptions(o LinkOptions) {
+	l.opts = o
+}
+
+func (l *link) Options() LinkOptions {
+	return l.opts
+}

net/mock/mock_net.go

+package mocknet
+
+import (
+	"fmt"
+	"sync"
+
+	ic "github.com/jbenet/go-ipfs/p2p/crypto"
+	inet "github.com/jbenet/go-ipfs/p2p/net"
+	peer "github.com/jbenet/go-ipfs/p2p/peer"
+	testutil "github.com/jbenet/go-ipfs/util/testutil"
+
+	context "github.com/jbenet/go-ipfs/Godeps/_workspace/src/code.google.com/p/go.net/context"
+	ctxgroup "github.com/jbenet/go-ipfs/Godeps/_workspace/src/github.com/jbenet/go-ctxgroup"
+	ma "github.com/jbenet/go-ipfs/Godeps/_workspace/src/github.com/jbenet/go-multiaddr"
+)
+
+// mocknet implements mocknet.Mocknet
+type mocknet struct {
+	// must map on peer.ID (instead of peer.ID) because
+	// each inet.Network has different peerstore
+	nets map[peer.ID]*peernet
+
+	// links make it possible to connect two peers.
+	// think of links as the physical medium.
+	// usually only one, but there could be multiple
+	// **links are shared between peers**
+	links map[peer.ID]map[peer.ID]map[*link]struct{}
+
+	linkDefaults LinkOptions
+
+	cg ctxgroup.ContextGroup // for Context closing
+	sync.RWMutex
+}
+
+func New(ctx context.Context) Mocknet {
+	return &mocknet{
+		nets:  map[peer.ID]*peernet{},
+		links: map[peer.ID]map[peer.ID]map[*link]struct{}{},
+		cg:    ctxgroup.WithContext(ctx),
+	}
+}
+
+func (mn *mocknet) GenPeer() (inet.Network, error) {
+	sk, _, err := testutil.SeededKeyPair(int64(len(mn.nets)))
+	if err != nil {
+		return nil, err
+	}
+
+	a := testutil.RandLocalTCPAddress()
+
+	n, err := mn.AddPeer(sk, a)
+	if err != nil {
+		return nil, err
+	}
+
+	return n, nil
+}
+
+func (mn *mocknet) AddPeer(k ic.PrivKey, a ma.Multiaddr) (inet.Network, error) {
+	n, err := newPeernet(mn.cg.Context(), mn, k, a)
+	if err != nil {
+		return nil, err
+	}
+
+	// make sure to add listening address!
+	// this makes debugging things simpler as remembering to register
+	// an address may cause unexpected failure.
+	n.Peerstore().AddAddress(n.LocalPeer(), a)
+	log.Debugf("mocknet added listen addr for peer: %s -- %s", n.LocalPeer(), a)
+
+	mn.cg.AddChildGroup(n.cg)
+
+	mn.Lock()
+	mn.nets[n.peer] = n
+	mn.Unlock()
+	return n, nil
+}
+
+func (mn *mocknet) Peers() []peer.ID {
+	mn.RLock()
+	defer mn.RUnlock()
+
+	cp := make([]peer.ID, 0, len(mn.nets))
+	for _, n := range mn.nets {
+		cp = append(cp, n.peer)
+	}
+	return cp
+}
+
+func (mn *mocknet) Net(pid peer.ID) inet.Network {
+	mn.RLock()
+	defer mn.RUnlock()
+
+	for _, n := range mn.nets {
+		if n.peer == pid {
+			return n
+		}
+	}
+	return nil
+}
+
+func (mn *mocknet) Nets() []inet.Network {
+	mn.RLock()
+	defer mn.RUnlock()
+
+	cp := make([]inet.Network, 0, len(mn.nets))
+	for _, n := range mn.nets {
+		cp = append(cp, n)
+	}
+	return cp
+}
+
+// Links returns a copy of the internal link state map.
+// (wow, much map. so data structure. how compose. ahhh pointer)
+func (mn *mocknet) Links() LinkMap {
+	mn.RLock()
+	defer mn.RUnlock()
+
+	links := map[string]map[string]map[Link]struct{}{}
+	for p1, lm := range mn.links {
+		sp1 := string(p1)
+		links[sp1] = map[string]map[Link]struct{}{}
+		for p2, ls := range lm {
+			sp2 := string(p2)
+			links[sp1][sp2] = map[Link]struct{}{}
+			for l := range ls {
+				links[sp1][sp2][l] = struct{}{}
+			}
+		}
+	}
+	return links
+}
+
+func (mn *mocknet) LinkAll() error {
+	nets := mn.Nets()
+	for _, n1 := range nets {
+		for _, n2 := range nets {
+			if _, err := mn.LinkNets(n1, n2); err != nil {
+				return err
+			}
+		}
+	}
+	return nil
+}
+
+func (mn *mocknet) LinkPeers(p1, p2 peer.ID) (Link, error) {
+	mn.RLock()
+	n1 := mn.nets[p1]
+	n2 := mn.nets[p2]
+	mn.RUnlock()
+
+	if n1 == nil {
+		return nil, fmt.Errorf("network for p1 not in mocknet")
+	}
+
+	if n2 == nil {
+		return nil, fmt.Errorf("network for p2 not in mocknet")
+	}
+
+	return mn.LinkNets(n1, n2)
+}
+
+func (mn *mocknet) validate(n inet.Network) (*peernet, error) {
+	// WARNING: assumes locks acquired
+
+	nr, ok := n.(*peernet)
+	if !ok {
+		return nil, fmt.Errorf("Network not supported (use mock package nets only)")
+	}
+
+	if _, found := mn.nets[nr.peer]; !found {
+		return nil, fmt.Errorf("Network not on mocknet. is it from another mocknet?")
+	}
+
+	return nr, nil
+}
+
+func (mn *mocknet) LinkNets(n1, n2 inet.Network) (Link, error) {
+	mn.RLock()
+	n1r, err1 := mn.validate(n1)
+	n2r, err2 := mn.validate(n2)
+	ld := mn.linkDefaults
+	mn.RUnlock()
+
+	if err1 != nil {
+		return nil, err1
+	}
+	if err2 != nil {
+		return nil, err2
+	}
+
+	l := newLink(mn, ld)
+	l.nets = append(l.nets, n1r, n2r)
+	mn.addLink(l)
+	return l, nil
+}
+
+func (mn *mocknet) Unlink(l2 Link) error {
+
+	l, ok := l2.(*link)
+	if !ok {
+		return fmt.Errorf("only links from mocknet are supported")
+	}
+
+	mn.removeLink(l)
+	return nil
+}
+
+func (mn *mocknet) UnlinkPeers(p1, p2 peer.ID) error {
+	ls := mn.LinksBetweenPeers(p1, p2)
+	if ls == nil {
+		return fmt.Errorf("no link between p1 and p2")
+	}
+
+	for _, l := range ls {
+		if err := mn.Unlink(l); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+func (mn *mocknet) UnlinkNets(n1, n2 inet.Network) error {
+	return mn.UnlinkPeers(n1.LocalPeer(), n2.LocalPeer())
+}
+
+// get from the links map. and lazily contruct.
+func (mn *mocknet) linksMapGet(p1, p2 peer.ID) *map[*link]struct{} {
+
+	l1, found := mn.links[p1]
+	if !found {
+		mn.links[p1] = map[peer.ID]map[*link]struct{}{}
+		l1 = mn.links[p1] // so we make sure it's there.
+	}
+
+	l2, found := l1[p2]
+	if !found {
+		m := map[*link]struct{}{}
+		l1[p2] = m
+		l2 = l1[p2]
+	}
+
+	return &l2
+}
+
+func (mn *mocknet) addLink(l *link) {
+	mn.Lock()
+	defer mn.Unlock()
+
+	n1, n2 := l.nets[0], l.nets[1]
+	(*mn.linksMapGet(n1.peer, n2.peer))[l] = struct{}{}
+	(*mn.linksMapGet(n2.peer, n1.peer))[l] = struct{}{}
+}
+
+func (mn *mocknet) removeLink(l *link) {
+	mn.Lock()
+	defer mn.Unlock()
+
+	n1, n2 := l.nets[0], l.nets[1]
+	delete(*mn.linksMapGet(n1.peer, n2.peer), l)
+	delete(*mn.linksMapGet(n2.peer, n1.peer), l)
+}
+
+func (mn *mocknet) ConnectAll() error {
+	nets := mn.Nets()
+	for _, n1 := range nets {
+		for _, n2 := range nets {
+			if n1 == n2 {
+				continue
+			}
+
+			if err := mn.ConnectNets(n1, n2); err != nil {
+				return err
+			}
+		}
+	}
+	return nil
+}
+
+func (mn *mocknet) ConnectPeers(a, b peer.ID) error {
+	return mn.Net(a).DialPeer(mn.cg.Context(), b)
+}
+
+func (mn *mocknet) ConnectNets(a, b inet.Network) error {
+	return a.DialPeer(mn.cg.Context(), b.LocalPeer())
+}
+
+func (mn *mocknet) DisconnectPeers(p1, p2 peer.ID) error {
+	return mn.Net(p1).ClosePeer(p2)
+}
+
+func (mn *mocknet) DisconnectNets(n1, n2 inet.Network) error {
+	return n1.ClosePeer(n2.LocalPeer())
+}
+
+func (mn *mocknet) LinksBetweenPeers(p1, p2 peer.ID) []Link {
+	mn.RLock()
+	defer mn.RUnlock()
+
+	ls2 := *mn.linksMapGet(p1, p2)
+	cp := make([]Link, 0, len(ls2))
+	for l := range ls2 {
+		cp = append(cp, l)
+	}
+	return cp
+}
+
+func (mn *mocknet) LinksBetweenNets(n1, n2 inet.Network) []Link {
+	return mn.LinksBetweenPeers(n1.LocalPeer(), n2.LocalPeer())
+}
+
+func (mn *mocknet) SetLinkDefaults(o LinkOptions) {
+	mn.Lock()
+	mn.linkDefaults = o
+	mn.Unlock()
+}
+
+func (mn *mocknet) LinkDefaults() LinkOptions {
+	mn.RLock()
+	defer mn.RUnlock()
+	return mn.linkDefaults
+}

net/mock/mock_peernet.go

+package mocknet
+
+import (
+	"fmt"
+	"math/rand"
+	"sync"
+
+	ic "github.com/jbenet/go-ipfs/p2p/crypto"
+	inet "github.com/jbenet/go-ipfs/p2p/net"
+	ids "github.com/jbenet/go-ipfs/p2p/net/services/identify"
+	mux "github.com/jbenet/go-ipfs/p2p/net/services/mux"
+	relay "github.com/jbenet/go-ipfs/p2p/net/services/relay"
+	peer "github.com/jbenet/go-ipfs/p2p/peer"
+
+	context "github.com/jbenet/go-ipfs/Godeps/_workspace/src/code.google.com/p/go.net/context"
+	ctxgroup "github.com/jbenet/go-ipfs/Godeps/_workspace/src/github.com/jbenet/go-ctxgroup"
+	ma "github.com/jbenet/go-ipfs/Godeps/_workspace/src/github.com/jbenet/go-multiaddr"
+)
+
+// peernet implements inet.Network
+type peernet struct {
+	mocknet *mocknet // parent
+
+	peer peer.ID
+	ps   peer.Peerstore
+
+	// conns are actual live connections between peers.
+	// many conns could run over each link.
+	// **conns are NOT shared between peers**
+	connsByPeer map[peer.ID]map[*conn]struct{}
+	connsByLink map[*link]map[*conn]struct{}
+
+	// needed to implement inet.Network
+	mux   mux.Mux
+	ids   *ids.IDService
+	relay *relay.RelayService
+
+	cg ctxgroup.ContextGroup
+	sync.RWMutex
+}
+
+// newPeernet constructs a new peernet
+func newPeernet(ctx context.Context, m *mocknet, k ic.PrivKey,
+	a ma.Multiaddr) (*peernet, error) {
+
+	p, err := peer.IDFromPublicKey(k.GetPublic())
+	if err != nil {
+		return nil, err
+	}
+
+	// create our own entirely, so that peers knowledge doesn't get shared
+	ps := peer.NewPeerstore()
+	ps.AddAddress(p, a)
+	ps.AddPrivKey(p, k)
+	ps.AddPubKey(p, k.GetPublic())
+
+	n := &peernet{
+		mocknet: m,
+		peer:    p,
+		ps:      ps,
+		mux:     mux.Mux{Handlers: inet.StreamHandlerMap{}},
+		cg:      ctxgroup.WithContext(ctx),
+
+		connsByPeer: map[peer.ID]map[*conn]struct{}{},
+		connsByLink: map[*link]map[*conn]struct{}{},
+	}
+
+	n.cg.SetTeardown(n.teardown)
+
+	// setup a conn handler that immediately "asks the other side about them"
+	// this is ProtocolIdentify.
+	n.ids = ids.NewIDService(n)
+
+	// setup ProtocolRelay to allow traffic relaying.
+	// Feed things we get for ourselves into the muxer.
+	n.relay = relay.NewRelayService(n.cg.Context(), n, n.mux.HandleSync)
+	return n, nil
+}
+
+func (pn *peernet) teardown() error {
+
+	// close the connections
+	for _, c := range pn.allConns() {
+		c.Close()
+	}
+	return nil
+}
+
+// allConns returns all the connections between this peer and others
+func (pn *peernet) allConns() []*conn {
+	pn.RLock()
+	var cs []*conn
+	for _, csl := range pn.connsByPeer {
+		for c := range csl {
+			cs = append(cs, c)
+		}
+	}
+	pn.RUnlock()
+	return cs
+}
+
+// Close calls the ContextCloser func
+func (pn *peernet) Close() error {
+	return pn.cg.Close()
+}
+
+func (pn *peernet) Protocols() []inet.ProtocolID {
+	return pn.mux.Protocols()
+}
+
+func (pn *peernet) Peerstore() peer.Peerstore {
+	return pn.ps
+}
+
+func (pn *peernet) String() string {
+	return fmt.Sprintf("<mock.peernet %s - %d conns>", pn.peer, len(pn.allConns()))
+}
+
+// handleNewStream is an internal function to trigger the muxer handler
+func (pn *peernet) handleNewStream(s inet.Stream) {
+	go pn.mux.Handle(s)
+}
+
+// DialPeer attempts to establish a connection to a given peer.
+// Respects the context.
+func (pn *peernet) DialPeer(ctx context.Context, p peer.ID) error {
+	return pn.connect(p)
+}
+
+func (pn *peernet) connect(p peer.ID) error {
+	// first, check if we already have live connections
+	pn.RLock()
+	cs, found := pn.connsByPeer[p]
+	pn.RUnlock()
+	if found && len(cs) > 0 {
+		return nil
+	}
+
+	log.Debugf("%s (newly) dialing %s", pn.peer, p)
+
+	// ok, must create a new connection. we need a link
+	links := pn.mocknet.LinksBetweenPeers(pn.peer, p)
+	if len(links) < 1 {
+		return fmt.Errorf("%s cannot connect to %s", pn.peer, p)
+	}
+
+	// if many links found, how do we select? for now, randomly...
+	// this would be an interesting place to test logic that can measure
+	// links (network interfaces) and select properly
+	l := links[rand.Intn(len(links))]
+
+	log.Debugf("%s dialing %s openingConn", pn.peer, p)
+	// create a new connection with link
+	pn.openConn(p, l.(*link))
+	return nil
+}
+
+func (pn *peernet) openConn(r peer.ID, l *link) *conn {
+	lc, rc := l.newConnPair(pn)
+	log.Debugf("%s opening connection to %s", pn.LocalPeer(), lc.RemotePeer())
+	pn.addConn(lc)
+	rc.net.remoteOpenedConn(rc)
+	return lc
+}
+
+func (pn *peernet) remoteOpenedConn(c *conn) {
+	log.Debugf("%s accepting connection from %s", pn.LocalPeer(), c.RemotePeer())
+	pn.addConn(c)
+}
+
+// addConn constructs and adds a connection
+// to given remote peer over given link
+func (pn *peernet) addConn(c *conn) {
+
+	// run the Identify protocol/handshake.
+	pn.ids.IdentifyConn(c)
+
+	pn.Lock()
+	cs, found := pn.connsByPeer[c.RemotePeer()]
+	if !found {
+		cs = map[*conn]struct{}{}
+		pn.connsByPeer[c.RemotePeer()] = cs
+	}
+	pn.connsByPeer[c.RemotePeer()][c] = struct{}{}
+
+	cs, found = pn.connsByLink[c.link]
+	if !found {
+		cs = map[*conn]struct{}{}
+		pn.connsByLink[c.link] = cs
+	}
+	pn.connsByLink[c.link][c] = struct{}{}
+	pn.Unlock()
+}
+
+// removeConn removes a given conn
+func (pn *peernet) removeConn(c *conn) {
+	pn.Lock()
+	defer pn.Unlock()
+
+	cs, found := pn.connsByLink[c.link]
+	if !found || len(cs) < 1 {
+		panic("attempting to remove a conn that doesnt exist")
+	}
+	delete(cs, c)
+
+	cs, found = pn.connsByPeer[c.remote]
+	if !found {
+		panic("attempting to remove a conn that doesnt exist")
+	}
+	delete(cs, c)
+}
+
+// CtxGroup returns the network's ContextGroup
+func (pn *peernet) CtxGroup() ctxgroup.ContextGroup {
+	return pn.cg
+}
+
+// LocalPeer the network's LocalPeer
+func (pn *peernet) LocalPeer() peer.ID {
+	return pn.peer
+}
+
+// Peers returns the connected peers
+func (pn *peernet) Peers() []peer.ID {
+	pn.RLock()
+	defer pn.RUnlock()
+
+	peers := make([]peer.ID, 0, len(pn.connsByPeer))
+	for _, cs := range pn.connsByPeer {
+		for c := range cs {
+			peers = append(peers, c.remote)
+			break
+		}
+	}
+	return peers
+}
+
+// Conns returns all the connections of this peer
+func (pn *peernet) Conns() []inet.Conn {
+	pn.RLock()
+	defer pn.RUnlock()
+
+	out := make([]inet.Conn, 0, len(pn.connsByPeer))
+	for _, cs := range pn.connsByPeer {
+		for c := range cs {
+			out = append(out, c)
+		}
+	}
+	return out
+}
+
+func (pn *peernet) ConnsToPeer(p peer.ID) []inet.Conn {
+	pn.RLock()
+	defer pn.RUnlock()
+
+	cs, found := pn.connsByPeer[p]
+	if !found || len(cs) == 0 {
+		return nil
+	}
+
+	var cs2 []inet.Conn
+	for c := range cs {
+		cs2 = append(cs2, c)
+	}
+	return cs2
+}
+
+// ClosePeer connections to peer
+func (pn *peernet) ClosePeer(p peer.ID) error {
+	pn.RLock()
+	cs, found := pn.connsByPeer[p]
+	pn.RUnlock()
+	if !found {
+		return nil
+	}
+
+	for c := range cs {
+		c.Close()
+	}
+	return nil
+}
+
+// BandwidthTotals returns the total amount of bandwidth transferred
+func (pn *peernet) BandwidthTotals() (in uint64, out uint64) {
+	// need to implement this. probably best to do it in swarm this time.
+	// need a "metrics" object
+	return 0, 0
+}
+
+// ListenAddresses returns a list of addresses at which this network listens.
+func (pn *peernet) ListenAddresses() []ma.Multiaddr {
+	return pn.Peerstore().Addresses(pn.LocalPeer())
+}
+
+// InterfaceListenAddresses returns a list of addresses at which this network
+// listens. It expands "any interface" addresses (/ip4/0.0.0.0, /ip6/::) to
+// use the known local interfaces.
+func (pn *peernet) InterfaceListenAddresses() ([]ma.Multiaddr, error) {
+	return pn.ListenAddresses(), nil
+}
+
+// Connectedness returns a state signaling connection capabilities
+// For now only returns Connecter || NotConnected. Expand into more later.
+func (pn *peernet) Connectedness(p peer.ID) inet.Connectedness {
+	pn.Lock()
+	defer pn.Unlock()
+
+	cs, found := pn.connsByPeer[p]
+	if found && len(cs) > 0 {
+		return inet.Connected
+	}
+	return inet.NotConnected
+}
+
+// NewStream returns a new stream to given peer p.
+// If there is no connection to p, attempts to create one.
+// If ProtocolID is "", writes no header.
+func (pn *peernet) NewStream(pr inet.ProtocolID, p peer.ID) (inet.Stream, error) {
+	pn.Lock()
+	defer pn.Unlock()
+
+	cs, found := pn.connsByPeer[p]
+	if !found || len(cs) < 1 {
+		return nil, fmt.Errorf("no connection to peer")
+	}
+
+	// if many conns are found, how do we select? for now, randomly...
+	// this would be an interesting place to test logic that can measure
+	// links (network interfaces) and select properly
+	n := rand.Intn(len(cs))
+	var c *conn
+	for c = range cs {
+		if n == 0 {
+			break
+		}
+		n--
+	}
+
+	return c.NewStreamWithProtocol(pr)
+}
+
+// SetHandler sets the protocol handler on the Network's Muxer.
+// This operation is threadsafe.
+func (pn *peernet) SetHandler(p inet.ProtocolID, h inet.StreamHandler) {
+	pn.mux.SetHandler(p, h)
+}
+
+func (pn *peernet) IdentifyProtocol() *ids.IDService {
+	return pn.ids
+}

net/mock/mock_printer.go

+package mocknet
+
+import (
+	"fmt"
+	"io"
+
+	inet "github.com/jbenet/go-ipfs/p2p/net"
+	peer "github.com/jbenet/go-ipfs/p2p/peer"
+)
+
+// separate object so our interfaces are separate :)
+type printer struct {
+	w io.Writer
+}
+
+func (p *printer) MocknetLinks(mn Mocknet) {
+	links := mn.Links()
+
+	fmt.Fprintf(p.w, "Mocknet link map:\n")
+	for p1, lm := range links {
+		fmt.Fprintf(p.w, "\t%s linked to:\n", peer.ID(p1))
+		for p2, l := range lm {
+			fmt.Fprintf(p.w, "\t\t%s (%d links)\n", peer.ID(p2), len(l))
+		}
+	}
+	fmt.Fprintf(p.w, "\n")
+}
+
+func (p *printer) NetworkConns(ni inet.Network) {
+
+	fmt.Fprintf(p.w, "%s connected to:\n", ni.LocalPeer())
+	for _, c := range ni.Conns() {
+		fmt.Fprintf(p.w, "\t%s (addr: %s)\n", c.RemotePeer(), c.RemoteMultiaddr())
+	}
+	fmt.Fprintf(p.w, "\n")
+}

net/mock/mock_stream.go

+package mocknet
+
+import (
+	"io"
+
+	inet "github.com/jbenet/go-ipfs/p2p/net"
+)
+
+// stream implements inet.Stream
+type stream struct {
+	io.Reader
+	io.Writer
+	conn *conn
+}
+
+func (s *stream) Close() error {
+	s.conn.removeStream(s)
+	if r, ok := (s.Reader).(io.Closer); ok {
+		r.Close()
+	}
+	if w, ok := (s.Writer).(io.Closer); ok {
+		return w.Close()
+	}
+	return nil
+}
+
+func (s *stream) Conn() inet.Conn {
+	return s.conn
+}

net/mock/mock_test.go

+package mocknet
+
+import (
+	"bytes"
+	"io"
+	"math/rand"
+	"sync"
+	"testing"
+
+	inet "github.com/jbenet/go-ipfs/p2p/net"
+	peer "github.com/jbenet/go-ipfs/p2p/peer"
+	testutil "github.com/jbenet/go-ipfs/util/testutil"
+
+	context "github.com/jbenet/go-ipfs/Godeps/_workspace/src/code.google.com/p/go.net/context"
+)
+
+func randPeer(t *testing.T) peer.ID {
+	p, err := testutil.RandPeerID()
+	if err != nil {
+		t.Fatal(err)
+	}
+	return p
+}
+
+func TestNetworkSetup(t *testing.T) {
+
+	ctx := context.Background()
+	sk1, _, err := testutil.RandKeyPair(512)
+	if err != nil {
+		t.Fatal(t)
+	}
+	sk2, _, err := testutil.RandKeyPair(512)
+	if err != nil {
+		t.Fatal(t)
+	}
+	sk3, _, err := testutil.RandKeyPair(512)
+	if err != nil {
+		t.Fatal(t)
+	}
+	mn := New(ctx)
+	// peers := []peer.ID{p1, p2, p3}
+
+	// add peers to mock net
+
+	a1 := testutil.RandLocalTCPAddress()
+	a2 := testutil.RandLocalTCPAddress()
+	a3 := testutil.RandLocalTCPAddress()
+
+	n1, err := mn.AddPeer(sk1, a1)
+	if err != nil {
+		t.Fatal(err)
+	}
+	p1 := n1.LocalPeer()
+
+	n2, err := mn.AddPeer(sk2, a2)
+	if err != nil {
+		t.Fatal(err)
+	}
+	p2 := n2.LocalPeer()
+
+	n3, err := mn.AddPeer(sk3, a3)
+	if err != nil {
+		t.Fatal(err)
+	}
+	p3 := n3.LocalPeer()
+
+	// check peers and net
+	if mn.Net(p1) != n1 {
+		t.Error("net for p1.ID != n1")
+	}
+	if mn.Net(p2) != n2 {
+		t.Error("net for p2.ID != n1")
+	}
+	if mn.Net(p3) != n3 {
+		t.Error("net for p3.ID != n1")
+	}
+
+	// link p1<-->p2, p1<-->p1, p2<-->p3, p3<-->p2
+
+	l12, err := mn.LinkPeers(p1, p2)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if !(l12.Networks()[0] == n1 && l12.Networks()[1] == n2) &&
+		!(l12.Networks()[0] == n2 && l12.Networks()[1] == n1) {
+		t.Error("l12 networks incorrect")
+	}
+
+	l11, err := mn.LinkPeers(p1, p1)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if !(l11.Networks()[0] == n1 && l11.Networks()[1] == n1) {
+		t.Error("l11 networks incorrect")
+	}
+
+	l23, err := mn.LinkPeers(p2, p3)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if !(l23.Networks()[0] == n2 && l23.Networks()[1] == n3) &&
+		!(l23.Networks()[0] == n3 && l23.Networks()[1] == n2) {
+		t.Error("l23 networks incorrect")
+	}
+
+	l32, err := mn.LinkPeers(p3, p2)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if !(l32.Networks()[0] == n2 && l32.Networks()[1] == n3) &&
+		!(l32.Networks()[0] == n3 && l32.Networks()[1] == n2) {
+		t.Error("l32 networks incorrect")
+	}
+
+	// check things
+
+	links12 := mn.LinksBetweenPeers(p1, p2)
+	if len(links12) != 1 {
+		t.Errorf("should be 1 link bt. p1 and p2 (found %d)", len(links12))
+	}
+	if links12[0] != l12 {
+		t.Error("links 1-2 should be l12.")
+	}
+
+	links11 := mn.LinksBetweenPeers(p1, p1)
+	if len(links11) != 1 {
+		t.Errorf("should be 1 link bt. p1 and p1 (found %d)", len(links11))
+	}
+	if links11[0] != l11 {
+		t.Error("links 1-1 should be l11.")
+	}
+
+	links23 := mn.LinksBetweenPeers(p2, p3)
+	if len(links23) != 2 {
+		t.Errorf("should be 2 link bt. p2 and p3 (found %d)", len(links23))
+	}
+	if !((links23[0] == l23 && links23[1] == l32) ||
+		(links23[0] == l32 && links23[1] == l23)) {
+		t.Error("links 2-3 should be l23 and l32.")
+	}
+
+	// unlinking
+
+	if err := mn.UnlinkPeers(p2, p1); err != nil {
+		t.Error(err)
+	}
+
+	// check only one link affected:
+
+	links12 = mn.LinksBetweenPeers(p1, p2)
+	if len(links12) != 0 {
+		t.Errorf("should be 0 now...", len(links12))
+	}
+
+	links11 = mn.LinksBetweenPeers(p1, p1)
+	if len(links11) != 1 {
+		t.Errorf("should be 1 link bt. p1 and p1 (found %d)", len(links11))
+	}
+	if links11[0] != l11 {
+		t.Error("links 1-1 should be l11.")
+	}
+
+	links23 = mn.LinksBetweenPeers(p2, p3)
+	if len(links23) != 2 {
+		t.Errorf("should be 2 link bt. p2 and p3 (found %d)", len(links23))
+	}
+	if !((links23[0] == l23 && links23[1] == l32) ||
+		(links23[0] == l32 && links23[1] == l23)) {
+		t.Error("links 2-3 should be l23 and l32.")
+	}
+
+	// check connecting
+
+	// first, no conns
+	if len(n2.Conns()) > 0 || len(n3.Conns()) > 0 {
+		t.Error("should have 0 conn. Got: (%d, %d)", len(n2.Conns()), len(n3.Conns()))
+	}
+
+	// connect p2->p3
+	if err := n2.DialPeer(ctx, p3); err != nil {
+		t.Error(err)
+	}
+
+	if len(n2.Conns()) != 1 || len(n3.Conns()) != 1 {
+		t.Errorf("should have (1,1) conn. Got: (%d, %d)", len(n2.Conns()), len(n3.Conns()))
+	}
+
+	// p := PrinterTo(os.Stdout)
+	// p.NetworkConns(n1)
+	// p.NetworkConns(n2)
+	// p.NetworkConns(n3)
+
+	// can create a stream 2->3, 3->2,
+	if _, err := n2.NewStream(inet.ProtocolDiag, p3); err != nil {
+		t.Error(err)
+	}
+	if _, err := n3.NewStream(inet.ProtocolDiag, p2); err != nil {
+		t.Error(err)
+	}
+
+	// but not 1->2 nor 2->2 (not linked), nor 1->1 (not connected)
+	if _, err := n1.NewStream(inet.ProtocolDiag, p2); err == nil {
+		t.Error("should not be able to connect")
+	}
+	if _, err := n2.NewStream(inet.ProtocolDiag, p2); err == nil {
+		t.Error("should not be able to connect")
+	}
+	if _, err := n1.NewStream(inet.ProtocolDiag, p1); err == nil {
+		t.Error("should not be able to connect")
+	}
+
+	// connect p1->p1 (should work)
+	if err := n1.DialPeer(ctx, p1); err != nil {
+		t.Error("p1 should be able to dial self.", err)
+	}
+
+	// and a stream too
+	if _, err := n1.NewStream(inet.ProtocolDiag, p1); err != nil {
+		t.Error(err)
+	}
+
+	// connect p1->p2
+	if err := n1.DialPeer(ctx, p2); err == nil {
+		t.Error("p1 should not be able to dial p2, not connected...")
+	}
+
+	// connect p3->p1
+	if err := n3.DialPeer(ctx, p1); err == nil {
+		t.Error("p3 should not be able to dial p1, not connected...")
+	}
+
+	// relink p1->p2
+
+	l12, err = mn.LinkPeers(p1, p2)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if !(l12.Networks()[0] == n1 && l12.Networks()[1] == n2) &&
+		!(l12.Networks()[0] == n2 && l12.Networks()[1] == n1) {
+		t.Error("l12 networks incorrect")
+	}
+
+	// should now be able to connect
+
+	// connect p1->p2
+	if err := n1.DialPeer(ctx, p2); err != nil {
+		t.Error(err)
+	}
+
+	// and a stream should work now too :)
+	if _, err := n2.NewStream(inet.ProtocolDiag, p3); err != nil {
+		t.Error(err)
+	}
+
+}
+
+func TestStreams(t *testing.T) {
+
+	mn, err := FullMeshConnected(context.Background(), 3)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	handler := func(s inet.Stream) {
+		go func() {
+			b := make([]byte, 4)
+			if _, err := io.ReadFull(s, b); err != nil {
+				panic(err)
+			}
+			if !bytes.Equal(b, []byte("beep")) {
+				panic("bytes mismatch")
+			}
+			if _, err := s.Write([]byte("boop")); err != nil {
+				panic(err)
+			}
+			s.Close()
+		}()
+	}
+
+	nets := mn.Nets()
+	for _, n := range nets {
+		n.SetHandler(inet.ProtocolDHT, handler)
+	}
+
+	s, err := nets[0].NewStream(inet.ProtocolDHT, nets[1].LocalPeer())
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if _, err := s.Write([]byte("beep")); err != nil {
+		panic(err)
+	}
+	b := make([]byte, 4)
+	if _, err := io.ReadFull(s, b); err != nil {
+		panic(err)
+	}
+	if !bytes.Equal(b, []byte("boop")) {
+		panic("bytes mismatch 2")
+	}
+
+}
+
+func makePinger(st string, n int) func(inet.Stream) {
+	return func(s inet.Stream) {
+		go func() {
+			defer s.Close()
+
+			for i := 0; i < n; i++ {
+				b := make([]byte, 4+len(st))
+				if _, err := s.Write([]byte("ping" + st)); err != nil {
+					panic(err)
+				}
+				if _, err := io.ReadFull(s, b); err != nil {
+					panic(err)
+				}
+				if !bytes.Equal(b, []byte("pong"+st)) {
+					panic("bytes mismatch")
+				}
+			}
+		}()
+	}
+}
+
+func makePonger(st string) func(inet.Stream) {
+	return func(s inet.Stream) {
+		go func() {
+			defer s.Close()
+
+			for {
+				b := make([]byte, 4+len(st))
+				if _, err := io.ReadFull(s, b); err != nil {
+					if err == io.EOF {
+						return
+					}
+					panic(err)
+				}
+				if !bytes.Equal(b, []byte("ping"+st)) {
+					panic("bytes mismatch")
+				}
+				if _, err := s.Write([]byte("pong" + st)); err != nil {
+					panic(err)
+				}
+			}
+		}()
+	}
+}
+
+func TestStreamsStress(t *testing.T) {
+
+	mn, err := FullMeshConnected(context.Background(), 100)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	protos := []inet.ProtocolID{
+		inet.ProtocolDHT,
+		inet.ProtocolBitswap,
+		inet.ProtocolDiag,
+	}
+
+	nets := mn.Nets()
+	for _, n := range nets {
+		for _, p := range protos {
+			n.SetHandler(p, makePonger(string(p)))
+		}
+	}
+
+	var wg sync.WaitGroup
+	for i := 0; i < 1000; i++ {
+		wg.Add(1)
+		go func(i int) {
+			defer wg.Done()
+			from := rand.Intn(len(nets))
+			to := rand.Intn(len(nets))
+			p := rand.Intn(3)
+			proto := protos[p]
+			s, err := nets[from].NewStream(protos[p], nets[to].LocalPeer())
+			if err != nil {
+				log.Debugf("%d (%s) %d (%s) %d (%s)", from, nets[from], to, nets[to], p, protos[p])
+				panic(err)
+			}
+
+			log.Infof("%d start pinging", i)
+			makePinger(string(proto), rand.Intn(100))(s)
+			log.Infof("%d done pinging", i)
+		}(i)
+	}
+
+	wg.Wait()
+}
+
+func TestAdding(t *testing.T) {
+
+	mn := New(context.Background())
+
+	peers := []peer.ID{}
+	for i := 0; i < 3; i++ {
+		sk, _, err := testutil.RandKeyPair(512)
+		if err != nil {
+			t.Fatal(err)
+		}
+
+		a := testutil.RandLocalTCPAddress()
+		n, err := mn.AddPeer(sk, a)
+		if err != nil {
+			t.Fatal(err)
+		}
+
+		peers = append(peers, n.LocalPeer())
+	}
+
+	p1 := peers[0]
+	p2 := peers[1]
+
+	// link them
+	for _, p1 := range peers {
+		for _, p2 := range peers {
+			if _, err := mn.LinkPeers(p1, p2); err != nil {
+				t.Error(err)
+			}
+		}
+	}
+
+	// set the new stream handler on p2
+	n2 := mn.Net(p2)
+	if n2 == nil {
+		t.Fatalf("no network for %s", p2)
+	}
+	n2.SetHandler(inet.ProtocolBitswap, func(s inet.Stream) {
+		go func() {
+			defer s.Close()
+
+			b := make([]byte, 4)
+			if _, err := io.ReadFull(s, b); err != nil {
+				panic(err)
+			}
+			if string(b) != "beep" {
+				panic("did not beep!")
+			}
+
+			if _, err := s.Write([]byte("boop")); err != nil {
+				panic(err)
+			}
+		}()
+	})
+
+	// connect p1 to p2
+	if err := mn.ConnectPeers(p1, p2); err != nil {
+		t.Fatal(err)
+	}
+
+	// talk to p2
+	n1 := mn.Net(p1)
+	if n1 == nil {
+		t.Fatalf("no network for %s", p1)
+	}
+
+	s, err := n1.NewStream(inet.ProtocolBitswap, p2)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if _, err := s.Write([]byte("beep")); err != nil {
+		t.Error(err)
+	}
+	b := make([]byte, 4)
+	if _, err := io.ReadFull(s, b); err != nil {
+		t.Error(err)
+	}
+	if !bytes.Equal(b, []byte("boop")) {
+		t.Error("bytes mismatch 2")
+	}
+
+}

net/services/identify/id.go

+package identify
+
+import (
+	"sync"
+
+	ggio "github.com/jbenet/go-ipfs/Godeps/_workspace/src/code.google.com/p/gogoprotobuf/io"
+	ma "github.com/jbenet/go-ipfs/Godeps/_workspace/src/github.com/jbenet/go-multiaddr"
+
+	inet "github.com/jbenet/go-ipfs/p2p/net"
+	handshake "github.com/jbenet/go-ipfs/p2p/net/handshake"
+	pb "github.com/jbenet/go-ipfs/p2p/net/handshake/pb"
+	eventlog "github.com/jbenet/go-ipfs/util/eventlog"
+)
+
+var log = eventlog.Logger("net/identify")
+
+// ProtocolIdentify is the ProtocolID of the Identify Service.
+const ProtocolIdentify inet.ProtocolID = "/ipfs/identify"
+
+// IDService is a structure that implements ProtocolIdentify.
+// It is a trivial service that gives the other peer some
+// useful information about the local peer. A sort of hello.
+//
+// The IDService sends:
+//  * Our IPFS Protocol Version
+//  * Our IPFS Agent Version
+//  * Our public Listen Addresses
+type IDService struct {
+	Network inet.Network
+
+	// connections undergoing identification
+	// for wait purposes
+	currid map[inet.Conn]chan struct{}
+	currmu sync.RWMutex
+}
+
+func NewIDService(n inet.Network) *IDService {
+	s := &IDService{
+		Network: n,
+		currid:  make(map[inet.Conn]chan struct{}),
+	}
+	n.SetHandler(ProtocolIdentify, s.RequestHandler)
+	return s
+}
+
+func (ids *IDService) IdentifyConn(c inet.Conn) {
+	ids.currmu.Lock()
+	if wait, found := ids.currid[c]; found {
+		ids.currmu.Unlock()
+		log.Debugf("IdentifyConn called twice on: %s", c)
+		<-wait // already identifying it. wait for it.
+		return
+	}
+	ids.currid[c] = make(chan struct{})
+	ids.currmu.Unlock()
+
+	s, err := c.NewStreamWithProtocol(ProtocolIdentify)
+	if err != nil {
+		log.Error("network: unable to open initial stream for %s", ProtocolIdentify)
+		log.Event(ids.Network.CtxGroup().Context(), "IdentifyOpenFailed", c.RemotePeer())
+	} else {
+
+		// ok give the response to our handler.
+		ids.ResponseHandler(s)
+	}
+
+	ids.currmu.Lock()
+	ch, found := ids.currid[c]
+	delete(ids.currid, c)
+	ids.currmu.Unlock()
+
+	if !found {
+		log.Errorf("IdentifyConn failed to find channel (programmer error) for %s", c)
+		return
+	}
+
+	close(ch) // release everyone waiting.
+}
+
+func (ids *IDService) RequestHandler(s inet.Stream) {
+	defer s.Close()
+	c := s.Conn()
+
+	w := ggio.NewDelimitedWriter(s)
+	mes := pb.Handshake3{}
+	ids.populateMessage(&mes, s.Conn())
+	w.WriteMsg(&mes)
+
+	log.Debugf("%s sent message to %s %s", ProtocolIdentify,
+		c.RemotePeer(), c.RemoteMultiaddr())
+}
+
+func (ids *IDService) ResponseHandler(s inet.Stream) {
+	defer s.Close()
+	c := s.Conn()
+
+	r := ggio.NewDelimitedReader(s, 2048)
+	mes := pb.Handshake3{}
+	if err := r.ReadMsg(&mes); err != nil {
+		log.Errorf("%s error receiving message from %s %s", ProtocolIdentify,
+			c.RemotePeer(), c.RemoteMultiaddr())
+		return
+	}
+	ids.consumeMessage(&mes, c)
+
+	log.Debugf("%s received message from %s %s", ProtocolIdentify,
+		c.RemotePeer(), c.RemoteMultiaddr())
+}
+
+func (ids *IDService) populateMessage(mes *pb.Handshake3, c inet.Conn) {
+
+	// set protocols this node is currently handling
+	protos := ids.Network.Protocols()
+	mes.Protocols = make([]string, len(protos))
+	for i, p := range protos {
+		mes.Protocols[i] = string(p)
+	}
+
+	// observed address so other side is informed of their
+	// "public" address, at least in relation to us.
+	mes.ObservedAddr = c.RemoteMultiaddr().Bytes()
+
+	// set listen addrs
+	laddrs, err := ids.Network.InterfaceListenAddresses()
+	if err != nil {
+		log.Error(err)
+	} else {
+		mes.ListenAddrs = make([][]byte, len(laddrs))
+		for i, addr := range laddrs {
+			mes.ListenAddrs[i] = addr.Bytes()
+		}
+		log.Debugf("%s sent listen addrs to %s: %s", c.LocalPeer(), c.RemotePeer(), laddrs)
+	}
+
+	// set protocol versions
+	mes.H1 = handshake.NewHandshake1("", "")
+}
+
+func (ids *IDService) consumeMessage(mes *pb.Handshake3, c inet.Conn) {
+	p := c.RemotePeer()
+
+	// mes.Protocols
+	// mes.ObservedAddr
+
+	// mes.ListenAddrs
+	laddrs := mes.GetListenAddrs()
+	lmaddrs := make([]ma.Multiaddr, 0, len(laddrs))
+	for _, addr := range laddrs {
+		maddr, err := ma.NewMultiaddrBytes(addr)
+		if err != nil {
+			log.Errorf("%s failed to parse multiaddr from %s %s", ProtocolIdentify, p,
+				c.RemoteMultiaddr())
+			continue
+		}
+		lmaddrs = append(lmaddrs, maddr)
+	}
+
+	// update our peerstore with the addresses.
+	ids.Network.Peerstore().AddAddresses(p, lmaddrs)
+	log.Debugf("%s received listen addrs for %s: %s", c.LocalPeer(), c.RemotePeer(), lmaddrs)
+
+	// get protocol versions
+	pv := *mes.H1.ProtocolVersion
+	av := *mes.H1.AgentVersion
+	ids.Network.Peerstore().Put(p, "ProtocolVersion", pv)
+	ids.Network.Peerstore().Put(p, "AgentVersion", av)
+}
+
+// IdentifyWait returns a channel which will be closed once
+// "ProtocolIdentify" (handshake3) finishes on given conn.
+// This happens async so the connection can start to be used
+// even if handshake3 knowledge is not necesary.
+// Users **MUST** call IdentifyWait _after_ IdentifyConn
+func (ids *IDService) IdentifyWait(c inet.Conn) <-chan struct{} {
+	ids.currmu.Lock()
+	ch, found := ids.currid[c]
+	ids.currmu.Unlock()
+	if found {
+		return ch
+	}
+
+	// if not found, it means we are already done identifying it, or
+	// haven't even started. either way, return a new channel closed.
+	ch = make(chan struct{})
+	close(ch)
+	return ch
+}

net/services/identify/id_test.go

+package identify_test
+
+import (
+	"testing"
+	"time"
+
+	inet "github.com/jbenet/go-ipfs/p2p/net"
+	handshake "github.com/jbenet/go-ipfs/p2p/net/handshake"
+	netutil "github.com/jbenet/go-ipfs/p2p/net/swarmnet/util"
+	peer "github.com/jbenet/go-ipfs/p2p/peer"
+
+	context "github.com/jbenet/go-ipfs/Godeps/_workspace/src/code.google.com/p/go.net/context"
+	ma "github.com/jbenet/go-ipfs/Godeps/_workspace/src/github.com/jbenet/go-multiaddr"
+)
+
+func subtestIDService(t *testing.T, postDialWait time.Duration) {
+
+	// the generated networks should have the id service wired in.
+	ctx := context.Background()
+	n1 := netutil.GenNetwork(t, ctx)
+	n2 := netutil.GenNetwork(t, ctx)
+
+	n1p := n1.LocalPeer()
+	n2p := n2.LocalPeer()
+
+	testKnowsAddrs(t, n1, n2p, []ma.Multiaddr{}) // nothing
+	testKnowsAddrs(t, n2, n1p, []ma.Multiaddr{}) // nothing
+
+	// have n2 tell n1, so we can dial...
+	netutil.DivulgeAddresses(n2, n1)
+
+	testKnowsAddrs(t, n1, n2p, n2.Peerstore().Addresses(n2p)) // has them
+	testKnowsAddrs(t, n2, n1p, []ma.Multiaddr{})              // nothing
+
+	if err := n1.DialPeer(ctx, n2p); err != nil {
+		t.Fatalf("Failed to dial:", err)
+	}
+
+	// we need to wait here if Dial returns before ID service is finished.
+	if postDialWait > 0 {
+		<-time.After(postDialWait)
+	}
+
+	// the IDService should be opened automatically, by the network.
+	// what we should see now is that both peers know about each others listen addresses.
+	testKnowsAddrs(t, n1, n2p, n2.Peerstore().Addresses(n2p)) // has them
+	testHasProtocolVersions(t, n1, n2p)
+
+	// now, this wait we do have to do. it's the wait for the Listening side
+	// to be done identifying the connection.
+	c := n2.ConnsToPeer(n1.LocalPeer())
+	if len(c) < 1 {
+		t.Fatal("should have connection by now at least.")
+	}
+	<-n2.IdentifyProtocol().IdentifyWait(c[0])
+
+	// and the protocol versions.
+	testKnowsAddrs(t, n2, n1p, n1.Peerstore().Addresses(n1p)) // has them
+	testHasProtocolVersions(t, n2, n1p)
+}
+
+func testKnowsAddrs(t *testing.T, n inet.Network, p peer.ID, expected []ma.Multiaddr) {
+	actual := n.Peerstore().Addresses(p)
+
+	if len(actual) != len(expected) {
+		t.Error("dont have the same addresses")
+	}
+
+	have := map[string]struct{}{}
+	for _, addr := range actual {
+		have[addr.String()] = struct{}{}
+	}
+	for _, addr := range expected {
+		if _, found := have[addr.String()]; !found {
+			t.Errorf("%s did not have addr for %s: %s", n.LocalPeer(), p, addr)
+			// panic("ahhhhhhh")
+		}
+	}
+}
+
+func testHasProtocolVersions(t *testing.T, n inet.Network, p peer.ID) {
+	v, err := n.Peerstore().Get(p, "ProtocolVersion")
+	if v == nil {
+		t.Error("no protocol version")
+		return
+	}
+	if v.(string) != handshake.IpfsVersion.String() {
+		t.Error("protocol mismatch", err)
+	}
+	v, err = n.Peerstore().Get(p, "AgentVersion")
+	if v.(string) != handshake.ClientVersion {
+		t.Error("agent version mismatch", err)
+	}
+}
+
+// TestIDServiceWait gives the ID service 100ms to finish after dialing
+// this is becasue it used to be concurrent. Now, Dial wait till the
+// id service is done.
+func TestIDServiceWait(t *testing.T) {
+	N := 3
+	for i := 0; i < N; i++ {
+		subtestIDService(t, 100*time.Millisecond)
+	}
+}
+
+func TestIDServiceNoWait(t *testing.T) {
+	N := 3
+	for i := 0; i < N; i++ {
+		subtestIDService(t, 0)
+	}
+}

net/services/mux/mux.go

+package mux
+
+import (
+	"fmt"
+	"io"
+	"sync"
+
+	context "github.com/jbenet/go-ipfs/Godeps/_workspace/src/code.google.com/p/go.net/context"
+
+	inet "github.com/jbenet/go-ipfs/p2p/net"
+	eventlog "github.com/jbenet/go-ipfs/util/eventlog"
+	lgbl "github.com/jbenet/go-ipfs/util/eventlog/loggables"
+)
+
+var log = eventlog.Logger("net/mux")
+
+// Mux provides simple stream multixplexing.
+// It helps you precisely when:
+//  * You have many streams
+//  * You have function handlers
+//
+// It contains the handlers for each protocol accepted.
+// It dispatches handlers for streams opened by remote peers.
+//
+// We use a totally ad-hoc encoding:
+//   <1 byte length in bytes><string name>
+// So "bitswap" is 0x0762697473776170
+//
+// NOTE: only the dialer specifies this muxing line.
+// This is because we're using Streams :)
+//
+// WARNING: this datastructure IS NOT threadsafe.
+// do not modify it once the network is using it.
+type Mux struct {
+	Default  inet.StreamHandler // handles unknown protocols.
+	Handlers inet.StreamHandlerMap
+
+	sync.RWMutex
+}
+
+// Protocols returns the list of protocols this muxer has handlers for
+func (m *Mux) Protocols() []inet.ProtocolID {
+	m.RLock()
+	l := make([]inet.ProtocolID, 0, len(m.Handlers))
+	for p := range m.Handlers {
+		l = append(l, p)
+	}
+	m.RUnlock()
+	return l
+}
+
+// ReadProtocolHeader reads the stream and returns the next Handler function
+// according to the muxer encoding.
+func (m *Mux) ReadProtocolHeader(s io.Reader) (string, inet.StreamHandler, error) {
+	// log.Error("ReadProtocolHeader")
+	name, err := ReadLengthPrefix(s)
+	if err != nil {
+		return "", nil, err
+	}
+
+	// log.Debug("ReadProtocolHeader got:", name)
+	m.RLock()
+	h, found := m.Handlers[inet.ProtocolID(name)]
+	m.RUnlock()
+
+	switch {
+	case !found && m.Default != nil:
+		return name, m.Default, nil
+	case !found && m.Default == nil:
+		return name, nil, fmt.Errorf("%s no handler with name: %s (%d)", m, name, len(name))
+	default:
+		return name, h, nil
+	}
+}
+
+// String returns the muxer's printing representation
+func (m *Mux) String() string {
+	m.RLock()
+	defer m.RUnlock()
+	return fmt.Sprintf("<Muxer %p %d>", m, len(m.Handlers))
+}
+
+// SetHandler sets the protocol handler on the Network's Muxer.
+// This operation is threadsafe.
+func (m *Mux) SetHandler(p inet.ProtocolID, h inet.StreamHandler) {
+	log.Debugf("%s setting handler for protocol: %s (%d)", m, p, len(p))
+	m.Lock()
+	m.Handlers[p] = h
+	m.Unlock()
+}
+
+// Handle reads the next name off the Stream, and calls a handler function
+// This is done in its own goroutine, to avoid blocking the caller.
+func (m *Mux) Handle(s inet.Stream) {
+	go m.HandleSync(s)
+}
+
+// HandleSync reads the next name off the Stream, and calls a handler function
+// This is done synchronously. The handler function will return before
+// HandleSync returns.
+func (m *Mux) HandleSync(s inet.Stream) {
+	ctx := context.Background()
+
+	name, handler, err := m.ReadProtocolHeader(s)
+	if err != nil {
+		err = fmt.Errorf("protocol mux error: %s", err)
+		log.Error(err)
+		log.Event(ctx, "muxError", lgbl.Error(err))
+		return
+	}
+
+	log.Infof("muxer handle protocol: %s", name)
+	log.Event(ctx, "muxHandle", eventlog.Metadata{"protocol": name})
+	handler(s)
+}
+
+// ReadLengthPrefix reads the name from Reader with a length-byte-prefix.
+func ReadLengthPrefix(r io.Reader) (string, error) {
+	// c-string identifier
+	// the first byte is our length
+	l := make([]byte, 1)
+	if _, err := io.ReadFull(r, l); err != nil {
+		return "", err
+	}
+	length := int(l[0])
+
+	// the next are our identifier
+	name := make([]byte, length)
+	if _, err := io.ReadFull(r, name); err != nil {
+		return "", err
+	}
+
+	return string(name), nil
+}
+
+// WriteLengthPrefix writes the name into Writer with a length-byte-prefix.
+func WriteLengthPrefix(w io.Writer, name string) error {
+	// log.Error("WriteLengthPrefix", name)
+	s := make([]byte, len(name)+1)
+	s[0] = byte(len(name))
+	copy(s[1:], []byte(name))
+
+	_, err := w.Write(s)
+	return err
+}
+
+// WriteProtocolHeader defines how a protocol is written into the header of
+// a stream. This is so the muxer can multiplex between services.
+func WriteProtocolHeader(pr inet.ProtocolID, s inet.Stream) error {
+	if pr != "" { // only write proper protocol headers
+		if err := WriteLengthPrefix(s, string(pr)); err != nil {
+			return err
+		}
+	}
+	return nil
+}

net/services/mux/mux_test.go

+package mux
+
+import (
+	"bytes"
+	"testing"
+
+	inet "github.com/jbenet/go-ipfs/p2p/net"
+)
+
+var testCases = map[string]string{
+	"bitswap": "\u0007bitswap",
+	"dht":     "\u0003dht",
+	"ipfs":    "\u0004ipfs",
+	"ipfsdksnafkasnfkdajfkdajfdsjadosiaaodjasofdias": ".ipfsdksnafkasnfkdajfkdajfdsjadosiaaodjasofdias",
+}
+
+func TestWrite(t *testing.T) {
+	for k, v := range testCases {
+		var buf bytes.Buffer
+		WriteLengthPrefix(&buf, k)
+
+		v2 := buf.Bytes()
+		if !bytes.Equal(v2, []byte(v)) {
+			t.Errorf("failed: %s - %v != %v", k, []byte(v), v2)
+		}
+	}
+}
+
+func TestHandler(t *testing.T) {
+
+	outs := make(chan string, 10)
+
+	h := func(n string) func(s inet.Stream) {
+		return func(s inet.Stream) {
+			outs <- n
+		}
+	}
+
+	m := Mux{Handlers: inet.StreamHandlerMap{}}
+	m.Default = h("default")
+	m.Handlers["dht"] = h("bitswap")
+	// m.Handlers["ipfs"] = h("bitswap") // default!
+	m.Handlers["bitswap"] = h("bitswap")
+	m.Handlers["ipfsdksnafkasnfkdajfkdajfdsjadosiaaodjasofdias"] = h("bitswap")
+
+	for k, v := range testCases {
+		var buf bytes.Buffer
+		if _, err := buf.Write([]byte(v)); err != nil {
+			t.Error(err)
+			continue
+		}
+
+		name, _, err := m.ReadProtocolHeader(&buf)
+		if err != nil {
+			t.Error(err)
+			continue
+		}
+
+		if name != k {
+			t.Errorf("name mismatch: %s != %s", k, name)
+			continue
+		}
+	}
+
+}

net/services/relay/relay.go

+package relay
+
+import (
+	"fmt"
+	"io"
+
+	context "github.com/jbenet/go-ipfs/Godeps/_workspace/src/code.google.com/p/go.net/context"
+	ctxgroup "github.com/jbenet/go-ipfs/Godeps/_workspace/src/github.com/jbenet/go-ctxgroup"
+	mh "github.com/jbenet/go-ipfs/Godeps/_workspace/src/github.com/jbenet/go-multihash"
+
+	inet "github.com/jbenet/go-ipfs/p2p/net"
+	peer "github.com/jbenet/go-ipfs/p2p/peer"
+	eventlog "github.com/jbenet/go-ipfs/util/eventlog"
+)
+
+var log = eventlog.Logger("relay")
+
+// ProtocolRelay is the ProtocolID of the Relay Service.
+const ProtocolRelay inet.ProtocolID = "/ipfs/relay"
+
+// Relay is a structure that implements ProtocolRelay.
+// It is a simple relay service which forwards traffic
+// between two directly connected peers.
+//
+// the protocol is very simple:
+//
+//   /ipfs/relay\n
+//   <multihash src id>
+//   <multihash dst id>
+//   <data stream>
+//
+type RelayService struct {
+	Network inet.Network
+	handler inet.StreamHandler // for streams sent to us locally.
+
+	cg ctxgroup.ContextGroup
+}
+
+func NewRelayService(ctx context.Context, n inet.Network, sh inet.StreamHandler) *RelayService {
+	s := &RelayService{
+		Network: n,
+		handler: sh,
+		cg:      ctxgroup.WithContext(ctx),
+	}
+	n.SetHandler(inet.ProtocolRelay, s.requestHandler)
+	return s
+}
+
+// requestHandler is the function called by clients
+func (rs *RelayService) requestHandler(s inet.Stream) {
+	if err := rs.handleStream(s); err != nil {
+		log.Error("RelayService error:", err)
+	}
+}
+
+// handleStream is our own handler, which returns an error for simplicity.
+func (rs *RelayService) handleStream(s inet.Stream) error {
+	defer s.Close()
+
+	// read the header (src and dst peer.IDs)
+	src, dst, err := ReadHeader(s)
+	if err != nil {
+		return fmt.Errorf("stream with bad header: %s", err)
+	}
+
+	local := rs.Network.LocalPeer()
+
+	switch {
+	case src == local:
+		return fmt.Errorf("relaying from self")
+	case dst == local: // it's for us! yaaay.
+		log.Debugf("%s consuming stream from %s", rs.Network.LocalPeer(), src)
+		return rs.consumeStream(s)
+	default: // src and dst are not local. relay it.
+		log.Debugf("%s relaying stream %s <--> %s", rs.Network.LocalPeer(), src, dst)
+		return rs.pipeStream(src, dst, s)
+	}
+}
+
+// consumeStream connects streams directed to the local peer
+// to our handler, with the header now stripped (read).
+func (rs *RelayService) consumeStream(s inet.Stream) error {
+	rs.handler(s) // boom.
+	return nil
+}
+
+// pipeStream relays over a stream to a remote peer. It's like `cat`
+func (rs *RelayService) pipeStream(src, dst peer.ID, s inet.Stream) error {
+	s2, err := rs.openStreamToPeer(dst)
+	if err != nil {
+		return fmt.Errorf("failed to open stream to peer: %s -- %s", dst, err)
+	}
+
+	if err := WriteHeader(s2, src, dst); err != nil {
+		return err
+	}
+
+	// connect the series of tubes.
+	done := make(chan retio, 2)
+	go func() {
+		n, err := io.Copy(s2, s)
+		done <- retio{n, err}
+	}()
+	go func() {
+		n, err := io.Copy(s, s2)
+		done <- retio{n, err}
+	}()
+
+	r1 := <-done
+	r2 := <-done
+	log.Infof("relayed %d/%d bytes between %s and %s", r1.n, r2.n, src, dst)
+
+	if r1.err != nil {
+		return r1.err
+	}
+	return r2.err
+}
+
+// openStreamToPeer opens a pipe to a remote endpoint
+// for now, can only open streams to directly connected peers.
+// maybe we can do some routing later on.
+func (rs *RelayService) openStreamToPeer(p peer.ID) (inet.Stream, error) {
+	return rs.Network.NewStream(ProtocolRelay, p)
+}
+
+func ReadHeader(r io.Reader) (src, dst peer.ID, err error) {
+
+	mhr := mh.NewReader(r)
+
+	s, err := mhr.ReadMultihash()
+	if err != nil {
+		return "", "", err
+	}
+
+	d, err := mhr.ReadMultihash()
+	if err != nil {
+		return "", "", err
+	}
+
+	return peer.ID(s), peer.ID(d), nil
+}
+
+func WriteHeader(w io.Writer, src, dst peer.ID) error {
+	// write header to w.
+	mhw := mh.NewWriter(w)
+	if err := mhw.WriteMultihash(mh.Multihash(src)); err != nil {
+		return fmt.Errorf("failed to write relay header: %s -- %s", dst, err)
+	}
+	if err := mhw.WriteMultihash(mh.Multihash(dst)); err != nil {
+		return fmt.Errorf("failed to write relay header: %s -- %s", dst, err)
+	}
+
+	return nil
+}
+
+type retio struct {
+	n   int64
+	err error
+}

net/services/relay/relay_test.go

+package relay_test
+
+import (
+	"io"
+	"testing"
+
+	inet "github.com/jbenet/go-ipfs/p2p/net"
+	mux "github.com/jbenet/go-ipfs/p2p/net/services/mux"
+	relay "github.com/jbenet/go-ipfs/p2p/net/services/relay"
+	netutil "github.com/jbenet/go-ipfs/p2p/net/swarmnet/util"
+	eventlog "github.com/jbenet/go-ipfs/util/eventlog"
+
+	context "github.com/jbenet/go-ipfs/Godeps/_workspace/src/code.google.com/p/go.net/context"
+)
+
+var log = eventlog.Logger("relay_test")
+
+func TestRelaySimple(t *testing.T) {
+
+	ctx := context.Background()
+
+	// these networks have the relay service wired in already.
+	n1 := netutil.GenNetwork(t, ctx)
+	n2 := netutil.GenNetwork(t, ctx)
+	n3 := netutil.GenNetwork(t, ctx)
+
+	n1p := n1.LocalPeer()
+	n2p := n2.LocalPeer()
+	n3p := n3.LocalPeer()
+
+	netutil.DivulgeAddresses(n2, n1)
+	netutil.DivulgeAddresses(n2, n3)
+
+	if err := n1.DialPeer(ctx, n2p); err != nil {
+		t.Fatalf("Failed to dial:", err)
+	}
+	if err := n3.DialPeer(ctx, n2p); err != nil {
+		t.Fatalf("Failed to dial:", err)
+	}
+
+	// setup handler on n3 to copy everything over to the pipe.
+	piper, pipew := io.Pipe()
+	n3.SetHandler(inet.ProtocolTesting, func(s inet.Stream) {
+		log.Debug("relay stream opened to n3!")
+		log.Debug("piping and echoing everything")
+		w := io.MultiWriter(s, pipew)
+		io.Copy(w, s)
+		log.Debug("closing stream")
+		s.Close()
+	})
+
+	// ok, now we can try to relay n1--->n2--->n3.
+	log.Debug("open relay stream")
+	s, err := n1.NewStream(relay.ProtocolRelay, n2p)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	// ok first thing we write the relay header n1->n3
+	log.Debug("write relay header")
+	if err := relay.WriteHeader(s, n1p, n3p); err != nil {
+		t.Fatal(err)
+	}
+
+	// ok now the header's there, we can write the next protocol header.
+	log.Debug("write testing header")
+	if err := mux.WriteProtocolHeader(inet.ProtocolTesting, s); err != nil {
+		t.Fatal(err)
+	}
+
+	// okay, now we should be able to write text, and read it out.
+	buf1 := []byte("abcdefghij")
+	buf2 := make([]byte, 10)
+	buf3 := make([]byte, 10)
+	log.Debug("write in some text.")
+	if _, err := s.Write(buf1); err != nil {
+		t.Fatal(err)
+	}
+
+	// read it out from the pipe.
+	log.Debug("read it out from the pipe.")
+	if _, err := io.ReadFull(piper, buf2); err != nil {
+		t.Fatal(err)
+	}
+	if string(buf1) != string(buf2) {
+		t.Fatal("should've gotten that text out of the pipe")
+	}
+
+	// read it out from the stream (echoed)
+	log.Debug("read it out from the stream (echoed).")
+	if _, err := io.ReadFull(s, buf3); err != nil {
+		t.Fatal(err)
+	}
+	if string(buf1) != string(buf3) {
+		t.Fatal("should've gotten that text out of the stream")
+	}
+
+	// sweet. relay works.
+	log.Debug("sweet, relay works.")
+	s.Close()
+}
+
+func TestRelayAcrossFour(t *testing.T) {
+
+	ctx := context.Background()
+
+	// these networks have the relay service wired in already.
+	n1 := netutil.GenNetwork(t, ctx)
+	n2 := netutil.GenNetwork(t, ctx)
+	n3 := netutil.GenNetwork(t, ctx)
+	n4 := netutil.GenNetwork(t, ctx)
+	n5 := netutil.GenNetwork(t, ctx)
+
+	n1p := n1.LocalPeer()
+	n2p := n2.LocalPeer()
+	n3p := n3.LocalPeer()
+	n4p := n4.LocalPeer()
+	n5p := n5.LocalPeer()
+
+	netutil.DivulgeAddresses(n2, n1)
+	netutil.DivulgeAddresses(n2, n3)
+	netutil.DivulgeAddresses(n4, n3)
+	netutil.DivulgeAddresses(n4, n5)
+
+	if err := n1.DialPeer(ctx, n2p); err != nil {
+		t.Fatalf("Failed to dial:", err)
+	}
+	if err := n3.DialPeer(ctx, n2p); err != nil {
+		t.Fatalf("Failed to dial:", err)
+	}
+	if err := n3.DialPeer(ctx, n4p); err != nil {
+		t.Fatalf("Failed to dial:", err)
+	}
+	if err := n5.DialPeer(ctx, n4p); err != nil {
+		t.Fatalf("Failed to dial:", err)
+	}
+
+	// setup handler on n5 to copy everything over to the pipe.
+	piper, pipew := io.Pipe()
+	n5.SetHandler(inet.ProtocolTesting, func(s inet.Stream) {
+		log.Debug("relay stream opened to n5!")
+		log.Debug("piping and echoing everything")
+		w := io.MultiWriter(s, pipew)
+		io.Copy(w, s)
+		log.Debug("closing stream")
+		s.Close()
+	})
+
+	// ok, now we can try to relay n1--->n2--->n3--->n4--->n5
+	log.Debug("open relay stream")
+	s, err := n1.NewStream(relay.ProtocolRelay, n2p)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	log.Debugf("write relay header n1->n3 (%s -> %s)", n1p, n3p)
+	if err := relay.WriteHeader(s, n1p, n3p); err != nil {
+		t.Fatal(err)
+	}
+
+	log.Debugf("write relay header n1->n4 (%s -> %s)", n1p, n4p)
+	if err := mux.WriteProtocolHeader(relay.ProtocolRelay, s); err != nil {
+		t.Fatal(err)
+	}
+	if err := relay.WriteHeader(s, n1p, n4p); err != nil {
+		t.Fatal(err)
+	}
+
+	log.Debugf("write relay header n1->n5 (%s -> %s)", n1p, n5p)
+	if err := mux.WriteProtocolHeader(relay.ProtocolRelay, s); err != nil {
+		t.Fatal(err)
+	}
+	if err := relay.WriteHeader(s, n1p, n5p); err != nil {
+		t.Fatal(err)
+	}
+
+	// ok now the header's there, we can write the next protocol header.
+	log.Debug("write testing header")
+	if err := mux.WriteProtocolHeader(inet.ProtocolTesting, s); err != nil {
+		t.Fatal(err)
+	}
+
+	// okay, now we should be able to write text, and read it out.
+	buf1 := []byte("abcdefghij")
+	buf2 := make([]byte, 10)
+	buf3 := make([]byte, 10)
+	log.Debug("write in some text.")
+	if _, err := s.Write(buf1); err != nil {
+		t.Fatal(err)
+	}
+
+	// read it out from the pipe.
+	log.Debug("read it out from the pipe.")
+	if _, err := io.ReadFull(piper, buf2); err != nil {
+		t.Fatal(err)
+	}
+	if string(buf1) != string(buf2) {
+		t.Fatal("should've gotten that text out of the pipe")
+	}
+
+	// read it out from the stream (echoed)
+	log.Debug("read it out from the stream (echoed).")
+	if _, err := io.ReadFull(s, buf3); err != nil {
+		t.Fatal(err)
+	}
+	if string(buf1) != string(buf3) {
+		t.Fatal("should've gotten that text out of the stream")
+	}
+
+	// sweet. relay works.
+	log.Debug("sweet, relaying across 4 works.")
+	s.Close()
+}
+
+func TestRelayStress(t *testing.T) {
+	buflen := 1 << 18
+	iterations := 10
+
+	ctx := context.Background()
+
+	// these networks have the relay service wired in already.
+	n1 := netutil.GenNetwork(t, ctx)
+	n2 := netutil.GenNetwork(t, ctx)
+	n3 := netutil.GenNetwork(t, ctx)
+
+	n1p := n1.LocalPeer()
+	n2p := n2.LocalPeer()
+	n3p := n3.LocalPeer()
+
+	netutil.DivulgeAddresses(n2, n1)
+	netutil.DivulgeAddresses(n2, n3)
+
+	if err := n1.DialPeer(ctx, n2p); err != nil {
+		t.Fatalf("Failed to dial:", err)
+	}
+	if err := n3.DialPeer(ctx, n2p); err != nil {
+		t.Fatalf("Failed to dial:", err)
+	}
+
+	// setup handler on n3 to copy everything over to the pipe.
+	piper, pipew := io.Pipe()
+	n3.SetHandler(inet.ProtocolTesting, func(s inet.Stream) {
+		log.Debug("relay stream opened to n3!")
+		log.Debug("piping and echoing everything")
+		w := io.MultiWriter(s, pipew)
+		io.Copy(w, s)
+		log.Debug("closing stream")
+		s.Close()
+	})
+
+	// ok, now we can try to relay n1--->n2--->n3.
+	log.Debug("open relay stream")
+	s, err := n1.NewStream(relay.ProtocolRelay, n2p)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	// ok first thing we write the relay header n1->n3
+	log.Debug("write relay header")
+	if err := relay.WriteHeader(s, n1p, n3p); err != nil {
+		t.Fatal(err)
+	}
+
+	// ok now the header's there, we can write the next protocol header.
+	log.Debug("write testing header")
+	if err := mux.WriteProtocolHeader(inet.ProtocolTesting, s); err != nil {
+		t.Fatal(err)
+	}
+
+	// okay, now write lots of text and read it back out from both
+	// the pipe and the stream.
+	buf1 := make([]byte, buflen)
+	buf2 := make([]byte, len(buf1))
+	buf3 := make([]byte, len(buf1))
+
+	fillbuf := func(buf []byte, b byte) {
+		for i := range buf {
+			buf[i] = b
+		}
+	}
+
+	for i := 0; i < iterations; i++ {
+		fillbuf(buf1, byte(int('a')+i))
+		log.Debugf("writing %d bytes (%d/%d)", len(buf1), i, iterations)
+		if _, err := s.Write(buf1); err != nil {
+			t.Fatal(err)
+		}
+
+		log.Debug("read it out from the pipe.")
+		if _, err := io.ReadFull(piper, buf2); err != nil {
+			t.Fatal(err)
+		}
+		if string(buf1) != string(buf2) {
+			t.Fatal("should've gotten that text out of the pipe")
+		}
+
+		// read it out from the stream (echoed)
+		log.Debug("read it out from the stream (echoed).")
+		if _, err := io.ReadFull(s, buf3); err != nil {
+			t.Fatal(err)
+		}
+		if string(buf1) != string(buf3) {
+			t.Fatal("should've gotten that text out of the stream")
+		}
+	}
+
+	log.Debug("sweet, relay works under stress.")
+	s.Close()
+}

net/swarm/addr.go

+package swarm
+
+import (
+	conn "github.com/jbenet/go-ipfs/p2p/net/conn"
+	eventlog "github.com/jbenet/go-ipfs/util/eventlog"
+
+	context "github.com/jbenet/go-ipfs/Godeps/_workspace/src/code.google.com/p/go.net/context"
+	ma "github.com/jbenet/go-ipfs/Godeps/_workspace/src/github.com/jbenet/go-multiaddr"
+	manet "github.com/jbenet/go-ipfs/Godeps/_workspace/src/github.com/jbenet/go-multiaddr-net"
+)
+
+// ListenAddresses returns a list of addresses at which this swarm listens.
+func (s *Swarm) ListenAddresses() []ma.Multiaddr {
+	listeners := s.swarm.Listeners()
+	addrs := make([]ma.Multiaddr, 0, len(listeners))
+	for _, l := range listeners {
+		if l2, ok := l.NetListener().(conn.Listener); ok {
+			addrs = append(addrs, l2.Multiaddr())
+		}
+	}
+	return addrs
+}
+
+// InterfaceListenAddresses returns a list of addresses at which this swarm
+// listens. It expands "any interface" addresses (/ip4/0.0.0.0, /ip6/::) to
+// use the known local interfaces.
+func InterfaceListenAddresses(s *Swarm) ([]ma.Multiaddr, error) {
+	return resolveUnspecifiedAddresses(s.ListenAddresses())
+}
+
+// resolveUnspecifiedAddresses expands unspecified ip addresses (/ip4/0.0.0.0, /ip6/::) to
+// use the known local interfaces.
+func resolveUnspecifiedAddresses(unspecifiedAddrs []ma.Multiaddr) ([]ma.Multiaddr, error) {
+	var outputAddrs []ma.Multiaddr
+
+	// todo optimize: only fetch these if we have a "any" addr.
+	ifaceAddrs, err := interfaceAddresses()
+	if err != nil {
+		return nil, err
+	}
+
+	for _, a := range unspecifiedAddrs {
+
+		// split address into its components
+		split := ma.Split(a)
+
+		// if first component (ip) is not unspecified, use it as is.
+		if !manet.IsIPUnspecified(split[0]) {
+			outputAddrs = append(outputAddrs, a)
+			continue
+		}
+
+		// unspecified? add one address per interface.
+		for _, ia := range ifaceAddrs {
+			split[0] = ia
+			joined := ma.Join(split...)
+			outputAddrs = append(outputAddrs, joined)
+		}
+	}
+
+	log.Event(context.TODO(), "interfaceListenAddresses", func() eventlog.Loggable {
+		var addrs []string
+		for _, addr := range outputAddrs {
+			addrs = append(addrs, addr.String())
+		}
+		return eventlog.Metadata{"addresses": addrs}
+	}())
+	log.Debug("InterfaceListenAddresses:", outputAddrs)
+	return outputAddrs, nil
+}
+
+// interfaceAddresses returns a list of addresses associated with local machine
+func interfaceAddresses() ([]ma.Multiaddr, error) {
+	maddrs, err := manet.InterfaceMultiaddrs()
+	if err != nil {
+		return nil, err
+	}
+
+	var nonLoopback []ma.Multiaddr
+	for _, a := range maddrs {
+		if !manet.IsIPLoopback(a) {
+			nonLoopback = append(nonLoopback, a)
+		}
+	}
+
+	return nonLoopback, nil
+}
+
+// addrInList returns whether or not an address is part of a list.
+// this is useful to check if NAT is happening (or other bugs?)
+func addrInList(addr ma.Multiaddr, list []ma.Multiaddr) bool {
+	for _, addr2 := range list {
+		if addr.Equal(addr2) {
+			return true
+		}
+	}
+	return false
+}
+
+// checkNATWarning checks if our observed addresses differ. if so,
+// informs the user that certain things might not work yet
+func checkNATWarning(s *Swarm, observed ma.Multiaddr, expected ma.Multiaddr) {
+	if observed.Equal(expected) {
+		return
+	}
+
+	listen, err := InterfaceListenAddresses(s)
+	if err != nil {
+		log.Errorf("Error retrieving swarm.InterfaceListenAddresses: %s", err)
+		return
+	}
+
+	if !addrInList(observed, listen) { // probably a nat
+		log.Warningf(natWarning, observed, listen)
+	}
+}
+
+const natWarning = `Remote peer observed our address to be: %s
+The local addresses are: %s
+Thus, connection is going through NAT, and other connections may fail.
+
+IPFS NAT traversal is still under development. Please bug us on github or irc to fix this.
+Baby steps: http://jbenet.static.s3.amazonaws.com/271dfcf/baby-steps.gif
+`

net/swarm/simul_test.go

+package swarm
+
+import (
+	"sync"
+	"testing"
+	"time"
+
+	peer "github.com/jbenet/go-ipfs/p2p/peer"
+
+	context "github.com/jbenet/go-ipfs/Godeps/_workspace/src/code.google.com/p/go.net/context"
+	ma "github.com/jbenet/go-ipfs/Godeps/_workspace/src/github.com/jbenet/go-multiaddr"
+)
+
+func TestSimultOpen(t *testing.T) {
+	// t.Skip("skipping for another test")
+
+	ctx := context.Background()
+	swarms, peers := makeSwarms(ctx, t, 2)
+
+	// connect everyone
+	{
+		var wg sync.WaitGroup
+		connect := func(s *Swarm, dst peer.ID, addr ma.Multiaddr) {
+			// copy for other peer
+			s.peers.AddAddress(dst, addr)
+			if _, err := s.Dial(ctx, dst); err != nil {
+				t.Fatal("error swarm dialing to peer", err)
+			}
+			wg.Done()
+		}
+
+		log.Info("Connecting swarms simultaneously.")
+		wg.Add(2)
+		go connect(swarms[0], swarms[1].local, peers[1].Addr)
+		go connect(swarms[1], swarms[0].local, peers[0].Addr)
+		wg.Wait()
+	}
+
+	for _, s := range swarms {
+		s.Close()
+	}
+}
+
+func TestSimultOpenMany(t *testing.T) {
+	// t.Skip("very very slow")
+
+	addrs := 20
+	SubtestSwarm(t, addrs, 10)
+}
+
+func TestSimultOpenFewStress(t *testing.T) {
+	if testing.Short() {
+		t.SkipNow()
+	}
+	// t.Skip("skipping for another test")
+
+	msgs := 40
+	swarms := 2
+	rounds := 10
+	// rounds := 100
+
+	for i := 0; i < rounds; i++ {
+		SubtestSwarm(t, swarms, msgs)
+		<-time.After(10 * time.Millisecond)
+	}
+}

net/swarm/swarm.go

+// package swarm implements a connection muxer with a pair of channels
+// to synchronize all network communication.
+package swarm
+
+import (
+	peer "github.com/jbenet/go-ipfs/p2p/peer"
+	eventlog "github.com/jbenet/go-ipfs/util/eventlog"
+
+	context "github.com/jbenet/go-ipfs/Godeps/_workspace/src/code.google.com/p/go.net/context"
+	ctxgroup "github.com/jbenet/go-ipfs/Godeps/_workspace/src/github.com/jbenet/go-ctxgroup"
+	ma "github.com/jbenet/go-ipfs/Godeps/_workspace/src/github.com/jbenet/go-multiaddr"
+	ps "github.com/jbenet/go-ipfs/Godeps/_workspace/src/github.com/jbenet/go-peerstream"
+	psy "github.com/jbenet/go-ipfs/Godeps/_workspace/src/github.com/jbenet/go-peerstream/transport/yamux"
+)
+
+var log = eventlog.Logger("swarm2")
+
+var PSTransport = psy.DefaultTransport
+
+// Swarm is a connection muxer, allowing connections to other peers to
+// be opened and closed, while still using the same Chan for all
+// communication. The Chan sends/receives Messages, which note the
+// destination or source Peer.
+//
+// Uses peerstream.Swarm
+type Swarm struct {
+	swarm *ps.Swarm
+	local peer.ID
+	peers peer.Peerstore
+	connh ConnHandler
+
+	cg ctxgroup.ContextGroup
+}
+
+// NewSwarm constructs a Swarm, with a Chan.
+func NewSwarm(ctx context.Context, listenAddrs []ma.Multiaddr,
+	local peer.ID, peers peer.Peerstore) (*Swarm, error) {
+
+	s := &Swarm{
+		swarm: ps.NewSwarm(PSTransport),
+		local: local,
+		peers: peers,
+		cg:    ctxgroup.WithContext(ctx),
+	}
+
+	// configure Swarm
+	s.cg.SetTeardown(s.teardown)
+	s.SetConnHandler(nil) // make sure to setup our own conn handler.
+
+	return s, s.listen(listenAddrs)
+}
+
+func (s *Swarm) teardown() error {
+	return s.swarm.Close()
+}
+
+// CtxGroup returns the Context Group of the swarm
+func (s *Swarm) CtxGroup() ctxgroup.ContextGroup {
+	return s.cg
+}
+
+// Close stops the Swarm.
+func (s *Swarm) Close() error {
+	return s.cg.Close()
+}
+
+// StreamSwarm returns the underlying peerstream.Swarm
+func (s *Swarm) StreamSwarm() *ps.Swarm {
+	return s.swarm
+}
+
+// SetConnHandler assigns the handler for new connections.
+// See peerstream. You will rarely use this. See SetStreamHandler
+func (s *Swarm) SetConnHandler(handler ConnHandler) {
+
+	// handler is nil if user wants to clear the old handler.
+	if handler == nil {
+		s.swarm.SetConnHandler(func(psconn *ps.Conn) {
+			s.connHandler(psconn)
+		})
+		return
+	}
+
+	s.swarm.SetConnHandler(func(psconn *ps.Conn) {
+		// sc is nil if closed in our handler.
+		if sc := s.connHandler(psconn); sc != nil {
+			// call the user's handler. in a goroutine for sync safety.
+			go handler(sc)
+		}
+	})
+}
+
+// SetStreamHandler assigns the handler for new streams.
+// See peerstream.
+func (s *Swarm) SetStreamHandler(handler StreamHandler) {
+	s.swarm.SetStreamHandler(func(s *ps.Stream) {
+		handler(wrapStream(s))
+	})
+}
+
+// NewStreamWithPeer creates a new stream on any available connection to p
+func (s *Swarm) NewStreamWithPeer(p peer.ID) (*Stream, error) {
+	// if we have no connections, try connecting.
+	if len(s.ConnectionsToPeer(p)) == 0 {
+		log.Debug("Swarm: NewStreamWithPeer no connections. Attempting to connect...")
+		if _, err := s.Dial(context.Background(), p); err != nil {
+			return nil, err
+		}
+	}
+	log.Debug("Swarm: NewStreamWithPeer...")
+
+	st, err := s.swarm.NewStreamWithGroup(p)
+	return wrapStream(st), err
+}
+
+// StreamsWithPeer returns all the live Streams to p
+func (s *Swarm) StreamsWithPeer(p peer.ID) []*Stream {
+	return wrapStreams(ps.StreamsWithGroup(p, s.swarm.Streams()))
+}
+
+// ConnectionsToPeer returns all the live connections to p
+func (s *Swarm) ConnectionsToPeer(p peer.ID) []*Conn {
+	return wrapConns(ps.ConnsWithGroup(p, s.swarm.Conns()))
+}
+
+// Connections returns a slice of all connections.
+func (s *Swarm) Connections() []*Conn {
+	return wrapConns(s.swarm.Conns())
+}
+
+// CloseConnection removes a given peer from swarm + closes the connection
+func (s *Swarm) CloseConnection(p peer.ID) error {
+	conns := s.swarm.ConnsWithGroup(p) // boom.
+	for _, c := range conns {
+		c.Close()
+	}
+	return nil
+}
+
+// Peers returns a copy of the set of peers swarm is connected to.
+func (s *Swarm) Peers() []peer.ID {
+	conns := s.Connections()
+
+	seen := make(map[peer.ID]struct{})
+	peers := make([]peer.ID, 0, len(conns))
+	for _, c := range conns {
+		p := c.RemotePeer()
+		if _, found := seen[p]; found {
+			continue
+		}
+
+		peers = append(peers, p)
+	}
+	return peers
+}
+
+// LocalPeer returns the local peer swarm is associated to.
+func (s *Swarm) LocalPeer() peer.ID {
+	return s.local
+}