p2p/net/swarm: do not usre link local addrs

net/conn/dial.go

@@ -22,7 +22,7 @@ func (d *Dialer) String() string {
 // Example: d.DialAddr(ctx, peer.Addresses()[0], peer)
 func (d *Dialer) Dial(ctx context.Context, raddr ma.Multiaddr, remote peer.ID) (Conn, error) {
 
-	network, _, err := manet.DialArgs(raddr)
+	_, _, err := manet.DialArgs(raddr)
 	if err != nil {
 		return nil, err
 	}
@@ -31,17 +31,20 @@ func (d *Dialer) Dial(ctx context.Context, raddr ma.Multiaddr, remote peer.ID) (
 		return nil, debugerror.Errorf("Attempted to connect to zero address: %s", raddr)
 	}
 
-	var laddr ma.Multiaddr
 	if len(d.LocalAddrs) > 0 {
-		// laddr := MultiaddrNetMatch(raddr, d.LocalAddrs)
+		laddrs := manet.AddrMatch(raddr, d.LocalAddrs)
-		laddr = NetAddress(network, d.LocalAddrs)
+		if len(laddrs) < 1 {
-		if laddr == nil {
+			return nil, debugerror.Errorf("No local address matches %s %s", raddr, d.LocalAddrs)
-			return nil, debugerror.Errorf("No local address for network %s", network)
 		}
-	}
 
-	// TODO: try to get reusing addr/ports to work.
+		// TODO pick with a good heuristic
-	// d.Dialer.LocalAddr = laddr
+		// we use a random one for now to prevent bad addresses from making nodes unreachable
+		// with a random selection, multiple tries may work.
+		// laddr := laddrs[rand.Intn(len(laddrs))]
+
+		// TODO: try to get reusing addr/ports to work.
+		// d.Dialer.LocalAddr = laddr
+	}
 
 	log.Debugf("%s dialing %s %s", d.LocalPeer, remote, raddr)
 	maconn, err := d.Dialer.Dial(raddr)
@@ -116,15 +119,3 @@ func MultiaddrNetMatch(tgt ma.Multiaddr, srcs []ma.Multiaddr) ma.Multiaddr {
 	}
 	return nil
 }
-
-// NetAddress returns the first Multiaddr found for a given network.
-func NetAddress(n string, addrs []ma.Multiaddr) ma.Multiaddr {
-	for _, a := range addrs {
-		for _, p := range a.Protocols() {
-			if p.Name == n {
-				return a
-			}
-		}
-	}
-	return nil
-}

net/conn/listen.go

@@ -102,11 +102,7 @@ func (l *listener) Addr() net.Addr {
 // If there is an error converting from net.Addr to ma.Multiaddr,
 // the return value will be nil.
 func (l *listener) Multiaddr() ma.Multiaddr {
-	maddr, err := manet.FromNetAddr(l.Addr())
+	return l.Listener.Multiaddr()
-	if err != nil {
-		return nil // error
-	}
-	return maddr
 }
 
 // LocalPeer is the identity of the local Peer.
@@ -140,7 +136,7 @@ func Listen(ctx context.Context, addr ma.Multiaddr, local peer.ID, sk ic.PrivKey
 	}
 	l.cg.SetTeardown(l.teardown)
 
-	log.Infof("swarm listening on %s", l.Multiaddr())
+	log.Debugf("Conn Listener on %s", l.Multiaddr())
 	log.Event(ctx, "swarmListen", l)
 	return l, nil
 }

net/swarm/addr.go

@@ -1,193 +0,0 @@
-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"
-)
-
-// SupportedTransportStrings is the list of supported transports for the swarm.
-// These are strings of encapsulated multiaddr protocols. E.g.:
-//   /ip4/tcp
-var SupportedTransportStrings = []string{
-	"/ip4/tcp",
-	"/ip6/tcp",
-	// "/ip4/udp/utp", disabled because the lib is broken
-	// "/ip6/udp/utp", disabled because the lib is broken
-	// "/ip4/udp/udt", disabled because the lib doesnt work on arm
-	// "/ip6/udp/udt", disabled because the lib doesnt work on arm
-}
-
-// SupportedTransportProtocols is the list of supported transports for the swarm.
-// These are []ma.Protocol lists. Populated at runtime from SupportedTransportStrings
-var SupportedTransportProtocols = [][]ma.Protocol{}
-
-func init() {
-	// initialize SupportedTransportProtocols
-	transports := make([][]ma.Protocol, len(SupportedTransportStrings))
-	for _, s := range SupportedTransportStrings {
-		t, err := ma.ProtocolsWithString(s)
-		if err != nil {
-			panic(err) // important to fix this in the codebase
-		}
-		transports = append(transports, t)
-	}
-	SupportedTransportProtocols = transports
-}
-
-// FilterAddrs is a filter that removes certain addresses
-// from a list. the addresses removed are those known NOT
-// to work with swarm. Namely, addresses with UTP.
-func FilterAddrs(a []ma.Multiaddr) []ma.Multiaddr {
-	b := make([]ma.Multiaddr, 0, len(a))
-	for _, addr := range a {
-		if AddrUsable(addr) {
-			b = append(b, addr)
-		}
-	}
-	return b
-}
-
-// AddrUsable returns whether the swarm can use this addr.
-func AddrUsable(a ma.Multiaddr) bool {
-	// test the address protocol list is in SupportedTransportProtocols
-
-	matches := func(a, b []ma.Protocol) bool {
-		if len(a) != len(b) {
-			return false
-		}
-
-		for i := range a {
-			if a[i].Code != b[i].Code {
-				return false
-			}
-		}
-		return true
-	}
-
-	transport := a.Protocols()
-	for _, supported := range SupportedTransportProtocols {
-		if matches(supported, transport) {
-			return true
-		}
-	}
-
-	return false
-}
-
-// 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/addr/addr.go

@@ -0,0 +1,258 @@
+package addrutil
+
+import (
+	"fmt"
+
+	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"
+)
+
+var log = eventlog.Logger("p2p/net/swarm/addr")
+
+// SupportedTransportStrings is the list of supported transports for the swarm.
+// These are strings of encapsulated multiaddr protocols. E.g.:
+//   /ip4/tcp
+var SupportedTransportStrings = []string{
+	"/ip4/tcp",
+	"/ip6/tcp",
+	// "/ip4/udp/utp", disabled because the lib is broken
+	// "/ip6/udp/utp", disabled because the lib is broken
+	// "/ip4/udp/udt", disabled because the lib doesnt work on arm
+	// "/ip6/udp/udt", disabled because the lib doesnt work on arm
+}
+
+// SupportedTransportProtocols is the list of supported transports for the swarm.
+// These are []ma.Protocol lists. Populated at runtime from SupportedTransportStrings
+var SupportedTransportProtocols = [][]ma.Protocol{}
+
+func init() {
+	// initialize SupportedTransportProtocols
+	transports := make([][]ma.Protocol, len(SupportedTransportStrings))
+	for _, s := range SupportedTransportStrings {
+		t, err := ma.ProtocolsWithString(s)
+		if err != nil {
+			panic(err) // important to fix this in the codebase
+		}
+		transports = append(transports, t)
+	}
+	SupportedTransportProtocols = transports
+}
+
+// FilterAddrs is a filter that removes certain addresses
+// from a list. the addresses removed are those known NOT
+// to work with our network. Namely, addresses with UTP.
+func FilterAddrs(a []ma.Multiaddr) []ma.Multiaddr {
+	b := make([]ma.Multiaddr, 0, len(a))
+	for _, addr := range a {
+		if AddrUsable(addr, false) {
+			b = append(b, addr)
+		}
+	}
+	return b
+}
+
+// AddrOverNonLocalIP returns whether the addr uses a non-local ip link
+func AddrOverNonLocalIP(a ma.Multiaddr) bool {
+	split := ma.Split(a)
+	if len(split) < 1 {
+		return false
+	}
+	if manet.IsIP6LinkLocal(split[0]) {
+		return false
+	}
+	return true
+}
+
+// AddrUsable returns whether our network can use this addr.
+// We only use the transports in SupportedTransportStrings,
+// and we do not link local addresses. Loopback is ok
+// as we need to be able to connect to multiple ipfs nodes
+// in the same machine.
+func AddrUsable(a ma.Multiaddr, partial bool) bool {
+
+	if !AddrOverNonLocalIP(a) {
+		return false
+	}
+
+	// test the address protocol list is in SupportedTransportProtocols
+	matches := func(supported, test []ma.Protocol) bool {
+		if len(test) > len(supported) {
+			return false
+		}
+
+		// when partial, it's ok if test < supported.
+		if !partial && len(supported) != len(test) {
+			return false
+		}
+
+		for i := range test {
+			if supported[i].Code != test[i].Code {
+				return false
+			}
+		}
+		return true
+	}
+
+	transport := a.Protocols()
+	for _, supported := range SupportedTransportProtocols {
+		if matches(supported, transport) {
+			return true
+		}
+	}
+
+	return false
+}
+
+// ResolveUnspecifiedAddress expands an unspecified ip addresses (/ip4/0.0.0.0, /ip6/::) to
+// use the known local interfaces. If ifaceAddr is nil, we request interface addresses
+// from the network stack. (this is so you can provide a cached value if resolving many addrs)
+func ResolveUnspecifiedAddress(resolve ma.Multiaddr, ifaceAddrs []ma.Multiaddr) ([]ma.Multiaddr, error) {
+	// split address into its components
+	split := ma.Split(resolve)
+
+	// if first component (ip) is not unspecified, use it as is.
+	if !manet.IsIPUnspecified(split[0]) {
+		return []ma.Multiaddr{resolve}, nil
+	}
+
+	out := make([]ma.Multiaddr, 0, len(ifaceAddrs))
+	for _, ia := range ifaceAddrs {
+		// must match the first protocol to be resolve.
+		if ia.Protocols()[0].Code != resolve.Protocols()[0].Code {
+			continue
+		}
+
+		split[0] = ia
+		joined := ma.Join(split...)
+		out = append(out, joined)
+		log.Debug("adding resolved addr:", resolve, joined, out)
+	}
+	if len(out) < 1 {
+		return nil, fmt.Errorf("failed to resolve: %s", resolve)
+	}
+	return out, nil
+}
+
+// ResolveUnspecifiedAddresses expands unspecified ip addresses (/ip4/0.0.0.0, /ip6/::) to
+// use the known local interfaces.
+func ResolveUnspecifiedAddresses(unspecAddrs, ifaceAddrs []ma.Multiaddr) ([]ma.Multiaddr, error) {
+
+	// todo optimize: only fetch these if we have a "any" addr.
+	if len(ifaceAddrs) < 1 {
+		var err error
+		ifaceAddrs, err = InterfaceAddresses()
+		if err != nil {
+			return nil, err
+		}
+		// log.Debug("InterfaceAddresses:", ifaceAddrs)
+	}
+
+	var outputAddrs []ma.Multiaddr
+	for _, a := range unspecAddrs {
+		// unspecified?
+		resolved, err := ResolveUnspecifiedAddress(a, ifaceAddrs)
+		if err != nil {
+			continue // optimistic. if we cant resolve anything, we'll know at the bottom.
+		}
+		// log.Debug("resolved:", a, resolved)
+		outputAddrs = append(outputAddrs, resolved...)
+	}
+
+	if len(outputAddrs) < 1 {
+		return nil, fmt.Errorf("failed to specify addrs: %s", unspecAddrs)
+	}
+
+	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("ResolveUnspecifiedAddresses:", unspecAddrs, ifaceAddrs, outputAddrs)
+	return outputAddrs, nil
+}
+
+// InterfaceAddresses returns a list of addresses associated with local machine
+// Note: we do not return link local addresses. IP loopback is ok, because we
+// may be connecting to other nodes in the same machine.
+func InterfaceAddresses() ([]ma.Multiaddr, error) {
+	maddrs, err := manet.InterfaceMultiaddrs()
+	if err != nil {
+		return nil, err
+	}
+	log.Debug("InterfaceAddresses: from manet:", maddrs)
+
+	var out []ma.Multiaddr
+	for _, a := range maddrs {
+		if !AddrUsable(a, true) { // partial
+			// log.Debug("InterfaceAddresses: skipping unusable:", a)
+			continue
+		}
+
+		out = append(out, a)
+	}
+
+	log.Debug("InterfaceAddresses: usable:", out)
+	return out, 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
+}
+
+// AddrIsShareableOnWAN returns whether the given address should be shareable on the
+// wide area network (wide internet).
+func AddrIsShareableOnWAN(addr ma.Multiaddr) bool {
+	s := ma.Split(addr)
+	if len(s) < 1 {
+		return false
+	}
+	a := s[0]
+	if manet.IsIPLoopback(a) || manet.IsIP6LinkLocal(a) || manet.IsIPUnspecified(a) {
+		return false
+	}
+	return manet.IsThinWaist(a)
+}
+
+// WANShareableAddrs filters addresses based on whether they're shareable on WAN
+func WANShareableAddrs(inp []ma.Multiaddr) []ma.Multiaddr {
+	out := make([]ma.Multiaddr, 0, len(inp))
+	for _, a := range inp {
+		if AddrIsShareableOnWAN(a) {
+			out = append(out, a)
+		}
+	}
+	return out
+}
+
+// CheckNATWarning checks if our observed addresses differ. if so,
+// informs the user that certain things might not work yet
+func CheckNATWarning(observed, expected ma.Multiaddr, listen []ma.Multiaddr) {
+	if observed.Equal(expected) {
+		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/addr/addr_test.go

@@ -0,0 +1,198 @@
+package addrutil
+
+import (
+	"testing"
+
+	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"
+)
+
+func newMultiaddr(t *testing.T, s string) ma.Multiaddr {
+	maddr, err := ma.NewMultiaddr(s)
+	if err != nil {
+		t.Fatal(err)
+	}
+	return maddr
+}
+
+func TestFilterAddrs(t *testing.T) {
+
+	bad := []ma.Multiaddr{
+		newMultiaddr(t, "/ip4/1.2.3.4/udp/1234"),           // unreliable
+		newMultiaddr(t, "/ip4/1.2.3.4/udp/1234/sctp/1234"), // not in manet
+		newMultiaddr(t, "/ip4/1.2.3.4/udp/1234/utp"),       // utp is broken
+		newMultiaddr(t, "/ip4/1.2.3.4/udp/1234/udt"),       // udt is broken on arm
+		newMultiaddr(t, "/ip6/fe80::1/tcp/1234"),           // link local
+		newMultiaddr(t, "/ip6/fe80::100/tcp/1234"),         // link local
+	}
+
+	good := []ma.Multiaddr{
+		newMultiaddr(t, "/ip4/127.0.0.1/tcp/1234"),
+		newMultiaddr(t, "/ip6/::1/tcp/1234"),
+	}
+
+	goodAndBad := append(good, bad...)
+
+	// test filters
+
+	for _, a := range bad {
+		if AddrUsable(a, false) {
+			t.Errorf("addr %s should be unusable", a)
+		}
+		if AddrUsable(a, true) {
+			t.Errorf("addr %s should be unusable", a)
+		}
+	}
+
+	for _, a := range good {
+		if !AddrUsable(a, false) {
+			t.Errorf("addr %s should be usable", a)
+		}
+		if !AddrUsable(a, true) {
+			t.Errorf("addr %s should be usable", a)
+		}
+	}
+
+	subtestAddrsEqual(t, FilterAddrs(bad), []ma.Multiaddr{})
+	subtestAddrsEqual(t, FilterAddrs(good), good)
+	subtestAddrsEqual(t, FilterAddrs(goodAndBad), good)
+}
+
+func subtestAddrsEqual(t *testing.T, a, b []ma.Multiaddr) {
+	if len(a) != len(b) {
+		t.Error(t)
+	}
+
+	in := func(addr ma.Multiaddr, l []ma.Multiaddr) bool {
+		for _, addr2 := range l {
+			if addr.Equal(addr2) {
+				return true
+			}
+		}
+		return false
+	}
+
+	for _, aa := range a {
+		if !in(aa, b) {
+			t.Errorf("%s not in %s", aa, b)
+		}
+	}
+}
+
+func TestInterfaceAddrs(t *testing.T) {
+	addrs, err := InterfaceAddresses()
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if len(addrs) < 1 {
+		t.Error("no addresses")
+	}
+
+	for _, a := range addrs {
+		if manet.IsIP6LinkLocal(a) {
+			t.Error("should not return ip link local addresses", a)
+		}
+	}
+
+	if len(addrs) < 1 {
+		t.Error("no good interface addrs")
+	}
+}
+
+func TestResolvingAddrs(t *testing.T) {
+
+	unspec := []ma.Multiaddr{
+		newMultiaddr(t, "/ip4/0.0.0.0/tcp/1234"),
+		newMultiaddr(t, "/ip4/1.2.3.4/tcp/1234"),
+		newMultiaddr(t, "/ip6/::/tcp/1234"),
+		newMultiaddr(t, "/ip6/::100/tcp/1234"),
+	}
+
+	iface := []ma.Multiaddr{
+		newMultiaddr(t, "/ip4/127.0.0.1"),
+		newMultiaddr(t, "/ip4/10.20.30.40"),
+		newMultiaddr(t, "/ip6/::1"),
+		newMultiaddr(t, "/ip6/::f"),
+	}
+
+	spec := []ma.Multiaddr{
+		newMultiaddr(t, "/ip4/127.0.0.1/tcp/1234"),
+		newMultiaddr(t, "/ip4/10.20.30.40/tcp/1234"),
+		newMultiaddr(t, "/ip4/1.2.3.4/tcp/1234"),
+		newMultiaddr(t, "/ip6/::1/tcp/1234"),
+		newMultiaddr(t, "/ip6/::f/tcp/1234"),
+		newMultiaddr(t, "/ip6/::100/tcp/1234"),
+	}
+
+	actual, err := ResolveUnspecifiedAddresses(unspec, iface)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	for i, a := range actual {
+		if !a.Equal(spec[i]) {
+			t.Error(a, " != ", spec[i])
+		}
+	}
+
+	ip4u := []ma.Multiaddr{newMultiaddr(t, "/ip4/0.0.0.0")}
+	ip4i := []ma.Multiaddr{newMultiaddr(t, "/ip4/1.2.3.4")}
+
+	ip6u := []ma.Multiaddr{newMultiaddr(t, "/ip6/::")}
+	ip6i := []ma.Multiaddr{newMultiaddr(t, "/ip6/::1")}
+
+	if _, err := ResolveUnspecifiedAddress(ip4u[0], ip6i); err == nil {
+		t.Fatal("should have failed")
+	}
+	if _, err := ResolveUnspecifiedAddress(ip6u[0], ip4i); err == nil {
+		t.Fatal("should have failed")
+	}
+
+	if _, err := ResolveUnspecifiedAddresses(ip6u, ip4i); err == nil {
+		t.Fatal("should have failed")
+	}
+	if _, err := ResolveUnspecifiedAddresses(ip4u, ip6i); err == nil {
+		t.Fatal("should have failed")
+	}
+
+}
+
+func TestWANShareable(t *testing.T) {
+
+	wanok := []ma.Multiaddr{
+		newMultiaddr(t, "/ip4/1.2.3.4/tcp/1234"),
+		newMultiaddr(t, "/ip6/abcd::1/tcp/1234"),
+	}
+
+	wanbad := []ma.Multiaddr{
+		newMultiaddr(t, "/ip4/127.0.0.1/tcp/1234"),
+		newMultiaddr(t, "/ip4/0.0.0.0/tcp/1234"),
+		newMultiaddr(t, "/ip6/::1/tcp/1234"),
+		newMultiaddr(t, "/ip6/::/tcp/1234"),
+		newMultiaddr(t, "/ip6/fe80::1/tcp/1234"),
+		newMultiaddr(t, "/ip6/fe80::/tcp/1234"),
+	}
+
+	for _, a := range wanok {
+		if !AddrIsShareableOnWAN(a) {
+			t.Error("should be true", a)
+		}
+	}
+
+	for _, a := range wanbad {
+		if AddrIsShareableOnWAN(a) {
+			t.Error("should be false", a)
+		}
+	}
+
+	wanok2 := WANShareableAddrs(wanok)
+	if len(wanok) != len(wanok2) {
+		t.Error("should be the same")
+	}
+
+	wanbad2 := WANShareableAddrs(wanbad)
+	if len(wanbad2) != 0 {
+		t.Error("should be zero")
+	}
+}

net/swarm/swarm.go

@@ -3,7 +3,10 @@
 package swarm
 
 import (
+	"fmt"
+
 	inet "github.com/jbenet/go-ipfs/p2p/net"
+	addrutil "github.com/jbenet/go-ipfs/p2p/net/swarm/addr"
 	peer "github.com/jbenet/go-ipfs/p2p/peer"
 	eventlog "github.com/jbenet/go-ipfs/util/eventlog"
 
@@ -37,6 +40,14 @@ type Swarm struct {
 func NewSwarm(ctx context.Context, listenAddrs []ma.Multiaddr,
 	local peer.ID, peers peer.Peerstore) (*Swarm, error) {
 
+	if len(listenAddrs) > 0 {
+		filtered := addrutil.FilterAddrs(listenAddrs)
+		if len(filtered) < 1 {
+			return nil, fmt.Errorf("swarm cannot use any addr in: %s", listenAddrs)
+		}
+		listenAddrs = filtered
+	}
+
 	s := &Swarm{
 		swarm: ps.NewSwarm(PSTransport),
 		local: local,

net/swarm/swarm_addr.go

@@ -0,0 +1,39 @@
+package swarm
+
+import (
+	conn "github.com/jbenet/go-ipfs/p2p/net/conn"
+	addrutil "github.com/jbenet/go-ipfs/p2p/net/swarm/addr"
+
+	ma "github.com/jbenet/go-ipfs/Godeps/_workspace/src/github.com/jbenet/go-multiaddr"
+)
+
+// 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 addrutil.ResolveUnspecifiedAddresses(s.ListenAddresses(), nil)
+}
+
+// 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) {
+	listen, err := InterfaceListenAddresses(s)
+	if err != nil {
+		log.Errorf("Error retrieving swarm.InterfaceListenAddresses: %s", err)
+		return
+	}
+
+	addrutil.CheckNATWarning(observed, expected, listen)
+}

net/swarm/addr_test.go → net/swarm/swarm_addr_test.go

@@ -3,6 +3,7 @@ package swarm
 import (
 	"testing"
 
+	addrutil "github.com/jbenet/go-ipfs/p2p/net/swarm/addr"
 	peer "github.com/jbenet/go-ipfs/p2p/peer"
 	testutil "github.com/jbenet/go-ipfs/util/testutil"
 
@@ -25,6 +26,8 @@ func TestFilterAddrs(t *testing.T) {
 		m("/ip4/1.2.3.4/udp/1234/sctp/1234"), // not in manet
 		m("/ip4/1.2.3.4/udp/1234/utp"),       // utp is broken
 		m("/ip4/1.2.3.4/udp/1234/udt"),       // udt is broken on arm
+		m("/ip6/fe80::1/tcp/1234"),           // link local
+		m("/ip6/fe80::100/tcp/1234"),         // link local
 	}
 
 	good := []ma.Multiaddr{
@@ -37,20 +40,20 @@ func TestFilterAddrs(t *testing.T) {
 	// test filters
 
 	for _, a := range bad {
-		if AddrUsable(a) {
+		if addrutil.AddrUsable(a, true) {
 			t.Errorf("addr %s should be unusable", a)
 		}
 	}
 
 	for _, a := range good {
-		if !AddrUsable(a) {
+		if !addrutil.AddrUsable(a, true) {
 			t.Errorf("addr %s should be usable", a)
 		}
 	}
 
-	subtestAddrsEqual(t, FilterAddrs(bad), []ma.Multiaddr{})
+	subtestAddrsEqual(t, addrutil.FilterAddrs(bad), []ma.Multiaddr{})
-	subtestAddrsEqual(t, FilterAddrs(good), good)
+	subtestAddrsEqual(t, addrutil.FilterAddrs(good), good)
-	subtestAddrsEqual(t, FilterAddrs(goodAndBad), good)
+	subtestAddrsEqual(t, addrutil.FilterAddrs(goodAndBad), good)
 
 	// now test it with swarm
 
@@ -95,3 +98,29 @@ func subtestAddrsEqual(t *testing.T, a, b []ma.Multiaddr) {
 		}
 	}
 }
+
+func TestDialBadAddrs(t *testing.T) {
+
+	m := func(s string) ma.Multiaddr {
+		maddr, err := ma.NewMultiaddr(s)
+		if err != nil {
+			t.Fatal(err)
+		}
+		return maddr
+	}
+
+	ctx := context.Background()
+	s := makeSwarms(ctx, t, 1)[0]
+
+	test := func(a ma.Multiaddr) {
+		p := testutil.RandPeerIDFatal(t)
+		s.peers.AddAddress(p, a)
+		if _, err := s.Dial(ctx, p); err == nil {
+			t.Error("swarm should not dial: %s", m)
+		}
+	}
+
+	test(m("/ip6/fe80::1"))                // link local
+	test(m("/ip6/fe80::100"))              // link local
+	test(m("/ip4/127.0.0.1/udp/1234/utp")) // utp
+}

net/swarm/swarm_dial.go

@@ -5,6 +5,7 @@ import (
 	"fmt"
 
 	conn "github.com/jbenet/go-ipfs/p2p/net/conn"
+	addrutil "github.com/jbenet/go-ipfs/p2p/net/swarm/addr"
 	peer "github.com/jbenet/go-ipfs/p2p/peer"
 	lgbl "github.com/jbenet/go-ipfs/util/eventlog/loggables"
 
@@ -38,6 +39,8 @@ func (s *Swarm) Dial(ctx context.Context, p peer.ID) (*Conn, error) {
 	}
 
 	remoteAddrs := s.peers.Addresses(p)
+	// make sure we can use the addresses.
+	remoteAddrs = addrutil.FilterAddrs(remoteAddrs)
 	if len(remoteAddrs) == 0 {
 		return nil, errors.New("peer has no addresses")
 	}
@@ -67,6 +70,9 @@ func (s *Swarm) Dial(ctx context.Context, p peer.ID) (*Conn, error) {
 	if err != nil {
 		return nil, err
 	}
+	if connC == nil {
+		err = fmt.Errorf("failed to dial %s", p)
+	}
 
 	// ok try to setup the new connection.
 	swarmC, err := dialConnSetup(ctx, s, connC)

net/swarm/swarm_listen.go

@@ -4,6 +4,7 @@ import (
 	"fmt"
 
 	conn "github.com/jbenet/go-ipfs/p2p/net/conn"
+	addrutil "github.com/jbenet/go-ipfs/p2p/net/swarm/addr"
 	lgbl "github.com/jbenet/go-ipfs/util/eventlog/loggables"
 
 	context "github.com/jbenet/go-ipfs/Godeps/_workspace/src/code.google.com/p/go.net/context"
@@ -16,7 +17,7 @@ import (
 func (s *Swarm) listen(addrs []ma.Multiaddr) error {
 
 	for _, addr := range addrs {
-		if !AddrUsable(addr) {
+		if !addrutil.AddrUsable(addr, true) {
 			return fmt.Errorf("cannot use addr: %s", addr)
 		}
 	}
@@ -59,10 +60,12 @@ func (s *Swarm) setupListener(maddr ma.Multiaddr) error {
 		// may be fine for sk to be nil, just log a warning.
 		log.Warning("Listener not given PrivateKey, so WILL NOT SECURE conns.")
 	}
+	log.Infof("Swarm Listening at %s", maddr)
 	list, err := conn.Listen(s.cg.Context(), maddr, s.local, sk)
 	if err != nil {
 		return err
 	}
+	log.Infof("Swarm Listening at %s", s.ListenAddresses())
 
 	// AddListener to the peerstream Listener. this will begin accepting connections
 	// and streams!