swarm: fix selection of transport for dialing

With WebTransport's /webtransport/certhash/xyz addresses, the assumption that
the last component of a multiaddr identifies the transport to use for dialing
doesn't hold any more.
Note that WebRTC will probably also use the certhash multiaddr component to
encode its certificate hashes.

go.mod

@@ -32,12 +32,14 @@ require (
 	github.com/libp2p/go-yamux/v3 v3.1.2
 	github.com/libp2p/zeroconf/v2 v2.1.1
 	github.com/lucas-clemente/quic-go v0.28.0
+	github.com/marten-seemann/go-libp2p-webtransport v0.0.0-20220709223343-dd402f085574
 	github.com/marten-seemann/tcp v0.0.0-20210406111302-dfbc87cc63fd
 	github.com/mikioh/tcpinfo v0.0.0-20190314235526-30a79bb1804b
 	github.com/minio/sha256-simd v1.0.0
 	github.com/multiformats/go-multiaddr v0.6.0
 	github.com/multiformats/go-multiaddr-dns v0.3.1
 	github.com/multiformats/go-multiaddr-fmt v0.1.0
+	github.com/multiformats/go-multibase v0.1.1
 	github.com/multiformats/go-multihash v0.1.0
 	github.com/multiformats/go-multistream v0.3.3
 	github.com/multiformats/go-varint v0.0.6
@@ -66,6 +68,7 @@ require (
 	github.com/go-task/slim-sprig v0.0.0-20210107165309-348f09dbbbc0 // indirect
 	github.com/godbus/dbus/v5 v5.1.0 // indirect
 	github.com/golang/protobuf v1.5.2 // indirect
+	github.com/google/go-cmp v0.5.6 // indirect
 	github.com/google/uuid v1.3.0 // indirect
 	github.com/huin/goupnp v1.0.3 // indirect
 	github.com/jackpal/go-nat-pmp v1.0.2 // indirect
@@ -74,11 +77,14 @@ require (
 	github.com/koron/go-ssdp v0.0.3 // indirect
 	github.com/libp2p/go-cidranger v1.1.0 // indirect
 	github.com/libp2p/go-flow-metrics v0.0.3 // indirect
+	github.com/libp2p/go-libp2p-noise v0.3.1-0.20220416173527-fe671ac5d0fc // indirect
 	github.com/libp2p/go-openssl v0.0.7 // indirect
+	github.com/marten-seemann/qpack v0.2.1 // indirect
 	github.com/marten-seemann/qtls-go1-16 v0.1.5 // indirect
 	github.com/marten-seemann/qtls-go1-17 v0.1.2 // indirect
 	github.com/marten-seemann/qtls-go1-18 v0.1.2 // indirect
 	github.com/marten-seemann/qtls-go1-19 v0.1.0-beta.1 // indirect
+	github.com/marten-seemann/webtransport-go v0.0.0-20220709212913-0bb1f0a11a30 // indirect
 	github.com/mattn/go-isatty v0.0.14 // indirect
 	github.com/matttproud/golang_protobuf_extensions v1.0.1 // indirect
 	github.com/miekg/dns v1.1.50 // indirect
@@ -87,7 +93,6 @@ require (
 	github.com/mr-tron/base58 v1.2.0 // indirect
 	github.com/multiformats/go-base32 v0.0.4 // indirect
 	github.com/multiformats/go-base36 v0.1.0 // indirect
-	github.com/multiformats/go-multibase v0.1.1 // indirect
 	github.com/multiformats/go-multicodec v0.5.0 // indirect
 	github.com/nxadm/tail v1.4.8 // indirect
 	github.com/onsi/ginkgo v1.16.5 // indirect
@@ -106,6 +111,7 @@ require (
 	go.uber.org/zap v1.21.0 // indirect
 	golang.org/x/mod v0.6.0-dev.0.20220419223038-86c51ed26bb4 // indirect
 	golang.org/x/net v0.0.0-20220630215102-69896b714898 // indirect
+	golang.org/x/text v0.3.7 // indirect
 	golang.org/x/tools v0.1.11 // indirect
 	golang.org/x/xerrors v0.0.0-20220609144429-65e65417b02f // indirect
 	google.golang.org/protobuf v1.28.0 // indirect

go.sum

@@ -60,6 +60,7 @@ github.com/beorn7/perks v1.0.1/go.mod h1:G2ZrVWU2WbWT9wwq4/hrbKbnv/1ERSJQ0ibhJ6r
 github.com/bradfitz/go-smtpd v0.0.0-20170404230938-deb6d6237625/go.mod h1:HYsPBTaaSFSlLx/70C2HPIMNZpVV8+vt/A+FMnYP11g=
 github.com/btcsuite/btcd v0.0.0-20190523000118-16327141da8c/go.mod h1:3J08xEfcugPacsc34/LKRU2yO7YmuT8yt28J8k2+rrI=
 github.com/btcsuite/btcd v0.20.1-beta/go.mod h1:wVuoA8VJLEcwgqHBwHmzLRazpKxTv13Px/pDuV7OomQ=
+github.com/btcsuite/btcd v0.21.0-beta/go.mod h1:ZSWyehm27aAuS9bvkATT+Xte3hjHZ+MRgMY/8NJ7K94=
 github.com/btcsuite/btcd v0.22.1 h1:CnwP9LM/M9xuRrGSCGeMVs9iv09uMqwsVX7EeIpgV2c=
 github.com/btcsuite/btcd v0.22.1/go.mod h1:wqgTSL29+50LRkmOVknEdmt8ZojIzhuWvgu/iptuN7Y=
 github.com/btcsuite/btcd/btcec/v2 v2.1.3/go.mod h1:ctjw4H1kknNJmRN4iP1R7bTQ+v3GJkZBd6mui8ZsAZE=
@@ -70,6 +71,7 @@ github.com/btcsuite/btcd/chaincfg/chainhash v1.0.1 h1:q0rUy8C/TYNBQS1+CGKw68tLOF
 github.com/btcsuite/btcd/chaincfg/chainhash v1.0.1/go.mod h1:7SFka0XMvUgj3hfZtydOrQY2mwhPclbT2snogU7SQQc=
 github.com/btcsuite/btclog v0.0.0-20170628155309-84c8d2346e9f/go.mod h1:TdznJufoqS23FtqVCzL0ZqgP5MqXbb4fg/WgDys70nA=
 github.com/btcsuite/btcutil v0.0.0-20190425235716-9e5f4b9a998d/go.mod h1:+5NJ2+qvTyV9exUAL/rxXi3DcLg2Ts+ymUAY5y4NvMg=
+github.com/btcsuite/btcutil v1.0.2/go.mod h1:j9HUFwoQRsZL3V4n+qG+CUnEGHOarIxfC3Le2Yhbcts=
 github.com/btcsuite/btcutil v1.0.3-0.20201208143702-a53e38424cce/go.mod h1:0DVlHczLPewLcPGEIeUEzfOJhqGPQ0mJJRDBtD307+o=
 github.com/btcsuite/go-socks v0.0.0-20170105172521-4720035b7bfd/go.mod h1:HHNXQzUsZCxOoE+CPiyCTO6x34Zs86zZUiwtpXoGdtg=
 github.com/btcsuite/goleveldb v0.0.0-20160330041536-7834afc9e8cd/go.mod h1:F+uVaaLLH7j4eDXPRvw78tMflu7Ie2bzYOH4Y8rRKBY=
@@ -214,8 +216,9 @@ github.com/google/go-cmp v0.5.1/go.mod h1:v8dTdLbMG2kIc/vJvl+f65V22dbkXbowE6jgT/
 github.com/google/go-cmp v0.5.2/go.mod h1:v8dTdLbMG2kIc/vJvl+f65V22dbkXbowE6jgT/gNBxE=
 github.com/google/go-cmp v0.5.3/go.mod h1:v8dTdLbMG2kIc/vJvl+f65V22dbkXbowE6jgT/gNBxE=
 github.com/google/go-cmp v0.5.4/go.mod h1:v8dTdLbMG2kIc/vJvl+f65V22dbkXbowE6jgT/gNBxE=
-github.com/google/go-cmp v0.5.5 h1:Khx7svrCpmxxtHBq5j2mp/xVjsi8hQMfNLvJFAlrGgU=
 github.com/google/go-cmp v0.5.5/go.mod h1:v8dTdLbMG2kIc/vJvl+f65V22dbkXbowE6jgT/gNBxE=
+github.com/google/go-cmp v0.5.6 h1:BKbKCqvP6I+rmFHt06ZmyQtvB8xAkWdhFyr0ZUNZcxQ=
+github.com/google/go-cmp v0.5.6/go.mod h1:v8dTdLbMG2kIc/vJvl+f65V22dbkXbowE6jgT/gNBxE=
 github.com/google/go-github v17.0.0+incompatible/go.mod h1:zLgOLi98H3fifZn+44m+umXrS52loVEgC2AApnigrVQ=
 github.com/google/go-querystring v1.0.0/go.mod h1:odCYkC5MyYFN7vkCjXpyrEuKhc/BUO6wN/zVPAxq5ck=
 github.com/google/gofuzz v1.0.0/go.mod h1:dBl0BpW6vV/+mYPU4Po3pmUjxk6FQPldtuIdl/M65Eg=
@@ -341,10 +344,13 @@ github.com/libp2p/go-libp2p-asn-util v0.2.0 h1:rg3+Os8jbnO5DxkC7K/Utdi+DkY3q/d1/
 github.com/libp2p/go-libp2p-asn-util v0.2.0/go.mod h1:WoaWxbHKBymSN41hWSq/lGKJEca7TNm58+gGJi2WsLI=
 github.com/libp2p/go-libp2p-core v0.2.0/go.mod h1:X0eyB0Gy93v0DZtSYbEM7RnMChm9Uv3j7yRXjO77xSI=
 github.com/libp2p/go-libp2p-core v0.5.7/go.mod h1:txwbVEhHEXikXn9gfC7/UDDw7rkxuX0bJvM49Ykaswo=
+github.com/libp2p/go-libp2p-core v0.10.0/go.mod h1:ECdxehoYosLYHgDDFa2N4yE8Y7aQRAMf0sX9mf2sbGg=
 github.com/libp2p/go-libp2p-core v0.12.0/go.mod h1:ECdxehoYosLYHgDDFa2N4yE8Y7aQRAMf0sX9mf2sbGg=
 github.com/libp2p/go-libp2p-core v0.19.0/go.mod h1:AkA+FUKQfYt1FLNef5fOPlo/naAWjKy/RCjkcPjqzYg=
 github.com/libp2p/go-libp2p-core v0.19.1 h1:zaZQQCeCrFMtxFa1wHy6AhsVynyNmZAvwgWqSSPT3WE=
 github.com/libp2p/go-libp2p-core v0.19.1/go.mod h1:2uLhmmqDiFY+dw+70KkBLeKvvsJHGWUINRDdeV1ip7k=
+github.com/libp2p/go-libp2p-noise v0.3.1-0.20220416173527-fe671ac5d0fc h1:UElmHYHy1pz62T4XvXKBRRlZnFw+Y4bsacnDFIJJZk8=
+github.com/libp2p/go-libp2p-noise v0.3.1-0.20220416173527-fe671ac5d0fc/go.mod h1:BzzY5pyzCYSyJbQy9oD8z5oP2idsafjt4/X42h9DjZU=
 github.com/libp2p/go-libp2p-peerstore v0.7.1 h1:7FpALlqR+3+oOBXdzm3AVt0vjMYLW1b7jM03E4iEHlw=
 github.com/libp2p/go-libp2p-peerstore v0.7.1/go.mod h1:cdUWTHro83vpg6unCpGUr8qJoX3e93Vy8o97u5ppIM0=
 github.com/libp2p/go-libp2p-resource-manager v0.5.1 h1:jm0mdqn7yfh7wbUzlj948BYZX0KZ3RW7OqerkGQ5rYY=
@@ -380,6 +386,9 @@ github.com/lunixbochs/vtclean v1.0.0/go.mod h1:pHhQNgMf3btfWnGBVipUOjRYhoOsdGqdm
 github.com/magiconair/properties v1.8.0/go.mod h1:PppfXfuXeibc/6YijjN8zIbojt8czPbwD3XqdrwzmxQ=
 github.com/mailru/easyjson v0.0.0-20180823135443-60711f1a8329/go.mod h1:C1wdFJiN94OJF2b5HbByQZoLdCWB1Yqtg26g4irojpc=
 github.com/mailru/easyjson v0.0.0-20190312143242-1de009706dbe/go.mod h1:C1wdFJiN94OJF2b5HbByQZoLdCWB1Yqtg26g4irojpc=
+github.com/marten-seemann/go-libp2p-webtransport v0.0.0-20220709223343-dd402f085574 h1:nzc+PjGoJ1ouKfuIn+3t5jGKblYKAsY89bXZpK4U5sE=
+github.com/marten-seemann/go-libp2p-webtransport v0.0.0-20220709223343-dd402f085574/go.mod h1:QPHUeHpFR0qKSnvkEMdpykASQheUMRsNhnjDoniKZvQ=
+github.com/marten-seemann/qpack v0.2.1 h1:jvTsT/HpCn2UZJdP+UUB53FfUUgeOyG5K1ns0OJOGVs=
 github.com/marten-seemann/qpack v0.2.1/go.mod h1:F7Gl5L1jIgN1D11ucXefiuJS9UMVP2opoCp2jDKb7wc=
 github.com/marten-seemann/qtls-go1-16 v0.1.5 h1:o9JrYPPco/Nukd/HpOHMHZoBDXQqoNtUCmny98/1uqQ=
 github.com/marten-seemann/qtls-go1-16 v0.1.5/go.mod h1:gNpI2Ol+lRS3WwSOtIUUtRwZEQMXjYK+dQSBFbethAk=
@@ -391,6 +400,8 @@ github.com/marten-seemann/qtls-go1-19 v0.1.0-beta.1 h1:7m/WlWcSROrcK5NxuXaxYD32B
 github.com/marten-seemann/qtls-go1-19 v0.1.0-beta.1/go.mod h1:5HTDWtVudo/WFsHKRNuOhWlbdjrfs5JHrYb0wIJqGpI=
 github.com/marten-seemann/tcp v0.0.0-20210406111302-dfbc87cc63fd h1:br0buuQ854V8u83wA0rVZ8ttrq5CpaPZdvrK0LP2lOk=
 github.com/marten-seemann/tcp v0.0.0-20210406111302-dfbc87cc63fd/go.mod h1:QuCEs1Nt24+FYQEqAAncTDPJIuGs+LxK1MCiFL25pMU=
+github.com/marten-seemann/webtransport-go v0.0.0-20220709212913-0bb1f0a11a30 h1:kdMt8RUL0RGrqoXFFVPEOVeUyvbQtvAKvsUt4DjowKQ=
+github.com/marten-seemann/webtransport-go v0.0.0-20220709212913-0bb1f0a11a30/go.mod h1:IPUrXi7wxfqwTfFSPFlRXFJZPgHO8kG0qrqn3/JTXEQ=
 github.com/mattn/go-colorable v0.0.9/go.mod h1:9vuHe8Xs5qXnSaW/c/ABM9alt+Vo+STaOChaDxuIBZU=
 github.com/mattn/go-isatty v0.0.4/go.mod h1:M+lRXTBqGeGNdLjl/ufCoiOlB5xdOkqRJdNxMWT7Zi4=
 github.com/mattn/go-isatty v0.0.13/go.mod h1:cbi8OIDigv2wuxKPP5vlRcQ1OAZbq2CE4Kysco4FUpU=
@@ -442,6 +453,7 @@ github.com/multiformats/go-multiaddr v0.2.0/go.mod h1:0nO36NvPpyV4QzvTLi/lafl2y9
 github.com/multiformats/go-multiaddr v0.2.2/go.mod h1:NtfXiOtHvghW9KojvtySjH5y0u0xW5UouOmQQrn6a3Y=
 github.com/multiformats/go-multiaddr v0.3.3/go.mod h1:lCKNGP1EQ1eZ35Za2wlqnabm9xQkib3fyB+nZXHLag0=
 github.com/multiformats/go-multiaddr v0.4.1/go.mod h1:3afI9HfVW8csiF8UZqtpYRiDyew8pRX7qLIGHu9FLuM=
+github.com/multiformats/go-multiaddr v0.5.1-0.20220406114920-a07348aac403/go.mod h1:F4IpaKZuPP360tOMn2Tpyu0At8w23aRyVqeK0DbFeGM=
 github.com/multiformats/go-multiaddr v0.6.0 h1:qMnoOPj2s8xxPU5kZ57Cqdr0hHhARz7mFsPMIiYNqzg=
 github.com/multiformats/go-multiaddr v0.6.0/go.mod h1:F4IpaKZuPP360tOMn2Tpyu0At8w23aRyVqeK0DbFeGM=
 github.com/multiformats/go-multiaddr-dns v0.3.1 h1:QgQgR+LQVt3NPTjbrLLpsaT2ufAA2y0Mkk+QRVJbW3A=

p2p/net/swarm/swarm_addr_test.go

@@ -2,14 +2,24 @@ package swarm_test
 
 import (
 	"context"
+	"fmt"
 	"testing"
 
+	"github.com/libp2p/go-libp2p/p2p/net/swarm"
 	swarmt "github.com/libp2p/go-libp2p/p2p/net/swarm/testing"
+	circuitv2 "github.com/libp2p/go-libp2p/p2p/protocol/circuitv2/client"
+	quic "github.com/libp2p/go-libp2p/p2p/transport/quic"
+	"github.com/libp2p/go-libp2p/p2p/transport/tcp"
 
 	"github.com/libp2p/go-libp2p-core/peerstore"
 	"github.com/libp2p/go-libp2p-core/test"
 
+	tnet "github.com/libp2p/go-libp2p-testing/net"
+	webtransport "github.com/marten-seemann/go-libp2p-webtransport"
+	"github.com/minio/sha256-simd"
 	ma "github.com/multiformats/go-multiaddr"
+	"github.com/multiformats/go-multibase"
+	"github.com/multiformats/go-multihash"
 	"github.com/stretchr/testify/require"
 )
 
@@ -57,3 +67,34 @@ func TestAddressesWithoutListening(t *testing.T) {
 	require.NoError(t, err)
 	require.Empty(t, a1, "expected to be listening on no addresses")
 }
+
+func TestDialAddressSelection(t *testing.T) {
+	id := tnet.RandIdentityOrFatal(t)
+	s, err := swarm.NewSwarm("local", nil)
+	require.NoError(t, err)
+
+	tcpTr, err := tcp.NewTCPTransport(nil, nil)
+	require.NoError(t, err)
+	require.NoError(t, s.AddTransport(tcpTr))
+	quicTr, err := quic.NewTransport(id.PrivateKey(), nil, nil, nil)
+	require.NoError(t, err)
+	require.NoError(t, s.AddTransport(quicTr))
+	webtransportTr, err := webtransport.New(id.PrivateKey(), nil, nil)
+	require.NoError(t, err)
+	require.NoError(t, s.AddTransport(webtransportTr))
+	h := sha256.Sum256([]byte("foo"))
+	hash, err := multihash.Encode(h[:], multihash.SHA2_256)
+	require.NoError(t, err)
+	certHash, err := multibase.Encode(multibase.Base58BTC, hash)
+	require.NoError(t, err)
+	circuitTr, err := circuitv2.New(nil, nil)
+	require.NoError(t, err)
+	require.NoError(t, s.AddTransport(circuitTr))
+
+	require.Equal(t, tcpTr, s.TransportForDialing(ma.StringCast("/ip4/127.0.0.1/tcp/1234")))
+	require.Equal(t, quicTr, s.TransportForDialing(ma.StringCast("/ip4/127.0.0.1/udp/1234/quic")))
+	require.Equal(t, circuitTr, s.TransportForDialing(ma.StringCast(fmt.Sprintf("/ip4/127.0.0.1/udp/1234/quic/p2p-circuit/p2p/%s", id.ID()))))
+	require.Equal(t, webtransportTr, s.TransportForDialing(ma.StringCast(fmt.Sprintf("/ip4/127.0.0.1/udp/1234/quic/webtransport/certhash/%s", certHash))))
+	require.Nil(t, s.TransportForDialing(ma.StringCast("/ip4/1.2.3.4")))
+	require.Nil(t, s.TransportForDialing(ma.StringCast("/ip4/1.2.3.4/tcp/443/ws")))
+}

p2p/net/swarm/swarm_transport.go

@@ -19,25 +19,23 @@ func (s *Swarm) TransportForDialing(a ma.Multiaddr) transport.Transport {
 
 	s.transports.RLock()
 	defer s.transports.RUnlock()
+
 	if len(s.transports.m) == 0 {
 		// make sure we're not just shutting down.
 		if s.transports.m != nil {
 			log.Error("you have no transports configured")
 		}
 		return nil
 	}
-
-	for _, p := range protocols {
-		transport, ok := s.transports.m[p.Code]
-		if !ok {
-			continue
-		}
-		if transport.Proxy() {
-			return transport
+	if isRelayAddr(a) {
+		return s.transports.m[ma.P_CIRCUIT]
+	}
+	for _, t := range s.transports.m {
+		if t.CanDial(a) {
+			return t
 		}
 	}
-
-	return s.transports.m[protocols[len(protocols)-1].Code]
+	return nil
 }
 
 // TransportForListening retrieves the appropriate transport for listening on