// dial is the actual swarm's dial logic, gated by Dial.
func (s *Swarm) dial(ctx context.Context, p peer.ID) (*Conn, error) {
var logdial = lgbl.Dial("swarm", s.LocalPeer(), p, nil, nil)
if p == s.local {
log.Event(ctx, "swarmDialDoDialSelf", logdial)
return nil, ErrDialToSelf
}
defer log.EventBegin(ctx, "swarmDialDo", logdial).Done()
logdial["dial"] = "failure" // start off with failure. set to "success" at the end.
sk := s.peers.PrivKey(s.local)
logdial["encrypted"] = (sk != nil) // log wether this will be an encrypted dial or not.
if sk == nil {
// fine for sk to be nil, just log.
log.Debug("Dial not given PrivateKey, so WILL NOT SECURE conn.")
}
// get remote peer addrs
remoteAddrs := s.peers.Addrs(p)
// make sure we can use the addresses.
remoteAddrs = addrutil.FilterUsableAddrs(remoteAddrs)
// drop out any addrs that would just dial ourselves. use ListenAddresses
// as that is a more authoritative view than localAddrs.
ila, _ := s.InterfaceListenAddresses()
remoteAddrs = addrutil.Subtract(remoteAddrs, ila)
remoteAddrs = addrutil.Subtract(remoteAddrs, s.peers.Addrs(s.local))
log.Debugf("%s swarm dialing %s -- local:%s remote:%s", s.local, p, s.ListenAddresses(), remoteAddrs)
if len(remoteAddrs) == 0 {
err := errors.New("peer has no addresses")
logdial["error"] = err
return nil, err
}
remoteAddrs = s.filterAddrs(remoteAddrs)
if len(remoteAddrs) == 0 {
err := errors.New("all adresses for peer have been filtered out")
logdial["error"] = err
return nil, err
}
// try to get a connection to any addr
connC, err := s.dialAddrs(ctx, p, remoteAddrs)
if err != nil {
logdial["error"] = err
return nil, err
}
logdial["netconn"] = lgbl.NetConn(connC)
// ok try to setup the new connection.
defer log.EventBegin(ctx, "swarmDialDoSetup", logdial, lgbl.NetConn(connC)).Done()
swarmC, err := dialConnSetup(ctx, s, connC)
if err != nil {
logdial["error"] = err
connC.Close() // close the connection. didn't work out :(
return nil, err
}
logdial["dial"] = "success"
return swarmC, nil
}
func filterAddrs(listenAddrs []ma.Multiaddr) ([]ma.Multiaddr, error) {
if len(listenAddrs) > 0 {
filtered := addrutil.FilterUsableAddrs(listenAddrs)
if len(filtered) < 1 {
return nil, fmt.Errorf("swarm cannot use any addr in: %s", listenAddrs)
}
listenAddrs = filtered
}
return listenAddrs, nil
}
func TestFilterAddrs(t *testing.T) {
m := func(s string) ma.Multiaddr {
maddr, err := ma.NewMultiaddr(s)
if err != nil {
t.Fatal(err)
}
return maddr
}
bad := []ma.Multiaddr{
m("/ip4/1.2.3.4/udp/1234"), // unreliable
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/0"), // link local
m("/ip6/fe80::100/tcp/1234"), // link local
}
good := []ma.Multiaddr{
m("/ip4/127.0.0.1/tcp/0"),
m("/ip6/::1/tcp/0"),
}
goodAndBad := append(good, bad...)
// test filters
for _, a := range bad {
if addrutil.AddrUsable(a, true) {
t.Errorf("addr %s should be unusable", a)
}
}
for _, a := range good {
if !addrutil.AddrUsable(a, true) {
t.Errorf("addr %s should be usable", a)
}
}
subtestAddrsEqual(t, addrutil.FilterUsableAddrs(bad), []ma.Multiaddr{})
subtestAddrsEqual(t, addrutil.FilterUsableAddrs(good), good)
subtestAddrsEqual(t, addrutil.FilterUsableAddrs(goodAndBad), good)
// now test it with swarm
id, err := testutil.RandPeerID()
if err != nil {
t.Fatal(err)
}
ps := peer.NewPeerstore()
ctx := context.Background()
if _, err := NewNetwork(ctx, bad, id, ps, metrics.NewBandwidthCounter()); err == nil {
t.Fatal("should have failed to create swarm")
}
if _, err := NewNetwork(ctx, goodAndBad, id, ps, metrics.NewBandwidthCounter()); err != nil {
t.Fatal("should have succeeded in creating swarm", err)
}
}