// returns the two endpoints of a TCP connection over lo0
func getTCPConnectionPair() (net.Conn, net.Conn, error) {
lst, err := net.Listen("tcp", "127.0.0.1:0")
if err != nil {
return nil, nil, err
}
// We run the Accept in the background since it's blocking, and we use
// the channel to make the race thingies happy about writing vs reading
// conn0 and err0.
var conn0 net.Conn
var err0 error
done := make(chan struct{})
go func() {
conn0, err0 = lst.Accept()
close(done)
}()
// Dial the connection
conn1, err := net.Dial("tcp", lst.Addr().String())
if err != nil {
return nil, nil, err
}
// Check any error from accept
<-done
if err0 != nil {
return nil, nil, err0
}
// Set the buffer sizes etc as usual
dialer.SetTCPOptions(conn0)
dialer.SetTCPOptions(conn1)
return conn0, conn1, nil
}
func (d *tcpDialer) Dial(id protocol.DeviceID, uri *url.URL) (internalConn, error) {
uri = fixupPort(uri)
conn, err := dialer.DialTimeout(uri.Scheme, uri.Host, 10*time.Second)
if err != nil {
l.Debugln(err)
return internalConn{}, err
}
err = dialer.SetTCPOptions(conn)
if err != nil {
l.Infoln(err)
}
err = dialer.SetTrafficClass(conn, d.cfg.Options().TrafficClass)
if err != nil {
l.Debugf("failed to set traffic class: %s", err)
}
tc := tls.Client(conn, d.tlsCfg)
err = tlsTimedHandshake(tc)
if err != nil {
tc.Close()
return internalConn{}, err
}
return internalConn{tc, connTypeTCPClient, tcpPriority}, nil
}
func (d *relayDialer) Dial(id protocol.DeviceID, uri *url.URL) (IntermediateConnection, error) {
inv, err := client.GetInvitationFromRelay(uri, id, d.tlsCfg.Certificates, 10*time.Second)
if err != nil {
return IntermediateConnection{}, err
}
conn, err := client.JoinSession(inv)
if err != nil {
return IntermediateConnection{}, err
}
err = dialer.SetTCPOptions(conn)
if err != nil {
conn.Close()
return IntermediateConnection{}, err
}
var tc *tls.Conn
if inv.ServerSocket {
tc = tls.Server(conn, d.tlsCfg)
} else {
tc = tls.Client(conn, d.tlsCfg)
}
err = tc.Handshake()
if err != nil {
tc.Close()
return IntermediateConnection{}, err
}
return IntermediateConnection{tc, "Relay (Client)", relayPriority}, nil
}
func makeTCPListener(network string) ListenerFactory {
return func(uri *url.URL, tlsCfg *tls.Config, conns chan<- model.IntermediateConnection) {
tcaddr, err := net.ResolveTCPAddr(network, uri.Host)
if err != nil {
l.Fatalln("listen (BEP/tcp):", err)
return
}
listener, err := net.ListenTCP(network, tcaddr)
if err != nil {
l.Fatalln("listen (BEP/tcp):", err)
return
}
for {
conn, err := listener.Accept()
if err != nil {
l.Warnln("Accepting connection (BEP/tcp):", err)
continue
}
l.Debugln("connect from", conn.RemoteAddr())
err = dialer.SetTCPOptions(conn.(*net.TCPConn))
if err != nil {
l.Infoln(err)
}
tc := tls.Server(conn, tlsCfg)
err = tc.Handshake()
if err != nil {
l.Infoln("TLS handshake (BEP/tcp):", err)
tc.Close()
continue
}
conns <- model.IntermediateConnection{
Conn: tc,
Type: model.ConnectionTypeDirectAccept,
}
}
}
}
func (d *relayDialer) Dial(id protocol.DeviceID, uri *url.URL) (internalConn, error) {
inv, err := client.GetInvitationFromRelay(uri, id, d.tlsCfg.Certificates, 10*time.Second)
if err != nil {
return internalConn{}, err
}
conn, err := client.JoinSession(inv)
if err != nil {
return internalConn{}, err
}
err = dialer.SetTCPOptions(conn)
if err != nil {
conn.Close()
return internalConn{}, err
}
err = dialer.SetTrafficClass(conn, d.cfg.Options().TrafficClass)
if err != nil {
l.Debugf("failed to set traffic class: %s", err)
}
var tc *tls.Conn
if inv.ServerSocket {
tc = tls.Server(conn, d.tlsCfg)
} else {
tc = tls.Client(conn, d.tlsCfg)
}
err = tlsTimedHandshake(tc)
if err != nil {
tc.Close()
return internalConn{}, err
}
return internalConn{tc, connTypeRelayClient, relayPriority}, nil
}
func (t *relayListener) Serve() {
t.mut.Lock()
t.err = nil
t.mut.Unlock()
clnt, err := client.NewClient(t.uri, t.tlsCfg.Certificates, nil, 10*time.Second)
if err != nil {
t.mut.Lock()
t.err = err
t.mut.Unlock()
l.Warnln("listen (BEP/relay):", err)
return
}
go clnt.Serve()
t.mut.Lock()
t.client = clnt
t.mut.Unlock()
oldURI := clnt.URI()
for {
select {
case inv, ok := <-t.client.Invitations():
if !ok {
return
}
conn, err := client.JoinSession(inv)
if err != nil {
l.Warnln("Joining relay session (BEP/relay):", err)
continue
}
err = dialer.SetTCPOptions(conn.(*net.TCPConn))
if err != nil {
l.Infoln(err)
}
var tc *tls.Conn
if inv.ServerSocket {
tc = tls.Server(conn, t.tlsCfg)
} else {
tc = tls.Client(conn, t.tlsCfg)
}
err = tc.Handshake()
if err != nil {
tc.Close()
l.Infoln("TLS handshake (BEP/relay):", err)
continue
}
t.conns <- IntermediateConnection{tc, "Relay (Server)", relayPriority}
// Poor mans notifier that informs the connection service that the
// relay URI has changed. This can only happen when we connect to a
// relay via dynamic+http(s) pool, which upon a relay failing/dropping
// us, would pick a different one.
case <-time.After(10 * time.Second):
currentURI := clnt.URI()
if currentURI != oldURI {
oldURI = currentURI
t.notifyAddressesChanged(t)
}
}
}
}
func (t *tcpListener) Serve() {
t.mut.Lock()
t.err = nil
t.mut.Unlock()
tcaddr, err := net.ResolveTCPAddr(t.uri.Scheme, t.uri.Host)
if err != nil {
t.mut.Lock()
t.err = err
t.mut.Unlock()
l.Infoln("listen (BEP/tcp):", err)
return
}
listener, err := net.ListenTCP(t.uri.Scheme, tcaddr)
if err != nil {
t.mut.Lock()
t.err = err
t.mut.Unlock()
l.Infoln("listen (BEP/tcp):", err)
return
}
defer listener.Close()
l.Infof("TCP listener (%v) starting", listener.Addr())
defer l.Infof("TCP listener (%v) shutting down", listener.Addr())
mapping := t.natService.NewMapping(nat.TCP, tcaddr.IP, tcaddr.Port)
mapping.OnChanged(func(_ *nat.Mapping, _, _ []nat.Address) {
t.notifyAddressesChanged(t)
})
defer t.natService.RemoveMapping(mapping)
t.mut.Lock()
t.mapping = mapping
t.mut.Unlock()
for {
listener.SetDeadline(time.Now().Add(time.Second))
conn, err := listener.Accept()
select {
case <-t.stop:
if err == nil {
conn.Close()
}
t.mut.Lock()
t.mapping = nil
t.mut.Unlock()
return
default:
}
if err != nil {
if err, ok := err.(*net.OpError); !ok || !err.Timeout() {
l.Warnln("Accepting connection (BEP/tcp):", err)
}
continue
}
l.Debugln("connect from", conn.RemoteAddr())
err = dialer.SetTCPOptions(conn)
if err != nil {
l.Infoln(err)
}
tc := tls.Server(conn, t.tlsCfg)
err = tc.Handshake()
if err != nil {
l.Infoln("TLS handshake (BEP/tcp):", err)
tc.Close()
continue
}
t.conns <- IntermediateConnection{tc, "TCP (Server)", tcpPriority}
}
}