8 "github.com/anacrolix/log"
9 "github.com/anacrolix/missinggo/perf"
10 "github.com/anacrolix/missinggo/v2"
11 "github.com/anacrolix/torrent/dialer"
12 "github.com/pkg/errors"
15 type Listener interface {
16 // Accept waits for and returns the next connection to the listener.
17 Accept() (net.Conn, error)
19 // Addr returns the listener's network address.
23 type socket interface {
29 func listen(n network, addr string, f firewallCallback, logger log.Logger) (socket, error) {
32 return listenTcp(n.String(), addr)
34 return listenUtp(n.String(), addr, f, logger)
40 func listenTcp(network, address string) (s socket, err error) {
41 l, err := net.Listen(network, address)
44 NetworkDialer: NetworkDialer{
46 Dialer: dialer.Default,
51 type tcpSocket struct {
56 func listenAll(networks []network, getHost func(string) string, port int, f firewallCallback, logger log.Logger) ([]socket, error) {
57 if len(networks) == 0 {
60 var nahs []networkAndHost
61 for _, n := range networks {
62 nahs = append(nahs, networkAndHost{n, getHost(n.String())})
65 ss, retry, err := listenAllRetry(nahs, port, f, logger)
72 type networkAndHost struct {
77 func listenAllRetry(nahs []networkAndHost, port int, f firewallCallback, logger log.Logger) (ss []socket, retry bool, err error) {
78 ss = make([]socket, 1, len(nahs))
79 portStr := strconv.FormatInt(int64(port), 10)
80 ss[0], err = listen(nahs[0].Network, net.JoinHostPort(nahs[0].Host, portStr), f, logger)
82 return nil, false, errors.Wrap(err, "first listen")
85 if err != nil || retry {
86 for _, s := range ss {
92 portStr = strconv.FormatInt(int64(missinggo.AddrPort(ss[0].Addr())), 10)
93 for _, nah := range nahs[1:] {
94 s, err := listen(nah.Network, net.JoinHostPort(nah.Host, portStr), f, logger)
97 missinggo.IsAddrInUse(err) && port == 0,
98 errors.Wrap(err, "subsequent listen")
105 // This isn't aliased from go-libutp since that assumes CGO.
106 type firewallCallback func(net.Addr) bool
108 func listenUtp(network, addr string, fc firewallCallback, logger log.Logger) (socket, error) {
109 us, err := NewUtpSocket(network, addr, fc, logger)
110 return utpSocketSocket{us, network}, err
113 // utpSocket wrapper, additionally wrapped for the torrent package's socket interface.
114 type utpSocketSocket struct {
119 func (me utpSocketSocket) DialerNetwork() string {
123 func (me utpSocketSocket) Dial(ctx context.Context, addr string) (conn net.Conn, err error) {
124 defer perf.ScopeTimerErr(&err)()
125 return me.utpSocket.DialContext(ctx, me.network, addr)