package internet import ( "context" "v2ray.com/core/common/net" "v2ray.com/core/common/session" ) // Dialer is the interface for dialing outbound connections. type Dialer interface { // Dial dials a system connection to the given destination. Dial(ctx context.Context, destination net.Destination) (Connection, error) } // dialFunc is an interface to dial network connection to a specific destination. type dialFunc func(ctx context.Context, dest net.Destination) (Connection, error) var ( transportDialerCache = make(map[string]dialFunc) ) // RegisterTransportDialer registers a Dialer with given name. func RegisterTransportDialer(protocol string, dialer dialFunc) error { if _, found := transportDialerCache[protocol]; found { return newError(protocol, " dialer already registered").AtError() } transportDialerCache[protocol] = dialer return nil } // Dial dials a internet connection towards the given destination. func Dial(ctx context.Context, dest net.Destination) (Connection, error) { if dest.Network == net.Network_TCP { streamSettings := StreamSettingsFromContext(ctx) if streamSettings == nil { s, err := ToMemoryStreamConfig(nil) if err != nil { return nil, newError("failed to create default stream settings").Base(err) } streamSettings = s ctx = ContextWithStreamSettings(ctx, streamSettings) } protocol := streamSettings.ProtocolName dialer := transportDialerCache[protocol] if dialer == nil { return nil, newError(protocol, " dialer not registered").AtError() } return dialer(ctx, dest) } if dest.Network == net.Network_UDP { udpDialer := transportDialerCache["udp"] if udpDialer == nil { return nil, newError("UDP dialer not registered").AtError() } return udpDialer(ctx, dest) } return nil, newError("unknown network ", dest.Network) } // DialSystem calls system dialer to create a network connection. func DialSystem(ctx context.Context, dest net.Destination) (net.Conn, error) { var src net.Address if outbound := session.OutboundFromContext(ctx); outbound != nil { src = outbound.Gateway } return effectiveSystemDialer.Dial(ctx, src, dest) }