func (this *SocksServer) handleUDP(reader io.Reader, writer *v2io.BufferedWriter) error {
response := protocol.NewSocks5Response()
response.Error = protocol.ErrorSuccess
udpAddr := this.udpAddress
response.Port = udpAddr.Port()
switch {
case udpAddr.Address().IsIPv4():
response.SetIPv4(udpAddr.Address().IP())
case udpAddr.Address().IsIPv6():
response.SetIPv6(udpAddr.Address().IP())
case udpAddr.Address().IsDomain():
response.SetDomain(udpAddr.Address().Domain())
}
response.Write(writer)
err := writer.Flush()
if err != nil {
log.Error("Socks: failed to write response: ", err)
return err
}
// The TCP connection closes after this method returns. We need to wait until
// the client closes it.
// TODO: get notified from UDP part
<-time.After(5 * time.Minute)
return nil
}
func (this *SocksServer) handleSocks4(reader *v2io.BufferedReader, writer *v2io.BufferedWriter, auth protocol.Socks4AuthenticationRequest) error {
result := protocol.Socks4RequestGranted
if auth.Command == protocol.CmdBind {
result = protocol.Socks4RequestRejected
}
socks4Response := protocol.NewSocks4AuthenticationResponse(result, auth.Port, auth.IP[:])
socks4Response.Write(writer)
if result == protocol.Socks4RequestRejected {
log.Warning("Socks: Unsupported socks 4 command ", auth.Command)
return ErrorUnsupportedSocksCommand
}
reader.SetCached(false)
writer.SetCached(false)
dest := v2net.TCPDestination(v2net.IPAddress(auth.IP[:]), auth.Port)
packet := v2net.NewPacket(dest, nil, true)
this.transport(reader, writer, packet)
return nil
}
func (this *SocksServer) handleSocks5(reader *v2io.BufferedReader, writer *v2io.BufferedWriter, auth protocol.Socks5AuthenticationRequest) error {
expectedAuthMethod := protocol.AuthNotRequired
if this.config.AuthType == AuthTypePassword {
expectedAuthMethod = protocol.AuthUserPass
}
if !auth.HasAuthMethod(expectedAuthMethod) {
authResponse := protocol.NewAuthenticationResponse(protocol.AuthNoMatchingMethod)
err := protocol.WriteAuthentication(writer, authResponse)
writer.Flush()
if err != nil {
log.Error("Socks: failed to write authentication: ", err)
return err
}
log.Warning("Socks: client doesn't support any allowed auth methods.")
return ErrorUnsupportedAuthMethod
}
authResponse := protocol.NewAuthenticationResponse(expectedAuthMethod)
err := protocol.WriteAuthentication(writer, authResponse)
writer.Flush()
if err != nil {
log.Error("Socks: failed to write authentication: ", err)
return err
}
if this.config.AuthType == AuthTypePassword {
upRequest, err := protocol.ReadUserPassRequest(reader)
if err != nil {
log.Error("Socks: failed to read username and password: "******"Socks: failed to write user pass response: ", err)
return err
}
if status != byte(0) {
log.Warning("Socks: Invalid user account: ", upRequest.AuthDetail())
return proxy.ErrorInvalidAuthentication
}
}
request, err := protocol.ReadRequest(reader)
if err != nil {
log.Error("Socks: failed to read request: ", err)
return err
}
if request.Command == protocol.CmdUdpAssociate && this.config.UDPEnabled {
return this.handleUDP(reader, writer)
}
if request.Command == protocol.CmdBind || request.Command == protocol.CmdUdpAssociate {
response := protocol.NewSocks5Response()
response.Error = protocol.ErrorCommandNotSupported
response.Port = v2net.Port(0)
response.SetIPv4([]byte{0, 0, 0, 0})
response.Write(writer)
writer.Flush()
if err != nil {
log.Error("Socks: failed to write response: ", err)
return err
}
log.Warning("Socks: Unsupported socks command ", request.Command)
return ErrorUnsupportedSocksCommand
}
response := protocol.NewSocks5Response()
response.Error = protocol.ErrorSuccess
// Some SOCKS software requires a value other than dest. Let's fake one:
response.Port = v2net.Port(1717)
response.SetIPv4([]byte{0, 0, 0, 0})
response.Write(writer)
if err != nil {
log.Error("Socks: failed to write response: ", err)
return err
}
reader.SetCached(false)
writer.SetCached(false)
dest := request.Destination()
log.Info("Socks: TCP Connect request to ", dest)
packet := v2net.NewPacket(dest, nil, true)
this.transport(reader, writer, packet)
return nil
}