package shadowsocks import ( "bytes" "io" "v2ray.com/core/common/alloc" "v2ray.com/core/common/log" v2net "v2ray.com/core/common/net" "v2ray.com/core/proxy" "v2ray.com/core/transport" ) const ( AddrTypeIPv4 = 1 AddrTypeIPv6 = 4 AddrTypeDomain = 3 ) type Request struct { Address v2net.Address Port v2net.Port OTA bool UDPPayload *alloc.Buffer } func (this *Request) Release() { this.Address = nil if this.UDPPayload != nil { this.UDPPayload.Release() } } func (this *Request) DetachUDPPayload() *alloc.Buffer { payload := this.UDPPayload this.UDPPayload = nil return payload } func ReadRequest(reader io.Reader, auth *Authenticator, udp bool) (*Request, error) { buffer := alloc.NewSmallBuffer() defer buffer.Release() _, err := io.ReadFull(reader, buffer.Value[:1]) if err != nil { if err != io.EOF { log.Warning("Shadowsocks: Failed to read address type: ", err) return nil, transport.ErrCorruptedPacket } return nil, err } lenBuffer := 1 request := new(Request) addrType := (buffer.Value[0] & 0x0F) if (buffer.Value[0] & 0x10) == 0x10 { request.OTA = true } switch addrType { case AddrTypeIPv4: _, err := io.ReadFull(reader, buffer.Value[lenBuffer:lenBuffer+4]) if err != nil { log.Warning("Shadowsocks: Failed to read IPv4 address: ", err) return nil, transport.ErrCorruptedPacket } request.Address = v2net.IPAddress(buffer.Value[lenBuffer : lenBuffer+4]) lenBuffer += 4 case AddrTypeIPv6: _, err := io.ReadFull(reader, buffer.Value[lenBuffer:lenBuffer+16]) if err != nil { log.Warning("Shadowsocks: Failed to read IPv6 address: ", err) return nil, transport.ErrCorruptedPacket } request.Address = v2net.IPAddress(buffer.Value[lenBuffer : lenBuffer+16]) lenBuffer += 16 case AddrTypeDomain: _, err := io.ReadFull(reader, buffer.Value[lenBuffer:lenBuffer+1]) if err != nil { log.Warning("Shadowsocks: Failed to read domain lenth: ", err) return nil, transport.ErrCorruptedPacket } domainLength := int(buffer.Value[lenBuffer]) lenBuffer++ _, err = io.ReadFull(reader, buffer.Value[lenBuffer:lenBuffer+domainLength]) if err != nil { log.Warning("Shadowsocks: Failed to read domain: ", err) return nil, transport.ErrCorruptedPacket } request.Address = v2net.DomainAddress(string(buffer.Value[lenBuffer : lenBuffer+domainLength])) lenBuffer += domainLength default: log.Warning("Shadowsocks: Unknown address type: ", addrType) return nil, transport.ErrCorruptedPacket } _, err = io.ReadFull(reader, buffer.Value[lenBuffer:lenBuffer+2]) if err != nil { log.Warning("Shadowsocks: Failed to read port: ", err) return nil, transport.ErrCorruptedPacket } request.Port = v2net.PortFromBytes(buffer.Value[lenBuffer : lenBuffer+2]) lenBuffer += 2 var authBytes []byte if udp { nBytes, err := reader.Read(buffer.Value[lenBuffer:]) if err != nil { log.Warning("Shadowsocks: Failed to read UDP payload: ", err) return nil, transport.ErrCorruptedPacket } buffer.Slice(0, lenBuffer+nBytes) if request.OTA { authBytes = buffer.Value[lenBuffer+nBytes-AuthSize:] request.UDPPayload = alloc.NewSmallBuffer().Clear().Append(buffer.Value[lenBuffer : lenBuffer+nBytes-AuthSize]) lenBuffer = lenBuffer + nBytes - AuthSize } else { request.UDPPayload = alloc.NewSmallBuffer().Clear().Append(buffer.Value[lenBuffer:]) } } else { if request.OTA { authBytes = buffer.Value[lenBuffer : lenBuffer+AuthSize] _, err = io.ReadFull(reader, authBytes) if err != nil { log.Warning("Shadowsocks: Failed to read OTA: ", err) return nil, transport.ErrCorruptedPacket } } } if request.OTA { actualAuth := auth.Authenticate(nil, buffer.Value[0:lenBuffer]) if !bytes.Equal(actualAuth, authBytes) { log.Warning("Shadowsocks: Invalid OTA.") return nil, proxy.ErrInvalidAuthentication } } return request, nil }