136 lines
3.1 KiB
Go
136 lines
3.1 KiB
Go
// Copyright (C) 2015 Audrius Butkevicius and Contributors (see the CONTRIBUTORS file).
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package protocol
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import (
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"errors"
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"fmt"
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"io"
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)
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const (
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magic = 0x9E79BC40
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ProtocolName = "bep-relay"
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)
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var (
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ResponseSuccess = Response{0, "success"}
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ResponseNotFound = Response{1, "not found"}
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ResponseAlreadyConnected = Response{2, "already connected"}
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ResponseUnexpectedMessage = Response{100, "unexpected message"}
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)
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func WriteMessage(w io.Writer, message interface{}) error {
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header := header{
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magic: magic,
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}
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var payload []byte
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var err error
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switch msg := message.(type) {
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case Ping:
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payload, err = msg.MarshalXDR()
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header.messageType = messageTypePing
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case Pong:
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payload, err = msg.MarshalXDR()
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header.messageType = messageTypePong
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case JoinRelayRequest:
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payload, err = msg.MarshalXDR()
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header.messageType = messageTypeJoinRelayRequest
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case JoinSessionRequest:
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payload, err = msg.MarshalXDR()
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header.messageType = messageTypeJoinSessionRequest
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case Response:
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payload, err = msg.MarshalXDR()
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header.messageType = messageTypeResponse
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case ConnectRequest:
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payload, err = msg.MarshalXDR()
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header.messageType = messageTypeConnectRequest
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case SessionInvitation:
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payload, err = msg.MarshalXDR()
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header.messageType = messageTypeSessionInvitation
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case RelayFull:
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payload, err = msg.MarshalXDR()
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header.messageType = messageTypeRelayFull
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default:
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err = errors.New("unknown message type")
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}
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if err != nil {
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return err
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}
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header.messageLength = int32(len(payload))
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headerpayload, err := header.MarshalXDR()
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if err != nil {
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return err
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}
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_, err = w.Write(append(headerpayload, payload...))
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return err
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}
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func ReadMessage(r io.Reader) (interface{}, error) {
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var header header
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buf := make([]byte, header.XDRSize())
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if _, err := io.ReadFull(r, buf); err != nil {
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return nil, err
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}
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if err := header.UnmarshalXDR(buf); err != nil {
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return nil, err
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}
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if header.magic != magic {
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return nil, errors.New("magic mismatch")
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}
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if header.messageLength < 0 || header.messageLength > 1024 {
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return nil, fmt.Errorf("bad length (%d)", header.messageLength)
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}
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buf = make([]byte, int(header.messageLength))
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if _, err := io.ReadFull(r, buf); err != nil {
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return nil, err
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}
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switch header.messageType {
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case messageTypePing:
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var msg Ping
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err := msg.UnmarshalXDR(buf)
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return msg, err
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case messageTypePong:
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var msg Pong
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err := msg.UnmarshalXDR(buf)
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return msg, err
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case messageTypeJoinRelayRequest:
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var msg JoinRelayRequest
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err := msg.UnmarshalXDR(buf)
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return msg, err
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case messageTypeJoinSessionRequest:
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var msg JoinSessionRequest
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err := msg.UnmarshalXDR(buf)
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return msg, err
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case messageTypeResponse:
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var msg Response
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err := msg.UnmarshalXDR(buf)
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return msg, err
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case messageTypeConnectRequest:
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var msg ConnectRequest
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err := msg.UnmarshalXDR(buf)
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return msg, err
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case messageTypeSessionInvitation:
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var msg SessionInvitation
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err := msg.UnmarshalXDR(buf)
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return msg, err
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case messageTypeRelayFull:
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var msg RelayFull
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err := msg.UnmarshalXDR(buf)
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return msg, err
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}
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return nil, errors.New("unknown message type")
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}
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