コード例 #1
0
        public int Read(ref ArraySegment <byte> buffer, ref int offset)
        {
            if (buffer.Count - offset == 0)
            {
                return(SocketOperation.None);
            }

            Debug.Assert(offset == 0);
            Debug.Assert(_fd != null);

            int packetSize = Math.Min(MaxPacketSize, _rcvSize - UdpOverhead);

            Debug.Assert(buffer.Count == 0);
            buffer = new byte[packetSize];

            int ret;

            while (true)
            {
                try
                {
                    EndPoint?peerAddr = _peerAddr;
                    if (peerAddr == null)
                    {
                        if (_addr.AddressFamily == AddressFamily.InterNetwork)
                        {
                            peerAddr = new IPEndPoint(IPAddress.Any, 0);
                        }
                        else
                        {
                            Debug.Assert(_addr.AddressFamily == AddressFamily.InterNetworkV6);
                            peerAddr = new IPEndPoint(IPAddress.IPv6Any, 0);
                        }
                    }

                    // TODO: Workaround for https://github.com/dotnet/corefx/issues/31182
                    if (_state == StateConnected ||
                        (AssemblyUtil.IsMacOS && _fd.AddressFamily == AddressFamily.InterNetworkV6 && _fd.DualMode))
                    {
                        ret = _fd.Receive(buffer.Array, 0, packetSize, SocketFlags.None);
                    }
                    else
                    {
                        ret       = _fd.ReceiveFrom(buffer.Array, 0, packetSize, SocketFlags.None, ref peerAddr);
                        _peerAddr = (IPEndPoint)peerAddr;
                    }
                    break;
                }
                catch (System.Net.Sockets.SocketException e)
                {
                    if (Network.RecvTruncated(e))
                    {
                        // The message was truncated and the whole buffer is filled. We ignore
                        // this error here, it will be detected at the connection level when
                        // the Ice message size is checked against the buffer size.
                        ret = buffer.Count;
                        break;
                    }

                    if (Network.Interrupted(e))
                    {
                        continue;
                    }

                    if (Network.WouldBlock(e))
                    {
                        return(SocketOperation.Read);
                    }

                    if (Network.ConnectionLost(e))
                    {
                        throw new Ice.ConnectionLostException();
                    }
                    else
                    {
                        throw new Ice.TransportException(e);
                    }
                }
            }

            if (ret == 0)
            {
                throw new ConnectionLostException();
            }

            if (_state == StateNeedConnect)
            {
                Debug.Assert(_incoming);

                //
                // If we must connect, then we connect to the first peer that sends us a packet.
                //
                Debug.Assert(_peerAddr != null);
                bool connected = Network.DoConnect(_fd, _peerAddr, null);
                Debug.Assert(connected);
                _state = StateConnected; // We're connected now

                if (_instance.TraceLevel >= 1)
                {
                    _instance.Logger.Trace(_instance.TraceCategory, $"connected {Transport()} socket\n{this}");
                }
            }

            buffer = buffer.Slice(0, ret);
            offset = ret;
            return(SocketOperation.None);
        }