src/m_raw_channel.cc

   1 ///
   2 /// \file       m_raw_channel.cc
   3 ///             Mode class for a raw channel
   4 ///
   5
   6 /*
   7     Copyright (C) 2005-2012, Net Direct Inc. (http://www.netdirect.ca/)
   8     Portions Copyright (C) 2010 RealVNC Ltd.
   9
  10     This program is free software; you can redistribute it and/or modify
  11     it under the terms of the GNU General Public License as published by
  12     the Free Software Foundation; either version 2 of the License, or
  13     (at your option) any later version.
  14
  15     This program is distributed in the hope that it will be useful,
  16     but WITHOUT ANY WARRANTY; without even the implied warranty of
  17     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
  18
  19     See the GNU General Public License in the COPYING file at the
  20     root directory of this project for more details.
  21 */
  22
  23 #include "m_raw_channel.h"
  24 #include "semaphore.h"
  25 #include "data.h"
  26 #include "protocol.h"
  27 #include "protostructs.h"
  28 #include "packet.h"
  29 #include "endian.h"
  30 #include "error.h"
  31 #include "usbwrap.h"
  32 #include "controller.h"
  33 #include <stdexcept>
  34 #include <sstream>
  35 #include <cstring>
  36 #include <string>
  37 #include "protostructs.h"
  38
  39 #include "debug.h"
  40
  41 namespace Barry { namespace Mode {
  42
  43 ///////////////////////////////////////////////////////////////////////////////
  44 // RawChannel SocketDataHandler callback class for data socket
  45 class RawChannelSocketHandler: public SocketRoutingQueue::SocketDataHandler
  46 {
  47         RawChannel &m_raw_channel;
  48 public:
  49         RawChannelSocketHandler(RawChannel &raw_channel)
  50                 : m_raw_channel(raw_channel)
  51         {}
  52         virtual void DataReceived(Data &data)
  53         {
  54                 m_raw_channel.HandleReceivedData(data);
  55         }
  56         virtual void Error(Barry::Error &error)
  57         {
  58                 SocketDataHandler::Error(error);
  59                 m_raw_channel.HandleError(error);
  60         }
  61         virtual ~RawChannelSocketHandler()
  62         {}
  63 };
  64
  65 ///////////////////////////////////////////////////////////////////////////////
  66 // RawChannel SocketDataHandler callback class for zero socket
  67 class RawChannelZeroSocketHandler: public SocketRoutingQueue::SocketDataHandler
  68 {
  69         RawChannel &m_raw_channel;
  70 public:
  71         RawChannelZeroSocketHandler(RawChannel &raw_channel)
  72                 : m_raw_channel(raw_channel)
  73         {}
  74         virtual void DataReceived(Data &data)
  75         {
  76                 m_raw_channel.HandleReceivedZeroPacket(data);
  77         }
  78         virtual void Error(Barry::Error &error)
  79         {
  80                 SocketDataHandler::Error(error);
  81                 m_raw_channel.HandleError(error);
  82         }
  83         virtual ~RawChannelZeroSocketHandler()
  84         {}
  85 };
  86
  87 ///////////////////////////////////////////////////////////////////////////////
  88 // RawChannel Mode class
  89
  90 RawChannel::RawChannel(Controller &con, RawChannelDataCallback &callback)
  91         : Mode(con, Controller::RawChannel)
  92         , m_callback(&callback)
  93         , m_send_buffer(NULL)
  94         , m_zero_registered(false)
  95         , m_pending_error(NULL)
  96 {
  97         CheckQueueAvailable();
  98         InitBuffer();
  99 }
 100
 101 RawChannel::RawChannel(Controller &con)
 102         : Mode(con, Controller::RawChannel)
 103         , m_callback(NULL)
 104         , m_send_buffer(NULL)
 105         , m_zero_registered(false)
 106         , m_pending_error(NULL)
 107 {
 108         CheckQueueAvailable();
 109         InitBuffer();
 110 }
 111
 112 void RawChannel::CheckQueueAvailable()
 113 {
 114         if( !m_con.HasQueue() ) {
 115                 throw Barry::Error("RawChannel: No routing queue set in controller");
 116         }
 117 }
 118
 119 void RawChannel::InitBuffer()
 120 {
 121         m_send_buffer = new unsigned char[SB_CHANNELPACKET_HEADER_SIZE + SB_CHANNELPACKET_MAX_DATA_SIZE];
 122 }
 123
 124 RawChannel::~RawChannel()
 125 {
 126         UnregisterZeroSocketInterest();
 127
 128         delete[] m_send_buffer;
 129
 130         delete m_pending_error;
 131 }
 132
 133 void RawChannel::OnOpen()
 134 {
 135         // Enable sequence packets so that DataSendAck callback and close can be
 136         // implemented
 137         m_zero_registered = true;
 138         SocketRoutingQueue::SocketDataHandlerPtr zeroCallback;
 139         zeroCallback.reset(new RawChannelZeroSocketHandler(*this));
 140         m_con.GetQueue()->RegisterInterest(0, zeroCallback);
 141         // Get socket data packets routed to this class as well if a
 142         // callback was provided, otherside just get the data packets
 143         // placed into a queue for the socket.
 144         if( m_callback ) {
 145                 SocketRoutingQueue::SocketDataHandlerPtr callback;
 146                 callback.reset(new RawChannelSocketHandler(*this));
 147                 m_socket->UnregisterInterest();
 148                 m_socket->RegisterInterest(callback);
 149         }
 150         else {
 151                 // sockets already register themselves by default,
 152                 // so no need to do anything in this case
 153         }
 154 }
 155
 156
 157 void RawChannel::HandleReceivedZeroPacket(Data &data)
 158 {
 159         Protocol::CheckSize(data, SB_PACKET_HEADER_SIZE);
 160         MAKE_PACKETPTR_BUF(packet, data.GetData());
 161
 162         if( packet->socket != 0 ) {
 163                 UnregisterZeroSocketInterest();
 164                 SetPendingError("RawChannel: Got packet not for socket-zero");
 165         }
 166
 167         switch( btohs(packet->command) )
 168         {
 169         case SB_COMMAND_CLOSE_SOCKET:
 170         case SB_COMMAND_REMOTE_CLOSE_SOCKET:
 171                 // Stop listening to socket 0 messages
 172                 // so that socket close work.
 173                 UnregisterZeroSocketInterest();
 174                 if( m_callback ) {
 175                         m_callback->ChannelClose();
 176                 }
 177
 178                 break;
 179         default:
 180                 UnregisterZeroSocketInterest();
 181                 if( m_callback ) {
 182                         m_callback->ChannelError("RawChannel: Got unexpected socket zero packet");
 183                 }
 184                 else {
 185                         SetPendingError("RawChannel: Got unexpected socket zero packet");
 186                 }
 187                 break;
 188         }
 189
 190 }
 191
 192 void RawChannel::HandleReceivedData(Data &data)
 193 {
 194         // Only ever called in callback mode
 195         ValidateDataPacket(data);
 196         MAKE_CHANNELPACKETPTR_BUF(packet, data.GetData());
 197
 198         // Should be a socket packet for us, so remove packet headers
 199         Data partial(packet->u.data, data.GetSize() - SB_CHANNELPACKET_HEADER_SIZE);
 200         if( m_callback ) {
 201                 m_callback->DataReceived(partial);
 202         }
 203         else {
 204                 SetPendingError("RawChannel: Received data to handle when in non-callback mode");
 205         }
 206 }
 207
 208 void RawChannel::HandleError(Barry::Error &error)
 209 {
 210         std::ostringstream errorOss;
 211         errorOss << "RawChannel: Socket error received, what: " << error.what();
 212
 213         if( m_callback ) {
 214                 m_callback->ChannelError(errorOss.str().c_str());
 215         }
 216         else {
 217                 SetPendingError(errorOss.str().c_str());
 218         }
 219 }
 220
 221 void RawChannel::UnregisterZeroSocketInterest()
 222 {
 223         if( m_zero_registered ) {
 224                 m_con.GetQueue()->UnregisterInterest(0);
 225                 m_zero_registered = false;
 226         }
 227 }
 228
 229 void RawChannel::SetPendingError(const char *msg)
 230 {
 231         if( !m_pending_error ) {
 232                 m_pending_error = new std::string(msg);
 233         }
 234 }
 235
 236 ///////////////////////////////////////////////////////////////////////////////
 237 // public API
 238
 239 void RawChannel::Send(Data &data, int timeout)
 240 {
 241         size_t packetSize = SB_CHANNELPACKET_HEADER_SIZE + data.GetSize();
 242
 243         if( packetSize > SB_CHANNELPACKET_HEADER_SIZE + SB_CHANNELPACKET_MAX_DATA_SIZE ) {
 244                 throw Barry::Error("RawChannel: send data size larger than MaximumPacketSize");
 245         }
 246
 247         if( m_pending_error ) {
 248                 throw Barry::Error(*m_pending_error);
 249         }
 250
 251         // setup header and copy data in
 252         MAKE_CHANNELPACKETPTR_BUF(packet, m_send_buffer);
 253         packet->size = htobs(packetSize);
 254         std::memcpy(packet->u.data, data.GetData(), data.GetSize());
 255
 256         Data toSend(m_send_buffer, packetSize);
 257         m_socket->SyncSend(toSend, timeout);
 258
 259         if( m_pending_error ) {
 260                 throw Barry::Error(*m_pending_error);
 261         }
 262 }
 263
 264 void RawChannel::Receive(Data &data,int timeout)
 265 {
 266         if( m_callback ) {
 267                 throw std::logic_error("RawChannel: Receive called when channel was created with a callback");
 268         }
 269
 270         if( m_pending_error ) {
 271                 throw Barry::Error(*m_pending_error);
 272         }
 273
 274         // Receive into a buffer
 275         m_socket->Receive(m_receive_data, timeout);
 276         // Then transfer across, skipping the header
 277         ValidateDataPacket(m_receive_data);
 278         MAKE_CHANNELPACKETPTR_BUF(packet, m_receive_data.GetData());
 279
 280         size_t len = packet->size - SB_CHANNELPACKET_HEADER_SIZE;
 281         memcpy(data.GetBuffer(), packet->u.data, len);
 282         data.ReleaseBuffer(len);
 283
 284 }
 285
 286 void RawChannel::ValidateDataPacket(Data &data)
 287 {
 288         Protocol::CheckSize(data, SB_CHANNELPACKET_HEADER_SIZE);
 289         MAKE_CHANNELPACKETPTR_BUF(packet, data.GetData());
 290         if( packet->size != data.GetSize() ) {
 291
 292                 throw std::logic_error("RawChannel: Data size doesn't match packet size");
 293         }
 294 }
 295
 296 size_t RawChannel::MaximumSendSize()
 297 {
 298         return SB_CHANNELPACKET_MAX_DATA_SIZE;
 299 }
 300
 301 }} // namespace Barry::Mode