src/protocol.cc

   1 ///
   2 /// \file       protocol.cc
   3 ///             USB Blackberry bulk protocol API
   4 ///
   5
   6 /*
   7     Copyright (C) 2005-2011, Net Direct Inc. (http://www.netdirect.ca/)
   8
   9     This program is free software; you can redistribute it and/or modify
  10     it under the terms of the GNU General Public License as published by
  11     the Free Software Foundation; either version 2 of the License, or
  12     (at your option) any later version.
  13
  14     This program is distributed in the hope that it will be useful,
  15     but WITHOUT ANY WARRANTY; without even the implied warranty of
  16     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
  17
  18     See the GNU General Public License in the COPYING file at the
  19     root directory of this project for more details.
  20 */
  21
  22 #include "protocol.h"
  23 #include "protostructs.h"
  24 #include "data.h"
  25 #include "endian.h"
  26 #include "error.h"
  27 #include "debug.h"
  28
  29 #include <sstream>
  30
  31 namespace Barry { namespace Protocol {
  32
  33 // This function is only valid for Packet, JLPacket, and JVMPacket structs,
  34 // as long as they don't differ from each other in header layout, when
  35 // it comes to the .size field.  (see protostructs.h)
  36 void CheckSize(const Data &packet, size_t requiredsize)
  37 {
  38         const Packet *p = (const Packet *) packet.GetData();
  39
  40         // when packets are larger than 0xFFFF bytes, packet->size is no
  41         // longer reliable, so we go with the Data class size
  42         if( (packet.GetSize() >= 4 && btohs(p->size) != packet.GetSize() && packet.GetSize() <= 0xFFFF) ||
  43             packet.GetSize() < requiredsize )
  44
  45         {
  46                 BadSize bs(packet.GetSize() >= 4 ? btohs(p->size) : 0,
  47                         packet.GetSize(), requiredsize);
  48                 eout(bs.what());
  49                 eout(packet);
  50                 throw bs;
  51         }
  52 }
  53
  54 unsigned int GetSize(const Data &packet)
  55 {
  56         CheckSize(packet, 4);
  57
  58         // when packets are larger than 0xFFFF bytes, packet->size is no
  59         // longer reliable, so we go with the Data class size
  60         if( packet.GetSize() > 0xFFFF ) {
  61                 return packet.GetSize();
  62         }
  63         else {
  64                 const Packet *p = (const Packet *) packet.GetData();
  65                 return btohs(p->size);
  66         }
  67 }
  68
  69 bool IsSequencePacket(const Barry::Data &data)
  70 {
  71         if( data.GetSize() == SB_SEQUENCE_PACKET_SIZE ) {
  72                 MAKE_PACKET(rpack, data);
  73                 if( rpack->socket == 0 &&
  74                     rpack->command == SB_COMMAND_SEQUENCE_HANDSHAKE )
  75                 {
  76                         return true;
  77                 }
  78         }
  79         return false;   // not a sequence packet
  80 }
  81
  82 }} // namespace Barry::Protocol
  83