src/Packet.cpp

   1 //
   2 // This file is part of the aMule Project.
   3 //
   4 // Copyright (c) 2003-2008 aMule Team ( admin@amule.org / http://www.amule.org )
   5 // Copyright (c) 2002-2008 Merkur ( devs@emule-project.net / http://www.emule-project.net )
   6 //
   7 // Any parts of this program derived from the xMule, lMule or eMule project,
   8 // or contributed by third-party developers are copyrighted by their
   9 // respective authors.
  10 //
  11 // This program is free software; you can redistribute it and/or modify
  12 // it under the terms of the GNU General Public License as published by
  13 // the Free Software Foundation; either version 2 of the License, or
  14 // (at your option) any later version.
  15 //
  16 // This program is distributed in the hope that it will be useful,
  17 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  18 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19 // GNU General Public License for more details.
  20 //
  21 // You should have received a copy of the GNU General Public License
  22 // along with this program; if not, write to the Free Software
  23 // Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301, USA
  24 //
  25
  26 #include <zlib.h>               // Needed for uLongf
  27
  28 #include "Packet.h"                             // Interface declarations
  29
  30 #include <protocol/Protocols.h>
  31
  32 #include "MemFile.h"                    // Needed for CMemFile
  33 #include "OtherStructs.h"               // Needed for Header_Struct
  34 #include "ArchSpecific.h"               // Needed for ENDIAN_*
  35
  36 // Copy constructor
  37 CPacket::CPacket(CPacket &p)
  38 {
  39         size            = p.size;
  40         opcode          = p.opcode;
  41         prot            = p.prot;
  42         m_bSplitted     = p.m_bSplitted;
  43         m_bLastSplitted = p.m_bLastSplitted;
  44         m_bPacked       = p.m_bPacked;
  45         m_bFromPF       = p.m_bFromPF;
  46         memcpy(head, p.head, sizeof head);
  47         tempbuffer      = NULL;
  48         if (p.completebuffer) {
  49                 completebuffer  = new byte[size + 10];;
  50                 pBuffer         = completebuffer + sizeof(Header_Struct);
  51         } else {
  52                 completebuffer  = NULL;
  53                 if (p.pBuffer) {
  54                         pBuffer = new byte[size];
  55                 } else {
  56                         pBuffer = NULL;
  57                 }
  58         }
  59         if (pBuffer)
  60                 memcpy( pBuffer, p.pBuffer, size );
  61 }
  62
  63 CPacket::CPacket(uint8 protocol)
  64 {
  65         size            = 0;
  66         opcode          = 0;
  67         prot            = protocol;
  68         m_bSplitted     = false;
  69         m_bLastSplitted = false;
  70         m_bPacked       = false;
  71         m_bFromPF       = false;
  72         memset(head, 0, sizeof head);
  73         tempbuffer      = NULL;
  74         completebuffer  = NULL;
  75         pBuffer         = NULL;
  76 }
  77
  78 // only used for receiving packets
  79 CPacket::CPacket(byte* rawHeader)
  80 {
  81         memset(head, 0, sizeof head);
  82         Header_Struct* header = (Header_Struct*)rawHeader;
  83         size            = ENDIAN_SWAP_32(header->packetlength) - 1;
  84         opcode          = header->command;
  85         prot            = header->eDonkeyID;
  86         m_bSplitted     = false;
  87         m_bLastSplitted = false;
  88         m_bPacked       = false;
  89         m_bFromPF       = false;
  90         tempbuffer      = NULL;
  91         completebuffer  = NULL;
  92         pBuffer         = NULL;
  93 }
  94
  95 CPacket::CPacket(const CMemFile& datafile, uint8 protocol, uint8 ucOpcode)
  96 {
  97         size            = datafile.GetLength();
  98         opcode          = ucOpcode;
  99         prot            = protocol;
 100         m_bSplitted     = false;
 101         m_bLastSplitted = false;
 102         m_bPacked       = false;
 103         m_bFromPF       = false;
 104         memset(head, 0, sizeof head);
 105         tempbuffer = NULL;
 106         completebuffer = new byte[size + sizeof(Header_Struct)/*Why this 4?*/];
 107         pBuffer = completebuffer + sizeof(Header_Struct);
 108
 109         // Write contents of MemFile to buffer (while keeping original position in file)
 110         off_t position = datafile.GetPosition();
 111         datafile.Seek(0, wxFromStart);
 112         datafile.Read(pBuffer, size);
 113         datafile.Seek(position, wxFromStart);
 114 }
 115
 116 CPacket::CPacket(int8 in_opcode, uint32 in_size, uint8 protocol, bool bFromPF)
 117 {
 118         size            = in_size;
 119         opcode          = in_opcode;
 120         prot            = protocol;
 121         m_bSplitted     = false;
 122         m_bLastSplitted = false;
 123         m_bPacked       = false;
 124         m_bFromPF       = bFromPF;
 125         memset(head, 0, sizeof head);
 126         tempbuffer      = NULL;
 127         if (in_size) {
 128                 completebuffer = new byte[in_size + sizeof(Header_Struct) + 4 /*Why this 4?*/];
 129                 pBuffer = completebuffer + sizeof(Header_Struct);
 130                 memset(completebuffer, 0, in_size + sizeof(Header_Struct) + 4 /*Why this 4?*/);
 131         } else {
 132                 completebuffer = NULL;
 133                 pBuffer = NULL;
 134         }
 135 }
 136
 137 // only used for splitted packets!
 138 CPacket::CPacket(byte* pPacketPart, uint32 nSize, bool bLast, bool bFromPF)
 139 {
 140         size            = nSize - sizeof(Header_Struct);
 141         opcode          = 0;
 142         prot            = 0;
 143         m_bSplitted     = true;
 144         m_bLastSplitted = bLast;
 145         m_bPacked       = false;
 146         m_bFromPF       = bFromPF;
 147         memset(head, 0, sizeof head);
 148         tempbuffer      = NULL;
 149         completebuffer  = pPacketPart;
 150         pBuffer         = NULL;
 151 }
 152
 153 CPacket::~CPacket()
 154 {
 155         // Never deletes pBuffer when completebuffer is not NULL
 156         if (completebuffer) {
 157                 delete [] completebuffer;
 158         } else if (pBuffer) {
 159         // On the other hand, if completebuffer is NULL and pBuffer is not NULL
 160                 delete [] pBuffer;
 161         }
 162
 163         if (tempbuffer) {
 164                 delete [] tempbuffer;
 165         }
 166 }
 167
 168 void CPacket::AllocDataBuffer(void)
 169 {
 170         wxASSERT(completebuffer == NULL);
 171         pBuffer = new byte[size + 1];
 172 }
 173
 174 void CPacket::CopyToDataBuffer(unsigned int offset, const byte* data, unsigned int n)
 175 {
 176         wxASSERT(offset + n <= size + 1);
 177         memcpy(pBuffer + offset, data, n);
 178 }
 179
 180 byte* CPacket::GetPacket() {
 181         if (completebuffer) {
 182                 if (!m_bSplitted) {
 183                         memcpy(completebuffer, GetHeader(), sizeof(Header_Struct));
 184                 }
 185                 return completebuffer;
 186         } else {
 187                 if (tempbuffer){
 188                         delete [] tempbuffer;
 189                         tempbuffer = NULL;
 190                 }
 191                 tempbuffer = new byte[size + sizeof(Header_Struct) + 4 /* why this 4?*/];
 192                 memcpy(tempbuffer    , GetHeader(), sizeof(Header_Struct));
 193                 memcpy(tempbuffer + sizeof(Header_Struct), pBuffer    , size);
 194                 return tempbuffer;
 195         }
 196 }
 197
 198 byte* CPacket::DetachPacket() {
 199         if (completebuffer) {
 200                 if (!m_bSplitted) {
 201                         memcpy(completebuffer, GetHeader(), sizeof(Header_Struct));
 202                 }
 203                 byte* result = completebuffer;
 204                 completebuffer = pBuffer = NULL;
 205                 return result;
 206         } else{
 207                 if (tempbuffer){
 208                         delete[] tempbuffer;
 209                         tempbuffer = NULL;
 210                 }
 211                 tempbuffer = new byte[size+sizeof(Header_Struct)+4 /* Why this 4?*/];
 212                 memcpy(tempbuffer,GetHeader(),sizeof(Header_Struct));
 213                 memcpy(tempbuffer+sizeof(Header_Struct),pBuffer,size);
 214                 byte* result = tempbuffer;
 215                 tempbuffer = 0;
 216                 return result;
 217         }
 218 }
 219
 220 byte* CPacket::GetHeader() {
 221         wxASSERT( !m_bSplitted );
 222
 223         Header_Struct* header = (Header_Struct*) head;
 224         header->command = opcode;
 225         header->eDonkeyID =  prot;
 226         header->packetlength = ENDIAN_SWAP_32(size + 1);
 227
 228         return head;
 229 }
 230
 231 byte* CPacket::GetUDPHeader() {
 232         wxASSERT( !m_bSplitted );
 233
 234         memset(head, 0, 6);
 235         UDP_Header_Struct* header = (UDP_Header_Struct*) head;
 236         header->eDonkeyID =  prot;
 237         header->command = opcode;
 238
 239         return head;
 240 }
 241
 242
 243 void CPacket::PackPacket()
 244 {
 245         wxASSERT(!m_bSplitted);
 246
 247         uLongf newsize = size + 300;
 248         byte* output = new byte[newsize];
 249
 250         uint16 result = compress2(output, &newsize, pBuffer, size, Z_BEST_COMPRESSION);
 251
 252         if (result != Z_OK || size <= newsize) {
 253                 delete[] output;
 254                 return;
 255         }
 256
 257         if (prot == OP_KADEMLIAHEADER) {
 258                 prot = OP_KADEMLIAPACKEDPROT;
 259         } else {
 260                 prot = OP_PACKEDPROT;
 261         }
 262
 263         memcpy(pBuffer, output, newsize);
 264         delete[] output;
 265         m_bPacked = true;
 266
 267         size = newsize;
 268 }
 269
 270
 271 bool CPacket::UnPackPacket(uint32 uMaxDecompressedSize) {
 272         wxASSERT( prot == OP_PACKEDPROT );
 273
 274         uint32 nNewSize = size * 10 + 300;
 275
 276         if (nNewSize > uMaxDecompressedSize){
 277                 nNewSize = uMaxDecompressedSize;
 278         }
 279
 280         byte* unpack = new byte[nNewSize];
 281         uLongf unpackedsize = nNewSize;
 282         uint16 result = uncompress(unpack, &unpackedsize, pBuffer, size);
 283
 284         if (result == Z_OK) {
 285                 wxASSERT( completebuffer == NULL );
 286                 wxASSERT( pBuffer != NULL );
 287
 288                 size = unpackedsize;
 289                 delete[] pBuffer;
 290                 pBuffer = unpack;
 291                 prot = OP_EMULEPROT;
 292                 return true;
 293         }
 294
 295         delete[] unpack;
 296         return false;
 297 }
 298
 299
 300 void CPacket::Copy16ToDataBuffer(const void* data)
 301 {
 302         md4cpy(pBuffer, data);
 303 }
 304
 305
 306 void CPacket::CopyUInt32ToDataBuffer(uint32 data, unsigned int offset)
 307 {
 308         wxCHECK_RET(offset <= size - sizeof(uint32), wxT("Bad offset in CopyUInt32ToDataBuffer."));
 309         PokeUInt32( pBuffer + offset, data );
 310 }
 311 // File_checked_for_headers