src/ClientUDPSocket.cpp

   1 //
   2 // This file is part of the aMule Project.
   3 //
   4 // Copyright (c) 2003-2011 aMule Team ( admin@amule.org / http://www.amule.org )
   5 // Copyright (c) 2002-2011 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
  27 #include "ClientUDPSocket.h"    // Interface declarations
  28
  29 #include <protocol/Protocols.h>
  30 #include <protocol/ed2k/Client2Client/TCP.h> // Sometimes we reply with TCP packets.
  31 #include <protocol/ed2k/Client2Client/UDP.h>
  32 #include <protocol/kad2/Client2Client/UDP.h>
  33 #include <common/EventIDs.h>
  34 #include <common/Format.h>      // Needed for CFormat
  35
  36 #include "Preferences.h"                // Needed for CPreferences
  37 #include "PartFile.h"                   // Needed for CPartFile
  38 #include "updownclient.h"               // Needed for CUpDownClient
  39 #include "UploadQueue.h"                // Needed for CUploadQueue
  40 #include "Packet.h"                             // Needed for CPacket
  41 #include "SharedFileList.h"             // Needed for CSharedFileList
  42 #include "DownloadQueue.h"              // Needed for CDownloadQueue
  43 #include "Statistics.h"                 // Needed for theStats
  44 #include "amule.h"                              // Needed for theApp
  45 #include "ClientList.h"                 // Needed for clientlist (buddy support)
  46 #include "ClientTCPSocket.h"    // Needed for CClientTCPSocket
  47 #include "MemFile.h"                    // Needed for CMemFile
  48 #include "Logger.h"
  49 #include "kademlia/kademlia/Kademlia.h"
  50 #include "kademlia/utils/KadUDPKey.h"
  51 #include <zlib.h>
  52 #include "EncryptedDatagramSocket.h"
  53
  54 //
  55 // CClientUDPSocket -- Extended eMule UDP socket
  56 //
  57
  58 CClientUDPSocket::CClientUDPSocket(const amuleIPV4Address& address, const CProxyData* ProxyData)
  59         : CMuleUDPSocket(wxT("Client UDP-Socket"), ID_CLIENTUDPSOCKET_EVENT, address, ProxyData)
  60 {
  61         if (!thePrefs::IsUDPDisabled()) {
  62                 Open();
  63         }
  64 }
  65
  66
  67 void CClientUDPSocket::OnReceive(int errorCode)
  68 {
  69         CMuleUDPSocket::OnReceive(errorCode);
  70
  71         // TODO: A better solution is needed.
  72         if (thePrefs::IsUDPDisabled()) {
  73                 Close();
  74         }
  75 }
  76
  77
  78 void CClientUDPSocket::OnPacketReceived(uint32 ip, uint16 port, byte* buffer, size_t length)
  79 {
  80         wxCHECK_RET(length >= 2, wxT("Invalid packet."));
  81
  82         uint8_t *decryptedBuffer;
  83         uint32_t receiverVerifyKey;
  84         uint32_t senderVerifyKey;
  85         int packetLen = CEncryptedDatagramSocket::DecryptReceivedClient(buffer, length, &decryptedBuffer, ip, &receiverVerifyKey, &senderVerifyKey);
  86
  87         uint8_t protocol = decryptedBuffer[0];
  88         uint8_t opcode   = decryptedBuffer[1];
  89
  90         if (packetLen >= 1) {
  91                 try {
  92                         switch (protocol) {
  93                                 case OP_EMULEPROT:
  94                                         ProcessPacket(decryptedBuffer + 2, packetLen - 2, opcode, ip, port);
  95                                         break;
  96
  97                                 case OP_KADEMLIAHEADER:
  98                                         theStats::AddDownOverheadKad(length);
  99                                         if (packetLen >= 2) {
 100                                                 Kademlia::CKademlia::ProcessPacket(decryptedBuffer, packetLen, wxUINT32_SWAP_ALWAYS(ip), port, (Kademlia::CPrefs::GetUDPVerifyKey(ip) == receiverVerifyKey), Kademlia::CKadUDPKey(senderVerifyKey, theApp->GetPublicIP(false)));
 101                                         } else {
 102                                                 throw wxString(wxT("Kad packet too short"));
 103                                         }
 104                                         break;
 105
 106                                 case OP_KADEMLIAPACKEDPROT:
 107                                         theStats::AddDownOverheadKad(length);
 108                                         if (packetLen >= 2) {
 109                                                 uint32_t newSize = packetLen * 10 + 300; // Should be enough...
 110                                                 std::vector<uint8_t> unpack(newSize);
 111                                                 uLongf unpackedsize = newSize - 2;
 112                                                 uint16_t result = uncompress(&(unpack[2]), &unpackedsize, decryptedBuffer + 2, packetLen - 2);
 113                                                 if (result == Z_OK) {
 114                                                         AddDebugLogLineN(logClientKadUDP, wxT("Correctly uncompressed Kademlia packet"));
 115                                                         unpack[0] = OP_KADEMLIAHEADER;
 116                                                         unpack[1] = opcode;
 117                                                         Kademlia::CKademlia::ProcessPacket(&(unpack[0]), unpackedsize + 2, wxUINT32_SWAP_ALWAYS(ip), port, (Kademlia::CPrefs::GetUDPVerifyKey(ip) == receiverVerifyKey), Kademlia::CKadUDPKey(senderVerifyKey, theApp->GetPublicIP(false)));
 118                                                 } else {
 119                                                         AddDebugLogLineN(logClientKadUDP, wxT("Failed to uncompress Kademlia packet"));
 120                                                 }
 121                                         } else {
 122                                                 throw wxString(wxT("Kad packet (compressed) too short"));
 123                                         }
 124                                         break;
 125
 126                                 default:
 127                                         AddDebugLogLineN(logClientUDP, CFormat(wxT("Unknown opcode on received packet: 0x%x")) % protocol);
 128                         }
 129                 } catch (const wxString& DEBUG_ONLY(e)) {
 130                         AddDebugLogLineN(logClientUDP, wxT("Error while parsing UDP packet: ") + e);
 131                 } catch (const CInvalidPacket& DEBUG_ONLY(e)) {
 132                         AddDebugLogLineN(logClientUDP, wxT("Invalid UDP packet encountered: ") + e.what());
 133                 } catch (const CEOFException& DEBUG_ONLY(e)) {
 134                         AddDebugLogLineN(logClientUDP, wxT("Malformed packet encountered while parsing UDP packet: ") + e.what());
 135                 }
 136         }
 137 }
 138
 139
 140 void CClientUDPSocket::ProcessPacket(byte* packet, int16 size, int8 opcode, uint32 host, uint16 port)
 141 {
 142         switch (opcode) {
 143                 case OP_REASKCALLBACKUDP: {
 144                         AddDebugLogLineN( logClientUDP, wxT("Client UDP socket; OP_REASKCALLBACKUDP") );
 145                         theStats::AddDownOverheadOther(size);
 146                         CUpDownClient* buddy = theApp->clientlist->GetBuddy();
 147                         if( buddy ) {
 148                                 if( size < 17 || buddy->GetSocket() == NULL ) {
 149                                         break;
 150                                 }
 151                                 if (!md4cmp(packet, buddy->GetBuddyID())) {
 152                                         /*
 153                                                 The packet has an initial 16 bytes key for the buddy.
 154                                                 This is currently unused, so to make the transformation
 155                                                 we discard the first 10 bytes below and then overwrite
 156                                                 the other 6 with ip/port.
 157                                         */
 158                                         CMemFile mem_packet(packet+10,size-10);
 159                                         // Change the ip and port while leaving the rest untouched
 160                                         mem_packet.Seek(0,wxFromStart);
 161                                         mem_packet.WriteUInt32(host);
 162                                         mem_packet.WriteUInt16(port);
 163                                         CPacket* response = new CPacket(mem_packet, OP_EMULEPROT, OP_REASKCALLBACKTCP);
 164                                         AddDebugLogLineN( logClientUDP, wxT("Client UDP socket: send OP_REASKCALLBACKTCP") );
 165                                         theStats::AddUpOverheadFileRequest(response->GetPacketSize());
 166                                         buddy->GetSocket()->SendPacket(response);
 167                                 }
 168                         }
 169                         break;
 170                 }
 171                 case OP_REASKFILEPING: {
 172                         AddDebugLogLineN( logClientUDP, wxT("Client UDP socket: OP_REASKFILEPING") );
 173                         theStats::AddDownOverheadFileRequest(size);
 174
 175                         CMemFile data_in(packet, size);
 176                         CMD4Hash reqfilehash = data_in.ReadHash();
 177                         CKnownFile* reqfile = theApp->sharedfiles->GetFileByID(reqfilehash);
 178                         bool bSenderMultipleIpUnknown = false;
 179                         CUpDownClient* sender = theApp->uploadqueue->GetWaitingClientByIP_UDP(host, port, true, &bSenderMultipleIpUnknown);
 180
 181                         if (!reqfile) {
 182                                 CPacket* response = new CPacket(OP_FILENOTFOUND,0,OP_EMULEPROT);
 183                                 theStats::AddUpOverheadFileRequest(response->GetPacketSize());
 184                                 if (sender) {
 185                                         SendPacket(response, host, port, sender->ShouldReceiveCryptUDPPackets(), sender->GetUserHash().GetHash(), false, 0);
 186                                 } else {
 187                                         SendPacket(response, host, port, false, NULL, false, 0);
 188                                 }
 189
 190                                 break;
 191                         }
 192
 193                         if (sender){
 194                                 sender->CheckForAggressive();
 195
 196                                 //Make sure we are still thinking about the same file
 197                                 if (reqfilehash == sender->GetUploadFileID()) {
 198                                         sender->AddAskedCount();
 199                                         sender->SetUDPPort(port);
 200                                         sender->SetLastUpRequest();
 201
 202                                         if (sender->GetUDPVersion() > 3) {
 203                                                 sender->ProcessExtendedInfo(&data_in, reqfile);
 204                                         } else  if (sender->GetUDPVersion() > 2) {
 205                                                 uint16 nCompleteCountLast = sender->GetUpCompleteSourcesCount();
 206                                                 uint16 nCompleteCountNew = data_in.ReadUInt16();
 207                                                 sender->SetUpCompleteSourcesCount(nCompleteCountNew);
 208                                                 if (nCompleteCountLast != nCompleteCountNew) {
 209                                                         reqfile->UpdatePartsInfo();
 210                                                 }
 211                                         }
 212
 213                                         CMemFile data_out(128);
 214                                         if(sender->GetUDPVersion() > 3) {
 215                                                 if (reqfile->IsPartFile()) {
 216                                                         static_cast<CPartFile*>(reqfile)->WritePartStatus(&data_out);
 217                                                 } else {
 218                                                         data_out.WriteUInt16(0);
 219                                                 }
 220                                         }
 221
 222                                         data_out.WriteUInt16(sender->GetUploadQueueWaitingPosition());
 223                                         CPacket* response = new CPacket(data_out, OP_EMULEPROT, OP_REASKACK);
 224                                         theStats::AddUpOverheadFileRequest(response->GetPacketSize());
 225                                         AddDebugLogLineN( logClientUDP, wxT("Client UDP socket: OP_REASKACK to ") + sender->GetFullIP());
 226                                         SendPacket(response, host, port, sender->ShouldReceiveCryptUDPPackets(), sender->GetUserHash().GetHash(), false, 0);
 227                                 } else {
 228                                         AddDebugLogLineN( logClientUDP, wxT("Client UDP socket; ReaskFilePing; reqfile does not match") );
 229                                 }
 230                         } else {
 231                                 if (!bSenderMultipleIpUnknown) {
 232                                         if ((theStats::GetWaitingUserCount() + 50) > thePrefs::GetQueueSize()) {
 233                                                 CPacket* response = new CPacket(OP_QUEUEFULL,0,OP_EMULEPROT);
 234                                                 theStats::AddUpOverheadFileRequest(response->GetPacketSize());
 235                                                 SendPacket(response,host,port, false, NULL, false, 0); // we cannot answer this one encrypted since we dont know this client
 236                                         }
 237                                 } else {
 238                                         AddDebugLogLineN(logClientUDP, CFormat(wxT("UDP Packet received - multiple clients with the same IP but different UDP port found. Possible UDP Portmapping problem, enforcing TCP connection. IP: %s, Port: %u")) % Uint32toStringIP(host) % port);
 239                                 }
 240                         }
 241                         break;
 242                 }
 243                 case OP_QUEUEFULL: {
 244                         AddDebugLogLineN( logClientUDP, wxT("Client UDP socket: OP_QUEUEFULL") );
 245                         theStats::AddDownOverheadOther(size);
 246                         CUpDownClient* sender = theApp->downloadqueue->GetDownloadClientByIP_UDP(host,port);
 247                         if (sender) {
 248                                 sender->SetRemoteQueueFull(true);
 249                                 sender->UDPReaskACK(0);
 250                         }
 251                         break;
 252                 }
 253                 case OP_REASKACK: {
 254                         theStats::AddDownOverheadFileRequest(size);
 255                         CUpDownClient* sender = theApp->downloadqueue->GetDownloadClientByIP_UDP(host,port);
 256                         if (sender) {
 257                                 CMemFile data_in(packet,size);
 258                                 if ( sender->GetUDPVersion() > 3 ) {
 259                                         sender->ProcessFileStatus(true, &data_in, sender->GetRequestFile());
 260                                 }
 261                                 uint16 nRank = data_in.ReadUInt16();
 262                                 sender->SetRemoteQueueFull(false);
 263                                 sender->UDPReaskACK(nRank);
 264                         }
 265                         break;
 266                 }
 267                 case OP_FILENOTFOUND: {
 268                         AddDebugLogLineN( logClientUDP, wxT("Client UDP socket: OP_FILENOTFOUND") );
 269                         theStats::AddDownOverheadFileRequest(size);
 270                         CUpDownClient* sender = theApp->downloadqueue->GetDownloadClientByIP_UDP(host,port);
 271                         if (sender){
 272                                 sender->UDPReaskFNF(); // may delete 'sender'!
 273                                 sender = NULL;
 274                         }
 275                         break;
 276                 }
 277                 case OP_DIRECTCALLBACKREQ:
 278                 {
 279                         AddDebugLogLineN( logClientUDP, wxT("Client UDP socket: OP_DIRECTCALLBACKREQ") );
 280                         theStats::AddDownOverheadOther(size);
 281                         if (!theApp->clientlist->AllowCallbackRequest(host)) {
 282                                 AddDebugLogLineN(logClientUDP, wxT("Ignored DirectCallback Request because this IP (") + Uint32toStringIP(host) + wxT(") has sent too many requests within a short time"));
 283                                 break;
 284                         }
 285                         // do we accept callbackrequests at all?
 286                         if (Kademlia::CKademlia::IsRunning() && Kademlia::CKademlia::IsFirewalled()) {
 287                                 theApp->clientlist->AddTrackCallbackRequests(host);
 288                                 CMemFile data(packet, size);
 289                                 uint16_t remoteTCPPort = data.ReadUInt16();
 290                                 CMD4Hash userHash(data.ReadHash());
 291                                 uint8_t connectOptions = data.ReadUInt8();
 292                                 CUpDownClient* requester = NULL;
 293                                 CClientList::SourceList clients = theApp->clientlist->GetClientsByHash(userHash);
 294                                 for (CClientList::SourceList::iterator it = clients.begin(); it != clients.end(); ++it) {
 295                                         if ((host == 0 || it->GetIP() == host) && (remoteTCPPort == 0 || it->GetUserPort() == remoteTCPPort)) {
 296                                                 requester = it->GetClient();
 297                                                 break;
 298                                         }
 299                                 }
 300                                 if (requester == NULL) {
 301                                         requester = new CUpDownClient(remoteTCPPort, host, 0, 0, NULL, true, true);
 302                                         requester->SetUserHash(CMD4Hash(userHash));
 303                                         theApp->clientlist->AddClient(requester);
 304                                 }
 305                                 requester->SetConnectOptions(connectOptions, true, false);
 306                                 requester->SetDirectUDPCallbackSupport(false);
 307                                 requester->SetIP(host);
 308                                 requester->SetUserPort(remoteTCPPort);
 309                                 AddDebugLogLineN(logClientUDP, wxT("Accepting incoming DirectCallback Request from ") + Uint32toStringIP(host));
 310                                 requester->TryToConnect();
 311                         } else {
 312                                 AddDebugLogLineN(logClientUDP, wxT("Ignored DirectCallback Request because we do not accept Direct Callbacks at all (") + Uint32toStringIP(host) + wxT(")"));
 313                         }
 314                         break;
 315                 }
 316                 default:
 317                         theStats::AddDownOverheadOther(size);
 318         }
 319 }
 320 // File_checked_for_headers