src/modules/m_spanningtree/treesocket2.cpp

   1 /*
   2  * InspIRCd -- Internet Relay Chat Daemon
   3  *
   4  *   Copyright (C) 2007-2008, 2012 Robin Burchell <robin+git@viroteck.net>
   5  *   Copyright (C) 2009-2010 Daniel De Graaf <danieldg@inspircd.org>
   6  *   Copyright (C) 2007-2008 Craig Edwards <craigedwards@brainbox.cc>
   7  *   Copyright (C) 2008 Pippijn van Steenhoven <pip88nl@gmail.com>
   8  *   Copyright (C) 2008 Thomas Stagner <aquanight@inspircd.org>
   9  *   Copyright (C) 2007 Dennis Friis <peavey@inspircd.org>
  10  *
  11  * This file is part of InspIRCd.  InspIRCd is free software: you can
  12  * redistribute it and/or modify it under the terms of the GNU General Public
  13  * License as published by the Free Software Foundation, version 2.
  14  *
  15  * This program is distributed in the hope that it will be useful, but WITHOUT
  16  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
  17  * FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more
  18  * details.
  19  *
  20  * You should have received a copy of the GNU General Public License
  21  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  22  */
  23
  24
  25 #include "inspircd.h"
  26
  27 #include "main.h"
  28 #include "utils.h"
  29 #include "treeserver.h"
  30 #include "treesocket.h"
  31 #include "resolvers.h"
  32
  33 /* Handle ERROR command */
  34 void TreeSocket::Error(parameterlist &params)
  35 {
  36         std::string msg = params.size() ? params[0] : "";
  37         SetError("received ERROR " + msg);
  38 }
  39
  40 void TreeSocket::Split(const std::string& line, std::string& prefix, std::string& command, parameterlist& params)
  41 {
  42         irc::tokenstream tokens(line);
  43
  44         if (!tokens.GetToken(prefix))
  45                 return;
  46
  47         if (prefix[0] == ':')
  48         {
  49                 prefix = prefix.substr(1);
  50
  51                 if (prefix.empty())
  52                 {
  53                         this->SendError("BUG (?) Empty prefix received: " + line);
  54                         return;
  55                 }
  56                 if (!tokens.GetToken(command))
  57                 {
  58                         this->SendError("BUG (?) Empty command received: " + line);
  59                         return;
  60                 }
  61         }
  62         else
  63         {
  64                 command = prefix;
  65                 prefix.clear();
  66         }
  67         if (command.empty())
  68                 this->SendError("BUG (?) Empty command received: " + line);
  69
  70         std::string param;
  71         while (tokens.GetToken(param))
  72         {
  73                 params.push_back(param);
  74         }
  75 }
  76
  77 void TreeSocket::ProcessLine(std::string &line)
  78 {
  79         std::string prefix;
  80         std::string command;
  81         parameterlist params;
  82
  83         ServerInstance->Logs->Log("m_spanningtree", LOG_RAWIO, "S[%d] I %s", this->GetFd(), line.c_str());
  84
  85         Split(line, prefix, command, params);
  86
  87         if (command.empty())
  88                 return;
  89
  90         switch (this->LinkState)
  91         {
  92                 case WAIT_AUTH_1:
  93                         /*
  94                          * State WAIT_AUTH_1:
  95                          *  Waiting for SERVER command from remote server. Server initiating
  96                          *  the connection sends the first SERVER command, listening server
  97                          *  replies with theirs if its happy, then if the initiator is happy,
  98                          *  it starts to send its net sync, which starts the merge, otherwise
  99                          *  it sends an ERROR.
 100                          */
 101                         if (command == "PASS")
 102                         {
 103                                 /*
 104                                  * Ignore this silently. Some services packages insist on sending PASS, even
 105                                  * when it is not required (i.e. by us). We have to ignore this here, otherwise
 106                                  * as it's an unknown command (effectively), it will cause the connection to be
 107                                  * closed, which probably isn't what people want. -- w00t
 108                                  */
 109                         }
 110                         else if (command == "SERVER")
 111                         {
 112                                 this->Inbound_Server(params);
 113                         }
 114                         else if (command == "ERROR")
 115                         {
 116                                 this->Error(params);
 117                         }
 118                         else if (command == "USER")
 119                         {
 120                                 this->SendError("Client connections to this port are prohibited.");
 121                         }
 122                         else if (command == "CAPAB")
 123                         {
 124                                 this->Capab(params);
 125                         }
 126                         else
 127                         {
 128                                 this->SendError("Invalid command in negotiation phase: " + command);
 129                         }
 130                 break;
 131                 case WAIT_AUTH_2:
 132                         /*
 133                          * State WAIT_AUTH_2:
 134                          *  We have sent SERVER to the other side of the connection. Now we're waiting for them to start BURST.
 135                          *  The other option at this stage of things, of course, is for them to close our connection thanks
 136                          *  to invalid credentials.. -- w
 137                          */
 138                         if (command == "SERVER")
 139                         {
 140                                 /*
 141                                  * Connection is either attempting to re-auth itself (stupid) or sending netburst without sending BURST.
 142                                  * Both of these aren't allowable, so block them here. -- w
 143                                  */
 144                                 this->SendError("You may not re-authenticate or commence netburst without sending BURST.");
 145                         }
 146                         else if (command == "BURST")
 147                         {
 148                                 if (params.size())
 149                                 {
 150                                         time_t them = ConvToInt(params[0]);
 151                                         time_t delta = them - ServerInstance->Time();
 152                                         if ((delta < -600) || (delta > 600))
 153                                         {
 154                                                 ServerInstance->SNO->WriteGlobalSno('l',"\2ERROR\2: Your clocks are out by %d seconds (this is more than five minutes). Link aborted, \2PLEASE SYNC YOUR CLOCKS!\2",abs((long)delta));
 155                                                 SendError("Your clocks are out by "+ConvToStr(abs((long)delta))+" seconds (this is more than five minutes). Link aborted, PLEASE SYNC YOUR CLOCKS!");
 156                                                 return;
 157                                         }
 158                                         else if ((delta < -30) || (delta > 30))
 159                                         {
 160                                                 ServerInstance->SNO->WriteGlobalSno('l',"\2WARNING\2: Your clocks are out by %d seconds. Please consider synching your clocks.", abs((long)delta));
 161                                         }
 162                                 }
 163                                 this->LinkState = CONNECTED;
 164                                 Utils->timeoutlist.erase(this);
 165
 166                                 MyRoot->bursting = true;
 167                                 this->DoBurst(MyRoot);
 168
 169                                 parameterlist sparams;
 170                                 sparams.push_back(MyRoot->GetName());
 171                                 sparams.push_back("*");
 172                                 sparams.push_back("0");
 173                                 sparams.push_back(MyRoot->GetID());
 174                                 sparams.push_back(":" + MyRoot->GetDesc());
 175                                 Utils->DoOneToAllButSender(ServerInstance->Config->GetSID(), "SERVER", sparams, MyRoot->GetName());
 176                                 Utils->DoOneToAllButSender(MyRoot->GetID(), "BURST", params, MyRoot->GetName());
 177                         }
 178                         else if (command == "ERROR")
 179                         {
 180                                 this->Error(params);
 181                         }
 182                         else if (command == "CAPAB")
 183                         {
 184                                 this->Capab(params);
 185                         }
 186
 187                 break;
 188                 case CONNECTING:
 189                         /*
 190                          * State CONNECTING:
 191                          *  We're connecting (OUTGOING) to another server. They are in state WAIT_AUTH_1 until they verify
 192                          *  our credentials, when they proceed into WAIT_AUTH_2 and send SERVER to us. We then send BURST
 193                          *  + our netburst, which will put them into CONNECTED state. -- w
 194                          */
 195                         if (command == "SERVER")
 196                         {
 197                                 // Our credentials have been accepted, send netburst. (this puts US into the CONNECTED state)
 198                                 this->Outbound_Reply_Server(params);
 199                         }
 200                         else if (command == "ERROR")
 201                         {
 202                                 this->Error(params);
 203                         }
 204                         else if (command == "CAPAB")
 205                         {
 206                                 this->Capab(params);
 207                         }
 208                 break;
 209                 case CONNECTED:
 210                         /*
 211                          * State CONNECTED:
 212                          *  Credentials have been exchanged, we've gotten their 'BURST' (or sent ours).
 213                          *  Anything from here on should be accepted a little more reasonably.
 214                          */
 215                         this->ProcessConnectedLine(prefix, command, params);
 216                 break;
 217                 case DYING:
 218                 break;
 219         }
 220 }
 221
 222 void TreeSocket::ProcessConnectedLine(std::string& prefix, std::string& command, parameterlist& params)
 223 {
 224         User* who = ServerInstance->FindUUID(prefix);
 225         std::string direction;
 226
 227         if (!who)
 228         {
 229                 TreeServer* ServerSource = Utils->FindServer(prefix);
 230                 if (prefix.empty())
 231                         ServerSource = MyRoot;
 232
 233                 if (ServerSource)
 234                 {
 235                         who = ServerSource->ServerUser;
 236                 }
 237                 else
 238                 {
 239                         /* It is important that we don't close the link here, unknown prefix can occur
 240                          * due to various race conditions such as the KILL message for a user somehow
 241                          * crossing the users QUIT further upstream from the server. Thanks jilles!
 242                          */
 243
 244                         if ((prefix.length() == UIDGenerator::UUID_LENGTH) && (isdigit(prefix[0])) &&
 245                                 ((command == "FMODE") || (command == "MODE") || (command == "KICK") || (command == "TOPIC") || (command == "KILL") || (command == "ADDLINE") || (command == "DELLINE")))
 246                         {
 247                                 /* Special case, we cannot drop these commands as they've been committed already on a
 248                                  * part of the network by the time we receive them, so in this scenario pretend the
 249                                  * command came from a server to avoid desync.
 250                                  */
 251
 252                                 who = ServerInstance->FindUUID(prefix.substr(0, 3));
 253                                 if (!who)
 254                                         who = this->MyRoot->ServerUser;
 255                         }
 256                         else
 257                         {
 258                                 ServerInstance->Logs->Log("m_spanningtree", LOG_DEBUG, "Command '%s' from unknown prefix '%s'! Dropping entire command.",
 259                                         command.c_str(), prefix.c_str());
 260                                 return;
 261                         }
 262                 }
 263         }
 264
 265         // Make sure prefix is still good
 266         direction = who->server;
 267         prefix = who->uuid;
 268
 269         /*
 270          * Check for fake direction here, and drop any instances that are found.
 271          * What is fake direction? Imagine the following server setup:
 272          *    0AA <-> 0AB <-> 0AC
 273          * Fake direction would be 0AC sending a message to 0AB claiming to be from
 274          * 0AA, or something similar. Basically, a message taking a path that *cannot*
 275          * be correct.
 276          *
 277          * When would this be seen?
 278          * Well, hopefully never. It could be caused by race conditions, bugs, or
 279          * "miscreant" servers, though, so let's check anyway. -- w
 280          *
 281          * We also check here for totally invalid prefixes (prefixes that are neither
 282          * a valid SID or a valid UUID, so that invalid UUID or SID never makes it
 283          * to the higher level functions. -- B
 284          */
 285         TreeServer* route_back_again = Utils->BestRouteTo(direction);
 286         if ((!route_back_again) || (route_back_again->GetSocket() != this))
 287         {
 288                 if (route_back_again)
 289                         ServerInstance->Logs->Log("m_spanningtree",LOG_DEBUG,"Protocol violation: Fake direction '%s' from connection '%s'",
 290                                 prefix.c_str(),linkID.c_str());
 291                 return;
 292         }
 293
 294         /*
 295          * First up, check for any malformed commands (e.g. MODE without a timestamp)
 296          * and rewrite commands where necessary (SVSMODE -> MODE for services). -- w
 297          */
 298         if (command == "SVSMODE") // This isn't in an "else if" so we still force FMODE for changes on channels.
 299                 command = "MODE";
 300
 301         if (proto_version < ProtocolVersion)
 302         {
 303                 if (!PreProcessOldProtocolMessage(who, command, params))
 304                         return;
 305         }
 306
 307         // TODO move all this into Commands
 308         if (command == "MAP")
 309         {
 310                 Utils->Creator->HandleMap(params, who);
 311         }
 312         else if (command == "SERVER")
 313         {
 314                 this->RemoteServer(prefix,params);
 315         }
 316         else if (command == "ERROR")
 317         {
 318                 this->Error(params);
 319         }
 320         else if (command == "AWAY")
 321         {
 322                 this->Away(prefix,params);
 323         }
 324         else if (command == "PING")
 325         {
 326                 this->LocalPing(prefix,params);
 327         }
 328         else if (command == "PONG")
 329         {
 330                 TreeServer *s = Utils->FindServer(prefix);
 331                 if (s && s->bursting)
 332                 {
 333                         ServerInstance->SNO->WriteGlobalSno('l',"Server \002%s\002 has not finished burst, forcing end of burst (send ENDBURST!)", prefix.c_str());
 334                         s->FinishBurst();
 335                 }
 336                 this->LocalPong(prefix,params);
 337         }
 338         else if (command == "VERSION")
 339         {
 340                 this->ServerVersion(prefix,params);
 341         }
 342         else if (command == "ADDLINE")
 343         {
 344                 this->AddLine(prefix,params);
 345         }
 346         else if (command == "DELLINE")
 347         {
 348                 this->DelLine(prefix,params);
 349         }
 350         else if (command == "SAVE")
 351         {
 352                 this->ForceNick(prefix,params);
 353         }
 354         else if (command == "OPERQUIT")
 355         {
 356                 this->OperQuit(prefix,params);
 357         }
 358         else if (command == "IDLE")
 359         {
 360                 this->Whois(prefix,params);
 361         }
 362         else if (command == "PUSH")
 363         {
 364                 this->Push(prefix,params);
 365         }
 366         else if (command == "SQUIT")
 367         {
 368                 if (params.size() == 2)
 369                 {
 370                         this->Squit(Utils->FindServer(params[0]),params[1]);
 371                 }
 372         }
 373         else if (command == "SNONOTICE")
 374         {
 375                 if (params.size() >= 2)
 376                 {
 377                         ServerInstance->SNO->WriteToSnoMask(params[0][0], "From " + who->nick + ": "+ params[1]);
 378                         params[1] = ":" + params[1];
 379                         Utils->DoOneToAllButSender(prefix, command, params, prefix);
 380                 }
 381         }
 382         else if (command == "BURST")
 383         {
 384                 // Set prefix server as bursting
 385                 TreeServer* ServerSource = Utils->FindServer(prefix);
 386                 if (!ServerSource)
 387                 {
 388                         ServerInstance->SNO->WriteGlobalSno('l', "WTF: Got BURST from a non-server(?): %s", prefix.c_str());
 389                         return;
 390                 }
 391
 392                 ServerSource->bursting = true;
 393                 Utils->DoOneToAllButSender(prefix, command, params, prefix);
 394         }
 395         else if (command == "ENDBURST")
 396         {
 397                 TreeServer* ServerSource = Utils->FindServer(prefix);
 398                 if (!ServerSource)
 399                 {
 400                         ServerInstance->SNO->WriteGlobalSno('l', "WTF: Got ENDBURST from a non-server(?): %s", prefix.c_str());
 401                         return;
 402                 }
 403
 404                 ServerSource->FinishBurst();
 405                 Utils->DoOneToAllButSender(prefix, command, params, prefix);
 406         }
 407         else if (command == "ENCAP")
 408         {
 409                 this->Encap(who, params);
 410         }
 411         else if (command == "NICK")
 412         {
 413                 if (params.size() != 2)
 414                 {
 415                         SendError("Protocol violation: Wrong number of parameters for NICK message");
 416                         return;
 417                 }
 418
 419                 if (IS_SERVER(who))
 420                 {
 421                         SendError("Protocol violation: Server changing nick");
 422                         return;
 423                 }
 424
 425                 if ((isdigit(params[0][0])) && (params[0] != who->uuid))
 426                 {
 427                         SendError("Protocol violation: User changing nick to an invalid UID - " + params[0]);
 428                         return;
 429                 }
 430
 431                 /* Update timestamp on user when they change nicks */
 432                 who->age = ConvToInt(params[1]);
 433
 434                 /*
 435                  * On nick messages, check that the nick doesnt already exist here.
 436                  * If it does, perform collision logic.
 437                  */
 438                 User* x = ServerInstance->FindNickOnly(params[0]);
 439                 if ((x) && (x != who))
 440                 {
 441                         int collideret = 0;
 442                         /* x is local, who is remote */
 443                         collideret = this->DoCollision(x, who->age, who->ident, who->GetIPString(), who->uuid);
 444                         if (collideret != 1)
 445                         {
 446                                 /*
 447                                  * Remote client lost, or both lost, parsing or passing on this
 448                                  * nickchange would be pointless, as the incoming client's server will
 449                                  * soon recieve SVSNICK to change its nick to its UID. :) -- w00t
 450                                  */
 451                                 return;
 452                         }
 453                 }
 454                 who->ForceNickChange(params[0].c_str());
 455                 Utils->RouteCommand(route_back_again, command, params, who);
 456         }
 457         else
 458         {
 459                 Command* cmd = ServerInstance->Parser->GetHandler(command);
 460
 461                 if (!cmd)
 462                 {
 463                         irc::stringjoiner pmlist(" ", params, 0, params.size() - 1);
 464                         ServerInstance->Logs->Log("m_spanningtree", LOG_SPARSE, "Unrecognised S2S command :%s %s %s",
 465                                 who->uuid.c_str(), command.c_str(), pmlist.GetJoined().c_str());
 466                         SendError("Unrecognised command '" + command + "' -- possibly loaded mismatched modules");
 467                         return;
 468                 }
 469
 470                 if (params.size() < cmd->min_params)
 471                 {
 472                         irc::stringjoiner pmlist(" ", params, 0, params.size() - 1);
 473                         ServerInstance->Logs->Log("m_spanningtree", LOG_SPARSE, "Insufficient parameters for S2S command :%s %s %s",
 474                                 who->uuid.c_str(), command.c_str(), pmlist.GetJoined().c_str());
 475                         SendError("Insufficient parameters for command '" + command + "'");
 476                         return;
 477                 }
 478
 479                 if ((!params.empty()) && (params.back().empty()) && (!cmd->allow_empty_last_param))
 480                 {
 481                         // the last param is empty and the command handler doesn't allow that, check if there will be enough params if we drop the last
 482                         if (params.size()-1 < cmd->min_params)
 483                                 return;
 484                         params.pop_back();
 485                 }
 486
 487                 CmdResult res = cmd->Handle(params, who);
 488
 489                 if (res == CMD_INVALID)
 490                 {
 491                         irc::stringjoiner pmlist(" ", params, 0, params.size() - 1);
 492                         ServerInstance->Logs->Log("m_spanningtree", LOG_SPARSE, "Error handling S2S command :%s %s %s",
 493                                 who->uuid.c_str(), command.c_str(), pmlist.GetJoined().c_str());
 494                         SendError("Error handling '" + command + "' -- possibly loaded mismatched modules");
 495                 }
 496                 else if (res == CMD_SUCCESS)
 497                         Utils->RouteCommand(route_back_again, command, params, who);
 498         }
 499 }
 500
 501 void TreeSocket::OnTimeout()
 502 {
 503         ServerInstance->SNO->WriteGlobalSno('l', "CONNECT: Connection to \002%s\002 timed out.", linkID.c_str());
 504 }
 505
 506 void TreeSocket::Close()
 507 {
 508         if (fd != -1)
 509                 ServerInstance->GlobalCulls.AddItem(this);
 510         this->BufferedSocket::Close();
 511         SetError("Remote host closed connection");
 512
 513         // Connection closed.
 514         // If the connection is fully up (state CONNECTED)
 515         // then propogate a netsplit to all peers.
 516         if (MyRoot)
 517                 Squit(MyRoot,getError());
 518
 519         if (!ConnectionFailureShown)
 520         {
 521                 ConnectionFailureShown = true;
 522                 ServerInstance->SNO->WriteGlobalSno('l', "Connection to '\2%s\2' failed.",linkID.c_str());
 523
 524                 time_t server_uptime = ServerInstance->Time() - this->age;
 525                 if (server_uptime)
 526                 {
 527                         std::string timestr = Utils->Creator->TimeToStr(server_uptime);
 528                         ServerInstance->SNO->WriteGlobalSno('l', "Connection to '\2%s\2' was established for %s", linkID.c_str(), timestr.c_str());
 529                 }
 530         }
 531 }