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