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
 168                                 // Check for duplicate server name/sid again, it's possible that a new
 169                                 // server was introduced while we were waiting for them to send BURST.
 170                                 // (we do not reserve their server name/sid when they send SERVER, we do it now)
 171                                 if (!CheckDuplicate(capab->name, capab->sid))
 172                                         return;
 173
 174                                 this->LinkState = CONNECTED;
 175                                 Utils->timeoutlist.erase(this);
 176
 177                                 linkID = capab->name;
 178
 179                                 MyRoot = new TreeServer(Utils, capab->name, capab->description, capab->sid, Utils->TreeRoot, this, capab->hidden);
 180                                 Utils->TreeRoot->AddChild(MyRoot);
 181
 182                                 MyRoot->bursting = true;
 183                                 this->DoBurst(MyRoot);
 184
 185                                 parameterlist sparams;
 186                                 sparams.push_back(MyRoot->GetName());
 187                                 sparams.push_back("*");
 188                                 sparams.push_back("0");
 189                                 sparams.push_back(MyRoot->GetID());
 190                                 sparams.push_back(":" + MyRoot->GetDesc());
 191                                 Utils->DoOneToAllButSender(ServerInstance->Config->GetSID(), "SERVER", sparams, MyRoot->GetName());
 192                                 Utils->DoOneToAllButSender(MyRoot->GetID(), "BURST", params, MyRoot->GetName());
 193                         }
 194                         else if (command == "ERROR")
 195                         {
 196                                 this->Error(params);
 197                         }
 198                         else if (command == "CAPAB")
 199                         {
 200                                 this->Capab(params);
 201                         }
 202
 203                 break;
 204                 case CONNECTING:
 205                         /*
 206                          * State CONNECTING:
 207                          *  We're connecting (OUTGOING) to another server. They are in state WAIT_AUTH_1 until they verify
 208                          *  our credentials, when they proceed into WAIT_AUTH_2 and send SERVER to us. We then send BURST
 209                          *  + our netburst, which will put them into CONNECTED state. -- w
 210                          */
 211                         if (command == "SERVER")
 212                         {
 213                                 // Our credentials have been accepted, send netburst. (this puts US into the CONNECTED state)
 214                                 this->Outbound_Reply_Server(params);
 215                         }
 216                         else if (command == "ERROR")
 217                         {
 218                                 this->Error(params);
 219                         }
 220                         else if (command == "CAPAB")
 221                         {
 222                                 this->Capab(params);
 223                         }
 224                 break;
 225                 case CONNECTED:
 226                         /*
 227                          * State CONNECTED:
 228                          *  Credentials have been exchanged, we've gotten their 'BURST' (or sent ours).
 229                          *  Anything from here on should be accepted a little more reasonably.
 230                          */
 231                         this->ProcessConnectedLine(prefix, command, params);
 232                 break;
 233                 case DYING:
 234                 break;
 235         }
 236 }
 237
 238 void TreeSocket::ProcessConnectedLine(std::string& prefix, std::string& command, parameterlist& params)
 239 {
 240         User* who = ServerInstance->FindUUID(prefix);
 241         std::string direction;
 242
 243         if (!who)
 244         {
 245                 TreeServer* ServerSource = Utils->FindServer(prefix);
 246                 if (prefix.empty())
 247                         ServerSource = MyRoot;
 248
 249                 if (ServerSource)
 250                 {
 251                         who = ServerSource->ServerUser;
 252                 }
 253                 else
 254                 {
 255                         /* It is important that we don't close the link here, unknown prefix can occur
 256                          * due to various race conditions such as the KILL message for a user somehow
 257                          * crossing the users QUIT further upstream from the server. Thanks jilles!
 258                          */
 259
 260                         if ((prefix.length() == UUID_LENGTH-1) && (isdigit(prefix[0])) &&
 261                                 ((command == "FMODE") || (command == "MODE") || (command == "KICK") || (command == "TOPIC") || (command == "KILL") || (command == "ADDLINE") || (command == "DELLINE")))
 262                         {
 263                                 /* Special case, we cannot drop these commands as they've been committed already on a
 264                                  * part of the network by the time we receive them, so in this scenario pretend the
 265                                  * command came from a server to avoid desync.
 266                                  */
 267
 268                                 who = ServerInstance->FindUUID(prefix.substr(0, 3));
 269                                 if (!who)
 270                                         who = this->MyRoot->ServerUser;
 271                         }
 272                         else
 273                         {
 274                                 ServerInstance->Logs->Log("m_spanningtree", DEBUG, "Command '%s' from unknown prefix '%s'! Dropping entire command.",
 275                                         command.c_str(), prefix.c_str());
 276                                 return;
 277                         }
 278                 }
 279         }
 280
 281         // Make sure prefix is still good
 282         direction = who->server;
 283         prefix = who->uuid;
 284
 285         /*
 286          * Check for fake direction here, and drop any instances that are found.
 287          * What is fake direction? Imagine the following server setup:
 288          *    0AA <-> 0AB <-> 0AC
 289          * Fake direction would be 0AC sending a message to 0AB claiming to be from
 290          * 0AA, or something similar. Basically, a message taking a path that *cannot*
 291          * be correct.
 292          *
 293          * When would this be seen?
 294          * Well, hopefully never. It could be caused by race conditions, bugs, or
 295          * "miscreant" servers, though, so let's check anyway. -- w
 296          *
 297          * We also check here for totally invalid prefixes (prefixes that are neither
 298          * a valid SID or a valid UUID, so that invalid UUID or SID never makes it
 299          * to the higher level functions. -- B
 300          */
 301         TreeServer* route_back_again = Utils->BestRouteTo(direction);
 302         if ((!route_back_again) || (route_back_again->GetSocket() != this))
 303         {
 304                 if (route_back_again)
 305                         ServerInstance->Logs->Log("m_spanningtree",DEBUG,"Protocol violation: Fake direction '%s' from connection '%s'",
 306                                 prefix.c_str(),linkID.c_str());
 307                 return;
 308         }
 309
 310         /*
 311          * First up, check for any malformed commands (e.g. MODE without a timestamp)
 312          * and rewrite commands where necessary (SVSMODE -> MODE for services). -- w
 313          */
 314         if (command == "SVSMODE") // This isn't in an "else if" so we still force FMODE for changes on channels.
 315                 command = "MODE";
 316
 317         // TODO move all this into Commands
 318         if (command == "MAP")
 319         {
 320                 Utils->Creator->HandleMap(params, who);
 321         }
 322         else if (command == "SERVER")
 323         {
 324                 this->RemoteServer(prefix,params);
 325         }
 326         else if (command == "ERROR")
 327         {
 328                 this->Error(params);
 329         }
 330         else if (command == "AWAY")
 331         {
 332                 this->Away(prefix,params);
 333         }
 334         else if (command == "PING")
 335         {
 336                 this->LocalPing(prefix,params);
 337         }
 338         else if (command == "PONG")
 339         {
 340                 TreeServer *s = Utils->FindServer(prefix);
 341                 if (s && s->bursting)
 342                 {
 343                         ServerInstance->SNO->WriteGlobalSno('l',"Server \002%s\002 has not finished burst, forcing end of burst (send ENDBURST!)", prefix.c_str());
 344                         s->FinishBurst();
 345                 }
 346                 this->LocalPong(prefix,params);
 347         }
 348         else if (command == "VERSION")
 349         {
 350                 this->ServerVersion(prefix,params);
 351         }
 352         else if (command == "ADDLINE")
 353         {
 354                 this->AddLine(prefix,params);
 355         }
 356         else if (command == "DELLINE")
 357         {
 358                 this->DelLine(prefix,params);
 359         }
 360         else if (command == "SAVE")
 361         {
 362                 this->ForceNick(prefix,params);
 363         }
 364         else if (command == "OPERQUIT")
 365         {
 366                 this->OperQuit(prefix,params);
 367         }
 368         else if (command == "IDLE")
 369         {
 370                 this->Whois(prefix,params);
 371         }
 372         else if (command == "PUSH")
 373         {
 374                 this->Push(prefix,params);
 375         }
 376         else if (command == "SQUIT")
 377         {
 378                 if (params.size() == 2)
 379                 {
 380                         this->Squit(Utils->FindServer(params[0]),params[1]);
 381                 }
 382         }
 383         else if (command == "SNONOTICE")
 384         {
 385                 if (params.size() >= 2)
 386                 {
 387                         ServerInstance->SNO->WriteToSnoMask(params[0][0], "From " + who->nick + ": "+ params[1]);
 388                         params[1] = ":" + params[1];
 389                         Utils->DoOneToAllButSender(prefix, command, params, prefix);
 390                 }
 391         }
 392         else if (command == "BURST")
 393         {
 394                 // Set prefix server as bursting
 395                 TreeServer* ServerSource = Utils->FindServer(prefix);
 396                 if (!ServerSource)
 397                 {
 398                         ServerInstance->SNO->WriteGlobalSno('l', "WTF: Got BURST from a non-server(?): %s", prefix.c_str());
 399                         return;
 400                 }
 401
 402                 ServerSource->bursting = true;
 403                 Utils->DoOneToAllButSender(prefix, command, params, prefix);
 404         }
 405         else if (command == "ENDBURST")
 406         {
 407                 TreeServer* ServerSource = Utils->FindServer(prefix);
 408                 if (!ServerSource)
 409                 {
 410                         ServerInstance->SNO->WriteGlobalSno('l', "WTF: Got ENDBURST from a non-server(?): %s", prefix.c_str());
 411                         return;
 412                 }
 413
 414                 ServerSource->FinishBurst();
 415                 Utils->DoOneToAllButSender(prefix, command, params, prefix);
 416         }
 417         else if (command == "ENCAP")
 418         {
 419                 this->Encap(who, params);
 420         }
 421         else if (command == "NICK")
 422         {
 423                 if (params.size() != 2)
 424                 {
 425                         SendError("Protocol violation: Wrong number of parameters for NICK message");
 426                         return;
 427                 }
 428
 429                 if (IS_SERVER(who))
 430                 {
 431                         SendError("Protocol violation: Server changing nick");
 432                         return;
 433                 }
 434
 435                 if ((isdigit(params[0][0])) && (params[0] != who->uuid))
 436                 {
 437                         SendError("Protocol violation: User changing nick to an invalid UID - " + params[0]);
 438                         return;
 439                 }
 440
 441                 /* Update timestamp on user when they change nicks */
 442                 who->age = atoi(params[1].c_str());
 443
 444                 /*
 445                  * On nick messages, check that the nick doesnt already exist here.
 446                  * If it does, perform collision logic.
 447                  */
 448                 bool callfnc = true;
 449                 User* x = ServerInstance->FindNickOnly(params[0]);
 450                 if ((x) && (x != who) && (x->registered == REG_ALL))
 451                 {
 452                         int collideret = 0;
 453                         /* x is local, who is remote */
 454                         collideret = this->DoCollision(x, who->age, who->ident, who->GetIPString(), who->uuid);
 455                         if (collideret != 1)
 456                         {
 457                                 // Remote client lost, or both lost, rewrite this nick change as a change to uuid before
 458                                 // forwarding and don't call ForceNickChange() because DoCollision() has done it already
 459                                 params[0] = who->uuid;
 460                                 callfnc = false;
 461                         }
 462                 }
 463                 if (callfnc)
 464                         who->ForceNickChange(params[0].c_str());
 465                 Utils->RouteCommand(route_back_again, command, params, who);
 466         }
 467         else
 468         {
 469                 Command* cmd = ServerInstance->Parser->GetHandler(command);
 470
 471                 if (!cmd)
 472                 {
 473                         irc::stringjoiner pmlist(" ", params, 0, params.size() - 1);
 474                         ServerInstance->Logs->Log("m_spanningtree", SPARSE, "Unrecognised S2S command :%s %s %s",
 475                                 who->uuid.c_str(), command.c_str(), pmlist.GetJoined().c_str());
 476                         SendError("Unrecognised command '" + command + "' -- possibly loaded mismatched modules");
 477                         return;
 478                 }
 479
 480                 if (params.size() < cmd->min_params)
 481                 {
 482                         irc::stringjoiner pmlist(" ", params, 0, params.size() - 1);
 483                         ServerInstance->Logs->Log("m_spanningtree", SPARSE, "Insufficient parameters for S2S command :%s %s %s",
 484                                 who->uuid.c_str(), command.c_str(), pmlist.GetJoined().c_str());
 485                         SendError("Insufficient parameters for command '" + command + "'");
 486                         return;
 487                 }
 488
 489                 if ((!params.empty()) && (params.back().empty()) && (!cmd->allow_empty_last_param))
 490                 {
 491                         // 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
 492                         if (params.size()-1 < cmd->min_params)
 493                                 return;
 494                         params.pop_back();
 495                 }
 496
 497                 CmdResult res = cmd->Handle(params, who);
 498
 499                 if (res == CMD_INVALID)
 500                 {
 501                         irc::stringjoiner pmlist(" ", params, 0, params.size() - 1);
 502                         ServerInstance->Logs->Log("m_spanningtree", SPARSE, "Error handling S2S command :%s %s %s",
 503                                 who->uuid.c_str(), command.c_str(), pmlist.GetJoined().c_str());
 504                         SendError("Error handling '" + command + "' -- possibly loaded mismatched modules");
 505                 }
 506                 else if (res == CMD_SUCCESS)
 507                         Utils->RouteCommand(route_back_again, command, params, who);
 508         }
 509 }
 510
 511 void TreeSocket::OnTimeout()
 512 {
 513         ServerInstance->SNO->WriteGlobalSno('l', "CONNECT: Connection to \002%s\002 timed out.", linkID.c_str());
 514 }
 515
 516 void TreeSocket::Close()
 517 {
 518         if (fd != -1)
 519                 ServerInstance->GlobalCulls.AddItem(this);
 520         this->BufferedSocket::Close();
 521         SetError("Remote host closed connection");
 522
 523         // Connection closed.
 524         // If the connection is fully up (state CONNECTED)
 525         // then propogate a netsplit to all peers.
 526         if (MyRoot)
 527                 Squit(MyRoot,getError());
 528
 529         if (!ConnectionFailureShown)
 530         {
 531                 ConnectionFailureShown = true;
 532                 ServerInstance->SNO->WriteGlobalSno('l', "Connection to '\2%s\2' failed.",linkID.c_str());
 533
 534                 time_t server_uptime = ServerInstance->Time() - this->age;
 535                 if (server_uptime)
 536                 {
 537                         std::string timestr = Utils->Creator->TimeToStr(server_uptime);
 538                         ServerInstance->SNO->WriteGlobalSno('l', "Connection to '\2%s\2' was established for %s", linkID.c_str(), timestr.c_str());
 539                 }
 540         }
 541 }