src/modules/m_spanningtree/treesocket2.cpp

   1 /*       +------------------------------------+
   2  *       | Inspire Internet Relay Chat Daemon |
   3  *       +------------------------------------+
   4  *
   5  *  InspIRCd: (C) 2002-2008 InspIRCd Development Team
   6  * See: http://www.inspircd.org/wiki/index.php/Credits
   7  *
   8  * This program is free but copyrighted software; see
   9  *            the file COPYING for details.
  10  *
  11  * ---------------------------------------------------
  12  */
  13
  14 #include "inspircd.h"
  15 #include "commands/cmd_whois.h"
  16 #include "commands/cmd_stats.h"
  17 #include "socket.h"
  18 #include "wildcard.h"
  19 #include "xline.h"
  20 #include "transport.h"
  21 #include "socketengine.h"
  22
  23 #include "m_spanningtree/main.h"
  24 #include "m_spanningtree/utils.h"
  25 #include "m_spanningtree/treeserver.h"
  26 #include "m_spanningtree/link.h"
  27 #include "m_spanningtree/treesocket.h"
  28 #include "m_spanningtree/resolvers.h"
  29 #include "m_spanningtree/handshaketimer.h"
  30
  31 /* $ModDep: m_spanningtree/timesynctimer.h m_spanningtree/resolvers.h m_spanningtree/main.h m_spanningtree/utils.h m_spanningtree/treeserver.h m_spanningtree/link.h m_spanningtree/treesocket.h */
  32
  33 static std::map<std::string, std::string> warned;       /* Server names that have had protocol violation warnings displayed for them */
  34
  35 int TreeSocket::WriteLine(std::string line)
  36 {
  37         Instance->Log(DEBUG, "S[%d] O %s", this->GetFd(), line.c_str());
  38         line.append("\r\n");
  39         return this->Write(line);
  40 }
  41
  42
  43 /* Handle ERROR command */
  44 bool TreeSocket::Error(std::deque<std::string> &params)
  45 {
  46         if (params.size() < 1)
  47                 return false;
  48         this->Instance->SNO->WriteToSnoMask('l',"ERROR from %s: %s",(!InboundServerName.empty() ? InboundServerName.c_str() : myhost.c_str()),params[0].c_str());
  49         /* we will return false to cause the socket to close. */
  50         return false;
  51 }
  52
  53 /** TODO: This creates a total mess of output and needs to really use irc::modestacker.
  54  */
  55 bool TreeSocket::RemoveStatus(const std::string &prefix, std::deque<std::string> &params)
  56 {
  57         if (params.size() < 1)
  58                 return true;
  59         Channel* c = Instance->FindChan(params[0]);
  60         if (c)
  61         {
  62                 for (char modeletter = 'A'; modeletter <= 'z'; modeletter++)
  63                 {
  64                         ModeHandler* mh = Instance->Modes->FindMode(modeletter, MODETYPE_CHANNEL);
  65                         if (mh)
  66                                 mh->RemoveMode(c);
  67                 }
  68         }
  69         return true;
  70 }
  71
  72 bool TreeSocket::RemoteServer(const std::string &prefix, std::deque<std::string> &params)
  73 {
  74         if (params.size() < 5)
  75         {
  76                 SendError("Protocol error - Missing SID");
  77                 return false;
  78         }
  79
  80         std::string servername = params[0];
  81         std::string password = params[1];
  82         // hopcount is not used for a remote server, we calculate this ourselves
  83         std::string sid = params[3];
  84         std::string description = params[4];
  85         TreeServer* ParentOfThis = Utils->FindServer(prefix);
  86         if (!ParentOfThis)
  87         {
  88                 this->SendError("Protocol error - Introduced remote server from unknown server "+prefix);
  89                 return false;
  90         }
  91         if (!this->Instance->IsSID(sid))
  92         {
  93                 this->SendError("Invalid format server ID: "+sid+"!");
  94                 return false;
  95         }
  96         TreeServer* CheckDupe = Utils->FindServer(servername);
  97         if (CheckDupe)
  98         {
  99                 this->SendError("Server "+servername+" already exists!");
 100                 this->Instance->SNO->WriteToSnoMask('l',"Server \2"+servername+"\2 being introduced from \2" + prefix + "\2 denied, already exists. Closing link with " + prefix);
 101                 return false;
 102         }
 103
 104         Link* lnk = Utils->FindLink(servername);
 105
 106         TreeServer *Node = new TreeServer(this->Utils, this->Instance, servername, description, sid, ParentOfThis,NULL, lnk ? lnk->Hidden : false);
 107
 108         if (Node->DuplicateID())
 109         {
 110                 this->SendError("Server ID "+sid+" already exists on the network!");
 111                 this->Instance->SNO->WriteToSnoMask('l',"Server \2"+servername+"\2 being introduced from \2" + prefix + "\2 denied, server ID already exists on the network. Closing link with " + prefix);
 112                 return false;
 113         }
 114
 115         ParentOfThis->AddChild(Node);
 116         params[4] = ":" + params[4];
 117         Utils->DoOneToAllButSender(prefix,"SERVER",params,prefix);
 118         this->Instance->SNO->WriteToSnoMask('l',"Server \002"+prefix+"\002 introduced server \002"+servername+"\002 ("+description+")");
 119         return true;
 120 }
 121
 122 bool TreeSocket::ComparePass(const std::string &ours, const std::string &theirs)
 123 {
 124         if ((!strncmp(ours.c_str(), "HMAC-SHA256:", 12)) || (!strncmp(theirs.c_str(), "HMAC-SHA256:", 12)))
 125         {
 126                 /* One or both of us specified hmac sha256, but we don't have sha256 module loaded!
 127                  * We can't allow this password as valid.
 128                  */
 129                 if (!Instance->Modules->Find("m_sha256.so") || !Utils->ChallengeResponse)
 130                                 return false;
 131                 else
 132                         /* Straight string compare of hashes */
 133                         return ours == theirs;
 134         }
 135         else
 136                 /* Straight string compare of plaintext */
 137                 return ours == theirs;
 138 }
 139
 140 bool TreeSocket::Outbound_Reply_Server(std::deque<std::string> &params)
 141 {
 142         if (params.size() < 5)
 143         {
 144                 SendError("Protocol error - Missing SID");
 145                 return false;
 146         }
 147
 148         irc::string servername = params[0].c_str();
 149         std::string sname = params[0];
 150         std::string password = params[1];
 151         std::string sid = params[3];
 152         std::string description = params[4];
 153         int hops = atoi(params[2].c_str());
 154
 155         this->InboundServerName = sname;
 156         this->InboundDescription = description;
 157         this->InboundSID = sid;
 158
 159         if (!sentcapab)
 160                 this->SendCapabilities();
 161
 162         if (hops)
 163         {
 164                 this->SendError("Server too far away for authentication");
 165                 this->Instance->SNO->WriteToSnoMask('l',"Server connection from \2"+sname+"\2 denied, server is too far away for authentication");
 166                 return false;
 167         }
 168
 169         if (!this->Instance->IsSID(sid))
 170         {
 171                 this->SendError("Invalid format server ID: "+sid+"!");
 172                 return false;
 173         }
 174
 175         for (std::vector<Link>::iterator x = Utils->LinkBlocks.begin(); x < Utils->LinkBlocks.end(); x++)
 176         {
 177                 if ((x->Name == servername) && ((ComparePass(this->MakePass(x->RecvPass,this->GetOurChallenge()),password)) || (x->RecvPass == password && (this->GetTheirChallenge().empty()))))
 178                 {
 179                         TreeServer* CheckDupe = Utils->FindServer(sname);
 180                         if (CheckDupe)
 181                         {
 182                                 this->SendError("Server "+sname+" already exists on server "+CheckDupe->GetParent()->GetName()+"!");
 183                                 this->Instance->SNO->WriteToSnoMask('l',"Server connection from \2"+sname+"\2 denied, already exists on server "+CheckDupe->GetParent()->GetName());
 184                                 return false;
 185                         }
 186                         // Begin the sync here. this kickstarts the
 187                         // other side, waiting in WAIT_AUTH_2 state,
 188                         // into starting their burst, as it shows
 189                         // that we're happy.
 190                         this->LinkState = CONNECTED;
 191                         // we should add the details of this server now
 192                         // to the servers tree, as a child of the root
 193                         // node.
 194
 195                         TreeServer *Node = new TreeServer(this->Utils, this->Instance, sname, description, sid, Utils->TreeRoot, this, x->Hidden);
 196
 197                         if (Node->DuplicateID())
 198                         {
 199                                 this->SendError("Server ID "+sid+" already exists on the network!");
 200                                 this->Instance->SNO->WriteToSnoMask('l',"Server \2"+assign(servername)+"\2 being introduced denied, server ID already exists on the network. Closing link.");
 201                                 return false;
 202                         }
 203
 204                         Utils->TreeRoot->AddChild(Node);
 205                         params[4] = ":" + params[4];
 206                         Utils->DoOneToAllButSender(Instance->Config->GetSID(),"SERVER",params,sname);
 207                         Node->bursting = true;
 208                         this->DoBurst(Node);
 209                         return true;
 210                 }
 211         }
 212         this->SendError("Invalid credentials");
 213         this->Instance->SNO->WriteToSnoMask('l',"Server connection from \2"+sname+"\2 denied, invalid link credentials");
 214         return false;
 215 }
 216
 217 bool TreeSocket::Inbound_Server(std::deque<std::string> &params)
 218 {
 219         if (params.size() < 5)
 220         {
 221                 SendError("Protocol error - Missing SID");
 222                 return false;
 223         }
 224
 225         irc::string servername = params[0].c_str();
 226         std::string sname = params[0];
 227         std::string password = params[1];
 228         std::string sid = params[3];
 229         std::string description = params[4];
 230         int hops = atoi(params[2].c_str());
 231
 232         this->InboundServerName = sname;
 233         this->InboundDescription = description;
 234         this->InboundSID = sid;
 235
 236         if (!sentcapab)
 237                 this->SendCapabilities();
 238
 239         if (hops)
 240         {
 241                 this->SendError("Server too far away for authentication");
 242                 this->Instance->SNO->WriteToSnoMask('l',"Server connection from \2"+sname+"\2 denied, server is too far away for authentication");
 243                 return false;
 244         }
 245
 246         if (!this->Instance->IsSID(sid))
 247         {
 248                 this->SendError("Invalid format server ID: "+sid+"!");
 249                 return false;
 250         }
 251
 252         for (std::vector<Link>::iterator x = Utils->LinkBlocks.begin(); x < Utils->LinkBlocks.end(); x++)
 253         {
 254                 if ((x->Name == servername) && ((ComparePass(this->MakePass(x->RecvPass,this->GetOurChallenge()),password) || x->RecvPass == password && (this->GetTheirChallenge().empty()))))
 255                 {
 256                         /* Check for fully initialized instances of the server by id */
 257                         Instance->Log(DEBUG,"Looking for dupe SID %s", sid.c_str());
 258                         TreeServer* CheckDupeSID = Utils->FindServerID(sid);
 259                         if (CheckDupeSID)
 260                         {
 261                                 this->SendError("Server ID "+CheckDupeSID->GetID()+" already exists on server "+CheckDupeSID->GetName()+"!");
 262                                 this->Instance->SNO->WriteToSnoMask('l',"Server connection from \2"+sname+"\2 denied, server ID '"+CheckDupeSID->GetID()+
 263                                                 "' already exists on server "+CheckDupeSID->GetName());
 264                                 return false;
 265                         }
 266                         /* Now check for fully initialized instances of the server by name */
 267                         TreeServer* CheckDupe = Utils->FindServer(sname);
 268                         if (CheckDupe)
 269                         {
 270                                 this->SendError("Server "+sname+" already exists on server "+CheckDupe->GetParent()->GetName()+"!");
 271                                 this->Instance->SNO->WriteToSnoMask('l',"Server connection from \2"+sname+"\2 denied, already exists on server "+CheckDupe->GetParent()->GetName());
 272                                 return false;
 273                         }
 274                         this->Instance->SNO->WriteToSnoMask('l',"Verified incoming server connection from \002"+sname+"\002["+(x->HiddenFromStats ? "<hidden>" : this->GetIP())+"] ("+description+")");
 275                         if (this->Hook)
 276                         {
 277                                 std::string name = BufferedSocketNameRequest((Module*)Utils->Creator, this->Hook).Send();
 278                                 this->Instance->SNO->WriteToSnoMask('l',"Connection from \2"+sname+"\2["+(x->HiddenFromStats ? "<hidden>" : this->GetIP())+"] using transport \2"+name+"\2");
 279                         }
 280
 281                         // this is good. Send our details: Our server name and description and hopcount of 0,
 282                         // along with the sendpass from this block.
 283                         this->WriteLine(std::string("SERVER ")+this->Instance->Config->ServerName+" "+this->MakePass(x->SendPass, this->GetTheirChallenge())+" 0 "+Instance->Config->GetSID()+" :"+this->Instance->Config->ServerDesc);
 284                         // move to the next state, we are now waiting for THEM.
 285                         this->LinkState = WAIT_AUTH_2;
 286                         return true;
 287                 }
 288         }
 289         this->SendError("Invalid credentials");
 290         this->Instance->SNO->WriteToSnoMask('l',"Server connection from \2"+sname+"\2 denied, invalid link credentials");
 291         return false;
 292 }
 293
 294 void TreeSocket::Split(const std::string &line, std::deque<std::string> &n)
 295 {
 296         n.clear();
 297         irc::tokenstream tokens(line);
 298         std::string param;
 299         while (tokens.GetToken(param))
 300         {
 301                 n.push_back(param);
 302         }
 303         return;
 304 }
 305
 306 bool TreeSocket::ProcessLine(std::string &line)
 307 {
 308         std::deque<std::string> params;
 309         irc::string command;
 310         std::string prefix;
 311
 312         line = line.substr(0, line.find_first_of("\r\n"));
 313
 314         if (line.empty())
 315                 return true;
 316
 317         Instance->Log(DEBUG, "S[%d] I %s", this->GetFd(), line.c_str());
 318
 319         this->Split(line.c_str(),params);
 320
 321         if (params.empty())
 322                 return true;
 323
 324         if ((params[0][0] == ':') && (params.size() > 1))
 325         {
 326                 prefix = params[0].substr(1);
 327                 params.pop_front();
 328
 329                 if (prefix.empty())
 330                 {
 331                         this->SendError("BUG (?) Empty prefix recieved.");
 332                         return false;
 333                 }
 334         }
 335
 336         command = params[0].c_str();
 337         params.pop_front();
 338
 339         switch (this->LinkState)
 340         {
 341                 TreeServer* Node;
 342
 343                 case WAIT_AUTH_1:
 344                         /*
 345                          * State WAIT_AUTH_1:
 346                          *  Waiting for SERVER command from remote server. Server initiating
 347                          *  the connection sends the first SERVER command, listening server
 348                          *  replies with theirs if its happy, then if the initiator is happy,
 349                          *  it starts to send its net sync, which starts the merge, otherwise
 350                          *  it sends an ERROR.
 351                          */
 352                         if (command == "PASS")
 353                         {
 354                                 /*
 355                                  * Ignore this silently. Some services packages insist on sending PASS, even
 356                                  * when it is not required (i.e. by us). We have to ignore this here, otherwise
 357                                  * as it's an unknown command (effectively), it will cause the connection to be
 358                                  * closed, which probably isn't what people want. -- w00t
 359                                  */
 360                         }
 361                         else if (command == "SERVER")
 362                         {
 363                                 return this->Inbound_Server(params);
 364                         }
 365                         else if (command == "ERROR")
 366                         {
 367                                 return this->Error(params);
 368                         }
 369                         else if (command == "USER")
 370                         {
 371                                 this->SendError("Client connections to this port are prohibited.");
 372                                 return false;
 373                         }
 374                         else if (command == "CAPAB")
 375                         {
 376                                 return this->Capab(params);
 377                         }
 378                         else
 379                         {
 380                                 // XXX ...wtf.
 381                                 irc::string error = "Invalid command in negotiation phase: " + command;
 382                                 this->SendError(assign(error));
 383                                 return false;
 384                         }
 385                 break;
 386                 case WAIT_AUTH_2:
 387                         /*
 388                          * State WAIT_AUTH_2:
 389                          *  We have sent SERVER to the other side of the connection. Now we're waiting for them to start BURST.
 390                          *  The other option at this stage of things, of course, is for them to close our connection thanks
 391                          *  to invalid credentials.. -- w
 392                          */
 393                         if (command == "SERVER")
 394                         {
 395                                 /*
 396                                  * Connection is either attempting to re-auth itself (stupid) or sending netburst without sending BURST.
 397                                  * Both of these aren't allowable, so block them here. -- w
 398                                  */
 399                                 this->SendError("You may not re-authenticate or commence netburst without sending BURST.");
 400                                 return true;
 401                         }
 402                         else if (command == "BURST")
 403                         {
 404                                 if (params.size() && Utils->EnableTimeSync)
 405                                 {
 406                                         bool we_have_delta = (Instance->Time(false) != Instance->Time(true));
 407                                         time_t them = atoi(params[0].c_str());
 408                                         time_t delta = them - Instance->Time(false);
 409                                         if ((delta < -600) || (delta > 600))
 410                                         {
 411                                                 Instance->SNO->WriteToSnoMask('l',"\2ERROR\2: Your clocks are out by %d seconds (this is more than five minutes). Link aborted, \2PLEASE SYNC YOUR CLOCKS!\2",abs(delta));
 412                                                 SendError("Your clocks are out by "+ConvToStr(abs(delta))+" seconds (this is more than five minutes). Link aborted, PLEASE SYNC YOUR CLOCKS!");
 413                                                 return false;
 414                                         }
 415                                         else if ((delta < -30) || (delta > 30))
 416                                         {
 417                                                 Instance->SNO->WriteToSnoMask('l',"\2WARNING\2: Your clocks are out by %d seconds. Please consider synching your clocks.", abs(delta));
 418                                         }
 419
 420                                         if (!Utils->MasterTime && !we_have_delta)
 421                                         {
 422                                                 this->Instance->SetTimeDelta(delta);
 423                                                 // Send this new timestamp to any other servers
 424                                                 Utils->DoOneToMany(Instance->Config->GetSID(), "TIMESET", params);
 425                                         }
 426                                 }
 427                                 this->LinkState = CONNECTED;
 428                                 Link* lnk = Utils->FindLink(InboundServerName);
 429
 430                                 Node = new TreeServer(this->Utils, this->Instance, InboundServerName, InboundDescription, InboundSID, Utils->TreeRoot, this, lnk ? lnk->Hidden : false);
 431
 432                                 if (Node->DuplicateID())
 433                                 {
 434                                         this->SendError("Server ID "+InboundSID+" already exists on the network!");
 435                                         this->Instance->SNO->WriteToSnoMask('l',"Server \2"+InboundServerName+"\2 being introduced from \2" + prefix + "\2 denied, server ID already exists on the network. Closing link.");
 436                                         return false;
 437                                 }
 438
 439                                 Utils->TreeRoot->AddChild(Node);
 440                                 params.clear();
 441                                 params.push_back(InboundServerName);
 442                                 params.push_back("*");
 443                                 params.push_back("1");
 444                                 params.push_back(InboundSID);
 445                                 params.push_back(":"+InboundDescription);
 446                                 Utils->DoOneToAllButSender(Instance->Config->GetSID(),"SERVER",params,InboundServerName);
 447                                 Node->bursting = true;
 448                                 this->DoBurst(Node);
 449                         }
 450                         else if (command == "ERROR")
 451                         {
 452                                 return this->Error(params);
 453                         }
 454                         else if (command == "CAPAB")
 455                         {
 456                                 return this->Capab(params);
 457                         }
 458
 459                 break;
 460                 case LISTENER:
 461                         /*
 462                          * This really shouldn't happen.
 463                          */
 464                         this->SendError("Internal error -- listening socket accepted its own descriptor!!!");
 465                         return false;
 466                 break;
 467                 case CONNECTING:
 468                         /*
 469                          * State CONNECTING:
 470                          *  We're connecting (OUTGOING) to another server. They are in state WAIT_AUTH_1 until they verify
 471                          *  our credentials, when they proceed into WAIT_AUTH_2 and send SERVER to us. We then send BURST
 472                          *  + our netburst, which will put them into CONNECTED state. -- w
 473                          */
 474                         if (command == "SERVER")
 475                         {
 476                                 // Our credentials have been accepted, send netburst. (this puts US into the CONNECTED state)
 477                                 return this->Outbound_Reply_Server(params);
 478                         }
 479                         else if (command == "ERROR")
 480                         {
 481                                 return this->Error(params);
 482                         }
 483                         else if (command == "CAPAB")
 484                         {
 485                                 return this->Capab(params);
 486                         }
 487                 break;
 488                 case CONNECTED:
 489                         /*
 490                         * State CONNECTED:
 491                          *  Credentials have been exchanged, we've gotten their 'BURST' (or sent ours).
 492                          *  Anything from here on should be accepted a little more reasonably.
 493                          */
 494                         if (!prefix.empty())
 495                         {
 496                                 /*
 497                                  * Check for fake direction here, and drop any instances that are found.
 498                                  * What is fake direction? Imagine the following server setup:
 499                                  *    0AA <-> 0AB <-> 0AC
 500                                  * Fake direction would be 0AC sending a message to 0AB claiming to be from
 501                                  * 0AA, or something similar. Basically, a message taking a path that *cannot*
 502                                  * be correct.
 503                                  *
 504                                  * When would this be seen?
 505                                  * Well, hopefully never. It could be caused by race conditions, bugs, or
 506                                  * "miscreant" servers, though, so let's check anyway. -- w
 507                                  */
 508                                 std::string direction = prefix;
 509
 510                                 User *t = this->Instance->FindUUID(prefix);
 511                                 if (t)
 512                                 {
 513                                         direction = t->server;
 514                                 }
 515
 516                                 TreeServer* route_back_again = Utils->BestRouteTo(direction);
 517                                 if ((!route_back_again) || (route_back_again->GetSocket() != this))
 518                                 {
 519                                         if (route_back_again)
 520                                                 Instance->Log(DEBUG,"Protocol violation: Fake direction in command '%s' from connection '%s'",line.c_str(),this->GetName().c_str());
 521                                         return true;
 522                                 }
 523                                 /* Fix by brain:
 524                                  * When there is activity on the socket, reset the ping counter so
 525                                  * that we're not wasting bandwidth pinging an active server.
 526                                  */
 527                                 route_back_again->SetNextPingTime(time(NULL) + Utils->PingFreq);
 528                                 route_back_again->SetPingFlag();
 529                         }
 530                         else
 531                         {
 532                                 /*
 533                                  * Empty prefix from a server to server link:
 534                                  *  This is somewhat bad/naughty, so let's set the prefix
 535                                  *  to be the link that we got it from, so we don't break anything. -- w
 536                                  */
 537                                 TreeServer* n = Utils->FindServer(GetName());
 538                                 if (n)
 539                                         prefix = n->GetID();
 540                                 else
 541                                         prefix = GetName();
 542                         }
 543
 544                         /*
 545                          * First up, check for any malformed commands (e.g. MODE without a timestamp)
 546                          * and rewrite commands where necessary (SVSMODE -> MODE for services). -- w
 547                          */
 548                         if (command == "MODE")
 549                         {
 550                                 if (params.size() >= 2)
 551                                 {
 552                                         Channel* channel = Instance->FindChan(params[0]);
 553                                         if (channel)
 554                                         {
 555                                                 User* x = Instance->FindNick(prefix);
 556                                                 if (x)
 557                                                 {
 558                                                         if (warned.find(x->server) == warned.end())
 559                                                         {
 560                                                                 Instance->Log(DEFAULT,"WARNING: I revceived modes '%s' from another server '%s'. This is not compliant with InspIRCd. Please check that server for bugs.", params[1].c_str(), x->server);
 561                                                                 Instance->SNO->WriteToSnoMask('d', "WARNING: The server %s is sending nonstandard modes: '%s MODE %s' where FMODE should be used, and may cause desyncs.", x->server, x->nick, params[1].c_str());
 562                                                                 warned[x->server] = x->nick;
 563                                                         }
 564                                                 }
 565                                         }
 566                                 }
 567                         }
 568                         else if (command == "SVSMODE")
 569                         {
 570                                 command = "MODE";
 571                         }
 572
 573
 574                         /*
 575                          * Now, check for (and parse) commands as appropriate. -- w
 576                          */
 577
 578                         /* Find the server that this command originated from, used in the handlers below */
 579                         TreeServer *ServerSource = Utils->FindServer(prefix);
 580
 581                         /* Find the link we just got this from so we don't bounce it back incorrectly */
 582                         std::string sourceserv = this->myhost;
 583                         if (!this->InboundServerName.empty())
 584                         {
 585                                 sourceserv = this->InboundServerName;
 586                         }
 587
 588                         /*
 589                          * XXX one of these days, this needs to be moved into class Commands.
 590                          */
 591                         if (command == "UID")
 592                         {
 593                                 return this->ParseUID(prefix, params);
 594                         }
 595                         else if (command == "FJOIN")
 596                         {
 597                                 return this->ForceJoin(prefix,params);
 598                         }
 599                         else if (command == "STATS")
 600                         {
 601                                 return this->Stats(prefix, params);
 602                         }
 603                         else if (command == "MOTD")
 604                         {
 605                                 return this->Motd(prefix, params);
 606                         }
 607                         else if (command == "KILL" && ServerSource)
 608                         {
 609                                 // Kill from a server
 610                                 return this->RemoteKill(prefix,params);
 611                         }
 612                         else if (command == "MODULES")
 613                         {
 614                                 return this->Modules(prefix, params);
 615                         }
 616                         else if (command == "ADMIN")
 617                         {
 618                                 return this->Admin(prefix, params);
 619                         }
 620                         else if (command == "SERVER")
 621                         {
 622                                 return this->RemoteServer(prefix,params);
 623                         }
 624                         else if (command == "ERROR")
 625                         {
 626                                 return this->Error(params);
 627                         }
 628                         else if (command == "OPERTYPE")
 629                         {
 630                                 return this->OperType(prefix,params);
 631                         }
 632                         else if (command == "FMODE")
 633                         {
 634                                 return this->ForceMode(prefix,params);
 635                         }
 636                         else if (command == "FTOPIC")
 637                         {
 638                                 return this->ForceTopic(prefix,params);
 639                         }
 640                         else if (command == "REHASH")
 641                         {
 642                                 return this->RemoteRehash(prefix,params);
 643                         }
 644                         else if (command == "METADATA")
 645                         {
 646                                 return this->MetaData(prefix,params);
 647                         }
 648                         else if (command == "REMSTATUS")
 649                         {
 650                                 return this->RemoveStatus(prefix,params);
 651                         }
 652                         else if (command == "PING")
 653                         {
 654                                 return this->LocalPing(prefix,params);
 655                         }
 656                         else if (command == "PONG")
 657                         {
 658                                 return this->LocalPong(prefix,params);
 659                         }
 660                         else if (command == "VERSION")
 661                         {
 662                                 return this->ServerVersion(prefix,params);
 663                         }
 664                         else if (command == "FHOST")
 665                         {
 666                                 return this->ChangeHost(prefix,params);
 667                         }
 668                         else if (command == "FNAME")
 669                         {
 670                                 return this->ChangeName(prefix,params);
 671                         }
 672                         else if (command == "ADDLINE")
 673                         {
 674                                 return this->AddLine(prefix,params);
 675                         }
 676                         else if (command == "DELLINE")
 677                         {
 678                                 return this->DelLine(prefix,params);
 679                         }
 680                         else if (command == "SVSNICK")
 681                         {
 682                                 return this->ForceNick(prefix,params);
 683                         }
 684                         else if (command == "OPERQUIT")
 685                         {
 686                                 return this->OperQuit(prefix,params);
 687                         }
 688                         else if (command == "IDLE")
 689                         {
 690                                 return this->Whois(prefix,params);
 691                         }
 692                         else if (command == "PUSH")
 693                         {
 694                                 return this->Push(prefix,params);
 695                         }
 696                         else if (command == "TIMESET")
 697                         {
 698                                 return this->HandleSetTime(prefix, params);
 699                         }
 700                         else if (command == "TIME")
 701                         {
 702                                 return this->Time(prefix,params);
 703                         }
 704                         else if ((command == "KICK") && (Utils->IsServer(prefix)))
 705                         {
 706                                 if (params.size() == 3)
 707                                 {
 708                                         User* user = this->Instance->FindNick(params[1]);
 709                                         Channel* chan = this->Instance->FindChan(params[0]);
 710                                         if (user && chan)
 711                                         {
 712                                                 if (!chan->ServerKickUser(user, params[2].c_str(), false))
 713                                                         /* Yikes, the channels gone! */
 714                                                         delete chan;
 715                                         }
 716                                 }
 717
 718                                 return Utils->DoOneToAllButSenderRaw(line,sourceserv,prefix,command,params);
 719                         }
 720                         else if (command == "SVSJOIN")
 721                         {
 722                                 return this->ServiceJoin(prefix,params);
 723                         }
 724                         else if (command == "SVSPART")
 725                         {
 726                                 return this->ServicePart(prefix,params);
 727                         }
 728                         else if (command == "SQUIT")
 729                         {
 730                                 if (params.size() == 2)
 731                                 {
 732                                         this->Squit(Utils->FindServer(params[0]),params[1]);
 733                                 }
 734                                 return true;
 735                         }
 736                         else if (command == "OPERNOTICE")
 737                         {
 738                                 if (params.size() >= 1)
 739                                         Instance->SNO->WriteToSnoMask('A', "From " + prefix + ": " + params[0]);
 740                                 return Utils->DoOneToAllButSenderRaw(line, sourceserv, prefix, command, params);
 741                         }
 742                         else if (command == "MODENOTICE")
 743                         {
 744                                 if (params.size() >= 2)
 745                                 {
 746                                         Instance->Users->WriteMode(params[0].c_str(), WM_AND, "*** From %s: %s", prefix.c_str(), params[1].c_str());
 747                                 }
 748                                 return Utils->DoOneToAllButSenderRaw(line, sourceserv, prefix, command, params);
 749                         }
 750                         else if (command == "SNONOTICE")
 751                         {
 752                                 if (params.size() >= 2)
 753                                 {
 754                                         Instance->SNO->WriteToSnoMask(*(params[0].c_str()), "From " + prefix + ": "+ params[1]);
 755                                 }
 756                                 return Utils->DoOneToAllButSenderRaw(line, sourceserv, prefix, command, params);
 757                         }
 758                         else if (command == "BURST")
 759                         {
 760                                 // Set prefix server as bursting
 761                                 if (!ServerSource)
 762                                 {
 763                                         this->Instance->SNO->WriteToSnoMask('l', "WTF: Got BURST from a nonexistant server(?): %s", prefix.c_str());
 764                                         return false;
 765                                 }
 766
 767                                 ServerSource->bursting = true;
 768                                 return Utils->DoOneToAllButSenderRaw(line, sourceserv, prefix, command, params);
 769                         }
 770                         else if (command == "ENDBURST")
 771                         {
 772                                 if (!ServerSource)
 773                                 {
 774                                         this->Instance->SNO->WriteToSnoMask('l', "WTF: Got ENDBURST from a nonexistant server(?): %s", prefix.c_str());
 775                                         return false;
 776                                 }
 777
 778                                 ServerSource->FinishBurst();
 779                                 return Utils->DoOneToAllButSenderRaw(line, sourceserv, prefix, command, params);
 780                         }
 781                         else if (command == "MODE")
 782                         {
 783                                 // Server-prefix MODE.
 784                                 const char* modelist[MAXPARAMETERS];
 785                                 for (size_t i = 0; i < params.size(); i++)
 786                                         modelist[i] = params[i].c_str();
 787
 788                                 // Insert into the parser
 789                                 this->Instance->SendMode(modelist, params.size(), this->Instance->FakeClient);
 790
 791                                 // Pass out to the network
 792                                 return Utils->DoOneToAllButSenderRaw(line,sourceserv,prefix,command,params);
 793                         }
 794                         else
 795                         {
 796                                 /*
 797                                  * Not a special s2s command. Emulate the user doing it.
 798                                  * This saves us having a huge ugly command parser again.
 799                                  */
 800                                 User *who = this->Instance->FindUUID(prefix);
 801
 802                                 if (!who)
 803                                 {
 804                                         // this looks ugly because command is an irc::string
 805                                         this->SendError("Command (" + std::string(command.c_str()) + ") from unknown prefix (" + prefix + ")! Dropping link.");
 806                                         return false;
 807                                 }
 808
 809                                 if (command == "NICK")
 810                                 {
 811                                         if (params.size() != 2)
 812                                         {
 813                                                 SendError("Protocol violation: NICK message without TS - :"+std::string(who->uuid)+" NICK "+params[0]);
 814                                                 return false;
 815                                         }
 816                                         /* Update timestamp on user when they change nicks */
 817                                         who->age = atoi(params[1].c_str());
 818
 819                                         /*
 820                                          * On nick messages, check that the nick doesnt already exist here.
 821                                          * If it does, perform collision logic.
 822                                          */
 823                                         User* x = this->Instance->FindNickOnly(params[0]);
 824                                         if ((x) && (x != who))
 825                                         {
 826                                                 int collideret = 0;
 827                                                 /* x is local, who is remote */
 828                                                 collideret = this->DoCollision(x, who->age, who->ident, who->GetIPString(), who->uuid);
 829                                                 if (collideret != 1)
 830                                                 {
 831                                                         /*
 832                                                          * Remote client lost, or both lost, parsing this nickchange would be
 833                                                          * pointless, as the incoming client's server will soon recieve SVSNICK to
 834                                                          * change its nick to its UID. :) -- w00t
 835                                                          */
 836                                                         return true;
 837                                                 }
 838                                         }
 839                                 }
 840
 841                                 // its a user
 842                                 const char* strparams[127];
 843                                 for (unsigned int q = 0; q < params.size(); q++)
 844                                 {
 845                                         strparams[q] = params[q].c_str();
 846                                 }
 847
 848                                 switch (this->Instance->CallCommandHandler(command.c_str(), strparams, params.size(), who))
 849                                 {
 850                                         case CMD_INVALID:
 851                                                 // command is irc::string, hence ugliness
 852                                                 this->SendError("Unrecognised or malformed command '" + std::string(command.c_str()) + "' -- possibly loaded mismatched modules");
 853                                                 return false;
 854                                                 break;
 855                                         /*
 856                                          * CMD_LOCALONLY is aliased to CMD_FAILURE, so this won't go out onto the network.
 857                                          */
 858                                         case CMD_FAILURE:
 859                                                 return true;
 860                                                 break;
 861                                         default:
 862                                                 /* CMD_SUCCESS and CMD_USER_DELETED fall through here */
 863                                                 break;
 864                                 }
 865
 866                                 return Utils->DoOneToAllButSenderRaw(line,sourceserv,prefix,command,params);
 867
 868                         }
 869                         return true;
 870                         break; // end of state CONNECTED (phew).
 871         }
 872         return true;
 873 }
 874
 875 std::string TreeSocket::GetName()
 876 {
 877         std::string sourceserv = this->myhost;
 878         if (!this->InboundServerName.empty())
 879         {
 880                 sourceserv = this->InboundServerName;
 881         }
 882         return sourceserv;
 883 }
 884
 885 void TreeSocket::OnTimeout()
 886 {
 887         if (this->LinkState == CONNECTING)
 888         {
 889                 Utils->Creator->RemoteMessage(NULL, "CONNECT: Connection to \002%s\002 timed out.", myhost.c_str());
 890                 Link* MyLink = Utils->FindLink(myhost);
 891                 if (MyLink)
 892                         Utils->DoFailOver(MyLink);
 893         }
 894 }
 895
 896 void TreeSocket::OnClose()
 897 {
 898         // Test fix for big fuckup
 899         if (this->LinkState != CONNECTED)
 900                 return;
 901
 902         // Connection closed.
 903         // If the connection is fully up (state CONNECTED)
 904         // then propogate a netsplit to all peers.
 905         std::string quitserver = this->myhost;
 906         if (!this->InboundServerName.empty())
 907         {
 908                 quitserver = this->InboundServerName;
 909         }
 910         TreeServer* s = Utils->FindServer(quitserver);
 911         if (s)
 912         {
 913                 Squit(s,"Remote host closed the connection");
 914         }
 915
 916         if (!quitserver.empty())
 917         {
 918                 Utils->Creator->RemoteMessage(NULL,"Connection to '\2%s\2' failed.",quitserver.c_str());
 919                 time_t server_uptime = Instance->Time() - this->age;
 920                 if (server_uptime)
 921                         Utils->Creator->RemoteMessage(NULL,"Connection to '\2%s\2' was established for %s", quitserver.c_str(), Utils->Creator->TimeToStr(server_uptime).c_str());
 922         }
 923 }
 924
 925 int TreeSocket::OnIncomingConnection(int newsock, char* ip)
 926 {
 927         /* To prevent anyone from attempting to flood opers/DDoS by connecting to the server port,
 928          * or discovering if this port is the server port, we don't allow connections from any
 929          * IPs for which we don't have a link block.
 930          */
 931         bool found = false;
 932
 933         found = (std::find(Utils->ValidIPs.begin(), Utils->ValidIPs.end(), ip) != Utils->ValidIPs.end());
 934         if (!found)
 935         {
 936                 for (std::vector<std::string>::iterator i = Utils->ValidIPs.begin(); i != Utils->ValidIPs.end(); i++)
 937                         if (irc::sockets::MatchCIDR(ip, (*i).c_str()))
 938                                 found = true;
 939
 940                 if (!found)
 941                 {
 942                         Utils->Creator->RemoteMessage(NULL,"Server connection from %s denied (no link blocks with that IP address)", ip);
 943                         Instance->SE->Close(newsock);
 944                         return false;
 945                 }
 946         }
 947
 948         TreeSocket* s = new TreeSocket(this->Utils, this->Instance, newsock, ip, this->Hook);
 949         s = s; /* Whinge whinge whinge, thats all GCC ever does. */
 950         return true;
 951 }