src/modules/m_spanningtree/treesocket2.cpp

   1 /*
   2  * InspIRCd -- Internet Relay Chat Daemon
   3  *
   4  *   Copyright (C) 2007-2008, 2012 Robin Burchell <robin+git@viroteck.net>
   5  *   Copyright (C) 2009-2010 Daniel De Graaf <danieldg@inspircd.org>
   6  *   Copyright (C) 2007-2008 Craig Edwards <craigedwards@brainbox.cc>
   7  *   Copyright (C) 2008 Pippijn van Steenhoven <pip88nl@gmail.com>
   8  *   Copyright (C) 2008 Thomas Stagner <aquanight@inspircd.org>
   9  *   Copyright (C) 2007 Dennis Friis <peavey@inspircd.org>
  10  *
  11  * This file is part of InspIRCd.  InspIRCd is free software: you can
  12  * redistribute it and/or modify it under the terms of the GNU General Public
  13  * License as published by the Free Software Foundation, version 2.
  14  *
  15  * This program is distributed in the hope that it will be useful, but WITHOUT
  16  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
  17  * FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more
  18  * details.
  19  *
  20  * You should have received a copy of the GNU General Public License
  21  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  22  */
  23
  24
  25 #include "inspircd.h"
  26
  27 #include "main.h"
  28 #include "utils.h"
  29 #include "treeserver.h"
  30 #include "treesocket.h"
  31 #include "resolvers.h"
  32
  33 /* Handle ERROR command */
  34 void TreeSocket::Error(parameterlist &params)
  35 {
  36         std::string msg = params.size() ? params[0] : "";
  37         SetError("received ERROR " + msg);
  38 }
  39
  40 void TreeSocket::Split(const std::string& line, std::string& prefix, std::string& command, parameterlist& params)
  41 {
  42         irc::tokenstream tokens(line);
  43
  44         if (!tokens.GetToken(prefix))
  45                 return;
  46
  47         if (prefix[0] == ':')
  48         {
  49                 prefix = prefix.substr(1);
  50
  51                 if (prefix.empty())
  52                 {
  53                         this->SendError("BUG (?) Empty prefix received: " + line);
  54                         return;
  55                 }
  56                 if (!tokens.GetToken(command))
  57                 {
  58                         this->SendError("BUG (?) Empty command received: " + line);
  59                         return;
  60                 }
  61         }
  62         else
  63         {
  64                 command = prefix;
  65                 prefix.clear();
  66         }
  67         if (command.empty())
  68                 this->SendError("BUG (?) Empty command received: " + line);
  69
  70         std::string param;
  71         while (tokens.GetToken(param))
  72         {
  73                 params.push_back(param);
  74         }
  75 }
  76
  77 void TreeSocket::ProcessLine(std::string &line)
  78 {
  79         std::string prefix;
  80         std::string command;
  81         parameterlist params;
  82
  83         ServerInstance->Logs->Log(MODNAME, LOG_RAWIO, "S[%d] I %s", this->GetFd(), line.c_str());
  84
  85         Split(line, prefix, command, params);
  86
  87         if (command.empty())
  88                 return;
  89
  90         switch (this->LinkState)
  91         {
  92                 case WAIT_AUTH_1:
  93                         /*
  94                          * State WAIT_AUTH_1:
  95                          *  Waiting for SERVER command from remote server. Server initiating
  96                          *  the connection sends the first SERVER command, listening server
  97                          *  replies with theirs if its happy, then if the initiator is happy,
  98                          *  it starts to send its net sync, which starts the merge, otherwise
  99                          *  it sends an ERROR.
 100                          */
 101                         if (command == "PASS")
 102                         {
 103                                 /*
 104                                  * Ignore this silently. Some services packages insist on sending PASS, even
 105                                  * when it is not required (i.e. by us). We have to ignore this here, otherwise
 106                                  * as it's an unknown command (effectively), it will cause the connection to be
 107                                  * closed, which probably isn't what people want. -- w00t
 108                                  */
 109                         }
 110                         else if (command == "SERVER")
 111                         {
 112                                 this->Inbound_Server(params);
 113                         }
 114                         else if (command == "ERROR")
 115                         {
 116                                 this->Error(params);
 117                         }
 118                         else if (command == "USER")
 119                         {
 120                                 this->SendError("Client connections to this port are prohibited.");
 121                         }
 122                         else if (command == "CAPAB")
 123                         {
 124                                 this->Capab(params);
 125                         }
 126                         else
 127                         {
 128                                 this->SendError("Invalid command in negotiation phase: " + command);
 129                         }
 130                 break;
 131                 case WAIT_AUTH_2:
 132                         /*
 133                          * State WAIT_AUTH_2:
 134                          *  We have sent SERVER to the other side of the connection. Now we're waiting for them to start BURST.
 135                          *  The other option at this stage of things, of course, is for them to close our connection thanks
 136                          *  to invalid credentials.. -- w
 137                          */
 138                         if (command == "SERVER")
 139                         {
 140                                 /*
 141                                  * Connection is either attempting to re-auth itself (stupid) or sending netburst without sending BURST.
 142                                  * Both of these aren't allowable, so block them here. -- w
 143                                  */
 144                                 this->SendError("You may not re-authenticate or commence netburst without sending BURST.");
 145                         }
 146                         else if (command == "BURST")
 147                         {
 148                                 if (params.size())
 149                                 {
 150                                         time_t them = ConvToInt(params[0]);
 151                                         time_t delta = them - ServerInstance->Time();
 152                                         if ((delta < -600) || (delta > 600))
 153                                         {
 154                                                 ServerInstance->SNO->WriteGlobalSno('l',"\2ERROR\2: Your clocks are out by %d seconds (this is more than five minutes). Link aborted, \2PLEASE SYNC YOUR CLOCKS!\2",abs((long)delta));
 155                                                 SendError("Your clocks are out by "+ConvToStr(abs((long)delta))+" seconds (this is more than five minutes). Link aborted, PLEASE SYNC YOUR CLOCKS!");
 156                                                 return;
 157                                         }
 158                                         else if ((delta < -30) || (delta > 30))
 159                                         {
 160                                                 ServerInstance->SNO->WriteGlobalSno('l',"\2WARNING\2: Your clocks are out by %d seconds. Please consider synching your clocks.", abs((long)delta));
 161                                         }
 162                                 }
 163
 164                                 // Check for duplicate server name/sid again, it's possible that a new
 165                                 // server was introduced while we were waiting for them to send BURST.
 166                                 // (we do not reserve their server name/sid when they send SERVER, we do it now)
 167                                 if (!CheckDuplicate(capab->name, capab->sid))
 168                                         return;
 169
 170                                 this->LinkState = CONNECTED;
 171                                 Utils->timeoutlist.erase(this);
 172
 173                                 linkID = capab->name;
 174
 175                                 MyRoot = new TreeServer(capab->name, capab->description, capab->sid, Utils->TreeRoot, this, capab->hidden);
 176                                 Utils->TreeRoot->AddChild(MyRoot);
 177
 178                                 MyRoot->bursting = true;
 179                                 this->DoBurst(MyRoot);
 180
 181                                 parameterlist sparams;
 182                                 sparams.push_back(MyRoot->GetName());
 183                                 sparams.push_back("*");
 184                                 sparams.push_back("0");
 185                                 sparams.push_back(MyRoot->GetID());
 186                                 sparams.push_back(":" + MyRoot->GetDesc());
 187                                 Utils->DoOneToAllButSender(ServerInstance->Config->GetSID(), "SERVER", sparams, MyRoot);
 188                                 Utils->DoOneToAllButSender(MyRoot->GetID(), "BURST", params, MyRoot);
 189                         }
 190                         else if (command == "ERROR")
 191                         {
 192                                 this->Error(params);
 193                         }
 194                         else if (command == "CAPAB")
 195                         {
 196                                 this->Capab(params);
 197                         }
 198
 199                 break;
 200                 case CONNECTING:
 201                         /*
 202                          * State CONNECTING:
 203                          *  We're connecting (OUTGOING) to another server. They are in state WAIT_AUTH_1 until they verify
 204                          *  our credentials, when they proceed into WAIT_AUTH_2 and send SERVER to us. We then send BURST
 205                          *  + our netburst, which will put them into CONNECTED state. -- w
 206                          */
 207                         if (command == "SERVER")
 208                         {
 209                                 // Our credentials have been accepted, send netburst. (this puts US into the CONNECTED state)
 210                                 this->Outbound_Reply_Server(params);
 211                         }
 212                         else if (command == "ERROR")
 213                         {
 214                                 this->Error(params);
 215                         }
 216                         else if (command == "CAPAB")
 217                         {
 218                                 this->Capab(params);
 219                         }
 220                 break;
 221                 case CONNECTED:
 222                         /*
 223                          * State CONNECTED:
 224                          *  Credentials have been exchanged, we've gotten their 'BURST' (or sent ours).
 225                          *  Anything from here on should be accepted a little more reasonably.
 226                          */
 227                         this->ProcessConnectedLine(prefix, command, params);
 228                 break;
 229                 case DYING:
 230                 break;
 231         }
 232 }
 233
 234 void TreeSocket::ProcessConnectedLine(std::string& prefix, std::string& command, parameterlist& params)
 235 {
 236         User* who = ServerInstance->FindUUID(prefix);
 237         std::string direction;
 238
 239         if (!who)
 240         {
 241                 TreeServer* ServerSource = Utils->FindServer(prefix);
 242                 if (prefix.empty())
 243                         ServerSource = MyRoot;
 244
 245                 if (ServerSource)
 246                 {
 247                         who = ServerSource->ServerUser;
 248                 }
 249                 else
 250                 {
 251                         /* It is important that we don't close the link here, unknown prefix can occur
 252                          * due to various race conditions such as the KILL message for a user somehow
 253                          * crossing the users QUIT further upstream from the server. Thanks jilles!
 254                          */
 255
 256                         if ((prefix.length() == UIDGenerator::UUID_LENGTH) && (isdigit(prefix[0])) &&
 257                                 ((command == "FMODE") || (command == "MODE") || (command == "KICK") || (command == "TOPIC") || (command == "KILL") || (command == "ADDLINE") || (command == "DELLINE")))
 258                         {
 259                                 /* Special case, we cannot drop these commands as they've been committed already on a
 260                                  * part of the network by the time we receive them, so in this scenario pretend the
 261                                  * command came from a server to avoid desync.
 262                                  */
 263
 264                                 who = ServerInstance->FindUUID(prefix.substr(0, 3));
 265                                 if (!who)
 266                                         who = this->MyRoot->ServerUser;
 267                         }
 268                         else
 269                         {
 270                                 ServerInstance->Logs->Log(MODNAME, LOG_DEBUG, "Command '%s' from unknown prefix '%s'! Dropping entire command.",
 271                                         command.c_str(), prefix.c_str());
 272                                 return;
 273                         }
 274                 }
 275         }
 276
 277         // Make sure prefix is still good
 278         direction = who->server;
 279         prefix = who->uuid;
 280
 281         /*
 282          * Check for fake direction here, and drop any instances that are found.
 283          * What is fake direction? Imagine the following server setup:
 284          *    0AA <-> 0AB <-> 0AC
 285          * Fake direction would be 0AC sending a message to 0AB claiming to be from
 286          * 0AA, or something similar. Basically, a message taking a path that *cannot*
 287          * be correct.
 288          *
 289          * When would this be seen?
 290          * Well, hopefully never. It could be caused by race conditions, bugs, or
 291          * "miscreant" servers, though, so let's check anyway. -- w
 292          *
 293          * We also check here for totally invalid prefixes (prefixes that are neither
 294          * a valid SID or a valid UUID, so that invalid UUID or SID never makes it
 295          * to the higher level functions. -- B
 296          */
 297         TreeServer* route_back_again = Utils->BestRouteTo(direction);
 298         if ((!route_back_again) || (route_back_again->GetSocket() != this))
 299         {
 300                 if (route_back_again)
 301                         ServerInstance->Logs->Log(MODNAME, LOG_DEBUG, "Protocol violation: Fake direction '%s' from connection '%s'",
 302                                 prefix.c_str(),linkID.c_str());
 303                 return;
 304         }
 305
 306         // Translate commands coming from servers using an older protocol
 307         if (proto_version < ProtocolVersion)
 308         {
 309                 if (!PreProcessOldProtocolMessage(who, command, params))
 310                         return;
 311         }
 312
 313         ServerCommand* scmd = Utils->Creator->CmdManager.GetHandler(command);
 314         CommandBase* cmdbase = scmd;
 315         Command* cmd;
 316         if (!scmd)
 317         {
 318                 // Not a special server-to-server command
 319                 cmd = ServerInstance->Parser->GetHandler(command);
 320                 if (!cmd)
 321                 {
 322                         irc::stringjoiner pmlist(params);
 323                         ServerInstance->Logs->Log(MODNAME, LOG_SPARSE, "Unrecognised S2S command :%s %s %s",
 324                                 who->uuid.c_str(), command.c_str(), pmlist.GetJoined().c_str());
 325                         SendError("Unrecognised command '" + command + "' -- possibly loaded mismatched modules");
 326                         return;
 327                 }
 328                 cmdbase = cmd;
 329         }
 330
 331         if (params.size() < cmdbase->min_params)
 332         {
 333                 irc::stringjoiner pmlist(params);
 334                 ServerInstance->Logs->Log(MODNAME, LOG_SPARSE, "Insufficient parameters for S2S command :%s %s %s",
 335                         who->uuid.c_str(), command.c_str(), pmlist.GetJoined().c_str());
 336                 SendError("Insufficient parameters for command '" + command + "'");
 337                 return;
 338         }
 339
 340         if ((!params.empty()) && (params.back().empty()) && (!cmdbase->allow_empty_last_param))
 341         {
 342                 // 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
 343                 if (params.size()-1 < cmdbase->min_params)
 344                         return;
 345                 params.pop_back();
 346         }
 347
 348         CmdResult res;
 349         if (scmd)
 350                 res = scmd->Handle(who, params);
 351         else
 352                 res = cmd->Handle(params, who);
 353
 354         if (res == CMD_INVALID)
 355         {
 356                 irc::stringjoiner pmlist(params);
 357                 ServerInstance->Logs->Log(MODNAME, LOG_SPARSE, "Error handling S2S command :%s %s %s",
 358                         who->uuid.c_str(), command.c_str(), pmlist.GetJoined().c_str());
 359                 SendError("Error handling '" + command + "' -- possibly loaded mismatched modules");
 360         }
 361         else if (res == CMD_SUCCESS)
 362                 Utils->RouteCommand(route_back_again, cmdbase, params, who);
 363 }
 364
 365 void TreeSocket::OnTimeout()
 366 {
 367         ServerInstance->SNO->WriteGlobalSno('l', "CONNECT: Connection to \002%s\002 timed out.", linkID.c_str());
 368 }
 369
 370 void TreeSocket::Close()
 371 {
 372         if (fd != -1)
 373                 ServerInstance->GlobalCulls.AddItem(this);
 374         this->BufferedSocket::Close();
 375         SetError("Remote host closed connection");
 376
 377         // Connection closed.
 378         // If the connection is fully up (state CONNECTED)
 379         // then propogate a netsplit to all peers.
 380         if (MyRoot)
 381                 Squit(MyRoot,getError());
 382
 383         if (!ConnectionFailureShown)
 384         {
 385                 ConnectionFailureShown = true;
 386                 ServerInstance->SNO->WriteGlobalSno('l', "Connection to '\2%s\2' failed.",linkID.c_str());
 387
 388                 time_t server_uptime = ServerInstance->Time() - this->age;
 389                 if (server_uptime)
 390                 {
 391                         std::string timestr = ModuleSpanningTree::TimeToStr(server_uptime);
 392                         ServerInstance->SNO->WriteGlobalSno('l', "Connection to '\2%s\2' was established for %s", linkID.c_str(), timestr.c_str());
 393                 }
 394         }
 395 }