/* * InspIRCd -- Internet Relay Chat Daemon * * Copyright (C) 2007-2008, 2012 Robin Burchell * Copyright (C) 2009-2010 Daniel De Graaf * Copyright (C) 2007-2008 Craig Edwards * Copyright (C) 2008 Pippijn van Steenhoven * Copyright (C) 2008 Thomas Stagner * Copyright (C) 2007 Dennis Friis * * This file is part of InspIRCd. InspIRCd is free software: you can * redistribute it and/or modify it under the terms of the GNU General Public * License as published by the Free Software Foundation, version 2. * * This program is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS * FOR A PARTICULAR PURPOSE. See the GNU General Public License for more * details. * * You should have received a copy of the GNU General Public License * along with this program. If not, see . */ #include "inspircd.h" #include "socket.h" #include "xline.h" #include "socketengine.h" #include "main.h" #include "utils.h" #include "treeserver.h" #include "link.h" #include "treesocket.h" #include "resolvers.h" /* Handle ERROR command */ void TreeSocket::Error(parameterlist ¶ms) { std::string msg = params.size() ? params[0] : ""; SetError("received ERROR " + msg); } void TreeSocket::Split(const std::string& line, std::string& prefix, std::string& command, parameterlist& params) { irc::tokenstream tokens(line); if (!tokens.GetToken(prefix)) return; if (prefix[0] == ':') { prefix = prefix.substr(1); if (prefix.empty()) { this->SendError("BUG (?) Empty prefix received: " + line); return; } if (!tokens.GetToken(command)) { this->SendError("BUG (?) Empty command received: " + line); return; } } else { command = prefix; prefix.clear(); } if (command.empty()) this->SendError("BUG (?) Empty command received: " + line); std::string param; while (tokens.GetToken(param)) { params.push_back(param); } } void TreeSocket::ProcessLine(std::string &line) { std::string prefix; std::string command; parameterlist params; ServerInstance->Logs->Log("m_spanningtree", RAWIO, "S[%d] I %s", this->GetFd(), line.c_str()); Split(line, prefix, command, params); if (command.empty()) return; switch (this->LinkState) { case WAIT_AUTH_1: /* * State WAIT_AUTH_1: * Waiting for SERVER command from remote server. Server initiating * the connection sends the first SERVER command, listening server * replies with theirs if its happy, then if the initiator is happy, * it starts to send its net sync, which starts the merge, otherwise * it sends an ERROR. */ if (command == "PASS") { /* * Ignore this silently. Some services packages insist on sending PASS, even * when it is not required (i.e. by us). We have to ignore this here, otherwise * as it's an unknown command (effectively), it will cause the connection to be * closed, which probably isn't what people want. -- w00t */ } else if (command == "SERVER") { this->Inbound_Server(params); } else if (command == "ERROR") { this->Error(params); } else if (command == "USER") { this->SendError("Client connections to this port are prohibited."); } else if (command == "CAPAB") { this->Capab(params); } else { this->SendError("Invalid command in negotiation phase: " + command); } break; case WAIT_AUTH_2: /* * State WAIT_AUTH_2: * We have sent SERVER to the other side of the connection. Now we're waiting for them to start BURST. * The other option at this stage of things, of course, is for them to close our connection thanks * to invalid credentials.. -- w */ if (command == "SERVER") { /* * Connection is either attempting to re-auth itself (stupid) or sending netburst without sending BURST. * Both of these aren't allowable, so block them here. -- w */ this->SendError("You may not re-authenticate or commence netburst without sending BURST."); } else if (command == "BURST") { if (params.size()) { time_t them = atoi(params[0].c_str()); time_t delta = them - ServerInstance->Time(); if ((delta < -600) || (delta > 600)) { 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)); SendError("Your clocks are out by "+ConvToStr(abs((long)delta))+" seconds (this is more than five minutes). Link aborted, PLEASE SYNC YOUR CLOCKS!"); return; } else if ((delta < -30) || (delta > 30)) { ServerInstance->SNO->WriteGlobalSno('l',"\2WARNING\2: Your clocks are out by %d seconds. Please consider synching your clocks.", abs((long)delta)); } } this->LinkState = CONNECTED; Utils->timeoutlist.erase(this); MyRoot->bursting = true; this->DoBurst(MyRoot); parameterlist sparams; sparams.push_back(MyRoot->GetName()); sparams.push_back("*"); sparams.push_back("0"); sparams.push_back(MyRoot->GetID()); sparams.push_back(":" + MyRoot->GetDesc()); Utils->DoOneToAllButSender(ServerInstance->Config->GetSID(), "SERVER", sparams, MyRoot->GetName()); Utils->DoOneToAllButSender(MyRoot->GetID(), "BURST", params, MyRoot->GetName()); } else if (command == "ERROR") { this->Error(params); } else if (command == "CAPAB") { this->Capab(params); } break; case CONNECTING: /* * State CONNECTING: * We're connecting (OUTGOING) to another server. They are in state WAIT_AUTH_1 until they verify * our credentials, when they proceed into WAIT_AUTH_2 and send SERVER to us. We then send BURST * + our netburst, which will put them into CONNECTED state. -- w */ if (command == "SERVER") { // Our credentials have been accepted, send netburst. (this puts US into the CONNECTED state) this->Outbound_Reply_Server(params); } else if (command == "ERROR") { this->Error(params); } else if (command == "CAPAB") { this->Capab(params); } break; case CONNECTED: /* * State CONNECTED: * Credentials have been exchanged, we've gotten their 'BURST' (or sent ours). * Anything from here on should be accepted a little more reasonably. */ this->ProcessConnectedLine(prefix, command, params); break; case DYING: break; } } void TreeSocket::ProcessConnectedLine(std::string& prefix, std::string& command, parameterlist& params) { User* who = ServerInstance->FindUUID(prefix); std::string direction; if (!who) { TreeServer* ServerSource = Utils->FindServer(prefix); if (prefix.empty()) ServerSource = MyRoot; if (ServerSource) { who = ServerSource->ServerUser; } else { /* It is important that we don't close the link here, unknown prefix can occur * due to various race conditions such as the KILL message for a user somehow * crossing the users QUIT further upstream from the server. Thanks jilles! */ if ((prefix.length() == UUID_LENGTH-1) && (isdigit(prefix[0])) && ((command == "FMODE") || (command == "MODE") || (command == "KICK") || (command == "TOPIC") || (command == "KILL") || (command == "ADDLINE") || (command == "DELLINE"))) { /* Special case, we cannot drop these commands as they've been committed already on a * part of the network by the time we receive them, so in this scenario pretend the * command came from a server to avoid desync. */ who = ServerInstance->FindUUID(prefix.substr(0, 3)); if (!who) who = this->MyRoot->ServerUser; } else { ServerInstance->Logs->Log("m_spanningtree", DEBUG, "Command '%s' from unknown prefix '%s'! Dropping entire command.", command.c_str(), prefix.c_str()); return; } } } // Make sure prefix is still good direction = who->server; prefix = who->uuid; /* * Check for fake direction here, and drop any instances that are found. * What is fake direction? Imagine the following server setup: * 0AA <-> 0AB <-> 0AC * Fake direction would be 0AC sending a message to 0AB claiming to be from * 0AA, or something similar. Basically, a message taking a path that *cannot* * be correct. * * When would this be seen? * Well, hopefully never. It could be caused by race conditions, bugs, or * "miscreant" servers, though, so let's check anyway. -- w * * We also check here for totally invalid prefixes (prefixes that are neither * a valid SID or a valid UUID, so that invalid UUID or SID never makes it * to the higher level functions. -- B */ TreeServer* route_back_again = Utils->BestRouteTo(direction); if ((!route_back_again) || (route_back_again->GetSocket() != this)) { if (route_back_again) ServerInstance->Logs->Log("m_spanningtree",DEBUG,"Protocol violation: Fake direction '%s' from connection '%s'", prefix.c_str(),linkID.c_str()); return; } /* * First up, check for any malformed commands (e.g. MODE without a timestamp) * and rewrite commands where necessary (SVSMODE -> MODE for services). -- w */ if (command == "SVSMODE") // This isn't in an "else if" so we still force FMODE for changes on channels. command = "MODE"; // TODO move all this into Commands if (command == "MAP") { Utils->Creator->HandleMap(params, who); } else if (command == "SERVER") { this->RemoteServer(prefix,params); } else if (command == "ERROR") { this->Error(params); } else if (command == "AWAY") { this->Away(prefix,params); } else if (command == "PING") { this->LocalPing(prefix,params); } else if (command == "PONG") { TreeServer *s = Utils->FindServer(prefix); if (s && s->bursting) { ServerInstance->SNO->WriteGlobalSno('l',"Server \002%s\002 has not finished burst, forcing end of burst (send ENDBURST!)", prefix.c_str()); s->FinishBurst(); } this->LocalPong(prefix,params); } else if (command == "VERSION") { this->ServerVersion(prefix,params); } else if (command == "ADDLINE") { this->AddLine(prefix,params); } else if (command == "DELLINE") { this->DelLine(prefix,params); } else if (command == "SAVE") { this->ForceNick(prefix,params); } else if (command == "OPERQUIT") { this->OperQuit(prefix,params); } else if (command == "IDLE") { this->Whois(prefix,params); } else if (command == "PUSH") { this->Push(prefix,params); } else if (command == "SQUIT") { if (params.size() == 2) { this->Squit(Utils->FindServer(params[0]),params[1]); } } else if (command == "SNONOTICE") { if (params.size() >= 2) { ServerInstance->SNO->WriteToSnoMask(params[0][0], "From " + who->nick + ": "+ params[1]); params[1] = ":" + params[1]; Utils->DoOneToAllButSender(prefix, command, params, prefix); } } else if (command == "BURST") { // Set prefix server as bursting TreeServer* ServerSource = Utils->FindServer(prefix); if (!ServerSource) { ServerInstance->SNO->WriteGlobalSno('l', "WTF: Got BURST from a non-server(?): %s", prefix.c_str()); return; } ServerSource->bursting = true; Utils->DoOneToAllButSender(prefix, command, params, prefix); } else if (command == "ENDBURST") { TreeServer* ServerSource = Utils->FindServer(prefix); if (!ServerSource) { ServerInstance->SNO->WriteGlobalSno('l', "WTF: Got ENDBURST from a non-server(?): %s", prefix.c_str()); return; } ServerSource->FinishBurst(); Utils->DoOneToAllButSender(prefix, command, params, prefix); } else if (command == "ENCAP") { this->Encap(who, params); } else if (command == "NICK") { if (params.size() != 2) { SendError("Protocol violation: Wrong number of parameters for NICK message"); return; } if (IS_SERVER(who)) { SendError("Protocol violation: Server changing nick"); return; } if ((isdigit(params[0][0])) && (params[0] != who->uuid)) { SendError("Protocol violation: User changing nick to an invalid UID - " + params[0]); return; } /* Update timestamp on user when they change nicks */ who->age = atoi(params[1].c_str()); /* * On nick messages, check that the nick doesnt already exist here. * If it does, perform collision logic. */ User* x = ServerInstance->FindNickOnly(params[0]); if ((x) && (x != who)) { int collideret = 0; /* x is local, who is remote */ collideret = this->DoCollision(x, who->age, who->ident, who->GetIPString(), who->uuid); if (collideret != 1) { /* * Remote client lost, or both lost, parsing or passing on this * nickchange would be pointless, as the incoming client's server will * soon recieve SVSNICK to change its nick to its UID. :) -- w00t */ return; } } who->ForceNickChange(params[0].c_str()); Utils->RouteCommand(route_back_again, command, params, who); } else { Command* cmd = ServerInstance->Parser->GetHandler(command); if (!cmd) { irc::stringjoiner pmlist(" ", params, 0, params.size() - 1); ServerInstance->Logs->Log("m_spanningtree", SPARSE, "Unrecognised S2S command :%s %s %s", who->uuid.c_str(), command.c_str(), pmlist.GetJoined().c_str()); SendError("Unrecognised command '" + command + "' -- possibly loaded mismatched modules"); return; } if (params.size() < cmd->min_params) { irc::stringjoiner pmlist(" ", params, 0, params.size() - 1); ServerInstance->Logs->Log("m_spanningtree", SPARSE, "Insufficient parameters for S2S command :%s %s %s", who->uuid.c_str(), command.c_str(), pmlist.GetJoined().c_str()); SendError("Insufficient parameters for command '" + command + "'"); return; } if ((!params.empty()) && (params.back().empty()) && (!cmd->allow_empty_last_param)) { // 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 if (params.size()-1 < cmd->min_params) return; params.pop_back(); } CmdResult res = cmd->Handle(params, who); if (res == CMD_INVALID) { irc::stringjoiner pmlist(" ", params, 0, params.size() - 1); ServerInstance->Logs->Log("m_spanningtree", SPARSE, "Error handling S2S command :%s %s %s", who->uuid.c_str(), command.c_str(), pmlist.GetJoined().c_str()); SendError("Error handling '" + command + "' -- possibly loaded mismatched modules"); } else if (res == CMD_SUCCESS) Utils->RouteCommand(route_back_again, command, params, who); } } void TreeSocket::OnTimeout() { ServerInstance->SNO->WriteGlobalSno('l', "CONNECT: Connection to \002%s\002 timed out.", linkID.c_str()); } void TreeSocket::Close() { if (fd != -1) ServerInstance->GlobalCulls.AddItem(this); this->BufferedSocket::Close(); SetError("Remote host closed connection"); // Connection closed. // If the connection is fully up (state CONNECTED) // then propogate a netsplit to all peers. if (MyRoot) Squit(MyRoot,getError()); if (!ConnectionFailureShown) { ConnectionFailureShown = true; ServerInstance->SNO->WriteGlobalSno('l', "Connection to '\2%s\2' failed.",linkID.c_str()); time_t server_uptime = ServerInstance->Time() - this->age; if (server_uptime) { std::string timestr = Utils->Creator->TimeToStr(server_uptime); ServerInstance->SNO->WriteGlobalSno('l', "Connection to '\2%s\2' was established for %s", linkID.c_str(), timestr.c_str()); } } }