/* * 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 "main.h" #include "utils.h" #include "treeserver.h" #include "treesocket.h" #include "resolvers.h" #include "commands.h" /* Handle ERROR command */ void TreeSocket::Error(CommandBase::Params& params) { std::string msg = params.size() ? params[0] : ""; SetError("received ERROR " + msg); } void TreeSocket::Split(const std::string& line, std::string& prefix, std::string& command, CommandBase::Params& params) { irc::tokenstream tokens(line); if (!tokens.GetMiddle(prefix)) return; if (prefix[0] == ':') { prefix.erase(prefix.begin()); if (prefix.empty()) { this->SendError("BUG (?) Empty prefix received: " + line); return; } if (!tokens.GetMiddle(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.GetTrailing(param)) { params.push_back(param); } } void TreeSocket::ProcessLine(std::string &line) { std::string prefix; std::string command; CommandBase::Params params; ServerInstance->Logs->Log(MODNAME, LOG_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 = ConvToInt(params[0]); time_t delta = them - ServerInstance->Time(); if ((delta < -600) || (delta > 600)) { ServerInstance->SNO->WriteGlobalSno('l',"\2ERROR\2: Your clocks are out by %ld seconds (this is more than five minutes). Link aborted, \2PLEASE SYNC YOUR CLOCKS!\2",labs((long)delta)); SendError("Your clocks are out by "+ConvToStr(labs((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 %ld seconds. Please consider synching your clocks.", labs((long)delta)); } } // Check for duplicate server name/sid again, it's possible that a new // server was introduced while we were waiting for them to send BURST. // (we do not reserve their server name/sid when they send SERVER, we do it now) if (!CheckDuplicate(capab->name, capab->sid)) return; FinishAuth(capab->name, capab->sid, capab->description, capab->hidden); } 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; } } User* TreeSocket::FindSource(const std::string& prefix, const std::string& command) { // Empty prefix means the source is the directly connected server that sent this command if (prefix.empty()) return MyRoot->ServerUser; if (prefix.size() == 3) { // Prefix looks like a sid TreeServer* server = Utils->FindServerID(prefix); if (server) return server->ServerUser; } else { // If the prefix string is a uuid FindUUID() returns the appropriate User object User* user = ServerInstance->FindUUID(prefix); if (user) return user; } // Some implementations wrongly send a server name as prefix occasionally, handle that too for now TreeServer* const server = Utils->FindServer(prefix); if (server) return server->ServerUser; /* 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() == UIDGenerator::UUID_LENGTH) && (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. */ TreeServer* const usersserver = Utils->FindServerID(prefix.substr(0, 3)); if (usersserver) return usersserver->ServerUser; return this->MyRoot->ServerUser; } // Unknown prefix return NULL; } void TreeSocket::ProcessConnectedLine(std::string& prefix, std::string& command, CommandBase::Params& params) { User* who = FindSource(prefix, command); if (!who) { ServerInstance->Logs->Log(MODNAME, LOG_DEBUG, "Command '%s' from unknown prefix '%s'! Dropping entire command.", command.c_str(), prefix.c_str()); return; } /* * 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* const server = TreeServer::Get(who); if (server->GetSocket() != this) { ServerInstance->Logs->Log(MODNAME, LOG_DEBUG, "Protocol violation: Fake direction '%s' from connection '%s'", prefix.c_str(), linkID.c_str()); return; } // Translate commands coming from servers using an older protocol if (proto_version < ProtocolVersion) { if (!PreProcessOldProtocolMessage(who, command, params)) return; } ServerCommand* scmd = Utils->Creator->CmdManager.GetHandler(command); CommandBase* cmdbase = scmd; Command* cmd = NULL; if (!scmd) { // Not a special server-to-server command cmd = ServerInstance->Parser.GetHandler(command); if (!cmd) { if (command == "ERROR") { this->Error(params); return; } else if (command == "BURST") { // This is sent even when there is no need for it, drop it here for now return; } throw ProtocolException("Unknown command"); } cmdbase = cmd; } if (params.size() < cmdbase->min_params) throw ProtocolException("Insufficient parameters"); if ((!params.empty()) && (params.back().empty()) && (!cmdbase->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 < cmdbase->min_params) return; params.pop_back(); } CmdResult res; if (scmd) res = scmd->Handle(who, params); else { res = cmd->Handle(who, params); if (res == CMD_INVALID) throw ProtocolException("Error in command handler"); } if (res == CMD_SUCCESS) Utils->RouteCommand(server->GetRoute(), cmdbase, 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 < 0) return; 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) MyRoot->SQuit(getError()); 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 = ModuleSpanningTree::TimeToStr(server_uptime); ServerInstance->SNO->WriteGlobalSno('l', "Connection to '\2%s\2' was established for %s", linkID.c_str(), timestr.c_str()); } } void TreeSocket::FinishAuth(const std::string& remotename, const std::string& remotesid, const std::string& remotedesc, bool hidden) { this->LinkState = CONNECTED; Utils->timeoutlist.erase(this); linkID = remotename; MyRoot = new TreeServer(remotename, remotedesc, remotesid, Utils->TreeRoot, this, hidden); // Mark the server as bursting MyRoot->BeginBurst(); this->DoBurst(MyRoot); CommandServer::Builder(MyRoot).Forward(MyRoot); }