X-Git-Url: https://git.netwichtig.de/gitweb/?a=blobdiff_plain;f=src%2Fmodules%2Fm_ident.cpp;h=0f746b05b1e0340f4f863c3260f8233fa7b0796f;hb=HEAD;hp=6c7d36974d4a726138527ee6c2b21b98d791fec4;hpb=0b460e6f324aa72cdbfb4143918971d582f62a77;p=user%2Fhenk%2Fcode%2Finspircd.git diff --git a/src/modules/m_ident.cpp b/src/modules/m_ident.cpp index 6c7d36974..0f746b05b 100644 --- a/src/modules/m_ident.cpp +++ b/src/modules/m_ident.cpp @@ -1,327 +1,428 @@ -/* +------------------------------------+ - * | Inspire Internet Relay Chat Daemon | - * +------------------------------------+ +/* + * InspIRCd -- Internet Relay Chat Daemon * - * InspIRCd: (C) 2002-2007 InspIRCd Development Team - * See: http://www.inspircd.org/wiki/index.php/Credits + * Copyright (C) 2013, 2018-2020 Sadie Powell + * Copyright (C) 2012-2015 Attila Molnar + * Copyright (C) 2012-2013 Robby + * Copyright (C) 2009-2010 Daniel De Graaf + * Copyright (C) 2008 Robin Burchell + * Copyright (C) 2007 John Brooks + * Copyright (C) 2007 Dennis Friis + * Copyright (C) 2005, 2007, 2010 Craig Edwards * - * This program is free but copyrighted software; see - * the file COPYING for details. + * 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 -#include -#include "users.h" -#include "channels.h" -#include "modules.h" + #include "inspircd.h" -/* $ModDesc: Provides support for RFC 1413 ident lookups */ +enum +{ + // Either the ident looup has not started yet or the user is registered. + IDENT_UNKNOWN = 0, + + // Ident lookups are not enabled and a user has been marked as being skipped. + IDENT_SKIPPED, -// Version 1.5.0.0 - Updated to use InspSocket, faster and neater. + // Ident looups are not enabled and a user has been an insecure ident prefix. + IDENT_PREFIXED, -/** Handles RFC1413 ident connections to users + // An ident lookup was done and an ident was found. + IDENT_FOUND, + + // An ident lookup was done but no ident was found + IDENT_MISSING +}; + +/* -------------------------------------------------------------- + * Note that this is the third incarnation of m_ident. The first + * two attempts were pretty crashy, mainly due to the fact we tried + * to use InspSocket/BufferedSocket to make them work. This class + * is ok for more heavyweight tasks, it does a lot of things behind + * the scenes that are not good for ident sockets and it has a huge + * memory footprint! + * + * To fix all the issues that we had in the old ident modules (many + * nasty race conditions that would cause segfaults etc) we have + * rewritten this module to use a simplified socket object based + * directly off EventHandler. As EventHandler only has low level + * readability, writeability and error events tied directly to the + * socket engine, this makes our lives easier as nothing happens to + * our ident lookup class that is outside of this module, or out- + * side of the control of the class. There are no timers, internal + * events, or such, which will cause the socket to be deleted, + * queued for deletion, etc. In fact, there's not even any queueing! + * + * Using this framework we have a much more stable module. + * + * A few things to note: + * + * O The only place that may *delete* an active or inactive + * ident socket is OnUserDisconnect in the module class. + * Because this is out of scope of the socket class there is + * no possibility that the socket may ever try to delete + * itself. + * + * O Closure of the ident socket with the Close() method will + * not cause removal of the socket from memory or detatchment + * from its 'parent' User class. It will only flag it as an + * inactive socket in the socket engine. + * + * O Timeouts are handled in OnCheckReaady at the same time as + * checking if the ident socket has a result. This is done + * by checking if the age the of the class (its instantiation + * time) plus the timeout value is greater than the current time. + * + * O The ident socket is able to but should not modify its + * 'parent' user directly. Instead the ident socket class sets + * a completion flag and during the next call to OnCheckReady, + * the completion flag will be checked and any result copied to + * that user's class. This again ensures a single point of socket + * deletion for safer, neater code. + * + * O The code in the constructor of the ident socket is taken from + * BufferedSocket but majorly thinned down. It works for both + * IPv4 and IPv6. + * + * O In the event that the ident socket throws a ModuleException, + * nothing is done. This is counted as total and complete + * failure to create a connection. + * -------------------------------------------------------------- */ -class RFC1413 : public InspSocket + +class IdentRequestSocket : public EventHandler { - protected: - socklen_t uslen; // length of our port number - socklen_t themlen; // length of their port number - char ident_request[128]; // buffer used to make up the request string public: + LocalUser *user; /* User we are attached to */ + std::string result; /* Holds the ident string if done */ + time_t age; + bool done; /* True if lookup is finished */ - userrec* u; // user record that the lookup is associated with - int ufd; - - RFC1413(InspIRCd* SI, userrec* user, int maxtime) : InspSocket(SI, user->GetIPString(), 113, false, maxtime), u(user) + IdentRequestSocket(LocalUser* u) : user(u) { - ufd = user->GetFd(); - } + age = ServerInstance->Time(); - virtual void OnTimeout() - { - // When we timeout, the connection failed within the allowed timeframe, - // so we just display a notice, and tidy off the ident_data. - if (u && (Instance->SE->GetRef(ufd) == u)) + SetFd(socket(user->server_sa.family(), SOCK_STREAM, 0)); + if (!HasFd()) + throw ModuleException("Could not create socket"); + + done = false; + + irc::sockets::sockaddrs bindaddr; + irc::sockets::sockaddrs connaddr; + + memcpy(&bindaddr, &user->server_sa, sizeof(bindaddr)); + memcpy(&connaddr, &user->client_sa, sizeof(connaddr)); + + if (connaddr.family() == AF_INET6) { - char newident[MAXBUF]; - u->Shrink("ident_data"); - u->WriteServ("NOTICE "+std::string(u->nick)+" :*** Could not find your ident, using ~"+std::string(u->ident)+" instead."); - strcpy(newident,"~"); - strlcat(newident,u->ident,IDENTMAX); - strlcpy(u->ident,newident,IDENTMAX); + bindaddr.in6.sin6_port = 0; + connaddr.in6.sin6_port = htons(113); + } + else + { + bindaddr.in4.sin_port = 0; + connaddr.in4.sin_port = htons(113); } - } - virtual bool OnDataReady() - { - char* ibuf = this->Read(); - if (ibuf) + /* Attempt to bind (ident requests must come from the ip the query is referring to */ + if (SocketEngine::Bind(GetFd(), bindaddr) < 0) { - char* savept; - char* section = strtok_r(ibuf,":",&savept); - while (section) - { - if (strstr(section,"USERID")) - { - section = strtok_r(NULL,":",&savept); - if (section) - { - // ID type, usually UNIX or OTHER... we dont want it, so read the next token - section = strtok_r(NULL,":",&savept); - if (section) - { - while (*section == ' ') section++; // strip leading spaces - for (char* j = section; *j; j++) - if ((*j < 33) || (*j > 126)) - *j = '\0'; // truncate at invalid chars - if (*section) - { - if (u && (Instance->SE->GetRef(ufd) == u)) - { - if (this->Instance->IsIdent(section)) - { - strlcpy(u->ident,section,IDENTMAX); - u->WriteServ("NOTICE "+std::string(u->nick)+" :*** Found your ident: "+std::string(u->ident)); - } - } - } - return false; - } - } - } - section = strtok_r(NULL,":",&savept); - } + this->Close(); + throw ModuleException("failed to bind()"); } - return false; - } - virtual void OnClose() - { - // tidy up after ourselves when the connection is done. - // We receive this event straight after a timeout, too. - // - // - // OK, now listen up. The weird looking check here is - // REQUIRED. Don't try and optimize it away. - // - // When a socket is closed, it is not immediately removed - // from the socket list, there can be a short delay - // before it is culled from the list. This means that - // without this check, there is a chance that a user - // may not exist when we come to ::Shrink them, which - // results in a segfault. The value of "u" may not - // always be NULL at this point, so, what we do is - // check against the fd_ref_table, to see if (1) the user - // exists, and (2) its the SAME user, on the same file - // descriptor that they were when the lookup began. - // - // Fixes issue reported by webs, 7 Jun 2006 - if (u && (Instance->SE->GetRef(ufd) == u)) + SocketEngine::NonBlocking(GetFd()); + + /* Attempt connection (nonblocking) */ + if (SocketEngine::Connect(this, connaddr) == -1 && errno != EINPROGRESS) + { + this->Close(); + throw ModuleException("connect() failed"); + } + + /* Add fd to socket engine */ + if (!SocketEngine::AddFd(this, FD_WANT_NO_READ | FD_WANT_POLL_WRITE)) { - u->Shrink("ident_data"); + this->Close(); + throw ModuleException("out of fds"); } } - virtual void OnError(InspSocketError e) + void OnEventHandlerWrite() CXX11_OVERRIDE + { + SocketEngine::ChangeEventMask(this, FD_WANT_POLL_READ | FD_WANT_NO_WRITE); + + char req[32]; + + /* Build request in the form 'localport,remoteport\r\n' */ + int req_size; + if (user->client_sa.family() == AF_INET6) + req_size = snprintf(req, sizeof(req), "%d,%d\r\n", + ntohs(user->client_sa.in6.sin6_port), ntohs(user->server_sa.in6.sin6_port)); + else + req_size = snprintf(req, sizeof(req), "%d,%d\r\n", + ntohs(user->client_sa.in4.sin_port), ntohs(user->server_sa.in4.sin_port)); + + /* Send failed if we didnt write the whole ident request -- + * might as well give up if this happens! + */ + if (SocketEngine::Send(this, req, req_size, 0) < req_size) + done = true; + } + + void Close() { - if (u && (Instance->SE->GetRef(ufd) == u)) + /* Remove ident socket from engine, and close it, but dont detach it + * from its parent user class, or attempt to delete its memory. + */ + if (HasFd()) { - u->Shrink("ident_data"); + ServerInstance->Logs->Log(MODNAME, LOG_DEBUG, "Close ident socket %d", GetFd()); + SocketEngine::Close(this); } } - virtual bool OnConnected() + bool HasResult() { - if (u && (Instance->SE->GetRef(ufd) == u)) + return done; + } + + void OnEventHandlerRead() CXX11_OVERRIDE + { + /* We don't really need to buffer for incomplete replies here, since IDENT replies are + * extremely short - there is *no* sane reason it'd be in more than one packet + */ + char ibuf[256]; + int recvresult = SocketEngine::Recv(this, ibuf, sizeof(ibuf)-1, 0); + + /* Close (but don't delete from memory) our socket + * and flag as done since the ident lookup has finished + */ + Close(); + done = true; + + /* Cant possibly be a valid response shorter than 3 chars, + * because the shortest possible response would look like: '1,1' + */ + if (recvresult < 3) + return; + + ServerInstance->Logs->Log(MODNAME, LOG_DEBUG, "ReadResponse()"); + + /* Truncate at the first null character, but first make sure + * there is at least one null char (at the end of the buffer). + */ + ibuf[recvresult] = '\0'; + std::string buf(ibuf); + + /* <2 colons: invalid + * 2 colons: reply is an error + * >3 colons: there is a colon in the ident + */ + if (std::count(buf.begin(), buf.end(), ':') != 3) + return; + + std::string::size_type lastcolon = buf.rfind(':'); + + /* Truncate the ident at any characters we don't like, skip leading spaces */ + for (std::string::const_iterator i = buf.begin()+lastcolon+1; i != buf.end(); ++i) { - sockaddr* sock_us = new sockaddr; - sockaddr* sock_them = new sockaddr; - bool success = false; - uslen = sizeof(sockaddr_in); - themlen = sizeof(sockaddr_in); -#ifdef IPV6 - if (this->u->GetAddressFamily() == AF_INET6) - { - themlen = sizeof(sockaddr_in6); - uslen = sizeof(sockaddr_in6); - success = ((getsockname(this->u->GetFd(),sock_us,&uslen) || getpeername(this->u->GetFd(), sock_them, &themlen))); - } - else - success = ((getsockname(this->u->GetFd(),sock_us,&uslen) || getpeername(this->u->GetFd(), sock_them, &themlen))); -#else - success = ((getsockname(this->u->GetFd(),sock_us,&uslen) || getpeername(this->u->GetFd(), sock_them, &themlen))); -#endif - if (success) - { - Instance->Log(DEBUG,"BUG: Ident: failed to get socket names"); - return false; - } - else + if (result.size() == ServerInstance->Config->Limits.IdentMax) + /* Ident is getting too long */ + break; + + if (*i == ' ') + continue; + + /* Add the next char to the result and see if it's still a valid ident, + * according to IsIdent(). If it isn't, then erase what we just added and + * we're done. + */ + result += *i; + if (!ServerInstance->IsIdent(result)) { - // send the request in the following format: theirsocket,oursocket -#ifdef IPV6 - if (this->u->GetAddressFamily() == AF_INET6) - snprintf(ident_request,127,"%d,%d\r\n",ntohs(((sockaddr_in6*)sock_them)->sin6_port),ntohs(((sockaddr_in6*)sock_us)->sin6_port)); - else - snprintf(ident_request,127,"%d,%d\r\n",ntohs(((sockaddr_in*)sock_them)->sin_port),ntohs(((sockaddr_in*)sock_us)->sin_port)); -#else - snprintf(ident_request,127,"%d,%d\r\n",ntohs(((sockaddr_in*)sock_them)->sin_port),ntohs(((sockaddr_in*)sock_us)->sin_port)); -#endif - this->Write(ident_request); - return true; + result.erase(result.end()-1); + break; } } - else - { - return true; - } + } + + void OnEventHandlerError(int errornum) CXX11_OVERRIDE + { + Close(); + done = true; + } + + CullResult cull() CXX11_OVERRIDE + { + Close(); + return EventHandler::cull(); } }; class ModuleIdent : public Module { + private: + unsigned int timeout; + bool prefixunqueried; + SimpleExtItem socket; + LocalIntExt state; - ConfigReader* Conf; - - int IdentTimeout; - - public: - void ReadSettings() + static void PrefixIdent(LocalUser* user) { - Conf = new ConfigReader(ServerInstance); - IdentTimeout = Conf->ReadInteger("ident","timeout",0,true); - if (!IdentTimeout) - IdentTimeout = 1; - DELETE(Conf); + // Check that they haven't been prefixed already. + if (user->ident[0] == '~') + return; + + // All invalid usernames are prefixed with a tilde. + std::string newident(user->ident); + newident.insert(newident.begin(), '~'); + + // If the username is too long then truncate it. + if (newident.length() > ServerInstance->Config->Limits.IdentMax) + newident.erase(ServerInstance->Config->Limits.IdentMax); + + // Apply the new username. + user->ChangeIdent(newident); } - ModuleIdent(InspIRCd* Me) - : Module::Module(Me) + public: + ModuleIdent() + : socket("ident_socket", ExtensionItem::EXT_USER, this) + , state("ident_state", ExtensionItem::EXT_USER, this) { - - ReadSettings(); } - void Implements(char* List) + Version GetVersion() CXX11_OVERRIDE { - List[I_OnCleanup] = List[I_OnRehash] = List[I_OnUserRegister] = List[I_OnCheckReady] = List[I_OnUserDisconnect] = 1; + return Version("Allows the usernames (idents) of users to be looked up using the RFC 1413 Identification Protocol.", VF_VENDOR); } - virtual void OnRehash(userrec* user, const std::string ¶meter) + void ReadConfig(ConfigStatus& status) CXX11_OVERRIDE { - ReadSettings(); + ConfigTag* tag = ServerInstance->Config->ConfValue("ident"); + timeout = tag->getDuration("timeout", 5, 1, 60); + prefixunqueried = tag->getBool("prefixunqueried"); } - virtual int OnUserRegister(userrec* user) + void OnSetUserIP(LocalUser* user) CXX11_OVERRIDE { - /* - * when the new user connects, before they authenticate with USER/NICK/PASS, we do - * their ident lookup. We do this by instantiating an object of type RFC1413, which - * is derived from InspSocket, and inserting it into the socket engine using the - * Server::AddSocket() call. - */ - user->WriteServ("NOTICE "+std::string(user->nick)+" :*** Looking up your ident..."); - RFC1413* ident = new RFC1413(ServerInstance, user, IdentTimeout); - if ((ident->GetState() == I_CONNECTING) || (ident->GetState() == I_CONNECTED)) + IdentRequestSocket* isock = socket.get(user); + if (isock) { - user->Extend("ident_data", (char*)ident); + // If an ident lookup request was in progress then cancel it. + isock->Close(); + socket.unset(user); } - else + + // The ident protocol requires that clients are connecting over a protocol with ports. + if (user->client_sa.family() != AF_INET && user->client_sa.family() != AF_INET6) + return; + + // We don't want to look this up once the user has connected. + if (user->registered == REG_ALL || user->quitting) + return; + + ConfigTag* tag = user->MyClass->config; + if (!tag->getBool("useident", true)) { - char newident[MAXBUF]; - user->WriteServ("NOTICE "+std::string(user->nick)+" :*** Could not find your ident, using ~"+std::string(user->ident)+" instead."); - strcpy(newident,"~"); - strlcat(newident,user->ident,IDENTMAX); - strlcpy(user->ident,newident,IDENTMAX); - delete ident; + state.set(user, IDENT_SKIPPED); + return; } - return 0; - } - virtual bool OnCheckReady(userrec* user) - { - /* - * The socket engine will clean up their ident request for us when it completes, - * either due to timeout or due to closing, so, we just hold them until they dont - * have an ident field any more. - */ - RFC1413* ident; - return (!user->GetExt("ident_data", ident)); + user->WriteNotice("*** Looking up your ident..."); + + try + { + isock = new IdentRequestSocket(user); + socket.set(user, isock); + } + catch (ModuleException &e) + { + ServerInstance->Logs->Log(MODNAME, LOG_DEBUG, "Ident exception: " + e.GetReason()); + } } - virtual void OnCleanup(int target_type, void* item) + /* This triggers pretty regularly, we can use it in preference to + * creating a Timer object and especially better than creating a + * Timer per ident lookup! + */ + ModResult OnCheckReady(LocalUser *user) CXX11_OVERRIDE { - if (target_type == TYPE_USER) + /* Does user have an ident socket attached at all? */ + IdentRequestSocket* isock = socket.get(user); + if (!isock) { - userrec* user = (userrec*)item; - RFC1413* ident; - if (user->GetExt("ident_data", ident)) + if (prefixunqueried && state.get(user) == IDENT_SKIPPED) { - // FIX: If the user record is deleted, the socket wont be removed - // immediately so there is chance of the socket trying to write to - // a user which has now vanished! To prevent this, set ident::u - // to NULL and check it so that we dont write users who have gone away. - ident->u = NULL; - ServerInstance->SE->DelFd(ident); - delete ident; + PrefixIdent(user); + state.set(user, IDENT_PREFIXED); } + return MOD_RES_PASSTHRU; } - } - virtual void OnUserDisconnect(userrec* user) - { - /* - * when the user quits tidy up any ident lookup they have pending to keep things tidy. - * When we call RemoveSocket, the abstractions tied into the system evnetually work their - * way to RFC1459::OnClose(), which shrinks off the ident_data for us, so we dont need - * to do it here. If we don't tidy this up, there may still be lingering idents for users - * who have quit, as class RFC1459 is only loosely bound to userrec* via a pair of pointers - * and this would leave at least one of the invalid ;) - */ - RFC1413* ident; - if (user->GetExt("ident_data", ident)) + time_t compare = isock->age + timeout; + + /* Check for timeout of the socket */ + if (ServerInstance->Time() >= compare) { - ident->u = NULL; - ServerInstance->SE->DelFd(ident); - delete ident; + /* Ident timeout */ + state.set(user, IDENT_MISSING); + PrefixIdent(user); + user->WriteNotice("*** Ident lookup timed out, using " + user->ident + " instead."); + } + else if (!isock->HasResult()) + { + // time still good, no result yet... hold the registration + return MOD_RES_DENY; } - } - - virtual ~ModuleIdent() - { - } - - virtual Version GetVersion() - { - return Version(1,1,0,0,VF_VENDOR,API_VERSION); - } - -}; -class ModuleIdentFactory : public ModuleFactory -{ - public: - ModuleIdentFactory() - { + /* wooo, got a result (it will be good, or bad) */ + else if (isock->result.empty()) + { + state.set(user, IDENT_MISSING); + PrefixIdent(user); + user->WriteNotice("*** Could not find your ident, using " + user->ident + " instead."); + } + else + { + state.set(user, IDENT_FOUND); + user->ChangeIdent(isock->result); + user->WriteNotice("*** Found your ident, '" + user->ident + "'"); + } + + isock->Close(); + socket.unset(user); + return MOD_RES_PASSTHRU; } - - ~ModuleIdentFactory() + + ModResult OnSetConnectClass(LocalUser* user, ConnectClass* myclass) CXX11_OVERRIDE { + if (myclass->config->getBool("requireident") && state.get(user) != IDENT_FOUND) + { + ServerInstance->Logs->Log("CONNECTCLASS", LOG_DEBUG, "The %s connect class is not suitable as it requires an identd response", + myclass->GetName().c_str()); + return MOD_RES_DENY; + } + return MOD_RES_PASSTHRU; } - - virtual Module * CreateModule(InspIRCd* Me) + + void OnUserConnect(LocalUser* user) CXX11_OVERRIDE { - return new ModuleIdent(Me); + // Clear this as it is no longer necessary. + state.unset(user); } - }; - -extern "C" void * init_module( void ) -{ - return new ModuleIdentFactory; -} - +MODULE_INIT(ModuleIdent)