X-Git-Url: https://git.netwichtig.de/gitweb/?a=blobdiff_plain;f=src%2Fmodules%2Fm_ident.cpp;h=0f746b05b1e0340f4f863c3260f8233fa7b0796f;hb=HEAD;hp=9272c50549aa38e6e5043802a06ba730945300e0;hpb=9ca3a5fdad9c865b990540f30315e69fed03546a;p=user%2Fhenk%2Fcode%2Finspircd.git diff --git a/src/modules/m_ident.cpp b/src/modules/m_ident.cpp index 9272c5054..0f746b05b 100644 --- a/src/modules/m_ident.cpp +++ b/src/modules/m_ident.cpp @@ -1,299 +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 "inspircd.h" -#include "users.h" -#include "channels.h" -#include "modules.h" -/* $ModDesc: Provides support for RFC1413 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, + + // Ident looups are not enabled and a user has been an insecure ident prefix. + IDENT_PREFIXED, + + // 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 IdentRequestSocket : public InspSocket +class IdentRequestSocket : public EventHandler { - private: - userrec *user; - int original_fd; public: - IdentRequestSocket(InspIRCd *Server, userrec *user, int timeout, const std::string &bindip) - : InspSocket(Server, user->GetIPString(), 113, false, timeout, bindip), user(user) - { - original_fd = user->GetFd(); - Instance->Log(DEBUG, "Ident request against user with fd %d", original_fd); - } + 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 */ - virtual bool OnConnected() + IdentRequestSocket(LocalUser* u) : user(u) { - if (Instance->SE->GetRef(original_fd) == user) + age = ServerInstance->Time(); + + 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) + { + bindaddr.in6.sin6_port = 0; + connaddr.in6.sin6_port = htons(113); + } + else { - Instance->Log(DEBUG,"Oh dear, our user has gone AWOL on fd %d", original_fd); - return false; + bindaddr.in4.sin_port = 0; + connaddr.in4.sin_port = htons(113); } - /* Both sockaddr_in and sockaddr_in6 can be safely casted to sockaddr, especially since the - * only members we use are in a part of the struct that should always be identical (at the - * byte level). */ - - Instance->Log(DEBUG, "Sending ident request to %s", user->GetIPString()); - - #ifndef IPV6 - sockaddr_in laddr, raddr; - #else - sockaddr_in6 laddr, raddr; - #endif - - socklen_t laddrsz = sizeof(laddr); - socklen_t raddrsz = sizeof(raddr); - - if ((getsockname(user->GetFd(), (sockaddr*) &laddr, &laddrsz) != 0) || (getpeername(user->GetFd(), (sockaddr*) &raddr, &raddrsz) != 0)) + /* Attempt to bind (ident requests must come from the ip the query is referring to */ + if (SocketEngine::Bind(GetFd(), bindaddr) < 0) { - // Error - TidyUser(); - return false; + this->Close(); + throw ModuleException("failed to bind()"); } - - char req[32]; - - #ifndef IPV6 - snprintf(req, sizeof(req), "%d,%d\r\n", ntohs(raddr.sin_port), ntohs(laddr.sin_port)); - #else - snprintf(req, sizeof(req), "%d,%d\r\n", ntohs(raddr.sin6_port), ntohs(laddr.sin6_port)); - #endif - - this->Write(req); - - return true; - } - virtual void OnClose() - { - /* There used to be a check against the fd table here, to make sure the user hadn't been - * deleted but not yet had their socket closed or something along those lines, dated june - * 2006. Since we added the global cull list and such, I don't *think* that is necessary - * - * -- YES IT IS!!!! DO NOT REMOVE IT, THIS IS WHAT THE WARNING ABOVE THE OLD CODE SAID :P - */ - if (Instance->SE->GetRef(original_fd) == user) + SocketEngine::NonBlocking(GetFd()); + + /* Attempt connection (nonblocking) */ + if (SocketEngine::Connect(this, connaddr) == -1 && errno != EINPROGRESS) { - Instance->Log(DEBUG,"Oh dear, our user has gone AWOL on fd %d", original_fd); - return; + this->Close(); + throw ModuleException("connect() failed"); } - if (*user->ident == '~' && user->GetExt("ident_socket")) - user->WriteServ("NOTICE Auth :*** Could not find your ident, using %s instead", user->ident); + /* Add fd to socket engine */ + if (!SocketEngine::AddFd(this, FD_WANT_NO_READ | FD_WANT_POLL_WRITE)) + { + this->Close(); + throw ModuleException("out of fds"); + } + } + + 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)); - TidyUser(); - Instance->next_call = Instance->Time(); + /* 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; } - - virtual void OnError(InspSocketError e) + + void Close() { - if (Instance->SE->GetRef(original_fd) == user) + /* 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()) { - Instance->Log(DEBUG,"Oh dear, our user has gone AWOL on fd %d", original_fd); - return; + ServerInstance->Logs->Log(MODNAME, LOG_DEBUG, "Close ident socket %d", GetFd()); + SocketEngine::Close(this); } + } - // Quick check to make sure that this hasn't been sent ;) - if (*user->ident == '~' && user->GetExt("ident_socket")) - user->WriteServ("NOTICE Auth :*** Could not find your ident, using %s instead", user->ident); - - TidyUser(); - Instance->next_call = Instance->Time(); + bool HasResult() + { + return done; } - - virtual bool OnDataReady() + + void OnEventHandlerRead() CXX11_OVERRIDE { - if (Instance->SE->GetRef(original_fd) == user) - { - Instance->Log(DEBUG,"Oh dear, our user has gone AWOL on fd %d", original_fd); - return false; - } + /* 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); - char *ibuf = this->Read(); - if (!ibuf) - { - TidyUser(); - return false; - } - - // 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 - - irc::sepstream sep(ibuf, ':'); - std::string token; - for (int i = 0; sep.GetToken(token); i++) + /* 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) { - // We only really care about the 4th portion - if (i < 3) + if (result.size() == ServerInstance->Config->Limits.IdentMax) + /* Ident is getting too long */ + break; + + if (*i == ' ') continue; - - char ident[IDENTMAX + 2]; - - // Truncate the ident at any characters we don't like, skip leading spaces - int k = 0; - for (const char *j = token.c_str(); *j && (k < IDENTMAX + 1); j++) + + /* 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)) { - if (*j == ' ') - continue; - - // Rules taken from InspIRCd::IsIdent - if (((*j >= 'A') && (*j <= '}')) || ((*j >= '0') && (*j <= '9')) || (*j == '-') || (*j == '.')) - { - ident[k++] = *j; - continue; - } - + result.erase(result.end()-1); break; } - - ident[k] = '\0'; - - // Redundant check with IsIdent, in case that changes and this doesn't (paranoia!) - if (*ident && Instance->IsIdent(ident)) - { - strlcpy(user->ident, ident, IDENTMAX); - user->WriteServ("NOTICE Auth :*** Found your ident: %s", user->ident); - Instance->next_call = Instance->Time(); - } - - break; } + } - TidyUser(); - return false; + void OnEventHandlerError(int errornum) CXX11_OVERRIDE + { + Close(); + done = true; } - void TidyUser() + CullResult cull() CXX11_OVERRIDE { - user->Shrink("ident_socket"); - int* delfd; - if (user->GetExt("ident_socket_fd", delfd)) - { - delete delfd; - user->Shrink("ident_socket_fd"); - } + Close(); + return EventHandler::cull(); } }; class ModuleIdent : public Module { private: - int RequestTimeout; - public: - ModuleIdent(InspIRCd *Me) - : Module(Me) - { - OnRehash(NULL, ""); - } - - virtual ~ModuleIdent() + unsigned int timeout; + bool prefixunqueried; + SimpleExtItem socket; + LocalIntExt state; + + static void PrefixIdent(LocalUser* user) { + // 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); } - - virtual Version GetVersion() + + public: + ModuleIdent() + : socket("ident_socket", ExtensionItem::EXT_USER, this) + , state("ident_state", ExtensionItem::EXT_USER, this) { - return Version(1, 1, 1, 0, VF_VENDOR, API_VERSION); } - - virtual void Implements(char *List) + + Version GetVersion() CXX11_OVERRIDE { - List[I_OnRehash] = List[I_OnUserRegister] = List[I_OnCheckReady] = List[I_OnCleanup] = 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 ¶m) + + void ReadConfig(ConfigStatus& status) CXX11_OVERRIDE { - ConfigReader MyConf(ServerInstance); - - RequestTimeout = MyConf.ReadInteger("ident", "timeout", 0, true); - if (!RequestTimeout) - RequestTimeout = 5; + 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 { - /* userrec::ident is currently the username field from USER; with m_ident loaded, that - * should be preceded by a ~. The field is actually IDENTMAX+2 characters wide. */ - memmove(user->ident + 1, user->ident, IDENTMAX); - user->ident[0] = '~'; - // Ensure that it is null terminated - user->ident[IDENTMAX + 1] = '\0'; - - user->WriteServ("NOTICE Auth :*** Looking up your ident..."); - - // Get the IP that the user is connected to, and bind to that for the outgoing connection - #ifndef IPV6 - sockaddr_in laddr; - #else - sockaddr_in6 laddr; - #endif - socklen_t laddrsz = sizeof(laddr); - - if (getsockname(user->GetFd(), (sockaddr*) &laddr, &laddrsz) != 0) + IdentRequestSocket* isock = socket.get(user); + if (isock) + { + // If an ident lookup request was in progress then cancel it. + isock->Close(); + socket.unset(user); + } + + // 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)) { - user->WriteServ("NOTICE Auth :*** Could not find your ident, using %s instead.", user->ident); - return 0; + state.set(user, IDENT_SKIPPED); + return; } - - #ifndef IPV6 - const char *ip = inet_ntoa(laddr.sin_addr); - #else - char ip[INET6_ADDRSTRLEN + 1]; - inet_ntop(laddr.sin6_family, &laddr.sin6_addr, ip, INET6_ADDRSTRLEN); - #endif - - IdentRequestSocket *isock = new IdentRequestSocket(ServerInstance, user, RequestTimeout, ip); - if (isock->GetFd() > -1) + + user->WriteNotice("*** Looking up your ident..."); + + try { - user->Extend("ident_socket_fd", new int(isock->GetFd())); - user->Extend("ident_socket", isock); + isock = new IdentRequestSocket(user); + socket.set(user, isock); + } + catch (ModuleException &e) + { + ServerInstance->Logs->Log(MODNAME, LOG_DEBUG, "Ident exception: " + e.GetReason()); } - else - if (ServerInstance->SocketCull.find(isock) == ServerInstance->SocketCull.end()) - ServerInstance->SocketCull[isock] = isock; - return 0; - } - - virtual bool OnCheckReady(userrec *user) - { - return (!user->GetExt("ident_socket")); } - - 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) { - IdentRequestSocket *isock; - userrec *user = (userrec*)item; - if (user->GetExt("ident_socket", isock)) + if (prefixunqueried && state.get(user) == IDENT_SKIPPED) { - int *fd; - if (user->GetExt("ident_socket_fd", fd) && (ServerInstance->SE->GetRef(*fd) == isock)) - isock->Close(); + PrefixIdent(user); + state.set(user, IDENT_PREFIXED); } + return MOD_RES_PASSTHRU; } + + time_t compare = isock->age + timeout; + + /* Check for timeout of the socket */ + if (ServerInstance->Time() >= compare) + { + /* 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; + } + + /* 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; } - - virtual void OnUserDisconnect(userrec *user) + + ModResult OnSetConnectClass(LocalUser* user, ConnectClass* myclass) CXX11_OVERRIDE { - IdentRequestSocket *isock; - if (user->GetExt("ident_socket", isock)) + if (myclass->config->getBool("requireident") && state.get(user) != IDENT_FOUND) { - int *fd; - if (user->GetExt("ident_socket_fd", fd) && (ServerInstance->SE->GetRef(*fd) == isock)) - isock->Close(); + 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; } -}; -MODULE_INIT(ModuleIdent); + void OnUserConnect(LocalUser* user) CXX11_OVERRIDE + { + // Clear this as it is no longer necessary. + state.unset(user); + } +}; +MODULE_INIT(ModuleIdent)