2 * InspIRCd -- Internet Relay Chat Daemon
4 * Copyright (C) 2013, 2018-2020 Sadie Powell <sadie@witchery.services>
5 * Copyright (C) 2012-2015 Attila Molnar <attilamolnar@hush.com>
6 * Copyright (C) 2012-2013 Robby <robby@chatbelgie.be>
7 * Copyright (C) 2009-2010 Daniel De Graaf <danieldg@inspircd.org>
8 * Copyright (C) 2008 Robin Burchell <robin+git@viroteck.net>
9 * Copyright (C) 2007, 2010 Craig Edwards <brain@inspircd.org>
10 * Copyright (C) 2007 John Brooks <special@inspircd.org>
11 * Copyright (C) 2007 Dennis Friis <peavey@inspircd.org>
13 * This file is part of InspIRCd. InspIRCd is free software: you can
14 * redistribute it and/or modify it under the terms of the GNU General Public
15 * License as published by the Free Software Foundation, version 2.
17 * This program is distributed in the hope that it will be useful, but WITHOUT
18 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
19 * FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
22 * You should have received a copy of the GNU General Public License
23 * along with this program. If not, see <http://www.gnu.org/licenses/>.
31 // Either the ident looup has not started yet or the user is registered.
34 // Ident lookups are not enabled and a user has been marked as being skipped.
37 // Ident looups are not enabled and a user has been an insecure ident prefix.
40 // An ident lookup was done and an ident was found.
43 // An ident lookup was done but no ident was found
47 /* --------------------------------------------------------------
48 * Note that this is the third incarnation of m_ident. The first
49 * two attempts were pretty crashy, mainly due to the fact we tried
50 * to use InspSocket/BufferedSocket to make them work. This class
51 * is ok for more heavyweight tasks, it does a lot of things behind
52 * the scenes that are not good for ident sockets and it has a huge
55 * To fix all the issues that we had in the old ident modules (many
56 * nasty race conditions that would cause segfaults etc) we have
57 * rewritten this module to use a simplified socket object based
58 * directly off EventHandler. As EventHandler only has low level
59 * readability, writeability and error events tied directly to the
60 * socket engine, this makes our lives easier as nothing happens to
61 * our ident lookup class that is outside of this module, or out-
62 * side of the control of the class. There are no timers, internal
63 * events, or such, which will cause the socket to be deleted,
64 * queued for deletion, etc. In fact, there's not even any queueing!
66 * Using this framework we have a much more stable module.
68 * A few things to note:
70 * O The only place that may *delete* an active or inactive
71 * ident socket is OnUserDisconnect in the module class.
72 * Because this is out of scope of the socket class there is
73 * no possibility that the socket may ever try to delete
76 * O Closure of the ident socket with the Close() method will
77 * not cause removal of the socket from memory or detatchment
78 * from its 'parent' User class. It will only flag it as an
79 * inactive socket in the socket engine.
81 * O Timeouts are handled in OnCheckReaady at the same time as
82 * checking if the ident socket has a result. This is done
83 * by checking if the age the of the class (its instantiation
84 * time) plus the timeout value is greater than the current time.
86 * O The ident socket is able to but should not modify its
87 * 'parent' user directly. Instead the ident socket class sets
88 * a completion flag and during the next call to OnCheckReady,
89 * the completion flag will be checked and any result copied to
90 * that user's class. This again ensures a single point of socket
91 * deletion for safer, neater code.
93 * O The code in the constructor of the ident socket is taken from
94 * BufferedSocket but majorly thinned down. It works for both
97 * O In the event that the ident socket throws a ModuleException,
98 * nothing is done. This is counted as total and complete
99 * failure to create a connection.
100 * --------------------------------------------------------------
103 class IdentRequestSocket : public EventHandler
106 LocalUser *user; /* User we are attached to */
107 std::string result; /* Holds the ident string if done */
109 bool done; /* True if lookup is finished */
111 IdentRequestSocket(LocalUser* u) : user(u)
113 age = ServerInstance->Time();
115 SetFd(socket(user->server_sa.family(), SOCK_STREAM, 0));
117 throw ModuleException("Could not create socket");
121 irc::sockets::sockaddrs bindaddr;
122 irc::sockets::sockaddrs connaddr;
124 memcpy(&bindaddr, &user->server_sa, sizeof(bindaddr));
125 memcpy(&connaddr, &user->client_sa, sizeof(connaddr));
127 if (connaddr.family() == AF_INET6)
129 bindaddr.in6.sin6_port = 0;
130 connaddr.in6.sin6_port = htons(113);
134 bindaddr.in4.sin_port = 0;
135 connaddr.in4.sin_port = htons(113);
138 /* Attempt to bind (ident requests must come from the ip the query is referring to */
139 if (SocketEngine::Bind(GetFd(), bindaddr) < 0)
142 throw ModuleException("failed to bind()");
145 SocketEngine::NonBlocking(GetFd());
147 /* Attempt connection (nonblocking) */
148 if (SocketEngine::Connect(this, connaddr) == -1 && errno != EINPROGRESS)
151 throw ModuleException("connect() failed");
154 /* Add fd to socket engine */
155 if (!SocketEngine::AddFd(this, FD_WANT_NO_READ | FD_WANT_POLL_WRITE))
158 throw ModuleException("out of fds");
162 void OnEventHandlerWrite() CXX11_OVERRIDE
164 SocketEngine::ChangeEventMask(this, FD_WANT_POLL_READ | FD_WANT_NO_WRITE);
168 /* Build request in the form 'localport,remoteport\r\n' */
170 if (user->client_sa.family() == AF_INET6)
171 req_size = snprintf(req, sizeof(req), "%d,%d\r\n",
172 ntohs(user->client_sa.in6.sin6_port), ntohs(user->server_sa.in6.sin6_port));
174 req_size = snprintf(req, sizeof(req), "%d,%d\r\n",
175 ntohs(user->client_sa.in4.sin_port), ntohs(user->server_sa.in4.sin_port));
177 /* Send failed if we didnt write the whole ident request --
178 * might as well give up if this happens!
180 if (SocketEngine::Send(this, req, req_size, 0) < req_size)
186 /* Remove ident socket from engine, and close it, but dont detach it
187 * from its parent user class, or attempt to delete its memory.
191 ServerInstance->Logs->Log(MODNAME, LOG_DEBUG, "Close ident socket %d", GetFd());
192 SocketEngine::Close(this);
201 void OnEventHandlerRead() CXX11_OVERRIDE
203 /* We don't really need to buffer for incomplete replies here, since IDENT replies are
204 * extremely short - there is *no* sane reason it'd be in more than one packet
207 int recvresult = SocketEngine::Recv(this, ibuf, sizeof(ibuf)-1, 0);
209 /* Close (but don't delete from memory) our socket
210 * and flag as done since the ident lookup has finished
215 /* Cant possibly be a valid response shorter than 3 chars,
216 * because the shortest possible response would look like: '1,1'
221 ServerInstance->Logs->Log(MODNAME, LOG_DEBUG, "ReadResponse()");
223 /* Truncate at the first null character, but first make sure
224 * there is at least one null char (at the end of the buffer).
226 ibuf[recvresult] = '\0';
227 std::string buf(ibuf);
229 /* <2 colons: invalid
230 * 2 colons: reply is an error
231 * >3 colons: there is a colon in the ident
233 if (std::count(buf.begin(), buf.end(), ':') != 3)
236 std::string::size_type lastcolon = buf.rfind(':');
238 /* Truncate the ident at any characters we don't like, skip leading spaces */
239 for (std::string::const_iterator i = buf.begin()+lastcolon+1; i != buf.end(); ++i)
241 if (result.size() == ServerInstance->Config->Limits.IdentMax)
242 /* Ident is getting too long */
248 /* Add the next char to the result and see if it's still a valid ident,
249 * according to IsIdent(). If it isn't, then erase what we just added and
253 if (!ServerInstance->IsIdent(result))
255 result.erase(result.end()-1);
261 void OnEventHandlerError(int errornum) CXX11_OVERRIDE
267 CullResult cull() CXX11_OVERRIDE
270 return EventHandler::cull();
274 class ModuleIdent : public Module
277 unsigned int timeout;
278 bool prefixunqueried;
279 SimpleExtItem<IdentRequestSocket, stdalgo::culldeleter> socket;
282 static void PrefixIdent(LocalUser* user)
284 // Check that they haven't been prefixed already.
285 if (user->ident[0] == '~')
288 // All invalid usernames are prefixed with a tilde.
289 std::string newident(user->ident);
290 newident.insert(newident.begin(), '~');
292 // If the username is too long then truncate it.
293 if (newident.length() > ServerInstance->Config->Limits.IdentMax)
294 newident.erase(ServerInstance->Config->Limits.IdentMax);
296 // Apply the new username.
297 user->ChangeIdent(newident);
302 : socket("ident_socket", ExtensionItem::EXT_USER, this)
303 , state("ident_state", ExtensionItem::EXT_USER, this)
307 Version GetVersion() CXX11_OVERRIDE
309 return Version("Allows the usernames (idents) of users to be looked up using the RFC 1413 Identification Protocol.", VF_VENDOR);
312 void ReadConfig(ConfigStatus& status) CXX11_OVERRIDE
314 ConfigTag* tag = ServerInstance->Config->ConfValue("ident");
315 timeout = tag->getDuration("timeout", 5, 1, 60);
316 prefixunqueried = tag->getBool("prefixunqueried");
319 void OnSetUserIP(LocalUser* user) CXX11_OVERRIDE
321 IdentRequestSocket* isock = socket.get(user);
324 // If an ident lookup request was in progress then cancel it.
329 // The ident protocol requires that clients are connecting over a protocol with ports.
330 if (user->client_sa.family() != AF_INET && user->client_sa.family() != AF_INET6)
333 // We don't want to look this up once the user has connected.
334 if (user->registered == REG_ALL || user->quitting)
337 ConfigTag* tag = user->MyClass->config;
338 if (!tag->getBool("useident", true))
340 state.set(user, IDENT_SKIPPED);
344 user->WriteNotice("*** Looking up your ident...");
348 isock = new IdentRequestSocket(user);
349 socket.set(user, isock);
351 catch (ModuleException &e)
353 ServerInstance->Logs->Log(MODNAME, LOG_DEBUG, "Ident exception: " + e.GetReason());
357 /* This triggers pretty regularly, we can use it in preference to
358 * creating a Timer object and especially better than creating a
359 * Timer per ident lookup!
361 ModResult OnCheckReady(LocalUser *user) CXX11_OVERRIDE
363 /* Does user have an ident socket attached at all? */
364 IdentRequestSocket* isock = socket.get(user);
367 if (prefixunqueried && state.get(user) == IDENT_SKIPPED)
370 state.set(user, IDENT_PREFIXED);
372 return MOD_RES_PASSTHRU;
375 time_t compare = isock->age + timeout;
377 /* Check for timeout of the socket */
378 if (ServerInstance->Time() >= compare)
381 state.set(user, IDENT_MISSING);
383 user->WriteNotice("*** Ident lookup timed out, using " + user->ident + " instead.");
385 else if (!isock->HasResult())
387 // time still good, no result yet... hold the registration
391 /* wooo, got a result (it will be good, or bad) */
392 else if (isock->result.empty())
394 state.set(user, IDENT_MISSING);
396 user->WriteNotice("*** Could not find your ident, using " + user->ident + " instead.");
400 state.set(user, IDENT_FOUND);
401 user->ChangeIdent(isock->result);
402 user->WriteNotice("*** Found your ident, '" + user->ident + "'");
407 return MOD_RES_PASSTHRU;
410 ModResult OnSetConnectClass(LocalUser* user, ConnectClass* myclass) CXX11_OVERRIDE
412 if (myclass->config->getBool("requireident") && state.get(user) != IDENT_FOUND)
414 ServerInstance->Logs->Log("CONNECTCLASS", LOG_DEBUG, "The %s connect class is not suitable as it requires an identd response",
415 myclass->GetName().c_str());
418 return MOD_RES_PASSTHRU;
421 void OnUserConnect(LocalUser* user) CXX11_OVERRIDE
423 // Clear this as it is no longer necessary.
428 MODULE_INIT(ModuleIdent)