/*
* InspIRCd -- Internet Relay Chat Daemon
*
* Copyright (C) 2007, 2009 John Brooks <john.brooks@dereferenced.net>
* Copyright (C) 2009 Daniel De Graaf <danieldg@inspircd.org>
* Copyright (C) 2006-2008 Robin Burchell <robin+git@viroteck.net>
* Copyright (C) 2005-2008 Craig Edwards <craigedwards@brainbox.cc>
* Copyright (C) 2008 Thomas Stagner <aquanight@inspircd.org>
* Copyright (C) 2007 Dennis Friis <peavey@inspircd.org>
*
* 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 <http://www.gnu.org/licenses/>.
*/
#include "inspircd.h"
/* $ModDesc: Provides support for RFC1413 ident lookups */
/* --------------------------------------------------------------
* 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, theres 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 EventHandler
{
private:
User *user; /* User we are attached to */
InspIRCd* ServerInstance; /* Server instance */
bool done; /* True if lookup is finished */
std::string result; /* Holds the ident string if done */
public:
IdentRequestSocket(InspIRCd *Server, User* u, const std::string &bindip) : user(u), ServerInstance(Server), result(u->ident)
{
socklen_t size = 0;
#ifdef IPV6
/* Does this look like a v6 ip address? */
bool v6 = false;
if ((bindip.empty()) || bindip.find(':') != std::string::npos)
v6 = true;
if (v6)
SetFd(socket(AF_INET6, SOCK_STREAM, 0));
else
#endif
SetFd(socket(AF_INET, SOCK_STREAM, 0));
if (GetFd() == -1)
throw ModuleException("Could not create socket");
done = false;
/* We allocate two of these because sizeof(sockaddr_in6) > sizeof(sockaddr_in) */
irc::sockets::sockaddrs s;
irc::sockets::sockaddrs addr;
#ifdef IPV6
/* Horrid icky nasty ugly berkely socket crap. */
if (v6)
{
if (inet_pton(AF_INET6, user->GetIPString(), &addr.in6.sin6_addr) > 0)
{
addr.in6.sin6_family = AF_INET6;
addr.in6.sin6_port = htons(113);
size = sizeof(sockaddr_in6);
inet_pton(AF_INET6, bindip.c_str(), &s.in6.sin6_addr);
s.in6.sin6_family = AF_INET6;
s.in6.sin6_port = 0;
}
}
else
#endif
{
if (inet_aton(user->GetIPString(), &addr.in4.sin_addr) > 0)
{
addr.in4.sin_family = AF_INET;
addr.in4.sin_port = htons(113);
size = sizeof(sockaddr_in);
inet_aton(bindip.c_str(), &s.in4.sin_addr);
s.in4.sin_family = AF_INET;
s.in4.sin_port = 0;
}
}
/* Attempt to bind (ident requests must come from the ip the query is referring to */
if (ServerInstance->SE->Bind(GetFd(), &s.sa, size) < 0)
{
this->Close();
throw ModuleException("failed to bind()");
}
ServerInstance->SE->NonBlocking(GetFd());
/* Attempt connection (nonblocking) */
if (ServerInstance->SE->Connect(this, &addr.sa, size) == -1 && errno != EINPROGRESS)
{
this->Close();
throw ModuleException("connect() failed");
}
/* Add fd to socket engine */
if (!ServerInstance->SE->AddFd(this))
{
this->Close();
throw ModuleException("out of fds");
}
/* Important: We set WantWrite immediately after connect()
* because a successful connection will trigger a writability event
*/
ServerInstance->SE->WantWrite(this);
}
virtual void OnConnected()
{
ServerInstance->Logs->Log("m_ident",DEBUG,"OnConnected()");
/* 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). */
irc::sockets::sockaddrs laddr, raddr;
socklen_t laddrsz = sizeof(laddr);
socklen_t raddrsz = sizeof(raddr);
if ((getsockname(user->GetFd(), &laddr.sa, &laddrsz) != 0) || (getpeername(user->GetFd(), &raddr.sa, &raddrsz) != 0))
{
done = true;
return;
}
char req[32];
/* Build request in the form 'localport,remoteport\r\n' */
int req_size;
#ifdef IPV6
if (raddr.sa.sa_family == AF_INET6)
req_size = snprintf(req, sizeof(req), "%d,%d\r\n", ntohs(raddr.in6.sin6_port), ntohs(laddr.in6.sin6_port));
else
#endif
req_size = snprintf(req, sizeof(req), "%d,%d\r\n", ntohs(raddr.in4.sin_port), ntohs(laddr.in4.sin_port));
/* Send failed if we didnt write the whole ident request --
* might as well give up if this happens!
*/
if (ServerInstance->SE->Send(this, req, req_size, 0) < req_size)
done = true;
}
virtual void HandleEvent(EventType et, int errornum = 0)
{
switch (et)
{
case EVENT_READ:
/* fd readable event, received ident response */
ReadResponse();
break;
case EVENT_WRITE:
/* fd writeable event, successfully connected! */
OnConnected();
break;
case EVENT_ERROR:
/* fd error event, ohshi- */
ServerInstance->Logs->Log("m_ident",DEBUG,"EVENT_ERROR");
/* We *must* Close() here immediately or we get a
* huge storm of EVENT_ERROR events!
*/
Close();
done = true;
break;
}
}
void Close()
{
/* Remove ident socket from engine, and close it, but dont detatch it
* from its parent user class, or attempt to delete its memory.
*/
if (GetFd() > -1)
{
ServerInstance->Logs->Log("m_ident",DEBUG,"Close ident socket %d", GetFd());
ServerInstance->SE->DelFd(this);
ServerInstance->SE->Close(GetFd());
ServerInstance->SE->Shutdown(GetFd(), SHUT_WR);
this->SetFd(-1);
}
}
bool HasResult()
{
return done;
}
/* Note: if the lookup succeeded, will contain 'ident', otherwise
* will contain '~ident'. Use *GetResult() to determine lookup success.
*/
const char* GetResult()
{
return result.c_str();
}
void ReadResponse()
{
/* 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[MAXBUF];
int recvresult = ServerInstance->SE->Recv(this, ibuf, MAXBUF-1, 0);
/* Cant possibly be a valid response shorter than 3 chars,
* because the shortest possible response would look like: '1,1'
*/
if (recvresult < 3)
{
Close();
done = true;
return;
}
ServerInstance->Logs->Log("m_ident",DEBUG,"ReadResponse()");
irc::sepstream sep(ibuf, ':');
std::string token;
for (int i = 0; sep.GetToken(token); i++)
{
/* We only really care about the 4th portion */
if (i < 3)
continue;
std::string ident;
/* Truncate the ident at any characters we don't like, skip leading spaces */
size_t k = 0;
for (const char *j = token.c_str(); *j && (k < ServerInstance->Config->Limits.IdentMax + 1); j++)
{
if (*j == ' ')
continue;
/* Rules taken from InspIRCd::IsIdent */
if (((*j >= 'A') && (*j <= '}')) || ((*j >= '0') && (*j <= '9')) || (*j == '-') || (*j == '.'))
{
ident += *j;
continue;
}
break;
}
/* Re-check with IsIdent, in case that changes and this doesn't (paranoia!) */
if (!ident.empty() && ServerInstance->IsIdent(ident.c_str()))
{
result = ident;
}
break;
}
/* Close (but dont delete from memory) our socket
* and flag as done
*/
Close();
done = true;
return;
}
};
class ModuleIdent : public Module
{
private:
int RequestTimeout;
ConfigReader *Conf;
public:
ModuleIdent(InspIRCd *Me) : Module(Me)
{
Conf = new ConfigReader(ServerInstance);
OnRehash(NULL);
Implementation eventlist[] = { I_OnRehash, I_OnUserRegister, I_OnCheckReady, I_OnCleanup, I_OnUserDisconnect };
ServerInstance->Modules->Attach(eventlist, this, 5);
}
~ModuleIdent()
{
delete Conf;
}
virtual Version GetVersion()
{
return Version("$Id$", VF_VENDOR, API_VERSION);
}
virtual void OnRehash(User *user)
{
delete Conf;
Conf = new ConfigReader(ServerInstance);
RequestTimeout = Conf->ReadInteger("ident", "timeout", 0, true);
if (!RequestTimeout)
RequestTimeout = 5;
}
virtual int OnUserRegister(User *user)
{
if (user->GetExt("ident_socket"))
return 0;
for (int j = 0; j < Conf->Enumerate("connect"); j++)
{
std::string hostn = Conf->ReadValue("connect","allow",j);
/* XXX: Fixme: does not respect port, limit, etc */
if ((InspIRCd::MatchCIDR(user->GetIPString(),hostn, ascii_case_insensitive_map)) || (InspIRCd::Match(user->host,hostn, ascii_case_insensitive_map)))
{
bool useident = Conf->ReadFlag("connect", "useident", "yes", j);
if (!useident)
return 0;
}
}
/* User::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. */
if (user->ident.length() > ServerInstance->Config->Limits.IdentMax + 1)
user->ident.assign(user->ident, 0, ServerInstance->Config->Limits.IdentMax);
user->ident.insert(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
irc::sockets::sockaddrs laddr;
socklen_t laddrsz = sizeof(laddr);
if (getsockname(user->GetFd(), &laddr.sa, &laddrsz) != 0)
{
user->WriteServ("NOTICE Auth :*** Could not find your ident, using %s instead.", user->ident.c_str());
return 0;
}
char ip[INET6_ADDRSTRLEN + 1];
#ifdef IPV6
if (laddr.sa.sa_family == AF_INET6)
inet_ntop(laddr.in6.sin6_family, &laddr.in6.sin6_addr, ip, INET6_ADDRSTRLEN);
else
#endif
inet_ntop(laddr.in4.sin_family, &laddr.in4.sin_addr, ip, INET6_ADDRSTRLEN);
IdentRequestSocket *isock = NULL;
try
{
isock = new IdentRequestSocket(ServerInstance, user, ip);
}
catch (ModuleException &e)
{
ServerInstance->Logs->Log("m_ident",DEBUG,"Ident exception: %s", e.GetReason());
return 0;
}
user->Extend("ident_socket", isock);
return 0;
}
/* 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!
*/
virtual bool OnCheckReady(User *user)
{
/* Does user have an ident socket attached at all? */
IdentRequestSocket *isock = NULL;
if (!user->GetExt("ident_socket", isock))
{
ServerInstance->Logs->Log("m_ident",DEBUG, "No ident socket :(");
return true;
}
ServerInstance->Logs->Log("m_ident",DEBUG, "Has ident_socket");
time_t compare = isock->age;
compare += RequestTimeout;
/* Check for timeout of the socket */
if (ServerInstance->Time() >= compare)
{
/* Ident timeout */
user->WriteServ("NOTICE Auth :*** Ident request timed out.");
ServerInstance->Logs->Log("m_ident",DEBUG, "Timeout");
/* The user isnt actually disconnecting,
* we call this to clean up the user
*/
OnUserDisconnect(user);
return true;
}
/* Got a result yet? */
if (!isock->HasResult())
{
ServerInstance->Logs->Log("m_ident",DEBUG, "No result yet");
return false;
}
ServerInstance->Logs->Log("m_ident",DEBUG, "Yay, result!");
/* wooo, got a result (it will be good, or bad) */
if (*(isock->GetResult()) != '~')
user->WriteServ("NOTICE Auth :*** Found your ident, '%s'", isock->GetResult());
else
user->WriteServ("NOTICE Auth :*** Could not find your ident, using %s instead.", isock->GetResult());
/* Copy the ident string to the user */
user->ChangeIdent(isock->GetResult());
/* The user isnt actually disconnecting, we call this to clean up the user */
OnUserDisconnect(user);
return true;
}
virtual void OnCleanup(int target_type, void *item)
{
/* Module unloading, tidy up users */
if (target_type == TYPE_USER)
OnUserDisconnect((User*)item);
}
virtual void OnUserDisconnect(User *user)
{
/* User disconnect (generic socket detatch event) */
IdentRequestSocket *isock = NULL;
if (user->GetExt("ident_socket", isock))
{
isock->Close();
delete isock;
user->Shrink("ident_socket");
}
}
};
MODULE_INIT(ModuleIdent)
