+/* +------------------------------------+
+ * | Inspire Internet Relay Chat Daemon |
+ * +------------------------------------+
+ *
+ * InspIRCd: (C) 2002-2008 InspIRCd Development Team
+ * See: http://www.inspircd.org/wiki/index.php/Credits
+ *
+ * This program is free but copyrighted software; see
+ * the file COPYING for details.
+ *
+ * ---------------------------------------------------
+ */
+
+#include "inspircd.h"
+#include "users.h"
+#include "channels.h"
+#include "modules.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");
+
+ /* We allocate two of these because sizeof(sockaddr_in6) > sizeof(sockaddr_in) */
+ sockaddr* s = new sockaddr[2];
+ sockaddr* addr = new sockaddr[2];
+
+#ifdef IPV6
+ /* Horrid icky nasty ugly berkely socket crap. */
+ if (v6)
+ {
+ in6_addr addy;
+ in6_addr n;
+ if (inet_pton(AF_INET6, user->GetIPString(), &addy) > 0)
+ {
+ ((sockaddr_in6*)addr)->sin6_family = AF_INET6;
+ memcpy(&((sockaddr_in6*)addr)->sin6_addr, &addy, sizeof(addy));
+ ((sockaddr_in6*)addr)->sin6_port = htons(113);
+ size = sizeof(sockaddr_in6);
+ inet_pton(AF_INET6, bindip.c_str(), &n);
+ memcpy(&((sockaddr_in6*)s)->sin6_addr, &n, sizeof(sockaddr_in6));
+ ((sockaddr_in6*)s)->sin6_port = 0;
+ ((sockaddr_in6*)s)->sin6_family = AF_INET6;
+ }
+ }
+ else
+#endif
+ {
+ in_addr addy;
+ in_addr n;
+ if (inet_aton(user->GetIPString(), &addy) > 0)
+ {
+ ((sockaddr_in*)addr)->sin_family = AF_INET;
+ ((sockaddr_in*)addr)->sin_addr = addy;
+ ((sockaddr_in*)addr)->sin_port = htons(113);
+ size = sizeof(sockaddr_in);
+ inet_aton(bindip.c_str(), &n);
+ ((sockaddr_in*)s)->sin_addr = n;
+ ((sockaddr_in*)s)->sin_port = 0;
+ ((sockaddr_in*)s)->sin_family = AF_INET;
+ }
+ }
+
+ /* Attempt to bind (ident requests must come from the ip the query is referring to */
+ if (ServerInstance->SE->Bind(GetFd(), s, size) < 0)
+ {
+ this->Close();
+ delete[] s;
+ delete[] addr;
+ throw ModuleException("failed to bind()");
+ }
+
+ delete[] s;
+ ServerInstance->SE->NonBlocking(GetFd());
+
+ /* Attempt connection (nonblocking) */
+ if (ServerInstance->SE->Connect(this, (sockaddr*)addr, size) == -1 && errno != EINPROGRESS)
+ {
+ this->Close();
+ delete[] addr;
+ throw ModuleException("connect() failed");
+ }
+
+ delete[] addr;
+
+ /* 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->Log(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). */
+ #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))
+ {
+ done = true;
+ return;
+ }
+
+ char req[32];
+
+ /* Build request in the form 'localport,remoteport\r\n' */
+ #ifndef IPV6
+ int req_size = snprintf(req, sizeof(req), "%d,%d\r\n", ntohs(raddr.sin_port), ntohs(laddr.sin_port));
+ #else
+ int req_size = snprintf(req, sizeof(req), "%d,%d\r\n", ntohs(raddr.sin6_port), ntohs(laddr.sin6_port));
+ #endif
+
+ /* 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->Log(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->Log(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->Log(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;
+
+ 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++)
+ {
+ if (*j == ' ')
+ continue;
+
+ /* Rules taken from InspIRCd::IsIdent */
+ if (((*j >= 'A') && (*j <= '}')) || ((*j >= '0') && (*j <= '9')) || (*j == '-') || (*j == '.'))
+ {
+ ident[k++] = *j;
+ continue;
+ }
+
+ break;
+ }
+
+ ident[k] = '\0';
+
+ /* Re-check with IsIdent, in case that changes and this doesn't (paranoia!) */
+ if (*ident && ServerInstance->IsIdent(ident))
+ {
+ 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;
+ public:
+ ModuleIdent(InspIRCd *Me)
+ : Module(Me)
+ {
+ OnRehash(NULL, "");
+ Implementation eventlist[] = { I_OnRehash, I_OnUserRegister, I_OnCheckReady, I_OnCleanup, I_OnUserDisconnect };
+ ServerInstance->Modules->Attach(eventlist, this, 5);
+ }
+
+ virtual Version GetVersion()
+ {
+ return Version(1, 1, 1, 0, VF_VENDOR, API_VERSION);
+ }
+
+
+ virtual void OnRehash(User *user, const std::string ¶m)
+ {
+ ConfigReader MyConf(ServerInstance);
+
+ RequestTimeout = MyConf.ReadInteger("ident", "timeout", 0, true);
+ if (!RequestTimeout)
+ RequestTimeout = 5;
+ }
+
+ virtual int OnUserRegister(User *user)
+ {
+ /* 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. */
+ 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)
+ {
+ user->WriteServ("NOTICE Auth :*** Could not find your ident, using %s instead.", user->ident);
+ return 0;
+ }
+
+ #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 = NULL;
+ try
+ {
+ isock = new IdentRequestSocket(ServerInstance, user, ip);
+ }
+ catch (ModuleException &e)
+ {
+ ServerInstance->Log(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)
+ {
+ ServerInstance->Log(DEBUG,"OnCheckReady %s", user->nick);
+
+ /* Does user have an ident socket attached at all? */
+ IdentRequestSocket *isock = NULL;
+ if (!user->GetExt("ident_socket", isock))
+ {
+ ServerInstance->Log(DEBUG, "No ident socket :(");
+ return true;
+ }
+
+ ServerInstance->Log(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->Log(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->Log(DEBUG, "No result yet");
+ return false;
+ }
+
+ ServerInstance->Log(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 */
+ strlcpy(user->ident, isock->GetResult(), IDENTMAX+1);
+
+ /* 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");
+ ServerInstance->Log(DEBUG, "Removed ident socket from %s", user->nick);
+ }
+ }
+};
+
+MODULE_INIT(ModuleIdent)
+