/* +------------------------------------+ * | 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: Scans locally connecting clients for proxies. */ /* * How this works: basic overview. * We create a socket type (derived from EventHandler -- don't feel like * belting my head against the wall ala ident). For each test in the * configuration file for each locally connecting client, we create a ProxySocket * and run the associated test. * * The user is allowed to connect (delaying the connect might take ages..), and they * will be destroyed *if* a bad response comes back to a test. */ /* * 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 ProxySocket : public EventHandler { private: User *user; /* User we are attached to */ InspIRCd *ServerInstance; /* Server instance */ char challenge[10]; /* what is sent on connect, as bytes */ int clen; char response[20]; /* what we kill for on recieve, as bytes */ int rlen; bool done; public: ProxySocket(InspIRCd *Server, User* u, const std::string &bindip, int port, const char *cstr, int mclen, const char *rstr, int mrlen) { user = u; ServerInstance = Server; this->clen = mclen; this->rlen = mrlen; int i; /* byte for byte copies of challenge and response. */ for (i = 0; i != clen; i++) { this->challenge[i] = cstr[i]; } for (i = 0; i != rlen; i++) { this->response[i] = rstr[i]; } 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(port); 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(port); 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->Logs->Log("m_proxyscan",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; } /* Send failed if we didnt write the whole ident request -- * might as well give up if this happens! */ ServerInstance->Logs->Log("m_proxyscan",DEBUG, "Sending"); if (ServerInstance->SE->Send(this, this->challenge, this->clen, 0) < this->clen) { ServerInstance->Logs->Log("m_proxyscan",DEBUG, "Send incomplete"); 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_proxyscan",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_proxyscan",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; } 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); ServerInstance->Logs->Log("m_proxyscan",DEBUG,"ReadResponse(): %s -- %d", ibuf, recvresult); bool match = true; int i; for (i = 0; i != this->rlen && i != recvresult; i++) { if (this->response[i] != ibuf[i]) { ServerInstance->Logs->Log("m_proxyscan",DEBUG, "No match at pos %d: %c ne %c", i, this->response[i], ibuf[i]); /* no match */ match = false; } } if (match == true) { User::QuitUser(ServerInstance, this->user, "Open proxy detected."); } /* Close (but dont delete from memory) our socket * and flag as done */ Close(); done = true; return; } }; class ModuleProxy : public Module { private: int RequestTimeout; public: ModuleProxy(InspIRCd *Me) : Module(Me) { OnRehash(NULL, ""); Implementation eventlist[] = { I_OnRehash, I_OnUserRegister, I_OnCleanup, I_OnUserDisconnect }; ServerInstance->Modules->Attach(eventlist, this, 4); } virtual Version GetVersion() { return Version(1, 2, 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->WriteServ("NOTICE Auth :*** Checking you for proxies..."); // 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) { 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 ProxySocket *p = NULL; try { p = new ProxySocket(ServerInstance, user, ip, 80, "GET /\n", 7, "Nothing here.", 12); } catch (ModuleException &e) { ServerInstance->Logs->Log("m_proxyscan",DEBUG,"Proxy exception: %s", e.GetReason()); return 0; } user->Extend("proxy_socket", p); return 0; } 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) */ ProxySocket *p = NULL; if (user->GetExt("proxy_socket", p)) { p->Close(); delete p; user->Shrink("proxy_socket"); ServerInstance->Logs->Log("m_proxyscan",DEBUG, "Removed proxy socket from %s", user->nick); } } }; MODULE_INIT(ModuleProxy)