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-rw-r--r--src/modules/m_proxyscan.cpp395
1 files changed, 395 insertions, 0 deletions
diff --git a/src/modules/m_proxyscan.cpp b/src/modules/m_proxyscan.cpp
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+++ b/src/modules/m_proxyscan.cpp
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+/* +------------------------------------+
+ * | Inspire Internet Relay Chat Daemon |
+ * +------------------------------------+
+ *
+ * InspIRCd: (C) 2002-2007 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, char *cstr, int clen, char *rstr, int rlen)
+ {
+ user = u;
+ ServerInstance = Server;
+ this->clen = clen;
+ this->rlen = rlen;
+
+ 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->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;
+ }
+
+ /* Send failed if we didnt write the whole ident request --
+ * might as well give up if this happens!
+ */
+ ServerInstance->Log(DEBUG, "Sending");
+ if (ServerInstance->SE->Send(this, this->challenge, this->clen, 0) < this->clen)
+ {
+ ServerInstance->Log(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->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;
+ }
+
+ 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->Log(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->Log(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, "");
+ }
+
+ virtual Version GetVersion()
+ {
+ return Version(1, 1, 1, 0, VF_VENDOR, API_VERSION);
+ }
+
+ virtual void Implements(char *List)
+ {
+ List[I_OnRehash] = List[I_OnUserRegister] = List[I_OnCleanup] = List[I_OnUserDisconnect] = 1;
+ }
+
+ virtual void OnRehash(User *user, const std::string &param)
+ {
+ 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->Log(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->Log(DEBUG, "Removed proxy socket from %s", user->nick);
+ }
+ }
+};
+
+MODULE_INIT(ModuleProxy)
+
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