/* -*-mode: C; fill-column: 78; c-basic-offset: 4; -*- */ /* * Copyright 2005 - 2009 by Eric House (xwords@eehouse.org). All rights reserved. * * This program 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; either version 2 * of the License, or (at your option) any later version. * * 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, write to the Free Software * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ ////////////////////////////////////////////////////////////////////////////// // // This program is a *very rough* cut at a message forwarding server that's // meant to sit somewhere that cellphones can reach and forward packets across // connections so that they can communicate. It exists to work around the // fact that many cellular carriers prevent direct incoming connections from // reaching devices on their networks. It's meant for Crosswords, but might // be useful for other things. It also needs a lot of work, and I hacked it // up before making an exhaustive search for other alternatives. // ////////////////////////////////////////////////////////////////////////////// #include #include #include /* gethostbyname */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #if defined(__FreeBSD__) # if (OSVERSION > 500000) # include "getopt.h" # else # include "unistd.h" # endif #else # include #endif #include #include "xwrelay.h" #include "crefmgr.h" #include "ctrl.h" #include "http.h" #include "mlock.h" #include "tpool.h" #include "configs.h" #include "timermgr.h" #include "permid.h" #include "lstnrmgr.h" #define LOG_FILE_PATH "./xwrelay.log" void logf( XW_LogLevel level, const char* format, ... ) { RelayConfigs* rc = RelayConfigs::GetConfigs(); int configLevel = level; if ( NULL != rc ) { if ( ! rc->GetValueFor( "LOGLEVEL", &configLevel ) ) { configLevel = level - 1; /* drop it */ } } if ( level <= configLevel ) { #ifdef USE_SYSLOG char buf[256]; va_list ap; va_start( ap, format ); vsnprintf( buf, sizeof(buf), format, ap ); syslog( LOG_LOCAL0 | LOG_INFO, buf ); va_end(ap); #else static FILE* where = stderr; struct tm* timp; struct timeval tv; struct timezone tz; if ( !where ) { where = fopen( LOG_FILE_PATH, "a" ); } gettimeofday( &tv, &tz ); timp = localtime( &tv.tv_sec ); pthread_t me = pthread_self(); fprintf( where, "<%p>%d:%d:%d: ", (void*)me, timp->tm_hour, timp->tm_min, timp->tm_sec ); va_list ap; va_start( ap, format ); vfprintf( where, format, ap ); va_end(ap); fprintf( where, "\n" ); #endif } } /* logf */ static const char* cmdToStr( XWRELAY_Cmd cmd ) { # define CASESTR(s) case s: return #s switch( cmd ) { CASESTR(XWRELAY_NONE); CASESTR(XWRELAY_GAME_CONNECT); CASESTR(XWRELAY_GAME_RECONNECT); CASESTR(XWRELAY_GAME_DISCONNECT); CASESTR(XWRELAY_CONNECT_RESP); CASESTR(XWRELAY_RECONNECT_RESP); CASESTR(XWRELAY_ALLHERE); CASESTR(XWRELAY_DISCONNECT_YOU); CASESTR(XWRELAY_DISCONNECT_OTHER); CASESTR(XWRELAY_CONNECTDENIED); CASESTR(XWRELAY_HEARTBEAT); CASESTR(XWRELAY_MSG_FROMRELAY); CASESTR(XWRELAY_MSG_TORELAY); default: logf( XW_LOGERROR, "%s: unknown command %d", __func__, cmd ); return ""; } } static bool getNetShort( unsigned char** bufpp, unsigned char* end, unsigned short* out ) { bool ok = *bufpp + 2 <= end; if ( ok ) { unsigned short tmp; memcpy( &tmp, *bufpp, 2 ); *bufpp += 2; *out = ntohs( tmp ); } return ok; } /* getNetShort */ static bool getNetByte( unsigned char** bufpp, unsigned char* end, unsigned char* out ) { bool ok = *bufpp < end; if ( ok ) { *out = **bufpp; ++*bufpp; } return ok; } /* getNetByte */ #ifdef RELAY_HEARTBEAT static bool processHeartbeat( unsigned char* buf, int bufLen, int socket ) { unsigned char* end = buf + bufLen; CookieID cookieID; HostID hostID; bool success = false; if ( getNetShort( &buf, end, &cookieID ) && getNetByte( &buf, end, &hostID ) ) { logf( XW_LOGINFO, "processHeartbeat: cookieID 0x%lx, hostID 0x%x", cookieID, hostID ); SafeCref scr( cookieID ); success = scr.HandleHeartbeat( hostID, socket ); if ( !success ) { killSocket( socket, "no cref for socket" ); } } return success; } /* processHeartbeat */ #endif static bool readStr( unsigned char** bufp, const unsigned char* end, char* outBuf, int bufLen ) { unsigned char clen = **bufp; ++*bufp; if ( ((*bufp + clen) <= end) && (clen < bufLen) ) { memcpy( outBuf, *bufp, clen ); outBuf[clen] = '\0'; *bufp += clen; return true; } return false; } /* readStr */ static XWREASON flagsOK( unsigned char flags ) { return flags == XWRELAY_PROTO_VERSION ? XWRELAY_ERROR_NONE : XWRELAY_ERROR_OLDFLAGS; } /* flagsOK */ static void denyConnection( int socket, XWREASON err ) { unsigned char buf[2]; buf[0] = XWRELAY_CONNECTDENIED; buf[1] = err; send_with_length_unsafe( socket, buf, sizeof(buf) ); } /* No mutex here. Caller better be ensuring no other thread can access this * socket. */ bool send_with_length_unsafe( int socket, unsigned char* buf, int bufLen ) { bool ok = false; unsigned short len = htons( bufLen ); ssize_t nSent = send( socket, &len, 2, 0 ); if ( nSent == 2 ) { nSent = send( socket, buf, bufLen, 0 ); if ( nSent == bufLen ) { logf( XW_LOGINFO, "sent %d bytes on socket %d", nSent, socket ); ok = true; } } return ok; } /* send_with_length_unsafe */ /* A CONNECT message from a device gives us the hostID and socket we'll * associate with one participant in a relayed session. We'll store this * information with the cookie where other participants can find it when they * arrive. * * What to do if we already have a game going? In that case the connection ID * passed in will be non-zero. If the device can be associated with an * ongoing game, with its new socket, associate it and forward any messages * outstanding. Otherwise close down the socket. And maybe the others in the * game? */ static bool processConnect( unsigned char* bufp, int bufLen, int socket ) { char cookie[MAX_COOKIE_LEN+1]; unsigned char* end = bufp + bufLen; bool success = false; logf( XW_LOGINFO, "%s()", __func__ ); cookie[0] = '\0'; unsigned char flags = *bufp++; XWREASON err = flagsOK( flags ); if ( err != XWRELAY_ERROR_NONE ) { denyConnection( socket, err ); } else { HostID srcID; unsigned char nPlayersH; unsigned char nPlayersT; if ( readStr( &bufp, end, cookie, sizeof(cookie) ) && getNetByte( &bufp, end, &srcID ) && getNetByte( &bufp, end, &nPlayersH ) && getNetByte( &bufp, end, &nPlayersT ) ) { SafeCref scr( cookie, true, srcID, socket, nPlayersH, nPlayersT ); success = scr.Connect( socket, srcID, nPlayersH, nPlayersT ); } if ( !success ) { denyConnection( socket, XWRELAY_ERROR_BADPROTO ); } } return success; } /* processConnect */ static bool processReconnect( unsigned char* bufp, int bufLen, int socket ) { unsigned char* end = bufp + bufLen; bool success = false; logf( XW_LOGINFO, "processReconnect" ); unsigned char flags = *bufp++; XWREASON err = flagsOK( flags ); if ( err != XWRELAY_ERROR_NONE ) { denyConnection( socket, err ); } else { char connName[MAX_CONNNAME_LEN+1]; HostID srcID; unsigned char nPlayersH; unsigned char nPlayersT; connName[0] = '\0'; if ( getNetByte( &bufp, end, &srcID ) && getNetByte( &bufp, end, &nPlayersH ) && getNetByte( &bufp, end, &nPlayersT ) && readStr( &bufp, end, connName, sizeof(connName) ) ) { SafeCref scr( connName, 0, srcID, socket, nPlayersH, nPlayersT ); success = scr.Reconnect( socket, srcID, nPlayersH, nPlayersT ); } if ( !success ) { denyConnection( socket, XWRELAY_ERROR_BADPROTO ); } } return success; } /* processReconnect */ static bool processDisconnect( unsigned char* bufp, int bufLen, int socket ) { unsigned char* end = bufp + bufLen; CookieID cookieID; HostID hostID; bool success = false; if ( getNetShort( &bufp, end, &cookieID ) && getNetByte( &bufp, end, &hostID ) ) { SafeCref scr( cookieID ); scr.Disconnect( socket, hostID ); success = true; } else { logf( XW_LOGERROR, "dropping XWRELAY_GAME_DISCONNECT; wrong length" ); } return success; } /* processDisconnect */ void killSocket( int socket, const char* why ) { logf( XW_LOGERROR, "killSocket(%d): %s", socket, why ); CRefMgr::Get()->RemoveSocketRefs( socket ); /* Might want to kill the thread it belongs to if we're not in it, e.g. when unable to write to another socket. */ logf( XW_LOGINFO, "killSocket done" ); XWThreadPool::GetTPool()->CloseSocket( socket ); } time_t now( void ) { static time_t startTime = time(NULL); return time(NULL) - startTime; } /* forward the message. Need only change the command after looking up the * socket and it's ready to go. */ static bool forwardMessage( unsigned char* buf, int buflen, int srcSocket ) { bool success = false; unsigned char* bufp = buf + 1; /* skip cmd */ unsigned char* end = buf + buflen; CookieID cookieID; HostID src; HostID dest; if ( getNetShort( &bufp, end, &cookieID ) && getNetByte( &bufp, end, &src ) && getNetByte( &bufp, end, &dest ) ) { logf( XW_LOGINFO, "cookieID = %d", cookieID ); SafeCref scr( cookieID ); success = scr.Forward( src, dest, buf, buflen ); } return success; } /* forwardMessage */ static bool processMessage( unsigned char* buf, int bufLen, int socket ) { bool success = false; /* default is failure */ XWRELAY_Cmd cmd = *buf; logf( XW_LOGINFO, "%s got %s", __func__, cmdToStr(cmd) ); switch( cmd ) { case XWRELAY_GAME_CONNECT: success = processConnect( buf+1, bufLen-1, socket ); break; case XWRELAY_GAME_RECONNECT: success = processReconnect( buf+1, bufLen-1, socket ); break; case XWRELAY_GAME_DISCONNECT: success = processDisconnect( buf+1, bufLen-1, socket ); break; case XWRELAY_HEARTBEAT: success = processHeartbeat( buf + 1, bufLen - 1, socket ); break; case XWRELAY_MSG_TORELAY: success = forwardMessage( buf, bufLen, socket ); break; default: logf( XW_LOGERROR, "%s bad: %d", __func__, cmd ); break; /* just drop it */ } if ( !success ) { killSocket( socket, "couldn't forward message" ); } return success; /* caller defines non-0 as failure */ } /* processMessage */ int make_socket( unsigned long addr, unsigned short port ) { int sock = socket( AF_INET, SOCK_STREAM, 0 ); assert( sock ); /* We may be relaunching after crashing with sockets open. SO_REUSEADDR allows them to be immediately rebound. */ int t = true; if ( 0 != setsockopt( sock, SOL_SOCKET, SO_REUSEADDR, &t, sizeof(t) ) ) { logf( XW_LOGERROR, "setsockopt failed. errno = %s (%d)\n", strerror(errno), errno ); return -1; } struct sockaddr_in sockAddr; sockAddr.sin_family = AF_INET; sockAddr.sin_addr.s_addr = htonl(addr); sockAddr.sin_port = htons(port); int result = bind( sock, (struct sockaddr*)&sockAddr, sizeof(sockAddr) ); if ( result != 0 ) { logf( XW_LOGERROR, "exiting: unable to bind port %d: %d, " "errno = %s (%d)\n", port, result, strerror(errno), errno ); return -1; } logf( XW_LOGINFO, "bound socket %d on port %d", sock, port ); result = listen( sock, 5 ); if ( result != 0 ) { logf( XW_LOGERROR, "exiting: unable to listen: %d, " "errno = %s (%d)\n", result, strerror(errno), errno ); return -1; } return sock; } /* make_socket */ static void usage( char* arg0 ) { fprintf( stderr, "usage: %s \\\n", arg0 ); fprintf( stderr, "\t-? (print this help)\\\n" "\t-c (localhost port for control console)\\\n" "\t-w (localhost port for web interface)\\\n" "\t-D (don't become daemon)\\\n" "\t-F (don't fork and wait to respawn child)\\\n" "\t-f (config file)\\\n" "\t-h (print this help)\\\n" "\t-i (file where next global id stored)\\\n" "\t-n (used in permID generation)\\\n" "\t-p (port to listen on)\\\n" "\t-t (how many worker threads to use)\\\n" ); fprintf( stderr, "svn rev. %s\n", SVN_REV ); } /* sockets that need to be closable from interrupt handler */ ListenerMgr g_listeners; int g_control; #ifdef DO_HTTP static int g_http; #endif void shutdown() { XWThreadPool* tPool = XWThreadPool::GetTPool(); if ( tPool != NULL ) { tPool->Stop(); } CRefMgr* cmgr = CRefMgr::Get(); if ( cmgr != NULL ) { cmgr->CloseAll(); delete cmgr; } delete tPool; stop_ctrl_threads(); g_listeners.RemoveAll(); close( g_control ); #ifdef DO_HTTP close( g_http ); #endif exit( 0 ); logf( XW_LOGINFO, "exit done" ); } static void SIGINT_handler( int sig ) { logf( XW_LOGERROR, "%s", __func__ ); shutdown(); } #ifdef SPAWN_SELF static void printWhy( int status ) { if ( WIFEXITED(status) ) { logf( XW_LOGINFO, "why: exited" ); } else if ( WIFSIGNALED(status) ) { logf( XW_LOGINFO, "why: signaled" ); } else if ( WCOREDUMP(status) ) { logf( XW_LOGINFO, "why: core" ); } else if ( WIFSTOPPED(status) ) { logf( XW_LOGINFO, "why: traced" ); } } /* printWhy */ #endif static void parentDied( int sig ) { logf( XW_LOGINFO, "%s", __func__ ); exit(0); } int main( int argc, char** argv ) { int port = 0; int ctrlport = 0; #ifdef DO_HTTP int httpport = 0; #endif int nWorkerThreads = 0; char* conffile = NULL; const char* serverName = NULL; const char* idFileName = NULL; bool doDaemon = true; bool doFork = true; (void)now(); /* force capture of start time */ /* Verify sizes here... */ assert( sizeof(CookieID) == 2 ); /* Read options. Options trump config file values when they conflict, but the name of the config file is an option so we have to get that first. */ for ( ; ; ) { int opt = getopt(argc, argv, "h?c:p:n:i:f:t:" #ifdef DO_HTTP "w:" #endif "DF" ); if ( opt == -1 ) { break; } switch( opt ) { case '?': case 'h': usage( argv[0] ); exit( 0 ); case 'c': ctrlport = atoi( optarg ); break; #ifdef DO_HTTP case 'w': httpport = atoi( optarg ); break; #endif case 'D': doDaemon = false; break; case 'F': doFork = false; break; case 'f': conffile = optarg; break; case 'i': idFileName = optarg; break; case 'n': serverName = optarg; break; case 'p': port = atoi( optarg ); break; case 't': nWorkerThreads = atoi( optarg ); break; default: usage( argv[0] ); exit( 1 ); } } /* Did we consume all the options passed in? */ if ( optind != argc ) { usage( argv[0] ); exit( 1 ); } RelayConfigs::InitConfigs( conffile ); RelayConfigs* cfg = RelayConfigs::GetConfigs(); if ( ctrlport == 0 ) { (void)cfg->GetValueFor( "CTLPORT", &ctrlport ); } #ifdef DO_HTTP if ( httpport == 0 ) { (void)cfg->GetValueFor( "WWW_PORT", &httpport ); } #endif if ( nWorkerThreads == 0 ) { (void)cfg->GetValueFor( "NTHREADS", &nWorkerThreads ); } char serverNameBuf[128]; if ( serverName == NULL ) { if ( cfg->GetValueFor( "SERVERNAME", serverNameBuf, sizeof(serverNameBuf) ) ) { serverName = serverNameBuf; } } char idFileNameBuf[128]; if ( idFileName == NULL ) { if ( cfg->GetValueFor( "IDFILE", idFileNameBuf, sizeof(idFileName) ) ) { idFileName = idFileNameBuf; } } PermID::SetServerName( serverName ); PermID::SetIDFileName( idFileName ); /* add signal handling here */ /* The daemon() function is for programs wishing to detach themselves from the controlling terminal and run in the background as system daemons. Unless the argument nochdir is non-zero, daemon() changes the current working directory to the root ("/"). Unless the argument noclose is non-zero, daemon() will redirect standard input, standard output and standard error to /dev/null. (This function forks, and if the fork() succeeds, the parent does _exit(0), so that further errors are seen by the child only.) On success zero will be returned. If an error occurs, daemon() returns -1 and sets the global variable errno to any of the errors specified for the library functions fork(2) and setsid(2). */ if ( doDaemon ) { if ( 0 != daemon( true, false ) ) { logf( XW_LOGERROR, "dev() => %s", strerror(errno) ); exit( -1 ); } } #ifdef SPAWN_SELF /* loop forever, relaunching children as they die. */ while ( doFork ) { pid_t pid = fork(); if ( pid == 0 ) { /* child */ break; } else if ( pid > 0 ) { int status; logf( XW_LOGINFO, "parent waiting on child pid=%d", pid ); time_t time_before = time( NULL ); waitpid( pid, &status, 0 ); printWhy( status ); time_t time_after = time( NULL ); doFork = time_after > time_before; if ( !doFork ) { logf( XW_LOGERROR, "exiting b/c respawned too quickly" ); } } else { logf( XW_LOGERROR, "fork() => %s", strerror(errno) ); } } #endif /* Arrange to be sent SIGUSR1 on death of parent. */ prctl( PR_SET_PDEATHSIG, SIGUSR1 ); struct sigaction sact; memset( &sact, 0, sizeof(sact) ); sact.sa_handler = parentDied; (void)sigaction( SIGUSR1, &sact, NULL ); if ( port != 0 ) { g_listeners.AddListener( port ); } vector ints; if ( !cfg->GetValueFor( "PORTS", ints ) ) { exit( 1 ); } vector::const_iterator iter; for ( iter = ints.begin(); iter != ints.end(); ++iter ) { int port = *iter; if ( !g_listeners.PortInUse( port ) ) { g_listeners.AddListener( port ); } else { logf( XW_LOGERROR, "port %d was in use", port ); } } g_control = make_socket( INADDR_LOOPBACK, ctrlport ); if ( g_control == -1 ) { exit( 1 ); } #ifdef DO_HTTP int addr; if ( cfg->GetValueFor( "WWW_LISTEN_ADDR", &addr ) ) { g_http = make_socket( addr, httpport ); if ( g_http == -1 ) { exit( 1 ); } } #endif struct sigaction act; memset( &act, 0, sizeof(act) ); act.sa_handler = SIGINT_handler; int err = sigaction( SIGINT, &act, NULL ); logf( XW_LOGERROR, "sigaction=>%d", err ); XWThreadPool* tPool = XWThreadPool::GetTPool(); tPool->Setup( nWorkerThreads, processMessage ); /* set up select call */ fd_set rfds; for ( ; ; ) { FD_ZERO(&rfds); g_listeners.AddToFDSet( &rfds ); FD_SET( g_control, &rfds ); #ifdef DO_HTTP FD_SET( g_http, &rfds ); #endif int highest = g_listeners.GetHighest(); if ( g_control > highest ) { highest = g_control; } #ifdef DO_HTTP if ( g_http > highest ) { highest = g_http; } #endif ++highest; int retval = select( highest, &rfds, NULL, NULL, NULL ); if ( retval < 0 ) { if ( errno != 4 ) { /* 4's what we get when signal interrupts */ logf( XW_LOGINFO, "errno: %s (%d)", strerror(errno), errno ); } } else { ListenersIter iter(&g_listeners, true); while ( retval > 0 ) { int listener = iter.next(); if ( listener < 0 ) { break; } if ( FD_ISSET( listener, &rfds ) ) { struct sockaddr_in newaddr; socklen_t siz = sizeof(newaddr); int newSock = accept( listener, (sockaddr*)&newaddr, &siz ); logf( XW_LOGINFO, "accepting connection from %s", inet_ntoa(newaddr.sin_addr) ); tPool->AddSocket( newSock ); --retval; } } if ( FD_ISSET( g_control, &rfds ) ) { run_ctrl_thread( g_control ); --retval; } #ifdef DO_HTTP if ( FD_ISSET( g_http, &rfds ) ) { run_http_thread( g_http ); --retval; } #endif assert( retval == 0 ); } } g_listeners.RemoveAll(); close( g_control ); delete cfg; return 0; } // main