xwords/xwords4/relay/xwrelay.cpp

830 lines
23 KiB
C++

/* -*-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 <stdio.h>
#include <unistd.h>
#include <netdb.h> /* gethostbyname */
#include <errno.h>
#include <signal.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <unistd.h>
#include <fcntl.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <stdlib.h>
#include <string.h>
#include <pthread.h>
#include <assert.h>
#include <sys/select.h>
#include <stdarg.h>
#include <syslog.h>
#include <sys/wait.h>
#include <sys/prctl.h>
#if defined(__FreeBSD__)
# if (OSVERSION > 500000)
# include "getopt.h"
# else
# include "unistd.h"
# endif
#else
# include <getopt.h>
#endif
#include <sys/time.h>
#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;
if ( !where ) {
where = fopen( LOG_FILE_PATH, "a" );
}
gettimeofday( &tv, NULL );
struct tm result;
timp = localtime_r( &tv.tv_sec, &result );
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 "<unknown>";
}
}
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
uptime( 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 <cport> (localhost port for control console)\\\n"
"\t-w <cport> (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 <conffile> (config file)\\\n"
"\t-h (print this help)\\\n"
"\t-i <idfile> (file where next global id stored)\\\n"
"\t-n <serverName> (used in permID generation)\\\n"
"\t-p <port> (port to listen on)\\\n"
"\t-t <nWorkerThreads> (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; signal: %d", WTERMSIG(status) );
} 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);
}
static void
handlePipe( int sig )
{
logf( XW_LOGINFO, "%s", __func__ );
}
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)uptime(); /* 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;
}
}
PermID::SetServerName( serverName );
PermID::SetStartTime( time(NULL) );
/* 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 );
memset( &sact, 0, sizeof(sact) );
sact.sa_handler = handlePipe;
(void)sigaction( SIGPIPE, &sact, NULL );
if ( port != 0 ) {
g_listeners.AddListener( port );
}
vector<int> ints;
if ( !cfg->GetValueFor( "PORTS", ints ) ) {
exit( 1 );
}
vector<int>::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