transmission/daemon/daemon.c

383 lines
9.3 KiB
C

/******************************************************************************
* $Id$
*
* Copyright (c) 2007 Joshua Elsasser
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
* and/or sell copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
* DEALINGS IN THE SOFTWARE.
*****************************************************************************/
#include <sys/types.h>
#include <sys/param.h>
#include <sys/stat.h>
#include <sys/socket.h>
#include <sys/time.h>
#include <sys/uio.h>
#include <sys/un.h>
#include <assert.h>
#include <errno.h>
#include <event.h>
#include <fcntl.h>
#include <getopt.h>
#include <signal.h>
#include <stdarg.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <libtransmission/trcompat.h>
#include <libtransmission/version.h>
#include "errors.h"
#include "misc.h"
#include "server.h"
#include "torrents.h"
static void usage ( const char *, ... );
static void readargs ( int, char **, int *, int *, char **, char ** );
static int trylocksock ( const char * );
static int getlock ( const char * );
static int getsock ( const char * );
static void exitcleanup ( void );
static void setupsigs ( struct event_base * );
static void gotsig ( int, short, void * );
static int savepid ( const char * );
static int gl_lockfd = -1;
static char gl_lockpath[MAXPATHLEN] = "";
static int gl_sockfd = -1;
static char gl_sockpath[MAXPATHLEN] = "";
static char gl_pidfile[MAXPATHLEN] = "";
int
main( int argc, char ** argv )
{
struct event_base * evbase;
int nofork, debug, sockfd;
char * sockpath, * pidfile;
setmyname( argv[0] );
readargs( argc, argv, &nofork, &debug, &sockpath, &pidfile );
if( !nofork )
{
if( 0 > daemon( 1, 0 ) )
{
errnomsg( "failed to daemonize" );
exit( 1 );
}
errsyslog( 1 );
}
atexit( exitcleanup );
sockfd = trylocksock( sockpath );
if( 0 > sockfd )
{
exit( 1 );
}
if( NULL != pidfile && 0 > savepid( pidfile ) )
{
exit( 1 );
}
evbase = event_init();
setupsigs( evbase );
torrent_init( evbase );
server_init( evbase );
server_debug( debug );
server_listen( sockfd );
event_base_dispatch( evbase );
return 1;
}
void
usage( const char * msg, ... )
{
va_list ap;
if( NULL != msg )
{
printf( "%s: ", getmyname() );
va_start( ap, msg );
vprintf( msg, ap );
va_end( ap );
printf( "\n" );
}
printf(
"usage: %s [-dfh] [-p file] [-s file]\n"
"\n"
"Transmission %s http://transmission.m0k.org/\n"
"A free, lightweight BitTorrent client with a simple, intuitive interface\n"
"\n"
" -d --debug Print data send and received, implies -f\n"
" -f --foreground Run in the foreground and log to stderr\n"
" -h --help Display this message and exit\n"
" -p --pidfile <path> Save the process id in a file at <path>\n"
" -s --socket <path> Place the socket file at <path>\n"
"\n"
"To add torrents or set options, use the transmission-remote program.\n",
getmyname(), LONG_VERSION_STRING );
exit( 0 );
}
void
readargs( int argc, char ** argv, int * nofork, int * debug, char ** sock,
char ** pidfile )
{
char optstr[] = "dfhp:s:";
struct option longopts[] =
{
{ "debug", no_argument, NULL, 'd' },
{ "foreground", no_argument, NULL, 'f' },
{ "help", no_argument, NULL, 'h' },
{ "pidfile", required_argument, NULL, 'p' },
{ "socket", required_argument, NULL, 's' },
{ NULL, 0, NULL, 0 }
};
int opt;
*nofork = 0;
*debug = 0;
*sock = NULL;
*pidfile = NULL;
while( 0 <= ( opt = getopt_long( argc, argv, optstr, longopts, NULL ) ) )
{
switch( opt )
{
case 'd':
*debug = 1;
/* FALLTHROUGH */
case 'f':
*nofork = 1;
break;
case 'p':
*pidfile = optarg;
break;
case 's':
*sock = optarg;
break;
default:
usage( NULL );
break;
}
}
}
int
trylocksock( const char * sockpath )
{
char path[MAXPATHLEN];
int fd;
confpath( path, sizeof path, NULL, CONF_PATH_TYPE_DAEMON );
if( 0 > mkdir( path, 0777 ) && EEXIST != errno )
{
errnomsg( "failed to create directory: %s", path );
return -1;
}
confpath( path, sizeof path, CONF_FILE_LOCK, 0 );
fd = getlock( path );
if( 0 > fd )
{
return -1;
}
gl_lockfd = fd;
strlcpy( gl_lockpath, path, sizeof gl_lockpath );
if( NULL == sockpath )
{
confpath( path, sizeof path, CONF_FILE_SOCKET, 0 );
sockpath = path;
}
fd = getsock( sockpath );
if( 0 > fd )
{
return -1;
}
gl_sockfd = fd;
strlcpy( gl_sockpath, sockpath, sizeof gl_sockpath );
return fd;
}
int
getlock( const char * path )
{
struct flock lk;
int fd;
char pid[64];
fd = open( path, O_RDWR | O_CREAT, 0666 );
if( 0 > fd )
{
errnomsg( "failed to open file: %s", path );
return -1;
}
memset( &lk, 0, sizeof lk );
lk.l_start = 0;
lk.l_len = 0;
lk.l_type = F_WRLCK;
lk.l_whence = SEEK_SET;
if( 0 > fcntl( fd, F_SETLK, &lk ) )
{
if( EAGAIN == errno )
{
errmsg( "another copy of %s is already running", getmyname() );
}
else
{
errnomsg( "failed to obtain lock on file: %s", path );
}
close( fd );
return -1;
}
ftruncate( fd, 0 );
snprintf( pid, sizeof pid, "%i\n", getpid() );
write( fd, pid, strlen( pid ) );
return fd;
}
int
getsock( const char * path )
{
struct sockaddr_un sa;
int fd;
fd = socket( PF_LOCAL, SOCK_STREAM, 0 );
if( 0 > fd )
{
errnomsg( "failed to create socket file: %s", path );
return -1;
}
memset( &sa, 0, sizeof sa );
sa.sun_family = AF_LOCAL;
strlcpy( sa.sun_path, path, sizeof sa.sun_path );
unlink( path );
if( 0 > bind( fd, ( struct sockaddr * )&sa, SUN_LEN( &sa ) ) )
{
/* bind can sometimes fail on the first call */
unlink( path );
if( 0 > bind( fd, ( struct sockaddr * )&sa, SUN_LEN( &sa ) ) )
{
errnomsg( "failed to bind socket file: %s", path );
close( fd );
return -1;
}
}
return fd;
}
void
exitcleanup( void )
{
if( 0 <= gl_sockfd )
{
unlink( gl_sockpath );
close( gl_sockfd );
}
if( 0 != gl_pidfile[0] )
{
unlink( gl_pidfile );
}
if( 0 <= gl_lockfd )
{
unlink( gl_lockpath );
close( gl_lockfd );
}
}
void
setupsigs( struct event_base * base )
{
static struct event ev_int;
static struct event ev_quit;
static struct event ev_term;
signal_set( &ev_int, SIGINT, gotsig, NULL );
event_base_set( base, &ev_int );
signal_add( &ev_int, NULL );
signal_set( &ev_quit, SIGQUIT, gotsig, NULL );
event_base_set( base, &ev_quit );
signal_add( &ev_quit, NULL );
signal_set( &ev_term, SIGTERM, gotsig, NULL );
event_base_set( base, &ev_term );
signal_add( &ev_term, NULL );
signal( SIGPIPE, SIG_IGN );
signal( SIGHUP, SIG_IGN );
}
void
gotsig( int sig, short what UNUSED, void * arg UNUSED )
{
static int exiting = 0;
if( !exiting )
{
exiting = 1;
errmsg( "received fatal signal %i, attempting to exit cleanly", sig );
server_quit();
}
else
{
errmsg( "received fatal signal %i while exiting, exiting immediately",
sig );
signal( sig, SIG_DFL );
raise( sig );
}
}
int
savepid( const char * file )
{
FILE * pid;
pid = fopen( file, "wb" );
if( NULL == pid )
{
errnomsg( "failed to open pid file: %s", file );
return -1;
}
if( 0 > fprintf( pid, "%d\n", (int) getpid() ) )
{
errnomsg( "failed to write pid to file: %s", file );
fclose( pid );
unlink( file );
return -1;
}
fclose( pid );
strlcpy( gl_pidfile, file, sizeof gl_pidfile );
return 0;
}