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    1: /* $Id: daemonize.c,v 1.1.1.3 2013/07/22 00:32:35 misho Exp $ */
    2: /* MiniUPnP project
    3:  * http://miniupnp.free.fr/ or http://miniupnp.tuxfamily.org/
    4:  * (c) 2006 Thomas Bernard
    5:  * This software is subject to the conditions detailed
    6:  * in the LICENCE file provided within the distribution */
    7: 
    8: #include <sys/types.h>
    9: #include <sys/stat.h>
   10: #include <unistd.h>
   11: #include <fcntl.h>
   12: #include <stdio.h>
   13: #include <stdlib.h>
   14: #include <syslog.h>
   15: #include <string.h>
   16: #include <signal.h>
   17: 
   18: #include "daemonize.h"
   19: #include "config.h"
   20: 
   21: #ifndef USE_DAEMON
   22: 
   23: int
   24: daemonize(void)
   25: {
   26: 	int pid, i;
   27: 
   28: 	switch(fork())
   29: 	{
   30: 	/* fork error */
   31: 	case -1:
   32: 		perror("fork()");
   33: 		exit(1);
   34: 
   35: 	/* child process */
   36: 	case 0:
   37: 		/* obtain a new process group */
   38: 		if( (pid = setsid()) < 0)
   39: 		{
   40: 			perror("setsid()");
   41: 			exit(1);
   42: 		}
   43: 
   44: 		/* close all descriptors */
   45: 		for (i=getdtablesize();i>=0;--i) close(i);
   46: 
   47: 		i = open("/dev/null", O_RDWR); /* open stdin */
   48: 		dup(i); /* stdout */
   49: 		dup(i); /* stderr */
   50: 
   51: 		umask(027);
   52: 		chdir("/"); /* chdir to /tmp ? */
   53: 
   54: 		return pid;
   55: 
   56: 	/* parent process */
   57: 	default:
   58: 		exit(0);
   59: 	}
   60: }
   61: #endif
   62: 
   63: int
   64: writepidfile(const char * fname, int pid)
   65: {
   66: 	char pidstring[16];
   67: 	int pidstringlen;
   68: 	int pidfile;
   69: 
   70: 	if(!fname || (strlen(fname) == 0))
   71: 		return -1;
   72: 
   73: 	if( (pidfile = open(fname, O_WRONLY|O_CREAT, 0644)) < 0)
   74: 	{
   75: 		syslog(LOG_ERR, "Unable to open pidfile for writing %s: %m", fname);
   76: 		return -1;
   77: 	}
   78: 
   79: 	pidstringlen = snprintf(pidstring, sizeof(pidstring), "%d\n", pid);
   80: 	if(pidstringlen <= 0)
   81: 	{
   82: 		syslog(LOG_ERR,
   83: 			"Unable to write to pidfile %s: snprintf(): FAILED", fname);
   84: 		close(pidfile);
   85: 		return -1;
   86: 	}
   87: 	else
   88: 	{
   89: 		if(write(pidfile, pidstring, pidstringlen) < 0)
   90: 			syslog(LOG_ERR, "Unable to write to pidfile %s: %m", fname);
   91: 	}
   92: 
   93: 	close(pidfile);
   94: 
   95: 	return 0;
   96: }
   97: 
   98: int
   99: checkforrunning(const char * fname)
  100: {
  101: 	char buffer[64];
  102: 	int pidfile;
  103: 	pid_t pid;
  104: 
  105: 	if(!fname || (strlen(fname) == 0))
  106: 		return -1;
  107: 
  108: 	if( (pidfile = open(fname, O_RDONLY)) < 0)
  109: 		return 0;
  110: 
  111: 	memset(buffer, 0, 64);
  112: 
  113: 	if(read(pidfile, buffer, 63))
  114: 	{
  115: 		if( (pid = atol(buffer)) > 0)
  116: 		{
  117: 			if(!kill(pid, 0))
  118: 			{
  119: 				close(pidfile);
  120: 				return -2;
  121: 			}
  122: 		}
  123: 	}
  124: 
  125: 	close(pidfile);
  126: 
  127: 	return 0;
  128: }
  129: