/* direvent - directory content watcher daemon
Copyright (C) 2012-2016 Sergey Poznyakoff
Direvent 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 3 of the License, or (at your
option) any later version.
Direvent 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 direvent. If not, see . */
/* "Early-init" detach() for BSD systems. It uses rfork instead of fork
to ensure the event queue is inherited by the child process. According
to the kqueue(2) manpage:
The kqueue() system call creates a new kernel event queue and returns a
descriptor. The queue is not inherited by a child created with fork(2).
However, if rfork(2) is called without the RFFDG flag, then the descrip-
tor table is shared, which will allow sharing of the kqueue between two
processes.
*/
#include "direvent.h"
#include
#include
#include
#include
#include
#ifdef HAVE_PATHS_H
# include
#endif
#ifndef _PATH_DEVNULL
# define _PATH_DEVNULL "/dev/null"
#endif
int
detach(void (*init)())
{
struct sigaction oldsa, sa;
pid_t pid;
int ec;
init();
sigemptyset(&sa.sa_mask);
sa.sa_handler = SIG_IGN;
sa.sa_flags = 0;
if (sigaction(SIGHUP, &sa, &oldsa))
return -1;
switch (rfork(RFPROC)) {
case -1:
return -1;
case 0:
break;
default:
_exit(0);
}
pid = setsid();
ec = errno;
sigaction(SIGHUP, &oldsa, NULL);
if (pid == -1) {
errno = ec;
return -1;
}
chdir("/");
close(0);
close(1);
close(2);
open(_PATH_DEVNULL, O_RDONLY);
open(_PATH_DEVNULL, O_WRONLY);
dup(1);
return 0;
}