247 lines
6.0 KiB
C
247 lines
6.0 KiB
C
/*-
|
|
* Copyright (c) 1999 Berkeley Software Design, Inc. All rights reserved.
|
|
*
|
|
* Redistribution and use in source and binary forms, with or without
|
|
* modification, are permitted provided that the following conditions
|
|
* are met:
|
|
* 1. Redistributions of source code must retain the above copyright
|
|
* notice, this list of conditions and the following disclaimer.
|
|
* 2. Redistributions in binary form must reproduce the above copyright
|
|
* notice, this list of conditions and the following disclaimer in the
|
|
* documentation and/or other materials provided with the distribution.
|
|
* 3. Berkeley Software Design Inc's name may not be used to endorse or
|
|
* promote products derived from this software without specific prior
|
|
* written permission.
|
|
*
|
|
* THIS SOFTWARE IS PROVIDED BY BERKELEY SOFTWARE DESIGN INC ``AS IS'' AND
|
|
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
|
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
|
|
* ARE DISCLAIMED. IN NO EVENT SHALL BERKELEY SOFTWARE DESIGN INC BE LIABLE
|
|
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
|
|
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
|
|
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
|
|
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
|
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
|
|
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
|
|
* SUCH DAMAGE.
|
|
*
|
|
* From BSDI: daemon.c,v 1.2 1996/08/15 01:11:09 jch Exp
|
|
*/
|
|
|
|
#include <sys/cdefs.h>
|
|
__FBSDID("$FreeBSD$");
|
|
|
|
#include <sys/param.h>
|
|
#include <sys/mman.h>
|
|
#include <sys/wait.h>
|
|
|
|
#include <err.h>
|
|
#include <errno.h>
|
|
#include <libutil.h>
|
|
#include <login_cap.h>
|
|
#include <pwd.h>
|
|
#include <signal.h>
|
|
#include <stdio.h>
|
|
#include <stdlib.h>
|
|
#include <unistd.h>
|
|
|
|
static void dummy_sighandler(int);
|
|
static void restrict_process(const char *);
|
|
static int wait_child(pid_t pid, sigset_t *mask);
|
|
static void usage(void);
|
|
|
|
int
|
|
main(int argc, char *argv[])
|
|
{
|
|
struct pidfh *pfh = NULL;
|
|
sigset_t mask, oldmask;
|
|
int ch, nochdir, noclose, restart;
|
|
const char *pidfile, *user;
|
|
pid_t otherpid, pid;
|
|
|
|
nochdir = noclose = 1;
|
|
restart = 0;
|
|
pidfile = user = NULL;
|
|
while ((ch = getopt(argc, argv, "-cfp:ru:")) != -1) {
|
|
switch (ch) {
|
|
case 'c':
|
|
nochdir = 0;
|
|
break;
|
|
case 'f':
|
|
noclose = 0;
|
|
break;
|
|
case 'p':
|
|
pidfile = optarg;
|
|
break;
|
|
case 'r':
|
|
restart = 1;
|
|
break;
|
|
case 'u':
|
|
user = optarg;
|
|
break;
|
|
default:
|
|
usage();
|
|
}
|
|
}
|
|
argc -= optind;
|
|
argv += optind;
|
|
|
|
if (argc == 0)
|
|
usage();
|
|
|
|
pfh = NULL;
|
|
/*
|
|
* Try to open the pidfile before calling daemon(3),
|
|
* to be able to report the error intelligently
|
|
*/
|
|
if (pidfile != NULL) {
|
|
pfh = pidfile_open(pidfile, 0600, &otherpid);
|
|
if (pfh == NULL) {
|
|
if (errno == EEXIST) {
|
|
errx(3, "process already running, pid: %d",
|
|
otherpid);
|
|
}
|
|
err(2, "pidfile ``%s''", pidfile);
|
|
}
|
|
}
|
|
|
|
if (daemon(nochdir, noclose) == -1)
|
|
err(1, NULL);
|
|
|
|
/*
|
|
* If the pidfile or restart option is specified the daemon
|
|
* executes the command in a forked process and wait on child
|
|
* exit to remove the pidfile or restart the command. Normally
|
|
* we don't want the monitoring daemon to be terminated
|
|
* leaving the running process and the stale pidfile, so we
|
|
* catch SIGTERM and forward it to the children expecting to
|
|
* get SIGCHLD eventually.
|
|
*/
|
|
pid = -1;
|
|
if (pidfile != NULL || restart) {
|
|
/*
|
|
* Restore default action for SIGTERM in case the
|
|
* parent process decided to ignore it.
|
|
*/
|
|
if (signal(SIGTERM, SIG_DFL) == SIG_ERR)
|
|
err(1, "signal");
|
|
/*
|
|
* Because SIGCHLD is ignored by default, setup dummy handler
|
|
* for it, so we can mask it.
|
|
*/
|
|
if (signal(SIGCHLD, dummy_sighandler) == SIG_ERR)
|
|
err(1, "signal");
|
|
/*
|
|
* Block interesting signals.
|
|
*/
|
|
sigemptyset(&mask);
|
|
sigaddset(&mask, SIGTERM);
|
|
sigaddset(&mask, SIGCHLD);
|
|
if (sigprocmask(SIG_SETMASK, &mask, &oldmask) == -1)
|
|
err(1, "sigprocmask");
|
|
/*
|
|
* Try to protect against pageout kill. Ignore the
|
|
* error, madvise(2) will fail only if a process does
|
|
* not have superuser privileges.
|
|
*/
|
|
(void)madvise(NULL, 0, MADV_PROTECT);
|
|
restart:
|
|
/*
|
|
* Spawn a child to exec the command, so in the parent
|
|
* we could wait for it to exit and remove pidfile.
|
|
*/
|
|
pid = fork();
|
|
if (pid == -1) {
|
|
pidfile_remove(pfh);
|
|
err(1, "fork");
|
|
}
|
|
}
|
|
if (pid <= 0) {
|
|
if (pid == 0) {
|
|
/* Restore old sigmask in the child. */
|
|
if (sigprocmask(SIG_SETMASK, &oldmask, NULL) == -1)
|
|
err(1, "sigprocmask");
|
|
}
|
|
/* Now that we are the child, write out the pid. */
|
|
pidfile_write(pfh);
|
|
|
|
if (user != NULL)
|
|
restrict_process(user);
|
|
|
|
execvp(argv[0], argv);
|
|
|
|
/*
|
|
* execvp() failed -- report the error. The child is
|
|
* now running, so the exit status doesn't matter.
|
|
*/
|
|
err(1, "%s", argv[0]);
|
|
}
|
|
setproctitle("%s[%d]", argv[0], pid);
|
|
if (wait_child(pid, &mask) == 0 && restart) {
|
|
sleep(1);
|
|
goto restart;
|
|
}
|
|
pidfile_remove(pfh);
|
|
exit(0); /* Exit status does not matter. */
|
|
}
|
|
|
|
static void
|
|
dummy_sighandler(int sig __unused)
|
|
{
|
|
/* Nothing to do. */
|
|
}
|
|
|
|
static void
|
|
restrict_process(const char *user)
|
|
{
|
|
struct passwd *pw = NULL;
|
|
|
|
pw = getpwnam(user);
|
|
if (pw == NULL)
|
|
errx(1, "unknown user: %s", user);
|
|
|
|
if (setusercontext(NULL, pw, pw->pw_uid, LOGIN_SETALL) != 0)
|
|
errx(1, "failed to set user environment");
|
|
}
|
|
|
|
static int
|
|
wait_child(pid_t pid, sigset_t *mask)
|
|
{
|
|
int terminate, signo;
|
|
|
|
terminate = 0;
|
|
for (;;) {
|
|
if (sigwait(mask, &signo) == -1) {
|
|
warn("sigwaitinfo");
|
|
return (-1);
|
|
}
|
|
switch (signo) {
|
|
case SIGCHLD:
|
|
if (waitpid(pid, NULL, WNOHANG) == -1) {
|
|
warn("waitpid");
|
|
return (-1);
|
|
}
|
|
return (terminate);
|
|
case SIGTERM:
|
|
terminate = 1;
|
|
if (kill(pid, signo) == -1) {
|
|
warn("kill");
|
|
return (-1);
|
|
}
|
|
continue;
|
|
default:
|
|
warnx("sigwaitinfo: invalid signal: %d", signo);
|
|
return (-1);
|
|
}
|
|
}
|
|
}
|
|
|
|
static void
|
|
usage(void)
|
|
{
|
|
(void)fprintf(stderr,
|
|
"usage: daemon [-cf] [-p pidfile] [-u user] command "
|
|
"arguments ...\n");
|
|
exit(1);
|
|
}
|