2 * Copyright (c) 1999 Berkeley Software Design, Inc. All rights reserved.
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
7 * 1. Redistributions of source code must retain the above copyright
8 * notice, this list of conditions and the following disclaimer.
9 * 2. Redistributions in binary form must reproduce the above copyright
10 * notice, this list of conditions and the following disclaimer in the
11 * documentation and/or other materials provided with the distribution.
12 * 3. Berkeley Software Design Inc's name may not be used to endorse or
13 * promote products derived from this software without specific prior
16 * THIS SOFTWARE IS PROVIDED BY BERKELEY SOFTWARE DESIGN INC ``AS IS'' AND
17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED. IN NO EVENT SHALL BERKELEY SOFTWARE DESIGN INC BE LIABLE
20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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28 * From BSDI: daemon.c,v 1.2 1996/08/15 01:11:09 jch Exp
31 #include <sys/cdefs.h>
32 __FBSDID("$FreeBSD$");
34 #include <sys/param.h>
41 #include <login_cap.h>
48 static void dummy_sighandler(int);
49 static void restrict_process(const char *);
50 static int wait_child(pid_t pid, sigset_t *mask);
51 static void usage(void);
54 main(int argc, char *argv[])
56 struct pidfh *pfh = NULL;
57 sigset_t mask, oldmask;
58 int ch, nochdir, noclose, restart;
59 const char *pidfile, *user;
62 nochdir = noclose = 1;
64 pidfile = user = NULL;
65 while ((ch = getopt(argc, argv, "-cfp:ru:")) != -1) {
94 * Try to open the pidfile before calling daemon(3),
95 * to be able to report the error intelligently
97 if (pidfile != NULL) {
98 pfh = pidfile_open(pidfile, 0600, &otherpid);
100 if (errno == EEXIST) {
101 errx(3, "process already running, pid: %d",
104 err(2, "pidfile ``%s''", pidfile);
108 if (daemon(nochdir, noclose) == -1)
112 * If the pidfile or restart option is specified the daemon
113 * executes the command in a forked process and wait on child
114 * exit to remove the pidfile or restart the command. Normally
115 * we don't want the monitoring daemon to be terminated
116 * leaving the running process and the stale pidfile, so we
117 * catch SIGTERM and forward it to the children expecting to
118 * get SIGCHLD eventually.
121 if (pidfile != NULL || restart) {
123 * Restore default action for SIGTERM in case the
124 * parent process decided to ignore it.
126 if (signal(SIGTERM, SIG_DFL) == SIG_ERR)
129 * Because SIGCHLD is ignored by default, setup dummy handler
130 * for it, so we can mask it.
132 if (signal(SIGCHLD, dummy_sighandler) == SIG_ERR)
135 * Block interesting signals.
138 sigaddset(&mask, SIGTERM);
139 sigaddset(&mask, SIGCHLD);
140 if (sigprocmask(SIG_SETMASK, &mask, &oldmask) == -1)
141 err(1, "sigprocmask");
143 * Try to protect against pageout kill. Ignore the
144 * error, madvise(2) will fail only if a process does
145 * not have superuser privileges.
147 (void)madvise(NULL, 0, MADV_PROTECT);
150 * Spawn a child to exec the command, so in the parent
151 * we could wait for it to exit and remove pidfile.
161 /* Restore old sigmask in the child. */
162 if (sigprocmask(SIG_SETMASK, &oldmask, NULL) == -1)
163 err(1, "sigprocmask");
165 /* Now that we are the child, write out the pid. */
169 restrict_process(user);
171 execvp(argv[0], argv);
174 * execvp() failed -- report the error. The child is
175 * now running, so the exit status doesn't matter.
177 err(1, "%s", argv[0]);
179 setproctitle("%s[%d]", argv[0], pid);
180 if (wait_child(pid, &mask) == 0 && restart) {
185 exit(0); /* Exit status does not matter. */
189 dummy_sighandler(int sig __unused)
195 restrict_process(const char *user)
197 struct passwd *pw = NULL;
201 errx(1, "unknown user: %s", user);
203 if (setusercontext(NULL, pw, pw->pw_uid, LOGIN_SETALL) != 0)
204 errx(1, "failed to set user environment");
208 wait_child(pid_t pid, sigset_t *mask)
210 int terminate, signo;
214 if (sigwait(mask, &signo) == -1) {
220 if (waitpid(pid, NULL, WNOHANG) == -1) {
227 if (kill(pid, signo) == -1) {
233 warnx("sigwaitinfo: invalid signal: %d", signo);
242 (void)fprintf(stderr,
243 "usage: daemon [-cfr] [-p pidfile] [-u user] command "