1/*-
2 * Copyright (c) 1999 Berkeley Software Design, Inc. All rights reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
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
14 * written permission.
15 *
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
24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 *
28 * From BSDI: daemon.c,v 1.2 1996/08/15 01:11:09 jch Exp
29 */
30
31#include <sys/cdefs.h>
32__FBSDID("$FreeBSD: head/usr.sbin/daemon/daemon.c 255521 2013-09-13 16:57:28Z jmg $");
33
34#include <sys/param.h>
35#include <sys/mman.h>
36#include <sys/wait.h>
37
38#include <err.h>
39#include <errno.h>
40#include <libutil.h>
41#include <login_cap.h>
42#include <pwd.h>
43#include <signal.h>
44#include <stdio.h>
45#include <stdlib.h>
46#include <unistd.h>
47
48static void dummy_sighandler(int);
49static void restrict_process(const char *);
50static int wait_child(pid_t pid, sigset_t *mask);
51static void usage(void);
52
53int
54main(int argc, char *argv[])
55{
56 struct pidfh *ppfh, *pfh;
57 sigset_t mask, oldmask;
58 int ch, nochdir, noclose, restart;
59 const char *pidfile, *ppidfile, *user;
60 pid_t otherpid, pid;
61
62 nochdir = noclose = 1;
63 restart = 0;
64 ppfh = pfh = NULL;
65 ppidfile = pidfile = user = NULL;
66 while ((ch = getopt(argc, argv, "cfp:P:ru:")) != -1) {
67 switch (ch) {
68 case 'c':
69 nochdir = 0;
70 break;
71 case 'f':
72 noclose = 0;
73 break;
74 case 'p':
75 pidfile = optarg;
76 break;
77 case 'P':
78 ppidfile = optarg;
79 break;
80 case 'r':
81 restart = 1;
82 break;
83 case 'u':
84 user = optarg;
85 break;
86 default:
87 usage();
88 }
89 }
90 argc -= optind;
91 argv += optind;
92
93 if (argc == 0)
94 usage();
95
96 ppfh = pfh = NULL;
97 /*
98 * Try to open the pidfile before calling daemon(3),
99 * to be able to report the error intelligently
100 */
101 if (pidfile != NULL) {
102 pfh = pidfile_open(pidfile, 0600, &otherpid);
103 if (pfh == NULL) {
104 if (errno == EEXIST) {
105 errx(3, "process already running, pid: %d",
106 otherpid);
107 }
108 err(2, "pidfile ``%s''", pidfile);
109 }
110 }
111
112 /* do same for actual daemon process */
113 if (ppidfile != NULL) {
114 ppfh = pidfile_open(ppidfile, 0600, &otherpid);
115 if (ppfh == NULL) {
116 if (errno == EEXIST) {
117 errx(3, "process already running, pid: %d",
118 otherpid);
119 }
120 err(2, "ppidfile ``%s''", ppidfile);
121 }
122 }
123
124 if (daemon(nochdir, noclose) == -1)
125 err(1, NULL);
126
127 /*
128 * If the pidfile or restart option is specified the daemon
129 * executes the command in a forked process and wait on child
130 * exit to remove the pidfile or restart the command. Normally
131 * we don't want the monitoring daemon to be terminated
132 * leaving the running process and the stale pidfile, so we
133 * catch SIGTERM and forward it to the children expecting to
134 * get SIGCHLD eventually.
135 */
136 pid = -1;
137 if (pidfile != NULL || restart) {
138 /*
139 * Restore default action for SIGTERM in case the
140 * parent process decided to ignore it.
141 */
142 if (signal(SIGTERM, SIG_DFL) == SIG_ERR)
143 err(1, "signal");
144 /*
145 * Because SIGCHLD is ignored by default, setup dummy handler
146 * for it, so we can mask it.
147 */
148 if (signal(SIGCHLD, dummy_sighandler) == SIG_ERR)
149 err(1, "signal");
150 /*
151 * Block interesting signals.
152 */
153 sigemptyset(&mask);
154 sigaddset(&mask, SIGTERM);
155 sigaddset(&mask, SIGCHLD);
156 if (sigprocmask(SIG_SETMASK, &mask, &oldmask) == -1)
157 err(1, "sigprocmask");
158 /*
159 * Try to protect against pageout kill. Ignore the
160 * error, madvise(2) will fail only if a process does
161 * not have superuser privileges.
162 */
163 (void)madvise(NULL, 0, MADV_PROTECT);
164restart:
165 /*
166 * Spawn a child to exec the command, so in the parent
167 * we could wait for it to exit and remove pidfile.
168 */
169 pid = fork();
170 if (pid == -1) {
171 pidfile_remove(pfh);
172 err(1, "fork");
173 }
174 }
175 if (pid <= 0) {
176 if (pid == 0) {
177 /* Restore old sigmask in the child. */
178 if (sigprocmask(SIG_SETMASK, &oldmask, NULL) == -1)
179 err(1, "sigprocmask");
180 }
181 /* Now that we are the child, write out the pid. */
182 pidfile_write(pfh);
183
184 if (user != NULL)
185 restrict_process(user);
186
187 execvp(argv[0], argv);
188
189 /*
190 * execvp() failed -- report the error. The child is
191 * now running, so the exit status doesn't matter.
192 */
193 err(1, "%s", argv[0]);
194 }
195 /* write out parent pidfile if needed */
196 if (ppidfile != NULL)
197 pidfile_write(ppfh);
198
199 setproctitle("%s[%d]", argv[0], pid);
200 if (wait_child(pid, &mask) == 0 && restart) {
201 sleep(1);
202 goto restart;
203 }
204 pidfile_remove(pfh);
205 pidfile_remove(ppfh);
206 exit(0); /* Exit status does not matter. */
207}
208
209static void
210dummy_sighandler(int sig __unused)
211{
212 /* Nothing to do. */
213}
214
215static void
216restrict_process(const char *user)
217{
218 struct passwd *pw = NULL;
219
220 pw = getpwnam(user);
221 if (pw == NULL)
222 errx(1, "unknown user: %s", user);
223
224 if (setusercontext(NULL, pw, pw->pw_uid, LOGIN_SETALL) != 0)
225 errx(1, "failed to set user environment");
226}
227
228static int
229wait_child(pid_t pid, sigset_t *mask)
230{
231 int terminate, signo;
232
233 terminate = 0;
234 for (;;) {
235 if (sigwait(mask, &signo) == -1) {
236 warn("sigwaitinfo");
237 return (-1);
238 }
239 switch (signo) {
240 case SIGCHLD:
241 if (waitpid(pid, NULL, WNOHANG) == -1) {
242 warn("waitpid");
243 return (-1);
244 }
245 return (terminate);
246 case SIGTERM:
247 terminate = 1;
248 if (kill(pid, signo) == -1) {
249 warn("kill");
250 return (-1);
251 }
252 continue;
253 default:
254 warnx("sigwaitinfo: invalid signal: %d", signo);
255 return (-1);
256 }
257 }
258}
259
260static void
261usage(void)
262{
263 (void)fprintf(stderr,
264 "usage: daemon [-cfr] [-p child_pidfile] [-P supervisor_pidfile] "
265 "[-u user]\n command arguments ...\n");
266 exit(1);
267}
2 * Copyright (c) 1999 Berkeley Software Design, Inc. All rights reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
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
14 * written permission.
15 *
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
24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 *
28 * From BSDI: daemon.c,v 1.2 1996/08/15 01:11:09 jch Exp
29 */
30
31#include <sys/cdefs.h>
32__FBSDID("$FreeBSD: head/usr.sbin/daemon/daemon.c 255521 2013-09-13 16:57:28Z jmg $");
33
34#include <sys/param.h>
35#include <sys/mman.h>
36#include <sys/wait.h>
37
38#include <err.h>
39#include <errno.h>
40#include <libutil.h>
41#include <login_cap.h>
42#include <pwd.h>
43#include <signal.h>
44#include <stdio.h>
45#include <stdlib.h>
46#include <unistd.h>
47
48static void dummy_sighandler(int);
49static void restrict_process(const char *);
50static int wait_child(pid_t pid, sigset_t *mask);
51static void usage(void);
52
53int
54main(int argc, char *argv[])
55{
56 struct pidfh *ppfh, *pfh;
57 sigset_t mask, oldmask;
58 int ch, nochdir, noclose, restart;
59 const char *pidfile, *ppidfile, *user;
60 pid_t otherpid, pid;
61
62 nochdir = noclose = 1;
63 restart = 0;
64 ppfh = pfh = NULL;
65 ppidfile = pidfile = user = NULL;
66 while ((ch = getopt(argc, argv, "cfp:P:ru:")) != -1) {
67 switch (ch) {
68 case 'c':
69 nochdir = 0;
70 break;
71 case 'f':
72 noclose = 0;
73 break;
74 case 'p':
75 pidfile = optarg;
76 break;
77 case 'P':
78 ppidfile = optarg;
79 break;
80 case 'r':
81 restart = 1;
82 break;
83 case 'u':
84 user = optarg;
85 break;
86 default:
87 usage();
88 }
89 }
90 argc -= optind;
91 argv += optind;
92
93 if (argc == 0)
94 usage();
95
96 ppfh = pfh = NULL;
97 /*
98 * Try to open the pidfile before calling daemon(3),
99 * to be able to report the error intelligently
100 */
101 if (pidfile != NULL) {
102 pfh = pidfile_open(pidfile, 0600, &otherpid);
103 if (pfh == NULL) {
104 if (errno == EEXIST) {
105 errx(3, "process already running, pid: %d",
106 otherpid);
107 }
108 err(2, "pidfile ``%s''", pidfile);
109 }
110 }
111
112 /* do same for actual daemon process */
113 if (ppidfile != NULL) {
114 ppfh = pidfile_open(ppidfile, 0600, &otherpid);
115 if (ppfh == NULL) {
116 if (errno == EEXIST) {
117 errx(3, "process already running, pid: %d",
118 otherpid);
119 }
120 err(2, "ppidfile ``%s''", ppidfile);
121 }
122 }
123
124 if (daemon(nochdir, noclose) == -1)
125 err(1, NULL);
126
127 /*
128 * If the pidfile or restart option is specified the daemon
129 * executes the command in a forked process and wait on child
130 * exit to remove the pidfile or restart the command. Normally
131 * we don't want the monitoring daemon to be terminated
132 * leaving the running process and the stale pidfile, so we
133 * catch SIGTERM and forward it to the children expecting to
134 * get SIGCHLD eventually.
135 */
136 pid = -1;
137 if (pidfile != NULL || restart) {
138 /*
139 * Restore default action for SIGTERM in case the
140 * parent process decided to ignore it.
141 */
142 if (signal(SIGTERM, SIG_DFL) == SIG_ERR)
143 err(1, "signal");
144 /*
145 * Because SIGCHLD is ignored by default, setup dummy handler
146 * for it, so we can mask it.
147 */
148 if (signal(SIGCHLD, dummy_sighandler) == SIG_ERR)
149 err(1, "signal");
150 /*
151 * Block interesting signals.
152 */
153 sigemptyset(&mask);
154 sigaddset(&mask, SIGTERM);
155 sigaddset(&mask, SIGCHLD);
156 if (sigprocmask(SIG_SETMASK, &mask, &oldmask) == -1)
157 err(1, "sigprocmask");
158 /*
159 * Try to protect against pageout kill. Ignore the
160 * error, madvise(2) will fail only if a process does
161 * not have superuser privileges.
162 */
163 (void)madvise(NULL, 0, MADV_PROTECT);
164restart:
165 /*
166 * Spawn a child to exec the command, so in the parent
167 * we could wait for it to exit and remove pidfile.
168 */
169 pid = fork();
170 if (pid == -1) {
171 pidfile_remove(pfh);
172 err(1, "fork");
173 }
174 }
175 if (pid <= 0) {
176 if (pid == 0) {
177 /* Restore old sigmask in the child. */
178 if (sigprocmask(SIG_SETMASK, &oldmask, NULL) == -1)
179 err(1, "sigprocmask");
180 }
181 /* Now that we are the child, write out the pid. */
182 pidfile_write(pfh);
183
184 if (user != NULL)
185 restrict_process(user);
186
187 execvp(argv[0], argv);
188
189 /*
190 * execvp() failed -- report the error. The child is
191 * now running, so the exit status doesn't matter.
192 */
193 err(1, "%s", argv[0]);
194 }
195 /* write out parent pidfile if needed */
196 if (ppidfile != NULL)
197 pidfile_write(ppfh);
198
199 setproctitle("%s[%d]", argv[0], pid);
200 if (wait_child(pid, &mask) == 0 && restart) {
201 sleep(1);
202 goto restart;
203 }
204 pidfile_remove(pfh);
205 pidfile_remove(ppfh);
206 exit(0); /* Exit status does not matter. */
207}
208
209static void
210dummy_sighandler(int sig __unused)
211{
212 /* Nothing to do. */
213}
214
215static void
216restrict_process(const char *user)
217{
218 struct passwd *pw = NULL;
219
220 pw = getpwnam(user);
221 if (pw == NULL)
222 errx(1, "unknown user: %s", user);
223
224 if (setusercontext(NULL, pw, pw->pw_uid, LOGIN_SETALL) != 0)
225 errx(1, "failed to set user environment");
226}
227
228static int
229wait_child(pid_t pid, sigset_t *mask)
230{
231 int terminate, signo;
232
233 terminate = 0;
234 for (;;) {
235 if (sigwait(mask, &signo) == -1) {
236 warn("sigwaitinfo");
237 return (-1);
238 }
239 switch (signo) {
240 case SIGCHLD:
241 if (waitpid(pid, NULL, WNOHANG) == -1) {
242 warn("waitpid");
243 return (-1);
244 }
245 return (terminate);
246 case SIGTERM:
247 terminate = 1;
248 if (kill(pid, signo) == -1) {
249 warn("kill");
250 return (-1);
251 }
252 continue;
253 default:
254 warnx("sigwaitinfo: invalid signal: %d", signo);
255 return (-1);
256 }
257 }
258}
259
260static void
261usage(void)
262{
263 (void)fprintf(stderr,
264 "usage: daemon [-cfr] [-p child_pidfile] [-P supervisor_pidfile] "
265 "[-u user]\n command arguments ...\n");
266 exit(1);
267}