1bd06a3ecSMike Barcroft /*- 2bd06a3ecSMike Barcroft * Copyright (c) 1999 Berkeley Software Design, Inc. All rights reserved. 3bd06a3ecSMike Barcroft * 4bd06a3ecSMike Barcroft * Redistribution and use in source and binary forms, with or without 5bd06a3ecSMike Barcroft * modification, are permitted provided that the following conditions 6bd06a3ecSMike Barcroft * are met: 7bd06a3ecSMike Barcroft * 1. Redistributions of source code must retain the above copyright 8bd06a3ecSMike Barcroft * notice, this list of conditions and the following disclaimer. 9bd06a3ecSMike Barcroft * 2. Redistributions in binary form must reproduce the above copyright 10bd06a3ecSMike Barcroft * notice, this list of conditions and the following disclaimer in the 11bd06a3ecSMike Barcroft * documentation and/or other materials provided with the distribution. 12bd06a3ecSMike Barcroft * 3. Berkeley Software Design Inc's name may not be used to endorse or 13bd06a3ecSMike Barcroft * promote products derived from this software without specific prior 14bd06a3ecSMike Barcroft * written permission. 15bd06a3ecSMike Barcroft * 16bd06a3ecSMike Barcroft * THIS SOFTWARE IS PROVIDED BY BERKELEY SOFTWARE DESIGN INC ``AS IS'' AND 17bd06a3ecSMike Barcroft * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18bd06a3ecSMike Barcroft * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19bd06a3ecSMike Barcroft * ARE DISCLAIMED. IN NO EVENT SHALL BERKELEY SOFTWARE DESIGN INC BE LIABLE 20bd06a3ecSMike Barcroft * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21bd06a3ecSMike Barcroft * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22bd06a3ecSMike Barcroft * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23bd06a3ecSMike Barcroft * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24bd06a3ecSMike Barcroft * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25bd06a3ecSMike Barcroft * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26bd06a3ecSMike Barcroft * SUCH DAMAGE. 27bd06a3ecSMike Barcroft * 28bd06a3ecSMike Barcroft * From BSDI: daemon.c,v 1.2 1996/08/15 01:11:09 jch Exp 29bd06a3ecSMike Barcroft */ 30bd06a3ecSMike Barcroft 3154ede02dSPhilippe Charnier #include <sys/cdefs.h> 3254ede02dSPhilippe Charnier __FBSDID("$FreeBSD$"); 3354ede02dSPhilippe Charnier 34c6262cb6SPawel Jakub Dawidek #include <sys/param.h> 3553c49998SMikolaj Golub #include <sys/mman.h> 362ad43027SMikolaj Golub #include <sys/wait.h> 37bd06a3ecSMike Barcroft 38bd06a3ecSMike Barcroft #include <err.h> 39846be7bdSPoul-Henning Kamp #include <errno.h> 40c6262cb6SPawel Jakub Dawidek #include <libutil.h> 41e6d4b388STom Rhodes #include <login_cap.h> 42195fc497SMikolaj Golub #include <pwd.h> 43195fc497SMikolaj Golub #include <signal.h> 44bd06a3ecSMike Barcroft #include <stdio.h> 45bd06a3ecSMike Barcroft #include <stdlib.h> 46bd06a3ecSMike Barcroft #include <unistd.h> 47bd06a3ecSMike Barcroft 48195fc497SMikolaj Golub static void dummy_sighandler(int); 49e6d4b388STom Rhodes static void restrict_process(const char *); 50b6193c24SMikolaj Golub static int wait_child(pid_t pid, sigset_t *mask); 51bd06a3ecSMike Barcroft static void usage(void); 52bd06a3ecSMike Barcroft 53bd06a3ecSMike Barcroft int 54bd06a3ecSMike Barcroft main(int argc, char *argv[]) 55bd06a3ecSMike Barcroft { 5615543aadSTom Rhodes struct pidfh *pfh = NULL; 57195fc497SMikolaj Golub sigset_t mask, oldmask; 58b6193c24SMikolaj Golub int ch, nochdir, noclose, restart; 59e6d4b388STom Rhodes const char *pidfile, *user; 602ad43027SMikolaj Golub pid_t otherpid, pid; 61bd06a3ecSMike Barcroft 62bd06a3ecSMike Barcroft nochdir = noclose = 1; 63b6193c24SMikolaj Golub restart = 0; 64e6d4b388STom Rhodes pidfile = user = NULL; 65b6193c24SMikolaj Golub while ((ch = getopt(argc, argv, "-cfp:ru:")) != -1) { 66bd06a3ecSMike Barcroft switch (ch) { 67bd06a3ecSMike Barcroft case 'c': 68bd06a3ecSMike Barcroft nochdir = 0; 69bd06a3ecSMike Barcroft break; 70bd06a3ecSMike Barcroft case 'f': 71bd06a3ecSMike Barcroft noclose = 0; 72bd06a3ecSMike Barcroft break; 73846be7bdSPoul-Henning Kamp case 'p': 74846be7bdSPoul-Henning Kamp pidfile = optarg; 75846be7bdSPoul-Henning Kamp break; 76b6193c24SMikolaj Golub case 'r': 77b6193c24SMikolaj Golub restart = 1; 78b6193c24SMikolaj Golub break; 79e6d4b388STom Rhodes case 'u': 80e6d4b388STom Rhodes user = optarg; 81e6d4b388STom Rhodes break; 82bd06a3ecSMike Barcroft default: 83bd06a3ecSMike Barcroft usage(); 84bd06a3ecSMike Barcroft } 85bd06a3ecSMike Barcroft } 86bd06a3ecSMike Barcroft argc -= optind; 87bd06a3ecSMike Barcroft argv += optind; 88bd06a3ecSMike Barcroft 89bd06a3ecSMike Barcroft if (argc == 0) 90bd06a3ecSMike Barcroft usage(); 9112d7249eSTom Rhodes 922ad43027SMikolaj Golub pfh = NULL; 93846be7bdSPoul-Henning Kamp /* 94846be7bdSPoul-Henning Kamp * Try to open the pidfile before calling daemon(3), 95846be7bdSPoul-Henning Kamp * to be able to report the error intelligently 96846be7bdSPoul-Henning Kamp */ 972ad43027SMikolaj Golub if (pidfile != NULL) { 98c6262cb6SPawel Jakub Dawidek pfh = pidfile_open(pidfile, 0600, &otherpid); 99c6262cb6SPawel Jakub Dawidek if (pfh == NULL) { 100c6262cb6SPawel Jakub Dawidek if (errno == EEXIST) { 101c6262cb6SPawel Jakub Dawidek errx(3, "process already running, pid: %d", 102c6262cb6SPawel Jakub Dawidek otherpid); 103c6262cb6SPawel Jakub Dawidek } 104846be7bdSPoul-Henning Kamp err(2, "pidfile ``%s''", pidfile); 105846be7bdSPoul-Henning Kamp } 106c6262cb6SPawel Jakub Dawidek } 107846be7bdSPoul-Henning Kamp 108bd06a3ecSMike Barcroft if (daemon(nochdir, noclose) == -1) 109bd06a3ecSMike Barcroft err(1, NULL); 110846be7bdSPoul-Henning Kamp 111195fc497SMikolaj Golub /* 112b6193c24SMikolaj Golub * If the pidfile or restart option is specified the daemon 113b6193c24SMikolaj Golub * executes the command in a forked process and wait on child 114b6193c24SMikolaj Golub * exit to remove the pidfile or restart the command. Normally 115b6193c24SMikolaj Golub * we don't want the monitoring daemon to be terminated 116b6193c24SMikolaj Golub * leaving the running process and the stale pidfile, so we 117b6193c24SMikolaj Golub * catch SIGTERM and forward it to the children expecting to 118b6193c24SMikolaj Golub * get SIGCHLD eventually. 119195fc497SMikolaj Golub */ 120195fc497SMikolaj Golub pid = -1; 121b6193c24SMikolaj Golub if (pidfile != NULL || restart) { 1222ad43027SMikolaj Golub /* 123195fc497SMikolaj Golub * Restore default action for SIGTERM in case the 124195fc497SMikolaj Golub * parent process decided to ignore it. 125195fc497SMikolaj Golub */ 126195fc497SMikolaj Golub if (signal(SIGTERM, SIG_DFL) == SIG_ERR) 127195fc497SMikolaj Golub err(1, "signal"); 128195fc497SMikolaj Golub /* 129195fc497SMikolaj Golub * Because SIGCHLD is ignored by default, setup dummy handler 130195fc497SMikolaj Golub * for it, so we can mask it. 131195fc497SMikolaj Golub */ 132195fc497SMikolaj Golub if (signal(SIGCHLD, dummy_sighandler) == SIG_ERR) 133195fc497SMikolaj Golub err(1, "signal"); 134195fc497SMikolaj Golub /* 135195fc497SMikolaj Golub * Block interesting signals. 136195fc497SMikolaj Golub */ 137195fc497SMikolaj Golub sigemptyset(&mask); 138195fc497SMikolaj Golub sigaddset(&mask, SIGTERM); 139195fc497SMikolaj Golub sigaddset(&mask, SIGCHLD); 140195fc497SMikolaj Golub if (sigprocmask(SIG_SETMASK, &mask, &oldmask) == -1) 141195fc497SMikolaj Golub err(1, "sigprocmask"); 14253c49998SMikolaj Golub /* 14353c49998SMikolaj Golub * Try to protect against pageout kill. Ignore the 14453c49998SMikolaj Golub * error, madvise(2) will fail only if a process does 14553c49998SMikolaj Golub * not have superuser privileges. 14653c49998SMikolaj Golub */ 14753c49998SMikolaj Golub (void)madvise(NULL, 0, MADV_PROTECT); 148b6193c24SMikolaj Golub restart: 149195fc497SMikolaj Golub /* 1502ad43027SMikolaj Golub * Spawn a child to exec the command, so in the parent 1512ad43027SMikolaj Golub * we could wait for it to exit and remove pidfile. 1522ad43027SMikolaj Golub */ 1532ad43027SMikolaj Golub pid = fork(); 1542ad43027SMikolaj Golub if (pid == -1) { 1552ad43027SMikolaj Golub pidfile_remove(pfh); 1562ad43027SMikolaj Golub err(1, "fork"); 1572ad43027SMikolaj Golub } 1582ad43027SMikolaj Golub } 159195fc497SMikolaj Golub if (pid <= 0) { 1602ad43027SMikolaj Golub if (pid == 0) { 161195fc497SMikolaj Golub /* Restore old sigmask in the child. */ 162195fc497SMikolaj Golub if (sigprocmask(SIG_SETMASK, &oldmask, NULL) == -1) 163195fc497SMikolaj Golub err(1, "sigprocmask"); 164195fc497SMikolaj Golub } 1652ad43027SMikolaj Golub /* Now that we are the child, write out the pid. */ 166c6262cb6SPawel Jakub Dawidek pidfile_write(pfh); 167846be7bdSPoul-Henning Kamp 1682ad43027SMikolaj Golub if (user != NULL) 1692ad43027SMikolaj Golub restrict_process(user); 1702ad43027SMikolaj Golub 171bd06a3ecSMike Barcroft execvp(argv[0], argv); 172bd06a3ecSMike Barcroft 173846be7bdSPoul-Henning Kamp /* 1742ad43027SMikolaj Golub * execvp() failed -- report the error. The child is 1752ad43027SMikolaj Golub * now running, so the exit status doesn't matter. 176846be7bdSPoul-Henning Kamp */ 1772ad43027SMikolaj Golub err(1, "%s", argv[0]); 1782ad43027SMikolaj Golub } 1792ad43027SMikolaj Golub setproctitle("%s[%d]", argv[0], pid); 180b6193c24SMikolaj Golub if (wait_child(pid, &mask) == 0 && restart) { 181b6193c24SMikolaj Golub sleep(1); 182b6193c24SMikolaj Golub goto restart; 183b6193c24SMikolaj Golub } 184c6262cb6SPawel Jakub Dawidek pidfile_remove(pfh); 1852ad43027SMikolaj Golub exit(0); /* Exit status does not matter. */ 186bd06a3ecSMike Barcroft } 187bd06a3ecSMike Barcroft 188bd06a3ecSMike Barcroft static void 189195fc497SMikolaj Golub dummy_sighandler(int sig __unused) 190195fc497SMikolaj Golub { 191195fc497SMikolaj Golub /* Nothing to do. */ 192195fc497SMikolaj Golub } 193195fc497SMikolaj Golub 194195fc497SMikolaj Golub static void 195e6d4b388STom Rhodes restrict_process(const char *user) 19612d7249eSTom Rhodes { 19712d7249eSTom Rhodes struct passwd *pw = NULL; 19812d7249eSTom Rhodes 199e6d4b388STom Rhodes pw = getpwnam(user); 200e6d4b388STom Rhodes if (pw == NULL) 201e6d4b388STom Rhodes errx(1, "unknown user: %s", user); 20212d7249eSTom Rhodes 203e6d4b388STom Rhodes if (setusercontext(NULL, pw, pw->pw_uid, LOGIN_SETALL) != 0) 204e6d4b388STom Rhodes errx(1, "failed to set user environment"); 20512d7249eSTom Rhodes } 20612d7249eSTom Rhodes 207b6193c24SMikolaj Golub static int 208195fc497SMikolaj Golub wait_child(pid_t pid, sigset_t *mask) 2092ad43027SMikolaj Golub { 210b6193c24SMikolaj Golub int terminate, signo; 2112ad43027SMikolaj Golub 212b6193c24SMikolaj Golub terminate = 0; 213195fc497SMikolaj Golub for (;;) { 214195fc497SMikolaj Golub if (sigwait(mask, &signo) == -1) { 215195fc497SMikolaj Golub warn("sigwaitinfo"); 216b6193c24SMikolaj Golub return (-1); 217195fc497SMikolaj Golub } 218195fc497SMikolaj Golub switch (signo) { 219195fc497SMikolaj Golub case SIGCHLD: 220*c60d51f9SMikolaj Golub if (waitpid(pid, NULL, WNOHANG) == -1) { 221*c60d51f9SMikolaj Golub warn("waitpid"); 222*c60d51f9SMikolaj Golub return (-1); 223*c60d51f9SMikolaj Golub } 224b6193c24SMikolaj Golub return (terminate); 225195fc497SMikolaj Golub case SIGTERM: 226b6193c24SMikolaj Golub terminate = 1; 227195fc497SMikolaj Golub if (kill(pid, signo) == -1) { 228195fc497SMikolaj Golub warn("kill"); 229b6193c24SMikolaj Golub return (-1); 230195fc497SMikolaj Golub } 231195fc497SMikolaj Golub continue; 232195fc497SMikolaj Golub default: 233195fc497SMikolaj Golub warnx("sigwaitinfo: invalid signal: %d", signo); 234b6193c24SMikolaj Golub return (-1); 2352ad43027SMikolaj Golub } 2362ad43027SMikolaj Golub } 2372ad43027SMikolaj Golub } 2382ad43027SMikolaj Golub 2392ad43027SMikolaj Golub static void 240bd06a3ecSMike Barcroft usage(void) 241bd06a3ecSMike Barcroft { 242846be7bdSPoul-Henning Kamp (void)fprintf(stderr, 243e6d4b388STom Rhodes "usage: daemon [-cf] [-p pidfile] [-u user] command " 24412d7249eSTom Rhodes "arguments ...\n"); 245bd06a3ecSMike Barcroft exit(1); 246bd06a3ecSMike Barcroft } 247