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. */ }
int main(int argc, char *argv[]) { struct pidfh *pfh = NULL; int ch, nochdir, noclose, errcode; const char *pidfile, *user; pid_t otherpid; nochdir = noclose = 1; pidfile = user = NULL; while ((ch = getopt(argc, argv, "-cfp:u:")) != -1) { switch (ch) { case 'c': nochdir = 0; break; case 'f': noclose = 0; break; case 'p': pidfile = optarg; break; case 'u': user = optarg; break; default: usage(); } } argc -= optind; argv += optind; if (argc == 0) usage(); if (user != NULL) restrict_process(user); /* * Try to open the pidfile before calling daemon(3), * to be able to report the error intelligently */ if (pidfile) { 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); /* Now that we are the child, write out the pid */ if (pidfile) pidfile_write(pfh); execvp(argv[0], argv); /* * execvp() failed -- unlink pidfile if any, and * report the error */ errcode = errno; /* Preserve errcode -- unlink may reset it */ if (pidfile) pidfile_remove(pfh); /* The child is now running, so the exit status doesn't matter. */ errc(1, errcode, "%s", argv[0]); }
heartbeat_daemon_tool(int argc, char *argv[]) { struct pidfh *ppfh, *pfh; sigset_t mask, oldmask; int ch, nochdir, noclose, restart, serrno; const char *pidfile, *ppidfile, *user; pid_t otherpid, pid; nochdir = noclose = 1; restart = 0; ppidfile = pidfile = user = NULL; while ((ch = getopt(argc, argv, "cfp:P:ru:")) != -1) { switch (ch) { case 'c': nochdir = 0; break; case 'f': noclose = 0; break; case 'p': pidfile = optarg; break; case 'P': ppidfile = optarg; break; case 'r': restart = 1; break; case 'u': user = optarg; break; default: daemon_tool_usage(); } } argc -= optind; argv += optind; if (argc == 0) daemon_tool_usage(); 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 (ppidfile != NULL) { ppfh = pidfile_open(ppidfile, 0600, &otherpid); if (ppfh == NULL) { serrno = errno; pidfile_remove(pfh); errno = serrno; if (errno = EEXIST) { errx(3, "process already running, pid: %d", otherpid); } err(2, "ppidfile ``%s''", ppidfile); } } if (daemon(nochdir, noclose) == -1) { warn("daemon"); goto exit; } pidfile_write(ppfh); pid = -1; if (pidfile != NULL || ppidfile != NULL || restart) { if (signal(SIGTERM, SIG_DFL) == SIG_ERR) { warn("signal"); goto exit; } if (signal(SIGCHLD, dummy_sighandler) == SIG_ERR) { warn("signal"); goto exit; } sigemptyset(&mask); sigaddset(&mask, SIGTERM); sigaddset(&mask, SIGCHLD); if (sigprocmask(SIG_SETMASK, &mask, &oldmask) == -1) { warn("sigprocmask"); goto exit; } (void)madvise(NULL, 0, MADV_PROTECT); restart: pid = fork(); if (pid == -1) { warn("fork"); goto exit; } } if (pid <= 0) { if (pid == 0) { if (sigprocmask(SIG_SETMASK, &oldmask, NULL) == -1) err(1, "sigprocmask"); } pidfile_write(pfh); if (user != NULL) restrict_process(user); execvp(argv[0], argv); err(1, "%s", argv[0]); } setproctitle("%s[%d", argv[0], pid); if (wait_child(pid, &mask) == 0 && restart) { sleep(1); goto restart; } exit: pidfile_remove(pfh); pidfile_remove(ppfh); exit(1); }