path: root/src/rc/supervise-daemon.c

/*
 * supervise-daemon
 * This is an experimental supervisor for daemons.
 * It will start a deamon and make sure it restarts if it crashes.
 */

/*
 * Copyright (c) 2016 The OpenRC Authors.
 * See the Authors file at the top-level directory of this distribution and
 * https://github.com/OpenRC/openrc/blob/master/AUTHORS
 *
 * This file is part of OpenRC. It is subject to the license terms in
 * the LICENSE file found in the top-level directory of this
 * distribution and at https://github.com/OpenRC/openrc/blob/master/LICENSE
 * This file may not be copied, modified, propagated, or distributed
 *    except according to the terms contained in the LICENSE file.
 */

/* nano seconds */
#define POLL_INTERVAL   20000000
#define WAIT_PIDFILE   500000000
#define ONE_SECOND    1000000000
#define ONE_MS           1000000

#include <sys/types.h>
#include <sys/ioctl.h>
#include <sys/resource.h>
#include <sys/stat.h>
#include <termios.h>
#include <sys/time.h>
#include <sys/wait.h>

#ifdef __linux__
#include <sys/syscall.h> /* For io priority */
#endif

#include <ctype.h>
#include <errno.h>
#include <fcntl.h>
#include <getopt.h>
#include <limits.h>
#include <grp.h>
#include <pwd.h>
#include <signal.h>
#include <stddef.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <syslog.h>
#include <time.h>
#include <unistd.h>

#ifdef HAVE_PAM
#include <security/pam_appl.h>

/* We are not supporting authentication conversations */
static struct pam_conv conv = { NULL, NULL};
#endif

#include "einfo.h"
#include "queue.h"
#include "rc.h"
#include "rc-misc.h"
#include "rc-schedules.h"
#include "_usage.h"
#include "helpers.h"

const char *applet = NULL;
const char *extraopts = NULL;
const char *getoptstring = "D:d:e:g:I:Kk:m:N:p:R:r:Su:1:2:3" \
	getoptstring_COMMON;
const struct option longopts[] = {
	{ "respawn-delay",        1, NULL, 'D'},
	{ "chdir",        1, NULL, 'd'},
	{ "env",          1, NULL, 'e'},
	{ "group",        1, NULL, 'g'},
	{ "ionice",       1, NULL, 'I'},
	{ "stop",         0, NULL, 'K'},
	{ "umask",        1, NULL, 'k'},
	{ "respawn-max",    1, NULL, 'm'},
	{ "nicelevel",    1, NULL, 'N'},
	{ "pidfile",      1, NULL, 'p'},
	{ "respawn-period",        1, NULL, 'P'},
	{ "retry",       1, NULL, 'R'},
	{ "chroot",       1, NULL, 'r'},
	{ "start",        0, NULL, 'S'},
	{ "user",         1, NULL, 'u'},
	{ "stdout",       1, NULL, '1'},
	{ "stderr",       1, NULL, '2'},
	{ "reexec",       0, NULL, '3'},
	longopts_COMMON
};
const char * const longopts_help[] = {
	"Set a respawn delay",
	"Change the PWD",
	"Set an environment string",
	"Change the process group",
	"Set an ionice class:data when starting",
	"Stop daemon",
	"Set the umask for the daemon",
	"set maximum number of respawn attempts",
	"Set a nicelevel when starting",
	"Match pid found in this file",
	"Set respawn time period",
	"Retry schedule to use when stopping",
	"Chroot to this directory",
	"Start daemon",
	"Change the process user",
	"Redirect stdout to file",
	"Redirect stderr to file",
	"reexec (used internally)",
	longopts_help_COMMON
};
const char *usagestring = NULL;

static int nicelevel = 0;
static int ionicec = -1;
static int ioniced = 0;
static char *changeuser, *ch_root, *ch_dir;
static uid_t uid = 0;
static gid_t gid = 0;
static int devnull_fd = -1;
static int stdin_fd;
static int stdout_fd;
static int stderr_fd;
static char *redirect_stderr = NULL;
static char *redirect_stdout = NULL;
static bool exiting = false;
#ifdef TIOCNOTTY
static int tty_fd = -1;
#endif
static pid_t child_pid;
static int respawn_count = 0;
static int respawn_delay = 0;
static int respawn_max = 10;
static int respawn_period = 5;
static char *pidfile = NULL;
static char *svcname = NULL;

extern char **environ;

#if !defined(SYS_ioprio_set) && defined(__NR_ioprio_set)
# define SYS_ioprio_set __NR_ioprio_set
#endif
#if !defined(__DragonFly__)
static inline int ioprio_set(int which _unused, int who _unused,
			     int ioprio _unused)
{
#ifdef SYS_ioprio_set
	return syscall(SYS_ioprio_set, which, who, ioprio);
#else
	return 0;
#endif
}
#endif

static void cleanup(void)
{
	free(changeuser);
}

static void re_exec_supervisor(void)
{
	syslog(LOG_WARNING, "Re-executing for %s", svcname);
	execlp("supervise-daemon", "supervise-daemon", svcname, "--reexec",
			(char *) NULL);
	syslog(LOG_ERR, "Unable to execute supervise-daemon: %s",
			strerror(errno));
	exit(EXIT_FAILURE);
}

static void handle_signal(int sig)
{
	int serrno = errno;

	syslog(LOG_WARNING, "caught signal %d", sig);

	if (sig == SIGTERM)
		exiting = true;
	/* Restore errno */
	errno = serrno;
	if (! exiting)
		re_exec_supervisor();
}

static char * expand_home(const char *home, const char *path)
{
	char *opath, *ppath, *p, *nh;
	size_t len;
	struct passwd *pw;

	if (!path || *path != '~')
		return xstrdup(path);

	opath = ppath = xstrdup(path);
	if (ppath[1] != '/' && ppath[1] != '\0') {
		p = strchr(ppath + 1, '/');
		if (p)
			*p = '\0';
		pw = getpwnam(ppath + 1);
		if (pw) {
			home = pw->pw_dir;
			ppath = p;
			if (ppath)
				*ppath = '/';
		} else
			home = NULL;
	} else
		ppath++;

	if (!home) {
	free(opath);
		return xstrdup(path);
	}
	if (!ppath) {
		free(opath);
		return xstrdup(home);
	}

	len = strlen(ppath) + strlen(home) + 1;
	nh = xmalloc(len);
	snprintf(nh, len, "%s%s", home, ppath);
	free(opath);
	return nh;
}

static char *make_cmdline(char **argv)
{
	char **c;
	char *cmdline = NULL;
	size_t len = 0;

	for (c = argv; c && *c; c++)
		len += (strlen(*c) + 1);
	cmdline = xmalloc(len+1);
	memset(cmdline, 0, len+1);
	for (c = argv; c && *c; c++) {
		strcat(cmdline, *c);
		strcat(cmdline, " ");
	}
	return cmdline;
}

static void child_process(char *exec, char **argv)
{
	RC_STRINGLIST *env_list;
	RC_STRING *env;
	int i;
	char *p;
	char *token;
	size_t len;
	char *newpath;
	char *np;
	char *cmdline = NULL;
	time_t start_time;
	char start_count_string[20];
	char start_time_string[20];

#ifdef HAVE_PAM
	pam_handle_t *pamh = NULL;
	int pamr;
	const char *const *pamenv = NULL;
#endif

	setsid();

	if (svcname) {
		start_time = time(NULL);
		from_time_t(start_time_string, start_time);
		rc_service_value_set(svcname, "start_time", start_time_string);
		sprintf(start_count_string, "%i", respawn_count);
		rc_service_value_set(svcname, "start_count", start_count_string);
		sprintf(start_count_string, "%d", getpid());
		rc_service_value_set(svcname, "child_pid", start_count_string);
	}

	if (nicelevel) {
		if (setpriority(PRIO_PROCESS, getpid(), nicelevel) == -1)
			eerrorx("%s: setpriority %d: %s", applet, nicelevel,
					strerror(errno));
	}

	if (ionicec != -1 && ioprio_set(1, getpid(), ionicec | ioniced) == -1)
		eerrorx("%s: ioprio_set %d %d: %s", applet, ionicec, ioniced,
				strerror(errno));

	if (ch_root && chroot(ch_root) < 0)
		eerrorx("%s: chroot `%s': %s", applet, ch_root, strerror(errno));

	if (ch_dir && chdir(ch_dir) < 0)
		eerrorx("%s: chdir `%s': %s", applet, ch_dir, strerror(errno));

#ifdef HAVE_PAM
	if (changeuser != NULL) {
		pamr = pam_start("supervise-daemon",
		    changeuser, &conv, &pamh);

		if (pamr == PAM_SUCCESS)
			pamr = pam_acct_mgmt(pamh, PAM_SILENT);
		if (pamr == PAM_SUCCESS)
			pamr = pam_open_session(pamh, PAM_SILENT);
		if (pamr != PAM_SUCCESS)
			eerrorx("%s: pam error: %s", applet, pam_strerror(pamh, pamr));
	}
#endif

	if (gid && setgid(gid))
		eerrorx("%s: unable to set groupid to %d", applet, gid);
	if (changeuser && initgroups(changeuser, gid))
		eerrorx("%s: initgroups (%s, %d)", applet, changeuser, gid);
	if (uid && setuid(uid))
		eerrorx ("%s: unable to set userid to %d", applet, uid);

	/* Close any fd's to the passwd database */
	endpwent();

	/* remove the controlling tty */
#ifdef TIOCNOTTY
	ioctl(tty_fd, TIOCNOTTY, 0);
	close(tty_fd);
#endif

	/* Clean the environment of any RC_ variables */
	env_list = rc_stringlist_new();
	i = 0;
	while (environ[i])
		rc_stringlist_add(env_list, environ[i++]);

#ifdef HAVE_PAM
	if (changeuser != NULL) {
		pamenv = (const char *const *)pam_getenvlist(pamh);
		if (pamenv) {
			while (*pamenv) {
				/* Don't add strings unless they set a var */
				if (strchr(*pamenv, '='))
					putenv(xstrdup(*pamenv));
				else
					unsetenv(*pamenv);
				pamenv++;
			}
		}
	}
#endif

	TAILQ_FOREACH(env, env_list, entries) {
		if ((strncmp(env->value, "RC_", 3) == 0 &&
			strncmp(env->value, "RC_SERVICE=", 10) != 0 &&
			strncmp(env->value, "RC_SVCNAME=", 10) != 0) ||
		    strncmp(env->value, "SSD_NICELEVEL=", 14) == 0)
		{
			p = strchr(env->value, '=');
			*p = '\0';
			unsetenv(env->value);
			continue;
		}
	}
	rc_stringlist_free(env_list);

	/* For the path, remove the rcscript bin dir from it */
	if ((token = getenv("PATH"))) {
		len = strlen(token);
		newpath = np = xmalloc(len + 1);
		while (token && *token) {
			p = strchr(token, ':');
			if (p) {
				*p++ = '\0';
				while (*p == ':')
					p++;
			}
			if (strcmp(token, RC_LIBEXECDIR "/bin") != 0 &&
			    strcmp(token, RC_LIBEXECDIR "/sbin") != 0)
			{
				len = strlen(token);
				if (np != newpath)
					*np++ = ':';
				memcpy(np, token, len);
				np += len;
				}
			token = p;
		}
		*np = '\0';
		unsetenv("PATH");
		setenv("PATH", newpath, 1);
	}

	stdin_fd = devnull_fd;
	stdout_fd = devnull_fd;
	stderr_fd = devnull_fd;
	if (redirect_stdout) {
		if ((stdout_fd = open(redirect_stdout,
			    O_WRONLY | O_CREAT | O_APPEND,
			    S_IRUSR | S_IWUSR)) == -1)
			eerrorx("%s: unable to open the logfile"
				    " for stdout `%s': %s",
				    applet, redirect_stdout, strerror(errno));
	}
	if (redirect_stderr) {
		if ((stderr_fd = open(redirect_stderr,
			    O_WRONLY | O_CREAT | O_APPEND,
			    S_IRUSR | S_IWUSR)) == -1)
			eerrorx("%s: unable to open the logfile"
			    " for stderr `%s': %s",
			    applet, redirect_stderr, strerror(errno));
	}

	dup2(stdin_fd, STDIN_FILENO);
	if (redirect_stdout || rc_yesno(getenv("EINFO_QUIET")))
		dup2(stdout_fd, STDOUT_FILENO);
	if (redirect_stderr || rc_yesno(getenv("EINFO_QUIET")))
		dup2(stderr_fd, STDERR_FILENO);

	for (i = getdtablesize() - 1; i >= 3; --i)
		fcntl(i, F_SETFD, FD_CLOEXEC);
	cmdline = make_cmdline(argv);
	syslog(LOG_INFO, "Child command line: %s", cmdline);
	free(cmdline);
	execvp(exec, argv);

#ifdef HAVE_PAM
	if (changeuser != NULL && pamr == PAM_SUCCESS)
		pam_close_session(pamh, PAM_SILENT);
#endif
	eerrorx("%s: failed to exec `%s': %s", applet, exec,strerror(errno));
}

static void supervisor(char *exec, char **argv)
{
	FILE *fp;
	int i;
	int nkilled;
	time_t respawn_now= 0;
	time_t first_spawn= 0;

#ifndef RC_DEBUG
	signal_setup_restart(SIGHUP, handle_signal);
	signal_setup_restart(SIGINT, handle_signal);
	signal_setup_restart(SIGQUIT, handle_signal);
	signal_setup_restart(SIGILL, handle_signal);
	signal_setup_restart(SIGABRT, handle_signal);
	signal_setup_restart(SIGFPE, handle_signal);
	signal_setup_restart(SIGSEGV, handle_signal);
	signal_setup_restart(SIGPIPE, handle_signal);
	signal_setup_restart(SIGALRM, handle_signal);
	signal_setup(SIGTERM, handle_signal);
	signal_setup_restart(SIGUSR1, handle_signal);
	signal_setup_restart(SIGUSR2, handle_signal);
	signal_setup_restart(SIGBUS, handle_signal);
#ifdef SIGPOLL
	signal_setup_restart(SIGPOLL, handle_signal);
#endif
	signal_setup_restart(SIGPROF, handle_signal);
	signal_setup_restart(SIGSYS, handle_signal);
	signal_setup_restart(SIGTRAP, handle_signal);
	signal_setup_restart(SIGVTALRM, handle_signal);
	signal_setup_restart(SIGXCPU, handle_signal);
	signal_setup_restart(SIGXFSZ, handle_signal);
#ifdef SIGEMT
	signal_setup_restart(SIGEMT, handle_signal);
#endif
	signal_setup_restart(SIGIO, handle_signal);
#ifdef SIGPWR
	signal_setup_restart(SIGPWR, handle_signal);
#endif
#ifdef SIGUNUSED
	signal_setup_restart(SIGUNUSED, handle_signal);
#endif
#ifdef SIGRTMIN
	for (i = SIGRTMIN; i <= SIGRTMAX; i++)
		signal_setup_restart(i, handle_signal);
#endif
#endif

	fp = fopen(pidfile, "w");
	if (! fp)
		eerrorx("%s: fopen `%s': %s", applet, pidfile, strerror(errno));
	fprintf(fp, "%d\n", getpid());
	fclose(fp);

	if (svcname)
		rc_service_daemon_set(svcname, exec, (const char * const *) argv,
				pidfile, true);

	/* remove the controlling tty */
#ifdef TIOCNOTTY
	ioctl(tty_fd, TIOCNOTTY, 0);
	close(tty_fd);
#endif

	/*
	 * Supervisor main loop
	 */
	i = 0;
	while (!exiting) {
		wait(&i);
		if (exiting) {
			signal_setup(SIGCHLD, SIG_IGN);
			syslog(LOG_INFO, "stopping %s, pid %d", exec, child_pid);
			nkilled = run_stop_schedule(applet, exec, NULL, child_pid, 0,
					false, false, true);
			if (nkilled > 0)
				syslog(LOG_INFO, "killed %d processes", nkilled);
		} else {
			sleep(respawn_delay);
			if (respawn_max > 0 && respawn_period > 0) {
				respawn_now = time(NULL);
				if (first_spawn == 0)
					first_spawn = respawn_now;
				if (respawn_now - first_spawn > respawn_period) {
					respawn_count = 0;
					first_spawn = 0;
				} else
					respawn_count++;
				if (respawn_count >= respawn_max) {
					syslog(LOG_WARNING,
							"respawned \"%s\" too many times, exiting", exec);
					exiting = true;
					continue;
				}
			}
			if (WIFEXITED(i))
				syslog(LOG_WARNING, "%s, pid %d, exited with return code %d",
						exec, child_pid, WEXITSTATUS(i));
			else if (WIFSIGNALED(i))
				syslog(LOG_WARNING, "%s, pid %d, terminated by signal %d",
						exec, child_pid, WTERMSIG(i));
			child_pid = fork();
			if (child_pid == -1)
				eerrorx("%s: fork: %s", applet, strerror(errno));
			if (child_pid == 0)
				child_process(exec, argv);
		}
	}

	if (pidfile && exists(pidfile))
		unlink(pidfile);
	if (svcname) {
		rc_service_daemon_set(svcname, exec, (const char *const *)argv,
				pidfile, false);
		rc_service_mark(svcname, RC_SERVICE_STOPPED);
		rc_service_value_set(svcname, "child_pid", NULL);
	}
	exit(EXIT_SUCCESS);
}

int main(int argc, char **argv)
{
	int opt;
	char **c;
	int x;
	bool start = false;
	bool stop = false;
	bool reexec = false;
	char *exec = NULL;
	char *retry = NULL;
	int sig = SIGTERM;
	char *home = NULL;
	int tid = 0;
	pid_t pid;
	char *tmp;
	char *p;
	char *token;
	int i;
	int n;
	char *exec_file = NULL;
	char *varbuf = NULL;
	struct timespec ts;
	struct passwd *pw;
	struct group *gr;
	FILE *fp;
	mode_t numask = 022;
	int child_argc = 0;
	char **child_argv = NULL;
	char *str = NULL;
	char *cmdline = NULL;

	applet = basename_c(argv[0]);
	atexit(cleanup);
	svcname = getenv("RC_SVCNAME");
	if (!svcname)
		eerrorx("%s: The RC_SVCNAME environment variable is not set", applet);
	openlog(applet, LOG_PID, LOG_DAEMON);

	if (argc >= 1 && svcname && strcmp(argv[1], svcname))
		eerrorx("%s: the first argument is %s and must be %s",
				applet, argv[1], svcname);

	if ((tmp = getenv("SSD_NICELEVEL")))
		if (sscanf(tmp, "%d", &nicelevel) != 1)
			eerror("%s: invalid nice level `%s' (SSD_NICELEVEL)",
			    applet, tmp);

	/* Get our user name and initial dir */
	p = getenv("USER");
	home = getenv("HOME");
	if (home == NULL || p == NULL) {
		pw = getpwuid(getuid());
		if (pw != NULL) {
			if (p == NULL)
				setenv("USER", pw->pw_name, 1);
			if (home == NULL) {
				setenv("HOME", pw->pw_dir, 1);
				home = pw->pw_dir;
			}
		}
	}

	cmdline = make_cmdline(argv);
	if (svcname) {
		argc--;
		argv++;
	}
	while ((opt = getopt_long(argc, argv, getoptstring, longopts,
		    (int *) 0)) != -1)
		switch (opt) {
		case 'D':  /* --respawn-delay time */
			n = sscanf(optarg, "%d", &respawn_delay);
			if (n	!= 1 || respawn_delay < 1)
				eerrorx("Invalid respawn-delay value '%s'", optarg);
			break;

		case 'I': /* --ionice */
			if (sscanf(optarg, "%d:%d", &ionicec, &ioniced) == 0)
				eerrorx("%s: invalid ionice `%s'",
				    applet, optarg);
			if (ionicec == 0)
				ioniced = 0;
			else if (ionicec == 3)
				ioniced = 7;
			ionicec <<= 13; /* class shift */
			break;

		case 'K':  /* --stop */
			stop = true;
			break;

		case 'N':  /* --nice */
			if (sscanf(optarg, "%d", &nicelevel) != 1)
				eerrorx("%s: invalid nice level `%s'",
				    applet, optarg);
			break;

		case 'P':  /* --respawn-period time */
			n = sscanf(optarg, "%d", &respawn_period);
			if (n	!= 1 || respawn_period < 1)
				eerrorx("Invalid respawn-period value '%s'", optarg);
			break;

		case 'S':  /* --start */
			start = true;
			break;

		case 'd':  /* --chdir /new/dir */
			ch_dir = optarg;
			break;

		case 'e': /* --env */
			putenv(optarg);
			break;

		case 'g':  /* --group <group>|<gid> */
			if (sscanf(optarg, "%d", &tid) != 1)
				gr = getgrnam(optarg);
			else
				gr = getgrgid((gid_t)tid);
			if (gr == NULL)
				eerrorx("%s: group `%s' not found",
				    applet, optarg);
			gid = gr->gr_gid;
			break;

		case 'k':
			if (parse_mode(&numask, optarg))
				eerrorx("%s: invalid mode `%s'",
				    applet, optarg);
			break;

		case 'm':  /* --respawn-max count */
			n = sscanf(optarg, "%d", &respawn_max);
			if (n	!= 1 || respawn_max < 1)
				eerrorx("Invalid respawn-max value '%s'", optarg);
			break;

		case 'p':  /* --pidfile <pid-file> */
			pidfile = optarg;
			break;

		case 'R':  /* --retry <schedule>|timeout */
			retry = optarg;
			break;
		case 'r':  /* --chroot /new/root */
			ch_root = optarg;
			break;

		case 'u':  /* --user <username>|<uid> */
		{
			p = optarg;
			tmp = strsep(&p, ":");
			changeuser = xstrdup(tmp);
			if (sscanf(tmp, "%d", &tid) != 1)
				pw = getpwnam(tmp);
			else
				pw = getpwuid((uid_t)tid);

			if (pw == NULL)
				eerrorx("%s: user `%s' not found",
				    applet, tmp);
			uid = pw->pw_uid;
			home = pw->pw_dir;
			unsetenv("HOME");
			if (pw->pw_dir)
				setenv("HOME", pw->pw_dir, 1);
			unsetenv("USER");
			if (pw->pw_name)
				setenv("USER", pw->pw_name, 1);
			if (gid == 0)
				gid = pw->pw_gid;

			if (p) {
				tmp = strsep (&p, ":");
				if (sscanf(tmp, "%d", &tid) != 1)
					gr = getgrnam(tmp);
				else
					gr = getgrgid((gid_t) tid);

				if (gr == NULL)
					eerrorx("%s: group `%s'"
					    " not found",
					    applet, tmp);
				gid = gr->gr_gid;
			}
		}
		break;

		case '1':   /* --stdout /path/to/stdout.lgfile */
			redirect_stdout = optarg;
			break;

		case '2':  /* --stderr /path/to/stderr.logfile */
			redirect_stderr = optarg;
			break;
		case '3':  /* --reexec */
			reexec = true;
			break;

		case_RC_COMMON_GETOPT
		}

	if (!pidfile && !reexec)
		eerrorx("%s: --pidfile must be specified", applet);
	endpwent();
	argc -= optind;
	argv += optind;
	exec = *argv;

	/* Expand ~ */
	if (ch_dir && *ch_dir == '~')
		ch_dir = expand_home(home, ch_dir);
	if (ch_root && *ch_root == '~')
		ch_root = expand_home(home, ch_root);

	umask(numask);

	if (reexec) {
		str = rc_service_value_get(svcname, "argc");
		sscanf(str, "%d", &child_argc);
		child_argv = xmalloc((child_argc + 1) * sizeof(char *));
		memset(child_argv, 0, (child_argc + 1) * sizeof(char *));
		for (x = 0; x < child_argc; x++) {
			xasprintf(&varbuf, "argv_%d", x);
			str = rc_service_value_get(svcname, varbuf);
			child_argv[x] = str;
			free(varbuf);
			varbuf = NULL;
		}
		free(str);
		str = rc_service_value_get(svcname, "child_pid");
		sscanf(str, "%d", &child_pid);
		free(str);
		exec = rc_service_value_get(svcname, "exec");
		pidfile = rc_service_value_get(svcname, "pidfile");
		retry = rc_service_value_get(svcname, "retry");
		if (retry) {
			parse_schedule(applet, retry, sig);
			rc_service_value_set(svcname, "retry", retry);
		} else
			parse_schedule(applet, NULL, sig);

		str = rc_service_value_get(svcname, "respawn_delay");
		sscanf(str, "%d", &respawn_delay);
		str = rc_service_value_get(svcname, "respawn_max");
		sscanf(str, "%d", &respawn_max);
		supervisor(exec, child_argv);
	} else if (start) {
		if (exec) {
			if (*exec == '~')
				exec = expand_home(home, exec);

			/* Validate that the binary exists if we are starting */
			if (*exec == '/' || *exec == '.') {
				/* Full or relative path */
				if (ch_root)
					xasprintf(&exec_file, "%s/%s", ch_root, exec);
				else
					xasprintf(&exec_file, "%s", exec);
			} else {
				/* Something in $PATH */
				p = tmp = xstrdup(getenv("PATH"));
				exec_file = NULL;
				while ((token = strsep(&p, ":"))) {
					if (ch_root)
						xasprintf(&exec_file, "%s/%s/%s", ch_root, token, exec);
					else
						xasprintf(&exec_file, "%s/%s", token, exec);
					if (exec_file && exists(exec_file))
						break;
					free(exec_file);
					exec_file = NULL;
				}
				free(tmp);
			}
			if (!exists(exec_file)) {
				eerror("%s: %s does not exist", applet,
				    *exec_file ? exec_file : exec);
				free(exec_file);
				exit(EXIT_FAILURE);
			}
		} else
			eerrorx("%s: nothing to start", applet);

		pid = get_pid(applet, pidfile);
		if (pid != -1)
			if (do_stop(applet, exec, (const char * const *)argv, pid, uid,
						0, false, true) > 0)
				eerrorx("%s: %s is already running", applet, exec);

		if (respawn_delay * respawn_max > respawn_period)
			ewarn("%s: Please increase the value of --respawn-period to more "
				"than %d to avoid infinite respawning", applet, 
				respawn_delay * respawn_max);

		if (retry) {
			parse_schedule(applet, retry, sig);
			rc_service_value_set(svcname, "retry", retry);
		} else
			parse_schedule(applet, NULL, sig);

		einfov("Detaching to start `%s'", exec);
		syslog(LOG_INFO, "Supervisor command line: %s", cmdline);
		free(cmdline);
		cmdline = NULL;

		/* Remove existing pidfile */
		if (pidfile)
			unlink(pidfile);

		/* Make sure we can write a pid file */
		fp = fopen(pidfile, "w");
		if (! fp)
			eerrorx("%s: fopen `%s': %s", applet, pidfile, strerror(errno));
		fclose(fp);

		rc_service_value_set(svcname, "pidfile", pidfile);
		varbuf = NULL;
		xasprintf(&varbuf, "%i", respawn_delay);
		rc_service_value_set(svcname, "respawn_delay", varbuf);
		xasprintf(&varbuf, "%i", respawn_max);
		rc_service_value_set(svcname, "respawn_max", varbuf);
		xasprintf(&varbuf, "%i", respawn_period);
		rc_service_value_set(svcname, "respawn_period", varbuf);
		child_pid = fork();
		if (child_pid == -1)
			eerrorx("%s: fork: %s", applet, strerror(errno));
		if (child_pid != 0)
			/* first parent process, do nothing. */
			exit(EXIT_SUCCESS);
#ifdef TIOCNOTTY
		tty_fd = open("/dev/tty", O_RDWR);
#endif
		devnull_fd = open("/dev/null", O_RDWR);
		child_pid = fork();
		if (child_pid == -1)
			eerrorx("%s: fork: %s", applet, strerror(errno));
		else if (child_pid != 0) {
			c = argv;
			x = 0;
			while (c && *c) {
				varbuf = NULL;
				xasprintf(&varbuf, "argv_%-d",x);
				rc_service_value_set(svcname, varbuf, *c);
				free(varbuf);
				varbuf = NULL;
				x++;
				c++;
			}
			xasprintf(&varbuf, "%d", x);
				rc_service_value_set(svcname, "argc", varbuf);
			rc_service_value_set(svcname, "exec", exec);
			supervisor(exec, argv);
		} else
			child_process(exec, argv);
	} else if (stop) {
		pid = get_pid(applet, pidfile);
		if (pid != -1) {
			i = kill(pid, SIGTERM);
			if (i != 0)
				/* We failed to send the signal */
				ewarn("Unable to shut down the supervisor");
			else {
				/* wait for the supervisor to go down */
				while (kill(pid, 0) == 0) {
					ts.tv_sec = 0;
					ts.tv_nsec = 1;
					nanosleep(&ts, NULL);
				}
			}
		}

		/* Even if we have not actually killed anything, we should
		 * remove information about it as it may have unexpectedly
		 * crashed out. We should also return success as the end
		 * result would be the same. */
		if (pidfile && exists(pidfile))
			unlink(pidfile);
		if (svcname) {
			rc_service_daemon_set(svcname, exec,
			    (const char *const *)argv,
			    pidfile, false);
			rc_service_mark(svcname, RC_SERVICE_STOPPED);
		}
		exit(EXIT_SUCCESS);
	}
}