debianutils/start_stop_daemon.c - busybox - Git at Google

 /* vi: set sw=4 ts=4: */
 /*
  * Mini start-stop-daemon implementation(s) for busybox
  *
  * Written by Marek Michalkiewicz <marekm@i17linuxb.ists.pwr.wroc.pl>,
  * Adapted for busybox David Kimdon <dwhedon@gordian.com>
  *
  * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
  */

 /* NB: we have a problem here with /proc/NN/exe usage, similar to
  * one fixed in killall/pidof */

 #include <getopt.h>
 #include <sys/resource.h>

 /* Override ENABLE_FEATURE_PIDFILE */
 #define WANT_PIDFILE 1
 #include "libbb.h"

 static int signal_nr = 15;
 static int user_id = -1;
 static char *userspec;
 static char *cmdname;
 static char *execname;
 static char *pidfile;
 static smallint quiet;

 struct pid_list {
 	struct pid_list *next;
 	pid_t pid;
 };

 static struct pid_list *found;

 static int pid_is_exec(pid_t pid, const char *name)
 {
 	char buf[sizeof("/proc//exe") + sizeof(int)*3];
 	char *execbuf;
 	int n;

 	sprintf(buf, "/proc/%u/exe", pid);
 	n = strlen(name) + 1;
 	execbuf = xzalloc(n + 1);
 	readlink(buf, execbuf, n);

 	/* if readlink fails, execbuf still contains "" */
 	n = strcmp(execbuf, name);
 	if (ENABLE_FEATURE_CLEAN_UP)
 		free(execbuf);
 	return !n; /* nonzero (true) if execbuf == name */
 }

 static int pid_is_user(int pid, int uid)
 {
 	struct stat sb;
 	char buf[sizeof("/proc/") + sizeof(int)*3];

 	sprintf(buf, "/proc/%u", pid);
 	if (stat(buf, &sb) != 0)
 		return 0;
 	return (sb.st_uid == uid);
 }

 static int pid_is_cmd(pid_t pid, const char *name)
 {
 	char fname[sizeof("/proc//stat") + sizeof(int)*3];
 	char *buf;
 	int r = 0;

 	sprintf(fname, "/proc/%u/stat", pid);
 	buf = xmalloc_open_read_close(fname, NULL);
 	if (buf) {
 		char *p = strchr(buf, '(');
 		if (p) {
 			char *pe = strrchr(++p, ')');
 			if (pe) {
 				*pe = '\0';
 				r = !strcmp(p, name);
 			}
 		}
 		free(buf);
 	}
 	return r;
 }

 static void check(int pid)
 {
 	struct pid_list *p;

 	if (execname && !pid_is_exec(pid, execname)) {
 		return;
 	}
 	if (userspec && !pid_is_user(pid, user_id)) {
 		return;
 	}
 	if (cmdname && !pid_is_cmd(pid, cmdname)) {
 		return;
 	}
 	p = xmalloc(sizeof(*p));
 	p->next = found;
 	p->pid = pid;
 	found = p;
 }

 static void do_pidfile(void)
 {
 	FILE *f;
 	unsigned pid;

 	f = fopen(pidfile, "r");
 	if (f) {
 		if (fscanf(f, "%u", &pid) == 1)
 			check(pid);
 		fclose(f);
 	} else if (errno != ENOENT)
 		bb_perror_msg_and_die("open pidfile %s", pidfile);
 }

 static void do_procinit(void)
 {
 	DIR *procdir;
 	struct dirent *entry;
 	int foundany, pid;

 	if (pidfile) {
 		do_pidfile();
 		return;
 	}

 	procdir = xopendir("/proc");

 	foundany = 0;
 	while ((entry = readdir(procdir)) != NULL) {
 		pid = bb_strtou(entry->d_name, NULL, 10);
 		if (errno)
 			continue;
 		foundany++;
 		check(pid);
 	}
 	closedir(procdir);
 	if (!foundany)
 		bb_error_msg_and_die("nothing in /proc - not mounted?");
 }

 static int do_stop(void)
 {
 	char *what;
 	struct pid_list *p;
 	int killed = 0;

 	do_procinit();

 	if (cmdname) {
 		if (ENABLE_FEATURE_CLEAN_UP) what = xstrdup(cmdname);
 		if (!ENABLE_FEATURE_CLEAN_UP) what = cmdname;
 	} else if (execname) {
 		if (ENABLE_FEATURE_CLEAN_UP) what = xstrdup(execname);
 		if (!ENABLE_FEATURE_CLEAN_UP) what = execname;
 	} else if (pidfile)
 		what = xasprintf("process in pidfile '%s'", pidfile);
 	else if (userspec)
 		what = xasprintf("process(es) owned by '%s'", userspec);
 	else
 		bb_error_msg_and_die("internal error, please report");

 	if (!found) {
 		if (!quiet)
 			printf("no %s found; none killed\n", what);
 		killed = -1;
 		goto ret;
 	}
 	for (p = found; p; p = p->next) {
 		if (kill(p->pid, signal_nr) == 0) {
 			p->pid = - p->pid;
 			killed++;
 		} else {
 			bb_perror_msg("warning: killing process %u", p->pid);
 		}
 	}
 	if (!quiet && killed) {
 		printf("stopped %s (pid", what);
 		for (p = found; p; p = p->next)
 			if (p->pid < 0)
 				printf(" %u", - p->pid);
 		puts(")");
 	}
  ret:
 	if (ENABLE_FEATURE_CLEAN_UP)
 		free(what);
 	return killed;
 }

 #if ENABLE_FEATURE_START_STOP_DAEMON_LONG_OPTIONS
 static const char start_stop_daemon_longopts[] ALIGN1 =
 	"stop\0"         No_argument       "K"
 	"start\0"        No_argument       "S"
 	"background\0"   No_argument       "b"
 	"quiet\0"        No_argument       "q"
 	"make-pidfile\0" No_argument       "m"
 #if ENABLE_FEATURE_START_STOP_DAEMON_FANCY
 	"oknodo\0"       No_argument       "o"
 	"verbose\0"      No_argument       "v"
 	"nicelevel\0"    Required_argument "N"
 #endif
 	"startas\0"      Required_argument "a"
 	"name\0"         Required_argument "n"
 	"signal\0"       Required_argument "s"
 	"user\0"         Required_argument "u"
 	"chuid\0"        Required_argument "c"
 	"exec\0"         Required_argument "x"
 	"pidfile\0"      Required_argument "p"
 #if ENABLE_FEATURE_START_STOP_DAEMON_FANCY
 	"retry\0"        Required_argument "R"
 #endif
 	;
 #endif

 enum {
 	CTX_STOP       = 0x1,
 	CTX_START      = 0x2,
 	OPT_BACKGROUND = 0x4, // -b
 	OPT_QUIET      = 0x8, // -q
 	OPT_MAKEPID    = 0x10, // -m
 	OPT_a          = 0x20, // -a
 	OPT_n          = 0x40, // -n
 	OPT_s          = 0x80, // -s
 	OPT_u          = 0x100, // -u
 	OPT_c          = 0x200, // -c
 	OPT_x          = 0x400, // -x
 	OPT_p          = 0x800, // -p
 	OPT_OKNODO     = 0x1000 * ENABLE_FEATURE_START_STOP_DAEMON_FANCY, // -o
 	OPT_VERBOSE    = 0x2000 * ENABLE_FEATURE_START_STOP_DAEMON_FANCY, // -v
 	OPT_NICELEVEL  = 0x4000 * ENABLE_FEATURE_START_STOP_DAEMON_FANCY, // -N
 };

 int start_stop_daemon_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
 int start_stop_daemon_main(int argc, char **argv)
 {
 	unsigned opt;
 	char *signame;
 	char *startas;
 	char *chuid;
 #if ENABLE_FEATURE_START_STOP_DAEMON_FANCY
 //	char *retry_arg = NULL;
 //	int retries = -1;
 	char *opt_N;
 #endif
 #if ENABLE_FEATURE_START_STOP_DAEMON_LONG_OPTIONS
 	applet_long_options = start_stop_daemon_longopts;
 #endif

 	/* Check required one context option was given */
 	opt_complementary = "K:S:K--S:S--K:m?p:K?xpun:S?xa";
 	opt = getopt32(argv, "KSbqma:n:s:u:c:x:p:"
 		USE_FEATURE_START_STOP_DAEMON_FANCY("ovN:"),
 //		USE_FEATURE_START_STOP_DAEMON_FANCY("ovN:R:"),
 		&startas, &cmdname, &signame, &userspec, &chuid, &execname, &pidfile
 		USE_FEATURE_START_STOP_DAEMON_FANCY(,&opt_N)
 //		USE_FEATURE_START_STOP_DAEMON_FANCY(,&retry_arg)
 	);

 	quiet = (opt & OPT_QUIET) && !(opt & OPT_VERBOSE);

 	if (opt & OPT_s) {
 		signal_nr = get_signum(signame);
 		if (signal_nr < 0) bb_show_usage();
 	}

 	if (!(opt & OPT_a))
 		startas = execname;

 //	USE_FEATURE_START_STOP_DAEMON_FANCY(
 //		if (retry_arg)
 //			retries = xatoi_u(retry_arg);
 //	)
 	argc -= optind;
 	argv += optind;

 	if (userspec) {
 		user_id = bb_strtou(userspec, NULL, 10);
 		if (errno)
 			user_id = xuname2uid(userspec);
 	}

 	if (opt & CTX_STOP) {
 		int i = do_stop();
 		return (opt & OPT_OKNODO) ? 0 : (i <= 0);
 	}

 	do_procinit();

 	if (found) {
 		if (!quiet)
 			printf("%s already running\n%d\n", execname, found->pid);
 		return !(opt & OPT_OKNODO);
 	}
 	*--argv = startas;
 	if (opt & OPT_BACKGROUND) {
 #if BB_MMU
 		bb_daemonize(0);
 #else
 		pid_t pid = vfork();
 		if (pid < 0) /* error */
 			bb_perror_msg_and_die("vfork");
 		if (pid != 0) {
 			/* parent */
 			/* why _exit? the child may have changed the stack,
 			 * so "return 0" may do bad things */
 			_exit(0);
 		}
 		/* child */
 		setsid(); /* detach from controlling tty */
 		/* Redirect stdio to /dev/null, close extra FDs.
 		 * We do not actually daemonize because of DAEMON_ONLY_SANITIZE */
 		bb_daemonize_or_rexec(
 			DAEMON_DEVNULL_STDIO
 			+ DAEMON_CLOSE_EXTRA_FDS
 			+ DAEMON_ONLY_SANITIZE,
 			NULL /* argv, unused */ );
 #endif
 	}
 	if (opt & OPT_MAKEPID) {
 		/* user wants _us_ to make the pidfile */
 		write_pidfile(pidfile);
 	}
 	if (opt & OPT_c) {
 		struct bb_uidgid_t ugid;
 		parse_chown_usergroup_or_die(&ugid, chuid);
 		if (ugid.gid != (gid_t) -1) xsetgid(ugid.gid);
 		if (ugid.uid != (uid_t) -1) xsetuid(ugid.uid);
 	}
 #if ENABLE_FEATURE_START_STOP_DAEMON_FANCY
 	if (opt & OPT_NICELEVEL) {
 		/* Set process priority */
 		int prio = getpriority(PRIO_PROCESS, 0) + xatoi_range(opt_N, INT_MIN/2, INT_MAX/2);
 		if (setpriority(PRIO_PROCESS, 0, prio) < 0) {
 			bb_perror_msg_and_die("setpriority(%d)", prio);
 		}
 	}
 #endif
 	execv(startas, argv);
 	bb_perror_msg_and_die("cannot start %s", startas);
 }
	/* vi: set sw=4 ts=4: */
	/*
	* Mini start-stop-daemon implementation(s) for busybox
	*
	* Written by Marek Michalkiewicz <marekm@i17linuxb.ists.pwr.wroc.pl>,
	* Adapted for busybox David Kimdon <dwhedon@gordian.com>
	*
	* Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
	*/

	/* NB: we have a problem here with /proc/NN/exe usage, similar to
	* one fixed in killall/pidof */

	#include <getopt.h>
	#include <sys/resource.h>

	/* Override ENABLE_FEATURE_PIDFILE */
	#define WANT_PIDFILE 1
	#include "libbb.h"

	static int signal_nr = 15;
	static int user_id = -1;
	static char *userspec;
	static char *cmdname;
	static char *execname;
	static char *pidfile;
	static smallint quiet;

	struct pid_list {
	struct pid_list *next;
	pid_t pid;
	};

	static struct pid_list *found;

	static int pid_is_exec(pid_t pid, const char *name)
	{
	char buf[sizeof("/proc//exe") + sizeof(int)*3];
	char *execbuf;
	int n;

	sprintf(buf, "/proc/%u/exe", pid);
	n = strlen(name) + 1;
	execbuf = xzalloc(n + 1);
	readlink(buf, execbuf, n);

	/* if readlink fails, execbuf still contains "" */
	n = strcmp(execbuf, name);
	if (ENABLE_FEATURE_CLEAN_UP)
	free(execbuf);
	return !n; /* nonzero (true) if execbuf == name */
	}

	static int pid_is_user(int pid, int uid)
	{
	struct stat sb;
	char buf[sizeof("/proc/") + sizeof(int)*3];

	sprintf(buf, "/proc/%u", pid);
	if (stat(buf, &sb) != 0)
	return 0;
	return (sb.st_uid == uid);
	}

	static int pid_is_cmd(pid_t pid, const char *name)
	{
	char fname[sizeof("/proc//stat") + sizeof(int)*3];
	char *buf;
	int r = 0;

	sprintf(fname, "/proc/%u/stat", pid);
	buf = xmalloc_open_read_close(fname, NULL);
	if (buf) {
	char *p = strchr(buf, '(');
	if (p) {
	char *pe = strrchr(++p, ')');
	if (pe) {
	*pe = '\0';
	r = !strcmp(p, name);
	}
	}
	free(buf);
	}
	return r;
	}

	static void check(int pid)
	{
	struct pid_list *p;

	if (execname && !pid_is_exec(pid, execname)) {
	return;
	}
	if (userspec && !pid_is_user(pid, user_id)) {
	return;
	}
	if (cmdname && !pid_is_cmd(pid, cmdname)) {
	return;
	}
	p = xmalloc(sizeof(*p));
	p->next = found;
	p->pid = pid;
	found = p;
	}

	static void do_pidfile(void)
	{
	FILE *f;
	unsigned pid;

	f = fopen(pidfile, "r");
	if (f) {
	if (fscanf(f, "%u", &pid) == 1)
	check(pid);
	fclose(f);
	} else if (errno != ENOENT)
	bb_perror_msg_and_die("open pidfile %s", pidfile);
	}

	static void do_procinit(void)
	{
	DIR *procdir;
	struct dirent *entry;
	int foundany, pid;

	if (pidfile) {
	do_pidfile();
	return;
	}

	procdir = xopendir("/proc");

	foundany = 0;
	while ((entry = readdir(procdir)) != NULL) {
	pid = bb_strtou(entry->d_name, NULL, 10);
	if (errno)
	continue;
	foundany++;
	check(pid);
	}
	closedir(procdir);
	if (!foundany)
	bb_error_msg_and_die("nothing in /proc - not mounted?");
	}

	static int do_stop(void)
	{
	char *what;
	struct pid_list *p;
	int killed = 0;

	do_procinit();

	if (cmdname) {
	if (ENABLE_FEATURE_CLEAN_UP) what = xstrdup(cmdname);
	if (!ENABLE_FEATURE_CLEAN_UP) what = cmdname;
	} else if (execname) {
	if (ENABLE_FEATURE_CLEAN_UP) what = xstrdup(execname);
	if (!ENABLE_FEATURE_CLEAN_UP) what = execname;
	} else if (pidfile)
	what = xasprintf("process in pidfile '%s'", pidfile);
	else if (userspec)
	what = xasprintf("process(es) owned by '%s'", userspec);
	else
	bb_error_msg_and_die("internal error, please report");

	if (!found) {
	if (!quiet)
	printf("no %s found; none killed\n", what);
	killed = -1;
	goto ret;
	}
	for (p = found; p; p = p->next) {
	if (kill(p->pid, signal_nr) == 0) {
	p->pid = - p->pid;
	killed++;
	} else {
	bb_perror_msg("warning: killing process %u", p->pid);
	}
	}
	if (!quiet && killed) {
	printf("stopped %s (pid", what);
	for (p = found; p; p = p->next)
	if (p->pid < 0)
	printf(" %u", - p->pid);
	puts(")");
	}
	ret:
	if (ENABLE_FEATURE_CLEAN_UP)
	free(what);
	return killed;
	}

	#if ENABLE_FEATURE_START_STOP_DAEMON_LONG_OPTIONS
	static const char start_stop_daemon_longopts[] ALIGN1 =
	"stop\0" No_argument "K"
	"start\0" No_argument "S"
	"background\0" No_argument "b"
	"quiet\0" No_argument "q"
	"make-pidfile\0" No_argument "m"
	#if ENABLE_FEATURE_START_STOP_DAEMON_FANCY
	"oknodo\0" No_argument "o"
	"verbose\0" No_argument "v"
	"nicelevel\0" Required_argument "N"
	#endif
	"startas\0" Required_argument "a"
	"name\0" Required_argument "n"
	"signal\0" Required_argument "s"
	"user\0" Required_argument "u"
	"chuid\0" Required_argument "c"
	"exec\0" Required_argument "x"
	"pidfile\0" Required_argument "p"
	#if ENABLE_FEATURE_START_STOP_DAEMON_FANCY
	"retry\0" Required_argument "R"
	#endif
	;
	#endif

	enum {
	CTX_STOP = 0x1,
	CTX_START = 0x2,
	OPT_BACKGROUND = 0x4, // -b
	OPT_QUIET = 0x8, // -q
	OPT_MAKEPID = 0x10, // -m
	OPT_a = 0x20, // -a
	OPT_n = 0x40, // -n
	OPT_s = 0x80, // -s
	OPT_u = 0x100, // -u
	OPT_c = 0x200, // -c
	OPT_x = 0x400, // -x
	OPT_p = 0x800, // -p
	OPT_OKNODO = 0x1000 * ENABLE_FEATURE_START_STOP_DAEMON_FANCY, // -o
	OPT_VERBOSE = 0x2000 * ENABLE_FEATURE_START_STOP_DAEMON_FANCY, // -v
	OPT_NICELEVEL = 0x4000 * ENABLE_FEATURE_START_STOP_DAEMON_FANCY, // -N
	};

	int start_stop_daemon_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
	int start_stop_daemon_main(int argc, char **argv)
	{
	unsigned opt;
	char *signame;
	char *startas;
	char *chuid;
	#if ENABLE_FEATURE_START_STOP_DAEMON_FANCY
	// char *retry_arg = NULL;
	// int retries = -1;
	char *opt_N;
	#endif
	#if ENABLE_FEATURE_START_STOP_DAEMON_LONG_OPTIONS
	applet_long_options = start_stop_daemon_longopts;
	#endif

	/* Check required one context option was given */
	opt_complementary = "K:S:K--S:S--K:m?p:K?xpun:S?xa";
	opt = getopt32(argv, "KSbqma:n:s:u:c:x:p:"
	USE_FEATURE_START_STOP_DAEMON_FANCY("ovN:"),
	// USE_FEATURE_START_STOP_DAEMON_FANCY("ovN:R:"),
	&startas, &cmdname, &signame, &userspec, &chuid, &execname, &pidfile
	USE_FEATURE_START_STOP_DAEMON_FANCY(,&opt_N)
	// USE_FEATURE_START_STOP_DAEMON_FANCY(,&retry_arg)
	);

	quiet = (opt & OPT_QUIET) && !(opt & OPT_VERBOSE);

	if (opt & OPT_s) {
	signal_nr = get_signum(signame);
	if (signal_nr < 0) bb_show_usage();
	}

	if (!(opt & OPT_a))
	startas = execname;

	// USE_FEATURE_START_STOP_DAEMON_FANCY(
	// if (retry_arg)
	// retries = xatoi_u(retry_arg);
	// )
	argc -= optind;
	argv += optind;

	if (userspec) {
	user_id = bb_strtou(userspec, NULL, 10);
	if (errno)
	user_id = xuname2uid(userspec);
	}

	if (opt & CTX_STOP) {
	int i = do_stop();
	return (opt & OPT_OKNODO) ? 0 : (i <= 0);
	}

	do_procinit();

	if (found) {
	if (!quiet)
	printf("%s already running\n%d\n", execname, found->pid);
	return !(opt & OPT_OKNODO);
	}
	*--argv = startas;
	if (opt & OPT_BACKGROUND) {
	#if BB_MMU
	bb_daemonize(0);
	#else
	pid_t pid = vfork();
	if (pid < 0) /* error */
	bb_perror_msg_and_die("vfork");
	if (pid != 0) {
	/* parent */
	/* why _exit? the child may have changed the stack,
	* so "return 0" may do bad things */
	_exit(0);
	}
	/* child */
	setsid(); /* detach from controlling tty */
	/* Redirect stdio to /dev/null, close extra FDs.
	* We do not actually daemonize because of DAEMON_ONLY_SANITIZE */
	bb_daemonize_or_rexec(
	DAEMON_DEVNULL_STDIO
	+ DAEMON_CLOSE_EXTRA_FDS
	+ DAEMON_ONLY_SANITIZE,
	NULL /* argv, unused */ );
	#endif
	}
	if (opt & OPT_MAKEPID) {
	/* user wants _us_ to make the pidfile */
	write_pidfile(pidfile);
	}
	if (opt & OPT_c) {
	struct bb_uidgid_t ugid;
	parse_chown_usergroup_or_die(&ugid, chuid);
	if (ugid.gid != (gid_t) -1) xsetgid(ugid.gid);
	if (ugid.uid != (uid_t) -1) xsetuid(ugid.uid);
	}
	#if ENABLE_FEATURE_START_STOP_DAEMON_FANCY
	if (opt & OPT_NICELEVEL) {
	/* Set process priority */
	int prio = getpriority(PRIO_PROCESS, 0) + xatoi_range(opt_N, INT_MIN/2, INT_MAX/2);
	if (setpriority(PRIO_PROCESS, 0, prio) < 0) {
	bb_perror_msg_and_die("setpriority(%d)", prio);
	}
	}
	#endif
	execv(startas, argv);
	bb_perror_msg_and_die("cannot start %s", startas);
	}