1 /* vi: set sw=4 ts=4: */
3 * Mini start-stop-daemon implementation(s) for busybox
5 * Written by Marek Michalkiewicz <marekm@i17linuxb.ists.pwr.wroc.pl>,
6 * Adapted for busybox David Kimdon <dwhedon@gordian.com>
8 * Licensed under GPLv2 or later, see file LICENSE in this source tree.
12 This is how it is supposed to work:
14 start-stop-daemon [OPTIONS] [--start|--stop] [[--] arguments...]
16 One (only) of these must be given:
20 Search for matching processes.
21 If --stop is given, stop all matching processes (by sending a signal).
22 If --start is given, start a new process unless a matching process was found.
24 Options controlling process matching
25 (if multiple conditions are specified, all must match):
26 -u,--user USERNAME|UID Only consider this user's processes
27 -n,--name PROCESS_NAME Look for processes by matching PROCESS_NAME
28 with comm field in /proc/$PID/stat.
29 Only basename is compared:
30 "ntpd" == "./ntpd" == "/path/to/ntpd".
31 [TODO: can PROCESS_NAME be a full pathname? Should we require full match then
32 with /proc/$PID/exe or argv[0] (comm can't be matched, it never contains path)]
33 -x,--exec EXECUTABLE Look for processes that were started with this
34 command in /proc/$PID/exe and /proc/$PID/cmdline
35 (/proc/$PID/cmdline is a bbox extension)
36 Unlike -n, we match against the full path:
37 "ntpd" != "./ntpd" != "/path/to/ntpd"
38 -p,--pidfile PID_FILE Look for processes with PID from this file
40 Options which are valid for --start only:
41 -x,--exec EXECUTABLE Program to run (1st arg of execvp). Mandatory.
42 -a,--startas NAME argv[0] (defaults to EXECUTABLE)
43 -b,--background Put process into background
44 -N,--nicelevel N Add N to process' nice level
45 -c,--chuid USER[:[GRP]] Change to specified user [and group]
46 -m,--make-pidfile Write PID to the pidfile
47 (both -m and -p must be given!)
49 Options which are valid for --stop only:
50 -s,--signal SIG Signal to send (default:TERM)
51 -t,--test Exit with status 0 if process is found
52 (we don't actually start or stop daemons)
55 -o,--oknodo Exit with status 0 if nothing is done
59 //config:config START_STOP_DAEMON
60 //config: bool "start-stop-daemon (12 kb)"
63 //config: start-stop-daemon is used to control the creation and
64 //config: termination of system-level processes, usually the ones
65 //config: started during the startup of the system.
67 //config:config FEATURE_START_STOP_DAEMON_LONG_OPTIONS
68 //config: bool "Enable long options"
70 //config: depends on START_STOP_DAEMON && LONG_OPTS
72 //config:config FEATURE_START_STOP_DAEMON_FANCY
73 //config: bool "Support additional arguments"
75 //config: depends on START_STOP_DAEMON
77 //config: -o|--oknodo ignored since we exit with 0 anyway
78 //config: -v|--verbose
79 //config: -N|--nicelevel N
81 //applet:IF_START_STOP_DAEMON(APPLET_ODDNAME(start-stop-daemon, start_stop_daemon, BB_DIR_SBIN, BB_SUID_DROP, start_stop_daemon))
82 /* not NOEXEC: uses bb_common_bufsiz1 */
84 //kbuild:lib-$(CONFIG_START_STOP_DAEMON) += start_stop_daemon.o
86 //usage:#define start_stop_daemon_trivial_usage
87 //usage: "[OPTIONS] [-S|-K] ... [-- ARGS...]"
88 //usage:#define start_stop_daemon_full_usage "\n\n"
89 //usage: "Search for matching processes, and then\n"
90 //usage: "-K: stop all matching processes.\n"
91 //usage: "-S: start a process unless a matching process is found.\n"
92 //usage: IF_FEATURE_START_STOP_DAEMON_LONG_OPTIONS(
93 //usage: "\nProcess matching:"
94 //usage: "\n -u,--user USERNAME|UID Match only this user's processes"
95 //usage: "\n -n,--name NAME Match processes with NAME"
96 //usage: "\n in comm field in /proc/PID/stat"
97 //usage: "\n -x,--exec EXECUTABLE Match processes with this command"
98 //usage: "\n in /proc/PID/{exe,cmdline}"
99 //usage: "\n -p,--pidfile FILE Match a process with PID from the file"
100 //usage: "\n All specified conditions must match"
101 //usage: "\n-S only:"
102 //usage: "\n -x,--exec EXECUTABLE Program to run"
103 //usage: "\n -a,--startas NAME Zeroth argument"
104 //usage: "\n -b,--background Background"
105 //usage: IF_FEATURE_START_STOP_DAEMON_FANCY(
106 //usage: "\n -N,--nicelevel N Change nice level"
108 //usage: "\n -c,--chuid USER[:[GRP]] Change to user/group"
109 //usage: "\n -m,--make-pidfile Write PID to the pidfile specified by -p"
110 //usage: "\n-K only:"
111 //usage: "\n -s,--signal SIG Signal to send"
112 //usage: "\n -t,--test Match only, exit with 0 if a process is found"
114 //usage: IF_FEATURE_START_STOP_DAEMON_FANCY(
115 //usage: "\n -o,--oknodo Exit with status 0 if nothing is done"
116 //usage: "\n -v,--verbose Verbose"
118 //usage: "\n -q,--quiet Quiet"
120 //usage: IF_NOT_FEATURE_START_STOP_DAEMON_LONG_OPTIONS(
121 //usage: "\nProcess matching:"
122 //usage: "\n -u USERNAME|UID Match only this user's processes"
123 //usage: "\n -n NAME Match processes with NAME"
124 //usage: "\n in comm field in /proc/PID/stat"
125 //usage: "\n -x EXECUTABLE Match processes with this command"
126 //usage: "\n command in /proc/PID/cmdline"
127 //usage: "\n -p FILE Match a process with PID from the file"
128 //usage: "\n All specified conditions must match"
129 //usage: "\n-S only:"
130 //usage: "\n -x EXECUTABLE Program to run"
131 //usage: "\n -a NAME Zeroth argument"
132 //usage: "\n -b Background"
133 //usage: IF_FEATURE_START_STOP_DAEMON_FANCY(
134 //usage: "\n -N N Change nice level"
136 //usage: "\n -c USER[:[GRP]] Change to user/group"
137 //usage: "\n -m Write PID to the pidfile specified by -p"
138 //usage: "\n-K only:"
139 //usage: "\n -s SIG Signal to send"
140 //usage: "\n -t Match only, exit with 0 if a process is found"
142 //usage: IF_FEATURE_START_STOP_DAEMON_FANCY(
143 //usage: "\n -o Exit with status 0 if nothing is done"
144 //usage: "\n -v Verbose"
146 //usage: "\n -q Quiet"
149 #include <sys/resource.h>
151 /* Override ENABLE_FEATURE_PIDFILE */
152 #define WANT_PIDFILE 1
154 #include "common_bufsiz.h"
157 struct pid_list *next;
163 CTX_START = (1 << 1),
164 OPT_BACKGROUND = (1 << 2), // -b
165 OPT_QUIET = (1 << 3), // -q
166 OPT_TEST = (1 << 4), // -t
167 OPT_MAKEPID = (1 << 5), // -m
168 OPT_a = (1 << 6), // -a
169 OPT_n = (1 << 7), // -n
170 OPT_s = (1 << 8), // -s
171 OPT_u = (1 << 9), // -u
172 OPT_c = (1 << 10), // -c
173 OPT_x = (1 << 11), // -x
174 OPT_p = (1 << 12), // -p
175 OPT_OKNODO = (1 << 13) * ENABLE_FEATURE_START_STOP_DAEMON_FANCY, // -o
176 OPT_VERBOSE = (1 << 14) * ENABLE_FEATURE_START_STOP_DAEMON_FANCY, // -v
177 OPT_NICELEVEL = (1 << 15) * ENABLE_FEATURE_START_STOP_DAEMON_FANCY, // -N
179 #define QUIET (option_mask32 & OPT_QUIET)
180 #define TEST (option_mask32 & OPT_TEST)
183 struct pid_list *found_procs;
188 char *execname_cmpbuf;
189 unsigned execname_sizeof;
193 #define G (*(struct globals*)bb_common_bufsiz1)
194 #define userspec (G.userspec )
195 #define cmdname (G.cmdname )
196 #define execname (G.execname )
197 #define pidfile (G.pidfile )
198 #define user_id (G.user_id )
199 #define signal_nr (G.signal_nr )
200 #define INIT_G() do { \
201 setup_common_bufsiz(); \
206 #ifdef OLDER_VERSION_OF_X
207 /* -x,--exec EXECUTABLE
208 * Look for processes with matching /proc/$PID/exe.
209 * Match is performed using device+inode.
211 static int pid_is_exec(pid_t pid)
214 char buf[sizeof("/proc/%u/exe") + sizeof(int)*3];
216 sprintf(buf, "/proc/%u/exe", (unsigned)pid);
217 if (stat(buf, &st) < 0)
219 if (st.st_dev == execstat.st_dev
220 && st.st_ino == execstat.st_ino)
226 static int pid_is_exec(pid_t pid)
229 char buf[sizeof("/proc/%u/cmdline") + sizeof(int)*3];
230 char *procname, *exelink;
233 procname = buf + sprintf(buf, "/proc/%u/exe", (unsigned)pid) - 3;
235 exelink = xmalloc_readlink(buf);
236 match = (exelink && strcmp(execname, exelink) == 0);
241 strcpy(procname, "cmdline");
242 bytes = open_read_close(buf, G.execname_cmpbuf, G.execname_sizeof);
244 G.execname_cmpbuf[bytes] = '\0';
245 return strcmp(execname, G.execname_cmpbuf) == 0;
250 static int pid_is_name(pid_t pid)
252 /* /proc/PID/stat is "PID (comm_15_bytes_max) ..." */
253 char buf[32]; /* should be enough */
256 sprintf(buf, "/proc/%u/stat", (unsigned)pid);
257 if (open_read_close(buf, buf, sizeof(buf) - 1) < 0)
259 buf[sizeof(buf) - 1] = '\0'; /* paranoia */
260 p = strchr(buf, '(');
263 pe = strrchr(++p, ')');
267 /* we require comm to match and to not be truncated */
268 /* in Linux, if comm is 15 chars, it may be a truncated
269 * name, so we don't allow that to match */
270 if (strlen(p) >= COMM_LEN - 1) /* COMM_LEN is 16 */
272 return strcmp(p, cmdname) == 0;
275 static int pid_is_user(int pid)
278 char buf[sizeof("/proc/") + sizeof(int)*3];
280 sprintf(buf, "/proc/%u", (unsigned)pid);
281 if (stat(buf, &sb) != 0)
283 return (sb.st_uid == (uid_t)user_id);
286 static void check(int pid)
290 if (execname && !pid_is_exec(pid)) {
293 if (cmdname && !pid_is_name(pid)) {
296 if (userspec && !pid_is_user(pid)) {
299 p = xmalloc(sizeof(*p));
300 p->next = G.found_procs;
305 static void do_pidfile(void)
310 f = fopen_for_read(pidfile);
312 if (fscanf(f, "%u", &pid) == 1)
315 } else if (errno != ENOENT)
316 bb_perror_msg_and_die("open pidfile %s", pidfile);
319 static void do_procinit(void)
322 struct dirent *entry;
330 procdir = xopendir("/proc");
334 errno = 0; /* clear any previous error */
335 entry = readdir(procdir);
336 // TODO: this check is too generic, it's better
337 // to check for exact errno(s) which mean that we got stale entry
338 if (errno) /* Stale entry, process has died after opendir */
340 if (!entry) /* EOF, no more entries */
342 pid = bb_strtou(entry->d_name, NULL, 10);
349 bb_error_msg_and_die("nothing in /proc - not mounted?");
352 static int do_stop(void)
359 if (ENABLE_FEATURE_CLEAN_UP) what = xstrdup(cmdname);
360 if (!ENABLE_FEATURE_CLEAN_UP) what = cmdname;
361 } else if (execname) {
362 if (ENABLE_FEATURE_CLEAN_UP) what = xstrdup(execname);
363 if (!ENABLE_FEATURE_CLEAN_UP) what = execname;
364 } else if (pidfile) {
365 what = xasprintf("process in pidfile '%s'", pidfile);
366 } else if (userspec) {
367 what = xasprintf("process(es) owned by '%s'", userspec);
369 bb_error_msg_and_die("internal error, please report");
372 if (!G.found_procs) {
374 printf("no %s found; none killed\n", what);
378 for (p = G.found_procs; p; p = p->next) {
379 if (kill(p->pid, TEST ? 0 : signal_nr) == 0) {
382 bb_perror_msg("warning: killing process %u", (unsigned)p->pid);
385 /* Example: -K --test --pidfile PIDFILE detected
386 * that PIDFILE's pid doesn't exist */
392 if (!QUIET && killed) {
393 printf("stopped %s (pid", what);
394 for (p = G.found_procs; p; p = p->next)
396 printf(" %u", (unsigned)p->pid);
400 if (ENABLE_FEATURE_CLEAN_UP)
405 #if ENABLE_FEATURE_START_STOP_DAEMON_LONG_OPTIONS
406 static const char start_stop_daemon_longopts[] ALIGN1 =
407 "stop\0" No_argument "K"
408 "start\0" No_argument "S"
409 "background\0" No_argument "b"
410 "quiet\0" No_argument "q"
411 "test\0" No_argument "t"
412 "make-pidfile\0" No_argument "m"
413 # if ENABLE_FEATURE_START_STOP_DAEMON_FANCY
414 "oknodo\0" No_argument "o"
415 "verbose\0" No_argument "v"
416 "nicelevel\0" Required_argument "N"
418 "startas\0" Required_argument "a"
419 "name\0" Required_argument "n"
420 "signal\0" Required_argument "s"
421 "user\0" Required_argument "u"
422 "chuid\0" Required_argument "c"
423 "exec\0" Required_argument "x"
424 "pidfile\0" Required_argument "p"
425 # if ENABLE_FEATURE_START_STOP_DAEMON_FANCY
426 "retry\0" Required_argument "R"
429 # define GETOPT32 getopt32long
430 # define LONGOPTS start_stop_daemon_longopts,
432 # define GETOPT32 getopt32
436 int start_stop_daemon_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
437 int start_stop_daemon_main(int argc UNUSED_PARAM, char **argv)
443 #ifdef OLDER_VERSION_OF_X
444 struct stat execstat;
446 #if ENABLE_FEATURE_START_STOP_DAEMON_FANCY
447 // char *retry_arg = NULL;
454 /* -K or -S is required; they are mutually exclusive */
455 /* -p is required if -m is given */
456 /* -xpun (at least one) is required if -K is given */
457 /* -xa (at least one) is required if -S is given */
458 /* -q turns off -v */
459 opt_complementary = "K:S:K--S:S--K:m?p:K?xpun:S?xa"
460 IF_FEATURE_START_STOP_DAEMON_FANCY("q-v");
461 opt = GETOPT32(argv, "KSbqtma:n:s:u:c:x:p:"
462 IF_FEATURE_START_STOP_DAEMON_FANCY("ovN:R:"),
464 &startas, &cmdname, &signame, &userspec, &chuid, &execname, &pidfile
465 IF_FEATURE_START_STOP_DAEMON_FANCY(,&opt_N)
466 /* We accept and ignore -R <param> / --retry <param> */
467 IF_FEATURE_START_STOP_DAEMON_FANCY(,NULL)
471 signal_nr = get_signum(signame);
472 if (signal_nr < 0) bb_show_usage();
477 if (!execname) /* in case -a is given and -x is not */
480 G.execname_sizeof = strlen(execname) + 1;
481 G.execname_cmpbuf = xmalloc(G.execname_sizeof + 1);
484 // IF_FEATURE_START_STOP_DAEMON_FANCY(
486 // retries = xatoi_positive(retry_arg);
492 user_id = bb_strtou(userspec, NULL, 10);
494 user_id = xuname2uid(userspec);
496 /* Both start and stop need to know current processes */
499 if (opt & CTX_STOP) {
501 return (opt & OPT_OKNODO) ? 0 : (i <= 0);
506 printf("%s is already running\n%u\n", execname, (unsigned)G.found_procs->pid);
507 return !(opt & OPT_OKNODO);
510 #ifdef OLDER_VERSION_OF_X
512 xstat(execname, &execstat);
516 if (opt & OPT_BACKGROUND) {
518 bb_daemonize(DAEMON_DEVNULL_STDIO + DAEMON_CLOSE_EXTRA_FDS + DAEMON_DOUBLE_FORK);
519 /* DAEMON_DEVNULL_STDIO is superfluous -
520 * it's always done by bb_daemonize() */
522 /* Daemons usually call bb_daemonize_or_rexec(), but SSD can do
523 * without: SSD is not itself a daemon, it _execs_ a daemon.
524 * The usual NOMMU problem of "child can't run indefinitely,
525 * it must exec" does not bite us: we exec anyway.
527 pid_t pid = xvfork();
530 /* why _exit? the child may have changed the stack,
531 * so "return 0" may do bad things */
535 setsid(); /* detach from controlling tty */
536 /* Redirect stdio to /dev/null, close extra FDs */
537 bb_daemon_helper(DAEMON_DEVNULL_STDIO + DAEMON_CLOSE_EXTRA_FDS);
540 if (opt & OPT_MAKEPID) {
541 /* User wants _us_ to make the pidfile */
542 write_pidfile(pidfile);
545 struct bb_uidgid_t ugid;
546 parse_chown_usergroup_or_die(&ugid, chuid);
547 if (ugid.uid != (uid_t) -1L) {
548 struct passwd *pw = xgetpwuid(ugid.uid);
549 if (ugid.gid != (gid_t) -1L)
550 pw->pw_gid = ugid.gid;
551 /* initgroups, setgid, setuid: */
553 } else if (ugid.gid != (gid_t) -1L) {
555 setgroups(1, &ugid.gid);
558 #if ENABLE_FEATURE_START_STOP_DAEMON_FANCY
559 if (opt & OPT_NICELEVEL) {
560 /* Set process priority */
561 int prio = getpriority(PRIO_PROCESS, 0) + xatoi_range(opt_N, INT_MIN/2, INT_MAX/2);
562 if (setpriority(PRIO_PROCESS, 0, prio) < 0) {
563 bb_perror_msg_and_die("setpriority(%d)", prio);
567 execvp(startas, argv);
568 bb_perror_msg_and_die("can't execute '%s'", startas);