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/cmdline.
35 Unlike -n, we match against the full path:
36 "ntpd" != "./ntpd" != "/path/to/ntpd"
37 -p,--pidfile PID_FILE Look for processes with PID from this file
39 Options which are valid for --start only:
40 -x,--exec EXECUTABLE Program to run (1st arg of execvp). Mandatory.
41 -a,--startas NAME argv[0] (defaults to EXECUTABLE)
42 -b,--background Put process into background
43 -N,--nicelevel N Add N to process' nice level
44 -c,--chuid USER[:[GRP]] Change to specified user [and group]
45 -m,--make-pidfile Write PID to the pidfile
46 (both -m and -p must be given!)
48 Options which are valid for --stop only:
49 -s,--signal SIG Signal to send (default:TERM)
50 -t,--test Exit with status 0 if process is found
51 (we don't actually start or stop daemons)
54 -o,--oknodo Exit with status 0 if nothing is done
59 //usage:#define start_stop_daemon_trivial_usage
60 //usage: "[OPTIONS] [-S|-K] ... [-- ARGS...]"
61 //usage:#define start_stop_daemon_full_usage "\n\n"
62 //usage: "Search for matching processes, and then\n"
63 //usage: "-K: stop all matching processes.\n"
64 //usage: "-S: start a process unless a matching process is found.\n"
65 //usage: IF_FEATURE_START_STOP_DAEMON_LONG_OPTIONS(
66 //usage: "\nProcess matching:"
67 //usage: "\n -u,--user USERNAME|UID Match only this user's processes"
68 //usage: "\n -n,--name NAME Match processes with NAME"
69 //usage: "\n in comm field in /proc/PID/stat"
70 //usage: "\n -x,--exec EXECUTABLE Match processes with this command"
71 //usage: "\n in /proc/PID/cmdline"
72 //usage: "\n -p,--pidfile FILE Match a process with PID from the file"
73 //usage: "\n All specified conditions must match"
75 //usage: "\n -x,--exec EXECUTABLE Program to run"
76 //usage: "\n -a,--startas NAME Zeroth argument"
77 //usage: "\n -b,--background Background"
78 //usage: IF_FEATURE_START_STOP_DAEMON_FANCY(
79 //usage: "\n -N,--nicelevel N Change nice level"
81 //usage: "\n -c,--chuid USER[:[GRP]] Change to user/group"
82 //usage: "\n -m,--make-pidfile Write PID to the pidfile specified by -p"
84 //usage: "\n -s,--signal SIG Signal to send"
85 //usage: "\n -t,--test Match only, exit with 0 if a process is found"
87 //usage: IF_FEATURE_START_STOP_DAEMON_FANCY(
88 //usage: "\n -o,--oknodo Exit with status 0 if nothing is done"
89 //usage: "\n -v,--verbose Verbose"
91 //usage: "\n -q,--quiet Quiet"
93 //usage: IF_NOT_FEATURE_START_STOP_DAEMON_LONG_OPTIONS(
94 //usage: "\nProcess matching:"
95 //usage: "\n -u USERNAME|UID Match only this user's processes"
96 //usage: "\n -n NAME Match processes with NAME"
97 //usage: "\n in comm field in /proc/PID/stat"
98 //usage: "\n -x EXECUTABLE Match processes with this command"
99 //usage: "\n command in /proc/PID/cmdline"
100 //usage: "\n -p FILE Match a process with PID from the file"
101 //usage: "\n All specified conditions must match"
102 //usage: "\n-S only:"
103 //usage: "\n -x EXECUTABLE Program to run"
104 //usage: "\n -a NAME Zeroth argument"
105 //usage: "\n -b Background"
106 //usage: IF_FEATURE_START_STOP_DAEMON_FANCY(
107 //usage: "\n -N N Change nice level"
109 //usage: "\n -c USER[:[GRP]] Change to user/group"
110 //usage: "\n -m Write PID to the pidfile specified by -p"
111 //usage: "\n-K only:"
112 //usage: "\n -s SIG Signal to send"
113 //usage: "\n -t Match only, exit with 0 if a process is found"
115 //usage: IF_FEATURE_START_STOP_DAEMON_FANCY(
116 //usage: "\n -o Exit with status 0 if nothing is done"
117 //usage: "\n -v Verbose"
119 //usage: "\n -q Quiet"
122 #include <sys/resource.h>
124 /* Override ENABLE_FEATURE_PIDFILE */
125 #define WANT_PIDFILE 1
129 struct pid_list *next;
135 CTX_START = (1 << 1),
136 OPT_BACKGROUND = (1 << 2), // -b
137 OPT_QUIET = (1 << 3), // -q
138 OPT_TEST = (1 << 4), // -t
139 OPT_MAKEPID = (1 << 5), // -m
140 OPT_a = (1 << 6), // -a
141 OPT_n = (1 << 7), // -n
142 OPT_s = (1 << 8), // -s
143 OPT_u = (1 << 9), // -u
144 OPT_c = (1 << 10), // -c
145 OPT_x = (1 << 11), // -x
146 OPT_p = (1 << 12), // -p
147 OPT_OKNODO = (1 << 13) * ENABLE_FEATURE_START_STOP_DAEMON_FANCY, // -o
148 OPT_VERBOSE = (1 << 14) * ENABLE_FEATURE_START_STOP_DAEMON_FANCY, // -v
149 OPT_NICELEVEL = (1 << 15) * ENABLE_FEATURE_START_STOP_DAEMON_FANCY, // -N
151 #define QUIET (option_mask32 & OPT_QUIET)
152 #define TEST (option_mask32 & OPT_TEST)
155 struct pid_list *found_procs;
160 char *execname_cmpbuf;
161 unsigned execname_sizeof;
165 #define G (*(struct globals*)&bb_common_bufsiz1)
166 #define userspec (G.userspec )
167 #define cmdname (G.cmdname )
168 #define execname (G.execname )
169 #define pidfile (G.pidfile )
170 #define user_id (G.user_id )
171 #define signal_nr (G.signal_nr )
172 #define INIT_G() do { \
177 #ifdef OLDER_VERSION_OF_X
178 /* -x,--exec EXECUTABLE
179 * Look for processes with matching /proc/$PID/exe.
180 * Match is performed using device+inode.
182 static int pid_is_exec(pid_t pid)
185 char buf[sizeof("/proc/%u/exe") + sizeof(int)*3];
187 sprintf(buf, "/proc/%u/exe", (unsigned)pid);
188 if (stat(buf, &st) < 0)
190 if (st.st_dev == execstat.st_dev
191 && st.st_ino == execstat.st_ino)
197 static int pid_is_exec(pid_t pid)
200 char buf[sizeof("/proc/%u/cmdline") + sizeof(int)*3];
202 sprintf(buf, "/proc/%u/cmdline", (unsigned)pid);
203 bytes = open_read_close(buf, G.execname_cmpbuf, G.execname_sizeof);
205 G.execname_cmpbuf[bytes] = '\0';
206 return strcmp(execname, G.execname_cmpbuf) == 0;
211 static int pid_is_name(pid_t pid)
213 /* /proc/PID/stat is "PID (comm_15_bytes_max) ..." */
214 char buf[32]; /* should be enough */
217 sprintf(buf, "/proc/%u/stat", (unsigned)pid);
218 if (open_read_close(buf, buf, sizeof(buf) - 1) < 0)
220 buf[sizeof(buf) - 1] = '\0'; /* paranoia */
221 p = strchr(buf, '(');
224 pe = strrchr(++p, ')');
228 /* we require comm to match and to not be truncated */
229 /* in Linux, if comm is 15 chars, it may be a truncated
230 * name, so we don't allow that to match */
231 if (strlen(p) >= COMM_LEN - 1) /* COMM_LEN is 16 */
233 return strcmp(p, cmdname) == 0;
236 static int pid_is_user(int pid)
239 char buf[sizeof("/proc/") + sizeof(int)*3];
241 sprintf(buf, "/proc/%u", (unsigned)pid);
242 if (stat(buf, &sb) != 0)
244 return (sb.st_uid == (uid_t)user_id);
247 static void check(int pid)
251 if (execname && !pid_is_exec(pid)) {
254 if (cmdname && !pid_is_name(pid)) {
257 if (userspec && !pid_is_user(pid)) {
260 p = xmalloc(sizeof(*p));
261 p->next = G.found_procs;
266 static void do_pidfile(void)
271 f = fopen_for_read(pidfile);
273 if (fscanf(f, "%u", &pid) == 1)
276 } else if (errno != ENOENT)
277 bb_perror_msg_and_die("open pidfile %s", pidfile);
280 static void do_procinit(void)
283 struct dirent *entry;
291 procdir = xopendir("/proc");
295 errno = 0; /* clear any previous error */
296 entry = readdir(procdir);
297 // TODO: this check is too generic, it's better
298 // to check for exact errno(s) which mean that we got stale entry
299 if (errno) /* Stale entry, process has died after opendir */
301 if (!entry) /* EOF, no more entries */
303 pid = bb_strtou(entry->d_name, NULL, 10);
310 bb_error_msg_and_die("nothing in /proc - not mounted?");
313 static int do_stop(void)
320 if (ENABLE_FEATURE_CLEAN_UP) what = xstrdup(cmdname);
321 if (!ENABLE_FEATURE_CLEAN_UP) what = cmdname;
322 } else if (execname) {
323 if (ENABLE_FEATURE_CLEAN_UP) what = xstrdup(execname);
324 if (!ENABLE_FEATURE_CLEAN_UP) what = execname;
325 } else if (pidfile) {
326 what = xasprintf("process in pidfile '%s'", pidfile);
327 } else if (userspec) {
328 what = xasprintf("process(es) owned by '%s'", userspec);
330 bb_error_msg_and_die("internal error, please report");
333 if (!G.found_procs) {
335 printf("no %s found; none killed\n", what);
339 for (p = G.found_procs; p; p = p->next) {
340 if (kill(p->pid, TEST ? 0 : signal_nr) == 0) {
343 bb_perror_msg("warning: killing process %u", (unsigned)p->pid);
346 /* Example: -K --test --pidfile PIDFILE detected
347 * that PIDFILE's pid doesn't exist */
353 if (!QUIET && killed) {
354 printf("stopped %s (pid", what);
355 for (p = G.found_procs; p; p = p->next)
357 printf(" %u", (unsigned)p->pid);
361 if (ENABLE_FEATURE_CLEAN_UP)
366 #if ENABLE_FEATURE_START_STOP_DAEMON_LONG_OPTIONS
367 static const char start_stop_daemon_longopts[] ALIGN1 =
368 "stop\0" No_argument "K"
369 "start\0" No_argument "S"
370 "background\0" No_argument "b"
371 "quiet\0" No_argument "q"
372 "test\0" No_argument "t"
373 "make-pidfile\0" No_argument "m"
374 #if ENABLE_FEATURE_START_STOP_DAEMON_FANCY
375 "oknodo\0" No_argument "o"
376 "verbose\0" No_argument "v"
377 "nicelevel\0" Required_argument "N"
379 "startas\0" Required_argument "a"
380 "name\0" Required_argument "n"
381 "signal\0" Required_argument "s"
382 "user\0" Required_argument "u"
383 "chuid\0" Required_argument "c"
384 "exec\0" Required_argument "x"
385 "pidfile\0" Required_argument "p"
386 #if ENABLE_FEATURE_START_STOP_DAEMON_FANCY
387 "retry\0" Required_argument "R"
392 int start_stop_daemon_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
393 int start_stop_daemon_main(int argc UNUSED_PARAM, char **argv)
399 #ifdef OLDER_VERSION_OF_X
400 struct stat execstat;
402 #if ENABLE_FEATURE_START_STOP_DAEMON_FANCY
403 // char *retry_arg = NULL;
410 #if ENABLE_FEATURE_START_STOP_DAEMON_LONG_OPTIONS
411 applet_long_options = start_stop_daemon_longopts;
414 /* -K or -S is required; they are mutually exclusive */
415 /* -p is required if -m is given */
416 /* -xpun (at least one) is required if -K is given */
417 /* -xa (at least one) is required if -S is given */
418 /* -q turns off -v */
419 opt_complementary = "K:S:K--S:S--K:m?p:K?xpun:S?xa"
420 IF_FEATURE_START_STOP_DAEMON_FANCY("q-v");
421 opt = getopt32(argv, "KSbqtma:n:s:u:c:x:p:"
422 IF_FEATURE_START_STOP_DAEMON_FANCY("ovN:R:"),
423 &startas, &cmdname, &signame, &userspec, &chuid, &execname, &pidfile
424 IF_FEATURE_START_STOP_DAEMON_FANCY(,&opt_N)
425 /* We accept and ignore -R <param> / --retry <param> */
426 IF_FEATURE_START_STOP_DAEMON_FANCY(,NULL)
430 signal_nr = get_signum(signame);
431 if (signal_nr < 0) bb_show_usage();
436 if (!execname) /* in case -a is given and -x is not */
439 G.execname_sizeof = strlen(execname) + 1;
440 G.execname_cmpbuf = xmalloc(G.execname_sizeof + 1);
443 // IF_FEATURE_START_STOP_DAEMON_FANCY(
445 // retries = xatoi_positive(retry_arg);
451 user_id = bb_strtou(userspec, NULL, 10);
453 user_id = xuname2uid(userspec);
455 /* Both start and stop need to know current processes */
458 if (opt & CTX_STOP) {
460 return (opt & OPT_OKNODO) ? 0 : (i <= 0);
465 printf("%s is already running\n%u\n", execname, (unsigned)G.found_procs->pid);
466 return !(opt & OPT_OKNODO);
469 #ifdef OLDER_VERSION_OF_X
471 xstat(execname, &execstat);
475 if (opt & OPT_BACKGROUND) {
477 bb_daemonize(DAEMON_DEVNULL_STDIO + DAEMON_CLOSE_EXTRA_FDS);
478 /* DAEMON_DEVNULL_STDIO is superfluous -
479 * it's always done by bb_daemonize() */
481 pid_t pid = xvfork();
484 /* why _exit? the child may have changed the stack,
485 * so "return 0" may do bad things */
489 setsid(); /* detach from controlling tty */
490 /* Redirect stdio to /dev/null, close extra FDs.
491 * We do not actually daemonize because of DAEMON_ONLY_SANITIZE */
492 bb_daemonize_or_rexec(DAEMON_DEVNULL_STDIO
493 + DAEMON_CLOSE_EXTRA_FDS
494 + DAEMON_ONLY_SANITIZE,
495 NULL /* argv, unused */ );
498 if (opt & OPT_MAKEPID) {
499 /* User wants _us_ to make the pidfile */
500 write_pidfile(pidfile);
503 struct bb_uidgid_t ugid = { -1, -1 };
504 parse_chown_usergroup_or_die(&ugid, chuid);
505 if (ugid.gid != (gid_t) -1) xsetgid(ugid.gid);
506 if (ugid.uid != (uid_t) -1) xsetuid(ugid.uid);
508 #if ENABLE_FEATURE_START_STOP_DAEMON_FANCY
509 if (opt & OPT_NICELEVEL) {
510 /* Set process priority */
511 int prio = getpriority(PRIO_PROCESS, 0) + xatoi_range(opt_N, INT_MIN/2, INT_MAX/2);
512 if (setpriority(PRIO_PROCESS, 0, prio) < 0) {
513 bb_perror_msg_and_die("setpriority(%d)", prio);
517 execvp(startas, argv);
518 bb_perror_msg_and_die("can't execute '%s'", startas);