blob: 7dadc3c9eec0df0ee7c8e99e271de3a970d7fa4a
1 | /* vi: set sw=4 ts=4: */ |
2 | /* |
3 | * Mini start-stop-daemon implementation(s) for busybox |
4 | * |
5 | * Written by Marek Michalkiewicz <marekm@i17linuxb.ists.pwr.wroc.pl>, |
6 | * Adapted for busybox David Kimdon <dwhedon@gordian.com> |
7 | * |
8 | * Licensed under GPLv2 or later, see file LICENSE in this source tree. |
9 | */ |
10 | |
11 | /* |
12 | This is how it is supposed to work: |
13 | |
14 | start-stop-daemon [OPTIONS] [--start|--stop] [[--] arguments...] |
15 | |
16 | One (only) of these must be given: |
17 | -S,--start Start |
18 | -K,--stop Stop |
19 | |
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. |
23 | |
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 |
39 | |
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!) |
48 | |
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) |
53 | |
54 | Misc options: |
55 | -o,--oknodo Exit with status 0 if nothing is done |
56 | -q,--quiet Quiet |
57 | -v,--verbose Verbose |
58 | */ |
59 | |
60 | //usage:#define start_stop_daemon_trivial_usage |
61 | //usage: "[OPTIONS] [-S|-K] ... [-- ARGS...]" |
62 | //usage:#define start_stop_daemon_full_usage "\n\n" |
63 | //usage: "Search for matching processes, and then\n" |
64 | //usage: "-K: stop all matching processes.\n" |
65 | //usage: "-S: start a process unless a matching process is found.\n" |
66 | //usage: IF_FEATURE_START_STOP_DAEMON_LONG_OPTIONS( |
67 | //usage: "\nProcess matching:" |
68 | //usage: "\n -u,--user USERNAME|UID Match only this user's processes" |
69 | //usage: "\n -n,--name NAME Match processes with NAME" |
70 | //usage: "\n in comm field in /proc/PID/stat" |
71 | //usage: "\n -x,--exec EXECUTABLE Match processes with this command" |
72 | //usage: "\n in /proc/PID/{exe,cmdline}" |
73 | //usage: "\n -p,--pidfile FILE Match a process with PID from the file" |
74 | //usage: "\n All specified conditions must match" |
75 | //usage: "\n-S only:" |
76 | //usage: "\n -x,--exec EXECUTABLE Program to run" |
77 | //usage: "\n -a,--startas NAME Zeroth argument" |
78 | //usage: "\n -b,--background Background" |
79 | //usage: IF_FEATURE_START_STOP_DAEMON_FANCY( |
80 | //usage: "\n -N,--nicelevel N Change nice level" |
81 | //usage: ) |
82 | //usage: "\n -c,--chuid USER[:[GRP]] Change to user/group" |
83 | //usage: "\n -m,--make-pidfile Write PID to the pidfile specified by -p" |
84 | //usage: "\n-K only:" |
85 | //usage: "\n -s,--signal SIG Signal to send" |
86 | //usage: "\n -t,--test Match only, exit with 0 if a process is found" |
87 | //usage: "\nOther:" |
88 | //usage: IF_FEATURE_START_STOP_DAEMON_FANCY( |
89 | //usage: "\n -o,--oknodo Exit with status 0 if nothing is done" |
90 | //usage: "\n -v,--verbose Verbose" |
91 | //usage: ) |
92 | //usage: "\n -q,--quiet Quiet" |
93 | //usage: ) |
94 | //usage: IF_NOT_FEATURE_START_STOP_DAEMON_LONG_OPTIONS( |
95 | //usage: "\nProcess matching:" |
96 | //usage: "\n -u USERNAME|UID Match only this user's processes" |
97 | //usage: "\n -n NAME Match processes with NAME" |
98 | //usage: "\n in comm field in /proc/PID/stat" |
99 | //usage: "\n -x EXECUTABLE Match processes with this command" |
100 | //usage: "\n command in /proc/PID/cmdline" |
101 | //usage: "\n -p FILE Match a process with PID from the file" |
102 | //usage: "\n All specified conditions must match" |
103 | //usage: "\n-S only:" |
104 | //usage: "\n -x EXECUTABLE Program to run" |
105 | //usage: "\n -a NAME Zeroth argument" |
106 | //usage: "\n -b Background" |
107 | //usage: IF_FEATURE_START_STOP_DAEMON_FANCY( |
108 | //usage: "\n -N N Change nice level" |
109 | //usage: ) |
110 | //usage: "\n -c USER[:[GRP]] Change to user/group" |
111 | //usage: "\n -m Write PID to the pidfile specified by -p" |
112 | //usage: "\n-K only:" |
113 | //usage: "\n -s SIG Signal to send" |
114 | //usage: "\n -t Match only, exit with 0 if a process is found" |
115 | //usage: "\nOther:" |
116 | //usage: IF_FEATURE_START_STOP_DAEMON_FANCY( |
117 | //usage: "\n -o Exit with status 0 if nothing is done" |
118 | //usage: "\n -v Verbose" |
119 | //usage: ) |
120 | //usage: "\n -q Quiet" |
121 | //usage: ) |
122 | |
123 | #include <sys/resource.h> |
124 | |
125 | /* Override ENABLE_FEATURE_PIDFILE */ |
126 | #define WANT_PIDFILE 1 |
127 | #include "libbb.h" |
128 | |
129 | struct pid_list { |
130 | struct pid_list *next; |
131 | pid_t pid; |
132 | }; |
133 | |
134 | enum { |
135 | CTX_STOP = (1 << 0), |
136 | CTX_START = (1 << 1), |
137 | OPT_BACKGROUND = (1 << 2), // -b |
138 | OPT_QUIET = (1 << 3), // -q |
139 | OPT_TEST = (1 << 4), // -t |
140 | OPT_MAKEPID = (1 << 5), // -m |
141 | OPT_a = (1 << 6), // -a |
142 | OPT_n = (1 << 7), // -n |
143 | OPT_s = (1 << 8), // -s |
144 | OPT_u = (1 << 9), // -u |
145 | OPT_c = (1 << 10), // -c |
146 | OPT_x = (1 << 11), // -x |
147 | OPT_p = (1 << 12), // -p |
148 | OPT_OKNODO = (1 << 13) * ENABLE_FEATURE_START_STOP_DAEMON_FANCY, // -o |
149 | OPT_VERBOSE = (1 << 14) * ENABLE_FEATURE_START_STOP_DAEMON_FANCY, // -v |
150 | OPT_NICELEVEL = (1 << 15) * ENABLE_FEATURE_START_STOP_DAEMON_FANCY, // -N |
151 | }; |
152 | #define QUIET (option_mask32 & OPT_QUIET) |
153 | #define TEST (option_mask32 & OPT_TEST) |
154 | |
155 | struct globals { |
156 | struct pid_list *found_procs; |
157 | char *userspec; |
158 | char *cmdname; |
159 | char *execname; |
160 | char *pidfile; |
161 | char *execname_cmpbuf; |
162 | unsigned execname_sizeof; |
163 | int user_id; |
164 | smallint signal_nr; |
165 | } FIX_ALIASING; |
166 | #define G (*(struct globals*)&bb_common_bufsiz1) |
167 | #define userspec (G.userspec ) |
168 | #define cmdname (G.cmdname ) |
169 | #define execname (G.execname ) |
170 | #define pidfile (G.pidfile ) |
171 | #define user_id (G.user_id ) |
172 | #define signal_nr (G.signal_nr ) |
173 | #define INIT_G() do { \ |
174 | user_id = -1; \ |
175 | signal_nr = 15; \ |
176 | } while (0) |
177 | |
178 | #ifdef OLDER_VERSION_OF_X |
179 | /* -x,--exec EXECUTABLE |
180 | * Look for processes with matching /proc/$PID/exe. |
181 | * Match is performed using device+inode. |
182 | */ |
183 | static int pid_is_exec(pid_t pid) |
184 | { |
185 | struct stat st; |
186 | char buf[sizeof("/proc/%u/exe") + sizeof(int)*3]; |
187 | |
188 | sprintf(buf, "/proc/%u/exe", (unsigned)pid); |
189 | if (stat(buf, &st) < 0) |
190 | return 0; |
191 | if (st.st_dev == execstat.st_dev |
192 | && st.st_ino == execstat.st_ino) |
193 | return 1; |
194 | return 0; |
195 | } |
196 | #endif |
197 | |
198 | static int pid_is_exec(pid_t pid) |
199 | { |
200 | ssize_t bytes; |
201 | char buf[sizeof("/proc/%u/cmdline") + sizeof(int)*3]; |
202 | char *procname, *exelink; |
203 | int match; |
204 | |
205 | procname = buf + sprintf(buf, "/proc/%u/exe", (unsigned)pid) - 3; |
206 | |
207 | exelink = xmalloc_readlink(buf); |
208 | match = (exelink && strcmp(execname, exelink) == 0); |
209 | free(exelink); |
210 | if (match) |
211 | return match; |
212 | |
213 | strcpy(procname, "cmdline"); |
214 | bytes = open_read_close(buf, G.execname_cmpbuf, G.execname_sizeof); |
215 | if (bytes > 0) { |
216 | G.execname_cmpbuf[bytes] = '\0'; |
217 | return strcmp(execname, G.execname_cmpbuf) == 0; |
218 | } |
219 | return 0; |
220 | } |
221 | |
222 | static int pid_is_name(pid_t pid) |
223 | { |
224 | /* /proc/PID/stat is "PID (comm_15_bytes_max) ..." */ |
225 | char buf[32]; /* should be enough */ |
226 | char *p, *pe; |
227 | |
228 | sprintf(buf, "/proc/%u/stat", (unsigned)pid); |
229 | if (open_read_close(buf, buf, sizeof(buf) - 1) < 0) |
230 | return 0; |
231 | buf[sizeof(buf) - 1] = '\0'; /* paranoia */ |
232 | p = strchr(buf, '('); |
233 | if (!p) |
234 | return 0; |
235 | pe = strrchr(++p, ')'); |
236 | if (!pe) |
237 | return 0; |
238 | *pe = '\0'; |
239 | /* we require comm to match and to not be truncated */ |
240 | /* in Linux, if comm is 15 chars, it may be a truncated |
241 | * name, so we don't allow that to match */ |
242 | if (strlen(p) >= COMM_LEN - 1) /* COMM_LEN is 16 */ |
243 | return 0; |
244 | return strcmp(p, cmdname) == 0; |
245 | } |
246 | |
247 | static int pid_is_user(int pid) |
248 | { |
249 | struct stat sb; |
250 | char buf[sizeof("/proc/") + sizeof(int)*3]; |
251 | |
252 | sprintf(buf, "/proc/%u", (unsigned)pid); |
253 | if (stat(buf, &sb) != 0) |
254 | return 0; |
255 | return (sb.st_uid == (uid_t)user_id); |
256 | } |
257 | |
258 | static void check(int pid) |
259 | { |
260 | struct pid_list *p; |
261 | |
262 | if (execname && !pid_is_exec(pid)) { |
263 | return; |
264 | } |
265 | if (cmdname && !pid_is_name(pid)) { |
266 | return; |
267 | } |
268 | if (userspec && !pid_is_user(pid)) { |
269 | return; |
270 | } |
271 | p = xmalloc(sizeof(*p)); |
272 | p->next = G.found_procs; |
273 | p->pid = pid; |
274 | G.found_procs = p; |
275 | } |
276 | |
277 | static void do_pidfile(void) |
278 | { |
279 | FILE *f; |
280 | unsigned pid; |
281 | |
282 | f = fopen_for_read(pidfile); |
283 | if (f) { |
284 | if (fscanf(f, "%u", &pid) == 1) |
285 | check(pid); |
286 | fclose(f); |
287 | } else if (errno != ENOENT) |
288 | bb_perror_msg_and_die("open pidfile %s", pidfile); |
289 | } |
290 | |
291 | static void do_procinit(void) |
292 | { |
293 | DIR *procdir; |
294 | struct dirent *entry; |
295 | int pid; |
296 | |
297 | if (pidfile) { |
298 | do_pidfile(); |
299 | return; |
300 | } |
301 | |
302 | procdir = xopendir("/proc"); |
303 | |
304 | pid = 0; |
305 | while (1) { |
306 | errno = 0; /* clear any previous error */ |
307 | entry = readdir(procdir); |
308 | // TODO: this check is too generic, it's better |
309 | // to check for exact errno(s) which mean that we got stale entry |
310 | if (errno) /* Stale entry, process has died after opendir */ |
311 | continue; |
312 | if (!entry) /* EOF, no more entries */ |
313 | break; |
314 | pid = bb_strtou(entry->d_name, NULL, 10); |
315 | if (errno) /* NaN */ |
316 | continue; |
317 | check(pid); |
318 | } |
319 | closedir(procdir); |
320 | if (!pid) |
321 | bb_error_msg_and_die("nothing in /proc - not mounted?"); |
322 | } |
323 | |
324 | static int do_stop(void) |
325 | { |
326 | char *what; |
327 | struct pid_list *p; |
328 | int killed = 0; |
329 | |
330 | if (cmdname) { |
331 | if (ENABLE_FEATURE_CLEAN_UP) what = xstrdup(cmdname); |
332 | if (!ENABLE_FEATURE_CLEAN_UP) what = cmdname; |
333 | } else if (execname) { |
334 | if (ENABLE_FEATURE_CLEAN_UP) what = xstrdup(execname); |
335 | if (!ENABLE_FEATURE_CLEAN_UP) what = execname; |
336 | } else if (pidfile) { |
337 | what = xasprintf("process in pidfile '%s'", pidfile); |
338 | } else if (userspec) { |
339 | what = xasprintf("process(es) owned by '%s'", userspec); |
340 | } else { |
341 | bb_error_msg_and_die("internal error, please report"); |
342 | } |
343 | |
344 | if (!G.found_procs) { |
345 | if (!QUIET) |
346 | printf("no %s found; none killed\n", what); |
347 | killed = -1; |
348 | goto ret; |
349 | } |
350 | for (p = G.found_procs; p; p = p->next) { |
351 | if (kill(p->pid, TEST ? 0 : signal_nr) == 0) { |
352 | killed++; |
353 | } else { |
354 | bb_perror_msg("warning: killing process %u", (unsigned)p->pid); |
355 | p->pid = 0; |
356 | if (TEST) { |
357 | /* Example: -K --test --pidfile PIDFILE detected |
358 | * that PIDFILE's pid doesn't exist */ |
359 | killed = -1; |
360 | goto ret; |
361 | } |
362 | } |
363 | } |
364 | if (!QUIET && killed) { |
365 | printf("stopped %s (pid", what); |
366 | for (p = G.found_procs; p; p = p->next) |
367 | if (p->pid) |
368 | printf(" %u", (unsigned)p->pid); |
369 | puts(")"); |
370 | } |
371 | ret: |
372 | if (ENABLE_FEATURE_CLEAN_UP) |
373 | free(what); |
374 | return killed; |
375 | } |
376 | |
377 | #if ENABLE_FEATURE_START_STOP_DAEMON_LONG_OPTIONS |
378 | static const char start_stop_daemon_longopts[] ALIGN1 = |
379 | "stop\0" No_argument "K" |
380 | "start\0" No_argument "S" |
381 | "background\0" No_argument "b" |
382 | "quiet\0" No_argument "q" |
383 | "test\0" No_argument "t" |
384 | "make-pidfile\0" No_argument "m" |
385 | #if ENABLE_FEATURE_START_STOP_DAEMON_FANCY |
386 | "oknodo\0" No_argument "o" |
387 | "verbose\0" No_argument "v" |
388 | "nicelevel\0" Required_argument "N" |
389 | #endif |
390 | "startas\0" Required_argument "a" |
391 | "name\0" Required_argument "n" |
392 | "signal\0" Required_argument "s" |
393 | "user\0" Required_argument "u" |
394 | "chuid\0" Required_argument "c" |
395 | "exec\0" Required_argument "x" |
396 | "pidfile\0" Required_argument "p" |
397 | #if ENABLE_FEATURE_START_STOP_DAEMON_FANCY |
398 | "retry\0" Required_argument "R" |
399 | #endif |
400 | ; |
401 | #endif |
402 | |
403 | int start_stop_daemon_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; |
404 | int start_stop_daemon_main(int argc UNUSED_PARAM, char **argv) |
405 | { |
406 | unsigned opt; |
407 | char *signame; |
408 | char *startas; |
409 | char *chuid; |
410 | #ifdef OLDER_VERSION_OF_X |
411 | struct stat execstat; |
412 | #endif |
413 | #if ENABLE_FEATURE_START_STOP_DAEMON_FANCY |
414 | // char *retry_arg = NULL; |
415 | // int retries = -1; |
416 | char *opt_N; |
417 | #endif |
418 | |
419 | INIT_G(); |
420 | |
421 | #if ENABLE_FEATURE_START_STOP_DAEMON_LONG_OPTIONS |
422 | applet_long_options = start_stop_daemon_longopts; |
423 | #endif |
424 | |
425 | /* -K or -S is required; they are mutually exclusive */ |
426 | /* -p is required if -m is given */ |
427 | /* -xpun (at least one) is required if -K is given */ |
428 | /* -xa (at least one) is required if -S is given */ |
429 | /* -q turns off -v */ |
430 | opt_complementary = "K:S:K--S:S--K:m?p:K?xpun:S?xa" |
431 | IF_FEATURE_START_STOP_DAEMON_FANCY("q-v"); |
432 | opt = getopt32(argv, "KSbqtma:n:s:u:c:x:p:" |
433 | IF_FEATURE_START_STOP_DAEMON_FANCY("ovN:R:"), |
434 | &startas, &cmdname, &signame, &userspec, &chuid, &execname, &pidfile |
435 | IF_FEATURE_START_STOP_DAEMON_FANCY(,&opt_N) |
436 | /* We accept and ignore -R <param> / --retry <param> */ |
437 | IF_FEATURE_START_STOP_DAEMON_FANCY(,NULL) |
438 | ); |
439 | |
440 | if (opt & OPT_s) { |
441 | signal_nr = get_signum(signame); |
442 | if (signal_nr < 0) bb_show_usage(); |
443 | } |
444 | |
445 | if (!(opt & OPT_a)) |
446 | startas = execname; |
447 | if (!execname) /* in case -a is given and -x is not */ |
448 | execname = startas; |
449 | if (execname) { |
450 | G.execname_sizeof = strlen(execname) + 1; |
451 | G.execname_cmpbuf = xmalloc(G.execname_sizeof + 1); |
452 | } |
453 | |
454 | // IF_FEATURE_START_STOP_DAEMON_FANCY( |
455 | // if (retry_arg) |
456 | // retries = xatoi_positive(retry_arg); |
457 | // ) |
458 | //argc -= optind; |
459 | argv += optind; |
460 | |
461 | if (userspec) { |
462 | user_id = bb_strtou(userspec, NULL, 10); |
463 | if (errno) |
464 | user_id = xuname2uid(userspec); |
465 | } |
466 | /* Both start and stop need to know current processes */ |
467 | do_procinit(); |
468 | |
469 | if (opt & CTX_STOP) { |
470 | int i = do_stop(); |
471 | return (opt & OPT_OKNODO) ? 0 : (i <= 0); |
472 | } |
473 | |
474 | if (G.found_procs) { |
475 | if (!QUIET) |
476 | printf("%s is already running\n%u\n", execname, (unsigned)G.found_procs->pid); |
477 | return !(opt & OPT_OKNODO); |
478 | } |
479 | |
480 | #ifdef OLDER_VERSION_OF_X |
481 | if (execname) |
482 | xstat(execname, &execstat); |
483 | #endif |
484 | |
485 | *--argv = startas; |
486 | if (opt & OPT_BACKGROUND) { |
487 | #if BB_MMU |
488 | bb_daemonize(DAEMON_DEVNULL_STDIO + DAEMON_CLOSE_EXTRA_FDS + DAEMON_DOUBLE_FORK); |
489 | /* DAEMON_DEVNULL_STDIO is superfluous - |
490 | * it's always done by bb_daemonize() */ |
491 | #else |
492 | pid_t pid = xvfork(); |
493 | if (pid != 0) { |
494 | /* parent */ |
495 | /* why _exit? the child may have changed the stack, |
496 | * so "return 0" may do bad things */ |
497 | _exit(EXIT_SUCCESS); |
498 | } |
499 | /* Child */ |
500 | setsid(); /* detach from controlling tty */ |
501 | /* Redirect stdio to /dev/null, close extra FDs. |
502 | * We do not actually daemonize because of DAEMON_ONLY_SANITIZE */ |
503 | bb_daemonize_or_rexec(DAEMON_DEVNULL_STDIO |
504 | + DAEMON_CLOSE_EXTRA_FDS |
505 | + DAEMON_ONLY_SANITIZE, |
506 | NULL /* argv, unused */ ); |
507 | #endif |
508 | } |
509 | if (opt & OPT_MAKEPID) { |
510 | /* User wants _us_ to make the pidfile */ |
511 | write_pidfile(pidfile); |
512 | } |
513 | if (opt & OPT_c) { |
514 | struct bb_uidgid_t ugid = { -1, -1 }; |
515 | parse_chown_usergroup_or_die(&ugid, chuid); |
516 | if (ugid.uid != (uid_t) -1) { |
517 | struct passwd *pw = xgetpwuid(ugid.uid); |
518 | if (ugid.gid != (gid_t) -1) |
519 | pw->pw_gid = ugid.gid; |
520 | /* initgroups, setgid, setuid: */ |
521 | change_identity(pw); |
522 | } else if (ugid.gid != (gid_t) -1) { |
523 | xsetgid(ugid.gid); |
524 | setgroups(1, &ugid.gid); |
525 | } |
526 | } |
527 | #if ENABLE_FEATURE_START_STOP_DAEMON_FANCY |
528 | if (opt & OPT_NICELEVEL) { |
529 | /* Set process priority */ |
530 | int prio = getpriority(PRIO_PROCESS, 0) + xatoi_range(opt_N, INT_MIN/2, INT_MAX/2); |
531 | if (setpriority(PRIO_PROCESS, 0, prio) < 0) { |
532 | bb_perror_msg_and_die("setpriority(%d)", prio); |
533 | } |
534 | } |
535 | #endif |
536 | execvp(startas, argv); |
537 | bb_perror_msg_and_die("can't execute '%s'", startas); |
538 | } |
539 |