Annotation of /trunk/mkinitrd-magellan/busybox/debianutils/start_stop_daemon.c
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Fri Apr 24 18:33:46 2009 UTC (15 years, 1 month ago) by niro
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Fri Apr 24 18:33:46 2009 UTC (15 years, 1 month ago) by niro
File MIME type: text/plain
File size: 12356 byte(s)
-updated to busybox-1.13.4
1 | niro | 532 | /* 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 tarball for details. | ||
9 | */ | ||
10 | |||
11 | niro | 816 | /* |
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/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 | ||
38 | |||
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!) | ||
47 | |||
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) | ||
52 | |||
53 | Misc options: | ||
54 | -o,--oknodo Exit with status 0 if nothing is done | ||
55 | -q,--quiet Quiet | ||
56 | -v,--verbose Verbose | ||
57 | */ | ||
58 | |||
59 | niro | 532 | #include <sys/resource.h> |
60 | |||
61 | niro | 816 | /* Override ENABLE_FEATURE_PIDFILE */ |
62 | #define WANT_PIDFILE 1 | ||
63 | #include "libbb.h" | ||
64 | niro | 532 | |
65 | struct pid_list { | ||
66 | struct pid_list *next; | ||
67 | pid_t pid; | ||
68 | }; | ||
69 | |||
70 | niro | 816 | enum { |
71 | CTX_STOP = (1 << 0), | ||
72 | CTX_START = (1 << 1), | ||
73 | OPT_BACKGROUND = (1 << 2), // -b | ||
74 | OPT_QUIET = (1 << 3), // -q | ||
75 | OPT_TEST = (1 << 4), // -t | ||
76 | OPT_MAKEPID = (1 << 5), // -m | ||
77 | OPT_a = (1 << 6), // -a | ||
78 | OPT_n = (1 << 7), // -n | ||
79 | OPT_s = (1 << 8), // -s | ||
80 | OPT_u = (1 << 9), // -u | ||
81 | OPT_c = (1 << 10), // -c | ||
82 | OPT_x = (1 << 11), // -x | ||
83 | OPT_p = (1 << 12), // -p | ||
84 | OPT_OKNODO = (1 << 13) * ENABLE_FEATURE_START_STOP_DAEMON_FANCY, // -o | ||
85 | OPT_VERBOSE = (1 << 14) * ENABLE_FEATURE_START_STOP_DAEMON_FANCY, // -v | ||
86 | OPT_NICELEVEL = (1 << 15) * ENABLE_FEATURE_START_STOP_DAEMON_FANCY, // -N | ||
87 | }; | ||
88 | #define QUIET (option_mask32 & OPT_QUIET) | ||
89 | #define TEST (option_mask32 & OPT_TEST) | ||
90 | niro | 532 | |
91 | niro | 816 | struct globals { |
92 | struct pid_list *found; | ||
93 | char *userspec; | ||
94 | char *cmdname; | ||
95 | char *execname; | ||
96 | char *pidfile; | ||
97 | int user_id; | ||
98 | smallint signal_nr; | ||
99 | }; | ||
100 | #define G (*(struct globals*)&bb_common_bufsiz1) | ||
101 | #define found (G.found ) | ||
102 | #define userspec (G.userspec ) | ||
103 | #define cmdname (G.cmdname ) | ||
104 | #define execname (G.execname ) | ||
105 | #define pidfile (G.pidfile ) | ||
106 | #define user_id (G.user_id ) | ||
107 | #define signal_nr (G.signal_nr ) | ||
108 | #define INIT_G() do { \ | ||
109 | user_id = -1; \ | ||
110 | signal_nr = 15; \ | ||
111 | } while (0) | ||
112 | |||
113 | #ifdef OLDER_VERSION_OF_X | ||
114 | /* -x,--exec EXECUTABLE | ||
115 | * Look for processes with matching /proc/$PID/exe. | ||
116 | * Match is performed using device+inode. | ||
117 | */ | ||
118 | static int pid_is_exec(pid_t pid) | ||
119 | niro | 532 | { |
120 | niro | 816 | struct stat st; |
121 | char buf[sizeof("/proc//exe") + sizeof(int)*3]; | ||
122 | niro | 532 | |
123 | niro | 816 | sprintf(buf, "/proc/%u/exe", (unsigned)pid); |
124 | if (stat(buf, &st) < 0) | ||
125 | return 0; | ||
126 | if (st.st_dev == execstat.st_dev | ||
127 | && st.st_ino == execstat.st_ino) | ||
128 | return 1; | ||
129 | return 0; | ||
130 | niro | 532 | } |
131 | niro | 816 | #endif |
132 | niro | 532 | |
133 | niro | 816 | static int pid_is_exec(pid_t pid) |
134 | niro | 532 | { |
135 | niro | 816 | ssize_t bytes; |
136 | char buf[PATH_MAX]; | ||
137 | niro | 532 | |
138 | niro | 816 | sprintf(buf, "/proc/%u/cmdline", (unsigned)pid); |
139 | bytes = open_read_close(buf, buf, sizeof(buf) - 1); | ||
140 | if (bytes > 0) { | ||
141 | buf[bytes] = '\0'; | ||
142 | return strcmp(buf, execname) == 0; | ||
143 | } | ||
144 | return 0; | ||
145 | } | ||
146 | niro | 532 | |
147 | niro | 816 | static int pid_is_name(pid_t pid) |
148 | { | ||
149 | /* /proc/PID/stat is "PID (comm_15_bytes_max) ..." */ | ||
150 | char buf[32]; /* should be enough */ | ||
151 | char *p, *pe; | ||
152 | |||
153 | sprintf(buf, "/proc/%u/stat", (unsigned)pid); | ||
154 | if (open_read_close(buf, buf, sizeof(buf) - 1) < 0) | ||
155 | return 0; | ||
156 | buf[sizeof(buf) - 1] = '\0'; /* paranoia */ | ||
157 | p = strchr(buf, '('); | ||
158 | if (!p) | ||
159 | return 0; | ||
160 | pe = strrchr(++p, ')'); | ||
161 | if (!pe) | ||
162 | return 0; | ||
163 | *pe = '\0'; | ||
164 | /* we require comm to match and to not be truncated */ | ||
165 | /* in Linux, if comm is 15 chars, it may be a truncated | ||
166 | * name, so we don't allow that to match */ | ||
167 | if (strlen(p) >= COMM_LEN - 1) /* COMM_LEN is 16 */ | ||
168 | return 0; | ||
169 | return strcmp(p, cmdname) == 0; | ||
170 | niro | 532 | } |
171 | |||
172 | niro | 816 | static int pid_is_user(int pid) |
173 | niro | 532 | { |
174 | struct stat sb; | ||
175 | char buf[sizeof("/proc/") + sizeof(int)*3]; | ||
176 | |||
177 | niro | 816 | sprintf(buf, "/proc/%u", (unsigned)pid); |
178 | niro | 532 | if (stat(buf, &sb) != 0) |
179 | return 0; | ||
180 | niro | 816 | return (sb.st_uid == (uid_t)user_id); |
181 | niro | 532 | } |
182 | |||
183 | niro | 816 | static void check(int pid) |
184 | niro | 532 | { |
185 | niro | 816 | struct pid_list *p; |
186 | niro | 532 | |
187 | niro | 816 | if (execname && !pid_is_exec(pid)) { |
188 | niro | 532 | return; |
189 | } | ||
190 | niro | 816 | if (cmdname && !pid_is_name(pid)) { |
191 | niro | 532 | return; |
192 | } | ||
193 | niro | 816 | if (userspec && !pid_is_user(pid)) { |
194 | niro | 532 | return; |
195 | } | ||
196 | niro | 816 | p = xmalloc(sizeof(*p)); |
197 | p->next = found; | ||
198 | p->pid = pid; | ||
199 | found = p; | ||
200 | niro | 532 | } |
201 | |||
202 | static void do_pidfile(void) | ||
203 | { | ||
204 | FILE *f; | ||
205 | niro | 816 | unsigned pid; |
206 | niro | 532 | |
207 | niro | 816 | f = fopen_for_read(pidfile); |
208 | niro | 532 | if (f) { |
209 | if (fscanf(f, "%u", &pid) == 1) | ||
210 | check(pid); | ||
211 | fclose(f); | ||
212 | } else if (errno != ENOENT) | ||
213 | bb_perror_msg_and_die("open pidfile %s", pidfile); | ||
214 | } | ||
215 | |||
216 | static void do_procinit(void) | ||
217 | { | ||
218 | DIR *procdir; | ||
219 | struct dirent *entry; | ||
220 | niro | 816 | int pid; |
221 | niro | 532 | |
222 | if (pidfile) { | ||
223 | do_pidfile(); | ||
224 | return; | ||
225 | } | ||
226 | |||
227 | procdir = xopendir("/proc"); | ||
228 | |||
229 | niro | 816 | pid = 0; |
230 | while (1) { | ||
231 | errno = 0; /* clear any previous error */ | ||
232 | entry = readdir(procdir); | ||
233 | // TODO: this check is too generic, it's better | ||
234 | // to check for exact errno(s) which mean that we got stale entry | ||
235 | if (errno) /* Stale entry, process has died after opendir */ | ||
236 | continue; | ||
237 | if (!entry) /* EOF, no more entries */ | ||
238 | break; | ||
239 | niro | 532 | pid = bb_strtou(entry->d_name, NULL, 10); |
240 | niro | 816 | if (errno) /* NaN */ |
241 | niro | 532 | continue; |
242 | check(pid); | ||
243 | } | ||
244 | closedir(procdir); | ||
245 | niro | 816 | if (!pid) |
246 | bb_error_msg_and_die("nothing in /proc - not mounted?"); | ||
247 | niro | 532 | } |
248 | |||
249 | static int do_stop(void) | ||
250 | { | ||
251 | char *what; | ||
252 | struct pid_list *p; | ||
253 | int killed = 0; | ||
254 | |||
255 | niro | 816 | if (cmdname) { |
256 | if (ENABLE_FEATURE_CLEAN_UP) what = xstrdup(cmdname); | ||
257 | if (!ENABLE_FEATURE_CLEAN_UP) what = cmdname; | ||
258 | } else if (execname) { | ||
259 | if (ENABLE_FEATURE_CLEAN_UP) what = xstrdup(execname); | ||
260 | if (!ENABLE_FEATURE_CLEAN_UP) what = execname; | ||
261 | } else if (pidfile) { | ||
262 | niro | 532 | what = xasprintf("process in pidfile '%s'", pidfile); |
263 | niro | 816 | } else if (userspec) { |
264 | niro | 532 | what = xasprintf("process(es) owned by '%s'", userspec); |
265 | niro | 816 | } else { |
266 | niro | 532 | bb_error_msg_and_die("internal error, please report"); |
267 | niro | 816 | } |
268 | niro | 532 | |
269 | if (!found) { | ||
270 | niro | 816 | if (!QUIET) |
271 | niro | 532 | printf("no %s found; none killed\n", what); |
272 | niro | 816 | killed = -1; |
273 | goto ret; | ||
274 | niro | 532 | } |
275 | for (p = found; p; p = p->next) { | ||
276 | niro | 816 | if (TEST || kill(p->pid, signal_nr) == 0) { |
277 | niro | 532 | killed++; |
278 | } else { | ||
279 | niro | 816 | p->pid = 0; |
280 | bb_perror_msg("warning: killing process %u", (unsigned)p->pid); | ||
281 | niro | 532 | } |
282 | } | ||
283 | niro | 816 | if (!QUIET && killed) { |
284 | niro | 532 | printf("stopped %s (pid", what); |
285 | for (p = found; p; p = p->next) | ||
286 | niro | 816 | if (p->pid) |
287 | printf(" %u", (unsigned)p->pid); | ||
288 | niro | 532 | puts(")"); |
289 | } | ||
290 | niro | 816 | ret: |
291 | niro | 532 | if (ENABLE_FEATURE_CLEAN_UP) |
292 | free(what); | ||
293 | return killed; | ||
294 | } | ||
295 | |||
296 | #if ENABLE_FEATURE_START_STOP_DAEMON_LONG_OPTIONS | ||
297 | niro | 816 | static const char start_stop_daemon_longopts[] ALIGN1 = |
298 | "stop\0" No_argument "K" | ||
299 | "start\0" No_argument "S" | ||
300 | "background\0" No_argument "b" | ||
301 | "quiet\0" No_argument "q" | ||
302 | "test\0" No_argument "t" | ||
303 | "make-pidfile\0" No_argument "m" | ||
304 | niro | 532 | #if ENABLE_FEATURE_START_STOP_DAEMON_FANCY |
305 | niro | 816 | "oknodo\0" No_argument "o" |
306 | "verbose\0" No_argument "v" | ||
307 | "nicelevel\0" Required_argument "N" | ||
308 | niro | 532 | #endif |
309 | niro | 816 | "startas\0" Required_argument "a" |
310 | "name\0" Required_argument "n" | ||
311 | "signal\0" Required_argument "s" | ||
312 | "user\0" Required_argument "u" | ||
313 | "chuid\0" Required_argument "c" | ||
314 | "exec\0" Required_argument "x" | ||
315 | "pidfile\0" Required_argument "p" | ||
316 | niro | 532 | #if ENABLE_FEATURE_START_STOP_DAEMON_FANCY |
317 | niro | 816 | "retry\0" Required_argument "R" |
318 | niro | 532 | #endif |
319 | niro | 816 | ; |
320 | niro | 532 | #endif |
321 | |||
322 | niro | 816 | int start_stop_daemon_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; |
323 | int start_stop_daemon_main(int argc UNUSED_PARAM, char **argv) | ||
324 | niro | 532 | { |
325 | unsigned opt; | ||
326 | niro | 816 | char *signame; |
327 | char *startas; | ||
328 | char *chuid; | ||
329 | #ifdef OLDER_VERSION_OF_X | ||
330 | struct stat execstat; | ||
331 | #endif | ||
332 | niro | 532 | #if ENABLE_FEATURE_START_STOP_DAEMON_FANCY |
333 | // char *retry_arg = NULL; | ||
334 | // int retries = -1; | ||
335 | char *opt_N; | ||
336 | #endif | ||
337 | niro | 816 | |
338 | INIT_G(); | ||
339 | |||
340 | niro | 532 | #if ENABLE_FEATURE_START_STOP_DAEMON_LONG_OPTIONS |
341 | niro | 816 | applet_long_options = start_stop_daemon_longopts; |
342 | niro | 532 | #endif |
343 | |||
344 | niro | 816 | /* -K or -S is required; they are mutually exclusive */ |
345 | /* -p is required if -m is given */ | ||
346 | /* -xpun (at least one) is required if -K is given */ | ||
347 | /* -xa (at least one) is required if -S is given */ | ||
348 | /* -q turns off -v */ | ||
349 | opt_complementary = "K:S:K--S:S--K:m?p:K?xpun:S?xa" | ||
350 | USE_FEATURE_START_STOP_DAEMON_FANCY("q-v"); | ||
351 | opt = getopt32(argv, "KSbqtma:n:s:u:c:x:p:" | ||
352 | USE_FEATURE_START_STOP_DAEMON_FANCY("ovN:R:"), | ||
353 | &startas, &cmdname, &signame, &userspec, &chuid, &execname, &pidfile | ||
354 | niro | 532 | USE_FEATURE_START_STOP_DAEMON_FANCY(,&opt_N) |
355 | niro | 816 | /* We accept and ignore -R <param> / --retry <param> */ |
356 | USE_FEATURE_START_STOP_DAEMON_FANCY(,NULL) | ||
357 | ); | ||
358 | niro | 532 | |
359 | niro | 816 | if (opt & OPT_s) { |
360 | niro | 532 | signal_nr = get_signum(signame); |
361 | if (signal_nr < 0) bb_show_usage(); | ||
362 | } | ||
363 | |||
364 | niro | 816 | if (!(opt & OPT_a)) |
365 | niro | 532 | startas = execname; |
366 | niro | 816 | if (!execname) /* in case -a is given and -x is not */ |
367 | execname = startas; | ||
368 | niro | 532 | |
369 | // USE_FEATURE_START_STOP_DAEMON_FANCY( | ||
370 | // if (retry_arg) | ||
371 | // retries = xatoi_u(retry_arg); | ||
372 | // ) | ||
373 | niro | 816 | //argc -= optind; |
374 | niro | 532 | argv += optind; |
375 | |||
376 | if (userspec) { | ||
377 | user_id = bb_strtou(userspec, NULL, 10); | ||
378 | if (errno) | ||
379 | user_id = xuname2uid(userspec); | ||
380 | } | ||
381 | niro | 816 | /* Both start and stop need to know current processes */ |
382 | do_procinit(); | ||
383 | niro | 532 | |
384 | if (opt & CTX_STOP) { | ||
385 | int i = do_stop(); | ||
386 | niro | 816 | return (opt & OPT_OKNODO) ? 0 : (i <= 0); |
387 | niro | 532 | } |
388 | |||
389 | if (found) { | ||
390 | niro | 816 | if (!QUIET) |
391 | printf("%s is already running\n%u\n", execname, (unsigned)found->pid); | ||
392 | niro | 532 | return !(opt & OPT_OKNODO); |
393 | } | ||
394 | niro | 816 | |
395 | #ifdef OLDER_VERSION_OF_X | ||
396 | if (execname) | ||
397 | xstat(execname, &execstat); | ||
398 | #endif | ||
399 | |||
400 | niro | 532 | *--argv = startas; |
401 | if (opt & OPT_BACKGROUND) { | ||
402 | niro | 816 | #if BB_MMU |
403 | bb_daemonize(DAEMON_DEVNULL_STDIO + DAEMON_CLOSE_EXTRA_FDS); | ||
404 | /* DAEMON_DEVNULL_STDIO is superfluous - | ||
405 | * it's always done by bb_daemonize() */ | ||
406 | #else | ||
407 | pid_t pid = vfork(); | ||
408 | if (pid < 0) /* error */ | ||
409 | bb_perror_msg_and_die("vfork"); | ||
410 | if (pid != 0) { | ||
411 | /* parent */ | ||
412 | /* why _exit? the child may have changed the stack, | ||
413 | * so "return 0" may do bad things */ | ||
414 | _exit(EXIT_SUCCESS); | ||
415 | } | ||
416 | /* Child */ | ||
417 | setsid(); /* detach from controlling tty */ | ||
418 | /* Redirect stdio to /dev/null, close extra FDs. | ||
419 | * We do not actually daemonize because of DAEMON_ONLY_SANITIZE */ | ||
420 | bb_daemonize_or_rexec(DAEMON_DEVNULL_STDIO | ||
421 | + DAEMON_CLOSE_EXTRA_FDS | ||
422 | + DAEMON_ONLY_SANITIZE, | ||
423 | NULL /* argv, unused */ ); | ||
424 | #endif | ||
425 | niro | 532 | } |
426 | if (opt & OPT_MAKEPID) { | ||
427 | niro | 816 | /* User wants _us_ to make the pidfile */ |
428 | write_pidfile(pidfile); | ||
429 | niro | 532 | } |
430 | niro | 816 | if (opt & OPT_c) { |
431 | struct bb_uidgid_t ugid = { -1, -1 }; | ||
432 | parse_chown_usergroup_or_die(&ugid, chuid); | ||
433 | if (ugid.gid != (gid_t) -1) xsetgid(ugid.gid); | ||
434 | if (ugid.uid != (uid_t) -1) xsetuid(ugid.uid); | ||
435 | niro | 532 | } |
436 | #if ENABLE_FEATURE_START_STOP_DAEMON_FANCY | ||
437 | if (opt & OPT_NICELEVEL) { | ||
438 | /* Set process priority */ | ||
439 | int prio = getpriority(PRIO_PROCESS, 0) + xatoi_range(opt_N, INT_MIN/2, INT_MAX/2); | ||
440 | if (setpriority(PRIO_PROCESS, 0, prio) < 0) { | ||
441 | bb_perror_msg_and_die("setpriority(%d)", prio); | ||
442 | } | ||
443 | } | ||
444 | #endif | ||
445 | niro | 816 | execvp(startas, argv); |
446 | niro | 532 | bb_perror_msg_and_die("cannot start %s", startas); |
447 | } |