Contents of /tags/mkinitrd-6_1_7/busybox/debianutils/start_stop_daemon.c
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Fri Oct 16 13:40:14 2009 UTC (14 years, 11 months ago) by niro
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Fri Oct 16 13:40:14 2009 UTC (14 years, 11 months ago) by niro
File MIME type: text/plain
File size: 12356 byte(s)
tagged 'mkinitrd-6_1_7'
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 tarball for details. |
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/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 | #include <sys/resource.h> |
60 | |
61 | /* Override ENABLE_FEATURE_PIDFILE */ |
62 | #define WANT_PIDFILE 1 |
63 | #include "libbb.h" |
64 | |
65 | struct pid_list { |
66 | struct pid_list *next; |
67 | pid_t pid; |
68 | }; |
69 | |
70 | 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 | |
91 | 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 | { |
120 | struct stat st; |
121 | char buf[sizeof("/proc//exe") + sizeof(int)*3]; |
122 | |
123 | 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 | } |
131 | #endif |
132 | |
133 | static int pid_is_exec(pid_t pid) |
134 | { |
135 | ssize_t bytes; |
136 | char buf[PATH_MAX]; |
137 | |
138 | 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 | |
147 | 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 | } |
171 | |
172 | static int pid_is_user(int pid) |
173 | { |
174 | struct stat sb; |
175 | char buf[sizeof("/proc/") + sizeof(int)*3]; |
176 | |
177 | sprintf(buf, "/proc/%u", (unsigned)pid); |
178 | if (stat(buf, &sb) != 0) |
179 | return 0; |
180 | return (sb.st_uid == (uid_t)user_id); |
181 | } |
182 | |
183 | static void check(int pid) |
184 | { |
185 | struct pid_list *p; |
186 | |
187 | if (execname && !pid_is_exec(pid)) { |
188 | return; |
189 | } |
190 | if (cmdname && !pid_is_name(pid)) { |
191 | return; |
192 | } |
193 | if (userspec && !pid_is_user(pid)) { |
194 | return; |
195 | } |
196 | p = xmalloc(sizeof(*p)); |
197 | p->next = found; |
198 | p->pid = pid; |
199 | found = p; |
200 | } |
201 | |
202 | static void do_pidfile(void) |
203 | { |
204 | FILE *f; |
205 | unsigned pid; |
206 | |
207 | f = fopen_for_read(pidfile); |
208 | 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 | int pid; |
221 | |
222 | if (pidfile) { |
223 | do_pidfile(); |
224 | return; |
225 | } |
226 | |
227 | procdir = xopendir("/proc"); |
228 | |
229 | 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 | pid = bb_strtou(entry->d_name, NULL, 10); |
240 | if (errno) /* NaN */ |
241 | continue; |
242 | check(pid); |
243 | } |
244 | closedir(procdir); |
245 | if (!pid) |
246 | bb_error_msg_and_die("nothing in /proc - not mounted?"); |
247 | } |
248 | |
249 | static int do_stop(void) |
250 | { |
251 | char *what; |
252 | struct pid_list *p; |
253 | int killed = 0; |
254 | |
255 | 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 | what = xasprintf("process in pidfile '%s'", pidfile); |
263 | } else if (userspec) { |
264 | what = xasprintf("process(es) owned by '%s'", userspec); |
265 | } else { |
266 | bb_error_msg_and_die("internal error, please report"); |
267 | } |
268 | |
269 | if (!found) { |
270 | if (!QUIET) |
271 | printf("no %s found; none killed\n", what); |
272 | killed = -1; |
273 | goto ret; |
274 | } |
275 | for (p = found; p; p = p->next) { |
276 | if (TEST || kill(p->pid, signal_nr) == 0) { |
277 | killed++; |
278 | } else { |
279 | p->pid = 0; |
280 | bb_perror_msg("warning: killing process %u", (unsigned)p->pid); |
281 | } |
282 | } |
283 | if (!QUIET && killed) { |
284 | printf("stopped %s (pid", what); |
285 | for (p = found; p; p = p->next) |
286 | if (p->pid) |
287 | printf(" %u", (unsigned)p->pid); |
288 | puts(")"); |
289 | } |
290 | ret: |
291 | if (ENABLE_FEATURE_CLEAN_UP) |
292 | free(what); |
293 | return killed; |
294 | } |
295 | |
296 | #if ENABLE_FEATURE_START_STOP_DAEMON_LONG_OPTIONS |
297 | 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 | #if ENABLE_FEATURE_START_STOP_DAEMON_FANCY |
305 | "oknodo\0" No_argument "o" |
306 | "verbose\0" No_argument "v" |
307 | "nicelevel\0" Required_argument "N" |
308 | #endif |
309 | "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 | #if ENABLE_FEATURE_START_STOP_DAEMON_FANCY |
317 | "retry\0" Required_argument "R" |
318 | #endif |
319 | ; |
320 | #endif |
321 | |
322 | 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 | { |
325 | unsigned opt; |
326 | char *signame; |
327 | char *startas; |
328 | char *chuid; |
329 | #ifdef OLDER_VERSION_OF_X |
330 | struct stat execstat; |
331 | #endif |
332 | #if ENABLE_FEATURE_START_STOP_DAEMON_FANCY |
333 | // char *retry_arg = NULL; |
334 | // int retries = -1; |
335 | char *opt_N; |
336 | #endif |
337 | |
338 | INIT_G(); |
339 | |
340 | #if ENABLE_FEATURE_START_STOP_DAEMON_LONG_OPTIONS |
341 | applet_long_options = start_stop_daemon_longopts; |
342 | #endif |
343 | |
344 | /* -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 | USE_FEATURE_START_STOP_DAEMON_FANCY(,&opt_N) |
355 | /* We accept and ignore -R <param> / --retry <param> */ |
356 | USE_FEATURE_START_STOP_DAEMON_FANCY(,NULL) |
357 | ); |
358 | |
359 | if (opt & OPT_s) { |
360 | signal_nr = get_signum(signame); |
361 | if (signal_nr < 0) bb_show_usage(); |
362 | } |
363 | |
364 | if (!(opt & OPT_a)) |
365 | startas = execname; |
366 | if (!execname) /* in case -a is given and -x is not */ |
367 | execname = startas; |
368 | |
369 | // USE_FEATURE_START_STOP_DAEMON_FANCY( |
370 | // if (retry_arg) |
371 | // retries = xatoi_u(retry_arg); |
372 | // ) |
373 | //argc -= optind; |
374 | argv += optind; |
375 | |
376 | if (userspec) { |
377 | user_id = bb_strtou(userspec, NULL, 10); |
378 | if (errno) |
379 | user_id = xuname2uid(userspec); |
380 | } |
381 | /* Both start and stop need to know current processes */ |
382 | do_procinit(); |
383 | |
384 | if (opt & CTX_STOP) { |
385 | int i = do_stop(); |
386 | return (opt & OPT_OKNODO) ? 0 : (i <= 0); |
387 | } |
388 | |
389 | if (found) { |
390 | if (!QUIET) |
391 | printf("%s is already running\n%u\n", execname, (unsigned)found->pid); |
392 | return !(opt & OPT_OKNODO); |
393 | } |
394 | |
395 | #ifdef OLDER_VERSION_OF_X |
396 | if (execname) |
397 | xstat(execname, &execstat); |
398 | #endif |
399 | |
400 | *--argv = startas; |
401 | if (opt & OPT_BACKGROUND) { |
402 | #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 | } |
426 | if (opt & OPT_MAKEPID) { |
427 | /* User wants _us_ to make the pidfile */ |
428 | write_pidfile(pidfile); |
429 | } |
430 | 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 | } |
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 | execvp(startas, argv); |
446 | bb_perror_msg_and_die("cannot start %s", startas); |
447 | } |