source: MondoRescue/branches/3.2/mindi-busybox/debianutils/start_stop_daemon.c@ 3186

Last change on this file since 3186 was 2725, checked in by Bruno Cornec, 13 years ago
  • Update mindi-busybox to 1.18.3 to avoid problems with the tar command which is now failing on recent versions with busybox 1.7.3
File size: 12.3 KB
Line 
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/*
12This is how it is supposed to work:
13
14start-stop-daemon [OPTIONS] [--start|--stop] [[--] arguments...]
15
16One (only) of these must be given:
17 -S,--start Start
18 -K,--stop Stop
19
20Search for matching processes.
21If --stop is given, stop all matching processes (by sending a signal).
22If --start is given, start a new process unless a matching process was found.
23
24Options 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/$PID/stat.
29 Only basename is compared:
30 "ntpd" == "./ntpd" == "/path/to/ntpd".
31[TODO: can PROCESS_NAME be a full pathname? Should we require full match then
32with /proc/$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
39Options 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
48Options 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
53Misc 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
65struct pid_list {
66 struct pid_list *next;
67 pid_t pid;
68};
69
70enum {
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
91struct globals {
92 struct pid_list *found_procs;
93 char *userspec;
94 char *cmdname;
95 char *execname;
96 char *pidfile;
97 char *execname_cmpbuf;
98 unsigned execname_sizeof;
99 int user_id;
100 smallint signal_nr;
101} FIX_ALIASING;
102#define G (*(struct globals*)&bb_common_bufsiz1)
103#define userspec (G.userspec )
104#define cmdname (G.cmdname )
105#define execname (G.execname )
106#define pidfile (G.pidfile )
107#define user_id (G.user_id )
108#define signal_nr (G.signal_nr )
109#define INIT_G() do { \
110 user_id = -1; \
111 signal_nr = 15; \
112} while (0)
113
114#ifdef OLDER_VERSION_OF_X
115/* -x,--exec EXECUTABLE
116 * Look for processes with matching /proc/$PID/exe.
117 * Match is performed using device+inode.
118 */
119static int pid_is_exec(pid_t pid)
120{
121 struct stat st;
122 char buf[sizeof("/proc/%u/exe") + sizeof(int)*3];
123
124 sprintf(buf, "/proc/%u/exe", (unsigned)pid);
125 if (stat(buf, &st) < 0)
126 return 0;
127 if (st.st_dev == execstat.st_dev
128 && st.st_ino == execstat.st_ino)
129 return 1;
130 return 0;
131}
132#endif
133
134static int pid_is_exec(pid_t pid)
135{
136 ssize_t bytes;
137 char buf[sizeof("/proc/%u/cmdline") + sizeof(int)*3];
138
139 sprintf(buf, "/proc/%u/cmdline", (unsigned)pid);
140 bytes = open_read_close(buf, G.execname_cmpbuf, G.execname_sizeof);
141 if (bytes > 0) {
142 G.execname_cmpbuf[bytes] = '\0';
143 return strcmp(execname, G.execname_cmpbuf) == 0;
144 }
145 return 0;
146}
147
148static int pid_is_name(pid_t pid)
149{
150 /* /proc/PID/stat is "PID (comm_15_bytes_max) ..." */
151 char buf[32]; /* should be enough */
152 char *p, *pe;
153
154 sprintf(buf, "/proc/%u/stat", (unsigned)pid);
155 if (open_read_close(buf, buf, sizeof(buf) - 1) < 0)
156 return 0;
157 buf[sizeof(buf) - 1] = '\0'; /* paranoia */
158 p = strchr(buf, '(');
159 if (!p)
160 return 0;
161 pe = strrchr(++p, ')');
162 if (!pe)
163 return 0;
164 *pe = '\0';
165 /* we require comm to match and to not be truncated */
166 /* in Linux, if comm is 15 chars, it may be a truncated
167 * name, so we don't allow that to match */
168 if (strlen(p) >= COMM_LEN - 1) /* COMM_LEN is 16 */
169 return 0;
170 return strcmp(p, cmdname) == 0;
171}
172
173static int pid_is_user(int pid)
174{
175 struct stat sb;
176 char buf[sizeof("/proc/") + sizeof(int)*3];
177
178 sprintf(buf, "/proc/%u", (unsigned)pid);
179 if (stat(buf, &sb) != 0)
180 return 0;
181 return (sb.st_uid == (uid_t)user_id);
182}
183
184static void check(int pid)
185{
186 struct pid_list *p;
187
188 if (execname && !pid_is_exec(pid)) {
189 return;
190 }
191 if (cmdname && !pid_is_name(pid)) {
192 return;
193 }
194 if (userspec && !pid_is_user(pid)) {
195 return;
196 }
197 p = xmalloc(sizeof(*p));
198 p->next = G.found_procs;
199 p->pid = pid;
200 G.found_procs = p;
201}
202
203static void do_pidfile(void)
204{
205 FILE *f;
206 unsigned pid;
207
208 f = fopen_for_read(pidfile);
209 if (f) {
210 if (fscanf(f, "%u", &pid) == 1)
211 check(pid);
212 fclose(f);
213 } else if (errno != ENOENT)
214 bb_perror_msg_and_die("open pidfile %s", pidfile);
215}
216
217static void do_procinit(void)
218{
219 DIR *procdir;
220 struct dirent *entry;
221 int pid;
222
223 if (pidfile) {
224 do_pidfile();
225 return;
226 }
227
228 procdir = xopendir("/proc");
229
230 pid = 0;
231 while (1) {
232 errno = 0; /* clear any previous error */
233 entry = readdir(procdir);
234// TODO: this check is too generic, it's better
235// to check for exact errno(s) which mean that we got stale entry
236 if (errno) /* Stale entry, process has died after opendir */
237 continue;
238 if (!entry) /* EOF, no more entries */
239 break;
240 pid = bb_strtou(entry->d_name, NULL, 10);
241 if (errno) /* NaN */
242 continue;
243 check(pid);
244 }
245 closedir(procdir);
246 if (!pid)
247 bb_error_msg_and_die("nothing in /proc - not mounted?");
248}
249
250static int do_stop(void)
251{
252 char *what;
253 struct pid_list *p;
254 int killed = 0;
255
256 if (cmdname) {
257 if (ENABLE_FEATURE_CLEAN_UP) what = xstrdup(cmdname);
258 if (!ENABLE_FEATURE_CLEAN_UP) what = cmdname;
259 } else if (execname) {
260 if (ENABLE_FEATURE_CLEAN_UP) what = xstrdup(execname);
261 if (!ENABLE_FEATURE_CLEAN_UP) what = execname;
262 } else if (pidfile) {
263 what = xasprintf("process in pidfile '%s'", pidfile);
264 } else if (userspec) {
265 what = xasprintf("process(es) owned by '%s'", userspec);
266 } else {
267 bb_error_msg_and_die("internal error, please report");
268 }
269
270 if (!G.found_procs) {
271 if (!QUIET)
272 printf("no %s found; none killed\n", what);
273 killed = -1;
274 goto ret;
275 }
276 for (p = G.found_procs; p; p = p->next) {
277 if (TEST || kill(p->pid, signal_nr) == 0) {
278 killed++;
279 } else {
280 p->pid = 0;
281 bb_perror_msg("warning: killing process %u", (unsigned)p->pid);
282 }
283 }
284 if (!QUIET && killed) {
285 printf("stopped %s (pid", what);
286 for (p = G.found_procs; p; p = p->next)
287 if (p->pid)
288 printf(" %u", (unsigned)p->pid);
289 puts(")");
290 }
291 ret:
292 if (ENABLE_FEATURE_CLEAN_UP)
293 free(what);
294 return killed;
295}
296
297#if ENABLE_FEATURE_START_STOP_DAEMON_LONG_OPTIONS
298static const char start_stop_daemon_longopts[] ALIGN1 =
299 "stop\0" No_argument "K"
300 "start\0" No_argument "S"
301 "background\0" No_argument "b"
302 "quiet\0" No_argument "q"
303 "test\0" No_argument "t"
304 "make-pidfile\0" No_argument "m"
305#if ENABLE_FEATURE_START_STOP_DAEMON_FANCY
306 "oknodo\0" No_argument "o"
307 "verbose\0" No_argument "v"
308 "nicelevel\0" Required_argument "N"
309#endif
310 "startas\0" Required_argument "a"
311 "name\0" Required_argument "n"
312 "signal\0" Required_argument "s"
313 "user\0" Required_argument "u"
314 "chuid\0" Required_argument "c"
315 "exec\0" Required_argument "x"
316 "pidfile\0" Required_argument "p"
317#if ENABLE_FEATURE_START_STOP_DAEMON_FANCY
318 "retry\0" Required_argument "R"
319#endif
320 ;
321#endif
322
323int start_stop_daemon_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
324int start_stop_daemon_main(int argc UNUSED_PARAM, char **argv)
325{
326 unsigned opt;
327 char *signame;
328 char *startas;
329 char *chuid;
330#ifdef OLDER_VERSION_OF_X
331 struct stat execstat;
332#endif
333#if ENABLE_FEATURE_START_STOP_DAEMON_FANCY
334// char *retry_arg = NULL;
335// int retries = -1;
336 char *opt_N;
337#endif
338
339 INIT_G();
340
341#if ENABLE_FEATURE_START_STOP_DAEMON_LONG_OPTIONS
342 applet_long_options = start_stop_daemon_longopts;
343#endif
344
345 /* -K or -S is required; they are mutually exclusive */
346 /* -p is required if -m is given */
347 /* -xpun (at least one) is required if -K is given */
348 /* -xa (at least one) is required if -S is given */
349 /* -q turns off -v */
350 opt_complementary = "K:S:K--S:S--K:m?p:K?xpun:S?xa"
351 IF_FEATURE_START_STOP_DAEMON_FANCY("q-v");
352 opt = getopt32(argv, "KSbqtma:n:s:u:c:x:p:"
353 IF_FEATURE_START_STOP_DAEMON_FANCY("ovN:R:"),
354 &startas, &cmdname, &signame, &userspec, &chuid, &execname, &pidfile
355 IF_FEATURE_START_STOP_DAEMON_FANCY(,&opt_N)
356 /* We accept and ignore -R <param> / --retry <param> */
357 IF_FEATURE_START_STOP_DAEMON_FANCY(,NULL)
358 );
359
360 if (opt & OPT_s) {
361 signal_nr = get_signum(signame);
362 if (signal_nr < 0) bb_show_usage();
363 }
364
365 if (!(opt & OPT_a))
366 startas = execname;
367 if (!execname) /* in case -a is given and -x is not */
368 execname = startas;
369 if (execname) {
370 G.execname_sizeof = strlen(execname) + 1;
371 G.execname_cmpbuf = xmalloc(G.execname_sizeof + 1);
372 }
373
374// IF_FEATURE_START_STOP_DAEMON_FANCY(
375// if (retry_arg)
376// retries = xatoi_positive(retry_arg);
377// )
378 //argc -= optind;
379 argv += optind;
380
381 if (userspec) {
382 user_id = bb_strtou(userspec, NULL, 10);
383 if (errno)
384 user_id = xuname2uid(userspec);
385 }
386 /* Both start and stop need to know current processes */
387 do_procinit();
388
389 if (opt & CTX_STOP) {
390 int i = do_stop();
391 return (opt & OPT_OKNODO) ? 0 : (i <= 0);
392 }
393
394 if (G.found_procs) {
395 if (!QUIET)
396 printf("%s is already running\n%u\n", execname, (unsigned)G.found_procs->pid);
397 return !(opt & OPT_OKNODO);
398 }
399
400#ifdef OLDER_VERSION_OF_X
401 if (execname)
402 xstat(execname, &execstat);
403#endif
404
405 *--argv = startas;
406 if (opt & OPT_BACKGROUND) {
407#if BB_MMU
408 bb_daemonize(DAEMON_DEVNULL_STDIO + DAEMON_CLOSE_EXTRA_FDS);
409 /* DAEMON_DEVNULL_STDIO is superfluous -
410 * it's always done by bb_daemonize() */
411#else
412 pid_t pid = xvfork();
413 if (pid != 0) {
414 /* parent */
415 /* why _exit? the child may have changed the stack,
416 * so "return 0" may do bad things */
417 _exit(EXIT_SUCCESS);
418 }
419 /* Child */
420 setsid(); /* detach from controlling tty */
421 /* Redirect stdio to /dev/null, close extra FDs.
422 * We do not actually daemonize because of DAEMON_ONLY_SANITIZE */
423 bb_daemonize_or_rexec(DAEMON_DEVNULL_STDIO
424 + DAEMON_CLOSE_EXTRA_FDS
425 + DAEMON_ONLY_SANITIZE,
426 NULL /* argv, unused */ );
427#endif
428 }
429 if (opt & OPT_MAKEPID) {
430 /* User wants _us_ to make the pidfile */
431 write_pidfile(pidfile);
432 }
433 if (opt & OPT_c) {
434 struct bb_uidgid_t ugid = { -1, -1 };
435 parse_chown_usergroup_or_die(&ugid, chuid);
436 if (ugid.gid != (gid_t) -1) xsetgid(ugid.gid);
437 if (ugid.uid != (uid_t) -1) xsetuid(ugid.uid);
438 }
439#if ENABLE_FEATURE_START_STOP_DAEMON_FANCY
440 if (opt & OPT_NICELEVEL) {
441 /* Set process priority */
442 int prio = getpriority(PRIO_PROCESS, 0) + xatoi_range(opt_N, INT_MIN/2, INT_MAX/2);
443 if (setpriority(PRIO_PROCESS, 0, prio) < 0) {
444 bb_perror_msg_and_die("setpriority(%d)", prio);
445 }
446 }
447#endif
448 execvp(startas, argv);
449 bb_perror_msg_and_die("can't execute '%s'", startas);
450}
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