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/$PID/exe and /proc/$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
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!)
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)
55 -o,--oknodo Exit with status 0 if nothing is done
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"
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"
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"
85 //usage: "\n -s,--signal SIG Signal to send"
86 //usage: "\n -t,--test Match only, exit with 0 if a process is found"
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"
92 //usage: "\n -q,--quiet Quiet"
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"
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"
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"
120 //usage: "\n -q Quiet"
123 #include <sys/resource.h>
125 /* Override ENABLE_FEATURE_PIDFILE */
126 #define WANT_PIDFILE 1
130 struct pid_list
*next
;
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
152 #define QUIET (option_mask32 & OPT_QUIET)
153 #define TEST (option_mask32 & OPT_TEST)
156 struct pid_list
*found_procs
;
161 char *execname_cmpbuf
;
162 unsigned execname_sizeof
;
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 { \
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.
183 static int pid_is_exec(pid_t pid
)
186 char buf
[sizeof("/proc/%u/exe") + sizeof(int)*3];
188 sprintf(buf
, "/proc/%u/exe", (unsigned)pid
);
189 if (stat(buf
, &st
) < 0)
191 if (st
.st_dev
== execstat
.st_dev
192 && st
.st_ino
== execstat
.st_ino
)
198 static int pid_is_exec(pid_t pid
)
201 char buf
[sizeof("/proc/%u/cmdline") + sizeof(int)*3];
202 char *procname
, *exelink
;
205 procname
= buf
+ sprintf(buf
, "/proc/%u/exe", (unsigned)pid
) - 3;
207 exelink
= xmalloc_readlink(buf
);
208 match
= (exelink
&& strcmp(execname
, exelink
) == 0);
213 strcpy(procname
, "cmdline");
214 bytes
= open_read_close(buf
, G
.execname_cmpbuf
, G
.execname_sizeof
);
216 G
.execname_cmpbuf
[bytes
] = '\0';
217 return strcmp(execname
, G
.execname_cmpbuf
) == 0;
222 static int pid_is_name(pid_t pid
)
224 /* /proc/PID/stat is "PID (comm_15_bytes_max) ..." */
225 char buf
[32]; /* should be enough */
228 sprintf(buf
, "/proc/%u/stat", (unsigned)pid
);
229 if (open_read_close(buf
, buf
, sizeof(buf
) - 1) < 0)
231 buf
[sizeof(buf
) - 1] = '\0'; /* paranoia */
232 p
= strchr(buf
, '(');
235 pe
= strrchr(++p
, ')');
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 */
244 return strcmp(p
, cmdname
) == 0;
247 static int pid_is_user(int pid
)
250 char buf
[sizeof("/proc/") + sizeof(int)*3];
252 sprintf(buf
, "/proc/%u", (unsigned)pid
);
253 if (stat(buf
, &sb
) != 0)
255 return (sb
.st_uid
== (uid_t
)user_id
);
258 static void check(int pid
)
262 if (execname
&& !pid_is_exec(pid
)) {
265 if (cmdname
&& !pid_is_name(pid
)) {
268 if (userspec
&& !pid_is_user(pid
)) {
271 p
= xmalloc(sizeof(*p
));
272 p
->next
= G
.found_procs
;
277 static void do_pidfile(void)
282 f
= fopen_for_read(pidfile
);
284 if (fscanf(f
, "%u", &pid
) == 1)
287 } else if (errno
!= ENOENT
)
288 bb_perror_msg_and_die("open pidfile %s", pidfile
);
291 static void do_procinit(void)
294 struct dirent
*entry
;
302 procdir
= xopendir("/proc");
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 */
312 if (!entry
) /* EOF, no more entries */
314 pid
= bb_strtou(entry
->d_name
, NULL
, 10);
321 bb_error_msg_and_die("nothing in /proc - not mounted?");
324 static int do_stop(void)
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
);
341 bb_error_msg_and_die("internal error, please report");
344 if (!G
.found_procs
) {
346 printf("no %s found; none killed\n", what
);
350 for (p
= G
.found_procs
; p
; p
= p
->next
) {
351 if (kill(p
->pid
, TEST
? 0 : signal_nr
) == 0) {
354 bb_perror_msg("warning: killing process %u", (unsigned)p
->pid
);
357 /* Example: -K --test --pidfile PIDFILE detected
358 * that PIDFILE's pid doesn't exist */
364 if (!QUIET
&& killed
) {
365 printf("stopped %s (pid", what
);
366 for (p
= G
.found_procs
; p
; p
= p
->next
)
368 printf(" %u", (unsigned)p
->pid
);
372 if (ENABLE_FEATURE_CLEAN_UP
)
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"
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"
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
)
410 #ifdef OLDER_VERSION_OF_X
411 struct stat execstat
;
413 #if ENABLE_FEATURE_START_STOP_DAEMON_FANCY
414 // char *retry_arg = NULL;
421 #if ENABLE_FEATURE_START_STOP_DAEMON_LONG_OPTIONS
422 applet_long_options
= start_stop_daemon_longopts
;
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
)
441 signal_nr
= get_signum(signame
);
442 if (signal_nr
< 0) bb_show_usage();
447 if (!execname
) /* in case -a is given and -x is not */
450 G
.execname_sizeof
= strlen(execname
) + 1;
451 G
.execname_cmpbuf
= xmalloc(G
.execname_sizeof
+ 1);
454 // IF_FEATURE_START_STOP_DAEMON_FANCY(
456 // retries = xatoi_positive(retry_arg);
462 user_id
= bb_strtou(userspec
, NULL
, 10);
464 user_id
= xuname2uid(userspec
);
466 /* Both start and stop need to know current processes */
469 if (opt
& CTX_STOP
) {
471 return (opt
& OPT_OKNODO
) ? 0 : (i
<= 0);
476 printf("%s is already running\n%u\n", execname
, (unsigned)G
.found_procs
->pid
);
477 return !(opt
& OPT_OKNODO
);
480 #ifdef OLDER_VERSION_OF_X
482 xstat(execname
, &execstat
);
486 if (opt
& OPT_BACKGROUND
) {
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() */
492 pid_t pid
= xvfork();
495 /* why _exit? the child may have changed the stack,
496 * so "return 0" may do bad things */
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 */ );
509 if (opt
& OPT_MAKEPID
) {
510 /* User wants _us_ to make the pidfile */
511 write_pidfile(pidfile
);
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: */
522 } else if (ugid
.gid
!= (gid_t
) -1) {
524 setgroups(1, &ugid
.gid
);
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
);
536 execvp(startas
, argv
);
537 bb_perror_msg_and_die("can't execute '%s'", startas
);