source: branches/3.2/mindi-busybox/debianutils/start_stop_daemon.c @ 3232

Last change on this file since 3232 was 3232, checked in by bruno, 5 years ago
  • Update mindi-busybox to 1.21.1
File size: 15.7 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/$PID/exe and /proc/$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
40Options 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
49Options 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
54Misc 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
129struct pid_list {
130    struct pid_list *next;
131    pid_t pid;
132};
133
134enum {
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
155struct 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 */
183static 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
198static 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
222static 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
247static 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
258static 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
277static 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
291static 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
324static 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
378static 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
403int start_stop_daemon_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
404int 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}
Note: See TracBrowser for help on using the repository browser.