source: MondoRescue/branches/2.2.5/mindi-busybox/debianutils/start_stop_daemon.c

Last change on this file was 1765, checked in by Bruno Cornec, 16 years ago

Update to busybox 1.7.2
File size: 7.9 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 tarball for details.
9 */
10
11/* NB: we have a problem here with /proc/NN/exe usage, similar to
12 * one fixed in killall/pidof */
13
14#include <getopt.h>
15#include <sys/resource.h>
16
17/* Override ENABLE_FEATURE_PIDFILE */
18#define WANT_PIDFILE 1
19#include "libbb.h"
20
21static int signal_nr = 15;
22static int user_id = -1;
23static char *userspec;
24static char *cmdname;
25static char *execname;
26static char *pidfile;
27static smallint quiet;
28
29struct pid_list {
30 struct pid_list *next;
31 pid_t pid;
32};
33
34static struct pid_list *found;
35
36static int pid_is_exec(pid_t pid, const char *name)
37{
38 char buf[sizeof("/proc//exe") + sizeof(int)*3];
39 char *execbuf;
40 int n;
41
42 sprintf(buf, "/proc/%u/exe", pid);
43 n = strlen(name) + 1;
44 execbuf = xzalloc(n + 1);
45 readlink(buf, execbuf, n);
46
47 /* if readlink fails, execbuf still contains "" */
48 n = strcmp(execbuf, name);
49 if (ENABLE_FEATURE_CLEAN_UP)
50 free(execbuf);
51 return !n; /* nonzero (true) if execbuf == name */
52}
53
54static int pid_is_user(int pid, int uid)
55{
56 struct stat sb;
57 char buf[sizeof("/proc/") + sizeof(int)*3];
58
59 sprintf(buf, "/proc/%u", pid);
60 if (stat(buf, &sb) != 0)
61 return 0;
62 return (sb.st_uid == uid);
63}
64
65static int pid_is_cmd(pid_t pid, const char *name)
66{
67 char fname[sizeof("/proc//stat") + sizeof(int)*3];
68 char *buf;
69 int r = 0;
70
71 sprintf(fname, "/proc/%u/stat", pid);
72 buf = xmalloc_open_read_close(fname, NULL);
73 if (buf) {
74 char *p = strchr(buf, '(');
75 if (p) {
76 char *pe = strrchr(++p, ')');
77 if (pe) {
78 *pe = '\0';
79 r = !strcmp(p, name);
80 }
81 }
82 free(buf);
83 }
84 return r;
85}
86
87static void check(int pid)
88{
89 struct pid_list *p;
90
91 if (execname && !pid_is_exec(pid, execname)) {
92 return;
93 }
94 if (userspec && !pid_is_user(pid, user_id)) {
95 return;
96 }
97 if (cmdname && !pid_is_cmd(pid, cmdname)) {
98 return;
99 }
100 p = xmalloc(sizeof(*p));
101 p->next = found;
102 p->pid = pid;
103 found = p;
104}
105
106static void do_pidfile(void)
107{
108 FILE *f;
109 unsigned pid;
110
111 f = fopen(pidfile, "r");
112 if (f) {
113 if (fscanf(f, "%u", &pid) == 1)
114 check(pid);
115 fclose(f);
116 } else if (errno != ENOENT)
117 bb_perror_msg_and_die("open pidfile %s", pidfile);
118}
119
120static void do_procinit(void)
121{
122 DIR *procdir;
123 struct dirent *entry;
124 int foundany, pid;
125
126 if (pidfile) {
127 do_pidfile();
128 return;
129 }
130
131 procdir = xopendir("/proc");
132
133 foundany = 0;
134 while ((entry = readdir(procdir)) != NULL) {
135 pid = bb_strtou(entry->d_name, NULL, 10);
136 if (errno)
137 continue;
138 foundany++;
139 check(pid);
140 }
141 closedir(procdir);
142 if (!foundany)
143 bb_error_msg_and_die("nothing in /proc - not mounted?");
144}
145
146static int do_stop(void)
147{
148 char *what;
149 struct pid_list *p;
150 int killed = 0;
151
152 do_procinit();
153
154 if (cmdname) {
155 if (ENABLE_FEATURE_CLEAN_UP) what = xstrdup(cmdname);
156 if (!ENABLE_FEATURE_CLEAN_UP) what = cmdname;
157 } else if (execname) {
158 if (ENABLE_FEATURE_CLEAN_UP) what = xstrdup(execname);
159 if (!ENABLE_FEATURE_CLEAN_UP) what = execname;
160 } else if (pidfile)
161 what = xasprintf("process in pidfile '%s'", pidfile);
162 else if (userspec)
163 what = xasprintf("process(es) owned by '%s'", userspec);
164 else
165 bb_error_msg_and_die("internal error, please report");
166
167 if (!found) {
168 if (!quiet)
169 printf("no %s found; none killed\n", what);
170 killed = -1;
171 goto ret;
172 }
173 for (p = found; p; p = p->next) {
174 if (kill(p->pid, signal_nr) == 0) {
175 p->pid = - p->pid;
176 killed++;
177 } else {
178 bb_perror_msg("warning: killing process %u", p->pid);
179 }
180 }
181 if (!quiet && killed) {
182 printf("stopped %s (pid", what);
183 for (p = found; p; p = p->next)
184 if (p->pid < 0)
185 printf(" %u", - p->pid);
186 puts(")");
187 }
188 ret:
189 if (ENABLE_FEATURE_CLEAN_UP)
190 free(what);
191 return killed;
192}
193
194#if ENABLE_FEATURE_START_STOP_DAEMON_LONG_OPTIONS
195static const char start_stop_daemon_longopts[] ALIGN1 =
196 "stop\0" No_argument "K"
197 "start\0" No_argument "S"
198 "background\0" No_argument "b"
199 "quiet\0" No_argument "q"
200 "make-pidfile\0" No_argument "m"
201#if ENABLE_FEATURE_START_STOP_DAEMON_FANCY
202 "oknodo\0" No_argument "o"
203 "verbose\0" No_argument "v"
204 "nicelevel\0" Required_argument "N"
205#endif
206 "startas\0" Required_argument "a"
207 "name\0" Required_argument "n"
208 "signal\0" Required_argument "s"
209 "user\0" Required_argument "u"
210 "chuid\0" Required_argument "c"
211 "exec\0" Required_argument "x"
212 "pidfile\0" Required_argument "p"
213#if ENABLE_FEATURE_START_STOP_DAEMON_FANCY
214 "retry\0" Required_argument "R"
215#endif
216 ;
217#endif
218
219enum {
220 CTX_STOP = 0x1,
221 CTX_START = 0x2,
222 OPT_BACKGROUND = 0x4, // -b
223 OPT_QUIET = 0x8, // -q
224 OPT_MAKEPID = 0x10, // -m
225 OPT_a = 0x20, // -a
226 OPT_n = 0x40, // -n
227 OPT_s = 0x80, // -s
228 OPT_u = 0x100, // -u
229 OPT_c = 0x200, // -c
230 OPT_x = 0x400, // -x
231 OPT_p = 0x800, // -p
232 OPT_OKNODO = 0x1000 * ENABLE_FEATURE_START_STOP_DAEMON_FANCY, // -o
233 OPT_VERBOSE = 0x2000 * ENABLE_FEATURE_START_STOP_DAEMON_FANCY, // -v
234 OPT_NICELEVEL = 0x4000 * ENABLE_FEATURE_START_STOP_DAEMON_FANCY, // -N
235};
236
237int start_stop_daemon_main(int argc, char **argv);
238int start_stop_daemon_main(int argc, char **argv)
239{
240 unsigned opt;
241 char *signame;
242 char *startas;
243 char *chuid;
244#if ENABLE_FEATURE_START_STOP_DAEMON_FANCY
245// char *retry_arg = NULL;
246// int retries = -1;
247 char *opt_N;
248#endif
249#if ENABLE_FEATURE_START_STOP_DAEMON_LONG_OPTIONS
250 applet_long_options = start_stop_daemon_longopts;
251#endif
252
253 /* Check required one context option was given */
254 opt_complementary = "K:S:K--S:S--K:m?p:K?xpun:S?xa";
255 opt = getopt32(argv, "KSbqma:n:s:u:c:x:p:"
256 USE_FEATURE_START_STOP_DAEMON_FANCY("ovN:"),
257// USE_FEATURE_START_STOP_DAEMON_FANCY("ovN:R:"),
258 &startas, &cmdname, &signame, &userspec, &chuid, &execname, &pidfile
259 USE_FEATURE_START_STOP_DAEMON_FANCY(,&opt_N)
260// USE_FEATURE_START_STOP_DAEMON_FANCY(,&retry_arg)
261 );
262
263 quiet = (opt & OPT_QUIET) && !(opt & OPT_VERBOSE);
264
265 if (opt & OPT_s) {
266 signal_nr = get_signum(signame);
267 if (signal_nr < 0) bb_show_usage();
268 }
269
270 if (!(opt & OPT_a))
271 startas = execname;
272
273// USE_FEATURE_START_STOP_DAEMON_FANCY(
274// if (retry_arg)
275// retries = xatoi_u(retry_arg);
276// )
277 argc -= optind;
278 argv += optind;
279
280 if (userspec) {
281 user_id = bb_strtou(userspec, NULL, 10);
282 if (errno)
283 user_id = xuname2uid(userspec);
284 }
285
286 if (opt & CTX_STOP) {
287 int i = do_stop();
288 return (opt & OPT_OKNODO) ? 0 : (i <= 0);
289 }
290
291 do_procinit();
292
293 if (found) {
294 if (!quiet)
295 printf("%s already running\n%d\n", execname, found->pid);
296 return !(opt & OPT_OKNODO);
297 }
298 *--argv = startas;
299 if (opt & OPT_BACKGROUND) {
300#if BB_MMU
301 bb_daemonize(0);
302#else
303 pid_t pid = vfork();
304 if (pid < 0) /* error */
305 bb_perror_msg_and_die("vfork");
306 if (pid != 0) {
307 /* parent */
308 /* why _exit? the child may have changed the stack,
309 * so "return 0" may do bad things */
310 _exit(0);
311 }
312 /* child */
313 setsid(); /* detach from controlling tty */
314 /* Redirect stdio to /dev/null, close extra FDs.
315 * We do not actually daemonize because of DAEMON_ONLY_SANITIZE */
316 bb_daemonize_or_rexec(
317 DAEMON_DEVNULL_STDIO
318 + DAEMON_CLOSE_EXTRA_FDS
319 + DAEMON_ONLY_SANITIZE,
320 NULL /* argv, unused */ );
321#endif
322 }
323 if (opt & OPT_MAKEPID) {
324 /* user wants _us_ to make the pidfile */
325 write_pidfile(pidfile);
326 }
327 if (opt & OPT_c) {
328 struct bb_uidgid_t ugid;
329 parse_chown_usergroup_or_die(&ugid, chuid);
330 if (ugid.gid != (gid_t) -1) xsetgid(ugid.gid);
331 if (ugid.uid != (uid_t) -1) xsetuid(ugid.uid);
332 }
333#if ENABLE_FEATURE_START_STOP_DAEMON_FANCY
334 if (opt & OPT_NICELEVEL) {
335 /* Set process priority */
336 int prio = getpriority(PRIO_PROCESS, 0) + xatoi_range(opt_N, INT_MIN/2, INT_MAX/2);
337 if (setpriority(PRIO_PROCESS, 0, prio) < 0) {
338 bb_perror_msg_and_die("setpriority(%d)", prio);
339 }
340 }
341#endif
342 execv(startas, argv);
343 bb_perror_msg_and_die("cannot start %s", startas);
344}
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