]> git.ipfire.org Git - people/ms/systemd.git/blame - execute.c
monitor udev for device changes
[people/ms/systemd.git] / execute.c
CommitLineData
5cb5a6ff
LP
1/*-*- Mode: C; c-basic-offset: 8 -*-*/
2
3#include <assert.h>
034c6ed7
LP
4#include <dirent.h>
5#include <errno.h>
6#include <fcntl.h>
7#include <unistd.h>
44d8db9e 8#include <string.h>
309bff19 9#include <signal.h>
071830ff
LP
10#include <sys/socket.h>
11#include <sys/un.h>
5cb5a6ff
LP
12
13#include "execute.h"
14#include "strv.h"
15#include "macro.h"
16#include "util.h"
acbb0225 17#include "log.h"
5cb5a6ff 18
034c6ed7
LP
19static int close_fds(int except[], unsigned n_except) {
20 DIR *d;
21 struct dirent *de;
22 int r = 0;
23
24 /* Modifies the fds array! (sorts it) */
25
26 if (!(d = opendir("/proc/self/fd")))
27 return -errno;
28
29 while ((de = readdir(d))) {
30 int fd;
31
32 if (de->d_name[0] == '.')
33 continue;
34
35 if ((r = safe_atoi(de->d_name, &fd)) < 0)
36 goto finish;
37
38 if (fd < 3)
39 continue;
40
41 if (fd == dirfd(d))
42 continue;
43
44 if (except) {
45 bool found;
46 unsigned i;
47
48 found = false;
49 for (i = 0; i < n_except; i++)
50 if (except[i] == fd) {
51 found = true;
52 break;
53 }
54
55 if (found)
56 continue;
57 }
58
59 if ((r = close_nointr(fd)) < 0)
60 goto finish;
61 }
62
63finish:
64 closedir(d);
65 return r;
66}
67
68static int shift_fds(int fds[], unsigned n_fds) {
69 int start, restart_from;
70
71 if (n_fds <= 0)
72 return 0;
73
74 assert(fds);
75
76 start = 0;
77 for (;;) {
78 int i;
79
80 restart_from = -1;
81
82 for (i = start; i < (int) n_fds; i++) {
83 int nfd;
84
85 /* Already at right index? */
86 if (fds[i] == i+3)
87 continue;
88
89 if ((nfd = fcntl(fds[i], F_DUPFD, i+3)) < 0)
90 return -errno;
91
2da3263a 92 assert_se(close_nointr(fds[i]) == 0);
034c6ed7
LP
93 fds[i] = nfd;
94
95 /* Hmm, the fd we wanted isn't free? Then
96 * let's remember that and try again from here*/
97 if (nfd != i+3 && restart_from < 0)
98 restart_from = i;
99 }
100
101 if (restart_from < 0)
102 break;
103
104 start = restart_from;
105 }
106
107 return 0;
108}
109
47a71eed
LP
110static int flags_fds(int fds[], unsigned n_fds) {
111 unsigned i;
112
113 if (n_fds <= 0)
114 return 0;
115
116 assert(fds);
117
118 /* Drops O_NONBLOCK and FD_CLOEXEC from the file flags */
119
120 for (i = 0; i < n_fds; i++) {
121 int flags;
122
123 if ((flags = fcntl(fds[i], F_GETFL, 0)) < 0)
124 return -errno;
125
126 /* Since we are at it, let's make sure that nobody
127 * forgot setting O_NONBLOCK for all our fds */
128
129 if (fcntl(fds[i], F_SETFL, flags &~O_NONBLOCK) < 0)
130 return -errno;
131
132 if ((flags = fcntl(fds[i], F_GETFD, 0)) < 0)
133 return -errno;
134
135 /* Also make sure nobody forgot O_CLOEXEC for all our
136 * fds */
137 if (fcntl(fds[i], F_SETFD, flags &~FD_CLOEXEC) < 0)
138 return -errno;
139 }
140
141 return 0;
142}
143
071830ff
LP
144static int replace_null_fd(int fd, int flags) {
145 int nfd;
146 assert(fd >= 0);
147
148 close_nointr(fd);
149
150 if ((nfd = open("/dev/null", flags|O_NOCTTY)) < 0)
151 return -errno;
152
153 if (nfd != fd) {
154 close_nointr_nofail(nfd);
155 return -EIO;
156 }
157
158 return 0;
159}
160
161static int setup_output(const ExecContext *context, const char *ident) {
162 int r;
163
164 assert(context);
165
166 switch (context->output) {
167
168 case EXEC_CONSOLE:
169 return 0;
170
171 case EXEC_NULL:
172
173 if ((r = replace_null_fd(STDIN_FILENO, O_RDONLY)) < 0 ||
174 (r = replace_null_fd(STDOUT_FILENO, O_WRONLY)) < 0 ||
175 (r = replace_null_fd(STDERR_FILENO, O_WRONLY)) < 0)
176 return r;
177
178 return 0;
179
180 case EXEC_KERNEL:
181 case EXEC_SYSLOG: {
182
183 int fd;
184 union {
185 struct sockaddr sa;
186 struct sockaddr_un un;
187 } sa;
188
189 if ((r = replace_null_fd(STDIN_FILENO, O_RDONLY)) < 0)
190 return r;
191
192 close_nointr(STDOUT_FILENO);
193 close_nointr(STDERR_FILENO);
194
195 if ((fd = socket(AF_UNIX, SOCK_STREAM, 0)) < 0)
196 return -errno;
197
198 if (fd != STDOUT_FILENO) {
199 close_nointr_nofail(fd);
200 return -EIO;
201 }
202
203 zero(sa);
204 sa.sa.sa_family = AF_UNIX;
205 strncpy(sa.un.sun_path+1, LOGGER_SOCKET, sizeof(sa.un.sun_path)-1);
206
207 if (connect(fd, &sa.sa, sizeof(sa)) < 0) {
208 close_nointr_nofail(fd);
209 return -errno;
210 }
211
212 if (shutdown(fd, SHUT_RD) < 0) {
213 close_nointr_nofail(fd);
214 return -errno;
215 }
216
217 if ((fd = dup(fd)) < 0) {
218 close_nointr_nofail(fd);
219 return -errno;
220 }
221
222 if (fd != STDERR_FILENO) {
223 close_nointr_nofail(fd);
224 return -EIO;
225 }
226
227 /* We speak a very simple protocol between log server
228 * and client: one line for the log destination (kmsg
229 * or syslog), followed by the priority field,
230 * followed by the process name. Since we replaced
231 * stdin/stderr we simple use stdio to write to
232 * it. Note that we use stderr, to minimize buffer
233 * flushing issues. */
234
235 fprintf(stderr,
236 "%s\n"
237 "%i\n"
238 "%s\n",
239 context->output == EXEC_KERNEL ? "kmsg" : "syslog",
240 context->syslog_priority,
241 context->syslog_identifier ? context->syslog_identifier : ident);
242
243 return 0;
244 }
245 }
246
247 assert_not_reached("Unknown logging type");
248}
249
034c6ed7
LP
250int exec_spawn(const ExecCommand *command, const ExecContext *context, int *fds, unsigned n_fds, pid_t *ret) {
251 pid_t pid;
252
5cb5a6ff
LP
253 assert(command);
254 assert(context);
255 assert(ret);
034c6ed7
LP
256 assert(fds || n_fds <= 0);
257
2da3263a 258 log_debug("about to execute %s", command->path);
acbb0225 259
034c6ed7
LP
260 if ((pid = fork()) < 0)
261 return -errno;
262
263 if (pid == 0) {
264 char **e, **f = NULL;
265 int i, r;
309bff19
LP
266 sigset_t ss;
267
034c6ed7 268 /* child */
5cb5a6ff 269
309bff19
LP
270 if (sigemptyset(&ss) < 0 ||
271 sigprocmask(SIG_SETMASK, &ss, NULL) < 0) {
272 r = EXIT_SIGNAL_MASK;
273 goto fail;
274 }
275
034c6ed7
LP
276 umask(context->umask);
277
278 if (chdir(context->directory ? context->directory : "/") < 0) {
279 r = EXIT_CHDIR;
280 goto fail;
281 }
282
071830ff
LP
283 if (setup_output(context, file_name_from_path(command->path)) < 0) {
284 r = EXIT_OUTPUT;
285 goto fail;
286 }
287
fb33a393
LP
288 if (context->oom_adjust_set) {
289 char t[16];
034c6ed7 290
fb33a393
LP
291 snprintf(t, sizeof(t), "%i", context->oom_adjust);
292 char_array_0(t);
034c6ed7 293
fb33a393
LP
294 if (write_one_line_file("/proc/self/oom_adj", t) < 0) {
295 r = EXIT_OOM_ADJUST;
296 goto fail;
297 }
034c6ed7
LP
298 }
299
fb33a393
LP
300 if (context->nice_set)
301 if (setpriority(PRIO_PROCESS, 0, context->nice) < 0) {
302 r = EXIT_NICE;
303 goto fail;
304 }
305
034c6ed7 306 if (close_fds(fds, n_fds) < 0 ||
47a71eed
LP
307 shift_fds(fds, n_fds) < 0 ||
308 flags_fds(fds, n_fds) < 0) {
034c6ed7
LP
309 r = EXIT_FDS;
310 goto fail;
311 }
312
313 for (i = 0; i < RLIMIT_NLIMITS; i++) {
314 if (!context->rlimit[i])
315 continue;
316
317 if (setrlimit(i, context->rlimit[i]) < 0) {
318 r = EXIT_LIMITS;
319 goto fail;
320 }
321 }
322
323 if (n_fds > 0) {
324 char a[64], b[64];
325 char *listen_env[3] = {
326 a,
327 b,
328 NULL
329 };
330
331 snprintf(a, sizeof(a), "LISTEN_PID=%llu", (unsigned long long) getpid());
332 snprintf(b, sizeof(b), "LISTEN_FDS=%u", n_fds);
333
334 a[sizeof(a)-1] = 0;
335 b[sizeof(b)-1] = 0;
336
337 if (context->environment) {
338 if (!(f = strv_merge(listen_env, context->environment))) {
339 r = EXIT_MEMORY;
340 goto fail;
341 }
342 e = f;
343 } else
344 e = listen_env;
345
346 } else
347 e = context->environment;
348
349 execve(command->path, command->argv, e);
350 r = EXIT_EXEC;
351
352 fail:
353 strv_free(f);
354 _exit(r);
355 }
356
2da3263a
LP
357
358 log_debug("executed %s as %llu", command->path, (unsigned long long) pid);
359
034c6ed7 360 *ret = pid;
5cb5a6ff
LP
361 return 0;
362}
363
034c6ed7
LP
364void exec_context_init(ExecContext *c) {
365 assert(c);
366
367 c->umask = 0002;
368 cap_clear(c->capabilities);
369 c->oom_adjust = 0;
370 c->nice = 0;
071830ff
LP
371
372 c->output = 0;
373 c->syslog_priority = LOG_DAEMON|LOG_INFO;
034c6ed7
LP
374}
375
376void exec_context_done(ExecContext *c) {
5cb5a6ff
LP
377 unsigned l;
378
379 assert(c);
380
381 strv_free(c->environment);
034c6ed7 382 c->environment = NULL;
5cb5a6ff 383
034c6ed7 384 for (l = 0; l < ELEMENTSOF(c->rlimit); l++) {
5cb5a6ff 385 free(c->rlimit[l]);
034c6ed7
LP
386 c->rlimit[l] = NULL;
387 }
388
389 free(c->directory);
390 c->directory = NULL;
5cb5a6ff 391
071830ff
LP
392 free(c->syslog_identifier);
393 c->syslog_identifier = NULL;
394
5cb5a6ff 395 free(c->user);
034c6ed7
LP
396 c->user = NULL;
397
5cb5a6ff 398 free(c->group);
034c6ed7
LP
399 c->group = NULL;
400
401 strv_free(c->supplementary_groups);
402 c->supplementary_groups = NULL;
5cb5a6ff
LP
403}
404
405void exec_command_free_list(ExecCommand *c) {
406 ExecCommand *i;
407
408 while ((i = c)) {
034c6ed7 409 LIST_REMOVE(ExecCommand, command, c, i);
5cb5a6ff
LP
410
411 free(i->path);
44d8db9e 412 strv_free(i->argv);
5cb5a6ff
LP
413 free(i);
414 }
415}
416
034c6ed7
LP
417void exec_command_free_array(ExecCommand **c, unsigned n) {
418 unsigned i;
419
420 for (i = 0; i < n; i++) {
421 exec_command_free_list(c[i]);
422 c[i] = NULL;
423 }
424}
425
5cb5a6ff
LP
426void exec_context_dump(ExecContext *c, FILE* f, const char *prefix) {
427 assert(c);
428 assert(f);
429
430 if (!prefix)
431 prefix = "";
432
433 fprintf(f,
434 "%sUmask: %04o\n"
fb33a393 435 "%sDirectory: %s\n",
5cb5a6ff 436 prefix, c->umask,
fb33a393
LP
437 prefix, c->directory ? c->directory : "/");
438
439 if (c->nice_set)
440 fprintf(f,
441 "%sNice: %i\n",
442 prefix, c->nice);
443
444 if (c->oom_adjust_set)
445 fprintf(f,
446 "%sOOMAdjust: %i\n",
447 prefix, c->oom_adjust);
5cb5a6ff
LP
448}
449
034c6ed7
LP
450void exec_status_fill(ExecStatus *s, pid_t pid, int code, int status) {
451 assert(s);
5cb5a6ff 452
034c6ed7
LP
453 s->pid = pid;
454 s->code = code;
455 s->status = status;
456 s->timestamp = now(CLOCK_REALTIME);
5cb5a6ff 457}
44d8db9e
LP
458
459char *exec_command_line(ExecCommand *c) {
460 size_t k;
461 char *n, *p, **a;
462 bool first = true;
463
464 assert(c);
465 assert(c->argv);
466
9164977d 467 k = 1;
44d8db9e
LP
468 STRV_FOREACH(a, c->argv)
469 k += strlen(*a)+3;
470
471 if (!(n = new(char, k)))
472 return NULL;
473
474 p = n;
475 STRV_FOREACH(a, c->argv) {
476
477 if (!first)
478 *(p++) = ' ';
479 else
480 first = false;
481
482 if (strpbrk(*a, WHITESPACE)) {
483 *(p++) = '\'';
484 p = stpcpy(p, *a);
485 *(p++) = '\'';
486 } else
487 p = stpcpy(p, *a);
488
489 }
490
9164977d
LP
491 *p = 0;
492
44d8db9e
LP
493 /* FIXME: this doesn't really handle arguments that have
494 * spaces and ticks in them */
495
496 return n;
497}
498
499void exec_command_dump(ExecCommand *c, FILE *f, const char *prefix) {
500 char *cmd;
501
502 assert(c);
503 assert(f);
504
505 if (!prefix)
506 prefix = "";
507
508 cmd = exec_command_line(c);
509
510 fprintf(f,
511 "%sCommand Line: %s\n",
512 prefix, cmd ? cmd : strerror(ENOMEM));
513
514 free(cmd);
515}
516
517void exec_command_dump_list(ExecCommand *c, FILE *f, const char *prefix) {
518 assert(f);
519
520 if (!prefix)
521 prefix = "";
522
523 LIST_FOREACH(command, c, c)
524 exec_command_dump(c, f, prefix);
525}