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Commit | Line | Data |
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0b452006 RC |
1 | /*** |
2 | This file is part of systemd. | |
3 | ||
4 | Copyright 2010 Lennart Poettering | |
5 | ||
6 | systemd is free software; you can redistribute it and/or modify it | |
7 | under the terms of the GNU Lesser General Public License as published by | |
8 | the Free Software Foundation; either version 2.1 of the License, or | |
9 | (at your option) any later version. | |
10 | ||
11 | systemd is distributed in the hope that it will be useful, but | |
12 | WITHOUT ANY WARRANTY; without even the implied warranty of | |
13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
14 | Lesser General Public License for more details. | |
15 | ||
16 | You should have received a copy of the GNU Lesser General Public License | |
17 | along with systemd; If not, see <http://www.gnu.org/licenses/>. | |
18 | ***/ | |
19 | ||
0b452006 | 20 | #include <assert.h> |
4f5dd394 | 21 | #include <ctype.h> |
0b452006 | 22 | #include <errno.h> |
0b452006 | 23 | #include <signal.h> |
4f5dd394 LP |
24 | #include <stdbool.h> |
25 | #include <stdio.h> | |
26 | #include <string.h> | |
27 | #include <sys/types.h> | |
28 | #include <sys/wait.h> | |
29 | #include <unistd.h> | |
0b452006 | 30 | |
4f5dd394 | 31 | #include "escape.h" |
0b452006 | 32 | #include "fileio.h" |
0b452006 | 33 | #include "log.h" |
24882e06 | 34 | #include "signal-util.h" |
4f5dd394 | 35 | #include "util.h" |
24882e06 | 36 | #include "process-util.h" |
0b452006 RC |
37 | |
38 | int get_process_state(pid_t pid) { | |
39 | const char *p; | |
40 | char state; | |
41 | int r; | |
42 | _cleanup_free_ char *line = NULL; | |
43 | ||
44 | assert(pid >= 0); | |
45 | ||
46 | p = procfs_file_alloca(pid, "stat"); | |
a644184a | 47 | |
0b452006 | 48 | r = read_one_line_file(p, &line); |
a644184a LP |
49 | if (r == -ENOENT) |
50 | return -ESRCH; | |
0b452006 RC |
51 | if (r < 0) |
52 | return r; | |
53 | ||
54 | p = strrchr(line, ')'); | |
55 | if (!p) | |
56 | return -EIO; | |
57 | ||
58 | p++; | |
59 | ||
60 | if (sscanf(p, " %c", &state) != 1) | |
61 | return -EIO; | |
62 | ||
63 | return (unsigned char) state; | |
64 | } | |
65 | ||
66 | int get_process_comm(pid_t pid, char **name) { | |
67 | const char *p; | |
68 | int r; | |
69 | ||
70 | assert(name); | |
71 | assert(pid >= 0); | |
72 | ||
73 | p = procfs_file_alloca(pid, "comm"); | |
74 | ||
75 | r = read_one_line_file(p, name); | |
76 | if (r == -ENOENT) | |
77 | return -ESRCH; | |
78 | ||
79 | return r; | |
80 | } | |
81 | ||
82 | int get_process_cmdline(pid_t pid, size_t max_length, bool comm_fallback, char **line) { | |
83 | _cleanup_fclose_ FILE *f = NULL; | |
84 | char *r = NULL, *k; | |
85 | const char *p; | |
86 | int c; | |
87 | ||
88 | assert(line); | |
89 | assert(pid >= 0); | |
90 | ||
91 | p = procfs_file_alloca(pid, "cmdline"); | |
92 | ||
93 | f = fopen(p, "re"); | |
a644184a LP |
94 | if (!f) { |
95 | if (errno == ENOENT) | |
96 | return -ESRCH; | |
0b452006 | 97 | return -errno; |
a644184a | 98 | } |
0b452006 RC |
99 | |
100 | if (max_length == 0) { | |
101 | size_t len = 0, allocated = 0; | |
102 | ||
103 | while ((c = getc(f)) != EOF) { | |
104 | ||
105 | if (!GREEDY_REALLOC(r, allocated, len+2)) { | |
106 | free(r); | |
107 | return -ENOMEM; | |
108 | } | |
109 | ||
110 | r[len++] = isprint(c) ? c : ' '; | |
111 | } | |
112 | ||
113 | if (len > 0) | |
114 | r[len-1] = 0; | |
115 | ||
116 | } else { | |
117 | bool space = false; | |
118 | size_t left; | |
119 | ||
120 | r = new(char, max_length); | |
121 | if (!r) | |
122 | return -ENOMEM; | |
123 | ||
124 | k = r; | |
125 | left = max_length; | |
126 | while ((c = getc(f)) != EOF) { | |
127 | ||
128 | if (isprint(c)) { | |
129 | if (space) { | |
130 | if (left <= 4) | |
131 | break; | |
132 | ||
133 | *(k++) = ' '; | |
134 | left--; | |
135 | space = false; | |
136 | } | |
137 | ||
138 | if (left <= 4) | |
139 | break; | |
140 | ||
141 | *(k++) = (char) c; | |
142 | left--; | |
143 | } else | |
144 | space = true; | |
145 | } | |
146 | ||
147 | if (left <= 4) { | |
148 | size_t n = MIN(left-1, 3U); | |
149 | memcpy(k, "...", n); | |
150 | k[n] = 0; | |
151 | } else | |
152 | *k = 0; | |
153 | } | |
154 | ||
155 | /* Kernel threads have no argv[] */ | |
156 | if (isempty(r)) { | |
157 | _cleanup_free_ char *t = NULL; | |
158 | int h; | |
159 | ||
160 | free(r); | |
161 | ||
162 | if (!comm_fallback) | |
163 | return -ENOENT; | |
164 | ||
165 | h = get_process_comm(pid, &t); | |
166 | if (h < 0) | |
167 | return h; | |
168 | ||
169 | r = strjoin("[", t, "]", NULL); | |
170 | if (!r) | |
171 | return -ENOMEM; | |
172 | } | |
173 | ||
174 | *line = r; | |
175 | return 0; | |
176 | } | |
177 | ||
178 | int is_kernel_thread(pid_t pid) { | |
179 | const char *p; | |
180 | size_t count; | |
181 | char c; | |
182 | bool eof; | |
183 | FILE *f; | |
184 | ||
a6149b93 | 185 | if (pid == 0 || pid == 1) /* pid 1, and we ourselves certainly aren't a kernel thread */ |
0b452006 RC |
186 | return 0; |
187 | ||
a6149b93 | 188 | assert(pid > 1); |
0b452006 RC |
189 | |
190 | p = procfs_file_alloca(pid, "cmdline"); | |
191 | f = fopen(p, "re"); | |
a644184a LP |
192 | if (!f) { |
193 | if (errno == ENOENT) | |
194 | return -ESRCH; | |
0b452006 | 195 | return -errno; |
a644184a | 196 | } |
0b452006 RC |
197 | |
198 | count = fread(&c, 1, 1, f); | |
199 | eof = feof(f); | |
200 | fclose(f); | |
201 | ||
202 | /* Kernel threads have an empty cmdline */ | |
203 | ||
204 | if (count <= 0) | |
205 | return eof ? 1 : -errno; | |
206 | ||
207 | return 0; | |
208 | } | |
209 | ||
210 | int get_process_capeff(pid_t pid, char **capeff) { | |
211 | const char *p; | |
a644184a | 212 | int r; |
0b452006 RC |
213 | |
214 | assert(capeff); | |
215 | assert(pid >= 0); | |
216 | ||
217 | p = procfs_file_alloca(pid, "status"); | |
218 | ||
c4cd1d4d | 219 | r = get_proc_field(p, "CapEff", WHITESPACE, capeff); |
a644184a LP |
220 | if (r == -ENOENT) |
221 | return -ESRCH; | |
222 | ||
223 | return r; | |
0b452006 RC |
224 | } |
225 | ||
226 | static int get_process_link_contents(const char *proc_file, char **name) { | |
227 | int r; | |
228 | ||
229 | assert(proc_file); | |
230 | assert(name); | |
231 | ||
232 | r = readlink_malloc(proc_file, name); | |
a644184a LP |
233 | if (r == -ENOENT) |
234 | return -ESRCH; | |
0b452006 | 235 | if (r < 0) |
a644184a | 236 | return r; |
0b452006 RC |
237 | |
238 | return 0; | |
239 | } | |
240 | ||
241 | int get_process_exe(pid_t pid, char **name) { | |
242 | const char *p; | |
243 | char *d; | |
244 | int r; | |
245 | ||
246 | assert(pid >= 0); | |
247 | ||
248 | p = procfs_file_alloca(pid, "exe"); | |
249 | r = get_process_link_contents(p, name); | |
250 | if (r < 0) | |
251 | return r; | |
252 | ||
253 | d = endswith(*name, " (deleted)"); | |
254 | if (d) | |
255 | *d = '\0'; | |
256 | ||
257 | return 0; | |
258 | } | |
259 | ||
260 | static int get_process_id(pid_t pid, const char *field, uid_t *uid) { | |
261 | _cleanup_fclose_ FILE *f = NULL; | |
262 | char line[LINE_MAX]; | |
263 | const char *p; | |
264 | ||
265 | assert(field); | |
266 | assert(uid); | |
267 | ||
268 | if (pid == 0) | |
269 | return getuid(); | |
270 | ||
271 | p = procfs_file_alloca(pid, "status"); | |
272 | f = fopen(p, "re"); | |
a644184a LP |
273 | if (!f) { |
274 | if (errno == ENOENT) | |
275 | return -ESRCH; | |
0b452006 | 276 | return -errno; |
a644184a | 277 | } |
0b452006 RC |
278 | |
279 | FOREACH_LINE(line, f, return -errno) { | |
280 | char *l; | |
281 | ||
282 | l = strstrip(line); | |
283 | ||
284 | if (startswith(l, field)) { | |
285 | l += strlen(field); | |
286 | l += strspn(l, WHITESPACE); | |
287 | ||
288 | l[strcspn(l, WHITESPACE)] = 0; | |
289 | ||
290 | return parse_uid(l, uid); | |
291 | } | |
292 | } | |
293 | ||
294 | return -EIO; | |
295 | } | |
296 | ||
297 | int get_process_uid(pid_t pid, uid_t *uid) { | |
298 | return get_process_id(pid, "Uid:", uid); | |
299 | } | |
300 | ||
301 | int get_process_gid(pid_t pid, gid_t *gid) { | |
302 | assert_cc(sizeof(uid_t) == sizeof(gid_t)); | |
303 | return get_process_id(pid, "Gid:", gid); | |
304 | } | |
305 | ||
306 | int get_process_cwd(pid_t pid, char **cwd) { | |
307 | const char *p; | |
308 | ||
309 | assert(pid >= 0); | |
310 | ||
311 | p = procfs_file_alloca(pid, "cwd"); | |
312 | ||
313 | return get_process_link_contents(p, cwd); | |
314 | } | |
315 | ||
316 | int get_process_root(pid_t pid, char **root) { | |
317 | const char *p; | |
318 | ||
319 | assert(pid >= 0); | |
320 | ||
321 | p = procfs_file_alloca(pid, "root"); | |
322 | ||
323 | return get_process_link_contents(p, root); | |
324 | } | |
325 | ||
326 | int get_process_environ(pid_t pid, char **env) { | |
327 | _cleanup_fclose_ FILE *f = NULL; | |
328 | _cleanup_free_ char *outcome = NULL; | |
329 | int c; | |
330 | const char *p; | |
331 | size_t allocated = 0, sz = 0; | |
332 | ||
333 | assert(pid >= 0); | |
334 | assert(env); | |
335 | ||
336 | p = procfs_file_alloca(pid, "environ"); | |
337 | ||
338 | f = fopen(p, "re"); | |
a644184a LP |
339 | if (!f) { |
340 | if (errno == ENOENT) | |
341 | return -ESRCH; | |
0b452006 | 342 | return -errno; |
a644184a | 343 | } |
0b452006 RC |
344 | |
345 | while ((c = fgetc(f)) != EOF) { | |
346 | if (!GREEDY_REALLOC(outcome, allocated, sz + 5)) | |
347 | return -ENOMEM; | |
348 | ||
349 | if (c == '\0') | |
350 | outcome[sz++] = '\n'; | |
351 | else | |
352 | sz += cescape_char(c, outcome + sz); | |
353 | } | |
354 | ||
03c55bc0 LP |
355 | if (!outcome) { |
356 | outcome = strdup(""); | |
357 | if (!outcome) | |
358 | return -ENOMEM; | |
359 | } else | |
360 | outcome[sz] = '\0'; | |
de8763b6 | 361 | |
0b452006 RC |
362 | *env = outcome; |
363 | outcome = NULL; | |
364 | ||
365 | return 0; | |
366 | } | |
367 | ||
368 | int get_parent_of_pid(pid_t pid, pid_t *_ppid) { | |
369 | int r; | |
370 | _cleanup_free_ char *line = NULL; | |
371 | long unsigned ppid; | |
372 | const char *p; | |
373 | ||
374 | assert(pid >= 0); | |
375 | assert(_ppid); | |
376 | ||
377 | if (pid == 0) { | |
378 | *_ppid = getppid(); | |
379 | return 0; | |
380 | } | |
381 | ||
382 | p = procfs_file_alloca(pid, "stat"); | |
383 | r = read_one_line_file(p, &line); | |
a644184a LP |
384 | if (r == -ENOENT) |
385 | return -ESRCH; | |
0b452006 RC |
386 | if (r < 0) |
387 | return r; | |
388 | ||
389 | /* Let's skip the pid and comm fields. The latter is enclosed | |
390 | * in () but does not escape any () in its value, so let's | |
391 | * skip over it manually */ | |
392 | ||
393 | p = strrchr(line, ')'); | |
394 | if (!p) | |
395 | return -EIO; | |
396 | ||
397 | p++; | |
398 | ||
399 | if (sscanf(p, " " | |
400 | "%*c " /* state */ | |
401 | "%lu ", /* ppid */ | |
402 | &ppid) != 1) | |
403 | return -EIO; | |
404 | ||
405 | if ((long unsigned) (pid_t) ppid != ppid) | |
406 | return -ERANGE; | |
407 | ||
408 | *_ppid = (pid_t) ppid; | |
409 | ||
410 | return 0; | |
411 | } | |
412 | ||
413 | int wait_for_terminate(pid_t pid, siginfo_t *status) { | |
414 | siginfo_t dummy; | |
415 | ||
416 | assert(pid >= 1); | |
417 | ||
418 | if (!status) | |
419 | status = &dummy; | |
420 | ||
421 | for (;;) { | |
422 | zero(*status); | |
423 | ||
424 | if (waitid(P_PID, pid, status, WEXITED) < 0) { | |
425 | ||
426 | if (errno == EINTR) | |
427 | continue; | |
428 | ||
429 | return -errno; | |
430 | } | |
431 | ||
432 | return 0; | |
433 | } | |
434 | } | |
435 | ||
436 | /* | |
437 | * Return values: | |
438 | * < 0 : wait_for_terminate() failed to get the state of the | |
439 | * process, the process was terminated by a signal, or | |
440 | * failed for an unknown reason. | |
441 | * >=0 : The process terminated normally, and its exit code is | |
442 | * returned. | |
443 | * | |
444 | * That is, success is indicated by a return value of zero, and an | |
445 | * error is indicated by a non-zero value. | |
446 | * | |
447 | * A warning is emitted if the process terminates abnormally, | |
448 | * and also if it returns non-zero unless check_exit_code is true. | |
449 | */ | |
450 | int wait_for_terminate_and_warn(const char *name, pid_t pid, bool check_exit_code) { | |
451 | int r; | |
452 | siginfo_t status; | |
453 | ||
454 | assert(name); | |
455 | assert(pid > 1); | |
456 | ||
457 | r = wait_for_terminate(pid, &status); | |
458 | if (r < 0) | |
459 | return log_warning_errno(r, "Failed to wait for %s: %m", name); | |
460 | ||
461 | if (status.si_code == CLD_EXITED) { | |
462 | if (status.si_status != 0) | |
463 | log_full(check_exit_code ? LOG_WARNING : LOG_DEBUG, | |
464 | "%s failed with error code %i.", name, status.si_status); | |
465 | else | |
466 | log_debug("%s succeeded.", name); | |
467 | ||
468 | return status.si_status; | |
469 | } else if (status.si_code == CLD_KILLED || | |
470 | status.si_code == CLD_DUMPED) { | |
471 | ||
472 | log_warning("%s terminated by signal %s.", name, signal_to_string(status.si_status)); | |
473 | return -EPROTO; | |
474 | } | |
475 | ||
476 | log_warning("%s failed due to unknown reason.", name); | |
477 | return -EPROTO; | |
478 | } | |
479 | ||
480 | int kill_and_sigcont(pid_t pid, int sig) { | |
481 | int r; | |
482 | ||
483 | r = kill(pid, sig) < 0 ? -errno : 0; | |
484 | ||
485 | if (r >= 0) | |
486 | kill(pid, SIGCONT); | |
487 | ||
488 | return r; | |
489 | } | |
490 | ||
491 | int getenv_for_pid(pid_t pid, const char *field, char **_value) { | |
492 | _cleanup_fclose_ FILE *f = NULL; | |
493 | char *value = NULL; | |
494 | int r; | |
495 | bool done = false; | |
496 | size_t l; | |
497 | const char *path; | |
498 | ||
499 | assert(pid >= 0); | |
500 | assert(field); | |
501 | assert(_value); | |
502 | ||
503 | path = procfs_file_alloca(pid, "environ"); | |
504 | ||
505 | f = fopen(path, "re"); | |
a644184a LP |
506 | if (!f) { |
507 | if (errno == ENOENT) | |
508 | return -ESRCH; | |
0b452006 | 509 | return -errno; |
a644184a | 510 | } |
0b452006 RC |
511 | |
512 | l = strlen(field); | |
513 | r = 0; | |
514 | ||
515 | do { | |
516 | char line[LINE_MAX]; | |
517 | unsigned i; | |
518 | ||
519 | for (i = 0; i < sizeof(line)-1; i++) { | |
520 | int c; | |
521 | ||
522 | c = getc(f); | |
523 | if (_unlikely_(c == EOF)) { | |
524 | done = true; | |
525 | break; | |
526 | } else if (c == 0) | |
527 | break; | |
528 | ||
529 | line[i] = c; | |
530 | } | |
531 | line[i] = 0; | |
532 | ||
533 | if (memcmp(line, field, l) == 0 && line[l] == '=') { | |
534 | value = strdup(line + l + 1); | |
535 | if (!value) | |
536 | return -ENOMEM; | |
537 | ||
538 | r = 1; | |
539 | break; | |
540 | } | |
541 | ||
542 | } while (!done); | |
543 | ||
544 | *_value = value; | |
545 | return r; | |
546 | } | |
547 | ||
548 | bool pid_is_unwaited(pid_t pid) { | |
549 | /* Checks whether a PID is still valid at all, including a zombie */ | |
550 | ||
551 | if (pid <= 0) | |
552 | return false; | |
553 | ||
554 | if (kill(pid, 0) >= 0) | |
555 | return true; | |
556 | ||
557 | return errno != ESRCH; | |
558 | } | |
559 | ||
560 | bool pid_is_alive(pid_t pid) { | |
561 | int r; | |
562 | ||
563 | /* Checks whether a PID is still valid and not a zombie */ | |
564 | ||
565 | if (pid <= 0) | |
566 | return false; | |
567 | ||
568 | r = get_process_state(pid); | |
a644184a | 569 | if (r == -ESRCH || r == 'Z') |
0b452006 RC |
570 | return false; |
571 | ||
572 | return true; | |
573 | } |