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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" |
3ffd4af2 | 32 | #include "fd-util.h" |
0b452006 | 33 | #include "fileio.h" |
0b452006 | 34 | #include "log.h" |
3ffd4af2 | 35 | #include "process-util.h" |
24882e06 | 36 | #include "signal-util.h" |
07630cea | 37 | #include "string-util.h" |
b1d4f8e1 | 38 | #include "user-util.h" |
4f5dd394 | 39 | #include "util.h" |
0b452006 RC |
40 | |
41 | int get_process_state(pid_t pid) { | |
42 | const char *p; | |
43 | char state; | |
44 | int r; | |
45 | _cleanup_free_ char *line = NULL; | |
46 | ||
47 | assert(pid >= 0); | |
48 | ||
49 | p = procfs_file_alloca(pid, "stat"); | |
a644184a | 50 | |
0b452006 | 51 | r = read_one_line_file(p, &line); |
a644184a LP |
52 | if (r == -ENOENT) |
53 | return -ESRCH; | |
0b452006 RC |
54 | if (r < 0) |
55 | return r; | |
56 | ||
57 | p = strrchr(line, ')'); | |
58 | if (!p) | |
59 | return -EIO; | |
60 | ||
61 | p++; | |
62 | ||
63 | if (sscanf(p, " %c", &state) != 1) | |
64 | return -EIO; | |
65 | ||
66 | return (unsigned char) state; | |
67 | } | |
68 | ||
69 | int get_process_comm(pid_t pid, char **name) { | |
70 | const char *p; | |
71 | int r; | |
72 | ||
73 | assert(name); | |
74 | assert(pid >= 0); | |
75 | ||
76 | p = procfs_file_alloca(pid, "comm"); | |
77 | ||
78 | r = read_one_line_file(p, name); | |
79 | if (r == -ENOENT) | |
80 | return -ESRCH; | |
81 | ||
82 | return r; | |
83 | } | |
84 | ||
85 | int get_process_cmdline(pid_t pid, size_t max_length, bool comm_fallback, char **line) { | |
86 | _cleanup_fclose_ FILE *f = NULL; | |
87 | char *r = NULL, *k; | |
88 | const char *p; | |
89 | int c; | |
90 | ||
91 | assert(line); | |
92 | assert(pid >= 0); | |
93 | ||
94 | p = procfs_file_alloca(pid, "cmdline"); | |
95 | ||
96 | f = fopen(p, "re"); | |
a644184a LP |
97 | if (!f) { |
98 | if (errno == ENOENT) | |
99 | return -ESRCH; | |
0b452006 | 100 | return -errno; |
a644184a | 101 | } |
0b452006 RC |
102 | |
103 | if (max_length == 0) { | |
104 | size_t len = 0, allocated = 0; | |
105 | ||
106 | while ((c = getc(f)) != EOF) { | |
107 | ||
108 | if (!GREEDY_REALLOC(r, allocated, len+2)) { | |
109 | free(r); | |
110 | return -ENOMEM; | |
111 | } | |
112 | ||
113 | r[len++] = isprint(c) ? c : ' '; | |
114 | } | |
115 | ||
116 | if (len > 0) | |
117 | r[len-1] = 0; | |
118 | ||
119 | } else { | |
120 | bool space = false; | |
121 | size_t left; | |
122 | ||
123 | r = new(char, max_length); | |
124 | if (!r) | |
125 | return -ENOMEM; | |
126 | ||
127 | k = r; | |
128 | left = max_length; | |
129 | while ((c = getc(f)) != EOF) { | |
130 | ||
131 | if (isprint(c)) { | |
132 | if (space) { | |
133 | if (left <= 4) | |
134 | break; | |
135 | ||
136 | *(k++) = ' '; | |
137 | left--; | |
138 | space = false; | |
139 | } | |
140 | ||
141 | if (left <= 4) | |
142 | break; | |
143 | ||
144 | *(k++) = (char) c; | |
145 | left--; | |
146 | } else | |
147 | space = true; | |
148 | } | |
149 | ||
150 | if (left <= 4) { | |
151 | size_t n = MIN(left-1, 3U); | |
152 | memcpy(k, "...", n); | |
153 | k[n] = 0; | |
154 | } else | |
155 | *k = 0; | |
156 | } | |
157 | ||
158 | /* Kernel threads have no argv[] */ | |
159 | if (isempty(r)) { | |
160 | _cleanup_free_ char *t = NULL; | |
161 | int h; | |
162 | ||
163 | free(r); | |
164 | ||
165 | if (!comm_fallback) | |
166 | return -ENOENT; | |
167 | ||
168 | h = get_process_comm(pid, &t); | |
169 | if (h < 0) | |
170 | return h; | |
171 | ||
172 | r = strjoin("[", t, "]", NULL); | |
173 | if (!r) | |
174 | return -ENOMEM; | |
175 | } | |
176 | ||
177 | *line = r; | |
178 | return 0; | |
179 | } | |
180 | ||
181 | int is_kernel_thread(pid_t pid) { | |
182 | const char *p; | |
183 | size_t count; | |
184 | char c; | |
185 | bool eof; | |
186 | FILE *f; | |
187 | ||
a6149b93 | 188 | if (pid == 0 || pid == 1) /* pid 1, and we ourselves certainly aren't a kernel thread */ |
0b452006 RC |
189 | return 0; |
190 | ||
a6149b93 | 191 | assert(pid > 1); |
0b452006 RC |
192 | |
193 | p = procfs_file_alloca(pid, "cmdline"); | |
194 | f = fopen(p, "re"); | |
a644184a LP |
195 | if (!f) { |
196 | if (errno == ENOENT) | |
197 | return -ESRCH; | |
0b452006 | 198 | return -errno; |
a644184a | 199 | } |
0b452006 RC |
200 | |
201 | count = fread(&c, 1, 1, f); | |
202 | eof = feof(f); | |
203 | fclose(f); | |
204 | ||
205 | /* Kernel threads have an empty cmdline */ | |
206 | ||
207 | if (count <= 0) | |
208 | return eof ? 1 : -errno; | |
209 | ||
210 | return 0; | |
211 | } | |
212 | ||
213 | int get_process_capeff(pid_t pid, char **capeff) { | |
214 | const char *p; | |
a644184a | 215 | int r; |
0b452006 RC |
216 | |
217 | assert(capeff); | |
218 | assert(pid >= 0); | |
219 | ||
220 | p = procfs_file_alloca(pid, "status"); | |
221 | ||
c4cd1d4d | 222 | r = get_proc_field(p, "CapEff", WHITESPACE, capeff); |
a644184a LP |
223 | if (r == -ENOENT) |
224 | return -ESRCH; | |
225 | ||
226 | return r; | |
0b452006 RC |
227 | } |
228 | ||
229 | static int get_process_link_contents(const char *proc_file, char **name) { | |
230 | int r; | |
231 | ||
232 | assert(proc_file); | |
233 | assert(name); | |
234 | ||
235 | r = readlink_malloc(proc_file, name); | |
a644184a LP |
236 | if (r == -ENOENT) |
237 | return -ESRCH; | |
0b452006 | 238 | if (r < 0) |
a644184a | 239 | return r; |
0b452006 RC |
240 | |
241 | return 0; | |
242 | } | |
243 | ||
244 | int get_process_exe(pid_t pid, char **name) { | |
245 | const char *p; | |
246 | char *d; | |
247 | int r; | |
248 | ||
249 | assert(pid >= 0); | |
250 | ||
251 | p = procfs_file_alloca(pid, "exe"); | |
252 | r = get_process_link_contents(p, name); | |
253 | if (r < 0) | |
254 | return r; | |
255 | ||
256 | d = endswith(*name, " (deleted)"); | |
257 | if (d) | |
258 | *d = '\0'; | |
259 | ||
260 | return 0; | |
261 | } | |
262 | ||
263 | static int get_process_id(pid_t pid, const char *field, uid_t *uid) { | |
264 | _cleanup_fclose_ FILE *f = NULL; | |
265 | char line[LINE_MAX]; | |
266 | const char *p; | |
267 | ||
268 | assert(field); | |
269 | assert(uid); | |
270 | ||
271 | if (pid == 0) | |
272 | return getuid(); | |
273 | ||
274 | p = procfs_file_alloca(pid, "status"); | |
275 | f = fopen(p, "re"); | |
a644184a LP |
276 | if (!f) { |
277 | if (errno == ENOENT) | |
278 | return -ESRCH; | |
0b452006 | 279 | return -errno; |
a644184a | 280 | } |
0b452006 RC |
281 | |
282 | FOREACH_LINE(line, f, return -errno) { | |
283 | char *l; | |
284 | ||
285 | l = strstrip(line); | |
286 | ||
287 | if (startswith(l, field)) { | |
288 | l += strlen(field); | |
289 | l += strspn(l, WHITESPACE); | |
290 | ||
291 | l[strcspn(l, WHITESPACE)] = 0; | |
292 | ||
293 | return parse_uid(l, uid); | |
294 | } | |
295 | } | |
296 | ||
297 | return -EIO; | |
298 | } | |
299 | ||
300 | int get_process_uid(pid_t pid, uid_t *uid) { | |
301 | return get_process_id(pid, "Uid:", uid); | |
302 | } | |
303 | ||
304 | int get_process_gid(pid_t pid, gid_t *gid) { | |
305 | assert_cc(sizeof(uid_t) == sizeof(gid_t)); | |
306 | return get_process_id(pid, "Gid:", gid); | |
307 | } | |
308 | ||
309 | int get_process_cwd(pid_t pid, char **cwd) { | |
310 | const char *p; | |
311 | ||
312 | assert(pid >= 0); | |
313 | ||
314 | p = procfs_file_alloca(pid, "cwd"); | |
315 | ||
316 | return get_process_link_contents(p, cwd); | |
317 | } | |
318 | ||
319 | int get_process_root(pid_t pid, char **root) { | |
320 | const char *p; | |
321 | ||
322 | assert(pid >= 0); | |
323 | ||
324 | p = procfs_file_alloca(pid, "root"); | |
325 | ||
326 | return get_process_link_contents(p, root); | |
327 | } | |
328 | ||
329 | int get_process_environ(pid_t pid, char **env) { | |
330 | _cleanup_fclose_ FILE *f = NULL; | |
331 | _cleanup_free_ char *outcome = NULL; | |
332 | int c; | |
333 | const char *p; | |
334 | size_t allocated = 0, sz = 0; | |
335 | ||
336 | assert(pid >= 0); | |
337 | assert(env); | |
338 | ||
339 | p = procfs_file_alloca(pid, "environ"); | |
340 | ||
341 | f = fopen(p, "re"); | |
a644184a LP |
342 | if (!f) { |
343 | if (errno == ENOENT) | |
344 | return -ESRCH; | |
0b452006 | 345 | return -errno; |
a644184a | 346 | } |
0b452006 RC |
347 | |
348 | while ((c = fgetc(f)) != EOF) { | |
349 | if (!GREEDY_REALLOC(outcome, allocated, sz + 5)) | |
350 | return -ENOMEM; | |
351 | ||
352 | if (c == '\0') | |
353 | outcome[sz++] = '\n'; | |
354 | else | |
355 | sz += cescape_char(c, outcome + sz); | |
356 | } | |
357 | ||
03c55bc0 LP |
358 | if (!outcome) { |
359 | outcome = strdup(""); | |
360 | if (!outcome) | |
361 | return -ENOMEM; | |
362 | } else | |
363 | outcome[sz] = '\0'; | |
de8763b6 | 364 | |
0b452006 RC |
365 | *env = outcome; |
366 | outcome = NULL; | |
367 | ||
368 | return 0; | |
369 | } | |
370 | ||
371 | int get_parent_of_pid(pid_t pid, pid_t *_ppid) { | |
372 | int r; | |
373 | _cleanup_free_ char *line = NULL; | |
374 | long unsigned ppid; | |
375 | const char *p; | |
376 | ||
377 | assert(pid >= 0); | |
378 | assert(_ppid); | |
379 | ||
380 | if (pid == 0) { | |
381 | *_ppid = getppid(); | |
382 | return 0; | |
383 | } | |
384 | ||
385 | p = procfs_file_alloca(pid, "stat"); | |
386 | r = read_one_line_file(p, &line); | |
a644184a LP |
387 | if (r == -ENOENT) |
388 | return -ESRCH; | |
0b452006 RC |
389 | if (r < 0) |
390 | return r; | |
391 | ||
392 | /* Let's skip the pid and comm fields. The latter is enclosed | |
393 | * in () but does not escape any () in its value, so let's | |
394 | * skip over it manually */ | |
395 | ||
396 | p = strrchr(line, ')'); | |
397 | if (!p) | |
398 | return -EIO; | |
399 | ||
400 | p++; | |
401 | ||
402 | if (sscanf(p, " " | |
403 | "%*c " /* state */ | |
404 | "%lu ", /* ppid */ | |
405 | &ppid) != 1) | |
406 | return -EIO; | |
407 | ||
408 | if ((long unsigned) (pid_t) ppid != ppid) | |
409 | return -ERANGE; | |
410 | ||
411 | *_ppid = (pid_t) ppid; | |
412 | ||
413 | return 0; | |
414 | } | |
415 | ||
416 | int wait_for_terminate(pid_t pid, siginfo_t *status) { | |
417 | siginfo_t dummy; | |
418 | ||
419 | assert(pid >= 1); | |
420 | ||
421 | if (!status) | |
422 | status = &dummy; | |
423 | ||
424 | for (;;) { | |
425 | zero(*status); | |
426 | ||
427 | if (waitid(P_PID, pid, status, WEXITED) < 0) { | |
428 | ||
429 | if (errno == EINTR) | |
430 | continue; | |
431 | ||
432 | return -errno; | |
433 | } | |
434 | ||
435 | return 0; | |
436 | } | |
437 | } | |
438 | ||
439 | /* | |
440 | * Return values: | |
441 | * < 0 : wait_for_terminate() failed to get the state of the | |
442 | * process, the process was terminated by a signal, or | |
443 | * failed for an unknown reason. | |
444 | * >=0 : The process terminated normally, and its exit code is | |
445 | * returned. | |
446 | * | |
447 | * That is, success is indicated by a return value of zero, and an | |
448 | * error is indicated by a non-zero value. | |
449 | * | |
450 | * A warning is emitted if the process terminates abnormally, | |
451 | * and also if it returns non-zero unless check_exit_code is true. | |
452 | */ | |
453 | int wait_for_terminate_and_warn(const char *name, pid_t pid, bool check_exit_code) { | |
454 | int r; | |
455 | siginfo_t status; | |
456 | ||
457 | assert(name); | |
458 | assert(pid > 1); | |
459 | ||
460 | r = wait_for_terminate(pid, &status); | |
461 | if (r < 0) | |
462 | return log_warning_errno(r, "Failed to wait for %s: %m", name); | |
463 | ||
464 | if (status.si_code == CLD_EXITED) { | |
465 | if (status.si_status != 0) | |
466 | log_full(check_exit_code ? LOG_WARNING : LOG_DEBUG, | |
467 | "%s failed with error code %i.", name, status.si_status); | |
468 | else | |
469 | log_debug("%s succeeded.", name); | |
470 | ||
471 | return status.si_status; | |
472 | } else if (status.si_code == CLD_KILLED || | |
473 | status.si_code == CLD_DUMPED) { | |
474 | ||
475 | log_warning("%s terminated by signal %s.", name, signal_to_string(status.si_status)); | |
476 | return -EPROTO; | |
477 | } | |
478 | ||
479 | log_warning("%s failed due to unknown reason.", name); | |
480 | return -EPROTO; | |
481 | } | |
482 | ||
483 | int kill_and_sigcont(pid_t pid, int sig) { | |
484 | int r; | |
485 | ||
486 | r = kill(pid, sig) < 0 ? -errno : 0; | |
487 | ||
488 | if (r >= 0) | |
489 | kill(pid, SIGCONT); | |
490 | ||
491 | return r; | |
492 | } | |
493 | ||
494 | int getenv_for_pid(pid_t pid, const char *field, char **_value) { | |
495 | _cleanup_fclose_ FILE *f = NULL; | |
496 | char *value = NULL; | |
497 | int r; | |
498 | bool done = false; | |
499 | size_t l; | |
500 | const char *path; | |
501 | ||
502 | assert(pid >= 0); | |
503 | assert(field); | |
504 | assert(_value); | |
505 | ||
506 | path = procfs_file_alloca(pid, "environ"); | |
507 | ||
508 | f = fopen(path, "re"); | |
a644184a LP |
509 | if (!f) { |
510 | if (errno == ENOENT) | |
511 | return -ESRCH; | |
0b452006 | 512 | return -errno; |
a644184a | 513 | } |
0b452006 RC |
514 | |
515 | l = strlen(field); | |
516 | r = 0; | |
517 | ||
518 | do { | |
519 | char line[LINE_MAX]; | |
520 | unsigned i; | |
521 | ||
522 | for (i = 0; i < sizeof(line)-1; i++) { | |
523 | int c; | |
524 | ||
525 | c = getc(f); | |
526 | if (_unlikely_(c == EOF)) { | |
527 | done = true; | |
528 | break; | |
529 | } else if (c == 0) | |
530 | break; | |
531 | ||
532 | line[i] = c; | |
533 | } | |
534 | line[i] = 0; | |
535 | ||
536 | if (memcmp(line, field, l) == 0 && line[l] == '=') { | |
537 | value = strdup(line + l + 1); | |
538 | if (!value) | |
539 | return -ENOMEM; | |
540 | ||
541 | r = 1; | |
542 | break; | |
543 | } | |
544 | ||
545 | } while (!done); | |
546 | ||
547 | *_value = value; | |
548 | return r; | |
549 | } | |
550 | ||
551 | bool pid_is_unwaited(pid_t pid) { | |
552 | /* Checks whether a PID is still valid at all, including a zombie */ | |
553 | ||
554 | if (pid <= 0) | |
555 | return false; | |
556 | ||
557 | if (kill(pid, 0) >= 0) | |
558 | return true; | |
559 | ||
560 | return errno != ESRCH; | |
561 | } | |
562 | ||
563 | bool pid_is_alive(pid_t pid) { | |
564 | int r; | |
565 | ||
566 | /* Checks whether a PID is still valid and not a zombie */ | |
567 | ||
568 | if (pid <= 0) | |
569 | return false; | |
570 | ||
571 | r = get_process_state(pid); | |
a644184a | 572 | if (r == -ESRCH || r == 'Z') |
0b452006 RC |
573 | return false; |
574 | ||
575 | return true; | |
576 | } |