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