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1 | /*** | |
2 | This file is part of systemd. | |
3 | ||
4 | Copyright 2012 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 <errno.h> | |
21 | #include <limits.h> | |
22 | #include <stdarg.h> | |
23 | #include <stdlib.h> | |
24 | #include <string.h> | |
25 | #include <unistd.h> | |
26 | ||
27 | #include "alloc-util.h" | |
28 | #include "env-util.h" | |
29 | #include "extract-word.h" | |
30 | #include "macro.h" | |
31 | #include "parse-util.h" | |
32 | #include "string-util.h" | |
33 | #include "strv.h" | |
34 | #include "utf8.h" | |
35 | ||
36 | #define VALID_CHARS_ENV_NAME \ | |
37 | DIGITS LETTERS \ | |
38 | "_" | |
39 | ||
40 | #ifndef ARG_MAX | |
41 | #define ARG_MAX ((size_t) sysconf(_SC_ARG_MAX)) | |
42 | #endif | |
43 | ||
44 | static bool env_name_is_valid_n(const char *e, size_t n) { | |
45 | const char *p; | |
46 | ||
47 | if (!e) | |
48 | return false; | |
49 | ||
50 | if (n <= 0) | |
51 | return false; | |
52 | ||
53 | if (e[0] >= '0' && e[0] <= '9') | |
54 | return false; | |
55 | ||
56 | /* POSIX says the overall size of the environment block cannot | |
57 | * be > ARG_MAX, an individual assignment hence cannot be | |
58 | * either. Discounting the equal sign and trailing NUL this | |
59 | * hence leaves ARG_MAX-2 as longest possible variable | |
60 | * name. */ | |
61 | if (n > ARG_MAX - 2) | |
62 | return false; | |
63 | ||
64 | for (p = e; p < e + n; p++) | |
65 | if (!strchr(VALID_CHARS_ENV_NAME, *p)) | |
66 | return false; | |
67 | ||
68 | return true; | |
69 | } | |
70 | ||
71 | bool env_name_is_valid(const char *e) { | |
72 | if (!e) | |
73 | return false; | |
74 | ||
75 | return env_name_is_valid_n(e, strlen(e)); | |
76 | } | |
77 | ||
78 | bool env_value_is_valid(const char *e) { | |
79 | if (!e) | |
80 | return false; | |
81 | ||
82 | if (!utf8_is_valid(e)) | |
83 | return false; | |
84 | ||
85 | /* bash allows tabs in environment variables, and so should | |
86 | * we */ | |
87 | if (string_has_cc(e, "\t")) | |
88 | return false; | |
89 | ||
90 | /* POSIX says the overall size of the environment block cannot | |
91 | * be > ARG_MAX, an individual assignment hence cannot be | |
92 | * either. Discounting the shortest possible variable name of | |
93 | * length 1, the equal sign and trailing NUL this hence leaves | |
94 | * ARG_MAX-3 as longest possible variable value. */ | |
95 | if (strlen(e) > ARG_MAX - 3) | |
96 | return false; | |
97 | ||
98 | return true; | |
99 | } | |
100 | ||
101 | bool env_assignment_is_valid(const char *e) { | |
102 | const char *eq; | |
103 | ||
104 | eq = strchr(e, '='); | |
105 | if (!eq) | |
106 | return false; | |
107 | ||
108 | if (!env_name_is_valid_n(e, eq - e)) | |
109 | return false; | |
110 | ||
111 | if (!env_value_is_valid(eq + 1)) | |
112 | return false; | |
113 | ||
114 | /* POSIX says the overall size of the environment block cannot | |
115 | * be > ARG_MAX, hence the individual variable assignments | |
116 | * cannot be either, but let's leave room for one trailing NUL | |
117 | * byte. */ | |
118 | if (strlen(e) > ARG_MAX - 1) | |
119 | return false; | |
120 | ||
121 | return true; | |
122 | } | |
123 | ||
124 | bool strv_env_is_valid(char **e) { | |
125 | char **p, **q; | |
126 | ||
127 | STRV_FOREACH(p, e) { | |
128 | size_t k; | |
129 | ||
130 | if (!env_assignment_is_valid(*p)) | |
131 | return false; | |
132 | ||
133 | /* Check if there are duplicate assginments */ | |
134 | k = strcspn(*p, "="); | |
135 | STRV_FOREACH(q, p + 1) | |
136 | if (strneq(*p, *q, k) && (*q)[k] == '=') | |
137 | return false; | |
138 | } | |
139 | ||
140 | return true; | |
141 | } | |
142 | ||
143 | bool strv_env_name_is_valid(char **l) { | |
144 | char **p, **q; | |
145 | ||
146 | STRV_FOREACH(p, l) { | |
147 | if (!env_name_is_valid(*p)) | |
148 | return false; | |
149 | ||
150 | STRV_FOREACH(q, p + 1) | |
151 | if (streq(*p, *q)) | |
152 | return false; | |
153 | } | |
154 | ||
155 | return true; | |
156 | } | |
157 | ||
158 | bool strv_env_name_or_assignment_is_valid(char **l) { | |
159 | char **p, **q; | |
160 | ||
161 | STRV_FOREACH(p, l) { | |
162 | if (!env_assignment_is_valid(*p) && !env_name_is_valid(*p)) | |
163 | return false; | |
164 | ||
165 | STRV_FOREACH(q, p + 1) | |
166 | if (streq(*p, *q)) | |
167 | return false; | |
168 | } | |
169 | ||
170 | return true; | |
171 | } | |
172 | ||
173 | static int env_append(char **r, char ***k, char **a) { | |
174 | assert(r); | |
175 | assert(k); | |
176 | ||
177 | if (!a) | |
178 | return 0; | |
179 | ||
180 | /* Add the entries of a to *k unless they already exist in *r | |
181 | * in which case they are overridden instead. This assumes | |
182 | * there is enough space in the r array. */ | |
183 | ||
184 | for (; *a; a++) { | |
185 | char **j; | |
186 | size_t n; | |
187 | ||
188 | n = strcspn(*a, "="); | |
189 | ||
190 | if ((*a)[n] == '=') | |
191 | n++; | |
192 | ||
193 | for (j = r; j < *k; j++) | |
194 | if (strneq(*j, *a, n)) | |
195 | break; | |
196 | ||
197 | if (j >= *k) | |
198 | (*k)++; | |
199 | else | |
200 | free(*j); | |
201 | ||
202 | *j = strdup(*a); | |
203 | if (!*j) | |
204 | return -ENOMEM; | |
205 | } | |
206 | ||
207 | return 0; | |
208 | } | |
209 | ||
210 | char **strv_env_merge(unsigned n_lists, ...) { | |
211 | size_t n = 0; | |
212 | char **l, **k, **r; | |
213 | va_list ap; | |
214 | unsigned i; | |
215 | ||
216 | /* Merges an arbitrary number of environment sets */ | |
217 | ||
218 | va_start(ap, n_lists); | |
219 | for (i = 0; i < n_lists; i++) { | |
220 | l = va_arg(ap, char**); | |
221 | n += strv_length(l); | |
222 | } | |
223 | va_end(ap); | |
224 | ||
225 | r = new(char*, n+1); | |
226 | if (!r) | |
227 | return NULL; | |
228 | ||
229 | k = r; | |
230 | ||
231 | va_start(ap, n_lists); | |
232 | for (i = 0; i < n_lists; i++) { | |
233 | l = va_arg(ap, char**); | |
234 | if (env_append(r, &k, l) < 0) | |
235 | goto fail; | |
236 | } | |
237 | va_end(ap); | |
238 | ||
239 | *k = NULL; | |
240 | ||
241 | return r; | |
242 | ||
243 | fail: | |
244 | va_end(ap); | |
245 | strv_free(r); | |
246 | ||
247 | return NULL; | |
248 | } | |
249 | ||
250 | _pure_ static bool env_match(const char *t, const char *pattern) { | |
251 | assert(t); | |
252 | assert(pattern); | |
253 | ||
254 | /* pattern a matches string a | |
255 | * a matches a= | |
256 | * a matches a=b | |
257 | * a= matches a= | |
258 | * a=b matches a=b | |
259 | * a= does not match a | |
260 | * a=b does not match a= | |
261 | * a=b does not match a | |
262 | * a=b does not match a=c */ | |
263 | ||
264 | if (streq(t, pattern)) | |
265 | return true; | |
266 | ||
267 | if (!strchr(pattern, '=')) { | |
268 | size_t l = strlen(pattern); | |
269 | ||
270 | return strneq(t, pattern, l) && t[l] == '='; | |
271 | } | |
272 | ||
273 | return false; | |
274 | } | |
275 | ||
276 | char **strv_env_delete(char **x, unsigned n_lists, ...) { | |
277 | size_t n, i = 0; | |
278 | char **k, **r; | |
279 | va_list ap; | |
280 | ||
281 | /* Deletes every entry from x that is mentioned in the other | |
282 | * string lists */ | |
283 | ||
284 | n = strv_length(x); | |
285 | ||
286 | r = new(char*, n+1); | |
287 | if (!r) | |
288 | return NULL; | |
289 | ||
290 | STRV_FOREACH(k, x) { | |
291 | unsigned v; | |
292 | ||
293 | va_start(ap, n_lists); | |
294 | for (v = 0; v < n_lists; v++) { | |
295 | char **l, **j; | |
296 | ||
297 | l = va_arg(ap, char**); | |
298 | STRV_FOREACH(j, l) | |
299 | if (env_match(*k, *j)) | |
300 | goto skip; | |
301 | } | |
302 | va_end(ap); | |
303 | ||
304 | r[i] = strdup(*k); | |
305 | if (!r[i]) { | |
306 | strv_free(r); | |
307 | return NULL; | |
308 | } | |
309 | ||
310 | i++; | |
311 | continue; | |
312 | ||
313 | skip: | |
314 | va_end(ap); | |
315 | } | |
316 | ||
317 | r[i] = NULL; | |
318 | ||
319 | assert(i <= n); | |
320 | ||
321 | return r; | |
322 | } | |
323 | ||
324 | char **strv_env_unset(char **l, const char *p) { | |
325 | ||
326 | char **f, **t; | |
327 | ||
328 | if (!l) | |
329 | return NULL; | |
330 | ||
331 | assert(p); | |
332 | ||
333 | /* Drops every occurrence of the env var setting p in the | |
334 | * string list. Edits in-place. */ | |
335 | ||
336 | for (f = t = l; *f; f++) { | |
337 | ||
338 | if (env_match(*f, p)) { | |
339 | free(*f); | |
340 | continue; | |
341 | } | |
342 | ||
343 | *(t++) = *f; | |
344 | } | |
345 | ||
346 | *t = NULL; | |
347 | return l; | |
348 | } | |
349 | ||
350 | char **strv_env_unset_many(char **l, ...) { | |
351 | ||
352 | char **f, **t; | |
353 | ||
354 | if (!l) | |
355 | return NULL; | |
356 | ||
357 | /* Like strv_env_unset() but applies many at once. Edits in-place. */ | |
358 | ||
359 | for (f = t = l; *f; f++) { | |
360 | bool found = false; | |
361 | const char *p; | |
362 | va_list ap; | |
363 | ||
364 | va_start(ap, l); | |
365 | ||
366 | while ((p = va_arg(ap, const char*))) { | |
367 | if (env_match(*f, p)) { | |
368 | found = true; | |
369 | break; | |
370 | } | |
371 | } | |
372 | ||
373 | va_end(ap); | |
374 | ||
375 | if (found) { | |
376 | free(*f); | |
377 | continue; | |
378 | } | |
379 | ||
380 | *(t++) = *f; | |
381 | } | |
382 | ||
383 | *t = NULL; | |
384 | return l; | |
385 | } | |
386 | ||
387 | char **strv_env_set(char **x, const char *p) { | |
388 | ||
389 | char **k, **r; | |
390 | char* m[2] = { (char*) p, NULL }; | |
391 | ||
392 | /* Overrides the env var setting of p, returns a new copy */ | |
393 | ||
394 | r = new(char*, strv_length(x)+2); | |
395 | if (!r) | |
396 | return NULL; | |
397 | ||
398 | k = r; | |
399 | if (env_append(r, &k, x) < 0) | |
400 | goto fail; | |
401 | ||
402 | if (env_append(r, &k, m) < 0) | |
403 | goto fail; | |
404 | ||
405 | *k = NULL; | |
406 | ||
407 | return r; | |
408 | ||
409 | fail: | |
410 | strv_free(r); | |
411 | return NULL; | |
412 | } | |
413 | ||
414 | char *strv_env_get_n(char **l, const char *name, size_t k) { | |
415 | char **i; | |
416 | ||
417 | assert(name); | |
418 | ||
419 | if (k <= 0) | |
420 | return NULL; | |
421 | ||
422 | STRV_FOREACH(i, l) | |
423 | if (strneq(*i, name, k) && | |
424 | (*i)[k] == '=') | |
425 | return *i + k + 1; | |
426 | ||
427 | return NULL; | |
428 | } | |
429 | ||
430 | char *strv_env_get(char **l, const char *name) { | |
431 | assert(name); | |
432 | ||
433 | return strv_env_get_n(l, name, strlen(name)); | |
434 | } | |
435 | ||
436 | char **strv_env_clean_with_callback(char **e, void (*invalid_callback)(const char *p, void *userdata), void *userdata) { | |
437 | char **p, **q; | |
438 | int k = 0; | |
439 | ||
440 | STRV_FOREACH(p, e) { | |
441 | size_t n; | |
442 | bool duplicate = false; | |
443 | ||
444 | if (!env_assignment_is_valid(*p)) { | |
445 | if (invalid_callback) | |
446 | invalid_callback(*p, userdata); | |
447 | free(*p); | |
448 | continue; | |
449 | } | |
450 | ||
451 | n = strcspn(*p, "="); | |
452 | STRV_FOREACH(q, p + 1) | |
453 | if (strneq(*p, *q, n) && (*q)[n] == '=') { | |
454 | duplicate = true; | |
455 | break; | |
456 | } | |
457 | ||
458 | if (duplicate) { | |
459 | free(*p); | |
460 | continue; | |
461 | } | |
462 | ||
463 | e[k++] = *p; | |
464 | } | |
465 | ||
466 | if (e) | |
467 | e[k] = NULL; | |
468 | ||
469 | return e; | |
470 | } | |
471 | ||
472 | char *replace_env(const char *format, char **env) { | |
473 | enum { | |
474 | WORD, | |
475 | CURLY, | |
476 | VARIABLE | |
477 | } state = WORD; | |
478 | ||
479 | const char *e, *word = format; | |
480 | char *r = NULL, *k; | |
481 | ||
482 | assert(format); | |
483 | ||
484 | for (e = format; *e; e ++) { | |
485 | ||
486 | switch (state) { | |
487 | ||
488 | case WORD: | |
489 | if (*e == '$') | |
490 | state = CURLY; | |
491 | break; | |
492 | ||
493 | case CURLY: | |
494 | if (*e == '{') { | |
495 | k = strnappend(r, word, e-word-1); | |
496 | if (!k) | |
497 | goto fail; | |
498 | ||
499 | free(r); | |
500 | r = k; | |
501 | ||
502 | word = e-1; | |
503 | state = VARIABLE; | |
504 | ||
505 | } else if (*e == '$') { | |
506 | k = strnappend(r, word, e-word); | |
507 | if (!k) | |
508 | goto fail; | |
509 | ||
510 | free(r); | |
511 | r = k; | |
512 | ||
513 | word = e+1; | |
514 | state = WORD; | |
515 | } else | |
516 | state = WORD; | |
517 | break; | |
518 | ||
519 | case VARIABLE: | |
520 | if (*e == '}') { | |
521 | const char *t; | |
522 | ||
523 | t = strempty(strv_env_get_n(env, word+2, e-word-2)); | |
524 | ||
525 | k = strappend(r, t); | |
526 | if (!k) | |
527 | goto fail; | |
528 | ||
529 | free(r); | |
530 | r = k; | |
531 | ||
532 | word = e+1; | |
533 | state = WORD; | |
534 | } | |
535 | break; | |
536 | } | |
537 | } | |
538 | ||
539 | k = strnappend(r, word, e-word); | |
540 | if (!k) | |
541 | goto fail; | |
542 | ||
543 | free(r); | |
544 | return k; | |
545 | ||
546 | fail: | |
547 | free(r); | |
548 | return NULL; | |
549 | } | |
550 | ||
551 | char **replace_env_argv(char **argv, char **env) { | |
552 | char **ret, **i; | |
553 | unsigned k = 0, l = 0; | |
554 | ||
555 | l = strv_length(argv); | |
556 | ||
557 | ret = new(char*, l+1); | |
558 | if (!ret) | |
559 | return NULL; | |
560 | ||
561 | STRV_FOREACH(i, argv) { | |
562 | ||
563 | /* If $FOO appears as single word, replace it by the split up variable */ | |
564 | if ((*i)[0] == '$' && (*i)[1] != '{' && (*i)[1] != '$') { | |
565 | char *e; | |
566 | char **w, **m = NULL; | |
567 | unsigned q; | |
568 | ||
569 | e = strv_env_get(env, *i+1); | |
570 | if (e) { | |
571 | int r; | |
572 | ||
573 | r = strv_split_extract(&m, e, WHITESPACE, EXTRACT_RELAX|EXTRACT_QUOTES); | |
574 | if (r < 0) { | |
575 | ret[k] = NULL; | |
576 | strv_free(ret); | |
577 | return NULL; | |
578 | } | |
579 | } else | |
580 | m = NULL; | |
581 | ||
582 | q = strv_length(m); | |
583 | l = l + q - 1; | |
584 | ||
585 | w = realloc(ret, sizeof(char*) * (l+1)); | |
586 | if (!w) { | |
587 | ret[k] = NULL; | |
588 | strv_free(ret); | |
589 | strv_free(m); | |
590 | return NULL; | |
591 | } | |
592 | ||
593 | ret = w; | |
594 | if (m) { | |
595 | memcpy(ret + k, m, q * sizeof(char*)); | |
596 | free(m); | |
597 | } | |
598 | ||
599 | k += q; | |
600 | continue; | |
601 | } | |
602 | ||
603 | /* If ${FOO} appears as part of a word, replace it by the variable as-is */ | |
604 | ret[k] = replace_env(*i, env); | |
605 | if (!ret[k]) { | |
606 | strv_free(ret); | |
607 | return NULL; | |
608 | } | |
609 | k++; | |
610 | } | |
611 | ||
612 | ret[k] = NULL; | |
613 | return ret; | |
614 | } | |
615 | ||
616 | int getenv_bool(const char *p) { | |
617 | const char *e; | |
618 | ||
619 | e = getenv(p); | |
620 | if (!e) | |
621 | return -ENXIO; | |
622 | ||
623 | return parse_boolean(e); | |
624 | } |