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-rw-r--r--util-linux/mdev.c558
1 files changed, 341 insertions, 217 deletions
diff --git a/util-linux/mdev.c b/util-linux/mdev.c
index c56741b08..0b3e06cf1 100644
--- a/util-linux/mdev.c
+++ b/util-linux/mdev.c
@@ -168,9 +168,29 @@
168 * This happens regardless of /sys/class/.../dev existence. 168 * This happens regardless of /sys/class/.../dev existence.
169 */ 169 */
170 170
171struct rule {
172 bool keep_matching;
173 bool regex_compiled;
174 bool regex_has_slash;
175 mode_t mode;
176 int maj, min0, min1;
177 struct bb_uidgid_t ugid;
178 char *envvar;
179 char *ren_mov;
180 IF_FEATURE_MDEV_EXEC(char *r_cmd;)
181 regex_t match;
182};
183
171struct globals { 184struct globals {
172 int root_major, root_minor; 185 int root_major, root_minor;
173 char *subsystem; 186 char *subsystem;
187#if ENABLE_FEATURE_MDEV_CONF
188 const char *filename;
189 parser_t *parser;
190 struct rule **rule_vec;
191 unsigned rule_idx;
192#endif
193 struct rule cur_rule;
174} FIX_ALIASING; 194} FIX_ALIASING;
175#define G (*(struct globals*)&bb_common_bufsiz1) 195#define G (*(struct globals*)&bb_common_bufsiz1)
176#define INIT_G() do { } while (0) 196#define INIT_G() do { } while (0)
@@ -182,6 +202,164 @@ struct globals {
182/* We use additional 64+ bytes in make_device() */ 202/* We use additional 64+ bytes in make_device() */
183#define SCRATCH_SIZE 80 203#define SCRATCH_SIZE 80
184 204
205#if 0
206# define dbg(...) bb_error_msg(__VA_ARGS__)
207#else
208# define dbg(...) ((void)0)
209#endif
210
211
212#if ENABLE_FEATURE_MDEV_CONF
213
214static void make_default_cur_rule(void)
215{
216 memset(&G.cur_rule, 0, sizeof(G.cur_rule));
217 G.cur_rule.maj = -1; /* "not a @major,minor rule" */
218 G.cur_rule.mode = 0660;
219}
220
221static void clean_up_cur_rule(void)
222{
223 free(G.cur_rule.envvar);
224 if (G.cur_rule.regex_compiled)
225 regfree(&G.cur_rule.match);
226 free(G.cur_rule.ren_mov);
227 IF_FEATURE_MDEV_EXEC(free(G.cur_rule.r_cmd);)
228 make_default_cur_rule();
229}
230
231static void parse_next_rule(void)
232{
233 /* Note: on entry, G.cur_rule is set to default */
234 while (1) {
235 char *tokens[4];
236 char *val;
237
238 if (!config_read(G.parser, tokens, 4, 3, "# \t", PARSE_NORMAL))
239 break;
240
241 /* Fields: [-]regex uid:gid mode [alias] [cmd] */
242 dbg("token1:'%s'", tokens[1]);
243
244 /* 1st field */
245 val = tokens[0];
246 G.cur_rule.keep_matching = ('-' == val[0]);
247 val += G.cur_rule.keep_matching; /* swallow leading dash */
248 if (val[0] == '@') {
249 /* @major,minor[-minor2] */
250 /* (useful when name is ambiguous:
251 * "/sys/class/usb/lp0" and
252 * "/sys/class/printer/lp0")
253 */
254 int sc = sscanf(val, "@%u,%u-%u", &G.cur_rule.maj, &G.cur_rule.min0, &G.cur_rule.min1);
255 if (sc < 2 || G.cur_rule.maj < 0) {
256 bb_error_msg("bad @maj,min on line %d", G.parser->lineno);
257 goto next_rule;
258 }
259 if (sc == 2)
260 G.cur_rule.min1 = G.cur_rule.min0;
261 } else {
262 if (val[0] == '$') {
263 char *eq = strchr(++val, '=');
264 if (!eq) {
265 bb_error_msg("bad $envvar=regex on line %d", G.parser->lineno);
266 goto next_rule;
267 }
268 G.cur_rule.envvar = xstrndup(val, eq - val);
269 val = eq + 1;
270 }
271 xregcomp(&G.cur_rule.match, val, REG_EXTENDED);
272 G.cur_rule.regex_compiled = 1;
273 G.cur_rule.regex_has_slash = (strchr(val, '/') != NULL);
274 }
275
276 /* 2nd field: uid:gid - device ownership */
277 if (get_uidgid(&G.cur_rule.ugid, tokens[1], /*allow_numeric:*/ 1) == 0) {
278 bb_error_msg("unknown user/group '%s' on line %d", tokens[1], G.parser->lineno);
279 goto next_rule;
280 }
281
282 /* 3rd field: mode - device permissions */
283 bb_parse_mode(tokens[2], &G.cur_rule.mode);
284
285 /* 4th field (opt): ">|=alias" or "!" to not create the node */
286 val = tokens[3];
287 if (ENABLE_FEATURE_MDEV_RENAME && val && strchr(">=!", val[0])) {
288 char *s = skip_non_whitespace(val);
289 G.cur_rule.ren_mov = xstrndup(val, s - val);
290 val = skip_whitespace(s);
291 }
292
293 if (ENABLE_FEATURE_MDEV_EXEC && val && val[0]) {
294 const char *s = "$@*";
295 const char *s2 = strchr(s, val[0]);
296 if (!s2) {
297 bb_error_msg("bad line %u", G.parser->lineno);
298 goto next_rule;
299 }
300 IF_FEATURE_MDEV_EXEC(G.cur_rule.r_cmd = xstrdup(val);)
301 }
302
303 return;
304 next_rule:
305 clean_up_cur_rule();
306 } /* while (config_read) */
307
308 dbg("config_close(G.parser)");
309 config_close(G.parser);
310 G.parser = NULL;
311
312 return;
313}
314
315/* If mdev -s, we remember rules in G.rule_vec[].
316 * Otherwise, there is no point in doing it, and we just
317 * save only one parsed rule in G.cur_rule.
318 */
319static const struct rule *next_rule(void)
320{
321 struct rule *rule;
322
323 /* Open conf file if we didn't do it yet */
324 if (!G.parser && G.filename) {
325 dbg("config_open('%s')", G.filename);
326 G.parser = config_open2(G.filename, fopen_for_read);
327 G.filename = NULL;
328 }
329
330 if (G.rule_vec) {
331 /* mdev -s */
332 /* Do we have rule parsed already? */
333 if (G.rule_vec[G.rule_idx]) {
334 dbg("< G.rule_vec[G.rule_idx:%d]=%p", G.rule_idx, G.rule_vec[G.rule_idx]);
335 return G.rule_vec[G.rule_idx++];
336 }
337 make_default_cur_rule();
338 } else {
339 /* not mdev -s */
340 clean_up_cur_rule();
341 }
342
343 /* Parse one more rule if file isn't fully read */
344 rule = &G.cur_rule;
345 if (G.parser) {
346 parse_next_rule();
347 if (G.rule_vec) { /* mdev -s */
348 rule = memcpy(xmalloc(sizeof(G.cur_rule)), &G.cur_rule, sizeof(G.cur_rule));
349 G.rule_vec = xrealloc_vector(G.rule_vec, 4, G.rule_idx);
350 G.rule_vec[G.rule_idx++] = rule;
351 dbg("> G.rule_vec[G.rule_idx:%d]=%p", G.rule_idx, G.rule_vec[G.rule_idx]);
352 }
353 }
354
355 return rule;
356}
357
358#else
359
360# define next_rule() (&G.cur_rule)
361
362#endif
185 363
186/* Builds an alias path. 364/* Builds an alias path.
187 * This function potentionally reallocates the alias parameter. 365 * This function potentionally reallocates the alias parameter.
@@ -218,8 +396,8 @@ static void make_device(char *path, int delete)
218{ 396{
219 char *device_name, *subsystem_slash_devname; 397 char *device_name, *subsystem_slash_devname;
220 int major, minor, type, len; 398 int major, minor, type, len;
221 mode_t mode; 399
222 parser_t *parser; 400 dbg("%s('%s', delete:%d)", __func__, path, delete);
223 401
224 /* Try to read major/minor string. Note that the kernel puts \n after 402 /* Try to read major/minor string. Note that the kernel puts \n after
225 * the data, so we don't need to worry about null terminating the string 403 * the data, so we don't need to worry about null terminating the string
@@ -272,246 +450,184 @@ static void make_device(char *path, int delete)
272 path = subsystem_slash_devname; 450 path = subsystem_slash_devname;
273 } 451 }
274 452
275 /* If we have config file, look up user settings */ 453#if ENABLE_FEATURE_MDEV_CONF
276 if (ENABLE_FEATURE_MDEV_CONF) 454 G.rule_idx = 0; /* restart from the beginning (think mdev -s) */
277 parser = config_open2("/etc/mdev.conf", fopen_for_read); 455#endif
278 456 for (;;) {
279 do { 457 const char *str_to_match;
280 int keep_matching; 458 regmatch_t off[1 + 9 * ENABLE_FEATURE_MDEV_RENAME_REGEXP];
281 struct bb_uidgid_t ugid; 459 char *command;
282 char *tokens[4]; 460 char *alias;
283 char *command = NULL;
284 char *alias = NULL;
285 char aliaslink = aliaslink; /* for compiler */ 461 char aliaslink = aliaslink; /* for compiler */
462 const char *node_name;
463 const struct rule *rule;
286 464
287 /* Defaults in case we won't match any line */ 465 str_to_match = "";
288 ugid.uid = ugid.gid = 0; 466
289 keep_matching = 0; 467 rule = next_rule();
290 mode = 0660; 468
291 469#if ENABLE_FEATURE_MDEV_CONF
292 if (ENABLE_FEATURE_MDEV_CONF 470 if (rule->maj >= 0) { /* @maj,min rule */
293 && config_read(parser, tokens, 4, 3, "# \t", PARSE_NORMAL) 471 if (major != rule->maj)
294 ) { 472 continue;
295 char *val; 473 if (minor < rule->min0 || minor > rule->min1)
296 char *str_to_match; 474 continue;
297 regmatch_t off[1 + 9 * ENABLE_FEATURE_MDEV_RENAME_REGEXP]; 475 memset(off, 0, sizeof(off));
298 476 goto rule_matches;
299 val = tokens[0]; 477 }
300 keep_matching = ('-' == val[0]); 478 if (rule->envvar) { /* $envvar=regex rule */
301 val += keep_matching; /* swallow leading dash */ 479 str_to_match = getenv(rule->envvar);
302 480 dbg("getenv('%s'):'%s'", rule->envvar, str_to_match);
303 /* Match against either "subsystem/device_name" 481 if (!str_to_match)
304 * or "device_name" alone */ 482 continue;
305 str_to_match = strchr(val, '/') ? path : device_name; 483 } else {
306 484 /* regex to match [subsystem/]device_name */
307 /* Fields: regex uid:gid mode [alias] [cmd] */ 485 str_to_match = (rule->regex_has_slash ? path : device_name);
308 486 }
309 if (val[0] == '@') { 487
310 /* @major,minor[-minor2] */ 488 if (rule->regex_compiled) {
311 /* (useful when name is ambiguous: 489 int regex_match = regexec(&rule->match, str_to_match, ARRAY_SIZE(off), off, 0);
312 * "/sys/class/usb/lp0" and 490 dbg("regex_match for '%s':%d", str_to_match, regex_match);
313 * "/sys/class/printer/lp0") */ 491 //bb_error_msg("matches:");
314 int cmaj, cmin0, cmin1, sc; 492 //for (int i = 0; i < ARRAY_SIZE(off); i++) {
315 if (major < 0) 493 // if (off[i].rm_so < 0) continue;
316 continue; /* no dev, no match */ 494 // bb_error_msg("match %d: '%.*s'\n", i,
317 sc = sscanf(val, "@%u,%u-%u", &cmaj, &cmin0, &cmin1); 495 // (int)(off[i].rm_eo - off[i].rm_so),
318 if (sc < 1 496 // device_name + off[i].rm_so);
319 || major != cmaj 497 //}
320 || (sc == 2 && minor != cmin0) 498
321 || (sc == 3 && (minor < cmin0 || minor > cmin1)) 499 if (regex_match != 0
322 ) { 500 /* regexec returns whole pattern as "range" 0 */
323 continue; /* this line doesn't match */ 501 || off[0].rm_so != 0
324 } 502 || (int)off[0].rm_eo != (int)strlen(str_to_match)
325 goto line_matches; 503 ) {
326 } 504 continue; /* this rule doesn't match */
327 if (val[0] == '$') {
328 /* regex to match an environment variable */
329 char *eq = strchr(++val, '=');
330 if (!eq)
331 continue;
332 *eq = '\0';
333 str_to_match = getenv(val);
334 if (!str_to_match)
335 continue;
336 str_to_match -= strlen(val) + 1;
337 *eq = '=';
338 } 505 }
339 /* else: regex to match [subsystem/]device_name */ 506 }
340 507 /* else: it's final implicit "match-all" rule */
341 { 508#endif
342 regex_t match; 509
343 int result; 510 rule_matches:
344 511 dbg("rule matched");
345 xregcomp(&match, val, REG_EXTENDED); 512
346 result = regexec(&match, str_to_match, ARRAY_SIZE(off), off, 0); 513 /* Build alias name */
347 regfree(&match); 514 alias = NULL;
348 //bb_error_msg("matches:"); 515 if (ENABLE_FEATURE_MDEV_RENAME && rule->ren_mov) {
349 //for (int i = 0; i < ARRAY_SIZE(off); i++) { 516 aliaslink = rule->ren_mov[0];
350 // if (off[i].rm_so < 0) continue; 517 if (aliaslink == '!') {
351 // bb_error_msg("match %d: '%.*s'\n", i, 518 /* "!": suppress node creation/deletion */
352 // (int)(off[i].rm_eo - off[i].rm_so), 519 major = -2;
353 // device_name + off[i].rm_so);
354 //}
355
356 /* If no match, skip rest of line */
357 /* (regexec returns whole pattern as "range" 0) */
358 if (result
359 || off[0].rm_so
360 || ((int)off[0].rm_eo != (int)strlen(str_to_match))
361 ) {
362 continue; /* this line doesn't match */
363 }
364 } 520 }
365 line_matches: 521 else if (aliaslink == '>' || aliaslink == '=') {
366 /* This line matches. Stop parsing after parsing 522 if (ENABLE_FEATURE_MDEV_RENAME_REGEXP) {
367 * the rest the line unless keep_matching == 1 */ 523 char *s;
368 524 char *p;
369 /* 2nd field: uid:gid - device ownership */ 525 unsigned n;
370 if (get_uidgid(&ugid, tokens[1], /*allow_numeric:*/ 1) == 0) 526
371 bb_error_msg("unknown user/group %s on line %d", tokens[1], parser->lineno); 527 /* substitute %1..9 with off[1..9], if any */
372 528 n = 0;
373 /* 3rd field: mode - device permissions */ 529 s = rule->ren_mov;
374 bb_parse_mode(tokens[2], &mode); 530 while (*s)
375 531 if (*s++ == '%')
376 val = tokens[3]; 532 n++;
377 /* 4th field (opt): ">|=alias" or "!" to not create the node */ 533
378 534 p = alias = xzalloc(strlen(rule->ren_mov) + n * strlen(str_to_match));
379 if (ENABLE_FEATURE_MDEV_RENAME && val) { 535 s = rule->ren_mov + 1;
380 char *a, *s, *st; 536 while (*s) {
381 537 *p = *s;
382 a = val; 538 if ('%' == *s) {
383 s = strchrnul(val, ' '); 539 unsigned i = (s[1] - '0');
384 st = strchrnul(val, '\t'); 540 if (i <= 9 && off[i].rm_so >= 0) {
385 if (st < s) 541 n = off[i].rm_eo - off[i].rm_so;
386 s = st; 542 strncpy(p, str_to_match + off[i].rm_so, n);
387 st = (s[0] && s[1]) ? s+1 : NULL; 543 p += n - 1;
388 544 s++;
389 aliaslink = a[0];
390 if (aliaslink == '!' && s == a+1) {
391 val = st;
392 /* "!": suppress node creation/deletion */
393 major = -2;
394 }
395 else if (aliaslink == '>' || aliaslink == '=') {
396 val = st;
397 s[0] = '\0';
398 if (ENABLE_FEATURE_MDEV_RENAME_REGEXP) {
399 char *p;
400 unsigned i, n;
401
402 /* substitute %1..9 with off[1..9], if any */
403 n = 0;
404 s = a;
405 while (*s)
406 if (*s++ == '%')
407 n++;
408
409 p = alias = xzalloc(strlen(a) + n * strlen(str_to_match));
410 s = a + 1;
411 while (*s) {
412 *p = *s;
413 if ('%' == *s) {
414 i = (s[1] - '0');
415 if (i <= 9 && off[i].rm_so >= 0) {
416 n = off[i].rm_eo - off[i].rm_so;
417 strncpy(p, str_to_match + off[i].rm_so, n);
418 p += n - 1;
419 s++;
420 }
421 } 545 }
422 p++;
423 s++;
424 } 546 }
425 } else { 547 p++;
426 alias = xstrdup(a + 1); 548 s++;
427 } 549 }
550 } else {
551 alias = xstrdup(rule->ren_mov + 1);
428 } 552 }
429 } 553 }
554 }
555 dbg("alias:'%s'", alias);
430 556
431 if (ENABLE_FEATURE_MDEV_EXEC && val) { 557 command = NULL;
432 const char *s = "$@*"; 558 IF_FEATURE_MDEV_EXEC(command = rule->r_cmd;)
433 const char *s2 = strchr(s, val[0]); 559 if (command) {
434 560 const char *s = "$@*";
435 if (!s2) { 561 const char *s2 = strchr(s, command[0]);
436 bb_error_msg("bad line %u", parser->lineno);
437 if (ENABLE_FEATURE_MDEV_RENAME)
438 free(alias);
439 continue;
440 }
441 562
442 /* Are we running this command now? 563 /* Are we running this command now?
443 * Run $cmd on delete, @cmd on create, *cmd on both 564 * Run $cmd on delete, @cmd on create, *cmd on both
565 */
566 if (s2 - s != delete) {
567 /* We are here if: '*',
568 * or: '@' and delete = 0,
569 * or: '$' and delete = 1
444 */ 570 */
445 if (s2 - s != delete) { 571 command++;
446 /* We are here if: '*', 572 } else {
447 * or: '@' and delete = 0, 573 command = NULL;
448 * or: '$' and delete = 1
449 */
450 command = xstrdup(val + 1);
451 }
452 } 574 }
453 } 575 }
454 576 dbg("command:'%s'", command);
455 /* End of field parsing */
456 577
457 /* "Execute" the line we found */ 578 /* "Execute" the line we found */
458 { 579 node_name = device_name;
459 const char *node_name; 580 if (ENABLE_FEATURE_MDEV_RENAME && alias) {
460 581 node_name = alias = build_alias(alias, device_name);
461 node_name = device_name; 582 dbg("alias2:'%s'", alias);
462 if (ENABLE_FEATURE_MDEV_RENAME && alias) 583 }
463 node_name = alias = build_alias(alias, device_name);
464
465 if (!delete && major >= 0) {
466 if (mknod(node_name, mode | type, makedev(major, minor)) && errno != EEXIST)
467 bb_perror_msg("can't create '%s'", node_name);
468 if (major == G.root_major && minor == G.root_minor)
469 symlink(node_name, "root");
470 if (ENABLE_FEATURE_MDEV_CONF) {
471 chmod(node_name, mode);
472 chown(node_name, ugid.uid, ugid.gid);
473 }
474 if (ENABLE_FEATURE_MDEV_RENAME && alias) {
475 if (aliaslink == '>')
476 symlink(node_name, device_name);
477 }
478 }
479 584
480 if (ENABLE_FEATURE_MDEV_EXEC && command) { 585 if (!delete && major >= 0) {
481 /* setenv will leak memory, use putenv/unsetenv/free */ 586 dbg("mknod('%s',%o,(%d,%d))", node_name, rule->mode | type, major, minor);
482 char *s = xasprintf("%s=%s", "MDEV", node_name); 587 if (mknod(node_name, rule->mode | type, makedev(major, minor)) && errno != EEXIST)
483 char *s1 = xasprintf("%s=%s", "SUBSYSTEM", G.subsystem); 588 bb_perror_msg("can't create '%s'", node_name);
484 putenv(s); 589 if (major == G.root_major && minor == G.root_minor)
485 putenv(s1); 590 symlink(node_name, "root");
486 if (system(command) == -1) 591 if (ENABLE_FEATURE_MDEV_CONF) {
487 bb_perror_msg("can't run '%s'", command); 592 chmod(node_name, rule->mode);
488 bb_unsetenv_and_free(s1); 593 chown(node_name, rule->ugid.uid, rule->ugid.gid);
489 bb_unsetenv_and_free(s);
490 free(command);
491 } 594 }
492 595 if (ENABLE_FEATURE_MDEV_RENAME && alias) {
493 if (delete && major >= -1) { 596 if (aliaslink == '>')
494 if (ENABLE_FEATURE_MDEV_RENAME && alias) { 597 symlink(node_name, device_name);
495 if (aliaslink == '>')
496 unlink(device_name);
497 }
498 unlink(node_name);
499 } 598 }
599 }
500 600
501 if (ENABLE_FEATURE_MDEV_RENAME) 601 if (ENABLE_FEATURE_MDEV_EXEC && command) {
502 free(alias); 602 /* setenv will leak memory, use putenv/unsetenv/free */
603 char *s = xasprintf("%s=%s", "MDEV", node_name);
604 char *s1 = xasprintf("%s=%s", "SUBSYSTEM", G.subsystem);
605 putenv(s);
606 putenv(s1);
607 if (system(command) == -1)
608 bb_perror_msg("can't run '%s'", command);
609 bb_unsetenv_and_free(s1);
610 bb_unsetenv_and_free(s);
503 } 611 }
504 612
613 if (delete && major >= -1) {
614 if (ENABLE_FEATURE_MDEV_RENAME && alias) {
615 if (aliaslink == '>')
616 unlink(device_name);
617 }
618 unlink(node_name);
619 }
620
621 if (ENABLE_FEATURE_MDEV_RENAME)
622 free(alias);
623
505 /* We found matching line. 624 /* We found matching line.
506 * Stop unless it was prefixed with '-' */ 625 * Stop unless it was prefixed with '-'
507 if (ENABLE_FEATURE_MDEV_CONF && !keep_matching) 626 */
627 if (!ENABLE_FEATURE_MDEV_CONF || !rule->keep_matching)
508 break; 628 break;
629 } /* for (;;) */
509 630
510 /* end of "while line is read from /etc/mdev.conf" */
511 } while (ENABLE_FEATURE_MDEV_CONF);
512
513 if (ENABLE_FEATURE_MDEV_CONF)
514 config_close(parser);
515 free(subsystem_slash_devname); 631 free(subsystem_slash_devname);
516} 632}
517 633
@@ -618,6 +734,10 @@ int mdev_main(int argc UNUSED_PARAM, char **argv)
618 734
619 INIT_G(); 735 INIT_G();
620 736
737#if ENABLE_FEATURE_MDEV_CONF
738 G.filename = "/etc/mdev.conf";
739#endif
740
621 /* We can be called as hotplug helper */ 741 /* We can be called as hotplug helper */
622 /* Kernel cannot provide suitable stdio fds for us, do it ourself */ 742 /* Kernel cannot provide suitable stdio fds for us, do it ourself */
623 bb_sanitize_stdio(); 743 bb_sanitize_stdio();
@@ -633,6 +753,10 @@ int mdev_main(int argc UNUSED_PARAM, char **argv)
633 */ 753 */
634 struct stat st; 754 struct stat st;
635 755
756#if ENABLE_FEATURE_MDEV_CONF
757 /* Same as xrealloc_vector(NULL, 4, 0): */
758 G.rule_vec = xzalloc((1 << 4) * sizeof(*G.rule_vec));
759#endif
636 xstat("/", &st); 760 xstat("/", &st);
637 G.root_major = major(st.st_dev); 761 G.root_major = major(st.st_dev);
638 G.root_minor = minor(st.st_dev); 762 G.root_minor = minor(st.st_dev);
generated by cgit v1.2.3-55-g6feb (git 2.39.1) at 2025-03-22 17:50:54 +0000