1 /*-
2 * Copyright (c) 2002 Dima Dorfman.
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 *
26 * $FreeBSD: releng/5.0/sys/fs/devfs/devfs_rule.c 105212 2002-10-16 08:04:11Z phk $
27 */
28
29 /*
30 * DEVFS ruleset implementation.
31 *
32 * A note on terminology: To "run" a rule on a dirent is to take the
33 * prescribed action; to "apply" a rule is to check whether it matches
34 * a dirent and run if if it does.
35 *
36 * A note on locking: Only foreign entry points (non-static functions)
37 * should deal with locking. Everything else assumes we already hold
38 * the required kind of lock.
39 *
40 * A note on namespace: devfs_rules_* are the non-static functions for
41 * the entire "ruleset" subsystem, devfs_rule_* are the static
42 * functions that operate on rules, and devfs_ruleset_* are the static
43 * functions that operate on rulesets. The line between the last two
44 * isn't always clear, but the guideline is still useful.
45 *
46 * A note on "special" identifiers: Ruleset 0 is the NULL, or empty,
47 * ruleset; it cannot be deleted or changed in any way. This may be
48 * assumed inside the code; e.g., a ruleset of 0 may be interpeted to
49 * mean "no ruleset". The interpretation of rule 0 is
50 * command-dependent, but in no case is there a real rule with number
51 * 0.
52 *
53 * A note on errno codes: To make it easier for the userland to tell
54 * what went wrong, we sometimes use errno codes that are not entirely
55 * appropriate for the error but that would be less ambiguous than the
56 * appropriate "generic" code. For example, when we can't find a
57 * ruleset, we return ESRCH instead of ENOENT (except in
58 * DEVFSIO_{R,S}GETNEXT, where a nonexistent ruleset means "end of
59 * list", and the userland expects ENOENT to be this indicator); this
60 * way, when an operation fails, it's clear that what couldn't be
61 * found is a ruleset and not a rule (well, it's clear to those who
62 * know the convention).
63 */
64
65 #include "opt_devfs.h"
66 #ifndef NODEVFS
67
68 #include <sys/param.h>
69 #include <sys/systm.h>
70 #include <sys/conf.h>
71 #include <sys/kernel.h>
72 #include <sys/malloc.h>
73 #include <sys/dirent.h>
74 #include <sys/vnode.h>
75 #include <sys/mount.h>
76 #include <sys/ioccom.h>
77
78 #include <fs/devfs/devfs.h>
79
80
81 /*
82 * Kernel version of devfs_rule.
83 */
84 struct devfs_krule {
85 SLIST_ENTRY(devfs_krule) dk_list;
86 struct devfs_ruleset *dk_ruleset;
87 struct devfs_rule dk_rule;
88 };
89
90 /*
91 * Structure to describe a ruleset.
92 */
93 struct devfs_ruleset {
94 SLIST_ENTRY(devfs_ruleset) ds_list;
95 devfs_rsnum ds_number;
96 SLIST_HEAD(, devfs_krule) ds_rules;
97 int ds_refcount;
98 int ds_flags;
99 #define DS_IMMUTABLE 0x001
100 int ds_running;
101 };
102
103 static devfs_rid devfs_rid_input(devfs_rid rid, struct devfs_mount *dm);
104
105 static void devfs_rule_applyde(struct devfs_krule *dk,struct devfs_dirent *de);
106 static void devfs_rule_applyde_recursive(struct devfs_krule *dk,
107 struct devfs_dirent *de);
108 static void devfs_rule_applydm(struct devfs_krule *dk, struct devfs_mount *dm);
109 static int devfs_rule_autonumber(struct devfs_ruleset *ds, devfs_rnum *rnp);
110 static struct devfs_krule *devfs_rule_byid(devfs_rid rid);
111 static int devfs_rule_delete(struct devfs_krule **dkp);
112 static dev_t devfs_rule_getdev(struct devfs_dirent *de);
113 static int devfs_rule_input(struct devfs_rule *dr, struct devfs_mount *dm);
114 static int devfs_rule_insert(struct devfs_rule *dr);
115 static int devfs_rule_match(struct devfs_krule *dk, struct devfs_dirent *de);
116 static int devfs_rule_matchpath(struct devfs_krule *dk,
117 struct devfs_dirent *de);
118 static void devfs_rule_run(struct devfs_krule *dk, struct devfs_dirent *de);
119
120 static void devfs_ruleset_applyde(struct devfs_ruleset *ds,
121 struct devfs_dirent *de);
122 static void devfs_ruleset_applydm(struct devfs_ruleset *ds,
123 struct devfs_mount *dm);
124 static struct devfs_ruleset *devfs_ruleset_bynum(devfs_rsnum rsnum);
125 static struct devfs_ruleset *devfs_ruleset_create(devfs_rsnum rsnum);
126 static void devfs_ruleset_destroy(struct devfs_ruleset **dsp);
127 static void devfs_ruleset_reap(struct devfs_ruleset **dsp);
128 static int devfs_ruleset_use(devfs_rsnum rsnum, struct devfs_mount *dm);
129
130 static SLIST_HEAD(, devfs_ruleset) devfs_rulesets;
131
132 /*
133 * Called to apply the proper rules for de before the latter can be
134 * exposed to the userland. This should be called with an exclusive
135 * lock on dm in case we need to run anything.
136 */
137 void
138 devfs_rules_apply(struct devfs_mount *dm, struct devfs_dirent *de)
139 {
140 struct devfs_ruleset *ds;
141
142 ds = devfs_ruleset_bynum(dm->dm_ruleset);
143 KASSERT(ds != NULL, ("mount-point has NULL ruleset"));
144 devfs_ruleset_applyde(ds, de);
145 }
146
147 /*
148 * Rule subsystem SYSINIT hook.
149 */
150 void
151 devfs_rules_init(void)
152 {
153 struct devfs_ruleset *ds;
154
155 SLIST_INIT(&devfs_rulesets);
156
157 ds = devfs_ruleset_create(0);
158 ds->ds_flags |= DS_IMMUTABLE;
159 ds->ds_refcount = 1; /* Prevent reaping. */
160 }
161
162 /*
163 * Rule subsystem ioctl hook.
164 */
165 int
166 devfs_rules_ioctl(struct mount *mp, u_long cmd, caddr_t data, struct thread *td)
167 {
168 struct devfs_mount *dm = VFSTODEVFS(mp);
169 struct devfs_ruleset *ds;
170 struct devfs_krule *dk;
171 struct devfs_rule *dr;
172 devfs_rsnum rsnum;
173 devfs_rnum rnum;
174 devfs_rid rid;
175 int error;
176
177 /*
178 * XXX: This returns an error regardless of whether we
179 * actually support the cmd or not.
180 */
181 error = suser(td);
182 if (error != 0)
183 return (error);
184
185 lockmgr(&dm->dm_lock, LK_SHARED, 0, td);
186
187 switch (cmd) {
188 case DEVFSIO_RADD:
189 dr = (struct devfs_rule *)data;
190 error = devfs_rule_input(dr, dm);
191 if (error != 0)
192 goto out;
193 dk = devfs_rule_byid(dr->dr_id);
194 if (dk != NULL) {
195 error = EEXIST;
196 goto out;
197 }
198 lockmgr(&dm->dm_lock, LK_UPGRADE, 0, td);
199 error = devfs_rule_insert(dr);
200 break;
201 case DEVFSIO_RAPPLY:
202 dr = (struct devfs_rule *)data;
203 error = devfs_rule_input(dr, dm);
204 if (error != 0)
205 goto out;
206
207 /*
208 * This is one of many possible hackish
209 * implementations. The primary contender is an
210 * implementation where the rule we read in is
211 * temporarily inserted into some ruleset, perhaps
212 * with a hypothetical DRO_NOAUTO flag so that it
213 * doesn't get used where it isn't intended, and
214 * applied in the normal way. This can be done in the
215 * userland (DEVFSIO_ADD, DEVFSIO_APPLYID,
216 * DEVFSIO_DEL) or in the kernel; either way it breaks
217 * some corner case assumptions in other parts of the
218 * code (not that this implementation doesn't do
219 * that).
220 */
221 if (dr->dr_iacts & DRA_INCSET &&
222 devfs_ruleset_bynum(dr->dr_incset) == NULL) {
223 error = ESRCH;
224 goto out;
225 }
226 dk = malloc(sizeof(*dk), M_TEMP, M_WAITOK | M_ZERO);
227 memcpy(&dk->dk_rule, dr, sizeof(*dr));
228 lockmgr(&dm->dm_lock, LK_UPGRADE, 0, td);
229 devfs_rule_applydm(dk, dm);
230 lockmgr(&dm->dm_lock, LK_DOWNGRADE, 0, td);
231 free(dk, M_TEMP);
232 error = 0;
233 break;
234 case DEVFSIO_RAPPLYID:
235 rid = *(devfs_rid *)data;
236 rid = devfs_rid_input(rid, dm);
237 dk = devfs_rule_byid(rid);
238 if (dk == NULL) {
239 error = ENOENT;
240 goto out;
241 }
242 lockmgr(&dm->dm_lock, LK_UPGRADE, 0, td);
243 devfs_rule_applydm(dk, dm);
244 error = 0;
245 break;
246 case DEVFSIO_RDEL:
247 rid = *(devfs_rid *)data;
248 rid = devfs_rid_input(rid, dm);
249 dk = devfs_rule_byid(rid);
250 if (dk == NULL) {
251 error = ENOENT;
252 goto out;
253 }
254 ds = dk->dk_ruleset;
255 lockmgr(&dm->dm_lock, LK_UPGRADE, 0, td);
256 error = devfs_rule_delete(&dk);
257 devfs_ruleset_reap(&ds);
258 break;
259 case DEVFSIO_RGETNEXT:
260 dr = (struct devfs_rule *)data;
261 error = devfs_rule_input(dr, dm);
262 if (error != 0)
263 goto out;
264 /*
265 * We can't use devfs_rule_byid() here since that
266 * requires the rule specified to exist, but we want
267 * getnext(N) to work whether there is a rule N or not
268 * (specifically, getnext(0) must work, but we should
269 * never have a rule 0 since the add command
270 * interprets 0 to mean "auto-number").
271 */
272 ds = devfs_ruleset_bynum(rid2rsn(dr->dr_id));
273 if (ds == NULL) {
274 error = ENOENT;
275 goto out;
276 }
277 rnum = rid2rn(dr->dr_id);
278 SLIST_FOREACH(dk, &ds->ds_rules, dk_list) {
279 if (rid2rn(dk->dk_rule.dr_id) > rnum)
280 break;
281 }
282 if (dk == NULL) {
283 error = ENOENT;
284 goto out;
285 }
286 memcpy(dr, &dk->dk_rule, sizeof(*dr));
287 error = 0;
288 break;
289 case DEVFSIO_SUSE:
290 rsnum = *(devfs_rsnum *)data;
291 lockmgr(&dm->dm_lock, LK_UPGRADE, 0, td);
292 error = devfs_ruleset_use(rsnum, dm);
293 break;
294 case DEVFSIO_SAPPLY:
295 rsnum = *(devfs_rsnum *)data;
296 rsnum = rid2rsn(devfs_rid_input(mkrid(rsnum, 0), dm));
297 ds = devfs_ruleset_bynum(rsnum);
298 if (ds == NULL) {
299 error = ESRCH;
300 goto out;
301 }
302 lockmgr(&dm->dm_lock, LK_UPGRADE, 0, td);
303 devfs_ruleset_applydm(ds, dm);
304 error = 0;
305 break;
306 case DEVFSIO_SGETNEXT:
307 rsnum = *(devfs_rsnum *)data;
308 SLIST_FOREACH(ds, &devfs_rulesets, ds_list) {
309 if (ds->ds_number > rsnum)
310 break;
311 }
312 if (ds == NULL)
313 error = ENOENT;
314 else {
315 *(devfs_rsnum *)data = ds->ds_number;
316 error = 0;
317 }
318 break;
319 default:
320 error = ENOIOCTL;
321 break;
322 }
323
324 out:
325 lockmgr(&dm->dm_lock, LK_RELEASE, 0, td);
326 return (error);
327 }
328
329 /*
330 * Called to initialize dm_ruleset when there is a new mount-point.
331 */
332 void
333 devfs_rules_newmount(struct devfs_mount *dm, struct thread *td)
334 {
335 struct devfs_ruleset *ds;
336
337 lockmgr(&dm->dm_lock, LK_EXCLUSIVE, 0, td);
338 /*
339 * We can't use devfs_ruleset_use() since it will try to
340 * decrement the refcount for the old ruleset, and there is no
341 * old ruleset. Making some value of ds_ruleset "special" to
342 * mean "don't decrement refcount" is uglier than this.
343 */
344 ds = devfs_ruleset_bynum(0);
345 KASSERT(ds != NULL, ("no ruleset 0"));
346 ++ds->ds_refcount;
347 dm->dm_ruleset = 0;
348 lockmgr(&dm->dm_lock, LK_RELEASE, 0, td);
349 }
350
351 /*
352 * Adjust the rule identifier to use the ruleset of dm if one isn't
353 * explicitly specified.
354 *
355 * Note that after this operation, rid2rsn(rid) might still be 0, and
356 * that's okay; ruleset 0 is a valid ruleset, but when it's read in
357 * from the userland, it means "current ruleset for this mount-point".
358 */
359 static devfs_rid
360 devfs_rid_input(devfs_rid rid, struct devfs_mount *dm)
361 {
362
363 if (rid2rsn(rid) == 0)
364 return (mkrid(dm->dm_ruleset, rid2rn(rid)));
365 else
366 return (rid);
367 }
368
369 /*
370 * Apply dk to de.
371 */
372 static void
373 devfs_rule_applyde(struct devfs_krule *dk, struct devfs_dirent *de)
374 {
375
376 if (devfs_rule_match(dk, de))
377 devfs_rule_run(dk, de);
378 }
379
380 /*
381 * Apply dk to de and everything under de.
382 *
383 * XXX: This method needs a function call for every nested
384 * subdirectory in a devfs mount. If we plan to have many of these,
385 * we might eventually run out of kernel stack space.
386 */
387 static void
388 devfs_rule_applyde_recursive(struct devfs_krule *dk, struct devfs_dirent *de)
389 {
390 struct devfs_dirent *de2;
391
392 /* XXX: Should we apply to ourselves first or last? Does it matter? */
393 TAILQ_FOREACH(de2, &de->de_dlist, de_list) {
394 devfs_rule_applyde_recursive(dk, de2);
395 }
396 devfs_rule_applyde(dk, de);
397 }
398
399 /*
400 * Apply dk to all entires in dm.
401 */
402 static void
403 devfs_rule_applydm(struct devfs_krule *dk, struct devfs_mount *dm)
404 {
405
406 devfs_rule_applyde_recursive(dk, dm->dm_basedir);
407 }
408
409 /*
410 * Automatically select a number for a new rule in ds, and write the
411 * result into rnump.
412 */
413 static int
414 devfs_rule_autonumber(struct devfs_ruleset *ds, devfs_rnum *rnump)
415 {
416 struct devfs_krule *dk;
417
418 /* Find the last rule. */
419 SLIST_FOREACH(dk, &ds->ds_rules, dk_list) {
420 if (SLIST_NEXT(dk, dk_list) == NULL)
421 break;
422 }
423 if (dk == NULL)
424 *rnump = 100;
425 else {
426 *rnump = rid2rn(dk->dk_rule.dr_id) + 100;
427 /* Detect overflow. */
428 if (*rnump < rid2rn(dk->dk_rule.dr_id))
429 return (ERANGE);
430 }
431 KASSERT(devfs_rule_byid(mkrid(ds->ds_number, *rnump)) == NULL,
432 ("autonumbering resulted in an already existing rule"));
433 return (0);
434 }
435
436 /*
437 * Find a krule by id.
438 */
439 static struct devfs_krule *
440 devfs_rule_byid(devfs_rid rid)
441 {
442 struct devfs_ruleset *ds;
443 struct devfs_krule *dk;
444 devfs_rnum rn;
445
446 rn = rid2rn(rid);
447 ds = devfs_ruleset_bynum(rid2rsn(rid));
448 if (ds == NULL)
449 return (NULL);
450 SLIST_FOREACH(dk, &ds->ds_rules, dk_list) {
451 if (rid2rn(dk->dk_rule.dr_id) == rn)
452 return (dk);
453 else if (rid2rn(dk->dk_rule.dr_id) > rn)
454 break;
455 }
456 return (NULL);
457 }
458
459 /*
460 * Remove dkp from any lists it may be on and remove memory associated
461 * with it.
462 */
463 static int
464 devfs_rule_delete(struct devfs_krule **dkp)
465 {
466 struct devfs_krule *dk = *dkp;
467 struct devfs_ruleset *ds;
468
469 if (dk->dk_rule.dr_iacts & DRA_INCSET) {
470 ds = devfs_ruleset_bynum(dk->dk_rule.dr_incset);
471 KASSERT(ds != NULL, ("DRA_INCSET but bad dr_incset"));
472 --ds->ds_refcount;
473 devfs_ruleset_reap(&ds);
474 }
475 SLIST_REMOVE(&dk->dk_ruleset->ds_rules, dk, devfs_krule, dk_list);
476 free(dk, M_DEVFS);
477 *dkp = NULL;
478 return (0);
479 }
480
481 /*
482 * Get a dev_t corresponding to de so we can try to match rules based
483 * on it. If this routine returns NULL, there is no dev_t associated
484 * with the dirent (symlinks and directories don't have dev_ts), and
485 * the caller should assume that any critera dependent on a dev_t
486 * don't match.
487 */
488 static dev_t
489 devfs_rule_getdev(struct devfs_dirent *de)
490 {
491 dev_t *devp, dev;
492
493 devp = devfs_itod(de->de_inode);
494 if (devp != NULL)
495 dev = *devp;
496 else
497 dev = NULL;
498 /* If we think this dirent should have a dev_t, alert the user. */
499 if (dev == NULL && de->de_dirent->d_type != DT_LNK &&
500 de->de_dirent->d_type != DT_DIR)
501 printf("Warning: no dev_t for %s\n", de->de_dirent->d_name);
502 return (dev);
503 }
504
505 /*
506 * Do what we need to do to a rule that we just loaded from the
507 * userland. In particular, we need to check the magic, and adjust
508 * the ruleset appropriate if desired.
509 */
510 static int
511 devfs_rule_input(struct devfs_rule *dr, struct devfs_mount *dm)
512 {
513
514 if (dr->dr_magic != DEVFS_MAGIC)
515 return (ERPCMISMATCH);
516 dr->dr_id = devfs_rid_input(dr->dr_id, dm);
517 return (0);
518 }
519
520 /*
521 * Import dr into the appropriate place in the kernel (i.e., make a
522 * krule). The value of dr is copied, so the pointer may be destroyed
523 * after this call completes.
524 */
525 static int
526 devfs_rule_insert(struct devfs_rule *dr)
527 {
528 struct devfs_ruleset *ds, *dsi;
529 struct devfs_krule *k1, *k2;
530 struct devfs_krule *dk;
531 devfs_rsnum rsnum;
532 devfs_rnum dkrn;
533 int error;
534
535 /*
536 * This stuff seems out of place here, but we want to do it as
537 * soon as possible so that if it fails, we don't have to roll
538 * back any changes we already made (e.g., ruleset creation).
539 */
540 if (dr->dr_iacts & DRA_INCSET) {
541 dsi = devfs_ruleset_bynum(dr->dr_incset);
542 if (dsi == NULL)
543 return (ESRCH);
544 } else
545 dsi = NULL;
546
547 rsnum = rid2rsn(dr->dr_id);
548 ds = devfs_ruleset_bynum(rsnum);
549 if (ds == NULL)
550 ds = devfs_ruleset_create(rsnum);
551 if (ds->ds_flags & DS_IMMUTABLE)
552 return (EIO);
553 dkrn = rid2rn(dr->dr_id);
554 if (dkrn == 0) {
555 error = devfs_rule_autonumber(ds, &dkrn);
556 if (error != 0)
557 return (error);
558 }
559
560 dk = malloc(sizeof(*dk), M_DEVFS, M_WAITOK);
561 dk->dk_ruleset = ds;
562 if (dsi != NULL)
563 ++dsi->ds_refcount;
564 /* XXX: Inspect dr? */
565 memcpy(&dk->dk_rule, dr, sizeof(*dr));
566 dk->dk_rule.dr_id = mkrid(rid2rsn(dk->dk_rule.dr_id), dkrn);
567
568 k1 = SLIST_FIRST(&ds->ds_rules);
569 if (k1 == NULL || rid2rn(k1->dk_rule.dr_id) > dkrn)
570 SLIST_INSERT_HEAD(&ds->ds_rules, dk, dk_list);
571 else {
572 SLIST_FOREACH(k1, &ds->ds_rules, dk_list) {
573 k2 = SLIST_NEXT(k1, dk_list);
574 if (k2 == NULL || rid2rn(k2->dk_rule.dr_id) > dkrn) {
575 SLIST_INSERT_AFTER(k1, dk, dk_list);
576 break;
577 }
578 }
579 }
580
581 return (0);
582 }
583
584 /*
585 * Determine whether dk matches de. Returns 1 if dk should be run on
586 * de; 0, otherwise.
587 */
588 static int
589 devfs_rule_match(struct devfs_krule *dk, struct devfs_dirent *de)
590 {
591 struct devfs_rule *dr = &dk->dk_rule;
592 dev_t dev;
593
594 dev = devfs_rule_getdev(de);
595 /*
596 * At this point, if dev is NULL, we should assume that any
597 * criteria that depend on it don't match. We should *not*
598 * just ignore them (i.e., act like they weren't specified),
599 * since that makes a rule that only has criteria dependent on
600 * the dev_t match all symlinks and directories.
601 *
602 * Note also that the following tests are somewhat reversed:
603 * They're actually testing to see whether the condition does
604 * *not* match, since the default is to assume the rule should
605 * be run (such as if there are no conditions).
606 */
607 if (dr->dr_icond & DRC_DSWFLAGS)
608 if (dev == NULL ||
609 (dev->si_devsw->d_flags & dr->dr_dswflags) == 0)
610 goto nomatch;
611 if (dr->dr_icond & DRC_PATHPTRN)
612 if (!devfs_rule_matchpath(dk, de))
613 goto nomatch;
614 if (dr->dr_icond & DRC_MAJOR)
615 if (dev == NULL || major(dev) != dr->dr_major)
616 goto nomatch;
617
618 return (1);
619
620 nomatch:
621 return (0);
622 }
623
624 /*
625 * Determine whether dk matches de on account of dr_pathptrn.
626 */
627 static int
628 devfs_rule_matchpath(struct devfs_krule *dk, struct devfs_dirent *de)
629 {
630 struct devfs_rule *dr = &dk->dk_rule;
631 char *pname;
632 dev_t dev;
633
634 dev = devfs_rule_getdev(de);
635 if (dev != NULL)
636 pname = dev->si_name;
637 /* XXX: Support symlinks (check d_type == DT_LNK here). */
638 else
639 return (0);
640 KASSERT(pname != NULL, ("devfs_rule_matchpath: NULL pname"));
641
642 return (fnmatch(dr->dr_pathptrn, pname, 0) == 0);
643 }
644
645 /*
646 * Run dk on de.
647 */
648 static void
649 devfs_rule_run(struct devfs_krule *dk, struct devfs_dirent *de)
650 {
651 struct devfs_rule *dr = &dk->dk_rule;
652 struct devfs_ruleset *ds;
653
654 if (dr->dr_iacts & DRA_BACTS) {
655 if (dr->dr_bacts & DRB_HIDE)
656 de->de_flags |= DE_WHITEOUT;
657 if (dr->dr_bacts & DRB_UNHIDE)
658 de->de_flags &= ~DE_WHITEOUT;
659 }
660 if (dr->dr_iacts & DRA_UID)
661 de->de_uid = dr->dr_uid;
662 if (dr->dr_iacts & DRA_GID)
663 de->de_gid = dr->dr_gid;
664 if (dr->dr_iacts & DRA_MODE)
665 de->de_mode = dr->dr_mode;
666 if (dr->dr_iacts & DRA_INCSET) {
667 ds = devfs_ruleset_bynum(dk->dk_rule.dr_incset);
668 KASSERT(ds != NULL, ("DRA_INCSET but bad dr_incset"));
669 if (ds->ds_running)
670 printf("Warning: avoiding loop through ruleset %d\n",
671 ds->ds_number);
672 else
673 devfs_ruleset_applyde(ds, de);
674 }
675 }
676
677 /*
678 * Apply all the rules in ds to de.
679 */
680 static void
681 devfs_ruleset_applyde(struct devfs_ruleset *ds, struct devfs_dirent *de)
682 {
683 struct devfs_krule *dk;
684
685 KASSERT(!ds->ds_running,("ruleset %d already running", ds->ds_number));
686 ds->ds_running = 1;
687 SLIST_FOREACH(dk, &ds->ds_rules, dk_list) {
688 devfs_rule_applyde(dk, de);
689 }
690 ds->ds_running = 0;
691 }
692
693 /*
694 * Apply all the rules in ds to all the entires in dm.
695 */
696 static void
697 devfs_ruleset_applydm(struct devfs_ruleset *ds, struct devfs_mount *dm)
698 {
699 struct devfs_krule *dk;
700
701 KASSERT(!ds->ds_running,("ruleset %d already running", ds->ds_number));
702 ds->ds_running = 1;
703 /*
704 * XXX: Does it matter whether we do
705 *
706 * foreach(dk in ds)
707 * foreach(de in dm)
708 * apply(dk to de)
709 *
710 * as opposed to
711 *
712 * foreach(de in dm)
713 * foreach(dk in ds)
714 * apply(dk to de)
715 *
716 * The end result is obviously the same, but does the order
717 * matter?
718 */
719 SLIST_FOREACH(dk, &ds->ds_rules, dk_list) {
720 devfs_rule_applydm(dk, dm);
721 }
722 ds->ds_running = 0;
723 }
724
725 /*
726 * Find a ruleset by number.
727 */
728 static struct devfs_ruleset *
729 devfs_ruleset_bynum(devfs_rsnum rsnum)
730 {
731 struct devfs_ruleset *ds;
732
733 SLIST_FOREACH(ds, &devfs_rulesets, ds_list) {
734 if (ds->ds_number == rsnum)
735 return (ds);
736 }
737 return (NULL);
738 }
739
740 /*
741 * Create a new ruleset.
742 */
743 static struct devfs_ruleset *
744 devfs_ruleset_create(devfs_rsnum rsnum)
745 {
746 struct devfs_ruleset *s1, *s2;
747 struct devfs_ruleset *ds;
748
749 KASSERT(devfs_ruleset_bynum(rsnum) == NULL,
750 ("creating already existent ruleset %d", rsnum));
751
752 ds = malloc(sizeof(*ds), M_DEVFS, M_WAITOK | M_ZERO);
753 ds->ds_number = rsnum;
754 ds->ds_refcount = ds->ds_flags = 0;
755 SLIST_INIT(&ds->ds_rules);
756
757 s1 = SLIST_FIRST(&devfs_rulesets);
758 if (s1 == NULL || s1->ds_number > rsnum)
759 SLIST_INSERT_HEAD(&devfs_rulesets, ds, ds_list);
760 else {
761 SLIST_FOREACH(s1, &devfs_rulesets, ds_list) {
762 s2 = SLIST_NEXT(s1, ds_list);
763 if (s2 == NULL || s2->ds_number > rsnum) {
764 SLIST_INSERT_AFTER(s1, ds, ds_list);
765 break;
766 }
767 }
768 }
769
770 return (ds);
771 }
772
773 /*
774 * Remove a ruleset form the system. The ruleset specified must be
775 * empty and not in use.
776 */
777 static void
778 devfs_ruleset_destroy(struct devfs_ruleset **dsp)
779 {
780 struct devfs_ruleset *ds = *dsp;
781
782 KASSERT(SLIST_EMPTY(&ds->ds_rules), ("destroying non-empty ruleset"));
783 KASSERT(ds->ds_refcount == 0, ("destroying busy ruleset"));
784 KASSERT((ds->ds_flags & DS_IMMUTABLE) == 0,
785 ("destroying immutable ruleset"));
786
787 SLIST_REMOVE(&devfs_rulesets, ds, devfs_ruleset, ds_list);
788 free(ds, M_DEVFS);
789 *dsp = NULL;
790 }
791
792 /*
793 * Remove a ruleset from the system if it's empty and not used
794 * anywhere. This should be called after every time a rule is deleted
795 * from this ruleset or the reference count is decremented.
796 */
797 static void
798 devfs_ruleset_reap(struct devfs_ruleset **dsp)
799 {
800 struct devfs_ruleset *ds = *dsp;
801
802 if (SLIST_EMPTY(&ds->ds_rules) && ds->ds_refcount == 0) {
803 devfs_ruleset_destroy(&ds);
804 *dsp = ds;
805 }
806 }
807
808 /*
809 * Make rsnum the active ruleset for dm.
810 */
811 static int
812 devfs_ruleset_use(devfs_rsnum rsnum, struct devfs_mount *dm)
813 {
814 struct devfs_ruleset *cds, *ds;
815
816 ds = devfs_ruleset_bynum(rsnum);
817 if (ds == NULL)
818 ds = devfs_ruleset_create(rsnum);
819 cds = devfs_ruleset_bynum(dm->dm_ruleset);
820 KASSERT(cds != NULL, ("mount-point has NULL ruleset"));
821
822 /* These should probably be made atomic somehow. */
823 --cds->ds_refcount;
824 ++ds->ds_refcount;
825 dm->dm_ruleset = rsnum;
826
827 devfs_ruleset_reap(&cds);
828 return (0);
829 }
830
831 #endif /* !NODEVFS */
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