1 /*
2 * NetLabel Domain Hash Table
3 *
4 * This file manages the domain hash table that NetLabel uses to determine
5 * which network labeling protocol to use for a given domain. The NetLabel
6 * system manages static and dynamic label mappings for network protocols such
7 * as CIPSO and RIPSO.
8 *
9 * Author: Paul Moore <paul@paul-moore.com>
10 *
11 */
12
13 /*
14 * (c) Copyright Hewlett-Packard Development Company, L.P., 2006, 2008
15 *
16 * This program is free software; you can redistribute it and/or modify
17 * it under the terms of the GNU General Public License as published by
18 * the Free Software Foundation; either version 2 of the License, or
19 * (at your option) any later version.
20 *
21 * This program is distributed in the hope that it will be useful,
22 * but WITHOUT ANY WARRANTY; without even the implied warranty of
23 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
24 * the GNU General Public License for more details.
25 *
26 * You should have received a copy of the GNU General Public License
27 * along with this program; if not, write to the Free Software
28 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
29 *
30 */
31
32 #include <linux/types.h>
33 #include <linux/rculist.h>
34 #include <linux/skbuff.h>
35 #include <linux/spinlock.h>
36 #include <linux/string.h>
37 #include <linux/audit.h>
38 #include <linux/slab.h>
39 #include <net/netlabel.h>
40 #include <net/cipso_ipv4.h>
41 #include <asm/bug.h>
42
43 #include "netlabel_mgmt.h"
44 #include "netlabel_addrlist.h"
45 #include "netlabel_domainhash.h"
46 #include "netlabel_user.h"
47
48 struct netlbl_domhsh_tbl {
49 struct list_head *tbl;
50 u32 size;
51 };
52
53 /* Domain hash table */
54 /* updates should be so rare that having one spinlock for the entire hash table
55 * should be okay */
56 static DEFINE_SPINLOCK(netlbl_domhsh_lock);
57 #define netlbl_domhsh_rcu_deref(p) \
58 rcu_dereference_check(p, lockdep_is_held(&netlbl_domhsh_lock))
59 static struct netlbl_domhsh_tbl *netlbl_domhsh = NULL;
60 static struct netlbl_dom_map *netlbl_domhsh_def = NULL;
61
62 /*
63 * Domain Hash Table Helper Functions
64 */
65
66 /**
67 * netlbl_domhsh_free_entry - Frees a domain hash table entry
68 * @entry: the entry's RCU field
69 *
70 * Description:
71 * This function is designed to be used as a callback to the call_rcu()
72 * function so that the memory allocated to a hash table entry can be released
73 * safely.
74 *
75 */
netlbl_domhsh_free_entry(struct rcu_head * entry)76 static void netlbl_domhsh_free_entry(struct rcu_head *entry)
77 {
78 struct netlbl_dom_map *ptr;
79 struct netlbl_af4list *iter4;
80 struct netlbl_af4list *tmp4;
81 #if IS_ENABLED(CONFIG_IPV6)
82 struct netlbl_af6list *iter6;
83 struct netlbl_af6list *tmp6;
84 #endif /* IPv6 */
85
86 ptr = container_of(entry, struct netlbl_dom_map, rcu);
87 if (ptr->type == NETLBL_NLTYPE_ADDRSELECT) {
88 netlbl_af4list_foreach_safe(iter4, tmp4,
89 &ptr->type_def.addrsel->list4) {
90 netlbl_af4list_remove_entry(iter4);
91 kfree(netlbl_domhsh_addr4_entry(iter4));
92 }
93 #if IS_ENABLED(CONFIG_IPV6)
94 netlbl_af6list_foreach_safe(iter6, tmp6,
95 &ptr->type_def.addrsel->list6) {
96 netlbl_af6list_remove_entry(iter6);
97 kfree(netlbl_domhsh_addr6_entry(iter6));
98 }
99 #endif /* IPv6 */
100 }
101 kfree(ptr->domain);
102 kfree(ptr);
103 }
104
105 /**
106 * netlbl_domhsh_hash - Hashing function for the domain hash table
107 * @domain: the domain name to hash
108 *
109 * Description:
110 * This is the hashing function for the domain hash table, it returns the
111 * correct bucket number for the domain. The caller is responsible for
112 * ensuring that the hash table is protected with either a RCU read lock or the
113 * hash table lock.
114 *
115 */
netlbl_domhsh_hash(const char * key)116 static u32 netlbl_domhsh_hash(const char *key)
117 {
118 u32 iter;
119 u32 val;
120 u32 len;
121
122 /* This is taken (with slight modification) from
123 * security/selinux/ss/symtab.c:symhash() */
124
125 for (iter = 0, val = 0, len = strlen(key); iter < len; iter++)
126 val = (val << 4 | (val >> (8 * sizeof(u32) - 4))) ^ key[iter];
127 return val & (netlbl_domhsh_rcu_deref(netlbl_domhsh)->size - 1);
128 }
129
130 /**
131 * netlbl_domhsh_search - Search for a domain entry
132 * @domain: the domain
133 *
134 * Description:
135 * Searches the domain hash table and returns a pointer to the hash table
136 * entry if found, otherwise NULL is returned. The caller is responsible for
137 * ensuring that the hash table is protected with either a RCU read lock or the
138 * hash table lock.
139 *
140 */
netlbl_domhsh_search(const char * domain)141 static struct netlbl_dom_map *netlbl_domhsh_search(const char *domain)
142 {
143 u32 bkt;
144 struct list_head *bkt_list;
145 struct netlbl_dom_map *iter;
146
147 if (domain != NULL) {
148 bkt = netlbl_domhsh_hash(domain);
149 bkt_list = &netlbl_domhsh_rcu_deref(netlbl_domhsh)->tbl[bkt];
150 list_for_each_entry_rcu(iter, bkt_list, list)
151 if (iter->valid && strcmp(iter->domain, domain) == 0)
152 return iter;
153 }
154
155 return NULL;
156 }
157
158 /**
159 * netlbl_domhsh_search_def - Search for a domain entry
160 * @domain: the domain
161 * @def: return default if no match is found
162 *
163 * Description:
164 * Searches the domain hash table and returns a pointer to the hash table
165 * entry if an exact match is found, if an exact match is not present in the
166 * hash table then the default entry is returned if valid otherwise NULL is
167 * returned. The caller is responsible ensuring that the hash table is
168 * protected with either a RCU read lock or the hash table lock.
169 *
170 */
netlbl_domhsh_search_def(const char * domain)171 static struct netlbl_dom_map *netlbl_domhsh_search_def(const char *domain)
172 {
173 struct netlbl_dom_map *entry;
174
175 entry = netlbl_domhsh_search(domain);
176 if (entry == NULL) {
177 entry = netlbl_domhsh_rcu_deref(netlbl_domhsh_def);
178 if (entry != NULL && !entry->valid)
179 entry = NULL;
180 }
181
182 return entry;
183 }
184
185 /**
186 * netlbl_domhsh_audit_add - Generate an audit entry for an add event
187 * @entry: the entry being added
188 * @addr4: the IPv4 address information
189 * @addr6: the IPv6 address information
190 * @result: the result code
191 * @audit_info: NetLabel audit information
192 *
193 * Description:
194 * Generate an audit record for adding a new NetLabel/LSM mapping entry with
195 * the given information. Caller is responsible for holding the necessary
196 * locks.
197 *
198 */
netlbl_domhsh_audit_add(struct netlbl_dom_map * entry,struct netlbl_af4list * addr4,struct netlbl_af6list * addr6,int result,struct netlbl_audit * audit_info)199 static void netlbl_domhsh_audit_add(struct netlbl_dom_map *entry,
200 struct netlbl_af4list *addr4,
201 struct netlbl_af6list *addr6,
202 int result,
203 struct netlbl_audit *audit_info)
204 {
205 struct audit_buffer *audit_buf;
206 struct cipso_v4_doi *cipsov4 = NULL;
207 u32 type;
208
209 audit_buf = netlbl_audit_start_common(AUDIT_MAC_MAP_ADD, audit_info);
210 if (audit_buf != NULL) {
211 audit_log_format(audit_buf, " nlbl_domain=%s",
212 entry->domain ? entry->domain : "(default)");
213 if (addr4 != NULL) {
214 struct netlbl_domaddr4_map *map4;
215 map4 = netlbl_domhsh_addr4_entry(addr4);
216 type = map4->type;
217 cipsov4 = map4->type_def.cipsov4;
218 netlbl_af4list_audit_addr(audit_buf, 0, NULL,
219 addr4->addr, addr4->mask);
220 #if IS_ENABLED(CONFIG_IPV6)
221 } else if (addr6 != NULL) {
222 struct netlbl_domaddr6_map *map6;
223 map6 = netlbl_domhsh_addr6_entry(addr6);
224 type = map6->type;
225 netlbl_af6list_audit_addr(audit_buf, 0, NULL,
226 &addr6->addr, &addr6->mask);
227 #endif /* IPv6 */
228 } else {
229 type = entry->type;
230 cipsov4 = entry->type_def.cipsov4;
231 }
232 switch (type) {
233 case NETLBL_NLTYPE_UNLABELED:
234 audit_log_format(audit_buf, " nlbl_protocol=unlbl");
235 break;
236 case NETLBL_NLTYPE_CIPSOV4:
237 BUG_ON(cipsov4 == NULL);
238 audit_log_format(audit_buf,
239 " nlbl_protocol=cipsov4 cipso_doi=%u",
240 cipsov4->doi);
241 break;
242 }
243 audit_log_format(audit_buf, " res=%u", result == 0 ? 1 : 0);
244 audit_log_end(audit_buf);
245 }
246 }
247
248 /**
249 * netlbl_domhsh_validate - Validate a new domain mapping entry
250 * @entry: the entry to validate
251 *
252 * This function validates the new domain mapping entry to ensure that it is
253 * a valid entry. Returns zero on success, negative values on failure.
254 *
255 */
netlbl_domhsh_validate(const struct netlbl_dom_map * entry)256 static int netlbl_domhsh_validate(const struct netlbl_dom_map *entry)
257 {
258 struct netlbl_af4list *iter4;
259 struct netlbl_domaddr4_map *map4;
260 #if IS_ENABLED(CONFIG_IPV6)
261 struct netlbl_af6list *iter6;
262 struct netlbl_domaddr6_map *map6;
263 #endif /* IPv6 */
264
265 if (entry == NULL)
266 return -EINVAL;
267
268 switch (entry->type) {
269 case NETLBL_NLTYPE_UNLABELED:
270 if (entry->type_def.cipsov4 != NULL ||
271 entry->type_def.addrsel != NULL)
272 return -EINVAL;
273 break;
274 case NETLBL_NLTYPE_CIPSOV4:
275 if (entry->type_def.cipsov4 == NULL)
276 return -EINVAL;
277 break;
278 case NETLBL_NLTYPE_ADDRSELECT:
279 netlbl_af4list_foreach(iter4, &entry->type_def.addrsel->list4) {
280 map4 = netlbl_domhsh_addr4_entry(iter4);
281 switch (map4->type) {
282 case NETLBL_NLTYPE_UNLABELED:
283 if (map4->type_def.cipsov4 != NULL)
284 return -EINVAL;
285 break;
286 case NETLBL_NLTYPE_CIPSOV4:
287 if (map4->type_def.cipsov4 == NULL)
288 return -EINVAL;
289 break;
290 default:
291 return -EINVAL;
292 }
293 }
294 #if IS_ENABLED(CONFIG_IPV6)
295 netlbl_af6list_foreach(iter6, &entry->type_def.addrsel->list6) {
296 map6 = netlbl_domhsh_addr6_entry(iter6);
297 switch (map6->type) {
298 case NETLBL_NLTYPE_UNLABELED:
299 break;
300 default:
301 return -EINVAL;
302 }
303 }
304 #endif /* IPv6 */
305 break;
306 default:
307 return -EINVAL;
308 }
309
310 return 0;
311 }
312
313 /*
314 * Domain Hash Table Functions
315 */
316
317 /**
318 * netlbl_domhsh_init - Init for the domain hash
319 * @size: the number of bits to use for the hash buckets
320 *
321 * Description:
322 * Initializes the domain hash table, should be called only by
323 * netlbl_user_init() during initialization. Returns zero on success, non-zero
324 * values on error.
325 *
326 */
netlbl_domhsh_init(u32 size)327 int __init netlbl_domhsh_init(u32 size)
328 {
329 u32 iter;
330 struct netlbl_domhsh_tbl *hsh_tbl;
331
332 if (size == 0)
333 return -EINVAL;
334
335 hsh_tbl = kmalloc(sizeof(*hsh_tbl), GFP_KERNEL);
336 if (hsh_tbl == NULL)
337 return -ENOMEM;
338 hsh_tbl->size = 1 << size;
339 hsh_tbl->tbl = kcalloc(hsh_tbl->size,
340 sizeof(struct list_head),
341 GFP_KERNEL);
342 if (hsh_tbl->tbl == NULL) {
343 kfree(hsh_tbl);
344 return -ENOMEM;
345 }
346 for (iter = 0; iter < hsh_tbl->size; iter++)
347 INIT_LIST_HEAD(&hsh_tbl->tbl[iter]);
348
349 spin_lock(&netlbl_domhsh_lock);
350 rcu_assign_pointer(netlbl_domhsh, hsh_tbl);
351 spin_unlock(&netlbl_domhsh_lock);
352
353 return 0;
354 }
355
356 /**
357 * netlbl_domhsh_add - Adds a entry to the domain hash table
358 * @entry: the entry to add
359 * @audit_info: NetLabel audit information
360 *
361 * Description:
362 * Adds a new entry to the domain hash table and handles any updates to the
363 * lower level protocol handler (i.e. CIPSO). Returns zero on success,
364 * negative on failure.
365 *
366 */
netlbl_domhsh_add(struct netlbl_dom_map * entry,struct netlbl_audit * audit_info)367 int netlbl_domhsh_add(struct netlbl_dom_map *entry,
368 struct netlbl_audit *audit_info)
369 {
370 int ret_val = 0;
371 struct netlbl_dom_map *entry_old;
372 struct netlbl_af4list *iter4;
373 struct netlbl_af4list *tmp4;
374 #if IS_ENABLED(CONFIG_IPV6)
375 struct netlbl_af6list *iter6;
376 struct netlbl_af6list *tmp6;
377 #endif /* IPv6 */
378
379 ret_val = netlbl_domhsh_validate(entry);
380 if (ret_val != 0)
381 return ret_val;
382
383 /* XXX - we can remove this RCU read lock as the spinlock protects the
384 * entire function, but before we do we need to fixup the
385 * netlbl_af[4,6]list RCU functions to do "the right thing" with
386 * respect to rcu_dereference() when only a spinlock is held. */
387 rcu_read_lock();
388 spin_lock(&netlbl_domhsh_lock);
389 if (entry->domain != NULL)
390 entry_old = netlbl_domhsh_search(entry->domain);
391 else
392 entry_old = netlbl_domhsh_search_def(entry->domain);
393 if (entry_old == NULL) {
394 entry->valid = 1;
395
396 if (entry->domain != NULL) {
397 u32 bkt = netlbl_domhsh_hash(entry->domain);
398 list_add_tail_rcu(&entry->list,
399 &rcu_dereference(netlbl_domhsh)->tbl[bkt]);
400 } else {
401 INIT_LIST_HEAD(&entry->list);
402 rcu_assign_pointer(netlbl_domhsh_def, entry);
403 }
404
405 if (entry->type == NETLBL_NLTYPE_ADDRSELECT) {
406 netlbl_af4list_foreach_rcu(iter4,
407 &entry->type_def.addrsel->list4)
408 netlbl_domhsh_audit_add(entry, iter4, NULL,
409 ret_val, audit_info);
410 #if IS_ENABLED(CONFIG_IPV6)
411 netlbl_af6list_foreach_rcu(iter6,
412 &entry->type_def.addrsel->list6)
413 netlbl_domhsh_audit_add(entry, NULL, iter6,
414 ret_val, audit_info);
415 #endif /* IPv6 */
416 } else
417 netlbl_domhsh_audit_add(entry, NULL, NULL,
418 ret_val, audit_info);
419 } else if (entry_old->type == NETLBL_NLTYPE_ADDRSELECT &&
420 entry->type == NETLBL_NLTYPE_ADDRSELECT) {
421 struct list_head *old_list4;
422 struct list_head *old_list6;
423
424 old_list4 = &entry_old->type_def.addrsel->list4;
425 old_list6 = &entry_old->type_def.addrsel->list6;
426
427 /* we only allow the addition of address selectors if all of
428 * the selectors do not exist in the existing domain map */
429 netlbl_af4list_foreach_rcu(iter4,
430 &entry->type_def.addrsel->list4)
431 if (netlbl_af4list_search_exact(iter4->addr,
432 iter4->mask,
433 old_list4)) {
434 ret_val = -EEXIST;
435 goto add_return;
436 }
437 #if IS_ENABLED(CONFIG_IPV6)
438 netlbl_af6list_foreach_rcu(iter6,
439 &entry->type_def.addrsel->list6)
440 if (netlbl_af6list_search_exact(&iter6->addr,
441 &iter6->mask,
442 old_list6)) {
443 ret_val = -EEXIST;
444 goto add_return;
445 }
446 #endif /* IPv6 */
447
448 netlbl_af4list_foreach_safe(iter4, tmp4,
449 &entry->type_def.addrsel->list4) {
450 netlbl_af4list_remove_entry(iter4);
451 iter4->valid = 1;
452 ret_val = netlbl_af4list_add(iter4, old_list4);
453 netlbl_domhsh_audit_add(entry_old, iter4, NULL,
454 ret_val, audit_info);
455 if (ret_val != 0)
456 goto add_return;
457 }
458 #if IS_ENABLED(CONFIG_IPV6)
459 netlbl_af6list_foreach_safe(iter6, tmp6,
460 &entry->type_def.addrsel->list6) {
461 netlbl_af6list_remove_entry(iter6);
462 iter6->valid = 1;
463 ret_val = netlbl_af6list_add(iter6, old_list6);
464 netlbl_domhsh_audit_add(entry_old, NULL, iter6,
465 ret_val, audit_info);
466 if (ret_val != 0)
467 goto add_return;
468 }
469 #endif /* IPv6 */
470 } else
471 ret_val = -EINVAL;
472
473 add_return:
474 spin_unlock(&netlbl_domhsh_lock);
475 rcu_read_unlock();
476 return ret_val;
477 }
478
479 /**
480 * netlbl_domhsh_add_default - Adds the default entry to the domain hash table
481 * @entry: the entry to add
482 * @audit_info: NetLabel audit information
483 *
484 * Description:
485 * Adds a new default entry to the domain hash table and handles any updates
486 * to the lower level protocol handler (i.e. CIPSO). Returns zero on success,
487 * negative on failure.
488 *
489 */
netlbl_domhsh_add_default(struct netlbl_dom_map * entry,struct netlbl_audit * audit_info)490 int netlbl_domhsh_add_default(struct netlbl_dom_map *entry,
491 struct netlbl_audit *audit_info)
492 {
493 return netlbl_domhsh_add(entry, audit_info);
494 }
495
496 /**
497 * netlbl_domhsh_remove_entry - Removes a given entry from the domain table
498 * @entry: the entry to remove
499 * @audit_info: NetLabel audit information
500 *
501 * Description:
502 * Removes an entry from the domain hash table and handles any updates to the
503 * lower level protocol handler (i.e. CIPSO). Caller is responsible for
504 * ensuring that the RCU read lock is held. Returns zero on success, negative
505 * on failure.
506 *
507 */
netlbl_domhsh_remove_entry(struct netlbl_dom_map * entry,struct netlbl_audit * audit_info)508 int netlbl_domhsh_remove_entry(struct netlbl_dom_map *entry,
509 struct netlbl_audit *audit_info)
510 {
511 int ret_val = 0;
512 struct audit_buffer *audit_buf;
513
514 if (entry == NULL)
515 return -ENOENT;
516
517 spin_lock(&netlbl_domhsh_lock);
518 if (entry->valid) {
519 entry->valid = 0;
520 if (entry != rcu_dereference(netlbl_domhsh_def))
521 list_del_rcu(&entry->list);
522 else
523 RCU_INIT_POINTER(netlbl_domhsh_def, NULL);
524 } else
525 ret_val = -ENOENT;
526 spin_unlock(&netlbl_domhsh_lock);
527
528 audit_buf = netlbl_audit_start_common(AUDIT_MAC_MAP_DEL, audit_info);
529 if (audit_buf != NULL) {
530 audit_log_format(audit_buf,
531 " nlbl_domain=%s res=%u",
532 entry->domain ? entry->domain : "(default)",
533 ret_val == 0 ? 1 : 0);
534 audit_log_end(audit_buf);
535 }
536
537 if (ret_val == 0) {
538 struct netlbl_af4list *iter4;
539 struct netlbl_domaddr4_map *map4;
540
541 switch (entry->type) {
542 case NETLBL_NLTYPE_ADDRSELECT:
543 netlbl_af4list_foreach_rcu(iter4,
544 &entry->type_def.addrsel->list4) {
545 map4 = netlbl_domhsh_addr4_entry(iter4);
546 cipso_v4_doi_putdef(map4->type_def.cipsov4);
547 }
548 /* no need to check the IPv6 list since we currently
549 * support only unlabeled protocols for IPv6 */
550 break;
551 case NETLBL_NLTYPE_CIPSOV4:
552 cipso_v4_doi_putdef(entry->type_def.cipsov4);
553 break;
554 }
555 call_rcu(&entry->rcu, netlbl_domhsh_free_entry);
556 }
557
558 return ret_val;
559 }
560
561 /**
562 * netlbl_domhsh_remove_af4 - Removes an address selector entry
563 * @domain: the domain
564 * @addr: IPv4 address
565 * @mask: IPv4 address mask
566 * @audit_info: NetLabel audit information
567 *
568 * Description:
569 * Removes an individual address selector from a domain mapping and potentially
570 * the entire mapping if it is empty. Returns zero on success, negative values
571 * on failure.
572 *
573 */
netlbl_domhsh_remove_af4(const char * domain,const struct in_addr * addr,const struct in_addr * mask,struct netlbl_audit * audit_info)574 int netlbl_domhsh_remove_af4(const char *domain,
575 const struct in_addr *addr,
576 const struct in_addr *mask,
577 struct netlbl_audit *audit_info)
578 {
579 struct netlbl_dom_map *entry_map;
580 struct netlbl_af4list *entry_addr;
581 struct netlbl_af4list *iter4;
582 #if IS_ENABLED(CONFIG_IPV6)
583 struct netlbl_af6list *iter6;
584 #endif /* IPv6 */
585 struct netlbl_domaddr4_map *entry;
586
587 rcu_read_lock();
588
589 if (domain)
590 entry_map = netlbl_domhsh_search(domain);
591 else
592 entry_map = netlbl_domhsh_search_def(domain);
593 if (entry_map == NULL || entry_map->type != NETLBL_NLTYPE_ADDRSELECT)
594 goto remove_af4_failure;
595
596 spin_lock(&netlbl_domhsh_lock);
597 entry_addr = netlbl_af4list_remove(addr->s_addr, mask->s_addr,
598 &entry_map->type_def.addrsel->list4);
599 spin_unlock(&netlbl_domhsh_lock);
600
601 if (entry_addr == NULL)
602 goto remove_af4_failure;
603 netlbl_af4list_foreach_rcu(iter4, &entry_map->type_def.addrsel->list4)
604 goto remove_af4_single_addr;
605 #if IS_ENABLED(CONFIG_IPV6)
606 netlbl_af6list_foreach_rcu(iter6, &entry_map->type_def.addrsel->list6)
607 goto remove_af4_single_addr;
608 #endif /* IPv6 */
609 /* the domain mapping is empty so remove it from the mapping table */
610 netlbl_domhsh_remove_entry(entry_map, audit_info);
611
612 remove_af4_single_addr:
613 rcu_read_unlock();
614 /* yick, we can't use call_rcu here because we don't have a rcu head
615 * pointer but hopefully this should be a rare case so the pause
616 * shouldn't be a problem */
617 synchronize_rcu();
618 entry = netlbl_domhsh_addr4_entry(entry_addr);
619 cipso_v4_doi_putdef(entry->type_def.cipsov4);
620 kfree(entry);
621 return 0;
622
623 remove_af4_failure:
624 rcu_read_unlock();
625 return -ENOENT;
626 }
627
628 /**
629 * netlbl_domhsh_remove - Removes an entry from the domain hash table
630 * @domain: the domain to remove
631 * @audit_info: NetLabel audit information
632 *
633 * Description:
634 * Removes an entry from the domain hash table and handles any updates to the
635 * lower level protocol handler (i.e. CIPSO). Returns zero on success,
636 * negative on failure.
637 *
638 */
netlbl_domhsh_remove(const char * domain,struct netlbl_audit * audit_info)639 int netlbl_domhsh_remove(const char *domain, struct netlbl_audit *audit_info)
640 {
641 int ret_val;
642 struct netlbl_dom_map *entry;
643
644 rcu_read_lock();
645 if (domain)
646 entry = netlbl_domhsh_search(domain);
647 else
648 entry = netlbl_domhsh_search_def(domain);
649 ret_val = netlbl_domhsh_remove_entry(entry, audit_info);
650 rcu_read_unlock();
651
652 return ret_val;
653 }
654
655 /**
656 * netlbl_domhsh_remove_default - Removes the default entry from the table
657 * @audit_info: NetLabel audit information
658 *
659 * Description:
660 * Removes/resets the default entry for the domain hash table and handles any
661 * updates to the lower level protocol handler (i.e. CIPSO). Returns zero on
662 * success, non-zero on failure.
663 *
664 */
netlbl_domhsh_remove_default(struct netlbl_audit * audit_info)665 int netlbl_domhsh_remove_default(struct netlbl_audit *audit_info)
666 {
667 return netlbl_domhsh_remove(NULL, audit_info);
668 }
669
670 /**
671 * netlbl_domhsh_getentry - Get an entry from the domain hash table
672 * @domain: the domain name to search for
673 *
674 * Description:
675 * Look through the domain hash table searching for an entry to match @domain,
676 * return a pointer to a copy of the entry or NULL. The caller is responsible
677 * for ensuring that rcu_read_[un]lock() is called.
678 *
679 */
netlbl_domhsh_getentry(const char * domain)680 struct netlbl_dom_map *netlbl_domhsh_getentry(const char *domain)
681 {
682 return netlbl_domhsh_search_def(domain);
683 }
684
685 /**
686 * netlbl_domhsh_getentry_af4 - Get an entry from the domain hash table
687 * @domain: the domain name to search for
688 * @addr: the IP address to search for
689 *
690 * Description:
691 * Look through the domain hash table searching for an entry to match @domain
692 * and @addr, return a pointer to a copy of the entry or NULL. The caller is
693 * responsible for ensuring that rcu_read_[un]lock() is called.
694 *
695 */
netlbl_domhsh_getentry_af4(const char * domain,__be32 addr)696 struct netlbl_domaddr4_map *netlbl_domhsh_getentry_af4(const char *domain,
697 __be32 addr)
698 {
699 struct netlbl_dom_map *dom_iter;
700 struct netlbl_af4list *addr_iter;
701
702 dom_iter = netlbl_domhsh_search_def(domain);
703 if (dom_iter == NULL)
704 return NULL;
705 if (dom_iter->type != NETLBL_NLTYPE_ADDRSELECT)
706 return NULL;
707
708 addr_iter = netlbl_af4list_search(addr,
709 &dom_iter->type_def.addrsel->list4);
710 if (addr_iter == NULL)
711 return NULL;
712
713 return netlbl_domhsh_addr4_entry(addr_iter);
714 }
715
716 #if IS_ENABLED(CONFIG_IPV6)
717 /**
718 * netlbl_domhsh_getentry_af6 - Get an entry from the domain hash table
719 * @domain: the domain name to search for
720 * @addr: the IP address to search for
721 *
722 * Description:
723 * Look through the domain hash table searching for an entry to match @domain
724 * and @addr, return a pointer to a copy of the entry or NULL. The caller is
725 * responsible for ensuring that rcu_read_[un]lock() is called.
726 *
727 */
netlbl_domhsh_getentry_af6(const char * domain,const struct in6_addr * addr)728 struct netlbl_domaddr6_map *netlbl_domhsh_getentry_af6(const char *domain,
729 const struct in6_addr *addr)
730 {
731 struct netlbl_dom_map *dom_iter;
732 struct netlbl_af6list *addr_iter;
733
734 dom_iter = netlbl_domhsh_search_def(domain);
735 if (dom_iter == NULL)
736 return NULL;
737 if (dom_iter->type != NETLBL_NLTYPE_ADDRSELECT)
738 return NULL;
739
740 addr_iter = netlbl_af6list_search(addr,
741 &dom_iter->type_def.addrsel->list6);
742 if (addr_iter == NULL)
743 return NULL;
744
745 return netlbl_domhsh_addr6_entry(addr_iter);
746 }
747 #endif /* IPv6 */
748
749 /**
750 * netlbl_domhsh_walk - Iterate through the domain mapping hash table
751 * @skip_bkt: the number of buckets to skip at the start
752 * @skip_chain: the number of entries to skip in the first iterated bucket
753 * @callback: callback for each entry
754 * @cb_arg: argument for the callback function
755 *
756 * Description:
757 * Interate over the domain mapping hash table, skipping the first @skip_bkt
758 * buckets and @skip_chain entries. For each entry in the table call
759 * @callback, if @callback returns a negative value stop 'walking' through the
760 * table and return. Updates the values in @skip_bkt and @skip_chain on
761 * return. Returns zero on success, negative values on failure.
762 *
763 */
netlbl_domhsh_walk(u32 * skip_bkt,u32 * skip_chain,int (* callback)(struct netlbl_dom_map * entry,void * arg),void * cb_arg)764 int netlbl_domhsh_walk(u32 *skip_bkt,
765 u32 *skip_chain,
766 int (*callback) (struct netlbl_dom_map *entry, void *arg),
767 void *cb_arg)
768 {
769 int ret_val = -ENOENT;
770 u32 iter_bkt;
771 struct list_head *iter_list;
772 struct netlbl_dom_map *iter_entry;
773 u32 chain_cnt = 0;
774
775 rcu_read_lock();
776 for (iter_bkt = *skip_bkt;
777 iter_bkt < rcu_dereference(netlbl_domhsh)->size;
778 iter_bkt++, chain_cnt = 0) {
779 iter_list = &rcu_dereference(netlbl_domhsh)->tbl[iter_bkt];
780 list_for_each_entry_rcu(iter_entry, iter_list, list)
781 if (iter_entry->valid) {
782 if (chain_cnt++ < *skip_chain)
783 continue;
784 ret_val = callback(iter_entry, cb_arg);
785 if (ret_val < 0) {
786 chain_cnt--;
787 goto walk_return;
788 }
789 }
790 }
791
792 walk_return:
793 rcu_read_unlock();
794 *skip_bkt = iter_bkt;
795 *skip_chain = chain_cnt;
796 return ret_val;
797 }
798