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.moore@hp.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 <net/netlabel.h>
39 #include <net/cipso_ipv4.h>
40 #include <asm/bug.h>
41
42 #include "netlabel_mgmt.h"
43 #include "netlabel_addrlist.h"
44 #include "netlabel_domainhash.h"
45 #include "netlabel_user.h"
46
47 struct netlbl_domhsh_tbl {
48 struct list_head *tbl;
49 u32 size;
50 };
51
52 /* Domain hash table */
53 /* XXX - updates should be so rare that having one spinlock for the entire
54 * hash table should be okay */
55 static DEFINE_SPINLOCK(netlbl_domhsh_lock);
56 static struct netlbl_domhsh_tbl *netlbl_domhsh = NULL;
57 static struct netlbl_dom_map *netlbl_domhsh_def = NULL;
58
59 /*
60 * Domain Hash Table Helper Functions
61 */
62
63 /**
64 * netlbl_domhsh_free_entry - Frees a domain hash table entry
65 * @entry: the entry's RCU field
66 *
67 * Description:
68 * This function is designed to be used as a callback to the call_rcu()
69 * function so that the memory allocated to a hash table entry can be released
70 * safely.
71 *
72 */
netlbl_domhsh_free_entry(struct rcu_head * entry)73 static void netlbl_domhsh_free_entry(struct rcu_head *entry)
74 {
75 struct netlbl_dom_map *ptr;
76 struct netlbl_af4list *iter4;
77 struct netlbl_af4list *tmp4;
78 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
79 struct netlbl_af6list *iter6;
80 struct netlbl_af6list *tmp6;
81 #endif /* IPv6 */
82
83 ptr = container_of(entry, struct netlbl_dom_map, rcu);
84 if (ptr->type == NETLBL_NLTYPE_ADDRSELECT) {
85 netlbl_af4list_foreach_safe(iter4, tmp4,
86 &ptr->type_def.addrsel->list4) {
87 netlbl_af4list_remove_entry(iter4);
88 kfree(netlbl_domhsh_addr4_entry(iter4));
89 }
90 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
91 netlbl_af6list_foreach_safe(iter6, tmp6,
92 &ptr->type_def.addrsel->list6) {
93 netlbl_af6list_remove_entry(iter6);
94 kfree(netlbl_domhsh_addr6_entry(iter6));
95 }
96 #endif /* IPv6 */
97 }
98 kfree(ptr->domain);
99 kfree(ptr);
100 }
101
102 /**
103 * netlbl_domhsh_hash - Hashing function for the domain hash table
104 * @domain: the domain name to hash
105 *
106 * Description:
107 * This is the hashing function for the domain hash table, it returns the
108 * correct bucket number for the domain. The caller is responsibile for
109 * calling the rcu_read_[un]lock() functions.
110 *
111 */
netlbl_domhsh_hash(const char * key)112 static u32 netlbl_domhsh_hash(const char *key)
113 {
114 u32 iter;
115 u32 val;
116 u32 len;
117
118 /* This is taken (with slight modification) from
119 * security/selinux/ss/symtab.c:symhash() */
120
121 for (iter = 0, val = 0, len = strlen(key); iter < len; iter++)
122 val = (val << 4 | (val >> (8 * sizeof(u32) - 4))) ^ key[iter];
123 return val & (rcu_dereference(netlbl_domhsh)->size - 1);
124 }
125
126 /**
127 * netlbl_domhsh_search - Search for a domain entry
128 * @domain: the domain
129 *
130 * Description:
131 * Searches the domain hash table and returns a pointer to the hash table
132 * entry if found, otherwise NULL is returned. The caller is responsibile for
133 * the rcu hash table locks (i.e. the caller much call rcu_read_[un]lock()).
134 *
135 */
netlbl_domhsh_search(const char * domain)136 static struct netlbl_dom_map *netlbl_domhsh_search(const char *domain)
137 {
138 u32 bkt;
139 struct list_head *bkt_list;
140 struct netlbl_dom_map *iter;
141
142 if (domain != NULL) {
143 bkt = netlbl_domhsh_hash(domain);
144 bkt_list = &rcu_dereference(netlbl_domhsh)->tbl[bkt];
145 list_for_each_entry_rcu(iter, bkt_list, list)
146 if (iter->valid && strcmp(iter->domain, domain) == 0)
147 return iter;
148 }
149
150 return NULL;
151 }
152
153 /**
154 * netlbl_domhsh_search_def - Search for a domain entry
155 * @domain: the domain
156 * @def: return default if no match is found
157 *
158 * Description:
159 * Searches the domain hash table and returns a pointer to the hash table
160 * entry if an exact match is found, if an exact match is not present in the
161 * hash table then the default entry is returned if valid otherwise NULL is
162 * returned. The caller is responsibile for the rcu hash table locks
163 * (i.e. the caller much call rcu_read_[un]lock()).
164 *
165 */
netlbl_domhsh_search_def(const char * domain)166 static struct netlbl_dom_map *netlbl_domhsh_search_def(const char *domain)
167 {
168 struct netlbl_dom_map *entry;
169
170 entry = netlbl_domhsh_search(domain);
171 if (entry == NULL) {
172 entry = rcu_dereference(netlbl_domhsh_def);
173 if (entry != NULL && !entry->valid)
174 entry = NULL;
175 }
176
177 return entry;
178 }
179
180 /**
181 * netlbl_domhsh_audit_add - Generate an audit entry for an add event
182 * @entry: the entry being added
183 * @addr4: the IPv4 address information
184 * @addr6: the IPv6 address information
185 * @result: the result code
186 * @audit_info: NetLabel audit information
187 *
188 * Description:
189 * Generate an audit record for adding a new NetLabel/LSM mapping entry with
190 * the given information. Caller is responsibile for holding the necessary
191 * locks.
192 *
193 */
netlbl_domhsh_audit_add(struct netlbl_dom_map * entry,struct netlbl_af4list * addr4,struct netlbl_af6list * addr6,int result,struct netlbl_audit * audit_info)194 static void netlbl_domhsh_audit_add(struct netlbl_dom_map *entry,
195 struct netlbl_af4list *addr4,
196 struct netlbl_af6list *addr6,
197 int result,
198 struct netlbl_audit *audit_info)
199 {
200 struct audit_buffer *audit_buf;
201 struct cipso_v4_doi *cipsov4 = NULL;
202 u32 type;
203
204 audit_buf = netlbl_audit_start_common(AUDIT_MAC_MAP_ADD, audit_info);
205 if (audit_buf != NULL) {
206 audit_log_format(audit_buf, " nlbl_domain=%s",
207 entry->domain ? entry->domain : "(default)");
208 if (addr4 != NULL) {
209 struct netlbl_domaddr4_map *map4;
210 map4 = netlbl_domhsh_addr4_entry(addr4);
211 type = map4->type;
212 cipsov4 = map4->type_def.cipsov4;
213 netlbl_af4list_audit_addr(audit_buf, 0, NULL,
214 addr4->addr, addr4->mask);
215 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
216 } else if (addr6 != NULL) {
217 struct netlbl_domaddr6_map *map6;
218 map6 = netlbl_domhsh_addr6_entry(addr6);
219 type = map6->type;
220 netlbl_af6list_audit_addr(audit_buf, 0, NULL,
221 &addr6->addr, &addr6->mask);
222 #endif /* IPv6 */
223 } else {
224 type = entry->type;
225 cipsov4 = entry->type_def.cipsov4;
226 }
227 switch (type) {
228 case NETLBL_NLTYPE_UNLABELED:
229 audit_log_format(audit_buf, " nlbl_protocol=unlbl");
230 break;
231 case NETLBL_NLTYPE_CIPSOV4:
232 BUG_ON(cipsov4 == NULL);
233 audit_log_format(audit_buf,
234 " nlbl_protocol=cipsov4 cipso_doi=%u",
235 cipsov4->doi);
236 break;
237 }
238 audit_log_format(audit_buf, " res=%u", result == 0 ? 1 : 0);
239 audit_log_end(audit_buf);
240 }
241 }
242
243 /*
244 * Domain Hash Table Functions
245 */
246
247 /**
248 * netlbl_domhsh_init - Init for the domain hash
249 * @size: the number of bits to use for the hash buckets
250 *
251 * Description:
252 * Initializes the domain hash table, should be called only by
253 * netlbl_user_init() during initialization. Returns zero on success, non-zero
254 * values on error.
255 *
256 */
netlbl_domhsh_init(u32 size)257 int __init netlbl_domhsh_init(u32 size)
258 {
259 u32 iter;
260 struct netlbl_domhsh_tbl *hsh_tbl;
261
262 if (size == 0)
263 return -EINVAL;
264
265 hsh_tbl = kmalloc(sizeof(*hsh_tbl), GFP_KERNEL);
266 if (hsh_tbl == NULL)
267 return -ENOMEM;
268 hsh_tbl->size = 1 << size;
269 hsh_tbl->tbl = kcalloc(hsh_tbl->size,
270 sizeof(struct list_head),
271 GFP_KERNEL);
272 if (hsh_tbl->tbl == NULL) {
273 kfree(hsh_tbl);
274 return -ENOMEM;
275 }
276 for (iter = 0; iter < hsh_tbl->size; iter++)
277 INIT_LIST_HEAD(&hsh_tbl->tbl[iter]);
278
279 spin_lock(&netlbl_domhsh_lock);
280 rcu_assign_pointer(netlbl_domhsh, hsh_tbl);
281 spin_unlock(&netlbl_domhsh_lock);
282
283 return 0;
284 }
285
286 /**
287 * netlbl_domhsh_add - Adds a entry to the domain hash table
288 * @entry: the entry to add
289 * @audit_info: NetLabel audit information
290 *
291 * Description:
292 * Adds a new entry to the domain hash table and handles any updates to the
293 * lower level protocol handler (i.e. CIPSO). Returns zero on success,
294 * negative on failure.
295 *
296 */
netlbl_domhsh_add(struct netlbl_dom_map * entry,struct netlbl_audit * audit_info)297 int netlbl_domhsh_add(struct netlbl_dom_map *entry,
298 struct netlbl_audit *audit_info)
299 {
300 int ret_val = 0;
301 struct netlbl_dom_map *entry_old;
302 struct netlbl_af4list *iter4;
303 struct netlbl_af4list *tmp4;
304 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
305 struct netlbl_af6list *iter6;
306 struct netlbl_af6list *tmp6;
307 #endif /* IPv6 */
308
309 rcu_read_lock();
310
311 spin_lock(&netlbl_domhsh_lock);
312 if (entry->domain != NULL)
313 entry_old = netlbl_domhsh_search(entry->domain);
314 else
315 entry_old = netlbl_domhsh_search_def(entry->domain);
316 if (entry_old == NULL) {
317 entry->valid = 1;
318 INIT_RCU_HEAD(&entry->rcu);
319
320 if (entry->domain != NULL) {
321 u32 bkt = netlbl_domhsh_hash(entry->domain);
322 list_add_tail_rcu(&entry->list,
323 &rcu_dereference(netlbl_domhsh)->tbl[bkt]);
324 } else {
325 INIT_LIST_HEAD(&entry->list);
326 rcu_assign_pointer(netlbl_domhsh_def, entry);
327 }
328
329 if (entry->type == NETLBL_NLTYPE_ADDRSELECT) {
330 netlbl_af4list_foreach_rcu(iter4,
331 &entry->type_def.addrsel->list4)
332 netlbl_domhsh_audit_add(entry, iter4, NULL,
333 ret_val, audit_info);
334 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
335 netlbl_af6list_foreach_rcu(iter6,
336 &entry->type_def.addrsel->list6)
337 netlbl_domhsh_audit_add(entry, NULL, iter6,
338 ret_val, audit_info);
339 #endif /* IPv6 */
340 } else
341 netlbl_domhsh_audit_add(entry, NULL, NULL,
342 ret_val, audit_info);
343 } else if (entry_old->type == NETLBL_NLTYPE_ADDRSELECT &&
344 entry->type == NETLBL_NLTYPE_ADDRSELECT) {
345 struct list_head *old_list4;
346 struct list_head *old_list6;
347
348 old_list4 = &entry_old->type_def.addrsel->list4;
349 old_list6 = &entry_old->type_def.addrsel->list6;
350
351 /* we only allow the addition of address selectors if all of
352 * the selectors do not exist in the existing domain map */
353 netlbl_af4list_foreach_rcu(iter4,
354 &entry->type_def.addrsel->list4)
355 if (netlbl_af4list_search_exact(iter4->addr,
356 iter4->mask,
357 old_list4)) {
358 ret_val = -EEXIST;
359 goto add_return;
360 }
361 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
362 netlbl_af6list_foreach_rcu(iter6,
363 &entry->type_def.addrsel->list6)
364 if (netlbl_af6list_search_exact(&iter6->addr,
365 &iter6->mask,
366 old_list6)) {
367 ret_val = -EEXIST;
368 goto add_return;
369 }
370 #endif /* IPv6 */
371
372 netlbl_af4list_foreach_safe(iter4, tmp4,
373 &entry->type_def.addrsel->list4) {
374 netlbl_af4list_remove_entry(iter4);
375 iter4->valid = 1;
376 ret_val = netlbl_af4list_add(iter4, old_list4);
377 netlbl_domhsh_audit_add(entry_old, iter4, NULL,
378 ret_val, audit_info);
379 if (ret_val != 0)
380 goto add_return;
381 }
382 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
383 netlbl_af6list_foreach_safe(iter6, tmp6,
384 &entry->type_def.addrsel->list6) {
385 netlbl_af6list_remove_entry(iter6);
386 iter6->valid = 1;
387 ret_val = netlbl_af6list_add(iter6, old_list6);
388 netlbl_domhsh_audit_add(entry_old, NULL, iter6,
389 ret_val, audit_info);
390 if (ret_val != 0)
391 goto add_return;
392 }
393 #endif /* IPv6 */
394 } else
395 ret_val = -EINVAL;
396
397 add_return:
398 spin_unlock(&netlbl_domhsh_lock);
399 rcu_read_unlock();
400 return ret_val;
401 }
402
403 /**
404 * netlbl_domhsh_add_default - Adds the default entry to the domain hash table
405 * @entry: the entry to add
406 * @audit_info: NetLabel audit information
407 *
408 * Description:
409 * Adds a new default entry to the domain hash table and handles any updates
410 * to the lower level protocol handler (i.e. CIPSO). Returns zero on success,
411 * negative on failure.
412 *
413 */
netlbl_domhsh_add_default(struct netlbl_dom_map * entry,struct netlbl_audit * audit_info)414 int netlbl_domhsh_add_default(struct netlbl_dom_map *entry,
415 struct netlbl_audit *audit_info)
416 {
417 return netlbl_domhsh_add(entry, audit_info);
418 }
419
420 /**
421 * netlbl_domhsh_remove_entry - Removes a given entry from the domain table
422 * @entry: the entry to remove
423 * @audit_info: NetLabel audit information
424 *
425 * Description:
426 * Removes an entry from the domain hash table and handles any updates to the
427 * lower level protocol handler (i.e. CIPSO). Caller is responsible for
428 * ensuring that the RCU read lock is held. Returns zero on success, negative
429 * on failure.
430 *
431 */
netlbl_domhsh_remove_entry(struct netlbl_dom_map * entry,struct netlbl_audit * audit_info)432 int netlbl_domhsh_remove_entry(struct netlbl_dom_map *entry,
433 struct netlbl_audit *audit_info)
434 {
435 int ret_val = 0;
436 struct audit_buffer *audit_buf;
437
438 if (entry == NULL)
439 return -ENOENT;
440
441 spin_lock(&netlbl_domhsh_lock);
442 if (entry->valid) {
443 entry->valid = 0;
444 if (entry != rcu_dereference(netlbl_domhsh_def))
445 list_del_rcu(&entry->list);
446 else
447 rcu_assign_pointer(netlbl_domhsh_def, NULL);
448 } else
449 ret_val = -ENOENT;
450 spin_unlock(&netlbl_domhsh_lock);
451
452 audit_buf = netlbl_audit_start_common(AUDIT_MAC_MAP_DEL, audit_info);
453 if (audit_buf != NULL) {
454 audit_log_format(audit_buf,
455 " nlbl_domain=%s res=%u",
456 entry->domain ? entry->domain : "(default)",
457 ret_val == 0 ? 1 : 0);
458 audit_log_end(audit_buf);
459 }
460
461 if (ret_val == 0) {
462 struct netlbl_af4list *iter4;
463 struct netlbl_domaddr4_map *map4;
464
465 switch (entry->type) {
466 case NETLBL_NLTYPE_ADDRSELECT:
467 netlbl_af4list_foreach_rcu(iter4,
468 &entry->type_def.addrsel->list4) {
469 map4 = netlbl_domhsh_addr4_entry(iter4);
470 cipso_v4_doi_putdef(map4->type_def.cipsov4);
471 }
472 /* no need to check the IPv6 list since we currently
473 * support only unlabeled protocols for IPv6 */
474 break;
475 case NETLBL_NLTYPE_CIPSOV4:
476 cipso_v4_doi_putdef(entry->type_def.cipsov4);
477 break;
478 }
479 call_rcu(&entry->rcu, netlbl_domhsh_free_entry);
480 }
481
482 return ret_val;
483 }
484
485 /**
486 * netlbl_domhsh_remove_af4 - Removes an address selector entry
487 * @domain: the domain
488 * @addr: IPv4 address
489 * @mask: IPv4 address mask
490 * @audit_info: NetLabel audit information
491 *
492 * Description:
493 * Removes an individual address selector from a domain mapping and potentially
494 * the entire mapping if it is empty. Returns zero on success, negative values
495 * on failure.
496 *
497 */
netlbl_domhsh_remove_af4(const char * domain,const struct in_addr * addr,const struct in_addr * mask,struct netlbl_audit * audit_info)498 int netlbl_domhsh_remove_af4(const char *domain,
499 const struct in_addr *addr,
500 const struct in_addr *mask,
501 struct netlbl_audit *audit_info)
502 {
503 struct netlbl_dom_map *entry_map;
504 struct netlbl_af4list *entry_addr;
505 struct netlbl_af4list *iter4;
506 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
507 struct netlbl_af6list *iter6;
508 #endif /* IPv6 */
509 struct netlbl_domaddr4_map *entry;
510
511 rcu_read_lock();
512
513 if (domain)
514 entry_map = netlbl_domhsh_search(domain);
515 else
516 entry_map = netlbl_domhsh_search_def(domain);
517 if (entry_map == NULL || entry_map->type != NETLBL_NLTYPE_ADDRSELECT)
518 goto remove_af4_failure;
519
520 spin_lock(&netlbl_domhsh_lock);
521 entry_addr = netlbl_af4list_remove(addr->s_addr, mask->s_addr,
522 &entry_map->type_def.addrsel->list4);
523 spin_unlock(&netlbl_domhsh_lock);
524
525 if (entry_addr == NULL)
526 goto remove_af4_failure;
527 netlbl_af4list_foreach_rcu(iter4, &entry_map->type_def.addrsel->list4)
528 goto remove_af4_single_addr;
529 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
530 netlbl_af6list_foreach_rcu(iter6, &entry_map->type_def.addrsel->list6)
531 goto remove_af4_single_addr;
532 #endif /* IPv6 */
533 /* the domain mapping is empty so remove it from the mapping table */
534 netlbl_domhsh_remove_entry(entry_map, audit_info);
535
536 remove_af4_single_addr:
537 rcu_read_unlock();
538 /* yick, we can't use call_rcu here because we don't have a rcu head
539 * pointer but hopefully this should be a rare case so the pause
540 * shouldn't be a problem */
541 synchronize_rcu();
542 entry = netlbl_domhsh_addr4_entry(entry_addr);
543 cipso_v4_doi_putdef(entry->type_def.cipsov4);
544 kfree(entry);
545 return 0;
546
547 remove_af4_failure:
548 rcu_read_unlock();
549 return -ENOENT;
550 }
551
552 /**
553 * netlbl_domhsh_remove - Removes an entry from the domain hash table
554 * @domain: the domain to remove
555 * @audit_info: NetLabel audit information
556 *
557 * Description:
558 * Removes an entry from the domain hash table and handles any updates to the
559 * lower level protocol handler (i.e. CIPSO). Returns zero on success,
560 * negative on failure.
561 *
562 */
netlbl_domhsh_remove(const char * domain,struct netlbl_audit * audit_info)563 int netlbl_domhsh_remove(const char *domain, struct netlbl_audit *audit_info)
564 {
565 int ret_val;
566 struct netlbl_dom_map *entry;
567
568 rcu_read_lock();
569 if (domain)
570 entry = netlbl_domhsh_search(domain);
571 else
572 entry = netlbl_domhsh_search_def(domain);
573 ret_val = netlbl_domhsh_remove_entry(entry, audit_info);
574 rcu_read_unlock();
575
576 return ret_val;
577 }
578
579 /**
580 * netlbl_domhsh_remove_default - Removes the default entry from the table
581 * @audit_info: NetLabel audit information
582 *
583 * Description:
584 * Removes/resets the default entry for the domain hash table and handles any
585 * updates to the lower level protocol handler (i.e. CIPSO). Returns zero on
586 * success, non-zero on failure.
587 *
588 */
netlbl_domhsh_remove_default(struct netlbl_audit * audit_info)589 int netlbl_domhsh_remove_default(struct netlbl_audit *audit_info)
590 {
591 return netlbl_domhsh_remove(NULL, audit_info);
592 }
593
594 /**
595 * netlbl_domhsh_getentry - Get an entry from the domain hash table
596 * @domain: the domain name to search for
597 *
598 * Description:
599 * Look through the domain hash table searching for an entry to match @domain,
600 * return a pointer to a copy of the entry or NULL. The caller is responsibile
601 * for ensuring that rcu_read_[un]lock() is called.
602 *
603 */
netlbl_domhsh_getentry(const char * domain)604 struct netlbl_dom_map *netlbl_domhsh_getentry(const char *domain)
605 {
606 return netlbl_domhsh_search_def(domain);
607 }
608
609 /**
610 * netlbl_domhsh_getentry_af4 - Get an entry from the domain hash table
611 * @domain: the domain name to search for
612 * @addr: the IP address to search for
613 *
614 * Description:
615 * Look through the domain hash table searching for an entry to match @domain
616 * and @addr, return a pointer to a copy of the entry or NULL. The caller is
617 * responsible for ensuring that rcu_read_[un]lock() is called.
618 *
619 */
netlbl_domhsh_getentry_af4(const char * domain,__be32 addr)620 struct netlbl_domaddr4_map *netlbl_domhsh_getentry_af4(const char *domain,
621 __be32 addr)
622 {
623 struct netlbl_dom_map *dom_iter;
624 struct netlbl_af4list *addr_iter;
625
626 dom_iter = netlbl_domhsh_search_def(domain);
627 if (dom_iter == NULL)
628 return NULL;
629 if (dom_iter->type != NETLBL_NLTYPE_ADDRSELECT)
630 return NULL;
631
632 addr_iter = netlbl_af4list_search(addr,
633 &dom_iter->type_def.addrsel->list4);
634 if (addr_iter == NULL)
635 return NULL;
636
637 return netlbl_domhsh_addr4_entry(addr_iter);
638 }
639
640 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
641 /**
642 * netlbl_domhsh_getentry_af6 - Get an entry from the domain hash table
643 * @domain: the domain name to search for
644 * @addr: the IP address to search for
645 *
646 * Description:
647 * Look through the domain hash table searching for an entry to match @domain
648 * and @addr, return a pointer to a copy of the entry or NULL. The caller is
649 * responsible for ensuring that rcu_read_[un]lock() is called.
650 *
651 */
netlbl_domhsh_getentry_af6(const char * domain,const struct in6_addr * addr)652 struct netlbl_domaddr6_map *netlbl_domhsh_getentry_af6(const char *domain,
653 const struct in6_addr *addr)
654 {
655 struct netlbl_dom_map *dom_iter;
656 struct netlbl_af6list *addr_iter;
657
658 dom_iter = netlbl_domhsh_search_def(domain);
659 if (dom_iter == NULL)
660 return NULL;
661 if (dom_iter->type != NETLBL_NLTYPE_ADDRSELECT)
662 return NULL;
663
664 addr_iter = netlbl_af6list_search(addr,
665 &dom_iter->type_def.addrsel->list6);
666 if (addr_iter == NULL)
667 return NULL;
668
669 return netlbl_domhsh_addr6_entry(addr_iter);
670 }
671 #endif /* IPv6 */
672
673 /**
674 * netlbl_domhsh_walk - Iterate through the domain mapping hash table
675 * @skip_bkt: the number of buckets to skip at the start
676 * @skip_chain: the number of entries to skip in the first iterated bucket
677 * @callback: callback for each entry
678 * @cb_arg: argument for the callback function
679 *
680 * Description:
681 * Interate over the domain mapping hash table, skipping the first @skip_bkt
682 * buckets and @skip_chain entries. For each entry in the table call
683 * @callback, if @callback returns a negative value stop 'walking' through the
684 * table and return. Updates the values in @skip_bkt and @skip_chain on
685 * return. Returns zero on succcess, negative values on failure.
686 *
687 */
netlbl_domhsh_walk(u32 * skip_bkt,u32 * skip_chain,int (* callback)(struct netlbl_dom_map * entry,void * arg),void * cb_arg)688 int netlbl_domhsh_walk(u32 *skip_bkt,
689 u32 *skip_chain,
690 int (*callback) (struct netlbl_dom_map *entry, void *arg),
691 void *cb_arg)
692 {
693 int ret_val = -ENOENT;
694 u32 iter_bkt;
695 struct list_head *iter_list;
696 struct netlbl_dom_map *iter_entry;
697 u32 chain_cnt = 0;
698
699 rcu_read_lock();
700 for (iter_bkt = *skip_bkt;
701 iter_bkt < rcu_dereference(netlbl_domhsh)->size;
702 iter_bkt++, chain_cnt = 0) {
703 iter_list = &rcu_dereference(netlbl_domhsh)->tbl[iter_bkt];
704 list_for_each_entry_rcu(iter_entry, iter_list, list)
705 if (iter_entry->valid) {
706 if (chain_cnt++ < *skip_chain)
707 continue;
708 ret_val = callback(iter_entry, cb_arg);
709 if (ret_val < 0) {
710 chain_cnt--;
711 goto walk_return;
712 }
713 }
714 }
715
716 walk_return:
717 rcu_read_unlock();
718 *skip_bkt = iter_bkt;
719 *skip_chain = chain_cnt;
720 return ret_val;
721 }
722