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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
48struct 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 */
56static DEFINE_SPINLOCK(netlbl_domhsh_lock);
57#define netlbl_domhsh_rcu_deref(p) \
58 rcu_dereference_check(p, lockdep_is_held(&netlbl_domhsh_lock))
59static struct netlbl_domhsh_tbl *netlbl_domhsh = NULL;
60static 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 */
76static 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 defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
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 defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
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 */
116static 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 */
141static 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 */
171static 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 */
199static 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 defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
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 * Domain Hash Table Functions
250 */
251
252/**
253 * netlbl_domhsh_init - Init for the domain hash
254 * @size: the number of bits to use for the hash buckets
255 *
256 * Description:
257 * Initializes the domain hash table, should be called only by
258 * netlbl_user_init() during initialization. Returns zero on success, non-zero
259 * values on error.
260 *
261 */
262int __init netlbl_domhsh_init(u32 size)
263{
264 u32 iter;
265 struct netlbl_domhsh_tbl *hsh_tbl;
266
267 if (size == 0)
268 return -EINVAL;
269
270 hsh_tbl = kmalloc(sizeof(*hsh_tbl), GFP_KERNEL);
271 if (hsh_tbl == NULL)
272 return -ENOMEM;
273 hsh_tbl->size = 1 << size;
274 hsh_tbl->tbl = kcalloc(hsh_tbl->size,
275 sizeof(struct list_head),
276 GFP_KERNEL);
277 if (hsh_tbl->tbl == NULL) {
278 kfree(hsh_tbl);
279 return -ENOMEM;
280 }
281 for (iter = 0; iter < hsh_tbl->size; iter++)
282 INIT_LIST_HEAD(&hsh_tbl->tbl[iter]);
283
284 spin_lock(&netlbl_domhsh_lock);
285 rcu_assign_pointer(netlbl_domhsh, hsh_tbl);
286 spin_unlock(&netlbl_domhsh_lock);
287
288 return 0;
289}
290
291/**
292 * netlbl_domhsh_add - Adds a entry to the domain hash table
293 * @entry: the entry to add
294 * @audit_info: NetLabel audit information
295 *
296 * Description:
297 * Adds a new entry to the domain hash table and handles any updates to the
298 * lower level protocol handler (i.e. CIPSO). Returns zero on success,
299 * negative on failure.
300 *
301 */
302int netlbl_domhsh_add(struct netlbl_dom_map *entry,
303 struct netlbl_audit *audit_info)
304{
305 int ret_val = 0;
306 struct netlbl_dom_map *entry_old;
307 struct netlbl_af4list *iter4;
308 struct netlbl_af4list *tmp4;
309#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
310 struct netlbl_af6list *iter6;
311 struct netlbl_af6list *tmp6;
312#endif /* IPv6 */
313
314 /* XXX - we can remove this RCU read lock as the spinlock protects the
315 * entire function, but before we do we need to fixup the
316 * netlbl_af[4,6]list RCU functions to do "the right thing" with
317 * respect to rcu_dereference() when only a spinlock is held. */
318 rcu_read_lock();
319 spin_lock(&netlbl_domhsh_lock);
320 if (entry->domain != NULL)
321 entry_old = netlbl_domhsh_search(entry->domain);
322 else
323 entry_old = netlbl_domhsh_search_def(entry->domain);
324 if (entry_old == NULL) {
325 entry->valid = 1;
326
327 if (entry->domain != NULL) {
328 u32 bkt = netlbl_domhsh_hash(entry->domain);
329 list_add_tail_rcu(&entry->list,
330 &rcu_dereference(netlbl_domhsh)->tbl[bkt]);
331 } else {
332 INIT_LIST_HEAD(&entry->list);
333 rcu_assign_pointer(netlbl_domhsh_def, entry);
334 }
335
336 if (entry->type == NETLBL_NLTYPE_ADDRSELECT) {
337 netlbl_af4list_foreach_rcu(iter4,
338 &entry->type_def.addrsel->list4)
339 netlbl_domhsh_audit_add(entry, iter4, NULL,
340 ret_val, audit_info);
341#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
342 netlbl_af6list_foreach_rcu(iter6,
343 &entry->type_def.addrsel->list6)
344 netlbl_domhsh_audit_add(entry, NULL, iter6,
345 ret_val, audit_info);
346#endif /* IPv6 */
347 } else
348 netlbl_domhsh_audit_add(entry, NULL, NULL,
349 ret_val, audit_info);
350 } else if (entry_old->type == NETLBL_NLTYPE_ADDRSELECT &&
351 entry->type == NETLBL_NLTYPE_ADDRSELECT) {
352 struct list_head *old_list4;
353 struct list_head *old_list6;
354
355 old_list4 = &entry_old->type_def.addrsel->list4;
356 old_list6 = &entry_old->type_def.addrsel->list6;
357
358 /* we only allow the addition of address selectors if all of
359 * the selectors do not exist in the existing domain map */
360 netlbl_af4list_foreach_rcu(iter4,
361 &entry->type_def.addrsel->list4)
362 if (netlbl_af4list_search_exact(iter4->addr,
363 iter4->mask,
364 old_list4)) {
365 ret_val = -EEXIST;
366 goto add_return;
367 }
368#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
369 netlbl_af6list_foreach_rcu(iter6,
370 &entry->type_def.addrsel->list6)
371 if (netlbl_af6list_search_exact(&iter6->addr,
372 &iter6->mask,
373 old_list6)) {
374 ret_val = -EEXIST;
375 goto add_return;
376 }
377#endif /* IPv6 */
378
379 netlbl_af4list_foreach_safe(iter4, tmp4,
380 &entry->type_def.addrsel->list4) {
381 netlbl_af4list_remove_entry(iter4);
382 iter4->valid = 1;
383 ret_val = netlbl_af4list_add(iter4, old_list4);
384 netlbl_domhsh_audit_add(entry_old, iter4, NULL,
385 ret_val, audit_info);
386 if (ret_val != 0)
387 goto add_return;
388 }
389#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
390 netlbl_af6list_foreach_safe(iter6, tmp6,
391 &entry->type_def.addrsel->list6) {
392 netlbl_af6list_remove_entry(iter6);
393 iter6->valid = 1;
394 ret_val = netlbl_af6list_add(iter6, old_list6);
395 netlbl_domhsh_audit_add(entry_old, NULL, iter6,
396 ret_val, audit_info);
397 if (ret_val != 0)
398 goto add_return;
399 }
400#endif /* IPv6 */
401 } else
402 ret_val = -EINVAL;
403
404add_return:
405 spin_unlock(&netlbl_domhsh_lock);
406 rcu_read_unlock();
407 return ret_val;
408}
409
410/**
411 * netlbl_domhsh_add_default - Adds the default entry to the domain hash table
412 * @entry: the entry to add
413 * @audit_info: NetLabel audit information
414 *
415 * Description:
416 * Adds a new default entry to the domain hash table and handles any updates
417 * to the lower level protocol handler (i.e. CIPSO). Returns zero on success,
418 * negative on failure.
419 *
420 */
421int netlbl_domhsh_add_default(struct netlbl_dom_map *entry,
422 struct netlbl_audit *audit_info)
423{
424 return netlbl_domhsh_add(entry, audit_info);
425}
426
427/**
428 * netlbl_domhsh_remove_entry - Removes a given entry from the domain table
429 * @entry: the entry to remove
430 * @audit_info: NetLabel audit information
431 *
432 * Description:
433 * Removes an entry from the domain hash table and handles any updates to the
434 * lower level protocol handler (i.e. CIPSO). Caller is responsible for
435 * ensuring that the RCU read lock is held. Returns zero on success, negative
436 * on failure.
437 *
438 */
439int netlbl_domhsh_remove_entry(struct netlbl_dom_map *entry,
440 struct netlbl_audit *audit_info)
441{
442 int ret_val = 0;
443 struct audit_buffer *audit_buf;
444
445 if (entry == NULL)
446 return -ENOENT;
447
448 spin_lock(&netlbl_domhsh_lock);
449 if (entry->valid) {
450 entry->valid = 0;
451 if (entry != rcu_dereference(netlbl_domhsh_def))
452 list_del_rcu(&entry->list);
453 else
454 rcu_assign_pointer(netlbl_domhsh_def, NULL);
455 } else
456 ret_val = -ENOENT;
457 spin_unlock(&netlbl_domhsh_lock);
458
459 audit_buf = netlbl_audit_start_common(AUDIT_MAC_MAP_DEL, audit_info);
460 if (audit_buf != NULL) {
461 audit_log_format(audit_buf,
462 " nlbl_domain=%s res=%u",
463 entry->domain ? entry->domain : "(default)",
464 ret_val == 0 ? 1 : 0);
465 audit_log_end(audit_buf);
466 }
467
468 if (ret_val == 0) {
469 struct netlbl_af4list *iter4;
470 struct netlbl_domaddr4_map *map4;
471
472 switch (entry->type) {
473 case NETLBL_NLTYPE_ADDRSELECT:
474 netlbl_af4list_foreach_rcu(iter4,
475 &entry->type_def.addrsel->list4) {
476 map4 = netlbl_domhsh_addr4_entry(iter4);
477 cipso_v4_doi_putdef(map4->type_def.cipsov4);
478 }
479 /* no need to check the IPv6 list since we currently
480 * support only unlabeled protocols for IPv6 */
481 break;
482 case NETLBL_NLTYPE_CIPSOV4:
483 cipso_v4_doi_putdef(entry->type_def.cipsov4);
484 break;
485 }
486 call_rcu(&entry->rcu, netlbl_domhsh_free_entry);
487 }
488
489 return ret_val;
490}
491
492/**
493 * netlbl_domhsh_remove_af4 - Removes an address selector entry
494 * @domain: the domain
495 * @addr: IPv4 address
496 * @mask: IPv4 address mask
497 * @audit_info: NetLabel audit information
498 *
499 * Description:
500 * Removes an individual address selector from a domain mapping and potentially
501 * the entire mapping if it is empty. Returns zero on success, negative values
502 * on failure.
503 *
504 */
505int netlbl_domhsh_remove_af4(const char *domain,
506 const struct in_addr *addr,
507 const struct in_addr *mask,
508 struct netlbl_audit *audit_info)
509{
510 struct netlbl_dom_map *entry_map;
511 struct netlbl_af4list *entry_addr;
512 struct netlbl_af4list *iter4;
513#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
514 struct netlbl_af6list *iter6;
515#endif /* IPv6 */
516 struct netlbl_domaddr4_map *entry;
517
518 rcu_read_lock();
519
520 if (domain)
521 entry_map = netlbl_domhsh_search(domain);
522 else
523 entry_map = netlbl_domhsh_search_def(domain);
524 if (entry_map == NULL || entry_map->type != NETLBL_NLTYPE_ADDRSELECT)
525 goto remove_af4_failure;
526
527 spin_lock(&netlbl_domhsh_lock);
528 entry_addr = netlbl_af4list_remove(addr->s_addr, mask->s_addr,
529 &entry_map->type_def.addrsel->list4);
530 spin_unlock(&netlbl_domhsh_lock);
531
532 if (entry_addr == NULL)
533 goto remove_af4_failure;
534 netlbl_af4list_foreach_rcu(iter4, &entry_map->type_def.addrsel->list4)
535 goto remove_af4_single_addr;
536#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
537 netlbl_af6list_foreach_rcu(iter6, &entry_map->type_def.addrsel->list6)
538 goto remove_af4_single_addr;
539#endif /* IPv6 */
540 /* the domain mapping is empty so remove it from the mapping table */
541 netlbl_domhsh_remove_entry(entry_map, audit_info);
542
543remove_af4_single_addr:
544 rcu_read_unlock();
545 /* yick, we can't use call_rcu here because we don't have a rcu head
546 * pointer but hopefully this should be a rare case so the pause
547 * shouldn't be a problem */
548 synchronize_rcu();
549 entry = netlbl_domhsh_addr4_entry(entry_addr);
550 cipso_v4_doi_putdef(entry->type_def.cipsov4);
551 kfree(entry);
552 return 0;
553
554remove_af4_failure:
555 rcu_read_unlock();
556 return -ENOENT;
557}
558
559/**
560 * netlbl_domhsh_remove - Removes an entry from the domain hash table
561 * @domain: the domain to remove
562 * @audit_info: NetLabel audit information
563 *
564 * Description:
565 * Removes an entry from the domain hash table and handles any updates to the
566 * lower level protocol handler (i.e. CIPSO). Returns zero on success,
567 * negative on failure.
568 *
569 */
570int netlbl_domhsh_remove(const char *domain, struct netlbl_audit *audit_info)
571{
572 int ret_val;
573 struct netlbl_dom_map *entry;
574
575 rcu_read_lock();
576 if (domain)
577 entry = netlbl_domhsh_search(domain);
578 else
579 entry = netlbl_domhsh_search_def(domain);
580 ret_val = netlbl_domhsh_remove_entry(entry, audit_info);
581 rcu_read_unlock();
582
583 return ret_val;
584}
585
586/**
587 * netlbl_domhsh_remove_default - Removes the default entry from the table
588 * @audit_info: NetLabel audit information
589 *
590 * Description:
591 * Removes/resets the default entry for the domain hash table and handles any
592 * updates to the lower level protocol handler (i.e. CIPSO). Returns zero on
593 * success, non-zero on failure.
594 *
595 */
596int netlbl_domhsh_remove_default(struct netlbl_audit *audit_info)
597{
598 return netlbl_domhsh_remove(NULL, audit_info);
599}
600
601/**
602 * netlbl_domhsh_getentry - Get an entry from the domain hash table
603 * @domain: the domain name to search for
604 *
605 * Description:
606 * Look through the domain hash table searching for an entry to match @domain,
607 * return a pointer to a copy of the entry or NULL. The caller is responsible
608 * for ensuring that rcu_read_[un]lock() is called.
609 *
610 */
611struct netlbl_dom_map *netlbl_domhsh_getentry(const char *domain)
612{
613 return netlbl_domhsh_search_def(domain);
614}
615
616/**
617 * netlbl_domhsh_getentry_af4 - Get an entry from the domain hash table
618 * @domain: the domain name to search for
619 * @addr: the IP address to search for
620 *
621 * Description:
622 * Look through the domain hash table searching for an entry to match @domain
623 * and @addr, return a pointer to a copy of the entry or NULL. The caller is
624 * responsible for ensuring that rcu_read_[un]lock() is called.
625 *
626 */
627struct netlbl_domaddr4_map *netlbl_domhsh_getentry_af4(const char *domain,
628 __be32 addr)
629{
630 struct netlbl_dom_map *dom_iter;
631 struct netlbl_af4list *addr_iter;
632
633 dom_iter = netlbl_domhsh_search_def(domain);
634 if (dom_iter == NULL)
635 return NULL;
636 if (dom_iter->type != NETLBL_NLTYPE_ADDRSELECT)
637 return NULL;
638
639 addr_iter = netlbl_af4list_search(addr,
640 &dom_iter->type_def.addrsel->list4);
641 if (addr_iter == NULL)
642 return NULL;
643
644 return netlbl_domhsh_addr4_entry(addr_iter);
645}
646
647#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
648/**
649 * netlbl_domhsh_getentry_af6 - Get an entry from the domain hash table
650 * @domain: the domain name to search for
651 * @addr: the IP address to search for
652 *
653 * Description:
654 * Look through the domain hash table searching for an entry to match @domain
655 * and @addr, return a pointer to a copy of the entry or NULL. The caller is
656 * responsible for ensuring that rcu_read_[un]lock() is called.
657 *
658 */
659struct netlbl_domaddr6_map *netlbl_domhsh_getentry_af6(const char *domain,
660 const struct in6_addr *addr)
661{
662 struct netlbl_dom_map *dom_iter;
663 struct netlbl_af6list *addr_iter;
664
665 dom_iter = netlbl_domhsh_search_def(domain);
666 if (dom_iter == NULL)
667 return NULL;
668 if (dom_iter->type != NETLBL_NLTYPE_ADDRSELECT)
669 return NULL;
670
671 addr_iter = netlbl_af6list_search(addr,
672 &dom_iter->type_def.addrsel->list6);
673 if (addr_iter == NULL)
674 return NULL;
675
676 return netlbl_domhsh_addr6_entry(addr_iter);
677}
678#endif /* IPv6 */
679
680/**
681 * netlbl_domhsh_walk - Iterate through the domain mapping hash table
682 * @skip_bkt: the number of buckets to skip at the start
683 * @skip_chain: the number of entries to skip in the first iterated bucket
684 * @callback: callback for each entry
685 * @cb_arg: argument for the callback function
686 *
687 * Description:
688 * Interate over the domain mapping hash table, skipping the first @skip_bkt
689 * buckets and @skip_chain entries. For each entry in the table call
690 * @callback, if @callback returns a negative value stop 'walking' through the
691 * table and return. Updates the values in @skip_bkt and @skip_chain on
692 * return. Returns zero on success, negative values on failure.
693 *
694 */
695int netlbl_domhsh_walk(u32 *skip_bkt,
696 u32 *skip_chain,
697 int (*callback) (struct netlbl_dom_map *entry, void *arg),
698 void *cb_arg)
699{
700 int ret_val = -ENOENT;
701 u32 iter_bkt;
702 struct list_head *iter_list;
703 struct netlbl_dom_map *iter_entry;
704 u32 chain_cnt = 0;
705
706 rcu_read_lock();
707 for (iter_bkt = *skip_bkt;
708 iter_bkt < rcu_dereference(netlbl_domhsh)->size;
709 iter_bkt++, chain_cnt = 0) {
710 iter_list = &rcu_dereference(netlbl_domhsh)->tbl[iter_bkt];
711 list_for_each_entry_rcu(iter_entry, iter_list, list)
712 if (iter_entry->valid) {
713 if (chain_cnt++ < *skip_chain)
714 continue;
715 ret_val = callback(iter_entry, cb_arg);
716 if (ret_val < 0) {
717 chain_cnt--;
718 goto walk_return;
719 }
720 }
721 }
722
723walk_return:
724 rcu_read_unlock();
725 *skip_bkt = iter_bkt;
726 *skip_chain = chain_cnt;
727 return ret_val;
728}
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, see <http://www.gnu.org/licenses/>.
28 *
29 */
30
31#include <linux/types.h>
32#include <linux/rculist.h>
33#include <linux/skbuff.h>
34#include <linux/spinlock.h>
35#include <linux/string.h>
36#include <linux/audit.h>
37#include <linux/slab.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
47struct netlbl_domhsh_tbl {
48 struct list_head *tbl;
49 u32 size;
50};
51
52/* Domain hash table */
53/* updates should be so rare that having one spinlock for the entire hash table
54 * should be okay */
55static DEFINE_SPINLOCK(netlbl_domhsh_lock);
56#define netlbl_domhsh_rcu_deref(p) \
57 rcu_dereference_check(p, lockdep_is_held(&netlbl_domhsh_lock))
58static struct netlbl_domhsh_tbl *netlbl_domhsh;
59static struct netlbl_dom_map *netlbl_domhsh_def;
60
61/*
62 * Domain Hash Table Helper Functions
63 */
64
65/**
66 * netlbl_domhsh_free_entry - Frees a domain hash table entry
67 * @entry: the entry's RCU field
68 *
69 * Description:
70 * This function is designed to be used as a callback to the call_rcu()
71 * function so that the memory allocated to a hash table entry can be released
72 * safely.
73 *
74 */
75static void netlbl_domhsh_free_entry(struct rcu_head *entry)
76{
77 struct netlbl_dom_map *ptr;
78 struct netlbl_af4list *iter4;
79 struct netlbl_af4list *tmp4;
80#if IS_ENABLED(CONFIG_IPV6)
81 struct netlbl_af6list *iter6;
82 struct netlbl_af6list *tmp6;
83#endif /* IPv6 */
84
85 ptr = container_of(entry, struct netlbl_dom_map, rcu);
86 if (ptr->def.type == NETLBL_NLTYPE_ADDRSELECT) {
87 netlbl_af4list_foreach_safe(iter4, tmp4,
88 &ptr->def.addrsel->list4) {
89 netlbl_af4list_remove_entry(iter4);
90 kfree(netlbl_domhsh_addr4_entry(iter4));
91 }
92#if IS_ENABLED(CONFIG_IPV6)
93 netlbl_af6list_foreach_safe(iter6, tmp6,
94 &ptr->def.addrsel->list6) {
95 netlbl_af6list_remove_entry(iter6);
96 kfree(netlbl_domhsh_addr6_entry(iter6));
97 }
98#endif /* IPv6 */
99 }
100 kfree(ptr->domain);
101 kfree(ptr);
102}
103
104/**
105 * netlbl_domhsh_hash - Hashing function for the domain hash table
106 * @domain: the domain name to hash
107 *
108 * Description:
109 * This is the hashing function for the domain hash table, it returns the
110 * correct bucket number for the domain. The caller is responsible for
111 * ensuring that the hash table is protected with either a RCU read lock or the
112 * hash table lock.
113 *
114 */
115static u32 netlbl_domhsh_hash(const char *key)
116{
117 u32 iter;
118 u32 val;
119 u32 len;
120
121 /* This is taken (with slight modification) from
122 * security/selinux/ss/symtab.c:symhash() */
123
124 for (iter = 0, val = 0, len = strlen(key); iter < len; iter++)
125 val = (val << 4 | (val >> (8 * sizeof(u32) - 4))) ^ key[iter];
126 return val & (netlbl_domhsh_rcu_deref(netlbl_domhsh)->size - 1);
127}
128
129/**
130 * netlbl_domhsh_search - Search for a domain entry
131 * @domain: the domain
132 *
133 * Description:
134 * Searches the domain hash table and returns a pointer to the hash table
135 * entry if found, otherwise NULL is returned. The caller is responsible for
136 * ensuring that the hash table is protected with either a RCU read lock or the
137 * hash table lock.
138 *
139 */
140static struct netlbl_dom_map *netlbl_domhsh_search(const char *domain)
141{
142 u32 bkt;
143 struct list_head *bkt_list;
144 struct netlbl_dom_map *iter;
145
146 if (domain != NULL) {
147 bkt = netlbl_domhsh_hash(domain);
148 bkt_list = &netlbl_domhsh_rcu_deref(netlbl_domhsh)->tbl[bkt];
149 list_for_each_entry_rcu(iter, bkt_list, list)
150 if (iter->valid && strcmp(iter->domain, domain) == 0)
151 return iter;
152 }
153
154 return NULL;
155}
156
157/**
158 * netlbl_domhsh_search_def - Search for a domain entry
159 * @domain: the domain
160 * @def: return default if no match is found
161 *
162 * Description:
163 * Searches the domain hash table and returns a pointer to the hash table
164 * entry if an exact match is found, if an exact match is not present in the
165 * hash table then the default entry is returned if valid otherwise NULL is
166 * returned. The caller is responsible ensuring that the hash table is
167 * protected with either a RCU read lock or the hash table lock.
168 *
169 */
170static struct netlbl_dom_map *netlbl_domhsh_search_def(const char *domain)
171{
172 struct netlbl_dom_map *entry;
173
174 entry = netlbl_domhsh_search(domain);
175 if (entry == NULL) {
176 entry = netlbl_domhsh_rcu_deref(netlbl_domhsh_def);
177 if (entry != NULL && !entry->valid)
178 entry = NULL;
179 }
180
181 return entry;
182}
183
184/**
185 * netlbl_domhsh_audit_add - Generate an audit entry for an add event
186 * @entry: the entry being added
187 * @addr4: the IPv4 address information
188 * @addr6: the IPv6 address information
189 * @result: the result code
190 * @audit_info: NetLabel audit information
191 *
192 * Description:
193 * Generate an audit record for adding a new NetLabel/LSM mapping entry with
194 * the given information. Caller is responsible for holding the necessary
195 * locks.
196 *
197 */
198static void netlbl_domhsh_audit_add(struct netlbl_dom_map *entry,
199 struct netlbl_af4list *addr4,
200 struct netlbl_af6list *addr6,
201 int result,
202 struct netlbl_audit *audit_info)
203{
204 struct audit_buffer *audit_buf;
205 struct cipso_v4_doi *cipsov4 = NULL;
206 u32 type;
207
208 audit_buf = netlbl_audit_start_common(AUDIT_MAC_MAP_ADD, audit_info);
209 if (audit_buf != NULL) {
210 audit_log_format(audit_buf, " nlbl_domain=%s",
211 entry->domain ? entry->domain : "(default)");
212 if (addr4 != NULL) {
213 struct netlbl_domaddr4_map *map4;
214 map4 = netlbl_domhsh_addr4_entry(addr4);
215 type = map4->def.type;
216 cipsov4 = map4->def.cipso;
217 netlbl_af4list_audit_addr(audit_buf, 0, NULL,
218 addr4->addr, addr4->mask);
219#if IS_ENABLED(CONFIG_IPV6)
220 } else if (addr6 != NULL) {
221 struct netlbl_domaddr6_map *map6;
222 map6 = netlbl_domhsh_addr6_entry(addr6);
223 type = map6->def.type;
224 netlbl_af6list_audit_addr(audit_buf, 0, NULL,
225 &addr6->addr, &addr6->mask);
226#endif /* IPv6 */
227 } else {
228 type = entry->def.type;
229 cipsov4 = entry->def.cipso;
230 }
231 switch (type) {
232 case NETLBL_NLTYPE_UNLABELED:
233 audit_log_format(audit_buf, " nlbl_protocol=unlbl");
234 break;
235 case NETLBL_NLTYPE_CIPSOV4:
236 BUG_ON(cipsov4 == NULL);
237 audit_log_format(audit_buf,
238 " nlbl_protocol=cipsov4 cipso_doi=%u",
239 cipsov4->doi);
240 break;
241 }
242 audit_log_format(audit_buf, " res=%u", result == 0 ? 1 : 0);
243 audit_log_end(audit_buf);
244 }
245}
246
247/**
248 * netlbl_domhsh_validate - Validate a new domain mapping entry
249 * @entry: the entry to validate
250 *
251 * This function validates the new domain mapping entry to ensure that it is
252 * a valid entry. Returns zero on success, negative values on failure.
253 *
254 */
255static int netlbl_domhsh_validate(const struct netlbl_dom_map *entry)
256{
257 struct netlbl_af4list *iter4;
258 struct netlbl_domaddr4_map *map4;
259#if IS_ENABLED(CONFIG_IPV6)
260 struct netlbl_af6list *iter6;
261 struct netlbl_domaddr6_map *map6;
262#endif /* IPv6 */
263
264 if (entry == NULL)
265 return -EINVAL;
266
267 switch (entry->def.type) {
268 case NETLBL_NLTYPE_UNLABELED:
269 if (entry->def.cipso != NULL || entry->def.addrsel != NULL)
270 return -EINVAL;
271 break;
272 case NETLBL_NLTYPE_CIPSOV4:
273 if (entry->def.cipso == NULL)
274 return -EINVAL;
275 break;
276 case NETLBL_NLTYPE_ADDRSELECT:
277 netlbl_af4list_foreach(iter4, &entry->def.addrsel->list4) {
278 map4 = netlbl_domhsh_addr4_entry(iter4);
279 switch (map4->def.type) {
280 case NETLBL_NLTYPE_UNLABELED:
281 if (map4->def.cipso != NULL)
282 return -EINVAL;
283 break;
284 case NETLBL_NLTYPE_CIPSOV4:
285 if (map4->def.cipso == NULL)
286 return -EINVAL;
287 break;
288 default:
289 return -EINVAL;
290 }
291 }
292#if IS_ENABLED(CONFIG_IPV6)
293 netlbl_af6list_foreach(iter6, &entry->def.addrsel->list6) {
294 map6 = netlbl_domhsh_addr6_entry(iter6);
295 switch (map6->def.type) {
296 case NETLBL_NLTYPE_UNLABELED:
297 break;
298 default:
299 return -EINVAL;
300 }
301 }
302#endif /* IPv6 */
303 break;
304 default:
305 return -EINVAL;
306 }
307
308 return 0;
309}
310
311/*
312 * Domain Hash Table Functions
313 */
314
315/**
316 * netlbl_domhsh_init - Init for the domain hash
317 * @size: the number of bits to use for the hash buckets
318 *
319 * Description:
320 * Initializes the domain hash table, should be called only by
321 * netlbl_user_init() during initialization. Returns zero on success, non-zero
322 * values on error.
323 *
324 */
325int __init netlbl_domhsh_init(u32 size)
326{
327 u32 iter;
328 struct netlbl_domhsh_tbl *hsh_tbl;
329
330 if (size == 0)
331 return -EINVAL;
332
333 hsh_tbl = kmalloc(sizeof(*hsh_tbl), GFP_KERNEL);
334 if (hsh_tbl == NULL)
335 return -ENOMEM;
336 hsh_tbl->size = 1 << size;
337 hsh_tbl->tbl = kcalloc(hsh_tbl->size,
338 sizeof(struct list_head),
339 GFP_KERNEL);
340 if (hsh_tbl->tbl == NULL) {
341 kfree(hsh_tbl);
342 return -ENOMEM;
343 }
344 for (iter = 0; iter < hsh_tbl->size; iter++)
345 INIT_LIST_HEAD(&hsh_tbl->tbl[iter]);
346
347 spin_lock(&netlbl_domhsh_lock);
348 rcu_assign_pointer(netlbl_domhsh, hsh_tbl);
349 spin_unlock(&netlbl_domhsh_lock);
350
351 return 0;
352}
353
354/**
355 * netlbl_domhsh_add - Adds a entry to the domain hash table
356 * @entry: the entry to add
357 * @audit_info: NetLabel audit information
358 *
359 * Description:
360 * Adds a new entry to the domain hash table and handles any updates to the
361 * lower level protocol handler (i.e. CIPSO). Returns zero on success,
362 * negative on failure.
363 *
364 */
365int netlbl_domhsh_add(struct netlbl_dom_map *entry,
366 struct netlbl_audit *audit_info)
367{
368 int ret_val = 0;
369 struct netlbl_dom_map *entry_old;
370 struct netlbl_af4list *iter4;
371 struct netlbl_af4list *tmp4;
372#if IS_ENABLED(CONFIG_IPV6)
373 struct netlbl_af6list *iter6;
374 struct netlbl_af6list *tmp6;
375#endif /* IPv6 */
376
377 ret_val = netlbl_domhsh_validate(entry);
378 if (ret_val != 0)
379 return ret_val;
380
381 /* XXX - we can remove this RCU read lock as the spinlock protects the
382 * entire function, but before we do we need to fixup the
383 * netlbl_af[4,6]list RCU functions to do "the right thing" with
384 * respect to rcu_dereference() when only a spinlock is held. */
385 rcu_read_lock();
386 spin_lock(&netlbl_domhsh_lock);
387 if (entry->domain != NULL)
388 entry_old = netlbl_domhsh_search(entry->domain);
389 else
390 entry_old = netlbl_domhsh_search_def(entry->domain);
391 if (entry_old == NULL) {
392 entry->valid = 1;
393
394 if (entry->domain != NULL) {
395 u32 bkt = netlbl_domhsh_hash(entry->domain);
396 list_add_tail_rcu(&entry->list,
397 &rcu_dereference(netlbl_domhsh)->tbl[bkt]);
398 } else {
399 INIT_LIST_HEAD(&entry->list);
400 rcu_assign_pointer(netlbl_domhsh_def, entry);
401 }
402
403 if (entry->def.type == NETLBL_NLTYPE_ADDRSELECT) {
404 netlbl_af4list_foreach_rcu(iter4,
405 &entry->def.addrsel->list4)
406 netlbl_domhsh_audit_add(entry, iter4, NULL,
407 ret_val, audit_info);
408#if IS_ENABLED(CONFIG_IPV6)
409 netlbl_af6list_foreach_rcu(iter6,
410 &entry->def.addrsel->list6)
411 netlbl_domhsh_audit_add(entry, NULL, iter6,
412 ret_val, audit_info);
413#endif /* IPv6 */
414 } else
415 netlbl_domhsh_audit_add(entry, NULL, NULL,
416 ret_val, audit_info);
417 } else if (entry_old->def.type == NETLBL_NLTYPE_ADDRSELECT &&
418 entry->def.type == NETLBL_NLTYPE_ADDRSELECT) {
419 struct list_head *old_list4;
420 struct list_head *old_list6;
421
422 old_list4 = &entry_old->def.addrsel->list4;
423 old_list6 = &entry_old->def.addrsel->list6;
424
425 /* we only allow the addition of address selectors if all of
426 * the selectors do not exist in the existing domain map */
427 netlbl_af4list_foreach_rcu(iter4, &entry->def.addrsel->list4)
428 if (netlbl_af4list_search_exact(iter4->addr,
429 iter4->mask,
430 old_list4)) {
431 ret_val = -EEXIST;
432 goto add_return;
433 }
434#if IS_ENABLED(CONFIG_IPV6)
435 netlbl_af6list_foreach_rcu(iter6, &entry->def.addrsel->list6)
436 if (netlbl_af6list_search_exact(&iter6->addr,
437 &iter6->mask,
438 old_list6)) {
439 ret_val = -EEXIST;
440 goto add_return;
441 }
442#endif /* IPv6 */
443
444 netlbl_af4list_foreach_safe(iter4, tmp4,
445 &entry->def.addrsel->list4) {
446 netlbl_af4list_remove_entry(iter4);
447 iter4->valid = 1;
448 ret_val = netlbl_af4list_add(iter4, old_list4);
449 netlbl_domhsh_audit_add(entry_old, iter4, NULL,
450 ret_val, audit_info);
451 if (ret_val != 0)
452 goto add_return;
453 }
454#if IS_ENABLED(CONFIG_IPV6)
455 netlbl_af6list_foreach_safe(iter6, tmp6,
456 &entry->def.addrsel->list6) {
457 netlbl_af6list_remove_entry(iter6);
458 iter6->valid = 1;
459 ret_val = netlbl_af6list_add(iter6, old_list6);
460 netlbl_domhsh_audit_add(entry_old, NULL, iter6,
461 ret_val, audit_info);
462 if (ret_val != 0)
463 goto add_return;
464 }
465#endif /* IPv6 */
466 } else
467 ret_val = -EINVAL;
468
469add_return:
470 spin_unlock(&netlbl_domhsh_lock);
471 rcu_read_unlock();
472 return ret_val;
473}
474
475/**
476 * netlbl_domhsh_add_default - Adds the default entry to the domain hash table
477 * @entry: the entry to add
478 * @audit_info: NetLabel audit information
479 *
480 * Description:
481 * Adds a new default entry to the domain hash table and handles any updates
482 * to the lower level protocol handler (i.e. CIPSO). Returns zero on success,
483 * negative on failure.
484 *
485 */
486int netlbl_domhsh_add_default(struct netlbl_dom_map *entry,
487 struct netlbl_audit *audit_info)
488{
489 return netlbl_domhsh_add(entry, audit_info);
490}
491
492/**
493 * netlbl_domhsh_remove_entry - Removes a given entry from the domain table
494 * @entry: the entry to remove
495 * @audit_info: NetLabel audit information
496 *
497 * Description:
498 * Removes an entry from the domain hash table and handles any updates to the
499 * lower level protocol handler (i.e. CIPSO). Caller is responsible for
500 * ensuring that the RCU read lock is held. Returns zero on success, negative
501 * on failure.
502 *
503 */
504int netlbl_domhsh_remove_entry(struct netlbl_dom_map *entry,
505 struct netlbl_audit *audit_info)
506{
507 int ret_val = 0;
508 struct audit_buffer *audit_buf;
509
510 if (entry == NULL)
511 return -ENOENT;
512
513 spin_lock(&netlbl_domhsh_lock);
514 if (entry->valid) {
515 entry->valid = 0;
516 if (entry != rcu_dereference(netlbl_domhsh_def))
517 list_del_rcu(&entry->list);
518 else
519 RCU_INIT_POINTER(netlbl_domhsh_def, NULL);
520 } else
521 ret_val = -ENOENT;
522 spin_unlock(&netlbl_domhsh_lock);
523
524 audit_buf = netlbl_audit_start_common(AUDIT_MAC_MAP_DEL, audit_info);
525 if (audit_buf != NULL) {
526 audit_log_format(audit_buf,
527 " nlbl_domain=%s res=%u",
528 entry->domain ? entry->domain : "(default)",
529 ret_val == 0 ? 1 : 0);
530 audit_log_end(audit_buf);
531 }
532
533 if (ret_val == 0) {
534 struct netlbl_af4list *iter4;
535 struct netlbl_domaddr4_map *map4;
536
537 switch (entry->def.type) {
538 case NETLBL_NLTYPE_ADDRSELECT:
539 netlbl_af4list_foreach_rcu(iter4,
540 &entry->def.addrsel->list4) {
541 map4 = netlbl_domhsh_addr4_entry(iter4);
542 cipso_v4_doi_putdef(map4->def.cipso);
543 }
544 /* no need to check the IPv6 list since we currently
545 * support only unlabeled protocols for IPv6 */
546 break;
547 case NETLBL_NLTYPE_CIPSOV4:
548 cipso_v4_doi_putdef(entry->def.cipso);
549 break;
550 }
551 call_rcu(&entry->rcu, netlbl_domhsh_free_entry);
552 }
553
554 return ret_val;
555}
556
557/**
558 * netlbl_domhsh_remove_af4 - Removes an address selector entry
559 * @domain: the domain
560 * @addr: IPv4 address
561 * @mask: IPv4 address mask
562 * @audit_info: NetLabel audit information
563 *
564 * Description:
565 * Removes an individual address selector from a domain mapping and potentially
566 * the entire mapping if it is empty. Returns zero on success, negative values
567 * on failure.
568 *
569 */
570int netlbl_domhsh_remove_af4(const char *domain,
571 const struct in_addr *addr,
572 const struct in_addr *mask,
573 struct netlbl_audit *audit_info)
574{
575 struct netlbl_dom_map *entry_map;
576 struct netlbl_af4list *entry_addr;
577 struct netlbl_af4list *iter4;
578#if IS_ENABLED(CONFIG_IPV6)
579 struct netlbl_af6list *iter6;
580#endif /* IPv6 */
581 struct netlbl_domaddr4_map *entry;
582
583 rcu_read_lock();
584
585 if (domain)
586 entry_map = netlbl_domhsh_search(domain);
587 else
588 entry_map = netlbl_domhsh_search_def(domain);
589 if (entry_map == NULL ||
590 entry_map->def.type != NETLBL_NLTYPE_ADDRSELECT)
591 goto remove_af4_failure;
592
593 spin_lock(&netlbl_domhsh_lock);
594 entry_addr = netlbl_af4list_remove(addr->s_addr, mask->s_addr,
595 &entry_map->def.addrsel->list4);
596 spin_unlock(&netlbl_domhsh_lock);
597
598 if (entry_addr == NULL)
599 goto remove_af4_failure;
600 netlbl_af4list_foreach_rcu(iter4, &entry_map->def.addrsel->list4)
601 goto remove_af4_single_addr;
602#if IS_ENABLED(CONFIG_IPV6)
603 netlbl_af6list_foreach_rcu(iter6, &entry_map->def.addrsel->list6)
604 goto remove_af4_single_addr;
605#endif /* IPv6 */
606 /* the domain mapping is empty so remove it from the mapping table */
607 netlbl_domhsh_remove_entry(entry_map, audit_info);
608
609remove_af4_single_addr:
610 rcu_read_unlock();
611 /* yick, we can't use call_rcu here because we don't have a rcu head
612 * pointer but hopefully this should be a rare case so the pause
613 * shouldn't be a problem */
614 synchronize_rcu();
615 entry = netlbl_domhsh_addr4_entry(entry_addr);
616 cipso_v4_doi_putdef(entry->def.cipso);
617 kfree(entry);
618 return 0;
619
620remove_af4_failure:
621 rcu_read_unlock();
622 return -ENOENT;
623}
624
625/**
626 * netlbl_domhsh_remove - Removes an entry from the domain hash table
627 * @domain: the domain to remove
628 * @audit_info: NetLabel audit information
629 *
630 * Description:
631 * Removes an entry from the domain hash table and handles any updates to the
632 * lower level protocol handler (i.e. CIPSO). Returns zero on success,
633 * negative on failure.
634 *
635 */
636int netlbl_domhsh_remove(const char *domain, struct netlbl_audit *audit_info)
637{
638 int ret_val;
639 struct netlbl_dom_map *entry;
640
641 rcu_read_lock();
642 if (domain)
643 entry = netlbl_domhsh_search(domain);
644 else
645 entry = netlbl_domhsh_search_def(domain);
646 ret_val = netlbl_domhsh_remove_entry(entry, audit_info);
647 rcu_read_unlock();
648
649 return ret_val;
650}
651
652/**
653 * netlbl_domhsh_remove_default - Removes the default entry from the table
654 * @audit_info: NetLabel audit information
655 *
656 * Description:
657 * Removes/resets the default entry for the domain hash table and handles any
658 * updates to the lower level protocol handler (i.e. CIPSO). Returns zero on
659 * success, non-zero on failure.
660 *
661 */
662int netlbl_domhsh_remove_default(struct netlbl_audit *audit_info)
663{
664 return netlbl_domhsh_remove(NULL, audit_info);
665}
666
667/**
668 * netlbl_domhsh_getentry - Get an entry from the domain hash table
669 * @domain: the domain name to search for
670 *
671 * Description:
672 * Look through the domain hash table searching for an entry to match @domain,
673 * return a pointer to a copy of the entry or NULL. The caller is responsible
674 * for ensuring that rcu_read_[un]lock() is called.
675 *
676 */
677struct netlbl_dom_map *netlbl_domhsh_getentry(const char *domain)
678{
679 return netlbl_domhsh_search_def(domain);
680}
681
682/**
683 * netlbl_domhsh_getentry_af4 - Get an entry from the domain hash table
684 * @domain: the domain name to search for
685 * @addr: the IP address to search for
686 *
687 * Description:
688 * Look through the domain hash table searching for an entry to match @domain
689 * and @addr, return a pointer to a copy of the entry or NULL. The caller is
690 * responsible for ensuring that rcu_read_[un]lock() is called.
691 *
692 */
693struct netlbl_dommap_def *netlbl_domhsh_getentry_af4(const char *domain,
694 __be32 addr)
695{
696 struct netlbl_dom_map *dom_iter;
697 struct netlbl_af4list *addr_iter;
698
699 dom_iter = netlbl_domhsh_search_def(domain);
700 if (dom_iter == NULL)
701 return NULL;
702
703 if (dom_iter->def.type != NETLBL_NLTYPE_ADDRSELECT)
704 return &dom_iter->def;
705 addr_iter = netlbl_af4list_search(addr, &dom_iter->def.addrsel->list4);
706 if (addr_iter == NULL)
707 return NULL;
708 return &(netlbl_domhsh_addr4_entry(addr_iter)->def);
709}
710
711#if IS_ENABLED(CONFIG_IPV6)
712/**
713 * netlbl_domhsh_getentry_af6 - Get an entry from the domain hash table
714 * @domain: the domain name to search for
715 * @addr: the IP address to search for
716 *
717 * Description:
718 * Look through the domain hash table searching for an entry to match @domain
719 * and @addr, return a pointer to a copy of the entry or NULL. The caller is
720 * responsible for ensuring that rcu_read_[un]lock() is called.
721 *
722 */
723struct netlbl_dommap_def *netlbl_domhsh_getentry_af6(const char *domain,
724 const struct in6_addr *addr)
725{
726 struct netlbl_dom_map *dom_iter;
727 struct netlbl_af6list *addr_iter;
728
729 dom_iter = netlbl_domhsh_search_def(domain);
730 if (dom_iter == NULL)
731 return NULL;
732
733 if (dom_iter->def.type != NETLBL_NLTYPE_ADDRSELECT)
734 return &dom_iter->def;
735 addr_iter = netlbl_af6list_search(addr, &dom_iter->def.addrsel->list6);
736 if (addr_iter == NULL)
737 return NULL;
738 return &(netlbl_domhsh_addr6_entry(addr_iter)->def);
739}
740#endif /* IPv6 */
741
742/**
743 * netlbl_domhsh_walk - Iterate through the domain mapping hash table
744 * @skip_bkt: the number of buckets to skip at the start
745 * @skip_chain: the number of entries to skip in the first iterated bucket
746 * @callback: callback for each entry
747 * @cb_arg: argument for the callback function
748 *
749 * Description:
750 * Interate over the domain mapping hash table, skipping the first @skip_bkt
751 * buckets and @skip_chain entries. For each entry in the table call
752 * @callback, if @callback returns a negative value stop 'walking' through the
753 * table and return. Updates the values in @skip_bkt and @skip_chain on
754 * return. Returns zero on success, negative values on failure.
755 *
756 */
757int netlbl_domhsh_walk(u32 *skip_bkt,
758 u32 *skip_chain,
759 int (*callback) (struct netlbl_dom_map *entry, void *arg),
760 void *cb_arg)
761{
762 int ret_val = -ENOENT;
763 u32 iter_bkt;
764 struct list_head *iter_list;
765 struct netlbl_dom_map *iter_entry;
766 u32 chain_cnt = 0;
767
768 rcu_read_lock();
769 for (iter_bkt = *skip_bkt;
770 iter_bkt < rcu_dereference(netlbl_domhsh)->size;
771 iter_bkt++, chain_cnt = 0) {
772 iter_list = &rcu_dereference(netlbl_domhsh)->tbl[iter_bkt];
773 list_for_each_entry_rcu(iter_entry, iter_list, list)
774 if (iter_entry->valid) {
775 if (chain_cnt++ < *skip_chain)
776 continue;
777 ret_val = callback(iter_entry, cb_arg);
778 if (ret_val < 0) {
779 chain_cnt--;
780 goto walk_return;
781 }
782 }
783 }
784
785walk_return:
786 rcu_read_unlock();
787 *skip_bkt = iter_bkt;
788 *skip_chain = chain_cnt;
789 return ret_val;
790}