Loading...
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * NetLabel Domain Hash Table
4 *
5 * This file manages the domain hash table that NetLabel uses to determine
6 * which network labeling protocol to use for a given domain. The NetLabel
7 * system manages static and dynamic label mappings for network protocols such
8 * as CIPSO and RIPSO.
9 *
10 * Author: Paul Moore <paul@paul-moore.com>
11 */
12
13/*
14 * (c) Copyright Hewlett-Packard Development Company, L.P., 2006, 2008
15 */
16
17#include <linux/types.h>
18#include <linux/rculist.h>
19#include <linux/skbuff.h>
20#include <linux/spinlock.h>
21#include <linux/string.h>
22#include <linux/audit.h>
23#include <linux/slab.h>
24#include <net/netlabel.h>
25#include <net/cipso_ipv4.h>
26#include <net/calipso.h>
27#include <asm/bug.h>
28
29#include "netlabel_mgmt.h"
30#include "netlabel_addrlist.h"
31#include "netlabel_calipso.h"
32#include "netlabel_domainhash.h"
33#include "netlabel_user.h"
34
35struct netlbl_domhsh_tbl {
36 struct list_head *tbl;
37 u32 size;
38};
39
40/* Domain hash table */
41/* updates should be so rare that having one spinlock for the entire hash table
42 * should be okay */
43static DEFINE_SPINLOCK(netlbl_domhsh_lock);
44#define netlbl_domhsh_rcu_deref(p) \
45 rcu_dereference_check(p, lockdep_is_held(&netlbl_domhsh_lock))
46static struct netlbl_domhsh_tbl __rcu *netlbl_domhsh;
47static struct netlbl_dom_map __rcu *netlbl_domhsh_def_ipv4;
48static struct netlbl_dom_map __rcu *netlbl_domhsh_def_ipv6;
49
50/*
51 * Domain Hash Table Helper Functions
52 */
53
54/**
55 * netlbl_domhsh_free_entry - Frees a domain hash table entry
56 * @entry: the entry's RCU field
57 *
58 * Description:
59 * This function is designed to be used as a callback to the call_rcu()
60 * function so that the memory allocated to a hash table entry can be released
61 * safely.
62 *
63 */
64static void netlbl_domhsh_free_entry(struct rcu_head *entry)
65{
66 struct netlbl_dom_map *ptr;
67 struct netlbl_af4list *iter4;
68 struct netlbl_af4list *tmp4;
69#if IS_ENABLED(CONFIG_IPV6)
70 struct netlbl_af6list *iter6;
71 struct netlbl_af6list *tmp6;
72#endif /* IPv6 */
73
74 ptr = container_of(entry, struct netlbl_dom_map, rcu);
75 if (ptr->def.type == NETLBL_NLTYPE_ADDRSELECT) {
76 netlbl_af4list_foreach_safe(iter4, tmp4,
77 &ptr->def.addrsel->list4) {
78 netlbl_af4list_remove_entry(iter4);
79 kfree(netlbl_domhsh_addr4_entry(iter4));
80 }
81#if IS_ENABLED(CONFIG_IPV6)
82 netlbl_af6list_foreach_safe(iter6, tmp6,
83 &ptr->def.addrsel->list6) {
84 netlbl_af6list_remove_entry(iter6);
85 kfree(netlbl_domhsh_addr6_entry(iter6));
86 }
87#endif /* IPv6 */
88 kfree(ptr->def.addrsel);
89 }
90 kfree(ptr->domain);
91 kfree(ptr);
92}
93
94/**
95 * netlbl_domhsh_hash - Hashing function for the domain hash table
96 * @key: the domain name to hash
97 *
98 * Description:
99 * This is the hashing function for the domain hash table, it returns the
100 * correct bucket number for the domain. The caller is responsible for
101 * ensuring that the hash table is protected with either a RCU read lock or the
102 * hash table lock.
103 *
104 */
105static u32 netlbl_domhsh_hash(const char *key)
106{
107 u32 iter;
108 u32 val;
109 u32 len;
110
111 /* This is taken (with slight modification) from
112 * security/selinux/ss/symtab.c:symhash() */
113
114 for (iter = 0, val = 0, len = strlen(key); iter < len; iter++)
115 val = (val << 4 | (val >> (8 * sizeof(u32) - 4))) ^ key[iter];
116 return val & (netlbl_domhsh_rcu_deref(netlbl_domhsh)->size - 1);
117}
118
119static bool netlbl_family_match(u16 f1, u16 f2)
120{
121 return (f1 == f2) || (f1 == AF_UNSPEC) || (f2 == AF_UNSPEC);
122}
123
124/**
125 * netlbl_domhsh_search - Search for a domain entry
126 * @domain: the domain
127 * @family: the address family
128 *
129 * Description:
130 * Searches the domain hash table and returns a pointer to the hash table
131 * entry if found, otherwise NULL is returned. @family may be %AF_UNSPEC
132 * which matches any address family entries. The caller is responsible for
133 * ensuring that the hash table is protected with either a RCU read lock or the
134 * hash table lock.
135 *
136 */
137static struct netlbl_dom_map *netlbl_domhsh_search(const char *domain,
138 u16 family)
139{
140 u32 bkt;
141 struct list_head *bkt_list;
142 struct netlbl_dom_map *iter;
143
144 if (domain != NULL) {
145 bkt = netlbl_domhsh_hash(domain);
146 bkt_list = &netlbl_domhsh_rcu_deref(netlbl_domhsh)->tbl[bkt];
147 list_for_each_entry_rcu(iter, bkt_list, list,
148 lockdep_is_held(&netlbl_domhsh_lock))
149 if (iter->valid &&
150 netlbl_family_match(iter->family, family) &&
151 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 * @family: the address family
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. @family may be %AF_UNSPEC which matches any address family
168 * entries. The caller is responsible ensuring that the hash table is
169 * protected with either a RCU read lock or the hash table lock.
170 *
171 */
172static struct netlbl_dom_map *netlbl_domhsh_search_def(const char *domain,
173 u16 family)
174{
175 struct netlbl_dom_map *entry;
176
177 entry = netlbl_domhsh_search(domain, family);
178 if (entry != NULL)
179 return entry;
180 if (family == AF_INET || family == AF_UNSPEC) {
181 entry = netlbl_domhsh_rcu_deref(netlbl_domhsh_def_ipv4);
182 if (entry != NULL && entry->valid)
183 return entry;
184 }
185 if (family == AF_INET6 || family == AF_UNSPEC) {
186 entry = netlbl_domhsh_rcu_deref(netlbl_domhsh_def_ipv6);
187 if (entry != NULL && entry->valid)
188 return entry;
189 }
190
191 return NULL;
192}
193
194/**
195 * netlbl_domhsh_audit_add - Generate an audit entry for an add event
196 * @entry: the entry being added
197 * @addr4: the IPv4 address information
198 * @addr6: the IPv6 address information
199 * @result: the result code
200 * @audit_info: NetLabel audit information
201 *
202 * Description:
203 * Generate an audit record for adding a new NetLabel/LSM mapping entry with
204 * the given information. Caller is responsible for holding the necessary
205 * locks.
206 *
207 */
208static void netlbl_domhsh_audit_add(struct netlbl_dom_map *entry,
209 struct netlbl_af4list *addr4,
210 struct netlbl_af6list *addr6,
211 int result,
212 struct netlbl_audit *audit_info)
213{
214 struct audit_buffer *audit_buf;
215 struct cipso_v4_doi *cipsov4 = NULL;
216 struct calipso_doi *calipso = NULL;
217 u32 type;
218
219 audit_buf = netlbl_audit_start_common(AUDIT_MAC_MAP_ADD, audit_info);
220 if (audit_buf != NULL) {
221 audit_log_format(audit_buf, " nlbl_domain=%s",
222 entry->domain ? entry->domain : "(default)");
223 if (addr4 != NULL) {
224 struct netlbl_domaddr4_map *map4;
225 map4 = netlbl_domhsh_addr4_entry(addr4);
226 type = map4->def.type;
227 cipsov4 = map4->def.cipso;
228 netlbl_af4list_audit_addr(audit_buf, 0, NULL,
229 addr4->addr, addr4->mask);
230#if IS_ENABLED(CONFIG_IPV6)
231 } else if (addr6 != NULL) {
232 struct netlbl_domaddr6_map *map6;
233 map6 = netlbl_domhsh_addr6_entry(addr6);
234 type = map6->def.type;
235 calipso = map6->def.calipso;
236 netlbl_af6list_audit_addr(audit_buf, 0, NULL,
237 &addr6->addr, &addr6->mask);
238#endif /* IPv6 */
239 } else {
240 type = entry->def.type;
241 cipsov4 = entry->def.cipso;
242 calipso = entry->def.calipso;
243 }
244 switch (type) {
245 case NETLBL_NLTYPE_UNLABELED:
246 audit_log_format(audit_buf, " nlbl_protocol=unlbl");
247 break;
248 case NETLBL_NLTYPE_CIPSOV4:
249 BUG_ON(cipsov4 == NULL);
250 audit_log_format(audit_buf,
251 " nlbl_protocol=cipsov4 cipso_doi=%u",
252 cipsov4->doi);
253 break;
254 case NETLBL_NLTYPE_CALIPSO:
255 BUG_ON(calipso == NULL);
256 audit_log_format(audit_buf,
257 " nlbl_protocol=calipso calipso_doi=%u",
258 calipso->doi);
259 break;
260 }
261 audit_log_format(audit_buf, " res=%u", result == 0 ? 1 : 0);
262 audit_log_end(audit_buf);
263 }
264}
265
266/**
267 * netlbl_domhsh_validate - Validate a new domain mapping entry
268 * @entry: the entry to validate
269 *
270 * This function validates the new domain mapping entry to ensure that it is
271 * a valid entry. Returns zero on success, negative values on failure.
272 *
273 */
274static int netlbl_domhsh_validate(const struct netlbl_dom_map *entry)
275{
276 struct netlbl_af4list *iter4;
277 struct netlbl_domaddr4_map *map4;
278#if IS_ENABLED(CONFIG_IPV6)
279 struct netlbl_af6list *iter6;
280 struct netlbl_domaddr6_map *map6;
281#endif /* IPv6 */
282
283 if (entry == NULL)
284 return -EINVAL;
285
286 if (entry->family != AF_INET && entry->family != AF_INET6 &&
287 (entry->family != AF_UNSPEC ||
288 entry->def.type != NETLBL_NLTYPE_UNLABELED))
289 return -EINVAL;
290
291 switch (entry->def.type) {
292 case NETLBL_NLTYPE_UNLABELED:
293 if (entry->def.cipso != NULL || entry->def.calipso != NULL ||
294 entry->def.addrsel != NULL)
295 return -EINVAL;
296 break;
297 case NETLBL_NLTYPE_CIPSOV4:
298 if (entry->family != AF_INET ||
299 entry->def.cipso == NULL)
300 return -EINVAL;
301 break;
302 case NETLBL_NLTYPE_CALIPSO:
303 if (entry->family != AF_INET6 ||
304 entry->def.calipso == NULL)
305 return -EINVAL;
306 break;
307 case NETLBL_NLTYPE_ADDRSELECT:
308 netlbl_af4list_foreach(iter4, &entry->def.addrsel->list4) {
309 map4 = netlbl_domhsh_addr4_entry(iter4);
310 switch (map4->def.type) {
311 case NETLBL_NLTYPE_UNLABELED:
312 if (map4->def.cipso != NULL)
313 return -EINVAL;
314 break;
315 case NETLBL_NLTYPE_CIPSOV4:
316 if (map4->def.cipso == NULL)
317 return -EINVAL;
318 break;
319 default:
320 return -EINVAL;
321 }
322 }
323#if IS_ENABLED(CONFIG_IPV6)
324 netlbl_af6list_foreach(iter6, &entry->def.addrsel->list6) {
325 map6 = netlbl_domhsh_addr6_entry(iter6);
326 switch (map6->def.type) {
327 case NETLBL_NLTYPE_UNLABELED:
328 if (map6->def.calipso != NULL)
329 return -EINVAL;
330 break;
331 case NETLBL_NLTYPE_CALIPSO:
332 if (map6->def.calipso == NULL)
333 return -EINVAL;
334 break;
335 default:
336 return -EINVAL;
337 }
338 }
339#endif /* IPv6 */
340 break;
341 default:
342 return -EINVAL;
343 }
344
345 return 0;
346}
347
348/*
349 * Domain Hash Table Functions
350 */
351
352/**
353 * netlbl_domhsh_init - Init for the domain hash
354 * @size: the number of bits to use for the hash buckets
355 *
356 * Description:
357 * Initializes the domain hash table, should be called only by
358 * netlbl_user_init() during initialization. Returns zero on success, non-zero
359 * values on error.
360 *
361 */
362int __init netlbl_domhsh_init(u32 size)
363{
364 u32 iter;
365 struct netlbl_domhsh_tbl *hsh_tbl;
366
367 if (size == 0)
368 return -EINVAL;
369
370 hsh_tbl = kmalloc(sizeof(*hsh_tbl), GFP_KERNEL);
371 if (hsh_tbl == NULL)
372 return -ENOMEM;
373 hsh_tbl->size = 1 << size;
374 hsh_tbl->tbl = kcalloc(hsh_tbl->size,
375 sizeof(struct list_head),
376 GFP_KERNEL);
377 if (hsh_tbl->tbl == NULL) {
378 kfree(hsh_tbl);
379 return -ENOMEM;
380 }
381 for (iter = 0; iter < hsh_tbl->size; iter++)
382 INIT_LIST_HEAD(&hsh_tbl->tbl[iter]);
383
384 spin_lock(&netlbl_domhsh_lock);
385 rcu_assign_pointer(netlbl_domhsh, hsh_tbl);
386 spin_unlock(&netlbl_domhsh_lock);
387
388 return 0;
389}
390
391/**
392 * netlbl_domhsh_add - Adds a entry to the domain hash table
393 * @entry: the entry to add
394 * @audit_info: NetLabel audit information
395 *
396 * Description:
397 * Adds a new entry to the domain hash table and handles any updates to the
398 * lower level protocol handler (i.e. CIPSO). @entry->family may be set to
399 * %AF_UNSPEC which will add an entry that matches all address families. This
400 * is only useful for the unlabelled type and will only succeed if there is no
401 * existing entry for any address family with the same domain. Returns zero
402 * on success, negative on failure.
403 *
404 */
405int netlbl_domhsh_add(struct netlbl_dom_map *entry,
406 struct netlbl_audit *audit_info)
407{
408 int ret_val = 0;
409 struct netlbl_dom_map *entry_old, *entry_b;
410 struct netlbl_af4list *iter4;
411 struct netlbl_af4list *tmp4;
412#if IS_ENABLED(CONFIG_IPV6)
413 struct netlbl_af6list *iter6;
414 struct netlbl_af6list *tmp6;
415#endif /* IPv6 */
416
417 ret_val = netlbl_domhsh_validate(entry);
418 if (ret_val != 0)
419 return ret_val;
420
421 /* XXX - we can remove this RCU read lock as the spinlock protects the
422 * entire function, but before we do we need to fixup the
423 * netlbl_af[4,6]list RCU functions to do "the right thing" with
424 * respect to rcu_dereference() when only a spinlock is held. */
425 rcu_read_lock();
426 spin_lock(&netlbl_domhsh_lock);
427 if (entry->domain != NULL)
428 entry_old = netlbl_domhsh_search(entry->domain, entry->family);
429 else
430 entry_old = netlbl_domhsh_search_def(entry->domain,
431 entry->family);
432 if (entry_old == NULL) {
433 entry->valid = 1;
434
435 if (entry->domain != NULL) {
436 u32 bkt = netlbl_domhsh_hash(entry->domain);
437 list_add_tail_rcu(&entry->list,
438 &rcu_dereference(netlbl_domhsh)->tbl[bkt]);
439 } else {
440 INIT_LIST_HEAD(&entry->list);
441 switch (entry->family) {
442 case AF_INET:
443 rcu_assign_pointer(netlbl_domhsh_def_ipv4,
444 entry);
445 break;
446 case AF_INET6:
447 rcu_assign_pointer(netlbl_domhsh_def_ipv6,
448 entry);
449 break;
450 case AF_UNSPEC:
451 if (entry->def.type !=
452 NETLBL_NLTYPE_UNLABELED) {
453 ret_val = -EINVAL;
454 goto add_return;
455 }
456 entry_b = kzalloc(sizeof(*entry_b), GFP_ATOMIC);
457 if (entry_b == NULL) {
458 ret_val = -ENOMEM;
459 goto add_return;
460 }
461 entry_b->family = AF_INET6;
462 entry_b->def.type = NETLBL_NLTYPE_UNLABELED;
463 entry_b->valid = 1;
464 entry->family = AF_INET;
465 rcu_assign_pointer(netlbl_domhsh_def_ipv4,
466 entry);
467 rcu_assign_pointer(netlbl_domhsh_def_ipv6,
468 entry_b);
469 break;
470 default:
471 /* Already checked in
472 * netlbl_domhsh_validate(). */
473 ret_val = -EINVAL;
474 goto add_return;
475 }
476 }
477
478 if (entry->def.type == NETLBL_NLTYPE_ADDRSELECT) {
479 netlbl_af4list_foreach_rcu(iter4,
480 &entry->def.addrsel->list4)
481 netlbl_domhsh_audit_add(entry, iter4, NULL,
482 ret_val, audit_info);
483#if IS_ENABLED(CONFIG_IPV6)
484 netlbl_af6list_foreach_rcu(iter6,
485 &entry->def.addrsel->list6)
486 netlbl_domhsh_audit_add(entry, NULL, iter6,
487 ret_val, audit_info);
488#endif /* IPv6 */
489 } else
490 netlbl_domhsh_audit_add(entry, NULL, NULL,
491 ret_val, audit_info);
492 } else if (entry_old->def.type == NETLBL_NLTYPE_ADDRSELECT &&
493 entry->def.type == NETLBL_NLTYPE_ADDRSELECT) {
494 struct list_head *old_list4;
495 struct list_head *old_list6;
496
497 old_list4 = &entry_old->def.addrsel->list4;
498 old_list6 = &entry_old->def.addrsel->list6;
499
500 /* we only allow the addition of address selectors if all of
501 * the selectors do not exist in the existing domain map */
502 netlbl_af4list_foreach_rcu(iter4, &entry->def.addrsel->list4)
503 if (netlbl_af4list_search_exact(iter4->addr,
504 iter4->mask,
505 old_list4)) {
506 ret_val = -EEXIST;
507 goto add_return;
508 }
509#if IS_ENABLED(CONFIG_IPV6)
510 netlbl_af6list_foreach_rcu(iter6, &entry->def.addrsel->list6)
511 if (netlbl_af6list_search_exact(&iter6->addr,
512 &iter6->mask,
513 old_list6)) {
514 ret_val = -EEXIST;
515 goto add_return;
516 }
517#endif /* IPv6 */
518
519 netlbl_af4list_foreach_safe(iter4, tmp4,
520 &entry->def.addrsel->list4) {
521 netlbl_af4list_remove_entry(iter4);
522 iter4->valid = 1;
523 ret_val = netlbl_af4list_add(iter4, old_list4);
524 netlbl_domhsh_audit_add(entry_old, iter4, NULL,
525 ret_val, audit_info);
526 if (ret_val != 0)
527 goto add_return;
528 }
529#if IS_ENABLED(CONFIG_IPV6)
530 netlbl_af6list_foreach_safe(iter6, tmp6,
531 &entry->def.addrsel->list6) {
532 netlbl_af6list_remove_entry(iter6);
533 iter6->valid = 1;
534 ret_val = netlbl_af6list_add(iter6, old_list6);
535 netlbl_domhsh_audit_add(entry_old, NULL, iter6,
536 ret_val, audit_info);
537 if (ret_val != 0)
538 goto add_return;
539 }
540#endif /* IPv6 */
541 /* cleanup the new entry since we've moved everything over */
542 netlbl_domhsh_free_entry(&entry->rcu);
543 } else
544 ret_val = -EINVAL;
545
546add_return:
547 spin_unlock(&netlbl_domhsh_lock);
548 rcu_read_unlock();
549 return ret_val;
550}
551
552/**
553 * netlbl_domhsh_add_default - Adds the default entry to the domain hash table
554 * @entry: the entry to add
555 * @audit_info: NetLabel audit information
556 *
557 * Description:
558 * Adds a new default entry to the domain hash table and handles any updates
559 * to the lower level protocol handler (i.e. CIPSO). Returns zero on success,
560 * negative on failure.
561 *
562 */
563int netlbl_domhsh_add_default(struct netlbl_dom_map *entry,
564 struct netlbl_audit *audit_info)
565{
566 return netlbl_domhsh_add(entry, audit_info);
567}
568
569/**
570 * netlbl_domhsh_remove_entry - Removes a given entry from the domain table
571 * @entry: the entry to remove
572 * @audit_info: NetLabel audit information
573 *
574 * Description:
575 * Removes an entry from the domain hash table and handles any updates to the
576 * lower level protocol handler (i.e. CIPSO). Caller is responsible for
577 * ensuring that the RCU read lock is held. Returns zero on success, negative
578 * on failure.
579 *
580 */
581int netlbl_domhsh_remove_entry(struct netlbl_dom_map *entry,
582 struct netlbl_audit *audit_info)
583{
584 int ret_val = 0;
585 struct audit_buffer *audit_buf;
586 struct netlbl_af4list *iter4;
587 struct netlbl_domaddr4_map *map4;
588#if IS_ENABLED(CONFIG_IPV6)
589 struct netlbl_af6list *iter6;
590 struct netlbl_domaddr6_map *map6;
591#endif /* IPv6 */
592
593 if (entry == NULL)
594 return -ENOENT;
595
596 spin_lock(&netlbl_domhsh_lock);
597 if (entry->valid) {
598 entry->valid = 0;
599 if (entry == rcu_dereference(netlbl_domhsh_def_ipv4))
600 RCU_INIT_POINTER(netlbl_domhsh_def_ipv4, NULL);
601 else if (entry == rcu_dereference(netlbl_domhsh_def_ipv6))
602 RCU_INIT_POINTER(netlbl_domhsh_def_ipv6, NULL);
603 else
604 list_del_rcu(&entry->list);
605 } else
606 ret_val = -ENOENT;
607 spin_unlock(&netlbl_domhsh_lock);
608
609 if (ret_val)
610 return ret_val;
611
612 audit_buf = netlbl_audit_start_common(AUDIT_MAC_MAP_DEL, audit_info);
613 if (audit_buf != NULL) {
614 audit_log_format(audit_buf,
615 " nlbl_domain=%s res=1",
616 entry->domain ? entry->domain : "(default)");
617 audit_log_end(audit_buf);
618 }
619
620 switch (entry->def.type) {
621 case NETLBL_NLTYPE_ADDRSELECT:
622 netlbl_af4list_foreach_rcu(iter4, &entry->def.addrsel->list4) {
623 map4 = netlbl_domhsh_addr4_entry(iter4);
624 cipso_v4_doi_putdef(map4->def.cipso);
625 }
626#if IS_ENABLED(CONFIG_IPV6)
627 netlbl_af6list_foreach_rcu(iter6, &entry->def.addrsel->list6) {
628 map6 = netlbl_domhsh_addr6_entry(iter6);
629 calipso_doi_putdef(map6->def.calipso);
630 }
631#endif /* IPv6 */
632 break;
633 case NETLBL_NLTYPE_CIPSOV4:
634 cipso_v4_doi_putdef(entry->def.cipso);
635 break;
636#if IS_ENABLED(CONFIG_IPV6)
637 case NETLBL_NLTYPE_CALIPSO:
638 calipso_doi_putdef(entry->def.calipso);
639 break;
640#endif /* IPv6 */
641 }
642 call_rcu(&entry->rcu, netlbl_domhsh_free_entry);
643
644 return ret_val;
645}
646
647/**
648 * netlbl_domhsh_remove_af4 - Removes an address selector entry
649 * @domain: the domain
650 * @addr: IPv4 address
651 * @mask: IPv4 address mask
652 * @audit_info: NetLabel audit information
653 *
654 * Description:
655 * Removes an individual address selector from a domain mapping and potentially
656 * the entire mapping if it is empty. Returns zero on success, negative values
657 * on failure.
658 *
659 */
660int netlbl_domhsh_remove_af4(const char *domain,
661 const struct in_addr *addr,
662 const struct in_addr *mask,
663 struct netlbl_audit *audit_info)
664{
665 struct netlbl_dom_map *entry_map;
666 struct netlbl_af4list *entry_addr;
667 struct netlbl_af4list *iter4;
668#if IS_ENABLED(CONFIG_IPV6)
669 struct netlbl_af6list *iter6;
670#endif /* IPv6 */
671 struct netlbl_domaddr4_map *entry;
672
673 rcu_read_lock();
674
675 if (domain)
676 entry_map = netlbl_domhsh_search(domain, AF_INET);
677 else
678 entry_map = netlbl_domhsh_search_def(domain, AF_INET);
679 if (entry_map == NULL ||
680 entry_map->def.type != NETLBL_NLTYPE_ADDRSELECT)
681 goto remove_af4_failure;
682
683 spin_lock(&netlbl_domhsh_lock);
684 entry_addr = netlbl_af4list_remove(addr->s_addr, mask->s_addr,
685 &entry_map->def.addrsel->list4);
686 spin_unlock(&netlbl_domhsh_lock);
687
688 if (entry_addr == NULL)
689 goto remove_af4_failure;
690 netlbl_af4list_foreach_rcu(iter4, &entry_map->def.addrsel->list4)
691 goto remove_af4_single_addr;
692#if IS_ENABLED(CONFIG_IPV6)
693 netlbl_af6list_foreach_rcu(iter6, &entry_map->def.addrsel->list6)
694 goto remove_af4_single_addr;
695#endif /* IPv6 */
696 /* the domain mapping is empty so remove it from the mapping table */
697 netlbl_domhsh_remove_entry(entry_map, audit_info);
698
699remove_af4_single_addr:
700 rcu_read_unlock();
701 /* yick, we can't use call_rcu here because we don't have a rcu head
702 * pointer but hopefully this should be a rare case so the pause
703 * shouldn't be a problem */
704 synchronize_rcu();
705 entry = netlbl_domhsh_addr4_entry(entry_addr);
706 cipso_v4_doi_putdef(entry->def.cipso);
707 kfree(entry);
708 return 0;
709
710remove_af4_failure:
711 rcu_read_unlock();
712 return -ENOENT;
713}
714
715#if IS_ENABLED(CONFIG_IPV6)
716/**
717 * netlbl_domhsh_remove_af6 - Removes an address selector entry
718 * @domain: the domain
719 * @addr: IPv6 address
720 * @mask: IPv6 address mask
721 * @audit_info: NetLabel audit information
722 *
723 * Description:
724 * Removes an individual address selector from a domain mapping and potentially
725 * the entire mapping if it is empty. Returns zero on success, negative values
726 * on failure.
727 *
728 */
729int netlbl_domhsh_remove_af6(const char *domain,
730 const struct in6_addr *addr,
731 const struct in6_addr *mask,
732 struct netlbl_audit *audit_info)
733{
734 struct netlbl_dom_map *entry_map;
735 struct netlbl_af6list *entry_addr;
736 struct netlbl_af4list *iter4;
737 struct netlbl_af6list *iter6;
738 struct netlbl_domaddr6_map *entry;
739
740 rcu_read_lock();
741
742 if (domain)
743 entry_map = netlbl_domhsh_search(domain, AF_INET6);
744 else
745 entry_map = netlbl_domhsh_search_def(domain, AF_INET6);
746 if (entry_map == NULL ||
747 entry_map->def.type != NETLBL_NLTYPE_ADDRSELECT)
748 goto remove_af6_failure;
749
750 spin_lock(&netlbl_domhsh_lock);
751 entry_addr = netlbl_af6list_remove(addr, mask,
752 &entry_map->def.addrsel->list6);
753 spin_unlock(&netlbl_domhsh_lock);
754
755 if (entry_addr == NULL)
756 goto remove_af6_failure;
757 netlbl_af4list_foreach_rcu(iter4, &entry_map->def.addrsel->list4)
758 goto remove_af6_single_addr;
759 netlbl_af6list_foreach_rcu(iter6, &entry_map->def.addrsel->list6)
760 goto remove_af6_single_addr;
761 /* the domain mapping is empty so remove it from the mapping table */
762 netlbl_domhsh_remove_entry(entry_map, audit_info);
763
764remove_af6_single_addr:
765 rcu_read_unlock();
766 /* yick, we can't use call_rcu here because we don't have a rcu head
767 * pointer but hopefully this should be a rare case so the pause
768 * shouldn't be a problem */
769 synchronize_rcu();
770 entry = netlbl_domhsh_addr6_entry(entry_addr);
771 calipso_doi_putdef(entry->def.calipso);
772 kfree(entry);
773 return 0;
774
775remove_af6_failure:
776 rcu_read_unlock();
777 return -ENOENT;
778}
779#endif /* IPv6 */
780
781/**
782 * netlbl_domhsh_remove - Removes an entry from the domain hash table
783 * @domain: the domain to remove
784 * @family: address family
785 * @audit_info: NetLabel audit information
786 *
787 * Description:
788 * Removes an entry from the domain hash table and handles any updates to the
789 * lower level protocol handler (i.e. CIPSO). @family may be %AF_UNSPEC which
790 * removes all address family entries. Returns zero on success, negative on
791 * failure.
792 *
793 */
794int netlbl_domhsh_remove(const char *domain, u16 family,
795 struct netlbl_audit *audit_info)
796{
797 int ret_val = -EINVAL;
798 struct netlbl_dom_map *entry;
799
800 rcu_read_lock();
801
802 if (family == AF_INET || family == AF_UNSPEC) {
803 if (domain)
804 entry = netlbl_domhsh_search(domain, AF_INET);
805 else
806 entry = netlbl_domhsh_search_def(domain, AF_INET);
807 ret_val = netlbl_domhsh_remove_entry(entry, audit_info);
808 if (ret_val && ret_val != -ENOENT)
809 goto done;
810 }
811 if (family == AF_INET6 || family == AF_UNSPEC) {
812 int ret_val2;
813
814 if (domain)
815 entry = netlbl_domhsh_search(domain, AF_INET6);
816 else
817 entry = netlbl_domhsh_search_def(domain, AF_INET6);
818 ret_val2 = netlbl_domhsh_remove_entry(entry, audit_info);
819 if (ret_val2 != -ENOENT)
820 ret_val = ret_val2;
821 }
822done:
823 rcu_read_unlock();
824
825 return ret_val;
826}
827
828/**
829 * netlbl_domhsh_remove_default - Removes the default entry from the table
830 * @family: address family
831 * @audit_info: NetLabel audit information
832 *
833 * Description:
834 * Removes/resets the default entry corresponding to @family from the domain
835 * hash table and handles any updates to the lower level protocol handler
836 * (i.e. CIPSO). @family may be %AF_UNSPEC which removes all address family
837 * entries. Returns zero on success, negative on failure.
838 *
839 */
840int netlbl_domhsh_remove_default(u16 family, struct netlbl_audit *audit_info)
841{
842 return netlbl_domhsh_remove(NULL, family, audit_info);
843}
844
845/**
846 * netlbl_domhsh_getentry - Get an entry from the domain hash table
847 * @domain: the domain name to search for
848 * @family: address family
849 *
850 * Description:
851 * Look through the domain hash table searching for an entry to match @domain,
852 * with address family @family, return a pointer to a copy of the entry or
853 * NULL. The caller is responsible for ensuring that rcu_read_[un]lock() is
854 * called.
855 *
856 */
857struct netlbl_dom_map *netlbl_domhsh_getentry(const char *domain, u16 family)
858{
859 if (family == AF_UNSPEC)
860 return NULL;
861 return netlbl_domhsh_search_def(domain, family);
862}
863
864/**
865 * netlbl_domhsh_getentry_af4 - Get an entry from the domain hash table
866 * @domain: the domain name to search for
867 * @addr: the IP address to search for
868 *
869 * Description:
870 * Look through the domain hash table searching for an entry to match @domain
871 * and @addr, return a pointer to a copy of the entry or NULL. The caller is
872 * responsible for ensuring that rcu_read_[un]lock() is called.
873 *
874 */
875struct netlbl_dommap_def *netlbl_domhsh_getentry_af4(const char *domain,
876 __be32 addr)
877{
878 struct netlbl_dom_map *dom_iter;
879 struct netlbl_af4list *addr_iter;
880
881 dom_iter = netlbl_domhsh_search_def(domain, AF_INET);
882 if (dom_iter == NULL)
883 return NULL;
884
885 if (dom_iter->def.type != NETLBL_NLTYPE_ADDRSELECT)
886 return &dom_iter->def;
887 addr_iter = netlbl_af4list_search(addr, &dom_iter->def.addrsel->list4);
888 if (addr_iter == NULL)
889 return NULL;
890 return &(netlbl_domhsh_addr4_entry(addr_iter)->def);
891}
892
893#if IS_ENABLED(CONFIG_IPV6)
894/**
895 * netlbl_domhsh_getentry_af6 - Get an entry from the domain hash table
896 * @domain: the domain name to search for
897 * @addr: the IP address to search for
898 *
899 * Description:
900 * Look through the domain hash table searching for an entry to match @domain
901 * and @addr, return a pointer to a copy of the entry or NULL. The caller is
902 * responsible for ensuring that rcu_read_[un]lock() is called.
903 *
904 */
905struct netlbl_dommap_def *netlbl_domhsh_getentry_af6(const char *domain,
906 const struct in6_addr *addr)
907{
908 struct netlbl_dom_map *dom_iter;
909 struct netlbl_af6list *addr_iter;
910
911 dom_iter = netlbl_domhsh_search_def(domain, AF_INET6);
912 if (dom_iter == NULL)
913 return NULL;
914
915 if (dom_iter->def.type != NETLBL_NLTYPE_ADDRSELECT)
916 return &dom_iter->def;
917 addr_iter = netlbl_af6list_search(addr, &dom_iter->def.addrsel->list6);
918 if (addr_iter == NULL)
919 return NULL;
920 return &(netlbl_domhsh_addr6_entry(addr_iter)->def);
921}
922#endif /* IPv6 */
923
924/**
925 * netlbl_domhsh_walk - Iterate through the domain mapping hash table
926 * @skip_bkt: the number of buckets to skip at the start
927 * @skip_chain: the number of entries to skip in the first iterated bucket
928 * @callback: callback for each entry
929 * @cb_arg: argument for the callback function
930 *
931 * Description:
932 * Iterate over the domain mapping hash table, skipping the first @skip_bkt
933 * buckets and @skip_chain entries. For each entry in the table call
934 * @callback, if @callback returns a negative value stop 'walking' through the
935 * table and return. Updates the values in @skip_bkt and @skip_chain on
936 * return. Returns zero on success, negative values on failure.
937 *
938 */
939int netlbl_domhsh_walk(u32 *skip_bkt,
940 u32 *skip_chain,
941 int (*callback) (struct netlbl_dom_map *entry, void *arg),
942 void *cb_arg)
943{
944 int ret_val = -ENOENT;
945 u32 iter_bkt;
946 struct list_head *iter_list;
947 struct netlbl_dom_map *iter_entry;
948 u32 chain_cnt = 0;
949
950 rcu_read_lock();
951 for (iter_bkt = *skip_bkt;
952 iter_bkt < rcu_dereference(netlbl_domhsh)->size;
953 iter_bkt++, chain_cnt = 0) {
954 iter_list = &rcu_dereference(netlbl_domhsh)->tbl[iter_bkt];
955 list_for_each_entry_rcu(iter_entry, iter_list, list)
956 if (iter_entry->valid) {
957 if (chain_cnt++ < *skip_chain)
958 continue;
959 ret_val = callback(iter_entry, cb_arg);
960 if (ret_val < 0) {
961 chain_cnt--;
962 goto walk_return;
963 }
964 }
965 }
966
967walk_return:
968 rcu_read_unlock();
969 *skip_bkt = iter_bkt;
970 *skip_chain = chain_cnt;
971 return ret_val;
972}
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * NetLabel Domain Hash Table
4 *
5 * This file manages the domain hash table that NetLabel uses to determine
6 * which network labeling protocol to use for a given domain. The NetLabel
7 * system manages static and dynamic label mappings for network protocols such
8 * as CIPSO and RIPSO.
9 *
10 * Author: Paul Moore <paul@paul-moore.com>
11 */
12
13/*
14 * (c) Copyright Hewlett-Packard Development Company, L.P., 2006, 2008
15 */
16
17#include <linux/types.h>
18#include <linux/rculist.h>
19#include <linux/skbuff.h>
20#include <linux/spinlock.h>
21#include <linux/string.h>
22#include <linux/audit.h>
23#include <linux/slab.h>
24#include <net/netlabel.h>
25#include <net/cipso_ipv4.h>
26#include <net/calipso.h>
27#include <asm/bug.h>
28
29#include "netlabel_mgmt.h"
30#include "netlabel_addrlist.h"
31#include "netlabel_calipso.h"
32#include "netlabel_domainhash.h"
33#include "netlabel_user.h"
34
35struct netlbl_domhsh_tbl {
36 struct list_head *tbl;
37 u32 size;
38};
39
40/* Domain hash table */
41/* updates should be so rare that having one spinlock for the entire hash table
42 * should be okay */
43static DEFINE_SPINLOCK(netlbl_domhsh_lock);
44#define netlbl_domhsh_rcu_deref(p) \
45 rcu_dereference_check(p, lockdep_is_held(&netlbl_domhsh_lock))
46static struct netlbl_domhsh_tbl __rcu *netlbl_domhsh;
47static struct netlbl_dom_map __rcu *netlbl_domhsh_def_ipv4;
48static struct netlbl_dom_map __rcu *netlbl_domhsh_def_ipv6;
49
50/*
51 * Domain Hash Table Helper Functions
52 */
53
54/**
55 * netlbl_domhsh_free_entry - Frees a domain hash table entry
56 * @entry: the entry's RCU field
57 *
58 * Description:
59 * This function is designed to be used as a callback to the call_rcu()
60 * function so that the memory allocated to a hash table entry can be released
61 * safely.
62 *
63 */
64static void netlbl_domhsh_free_entry(struct rcu_head *entry)
65{
66 struct netlbl_dom_map *ptr;
67 struct netlbl_af4list *iter4;
68 struct netlbl_af4list *tmp4;
69#if IS_ENABLED(CONFIG_IPV6)
70 struct netlbl_af6list *iter6;
71 struct netlbl_af6list *tmp6;
72#endif /* IPv6 */
73
74 ptr = container_of(entry, struct netlbl_dom_map, rcu);
75 if (ptr->def.type == NETLBL_NLTYPE_ADDRSELECT) {
76 netlbl_af4list_foreach_safe(iter4, tmp4,
77 &ptr->def.addrsel->list4) {
78 netlbl_af4list_remove_entry(iter4);
79 kfree(netlbl_domhsh_addr4_entry(iter4));
80 }
81#if IS_ENABLED(CONFIG_IPV6)
82 netlbl_af6list_foreach_safe(iter6, tmp6,
83 &ptr->def.addrsel->list6) {
84 netlbl_af6list_remove_entry(iter6);
85 kfree(netlbl_domhsh_addr6_entry(iter6));
86 }
87#endif /* IPv6 */
88 }
89 kfree(ptr->domain);
90 kfree(ptr);
91}
92
93/**
94 * netlbl_domhsh_hash - Hashing function for the domain hash table
95 * @domain: the domain name to hash
96 *
97 * Description:
98 * This is the hashing function for the domain hash table, it returns the
99 * correct bucket number for the domain. The caller is responsible for
100 * ensuring that the hash table is protected with either a RCU read lock or the
101 * hash table lock.
102 *
103 */
104static u32 netlbl_domhsh_hash(const char *key)
105{
106 u32 iter;
107 u32 val;
108 u32 len;
109
110 /* This is taken (with slight modification) from
111 * security/selinux/ss/symtab.c:symhash() */
112
113 for (iter = 0, val = 0, len = strlen(key); iter < len; iter++)
114 val = (val << 4 | (val >> (8 * sizeof(u32) - 4))) ^ key[iter];
115 return val & (netlbl_domhsh_rcu_deref(netlbl_domhsh)->size - 1);
116}
117
118static bool netlbl_family_match(u16 f1, u16 f2)
119{
120 return (f1 == f2) || (f1 == AF_UNSPEC) || (f2 == AF_UNSPEC);
121}
122
123/**
124 * netlbl_domhsh_search - Search for a domain entry
125 * @domain: the domain
126 * @family: the address family
127 *
128 * Description:
129 * Searches the domain hash table and returns a pointer to the hash table
130 * entry if found, otherwise NULL is returned. @family may be %AF_UNSPEC
131 * which matches any address family entries. The caller is responsible for
132 * ensuring that the hash table is protected with either a RCU read lock or the
133 * hash table lock.
134 *
135 */
136static struct netlbl_dom_map *netlbl_domhsh_search(const char *domain,
137 u16 family)
138{
139 u32 bkt;
140 struct list_head *bkt_list;
141 struct netlbl_dom_map *iter;
142
143 if (domain != NULL) {
144 bkt = netlbl_domhsh_hash(domain);
145 bkt_list = &netlbl_domhsh_rcu_deref(netlbl_domhsh)->tbl[bkt];
146 list_for_each_entry_rcu(iter, bkt_list, list)
147 if (iter->valid &&
148 netlbl_family_match(iter->family, family) &&
149 strcmp(iter->domain, domain) == 0)
150 return iter;
151 }
152
153 return NULL;
154}
155
156/**
157 * netlbl_domhsh_search_def - Search for a domain entry
158 * @domain: the domain
159 * @family: the address family
160 *
161 * Description:
162 * Searches the domain hash table and returns a pointer to the hash table
163 * entry if an exact match is found, if an exact match is not present in the
164 * hash table then the default entry is returned if valid otherwise NULL is
165 * returned. @family may be %AF_UNSPEC which matches any address family
166 * entries. 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 u16 family)
172{
173 struct netlbl_dom_map *entry;
174
175 entry = netlbl_domhsh_search(domain, family);
176 if (entry != NULL)
177 return entry;
178 if (family == AF_INET || family == AF_UNSPEC) {
179 entry = netlbl_domhsh_rcu_deref(netlbl_domhsh_def_ipv4);
180 if (entry != NULL && entry->valid)
181 return entry;
182 }
183 if (family == AF_INET6 || family == AF_UNSPEC) {
184 entry = netlbl_domhsh_rcu_deref(netlbl_domhsh_def_ipv6);
185 if (entry != NULL && entry->valid)
186 return entry;
187 }
188
189 return NULL;
190}
191
192/**
193 * netlbl_domhsh_audit_add - Generate an audit entry for an add event
194 * @entry: the entry being added
195 * @addr4: the IPv4 address information
196 * @addr6: the IPv6 address information
197 * @result: the result code
198 * @audit_info: NetLabel audit information
199 *
200 * Description:
201 * Generate an audit record for adding a new NetLabel/LSM mapping entry with
202 * the given information. Caller is responsible for holding the necessary
203 * locks.
204 *
205 */
206static void netlbl_domhsh_audit_add(struct netlbl_dom_map *entry,
207 struct netlbl_af4list *addr4,
208 struct netlbl_af6list *addr6,
209 int result,
210 struct netlbl_audit *audit_info)
211{
212 struct audit_buffer *audit_buf;
213 struct cipso_v4_doi *cipsov4 = NULL;
214 struct calipso_doi *calipso = NULL;
215 u32 type;
216
217 audit_buf = netlbl_audit_start_common(AUDIT_MAC_MAP_ADD, audit_info);
218 if (audit_buf != NULL) {
219 audit_log_format(audit_buf, " nlbl_domain=%s",
220 entry->domain ? entry->domain : "(default)");
221 if (addr4 != NULL) {
222 struct netlbl_domaddr4_map *map4;
223 map4 = netlbl_domhsh_addr4_entry(addr4);
224 type = map4->def.type;
225 cipsov4 = map4->def.cipso;
226 netlbl_af4list_audit_addr(audit_buf, 0, NULL,
227 addr4->addr, addr4->mask);
228#if IS_ENABLED(CONFIG_IPV6)
229 } else if (addr6 != NULL) {
230 struct netlbl_domaddr6_map *map6;
231 map6 = netlbl_domhsh_addr6_entry(addr6);
232 type = map6->def.type;
233 calipso = map6->def.calipso;
234 netlbl_af6list_audit_addr(audit_buf, 0, NULL,
235 &addr6->addr, &addr6->mask);
236#endif /* IPv6 */
237 } else {
238 type = entry->def.type;
239 cipsov4 = entry->def.cipso;
240 calipso = entry->def.calipso;
241 }
242 switch (type) {
243 case NETLBL_NLTYPE_UNLABELED:
244 audit_log_format(audit_buf, " nlbl_protocol=unlbl");
245 break;
246 case NETLBL_NLTYPE_CIPSOV4:
247 BUG_ON(cipsov4 == NULL);
248 audit_log_format(audit_buf,
249 " nlbl_protocol=cipsov4 cipso_doi=%u",
250 cipsov4->doi);
251 break;
252 case NETLBL_NLTYPE_CALIPSO:
253 BUG_ON(calipso == NULL);
254 audit_log_format(audit_buf,
255 " nlbl_protocol=calipso calipso_doi=%u",
256 calipso->doi);
257 break;
258 }
259 audit_log_format(audit_buf, " res=%u", result == 0 ? 1 : 0);
260 audit_log_end(audit_buf);
261 }
262}
263
264/**
265 * netlbl_domhsh_validate - Validate a new domain mapping entry
266 * @entry: the entry to validate
267 *
268 * This function validates the new domain mapping entry to ensure that it is
269 * a valid entry. Returns zero on success, negative values on failure.
270 *
271 */
272static int netlbl_domhsh_validate(const struct netlbl_dom_map *entry)
273{
274 struct netlbl_af4list *iter4;
275 struct netlbl_domaddr4_map *map4;
276#if IS_ENABLED(CONFIG_IPV6)
277 struct netlbl_af6list *iter6;
278 struct netlbl_domaddr6_map *map6;
279#endif /* IPv6 */
280
281 if (entry == NULL)
282 return -EINVAL;
283
284 if (entry->family != AF_INET && entry->family != AF_INET6 &&
285 (entry->family != AF_UNSPEC ||
286 entry->def.type != NETLBL_NLTYPE_UNLABELED))
287 return -EINVAL;
288
289 switch (entry->def.type) {
290 case NETLBL_NLTYPE_UNLABELED:
291 if (entry->def.cipso != NULL || entry->def.calipso != NULL ||
292 entry->def.addrsel != NULL)
293 return -EINVAL;
294 break;
295 case NETLBL_NLTYPE_CIPSOV4:
296 if (entry->family != AF_INET ||
297 entry->def.cipso == NULL)
298 return -EINVAL;
299 break;
300 case NETLBL_NLTYPE_CALIPSO:
301 if (entry->family != AF_INET6 ||
302 entry->def.calipso == NULL)
303 return -EINVAL;
304 break;
305 case NETLBL_NLTYPE_ADDRSELECT:
306 netlbl_af4list_foreach(iter4, &entry->def.addrsel->list4) {
307 map4 = netlbl_domhsh_addr4_entry(iter4);
308 switch (map4->def.type) {
309 case NETLBL_NLTYPE_UNLABELED:
310 if (map4->def.cipso != NULL)
311 return -EINVAL;
312 break;
313 case NETLBL_NLTYPE_CIPSOV4:
314 if (map4->def.cipso == NULL)
315 return -EINVAL;
316 break;
317 default:
318 return -EINVAL;
319 }
320 }
321#if IS_ENABLED(CONFIG_IPV6)
322 netlbl_af6list_foreach(iter6, &entry->def.addrsel->list6) {
323 map6 = netlbl_domhsh_addr6_entry(iter6);
324 switch (map6->def.type) {
325 case NETLBL_NLTYPE_UNLABELED:
326 if (map6->def.calipso != NULL)
327 return -EINVAL;
328 break;
329 case NETLBL_NLTYPE_CALIPSO:
330 if (map6->def.calipso == NULL)
331 return -EINVAL;
332 break;
333 default:
334 return -EINVAL;
335 }
336 }
337#endif /* IPv6 */
338 break;
339 default:
340 return -EINVAL;
341 }
342
343 return 0;
344}
345
346/*
347 * Domain Hash Table Functions
348 */
349
350/**
351 * netlbl_domhsh_init - Init for the domain hash
352 * @size: the number of bits to use for the hash buckets
353 *
354 * Description:
355 * Initializes the domain hash table, should be called only by
356 * netlbl_user_init() during initialization. Returns zero on success, non-zero
357 * values on error.
358 *
359 */
360int __init netlbl_domhsh_init(u32 size)
361{
362 u32 iter;
363 struct netlbl_domhsh_tbl *hsh_tbl;
364
365 if (size == 0)
366 return -EINVAL;
367
368 hsh_tbl = kmalloc(sizeof(*hsh_tbl), GFP_KERNEL);
369 if (hsh_tbl == NULL)
370 return -ENOMEM;
371 hsh_tbl->size = 1 << size;
372 hsh_tbl->tbl = kcalloc(hsh_tbl->size,
373 sizeof(struct list_head),
374 GFP_KERNEL);
375 if (hsh_tbl->tbl == NULL) {
376 kfree(hsh_tbl);
377 return -ENOMEM;
378 }
379 for (iter = 0; iter < hsh_tbl->size; iter++)
380 INIT_LIST_HEAD(&hsh_tbl->tbl[iter]);
381
382 spin_lock(&netlbl_domhsh_lock);
383 rcu_assign_pointer(netlbl_domhsh, hsh_tbl);
384 spin_unlock(&netlbl_domhsh_lock);
385
386 return 0;
387}
388
389/**
390 * netlbl_domhsh_add - Adds a entry to the domain hash table
391 * @entry: the entry to add
392 * @audit_info: NetLabel audit information
393 *
394 * Description:
395 * Adds a new entry to the domain hash table and handles any updates to the
396 * lower level protocol handler (i.e. CIPSO). @entry->family may be set to
397 * %AF_UNSPEC which will add an entry that matches all address families. This
398 * is only useful for the unlabelled type and will only succeed if there is no
399 * existing entry for any address family with the same domain. Returns zero
400 * on success, negative on failure.
401 *
402 */
403int netlbl_domhsh_add(struct netlbl_dom_map *entry,
404 struct netlbl_audit *audit_info)
405{
406 int ret_val = 0;
407 struct netlbl_dom_map *entry_old, *entry_b;
408 struct netlbl_af4list *iter4;
409 struct netlbl_af4list *tmp4;
410#if IS_ENABLED(CONFIG_IPV6)
411 struct netlbl_af6list *iter6;
412 struct netlbl_af6list *tmp6;
413#endif /* IPv6 */
414
415 ret_val = netlbl_domhsh_validate(entry);
416 if (ret_val != 0)
417 return ret_val;
418
419 /* XXX - we can remove this RCU read lock as the spinlock protects the
420 * entire function, but before we do we need to fixup the
421 * netlbl_af[4,6]list RCU functions to do "the right thing" with
422 * respect to rcu_dereference() when only a spinlock is held. */
423 rcu_read_lock();
424 spin_lock(&netlbl_domhsh_lock);
425 if (entry->domain != NULL)
426 entry_old = netlbl_domhsh_search(entry->domain, entry->family);
427 else
428 entry_old = netlbl_domhsh_search_def(entry->domain,
429 entry->family);
430 if (entry_old == NULL) {
431 entry->valid = 1;
432
433 if (entry->domain != NULL) {
434 u32 bkt = netlbl_domhsh_hash(entry->domain);
435 list_add_tail_rcu(&entry->list,
436 &rcu_dereference(netlbl_domhsh)->tbl[bkt]);
437 } else {
438 INIT_LIST_HEAD(&entry->list);
439 switch (entry->family) {
440 case AF_INET:
441 rcu_assign_pointer(netlbl_domhsh_def_ipv4,
442 entry);
443 break;
444 case AF_INET6:
445 rcu_assign_pointer(netlbl_domhsh_def_ipv6,
446 entry);
447 break;
448 case AF_UNSPEC:
449 if (entry->def.type !=
450 NETLBL_NLTYPE_UNLABELED) {
451 ret_val = -EINVAL;
452 goto add_return;
453 }
454 entry_b = kzalloc(sizeof(*entry_b), GFP_ATOMIC);
455 if (entry_b == NULL) {
456 ret_val = -ENOMEM;
457 goto add_return;
458 }
459 entry_b->family = AF_INET6;
460 entry_b->def.type = NETLBL_NLTYPE_UNLABELED;
461 entry_b->valid = 1;
462 entry->family = AF_INET;
463 rcu_assign_pointer(netlbl_domhsh_def_ipv4,
464 entry);
465 rcu_assign_pointer(netlbl_domhsh_def_ipv6,
466 entry_b);
467 break;
468 default:
469 /* Already checked in
470 * netlbl_domhsh_validate(). */
471 ret_val = -EINVAL;
472 goto add_return;
473 }
474 }
475
476 if (entry->def.type == NETLBL_NLTYPE_ADDRSELECT) {
477 netlbl_af4list_foreach_rcu(iter4,
478 &entry->def.addrsel->list4)
479 netlbl_domhsh_audit_add(entry, iter4, NULL,
480 ret_val, audit_info);
481#if IS_ENABLED(CONFIG_IPV6)
482 netlbl_af6list_foreach_rcu(iter6,
483 &entry->def.addrsel->list6)
484 netlbl_domhsh_audit_add(entry, NULL, iter6,
485 ret_val, audit_info);
486#endif /* IPv6 */
487 } else
488 netlbl_domhsh_audit_add(entry, NULL, NULL,
489 ret_val, audit_info);
490 } else if (entry_old->def.type == NETLBL_NLTYPE_ADDRSELECT &&
491 entry->def.type == NETLBL_NLTYPE_ADDRSELECT) {
492 struct list_head *old_list4;
493 struct list_head *old_list6;
494
495 old_list4 = &entry_old->def.addrsel->list4;
496 old_list6 = &entry_old->def.addrsel->list6;
497
498 /* we only allow the addition of address selectors if all of
499 * the selectors do not exist in the existing domain map */
500 netlbl_af4list_foreach_rcu(iter4, &entry->def.addrsel->list4)
501 if (netlbl_af4list_search_exact(iter4->addr,
502 iter4->mask,
503 old_list4)) {
504 ret_val = -EEXIST;
505 goto add_return;
506 }
507#if IS_ENABLED(CONFIG_IPV6)
508 netlbl_af6list_foreach_rcu(iter6, &entry->def.addrsel->list6)
509 if (netlbl_af6list_search_exact(&iter6->addr,
510 &iter6->mask,
511 old_list6)) {
512 ret_val = -EEXIST;
513 goto add_return;
514 }
515#endif /* IPv6 */
516
517 netlbl_af4list_foreach_safe(iter4, tmp4,
518 &entry->def.addrsel->list4) {
519 netlbl_af4list_remove_entry(iter4);
520 iter4->valid = 1;
521 ret_val = netlbl_af4list_add(iter4, old_list4);
522 netlbl_domhsh_audit_add(entry_old, iter4, NULL,
523 ret_val, audit_info);
524 if (ret_val != 0)
525 goto add_return;
526 }
527#if IS_ENABLED(CONFIG_IPV6)
528 netlbl_af6list_foreach_safe(iter6, tmp6,
529 &entry->def.addrsel->list6) {
530 netlbl_af6list_remove_entry(iter6);
531 iter6->valid = 1;
532 ret_val = netlbl_af6list_add(iter6, old_list6);
533 netlbl_domhsh_audit_add(entry_old, NULL, iter6,
534 ret_val, audit_info);
535 if (ret_val != 0)
536 goto add_return;
537 }
538#endif /* IPv6 */
539 } else
540 ret_val = -EINVAL;
541
542add_return:
543 spin_unlock(&netlbl_domhsh_lock);
544 rcu_read_unlock();
545 return ret_val;
546}
547
548/**
549 * netlbl_domhsh_add_default - Adds the default entry to the domain hash table
550 * @entry: the entry to add
551 * @audit_info: NetLabel audit information
552 *
553 * Description:
554 * Adds a new default entry to the domain hash table and handles any updates
555 * to the lower level protocol handler (i.e. CIPSO). Returns zero on success,
556 * negative on failure.
557 *
558 */
559int netlbl_domhsh_add_default(struct netlbl_dom_map *entry,
560 struct netlbl_audit *audit_info)
561{
562 return netlbl_domhsh_add(entry, audit_info);
563}
564
565/**
566 * netlbl_domhsh_remove_entry - Removes a given entry from the domain table
567 * @entry: the entry to remove
568 * @audit_info: NetLabel audit information
569 *
570 * Description:
571 * Removes an entry from the domain hash table and handles any updates to the
572 * lower level protocol handler (i.e. CIPSO). Caller is responsible for
573 * ensuring that the RCU read lock is held. Returns zero on success, negative
574 * on failure.
575 *
576 */
577int netlbl_domhsh_remove_entry(struct netlbl_dom_map *entry,
578 struct netlbl_audit *audit_info)
579{
580 int ret_val = 0;
581 struct audit_buffer *audit_buf;
582
583 if (entry == NULL)
584 return -ENOENT;
585
586 spin_lock(&netlbl_domhsh_lock);
587 if (entry->valid) {
588 entry->valid = 0;
589 if (entry == rcu_dereference(netlbl_domhsh_def_ipv4))
590 RCU_INIT_POINTER(netlbl_domhsh_def_ipv4, NULL);
591 else if (entry == rcu_dereference(netlbl_domhsh_def_ipv6))
592 RCU_INIT_POINTER(netlbl_domhsh_def_ipv6, NULL);
593 else
594 list_del_rcu(&entry->list);
595 } else
596 ret_val = -ENOENT;
597 spin_unlock(&netlbl_domhsh_lock);
598
599 audit_buf = netlbl_audit_start_common(AUDIT_MAC_MAP_DEL, audit_info);
600 if (audit_buf != NULL) {
601 audit_log_format(audit_buf,
602 " nlbl_domain=%s res=%u",
603 entry->domain ? entry->domain : "(default)",
604 ret_val == 0 ? 1 : 0);
605 audit_log_end(audit_buf);
606 }
607
608 if (ret_val == 0) {
609 struct netlbl_af4list *iter4;
610 struct netlbl_domaddr4_map *map4;
611#if IS_ENABLED(CONFIG_IPV6)
612 struct netlbl_af6list *iter6;
613 struct netlbl_domaddr6_map *map6;
614#endif /* IPv6 */
615
616 switch (entry->def.type) {
617 case NETLBL_NLTYPE_ADDRSELECT:
618 netlbl_af4list_foreach_rcu(iter4,
619 &entry->def.addrsel->list4) {
620 map4 = netlbl_domhsh_addr4_entry(iter4);
621 cipso_v4_doi_putdef(map4->def.cipso);
622 }
623#if IS_ENABLED(CONFIG_IPV6)
624 netlbl_af6list_foreach_rcu(iter6,
625 &entry->def.addrsel->list6) {
626 map6 = netlbl_domhsh_addr6_entry(iter6);
627 calipso_doi_putdef(map6->def.calipso);
628 }
629#endif /* IPv6 */
630 break;
631 case NETLBL_NLTYPE_CIPSOV4:
632 cipso_v4_doi_putdef(entry->def.cipso);
633 break;
634#if IS_ENABLED(CONFIG_IPV6)
635 case NETLBL_NLTYPE_CALIPSO:
636 calipso_doi_putdef(entry->def.calipso);
637 break;
638#endif /* IPv6 */
639 }
640 call_rcu(&entry->rcu, netlbl_domhsh_free_entry);
641 }
642
643 return ret_val;
644}
645
646/**
647 * netlbl_domhsh_remove_af4 - Removes an address selector entry
648 * @domain: the domain
649 * @addr: IPv4 address
650 * @mask: IPv4 address mask
651 * @audit_info: NetLabel audit information
652 *
653 * Description:
654 * Removes an individual address selector from a domain mapping and potentially
655 * the entire mapping if it is empty. Returns zero on success, negative values
656 * on failure.
657 *
658 */
659int netlbl_domhsh_remove_af4(const char *domain,
660 const struct in_addr *addr,
661 const struct in_addr *mask,
662 struct netlbl_audit *audit_info)
663{
664 struct netlbl_dom_map *entry_map;
665 struct netlbl_af4list *entry_addr;
666 struct netlbl_af4list *iter4;
667#if IS_ENABLED(CONFIG_IPV6)
668 struct netlbl_af6list *iter6;
669#endif /* IPv6 */
670 struct netlbl_domaddr4_map *entry;
671
672 rcu_read_lock();
673
674 if (domain)
675 entry_map = netlbl_domhsh_search(domain, AF_INET);
676 else
677 entry_map = netlbl_domhsh_search_def(domain, AF_INET);
678 if (entry_map == NULL ||
679 entry_map->def.type != NETLBL_NLTYPE_ADDRSELECT)
680 goto remove_af4_failure;
681
682 spin_lock(&netlbl_domhsh_lock);
683 entry_addr = netlbl_af4list_remove(addr->s_addr, mask->s_addr,
684 &entry_map->def.addrsel->list4);
685 spin_unlock(&netlbl_domhsh_lock);
686
687 if (entry_addr == NULL)
688 goto remove_af4_failure;
689 netlbl_af4list_foreach_rcu(iter4, &entry_map->def.addrsel->list4)
690 goto remove_af4_single_addr;
691#if IS_ENABLED(CONFIG_IPV6)
692 netlbl_af6list_foreach_rcu(iter6, &entry_map->def.addrsel->list6)
693 goto remove_af4_single_addr;
694#endif /* IPv6 */
695 /* the domain mapping is empty so remove it from the mapping table */
696 netlbl_domhsh_remove_entry(entry_map, audit_info);
697
698remove_af4_single_addr:
699 rcu_read_unlock();
700 /* yick, we can't use call_rcu here because we don't have a rcu head
701 * pointer but hopefully this should be a rare case so the pause
702 * shouldn't be a problem */
703 synchronize_rcu();
704 entry = netlbl_domhsh_addr4_entry(entry_addr);
705 cipso_v4_doi_putdef(entry->def.cipso);
706 kfree(entry);
707 return 0;
708
709remove_af4_failure:
710 rcu_read_unlock();
711 return -ENOENT;
712}
713
714#if IS_ENABLED(CONFIG_IPV6)
715/**
716 * netlbl_domhsh_remove_af6 - Removes an address selector entry
717 * @domain: the domain
718 * @addr: IPv6 address
719 * @mask: IPv6 address mask
720 * @audit_info: NetLabel audit information
721 *
722 * Description:
723 * Removes an individual address selector from a domain mapping and potentially
724 * the entire mapping if it is empty. Returns zero on success, negative values
725 * on failure.
726 *
727 */
728int netlbl_domhsh_remove_af6(const char *domain,
729 const struct in6_addr *addr,
730 const struct in6_addr *mask,
731 struct netlbl_audit *audit_info)
732{
733 struct netlbl_dom_map *entry_map;
734 struct netlbl_af6list *entry_addr;
735 struct netlbl_af4list *iter4;
736 struct netlbl_af6list *iter6;
737 struct netlbl_domaddr6_map *entry;
738
739 rcu_read_lock();
740
741 if (domain)
742 entry_map = netlbl_domhsh_search(domain, AF_INET6);
743 else
744 entry_map = netlbl_domhsh_search_def(domain, AF_INET6);
745 if (entry_map == NULL ||
746 entry_map->def.type != NETLBL_NLTYPE_ADDRSELECT)
747 goto remove_af6_failure;
748
749 spin_lock(&netlbl_domhsh_lock);
750 entry_addr = netlbl_af6list_remove(addr, mask,
751 &entry_map->def.addrsel->list6);
752 spin_unlock(&netlbl_domhsh_lock);
753
754 if (entry_addr == NULL)
755 goto remove_af6_failure;
756 netlbl_af4list_foreach_rcu(iter4, &entry_map->def.addrsel->list4)
757 goto remove_af6_single_addr;
758 netlbl_af6list_foreach_rcu(iter6, &entry_map->def.addrsel->list6)
759 goto remove_af6_single_addr;
760 /* the domain mapping is empty so remove it from the mapping table */
761 netlbl_domhsh_remove_entry(entry_map, audit_info);
762
763remove_af6_single_addr:
764 rcu_read_unlock();
765 /* yick, we can't use call_rcu here because we don't have a rcu head
766 * pointer but hopefully this should be a rare case so the pause
767 * shouldn't be a problem */
768 synchronize_rcu();
769 entry = netlbl_domhsh_addr6_entry(entry_addr);
770 calipso_doi_putdef(entry->def.calipso);
771 kfree(entry);
772 return 0;
773
774remove_af6_failure:
775 rcu_read_unlock();
776 return -ENOENT;
777}
778#endif /* IPv6 */
779
780/**
781 * netlbl_domhsh_remove - Removes an entry from the domain hash table
782 * @domain: the domain to remove
783 * @family: address family
784 * @audit_info: NetLabel audit information
785 *
786 * Description:
787 * Removes an entry from the domain hash table and handles any updates to the
788 * lower level protocol handler (i.e. CIPSO). @family may be %AF_UNSPEC which
789 * removes all address family entries. Returns zero on success, negative on
790 * failure.
791 *
792 */
793int netlbl_domhsh_remove(const char *domain, u16 family,
794 struct netlbl_audit *audit_info)
795{
796 int ret_val = -EINVAL;
797 struct netlbl_dom_map *entry;
798
799 rcu_read_lock();
800
801 if (family == AF_INET || family == AF_UNSPEC) {
802 if (domain)
803 entry = netlbl_domhsh_search(domain, AF_INET);
804 else
805 entry = netlbl_domhsh_search_def(domain, AF_INET);
806 ret_val = netlbl_domhsh_remove_entry(entry, audit_info);
807 if (ret_val && ret_val != -ENOENT)
808 goto done;
809 }
810 if (family == AF_INET6 || family == AF_UNSPEC) {
811 int ret_val2;
812
813 if (domain)
814 entry = netlbl_domhsh_search(domain, AF_INET6);
815 else
816 entry = netlbl_domhsh_search_def(domain, AF_INET6);
817 ret_val2 = netlbl_domhsh_remove_entry(entry, audit_info);
818 if (ret_val2 != -ENOENT)
819 ret_val = ret_val2;
820 }
821done:
822 rcu_read_unlock();
823
824 return ret_val;
825}
826
827/**
828 * netlbl_domhsh_remove_default - Removes the default entry from the table
829 * @family: address family
830 * @audit_info: NetLabel audit information
831 *
832 * Description:
833 * Removes/resets the default entry corresponding to @family from the domain
834 * hash table and handles any updates to the lower level protocol handler
835 * (i.e. CIPSO). @family may be %AF_UNSPEC which removes all address family
836 * entries. Returns zero on success, negative on failure.
837 *
838 */
839int netlbl_domhsh_remove_default(u16 family, struct netlbl_audit *audit_info)
840{
841 return netlbl_domhsh_remove(NULL, family, audit_info);
842}
843
844/**
845 * netlbl_domhsh_getentry - Get an entry from the domain hash table
846 * @domain: the domain name to search for
847 * @family: address family
848 *
849 * Description:
850 * Look through the domain hash table searching for an entry to match @domain,
851 * with address family @family, return a pointer to a copy of the entry or
852 * NULL. The caller is responsible for ensuring that rcu_read_[un]lock() is
853 * called.
854 *
855 */
856struct netlbl_dom_map *netlbl_domhsh_getentry(const char *domain, u16 family)
857{
858 if (family == AF_UNSPEC)
859 return NULL;
860 return netlbl_domhsh_search_def(domain, family);
861}
862
863/**
864 * netlbl_domhsh_getentry_af4 - Get an entry from the domain hash table
865 * @domain: the domain name to search for
866 * @addr: the IP address to search for
867 *
868 * Description:
869 * Look through the domain hash table searching for an entry to match @domain
870 * and @addr, return a pointer to a copy of the entry or NULL. The caller is
871 * responsible for ensuring that rcu_read_[un]lock() is called.
872 *
873 */
874struct netlbl_dommap_def *netlbl_domhsh_getentry_af4(const char *domain,
875 __be32 addr)
876{
877 struct netlbl_dom_map *dom_iter;
878 struct netlbl_af4list *addr_iter;
879
880 dom_iter = netlbl_domhsh_search_def(domain, AF_INET);
881 if (dom_iter == NULL)
882 return NULL;
883
884 if (dom_iter->def.type != NETLBL_NLTYPE_ADDRSELECT)
885 return &dom_iter->def;
886 addr_iter = netlbl_af4list_search(addr, &dom_iter->def.addrsel->list4);
887 if (addr_iter == NULL)
888 return NULL;
889 return &(netlbl_domhsh_addr4_entry(addr_iter)->def);
890}
891
892#if IS_ENABLED(CONFIG_IPV6)
893/**
894 * netlbl_domhsh_getentry_af6 - Get an entry from the domain hash table
895 * @domain: the domain name to search for
896 * @addr: the IP address to search for
897 *
898 * Description:
899 * Look through the domain hash table searching for an entry to match @domain
900 * and @addr, return a pointer to a copy of the entry or NULL. The caller is
901 * responsible for ensuring that rcu_read_[un]lock() is called.
902 *
903 */
904struct netlbl_dommap_def *netlbl_domhsh_getentry_af6(const char *domain,
905 const struct in6_addr *addr)
906{
907 struct netlbl_dom_map *dom_iter;
908 struct netlbl_af6list *addr_iter;
909
910 dom_iter = netlbl_domhsh_search_def(domain, AF_INET6);
911 if (dom_iter == NULL)
912 return NULL;
913
914 if (dom_iter->def.type != NETLBL_NLTYPE_ADDRSELECT)
915 return &dom_iter->def;
916 addr_iter = netlbl_af6list_search(addr, &dom_iter->def.addrsel->list6);
917 if (addr_iter == NULL)
918 return NULL;
919 return &(netlbl_domhsh_addr6_entry(addr_iter)->def);
920}
921#endif /* IPv6 */
922
923/**
924 * netlbl_domhsh_walk - Iterate through the domain mapping hash table
925 * @skip_bkt: the number of buckets to skip at the start
926 * @skip_chain: the number of entries to skip in the first iterated bucket
927 * @callback: callback for each entry
928 * @cb_arg: argument for the callback function
929 *
930 * Description:
931 * Interate over the domain mapping hash table, skipping the first @skip_bkt
932 * buckets and @skip_chain entries. For each entry in the table call
933 * @callback, if @callback returns a negative value stop 'walking' through the
934 * table and return. Updates the values in @skip_bkt and @skip_chain on
935 * return. Returns zero on success, negative values on failure.
936 *
937 */
938int netlbl_domhsh_walk(u32 *skip_bkt,
939 u32 *skip_chain,
940 int (*callback) (struct netlbl_dom_map *entry, void *arg),
941 void *cb_arg)
942{
943 int ret_val = -ENOENT;
944 u32 iter_bkt;
945 struct list_head *iter_list;
946 struct netlbl_dom_map *iter_entry;
947 u32 chain_cnt = 0;
948
949 rcu_read_lock();
950 for (iter_bkt = *skip_bkt;
951 iter_bkt < rcu_dereference(netlbl_domhsh)->size;
952 iter_bkt++, chain_cnt = 0) {
953 iter_list = &rcu_dereference(netlbl_domhsh)->tbl[iter_bkt];
954 list_for_each_entry_rcu(iter_entry, iter_list, list)
955 if (iter_entry->valid) {
956 if (chain_cnt++ < *skip_chain)
957 continue;
958 ret_val = callback(iter_entry, cb_arg);
959 if (ret_val < 0) {
960 chain_cnt--;
961 goto walk_return;
962 }
963 }
964 }
965
966walk_return:
967 rcu_read_unlock();
968 *skip_bkt = iter_bkt;
969 *skip_chain = chain_cnt;
970 return ret_val;
971}