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(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(entry: iter6);
85 kfree(netlbl_domhsh_addr6_entry(iter6));
86 }
87#endif /* IPv6 */
88 kfree(objp: ptr->def.addrsel);
89 }
90 kfree(objp: ptr->domain);
91 kfree(objp: 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(key: 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(f1: iter->family, f2: 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(ab: audit_buf, fmt: " 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, src: 0, NULL,
229 addr: addr4->addr, mask: 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, src: 0, NULL,
237 addr: &addr6->addr, mask: &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(ab: audit_buf, fmt: " nlbl_protocol=unlbl");
247 break;
248 case NETLBL_NLTYPE_CIPSOV4:
249 BUG_ON(cipsov4 == NULL);
250 audit_log_format(ab: audit_buf,
251 fmt: " 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(ab: audit_buf,
257 fmt: " nlbl_protocol=calipso calipso_doi=%u",
258 calipso->doi);
259 break;
260 }
261 audit_log_format(ab: audit_buf, fmt: " res=%u", result == 0 ? 1 : 0);
262 audit_log_end(ab: 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(objp: hsh_tbl);
379 return -ENOMEM;
380 }
381 for (iter = 0; iter < hsh_tbl->size; iter++)
382 INIT_LIST_HEAD(list: &hsh_tbl->tbl[iter]);
383
384 spin_lock(lock: &netlbl_domhsh_lock);
385 rcu_assign_pointer(netlbl_domhsh, hsh_tbl);
386 spin_unlock(lock: &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(lock: &netlbl_domhsh_lock);
427 if (entry->domain != NULL)
428 entry_old = netlbl_domhsh_search(domain: entry->domain, family: entry->family);
429 else
430 entry_old = netlbl_domhsh_search_def(domain: entry->domain,
431 family: entry->family);
432 if (entry_old == NULL) {
433 entry->valid = 1;
434
435 if (entry->domain != NULL) {
436 u32 bkt = netlbl_domhsh_hash(key: entry->domain);
437 list_add_tail_rcu(new: &entry->list,
438 head: &rcu_dereference(netlbl_domhsh)->tbl[bkt]);
439 } else {
440 INIT_LIST_HEAD(list: &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, addr4: iter4, NULL,
482 result: 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, addr6: iter6,
487 result: ret_val, audit_info);
488#endif /* IPv6 */
489 } else
490 netlbl_domhsh_audit_add(entry, NULL, NULL,
491 result: 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(addr: iter4->addr,
504 mask: iter4->mask,
505 head: 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(addr: &iter6->addr,
512 mask: &iter6->mask,
513 head: 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(entry: iter4);
522 iter4->valid = 1;
523 ret_val = netlbl_af4list_add(entry: iter4, head: old_list4);
524 netlbl_domhsh_audit_add(entry: entry_old, addr4: iter4, NULL,
525 result: 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(entry: iter6);
533 iter6->valid = 1;
534 ret_val = netlbl_af6list_add(entry: iter6, head: old_list6);
535 netlbl_domhsh_audit_add(entry: entry_old, NULL, addr6: iter6,
536 result: 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: &entry->rcu);
543 } else
544 ret_val = -EINVAL;
545
546add_return:
547 spin_unlock(lock: &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(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: &entry->list);
605 } else
606 ret_val = -ENOENT;
607 spin_unlock(lock: &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(ab: audit_buf,
615 fmt: " nlbl_domain=%s res=1",
616 entry->domain ? entry->domain : "(default)");
617 audit_log_end(ab: 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(doi_def: 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(doi_def: map6->def.calipso);
630 }
631#endif /* IPv6 */
632 break;
633 case NETLBL_NLTYPE_CIPSOV4:
634 cipso_v4_doi_putdef(doi_def: entry->def.cipso);
635 break;
636#if IS_ENABLED(CONFIG_IPV6)
637 case NETLBL_NLTYPE_CALIPSO:
638 calipso_doi_putdef(doi_def: entry->def.calipso);
639 break;
640#endif /* IPv6 */
641 }
642 call_rcu(head: &entry->rcu, func: 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(lock: &netlbl_domhsh_lock);
684 entry_addr = netlbl_af4list_remove(addr: addr->s_addr, mask: mask->s_addr,
685 head: &entry_map->def.addrsel->list4);
686 spin_unlock(lock: &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: 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(doi_def: entry->def.cipso);
707 kfree(objp: 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(lock: &netlbl_domhsh_lock);
751 entry_addr = netlbl_af6list_remove(addr, mask,
752 head: &entry_map->def.addrsel->list6);
753 spin_unlock(lock: &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: 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(doi_def: entry->def.calipso);
772 kfree(objp: 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, head: &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, head: &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}
973