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 
35 struct 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 */
43 static DEFINE_SPINLOCK(netlbl_domhsh_lock);
44 #define netlbl_domhsh_rcu_deref(p) \
45 	rcu_dereference_check(p, lockdep_is_held(&netlbl_domhsh_lock))
46 static struct netlbl_domhsh_tbl __rcu *netlbl_domhsh;
47 static struct netlbl_dom_map __rcu *netlbl_domhsh_def_ipv4;
48 static 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  */
64 static 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  */
105 static 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 
119 static 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  */
137 static 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  */
172 static 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  */
208 static 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  */
274 static 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  */
362 int __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  */
405 int 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 
546 add_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  */
563 int 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  */
581 int 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  */
660 int 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 
699 remove_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 
710 remove_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  */
729 int 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 
764 remove_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 
775 remove_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  */
794 int 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 	}
822 done:
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  */
840 int 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  */
857 struct 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  */
875 struct 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  */
905 struct 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  * Interate 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  */
939 int 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 
967 walk_return:
968 	rcu_read_unlock();
969 	*skip_bkt = iter_bkt;
970 	*skip_chain = chain_cnt;
971 	return ret_val;
972 }
973