xref: /linux/net/netlabel/netlabel_domainhash.c (revision bf4afc53b77aeaa48b5409da5c8da6bb4eff7f43)
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  */
netlbl_domhsh_free_entry(struct rcu_head * entry)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  */
netlbl_domhsh_hash(const char * key)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 
netlbl_family_match(u16 f1,u16 f2)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  */
netlbl_domhsh_search(const char * domain,u16 family)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  */
netlbl_domhsh_search_def(const char * domain,u16 family)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  */
netlbl_domhsh_audit_add(struct netlbl_dom_map * entry,struct netlbl_af4list * addr4,struct netlbl_af6list * addr6,int result,struct netlbl_audit * audit_info)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  */
netlbl_domhsh_validate(const struct netlbl_dom_map * entry)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  */
netlbl_domhsh_init(u32 size)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_obj(*hsh_tbl);
371 	if (hsh_tbl == NULL)
372 		return -ENOMEM;
373 	hsh_tbl->size = 1 << size;
374 	hsh_tbl->tbl = kzalloc_objs(struct list_head, hsh_tbl->size);
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  */
netlbl_domhsh_add(struct netlbl_dom_map * entry,struct netlbl_audit * audit_info)403 int 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_obj(*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 		/* cleanup the new entry since we've moved everything over */
540 		netlbl_domhsh_free_entry(&entry->rcu);
541 	} else
542 		ret_val = -EINVAL;
543 
544 add_return:
545 	spin_unlock(&netlbl_domhsh_lock);
546 	rcu_read_unlock();
547 	return ret_val;
548 }
549 
550 /**
551  * netlbl_domhsh_add_default - Adds the default entry to the domain hash table
552  * @entry: the entry to add
553  * @audit_info: NetLabel audit information
554  *
555  * Description:
556  * Adds a new default entry to the domain hash table and handles any updates
557  * to the lower level protocol handler (i.e. CIPSO).  Returns zero on success,
558  * negative on failure.
559  *
560  */
netlbl_domhsh_add_default(struct netlbl_dom_map * entry,struct netlbl_audit * audit_info)561 int netlbl_domhsh_add_default(struct netlbl_dom_map *entry,
562 			      struct netlbl_audit *audit_info)
563 {
564 	return netlbl_domhsh_add(entry, audit_info);
565 }
566 
567 /**
568  * netlbl_domhsh_remove_entry - Removes a given entry from the domain table
569  * @entry: the entry to remove
570  * @audit_info: NetLabel audit information
571  *
572  * Description:
573  * Removes an entry from the domain hash table and handles any updates to the
574  * lower level protocol handler (i.e. CIPSO).  Caller is responsible for
575  * ensuring that the RCU read lock is held.  Returns zero on success, negative
576  * on failure.
577  *
578  */
netlbl_domhsh_remove_entry(struct netlbl_dom_map * entry,struct netlbl_audit * audit_info)579 int netlbl_domhsh_remove_entry(struct netlbl_dom_map *entry,
580 			       struct netlbl_audit *audit_info)
581 {
582 	int ret_val = 0;
583 	struct audit_buffer *audit_buf;
584 	struct netlbl_af4list *iter4;
585 	struct netlbl_domaddr4_map *map4;
586 #if IS_ENABLED(CONFIG_IPV6)
587 	struct netlbl_af6list *iter6;
588 	struct netlbl_domaddr6_map *map6;
589 #endif /* IPv6 */
590 
591 	if (entry == NULL)
592 		return -ENOENT;
593 
594 	spin_lock(&netlbl_domhsh_lock);
595 	if (entry->valid) {
596 		entry->valid = 0;
597 		if (entry == rcu_dereference(netlbl_domhsh_def_ipv4))
598 			RCU_INIT_POINTER(netlbl_domhsh_def_ipv4, NULL);
599 		else if (entry == rcu_dereference(netlbl_domhsh_def_ipv6))
600 			RCU_INIT_POINTER(netlbl_domhsh_def_ipv6, NULL);
601 		else
602 			list_del_rcu(&entry->list);
603 	} else
604 		ret_val = -ENOENT;
605 	spin_unlock(&netlbl_domhsh_lock);
606 
607 	if (ret_val)
608 		return ret_val;
609 
610 	audit_buf = netlbl_audit_start_common(AUDIT_MAC_MAP_DEL, audit_info);
611 	if (audit_buf != NULL) {
612 		audit_log_format(audit_buf,
613 				 " nlbl_domain=%s res=1",
614 				 entry->domain ? entry->domain : "(default)");
615 		audit_log_end(audit_buf);
616 	}
617 
618 	switch (entry->def.type) {
619 	case NETLBL_NLTYPE_ADDRSELECT:
620 		netlbl_af4list_foreach_rcu(iter4, &entry->def.addrsel->list4) {
621 			map4 = netlbl_domhsh_addr4_entry(iter4);
622 			cipso_v4_doi_putdef(map4->def.cipso);
623 		}
624 #if IS_ENABLED(CONFIG_IPV6)
625 		netlbl_af6list_foreach_rcu(iter6, &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 	return ret_val;
643 }
644 
645 /**
646  * netlbl_domhsh_remove_af4 - Removes an address selector entry
647  * @domain: the domain
648  * @addr: IPv4 address
649  * @mask: IPv4 address mask
650  * @audit_info: NetLabel audit information
651  *
652  * Description:
653  * Removes an individual address selector from a domain mapping and potentially
654  * the entire mapping if it is empty.  Returns zero on success, negative values
655  * on failure.
656  *
657  */
netlbl_domhsh_remove_af4(const char * domain,const struct in_addr * addr,const struct in_addr * mask,struct netlbl_audit * audit_info)658 int netlbl_domhsh_remove_af4(const char *domain,
659 			     const struct in_addr *addr,
660 			     const struct in_addr *mask,
661 			     struct netlbl_audit *audit_info)
662 {
663 	struct netlbl_dom_map *entry_map;
664 	struct netlbl_af4list *entry_addr;
665 	struct netlbl_af4list *iter4;
666 #if IS_ENABLED(CONFIG_IPV6)
667 	struct netlbl_af6list *iter6;
668 #endif /* IPv6 */
669 	struct netlbl_domaddr4_map *entry;
670 
671 	rcu_read_lock();
672 
673 	if (domain)
674 		entry_map = netlbl_domhsh_search(domain, AF_INET);
675 	else
676 		entry_map = netlbl_domhsh_search_def(domain, AF_INET);
677 	if (entry_map == NULL ||
678 	    entry_map->def.type != NETLBL_NLTYPE_ADDRSELECT)
679 		goto remove_af4_failure;
680 
681 	spin_lock(&netlbl_domhsh_lock);
682 	entry_addr = netlbl_af4list_remove(addr->s_addr, mask->s_addr,
683 					   &entry_map->def.addrsel->list4);
684 	spin_unlock(&netlbl_domhsh_lock);
685 
686 	if (entry_addr == NULL)
687 		goto remove_af4_failure;
688 	netlbl_af4list_foreach_rcu(iter4, &entry_map->def.addrsel->list4)
689 		goto remove_af4_single_addr;
690 #if IS_ENABLED(CONFIG_IPV6)
691 	netlbl_af6list_foreach_rcu(iter6, &entry_map->def.addrsel->list6)
692 		goto remove_af4_single_addr;
693 #endif /* IPv6 */
694 	/* the domain mapping is empty so remove it from the mapping table */
695 	netlbl_domhsh_remove_entry(entry_map, audit_info);
696 
697 remove_af4_single_addr:
698 	rcu_read_unlock();
699 	/* yick, we can't use call_rcu here because we don't have a rcu head
700 	 * pointer but hopefully this should be a rare case so the pause
701 	 * shouldn't be a problem */
702 	synchronize_rcu();
703 	entry = netlbl_domhsh_addr4_entry(entry_addr);
704 	cipso_v4_doi_putdef(entry->def.cipso);
705 	kfree(entry);
706 	return 0;
707 
708 remove_af4_failure:
709 	rcu_read_unlock();
710 	return -ENOENT;
711 }
712 
713 #if IS_ENABLED(CONFIG_IPV6)
714 /**
715  * netlbl_domhsh_remove_af6 - Removes an address selector entry
716  * @domain: the domain
717  * @addr: IPv6 address
718  * @mask: IPv6 address mask
719  * @audit_info: NetLabel audit information
720  *
721  * Description:
722  * Removes an individual address selector from a domain mapping and potentially
723  * the entire mapping if it is empty.  Returns zero on success, negative values
724  * on failure.
725  *
726  */
netlbl_domhsh_remove_af6(const char * domain,const struct in6_addr * addr,const struct in6_addr * mask,struct netlbl_audit * audit_info)727 int netlbl_domhsh_remove_af6(const char *domain,
728 			     const struct in6_addr *addr,
729 			     const struct in6_addr *mask,
730 			     struct netlbl_audit *audit_info)
731 {
732 	struct netlbl_dom_map *entry_map;
733 	struct netlbl_af6list *entry_addr;
734 	struct netlbl_af4list *iter4;
735 	struct netlbl_af6list *iter6;
736 	struct netlbl_domaddr6_map *entry;
737 
738 	rcu_read_lock();
739 
740 	if (domain)
741 		entry_map = netlbl_domhsh_search(domain, AF_INET6);
742 	else
743 		entry_map = netlbl_domhsh_search_def(domain, AF_INET6);
744 	if (entry_map == NULL ||
745 	    entry_map->def.type != NETLBL_NLTYPE_ADDRSELECT)
746 		goto remove_af6_failure;
747 
748 	spin_lock(&netlbl_domhsh_lock);
749 	entry_addr = netlbl_af6list_remove(addr, mask,
750 					   &entry_map->def.addrsel->list6);
751 	spin_unlock(&netlbl_domhsh_lock);
752 
753 	if (entry_addr == NULL)
754 		goto remove_af6_failure;
755 	netlbl_af4list_foreach_rcu(iter4, &entry_map->def.addrsel->list4)
756 		goto remove_af6_single_addr;
757 	netlbl_af6list_foreach_rcu(iter6, &entry_map->def.addrsel->list6)
758 		goto remove_af6_single_addr;
759 	/* the domain mapping is empty so remove it from the mapping table */
760 	netlbl_domhsh_remove_entry(entry_map, audit_info);
761 
762 remove_af6_single_addr:
763 	rcu_read_unlock();
764 	/* yick, we can't use call_rcu here because we don't have a rcu head
765 	 * pointer but hopefully this should be a rare case so the pause
766 	 * shouldn't be a problem */
767 	synchronize_rcu();
768 	entry = netlbl_domhsh_addr6_entry(entry_addr);
769 	calipso_doi_putdef(entry->def.calipso);
770 	kfree(entry);
771 	return 0;
772 
773 remove_af6_failure:
774 	rcu_read_unlock();
775 	return -ENOENT;
776 }
777 #endif /* IPv6 */
778 
779 /**
780  * netlbl_domhsh_remove - Removes an entry from the domain hash table
781  * @domain: the domain to remove
782  * @family: address family
783  * @audit_info: NetLabel audit information
784  *
785  * Description:
786  * Removes an entry from the domain hash table and handles any updates to the
787  * lower level protocol handler (i.e. CIPSO).  @family may be %AF_UNSPEC which
788  * removes all address family entries.  Returns zero on success, negative on
789  * failure.
790  *
791  */
netlbl_domhsh_remove(const char * domain,u16 family,struct netlbl_audit * audit_info)792 int netlbl_domhsh_remove(const char *domain, u16 family,
793 			 struct netlbl_audit *audit_info)
794 {
795 	int ret_val = -EINVAL;
796 	struct netlbl_dom_map *entry;
797 
798 	rcu_read_lock();
799 
800 	if (family == AF_INET || family == AF_UNSPEC) {
801 		if (domain)
802 			entry = netlbl_domhsh_search(domain, AF_INET);
803 		else
804 			entry = netlbl_domhsh_search_def(domain, AF_INET);
805 		ret_val = netlbl_domhsh_remove_entry(entry, audit_info);
806 		if (ret_val && ret_val != -ENOENT)
807 			goto done;
808 	}
809 	if (family == AF_INET6 || family == AF_UNSPEC) {
810 		int ret_val2;
811 
812 		if (domain)
813 			entry = netlbl_domhsh_search(domain, AF_INET6);
814 		else
815 			entry = netlbl_domhsh_search_def(domain, AF_INET6);
816 		ret_val2 = netlbl_domhsh_remove_entry(entry, audit_info);
817 		if (ret_val2 != -ENOENT)
818 			ret_val = ret_val2;
819 	}
820 done:
821 	rcu_read_unlock();
822 
823 	return ret_val;
824 }
825 
826 /**
827  * netlbl_domhsh_remove_default - Removes the default entry from the table
828  * @family: address family
829  * @audit_info: NetLabel audit information
830  *
831  * Description:
832  * Removes/resets the default entry corresponding to @family from the domain
833  * hash table and handles any updates to the lower level protocol handler
834  * (i.e. CIPSO).  @family may be %AF_UNSPEC which removes all address family
835  * entries.  Returns zero on success, negative on failure.
836  *
837  */
netlbl_domhsh_remove_default(u16 family,struct netlbl_audit * audit_info)838 int netlbl_domhsh_remove_default(u16 family, struct netlbl_audit *audit_info)
839 {
840 	return netlbl_domhsh_remove(NULL, family, audit_info);
841 }
842 
843 /**
844  * netlbl_domhsh_getentry - Get an entry from the domain hash table
845  * @domain: the domain name to search for
846  * @family: address family
847  *
848  * Description:
849  * Look through the domain hash table searching for an entry to match @domain,
850  * with address family @family, return a pointer to a copy of the entry or
851  * NULL.  The caller is responsible for ensuring that rcu_read_[un]lock() is
852  * called.
853  *
854  */
netlbl_domhsh_getentry(const char * domain,u16 family)855 struct netlbl_dom_map *netlbl_domhsh_getentry(const char *domain, u16 family)
856 {
857 	if (family == AF_UNSPEC)
858 		return NULL;
859 	return netlbl_domhsh_search_def(domain, family);
860 }
861 
862 /**
863  * netlbl_domhsh_getentry_af4 - Get an entry from the domain hash table
864  * @domain: the domain name to search for
865  * @addr: the IP address to search for
866  *
867  * Description:
868  * Look through the domain hash table searching for an entry to match @domain
869  * and @addr, return a pointer to a copy of the entry or NULL.  The caller is
870  * responsible for ensuring that rcu_read_[un]lock() is called.
871  *
872  */
netlbl_domhsh_getentry_af4(const char * domain,__be32 addr)873 struct netlbl_dommap_def *netlbl_domhsh_getentry_af4(const char *domain,
874 						     __be32 addr)
875 {
876 	struct netlbl_dom_map *dom_iter;
877 	struct netlbl_af4list *addr_iter;
878 
879 	dom_iter = netlbl_domhsh_search_def(domain, AF_INET);
880 	if (dom_iter == NULL)
881 		return NULL;
882 
883 	if (dom_iter->def.type != NETLBL_NLTYPE_ADDRSELECT)
884 		return &dom_iter->def;
885 	addr_iter = netlbl_af4list_search(addr, &dom_iter->def.addrsel->list4);
886 	if (addr_iter == NULL)
887 		return NULL;
888 	return &(netlbl_domhsh_addr4_entry(addr_iter)->def);
889 }
890 
891 #if IS_ENABLED(CONFIG_IPV6)
892 /**
893  * netlbl_domhsh_getentry_af6 - Get an entry from the domain hash table
894  * @domain: the domain name to search for
895  * @addr: the IP address to search for
896  *
897  * Description:
898  * Look through the domain hash table searching for an entry to match @domain
899  * and @addr, return a pointer to a copy of the entry or NULL.  The caller is
900  * responsible for ensuring that rcu_read_[un]lock() is called.
901  *
902  */
netlbl_domhsh_getentry_af6(const char * domain,const struct in6_addr * addr)903 struct netlbl_dommap_def *netlbl_domhsh_getentry_af6(const char *domain,
904 						   const struct in6_addr *addr)
905 {
906 	struct netlbl_dom_map *dom_iter;
907 	struct netlbl_af6list *addr_iter;
908 
909 	dom_iter = netlbl_domhsh_search_def(domain, AF_INET6);
910 	if (dom_iter == NULL)
911 		return NULL;
912 
913 	if (dom_iter->def.type != NETLBL_NLTYPE_ADDRSELECT)
914 		return &dom_iter->def;
915 	addr_iter = netlbl_af6list_search(addr, &dom_iter->def.addrsel->list6);
916 	if (addr_iter == NULL)
917 		return NULL;
918 	return &(netlbl_domhsh_addr6_entry(addr_iter)->def);
919 }
920 #endif /* IPv6 */
921 
922 /**
923  * netlbl_domhsh_walk - Iterate through the domain mapping hash table
924  * @skip_bkt: the number of buckets to skip at the start
925  * @skip_chain: the number of entries to skip in the first iterated bucket
926  * @callback: callback for each entry
927  * @cb_arg: argument for the callback function
928  *
929  * Description:
930  * Iterate over the domain mapping hash table, skipping the first @skip_bkt
931  * buckets and @skip_chain entries.  For each entry in the table call
932  * @callback, if @callback returns a negative value stop 'walking' through the
933  * table and return.  Updates the values in @skip_bkt and @skip_chain on
934  * return.  Returns zero on success, negative values on failure.
935  *
936  */
netlbl_domhsh_walk(u32 * skip_bkt,u32 * skip_chain,int (* callback)(struct netlbl_dom_map * entry,void * arg),void * cb_arg)937 int netlbl_domhsh_walk(u32 *skip_bkt,
938 		     u32 *skip_chain,
939 		     int (*callback) (struct netlbl_dom_map *entry, void *arg),
940 		     void *cb_arg)
941 {
942 	int ret_val = -ENOENT;
943 	u32 iter_bkt;
944 	struct list_head *iter_list;
945 	struct netlbl_dom_map *iter_entry;
946 	u32 chain_cnt = 0;
947 
948 	rcu_read_lock();
949 	for (iter_bkt = *skip_bkt;
950 	     iter_bkt < rcu_dereference(netlbl_domhsh)->size;
951 	     iter_bkt++, chain_cnt = 0) {
952 		iter_list = &rcu_dereference(netlbl_domhsh)->tbl[iter_bkt];
953 		list_for_each_entry_rcu(iter_entry, iter_list, list)
954 			if (iter_entry->valid) {
955 				if (chain_cnt++ < *skip_chain)
956 					continue;
957 				ret_val = callback(iter_entry, cb_arg);
958 				if (ret_val < 0) {
959 					chain_cnt--;
960 					goto walk_return;
961 				}
962 			}
963 	}
964 
965 walk_return:
966 	rcu_read_unlock();
967 	*skip_bkt = iter_bkt;
968 	*skip_chain = chain_cnt;
969 	return ret_val;
970 }
971