aboutsummaryrefslogtreecommitdiff
path: root/net/netlabel/netlabel_kapi.c
blob: fd9229db075cbc64a74dcc25367bc4a478f79c90 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
/*
 * NetLabel Kernel API
 *
 * This file defines the kernel API for the NetLabel system.  The NetLabel
 * system manages static and dynamic label mappings for network protocols such
 * as CIPSO and RIPSO.
 *
 * Author: Paul Moore <paul.moore@hp.com>
 *
 */

/*
 * (c) Copyright Hewlett-Packard Development Company, L.P., 2006, 2008
 *
 * This program is free software;  you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY;  without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
 * the GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program;  if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 *
 */

#include <linux/init.h>
#include <linux/types.h>
#include <linux/audit.h>
#include <linux/in.h>
#include <linux/in6.h>
#include <net/ip.h>
#include <net/ipv6.h>
#include <net/netlabel.h>
#include <net/cipso_ipv4.h>
#include <asm/bug.h>
#include <asm/atomic.h>

#include "netlabel_domainhash.h"
#include "netlabel_unlabeled.h"
#include "netlabel_cipso_v4.h"
#include "netlabel_user.h"
#include "netlabel_mgmt.h"
#include "netlabel_addrlist.h"

/*
 * Configuration Functions
 */

/**
 * netlbl_cfg_map_del - Remove a NetLabel/LSM domain mapping
 * @domain: the domain mapping to remove
 * @family: address family
 * @addr: IP address
 * @mask: IP address mask
 * @audit_info: NetLabel audit information
 *
 * Description:
 * Removes a NetLabel/LSM domain mapping.  A @domain value of NULL causes the
 * default domain mapping to be removed.  Returns zero on success, negative
 * values on failure.
 *
 */
int netlbl_cfg_map_del(const char *domain,
		       u16 family,
		       const void *addr,
		       const void *mask,
		       struct netlbl_audit *audit_info)
{
	if (addr == NULL && mask == NULL) {
		return netlbl_domhsh_remove(domain, audit_info);
	} else if (addr != NULL && mask != NULL) {
		switch (family) {
		case AF_INET:
			return netlbl_domhsh_remove_af4(domain, addr, mask,
							audit_info);
		default:
			return -EPFNOSUPPORT;
		}
	} else
		return -EINVAL;
}

/**
 * netlbl_cfg_unlbl_map_add - Add a new unlabeled mapping
 * @domain: the domain mapping to add
 * @family: address family
 * @addr: IP address
 * @mask: IP address mask
 * @audit_info: NetLabel audit information
 *
 * Description:
 * Adds a new unlabeled NetLabel/LSM domain mapping.  A @domain value of NULL
 * causes a new default domain mapping to be added.  Returns zero on success,
 * negative values on failure.
 *
 */
int netlbl_cfg_unlbl_map_add(const char *domain,
			     u16 family,
			     const void *addr,
			     const void *mask,
			     struct netlbl_audit *audit_info)
{
	int ret_val = -ENOMEM;
	struct netlbl_dom_map *entry;
	struct netlbl_domaddr_map *addrmap = NULL;
	struct netlbl_domaddr4_map *map4 = NULL;
	struct netlbl_domaddr6_map *map6 = NULL;
	const struct in_addr *addr4, *mask4;
	const struct in6_addr *addr6, *mask6;

	entry = kzalloc(sizeof(*entry), GFP_ATOMIC);
	if (entry == NULL)
		return -ENOMEM;
	if (domain != NULL) {
		entry->domain = kstrdup(domain, GFP_ATOMIC);
		if (entry->domain == NULL)
			goto cfg_unlbl_map_add_failure;
	}

	if (addr == NULL && mask == NULL)
		entry->type = NETLBL_NLTYPE_UNLABELED;
	else if (addr != NULL && mask != NULL) {
		addrmap = kzalloc(sizeof(*addrmap), GFP_ATOMIC);
		if (addrmap == NULL)
			goto cfg_unlbl_map_add_failure;
		INIT_LIST_HEAD(&addrmap->list4);
		INIT_LIST_HEAD(&addrmap->list6);

		switch (family) {
		case AF_INET:
			addr4 = addr;
			mask4 = mask;
			map4 = kzalloc(sizeof(*map4), GFP_ATOMIC);
			if (map4 == NULL)
				goto cfg_unlbl_map_add_failure;
			map4->type = NETLBL_NLTYPE_UNLABELED;
			map4->list.addr = addr4->s_addr & mask4->s_addr;
			map4->list.mask = mask4->s_addr;
			map4->list.valid = 1;
			ret_val = netlbl_af4list_add(&map4->list,
						     &addrmap->list4);
			if (ret_val != 0)
				goto cfg_unlbl_map_add_failure;
			break;
		case AF_INET6:
			addr6 = addr;
			mask6 = mask;
			map6 = kzalloc(sizeof(*map6), GFP_ATOMIC);
			if (map4 == NULL)
				goto cfg_unlbl_map_add_failure;
			map6->type = NETLBL_NLTYPE_UNLABELED;
			ipv6_addr_copy(&map6->list.addr, addr6);
			map6->list.addr.s6_addr32[0] &= mask6->s6_addr32[0];
			map6->list.addr.s6_addr32[1] &= mask6->s6_addr32[1];
			map6->list.addr.s6_addr32[2] &= mask6->s6_addr32[2];
			map6->list.addr.s6_addr32[3] &= mask6->s6_addr32[3];
			ipv6_addr_copy(&map6->list.mask, mask6);
			map6->list.valid = 1;
			ret_val = netlbl_af4list_add(&map4->list,
						     &addrmap->list4);
			if (ret_val != 0)
				goto cfg_unlbl_map_add_failure;
			break;
		default:
			goto cfg_unlbl_map_add_failure;
			break;
		}

		entry->type_def.addrsel = addrmap;
		entry->type = NETLBL_NLTYPE_ADDRSELECT;
	} else {
		ret_val = -EINVAL;
		goto cfg_unlbl_map_add_failure;
	}

	ret_val = netlbl_domhsh_add(entry, audit_info);
	if (ret_val != 0)
		goto cfg_unlbl_map_add_failure;

	return 0;

cfg_unlbl_map_add_failure:
	if (entry != NULL)
		kfree(entry->domain);
	kfree(entry);
	kfree(addrmap);
	kfree(map4);
	kfree(map6);
	return ret_val;
}


/**
 * netlbl_cfg_unlbl_static_add - Adds a new static label
 * @net: network namespace
 * @dev_name: interface name
 * @addr: IP address in network byte order (struct in[6]_addr)
 * @mask: address mask in network byte order (struct in[6]_addr)
 * @family: address family
 * @secid: LSM secid value for the entry
 * @audit_info: NetLabel audit information
 *
 * Description:
 * Adds a new NetLabel static label to be used when protocol provided labels
 * are not present on incoming traffic.  If @dev_name is NULL then the default
 * interface will be used.  Returns zero on success, negative values on failure.
 *
 */
int netlbl_cfg_unlbl_static_add(struct net *net,
				const char *dev_name,
				const void *addr,
				const void *mask,
				u16 family,
				u32 secid,
				struct netlbl_audit *audit_info)
{
	u32 addr_len;

	switch (family) {
	case AF_INET:
		addr_len = sizeof(struct in_addr);
		break;
	case AF_INET6:
		addr_len = sizeof(struct in6_addr);
		break;
	default:
		return -EPFNOSUPPORT;
	}

	return netlbl_unlhsh_add(net,
				 dev_name, addr, mask, addr_len,
				 secid, audit_info);
}

/**
 * netlbl_cfg_unlbl_static_del - Removes an existing static label
 * @net: network namespace
 * @dev_name: interface name
 * @addr: IP address in network byte order (struct in[6]_addr)
 * @mask: address mask in network byte order (struct in[6]_addr)
 * @family: address family
 * @secid: LSM secid value for the entry
 * @audit_info: NetLabel audit information
 *
 * Description:
 * Removes an existing NetLabel static label used when protocol provided labels
 * are not present on incoming traffic.  If @dev_name is NULL then the default
 * interface will be used.  Returns zero on success, negative values on failure.
 *
 */
int netlbl_cfg_unlbl_static_del(struct net *net,
				const char *dev_name,
				const void *addr,
				const void *mask,
				u16 family,
				struct netlbl_audit *audit_info)
{
	u32 addr_len;

	switch (family) {
	case AF_INET:
		addr_len = sizeof(struct in_addr);
		break;
	case AF_INET6:
		addr_len = sizeof(struct in6_addr);
		break;
	default:
		return -EPFNOSUPPORT;
	}

	return netlbl_unlhsh_remove(net,
				    dev_name, addr, mask, addr_len,
				    audit_info);
}

/**
 * netlbl_cfg_cipsov4_add - Add a new CIPSOv4 DOI definition
 * @doi_def: CIPSO DOI definition
 * @audit_info: NetLabel audit information
 *
 * Description:
 * Add a new CIPSO DOI definition as defined by @doi_def.  Returns zero on
 * success and negative values on failure.
 *
 */
int netlbl_cfg_cipsov4_add(struct cipso_v4_doi *doi_def,
			   struct netlbl_audit *audit_info)
{
	return cipso_v4_doi_add(doi_def, audit_info);
}

/**
 * netlbl_cfg_cipsov4_del - Remove an existing CIPSOv4 DOI definition
 * @doi: CIPSO DOI
 * @audit_info: NetLabel audit information
 *
 * Description:
 * Remove an existing CIPSO DOI definition matching @doi.  Returns zero on
 * success and negative values on failure.
 *
 */
void netlbl_cfg_cipsov4_del(u32 doi, struct netlbl_audit *audit_info)
{
	cipso_v4_doi_remove(doi, audit_info);
}

/**
 * netlbl_cfg_cipsov4_map_add - Add a new CIPSOv4 DOI mapping
 * @doi: the CIPSO DOI
 * @domain: the domain mapping to add
 * @addr: IP address
 * @mask: IP address mask
 * @audit_info: NetLabel audit information
 *
 * Description:
 * Add a new NetLabel/LSM domain mapping for the given CIPSO DOI to the NetLabel
 * subsystem.  A @domain value of NULL adds a new default domain mapping.
 * Returns zero on success, negative values on failure.
 *
 */
int netlbl_cfg_cipsov4_map_add(u32 doi,
			       const char *domain,
			       const struct in_addr *addr,
			       const struct in_addr *mask,
			       struct netlbl_audit *audit_info)
{
	int ret_val = -ENOMEM;
	struct cipso_v4_doi *doi_def;
	struct netlbl_dom_map *entry;
	struct netlbl_domaddr_map *addrmap = NULL;
	struct netlbl_domaddr4_map *addrinfo = NULL;

	doi_def = cipso_v4_doi_getdef(doi);
	if (doi_def == NULL)
		return -ENOENT;

	entry = kzalloc(sizeof(*entry), GFP_ATOMIC);
	if (entry == NULL)
		return -ENOMEM;
	if (domain != NULL) {
		entry->domain = kstrdup(domain, GFP_ATOMIC);
		if (entry->domain == NULL)
			goto cfg_cipsov4_map_add_failure;
	}

	if (addr == NULL && mask == NULL) {
		entry->type_def.cipsov4 = doi_def;
		entry->type = NETLBL_NLTYPE_CIPSOV4;
	} else if (addr != NULL && mask != NULL) {
		addrmap = kzalloc(sizeof(*addrmap), GFP_ATOMIC);
		if (addrmap == NULL)
			goto cfg_cipsov4_map_add_failure;
		INIT_LIST_HEAD(&addrmap->list4);
		INIT_LIST_HEAD(&addrmap->list6);

		addrinfo = kzalloc(sizeof(*addrinfo), GFP_ATOMIC);
		if (addrinfo == NULL)
			goto cfg_cipsov4_map_add_failure;
		addrinfo->type_def.cipsov4 = doi_def;
		addrinfo->type = NETLBL_NLTYPE_CIPSOV4;
		addrinfo->list.addr = addr->s_addr & mask->s_addr;
		addrinfo->list.mask = mask->s_addr;
		addrinfo->list.valid = 1;
		ret_val = netlbl_af4list_add(&addrinfo->list, &addrmap->list4);
		if (ret_val != 0)
			goto cfg_cipsov4_map_add_failure;

		entry->type_def.addrsel = addrmap;
		entry->type = NETLBL_NLTYPE_ADDRSELECT;
	} else {
		ret_val = -EINVAL;
		goto cfg_cipsov4_map_add_failure;
	}

	ret_val = netlbl_domhsh_add(entry, audit_info);
	if (ret_val != 0)
		goto cfg_cipsov4_map_add_failure;

	return 0;

cfg_cipsov4_map_add_failure:
	cipso_v4_doi_putdef(doi_def);
	if (entry != NULL)
		kfree(entry->domain);
	kfree(entry);
	kfree(addrmap);
	kfree(addrinfo);
	return ret_val;
}

/*
 * Security Attribute Functions
 */

/**
 * netlbl_secattr_catmap_walk - Walk a LSM secattr catmap looking for a bit
 * @catmap: the category bitmap
 * @offset: the offset to start searching at, in bits
 *
 * Description:
 * This function walks a LSM secattr category bitmap starting at @offset and
 * returns the spot of the first set bit or -ENOENT if no bits are set.
 *
 */
int netlbl_secattr_catmap_walk(struct netlbl_lsm_secattr_catmap *catmap,
			       u32 offset)
{
	struct netlbl_lsm_secattr_catmap *iter = catmap;
	u32 node_idx;
	u32 node_bit;
	NETLBL_CATMAP_MAPTYPE bitmap;

	if (offset > iter->startbit) {
		while (offset >= (iter->startbit + NETLBL_CATMAP_SIZE)) {
			iter = iter->next;
			if (iter == NULL)
				return -ENOENT;
		}
		node_idx = (offset - iter->startbit) / NETLBL_CATMAP_MAPSIZE;
		node_bit = offset - iter->startbit -
			   (NETLBL_CATMAP_MAPSIZE * node_idx);
	} else {
		node_idx = 0;
		node_bit = 0;
	}
	bitmap = iter->bitmap[node_idx] >> node_bit;

	for (;;) {
		if (bitmap != 0) {
			while ((bitmap & NETLBL_CATMAP_BIT) == 0) {
				bitmap >>= 1;
				node_bit++;
			}
			return iter->startbit +
				(NETLBL_CATMAP_MAPSIZE * node_idx) + node_bit;
		}
		if (++node_idx >= NETLBL_CATMAP_MAPCNT) {
			if (iter->next != NULL) {
				iter = iter->next;
				node_idx = 0;
			} else
				return -ENOENT;
		}
		bitmap = iter->bitmap[node_idx];
		node_bit = 0;
	}

	return -ENOENT;
}

/**
 * netlbl_secattr_catmap_walk_rng - Find the end of a string of set bits
 * @catmap: the category bitmap
 * @offset: the offset to start searching at, in bits
 *
 * Description:
 * This function walks a LSM secattr category bitmap starting at @offset and
 * returns the spot of the first cleared bit or -ENOENT if the offset is past
 * the end of the bitmap.
 *
 */
int netlbl_secattr_catmap_walk_rng(struct netlbl_lsm_secattr_catmap *catmap,
				   u32 offset)
{
	struct netlbl_lsm_secattr_catmap *iter = catmap;
	u32 node_idx;
	u32 node_bit;
	NETLBL_CATMAP_MAPTYPE bitmask;
	NETLBL_CATMAP_MAPTYPE bitmap;

	if (offset > iter->startbit) {
		while (offset >= (iter->startbit + NETLBL_CATMAP_SIZE)) {
			iter = iter->next;
			if (iter == NULL)
				return -ENOENT;
		}
		node_idx = (offset - iter->startbit) / NETLBL_CATMAP_MAPSIZE;
		node_bit = offset - iter->startbit -
			   (NETLBL_CATMAP_MAPSIZE * node_idx);
	} else {
		node_idx = 0;
		node_bit = 0;
	}
	bitmask = NETLBL_CATMAP_BIT << node_bit;

	for (;;) {
		bitmap = iter->bitmap[node_idx];
		while (bitmask != 0 && (bitmap & bitmask) != 0) {
			bitmask <<= 1;
			node_bit++;
		}

		if (bitmask != 0)
			return iter->startbit +
				(NETLBL_CATMAP_MAPSIZE * node_idx) +
				node_bit - 1;
		else if (++node_idx >= NETLBL_CATMAP_MAPCNT) {
			if (iter->next == NULL)
				return iter->startbit +	NETLBL_CATMAP_SIZE - 1;
			iter = iter->next;
			node_idx = 0;
		}
		bitmask = NETLBL_CATMAP_BIT;
		node_bit = 0;
	}

	return -ENOENT;
}

/**
 * netlbl_secattr_catmap_setbit - Set a bit in a LSM secattr catmap
 * @catmap: the category bitmap
 * @bit: the bit to set
 * @flags: memory allocation flags
 *
 * Description:
 * Set the bit specified by @bit in @catmap.  Returns zero on success,
 * negative values on failure.
 *
 */
int netlbl_secattr_catmap_setbit(struct netlbl_lsm_secattr_catmap *catmap,
				 u32 bit,
				 gfp_t flags)
{
	struct netlbl_lsm_secattr_catmap *iter = catmap;
	u32 node_bit;
	u32 node_idx;

	while (iter->next != NULL &&
	       bit >= (iter->startbit + NETLBL_CATMAP_SIZE))
		iter = iter->next;
	if (bit >= (iter->startbit + NETLBL_CATMAP_SIZE)) {
		iter->next = netlbl_secattr_catmap_alloc(flags);
		if (iter->next == NULL)
			return -ENOMEM;
		iter = iter->next;
		iter->startbit = bit & ~(NETLBL_CATMAP_SIZE - 1);
	}

	/* gcc always rounds to zero when doing integer division */
	node_idx = (bit - iter->startbit) / NETLBL_CATMAP_MAPSIZE;
	node_bit = bit - iter->startbit - (NETLBL_CATMAP_MAPSIZE * node_idx);
	iter->bitmap[node_idx] |= NETLBL_CATMAP_BIT << node_bit;

	return 0;
}

/**
 * netlbl_secattr_catmap_setrng - Set a range of bits in a LSM secattr catmap
 * @catmap: the category bitmap
 * @start: the starting bit
 * @end: the last bit in the string
 * @flags: memory allocation flags
 *
 * Description:
 * Set a range of bits, starting at @start and ending with @end.  Returns zero
 * on success, negative values on failure.
 *
 */
int netlbl_secattr_catmap_setrng(struct netlbl_lsm_secattr_catmap *catmap,
				 u32 start,
				 u32 end,
				 gfp_t flags)
{
	int ret_val = 0;
	struct netlbl_lsm_secattr_catmap *iter = catmap;
	u32 iter_max_spot;
	u32 spot;

	/* XXX - This could probably be made a bit faster by combining writes
	 * to the catmap instead of setting a single bit each time, but for
	 * right now skipping to the start of the range in the catmap should
	 * be a nice improvement over calling the individual setbit function
	 * repeatedly from a loop. */

	while (iter->next != NULL &&
	       start >= (iter->startbit + NETLBL_CATMAP_SIZE))
		iter = iter->next;
	iter_max_spot = iter->startbit + NETLBL_CATMAP_SIZE;

	for (spot = start; spot <= end && ret_val == 0; spot++) {
		if (spot >= iter_max_spot && iter->next != NULL) {
			iter = iter->next;
			iter_max_spot = iter->startbit + NETLBL_CATMAP_SIZE;
		}
		ret_val = netlbl_secattr_catmap_setbit(iter, spot, GFP_ATOMIC);
	}

	return ret_val;
}

/*
 * LSM Functions
 */

/**
 * netlbl_enabled - Determine if the NetLabel subsystem is enabled
 *
 * Description:
 * The LSM can use this function to determine if it should use NetLabel
 * security attributes in it's enforcement mechanism.  Currently, NetLabel is
 * considered to be enabled when it's configuration contains a valid setup for
 * at least one labeled protocol (i.e. NetLabel can understand incoming
 * labeled packets of at least one type); otherwise NetLabel is considered to
 * be disabled.
 *
 */
int netlbl_enabled(void)
{
	/* At some point we probably want to expose this mechanism to the user
	 * as well so that admins can toggle NetLabel regardless of the
	 * configuration */
	return (atomic_read(&netlabel_mgmt_protocount) > 0);
}

/**
 * netlbl_socket_setattr - Label a socket using the correct protocol
 * @sk: the socket to label
 * @secattr: the security attributes
 *
 * Description:
 * Attach the correct label to the given socket using the security attributes
 * specified in @secattr.  This function requires exclusive access to @sk,
 * which means it either needs to be in the process of being created or locked.
 * Returns zero on success, -EDESTADDRREQ if the domain is configured to use
 * network address selectors (can't blindly label the socket), and negative
 * values on all other failures.
 *
 */
int netlbl_sock_setattr(struct sock *sk,
			const struct netlbl_lsm_secattr *secattr)
{
	int ret_val = -ENOENT;
	struct netlbl_dom_map *dom_entry;

	rcu_read_lock();
	dom_entry = netlbl_domhsh_getentry(secattr->domain);
	if (dom_entry == NULL)
		goto socket_setattr_return;
	switch (dom_entry->type) {
	case NETLBL_NLTYPE_ADDRSELECT:
		ret_val = -EDESTADDRREQ;
		break;
	case NETLBL_NLTYPE_CIPSOV4:
		ret_val = cipso_v4_sock_setattr(sk,
						dom_entry->type_def.cipsov4,
						secattr);
		break;
	case NETLBL_NLTYPE_UNLABELED:
		ret_val = 0;
		break;
	default:
		ret_val = -ENOENT;
	}

socket_setattr_return:
	rcu_read_unlock();
	return ret_val;
}

/**
 * netlbl_sock_delattr - Delete all the NetLabel labels on a socket
 * @sk: the socket
 *
 * Description:
 * Remove all the NetLabel labeling from @sk.  The caller is responsible for
 * ensuring that @sk is locked.
 *
 */
void netlbl_sock_delattr(struct sock *sk)
{
	cipso_v4_sock_delattr(sk);
}

/**
 * netlbl_sock_getattr - Determine the security attributes of a sock
 * @sk: the sock
 * @secattr: the security attributes
 *
 * Description:
 * Examines the given sock to see if any NetLabel style labeling has been
 * applied to the sock, if so it parses the socket label and returns the
 * security attributes in @secattr.  Returns zero on success, negative values
 * on failure.
 *
 */
int netlbl_sock_getattr(struct sock *sk, struct netlbl_lsm_secattr *secattr)
{
	return cipso_v4_sock_getattr(sk, secattr);
}

/**
 * netlbl_conn_setattr - Label a connected socket using the correct protocol
 * @sk: the socket to label
 * @addr: the destination address
 * @secattr: the security attributes
 *
 * Description:
 * Attach the correct label to the given connected socket using the security
 * attributes specified in @secattr.  The caller is responsible for ensuring
 * that @sk is locked.  Returns zero on success, negative values on failure.
 *
 */
int netlbl_conn_setattr(struct sock *sk,
			struct sockaddr *addr,
			const struct netlbl_lsm_secattr *secattr)
{
	int ret_val;
	struct sockaddr_in *addr4;
	struct netlbl_domaddr4_map *af4_entry;

	rcu_read_lock();
	switch (addr->sa_family) {
	case AF_INET:
		addr4 = (struct sockaddr_in *)addr;
		af4_entry = netlbl_domhsh_getentry_af4(secattr->domain,
						       addr4->sin_addr.s_addr);
		if (af4_entry == NULL) {
			ret_val = -ENOENT;
			goto conn_setattr_return;
		}
		switch (af4_entry->type) {
		case NETLBL_NLTYPE_CIPSOV4:
			ret_val = cipso_v4_sock_setattr(sk,
						   af4_entry->type_def.cipsov4,
						   secattr);
			break;
		case NETLBL_NLTYPE_UNLABELED:
			/* just delete the protocols we support for right now
			 * but we could remove other protocols if needed */
			cipso_v4_sock_delattr(sk);
			ret_val = 0;
			break;
		default:
			ret_val = -ENOENT;
		}
		break;
#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
	case AF_INET6:
		/* since we don't support any IPv6 labeling protocols right
		 * now we can optimize everything away until we do */
		ret_val = 0;
		break;
#endif /* IPv6 */
	default:
		ret_val = 0;
	}

conn_setattr_return:
	rcu_read_unlock();
	return ret_val;
}

/**
 * netlbl_skbuff_setattr - Label a packet using the correct protocol
 * @skb: the packet
 * @family: protocol family
 * @secattr: the security attributes
 *
 * Description:
 * Attach the correct label to the given packet using the security attributes
 * specified in @secattr.  Returns zero on success, negative values on failure.
 *
 */
int netlbl_skbuff_setattr(struct sk_buff *skb,
			  u16 family,
			  const struct netlbl_lsm_secattr *secattr)
{
	int ret_val;
	struct iphdr *hdr4;
	struct netlbl_domaddr4_map *af4_entry;

	rcu_read_lock();
	switch (family) {
	case AF_INET:
		hdr4 = ip_hdr(skb);
		af4_entry = netlbl_domhsh_getentry_af4(secattr->domain,
						       hdr4->daddr);
		if (af4_entry == NULL) {
			ret_val = -ENOENT;
			goto skbuff_setattr_return;
		}
		switch (af4_entry->type) {
		case NETLBL_NLTYPE_CIPSOV4:
			ret_val = cipso_v4_skbuff_setattr(skb,
						   af4_entry->type_def.cipsov4,
						   secattr);
			break;
		case NETLBL_NLTYPE_UNLABELED:
			/* just delete the protocols we support for right now
			 * but we could remove other protocols if needed */
			ret_val = cipso_v4_skbuff_delattr(skb);
			break;
		default:
			ret_val = -ENOENT;
		}
		break;
#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
	case AF_INET6:
		/* since we don't support any IPv6 labeling protocols right
		 * now we can optimize everything away until we do */
		ret_val = 0;
		break;
#endif /* IPv6 */
	default:
		ret_val = 0;
	}

skbuff_setattr_return:
	rcu_read_unlock();
	return ret_val;
}

/**
 * netlbl_skbuff_getattr - Determine the security attributes of a packet
 * @skb: the packet
 * @family: protocol family
 * @secattr: the security attributes
 *
 * Description:
 * Examines the given packet to see if a recognized form of packet labeling
 * is present, if so it parses the packet label and returns the security
 * attributes in @secattr.  Returns zero on success, negative values on
 * failure.
 *
 */
int netlbl_skbuff_getattr(const struct sk_buff *skb,
			  u16 family,
			  struct netlbl_lsm_secattr *secattr)
{
	if (CIPSO_V4_OPTEXIST(skb) &&
	    cipso_v4_skbuff_getattr(skb, secattr) == 0)
		return 0;

	return netlbl_unlabel_getattr(skb, family, secattr);
}

/**
 * netlbl_skbuff_err - Handle a LSM error on a sk_buff
 * @skb: the packet
 * @error: the error code
 * @gateway: true if host is acting as a gateway, false otherwise
 *
 * Description:
 * Deal with a LSM problem when handling the packet in @skb, typically this is
 * a permission denied problem (-EACCES).  The correct action is determined
 * according to the packet's labeling protocol.
 *
 */
void netlbl_skbuff_err(struct sk_buff *skb, int error, int gateway)
{
	if (CIPSO_V4_OPTEXIST(skb))
		cipso_v4_error(skb, error, gateway);
}

/**
 * netlbl_cache_invalidate - Invalidate all of the NetLabel protocol caches
 *
 * Description:
 * For all of the NetLabel protocols that support some form of label mapping
 * cache, invalidate the cache.  Returns zero on success, negative values on
 * error.
 *
 */
void netlbl_cache_invalidate(void)
{
	cipso_v4_cache_invalidate();
}

/**
 * netlbl_cache_add - Add an entry to a NetLabel protocol cache
 * @skb: the packet
 * @secattr: the packet's security attributes
 *
 * Description:
 * Add the LSM security attributes for the given packet to the underlying
 * NetLabel protocol's label mapping cache.  Returns zero on success, negative
 * values on error.
 *
 */
int netlbl_cache_add(const struct sk_buff *skb,
		     const struct netlbl_lsm_secattr *secattr)
{
	if ((secattr->flags & NETLBL_SECATTR_CACHE) == 0)
		return -ENOMSG;

	if (CIPSO_V4_OPTEXIST(skb))
		return cipso_v4_cache_add(skb, secattr);

	return -ENOMSG;
}

/*
 * Protocol Engine Functions
 */

/**
 * netlbl_audit_start - Start an audit message
 * @type: audit message type
 * @audit_info: NetLabel audit information
 *
 * Description:
 * Start an audit message using the type specified in @type and fill the audit
 * message with some fields common to all NetLabel audit messages.  This
 * function should only be used by protocol engines, not LSMs.  Returns a
 * pointer to the audit buffer on success, NULL on failure.
 *
 */
struct audit_buffer *netlbl_audit_start(int type,
					struct netlbl_audit *audit_info)
{
	return netlbl_audit_start_common(type, audit_info);
}

/*
 * Setup Functions
 */

/**
 * netlbl_init - Initialize NetLabel
 *
 * Description:
 * Perform the required NetLabel initialization before first use.
 *
 */
static int __init netlbl_init(void)
{
	int ret_val;

	printk(KERN_INFO "NetLabel: Initializing\n");
	printk(KERN_INFO "NetLabel:  domain hash size = %u\n",
	       (1 << NETLBL_DOMHSH_BITSIZE));
	printk(KERN_INFO "NetLabel:  protocols ="
	       " UNLABELED"
	       " CIPSOv4"
	       "\n");

	ret_val = netlbl_domhsh_init(NETLBL_DOMHSH_BITSIZE);
	if (ret_val != 0)
		goto init_failure;

	ret_val = netlbl_unlabel_init(NETLBL_UNLHSH_BITSIZE);
	if (ret_val != 0)
		goto init_failure;

	ret_val = netlbl_netlink_init();
	if (ret_val != 0)
		goto init_failure;

	ret_val = netlbl_unlabel_defconf();
	if (ret_val != 0)
		goto init_failure;
	printk(KERN_INFO "NetLabel:  unlabeled traffic allowed by default\n");

	return 0;

init_failure:
	panic("NetLabel: failed to initialize properly (%d)\n", ret_val);
}

subsys_initcall(netlbl_init);