xref: /linux/net/netlabel/netlabel_cipso_v4.c (revision 05f6d02521d4c7a656c5135d6d81c345ce531ac0)
1 /*
2  * NetLabel CIPSO/IPv4 Support
3  *
4  * This file defines the CIPSO/IPv4 functions for the NetLabel system.  The
5  * NetLabel system manages static and dynamic label mappings for network
6  * protocols such as CIPSO and RIPSO.
7  *
8  * Author: Paul Moore <paul@paul-moore.com>
9  *
10  */
11 
12 /*
13  * (c) Copyright Hewlett-Packard Development Company, L.P., 2006
14  *
15  * This program is free software;  you can redistribute it and/or modify
16  * it under the terms of the GNU General Public License as published by
17  * the Free Software Foundation; either version 2 of the License, or
18  * (at your option) any later version.
19  *
20  * This program is distributed in the hope that it will be useful,
21  * but WITHOUT ANY WARRANTY;  without even the implied warranty of
22  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
23  * the GNU General Public License for more details.
24  *
25  * You should have received a copy of the GNU General Public License
26  * along with this program;  if not, see <http://www.gnu.org/licenses/>.
27  *
28  */
29 
30 #include <linux/types.h>
31 #include <linux/socket.h>
32 #include <linux/string.h>
33 #include <linux/skbuff.h>
34 #include <linux/audit.h>
35 #include <linux/slab.h>
36 #include <net/sock.h>
37 #include <net/netlink.h>
38 #include <net/genetlink.h>
39 #include <net/netlabel.h>
40 #include <net/cipso_ipv4.h>
41 #include <linux/atomic.h>
42 
43 #include "netlabel_user.h"
44 #include "netlabel_cipso_v4.h"
45 #include "netlabel_mgmt.h"
46 #include "netlabel_domainhash.h"
47 
48 /* Argument struct for cipso_v4_doi_walk() */
49 struct netlbl_cipsov4_doiwalk_arg {
50 	struct netlink_callback *nl_cb;
51 	struct sk_buff *skb;
52 	u32 seq;
53 };
54 
55 /* Argument struct for netlbl_domhsh_walk() */
56 struct netlbl_domhsh_walk_arg {
57 	struct netlbl_audit *audit_info;
58 	u32 doi;
59 };
60 
61 /* NetLabel Generic NETLINK CIPSOv4 family */
62 static struct genl_family netlbl_cipsov4_gnl_family = {
63 	.id = GENL_ID_GENERATE,
64 	.hdrsize = 0,
65 	.name = NETLBL_NLTYPE_CIPSOV4_NAME,
66 	.version = NETLBL_PROTO_VERSION,
67 	.maxattr = NLBL_CIPSOV4_A_MAX,
68 };
69 
70 /* NetLabel Netlink attribute policy */
71 static const struct nla_policy netlbl_cipsov4_genl_policy[NLBL_CIPSOV4_A_MAX + 1] = {
72 	[NLBL_CIPSOV4_A_DOI] = { .type = NLA_U32 },
73 	[NLBL_CIPSOV4_A_MTYPE] = { .type = NLA_U32 },
74 	[NLBL_CIPSOV4_A_TAG] = { .type = NLA_U8 },
75 	[NLBL_CIPSOV4_A_TAGLST] = { .type = NLA_NESTED },
76 	[NLBL_CIPSOV4_A_MLSLVLLOC] = { .type = NLA_U32 },
77 	[NLBL_CIPSOV4_A_MLSLVLREM] = { .type = NLA_U32 },
78 	[NLBL_CIPSOV4_A_MLSLVL] = { .type = NLA_NESTED },
79 	[NLBL_CIPSOV4_A_MLSLVLLST] = { .type = NLA_NESTED },
80 	[NLBL_CIPSOV4_A_MLSCATLOC] = { .type = NLA_U32 },
81 	[NLBL_CIPSOV4_A_MLSCATREM] = { .type = NLA_U32 },
82 	[NLBL_CIPSOV4_A_MLSCAT] = { .type = NLA_NESTED },
83 	[NLBL_CIPSOV4_A_MLSCATLST] = { .type = NLA_NESTED },
84 };
85 
86 /*
87  * Helper Functions
88  */
89 
90 /**
91  * netlbl_cipsov4_add_common - Parse the common sections of a ADD message
92  * @info: the Generic NETLINK info block
93  * @doi_def: the CIPSO V4 DOI definition
94  *
95  * Description:
96  * Parse the common sections of a ADD message and fill in the related values
97  * in @doi_def.  Returns zero on success, negative values on failure.
98  *
99  */
100 static int netlbl_cipsov4_add_common(struct genl_info *info,
101 				     struct cipso_v4_doi *doi_def)
102 {
103 	struct nlattr *nla;
104 	int nla_rem;
105 	u32 iter = 0;
106 
107 	doi_def->doi = nla_get_u32(info->attrs[NLBL_CIPSOV4_A_DOI]);
108 
109 	if (nla_validate_nested(info->attrs[NLBL_CIPSOV4_A_TAGLST],
110 				NLBL_CIPSOV4_A_MAX,
111 				netlbl_cipsov4_genl_policy) != 0)
112 		return -EINVAL;
113 
114 	nla_for_each_nested(nla, info->attrs[NLBL_CIPSOV4_A_TAGLST], nla_rem)
115 		if (nla_type(nla) == NLBL_CIPSOV4_A_TAG) {
116 			if (iter >= CIPSO_V4_TAG_MAXCNT)
117 				return -EINVAL;
118 			doi_def->tags[iter++] = nla_get_u8(nla);
119 		}
120 	while (iter < CIPSO_V4_TAG_MAXCNT)
121 		doi_def->tags[iter++] = CIPSO_V4_TAG_INVALID;
122 
123 	return 0;
124 }
125 
126 /*
127  * NetLabel Command Handlers
128  */
129 
130 /**
131  * netlbl_cipsov4_add_std - Adds a CIPSO V4 DOI definition
132  * @info: the Generic NETLINK info block
133  * @audit_info: NetLabel audit information
134  *
135  * Description:
136  * Create a new CIPSO_V4_MAP_TRANS DOI definition based on the given ADD
137  * message and add it to the CIPSO V4 engine.  Return zero on success and
138  * non-zero on error.
139  *
140  */
141 static int netlbl_cipsov4_add_std(struct genl_info *info,
142 				  struct netlbl_audit *audit_info)
143 {
144 	int ret_val = -EINVAL;
145 	struct cipso_v4_doi *doi_def = NULL;
146 	struct nlattr *nla_a;
147 	struct nlattr *nla_b;
148 	int nla_a_rem;
149 	int nla_b_rem;
150 	u32 iter;
151 
152 	if (!info->attrs[NLBL_CIPSOV4_A_TAGLST] ||
153 	    !info->attrs[NLBL_CIPSOV4_A_MLSLVLLST])
154 		return -EINVAL;
155 
156 	if (nla_validate_nested(info->attrs[NLBL_CIPSOV4_A_MLSLVLLST],
157 				NLBL_CIPSOV4_A_MAX,
158 				netlbl_cipsov4_genl_policy) != 0)
159 		return -EINVAL;
160 
161 	doi_def = kmalloc(sizeof(*doi_def), GFP_KERNEL);
162 	if (doi_def == NULL)
163 		return -ENOMEM;
164 	doi_def->map.std = kzalloc(sizeof(*doi_def->map.std), GFP_KERNEL);
165 	if (doi_def->map.std == NULL) {
166 		ret_val = -ENOMEM;
167 		goto add_std_failure;
168 	}
169 	doi_def->type = CIPSO_V4_MAP_TRANS;
170 
171 	ret_val = netlbl_cipsov4_add_common(info, doi_def);
172 	if (ret_val != 0)
173 		goto add_std_failure;
174 	ret_val = -EINVAL;
175 
176 	nla_for_each_nested(nla_a,
177 			    info->attrs[NLBL_CIPSOV4_A_MLSLVLLST],
178 			    nla_a_rem)
179 		if (nla_type(nla_a) == NLBL_CIPSOV4_A_MLSLVL) {
180 			if (nla_validate_nested(nla_a,
181 					    NLBL_CIPSOV4_A_MAX,
182 					    netlbl_cipsov4_genl_policy) != 0)
183 					goto add_std_failure;
184 			nla_for_each_nested(nla_b, nla_a, nla_b_rem)
185 				switch (nla_type(nla_b)) {
186 				case NLBL_CIPSOV4_A_MLSLVLLOC:
187 					if (nla_get_u32(nla_b) >
188 					    CIPSO_V4_MAX_LOC_LVLS)
189 						goto add_std_failure;
190 					if (nla_get_u32(nla_b) >=
191 					    doi_def->map.std->lvl.local_size)
192 					     doi_def->map.std->lvl.local_size =
193 						     nla_get_u32(nla_b) + 1;
194 					break;
195 				case NLBL_CIPSOV4_A_MLSLVLREM:
196 					if (nla_get_u32(nla_b) >
197 					    CIPSO_V4_MAX_REM_LVLS)
198 						goto add_std_failure;
199 					if (nla_get_u32(nla_b) >=
200 					    doi_def->map.std->lvl.cipso_size)
201 					     doi_def->map.std->lvl.cipso_size =
202 						     nla_get_u32(nla_b) + 1;
203 					break;
204 				}
205 		}
206 	doi_def->map.std->lvl.local = kcalloc(doi_def->map.std->lvl.local_size,
207 					      sizeof(u32),
208 					      GFP_KERNEL);
209 	if (doi_def->map.std->lvl.local == NULL) {
210 		ret_val = -ENOMEM;
211 		goto add_std_failure;
212 	}
213 	doi_def->map.std->lvl.cipso = kcalloc(doi_def->map.std->lvl.cipso_size,
214 					      sizeof(u32),
215 					      GFP_KERNEL);
216 	if (doi_def->map.std->lvl.cipso == NULL) {
217 		ret_val = -ENOMEM;
218 		goto add_std_failure;
219 	}
220 	for (iter = 0; iter < doi_def->map.std->lvl.local_size; iter++)
221 		doi_def->map.std->lvl.local[iter] = CIPSO_V4_INV_LVL;
222 	for (iter = 0; iter < doi_def->map.std->lvl.cipso_size; iter++)
223 		doi_def->map.std->lvl.cipso[iter] = CIPSO_V4_INV_LVL;
224 	nla_for_each_nested(nla_a,
225 			    info->attrs[NLBL_CIPSOV4_A_MLSLVLLST],
226 			    nla_a_rem)
227 		if (nla_type(nla_a) == NLBL_CIPSOV4_A_MLSLVL) {
228 			struct nlattr *lvl_loc;
229 			struct nlattr *lvl_rem;
230 
231 			lvl_loc = nla_find_nested(nla_a,
232 						  NLBL_CIPSOV4_A_MLSLVLLOC);
233 			lvl_rem = nla_find_nested(nla_a,
234 						  NLBL_CIPSOV4_A_MLSLVLREM);
235 			if (lvl_loc == NULL || lvl_rem == NULL)
236 				goto add_std_failure;
237 			doi_def->map.std->lvl.local[nla_get_u32(lvl_loc)] =
238 				nla_get_u32(lvl_rem);
239 			doi_def->map.std->lvl.cipso[nla_get_u32(lvl_rem)] =
240 				nla_get_u32(lvl_loc);
241 		}
242 
243 	if (info->attrs[NLBL_CIPSOV4_A_MLSCATLST]) {
244 		if (nla_validate_nested(info->attrs[NLBL_CIPSOV4_A_MLSCATLST],
245 					NLBL_CIPSOV4_A_MAX,
246 					netlbl_cipsov4_genl_policy) != 0)
247 			goto add_std_failure;
248 
249 		nla_for_each_nested(nla_a,
250 				    info->attrs[NLBL_CIPSOV4_A_MLSCATLST],
251 				    nla_a_rem)
252 			if (nla_type(nla_a) == NLBL_CIPSOV4_A_MLSCAT) {
253 				if (nla_validate_nested(nla_a,
254 					      NLBL_CIPSOV4_A_MAX,
255 					      netlbl_cipsov4_genl_policy) != 0)
256 					goto add_std_failure;
257 				nla_for_each_nested(nla_b, nla_a, nla_b_rem)
258 					switch (nla_type(nla_b)) {
259 					case NLBL_CIPSOV4_A_MLSCATLOC:
260 						if (nla_get_u32(nla_b) >
261 						    CIPSO_V4_MAX_LOC_CATS)
262 							goto add_std_failure;
263 						if (nla_get_u32(nla_b) >=
264 					      doi_def->map.std->cat.local_size)
265 					     doi_def->map.std->cat.local_size =
266 						     nla_get_u32(nla_b) + 1;
267 						break;
268 					case NLBL_CIPSOV4_A_MLSCATREM:
269 						if (nla_get_u32(nla_b) >
270 						    CIPSO_V4_MAX_REM_CATS)
271 							goto add_std_failure;
272 						if (nla_get_u32(nla_b) >=
273 					      doi_def->map.std->cat.cipso_size)
274 					     doi_def->map.std->cat.cipso_size =
275 						     nla_get_u32(nla_b) + 1;
276 						break;
277 					}
278 			}
279 		doi_def->map.std->cat.local = kcalloc(
280 					      doi_def->map.std->cat.local_size,
281 					      sizeof(u32),
282 					      GFP_KERNEL);
283 		if (doi_def->map.std->cat.local == NULL) {
284 			ret_val = -ENOMEM;
285 			goto add_std_failure;
286 		}
287 		doi_def->map.std->cat.cipso = kcalloc(
288 					      doi_def->map.std->cat.cipso_size,
289 					      sizeof(u32),
290 					      GFP_KERNEL);
291 		if (doi_def->map.std->cat.cipso == NULL) {
292 			ret_val = -ENOMEM;
293 			goto add_std_failure;
294 		}
295 		for (iter = 0; iter < doi_def->map.std->cat.local_size; iter++)
296 			doi_def->map.std->cat.local[iter] = CIPSO_V4_INV_CAT;
297 		for (iter = 0; iter < doi_def->map.std->cat.cipso_size; iter++)
298 			doi_def->map.std->cat.cipso[iter] = CIPSO_V4_INV_CAT;
299 		nla_for_each_nested(nla_a,
300 				    info->attrs[NLBL_CIPSOV4_A_MLSCATLST],
301 				    nla_a_rem)
302 			if (nla_type(nla_a) == NLBL_CIPSOV4_A_MLSCAT) {
303 				struct nlattr *cat_loc;
304 				struct nlattr *cat_rem;
305 
306 				cat_loc = nla_find_nested(nla_a,
307 						     NLBL_CIPSOV4_A_MLSCATLOC);
308 				cat_rem = nla_find_nested(nla_a,
309 						     NLBL_CIPSOV4_A_MLSCATREM);
310 				if (cat_loc == NULL || cat_rem == NULL)
311 					goto add_std_failure;
312 				doi_def->map.std->cat.local[
313 							nla_get_u32(cat_loc)] =
314 					nla_get_u32(cat_rem);
315 				doi_def->map.std->cat.cipso[
316 							nla_get_u32(cat_rem)] =
317 					nla_get_u32(cat_loc);
318 			}
319 	}
320 
321 	ret_val = cipso_v4_doi_add(doi_def, audit_info);
322 	if (ret_val != 0)
323 		goto add_std_failure;
324 	return 0;
325 
326 add_std_failure:
327 	cipso_v4_doi_free(doi_def);
328 	return ret_val;
329 }
330 
331 /**
332  * netlbl_cipsov4_add_pass - Adds a CIPSO V4 DOI definition
333  * @info: the Generic NETLINK info block
334  * @audit_info: NetLabel audit information
335  *
336  * Description:
337  * Create a new CIPSO_V4_MAP_PASS DOI definition based on the given ADD message
338  * and add it to the CIPSO V4 engine.  Return zero on success and non-zero on
339  * error.
340  *
341  */
342 static int netlbl_cipsov4_add_pass(struct genl_info *info,
343 				   struct netlbl_audit *audit_info)
344 {
345 	int ret_val;
346 	struct cipso_v4_doi *doi_def = NULL;
347 
348 	if (!info->attrs[NLBL_CIPSOV4_A_TAGLST])
349 		return -EINVAL;
350 
351 	doi_def = kmalloc(sizeof(*doi_def), GFP_KERNEL);
352 	if (doi_def == NULL)
353 		return -ENOMEM;
354 	doi_def->type = CIPSO_V4_MAP_PASS;
355 
356 	ret_val = netlbl_cipsov4_add_common(info, doi_def);
357 	if (ret_val != 0)
358 		goto add_pass_failure;
359 
360 	ret_val = cipso_v4_doi_add(doi_def, audit_info);
361 	if (ret_val != 0)
362 		goto add_pass_failure;
363 	return 0;
364 
365 add_pass_failure:
366 	cipso_v4_doi_free(doi_def);
367 	return ret_val;
368 }
369 
370 /**
371  * netlbl_cipsov4_add_local - Adds a CIPSO V4 DOI definition
372  * @info: the Generic NETLINK info block
373  * @audit_info: NetLabel audit information
374  *
375  * Description:
376  * Create a new CIPSO_V4_MAP_LOCAL DOI definition based on the given ADD
377  * message and add it to the CIPSO V4 engine.  Return zero on success and
378  * non-zero on error.
379  *
380  */
381 static int netlbl_cipsov4_add_local(struct genl_info *info,
382 				    struct netlbl_audit *audit_info)
383 {
384 	int ret_val;
385 	struct cipso_v4_doi *doi_def = NULL;
386 
387 	if (!info->attrs[NLBL_CIPSOV4_A_TAGLST])
388 		return -EINVAL;
389 
390 	doi_def = kmalloc(sizeof(*doi_def), GFP_KERNEL);
391 	if (doi_def == NULL)
392 		return -ENOMEM;
393 	doi_def->type = CIPSO_V4_MAP_LOCAL;
394 
395 	ret_val = netlbl_cipsov4_add_common(info, doi_def);
396 	if (ret_val != 0)
397 		goto add_local_failure;
398 
399 	ret_val = cipso_v4_doi_add(doi_def, audit_info);
400 	if (ret_val != 0)
401 		goto add_local_failure;
402 	return 0;
403 
404 add_local_failure:
405 	cipso_v4_doi_free(doi_def);
406 	return ret_val;
407 }
408 
409 /**
410  * netlbl_cipsov4_add - Handle an ADD message
411  * @skb: the NETLINK buffer
412  * @info: the Generic NETLINK info block
413  *
414  * Description:
415  * Create a new DOI definition based on the given ADD message and add it to the
416  * CIPSO V4 engine.  Returns zero on success, negative values on failure.
417  *
418  */
419 static int netlbl_cipsov4_add(struct sk_buff *skb, struct genl_info *info)
420 
421 {
422 	int ret_val = -EINVAL;
423 	struct netlbl_audit audit_info;
424 
425 	if (!info->attrs[NLBL_CIPSOV4_A_DOI] ||
426 	    !info->attrs[NLBL_CIPSOV4_A_MTYPE])
427 		return -EINVAL;
428 
429 	netlbl_netlink_auditinfo(skb, &audit_info);
430 	switch (nla_get_u32(info->attrs[NLBL_CIPSOV4_A_MTYPE])) {
431 	case CIPSO_V4_MAP_TRANS:
432 		ret_val = netlbl_cipsov4_add_std(info, &audit_info);
433 		break;
434 	case CIPSO_V4_MAP_PASS:
435 		ret_val = netlbl_cipsov4_add_pass(info, &audit_info);
436 		break;
437 	case CIPSO_V4_MAP_LOCAL:
438 		ret_val = netlbl_cipsov4_add_local(info, &audit_info);
439 		break;
440 	}
441 	if (ret_val == 0)
442 		atomic_inc(&netlabel_mgmt_protocount);
443 
444 	return ret_val;
445 }
446 
447 /**
448  * netlbl_cipsov4_list - Handle a LIST message
449  * @skb: the NETLINK buffer
450  * @info: the Generic NETLINK info block
451  *
452  * Description:
453  * Process a user generated LIST message and respond accordingly.  While the
454  * response message generated by the kernel is straightforward, determining
455  * before hand the size of the buffer to allocate is not (we have to generate
456  * the message to know the size).  In order to keep this function sane what we
457  * do is allocate a buffer of NLMSG_GOODSIZE and try to fit the response in
458  * that size, if we fail then we restart with a larger buffer and try again.
459  * We continue in this manner until we hit a limit of failed attempts then we
460  * give up and just send an error message.  Returns zero on success and
461  * negative values on error.
462  *
463  */
464 static int netlbl_cipsov4_list(struct sk_buff *skb, struct genl_info *info)
465 {
466 	int ret_val;
467 	struct sk_buff *ans_skb = NULL;
468 	u32 nlsze_mult = 1;
469 	void *data;
470 	u32 doi;
471 	struct nlattr *nla_a;
472 	struct nlattr *nla_b;
473 	struct cipso_v4_doi *doi_def;
474 	u32 iter;
475 
476 	if (!info->attrs[NLBL_CIPSOV4_A_DOI]) {
477 		ret_val = -EINVAL;
478 		goto list_failure;
479 	}
480 
481 list_start:
482 	ans_skb = nlmsg_new(NLMSG_DEFAULT_SIZE * nlsze_mult, GFP_KERNEL);
483 	if (ans_skb == NULL) {
484 		ret_val = -ENOMEM;
485 		goto list_failure;
486 	}
487 	data = genlmsg_put_reply(ans_skb, info, &netlbl_cipsov4_gnl_family,
488 				 0, NLBL_CIPSOV4_C_LIST);
489 	if (data == NULL) {
490 		ret_val = -ENOMEM;
491 		goto list_failure;
492 	}
493 
494 	doi = nla_get_u32(info->attrs[NLBL_CIPSOV4_A_DOI]);
495 
496 	rcu_read_lock();
497 	doi_def = cipso_v4_doi_getdef(doi);
498 	if (doi_def == NULL) {
499 		ret_val = -EINVAL;
500 		goto list_failure_lock;
501 	}
502 
503 	ret_val = nla_put_u32(ans_skb, NLBL_CIPSOV4_A_MTYPE, doi_def->type);
504 	if (ret_val != 0)
505 		goto list_failure_lock;
506 
507 	nla_a = nla_nest_start(ans_skb, NLBL_CIPSOV4_A_TAGLST);
508 	if (nla_a == NULL) {
509 		ret_val = -ENOMEM;
510 		goto list_failure_lock;
511 	}
512 	for (iter = 0;
513 	     iter < CIPSO_V4_TAG_MAXCNT &&
514 	       doi_def->tags[iter] != CIPSO_V4_TAG_INVALID;
515 	     iter++) {
516 		ret_val = nla_put_u8(ans_skb,
517 				     NLBL_CIPSOV4_A_TAG,
518 				     doi_def->tags[iter]);
519 		if (ret_val != 0)
520 			goto list_failure_lock;
521 	}
522 	nla_nest_end(ans_skb, nla_a);
523 
524 	switch (doi_def->type) {
525 	case CIPSO_V4_MAP_TRANS:
526 		nla_a = nla_nest_start(ans_skb, NLBL_CIPSOV4_A_MLSLVLLST);
527 		if (nla_a == NULL) {
528 			ret_val = -ENOMEM;
529 			goto list_failure_lock;
530 		}
531 		for (iter = 0;
532 		     iter < doi_def->map.std->lvl.local_size;
533 		     iter++) {
534 			if (doi_def->map.std->lvl.local[iter] ==
535 			    CIPSO_V4_INV_LVL)
536 				continue;
537 
538 			nla_b = nla_nest_start(ans_skb, NLBL_CIPSOV4_A_MLSLVL);
539 			if (nla_b == NULL) {
540 				ret_val = -ENOMEM;
541 				goto list_retry;
542 			}
543 			ret_val = nla_put_u32(ans_skb,
544 					      NLBL_CIPSOV4_A_MLSLVLLOC,
545 					      iter);
546 			if (ret_val != 0)
547 				goto list_retry;
548 			ret_val = nla_put_u32(ans_skb,
549 					    NLBL_CIPSOV4_A_MLSLVLREM,
550 					    doi_def->map.std->lvl.local[iter]);
551 			if (ret_val != 0)
552 				goto list_retry;
553 			nla_nest_end(ans_skb, nla_b);
554 		}
555 		nla_nest_end(ans_skb, nla_a);
556 
557 		nla_a = nla_nest_start(ans_skb, NLBL_CIPSOV4_A_MLSCATLST);
558 		if (nla_a == NULL) {
559 			ret_val = -ENOMEM;
560 			goto list_retry;
561 		}
562 		for (iter = 0;
563 		     iter < doi_def->map.std->cat.local_size;
564 		     iter++) {
565 			if (doi_def->map.std->cat.local[iter] ==
566 			    CIPSO_V4_INV_CAT)
567 				continue;
568 
569 			nla_b = nla_nest_start(ans_skb, NLBL_CIPSOV4_A_MLSCAT);
570 			if (nla_b == NULL) {
571 				ret_val = -ENOMEM;
572 				goto list_retry;
573 			}
574 			ret_val = nla_put_u32(ans_skb,
575 					      NLBL_CIPSOV4_A_MLSCATLOC,
576 					      iter);
577 			if (ret_val != 0)
578 				goto list_retry;
579 			ret_val = nla_put_u32(ans_skb,
580 					    NLBL_CIPSOV4_A_MLSCATREM,
581 					    doi_def->map.std->cat.local[iter]);
582 			if (ret_val != 0)
583 				goto list_retry;
584 			nla_nest_end(ans_skb, nla_b);
585 		}
586 		nla_nest_end(ans_skb, nla_a);
587 
588 		break;
589 	}
590 	rcu_read_unlock();
591 
592 	genlmsg_end(ans_skb, data);
593 	return genlmsg_reply(ans_skb, info);
594 
595 list_retry:
596 	/* XXX - this limit is a guesstimate */
597 	if (nlsze_mult < 4) {
598 		rcu_read_unlock();
599 		kfree_skb(ans_skb);
600 		nlsze_mult *= 2;
601 		goto list_start;
602 	}
603 list_failure_lock:
604 	rcu_read_unlock();
605 list_failure:
606 	kfree_skb(ans_skb);
607 	return ret_val;
608 }
609 
610 /**
611  * netlbl_cipsov4_listall_cb - cipso_v4_doi_walk() callback for LISTALL
612  * @doi_def: the CIPSOv4 DOI definition
613  * @arg: the netlbl_cipsov4_doiwalk_arg structure
614  *
615  * Description:
616  * This function is designed to be used as a callback to the
617  * cipso_v4_doi_walk() function for use in generating a response for a LISTALL
618  * message.  Returns the size of the message on success, negative values on
619  * failure.
620  *
621  */
622 static int netlbl_cipsov4_listall_cb(struct cipso_v4_doi *doi_def, void *arg)
623 {
624 	int ret_val = -ENOMEM;
625 	struct netlbl_cipsov4_doiwalk_arg *cb_arg = arg;
626 	void *data;
627 
628 	data = genlmsg_put(cb_arg->skb, NETLINK_CB(cb_arg->nl_cb->skb).portid,
629 			   cb_arg->seq, &netlbl_cipsov4_gnl_family,
630 			   NLM_F_MULTI, NLBL_CIPSOV4_C_LISTALL);
631 	if (data == NULL)
632 		goto listall_cb_failure;
633 
634 	ret_val = nla_put_u32(cb_arg->skb, NLBL_CIPSOV4_A_DOI, doi_def->doi);
635 	if (ret_val != 0)
636 		goto listall_cb_failure;
637 	ret_val = nla_put_u32(cb_arg->skb,
638 			      NLBL_CIPSOV4_A_MTYPE,
639 			      doi_def->type);
640 	if (ret_val != 0)
641 		goto listall_cb_failure;
642 
643 	genlmsg_end(cb_arg->skb, data);
644 	return 0;
645 
646 listall_cb_failure:
647 	genlmsg_cancel(cb_arg->skb, data);
648 	return ret_val;
649 }
650 
651 /**
652  * netlbl_cipsov4_listall - Handle a LISTALL message
653  * @skb: the NETLINK buffer
654  * @cb: the NETLINK callback
655  *
656  * Description:
657  * Process a user generated LISTALL message and respond accordingly.  Returns
658  * zero on success and negative values on error.
659  *
660  */
661 static int netlbl_cipsov4_listall(struct sk_buff *skb,
662 				  struct netlink_callback *cb)
663 {
664 	struct netlbl_cipsov4_doiwalk_arg cb_arg;
665 	u32 doi_skip = cb->args[0];
666 
667 	cb_arg.nl_cb = cb;
668 	cb_arg.skb = skb;
669 	cb_arg.seq = cb->nlh->nlmsg_seq;
670 
671 	cipso_v4_doi_walk(&doi_skip, netlbl_cipsov4_listall_cb, &cb_arg);
672 
673 	cb->args[0] = doi_skip;
674 	return skb->len;
675 }
676 
677 /**
678  * netlbl_cipsov4_remove_cb - netlbl_cipsov4_remove() callback for REMOVE
679  * @entry: LSM domain mapping entry
680  * @arg: the netlbl_domhsh_walk_arg structure
681  *
682  * Description:
683  * This function is intended for use by netlbl_cipsov4_remove() as the callback
684  * for the netlbl_domhsh_walk() function; it removes LSM domain map entries
685  * which are associated with the CIPSO DOI specified in @arg.  Returns zero on
686  * success, negative values on failure.
687  *
688  */
689 static int netlbl_cipsov4_remove_cb(struct netlbl_dom_map *entry, void *arg)
690 {
691 	struct netlbl_domhsh_walk_arg *cb_arg = arg;
692 
693 	if (entry->def.type == NETLBL_NLTYPE_CIPSOV4 &&
694 	    entry->def.cipso->doi == cb_arg->doi)
695 		return netlbl_domhsh_remove_entry(entry, cb_arg->audit_info);
696 
697 	return 0;
698 }
699 
700 /**
701  * netlbl_cipsov4_remove - Handle a REMOVE message
702  * @skb: the NETLINK buffer
703  * @info: the Generic NETLINK info block
704  *
705  * Description:
706  * Process a user generated REMOVE message and respond accordingly.  Returns
707  * zero on success, negative values on failure.
708  *
709  */
710 static int netlbl_cipsov4_remove(struct sk_buff *skb, struct genl_info *info)
711 {
712 	int ret_val = -EINVAL;
713 	struct netlbl_domhsh_walk_arg cb_arg;
714 	struct netlbl_audit audit_info;
715 	u32 skip_bkt = 0;
716 	u32 skip_chain = 0;
717 
718 	if (!info->attrs[NLBL_CIPSOV4_A_DOI])
719 		return -EINVAL;
720 
721 	netlbl_netlink_auditinfo(skb, &audit_info);
722 	cb_arg.doi = nla_get_u32(info->attrs[NLBL_CIPSOV4_A_DOI]);
723 	cb_arg.audit_info = &audit_info;
724 	ret_val = netlbl_domhsh_walk(&skip_bkt, &skip_chain,
725 				     netlbl_cipsov4_remove_cb, &cb_arg);
726 	if (ret_val == 0 || ret_val == -ENOENT) {
727 		ret_val = cipso_v4_doi_remove(cb_arg.doi, &audit_info);
728 		if (ret_val == 0)
729 			atomic_dec(&netlabel_mgmt_protocount);
730 	}
731 
732 	return ret_val;
733 }
734 
735 /*
736  * NetLabel Generic NETLINK Command Definitions
737  */
738 
739 static const struct genl_ops netlbl_cipsov4_ops[] = {
740 	{
741 	.cmd = NLBL_CIPSOV4_C_ADD,
742 	.flags = GENL_ADMIN_PERM,
743 	.policy = netlbl_cipsov4_genl_policy,
744 	.doit = netlbl_cipsov4_add,
745 	.dumpit = NULL,
746 	},
747 	{
748 	.cmd = NLBL_CIPSOV4_C_REMOVE,
749 	.flags = GENL_ADMIN_PERM,
750 	.policy = netlbl_cipsov4_genl_policy,
751 	.doit = netlbl_cipsov4_remove,
752 	.dumpit = NULL,
753 	},
754 	{
755 	.cmd = NLBL_CIPSOV4_C_LIST,
756 	.flags = 0,
757 	.policy = netlbl_cipsov4_genl_policy,
758 	.doit = netlbl_cipsov4_list,
759 	.dumpit = NULL,
760 	},
761 	{
762 	.cmd = NLBL_CIPSOV4_C_LISTALL,
763 	.flags = 0,
764 	.policy = netlbl_cipsov4_genl_policy,
765 	.doit = NULL,
766 	.dumpit = netlbl_cipsov4_listall,
767 	},
768 };
769 
770 /*
771  * NetLabel Generic NETLINK Protocol Functions
772  */
773 
774 /**
775  * netlbl_cipsov4_genl_init - Register the CIPSOv4 NetLabel component
776  *
777  * Description:
778  * Register the CIPSOv4 packet NetLabel component with the Generic NETLINK
779  * mechanism.  Returns zero on success, negative values on failure.
780  *
781  */
782 int __init netlbl_cipsov4_genl_init(void)
783 {
784 	return genl_register_family_with_ops(&netlbl_cipsov4_gnl_family,
785 					     netlbl_cipsov4_ops);
786 }
787