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.moore@hp.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, write to the Free Software
27  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
28  *
29  */
30 
31 #include <linux/types.h>
32 #include <linux/socket.h>
33 #include <linux/string.h>
34 #include <linux/skbuff.h>
35 #include <linux/audit.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 
42 #include "netlabel_user.h"
43 #include "netlabel_cipso_v4.h"
44 
45 /* Argument struct for cipso_v4_doi_walk() */
46 struct netlbl_cipsov4_doiwalk_arg {
47 	struct netlink_callback *nl_cb;
48 	struct sk_buff *skb;
49 	u32 seq;
50 };
51 
52 /* NetLabel Generic NETLINK CIPSOv4 family */
53 static struct genl_family netlbl_cipsov4_gnl_family = {
54 	.id = GENL_ID_GENERATE,
55 	.hdrsize = 0,
56 	.name = NETLBL_NLTYPE_CIPSOV4_NAME,
57 	.version = NETLBL_PROTO_VERSION,
58 	.maxattr = NLBL_CIPSOV4_A_MAX,
59 };
60 
61 /* NetLabel Netlink attribute policy */
62 static const struct nla_policy netlbl_cipsov4_genl_policy[NLBL_CIPSOV4_A_MAX + 1] = {
63 	[NLBL_CIPSOV4_A_DOI] = { .type = NLA_U32 },
64 	[NLBL_CIPSOV4_A_MTYPE] = { .type = NLA_U32 },
65 	[NLBL_CIPSOV4_A_TAG] = { .type = NLA_U8 },
66 	[NLBL_CIPSOV4_A_TAGLST] = { .type = NLA_NESTED },
67 	[NLBL_CIPSOV4_A_MLSLVLLOC] = { .type = NLA_U32 },
68 	[NLBL_CIPSOV4_A_MLSLVLREM] = { .type = NLA_U32 },
69 	[NLBL_CIPSOV4_A_MLSLVL] = { .type = NLA_NESTED },
70 	[NLBL_CIPSOV4_A_MLSLVLLST] = { .type = NLA_NESTED },
71 	[NLBL_CIPSOV4_A_MLSCATLOC] = { .type = NLA_U32 },
72 	[NLBL_CIPSOV4_A_MLSCATREM] = { .type = NLA_U32 },
73 	[NLBL_CIPSOV4_A_MLSCAT] = { .type = NLA_NESTED },
74 	[NLBL_CIPSOV4_A_MLSCATLST] = { .type = NLA_NESTED },
75 };
76 
77 /*
78  * Helper Functions
79  */
80 
81 /**
82  * netlbl_cipsov4_doi_free - Frees a CIPSO V4 DOI definition
83  * @entry: the entry's RCU field
84  *
85  * Description:
86  * This function is designed to be used as a callback to the call_rcu()
87  * function so that the memory allocated to the DOI definition can be released
88  * safely.
89  *
90  */
91 static void netlbl_cipsov4_doi_free(struct rcu_head *entry)
92 {
93 	struct cipso_v4_doi *ptr;
94 
95 	ptr = container_of(entry, struct cipso_v4_doi, rcu);
96 	switch (ptr->type) {
97 	case CIPSO_V4_MAP_STD:
98 		kfree(ptr->map.std->lvl.cipso);
99 		kfree(ptr->map.std->lvl.local);
100 		kfree(ptr->map.std->cat.cipso);
101 		kfree(ptr->map.std->cat.local);
102 		break;
103 	}
104 	kfree(ptr);
105 }
106 
107 /**
108  * netlbl_cipsov4_add_common - Parse the common sections of a ADD message
109  * @info: the Generic NETLINK info block
110  * @doi_def: the CIPSO V4 DOI definition
111  *
112  * Description:
113  * Parse the common sections of a ADD message and fill in the related values
114  * in @doi_def.  Returns zero on success, negative values on failure.
115  *
116  */
117 static int netlbl_cipsov4_add_common(struct genl_info *info,
118 				     struct cipso_v4_doi *doi_def)
119 {
120 	struct nlattr *nla;
121 	int nla_rem;
122 	u32 iter = 0;
123 
124 	doi_def->doi = nla_get_u32(info->attrs[NLBL_CIPSOV4_A_DOI]);
125 
126 	if (nla_validate_nested(info->attrs[NLBL_CIPSOV4_A_TAGLST],
127 				NLBL_CIPSOV4_A_MAX,
128 				netlbl_cipsov4_genl_policy) != 0)
129 		return -EINVAL;
130 
131 	nla_for_each_nested(nla, info->attrs[NLBL_CIPSOV4_A_TAGLST], nla_rem)
132 		if (nla->nla_type == NLBL_CIPSOV4_A_TAG) {
133 			if (iter >= CIPSO_V4_TAG_MAXCNT)
134 				return -EINVAL;
135 			doi_def->tags[iter++] = nla_get_u8(nla);
136 		}
137 	while (iter < CIPSO_V4_TAG_MAXCNT)
138 		doi_def->tags[iter++] = CIPSO_V4_TAG_INVALID;
139 
140 	return 0;
141 }
142 
143 /*
144  * NetLabel Command Handlers
145  */
146 
147 /**
148  * netlbl_cipsov4_add_std - Adds a CIPSO V4 DOI definition
149  * @info: the Generic NETLINK info block
150  *
151  * Description:
152  * Create a new CIPSO_V4_MAP_STD DOI definition based on the given ADD message
153  * and add it to the CIPSO V4 engine.  Return zero on success and non-zero on
154  * error.
155  *
156  */
157 static int netlbl_cipsov4_add_std(struct genl_info *info)
158 {
159 	int ret_val = -EINVAL;
160 	struct cipso_v4_doi *doi_def = NULL;
161 	struct nlattr *nla_a;
162 	struct nlattr *nla_b;
163 	int nla_a_rem;
164 	int nla_b_rem;
165 	u32 iter;
166 
167 	if (!info->attrs[NLBL_CIPSOV4_A_TAGLST] ||
168 	    !info->attrs[NLBL_CIPSOV4_A_MLSLVLLST])
169 		return -EINVAL;
170 
171 	if (nla_validate_nested(info->attrs[NLBL_CIPSOV4_A_MLSLVLLST],
172 				NLBL_CIPSOV4_A_MAX,
173 				netlbl_cipsov4_genl_policy) != 0)
174 		return -EINVAL;
175 
176 	doi_def = kmalloc(sizeof(*doi_def), GFP_KERNEL);
177 	if (doi_def == NULL)
178 		return -ENOMEM;
179 	doi_def->map.std = kzalloc(sizeof(*doi_def->map.std), GFP_KERNEL);
180 	if (doi_def->map.std == NULL) {
181 		ret_val = -ENOMEM;
182 		goto add_std_failure;
183 	}
184 	doi_def->type = CIPSO_V4_MAP_STD;
185 
186 	ret_val = netlbl_cipsov4_add_common(info, doi_def);
187 	if (ret_val != 0)
188 		goto add_std_failure;
189 	ret_val = -EINVAL;
190 
191 	nla_for_each_nested(nla_a,
192 			    info->attrs[NLBL_CIPSOV4_A_MLSLVLLST],
193 			    nla_a_rem)
194 		if (nla_a->nla_type == NLBL_CIPSOV4_A_MLSLVL) {
195 			if (nla_validate_nested(nla_a,
196 					    NLBL_CIPSOV4_A_MAX,
197 					    netlbl_cipsov4_genl_policy) != 0)
198 					goto add_std_failure;
199 			nla_for_each_nested(nla_b, nla_a, nla_b_rem)
200 				switch (nla_b->nla_type) {
201 				case NLBL_CIPSOV4_A_MLSLVLLOC:
202 					if (nla_get_u32(nla_b) >
203 					    CIPSO_V4_MAX_LOC_LVLS)
204 						goto add_std_failure;
205 					if (nla_get_u32(nla_b) >=
206 					    doi_def->map.std->lvl.local_size)
207 					     doi_def->map.std->lvl.local_size =
208 						     nla_get_u32(nla_b) + 1;
209 					break;
210 				case NLBL_CIPSOV4_A_MLSLVLREM:
211 					if (nla_get_u32(nla_b) >
212 					    CIPSO_V4_MAX_REM_LVLS)
213 						goto add_std_failure;
214 					if (nla_get_u32(nla_b) >=
215 					    doi_def->map.std->lvl.cipso_size)
216 					     doi_def->map.std->lvl.cipso_size =
217 						     nla_get_u32(nla_b) + 1;
218 					break;
219 				}
220 		}
221 	doi_def->map.std->lvl.local = kcalloc(doi_def->map.std->lvl.local_size,
222 					      sizeof(u32),
223 					      GFP_KERNEL);
224 	if (doi_def->map.std->lvl.local == NULL) {
225 		ret_val = -ENOMEM;
226 		goto add_std_failure;
227 	}
228 	doi_def->map.std->lvl.cipso = kcalloc(doi_def->map.std->lvl.cipso_size,
229 					      sizeof(u32),
230 					      GFP_KERNEL);
231 	if (doi_def->map.std->lvl.cipso == NULL) {
232 		ret_val = -ENOMEM;
233 		goto add_std_failure;
234 	}
235 	for (iter = 0; iter < doi_def->map.std->lvl.local_size; iter++)
236 		doi_def->map.std->lvl.local[iter] = CIPSO_V4_INV_LVL;
237 	for (iter = 0; iter < doi_def->map.std->lvl.cipso_size; iter++)
238 		doi_def->map.std->lvl.cipso[iter] = CIPSO_V4_INV_LVL;
239 	nla_for_each_nested(nla_a,
240 			    info->attrs[NLBL_CIPSOV4_A_MLSLVLLST],
241 			    nla_a_rem)
242 		if (nla_a->nla_type == NLBL_CIPSOV4_A_MLSLVL) {
243 			struct nlattr *lvl_loc;
244 			struct nlattr *lvl_rem;
245 
246 			lvl_loc = nla_find_nested(nla_a,
247 						  NLBL_CIPSOV4_A_MLSLVLLOC);
248 			lvl_rem = nla_find_nested(nla_a,
249 						  NLBL_CIPSOV4_A_MLSLVLREM);
250 			if (lvl_loc == NULL || lvl_rem == NULL)
251 				goto add_std_failure;
252 			doi_def->map.std->lvl.local[nla_get_u32(lvl_loc)] =
253 				nla_get_u32(lvl_rem);
254 			doi_def->map.std->lvl.cipso[nla_get_u32(lvl_rem)] =
255 				nla_get_u32(lvl_loc);
256 		}
257 
258 	if (info->attrs[NLBL_CIPSOV4_A_MLSCATLST]) {
259 		if (nla_validate_nested(info->attrs[NLBL_CIPSOV4_A_MLSCATLST],
260 					NLBL_CIPSOV4_A_MAX,
261 					netlbl_cipsov4_genl_policy) != 0)
262 			goto add_std_failure;
263 
264 		nla_for_each_nested(nla_a,
265 				    info->attrs[NLBL_CIPSOV4_A_MLSCATLST],
266 				    nla_a_rem)
267 			if (nla_a->nla_type == NLBL_CIPSOV4_A_MLSCAT) {
268 				if (nla_validate_nested(nla_a,
269 					      NLBL_CIPSOV4_A_MAX,
270 					      netlbl_cipsov4_genl_policy) != 0)
271 					goto add_std_failure;
272 				nla_for_each_nested(nla_b, nla_a, nla_b_rem)
273 					switch (nla_b->nla_type) {
274 					case NLBL_CIPSOV4_A_MLSCATLOC:
275 						if (nla_get_u32(nla_b) >
276 						    CIPSO_V4_MAX_LOC_CATS)
277 							goto add_std_failure;
278 						if (nla_get_u32(nla_b) >=
279 					      doi_def->map.std->cat.local_size)
280 					     doi_def->map.std->cat.local_size =
281 						     nla_get_u32(nla_b) + 1;
282 						break;
283 					case NLBL_CIPSOV4_A_MLSCATREM:
284 						if (nla_get_u32(nla_b) >
285 						    CIPSO_V4_MAX_REM_CATS)
286 							goto add_std_failure;
287 						if (nla_get_u32(nla_b) >=
288 					      doi_def->map.std->cat.cipso_size)
289 					     doi_def->map.std->cat.cipso_size =
290 						     nla_get_u32(nla_b) + 1;
291 						break;
292 					}
293 			}
294 		doi_def->map.std->cat.local = kcalloc(
295 					      doi_def->map.std->cat.local_size,
296 					      sizeof(u32),
297 					      GFP_KERNEL);
298 		if (doi_def->map.std->cat.local == NULL) {
299 			ret_val = -ENOMEM;
300 			goto add_std_failure;
301 		}
302 		doi_def->map.std->cat.cipso = kcalloc(
303 					      doi_def->map.std->cat.cipso_size,
304 					      sizeof(u32),
305 					      GFP_KERNEL);
306 		if (doi_def->map.std->cat.cipso == NULL) {
307 			ret_val = -ENOMEM;
308 			goto add_std_failure;
309 		}
310 		for (iter = 0; iter < doi_def->map.std->cat.local_size; iter++)
311 			doi_def->map.std->cat.local[iter] = CIPSO_V4_INV_CAT;
312 		for (iter = 0; iter < doi_def->map.std->cat.cipso_size; iter++)
313 			doi_def->map.std->cat.cipso[iter] = CIPSO_V4_INV_CAT;
314 		nla_for_each_nested(nla_a,
315 				    info->attrs[NLBL_CIPSOV4_A_MLSCATLST],
316 				    nla_a_rem)
317 			if (nla_a->nla_type == NLBL_CIPSOV4_A_MLSCAT) {
318 				struct nlattr *cat_loc;
319 				struct nlattr *cat_rem;
320 
321 				cat_loc = nla_find_nested(nla_a,
322 						     NLBL_CIPSOV4_A_MLSCATLOC);
323 				cat_rem = nla_find_nested(nla_a,
324 						     NLBL_CIPSOV4_A_MLSCATREM);
325 				if (cat_loc == NULL || cat_rem == NULL)
326 					goto add_std_failure;
327 				doi_def->map.std->cat.local[
328 							nla_get_u32(cat_loc)] =
329 					nla_get_u32(cat_rem);
330 				doi_def->map.std->cat.cipso[
331 							nla_get_u32(cat_rem)] =
332 					nla_get_u32(cat_loc);
333 			}
334 	}
335 
336 	ret_val = cipso_v4_doi_add(doi_def);
337 	if (ret_val != 0)
338 		goto add_std_failure;
339 	return 0;
340 
341 add_std_failure:
342 	if (doi_def)
343 		netlbl_cipsov4_doi_free(&doi_def->rcu);
344 	return ret_val;
345 }
346 
347 /**
348  * netlbl_cipsov4_add_pass - Adds a CIPSO V4 DOI definition
349  * @info: the Generic NETLINK info block
350  *
351  * Description:
352  * Create a new CIPSO_V4_MAP_PASS DOI definition based on the given ADD message
353  * and add it to the CIPSO V4 engine.  Return zero on success and non-zero on
354  * error.
355  *
356  */
357 static int netlbl_cipsov4_add_pass(struct genl_info *info)
358 {
359 	int ret_val;
360 	struct cipso_v4_doi *doi_def = NULL;
361 
362 	if (!info->attrs[NLBL_CIPSOV4_A_TAGLST])
363 		return -EINVAL;
364 
365 	doi_def = kmalloc(sizeof(*doi_def), GFP_KERNEL);
366 	if (doi_def == NULL)
367 		return -ENOMEM;
368 	doi_def->type = CIPSO_V4_MAP_PASS;
369 
370 	ret_val = netlbl_cipsov4_add_common(info, doi_def);
371 	if (ret_val != 0)
372 		goto add_pass_failure;
373 
374 	ret_val = cipso_v4_doi_add(doi_def);
375 	if (ret_val != 0)
376 		goto add_pass_failure;
377 	return 0;
378 
379 add_pass_failure:
380 	netlbl_cipsov4_doi_free(&doi_def->rcu);
381 	return ret_val;
382 }
383 
384 /**
385  * netlbl_cipsov4_add - Handle an ADD message
386  * @skb: the NETLINK buffer
387  * @info: the Generic NETLINK info block
388  *
389  * Description:
390  * Create a new DOI definition based on the given ADD message and add it to the
391  * CIPSO V4 engine.  Returns zero on success, negative values on failure.
392  *
393  */
394 static int netlbl_cipsov4_add(struct sk_buff *skb, struct genl_info *info)
395 
396 {
397 	int ret_val = -EINVAL;
398 	u32 type;
399 	u32 doi;
400 	const char *type_str = "(unknown)";
401 	struct audit_buffer *audit_buf;
402 	struct netlbl_audit audit_info;
403 
404 	if (!info->attrs[NLBL_CIPSOV4_A_DOI] ||
405 	    !info->attrs[NLBL_CIPSOV4_A_MTYPE])
406 		return -EINVAL;
407 
408 	doi = nla_get_u32(info->attrs[NLBL_CIPSOV4_A_DOI]);
409 	netlbl_netlink_auditinfo(skb, &audit_info);
410 
411 	type = nla_get_u32(info->attrs[NLBL_CIPSOV4_A_MTYPE]);
412 	switch (type) {
413 	case CIPSO_V4_MAP_STD:
414 		type_str = "std";
415 		ret_val = netlbl_cipsov4_add_std(info);
416 		break;
417 	case CIPSO_V4_MAP_PASS:
418 		type_str = "pass";
419 		ret_val = netlbl_cipsov4_add_pass(info);
420 		break;
421 	}
422 
423 	audit_buf = netlbl_audit_start_common(AUDIT_MAC_CIPSOV4_ADD,
424 					      &audit_info);
425 	if (audit_buf != NULL) {
426 		audit_log_format(audit_buf,
427 				 " cipso_doi=%u cipso_type=%s res=%u",
428 				 doi,
429 				 type_str,
430 				 ret_val == 0 ? 1 : 0);
431 		audit_log_end(audit_buf);
432 	}
433 
434 	return ret_val;
435 }
436 
437 /**
438  * netlbl_cipsov4_list - Handle a LIST message
439  * @skb: the NETLINK buffer
440  * @info: the Generic NETLINK info block
441  *
442  * Description:
443  * Process a user generated LIST message and respond accordingly.  While the
444  * response message generated by the kernel is straightforward, determining
445  * before hand the size of the buffer to allocate is not (we have to generate
446  * the message to know the size).  In order to keep this function sane what we
447  * do is allocate a buffer of NLMSG_GOODSIZE and try to fit the response in
448  * that size, if we fail then we restart with a larger buffer and try again.
449  * We continue in this manner until we hit a limit of failed attempts then we
450  * give up and just send an error message.  Returns zero on success and
451  * negative values on error.
452  *
453  */
454 static int netlbl_cipsov4_list(struct sk_buff *skb, struct genl_info *info)
455 {
456 	int ret_val;
457 	struct sk_buff *ans_skb = NULL;
458 	u32 nlsze_mult = 1;
459 	void *data;
460 	u32 doi;
461 	struct nlattr *nla_a;
462 	struct nlattr *nla_b;
463 	struct cipso_v4_doi *doi_def;
464 	u32 iter;
465 
466 	if (!info->attrs[NLBL_CIPSOV4_A_DOI]) {
467 		ret_val = -EINVAL;
468 		goto list_failure;
469 	}
470 
471 list_start:
472 	ans_skb = nlmsg_new(NLMSG_DEFAULT_SIZE * nlsze_mult, GFP_KERNEL);
473 	if (ans_skb == NULL) {
474 		ret_val = -ENOMEM;
475 		goto list_failure;
476 	}
477 	data = genlmsg_put_reply(ans_skb, info, &netlbl_cipsov4_gnl_family,
478 				 0, NLBL_CIPSOV4_C_LIST);
479 	if (data == NULL) {
480 		ret_val = -ENOMEM;
481 		goto list_failure;
482 	}
483 
484 	doi = nla_get_u32(info->attrs[NLBL_CIPSOV4_A_DOI]);
485 
486 	rcu_read_lock();
487 	doi_def = cipso_v4_doi_getdef(doi);
488 	if (doi_def == NULL) {
489 		ret_val = -EINVAL;
490 		goto list_failure;
491 	}
492 
493 	ret_val = nla_put_u32(ans_skb, NLBL_CIPSOV4_A_MTYPE, doi_def->type);
494 	if (ret_val != 0)
495 		goto list_failure_lock;
496 
497 	nla_a = nla_nest_start(ans_skb, NLBL_CIPSOV4_A_TAGLST);
498 	if (nla_a == NULL) {
499 		ret_val = -ENOMEM;
500 		goto list_failure_lock;
501 	}
502 	for (iter = 0;
503 	     iter < CIPSO_V4_TAG_MAXCNT &&
504 	       doi_def->tags[iter] != CIPSO_V4_TAG_INVALID;
505 	     iter++) {
506 		ret_val = nla_put_u8(ans_skb,
507 				     NLBL_CIPSOV4_A_TAG,
508 				     doi_def->tags[iter]);
509 		if (ret_val != 0)
510 			goto list_failure_lock;
511 	}
512 	nla_nest_end(ans_skb, nla_a);
513 
514 	switch (doi_def->type) {
515 	case CIPSO_V4_MAP_STD:
516 		nla_a = nla_nest_start(ans_skb, NLBL_CIPSOV4_A_MLSLVLLST);
517 		if (nla_a == NULL) {
518 			ret_val = -ENOMEM;
519 			goto list_failure_lock;
520 		}
521 		for (iter = 0;
522 		     iter < doi_def->map.std->lvl.local_size;
523 		     iter++) {
524 			if (doi_def->map.std->lvl.local[iter] ==
525 			    CIPSO_V4_INV_LVL)
526 				continue;
527 
528 			nla_b = nla_nest_start(ans_skb, NLBL_CIPSOV4_A_MLSLVL);
529 			if (nla_b == NULL) {
530 				ret_val = -ENOMEM;
531 				goto list_retry;
532 			}
533 			ret_val = nla_put_u32(ans_skb,
534 					      NLBL_CIPSOV4_A_MLSLVLLOC,
535 					      iter);
536 			if (ret_val != 0)
537 				goto list_retry;
538 			ret_val = nla_put_u32(ans_skb,
539 					    NLBL_CIPSOV4_A_MLSLVLREM,
540 					    doi_def->map.std->lvl.local[iter]);
541 			if (ret_val != 0)
542 				goto list_retry;
543 			nla_nest_end(ans_skb, nla_b);
544 		}
545 		nla_nest_end(ans_skb, nla_a);
546 
547 		nla_a = nla_nest_start(ans_skb, NLBL_CIPSOV4_A_MLSCATLST);
548 		if (nla_a == NULL) {
549 			ret_val = -ENOMEM;
550 			goto list_retry;
551 		}
552 		for (iter = 0;
553 		     iter < doi_def->map.std->cat.local_size;
554 		     iter++) {
555 			if (doi_def->map.std->cat.local[iter] ==
556 			    CIPSO_V4_INV_CAT)
557 				continue;
558 
559 			nla_b = nla_nest_start(ans_skb, NLBL_CIPSOV4_A_MLSCAT);
560 			if (nla_b == NULL) {
561 				ret_val = -ENOMEM;
562 				goto list_retry;
563 			}
564 			ret_val = nla_put_u32(ans_skb,
565 					      NLBL_CIPSOV4_A_MLSCATLOC,
566 					      iter);
567 			if (ret_val != 0)
568 				goto list_retry;
569 			ret_val = nla_put_u32(ans_skb,
570 					    NLBL_CIPSOV4_A_MLSCATREM,
571 					    doi_def->map.std->cat.local[iter]);
572 			if (ret_val != 0)
573 				goto list_retry;
574 			nla_nest_end(ans_skb, nla_b);
575 		}
576 		nla_nest_end(ans_skb, nla_a);
577 
578 		break;
579 	}
580 	rcu_read_unlock();
581 
582 	genlmsg_end(ans_skb, data);
583 
584 	ret_val = genlmsg_reply(ans_skb, info);
585 	if (ret_val != 0)
586 		goto list_failure;
587 
588 	return 0;
589 
590 list_retry:
591 	/* XXX - this limit is a guesstimate */
592 	if (nlsze_mult < 4) {
593 		rcu_read_unlock();
594 		kfree_skb(ans_skb);
595 		nlsze_mult++;
596 		goto list_start;
597 	}
598 list_failure_lock:
599 	rcu_read_unlock();
600 list_failure:
601 	kfree_skb(ans_skb);
602 	return ret_val;
603 }
604 
605 /**
606  * netlbl_cipsov4_listall_cb - cipso_v4_doi_walk() callback for LISTALL
607  * @doi_def: the CIPSOv4 DOI definition
608  * @arg: the netlbl_cipsov4_doiwalk_arg structure
609  *
610  * Description:
611  * This function is designed to be used as a callback to the
612  * cipso_v4_doi_walk() function for use in generating a response for a LISTALL
613  * message.  Returns the size of the message on success, negative values on
614  * failure.
615  *
616  */
617 static int netlbl_cipsov4_listall_cb(struct cipso_v4_doi *doi_def, void *arg)
618 {
619 	int ret_val = -ENOMEM;
620 	struct netlbl_cipsov4_doiwalk_arg *cb_arg = arg;
621 	void *data;
622 
623 	data = genlmsg_put(cb_arg->skb, NETLINK_CB(cb_arg->nl_cb->skb).pid,
624 			   cb_arg->seq, &netlbl_cipsov4_gnl_family,
625 			   NLM_F_MULTI, NLBL_CIPSOV4_C_LISTALL);
626 	if (data == NULL)
627 		goto listall_cb_failure;
628 
629 	ret_val = nla_put_u32(cb_arg->skb, NLBL_CIPSOV4_A_DOI, doi_def->doi);
630 	if (ret_val != 0)
631 		goto listall_cb_failure;
632 	ret_val = nla_put_u32(cb_arg->skb,
633 			      NLBL_CIPSOV4_A_MTYPE,
634 			      doi_def->type);
635 	if (ret_val != 0)
636 		goto listall_cb_failure;
637 
638 	return genlmsg_end(cb_arg->skb, data);
639 
640 listall_cb_failure:
641 	genlmsg_cancel(cb_arg->skb, data);
642 	return ret_val;
643 }
644 
645 /**
646  * netlbl_cipsov4_listall - Handle a LISTALL message
647  * @skb: the NETLINK buffer
648  * @cb: the NETLINK callback
649  *
650  * Description:
651  * Process a user generated LISTALL message and respond accordingly.  Returns
652  * zero on success and negative values on error.
653  *
654  */
655 static int netlbl_cipsov4_listall(struct sk_buff *skb,
656 				  struct netlink_callback *cb)
657 {
658 	struct netlbl_cipsov4_doiwalk_arg cb_arg;
659 	int doi_skip = cb->args[0];
660 
661 	cb_arg.nl_cb = cb;
662 	cb_arg.skb = skb;
663 	cb_arg.seq = cb->nlh->nlmsg_seq;
664 
665 	cipso_v4_doi_walk(&doi_skip, netlbl_cipsov4_listall_cb, &cb_arg);
666 
667 	cb->args[0] = doi_skip;
668 	return skb->len;
669 }
670 
671 /**
672  * netlbl_cipsov4_remove - Handle a REMOVE message
673  * @skb: the NETLINK buffer
674  * @info: the Generic NETLINK info block
675  *
676  * Description:
677  * Process a user generated REMOVE message and respond accordingly.  Returns
678  * zero on success, negative values on failure.
679  *
680  */
681 static int netlbl_cipsov4_remove(struct sk_buff *skb, struct genl_info *info)
682 {
683 	int ret_val = -EINVAL;
684 	u32 doi = 0;
685 	struct audit_buffer *audit_buf;
686 	struct netlbl_audit audit_info;
687 
688 	if (!info->attrs[NLBL_CIPSOV4_A_DOI])
689 		return -EINVAL;
690 
691 	doi = nla_get_u32(info->attrs[NLBL_CIPSOV4_A_DOI]);
692 	netlbl_netlink_auditinfo(skb, &audit_info);
693 
694 	ret_val = cipso_v4_doi_remove(doi,
695 				      &audit_info,
696 				      netlbl_cipsov4_doi_free);
697 
698 	audit_buf = netlbl_audit_start_common(AUDIT_MAC_CIPSOV4_DEL,
699 					      &audit_info);
700 	if (audit_buf != NULL) {
701 		audit_log_format(audit_buf,
702 				 " cipso_doi=%u res=%u",
703 				 doi,
704 				 ret_val == 0 ? 1 : 0);
705 		audit_log_end(audit_buf);
706 	}
707 
708 	return ret_val;
709 }
710 
711 /*
712  * NetLabel Generic NETLINK Command Definitions
713  */
714 
715 static struct genl_ops netlbl_cipsov4_genl_c_add = {
716 	.cmd = NLBL_CIPSOV4_C_ADD,
717 	.flags = GENL_ADMIN_PERM,
718 	.policy = netlbl_cipsov4_genl_policy,
719 	.doit = netlbl_cipsov4_add,
720 	.dumpit = NULL,
721 };
722 
723 static struct genl_ops netlbl_cipsov4_genl_c_remove = {
724 	.cmd = NLBL_CIPSOV4_C_REMOVE,
725 	.flags = GENL_ADMIN_PERM,
726 	.policy = netlbl_cipsov4_genl_policy,
727 	.doit = netlbl_cipsov4_remove,
728 	.dumpit = NULL,
729 };
730 
731 static struct genl_ops netlbl_cipsov4_genl_c_list = {
732 	.cmd = NLBL_CIPSOV4_C_LIST,
733 	.flags = 0,
734 	.policy = netlbl_cipsov4_genl_policy,
735 	.doit = netlbl_cipsov4_list,
736 	.dumpit = NULL,
737 };
738 
739 static struct genl_ops netlbl_cipsov4_genl_c_listall = {
740 	.cmd = NLBL_CIPSOV4_C_LISTALL,
741 	.flags = 0,
742 	.policy = netlbl_cipsov4_genl_policy,
743 	.doit = NULL,
744 	.dumpit = netlbl_cipsov4_listall,
745 };
746 
747 /*
748  * NetLabel Generic NETLINK Protocol Functions
749  */
750 
751 /**
752  * netlbl_cipsov4_genl_init - Register the CIPSOv4 NetLabel component
753  *
754  * Description:
755  * Register the CIPSOv4 packet NetLabel component with the Generic NETLINK
756  * mechanism.  Returns zero on success, negative values on failure.
757  *
758  */
759 int netlbl_cipsov4_genl_init(void)
760 {
761 	int ret_val;
762 
763 	ret_val = genl_register_family(&netlbl_cipsov4_gnl_family);
764 	if (ret_val != 0)
765 		return ret_val;
766 
767 	ret_val = genl_register_ops(&netlbl_cipsov4_gnl_family,
768 				    &netlbl_cipsov4_genl_c_add);
769 	if (ret_val != 0)
770 		return ret_val;
771 	ret_val = genl_register_ops(&netlbl_cipsov4_gnl_family,
772 				    &netlbl_cipsov4_genl_c_remove);
773 	if (ret_val != 0)
774 		return ret_val;
775 	ret_val = genl_register_ops(&netlbl_cipsov4_gnl_family,
776 				    &netlbl_cipsov4_genl_c_list);
777 	if (ret_val != 0)
778 		return ret_val;
779 	ret_val = genl_register_ops(&netlbl_cipsov4_gnl_family,
780 				    &netlbl_cipsov4_genl_c_listall);
781 	if (ret_val != 0)
782 		return ret_val;
783 
784 	return 0;
785 }
786