xref: /openbmc/linux/net/netlabel/netlabel_mgmt.c (revision a2cce7a9)
1 /*
2  * NetLabel Management Support
3  *
4  * This file defines the management 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, 2008
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/in.h>
35 #include <linux/in6.h>
36 #include <linux/slab.h>
37 #include <net/sock.h>
38 #include <net/netlink.h>
39 #include <net/genetlink.h>
40 #include <net/ip.h>
41 #include <net/ipv6.h>
42 #include <net/netlabel.h>
43 #include <net/cipso_ipv4.h>
44 #include <linux/atomic.h>
45 
46 #include "netlabel_domainhash.h"
47 #include "netlabel_user.h"
48 #include "netlabel_mgmt.h"
49 
50 /* NetLabel configured protocol counter */
51 atomic_t netlabel_mgmt_protocount = ATOMIC_INIT(0);
52 
53 /* Argument struct for netlbl_domhsh_walk() */
54 struct netlbl_domhsh_walk_arg {
55 	struct netlink_callback *nl_cb;
56 	struct sk_buff *skb;
57 	u32 seq;
58 };
59 
60 /* NetLabel Generic NETLINK CIPSOv4 family */
61 static struct genl_family netlbl_mgmt_gnl_family = {
62 	.id = GENL_ID_GENERATE,
63 	.hdrsize = 0,
64 	.name = NETLBL_NLTYPE_MGMT_NAME,
65 	.version = NETLBL_PROTO_VERSION,
66 	.maxattr = NLBL_MGMT_A_MAX,
67 };
68 
69 /* NetLabel Netlink attribute policy */
70 static const struct nla_policy netlbl_mgmt_genl_policy[NLBL_MGMT_A_MAX + 1] = {
71 	[NLBL_MGMT_A_DOMAIN] = { .type = NLA_NUL_STRING },
72 	[NLBL_MGMT_A_PROTOCOL] = { .type = NLA_U32 },
73 	[NLBL_MGMT_A_VERSION] = { .type = NLA_U32 },
74 	[NLBL_MGMT_A_CV4DOI] = { .type = NLA_U32 },
75 };
76 
77 /*
78  * Helper Functions
79  */
80 
81 /**
82  * netlbl_mgmt_add - Handle an ADD message
83  * @info: the Generic NETLINK info block
84  * @audit_info: NetLabel audit information
85  *
86  * Description:
87  * Helper function for the ADD and ADDDEF messages to add the domain mappings
88  * from the message to the hash table.  See netlabel.h for a description of the
89  * message format.  Returns zero on success, negative values on failure.
90  *
91  */
92 static int netlbl_mgmt_add_common(struct genl_info *info,
93 				  struct netlbl_audit *audit_info)
94 {
95 	int ret_val = -EINVAL;
96 	struct netlbl_domaddr_map *addrmap = NULL;
97 	struct cipso_v4_doi *cipsov4 = NULL;
98 	u32 tmp_val;
99 	struct netlbl_dom_map *entry = kzalloc(sizeof(*entry), GFP_KERNEL);
100 
101 	if (!entry)
102 		return -ENOMEM;
103 	entry->def.type = nla_get_u32(info->attrs[NLBL_MGMT_A_PROTOCOL]);
104 	if (info->attrs[NLBL_MGMT_A_DOMAIN]) {
105 		size_t tmp_size = nla_len(info->attrs[NLBL_MGMT_A_DOMAIN]);
106 		entry->domain = kmalloc(tmp_size, GFP_KERNEL);
107 		if (entry->domain == NULL) {
108 			ret_val = -ENOMEM;
109 			goto add_free_entry;
110 		}
111 		nla_strlcpy(entry->domain,
112 			    info->attrs[NLBL_MGMT_A_DOMAIN], tmp_size);
113 	}
114 
115 	/* NOTE: internally we allow/use a entry->def.type value of
116 	 *       NETLBL_NLTYPE_ADDRSELECT but we don't currently allow users
117 	 *       to pass that as a protocol value because we need to know the
118 	 *       "real" protocol */
119 
120 	switch (entry->def.type) {
121 	case NETLBL_NLTYPE_UNLABELED:
122 		break;
123 	case NETLBL_NLTYPE_CIPSOV4:
124 		if (!info->attrs[NLBL_MGMT_A_CV4DOI])
125 			goto add_free_domain;
126 
127 		tmp_val = nla_get_u32(info->attrs[NLBL_MGMT_A_CV4DOI]);
128 		cipsov4 = cipso_v4_doi_getdef(tmp_val);
129 		if (cipsov4 == NULL)
130 			goto add_free_domain;
131 		entry->def.cipso = cipsov4;
132 		break;
133 	default:
134 		goto add_free_domain;
135 	}
136 
137 	if (info->attrs[NLBL_MGMT_A_IPV4ADDR]) {
138 		struct in_addr *addr;
139 		struct in_addr *mask;
140 		struct netlbl_domaddr4_map *map;
141 
142 		addrmap = kzalloc(sizeof(*addrmap), GFP_KERNEL);
143 		if (addrmap == NULL) {
144 			ret_val = -ENOMEM;
145 			goto add_doi_put_def;
146 		}
147 		INIT_LIST_HEAD(&addrmap->list4);
148 		INIT_LIST_HEAD(&addrmap->list6);
149 
150 		if (nla_len(info->attrs[NLBL_MGMT_A_IPV4ADDR]) !=
151 		    sizeof(struct in_addr)) {
152 			ret_val = -EINVAL;
153 			goto add_free_addrmap;
154 		}
155 		if (nla_len(info->attrs[NLBL_MGMT_A_IPV4MASK]) !=
156 		    sizeof(struct in_addr)) {
157 			ret_val = -EINVAL;
158 			goto add_free_addrmap;
159 		}
160 		addr = nla_data(info->attrs[NLBL_MGMT_A_IPV4ADDR]);
161 		mask = nla_data(info->attrs[NLBL_MGMT_A_IPV4MASK]);
162 
163 		map = kzalloc(sizeof(*map), GFP_KERNEL);
164 		if (map == NULL) {
165 			ret_val = -ENOMEM;
166 			goto add_free_addrmap;
167 		}
168 		map->list.addr = addr->s_addr & mask->s_addr;
169 		map->list.mask = mask->s_addr;
170 		map->list.valid = 1;
171 		map->def.type = entry->def.type;
172 		if (cipsov4)
173 			map->def.cipso = cipsov4;
174 
175 		ret_val = netlbl_af4list_add(&map->list, &addrmap->list4);
176 		if (ret_val != 0) {
177 			kfree(map);
178 			goto add_free_addrmap;
179 		}
180 
181 		entry->def.type = NETLBL_NLTYPE_ADDRSELECT;
182 		entry->def.addrsel = addrmap;
183 #if IS_ENABLED(CONFIG_IPV6)
184 	} else if (info->attrs[NLBL_MGMT_A_IPV6ADDR]) {
185 		struct in6_addr *addr;
186 		struct in6_addr *mask;
187 		struct netlbl_domaddr6_map *map;
188 
189 		addrmap = kzalloc(sizeof(*addrmap), GFP_KERNEL);
190 		if (addrmap == NULL) {
191 			ret_val = -ENOMEM;
192 			goto add_doi_put_def;
193 		}
194 		INIT_LIST_HEAD(&addrmap->list4);
195 		INIT_LIST_HEAD(&addrmap->list6);
196 
197 		if (nla_len(info->attrs[NLBL_MGMT_A_IPV6ADDR]) !=
198 		    sizeof(struct in6_addr)) {
199 			ret_val = -EINVAL;
200 			goto add_free_addrmap;
201 		}
202 		if (nla_len(info->attrs[NLBL_MGMT_A_IPV6MASK]) !=
203 		    sizeof(struct in6_addr)) {
204 			ret_val = -EINVAL;
205 			goto add_free_addrmap;
206 		}
207 		addr = nla_data(info->attrs[NLBL_MGMT_A_IPV6ADDR]);
208 		mask = nla_data(info->attrs[NLBL_MGMT_A_IPV6MASK]);
209 
210 		map = kzalloc(sizeof(*map), GFP_KERNEL);
211 		if (map == NULL) {
212 			ret_val = -ENOMEM;
213 			goto add_free_addrmap;
214 		}
215 		map->list.addr = *addr;
216 		map->list.addr.s6_addr32[0] &= mask->s6_addr32[0];
217 		map->list.addr.s6_addr32[1] &= mask->s6_addr32[1];
218 		map->list.addr.s6_addr32[2] &= mask->s6_addr32[2];
219 		map->list.addr.s6_addr32[3] &= mask->s6_addr32[3];
220 		map->list.mask = *mask;
221 		map->list.valid = 1;
222 		map->def.type = entry->def.type;
223 
224 		ret_val = netlbl_af6list_add(&map->list, &addrmap->list6);
225 		if (ret_val != 0) {
226 			kfree(map);
227 			goto add_free_addrmap;
228 		}
229 
230 		entry->def.type = NETLBL_NLTYPE_ADDRSELECT;
231 		entry->def.addrsel = addrmap;
232 #endif /* IPv6 */
233 	}
234 
235 	ret_val = netlbl_domhsh_add(entry, audit_info);
236 	if (ret_val != 0)
237 		goto add_free_addrmap;
238 
239 	return 0;
240 
241 add_free_addrmap:
242 	kfree(addrmap);
243 add_doi_put_def:
244 	cipso_v4_doi_putdef(cipsov4);
245 add_free_domain:
246 	kfree(entry->domain);
247 add_free_entry:
248 	kfree(entry);
249 	return ret_val;
250 }
251 
252 /**
253  * netlbl_mgmt_listentry - List a NetLabel/LSM domain map entry
254  * @skb: the NETLINK buffer
255  * @entry: the map entry
256  *
257  * Description:
258  * This function is a helper function used by the LISTALL and LISTDEF command
259  * handlers.  The caller is responsible for ensuring that the RCU read lock
260  * is held.  Returns zero on success, negative values on failure.
261  *
262  */
263 static int netlbl_mgmt_listentry(struct sk_buff *skb,
264 				 struct netlbl_dom_map *entry)
265 {
266 	int ret_val = 0;
267 	struct nlattr *nla_a;
268 	struct nlattr *nla_b;
269 	struct netlbl_af4list *iter4;
270 #if IS_ENABLED(CONFIG_IPV6)
271 	struct netlbl_af6list *iter6;
272 #endif
273 
274 	if (entry->domain != NULL) {
275 		ret_val = nla_put_string(skb,
276 					 NLBL_MGMT_A_DOMAIN, entry->domain);
277 		if (ret_val != 0)
278 			return ret_val;
279 	}
280 
281 	switch (entry->def.type) {
282 	case NETLBL_NLTYPE_ADDRSELECT:
283 		nla_a = nla_nest_start(skb, NLBL_MGMT_A_SELECTORLIST);
284 		if (nla_a == NULL)
285 			return -ENOMEM;
286 
287 		netlbl_af4list_foreach_rcu(iter4, &entry->def.addrsel->list4) {
288 			struct netlbl_domaddr4_map *map4;
289 			struct in_addr addr_struct;
290 
291 			nla_b = nla_nest_start(skb, NLBL_MGMT_A_ADDRSELECTOR);
292 			if (nla_b == NULL)
293 				return -ENOMEM;
294 
295 			addr_struct.s_addr = iter4->addr;
296 			ret_val = nla_put_in_addr(skb, NLBL_MGMT_A_IPV4ADDR,
297 						  addr_struct.s_addr);
298 			if (ret_val != 0)
299 				return ret_val;
300 			addr_struct.s_addr = iter4->mask;
301 			ret_val = nla_put_in_addr(skb, NLBL_MGMT_A_IPV4MASK,
302 						  addr_struct.s_addr);
303 			if (ret_val != 0)
304 				return ret_val;
305 			map4 = netlbl_domhsh_addr4_entry(iter4);
306 			ret_val = nla_put_u32(skb, NLBL_MGMT_A_PROTOCOL,
307 					      map4->def.type);
308 			if (ret_val != 0)
309 				return ret_val;
310 			switch (map4->def.type) {
311 			case NETLBL_NLTYPE_CIPSOV4:
312 				ret_val = nla_put_u32(skb, NLBL_MGMT_A_CV4DOI,
313 						      map4->def.cipso->doi);
314 				if (ret_val != 0)
315 					return ret_val;
316 				break;
317 			}
318 
319 			nla_nest_end(skb, nla_b);
320 		}
321 #if IS_ENABLED(CONFIG_IPV6)
322 		netlbl_af6list_foreach_rcu(iter6, &entry->def.addrsel->list6) {
323 			struct netlbl_domaddr6_map *map6;
324 
325 			nla_b = nla_nest_start(skb, NLBL_MGMT_A_ADDRSELECTOR);
326 			if (nla_b == NULL)
327 				return -ENOMEM;
328 
329 			ret_val = nla_put_in6_addr(skb, NLBL_MGMT_A_IPV6ADDR,
330 						   &iter6->addr);
331 			if (ret_val != 0)
332 				return ret_val;
333 			ret_val = nla_put_in6_addr(skb, NLBL_MGMT_A_IPV6MASK,
334 						   &iter6->mask);
335 			if (ret_val != 0)
336 				return ret_val;
337 			map6 = netlbl_domhsh_addr6_entry(iter6);
338 			ret_val = nla_put_u32(skb, NLBL_MGMT_A_PROTOCOL,
339 					      map6->def.type);
340 			if (ret_val != 0)
341 				return ret_val;
342 
343 			nla_nest_end(skb, nla_b);
344 		}
345 #endif /* IPv6 */
346 
347 		nla_nest_end(skb, nla_a);
348 		break;
349 	case NETLBL_NLTYPE_UNLABELED:
350 		ret_val = nla_put_u32(skb,NLBL_MGMT_A_PROTOCOL,entry->def.type);
351 		break;
352 	case NETLBL_NLTYPE_CIPSOV4:
353 		ret_val = nla_put_u32(skb,NLBL_MGMT_A_PROTOCOL,entry->def.type);
354 		if (ret_val != 0)
355 			return ret_val;
356 		ret_val = nla_put_u32(skb, NLBL_MGMT_A_CV4DOI,
357 				      entry->def.cipso->doi);
358 		break;
359 	}
360 
361 	return ret_val;
362 }
363 
364 /*
365  * NetLabel Command Handlers
366  */
367 
368 /**
369  * netlbl_mgmt_add - Handle an ADD message
370  * @skb: the NETLINK buffer
371  * @info: the Generic NETLINK info block
372  *
373  * Description:
374  * Process a user generated ADD message and add the domains from the message
375  * to the hash table.  See netlabel.h for a description of the message format.
376  * Returns zero on success, negative values on failure.
377  *
378  */
379 static int netlbl_mgmt_add(struct sk_buff *skb, struct genl_info *info)
380 {
381 	struct netlbl_audit audit_info;
382 
383 	if ((!info->attrs[NLBL_MGMT_A_DOMAIN]) ||
384 	    (!info->attrs[NLBL_MGMT_A_PROTOCOL]) ||
385 	    (info->attrs[NLBL_MGMT_A_IPV4ADDR] &&
386 	     info->attrs[NLBL_MGMT_A_IPV6ADDR]) ||
387 	    (info->attrs[NLBL_MGMT_A_IPV4MASK] &&
388 	     info->attrs[NLBL_MGMT_A_IPV6MASK]) ||
389 	    ((info->attrs[NLBL_MGMT_A_IPV4ADDR] != NULL) ^
390 	     (info->attrs[NLBL_MGMT_A_IPV4MASK] != NULL)) ||
391 	    ((info->attrs[NLBL_MGMT_A_IPV6ADDR] != NULL) ^
392 	     (info->attrs[NLBL_MGMT_A_IPV6MASK] != NULL)))
393 		return -EINVAL;
394 
395 	netlbl_netlink_auditinfo(skb, &audit_info);
396 
397 	return netlbl_mgmt_add_common(info, &audit_info);
398 }
399 
400 /**
401  * netlbl_mgmt_remove - Handle a REMOVE message
402  * @skb: the NETLINK buffer
403  * @info: the Generic NETLINK info block
404  *
405  * Description:
406  * Process a user generated REMOVE message and remove the specified domain
407  * mappings.  Returns zero on success, negative values on failure.
408  *
409  */
410 static int netlbl_mgmt_remove(struct sk_buff *skb, struct genl_info *info)
411 {
412 	char *domain;
413 	struct netlbl_audit audit_info;
414 
415 	if (!info->attrs[NLBL_MGMT_A_DOMAIN])
416 		return -EINVAL;
417 
418 	netlbl_netlink_auditinfo(skb, &audit_info);
419 
420 	domain = nla_data(info->attrs[NLBL_MGMT_A_DOMAIN]);
421 	return netlbl_domhsh_remove(domain, &audit_info);
422 }
423 
424 /**
425  * netlbl_mgmt_listall_cb - netlbl_domhsh_walk() callback for LISTALL
426  * @entry: the domain mapping hash table entry
427  * @arg: the netlbl_domhsh_walk_arg structure
428  *
429  * Description:
430  * This function is designed to be used as a callback to the
431  * netlbl_domhsh_walk() function for use in generating a response for a LISTALL
432  * message.  Returns the size of the message on success, negative values on
433  * failure.
434  *
435  */
436 static int netlbl_mgmt_listall_cb(struct netlbl_dom_map *entry, void *arg)
437 {
438 	int ret_val = -ENOMEM;
439 	struct netlbl_domhsh_walk_arg *cb_arg = arg;
440 	void *data;
441 
442 	data = genlmsg_put(cb_arg->skb, NETLINK_CB(cb_arg->nl_cb->skb).portid,
443 			   cb_arg->seq, &netlbl_mgmt_gnl_family,
444 			   NLM_F_MULTI, NLBL_MGMT_C_LISTALL);
445 	if (data == NULL)
446 		goto listall_cb_failure;
447 
448 	ret_val = netlbl_mgmt_listentry(cb_arg->skb, entry);
449 	if (ret_val != 0)
450 		goto listall_cb_failure;
451 
452 	cb_arg->seq++;
453 	genlmsg_end(cb_arg->skb, data);
454 	return 0;
455 
456 listall_cb_failure:
457 	genlmsg_cancel(cb_arg->skb, data);
458 	return ret_val;
459 }
460 
461 /**
462  * netlbl_mgmt_listall - Handle a LISTALL message
463  * @skb: the NETLINK buffer
464  * @cb: the NETLINK callback
465  *
466  * Description:
467  * Process a user generated LISTALL message and dumps the domain hash table in
468  * a form suitable for use in a kernel generated LISTALL message.  Returns zero
469  * on success, negative values on failure.
470  *
471  */
472 static int netlbl_mgmt_listall(struct sk_buff *skb,
473 			       struct netlink_callback *cb)
474 {
475 	struct netlbl_domhsh_walk_arg cb_arg;
476 	u32 skip_bkt = cb->args[0];
477 	u32 skip_chain = cb->args[1];
478 
479 	cb_arg.nl_cb = cb;
480 	cb_arg.skb = skb;
481 	cb_arg.seq = cb->nlh->nlmsg_seq;
482 
483 	netlbl_domhsh_walk(&skip_bkt,
484 			   &skip_chain,
485 			   netlbl_mgmt_listall_cb,
486 			   &cb_arg);
487 
488 	cb->args[0] = skip_bkt;
489 	cb->args[1] = skip_chain;
490 	return skb->len;
491 }
492 
493 /**
494  * netlbl_mgmt_adddef - Handle an ADDDEF message
495  * @skb: the NETLINK buffer
496  * @info: the Generic NETLINK info block
497  *
498  * Description:
499  * Process a user generated ADDDEF message and respond accordingly.  Returns
500  * zero on success, negative values on failure.
501  *
502  */
503 static int netlbl_mgmt_adddef(struct sk_buff *skb, struct genl_info *info)
504 {
505 	struct netlbl_audit audit_info;
506 
507 	if ((!info->attrs[NLBL_MGMT_A_PROTOCOL]) ||
508 	    (info->attrs[NLBL_MGMT_A_IPV4ADDR] &&
509 	     info->attrs[NLBL_MGMT_A_IPV6ADDR]) ||
510 	    (info->attrs[NLBL_MGMT_A_IPV4MASK] &&
511 	     info->attrs[NLBL_MGMT_A_IPV6MASK]) ||
512 	    ((info->attrs[NLBL_MGMT_A_IPV4ADDR] != NULL) ^
513 	     (info->attrs[NLBL_MGMT_A_IPV4MASK] != NULL)) ||
514 	    ((info->attrs[NLBL_MGMT_A_IPV6ADDR] != NULL) ^
515 	     (info->attrs[NLBL_MGMT_A_IPV6MASK] != NULL)))
516 		return -EINVAL;
517 
518 	netlbl_netlink_auditinfo(skb, &audit_info);
519 
520 	return netlbl_mgmt_add_common(info, &audit_info);
521 }
522 
523 /**
524  * netlbl_mgmt_removedef - Handle a REMOVEDEF message
525  * @skb: the NETLINK buffer
526  * @info: the Generic NETLINK info block
527  *
528  * Description:
529  * Process a user generated REMOVEDEF message and remove the default domain
530  * mapping.  Returns zero on success, negative values on failure.
531  *
532  */
533 static int netlbl_mgmt_removedef(struct sk_buff *skb, struct genl_info *info)
534 {
535 	struct netlbl_audit audit_info;
536 
537 	netlbl_netlink_auditinfo(skb, &audit_info);
538 
539 	return netlbl_domhsh_remove_default(&audit_info);
540 }
541 
542 /**
543  * netlbl_mgmt_listdef - Handle a LISTDEF message
544  * @skb: the NETLINK buffer
545  * @info: the Generic NETLINK info block
546  *
547  * Description:
548  * Process a user generated LISTDEF message and dumps the default domain
549  * mapping in a form suitable for use in a kernel generated LISTDEF message.
550  * Returns zero on success, negative values on failure.
551  *
552  */
553 static int netlbl_mgmt_listdef(struct sk_buff *skb, struct genl_info *info)
554 {
555 	int ret_val = -ENOMEM;
556 	struct sk_buff *ans_skb = NULL;
557 	void *data;
558 	struct netlbl_dom_map *entry;
559 
560 	ans_skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
561 	if (ans_skb == NULL)
562 		return -ENOMEM;
563 	data = genlmsg_put_reply(ans_skb, info, &netlbl_mgmt_gnl_family,
564 				 0, NLBL_MGMT_C_LISTDEF);
565 	if (data == NULL)
566 		goto listdef_failure;
567 
568 	rcu_read_lock();
569 	entry = netlbl_domhsh_getentry(NULL);
570 	if (entry == NULL) {
571 		ret_val = -ENOENT;
572 		goto listdef_failure_lock;
573 	}
574 	ret_val = netlbl_mgmt_listentry(ans_skb, entry);
575 	rcu_read_unlock();
576 	if (ret_val != 0)
577 		goto listdef_failure;
578 
579 	genlmsg_end(ans_skb, data);
580 	return genlmsg_reply(ans_skb, info);
581 
582 listdef_failure_lock:
583 	rcu_read_unlock();
584 listdef_failure:
585 	kfree_skb(ans_skb);
586 	return ret_val;
587 }
588 
589 /**
590  * netlbl_mgmt_protocols_cb - Write an individual PROTOCOL message response
591  * @skb: the skb to write to
592  * @cb: the NETLINK callback
593  * @protocol: the NetLabel protocol to use in the message
594  *
595  * Description:
596  * This function is to be used in conjunction with netlbl_mgmt_protocols() to
597  * answer a application's PROTOCOLS message.  Returns the size of the message
598  * on success, negative values on failure.
599  *
600  */
601 static int netlbl_mgmt_protocols_cb(struct sk_buff *skb,
602 				    struct netlink_callback *cb,
603 				    u32 protocol)
604 {
605 	int ret_val = -ENOMEM;
606 	void *data;
607 
608 	data = genlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq,
609 			   &netlbl_mgmt_gnl_family, NLM_F_MULTI,
610 			   NLBL_MGMT_C_PROTOCOLS);
611 	if (data == NULL)
612 		goto protocols_cb_failure;
613 
614 	ret_val = nla_put_u32(skb, NLBL_MGMT_A_PROTOCOL, protocol);
615 	if (ret_val != 0)
616 		goto protocols_cb_failure;
617 
618 	genlmsg_end(skb, data);
619 	return 0;
620 
621 protocols_cb_failure:
622 	genlmsg_cancel(skb, data);
623 	return ret_val;
624 }
625 
626 /**
627  * netlbl_mgmt_protocols - Handle a PROTOCOLS message
628  * @skb: the NETLINK buffer
629  * @cb: the NETLINK callback
630  *
631  * Description:
632  * Process a user generated PROTOCOLS message and respond accordingly.
633  *
634  */
635 static int netlbl_mgmt_protocols(struct sk_buff *skb,
636 				 struct netlink_callback *cb)
637 {
638 	u32 protos_sent = cb->args[0];
639 
640 	if (protos_sent == 0) {
641 		if (netlbl_mgmt_protocols_cb(skb,
642 					     cb,
643 					     NETLBL_NLTYPE_UNLABELED) < 0)
644 			goto protocols_return;
645 		protos_sent++;
646 	}
647 	if (protos_sent == 1) {
648 		if (netlbl_mgmt_protocols_cb(skb,
649 					     cb,
650 					     NETLBL_NLTYPE_CIPSOV4) < 0)
651 			goto protocols_return;
652 		protos_sent++;
653 	}
654 
655 protocols_return:
656 	cb->args[0] = protos_sent;
657 	return skb->len;
658 }
659 
660 /**
661  * netlbl_mgmt_version - Handle a VERSION message
662  * @skb: the NETLINK buffer
663  * @info: the Generic NETLINK info block
664  *
665  * Description:
666  * Process a user generated VERSION message and respond accordingly.  Returns
667  * zero on success, negative values on failure.
668  *
669  */
670 static int netlbl_mgmt_version(struct sk_buff *skb, struct genl_info *info)
671 {
672 	int ret_val = -ENOMEM;
673 	struct sk_buff *ans_skb = NULL;
674 	void *data;
675 
676 	ans_skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
677 	if (ans_skb == NULL)
678 		return -ENOMEM;
679 	data = genlmsg_put_reply(ans_skb, info, &netlbl_mgmt_gnl_family,
680 				 0, NLBL_MGMT_C_VERSION);
681 	if (data == NULL)
682 		goto version_failure;
683 
684 	ret_val = nla_put_u32(ans_skb,
685 			      NLBL_MGMT_A_VERSION,
686 			      NETLBL_PROTO_VERSION);
687 	if (ret_val != 0)
688 		goto version_failure;
689 
690 	genlmsg_end(ans_skb, data);
691 	return genlmsg_reply(ans_skb, info);
692 
693 version_failure:
694 	kfree_skb(ans_skb);
695 	return ret_val;
696 }
697 
698 
699 /*
700  * NetLabel Generic NETLINK Command Definitions
701  */
702 
703 static const struct genl_ops netlbl_mgmt_genl_ops[] = {
704 	{
705 	.cmd = NLBL_MGMT_C_ADD,
706 	.flags = GENL_ADMIN_PERM,
707 	.policy = netlbl_mgmt_genl_policy,
708 	.doit = netlbl_mgmt_add,
709 	.dumpit = NULL,
710 	},
711 	{
712 	.cmd = NLBL_MGMT_C_REMOVE,
713 	.flags = GENL_ADMIN_PERM,
714 	.policy = netlbl_mgmt_genl_policy,
715 	.doit = netlbl_mgmt_remove,
716 	.dumpit = NULL,
717 	},
718 	{
719 	.cmd = NLBL_MGMT_C_LISTALL,
720 	.flags = 0,
721 	.policy = netlbl_mgmt_genl_policy,
722 	.doit = NULL,
723 	.dumpit = netlbl_mgmt_listall,
724 	},
725 	{
726 	.cmd = NLBL_MGMT_C_ADDDEF,
727 	.flags = GENL_ADMIN_PERM,
728 	.policy = netlbl_mgmt_genl_policy,
729 	.doit = netlbl_mgmt_adddef,
730 	.dumpit = NULL,
731 	},
732 	{
733 	.cmd = NLBL_MGMT_C_REMOVEDEF,
734 	.flags = GENL_ADMIN_PERM,
735 	.policy = netlbl_mgmt_genl_policy,
736 	.doit = netlbl_mgmt_removedef,
737 	.dumpit = NULL,
738 	},
739 	{
740 	.cmd = NLBL_MGMT_C_LISTDEF,
741 	.flags = 0,
742 	.policy = netlbl_mgmt_genl_policy,
743 	.doit = netlbl_mgmt_listdef,
744 	.dumpit = NULL,
745 	},
746 	{
747 	.cmd = NLBL_MGMT_C_PROTOCOLS,
748 	.flags = 0,
749 	.policy = netlbl_mgmt_genl_policy,
750 	.doit = NULL,
751 	.dumpit = netlbl_mgmt_protocols,
752 	},
753 	{
754 	.cmd = NLBL_MGMT_C_VERSION,
755 	.flags = 0,
756 	.policy = netlbl_mgmt_genl_policy,
757 	.doit = netlbl_mgmt_version,
758 	.dumpit = NULL,
759 	},
760 };
761 
762 /*
763  * NetLabel Generic NETLINK Protocol Functions
764  */
765 
766 /**
767  * netlbl_mgmt_genl_init - Register the NetLabel management component
768  *
769  * Description:
770  * Register the NetLabel management component with the Generic NETLINK
771  * mechanism.  Returns zero on success, negative values on failure.
772  *
773  */
774 int __init netlbl_mgmt_genl_init(void)
775 {
776 	return genl_register_family_with_ops(&netlbl_mgmt_gnl_family,
777 					     netlbl_mgmt_genl_ops);
778 }
779