xref: /openbmc/linux/net/netlabel/netlabel_mgmt.c (revision 79f08d9e)
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, 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/in.h>
36 #include <linux/in6.h>
37 #include <linux/slab.h>
38 #include <net/sock.h>
39 #include <net/netlink.h>
40 #include <net/genetlink.h>
41 #include <net/ip.h>
42 #include <net/ipv6.h>
43 #include <net/netlabel.h>
44 #include <net/cipso_ipv4.h>
45 #include <linux/atomic.h>
46 
47 #include "netlabel_domainhash.h"
48 #include "netlabel_user.h"
49 #include "netlabel_mgmt.h"
50 
51 /* NetLabel configured protocol counter */
52 atomic_t netlabel_mgmt_protocount = ATOMIC_INIT(0);
53 
54 /* Argument struct for netlbl_domhsh_walk() */
55 struct netlbl_domhsh_walk_arg {
56 	struct netlink_callback *nl_cb;
57 	struct sk_buff *skb;
58 	u32 seq;
59 };
60 
61 /* NetLabel Generic NETLINK CIPSOv4 family */
62 static struct genl_family netlbl_mgmt_gnl_family = {
63 	.id = GENL_ID_GENERATE,
64 	.hdrsize = 0,
65 	.name = NETLBL_NLTYPE_MGMT_NAME,
66 	.version = NETLBL_PROTO_VERSION,
67 	.maxattr = NLBL_MGMT_A_MAX,
68 };
69 
70 /* NetLabel Netlink attribute policy */
71 static const struct nla_policy netlbl_mgmt_genl_policy[NLBL_MGMT_A_MAX + 1] = {
72 	[NLBL_MGMT_A_DOMAIN] = { .type = NLA_NUL_STRING },
73 	[NLBL_MGMT_A_PROTOCOL] = { .type = NLA_U32 },
74 	[NLBL_MGMT_A_VERSION] = { .type = NLA_U32 },
75 	[NLBL_MGMT_A_CV4DOI] = { .type = NLA_U32 },
76 };
77 
78 /*
79  * Helper Functions
80  */
81 
82 /**
83  * netlbl_mgmt_add - Handle an ADD message
84  * @info: the Generic NETLINK info block
85  * @audit_info: NetLabel audit information
86  *
87  * Description:
88  * Helper function for the ADD and ADDDEF messages to add the domain mappings
89  * from the message to the hash table.  See netlabel.h for a description of the
90  * message format.  Returns zero on success, negative values on failure.
91  *
92  */
93 static int netlbl_mgmt_add_common(struct genl_info *info,
94 				  struct netlbl_audit *audit_info)
95 {
96 	int ret_val = -EINVAL;
97 	struct netlbl_dom_map *entry = NULL;
98 	struct netlbl_domaddr_map *addrmap = NULL;
99 	struct cipso_v4_doi *cipsov4 = NULL;
100 	u32 tmp_val;
101 
102 	entry = kzalloc(sizeof(*entry), GFP_KERNEL);
103 	if (entry == NULL) {
104 		ret_val = -ENOMEM;
105 		goto add_failure;
106 	}
107 	entry->def.type = nla_get_u32(info->attrs[NLBL_MGMT_A_PROTOCOL]);
108 	if (info->attrs[NLBL_MGMT_A_DOMAIN]) {
109 		size_t tmp_size = nla_len(info->attrs[NLBL_MGMT_A_DOMAIN]);
110 		entry->domain = kmalloc(tmp_size, GFP_KERNEL);
111 		if (entry->domain == NULL) {
112 			ret_val = -ENOMEM;
113 			goto add_failure;
114 		}
115 		nla_strlcpy(entry->domain,
116 			    info->attrs[NLBL_MGMT_A_DOMAIN], tmp_size);
117 	}
118 
119 	/* NOTE: internally we allow/use a entry->def.type value of
120 	 *       NETLBL_NLTYPE_ADDRSELECT but we don't currently allow users
121 	 *       to pass that as a protocol value because we need to know the
122 	 *       "real" protocol */
123 
124 	switch (entry->def.type) {
125 	case NETLBL_NLTYPE_UNLABELED:
126 		break;
127 	case NETLBL_NLTYPE_CIPSOV4:
128 		if (!info->attrs[NLBL_MGMT_A_CV4DOI])
129 			goto add_failure;
130 
131 		tmp_val = nla_get_u32(info->attrs[NLBL_MGMT_A_CV4DOI]);
132 		cipsov4 = cipso_v4_doi_getdef(tmp_val);
133 		if (cipsov4 == NULL)
134 			goto add_failure;
135 		entry->def.cipso = cipsov4;
136 		break;
137 	default:
138 		goto add_failure;
139 	}
140 
141 	if (info->attrs[NLBL_MGMT_A_IPV4ADDR]) {
142 		struct in_addr *addr;
143 		struct in_addr *mask;
144 		struct netlbl_domaddr4_map *map;
145 
146 		addrmap = kzalloc(sizeof(*addrmap), GFP_KERNEL);
147 		if (addrmap == NULL) {
148 			ret_val = -ENOMEM;
149 			goto add_failure;
150 		}
151 		INIT_LIST_HEAD(&addrmap->list4);
152 		INIT_LIST_HEAD(&addrmap->list6);
153 
154 		if (nla_len(info->attrs[NLBL_MGMT_A_IPV4ADDR]) !=
155 		    sizeof(struct in_addr)) {
156 			ret_val = -EINVAL;
157 			goto add_failure;
158 		}
159 		if (nla_len(info->attrs[NLBL_MGMT_A_IPV4MASK]) !=
160 		    sizeof(struct in_addr)) {
161 			ret_val = -EINVAL;
162 			goto add_failure;
163 		}
164 		addr = nla_data(info->attrs[NLBL_MGMT_A_IPV4ADDR]);
165 		mask = nla_data(info->attrs[NLBL_MGMT_A_IPV4MASK]);
166 
167 		map = kzalloc(sizeof(*map), GFP_KERNEL);
168 		if (map == NULL) {
169 			ret_val = -ENOMEM;
170 			goto add_failure;
171 		}
172 		map->list.addr = addr->s_addr & mask->s_addr;
173 		map->list.mask = mask->s_addr;
174 		map->list.valid = 1;
175 		map->def.type = entry->def.type;
176 		if (cipsov4)
177 			map->def.cipso = cipsov4;
178 
179 		ret_val = netlbl_af4list_add(&map->list, &addrmap->list4);
180 		if (ret_val != 0) {
181 			kfree(map);
182 			goto add_failure;
183 		}
184 
185 		entry->def.type = NETLBL_NLTYPE_ADDRSELECT;
186 		entry->def.addrsel = addrmap;
187 #if IS_ENABLED(CONFIG_IPV6)
188 	} else if (info->attrs[NLBL_MGMT_A_IPV6ADDR]) {
189 		struct in6_addr *addr;
190 		struct in6_addr *mask;
191 		struct netlbl_domaddr6_map *map;
192 
193 		addrmap = kzalloc(sizeof(*addrmap), GFP_KERNEL);
194 		if (addrmap == NULL) {
195 			ret_val = -ENOMEM;
196 			goto add_failure;
197 		}
198 		INIT_LIST_HEAD(&addrmap->list4);
199 		INIT_LIST_HEAD(&addrmap->list6);
200 
201 		if (nla_len(info->attrs[NLBL_MGMT_A_IPV6ADDR]) !=
202 		    sizeof(struct in6_addr)) {
203 			ret_val = -EINVAL;
204 			goto add_failure;
205 		}
206 		if (nla_len(info->attrs[NLBL_MGMT_A_IPV6MASK]) !=
207 		    sizeof(struct in6_addr)) {
208 			ret_val = -EINVAL;
209 			goto add_failure;
210 		}
211 		addr = nla_data(info->attrs[NLBL_MGMT_A_IPV6ADDR]);
212 		mask = nla_data(info->attrs[NLBL_MGMT_A_IPV6MASK]);
213 
214 		map = kzalloc(sizeof(*map), GFP_KERNEL);
215 		if (map == NULL) {
216 			ret_val = -ENOMEM;
217 			goto add_failure;
218 		}
219 		map->list.addr = *addr;
220 		map->list.addr.s6_addr32[0] &= mask->s6_addr32[0];
221 		map->list.addr.s6_addr32[1] &= mask->s6_addr32[1];
222 		map->list.addr.s6_addr32[2] &= mask->s6_addr32[2];
223 		map->list.addr.s6_addr32[3] &= mask->s6_addr32[3];
224 		map->list.mask = *mask;
225 		map->list.valid = 1;
226 		map->def.type = entry->def.type;
227 
228 		ret_val = netlbl_af6list_add(&map->list, &addrmap->list6);
229 		if (ret_val != 0) {
230 			kfree(map);
231 			goto add_failure;
232 		}
233 
234 		entry->def.type = NETLBL_NLTYPE_ADDRSELECT;
235 		entry->def.addrsel = addrmap;
236 #endif /* IPv6 */
237 	}
238 
239 	ret_val = netlbl_domhsh_add(entry, audit_info);
240 	if (ret_val != 0)
241 		goto add_failure;
242 
243 	return 0;
244 
245 add_failure:
246 	if (cipsov4)
247 		cipso_v4_doi_putdef(cipsov4);
248 	if (entry)
249 		kfree(entry->domain);
250 	kfree(addrmap);
251 	kfree(entry);
252 	return ret_val;
253 }
254 
255 /**
256  * netlbl_mgmt_listentry - List a NetLabel/LSM domain map entry
257  * @skb: the NETLINK buffer
258  * @entry: the map entry
259  *
260  * Description:
261  * This function is a helper function used by the LISTALL and LISTDEF command
262  * handlers.  The caller is responsible for ensuring that the RCU read lock
263  * is held.  Returns zero on success, negative values on failure.
264  *
265  */
266 static int netlbl_mgmt_listentry(struct sk_buff *skb,
267 				 struct netlbl_dom_map *entry)
268 {
269 	int ret_val = 0;
270 	struct nlattr *nla_a;
271 	struct nlattr *nla_b;
272 	struct netlbl_af4list *iter4;
273 #if IS_ENABLED(CONFIG_IPV6)
274 	struct netlbl_af6list *iter6;
275 #endif
276 
277 	if (entry->domain != NULL) {
278 		ret_val = nla_put_string(skb,
279 					 NLBL_MGMT_A_DOMAIN, entry->domain);
280 		if (ret_val != 0)
281 			return ret_val;
282 	}
283 
284 	switch (entry->def.type) {
285 	case NETLBL_NLTYPE_ADDRSELECT:
286 		nla_a = nla_nest_start(skb, NLBL_MGMT_A_SELECTORLIST);
287 		if (nla_a == NULL)
288 			return -ENOMEM;
289 
290 		netlbl_af4list_foreach_rcu(iter4, &entry->def.addrsel->list4) {
291 			struct netlbl_domaddr4_map *map4;
292 			struct in_addr addr_struct;
293 
294 			nla_b = nla_nest_start(skb, NLBL_MGMT_A_ADDRSELECTOR);
295 			if (nla_b == NULL)
296 				return -ENOMEM;
297 
298 			addr_struct.s_addr = iter4->addr;
299 			ret_val = nla_put(skb, NLBL_MGMT_A_IPV4ADDR,
300 					  sizeof(struct in_addr),
301 					  &addr_struct);
302 			if (ret_val != 0)
303 				return ret_val;
304 			addr_struct.s_addr = iter4->mask;
305 			ret_val = nla_put(skb, NLBL_MGMT_A_IPV4MASK,
306 					  sizeof(struct in_addr),
307 					  &addr_struct);
308 			if (ret_val != 0)
309 				return ret_val;
310 			map4 = netlbl_domhsh_addr4_entry(iter4);
311 			ret_val = nla_put_u32(skb, NLBL_MGMT_A_PROTOCOL,
312 					      map4->def.type);
313 			if (ret_val != 0)
314 				return ret_val;
315 			switch (map4->def.type) {
316 			case NETLBL_NLTYPE_CIPSOV4:
317 				ret_val = nla_put_u32(skb, NLBL_MGMT_A_CV4DOI,
318 						      map4->def.cipso->doi);
319 				if (ret_val != 0)
320 					return ret_val;
321 				break;
322 			}
323 
324 			nla_nest_end(skb, nla_b);
325 		}
326 #if IS_ENABLED(CONFIG_IPV6)
327 		netlbl_af6list_foreach_rcu(iter6, &entry->def.addrsel->list6) {
328 			struct netlbl_domaddr6_map *map6;
329 
330 			nla_b = nla_nest_start(skb, NLBL_MGMT_A_ADDRSELECTOR);
331 			if (nla_b == NULL)
332 				return -ENOMEM;
333 
334 			ret_val = nla_put(skb, NLBL_MGMT_A_IPV6ADDR,
335 					  sizeof(struct in6_addr),
336 					  &iter6->addr);
337 			if (ret_val != 0)
338 				return ret_val;
339 			ret_val = nla_put(skb, NLBL_MGMT_A_IPV6MASK,
340 					  sizeof(struct in6_addr),
341 					  &iter6->mask);
342 			if (ret_val != 0)
343 				return ret_val;
344 			map6 = netlbl_domhsh_addr6_entry(iter6);
345 			ret_val = nla_put_u32(skb, NLBL_MGMT_A_PROTOCOL,
346 					      map6->def.type);
347 			if (ret_val != 0)
348 				return ret_val;
349 
350 			nla_nest_end(skb, nla_b);
351 		}
352 #endif /* IPv6 */
353 
354 		nla_nest_end(skb, nla_a);
355 		break;
356 	case NETLBL_NLTYPE_UNLABELED:
357 		ret_val = nla_put_u32(skb,NLBL_MGMT_A_PROTOCOL,entry->def.type);
358 		break;
359 	case NETLBL_NLTYPE_CIPSOV4:
360 		ret_val = nla_put_u32(skb,NLBL_MGMT_A_PROTOCOL,entry->def.type);
361 		if (ret_val != 0)
362 			return ret_val;
363 		ret_val = nla_put_u32(skb, NLBL_MGMT_A_CV4DOI,
364 				      entry->def.cipso->doi);
365 		break;
366 	}
367 
368 	return ret_val;
369 }
370 
371 /*
372  * NetLabel Command Handlers
373  */
374 
375 /**
376  * netlbl_mgmt_add - Handle an ADD message
377  * @skb: the NETLINK buffer
378  * @info: the Generic NETLINK info block
379  *
380  * Description:
381  * Process a user generated ADD message and add the domains from the message
382  * to the hash table.  See netlabel.h for a description of the message format.
383  * Returns zero on success, negative values on failure.
384  *
385  */
386 static int netlbl_mgmt_add(struct sk_buff *skb, struct genl_info *info)
387 {
388 	struct netlbl_audit audit_info;
389 
390 	if ((!info->attrs[NLBL_MGMT_A_DOMAIN]) ||
391 	    (!info->attrs[NLBL_MGMT_A_PROTOCOL]) ||
392 	    (info->attrs[NLBL_MGMT_A_IPV4ADDR] &&
393 	     info->attrs[NLBL_MGMT_A_IPV6ADDR]) ||
394 	    (info->attrs[NLBL_MGMT_A_IPV4MASK] &&
395 	     info->attrs[NLBL_MGMT_A_IPV6MASK]) ||
396 	    ((info->attrs[NLBL_MGMT_A_IPV4ADDR] != NULL) ^
397 	     (info->attrs[NLBL_MGMT_A_IPV4MASK] != NULL)) ||
398 	    ((info->attrs[NLBL_MGMT_A_IPV6ADDR] != NULL) ^
399 	     (info->attrs[NLBL_MGMT_A_IPV6MASK] != NULL)))
400 		return -EINVAL;
401 
402 	netlbl_netlink_auditinfo(skb, &audit_info);
403 
404 	return netlbl_mgmt_add_common(info, &audit_info);
405 }
406 
407 /**
408  * netlbl_mgmt_remove - Handle a REMOVE message
409  * @skb: the NETLINK buffer
410  * @info: the Generic NETLINK info block
411  *
412  * Description:
413  * Process a user generated REMOVE message and remove the specified domain
414  * mappings.  Returns zero on success, negative values on failure.
415  *
416  */
417 static int netlbl_mgmt_remove(struct sk_buff *skb, struct genl_info *info)
418 {
419 	char *domain;
420 	struct netlbl_audit audit_info;
421 
422 	if (!info->attrs[NLBL_MGMT_A_DOMAIN])
423 		return -EINVAL;
424 
425 	netlbl_netlink_auditinfo(skb, &audit_info);
426 
427 	domain = nla_data(info->attrs[NLBL_MGMT_A_DOMAIN]);
428 	return netlbl_domhsh_remove(domain, &audit_info);
429 }
430 
431 /**
432  * netlbl_mgmt_listall_cb - netlbl_domhsh_walk() callback for LISTALL
433  * @entry: the domain mapping hash table entry
434  * @arg: the netlbl_domhsh_walk_arg structure
435  *
436  * Description:
437  * This function is designed to be used as a callback to the
438  * netlbl_domhsh_walk() function for use in generating a response for a LISTALL
439  * message.  Returns the size of the message on success, negative values on
440  * failure.
441  *
442  */
443 static int netlbl_mgmt_listall_cb(struct netlbl_dom_map *entry, void *arg)
444 {
445 	int ret_val = -ENOMEM;
446 	struct netlbl_domhsh_walk_arg *cb_arg = arg;
447 	void *data;
448 
449 	data = genlmsg_put(cb_arg->skb, NETLINK_CB(cb_arg->nl_cb->skb).portid,
450 			   cb_arg->seq, &netlbl_mgmt_gnl_family,
451 			   NLM_F_MULTI, NLBL_MGMT_C_LISTALL);
452 	if (data == NULL)
453 		goto listall_cb_failure;
454 
455 	ret_val = netlbl_mgmt_listentry(cb_arg->skb, entry);
456 	if (ret_val != 0)
457 		goto listall_cb_failure;
458 
459 	cb_arg->seq++;
460 	return genlmsg_end(cb_arg->skb, data);
461 
462 listall_cb_failure:
463 	genlmsg_cancel(cb_arg->skb, data);
464 	return ret_val;
465 }
466 
467 /**
468  * netlbl_mgmt_listall - Handle a LISTALL message
469  * @skb: the NETLINK buffer
470  * @cb: the NETLINK callback
471  *
472  * Description:
473  * Process a user generated LISTALL message and dumps the domain hash table in
474  * a form suitable for use in a kernel generated LISTALL message.  Returns zero
475  * on success, negative values on failure.
476  *
477  */
478 static int netlbl_mgmt_listall(struct sk_buff *skb,
479 			       struct netlink_callback *cb)
480 {
481 	struct netlbl_domhsh_walk_arg cb_arg;
482 	u32 skip_bkt = cb->args[0];
483 	u32 skip_chain = cb->args[1];
484 
485 	cb_arg.nl_cb = cb;
486 	cb_arg.skb = skb;
487 	cb_arg.seq = cb->nlh->nlmsg_seq;
488 
489 	netlbl_domhsh_walk(&skip_bkt,
490 			   &skip_chain,
491 			   netlbl_mgmt_listall_cb,
492 			   &cb_arg);
493 
494 	cb->args[0] = skip_bkt;
495 	cb->args[1] = skip_chain;
496 	return skb->len;
497 }
498 
499 /**
500  * netlbl_mgmt_adddef - Handle an ADDDEF message
501  * @skb: the NETLINK buffer
502  * @info: the Generic NETLINK info block
503  *
504  * Description:
505  * Process a user generated ADDDEF message and respond accordingly.  Returns
506  * zero on success, negative values on failure.
507  *
508  */
509 static int netlbl_mgmt_adddef(struct sk_buff *skb, struct genl_info *info)
510 {
511 	struct netlbl_audit audit_info;
512 
513 	if ((!info->attrs[NLBL_MGMT_A_PROTOCOL]) ||
514 	    (info->attrs[NLBL_MGMT_A_IPV4ADDR] &&
515 	     info->attrs[NLBL_MGMT_A_IPV6ADDR]) ||
516 	    (info->attrs[NLBL_MGMT_A_IPV4MASK] &&
517 	     info->attrs[NLBL_MGMT_A_IPV6MASK]) ||
518 	    ((info->attrs[NLBL_MGMT_A_IPV4ADDR] != NULL) ^
519 	     (info->attrs[NLBL_MGMT_A_IPV4MASK] != NULL)) ||
520 	    ((info->attrs[NLBL_MGMT_A_IPV6ADDR] != NULL) ^
521 	     (info->attrs[NLBL_MGMT_A_IPV6MASK] != NULL)))
522 		return -EINVAL;
523 
524 	netlbl_netlink_auditinfo(skb, &audit_info);
525 
526 	return netlbl_mgmt_add_common(info, &audit_info);
527 }
528 
529 /**
530  * netlbl_mgmt_removedef - Handle a REMOVEDEF message
531  * @skb: the NETLINK buffer
532  * @info: the Generic NETLINK info block
533  *
534  * Description:
535  * Process a user generated REMOVEDEF message and remove the default domain
536  * mapping.  Returns zero on success, negative values on failure.
537  *
538  */
539 static int netlbl_mgmt_removedef(struct sk_buff *skb, struct genl_info *info)
540 {
541 	struct netlbl_audit audit_info;
542 
543 	netlbl_netlink_auditinfo(skb, &audit_info);
544 
545 	return netlbl_domhsh_remove_default(&audit_info);
546 }
547 
548 /**
549  * netlbl_mgmt_listdef - Handle a LISTDEF message
550  * @skb: the NETLINK buffer
551  * @info: the Generic NETLINK info block
552  *
553  * Description:
554  * Process a user generated LISTDEF message and dumps the default domain
555  * mapping in a form suitable for use in a kernel generated LISTDEF message.
556  * Returns zero on success, negative values on failure.
557  *
558  */
559 static int netlbl_mgmt_listdef(struct sk_buff *skb, struct genl_info *info)
560 {
561 	int ret_val = -ENOMEM;
562 	struct sk_buff *ans_skb = NULL;
563 	void *data;
564 	struct netlbl_dom_map *entry;
565 
566 	ans_skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
567 	if (ans_skb == NULL)
568 		return -ENOMEM;
569 	data = genlmsg_put_reply(ans_skb, info, &netlbl_mgmt_gnl_family,
570 				 0, NLBL_MGMT_C_LISTDEF);
571 	if (data == NULL)
572 		goto listdef_failure;
573 
574 	rcu_read_lock();
575 	entry = netlbl_domhsh_getentry(NULL);
576 	if (entry == NULL) {
577 		ret_val = -ENOENT;
578 		goto listdef_failure_lock;
579 	}
580 	ret_val = netlbl_mgmt_listentry(ans_skb, entry);
581 	rcu_read_unlock();
582 	if (ret_val != 0)
583 		goto listdef_failure;
584 
585 	genlmsg_end(ans_skb, data);
586 	return genlmsg_reply(ans_skb, info);
587 
588 listdef_failure_lock:
589 	rcu_read_unlock();
590 listdef_failure:
591 	kfree_skb(ans_skb);
592 	return ret_val;
593 }
594 
595 /**
596  * netlbl_mgmt_protocols_cb - Write an individual PROTOCOL message response
597  * @skb: the skb to write to
598  * @cb: the NETLINK callback
599  * @protocol: the NetLabel protocol to use in the message
600  *
601  * Description:
602  * This function is to be used in conjunction with netlbl_mgmt_protocols() to
603  * answer a application's PROTOCOLS message.  Returns the size of the message
604  * on success, negative values on failure.
605  *
606  */
607 static int netlbl_mgmt_protocols_cb(struct sk_buff *skb,
608 				    struct netlink_callback *cb,
609 				    u32 protocol)
610 {
611 	int ret_val = -ENOMEM;
612 	void *data;
613 
614 	data = genlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq,
615 			   &netlbl_mgmt_gnl_family, NLM_F_MULTI,
616 			   NLBL_MGMT_C_PROTOCOLS);
617 	if (data == NULL)
618 		goto protocols_cb_failure;
619 
620 	ret_val = nla_put_u32(skb, NLBL_MGMT_A_PROTOCOL, protocol);
621 	if (ret_val != 0)
622 		goto protocols_cb_failure;
623 
624 	return genlmsg_end(skb, data);
625 
626 protocols_cb_failure:
627 	genlmsg_cancel(skb, data);
628 	return ret_val;
629 }
630 
631 /**
632  * netlbl_mgmt_protocols - Handle a PROTOCOLS message
633  * @skb: the NETLINK buffer
634  * @cb: the NETLINK callback
635  *
636  * Description:
637  * Process a user generated PROTOCOLS message and respond accordingly.
638  *
639  */
640 static int netlbl_mgmt_protocols(struct sk_buff *skb,
641 				 struct netlink_callback *cb)
642 {
643 	u32 protos_sent = cb->args[0];
644 
645 	if (protos_sent == 0) {
646 		if (netlbl_mgmt_protocols_cb(skb,
647 					     cb,
648 					     NETLBL_NLTYPE_UNLABELED) < 0)
649 			goto protocols_return;
650 		protos_sent++;
651 	}
652 	if (protos_sent == 1) {
653 		if (netlbl_mgmt_protocols_cb(skb,
654 					     cb,
655 					     NETLBL_NLTYPE_CIPSOV4) < 0)
656 			goto protocols_return;
657 		protos_sent++;
658 	}
659 
660 protocols_return:
661 	cb->args[0] = protos_sent;
662 	return skb->len;
663 }
664 
665 /**
666  * netlbl_mgmt_version - Handle a VERSION message
667  * @skb: the NETLINK buffer
668  * @info: the Generic NETLINK info block
669  *
670  * Description:
671  * Process a user generated VERSION message and respond accordingly.  Returns
672  * zero on success, negative values on failure.
673  *
674  */
675 static int netlbl_mgmt_version(struct sk_buff *skb, struct genl_info *info)
676 {
677 	int ret_val = -ENOMEM;
678 	struct sk_buff *ans_skb = NULL;
679 	void *data;
680 
681 	ans_skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
682 	if (ans_skb == NULL)
683 		return -ENOMEM;
684 	data = genlmsg_put_reply(ans_skb, info, &netlbl_mgmt_gnl_family,
685 				 0, NLBL_MGMT_C_VERSION);
686 	if (data == NULL)
687 		goto version_failure;
688 
689 	ret_val = nla_put_u32(ans_skb,
690 			      NLBL_MGMT_A_VERSION,
691 			      NETLBL_PROTO_VERSION);
692 	if (ret_val != 0)
693 		goto version_failure;
694 
695 	genlmsg_end(ans_skb, data);
696 	return genlmsg_reply(ans_skb, info);
697 
698 version_failure:
699 	kfree_skb(ans_skb);
700 	return ret_val;
701 }
702 
703 
704 /*
705  * NetLabel Generic NETLINK Command Definitions
706  */
707 
708 static const struct genl_ops netlbl_mgmt_genl_ops[] = {
709 	{
710 	.cmd = NLBL_MGMT_C_ADD,
711 	.flags = GENL_ADMIN_PERM,
712 	.policy = netlbl_mgmt_genl_policy,
713 	.doit = netlbl_mgmt_add,
714 	.dumpit = NULL,
715 	},
716 	{
717 	.cmd = NLBL_MGMT_C_REMOVE,
718 	.flags = GENL_ADMIN_PERM,
719 	.policy = netlbl_mgmt_genl_policy,
720 	.doit = netlbl_mgmt_remove,
721 	.dumpit = NULL,
722 	},
723 	{
724 	.cmd = NLBL_MGMT_C_LISTALL,
725 	.flags = 0,
726 	.policy = netlbl_mgmt_genl_policy,
727 	.doit = NULL,
728 	.dumpit = netlbl_mgmt_listall,
729 	},
730 	{
731 	.cmd = NLBL_MGMT_C_ADDDEF,
732 	.flags = GENL_ADMIN_PERM,
733 	.policy = netlbl_mgmt_genl_policy,
734 	.doit = netlbl_mgmt_adddef,
735 	.dumpit = NULL,
736 	},
737 	{
738 	.cmd = NLBL_MGMT_C_REMOVEDEF,
739 	.flags = GENL_ADMIN_PERM,
740 	.policy = netlbl_mgmt_genl_policy,
741 	.doit = netlbl_mgmt_removedef,
742 	.dumpit = NULL,
743 	},
744 	{
745 	.cmd = NLBL_MGMT_C_LISTDEF,
746 	.flags = 0,
747 	.policy = netlbl_mgmt_genl_policy,
748 	.doit = netlbl_mgmt_listdef,
749 	.dumpit = NULL,
750 	},
751 	{
752 	.cmd = NLBL_MGMT_C_PROTOCOLS,
753 	.flags = 0,
754 	.policy = netlbl_mgmt_genl_policy,
755 	.doit = NULL,
756 	.dumpit = netlbl_mgmt_protocols,
757 	},
758 	{
759 	.cmd = NLBL_MGMT_C_VERSION,
760 	.flags = 0,
761 	.policy = netlbl_mgmt_genl_policy,
762 	.doit = netlbl_mgmt_version,
763 	.dumpit = NULL,
764 	},
765 };
766 
767 /*
768  * NetLabel Generic NETLINK Protocol Functions
769  */
770 
771 /**
772  * netlbl_mgmt_genl_init - Register the NetLabel management component
773  *
774  * Description:
775  * Register the NetLabel management component with the Generic NETLINK
776  * mechanism.  Returns zero on success, negative values on failure.
777  *
778  */
779 int __init netlbl_mgmt_genl_init(void)
780 {
781 	return genl_register_family_with_ops(&netlbl_mgmt_gnl_family,
782 					     netlbl_mgmt_genl_ops);
783 }
784