xref: /openbmc/linux/net/netlabel/netlabel_mgmt.c (revision 92a2c6b2)
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(skb, NLBL_MGMT_A_IPV4ADDR,
297 					  sizeof(struct in_addr),
298 					  &addr_struct);
299 			if (ret_val != 0)
300 				return ret_val;
301 			addr_struct.s_addr = iter4->mask;
302 			ret_val = nla_put(skb, NLBL_MGMT_A_IPV4MASK,
303 					  sizeof(struct in_addr),
304 					  &addr_struct);
305 			if (ret_val != 0)
306 				return ret_val;
307 			map4 = netlbl_domhsh_addr4_entry(iter4);
308 			ret_val = nla_put_u32(skb, NLBL_MGMT_A_PROTOCOL,
309 					      map4->def.type);
310 			if (ret_val != 0)
311 				return ret_val;
312 			switch (map4->def.type) {
313 			case NETLBL_NLTYPE_CIPSOV4:
314 				ret_val = nla_put_u32(skb, NLBL_MGMT_A_CV4DOI,
315 						      map4->def.cipso->doi);
316 				if (ret_val != 0)
317 					return ret_val;
318 				break;
319 			}
320 
321 			nla_nest_end(skb, nla_b);
322 		}
323 #if IS_ENABLED(CONFIG_IPV6)
324 		netlbl_af6list_foreach_rcu(iter6, &entry->def.addrsel->list6) {
325 			struct netlbl_domaddr6_map *map6;
326 
327 			nla_b = nla_nest_start(skb, NLBL_MGMT_A_ADDRSELECTOR);
328 			if (nla_b == NULL)
329 				return -ENOMEM;
330 
331 			ret_val = nla_put(skb, NLBL_MGMT_A_IPV6ADDR,
332 					  sizeof(struct in6_addr),
333 					  &iter6->addr);
334 			if (ret_val != 0)
335 				return ret_val;
336 			ret_val = nla_put(skb, NLBL_MGMT_A_IPV6MASK,
337 					  sizeof(struct in6_addr),
338 					  &iter6->mask);
339 			if (ret_val != 0)
340 				return ret_val;
341 			map6 = netlbl_domhsh_addr6_entry(iter6);
342 			ret_val = nla_put_u32(skb, NLBL_MGMT_A_PROTOCOL,
343 					      map6->def.type);
344 			if (ret_val != 0)
345 				return ret_val;
346 
347 			nla_nest_end(skb, nla_b);
348 		}
349 #endif /* IPv6 */
350 
351 		nla_nest_end(skb, nla_a);
352 		break;
353 	case NETLBL_NLTYPE_UNLABELED:
354 		ret_val = nla_put_u32(skb,NLBL_MGMT_A_PROTOCOL,entry->def.type);
355 		break;
356 	case NETLBL_NLTYPE_CIPSOV4:
357 		ret_val = nla_put_u32(skb,NLBL_MGMT_A_PROTOCOL,entry->def.type);
358 		if (ret_val != 0)
359 			return ret_val;
360 		ret_val = nla_put_u32(skb, NLBL_MGMT_A_CV4DOI,
361 				      entry->def.cipso->doi);
362 		break;
363 	}
364 
365 	return ret_val;
366 }
367 
368 /*
369  * NetLabel Command Handlers
370  */
371 
372 /**
373  * netlbl_mgmt_add - Handle an ADD message
374  * @skb: the NETLINK buffer
375  * @info: the Generic NETLINK info block
376  *
377  * Description:
378  * Process a user generated ADD message and add the domains from the message
379  * to the hash table.  See netlabel.h for a description of the message format.
380  * Returns zero on success, negative values on failure.
381  *
382  */
383 static int netlbl_mgmt_add(struct sk_buff *skb, struct genl_info *info)
384 {
385 	struct netlbl_audit audit_info;
386 
387 	if ((!info->attrs[NLBL_MGMT_A_DOMAIN]) ||
388 	    (!info->attrs[NLBL_MGMT_A_PROTOCOL]) ||
389 	    (info->attrs[NLBL_MGMT_A_IPV4ADDR] &&
390 	     info->attrs[NLBL_MGMT_A_IPV6ADDR]) ||
391 	    (info->attrs[NLBL_MGMT_A_IPV4MASK] &&
392 	     info->attrs[NLBL_MGMT_A_IPV6MASK]) ||
393 	    ((info->attrs[NLBL_MGMT_A_IPV4ADDR] != NULL) ^
394 	     (info->attrs[NLBL_MGMT_A_IPV4MASK] != NULL)) ||
395 	    ((info->attrs[NLBL_MGMT_A_IPV6ADDR] != NULL) ^
396 	     (info->attrs[NLBL_MGMT_A_IPV6MASK] != NULL)))
397 		return -EINVAL;
398 
399 	netlbl_netlink_auditinfo(skb, &audit_info);
400 
401 	return netlbl_mgmt_add_common(info, &audit_info);
402 }
403 
404 /**
405  * netlbl_mgmt_remove - Handle a REMOVE message
406  * @skb: the NETLINK buffer
407  * @info: the Generic NETLINK info block
408  *
409  * Description:
410  * Process a user generated REMOVE message and remove the specified domain
411  * mappings.  Returns zero on success, negative values on failure.
412  *
413  */
414 static int netlbl_mgmt_remove(struct sk_buff *skb, struct genl_info *info)
415 {
416 	char *domain;
417 	struct netlbl_audit audit_info;
418 
419 	if (!info->attrs[NLBL_MGMT_A_DOMAIN])
420 		return -EINVAL;
421 
422 	netlbl_netlink_auditinfo(skb, &audit_info);
423 
424 	domain = nla_data(info->attrs[NLBL_MGMT_A_DOMAIN]);
425 	return netlbl_domhsh_remove(domain, &audit_info);
426 }
427 
428 /**
429  * netlbl_mgmt_listall_cb - netlbl_domhsh_walk() callback for LISTALL
430  * @entry: the domain mapping hash table entry
431  * @arg: the netlbl_domhsh_walk_arg structure
432  *
433  * Description:
434  * This function is designed to be used as a callback to the
435  * netlbl_domhsh_walk() function for use in generating a response for a LISTALL
436  * message.  Returns the size of the message on success, negative values on
437  * failure.
438  *
439  */
440 static int netlbl_mgmt_listall_cb(struct netlbl_dom_map *entry, void *arg)
441 {
442 	int ret_val = -ENOMEM;
443 	struct netlbl_domhsh_walk_arg *cb_arg = arg;
444 	void *data;
445 
446 	data = genlmsg_put(cb_arg->skb, NETLINK_CB(cb_arg->nl_cb->skb).portid,
447 			   cb_arg->seq, &netlbl_mgmt_gnl_family,
448 			   NLM_F_MULTI, NLBL_MGMT_C_LISTALL);
449 	if (data == NULL)
450 		goto listall_cb_failure;
451 
452 	ret_val = netlbl_mgmt_listentry(cb_arg->skb, entry);
453 	if (ret_val != 0)
454 		goto listall_cb_failure;
455 
456 	cb_arg->seq++;
457 	genlmsg_end(cb_arg->skb, data);
458 	return 0;
459 
460 listall_cb_failure:
461 	genlmsg_cancel(cb_arg->skb, data);
462 	return ret_val;
463 }
464 
465 /**
466  * netlbl_mgmt_listall - Handle a LISTALL message
467  * @skb: the NETLINK buffer
468  * @cb: the NETLINK callback
469  *
470  * Description:
471  * Process a user generated LISTALL message and dumps the domain hash table in
472  * a form suitable for use in a kernel generated LISTALL message.  Returns zero
473  * on success, negative values on failure.
474  *
475  */
476 static int netlbl_mgmt_listall(struct sk_buff *skb,
477 			       struct netlink_callback *cb)
478 {
479 	struct netlbl_domhsh_walk_arg cb_arg;
480 	u32 skip_bkt = cb->args[0];
481 	u32 skip_chain = cb->args[1];
482 
483 	cb_arg.nl_cb = cb;
484 	cb_arg.skb = skb;
485 	cb_arg.seq = cb->nlh->nlmsg_seq;
486 
487 	netlbl_domhsh_walk(&skip_bkt,
488 			   &skip_chain,
489 			   netlbl_mgmt_listall_cb,
490 			   &cb_arg);
491 
492 	cb->args[0] = skip_bkt;
493 	cb->args[1] = skip_chain;
494 	return skb->len;
495 }
496 
497 /**
498  * netlbl_mgmt_adddef - Handle an ADDDEF message
499  * @skb: the NETLINK buffer
500  * @info: the Generic NETLINK info block
501  *
502  * Description:
503  * Process a user generated ADDDEF message and respond accordingly.  Returns
504  * zero on success, negative values on failure.
505  *
506  */
507 static int netlbl_mgmt_adddef(struct sk_buff *skb, struct genl_info *info)
508 {
509 	struct netlbl_audit audit_info;
510 
511 	if ((!info->attrs[NLBL_MGMT_A_PROTOCOL]) ||
512 	    (info->attrs[NLBL_MGMT_A_IPV4ADDR] &&
513 	     info->attrs[NLBL_MGMT_A_IPV6ADDR]) ||
514 	    (info->attrs[NLBL_MGMT_A_IPV4MASK] &&
515 	     info->attrs[NLBL_MGMT_A_IPV6MASK]) ||
516 	    ((info->attrs[NLBL_MGMT_A_IPV4ADDR] != NULL) ^
517 	     (info->attrs[NLBL_MGMT_A_IPV4MASK] != NULL)) ||
518 	    ((info->attrs[NLBL_MGMT_A_IPV6ADDR] != NULL) ^
519 	     (info->attrs[NLBL_MGMT_A_IPV6MASK] != NULL)))
520 		return -EINVAL;
521 
522 	netlbl_netlink_auditinfo(skb, &audit_info);
523 
524 	return netlbl_mgmt_add_common(info, &audit_info);
525 }
526 
527 /**
528  * netlbl_mgmt_removedef - Handle a REMOVEDEF message
529  * @skb: the NETLINK buffer
530  * @info: the Generic NETLINK info block
531  *
532  * Description:
533  * Process a user generated REMOVEDEF message and remove the default domain
534  * mapping.  Returns zero on success, negative values on failure.
535  *
536  */
537 static int netlbl_mgmt_removedef(struct sk_buff *skb, struct genl_info *info)
538 {
539 	struct netlbl_audit audit_info;
540 
541 	netlbl_netlink_auditinfo(skb, &audit_info);
542 
543 	return netlbl_domhsh_remove_default(&audit_info);
544 }
545 
546 /**
547  * netlbl_mgmt_listdef - Handle a LISTDEF message
548  * @skb: the NETLINK buffer
549  * @info: the Generic NETLINK info block
550  *
551  * Description:
552  * Process a user generated LISTDEF message and dumps the default domain
553  * mapping in a form suitable for use in a kernel generated LISTDEF message.
554  * Returns zero on success, negative values on failure.
555  *
556  */
557 static int netlbl_mgmt_listdef(struct sk_buff *skb, struct genl_info *info)
558 {
559 	int ret_val = -ENOMEM;
560 	struct sk_buff *ans_skb = NULL;
561 	void *data;
562 	struct netlbl_dom_map *entry;
563 
564 	ans_skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
565 	if (ans_skb == NULL)
566 		return -ENOMEM;
567 	data = genlmsg_put_reply(ans_skb, info, &netlbl_mgmt_gnl_family,
568 				 0, NLBL_MGMT_C_LISTDEF);
569 	if (data == NULL)
570 		goto listdef_failure;
571 
572 	rcu_read_lock();
573 	entry = netlbl_domhsh_getentry(NULL);
574 	if (entry == NULL) {
575 		ret_val = -ENOENT;
576 		goto listdef_failure_lock;
577 	}
578 	ret_val = netlbl_mgmt_listentry(ans_skb, entry);
579 	rcu_read_unlock();
580 	if (ret_val != 0)
581 		goto listdef_failure;
582 
583 	genlmsg_end(ans_skb, data);
584 	return genlmsg_reply(ans_skb, info);
585 
586 listdef_failure_lock:
587 	rcu_read_unlock();
588 listdef_failure:
589 	kfree_skb(ans_skb);
590 	return ret_val;
591 }
592 
593 /**
594  * netlbl_mgmt_protocols_cb - Write an individual PROTOCOL message response
595  * @skb: the skb to write to
596  * @cb: the NETLINK callback
597  * @protocol: the NetLabel protocol to use in the message
598  *
599  * Description:
600  * This function is to be used in conjunction with netlbl_mgmt_protocols() to
601  * answer a application's PROTOCOLS message.  Returns the size of the message
602  * on success, negative values on failure.
603  *
604  */
605 static int netlbl_mgmt_protocols_cb(struct sk_buff *skb,
606 				    struct netlink_callback *cb,
607 				    u32 protocol)
608 {
609 	int ret_val = -ENOMEM;
610 	void *data;
611 
612 	data = genlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq,
613 			   &netlbl_mgmt_gnl_family, NLM_F_MULTI,
614 			   NLBL_MGMT_C_PROTOCOLS);
615 	if (data == NULL)
616 		goto protocols_cb_failure;
617 
618 	ret_val = nla_put_u32(skb, NLBL_MGMT_A_PROTOCOL, protocol);
619 	if (ret_val != 0)
620 		goto protocols_cb_failure;
621 
622 	genlmsg_end(skb, data);
623 	return 0;
624 
625 protocols_cb_failure:
626 	genlmsg_cancel(skb, data);
627 	return ret_val;
628 }
629 
630 /**
631  * netlbl_mgmt_protocols - Handle a PROTOCOLS message
632  * @skb: the NETLINK buffer
633  * @cb: the NETLINK callback
634  *
635  * Description:
636  * Process a user generated PROTOCOLS message and respond accordingly.
637  *
638  */
639 static int netlbl_mgmt_protocols(struct sk_buff *skb,
640 				 struct netlink_callback *cb)
641 {
642 	u32 protos_sent = cb->args[0];
643 
644 	if (protos_sent == 0) {
645 		if (netlbl_mgmt_protocols_cb(skb,
646 					     cb,
647 					     NETLBL_NLTYPE_UNLABELED) < 0)
648 			goto protocols_return;
649 		protos_sent++;
650 	}
651 	if (protos_sent == 1) {
652 		if (netlbl_mgmt_protocols_cb(skb,
653 					     cb,
654 					     NETLBL_NLTYPE_CIPSOV4) < 0)
655 			goto protocols_return;
656 		protos_sent++;
657 	}
658 
659 protocols_return:
660 	cb->args[0] = protos_sent;
661 	return skb->len;
662 }
663 
664 /**
665  * netlbl_mgmt_version - Handle a VERSION message
666  * @skb: the NETLINK buffer
667  * @info: the Generic NETLINK info block
668  *
669  * Description:
670  * Process a user generated VERSION message and respond accordingly.  Returns
671  * zero on success, negative values on failure.
672  *
673  */
674 static int netlbl_mgmt_version(struct sk_buff *skb, struct genl_info *info)
675 {
676 	int ret_val = -ENOMEM;
677 	struct sk_buff *ans_skb = NULL;
678 	void *data;
679 
680 	ans_skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
681 	if (ans_skb == NULL)
682 		return -ENOMEM;
683 	data = genlmsg_put_reply(ans_skb, info, &netlbl_mgmt_gnl_family,
684 				 0, NLBL_MGMT_C_VERSION);
685 	if (data == NULL)
686 		goto version_failure;
687 
688 	ret_val = nla_put_u32(ans_skb,
689 			      NLBL_MGMT_A_VERSION,
690 			      NETLBL_PROTO_VERSION);
691 	if (ret_val != 0)
692 		goto version_failure;
693 
694 	genlmsg_end(ans_skb, data);
695 	return genlmsg_reply(ans_skb, info);
696 
697 version_failure:
698 	kfree_skb(ans_skb);
699 	return ret_val;
700 }
701 
702 
703 /*
704  * NetLabel Generic NETLINK Command Definitions
705  */
706 
707 static const struct genl_ops netlbl_mgmt_genl_ops[] = {
708 	{
709 	.cmd = NLBL_MGMT_C_ADD,
710 	.flags = GENL_ADMIN_PERM,
711 	.policy = netlbl_mgmt_genl_policy,
712 	.doit = netlbl_mgmt_add,
713 	.dumpit = NULL,
714 	},
715 	{
716 	.cmd = NLBL_MGMT_C_REMOVE,
717 	.flags = GENL_ADMIN_PERM,
718 	.policy = netlbl_mgmt_genl_policy,
719 	.doit = netlbl_mgmt_remove,
720 	.dumpit = NULL,
721 	},
722 	{
723 	.cmd = NLBL_MGMT_C_LISTALL,
724 	.flags = 0,
725 	.policy = netlbl_mgmt_genl_policy,
726 	.doit = NULL,
727 	.dumpit = netlbl_mgmt_listall,
728 	},
729 	{
730 	.cmd = NLBL_MGMT_C_ADDDEF,
731 	.flags = GENL_ADMIN_PERM,
732 	.policy = netlbl_mgmt_genl_policy,
733 	.doit = netlbl_mgmt_adddef,
734 	.dumpit = NULL,
735 	},
736 	{
737 	.cmd = NLBL_MGMT_C_REMOVEDEF,
738 	.flags = GENL_ADMIN_PERM,
739 	.policy = netlbl_mgmt_genl_policy,
740 	.doit = netlbl_mgmt_removedef,
741 	.dumpit = NULL,
742 	},
743 	{
744 	.cmd = NLBL_MGMT_C_LISTDEF,
745 	.flags = 0,
746 	.policy = netlbl_mgmt_genl_policy,
747 	.doit = netlbl_mgmt_listdef,
748 	.dumpit = NULL,
749 	},
750 	{
751 	.cmd = NLBL_MGMT_C_PROTOCOLS,
752 	.flags = 0,
753 	.policy = netlbl_mgmt_genl_policy,
754 	.doit = NULL,
755 	.dumpit = netlbl_mgmt_protocols,
756 	},
757 	{
758 	.cmd = NLBL_MGMT_C_VERSION,
759 	.flags = 0,
760 	.policy = netlbl_mgmt_genl_policy,
761 	.doit = netlbl_mgmt_version,
762 	.dumpit = NULL,
763 	},
764 };
765 
766 /*
767  * NetLabel Generic NETLINK Protocol Functions
768  */
769 
770 /**
771  * netlbl_mgmt_genl_init - Register the NetLabel management component
772  *
773  * Description:
774  * Register the NetLabel management component with the Generic NETLINK
775  * mechanism.  Returns zero on success, negative values on failure.
776  *
777  */
778 int __init netlbl_mgmt_genl_init(void)
779 {
780 	return genl_register_family_with_ops(&netlbl_mgmt_gnl_family,
781 					     netlbl_mgmt_genl_ops);
782 }
783