xref: /openbmc/linux/net/netlabel/netlabel_mgmt.c (revision b34e08d5)
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_dom_map *entry = NULL;
97 	struct netlbl_domaddr_map *addrmap = NULL;
98 	struct cipso_v4_doi *cipsov4 = NULL;
99 	u32 tmp_val;
100 
101 	entry = kzalloc(sizeof(*entry), GFP_KERNEL);
102 	if (entry == NULL) {
103 		ret_val = -ENOMEM;
104 		goto add_failure;
105 	}
106 	entry->def.type = nla_get_u32(info->attrs[NLBL_MGMT_A_PROTOCOL]);
107 	if (info->attrs[NLBL_MGMT_A_DOMAIN]) {
108 		size_t tmp_size = nla_len(info->attrs[NLBL_MGMT_A_DOMAIN]);
109 		entry->domain = kmalloc(tmp_size, GFP_KERNEL);
110 		if (entry->domain == NULL) {
111 			ret_val = -ENOMEM;
112 			goto add_failure;
113 		}
114 		nla_strlcpy(entry->domain,
115 			    info->attrs[NLBL_MGMT_A_DOMAIN], tmp_size);
116 	}
117 
118 	/* NOTE: internally we allow/use a entry->def.type value of
119 	 *       NETLBL_NLTYPE_ADDRSELECT but we don't currently allow users
120 	 *       to pass that as a protocol value because we need to know the
121 	 *       "real" protocol */
122 
123 	switch (entry->def.type) {
124 	case NETLBL_NLTYPE_UNLABELED:
125 		break;
126 	case NETLBL_NLTYPE_CIPSOV4:
127 		if (!info->attrs[NLBL_MGMT_A_CV4DOI])
128 			goto add_failure;
129 
130 		tmp_val = nla_get_u32(info->attrs[NLBL_MGMT_A_CV4DOI]);
131 		cipsov4 = cipso_v4_doi_getdef(tmp_val);
132 		if (cipsov4 == NULL)
133 			goto add_failure;
134 		entry->def.cipso = cipsov4;
135 		break;
136 	default:
137 		goto add_failure;
138 	}
139 
140 	if (info->attrs[NLBL_MGMT_A_IPV4ADDR]) {
141 		struct in_addr *addr;
142 		struct in_addr *mask;
143 		struct netlbl_domaddr4_map *map;
144 
145 		addrmap = kzalloc(sizeof(*addrmap), GFP_KERNEL);
146 		if (addrmap == NULL) {
147 			ret_val = -ENOMEM;
148 			goto add_failure;
149 		}
150 		INIT_LIST_HEAD(&addrmap->list4);
151 		INIT_LIST_HEAD(&addrmap->list6);
152 
153 		if (nla_len(info->attrs[NLBL_MGMT_A_IPV4ADDR]) !=
154 		    sizeof(struct in_addr)) {
155 			ret_val = -EINVAL;
156 			goto add_failure;
157 		}
158 		if (nla_len(info->attrs[NLBL_MGMT_A_IPV4MASK]) !=
159 		    sizeof(struct in_addr)) {
160 			ret_val = -EINVAL;
161 			goto add_failure;
162 		}
163 		addr = nla_data(info->attrs[NLBL_MGMT_A_IPV4ADDR]);
164 		mask = nla_data(info->attrs[NLBL_MGMT_A_IPV4MASK]);
165 
166 		map = kzalloc(sizeof(*map), GFP_KERNEL);
167 		if (map == NULL) {
168 			ret_val = -ENOMEM;
169 			goto add_failure;
170 		}
171 		map->list.addr = addr->s_addr & mask->s_addr;
172 		map->list.mask = mask->s_addr;
173 		map->list.valid = 1;
174 		map->def.type = entry->def.type;
175 		if (cipsov4)
176 			map->def.cipso = cipsov4;
177 
178 		ret_val = netlbl_af4list_add(&map->list, &addrmap->list4);
179 		if (ret_val != 0) {
180 			kfree(map);
181 			goto add_failure;
182 		}
183 
184 		entry->def.type = NETLBL_NLTYPE_ADDRSELECT;
185 		entry->def.addrsel = addrmap;
186 #if IS_ENABLED(CONFIG_IPV6)
187 	} else if (info->attrs[NLBL_MGMT_A_IPV6ADDR]) {
188 		struct in6_addr *addr;
189 		struct in6_addr *mask;
190 		struct netlbl_domaddr6_map *map;
191 
192 		addrmap = kzalloc(sizeof(*addrmap), GFP_KERNEL);
193 		if (addrmap == NULL) {
194 			ret_val = -ENOMEM;
195 			goto add_failure;
196 		}
197 		INIT_LIST_HEAD(&addrmap->list4);
198 		INIT_LIST_HEAD(&addrmap->list6);
199 
200 		if (nla_len(info->attrs[NLBL_MGMT_A_IPV6ADDR]) !=
201 		    sizeof(struct in6_addr)) {
202 			ret_val = -EINVAL;
203 			goto add_failure;
204 		}
205 		if (nla_len(info->attrs[NLBL_MGMT_A_IPV6MASK]) !=
206 		    sizeof(struct in6_addr)) {
207 			ret_val = -EINVAL;
208 			goto add_failure;
209 		}
210 		addr = nla_data(info->attrs[NLBL_MGMT_A_IPV6ADDR]);
211 		mask = nla_data(info->attrs[NLBL_MGMT_A_IPV6MASK]);
212 
213 		map = kzalloc(sizeof(*map), GFP_KERNEL);
214 		if (map == NULL) {
215 			ret_val = -ENOMEM;
216 			goto add_failure;
217 		}
218 		map->list.addr = *addr;
219 		map->list.addr.s6_addr32[0] &= mask->s6_addr32[0];
220 		map->list.addr.s6_addr32[1] &= mask->s6_addr32[1];
221 		map->list.addr.s6_addr32[2] &= mask->s6_addr32[2];
222 		map->list.addr.s6_addr32[3] &= mask->s6_addr32[3];
223 		map->list.mask = *mask;
224 		map->list.valid = 1;
225 		map->def.type = entry->def.type;
226 
227 		ret_val = netlbl_af6list_add(&map->list, &addrmap->list6);
228 		if (ret_val != 0) {
229 			kfree(map);
230 			goto add_failure;
231 		}
232 
233 		entry->def.type = NETLBL_NLTYPE_ADDRSELECT;
234 		entry->def.addrsel = addrmap;
235 #endif /* IPv6 */
236 	}
237 
238 	ret_val = netlbl_domhsh_add(entry, audit_info);
239 	if (ret_val != 0)
240 		goto add_failure;
241 
242 	return 0;
243 
244 add_failure:
245 	if (cipsov4)
246 		cipso_v4_doi_putdef(cipsov4);
247 	if (entry)
248 		kfree(entry->domain);
249 	kfree(addrmap);
250 	kfree(entry);
251 	return ret_val;
252 }
253 
254 /**
255  * netlbl_mgmt_listentry - List a NetLabel/LSM domain map entry
256  * @skb: the NETLINK buffer
257  * @entry: the map entry
258  *
259  * Description:
260  * This function is a helper function used by the LISTALL and LISTDEF command
261  * handlers.  The caller is responsible for ensuring that the RCU read lock
262  * is held.  Returns zero on success, negative values on failure.
263  *
264  */
265 static int netlbl_mgmt_listentry(struct sk_buff *skb,
266 				 struct netlbl_dom_map *entry)
267 {
268 	int ret_val = 0;
269 	struct nlattr *nla_a;
270 	struct nlattr *nla_b;
271 	struct netlbl_af4list *iter4;
272 #if IS_ENABLED(CONFIG_IPV6)
273 	struct netlbl_af6list *iter6;
274 #endif
275 
276 	if (entry->domain != NULL) {
277 		ret_val = nla_put_string(skb,
278 					 NLBL_MGMT_A_DOMAIN, entry->domain);
279 		if (ret_val != 0)
280 			return ret_val;
281 	}
282 
283 	switch (entry->def.type) {
284 	case NETLBL_NLTYPE_ADDRSELECT:
285 		nla_a = nla_nest_start(skb, NLBL_MGMT_A_SELECTORLIST);
286 		if (nla_a == NULL)
287 			return -ENOMEM;
288 
289 		netlbl_af4list_foreach_rcu(iter4, &entry->def.addrsel->list4) {
290 			struct netlbl_domaddr4_map *map4;
291 			struct in_addr addr_struct;
292 
293 			nla_b = nla_nest_start(skb, NLBL_MGMT_A_ADDRSELECTOR);
294 			if (nla_b == NULL)
295 				return -ENOMEM;
296 
297 			addr_struct.s_addr = iter4->addr;
298 			ret_val = nla_put(skb, NLBL_MGMT_A_IPV4ADDR,
299 					  sizeof(struct in_addr),
300 					  &addr_struct);
301 			if (ret_val != 0)
302 				return ret_val;
303 			addr_struct.s_addr = iter4->mask;
304 			ret_val = nla_put(skb, NLBL_MGMT_A_IPV4MASK,
305 					  sizeof(struct in_addr),
306 					  &addr_struct);
307 			if (ret_val != 0)
308 				return ret_val;
309 			map4 = netlbl_domhsh_addr4_entry(iter4);
310 			ret_val = nla_put_u32(skb, NLBL_MGMT_A_PROTOCOL,
311 					      map4->def.type);
312 			if (ret_val != 0)
313 				return ret_val;
314 			switch (map4->def.type) {
315 			case NETLBL_NLTYPE_CIPSOV4:
316 				ret_val = nla_put_u32(skb, NLBL_MGMT_A_CV4DOI,
317 						      map4->def.cipso->doi);
318 				if (ret_val != 0)
319 					return ret_val;
320 				break;
321 			}
322 
323 			nla_nest_end(skb, nla_b);
324 		}
325 #if IS_ENABLED(CONFIG_IPV6)
326 		netlbl_af6list_foreach_rcu(iter6, &entry->def.addrsel->list6) {
327 			struct netlbl_domaddr6_map *map6;
328 
329 			nla_b = nla_nest_start(skb, NLBL_MGMT_A_ADDRSELECTOR);
330 			if (nla_b == NULL)
331 				return -ENOMEM;
332 
333 			ret_val = nla_put(skb, NLBL_MGMT_A_IPV6ADDR,
334 					  sizeof(struct in6_addr),
335 					  &iter6->addr);
336 			if (ret_val != 0)
337 				return ret_val;
338 			ret_val = nla_put(skb, NLBL_MGMT_A_IPV6MASK,
339 					  sizeof(struct in6_addr),
340 					  &iter6->mask);
341 			if (ret_val != 0)
342 				return ret_val;
343 			map6 = netlbl_domhsh_addr6_entry(iter6);
344 			ret_val = nla_put_u32(skb, NLBL_MGMT_A_PROTOCOL,
345 					      map6->def.type);
346 			if (ret_val != 0)
347 				return ret_val;
348 
349 			nla_nest_end(skb, nla_b);
350 		}
351 #endif /* IPv6 */
352 
353 		nla_nest_end(skb, nla_a);
354 		break;
355 	case NETLBL_NLTYPE_UNLABELED:
356 		ret_val = nla_put_u32(skb,NLBL_MGMT_A_PROTOCOL,entry->def.type);
357 		break;
358 	case NETLBL_NLTYPE_CIPSOV4:
359 		ret_val = nla_put_u32(skb,NLBL_MGMT_A_PROTOCOL,entry->def.type);
360 		if (ret_val != 0)
361 			return ret_val;
362 		ret_val = nla_put_u32(skb, NLBL_MGMT_A_CV4DOI,
363 				      entry->def.cipso->doi);
364 		break;
365 	}
366 
367 	return ret_val;
368 }
369 
370 /*
371  * NetLabel Command Handlers
372  */
373 
374 /**
375  * netlbl_mgmt_add - Handle an ADD message
376  * @skb: the NETLINK buffer
377  * @info: the Generic NETLINK info block
378  *
379  * Description:
380  * Process a user generated ADD message and add the domains from the message
381  * to the hash table.  See netlabel.h for a description of the message format.
382  * Returns zero on success, negative values on failure.
383  *
384  */
385 static int netlbl_mgmt_add(struct sk_buff *skb, struct genl_info *info)
386 {
387 	struct netlbl_audit audit_info;
388 
389 	if ((!info->attrs[NLBL_MGMT_A_DOMAIN]) ||
390 	    (!info->attrs[NLBL_MGMT_A_PROTOCOL]) ||
391 	    (info->attrs[NLBL_MGMT_A_IPV4ADDR] &&
392 	     info->attrs[NLBL_MGMT_A_IPV6ADDR]) ||
393 	    (info->attrs[NLBL_MGMT_A_IPV4MASK] &&
394 	     info->attrs[NLBL_MGMT_A_IPV6MASK]) ||
395 	    ((info->attrs[NLBL_MGMT_A_IPV4ADDR] != NULL) ^
396 	     (info->attrs[NLBL_MGMT_A_IPV4MASK] != NULL)) ||
397 	    ((info->attrs[NLBL_MGMT_A_IPV6ADDR] != NULL) ^
398 	     (info->attrs[NLBL_MGMT_A_IPV6MASK] != NULL)))
399 		return -EINVAL;
400 
401 	netlbl_netlink_auditinfo(skb, &audit_info);
402 
403 	return netlbl_mgmt_add_common(info, &audit_info);
404 }
405 
406 /**
407  * netlbl_mgmt_remove - Handle a REMOVE message
408  * @skb: the NETLINK buffer
409  * @info: the Generic NETLINK info block
410  *
411  * Description:
412  * Process a user generated REMOVE message and remove the specified domain
413  * mappings.  Returns zero on success, negative values on failure.
414  *
415  */
416 static int netlbl_mgmt_remove(struct sk_buff *skb, struct genl_info *info)
417 {
418 	char *domain;
419 	struct netlbl_audit audit_info;
420 
421 	if (!info->attrs[NLBL_MGMT_A_DOMAIN])
422 		return -EINVAL;
423 
424 	netlbl_netlink_auditinfo(skb, &audit_info);
425 
426 	domain = nla_data(info->attrs[NLBL_MGMT_A_DOMAIN]);
427 	return netlbl_domhsh_remove(domain, &audit_info);
428 }
429 
430 /**
431  * netlbl_mgmt_listall_cb - netlbl_domhsh_walk() callback for LISTALL
432  * @entry: the domain mapping hash table entry
433  * @arg: the netlbl_domhsh_walk_arg structure
434  *
435  * Description:
436  * This function is designed to be used as a callback to the
437  * netlbl_domhsh_walk() function for use in generating a response for a LISTALL
438  * message.  Returns the size of the message on success, negative values on
439  * failure.
440  *
441  */
442 static int netlbl_mgmt_listall_cb(struct netlbl_dom_map *entry, void *arg)
443 {
444 	int ret_val = -ENOMEM;
445 	struct netlbl_domhsh_walk_arg *cb_arg = arg;
446 	void *data;
447 
448 	data = genlmsg_put(cb_arg->skb, NETLINK_CB(cb_arg->nl_cb->skb).portid,
449 			   cb_arg->seq, &netlbl_mgmt_gnl_family,
450 			   NLM_F_MULTI, NLBL_MGMT_C_LISTALL);
451 	if (data == NULL)
452 		goto listall_cb_failure;
453 
454 	ret_val = netlbl_mgmt_listentry(cb_arg->skb, entry);
455 	if (ret_val != 0)
456 		goto listall_cb_failure;
457 
458 	cb_arg->seq++;
459 	return genlmsg_end(cb_arg->skb, data);
460 
461 listall_cb_failure:
462 	genlmsg_cancel(cb_arg->skb, data);
463 	return ret_val;
464 }
465 
466 /**
467  * netlbl_mgmt_listall - Handle a LISTALL message
468  * @skb: the NETLINK buffer
469  * @cb: the NETLINK callback
470  *
471  * Description:
472  * Process a user generated LISTALL message and dumps the domain hash table in
473  * a form suitable for use in a kernel generated LISTALL message.  Returns zero
474  * on success, negative values on failure.
475  *
476  */
477 static int netlbl_mgmt_listall(struct sk_buff *skb,
478 			       struct netlink_callback *cb)
479 {
480 	struct netlbl_domhsh_walk_arg cb_arg;
481 	u32 skip_bkt = cb->args[0];
482 	u32 skip_chain = cb->args[1];
483 
484 	cb_arg.nl_cb = cb;
485 	cb_arg.skb = skb;
486 	cb_arg.seq = cb->nlh->nlmsg_seq;
487 
488 	netlbl_domhsh_walk(&skip_bkt,
489 			   &skip_chain,
490 			   netlbl_mgmt_listall_cb,
491 			   &cb_arg);
492 
493 	cb->args[0] = skip_bkt;
494 	cb->args[1] = skip_chain;
495 	return skb->len;
496 }
497 
498 /**
499  * netlbl_mgmt_adddef - Handle an ADDDEF message
500  * @skb: the NETLINK buffer
501  * @info: the Generic NETLINK info block
502  *
503  * Description:
504  * Process a user generated ADDDEF message and respond accordingly.  Returns
505  * zero on success, negative values on failure.
506  *
507  */
508 static int netlbl_mgmt_adddef(struct sk_buff *skb, struct genl_info *info)
509 {
510 	struct netlbl_audit audit_info;
511 
512 	if ((!info->attrs[NLBL_MGMT_A_PROTOCOL]) ||
513 	    (info->attrs[NLBL_MGMT_A_IPV4ADDR] &&
514 	     info->attrs[NLBL_MGMT_A_IPV6ADDR]) ||
515 	    (info->attrs[NLBL_MGMT_A_IPV4MASK] &&
516 	     info->attrs[NLBL_MGMT_A_IPV6MASK]) ||
517 	    ((info->attrs[NLBL_MGMT_A_IPV4ADDR] != NULL) ^
518 	     (info->attrs[NLBL_MGMT_A_IPV4MASK] != NULL)) ||
519 	    ((info->attrs[NLBL_MGMT_A_IPV6ADDR] != NULL) ^
520 	     (info->attrs[NLBL_MGMT_A_IPV6MASK] != NULL)))
521 		return -EINVAL;
522 
523 	netlbl_netlink_auditinfo(skb, &audit_info);
524 
525 	return netlbl_mgmt_add_common(info, &audit_info);
526 }
527 
528 /**
529  * netlbl_mgmt_removedef - Handle a REMOVEDEF message
530  * @skb: the NETLINK buffer
531  * @info: the Generic NETLINK info block
532  *
533  * Description:
534  * Process a user generated REMOVEDEF message and remove the default domain
535  * mapping.  Returns zero on success, negative values on failure.
536  *
537  */
538 static int netlbl_mgmt_removedef(struct sk_buff *skb, struct genl_info *info)
539 {
540 	struct netlbl_audit audit_info;
541 
542 	netlbl_netlink_auditinfo(skb, &audit_info);
543 
544 	return netlbl_domhsh_remove_default(&audit_info);
545 }
546 
547 /**
548  * netlbl_mgmt_listdef - Handle a LISTDEF message
549  * @skb: the NETLINK buffer
550  * @info: the Generic NETLINK info block
551  *
552  * Description:
553  * Process a user generated LISTDEF message and dumps the default domain
554  * mapping in a form suitable for use in a kernel generated LISTDEF message.
555  * Returns zero on success, negative values on failure.
556  *
557  */
558 static int netlbl_mgmt_listdef(struct sk_buff *skb, struct genl_info *info)
559 {
560 	int ret_val = -ENOMEM;
561 	struct sk_buff *ans_skb = NULL;
562 	void *data;
563 	struct netlbl_dom_map *entry;
564 
565 	ans_skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
566 	if (ans_skb == NULL)
567 		return -ENOMEM;
568 	data = genlmsg_put_reply(ans_skb, info, &netlbl_mgmt_gnl_family,
569 				 0, NLBL_MGMT_C_LISTDEF);
570 	if (data == NULL)
571 		goto listdef_failure;
572 
573 	rcu_read_lock();
574 	entry = netlbl_domhsh_getentry(NULL);
575 	if (entry == NULL) {
576 		ret_val = -ENOENT;
577 		goto listdef_failure_lock;
578 	}
579 	ret_val = netlbl_mgmt_listentry(ans_skb, entry);
580 	rcu_read_unlock();
581 	if (ret_val != 0)
582 		goto listdef_failure;
583 
584 	genlmsg_end(ans_skb, data);
585 	return genlmsg_reply(ans_skb, info);
586 
587 listdef_failure_lock:
588 	rcu_read_unlock();
589 listdef_failure:
590 	kfree_skb(ans_skb);
591 	return ret_val;
592 }
593 
594 /**
595  * netlbl_mgmt_protocols_cb - Write an individual PROTOCOL message response
596  * @skb: the skb to write to
597  * @cb: the NETLINK callback
598  * @protocol: the NetLabel protocol to use in the message
599  *
600  * Description:
601  * This function is to be used in conjunction with netlbl_mgmt_protocols() to
602  * answer a application's PROTOCOLS message.  Returns the size of the message
603  * on success, negative values on failure.
604  *
605  */
606 static int netlbl_mgmt_protocols_cb(struct sk_buff *skb,
607 				    struct netlink_callback *cb,
608 				    u32 protocol)
609 {
610 	int ret_val = -ENOMEM;
611 	void *data;
612 
613 	data = genlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq,
614 			   &netlbl_mgmt_gnl_family, NLM_F_MULTI,
615 			   NLBL_MGMT_C_PROTOCOLS);
616 	if (data == NULL)
617 		goto protocols_cb_failure;
618 
619 	ret_val = nla_put_u32(skb, NLBL_MGMT_A_PROTOCOL, protocol);
620 	if (ret_val != 0)
621 		goto protocols_cb_failure;
622 
623 	return genlmsg_end(skb, data);
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