xref: /openbmc/linux/net/netlabel/netlabel_mgmt.c (revision 7dd65feb)
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.moore@hp.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 <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 <asm/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->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->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->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->type_def.cipsov4 = 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->type = entry->type;
175 		if (cipsov4)
176 			map->type_def.cipsov4 = 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->type = NETLBL_NLTYPE_ADDRSELECT;
185 		entry->type_def.addrsel = addrmap;
186 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
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 		ipv6_addr_copy(&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 		ipv6_addr_copy(&map->list.mask, mask);
224 		map->list.valid = 1;
225 		map->type = entry->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->type = NETLBL_NLTYPE_ADDRSELECT;
234 		entry->type_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 responsibile 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 defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
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->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,
290 					   &entry->type_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->type);
313 			if (ret_val != 0)
314 				return ret_val;
315 			switch (map4->type) {
316 			case NETLBL_NLTYPE_CIPSOV4:
317 				ret_val = nla_put_u32(skb, NLBL_MGMT_A_CV4DOI,
318 						  map4->type_def.cipsov4->doi);
319 				if (ret_val != 0)
320 					return ret_val;
321 				break;
322 			}
323 
324 			nla_nest_end(skb, nla_b);
325 		}
326 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
327 		netlbl_af6list_foreach_rcu(iter6,
328 					   &entry->type_def.addrsel->list6) {
329 			struct netlbl_domaddr6_map *map6;
330 
331 			nla_b = nla_nest_start(skb, NLBL_MGMT_A_ADDRSELECTOR);
332 			if (nla_b == NULL)
333 				return -ENOMEM;
334 
335 			ret_val = nla_put(skb, NLBL_MGMT_A_IPV6ADDR,
336 					  sizeof(struct in6_addr),
337 					  &iter6->addr);
338 			if (ret_val != 0)
339 				return ret_val;
340 			ret_val = nla_put(skb, NLBL_MGMT_A_IPV6MASK,
341 					  sizeof(struct in6_addr),
342 					  &iter6->mask);
343 			if (ret_val != 0)
344 				return ret_val;
345 			map6 = netlbl_domhsh_addr6_entry(iter6);
346 			ret_val = nla_put_u32(skb, NLBL_MGMT_A_PROTOCOL,
347 					      map6->type);
348 			if (ret_val != 0)
349 				return ret_val;
350 
351 			nla_nest_end(skb, nla_b);
352 		}
353 #endif /* IPv6 */
354 
355 		nla_nest_end(skb, nla_a);
356 		break;
357 	case NETLBL_NLTYPE_UNLABELED:
358 		ret_val = nla_put_u32(skb, NLBL_MGMT_A_PROTOCOL, entry->type);
359 		break;
360 	case NETLBL_NLTYPE_CIPSOV4:
361 		ret_val = nla_put_u32(skb, NLBL_MGMT_A_PROTOCOL, entry->type);
362 		if (ret_val != 0)
363 			return ret_val;
364 		ret_val = nla_put_u32(skb, NLBL_MGMT_A_CV4DOI,
365 				      entry->type_def.cipsov4->doi);
366 		break;
367 	}
368 
369 	return ret_val;
370 }
371 
372 /*
373  * NetLabel Command Handlers
374  */
375 
376 /**
377  * netlbl_mgmt_add - Handle an ADD message
378  * @skb: the NETLINK buffer
379  * @info: the Generic NETLINK info block
380  *
381  * Description:
382  * Process a user generated ADD message and add the domains from the message
383  * to the hash table.  See netlabel.h for a description of the message format.
384  * Returns zero on success, negative values on failure.
385  *
386  */
387 static int netlbl_mgmt_add(struct sk_buff *skb, struct genl_info *info)
388 {
389 	struct netlbl_audit audit_info;
390 
391 	if ((!info->attrs[NLBL_MGMT_A_DOMAIN]) ||
392 	    (!info->attrs[NLBL_MGMT_A_PROTOCOL]) ||
393 	    (info->attrs[NLBL_MGMT_A_IPV4ADDR] &&
394 	     info->attrs[NLBL_MGMT_A_IPV6ADDR]) ||
395 	    (info->attrs[NLBL_MGMT_A_IPV4MASK] &&
396 	     info->attrs[NLBL_MGMT_A_IPV6MASK]) ||
397 	    ((info->attrs[NLBL_MGMT_A_IPV4ADDR] != NULL) ^
398 	     (info->attrs[NLBL_MGMT_A_IPV4MASK] != NULL)) ||
399 	    ((info->attrs[NLBL_MGMT_A_IPV6ADDR] != NULL) ^
400 	     (info->attrs[NLBL_MGMT_A_IPV6MASK] != NULL)))
401 		return -EINVAL;
402 
403 	netlbl_netlink_auditinfo(skb, &audit_info);
404 
405 	return netlbl_mgmt_add_common(info, &audit_info);
406 }
407 
408 /**
409  * netlbl_mgmt_remove - Handle a REMOVE message
410  * @skb: the NETLINK buffer
411  * @info: the Generic NETLINK info block
412  *
413  * Description:
414  * Process a user generated REMOVE message and remove the specified domain
415  * mappings.  Returns zero on success, negative values on failure.
416  *
417  */
418 static int netlbl_mgmt_remove(struct sk_buff *skb, struct genl_info *info)
419 {
420 	char *domain;
421 	struct netlbl_audit audit_info;
422 
423 	if (!info->attrs[NLBL_MGMT_A_DOMAIN])
424 		return -EINVAL;
425 
426 	netlbl_netlink_auditinfo(skb, &audit_info);
427 
428 	domain = nla_data(info->attrs[NLBL_MGMT_A_DOMAIN]);
429 	return netlbl_domhsh_remove(domain, &audit_info);
430 }
431 
432 /**
433  * netlbl_mgmt_listall_cb - netlbl_domhsh_walk() callback for LISTALL
434  * @entry: the domain mapping hash table entry
435  * @arg: the netlbl_domhsh_walk_arg structure
436  *
437  * Description:
438  * This function is designed to be used as a callback to the
439  * netlbl_domhsh_walk() function for use in generating a response for a LISTALL
440  * message.  Returns the size of the message on success, negative values on
441  * failure.
442  *
443  */
444 static int netlbl_mgmt_listall_cb(struct netlbl_dom_map *entry, void *arg)
445 {
446 	int ret_val = -ENOMEM;
447 	struct netlbl_domhsh_walk_arg *cb_arg = arg;
448 	void *data;
449 
450 	data = genlmsg_put(cb_arg->skb, NETLINK_CB(cb_arg->nl_cb->skb).pid,
451 			   cb_arg->seq, &netlbl_mgmt_gnl_family,
452 			   NLM_F_MULTI, NLBL_MGMT_C_LISTALL);
453 	if (data == NULL)
454 		goto listall_cb_failure;
455 
456 	ret_val = netlbl_mgmt_listentry(cb_arg->skb, entry);
457 	if (ret_val != 0)
458 		goto listall_cb_failure;
459 
460 	cb_arg->seq++;
461 	return genlmsg_end(cb_arg->skb, data);
462 
463 listall_cb_failure:
464 	genlmsg_cancel(cb_arg->skb, data);
465 	return ret_val;
466 }
467 
468 /**
469  * netlbl_mgmt_listall - Handle a LISTALL message
470  * @skb: the NETLINK buffer
471  * @cb: the NETLINK callback
472  *
473  * Description:
474  * Process a user generated LISTALL message and dumps the domain hash table in
475  * a form suitable for use in a kernel generated LISTALL message.  Returns zero
476  * on success, negative values on failure.
477  *
478  */
479 static int netlbl_mgmt_listall(struct sk_buff *skb,
480 			       struct netlink_callback *cb)
481 {
482 	struct netlbl_domhsh_walk_arg cb_arg;
483 	u32 skip_bkt = cb->args[0];
484 	u32 skip_chain = cb->args[1];
485 
486 	cb_arg.nl_cb = cb;
487 	cb_arg.skb = skb;
488 	cb_arg.seq = cb->nlh->nlmsg_seq;
489 
490 	netlbl_domhsh_walk(&skip_bkt,
491 			   &skip_chain,
492 			   netlbl_mgmt_listall_cb,
493 			   &cb_arg);
494 
495 	cb->args[0] = skip_bkt;
496 	cb->args[1] = skip_chain;
497 	return skb->len;
498 }
499 
500 /**
501  * netlbl_mgmt_adddef - Handle an ADDDEF message
502  * @skb: the NETLINK buffer
503  * @info: the Generic NETLINK info block
504  *
505  * Description:
506  * Process a user generated ADDDEF message and respond accordingly.  Returns
507  * zero on success, negative values on failure.
508  *
509  */
510 static int netlbl_mgmt_adddef(struct sk_buff *skb, struct genl_info *info)
511 {
512 	struct netlbl_audit audit_info;
513 
514 	if ((!info->attrs[NLBL_MGMT_A_PROTOCOL]) ||
515 	    (info->attrs[NLBL_MGMT_A_IPV4ADDR] &&
516 	     info->attrs[NLBL_MGMT_A_IPV6ADDR]) ||
517 	    (info->attrs[NLBL_MGMT_A_IPV4MASK] &&
518 	     info->attrs[NLBL_MGMT_A_IPV6MASK]) ||
519 	    ((info->attrs[NLBL_MGMT_A_IPV4ADDR] != NULL) ^
520 	     (info->attrs[NLBL_MGMT_A_IPV4MASK] != NULL)) ||
521 	    ((info->attrs[NLBL_MGMT_A_IPV6ADDR] != NULL) ^
522 	     (info->attrs[NLBL_MGMT_A_IPV6MASK] != NULL)))
523 		return -EINVAL;
524 
525 	netlbl_netlink_auditinfo(skb, &audit_info);
526 
527 	return netlbl_mgmt_add_common(info, &audit_info);
528 }
529 
530 /**
531  * netlbl_mgmt_removedef - Handle a REMOVEDEF message
532  * @skb: the NETLINK buffer
533  * @info: the Generic NETLINK info block
534  *
535  * Description:
536  * Process a user generated REMOVEDEF message and remove the default domain
537  * mapping.  Returns zero on success, negative values on failure.
538  *
539  */
540 static int netlbl_mgmt_removedef(struct sk_buff *skb, struct genl_info *info)
541 {
542 	struct netlbl_audit audit_info;
543 
544 	netlbl_netlink_auditinfo(skb, &audit_info);
545 
546 	return netlbl_domhsh_remove_default(&audit_info);
547 }
548 
549 /**
550  * netlbl_mgmt_listdef - Handle a LISTDEF message
551  * @skb: the NETLINK buffer
552  * @info: the Generic NETLINK info block
553  *
554  * Description:
555  * Process a user generated LISTDEF message and dumps the default domain
556  * mapping in a form suitable for use in a kernel generated LISTDEF message.
557  * Returns zero on success, negative values on failure.
558  *
559  */
560 static int netlbl_mgmt_listdef(struct sk_buff *skb, struct genl_info *info)
561 {
562 	int ret_val = -ENOMEM;
563 	struct sk_buff *ans_skb = NULL;
564 	void *data;
565 	struct netlbl_dom_map *entry;
566 
567 	ans_skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
568 	if (ans_skb == NULL)
569 		return -ENOMEM;
570 	data = genlmsg_put_reply(ans_skb, info, &netlbl_mgmt_gnl_family,
571 				 0, NLBL_MGMT_C_LISTDEF);
572 	if (data == NULL)
573 		goto listdef_failure;
574 
575 	rcu_read_lock();
576 	entry = netlbl_domhsh_getentry(NULL);
577 	if (entry == NULL) {
578 		ret_val = -ENOENT;
579 		goto listdef_failure_lock;
580 	}
581 	ret_val = netlbl_mgmt_listentry(ans_skb, entry);
582 	rcu_read_unlock();
583 	if (ret_val != 0)
584 		goto listdef_failure;
585 
586 	genlmsg_end(ans_skb, data);
587 	return genlmsg_reply(ans_skb, info);
588 
589 listdef_failure_lock:
590 	rcu_read_unlock();
591 listdef_failure:
592 	kfree_skb(ans_skb);
593 	return ret_val;
594 }
595 
596 /**
597  * netlbl_mgmt_protocols_cb - Write an individual PROTOCOL message response
598  * @skb: the skb to write to
599  * @cb: the NETLINK callback
600  * @protocol: the NetLabel protocol to use in the message
601  *
602  * Description:
603  * This function is to be used in conjunction with netlbl_mgmt_protocols() to
604  * answer a application's PROTOCOLS message.  Returns the size of the message
605  * on success, negative values on failure.
606  *
607  */
608 static int netlbl_mgmt_protocols_cb(struct sk_buff *skb,
609 				    struct netlink_callback *cb,
610 				    u32 protocol)
611 {
612 	int ret_val = -ENOMEM;
613 	void *data;
614 
615 	data = genlmsg_put(skb, NETLINK_CB(cb->skb).pid, cb->nlh->nlmsg_seq,
616 			   &netlbl_mgmt_gnl_family, NLM_F_MULTI,
617 			   NLBL_MGMT_C_PROTOCOLS);
618 	if (data == NULL)
619 		goto protocols_cb_failure;
620 
621 	ret_val = nla_put_u32(skb, NLBL_MGMT_A_PROTOCOL, protocol);
622 	if (ret_val != 0)
623 		goto protocols_cb_failure;
624 
625 	return genlmsg_end(skb, data);
626 
627 protocols_cb_failure:
628 	genlmsg_cancel(skb, data);
629 	return ret_val;
630 }
631 
632 /**
633  * netlbl_mgmt_protocols - Handle a PROTOCOLS message
634  * @skb: the NETLINK buffer
635  * @cb: the NETLINK callback
636  *
637  * Description:
638  * Process a user generated PROTOCOLS message and respond accordingly.
639  *
640  */
641 static int netlbl_mgmt_protocols(struct sk_buff *skb,
642 				 struct netlink_callback *cb)
643 {
644 	u32 protos_sent = cb->args[0];
645 
646 	if (protos_sent == 0) {
647 		if (netlbl_mgmt_protocols_cb(skb,
648 					     cb,
649 					     NETLBL_NLTYPE_UNLABELED) < 0)
650 			goto protocols_return;
651 		protos_sent++;
652 	}
653 	if (protos_sent == 1) {
654 		if (netlbl_mgmt_protocols_cb(skb,
655 					     cb,
656 					     NETLBL_NLTYPE_CIPSOV4) < 0)
657 			goto protocols_return;
658 		protos_sent++;
659 	}
660 
661 protocols_return:
662 	cb->args[0] = protos_sent;
663 	return skb->len;
664 }
665 
666 /**
667  * netlbl_mgmt_version - Handle a VERSION message
668  * @skb: the NETLINK buffer
669  * @info: the Generic NETLINK info block
670  *
671  * Description:
672  * Process a user generated VERSION message and respond accordingly.  Returns
673  * zero on success, negative values on failure.
674  *
675  */
676 static int netlbl_mgmt_version(struct sk_buff *skb, struct genl_info *info)
677 {
678 	int ret_val = -ENOMEM;
679 	struct sk_buff *ans_skb = NULL;
680 	void *data;
681 
682 	ans_skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
683 	if (ans_skb == NULL)
684 		return -ENOMEM;
685 	data = genlmsg_put_reply(ans_skb, info, &netlbl_mgmt_gnl_family,
686 				 0, NLBL_MGMT_C_VERSION);
687 	if (data == NULL)
688 		goto version_failure;
689 
690 	ret_val = nla_put_u32(ans_skb,
691 			      NLBL_MGMT_A_VERSION,
692 			      NETLBL_PROTO_VERSION);
693 	if (ret_val != 0)
694 		goto version_failure;
695 
696 	genlmsg_end(ans_skb, data);
697 	return genlmsg_reply(ans_skb, info);
698 
699 version_failure:
700 	kfree_skb(ans_skb);
701 	return ret_val;
702 }
703 
704 
705 /*
706  * NetLabel Generic NETLINK Command Definitions
707  */
708 
709 static struct genl_ops netlbl_mgmt_genl_ops[] = {
710 	{
711 	.cmd = NLBL_MGMT_C_ADD,
712 	.flags = GENL_ADMIN_PERM,
713 	.policy = netlbl_mgmt_genl_policy,
714 	.doit = netlbl_mgmt_add,
715 	.dumpit = NULL,
716 	},
717 	{
718 	.cmd = NLBL_MGMT_C_REMOVE,
719 	.flags = GENL_ADMIN_PERM,
720 	.policy = netlbl_mgmt_genl_policy,
721 	.doit = netlbl_mgmt_remove,
722 	.dumpit = NULL,
723 	},
724 	{
725 	.cmd = NLBL_MGMT_C_LISTALL,
726 	.flags = 0,
727 	.policy = netlbl_mgmt_genl_policy,
728 	.doit = NULL,
729 	.dumpit = netlbl_mgmt_listall,
730 	},
731 	{
732 	.cmd = NLBL_MGMT_C_ADDDEF,
733 	.flags = GENL_ADMIN_PERM,
734 	.policy = netlbl_mgmt_genl_policy,
735 	.doit = netlbl_mgmt_adddef,
736 	.dumpit = NULL,
737 	},
738 	{
739 	.cmd = NLBL_MGMT_C_REMOVEDEF,
740 	.flags = GENL_ADMIN_PERM,
741 	.policy = netlbl_mgmt_genl_policy,
742 	.doit = netlbl_mgmt_removedef,
743 	.dumpit = NULL,
744 	},
745 	{
746 	.cmd = NLBL_MGMT_C_LISTDEF,
747 	.flags = 0,
748 	.policy = netlbl_mgmt_genl_policy,
749 	.doit = netlbl_mgmt_listdef,
750 	.dumpit = NULL,
751 	},
752 	{
753 	.cmd = NLBL_MGMT_C_PROTOCOLS,
754 	.flags = 0,
755 	.policy = netlbl_mgmt_genl_policy,
756 	.doit = NULL,
757 	.dumpit = netlbl_mgmt_protocols,
758 	},
759 	{
760 	.cmd = NLBL_MGMT_C_VERSION,
761 	.flags = 0,
762 	.policy = netlbl_mgmt_genl_policy,
763 	.doit = netlbl_mgmt_version,
764 	.dumpit = NULL,
765 	},
766 };
767 
768 /*
769  * NetLabel Generic NETLINK Protocol Functions
770  */
771 
772 /**
773  * netlbl_mgmt_genl_init - Register the NetLabel management component
774  *
775  * Description:
776  * Register the NetLabel management component with the Generic NETLINK
777  * mechanism.  Returns zero on success, negative values on failure.
778  *
779  */
780 int __init netlbl_mgmt_genl_init(void)
781 {
782 	return genl_register_family_with_ops(&netlbl_mgmt_gnl_family,
783 		netlbl_mgmt_genl_ops, ARRAY_SIZE(netlbl_mgmt_genl_ops));
784 }
785