xref: /openbmc/linux/net/netlabel/netlabel_mgmt.c (revision 7fe2f639)
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 <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 <asm/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->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->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->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->type_def.cipsov4 = 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->type = entry->type;
176 		if (cipsov4)
177 			map->type_def.cipsov4 = 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->type = NETLBL_NLTYPE_ADDRSELECT;
186 		entry->type_def.addrsel = addrmap;
187 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
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 		ipv6_addr_copy(&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 		ipv6_addr_copy(&map->list.mask, mask);
225 		map->list.valid = 1;
226 		map->type = entry->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->type = NETLBL_NLTYPE_ADDRSELECT;
235 		entry->type_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 defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
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->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,
291 					   &entry->type_def.addrsel->list4) {
292 			struct netlbl_domaddr4_map *map4;
293 			struct in_addr addr_struct;
294 
295 			nla_b = nla_nest_start(skb, NLBL_MGMT_A_ADDRSELECTOR);
296 			if (nla_b == NULL)
297 				return -ENOMEM;
298 
299 			addr_struct.s_addr = iter4->addr;
300 			ret_val = nla_put(skb, NLBL_MGMT_A_IPV4ADDR,
301 					  sizeof(struct in_addr),
302 					  &addr_struct);
303 			if (ret_val != 0)
304 				return ret_val;
305 			addr_struct.s_addr = iter4->mask;
306 			ret_val = nla_put(skb, NLBL_MGMT_A_IPV4MASK,
307 					  sizeof(struct in_addr),
308 					  &addr_struct);
309 			if (ret_val != 0)
310 				return ret_val;
311 			map4 = netlbl_domhsh_addr4_entry(iter4);
312 			ret_val = nla_put_u32(skb, NLBL_MGMT_A_PROTOCOL,
313 					      map4->type);
314 			if (ret_val != 0)
315 				return ret_val;
316 			switch (map4->type) {
317 			case NETLBL_NLTYPE_CIPSOV4:
318 				ret_val = nla_put_u32(skb, NLBL_MGMT_A_CV4DOI,
319 						  map4->type_def.cipsov4->doi);
320 				if (ret_val != 0)
321 					return ret_val;
322 				break;
323 			}
324 
325 			nla_nest_end(skb, nla_b);
326 		}
327 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
328 		netlbl_af6list_foreach_rcu(iter6,
329 					   &entry->type_def.addrsel->list6) {
330 			struct netlbl_domaddr6_map *map6;
331 
332 			nla_b = nla_nest_start(skb, NLBL_MGMT_A_ADDRSELECTOR);
333 			if (nla_b == NULL)
334 				return -ENOMEM;
335 
336 			ret_val = nla_put(skb, NLBL_MGMT_A_IPV6ADDR,
337 					  sizeof(struct in6_addr),
338 					  &iter6->addr);
339 			if (ret_val != 0)
340 				return ret_val;
341 			ret_val = nla_put(skb, NLBL_MGMT_A_IPV6MASK,
342 					  sizeof(struct in6_addr),
343 					  &iter6->mask);
344 			if (ret_val != 0)
345 				return ret_val;
346 			map6 = netlbl_domhsh_addr6_entry(iter6);
347 			ret_val = nla_put_u32(skb, NLBL_MGMT_A_PROTOCOL,
348 					      map6->type);
349 			if (ret_val != 0)
350 				return ret_val;
351 
352 			nla_nest_end(skb, nla_b);
353 		}
354 #endif /* IPv6 */
355 
356 		nla_nest_end(skb, nla_a);
357 		break;
358 	case NETLBL_NLTYPE_UNLABELED:
359 		ret_val = nla_put_u32(skb, NLBL_MGMT_A_PROTOCOL, entry->type);
360 		break;
361 	case NETLBL_NLTYPE_CIPSOV4:
362 		ret_val = nla_put_u32(skb, NLBL_MGMT_A_PROTOCOL, entry->type);
363 		if (ret_val != 0)
364 			return ret_val;
365 		ret_val = nla_put_u32(skb, NLBL_MGMT_A_CV4DOI,
366 				      entry->type_def.cipsov4->doi);
367 		break;
368 	}
369 
370 	return ret_val;
371 }
372 
373 /*
374  * NetLabel Command Handlers
375  */
376 
377 /**
378  * netlbl_mgmt_add - Handle an ADD message
379  * @skb: the NETLINK buffer
380  * @info: the Generic NETLINK info block
381  *
382  * Description:
383  * Process a user generated ADD message and add the domains from the message
384  * to the hash table.  See netlabel.h for a description of the message format.
385  * Returns zero on success, negative values on failure.
386  *
387  */
388 static int netlbl_mgmt_add(struct sk_buff *skb, struct genl_info *info)
389 {
390 	struct netlbl_audit audit_info;
391 
392 	if ((!info->attrs[NLBL_MGMT_A_DOMAIN]) ||
393 	    (!info->attrs[NLBL_MGMT_A_PROTOCOL]) ||
394 	    (info->attrs[NLBL_MGMT_A_IPV4ADDR] &&
395 	     info->attrs[NLBL_MGMT_A_IPV6ADDR]) ||
396 	    (info->attrs[NLBL_MGMT_A_IPV4MASK] &&
397 	     info->attrs[NLBL_MGMT_A_IPV6MASK]) ||
398 	    ((info->attrs[NLBL_MGMT_A_IPV4ADDR] != NULL) ^
399 	     (info->attrs[NLBL_MGMT_A_IPV4MASK] != NULL)) ||
400 	    ((info->attrs[NLBL_MGMT_A_IPV6ADDR] != NULL) ^
401 	     (info->attrs[NLBL_MGMT_A_IPV6MASK] != NULL)))
402 		return -EINVAL;
403 
404 	netlbl_netlink_auditinfo(skb, &audit_info);
405 
406 	return netlbl_mgmt_add_common(info, &audit_info);
407 }
408 
409 /**
410  * netlbl_mgmt_remove - Handle a REMOVE message
411  * @skb: the NETLINK buffer
412  * @info: the Generic NETLINK info block
413  *
414  * Description:
415  * Process a user generated REMOVE message and remove the specified domain
416  * mappings.  Returns zero on success, negative values on failure.
417  *
418  */
419 static int netlbl_mgmt_remove(struct sk_buff *skb, struct genl_info *info)
420 {
421 	char *domain;
422 	struct netlbl_audit audit_info;
423 
424 	if (!info->attrs[NLBL_MGMT_A_DOMAIN])
425 		return -EINVAL;
426 
427 	netlbl_netlink_auditinfo(skb, &audit_info);
428 
429 	domain = nla_data(info->attrs[NLBL_MGMT_A_DOMAIN]);
430 	return netlbl_domhsh_remove(domain, &audit_info);
431 }
432 
433 /**
434  * netlbl_mgmt_listall_cb - netlbl_domhsh_walk() callback for LISTALL
435  * @entry: the domain mapping hash table entry
436  * @arg: the netlbl_domhsh_walk_arg structure
437  *
438  * Description:
439  * This function is designed to be used as a callback to the
440  * netlbl_domhsh_walk() function for use in generating a response for a LISTALL
441  * message.  Returns the size of the message on success, negative values on
442  * failure.
443  *
444  */
445 static int netlbl_mgmt_listall_cb(struct netlbl_dom_map *entry, void *arg)
446 {
447 	int ret_val = -ENOMEM;
448 	struct netlbl_domhsh_walk_arg *cb_arg = arg;
449 	void *data;
450 
451 	data = genlmsg_put(cb_arg->skb, NETLINK_CB(cb_arg->nl_cb->skb).pid,
452 			   cb_arg->seq, &netlbl_mgmt_gnl_family,
453 			   NLM_F_MULTI, NLBL_MGMT_C_LISTALL);
454 	if (data == NULL)
455 		goto listall_cb_failure;
456 
457 	ret_val = netlbl_mgmt_listentry(cb_arg->skb, entry);
458 	if (ret_val != 0)
459 		goto listall_cb_failure;
460 
461 	cb_arg->seq++;
462 	return genlmsg_end(cb_arg->skb, data);
463 
464 listall_cb_failure:
465 	genlmsg_cancel(cb_arg->skb, data);
466 	return ret_val;
467 }
468 
469 /**
470  * netlbl_mgmt_listall - Handle a LISTALL message
471  * @skb: the NETLINK buffer
472  * @cb: the NETLINK callback
473  *
474  * Description:
475  * Process a user generated LISTALL message and dumps the domain hash table in
476  * a form suitable for use in a kernel generated LISTALL message.  Returns zero
477  * on success, negative values on failure.
478  *
479  */
480 static int netlbl_mgmt_listall(struct sk_buff *skb,
481 			       struct netlink_callback *cb)
482 {
483 	struct netlbl_domhsh_walk_arg cb_arg;
484 	u32 skip_bkt = cb->args[0];
485 	u32 skip_chain = cb->args[1];
486 
487 	cb_arg.nl_cb = cb;
488 	cb_arg.skb = skb;
489 	cb_arg.seq = cb->nlh->nlmsg_seq;
490 
491 	netlbl_domhsh_walk(&skip_bkt,
492 			   &skip_chain,
493 			   netlbl_mgmt_listall_cb,
494 			   &cb_arg);
495 
496 	cb->args[0] = skip_bkt;
497 	cb->args[1] = skip_chain;
498 	return skb->len;
499 }
500 
501 /**
502  * netlbl_mgmt_adddef - Handle an ADDDEF message
503  * @skb: the NETLINK buffer
504  * @info: the Generic NETLINK info block
505  *
506  * Description:
507  * Process a user generated ADDDEF message and respond accordingly.  Returns
508  * zero on success, negative values on failure.
509  *
510  */
511 static int netlbl_mgmt_adddef(struct sk_buff *skb, struct genl_info *info)
512 {
513 	struct netlbl_audit audit_info;
514 
515 	if ((!info->attrs[NLBL_MGMT_A_PROTOCOL]) ||
516 	    (info->attrs[NLBL_MGMT_A_IPV4ADDR] &&
517 	     info->attrs[NLBL_MGMT_A_IPV6ADDR]) ||
518 	    (info->attrs[NLBL_MGMT_A_IPV4MASK] &&
519 	     info->attrs[NLBL_MGMT_A_IPV6MASK]) ||
520 	    ((info->attrs[NLBL_MGMT_A_IPV4ADDR] != NULL) ^
521 	     (info->attrs[NLBL_MGMT_A_IPV4MASK] != NULL)) ||
522 	    ((info->attrs[NLBL_MGMT_A_IPV6ADDR] != NULL) ^
523 	     (info->attrs[NLBL_MGMT_A_IPV6MASK] != NULL)))
524 		return -EINVAL;
525 
526 	netlbl_netlink_auditinfo(skb, &audit_info);
527 
528 	return netlbl_mgmt_add_common(info, &audit_info);
529 }
530 
531 /**
532  * netlbl_mgmt_removedef - Handle a REMOVEDEF message
533  * @skb: the NETLINK buffer
534  * @info: the Generic NETLINK info block
535  *
536  * Description:
537  * Process a user generated REMOVEDEF message and remove the default domain
538  * mapping.  Returns zero on success, negative values on failure.
539  *
540  */
541 static int netlbl_mgmt_removedef(struct sk_buff *skb, struct genl_info *info)
542 {
543 	struct netlbl_audit audit_info;
544 
545 	netlbl_netlink_auditinfo(skb, &audit_info);
546 
547 	return netlbl_domhsh_remove_default(&audit_info);
548 }
549 
550 /**
551  * netlbl_mgmt_listdef - Handle a LISTDEF message
552  * @skb: the NETLINK buffer
553  * @info: the Generic NETLINK info block
554  *
555  * Description:
556  * Process a user generated LISTDEF message and dumps the default domain
557  * mapping in a form suitable for use in a kernel generated LISTDEF message.
558  * Returns zero on success, negative values on failure.
559  *
560  */
561 static int netlbl_mgmt_listdef(struct sk_buff *skb, struct genl_info *info)
562 {
563 	int ret_val = -ENOMEM;
564 	struct sk_buff *ans_skb = NULL;
565 	void *data;
566 	struct netlbl_dom_map *entry;
567 
568 	ans_skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
569 	if (ans_skb == NULL)
570 		return -ENOMEM;
571 	data = genlmsg_put_reply(ans_skb, info, &netlbl_mgmt_gnl_family,
572 				 0, NLBL_MGMT_C_LISTDEF);
573 	if (data == NULL)
574 		goto listdef_failure;
575 
576 	rcu_read_lock();
577 	entry = netlbl_domhsh_getentry(NULL);
578 	if (entry == NULL) {
579 		ret_val = -ENOENT;
580 		goto listdef_failure_lock;
581 	}
582 	ret_val = netlbl_mgmt_listentry(ans_skb, entry);
583 	rcu_read_unlock();
584 	if (ret_val != 0)
585 		goto listdef_failure;
586 
587 	genlmsg_end(ans_skb, data);
588 	return genlmsg_reply(ans_skb, info);
589 
590 listdef_failure_lock:
591 	rcu_read_unlock();
592 listdef_failure:
593 	kfree_skb(ans_skb);
594 	return ret_val;
595 }
596 
597 /**
598  * netlbl_mgmt_protocols_cb - Write an individual PROTOCOL message response
599  * @skb: the skb to write to
600  * @cb: the NETLINK callback
601  * @protocol: the NetLabel protocol to use in the message
602  *
603  * Description:
604  * This function is to be used in conjunction with netlbl_mgmt_protocols() to
605  * answer a application's PROTOCOLS message.  Returns the size of the message
606  * on success, negative values on failure.
607  *
608  */
609 static int netlbl_mgmt_protocols_cb(struct sk_buff *skb,
610 				    struct netlink_callback *cb,
611 				    u32 protocol)
612 {
613 	int ret_val = -ENOMEM;
614 	void *data;
615 
616 	data = genlmsg_put(skb, NETLINK_CB(cb->skb).pid, cb->nlh->nlmsg_seq,
617 			   &netlbl_mgmt_gnl_family, NLM_F_MULTI,
618 			   NLBL_MGMT_C_PROTOCOLS);
619 	if (data == NULL)
620 		goto protocols_cb_failure;
621 
622 	ret_val = nla_put_u32(skb, NLBL_MGMT_A_PROTOCOL, protocol);
623 	if (ret_val != 0)
624 		goto protocols_cb_failure;
625 
626 	return genlmsg_end(skb, data);
627 
628 protocols_cb_failure:
629 	genlmsg_cancel(skb, data);
630 	return ret_val;
631 }
632 
633 /**
634  * netlbl_mgmt_protocols - Handle a PROTOCOLS message
635  * @skb: the NETLINK buffer
636  * @cb: the NETLINK callback
637  *
638  * Description:
639  * Process a user generated PROTOCOLS message and respond accordingly.
640  *
641  */
642 static int netlbl_mgmt_protocols(struct sk_buff *skb,
643 				 struct netlink_callback *cb)
644 {
645 	u32 protos_sent = cb->args[0];
646 
647 	if (protos_sent == 0) {
648 		if (netlbl_mgmt_protocols_cb(skb,
649 					     cb,
650 					     NETLBL_NLTYPE_UNLABELED) < 0)
651 			goto protocols_return;
652 		protos_sent++;
653 	}
654 	if (protos_sent == 1) {
655 		if (netlbl_mgmt_protocols_cb(skb,
656 					     cb,
657 					     NETLBL_NLTYPE_CIPSOV4) < 0)
658 			goto protocols_return;
659 		protos_sent++;
660 	}
661 
662 protocols_return:
663 	cb->args[0] = protos_sent;
664 	return skb->len;
665 }
666 
667 /**
668  * netlbl_mgmt_version - Handle a VERSION message
669  * @skb: the NETLINK buffer
670  * @info: the Generic NETLINK info block
671  *
672  * Description:
673  * Process a user generated VERSION message and respond accordingly.  Returns
674  * zero on success, negative values on failure.
675  *
676  */
677 static int netlbl_mgmt_version(struct sk_buff *skb, struct genl_info *info)
678 {
679 	int ret_val = -ENOMEM;
680 	struct sk_buff *ans_skb = NULL;
681 	void *data;
682 
683 	ans_skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
684 	if (ans_skb == NULL)
685 		return -ENOMEM;
686 	data = genlmsg_put_reply(ans_skb, info, &netlbl_mgmt_gnl_family,
687 				 0, NLBL_MGMT_C_VERSION);
688 	if (data == NULL)
689 		goto version_failure;
690 
691 	ret_val = nla_put_u32(ans_skb,
692 			      NLBL_MGMT_A_VERSION,
693 			      NETLBL_PROTO_VERSION);
694 	if (ret_val != 0)
695 		goto version_failure;
696 
697 	genlmsg_end(ans_skb, data);
698 	return genlmsg_reply(ans_skb, info);
699 
700 version_failure:
701 	kfree_skb(ans_skb);
702 	return ret_val;
703 }
704 
705 
706 /*
707  * NetLabel Generic NETLINK Command Definitions
708  */
709 
710 static struct genl_ops netlbl_mgmt_genl_ops[] = {
711 	{
712 	.cmd = NLBL_MGMT_C_ADD,
713 	.flags = GENL_ADMIN_PERM,
714 	.policy = netlbl_mgmt_genl_policy,
715 	.doit = netlbl_mgmt_add,
716 	.dumpit = NULL,
717 	},
718 	{
719 	.cmd = NLBL_MGMT_C_REMOVE,
720 	.flags = GENL_ADMIN_PERM,
721 	.policy = netlbl_mgmt_genl_policy,
722 	.doit = netlbl_mgmt_remove,
723 	.dumpit = NULL,
724 	},
725 	{
726 	.cmd = NLBL_MGMT_C_LISTALL,
727 	.flags = 0,
728 	.policy = netlbl_mgmt_genl_policy,
729 	.doit = NULL,
730 	.dumpit = netlbl_mgmt_listall,
731 	},
732 	{
733 	.cmd = NLBL_MGMT_C_ADDDEF,
734 	.flags = GENL_ADMIN_PERM,
735 	.policy = netlbl_mgmt_genl_policy,
736 	.doit = netlbl_mgmt_adddef,
737 	.dumpit = NULL,
738 	},
739 	{
740 	.cmd = NLBL_MGMT_C_REMOVEDEF,
741 	.flags = GENL_ADMIN_PERM,
742 	.policy = netlbl_mgmt_genl_policy,
743 	.doit = netlbl_mgmt_removedef,
744 	.dumpit = NULL,
745 	},
746 	{
747 	.cmd = NLBL_MGMT_C_LISTDEF,
748 	.flags = 0,
749 	.policy = netlbl_mgmt_genl_policy,
750 	.doit = netlbl_mgmt_listdef,
751 	.dumpit = NULL,
752 	},
753 	{
754 	.cmd = NLBL_MGMT_C_PROTOCOLS,
755 	.flags = 0,
756 	.policy = netlbl_mgmt_genl_policy,
757 	.doit = NULL,
758 	.dumpit = netlbl_mgmt_protocols,
759 	},
760 	{
761 	.cmd = NLBL_MGMT_C_VERSION,
762 	.flags = 0,
763 	.policy = netlbl_mgmt_genl_policy,
764 	.doit = netlbl_mgmt_version,
765 	.dumpit = NULL,
766 	},
767 };
768 
769 /*
770  * NetLabel Generic NETLINK Protocol Functions
771  */
772 
773 /**
774  * netlbl_mgmt_genl_init - Register the NetLabel management component
775  *
776  * Description:
777  * Register the NetLabel management component with the Generic NETLINK
778  * mechanism.  Returns zero on success, negative values on failure.
779  *
780  */
781 int __init netlbl_mgmt_genl_init(void)
782 {
783 	return genl_register_family_with_ops(&netlbl_mgmt_gnl_family,
784 		netlbl_mgmt_genl_ops, ARRAY_SIZE(netlbl_mgmt_genl_ops));
785 }
786