xref: /linux/net/netlabel/netlabel_unlabeled.c (revision 367b8112fe2ea5c39a7bb4d263dcdd9b612fae18)
1 /*
2  * NetLabel Unlabeled Support
3  *
4  * This file defines functions for dealing with unlabeled packets for the
5  * NetLabel system.  The NetLabel system manages static and dynamic label
6  * mappings for network 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/rcupdate.h>
33 #include <linux/list.h>
34 #include <linux/spinlock.h>
35 #include <linux/socket.h>
36 #include <linux/string.h>
37 #include <linux/skbuff.h>
38 #include <linux/audit.h>
39 #include <linux/in.h>
40 #include <linux/in6.h>
41 #include <linux/ip.h>
42 #include <linux/ipv6.h>
43 #include <linux/notifier.h>
44 #include <linux/netdevice.h>
45 #include <linux/security.h>
46 #include <net/sock.h>
47 #include <net/netlink.h>
48 #include <net/genetlink.h>
49 #include <net/ip.h>
50 #include <net/ipv6.h>
51 #include <net/net_namespace.h>
52 #include <net/netlabel.h>
53 #include <asm/bug.h>
54 #include <asm/atomic.h>
55 
56 #include "netlabel_user.h"
57 #include "netlabel_addrlist.h"
58 #include "netlabel_domainhash.h"
59 #include "netlabel_unlabeled.h"
60 #include "netlabel_mgmt.h"
61 
62 /* NOTE: at present we always use init's network namespace since we don't
63  *       presently support different namespaces even though the majority of
64  *       the functions in this file are "namespace safe" */
65 
66 /* The unlabeled connection hash table which we use to map network interfaces
67  * and addresses of unlabeled packets to a user specified secid value for the
68  * LSM.  The hash table is used to lookup the network interface entry
69  * (struct netlbl_unlhsh_iface) and then the interface entry is used to
70  * lookup an IP address match from an ordered list.  If a network interface
71  * match can not be found in the hash table then the default entry
72  * (netlbl_unlhsh_def) is used.  The IP address entry list
73  * (struct netlbl_unlhsh_addr) is ordered such that the entries with a
74  * larger netmask come first.
75  */
76 struct netlbl_unlhsh_tbl {
77 	struct list_head *tbl;
78 	u32 size;
79 };
80 #define netlbl_unlhsh_addr4_entry(iter) \
81 	container_of(iter, struct netlbl_unlhsh_addr4, list)
82 struct netlbl_unlhsh_addr4 {
83 	u32 secid;
84 
85 	struct netlbl_af4list list;
86 	struct rcu_head rcu;
87 };
88 #define netlbl_unlhsh_addr6_entry(iter) \
89 	container_of(iter, struct netlbl_unlhsh_addr6, list)
90 struct netlbl_unlhsh_addr6 {
91 	u32 secid;
92 
93 	struct netlbl_af6list list;
94 	struct rcu_head rcu;
95 };
96 struct netlbl_unlhsh_iface {
97 	int ifindex;
98 	struct list_head addr4_list;
99 	struct list_head addr6_list;
100 
101 	u32 valid;
102 	struct list_head list;
103 	struct rcu_head rcu;
104 };
105 
106 /* Argument struct for netlbl_unlhsh_walk() */
107 struct netlbl_unlhsh_walk_arg {
108 	struct netlink_callback *nl_cb;
109 	struct sk_buff *skb;
110 	u32 seq;
111 };
112 
113 /* Unlabeled connection hash table */
114 /* updates should be so rare that having one spinlock for the entire
115  * hash table should be okay */
116 static DEFINE_SPINLOCK(netlbl_unlhsh_lock);
117 static struct netlbl_unlhsh_tbl *netlbl_unlhsh = NULL;
118 static struct netlbl_unlhsh_iface *netlbl_unlhsh_def = NULL;
119 
120 /* Accept unlabeled packets flag */
121 static u8 netlabel_unlabel_acceptflg = 0;
122 
123 /* NetLabel Generic NETLINK unlabeled family */
124 static struct genl_family netlbl_unlabel_gnl_family = {
125 	.id = GENL_ID_GENERATE,
126 	.hdrsize = 0,
127 	.name = NETLBL_NLTYPE_UNLABELED_NAME,
128 	.version = NETLBL_PROTO_VERSION,
129 	.maxattr = NLBL_UNLABEL_A_MAX,
130 };
131 
132 /* NetLabel Netlink attribute policy */
133 static const struct nla_policy netlbl_unlabel_genl_policy[NLBL_UNLABEL_A_MAX + 1] = {
134 	[NLBL_UNLABEL_A_ACPTFLG] = { .type = NLA_U8 },
135 	[NLBL_UNLABEL_A_IPV6ADDR] = { .type = NLA_BINARY,
136 				      .len = sizeof(struct in6_addr) },
137 	[NLBL_UNLABEL_A_IPV6MASK] = { .type = NLA_BINARY,
138 				      .len = sizeof(struct in6_addr) },
139 	[NLBL_UNLABEL_A_IPV4ADDR] = { .type = NLA_BINARY,
140 				      .len = sizeof(struct in_addr) },
141 	[NLBL_UNLABEL_A_IPV4MASK] = { .type = NLA_BINARY,
142 				      .len = sizeof(struct in_addr) },
143 	[NLBL_UNLABEL_A_IFACE] = { .type = NLA_NUL_STRING,
144 				   .len = IFNAMSIZ - 1 },
145 	[NLBL_UNLABEL_A_SECCTX] = { .type = NLA_BINARY }
146 };
147 
148 /*
149  * Unlabeled Connection Hash Table Functions
150  */
151 
152 /**
153  * netlbl_unlhsh_free_addr4 - Frees an IPv4 address entry from the hash table
154  * @entry: the entry's RCU field
155  *
156  * Description:
157  * This function is designed to be used as a callback to the call_rcu()
158  * function so that memory allocated to a hash table address entry can be
159  * released safely.
160  *
161  */
162 static void netlbl_unlhsh_free_addr4(struct rcu_head *entry)
163 {
164 	struct netlbl_unlhsh_addr4 *ptr;
165 
166 	ptr = container_of(entry, struct netlbl_unlhsh_addr4, rcu);
167 	kfree(ptr);
168 }
169 
170 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
171 /**
172  * netlbl_unlhsh_free_addr6 - Frees an IPv6 address entry from the hash table
173  * @entry: the entry's RCU field
174  *
175  * Description:
176  * This function is designed to be used as a callback to the call_rcu()
177  * function so that memory allocated to a hash table address entry can be
178  * released safely.
179  *
180  */
181 static void netlbl_unlhsh_free_addr6(struct rcu_head *entry)
182 {
183 	struct netlbl_unlhsh_addr6 *ptr;
184 
185 	ptr = container_of(entry, struct netlbl_unlhsh_addr6, rcu);
186 	kfree(ptr);
187 }
188 #endif /* IPv6 */
189 
190 /**
191  * netlbl_unlhsh_free_iface - Frees an interface entry from the hash table
192  * @entry: the entry's RCU field
193  *
194  * Description:
195  * This function is designed to be used as a callback to the call_rcu()
196  * function so that memory allocated to a hash table interface entry can be
197  * released safely.  It is important to note that this function does not free
198  * the IPv4 and IPv6 address lists contained as part of an interface entry.  It
199  * is up to the rest of the code to make sure an interface entry is only freed
200  * once it's address lists are empty.
201  *
202  */
203 static void netlbl_unlhsh_free_iface(struct rcu_head *entry)
204 {
205 	struct netlbl_unlhsh_iface *iface;
206 	struct netlbl_af4list *iter4;
207 	struct netlbl_af4list *tmp4;
208 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
209 	struct netlbl_af6list *iter6;
210 	struct netlbl_af6list *tmp6;
211 #endif /* IPv6 */
212 
213 	iface = container_of(entry, struct netlbl_unlhsh_iface, rcu);
214 
215 	/* no need for locks here since we are the only one with access to this
216 	 * structure */
217 
218 	netlbl_af4list_foreach_safe(iter4, tmp4, &iface->addr4_list) {
219 		netlbl_af4list_remove_entry(iter4);
220 		kfree(netlbl_unlhsh_addr4_entry(iter4));
221 	}
222 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
223 	netlbl_af6list_foreach_safe(iter6, tmp6, &iface->addr6_list) {
224 		netlbl_af6list_remove_entry(iter6);
225 		kfree(netlbl_unlhsh_addr6_entry(iter6));
226 	}
227 #endif /* IPv6 */
228 	kfree(iface);
229 }
230 
231 /**
232  * netlbl_unlhsh_hash - Hashing function for the hash table
233  * @ifindex: the network interface/device to hash
234  *
235  * Description:
236  * This is the hashing function for the unlabeled hash table, it returns the
237  * bucket number for the given device/interface.  The caller is responsible for
238  * calling the rcu_read_[un]lock() functions.
239  *
240  */
241 static u32 netlbl_unlhsh_hash(int ifindex)
242 {
243 	/* this is taken _almost_ directly from
244 	 * security/selinux/netif.c:sel_netif_hasfn() as they do pretty much
245 	 * the same thing */
246 	return ifindex & (rcu_dereference(netlbl_unlhsh)->size - 1);
247 }
248 
249 /**
250  * netlbl_unlhsh_search_iface - Search for a matching interface entry
251  * @ifindex: the network interface
252  *
253  * Description:
254  * Searches the unlabeled connection hash table and returns a pointer to the
255  * interface entry which matches @ifindex, otherwise NULL is returned.  The
256  * caller is responsible for calling the rcu_read_[un]lock() functions.
257  *
258  */
259 static struct netlbl_unlhsh_iface *netlbl_unlhsh_search_iface(int ifindex)
260 {
261 	u32 bkt;
262 	struct list_head *bkt_list;
263 	struct netlbl_unlhsh_iface *iter;
264 
265 	bkt = netlbl_unlhsh_hash(ifindex);
266 	bkt_list = &rcu_dereference(netlbl_unlhsh)->tbl[bkt];
267 	list_for_each_entry_rcu(iter, bkt_list, list)
268 		if (iter->valid && iter->ifindex == ifindex)
269 			return iter;
270 
271 	return NULL;
272 }
273 
274 /**
275  * netlbl_unlhsh_search_iface_def - Search for a matching interface entry
276  * @ifindex: the network interface
277  *
278  * Description:
279  * Searches the unlabeled connection hash table and returns a pointer to the
280  * interface entry which matches @ifindex.  If an exact match can not be found
281  * and there is a valid default entry, the default entry is returned, otherwise
282  * NULL is returned.  The caller is responsible for calling the
283  * rcu_read_[un]lock() functions.
284  *
285  */
286 static struct netlbl_unlhsh_iface *netlbl_unlhsh_search_iface_def(int ifindex)
287 {
288 	struct netlbl_unlhsh_iface *entry;
289 
290 	entry = netlbl_unlhsh_search_iface(ifindex);
291 	if (entry != NULL)
292 		return entry;
293 
294 	entry = rcu_dereference(netlbl_unlhsh_def);
295 	if (entry != NULL && entry->valid)
296 		return entry;
297 
298 	return NULL;
299 }
300 
301 /**
302  * netlbl_unlhsh_add_addr4 - Add a new IPv4 address entry to the hash table
303  * @iface: the associated interface entry
304  * @addr: IPv4 address in network byte order
305  * @mask: IPv4 address mask in network byte order
306  * @secid: LSM secid value for entry
307  *
308  * Description:
309  * Add a new address entry into the unlabeled connection hash table using the
310  * interface entry specified by @iface.  On success zero is returned, otherwise
311  * a negative value is returned.  The caller is responsible for calling the
312  * rcu_read_[un]lock() functions.
313  *
314  */
315 static int netlbl_unlhsh_add_addr4(struct netlbl_unlhsh_iface *iface,
316 				   const struct in_addr *addr,
317 				   const struct in_addr *mask,
318 				   u32 secid)
319 {
320 	int ret_val;
321 	struct netlbl_unlhsh_addr4 *entry;
322 
323 	entry = kzalloc(sizeof(*entry), GFP_ATOMIC);
324 	if (entry == NULL)
325 		return -ENOMEM;
326 
327 	entry->list.addr = addr->s_addr & mask->s_addr;
328 	entry->list.mask = mask->s_addr;
329 	entry->list.valid = 1;
330 	INIT_RCU_HEAD(&entry->rcu);
331 	entry->secid = secid;
332 
333 	spin_lock(&netlbl_unlhsh_lock);
334 	ret_val = netlbl_af4list_add(&entry->list, &iface->addr4_list);
335 	spin_unlock(&netlbl_unlhsh_lock);
336 
337 	if (ret_val != 0)
338 		kfree(entry);
339 	return ret_val;
340 }
341 
342 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
343 /**
344  * netlbl_unlhsh_add_addr6 - Add a new IPv6 address entry to the hash table
345  * @iface: the associated interface entry
346  * @addr: IPv6 address in network byte order
347  * @mask: IPv6 address mask in network byte order
348  * @secid: LSM secid value for entry
349  *
350  * Description:
351  * Add a new address entry into the unlabeled connection hash table using the
352  * interface entry specified by @iface.  On success zero is returned, otherwise
353  * a negative value is returned.  The caller is responsible for calling the
354  * rcu_read_[un]lock() functions.
355  *
356  */
357 static int netlbl_unlhsh_add_addr6(struct netlbl_unlhsh_iface *iface,
358 				   const struct in6_addr *addr,
359 				   const struct in6_addr *mask,
360 				   u32 secid)
361 {
362 	int ret_val;
363 	struct netlbl_unlhsh_addr6 *entry;
364 
365 	entry = kzalloc(sizeof(*entry), GFP_ATOMIC);
366 	if (entry == NULL)
367 		return -ENOMEM;
368 
369 	ipv6_addr_copy(&entry->list.addr, addr);
370 	entry->list.addr.s6_addr32[0] &= mask->s6_addr32[0];
371 	entry->list.addr.s6_addr32[1] &= mask->s6_addr32[1];
372 	entry->list.addr.s6_addr32[2] &= mask->s6_addr32[2];
373 	entry->list.addr.s6_addr32[3] &= mask->s6_addr32[3];
374 	ipv6_addr_copy(&entry->list.mask, mask);
375 	entry->list.valid = 1;
376 	INIT_RCU_HEAD(&entry->rcu);
377 	entry->secid = secid;
378 
379 	spin_lock(&netlbl_unlhsh_lock);
380 	ret_val = netlbl_af6list_add(&entry->list, &iface->addr6_list);
381 	spin_unlock(&netlbl_unlhsh_lock);
382 
383 	if (ret_val != 0)
384 		kfree(entry);
385 	return 0;
386 }
387 #endif /* IPv6 */
388 
389 /**
390  * netlbl_unlhsh_add_iface - Adds a new interface entry to the hash table
391  * @ifindex: network interface
392  *
393  * Description:
394  * Add a new, empty, interface entry into the unlabeled connection hash table.
395  * On success a pointer to the new interface entry is returned, on failure NULL
396  * is returned.  The caller is responsible for calling the rcu_read_[un]lock()
397  * functions.
398  *
399  */
400 static struct netlbl_unlhsh_iface *netlbl_unlhsh_add_iface(int ifindex)
401 {
402 	u32 bkt;
403 	struct netlbl_unlhsh_iface *iface;
404 
405 	iface = kzalloc(sizeof(*iface), GFP_ATOMIC);
406 	if (iface == NULL)
407 		return NULL;
408 
409 	iface->ifindex = ifindex;
410 	INIT_LIST_HEAD(&iface->addr4_list);
411 	INIT_LIST_HEAD(&iface->addr6_list);
412 	iface->valid = 1;
413 	INIT_RCU_HEAD(&iface->rcu);
414 
415 	spin_lock(&netlbl_unlhsh_lock);
416 	if (ifindex > 0) {
417 		bkt = netlbl_unlhsh_hash(ifindex);
418 		if (netlbl_unlhsh_search_iface(ifindex) != NULL)
419 			goto add_iface_failure;
420 		list_add_tail_rcu(&iface->list,
421 				  &rcu_dereference(netlbl_unlhsh)->tbl[bkt]);
422 	} else {
423 		INIT_LIST_HEAD(&iface->list);
424 		if (rcu_dereference(netlbl_unlhsh_def) != NULL)
425 			goto add_iface_failure;
426 		rcu_assign_pointer(netlbl_unlhsh_def, iface);
427 	}
428 	spin_unlock(&netlbl_unlhsh_lock);
429 
430 	return iface;
431 
432 add_iface_failure:
433 	spin_unlock(&netlbl_unlhsh_lock);
434 	kfree(iface);
435 	return NULL;
436 }
437 
438 /**
439  * netlbl_unlhsh_add - Adds a new entry to the unlabeled connection hash table
440  * @net: network namespace
441  * @dev_name: interface name
442  * @addr: IP address in network byte order
443  * @mask: address mask in network byte order
444  * @addr_len: length of address/mask (4 for IPv4, 16 for IPv6)
445  * @secid: LSM secid value for the entry
446  * @audit_info: NetLabel audit information
447  *
448  * Description:
449  * Adds a new entry to the unlabeled connection hash table.  Returns zero on
450  * success, negative values on failure.
451  *
452  */
453 static int netlbl_unlhsh_add(struct net *net,
454 			     const char *dev_name,
455 			     const void *addr,
456 			     const void *mask,
457 			     u32 addr_len,
458 			     u32 secid,
459 			     struct netlbl_audit *audit_info)
460 {
461 	int ret_val;
462 	int ifindex;
463 	struct net_device *dev;
464 	struct netlbl_unlhsh_iface *iface;
465 	struct audit_buffer *audit_buf = NULL;
466 	char *secctx = NULL;
467 	u32 secctx_len;
468 
469 	if (addr_len != sizeof(struct in_addr) &&
470 	    addr_len != sizeof(struct in6_addr))
471 		return -EINVAL;
472 
473 	rcu_read_lock();
474 	if (dev_name != NULL) {
475 		dev = dev_get_by_name(net, dev_name);
476 		if (dev == NULL) {
477 			ret_val = -ENODEV;
478 			goto unlhsh_add_return;
479 		}
480 		ifindex = dev->ifindex;
481 		dev_put(dev);
482 		iface = netlbl_unlhsh_search_iface(ifindex);
483 	} else {
484 		ifindex = 0;
485 		iface = rcu_dereference(netlbl_unlhsh_def);
486 	}
487 	if (iface == NULL) {
488 		iface = netlbl_unlhsh_add_iface(ifindex);
489 		if (iface == NULL) {
490 			ret_val = -ENOMEM;
491 			goto unlhsh_add_return;
492 		}
493 	}
494 	audit_buf = netlbl_audit_start_common(AUDIT_MAC_UNLBL_STCADD,
495 					      audit_info);
496 	switch (addr_len) {
497 	case sizeof(struct in_addr): {
498 		struct in_addr *addr4, *mask4;
499 
500 		addr4 = (struct in_addr *)addr;
501 		mask4 = (struct in_addr *)mask;
502 		ret_val = netlbl_unlhsh_add_addr4(iface, addr4, mask4, secid);
503 		if (audit_buf != NULL)
504 			netlbl_af4list_audit_addr(audit_buf, 1,
505 						  dev_name,
506 						  addr4->s_addr,
507 						  mask4->s_addr);
508 		break;
509 	}
510 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
511 	case sizeof(struct in6_addr): {
512 		struct in6_addr *addr6, *mask6;
513 
514 		addr6 = (struct in6_addr *)addr;
515 		mask6 = (struct in6_addr *)mask;
516 		ret_val = netlbl_unlhsh_add_addr6(iface, addr6, mask6, secid);
517 		if (audit_buf != NULL)
518 			netlbl_af6list_audit_addr(audit_buf, 1,
519 						  dev_name,
520 						  addr6, mask6);
521 		break;
522 	}
523 #endif /* IPv6 */
524 	default:
525 		ret_val = -EINVAL;
526 	}
527 	if (ret_val == 0)
528 		atomic_inc(&netlabel_mgmt_protocount);
529 
530 unlhsh_add_return:
531 	rcu_read_unlock();
532 	if (audit_buf != NULL) {
533 		if (security_secid_to_secctx(secid,
534 					     &secctx,
535 					     &secctx_len) == 0) {
536 			audit_log_format(audit_buf, " sec_obj=%s", secctx);
537 			security_release_secctx(secctx, secctx_len);
538 		}
539 		audit_log_format(audit_buf, " res=%u", ret_val == 0 ? 1 : 0);
540 		audit_log_end(audit_buf);
541 	}
542 	return ret_val;
543 }
544 
545 /**
546  * netlbl_unlhsh_remove_addr4 - Remove an IPv4 address entry
547  * @net: network namespace
548  * @iface: interface entry
549  * @addr: IP address
550  * @mask: IP address mask
551  * @audit_info: NetLabel audit information
552  *
553  * Description:
554  * Remove an IP address entry from the unlabeled connection hash table.
555  * Returns zero on success, negative values on failure.  The caller is
556  * responsible for calling the rcu_read_[un]lock() functions.
557  *
558  */
559 static int netlbl_unlhsh_remove_addr4(struct net *net,
560 				      struct netlbl_unlhsh_iface *iface,
561 				      const struct in_addr *addr,
562 				      const struct in_addr *mask,
563 				      struct netlbl_audit *audit_info)
564 {
565 	int ret_val = 0;
566 	struct netlbl_af4list *list_entry;
567 	struct netlbl_unlhsh_addr4 *entry;
568 	struct audit_buffer *audit_buf;
569 	struct net_device *dev;
570 	char *secctx;
571 	u32 secctx_len;
572 
573 	spin_lock(&netlbl_unlhsh_lock);
574 	list_entry = netlbl_af4list_remove(addr->s_addr, mask->s_addr,
575 					   &iface->addr4_list);
576 	spin_unlock(&netlbl_unlhsh_lock);
577 	if (list_entry == NULL)
578 		ret_val = -ENOENT;
579 	entry = netlbl_unlhsh_addr4_entry(list_entry);
580 
581 	audit_buf = netlbl_audit_start_common(AUDIT_MAC_UNLBL_STCDEL,
582 					      audit_info);
583 	if (audit_buf != NULL) {
584 		dev = dev_get_by_index(net, iface->ifindex);
585 		netlbl_af4list_audit_addr(audit_buf, 1,
586 					  (dev != NULL ? dev->name : NULL),
587 					  addr->s_addr, mask->s_addr);
588 		if (dev != NULL)
589 			dev_put(dev);
590 		if (entry && security_secid_to_secctx(entry->secid,
591 						      &secctx,
592 						      &secctx_len) == 0) {
593 			audit_log_format(audit_buf, " sec_obj=%s", secctx);
594 			security_release_secctx(secctx, secctx_len);
595 		}
596 		audit_log_format(audit_buf, " res=%u", ret_val == 0 ? 1 : 0);
597 		audit_log_end(audit_buf);
598 	}
599 
600 	if (ret_val == 0)
601 		call_rcu(&entry->rcu, netlbl_unlhsh_free_addr4);
602 	return ret_val;
603 }
604 
605 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
606 /**
607  * netlbl_unlhsh_remove_addr6 - Remove an IPv6 address entry
608  * @net: network namespace
609  * @iface: interface entry
610  * @addr: IP address
611  * @mask: IP address mask
612  * @audit_info: NetLabel audit information
613  *
614  * Description:
615  * Remove an IP address entry from the unlabeled connection hash table.
616  * Returns zero on success, negative values on failure.  The caller is
617  * responsible for calling the rcu_read_[un]lock() functions.
618  *
619  */
620 static int netlbl_unlhsh_remove_addr6(struct net *net,
621 				      struct netlbl_unlhsh_iface *iface,
622 				      const struct in6_addr *addr,
623 				      const struct in6_addr *mask,
624 				      struct netlbl_audit *audit_info)
625 {
626 	int ret_val = 0;
627 	struct netlbl_af6list *list_entry;
628 	struct netlbl_unlhsh_addr6 *entry;
629 	struct audit_buffer *audit_buf;
630 	struct net_device *dev;
631 	char *secctx;
632 	u32 secctx_len;
633 
634 	spin_lock(&netlbl_unlhsh_lock);
635 	list_entry = netlbl_af6list_remove(addr, mask, &iface->addr6_list);
636 	spin_unlock(&netlbl_unlhsh_lock);
637 	if (list_entry == NULL)
638 		ret_val = -ENOENT;
639 	entry = netlbl_unlhsh_addr6_entry(list_entry);
640 
641 	audit_buf = netlbl_audit_start_common(AUDIT_MAC_UNLBL_STCDEL,
642 					      audit_info);
643 	if (audit_buf != NULL) {
644 		dev = dev_get_by_index(net, iface->ifindex);
645 		netlbl_af6list_audit_addr(audit_buf, 1,
646 					  (dev != NULL ? dev->name : NULL),
647 					  addr, mask);
648 		if (dev != NULL)
649 			dev_put(dev);
650 		if (entry && security_secid_to_secctx(entry->secid,
651 						      &secctx,
652 						      &secctx_len) == 0) {
653 			audit_log_format(audit_buf, " sec_obj=%s", secctx);
654 			security_release_secctx(secctx, secctx_len);
655 		}
656 		audit_log_format(audit_buf, " res=%u", ret_val == 0 ? 1 : 0);
657 		audit_log_end(audit_buf);
658 	}
659 
660 	if (ret_val == 0)
661 		call_rcu(&entry->rcu, netlbl_unlhsh_free_addr6);
662 	return ret_val;
663 }
664 #endif /* IPv6 */
665 
666 /**
667  * netlbl_unlhsh_condremove_iface - Remove an interface entry
668  * @iface: the interface entry
669  *
670  * Description:
671  * Remove an interface entry from the unlabeled connection hash table if it is
672  * empty.  An interface entry is considered to be empty if there are no
673  * address entries assigned to it.
674  *
675  */
676 static void netlbl_unlhsh_condremove_iface(struct netlbl_unlhsh_iface *iface)
677 {
678 	struct netlbl_af4list *iter4;
679 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
680 	struct netlbl_af6list *iter6;
681 #endif /* IPv6 */
682 
683 	spin_lock(&netlbl_unlhsh_lock);
684 	netlbl_af4list_foreach_rcu(iter4, &iface->addr4_list)
685 		goto unlhsh_condremove_failure;
686 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
687 	netlbl_af6list_foreach_rcu(iter6, &iface->addr6_list)
688 		goto unlhsh_condremove_failure;
689 #endif /* IPv6 */
690 	iface->valid = 0;
691 	if (iface->ifindex > 0)
692 		list_del_rcu(&iface->list);
693 	else
694 		rcu_assign_pointer(netlbl_unlhsh_def, NULL);
695 	spin_unlock(&netlbl_unlhsh_lock);
696 
697 	call_rcu(&iface->rcu, netlbl_unlhsh_free_iface);
698 	return;
699 
700 unlhsh_condremove_failure:
701 	spin_unlock(&netlbl_unlhsh_lock);
702 	return;
703 }
704 
705 /**
706  * netlbl_unlhsh_remove - Remove an entry from the unlabeled hash table
707  * @net: network namespace
708  * @dev_name: interface name
709  * @addr: IP address in network byte order
710  * @mask: address mask in network byte order
711  * @addr_len: length of address/mask (4 for IPv4, 16 for IPv6)
712  * @audit_info: NetLabel audit information
713  *
714  * Description:
715  * Removes and existing entry from the unlabeled connection hash table.
716  * Returns zero on success, negative values on failure.
717  *
718  */
719 static int netlbl_unlhsh_remove(struct net *net,
720 				const char *dev_name,
721 				const void *addr,
722 				const void *mask,
723 				u32 addr_len,
724 				struct netlbl_audit *audit_info)
725 {
726 	int ret_val;
727 	struct net_device *dev;
728 	struct netlbl_unlhsh_iface *iface;
729 
730 	if (addr_len != sizeof(struct in_addr) &&
731 	    addr_len != sizeof(struct in6_addr))
732 		return -EINVAL;
733 
734 	rcu_read_lock();
735 	if (dev_name != NULL) {
736 		dev = dev_get_by_name(net, dev_name);
737 		if (dev == NULL) {
738 			ret_val = -ENODEV;
739 			goto unlhsh_remove_return;
740 		}
741 		iface = netlbl_unlhsh_search_iface(dev->ifindex);
742 		dev_put(dev);
743 	} else
744 		iface = rcu_dereference(netlbl_unlhsh_def);
745 	if (iface == NULL) {
746 		ret_val = -ENOENT;
747 		goto unlhsh_remove_return;
748 	}
749 	switch (addr_len) {
750 	case sizeof(struct in_addr):
751 		ret_val = netlbl_unlhsh_remove_addr4(net,
752 						     iface, addr, mask,
753 						     audit_info);
754 		break;
755 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
756 	case sizeof(struct in6_addr):
757 		ret_val = netlbl_unlhsh_remove_addr6(net,
758 						     iface, addr, mask,
759 						     audit_info);
760 		break;
761 #endif /* IPv6 */
762 	default:
763 		ret_val = -EINVAL;
764 	}
765 	if (ret_val == 0) {
766 		netlbl_unlhsh_condremove_iface(iface);
767 		atomic_dec(&netlabel_mgmt_protocount);
768 	}
769 
770 unlhsh_remove_return:
771 	rcu_read_unlock();
772 	return ret_val;
773 }
774 
775 /*
776  * General Helper Functions
777  */
778 
779 /**
780  * netlbl_unlhsh_netdev_handler - Network device notification handler
781  * @this: notifier block
782  * @event: the event
783  * @ptr: the network device (cast to void)
784  *
785  * Description:
786  * Handle network device events, although at present all we care about is a
787  * network device going away.  In the case of a device going away we clear any
788  * related entries from the unlabeled connection hash table.
789  *
790  */
791 static int netlbl_unlhsh_netdev_handler(struct notifier_block *this,
792 					unsigned long event,
793 					void *ptr)
794 {
795 	struct net_device *dev = ptr;
796 	struct netlbl_unlhsh_iface *iface = NULL;
797 
798 	if (!net_eq(dev_net(dev), &init_net))
799 		return NOTIFY_DONE;
800 
801 	/* XXX - should this be a check for NETDEV_DOWN or _UNREGISTER? */
802 	if (event == NETDEV_DOWN) {
803 		spin_lock(&netlbl_unlhsh_lock);
804 		iface = netlbl_unlhsh_search_iface(dev->ifindex);
805 		if (iface != NULL && iface->valid) {
806 			iface->valid = 0;
807 			list_del_rcu(&iface->list);
808 		} else
809 			iface = NULL;
810 		spin_unlock(&netlbl_unlhsh_lock);
811 	}
812 
813 	if (iface != NULL)
814 		call_rcu(&iface->rcu, netlbl_unlhsh_free_iface);
815 
816 	return NOTIFY_DONE;
817 }
818 
819 /**
820  * netlbl_unlabel_acceptflg_set - Set the unlabeled accept flag
821  * @value: desired value
822  * @audit_info: NetLabel audit information
823  *
824  * Description:
825  * Set the value of the unlabeled accept flag to @value.
826  *
827  */
828 static void netlbl_unlabel_acceptflg_set(u8 value,
829 					 struct netlbl_audit *audit_info)
830 {
831 	struct audit_buffer *audit_buf;
832 	u8 old_val;
833 
834 	old_val = netlabel_unlabel_acceptflg;
835 	netlabel_unlabel_acceptflg = value;
836 	audit_buf = netlbl_audit_start_common(AUDIT_MAC_UNLBL_ALLOW,
837 					      audit_info);
838 	if (audit_buf != NULL) {
839 		audit_log_format(audit_buf,
840 				 " unlbl_accept=%u old=%u", value, old_val);
841 		audit_log_end(audit_buf);
842 	}
843 }
844 
845 /**
846  * netlbl_unlabel_addrinfo_get - Get the IPv4/6 address information
847  * @info: the Generic NETLINK info block
848  * @addr: the IP address
849  * @mask: the IP address mask
850  * @len: the address length
851  *
852  * Description:
853  * Examine the Generic NETLINK message and extract the IP address information.
854  * Returns zero on success, negative values on failure.
855  *
856  */
857 static int netlbl_unlabel_addrinfo_get(struct genl_info *info,
858 				       void **addr,
859 				       void **mask,
860 				       u32 *len)
861 {
862 	u32 addr_len;
863 
864 	if (info->attrs[NLBL_UNLABEL_A_IPV4ADDR]) {
865 		addr_len = nla_len(info->attrs[NLBL_UNLABEL_A_IPV4ADDR]);
866 		if (addr_len != sizeof(struct in_addr) &&
867 		    addr_len != nla_len(info->attrs[NLBL_UNLABEL_A_IPV4MASK]))
868 			return -EINVAL;
869 		*len = addr_len;
870 		*addr = nla_data(info->attrs[NLBL_UNLABEL_A_IPV4ADDR]);
871 		*mask = nla_data(info->attrs[NLBL_UNLABEL_A_IPV4MASK]);
872 		return 0;
873 	} else if (info->attrs[NLBL_UNLABEL_A_IPV6ADDR]) {
874 		addr_len = nla_len(info->attrs[NLBL_UNLABEL_A_IPV6ADDR]);
875 		if (addr_len != sizeof(struct in6_addr) &&
876 		    addr_len != nla_len(info->attrs[NLBL_UNLABEL_A_IPV6MASK]))
877 			return -EINVAL;
878 		*len = addr_len;
879 		*addr = nla_data(info->attrs[NLBL_UNLABEL_A_IPV6ADDR]);
880 		*mask = nla_data(info->attrs[NLBL_UNLABEL_A_IPV6MASK]);
881 		return 0;
882 	}
883 
884 	return -EINVAL;
885 }
886 
887 /*
888  * NetLabel Command Handlers
889  */
890 
891 /**
892  * netlbl_unlabel_accept - Handle an ACCEPT message
893  * @skb: the NETLINK buffer
894  * @info: the Generic NETLINK info block
895  *
896  * Description:
897  * Process a user generated ACCEPT message and set the accept flag accordingly.
898  * Returns zero on success, negative values on failure.
899  *
900  */
901 static int netlbl_unlabel_accept(struct sk_buff *skb, struct genl_info *info)
902 {
903 	u8 value;
904 	struct netlbl_audit audit_info;
905 
906 	if (info->attrs[NLBL_UNLABEL_A_ACPTFLG]) {
907 		value = nla_get_u8(info->attrs[NLBL_UNLABEL_A_ACPTFLG]);
908 		if (value == 1 || value == 0) {
909 			netlbl_netlink_auditinfo(skb, &audit_info);
910 			netlbl_unlabel_acceptflg_set(value, &audit_info);
911 			return 0;
912 		}
913 	}
914 
915 	return -EINVAL;
916 }
917 
918 /**
919  * netlbl_unlabel_list - Handle a LIST message
920  * @skb: the NETLINK buffer
921  * @info: the Generic NETLINK info block
922  *
923  * Description:
924  * Process a user generated LIST message and respond with the current status.
925  * Returns zero on success, negative values on failure.
926  *
927  */
928 static int netlbl_unlabel_list(struct sk_buff *skb, struct genl_info *info)
929 {
930 	int ret_val = -EINVAL;
931 	struct sk_buff *ans_skb;
932 	void *data;
933 
934 	ans_skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
935 	if (ans_skb == NULL)
936 		goto list_failure;
937 	data = genlmsg_put_reply(ans_skb, info, &netlbl_unlabel_gnl_family,
938 				 0, NLBL_UNLABEL_C_LIST);
939 	if (data == NULL) {
940 		ret_val = -ENOMEM;
941 		goto list_failure;
942 	}
943 
944 	ret_val = nla_put_u8(ans_skb,
945 			     NLBL_UNLABEL_A_ACPTFLG,
946 			     netlabel_unlabel_acceptflg);
947 	if (ret_val != 0)
948 		goto list_failure;
949 
950 	genlmsg_end(ans_skb, data);
951 	return genlmsg_reply(ans_skb, info);
952 
953 list_failure:
954 	kfree_skb(ans_skb);
955 	return ret_val;
956 }
957 
958 /**
959  * netlbl_unlabel_staticadd - Handle a STATICADD message
960  * @skb: the NETLINK buffer
961  * @info: the Generic NETLINK info block
962  *
963  * Description:
964  * Process a user generated STATICADD message and add a new unlabeled
965  * connection entry to the hash table.  Returns zero on success, negative
966  * values on failure.
967  *
968  */
969 static int netlbl_unlabel_staticadd(struct sk_buff *skb,
970 				    struct genl_info *info)
971 {
972 	int ret_val;
973 	char *dev_name;
974 	void *addr;
975 	void *mask;
976 	u32 addr_len;
977 	u32 secid;
978 	struct netlbl_audit audit_info;
979 
980 	/* Don't allow users to add both IPv4 and IPv6 addresses for a
981 	 * single entry.  However, allow users to create two entries, one each
982 	 * for IPv4 and IPv4, with the same LSM security context which should
983 	 * achieve the same result. */
984 	if (!info->attrs[NLBL_UNLABEL_A_SECCTX] ||
985 	    !info->attrs[NLBL_UNLABEL_A_IFACE] ||
986 	    !((!info->attrs[NLBL_UNLABEL_A_IPV4ADDR] ||
987 	       !info->attrs[NLBL_UNLABEL_A_IPV4MASK]) ^
988 	      (!info->attrs[NLBL_UNLABEL_A_IPV6ADDR] ||
989 	       !info->attrs[NLBL_UNLABEL_A_IPV6MASK])))
990 		return -EINVAL;
991 
992 	netlbl_netlink_auditinfo(skb, &audit_info);
993 
994 	ret_val = netlbl_unlabel_addrinfo_get(info, &addr, &mask, &addr_len);
995 	if (ret_val != 0)
996 		return ret_val;
997 	dev_name = nla_data(info->attrs[NLBL_UNLABEL_A_IFACE]);
998 	ret_val = security_secctx_to_secid(
999 		                  nla_data(info->attrs[NLBL_UNLABEL_A_SECCTX]),
1000 				  nla_len(info->attrs[NLBL_UNLABEL_A_SECCTX]),
1001 				  &secid);
1002 	if (ret_val != 0)
1003 		return ret_val;
1004 
1005 	return netlbl_unlhsh_add(&init_net,
1006 				 dev_name, addr, mask, addr_len, secid,
1007 				 &audit_info);
1008 }
1009 
1010 /**
1011  * netlbl_unlabel_staticadddef - Handle a STATICADDDEF message
1012  * @skb: the NETLINK buffer
1013  * @info: the Generic NETLINK info block
1014  *
1015  * Description:
1016  * Process a user generated STATICADDDEF message and add a new default
1017  * unlabeled connection entry.  Returns zero on success, negative values on
1018  * failure.
1019  *
1020  */
1021 static int netlbl_unlabel_staticadddef(struct sk_buff *skb,
1022 				       struct genl_info *info)
1023 {
1024 	int ret_val;
1025 	void *addr;
1026 	void *mask;
1027 	u32 addr_len;
1028 	u32 secid;
1029 	struct netlbl_audit audit_info;
1030 
1031 	/* Don't allow users to add both IPv4 and IPv6 addresses for a
1032 	 * single entry.  However, allow users to create two entries, one each
1033 	 * for IPv4 and IPv6, with the same LSM security context which should
1034 	 * achieve the same result. */
1035 	if (!info->attrs[NLBL_UNLABEL_A_SECCTX] ||
1036 	    !((!info->attrs[NLBL_UNLABEL_A_IPV4ADDR] ||
1037 	       !info->attrs[NLBL_UNLABEL_A_IPV4MASK]) ^
1038 	      (!info->attrs[NLBL_UNLABEL_A_IPV6ADDR] ||
1039 	       !info->attrs[NLBL_UNLABEL_A_IPV6MASK])))
1040 		return -EINVAL;
1041 
1042 	netlbl_netlink_auditinfo(skb, &audit_info);
1043 
1044 	ret_val = netlbl_unlabel_addrinfo_get(info, &addr, &mask, &addr_len);
1045 	if (ret_val != 0)
1046 		return ret_val;
1047 	ret_val = security_secctx_to_secid(
1048 		                  nla_data(info->attrs[NLBL_UNLABEL_A_SECCTX]),
1049 				  nla_len(info->attrs[NLBL_UNLABEL_A_SECCTX]),
1050 				  &secid);
1051 	if (ret_val != 0)
1052 		return ret_val;
1053 
1054 	return netlbl_unlhsh_add(&init_net,
1055 				 NULL, addr, mask, addr_len, secid,
1056 				 &audit_info);
1057 }
1058 
1059 /**
1060  * netlbl_unlabel_staticremove - Handle a STATICREMOVE message
1061  * @skb: the NETLINK buffer
1062  * @info: the Generic NETLINK info block
1063  *
1064  * Description:
1065  * Process a user generated STATICREMOVE message and remove the specified
1066  * unlabeled connection entry.  Returns zero on success, negative values on
1067  * failure.
1068  *
1069  */
1070 static int netlbl_unlabel_staticremove(struct sk_buff *skb,
1071 				       struct genl_info *info)
1072 {
1073 	int ret_val;
1074 	char *dev_name;
1075 	void *addr;
1076 	void *mask;
1077 	u32 addr_len;
1078 	struct netlbl_audit audit_info;
1079 
1080 	/* See the note in netlbl_unlabel_staticadd() about not allowing both
1081 	 * IPv4 and IPv6 in the same entry. */
1082 	if (!info->attrs[NLBL_UNLABEL_A_IFACE] ||
1083 	    !((!info->attrs[NLBL_UNLABEL_A_IPV4ADDR] ||
1084 	       !info->attrs[NLBL_UNLABEL_A_IPV4MASK]) ^
1085 	      (!info->attrs[NLBL_UNLABEL_A_IPV6ADDR] ||
1086 	       !info->attrs[NLBL_UNLABEL_A_IPV6MASK])))
1087 		return -EINVAL;
1088 
1089 	netlbl_netlink_auditinfo(skb, &audit_info);
1090 
1091 	ret_val = netlbl_unlabel_addrinfo_get(info, &addr, &mask, &addr_len);
1092 	if (ret_val != 0)
1093 		return ret_val;
1094 	dev_name = nla_data(info->attrs[NLBL_UNLABEL_A_IFACE]);
1095 
1096 	return netlbl_unlhsh_remove(&init_net,
1097 				    dev_name, addr, mask, addr_len,
1098 				    &audit_info);
1099 }
1100 
1101 /**
1102  * netlbl_unlabel_staticremovedef - Handle a STATICREMOVEDEF message
1103  * @skb: the NETLINK buffer
1104  * @info: the Generic NETLINK info block
1105  *
1106  * Description:
1107  * Process a user generated STATICREMOVEDEF message and remove the default
1108  * unlabeled connection entry.  Returns zero on success, negative values on
1109  * failure.
1110  *
1111  */
1112 static int netlbl_unlabel_staticremovedef(struct sk_buff *skb,
1113 					  struct genl_info *info)
1114 {
1115 	int ret_val;
1116 	void *addr;
1117 	void *mask;
1118 	u32 addr_len;
1119 	struct netlbl_audit audit_info;
1120 
1121 	/* See the note in netlbl_unlabel_staticadd() about not allowing both
1122 	 * IPv4 and IPv6 in the same entry. */
1123 	if (!((!info->attrs[NLBL_UNLABEL_A_IPV4ADDR] ||
1124 	       !info->attrs[NLBL_UNLABEL_A_IPV4MASK]) ^
1125 	      (!info->attrs[NLBL_UNLABEL_A_IPV6ADDR] ||
1126 	       !info->attrs[NLBL_UNLABEL_A_IPV6MASK])))
1127 		return -EINVAL;
1128 
1129 	netlbl_netlink_auditinfo(skb, &audit_info);
1130 
1131 	ret_val = netlbl_unlabel_addrinfo_get(info, &addr, &mask, &addr_len);
1132 	if (ret_val != 0)
1133 		return ret_val;
1134 
1135 	return netlbl_unlhsh_remove(&init_net,
1136 				    NULL, addr, mask, addr_len,
1137 				    &audit_info);
1138 }
1139 
1140 
1141 /**
1142  * netlbl_unlabel_staticlist_gen - Generate messages for STATICLIST[DEF]
1143  * @cmd: command/message
1144  * @iface: the interface entry
1145  * @addr4: the IPv4 address entry
1146  * @addr6: the IPv6 address entry
1147  * @arg: the netlbl_unlhsh_walk_arg structure
1148  *
1149  * Description:
1150  * This function is designed to be used to generate a response for a
1151  * STATICLIST or STATICLISTDEF message.  When called either @addr4 or @addr6
1152  * can be specified, not both, the other unspecified entry should be set to
1153  * NULL by the caller.  Returns the size of the message on success, negative
1154  * values on failure.
1155  *
1156  */
1157 static int netlbl_unlabel_staticlist_gen(u32 cmd,
1158 				       const struct netlbl_unlhsh_iface *iface,
1159 				       const struct netlbl_unlhsh_addr4 *addr4,
1160 				       const struct netlbl_unlhsh_addr6 *addr6,
1161 				       void *arg)
1162 {
1163 	int ret_val = -ENOMEM;
1164 	struct netlbl_unlhsh_walk_arg *cb_arg = arg;
1165 	struct net_device *dev;
1166 	void *data;
1167 	u32 secid;
1168 	char *secctx;
1169 	u32 secctx_len;
1170 
1171 	data = genlmsg_put(cb_arg->skb, NETLINK_CB(cb_arg->nl_cb->skb).pid,
1172 			   cb_arg->seq, &netlbl_unlabel_gnl_family,
1173 			   NLM_F_MULTI, cmd);
1174 	if (data == NULL)
1175 		goto list_cb_failure;
1176 
1177 	if (iface->ifindex > 0) {
1178 		dev = dev_get_by_index(&init_net, iface->ifindex);
1179 		if (!dev) {
1180 			ret_val = -ENODEV;
1181 			goto list_cb_failure;
1182 		}
1183 		ret_val = nla_put_string(cb_arg->skb,
1184 					 NLBL_UNLABEL_A_IFACE, dev->name);
1185 		dev_put(dev);
1186 		if (ret_val != 0)
1187 			goto list_cb_failure;
1188 	}
1189 
1190 	if (addr4) {
1191 		struct in_addr addr_struct;
1192 
1193 		addr_struct.s_addr = addr4->list.addr;
1194 		ret_val = nla_put(cb_arg->skb,
1195 				  NLBL_UNLABEL_A_IPV4ADDR,
1196 				  sizeof(struct in_addr),
1197 				  &addr_struct);
1198 		if (ret_val != 0)
1199 			goto list_cb_failure;
1200 
1201 		addr_struct.s_addr = addr4->list.mask;
1202 		ret_val = nla_put(cb_arg->skb,
1203 				  NLBL_UNLABEL_A_IPV4MASK,
1204 				  sizeof(struct in_addr),
1205 				  &addr_struct);
1206 		if (ret_val != 0)
1207 			goto list_cb_failure;
1208 
1209 		secid = addr4->secid;
1210 	} else {
1211 		ret_val = nla_put(cb_arg->skb,
1212 				  NLBL_UNLABEL_A_IPV6ADDR,
1213 				  sizeof(struct in6_addr),
1214 				  &addr6->list.addr);
1215 		if (ret_val != 0)
1216 			goto list_cb_failure;
1217 
1218 		ret_val = nla_put(cb_arg->skb,
1219 				  NLBL_UNLABEL_A_IPV6MASK,
1220 				  sizeof(struct in6_addr),
1221 				  &addr6->list.mask);
1222 		if (ret_val != 0)
1223 			goto list_cb_failure;
1224 
1225 		secid = addr6->secid;
1226 	}
1227 
1228 	ret_val = security_secid_to_secctx(secid, &secctx, &secctx_len);
1229 	if (ret_val != 0)
1230 		goto list_cb_failure;
1231 	ret_val = nla_put(cb_arg->skb,
1232 			  NLBL_UNLABEL_A_SECCTX,
1233 			  secctx_len,
1234 			  secctx);
1235 	security_release_secctx(secctx, secctx_len);
1236 	if (ret_val != 0)
1237 		goto list_cb_failure;
1238 
1239 	cb_arg->seq++;
1240 	return genlmsg_end(cb_arg->skb, data);
1241 
1242 list_cb_failure:
1243 	genlmsg_cancel(cb_arg->skb, data);
1244 	return ret_val;
1245 }
1246 
1247 /**
1248  * netlbl_unlabel_staticlist - Handle a STATICLIST message
1249  * @skb: the NETLINK buffer
1250  * @cb: the NETLINK callback
1251  *
1252  * Description:
1253  * Process a user generated STATICLIST message and dump the unlabeled
1254  * connection hash table in a form suitable for use in a kernel generated
1255  * STATICLIST message.  Returns the length of @skb.
1256  *
1257  */
1258 static int netlbl_unlabel_staticlist(struct sk_buff *skb,
1259 				     struct netlink_callback *cb)
1260 {
1261 	struct netlbl_unlhsh_walk_arg cb_arg;
1262 	u32 skip_bkt = cb->args[0];
1263 	u32 skip_chain = cb->args[1];
1264 	u32 skip_addr4 = cb->args[2];
1265 	u32 skip_addr6 = cb->args[3];
1266 	u32 iter_bkt;
1267 	u32 iter_chain = 0, iter_addr4 = 0, iter_addr6 = 0;
1268 	struct netlbl_unlhsh_iface *iface;
1269 	struct list_head *iter_list;
1270 	struct netlbl_af4list *addr4;
1271 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
1272 	struct netlbl_af6list *addr6;
1273 #endif
1274 
1275 	cb_arg.nl_cb = cb;
1276 	cb_arg.skb = skb;
1277 	cb_arg.seq = cb->nlh->nlmsg_seq;
1278 
1279 	rcu_read_lock();
1280 	for (iter_bkt = skip_bkt;
1281 	     iter_bkt < rcu_dereference(netlbl_unlhsh)->size;
1282 	     iter_bkt++, iter_chain = 0, iter_addr4 = 0, iter_addr6 = 0) {
1283 		iter_list = &rcu_dereference(netlbl_unlhsh)->tbl[iter_bkt];
1284 		list_for_each_entry_rcu(iface, iter_list, list) {
1285 			if (!iface->valid ||
1286 			    iter_chain++ < skip_chain)
1287 				continue;
1288 			netlbl_af4list_foreach_rcu(addr4,
1289 						   &iface->addr4_list) {
1290 				if (iter_addr4++ < skip_addr4)
1291 					continue;
1292 				if (netlbl_unlabel_staticlist_gen(
1293 					      NLBL_UNLABEL_C_STATICLIST,
1294 					      iface,
1295 					      netlbl_unlhsh_addr4_entry(addr4),
1296 					      NULL,
1297 					      &cb_arg) < 0) {
1298 					iter_addr4--;
1299 					iter_chain--;
1300 					goto unlabel_staticlist_return;
1301 				}
1302 			}
1303 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
1304 			netlbl_af6list_foreach_rcu(addr6,
1305 						   &iface->addr6_list) {
1306 				if (iter_addr6++ < skip_addr6)
1307 					continue;
1308 				if (netlbl_unlabel_staticlist_gen(
1309 					      NLBL_UNLABEL_C_STATICLIST,
1310 					      iface,
1311 					      NULL,
1312 					      netlbl_unlhsh_addr6_entry(addr6),
1313 					      &cb_arg) < 0) {
1314 					iter_addr6--;
1315 					iter_chain--;
1316 					goto unlabel_staticlist_return;
1317 				}
1318 			}
1319 #endif /* IPv6 */
1320 		}
1321 	}
1322 
1323 unlabel_staticlist_return:
1324 	rcu_read_unlock();
1325 	cb->args[0] = skip_bkt;
1326 	cb->args[1] = skip_chain;
1327 	cb->args[2] = skip_addr4;
1328 	cb->args[3] = skip_addr6;
1329 	return skb->len;
1330 }
1331 
1332 /**
1333  * netlbl_unlabel_staticlistdef - Handle a STATICLISTDEF message
1334  * @skb: the NETLINK buffer
1335  * @cb: the NETLINK callback
1336  *
1337  * Description:
1338  * Process a user generated STATICLISTDEF message and dump the default
1339  * unlabeled connection entry in a form suitable for use in a kernel generated
1340  * STATICLISTDEF message.  Returns the length of @skb.
1341  *
1342  */
1343 static int netlbl_unlabel_staticlistdef(struct sk_buff *skb,
1344 					struct netlink_callback *cb)
1345 {
1346 	struct netlbl_unlhsh_walk_arg cb_arg;
1347 	struct netlbl_unlhsh_iface *iface;
1348 	u32 skip_addr4 = cb->args[0];
1349 	u32 skip_addr6 = cb->args[1];
1350 	u32 iter_addr4 = 0;
1351 	struct netlbl_af4list *addr4;
1352 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
1353 	u32 iter_addr6 = 0;
1354 	struct netlbl_af6list *addr6;
1355 #endif
1356 
1357 	cb_arg.nl_cb = cb;
1358 	cb_arg.skb = skb;
1359 	cb_arg.seq = cb->nlh->nlmsg_seq;
1360 
1361 	rcu_read_lock();
1362 	iface = rcu_dereference(netlbl_unlhsh_def);
1363 	if (iface == NULL || !iface->valid)
1364 		goto unlabel_staticlistdef_return;
1365 
1366 	netlbl_af4list_foreach_rcu(addr4, &iface->addr4_list) {
1367 		if (iter_addr4++ < skip_addr4)
1368 			continue;
1369 		if (netlbl_unlabel_staticlist_gen(NLBL_UNLABEL_C_STATICLISTDEF,
1370 					      iface,
1371 					      netlbl_unlhsh_addr4_entry(addr4),
1372 					      NULL,
1373 					      &cb_arg) < 0) {
1374 			iter_addr4--;
1375 			goto unlabel_staticlistdef_return;
1376 		}
1377 	}
1378 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
1379 	netlbl_af6list_foreach_rcu(addr6, &iface->addr6_list) {
1380 		if (iter_addr6++ < skip_addr6)
1381 			continue;
1382 		if (netlbl_unlabel_staticlist_gen(NLBL_UNLABEL_C_STATICLISTDEF,
1383 					      iface,
1384 					      NULL,
1385 					      netlbl_unlhsh_addr6_entry(addr6),
1386 					      &cb_arg) < 0) {
1387 			iter_addr6--;
1388 			goto unlabel_staticlistdef_return;
1389 		}
1390 	}
1391 #endif /* IPv6 */
1392 
1393 unlabel_staticlistdef_return:
1394 	rcu_read_unlock();
1395 	cb->args[0] = skip_addr4;
1396 	cb->args[1] = skip_addr6;
1397 	return skb->len;
1398 }
1399 
1400 /*
1401  * NetLabel Generic NETLINK Command Definitions
1402  */
1403 
1404 static struct genl_ops netlbl_unlabel_genl_ops[] = {
1405 	{
1406 	.cmd = NLBL_UNLABEL_C_STATICADD,
1407 	.flags = GENL_ADMIN_PERM,
1408 	.policy = netlbl_unlabel_genl_policy,
1409 	.doit = netlbl_unlabel_staticadd,
1410 	.dumpit = NULL,
1411 	},
1412 	{
1413 	.cmd = NLBL_UNLABEL_C_STATICREMOVE,
1414 	.flags = GENL_ADMIN_PERM,
1415 	.policy = netlbl_unlabel_genl_policy,
1416 	.doit = netlbl_unlabel_staticremove,
1417 	.dumpit = NULL,
1418 	},
1419 	{
1420 	.cmd = NLBL_UNLABEL_C_STATICLIST,
1421 	.flags = 0,
1422 	.policy = netlbl_unlabel_genl_policy,
1423 	.doit = NULL,
1424 	.dumpit = netlbl_unlabel_staticlist,
1425 	},
1426 	{
1427 	.cmd = NLBL_UNLABEL_C_STATICADDDEF,
1428 	.flags = GENL_ADMIN_PERM,
1429 	.policy = netlbl_unlabel_genl_policy,
1430 	.doit = netlbl_unlabel_staticadddef,
1431 	.dumpit = NULL,
1432 	},
1433 	{
1434 	.cmd = NLBL_UNLABEL_C_STATICREMOVEDEF,
1435 	.flags = GENL_ADMIN_PERM,
1436 	.policy = netlbl_unlabel_genl_policy,
1437 	.doit = netlbl_unlabel_staticremovedef,
1438 	.dumpit = NULL,
1439 	},
1440 	{
1441 	.cmd = NLBL_UNLABEL_C_STATICLISTDEF,
1442 	.flags = 0,
1443 	.policy = netlbl_unlabel_genl_policy,
1444 	.doit = NULL,
1445 	.dumpit = netlbl_unlabel_staticlistdef,
1446 	},
1447 	{
1448 	.cmd = NLBL_UNLABEL_C_ACCEPT,
1449 	.flags = GENL_ADMIN_PERM,
1450 	.policy = netlbl_unlabel_genl_policy,
1451 	.doit = netlbl_unlabel_accept,
1452 	.dumpit = NULL,
1453 	},
1454 	{
1455 	.cmd = NLBL_UNLABEL_C_LIST,
1456 	.flags = 0,
1457 	.policy = netlbl_unlabel_genl_policy,
1458 	.doit = netlbl_unlabel_list,
1459 	.dumpit = NULL,
1460 	},
1461 };
1462 
1463 /*
1464  * NetLabel Generic NETLINK Protocol Functions
1465  */
1466 
1467 /**
1468  * netlbl_unlabel_genl_init - Register the Unlabeled NetLabel component
1469  *
1470  * Description:
1471  * Register the unlabeled packet NetLabel component with the Generic NETLINK
1472  * mechanism.  Returns zero on success, negative values on failure.
1473  *
1474  */
1475 int __init netlbl_unlabel_genl_init(void)
1476 {
1477 	int ret_val, i;
1478 
1479 	ret_val = genl_register_family(&netlbl_unlabel_gnl_family);
1480 	if (ret_val != 0)
1481 		return ret_val;
1482 
1483 	for (i = 0; i < ARRAY_SIZE(netlbl_unlabel_genl_ops); i++) {
1484 		ret_val = genl_register_ops(&netlbl_unlabel_gnl_family,
1485 				&netlbl_unlabel_genl_ops[i]);
1486 		if (ret_val != 0)
1487 			return ret_val;
1488 	}
1489 
1490 	return 0;
1491 }
1492 
1493 /*
1494  * NetLabel KAPI Hooks
1495  */
1496 
1497 static struct notifier_block netlbl_unlhsh_netdev_notifier = {
1498 	.notifier_call = netlbl_unlhsh_netdev_handler,
1499 };
1500 
1501 /**
1502  * netlbl_unlabel_init - Initialize the unlabeled connection hash table
1503  * @size: the number of bits to use for the hash buckets
1504  *
1505  * Description:
1506  * Initializes the unlabeled connection hash table and registers a network
1507  * device notification handler.  This function should only be called by the
1508  * NetLabel subsystem itself during initialization.  Returns zero on success,
1509  * non-zero values on error.
1510  *
1511  */
1512 int __init netlbl_unlabel_init(u32 size)
1513 {
1514 	u32 iter;
1515 	struct netlbl_unlhsh_tbl *hsh_tbl;
1516 
1517 	if (size == 0)
1518 		return -EINVAL;
1519 
1520 	hsh_tbl = kmalloc(sizeof(*hsh_tbl), GFP_KERNEL);
1521 	if (hsh_tbl == NULL)
1522 		return -ENOMEM;
1523 	hsh_tbl->size = 1 << size;
1524 	hsh_tbl->tbl = kcalloc(hsh_tbl->size,
1525 			       sizeof(struct list_head),
1526 			       GFP_KERNEL);
1527 	if (hsh_tbl->tbl == NULL) {
1528 		kfree(hsh_tbl);
1529 		return -ENOMEM;
1530 	}
1531 	for (iter = 0; iter < hsh_tbl->size; iter++)
1532 		INIT_LIST_HEAD(&hsh_tbl->tbl[iter]);
1533 
1534 	rcu_read_lock();
1535 	spin_lock(&netlbl_unlhsh_lock);
1536 	rcu_assign_pointer(netlbl_unlhsh, hsh_tbl);
1537 	spin_unlock(&netlbl_unlhsh_lock);
1538 	rcu_read_unlock();
1539 
1540 	register_netdevice_notifier(&netlbl_unlhsh_netdev_notifier);
1541 
1542 	return 0;
1543 }
1544 
1545 /**
1546  * netlbl_unlabel_getattr - Get the security attributes for an unlabled packet
1547  * @skb: the packet
1548  * @family: protocol family
1549  * @secattr: the security attributes
1550  *
1551  * Description:
1552  * Determine the security attributes, if any, for an unlabled packet and return
1553  * them in @secattr.  Returns zero on success and negative values on failure.
1554  *
1555  */
1556 int netlbl_unlabel_getattr(const struct sk_buff *skb,
1557 			   u16 family,
1558 			   struct netlbl_lsm_secattr *secattr)
1559 {
1560 	struct netlbl_unlhsh_iface *iface;
1561 
1562 	rcu_read_lock();
1563 	iface = netlbl_unlhsh_search_iface_def(skb->iif);
1564 	if (iface == NULL)
1565 		goto unlabel_getattr_nolabel;
1566 	switch (family) {
1567 	case PF_INET: {
1568 		struct iphdr *hdr4;
1569 		struct netlbl_af4list *addr4;
1570 
1571 		hdr4 = ip_hdr(skb);
1572 		addr4 = netlbl_af4list_search(hdr4->saddr,
1573 					      &iface->addr4_list);
1574 		if (addr4 == NULL)
1575 			goto unlabel_getattr_nolabel;
1576 		secattr->attr.secid = netlbl_unlhsh_addr4_entry(addr4)->secid;
1577 		break;
1578 	}
1579 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
1580 	case PF_INET6: {
1581 		struct ipv6hdr *hdr6;
1582 		struct netlbl_af6list *addr6;
1583 
1584 		hdr6 = ipv6_hdr(skb);
1585 		addr6 = netlbl_af6list_search(&hdr6->saddr,
1586 					      &iface->addr6_list);
1587 		if (addr6 == NULL)
1588 			goto unlabel_getattr_nolabel;
1589 		secattr->attr.secid = netlbl_unlhsh_addr6_entry(addr6)->secid;
1590 		break;
1591 	}
1592 #endif /* IPv6 */
1593 	default:
1594 		goto unlabel_getattr_nolabel;
1595 	}
1596 	rcu_read_unlock();
1597 
1598 	secattr->flags |= NETLBL_SECATTR_SECID;
1599 	secattr->type = NETLBL_NLTYPE_UNLABELED;
1600 	return 0;
1601 
1602 unlabel_getattr_nolabel:
1603 	rcu_read_unlock();
1604 	if (netlabel_unlabel_acceptflg == 0)
1605 		return -ENOMSG;
1606 	secattr->type = NETLBL_NLTYPE_UNLABELED;
1607 	return 0;
1608 }
1609 
1610 /**
1611  * netlbl_unlabel_defconf - Set the default config to allow unlabeled packets
1612  *
1613  * Description:
1614  * Set the default NetLabel configuration to allow incoming unlabeled packets
1615  * and to send unlabeled network traffic by default.
1616  *
1617  */
1618 int __init netlbl_unlabel_defconf(void)
1619 {
1620 	int ret_val;
1621 	struct netlbl_dom_map *entry;
1622 	struct netlbl_audit audit_info;
1623 
1624 	/* Only the kernel is allowed to call this function and the only time
1625 	 * it is called is at bootup before the audit subsystem is reporting
1626 	 * messages so don't worry to much about these values. */
1627 	security_task_getsecid(current, &audit_info.secid);
1628 	audit_info.loginuid = 0;
1629 	audit_info.sessionid = 0;
1630 
1631 	entry = kzalloc(sizeof(*entry), GFP_KERNEL);
1632 	if (entry == NULL)
1633 		return -ENOMEM;
1634 	entry->type = NETLBL_NLTYPE_UNLABELED;
1635 	ret_val = netlbl_domhsh_add_default(entry, &audit_info);
1636 	if (ret_val != 0)
1637 		return ret_val;
1638 
1639 	netlbl_unlabel_acceptflg_set(1, &audit_info);
1640 
1641 	return 0;
1642 }
1643