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@paul-moore.com>
9  *
10  */
11 
12 /*
13  * (c) Copyright Hewlett-Packard Development Company, L.P., 2006 - 2008
14  *
15  * This program is free software;  you can redistribute it and/or modify
16  * it under the terms of the GNU General Public License as published by
17  * the Free Software Foundation; either version 2 of the License, or
18  * (at your option) any later version.
19  *
20  * This program is distributed in the hope that it will be useful,
21  * but WITHOUT ANY WARRANTY;  without even the implied warranty of
22  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
23  * the GNU General Public License for more details.
24  *
25  * You should have received a copy of the GNU General Public License
26  * along with this program;  if not, 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 <linux/slab.h>
47 #include <net/sock.h>
48 #include <net/netlink.h>
49 #include <net/genetlink.h>
50 #include <net/ip.h>
51 #include <net/ipv6.h>
52 #include <net/net_namespace.h>
53 #include <net/netlabel.h>
54 #include <asm/bug.h>
55 #include <linux/atomic.h>
56 
57 #include "netlabel_user.h"
58 #include "netlabel_addrlist.h"
59 #include "netlabel_domainhash.h"
60 #include "netlabel_unlabeled.h"
61 #include "netlabel_mgmt.h"
62 
63 /* NOTE: at present we always use init's network namespace since we don't
64  *       presently support different namespaces even though the majority of
65  *       the functions in this file are "namespace safe" */
66 
67 /* The unlabeled connection hash table which we use to map network interfaces
68  * and addresses of unlabeled packets to a user specified secid value for the
69  * LSM.  The hash table is used to lookup the network interface entry
70  * (struct netlbl_unlhsh_iface) and then the interface entry is used to
71  * lookup an IP address match from an ordered list.  If a network interface
72  * match can not be found in the hash table then the default entry
73  * (netlbl_unlhsh_def) is used.  The IP address entry list
74  * (struct netlbl_unlhsh_addr) is ordered such that the entries with a
75  * larger netmask come first.
76  */
77 struct netlbl_unlhsh_tbl {
78 	struct list_head *tbl;
79 	u32 size;
80 };
81 #define netlbl_unlhsh_addr4_entry(iter) \
82 	container_of(iter, struct netlbl_unlhsh_addr4, list)
83 struct netlbl_unlhsh_addr4 {
84 	u32 secid;
85 
86 	struct netlbl_af4list list;
87 	struct rcu_head rcu;
88 };
89 #define netlbl_unlhsh_addr6_entry(iter) \
90 	container_of(iter, struct netlbl_unlhsh_addr6, list)
91 struct netlbl_unlhsh_addr6 {
92 	u32 secid;
93 
94 	struct netlbl_af6list list;
95 	struct rcu_head rcu;
96 };
97 struct netlbl_unlhsh_iface {
98 	int ifindex;
99 	struct list_head addr4_list;
100 	struct list_head addr6_list;
101 
102 	u32 valid;
103 	struct list_head list;
104 	struct rcu_head rcu;
105 };
106 
107 /* Argument struct for netlbl_unlhsh_walk() */
108 struct netlbl_unlhsh_walk_arg {
109 	struct netlink_callback *nl_cb;
110 	struct sk_buff *skb;
111 	u32 seq;
112 };
113 
114 /* Unlabeled connection hash table */
115 /* updates should be so rare that having one spinlock for the entire
116  * hash table should be okay */
117 static DEFINE_SPINLOCK(netlbl_unlhsh_lock);
118 #define netlbl_unlhsh_rcu_deref(p) \
119 	rcu_dereference_check(p, lockdep_is_held(&netlbl_unlhsh_lock))
120 static struct netlbl_unlhsh_tbl *netlbl_unlhsh = NULL;
121 static struct netlbl_unlhsh_iface *netlbl_unlhsh_def = NULL;
122 
123 /* Accept unlabeled packets flag */
124 static u8 netlabel_unlabel_acceptflg = 0;
125 
126 /* NetLabel Generic NETLINK unlabeled family */
127 static struct genl_family netlbl_unlabel_gnl_family = {
128 	.id = GENL_ID_GENERATE,
129 	.hdrsize = 0,
130 	.name = NETLBL_NLTYPE_UNLABELED_NAME,
131 	.version = NETLBL_PROTO_VERSION,
132 	.maxattr = NLBL_UNLABEL_A_MAX,
133 };
134 
135 /* NetLabel Netlink attribute policy */
136 static const struct nla_policy netlbl_unlabel_genl_policy[NLBL_UNLABEL_A_MAX + 1] = {
137 	[NLBL_UNLABEL_A_ACPTFLG] = { .type = NLA_U8 },
138 	[NLBL_UNLABEL_A_IPV6ADDR] = { .type = NLA_BINARY,
139 				      .len = sizeof(struct in6_addr) },
140 	[NLBL_UNLABEL_A_IPV6MASK] = { .type = NLA_BINARY,
141 				      .len = sizeof(struct in6_addr) },
142 	[NLBL_UNLABEL_A_IPV4ADDR] = { .type = NLA_BINARY,
143 				      .len = sizeof(struct in_addr) },
144 	[NLBL_UNLABEL_A_IPV4MASK] = { .type = NLA_BINARY,
145 				      .len = sizeof(struct in_addr) },
146 	[NLBL_UNLABEL_A_IFACE] = { .type = NLA_NUL_STRING,
147 				   .len = IFNAMSIZ - 1 },
148 	[NLBL_UNLABEL_A_SECCTX] = { .type = NLA_BINARY }
149 };
150 
151 /*
152  * Unlabeled Connection Hash Table Functions
153  */
154 
155 /**
156  * netlbl_unlhsh_free_iface - Frees an interface entry from the hash table
157  * @entry: the entry's RCU field
158  *
159  * Description:
160  * This function is designed to be used as a callback to the call_rcu()
161  * function so that memory allocated to a hash table interface entry can be
162  * released safely.  It is important to note that this function does not free
163  * the IPv4 and IPv6 address lists contained as part of an interface entry.  It
164  * is up to the rest of the code to make sure an interface entry is only freed
165  * once it's address lists are empty.
166  *
167  */
168 static void netlbl_unlhsh_free_iface(struct rcu_head *entry)
169 {
170 	struct netlbl_unlhsh_iface *iface;
171 	struct netlbl_af4list *iter4;
172 	struct netlbl_af4list *tmp4;
173 #if IS_ENABLED(CONFIG_IPV6)
174 	struct netlbl_af6list *iter6;
175 	struct netlbl_af6list *tmp6;
176 #endif /* IPv6 */
177 
178 	iface = container_of(entry, struct netlbl_unlhsh_iface, rcu);
179 
180 	/* no need for locks here since we are the only one with access to this
181 	 * structure */
182 
183 	netlbl_af4list_foreach_safe(iter4, tmp4, &iface->addr4_list) {
184 		netlbl_af4list_remove_entry(iter4);
185 		kfree(netlbl_unlhsh_addr4_entry(iter4));
186 	}
187 #if IS_ENABLED(CONFIG_IPV6)
188 	netlbl_af6list_foreach_safe(iter6, tmp6, &iface->addr6_list) {
189 		netlbl_af6list_remove_entry(iter6);
190 		kfree(netlbl_unlhsh_addr6_entry(iter6));
191 	}
192 #endif /* IPv6 */
193 	kfree(iface);
194 }
195 
196 /**
197  * netlbl_unlhsh_hash - Hashing function for the hash table
198  * @ifindex: the network interface/device to hash
199  *
200  * Description:
201  * This is the hashing function for the unlabeled hash table, it returns the
202  * bucket number for the given device/interface.  The caller is responsible for
203  * ensuring that the hash table is protected with either a RCU read lock or
204  * the hash table lock.
205  *
206  */
207 static u32 netlbl_unlhsh_hash(int ifindex)
208 {
209 	return ifindex & (netlbl_unlhsh_rcu_deref(netlbl_unlhsh)->size - 1);
210 }
211 
212 /**
213  * netlbl_unlhsh_search_iface - Search for a matching interface entry
214  * @ifindex: the network interface
215  *
216  * Description:
217  * Searches the unlabeled connection hash table and returns a pointer to the
218  * interface entry which matches @ifindex, otherwise NULL is returned.  The
219  * caller is responsible for ensuring that the hash table is protected with
220  * either a RCU read lock or the hash table lock.
221  *
222  */
223 static struct netlbl_unlhsh_iface *netlbl_unlhsh_search_iface(int ifindex)
224 {
225 	u32 bkt;
226 	struct list_head *bkt_list;
227 	struct netlbl_unlhsh_iface *iter;
228 
229 	bkt = netlbl_unlhsh_hash(ifindex);
230 	bkt_list = &netlbl_unlhsh_rcu_deref(netlbl_unlhsh)->tbl[bkt];
231 	list_for_each_entry_rcu(iter, bkt_list, list)
232 		if (iter->valid && iter->ifindex == ifindex)
233 			return iter;
234 
235 	return NULL;
236 }
237 
238 /**
239  * netlbl_unlhsh_add_addr4 - Add a new IPv4 address entry to the hash table
240  * @iface: the associated interface entry
241  * @addr: IPv4 address in network byte order
242  * @mask: IPv4 address mask in network byte order
243  * @secid: LSM secid value for entry
244  *
245  * Description:
246  * Add a new address entry into the unlabeled connection hash table using the
247  * interface entry specified by @iface.  On success zero is returned, otherwise
248  * a negative value is returned.
249  *
250  */
251 static int netlbl_unlhsh_add_addr4(struct netlbl_unlhsh_iface *iface,
252 				   const struct in_addr *addr,
253 				   const struct in_addr *mask,
254 				   u32 secid)
255 {
256 	int ret_val;
257 	struct netlbl_unlhsh_addr4 *entry;
258 
259 	entry = kzalloc(sizeof(*entry), GFP_ATOMIC);
260 	if (entry == NULL)
261 		return -ENOMEM;
262 
263 	entry->list.addr = addr->s_addr & mask->s_addr;
264 	entry->list.mask = mask->s_addr;
265 	entry->list.valid = 1;
266 	entry->secid = secid;
267 
268 	spin_lock(&netlbl_unlhsh_lock);
269 	ret_val = netlbl_af4list_add(&entry->list, &iface->addr4_list);
270 	spin_unlock(&netlbl_unlhsh_lock);
271 
272 	if (ret_val != 0)
273 		kfree(entry);
274 	return ret_val;
275 }
276 
277 #if IS_ENABLED(CONFIG_IPV6)
278 /**
279  * netlbl_unlhsh_add_addr6 - Add a new IPv6 address entry to the hash table
280  * @iface: the associated interface entry
281  * @addr: IPv6 address in network byte order
282  * @mask: IPv6 address mask in network byte order
283  * @secid: LSM secid value for entry
284  *
285  * Description:
286  * Add a new address entry into the unlabeled connection hash table using the
287  * interface entry specified by @iface.  On success zero is returned, otherwise
288  * a negative value is returned.
289  *
290  */
291 static int netlbl_unlhsh_add_addr6(struct netlbl_unlhsh_iface *iface,
292 				   const struct in6_addr *addr,
293 				   const struct in6_addr *mask,
294 				   u32 secid)
295 {
296 	int ret_val;
297 	struct netlbl_unlhsh_addr6 *entry;
298 
299 	entry = kzalloc(sizeof(*entry), GFP_ATOMIC);
300 	if (entry == NULL)
301 		return -ENOMEM;
302 
303 	entry->list.addr = *addr;
304 	entry->list.addr.s6_addr32[0] &= mask->s6_addr32[0];
305 	entry->list.addr.s6_addr32[1] &= mask->s6_addr32[1];
306 	entry->list.addr.s6_addr32[2] &= mask->s6_addr32[2];
307 	entry->list.addr.s6_addr32[3] &= mask->s6_addr32[3];
308 	entry->list.mask = *mask;
309 	entry->list.valid = 1;
310 	entry->secid = secid;
311 
312 	spin_lock(&netlbl_unlhsh_lock);
313 	ret_val = netlbl_af6list_add(&entry->list, &iface->addr6_list);
314 	spin_unlock(&netlbl_unlhsh_lock);
315 
316 	if (ret_val != 0)
317 		kfree(entry);
318 	return 0;
319 }
320 #endif /* IPv6 */
321 
322 /**
323  * netlbl_unlhsh_add_iface - Adds a new interface entry to the hash table
324  * @ifindex: network interface
325  *
326  * Description:
327  * Add a new, empty, interface entry into the unlabeled connection hash table.
328  * On success a pointer to the new interface entry is returned, on failure NULL
329  * is returned.
330  *
331  */
332 static struct netlbl_unlhsh_iface *netlbl_unlhsh_add_iface(int ifindex)
333 {
334 	u32 bkt;
335 	struct netlbl_unlhsh_iface *iface;
336 
337 	iface = kzalloc(sizeof(*iface), GFP_ATOMIC);
338 	if (iface == NULL)
339 		return NULL;
340 
341 	iface->ifindex = ifindex;
342 	INIT_LIST_HEAD(&iface->addr4_list);
343 	INIT_LIST_HEAD(&iface->addr6_list);
344 	iface->valid = 1;
345 
346 	spin_lock(&netlbl_unlhsh_lock);
347 	if (ifindex > 0) {
348 		bkt = netlbl_unlhsh_hash(ifindex);
349 		if (netlbl_unlhsh_search_iface(ifindex) != NULL)
350 			goto add_iface_failure;
351 		list_add_tail_rcu(&iface->list,
352 			     &netlbl_unlhsh_rcu_deref(netlbl_unlhsh)->tbl[bkt]);
353 	} else {
354 		INIT_LIST_HEAD(&iface->list);
355 		if (netlbl_unlhsh_rcu_deref(netlbl_unlhsh_def) != NULL)
356 			goto add_iface_failure;
357 		rcu_assign_pointer(netlbl_unlhsh_def, iface);
358 	}
359 	spin_unlock(&netlbl_unlhsh_lock);
360 
361 	return iface;
362 
363 add_iface_failure:
364 	spin_unlock(&netlbl_unlhsh_lock);
365 	kfree(iface);
366 	return NULL;
367 }
368 
369 /**
370  * netlbl_unlhsh_add - Adds a new entry to the unlabeled connection hash table
371  * @net: network namespace
372  * @dev_name: interface name
373  * @addr: IP address in network byte order
374  * @mask: address mask in network byte order
375  * @addr_len: length of address/mask (4 for IPv4, 16 for IPv6)
376  * @secid: LSM secid value for the entry
377  * @audit_info: NetLabel audit information
378  *
379  * Description:
380  * Adds a new entry to the unlabeled connection hash table.  Returns zero on
381  * success, negative values on failure.
382  *
383  */
384 int netlbl_unlhsh_add(struct net *net,
385 		      const char *dev_name,
386 		      const void *addr,
387 		      const void *mask,
388 		      u32 addr_len,
389 		      u32 secid,
390 		      struct netlbl_audit *audit_info)
391 {
392 	int ret_val;
393 	int ifindex;
394 	struct net_device *dev;
395 	struct netlbl_unlhsh_iface *iface;
396 	struct audit_buffer *audit_buf = NULL;
397 	char *secctx = NULL;
398 	u32 secctx_len;
399 
400 	if (addr_len != sizeof(struct in_addr) &&
401 	    addr_len != sizeof(struct in6_addr))
402 		return -EINVAL;
403 
404 	rcu_read_lock();
405 	if (dev_name != NULL) {
406 		dev = dev_get_by_name_rcu(net, dev_name);
407 		if (dev == NULL) {
408 			ret_val = -ENODEV;
409 			goto unlhsh_add_return;
410 		}
411 		ifindex = dev->ifindex;
412 		iface = netlbl_unlhsh_search_iface(ifindex);
413 	} else {
414 		ifindex = 0;
415 		iface = rcu_dereference(netlbl_unlhsh_def);
416 	}
417 	if (iface == NULL) {
418 		iface = netlbl_unlhsh_add_iface(ifindex);
419 		if (iface == NULL) {
420 			ret_val = -ENOMEM;
421 			goto unlhsh_add_return;
422 		}
423 	}
424 	audit_buf = netlbl_audit_start_common(AUDIT_MAC_UNLBL_STCADD,
425 					      audit_info);
426 	switch (addr_len) {
427 	case sizeof(struct in_addr): {
428 		const struct in_addr *addr4 = addr;
429 		const struct in_addr *mask4 = mask;
430 
431 		ret_val = netlbl_unlhsh_add_addr4(iface, addr4, mask4, secid);
432 		if (audit_buf != NULL)
433 			netlbl_af4list_audit_addr(audit_buf, 1,
434 						  dev_name,
435 						  addr4->s_addr,
436 						  mask4->s_addr);
437 		break;
438 	}
439 #if IS_ENABLED(CONFIG_IPV6)
440 	case sizeof(struct in6_addr): {
441 		const struct in6_addr *addr6 = addr;
442 		const struct in6_addr *mask6 = mask;
443 
444 		ret_val = netlbl_unlhsh_add_addr6(iface, addr6, mask6, secid);
445 		if (audit_buf != NULL)
446 			netlbl_af6list_audit_addr(audit_buf, 1,
447 						  dev_name,
448 						  addr6, mask6);
449 		break;
450 	}
451 #endif /* IPv6 */
452 	default:
453 		ret_val = -EINVAL;
454 	}
455 	if (ret_val == 0)
456 		atomic_inc(&netlabel_mgmt_protocount);
457 
458 unlhsh_add_return:
459 	rcu_read_unlock();
460 	if (audit_buf != NULL) {
461 		if (security_secid_to_secctx(secid,
462 					     &secctx,
463 					     &secctx_len) == 0) {
464 			audit_log_format(audit_buf, " sec_obj=%s", secctx);
465 			security_release_secctx(secctx, secctx_len);
466 		}
467 		audit_log_format(audit_buf, " res=%u", ret_val == 0 ? 1 : 0);
468 		audit_log_end(audit_buf);
469 	}
470 	return ret_val;
471 }
472 
473 /**
474  * netlbl_unlhsh_remove_addr4 - Remove an IPv4 address entry
475  * @net: network namespace
476  * @iface: interface entry
477  * @addr: IP address
478  * @mask: IP address mask
479  * @audit_info: NetLabel audit information
480  *
481  * Description:
482  * Remove an IP address entry from the unlabeled connection hash table.
483  * Returns zero on success, negative values on failure.
484  *
485  */
486 static int netlbl_unlhsh_remove_addr4(struct net *net,
487 				      struct netlbl_unlhsh_iface *iface,
488 				      const struct in_addr *addr,
489 				      const struct in_addr *mask,
490 				      struct netlbl_audit *audit_info)
491 {
492 	struct netlbl_af4list *list_entry;
493 	struct netlbl_unlhsh_addr4 *entry;
494 	struct audit_buffer *audit_buf;
495 	struct net_device *dev;
496 	char *secctx;
497 	u32 secctx_len;
498 
499 	spin_lock(&netlbl_unlhsh_lock);
500 	list_entry = netlbl_af4list_remove(addr->s_addr, mask->s_addr,
501 					   &iface->addr4_list);
502 	spin_unlock(&netlbl_unlhsh_lock);
503 	if (list_entry != NULL)
504 		entry = netlbl_unlhsh_addr4_entry(list_entry);
505 	else
506 		entry = NULL;
507 
508 	audit_buf = netlbl_audit_start_common(AUDIT_MAC_UNLBL_STCDEL,
509 					      audit_info);
510 	if (audit_buf != NULL) {
511 		dev = dev_get_by_index(net, iface->ifindex);
512 		netlbl_af4list_audit_addr(audit_buf, 1,
513 					  (dev != NULL ? dev->name : NULL),
514 					  addr->s_addr, mask->s_addr);
515 		if (dev != NULL)
516 			dev_put(dev);
517 		if (entry != NULL &&
518 		    security_secid_to_secctx(entry->secid,
519 					     &secctx, &secctx_len) == 0) {
520 			audit_log_format(audit_buf, " sec_obj=%s", secctx);
521 			security_release_secctx(secctx, secctx_len);
522 		}
523 		audit_log_format(audit_buf, " res=%u", entry != NULL ? 1 : 0);
524 		audit_log_end(audit_buf);
525 	}
526 
527 	if (entry == NULL)
528 		return -ENOENT;
529 
530 	kfree_rcu(entry, rcu);
531 	return 0;
532 }
533 
534 #if IS_ENABLED(CONFIG_IPV6)
535 /**
536  * netlbl_unlhsh_remove_addr6 - Remove an IPv6 address entry
537  * @net: network namespace
538  * @iface: interface entry
539  * @addr: IP address
540  * @mask: IP address mask
541  * @audit_info: NetLabel audit information
542  *
543  * Description:
544  * Remove an IP address entry from the unlabeled connection hash table.
545  * Returns zero on success, negative values on failure.
546  *
547  */
548 static int netlbl_unlhsh_remove_addr6(struct net *net,
549 				      struct netlbl_unlhsh_iface *iface,
550 				      const struct in6_addr *addr,
551 				      const struct in6_addr *mask,
552 				      struct netlbl_audit *audit_info)
553 {
554 	struct netlbl_af6list *list_entry;
555 	struct netlbl_unlhsh_addr6 *entry;
556 	struct audit_buffer *audit_buf;
557 	struct net_device *dev;
558 	char *secctx;
559 	u32 secctx_len;
560 
561 	spin_lock(&netlbl_unlhsh_lock);
562 	list_entry = netlbl_af6list_remove(addr, mask, &iface->addr6_list);
563 	spin_unlock(&netlbl_unlhsh_lock);
564 	if (list_entry != NULL)
565 		entry = netlbl_unlhsh_addr6_entry(list_entry);
566 	else
567 		entry = NULL;
568 
569 	audit_buf = netlbl_audit_start_common(AUDIT_MAC_UNLBL_STCDEL,
570 					      audit_info);
571 	if (audit_buf != NULL) {
572 		dev = dev_get_by_index(net, iface->ifindex);
573 		netlbl_af6list_audit_addr(audit_buf, 1,
574 					  (dev != NULL ? dev->name : NULL),
575 					  addr, mask);
576 		if (dev != NULL)
577 			dev_put(dev);
578 		if (entry != NULL &&
579 		    security_secid_to_secctx(entry->secid,
580 					     &secctx, &secctx_len) == 0) {
581 			audit_log_format(audit_buf, " sec_obj=%s", secctx);
582 			security_release_secctx(secctx, secctx_len);
583 		}
584 		audit_log_format(audit_buf, " res=%u", entry != NULL ? 1 : 0);
585 		audit_log_end(audit_buf);
586 	}
587 
588 	if (entry == NULL)
589 		return -ENOENT;
590 
591 	kfree_rcu(entry, rcu);
592 	return 0;
593 }
594 #endif /* IPv6 */
595 
596 /**
597  * netlbl_unlhsh_condremove_iface - Remove an interface entry
598  * @iface: the interface entry
599  *
600  * Description:
601  * Remove an interface entry from the unlabeled connection hash table if it is
602  * empty.  An interface entry is considered to be empty if there are no
603  * address entries assigned to it.
604  *
605  */
606 static void netlbl_unlhsh_condremove_iface(struct netlbl_unlhsh_iface *iface)
607 {
608 	struct netlbl_af4list *iter4;
609 #if IS_ENABLED(CONFIG_IPV6)
610 	struct netlbl_af6list *iter6;
611 #endif /* IPv6 */
612 
613 	spin_lock(&netlbl_unlhsh_lock);
614 	netlbl_af4list_foreach_rcu(iter4, &iface->addr4_list)
615 		goto unlhsh_condremove_failure;
616 #if IS_ENABLED(CONFIG_IPV6)
617 	netlbl_af6list_foreach_rcu(iter6, &iface->addr6_list)
618 		goto unlhsh_condremove_failure;
619 #endif /* IPv6 */
620 	iface->valid = 0;
621 	if (iface->ifindex > 0)
622 		list_del_rcu(&iface->list);
623 	else
624 		RCU_INIT_POINTER(netlbl_unlhsh_def, NULL);
625 	spin_unlock(&netlbl_unlhsh_lock);
626 
627 	call_rcu(&iface->rcu, netlbl_unlhsh_free_iface);
628 	return;
629 
630 unlhsh_condremove_failure:
631 	spin_unlock(&netlbl_unlhsh_lock);
632 }
633 
634 /**
635  * netlbl_unlhsh_remove - Remove an entry from the unlabeled hash table
636  * @net: network namespace
637  * @dev_name: interface name
638  * @addr: IP address in network byte order
639  * @mask: address mask in network byte order
640  * @addr_len: length of address/mask (4 for IPv4, 16 for IPv6)
641  * @audit_info: NetLabel audit information
642  *
643  * Description:
644  * Removes and existing entry from the unlabeled connection hash table.
645  * Returns zero on success, negative values on failure.
646  *
647  */
648 int netlbl_unlhsh_remove(struct net *net,
649 			 const char *dev_name,
650 			 const void *addr,
651 			 const void *mask,
652 			 u32 addr_len,
653 			 struct netlbl_audit *audit_info)
654 {
655 	int ret_val;
656 	struct net_device *dev;
657 	struct netlbl_unlhsh_iface *iface;
658 
659 	if (addr_len != sizeof(struct in_addr) &&
660 	    addr_len != sizeof(struct in6_addr))
661 		return -EINVAL;
662 
663 	rcu_read_lock();
664 	if (dev_name != NULL) {
665 		dev = dev_get_by_name_rcu(net, dev_name);
666 		if (dev == NULL) {
667 			ret_val = -ENODEV;
668 			goto unlhsh_remove_return;
669 		}
670 		iface = netlbl_unlhsh_search_iface(dev->ifindex);
671 	} else
672 		iface = rcu_dereference(netlbl_unlhsh_def);
673 	if (iface == NULL) {
674 		ret_val = -ENOENT;
675 		goto unlhsh_remove_return;
676 	}
677 	switch (addr_len) {
678 	case sizeof(struct in_addr):
679 		ret_val = netlbl_unlhsh_remove_addr4(net,
680 						     iface, addr, mask,
681 						     audit_info);
682 		break;
683 #if IS_ENABLED(CONFIG_IPV6)
684 	case sizeof(struct in6_addr):
685 		ret_val = netlbl_unlhsh_remove_addr6(net,
686 						     iface, addr, mask,
687 						     audit_info);
688 		break;
689 #endif /* IPv6 */
690 	default:
691 		ret_val = -EINVAL;
692 	}
693 	if (ret_val == 0) {
694 		netlbl_unlhsh_condremove_iface(iface);
695 		atomic_dec(&netlabel_mgmt_protocount);
696 	}
697 
698 unlhsh_remove_return:
699 	rcu_read_unlock();
700 	return ret_val;
701 }
702 
703 /*
704  * General Helper Functions
705  */
706 
707 /**
708  * netlbl_unlhsh_netdev_handler - Network device notification handler
709  * @this: notifier block
710  * @event: the event
711  * @ptr: the netdevice notifier info (cast to void)
712  *
713  * Description:
714  * Handle network device events, although at present all we care about is a
715  * network device going away.  In the case of a device going away we clear any
716  * related entries from the unlabeled connection hash table.
717  *
718  */
719 static int netlbl_unlhsh_netdev_handler(struct notifier_block *this,
720 					unsigned long event, void *ptr)
721 {
722 	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
723 	struct netlbl_unlhsh_iface *iface = NULL;
724 
725 	if (!net_eq(dev_net(dev), &init_net))
726 		return NOTIFY_DONE;
727 
728 	/* XXX - should this be a check for NETDEV_DOWN or _UNREGISTER? */
729 	if (event == NETDEV_DOWN) {
730 		spin_lock(&netlbl_unlhsh_lock);
731 		iface = netlbl_unlhsh_search_iface(dev->ifindex);
732 		if (iface != NULL && iface->valid) {
733 			iface->valid = 0;
734 			list_del_rcu(&iface->list);
735 		} else
736 			iface = NULL;
737 		spin_unlock(&netlbl_unlhsh_lock);
738 	}
739 
740 	if (iface != NULL)
741 		call_rcu(&iface->rcu, netlbl_unlhsh_free_iface);
742 
743 	return NOTIFY_DONE;
744 }
745 
746 /**
747  * netlbl_unlabel_acceptflg_set - Set the unlabeled accept flag
748  * @value: desired value
749  * @audit_info: NetLabel audit information
750  *
751  * Description:
752  * Set the value of the unlabeled accept flag to @value.
753  *
754  */
755 static void netlbl_unlabel_acceptflg_set(u8 value,
756 					 struct netlbl_audit *audit_info)
757 {
758 	struct audit_buffer *audit_buf;
759 	u8 old_val;
760 
761 	old_val = netlabel_unlabel_acceptflg;
762 	netlabel_unlabel_acceptflg = value;
763 	audit_buf = netlbl_audit_start_common(AUDIT_MAC_UNLBL_ALLOW,
764 					      audit_info);
765 	if (audit_buf != NULL) {
766 		audit_log_format(audit_buf,
767 				 " unlbl_accept=%u old=%u", value, old_val);
768 		audit_log_end(audit_buf);
769 	}
770 }
771 
772 /**
773  * netlbl_unlabel_addrinfo_get - Get the IPv4/6 address information
774  * @info: the Generic NETLINK info block
775  * @addr: the IP address
776  * @mask: the IP address mask
777  * @len: the address length
778  *
779  * Description:
780  * Examine the Generic NETLINK message and extract the IP address information.
781  * Returns zero on success, negative values on failure.
782  *
783  */
784 static int netlbl_unlabel_addrinfo_get(struct genl_info *info,
785 				       void **addr,
786 				       void **mask,
787 				       u32 *len)
788 {
789 	u32 addr_len;
790 
791 	if (info->attrs[NLBL_UNLABEL_A_IPV4ADDR]) {
792 		addr_len = nla_len(info->attrs[NLBL_UNLABEL_A_IPV4ADDR]);
793 		if (addr_len != sizeof(struct in_addr) &&
794 		    addr_len != nla_len(info->attrs[NLBL_UNLABEL_A_IPV4MASK]))
795 			return -EINVAL;
796 		*len = addr_len;
797 		*addr = nla_data(info->attrs[NLBL_UNLABEL_A_IPV4ADDR]);
798 		*mask = nla_data(info->attrs[NLBL_UNLABEL_A_IPV4MASK]);
799 		return 0;
800 	} else if (info->attrs[NLBL_UNLABEL_A_IPV6ADDR]) {
801 		addr_len = nla_len(info->attrs[NLBL_UNLABEL_A_IPV6ADDR]);
802 		if (addr_len != sizeof(struct in6_addr) &&
803 		    addr_len != nla_len(info->attrs[NLBL_UNLABEL_A_IPV6MASK]))
804 			return -EINVAL;
805 		*len = addr_len;
806 		*addr = nla_data(info->attrs[NLBL_UNLABEL_A_IPV6ADDR]);
807 		*mask = nla_data(info->attrs[NLBL_UNLABEL_A_IPV6MASK]);
808 		return 0;
809 	}
810 
811 	return -EINVAL;
812 }
813 
814 /*
815  * NetLabel Command Handlers
816  */
817 
818 /**
819  * netlbl_unlabel_accept - Handle an ACCEPT message
820  * @skb: the NETLINK buffer
821  * @info: the Generic NETLINK info block
822  *
823  * Description:
824  * Process a user generated ACCEPT message and set the accept flag accordingly.
825  * Returns zero on success, negative values on failure.
826  *
827  */
828 static int netlbl_unlabel_accept(struct sk_buff *skb, struct genl_info *info)
829 {
830 	u8 value;
831 	struct netlbl_audit audit_info;
832 
833 	if (info->attrs[NLBL_UNLABEL_A_ACPTFLG]) {
834 		value = nla_get_u8(info->attrs[NLBL_UNLABEL_A_ACPTFLG]);
835 		if (value == 1 || value == 0) {
836 			netlbl_netlink_auditinfo(skb, &audit_info);
837 			netlbl_unlabel_acceptflg_set(value, &audit_info);
838 			return 0;
839 		}
840 	}
841 
842 	return -EINVAL;
843 }
844 
845 /**
846  * netlbl_unlabel_list - Handle a LIST message
847  * @skb: the NETLINK buffer
848  * @info: the Generic NETLINK info block
849  *
850  * Description:
851  * Process a user generated LIST message and respond with the current status.
852  * Returns zero on success, negative values on failure.
853  *
854  */
855 static int netlbl_unlabel_list(struct sk_buff *skb, struct genl_info *info)
856 {
857 	int ret_val = -EINVAL;
858 	struct sk_buff *ans_skb;
859 	void *data;
860 
861 	ans_skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
862 	if (ans_skb == NULL)
863 		goto list_failure;
864 	data = genlmsg_put_reply(ans_skb, info, &netlbl_unlabel_gnl_family,
865 				 0, NLBL_UNLABEL_C_LIST);
866 	if (data == NULL) {
867 		ret_val = -ENOMEM;
868 		goto list_failure;
869 	}
870 
871 	ret_val = nla_put_u8(ans_skb,
872 			     NLBL_UNLABEL_A_ACPTFLG,
873 			     netlabel_unlabel_acceptflg);
874 	if (ret_val != 0)
875 		goto list_failure;
876 
877 	genlmsg_end(ans_skb, data);
878 	return genlmsg_reply(ans_skb, info);
879 
880 list_failure:
881 	kfree_skb(ans_skb);
882 	return ret_val;
883 }
884 
885 /**
886  * netlbl_unlabel_staticadd - Handle a STATICADD message
887  * @skb: the NETLINK buffer
888  * @info: the Generic NETLINK info block
889  *
890  * Description:
891  * Process a user generated STATICADD message and add a new unlabeled
892  * connection entry to the hash table.  Returns zero on success, negative
893  * values on failure.
894  *
895  */
896 static int netlbl_unlabel_staticadd(struct sk_buff *skb,
897 				    struct genl_info *info)
898 {
899 	int ret_val;
900 	char *dev_name;
901 	void *addr;
902 	void *mask;
903 	u32 addr_len;
904 	u32 secid;
905 	struct netlbl_audit audit_info;
906 
907 	/* Don't allow users to add both IPv4 and IPv6 addresses for a
908 	 * single entry.  However, allow users to create two entries, one each
909 	 * for IPv4 and IPv4, with the same LSM security context which should
910 	 * achieve the same result. */
911 	if (!info->attrs[NLBL_UNLABEL_A_SECCTX] ||
912 	    !info->attrs[NLBL_UNLABEL_A_IFACE] ||
913 	    !((!info->attrs[NLBL_UNLABEL_A_IPV4ADDR] ||
914 	       !info->attrs[NLBL_UNLABEL_A_IPV4MASK]) ^
915 	      (!info->attrs[NLBL_UNLABEL_A_IPV6ADDR] ||
916 	       !info->attrs[NLBL_UNLABEL_A_IPV6MASK])))
917 		return -EINVAL;
918 
919 	netlbl_netlink_auditinfo(skb, &audit_info);
920 
921 	ret_val = netlbl_unlabel_addrinfo_get(info, &addr, &mask, &addr_len);
922 	if (ret_val != 0)
923 		return ret_val;
924 	dev_name = nla_data(info->attrs[NLBL_UNLABEL_A_IFACE]);
925 	ret_val = security_secctx_to_secid(
926 		                  nla_data(info->attrs[NLBL_UNLABEL_A_SECCTX]),
927 				  nla_len(info->attrs[NLBL_UNLABEL_A_SECCTX]),
928 				  &secid);
929 	if (ret_val != 0)
930 		return ret_val;
931 
932 	return netlbl_unlhsh_add(&init_net,
933 				 dev_name, addr, mask, addr_len, secid,
934 				 &audit_info);
935 }
936 
937 /**
938  * netlbl_unlabel_staticadddef - Handle a STATICADDDEF message
939  * @skb: the NETLINK buffer
940  * @info: the Generic NETLINK info block
941  *
942  * Description:
943  * Process a user generated STATICADDDEF message and add a new default
944  * unlabeled connection entry.  Returns zero on success, negative values on
945  * failure.
946  *
947  */
948 static int netlbl_unlabel_staticadddef(struct sk_buff *skb,
949 				       struct genl_info *info)
950 {
951 	int ret_val;
952 	void *addr;
953 	void *mask;
954 	u32 addr_len;
955 	u32 secid;
956 	struct netlbl_audit audit_info;
957 
958 	/* Don't allow users to add both IPv4 and IPv6 addresses for a
959 	 * single entry.  However, allow users to create two entries, one each
960 	 * for IPv4 and IPv6, with the same LSM security context which should
961 	 * achieve the same result. */
962 	if (!info->attrs[NLBL_UNLABEL_A_SECCTX] ||
963 	    !((!info->attrs[NLBL_UNLABEL_A_IPV4ADDR] ||
964 	       !info->attrs[NLBL_UNLABEL_A_IPV4MASK]) ^
965 	      (!info->attrs[NLBL_UNLABEL_A_IPV6ADDR] ||
966 	       !info->attrs[NLBL_UNLABEL_A_IPV6MASK])))
967 		return -EINVAL;
968 
969 	netlbl_netlink_auditinfo(skb, &audit_info);
970 
971 	ret_val = netlbl_unlabel_addrinfo_get(info, &addr, &mask, &addr_len);
972 	if (ret_val != 0)
973 		return ret_val;
974 	ret_val = security_secctx_to_secid(
975 		                  nla_data(info->attrs[NLBL_UNLABEL_A_SECCTX]),
976 				  nla_len(info->attrs[NLBL_UNLABEL_A_SECCTX]),
977 				  &secid);
978 	if (ret_val != 0)
979 		return ret_val;
980 
981 	return netlbl_unlhsh_add(&init_net,
982 				 NULL, addr, mask, addr_len, secid,
983 				 &audit_info);
984 }
985 
986 /**
987  * netlbl_unlabel_staticremove - Handle a STATICREMOVE message
988  * @skb: the NETLINK buffer
989  * @info: the Generic NETLINK info block
990  *
991  * Description:
992  * Process a user generated STATICREMOVE message and remove the specified
993  * unlabeled connection entry.  Returns zero on success, negative values on
994  * failure.
995  *
996  */
997 static int netlbl_unlabel_staticremove(struct sk_buff *skb,
998 				       struct genl_info *info)
999 {
1000 	int ret_val;
1001 	char *dev_name;
1002 	void *addr;
1003 	void *mask;
1004 	u32 addr_len;
1005 	struct netlbl_audit audit_info;
1006 
1007 	/* See the note in netlbl_unlabel_staticadd() about not allowing both
1008 	 * IPv4 and IPv6 in the same entry. */
1009 	if (!info->attrs[NLBL_UNLABEL_A_IFACE] ||
1010 	    !((!info->attrs[NLBL_UNLABEL_A_IPV4ADDR] ||
1011 	       !info->attrs[NLBL_UNLABEL_A_IPV4MASK]) ^
1012 	      (!info->attrs[NLBL_UNLABEL_A_IPV6ADDR] ||
1013 	       !info->attrs[NLBL_UNLABEL_A_IPV6MASK])))
1014 		return -EINVAL;
1015 
1016 	netlbl_netlink_auditinfo(skb, &audit_info);
1017 
1018 	ret_val = netlbl_unlabel_addrinfo_get(info, &addr, &mask, &addr_len);
1019 	if (ret_val != 0)
1020 		return ret_val;
1021 	dev_name = nla_data(info->attrs[NLBL_UNLABEL_A_IFACE]);
1022 
1023 	return netlbl_unlhsh_remove(&init_net,
1024 				    dev_name, addr, mask, addr_len,
1025 				    &audit_info);
1026 }
1027 
1028 /**
1029  * netlbl_unlabel_staticremovedef - Handle a STATICREMOVEDEF message
1030  * @skb: the NETLINK buffer
1031  * @info: the Generic NETLINK info block
1032  *
1033  * Description:
1034  * Process a user generated STATICREMOVEDEF message and remove the default
1035  * unlabeled connection entry.  Returns zero on success, negative values on
1036  * failure.
1037  *
1038  */
1039 static int netlbl_unlabel_staticremovedef(struct sk_buff *skb,
1040 					  struct genl_info *info)
1041 {
1042 	int ret_val;
1043 	void *addr;
1044 	void *mask;
1045 	u32 addr_len;
1046 	struct netlbl_audit audit_info;
1047 
1048 	/* See the note in netlbl_unlabel_staticadd() about not allowing both
1049 	 * IPv4 and IPv6 in the same entry. */
1050 	if (!((!info->attrs[NLBL_UNLABEL_A_IPV4ADDR] ||
1051 	       !info->attrs[NLBL_UNLABEL_A_IPV4MASK]) ^
1052 	      (!info->attrs[NLBL_UNLABEL_A_IPV6ADDR] ||
1053 	       !info->attrs[NLBL_UNLABEL_A_IPV6MASK])))
1054 		return -EINVAL;
1055 
1056 	netlbl_netlink_auditinfo(skb, &audit_info);
1057 
1058 	ret_val = netlbl_unlabel_addrinfo_get(info, &addr, &mask, &addr_len);
1059 	if (ret_val != 0)
1060 		return ret_val;
1061 
1062 	return netlbl_unlhsh_remove(&init_net,
1063 				    NULL, addr, mask, addr_len,
1064 				    &audit_info);
1065 }
1066 
1067 
1068 /**
1069  * netlbl_unlabel_staticlist_gen - Generate messages for STATICLIST[DEF]
1070  * @cmd: command/message
1071  * @iface: the interface entry
1072  * @addr4: the IPv4 address entry
1073  * @addr6: the IPv6 address entry
1074  * @arg: the netlbl_unlhsh_walk_arg structure
1075  *
1076  * Description:
1077  * This function is designed to be used to generate a response for a
1078  * STATICLIST or STATICLISTDEF message.  When called either @addr4 or @addr6
1079  * can be specified, not both, the other unspecified entry should be set to
1080  * NULL by the caller.  Returns the size of the message on success, negative
1081  * values on failure.
1082  *
1083  */
1084 static int netlbl_unlabel_staticlist_gen(u32 cmd,
1085 				       const struct netlbl_unlhsh_iface *iface,
1086 				       const struct netlbl_unlhsh_addr4 *addr4,
1087 				       const struct netlbl_unlhsh_addr6 *addr6,
1088 				       void *arg)
1089 {
1090 	int ret_val = -ENOMEM;
1091 	struct netlbl_unlhsh_walk_arg *cb_arg = arg;
1092 	struct net_device *dev;
1093 	void *data;
1094 	u32 secid;
1095 	char *secctx;
1096 	u32 secctx_len;
1097 
1098 	data = genlmsg_put(cb_arg->skb, NETLINK_CB(cb_arg->nl_cb->skb).portid,
1099 			   cb_arg->seq, &netlbl_unlabel_gnl_family,
1100 			   NLM_F_MULTI, cmd);
1101 	if (data == NULL)
1102 		goto list_cb_failure;
1103 
1104 	if (iface->ifindex > 0) {
1105 		dev = dev_get_by_index(&init_net, iface->ifindex);
1106 		if (!dev) {
1107 			ret_val = -ENODEV;
1108 			goto list_cb_failure;
1109 		}
1110 		ret_val = nla_put_string(cb_arg->skb,
1111 					 NLBL_UNLABEL_A_IFACE, dev->name);
1112 		dev_put(dev);
1113 		if (ret_val != 0)
1114 			goto list_cb_failure;
1115 	}
1116 
1117 	if (addr4) {
1118 		struct in_addr addr_struct;
1119 
1120 		addr_struct.s_addr = addr4->list.addr;
1121 		ret_val = nla_put(cb_arg->skb,
1122 				  NLBL_UNLABEL_A_IPV4ADDR,
1123 				  sizeof(struct in_addr),
1124 				  &addr_struct);
1125 		if (ret_val != 0)
1126 			goto list_cb_failure;
1127 
1128 		addr_struct.s_addr = addr4->list.mask;
1129 		ret_val = nla_put(cb_arg->skb,
1130 				  NLBL_UNLABEL_A_IPV4MASK,
1131 				  sizeof(struct in_addr),
1132 				  &addr_struct);
1133 		if (ret_val != 0)
1134 			goto list_cb_failure;
1135 
1136 		secid = addr4->secid;
1137 	} else {
1138 		ret_val = nla_put(cb_arg->skb,
1139 				  NLBL_UNLABEL_A_IPV6ADDR,
1140 				  sizeof(struct in6_addr),
1141 				  &addr6->list.addr);
1142 		if (ret_val != 0)
1143 			goto list_cb_failure;
1144 
1145 		ret_val = nla_put(cb_arg->skb,
1146 				  NLBL_UNLABEL_A_IPV6MASK,
1147 				  sizeof(struct in6_addr),
1148 				  &addr6->list.mask);
1149 		if (ret_val != 0)
1150 			goto list_cb_failure;
1151 
1152 		secid = addr6->secid;
1153 	}
1154 
1155 	ret_val = security_secid_to_secctx(secid, &secctx, &secctx_len);
1156 	if (ret_val != 0)
1157 		goto list_cb_failure;
1158 	ret_val = nla_put(cb_arg->skb,
1159 			  NLBL_UNLABEL_A_SECCTX,
1160 			  secctx_len,
1161 			  secctx);
1162 	security_release_secctx(secctx, secctx_len);
1163 	if (ret_val != 0)
1164 		goto list_cb_failure;
1165 
1166 	cb_arg->seq++;
1167 	return genlmsg_end(cb_arg->skb, data);
1168 
1169 list_cb_failure:
1170 	genlmsg_cancel(cb_arg->skb, data);
1171 	return ret_val;
1172 }
1173 
1174 /**
1175  * netlbl_unlabel_staticlist - Handle a STATICLIST message
1176  * @skb: the NETLINK buffer
1177  * @cb: the NETLINK callback
1178  *
1179  * Description:
1180  * Process a user generated STATICLIST message and dump the unlabeled
1181  * connection hash table in a form suitable for use in a kernel generated
1182  * STATICLIST message.  Returns the length of @skb.
1183  *
1184  */
1185 static int netlbl_unlabel_staticlist(struct sk_buff *skb,
1186 				     struct netlink_callback *cb)
1187 {
1188 	struct netlbl_unlhsh_walk_arg cb_arg;
1189 	u32 skip_bkt = cb->args[0];
1190 	u32 skip_chain = cb->args[1];
1191 	u32 iter_bkt;
1192 	u32 iter_chain = 0, iter_addr4 = 0, iter_addr6 = 0;
1193 	struct netlbl_unlhsh_iface *iface;
1194 	struct list_head *iter_list;
1195 	struct netlbl_af4list *addr4;
1196 #if IS_ENABLED(CONFIG_IPV6)
1197 	struct netlbl_af6list *addr6;
1198 #endif
1199 
1200 	cb_arg.nl_cb = cb;
1201 	cb_arg.skb = skb;
1202 	cb_arg.seq = cb->nlh->nlmsg_seq;
1203 
1204 	rcu_read_lock();
1205 	for (iter_bkt = skip_bkt;
1206 	     iter_bkt < rcu_dereference(netlbl_unlhsh)->size;
1207 	     iter_bkt++, iter_chain = 0, iter_addr4 = 0, iter_addr6 = 0) {
1208 		iter_list = &rcu_dereference(netlbl_unlhsh)->tbl[iter_bkt];
1209 		list_for_each_entry_rcu(iface, iter_list, list) {
1210 			if (!iface->valid ||
1211 			    iter_chain++ < skip_chain)
1212 				continue;
1213 			netlbl_af4list_foreach_rcu(addr4,
1214 						   &iface->addr4_list) {
1215 				if (iter_addr4++ < cb->args[2])
1216 					continue;
1217 				if (netlbl_unlabel_staticlist_gen(
1218 					      NLBL_UNLABEL_C_STATICLIST,
1219 					      iface,
1220 					      netlbl_unlhsh_addr4_entry(addr4),
1221 					      NULL,
1222 					      &cb_arg) < 0) {
1223 					iter_addr4--;
1224 					iter_chain--;
1225 					goto unlabel_staticlist_return;
1226 				}
1227 			}
1228 #if IS_ENABLED(CONFIG_IPV6)
1229 			netlbl_af6list_foreach_rcu(addr6,
1230 						   &iface->addr6_list) {
1231 				if (iter_addr6++ < cb->args[3])
1232 					continue;
1233 				if (netlbl_unlabel_staticlist_gen(
1234 					      NLBL_UNLABEL_C_STATICLIST,
1235 					      iface,
1236 					      NULL,
1237 					      netlbl_unlhsh_addr6_entry(addr6),
1238 					      &cb_arg) < 0) {
1239 					iter_addr6--;
1240 					iter_chain--;
1241 					goto unlabel_staticlist_return;
1242 				}
1243 			}
1244 #endif /* IPv6 */
1245 		}
1246 	}
1247 
1248 unlabel_staticlist_return:
1249 	rcu_read_unlock();
1250 	cb->args[0] = iter_bkt;
1251 	cb->args[1] = iter_chain;
1252 	cb->args[2] = iter_addr4;
1253 	cb->args[3] = iter_addr6;
1254 	return skb->len;
1255 }
1256 
1257 /**
1258  * netlbl_unlabel_staticlistdef - Handle a STATICLISTDEF message
1259  * @skb: the NETLINK buffer
1260  * @cb: the NETLINK callback
1261  *
1262  * Description:
1263  * Process a user generated STATICLISTDEF message and dump the default
1264  * unlabeled connection entry in a form suitable for use in a kernel generated
1265  * STATICLISTDEF message.  Returns the length of @skb.
1266  *
1267  */
1268 static int netlbl_unlabel_staticlistdef(struct sk_buff *skb,
1269 					struct netlink_callback *cb)
1270 {
1271 	struct netlbl_unlhsh_walk_arg cb_arg;
1272 	struct netlbl_unlhsh_iface *iface;
1273 	u32 iter_addr4 = 0, iter_addr6 = 0;
1274 	struct netlbl_af4list *addr4;
1275 #if IS_ENABLED(CONFIG_IPV6)
1276 	struct netlbl_af6list *addr6;
1277 #endif
1278 
1279 	cb_arg.nl_cb = cb;
1280 	cb_arg.skb = skb;
1281 	cb_arg.seq = cb->nlh->nlmsg_seq;
1282 
1283 	rcu_read_lock();
1284 	iface = rcu_dereference(netlbl_unlhsh_def);
1285 	if (iface == NULL || !iface->valid)
1286 		goto unlabel_staticlistdef_return;
1287 
1288 	netlbl_af4list_foreach_rcu(addr4, &iface->addr4_list) {
1289 		if (iter_addr4++ < cb->args[0])
1290 			continue;
1291 		if (netlbl_unlabel_staticlist_gen(NLBL_UNLABEL_C_STATICLISTDEF,
1292 					      iface,
1293 					      netlbl_unlhsh_addr4_entry(addr4),
1294 					      NULL,
1295 					      &cb_arg) < 0) {
1296 			iter_addr4--;
1297 			goto unlabel_staticlistdef_return;
1298 		}
1299 	}
1300 #if IS_ENABLED(CONFIG_IPV6)
1301 	netlbl_af6list_foreach_rcu(addr6, &iface->addr6_list) {
1302 		if (iter_addr6++ < cb->args[1])
1303 			continue;
1304 		if (netlbl_unlabel_staticlist_gen(NLBL_UNLABEL_C_STATICLISTDEF,
1305 					      iface,
1306 					      NULL,
1307 					      netlbl_unlhsh_addr6_entry(addr6),
1308 					      &cb_arg) < 0) {
1309 			iter_addr6--;
1310 			goto unlabel_staticlistdef_return;
1311 		}
1312 	}
1313 #endif /* IPv6 */
1314 
1315 unlabel_staticlistdef_return:
1316 	rcu_read_unlock();
1317 	cb->args[0] = iter_addr4;
1318 	cb->args[1] = iter_addr6;
1319 	return skb->len;
1320 }
1321 
1322 /*
1323  * NetLabel Generic NETLINK Command Definitions
1324  */
1325 
1326 static const struct genl_ops netlbl_unlabel_genl_ops[] = {
1327 	{
1328 	.cmd = NLBL_UNLABEL_C_STATICADD,
1329 	.flags = GENL_ADMIN_PERM,
1330 	.policy = netlbl_unlabel_genl_policy,
1331 	.doit = netlbl_unlabel_staticadd,
1332 	.dumpit = NULL,
1333 	},
1334 	{
1335 	.cmd = NLBL_UNLABEL_C_STATICREMOVE,
1336 	.flags = GENL_ADMIN_PERM,
1337 	.policy = netlbl_unlabel_genl_policy,
1338 	.doit = netlbl_unlabel_staticremove,
1339 	.dumpit = NULL,
1340 	},
1341 	{
1342 	.cmd = NLBL_UNLABEL_C_STATICLIST,
1343 	.flags = 0,
1344 	.policy = netlbl_unlabel_genl_policy,
1345 	.doit = NULL,
1346 	.dumpit = netlbl_unlabel_staticlist,
1347 	},
1348 	{
1349 	.cmd = NLBL_UNLABEL_C_STATICADDDEF,
1350 	.flags = GENL_ADMIN_PERM,
1351 	.policy = netlbl_unlabel_genl_policy,
1352 	.doit = netlbl_unlabel_staticadddef,
1353 	.dumpit = NULL,
1354 	},
1355 	{
1356 	.cmd = NLBL_UNLABEL_C_STATICREMOVEDEF,
1357 	.flags = GENL_ADMIN_PERM,
1358 	.policy = netlbl_unlabel_genl_policy,
1359 	.doit = netlbl_unlabel_staticremovedef,
1360 	.dumpit = NULL,
1361 	},
1362 	{
1363 	.cmd = NLBL_UNLABEL_C_STATICLISTDEF,
1364 	.flags = 0,
1365 	.policy = netlbl_unlabel_genl_policy,
1366 	.doit = NULL,
1367 	.dumpit = netlbl_unlabel_staticlistdef,
1368 	},
1369 	{
1370 	.cmd = NLBL_UNLABEL_C_ACCEPT,
1371 	.flags = GENL_ADMIN_PERM,
1372 	.policy = netlbl_unlabel_genl_policy,
1373 	.doit = netlbl_unlabel_accept,
1374 	.dumpit = NULL,
1375 	},
1376 	{
1377 	.cmd = NLBL_UNLABEL_C_LIST,
1378 	.flags = 0,
1379 	.policy = netlbl_unlabel_genl_policy,
1380 	.doit = netlbl_unlabel_list,
1381 	.dumpit = NULL,
1382 	},
1383 };
1384 
1385 /*
1386  * NetLabel Generic NETLINK Protocol Functions
1387  */
1388 
1389 /**
1390  * netlbl_unlabel_genl_init - Register the Unlabeled NetLabel component
1391  *
1392  * Description:
1393  * Register the unlabeled packet NetLabel component with the Generic NETLINK
1394  * mechanism.  Returns zero on success, negative values on failure.
1395  *
1396  */
1397 int __init netlbl_unlabel_genl_init(void)
1398 {
1399 	return genl_register_family_with_ops(&netlbl_unlabel_gnl_family,
1400 					     netlbl_unlabel_genl_ops);
1401 }
1402 
1403 /*
1404  * NetLabel KAPI Hooks
1405  */
1406 
1407 static struct notifier_block netlbl_unlhsh_netdev_notifier = {
1408 	.notifier_call = netlbl_unlhsh_netdev_handler,
1409 };
1410 
1411 /**
1412  * netlbl_unlabel_init - Initialize the unlabeled connection hash table
1413  * @size: the number of bits to use for the hash buckets
1414  *
1415  * Description:
1416  * Initializes the unlabeled connection hash table and registers a network
1417  * device notification handler.  This function should only be called by the
1418  * NetLabel subsystem itself during initialization.  Returns zero on success,
1419  * non-zero values on error.
1420  *
1421  */
1422 int __init netlbl_unlabel_init(u32 size)
1423 {
1424 	u32 iter;
1425 	struct netlbl_unlhsh_tbl *hsh_tbl;
1426 
1427 	if (size == 0)
1428 		return -EINVAL;
1429 
1430 	hsh_tbl = kmalloc(sizeof(*hsh_tbl), GFP_KERNEL);
1431 	if (hsh_tbl == NULL)
1432 		return -ENOMEM;
1433 	hsh_tbl->size = 1 << size;
1434 	hsh_tbl->tbl = kcalloc(hsh_tbl->size,
1435 			       sizeof(struct list_head),
1436 			       GFP_KERNEL);
1437 	if (hsh_tbl->tbl == NULL) {
1438 		kfree(hsh_tbl);
1439 		return -ENOMEM;
1440 	}
1441 	for (iter = 0; iter < hsh_tbl->size; iter++)
1442 		INIT_LIST_HEAD(&hsh_tbl->tbl[iter]);
1443 
1444 	spin_lock(&netlbl_unlhsh_lock);
1445 	rcu_assign_pointer(netlbl_unlhsh, hsh_tbl);
1446 	spin_unlock(&netlbl_unlhsh_lock);
1447 
1448 	register_netdevice_notifier(&netlbl_unlhsh_netdev_notifier);
1449 
1450 	return 0;
1451 }
1452 
1453 /**
1454  * netlbl_unlabel_getattr - Get the security attributes for an unlabled packet
1455  * @skb: the packet
1456  * @family: protocol family
1457  * @secattr: the security attributes
1458  *
1459  * Description:
1460  * Determine the security attributes, if any, for an unlabled packet and return
1461  * them in @secattr.  Returns zero on success and negative values on failure.
1462  *
1463  */
1464 int netlbl_unlabel_getattr(const struct sk_buff *skb,
1465 			   u16 family,
1466 			   struct netlbl_lsm_secattr *secattr)
1467 {
1468 	struct netlbl_unlhsh_iface *iface;
1469 
1470 	rcu_read_lock();
1471 	iface = netlbl_unlhsh_search_iface(skb->skb_iif);
1472 	if (iface == NULL)
1473 		iface = rcu_dereference(netlbl_unlhsh_def);
1474 	if (iface == NULL || !iface->valid)
1475 		goto unlabel_getattr_nolabel;
1476 	switch (family) {
1477 	case PF_INET: {
1478 		struct iphdr *hdr4;
1479 		struct netlbl_af4list *addr4;
1480 
1481 		hdr4 = ip_hdr(skb);
1482 		addr4 = netlbl_af4list_search(hdr4->saddr,
1483 					      &iface->addr4_list);
1484 		if (addr4 == NULL)
1485 			goto unlabel_getattr_nolabel;
1486 		secattr->attr.secid = netlbl_unlhsh_addr4_entry(addr4)->secid;
1487 		break;
1488 	}
1489 #if IS_ENABLED(CONFIG_IPV6)
1490 	case PF_INET6: {
1491 		struct ipv6hdr *hdr6;
1492 		struct netlbl_af6list *addr6;
1493 
1494 		hdr6 = ipv6_hdr(skb);
1495 		addr6 = netlbl_af6list_search(&hdr6->saddr,
1496 					      &iface->addr6_list);
1497 		if (addr6 == NULL)
1498 			goto unlabel_getattr_nolabel;
1499 		secattr->attr.secid = netlbl_unlhsh_addr6_entry(addr6)->secid;
1500 		break;
1501 	}
1502 #endif /* IPv6 */
1503 	default:
1504 		goto unlabel_getattr_nolabel;
1505 	}
1506 	rcu_read_unlock();
1507 
1508 	secattr->flags |= NETLBL_SECATTR_SECID;
1509 	secattr->type = NETLBL_NLTYPE_UNLABELED;
1510 	return 0;
1511 
1512 unlabel_getattr_nolabel:
1513 	rcu_read_unlock();
1514 	if (netlabel_unlabel_acceptflg == 0)
1515 		return -ENOMSG;
1516 	secattr->type = NETLBL_NLTYPE_UNLABELED;
1517 	return 0;
1518 }
1519 
1520 /**
1521  * netlbl_unlabel_defconf - Set the default config to allow unlabeled packets
1522  *
1523  * Description:
1524  * Set the default NetLabel configuration to allow incoming unlabeled packets
1525  * and to send unlabeled network traffic by default.
1526  *
1527  */
1528 int __init netlbl_unlabel_defconf(void)
1529 {
1530 	int ret_val;
1531 	struct netlbl_dom_map *entry;
1532 	struct netlbl_audit audit_info;
1533 
1534 	/* Only the kernel is allowed to call this function and the only time
1535 	 * it is called is at bootup before the audit subsystem is reporting
1536 	 * messages so don't worry to much about these values. */
1537 	security_task_getsecid(current, &audit_info.secid);
1538 	audit_info.loginuid = GLOBAL_ROOT_UID;
1539 	audit_info.sessionid = 0;
1540 
1541 	entry = kzalloc(sizeof(*entry), GFP_KERNEL);
1542 	if (entry == NULL)
1543 		return -ENOMEM;
1544 	entry->def.type = NETLBL_NLTYPE_UNLABELED;
1545 	ret_val = netlbl_domhsh_add_default(entry, &audit_info);
1546 	if (ret_val != 0)
1547 		return ret_val;
1548 
1549 	netlbl_unlabel_acceptflg_set(1, &audit_info);
1550 
1551 	return 0;
1552 }
1553