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, see <http://www.gnu.org/licenses/>.
27 *
28 */
29
30 #include <linux/types.h>
31 #include <linux/rcupdate.h>
32 #include <linux/list.h>
33 #include <linux/spinlock.h>
34 #include <linux/socket.h>
35 #include <linux/string.h>
36 #include <linux/skbuff.h>
37 #include <linux/audit.h>
38 #include <linux/in.h>
39 #include <linux/in6.h>
40 #include <linux/ip.h>
41 #include <linux/ipv6.h>
42 #include <linux/notifier.h>
43 #include <linux/netdevice.h>
44 #include <linux/security.h>
45 #include <linux/slab.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 <linux/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 #define netlbl_unlhsh_rcu_deref(p) \
118 rcu_dereference_check(p, lockdep_is_held(&netlbl_unlhsh_lock))
119 static struct netlbl_unlhsh_tbl *netlbl_unlhsh = NULL;
120 static struct netlbl_unlhsh_iface *netlbl_unlhsh_def = NULL;
121
122 /* Accept unlabeled packets flag */
123 static u8 netlabel_unlabel_acceptflg = 0;
124
125 /* NetLabel Generic NETLINK unlabeled family */
126 static struct genl_family netlbl_unlabel_gnl_family = {
127 .id = GENL_ID_GENERATE,
128 .hdrsize = 0,
129 .name = NETLBL_NLTYPE_UNLABELED_NAME,
130 .version = NETLBL_PROTO_VERSION,
131 .maxattr = NLBL_UNLABEL_A_MAX,
132 };
133
134 /* NetLabel Netlink attribute policy */
135 static const struct nla_policy netlbl_unlabel_genl_policy[NLBL_UNLABEL_A_MAX + 1] = {
136 [NLBL_UNLABEL_A_ACPTFLG] = { .type = NLA_U8 },
137 [NLBL_UNLABEL_A_IPV6ADDR] = { .type = NLA_BINARY,
138 .len = sizeof(struct in6_addr) },
139 [NLBL_UNLABEL_A_IPV6MASK] = { .type = NLA_BINARY,
140 .len = sizeof(struct in6_addr) },
141 [NLBL_UNLABEL_A_IPV4ADDR] = { .type = NLA_BINARY,
142 .len = sizeof(struct in_addr) },
143 [NLBL_UNLABEL_A_IPV4MASK] = { .type = NLA_BINARY,
144 .len = sizeof(struct in_addr) },
145 [NLBL_UNLABEL_A_IFACE] = { .type = NLA_NUL_STRING,
146 .len = IFNAMSIZ - 1 },
147 [NLBL_UNLABEL_A_SECCTX] = { .type = NLA_BINARY }
148 };
149
150 /*
151 * Unlabeled Connection Hash Table Functions
152 */
153
154 /**
155 * netlbl_unlhsh_free_iface - Frees an interface entry from the hash table
156 * @entry: the entry's RCU field
157 *
158 * Description:
159 * This function is designed to be used as a callback to the call_rcu()
160 * function so that memory allocated to a hash table interface entry can be
161 * released safely. It is important to note that this function does not free
162 * the IPv4 and IPv6 address lists contained as part of an interface entry. It
163 * is up to the rest of the code to make sure an interface entry is only freed
164 * once it's address lists are empty.
165 *
166 */
netlbl_unlhsh_free_iface(struct rcu_head * entry)167 static void netlbl_unlhsh_free_iface(struct rcu_head *entry)
168 {
169 struct netlbl_unlhsh_iface *iface;
170 struct netlbl_af4list *iter4;
171 struct netlbl_af4list *tmp4;
172 #if IS_ENABLED(CONFIG_IPV6)
173 struct netlbl_af6list *iter6;
174 struct netlbl_af6list *tmp6;
175 #endif /* IPv6 */
176
177 iface = container_of(entry, struct netlbl_unlhsh_iface, rcu);
178
179 /* no need for locks here since we are the only one with access to this
180 * structure */
181
182 netlbl_af4list_foreach_safe(iter4, tmp4, &iface->addr4_list) {
183 netlbl_af4list_remove_entry(iter4);
184 kfree(netlbl_unlhsh_addr4_entry(iter4));
185 }
186 #if IS_ENABLED(CONFIG_IPV6)
187 netlbl_af6list_foreach_safe(iter6, tmp6, &iface->addr6_list) {
188 netlbl_af6list_remove_entry(iter6);
189 kfree(netlbl_unlhsh_addr6_entry(iter6));
190 }
191 #endif /* IPv6 */
192 kfree(iface);
193 }
194
195 /**
196 * netlbl_unlhsh_hash - Hashing function for the hash table
197 * @ifindex: the network interface/device to hash
198 *
199 * Description:
200 * This is the hashing function for the unlabeled hash table, it returns the
201 * bucket number for the given device/interface. The caller is responsible for
202 * ensuring that the hash table is protected with either a RCU read lock or
203 * the hash table lock.
204 *
205 */
netlbl_unlhsh_hash(int ifindex)206 static u32 netlbl_unlhsh_hash(int ifindex)
207 {
208 return ifindex & (netlbl_unlhsh_rcu_deref(netlbl_unlhsh)->size - 1);
209 }
210
211 /**
212 * netlbl_unlhsh_search_iface - Search for a matching interface entry
213 * @ifindex: the network interface
214 *
215 * Description:
216 * Searches the unlabeled connection hash table and returns a pointer to the
217 * interface entry which matches @ifindex, otherwise NULL is returned. The
218 * caller is responsible for ensuring that the hash table is protected with
219 * either a RCU read lock or the hash table lock.
220 *
221 */
netlbl_unlhsh_search_iface(int ifindex)222 static struct netlbl_unlhsh_iface *netlbl_unlhsh_search_iface(int ifindex)
223 {
224 u32 bkt;
225 struct list_head *bkt_list;
226 struct netlbl_unlhsh_iface *iter;
227
228 bkt = netlbl_unlhsh_hash(ifindex);
229 bkt_list = &netlbl_unlhsh_rcu_deref(netlbl_unlhsh)->tbl[bkt];
230 list_for_each_entry_rcu(iter, bkt_list, list)
231 if (iter->valid && iter->ifindex == ifindex)
232 return iter;
233
234 return NULL;
235 }
236
237 /**
238 * netlbl_unlhsh_add_addr4 - Add a new IPv4 address entry to the hash table
239 * @iface: the associated interface entry
240 * @addr: IPv4 address in network byte order
241 * @mask: IPv4 address mask in network byte order
242 * @secid: LSM secid value for entry
243 *
244 * Description:
245 * Add a new address entry into the unlabeled connection hash table using the
246 * interface entry specified by @iface. On success zero is returned, otherwise
247 * a negative value is returned.
248 *
249 */
netlbl_unlhsh_add_addr4(struct netlbl_unlhsh_iface * iface,const struct in_addr * addr,const struct in_addr * mask,u32 secid)250 static int netlbl_unlhsh_add_addr4(struct netlbl_unlhsh_iface *iface,
251 const struct in_addr *addr,
252 const struct in_addr *mask,
253 u32 secid)
254 {
255 int ret_val;
256 struct netlbl_unlhsh_addr4 *entry;
257
258 entry = kzalloc(sizeof(*entry), GFP_ATOMIC);
259 if (entry == NULL)
260 return -ENOMEM;
261
262 entry->list.addr = addr->s_addr & mask->s_addr;
263 entry->list.mask = mask->s_addr;
264 entry->list.valid = 1;
265 entry->secid = secid;
266
267 spin_lock(&netlbl_unlhsh_lock);
268 ret_val = netlbl_af4list_add(&entry->list, &iface->addr4_list);
269 spin_unlock(&netlbl_unlhsh_lock);
270
271 if (ret_val != 0)
272 kfree(entry);
273 return ret_val;
274 }
275
276 #if IS_ENABLED(CONFIG_IPV6)
277 /**
278 * netlbl_unlhsh_add_addr6 - Add a new IPv6 address entry to the hash table
279 * @iface: the associated interface entry
280 * @addr: IPv6 address in network byte order
281 * @mask: IPv6 address mask in network byte order
282 * @secid: LSM secid value for entry
283 *
284 * Description:
285 * Add a new address entry into the unlabeled connection hash table using the
286 * interface entry specified by @iface. On success zero is returned, otherwise
287 * a negative value is returned.
288 *
289 */
netlbl_unlhsh_add_addr6(struct netlbl_unlhsh_iface * iface,const struct in6_addr * addr,const struct in6_addr * mask,u32 secid)290 static int netlbl_unlhsh_add_addr6(struct netlbl_unlhsh_iface *iface,
291 const struct in6_addr *addr,
292 const struct in6_addr *mask,
293 u32 secid)
294 {
295 int ret_val;
296 struct netlbl_unlhsh_addr6 *entry;
297
298 entry = kzalloc(sizeof(*entry), GFP_ATOMIC);
299 if (entry == NULL)
300 return -ENOMEM;
301
302 entry->list.addr = *addr;
303 entry->list.addr.s6_addr32[0] &= mask->s6_addr32[0];
304 entry->list.addr.s6_addr32[1] &= mask->s6_addr32[1];
305 entry->list.addr.s6_addr32[2] &= mask->s6_addr32[2];
306 entry->list.addr.s6_addr32[3] &= mask->s6_addr32[3];
307 entry->list.mask = *mask;
308 entry->list.valid = 1;
309 entry->secid = secid;
310
311 spin_lock(&netlbl_unlhsh_lock);
312 ret_val = netlbl_af6list_add(&entry->list, &iface->addr6_list);
313 spin_unlock(&netlbl_unlhsh_lock);
314
315 if (ret_val != 0)
316 kfree(entry);
317 return 0;
318 }
319 #endif /* IPv6 */
320
321 /**
322 * netlbl_unlhsh_add_iface - Adds a new interface entry to the hash table
323 * @ifindex: network interface
324 *
325 * Description:
326 * Add a new, empty, interface entry into the unlabeled connection hash table.
327 * On success a pointer to the new interface entry is returned, on failure NULL
328 * is returned.
329 *
330 */
netlbl_unlhsh_add_iface(int ifindex)331 static struct netlbl_unlhsh_iface *netlbl_unlhsh_add_iface(int ifindex)
332 {
333 u32 bkt;
334 struct netlbl_unlhsh_iface *iface;
335
336 iface = kzalloc(sizeof(*iface), GFP_ATOMIC);
337 if (iface == NULL)
338 return NULL;
339
340 iface->ifindex = ifindex;
341 INIT_LIST_HEAD(&iface->addr4_list);
342 INIT_LIST_HEAD(&iface->addr6_list);
343 iface->valid = 1;
344
345 spin_lock(&netlbl_unlhsh_lock);
346 if (ifindex > 0) {
347 bkt = netlbl_unlhsh_hash(ifindex);
348 if (netlbl_unlhsh_search_iface(ifindex) != NULL)
349 goto add_iface_failure;
350 list_add_tail_rcu(&iface->list,
351 &netlbl_unlhsh_rcu_deref(netlbl_unlhsh)->tbl[bkt]);
352 } else {
353 INIT_LIST_HEAD(&iface->list);
354 if (netlbl_unlhsh_rcu_deref(netlbl_unlhsh_def) != NULL)
355 goto add_iface_failure;
356 rcu_assign_pointer(netlbl_unlhsh_def, iface);
357 }
358 spin_unlock(&netlbl_unlhsh_lock);
359
360 return iface;
361
362 add_iface_failure:
363 spin_unlock(&netlbl_unlhsh_lock);
364 kfree(iface);
365 return NULL;
366 }
367
368 /**
369 * netlbl_unlhsh_add - Adds a new entry to the unlabeled connection hash table
370 * @net: network namespace
371 * @dev_name: interface name
372 * @addr: IP address in network byte order
373 * @mask: address mask in network byte order
374 * @addr_len: length of address/mask (4 for IPv4, 16 for IPv6)
375 * @secid: LSM secid value for the entry
376 * @audit_info: NetLabel audit information
377 *
378 * Description:
379 * Adds a new entry to the unlabeled connection hash table. Returns zero on
380 * success, negative values on failure.
381 *
382 */
netlbl_unlhsh_add(struct net * net,const char * dev_name,const void * addr,const void * mask,u32 addr_len,u32 secid,struct netlbl_audit * audit_info)383 int netlbl_unlhsh_add(struct net *net,
384 const char *dev_name,
385 const void *addr,
386 const void *mask,
387 u32 addr_len,
388 u32 secid,
389 struct netlbl_audit *audit_info)
390 {
391 int ret_val;
392 int ifindex;
393 struct net_device *dev;
394 struct netlbl_unlhsh_iface *iface;
395 struct audit_buffer *audit_buf = NULL;
396 char *secctx = NULL;
397 u32 secctx_len;
398
399 if (addr_len != sizeof(struct in_addr) &&
400 addr_len != sizeof(struct in6_addr))
401 return -EINVAL;
402
403 rcu_read_lock();
404 if (dev_name != NULL) {
405 dev = dev_get_by_name_rcu(net, dev_name);
406 if (dev == NULL) {
407 ret_val = -ENODEV;
408 goto unlhsh_add_return;
409 }
410 ifindex = dev->ifindex;
411 iface = netlbl_unlhsh_search_iface(ifindex);
412 } else {
413 ifindex = 0;
414 iface = rcu_dereference(netlbl_unlhsh_def);
415 }
416 if (iface == NULL) {
417 iface = netlbl_unlhsh_add_iface(ifindex);
418 if (iface == NULL) {
419 ret_val = -ENOMEM;
420 goto unlhsh_add_return;
421 }
422 }
423 audit_buf = netlbl_audit_start_common(AUDIT_MAC_UNLBL_STCADD,
424 audit_info);
425 switch (addr_len) {
426 case sizeof(struct in_addr): {
427 const struct in_addr *addr4 = addr;
428 const struct in_addr *mask4 = mask;
429
430 ret_val = netlbl_unlhsh_add_addr4(iface, addr4, mask4, secid);
431 if (audit_buf != NULL)
432 netlbl_af4list_audit_addr(audit_buf, 1,
433 dev_name,
434 addr4->s_addr,
435 mask4->s_addr);
436 break;
437 }
438 #if IS_ENABLED(CONFIG_IPV6)
439 case sizeof(struct in6_addr): {
440 const struct in6_addr *addr6 = addr;
441 const struct in6_addr *mask6 = mask;
442
443 ret_val = netlbl_unlhsh_add_addr6(iface, addr6, mask6, secid);
444 if (audit_buf != NULL)
445 netlbl_af6list_audit_addr(audit_buf, 1,
446 dev_name,
447 addr6, mask6);
448 break;
449 }
450 #endif /* IPv6 */
451 default:
452 ret_val = -EINVAL;
453 }
454 if (ret_val == 0)
455 atomic_inc(&netlabel_mgmt_protocount);
456
457 unlhsh_add_return:
458 rcu_read_unlock();
459 if (audit_buf != NULL) {
460 if (security_secid_to_secctx(secid,
461 &secctx,
462 &secctx_len) == 0) {
463 audit_log_format(audit_buf, " sec_obj=%s", secctx);
464 security_release_secctx(secctx, secctx_len);
465 }
466 audit_log_format(audit_buf, " res=%u", ret_val == 0 ? 1 : 0);
467 audit_log_end(audit_buf);
468 }
469 return ret_val;
470 }
471
472 /**
473 * netlbl_unlhsh_remove_addr4 - Remove an IPv4 address entry
474 * @net: network namespace
475 * @iface: interface entry
476 * @addr: IP address
477 * @mask: IP address mask
478 * @audit_info: NetLabel audit information
479 *
480 * Description:
481 * Remove an IP address entry from the unlabeled connection hash table.
482 * Returns zero on success, negative values on failure.
483 *
484 */
netlbl_unlhsh_remove_addr4(struct net * net,struct netlbl_unlhsh_iface * iface,const struct in_addr * addr,const struct in_addr * mask,struct netlbl_audit * audit_info)485 static int netlbl_unlhsh_remove_addr4(struct net *net,
486 struct netlbl_unlhsh_iface *iface,
487 const struct in_addr *addr,
488 const struct in_addr *mask,
489 struct netlbl_audit *audit_info)
490 {
491 struct netlbl_af4list *list_entry;
492 struct netlbl_unlhsh_addr4 *entry;
493 struct audit_buffer *audit_buf;
494 struct net_device *dev;
495 char *secctx;
496 u32 secctx_len;
497
498 spin_lock(&netlbl_unlhsh_lock);
499 list_entry = netlbl_af4list_remove(addr->s_addr, mask->s_addr,
500 &iface->addr4_list);
501 spin_unlock(&netlbl_unlhsh_lock);
502 if (list_entry != NULL)
503 entry = netlbl_unlhsh_addr4_entry(list_entry);
504 else
505 entry = NULL;
506
507 audit_buf = netlbl_audit_start_common(AUDIT_MAC_UNLBL_STCDEL,
508 audit_info);
509 if (audit_buf != NULL) {
510 dev = dev_get_by_index(net, iface->ifindex);
511 netlbl_af4list_audit_addr(audit_buf, 1,
512 (dev != NULL ? dev->name : NULL),
513 addr->s_addr, mask->s_addr);
514 if (dev != NULL)
515 dev_put(dev);
516 if (entry != NULL &&
517 security_secid_to_secctx(entry->secid,
518 &secctx, &secctx_len) == 0) {
519 audit_log_format(audit_buf, " sec_obj=%s", secctx);
520 security_release_secctx(secctx, secctx_len);
521 }
522 audit_log_format(audit_buf, " res=%u", entry != NULL ? 1 : 0);
523 audit_log_end(audit_buf);
524 }
525
526 if (entry == NULL)
527 return -ENOENT;
528
529 kfree_rcu(entry, rcu);
530 return 0;
531 }
532
533 #if IS_ENABLED(CONFIG_IPV6)
534 /**
535 * netlbl_unlhsh_remove_addr6 - Remove an IPv6 address entry
536 * @net: network namespace
537 * @iface: interface entry
538 * @addr: IP address
539 * @mask: IP address mask
540 * @audit_info: NetLabel audit information
541 *
542 * Description:
543 * Remove an IP address entry from the unlabeled connection hash table.
544 * Returns zero on success, negative values on failure.
545 *
546 */
netlbl_unlhsh_remove_addr6(struct net * net,struct netlbl_unlhsh_iface * iface,const struct in6_addr * addr,const struct in6_addr * mask,struct netlbl_audit * audit_info)547 static int netlbl_unlhsh_remove_addr6(struct net *net,
548 struct netlbl_unlhsh_iface *iface,
549 const struct in6_addr *addr,
550 const struct in6_addr *mask,
551 struct netlbl_audit *audit_info)
552 {
553 struct netlbl_af6list *list_entry;
554 struct netlbl_unlhsh_addr6 *entry;
555 struct audit_buffer *audit_buf;
556 struct net_device *dev;
557 char *secctx;
558 u32 secctx_len;
559
560 spin_lock(&netlbl_unlhsh_lock);
561 list_entry = netlbl_af6list_remove(addr, mask, &iface->addr6_list);
562 spin_unlock(&netlbl_unlhsh_lock);
563 if (list_entry != NULL)
564 entry = netlbl_unlhsh_addr6_entry(list_entry);
565 else
566 entry = NULL;
567
568 audit_buf = netlbl_audit_start_common(AUDIT_MAC_UNLBL_STCDEL,
569 audit_info);
570 if (audit_buf != NULL) {
571 dev = dev_get_by_index(net, iface->ifindex);
572 netlbl_af6list_audit_addr(audit_buf, 1,
573 (dev != NULL ? dev->name : NULL),
574 addr, mask);
575 if (dev != NULL)
576 dev_put(dev);
577 if (entry != NULL &&
578 security_secid_to_secctx(entry->secid,
579 &secctx, &secctx_len) == 0) {
580 audit_log_format(audit_buf, " sec_obj=%s", secctx);
581 security_release_secctx(secctx, secctx_len);
582 }
583 audit_log_format(audit_buf, " res=%u", entry != NULL ? 1 : 0);
584 audit_log_end(audit_buf);
585 }
586
587 if (entry == NULL)
588 return -ENOENT;
589
590 kfree_rcu(entry, rcu);
591 return 0;
592 }
593 #endif /* IPv6 */
594
595 /**
596 * netlbl_unlhsh_condremove_iface - Remove an interface entry
597 * @iface: the interface entry
598 *
599 * Description:
600 * Remove an interface entry from the unlabeled connection hash table if it is
601 * empty. An interface entry is considered to be empty if there are no
602 * address entries assigned to it.
603 *
604 */
netlbl_unlhsh_condremove_iface(struct netlbl_unlhsh_iface * iface)605 static void netlbl_unlhsh_condremove_iface(struct netlbl_unlhsh_iface *iface)
606 {
607 struct netlbl_af4list *iter4;
608 #if IS_ENABLED(CONFIG_IPV6)
609 struct netlbl_af6list *iter6;
610 #endif /* IPv6 */
611
612 spin_lock(&netlbl_unlhsh_lock);
613 netlbl_af4list_foreach_rcu(iter4, &iface->addr4_list)
614 goto unlhsh_condremove_failure;
615 #if IS_ENABLED(CONFIG_IPV6)
616 netlbl_af6list_foreach_rcu(iter6, &iface->addr6_list)
617 goto unlhsh_condremove_failure;
618 #endif /* IPv6 */
619 iface->valid = 0;
620 if (iface->ifindex > 0)
621 list_del_rcu(&iface->list);
622 else
623 RCU_INIT_POINTER(netlbl_unlhsh_def, NULL);
624 spin_unlock(&netlbl_unlhsh_lock);
625
626 call_rcu(&iface->rcu, netlbl_unlhsh_free_iface);
627 return;
628
629 unlhsh_condremove_failure:
630 spin_unlock(&netlbl_unlhsh_lock);
631 }
632
633 /**
634 * netlbl_unlhsh_remove - Remove an entry from the unlabeled hash table
635 * @net: network namespace
636 * @dev_name: interface name
637 * @addr: IP address in network byte order
638 * @mask: address mask in network byte order
639 * @addr_len: length of address/mask (4 for IPv4, 16 for IPv6)
640 * @audit_info: NetLabel audit information
641 *
642 * Description:
643 * Removes and existing entry from the unlabeled connection hash table.
644 * Returns zero on success, negative values on failure.
645 *
646 */
netlbl_unlhsh_remove(struct net * net,const char * dev_name,const void * addr,const void * mask,u32 addr_len,struct netlbl_audit * audit_info)647 int netlbl_unlhsh_remove(struct net *net,
648 const char *dev_name,
649 const void *addr,
650 const void *mask,
651 u32 addr_len,
652 struct netlbl_audit *audit_info)
653 {
654 int ret_val;
655 struct net_device *dev;
656 struct netlbl_unlhsh_iface *iface;
657
658 if (addr_len != sizeof(struct in_addr) &&
659 addr_len != sizeof(struct in6_addr))
660 return -EINVAL;
661
662 rcu_read_lock();
663 if (dev_name != NULL) {
664 dev = dev_get_by_name_rcu(net, dev_name);
665 if (dev == NULL) {
666 ret_val = -ENODEV;
667 goto unlhsh_remove_return;
668 }
669 iface = netlbl_unlhsh_search_iface(dev->ifindex);
670 } else
671 iface = rcu_dereference(netlbl_unlhsh_def);
672 if (iface == NULL) {
673 ret_val = -ENOENT;
674 goto unlhsh_remove_return;
675 }
676 switch (addr_len) {
677 case sizeof(struct in_addr):
678 ret_val = netlbl_unlhsh_remove_addr4(net,
679 iface, addr, mask,
680 audit_info);
681 break;
682 #if IS_ENABLED(CONFIG_IPV6)
683 case sizeof(struct in6_addr):
684 ret_val = netlbl_unlhsh_remove_addr6(net,
685 iface, addr, mask,
686 audit_info);
687 break;
688 #endif /* IPv6 */
689 default:
690 ret_val = -EINVAL;
691 }
692 if (ret_val == 0) {
693 netlbl_unlhsh_condremove_iface(iface);
694 atomic_dec(&netlabel_mgmt_protocount);
695 }
696
697 unlhsh_remove_return:
698 rcu_read_unlock();
699 return ret_val;
700 }
701
702 /*
703 * General Helper Functions
704 */
705
706 /**
707 * netlbl_unlhsh_netdev_handler - Network device notification handler
708 * @this: notifier block
709 * @event: the event
710 * @ptr: the netdevice notifier info (cast to void)
711 *
712 * Description:
713 * Handle network device events, although at present all we care about is a
714 * network device going away. In the case of a device going away we clear any
715 * related entries from the unlabeled connection hash table.
716 *
717 */
netlbl_unlhsh_netdev_handler(struct notifier_block * this,unsigned long event,void * ptr)718 static int netlbl_unlhsh_netdev_handler(struct notifier_block *this,
719 unsigned long event, void *ptr)
720 {
721 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
722 struct netlbl_unlhsh_iface *iface = NULL;
723
724 if (!net_eq(dev_net(dev), &init_net))
725 return NOTIFY_DONE;
726
727 /* XXX - should this be a check for NETDEV_DOWN or _UNREGISTER? */
728 if (event == NETDEV_DOWN) {
729 spin_lock(&netlbl_unlhsh_lock);
730 iface = netlbl_unlhsh_search_iface(dev->ifindex);
731 if (iface != NULL && iface->valid) {
732 iface->valid = 0;
733 list_del_rcu(&iface->list);
734 } else
735 iface = NULL;
736 spin_unlock(&netlbl_unlhsh_lock);
737 }
738
739 if (iface != NULL)
740 call_rcu(&iface->rcu, netlbl_unlhsh_free_iface);
741
742 return NOTIFY_DONE;
743 }
744
745 /**
746 * netlbl_unlabel_acceptflg_set - Set the unlabeled accept flag
747 * @value: desired value
748 * @audit_info: NetLabel audit information
749 *
750 * Description:
751 * Set the value of the unlabeled accept flag to @value.
752 *
753 */
netlbl_unlabel_acceptflg_set(u8 value,struct netlbl_audit * audit_info)754 static void netlbl_unlabel_acceptflg_set(u8 value,
755 struct netlbl_audit *audit_info)
756 {
757 struct audit_buffer *audit_buf;
758 u8 old_val;
759
760 old_val = netlabel_unlabel_acceptflg;
761 netlabel_unlabel_acceptflg = value;
762 audit_buf = netlbl_audit_start_common(AUDIT_MAC_UNLBL_ALLOW,
763 audit_info);
764 if (audit_buf != NULL) {
765 audit_log_format(audit_buf,
766 " unlbl_accept=%u old=%u", value, old_val);
767 audit_log_end(audit_buf);
768 }
769 }
770
771 /**
772 * netlbl_unlabel_addrinfo_get - Get the IPv4/6 address information
773 * @info: the Generic NETLINK info block
774 * @addr: the IP address
775 * @mask: the IP address mask
776 * @len: the address length
777 *
778 * Description:
779 * Examine the Generic NETLINK message and extract the IP address information.
780 * Returns zero on success, negative values on failure.
781 *
782 */
netlbl_unlabel_addrinfo_get(struct genl_info * info,void ** addr,void ** mask,u32 * len)783 static int netlbl_unlabel_addrinfo_get(struct genl_info *info,
784 void **addr,
785 void **mask,
786 u32 *len)
787 {
788 u32 addr_len;
789
790 if (info->attrs[NLBL_UNLABEL_A_IPV4ADDR] &&
791 info->attrs[NLBL_UNLABEL_A_IPV4MASK]) {
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 */
netlbl_unlabel_accept(struct sk_buff * skb,struct genl_info * info)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 */
netlbl_unlabel_list(struct sk_buff * skb,struct genl_info * info)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 */
netlbl_unlabel_staticadd(struct sk_buff * skb,struct genl_info * info)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 */
netlbl_unlabel_staticadddef(struct sk_buff * skb,struct genl_info * info)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 */
netlbl_unlabel_staticremove(struct sk_buff * skb,struct genl_info * info)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 */
netlbl_unlabel_staticremovedef(struct sk_buff * skb,struct genl_info * info)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 */
netlbl_unlabel_staticlist_gen(u32 cmd,const struct netlbl_unlhsh_iface * iface,const struct netlbl_unlhsh_addr4 * addr4,const struct netlbl_unlhsh_addr6 * addr6,void * arg)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_in_addr(cb_arg->skb,
1122 NLBL_UNLABEL_A_IPV4ADDR,
1123 addr_struct.s_addr);
1124 if (ret_val != 0)
1125 goto list_cb_failure;
1126
1127 addr_struct.s_addr = addr4->list.mask;
1128 ret_val = nla_put_in_addr(cb_arg->skb,
1129 NLBL_UNLABEL_A_IPV4MASK,
1130 addr_struct.s_addr);
1131 if (ret_val != 0)
1132 goto list_cb_failure;
1133
1134 secid = addr4->secid;
1135 } else {
1136 ret_val = nla_put_in6_addr(cb_arg->skb,
1137 NLBL_UNLABEL_A_IPV6ADDR,
1138 &addr6->list.addr);
1139 if (ret_val != 0)
1140 goto list_cb_failure;
1141
1142 ret_val = nla_put_in6_addr(cb_arg->skb,
1143 NLBL_UNLABEL_A_IPV6MASK,
1144 &addr6->list.mask);
1145 if (ret_val != 0)
1146 goto list_cb_failure;
1147
1148 secid = addr6->secid;
1149 }
1150
1151 ret_val = security_secid_to_secctx(secid, &secctx, &secctx_len);
1152 if (ret_val != 0)
1153 goto list_cb_failure;
1154 ret_val = nla_put(cb_arg->skb,
1155 NLBL_UNLABEL_A_SECCTX,
1156 secctx_len,
1157 secctx);
1158 security_release_secctx(secctx, secctx_len);
1159 if (ret_val != 0)
1160 goto list_cb_failure;
1161
1162 cb_arg->seq++;
1163 genlmsg_end(cb_arg->skb, data);
1164 return 0;
1165
1166 list_cb_failure:
1167 genlmsg_cancel(cb_arg->skb, data);
1168 return ret_val;
1169 }
1170
1171 /**
1172 * netlbl_unlabel_staticlist - Handle a STATICLIST message
1173 * @skb: the NETLINK buffer
1174 * @cb: the NETLINK callback
1175 *
1176 * Description:
1177 * Process a user generated STATICLIST message and dump the unlabeled
1178 * connection hash table in a form suitable for use in a kernel generated
1179 * STATICLIST message. Returns the length of @skb.
1180 *
1181 */
netlbl_unlabel_staticlist(struct sk_buff * skb,struct netlink_callback * cb)1182 static int netlbl_unlabel_staticlist(struct sk_buff *skb,
1183 struct netlink_callback *cb)
1184 {
1185 struct netlbl_unlhsh_walk_arg cb_arg;
1186 u32 skip_bkt = cb->args[0];
1187 u32 skip_chain = cb->args[1];
1188 u32 skip_addr4 = cb->args[2];
1189 u32 iter_bkt, iter_chain = 0, iter_addr4 = 0, iter_addr6 = 0;
1190 struct netlbl_unlhsh_iface *iface;
1191 struct list_head *iter_list;
1192 struct netlbl_af4list *addr4;
1193 #if IS_ENABLED(CONFIG_IPV6)
1194 u32 skip_addr6 = cb->args[3];
1195 struct netlbl_af6list *addr6;
1196 #endif
1197
1198 cb_arg.nl_cb = cb;
1199 cb_arg.skb = skb;
1200 cb_arg.seq = cb->nlh->nlmsg_seq;
1201
1202 rcu_read_lock();
1203 for (iter_bkt = skip_bkt;
1204 iter_bkt < rcu_dereference(netlbl_unlhsh)->size;
1205 iter_bkt++) {
1206 iter_list = &rcu_dereference(netlbl_unlhsh)->tbl[iter_bkt];
1207 list_for_each_entry_rcu(iface, iter_list, list) {
1208 if (!iface->valid ||
1209 iter_chain++ < skip_chain)
1210 continue;
1211 netlbl_af4list_foreach_rcu(addr4,
1212 &iface->addr4_list) {
1213 if (iter_addr4++ < skip_addr4)
1214 continue;
1215 if (netlbl_unlabel_staticlist_gen(
1216 NLBL_UNLABEL_C_STATICLIST,
1217 iface,
1218 netlbl_unlhsh_addr4_entry(addr4),
1219 NULL,
1220 &cb_arg) < 0) {
1221 iter_addr4--;
1222 iter_chain--;
1223 goto unlabel_staticlist_return;
1224 }
1225 }
1226 iter_addr4 = 0;
1227 skip_addr4 = 0;
1228 #if IS_ENABLED(CONFIG_IPV6)
1229 netlbl_af6list_foreach_rcu(addr6,
1230 &iface->addr6_list) {
1231 if (iter_addr6++ < skip_addr6)
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 iter_addr6 = 0;
1245 skip_addr6 = 0;
1246 #endif /* IPv6 */
1247 }
1248 iter_chain = 0;
1249 skip_chain = 0;
1250 }
1251
1252 unlabel_staticlist_return:
1253 rcu_read_unlock();
1254 cb->args[0] = iter_bkt;
1255 cb->args[1] = iter_chain;
1256 cb->args[2] = iter_addr4;
1257 cb->args[3] = iter_addr6;
1258 return skb->len;
1259 }
1260
1261 /**
1262 * netlbl_unlabel_staticlistdef - Handle a STATICLISTDEF message
1263 * @skb: the NETLINK buffer
1264 * @cb: the NETLINK callback
1265 *
1266 * Description:
1267 * Process a user generated STATICLISTDEF message and dump the default
1268 * unlabeled connection entry in a form suitable for use in a kernel generated
1269 * STATICLISTDEF message. Returns the length of @skb.
1270 *
1271 */
netlbl_unlabel_staticlistdef(struct sk_buff * skb,struct netlink_callback * cb)1272 static int netlbl_unlabel_staticlistdef(struct sk_buff *skb,
1273 struct netlink_callback *cb)
1274 {
1275 struct netlbl_unlhsh_walk_arg cb_arg;
1276 struct netlbl_unlhsh_iface *iface;
1277 u32 iter_addr4 = 0, iter_addr6 = 0;
1278 struct netlbl_af4list *addr4;
1279 #if IS_ENABLED(CONFIG_IPV6)
1280 struct netlbl_af6list *addr6;
1281 #endif
1282
1283 cb_arg.nl_cb = cb;
1284 cb_arg.skb = skb;
1285 cb_arg.seq = cb->nlh->nlmsg_seq;
1286
1287 rcu_read_lock();
1288 iface = rcu_dereference(netlbl_unlhsh_def);
1289 if (iface == NULL || !iface->valid)
1290 goto unlabel_staticlistdef_return;
1291
1292 netlbl_af4list_foreach_rcu(addr4, &iface->addr4_list) {
1293 if (iter_addr4++ < cb->args[0])
1294 continue;
1295 if (netlbl_unlabel_staticlist_gen(NLBL_UNLABEL_C_STATICLISTDEF,
1296 iface,
1297 netlbl_unlhsh_addr4_entry(addr4),
1298 NULL,
1299 &cb_arg) < 0) {
1300 iter_addr4--;
1301 goto unlabel_staticlistdef_return;
1302 }
1303 }
1304 #if IS_ENABLED(CONFIG_IPV6)
1305 netlbl_af6list_foreach_rcu(addr6, &iface->addr6_list) {
1306 if (iter_addr6++ < cb->args[1])
1307 continue;
1308 if (netlbl_unlabel_staticlist_gen(NLBL_UNLABEL_C_STATICLISTDEF,
1309 iface,
1310 NULL,
1311 netlbl_unlhsh_addr6_entry(addr6),
1312 &cb_arg) < 0) {
1313 iter_addr6--;
1314 goto unlabel_staticlistdef_return;
1315 }
1316 }
1317 #endif /* IPv6 */
1318
1319 unlabel_staticlistdef_return:
1320 rcu_read_unlock();
1321 cb->args[0] = iter_addr4;
1322 cb->args[1] = iter_addr6;
1323 return skb->len;
1324 }
1325
1326 /*
1327 * NetLabel Generic NETLINK Command Definitions
1328 */
1329
1330 static const struct genl_ops netlbl_unlabel_genl_ops[] = {
1331 {
1332 .cmd = NLBL_UNLABEL_C_STATICADD,
1333 .flags = GENL_ADMIN_PERM,
1334 .policy = netlbl_unlabel_genl_policy,
1335 .doit = netlbl_unlabel_staticadd,
1336 .dumpit = NULL,
1337 },
1338 {
1339 .cmd = NLBL_UNLABEL_C_STATICREMOVE,
1340 .flags = GENL_ADMIN_PERM,
1341 .policy = netlbl_unlabel_genl_policy,
1342 .doit = netlbl_unlabel_staticremove,
1343 .dumpit = NULL,
1344 },
1345 {
1346 .cmd = NLBL_UNLABEL_C_STATICLIST,
1347 .flags = 0,
1348 .policy = netlbl_unlabel_genl_policy,
1349 .doit = NULL,
1350 .dumpit = netlbl_unlabel_staticlist,
1351 },
1352 {
1353 .cmd = NLBL_UNLABEL_C_STATICADDDEF,
1354 .flags = GENL_ADMIN_PERM,
1355 .policy = netlbl_unlabel_genl_policy,
1356 .doit = netlbl_unlabel_staticadddef,
1357 .dumpit = NULL,
1358 },
1359 {
1360 .cmd = NLBL_UNLABEL_C_STATICREMOVEDEF,
1361 .flags = GENL_ADMIN_PERM,
1362 .policy = netlbl_unlabel_genl_policy,
1363 .doit = netlbl_unlabel_staticremovedef,
1364 .dumpit = NULL,
1365 },
1366 {
1367 .cmd = NLBL_UNLABEL_C_STATICLISTDEF,
1368 .flags = 0,
1369 .policy = netlbl_unlabel_genl_policy,
1370 .doit = NULL,
1371 .dumpit = netlbl_unlabel_staticlistdef,
1372 },
1373 {
1374 .cmd = NLBL_UNLABEL_C_ACCEPT,
1375 .flags = GENL_ADMIN_PERM,
1376 .policy = netlbl_unlabel_genl_policy,
1377 .doit = netlbl_unlabel_accept,
1378 .dumpit = NULL,
1379 },
1380 {
1381 .cmd = NLBL_UNLABEL_C_LIST,
1382 .flags = 0,
1383 .policy = netlbl_unlabel_genl_policy,
1384 .doit = netlbl_unlabel_list,
1385 .dumpit = NULL,
1386 },
1387 };
1388
1389 /*
1390 * NetLabel Generic NETLINK Protocol Functions
1391 */
1392
1393 /**
1394 * netlbl_unlabel_genl_init - Register the Unlabeled NetLabel component
1395 *
1396 * Description:
1397 * Register the unlabeled packet NetLabel component with the Generic NETLINK
1398 * mechanism. Returns zero on success, negative values on failure.
1399 *
1400 */
netlbl_unlabel_genl_init(void)1401 int __init netlbl_unlabel_genl_init(void)
1402 {
1403 return genl_register_family_with_ops(&netlbl_unlabel_gnl_family,
1404 netlbl_unlabel_genl_ops);
1405 }
1406
1407 /*
1408 * NetLabel KAPI Hooks
1409 */
1410
1411 static struct notifier_block netlbl_unlhsh_netdev_notifier = {
1412 .notifier_call = netlbl_unlhsh_netdev_handler,
1413 };
1414
1415 /**
1416 * netlbl_unlabel_init - Initialize the unlabeled connection hash table
1417 * @size: the number of bits to use for the hash buckets
1418 *
1419 * Description:
1420 * Initializes the unlabeled connection hash table and registers a network
1421 * device notification handler. This function should only be called by the
1422 * NetLabel subsystem itself during initialization. Returns zero on success,
1423 * non-zero values on error.
1424 *
1425 */
netlbl_unlabel_init(u32 size)1426 int __init netlbl_unlabel_init(u32 size)
1427 {
1428 u32 iter;
1429 struct netlbl_unlhsh_tbl *hsh_tbl;
1430
1431 if (size == 0)
1432 return -EINVAL;
1433
1434 hsh_tbl = kmalloc(sizeof(*hsh_tbl), GFP_KERNEL);
1435 if (hsh_tbl == NULL)
1436 return -ENOMEM;
1437 hsh_tbl->size = 1 << size;
1438 hsh_tbl->tbl = kcalloc(hsh_tbl->size,
1439 sizeof(struct list_head),
1440 GFP_KERNEL);
1441 if (hsh_tbl->tbl == NULL) {
1442 kfree(hsh_tbl);
1443 return -ENOMEM;
1444 }
1445 for (iter = 0; iter < hsh_tbl->size; iter++)
1446 INIT_LIST_HEAD(&hsh_tbl->tbl[iter]);
1447
1448 spin_lock(&netlbl_unlhsh_lock);
1449 rcu_assign_pointer(netlbl_unlhsh, hsh_tbl);
1450 spin_unlock(&netlbl_unlhsh_lock);
1451
1452 register_netdevice_notifier(&netlbl_unlhsh_netdev_notifier);
1453
1454 return 0;
1455 }
1456
1457 /**
1458 * netlbl_unlabel_getattr - Get the security attributes for an unlabled packet
1459 * @skb: the packet
1460 * @family: protocol family
1461 * @secattr: the security attributes
1462 *
1463 * Description:
1464 * Determine the security attributes, if any, for an unlabled packet and return
1465 * them in @secattr. Returns zero on success and negative values on failure.
1466 *
1467 */
netlbl_unlabel_getattr(const struct sk_buff * skb,u16 family,struct netlbl_lsm_secattr * secattr)1468 int netlbl_unlabel_getattr(const struct sk_buff *skb,
1469 u16 family,
1470 struct netlbl_lsm_secattr *secattr)
1471 {
1472 struct netlbl_unlhsh_iface *iface;
1473
1474 rcu_read_lock();
1475 iface = netlbl_unlhsh_search_iface(skb->skb_iif);
1476 if (iface == NULL)
1477 iface = rcu_dereference(netlbl_unlhsh_def);
1478 if (iface == NULL || !iface->valid)
1479 goto unlabel_getattr_nolabel;
1480
1481 #if IS_ENABLED(CONFIG_IPV6)
1482 /* When resolving a fallback label, check the sk_buff version as
1483 * it is possible (e.g. SCTP) to have family = PF_INET6 while
1484 * receiving ip_hdr(skb)->version = 4.
1485 */
1486 if (family == PF_INET6 && ip_hdr(skb)->version == 4)
1487 family = PF_INET;
1488 #endif /* IPv6 */
1489
1490 switch (family) {
1491 case PF_INET: {
1492 struct iphdr *hdr4;
1493 struct netlbl_af4list *addr4;
1494
1495 hdr4 = ip_hdr(skb);
1496 addr4 = netlbl_af4list_search(hdr4->saddr,
1497 &iface->addr4_list);
1498 if (addr4 == NULL)
1499 goto unlabel_getattr_nolabel;
1500 secattr->attr.secid = netlbl_unlhsh_addr4_entry(addr4)->secid;
1501 break;
1502 }
1503 #if IS_ENABLED(CONFIG_IPV6)
1504 case PF_INET6: {
1505 struct ipv6hdr *hdr6;
1506 struct netlbl_af6list *addr6;
1507
1508 hdr6 = ipv6_hdr(skb);
1509 addr6 = netlbl_af6list_search(&hdr6->saddr,
1510 &iface->addr6_list);
1511 if (addr6 == NULL)
1512 goto unlabel_getattr_nolabel;
1513 secattr->attr.secid = netlbl_unlhsh_addr6_entry(addr6)->secid;
1514 break;
1515 }
1516 #endif /* IPv6 */
1517 default:
1518 goto unlabel_getattr_nolabel;
1519 }
1520 rcu_read_unlock();
1521
1522 secattr->flags |= NETLBL_SECATTR_SECID;
1523 secattr->type = NETLBL_NLTYPE_UNLABELED;
1524 return 0;
1525
1526 unlabel_getattr_nolabel:
1527 rcu_read_unlock();
1528 if (netlabel_unlabel_acceptflg == 0)
1529 return -ENOMSG;
1530 secattr->type = NETLBL_NLTYPE_UNLABELED;
1531 return 0;
1532 }
1533
1534 /**
1535 * netlbl_unlabel_defconf - Set the default config to allow unlabeled packets
1536 *
1537 * Description:
1538 * Set the default NetLabel configuration to allow incoming unlabeled packets
1539 * and to send unlabeled network traffic by default.
1540 *
1541 */
netlbl_unlabel_defconf(void)1542 int __init netlbl_unlabel_defconf(void)
1543 {
1544 int ret_val;
1545 struct netlbl_dom_map *entry;
1546 struct netlbl_audit audit_info;
1547
1548 /* Only the kernel is allowed to call this function and the only time
1549 * it is called is at bootup before the audit subsystem is reporting
1550 * messages so don't worry to much about these values. */
1551 security_task_getsecid(current, &audit_info.secid);
1552 audit_info.loginuid = GLOBAL_ROOT_UID;
1553 audit_info.sessionid = 0;
1554
1555 entry = kzalloc(sizeof(*entry), GFP_KERNEL);
1556 if (entry == NULL)
1557 return -ENOMEM;
1558 entry->def.type = NETLBL_NLTYPE_UNLABELED;
1559 ret_val = netlbl_domhsh_add_default(entry, &audit_info);
1560 if (ret_val != 0)
1561 return ret_val;
1562
1563 netlbl_unlabel_acceptflg_set(1, &audit_info);
1564
1565 return 0;
1566 }
1567