2 * NetLabel Domain Hash Table
4 * This file manages the domain hash table that NetLabel uses to determine
5 * which network labeling protocol to use for a given domain. The NetLabel
6 * system manages static and dynamic label mappings for network protocols such
9 * Author: Paul Moore <paul.moore@hp.com>
14 * (c) Copyright Hewlett-Packard Development Company, L.P., 2006, 2008
16 * This program is free software; you can redistribute it and/or modify
17 * it under the terms of the GNU General Public License as published by
18 * the Free Software Foundation; either version 2 of the License, or
19 * (at your option) any later version.
21 * This program is distributed in the hope that it will be useful,
22 * but WITHOUT ANY WARRANTY; without even the implied warranty of
23 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
24 * the GNU General Public License for more details.
26 * You should have received a copy of the GNU General Public License
27 * along with this program; if not, write to the Free Software
28 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
32 #include <linux/types.h>
33 #include <linux/rculist.h>
34 #include <linux/skbuff.h>
35 #include <linux/spinlock.h>
36 #include <linux/string.h>
37 #include <linux/audit.h>
38 #include <linux/slab.h>
39 #include <net/netlabel.h>
40 #include <net/cipso_ipv4.h>
43 #include "netlabel_mgmt.h"
44 #include "netlabel_addrlist.h"
45 #include "netlabel_domainhash.h"
46 #include "netlabel_user.h"
48 struct netlbl_domhsh_tbl
{
49 struct list_head
*tbl
;
53 /* Domain hash table */
54 /* updates should be so rare that having one spinlock for the entire hash table
56 static DEFINE_SPINLOCK(netlbl_domhsh_lock
);
57 #define netlbl_domhsh_rcu_deref(p) \
58 rcu_dereference_check(p, rcu_read_lock_held() || \
59 lockdep_is_held(&netlbl_domhsh_lock))
60 static struct netlbl_domhsh_tbl
*netlbl_domhsh
= NULL
;
61 static struct netlbl_dom_map
*netlbl_domhsh_def
= NULL
;
64 * Domain Hash Table Helper Functions
68 * netlbl_domhsh_free_entry - Frees a domain hash table entry
69 * @entry: the entry's RCU field
72 * This function is designed to be used as a callback to the call_rcu()
73 * function so that the memory allocated to a hash table entry can be released
77 static void netlbl_domhsh_free_entry(struct rcu_head
*entry
)
79 struct netlbl_dom_map
*ptr
;
80 struct netlbl_af4list
*iter4
;
81 struct netlbl_af4list
*tmp4
;
82 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
83 struct netlbl_af6list
*iter6
;
84 struct netlbl_af6list
*tmp6
;
87 ptr
= container_of(entry
, struct netlbl_dom_map
, rcu
);
88 if (ptr
->type
== NETLBL_NLTYPE_ADDRSELECT
) {
89 netlbl_af4list_foreach_safe(iter4
, tmp4
,
90 &ptr
->type_def
.addrsel
->list4
) {
91 netlbl_af4list_remove_entry(iter4
);
92 kfree(netlbl_domhsh_addr4_entry(iter4
));
94 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
95 netlbl_af6list_foreach_safe(iter6
, tmp6
,
96 &ptr
->type_def
.addrsel
->list6
) {
97 netlbl_af6list_remove_entry(iter6
);
98 kfree(netlbl_domhsh_addr6_entry(iter6
));
107 * netlbl_domhsh_hash - Hashing function for the domain hash table
108 * @domain: the domain name to hash
111 * This is the hashing function for the domain hash table, it returns the
112 * correct bucket number for the domain. The caller is responsibile for
113 * ensuring that the hash table is protected with either a RCU read lock or the
117 static u32
netlbl_domhsh_hash(const char *key
)
123 /* This is taken (with slight modification) from
124 * security/selinux/ss/symtab.c:symhash() */
126 for (iter
= 0, val
= 0, len
= strlen(key
); iter
< len
; iter
++)
127 val
= (val
<< 4 | (val
>> (8 * sizeof(u32
) - 4))) ^ key
[iter
];
128 return val
& (netlbl_domhsh_rcu_deref(netlbl_domhsh
)->size
- 1);
132 * netlbl_domhsh_search - Search for a domain entry
133 * @domain: the domain
136 * Searches the domain hash table and returns a pointer to the hash table
137 * entry if found, otherwise NULL is returned. The caller is responsibile for
138 * ensuring that the hash table is protected with either a RCU read lock or the
142 static struct netlbl_dom_map
*netlbl_domhsh_search(const char *domain
)
145 struct list_head
*bkt_list
;
146 struct netlbl_dom_map
*iter
;
148 if (domain
!= NULL
) {
149 bkt
= netlbl_domhsh_hash(domain
);
150 bkt_list
= &netlbl_domhsh_rcu_deref(netlbl_domhsh
)->tbl
[bkt
];
151 list_for_each_entry_rcu(iter
, bkt_list
, list
)
152 if (iter
->valid
&& strcmp(iter
->domain
, domain
) == 0)
160 * netlbl_domhsh_search_def - Search for a domain entry
161 * @domain: the domain
162 * @def: return default if no match is found
165 * Searches the domain hash table and returns a pointer to the hash table
166 * entry if an exact match is found, if an exact match is not present in the
167 * hash table then the default entry is returned if valid otherwise NULL is
168 * returned. The caller is responsibile ensuring that the hash table is
169 * protected with either a RCU read lock or the hash table lock.
172 static struct netlbl_dom_map
*netlbl_domhsh_search_def(const char *domain
)
174 struct netlbl_dom_map
*entry
;
176 entry
= netlbl_domhsh_search(domain
);
178 entry
= netlbl_domhsh_rcu_deref(netlbl_domhsh_def
);
179 if (entry
!= NULL
&& !entry
->valid
)
187 * netlbl_domhsh_audit_add - Generate an audit entry for an add event
188 * @entry: the entry being added
189 * @addr4: the IPv4 address information
190 * @addr6: the IPv6 address information
191 * @result: the result code
192 * @audit_info: NetLabel audit information
195 * Generate an audit record for adding a new NetLabel/LSM mapping entry with
196 * the given information. Caller is responsibile for holding the necessary
200 static void netlbl_domhsh_audit_add(struct netlbl_dom_map
*entry
,
201 struct netlbl_af4list
*addr4
,
202 struct netlbl_af6list
*addr6
,
204 struct netlbl_audit
*audit_info
)
206 struct audit_buffer
*audit_buf
;
207 struct cipso_v4_doi
*cipsov4
= NULL
;
210 audit_buf
= netlbl_audit_start_common(AUDIT_MAC_MAP_ADD
, audit_info
);
211 if (audit_buf
!= NULL
) {
212 audit_log_format(audit_buf
, " nlbl_domain=%s",
213 entry
->domain
? entry
->domain
: "(default)");
215 struct netlbl_domaddr4_map
*map4
;
216 map4
= netlbl_domhsh_addr4_entry(addr4
);
218 cipsov4
= map4
->type_def
.cipsov4
;
219 netlbl_af4list_audit_addr(audit_buf
, 0, NULL
,
220 addr4
->addr
, addr4
->mask
);
221 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
222 } else if (addr6
!= NULL
) {
223 struct netlbl_domaddr6_map
*map6
;
224 map6
= netlbl_domhsh_addr6_entry(addr6
);
226 netlbl_af6list_audit_addr(audit_buf
, 0, NULL
,
227 &addr6
->addr
, &addr6
->mask
);
231 cipsov4
= entry
->type_def
.cipsov4
;
234 case NETLBL_NLTYPE_UNLABELED
:
235 audit_log_format(audit_buf
, " nlbl_protocol=unlbl");
237 case NETLBL_NLTYPE_CIPSOV4
:
238 BUG_ON(cipsov4
== NULL
);
239 audit_log_format(audit_buf
,
240 " nlbl_protocol=cipsov4 cipso_doi=%u",
244 audit_log_format(audit_buf
, " res=%u", result
== 0 ? 1 : 0);
245 audit_log_end(audit_buf
);
250 * Domain Hash Table Functions
254 * netlbl_domhsh_init - Init for the domain hash
255 * @size: the number of bits to use for the hash buckets
258 * Initializes the domain hash table, should be called only by
259 * netlbl_user_init() during initialization. Returns zero on success, non-zero
263 int __init
netlbl_domhsh_init(u32 size
)
266 struct netlbl_domhsh_tbl
*hsh_tbl
;
271 hsh_tbl
= kmalloc(sizeof(*hsh_tbl
), GFP_KERNEL
);
274 hsh_tbl
->size
= 1 << size
;
275 hsh_tbl
->tbl
= kcalloc(hsh_tbl
->size
,
276 sizeof(struct list_head
),
278 if (hsh_tbl
->tbl
== NULL
) {
282 for (iter
= 0; iter
< hsh_tbl
->size
; iter
++)
283 INIT_LIST_HEAD(&hsh_tbl
->tbl
[iter
]);
285 spin_lock(&netlbl_domhsh_lock
);
286 rcu_assign_pointer(netlbl_domhsh
, hsh_tbl
);
287 spin_unlock(&netlbl_domhsh_lock
);
293 * netlbl_domhsh_add - Adds a entry to the domain hash table
294 * @entry: the entry to add
295 * @audit_info: NetLabel audit information
298 * Adds a new entry to the domain hash table and handles any updates to the
299 * lower level protocol handler (i.e. CIPSO). Returns zero on success,
300 * negative on failure.
303 int netlbl_domhsh_add(struct netlbl_dom_map
*entry
,
304 struct netlbl_audit
*audit_info
)
307 struct netlbl_dom_map
*entry_old
;
308 struct netlbl_af4list
*iter4
;
309 struct netlbl_af4list
*tmp4
;
310 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
311 struct netlbl_af6list
*iter6
;
312 struct netlbl_af6list
*tmp6
;
316 spin_lock(&netlbl_domhsh_lock
);
317 if (entry
->domain
!= NULL
)
318 entry_old
= netlbl_domhsh_search(entry
->domain
);
320 entry_old
= netlbl_domhsh_search_def(entry
->domain
);
321 if (entry_old
== NULL
) {
324 if (entry
->domain
!= NULL
) {
325 u32 bkt
= netlbl_domhsh_hash(entry
->domain
);
326 list_add_tail_rcu(&entry
->list
,
327 &rcu_dereference(netlbl_domhsh
)->tbl
[bkt
]);
329 INIT_LIST_HEAD(&entry
->list
);
330 rcu_assign_pointer(netlbl_domhsh_def
, entry
);
333 if (entry
->type
== NETLBL_NLTYPE_ADDRSELECT
) {
334 netlbl_af4list_foreach_rcu(iter4
,
335 &entry
->type_def
.addrsel
->list4
)
336 netlbl_domhsh_audit_add(entry
, iter4
, NULL
,
337 ret_val
, audit_info
);
338 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
339 netlbl_af6list_foreach_rcu(iter6
,
340 &entry
->type_def
.addrsel
->list6
)
341 netlbl_domhsh_audit_add(entry
, NULL
, iter6
,
342 ret_val
, audit_info
);
345 netlbl_domhsh_audit_add(entry
, NULL
, NULL
,
346 ret_val
, audit_info
);
347 } else if (entry_old
->type
== NETLBL_NLTYPE_ADDRSELECT
&&
348 entry
->type
== NETLBL_NLTYPE_ADDRSELECT
) {
349 struct list_head
*old_list4
;
350 struct list_head
*old_list6
;
352 old_list4
= &entry_old
->type_def
.addrsel
->list4
;
353 old_list6
= &entry_old
->type_def
.addrsel
->list6
;
355 /* we only allow the addition of address selectors if all of
356 * the selectors do not exist in the existing domain map */
357 netlbl_af4list_foreach_rcu(iter4
,
358 &entry
->type_def
.addrsel
->list4
)
359 if (netlbl_af4list_search_exact(iter4
->addr
,
365 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
366 netlbl_af6list_foreach_rcu(iter6
,
367 &entry
->type_def
.addrsel
->list6
)
368 if (netlbl_af6list_search_exact(&iter6
->addr
,
376 netlbl_af4list_foreach_safe(iter4
, tmp4
,
377 &entry
->type_def
.addrsel
->list4
) {
378 netlbl_af4list_remove_entry(iter4
);
380 ret_val
= netlbl_af4list_add(iter4
, old_list4
);
381 netlbl_domhsh_audit_add(entry_old
, iter4
, NULL
,
382 ret_val
, audit_info
);
386 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
387 netlbl_af6list_foreach_safe(iter6
, tmp6
,
388 &entry
->type_def
.addrsel
->list6
) {
389 netlbl_af6list_remove_entry(iter6
);
391 ret_val
= netlbl_af6list_add(iter6
, old_list6
);
392 netlbl_domhsh_audit_add(entry_old
, NULL
, iter6
,
393 ret_val
, audit_info
);
402 spin_unlock(&netlbl_domhsh_lock
);
408 * netlbl_domhsh_add_default - Adds the default entry to the domain hash table
409 * @entry: the entry to add
410 * @audit_info: NetLabel audit information
413 * Adds a new default entry to the domain hash table and handles any updates
414 * to the lower level protocol handler (i.e. CIPSO). Returns zero on success,
415 * negative on failure.
418 int netlbl_domhsh_add_default(struct netlbl_dom_map
*entry
,
419 struct netlbl_audit
*audit_info
)
421 return netlbl_domhsh_add(entry
, audit_info
);
425 * netlbl_domhsh_remove_entry - Removes a given entry from the domain table
426 * @entry: the entry to remove
427 * @audit_info: NetLabel audit information
430 * Removes an entry from the domain hash table and handles any updates to the
431 * lower level protocol handler (i.e. CIPSO). Caller is responsible for
432 * ensuring that the RCU read lock is held. Returns zero on success, negative
436 int netlbl_domhsh_remove_entry(struct netlbl_dom_map
*entry
,
437 struct netlbl_audit
*audit_info
)
440 struct audit_buffer
*audit_buf
;
445 spin_lock(&netlbl_domhsh_lock
);
448 if (entry
!= rcu_dereference(netlbl_domhsh_def
))
449 list_del_rcu(&entry
->list
);
451 rcu_assign_pointer(netlbl_domhsh_def
, NULL
);
454 spin_unlock(&netlbl_domhsh_lock
);
456 audit_buf
= netlbl_audit_start_common(AUDIT_MAC_MAP_DEL
, audit_info
);
457 if (audit_buf
!= NULL
) {
458 audit_log_format(audit_buf
,
459 " nlbl_domain=%s res=%u",
460 entry
->domain
? entry
->domain
: "(default)",
461 ret_val
== 0 ? 1 : 0);
462 audit_log_end(audit_buf
);
466 struct netlbl_af4list
*iter4
;
467 struct netlbl_domaddr4_map
*map4
;
469 switch (entry
->type
) {
470 case NETLBL_NLTYPE_ADDRSELECT
:
471 netlbl_af4list_foreach_rcu(iter4
,
472 &entry
->type_def
.addrsel
->list4
) {
473 map4
= netlbl_domhsh_addr4_entry(iter4
);
474 cipso_v4_doi_putdef(map4
->type_def
.cipsov4
);
476 /* no need to check the IPv6 list since we currently
477 * support only unlabeled protocols for IPv6 */
479 case NETLBL_NLTYPE_CIPSOV4
:
480 cipso_v4_doi_putdef(entry
->type_def
.cipsov4
);
483 call_rcu(&entry
->rcu
, netlbl_domhsh_free_entry
);
490 * netlbl_domhsh_remove_af4 - Removes an address selector entry
491 * @domain: the domain
492 * @addr: IPv4 address
493 * @mask: IPv4 address mask
494 * @audit_info: NetLabel audit information
497 * Removes an individual address selector from a domain mapping and potentially
498 * the entire mapping if it is empty. Returns zero on success, negative values
502 int netlbl_domhsh_remove_af4(const char *domain
,
503 const struct in_addr
*addr
,
504 const struct in_addr
*mask
,
505 struct netlbl_audit
*audit_info
)
507 struct netlbl_dom_map
*entry_map
;
508 struct netlbl_af4list
*entry_addr
;
509 struct netlbl_af4list
*iter4
;
510 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
511 struct netlbl_af6list
*iter6
;
513 struct netlbl_domaddr4_map
*entry
;
518 entry_map
= netlbl_domhsh_search(domain
);
520 entry_map
= netlbl_domhsh_search_def(domain
);
521 if (entry_map
== NULL
|| entry_map
->type
!= NETLBL_NLTYPE_ADDRSELECT
)
522 goto remove_af4_failure
;
524 spin_lock(&netlbl_domhsh_lock
);
525 entry_addr
= netlbl_af4list_remove(addr
->s_addr
, mask
->s_addr
,
526 &entry_map
->type_def
.addrsel
->list4
);
527 spin_unlock(&netlbl_domhsh_lock
);
529 if (entry_addr
== NULL
)
530 goto remove_af4_failure
;
531 netlbl_af4list_foreach_rcu(iter4
, &entry_map
->type_def
.addrsel
->list4
)
532 goto remove_af4_single_addr
;
533 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
534 netlbl_af6list_foreach_rcu(iter6
, &entry_map
->type_def
.addrsel
->list6
)
535 goto remove_af4_single_addr
;
537 /* the domain mapping is empty so remove it from the mapping table */
538 netlbl_domhsh_remove_entry(entry_map
, audit_info
);
540 remove_af4_single_addr
:
542 /* yick, we can't use call_rcu here because we don't have a rcu head
543 * pointer but hopefully this should be a rare case so the pause
544 * shouldn't be a problem */
546 entry
= netlbl_domhsh_addr4_entry(entry_addr
);
547 cipso_v4_doi_putdef(entry
->type_def
.cipsov4
);
557 * netlbl_domhsh_remove - Removes an entry from the domain hash table
558 * @domain: the domain to remove
559 * @audit_info: NetLabel audit information
562 * Removes an entry from the domain hash table and handles any updates to the
563 * lower level protocol handler (i.e. CIPSO). Returns zero on success,
564 * negative on failure.
567 int netlbl_domhsh_remove(const char *domain
, struct netlbl_audit
*audit_info
)
570 struct netlbl_dom_map
*entry
;
574 entry
= netlbl_domhsh_search(domain
);
576 entry
= netlbl_domhsh_search_def(domain
);
577 ret_val
= netlbl_domhsh_remove_entry(entry
, audit_info
);
584 * netlbl_domhsh_remove_default - Removes the default entry from the table
585 * @audit_info: NetLabel audit information
588 * Removes/resets the default entry for the domain hash table and handles any
589 * updates to the lower level protocol handler (i.e. CIPSO). Returns zero on
590 * success, non-zero on failure.
593 int netlbl_domhsh_remove_default(struct netlbl_audit
*audit_info
)
595 return netlbl_domhsh_remove(NULL
, audit_info
);
599 * netlbl_domhsh_getentry - Get an entry from the domain hash table
600 * @domain: the domain name to search for
603 * Look through the domain hash table searching for an entry to match @domain,
604 * return a pointer to a copy of the entry or NULL. The caller is responsibile
605 * for ensuring that rcu_read_[un]lock() is called.
608 struct netlbl_dom_map
*netlbl_domhsh_getentry(const char *domain
)
610 return netlbl_domhsh_search_def(domain
);
614 * netlbl_domhsh_getentry_af4 - Get an entry from the domain hash table
615 * @domain: the domain name to search for
616 * @addr: the IP address to search for
619 * Look through the domain hash table searching for an entry to match @domain
620 * and @addr, return a pointer to a copy of the entry or NULL. The caller is
621 * responsible for ensuring that rcu_read_[un]lock() is called.
624 struct netlbl_domaddr4_map
*netlbl_domhsh_getentry_af4(const char *domain
,
627 struct netlbl_dom_map
*dom_iter
;
628 struct netlbl_af4list
*addr_iter
;
630 dom_iter
= netlbl_domhsh_search_def(domain
);
631 if (dom_iter
== NULL
)
633 if (dom_iter
->type
!= NETLBL_NLTYPE_ADDRSELECT
)
636 addr_iter
= netlbl_af4list_search(addr
,
637 &dom_iter
->type_def
.addrsel
->list4
);
638 if (addr_iter
== NULL
)
641 return netlbl_domhsh_addr4_entry(addr_iter
);
644 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
646 * netlbl_domhsh_getentry_af6 - Get an entry from the domain hash table
647 * @domain: the domain name to search for
648 * @addr: the IP address to search for
651 * Look through the domain hash table searching for an entry to match @domain
652 * and @addr, return a pointer to a copy of the entry or NULL. The caller is
653 * responsible for ensuring that rcu_read_[un]lock() is called.
656 struct netlbl_domaddr6_map
*netlbl_domhsh_getentry_af6(const char *domain
,
657 const struct in6_addr
*addr
)
659 struct netlbl_dom_map
*dom_iter
;
660 struct netlbl_af6list
*addr_iter
;
662 dom_iter
= netlbl_domhsh_search_def(domain
);
663 if (dom_iter
== NULL
)
665 if (dom_iter
->type
!= NETLBL_NLTYPE_ADDRSELECT
)
668 addr_iter
= netlbl_af6list_search(addr
,
669 &dom_iter
->type_def
.addrsel
->list6
);
670 if (addr_iter
== NULL
)
673 return netlbl_domhsh_addr6_entry(addr_iter
);
678 * netlbl_domhsh_walk - Iterate through the domain mapping hash table
679 * @skip_bkt: the number of buckets to skip at the start
680 * @skip_chain: the number of entries to skip in the first iterated bucket
681 * @callback: callback for each entry
682 * @cb_arg: argument for the callback function
685 * Interate over the domain mapping hash table, skipping the first @skip_bkt
686 * buckets and @skip_chain entries. For each entry in the table call
687 * @callback, if @callback returns a negative value stop 'walking' through the
688 * table and return. Updates the values in @skip_bkt and @skip_chain on
689 * return. Returns zero on success, negative values on failure.
692 int netlbl_domhsh_walk(u32
*skip_bkt
,
694 int (*callback
) (struct netlbl_dom_map
*entry
, void *arg
),
697 int ret_val
= -ENOENT
;
699 struct list_head
*iter_list
;
700 struct netlbl_dom_map
*iter_entry
;
704 for (iter_bkt
= *skip_bkt
;
705 iter_bkt
< rcu_dereference(netlbl_domhsh
)->size
;
706 iter_bkt
++, chain_cnt
= 0) {
707 iter_list
= &rcu_dereference(netlbl_domhsh
)->tbl
[iter_bkt
];
708 list_for_each_entry_rcu(iter_entry
, iter_list
, list
)
709 if (iter_entry
->valid
) {
710 if (chain_cnt
++ < *skip_chain
)
712 ret_val
= callback(iter_entry
, cb_arg
);
722 *skip_bkt
= iter_bkt
;
723 *skip_chain
= chain_cnt
;