2 * Copyright 2002-2005, Instant802 Networks, Inc.
3 * Copyright 2005-2006, Devicescape Software, Inc.
4 * Copyright 2006-2007 Jiri Benc <jbenc@suse.cz>
5 * Copyright 2007-2008 Johannes Berg <johannes@sipsolutions.net>
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
12 #include <linux/if_ether.h>
13 #include <linux/etherdevice.h>
14 #include <linux/list.h>
15 #include <linux/rcupdate.h>
16 #include <linux/rtnetlink.h>
17 #include <linux/slab.h>
18 #include <linux/export.h>
19 #include <net/mac80211.h>
20 #include "ieee80211_i.h"
21 #include "driver-ops.h"
22 #include "debugfs_key.h"
28 * DOC: Key handling basics
30 * Key handling in mac80211 is done based on per-interface (sub_if_data)
31 * keys and per-station keys. Since each station belongs to an interface,
32 * each station key also belongs to that interface.
34 * Hardware acceleration is done on a best-effort basis for algorithms
35 * that are implemented in software, for each key the hardware is asked
36 * to enable that key for offloading but if it cannot do that the key is
37 * simply kept for software encryption (unless it is for an algorithm
38 * that isn't implemented in software).
39 * There is currently no way of knowing whether a key is handled in SW
40 * or HW except by looking into debugfs.
42 * All key management is internally protected by a mutex. Within all
43 * other parts of mac80211, key references are, just as STA structure
44 * references, protected by RCU. Note, however, that some things are
45 * unprotected, namely the key->sta dereferences within the hardware
46 * acceleration functions. This means that sta_info_destroy() must
47 * remove the key which waits for an RCU grace period.
50 static const u8 bcast_addr
[ETH_ALEN
] = { 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF };
52 static void assert_key_lock(struct ieee80211_local
*local
)
54 lockdep_assert_held(&local
->key_mtx
);
57 static struct ieee80211_sta
*get_sta_for_key(struct ieee80211_key
*key
)
60 return &key
->sta
->sta
;
65 static void increment_tailroom_need_count(struct ieee80211_sub_if_data
*sdata
)
68 * When this count is zero, SKB resizing for allocating tailroom
69 * for IV or MMIC is skipped. But, this check has created two race
70 * cases in xmit path while transiting from zero count to one:
72 * 1. SKB resize was skipped because no key was added but just before
73 * the xmit key is added and SW encryption kicks off.
75 * 2. SKB resize was skipped because all the keys were hw planted but
76 * just before xmit one of the key is deleted and SW encryption kicks
79 * In both the above case SW encryption will find not enough space for
80 * tailroom and exits with WARN_ON. (See WARN_ONs at wpa.c)
82 * Solution has been explained at
83 * http://mid.gmane.org/1308590980.4322.19.camel@jlt3.sipsolutions.net
86 if (!sdata
->crypto_tx_tailroom_needed_cnt
++) {
88 * Flush all XMIT packets currently using HW encryption or no
89 * encryption at all if the count transition is from 0 -> 1.
95 static int ieee80211_key_enable_hw_accel(struct ieee80211_key
*key
)
97 struct ieee80211_sub_if_data
*sdata
;
98 struct ieee80211_sta
*sta
;
103 if (!key
->local
->ops
->set_key
)
104 goto out_unsupported
;
106 assert_key_lock(key
->local
);
108 sta
= get_sta_for_key(key
);
111 * If this is a per-STA GTK, check if it
112 * is supported; if not, return.
114 if (sta
&& !(key
->conf
.flags
& IEEE80211_KEY_FLAG_PAIRWISE
) &&
115 !(key
->local
->hw
.flags
& IEEE80211_HW_SUPPORTS_PER_STA_GTK
))
116 goto out_unsupported
;
119 if (sdata
->vif
.type
== NL80211_IFTYPE_AP_VLAN
) {
121 * The driver doesn't know anything about VLAN interfaces.
122 * Hence, don't send GTKs for VLAN interfaces to the driver.
124 if (!(key
->conf
.flags
& IEEE80211_KEY_FLAG_PAIRWISE
))
125 goto out_unsupported
;
126 sdata
= container_of(sdata
->bss
,
127 struct ieee80211_sub_if_data
,
131 ret
= drv_set_key(key
->local
, SET_KEY
, sdata
, sta
, &key
->conf
);
134 key
->flags
|= KEY_FLAG_UPLOADED_TO_HARDWARE
;
136 if (!((key
->conf
.flags
& IEEE80211_KEY_FLAG_GENERATE_MMIC
) ||
137 (key
->conf
.flags
& IEEE80211_KEY_FLAG_GENERATE_IV
) ||
138 (key
->conf
.flags
& IEEE80211_KEY_FLAG_PUT_IV_SPACE
)))
139 sdata
->crypto_tx_tailroom_needed_cnt
--;
141 WARN_ON((key
->conf
.flags
& IEEE80211_KEY_FLAG_PUT_IV_SPACE
) &&
142 (key
->conf
.flags
& IEEE80211_KEY_FLAG_GENERATE_IV
));
147 if (ret
!= -ENOSPC
&& ret
!= -EOPNOTSUPP
)
148 wiphy_err(key
->local
->hw
.wiphy
,
149 "failed to set key (%d, %pM) to hardware (%d)\n",
150 key
->conf
.keyidx
, sta
? sta
->addr
: bcast_addr
, ret
);
153 switch (key
->conf
.cipher
) {
154 case WLAN_CIPHER_SUITE_WEP40
:
155 case WLAN_CIPHER_SUITE_WEP104
:
156 case WLAN_CIPHER_SUITE_TKIP
:
157 case WLAN_CIPHER_SUITE_CCMP
:
158 case WLAN_CIPHER_SUITE_AES_CMAC
:
159 /* all of these we can do in software */
166 static void ieee80211_key_disable_hw_accel(struct ieee80211_key
*key
)
168 struct ieee80211_sub_if_data
*sdata
;
169 struct ieee80211_sta
*sta
;
174 if (!key
|| !key
->local
->ops
->set_key
)
177 assert_key_lock(key
->local
);
179 if (!(key
->flags
& KEY_FLAG_UPLOADED_TO_HARDWARE
))
182 sta
= get_sta_for_key(key
);
185 if (!((key
->conf
.flags
& IEEE80211_KEY_FLAG_GENERATE_MMIC
) ||
186 (key
->conf
.flags
& IEEE80211_KEY_FLAG_GENERATE_IV
) ||
187 (key
->conf
.flags
& IEEE80211_KEY_FLAG_PUT_IV_SPACE
)))
188 increment_tailroom_need_count(sdata
);
190 if (sdata
->vif
.type
== NL80211_IFTYPE_AP_VLAN
)
191 sdata
= container_of(sdata
->bss
,
192 struct ieee80211_sub_if_data
,
195 ret
= drv_set_key(key
->local
, DISABLE_KEY
, sdata
,
199 wiphy_err(key
->local
->hw
.wiphy
,
200 "failed to remove key (%d, %pM) from hardware (%d)\n",
201 key
->conf
.keyidx
, sta
? sta
->addr
: bcast_addr
, ret
);
203 key
->flags
&= ~KEY_FLAG_UPLOADED_TO_HARDWARE
;
206 void ieee80211_key_removed(struct ieee80211_key_conf
*key_conf
)
208 struct ieee80211_key
*key
;
210 key
= container_of(key_conf
, struct ieee80211_key
, conf
);
213 assert_key_lock(key
->local
);
215 key
->flags
&= ~KEY_FLAG_UPLOADED_TO_HARDWARE
;
218 * Flush TX path to avoid attempts to use this key
219 * after this function returns. Until then, drivers
220 * must be prepared to handle the key.
224 EXPORT_SYMBOL_GPL(ieee80211_key_removed
);
226 static void __ieee80211_set_default_key(struct ieee80211_sub_if_data
*sdata
,
227 int idx
, bool uni
, bool multi
)
229 struct ieee80211_key
*key
= NULL
;
231 assert_key_lock(sdata
->local
);
233 if (idx
>= 0 && idx
< NUM_DEFAULT_KEYS
)
234 key
= key_mtx_dereference(sdata
->local
, sdata
->keys
[idx
]);
237 rcu_assign_pointer(sdata
->default_unicast_key
, key
);
239 rcu_assign_pointer(sdata
->default_multicast_key
, key
);
241 ieee80211_debugfs_key_update_default(sdata
);
244 void ieee80211_set_default_key(struct ieee80211_sub_if_data
*sdata
, int idx
,
245 bool uni
, bool multi
)
247 mutex_lock(&sdata
->local
->key_mtx
);
248 __ieee80211_set_default_key(sdata
, idx
, uni
, multi
);
249 mutex_unlock(&sdata
->local
->key_mtx
);
253 __ieee80211_set_default_mgmt_key(struct ieee80211_sub_if_data
*sdata
, int idx
)
255 struct ieee80211_key
*key
= NULL
;
257 assert_key_lock(sdata
->local
);
259 if (idx
>= NUM_DEFAULT_KEYS
&&
260 idx
< NUM_DEFAULT_KEYS
+ NUM_DEFAULT_MGMT_KEYS
)
261 key
= key_mtx_dereference(sdata
->local
, sdata
->keys
[idx
]);
263 rcu_assign_pointer(sdata
->default_mgmt_key
, key
);
265 ieee80211_debugfs_key_update_default(sdata
);
268 void ieee80211_set_default_mgmt_key(struct ieee80211_sub_if_data
*sdata
,
271 mutex_lock(&sdata
->local
->key_mtx
);
272 __ieee80211_set_default_mgmt_key(sdata
, idx
);
273 mutex_unlock(&sdata
->local
->key_mtx
);
277 static void __ieee80211_key_replace(struct ieee80211_sub_if_data
*sdata
,
278 struct sta_info
*sta
,
280 struct ieee80211_key
*old
,
281 struct ieee80211_key
*new)
284 bool defunikey
, defmultikey
, defmgmtkey
;
287 list_add_tail(&new->list
, &sdata
->key_list
);
289 if (sta
&& pairwise
) {
290 rcu_assign_pointer(sta
->ptk
, new);
293 idx
= old
->conf
.keyidx
;
295 idx
= new->conf
.keyidx
;
296 rcu_assign_pointer(sta
->gtk
[idx
], new);
298 WARN_ON(new && old
&& new->conf
.keyidx
!= old
->conf
.keyidx
);
301 idx
= old
->conf
.keyidx
;
303 idx
= new->conf
.keyidx
;
306 old
== key_mtx_dereference(sdata
->local
,
307 sdata
->default_unicast_key
);
309 old
== key_mtx_dereference(sdata
->local
,
310 sdata
->default_multicast_key
);
312 old
== key_mtx_dereference(sdata
->local
,
313 sdata
->default_mgmt_key
);
315 if (defunikey
&& !new)
316 __ieee80211_set_default_key(sdata
, -1, true, false);
317 if (defmultikey
&& !new)
318 __ieee80211_set_default_key(sdata
, -1, false, true);
319 if (defmgmtkey
&& !new)
320 __ieee80211_set_default_mgmt_key(sdata
, -1);
322 rcu_assign_pointer(sdata
->keys
[idx
], new);
323 if (defunikey
&& new)
324 __ieee80211_set_default_key(sdata
, new->conf
.keyidx
,
326 if (defmultikey
&& new)
327 __ieee80211_set_default_key(sdata
, new->conf
.keyidx
,
329 if (defmgmtkey
&& new)
330 __ieee80211_set_default_mgmt_key(sdata
,
335 list_del(&old
->list
);
338 struct ieee80211_key
*ieee80211_key_alloc(u32 cipher
, int idx
, size_t key_len
,
340 size_t seq_len
, const u8
*seq
)
342 struct ieee80211_key
*key
;
345 BUG_ON(idx
< 0 || idx
>= NUM_DEFAULT_KEYS
+ NUM_DEFAULT_MGMT_KEYS
);
347 key
= kzalloc(sizeof(struct ieee80211_key
) + key_len
, GFP_KERNEL
);
349 return ERR_PTR(-ENOMEM
);
352 * Default to software encryption; we'll later upload the
353 * key to the hardware if possible.
358 key
->conf
.cipher
= cipher
;
359 key
->conf
.keyidx
= idx
;
360 key
->conf
.keylen
= key_len
;
362 case WLAN_CIPHER_SUITE_WEP40
:
363 case WLAN_CIPHER_SUITE_WEP104
:
364 key
->conf
.iv_len
= WEP_IV_LEN
;
365 key
->conf
.icv_len
= WEP_ICV_LEN
;
367 case WLAN_CIPHER_SUITE_TKIP
:
368 key
->conf
.iv_len
= TKIP_IV_LEN
;
369 key
->conf
.icv_len
= TKIP_ICV_LEN
;
371 for (i
= 0; i
< NUM_RX_DATA_QUEUES
; i
++) {
372 key
->u
.tkip
.rx
[i
].iv32
=
373 get_unaligned_le32(&seq
[2]);
374 key
->u
.tkip
.rx
[i
].iv16
=
375 get_unaligned_le16(seq
);
378 spin_lock_init(&key
->u
.tkip
.txlock
);
380 case WLAN_CIPHER_SUITE_CCMP
:
381 key
->conf
.iv_len
= CCMP_HDR_LEN
;
382 key
->conf
.icv_len
= CCMP_MIC_LEN
;
384 for (i
= 0; i
< NUM_RX_DATA_QUEUES
+ 1; i
++)
385 for (j
= 0; j
< CCMP_PN_LEN
; j
++)
386 key
->u
.ccmp
.rx_pn
[i
][j
] =
387 seq
[CCMP_PN_LEN
- j
- 1];
390 * Initialize AES key state here as an optimization so that
391 * it does not need to be initialized for every packet.
393 key
->u
.ccmp
.tfm
= ieee80211_aes_key_setup_encrypt(key_data
);
394 if (IS_ERR(key
->u
.ccmp
.tfm
)) {
395 err
= PTR_ERR(key
->u
.ccmp
.tfm
);
400 case WLAN_CIPHER_SUITE_AES_CMAC
:
401 key
->conf
.iv_len
= 0;
402 key
->conf
.icv_len
= sizeof(struct ieee80211_mmie
);
404 for (j
= 0; j
< 6; j
++)
405 key
->u
.aes_cmac
.rx_pn
[j
] = seq
[6 - j
- 1];
407 * Initialize AES key state here as an optimization so that
408 * it does not need to be initialized for every packet.
410 key
->u
.aes_cmac
.tfm
=
411 ieee80211_aes_cmac_key_setup(key_data
);
412 if (IS_ERR(key
->u
.aes_cmac
.tfm
)) {
413 err
= PTR_ERR(key
->u
.aes_cmac
.tfm
);
419 memcpy(key
->conf
.key
, key_data
, key_len
);
420 INIT_LIST_HEAD(&key
->list
);
425 static void __ieee80211_key_destroy(struct ieee80211_key
*key
)
431 * Synchronize so the TX path can no longer be using
432 * this key before we free/remove it.
437 ieee80211_key_disable_hw_accel(key
);
439 if (key
->conf
.cipher
== WLAN_CIPHER_SUITE_CCMP
)
440 ieee80211_aes_key_free(key
->u
.ccmp
.tfm
);
441 if (key
->conf
.cipher
== WLAN_CIPHER_SUITE_AES_CMAC
)
442 ieee80211_aes_cmac_key_free(key
->u
.aes_cmac
.tfm
);
444 ieee80211_debugfs_key_remove(key
);
445 key
->sdata
->crypto_tx_tailroom_needed_cnt
--;
451 int ieee80211_key_link(struct ieee80211_key
*key
,
452 struct ieee80211_sub_if_data
*sdata
,
453 struct sta_info
*sta
)
455 struct ieee80211_key
*old_key
;
462 pairwise
= key
->conf
.flags
& IEEE80211_KEY_FLAG_PAIRWISE
;
463 idx
= key
->conf
.keyidx
;
464 key
->local
= sdata
->local
;
470 * some hardware cannot handle TKIP with QoS, so
471 * we indicate whether QoS could be in use.
473 if (test_sta_flag(sta
, WLAN_STA_WME
))
474 key
->conf
.flags
|= IEEE80211_KEY_FLAG_WMM_STA
;
476 if (sdata
->vif
.type
== NL80211_IFTYPE_STATION
) {
480 * We're getting a sta pointer in, so must be under
481 * appropriate locking for sta_info_get().
484 /* same here, the AP could be using QoS */
485 ap
= sta_info_get(key
->sdata
, key
->sdata
->u
.mgd
.bssid
);
487 if (test_sta_flag(ap
, WLAN_STA_WME
))
489 IEEE80211_KEY_FLAG_WMM_STA
;
494 mutex_lock(&sdata
->local
->key_mtx
);
497 old_key
= key_mtx_dereference(sdata
->local
, sta
->ptk
);
499 old_key
= key_mtx_dereference(sdata
->local
, sta
->gtk
[idx
]);
501 old_key
= key_mtx_dereference(sdata
->local
, sdata
->keys
[idx
]);
503 increment_tailroom_need_count(sdata
);
505 __ieee80211_key_replace(sdata
, sta
, pairwise
, old_key
, key
);
506 __ieee80211_key_destroy(old_key
);
508 ieee80211_debugfs_key_add(key
);
510 ret
= ieee80211_key_enable_hw_accel(key
);
512 mutex_unlock(&sdata
->local
->key_mtx
);
517 void __ieee80211_key_free(struct ieee80211_key
*key
)
523 * Replace key with nothingness if it was ever used.
526 __ieee80211_key_replace(key
->sdata
, key
->sta
,
527 key
->conf
.flags
& IEEE80211_KEY_FLAG_PAIRWISE
,
529 __ieee80211_key_destroy(key
);
532 void ieee80211_key_free(struct ieee80211_local
*local
,
533 struct ieee80211_key
*key
)
535 mutex_lock(&local
->key_mtx
);
536 __ieee80211_key_free(key
);
537 mutex_unlock(&local
->key_mtx
);
540 void ieee80211_enable_keys(struct ieee80211_sub_if_data
*sdata
)
542 struct ieee80211_key
*key
;
546 if (WARN_ON(!ieee80211_sdata_running(sdata
)))
549 mutex_lock(&sdata
->local
->key_mtx
);
551 sdata
->crypto_tx_tailroom_needed_cnt
= 0;
553 list_for_each_entry(key
, &sdata
->key_list
, list
) {
554 increment_tailroom_need_count(sdata
);
555 ieee80211_key_enable_hw_accel(key
);
558 mutex_unlock(&sdata
->local
->key_mtx
);
561 void ieee80211_iter_keys(struct ieee80211_hw
*hw
,
562 struct ieee80211_vif
*vif
,
563 void (*iter
)(struct ieee80211_hw
*hw
,
564 struct ieee80211_vif
*vif
,
565 struct ieee80211_sta
*sta
,
566 struct ieee80211_key_conf
*key
,
570 struct ieee80211_local
*local
= hw_to_local(hw
);
571 struct ieee80211_key
*key
;
572 struct ieee80211_sub_if_data
*sdata
;
576 mutex_lock(&local
->key_mtx
);
578 sdata
= vif_to_sdata(vif
);
579 list_for_each_entry(key
, &sdata
->key_list
, list
)
580 iter(hw
, &sdata
->vif
,
581 key
->sta
? &key
->sta
->sta
: NULL
,
582 &key
->conf
, iter_data
);
584 list_for_each_entry(sdata
, &local
->interfaces
, list
)
585 list_for_each_entry(key
, &sdata
->key_list
, list
)
586 iter(hw
, &sdata
->vif
,
587 key
->sta
? &key
->sta
->sta
: NULL
,
588 &key
->conf
, iter_data
);
590 mutex_unlock(&local
->key_mtx
);
592 EXPORT_SYMBOL(ieee80211_iter_keys
);
594 void ieee80211_disable_keys(struct ieee80211_sub_if_data
*sdata
)
596 struct ieee80211_key
*key
;
600 mutex_lock(&sdata
->local
->key_mtx
);
602 list_for_each_entry(key
, &sdata
->key_list
, list
)
603 ieee80211_key_disable_hw_accel(key
);
605 mutex_unlock(&sdata
->local
->key_mtx
);
608 void ieee80211_free_keys(struct ieee80211_sub_if_data
*sdata
)
610 struct ieee80211_key
*key
, *tmp
;
612 mutex_lock(&sdata
->local
->key_mtx
);
614 ieee80211_debugfs_key_remove_mgmt_default(sdata
);
616 list_for_each_entry_safe(key
, tmp
, &sdata
->key_list
, list
)
617 __ieee80211_key_free(key
);
619 ieee80211_debugfs_key_update_default(sdata
);
621 mutex_unlock(&sdata
->local
->key_mtx
);
625 void ieee80211_gtk_rekey_notify(struct ieee80211_vif
*vif
, const u8
*bssid
,
626 const u8
*replay_ctr
, gfp_t gfp
)
628 struct ieee80211_sub_if_data
*sdata
= vif_to_sdata(vif
);
630 trace_api_gtk_rekey_notify(sdata
, bssid
, replay_ctr
);
632 cfg80211_gtk_rekey_notify(sdata
->dev
, bssid
, replay_ctr
, gfp
);
634 EXPORT_SYMBOL_GPL(ieee80211_gtk_rekey_notify
);
636 void ieee80211_get_key_tx_seq(struct ieee80211_key_conf
*keyconf
,
637 struct ieee80211_key_seq
*seq
)
639 struct ieee80211_key
*key
;
642 if (WARN_ON(!(keyconf
->flags
& IEEE80211_KEY_FLAG_GENERATE_IV
)))
645 key
= container_of(keyconf
, struct ieee80211_key
, conf
);
647 switch (key
->conf
.cipher
) {
648 case WLAN_CIPHER_SUITE_TKIP
:
649 seq
->tkip
.iv32
= key
->u
.tkip
.tx
.iv32
;
650 seq
->tkip
.iv16
= key
->u
.tkip
.tx
.iv16
;
652 case WLAN_CIPHER_SUITE_CCMP
:
653 pn64
= atomic64_read(&key
->u
.ccmp
.tx_pn
);
654 seq
->ccmp
.pn
[5] = pn64
;
655 seq
->ccmp
.pn
[4] = pn64
>> 8;
656 seq
->ccmp
.pn
[3] = pn64
>> 16;
657 seq
->ccmp
.pn
[2] = pn64
>> 24;
658 seq
->ccmp
.pn
[1] = pn64
>> 32;
659 seq
->ccmp
.pn
[0] = pn64
>> 40;
661 case WLAN_CIPHER_SUITE_AES_CMAC
:
662 pn64
= atomic64_read(&key
->u
.aes_cmac
.tx_pn
);
663 seq
->ccmp
.pn
[5] = pn64
;
664 seq
->ccmp
.pn
[4] = pn64
>> 8;
665 seq
->ccmp
.pn
[3] = pn64
>> 16;
666 seq
->ccmp
.pn
[2] = pn64
>> 24;
667 seq
->ccmp
.pn
[1] = pn64
>> 32;
668 seq
->ccmp
.pn
[0] = pn64
>> 40;
674 EXPORT_SYMBOL(ieee80211_get_key_tx_seq
);
676 void ieee80211_get_key_rx_seq(struct ieee80211_key_conf
*keyconf
,
677 int tid
, struct ieee80211_key_seq
*seq
)
679 struct ieee80211_key
*key
;
682 key
= container_of(keyconf
, struct ieee80211_key
, conf
);
684 switch (key
->conf
.cipher
) {
685 case WLAN_CIPHER_SUITE_TKIP
:
686 if (WARN_ON(tid
< 0 || tid
>= NUM_RX_DATA_QUEUES
))
688 seq
->tkip
.iv32
= key
->u
.tkip
.rx
[tid
].iv32
;
689 seq
->tkip
.iv16
= key
->u
.tkip
.rx
[tid
].iv16
;
691 case WLAN_CIPHER_SUITE_CCMP
:
692 if (WARN_ON(tid
< -1 || tid
>= NUM_RX_DATA_QUEUES
))
695 pn
= key
->u
.ccmp
.rx_pn
[NUM_RX_DATA_QUEUES
];
697 pn
= key
->u
.ccmp
.rx_pn
[tid
];
698 memcpy(seq
->ccmp
.pn
, pn
, CCMP_PN_LEN
);
700 case WLAN_CIPHER_SUITE_AES_CMAC
:
701 if (WARN_ON(tid
!= 0))
703 pn
= key
->u
.aes_cmac
.rx_pn
;
704 memcpy(seq
->aes_cmac
.pn
, pn
, CMAC_PN_LEN
);
708 EXPORT_SYMBOL(ieee80211_get_key_rx_seq
);