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TOMOYO Linux Cross Reference
Linux/net/mac80211/key.c

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  1 /*
  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>
  6  * Copyright 2013-2014  Intel Mobile Communications GmbH
  7  * Copyright 2015       Intel Deutschland GmbH
  8  *
  9  * This program is free software; you can redistribute it and/or modify
 10  * it under the terms of the GNU General Public License version 2 as
 11  * published by the Free Software Foundation.
 12  */
 13 
 14 #include <linux/if_ether.h>
 15 #include <linux/etherdevice.h>
 16 #include <linux/list.h>
 17 #include <linux/rcupdate.h>
 18 #include <linux/rtnetlink.h>
 19 #include <linux/slab.h>
 20 #include <linux/export.h>
 21 #include <net/mac80211.h>
 22 #include <asm/unaligned.h>
 23 #include "ieee80211_i.h"
 24 #include "driver-ops.h"
 25 #include "debugfs_key.h"
 26 #include "aes_ccm.h"
 27 #include "aes_cmac.h"
 28 #include "aes_gmac.h"
 29 #include "aes_gcm.h"
 30 
 31 
 32 /**
 33  * DOC: Key handling basics
 34  *
 35  * Key handling in mac80211 is done based on per-interface (sub_if_data)
 36  * keys and per-station keys. Since each station belongs to an interface,
 37  * each station key also belongs to that interface.
 38  *
 39  * Hardware acceleration is done on a best-effort basis for algorithms
 40  * that are implemented in software,  for each key the hardware is asked
 41  * to enable that key for offloading but if it cannot do that the key is
 42  * simply kept for software encryption (unless it is for an algorithm
 43  * that isn't implemented in software).
 44  * There is currently no way of knowing whether a key is handled in SW
 45  * or HW except by looking into debugfs.
 46  *
 47  * All key management is internally protected by a mutex. Within all
 48  * other parts of mac80211, key references are, just as STA structure
 49  * references, protected by RCU. Note, however, that some things are
 50  * unprotected, namely the key->sta dereferences within the hardware
 51  * acceleration functions. This means that sta_info_destroy() must
 52  * remove the key which waits for an RCU grace period.
 53  */
 54 
 55 static const u8 bcast_addr[ETH_ALEN] = { 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF };
 56 
 57 static void assert_key_lock(struct ieee80211_local *local)
 58 {
 59         lockdep_assert_held(&local->key_mtx);
 60 }
 61 
 62 static void
 63 update_vlan_tailroom_need_count(struct ieee80211_sub_if_data *sdata, int delta)
 64 {
 65         struct ieee80211_sub_if_data *vlan;
 66 
 67         if (sdata->vif.type != NL80211_IFTYPE_AP)
 68                 return;
 69 
 70         /* crypto_tx_tailroom_needed_cnt is protected by this */
 71         assert_key_lock(sdata->local);
 72 
 73         rcu_read_lock();
 74 
 75         list_for_each_entry_rcu(vlan, &sdata->u.ap.vlans, u.vlan.list)
 76                 vlan->crypto_tx_tailroom_needed_cnt += delta;
 77 
 78         rcu_read_unlock();
 79 }
 80 
 81 static void increment_tailroom_need_count(struct ieee80211_sub_if_data *sdata)
 82 {
 83         /*
 84          * When this count is zero, SKB resizing for allocating tailroom
 85          * for IV or MMIC is skipped. But, this check has created two race
 86          * cases in xmit path while transiting from zero count to one:
 87          *
 88          * 1. SKB resize was skipped because no key was added but just before
 89          * the xmit key is added and SW encryption kicks off.
 90          *
 91          * 2. SKB resize was skipped because all the keys were hw planted but
 92          * just before xmit one of the key is deleted and SW encryption kicks
 93          * off.
 94          *
 95          * In both the above case SW encryption will find not enough space for
 96          * tailroom and exits with WARN_ON. (See WARN_ONs at wpa.c)
 97          *
 98          * Solution has been explained at
 99          * http://mid.gmane.org/1308590980.4322.19.camel@jlt3.sipsolutions.net
100          */
101 
102         assert_key_lock(sdata->local);
103 
104         update_vlan_tailroom_need_count(sdata, 1);
105 
106         if (!sdata->crypto_tx_tailroom_needed_cnt++) {
107                 /*
108                  * Flush all XMIT packets currently using HW encryption or no
109                  * encryption at all if the count transition is from 0 -> 1.
110                  */
111                 synchronize_net();
112         }
113 }
114 
115 static void decrease_tailroom_need_count(struct ieee80211_sub_if_data *sdata,
116                                          int delta)
117 {
118         assert_key_lock(sdata->local);
119 
120         WARN_ON_ONCE(sdata->crypto_tx_tailroom_needed_cnt < delta);
121 
122         update_vlan_tailroom_need_count(sdata, -delta);
123         sdata->crypto_tx_tailroom_needed_cnt -= delta;
124 }
125 
126 static int ieee80211_key_enable_hw_accel(struct ieee80211_key *key)
127 {
128         struct ieee80211_sub_if_data *sdata;
129         struct sta_info *sta;
130         int ret = -EOPNOTSUPP;
131 
132         might_sleep();
133 
134         if (key->flags & KEY_FLAG_TAINTED) {
135                 /* If we get here, it's during resume and the key is
136                  * tainted so shouldn't be used/programmed any more.
137                  * However, its flags may still indicate that it was
138                  * programmed into the device (since we're in resume)
139                  * so clear that flag now to avoid trying to remove
140                  * it again later.
141                  */
142                 key->flags &= ~KEY_FLAG_UPLOADED_TO_HARDWARE;
143                 return -EINVAL;
144         }
145 
146         if (!key->local->ops->set_key)
147                 goto out_unsupported;
148 
149         assert_key_lock(key->local);
150 
151         sta = key->sta;
152 
153         /*
154          * If this is a per-STA GTK, check if it
155          * is supported; if not, return.
156          */
157         if (sta && !(key->conf.flags & IEEE80211_KEY_FLAG_PAIRWISE) &&
158             !ieee80211_hw_check(&key->local->hw, SUPPORTS_PER_STA_GTK))
159                 goto out_unsupported;
160 
161         if (sta && !sta->uploaded)
162                 goto out_unsupported;
163 
164         sdata = key->sdata;
165         if (sdata->vif.type == NL80211_IFTYPE_AP_VLAN) {
166                 /*
167                  * The driver doesn't know anything about VLAN interfaces.
168                  * Hence, don't send GTKs for VLAN interfaces to the driver.
169                  */
170                 if (!(key->conf.flags & IEEE80211_KEY_FLAG_PAIRWISE))
171                         goto out_unsupported;
172         }
173 
174         ret = drv_set_key(key->local, SET_KEY, sdata,
175                           sta ? &sta->sta : NULL, &key->conf);
176 
177         if (!ret) {
178                 key->flags |= KEY_FLAG_UPLOADED_TO_HARDWARE;
179 
180                 if (!((key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_MMIC) ||
181                       (key->conf.flags & IEEE80211_KEY_FLAG_RESERVE_TAILROOM)))
182                         decrease_tailroom_need_count(sdata, 1);
183 
184                 WARN_ON((key->conf.flags & IEEE80211_KEY_FLAG_PUT_IV_SPACE) &&
185                         (key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_IV));
186 
187                 return 0;
188         }
189 
190         if (ret != -ENOSPC && ret != -EOPNOTSUPP && ret != 1)
191                 sdata_err(sdata,
192                           "failed to set key (%d, %pM) to hardware (%d)\n",
193                           key->conf.keyidx,
194                           sta ? sta->sta.addr : bcast_addr, ret);
195 
196  out_unsupported:
197         switch (key->conf.cipher) {
198         case WLAN_CIPHER_SUITE_WEP40:
199         case WLAN_CIPHER_SUITE_WEP104:
200         case WLAN_CIPHER_SUITE_TKIP:
201         case WLAN_CIPHER_SUITE_CCMP:
202         case WLAN_CIPHER_SUITE_CCMP_256:
203         case WLAN_CIPHER_SUITE_AES_CMAC:
204         case WLAN_CIPHER_SUITE_BIP_CMAC_256:
205         case WLAN_CIPHER_SUITE_BIP_GMAC_128:
206         case WLAN_CIPHER_SUITE_BIP_GMAC_256:
207         case WLAN_CIPHER_SUITE_GCMP:
208         case WLAN_CIPHER_SUITE_GCMP_256:
209                 /* all of these we can do in software - if driver can */
210                 if (ret == 1)
211                         return 0;
212                 if (ieee80211_hw_check(&key->local->hw, SW_CRYPTO_CONTROL))
213                         return -EINVAL;
214                 return 0;
215         default:
216                 return -EINVAL;
217         }
218 }
219 
220 static void ieee80211_key_disable_hw_accel(struct ieee80211_key *key)
221 {
222         struct ieee80211_sub_if_data *sdata;
223         struct sta_info *sta;
224         int ret;
225 
226         might_sleep();
227 
228         if (!key || !key->local->ops->set_key)
229                 return;
230 
231         assert_key_lock(key->local);
232 
233         if (!(key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE))
234                 return;
235 
236         sta = key->sta;
237         sdata = key->sdata;
238 
239         if (!((key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_MMIC) ||
240               (key->conf.flags & IEEE80211_KEY_FLAG_RESERVE_TAILROOM)))
241                 increment_tailroom_need_count(sdata);
242 
243         ret = drv_set_key(key->local, DISABLE_KEY, sdata,
244                           sta ? &sta->sta : NULL, &key->conf);
245 
246         if (ret)
247                 sdata_err(sdata,
248                           "failed to remove key (%d, %pM) from hardware (%d)\n",
249                           key->conf.keyidx,
250                           sta ? sta->sta.addr : bcast_addr, ret);
251 
252         key->flags &= ~KEY_FLAG_UPLOADED_TO_HARDWARE;
253 }
254 
255 static void __ieee80211_set_default_key(struct ieee80211_sub_if_data *sdata,
256                                         int idx, bool uni, bool multi)
257 {
258         struct ieee80211_key *key = NULL;
259 
260         assert_key_lock(sdata->local);
261 
262         if (idx >= 0 && idx < NUM_DEFAULT_KEYS)
263                 key = key_mtx_dereference(sdata->local, sdata->keys[idx]);
264 
265         if (uni) {
266                 rcu_assign_pointer(sdata->default_unicast_key, key);
267                 ieee80211_check_fast_xmit_iface(sdata);
268                 drv_set_default_unicast_key(sdata->local, sdata, idx);
269         }
270 
271         if (multi)
272                 rcu_assign_pointer(sdata->default_multicast_key, key);
273 
274         ieee80211_debugfs_key_update_default(sdata);
275 }
276 
277 void ieee80211_set_default_key(struct ieee80211_sub_if_data *sdata, int idx,
278                                bool uni, bool multi)
279 {
280         mutex_lock(&sdata->local->key_mtx);
281         __ieee80211_set_default_key(sdata, idx, uni, multi);
282         mutex_unlock(&sdata->local->key_mtx);
283 }
284 
285 static void
286 __ieee80211_set_default_mgmt_key(struct ieee80211_sub_if_data *sdata, int idx)
287 {
288         struct ieee80211_key *key = NULL;
289 
290         assert_key_lock(sdata->local);
291 
292         if (idx >= NUM_DEFAULT_KEYS &&
293             idx < NUM_DEFAULT_KEYS + NUM_DEFAULT_MGMT_KEYS)
294                 key = key_mtx_dereference(sdata->local, sdata->keys[idx]);
295 
296         rcu_assign_pointer(sdata->default_mgmt_key, key);
297 
298         ieee80211_debugfs_key_update_default(sdata);
299 }
300 
301 void ieee80211_set_default_mgmt_key(struct ieee80211_sub_if_data *sdata,
302                                     int idx)
303 {
304         mutex_lock(&sdata->local->key_mtx);
305         __ieee80211_set_default_mgmt_key(sdata, idx);
306         mutex_unlock(&sdata->local->key_mtx);
307 }
308 
309 
310 static void ieee80211_key_replace(struct ieee80211_sub_if_data *sdata,
311                                   struct sta_info *sta,
312                                   bool pairwise,
313                                   struct ieee80211_key *old,
314                                   struct ieee80211_key *new)
315 {
316         int idx;
317         bool defunikey, defmultikey, defmgmtkey;
318 
319         /* caller must provide at least one old/new */
320         if (WARN_ON(!new && !old))
321                 return;
322 
323         if (new)
324                 list_add_tail_rcu(&new->list, &sdata->key_list);
325 
326         WARN_ON(new && old && new->conf.keyidx != old->conf.keyidx);
327 
328         if (old)
329                 idx = old->conf.keyidx;
330         else
331                 idx = new->conf.keyidx;
332 
333         if (sta) {
334                 if (pairwise) {
335                         rcu_assign_pointer(sta->ptk[idx], new);
336                         sta->ptk_idx = idx;
337                         ieee80211_check_fast_xmit(sta);
338                 } else {
339                         rcu_assign_pointer(sta->gtk[idx], new);
340                 }
341                 ieee80211_check_fast_rx(sta);
342         } else {
343                 defunikey = old &&
344                         old == key_mtx_dereference(sdata->local,
345                                                 sdata->default_unicast_key);
346                 defmultikey = old &&
347                         old == key_mtx_dereference(sdata->local,
348                                                 sdata->default_multicast_key);
349                 defmgmtkey = old &&
350                         old == key_mtx_dereference(sdata->local,
351                                                 sdata->default_mgmt_key);
352 
353                 if (defunikey && !new)
354                         __ieee80211_set_default_key(sdata, -1, true, false);
355                 if (defmultikey && !new)
356                         __ieee80211_set_default_key(sdata, -1, false, true);
357                 if (defmgmtkey && !new)
358                         __ieee80211_set_default_mgmt_key(sdata, -1);
359 
360                 rcu_assign_pointer(sdata->keys[idx], new);
361                 if (defunikey && new)
362                         __ieee80211_set_default_key(sdata, new->conf.keyidx,
363                                                     true, false);
364                 if (defmultikey && new)
365                         __ieee80211_set_default_key(sdata, new->conf.keyidx,
366                                                     false, true);
367                 if (defmgmtkey && new)
368                         __ieee80211_set_default_mgmt_key(sdata,
369                                                          new->conf.keyidx);
370         }
371 
372         if (old)
373                 list_del_rcu(&old->list);
374 }
375 
376 struct ieee80211_key *
377 ieee80211_key_alloc(u32 cipher, int idx, size_t key_len,
378                     const u8 *key_data,
379                     size_t seq_len, const u8 *seq,
380                     const struct ieee80211_cipher_scheme *cs)
381 {
382         struct ieee80211_key *key;
383         int i, j, err;
384 
385         if (WARN_ON(idx < 0 || idx >= NUM_DEFAULT_KEYS + NUM_DEFAULT_MGMT_KEYS))
386                 return ERR_PTR(-EINVAL);
387 
388         key = kzalloc(sizeof(struct ieee80211_key) + key_len, GFP_KERNEL);
389         if (!key)
390                 return ERR_PTR(-ENOMEM);
391 
392         /*
393          * Default to software encryption; we'll later upload the
394          * key to the hardware if possible.
395          */
396         key->conf.flags = 0;
397         key->flags = 0;
398 
399         key->conf.cipher = cipher;
400         key->conf.keyidx = idx;
401         key->conf.keylen = key_len;
402         switch (cipher) {
403         case WLAN_CIPHER_SUITE_WEP40:
404         case WLAN_CIPHER_SUITE_WEP104:
405                 key->conf.iv_len = IEEE80211_WEP_IV_LEN;
406                 key->conf.icv_len = IEEE80211_WEP_ICV_LEN;
407                 break;
408         case WLAN_CIPHER_SUITE_TKIP:
409                 key->conf.iv_len = IEEE80211_TKIP_IV_LEN;
410                 key->conf.icv_len = IEEE80211_TKIP_ICV_LEN;
411                 if (seq) {
412                         for (i = 0; i < IEEE80211_NUM_TIDS; i++) {
413                                 key->u.tkip.rx[i].iv32 =
414                                         get_unaligned_le32(&seq[2]);
415                                 key->u.tkip.rx[i].iv16 =
416                                         get_unaligned_le16(seq);
417                         }
418                 }
419                 spin_lock_init(&key->u.tkip.txlock);
420                 break;
421         case WLAN_CIPHER_SUITE_CCMP:
422                 key->conf.iv_len = IEEE80211_CCMP_HDR_LEN;
423                 key->conf.icv_len = IEEE80211_CCMP_MIC_LEN;
424                 if (seq) {
425                         for (i = 0; i < IEEE80211_NUM_TIDS + 1; i++)
426                                 for (j = 0; j < IEEE80211_CCMP_PN_LEN; j++)
427                                         key->u.ccmp.rx_pn[i][j] =
428                                                 seq[IEEE80211_CCMP_PN_LEN - j - 1];
429                 }
430                 /*
431                  * Initialize AES key state here as an optimization so that
432                  * it does not need to be initialized for every packet.
433                  */
434                 key->u.ccmp.tfm = ieee80211_aes_key_setup_encrypt(
435                         key_data, key_len, IEEE80211_CCMP_MIC_LEN);
436                 if (IS_ERR(key->u.ccmp.tfm)) {
437                         err = PTR_ERR(key->u.ccmp.tfm);
438                         kfree(key);
439                         return ERR_PTR(err);
440                 }
441                 break;
442         case WLAN_CIPHER_SUITE_CCMP_256:
443                 key->conf.iv_len = IEEE80211_CCMP_256_HDR_LEN;
444                 key->conf.icv_len = IEEE80211_CCMP_256_MIC_LEN;
445                 for (i = 0; seq && i < IEEE80211_NUM_TIDS + 1; i++)
446                         for (j = 0; j < IEEE80211_CCMP_256_PN_LEN; j++)
447                                 key->u.ccmp.rx_pn[i][j] =
448                                         seq[IEEE80211_CCMP_256_PN_LEN - j - 1];
449                 /* Initialize AES key state here as an optimization so that
450                  * it does not need to be initialized for every packet.
451                  */
452                 key->u.ccmp.tfm = ieee80211_aes_key_setup_encrypt(
453                         key_data, key_len, IEEE80211_CCMP_256_MIC_LEN);
454                 if (IS_ERR(key->u.ccmp.tfm)) {
455                         err = PTR_ERR(key->u.ccmp.tfm);
456                         kfree(key);
457                         return ERR_PTR(err);
458                 }
459                 break;
460         case WLAN_CIPHER_SUITE_AES_CMAC:
461         case WLAN_CIPHER_SUITE_BIP_CMAC_256:
462                 key->conf.iv_len = 0;
463                 if (cipher == WLAN_CIPHER_SUITE_AES_CMAC)
464                         key->conf.icv_len = sizeof(struct ieee80211_mmie);
465                 else
466                         key->conf.icv_len = sizeof(struct ieee80211_mmie_16);
467                 if (seq)
468                         for (j = 0; j < IEEE80211_CMAC_PN_LEN; j++)
469                                 key->u.aes_cmac.rx_pn[j] =
470                                         seq[IEEE80211_CMAC_PN_LEN - j - 1];
471                 /*
472                  * Initialize AES key state here as an optimization so that
473                  * it does not need to be initialized for every packet.
474                  */
475                 key->u.aes_cmac.tfm =
476                         ieee80211_aes_cmac_key_setup(key_data, key_len);
477                 if (IS_ERR(key->u.aes_cmac.tfm)) {
478                         err = PTR_ERR(key->u.aes_cmac.tfm);
479                         kfree(key);
480                         return ERR_PTR(err);
481                 }
482                 break;
483         case WLAN_CIPHER_SUITE_BIP_GMAC_128:
484         case WLAN_CIPHER_SUITE_BIP_GMAC_256:
485                 key->conf.iv_len = 0;
486                 key->conf.icv_len = sizeof(struct ieee80211_mmie_16);
487                 if (seq)
488                         for (j = 0; j < IEEE80211_GMAC_PN_LEN; j++)
489                                 key->u.aes_gmac.rx_pn[j] =
490                                         seq[IEEE80211_GMAC_PN_LEN - j - 1];
491                 /* Initialize AES key state here as an optimization so that
492                  * it does not need to be initialized for every packet.
493                  */
494                 key->u.aes_gmac.tfm =
495                         ieee80211_aes_gmac_key_setup(key_data, key_len);
496                 if (IS_ERR(key->u.aes_gmac.tfm)) {
497                         err = PTR_ERR(key->u.aes_gmac.tfm);
498                         kfree(key);
499                         return ERR_PTR(err);
500                 }
501                 break;
502         case WLAN_CIPHER_SUITE_GCMP:
503         case WLAN_CIPHER_SUITE_GCMP_256:
504                 key->conf.iv_len = IEEE80211_GCMP_HDR_LEN;
505                 key->conf.icv_len = IEEE80211_GCMP_MIC_LEN;
506                 for (i = 0; seq && i < IEEE80211_NUM_TIDS + 1; i++)
507                         for (j = 0; j < IEEE80211_GCMP_PN_LEN; j++)
508                                 key->u.gcmp.rx_pn[i][j] =
509                                         seq[IEEE80211_GCMP_PN_LEN - j - 1];
510                 /* Initialize AES key state here as an optimization so that
511                  * it does not need to be initialized for every packet.
512                  */
513                 key->u.gcmp.tfm = ieee80211_aes_gcm_key_setup_encrypt(key_data,
514                                                                       key_len);
515                 if (IS_ERR(key->u.gcmp.tfm)) {
516                         err = PTR_ERR(key->u.gcmp.tfm);
517                         kfree(key);
518                         return ERR_PTR(err);
519                 }
520                 break;
521         default:
522                 if (cs) {
523                         if (seq_len && seq_len != cs->pn_len) {
524                                 kfree(key);
525                                 return ERR_PTR(-EINVAL);
526                         }
527 
528                         key->conf.iv_len = cs->hdr_len;
529                         key->conf.icv_len = cs->mic_len;
530                         for (i = 0; i < IEEE80211_NUM_TIDS + 1; i++)
531                                 for (j = 0; j < seq_len; j++)
532                                         key->u.gen.rx_pn[i][j] =
533                                                         seq[seq_len - j - 1];
534                         key->flags |= KEY_FLAG_CIPHER_SCHEME;
535                 }
536         }
537         memcpy(key->conf.key, key_data, key_len);
538         INIT_LIST_HEAD(&key->list);
539 
540         return key;
541 }
542 
543 static void ieee80211_key_free_common(struct ieee80211_key *key)
544 {
545         switch (key->conf.cipher) {
546         case WLAN_CIPHER_SUITE_CCMP:
547         case WLAN_CIPHER_SUITE_CCMP_256:
548                 ieee80211_aes_key_free(key->u.ccmp.tfm);
549                 break;
550         case WLAN_CIPHER_SUITE_AES_CMAC:
551         case WLAN_CIPHER_SUITE_BIP_CMAC_256:
552                 ieee80211_aes_cmac_key_free(key->u.aes_cmac.tfm);
553                 break;
554         case WLAN_CIPHER_SUITE_BIP_GMAC_128:
555         case WLAN_CIPHER_SUITE_BIP_GMAC_256:
556                 ieee80211_aes_gmac_key_free(key->u.aes_gmac.tfm);
557                 break;
558         case WLAN_CIPHER_SUITE_GCMP:
559         case WLAN_CIPHER_SUITE_GCMP_256:
560                 ieee80211_aes_gcm_key_free(key->u.gcmp.tfm);
561                 break;
562         }
563         kzfree(key);
564 }
565 
566 static void __ieee80211_key_destroy(struct ieee80211_key *key,
567                                     bool delay_tailroom)
568 {
569         if (key->local)
570                 ieee80211_key_disable_hw_accel(key);
571 
572         if (key->local) {
573                 struct ieee80211_sub_if_data *sdata = key->sdata;
574 
575                 ieee80211_debugfs_key_remove(key);
576 
577                 if (delay_tailroom) {
578                         /* see ieee80211_delayed_tailroom_dec */
579                         sdata->crypto_tx_tailroom_pending_dec++;
580                         schedule_delayed_work(&sdata->dec_tailroom_needed_wk,
581                                               HZ/2);
582                 } else {
583                         decrease_tailroom_need_count(sdata, 1);
584                 }
585         }
586 
587         ieee80211_key_free_common(key);
588 }
589 
590 static void ieee80211_key_destroy(struct ieee80211_key *key,
591                                   bool delay_tailroom)
592 {
593         if (!key)
594                 return;
595 
596         /*
597          * Synchronize so the TX path and rcu key iterators
598          * can no longer be using this key before we free/remove it.
599          */
600         synchronize_net();
601 
602         __ieee80211_key_destroy(key, delay_tailroom);
603 }
604 
605 void ieee80211_key_free_unused(struct ieee80211_key *key)
606 {
607         WARN_ON(key->sdata || key->local);
608         ieee80211_key_free_common(key);
609 }
610 
611 int ieee80211_key_link(struct ieee80211_key *key,
612                        struct ieee80211_sub_if_data *sdata,
613                        struct sta_info *sta)
614 {
615         struct ieee80211_local *local = sdata->local;
616         struct ieee80211_key *old_key;
617         int idx, ret;
618         bool pairwise;
619 
620         pairwise = key->conf.flags & IEEE80211_KEY_FLAG_PAIRWISE;
621         idx = key->conf.keyidx;
622         key->local = sdata->local;
623         key->sdata = sdata;
624         key->sta = sta;
625 
626         mutex_lock(&sdata->local->key_mtx);
627 
628         if (sta && pairwise)
629                 old_key = key_mtx_dereference(sdata->local, sta->ptk[idx]);
630         else if (sta)
631                 old_key = key_mtx_dereference(sdata->local, sta->gtk[idx]);
632         else
633                 old_key = key_mtx_dereference(sdata->local, sdata->keys[idx]);
634 
635         increment_tailroom_need_count(sdata);
636 
637         ieee80211_key_replace(sdata, sta, pairwise, old_key, key);
638         ieee80211_key_destroy(old_key, true);
639 
640         ieee80211_debugfs_key_add(key);
641 
642         if (!local->wowlan) {
643                 ret = ieee80211_key_enable_hw_accel(key);
644                 if (ret)
645                         ieee80211_key_free(key, true);
646         } else {
647                 ret = 0;
648         }
649 
650         mutex_unlock(&sdata->local->key_mtx);
651 
652         return ret;
653 }
654 
655 void ieee80211_key_free(struct ieee80211_key *key, bool delay_tailroom)
656 {
657         if (!key)
658                 return;
659 
660         /*
661          * Replace key with nothingness if it was ever used.
662          */
663         if (key->sdata)
664                 ieee80211_key_replace(key->sdata, key->sta,
665                                 key->conf.flags & IEEE80211_KEY_FLAG_PAIRWISE,
666                                 key, NULL);
667         ieee80211_key_destroy(key, delay_tailroom);
668 }
669 
670 void ieee80211_enable_keys(struct ieee80211_sub_if_data *sdata)
671 {
672         struct ieee80211_key *key;
673         struct ieee80211_sub_if_data *vlan;
674 
675         ASSERT_RTNL();
676 
677         if (WARN_ON(!ieee80211_sdata_running(sdata)))
678                 return;
679 
680         mutex_lock(&sdata->local->key_mtx);
681 
682         WARN_ON_ONCE(sdata->crypto_tx_tailroom_needed_cnt ||
683                      sdata->crypto_tx_tailroom_pending_dec);
684 
685         if (sdata->vif.type == NL80211_IFTYPE_AP) {
686                 list_for_each_entry(vlan, &sdata->u.ap.vlans, u.vlan.list)
687                         WARN_ON_ONCE(vlan->crypto_tx_tailroom_needed_cnt ||
688                                      vlan->crypto_tx_tailroom_pending_dec);
689         }
690 
691         list_for_each_entry(key, &sdata->key_list, list) {
692                 increment_tailroom_need_count(sdata);
693                 ieee80211_key_enable_hw_accel(key);
694         }
695 
696         mutex_unlock(&sdata->local->key_mtx);
697 }
698 
699 void ieee80211_reset_crypto_tx_tailroom(struct ieee80211_sub_if_data *sdata)
700 {
701         struct ieee80211_sub_if_data *vlan;
702 
703         mutex_lock(&sdata->local->key_mtx);
704 
705         sdata->crypto_tx_tailroom_needed_cnt = 0;
706 
707         if (sdata->vif.type == NL80211_IFTYPE_AP) {
708                 list_for_each_entry(vlan, &sdata->u.ap.vlans, u.vlan.list)
709                         vlan->crypto_tx_tailroom_needed_cnt = 0;
710         }
711 
712         mutex_unlock(&sdata->local->key_mtx);
713 }
714 
715 void ieee80211_iter_keys(struct ieee80211_hw *hw,
716                          struct ieee80211_vif *vif,
717                          void (*iter)(struct ieee80211_hw *hw,
718                                       struct ieee80211_vif *vif,
719                                       struct ieee80211_sta *sta,
720                                       struct ieee80211_key_conf *key,
721                                       void *data),
722                          void *iter_data)
723 {
724         struct ieee80211_local *local = hw_to_local(hw);
725         struct ieee80211_key *key, *tmp;
726         struct ieee80211_sub_if_data *sdata;
727 
728         ASSERT_RTNL();
729 
730         mutex_lock(&local->key_mtx);
731         if (vif) {
732                 sdata = vif_to_sdata(vif);
733                 list_for_each_entry_safe(key, tmp, &sdata->key_list, list)
734                         iter(hw, &sdata->vif,
735                              key->sta ? &key->sta->sta : NULL,
736                              &key->conf, iter_data);
737         } else {
738                 list_for_each_entry(sdata, &local->interfaces, list)
739                         list_for_each_entry_safe(key, tmp,
740                                                  &sdata->key_list, list)
741                                 iter(hw, &sdata->vif,
742                                      key->sta ? &key->sta->sta : NULL,
743                                      &key->conf, iter_data);
744         }
745         mutex_unlock(&local->key_mtx);
746 }
747 EXPORT_SYMBOL(ieee80211_iter_keys);
748 
749 static void
750 _ieee80211_iter_keys_rcu(struct ieee80211_hw *hw,
751                          struct ieee80211_sub_if_data *sdata,
752                          void (*iter)(struct ieee80211_hw *hw,
753                                       struct ieee80211_vif *vif,
754                                       struct ieee80211_sta *sta,
755                                       struct ieee80211_key_conf *key,
756                                       void *data),
757                          void *iter_data)
758 {
759         struct ieee80211_key *key;
760 
761         list_for_each_entry_rcu(key, &sdata->key_list, list) {
762                 /* skip keys of station in removal process */
763                 if (key->sta && key->sta->removed)
764                         continue;
765                 if (!(key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE))
766                         continue;
767 
768                 iter(hw, &sdata->vif,
769                      key->sta ? &key->sta->sta : NULL,
770                      &key->conf, iter_data);
771         }
772 }
773 
774 void ieee80211_iter_keys_rcu(struct ieee80211_hw *hw,
775                              struct ieee80211_vif *vif,
776                              void (*iter)(struct ieee80211_hw *hw,
777                                           struct ieee80211_vif *vif,
778                                           struct ieee80211_sta *sta,
779                                           struct ieee80211_key_conf *key,
780                                           void *data),
781                              void *iter_data)
782 {
783         struct ieee80211_local *local = hw_to_local(hw);
784         struct ieee80211_sub_if_data *sdata;
785 
786         if (vif) {
787                 sdata = vif_to_sdata(vif);
788                 _ieee80211_iter_keys_rcu(hw, sdata, iter, iter_data);
789         } else {
790                 list_for_each_entry_rcu(sdata, &local->interfaces, list)
791                         _ieee80211_iter_keys_rcu(hw, sdata, iter, iter_data);
792         }
793 }
794 EXPORT_SYMBOL(ieee80211_iter_keys_rcu);
795 
796 static void ieee80211_free_keys_iface(struct ieee80211_sub_if_data *sdata,
797                                       struct list_head *keys)
798 {
799         struct ieee80211_key *key, *tmp;
800 
801         decrease_tailroom_need_count(sdata,
802                                      sdata->crypto_tx_tailroom_pending_dec);
803         sdata->crypto_tx_tailroom_pending_dec = 0;
804 
805         ieee80211_debugfs_key_remove_mgmt_default(sdata);
806 
807         list_for_each_entry_safe(key, tmp, &sdata->key_list, list) {
808                 ieee80211_key_replace(key->sdata, key->sta,
809                                 key->conf.flags & IEEE80211_KEY_FLAG_PAIRWISE,
810                                 key, NULL);
811                 list_add_tail(&key->list, keys);
812         }
813 
814         ieee80211_debugfs_key_update_default(sdata);
815 }
816 
817 void ieee80211_free_keys(struct ieee80211_sub_if_data *sdata,
818                          bool force_synchronize)
819 {
820         struct ieee80211_local *local = sdata->local;
821         struct ieee80211_sub_if_data *vlan;
822         struct ieee80211_sub_if_data *master;
823         struct ieee80211_key *key, *tmp;
824         LIST_HEAD(keys);
825 
826         cancel_delayed_work_sync(&sdata->dec_tailroom_needed_wk);
827 
828         mutex_lock(&local->key_mtx);
829 
830         ieee80211_free_keys_iface(sdata, &keys);
831 
832         if (sdata->vif.type == NL80211_IFTYPE_AP) {
833                 list_for_each_entry(vlan, &sdata->u.ap.vlans, u.vlan.list)
834                         ieee80211_free_keys_iface(vlan, &keys);
835         }
836 
837         if (!list_empty(&keys) || force_synchronize)
838                 synchronize_net();
839         list_for_each_entry_safe(key, tmp, &keys, list)
840                 __ieee80211_key_destroy(key, false);
841 
842         if (sdata->vif.type == NL80211_IFTYPE_AP_VLAN) {
843                 if (sdata->bss) {
844                         master = container_of(sdata->bss,
845                                               struct ieee80211_sub_if_data,
846                                               u.ap);
847 
848                         WARN_ON_ONCE(sdata->crypto_tx_tailroom_needed_cnt !=
849                                      master->crypto_tx_tailroom_needed_cnt);
850                 }
851         } else {
852                 WARN_ON_ONCE(sdata->crypto_tx_tailroom_needed_cnt ||
853                              sdata->crypto_tx_tailroom_pending_dec);
854         }
855 
856         if (sdata->vif.type == NL80211_IFTYPE_AP) {
857                 list_for_each_entry(vlan, &sdata->u.ap.vlans, u.vlan.list)
858                         WARN_ON_ONCE(vlan->crypto_tx_tailroom_needed_cnt ||
859                                      vlan->crypto_tx_tailroom_pending_dec);
860         }
861 
862         mutex_unlock(&local->key_mtx);
863 }
864 
865 void ieee80211_free_sta_keys(struct ieee80211_local *local,
866                              struct sta_info *sta)
867 {
868         struct ieee80211_key *key;
869         int i;
870 
871         mutex_lock(&local->key_mtx);
872         for (i = 0; i < ARRAY_SIZE(sta->gtk); i++) {
873                 key = key_mtx_dereference(local, sta->gtk[i]);
874                 if (!key)
875                         continue;
876                 ieee80211_key_replace(key->sdata, key->sta,
877                                 key->conf.flags & IEEE80211_KEY_FLAG_PAIRWISE,
878                                 key, NULL);
879                 __ieee80211_key_destroy(key, true);
880         }
881 
882         for (i = 0; i < NUM_DEFAULT_KEYS; i++) {
883                 key = key_mtx_dereference(local, sta->ptk[i]);
884                 if (!key)
885                         continue;
886                 ieee80211_key_replace(key->sdata, key->sta,
887                                 key->conf.flags & IEEE80211_KEY_FLAG_PAIRWISE,
888                                 key, NULL);
889                 __ieee80211_key_destroy(key, true);
890         }
891 
892         mutex_unlock(&local->key_mtx);
893 }
894 
895 void ieee80211_delayed_tailroom_dec(struct work_struct *wk)
896 {
897         struct ieee80211_sub_if_data *sdata;
898 
899         sdata = container_of(wk, struct ieee80211_sub_if_data,
900                              dec_tailroom_needed_wk.work);
901 
902         /*
903          * The reason for the delayed tailroom needed decrementing is to
904          * make roaming faster: during roaming, all keys are first deleted
905          * and then new keys are installed. The first new key causes the
906          * crypto_tx_tailroom_needed_cnt to go from 0 to 1, which invokes
907          * the cost of synchronize_net() (which can be slow). Avoid this
908          * by deferring the crypto_tx_tailroom_needed_cnt decrementing on
909          * key removal for a while, so if we roam the value is larger than
910          * zero and no 0->1 transition happens.
911          *
912          * The cost is that if the AP switching was from an AP with keys
913          * to one without, we still allocate tailroom while it would no
914          * longer be needed. However, in the typical (fast) roaming case
915          * within an ESS this usually won't happen.
916          */
917 
918         mutex_lock(&sdata->local->key_mtx);
919         decrease_tailroom_need_count(sdata,
920                                      sdata->crypto_tx_tailroom_pending_dec);
921         sdata->crypto_tx_tailroom_pending_dec = 0;
922         mutex_unlock(&sdata->local->key_mtx);
923 }
924 
925 void ieee80211_gtk_rekey_notify(struct ieee80211_vif *vif, const u8 *bssid,
926                                 const u8 *replay_ctr, gfp_t gfp)
927 {
928         struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
929 
930         trace_api_gtk_rekey_notify(sdata, bssid, replay_ctr);
931 
932         cfg80211_gtk_rekey_notify(sdata->dev, bssid, replay_ctr, gfp);
933 }
934 EXPORT_SYMBOL_GPL(ieee80211_gtk_rekey_notify);
935 
936 void ieee80211_get_key_rx_seq(struct ieee80211_key_conf *keyconf,
937                               int tid, struct ieee80211_key_seq *seq)
938 {
939         struct ieee80211_key *key;
940         const u8 *pn;
941 
942         key = container_of(keyconf, struct ieee80211_key, conf);
943 
944         switch (key->conf.cipher) {
945         case WLAN_CIPHER_SUITE_TKIP:
946                 if (WARN_ON(tid < 0 || tid >= IEEE80211_NUM_TIDS))
947                         return;
948                 seq->tkip.iv32 = key->u.tkip.rx[tid].iv32;
949                 seq->tkip.iv16 = key->u.tkip.rx[tid].iv16;
950                 break;
951         case WLAN_CIPHER_SUITE_CCMP:
952         case WLAN_CIPHER_SUITE_CCMP_256:
953                 if (WARN_ON(tid < -1 || tid >= IEEE80211_NUM_TIDS))
954                         return;
955                 if (tid < 0)
956                         pn = key->u.ccmp.rx_pn[IEEE80211_NUM_TIDS];
957                 else
958                         pn = key->u.ccmp.rx_pn[tid];
959                 memcpy(seq->ccmp.pn, pn, IEEE80211_CCMP_PN_LEN);
960                 break;
961         case WLAN_CIPHER_SUITE_AES_CMAC:
962         case WLAN_CIPHER_SUITE_BIP_CMAC_256:
963                 if (WARN_ON(tid != 0))
964                         return;
965                 pn = key->u.aes_cmac.rx_pn;
966                 memcpy(seq->aes_cmac.pn, pn, IEEE80211_CMAC_PN_LEN);
967                 break;
968         case WLAN_CIPHER_SUITE_BIP_GMAC_128:
969         case WLAN_CIPHER_SUITE_BIP_GMAC_256:
970                 if (WARN_ON(tid != 0))
971                         return;
972                 pn = key->u.aes_gmac.rx_pn;
973                 memcpy(seq->aes_gmac.pn, pn, IEEE80211_GMAC_PN_LEN);
974                 break;
975         case WLAN_CIPHER_SUITE_GCMP:
976         case WLAN_CIPHER_SUITE_GCMP_256:
977                 if (WARN_ON(tid < -1 || tid >= IEEE80211_NUM_TIDS))
978                         return;
979                 if (tid < 0)
980                         pn = key->u.gcmp.rx_pn[IEEE80211_NUM_TIDS];
981                 else
982                         pn = key->u.gcmp.rx_pn[tid];
983                 memcpy(seq->gcmp.pn, pn, IEEE80211_GCMP_PN_LEN);
984                 break;
985         }
986 }
987 EXPORT_SYMBOL(ieee80211_get_key_rx_seq);
988 
989 void ieee80211_set_key_rx_seq(struct ieee80211_key_conf *keyconf,
990                               int tid, struct ieee80211_key_seq *seq)
991 {
992         struct ieee80211_key *key;
993         u8 *pn;
994 
995         key = container_of(keyconf, struct ieee80211_key, conf);
996 
997         switch (key->conf.cipher) {
998         case WLAN_CIPHER_SUITE_TKIP:
999                 if (WARN_ON(tid < 0 || tid >= IEEE80211_NUM_TIDS))
1000                         return;
1001                 key->u.tkip.rx[tid].iv32 = seq->tkip.iv32;
1002                 key->u.tkip.rx[tid].iv16 = seq->tkip.iv16;
1003                 break;
1004         case WLAN_CIPHER_SUITE_CCMP:
1005         case WLAN_CIPHER_SUITE_CCMP_256:
1006                 if (WARN_ON(tid < -1 || tid >= IEEE80211_NUM_TIDS))
1007                         return;
1008                 if (tid < 0)
1009                         pn = key->u.ccmp.rx_pn[IEEE80211_NUM_TIDS];
1010                 else
1011                         pn = key->u.ccmp.rx_pn[tid];
1012                 memcpy(pn, seq->ccmp.pn, IEEE80211_CCMP_PN_LEN);
1013                 break;
1014         case WLAN_CIPHER_SUITE_AES_CMAC:
1015         case WLAN_CIPHER_SUITE_BIP_CMAC_256:
1016                 if (WARN_ON(tid != 0))
1017                         return;
1018                 pn = key->u.aes_cmac.rx_pn;
1019                 memcpy(pn, seq->aes_cmac.pn, IEEE80211_CMAC_PN_LEN);
1020                 break;
1021         case WLAN_CIPHER_SUITE_BIP_GMAC_128:
1022         case WLAN_CIPHER_SUITE_BIP_GMAC_256:
1023                 if (WARN_ON(tid != 0))
1024                         return;
1025                 pn = key->u.aes_gmac.rx_pn;
1026                 memcpy(pn, seq->aes_gmac.pn, IEEE80211_GMAC_PN_LEN);
1027                 break;
1028         case WLAN_CIPHER_SUITE_GCMP:
1029         case WLAN_CIPHER_SUITE_GCMP_256:
1030                 if (WARN_ON(tid < -1 || tid >= IEEE80211_NUM_TIDS))
1031                         return;
1032                 if (tid < 0)
1033                         pn = key->u.gcmp.rx_pn[IEEE80211_NUM_TIDS];
1034                 else
1035                         pn = key->u.gcmp.rx_pn[tid];
1036                 memcpy(pn, seq->gcmp.pn, IEEE80211_GCMP_PN_LEN);
1037                 break;
1038         default:
1039                 WARN_ON(1);
1040                 break;
1041         }
1042 }
1043 EXPORT_SYMBOL_GPL(ieee80211_set_key_rx_seq);
1044 
1045 void ieee80211_remove_key(struct ieee80211_key_conf *keyconf)
1046 {
1047         struct ieee80211_key *key;
1048 
1049         key = container_of(keyconf, struct ieee80211_key, conf);
1050 
1051         assert_key_lock(key->local);
1052 
1053         /*
1054          * if key was uploaded, we assume the driver will/has remove(d)
1055          * it, so adjust bookkeeping accordingly
1056          */
1057         if (key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE) {
1058                 key->flags &= ~KEY_FLAG_UPLOADED_TO_HARDWARE;
1059 
1060                 if (!((key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_MMIC) ||
1061                       (key->conf.flags & IEEE80211_KEY_FLAG_RESERVE_TAILROOM)))
1062                         increment_tailroom_need_count(key->sdata);
1063         }
1064 
1065         ieee80211_key_free(key, false);
1066 }
1067 EXPORT_SYMBOL_GPL(ieee80211_remove_key);
1068 
1069 struct ieee80211_key_conf *
1070 ieee80211_gtk_rekey_add(struct ieee80211_vif *vif,
1071                         struct ieee80211_key_conf *keyconf)
1072 {
1073         struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
1074         struct ieee80211_local *local = sdata->local;
1075         struct ieee80211_key *key;
1076         int err;
1077 
1078         if (WARN_ON(!local->wowlan))
1079                 return ERR_PTR(-EINVAL);
1080 
1081         if (WARN_ON(vif->type != NL80211_IFTYPE_STATION))
1082                 return ERR_PTR(-EINVAL);
1083 
1084         key = ieee80211_key_alloc(keyconf->cipher, keyconf->keyidx,
1085                                   keyconf->keylen, keyconf->key,
1086                                   0, NULL, NULL);
1087         if (IS_ERR(key))
1088                 return ERR_CAST(key);
1089 
1090         if (sdata->u.mgd.mfp != IEEE80211_MFP_DISABLED)
1091                 key->conf.flags |= IEEE80211_KEY_FLAG_RX_MGMT;
1092 
1093         err = ieee80211_key_link(key, sdata, NULL);
1094         if (err)
1095                 return ERR_PTR(err);
1096 
1097         return &key->conf;
1098 }
1099 EXPORT_SYMBOL_GPL(ieee80211_gtk_rekey_add);
1100 

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