net/mac80211/key.c

   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  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License version 2 as
  10  * published by the Free Software Foundation.
  11  */
  12
  13 #include <linux/if_ether.h>
  14 #include <linux/etherdevice.h>
  15 #include <linux/list.h>
  16 #include <linux/rcupdate.h>
  17 #include <linux/rtnetlink.h>
  18 #include <linux/slab.h>
  19 #include <linux/export.h>
  20 #include <net/mac80211.h>
  21 #include <asm/unaligned.h>
  22 #include "ieee80211_i.h"
  23 #include "driver-ops.h"
  24 #include "debugfs_key.h"
  25 #include "aes_ccm.h"
  26 #include "aes_cmac.h"
  27 #include "aes_gmac.h"
  28 #include "aes_gcm.h"
  29
  30
  31 /**
  32  * DOC: Key handling basics
  33  *
  34  * Key handling in mac80211 is done based on per-interface (sub_if_data)
  35  * keys and per-station keys. Since each station belongs to an interface,
  36  * each station key also belongs to that interface.
  37  *
  38  * Hardware acceleration is done on a best-effort basis for algorithms
  39  * that are implemented in software,  for each key the hardware is asked
  40  * to enable that key for offloading but if it cannot do that the key is
  41  * simply kept for software encryption (unless it is for an algorithm
  42  * that isn't implemented in software).
  43  * There is currently no way of knowing whether a key is handled in SW
  44  * or HW except by looking into debugfs.
  45  *
  46  * All key management is internally protected by a mutex. Within all
  47  * other parts of mac80211, key references are, just as STA structure
  48  * references, protected by RCU. Note, however, that some things are
  49  * unprotected, namely the key->sta dereferences within the hardware
  50  * acceleration functions. This means that sta_info_destroy() must
  51  * remove the key which waits for an RCU grace period.
  52  */
  53
  54 static const u8 bcast_addr[ETH_ALEN] = { 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF };
  55
  56 static void assert_key_lock(struct ieee80211_local *local)
  57 {
  58         lockdep_assert_held(&local->key_mtx);
  59 }
  60
  61 static void
  62 update_vlan_tailroom_need_count(struct ieee80211_sub_if_data *sdata, int delta)
  63 {
  64         struct ieee80211_sub_if_data *vlan;
  65
  66         if (sdata->vif.type != NL80211_IFTYPE_AP)
  67                 return;
  68
  69         mutex_lock(&sdata->local->mtx);
  70
  71         list_for_each_entry(vlan, &sdata->u.ap.vlans, u.vlan.list)
  72                 vlan->crypto_tx_tailroom_needed_cnt += delta;
  73
  74         mutex_unlock(&sdata->local->mtx);
  75 }
  76
  77 static void increment_tailroom_need_count(struct ieee80211_sub_if_data *sdata)
  78 {
  79         /*
  80          * When this count is zero, SKB resizing for allocating tailroom
  81          * for IV or MMIC is skipped. But, this check has created two race
  82          * cases in xmit path while transiting from zero count to one:
  83          *
  84          * 1. SKB resize was skipped because no key was added but just before
  85          * the xmit key is added and SW encryption kicks off.
  86          *
  87          * 2. SKB resize was skipped because all the keys were hw planted but
  88          * just before xmit one of the key is deleted and SW encryption kicks
  89          * off.
  90          *
  91          * In both the above case SW encryption will find not enough space for
  92          * tailroom and exits with WARN_ON. (See WARN_ONs at wpa.c)
  93          *
  94          * Solution has been explained at
  95          * http://mid.gmane.org/1308590980.4322.19.camel@jlt3.sipsolutions.net
  96          */
  97
  98         update_vlan_tailroom_need_count(sdata, 1);
  99
 100         if (!sdata->crypto_tx_tailroom_needed_cnt++) {
 101                 /*
 102                  * Flush all XMIT packets currently using HW encryption or no
 103                  * encryption at all if the count transition is from 0 -> 1.
 104                  */
 105                 synchronize_net();
 106         }
 107 }
 108
 109 static void decrease_tailroom_need_count(struct ieee80211_sub_if_data *sdata,
 110                                          int delta)
 111 {
 112         WARN_ON_ONCE(sdata->crypto_tx_tailroom_needed_cnt < delta);
 113
 114         update_vlan_tailroom_need_count(sdata, -delta);
 115         sdata->crypto_tx_tailroom_needed_cnt -= delta;
 116 }
 117
 118 static int ieee80211_key_enable_hw_accel(struct ieee80211_key *key)
 119 {
 120         struct ieee80211_sub_if_data *sdata;
 121         struct sta_info *sta;
 122         int ret = -EOPNOTSUPP;
 123
 124         might_sleep();
 125
 126         if (key->flags & KEY_FLAG_TAINTED) {
 127                 /* If we get here, it's during resume and the key is
 128                  * tainted so shouldn't be used/programmed any more.
 129                  * However, its flags may still indicate that it was
 130                  * programmed into the device (since we're in resume)
 131                  * so clear that flag now to avoid trying to remove
 132                  * it again later.
 133                  */
 134                 key->flags &= ~KEY_FLAG_UPLOADED_TO_HARDWARE;
 135                 return -EINVAL;
 136         }
 137
 138         if (!key->local->ops->set_key)
 139                 goto out_unsupported;
 140
 141         assert_key_lock(key->local);
 142
 143         sta = key->sta;
 144
 145         /*
 146          * If this is a per-STA GTK, check if it
 147          * is supported; if not, return.
 148          */
 149         if (sta && !(key->conf.flags & IEEE80211_KEY_FLAG_PAIRWISE) &&
 150             !(key->local->hw.flags & IEEE80211_HW_SUPPORTS_PER_STA_GTK))
 151                 goto out_unsupported;
 152
 153         if (sta && !sta->uploaded)
 154                 goto out_unsupported;
 155
 156         sdata = key->sdata;
 157         if (sdata->vif.type == NL80211_IFTYPE_AP_VLAN) {
 158                 /*
 159                  * The driver doesn't know anything about VLAN interfaces.
 160                  * Hence, don't send GTKs for VLAN interfaces to the driver.
 161                  */
 162                 if (!(key->conf.flags & IEEE80211_KEY_FLAG_PAIRWISE))
 163                         goto out_unsupported;
 164         }
 165
 166         ret = drv_set_key(key->local, SET_KEY, sdata,
 167                           sta ? &sta->sta : NULL, &key->conf);
 168
 169         if (!ret) {
 170                 key->flags |= KEY_FLAG_UPLOADED_TO_HARDWARE;
 171
 172                 if (!((key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_MMIC) ||
 173                       (key->conf.flags & IEEE80211_KEY_FLAG_RESERVE_TAILROOM)))
 174                         decrease_tailroom_need_count(sdata, 1);
 175
 176                 WARN_ON((key->conf.flags & IEEE80211_KEY_FLAG_PUT_IV_SPACE) &&
 177                         (key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_IV));
 178
 179                 return 0;
 180         }
 181
 182         if (ret != -ENOSPC && ret != -EOPNOTSUPP && ret != 1)
 183                 sdata_err(sdata,
 184                           "failed to set key (%d, %pM) to hardware (%d)\n",
 185                           key->conf.keyidx,
 186                           sta ? sta->sta.addr : bcast_addr, ret);
 187
 188  out_unsupported:
 189         switch (key->conf.cipher) {
 190         case WLAN_CIPHER_SUITE_WEP40:
 191         case WLAN_CIPHER_SUITE_WEP104:
 192         case WLAN_CIPHER_SUITE_TKIP:
 193         case WLAN_CIPHER_SUITE_CCMP:
 194         case WLAN_CIPHER_SUITE_CCMP_256:
 195         case WLAN_CIPHER_SUITE_AES_CMAC:
 196         case WLAN_CIPHER_SUITE_BIP_CMAC_256:
 197         case WLAN_CIPHER_SUITE_BIP_GMAC_128:
 198         case WLAN_CIPHER_SUITE_BIP_GMAC_256:
 199         case WLAN_CIPHER_SUITE_GCMP:
 200         case WLAN_CIPHER_SUITE_GCMP_256:
 201                 /* all of these we can do in software - if driver can */
 202                 if (ret == 1)
 203                         return 0;
 204                 if (key->local->hw.flags & IEEE80211_HW_SW_CRYPTO_CONTROL)
 205                         return -EINVAL;
 206                 return 0;
 207         default:
 208                 return -EINVAL;
 209         }
 210 }
 211
 212 static void ieee80211_key_disable_hw_accel(struct ieee80211_key *key)
 213 {
 214         struct ieee80211_sub_if_data *sdata;
 215         struct sta_info *sta;
 216         int ret;
 217
 218         might_sleep();
 219
 220         if (!key || !key->local->ops->set_key)
 221                 return;
 222
 223         assert_key_lock(key->local);
 224
 225         if (!(key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE))
 226                 return;
 227
 228         sta = key->sta;
 229         sdata = key->sdata;
 230
 231         if (!((key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_MMIC) ||
 232               (key->conf.flags & IEEE80211_KEY_FLAG_RESERVE_TAILROOM)))
 233                 increment_tailroom_need_count(sdata);
 234
 235         ret = drv_set_key(key->local, DISABLE_KEY, sdata,
 236                           sta ? &sta->sta : NULL, &key->conf);
 237
 238         if (ret)
 239                 sdata_err(sdata,
 240                           "failed to remove key (%d, %pM) from hardware (%d)\n",
 241                           key->conf.keyidx,
 242                           sta ? sta->sta.addr : bcast_addr, ret);
 243
 244         key->flags &= ~KEY_FLAG_UPLOADED_TO_HARDWARE;
 245 }
 246
 247 static void __ieee80211_set_default_key(struct ieee80211_sub_if_data *sdata,
 248                                         int idx, bool uni, bool multi)
 249 {
 250         struct ieee80211_key *key = NULL;
 251
 252         assert_key_lock(sdata->local);
 253
 254         if (idx >= 0 && idx < NUM_DEFAULT_KEYS)
 255                 key = key_mtx_dereference(sdata->local, sdata->keys[idx]);
 256
 257         if (uni) {
 258                 rcu_assign_pointer(sdata->default_unicast_key, key);
 259                 ieee80211_check_fast_xmit_iface(sdata);
 260                 drv_set_default_unicast_key(sdata->local, sdata, idx);
 261         }
 262
 263         if (multi)
 264                 rcu_assign_pointer(sdata->default_multicast_key, key);
 265
 266         ieee80211_debugfs_key_update_default(sdata);
 267 }
 268
 269 void ieee80211_set_default_key(struct ieee80211_sub_if_data *sdata, int idx,
 270                                bool uni, bool multi)
 271 {
 272         mutex_lock(&sdata->local->key_mtx);
 273         __ieee80211_set_default_key(sdata, idx, uni, multi);
 274         mutex_unlock(&sdata->local->key_mtx);
 275 }
 276
 277 static void
 278 __ieee80211_set_default_mgmt_key(struct ieee80211_sub_if_data *sdata, int idx)
 279 {
 280         struct ieee80211_key *key = NULL;
 281
 282         assert_key_lock(sdata->local);
 283
 284         if (idx >= NUM_DEFAULT_KEYS &&
 285             idx < NUM_DEFAULT_KEYS + NUM_DEFAULT_MGMT_KEYS)
 286                 key = key_mtx_dereference(sdata->local, sdata->keys[idx]);
 287
 288         rcu_assign_pointer(sdata->default_mgmt_key, key);
 289
 290         ieee80211_debugfs_key_update_default(sdata);
 291 }
 292
 293 void ieee80211_set_default_mgmt_key(struct ieee80211_sub_if_data *sdata,
 294                                     int idx)
 295 {
 296         mutex_lock(&sdata->local->key_mtx);
 297         __ieee80211_set_default_mgmt_key(sdata, idx);
 298         mutex_unlock(&sdata->local->key_mtx);
 299 }
 300
 301
 302 static void ieee80211_key_replace(struct ieee80211_sub_if_data *sdata,
 303                                   struct sta_info *sta,
 304                                   bool pairwise,
 305                                   struct ieee80211_key *old,
 306                                   struct ieee80211_key *new)
 307 {
 308         int idx;
 309         bool defunikey, defmultikey, defmgmtkey;
 310
 311         /* caller must provide at least one old/new */
 312         if (WARN_ON(!new && !old))
 313                 return;
 314
 315         if (new)
 316                 list_add_tail(&new->list, &sdata->key_list);
 317
 318         WARN_ON(new && old && new->conf.keyidx != old->conf.keyidx);
 319
 320         if (old)
 321                 idx = old->conf.keyidx;
 322         else
 323                 idx = new->conf.keyidx;
 324
 325         if (sta) {
 326                 if (pairwise) {
 327                         rcu_assign_pointer(sta->ptk[idx], new);
 328                         sta->ptk_idx = idx;
 329                         ieee80211_check_fast_xmit(sta);
 330                 } else {
 331                         rcu_assign_pointer(sta->gtk[idx], new);
 332                         sta->gtk_idx = idx;
 333                 }
 334         } else {
 335                 defunikey = old &&
 336                         old == key_mtx_dereference(sdata->local,
 337                                                 sdata->default_unicast_key);
 338                 defmultikey = old &&
 339                         old == key_mtx_dereference(sdata->local,
 340                                                 sdata->default_multicast_key);
 341                 defmgmtkey = old &&
 342                         old == key_mtx_dereference(sdata->local,
 343                                                 sdata->default_mgmt_key);
 344
 345                 if (defunikey && !new)
 346                         __ieee80211_set_default_key(sdata, -1, true, false);
 347                 if (defmultikey && !new)
 348                         __ieee80211_set_default_key(sdata, -1, false, true);
 349                 if (defmgmtkey && !new)
 350                         __ieee80211_set_default_mgmt_key(sdata, -1);
 351
 352                 rcu_assign_pointer(sdata->keys[idx], new);
 353                 if (defunikey && new)
 354                         __ieee80211_set_default_key(sdata, new->conf.keyidx,
 355                                                     true, false);
 356                 if (defmultikey && new)
 357                         __ieee80211_set_default_key(sdata, new->conf.keyidx,
 358                                                     false, true);
 359                 if (defmgmtkey && new)
 360                         __ieee80211_set_default_mgmt_key(sdata,
 361                                                          new->conf.keyidx);
 362         }
 363
 364         if (old)
 365                 list_del(&old->list);
 366 }
 367
 368 struct ieee80211_key *
 369 ieee80211_key_alloc(u32 cipher, int idx, size_t key_len,
 370                     const u8 *key_data,
 371                     size_t seq_len, const u8 *seq,
 372                     const struct ieee80211_cipher_scheme *cs)
 373 {
 374         struct ieee80211_key *key;
 375         int i, j, err;
 376
 377         if (WARN_ON(idx < 0 || idx >= NUM_DEFAULT_KEYS + NUM_DEFAULT_MGMT_KEYS))
 378                 return ERR_PTR(-EINVAL);
 379
 380         key = kzalloc(sizeof(struct ieee80211_key) + key_len, GFP_KERNEL);
 381         if (!key)
 382                 return ERR_PTR(-ENOMEM);
 383
 384         /*
 385          * Default to software encryption; we'll later upload the
 386          * key to the hardware if possible.
 387          */
 388         key->conf.flags = 0;
 389         key->flags = 0;
 390
 391         key->conf.cipher = cipher;
 392         key->conf.keyidx = idx;
 393         key->conf.keylen = key_len;
 394         switch (cipher) {
 395         case WLAN_CIPHER_SUITE_WEP40:
 396         case WLAN_CIPHER_SUITE_WEP104:
 397                 key->conf.iv_len = IEEE80211_WEP_IV_LEN;
 398                 key->conf.icv_len = IEEE80211_WEP_ICV_LEN;
 399                 break;
 400         case WLAN_CIPHER_SUITE_TKIP:
 401                 key->conf.iv_len = IEEE80211_TKIP_IV_LEN;
 402                 key->conf.icv_len = IEEE80211_TKIP_ICV_LEN;
 403                 if (seq) {
 404                         for (i = 0; i < IEEE80211_NUM_TIDS; i++) {
 405                                 key->u.tkip.rx[i].iv32 =
 406                                         get_unaligned_le32(&seq[2]);
 407                                 key->u.tkip.rx[i].iv16 =
 408                                         get_unaligned_le16(seq);
 409                         }
 410                 }
 411                 spin_lock_init(&key->u.tkip.txlock);
 412                 break;
 413         case WLAN_CIPHER_SUITE_CCMP:
 414                 key->conf.iv_len = IEEE80211_CCMP_HDR_LEN;
 415                 key->conf.icv_len = IEEE80211_CCMP_MIC_LEN;
 416                 if (seq) {
 417                         for (i = 0; i < IEEE80211_NUM_TIDS + 1; i++)
 418                                 for (j = 0; j < IEEE80211_CCMP_PN_LEN; j++)
 419                                         key->u.ccmp.rx_pn[i][j] =
 420                                                 seq[IEEE80211_CCMP_PN_LEN - j - 1];
 421                 }
 422                 /*
 423                  * Initialize AES key state here as an optimization so that
 424                  * it does not need to be initialized for every packet.
 425                  */
 426                 key->u.ccmp.tfm = ieee80211_aes_key_setup_encrypt(
 427                         key_data, key_len, IEEE80211_CCMP_MIC_LEN);
 428                 if (IS_ERR(key->u.ccmp.tfm)) {
 429                         err = PTR_ERR(key->u.ccmp.tfm);
 430                         kfree(key);
 431                         return ERR_PTR(err);
 432                 }
 433                 break;
 434         case WLAN_CIPHER_SUITE_CCMP_256:
 435                 key->conf.iv_len = IEEE80211_CCMP_256_HDR_LEN;
 436                 key->conf.icv_len = IEEE80211_CCMP_256_MIC_LEN;
 437                 for (i = 0; seq && i < IEEE80211_NUM_TIDS + 1; i++)
 438                         for (j = 0; j < IEEE80211_CCMP_256_PN_LEN; j++)
 439                                 key->u.ccmp.rx_pn[i][j] =
 440                                         seq[IEEE80211_CCMP_256_PN_LEN - j - 1];
 441                 /* Initialize AES key state here as an optimization so that
 442                  * it does not need to be initialized for every packet.
 443                  */
 444                 key->u.ccmp.tfm = ieee80211_aes_key_setup_encrypt(
 445                         key_data, key_len, IEEE80211_CCMP_256_MIC_LEN);
 446                 if (IS_ERR(key->u.ccmp.tfm)) {
 447                         err = PTR_ERR(key->u.ccmp.tfm);
 448                         kfree(key);
 449                         return ERR_PTR(err);
 450                 }
 451                 break;
 452         case WLAN_CIPHER_SUITE_AES_CMAC:
 453         case WLAN_CIPHER_SUITE_BIP_CMAC_256:
 454                 key->conf.iv_len = 0;
 455                 if (cipher == WLAN_CIPHER_SUITE_AES_CMAC)
 456                         key->conf.icv_len = sizeof(struct ieee80211_mmie);
 457                 else
 458                         key->conf.icv_len = sizeof(struct ieee80211_mmie_16);
 459                 if (seq)
 460                         for (j = 0; j < IEEE80211_CMAC_PN_LEN; j++)
 461                                 key->u.aes_cmac.rx_pn[j] =
 462                                         seq[IEEE80211_CMAC_PN_LEN - j - 1];
 463                 /*
 464                  * Initialize AES key state here as an optimization so that
 465                  * it does not need to be initialized for every packet.
 466                  */
 467                 key->u.aes_cmac.tfm =
 468                         ieee80211_aes_cmac_key_setup(key_data, key_len);
 469                 if (IS_ERR(key->u.aes_cmac.tfm)) {
 470                         err = PTR_ERR(key->u.aes_cmac.tfm);
 471                         kfree(key);
 472                         return ERR_PTR(err);
 473                 }
 474                 break;
 475         case WLAN_CIPHER_SUITE_BIP_GMAC_128:
 476         case WLAN_CIPHER_SUITE_BIP_GMAC_256:
 477                 key->conf.iv_len = 0;
 478                 key->conf.icv_len = sizeof(struct ieee80211_mmie_16);
 479                 if (seq)
 480                         for (j = 0; j < IEEE80211_GMAC_PN_LEN; j++)
 481                                 key->u.aes_gmac.rx_pn[j] =
 482                                         seq[IEEE80211_GMAC_PN_LEN - j - 1];
 483                 /* Initialize AES key state here as an optimization so that
 484                  * it does not need to be initialized for every packet.
 485                  */
 486                 key->u.aes_gmac.tfm =
 487                         ieee80211_aes_gmac_key_setup(key_data, key_len);
 488                 if (IS_ERR(key->u.aes_gmac.tfm)) {
 489                         err = PTR_ERR(key->u.aes_gmac.tfm);
 490                         kfree(key);
 491                         return ERR_PTR(err);
 492                 }
 493                 break;
 494         case WLAN_CIPHER_SUITE_GCMP:
 495         case WLAN_CIPHER_SUITE_GCMP_256:
 496                 key->conf.iv_len = IEEE80211_GCMP_HDR_LEN;
 497                 key->conf.icv_len = IEEE80211_GCMP_MIC_LEN;
 498                 for (i = 0; seq && i < IEEE80211_NUM_TIDS + 1; i++)
 499                         for (j = 0; j < IEEE80211_GCMP_PN_LEN; j++)
 500                                 key->u.gcmp.rx_pn[i][j] =
 501                                         seq[IEEE80211_GCMP_PN_LEN - j - 1];
 502                 /* Initialize AES key state here as an optimization so that
 503                  * it does not need to be initialized for every packet.
 504                  */
 505                 key->u.gcmp.tfm = ieee80211_aes_gcm_key_setup_encrypt(key_data,
 506                                                                       key_len);
 507                 if (IS_ERR(key->u.gcmp.tfm)) {
 508                         err = PTR_ERR(key->u.gcmp.tfm);
 509                         kfree(key);
 510                         return ERR_PTR(err);
 511                 }
 512                 break;
 513         default:
 514                 if (cs) {
 515                         if (seq_len && seq_len != cs->pn_len) {
 516                                 kfree(key);
 517                                 return ERR_PTR(-EINVAL);
 518                         }
 519
 520                         key->conf.iv_len = cs->hdr_len;
 521                         key->conf.icv_len = cs->mic_len;
 522                         for (i = 0; i < IEEE80211_NUM_TIDS + 1; i++)
 523                                 for (j = 0; j < seq_len; j++)
 524                                         key->u.gen.rx_pn[i][j] =
 525                                                         seq[seq_len - j - 1];
 526                         key->flags |= KEY_FLAG_CIPHER_SCHEME;
 527                 }
 528         }
 529         memcpy(key->conf.key, key_data, key_len);
 530         INIT_LIST_HEAD(&key->list);
 531
 532         return key;
 533 }
 534
 535 static void ieee80211_key_free_common(struct ieee80211_key *key)
 536 {
 537         switch (key->conf.cipher) {
 538         case WLAN_CIPHER_SUITE_CCMP:
 539         case WLAN_CIPHER_SUITE_CCMP_256:
 540                 ieee80211_aes_key_free(key->u.ccmp.tfm);
 541                 break;
 542         case WLAN_CIPHER_SUITE_AES_CMAC:
 543         case WLAN_CIPHER_SUITE_BIP_CMAC_256:
 544                 ieee80211_aes_cmac_key_free(key->u.aes_cmac.tfm);
 545                 break;
 546         case WLAN_CIPHER_SUITE_BIP_GMAC_128:
 547         case WLAN_CIPHER_SUITE_BIP_GMAC_256:
 548                 ieee80211_aes_gmac_key_free(key->u.aes_gmac.tfm);
 549                 break;
 550         case WLAN_CIPHER_SUITE_GCMP:
 551         case WLAN_CIPHER_SUITE_GCMP_256:
 552                 ieee80211_aes_gcm_key_free(key->u.gcmp.tfm);
 553                 break;
 554         }
 555         kzfree(key);
 556 }
 557
 558 static void __ieee80211_key_destroy(struct ieee80211_key *key,
 559                                     bool delay_tailroom)
 560 {
 561         if (key->local)
 562                 ieee80211_key_disable_hw_accel(key);
 563
 564         if (key->local) {
 565                 struct ieee80211_sub_if_data *sdata = key->sdata;
 566
 567                 ieee80211_debugfs_key_remove(key);
 568
 569                 if (delay_tailroom) {
 570                         /* see ieee80211_delayed_tailroom_dec */
 571                         sdata->crypto_tx_tailroom_pending_dec++;
 572                         schedule_delayed_work(&sdata->dec_tailroom_needed_wk,
 573                                               HZ/2);
 574                 } else {
 575                         decrease_tailroom_need_count(sdata, 1);
 576                 }
 577         }
 578
 579         ieee80211_key_free_common(key);
 580 }
 581
 582 static void ieee80211_key_destroy(struct ieee80211_key *key,
 583                                   bool delay_tailroom)
 584 {
 585         if (!key)
 586                 return;
 587
 588         /*
 589          * Synchronize so the TX path can no longer be using
 590          * this key before we free/remove it.
 591          */
 592         synchronize_net();
 593
 594         __ieee80211_key_destroy(key, delay_tailroom);
 595 }
 596
 597 void ieee80211_key_free_unused(struct ieee80211_key *key)
 598 {
 599         WARN_ON(key->sdata || key->local);
 600         ieee80211_key_free_common(key);
 601 }
 602
 603 int ieee80211_key_link(struct ieee80211_key *key,
 604                        struct ieee80211_sub_if_data *sdata,
 605                        struct sta_info *sta)
 606 {
 607         struct ieee80211_local *local = sdata->local;
 608         struct ieee80211_key *old_key;
 609         int idx, ret;
 610         bool pairwise;
 611
 612         pairwise = key->conf.flags & IEEE80211_KEY_FLAG_PAIRWISE;
 613         idx = key->conf.keyidx;
 614         key->local = sdata->local;
 615         key->sdata = sdata;
 616         key->sta = sta;
 617
 618         mutex_lock(&sdata->local->key_mtx);
 619
 620         if (sta && pairwise)
 621                 old_key = key_mtx_dereference(sdata->local, sta->ptk[idx]);
 622         else if (sta)
 623                 old_key = key_mtx_dereference(sdata->local, sta->gtk[idx]);
 624         else
 625                 old_key = key_mtx_dereference(sdata->local, sdata->keys[idx]);
 626
 627         increment_tailroom_need_count(sdata);
 628
 629         ieee80211_key_replace(sdata, sta, pairwise, old_key, key);
 630         ieee80211_key_destroy(old_key, true);
 631
 632         ieee80211_debugfs_key_add(key);
 633
 634         if (!local->wowlan) {
 635                 ret = ieee80211_key_enable_hw_accel(key);
 636                 if (ret)
 637                         ieee80211_key_free(key, true);
 638         } else {
 639                 ret = 0;
 640         }
 641
 642         mutex_unlock(&sdata->local->key_mtx);
 643
 644         return ret;
 645 }
 646
 647 void ieee80211_key_free(struct ieee80211_key *key, bool delay_tailroom)
 648 {
 649         if (!key)
 650                 return;
 651
 652         /*
 653          * Replace key with nothingness if it was ever used.
 654          */
 655         if (key->sdata)
 656                 ieee80211_key_replace(key->sdata, key->sta,
 657                                 key->conf.flags & IEEE80211_KEY_FLAG_PAIRWISE,
 658                                 key, NULL);
 659         ieee80211_key_destroy(key, delay_tailroom);
 660 }
 661
 662 void ieee80211_enable_keys(struct ieee80211_sub_if_data *sdata)
 663 {
 664         struct ieee80211_key *key;
 665         struct ieee80211_sub_if_data *vlan;
 666
 667         ASSERT_RTNL();
 668
 669         if (WARN_ON(!ieee80211_sdata_running(sdata)))
 670                 return;
 671
 672         mutex_lock(&sdata->local->key_mtx);
 673
 674         WARN_ON_ONCE(sdata->crypto_tx_tailroom_needed_cnt ||
 675                      sdata->crypto_tx_tailroom_pending_dec);
 676
 677         if (sdata->vif.type == NL80211_IFTYPE_AP) {
 678                 list_for_each_entry(vlan, &sdata->u.ap.vlans, u.vlan.list)
 679                         WARN_ON_ONCE(vlan->crypto_tx_tailroom_needed_cnt ||
 680                                      vlan->crypto_tx_tailroom_pending_dec);
 681         }
 682
 683         list_for_each_entry(key, &sdata->key_list, list) {
 684                 increment_tailroom_need_count(sdata);
 685                 ieee80211_key_enable_hw_accel(key);
 686         }
 687
 688         mutex_unlock(&sdata->local->key_mtx);
 689 }
 690
 691 void ieee80211_reset_crypto_tx_tailroom(struct ieee80211_sub_if_data *sdata)
 692 {
 693         struct ieee80211_sub_if_data *vlan;
 694
 695         mutex_lock(&sdata->local->key_mtx);
 696
 697         sdata->crypto_tx_tailroom_needed_cnt = 0;
 698
 699         if (sdata->vif.type == NL80211_IFTYPE_AP) {
 700                 list_for_each_entry(vlan, &sdata->u.ap.vlans, u.vlan.list)
 701                         vlan->crypto_tx_tailroom_needed_cnt = 0;
 702         }
 703
 704         mutex_unlock(&sdata->local->key_mtx);
 705 }
 706
 707 void ieee80211_iter_keys(struct ieee80211_hw *hw,
 708                          struct ieee80211_vif *vif,
 709                          void (*iter)(struct ieee80211_hw *hw,
 710                                       struct ieee80211_vif *vif,
 711                                       struct ieee80211_sta *sta,
 712                                       struct ieee80211_key_conf *key,
 713                                       void *data),
 714                          void *iter_data)
 715 {
 716         struct ieee80211_local *local = hw_to_local(hw);
 717         struct ieee80211_key *key, *tmp;
 718         struct ieee80211_sub_if_data *sdata;
 719
 720         ASSERT_RTNL();
 721
 722         mutex_lock(&local->key_mtx);
 723         if (vif) {
 724                 sdata = vif_to_sdata(vif);
 725                 list_for_each_entry_safe(key, tmp, &sdata->key_list, list)
 726                         iter(hw, &sdata->vif,
 727                              key->sta ? &key->sta->sta : NULL,
 728                              &key->conf, iter_data);
 729         } else {
 730                 list_for_each_entry(sdata, &local->interfaces, list)
 731                         list_for_each_entry_safe(key, tmp,
 732                                                  &sdata->key_list, list)
 733                                 iter(hw, &sdata->vif,
 734                                      key->sta ? &key->sta->sta : NULL,
 735                                      &key->conf, iter_data);
 736         }
 737         mutex_unlock(&local->key_mtx);
 738 }
 739 EXPORT_SYMBOL(ieee80211_iter_keys);
 740
 741 static void ieee80211_free_keys_iface(struct ieee80211_sub_if_data *sdata,
 742                                       struct list_head *keys)
 743 {
 744         struct ieee80211_key *key, *tmp;
 745
 746         decrease_tailroom_need_count(sdata,
 747                                      sdata->crypto_tx_tailroom_pending_dec);
 748         sdata->crypto_tx_tailroom_pending_dec = 0;
 749
 750         ieee80211_debugfs_key_remove_mgmt_default(sdata);
 751
 752         list_for_each_entry_safe(key, tmp, &sdata->key_list, list) {
 753                 ieee80211_key_replace(key->sdata, key->sta,
 754                                 key->conf.flags & IEEE80211_KEY_FLAG_PAIRWISE,
 755                                 key, NULL);
 756                 list_add_tail(&key->list, keys);
 757         }
 758
 759         ieee80211_debugfs_key_update_default(sdata);
 760 }
 761
 762 void ieee80211_free_keys(struct ieee80211_sub_if_data *sdata,
 763                          bool force_synchronize)
 764 {
 765         struct ieee80211_local *local = sdata->local;
 766         struct ieee80211_sub_if_data *vlan;
 767         struct ieee80211_sub_if_data *master;
 768         struct ieee80211_key *key, *tmp;
 769         LIST_HEAD(keys);
 770
 771         cancel_delayed_work_sync(&sdata->dec_tailroom_needed_wk);
 772
 773         mutex_lock(&local->key_mtx);
 774
 775         ieee80211_free_keys_iface(sdata, &keys);
 776
 777         if (sdata->vif.type == NL80211_IFTYPE_AP) {
 778                 list_for_each_entry(vlan, &sdata->u.ap.vlans, u.vlan.list)
 779                         ieee80211_free_keys_iface(vlan, &keys);
 780         }
 781
 782         if (!list_empty(&keys) || force_synchronize)
 783                 synchronize_net();
 784         list_for_each_entry_safe(key, tmp, &keys, list)
 785                 __ieee80211_key_destroy(key, false);
 786
 787         if (sdata->vif.type == NL80211_IFTYPE_AP_VLAN) {
 788                 if (sdata->bss) {
 789                         master = container_of(sdata->bss,
 790                                               struct ieee80211_sub_if_data,
 791                                               u.ap);
 792
 793                         WARN_ON_ONCE(sdata->crypto_tx_tailroom_needed_cnt !=
 794                                      master->crypto_tx_tailroom_needed_cnt);
 795                 }
 796         } else {
 797                 WARN_ON_ONCE(sdata->crypto_tx_tailroom_needed_cnt ||
 798                              sdata->crypto_tx_tailroom_pending_dec);
 799         }
 800
 801         if (sdata->vif.type == NL80211_IFTYPE_AP) {
 802                 list_for_each_entry(vlan, &sdata->u.ap.vlans, u.vlan.list)
 803                         WARN_ON_ONCE(vlan->crypto_tx_tailroom_needed_cnt ||
 804                                      vlan->crypto_tx_tailroom_pending_dec);
 805         }
 806
 807         mutex_unlock(&local->key_mtx);
 808 }
 809
 810 void ieee80211_free_sta_keys(struct ieee80211_local *local,
 811                              struct sta_info *sta)
 812 {
 813         struct ieee80211_key *key;
 814         int i;
 815
 816         mutex_lock(&local->key_mtx);
 817         for (i = 0; i < ARRAY_SIZE(sta->gtk); i++) {
 818                 key = key_mtx_dereference(local, sta->gtk[i]);
 819                 if (!key)
 820                         continue;
 821                 ieee80211_key_replace(key->sdata, key->sta,
 822                                 key->conf.flags & IEEE80211_KEY_FLAG_PAIRWISE,
 823                                 key, NULL);
 824                 __ieee80211_key_destroy(key, true);
 825         }
 826
 827         for (i = 0; i < NUM_DEFAULT_KEYS; i++) {
 828                 key = key_mtx_dereference(local, sta->ptk[i]);
 829                 if (!key)
 830                         continue;
 831                 ieee80211_key_replace(key->sdata, key->sta,
 832                                 key->conf.flags & IEEE80211_KEY_FLAG_PAIRWISE,
 833                                 key, NULL);
 834                 __ieee80211_key_destroy(key, true);
 835         }
 836
 837         mutex_unlock(&local->key_mtx);
 838 }
 839
 840 void ieee80211_delayed_tailroom_dec(struct work_struct *wk)
 841 {
 842         struct ieee80211_sub_if_data *sdata;
 843
 844         sdata = container_of(wk, struct ieee80211_sub_if_data,
 845                              dec_tailroom_needed_wk.work);
 846
 847         /*
 848          * The reason for the delayed tailroom needed decrementing is to
 849          * make roaming faster: during roaming, all keys are first deleted
 850          * and then new keys are installed. The first new key causes the
 851          * crypto_tx_tailroom_needed_cnt to go from 0 to 1, which invokes
 852          * the cost of synchronize_net() (which can be slow). Avoid this
 853          * by deferring the crypto_tx_tailroom_needed_cnt decrementing on
 854          * key removal for a while, so if we roam the value is larger than
 855          * zero and no 0->1 transition happens.
 856          *
 857          * The cost is that if the AP switching was from an AP with keys
 858          * to one without, we still allocate tailroom while it would no
 859          * longer be needed. However, in the typical (fast) roaming case
 860          * within an ESS this usually won't happen.
 861          */
 862
 863         mutex_lock(&sdata->local->key_mtx);
 864         decrease_tailroom_need_count(sdata,
 865                                      sdata->crypto_tx_tailroom_pending_dec);
 866         sdata->crypto_tx_tailroom_pending_dec = 0;
 867         mutex_unlock(&sdata->local->key_mtx);
 868 }
 869
 870 void ieee80211_gtk_rekey_notify(struct ieee80211_vif *vif, const u8 *bssid,
 871                                 const u8 *replay_ctr, gfp_t gfp)
 872 {
 873         struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
 874
 875         trace_api_gtk_rekey_notify(sdata, bssid, replay_ctr);
 876
 877         cfg80211_gtk_rekey_notify(sdata->dev, bssid, replay_ctr, gfp);
 878 }
 879 EXPORT_SYMBOL_GPL(ieee80211_gtk_rekey_notify);
 880
 881 void ieee80211_get_key_tx_seq(struct ieee80211_key_conf *keyconf,
 882                               struct ieee80211_key_seq *seq)
 883 {
 884         struct ieee80211_key *key;
 885         u64 pn64;
 886
 887         if (WARN_ON(!(keyconf->flags & IEEE80211_KEY_FLAG_GENERATE_IV)))
 888                 return;
 889
 890         key = container_of(keyconf, struct ieee80211_key, conf);
 891
 892         switch (key->conf.cipher) {
 893         case WLAN_CIPHER_SUITE_TKIP:
 894                 seq->tkip.iv32 = key->u.tkip.tx.iv32;
 895                 seq->tkip.iv16 = key->u.tkip.tx.iv16;
 896                 break;
 897         case WLAN_CIPHER_SUITE_CCMP:
 898         case WLAN_CIPHER_SUITE_CCMP_256:
 899         case WLAN_CIPHER_SUITE_AES_CMAC:
 900         case WLAN_CIPHER_SUITE_BIP_CMAC_256:
 901                 BUILD_BUG_ON(offsetof(typeof(*seq), ccmp) !=
 902                              offsetof(typeof(*seq), aes_cmac));
 903         case WLAN_CIPHER_SUITE_BIP_GMAC_128:
 904         case WLAN_CIPHER_SUITE_BIP_GMAC_256:
 905                 BUILD_BUG_ON(offsetof(typeof(*seq), ccmp) !=
 906                              offsetof(typeof(*seq), aes_gmac));
 907         case WLAN_CIPHER_SUITE_GCMP:
 908         case WLAN_CIPHER_SUITE_GCMP_256:
 909                 BUILD_BUG_ON(offsetof(typeof(*seq), ccmp) !=
 910                              offsetof(typeof(*seq), gcmp));
 911                 pn64 = atomic64_read(&key->conf.tx_pn);
 912                 seq->ccmp.pn[5] = pn64;
 913                 seq->ccmp.pn[4] = pn64 >> 8;
 914                 seq->ccmp.pn[3] = pn64 >> 16;
 915                 seq->ccmp.pn[2] = pn64 >> 24;
 916                 seq->ccmp.pn[1] = pn64 >> 32;
 917                 seq->ccmp.pn[0] = pn64 >> 40;
 918                 break;
 919         default:
 920                 WARN_ON(1);
 921         }
 922 }
 923 EXPORT_SYMBOL(ieee80211_get_key_tx_seq);
 924
 925 void ieee80211_get_key_rx_seq(struct ieee80211_key_conf *keyconf,
 926                               int tid, struct ieee80211_key_seq *seq)
 927 {
 928         struct ieee80211_key *key;
 929         const u8 *pn;
 930
 931         key = container_of(keyconf, struct ieee80211_key, conf);
 932
 933         switch (key->conf.cipher) {
 934         case WLAN_CIPHER_SUITE_TKIP:
 935                 if (WARN_ON(tid < 0 || tid >= IEEE80211_NUM_TIDS))
 936                         return;
 937                 seq->tkip.iv32 = key->u.tkip.rx[tid].iv32;
 938                 seq->tkip.iv16 = key->u.tkip.rx[tid].iv16;
 939                 break;
 940         case WLAN_CIPHER_SUITE_CCMP:
 941         case WLAN_CIPHER_SUITE_CCMP_256:
 942                 if (WARN_ON(tid < -1 || tid >= IEEE80211_NUM_TIDS))
 943                         return;
 944                 if (tid < 0)
 945                         pn = key->u.ccmp.rx_pn[IEEE80211_NUM_TIDS];
 946                 else
 947                         pn = key->u.ccmp.rx_pn[tid];
 948                 memcpy(seq->ccmp.pn, pn, IEEE80211_CCMP_PN_LEN);
 949                 break;
 950         case WLAN_CIPHER_SUITE_AES_CMAC:
 951         case WLAN_CIPHER_SUITE_BIP_CMAC_256:
 952                 if (WARN_ON(tid != 0))
 953                         return;
 954                 pn = key->u.aes_cmac.rx_pn;
 955                 memcpy(seq->aes_cmac.pn, pn, IEEE80211_CMAC_PN_LEN);
 956                 break;
 957         case WLAN_CIPHER_SUITE_BIP_GMAC_128:
 958         case WLAN_CIPHER_SUITE_BIP_GMAC_256:
 959                 if (WARN_ON(tid != 0))
 960                         return;
 961                 pn = key->u.aes_gmac.rx_pn;
 962                 memcpy(seq->aes_gmac.pn, pn, IEEE80211_GMAC_PN_LEN);
 963                 break;
 964         case WLAN_CIPHER_SUITE_GCMP:
 965         case WLAN_CIPHER_SUITE_GCMP_256:
 966                 if (WARN_ON(tid < -1 || tid >= IEEE80211_NUM_TIDS))
 967                         return;
 968                 if (tid < 0)
 969                         pn = key->u.gcmp.rx_pn[IEEE80211_NUM_TIDS];
 970                 else
 971                         pn = key->u.gcmp.rx_pn[tid];
 972                 memcpy(seq->gcmp.pn, pn, IEEE80211_GCMP_PN_LEN);
 973                 break;
 974         }
 975 }
 976 EXPORT_SYMBOL(ieee80211_get_key_rx_seq);
 977
 978 void ieee80211_set_key_tx_seq(struct ieee80211_key_conf *keyconf,
 979                               struct ieee80211_key_seq *seq)
 980 {
 981         struct ieee80211_key *key;
 982         u64 pn64;
 983
 984         key = container_of(keyconf, struct ieee80211_key, conf);
 985
 986         switch (key->conf.cipher) {
 987         case WLAN_CIPHER_SUITE_TKIP:
 988                 key->u.tkip.tx.iv32 = seq->tkip.iv32;
 989                 key->u.tkip.tx.iv16 = seq->tkip.iv16;
 990                 break;
 991         case WLAN_CIPHER_SUITE_CCMP:
 992         case WLAN_CIPHER_SUITE_CCMP_256:
 993         case WLAN_CIPHER_SUITE_AES_CMAC:
 994         case WLAN_CIPHER_SUITE_BIP_CMAC_256:
 995                 BUILD_BUG_ON(offsetof(typeof(*seq), ccmp) !=
 996                              offsetof(typeof(*seq), aes_cmac));
 997         case WLAN_CIPHER_SUITE_BIP_GMAC_128:
 998         case WLAN_CIPHER_SUITE_BIP_GMAC_256:
 999                 BUILD_BUG_ON(offsetof(typeof(*seq), ccmp) !=
1000                              offsetof(typeof(*seq), aes_gmac));
1001         case WLAN_CIPHER_SUITE_GCMP:
1002         case WLAN_CIPHER_SUITE_GCMP_256:
1003                 BUILD_BUG_ON(offsetof(typeof(*seq), ccmp) !=
1004                              offsetof(typeof(*seq), gcmp));
1005                 pn64 = (u64)seq->ccmp.pn[5] |
1006                        ((u64)seq->ccmp.pn[4] << 8) |
1007                        ((u64)seq->ccmp.pn[3] << 16) |
1008                        ((u64)seq->ccmp.pn[2] << 24) |
1009                        ((u64)seq->ccmp.pn[1] << 32) |
1010                        ((u64)seq->ccmp.pn[0] << 40);
1011                 atomic64_set(&key->conf.tx_pn, pn64);
1012                 break;
1013         default:
1014                 WARN_ON(1);
1015                 break;
1016         }
1017 }
1018 EXPORT_SYMBOL_GPL(ieee80211_set_key_tx_seq);
1019
1020 void ieee80211_set_key_rx_seq(struct ieee80211_key_conf *keyconf,
1021                               int tid, struct ieee80211_key_seq *seq)
1022 {
1023         struct ieee80211_key *key;
1024         u8 *pn;
1025
1026         key = container_of(keyconf, struct ieee80211_key, conf);
1027
1028         switch (key->conf.cipher) {
1029         case WLAN_CIPHER_SUITE_TKIP:
1030                 if (WARN_ON(tid < 0 || tid >= IEEE80211_NUM_TIDS))
1031                         return;
1032                 key->u.tkip.rx[tid].iv32 = seq->tkip.iv32;
1033                 key->u.tkip.rx[tid].iv16 = seq->tkip.iv16;
1034                 break;
1035         case WLAN_CIPHER_SUITE_CCMP:
1036         case WLAN_CIPHER_SUITE_CCMP_256:
1037                 if (WARN_ON(tid < -1 || tid >= IEEE80211_NUM_TIDS))
1038                         return;
1039                 if (tid < 0)
1040                         pn = key->u.ccmp.rx_pn[IEEE80211_NUM_TIDS];
1041                 else
1042                         pn = key->u.ccmp.rx_pn[tid];
1043                 memcpy(pn, seq->ccmp.pn, IEEE80211_CCMP_PN_LEN);
1044                 break;
1045         case WLAN_CIPHER_SUITE_AES_CMAC:
1046         case WLAN_CIPHER_SUITE_BIP_CMAC_256:
1047                 if (WARN_ON(tid != 0))
1048                         return;
1049                 pn = key->u.aes_cmac.rx_pn;
1050                 memcpy(pn, seq->aes_cmac.pn, IEEE80211_CMAC_PN_LEN);
1051                 break;
1052         case WLAN_CIPHER_SUITE_BIP_GMAC_128:
1053         case WLAN_CIPHER_SUITE_BIP_GMAC_256:
1054                 if (WARN_ON(tid != 0))
1055                         return;
1056                 pn = key->u.aes_gmac.rx_pn;
1057                 memcpy(pn, seq->aes_gmac.pn, IEEE80211_GMAC_PN_LEN);
1058                 break;
1059         case WLAN_CIPHER_SUITE_GCMP:
1060         case WLAN_CIPHER_SUITE_GCMP_256:
1061                 if (WARN_ON(tid < -1 || tid >= IEEE80211_NUM_TIDS))
1062                         return;
1063                 if (tid < 0)
1064                         pn = key->u.gcmp.rx_pn[IEEE80211_NUM_TIDS];
1065                 else
1066                         pn = key->u.gcmp.rx_pn[tid];
1067                 memcpy(pn, seq->gcmp.pn, IEEE80211_GCMP_PN_LEN);
1068                 break;
1069         default:
1070                 WARN_ON(1);
1071                 break;
1072         }
1073 }
1074 EXPORT_SYMBOL_GPL(ieee80211_set_key_rx_seq);
1075
1076 void ieee80211_remove_key(struct ieee80211_key_conf *keyconf)
1077 {
1078         struct ieee80211_key *key;
1079
1080         key = container_of(keyconf, struct ieee80211_key, conf);
1081
1082         assert_key_lock(key->local);
1083
1084         /*
1085          * if key was uploaded, we assume the driver will/has remove(d)
1086          * it, so adjust bookkeeping accordingly
1087          */
1088         if (key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE) {
1089                 key->flags &= ~KEY_FLAG_UPLOADED_TO_HARDWARE;
1090
1091                 if (!((key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_MMIC) ||
1092                       (key->conf.flags & IEEE80211_KEY_FLAG_RESERVE_TAILROOM)))
1093                         increment_tailroom_need_count(key->sdata);
1094         }
1095
1096         ieee80211_key_free(key, false);
1097 }
1098 EXPORT_SYMBOL_GPL(ieee80211_remove_key);
1099
1100 struct ieee80211_key_conf *
1101 ieee80211_gtk_rekey_add(struct ieee80211_vif *vif,
1102                         struct ieee80211_key_conf *keyconf)
1103 {
1104         struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
1105         struct ieee80211_local *local = sdata->local;
1106         struct ieee80211_key *key;
1107         int err;
1108
1109         if (WARN_ON(!local->wowlan))
1110                 return ERR_PTR(-EINVAL);
1111
1112         if (WARN_ON(vif->type != NL80211_IFTYPE_STATION))
1113                 return ERR_PTR(-EINVAL);
1114
1115         key = ieee80211_key_alloc(keyconf->cipher, keyconf->keyidx,
1116                                   keyconf->keylen, keyconf->key,
1117                                   0, NULL, NULL);
1118         if (IS_ERR(key))
1119                 return ERR_CAST(key);
1120
1121         if (sdata->u.mgd.mfp != IEEE80211_MFP_DISABLED)
1122                 key->conf.flags |= IEEE80211_KEY_FLAG_RX_MGMT;
1123
1124         err = ieee80211_key_link(key, sdata, NULL);
1125         if (err)
1126                 return ERR_PTR(err);
1127
1128         return &key->conf;
1129 }
1130 EXPORT_SYMBOL_GPL(ieee80211_gtk_rekey_add);