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         /* crypto_tx_tailroom_needed_cnt is protected by this */
  70         assert_key_lock(sdata->local);
  71
  72         rcu_read_lock();
  73
  74         list_for_each_entry_rcu(vlan, &sdata->u.ap.vlans, u.vlan.list)
  75                 vlan->crypto_tx_tailroom_needed_cnt += delta;
  76
  77         rcu_read_unlock();
  78 }
  79
  80 static void increment_tailroom_need_count(struct ieee80211_sub_if_data *sdata)
  81 {
  82         /*
  83          * When this count is zero, SKB resizing for allocating tailroom
  84          * for IV or MMIC is skipped. But, this check has created two race
  85          * cases in xmit path while transiting from zero count to one:
  86          *
  87          * 1. SKB resize was skipped because no key was added but just before
  88          * the xmit key is added and SW encryption kicks off.
  89          *
  90          * 2. SKB resize was skipped because all the keys were hw planted but
  91          * just before xmit one of the key is deleted and SW encryption kicks
  92          * off.
  93          *
  94          * In both the above case SW encryption will find not enough space for
  95          * tailroom and exits with WARN_ON. (See WARN_ONs at wpa.c)
  96          *
  97          * Solution has been explained at
  98          * http://mid.gmane.org/1308590980.4322.19.camel@jlt3.sipsolutions.net
  99          */
 100
 101         assert_key_lock(sdata->local);
 102
 103         update_vlan_tailroom_need_count(sdata, 1);
 104
 105         if (!sdata->crypto_tx_tailroom_needed_cnt++) {
 106                 /*
 107                  * Flush all XMIT packets currently using HW encryption or no
 108                  * encryption at all if the count transition is from 0 -> 1.
 109                  */
 110                 synchronize_net();
 111         }
 112 }
 113
 114 static void decrease_tailroom_need_count(struct ieee80211_sub_if_data *sdata,
 115                                          int delta)
 116 {
 117         assert_key_lock(sdata->local);
 118
 119         WARN_ON_ONCE(sdata->crypto_tx_tailroom_needed_cnt < delta);
 120
 121         update_vlan_tailroom_need_count(sdata, -delta);
 122         sdata->crypto_tx_tailroom_needed_cnt -= delta;
 123 }
 124
 125 static int ieee80211_key_enable_hw_accel(struct ieee80211_key *key)
 126 {
 127         struct ieee80211_sub_if_data *sdata;
 128         struct sta_info *sta;
 129         int ret = -EOPNOTSUPP;
 130
 131         might_sleep();
 132
 133         if (key->flags & KEY_FLAG_TAINTED) {
 134                 /* If we get here, it's during resume and the key is
 135                  * tainted so shouldn't be used/programmed any more.
 136                  * However, its flags may still indicate that it was
 137                  * programmed into the device (since we're in resume)
 138                  * so clear that flag now to avoid trying to remove
 139                  * it again later.
 140                  */
 141                 key->flags &= ~KEY_FLAG_UPLOADED_TO_HARDWARE;
 142                 return -EINVAL;
 143         }
 144
 145         if (!key->local->ops->set_key)
 146                 goto out_unsupported;
 147
 148         assert_key_lock(key->local);
 149
 150         sta = key->sta;
 151
 152         /*
 153          * If this is a per-STA GTK, check if it
 154          * is supported; if not, return.
 155          */
 156         if (sta && !(key->conf.flags & IEEE80211_KEY_FLAG_PAIRWISE) &&
 157             !ieee80211_hw_check(&key->local->hw, SUPPORTS_PER_STA_GTK))
 158                 goto out_unsupported;
 159
 160         if (sta && !sta->uploaded)
 161                 goto out_unsupported;
 162
 163         sdata = key->sdata;
 164         if (sdata->vif.type == NL80211_IFTYPE_AP_VLAN) {
 165                 /*
 166                  * The driver doesn't know anything about VLAN interfaces.
 167                  * Hence, don't send GTKs for VLAN interfaces to the driver.
 168                  */
 169                 if (!(key->conf.flags & IEEE80211_KEY_FLAG_PAIRWISE))
 170                         goto out_unsupported;
 171         }
 172
 173         ret = drv_set_key(key->local, SET_KEY, sdata,
 174                           sta ? &sta->sta : NULL, &key->conf);
 175
 176         if (!ret) {
 177                 key->flags |= KEY_FLAG_UPLOADED_TO_HARDWARE;
 178
 179                 if (!((key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_MMIC) ||
 180                       (key->conf.flags & IEEE80211_KEY_FLAG_RESERVE_TAILROOM)))
 181                         decrease_tailroom_need_count(sdata, 1);
 182
 183                 WARN_ON((key->conf.flags & IEEE80211_KEY_FLAG_PUT_IV_SPACE) &&
 184                         (key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_IV));
 185
 186                 return 0;
 187         }
 188
 189         if (ret != -ENOSPC && ret != -EOPNOTSUPP && ret != 1)
 190                 sdata_err(sdata,
 191                           "failed to set key (%d, %pM) to hardware (%d)\n",
 192                           key->conf.keyidx,
 193                           sta ? sta->sta.addr : bcast_addr, ret);
 194
 195  out_unsupported:
 196         switch (key->conf.cipher) {
 197         case WLAN_CIPHER_SUITE_WEP40:
 198         case WLAN_CIPHER_SUITE_WEP104:
 199         case WLAN_CIPHER_SUITE_TKIP:
 200         case WLAN_CIPHER_SUITE_CCMP:
 201         case WLAN_CIPHER_SUITE_CCMP_256:
 202         case WLAN_CIPHER_SUITE_AES_CMAC:
 203         case WLAN_CIPHER_SUITE_BIP_CMAC_256:
 204         case WLAN_CIPHER_SUITE_BIP_GMAC_128:
 205         case WLAN_CIPHER_SUITE_BIP_GMAC_256:
 206         case WLAN_CIPHER_SUITE_GCMP:
 207         case WLAN_CIPHER_SUITE_GCMP_256:
 208                 /* all of these we can do in software - if driver can */
 209                 if (ret == 1)
 210                         return 0;
 211                 if (ieee80211_hw_check(&key->local->hw, SW_CRYPTO_CONTROL))
 212                         return -EINVAL;
 213                 return 0;
 214         default:
 215                 return -EINVAL;
 216         }
 217 }
 218
 219 static void ieee80211_key_disable_hw_accel(struct ieee80211_key *key)
 220 {
 221         struct ieee80211_sub_if_data *sdata;
 222         struct sta_info *sta;
 223         int ret;
 224
 225         might_sleep();
 226
 227         if (!key || !key->local->ops->set_key)
 228                 return;
 229
 230         assert_key_lock(key->local);
 231
 232         if (!(key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE))
 233                 return;
 234
 235         sta = key->sta;
 236         sdata = key->sdata;
 237
 238         if (!((key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_MMIC) ||
 239               (key->conf.flags & IEEE80211_KEY_FLAG_RESERVE_TAILROOM)))
 240                 increment_tailroom_need_count(sdata);
 241
 242         ret = drv_set_key(key->local, DISABLE_KEY, sdata,
 243                           sta ? &sta->sta : NULL, &key->conf);
 244
 245         if (ret)
 246                 sdata_err(sdata,
 247                           "failed to remove key (%d, %pM) from hardware (%d)\n",
 248                           key->conf.keyidx,
 249                           sta ? sta->sta.addr : bcast_addr, ret);
 250
 251         key->flags &= ~KEY_FLAG_UPLOADED_TO_HARDWARE;
 252 }
 253
 254 static void __ieee80211_set_default_key(struct ieee80211_sub_if_data *sdata,
 255                                         int idx, bool uni, bool multi)
 256 {
 257         struct ieee80211_key *key = NULL;
 258
 259         assert_key_lock(sdata->local);
 260
 261         if (idx >= 0 && idx < NUM_DEFAULT_KEYS)
 262                 key = key_mtx_dereference(sdata->local, sdata->keys[idx]);
 263
 264         if (uni) {
 265                 rcu_assign_pointer(sdata->default_unicast_key, key);
 266                 ieee80211_check_fast_xmit_iface(sdata);
 267                 drv_set_default_unicast_key(sdata->local, sdata, idx);
 268         }
 269
 270         if (multi)
 271                 rcu_assign_pointer(sdata->default_multicast_key, key);
 272
 273         ieee80211_debugfs_key_update_default(sdata);
 274 }
 275
 276 void ieee80211_set_default_key(struct ieee80211_sub_if_data *sdata, int idx,
 277                                bool uni, bool multi)
 278 {
 279         mutex_lock(&sdata->local->key_mtx);
 280         __ieee80211_set_default_key(sdata, idx, uni, multi);
 281         mutex_unlock(&sdata->local->key_mtx);
 282 }
 283
 284 static void
 285 __ieee80211_set_default_mgmt_key(struct ieee80211_sub_if_data *sdata, int idx)
 286 {
 287         struct ieee80211_key *key = NULL;
 288
 289         assert_key_lock(sdata->local);
 290
 291         if (idx >= NUM_DEFAULT_KEYS &&
 292             idx < NUM_DEFAULT_KEYS + NUM_DEFAULT_MGMT_KEYS)
 293                 key = key_mtx_dereference(sdata->local, sdata->keys[idx]);
 294
 295         rcu_assign_pointer(sdata->default_mgmt_key, key);
 296
 297         ieee80211_debugfs_key_update_default(sdata);
 298 }
 299
 300 void ieee80211_set_default_mgmt_key(struct ieee80211_sub_if_data *sdata,
 301                                     int idx)
 302 {
 303         mutex_lock(&sdata->local->key_mtx);
 304         __ieee80211_set_default_mgmt_key(sdata, idx);
 305         mutex_unlock(&sdata->local->key_mtx);
 306 }
 307
 308
 309 static void ieee80211_key_replace(struct ieee80211_sub_if_data *sdata,
 310                                   struct sta_info *sta,
 311                                   bool pairwise,
 312                                   struct ieee80211_key *old,
 313                                   struct ieee80211_key *new)
 314 {
 315         int idx;
 316         bool defunikey, defmultikey, defmgmtkey;
 317
 318         /* caller must provide at least one old/new */
 319         if (WARN_ON(!new && !old))
 320                 return;
 321
 322         if (new)
 323                 list_add_tail(&new->list, &sdata->key_list);
 324
 325         WARN_ON(new && old && new->conf.keyidx != old->conf.keyidx);
 326
 327         if (old)
 328                 idx = old->conf.keyidx;
 329         else
 330                 idx = new->conf.keyidx;
 331
 332         if (sta) {
 333                 if (pairwise) {
 334                         rcu_assign_pointer(sta->ptk[idx], new);
 335                         sta->ptk_idx = idx;
 336                         ieee80211_check_fast_xmit(sta);
 337                 } else {
 338                         rcu_assign_pointer(sta->gtk[idx], new);
 339                         sta->gtk_idx = idx;
 340                 }
 341         } else {
 342                 defunikey = old &&
 343                         old == key_mtx_dereference(sdata->local,
 344                                                 sdata->default_unicast_key);
 345                 defmultikey = old &&
 346                         old == key_mtx_dereference(sdata->local,
 347                                                 sdata->default_multicast_key);
 348                 defmgmtkey = old &&
 349                         old == key_mtx_dereference(sdata->local,
 350                                                 sdata->default_mgmt_key);
 351
 352                 if (defunikey && !new)
 353                         __ieee80211_set_default_key(sdata, -1, true, false);
 354                 if (defmultikey && !new)
 355                         __ieee80211_set_default_key(sdata, -1, false, true);
 356                 if (defmgmtkey && !new)
 357                         __ieee80211_set_default_mgmt_key(sdata, -1);
 358
 359                 rcu_assign_pointer(sdata->keys[idx], new);
 360                 if (defunikey && new)
 361                         __ieee80211_set_default_key(sdata, new->conf.keyidx,
 362                                                     true, false);
 363                 if (defmultikey && new)
 364                         __ieee80211_set_default_key(sdata, new->conf.keyidx,
 365                                                     false, true);
 366                 if (defmgmtkey && new)
 367                         __ieee80211_set_default_mgmt_key(sdata,
 368                                                          new->conf.keyidx);
 369         }
 370
 371         if (old)
 372                 list_del(&old->list);
 373 }
 374
 375 struct ieee80211_key *
 376 ieee80211_key_alloc(u32 cipher, int idx, size_t key_len,
 377                     const u8 *key_data,
 378                     size_t seq_len, const u8 *seq,
 379                     const struct ieee80211_cipher_scheme *cs)
 380 {
 381         struct ieee80211_key *key;
 382         int i, j, err;
 383
 384         if (WARN_ON(idx < 0 || idx >= NUM_DEFAULT_KEYS + NUM_DEFAULT_MGMT_KEYS))
 385                 return ERR_PTR(-EINVAL);
 386
 387         key = kzalloc(sizeof(struct ieee80211_key) + key_len, GFP_KERNEL);
 388         if (!key)
 389                 return ERR_PTR(-ENOMEM);
 390
 391         /*
 392          * Default to software encryption; we'll later upload the
 393          * key to the hardware if possible.
 394          */
 395         key->conf.flags = 0;
 396         key->flags = 0;
 397
 398         key->conf.cipher = cipher;
 399         key->conf.keyidx = idx;
 400         key->conf.keylen = key_len;
 401         switch (cipher) {
 402         case WLAN_CIPHER_SUITE_WEP40:
 403         case WLAN_CIPHER_SUITE_WEP104:
 404                 key->conf.iv_len = IEEE80211_WEP_IV_LEN;
 405                 key->conf.icv_len = IEEE80211_WEP_ICV_LEN;
 406                 break;
 407         case WLAN_CIPHER_SUITE_TKIP:
 408                 key->conf.iv_len = IEEE80211_TKIP_IV_LEN;
 409                 key->conf.icv_len = IEEE80211_TKIP_ICV_LEN;
 410                 if (seq) {
 411                         for (i = 0; i < IEEE80211_NUM_TIDS; i++) {
 412                                 key->u.tkip.rx[i].iv32 =
 413                                         get_unaligned_le32(&seq[2]);
 414                                 key->u.tkip.rx[i].iv16 =
 415                                         get_unaligned_le16(seq);
 416                         }
 417                 }
 418                 spin_lock_init(&key->u.tkip.txlock);
 419                 break;
 420         case WLAN_CIPHER_SUITE_CCMP:
 421                 key->conf.iv_len = IEEE80211_CCMP_HDR_LEN;
 422                 key->conf.icv_len = IEEE80211_CCMP_MIC_LEN;
 423                 if (seq) {
 424                         for (i = 0; i < IEEE80211_NUM_TIDS + 1; i++)
 425                                 for (j = 0; j < IEEE80211_CCMP_PN_LEN; j++)
 426                                         key->u.ccmp.rx_pn[i][j] =
 427                                                 seq[IEEE80211_CCMP_PN_LEN - j - 1];
 428                 }
 429                 /*
 430                  * Initialize AES key state here as an optimization so that
 431                  * it does not need to be initialized for every packet.
 432                  */
 433                 key->u.ccmp.tfm = ieee80211_aes_key_setup_encrypt(
 434                         key_data, key_len, IEEE80211_CCMP_MIC_LEN);
 435                 if (IS_ERR(key->u.ccmp.tfm)) {
 436                         err = PTR_ERR(key->u.ccmp.tfm);
 437                         kfree(key);
 438                         return ERR_PTR(err);
 439                 }
 440                 break;
 441         case WLAN_CIPHER_SUITE_CCMP_256:
 442                 key->conf.iv_len = IEEE80211_CCMP_256_HDR_LEN;
 443                 key->conf.icv_len = IEEE80211_CCMP_256_MIC_LEN;
 444                 for (i = 0; seq && i < IEEE80211_NUM_TIDS + 1; i++)
 445                         for (j = 0; j < IEEE80211_CCMP_256_PN_LEN; j++)
 446                                 key->u.ccmp.rx_pn[i][j] =
 447                                         seq[IEEE80211_CCMP_256_PN_LEN - j - 1];
 448                 /* Initialize AES key state here as an optimization so that
 449                  * it does not need to be initialized for every packet.
 450                  */
 451                 key->u.ccmp.tfm = ieee80211_aes_key_setup_encrypt(
 452                         key_data, key_len, IEEE80211_CCMP_256_MIC_LEN);
 453                 if (IS_ERR(key->u.ccmp.tfm)) {
 454                         err = PTR_ERR(key->u.ccmp.tfm);
 455                         kfree(key);
 456                         return ERR_PTR(err);
 457                 }
 458                 break;
 459         case WLAN_CIPHER_SUITE_AES_CMAC:
 460         case WLAN_CIPHER_SUITE_BIP_CMAC_256:
 461                 key->conf.iv_len = 0;
 462                 if (cipher == WLAN_CIPHER_SUITE_AES_CMAC)
 463                         key->conf.icv_len = sizeof(struct ieee80211_mmie);
 464                 else
 465                         key->conf.icv_len = sizeof(struct ieee80211_mmie_16);
 466                 if (seq)
 467                         for (j = 0; j < IEEE80211_CMAC_PN_LEN; j++)
 468                                 key->u.aes_cmac.rx_pn[j] =
 469                                         seq[IEEE80211_CMAC_PN_LEN - j - 1];
 470                 /*
 471                  * Initialize AES key state here as an optimization so that
 472                  * it does not need to be initialized for every packet.
 473                  */
 474                 key->u.aes_cmac.tfm =
 475                         ieee80211_aes_cmac_key_setup(key_data, key_len);
 476                 if (IS_ERR(key->u.aes_cmac.tfm)) {
 477                         err = PTR_ERR(key->u.aes_cmac.tfm);
 478                         kfree(key);
 479                         return ERR_PTR(err);
 480                 }
 481                 break;
 482         case WLAN_CIPHER_SUITE_BIP_GMAC_128:
 483         case WLAN_CIPHER_SUITE_BIP_GMAC_256:
 484                 key->conf.iv_len = 0;
 485                 key->conf.icv_len = sizeof(struct ieee80211_mmie_16);
 486                 if (seq)
 487                         for (j = 0; j < IEEE80211_GMAC_PN_LEN; j++)
 488                                 key->u.aes_gmac.rx_pn[j] =
 489                                         seq[IEEE80211_GMAC_PN_LEN - j - 1];
 490                 /* Initialize AES key state here as an optimization so that
 491                  * it does not need to be initialized for every packet.
 492                  */
 493                 key->u.aes_gmac.tfm =
 494                         ieee80211_aes_gmac_key_setup(key_data, key_len);
 495                 if (IS_ERR(key->u.aes_gmac.tfm)) {
 496                         err = PTR_ERR(key->u.aes_gmac.tfm);
 497                         kfree(key);
 498                         return ERR_PTR(err);
 499                 }
 500                 break;
 501         case WLAN_CIPHER_SUITE_GCMP:
 502         case WLAN_CIPHER_SUITE_GCMP_256:
 503                 key->conf.iv_len = IEEE80211_GCMP_HDR_LEN;
 504                 key->conf.icv_len = IEEE80211_GCMP_MIC_LEN;
 505                 for (i = 0; seq && i < IEEE80211_NUM_TIDS + 1; i++)
 506                         for (j = 0; j < IEEE80211_GCMP_PN_LEN; j++)
 507                                 key->u.gcmp.rx_pn[i][j] =
 508                                         seq[IEEE80211_GCMP_PN_LEN - j - 1];
 509                 /* Initialize AES key state here as an optimization so that
 510                  * it does not need to be initialized for every packet.
 511                  */
 512                 key->u.gcmp.tfm = ieee80211_aes_gcm_key_setup_encrypt(key_data,
 513                                                                       key_len);
 514                 if (IS_ERR(key->u.gcmp.tfm)) {
 515                         err = PTR_ERR(key->u.gcmp.tfm);
 516                         kfree(key);
 517                         return ERR_PTR(err);
 518                 }
 519                 break;
 520         default:
 521                 if (cs) {
 522                         if (seq_len && seq_len != cs->pn_len) {
 523                                 kfree(key);
 524                                 return ERR_PTR(-EINVAL);
 525                         }
 526
 527                         key->conf.iv_len = cs->hdr_len;
 528                         key->conf.icv_len = cs->mic_len;
 529                         for (i = 0; i < IEEE80211_NUM_TIDS + 1; i++)
 530                                 for (j = 0; j < seq_len; j++)
 531                                         key->u.gen.rx_pn[i][j] =
 532                                                         seq[seq_len - j - 1];
 533                         key->flags |= KEY_FLAG_CIPHER_SCHEME;
 534                 }
 535         }
 536         memcpy(key->conf.key, key_data, key_len);
 537         INIT_LIST_HEAD(&key->list);
 538
 539         return key;
 540 }
 541
 542 static void ieee80211_key_free_common(struct ieee80211_key *key)
 543 {
 544         switch (key->conf.cipher) {
 545         case WLAN_CIPHER_SUITE_CCMP:
 546         case WLAN_CIPHER_SUITE_CCMP_256:
 547                 ieee80211_aes_key_free(key->u.ccmp.tfm);
 548                 break;
 549         case WLAN_CIPHER_SUITE_AES_CMAC:
 550         case WLAN_CIPHER_SUITE_BIP_CMAC_256:
 551                 ieee80211_aes_cmac_key_free(key->u.aes_cmac.tfm);
 552                 break;
 553         case WLAN_CIPHER_SUITE_BIP_GMAC_128:
 554         case WLAN_CIPHER_SUITE_BIP_GMAC_256:
 555                 ieee80211_aes_gmac_key_free(key->u.aes_gmac.tfm);
 556                 break;
 557         case WLAN_CIPHER_SUITE_GCMP:
 558         case WLAN_CIPHER_SUITE_GCMP_256:
 559                 ieee80211_aes_gcm_key_free(key->u.gcmp.tfm);
 560                 break;
 561         }
 562         kzfree(key);
 563 }
 564
 565 static void __ieee80211_key_destroy(struct ieee80211_key *key,
 566                                     bool delay_tailroom)
 567 {
 568         if (key->local)
 569                 ieee80211_key_disable_hw_accel(key);
 570
 571         if (key->local) {
 572                 struct ieee80211_sub_if_data *sdata = key->sdata;
 573
 574                 ieee80211_debugfs_key_remove(key);
 575
 576                 if (delay_tailroom) {
 577                         /* see ieee80211_delayed_tailroom_dec */
 578                         sdata->crypto_tx_tailroom_pending_dec++;
 579                         schedule_delayed_work(&sdata->dec_tailroom_needed_wk,
 580                                               HZ/2);
 581                 } else {
 582                         decrease_tailroom_need_count(sdata, 1);
 583                 }
 584         }
 585
 586         ieee80211_key_free_common(key);
 587 }
 588
 589 static void ieee80211_key_destroy(struct ieee80211_key *key,
 590                                   bool delay_tailroom)
 591 {
 592         if (!key)
 593                 return;
 594
 595         /*
 596          * Synchronize so the TX path can no longer be using
 597          * this key before we free/remove it.
 598          */
 599         synchronize_net();
 600
 601         __ieee80211_key_destroy(key, delay_tailroom);
 602 }
 603
 604 void ieee80211_key_free_unused(struct ieee80211_key *key)
 605 {
 606         WARN_ON(key->sdata || key->local);
 607         ieee80211_key_free_common(key);
 608 }
 609
 610 int ieee80211_key_link(struct ieee80211_key *key,
 611                        struct ieee80211_sub_if_data *sdata,
 612                        struct sta_info *sta)
 613 {
 614         struct ieee80211_local *local = sdata->local;
 615         struct ieee80211_key *old_key;
 616         int idx, ret;
 617         bool pairwise;
 618
 619         pairwise = key->conf.flags & IEEE80211_KEY_FLAG_PAIRWISE;
 620         idx = key->conf.keyidx;
 621         key->local = sdata->local;
 622         key->sdata = sdata;
 623         key->sta = sta;
 624
 625         mutex_lock(&sdata->local->key_mtx);
 626
 627         if (sta && pairwise)
 628                 old_key = key_mtx_dereference(sdata->local, sta->ptk[idx]);
 629         else if (sta)
 630                 old_key = key_mtx_dereference(sdata->local, sta->gtk[idx]);
 631         else
 632                 old_key = key_mtx_dereference(sdata->local, sdata->keys[idx]);
 633
 634         increment_tailroom_need_count(sdata);
 635
 636         ieee80211_key_replace(sdata, sta, pairwise, old_key, key);
 637         ieee80211_key_destroy(old_key, true);
 638
 639         ieee80211_debugfs_key_add(key);
 640
 641         if (!local->wowlan) {
 642                 ret = ieee80211_key_enable_hw_accel(key);
 643                 if (ret)
 644                         ieee80211_key_free(key, true);
 645         } else {
 646                 ret = 0;
 647         }
 648
 649         mutex_unlock(&sdata->local->key_mtx);
 650
 651         return ret;
 652 }
 653
 654 void ieee80211_key_free(struct ieee80211_key *key, bool delay_tailroom)
 655 {
 656         if (!key)
 657                 return;
 658
 659         /*
 660          * Replace key with nothingness if it was ever used.
 661          */
 662         if (key->sdata)
 663                 ieee80211_key_replace(key->sdata, key->sta,
 664                                 key->conf.flags & IEEE80211_KEY_FLAG_PAIRWISE,
 665                                 key, NULL);
 666         ieee80211_key_destroy(key, delay_tailroom);
 667 }
 668
 669 void ieee80211_enable_keys(struct ieee80211_sub_if_data *sdata)
 670 {
 671         struct ieee80211_key *key;
 672         struct ieee80211_sub_if_data *vlan;
 673
 674         ASSERT_RTNL();
 675
 676         if (WARN_ON(!ieee80211_sdata_running(sdata)))
 677                 return;
 678
 679         mutex_lock(&sdata->local->key_mtx);
 680
 681         WARN_ON_ONCE(sdata->crypto_tx_tailroom_needed_cnt ||
 682                      sdata->crypto_tx_tailroom_pending_dec);
 683
 684         if (sdata->vif.type == NL80211_IFTYPE_AP) {
 685                 list_for_each_entry(vlan, &sdata->u.ap.vlans, u.vlan.list)
 686                         WARN_ON_ONCE(vlan->crypto_tx_tailroom_needed_cnt ||
 687                                      vlan->crypto_tx_tailroom_pending_dec);
 688         }
 689
 690         list_for_each_entry(key, &sdata->key_list, list) {
 691                 increment_tailroom_need_count(sdata);
 692                 ieee80211_key_enable_hw_accel(key);
 693         }
 694
 695         mutex_unlock(&sdata->local->key_mtx);
 696 }
 697
 698 void ieee80211_reset_crypto_tx_tailroom(struct ieee80211_sub_if_data *sdata)
 699 {
 700         struct ieee80211_sub_if_data *vlan;
 701
 702         mutex_lock(&sdata->local->key_mtx);
 703
 704         sdata->crypto_tx_tailroom_needed_cnt = 0;
 705
 706         if (sdata->vif.type == NL80211_IFTYPE_AP) {
 707                 list_for_each_entry(vlan, &sdata->u.ap.vlans, u.vlan.list)
 708                         vlan->crypto_tx_tailroom_needed_cnt = 0;
 709         }
 710
 711         mutex_unlock(&sdata->local->key_mtx);
 712 }
 713
 714 void ieee80211_iter_keys(struct ieee80211_hw *hw,
 715                          struct ieee80211_vif *vif,
 716                          void (*iter)(struct ieee80211_hw *hw,
 717                                       struct ieee80211_vif *vif,
 718                                       struct ieee80211_sta *sta,
 719                                       struct ieee80211_key_conf *key,
 720                                       void *data),
 721                          void *iter_data)
 722 {
 723         struct ieee80211_local *local = hw_to_local(hw);
 724         struct ieee80211_key *key, *tmp;
 725         struct ieee80211_sub_if_data *sdata;
 726
 727         ASSERT_RTNL();
 728
 729         mutex_lock(&local->key_mtx);
 730         if (vif) {
 731                 sdata = vif_to_sdata(vif);
 732                 list_for_each_entry_safe(key, tmp, &sdata->key_list, list)
 733                         iter(hw, &sdata->vif,
 734                              key->sta ? &key->sta->sta : NULL,
 735                              &key->conf, iter_data);
 736         } else {
 737                 list_for_each_entry(sdata, &local->interfaces, list)
 738                         list_for_each_entry_safe(key, tmp,
 739                                                  &sdata->key_list, list)
 740                                 iter(hw, &sdata->vif,
 741                                      key->sta ? &key->sta->sta : NULL,
 742                                      &key->conf, iter_data);
 743         }
 744         mutex_unlock(&local->key_mtx);
 745 }
 746 EXPORT_SYMBOL(ieee80211_iter_keys);
 747
 748 static void ieee80211_free_keys_iface(struct ieee80211_sub_if_data *sdata,
 749                                       struct list_head *keys)
 750 {
 751         struct ieee80211_key *key, *tmp;
 752
 753         decrease_tailroom_need_count(sdata,
 754                                      sdata->crypto_tx_tailroom_pending_dec);
 755         sdata->crypto_tx_tailroom_pending_dec = 0;
 756
 757         ieee80211_debugfs_key_remove_mgmt_default(sdata);
 758
 759         list_for_each_entry_safe(key, tmp, &sdata->key_list, list) {
 760                 ieee80211_key_replace(key->sdata, key->sta,
 761                                 key->conf.flags & IEEE80211_KEY_FLAG_PAIRWISE,
 762                                 key, NULL);
 763                 list_add_tail(&key->list, keys);
 764         }
 765
 766         ieee80211_debugfs_key_update_default(sdata);
 767 }
 768
 769 void ieee80211_free_keys(struct ieee80211_sub_if_data *sdata,
 770                          bool force_synchronize)
 771 {
 772         struct ieee80211_local *local = sdata->local;
 773         struct ieee80211_sub_if_data *vlan;
 774         struct ieee80211_sub_if_data *master;
 775         struct ieee80211_key *key, *tmp;
 776         LIST_HEAD(keys);
 777
 778         cancel_delayed_work_sync(&sdata->dec_tailroom_needed_wk);
 779
 780         mutex_lock(&local->key_mtx);
 781
 782         ieee80211_free_keys_iface(sdata, &keys);
 783
 784         if (sdata->vif.type == NL80211_IFTYPE_AP) {
 785                 list_for_each_entry(vlan, &sdata->u.ap.vlans, u.vlan.list)
 786                         ieee80211_free_keys_iface(vlan, &keys);
 787         }
 788
 789         if (!list_empty(&keys) || force_synchronize)
 790                 synchronize_net();
 791         list_for_each_entry_safe(key, tmp, &keys, list)
 792                 __ieee80211_key_destroy(key, false);
 793
 794         if (sdata->vif.type == NL80211_IFTYPE_AP_VLAN) {
 795                 if (sdata->bss) {
 796                         master = container_of(sdata->bss,
 797                                               struct ieee80211_sub_if_data,
 798                                               u.ap);
 799
 800                         WARN_ON_ONCE(sdata->crypto_tx_tailroom_needed_cnt !=
 801                                      master->crypto_tx_tailroom_needed_cnt);
 802                 }
 803         } else {
 804                 WARN_ON_ONCE(sdata->crypto_tx_tailroom_needed_cnt ||
 805                              sdata->crypto_tx_tailroom_pending_dec);
 806         }
 807
 808         if (sdata->vif.type == NL80211_IFTYPE_AP) {
 809                 list_for_each_entry(vlan, &sdata->u.ap.vlans, u.vlan.list)
 810                         WARN_ON_ONCE(vlan->crypto_tx_tailroom_needed_cnt ||
 811                                      vlan->crypto_tx_tailroom_pending_dec);
 812         }
 813
 814         mutex_unlock(&local->key_mtx);
 815 }
 816
 817 void ieee80211_free_sta_keys(struct ieee80211_local *local,
 818                              struct sta_info *sta)
 819 {
 820         struct ieee80211_key *key;
 821         int i;
 822
 823         mutex_lock(&local->key_mtx);
 824         for (i = 0; i < ARRAY_SIZE(sta->gtk); i++) {
 825                 key = key_mtx_dereference(local, sta->gtk[i]);
 826                 if (!key)
 827                         continue;
 828                 ieee80211_key_replace(key->sdata, key->sta,
 829                                 key->conf.flags & IEEE80211_KEY_FLAG_PAIRWISE,
 830                                 key, NULL);
 831                 __ieee80211_key_destroy(key, true);
 832         }
 833
 834         for (i = 0; i < NUM_DEFAULT_KEYS; i++) {
 835                 key = key_mtx_dereference(local, sta->ptk[i]);
 836                 if (!key)
 837                         continue;
 838                 ieee80211_key_replace(key->sdata, key->sta,
 839                                 key->conf.flags & IEEE80211_KEY_FLAG_PAIRWISE,
 840                                 key, NULL);
 841                 __ieee80211_key_destroy(key, true);
 842         }
 843
 844         mutex_unlock(&local->key_mtx);
 845 }
 846
 847 void ieee80211_delayed_tailroom_dec(struct work_struct *wk)
 848 {
 849         struct ieee80211_sub_if_data *sdata;
 850
 851         sdata = container_of(wk, struct ieee80211_sub_if_data,
 852                              dec_tailroom_needed_wk.work);
 853
 854         /*
 855          * The reason for the delayed tailroom needed decrementing is to
 856          * make roaming faster: during roaming, all keys are first deleted
 857          * and then new keys are installed. The first new key causes the
 858          * crypto_tx_tailroom_needed_cnt to go from 0 to 1, which invokes
 859          * the cost of synchronize_net() (which can be slow). Avoid this
 860          * by deferring the crypto_tx_tailroom_needed_cnt decrementing on
 861          * key removal for a while, so if we roam the value is larger than
 862          * zero and no 0->1 transition happens.
 863          *
 864          * The cost is that if the AP switching was from an AP with keys
 865          * to one without, we still allocate tailroom while it would no
 866          * longer be needed. However, in the typical (fast) roaming case
 867          * within an ESS this usually won't happen.
 868          */
 869
 870         mutex_lock(&sdata->local->key_mtx);
 871         decrease_tailroom_need_count(sdata,
 872                                      sdata->crypto_tx_tailroom_pending_dec);
 873         sdata->crypto_tx_tailroom_pending_dec = 0;
 874         mutex_unlock(&sdata->local->key_mtx);
 875 }
 876
 877 void ieee80211_gtk_rekey_notify(struct ieee80211_vif *vif, const u8 *bssid,
 878                                 const u8 *replay_ctr, gfp_t gfp)
 879 {
 880         struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
 881
 882         trace_api_gtk_rekey_notify(sdata, bssid, replay_ctr);
 883
 884         cfg80211_gtk_rekey_notify(sdata->dev, bssid, replay_ctr, gfp);
 885 }
 886 EXPORT_SYMBOL_GPL(ieee80211_gtk_rekey_notify);
 887
 888 void ieee80211_get_key_tx_seq(struct ieee80211_key_conf *keyconf,
 889                               struct ieee80211_key_seq *seq)
 890 {
 891         struct ieee80211_key *key;
 892         u64 pn64;
 893
 894         if (WARN_ON(!(keyconf->flags & IEEE80211_KEY_FLAG_GENERATE_IV)))
 895                 return;
 896
 897         key = container_of(keyconf, struct ieee80211_key, conf);
 898
 899         switch (key->conf.cipher) {
 900         case WLAN_CIPHER_SUITE_TKIP:
 901                 seq->tkip.iv32 = key->u.tkip.tx.iv32;
 902                 seq->tkip.iv16 = key->u.tkip.tx.iv16;
 903                 break;
 904         case WLAN_CIPHER_SUITE_CCMP:
 905         case WLAN_CIPHER_SUITE_CCMP_256:
 906         case WLAN_CIPHER_SUITE_AES_CMAC:
 907         case WLAN_CIPHER_SUITE_BIP_CMAC_256:
 908                 BUILD_BUG_ON(offsetof(typeof(*seq), ccmp) !=
 909                              offsetof(typeof(*seq), aes_cmac));
 910         case WLAN_CIPHER_SUITE_BIP_GMAC_128:
 911         case WLAN_CIPHER_SUITE_BIP_GMAC_256:
 912                 BUILD_BUG_ON(offsetof(typeof(*seq), ccmp) !=
 913                              offsetof(typeof(*seq), aes_gmac));
 914         case WLAN_CIPHER_SUITE_GCMP:
 915         case WLAN_CIPHER_SUITE_GCMP_256:
 916                 BUILD_BUG_ON(offsetof(typeof(*seq), ccmp) !=
 917                              offsetof(typeof(*seq), gcmp));
 918                 pn64 = atomic64_read(&key->conf.tx_pn);
 919                 seq->ccmp.pn[5] = pn64;
 920                 seq->ccmp.pn[4] = pn64 >> 8;
 921                 seq->ccmp.pn[3] = pn64 >> 16;
 922                 seq->ccmp.pn[2] = pn64 >> 24;
 923                 seq->ccmp.pn[1] = pn64 >> 32;
 924                 seq->ccmp.pn[0] = pn64 >> 40;
 925                 break;
 926         default:
 927                 WARN_ON(1);
 928         }
 929 }
 930 EXPORT_SYMBOL(ieee80211_get_key_tx_seq);
 931
 932 void ieee80211_get_key_rx_seq(struct ieee80211_key_conf *keyconf,
 933                               int tid, struct ieee80211_key_seq *seq)
 934 {
 935         struct ieee80211_key *key;
 936         const u8 *pn;
 937
 938         key = container_of(keyconf, struct ieee80211_key, conf);
 939
 940         switch (key->conf.cipher) {
 941         case WLAN_CIPHER_SUITE_TKIP:
 942                 if (WARN_ON(tid < 0 || tid >= IEEE80211_NUM_TIDS))
 943                         return;
 944                 seq->tkip.iv32 = key->u.tkip.rx[tid].iv32;
 945                 seq->tkip.iv16 = key->u.tkip.rx[tid].iv16;
 946                 break;
 947         case WLAN_CIPHER_SUITE_CCMP:
 948         case WLAN_CIPHER_SUITE_CCMP_256:
 949                 if (WARN_ON(tid < -1 || tid >= IEEE80211_NUM_TIDS))
 950                         return;
 951                 if (tid < 0)
 952                         pn = key->u.ccmp.rx_pn[IEEE80211_NUM_TIDS];
 953                 else
 954                         pn = key->u.ccmp.rx_pn[tid];
 955                 memcpy(seq->ccmp.pn, pn, IEEE80211_CCMP_PN_LEN);
 956                 break;
 957         case WLAN_CIPHER_SUITE_AES_CMAC:
 958         case WLAN_CIPHER_SUITE_BIP_CMAC_256:
 959                 if (WARN_ON(tid != 0))
 960                         return;
 961                 pn = key->u.aes_cmac.rx_pn;
 962                 memcpy(seq->aes_cmac.pn, pn, IEEE80211_CMAC_PN_LEN);
 963                 break;
 964         case WLAN_CIPHER_SUITE_BIP_GMAC_128:
 965         case WLAN_CIPHER_SUITE_BIP_GMAC_256:
 966                 if (WARN_ON(tid != 0))
 967                         return;
 968                 pn = key->u.aes_gmac.rx_pn;
 969                 memcpy(seq->aes_gmac.pn, pn, IEEE80211_GMAC_PN_LEN);
 970                 break;
 971         case WLAN_CIPHER_SUITE_GCMP:
 972         case WLAN_CIPHER_SUITE_GCMP_256:
 973                 if (WARN_ON(tid < -1 || tid >= IEEE80211_NUM_TIDS))
 974                         return;
 975                 if (tid < 0)
 976                         pn = key->u.gcmp.rx_pn[IEEE80211_NUM_TIDS];
 977                 else
 978                         pn = key->u.gcmp.rx_pn[tid];
 979                 memcpy(seq->gcmp.pn, pn, IEEE80211_GCMP_PN_LEN);
 980                 break;
 981         }
 982 }
 983 EXPORT_SYMBOL(ieee80211_get_key_rx_seq);
 984
 985 void ieee80211_set_key_tx_seq(struct ieee80211_key_conf *keyconf,
 986                               struct ieee80211_key_seq *seq)
 987 {
 988         struct ieee80211_key *key;
 989         u64 pn64;
 990
 991         key = container_of(keyconf, struct ieee80211_key, conf);
 992
 993         switch (key->conf.cipher) {
 994         case WLAN_CIPHER_SUITE_TKIP:
 995                 key->u.tkip.tx.iv32 = seq->tkip.iv32;
 996                 key->u.tkip.tx.iv16 = seq->tkip.iv16;
 997                 break;
 998         case WLAN_CIPHER_SUITE_CCMP:
 999         case WLAN_CIPHER_SUITE_CCMP_256:
1000         case WLAN_CIPHER_SUITE_AES_CMAC:
1001         case WLAN_CIPHER_SUITE_BIP_CMAC_256:
1002                 BUILD_BUG_ON(offsetof(typeof(*seq), ccmp) !=
1003                              offsetof(typeof(*seq), aes_cmac));
1004         case WLAN_CIPHER_SUITE_BIP_GMAC_128:
1005         case WLAN_CIPHER_SUITE_BIP_GMAC_256:
1006                 BUILD_BUG_ON(offsetof(typeof(*seq), ccmp) !=
1007                              offsetof(typeof(*seq), aes_gmac));
1008         case WLAN_CIPHER_SUITE_GCMP:
1009         case WLAN_CIPHER_SUITE_GCMP_256:
1010                 BUILD_BUG_ON(offsetof(typeof(*seq), ccmp) !=
1011                              offsetof(typeof(*seq), gcmp));
1012                 pn64 = (u64)seq->ccmp.pn[5] |
1013                        ((u64)seq->ccmp.pn[4] << 8) |
1014                        ((u64)seq->ccmp.pn[3] << 16) |
1015                        ((u64)seq->ccmp.pn[2] << 24) |
1016                        ((u64)seq->ccmp.pn[1] << 32) |
1017                        ((u64)seq->ccmp.pn[0] << 40);
1018                 atomic64_set(&key->conf.tx_pn, pn64);
1019                 break;
1020         default:
1021                 WARN_ON(1);
1022                 break;
1023         }
1024 }
1025 EXPORT_SYMBOL_GPL(ieee80211_set_key_tx_seq);
1026
1027 void ieee80211_set_key_rx_seq(struct ieee80211_key_conf *keyconf,
1028                               int tid, struct ieee80211_key_seq *seq)
1029 {
1030         struct ieee80211_key *key;
1031         u8 *pn;
1032
1033         key = container_of(keyconf, struct ieee80211_key, conf);
1034
1035         switch (key->conf.cipher) {
1036         case WLAN_CIPHER_SUITE_TKIP:
1037                 if (WARN_ON(tid < 0 || tid >= IEEE80211_NUM_TIDS))
1038                         return;
1039                 key->u.tkip.rx[tid].iv32 = seq->tkip.iv32;
1040                 key->u.tkip.rx[tid].iv16 = seq->tkip.iv16;
1041                 break;
1042         case WLAN_CIPHER_SUITE_CCMP:
1043         case WLAN_CIPHER_SUITE_CCMP_256:
1044                 if (WARN_ON(tid < -1 || tid >= IEEE80211_NUM_TIDS))
1045                         return;
1046                 if (tid < 0)
1047                         pn = key->u.ccmp.rx_pn[IEEE80211_NUM_TIDS];
1048                 else
1049                         pn = key->u.ccmp.rx_pn[tid];
1050                 memcpy(pn, seq->ccmp.pn, IEEE80211_CCMP_PN_LEN);
1051                 break;
1052         case WLAN_CIPHER_SUITE_AES_CMAC:
1053         case WLAN_CIPHER_SUITE_BIP_CMAC_256:
1054                 if (WARN_ON(tid != 0))
1055                         return;
1056                 pn = key->u.aes_cmac.rx_pn;
1057                 memcpy(pn, seq->aes_cmac.pn, IEEE80211_CMAC_PN_LEN);
1058                 break;
1059         case WLAN_CIPHER_SUITE_BIP_GMAC_128:
1060         case WLAN_CIPHER_SUITE_BIP_GMAC_256:
1061                 if (WARN_ON(tid != 0))
1062                         return;
1063                 pn = key->u.aes_gmac.rx_pn;
1064                 memcpy(pn, seq->aes_gmac.pn, IEEE80211_GMAC_PN_LEN);
1065                 break;
1066         case WLAN_CIPHER_SUITE_GCMP:
1067         case WLAN_CIPHER_SUITE_GCMP_256:
1068                 if (WARN_ON(tid < -1 || tid >= IEEE80211_NUM_TIDS))
1069                         return;
1070                 if (tid < 0)
1071                         pn = key->u.gcmp.rx_pn[IEEE80211_NUM_TIDS];
1072                 else
1073                         pn = key->u.gcmp.rx_pn[tid];
1074                 memcpy(pn, seq->gcmp.pn, IEEE80211_GCMP_PN_LEN);
1075                 break;
1076         default:
1077                 WARN_ON(1);
1078                 break;
1079         }
1080 }
1081 EXPORT_SYMBOL_GPL(ieee80211_set_key_rx_seq);
1082
1083 void ieee80211_remove_key(struct ieee80211_key_conf *keyconf)
1084 {
1085         struct ieee80211_key *key;
1086
1087         key = container_of(keyconf, struct ieee80211_key, conf);
1088
1089         assert_key_lock(key->local);
1090
1091         /*
1092          * if key was uploaded, we assume the driver will/has remove(d)
1093          * it, so adjust bookkeeping accordingly
1094          */
1095         if (key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE) {
1096                 key->flags &= ~KEY_FLAG_UPLOADED_TO_HARDWARE;
1097
1098                 if (!((key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_MMIC) ||
1099                       (key->conf.flags & IEEE80211_KEY_FLAG_RESERVE_TAILROOM)))
1100                         increment_tailroom_need_count(key->sdata);
1101         }
1102
1103         ieee80211_key_free(key, false);
1104 }
1105 EXPORT_SYMBOL_GPL(ieee80211_remove_key);
1106
1107 struct ieee80211_key_conf *
1108 ieee80211_gtk_rekey_add(struct ieee80211_vif *vif,
1109                         struct ieee80211_key_conf *keyconf)
1110 {
1111         struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
1112         struct ieee80211_local *local = sdata->local;
1113         struct ieee80211_key *key;
1114         int err;
1115
1116         if (WARN_ON(!local->wowlan))
1117                 return ERR_PTR(-EINVAL);
1118
1119         if (WARN_ON(vif->type != NL80211_IFTYPE_STATION))
1120                 return ERR_PTR(-EINVAL);
1121
1122         key = ieee80211_key_alloc(keyconf->cipher, keyconf->keyidx,
1123                                   keyconf->keylen, keyconf->key,
1124                                   0, NULL, NULL);
1125         if (IS_ERR(key))
1126                 return ERR_CAST(key);
1127
1128         if (sdata->u.mgd.mfp != IEEE80211_MFP_DISABLED)
1129                 key->conf.flags |= IEEE80211_KEY_FLAG_RX_MGMT;
1130
1131         err = ieee80211_key_link(key, sdata, NULL);
1132         if (err)
1133                 return ERR_PTR(err);
1134
1135         return &key->conf;
1136 }
1137 EXPORT_SYMBOL_GPL(ieee80211_gtk_rekey_add);