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  * Copyright 2015-2017  Intel Deutschland GmbH
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License version 2 as
  11  * published by the Free Software Foundation.
  12  */
  13
  14 #include <linux/if_ether.h>
  15 #include <linux/etherdevice.h>
  16 #include <linux/list.h>
  17 #include <linux/rcupdate.h>
  18 #include <linux/rtnetlink.h>
  19 #include <linux/slab.h>
  20 #include <linux/export.h>
  21 #include <net/mac80211.h>
  22 #include <crypto/algapi.h>
  23 #include <asm/unaligned.h>
  24 #include "ieee80211_i.h"
  25 #include "driver-ops.h"
  26 #include "debugfs_key.h"
  27 #include "aes_ccm.h"
  28 #include "aes_cmac.h"
  29 #include "aes_gmac.h"
  30 #include "aes_gcm.h"
  31
  32
  33 /**
  34  * DOC: Key handling basics
  35  *
  36  * Key handling in mac80211 is done based on per-interface (sub_if_data)
  37  * keys and per-station keys. Since each station belongs to an interface,
  38  * each station key also belongs to that interface.
  39  *
  40  * Hardware acceleration is done on a best-effort basis for algorithms
  41  * that are implemented in software,  for each key the hardware is asked
  42  * to enable that key for offloading but if it cannot do that the key is
  43  * simply kept for software encryption (unless it is for an algorithm
  44  * that isn't implemented in software).
  45  * There is currently no way of knowing whether a key is handled in SW
  46  * or HW except by looking into debugfs.
  47  *
  48  * All key management is internally protected by a mutex. Within all
  49  * other parts of mac80211, key references are, just as STA structure
  50  * references, protected by RCU. Note, however, that some things are
  51  * unprotected, namely the key->sta dereferences within the hardware
  52  * acceleration functions. This means that sta_info_destroy() must
  53  * remove the key which waits for an RCU grace period.
  54  */
  55
  56 static const u8 bcast_addr[ETH_ALEN] = { 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF };
  57
  58 static void assert_key_lock(struct ieee80211_local *local)
  59 {
  60         lockdep_assert_held(&local->key_mtx);
  61 }
  62
  63 static void
  64 update_vlan_tailroom_need_count(struct ieee80211_sub_if_data *sdata, int delta)
  65 {
  66         struct ieee80211_sub_if_data *vlan;
  67
  68         if (sdata->vif.type != NL80211_IFTYPE_AP)
  69                 return;
  70
  71         /* crypto_tx_tailroom_needed_cnt is protected by this */
  72         assert_key_lock(sdata->local);
  73
  74         rcu_read_lock();
  75
  76         list_for_each_entry_rcu(vlan, &sdata->u.ap.vlans, u.vlan.list)
  77                 vlan->crypto_tx_tailroom_needed_cnt += delta;
  78
  79         rcu_read_unlock();
  80 }
  81
  82 static void increment_tailroom_need_count(struct ieee80211_sub_if_data *sdata)
  83 {
  84         /*
  85          * When this count is zero, SKB resizing for allocating tailroom
  86          * for IV or MMIC is skipped. But, this check has created two race
  87          * cases in xmit path while transiting from zero count to one:
  88          *
  89          * 1. SKB resize was skipped because no key was added but just before
  90          * the xmit key is added and SW encryption kicks off.
  91          *
  92          * 2. SKB resize was skipped because all the keys were hw planted but
  93          * just before xmit one of the key is deleted and SW encryption kicks
  94          * off.
  95          *
  96          * In both the above case SW encryption will find not enough space for
  97          * tailroom and exits with WARN_ON. (See WARN_ONs at wpa.c)
  98          *
  99          * Solution has been explained at
 100          * http://mid.gmane.org/1308590980.4322.19.camel@jlt3.sipsolutions.net
 101          */
 102
 103         assert_key_lock(sdata->local);
 104
 105         update_vlan_tailroom_need_count(sdata, 1);
 106
 107         if (!sdata->crypto_tx_tailroom_needed_cnt++) {
 108                 /*
 109                  * Flush all XMIT packets currently using HW encryption or no
 110                  * encryption at all if the count transition is from 0 -> 1.
 111                  */
 112                 synchronize_net();
 113         }
 114 }
 115
 116 static void decrease_tailroom_need_count(struct ieee80211_sub_if_data *sdata,
 117                                          int delta)
 118 {
 119         assert_key_lock(sdata->local);
 120
 121         WARN_ON_ONCE(sdata->crypto_tx_tailroom_needed_cnt < delta);
 122
 123         update_vlan_tailroom_need_count(sdata, -delta);
 124         sdata->crypto_tx_tailroom_needed_cnt -= delta;
 125 }
 126
 127 static int ieee80211_key_enable_hw_accel(struct ieee80211_key *key)
 128 {
 129         struct ieee80211_sub_if_data *sdata;
 130         struct sta_info *sta;
 131         int ret = -EOPNOTSUPP;
 132
 133         might_sleep();
 134
 135         if (key->flags & KEY_FLAG_TAINTED) {
 136                 /* If we get here, it's during resume and the key is
 137                  * tainted so shouldn't be used/programmed any more.
 138                  * However, its flags may still indicate that it was
 139                  * programmed into the device (since we're in resume)
 140                  * so clear that flag now to avoid trying to remove
 141                  * it again later.
 142                  */
 143                 key->flags &= ~KEY_FLAG_UPLOADED_TO_HARDWARE;
 144                 return -EINVAL;
 145         }
 146
 147         if (!key->local->ops->set_key)
 148                 goto out_unsupported;
 149
 150         assert_key_lock(key->local);
 151
 152         sta = key->sta;
 153
 154         /*
 155          * If this is a per-STA GTK, check if it
 156          * is supported; if not, return.
 157          */
 158         if (sta && !(key->conf.flags & IEEE80211_KEY_FLAG_PAIRWISE) &&
 159             !ieee80211_hw_check(&key->local->hw, SUPPORTS_PER_STA_GTK))
 160                 goto out_unsupported;
 161
 162         if (sta && !sta->uploaded)
 163                 goto out_unsupported;
 164
 165         sdata = key->sdata;
 166         if (sdata->vif.type == NL80211_IFTYPE_AP_VLAN) {
 167                 /*
 168                  * The driver doesn't know anything about VLAN interfaces.
 169                  * Hence, don't send GTKs for VLAN interfaces to the driver.
 170                  */
 171                 if (!(key->conf.flags & IEEE80211_KEY_FLAG_PAIRWISE))
 172                         goto out_unsupported;
 173         }
 174
 175         ret = drv_set_key(key->local, SET_KEY, sdata,
 176                           sta ? &sta->sta : NULL, &key->conf);
 177
 178         if (!ret) {
 179                 key->flags |= KEY_FLAG_UPLOADED_TO_HARDWARE;
 180
 181                 if (!((key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_MMIC) ||
 182                       (key->conf.flags & IEEE80211_KEY_FLAG_RESERVE_TAILROOM)))
 183                         decrease_tailroom_need_count(sdata, 1);
 184
 185                 WARN_ON((key->conf.flags & IEEE80211_KEY_FLAG_PUT_IV_SPACE) &&
 186                         (key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_IV));
 187
 188                 return 0;
 189         }
 190
 191         if (ret != -ENOSPC && ret != -EOPNOTSUPP && ret != 1)
 192                 sdata_err(sdata,
 193                           "failed to set key (%d, %pM) to hardware (%d)\n",
 194                           key->conf.keyidx,
 195                           sta ? sta->sta.addr : bcast_addr, ret);
 196
 197  out_unsupported:
 198         switch (key->conf.cipher) {
 199         case WLAN_CIPHER_SUITE_WEP40:
 200         case WLAN_CIPHER_SUITE_WEP104:
 201         case WLAN_CIPHER_SUITE_TKIP:
 202         case WLAN_CIPHER_SUITE_CCMP:
 203         case WLAN_CIPHER_SUITE_CCMP_256:
 204         case WLAN_CIPHER_SUITE_AES_CMAC:
 205         case WLAN_CIPHER_SUITE_BIP_CMAC_256:
 206         case WLAN_CIPHER_SUITE_BIP_GMAC_128:
 207         case WLAN_CIPHER_SUITE_BIP_GMAC_256:
 208         case WLAN_CIPHER_SUITE_GCMP:
 209         case WLAN_CIPHER_SUITE_GCMP_256:
 210                 /* all of these we can do in software - if driver can */
 211                 if (ret == 1)
 212                         return 0;
 213                 if (ieee80211_hw_check(&key->local->hw, SW_CRYPTO_CONTROL))
 214                         return -EINVAL;
 215                 return 0;
 216         default:
 217                 return -EINVAL;
 218         }
 219 }
 220
 221 static void ieee80211_key_disable_hw_accel(struct ieee80211_key *key)
 222 {
 223         struct ieee80211_sub_if_data *sdata;
 224         struct sta_info *sta;
 225         int ret;
 226
 227         might_sleep();
 228
 229         if (!key || !key->local->ops->set_key)
 230                 return;
 231
 232         assert_key_lock(key->local);
 233
 234         if (!(key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE))
 235                 return;
 236
 237         sta = key->sta;
 238         sdata = key->sdata;
 239
 240         if (!((key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_MMIC) ||
 241               (key->conf.flags & IEEE80211_KEY_FLAG_RESERVE_TAILROOM)))
 242                 increment_tailroom_need_count(sdata);
 243
 244         ret = drv_set_key(key->local, DISABLE_KEY, sdata,
 245                           sta ? &sta->sta : NULL, &key->conf);
 246
 247         if (ret)
 248                 sdata_err(sdata,
 249                           "failed to remove key (%d, %pM) from hardware (%d)\n",
 250                           key->conf.keyidx,
 251                           sta ? sta->sta.addr : bcast_addr, ret);
 252
 253         key->flags &= ~KEY_FLAG_UPLOADED_TO_HARDWARE;
 254 }
 255
 256 static void __ieee80211_set_default_key(struct ieee80211_sub_if_data *sdata,
 257                                         int idx, bool uni, bool multi)
 258 {
 259         struct ieee80211_key *key = NULL;
 260
 261         assert_key_lock(sdata->local);
 262
 263         if (idx >= 0 && idx < NUM_DEFAULT_KEYS)
 264                 key = key_mtx_dereference(sdata->local, sdata->keys[idx]);
 265
 266         if (uni) {
 267                 rcu_assign_pointer(sdata->default_unicast_key, key);
 268                 ieee80211_check_fast_xmit_iface(sdata);
 269                 drv_set_default_unicast_key(sdata->local, sdata, idx);
 270         }
 271
 272         if (multi)
 273                 rcu_assign_pointer(sdata->default_multicast_key, key);
 274
 275         ieee80211_debugfs_key_update_default(sdata);
 276 }
 277
 278 void ieee80211_set_default_key(struct ieee80211_sub_if_data *sdata, int idx,
 279                                bool uni, bool multi)
 280 {
 281         mutex_lock(&sdata->local->key_mtx);
 282         __ieee80211_set_default_key(sdata, idx, uni, multi);
 283         mutex_unlock(&sdata->local->key_mtx);
 284 }
 285
 286 static void
 287 __ieee80211_set_default_mgmt_key(struct ieee80211_sub_if_data *sdata, int idx)
 288 {
 289         struct ieee80211_key *key = NULL;
 290
 291         assert_key_lock(sdata->local);
 292
 293         if (idx >= NUM_DEFAULT_KEYS &&
 294             idx < NUM_DEFAULT_KEYS + NUM_DEFAULT_MGMT_KEYS)
 295                 key = key_mtx_dereference(sdata->local, sdata->keys[idx]);
 296
 297         rcu_assign_pointer(sdata->default_mgmt_key, key);
 298
 299         ieee80211_debugfs_key_update_default(sdata);
 300 }
 301
 302 void ieee80211_set_default_mgmt_key(struct ieee80211_sub_if_data *sdata,
 303                                     int idx)
 304 {
 305         mutex_lock(&sdata->local->key_mtx);
 306         __ieee80211_set_default_mgmt_key(sdata, idx);
 307         mutex_unlock(&sdata->local->key_mtx);
 308 }
 309
 310
 311 static void ieee80211_key_replace(struct ieee80211_sub_if_data *sdata,
 312                                   struct sta_info *sta,
 313                                   bool pairwise,
 314                                   struct ieee80211_key *old,
 315                                   struct ieee80211_key *new)
 316 {
 317         int idx;
 318         bool defunikey, defmultikey, defmgmtkey;
 319
 320         /* caller must provide at least one old/new */
 321         if (WARN_ON(!new && !old))
 322                 return;
 323
 324         if (new)
 325                 list_add_tail_rcu(&new->list, &sdata->key_list);
 326
 327         WARN_ON(new && old && new->conf.keyidx != old->conf.keyidx);
 328
 329         if (old)
 330                 idx = old->conf.keyidx;
 331         else
 332                 idx = new->conf.keyidx;
 333
 334         if (sta) {
 335                 if (pairwise) {
 336                         rcu_assign_pointer(sta->ptk[idx], new);
 337                         set_sta_flag(sta, WLAN_STA_USES_ENCRYPTION);
 338                         sta->ptk_idx = idx;
 339                         ieee80211_check_fast_xmit(sta);
 340                 } else {
 341                         rcu_assign_pointer(sta->gtk[idx], new);
 342                 }
 343                 ieee80211_check_fast_rx(sta);
 344         } else {
 345                 defunikey = old &&
 346                         old == key_mtx_dereference(sdata->local,
 347                                                 sdata->default_unicast_key);
 348                 defmultikey = old &&
 349                         old == key_mtx_dereference(sdata->local,
 350                                                 sdata->default_multicast_key);
 351                 defmgmtkey = old &&
 352                         old == key_mtx_dereference(sdata->local,
 353                                                 sdata->default_mgmt_key);
 354
 355                 if (defunikey && !new)
 356                         __ieee80211_set_default_key(sdata, -1, true, false);
 357                 if (defmultikey && !new)
 358                         __ieee80211_set_default_key(sdata, -1, false, true);
 359                 if (defmgmtkey && !new)
 360                         __ieee80211_set_default_mgmt_key(sdata, -1);
 361
 362                 rcu_assign_pointer(sdata->keys[idx], new);
 363                 if (defunikey && new)
 364                         __ieee80211_set_default_key(sdata, new->conf.keyidx,
 365                                                     true, false);
 366                 if (defmultikey && new)
 367                         __ieee80211_set_default_key(sdata, new->conf.keyidx,
 368                                                     false, true);
 369                 if (defmgmtkey && new)
 370                         __ieee80211_set_default_mgmt_key(sdata,
 371                                                          new->conf.keyidx);
 372         }
 373
 374         if (old)
 375                 list_del_rcu(&old->list);
 376 }
 377
 378 struct ieee80211_key *
 379 ieee80211_key_alloc(u32 cipher, int idx, size_t key_len,
 380                     const u8 *key_data,
 381                     size_t seq_len, const u8 *seq,
 382                     const struct ieee80211_cipher_scheme *cs)
 383 {
 384         struct ieee80211_key *key;
 385         int i, j, err;
 386
 387         if (WARN_ON(idx < 0 || idx >= NUM_DEFAULT_KEYS + NUM_DEFAULT_MGMT_KEYS))
 388                 return ERR_PTR(-EINVAL);
 389
 390         key = kzalloc(sizeof(struct ieee80211_key) + key_len, GFP_KERNEL);
 391         if (!key)
 392                 return ERR_PTR(-ENOMEM);
 393
 394         /*
 395          * Default to software encryption; we'll later upload the
 396          * key to the hardware if possible.
 397          */
 398         key->conf.flags = 0;
 399         key->flags = 0;
 400
 401         key->conf.cipher = cipher;
 402         key->conf.keyidx = idx;
 403         key->conf.keylen = key_len;
 404         switch (cipher) {
 405         case WLAN_CIPHER_SUITE_WEP40:
 406         case WLAN_CIPHER_SUITE_WEP104:
 407                 key->conf.iv_len = IEEE80211_WEP_IV_LEN;
 408                 key->conf.icv_len = IEEE80211_WEP_ICV_LEN;
 409                 break;
 410         case WLAN_CIPHER_SUITE_TKIP:
 411                 key->conf.iv_len = IEEE80211_TKIP_IV_LEN;
 412                 key->conf.icv_len = IEEE80211_TKIP_ICV_LEN;
 413                 if (seq) {
 414                         for (i = 0; i < IEEE80211_NUM_TIDS; i++) {
 415                                 key->u.tkip.rx[i].iv32 =
 416                                         get_unaligned_le32(&seq[2]);
 417                                 key->u.tkip.rx[i].iv16 =
 418                                         get_unaligned_le16(seq);
 419                         }
 420                 }
 421                 spin_lock_init(&key->u.tkip.txlock);
 422                 break;
 423         case WLAN_CIPHER_SUITE_CCMP:
 424                 key->conf.iv_len = IEEE80211_CCMP_HDR_LEN;
 425                 key->conf.icv_len = IEEE80211_CCMP_MIC_LEN;
 426                 if (seq) {
 427                         for (i = 0; i < IEEE80211_NUM_TIDS + 1; i++)
 428                                 for (j = 0; j < IEEE80211_CCMP_PN_LEN; j++)
 429                                         key->u.ccmp.rx_pn[i][j] =
 430                                                 seq[IEEE80211_CCMP_PN_LEN - j - 1];
 431                 }
 432                 /*
 433                  * Initialize AES key state here as an optimization so that
 434                  * it does not need to be initialized for every packet.
 435                  */
 436                 key->u.ccmp.tfm = ieee80211_aes_key_setup_encrypt(
 437                         key_data, key_len, IEEE80211_CCMP_MIC_LEN);
 438                 if (IS_ERR(key->u.ccmp.tfm)) {
 439                         err = PTR_ERR(key->u.ccmp.tfm);
 440                         kfree(key);
 441                         return ERR_PTR(err);
 442                 }
 443                 break;
 444         case WLAN_CIPHER_SUITE_CCMP_256:
 445                 key->conf.iv_len = IEEE80211_CCMP_256_HDR_LEN;
 446                 key->conf.icv_len = IEEE80211_CCMP_256_MIC_LEN;
 447                 for (i = 0; seq && i < IEEE80211_NUM_TIDS + 1; i++)
 448                         for (j = 0; j < IEEE80211_CCMP_256_PN_LEN; j++)
 449                                 key->u.ccmp.rx_pn[i][j] =
 450                                         seq[IEEE80211_CCMP_256_PN_LEN - j - 1];
 451                 /* Initialize AES key state here as an optimization so that
 452                  * it does not need to be initialized for every packet.
 453                  */
 454                 key->u.ccmp.tfm = ieee80211_aes_key_setup_encrypt(
 455                         key_data, key_len, IEEE80211_CCMP_256_MIC_LEN);
 456                 if (IS_ERR(key->u.ccmp.tfm)) {
 457                         err = PTR_ERR(key->u.ccmp.tfm);
 458                         kfree(key);
 459                         return ERR_PTR(err);
 460                 }
 461                 break;
 462         case WLAN_CIPHER_SUITE_AES_CMAC:
 463         case WLAN_CIPHER_SUITE_BIP_CMAC_256:
 464                 key->conf.iv_len = 0;
 465                 if (cipher == WLAN_CIPHER_SUITE_AES_CMAC)
 466                         key->conf.icv_len = sizeof(struct ieee80211_mmie);
 467                 else
 468                         key->conf.icv_len = sizeof(struct ieee80211_mmie_16);
 469                 if (seq)
 470                         for (j = 0; j < IEEE80211_CMAC_PN_LEN; j++)
 471                                 key->u.aes_cmac.rx_pn[j] =
 472                                         seq[IEEE80211_CMAC_PN_LEN - j - 1];
 473                 /*
 474                  * Initialize AES key state here as an optimization so that
 475                  * it does not need to be initialized for every packet.
 476                  */
 477                 key->u.aes_cmac.tfm =
 478                         ieee80211_aes_cmac_key_setup(key_data, key_len);
 479                 if (IS_ERR(key->u.aes_cmac.tfm)) {
 480                         err = PTR_ERR(key->u.aes_cmac.tfm);
 481                         kfree(key);
 482                         return ERR_PTR(err);
 483                 }
 484                 break;
 485         case WLAN_CIPHER_SUITE_BIP_GMAC_128:
 486         case WLAN_CIPHER_SUITE_BIP_GMAC_256:
 487                 key->conf.iv_len = 0;
 488                 key->conf.icv_len = sizeof(struct ieee80211_mmie_16);
 489                 if (seq)
 490                         for (j = 0; j < IEEE80211_GMAC_PN_LEN; j++)
 491                                 key->u.aes_gmac.rx_pn[j] =
 492                                         seq[IEEE80211_GMAC_PN_LEN - j - 1];
 493                 /* Initialize AES key state here as an optimization so that
 494                  * it does not need to be initialized for every packet.
 495                  */
 496                 key->u.aes_gmac.tfm =
 497                         ieee80211_aes_gmac_key_setup(key_data, key_len);
 498                 if (IS_ERR(key->u.aes_gmac.tfm)) {
 499                         err = PTR_ERR(key->u.aes_gmac.tfm);
 500                         kfree(key);
 501                         return ERR_PTR(err);
 502                 }
 503                 break;
 504         case WLAN_CIPHER_SUITE_GCMP:
 505         case WLAN_CIPHER_SUITE_GCMP_256:
 506                 key->conf.iv_len = IEEE80211_GCMP_HDR_LEN;
 507                 key->conf.icv_len = IEEE80211_GCMP_MIC_LEN;
 508                 for (i = 0; seq && i < IEEE80211_NUM_TIDS + 1; i++)
 509                         for (j = 0; j < IEEE80211_GCMP_PN_LEN; j++)
 510                                 key->u.gcmp.rx_pn[i][j] =
 511                                         seq[IEEE80211_GCMP_PN_LEN - j - 1];
 512                 /* Initialize AES key state here as an optimization so that
 513                  * it does not need to be initialized for every packet.
 514                  */
 515                 key->u.gcmp.tfm = ieee80211_aes_gcm_key_setup_encrypt(key_data,
 516                                                                       key_len);
 517                 if (IS_ERR(key->u.gcmp.tfm)) {
 518                         err = PTR_ERR(key->u.gcmp.tfm);
 519                         kfree(key);
 520                         return ERR_PTR(err);
 521                 }
 522                 break;
 523         default:
 524                 if (cs) {
 525                         if (seq_len && seq_len != cs->pn_len) {
 526                                 kfree(key);
 527                                 return ERR_PTR(-EINVAL);
 528                         }
 529
 530                         key->conf.iv_len = cs->hdr_len;
 531                         key->conf.icv_len = cs->mic_len;
 532                         for (i = 0; i < IEEE80211_NUM_TIDS + 1; i++)
 533                                 for (j = 0; j < seq_len; j++)
 534                                         key->u.gen.rx_pn[i][j] =
 535                                                         seq[seq_len - j - 1];
 536                         key->flags |= KEY_FLAG_CIPHER_SCHEME;
 537                 }
 538         }
 539         memcpy(key->conf.key, key_data, key_len);
 540         INIT_LIST_HEAD(&key->list);
 541
 542         return key;
 543 }
 544
 545 static void ieee80211_key_free_common(struct ieee80211_key *key)
 546 {
 547         switch (key->conf.cipher) {
 548         case WLAN_CIPHER_SUITE_CCMP:
 549         case WLAN_CIPHER_SUITE_CCMP_256:
 550                 ieee80211_aes_key_free(key->u.ccmp.tfm);
 551                 break;
 552         case WLAN_CIPHER_SUITE_AES_CMAC:
 553         case WLAN_CIPHER_SUITE_BIP_CMAC_256:
 554                 ieee80211_aes_cmac_key_free(key->u.aes_cmac.tfm);
 555                 break;
 556         case WLAN_CIPHER_SUITE_BIP_GMAC_128:
 557         case WLAN_CIPHER_SUITE_BIP_GMAC_256:
 558                 ieee80211_aes_gmac_key_free(key->u.aes_gmac.tfm);
 559                 break;
 560         case WLAN_CIPHER_SUITE_GCMP:
 561         case WLAN_CIPHER_SUITE_GCMP_256:
 562                 ieee80211_aes_gcm_key_free(key->u.gcmp.tfm);
 563                 break;
 564         }
 565         kzfree(key);
 566 }
 567
 568 static void __ieee80211_key_destroy(struct ieee80211_key *key,
 569                                     bool delay_tailroom)
 570 {
 571         if (key->local)
 572                 ieee80211_key_disable_hw_accel(key);
 573
 574         if (key->local) {
 575                 struct ieee80211_sub_if_data *sdata = key->sdata;
 576
 577                 ieee80211_debugfs_key_remove(key);
 578
 579                 if (delay_tailroom) {
 580                         /* see ieee80211_delayed_tailroom_dec */
 581                         sdata->crypto_tx_tailroom_pending_dec++;
 582                         schedule_delayed_work(&sdata->dec_tailroom_needed_wk,
 583                                               HZ/2);
 584                 } else {
 585                         decrease_tailroom_need_count(sdata, 1);
 586                 }
 587         }
 588
 589         ieee80211_key_free_common(key);
 590 }
 591
 592 static void ieee80211_key_destroy(struct ieee80211_key *key,
 593                                   bool delay_tailroom)
 594 {
 595         if (!key)
 596                 return;
 597
 598         /*
 599          * Synchronize so the TX path and rcu key iterators
 600          * can no longer be using this key before we free/remove it.
 601          */
 602         synchronize_net();
 603
 604         __ieee80211_key_destroy(key, delay_tailroom);
 605 }
 606
 607 void ieee80211_key_free_unused(struct ieee80211_key *key)
 608 {
 609         WARN_ON(key->sdata || key->local);
 610         ieee80211_key_free_common(key);
 611 }
 612
 613 static bool ieee80211_key_identical(struct ieee80211_sub_if_data *sdata,
 614                                     struct ieee80211_key *old,
 615                                     struct ieee80211_key *new)
 616 {
 617         u8 tkip_old[WLAN_KEY_LEN_TKIP], tkip_new[WLAN_KEY_LEN_TKIP];
 618         u8 *tk_old, *tk_new;
 619
 620         if (!old || new->conf.keylen != old->conf.keylen)
 621                 return false;
 622
 623         tk_old = old->conf.key;
 624         tk_new = new->conf.key;
 625
 626         /*
 627          * In station mode, don't compare the TX MIC key, as it's never used
 628          * and offloaded rekeying may not care to send it to the host. This
 629          * is the case in iwlwifi, for example.
 630          */
 631         if (sdata->vif.type == NL80211_IFTYPE_STATION &&
 632             new->conf.cipher == WLAN_CIPHER_SUITE_TKIP &&
 633             new->conf.keylen == WLAN_KEY_LEN_TKIP &&
 634             !(new->conf.flags & IEEE80211_KEY_FLAG_PAIRWISE)) {
 635                 memcpy(tkip_old, tk_old, WLAN_KEY_LEN_TKIP);
 636                 memcpy(tkip_new, tk_new, WLAN_KEY_LEN_TKIP);
 637                 memset(tkip_old + NL80211_TKIP_DATA_OFFSET_TX_MIC_KEY, 0, 8);
 638                 memset(tkip_new + NL80211_TKIP_DATA_OFFSET_TX_MIC_KEY, 0, 8);
 639                 tk_old = tkip_old;
 640                 tk_new = tkip_new;
 641         }
 642
 643         return !crypto_memneq(tk_old, tk_new, new->conf.keylen);
 644 }
 645
 646 int ieee80211_key_link(struct ieee80211_key *key,
 647                        struct ieee80211_sub_if_data *sdata,
 648                        struct sta_info *sta)
 649 {
 650         struct ieee80211_local *local = sdata->local;
 651         static atomic_t key_color = ATOMIC_INIT(0);
 652         struct ieee80211_key *old_key;
 653         int idx = key->conf.keyidx;
 654         bool pairwise = key->conf.flags & IEEE80211_KEY_FLAG_PAIRWISE;
 655         /*
 656          * We want to delay tailroom updates only for station - in that
 657          * case it helps roaming speed, but in other cases it hurts and
 658          * can cause warnings to appear.
 659          */
 660         bool delay_tailroom = sdata->vif.type == NL80211_IFTYPE_STATION;
 661         int ret;
 662
 663         /*
 664          * Assign a unique ID to every key so we can easily prevent mixed
 665          * key and fragment cache attacks.
 666          */
 667         key->color = atomic_inc_return(&key_color);
 668
 669         mutex_lock(&sdata->local->key_mtx);
 670
 671         if (sta && pairwise)
 672                 old_key = key_mtx_dereference(sdata->local, sta->ptk[idx]);
 673         else if (sta)
 674                 old_key = key_mtx_dereference(sdata->local, sta->gtk[idx]);
 675         else
 676                 old_key = key_mtx_dereference(sdata->local, sdata->keys[idx]);
 677
 678         /*
 679          * Silently accept key re-installation without really installing the
 680          * new version of the key to avoid nonce reuse or replay issues.
 681          */
 682         if (ieee80211_key_identical(sdata, old_key, key)) {
 683                 ieee80211_key_free_unused(key);
 684                 ret = 0;
 685                 goto out;
 686         }
 687
 688         key->local = sdata->local;
 689         key->sdata = sdata;
 690         key->sta = sta;
 691
 692         increment_tailroom_need_count(sdata);
 693
 694         ieee80211_key_replace(sdata, sta, pairwise, old_key, key);
 695         ieee80211_key_destroy(old_key, delay_tailroom);
 696
 697         ieee80211_debugfs_key_add(key);
 698
 699         if (!local->wowlan) {
 700                 ret = ieee80211_key_enable_hw_accel(key);
 701                 if (ret)
 702                         ieee80211_key_free(key, delay_tailroom);
 703         } else {
 704                 ret = 0;
 705         }
 706
 707  out:
 708         mutex_unlock(&sdata->local->key_mtx);
 709
 710         return ret;
 711 }
 712
 713 void ieee80211_key_free(struct ieee80211_key *key, bool delay_tailroom)
 714 {
 715         if (!key)
 716                 return;
 717
 718         /*
 719          * Replace key with nothingness if it was ever used.
 720          */
 721         if (key->sdata)
 722                 ieee80211_key_replace(key->sdata, key->sta,
 723                                 key->conf.flags & IEEE80211_KEY_FLAG_PAIRWISE,
 724                                 key, NULL);
 725         ieee80211_key_destroy(key, delay_tailroom);
 726 }
 727
 728 void ieee80211_enable_keys(struct ieee80211_sub_if_data *sdata)
 729 {
 730         struct ieee80211_key *key;
 731         struct ieee80211_sub_if_data *vlan;
 732
 733         ASSERT_RTNL();
 734
 735         if (WARN_ON(!ieee80211_sdata_running(sdata)))
 736                 return;
 737
 738         mutex_lock(&sdata->local->key_mtx);
 739
 740         WARN_ON_ONCE(sdata->crypto_tx_tailroom_needed_cnt ||
 741                      sdata->crypto_tx_tailroom_pending_dec);
 742
 743         if (sdata->vif.type == NL80211_IFTYPE_AP) {
 744                 list_for_each_entry(vlan, &sdata->u.ap.vlans, u.vlan.list)
 745                         WARN_ON_ONCE(vlan->crypto_tx_tailroom_needed_cnt ||
 746                                      vlan->crypto_tx_tailroom_pending_dec);
 747         }
 748
 749         list_for_each_entry(key, &sdata->key_list, list) {
 750                 increment_tailroom_need_count(sdata);
 751                 ieee80211_key_enable_hw_accel(key);
 752         }
 753
 754         mutex_unlock(&sdata->local->key_mtx);
 755 }
 756
 757 void ieee80211_reset_crypto_tx_tailroom(struct ieee80211_sub_if_data *sdata)
 758 {
 759         struct ieee80211_sub_if_data *vlan;
 760
 761         mutex_lock(&sdata->local->key_mtx);
 762
 763         sdata->crypto_tx_tailroom_needed_cnt = 0;
 764
 765         if (sdata->vif.type == NL80211_IFTYPE_AP) {
 766                 list_for_each_entry(vlan, &sdata->u.ap.vlans, u.vlan.list)
 767                         vlan->crypto_tx_tailroom_needed_cnt = 0;
 768         }
 769
 770         mutex_unlock(&sdata->local->key_mtx);
 771 }
 772
 773 void ieee80211_iter_keys(struct ieee80211_hw *hw,
 774                          struct ieee80211_vif *vif,
 775                          void (*iter)(struct ieee80211_hw *hw,
 776                                       struct ieee80211_vif *vif,
 777                                       struct ieee80211_sta *sta,
 778                                       struct ieee80211_key_conf *key,
 779                                       void *data),
 780                          void *iter_data)
 781 {
 782         struct ieee80211_local *local = hw_to_local(hw);
 783         struct ieee80211_key *key, *tmp;
 784         struct ieee80211_sub_if_data *sdata;
 785
 786         ASSERT_RTNL();
 787
 788         mutex_lock(&local->key_mtx);
 789         if (vif) {
 790                 sdata = vif_to_sdata(vif);
 791                 list_for_each_entry_safe(key, tmp, &sdata->key_list, list)
 792                         iter(hw, &sdata->vif,
 793                              key->sta ? &key->sta->sta : NULL,
 794                              &key->conf, iter_data);
 795         } else {
 796                 list_for_each_entry(sdata, &local->interfaces, list)
 797                         list_for_each_entry_safe(key, tmp,
 798                                                  &sdata->key_list, list)
 799                                 iter(hw, &sdata->vif,
 800                                      key->sta ? &key->sta->sta : NULL,
 801                                      &key->conf, iter_data);
 802         }
 803         mutex_unlock(&local->key_mtx);
 804 }
 805 EXPORT_SYMBOL(ieee80211_iter_keys);
 806
 807 static void
 808 _ieee80211_iter_keys_rcu(struct ieee80211_hw *hw,
 809                          struct ieee80211_sub_if_data *sdata,
 810                          void (*iter)(struct ieee80211_hw *hw,
 811                                       struct ieee80211_vif *vif,
 812                                       struct ieee80211_sta *sta,
 813                                       struct ieee80211_key_conf *key,
 814                                       void *data),
 815                          void *iter_data)
 816 {
 817         struct ieee80211_key *key;
 818
 819         list_for_each_entry_rcu(key, &sdata->key_list, list) {
 820                 /* skip keys of station in removal process */
 821                 if (key->sta && key->sta->removed)
 822                         continue;
 823                 if (!(key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE))
 824                         continue;
 825
 826                 iter(hw, &sdata->vif,
 827                      key->sta ? &key->sta->sta : NULL,
 828                      &key->conf, iter_data);
 829         }
 830 }
 831
 832 void ieee80211_iter_keys_rcu(struct ieee80211_hw *hw,
 833                              struct ieee80211_vif *vif,
 834                              void (*iter)(struct ieee80211_hw *hw,
 835                                           struct ieee80211_vif *vif,
 836                                           struct ieee80211_sta *sta,
 837                                           struct ieee80211_key_conf *key,
 838                                           void *data),
 839                              void *iter_data)
 840 {
 841         struct ieee80211_local *local = hw_to_local(hw);
 842         struct ieee80211_sub_if_data *sdata;
 843
 844         if (vif) {
 845                 sdata = vif_to_sdata(vif);
 846                 _ieee80211_iter_keys_rcu(hw, sdata, iter, iter_data);
 847         } else {
 848                 list_for_each_entry_rcu(sdata, &local->interfaces, list)
 849                         _ieee80211_iter_keys_rcu(hw, sdata, iter, iter_data);
 850         }
 851 }
 852 EXPORT_SYMBOL(ieee80211_iter_keys_rcu);
 853
 854 static void ieee80211_free_keys_iface(struct ieee80211_sub_if_data *sdata,
 855                                       struct list_head *keys)
 856 {
 857         struct ieee80211_key *key, *tmp;
 858
 859         decrease_tailroom_need_count(sdata,
 860                                      sdata->crypto_tx_tailroom_pending_dec);
 861         sdata->crypto_tx_tailroom_pending_dec = 0;
 862
 863         ieee80211_debugfs_key_remove_mgmt_default(sdata);
 864
 865         list_for_each_entry_safe(key, tmp, &sdata->key_list, list) {
 866                 ieee80211_key_replace(key->sdata, key->sta,
 867                                 key->conf.flags & IEEE80211_KEY_FLAG_PAIRWISE,
 868                                 key, NULL);
 869                 list_add_tail(&key->list, keys);
 870         }
 871
 872         ieee80211_debugfs_key_update_default(sdata);
 873 }
 874
 875 void ieee80211_free_keys(struct ieee80211_sub_if_data *sdata,
 876                          bool force_synchronize)
 877 {
 878         struct ieee80211_local *local = sdata->local;
 879         struct ieee80211_sub_if_data *vlan;
 880         struct ieee80211_sub_if_data *master;
 881         struct ieee80211_key *key, *tmp;
 882         LIST_HEAD(keys);
 883
 884         cancel_delayed_work_sync(&sdata->dec_tailroom_needed_wk);
 885
 886         mutex_lock(&local->key_mtx);
 887
 888         ieee80211_free_keys_iface(sdata, &keys);
 889
 890         if (sdata->vif.type == NL80211_IFTYPE_AP) {
 891                 list_for_each_entry(vlan, &sdata->u.ap.vlans, u.vlan.list)
 892                         ieee80211_free_keys_iface(vlan, &keys);
 893         }
 894
 895         if (!list_empty(&keys) || force_synchronize)
 896                 synchronize_net();
 897         list_for_each_entry_safe(key, tmp, &keys, list)
 898                 __ieee80211_key_destroy(key, false);
 899
 900         if (sdata->vif.type == NL80211_IFTYPE_AP_VLAN) {
 901                 if (sdata->bss) {
 902                         master = container_of(sdata->bss,
 903                                               struct ieee80211_sub_if_data,
 904                                               u.ap);
 905
 906                         WARN_ON_ONCE(sdata->crypto_tx_tailroom_needed_cnt !=
 907                                      master->crypto_tx_tailroom_needed_cnt);
 908                 }
 909         } else {
 910                 WARN_ON_ONCE(sdata->crypto_tx_tailroom_needed_cnt ||
 911                              sdata->crypto_tx_tailroom_pending_dec);
 912         }
 913
 914         if (sdata->vif.type == NL80211_IFTYPE_AP) {
 915                 list_for_each_entry(vlan, &sdata->u.ap.vlans, u.vlan.list)
 916                         WARN_ON_ONCE(vlan->crypto_tx_tailroom_needed_cnt ||
 917                                      vlan->crypto_tx_tailroom_pending_dec);
 918         }
 919
 920         mutex_unlock(&local->key_mtx);
 921 }
 922
 923 void ieee80211_free_sta_keys(struct ieee80211_local *local,
 924                              struct sta_info *sta)
 925 {
 926         struct ieee80211_key *key;
 927         int i;
 928
 929         mutex_lock(&local->key_mtx);
 930         for (i = 0; i < ARRAY_SIZE(sta->gtk); i++) {
 931                 key = key_mtx_dereference(local, sta->gtk[i]);
 932                 if (!key)
 933                         continue;
 934                 ieee80211_key_replace(key->sdata, key->sta,
 935                                 key->conf.flags & IEEE80211_KEY_FLAG_PAIRWISE,
 936                                 key, NULL);
 937                 __ieee80211_key_destroy(key, key->sdata->vif.type ==
 938                                         NL80211_IFTYPE_STATION);
 939         }
 940
 941         for (i = 0; i < NUM_DEFAULT_KEYS; i++) {
 942                 key = key_mtx_dereference(local, sta->ptk[i]);
 943                 if (!key)
 944                         continue;
 945                 ieee80211_key_replace(key->sdata, key->sta,
 946                                 key->conf.flags & IEEE80211_KEY_FLAG_PAIRWISE,
 947                                 key, NULL);
 948                 __ieee80211_key_destroy(key, key->sdata->vif.type ==
 949                                         NL80211_IFTYPE_STATION);
 950         }
 951
 952         mutex_unlock(&local->key_mtx);
 953 }
 954
 955 void ieee80211_delayed_tailroom_dec(struct work_struct *wk)
 956 {
 957         struct ieee80211_sub_if_data *sdata;
 958
 959         sdata = container_of(wk, struct ieee80211_sub_if_data,
 960                              dec_tailroom_needed_wk.work);
 961
 962         /*
 963          * The reason for the delayed tailroom needed decrementing is to
 964          * make roaming faster: during roaming, all keys are first deleted
 965          * and then new keys are installed. The first new key causes the
 966          * crypto_tx_tailroom_needed_cnt to go from 0 to 1, which invokes
 967          * the cost of synchronize_net() (which can be slow). Avoid this
 968          * by deferring the crypto_tx_tailroom_needed_cnt decrementing on
 969          * key removal for a while, so if we roam the value is larger than
 970          * zero and no 0->1 transition happens.
 971          *
 972          * The cost is that if the AP switching was from an AP with keys
 973          * to one without, we still allocate tailroom while it would no
 974          * longer be needed. However, in the typical (fast) roaming case
 975          * within an ESS this usually won't happen.
 976          */
 977
 978         mutex_lock(&sdata->local->key_mtx);
 979         decrease_tailroom_need_count(sdata,
 980                                      sdata->crypto_tx_tailroom_pending_dec);
 981         sdata->crypto_tx_tailroom_pending_dec = 0;
 982         mutex_unlock(&sdata->local->key_mtx);
 983 }
 984
 985 void ieee80211_gtk_rekey_notify(struct ieee80211_vif *vif, const u8 *bssid,
 986                                 const u8 *replay_ctr, gfp_t gfp)
 987 {
 988         struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
 989
 990         trace_api_gtk_rekey_notify(sdata, bssid, replay_ctr);
 991
 992         cfg80211_gtk_rekey_notify(sdata->dev, bssid, replay_ctr, gfp);
 993 }
 994 EXPORT_SYMBOL_GPL(ieee80211_gtk_rekey_notify);
 995
 996 void ieee80211_get_key_rx_seq(struct ieee80211_key_conf *keyconf,
 997                               int tid, struct ieee80211_key_seq *seq)
 998 {
 999         struct ieee80211_key *key;
1000         const u8 *pn;
1001
1002         key = container_of(keyconf, struct ieee80211_key, conf);
1003
1004         switch (key->conf.cipher) {
1005         case WLAN_CIPHER_SUITE_TKIP:
1006                 if (WARN_ON(tid < 0 || tid >= IEEE80211_NUM_TIDS))
1007                         return;
1008                 seq->tkip.iv32 = key->u.tkip.rx[tid].iv32;
1009                 seq->tkip.iv16 = key->u.tkip.rx[tid].iv16;
1010                 break;
1011         case WLAN_CIPHER_SUITE_CCMP:
1012         case WLAN_CIPHER_SUITE_CCMP_256:
1013                 if (WARN_ON(tid < -1 || tid >= IEEE80211_NUM_TIDS))
1014                         return;
1015                 if (tid < 0)
1016                         pn = key->u.ccmp.rx_pn[IEEE80211_NUM_TIDS];
1017                 else
1018                         pn = key->u.ccmp.rx_pn[tid];
1019                 memcpy(seq->ccmp.pn, pn, IEEE80211_CCMP_PN_LEN);
1020                 break;
1021         case WLAN_CIPHER_SUITE_AES_CMAC:
1022         case WLAN_CIPHER_SUITE_BIP_CMAC_256:
1023                 if (WARN_ON(tid != 0))
1024                         return;
1025                 pn = key->u.aes_cmac.rx_pn;
1026                 memcpy(seq->aes_cmac.pn, pn, IEEE80211_CMAC_PN_LEN);
1027                 break;
1028         case WLAN_CIPHER_SUITE_BIP_GMAC_128:
1029         case WLAN_CIPHER_SUITE_BIP_GMAC_256:
1030                 if (WARN_ON(tid != 0))
1031                         return;
1032                 pn = key->u.aes_gmac.rx_pn;
1033                 memcpy(seq->aes_gmac.pn, pn, IEEE80211_GMAC_PN_LEN);
1034                 break;
1035         case WLAN_CIPHER_SUITE_GCMP:
1036         case WLAN_CIPHER_SUITE_GCMP_256:
1037                 if (WARN_ON(tid < -1 || tid >= IEEE80211_NUM_TIDS))
1038                         return;
1039                 if (tid < 0)
1040                         pn = key->u.gcmp.rx_pn[IEEE80211_NUM_TIDS];
1041                 else
1042                         pn = key->u.gcmp.rx_pn[tid];
1043                 memcpy(seq->gcmp.pn, pn, IEEE80211_GCMP_PN_LEN);
1044                 break;
1045         }
1046 }
1047 EXPORT_SYMBOL(ieee80211_get_key_rx_seq);
1048
1049 void ieee80211_set_key_rx_seq(struct ieee80211_key_conf *keyconf,
1050                               int tid, struct ieee80211_key_seq *seq)
1051 {
1052         struct ieee80211_key *key;
1053         u8 *pn;
1054
1055         key = container_of(keyconf, struct ieee80211_key, conf);
1056
1057         switch (key->conf.cipher) {
1058         case WLAN_CIPHER_SUITE_TKIP:
1059                 if (WARN_ON(tid < 0 || tid >= IEEE80211_NUM_TIDS))
1060                         return;
1061                 key->u.tkip.rx[tid].iv32 = seq->tkip.iv32;
1062                 key->u.tkip.rx[tid].iv16 = seq->tkip.iv16;
1063                 break;
1064         case WLAN_CIPHER_SUITE_CCMP:
1065         case WLAN_CIPHER_SUITE_CCMP_256:
1066                 if (WARN_ON(tid < -1 || tid >= IEEE80211_NUM_TIDS))
1067                         return;
1068                 if (tid < 0)
1069                         pn = key->u.ccmp.rx_pn[IEEE80211_NUM_TIDS];
1070                 else
1071                         pn = key->u.ccmp.rx_pn[tid];
1072                 memcpy(pn, seq->ccmp.pn, IEEE80211_CCMP_PN_LEN);
1073                 break;
1074         case WLAN_CIPHER_SUITE_AES_CMAC:
1075         case WLAN_CIPHER_SUITE_BIP_CMAC_256:
1076                 if (WARN_ON(tid != 0))
1077                         return;
1078                 pn = key->u.aes_cmac.rx_pn;
1079                 memcpy(pn, seq->aes_cmac.pn, IEEE80211_CMAC_PN_LEN);
1080                 break;
1081         case WLAN_CIPHER_SUITE_BIP_GMAC_128:
1082         case WLAN_CIPHER_SUITE_BIP_GMAC_256:
1083                 if (WARN_ON(tid != 0))
1084                         return;
1085                 pn = key->u.aes_gmac.rx_pn;
1086                 memcpy(pn, seq->aes_gmac.pn, IEEE80211_GMAC_PN_LEN);
1087                 break;
1088         case WLAN_CIPHER_SUITE_GCMP:
1089         case WLAN_CIPHER_SUITE_GCMP_256:
1090                 if (WARN_ON(tid < -1 || tid >= IEEE80211_NUM_TIDS))
1091                         return;
1092                 if (tid < 0)
1093                         pn = key->u.gcmp.rx_pn[IEEE80211_NUM_TIDS];
1094                 else
1095                         pn = key->u.gcmp.rx_pn[tid];
1096                 memcpy(pn, seq->gcmp.pn, IEEE80211_GCMP_PN_LEN);
1097                 break;
1098         default:
1099                 WARN_ON(1);
1100                 break;
1101         }
1102 }
1103 EXPORT_SYMBOL_GPL(ieee80211_set_key_rx_seq);
1104
1105 void ieee80211_remove_key(struct ieee80211_key_conf *keyconf)
1106 {
1107         struct ieee80211_key *key;
1108
1109         key = container_of(keyconf, struct ieee80211_key, conf);
1110
1111         assert_key_lock(key->local);
1112
1113         /*
1114          * if key was uploaded, we assume the driver will/has remove(d)
1115          * it, so adjust bookkeeping accordingly
1116          */
1117         if (key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE) {
1118                 key->flags &= ~KEY_FLAG_UPLOADED_TO_HARDWARE;
1119
1120                 if (!((key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_MMIC) ||
1121                       (key->conf.flags & IEEE80211_KEY_FLAG_RESERVE_TAILROOM)))
1122                         increment_tailroom_need_count(key->sdata);
1123         }
1124
1125         ieee80211_key_free(key, false);
1126 }
1127 EXPORT_SYMBOL_GPL(ieee80211_remove_key);
1128
1129 struct ieee80211_key_conf *
1130 ieee80211_gtk_rekey_add(struct ieee80211_vif *vif,
1131                         struct ieee80211_key_conf *keyconf)
1132 {
1133         struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
1134         struct ieee80211_local *local = sdata->local;
1135         struct ieee80211_key *key;
1136         int err;
1137
1138         if (WARN_ON(!local->wowlan))
1139                 return ERR_PTR(-EINVAL);
1140
1141         if (WARN_ON(vif->type != NL80211_IFTYPE_STATION))
1142                 return ERR_PTR(-EINVAL);
1143
1144         key = ieee80211_key_alloc(keyconf->cipher, keyconf->keyidx,
1145                                   keyconf->keylen, keyconf->key,
1146                                   0, NULL, NULL);
1147         if (IS_ERR(key))
1148                 return ERR_CAST(key);
1149
1150         if (sdata->u.mgd.mfp != IEEE80211_MFP_DISABLED)
1151                 key->conf.flags |= IEEE80211_KEY_FLAG_RX_MGMT;
1152
1153         err = ieee80211_key_link(key, sdata, NULL);
1154         if (err)
1155                 return ERR_PTR(err);
1156
1157         return &key->conf;
1158 }
1159 EXPORT_SYMBOL_GPL(ieee80211_gtk_rekey_add);