kernel/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                 }
 340         } else {
 341                 defunikey = old &&
 342                         old == key_mtx_dereference(sdata->local,
 343                                                 sdata->default_unicast_key);
 344                 defmultikey = old &&
 345                         old == key_mtx_dereference(sdata->local,
 346                                                 sdata->default_multicast_key);
 347                 defmgmtkey = old &&
 348                         old == key_mtx_dereference(sdata->local,
 349                                                 sdata->default_mgmt_key);
 350
 351                 if (defunikey && !new)
 352                         __ieee80211_set_default_key(sdata, -1, true, false);
 353                 if (defmultikey && !new)
 354                         __ieee80211_set_default_key(sdata, -1, false, true);
 355                 if (defmgmtkey && !new)
 356                         __ieee80211_set_default_mgmt_key(sdata, -1);
 357
 358                 rcu_assign_pointer(sdata->keys[idx], new);
 359                 if (defunikey && new)
 360                         __ieee80211_set_default_key(sdata, new->conf.keyidx,
 361                                                     true, false);
 362                 if (defmultikey && new)
 363                         __ieee80211_set_default_key(sdata, new->conf.keyidx,
 364                                                     false, true);
 365                 if (defmgmtkey && new)
 366                         __ieee80211_set_default_mgmt_key(sdata,
 367                                                          new->conf.keyidx);
 368         }
 369
 370         if (old)
 371                 list_del(&old->list);
 372 }
 373
 374 struct ieee80211_key *
 375 ieee80211_key_alloc(u32 cipher, int idx, size_t key_len,
 376                     const u8 *key_data,
 377                     size_t seq_len, const u8 *seq,
 378                     const struct ieee80211_cipher_scheme *cs)
 379 {
 380         struct ieee80211_key *key;
 381         int i, j, err;
 382
 383         if (WARN_ON(idx < 0 || idx >= NUM_DEFAULT_KEYS + NUM_DEFAULT_MGMT_KEYS))
 384                 return ERR_PTR(-EINVAL);
 385
 386         key = kzalloc(sizeof(struct ieee80211_key) + key_len, GFP_KERNEL);
 387         if (!key)
 388                 return ERR_PTR(-ENOMEM);
 389
 390         /*
 391          * Default to software encryption; we'll later upload the
 392          * key to the hardware if possible.
 393          */
 394         key->conf.flags = 0;
 395         key->flags = 0;
 396
 397         key->conf.cipher = cipher;
 398         key->conf.keyidx = idx;
 399         key->conf.keylen = key_len;
 400         switch (cipher) {
 401         case WLAN_CIPHER_SUITE_WEP40:
 402         case WLAN_CIPHER_SUITE_WEP104:
 403                 key->conf.iv_len = IEEE80211_WEP_IV_LEN;
 404                 key->conf.icv_len = IEEE80211_WEP_ICV_LEN;
 405                 break;
 406         case WLAN_CIPHER_SUITE_TKIP:
 407                 key->conf.iv_len = IEEE80211_TKIP_IV_LEN;
 408                 key->conf.icv_len = IEEE80211_TKIP_ICV_LEN;
 409                 if (seq) {
 410                         for (i = 0; i < IEEE80211_NUM_TIDS; i++) {
 411                                 key->u.tkip.rx[i].iv32 =
 412                                         get_unaligned_le32(&seq[2]);
 413                                 key->u.tkip.rx[i].iv16 =
 414                                         get_unaligned_le16(seq);
 415                         }
 416                 }
 417                 spin_lock_init(&key->u.tkip.txlock);
 418                 break;
 419         case WLAN_CIPHER_SUITE_CCMP:
 420                 key->conf.iv_len = IEEE80211_CCMP_HDR_LEN;
 421                 key->conf.icv_len = IEEE80211_CCMP_MIC_LEN;
 422                 if (seq) {
 423                         for (i = 0; i < IEEE80211_NUM_TIDS + 1; i++)
 424                                 for (j = 0; j < IEEE80211_CCMP_PN_LEN; j++)
 425                                         key->u.ccmp.rx_pn[i][j] =
 426                                                 seq[IEEE80211_CCMP_PN_LEN - j - 1];
 427                 }
 428                 /*
 429                  * Initialize AES key state here as an optimization so that
 430                  * it does not need to be initialized for every packet.
 431                  */
 432                 key->u.ccmp.tfm = ieee80211_aes_key_setup_encrypt(
 433                         key_data, key_len, IEEE80211_CCMP_MIC_LEN);
 434                 if (IS_ERR(key->u.ccmp.tfm)) {
 435                         err = PTR_ERR(key->u.ccmp.tfm);
 436                         kfree(key);
 437                         return ERR_PTR(err);
 438                 }
 439                 break;
 440         case WLAN_CIPHER_SUITE_CCMP_256:
 441                 key->conf.iv_len = IEEE80211_CCMP_256_HDR_LEN;
 442                 key->conf.icv_len = IEEE80211_CCMP_256_MIC_LEN;
 443                 for (i = 0; seq && i < IEEE80211_NUM_TIDS + 1; i++)
 444                         for (j = 0; j < IEEE80211_CCMP_256_PN_LEN; j++)
 445                                 key->u.ccmp.rx_pn[i][j] =
 446                                         seq[IEEE80211_CCMP_256_PN_LEN - j - 1];
 447                 /* Initialize AES key state here as an optimization so that
 448                  * it does not need to be initialized for every packet.
 449                  */
 450                 key->u.ccmp.tfm = ieee80211_aes_key_setup_encrypt(
 451                         key_data, key_len, IEEE80211_CCMP_256_MIC_LEN);
 452                 if (IS_ERR(key->u.ccmp.tfm)) {
 453                         err = PTR_ERR(key->u.ccmp.tfm);
 454                         kfree(key);
 455                         return ERR_PTR(err);
 456                 }
 457                 break;
 458         case WLAN_CIPHER_SUITE_AES_CMAC:
 459         case WLAN_CIPHER_SUITE_BIP_CMAC_256:
 460                 key->conf.iv_len = 0;
 461                 if (cipher == WLAN_CIPHER_SUITE_AES_CMAC)
 462                         key->conf.icv_len = sizeof(struct ieee80211_mmie);
 463                 else
 464                         key->conf.icv_len = sizeof(struct ieee80211_mmie_16);
 465                 if (seq)
 466                         for (j = 0; j < IEEE80211_CMAC_PN_LEN; j++)
 467                                 key->u.aes_cmac.rx_pn[j] =
 468                                         seq[IEEE80211_CMAC_PN_LEN - j - 1];
 469                 /*
 470                  * Initialize AES key state here as an optimization so that
 471                  * it does not need to be initialized for every packet.
 472                  */
 473                 key->u.aes_cmac.tfm =
 474                         ieee80211_aes_cmac_key_setup(key_data, key_len);
 475                 if (IS_ERR(key->u.aes_cmac.tfm)) {
 476                         err = PTR_ERR(key->u.aes_cmac.tfm);
 477                         kfree(key);
 478                         return ERR_PTR(err);
 479                 }
 480                 break;
 481         case WLAN_CIPHER_SUITE_BIP_GMAC_128:
 482         case WLAN_CIPHER_SUITE_BIP_GMAC_256:
 483                 key->conf.iv_len = 0;
 484                 key->conf.icv_len = sizeof(struct ieee80211_mmie_16);
 485                 if (seq)
 486                         for (j = 0; j < IEEE80211_GMAC_PN_LEN; j++)
 487                                 key->u.aes_gmac.rx_pn[j] =
 488                                         seq[IEEE80211_GMAC_PN_LEN - j - 1];
 489                 /* Initialize AES key state here as an optimization so that
 490                  * it does not need to be initialized for every packet.
 491                  */
 492                 key->u.aes_gmac.tfm =
 493                         ieee80211_aes_gmac_key_setup(key_data, key_len);
 494                 if (IS_ERR(key->u.aes_gmac.tfm)) {
 495                         err = PTR_ERR(key->u.aes_gmac.tfm);
 496                         kfree(key);
 497                         return ERR_PTR(err);
 498                 }
 499                 break;
 500         case WLAN_CIPHER_SUITE_GCMP:
 501         case WLAN_CIPHER_SUITE_GCMP_256:
 502                 key->conf.iv_len = IEEE80211_GCMP_HDR_LEN;
 503                 key->conf.icv_len = IEEE80211_GCMP_MIC_LEN;
 504                 for (i = 0; seq && i < IEEE80211_NUM_TIDS + 1; i++)
 505                         for (j = 0; j < IEEE80211_GCMP_PN_LEN; j++)
 506                                 key->u.gcmp.rx_pn[i][j] =
 507                                         seq[IEEE80211_GCMP_PN_LEN - j - 1];
 508                 /* Initialize AES key state here as an optimization so that
 509                  * it does not need to be initialized for every packet.
 510                  */
 511                 key->u.gcmp.tfm = ieee80211_aes_gcm_key_setup_encrypt(key_data,
 512                                                                       key_len);
 513                 if (IS_ERR(key->u.gcmp.tfm)) {
 514                         err = PTR_ERR(key->u.gcmp.tfm);
 515                         kfree(key);
 516                         return ERR_PTR(err);
 517                 }
 518                 break;
 519         default:
 520                 if (cs) {
 521                         if (seq_len && seq_len != cs->pn_len) {
 522                                 kfree(key);
 523                                 return ERR_PTR(-EINVAL);
 524                         }
 525
 526                         key->conf.iv_len = cs->hdr_len;
 527                         key->conf.icv_len = cs->mic_len;
 528                         for (i = 0; i < IEEE80211_NUM_TIDS + 1; i++)
 529                                 for (j = 0; j < seq_len; j++)
 530                                         key->u.gen.rx_pn[i][j] =
 531                                                         seq[seq_len - j - 1];
 532                         key->flags |= KEY_FLAG_CIPHER_SCHEME;
 533                 }
 534         }
 535         memcpy(key->conf.key, key_data, key_len);
 536         INIT_LIST_HEAD(&key->list);
 537
 538         return key;
 539 }
 540
 541 static void ieee80211_key_free_common(struct ieee80211_key *key)
 542 {
 543         switch (key->conf.cipher) {
 544         case WLAN_CIPHER_SUITE_CCMP:
 545         case WLAN_CIPHER_SUITE_CCMP_256:
 546                 ieee80211_aes_key_free(key->u.ccmp.tfm);
 547                 break;
 548         case WLAN_CIPHER_SUITE_AES_CMAC:
 549         case WLAN_CIPHER_SUITE_BIP_CMAC_256:
 550                 ieee80211_aes_cmac_key_free(key->u.aes_cmac.tfm);
 551                 break;
 552         case WLAN_CIPHER_SUITE_BIP_GMAC_128:
 553         case WLAN_CIPHER_SUITE_BIP_GMAC_256:
 554                 ieee80211_aes_gmac_key_free(key->u.aes_gmac.tfm);
 555                 break;
 556         case WLAN_CIPHER_SUITE_GCMP:
 557         case WLAN_CIPHER_SUITE_GCMP_256:
 558                 ieee80211_aes_gcm_key_free(key->u.gcmp.tfm);
 559                 break;
 560         }
 561         kzfree(key);
 562 }
 563
 564 static void __ieee80211_key_destroy(struct ieee80211_key *key,
 565                                     bool delay_tailroom)
 566 {
 567         if (key->local)
 568                 ieee80211_key_disable_hw_accel(key);
 569
 570         if (key->local) {
 571                 struct ieee80211_sub_if_data *sdata = key->sdata;
 572
 573                 ieee80211_debugfs_key_remove(key);
 574
 575                 if (delay_tailroom) {
 576                         /* see ieee80211_delayed_tailroom_dec */
 577                         sdata->crypto_tx_tailroom_pending_dec++;
 578                         schedule_delayed_work(&sdata->dec_tailroom_needed_wk,
 579                                               HZ/2);
 580                 } else {
 581                         decrease_tailroom_need_count(sdata, 1);
 582                 }
 583         }
 584
 585         ieee80211_key_free_common(key);
 586 }
 587
 588 static void ieee80211_key_destroy(struct ieee80211_key *key,
 589                                   bool delay_tailroom)
 590 {
 591         if (!key)
 592                 return;
 593
 594         /*
 595          * Synchronize so the TX path can no longer be using
 596          * this key before we free/remove it.
 597          */
 598         synchronize_net();
 599
 600         __ieee80211_key_destroy(key, delay_tailroom);
 601 }
 602
 603 void ieee80211_key_free_unused(struct ieee80211_key *key)
 604 {
 605         WARN_ON(key->sdata || key->local);
 606         ieee80211_key_free_common(key);
 607 }
 608
 609 int ieee80211_key_link(struct ieee80211_key *key,
 610                        struct ieee80211_sub_if_data *sdata,
 611                        struct sta_info *sta)
 612 {
 613         struct ieee80211_local *local = sdata->local;
 614         struct ieee80211_key *old_key;
 615         int idx, ret;
 616         bool pairwise;
 617
 618         pairwise = key->conf.flags & IEEE80211_KEY_FLAG_PAIRWISE;
 619         idx = key->conf.keyidx;
 620         key->local = sdata->local;
 621         key->sdata = sdata;
 622         key->sta = sta;
 623
 624         mutex_lock(&sdata->local->key_mtx);
 625
 626         if (sta && pairwise)
 627                 old_key = key_mtx_dereference(sdata->local, sta->ptk[idx]);
 628         else if (sta)
 629                 old_key = key_mtx_dereference(sdata->local, sta->gtk[idx]);
 630         else
 631                 old_key = key_mtx_dereference(sdata->local, sdata->keys[idx]);
 632
 633         increment_tailroom_need_count(sdata);
 634
 635         ieee80211_key_replace(sdata, sta, pairwise, old_key, key);
 636         ieee80211_key_destroy(old_key, true);
 637
 638         ieee80211_debugfs_key_add(key);
 639
 640         if (!local->wowlan) {
 641                 ret = ieee80211_key_enable_hw_accel(key);
 642                 if (ret)
 643                         ieee80211_key_free(key, true);
 644         } else {
 645                 ret = 0;
 646         }
 647
 648         mutex_unlock(&sdata->local->key_mtx);
 649
 650         return ret;
 651 }
 652
 653 void ieee80211_key_free(struct ieee80211_key *key, bool delay_tailroom)
 654 {
 655         if (!key)
 656                 return;
 657
 658         /*
 659          * Replace key with nothingness if it was ever used.
 660          */
 661         if (key->sdata)
 662                 ieee80211_key_replace(key->sdata, key->sta,
 663                                 key->conf.flags & IEEE80211_KEY_FLAG_PAIRWISE,
 664                                 key, NULL);
 665         ieee80211_key_destroy(key, delay_tailroom);
 666 }
 667
 668 void ieee80211_enable_keys(struct ieee80211_sub_if_data *sdata)
 669 {
 670         struct ieee80211_key *key;
 671         struct ieee80211_sub_if_data *vlan;
 672
 673         ASSERT_RTNL();
 674
 675         if (WARN_ON(!ieee80211_sdata_running(sdata)))
 676                 return;
 677
 678         mutex_lock(&sdata->local->key_mtx);
 679
 680         WARN_ON_ONCE(sdata->crypto_tx_tailroom_needed_cnt ||
 681                      sdata->crypto_tx_tailroom_pending_dec);
 682
 683         if (sdata->vif.type == NL80211_IFTYPE_AP) {
 684                 list_for_each_entry(vlan, &sdata->u.ap.vlans, u.vlan.list)
 685                         WARN_ON_ONCE(vlan->crypto_tx_tailroom_needed_cnt ||
 686                                      vlan->crypto_tx_tailroom_pending_dec);
 687         }
 688
 689         list_for_each_entry(key, &sdata->key_list, list) {
 690                 increment_tailroom_need_count(sdata);
 691                 ieee80211_key_enable_hw_accel(key);
 692         }
 693
 694         mutex_unlock(&sdata->local->key_mtx);
 695 }
 696
 697 void ieee80211_reset_crypto_tx_tailroom(struct ieee80211_sub_if_data *sdata)
 698 {
 699         struct ieee80211_sub_if_data *vlan;
 700
 701         mutex_lock(&sdata->local->key_mtx);
 702
 703         sdata->crypto_tx_tailroom_needed_cnt = 0;
 704
 705         if (sdata->vif.type == NL80211_IFTYPE_AP) {
 706                 list_for_each_entry(vlan, &sdata->u.ap.vlans, u.vlan.list)
 707                         vlan->crypto_tx_tailroom_needed_cnt = 0;
 708         }
 709
 710         mutex_unlock(&sdata->local->key_mtx);
 711 }
 712
 713 void ieee80211_iter_keys(struct ieee80211_hw *hw,
 714                          struct ieee80211_vif *vif,
 715                          void (*iter)(struct ieee80211_hw *hw,
 716                                       struct ieee80211_vif *vif,
 717                                       struct ieee80211_sta *sta,
 718                                       struct ieee80211_key_conf *key,
 719                                       void *data),
 720                          void *iter_data)
 721 {
 722         struct ieee80211_local *local = hw_to_local(hw);
 723         struct ieee80211_key *key, *tmp;
 724         struct ieee80211_sub_if_data *sdata;
 725
 726         ASSERT_RTNL();
 727
 728         mutex_lock(&local->key_mtx);
 729         if (vif) {
 730                 sdata = vif_to_sdata(vif);
 731                 list_for_each_entry_safe(key, tmp, &sdata->key_list, list)
 732                         iter(hw, &sdata->vif,
 733                              key->sta ? &key->sta->sta : NULL,
 734                              &key->conf, iter_data);
 735         } else {
 736                 list_for_each_entry(sdata, &local->interfaces, list)
 737                         list_for_each_entry_safe(key, tmp,
 738                                                  &sdata->key_list, list)
 739                                 iter(hw, &sdata->vif,
 740                                      key->sta ? &key->sta->sta : NULL,
 741                                      &key->conf, iter_data);
 742         }
 743         mutex_unlock(&local->key_mtx);
 744 }
 745 EXPORT_SYMBOL(ieee80211_iter_keys);
 746
 747 static void ieee80211_free_keys_iface(struct ieee80211_sub_if_data *sdata,
 748                                       struct list_head *keys)
 749 {
 750         struct ieee80211_key *key, *tmp;
 751
 752         decrease_tailroom_need_count(sdata,
 753                                      sdata->crypto_tx_tailroom_pending_dec);
 754         sdata->crypto_tx_tailroom_pending_dec = 0;
 755
 756         ieee80211_debugfs_key_remove_mgmt_default(sdata);
 757
 758         list_for_each_entry_safe(key, tmp, &sdata->key_list, list) {
 759                 ieee80211_key_replace(key->sdata, key->sta,
 760                                 key->conf.flags & IEEE80211_KEY_FLAG_PAIRWISE,
 761                                 key, NULL);
 762                 list_add_tail(&key->list, keys);
 763         }
 764
 765         ieee80211_debugfs_key_update_default(sdata);
 766 }
 767
 768 void ieee80211_free_keys(struct ieee80211_sub_if_data *sdata,
 769                          bool force_synchronize)
 770 {
 771         struct ieee80211_local *local = sdata->local;
 772         struct ieee80211_sub_if_data *vlan;
 773         struct ieee80211_sub_if_data *master;
 774         struct ieee80211_key *key, *tmp;
 775         LIST_HEAD(keys);
 776
 777         cancel_delayed_work_sync(&sdata->dec_tailroom_needed_wk);
 778
 779         mutex_lock(&local->key_mtx);
 780
 781         ieee80211_free_keys_iface(sdata, &keys);
 782
 783         if (sdata->vif.type == NL80211_IFTYPE_AP) {
 784                 list_for_each_entry(vlan, &sdata->u.ap.vlans, u.vlan.list)
 785                         ieee80211_free_keys_iface(vlan, &keys);
 786         }
 787
 788         if (!list_empty(&keys) || force_synchronize)
 789                 synchronize_net();
 790         list_for_each_entry_safe(key, tmp, &keys, list)
 791                 __ieee80211_key_destroy(key, false);
 792
 793         if (sdata->vif.type == NL80211_IFTYPE_AP_VLAN) {
 794                 if (sdata->bss) {
 795                         master = container_of(sdata->bss,
 796                                               struct ieee80211_sub_if_data,
 797                                               u.ap);
 798
 799                         WARN_ON_ONCE(sdata->crypto_tx_tailroom_needed_cnt !=
 800                                      master->crypto_tx_tailroom_needed_cnt);
 801                 }
 802         } else {
 803                 WARN_ON_ONCE(sdata->crypto_tx_tailroom_needed_cnt ||
 804                              sdata->crypto_tx_tailroom_pending_dec);
 805         }
 806
 807         if (sdata->vif.type == NL80211_IFTYPE_AP) {
 808                 list_for_each_entry(vlan, &sdata->u.ap.vlans, u.vlan.list)
 809                         WARN_ON_ONCE(vlan->crypto_tx_tailroom_needed_cnt ||
 810                                      vlan->crypto_tx_tailroom_pending_dec);
 811         }
 812
 813         mutex_unlock(&local->key_mtx);
 814 }
 815
 816 void ieee80211_free_sta_keys(struct ieee80211_local *local,
 817                              struct sta_info *sta)
 818 {
 819         struct ieee80211_key *key;
 820         int i;
 821
 822         mutex_lock(&local->key_mtx);
 823         for (i = 0; i < ARRAY_SIZE(sta->gtk); i++) {
 824                 key = key_mtx_dereference(local, sta->gtk[i]);
 825                 if (!key)
 826                         continue;
 827                 ieee80211_key_replace(key->sdata, key->sta,
 828                                 key->conf.flags & IEEE80211_KEY_FLAG_PAIRWISE,
 829                                 key, NULL);
 830                 __ieee80211_key_destroy(key, true);
 831         }
 832
 833         for (i = 0; i < NUM_DEFAULT_KEYS; i++) {
 834                 key = key_mtx_dereference(local, sta->ptk[i]);
 835                 if (!key)
 836                         continue;
 837                 ieee80211_key_replace(key->sdata, key->sta,
 838                                 key->conf.flags & IEEE80211_KEY_FLAG_PAIRWISE,
 839                                 key, NULL);
 840                 __ieee80211_key_destroy(key, true);
 841         }
 842
 843         mutex_unlock(&local->key_mtx);
 844 }
 845
 846 void ieee80211_delayed_tailroom_dec(struct work_struct *wk)
 847 {
 848         struct ieee80211_sub_if_data *sdata;
 849
 850         sdata = container_of(wk, struct ieee80211_sub_if_data,
 851                              dec_tailroom_needed_wk.work);
 852
 853         /*
 854          * The reason for the delayed tailroom needed decrementing is to
 855          * make roaming faster: during roaming, all keys are first deleted
 856          * and then new keys are installed. The first new key causes the
 857          * crypto_tx_tailroom_needed_cnt to go from 0 to 1, which invokes
 858          * the cost of synchronize_net() (which can be slow). Avoid this
 859          * by deferring the crypto_tx_tailroom_needed_cnt decrementing on
 860          * key removal for a while, so if we roam the value is larger than
 861          * zero and no 0->1 transition happens.
 862          *
 863          * The cost is that if the AP switching was from an AP with keys
 864          * to one without, we still allocate tailroom while it would no
 865          * longer be needed. However, in the typical (fast) roaming case
 866          * within an ESS this usually won't happen.
 867          */
 868
 869         mutex_lock(&sdata->local->key_mtx);
 870         decrease_tailroom_need_count(sdata,
 871                                      sdata->crypto_tx_tailroom_pending_dec);
 872         sdata->crypto_tx_tailroom_pending_dec = 0;
 873         mutex_unlock(&sdata->local->key_mtx);
 874 }
 875
 876 void ieee80211_gtk_rekey_notify(struct ieee80211_vif *vif, const u8 *bssid,
 877                                 const u8 *replay_ctr, gfp_t gfp)
 878 {
 879         struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
 880
 881         trace_api_gtk_rekey_notify(sdata, bssid, replay_ctr);
 882
 883         cfg80211_gtk_rekey_notify(sdata->dev, bssid, replay_ctr, gfp);
 884 }
 885 EXPORT_SYMBOL_GPL(ieee80211_gtk_rekey_notify);
 886
 887 void ieee80211_get_key_tx_seq(struct ieee80211_key_conf *keyconf,
 888                               struct ieee80211_key_seq *seq)
 889 {
 890         struct ieee80211_key *key;
 891         u64 pn64;
 892
 893         if (WARN_ON(!(keyconf->flags & IEEE80211_KEY_FLAG_GENERATE_IV)))
 894                 return;
 895
 896         key = container_of(keyconf, struct ieee80211_key, conf);
 897
 898         switch (key->conf.cipher) {
 899         case WLAN_CIPHER_SUITE_TKIP:
 900                 seq->tkip.iv32 = key->u.tkip.tx.iv32;
 901                 seq->tkip.iv16 = key->u.tkip.tx.iv16;
 902                 break;
 903         case WLAN_CIPHER_SUITE_CCMP:
 904         case WLAN_CIPHER_SUITE_CCMP_256:
 905         case WLAN_CIPHER_SUITE_AES_CMAC:
 906         case WLAN_CIPHER_SUITE_BIP_CMAC_256:
 907                 BUILD_BUG_ON(offsetof(typeof(*seq), ccmp) !=
 908                              offsetof(typeof(*seq), aes_cmac));
 909         case WLAN_CIPHER_SUITE_BIP_GMAC_128:
 910         case WLAN_CIPHER_SUITE_BIP_GMAC_256:
 911                 BUILD_BUG_ON(offsetof(typeof(*seq), ccmp) !=
 912                              offsetof(typeof(*seq), aes_gmac));
 913         case WLAN_CIPHER_SUITE_GCMP:
 914         case WLAN_CIPHER_SUITE_GCMP_256:
 915                 BUILD_BUG_ON(offsetof(typeof(*seq), ccmp) !=
 916                              offsetof(typeof(*seq), gcmp));
 917                 pn64 = atomic64_read(&key->conf.tx_pn);
 918                 seq->ccmp.pn[5] = pn64;
 919                 seq->ccmp.pn[4] = pn64 >> 8;
 920                 seq->ccmp.pn[3] = pn64 >> 16;
 921                 seq->ccmp.pn[2] = pn64 >> 24;
 922                 seq->ccmp.pn[1] = pn64 >> 32;
 923                 seq->ccmp.pn[0] = pn64 >> 40;
 924                 break;
 925         default:
 926                 WARN_ON(1);
 927         }
 928 }
 929 EXPORT_SYMBOL(ieee80211_get_key_tx_seq);
 930
 931 void ieee80211_get_key_rx_seq(struct ieee80211_key_conf *keyconf,
 932                               int tid, struct ieee80211_key_seq *seq)
 933 {
 934         struct ieee80211_key *key;
 935         const u8 *pn;
 936
 937         key = container_of(keyconf, struct ieee80211_key, conf);
 938
 939         switch (key->conf.cipher) {
 940         case WLAN_CIPHER_SUITE_TKIP:
 941                 if (WARN_ON(tid < 0 || tid >= IEEE80211_NUM_TIDS))
 942                         return;
 943                 seq->tkip.iv32 = key->u.tkip.rx[tid].iv32;
 944                 seq->tkip.iv16 = key->u.tkip.rx[tid].iv16;
 945                 break;
 946         case WLAN_CIPHER_SUITE_CCMP:
 947         case WLAN_CIPHER_SUITE_CCMP_256:
 948                 if (WARN_ON(tid < -1 || tid >= IEEE80211_NUM_TIDS))
 949                         return;
 950                 if (tid < 0)
 951                         pn = key->u.ccmp.rx_pn[IEEE80211_NUM_TIDS];
 952                 else
 953                         pn = key->u.ccmp.rx_pn[tid];
 954                 memcpy(seq->ccmp.pn, pn, IEEE80211_CCMP_PN_LEN);
 955                 break;
 956         case WLAN_CIPHER_SUITE_AES_CMAC:
 957         case WLAN_CIPHER_SUITE_BIP_CMAC_256:
 958                 if (WARN_ON(tid != 0))
 959                         return;
 960                 pn = key->u.aes_cmac.rx_pn;
 961                 memcpy(seq->aes_cmac.pn, pn, IEEE80211_CMAC_PN_LEN);
 962                 break;
 963         case WLAN_CIPHER_SUITE_BIP_GMAC_128:
 964         case WLAN_CIPHER_SUITE_BIP_GMAC_256:
 965                 if (WARN_ON(tid != 0))
 966                         return;
 967                 pn = key->u.aes_gmac.rx_pn;
 968                 memcpy(seq->aes_gmac.pn, pn, IEEE80211_GMAC_PN_LEN);
 969                 break;
 970         case WLAN_CIPHER_SUITE_GCMP:
 971         case WLAN_CIPHER_SUITE_GCMP_256:
 972                 if (WARN_ON(tid < -1 || tid >= IEEE80211_NUM_TIDS))
 973                         return;
 974                 if (tid < 0)
 975                         pn = key->u.gcmp.rx_pn[IEEE80211_NUM_TIDS];
 976                 else
 977                         pn = key->u.gcmp.rx_pn[tid];
 978                 memcpy(seq->gcmp.pn, pn, IEEE80211_GCMP_PN_LEN);
 979                 break;
 980         }
 981 }
 982 EXPORT_SYMBOL(ieee80211_get_key_rx_seq);
 983
 984 void ieee80211_set_key_tx_seq(struct ieee80211_key_conf *keyconf,
 985                               struct ieee80211_key_seq *seq)
 986 {
 987         struct ieee80211_key *key;
 988         u64 pn64;
 989
 990         key = container_of(keyconf, struct ieee80211_key, conf);
 991
 992         switch (key->conf.cipher) {
 993         case WLAN_CIPHER_SUITE_TKIP:
 994                 key->u.tkip.tx.iv32 = seq->tkip.iv32;
 995                 key->u.tkip.tx.iv16 = seq->tkip.iv16;
 996                 break;
 997         case WLAN_CIPHER_SUITE_CCMP:
 998         case WLAN_CIPHER_SUITE_CCMP_256:
 999         case WLAN_CIPHER_SUITE_AES_CMAC:
1000         case WLAN_CIPHER_SUITE_BIP_CMAC_256:
1001                 BUILD_BUG_ON(offsetof(typeof(*seq), ccmp) !=
1002                              offsetof(typeof(*seq), aes_cmac));
1003         case WLAN_CIPHER_SUITE_BIP_GMAC_128:
1004         case WLAN_CIPHER_SUITE_BIP_GMAC_256:
1005                 BUILD_BUG_ON(offsetof(typeof(*seq), ccmp) !=
1006                              offsetof(typeof(*seq), aes_gmac));
1007         case WLAN_CIPHER_SUITE_GCMP:
1008         case WLAN_CIPHER_SUITE_GCMP_256:
1009                 BUILD_BUG_ON(offsetof(typeof(*seq), ccmp) !=
1010                              offsetof(typeof(*seq), gcmp));
1011                 pn64 = (u64)seq->ccmp.pn[5] |
1012                        ((u64)seq->ccmp.pn[4] << 8) |
1013                        ((u64)seq->ccmp.pn[3] << 16) |
1014                        ((u64)seq->ccmp.pn[2] << 24) |
1015                        ((u64)seq->ccmp.pn[1] << 32) |
1016                        ((u64)seq->ccmp.pn[0] << 40);
1017                 atomic64_set(&key->conf.tx_pn, pn64);
1018                 break;
1019         default:
1020                 WARN_ON(1);
1021                 break;
1022         }
1023 }
1024 EXPORT_SYMBOL_GPL(ieee80211_set_key_tx_seq);
1025
1026 void ieee80211_set_key_rx_seq(struct ieee80211_key_conf *keyconf,
1027                               int tid, struct ieee80211_key_seq *seq)
1028 {
1029         struct ieee80211_key *key;
1030         u8 *pn;
1031
1032         key = container_of(keyconf, struct ieee80211_key, conf);
1033
1034         switch (key->conf.cipher) {
1035         case WLAN_CIPHER_SUITE_TKIP:
1036                 if (WARN_ON(tid < 0 || tid >= IEEE80211_NUM_TIDS))
1037                         return;
1038                 key->u.tkip.rx[tid].iv32 = seq->tkip.iv32;
1039                 key->u.tkip.rx[tid].iv16 = seq->tkip.iv16;
1040                 break;
1041         case WLAN_CIPHER_SUITE_CCMP:
1042         case WLAN_CIPHER_SUITE_CCMP_256:
1043                 if (WARN_ON(tid < -1 || tid >= IEEE80211_NUM_TIDS))
1044                         return;
1045                 if (tid < 0)
1046                         pn = key->u.ccmp.rx_pn[IEEE80211_NUM_TIDS];
1047                 else
1048                         pn = key->u.ccmp.rx_pn[tid];
1049                 memcpy(pn, seq->ccmp.pn, IEEE80211_CCMP_PN_LEN);
1050                 break;
1051         case WLAN_CIPHER_SUITE_AES_CMAC:
1052         case WLAN_CIPHER_SUITE_BIP_CMAC_256:
1053                 if (WARN_ON(tid != 0))
1054                         return;
1055                 pn = key->u.aes_cmac.rx_pn;
1056                 memcpy(pn, seq->aes_cmac.pn, IEEE80211_CMAC_PN_LEN);
1057                 break;
1058         case WLAN_CIPHER_SUITE_BIP_GMAC_128:
1059         case WLAN_CIPHER_SUITE_BIP_GMAC_256:
1060                 if (WARN_ON(tid != 0))
1061                         return;
1062                 pn = key->u.aes_gmac.rx_pn;
1063                 memcpy(pn, seq->aes_gmac.pn, IEEE80211_GMAC_PN_LEN);
1064                 break;
1065         case WLAN_CIPHER_SUITE_GCMP:
1066         case WLAN_CIPHER_SUITE_GCMP_256:
1067                 if (WARN_ON(tid < -1 || tid >= IEEE80211_NUM_TIDS))
1068                         return;
1069                 if (tid < 0)
1070                         pn = key->u.gcmp.rx_pn[IEEE80211_NUM_TIDS];
1071                 else
1072                         pn = key->u.gcmp.rx_pn[tid];
1073                 memcpy(pn, seq->gcmp.pn, IEEE80211_GCMP_PN_LEN);
1074                 break;
1075         default:
1076                 WARN_ON(1);
1077                 break;
1078         }
1079 }
1080 EXPORT_SYMBOL_GPL(ieee80211_set_key_rx_seq);
1081
1082 void ieee80211_remove_key(struct ieee80211_key_conf *keyconf)
1083 {
1084         struct ieee80211_key *key;
1085
1086         key = container_of(keyconf, struct ieee80211_key, conf);
1087
1088         assert_key_lock(key->local);
1089
1090         /*
1091          * if key was uploaded, we assume the driver will/has remove(d)
1092          * it, so adjust bookkeeping accordingly
1093          */
1094         if (key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE) {
1095                 key->flags &= ~KEY_FLAG_UPLOADED_TO_HARDWARE;
1096
1097                 if (!((key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_MMIC) ||
1098                       (key->conf.flags & IEEE80211_KEY_FLAG_RESERVE_TAILROOM)))
1099                         increment_tailroom_need_count(key->sdata);
1100         }
1101
1102         ieee80211_key_free(key, false);
1103 }
1104 EXPORT_SYMBOL_GPL(ieee80211_remove_key);
1105
1106 struct ieee80211_key_conf *
1107 ieee80211_gtk_rekey_add(struct ieee80211_vif *vif,
1108                         struct ieee80211_key_conf *keyconf)
1109 {
1110         struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
1111         struct ieee80211_local *local = sdata->local;
1112         struct ieee80211_key *key;
1113         int err;
1114
1115         if (WARN_ON(!local->wowlan))
1116                 return ERR_PTR(-EINVAL);
1117
1118         if (WARN_ON(vif->type != NL80211_IFTYPE_STATION))
1119                 return ERR_PTR(-EINVAL);
1120
1121         key = ieee80211_key_alloc(keyconf->cipher, keyconf->keyidx,
1122                                   keyconf->keylen, keyconf->key,
1123                                   0, NULL, NULL);
1124         if (IS_ERR(key))
1125                 return ERR_CAST(key);
1126
1127         if (sdata->u.mgd.mfp != IEEE80211_MFP_DISABLED)
1128                 key->conf.flags |= IEEE80211_KEY_FLAG_RX_MGMT;
1129
1130         err = ieee80211_key_link(key, sdata, NULL);
1131         if (err)
1132                 return ERR_PTR(err);
1133
1134         return &key->conf;
1135 }
1136 EXPORT_SYMBOL_GPL(ieee80211_gtk_rekey_add);