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