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                 if (sdata->vif.type != NL80211_IFTYPE_AP_VLAN)
 269                         drv_set_default_unicast_key(sdata->local, sdata, idx);
 270         }
 271
 272         if (multi)
 273                 rcu_assign_pointer(sdata->default_multicast_key, key);
 274
 275         ieee80211_debugfs_key_update_default(sdata);
 276 }
 277
 278 void ieee80211_set_default_key(struct ieee80211_sub_if_data *sdata, int idx,
 279                                bool uni, bool multi)
 280 {
 281         mutex_lock(&sdata->local->key_mtx);
 282         __ieee80211_set_default_key(sdata, idx, uni, multi);
 283         mutex_unlock(&sdata->local->key_mtx);
 284 }
 285
 286 static void
 287 __ieee80211_set_default_mgmt_key(struct ieee80211_sub_if_data *sdata, int idx)
 288 {
 289         struct ieee80211_key *key = NULL;
 290
 291         assert_key_lock(sdata->local);
 292
 293         if (idx >= NUM_DEFAULT_KEYS &&
 294             idx < NUM_DEFAULT_KEYS + NUM_DEFAULT_MGMT_KEYS)
 295                 key = key_mtx_dereference(sdata->local, sdata->keys[idx]);
 296
 297         rcu_assign_pointer(sdata->default_mgmt_key, key);
 298
 299         ieee80211_debugfs_key_update_default(sdata);
 300 }
 301
 302 void ieee80211_set_default_mgmt_key(struct ieee80211_sub_if_data *sdata,
 303                                     int idx)
 304 {
 305         mutex_lock(&sdata->local->key_mtx);
 306         __ieee80211_set_default_mgmt_key(sdata, idx);
 307         mutex_unlock(&sdata->local->key_mtx);
 308 }
 309
 310
 311 static void ieee80211_key_replace(struct ieee80211_sub_if_data *sdata,
 312                                   struct sta_info *sta,
 313                                   bool pairwise,
 314                                   struct ieee80211_key *old,
 315                                   struct ieee80211_key *new)
 316 {
 317         int idx;
 318         bool defunikey, defmultikey, defmgmtkey;
 319
 320         /* caller must provide at least one old/new */
 321         if (WARN_ON(!new && !old))
 322                 return;
 323
 324         if (new)
 325                 list_add_tail_rcu(&new->list, &sdata->key_list);
 326
 327         WARN_ON(new && old && new->conf.keyidx != old->conf.keyidx);
 328
 329         if (old)
 330                 idx = old->conf.keyidx;
 331         else
 332                 idx = new->conf.keyidx;
 333
 334         if (sta) {
 335                 if (pairwise) {
 336                         rcu_assign_pointer(sta->ptk[idx], new);
 337                         sta->ptk_idx = idx;
 338                         ieee80211_check_fast_xmit(sta);
 339                 } else {
 340                         rcu_assign_pointer(sta->gtk[idx], new);
 341                 }
 342                 ieee80211_check_fast_rx(sta);
 343         } else {
 344                 defunikey = old &&
 345                         old == key_mtx_dereference(sdata->local,
 346                                                 sdata->default_unicast_key);
 347                 defmultikey = old &&
 348                         old == key_mtx_dereference(sdata->local,
 349                                                 sdata->default_multicast_key);
 350                 defmgmtkey = old &&
 351                         old == key_mtx_dereference(sdata->local,
 352                                                 sdata->default_mgmt_key);
 353
 354                 if (defunikey && !new)
 355                         __ieee80211_set_default_key(sdata, -1, true, false);
 356                 if (defmultikey && !new)
 357                         __ieee80211_set_default_key(sdata, -1, false, true);
 358                 if (defmgmtkey && !new)
 359                         __ieee80211_set_default_mgmt_key(sdata, -1);
 360
 361                 rcu_assign_pointer(sdata->keys[idx], new);
 362                 if (defunikey && new)
 363                         __ieee80211_set_default_key(sdata, new->conf.keyidx,
 364                                                     true, false);
 365                 if (defmultikey && new)
 366                         __ieee80211_set_default_key(sdata, new->conf.keyidx,
 367                                                     false, true);
 368                 if (defmgmtkey && new)
 369                         __ieee80211_set_default_mgmt_key(sdata,
 370                                                          new->conf.keyidx);
 371         }
 372
 373         if (old)
 374                 list_del_rcu(&old->list);
 375 }
 376
 377 struct ieee80211_key *
 378 ieee80211_key_alloc(u32 cipher, int idx, size_t key_len,
 379                     const u8 *key_data,
 380                     size_t seq_len, const u8 *seq,
 381                     const struct ieee80211_cipher_scheme *cs)
 382 {
 383         struct ieee80211_key *key;
 384         int i, j, err;
 385
 386         if (WARN_ON(idx < 0 || idx >= NUM_DEFAULT_KEYS + NUM_DEFAULT_MGMT_KEYS))
 387                 return ERR_PTR(-EINVAL);
 388
 389         key = kzalloc(sizeof(struct ieee80211_key) + key_len, GFP_KERNEL);
 390         if (!key)
 391                 return ERR_PTR(-ENOMEM);
 392
 393         /*
 394          * Default to software encryption; we'll later upload the
 395          * key to the hardware if possible.
 396          */
 397         key->conf.flags = 0;
 398         key->flags = 0;
 399
 400         key->conf.cipher = cipher;
 401         key->conf.keyidx = idx;
 402         key->conf.keylen = key_len;
 403         switch (cipher) {
 404         case WLAN_CIPHER_SUITE_WEP40:
 405         case WLAN_CIPHER_SUITE_WEP104:
 406                 key->conf.iv_len = IEEE80211_WEP_IV_LEN;
 407                 key->conf.icv_len = IEEE80211_WEP_ICV_LEN;
 408                 break;
 409         case WLAN_CIPHER_SUITE_TKIP:
 410                 key->conf.iv_len = IEEE80211_TKIP_IV_LEN;
 411                 key->conf.icv_len = IEEE80211_TKIP_ICV_LEN;
 412                 if (seq) {
 413                         for (i = 0; i < IEEE80211_NUM_TIDS; i++) {
 414                                 key->u.tkip.rx[i].iv32 =
 415                                         get_unaligned_le32(&seq[2]);
 416                                 key->u.tkip.rx[i].iv16 =
 417                                         get_unaligned_le16(seq);
 418                         }
 419                 }
 420                 spin_lock_init(&key->u.tkip.txlock);
 421                 break;
 422         case WLAN_CIPHER_SUITE_CCMP:
 423                 key->conf.iv_len = IEEE80211_CCMP_HDR_LEN;
 424                 key->conf.icv_len = IEEE80211_CCMP_MIC_LEN;
 425                 if (seq) {
 426                         for (i = 0; i < IEEE80211_NUM_TIDS + 1; i++)
 427                                 for (j = 0; j < IEEE80211_CCMP_PN_LEN; j++)
 428                                         key->u.ccmp.rx_pn[i][j] =
 429                                                 seq[IEEE80211_CCMP_PN_LEN - j - 1];
 430                 }
 431                 /*
 432                  * Initialize AES key state here as an optimization so that
 433                  * it does not need to be initialized for every packet.
 434                  */
 435                 key->u.ccmp.tfm = ieee80211_aes_key_setup_encrypt(
 436                         key_data, key_len, IEEE80211_CCMP_MIC_LEN);
 437                 if (IS_ERR(key->u.ccmp.tfm)) {
 438                         err = PTR_ERR(key->u.ccmp.tfm);
 439                         kfree(key);
 440                         return ERR_PTR(err);
 441                 }
 442                 break;
 443         case WLAN_CIPHER_SUITE_CCMP_256:
 444                 key->conf.iv_len = IEEE80211_CCMP_256_HDR_LEN;
 445                 key->conf.icv_len = IEEE80211_CCMP_256_MIC_LEN;
 446                 for (i = 0; seq && i < IEEE80211_NUM_TIDS + 1; i++)
 447                         for (j = 0; j < IEEE80211_CCMP_256_PN_LEN; j++)
 448                                 key->u.ccmp.rx_pn[i][j] =
 449                                         seq[IEEE80211_CCMP_256_PN_LEN - j - 1];
 450                 /* Initialize AES key state here as an optimization so that
 451                  * it does not need to be initialized for every packet.
 452                  */
 453                 key->u.ccmp.tfm = ieee80211_aes_key_setup_encrypt(
 454                         key_data, key_len, IEEE80211_CCMP_256_MIC_LEN);
 455                 if (IS_ERR(key->u.ccmp.tfm)) {
 456                         err = PTR_ERR(key->u.ccmp.tfm);
 457                         kfree(key);
 458                         return ERR_PTR(err);
 459                 }
 460                 break;
 461         case WLAN_CIPHER_SUITE_AES_CMAC:
 462         case WLAN_CIPHER_SUITE_BIP_CMAC_256:
 463                 key->conf.iv_len = 0;
 464                 if (cipher == WLAN_CIPHER_SUITE_AES_CMAC)
 465                         key->conf.icv_len = sizeof(struct ieee80211_mmie);
 466                 else
 467                         key->conf.icv_len = sizeof(struct ieee80211_mmie_16);
 468                 if (seq)
 469                         for (j = 0; j < IEEE80211_CMAC_PN_LEN; j++)
 470                                 key->u.aes_cmac.rx_pn[j] =
 471                                         seq[IEEE80211_CMAC_PN_LEN - j - 1];
 472                 /*
 473                  * Initialize AES key state here as an optimization so that
 474                  * it does not need to be initialized for every packet.
 475                  */
 476                 key->u.aes_cmac.tfm =
 477                         ieee80211_aes_cmac_key_setup(key_data, key_len);
 478                 if (IS_ERR(key->u.aes_cmac.tfm)) {
 479                         err = PTR_ERR(key->u.aes_cmac.tfm);
 480                         kfree(key);
 481                         return ERR_PTR(err);
 482                 }
 483                 break;
 484         case WLAN_CIPHER_SUITE_BIP_GMAC_128:
 485         case WLAN_CIPHER_SUITE_BIP_GMAC_256:
 486                 key->conf.iv_len = 0;
 487                 key->conf.icv_len = sizeof(struct ieee80211_mmie_16);
 488                 if (seq)
 489                         for (j = 0; j < IEEE80211_GMAC_PN_LEN; j++)
 490                                 key->u.aes_gmac.rx_pn[j] =
 491                                         seq[IEEE80211_GMAC_PN_LEN - j - 1];
 492                 /* Initialize AES key state here as an optimization so that
 493                  * it does not need to be initialized for every packet.
 494                  */
 495                 key->u.aes_gmac.tfm =
 496                         ieee80211_aes_gmac_key_setup(key_data, key_len);
 497                 if (IS_ERR(key->u.aes_gmac.tfm)) {
 498                         err = PTR_ERR(key->u.aes_gmac.tfm);
 499                         kfree(key);
 500                         return ERR_PTR(err);
 501                 }
 502                 break;
 503         case WLAN_CIPHER_SUITE_GCMP:
 504         case WLAN_CIPHER_SUITE_GCMP_256:
 505                 key->conf.iv_len = IEEE80211_GCMP_HDR_LEN;
 506                 key->conf.icv_len = IEEE80211_GCMP_MIC_LEN;
 507                 for (i = 0; seq && i < IEEE80211_NUM_TIDS + 1; i++)
 508                         for (j = 0; j < IEEE80211_GCMP_PN_LEN; j++)
 509                                 key->u.gcmp.rx_pn[i][j] =
 510                                         seq[IEEE80211_GCMP_PN_LEN - j - 1];
 511                 /* Initialize AES key state here as an optimization so that
 512                  * it does not need to be initialized for every packet.
 513                  */
 514                 key->u.gcmp.tfm = ieee80211_aes_gcm_key_setup_encrypt(key_data,
 515                                                                       key_len);
 516                 if (IS_ERR(key->u.gcmp.tfm)) {
 517                         err = PTR_ERR(key->u.gcmp.tfm);
 518                         kfree(key);
 519                         return ERR_PTR(err);
 520                 }
 521                 break;
 522         default:
 523                 if (cs) {
 524                         if (seq_len && seq_len != cs->pn_len) {
 525                                 kfree(key);
 526                                 return ERR_PTR(-EINVAL);
 527                         }
 528
 529                         key->conf.iv_len = cs->hdr_len;
 530                         key->conf.icv_len = cs->mic_len;
 531                         for (i = 0; i < IEEE80211_NUM_TIDS + 1; i++)
 532                                 for (j = 0; j < seq_len; j++)
 533                                         key->u.gen.rx_pn[i][j] =
 534                                                         seq[seq_len - j - 1];
 535                         key->flags |= KEY_FLAG_CIPHER_SCHEME;
 536                 }
 537         }
 538         memcpy(key->conf.key, key_data, key_len);
 539         INIT_LIST_HEAD(&key->list);
 540
 541         return key;
 542 }
 543
 544 static void ieee80211_key_free_common(struct ieee80211_key *key)
 545 {
 546         switch (key->conf.cipher) {
 547         case WLAN_CIPHER_SUITE_CCMP:
 548         case WLAN_CIPHER_SUITE_CCMP_256:
 549                 ieee80211_aes_key_free(key->u.ccmp.tfm);
 550                 break;
 551         case WLAN_CIPHER_SUITE_AES_CMAC:
 552         case WLAN_CIPHER_SUITE_BIP_CMAC_256:
 553                 ieee80211_aes_cmac_key_free(key->u.aes_cmac.tfm);
 554                 break;
 555         case WLAN_CIPHER_SUITE_BIP_GMAC_128:
 556         case WLAN_CIPHER_SUITE_BIP_GMAC_256:
 557                 ieee80211_aes_gmac_key_free(key->u.aes_gmac.tfm);
 558                 break;
 559         case WLAN_CIPHER_SUITE_GCMP:
 560         case WLAN_CIPHER_SUITE_GCMP_256:
 561                 ieee80211_aes_gcm_key_free(key->u.gcmp.tfm);
 562                 break;
 563         }
 564         kzfree(key);
 565 }
 566
 567 static void __ieee80211_key_destroy(struct ieee80211_key *key,
 568                                     bool delay_tailroom)
 569 {
 570         if (key->local)
 571                 ieee80211_key_disable_hw_accel(key);
 572
 573         if (key->local) {
 574                 struct ieee80211_sub_if_data *sdata = key->sdata;
 575
 576                 ieee80211_debugfs_key_remove(key);
 577
 578                 if (delay_tailroom) {
 579                         /* see ieee80211_delayed_tailroom_dec */
 580                         sdata->crypto_tx_tailroom_pending_dec++;
 581                         schedule_delayed_work(&sdata->dec_tailroom_needed_wk,
 582                                               HZ/2);
 583                 } else {
 584                         decrease_tailroom_need_count(sdata, 1);
 585                 }
 586         }
 587
 588         ieee80211_key_free_common(key);
 589 }
 590
 591 static void ieee80211_key_destroy(struct ieee80211_key *key,
 592                                   bool delay_tailroom)
 593 {
 594         if (!key)
 595                 return;
 596
 597         /*
 598          * Synchronize so the TX path and rcu key iterators
 599          * can no longer be using this key before we free/remove it.
 600          */
 601         synchronize_net();
 602
 603         __ieee80211_key_destroy(key, delay_tailroom);
 604 }
 605
 606 void ieee80211_key_free_unused(struct ieee80211_key *key)
 607 {
 608         WARN_ON(key->sdata || key->local);
 609         ieee80211_key_free_common(key);
 610 }
 611
 612 int ieee80211_key_link(struct ieee80211_key *key,
 613                        struct ieee80211_sub_if_data *sdata,
 614                        struct sta_info *sta)
 615 {
 616         struct ieee80211_local *local = sdata->local;
 617         struct ieee80211_key *old_key;
 618         int idx, ret;
 619         bool pairwise;
 620
 621         pairwise = key->conf.flags & IEEE80211_KEY_FLAG_PAIRWISE;
 622         idx = key->conf.keyidx;
 623         key->local = sdata->local;
 624         key->sdata = sdata;
 625         key->sta = sta;
 626
 627         mutex_lock(&sdata->local->key_mtx);
 628
 629         if (sta && pairwise)
 630                 old_key = key_mtx_dereference(sdata->local, sta->ptk[idx]);
 631         else if (sta)
 632                 old_key = key_mtx_dereference(sdata->local, sta->gtk[idx]);
 633         else
 634                 old_key = key_mtx_dereference(sdata->local, sdata->keys[idx]);
 635
 636         increment_tailroom_need_count(sdata);
 637
 638         ieee80211_key_replace(sdata, sta, pairwise, old_key, key);
 639         ieee80211_key_destroy(old_key, true);
 640
 641         ieee80211_debugfs_key_add(key);
 642
 643         if (!local->wowlan) {
 644                 ret = ieee80211_key_enable_hw_accel(key);
 645                 if (ret)
 646                         ieee80211_key_free(key, true);
 647         } else {
 648                 ret = 0;
 649         }
 650
 651         mutex_unlock(&sdata->local->key_mtx);
 652
 653         return ret;
 654 }
 655
 656 void ieee80211_key_free(struct ieee80211_key *key, bool delay_tailroom)
 657 {
 658         if (!key)
 659                 return;
 660
 661         /*
 662          * Replace key with nothingness if it was ever used.
 663          */
 664         if (key->sdata)
 665                 ieee80211_key_replace(key->sdata, key->sta,
 666                                 key->conf.flags & IEEE80211_KEY_FLAG_PAIRWISE,
 667                                 key, NULL);
 668         ieee80211_key_destroy(key, delay_tailroom);
 669 }
 670
 671 void ieee80211_enable_keys(struct ieee80211_sub_if_data *sdata)
 672 {
 673         struct ieee80211_key *key;
 674         struct ieee80211_sub_if_data *vlan;
 675
 676         ASSERT_RTNL();
 677
 678         if (WARN_ON(!ieee80211_sdata_running(sdata)))
 679                 return;
 680
 681         mutex_lock(&sdata->local->key_mtx);
 682
 683         WARN_ON_ONCE(sdata->crypto_tx_tailroom_needed_cnt ||
 684                      sdata->crypto_tx_tailroom_pending_dec);
 685
 686         if (sdata->vif.type == NL80211_IFTYPE_AP) {
 687                 list_for_each_entry(vlan, &sdata->u.ap.vlans, u.vlan.list)
 688                         WARN_ON_ONCE(vlan->crypto_tx_tailroom_needed_cnt ||
 689                                      vlan->crypto_tx_tailroom_pending_dec);
 690         }
 691
 692         list_for_each_entry(key, &sdata->key_list, list) {
 693                 increment_tailroom_need_count(sdata);
 694                 ieee80211_key_enable_hw_accel(key);
 695         }
 696
 697         mutex_unlock(&sdata->local->key_mtx);
 698 }
 699
 700 void ieee80211_reset_crypto_tx_tailroom(struct ieee80211_sub_if_data *sdata)
 701 {
 702         struct ieee80211_sub_if_data *vlan;
 703
 704         mutex_lock(&sdata->local->key_mtx);
 705
 706         sdata->crypto_tx_tailroom_needed_cnt = 0;
 707
 708         if (sdata->vif.type == NL80211_IFTYPE_AP) {
 709                 list_for_each_entry(vlan, &sdata->u.ap.vlans, u.vlan.list)
 710                         vlan->crypto_tx_tailroom_needed_cnt = 0;
 711         }
 712
 713         mutex_unlock(&sdata->local->key_mtx);
 714 }
 715
 716 void ieee80211_iter_keys(struct ieee80211_hw *hw,
 717                          struct ieee80211_vif *vif,
 718                          void (*iter)(struct ieee80211_hw *hw,
 719                                       struct ieee80211_vif *vif,
 720                                       struct ieee80211_sta *sta,
 721                                       struct ieee80211_key_conf *key,
 722                                       void *data),
 723                          void *iter_data)
 724 {
 725         struct ieee80211_local *local = hw_to_local(hw);
 726         struct ieee80211_key *key, *tmp;
 727         struct ieee80211_sub_if_data *sdata;
 728
 729         ASSERT_RTNL();
 730
 731         mutex_lock(&local->key_mtx);
 732         if (vif) {
 733                 sdata = vif_to_sdata(vif);
 734                 list_for_each_entry_safe(key, tmp, &sdata->key_list, list)
 735                         iter(hw, &sdata->vif,
 736                              key->sta ? &key->sta->sta : NULL,
 737                              &key->conf, iter_data);
 738         } else {
 739                 list_for_each_entry(sdata, &local->interfaces, list)
 740                         list_for_each_entry_safe(key, tmp,
 741                                                  &sdata->key_list, list)
 742                                 iter(hw, &sdata->vif,
 743                                      key->sta ? &key->sta->sta : NULL,
 744                                      &key->conf, iter_data);
 745         }
 746         mutex_unlock(&local->key_mtx);
 747 }
 748 EXPORT_SYMBOL(ieee80211_iter_keys);
 749
 750 static void
 751 _ieee80211_iter_keys_rcu(struct ieee80211_hw *hw,
 752                          struct ieee80211_sub_if_data *sdata,
 753                          void (*iter)(struct ieee80211_hw *hw,
 754                                       struct ieee80211_vif *vif,
 755                                       struct ieee80211_sta *sta,
 756                                       struct ieee80211_key_conf *key,
 757                                       void *data),
 758                          void *iter_data)
 759 {
 760         struct ieee80211_key *key;
 761
 762         list_for_each_entry_rcu(key, &sdata->key_list, list) {
 763                 /* skip keys of station in removal process */
 764                 if (key->sta && key->sta->removed)
 765                         continue;
 766                 if (!(key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE))
 767                         continue;
 768
 769                 iter(hw, &sdata->vif,
 770                      key->sta ? &key->sta->sta : NULL,
 771                      &key->conf, iter_data);
 772         }
 773 }
 774
 775 void ieee80211_iter_keys_rcu(struct ieee80211_hw *hw,
 776                              struct ieee80211_vif *vif,
 777                              void (*iter)(struct ieee80211_hw *hw,
 778                                           struct ieee80211_vif *vif,
 779                                           struct ieee80211_sta *sta,
 780                                           struct ieee80211_key_conf *key,
 781                                           void *data),
 782                              void *iter_data)
 783 {
 784         struct ieee80211_local *local = hw_to_local(hw);
 785         struct ieee80211_sub_if_data *sdata;
 786
 787         if (vif) {
 788                 sdata = vif_to_sdata(vif);
 789                 _ieee80211_iter_keys_rcu(hw, sdata, iter, iter_data);
 790         } else {
 791                 list_for_each_entry_rcu(sdata, &local->interfaces, list)
 792                         _ieee80211_iter_keys_rcu(hw, sdata, iter, iter_data);
 793         }
 794 }
 795 EXPORT_SYMBOL(ieee80211_iter_keys_rcu);
 796
 797 static void ieee80211_free_keys_iface(struct ieee80211_sub_if_data *sdata,
 798                                       struct list_head *keys)
 799 {
 800         struct ieee80211_key *key, *tmp;
 801
 802         decrease_tailroom_need_count(sdata,
 803                                      sdata->crypto_tx_tailroom_pending_dec);
 804         sdata->crypto_tx_tailroom_pending_dec = 0;
 805
 806         ieee80211_debugfs_key_remove_mgmt_default(sdata);
 807
 808         list_for_each_entry_safe(key, tmp, &sdata->key_list, list) {
 809                 ieee80211_key_replace(key->sdata, key->sta,
 810                                 key->conf.flags & IEEE80211_KEY_FLAG_PAIRWISE,
 811                                 key, NULL);
 812                 list_add_tail(&key->list, keys);
 813         }
 814
 815         ieee80211_debugfs_key_update_default(sdata);
 816 }
 817
 818 void ieee80211_free_keys(struct ieee80211_sub_if_data *sdata,
 819                          bool force_synchronize)
 820 {
 821         struct ieee80211_local *local = sdata->local;
 822         struct ieee80211_sub_if_data *vlan;
 823         struct ieee80211_sub_if_data *master;
 824         struct ieee80211_key *key, *tmp;
 825         LIST_HEAD(keys);
 826
 827         cancel_delayed_work_sync(&sdata->dec_tailroom_needed_wk);
 828
 829         mutex_lock(&local->key_mtx);
 830
 831         ieee80211_free_keys_iface(sdata, &keys);
 832
 833         if (sdata->vif.type == NL80211_IFTYPE_AP) {
 834                 list_for_each_entry(vlan, &sdata->u.ap.vlans, u.vlan.list)
 835                         ieee80211_free_keys_iface(vlan, &keys);
 836         }
 837
 838         if (!list_empty(&keys) || force_synchronize)
 839                 synchronize_net();
 840         list_for_each_entry_safe(key, tmp, &keys, list)
 841                 __ieee80211_key_destroy(key, false);
 842
 843         if (sdata->vif.type == NL80211_IFTYPE_AP_VLAN) {
 844                 if (sdata->bss) {
 845                         master = container_of(sdata->bss,
 846                                               struct ieee80211_sub_if_data,
 847                                               u.ap);
 848
 849                         WARN_ON_ONCE(sdata->crypto_tx_tailroom_needed_cnt !=
 850                                      master->crypto_tx_tailroom_needed_cnt);
 851                 }
 852         } else {
 853                 WARN_ON_ONCE(sdata->crypto_tx_tailroom_needed_cnt ||
 854                              sdata->crypto_tx_tailroom_pending_dec);
 855         }
 856
 857         if (sdata->vif.type == NL80211_IFTYPE_AP) {
 858                 list_for_each_entry(vlan, &sdata->u.ap.vlans, u.vlan.list)
 859                         WARN_ON_ONCE(vlan->crypto_tx_tailroom_needed_cnt ||
 860                                      vlan->crypto_tx_tailroom_pending_dec);
 861         }
 862
 863         mutex_unlock(&local->key_mtx);
 864 }
 865
 866 void ieee80211_free_sta_keys(struct ieee80211_local *local,
 867                              struct sta_info *sta)
 868 {
 869         struct ieee80211_key *key;
 870         int i;
 871
 872         mutex_lock(&local->key_mtx);
 873         for (i = 0; i < ARRAY_SIZE(sta->gtk); i++) {
 874                 key = key_mtx_dereference(local, sta->gtk[i]);
 875                 if (!key)
 876                         continue;
 877                 ieee80211_key_replace(key->sdata, key->sta,
 878                                 key->conf.flags & IEEE80211_KEY_FLAG_PAIRWISE,
 879                                 key, NULL);
 880                 __ieee80211_key_destroy(key, true);
 881         }
 882
 883         for (i = 0; i < NUM_DEFAULT_KEYS; i++) {
 884                 key = key_mtx_dereference(local, sta->ptk[i]);
 885                 if (!key)
 886                         continue;
 887                 ieee80211_key_replace(key->sdata, key->sta,
 888                                 key->conf.flags & IEEE80211_KEY_FLAG_PAIRWISE,
 889                                 key, NULL);
 890                 __ieee80211_key_destroy(key, true);
 891         }
 892
 893         mutex_unlock(&local->key_mtx);
 894 }
 895
 896 void ieee80211_delayed_tailroom_dec(struct work_struct *wk)
 897 {
 898         struct ieee80211_sub_if_data *sdata;
 899
 900         sdata = container_of(wk, struct ieee80211_sub_if_data,
 901                              dec_tailroom_needed_wk.work);
 902
 903         /*
 904          * The reason for the delayed tailroom needed decrementing is to
 905          * make roaming faster: during roaming, all keys are first deleted
 906          * and then new keys are installed. The first new key causes the
 907          * crypto_tx_tailroom_needed_cnt to go from 0 to 1, which invokes
 908          * the cost of synchronize_net() (which can be slow). Avoid this
 909          * by deferring the crypto_tx_tailroom_needed_cnt decrementing on
 910          * key removal for a while, so if we roam the value is larger than
 911          * zero and no 0->1 transition happens.
 912          *
 913          * The cost is that if the AP switching was from an AP with keys
 914          * to one without, we still allocate tailroom while it would no
 915          * longer be needed. However, in the typical (fast) roaming case
 916          * within an ESS this usually won't happen.
 917          */
 918
 919         mutex_lock(&sdata->local->key_mtx);
 920         decrease_tailroom_need_count(sdata,
 921                                      sdata->crypto_tx_tailroom_pending_dec);
 922         sdata->crypto_tx_tailroom_pending_dec = 0;
 923         mutex_unlock(&sdata->local->key_mtx);
 924 }
 925
 926 void ieee80211_gtk_rekey_notify(struct ieee80211_vif *vif, const u8 *bssid,
 927                                 const u8 *replay_ctr, gfp_t gfp)
 928 {
 929         struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
 930
 931         trace_api_gtk_rekey_notify(sdata, bssid, replay_ctr);
 932
 933         cfg80211_gtk_rekey_notify(sdata->dev, bssid, replay_ctr, gfp);
 934 }
 935 EXPORT_SYMBOL_GPL(ieee80211_gtk_rekey_notify);
 936
 937 void ieee80211_get_key_rx_seq(struct ieee80211_key_conf *keyconf,
 938                               int tid, struct ieee80211_key_seq *seq)
 939 {
 940         struct ieee80211_key *key;
 941         const u8 *pn;
 942
 943         key = container_of(keyconf, struct ieee80211_key, conf);
 944
 945         switch (key->conf.cipher) {
 946         case WLAN_CIPHER_SUITE_TKIP:
 947                 if (WARN_ON(tid < 0 || tid >= IEEE80211_NUM_TIDS))
 948                         return;
 949                 seq->tkip.iv32 = key->u.tkip.rx[tid].iv32;
 950                 seq->tkip.iv16 = key->u.tkip.rx[tid].iv16;
 951                 break;
 952         case WLAN_CIPHER_SUITE_CCMP:
 953         case WLAN_CIPHER_SUITE_CCMP_256:
 954                 if (WARN_ON(tid < -1 || tid >= IEEE80211_NUM_TIDS))
 955                         return;
 956                 if (tid < 0)
 957                         pn = key->u.ccmp.rx_pn[IEEE80211_NUM_TIDS];
 958                 else
 959                         pn = key->u.ccmp.rx_pn[tid];
 960                 memcpy(seq->ccmp.pn, pn, IEEE80211_CCMP_PN_LEN);
 961                 break;
 962         case WLAN_CIPHER_SUITE_AES_CMAC:
 963         case WLAN_CIPHER_SUITE_BIP_CMAC_256:
 964                 if (WARN_ON(tid != 0))
 965                         return;
 966                 pn = key->u.aes_cmac.rx_pn;
 967                 memcpy(seq->aes_cmac.pn, pn, IEEE80211_CMAC_PN_LEN);
 968                 break;
 969         case WLAN_CIPHER_SUITE_BIP_GMAC_128:
 970         case WLAN_CIPHER_SUITE_BIP_GMAC_256:
 971                 if (WARN_ON(tid != 0))
 972                         return;
 973                 pn = key->u.aes_gmac.rx_pn;
 974                 memcpy(seq->aes_gmac.pn, pn, IEEE80211_GMAC_PN_LEN);
 975                 break;
 976         case WLAN_CIPHER_SUITE_GCMP:
 977         case WLAN_CIPHER_SUITE_GCMP_256:
 978                 if (WARN_ON(tid < -1 || tid >= IEEE80211_NUM_TIDS))
 979                         return;
 980                 if (tid < 0)
 981                         pn = key->u.gcmp.rx_pn[IEEE80211_NUM_TIDS];
 982                 else
 983                         pn = key->u.gcmp.rx_pn[tid];
 984                 memcpy(seq->gcmp.pn, pn, IEEE80211_GCMP_PN_LEN);
 985                 break;
 986         }
 987 }
 988 EXPORT_SYMBOL(ieee80211_get_key_rx_seq);
 989
 990 void ieee80211_set_key_rx_seq(struct ieee80211_key_conf *keyconf,
 991                               int tid, struct ieee80211_key_seq *seq)
 992 {
 993         struct ieee80211_key *key;
 994         u8 *pn;
 995
 996         key = container_of(keyconf, struct ieee80211_key, conf);
 997
 998         switch (key->conf.cipher) {
 999         case WLAN_CIPHER_SUITE_TKIP:
1000                 if (WARN_ON(tid < 0 || tid >= IEEE80211_NUM_TIDS))
1001                         return;
1002                 key->u.tkip.rx[tid].iv32 = seq->tkip.iv32;
1003                 key->u.tkip.rx[tid].iv16 = seq->tkip.iv16;
1004                 break;
1005         case WLAN_CIPHER_SUITE_CCMP:
1006         case WLAN_CIPHER_SUITE_CCMP_256:
1007                 if (WARN_ON(tid < -1 || tid >= IEEE80211_NUM_TIDS))
1008                         return;
1009                 if (tid < 0)
1010                         pn = key->u.ccmp.rx_pn[IEEE80211_NUM_TIDS];
1011                 else
1012                         pn = key->u.ccmp.rx_pn[tid];
1013                 memcpy(pn, seq->ccmp.pn, IEEE80211_CCMP_PN_LEN);
1014                 break;
1015         case WLAN_CIPHER_SUITE_AES_CMAC:
1016         case WLAN_CIPHER_SUITE_BIP_CMAC_256:
1017                 if (WARN_ON(tid != 0))
1018                         return;
1019                 pn = key->u.aes_cmac.rx_pn;
1020                 memcpy(pn, seq->aes_cmac.pn, IEEE80211_CMAC_PN_LEN);
1021                 break;
1022         case WLAN_CIPHER_SUITE_BIP_GMAC_128:
1023         case WLAN_CIPHER_SUITE_BIP_GMAC_256:
1024                 if (WARN_ON(tid != 0))
1025                         return;
1026                 pn = key->u.aes_gmac.rx_pn;
1027                 memcpy(pn, seq->aes_gmac.pn, IEEE80211_GMAC_PN_LEN);
1028                 break;
1029         case WLAN_CIPHER_SUITE_GCMP:
1030         case WLAN_CIPHER_SUITE_GCMP_256:
1031                 if (WARN_ON(tid < -1 || tid >= IEEE80211_NUM_TIDS))
1032                         return;
1033                 if (tid < 0)
1034                         pn = key->u.gcmp.rx_pn[IEEE80211_NUM_TIDS];
1035                 else
1036                         pn = key->u.gcmp.rx_pn[tid];
1037                 memcpy(pn, seq->gcmp.pn, IEEE80211_GCMP_PN_LEN);
1038                 break;
1039         default:
1040                 WARN_ON(1);
1041                 break;
1042         }
1043 }
1044 EXPORT_SYMBOL_GPL(ieee80211_set_key_rx_seq);
1045
1046 void ieee80211_remove_key(struct ieee80211_key_conf *keyconf)
1047 {
1048         struct ieee80211_key *key;
1049
1050         key = container_of(keyconf, struct ieee80211_key, conf);
1051
1052         assert_key_lock(key->local);
1053
1054         /*
1055          * if key was uploaded, we assume the driver will/has remove(d)
1056          * it, so adjust bookkeeping accordingly
1057          */
1058         if (key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE) {
1059                 key->flags &= ~KEY_FLAG_UPLOADED_TO_HARDWARE;
1060
1061                 if (!((key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_MMIC) ||
1062                       (key->conf.flags & IEEE80211_KEY_FLAG_RESERVE_TAILROOM)))
1063                         increment_tailroom_need_count(key->sdata);
1064         }
1065
1066         ieee80211_key_free(key, false);
1067 }
1068 EXPORT_SYMBOL_GPL(ieee80211_remove_key);
1069
1070 struct ieee80211_key_conf *
1071 ieee80211_gtk_rekey_add(struct ieee80211_vif *vif,
1072                         struct ieee80211_key_conf *keyconf)
1073 {
1074         struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
1075         struct ieee80211_local *local = sdata->local;
1076         struct ieee80211_key *key;
1077         int err;
1078
1079         if (WARN_ON(!local->wowlan))
1080                 return ERR_PTR(-EINVAL);
1081
1082         if (WARN_ON(vif->type != NL80211_IFTYPE_STATION))
1083                 return ERR_PTR(-EINVAL);
1084
1085         key = ieee80211_key_alloc(keyconf->cipher, keyconf->keyidx,
1086                                   keyconf->keylen, keyconf->key,
1087                                   0, NULL, NULL);
1088         if (IS_ERR(key))
1089                 return ERR_CAST(key);
1090
1091         if (sdata->u.mgd.mfp != IEEE80211_MFP_DISABLED)
1092                 key->conf.flags |= IEEE80211_KEY_FLAG_RX_MGMT;
1093
1094         err = ieee80211_key_link(key, sdata, NULL);
1095         if (err)
1096                 return ERR_PTR(err);
1097
1098         return &key->conf;
1099 }
1100 EXPORT_SYMBOL_GPL(ieee80211_gtk_rekey_add);