net/mac80211/key.c

   1 /*
   2  * Copyright 2002-2005, Instant802 Networks, Inc.
   3  * Copyright 2005-2006, Devicescape Software, Inc.
   4  * Copyright 2006-2007  Jiri Benc <jbenc@suse.cz>
   5  * Copyright 2007-2008  Johannes Berg <johannes@sipsolutions.net>
   6  * Copyright 2013-2014  Intel Mobile Communications GmbH
   7  * Copyright 2015-2017  Intel Deutschland GmbH
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License version 2 as
  11  * published by the Free Software Foundation.
  12  */
  13
  14 #include <linux/if_ether.h>
  15 #include <linux/etherdevice.h>
  16 #include <linux/list.h>
  17 #include <linux/rcupdate.h>
  18 #include <linux/rtnetlink.h>
  19 #include <linux/slab.h>
  20 #include <linux/export.h>
  21 #include <net/mac80211.h>
  22 #include <crypto/algapi.h>
  23 #include <asm/unaligned.h>
  24 #include "ieee80211_i.h"
  25 #include "driver-ops.h"
  26 #include "debugfs_key.h"
  27 #include "aes_ccm.h"
  28 #include "aes_cmac.h"
  29 #include "aes_gmac.h"
  30 #include "aes_gcm.h"
  31
  32
  33 /**
  34  * DOC: Key handling basics
  35  *
  36  * Key handling in mac80211 is done based on per-interface (sub_if_data)
  37  * keys and per-station keys. Since each station belongs to an interface,
  38  * each station key also belongs to that interface.
  39  *
  40  * Hardware acceleration is done on a best-effort basis for algorithms
  41  * that are implemented in software,  for each key the hardware is asked
  42  * to enable that key for offloading but if it cannot do that the key is
  43  * simply kept for software encryption (unless it is for an algorithm
  44  * that isn't implemented in software).
  45  * There is currently no way of knowing whether a key is handled in SW
  46  * or HW except by looking into debugfs.
  47  *
  48  * All key management is internally protected by a mutex. Within all
  49  * other parts of mac80211, key references are, just as STA structure
  50  * references, protected by RCU. Note, however, that some things are
  51  * unprotected, namely the key->sta dereferences within the hardware
  52  * acceleration functions. This means that sta_info_destroy() must
  53  * remove the key which waits for an RCU grace period.
  54  */
  55
  56 static const u8 bcast_addr[ETH_ALEN] = { 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF };
  57
  58 static void assert_key_lock(struct ieee80211_local *local)
  59 {
  60         lockdep_assert_held(&local->key_mtx);
  61 }
  62
  63 static void
  64 update_vlan_tailroom_need_count(struct ieee80211_sub_if_data *sdata, int delta)
  65 {
  66         struct ieee80211_sub_if_data *vlan;
  67
  68         if (sdata->vif.type != NL80211_IFTYPE_AP)
  69                 return;
  70
  71         /* crypto_tx_tailroom_needed_cnt is protected by this */
  72         assert_key_lock(sdata->local);
  73
  74         rcu_read_lock();
  75
  76         list_for_each_entry_rcu(vlan, &sdata->u.ap.vlans, u.vlan.list)
  77                 vlan->crypto_tx_tailroom_needed_cnt += delta;
  78
  79         rcu_read_unlock();
  80 }
  81
  82 static void increment_tailroom_need_count(struct ieee80211_sub_if_data *sdata)
  83 {
  84         /*
  85          * When this count is zero, SKB resizing for allocating tailroom
  86          * for IV or MMIC is skipped. But, this check has created two race
  87          * cases in xmit path while transiting from zero count to one:
  88          *
  89          * 1. SKB resize was skipped because no key was added but just before
  90          * the xmit key is added and SW encryption kicks off.
  91          *
  92          * 2. SKB resize was skipped because all the keys were hw planted but
  93          * just before xmit one of the key is deleted and SW encryption kicks
  94          * off.
  95          *
  96          * In both the above case SW encryption will find not enough space for
  97          * tailroom and exits with WARN_ON. (See WARN_ONs at wpa.c)
  98          *
  99          * Solution has been explained at
 100          * http://mid.gmane.org/1308590980.4322.19.camel@jlt3.sipsolutions.net
 101          */
 102
 103         assert_key_lock(sdata->local);
 104
 105         update_vlan_tailroom_need_count(sdata, 1);
 106
 107         if (!sdata->crypto_tx_tailroom_needed_cnt++) {
 108                 /*
 109                  * Flush all XMIT packets currently using HW encryption or no
 110                  * encryption at all if the count transition is from 0 -> 1.
 111                  */
 112                 synchronize_net();
 113         }
 114 }
 115
 116 static void decrease_tailroom_need_count(struct ieee80211_sub_if_data *sdata,
 117                                          int delta)
 118 {
 119         assert_key_lock(sdata->local);
 120
 121         WARN_ON_ONCE(sdata->crypto_tx_tailroom_needed_cnt < delta);
 122
 123         update_vlan_tailroom_need_count(sdata, -delta);
 124         sdata->crypto_tx_tailroom_needed_cnt -= delta;
 125 }
 126
 127 static int ieee80211_key_enable_hw_accel(struct ieee80211_key *key)
 128 {
 129         struct ieee80211_sub_if_data *sdata;
 130         struct sta_info *sta;
 131         int ret = -EOPNOTSUPP;
 132
 133         might_sleep();
 134
 135         if (key->flags & KEY_FLAG_TAINTED) {
 136                 /* If we get here, it's during resume and the key is
 137                  * tainted so shouldn't be used/programmed any more.
 138                  * However, its flags may still indicate that it was
 139                  * programmed into the device (since we're in resume)
 140                  * so clear that flag now to avoid trying to remove
 141                  * it again later.
 142                  */
 143                 key->flags &= ~KEY_FLAG_UPLOADED_TO_HARDWARE;
 144                 return -EINVAL;
 145         }
 146
 147         if (!key->local->ops->set_key)
 148                 goto out_unsupported;
 149
 150         assert_key_lock(key->local);
 151
 152         sta = key->sta;
 153
 154         /*
 155          * If this is a per-STA GTK, check if it
 156          * is supported; if not, return.
 157          */
 158         if (sta && !(key->conf.flags & IEEE80211_KEY_FLAG_PAIRWISE) &&
 159             !ieee80211_hw_check(&key->local->hw, SUPPORTS_PER_STA_GTK))
 160                 goto out_unsupported;
 161
 162         if (sta && !sta->uploaded)
 163                 goto out_unsupported;
 164
 165         sdata = key->sdata;
 166         if (sdata->vif.type == NL80211_IFTYPE_AP_VLAN) {
 167                 /*
 168                  * The driver doesn't know anything about VLAN interfaces.
 169                  * Hence, don't send GTKs for VLAN interfaces to the driver.
 170                  */
 171                 if (!(key->conf.flags & IEEE80211_KEY_FLAG_PAIRWISE))
 172                         goto out_unsupported;
 173         }
 174
 175         ret = drv_set_key(key->local, SET_KEY, sdata,
 176                           sta ? &sta->sta : NULL, &key->conf);
 177
 178         if (!ret) {
 179                 key->flags |= KEY_FLAG_UPLOADED_TO_HARDWARE;
 180
 181                 if (!((key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_MMIC) ||
 182                       (key->conf.flags & IEEE80211_KEY_FLAG_RESERVE_TAILROOM)))
 183                         decrease_tailroom_need_count(sdata, 1);
 184
 185                 WARN_ON((key->conf.flags & IEEE80211_KEY_FLAG_PUT_IV_SPACE) &&
 186                         (key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_IV));
 187
 188                 return 0;
 189         }
 190
 191         if (ret != -ENOSPC && ret != -EOPNOTSUPP && ret != 1)
 192                 sdata_err(sdata,
 193                           "failed to set key (%d, %pM) to hardware (%d)\n",
 194                           key->conf.keyidx,
 195                           sta ? sta->sta.addr : bcast_addr, ret);
 196
 197  out_unsupported:
 198         switch (key->conf.cipher) {
 199         case WLAN_CIPHER_SUITE_WEP40:
 200         case WLAN_CIPHER_SUITE_WEP104:
 201         case WLAN_CIPHER_SUITE_TKIP:
 202         case WLAN_CIPHER_SUITE_CCMP:
 203         case WLAN_CIPHER_SUITE_CCMP_256:
 204         case WLAN_CIPHER_SUITE_AES_CMAC:
 205         case WLAN_CIPHER_SUITE_BIP_CMAC_256:
 206         case WLAN_CIPHER_SUITE_BIP_GMAC_128:
 207         case WLAN_CIPHER_SUITE_BIP_GMAC_256:
 208         case WLAN_CIPHER_SUITE_GCMP:
 209         case WLAN_CIPHER_SUITE_GCMP_256:
 210                 /* all of these we can do in software - if driver can */
 211                 if (ret == 1)
 212                         return 0;
 213                 if (ieee80211_hw_check(&key->local->hw, SW_CRYPTO_CONTROL))
 214                         return -EINVAL;
 215                 return 0;
 216         default:
 217                 return -EINVAL;
 218         }
 219 }
 220
 221 static void ieee80211_key_disable_hw_accel(struct ieee80211_key *key)
 222 {
 223         struct ieee80211_sub_if_data *sdata;
 224         struct sta_info *sta;
 225         int ret;
 226
 227         might_sleep();
 228
 229         if (!key || !key->local->ops->set_key)
 230                 return;
 231
 232         assert_key_lock(key->local);
 233
 234         if (!(key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE))
 235                 return;
 236
 237         sta = key->sta;
 238         sdata = key->sdata;
 239
 240         if (!((key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_MMIC) ||
 241               (key->conf.flags & IEEE80211_KEY_FLAG_RESERVE_TAILROOM)))
 242                 increment_tailroom_need_count(sdata);
 243
 244         ret = drv_set_key(key->local, DISABLE_KEY, sdata,
 245                           sta ? &sta->sta : NULL, &key->conf);
 246
 247         if (ret)
 248                 sdata_err(sdata,
 249                           "failed to remove key (%d, %pM) from hardware (%d)\n",
 250                           key->conf.keyidx,
 251                           sta ? sta->sta.addr : bcast_addr, ret);
 252
 253         key->flags &= ~KEY_FLAG_UPLOADED_TO_HARDWARE;
 254 }
 255
 256 static void __ieee80211_set_default_key(struct ieee80211_sub_if_data *sdata,
 257                                         int idx, bool uni, bool multi)
 258 {
 259         struct ieee80211_key *key = NULL;
 260
 261         assert_key_lock(sdata->local);
 262
 263         if (idx >= 0 && idx < NUM_DEFAULT_KEYS)
 264                 key = key_mtx_dereference(sdata->local, sdata->keys[idx]);
 265
 266         if (uni) {
 267                 rcu_assign_pointer(sdata->default_unicast_key, key);
 268                 ieee80211_check_fast_xmit_iface(sdata);
 269                 if (sdata->vif.type != NL80211_IFTYPE_AP_VLAN)
 270                         drv_set_default_unicast_key(sdata->local, sdata, idx);
 271         }
 272
 273         if (multi)
 274                 rcu_assign_pointer(sdata->default_multicast_key, key);
 275
 276         ieee80211_debugfs_key_update_default(sdata);
 277 }
 278
 279 void ieee80211_set_default_key(struct ieee80211_sub_if_data *sdata, int idx,
 280                                bool uni, bool multi)
 281 {
 282         mutex_lock(&sdata->local->key_mtx);
 283         __ieee80211_set_default_key(sdata, idx, uni, multi);
 284         mutex_unlock(&sdata->local->key_mtx);
 285 }
 286
 287 static void
 288 __ieee80211_set_default_mgmt_key(struct ieee80211_sub_if_data *sdata, int idx)
 289 {
 290         struct ieee80211_key *key = NULL;
 291
 292         assert_key_lock(sdata->local);
 293
 294         if (idx >= NUM_DEFAULT_KEYS &&
 295             idx < NUM_DEFAULT_KEYS + NUM_DEFAULT_MGMT_KEYS)
 296                 key = key_mtx_dereference(sdata->local, sdata->keys[idx]);
 297
 298         rcu_assign_pointer(sdata->default_mgmt_key, key);
 299
 300         ieee80211_debugfs_key_update_default(sdata);
 301 }
 302
 303 void ieee80211_set_default_mgmt_key(struct ieee80211_sub_if_data *sdata,
 304                                     int idx)
 305 {
 306         mutex_lock(&sdata->local->key_mtx);
 307         __ieee80211_set_default_mgmt_key(sdata, idx);
 308         mutex_unlock(&sdata->local->key_mtx);
 309 }
 310
 311
 312 static void ieee80211_key_replace(struct ieee80211_sub_if_data *sdata,
 313                                   struct sta_info *sta,
 314                                   bool pairwise,
 315                                   struct ieee80211_key *old,
 316                                   struct ieee80211_key *new)
 317 {
 318         int idx;
 319         bool defunikey, defmultikey, defmgmtkey;
 320
 321         /* caller must provide at least one old/new */
 322         if (WARN_ON(!new && !old))
 323                 return;
 324
 325         if (new)
 326                 list_add_tail_rcu(&new->list, &sdata->key_list);
 327
 328         WARN_ON(new && old && new->conf.keyidx != old->conf.keyidx);
 329
 330         if (old)
 331                 idx = old->conf.keyidx;
 332         else
 333                 idx = new->conf.keyidx;
 334
 335         if (sta) {
 336                 if (pairwise) {
 337                         rcu_assign_pointer(sta->ptk[idx], new);
 338                         sta->ptk_idx = idx;
 339                         ieee80211_check_fast_xmit(sta);
 340                 } else {
 341                         rcu_assign_pointer(sta->gtk[idx], new);
 342                 }
 343                 ieee80211_check_fast_rx(sta);
 344         } else {
 345                 defunikey = old &&
 346                         old == key_mtx_dereference(sdata->local,
 347                                                 sdata->default_unicast_key);
 348                 defmultikey = old &&
 349                         old == key_mtx_dereference(sdata->local,
 350                                                 sdata->default_multicast_key);
 351                 defmgmtkey = old &&
 352                         old == key_mtx_dereference(sdata->local,
 353                                                 sdata->default_mgmt_key);
 354
 355                 if (defunikey && !new)
 356                         __ieee80211_set_default_key(sdata, -1, true, false);
 357                 if (defmultikey && !new)
 358                         __ieee80211_set_default_key(sdata, -1, false, true);
 359                 if (defmgmtkey && !new)
 360                         __ieee80211_set_default_mgmt_key(sdata, -1);
 361
 362                 rcu_assign_pointer(sdata->keys[idx], new);
 363                 if (defunikey && new)
 364                         __ieee80211_set_default_key(sdata, new->conf.keyidx,
 365                                                     true, false);
 366                 if (defmultikey && new)
 367                         __ieee80211_set_default_key(sdata, new->conf.keyidx,
 368                                                     false, true);
 369                 if (defmgmtkey && new)
 370                         __ieee80211_set_default_mgmt_key(sdata,
 371                                                          new->conf.keyidx);
 372         }
 373
 374         if (old)
 375                 list_del_rcu(&old->list);
 376 }
 377
 378 struct ieee80211_key *
 379 ieee80211_key_alloc(u32 cipher, int idx, size_t key_len,
 380                     const u8 *key_data,
 381                     size_t seq_len, const u8 *seq,
 382                     const struct ieee80211_cipher_scheme *cs)
 383 {
 384         struct ieee80211_key *key;
 385         int i, j, err;
 386
 387         if (WARN_ON(idx < 0 || idx >= NUM_DEFAULT_KEYS + NUM_DEFAULT_MGMT_KEYS))
 388                 return ERR_PTR(-EINVAL);
 389
 390         key = kzalloc(sizeof(struct ieee80211_key) + key_len, GFP_KERNEL);
 391         if (!key)
 392                 return ERR_PTR(-ENOMEM);
 393
 394         /*
 395          * Default to software encryption; we'll later upload the
 396          * key to the hardware if possible.
 397          */
 398         key->conf.flags = 0;
 399         key->flags = 0;
 400
 401         key->conf.cipher = cipher;
 402         key->conf.keyidx = idx;
 403         key->conf.keylen = key_len;
 404         switch (cipher) {
 405         case WLAN_CIPHER_SUITE_WEP40:
 406         case WLAN_CIPHER_SUITE_WEP104:
 407                 key->conf.iv_len = IEEE80211_WEP_IV_LEN;
 408                 key->conf.icv_len = IEEE80211_WEP_ICV_LEN;
 409                 break;
 410         case WLAN_CIPHER_SUITE_TKIP:
 411                 key->conf.iv_len = IEEE80211_TKIP_IV_LEN;
 412                 key->conf.icv_len = IEEE80211_TKIP_ICV_LEN;
 413                 if (seq) {
 414                         for (i = 0; i < IEEE80211_NUM_TIDS; i++) {
 415                                 key->u.tkip.rx[i].iv32 =
 416                                         get_unaligned_le32(&seq[2]);
 417                                 key->u.tkip.rx[i].iv16 =
 418                                         get_unaligned_le16(seq);
 419                         }
 420                 }
 421                 spin_lock_init(&key->u.tkip.txlock);
 422                 break;
 423         case WLAN_CIPHER_SUITE_CCMP:
 424                 key->conf.iv_len = IEEE80211_CCMP_HDR_LEN;
 425                 key->conf.icv_len = IEEE80211_CCMP_MIC_LEN;
 426                 if (seq) {
 427                         for (i = 0; i < IEEE80211_NUM_TIDS + 1; i++)
 428                                 for (j = 0; j < IEEE80211_CCMP_PN_LEN; j++)
 429                                         key->u.ccmp.rx_pn[i][j] =
 430                                                 seq[IEEE80211_CCMP_PN_LEN - j - 1];
 431                 }
 432                 /*
 433                  * Initialize AES key state here as an optimization so that
 434                  * it does not need to be initialized for every packet.
 435                  */
 436                 key->u.ccmp.tfm = ieee80211_aes_key_setup_encrypt(
 437                         key_data, key_len, IEEE80211_CCMP_MIC_LEN);
 438                 if (IS_ERR(key->u.ccmp.tfm)) {
 439                         err = PTR_ERR(key->u.ccmp.tfm);
 440                         kfree(key);
 441                         return ERR_PTR(err);
 442                 }
 443                 break;
 444         case WLAN_CIPHER_SUITE_CCMP_256:
 445                 key->conf.iv_len = IEEE80211_CCMP_256_HDR_LEN;
 446                 key->conf.icv_len = IEEE80211_CCMP_256_MIC_LEN;
 447                 for (i = 0; seq && i < IEEE80211_NUM_TIDS + 1; i++)
 448                         for (j = 0; j < IEEE80211_CCMP_256_PN_LEN; j++)
 449                                 key->u.ccmp.rx_pn[i][j] =
 450                                         seq[IEEE80211_CCMP_256_PN_LEN - j - 1];
 451                 /* Initialize AES key state here as an optimization so that
 452                  * it does not need to be initialized for every packet.
 453                  */
 454                 key->u.ccmp.tfm = ieee80211_aes_key_setup_encrypt(
 455                         key_data, key_len, IEEE80211_CCMP_256_MIC_LEN);
 456                 if (IS_ERR(key->u.ccmp.tfm)) {
 457                         err = PTR_ERR(key->u.ccmp.tfm);
 458                         kfree(key);
 459                         return ERR_PTR(err);
 460                 }
 461                 break;
 462         case WLAN_CIPHER_SUITE_AES_CMAC:
 463         case WLAN_CIPHER_SUITE_BIP_CMAC_256:
 464                 key->conf.iv_len = 0;
 465                 if (cipher == WLAN_CIPHER_SUITE_AES_CMAC)
 466                         key->conf.icv_len = sizeof(struct ieee80211_mmie);
 467                 else
 468                         key->conf.icv_len = sizeof(struct ieee80211_mmie_16);
 469                 if (seq)
 470                         for (j = 0; j < IEEE80211_CMAC_PN_LEN; j++)
 471                                 key->u.aes_cmac.rx_pn[j] =
 472                                         seq[IEEE80211_CMAC_PN_LEN - j - 1];
 473                 /*
 474                  * Initialize AES key state here as an optimization so that
 475                  * it does not need to be initialized for every packet.
 476                  */
 477                 key->u.aes_cmac.tfm =
 478                         ieee80211_aes_cmac_key_setup(key_data, key_len);
 479                 if (IS_ERR(key->u.aes_cmac.tfm)) {
 480                         err = PTR_ERR(key->u.aes_cmac.tfm);
 481                         kfree(key);
 482                         return ERR_PTR(err);
 483                 }
 484                 break;
 485         case WLAN_CIPHER_SUITE_BIP_GMAC_128:
 486         case WLAN_CIPHER_SUITE_BIP_GMAC_256:
 487                 key->conf.iv_len = 0;
 488                 key->conf.icv_len = sizeof(struct ieee80211_mmie_16);
 489                 if (seq)
 490                         for (j = 0; j < IEEE80211_GMAC_PN_LEN; j++)
 491                                 key->u.aes_gmac.rx_pn[j] =
 492                                         seq[IEEE80211_GMAC_PN_LEN - j - 1];
 493                 /* Initialize AES key state here as an optimization so that
 494                  * it does not need to be initialized for every packet.
 495                  */
 496                 key->u.aes_gmac.tfm =
 497                         ieee80211_aes_gmac_key_setup(key_data, key_len);
 498                 if (IS_ERR(key->u.aes_gmac.tfm)) {
 499                         err = PTR_ERR(key->u.aes_gmac.tfm);
 500                         kfree(key);
 501                         return ERR_PTR(err);
 502                 }
 503                 break;
 504         case WLAN_CIPHER_SUITE_GCMP:
 505         case WLAN_CIPHER_SUITE_GCMP_256:
 506                 key->conf.iv_len = IEEE80211_GCMP_HDR_LEN;
 507                 key->conf.icv_len = IEEE80211_GCMP_MIC_LEN;
 508                 for (i = 0; seq && i < IEEE80211_NUM_TIDS + 1; i++)
 509                         for (j = 0; j < IEEE80211_GCMP_PN_LEN; j++)
 510                                 key->u.gcmp.rx_pn[i][j] =
 511                                         seq[IEEE80211_GCMP_PN_LEN - j - 1];
 512                 /* Initialize AES key state here as an optimization so that
 513                  * it does not need to be initialized for every packet.
 514                  */
 515                 key->u.gcmp.tfm = ieee80211_aes_gcm_key_setup_encrypt(key_data,
 516                                                                       key_len);
 517                 if (IS_ERR(key->u.gcmp.tfm)) {
 518                         err = PTR_ERR(key->u.gcmp.tfm);
 519                         kfree(key);
 520                         return ERR_PTR(err);
 521                 }
 522                 break;
 523         default:
 524                 if (cs) {
 525                         if (seq_len && seq_len != cs->pn_len) {
 526                                 kfree(key);
 527                                 return ERR_PTR(-EINVAL);
 528                         }
 529
 530                         key->conf.iv_len = cs->hdr_len;
 531                         key->conf.icv_len = cs->mic_len;
 532                         for (i = 0; i < IEEE80211_NUM_TIDS + 1; i++)
 533                                 for (j = 0; j < seq_len; j++)
 534                                         key->u.gen.rx_pn[i][j] =
 535                                                         seq[seq_len - j - 1];
 536                         key->flags |= KEY_FLAG_CIPHER_SCHEME;
 537                 }
 538         }
 539         memcpy(key->conf.key, key_data, key_len);
 540         INIT_LIST_HEAD(&key->list);
 541
 542         return key;
 543 }
 544
 545 static void ieee80211_key_free_common(struct ieee80211_key *key)
 546 {
 547         switch (key->conf.cipher) {
 548         case WLAN_CIPHER_SUITE_CCMP:
 549         case WLAN_CIPHER_SUITE_CCMP_256:
 550                 ieee80211_aes_key_free(key->u.ccmp.tfm);
 551                 break;
 552         case WLAN_CIPHER_SUITE_AES_CMAC:
 553         case WLAN_CIPHER_SUITE_BIP_CMAC_256:
 554                 ieee80211_aes_cmac_key_free(key->u.aes_cmac.tfm);
 555                 break;
 556         case WLAN_CIPHER_SUITE_BIP_GMAC_128:
 557         case WLAN_CIPHER_SUITE_BIP_GMAC_256:
 558                 ieee80211_aes_gmac_key_free(key->u.aes_gmac.tfm);
 559                 break;
 560         case WLAN_CIPHER_SUITE_GCMP:
 561         case WLAN_CIPHER_SUITE_GCMP_256:
 562                 ieee80211_aes_gcm_key_free(key->u.gcmp.tfm);
 563                 break;
 564         }
 565         kzfree(key);
 566 }
 567
 568 static void __ieee80211_key_destroy(struct ieee80211_key *key,
 569                                     bool delay_tailroom)
 570 {
 571         if (key->local)
 572                 ieee80211_key_disable_hw_accel(key);
 573
 574         if (key->local) {
 575                 struct ieee80211_sub_if_data *sdata = key->sdata;
 576
 577                 ieee80211_debugfs_key_remove(key);
 578
 579                 if (delay_tailroom) {
 580                         /* see ieee80211_delayed_tailroom_dec */
 581                         sdata->crypto_tx_tailroom_pending_dec++;
 582                         schedule_delayed_work(&sdata->dec_tailroom_needed_wk,
 583                                               HZ/2);
 584                 } else {
 585                         decrease_tailroom_need_count(sdata, 1);
 586                 }
 587         }
 588
 589         ieee80211_key_free_common(key);
 590 }
 591
 592 static void ieee80211_key_destroy(struct ieee80211_key *key,
 593                                   bool delay_tailroom)
 594 {
 595         if (!key)
 596                 return;
 597
 598         /*
 599          * Synchronize so the TX path and rcu key iterators
 600          * can no longer be using this key before we free/remove it.
 601          */
 602         synchronize_net();
 603
 604         __ieee80211_key_destroy(key, delay_tailroom);
 605 }
 606
 607 void ieee80211_key_free_unused(struct ieee80211_key *key)
 608 {
 609         WARN_ON(key->sdata || key->local);
 610         ieee80211_key_free_common(key);
 611 }
 612
 613 int ieee80211_key_link(struct ieee80211_key *key,
 614                        struct ieee80211_sub_if_data *sdata,
 615                        struct sta_info *sta)
 616 {
 617         struct ieee80211_local *local = sdata->local;
 618         struct ieee80211_key *old_key;
 619         int idx, ret;
 620         bool pairwise;
 621
 622         pairwise = key->conf.flags & IEEE80211_KEY_FLAG_PAIRWISE;
 623         idx = key->conf.keyidx;
 624
 625         mutex_lock(&sdata->local->key_mtx);
 626
 627         if (sta && pairwise)
 628                 old_key = key_mtx_dereference(sdata->local, sta->ptk[idx]);
 629         else if (sta)
 630                 old_key = key_mtx_dereference(sdata->local, sta->gtk[idx]);
 631         else
 632                 old_key = key_mtx_dereference(sdata->local, sdata->keys[idx]);
 633
 634         /*
 635          * Silently accept key re-installation without really installing the
 636          * new version of the key to avoid nonce reuse or replay issues.
 637          */
 638         if (old_key && key->conf.keylen == old_key->conf.keylen &&
 639             !crypto_memneq(key->conf.key, old_key->conf.key, key->conf.keylen)) {
 640                 ieee80211_key_free_unused(key);
 641                 ret = 0;
 642                 goto out;
 643         }
 644
 645         key->local = sdata->local;
 646         key->sdata = sdata;
 647         key->sta = sta;
 648
 649         increment_tailroom_need_count(sdata);
 650
 651         ieee80211_key_replace(sdata, sta, pairwise, old_key, key);
 652         ieee80211_key_destroy(old_key, true);
 653
 654         ieee80211_debugfs_key_add(key);
 655
 656         if (!local->wowlan) {
 657                 ret = ieee80211_key_enable_hw_accel(key);
 658                 if (ret)
 659                         ieee80211_key_free(key, true);
 660         } else {
 661                 ret = 0;
 662         }
 663
 664  out:
 665         mutex_unlock(&sdata->local->key_mtx);
 666
 667         return ret;
 668 }
 669
 670 void ieee80211_key_free(struct ieee80211_key *key, bool delay_tailroom)
 671 {
 672         if (!key)
 673                 return;
 674
 675         /*
 676          * Replace key with nothingness if it was ever used.
 677          */
 678         if (key->sdata)
 679                 ieee80211_key_replace(key->sdata, key->sta,
 680                                 key->conf.flags & IEEE80211_KEY_FLAG_PAIRWISE,
 681                                 key, NULL);
 682         ieee80211_key_destroy(key, delay_tailroom);
 683 }
 684
 685 void ieee80211_enable_keys(struct ieee80211_sub_if_data *sdata)
 686 {
 687         struct ieee80211_key *key;
 688         struct ieee80211_sub_if_data *vlan;
 689
 690         ASSERT_RTNL();
 691
 692         if (WARN_ON(!ieee80211_sdata_running(sdata)))
 693                 return;
 694
 695         mutex_lock(&sdata->local->key_mtx);
 696
 697         WARN_ON_ONCE(sdata->crypto_tx_tailroom_needed_cnt ||
 698                      sdata->crypto_tx_tailroom_pending_dec);
 699
 700         if (sdata->vif.type == NL80211_IFTYPE_AP) {
 701                 list_for_each_entry(vlan, &sdata->u.ap.vlans, u.vlan.list)
 702                         WARN_ON_ONCE(vlan->crypto_tx_tailroom_needed_cnt ||
 703                                      vlan->crypto_tx_tailroom_pending_dec);
 704         }
 705
 706         list_for_each_entry(key, &sdata->key_list, list) {
 707                 increment_tailroom_need_count(sdata);
 708                 ieee80211_key_enable_hw_accel(key);
 709         }
 710
 711         mutex_unlock(&sdata->local->key_mtx);
 712 }
 713
 714 void ieee80211_reset_crypto_tx_tailroom(struct ieee80211_sub_if_data *sdata)
 715 {
 716         struct ieee80211_sub_if_data *vlan;
 717
 718         mutex_lock(&sdata->local->key_mtx);
 719
 720         sdata->crypto_tx_tailroom_needed_cnt = 0;
 721
 722         if (sdata->vif.type == NL80211_IFTYPE_AP) {
 723                 list_for_each_entry(vlan, &sdata->u.ap.vlans, u.vlan.list)
 724                         vlan->crypto_tx_tailroom_needed_cnt = 0;
 725         }
 726
 727         mutex_unlock(&sdata->local->key_mtx);
 728 }
 729
 730 void ieee80211_iter_keys(struct ieee80211_hw *hw,
 731                          struct ieee80211_vif *vif,
 732                          void (*iter)(struct ieee80211_hw *hw,
 733                                       struct ieee80211_vif *vif,
 734                                       struct ieee80211_sta *sta,
 735                                       struct ieee80211_key_conf *key,
 736                                       void *data),
 737                          void *iter_data)
 738 {
 739         struct ieee80211_local *local = hw_to_local(hw);
 740         struct ieee80211_key *key, *tmp;
 741         struct ieee80211_sub_if_data *sdata;
 742
 743         ASSERT_RTNL();
 744
 745         mutex_lock(&local->key_mtx);
 746         if (vif) {
 747                 sdata = vif_to_sdata(vif);
 748                 list_for_each_entry_safe(key, tmp, &sdata->key_list, list)
 749                         iter(hw, &sdata->vif,
 750                              key->sta ? &key->sta->sta : NULL,
 751                              &key->conf, iter_data);
 752         } else {
 753                 list_for_each_entry(sdata, &local->interfaces, list)
 754                         list_for_each_entry_safe(key, tmp,
 755                                                  &sdata->key_list, list)
 756                                 iter(hw, &sdata->vif,
 757                                      key->sta ? &key->sta->sta : NULL,
 758                                      &key->conf, iter_data);
 759         }
 760         mutex_unlock(&local->key_mtx);
 761 }
 762 EXPORT_SYMBOL(ieee80211_iter_keys);
 763
 764 static void
 765 _ieee80211_iter_keys_rcu(struct ieee80211_hw *hw,
 766                          struct ieee80211_sub_if_data *sdata,
 767                          void (*iter)(struct ieee80211_hw *hw,
 768                                       struct ieee80211_vif *vif,
 769                                       struct ieee80211_sta *sta,
 770                                       struct ieee80211_key_conf *key,
 771                                       void *data),
 772                          void *iter_data)
 773 {
 774         struct ieee80211_key *key;
 775
 776         list_for_each_entry_rcu(key, &sdata->key_list, list) {
 777                 /* skip keys of station in removal process */
 778                 if (key->sta && key->sta->removed)
 779                         continue;
 780                 if (!(key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE))
 781                         continue;
 782
 783                 iter(hw, &sdata->vif,
 784                      key->sta ? &key->sta->sta : NULL,
 785                      &key->conf, iter_data);
 786         }
 787 }
 788
 789 void ieee80211_iter_keys_rcu(struct ieee80211_hw *hw,
 790                              struct ieee80211_vif *vif,
 791                              void (*iter)(struct ieee80211_hw *hw,
 792                                           struct ieee80211_vif *vif,
 793                                           struct ieee80211_sta *sta,
 794                                           struct ieee80211_key_conf *key,
 795                                           void *data),
 796                              void *iter_data)
 797 {
 798         struct ieee80211_local *local = hw_to_local(hw);
 799         struct ieee80211_sub_if_data *sdata;
 800
 801         if (vif) {
 802                 sdata = vif_to_sdata(vif);
 803                 _ieee80211_iter_keys_rcu(hw, sdata, iter, iter_data);
 804         } else {
 805                 list_for_each_entry_rcu(sdata, &local->interfaces, list)
 806                         _ieee80211_iter_keys_rcu(hw, sdata, iter, iter_data);
 807         }
 808 }
 809 EXPORT_SYMBOL(ieee80211_iter_keys_rcu);
 810
 811 static void ieee80211_free_keys_iface(struct ieee80211_sub_if_data *sdata,
 812                                       struct list_head *keys)
 813 {
 814         struct ieee80211_key *key, *tmp;
 815
 816         decrease_tailroom_need_count(sdata,
 817                                      sdata->crypto_tx_tailroom_pending_dec);
 818         sdata->crypto_tx_tailroom_pending_dec = 0;
 819
 820         ieee80211_debugfs_key_remove_mgmt_default(sdata);
 821
 822         list_for_each_entry_safe(key, tmp, &sdata->key_list, list) {
 823                 ieee80211_key_replace(key->sdata, key->sta,
 824                                 key->conf.flags & IEEE80211_KEY_FLAG_PAIRWISE,
 825                                 key, NULL);
 826                 list_add_tail(&key->list, keys);
 827         }
 828
 829         ieee80211_debugfs_key_update_default(sdata);
 830 }
 831
 832 void ieee80211_free_keys(struct ieee80211_sub_if_data *sdata,
 833                          bool force_synchronize)
 834 {
 835         struct ieee80211_local *local = sdata->local;
 836         struct ieee80211_sub_if_data *vlan;
 837         struct ieee80211_sub_if_data *master;
 838         struct ieee80211_key *key, *tmp;
 839         LIST_HEAD(keys);
 840
 841         cancel_delayed_work_sync(&sdata->dec_tailroom_needed_wk);
 842
 843         mutex_lock(&local->key_mtx);
 844
 845         ieee80211_free_keys_iface(sdata, &keys);
 846
 847         if (sdata->vif.type == NL80211_IFTYPE_AP) {
 848                 list_for_each_entry(vlan, &sdata->u.ap.vlans, u.vlan.list)
 849                         ieee80211_free_keys_iface(vlan, &keys);
 850         }
 851
 852         if (!list_empty(&keys) || force_synchronize)
 853                 synchronize_net();
 854         list_for_each_entry_safe(key, tmp, &keys, list)
 855                 __ieee80211_key_destroy(key, false);
 856
 857         if (sdata->vif.type == NL80211_IFTYPE_AP_VLAN) {
 858                 if (sdata->bss) {
 859                         master = container_of(sdata->bss,
 860                                               struct ieee80211_sub_if_data,
 861                                               u.ap);
 862
 863                         WARN_ON_ONCE(sdata->crypto_tx_tailroom_needed_cnt !=
 864                                      master->crypto_tx_tailroom_needed_cnt);
 865                 }
 866         } else {
 867                 WARN_ON_ONCE(sdata->crypto_tx_tailroom_needed_cnt ||
 868                              sdata->crypto_tx_tailroom_pending_dec);
 869         }
 870
 871         if (sdata->vif.type == NL80211_IFTYPE_AP) {
 872                 list_for_each_entry(vlan, &sdata->u.ap.vlans, u.vlan.list)
 873                         WARN_ON_ONCE(vlan->crypto_tx_tailroom_needed_cnt ||
 874                                      vlan->crypto_tx_tailroom_pending_dec);
 875         }
 876
 877         mutex_unlock(&local->key_mtx);
 878 }
 879
 880 void ieee80211_free_sta_keys(struct ieee80211_local *local,
 881                              struct sta_info *sta)
 882 {
 883         struct ieee80211_key *key;
 884         int i;
 885
 886         mutex_lock(&local->key_mtx);
 887         for (i = 0; i < ARRAY_SIZE(sta->gtk); i++) {
 888                 key = key_mtx_dereference(local, sta->gtk[i]);
 889                 if (!key)
 890                         continue;
 891                 ieee80211_key_replace(key->sdata, key->sta,
 892                                 key->conf.flags & IEEE80211_KEY_FLAG_PAIRWISE,
 893                                 key, NULL);
 894                 __ieee80211_key_destroy(key, true);
 895         }
 896
 897         for (i = 0; i < NUM_DEFAULT_KEYS; i++) {
 898                 key = key_mtx_dereference(local, sta->ptk[i]);
 899                 if (!key)
 900                         continue;
 901                 ieee80211_key_replace(key->sdata, key->sta,
 902                                 key->conf.flags & IEEE80211_KEY_FLAG_PAIRWISE,
 903                                 key, NULL);
 904                 __ieee80211_key_destroy(key, true);
 905         }
 906
 907         mutex_unlock(&local->key_mtx);
 908 }
 909
 910 void ieee80211_delayed_tailroom_dec(struct work_struct *wk)
 911 {
 912         struct ieee80211_sub_if_data *sdata;
 913
 914         sdata = container_of(wk, struct ieee80211_sub_if_data,
 915                              dec_tailroom_needed_wk.work);
 916
 917         /*
 918          * The reason for the delayed tailroom needed decrementing is to
 919          * make roaming faster: during roaming, all keys are first deleted
 920          * and then new keys are installed. The first new key causes the
 921          * crypto_tx_tailroom_needed_cnt to go from 0 to 1, which invokes
 922          * the cost of synchronize_net() (which can be slow). Avoid this
 923          * by deferring the crypto_tx_tailroom_needed_cnt decrementing on
 924          * key removal for a while, so if we roam the value is larger than
 925          * zero and no 0->1 transition happens.
 926          *
 927          * The cost is that if the AP switching was from an AP with keys
 928          * to one without, we still allocate tailroom while it would no
 929          * longer be needed. However, in the typical (fast) roaming case
 930          * within an ESS this usually won't happen.
 931          */
 932
 933         mutex_lock(&sdata->local->key_mtx);
 934         decrease_tailroom_need_count(sdata,
 935                                      sdata->crypto_tx_tailroom_pending_dec);
 936         sdata->crypto_tx_tailroom_pending_dec = 0;
 937         mutex_unlock(&sdata->local->key_mtx);
 938 }
 939
 940 void ieee80211_gtk_rekey_notify(struct ieee80211_vif *vif, const u8 *bssid,
 941                                 const u8 *replay_ctr, gfp_t gfp)
 942 {
 943         struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
 944
 945         trace_api_gtk_rekey_notify(sdata, bssid, replay_ctr);
 946
 947         cfg80211_gtk_rekey_notify(sdata->dev, bssid, replay_ctr, gfp);
 948 }
 949 EXPORT_SYMBOL_GPL(ieee80211_gtk_rekey_notify);
 950
 951 void ieee80211_get_key_rx_seq(struct ieee80211_key_conf *keyconf,
 952                               int tid, struct ieee80211_key_seq *seq)
 953 {
 954         struct ieee80211_key *key;
 955         const u8 *pn;
 956
 957         key = container_of(keyconf, struct ieee80211_key, conf);
 958
 959         switch (key->conf.cipher) {
 960         case WLAN_CIPHER_SUITE_TKIP:
 961                 if (WARN_ON(tid < 0 || tid >= IEEE80211_NUM_TIDS))
 962                         return;
 963                 seq->tkip.iv32 = key->u.tkip.rx[tid].iv32;
 964                 seq->tkip.iv16 = key->u.tkip.rx[tid].iv16;
 965                 break;
 966         case WLAN_CIPHER_SUITE_CCMP:
 967         case WLAN_CIPHER_SUITE_CCMP_256:
 968                 if (WARN_ON(tid < -1 || tid >= IEEE80211_NUM_TIDS))
 969                         return;
 970                 if (tid < 0)
 971                         pn = key->u.ccmp.rx_pn[IEEE80211_NUM_TIDS];
 972                 else
 973                         pn = key->u.ccmp.rx_pn[tid];
 974                 memcpy(seq->ccmp.pn, pn, IEEE80211_CCMP_PN_LEN);
 975                 break;
 976         case WLAN_CIPHER_SUITE_AES_CMAC:
 977         case WLAN_CIPHER_SUITE_BIP_CMAC_256:
 978                 if (WARN_ON(tid != 0))
 979                         return;
 980                 pn = key->u.aes_cmac.rx_pn;
 981                 memcpy(seq->aes_cmac.pn, pn, IEEE80211_CMAC_PN_LEN);
 982                 break;
 983         case WLAN_CIPHER_SUITE_BIP_GMAC_128:
 984         case WLAN_CIPHER_SUITE_BIP_GMAC_256:
 985                 if (WARN_ON(tid != 0))
 986                         return;
 987                 pn = key->u.aes_gmac.rx_pn;
 988                 memcpy(seq->aes_gmac.pn, pn, IEEE80211_GMAC_PN_LEN);
 989                 break;
 990         case WLAN_CIPHER_SUITE_GCMP:
 991         case WLAN_CIPHER_SUITE_GCMP_256:
 992                 if (WARN_ON(tid < -1 || tid >= IEEE80211_NUM_TIDS))
 993                         return;
 994                 if (tid < 0)
 995                         pn = key->u.gcmp.rx_pn[IEEE80211_NUM_TIDS];
 996                 else
 997                         pn = key->u.gcmp.rx_pn[tid];
 998                 memcpy(seq->gcmp.pn, pn, IEEE80211_GCMP_PN_LEN);
 999                 break;
1000         }
1001 }
1002 EXPORT_SYMBOL(ieee80211_get_key_rx_seq);
1003
1004 void ieee80211_set_key_rx_seq(struct ieee80211_key_conf *keyconf,
1005                               int tid, struct ieee80211_key_seq *seq)
1006 {
1007         struct ieee80211_key *key;
1008         u8 *pn;
1009
1010         key = container_of(keyconf, struct ieee80211_key, conf);
1011
1012         switch (key->conf.cipher) {
1013         case WLAN_CIPHER_SUITE_TKIP:
1014                 if (WARN_ON(tid < 0 || tid >= IEEE80211_NUM_TIDS))
1015                         return;
1016                 key->u.tkip.rx[tid].iv32 = seq->tkip.iv32;
1017                 key->u.tkip.rx[tid].iv16 = seq->tkip.iv16;
1018                 break;
1019         case WLAN_CIPHER_SUITE_CCMP:
1020         case WLAN_CIPHER_SUITE_CCMP_256:
1021                 if (WARN_ON(tid < -1 || tid >= IEEE80211_NUM_TIDS))
1022                         return;
1023                 if (tid < 0)
1024                         pn = key->u.ccmp.rx_pn[IEEE80211_NUM_TIDS];
1025                 else
1026                         pn = key->u.ccmp.rx_pn[tid];
1027                 memcpy(pn, seq->ccmp.pn, IEEE80211_CCMP_PN_LEN);
1028                 break;
1029         case WLAN_CIPHER_SUITE_AES_CMAC:
1030         case WLAN_CIPHER_SUITE_BIP_CMAC_256:
1031                 if (WARN_ON(tid != 0))
1032                         return;
1033                 pn = key->u.aes_cmac.rx_pn;
1034                 memcpy(pn, seq->aes_cmac.pn, IEEE80211_CMAC_PN_LEN);
1035                 break;
1036         case WLAN_CIPHER_SUITE_BIP_GMAC_128:
1037         case WLAN_CIPHER_SUITE_BIP_GMAC_256:
1038                 if (WARN_ON(tid != 0))
1039                         return;
1040                 pn = key->u.aes_gmac.rx_pn;
1041                 memcpy(pn, seq->aes_gmac.pn, IEEE80211_GMAC_PN_LEN);
1042                 break;
1043         case WLAN_CIPHER_SUITE_GCMP:
1044         case WLAN_CIPHER_SUITE_GCMP_256:
1045                 if (WARN_ON(tid < -1 || tid >= IEEE80211_NUM_TIDS))
1046                         return;
1047                 if (tid < 0)
1048                         pn = key->u.gcmp.rx_pn[IEEE80211_NUM_TIDS];
1049                 else
1050                         pn = key->u.gcmp.rx_pn[tid];
1051                 memcpy(pn, seq->gcmp.pn, IEEE80211_GCMP_PN_LEN);
1052                 break;
1053         default:
1054                 WARN_ON(1);
1055                 break;
1056         }
1057 }
1058 EXPORT_SYMBOL_GPL(ieee80211_set_key_rx_seq);
1059
1060 void ieee80211_remove_key(struct ieee80211_key_conf *keyconf)
1061 {
1062         struct ieee80211_key *key;
1063
1064         key = container_of(keyconf, struct ieee80211_key, conf);
1065
1066         assert_key_lock(key->local);
1067
1068         /*
1069          * if key was uploaded, we assume the driver will/has remove(d)
1070          * it, so adjust bookkeeping accordingly
1071          */
1072         if (key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE) {
1073                 key->flags &= ~KEY_FLAG_UPLOADED_TO_HARDWARE;
1074
1075                 if (!((key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_MMIC) ||
1076                       (key->conf.flags & IEEE80211_KEY_FLAG_RESERVE_TAILROOM)))
1077                         increment_tailroom_need_count(key->sdata);
1078         }
1079
1080         ieee80211_key_free(key, false);
1081 }
1082 EXPORT_SYMBOL_GPL(ieee80211_remove_key);
1083
1084 struct ieee80211_key_conf *
1085 ieee80211_gtk_rekey_add(struct ieee80211_vif *vif,
1086                         struct ieee80211_key_conf *keyconf)
1087 {
1088         struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
1089         struct ieee80211_local *local = sdata->local;
1090         struct ieee80211_key *key;
1091         int err;
1092
1093         if (WARN_ON(!local->wowlan))
1094                 return ERR_PTR(-EINVAL);
1095
1096         if (WARN_ON(vif->type != NL80211_IFTYPE_STATION))
1097                 return ERR_PTR(-EINVAL);
1098
1099         key = ieee80211_key_alloc(keyconf->cipher, keyconf->keyidx,
1100                                   keyconf->keylen, keyconf->key,
1101                                   0, NULL, NULL);
1102         if (IS_ERR(key))
1103                 return ERR_CAST(key);
1104
1105         if (sdata->u.mgd.mfp != IEEE80211_MFP_DISABLED)
1106                 key->conf.flags |= IEEE80211_KEY_FLAG_RX_MGMT;
1107
1108         err = ieee80211_key_link(key, sdata, NULL);
1109         if (err)
1110                 return ERR_PTR(err);
1111
1112         return &key->conf;
1113 }
1114 EXPORT_SYMBOL_GPL(ieee80211_gtk_rekey_add);