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  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License version 2 as
   9  * published by the Free Software Foundation.
  10  */
  11
  12 #include <linux/if_ether.h>
  13 #include <linux/etherdevice.h>
  14 #include <linux/list.h>
  15 #include <linux/rcupdate.h>
  16 #include <linux/rtnetlink.h>
  17 #include <linux/slab.h>
  18 #include <linux/export.h>
  19 #include <net/mac80211.h>
  20 #include <asm/unaligned.h>
  21 #include "ieee80211_i.h"
  22 #include "driver-ops.h"
  23 #include "debugfs_key.h"
  24 #include "aes_ccm.h"
  25 #include "aes_cmac.h"
  26
  27
  28 /**
  29  * DOC: Key handling basics
  30  *
  31  * Key handling in mac80211 is done based on per-interface (sub_if_data)
  32  * keys and per-station keys. Since each station belongs to an interface,
  33  * each station key also belongs to that interface.
  34  *
  35  * Hardware acceleration is done on a best-effort basis for algorithms
  36  * that are implemented in software,  for each key the hardware is asked
  37  * to enable that key for offloading but if it cannot do that the key is
  38  * simply kept for software encryption (unless it is for an algorithm
  39  * that isn't implemented in software).
  40  * There is currently no way of knowing whether a key is handled in SW
  41  * or HW except by looking into debugfs.
  42  *
  43  * All key management is internally protected by a mutex. Within all
  44  * other parts of mac80211, key references are, just as STA structure
  45  * references, protected by RCU. Note, however, that some things are
  46  * unprotected, namely the key->sta dereferences within the hardware
  47  * acceleration functions. This means that sta_info_destroy() must
  48  * remove the key which waits for an RCU grace period.
  49  */
  50
  51 static const u8 bcast_addr[ETH_ALEN] = { 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF };
  52
  53 static void assert_key_lock(struct ieee80211_local *local)
  54 {
  55         lockdep_assert_held(&local->key_mtx);
  56 }
  57
  58 static void increment_tailroom_need_count(struct ieee80211_sub_if_data *sdata)
  59 {
  60         /*
  61          * When this count is zero, SKB resizing for allocating tailroom
  62          * for IV or MMIC is skipped. But, this check has created two race
  63          * cases in xmit path while transiting from zero count to one:
  64          *
  65          * 1. SKB resize was skipped because no key was added but just before
  66          * the xmit key is added and SW encryption kicks off.
  67          *
  68          * 2. SKB resize was skipped because all the keys were hw planted but
  69          * just before xmit one of the key is deleted and SW encryption kicks
  70          * off.
  71          *
  72          * In both the above case SW encryption will find not enough space for
  73          * tailroom and exits with WARN_ON. (See WARN_ONs at wpa.c)
  74          *
  75          * Solution has been explained at
  76          * http://mid.gmane.org/1308590980.4322.19.camel@jlt3.sipsolutions.net
  77          */
  78
  79         if (!sdata->crypto_tx_tailroom_needed_cnt++) {
  80                 /*
  81                  * Flush all XMIT packets currently using HW encryption or no
  82                  * encryption at all if the count transition is from 0 -> 1.
  83                  */
  84                 synchronize_net();
  85         }
  86 }
  87
  88 static int ieee80211_key_enable_hw_accel(struct ieee80211_key *key)
  89 {
  90         struct ieee80211_sub_if_data *sdata;
  91         struct sta_info *sta;
  92         int ret;
  93
  94         might_sleep();
  95
  96         if (key->flags & KEY_FLAG_TAINTED)
  97                 return -EINVAL;
  98
  99         if (!key->local->ops->set_key)
 100                 goto out_unsupported;
 101
 102         assert_key_lock(key->local);
 103
 104         sta = key->sta;
 105
 106         /*
 107          * If this is a per-STA GTK, check if it
 108          * is supported; if not, return.
 109          */
 110         if (sta && !(key->conf.flags & IEEE80211_KEY_FLAG_PAIRWISE) &&
 111             !(key->local->hw.flags & IEEE80211_HW_SUPPORTS_PER_STA_GTK))
 112                 goto out_unsupported;
 113
 114         if (sta && !sta->uploaded)
 115                 goto out_unsupported;
 116
 117         sdata = key->sdata;
 118         if (sdata->vif.type == NL80211_IFTYPE_AP_VLAN) {
 119                 /*
 120                  * The driver doesn't know anything about VLAN interfaces.
 121                  * Hence, don't send GTKs for VLAN interfaces to the driver.
 122                  */
 123                 if (!(key->conf.flags & IEEE80211_KEY_FLAG_PAIRWISE))
 124                         goto out_unsupported;
 125         }
 126
 127         ret = drv_set_key(key->local, SET_KEY, sdata,
 128                           sta ? &sta->sta : NULL, &key->conf);
 129
 130         if (!ret) {
 131                 key->flags |= KEY_FLAG_UPLOADED_TO_HARDWARE;
 132
 133                 if (!((key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_MMIC) ||
 134                       (key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_IV) ||
 135                       (key->conf.flags & IEEE80211_KEY_FLAG_PUT_IV_SPACE)))
 136                         sdata->crypto_tx_tailroom_needed_cnt--;
 137
 138                 WARN_ON((key->conf.flags & IEEE80211_KEY_FLAG_PUT_IV_SPACE) &&
 139                         (key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_IV));
 140
 141                 return 0;
 142         }
 143
 144         if (ret != -ENOSPC && ret != -EOPNOTSUPP)
 145                 sdata_err(sdata,
 146                           "failed to set key (%d, %pM) to hardware (%d)\n",
 147                           key->conf.keyidx,
 148                           sta ? sta->sta.addr : bcast_addr, ret);
 149
 150  out_unsupported:
 151         switch (key->conf.cipher) {
 152         case WLAN_CIPHER_SUITE_WEP40:
 153         case WLAN_CIPHER_SUITE_WEP104:
 154         case WLAN_CIPHER_SUITE_TKIP:
 155         case WLAN_CIPHER_SUITE_CCMP:
 156         case WLAN_CIPHER_SUITE_AES_CMAC:
 157                 /* all of these we can do in software */
 158                 return 0;
 159         default:
 160                 return -EINVAL;
 161         }
 162 }
 163
 164 static void ieee80211_key_disable_hw_accel(struct ieee80211_key *key)
 165 {
 166         struct ieee80211_sub_if_data *sdata;
 167         struct sta_info *sta;
 168         int ret;
 169
 170         might_sleep();
 171
 172         if (!key || !key->local->ops->set_key)
 173                 return;
 174
 175         assert_key_lock(key->local);
 176
 177         if (!(key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE))
 178                 return;
 179
 180         sta = key->sta;
 181         sdata = key->sdata;
 182
 183         if (!((key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_MMIC) ||
 184               (key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_IV) ||
 185               (key->conf.flags & IEEE80211_KEY_FLAG_PUT_IV_SPACE)))
 186                 increment_tailroom_need_count(sdata);
 187
 188         ret = drv_set_key(key->local, DISABLE_KEY, sdata,
 189                           sta ? &sta->sta : NULL, &key->conf);
 190
 191         if (ret)
 192                 sdata_err(sdata,
 193                           "failed to remove key (%d, %pM) from hardware (%d)\n",
 194                           key->conf.keyidx,
 195                           sta ? sta->sta.addr : bcast_addr, ret);
 196
 197         key->flags &= ~KEY_FLAG_UPLOADED_TO_HARDWARE;
 198 }
 199
 200 static void __ieee80211_set_default_key(struct ieee80211_sub_if_data *sdata,
 201                                         int idx, bool uni, bool multi)
 202 {
 203         struct ieee80211_key *key = NULL;
 204
 205         assert_key_lock(sdata->local);
 206
 207         if (idx >= 0 && idx < NUM_DEFAULT_KEYS)
 208                 key = key_mtx_dereference(sdata->local, sdata->keys[idx]);
 209
 210         if (uni) {
 211                 rcu_assign_pointer(sdata->default_unicast_key, key);
 212                 drv_set_default_unicast_key(sdata->local, sdata, idx);
 213         }
 214
 215         if (multi)
 216                 rcu_assign_pointer(sdata->default_multicast_key, key);
 217
 218         ieee80211_debugfs_key_update_default(sdata);
 219 }
 220
 221 void ieee80211_set_default_key(struct ieee80211_sub_if_data *sdata, int idx,
 222                                bool uni, bool multi)
 223 {
 224         mutex_lock(&sdata->local->key_mtx);
 225         __ieee80211_set_default_key(sdata, idx, uni, multi);
 226         mutex_unlock(&sdata->local->key_mtx);
 227 }
 228
 229 static void
 230 __ieee80211_set_default_mgmt_key(struct ieee80211_sub_if_data *sdata, int idx)
 231 {
 232         struct ieee80211_key *key = NULL;
 233
 234         assert_key_lock(sdata->local);
 235
 236         if (idx >= NUM_DEFAULT_KEYS &&
 237             idx < NUM_DEFAULT_KEYS + NUM_DEFAULT_MGMT_KEYS)
 238                 key = key_mtx_dereference(sdata->local, sdata->keys[idx]);
 239
 240         rcu_assign_pointer(sdata->default_mgmt_key, key);
 241
 242         ieee80211_debugfs_key_update_default(sdata);
 243 }
 244
 245 void ieee80211_set_default_mgmt_key(struct ieee80211_sub_if_data *sdata,
 246                                     int idx)
 247 {
 248         mutex_lock(&sdata->local->key_mtx);
 249         __ieee80211_set_default_mgmt_key(sdata, idx);
 250         mutex_unlock(&sdata->local->key_mtx);
 251 }
 252
 253
 254 static void ieee80211_key_replace(struct ieee80211_sub_if_data *sdata,
 255                                   struct sta_info *sta,
 256                                   bool pairwise,
 257                                   struct ieee80211_key *old,
 258                                   struct ieee80211_key *new)
 259 {
 260         int idx;
 261         bool defunikey, defmultikey, defmgmtkey;
 262
 263         /* caller must provide at least one old/new */
 264         if (WARN_ON(!new && !old))
 265                 return;
 266
 267         if (new)
 268                 list_add_tail(&new->list, &sdata->key_list);
 269
 270         WARN_ON(new && old && new->conf.keyidx != old->conf.keyidx);
 271
 272         if (old)
 273                 idx = old->conf.keyidx;
 274         else
 275                 idx = new->conf.keyidx;
 276
 277         if (sta) {
 278                 if (pairwise) {
 279                         rcu_assign_pointer(sta->ptk[idx], new);
 280                         sta->ptk_idx = idx;
 281                 } else {
 282                         rcu_assign_pointer(sta->gtk[idx], new);
 283                         sta->gtk_idx = idx;
 284                 }
 285         } else {
 286                 defunikey = old &&
 287                         old == key_mtx_dereference(sdata->local,
 288                                                 sdata->default_unicast_key);
 289                 defmultikey = old &&
 290                         old == key_mtx_dereference(sdata->local,
 291                                                 sdata->default_multicast_key);
 292                 defmgmtkey = old &&
 293                         old == key_mtx_dereference(sdata->local,
 294                                                 sdata->default_mgmt_key);
 295
 296                 if (defunikey && !new)
 297                         __ieee80211_set_default_key(sdata, -1, true, false);
 298                 if (defmultikey && !new)
 299                         __ieee80211_set_default_key(sdata, -1, false, true);
 300                 if (defmgmtkey && !new)
 301                         __ieee80211_set_default_mgmt_key(sdata, -1);
 302
 303                 rcu_assign_pointer(sdata->keys[idx], new);
 304                 if (defunikey && new)
 305                         __ieee80211_set_default_key(sdata, new->conf.keyidx,
 306                                                     true, false);
 307                 if (defmultikey && new)
 308                         __ieee80211_set_default_key(sdata, new->conf.keyidx,
 309                                                     false, true);
 310                 if (defmgmtkey && new)
 311                         __ieee80211_set_default_mgmt_key(sdata,
 312                                                          new->conf.keyidx);
 313         }
 314
 315         if (old)
 316                 list_del(&old->list);
 317 }
 318
 319 struct ieee80211_key *
 320 ieee80211_key_alloc(u32 cipher, int idx, size_t key_len,
 321                     const u8 *key_data,
 322                     size_t seq_len, const u8 *seq,
 323                     const struct ieee80211_cipher_scheme *cs)
 324 {
 325         struct ieee80211_key *key;
 326         int i, j, err;
 327
 328         if (WARN_ON(idx < 0 || idx >= NUM_DEFAULT_KEYS + NUM_DEFAULT_MGMT_KEYS))
 329                 return ERR_PTR(-EINVAL);
 330
 331         key = kzalloc(sizeof(struct ieee80211_key) + key_len, GFP_KERNEL);
 332         if (!key)
 333                 return ERR_PTR(-ENOMEM);
 334
 335         /*
 336          * Default to software encryption; we'll later upload the
 337          * key to the hardware if possible.
 338          */
 339         key->conf.flags = 0;
 340         key->flags = 0;
 341
 342         key->conf.cipher = cipher;
 343         key->conf.keyidx = idx;
 344         key->conf.keylen = key_len;
 345         switch (cipher) {
 346         case WLAN_CIPHER_SUITE_WEP40:
 347         case WLAN_CIPHER_SUITE_WEP104:
 348                 key->conf.iv_len = IEEE80211_WEP_IV_LEN;
 349                 key->conf.icv_len = IEEE80211_WEP_ICV_LEN;
 350                 break;
 351         case WLAN_CIPHER_SUITE_TKIP:
 352                 key->conf.iv_len = IEEE80211_TKIP_IV_LEN;
 353                 key->conf.icv_len = IEEE80211_TKIP_ICV_LEN;
 354                 if (seq) {
 355                         for (i = 0; i < IEEE80211_NUM_TIDS; i++) {
 356                                 key->u.tkip.rx[i].iv32 =
 357                                         get_unaligned_le32(&seq[2]);
 358                                 key->u.tkip.rx[i].iv16 =
 359                                         get_unaligned_le16(seq);
 360                         }
 361                 }
 362                 spin_lock_init(&key->u.tkip.txlock);
 363                 break;
 364         case WLAN_CIPHER_SUITE_CCMP:
 365                 key->conf.iv_len = IEEE80211_CCMP_HDR_LEN;
 366                 key->conf.icv_len = IEEE80211_CCMP_MIC_LEN;
 367                 if (seq) {
 368                         for (i = 0; i < IEEE80211_NUM_TIDS + 1; i++)
 369                                 for (j = 0; j < IEEE80211_CCMP_PN_LEN; j++)
 370                                         key->u.ccmp.rx_pn[i][j] =
 371                                                 seq[IEEE80211_CCMP_PN_LEN - j - 1];
 372                 }
 373                 /*
 374                  * Initialize AES key state here as an optimization so that
 375                  * it does not need to be initialized for every packet.
 376                  */
 377                 key->u.ccmp.tfm = ieee80211_aes_key_setup_encrypt(key_data);
 378                 if (IS_ERR(key->u.ccmp.tfm)) {
 379                         err = PTR_ERR(key->u.ccmp.tfm);
 380                         kfree(key);
 381                         return ERR_PTR(err);
 382                 }
 383                 break;
 384         case WLAN_CIPHER_SUITE_AES_CMAC:
 385                 key->conf.iv_len = 0;
 386                 key->conf.icv_len = sizeof(struct ieee80211_mmie);
 387                 if (seq)
 388                         for (j = 0; j < IEEE80211_CMAC_PN_LEN; j++)
 389                                 key->u.aes_cmac.rx_pn[j] =
 390                                         seq[IEEE80211_CMAC_PN_LEN - j - 1];
 391                 /*
 392                  * Initialize AES key state here as an optimization so that
 393                  * it does not need to be initialized for every packet.
 394                  */
 395                 key->u.aes_cmac.tfm =
 396                         ieee80211_aes_cmac_key_setup(key_data);
 397                 if (IS_ERR(key->u.aes_cmac.tfm)) {
 398                         err = PTR_ERR(key->u.aes_cmac.tfm);
 399                         kfree(key);
 400                         return ERR_PTR(err);
 401                 }
 402                 break;
 403         default:
 404                 if (cs) {
 405                         size_t len = (seq_len > MAX_PN_LEN) ?
 406                                                 MAX_PN_LEN : seq_len;
 407
 408                         key->conf.iv_len = cs->hdr_len;
 409                         key->conf.icv_len = cs->mic_len;
 410                         for (i = 0; i < IEEE80211_NUM_TIDS + 1; i++)
 411                                 for (j = 0; j < len; j++)
 412                                         key->u.gen.rx_pn[i][j] =
 413                                                         seq[len - j - 1];
 414                 }
 415         }
 416         memcpy(key->conf.key, key_data, key_len);
 417         INIT_LIST_HEAD(&key->list);
 418
 419         return key;
 420 }
 421
 422 static void ieee80211_key_free_common(struct ieee80211_key *key)
 423 {
 424         if (key->conf.cipher == WLAN_CIPHER_SUITE_CCMP)
 425                 ieee80211_aes_key_free(key->u.ccmp.tfm);
 426         if (key->conf.cipher == WLAN_CIPHER_SUITE_AES_CMAC)
 427                 ieee80211_aes_cmac_key_free(key->u.aes_cmac.tfm);
 428         kfree(key);
 429 }
 430
 431 static void __ieee80211_key_destroy(struct ieee80211_key *key,
 432                                     bool delay_tailroom)
 433 {
 434         if (key->local)
 435                 ieee80211_key_disable_hw_accel(key);
 436
 437         if (key->local) {
 438                 struct ieee80211_sub_if_data *sdata = key->sdata;
 439
 440                 ieee80211_debugfs_key_remove(key);
 441
 442                 if (delay_tailroom) {
 443                         /* see ieee80211_delayed_tailroom_dec */
 444                         sdata->crypto_tx_tailroom_pending_dec++;
 445                         schedule_delayed_work(&sdata->dec_tailroom_needed_wk,
 446                                               HZ/2);
 447                 } else {
 448                         sdata->crypto_tx_tailroom_needed_cnt--;
 449                 }
 450         }
 451
 452         ieee80211_key_free_common(key);
 453 }
 454
 455 static void ieee80211_key_destroy(struct ieee80211_key *key,
 456                                   bool delay_tailroom)
 457 {
 458         if (!key)
 459                 return;
 460
 461         /*
 462          * Synchronize so the TX path can no longer be using
 463          * this key before we free/remove it.
 464          */
 465         synchronize_net();
 466
 467         __ieee80211_key_destroy(key, delay_tailroom);
 468 }
 469
 470 void ieee80211_key_free_unused(struct ieee80211_key *key)
 471 {
 472         WARN_ON(key->sdata || key->local);
 473         ieee80211_key_free_common(key);
 474 }
 475
 476 int ieee80211_key_link(struct ieee80211_key *key,
 477                        struct ieee80211_sub_if_data *sdata,
 478                        struct sta_info *sta)
 479 {
 480         struct ieee80211_local *local = sdata->local;
 481         struct ieee80211_key *old_key;
 482         int idx, ret;
 483         bool pairwise;
 484
 485         pairwise = key->conf.flags & IEEE80211_KEY_FLAG_PAIRWISE;
 486         idx = key->conf.keyidx;
 487         key->local = sdata->local;
 488         key->sdata = sdata;
 489         key->sta = sta;
 490
 491         mutex_lock(&sdata->local->key_mtx);
 492
 493         if (sta && pairwise)
 494                 old_key = key_mtx_dereference(sdata->local, sta->ptk[idx]);
 495         else if (sta)
 496                 old_key = key_mtx_dereference(sdata->local, sta->gtk[idx]);
 497         else
 498                 old_key = key_mtx_dereference(sdata->local, sdata->keys[idx]);
 499
 500         increment_tailroom_need_count(sdata);
 501
 502         ieee80211_key_replace(sdata, sta, pairwise, old_key, key);
 503         ieee80211_key_destroy(old_key, true);
 504
 505         ieee80211_debugfs_key_add(key);
 506
 507         if (!local->wowlan) {
 508                 ret = ieee80211_key_enable_hw_accel(key);
 509                 if (ret)
 510                         ieee80211_key_free(key, true);
 511         } else {
 512                 ret = 0;
 513         }
 514
 515         mutex_unlock(&sdata->local->key_mtx);
 516
 517         return ret;
 518 }
 519
 520 void ieee80211_key_free(struct ieee80211_key *key, bool delay_tailroom)
 521 {
 522         if (!key)
 523                 return;
 524
 525         /*
 526          * Replace key with nothingness if it was ever used.
 527          */
 528         if (key->sdata)
 529                 ieee80211_key_replace(key->sdata, key->sta,
 530                                 key->conf.flags & IEEE80211_KEY_FLAG_PAIRWISE,
 531                                 key, NULL);
 532         ieee80211_key_destroy(key, delay_tailroom);
 533 }
 534
 535 void ieee80211_enable_keys(struct ieee80211_sub_if_data *sdata)
 536 {
 537         struct ieee80211_key *key;
 538
 539         ASSERT_RTNL();
 540
 541         if (WARN_ON(!ieee80211_sdata_running(sdata)))
 542                 return;
 543
 544         mutex_lock(&sdata->local->key_mtx);
 545
 546         sdata->crypto_tx_tailroom_needed_cnt = 0;
 547
 548         list_for_each_entry(key, &sdata->key_list, list) {
 549                 increment_tailroom_need_count(sdata);
 550                 ieee80211_key_enable_hw_accel(key);
 551         }
 552
 553         mutex_unlock(&sdata->local->key_mtx);
 554 }
 555
 556 void ieee80211_iter_keys(struct ieee80211_hw *hw,
 557                          struct ieee80211_vif *vif,
 558                          void (*iter)(struct ieee80211_hw *hw,
 559                                       struct ieee80211_vif *vif,
 560                                       struct ieee80211_sta *sta,
 561                                       struct ieee80211_key_conf *key,
 562                                       void *data),
 563                          void *iter_data)
 564 {
 565         struct ieee80211_local *local = hw_to_local(hw);
 566         struct ieee80211_key *key, *tmp;
 567         struct ieee80211_sub_if_data *sdata;
 568
 569         ASSERT_RTNL();
 570
 571         mutex_lock(&local->key_mtx);
 572         if (vif) {
 573                 sdata = vif_to_sdata(vif);
 574                 list_for_each_entry_safe(key, tmp, &sdata->key_list, list)
 575                         iter(hw, &sdata->vif,
 576                              key->sta ? &key->sta->sta : NULL,
 577                              &key->conf, iter_data);
 578         } else {
 579                 list_for_each_entry(sdata, &local->interfaces, list)
 580                         list_for_each_entry_safe(key, tmp,
 581                                                  &sdata->key_list, list)
 582                                 iter(hw, &sdata->vif,
 583                                      key->sta ? &key->sta->sta : NULL,
 584                                      &key->conf, iter_data);
 585         }
 586         mutex_unlock(&local->key_mtx);
 587 }
 588 EXPORT_SYMBOL(ieee80211_iter_keys);
 589
 590 static void ieee80211_free_keys_iface(struct ieee80211_sub_if_data *sdata,
 591                                       struct list_head *keys)
 592 {
 593         struct ieee80211_key *key, *tmp;
 594
 595         sdata->crypto_tx_tailroom_needed_cnt -=
 596                 sdata->crypto_tx_tailroom_pending_dec;
 597         sdata->crypto_tx_tailroom_pending_dec = 0;
 598
 599         ieee80211_debugfs_key_remove_mgmt_default(sdata);
 600
 601         list_for_each_entry_safe(key, tmp, &sdata->key_list, list) {
 602                 ieee80211_key_replace(key->sdata, key->sta,
 603                                 key->conf.flags & IEEE80211_KEY_FLAG_PAIRWISE,
 604                                 key, NULL);
 605                 list_add_tail(&key->list, keys);
 606         }
 607
 608         ieee80211_debugfs_key_update_default(sdata);
 609 }
 610
 611 void ieee80211_free_keys(struct ieee80211_sub_if_data *sdata,
 612                          bool force_synchronize)
 613 {
 614         struct ieee80211_local *local = sdata->local;
 615         struct ieee80211_sub_if_data *vlan;
 616         struct ieee80211_key *key, *tmp;
 617         LIST_HEAD(keys);
 618
 619         cancel_delayed_work_sync(&sdata->dec_tailroom_needed_wk);
 620
 621         mutex_lock(&local->key_mtx);
 622
 623         ieee80211_free_keys_iface(sdata, &keys);
 624
 625         if (sdata->vif.type == NL80211_IFTYPE_AP) {
 626                 list_for_each_entry(vlan, &sdata->u.ap.vlans, u.vlan.list)
 627                         ieee80211_free_keys_iface(vlan, &keys);
 628         }
 629
 630         if (!list_empty(&keys) || force_synchronize)
 631                 synchronize_net();
 632         list_for_each_entry_safe(key, tmp, &keys, list)
 633                 __ieee80211_key_destroy(key, false);
 634
 635         WARN_ON_ONCE(sdata->crypto_tx_tailroom_needed_cnt ||
 636                      sdata->crypto_tx_tailroom_pending_dec);
 637         if (sdata->vif.type == NL80211_IFTYPE_AP) {
 638                 list_for_each_entry(vlan, &sdata->u.ap.vlans, u.vlan.list)
 639                         WARN_ON_ONCE(vlan->crypto_tx_tailroom_needed_cnt ||
 640                                      vlan->crypto_tx_tailroom_pending_dec);
 641         }
 642
 643         mutex_unlock(&local->key_mtx);
 644 }
 645
 646 void ieee80211_free_sta_keys(struct ieee80211_local *local,
 647                              struct sta_info *sta)
 648 {
 649         struct ieee80211_key *key;
 650         int i;
 651
 652         mutex_lock(&local->key_mtx);
 653         for (i = 0; i < NUM_DEFAULT_KEYS; i++) {
 654                 key = key_mtx_dereference(local, sta->gtk[i]);
 655                 if (!key)
 656                         continue;
 657                 ieee80211_key_replace(key->sdata, key->sta,
 658                                 key->conf.flags & IEEE80211_KEY_FLAG_PAIRWISE,
 659                                 key, NULL);
 660                 __ieee80211_key_destroy(key, true);
 661         }
 662
 663         for (i = 0; i < NUM_DEFAULT_KEYS; i++) {
 664                 key = key_mtx_dereference(local, sta->ptk[i]);
 665                 if (!key)
 666                         continue;
 667                 ieee80211_key_replace(key->sdata, key->sta,
 668                                 key->conf.flags & IEEE80211_KEY_FLAG_PAIRWISE,
 669                                 key, NULL);
 670                 __ieee80211_key_destroy(key, true);
 671         }
 672
 673         mutex_unlock(&local->key_mtx);
 674 }
 675
 676 void ieee80211_delayed_tailroom_dec(struct work_struct *wk)
 677 {
 678         struct ieee80211_sub_if_data *sdata;
 679
 680         sdata = container_of(wk, struct ieee80211_sub_if_data,
 681                              dec_tailroom_needed_wk.work);
 682
 683         /*
 684          * The reason for the delayed tailroom needed decrementing is to
 685          * make roaming faster: during roaming, all keys are first deleted
 686          * and then new keys are installed. The first new key causes the
 687          * crypto_tx_tailroom_needed_cnt to go from 0 to 1, which invokes
 688          * the cost of synchronize_net() (which can be slow). Avoid this
 689          * by deferring the crypto_tx_tailroom_needed_cnt decrementing on
 690          * key removal for a while, so if we roam the value is larger than
 691          * zero and no 0->1 transition happens.
 692          *
 693          * The cost is that if the AP switching was from an AP with keys
 694          * to one without, we still allocate tailroom while it would no
 695          * longer be needed. However, in the typical (fast) roaming case
 696          * within an ESS this usually won't happen.
 697          */
 698
 699         mutex_lock(&sdata->local->key_mtx);
 700         sdata->crypto_tx_tailroom_needed_cnt -=
 701                 sdata->crypto_tx_tailroom_pending_dec;
 702         sdata->crypto_tx_tailroom_pending_dec = 0;
 703         mutex_unlock(&sdata->local->key_mtx);
 704 }
 705
 706 void ieee80211_gtk_rekey_notify(struct ieee80211_vif *vif, const u8 *bssid,
 707                                 const u8 *replay_ctr, gfp_t gfp)
 708 {
 709         struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
 710
 711         trace_api_gtk_rekey_notify(sdata, bssid, replay_ctr);
 712
 713         cfg80211_gtk_rekey_notify(sdata->dev, bssid, replay_ctr, gfp);
 714 }
 715 EXPORT_SYMBOL_GPL(ieee80211_gtk_rekey_notify);
 716
 717 void ieee80211_get_key_tx_seq(struct ieee80211_key_conf *keyconf,
 718                               struct ieee80211_key_seq *seq)
 719 {
 720         struct ieee80211_key *key;
 721         u64 pn64;
 722
 723         if (WARN_ON(!(keyconf->flags & IEEE80211_KEY_FLAG_GENERATE_IV)))
 724                 return;
 725
 726         key = container_of(keyconf, struct ieee80211_key, conf);
 727
 728         switch (key->conf.cipher) {
 729         case WLAN_CIPHER_SUITE_TKIP:
 730                 seq->tkip.iv32 = key->u.tkip.tx.iv32;
 731                 seq->tkip.iv16 = key->u.tkip.tx.iv16;
 732                 break;
 733         case WLAN_CIPHER_SUITE_CCMP:
 734                 pn64 = atomic64_read(&key->u.ccmp.tx_pn);
 735                 seq->ccmp.pn[5] = pn64;
 736                 seq->ccmp.pn[4] = pn64 >> 8;
 737                 seq->ccmp.pn[3] = pn64 >> 16;
 738                 seq->ccmp.pn[2] = pn64 >> 24;
 739                 seq->ccmp.pn[1] = pn64 >> 32;
 740                 seq->ccmp.pn[0] = pn64 >> 40;
 741                 break;
 742         case WLAN_CIPHER_SUITE_AES_CMAC:
 743                 pn64 = atomic64_read(&key->u.aes_cmac.tx_pn);
 744                 seq->ccmp.pn[5] = pn64;
 745                 seq->ccmp.pn[4] = pn64 >> 8;
 746                 seq->ccmp.pn[3] = pn64 >> 16;
 747                 seq->ccmp.pn[2] = pn64 >> 24;
 748                 seq->ccmp.pn[1] = pn64 >> 32;
 749                 seq->ccmp.pn[0] = pn64 >> 40;
 750                 break;
 751         default:
 752                 WARN_ON(1);
 753         }
 754 }
 755 EXPORT_SYMBOL(ieee80211_get_key_tx_seq);
 756
 757 void ieee80211_get_key_rx_seq(struct ieee80211_key_conf *keyconf,
 758                               int tid, struct ieee80211_key_seq *seq)
 759 {
 760         struct ieee80211_key *key;
 761         const u8 *pn;
 762
 763         key = container_of(keyconf, struct ieee80211_key, conf);
 764
 765         switch (key->conf.cipher) {
 766         case WLAN_CIPHER_SUITE_TKIP:
 767                 if (WARN_ON(tid < 0 || tid >= IEEE80211_NUM_TIDS))
 768                         return;
 769                 seq->tkip.iv32 = key->u.tkip.rx[tid].iv32;
 770                 seq->tkip.iv16 = key->u.tkip.rx[tid].iv16;
 771                 break;
 772         case WLAN_CIPHER_SUITE_CCMP:
 773                 if (WARN_ON(tid < -1 || tid >= IEEE80211_NUM_TIDS))
 774                         return;
 775                 if (tid < 0)
 776                         pn = key->u.ccmp.rx_pn[IEEE80211_NUM_TIDS];
 777                 else
 778                         pn = key->u.ccmp.rx_pn[tid];
 779                 memcpy(seq->ccmp.pn, pn, IEEE80211_CCMP_PN_LEN);
 780                 break;
 781         case WLAN_CIPHER_SUITE_AES_CMAC:
 782                 if (WARN_ON(tid != 0))
 783                         return;
 784                 pn = key->u.aes_cmac.rx_pn;
 785                 memcpy(seq->aes_cmac.pn, pn, IEEE80211_CMAC_PN_LEN);
 786                 break;
 787         }
 788 }
 789 EXPORT_SYMBOL(ieee80211_get_key_rx_seq);
 790
 791 void ieee80211_set_key_tx_seq(struct ieee80211_key_conf *keyconf,
 792                               struct ieee80211_key_seq *seq)
 793 {
 794         struct ieee80211_key *key;
 795         u64 pn64;
 796
 797         key = container_of(keyconf, struct ieee80211_key, conf);
 798
 799         switch (key->conf.cipher) {
 800         case WLAN_CIPHER_SUITE_TKIP:
 801                 key->u.tkip.tx.iv32 = seq->tkip.iv32;
 802                 key->u.tkip.tx.iv16 = seq->tkip.iv16;
 803                 break;
 804         case WLAN_CIPHER_SUITE_CCMP:
 805                 pn64 = (u64)seq->ccmp.pn[5] |
 806                        ((u64)seq->ccmp.pn[4] << 8) |
 807                        ((u64)seq->ccmp.pn[3] << 16) |
 808                        ((u64)seq->ccmp.pn[2] << 24) |
 809                        ((u64)seq->ccmp.pn[1] << 32) |
 810                        ((u64)seq->ccmp.pn[0] << 40);
 811                 atomic64_set(&key->u.ccmp.tx_pn, pn64);
 812                 break;
 813         case WLAN_CIPHER_SUITE_AES_CMAC:
 814                 pn64 = (u64)seq->aes_cmac.pn[5] |
 815                        ((u64)seq->aes_cmac.pn[4] << 8) |
 816                        ((u64)seq->aes_cmac.pn[3] << 16) |
 817                        ((u64)seq->aes_cmac.pn[2] << 24) |
 818                        ((u64)seq->aes_cmac.pn[1] << 32) |
 819                        ((u64)seq->aes_cmac.pn[0] << 40);
 820                 atomic64_set(&key->u.aes_cmac.tx_pn, pn64);
 821                 break;
 822         default:
 823                 WARN_ON(1);
 824                 break;
 825         }
 826 }
 827 EXPORT_SYMBOL_GPL(ieee80211_set_key_tx_seq);
 828
 829 void ieee80211_set_key_rx_seq(struct ieee80211_key_conf *keyconf,
 830                               int tid, struct ieee80211_key_seq *seq)
 831 {
 832         struct ieee80211_key *key;
 833         u8 *pn;
 834
 835         key = container_of(keyconf, struct ieee80211_key, conf);
 836
 837         switch (key->conf.cipher) {
 838         case WLAN_CIPHER_SUITE_TKIP:
 839                 if (WARN_ON(tid < 0 || tid >= IEEE80211_NUM_TIDS))
 840                         return;
 841                 key->u.tkip.rx[tid].iv32 = seq->tkip.iv32;
 842                 key->u.tkip.rx[tid].iv16 = seq->tkip.iv16;
 843                 break;
 844         case WLAN_CIPHER_SUITE_CCMP:
 845                 if (WARN_ON(tid < -1 || tid >= IEEE80211_NUM_TIDS))
 846                         return;
 847                 if (tid < 0)
 848                         pn = key->u.ccmp.rx_pn[IEEE80211_NUM_TIDS];
 849                 else
 850                         pn = key->u.ccmp.rx_pn[tid];
 851                 memcpy(pn, seq->ccmp.pn, IEEE80211_CCMP_PN_LEN);
 852                 break;
 853         case WLAN_CIPHER_SUITE_AES_CMAC:
 854                 if (WARN_ON(tid != 0))
 855                         return;
 856                 pn = key->u.aes_cmac.rx_pn;
 857                 memcpy(pn, seq->aes_cmac.pn, IEEE80211_CMAC_PN_LEN);
 858                 break;
 859         default:
 860                 WARN_ON(1);
 861                 break;
 862         }
 863 }
 864 EXPORT_SYMBOL_GPL(ieee80211_set_key_rx_seq);
 865
 866 void ieee80211_remove_key(struct ieee80211_key_conf *keyconf)
 867 {
 868         struct ieee80211_key *key;
 869
 870         key = container_of(keyconf, struct ieee80211_key, conf);
 871
 872         assert_key_lock(key->local);
 873
 874         /*
 875          * if key was uploaded, we assume the driver will/has remove(d)
 876          * it, so adjust bookkeeping accordingly
 877          */
 878         if (key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE) {
 879                 key->flags &= ~KEY_FLAG_UPLOADED_TO_HARDWARE;
 880
 881                 if (!((key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_MMIC) ||
 882                       (key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_IV) ||
 883                       (key->conf.flags & IEEE80211_KEY_FLAG_PUT_IV_SPACE)))
 884                         increment_tailroom_need_count(key->sdata);
 885         }
 886
 887         ieee80211_key_free(key, false);
 888 }
 889 EXPORT_SYMBOL_GPL(ieee80211_remove_key);
 890
 891 struct ieee80211_key_conf *
 892 ieee80211_gtk_rekey_add(struct ieee80211_vif *vif,
 893                         struct ieee80211_key_conf *keyconf)
 894 {
 895         struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
 896         struct ieee80211_local *local = sdata->local;
 897         struct ieee80211_key *key;
 898         int err;
 899
 900         if (WARN_ON(!local->wowlan))
 901                 return ERR_PTR(-EINVAL);
 902
 903         if (WARN_ON(vif->type != NL80211_IFTYPE_STATION))
 904                 return ERR_PTR(-EINVAL);
 905
 906         key = ieee80211_key_alloc(keyconf->cipher, keyconf->keyidx,
 907                                   keyconf->keylen, keyconf->key,
 908                                   0, NULL, NULL);
 909         if (IS_ERR(key))
 910                 return ERR_CAST(key);
 911
 912         if (sdata->u.mgd.mfp != IEEE80211_MFP_DISABLED)
 913                 key->conf.flags |= IEEE80211_KEY_FLAG_RX_MGMT;
 914
 915         err = ieee80211_key_link(key, sdata, NULL);
 916         if (err)
 917                 return ERR_PTR(err);
 918
 919         return &key->conf;
 920 }
 921 EXPORT_SYMBOL_GPL(ieee80211_gtk_rekey_add);