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 <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
 624         mutex_lock(&sdata->local->key_mtx);
 625
 626         if (sta && pairwise)
 627                 old_key = key_mtx_dereference(sdata->local, sta->ptk[idx]);
 628         else if (sta)
 629                 old_key = key_mtx_dereference(sdata->local, sta->gtk[idx]);
 630         else
 631                 old_key = key_mtx_dereference(sdata->local, sdata->keys[idx]);
 632
 633         /*
 634          * Silently accept key re-installation without really installing the
 635          * new version of the key to avoid nonce reuse or replay issues.
 636          */
 637         if (old_key && key->conf.keylen == old_key->conf.keylen &&
 638             !memcmp(key->conf.key, old_key->conf.key, key->conf.keylen)) {
 639                 ieee80211_key_free_unused(key);
 640                 ret = 0;
 641                 goto out;
 642         }
 643
 644         key->local = sdata->local;
 645         key->sdata = sdata;
 646         key->sta = sta;
 647
 648         increment_tailroom_need_count(sdata);
 649
 650         ieee80211_key_replace(sdata, sta, pairwise, old_key, key);
 651         ieee80211_key_destroy(old_key, true);
 652
 653         ieee80211_debugfs_key_add(key);
 654
 655         if (!local->wowlan) {
 656                 ret = ieee80211_key_enable_hw_accel(key);
 657                 if (ret)
 658                         ieee80211_key_free(key, true);
 659         } else {
 660                 ret = 0;
 661         }
 662
 663  out:
 664         mutex_unlock(&sdata->local->key_mtx);
 665
 666         return ret;
 667 }
 668
 669 void ieee80211_key_free(struct ieee80211_key *key, bool delay_tailroom)
 670 {
 671         if (!key)
 672                 return;
 673
 674         /*
 675          * Replace key with nothingness if it was ever used.
 676          */
 677         if (key->sdata)
 678                 ieee80211_key_replace(key->sdata, key->sta,
 679                                 key->conf.flags & IEEE80211_KEY_FLAG_PAIRWISE,
 680                                 key, NULL);
 681         ieee80211_key_destroy(key, delay_tailroom);
 682 }
 683
 684 void ieee80211_enable_keys(struct ieee80211_sub_if_data *sdata)
 685 {
 686         struct ieee80211_key *key;
 687         struct ieee80211_sub_if_data *vlan;
 688
 689         ASSERT_RTNL();
 690
 691         if (WARN_ON(!ieee80211_sdata_running(sdata)))
 692                 return;
 693
 694         mutex_lock(&sdata->local->key_mtx);
 695
 696         WARN_ON_ONCE(sdata->crypto_tx_tailroom_needed_cnt ||
 697                      sdata->crypto_tx_tailroom_pending_dec);
 698
 699         if (sdata->vif.type == NL80211_IFTYPE_AP) {
 700                 list_for_each_entry(vlan, &sdata->u.ap.vlans, u.vlan.list)
 701                         WARN_ON_ONCE(vlan->crypto_tx_tailroom_needed_cnt ||
 702                                      vlan->crypto_tx_tailroom_pending_dec);
 703         }
 704
 705         list_for_each_entry(key, &sdata->key_list, list) {
 706                 increment_tailroom_need_count(sdata);
 707                 ieee80211_key_enable_hw_accel(key);
 708         }
 709
 710         mutex_unlock(&sdata->local->key_mtx);
 711 }
 712
 713 void ieee80211_reset_crypto_tx_tailroom(struct ieee80211_sub_if_data *sdata)
 714 {
 715         struct ieee80211_sub_if_data *vlan;
 716
 717         mutex_lock(&sdata->local->key_mtx);
 718
 719         sdata->crypto_tx_tailroom_needed_cnt = 0;
 720
 721         if (sdata->vif.type == NL80211_IFTYPE_AP) {
 722                 list_for_each_entry(vlan, &sdata->u.ap.vlans, u.vlan.list)
 723                         vlan->crypto_tx_tailroom_needed_cnt = 0;
 724         }
 725
 726         mutex_unlock(&sdata->local->key_mtx);
 727 }
 728
 729 void ieee80211_iter_keys(struct ieee80211_hw *hw,
 730                          struct ieee80211_vif *vif,
 731                          void (*iter)(struct ieee80211_hw *hw,
 732                                       struct ieee80211_vif *vif,
 733                                       struct ieee80211_sta *sta,
 734                                       struct ieee80211_key_conf *key,
 735                                       void *data),
 736                          void *iter_data)
 737 {
 738         struct ieee80211_local *local = hw_to_local(hw);
 739         struct ieee80211_key *key, *tmp;
 740         struct ieee80211_sub_if_data *sdata;
 741
 742         ASSERT_RTNL();
 743
 744         mutex_lock(&local->key_mtx);
 745         if (vif) {
 746                 sdata = vif_to_sdata(vif);
 747                 list_for_each_entry_safe(key, tmp, &sdata->key_list, list)
 748                         iter(hw, &sdata->vif,
 749                              key->sta ? &key->sta->sta : NULL,
 750                              &key->conf, iter_data);
 751         } else {
 752                 list_for_each_entry(sdata, &local->interfaces, list)
 753                         list_for_each_entry_safe(key, tmp,
 754                                                  &sdata->key_list, list)
 755                                 iter(hw, &sdata->vif,
 756                                      key->sta ? &key->sta->sta : NULL,
 757                                      &key->conf, iter_data);
 758         }
 759         mutex_unlock(&local->key_mtx);
 760 }
 761 EXPORT_SYMBOL(ieee80211_iter_keys);
 762
 763 static void
 764 _ieee80211_iter_keys_rcu(struct ieee80211_hw *hw,
 765                          struct ieee80211_sub_if_data *sdata,
 766                          void (*iter)(struct ieee80211_hw *hw,
 767                                       struct ieee80211_vif *vif,
 768                                       struct ieee80211_sta *sta,
 769                                       struct ieee80211_key_conf *key,
 770                                       void *data),
 771                          void *iter_data)
 772 {
 773         struct ieee80211_key *key;
 774
 775         list_for_each_entry_rcu(key, &sdata->key_list, list) {
 776                 /* skip keys of station in removal process */
 777                 if (key->sta && key->sta->removed)
 778                         continue;
 779                 if (!(key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE))
 780                         continue;
 781
 782                 iter(hw, &sdata->vif,
 783                      key->sta ? &key->sta->sta : NULL,
 784                      &key->conf, iter_data);
 785         }
 786 }
 787
 788 void ieee80211_iter_keys_rcu(struct ieee80211_hw *hw,
 789                              struct ieee80211_vif *vif,
 790                              void (*iter)(struct ieee80211_hw *hw,
 791                                           struct ieee80211_vif *vif,
 792                                           struct ieee80211_sta *sta,
 793                                           struct ieee80211_key_conf *key,
 794                                           void *data),
 795                              void *iter_data)
 796 {
 797         struct ieee80211_local *local = hw_to_local(hw);
 798         struct ieee80211_sub_if_data *sdata;
 799
 800         if (vif) {
 801                 sdata = vif_to_sdata(vif);
 802                 _ieee80211_iter_keys_rcu(hw, sdata, iter, iter_data);
 803         } else {
 804                 list_for_each_entry_rcu(sdata, &local->interfaces, list)
 805                         _ieee80211_iter_keys_rcu(hw, sdata, iter, iter_data);
 806         }
 807 }
 808 EXPORT_SYMBOL(ieee80211_iter_keys_rcu);
 809
 810 static void ieee80211_free_keys_iface(struct ieee80211_sub_if_data *sdata,
 811                                       struct list_head *keys)
 812 {
 813         struct ieee80211_key *key, *tmp;
 814
 815         decrease_tailroom_need_count(sdata,
 816                                      sdata->crypto_tx_tailroom_pending_dec);
 817         sdata->crypto_tx_tailroom_pending_dec = 0;
 818
 819         ieee80211_debugfs_key_remove_mgmt_default(sdata);
 820
 821         list_for_each_entry_safe(key, tmp, &sdata->key_list, list) {
 822                 ieee80211_key_replace(key->sdata, key->sta,
 823                                 key->conf.flags & IEEE80211_KEY_FLAG_PAIRWISE,
 824                                 key, NULL);
 825                 list_add_tail(&key->list, keys);
 826         }
 827
 828         ieee80211_debugfs_key_update_default(sdata);
 829 }
 830
 831 void ieee80211_free_keys(struct ieee80211_sub_if_data *sdata,
 832                          bool force_synchronize)
 833 {
 834         struct ieee80211_local *local = sdata->local;
 835         struct ieee80211_sub_if_data *vlan;
 836         struct ieee80211_sub_if_data *master;
 837         struct ieee80211_key *key, *tmp;
 838         LIST_HEAD(keys);
 839
 840         cancel_delayed_work_sync(&sdata->dec_tailroom_needed_wk);
 841
 842         mutex_lock(&local->key_mtx);
 843
 844         ieee80211_free_keys_iface(sdata, &keys);
 845
 846         if (sdata->vif.type == NL80211_IFTYPE_AP) {
 847                 list_for_each_entry(vlan, &sdata->u.ap.vlans, u.vlan.list)
 848                         ieee80211_free_keys_iface(vlan, &keys);
 849         }
 850
 851         if (!list_empty(&keys) || force_synchronize)
 852                 synchronize_net();
 853         list_for_each_entry_safe(key, tmp, &keys, list)
 854                 __ieee80211_key_destroy(key, false);
 855
 856         if (sdata->vif.type == NL80211_IFTYPE_AP_VLAN) {
 857                 if (sdata->bss) {
 858                         master = container_of(sdata->bss,
 859                                               struct ieee80211_sub_if_data,
 860                                               u.ap);
 861
 862                         WARN_ON_ONCE(sdata->crypto_tx_tailroom_needed_cnt !=
 863                                      master->crypto_tx_tailroom_needed_cnt);
 864                 }
 865         } else {
 866                 WARN_ON_ONCE(sdata->crypto_tx_tailroom_needed_cnt ||
 867                              sdata->crypto_tx_tailroom_pending_dec);
 868         }
 869
 870         if (sdata->vif.type == NL80211_IFTYPE_AP) {
 871                 list_for_each_entry(vlan, &sdata->u.ap.vlans, u.vlan.list)
 872                         WARN_ON_ONCE(vlan->crypto_tx_tailroom_needed_cnt ||
 873                                      vlan->crypto_tx_tailroom_pending_dec);
 874         }
 875
 876         mutex_unlock(&local->key_mtx);
 877 }
 878
 879 void ieee80211_free_sta_keys(struct ieee80211_local *local,
 880                              struct sta_info *sta)
 881 {
 882         struct ieee80211_key *key;
 883         int i;
 884
 885         mutex_lock(&local->key_mtx);
 886         for (i = 0; i < ARRAY_SIZE(sta->gtk); i++) {
 887                 key = key_mtx_dereference(local, sta->gtk[i]);
 888                 if (!key)
 889                         continue;
 890                 ieee80211_key_replace(key->sdata, key->sta,
 891                                 key->conf.flags & IEEE80211_KEY_FLAG_PAIRWISE,
 892                                 key, NULL);
 893                 __ieee80211_key_destroy(key, true);
 894         }
 895
 896         for (i = 0; i < NUM_DEFAULT_KEYS; i++) {
 897                 key = key_mtx_dereference(local, sta->ptk[i]);
 898                 if (!key)
 899                         continue;
 900                 ieee80211_key_replace(key->sdata, key->sta,
 901                                 key->conf.flags & IEEE80211_KEY_FLAG_PAIRWISE,
 902                                 key, NULL);
 903                 __ieee80211_key_destroy(key, true);
 904         }
 905
 906         mutex_unlock(&local->key_mtx);
 907 }
 908
 909 void ieee80211_delayed_tailroom_dec(struct work_struct *wk)
 910 {
 911         struct ieee80211_sub_if_data *sdata;
 912
 913         sdata = container_of(wk, struct ieee80211_sub_if_data,
 914                              dec_tailroom_needed_wk.work);
 915
 916         /*
 917          * The reason for the delayed tailroom needed decrementing is to
 918          * make roaming faster: during roaming, all keys are first deleted
 919          * and then new keys are installed. The first new key causes the
 920          * crypto_tx_tailroom_needed_cnt to go from 0 to 1, which invokes
 921          * the cost of synchronize_net() (which can be slow). Avoid this
 922          * by deferring the crypto_tx_tailroom_needed_cnt decrementing on
 923          * key removal for a while, so if we roam the value is larger than
 924          * zero and no 0->1 transition happens.
 925          *
 926          * The cost is that if the AP switching was from an AP with keys
 927          * to one without, we still allocate tailroom while it would no
 928          * longer be needed. However, in the typical (fast) roaming case
 929          * within an ESS this usually won't happen.
 930          */
 931
 932         mutex_lock(&sdata->local->key_mtx);
 933         decrease_tailroom_need_count(sdata,
 934                                      sdata->crypto_tx_tailroom_pending_dec);
 935         sdata->crypto_tx_tailroom_pending_dec = 0;
 936         mutex_unlock(&sdata->local->key_mtx);
 937 }
 938
 939 void ieee80211_gtk_rekey_notify(struct ieee80211_vif *vif, const u8 *bssid,
 940                                 const u8 *replay_ctr, gfp_t gfp)
 941 {
 942         struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
 943
 944         trace_api_gtk_rekey_notify(sdata, bssid, replay_ctr);
 945
 946         cfg80211_gtk_rekey_notify(sdata->dev, bssid, replay_ctr, gfp);
 947 }
 948 EXPORT_SYMBOL_GPL(ieee80211_gtk_rekey_notify);
 949
 950 void ieee80211_get_key_rx_seq(struct ieee80211_key_conf *keyconf,
 951                               int tid, struct ieee80211_key_seq *seq)
 952 {
 953         struct ieee80211_key *key;
 954         const u8 *pn;
 955
 956         key = container_of(keyconf, struct ieee80211_key, conf);
 957
 958         switch (key->conf.cipher) {
 959         case WLAN_CIPHER_SUITE_TKIP:
 960                 if (WARN_ON(tid < 0 || tid >= IEEE80211_NUM_TIDS))
 961                         return;
 962                 seq->tkip.iv32 = key->u.tkip.rx[tid].iv32;
 963                 seq->tkip.iv16 = key->u.tkip.rx[tid].iv16;
 964                 break;
 965         case WLAN_CIPHER_SUITE_CCMP:
 966         case WLAN_CIPHER_SUITE_CCMP_256:
 967                 if (WARN_ON(tid < -1 || tid >= IEEE80211_NUM_TIDS))
 968                         return;
 969                 if (tid < 0)
 970                         pn = key->u.ccmp.rx_pn[IEEE80211_NUM_TIDS];
 971                 else
 972                         pn = key->u.ccmp.rx_pn[tid];
 973                 memcpy(seq->ccmp.pn, pn, IEEE80211_CCMP_PN_LEN);
 974                 break;
 975         case WLAN_CIPHER_SUITE_AES_CMAC:
 976         case WLAN_CIPHER_SUITE_BIP_CMAC_256:
 977                 if (WARN_ON(tid != 0))
 978                         return;
 979                 pn = key->u.aes_cmac.rx_pn;
 980                 memcpy(seq->aes_cmac.pn, pn, IEEE80211_CMAC_PN_LEN);
 981                 break;
 982         case WLAN_CIPHER_SUITE_BIP_GMAC_128:
 983         case WLAN_CIPHER_SUITE_BIP_GMAC_256:
 984                 if (WARN_ON(tid != 0))
 985                         return;
 986                 pn = key->u.aes_gmac.rx_pn;
 987                 memcpy(seq->aes_gmac.pn, pn, IEEE80211_GMAC_PN_LEN);
 988                 break;
 989         case WLAN_CIPHER_SUITE_GCMP:
 990         case WLAN_CIPHER_SUITE_GCMP_256:
 991                 if (WARN_ON(tid < -1 || tid >= IEEE80211_NUM_TIDS))
 992                         return;
 993                 if (tid < 0)
 994                         pn = key->u.gcmp.rx_pn[IEEE80211_NUM_TIDS];
 995                 else
 996                         pn = key->u.gcmp.rx_pn[tid];
 997                 memcpy(seq->gcmp.pn, pn, IEEE80211_GCMP_PN_LEN);
 998                 break;
 999         }
1000 }
1001 EXPORT_SYMBOL(ieee80211_get_key_rx_seq);
1002
1003 void ieee80211_set_key_rx_seq(struct ieee80211_key_conf *keyconf,
1004                               int tid, struct ieee80211_key_seq *seq)
1005 {
1006         struct ieee80211_key *key;
1007         u8 *pn;
1008
1009         key = container_of(keyconf, struct ieee80211_key, conf);
1010
1011         switch (key->conf.cipher) {
1012         case WLAN_CIPHER_SUITE_TKIP:
1013                 if (WARN_ON(tid < 0 || tid >= IEEE80211_NUM_TIDS))
1014                         return;
1015                 key->u.tkip.rx[tid].iv32 = seq->tkip.iv32;
1016                 key->u.tkip.rx[tid].iv16 = seq->tkip.iv16;
1017                 break;
1018         case WLAN_CIPHER_SUITE_CCMP:
1019         case WLAN_CIPHER_SUITE_CCMP_256:
1020                 if (WARN_ON(tid < -1 || tid >= IEEE80211_NUM_TIDS))
1021                         return;
1022                 if (tid < 0)
1023                         pn = key->u.ccmp.rx_pn[IEEE80211_NUM_TIDS];
1024                 else
1025                         pn = key->u.ccmp.rx_pn[tid];
1026                 memcpy(pn, seq->ccmp.pn, IEEE80211_CCMP_PN_LEN);
1027                 break;
1028         case WLAN_CIPHER_SUITE_AES_CMAC:
1029         case WLAN_CIPHER_SUITE_BIP_CMAC_256:
1030                 if (WARN_ON(tid != 0))
1031                         return;
1032                 pn = key->u.aes_cmac.rx_pn;
1033                 memcpy(pn, seq->aes_cmac.pn, IEEE80211_CMAC_PN_LEN);
1034                 break;
1035         case WLAN_CIPHER_SUITE_BIP_GMAC_128:
1036         case WLAN_CIPHER_SUITE_BIP_GMAC_256:
1037                 if (WARN_ON(tid != 0))
1038                         return;
1039                 pn = key->u.aes_gmac.rx_pn;
1040                 memcpy(pn, seq->aes_gmac.pn, IEEE80211_GMAC_PN_LEN);
1041                 break;
1042         case WLAN_CIPHER_SUITE_GCMP:
1043         case WLAN_CIPHER_SUITE_GCMP_256:
1044                 if (WARN_ON(tid < -1 || tid >= IEEE80211_NUM_TIDS))
1045                         return;
1046                 if (tid < 0)
1047                         pn = key->u.gcmp.rx_pn[IEEE80211_NUM_TIDS];
1048                 else
1049                         pn = key->u.gcmp.rx_pn[tid];
1050                 memcpy(pn, seq->gcmp.pn, IEEE80211_GCMP_PN_LEN);
1051                 break;
1052         default:
1053                 WARN_ON(1);
1054                 break;
1055         }
1056 }
1057 EXPORT_SYMBOL_GPL(ieee80211_set_key_rx_seq);
1058
1059 void ieee80211_remove_key(struct ieee80211_key_conf *keyconf)
1060 {
1061         struct ieee80211_key *key;
1062
1063         key = container_of(keyconf, struct ieee80211_key, conf);
1064
1065         assert_key_lock(key->local);
1066
1067         /*
1068          * if key was uploaded, we assume the driver will/has remove(d)
1069          * it, so adjust bookkeeping accordingly
1070          */
1071         if (key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE) {
1072                 key->flags &= ~KEY_FLAG_UPLOADED_TO_HARDWARE;
1073
1074                 if (!((key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_MMIC) ||
1075                       (key->conf.flags & IEEE80211_KEY_FLAG_RESERVE_TAILROOM)))
1076                         increment_tailroom_need_count(key->sdata);
1077         }
1078
1079         ieee80211_key_free(key, false);
1080 }
1081 EXPORT_SYMBOL_GPL(ieee80211_remove_key);
1082
1083 struct ieee80211_key_conf *
1084 ieee80211_gtk_rekey_add(struct ieee80211_vif *vif,
1085                         struct ieee80211_key_conf *keyconf)
1086 {
1087         struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
1088         struct ieee80211_local *local = sdata->local;
1089         struct ieee80211_key *key;
1090         int err;
1091
1092         if (WARN_ON(!local->wowlan))
1093                 return ERR_PTR(-EINVAL);
1094
1095         if (WARN_ON(vif->type != NL80211_IFTYPE_STATION))
1096                 return ERR_PTR(-EINVAL);
1097
1098         key = ieee80211_key_alloc(keyconf->cipher, keyconf->keyidx,
1099                                   keyconf->keylen, keyconf->key,
1100                                   0, NULL, NULL);
1101         if (IS_ERR(key))
1102                 return ERR_CAST(key);
1103
1104         if (sdata->u.mgd.mfp != IEEE80211_MFP_DISABLED)
1105                 key->conf.flags |= IEEE80211_KEY_FLAG_RX_MGMT;
1106
1107         err = ieee80211_key_link(key, sdata, NULL);
1108         if (err)
1109                 return ERR_PTR(err);
1110
1111         return &key->conf;
1112 }
1113 EXPORT_SYMBOL_GPL(ieee80211_gtk_rekey_add);