net/mac80211/key.c

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