net/mac80211/wpa.c

   1 /*
   2  * Copyright 2002-2004, Instant802 Networks, Inc.
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License version 2 as
   6  * published by the Free Software Foundation.
   7  */
   8
   9 #include <linux/netdevice.h>
  10 #include <linux/types.h>
  11 #include <linux/slab.h>
  12 #include <linux/skbuff.h>
  13 #include <linux/compiler.h>
  14 #include <net/mac80211.h>
  15
  16 #include "ieee80211_i.h"
  17 #include "michael.h"
  18 #include "tkip.h"
  19 #include "aes_ccm.h"
  20 #include "wpa.h"
  21
  22 static int ieee80211_get_hdr_info(const struct sk_buff *skb, u8 **sa, u8 **da,
  23                                   u8 *qos_tid, u8 **data, size_t *data_len)
  24 {
  25         struct ieee80211_hdr *hdr;
  26         size_t hdrlen;
  27         u16 fc;
  28         int a4_included;
  29         u8 *pos;
  30
  31         hdr = (struct ieee80211_hdr *) skb->data;
  32         fc = le16_to_cpu(hdr->frame_control);
  33
  34         hdrlen = 24;
  35         if ((fc & (IEEE80211_FCTL_FROMDS | IEEE80211_FCTL_TODS)) ==
  36             (IEEE80211_FCTL_FROMDS | IEEE80211_FCTL_TODS)) {
  37                 hdrlen += ETH_ALEN;
  38                 *sa = hdr->addr4;
  39                 *da = hdr->addr3;
  40         } else if (fc & IEEE80211_FCTL_FROMDS) {
  41                 *sa = hdr->addr3;
  42                 *da = hdr->addr1;
  43         } else if (fc & IEEE80211_FCTL_TODS) {
  44                 *sa = hdr->addr2;
  45                 *da = hdr->addr3;
  46         } else {
  47                 *sa = hdr->addr2;
  48                 *da = hdr->addr1;
  49         }
  50
  51         if (fc & 0x80)
  52                 hdrlen += 2;
  53
  54         *data = skb->data + hdrlen;
  55         *data_len = skb->len - hdrlen;
  56
  57         a4_included = (fc & (IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS)) ==
  58                 (IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS);
  59         if ((fc & IEEE80211_FCTL_FTYPE) == IEEE80211_FTYPE_DATA &&
  60             fc & IEEE80211_STYPE_QOS_DATA) {
  61                 pos = (u8 *) &hdr->addr4;
  62                 if (a4_included)
  63                         pos += 6;
  64                 *qos_tid = pos[0] & 0x0f;
  65                 *qos_tid |= 0x80; /* qos_included flag */
  66         } else
  67                 *qos_tid = 0;
  68
  69         return skb->len < hdrlen ? -1 : 0;
  70 }
  71
  72
  73 ieee80211_tx_result
  74 ieee80211_tx_h_michael_mic_add(struct ieee80211_tx_data *tx)
  75 {
  76         u8 *data, *sa, *da, *key, *mic, qos_tid;
  77         size_t data_len;
  78         u16 fc;
  79         struct sk_buff *skb = tx->skb;
  80         int authenticator;
  81         int wpa_test = 0;
  82
  83         fc = tx->fc;
  84
  85         if (!tx->key || tx->key->conf.alg != ALG_TKIP || skb->len < 24 ||
  86             !WLAN_FC_DATA_PRESENT(fc))
  87                 return TX_CONTINUE;
  88
  89         if (ieee80211_get_hdr_info(skb, &sa, &da, &qos_tid, &data, &data_len))
  90                 return TX_DROP;
  91
  92         if ((tx->key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE) &&
  93             !(tx->flags & IEEE80211_TX_FRAGMENTED) &&
  94             !(tx->key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_MMIC) &&
  95             !wpa_test) {
  96                 /* hwaccel - with no need for preallocated room for Michael MIC
  97                  */
  98                 return TX_CONTINUE;
  99         }
 100
 101         if (skb_tailroom(skb) < MICHAEL_MIC_LEN) {
 102                 I802_DEBUG_INC(tx->local->tx_expand_skb_head);
 103                 if (unlikely(pskb_expand_head(skb, TKIP_IV_LEN,
 104                                               MICHAEL_MIC_LEN + TKIP_ICV_LEN,
 105                                               GFP_ATOMIC))) {
 106                         printk(KERN_DEBUG "%s: failed to allocate more memory "
 107                                "for Michael MIC\n", tx->dev->name);
 108                         return TX_DROP;
 109                 }
 110         }
 111
 112 #if 0
 113         authenticator = fc & IEEE80211_FCTL_FROMDS; /* FIX */
 114 #else
 115         authenticator = 1;
 116 #endif
 117         key = &tx->key->conf.key[authenticator ? ALG_TKIP_TEMP_AUTH_TX_MIC_KEY :
 118                                  ALG_TKIP_TEMP_AUTH_RX_MIC_KEY];
 119         mic = skb_put(skb, MICHAEL_MIC_LEN);
 120         michael_mic(key, da, sa, qos_tid & 0x0f, data, data_len, mic);
 121
 122         return TX_CONTINUE;
 123 }
 124
 125
 126 ieee80211_rx_result
 127 ieee80211_rx_h_michael_mic_verify(struct ieee80211_rx_data *rx)
 128 {
 129         u8 *data, *sa, *da, *key = NULL, qos_tid;
 130         size_t data_len;
 131         u16 fc;
 132         u8 mic[MICHAEL_MIC_LEN];
 133         struct sk_buff *skb = rx->skb;
 134         int authenticator = 1, wpa_test = 0;
 135         DECLARE_MAC_BUF(mac);
 136
 137         fc = rx->fc;
 138
 139         /*
 140          * No way to verify the MIC if the hardware stripped it
 141          */
 142         if (rx->status->flag & RX_FLAG_MMIC_STRIPPED)
 143                 return RX_CONTINUE;
 144
 145         if (!rx->key || rx->key->conf.alg != ALG_TKIP ||
 146             !(rx->fc & IEEE80211_FCTL_PROTECTED) || !WLAN_FC_DATA_PRESENT(fc))
 147                 return RX_CONTINUE;
 148
 149         if (ieee80211_get_hdr_info(skb, &sa, &da, &qos_tid, &data, &data_len)
 150             || data_len < MICHAEL_MIC_LEN)
 151                 return RX_DROP_UNUSABLE;
 152
 153         data_len -= MICHAEL_MIC_LEN;
 154
 155 #if 0
 156         authenticator = fc & IEEE80211_FCTL_TODS; /* FIX */
 157 #else
 158         authenticator = 1;
 159 #endif
 160         key = &rx->key->conf.key[authenticator ? ALG_TKIP_TEMP_AUTH_RX_MIC_KEY :
 161                                  ALG_TKIP_TEMP_AUTH_TX_MIC_KEY];
 162         michael_mic(key, da, sa, qos_tid & 0x0f, data, data_len, mic);
 163         if (memcmp(mic, data + data_len, MICHAEL_MIC_LEN) != 0 || wpa_test) {
 164                 if (!(rx->flags & IEEE80211_RX_RA_MATCH))
 165                         return RX_DROP_UNUSABLE;
 166
 167                 printk(KERN_DEBUG "%s: invalid Michael MIC in data frame from "
 168                        "%s\n", rx->dev->name, print_mac(mac, sa));
 169
 170                 mac80211_ev_michael_mic_failure(rx->dev, rx->key->conf.keyidx,
 171                                                 (void *) skb->data);
 172                 return RX_DROP_UNUSABLE;
 173         }
 174
 175         /* remove Michael MIC from payload */
 176         skb_trim(skb, skb->len - MICHAEL_MIC_LEN);
 177
 178         /* update IV in key information to be able to detect replays */
 179         rx->key->u.tkip.rx[rx->queue].iv32 = rx->tkip_iv32;
 180         rx->key->u.tkip.rx[rx->queue].iv16 = rx->tkip_iv16;
 181
 182         return RX_CONTINUE;
 183 }
 184
 185
 186 static int tkip_encrypt_skb(struct ieee80211_tx_data *tx, struct sk_buff *skb)
 187 {
 188         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
 189         struct ieee80211_key *key = tx->key;
 190         struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
 191         int hdrlen, len, tailneed;
 192         u16 fc;
 193         u8 *pos;
 194
 195         info->control.icv_len = TKIP_ICV_LEN;
 196         info->control.iv_len = TKIP_IV_LEN;
 197
 198         if ((tx->key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE) &&
 199             !(tx->key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_IV)) {
 200                 /* hwaccel - with no need for preallocated room for IV/ICV */
 201                 info->control.hw_key = &tx->key->conf;
 202                 return TX_CONTINUE;
 203         }
 204
 205         fc = le16_to_cpu(hdr->frame_control);
 206         hdrlen = ieee80211_get_hdrlen(fc);
 207         len = skb->len - hdrlen;
 208
 209         if (tx->key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE)
 210                 tailneed = 0;
 211         else
 212                 tailneed = TKIP_ICV_LEN;
 213
 214         if ((skb_headroom(skb) < TKIP_IV_LEN ||
 215              skb_tailroom(skb) < tailneed)) {
 216                 I802_DEBUG_INC(tx->local->tx_expand_skb_head);
 217                 if (unlikely(pskb_expand_head(skb, TKIP_IV_LEN, tailneed,
 218                                               GFP_ATOMIC)))
 219                         return -1;
 220         }
 221
 222         pos = skb_push(skb, TKIP_IV_LEN);
 223         memmove(pos, pos + TKIP_IV_LEN, hdrlen);
 224         pos += hdrlen;
 225
 226         /* Increase IV for the frame */
 227         key->u.tkip.tx.iv16++;
 228         if (key->u.tkip.tx.iv16 == 0)
 229                 key->u.tkip.tx.iv32++;
 230
 231         if (tx->key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE) {
 232                 hdr = (struct ieee80211_hdr *)skb->data;
 233
 234                 /* hwaccel - with preallocated room for IV */
 235                 ieee80211_tkip_add_iv(pos, key,
 236                                       (u8) (key->u.tkip.tx.iv16 >> 8),
 237                                       (u8) (((key->u.tkip.tx.iv16 >> 8) | 0x20) &
 238                                             0x7f),
 239                                       (u8) key->u.tkip.tx.iv16);
 240
 241                 info->control.hw_key = &tx->key->conf;
 242                 return 0;
 243         }
 244
 245         /* Add room for ICV */
 246         skb_put(skb, TKIP_ICV_LEN);
 247
 248         hdr = (struct ieee80211_hdr *) skb->data;
 249         ieee80211_tkip_encrypt_data(tx->local->wep_tx_tfm,
 250                                     key, pos, len, hdr->addr2);
 251         return 0;
 252 }
 253
 254
 255 ieee80211_tx_result
 256 ieee80211_crypto_tkip_encrypt(struct ieee80211_tx_data *tx)
 257 {
 258         struct sk_buff *skb = tx->skb;
 259
 260         ieee80211_tx_set_protected(tx);
 261
 262         if (tkip_encrypt_skb(tx, skb) < 0)
 263                 return TX_DROP;
 264
 265         if (tx->extra_frag) {
 266                 int i;
 267                 for (i = 0; i < tx->num_extra_frag; i++) {
 268                         if (tkip_encrypt_skb(tx, tx->extra_frag[i]) < 0)
 269                                 return TX_DROP;
 270                 }
 271         }
 272
 273         return TX_CONTINUE;
 274 }
 275
 276
 277 ieee80211_rx_result
 278 ieee80211_crypto_tkip_decrypt(struct ieee80211_rx_data *rx)
 279 {
 280         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) rx->skb->data;
 281         u16 fc;
 282         int hdrlen, res, hwaccel = 0, wpa_test = 0;
 283         struct ieee80211_key *key = rx->key;
 284         struct sk_buff *skb = rx->skb;
 285         DECLARE_MAC_BUF(mac);
 286
 287         fc = le16_to_cpu(hdr->frame_control);
 288         hdrlen = ieee80211_get_hdrlen(fc);
 289
 290         if ((rx->fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_DATA)
 291                 return RX_CONTINUE;
 292
 293         if (!rx->sta || skb->len - hdrlen < 12)
 294                 return RX_DROP_UNUSABLE;
 295
 296         if (rx->status->flag & RX_FLAG_DECRYPTED) {
 297                 if (rx->status->flag & RX_FLAG_IV_STRIPPED) {
 298                         /*
 299                          * Hardware took care of all processing, including
 300                          * replay protection, and stripped the ICV/IV so
 301                          * we cannot do any checks here.
 302                          */
 303                         return RX_CONTINUE;
 304                 }
 305
 306                 /* let TKIP code verify IV, but skip decryption */
 307                 hwaccel = 1;
 308         }
 309
 310         res = ieee80211_tkip_decrypt_data(rx->local->wep_rx_tfm,
 311                                           key, skb->data + hdrlen,
 312                                           skb->len - hdrlen, rx->sta->addr,
 313                                           hdr->addr1, hwaccel, rx->queue,
 314                                           &rx->tkip_iv32,
 315                                           &rx->tkip_iv16);
 316         if (res != TKIP_DECRYPT_OK || wpa_test) {
 317 #ifdef CONFIG_MAC80211_DEBUG
 318                 if (net_ratelimit())
 319                         printk(KERN_DEBUG "%s: TKIP decrypt failed for RX "
 320                                "frame from %s (res=%d)\n", rx->dev->name,
 321                                print_mac(mac, rx->sta->addr), res);
 322 #endif /* CONFIG_MAC80211_DEBUG */
 323                 return RX_DROP_UNUSABLE;
 324         }
 325
 326         /* Trim ICV */
 327         skb_trim(skb, skb->len - TKIP_ICV_LEN);
 328
 329         /* Remove IV */
 330         memmove(skb->data + TKIP_IV_LEN, skb->data, hdrlen);
 331         skb_pull(skb, TKIP_IV_LEN);
 332
 333         return RX_CONTINUE;
 334 }
 335
 336
 337 static void ccmp_special_blocks(struct sk_buff *skb, u8 *pn, u8 *b_0, u8 *aad,
 338                                 int encrypted)
 339 {
 340         u16 fc;
 341         int a4_included, qos_included;
 342         u8 qos_tid, *fc_pos, *data, *sa, *da;
 343         int len_a;
 344         size_t data_len;
 345         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
 346
 347         fc_pos = (u8 *) &hdr->frame_control;
 348         fc = fc_pos[0] ^ (fc_pos[1] << 8);
 349         a4_included = (fc & (IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS)) ==
 350                 (IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS);
 351
 352         ieee80211_get_hdr_info(skb, &sa, &da, &qos_tid, &data, &data_len);
 353         data_len -= CCMP_HDR_LEN + (encrypted ? CCMP_MIC_LEN : 0);
 354         if (qos_tid & 0x80) {
 355                 qos_included = 1;
 356                 qos_tid &= 0x0f;
 357         } else
 358                 qos_included = 0;
 359         /* First block, b_0 */
 360
 361         b_0[0] = 0x59; /* flags: Adata: 1, M: 011, L: 001 */
 362         /* Nonce: QoS Priority | A2 | PN */
 363         b_0[1] = qos_tid;
 364         memcpy(&b_0[2], hdr->addr2, 6);
 365         memcpy(&b_0[8], pn, CCMP_PN_LEN);
 366         /* l(m) */
 367         b_0[14] = (data_len >> 8) & 0xff;
 368         b_0[15] = data_len & 0xff;
 369
 370
 371         /* AAD (extra authenticate-only data) / masked 802.11 header
 372          * FC | A1 | A2 | A3 | SC | [A4] | [QC] */
 373
 374         len_a = a4_included ? 28 : 22;
 375         if (qos_included)
 376                 len_a += 2;
 377
 378         aad[0] = 0; /* (len_a >> 8) & 0xff; */
 379         aad[1] = len_a & 0xff;
 380         /* Mask FC: zero subtype b4 b5 b6 */
 381         aad[2] = fc_pos[0] & ~(BIT(4) | BIT(5) | BIT(6));
 382         /* Retry, PwrMgt, MoreData; set Protected */
 383         aad[3] = (fc_pos[1] & ~(BIT(3) | BIT(4) | BIT(5))) | BIT(6);
 384         memcpy(&aad[4], &hdr->addr1, 18);
 385
 386         /* Mask Seq#, leave Frag# */
 387         aad[22] = *((u8 *) &hdr->seq_ctrl) & 0x0f;
 388         aad[23] = 0;
 389         if (a4_included) {
 390                 memcpy(&aad[24], hdr->addr4, 6);
 391                 aad[30] = 0;
 392                 aad[31] = 0;
 393         } else
 394                 memset(&aad[24], 0, 8);
 395         if (qos_included) {
 396                 u8 *dpos = &aad[a4_included ? 30 : 24];
 397
 398                 /* Mask QoS Control field */
 399                 dpos[0] = qos_tid;
 400                 dpos[1] = 0;
 401         }
 402 }
 403
 404
 405 static inline void ccmp_pn2hdr(u8 *hdr, u8 *pn, int key_id)
 406 {
 407         hdr[0] = pn[5];
 408         hdr[1] = pn[4];
 409         hdr[2] = 0;
 410         hdr[3] = 0x20 | (key_id << 6);
 411         hdr[4] = pn[3];
 412         hdr[5] = pn[2];
 413         hdr[6] = pn[1];
 414         hdr[7] = pn[0];
 415 }
 416
 417
 418 static inline int ccmp_hdr2pn(u8 *pn, u8 *hdr)
 419 {
 420         pn[0] = hdr[7];
 421         pn[1] = hdr[6];
 422         pn[2] = hdr[5];
 423         pn[3] = hdr[4];
 424         pn[4] = hdr[1];
 425         pn[5] = hdr[0];
 426         return (hdr[3] >> 6) & 0x03;
 427 }
 428
 429
 430 static int ccmp_encrypt_skb(struct ieee80211_tx_data *tx, struct sk_buff *skb)
 431 {
 432         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
 433         struct ieee80211_key *key = tx->key;
 434         struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
 435         int hdrlen, len, tailneed;
 436         u16 fc;
 437         u8 *pos, *pn, *b_0, *aad, *scratch;
 438         int i;
 439
 440         info->control.icv_len = CCMP_MIC_LEN;
 441         info->control.iv_len = CCMP_HDR_LEN;
 442
 443         if ((tx->key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE) &&
 444             !(tx->key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_IV)) {
 445                 /* hwaccel - with no need for preallocated room for CCMP "
 446                  * header or MIC fields */
 447                 info->control.hw_key = &tx->key->conf;
 448                 return TX_CONTINUE;
 449         }
 450
 451         scratch = key->u.ccmp.tx_crypto_buf;
 452         b_0 = scratch + 3 * AES_BLOCK_LEN;
 453         aad = scratch + 4 * AES_BLOCK_LEN;
 454
 455         fc = le16_to_cpu(hdr->frame_control);
 456         hdrlen = ieee80211_get_hdrlen(fc);
 457         len = skb->len - hdrlen;
 458
 459         if (key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE)
 460                 tailneed = 0;
 461         else
 462                 tailneed = CCMP_MIC_LEN;
 463
 464         if ((skb_headroom(skb) < CCMP_HDR_LEN ||
 465              skb_tailroom(skb) < tailneed)) {
 466                 I802_DEBUG_INC(tx->local->tx_expand_skb_head);
 467                 if (unlikely(pskb_expand_head(skb, CCMP_HDR_LEN, tailneed,
 468                                               GFP_ATOMIC)))
 469                         return -1;
 470         }
 471
 472         pos = skb_push(skb, CCMP_HDR_LEN);
 473         memmove(pos, pos + CCMP_HDR_LEN, hdrlen);
 474         hdr = (struct ieee80211_hdr *) pos;
 475         pos += hdrlen;
 476
 477         /* PN = PN + 1 */
 478         pn = key->u.ccmp.tx_pn;
 479
 480         for (i = CCMP_PN_LEN - 1; i >= 0; i--) {
 481                 pn[i]++;
 482                 if (pn[i])
 483                         break;
 484         }
 485
 486         ccmp_pn2hdr(pos, pn, key->conf.keyidx);
 487
 488         if (key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE) {
 489                 /* hwaccel - with preallocated room for CCMP header */
 490                 info->control.hw_key = &tx->key->conf;
 491                 return 0;
 492         }
 493
 494         pos += CCMP_HDR_LEN;
 495         ccmp_special_blocks(skb, pn, b_0, aad, 0);
 496         ieee80211_aes_ccm_encrypt(key->u.ccmp.tfm, scratch, b_0, aad, pos, len,
 497                                   pos, skb_put(skb, CCMP_MIC_LEN));
 498
 499         return 0;
 500 }
 501
 502
 503 ieee80211_tx_result
 504 ieee80211_crypto_ccmp_encrypt(struct ieee80211_tx_data *tx)
 505 {
 506         struct sk_buff *skb = tx->skb;
 507
 508         ieee80211_tx_set_protected(tx);
 509
 510         if (ccmp_encrypt_skb(tx, skb) < 0)
 511                 return TX_DROP;
 512
 513         if (tx->extra_frag) {
 514                 int i;
 515                 for (i = 0; i < tx->num_extra_frag; i++) {
 516                         if (ccmp_encrypt_skb(tx, tx->extra_frag[i]) < 0)
 517                                 return TX_DROP;
 518                 }
 519         }
 520
 521         return TX_CONTINUE;
 522 }
 523
 524
 525 ieee80211_rx_result
 526 ieee80211_crypto_ccmp_decrypt(struct ieee80211_rx_data *rx)
 527 {
 528         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) rx->skb->data;
 529         u16 fc;
 530         int hdrlen;
 531         struct ieee80211_key *key = rx->key;
 532         struct sk_buff *skb = rx->skb;
 533         u8 pn[CCMP_PN_LEN];
 534         int data_len;
 535         DECLARE_MAC_BUF(mac);
 536
 537         fc = le16_to_cpu(hdr->frame_control);
 538         hdrlen = ieee80211_get_hdrlen(fc);
 539
 540         if ((rx->fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_DATA)
 541                 return RX_CONTINUE;
 542
 543         data_len = skb->len - hdrlen - CCMP_HDR_LEN - CCMP_MIC_LEN;
 544         if (!rx->sta || data_len < 0)
 545                 return RX_DROP_UNUSABLE;
 546
 547         if ((rx->status->flag & RX_FLAG_DECRYPTED) &&
 548             (rx->status->flag & RX_FLAG_IV_STRIPPED))
 549                 return RX_CONTINUE;
 550
 551         (void) ccmp_hdr2pn(pn, skb->data + hdrlen);
 552
 553         if (memcmp(pn, key->u.ccmp.rx_pn[rx->queue], CCMP_PN_LEN) <= 0) {
 554 #ifdef CONFIG_MAC80211_DEBUG
 555                 u8 *ppn = key->u.ccmp.rx_pn[rx->queue];
 556
 557                 printk(KERN_DEBUG "%s: CCMP replay detected for RX frame from "
 558                        "%s (RX PN %02x%02x%02x%02x%02x%02x <= prev. PN "
 559                        "%02x%02x%02x%02x%02x%02x)\n", rx->dev->name,
 560                        print_mac(mac, rx->sta->addr),
 561                        pn[0], pn[1], pn[2], pn[3], pn[4], pn[5],
 562                        ppn[0], ppn[1], ppn[2], ppn[3], ppn[4], ppn[5]);
 563 #endif /* CONFIG_MAC80211_DEBUG */
 564                 key->u.ccmp.replays++;
 565                 return RX_DROP_UNUSABLE;
 566         }
 567
 568         if (!(rx->status->flag & RX_FLAG_DECRYPTED)) {
 569                 /* hardware didn't decrypt/verify MIC */
 570                 u8 *scratch, *b_0, *aad;
 571
 572                 scratch = key->u.ccmp.rx_crypto_buf;
 573                 b_0 = scratch + 3 * AES_BLOCK_LEN;
 574                 aad = scratch + 4 * AES_BLOCK_LEN;
 575
 576                 ccmp_special_blocks(skb, pn, b_0, aad, 1);
 577
 578                 if (ieee80211_aes_ccm_decrypt(
 579                             key->u.ccmp.tfm, scratch, b_0, aad,
 580                             skb->data + hdrlen + CCMP_HDR_LEN, data_len,
 581                             skb->data + skb->len - CCMP_MIC_LEN,
 582                             skb->data + hdrlen + CCMP_HDR_LEN)) {
 583 #ifdef CONFIG_MAC80211_DEBUG
 584                         if (net_ratelimit())
 585                                 printk(KERN_DEBUG "%s: CCMP decrypt failed "
 586                                        "for RX frame from %s\n", rx->dev->name,
 587                                        print_mac(mac, rx->sta->addr));
 588 #endif /* CONFIG_MAC80211_DEBUG */
 589                         return RX_DROP_UNUSABLE;
 590                 }
 591         }
 592
 593         memcpy(key->u.ccmp.rx_pn[rx->queue], pn, CCMP_PN_LEN);
 594
 595         /* Remove CCMP header and MIC */
 596         skb_trim(skb, skb->len - CCMP_MIC_LEN);
 597         memmove(skb->data + CCMP_HDR_LEN, skb->data, hdrlen);
 598         skb_pull(skb, CCMP_HDR_LEN);
 599
 600         return RX_CONTINUE;
 601 }