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_txrx_result
  74 ieee80211_tx_h_michael_mic_add(struct ieee80211_txrx_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 TXRX_CONTINUE;
  88
  89         if (ieee80211_get_hdr_info(skb, &sa, &da, &qos_tid, &data, &data_len))
  90                 return TXRX_DROP;
  91
  92         if ((tx->key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE) &&
  93             !(tx->flags & IEEE80211_TXRXD_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 TXRX_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 TXRX_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 TXRX_CONTINUE;
 123 }
 124
 125
 126 ieee80211_txrx_result
 127 ieee80211_rx_h_michael_mic_verify(struct ieee80211_txrx_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->u.rx.status->flag & RX_FLAG_MMIC_STRIPPED)
 143                 return TXRX_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 TXRX_CONTINUE;
 148
 149         if (ieee80211_get_hdr_info(skb, &sa, &da, &qos_tid, &data, &data_len)
 150             || data_len < MICHAEL_MIC_LEN)
 151                 return TXRX_DROP;
 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_TXRXD_RXRA_MATCH))
 165                         return TXRX_DROP;
 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 TXRX_DROP;
 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.iv32_rx[rx->u.rx.queue] = rx->u.rx.tkip_iv32;
 180         rx->key->u.tkip.iv16_rx[rx->u.rx.queue] = rx->u.rx.tkip_iv16;
 181
 182         return TXRX_CONTINUE;
 183 }
 184
 185
 186 static int tkip_encrypt_skb(struct ieee80211_txrx_data *tx,
 187                             struct sk_buff *skb, int test)
 188 {
 189         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
 190         struct ieee80211_key *key = tx->key;
 191         int hdrlen, len, tailneed;
 192         u16 fc;
 193         u8 *pos;
 194
 195         fc = le16_to_cpu(hdr->frame_control);
 196         hdrlen = ieee80211_get_hdrlen(fc);
 197         len = skb->len - hdrlen;
 198
 199         if (tx->key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE)
 200                 tailneed = 0;
 201         else
 202                 tailneed = TKIP_ICV_LEN;
 203
 204         if ((skb_headroom(skb) < TKIP_IV_LEN ||
 205              skb_tailroom(skb) < tailneed)) {
 206                 I802_DEBUG_INC(tx->local->tx_expand_skb_head);
 207                 if (unlikely(pskb_expand_head(skb, TKIP_IV_LEN, tailneed,
 208                                               GFP_ATOMIC)))
 209                         return -1;
 210         }
 211
 212         pos = skb_push(skb, TKIP_IV_LEN);
 213         memmove(pos, pos + TKIP_IV_LEN, hdrlen);
 214         pos += hdrlen;
 215
 216         /* Increase IV for the frame */
 217         key->u.tkip.iv16++;
 218         if (key->u.tkip.iv16 == 0)
 219                 key->u.tkip.iv32++;
 220
 221         if (tx->key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE) {
 222                 hdr = (struct ieee80211_hdr *)skb->data;
 223
 224                 /* hwaccel - with preallocated room for IV */
 225                 ieee80211_tkip_add_iv(pos, key,
 226                                       (u8) (key->u.tkip.iv16 >> 8),
 227                                       (u8) (((key->u.tkip.iv16 >> 8) | 0x20) &
 228                                             0x7f),
 229                                       (u8) key->u.tkip.iv16);
 230
 231                 tx->u.tx.control->key_idx = tx->key->conf.hw_key_idx;
 232                 return 0;
 233         }
 234
 235         /* Add room for ICV */
 236         skb_put(skb, TKIP_ICV_LEN);
 237
 238         hdr = (struct ieee80211_hdr *) skb->data;
 239         ieee80211_tkip_encrypt_data(tx->local->wep_tx_tfm,
 240                                     key, pos, len, hdr->addr2);
 241         return 0;
 242 }
 243
 244
 245 ieee80211_txrx_result
 246 ieee80211_crypto_tkip_encrypt(struct ieee80211_txrx_data *tx)
 247 {
 248         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) tx->skb->data;
 249         u16 fc;
 250         struct sk_buff *skb = tx->skb;
 251         int wpa_test = 0, test = 0;
 252
 253         fc = le16_to_cpu(hdr->frame_control);
 254
 255         if (!WLAN_FC_DATA_PRESENT(fc))
 256                 return TXRX_CONTINUE;
 257
 258         tx->u.tx.control->icv_len = TKIP_ICV_LEN;
 259         tx->u.tx.control->iv_len = TKIP_IV_LEN;
 260         ieee80211_tx_set_iswep(tx);
 261
 262         if ((tx->key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE) &&
 263             !(tx->key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_IV) &&
 264             !wpa_test) {
 265                 /* hwaccel - with no need for preallocated room for IV/ICV */
 266                 tx->u.tx.control->key_idx = tx->key->conf.hw_key_idx;
 267                 return TXRX_CONTINUE;
 268         }
 269
 270         if (tkip_encrypt_skb(tx, skb, test) < 0)
 271                 return TXRX_DROP;
 272
 273         if (tx->u.tx.extra_frag) {
 274                 int i;
 275                 for (i = 0; i < tx->u.tx.num_extra_frag; i++) {
 276                         if (tkip_encrypt_skb(tx, tx->u.tx.extra_frag[i], test)
 277                             < 0)
 278                                 return TXRX_DROP;
 279                 }
 280         }
 281
 282         return TXRX_CONTINUE;
 283 }
 284
 285
 286 ieee80211_txrx_result
 287 ieee80211_crypto_tkip_decrypt(struct ieee80211_txrx_data *rx)
 288 {
 289         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) rx->skb->data;
 290         u16 fc;
 291         int hdrlen, res, hwaccel = 0, wpa_test = 0;
 292         struct ieee80211_key *key = rx->key;
 293         struct sk_buff *skb = rx->skb;
 294         DECLARE_MAC_BUF(mac);
 295
 296         fc = le16_to_cpu(hdr->frame_control);
 297         hdrlen = ieee80211_get_hdrlen(fc);
 298
 299         if ((rx->fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_DATA)
 300                 return TXRX_CONTINUE;
 301
 302         if (!rx->sta || skb->len - hdrlen < 12)
 303                 return TXRX_DROP;
 304
 305         if (rx->u.rx.status->flag & RX_FLAG_DECRYPTED) {
 306                 if (rx->u.rx.status->flag & RX_FLAG_IV_STRIPPED) {
 307                         /*
 308                          * Hardware took care of all processing, including
 309                          * replay protection, and stripped the ICV/IV so
 310                          * we cannot do any checks here.
 311                          */
 312                         return TXRX_CONTINUE;
 313                 }
 314
 315                 /* let TKIP code verify IV, but skip decryption */
 316                 hwaccel = 1;
 317         }
 318
 319         res = ieee80211_tkip_decrypt_data(rx->local->wep_rx_tfm,
 320                                           key, skb->data + hdrlen,
 321                                           skb->len - hdrlen, rx->sta->addr,
 322                                           hwaccel, rx->u.rx.queue,
 323                                           &rx->u.rx.tkip_iv32,
 324                                           &rx->u.rx.tkip_iv16);
 325         if (res != TKIP_DECRYPT_OK || wpa_test) {
 326                 printk(KERN_DEBUG "%s: TKIP decrypt failed for RX frame from "
 327                        "%s (res=%d)\n",
 328                        rx->dev->name, print_mac(mac, rx->sta->addr), res);
 329                 return TXRX_DROP;
 330         }
 331
 332         /* Trim ICV */
 333         skb_trim(skb, skb->len - TKIP_ICV_LEN);
 334
 335         /* Remove IV */
 336         memmove(skb->data + TKIP_IV_LEN, skb->data, hdrlen);
 337         skb_pull(skb, TKIP_IV_LEN);
 338
 339         return TXRX_CONTINUE;
 340 }
 341
 342
 343 static void ccmp_special_blocks(struct sk_buff *skb, u8 *pn, u8 *b_0, u8 *aad,
 344                                 int encrypted)
 345 {
 346         u16 fc;
 347         int a4_included, qos_included;
 348         u8 qos_tid, *fc_pos, *data, *sa, *da;
 349         int len_a;
 350         size_t data_len;
 351         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
 352
 353         fc_pos = (u8 *) &hdr->frame_control;
 354         fc = fc_pos[0] ^ (fc_pos[1] << 8);
 355         a4_included = (fc & (IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS)) ==
 356                 (IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS);
 357
 358         ieee80211_get_hdr_info(skb, &sa, &da, &qos_tid, &data, &data_len);
 359         data_len -= CCMP_HDR_LEN + (encrypted ? CCMP_MIC_LEN : 0);
 360         if (qos_tid & 0x80) {
 361                 qos_included = 1;
 362                 qos_tid &= 0x0f;
 363         } else
 364                 qos_included = 0;
 365         /* First block, b_0 */
 366
 367         b_0[0] = 0x59; /* flags: Adata: 1, M: 011, L: 001 */
 368         /* Nonce: QoS Priority | A2 | PN */
 369         b_0[1] = qos_tid;
 370         memcpy(&b_0[2], hdr->addr2, 6);
 371         memcpy(&b_0[8], pn, CCMP_PN_LEN);
 372         /* l(m) */
 373         b_0[14] = (data_len >> 8) & 0xff;
 374         b_0[15] = data_len & 0xff;
 375
 376
 377         /* AAD (extra authenticate-only data) / masked 802.11 header
 378          * FC | A1 | A2 | A3 | SC | [A4] | [QC] */
 379
 380         len_a = a4_included ? 28 : 22;
 381         if (qos_included)
 382                 len_a += 2;
 383
 384         aad[0] = 0; /* (len_a >> 8) & 0xff; */
 385         aad[1] = len_a & 0xff;
 386         /* Mask FC: zero subtype b4 b5 b6 */
 387         aad[2] = fc_pos[0] & ~(BIT(4) | BIT(5) | BIT(6));
 388         /* Retry, PwrMgt, MoreData; set Protected */
 389         aad[3] = (fc_pos[1] & ~(BIT(3) | BIT(4) | BIT(5))) | BIT(6);
 390         memcpy(&aad[4], &hdr->addr1, 18);
 391
 392         /* Mask Seq#, leave Frag# */
 393         aad[22] = *((u8 *) &hdr->seq_ctrl) & 0x0f;
 394         aad[23] = 0;
 395         if (a4_included) {
 396                 memcpy(&aad[24], hdr->addr4, 6);
 397                 aad[30] = 0;
 398                 aad[31] = 0;
 399         } else
 400                 memset(&aad[24], 0, 8);
 401         if (qos_included) {
 402                 u8 *dpos = &aad[a4_included ? 30 : 24];
 403
 404                 /* Mask QoS Control field */
 405                 dpos[0] = qos_tid;
 406                 dpos[1] = 0;
 407         }
 408 }
 409
 410
 411 static inline void ccmp_pn2hdr(u8 *hdr, u8 *pn, int key_id)
 412 {
 413         hdr[0] = pn[5];
 414         hdr[1] = pn[4];
 415         hdr[2] = 0;
 416         hdr[3] = 0x20 | (key_id << 6);
 417         hdr[4] = pn[3];
 418         hdr[5] = pn[2];
 419         hdr[6] = pn[1];
 420         hdr[7] = pn[0];
 421 }
 422
 423
 424 static inline int ccmp_hdr2pn(u8 *pn, u8 *hdr)
 425 {
 426         pn[0] = hdr[7];
 427         pn[1] = hdr[6];
 428         pn[2] = hdr[5];
 429         pn[3] = hdr[4];
 430         pn[4] = hdr[1];
 431         pn[5] = hdr[0];
 432         return (hdr[3] >> 6) & 0x03;
 433 }
 434
 435
 436 static int ccmp_encrypt_skb(struct ieee80211_txrx_data *tx,
 437                             struct sk_buff *skb, int test)
 438 {
 439         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
 440         struct ieee80211_key *key = tx->key;
 441         int hdrlen, len, tailneed;
 442         u16 fc;
 443         u8 *pos, *pn, *b_0, *aad, *scratch;
 444         int i;
 445
 446         scratch = key->u.ccmp.tx_crypto_buf;
 447         b_0 = scratch + 3 * AES_BLOCK_LEN;
 448         aad = scratch + 4 * AES_BLOCK_LEN;
 449
 450         fc = le16_to_cpu(hdr->frame_control);
 451         hdrlen = ieee80211_get_hdrlen(fc);
 452         len = skb->len - hdrlen;
 453
 454         if (key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE)
 455                 tailneed = 0;
 456         else
 457                 tailneed = CCMP_MIC_LEN;
 458
 459         if ((skb_headroom(skb) < CCMP_HDR_LEN ||
 460              skb_tailroom(skb) < tailneed)) {
 461                 I802_DEBUG_INC(tx->local->tx_expand_skb_head);
 462                 if (unlikely(pskb_expand_head(skb, CCMP_HDR_LEN, tailneed,
 463                                               GFP_ATOMIC)))
 464                         return -1;
 465         }
 466
 467         pos = skb_push(skb, CCMP_HDR_LEN);
 468         memmove(pos, pos + CCMP_HDR_LEN, hdrlen);
 469         hdr = (struct ieee80211_hdr *) pos;
 470         pos += hdrlen;
 471
 472         /* PN = PN + 1 */
 473         pn = key->u.ccmp.tx_pn;
 474
 475         for (i = CCMP_PN_LEN - 1; i >= 0; i--) {
 476                 pn[i]++;
 477                 if (pn[i])
 478                         break;
 479         }
 480
 481         ccmp_pn2hdr(pos, pn, key->conf.keyidx);
 482
 483         if (key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE) {
 484                 /* hwaccel - with preallocated room for CCMP header */
 485                 tx->u.tx.control->key_idx = key->conf.hw_key_idx;
 486                 return 0;
 487         }
 488
 489         pos += CCMP_HDR_LEN;
 490         ccmp_special_blocks(skb, pn, b_0, aad, 0);
 491         ieee80211_aes_ccm_encrypt(key->u.ccmp.tfm, scratch, b_0, aad, pos, len,
 492                                   pos, skb_put(skb, CCMP_MIC_LEN));
 493
 494         return 0;
 495 }
 496
 497
 498 ieee80211_txrx_result
 499 ieee80211_crypto_ccmp_encrypt(struct ieee80211_txrx_data *tx)
 500 {
 501         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) tx->skb->data;
 502         u16 fc;
 503         struct sk_buff *skb = tx->skb;
 504         int test = 0;
 505
 506         fc = le16_to_cpu(hdr->frame_control);
 507
 508         if (!WLAN_FC_DATA_PRESENT(fc))
 509                 return TXRX_CONTINUE;
 510
 511         tx->u.tx.control->icv_len = CCMP_MIC_LEN;
 512         tx->u.tx.control->iv_len = CCMP_HDR_LEN;
 513         ieee80211_tx_set_iswep(tx);
 514
 515         if ((tx->key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE) &&
 516             !(tx->key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_IV)) {
 517                 /* hwaccel - with no need for preallocated room for CCMP "
 518                  * header or MIC fields */
 519                 tx->u.tx.control->key_idx = tx->key->conf.hw_key_idx;
 520                 return TXRX_CONTINUE;
 521         }
 522
 523         if (ccmp_encrypt_skb(tx, skb, test) < 0)
 524                 return TXRX_DROP;
 525
 526         if (tx->u.tx.extra_frag) {
 527                 int i;
 528                 for (i = 0; i < tx->u.tx.num_extra_frag; i++) {
 529                         if (ccmp_encrypt_skb(tx, tx->u.tx.extra_frag[i], test)
 530                             < 0)
 531                                 return TXRX_DROP;
 532                 }
 533         }
 534
 535         return TXRX_CONTINUE;
 536 }
 537
 538
 539 ieee80211_txrx_result
 540 ieee80211_crypto_ccmp_decrypt(struct ieee80211_txrx_data *rx)
 541 {
 542         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) rx->skb->data;
 543         u16 fc;
 544         int hdrlen;
 545         struct ieee80211_key *key = rx->key;
 546         struct sk_buff *skb = rx->skb;
 547         u8 pn[CCMP_PN_LEN];
 548         int data_len;
 549         DECLARE_MAC_BUF(mac);
 550
 551         fc = le16_to_cpu(hdr->frame_control);
 552         hdrlen = ieee80211_get_hdrlen(fc);
 553
 554         if ((rx->fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_DATA)
 555                 return TXRX_CONTINUE;
 556
 557         data_len = skb->len - hdrlen - CCMP_HDR_LEN - CCMP_MIC_LEN;
 558         if (!rx->sta || data_len < 0)
 559                 return TXRX_DROP;
 560
 561         if ((rx->u.rx.status->flag & RX_FLAG_DECRYPTED) &&
 562             (rx->u.rx.status->flag & RX_FLAG_IV_STRIPPED))
 563                 return TXRX_CONTINUE;
 564
 565         (void) ccmp_hdr2pn(pn, skb->data + hdrlen);
 566
 567         if (memcmp(pn, key->u.ccmp.rx_pn[rx->u.rx.queue], CCMP_PN_LEN) <= 0) {
 568 #ifdef CONFIG_MAC80211_DEBUG
 569                 u8 *ppn = key->u.ccmp.rx_pn[rx->u.rx.queue];
 570
 571                 printk(KERN_DEBUG "%s: CCMP replay detected for RX frame from "
 572                        "%s (RX PN %02x%02x%02x%02x%02x%02x <= prev. PN "
 573                        "%02x%02x%02x%02x%02x%02x)\n", rx->dev->name,
 574                        print_mac(mac, rx->sta->addr),
 575                        pn[0], pn[1], pn[2], pn[3], pn[4], pn[5],
 576                        ppn[0], ppn[1], ppn[2], ppn[3], ppn[4], ppn[5]);
 577 #endif /* CONFIG_MAC80211_DEBUG */
 578                 key->u.ccmp.replays++;
 579                 return TXRX_DROP;
 580         }
 581
 582         if (!(rx->u.rx.status->flag & RX_FLAG_DECRYPTED)) {
 583                 /* hardware didn't decrypt/verify MIC */
 584                 u8 *scratch, *b_0, *aad;
 585
 586                 scratch = key->u.ccmp.rx_crypto_buf;
 587                 b_0 = scratch + 3 * AES_BLOCK_LEN;
 588                 aad = scratch + 4 * AES_BLOCK_LEN;
 589
 590                 ccmp_special_blocks(skb, pn, b_0, aad, 1);
 591
 592                 if (ieee80211_aes_ccm_decrypt(
 593                             key->u.ccmp.tfm, scratch, b_0, aad,
 594                             skb->data + hdrlen + CCMP_HDR_LEN, data_len,
 595                             skb->data + skb->len - CCMP_MIC_LEN,
 596                             skb->data + hdrlen + CCMP_HDR_LEN)) {
 597                         printk(KERN_DEBUG "%s: CCMP decrypt failed for RX "
 598                                "frame from %s\n", rx->dev->name,
 599                                print_mac(mac, rx->sta->addr));
 600                         return TXRX_DROP;
 601                 }
 602         }
 603
 604         memcpy(key->u.ccmp.rx_pn[rx->u.rx.queue], pn, CCMP_PN_LEN);
 605
 606         /* Remove CCMP header and MIC */
 607         skb_trim(skb, skb->len - CCMP_MIC_LEN);
 608         memmove(skb->data + CCMP_HDR_LEN, skb->data, hdrlen);
 609         skb_pull(skb, CCMP_HDR_LEN);
 610
 611         return TXRX_CONTINUE;
 612 }