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/iw_handler.h> 15 16#include <net/mac80211.h> 17#include "ieee80211_common.h" 18#include "ieee80211_i.h" 19#include "michael.h" 20#include "tkip.h" 21#include "aes_ccm.h" 22#include "wpa.h" 23 24static int ieee80211_get_hdr_info(const struct sk_buff *skb, u8 **sa, u8 **da, 25 u8 *qos_tid, u8 **data, size_t *data_len) 26{ 27 struct ieee80211_hdr *hdr; 28 size_t hdrlen; 29 u16 fc; 30 int a4_included; 31 u8 *pos; 32 33 hdr = (struct ieee80211_hdr *) skb->data; 34 fc = le16_to_cpu(hdr->frame_control); 35 36 hdrlen = 24; 37 if ((fc & (IEEE80211_FCTL_FROMDS | IEEE80211_FCTL_TODS)) == 38 (IEEE80211_FCTL_FROMDS | IEEE80211_FCTL_TODS)) { 39 hdrlen += ETH_ALEN; 40 *sa = hdr->addr4; 41 *da = hdr->addr3; 42 } else if (fc & IEEE80211_FCTL_FROMDS) { 43 *sa = hdr->addr3; 44 *da = hdr->addr1; 45 } else if (fc & IEEE80211_FCTL_TODS) { 46 *sa = hdr->addr2; 47 *da = hdr->addr3; 48 } else { 49 *sa = hdr->addr2; 50 *da = hdr->addr1; 51 } 52 53 if (fc & 0x80) 54 hdrlen += 2; 55 56 *data = skb->data + hdrlen; 57 *data_len = skb->len - hdrlen; 58 59 a4_included = (fc & (IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS)) == 60 (IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS); 61 if ((fc & IEEE80211_FCTL_FTYPE) == IEEE80211_FTYPE_DATA && 62 fc & IEEE80211_STYPE_QOS_DATA) { 63 pos = (u8 *) &hdr->addr4; 64 if (a4_included) 65 pos += 6; 66 *qos_tid = pos[0] & 0x0f; 67 *qos_tid |= 0x80; /* qos_included flag */ 68 } else 69 *qos_tid = 0; 70 71 return skb->len < hdrlen ? -1 : 0; 72} 73 74 75ieee80211_txrx_result 76ieee80211_tx_h_michael_mic_add(struct ieee80211_txrx_data *tx) 77{ 78 u8 *data, *sa, *da, *key, *mic, qos_tid; 79 size_t data_len; 80 u16 fc; 81 struct sk_buff *skb = tx->skb; 82 int authenticator; 83 int wpa_test = 0; 84 85 fc = tx->fc; 86 87 if (!tx->key || tx->key->alg != ALG_TKIP || skb->len < 24 || 88 !WLAN_FC_DATA_PRESENT(fc)) 89 return TXRX_CONTINUE; 90 91 if (ieee80211_get_hdr_info(skb, &sa, &da, &qos_tid, &data, &data_len)) 92 return TXRX_DROP; 93 94 if (!tx->key->force_sw_encrypt && 95 !tx->fragmented && 96 !(tx->local->hw.flags & IEEE80211_HW_TKIP_INCLUDE_MMIC) && 97 !wpa_test) { 98 /* hwaccel - with no need for preallocated room for Michael MIC 99 */ 100 return TXRX_CONTINUE; 101 } 102 103 if (skb_tailroom(skb) < MICHAEL_MIC_LEN) { 104 I802_DEBUG_INC(tx->local->tx_expand_skb_head); 105 if (unlikely(pskb_expand_head(skb, TKIP_IV_LEN, 106 MICHAEL_MIC_LEN + TKIP_ICV_LEN, 107 GFP_ATOMIC))) { 108 printk(KERN_DEBUG "%s: failed to allocate more memory " 109 "for Michael MIC\n", tx->dev->name); 110 return TXRX_DROP; 111 } 112 } 113 114 authenticator = 1; 115 key = &tx->key->key[authenticator ? ALG_TKIP_TEMP_AUTH_TX_MIC_KEY : 116 ALG_TKIP_TEMP_AUTH_RX_MIC_KEY]; 117 mic = skb_put(skb, MICHAEL_MIC_LEN); 118 michael_mic(key, da, sa, qos_tid & 0x0f, data, data_len, mic); 119 120 return TXRX_CONTINUE; 121} 122 123 124ieee80211_txrx_result 125ieee80211_rx_h_michael_mic_verify(struct ieee80211_txrx_data *rx) 126{ 127 u8 *data, *sa, *da, *key = NULL, qos_tid; 128 size_t data_len; 129 u16 fc; 130 u8 mic[MICHAEL_MIC_LEN]; 131 struct sk_buff *skb = rx->skb; 132 int authenticator = 1, wpa_test = 0; 133 134 fc = rx->fc; 135 136 /* If device handles decryption totally, skip this check */ 137 if ((rx->local->hw.flags & IEEE80211_HW_DEVICE_HIDES_WEP) || 138 (rx->local->hw.flags & IEEE80211_HW_DEVICE_STRIPS_MIC)) 139 return TXRX_CONTINUE; 140 141 if (!rx->key || rx->key->alg != ALG_TKIP || 142 !(rx->fc & IEEE80211_FCTL_PROTECTED) || !WLAN_FC_DATA_PRESENT(fc)) 143 return TXRX_CONTINUE; 144 145 if ((rx->u.rx.status->flag & RX_FLAG_DECRYPTED) && 146 !rx->key->force_sw_encrypt) { 147 if (rx->local->hw.flags & IEEE80211_HW_WEP_INCLUDE_IV) { 148 if (skb->len < MICHAEL_MIC_LEN) 149 return TXRX_DROP; 150 } 151 /* Need to verify Michael MIC sometimes in software even when 152 * hwaccel is used. Atheros ar5212: fragmented frames and QoS 153 * frames. */ 154 if (!rx->fragmented && !wpa_test) 155 goto remove_mic; 156 } 157 158 if (ieee80211_get_hdr_info(skb, &sa, &da, &qos_tid, &data, &data_len) 159 || data_len < MICHAEL_MIC_LEN) 160 return TXRX_DROP; 161 162 data_len -= MICHAEL_MIC_LEN; 163 164 authenticator = 1; 165 key = &rx->key->key[authenticator ? ALG_TKIP_TEMP_AUTH_RX_MIC_KEY : 166 ALG_TKIP_TEMP_AUTH_TX_MIC_KEY]; 167 michael_mic(key, da, sa, qos_tid & 0x0f, data, data_len, mic); 168 if (memcmp(mic, data + data_len, MICHAEL_MIC_LEN) != 0 || wpa_test) { 169 if (!rx->u.rx.ra_match) 170 return TXRX_DROP; 171 172 printk(KERN_DEBUG "%s: invalid Michael MIC in data frame from " 173 MAC_FMT "\n", rx->dev->name, MAC_ARG(sa)); 174 175 do { 176 struct ieee80211_hdr *hdr; 177 union iwreq_data wrqu; 178 char *buf = kmalloc(128, GFP_ATOMIC); 179 if (!buf) 180 break; 181 182 /* TODO: needed parameters: count, key type, TSC */ 183 hdr = (struct ieee80211_hdr *) skb->data; 184 sprintf(buf, "MLME-MICHAELMICFAILURE.indication(" 185 "keyid=%d %scast addr=" MAC_FMT ")", 186 rx->key->keyidx, 187 hdr->addr1[0] & 0x01 ? "broad" : "uni", 188 MAC_ARG(hdr->addr2)); 189 memset(&wrqu, 0, sizeof(wrqu)); 190 wrqu.data.length = strlen(buf); 191 wireless_send_event(rx->dev, IWEVCUSTOM, &wrqu, buf); 192 kfree(buf); 193 } while (0); 194 195 if (!rx->local->apdev) 196 return TXRX_DROP; 197 198 ieee80211_rx_mgmt(rx->local, rx->skb, rx->u.rx.status, 199 ieee80211_msg_michael_mic_failure); 200 201 return TXRX_QUEUED; 202 } 203 204 remove_mic: 205 /* remove Michael MIC from payload */ 206 skb_trim(skb, skb->len - MICHAEL_MIC_LEN); 207 208 return TXRX_CONTINUE; 209} 210 211 212static int tkip_encrypt_skb(struct ieee80211_txrx_data *tx, 213 struct sk_buff *skb, int test) 214{ 215 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data; 216 struct ieee80211_key *key = tx->key; 217 int hdrlen, len, tailneed; 218 u16 fc; 219 u8 *pos; 220 221 fc = le16_to_cpu(hdr->frame_control); 222 hdrlen = ieee80211_get_hdrlen(fc); 223 len = skb->len - hdrlen; 224 225 tailneed = !tx->key->force_sw_encrypt ? 0 : TKIP_ICV_LEN; 226 if ((skb_headroom(skb) < TKIP_IV_LEN || 227 skb_tailroom(skb) < tailneed)) { 228 I802_DEBUG_INC(tx->local->tx_expand_skb_head); 229 if (unlikely(pskb_expand_head(skb, TKIP_IV_LEN, tailneed, 230 GFP_ATOMIC))) 231 return -1; 232 } 233 234 pos = skb_push(skb, TKIP_IV_LEN); 235 memmove(pos, pos + TKIP_IV_LEN, hdrlen); 236 pos += hdrlen; 237 238 /* Increase IV for the frame */ 239 key->u.tkip.iv16++; 240 if (key->u.tkip.iv16 == 0) 241 key->u.tkip.iv32++; 242 243 if (!tx->key->force_sw_encrypt) { 244 u32 flags = tx->local->hw.flags; 245 hdr = (struct ieee80211_hdr *)skb->data; 246 247 /* hwaccel - with preallocated room for IV */ 248 ieee80211_tkip_add_iv(pos, key, 249 (u8) (key->u.tkip.iv16 >> 8), 250 (u8) (((key->u.tkip.iv16 >> 8) | 0x20) & 251 0x7f), 252 (u8) key->u.tkip.iv16); 253 254 if (flags & IEEE80211_HW_TKIP_REQ_PHASE2_KEY) 255 ieee80211_tkip_gen_rc4key(key, hdr->addr2, 256 tx->u.tx.control->tkip_key); 257 else if (flags & IEEE80211_HW_TKIP_REQ_PHASE1_KEY) { 258 if (key->u.tkip.iv16 == 0 || 259 !key->u.tkip.tx_initialized) { 260 ieee80211_tkip_gen_phase1key(key, hdr->addr2, 261 (u16 *)tx->u.tx.control->tkip_key); 262 key->u.tkip.tx_initialized = 1; 263 tx->u.tx.control->flags |= 264 IEEE80211_TXCTL_TKIP_NEW_PHASE1_KEY; 265 } else 266 tx->u.tx.control->flags &= 267 ~IEEE80211_TXCTL_TKIP_NEW_PHASE1_KEY; 268 } 269 270 tx->u.tx.control->key_idx = tx->key->hw_key_idx; 271 return 0; 272 } 273 274 /* Add room for ICV */ 275 skb_put(skb, TKIP_ICV_LEN); 276 277 hdr = (struct ieee80211_hdr *) skb->data; 278 ieee80211_tkip_encrypt_data(tx->local->wep_tx_tfm, 279 key, pos, len, hdr->addr2); 280 return 0; 281} 282 283 284ieee80211_txrx_result 285ieee80211_tx_h_tkip_encrypt(struct ieee80211_txrx_data *tx) 286{ 287 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) tx->skb->data; 288 u16 fc; 289 struct ieee80211_key *key = tx->key; 290 struct sk_buff *skb = tx->skb; 291 int wpa_test = 0, test = 0; 292 293 fc = le16_to_cpu(hdr->frame_control); 294 295 if (!key || key->alg != ALG_TKIP || !WLAN_FC_DATA_PRESENT(fc)) 296 return TXRX_CONTINUE; 297 298 tx->u.tx.control->icv_len = TKIP_ICV_LEN; 299 tx->u.tx.control->iv_len = TKIP_IV_LEN; 300 ieee80211_tx_set_iswep(tx); 301 302 if (!tx->key->force_sw_encrypt && 303 !(tx->local->hw.flags & IEEE80211_HW_WEP_INCLUDE_IV) && 304 !wpa_test) { 305 /* hwaccel - with no need for preallocated room for IV/ICV */ 306 tx->u.tx.control->key_idx = tx->key->hw_key_idx; 307 return TXRX_CONTINUE; 308 } 309 310 if (tkip_encrypt_skb(tx, skb, test) < 0) 311 return TXRX_DROP; 312 313 if (tx->u.tx.extra_frag) { 314 int i; 315 for (i = 0; i < tx->u.tx.num_extra_frag; i++) { 316 if (tkip_encrypt_skb(tx, tx->u.tx.extra_frag[i], test) 317 < 0) 318 return TXRX_DROP; 319 } 320 } 321 322 return TXRX_CONTINUE; 323} 324 325 326ieee80211_txrx_result 327ieee80211_rx_h_tkip_decrypt(struct ieee80211_txrx_data *rx) 328{ 329 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) rx->skb->data; 330 u16 fc; 331 int hdrlen, res, hwaccel = 0, wpa_test = 0; 332 struct ieee80211_key *key = rx->key; 333 struct sk_buff *skb = rx->skb; 334 335 fc = le16_to_cpu(hdr->frame_control); 336 hdrlen = ieee80211_get_hdrlen(fc); 337 338 if (!rx->key || rx->key->alg != ALG_TKIP || 339 !(rx->fc & IEEE80211_FCTL_PROTECTED) || 340 (rx->fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_DATA) 341 return TXRX_CONTINUE; 342 343 if (!rx->sta || skb->len - hdrlen < 12) 344 return TXRX_DROP; 345 346 if ((rx->u.rx.status->flag & RX_FLAG_DECRYPTED) && 347 !rx->key->force_sw_encrypt) { 348 if (!(rx->local->hw.flags & IEEE80211_HW_WEP_INCLUDE_IV)) { 349 /* Hardware takes care of all processing, including 350 * replay protection, so no need to continue here. */ 351 return TXRX_CONTINUE; 352 } 353 354 /* let TKIP code verify IV, but skip decryption */ 355 hwaccel = 1; 356 } 357 358 res = ieee80211_tkip_decrypt_data(rx->local->wep_rx_tfm, 359 key, skb->data + hdrlen, 360 skb->len - hdrlen, rx->sta->addr, 361 hwaccel, rx->u.rx.queue); 362 if (res != TKIP_DECRYPT_OK || wpa_test) { 363 printk(KERN_DEBUG "%s: TKIP decrypt failed for RX frame from " 364 MAC_FMT " (res=%d)\n", 365 rx->dev->name, MAC_ARG(rx->sta->addr), res); 366 return TXRX_DROP; 367 } 368 369 /* Trim ICV */ 370 skb_trim(skb, skb->len - TKIP_ICV_LEN); 371 372 /* Remove IV */ 373 memmove(skb->data + TKIP_IV_LEN, skb->data, hdrlen); 374 skb_pull(skb, TKIP_IV_LEN); 375 376 return TXRX_CONTINUE; 377} 378 379 380static void ccmp_special_blocks(struct sk_buff *skb, u8 *pn, u8 *b_0, u8 *aad, 381 int encrypted) 382{ 383 u16 fc; 384 int a4_included, qos_included; 385 u8 qos_tid, *fc_pos, *data, *sa, *da; 386 int len_a; 387 size_t data_len; 388 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data; 389 390 fc_pos = (u8 *) &hdr->frame_control; 391 fc = fc_pos[0] ^ (fc_pos[1] << 8); 392 a4_included = (fc & (IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS)) == 393 (IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS); 394 395 ieee80211_get_hdr_info(skb, &sa, &da, &qos_tid, &data, &data_len); 396 data_len -= CCMP_HDR_LEN + (encrypted ? CCMP_MIC_LEN : 0); 397 if (qos_tid & 0x80) { 398 qos_included = 1; 399 qos_tid &= 0x0f; 400 } else 401 qos_included = 0; 402 /* First block, b_0 */ 403 404 b_0[0] = 0x59; /* flags: Adata: 1, M: 011, L: 001 */ 405 /* Nonce: QoS Priority | A2 | PN */ 406 b_0[1] = qos_tid; 407 memcpy(&b_0[2], hdr->addr2, 6); 408 memcpy(&b_0[8], pn, CCMP_PN_LEN); 409 /* l(m) */ 410 b_0[14] = (data_len >> 8) & 0xff; 411 b_0[15] = data_len & 0xff; 412 413 414 /* AAD (extra authenticate-only data) / masked 802.11 header 415 * FC | A1 | A2 | A3 | SC | [A4] | [QC] */ 416 417 len_a = a4_included ? 28 : 22; 418 if (qos_included) 419 len_a += 2; 420 421 aad[0] = 0; /* (len_a >> 8) & 0xff; */ 422 aad[1] = len_a & 0xff; 423 /* Mask FC: zero subtype b4 b5 b6 */ 424 aad[2] = fc_pos[0] & ~(BIT(4) | BIT(5) | BIT(6)); 425 /* Retry, PwrMgt, MoreData; set Protected */ 426 aad[3] = (fc_pos[1] & ~(BIT(3) | BIT(4) | BIT(5))) | BIT(6); 427 memcpy(&aad[4], &hdr->addr1, 18); 428 429 /* Mask Seq#, leave Frag# */ 430 aad[22] = *((u8 *) &hdr->seq_ctrl) & 0x0f; 431 aad[23] = 0; 432 if (a4_included) { 433 memcpy(&aad[24], hdr->addr4, 6); 434 aad[30] = 0; 435 aad[31] = 0; 436 } else 437 memset(&aad[24], 0, 8); 438 if (qos_included) { 439 u8 *dpos = &aad[a4_included ? 30 : 24]; 440 441 /* Mask QoS Control field */ 442 dpos[0] = qos_tid; 443 dpos[1] = 0; 444 } 445} 446 447 448static inline void ccmp_pn2hdr(u8 *hdr, u8 *pn, int key_id) 449{ 450 hdr[0] = pn[5]; 451 hdr[1] = pn[4]; 452 hdr[2] = 0; 453 hdr[3] = 0x20 | (key_id << 6); 454 hdr[4] = pn[3]; 455 hdr[5] = pn[2]; 456 hdr[6] = pn[1]; 457 hdr[7] = pn[0]; 458} 459 460 461static inline int ccmp_hdr2pn(u8 *pn, u8 *hdr) 462{ 463 pn[0] = hdr[7]; 464 pn[1] = hdr[6]; 465 pn[2] = hdr[5]; 466 pn[3] = hdr[4]; 467 pn[4] = hdr[1]; 468 pn[5] = hdr[0]; 469 return (hdr[3] >> 6) & 0x03; 470} 471 472 473static int ccmp_encrypt_skb(struct ieee80211_txrx_data *tx, 474 struct sk_buff *skb, int test) 475{ 476 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data; 477 struct ieee80211_key *key = tx->key; 478 int hdrlen, len, tailneed; 479 u16 fc; 480 u8 *pos, *pn, *b_0, *aad, *scratch; 481 int i; 482 483 scratch = key->u.ccmp.tx_crypto_buf; 484 b_0 = scratch + 3 * AES_BLOCK_LEN; 485 aad = scratch + 4 * AES_BLOCK_LEN; 486 487 fc = le16_to_cpu(hdr->frame_control); 488 hdrlen = ieee80211_get_hdrlen(fc); 489 len = skb->len - hdrlen; 490 491 tailneed = !key->force_sw_encrypt ? 0 : CCMP_MIC_LEN; 492 493 if ((skb_headroom(skb) < CCMP_HDR_LEN || 494 skb_tailroom(skb) < tailneed)) { 495 I802_DEBUG_INC(tx->local->tx_expand_skb_head); 496 if (unlikely(pskb_expand_head(skb, CCMP_HDR_LEN, tailneed, 497 GFP_ATOMIC))) 498 return -1; 499 } 500 501 pos = skb_push(skb, CCMP_HDR_LEN); 502 memmove(pos, pos + CCMP_HDR_LEN, hdrlen); 503 hdr = (struct ieee80211_hdr *) pos; 504 pos += hdrlen; 505 506 /* PN = PN + 1 */ 507 pn = key->u.ccmp.tx_pn; 508 509 for (i = CCMP_PN_LEN - 1; i >= 0; i--) { 510 pn[i]++; 511 if (pn[i]) 512 break; 513 } 514 515 ccmp_pn2hdr(pos, pn, key->keyidx); 516 517 if (!key->force_sw_encrypt) { 518 /* hwaccel - with preallocated room for CCMP header */ 519 tx->u.tx.control->key_idx = key->hw_key_idx; 520 return 0; 521 } 522 523 pos += CCMP_HDR_LEN; 524 ccmp_special_blocks(skb, pn, b_0, aad, 0); 525 ieee80211_aes_ccm_encrypt(key->u.ccmp.tfm, scratch, b_0, aad, pos, len, 526 pos, skb_put(skb, CCMP_MIC_LEN)); 527 528 return 0; 529} 530 531 532ieee80211_txrx_result 533ieee80211_tx_h_ccmp_encrypt(struct ieee80211_txrx_data *tx) 534{ 535 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) tx->skb->data; 536 struct ieee80211_key *key = tx->key; 537 u16 fc; 538 struct sk_buff *skb = tx->skb; 539 int test = 0; 540 541 fc = le16_to_cpu(hdr->frame_control); 542 543 if (!key || key->alg != ALG_CCMP || !WLAN_FC_DATA_PRESENT(fc)) 544 return TXRX_CONTINUE; 545 546 tx->u.tx.control->icv_len = CCMP_MIC_LEN; 547 tx->u.tx.control->iv_len = CCMP_HDR_LEN; 548 ieee80211_tx_set_iswep(tx); 549 550 if (!tx->key->force_sw_encrypt && 551 !(tx->local->hw.flags & IEEE80211_HW_WEP_INCLUDE_IV)) { 552 /* hwaccel - with no need for preallocated room for CCMP " 553 * header or MIC fields */ 554 tx->u.tx.control->key_idx = tx->key->hw_key_idx; 555 return TXRX_CONTINUE; 556 } 557 558 if (ccmp_encrypt_skb(tx, skb, test) < 0) 559 return TXRX_DROP; 560 561 if (tx->u.tx.extra_frag) { 562 int i; 563 564 for (i = 0; i < tx->u.tx.num_extra_frag; i++) { 565 if (ccmp_encrypt_skb(tx, tx->u.tx.extra_frag[i], test) 566 < 0) 567 return TXRX_DROP; 568 } 569 } 570 571 return TXRX_CONTINUE; 572} 573 574 575ieee80211_txrx_result 576ieee80211_rx_h_ccmp_decrypt(struct ieee80211_txrx_data *rx) 577{ 578 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) rx->skb->data; 579 u16 fc; 580 int hdrlen; 581 struct ieee80211_key *key = rx->key; 582 struct sk_buff *skb = rx->skb; 583 u8 pn[CCMP_PN_LEN]; 584 int data_len; 585 586 fc = le16_to_cpu(hdr->frame_control); 587 hdrlen = ieee80211_get_hdrlen(fc); 588 589 if (!key || key->alg != ALG_CCMP || 590 !(rx->fc & IEEE80211_FCTL_PROTECTED) || 591 (rx->fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_DATA) 592 return TXRX_CONTINUE; 593 594 data_len = skb->len - hdrlen - CCMP_HDR_LEN - CCMP_MIC_LEN; 595 if (!rx->sta || data_len < 0) 596 return TXRX_DROP; 597 598 if ((rx->u.rx.status->flag & RX_FLAG_DECRYPTED) && 599 !key->force_sw_encrypt && 600 !(rx->local->hw.flags & IEEE80211_HW_WEP_INCLUDE_IV)) 601 return TXRX_CONTINUE; 602 603 (void) ccmp_hdr2pn(pn, skb->data + hdrlen); 604 605 if (memcmp(pn, key->u.ccmp.rx_pn[rx->u.rx.queue], CCMP_PN_LEN) <= 0) { 606#ifdef CONFIG_MAC80211_DEBUG 607 u8 *ppn = key->u.ccmp.rx_pn[rx->u.rx.queue]; 608 printk(KERN_DEBUG "%s: CCMP replay detected for RX frame from " 609 MAC_FMT " (RX PN %02x%02x%02x%02x%02x%02x <= prev. PN " 610 "%02x%02x%02x%02x%02x%02x)\n", rx->dev->name, 611 MAC_ARG(rx->sta->addr), 612 pn[0], pn[1], pn[2], pn[3], pn[4], pn[5], 613 ppn[0], ppn[1], ppn[2], ppn[3], ppn[4], ppn[5]); 614#endif /* CONFIG_MAC80211_DEBUG */ 615 key->u.ccmp.replays++; 616 return TXRX_DROP; 617 } 618 619 if ((rx->u.rx.status->flag & RX_FLAG_DECRYPTED) && 620 !key->force_sw_encrypt) { 621 /* hwaccel has already decrypted frame and verified MIC */ 622 } else { 623 u8 *scratch, *b_0, *aad; 624 625 scratch = key->u.ccmp.rx_crypto_buf; 626 b_0 = scratch + 3 * AES_BLOCK_LEN; 627 aad = scratch + 4 * AES_BLOCK_LEN; 628 629 ccmp_special_blocks(skb, pn, b_0, aad, 1); 630 631 if (ieee80211_aes_ccm_decrypt( 632 key->u.ccmp.tfm, scratch, b_0, aad, 633 skb->data + hdrlen + CCMP_HDR_LEN, data_len, 634 skb->data + skb->len - CCMP_MIC_LEN, 635 skb->data + hdrlen + CCMP_HDR_LEN)) { 636 printk(KERN_DEBUG "%s: CCMP decrypt failed for RX " 637 "frame from " MAC_FMT "\n", rx->dev->name, 638 MAC_ARG(rx->sta->addr)); 639 return TXRX_DROP; 640 } 641 } 642 643 memcpy(key->u.ccmp.rx_pn[rx->u.rx.queue], pn, CCMP_PN_LEN); 644 645 /* Remove CCMP header and MIC */ 646 skb_trim(skb, skb->len - CCMP_MIC_LEN); 647 memmove(skb->data + CCMP_HDR_LEN, skb->data, hdrlen); 648 skb_pull(skb, CCMP_HDR_LEN); 649 650 return TXRX_CONTINUE; 651} 652