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 24 static 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 75 ieee80211_txrx_result 76 ieee80211_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 #if 0 115 authenticator = fc & IEEE80211_FCTL_FROMDS; /* FIX */ 116 #else 117 authenticator = 1; 118 #endif 119 key = &tx->key->key[authenticator ? ALG_TKIP_TEMP_AUTH_TX_MIC_KEY : 120 ALG_TKIP_TEMP_AUTH_RX_MIC_KEY]; 121 mic = skb_put(skb, MICHAEL_MIC_LEN); 122 michael_mic(key, da, sa, qos_tid & 0x0f, data, data_len, mic); 123 124 return TXRX_CONTINUE; 125 } 126 127 128 ieee80211_txrx_result 129 ieee80211_rx_h_michael_mic_verify(struct ieee80211_txrx_data *rx) 130 { 131 u8 *data, *sa, *da, *key = NULL, qos_tid; 132 size_t data_len; 133 u16 fc; 134 u8 mic[MICHAEL_MIC_LEN]; 135 struct sk_buff *skb = rx->skb; 136 int authenticator = 1, wpa_test = 0; 137 138 fc = rx->fc; 139 140 /* If device handles decryption totally, skip this check */ 141 if ((rx->local->hw.flags & IEEE80211_HW_DEVICE_HIDES_WEP) || 142 (rx->local->hw.flags & IEEE80211_HW_DEVICE_STRIPS_MIC)) 143 return TXRX_CONTINUE; 144 145 if (!rx->key || rx->key->alg != ALG_TKIP || 146 !(rx->fc & IEEE80211_FCTL_PROTECTED) || !WLAN_FC_DATA_PRESENT(fc)) 147 return TXRX_CONTINUE; 148 149 if ((rx->u.rx.status->flag & RX_FLAG_DECRYPTED) && 150 !rx->key->force_sw_encrypt) { 151 if (rx->local->hw.flags & IEEE80211_HW_WEP_INCLUDE_IV) { 152 if (skb->len < MICHAEL_MIC_LEN) 153 return TXRX_DROP; 154 } 155 /* Need to verify Michael MIC sometimes in software even when 156 * hwaccel is used. Atheros ar5212: fragmented frames and QoS 157 * frames. */ 158 if (!rx->fragmented && !wpa_test) 159 goto remove_mic; 160 } 161 162 if (ieee80211_get_hdr_info(skb, &sa, &da, &qos_tid, &data, &data_len) 163 || data_len < MICHAEL_MIC_LEN) 164 return TXRX_DROP; 165 166 data_len -= MICHAEL_MIC_LEN; 167 168 #if 0 169 authenticator = fc & IEEE80211_FCTL_TODS; /* FIX */ 170 #else 171 authenticator = 1; 172 #endif 173 key = &rx->key->key[authenticator ? ALG_TKIP_TEMP_AUTH_RX_MIC_KEY : 174 ALG_TKIP_TEMP_AUTH_TX_MIC_KEY]; 175 michael_mic(key, da, sa, qos_tid & 0x0f, data, data_len, mic); 176 if (memcmp(mic, data + data_len, MICHAEL_MIC_LEN) != 0 || wpa_test) { 177 if (!rx->u.rx.ra_match) 178 return TXRX_DROP; 179 180 printk(KERN_DEBUG "%s: invalid Michael MIC in data frame from " 181 MAC_FMT "\n", rx->dev->name, MAC_ARG(sa)); 182 183 do { 184 struct ieee80211_hdr *hdr; 185 union iwreq_data wrqu; 186 char *buf = kmalloc(128, GFP_ATOMIC); 187 if (!buf) 188 break; 189 190 /* TODO: needed parameters: count, key type, TSC */ 191 hdr = (struct ieee80211_hdr *) skb->data; 192 sprintf(buf, "MLME-MICHAELMICFAILURE.indication(" 193 "keyid=%d %scast addr=" MAC_FMT ")", 194 rx->key->keyidx, 195 hdr->addr1[0] & 0x01 ? "broad" : "uni", 196 MAC_ARG(hdr->addr2)); 197 memset(&wrqu, 0, sizeof(wrqu)); 198 wrqu.data.length = strlen(buf); 199 wireless_send_event(rx->dev, IWEVCUSTOM, &wrqu, buf); 200 kfree(buf); 201 } while (0); 202 203 if (!rx->local->apdev) 204 return TXRX_DROP; 205 206 ieee80211_rx_mgmt(rx->local, rx->skb, rx->u.rx.status, 207 ieee80211_msg_michael_mic_failure); 208 209 return TXRX_QUEUED; 210 } 211 212 remove_mic: 213 /* remove Michael MIC from payload */ 214 skb_trim(skb, skb->len - MICHAEL_MIC_LEN); 215 216 return TXRX_CONTINUE; 217 } 218 219 220 static int tkip_encrypt_skb(struct ieee80211_txrx_data *tx, 221 struct sk_buff *skb, int test) 222 { 223 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data; 224 struct ieee80211_key *key = tx->key; 225 int hdrlen, len, tailneed; 226 u16 fc; 227 u8 *pos; 228 229 fc = le16_to_cpu(hdr->frame_control); 230 hdrlen = ieee80211_get_hdrlen(fc); 231 len = skb->len - hdrlen; 232 233 tailneed = !tx->key->force_sw_encrypt ? 0 : TKIP_ICV_LEN; 234 if ((skb_headroom(skb) < TKIP_IV_LEN || 235 skb_tailroom(skb) < tailneed)) { 236 I802_DEBUG_INC(tx->local->tx_expand_skb_head); 237 if (unlikely(pskb_expand_head(skb, TKIP_IV_LEN, tailneed, 238 GFP_ATOMIC))) 239 return -1; 240 } 241 242 pos = skb_push(skb, TKIP_IV_LEN); 243 memmove(pos, pos + TKIP_IV_LEN, hdrlen); 244 pos += hdrlen; 245 246 /* Increase IV for the frame */ 247 key->u.tkip.iv16++; 248 if (key->u.tkip.iv16 == 0) 249 key->u.tkip.iv32++; 250 251 if (!tx->key->force_sw_encrypt) { 252 u32 flags = tx->local->hw.flags; 253 hdr = (struct ieee80211_hdr *)skb->data; 254 255 /* hwaccel - with preallocated room for IV */ 256 ieee80211_tkip_add_iv(pos, key, 257 (u8) (key->u.tkip.iv16 >> 8), 258 (u8) (((key->u.tkip.iv16 >> 8) | 0x20) & 259 0x7f), 260 (u8) key->u.tkip.iv16); 261 262 if (flags & IEEE80211_HW_TKIP_REQ_PHASE2_KEY) 263 ieee80211_tkip_gen_rc4key(key, hdr->addr2, 264 tx->u.tx.control->tkip_key); 265 else if (flags & IEEE80211_HW_TKIP_REQ_PHASE1_KEY) { 266 if (key->u.tkip.iv16 == 0 || 267 !key->u.tkip.tx_initialized) { 268 ieee80211_tkip_gen_phase1key(key, hdr->addr2, 269 (u16 *)tx->u.tx.control->tkip_key); 270 key->u.tkip.tx_initialized = 1; 271 tx->u.tx.control->flags |= 272 IEEE80211_TXCTL_TKIP_NEW_PHASE1_KEY; 273 } else 274 tx->u.tx.control->flags &= 275 ~IEEE80211_TXCTL_TKIP_NEW_PHASE1_KEY; 276 } 277 278 tx->u.tx.control->key_idx = tx->key->hw_key_idx; 279 return 0; 280 } 281 282 /* Add room for ICV */ 283 skb_put(skb, TKIP_ICV_LEN); 284 285 hdr = (struct ieee80211_hdr *) skb->data; 286 ieee80211_tkip_encrypt_data(tx->local->wep_tx_tfm, 287 key, pos, len, hdr->addr2); 288 return 0; 289 } 290 291 292 ieee80211_txrx_result 293 ieee80211_tx_h_tkip_encrypt(struct ieee80211_txrx_data *tx) 294 { 295 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) tx->skb->data; 296 u16 fc; 297 struct ieee80211_key *key = tx->key; 298 struct sk_buff *skb = tx->skb; 299 int wpa_test = 0, test = 0; 300 301 fc = le16_to_cpu(hdr->frame_control); 302 303 if (!key || key->alg != ALG_TKIP || !WLAN_FC_DATA_PRESENT(fc)) 304 return TXRX_CONTINUE; 305 306 tx->u.tx.control->icv_len = TKIP_ICV_LEN; 307 tx->u.tx.control->iv_len = TKIP_IV_LEN; 308 ieee80211_tx_set_iswep(tx); 309 310 if (!tx->key->force_sw_encrypt && 311 !(tx->local->hw.flags & IEEE80211_HW_WEP_INCLUDE_IV) && 312 !wpa_test) { 313 /* hwaccel - with no need for preallocated room for IV/ICV */ 314 tx->u.tx.control->key_idx = tx->key->hw_key_idx; 315 return TXRX_CONTINUE; 316 } 317 318 if (tkip_encrypt_skb(tx, skb, test) < 0) 319 return TXRX_DROP; 320 321 if (tx->u.tx.extra_frag) { 322 int i; 323 for (i = 0; i < tx->u.tx.num_extra_frag; i++) { 324 if (tkip_encrypt_skb(tx, tx->u.tx.extra_frag[i], test) 325 < 0) 326 return TXRX_DROP; 327 } 328 } 329 330 return TXRX_CONTINUE; 331 } 332 333 334 ieee80211_txrx_result 335 ieee80211_rx_h_tkip_decrypt(struct ieee80211_txrx_data *rx) 336 { 337 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) rx->skb->data; 338 u16 fc; 339 int hdrlen, res, hwaccel = 0, wpa_test = 0; 340 struct ieee80211_key *key = rx->key; 341 struct sk_buff *skb = rx->skb; 342 343 fc = le16_to_cpu(hdr->frame_control); 344 hdrlen = ieee80211_get_hdrlen(fc); 345 346 if (!rx->key || rx->key->alg != ALG_TKIP || 347 !(rx->fc & IEEE80211_FCTL_PROTECTED) || 348 (rx->fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_DATA) 349 return TXRX_CONTINUE; 350 351 if (!rx->sta || skb->len - hdrlen < 12) 352 return TXRX_DROP; 353 354 if ((rx->u.rx.status->flag & RX_FLAG_DECRYPTED) && 355 !rx->key->force_sw_encrypt) { 356 if (!(rx->local->hw.flags & IEEE80211_HW_WEP_INCLUDE_IV)) { 357 /* Hardware takes care of all processing, including 358 * replay protection, so no need to continue here. */ 359 return TXRX_CONTINUE; 360 } 361 362 /* let TKIP code verify IV, but skip decryption */ 363 hwaccel = 1; 364 } 365 366 res = ieee80211_tkip_decrypt_data(rx->local->wep_rx_tfm, 367 key, skb->data + hdrlen, 368 skb->len - hdrlen, rx->sta->addr, 369 hwaccel, rx->u.rx.queue); 370 if (res != TKIP_DECRYPT_OK || wpa_test) { 371 printk(KERN_DEBUG "%s: TKIP decrypt failed for RX frame from " 372 MAC_FMT " (res=%d)\n", 373 rx->dev->name, MAC_ARG(rx->sta->addr), res); 374 return TXRX_DROP; 375 } 376 377 /* Trim ICV */ 378 skb_trim(skb, skb->len - TKIP_ICV_LEN); 379 380 /* Remove IV */ 381 memmove(skb->data + TKIP_IV_LEN, skb->data, hdrlen); 382 skb_pull(skb, TKIP_IV_LEN); 383 384 return TXRX_CONTINUE; 385 } 386 387 388 static void ccmp_special_blocks(struct sk_buff *skb, u8 *pn, u8 *b_0, u8 *aad, 389 int encrypted) 390 { 391 u16 fc; 392 int a4_included, qos_included; 393 u8 qos_tid, *fc_pos, *data, *sa, *da; 394 int len_a; 395 size_t data_len; 396 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data; 397 398 fc_pos = (u8 *) &hdr->frame_control; 399 fc = fc_pos[0] ^ (fc_pos[1] << 8); 400 a4_included = (fc & (IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS)) == 401 (IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS); 402 403 ieee80211_get_hdr_info(skb, &sa, &da, &qos_tid, &data, &data_len); 404 data_len -= CCMP_HDR_LEN + (encrypted ? CCMP_MIC_LEN : 0); 405 if (qos_tid & 0x80) { 406 qos_included = 1; 407 qos_tid &= 0x0f; 408 } else 409 qos_included = 0; 410 /* First block, b_0 */ 411 412 b_0[0] = 0x59; /* flags: Adata: 1, M: 011, L: 001 */ 413 /* Nonce: QoS Priority | A2 | PN */ 414 b_0[1] = qos_tid; 415 memcpy(&b_0[2], hdr->addr2, 6); 416 memcpy(&b_0[8], pn, CCMP_PN_LEN); 417 /* l(m) */ 418 b_0[14] = (data_len >> 8) & 0xff; 419 b_0[15] = data_len & 0xff; 420 421 422 /* AAD (extra authenticate-only data) / masked 802.11 header 423 * FC | A1 | A2 | A3 | SC | [A4] | [QC] */ 424 425 len_a = a4_included ? 28 : 22; 426 if (qos_included) 427 len_a += 2; 428 429 aad[0] = 0; /* (len_a >> 8) & 0xff; */ 430 aad[1] = len_a & 0xff; 431 /* Mask FC: zero subtype b4 b5 b6 */ 432 aad[2] = fc_pos[0] & ~(BIT(4) | BIT(5) | BIT(6)); 433 /* Retry, PwrMgt, MoreData; set Protected */ 434 aad[3] = (fc_pos[1] & ~(BIT(3) | BIT(4) | BIT(5))) | BIT(6); 435 memcpy(&aad[4], &hdr->addr1, 18); 436 437 /* Mask Seq#, leave Frag# */ 438 aad[22] = *((u8 *) &hdr->seq_ctrl) & 0x0f; 439 aad[23] = 0; 440 if (a4_included) { 441 memcpy(&aad[24], hdr->addr4, 6); 442 aad[30] = 0; 443 aad[31] = 0; 444 } else 445 memset(&aad[24], 0, 8); 446 if (qos_included) { 447 u8 *dpos = &aad[a4_included ? 30 : 24]; 448 449 /* Mask QoS Control field */ 450 dpos[0] = qos_tid; 451 dpos[1] = 0; 452 } 453 } 454 455 456 static inline void ccmp_pn2hdr(u8 *hdr, u8 *pn, int key_id) 457 { 458 hdr[0] = pn[5]; 459 hdr[1] = pn[4]; 460 hdr[2] = 0; 461 hdr[3] = 0x20 | (key_id << 6); 462 hdr[4] = pn[3]; 463 hdr[5] = pn[2]; 464 hdr[6] = pn[1]; 465 hdr[7] = pn[0]; 466 } 467 468 469 static inline int ccmp_hdr2pn(u8 *pn, u8 *hdr) 470 { 471 pn[0] = hdr[7]; 472 pn[1] = hdr[6]; 473 pn[2] = hdr[5]; 474 pn[3] = hdr[4]; 475 pn[4] = hdr[1]; 476 pn[5] = hdr[0]; 477 return (hdr[3] >> 6) & 0x03; 478 } 479 480 481 static int ccmp_encrypt_skb(struct ieee80211_txrx_data *tx, 482 struct sk_buff *skb, int test) 483 { 484 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data; 485 struct ieee80211_key *key = tx->key; 486 int hdrlen, len, tailneed; 487 u16 fc; 488 u8 *pos, *pn, *b_0, *aad, *scratch; 489 int i; 490 491 scratch = key->u.ccmp.tx_crypto_buf; 492 b_0 = scratch + 3 * AES_BLOCK_LEN; 493 aad = scratch + 4 * AES_BLOCK_LEN; 494 495 fc = le16_to_cpu(hdr->frame_control); 496 hdrlen = ieee80211_get_hdrlen(fc); 497 len = skb->len - hdrlen; 498 499 tailneed = !key->force_sw_encrypt ? 0 : CCMP_MIC_LEN; 500 501 if ((skb_headroom(skb) < CCMP_HDR_LEN || 502 skb_tailroom(skb) < tailneed)) { 503 I802_DEBUG_INC(tx->local->tx_expand_skb_head); 504 if (unlikely(pskb_expand_head(skb, CCMP_HDR_LEN, tailneed, 505 GFP_ATOMIC))) 506 return -1; 507 } 508 509 pos = skb_push(skb, CCMP_HDR_LEN); 510 memmove(pos, pos + CCMP_HDR_LEN, hdrlen); 511 hdr = (struct ieee80211_hdr *) pos; 512 pos += hdrlen; 513 514 /* PN = PN + 1 */ 515 pn = key->u.ccmp.tx_pn; 516 517 for (i = CCMP_PN_LEN - 1; i >= 0; i--) { 518 pn[i]++; 519 if (pn[i]) 520 break; 521 } 522 523 ccmp_pn2hdr(pos, pn, key->keyidx); 524 525 if (!key->force_sw_encrypt) { 526 /* hwaccel - with preallocated room for CCMP header */ 527 tx->u.tx.control->key_idx = key->hw_key_idx; 528 return 0; 529 } 530 531 pos += CCMP_HDR_LEN; 532 ccmp_special_blocks(skb, pn, b_0, aad, 0); 533 ieee80211_aes_ccm_encrypt(key->u.ccmp.tfm, scratch, b_0, aad, pos, len, 534 pos, skb_put(skb, CCMP_MIC_LEN)); 535 536 return 0; 537 } 538 539 540 ieee80211_txrx_result 541 ieee80211_tx_h_ccmp_encrypt(struct ieee80211_txrx_data *tx) 542 { 543 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) tx->skb->data; 544 struct ieee80211_key *key = tx->key; 545 u16 fc; 546 struct sk_buff *skb = tx->skb; 547 int test = 0; 548 549 fc = le16_to_cpu(hdr->frame_control); 550 551 if (!key || key->alg != ALG_CCMP || !WLAN_FC_DATA_PRESENT(fc)) 552 return TXRX_CONTINUE; 553 554 tx->u.tx.control->icv_len = CCMP_MIC_LEN; 555 tx->u.tx.control->iv_len = CCMP_HDR_LEN; 556 ieee80211_tx_set_iswep(tx); 557 558 if (!tx->key->force_sw_encrypt && 559 !(tx->local->hw.flags & IEEE80211_HW_WEP_INCLUDE_IV)) { 560 /* hwaccel - with no need for preallocated room for CCMP " 561 * header or MIC fields */ 562 tx->u.tx.control->key_idx = tx->key->hw_key_idx; 563 return TXRX_CONTINUE; 564 } 565 566 if (ccmp_encrypt_skb(tx, skb, test) < 0) 567 return TXRX_DROP; 568 569 if (tx->u.tx.extra_frag) { 570 int i; 571 572 for (i = 0; i < tx->u.tx.num_extra_frag; i++) { 573 if (ccmp_encrypt_skb(tx, tx->u.tx.extra_frag[i], test) 574 < 0) 575 return TXRX_DROP; 576 } 577 } 578 579 return TXRX_CONTINUE; 580 } 581 582 583 ieee80211_txrx_result 584 ieee80211_rx_h_ccmp_decrypt(struct ieee80211_txrx_data *rx) 585 { 586 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) rx->skb->data; 587 u16 fc; 588 int hdrlen; 589 struct ieee80211_key *key = rx->key; 590 struct sk_buff *skb = rx->skb; 591 u8 pn[CCMP_PN_LEN]; 592 int data_len; 593 594 fc = le16_to_cpu(hdr->frame_control); 595 hdrlen = ieee80211_get_hdrlen(fc); 596 597 if (!key || key->alg != ALG_CCMP || 598 !(rx->fc & IEEE80211_FCTL_PROTECTED) || 599 (rx->fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_DATA) 600 return TXRX_CONTINUE; 601 602 data_len = skb->len - hdrlen - CCMP_HDR_LEN - CCMP_MIC_LEN; 603 if (!rx->sta || data_len < 0) 604 return TXRX_DROP; 605 606 if ((rx->u.rx.status->flag & RX_FLAG_DECRYPTED) && 607 !key->force_sw_encrypt && 608 !(rx->local->hw.flags & IEEE80211_HW_WEP_INCLUDE_IV)) 609 return TXRX_CONTINUE; 610 611 (void) ccmp_hdr2pn(pn, skb->data + hdrlen); 612 613 if (memcmp(pn, key->u.ccmp.rx_pn[rx->u.rx.queue], CCMP_PN_LEN) <= 0) { 614 #ifdef CONFIG_MAC80211_DEBUG 615 u8 *ppn = key->u.ccmp.rx_pn[rx->u.rx.queue]; 616 printk(KERN_DEBUG "%s: CCMP replay detected for RX frame from " 617 MAC_FMT " (RX PN %02x%02x%02x%02x%02x%02x <= prev. PN " 618 "%02x%02x%02x%02x%02x%02x)\n", rx->dev->name, 619 MAC_ARG(rx->sta->addr), 620 pn[0], pn[1], pn[2], pn[3], pn[4], pn[5], 621 ppn[0], ppn[1], ppn[2], ppn[3], ppn[4], ppn[5]); 622 #endif /* CONFIG_MAC80211_DEBUG */ 623 key->u.ccmp.replays++; 624 return TXRX_DROP; 625 } 626 627 if ((rx->u.rx.status->flag & RX_FLAG_DECRYPTED) && 628 !key->force_sw_encrypt) { 629 /* hwaccel has already decrypted frame and verified MIC */ 630 } else { 631 u8 *scratch, *b_0, *aad; 632 633 scratch = key->u.ccmp.rx_crypto_buf; 634 b_0 = scratch + 3 * AES_BLOCK_LEN; 635 aad = scratch + 4 * AES_BLOCK_LEN; 636 637 ccmp_special_blocks(skb, pn, b_0, aad, 1); 638 639 if (ieee80211_aes_ccm_decrypt( 640 key->u.ccmp.tfm, scratch, b_0, aad, 641 skb->data + hdrlen + CCMP_HDR_LEN, data_len, 642 skb->data + skb->len - CCMP_MIC_LEN, 643 skb->data + hdrlen + CCMP_HDR_LEN)) { 644 printk(KERN_DEBUG "%s: CCMP decrypt failed for RX " 645 "frame from " MAC_FMT "\n", rx->dev->name, 646 MAC_ARG(rx->sta->addr)); 647 return TXRX_DROP; 648 } 649 } 650 651 memcpy(key->u.ccmp.rx_pn[rx->u.rx.queue], pn, CCMP_PN_LEN); 652 653 /* Remove CCMP header and MIC */ 654 skb_trim(skb, skb->len - CCMP_MIC_LEN); 655 memmove(skb->data + CCMP_HDR_LEN, skb->data, hdrlen); 656 skb_pull(skb, CCMP_HDR_LEN); 657 658 return TXRX_CONTINUE; 659 } 660 661