1 /* 2 * Copyright 2002-2004, Instant802 Networks, Inc. 3 * Copyright 2008, Jouni Malinen <j@w1.fi> 4 * 5 * This program is free software; you can redistribute it and/or modify 6 * it under the terms of the GNU General Public License version 2 as 7 * published by the Free Software Foundation. 8 */ 9 10 #include <linux/netdevice.h> 11 #include <linux/types.h> 12 #include <linux/skbuff.h> 13 #include <linux/compiler.h> 14 #include <linux/ieee80211.h> 15 #include <linux/gfp.h> 16 #include <asm/unaligned.h> 17 #include <net/mac80211.h> 18 #include <crypto/aes.h> 19 20 #include "ieee80211_i.h" 21 #include "michael.h" 22 #include "tkip.h" 23 #include "aes_ccm.h" 24 #include "aes_cmac.h" 25 #include "wpa.h" 26 27 ieee80211_tx_result 28 ieee80211_tx_h_michael_mic_add(struct ieee80211_tx_data *tx) 29 { 30 u8 *data, *key, *mic; 31 size_t data_len; 32 unsigned int hdrlen; 33 struct ieee80211_hdr *hdr; 34 struct sk_buff *skb = tx->skb; 35 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb); 36 int tail; 37 38 hdr = (struct ieee80211_hdr *)skb->data; 39 if (!tx->key || tx->key->conf.cipher != WLAN_CIPHER_SUITE_TKIP || 40 skb->len < 24 || !ieee80211_is_data_present(hdr->frame_control)) 41 return TX_CONTINUE; 42 43 hdrlen = ieee80211_hdrlen(hdr->frame_control); 44 if (skb->len < hdrlen) 45 return TX_DROP; 46 47 data = skb->data + hdrlen; 48 data_len = skb->len - hdrlen; 49 50 if (unlikely(info->flags & IEEE80211_TX_INTFL_TKIP_MIC_FAILURE)) { 51 /* Need to use software crypto for the test */ 52 info->control.hw_key = NULL; 53 } 54 55 if (info->control.hw_key && 56 (info->flags & IEEE80211_TX_CTL_DONTFRAG || 57 tx->local->ops->set_frag_threshold) && 58 !(tx->key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_MMIC)) { 59 /* hwaccel - with no need for SW-generated MMIC */ 60 return TX_CONTINUE; 61 } 62 63 tail = MICHAEL_MIC_LEN; 64 if (!info->control.hw_key) 65 tail += TKIP_ICV_LEN; 66 67 if (WARN_ON(skb_tailroom(skb) < tail || 68 skb_headroom(skb) < TKIP_IV_LEN)) 69 return TX_DROP; 70 71 key = &tx->key->conf.key[NL80211_TKIP_DATA_OFFSET_TX_MIC_KEY]; 72 mic = skb_put(skb, MICHAEL_MIC_LEN); 73 michael_mic(key, hdr, data, data_len, mic); 74 if (unlikely(info->flags & IEEE80211_TX_INTFL_TKIP_MIC_FAILURE)) 75 mic[0]++; 76 77 return TX_CONTINUE; 78 } 79 80 81 ieee80211_rx_result 82 ieee80211_rx_h_michael_mic_verify(struct ieee80211_rx_data *rx) 83 { 84 u8 *data, *key = NULL; 85 size_t data_len; 86 unsigned int hdrlen; 87 u8 mic[MICHAEL_MIC_LEN]; 88 struct sk_buff *skb = rx->skb; 89 struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb); 90 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data; 91 92 /* 93 * it makes no sense to check for MIC errors on anything other 94 * than data frames. 95 */ 96 if (!ieee80211_is_data_present(hdr->frame_control)) 97 return RX_CONTINUE; 98 99 /* 100 * No way to verify the MIC if the hardware stripped it or 101 * the IV with the key index. In this case we have solely rely 102 * on the driver to set RX_FLAG_MMIC_ERROR in the event of a 103 * MIC failure report. 104 */ 105 if (status->flag & (RX_FLAG_MMIC_STRIPPED | RX_FLAG_IV_STRIPPED)) { 106 if (status->flag & RX_FLAG_MMIC_ERROR) 107 goto mic_fail; 108 109 if (!(status->flag & RX_FLAG_IV_STRIPPED) && rx->key) 110 goto update_iv; 111 112 return RX_CONTINUE; 113 } 114 115 /* 116 * Some hardware seems to generate Michael MIC failure reports; even 117 * though, the frame was not encrypted with TKIP and therefore has no 118 * MIC. Ignore the flag them to avoid triggering countermeasures. 119 */ 120 if (!rx->key || rx->key->conf.cipher != WLAN_CIPHER_SUITE_TKIP || 121 !(status->flag & RX_FLAG_DECRYPTED)) 122 return RX_CONTINUE; 123 124 if (rx->sdata->vif.type == NL80211_IFTYPE_AP && rx->key->conf.keyidx) { 125 /* 126 * APs with pairwise keys should never receive Michael MIC 127 * errors for non-zero keyidx because these are reserved for 128 * group keys and only the AP is sending real multicast 129 * frames in the BSS. ( 130 */ 131 return RX_DROP_UNUSABLE; 132 } 133 134 if (status->flag & RX_FLAG_MMIC_ERROR) 135 goto mic_fail; 136 137 hdrlen = ieee80211_hdrlen(hdr->frame_control); 138 if (skb->len < hdrlen + MICHAEL_MIC_LEN) 139 return RX_DROP_UNUSABLE; 140 141 if (skb_linearize(rx->skb)) 142 return RX_DROP_UNUSABLE; 143 hdr = (void *)skb->data; 144 145 data = skb->data + hdrlen; 146 data_len = skb->len - hdrlen - MICHAEL_MIC_LEN; 147 key = &rx->key->conf.key[NL80211_TKIP_DATA_OFFSET_RX_MIC_KEY]; 148 michael_mic(key, hdr, data, data_len, mic); 149 if (memcmp(mic, data + data_len, MICHAEL_MIC_LEN) != 0) 150 goto mic_fail; 151 152 /* remove Michael MIC from payload */ 153 skb_trim(skb, skb->len - MICHAEL_MIC_LEN); 154 155 update_iv: 156 /* update IV in key information to be able to detect replays */ 157 rx->key->u.tkip.rx[rx->security_idx].iv32 = rx->tkip_iv32; 158 rx->key->u.tkip.rx[rx->security_idx].iv16 = rx->tkip_iv16; 159 160 return RX_CONTINUE; 161 162 mic_fail: 163 /* 164 * In some cases the key can be unset - e.g. a multicast packet, in 165 * a driver that supports HW encryption. Send up the key idx only if 166 * the key is set. 167 */ 168 mac80211_ev_michael_mic_failure(rx->sdata, 169 rx->key ? rx->key->conf.keyidx : -1, 170 (void *) skb->data, NULL, GFP_ATOMIC); 171 return RX_DROP_UNUSABLE; 172 } 173 174 175 static int tkip_encrypt_skb(struct ieee80211_tx_data *tx, struct sk_buff *skb) 176 { 177 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data; 178 struct ieee80211_key *key = tx->key; 179 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb); 180 unsigned long flags; 181 unsigned int hdrlen; 182 int len, tail; 183 u8 *pos; 184 185 if (info->control.hw_key && 186 !(info->control.hw_key->flags & IEEE80211_KEY_FLAG_GENERATE_IV)) { 187 /* hwaccel - with no need for software-generated IV */ 188 return 0; 189 } 190 191 hdrlen = ieee80211_hdrlen(hdr->frame_control); 192 len = skb->len - hdrlen; 193 194 if (info->control.hw_key) 195 tail = 0; 196 else 197 tail = TKIP_ICV_LEN; 198 199 if (WARN_ON(skb_tailroom(skb) < tail || 200 skb_headroom(skb) < TKIP_IV_LEN)) 201 return -1; 202 203 pos = skb_push(skb, TKIP_IV_LEN); 204 memmove(pos, pos + TKIP_IV_LEN, hdrlen); 205 pos += hdrlen; 206 207 /* Increase IV for the frame */ 208 spin_lock_irqsave(&key->u.tkip.txlock, flags); 209 key->u.tkip.tx.iv16++; 210 if (key->u.tkip.tx.iv16 == 0) 211 key->u.tkip.tx.iv32++; 212 pos = ieee80211_tkip_add_iv(pos, key); 213 spin_unlock_irqrestore(&key->u.tkip.txlock, flags); 214 215 /* hwaccel - with software IV */ 216 if (info->control.hw_key) 217 return 0; 218 219 /* Add room for ICV */ 220 skb_put(skb, TKIP_ICV_LEN); 221 222 return ieee80211_tkip_encrypt_data(tx->local->wep_tx_tfm, 223 key, skb, pos, len); 224 } 225 226 227 ieee80211_tx_result 228 ieee80211_crypto_tkip_encrypt(struct ieee80211_tx_data *tx) 229 { 230 struct sk_buff *skb; 231 232 ieee80211_tx_set_protected(tx); 233 234 skb_queue_walk(&tx->skbs, skb) { 235 if (tkip_encrypt_skb(tx, skb) < 0) 236 return TX_DROP; 237 } 238 239 return TX_CONTINUE; 240 } 241 242 243 ieee80211_rx_result 244 ieee80211_crypto_tkip_decrypt(struct ieee80211_rx_data *rx) 245 { 246 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) rx->skb->data; 247 int hdrlen, res, hwaccel = 0; 248 struct ieee80211_key *key = rx->key; 249 struct sk_buff *skb = rx->skb; 250 struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb); 251 252 hdrlen = ieee80211_hdrlen(hdr->frame_control); 253 254 if (!ieee80211_is_data(hdr->frame_control)) 255 return RX_CONTINUE; 256 257 if (!rx->sta || skb->len - hdrlen < 12) 258 return RX_DROP_UNUSABLE; 259 260 /* it may be possible to optimize this a bit more */ 261 if (skb_linearize(rx->skb)) 262 return RX_DROP_UNUSABLE; 263 hdr = (void *)skb->data; 264 265 /* 266 * Let TKIP code verify IV, but skip decryption. 267 * In the case where hardware checks the IV as well, 268 * we don't even get here, see ieee80211_rx_h_decrypt() 269 */ 270 if (status->flag & RX_FLAG_DECRYPTED) 271 hwaccel = 1; 272 273 res = ieee80211_tkip_decrypt_data(rx->local->wep_rx_tfm, 274 key, skb->data + hdrlen, 275 skb->len - hdrlen, rx->sta->sta.addr, 276 hdr->addr1, hwaccel, rx->security_idx, 277 &rx->tkip_iv32, 278 &rx->tkip_iv16); 279 if (res != TKIP_DECRYPT_OK) 280 return RX_DROP_UNUSABLE; 281 282 /* Trim ICV */ 283 skb_trim(skb, skb->len - TKIP_ICV_LEN); 284 285 /* Remove IV */ 286 memmove(skb->data + TKIP_IV_LEN, skb->data, hdrlen); 287 skb_pull(skb, TKIP_IV_LEN); 288 289 return RX_CONTINUE; 290 } 291 292 293 static void ccmp_special_blocks(struct sk_buff *skb, u8 *pn, u8 *scratch, 294 int encrypted) 295 { 296 __le16 mask_fc; 297 int a4_included, mgmt; 298 u8 qos_tid; 299 u8 *b_0, *aad; 300 u16 data_len, len_a; 301 unsigned int hdrlen; 302 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data; 303 304 memset(scratch, 0, 6 * AES_BLOCK_SIZE); 305 306 b_0 = scratch + 3 * AES_BLOCK_SIZE; 307 aad = scratch + 4 * AES_BLOCK_SIZE; 308 309 /* 310 * Mask FC: zero subtype b4 b5 b6 (if not mgmt) 311 * Retry, PwrMgt, MoreData; set Protected 312 */ 313 mgmt = ieee80211_is_mgmt(hdr->frame_control); 314 mask_fc = hdr->frame_control; 315 mask_fc &= ~cpu_to_le16(IEEE80211_FCTL_RETRY | 316 IEEE80211_FCTL_PM | IEEE80211_FCTL_MOREDATA); 317 if (!mgmt) 318 mask_fc &= ~cpu_to_le16(0x0070); 319 mask_fc |= cpu_to_le16(IEEE80211_FCTL_PROTECTED); 320 321 hdrlen = ieee80211_hdrlen(hdr->frame_control); 322 len_a = hdrlen - 2; 323 a4_included = ieee80211_has_a4(hdr->frame_control); 324 325 if (ieee80211_is_data_qos(hdr->frame_control)) 326 qos_tid = *ieee80211_get_qos_ctl(hdr) & IEEE80211_QOS_CTL_TID_MASK; 327 else 328 qos_tid = 0; 329 330 data_len = skb->len - hdrlen - CCMP_HDR_LEN; 331 if (encrypted) 332 data_len -= CCMP_MIC_LEN; 333 334 /* First block, b_0 */ 335 b_0[0] = 0x59; /* flags: Adata: 1, M: 011, L: 001 */ 336 /* Nonce: Nonce Flags | A2 | PN 337 * Nonce Flags: Priority (b0..b3) | Management (b4) | Reserved (b5..b7) 338 */ 339 b_0[1] = qos_tid | (mgmt << 4); 340 memcpy(&b_0[2], hdr->addr2, ETH_ALEN); 341 memcpy(&b_0[8], pn, CCMP_PN_LEN); 342 /* l(m) */ 343 put_unaligned_be16(data_len, &b_0[14]); 344 345 /* AAD (extra authenticate-only data) / masked 802.11 header 346 * FC | A1 | A2 | A3 | SC | [A4] | [QC] */ 347 put_unaligned_be16(len_a, &aad[0]); 348 put_unaligned(mask_fc, (__le16 *)&aad[2]); 349 memcpy(&aad[4], &hdr->addr1, 3 * ETH_ALEN); 350 351 /* Mask Seq#, leave Frag# */ 352 aad[22] = *((u8 *) &hdr->seq_ctrl) & 0x0f; 353 aad[23] = 0; 354 355 if (a4_included) { 356 memcpy(&aad[24], hdr->addr4, ETH_ALEN); 357 aad[30] = qos_tid; 358 aad[31] = 0; 359 } else { 360 memset(&aad[24], 0, ETH_ALEN + IEEE80211_QOS_CTL_LEN); 361 aad[24] = qos_tid; 362 } 363 } 364 365 366 static inline void ccmp_pn2hdr(u8 *hdr, u8 *pn, int key_id) 367 { 368 hdr[0] = pn[5]; 369 hdr[1] = pn[4]; 370 hdr[2] = 0; 371 hdr[3] = 0x20 | (key_id << 6); 372 hdr[4] = pn[3]; 373 hdr[5] = pn[2]; 374 hdr[6] = pn[1]; 375 hdr[7] = pn[0]; 376 } 377 378 379 static inline void ccmp_hdr2pn(u8 *pn, u8 *hdr) 380 { 381 pn[0] = hdr[7]; 382 pn[1] = hdr[6]; 383 pn[2] = hdr[5]; 384 pn[3] = hdr[4]; 385 pn[4] = hdr[1]; 386 pn[5] = hdr[0]; 387 } 388 389 390 static int ccmp_encrypt_skb(struct ieee80211_tx_data *tx, struct sk_buff *skb) 391 { 392 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data; 393 struct ieee80211_key *key = tx->key; 394 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb); 395 int hdrlen, len, tail; 396 u8 *pos; 397 u8 pn[6]; 398 u64 pn64; 399 u8 scratch[6 * AES_BLOCK_SIZE]; 400 401 if (info->control.hw_key && 402 !(info->control.hw_key->flags & IEEE80211_KEY_FLAG_GENERATE_IV) && 403 !(info->control.hw_key->flags & IEEE80211_KEY_FLAG_PUT_IV_SPACE)) { 404 /* 405 * hwaccel has no need for preallocated room for CCMP 406 * header or MIC fields 407 */ 408 return 0; 409 } 410 411 hdrlen = ieee80211_hdrlen(hdr->frame_control); 412 len = skb->len - hdrlen; 413 414 if (info->control.hw_key) 415 tail = 0; 416 else 417 tail = CCMP_MIC_LEN; 418 419 if (WARN_ON(skb_tailroom(skb) < tail || 420 skb_headroom(skb) < CCMP_HDR_LEN)) 421 return -1; 422 423 pos = skb_push(skb, CCMP_HDR_LEN); 424 memmove(pos, pos + CCMP_HDR_LEN, hdrlen); 425 426 /* the HW only needs room for the IV, but not the actual IV */ 427 if (info->control.hw_key && 428 (info->control.hw_key->flags & IEEE80211_KEY_FLAG_PUT_IV_SPACE)) 429 return 0; 430 431 hdr = (struct ieee80211_hdr *) pos; 432 pos += hdrlen; 433 434 pn64 = atomic64_inc_return(&key->u.ccmp.tx_pn); 435 436 pn[5] = pn64; 437 pn[4] = pn64 >> 8; 438 pn[3] = pn64 >> 16; 439 pn[2] = pn64 >> 24; 440 pn[1] = pn64 >> 32; 441 pn[0] = pn64 >> 40; 442 443 ccmp_pn2hdr(pos, pn, key->conf.keyidx); 444 445 /* hwaccel - with software CCMP header */ 446 if (info->control.hw_key) 447 return 0; 448 449 pos += CCMP_HDR_LEN; 450 ccmp_special_blocks(skb, pn, scratch, 0); 451 ieee80211_aes_ccm_encrypt(key->u.ccmp.tfm, scratch, pos, len, 452 pos, skb_put(skb, CCMP_MIC_LEN)); 453 454 return 0; 455 } 456 457 458 ieee80211_tx_result 459 ieee80211_crypto_ccmp_encrypt(struct ieee80211_tx_data *tx) 460 { 461 struct sk_buff *skb; 462 463 ieee80211_tx_set_protected(tx); 464 465 skb_queue_walk(&tx->skbs, skb) { 466 if (ccmp_encrypt_skb(tx, skb) < 0) 467 return TX_DROP; 468 } 469 470 return TX_CONTINUE; 471 } 472 473 474 ieee80211_rx_result 475 ieee80211_crypto_ccmp_decrypt(struct ieee80211_rx_data *rx) 476 { 477 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data; 478 int hdrlen; 479 struct ieee80211_key *key = rx->key; 480 struct sk_buff *skb = rx->skb; 481 struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb); 482 u8 pn[CCMP_PN_LEN]; 483 int data_len; 484 int queue; 485 486 hdrlen = ieee80211_hdrlen(hdr->frame_control); 487 488 if (!ieee80211_is_data(hdr->frame_control) && 489 !ieee80211_is_robust_mgmt_frame(hdr)) 490 return RX_CONTINUE; 491 492 data_len = skb->len - hdrlen - CCMP_HDR_LEN - CCMP_MIC_LEN; 493 if (!rx->sta || data_len < 0) 494 return RX_DROP_UNUSABLE; 495 496 if (status->flag & RX_FLAG_DECRYPTED) { 497 if (!pskb_may_pull(rx->skb, hdrlen + CCMP_HDR_LEN)) 498 return RX_DROP_UNUSABLE; 499 } else { 500 if (skb_linearize(rx->skb)) 501 return RX_DROP_UNUSABLE; 502 } 503 504 ccmp_hdr2pn(pn, skb->data + hdrlen); 505 506 queue = rx->security_idx; 507 508 if (memcmp(pn, key->u.ccmp.rx_pn[queue], CCMP_PN_LEN) <= 0) { 509 key->u.ccmp.replays++; 510 return RX_DROP_UNUSABLE; 511 } 512 513 if (!(status->flag & RX_FLAG_DECRYPTED)) { 514 u8 scratch[6 * AES_BLOCK_SIZE]; 515 /* hardware didn't decrypt/verify MIC */ 516 ccmp_special_blocks(skb, pn, scratch, 1); 517 518 if (ieee80211_aes_ccm_decrypt( 519 key->u.ccmp.tfm, scratch, 520 skb->data + hdrlen + CCMP_HDR_LEN, data_len, 521 skb->data + skb->len - CCMP_MIC_LEN, 522 skb->data + hdrlen + CCMP_HDR_LEN)) 523 return RX_DROP_UNUSABLE; 524 } 525 526 memcpy(key->u.ccmp.rx_pn[queue], pn, CCMP_PN_LEN); 527 528 /* Remove CCMP header and MIC */ 529 if (pskb_trim(skb, skb->len - CCMP_MIC_LEN)) 530 return RX_DROP_UNUSABLE; 531 memmove(skb->data + CCMP_HDR_LEN, skb->data, hdrlen); 532 skb_pull(skb, CCMP_HDR_LEN); 533 534 return RX_CONTINUE; 535 } 536 537 538 static void bip_aad(struct sk_buff *skb, u8 *aad) 539 { 540 /* BIP AAD: FC(masked) || A1 || A2 || A3 */ 541 542 /* FC type/subtype */ 543 aad[0] = skb->data[0]; 544 /* Mask FC Retry, PwrMgt, MoreData flags to zero */ 545 aad[1] = skb->data[1] & ~(BIT(4) | BIT(5) | BIT(6)); 546 /* A1 || A2 || A3 */ 547 memcpy(aad + 2, skb->data + 4, 3 * ETH_ALEN); 548 } 549 550 551 static inline void bip_ipn_set64(u8 *d, u64 pn) 552 { 553 *d++ = pn; 554 *d++ = pn >> 8; 555 *d++ = pn >> 16; 556 *d++ = pn >> 24; 557 *d++ = pn >> 32; 558 *d = pn >> 40; 559 } 560 561 static inline void bip_ipn_swap(u8 *d, const u8 *s) 562 { 563 *d++ = s[5]; 564 *d++ = s[4]; 565 *d++ = s[3]; 566 *d++ = s[2]; 567 *d++ = s[1]; 568 *d = s[0]; 569 } 570 571 572 ieee80211_tx_result 573 ieee80211_crypto_aes_cmac_encrypt(struct ieee80211_tx_data *tx) 574 { 575 struct sk_buff *skb; 576 struct ieee80211_tx_info *info; 577 struct ieee80211_key *key = tx->key; 578 struct ieee80211_mmie *mmie; 579 u8 aad[20]; 580 u64 pn64; 581 582 if (WARN_ON(skb_queue_len(&tx->skbs) != 1)) 583 return TX_DROP; 584 585 skb = skb_peek(&tx->skbs); 586 587 info = IEEE80211_SKB_CB(skb); 588 589 if (info->control.hw_key) 590 return TX_CONTINUE; 591 592 if (WARN_ON(skb_tailroom(skb) < sizeof(*mmie))) 593 return TX_DROP; 594 595 mmie = (struct ieee80211_mmie *) skb_put(skb, sizeof(*mmie)); 596 mmie->element_id = WLAN_EID_MMIE; 597 mmie->length = sizeof(*mmie) - 2; 598 mmie->key_id = cpu_to_le16(key->conf.keyidx); 599 600 /* PN = PN + 1 */ 601 pn64 = atomic64_inc_return(&key->u.aes_cmac.tx_pn); 602 603 bip_ipn_set64(mmie->sequence_number, pn64); 604 605 bip_aad(skb, aad); 606 607 /* 608 * MIC = AES-128-CMAC(IGTK, AAD || Management Frame Body || MMIE, 64) 609 */ 610 ieee80211_aes_cmac(key->u.aes_cmac.tfm, aad, 611 skb->data + 24, skb->len - 24, mmie->mic); 612 613 return TX_CONTINUE; 614 } 615 616 617 ieee80211_rx_result 618 ieee80211_crypto_aes_cmac_decrypt(struct ieee80211_rx_data *rx) 619 { 620 struct sk_buff *skb = rx->skb; 621 struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb); 622 struct ieee80211_key *key = rx->key; 623 struct ieee80211_mmie *mmie; 624 u8 aad[20], mic[8], ipn[6]; 625 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data; 626 627 if (!ieee80211_is_mgmt(hdr->frame_control)) 628 return RX_CONTINUE; 629 630 /* management frames are already linear */ 631 632 if (skb->len < 24 + sizeof(*mmie)) 633 return RX_DROP_UNUSABLE; 634 635 mmie = (struct ieee80211_mmie *) 636 (skb->data + skb->len - sizeof(*mmie)); 637 if (mmie->element_id != WLAN_EID_MMIE || 638 mmie->length != sizeof(*mmie) - 2) 639 return RX_DROP_UNUSABLE; /* Invalid MMIE */ 640 641 bip_ipn_swap(ipn, mmie->sequence_number); 642 643 if (memcmp(ipn, key->u.aes_cmac.rx_pn, 6) <= 0) { 644 key->u.aes_cmac.replays++; 645 return RX_DROP_UNUSABLE; 646 } 647 648 if (!(status->flag & RX_FLAG_DECRYPTED)) { 649 /* hardware didn't decrypt/verify MIC */ 650 bip_aad(skb, aad); 651 ieee80211_aes_cmac(key->u.aes_cmac.tfm, aad, 652 skb->data + 24, skb->len - 24, mic); 653 if (memcmp(mic, mmie->mic, sizeof(mmie->mic)) != 0) { 654 key->u.aes_cmac.icverrors++; 655 return RX_DROP_UNUSABLE; 656 } 657 } 658 659 memcpy(key->u.aes_cmac.rx_pn, ipn, 6); 660 661 /* Remove MMIE */ 662 skb_trim(skb, skb->len - sizeof(*mmie)); 663 664 return RX_CONTINUE; 665 } 666 667 ieee80211_tx_result 668 ieee80211_crypto_hw_encrypt(struct ieee80211_tx_data *tx) 669 { 670 struct sk_buff *skb; 671 struct ieee80211_tx_info *info = NULL; 672 673 skb_queue_walk(&tx->skbs, skb) { 674 info = IEEE80211_SKB_CB(skb); 675 676 /* handle hw-only algorithm */ 677 if (!info->control.hw_key) 678 return TX_DROP; 679 } 680 681 ieee80211_tx_set_protected(tx); 682 683 return TX_CONTINUE; 684 } 685