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 19 #include "ieee80211_i.h" 20 #include "michael.h" 21 #include "tkip.h" 22 #include "aes_ccm.h" 23 #include "aes_cmac.h" 24 #include "wpa.h" 25 26 ieee80211_tx_result 27 ieee80211_tx_h_michael_mic_add(struct ieee80211_tx_data *tx) 28 { 29 u8 *data, *key, *mic; 30 size_t data_len; 31 unsigned int hdrlen; 32 struct ieee80211_hdr *hdr; 33 struct sk_buff *skb = tx->skb; 34 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb); 35 int tail; 36 37 hdr = (struct ieee80211_hdr *)skb->data; 38 if (!tx->key || tx->key->conf.cipher != WLAN_CIPHER_SUITE_TKIP || 39 skb->len < 24 || !ieee80211_is_data_present(hdr->frame_control)) 40 return TX_CONTINUE; 41 42 hdrlen = ieee80211_hdrlen(hdr->frame_control); 43 if (skb->len < hdrlen) 44 return TX_DROP; 45 46 data = skb->data + hdrlen; 47 data_len = skb->len - hdrlen; 48 49 if (unlikely(info->flags & IEEE80211_TX_INTFL_TKIP_MIC_FAILURE)) { 50 /* Need to use software crypto for the test */ 51 info->control.hw_key = NULL; 52 } 53 54 if (info->control.hw_key && 55 !(tx->flags & IEEE80211_TX_FRAGMENTED) && 56 !(tx->key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_MMIC)) { 57 /* hwaccel - with no need for SW-generated MMIC */ 58 return TX_CONTINUE; 59 } 60 61 tail = MICHAEL_MIC_LEN; 62 if (!info->control.hw_key) 63 tail += TKIP_ICV_LEN; 64 65 if (WARN_ON(skb_tailroom(skb) < tail || 66 skb_headroom(skb) < TKIP_IV_LEN)) 67 return TX_DROP; 68 69 key = &tx->key->conf.key[NL80211_TKIP_DATA_OFFSET_TX_MIC_KEY]; 70 mic = skb_put(skb, MICHAEL_MIC_LEN); 71 michael_mic(key, hdr, data, data_len, mic); 72 if (unlikely(info->flags & IEEE80211_TX_INTFL_TKIP_MIC_FAILURE)) 73 mic[0]++; 74 75 return TX_CONTINUE; 76 } 77 78 79 ieee80211_rx_result 80 ieee80211_rx_h_michael_mic_verify(struct ieee80211_rx_data *rx) 81 { 82 u8 *data, *key = NULL; 83 size_t data_len; 84 unsigned int hdrlen; 85 u8 mic[MICHAEL_MIC_LEN]; 86 struct sk_buff *skb = rx->skb; 87 struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb); 88 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data; 89 int queue = rx->queue; 90 91 /* otherwise, TKIP is vulnerable to TID 0 vs. non-QoS replays */ 92 if (rx->queue == NUM_RX_DATA_QUEUES - 1) 93 queue = 0; 94 95 /* 96 * it makes no sense to check for MIC errors on anything other 97 * than data frames. 98 */ 99 if (!ieee80211_is_data_present(hdr->frame_control)) 100 return RX_CONTINUE; 101 102 /* 103 * No way to verify the MIC if the hardware stripped it or 104 * the IV with the key index. In this case we have solely rely 105 * on the driver to set RX_FLAG_MMIC_ERROR in the event of a 106 * MIC failure report. 107 */ 108 if (status->flag & (RX_FLAG_MMIC_STRIPPED | RX_FLAG_IV_STRIPPED)) { 109 if (status->flag & RX_FLAG_MMIC_ERROR) 110 goto mic_fail; 111 112 if (!(status->flag & RX_FLAG_IV_STRIPPED)) 113 goto update_iv; 114 115 return RX_CONTINUE; 116 } 117 118 /* 119 * Some hardware seems to generate Michael MIC failure reports; even 120 * though, the frame was not encrypted with TKIP and therefore has no 121 * MIC. Ignore the flag them to avoid triggering countermeasures. 122 */ 123 if (!rx->key || rx->key->conf.cipher != WLAN_CIPHER_SUITE_TKIP || 124 !(status->flag & RX_FLAG_DECRYPTED)) 125 return RX_CONTINUE; 126 127 if (rx->sdata->vif.type == NL80211_IFTYPE_AP && rx->key->conf.keyidx) { 128 /* 129 * APs with pairwise keys should never receive Michael MIC 130 * errors for non-zero keyidx because these are reserved for 131 * group keys and only the AP is sending real multicast 132 * frames in the BSS. ( 133 */ 134 return RX_DROP_UNUSABLE; 135 } 136 137 if (status->flag & RX_FLAG_MMIC_ERROR) 138 goto mic_fail; 139 140 hdrlen = ieee80211_hdrlen(hdr->frame_control); 141 if (skb->len < hdrlen + MICHAEL_MIC_LEN) 142 return RX_DROP_UNUSABLE; 143 144 data = skb->data + hdrlen; 145 data_len = skb->len - hdrlen - MICHAEL_MIC_LEN; 146 key = &rx->key->conf.key[NL80211_TKIP_DATA_OFFSET_RX_MIC_KEY]; 147 michael_mic(key, hdr, data, data_len, mic); 148 if (memcmp(mic, data + data_len, MICHAEL_MIC_LEN) != 0) 149 goto mic_fail; 150 151 /* remove Michael MIC from payload */ 152 skb_trim(skb, skb->len - MICHAEL_MIC_LEN); 153 154 update_iv: 155 /* update IV in key information to be able to detect replays */ 156 rx->key->u.tkip.rx[queue].iv32 = rx->tkip_iv32; 157 rx->key->u.tkip.rx[queue].iv16 = rx->tkip_iv16; 158 159 return RX_CONTINUE; 160 161 mic_fail: 162 /* 163 * In some cases the key can be unset - e.g. a multicast packet, in 164 * a driver that supports HW encryption. Send up the key idx only if 165 * the key is set. 166 */ 167 mac80211_ev_michael_mic_failure(rx->sdata, 168 rx->key ? rx->key->conf.keyidx : -1, 169 (void *) skb->data, NULL, GFP_ATOMIC); 170 return RX_DROP_UNUSABLE; 171 } 172 173 174 static int tkip_encrypt_skb(struct ieee80211_tx_data *tx, struct sk_buff *skb) 175 { 176 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data; 177 struct ieee80211_key *key = tx->key; 178 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb); 179 unsigned int hdrlen; 180 int len, tail; 181 u8 *pos; 182 183 if (info->control.hw_key && 184 !(info->control.hw_key->flags & IEEE80211_KEY_FLAG_GENERATE_IV)) { 185 /* hwaccel - with no need for software-generated IV */ 186 return 0; 187 } 188 189 hdrlen = ieee80211_hdrlen(hdr->frame_control); 190 len = skb->len - hdrlen; 191 192 if (info->control.hw_key) 193 tail = 0; 194 else 195 tail = TKIP_ICV_LEN; 196 197 if (WARN_ON(skb_tailroom(skb) < tail || 198 skb_headroom(skb) < TKIP_IV_LEN)) 199 return -1; 200 201 pos = skb_push(skb, TKIP_IV_LEN); 202 memmove(pos, pos + TKIP_IV_LEN, hdrlen); 203 pos += hdrlen; 204 205 /* Increase IV for the frame */ 206 key->u.tkip.tx.iv16++; 207 if (key->u.tkip.tx.iv16 == 0) 208 key->u.tkip.tx.iv32++; 209 210 pos = ieee80211_tkip_add_iv(pos, key, key->u.tkip.tx.iv16); 211 212 /* hwaccel - with software IV */ 213 if (info->control.hw_key) 214 return 0; 215 216 /* Add room for ICV */ 217 skb_put(skb, TKIP_ICV_LEN); 218 219 hdr = (struct ieee80211_hdr *) skb->data; 220 return ieee80211_tkip_encrypt_data(tx->local->wep_tx_tfm, 221 key, pos, len, hdr->addr2); 222 } 223 224 225 ieee80211_tx_result 226 ieee80211_crypto_tkip_encrypt(struct ieee80211_tx_data *tx) 227 { 228 struct sk_buff *skb = tx->skb; 229 230 ieee80211_tx_set_protected(tx); 231 232 do { 233 if (tkip_encrypt_skb(tx, skb) < 0) 234 return TX_DROP; 235 } while ((skb = skb->next)); 236 237 return TX_CONTINUE; 238 } 239 240 241 ieee80211_rx_result 242 ieee80211_crypto_tkip_decrypt(struct ieee80211_rx_data *rx) 243 { 244 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) rx->skb->data; 245 int hdrlen, res, hwaccel = 0; 246 struct ieee80211_key *key = rx->key; 247 struct sk_buff *skb = rx->skb; 248 struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb); 249 int queue = rx->queue; 250 251 /* otherwise, TKIP is vulnerable to TID 0 vs. non-QoS replays */ 252 if (rx->queue == NUM_RX_DATA_QUEUES - 1) 253 queue = 0; 254 255 hdrlen = ieee80211_hdrlen(hdr->frame_control); 256 257 if (!ieee80211_is_data(hdr->frame_control)) 258 return RX_CONTINUE; 259 260 if (!rx->sta || skb->len - hdrlen < 12) 261 return RX_DROP_UNUSABLE; 262 263 /* 264 * Let TKIP code verify IV, but skip decryption. 265 * In the case where hardware checks the IV as well, 266 * we don't even get here, see ieee80211_rx_h_decrypt() 267 */ 268 if (status->flag & RX_FLAG_DECRYPTED) 269 hwaccel = 1; 270 271 res = ieee80211_tkip_decrypt_data(rx->local->wep_rx_tfm, 272 key, skb->data + hdrlen, 273 skb->len - hdrlen, rx->sta->sta.addr, 274 hdr->addr1, hwaccel, queue, 275 &rx->tkip_iv32, 276 &rx->tkip_iv16); 277 if (res != TKIP_DECRYPT_OK) 278 return RX_DROP_UNUSABLE; 279 280 /* Trim ICV */ 281 skb_trim(skb, skb->len - TKIP_ICV_LEN); 282 283 /* Remove IV */ 284 memmove(skb->data + TKIP_IV_LEN, skb->data, hdrlen); 285 skb_pull(skb, TKIP_IV_LEN); 286 287 return RX_CONTINUE; 288 } 289 290 291 static void ccmp_special_blocks(struct sk_buff *skb, u8 *pn, u8 *scratch, 292 int encrypted) 293 { 294 __le16 mask_fc; 295 int a4_included, mgmt; 296 u8 qos_tid; 297 u8 *b_0, *aad; 298 u16 data_len, len_a; 299 unsigned int hdrlen; 300 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data; 301 302 b_0 = scratch + 3 * AES_BLOCK_LEN; 303 aad = scratch + 4 * AES_BLOCK_LEN; 304 305 /* 306 * Mask FC: zero subtype b4 b5 b6 (if not mgmt) 307 * Retry, PwrMgt, MoreData; set Protected 308 */ 309 mgmt = ieee80211_is_mgmt(hdr->frame_control); 310 mask_fc = hdr->frame_control; 311 mask_fc &= ~cpu_to_le16(IEEE80211_FCTL_RETRY | 312 IEEE80211_FCTL_PM | IEEE80211_FCTL_MOREDATA); 313 if (!mgmt) 314 mask_fc &= ~cpu_to_le16(0x0070); 315 mask_fc |= cpu_to_le16(IEEE80211_FCTL_PROTECTED); 316 317 hdrlen = ieee80211_hdrlen(hdr->frame_control); 318 len_a = hdrlen - 2; 319 a4_included = ieee80211_has_a4(hdr->frame_control); 320 321 if (ieee80211_is_data_qos(hdr->frame_control)) 322 qos_tid = *ieee80211_get_qos_ctl(hdr) & IEEE80211_QOS_CTL_TID_MASK; 323 else 324 qos_tid = 0; 325 326 data_len = skb->len - hdrlen - CCMP_HDR_LEN; 327 if (encrypted) 328 data_len -= CCMP_MIC_LEN; 329 330 /* First block, b_0 */ 331 b_0[0] = 0x59; /* flags: Adata: 1, M: 011, L: 001 */ 332 /* Nonce: Nonce Flags | A2 | PN 333 * Nonce Flags: Priority (b0..b3) | Management (b4) | Reserved (b5..b7) 334 */ 335 b_0[1] = qos_tid | (mgmt << 4); 336 memcpy(&b_0[2], hdr->addr2, ETH_ALEN); 337 memcpy(&b_0[8], pn, CCMP_PN_LEN); 338 /* l(m) */ 339 put_unaligned_be16(data_len, &b_0[14]); 340 341 /* AAD (extra authenticate-only data) / masked 802.11 header 342 * FC | A1 | A2 | A3 | SC | [A4] | [QC] */ 343 put_unaligned_be16(len_a, &aad[0]); 344 put_unaligned(mask_fc, (__le16 *)&aad[2]); 345 memcpy(&aad[4], &hdr->addr1, 3 * ETH_ALEN); 346 347 /* Mask Seq#, leave Frag# */ 348 aad[22] = *((u8 *) &hdr->seq_ctrl) & 0x0f; 349 aad[23] = 0; 350 351 if (a4_included) { 352 memcpy(&aad[24], hdr->addr4, ETH_ALEN); 353 aad[30] = qos_tid; 354 aad[31] = 0; 355 } else { 356 memset(&aad[24], 0, ETH_ALEN + IEEE80211_QOS_CTL_LEN); 357 aad[24] = qos_tid; 358 } 359 } 360 361 362 static inline void ccmp_pn2hdr(u8 *hdr, u8 *pn, int key_id) 363 { 364 hdr[0] = pn[5]; 365 hdr[1] = pn[4]; 366 hdr[2] = 0; 367 hdr[3] = 0x20 | (key_id << 6); 368 hdr[4] = pn[3]; 369 hdr[5] = pn[2]; 370 hdr[6] = pn[1]; 371 hdr[7] = pn[0]; 372 } 373 374 375 static inline void ccmp_hdr2pn(u8 *pn, u8 *hdr) 376 { 377 pn[0] = hdr[7]; 378 pn[1] = hdr[6]; 379 pn[2] = hdr[5]; 380 pn[3] = hdr[4]; 381 pn[4] = hdr[1]; 382 pn[5] = hdr[0]; 383 } 384 385 386 static int ccmp_encrypt_skb(struct ieee80211_tx_data *tx, struct sk_buff *skb) 387 { 388 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data; 389 struct ieee80211_key *key = tx->key; 390 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb); 391 int hdrlen, len, tail; 392 u8 *pos, *pn; 393 int i; 394 395 if (info->control.hw_key && 396 !(info->control.hw_key->flags & IEEE80211_KEY_FLAG_GENERATE_IV)) { 397 /* 398 * hwaccel has no need for preallocated room for CCMP 399 * header or MIC fields 400 */ 401 return 0; 402 } 403 404 hdrlen = ieee80211_hdrlen(hdr->frame_control); 405 len = skb->len - hdrlen; 406 407 if (info->control.hw_key) 408 tail = 0; 409 else 410 tail = CCMP_MIC_LEN; 411 412 if (WARN_ON(skb_tailroom(skb) < tail || 413 skb_headroom(skb) < CCMP_HDR_LEN)) 414 return -1; 415 416 pos = skb_push(skb, CCMP_HDR_LEN); 417 memmove(pos, pos + CCMP_HDR_LEN, hdrlen); 418 hdr = (struct ieee80211_hdr *) pos; 419 pos += hdrlen; 420 421 /* PN = PN + 1 */ 422 pn = key->u.ccmp.tx_pn; 423 424 for (i = CCMP_PN_LEN - 1; i >= 0; i--) { 425 pn[i]++; 426 if (pn[i]) 427 break; 428 } 429 430 ccmp_pn2hdr(pos, pn, key->conf.keyidx); 431 432 /* hwaccel - with software CCMP header */ 433 if (info->control.hw_key) 434 return 0; 435 436 pos += CCMP_HDR_LEN; 437 ccmp_special_blocks(skb, pn, key->u.ccmp.tx_crypto_buf, 0); 438 ieee80211_aes_ccm_encrypt(key->u.ccmp.tfm, key->u.ccmp.tx_crypto_buf, pos, len, 439 pos, skb_put(skb, CCMP_MIC_LEN)); 440 441 return 0; 442 } 443 444 445 ieee80211_tx_result 446 ieee80211_crypto_ccmp_encrypt(struct ieee80211_tx_data *tx) 447 { 448 struct sk_buff *skb = tx->skb; 449 450 ieee80211_tx_set_protected(tx); 451 452 do { 453 if (ccmp_encrypt_skb(tx, skb) < 0) 454 return TX_DROP; 455 } while ((skb = skb->next)); 456 457 return TX_CONTINUE; 458 } 459 460 461 ieee80211_rx_result 462 ieee80211_crypto_ccmp_decrypt(struct ieee80211_rx_data *rx) 463 { 464 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data; 465 int hdrlen; 466 struct ieee80211_key *key = rx->key; 467 struct sk_buff *skb = rx->skb; 468 struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb); 469 u8 pn[CCMP_PN_LEN]; 470 int data_len; 471 int queue; 472 473 hdrlen = ieee80211_hdrlen(hdr->frame_control); 474 475 if (!ieee80211_is_data(hdr->frame_control) && 476 !ieee80211_is_robust_mgmt_frame(hdr)) 477 return RX_CONTINUE; 478 479 data_len = skb->len - hdrlen - CCMP_HDR_LEN - CCMP_MIC_LEN; 480 if (!rx->sta || data_len < 0) 481 return RX_DROP_UNUSABLE; 482 483 ccmp_hdr2pn(pn, skb->data + hdrlen); 484 485 queue = ieee80211_is_mgmt(hdr->frame_control) ? 486 NUM_RX_DATA_QUEUES : rx->queue; 487 488 if (memcmp(pn, key->u.ccmp.rx_pn[queue], CCMP_PN_LEN) <= 0) { 489 key->u.ccmp.replays++; 490 return RX_DROP_UNUSABLE; 491 } 492 493 if (!(status->flag & RX_FLAG_DECRYPTED)) { 494 /* hardware didn't decrypt/verify MIC */ 495 ccmp_special_blocks(skb, pn, key->u.ccmp.rx_crypto_buf, 1); 496 497 if (ieee80211_aes_ccm_decrypt( 498 key->u.ccmp.tfm, key->u.ccmp.rx_crypto_buf, 499 skb->data + hdrlen + CCMP_HDR_LEN, data_len, 500 skb->data + skb->len - CCMP_MIC_LEN, 501 skb->data + hdrlen + CCMP_HDR_LEN)) 502 return RX_DROP_UNUSABLE; 503 } 504 505 memcpy(key->u.ccmp.rx_pn[queue], pn, CCMP_PN_LEN); 506 507 /* Remove CCMP header and MIC */ 508 skb_trim(skb, skb->len - CCMP_MIC_LEN); 509 memmove(skb->data + CCMP_HDR_LEN, skb->data, hdrlen); 510 skb_pull(skb, CCMP_HDR_LEN); 511 512 return RX_CONTINUE; 513 } 514 515 516 static void bip_aad(struct sk_buff *skb, u8 *aad) 517 { 518 /* BIP AAD: FC(masked) || A1 || A2 || A3 */ 519 520 /* FC type/subtype */ 521 aad[0] = skb->data[0]; 522 /* Mask FC Retry, PwrMgt, MoreData flags to zero */ 523 aad[1] = skb->data[1] & ~(BIT(4) | BIT(5) | BIT(6)); 524 /* A1 || A2 || A3 */ 525 memcpy(aad + 2, skb->data + 4, 3 * ETH_ALEN); 526 } 527 528 529 static inline void bip_ipn_swap(u8 *d, const u8 *s) 530 { 531 *d++ = s[5]; 532 *d++ = s[4]; 533 *d++ = s[3]; 534 *d++ = s[2]; 535 *d++ = s[1]; 536 *d = s[0]; 537 } 538 539 540 ieee80211_tx_result 541 ieee80211_crypto_aes_cmac_encrypt(struct ieee80211_tx_data *tx) 542 { 543 struct sk_buff *skb = tx->skb; 544 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb); 545 struct ieee80211_key *key = tx->key; 546 struct ieee80211_mmie *mmie; 547 u8 *pn, aad[20]; 548 int i; 549 550 if (info->control.hw_key) 551 return 0; 552 553 if (WARN_ON(skb_tailroom(skb) < sizeof(*mmie))) 554 return TX_DROP; 555 556 mmie = (struct ieee80211_mmie *) skb_put(skb, sizeof(*mmie)); 557 mmie->element_id = WLAN_EID_MMIE; 558 mmie->length = sizeof(*mmie) - 2; 559 mmie->key_id = cpu_to_le16(key->conf.keyidx); 560 561 /* PN = PN + 1 */ 562 pn = key->u.aes_cmac.tx_pn; 563 564 for (i = sizeof(key->u.aes_cmac.tx_pn) - 1; i >= 0; i--) { 565 pn[i]++; 566 if (pn[i]) 567 break; 568 } 569 bip_ipn_swap(mmie->sequence_number, pn); 570 571 bip_aad(skb, aad); 572 573 /* 574 * MIC = AES-128-CMAC(IGTK, AAD || Management Frame Body || MMIE, 64) 575 */ 576 ieee80211_aes_cmac(key->u.aes_cmac.tfm, key->u.aes_cmac.tx_crypto_buf, 577 aad, skb->data + 24, skb->len - 24, mmie->mic); 578 579 return TX_CONTINUE; 580 } 581 582 583 ieee80211_rx_result 584 ieee80211_crypto_aes_cmac_decrypt(struct ieee80211_rx_data *rx) 585 { 586 struct sk_buff *skb = rx->skb; 587 struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb); 588 struct ieee80211_key *key = rx->key; 589 struct ieee80211_mmie *mmie; 590 u8 aad[20], mic[8], ipn[6]; 591 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data; 592 593 if (!ieee80211_is_mgmt(hdr->frame_control)) 594 return RX_CONTINUE; 595 596 if (skb->len < 24 + sizeof(*mmie)) 597 return RX_DROP_UNUSABLE; 598 599 mmie = (struct ieee80211_mmie *) 600 (skb->data + skb->len - sizeof(*mmie)); 601 if (mmie->element_id != WLAN_EID_MMIE || 602 mmie->length != sizeof(*mmie) - 2) 603 return RX_DROP_UNUSABLE; /* Invalid MMIE */ 604 605 bip_ipn_swap(ipn, mmie->sequence_number); 606 607 if (memcmp(ipn, key->u.aes_cmac.rx_pn, 6) <= 0) { 608 key->u.aes_cmac.replays++; 609 return RX_DROP_UNUSABLE; 610 } 611 612 if (!(status->flag & RX_FLAG_DECRYPTED)) { 613 /* hardware didn't decrypt/verify MIC */ 614 bip_aad(skb, aad); 615 ieee80211_aes_cmac(key->u.aes_cmac.tfm, 616 key->u.aes_cmac.rx_crypto_buf, aad, 617 skb->data + 24, skb->len - 24, mic); 618 if (memcmp(mic, mmie->mic, sizeof(mmie->mic)) != 0) { 619 key->u.aes_cmac.icverrors++; 620 return RX_DROP_UNUSABLE; 621 } 622 } 623 624 memcpy(key->u.aes_cmac.rx_pn, ipn, 6); 625 626 /* Remove MMIE */ 627 skb_trim(skb, skb->len - sizeof(*mmie)); 628 629 return RX_CONTINUE; 630 } 631