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 !(tx->flags & IEEE80211_TX_FRAGMENTED) && 57 !(tx->key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_MMIC)) { 58 /* hwaccel - with no need for SW-generated MMIC */ 59 return TX_CONTINUE; 60 } 61 62 tail = MICHAEL_MIC_LEN; 63 if (!info->control.hw_key) 64 tail += TKIP_ICV_LEN; 65 66 if (WARN_ON(skb_tailroom(skb) < tail || 67 skb_headroom(skb) < TKIP_IV_LEN)) 68 return TX_DROP; 69 70 key = &tx->key->conf.key[NL80211_TKIP_DATA_OFFSET_TX_MIC_KEY]; 71 mic = skb_put(skb, MICHAEL_MIC_LEN); 72 michael_mic(key, hdr, data, data_len, mic); 73 if (unlikely(info->flags & IEEE80211_TX_INTFL_TKIP_MIC_FAILURE)) 74 mic[0]++; 75 76 return TX_CONTINUE; 77 } 78 79 80 ieee80211_rx_result 81 ieee80211_rx_h_michael_mic_verify(struct ieee80211_rx_data *rx) 82 { 83 u8 *data, *key = NULL; 84 size_t data_len; 85 unsigned int hdrlen; 86 u8 mic[MICHAEL_MIC_LEN]; 87 struct sk_buff *skb = rx->skb; 88 struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb); 89 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data; 90 91 /* 92 * it makes no sense to check for MIC errors on anything other 93 * than data frames. 94 */ 95 if (!ieee80211_is_data_present(hdr->frame_control)) 96 return RX_CONTINUE; 97 98 /* 99 * No way to verify the MIC if the hardware stripped it or 100 * the IV with the key index. In this case we have solely rely 101 * on the driver to set RX_FLAG_MMIC_ERROR in the event of a 102 * MIC failure report. 103 */ 104 if (status->flag & (RX_FLAG_MMIC_STRIPPED | RX_FLAG_IV_STRIPPED)) { 105 if (status->flag & RX_FLAG_MMIC_ERROR) 106 goto mic_fail; 107 108 if (!(status->flag & RX_FLAG_IV_STRIPPED)) 109 goto update_iv; 110 111 return RX_CONTINUE; 112 } 113 114 /* 115 * Some hardware seems to generate Michael MIC failure reports; even 116 * though, the frame was not encrypted with TKIP and therefore has no 117 * MIC. Ignore the flag them to avoid triggering countermeasures. 118 */ 119 if (!rx->key || rx->key->conf.cipher != WLAN_CIPHER_SUITE_TKIP || 120 !(status->flag & RX_FLAG_DECRYPTED)) 121 return RX_CONTINUE; 122 123 if (rx->sdata->vif.type == NL80211_IFTYPE_AP && rx->key->conf.keyidx) { 124 /* 125 * APs with pairwise keys should never receive Michael MIC 126 * errors for non-zero keyidx because these are reserved for 127 * group keys and only the AP is sending real multicast 128 * frames in the BSS. ( 129 */ 130 return RX_DROP_UNUSABLE; 131 } 132 133 if (status->flag & RX_FLAG_MMIC_ERROR) 134 goto mic_fail; 135 136 hdrlen = ieee80211_hdrlen(hdr->frame_control); 137 if (skb->len < hdrlen + MICHAEL_MIC_LEN) 138 return RX_DROP_UNUSABLE; 139 140 data = skb->data + hdrlen; 141 data_len = skb->len - hdrlen - MICHAEL_MIC_LEN; 142 key = &rx->key->conf.key[NL80211_TKIP_DATA_OFFSET_RX_MIC_KEY]; 143 michael_mic(key, hdr, data, data_len, mic); 144 if (memcmp(mic, data + data_len, MICHAEL_MIC_LEN) != 0) 145 goto mic_fail; 146 147 /* remove Michael MIC from payload */ 148 skb_trim(skb, skb->len - MICHAEL_MIC_LEN); 149 150 update_iv: 151 /* update IV in key information to be able to detect replays */ 152 rx->key->u.tkip.rx[rx->security_idx].iv32 = rx->tkip_iv32; 153 rx->key->u.tkip.rx[rx->security_idx].iv16 = rx->tkip_iv16; 154 155 return RX_CONTINUE; 156 157 mic_fail: 158 /* 159 * In some cases the key can be unset - e.g. a multicast packet, in 160 * a driver that supports HW encryption. Send up the key idx only if 161 * the key is set. 162 */ 163 mac80211_ev_michael_mic_failure(rx->sdata, 164 rx->key ? rx->key->conf.keyidx : -1, 165 (void *) skb->data, NULL, GFP_ATOMIC); 166 return RX_DROP_UNUSABLE; 167 } 168 169 170 static int tkip_encrypt_skb(struct ieee80211_tx_data *tx, struct sk_buff *skb) 171 { 172 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data; 173 struct ieee80211_key *key = tx->key; 174 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb); 175 unsigned long flags; 176 unsigned int hdrlen; 177 int len, tail; 178 u8 *pos; 179 180 if (info->control.hw_key && 181 !(info->control.hw_key->flags & IEEE80211_KEY_FLAG_GENERATE_IV)) { 182 /* hwaccel - with no need for software-generated IV */ 183 return 0; 184 } 185 186 hdrlen = ieee80211_hdrlen(hdr->frame_control); 187 len = skb->len - hdrlen; 188 189 if (info->control.hw_key) 190 tail = 0; 191 else 192 tail = TKIP_ICV_LEN; 193 194 if (WARN_ON(skb_tailroom(skb) < tail || 195 skb_headroom(skb) < TKIP_IV_LEN)) 196 return -1; 197 198 pos = skb_push(skb, TKIP_IV_LEN); 199 memmove(pos, pos + TKIP_IV_LEN, hdrlen); 200 pos += hdrlen; 201 202 /* Increase IV for the frame */ 203 spin_lock_irqsave(&key->u.tkip.txlock, flags); 204 key->u.tkip.tx.iv16++; 205 if (key->u.tkip.tx.iv16 == 0) 206 key->u.tkip.tx.iv32++; 207 pos = ieee80211_tkip_add_iv(pos, key); 208 spin_unlock_irqrestore(&key->u.tkip.txlock, flags); 209 210 /* hwaccel - with software IV */ 211 if (info->control.hw_key) 212 return 0; 213 214 /* Add room for ICV */ 215 skb_put(skb, TKIP_ICV_LEN); 216 217 return ieee80211_tkip_encrypt_data(tx->local->wep_tx_tfm, 218 key, skb, pos, len); 219 } 220 221 222 ieee80211_tx_result 223 ieee80211_crypto_tkip_encrypt(struct ieee80211_tx_data *tx) 224 { 225 struct sk_buff *skb = tx->skb; 226 227 ieee80211_tx_set_protected(tx); 228 229 do { 230 if (tkip_encrypt_skb(tx, skb) < 0) 231 return TX_DROP; 232 } while ((skb = skb->next)); 233 234 return TX_CONTINUE; 235 } 236 237 238 ieee80211_rx_result 239 ieee80211_crypto_tkip_decrypt(struct ieee80211_rx_data *rx) 240 { 241 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) rx->skb->data; 242 int hdrlen, res, hwaccel = 0; 243 struct ieee80211_key *key = rx->key; 244 struct sk_buff *skb = rx->skb; 245 struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb); 246 247 hdrlen = ieee80211_hdrlen(hdr->frame_control); 248 249 if (!ieee80211_is_data(hdr->frame_control)) 250 return RX_CONTINUE; 251 252 if (!rx->sta || skb->len - hdrlen < 12) 253 return RX_DROP_UNUSABLE; 254 255 /* 256 * Let TKIP code verify IV, but skip decryption. 257 * In the case where hardware checks the IV as well, 258 * we don't even get here, see ieee80211_rx_h_decrypt() 259 */ 260 if (status->flag & RX_FLAG_DECRYPTED) 261 hwaccel = 1; 262 263 res = ieee80211_tkip_decrypt_data(rx->local->wep_rx_tfm, 264 key, skb->data + hdrlen, 265 skb->len - hdrlen, rx->sta->sta.addr, 266 hdr->addr1, hwaccel, rx->security_idx, 267 &rx->tkip_iv32, 268 &rx->tkip_iv16); 269 if (res != TKIP_DECRYPT_OK) 270 return RX_DROP_UNUSABLE; 271 272 /* Trim ICV */ 273 skb_trim(skb, skb->len - TKIP_ICV_LEN); 274 275 /* Remove IV */ 276 memmove(skb->data + TKIP_IV_LEN, skb->data, hdrlen); 277 skb_pull(skb, TKIP_IV_LEN); 278 279 return RX_CONTINUE; 280 } 281 282 283 static void ccmp_special_blocks(struct sk_buff *skb, u8 *pn, u8 *scratch, 284 int encrypted) 285 { 286 __le16 mask_fc; 287 int a4_included, mgmt; 288 u8 qos_tid; 289 u8 *b_0, *aad; 290 u16 data_len, len_a; 291 unsigned int hdrlen; 292 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data; 293 294 memset(scratch, 0, 6 * AES_BLOCK_SIZE); 295 296 b_0 = scratch + 3 * AES_BLOCK_SIZE; 297 aad = scratch + 4 * AES_BLOCK_SIZE; 298 299 /* 300 * Mask FC: zero subtype b4 b5 b6 (if not mgmt) 301 * Retry, PwrMgt, MoreData; set Protected 302 */ 303 mgmt = ieee80211_is_mgmt(hdr->frame_control); 304 mask_fc = hdr->frame_control; 305 mask_fc &= ~cpu_to_le16(IEEE80211_FCTL_RETRY | 306 IEEE80211_FCTL_PM | IEEE80211_FCTL_MOREDATA); 307 if (!mgmt) 308 mask_fc &= ~cpu_to_le16(0x0070); 309 mask_fc |= cpu_to_le16(IEEE80211_FCTL_PROTECTED); 310 311 hdrlen = ieee80211_hdrlen(hdr->frame_control); 312 len_a = hdrlen - 2; 313 a4_included = ieee80211_has_a4(hdr->frame_control); 314 315 if (ieee80211_is_data_qos(hdr->frame_control)) 316 qos_tid = *ieee80211_get_qos_ctl(hdr) & IEEE80211_QOS_CTL_TID_MASK; 317 else 318 qos_tid = 0; 319 320 data_len = skb->len - hdrlen - CCMP_HDR_LEN; 321 if (encrypted) 322 data_len -= CCMP_MIC_LEN; 323 324 /* First block, b_0 */ 325 b_0[0] = 0x59; /* flags: Adata: 1, M: 011, L: 001 */ 326 /* Nonce: Nonce Flags | A2 | PN 327 * Nonce Flags: Priority (b0..b3) | Management (b4) | Reserved (b5..b7) 328 */ 329 b_0[1] = qos_tid | (mgmt << 4); 330 memcpy(&b_0[2], hdr->addr2, ETH_ALEN); 331 memcpy(&b_0[8], pn, CCMP_PN_LEN); 332 /* l(m) */ 333 put_unaligned_be16(data_len, &b_0[14]); 334 335 /* AAD (extra authenticate-only data) / masked 802.11 header 336 * FC | A1 | A2 | A3 | SC | [A4] | [QC] */ 337 put_unaligned_be16(len_a, &aad[0]); 338 put_unaligned(mask_fc, (__le16 *)&aad[2]); 339 memcpy(&aad[4], &hdr->addr1, 3 * ETH_ALEN); 340 341 /* Mask Seq#, leave Frag# */ 342 aad[22] = *((u8 *) &hdr->seq_ctrl) & 0x0f; 343 aad[23] = 0; 344 345 if (a4_included) { 346 memcpy(&aad[24], hdr->addr4, ETH_ALEN); 347 aad[30] = qos_tid; 348 aad[31] = 0; 349 } else { 350 memset(&aad[24], 0, ETH_ALEN + IEEE80211_QOS_CTL_LEN); 351 aad[24] = qos_tid; 352 } 353 } 354 355 356 static inline void ccmp_pn2hdr(u8 *hdr, u8 *pn, int key_id) 357 { 358 hdr[0] = pn[5]; 359 hdr[1] = pn[4]; 360 hdr[2] = 0; 361 hdr[3] = 0x20 | (key_id << 6); 362 hdr[4] = pn[3]; 363 hdr[5] = pn[2]; 364 hdr[6] = pn[1]; 365 hdr[7] = pn[0]; 366 } 367 368 369 static inline void ccmp_hdr2pn(u8 *pn, u8 *hdr) 370 { 371 pn[0] = hdr[7]; 372 pn[1] = hdr[6]; 373 pn[2] = hdr[5]; 374 pn[3] = hdr[4]; 375 pn[4] = hdr[1]; 376 pn[5] = hdr[0]; 377 } 378 379 380 static int ccmp_encrypt_skb(struct ieee80211_tx_data *tx, struct sk_buff *skb) 381 { 382 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data; 383 struct ieee80211_key *key = tx->key; 384 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb); 385 int hdrlen, len, tail; 386 u8 *pos; 387 u8 pn[6]; 388 u64 pn64; 389 u8 scratch[6 * AES_BLOCK_SIZE]; 390 391 if (info->control.hw_key && 392 !(info->control.hw_key->flags & IEEE80211_KEY_FLAG_GENERATE_IV)) { 393 /* 394 * hwaccel has no need for preallocated room for CCMP 395 * header or MIC fields 396 */ 397 return 0; 398 } 399 400 hdrlen = ieee80211_hdrlen(hdr->frame_control); 401 len = skb->len - hdrlen; 402 403 if (info->control.hw_key) 404 tail = 0; 405 else 406 tail = CCMP_MIC_LEN; 407 408 if (WARN_ON(skb_tailroom(skb) < tail || 409 skb_headroom(skb) < CCMP_HDR_LEN)) 410 return -1; 411 412 pos = skb_push(skb, CCMP_HDR_LEN); 413 memmove(pos, pos + CCMP_HDR_LEN, hdrlen); 414 hdr = (struct ieee80211_hdr *) pos; 415 pos += hdrlen; 416 417 pn64 = atomic64_inc_return(&key->u.ccmp.tx_pn); 418 419 pn[5] = pn64; 420 pn[4] = pn64 >> 8; 421 pn[3] = pn64 >> 16; 422 pn[2] = pn64 >> 24; 423 pn[1] = pn64 >> 32; 424 pn[0] = pn64 >> 40; 425 426 ccmp_pn2hdr(pos, pn, key->conf.keyidx); 427 428 /* hwaccel - with software CCMP header */ 429 if (info->control.hw_key) 430 return 0; 431 432 pos += CCMP_HDR_LEN; 433 ccmp_special_blocks(skb, pn, scratch, 0); 434 ieee80211_aes_ccm_encrypt(key->u.ccmp.tfm, scratch, pos, len, 435 pos, skb_put(skb, CCMP_MIC_LEN)); 436 437 return 0; 438 } 439 440 441 ieee80211_tx_result 442 ieee80211_crypto_ccmp_encrypt(struct ieee80211_tx_data *tx) 443 { 444 struct sk_buff *skb = tx->skb; 445 446 ieee80211_tx_set_protected(tx); 447 448 do { 449 if (ccmp_encrypt_skb(tx, skb) < 0) 450 return TX_DROP; 451 } while ((skb = skb->next)); 452 453 return TX_CONTINUE; 454 } 455 456 457 ieee80211_rx_result 458 ieee80211_crypto_ccmp_decrypt(struct ieee80211_rx_data *rx) 459 { 460 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data; 461 int hdrlen; 462 struct ieee80211_key *key = rx->key; 463 struct sk_buff *skb = rx->skb; 464 struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb); 465 u8 pn[CCMP_PN_LEN]; 466 int data_len; 467 int queue; 468 469 hdrlen = ieee80211_hdrlen(hdr->frame_control); 470 471 if (!ieee80211_is_data(hdr->frame_control) && 472 !ieee80211_is_robust_mgmt_frame(hdr)) 473 return RX_CONTINUE; 474 475 data_len = skb->len - hdrlen - CCMP_HDR_LEN - CCMP_MIC_LEN; 476 if (!rx->sta || data_len < 0) 477 return RX_DROP_UNUSABLE; 478 479 ccmp_hdr2pn(pn, skb->data + hdrlen); 480 481 queue = rx->security_idx; 482 483 if (memcmp(pn, key->u.ccmp.rx_pn[queue], CCMP_PN_LEN) <= 0) { 484 key->u.ccmp.replays++; 485 return RX_DROP_UNUSABLE; 486 } 487 488 if (!(status->flag & RX_FLAG_DECRYPTED)) { 489 u8 scratch[6 * AES_BLOCK_SIZE]; 490 /* hardware didn't decrypt/verify MIC */ 491 ccmp_special_blocks(skb, pn, scratch, 1); 492 493 if (ieee80211_aes_ccm_decrypt( 494 key->u.ccmp.tfm, scratch, 495 skb->data + hdrlen + CCMP_HDR_LEN, data_len, 496 skb->data + skb->len - CCMP_MIC_LEN, 497 skb->data + hdrlen + CCMP_HDR_LEN)) 498 return RX_DROP_UNUSABLE; 499 } 500 501 memcpy(key->u.ccmp.rx_pn[queue], pn, CCMP_PN_LEN); 502 503 /* Remove CCMP header and MIC */ 504 skb_trim(skb, skb->len - CCMP_MIC_LEN); 505 memmove(skb->data + CCMP_HDR_LEN, skb->data, hdrlen); 506 skb_pull(skb, CCMP_HDR_LEN); 507 508 return RX_CONTINUE; 509 } 510 511 512 static void bip_aad(struct sk_buff *skb, u8 *aad) 513 { 514 /* BIP AAD: FC(masked) || A1 || A2 || A3 */ 515 516 /* FC type/subtype */ 517 aad[0] = skb->data[0]; 518 /* Mask FC Retry, PwrMgt, MoreData flags to zero */ 519 aad[1] = skb->data[1] & ~(BIT(4) | BIT(5) | BIT(6)); 520 /* A1 || A2 || A3 */ 521 memcpy(aad + 2, skb->data + 4, 3 * ETH_ALEN); 522 } 523 524 525 static inline void bip_ipn_set64(u8 *d, u64 pn) 526 { 527 *d++ = pn; 528 *d++ = pn >> 8; 529 *d++ = pn >> 16; 530 *d++ = pn >> 24; 531 *d++ = pn >> 32; 532 *d = pn >> 40; 533 } 534 535 static inline void bip_ipn_swap(u8 *d, const u8 *s) 536 { 537 *d++ = s[5]; 538 *d++ = s[4]; 539 *d++ = s[3]; 540 *d++ = s[2]; 541 *d++ = s[1]; 542 *d = s[0]; 543 } 544 545 546 ieee80211_tx_result 547 ieee80211_crypto_aes_cmac_encrypt(struct ieee80211_tx_data *tx) 548 { 549 struct sk_buff *skb = tx->skb; 550 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb); 551 struct ieee80211_key *key = tx->key; 552 struct ieee80211_mmie *mmie; 553 u8 aad[20]; 554 u64 pn64; 555 556 if (info->control.hw_key) 557 return 0; 558 559 if (WARN_ON(skb_tailroom(skb) < sizeof(*mmie))) 560 return TX_DROP; 561 562 mmie = (struct ieee80211_mmie *) skb_put(skb, sizeof(*mmie)); 563 mmie->element_id = WLAN_EID_MMIE; 564 mmie->length = sizeof(*mmie) - 2; 565 mmie->key_id = cpu_to_le16(key->conf.keyidx); 566 567 /* PN = PN + 1 */ 568 pn64 = atomic64_inc_return(&key->u.aes_cmac.tx_pn); 569 570 bip_ipn_set64(mmie->sequence_number, pn64); 571 572 bip_aad(skb, aad); 573 574 /* 575 * MIC = AES-128-CMAC(IGTK, AAD || Management Frame Body || MMIE, 64) 576 */ 577 ieee80211_aes_cmac(key->u.aes_cmac.tfm, aad, 578 skb->data + 24, skb->len - 24, mmie->mic); 579 580 return TX_CONTINUE; 581 } 582 583 584 ieee80211_rx_result 585 ieee80211_crypto_aes_cmac_decrypt(struct ieee80211_rx_data *rx) 586 { 587 struct sk_buff *skb = rx->skb; 588 struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb); 589 struct ieee80211_key *key = rx->key; 590 struct ieee80211_mmie *mmie; 591 u8 aad[20], mic[8], ipn[6]; 592 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data; 593 594 if (!ieee80211_is_mgmt(hdr->frame_control)) 595 return RX_CONTINUE; 596 597 if (skb->len < 24 + sizeof(*mmie)) 598 return RX_DROP_UNUSABLE; 599 600 mmie = (struct ieee80211_mmie *) 601 (skb->data + skb->len - sizeof(*mmie)); 602 if (mmie->element_id != WLAN_EID_MMIE || 603 mmie->length != sizeof(*mmie) - 2) 604 return RX_DROP_UNUSABLE; /* Invalid MMIE */ 605 606 bip_ipn_swap(ipn, mmie->sequence_number); 607 608 if (memcmp(ipn, key->u.aes_cmac.rx_pn, 6) <= 0) { 609 key->u.aes_cmac.replays++; 610 return RX_DROP_UNUSABLE; 611 } 612 613 if (!(status->flag & RX_FLAG_DECRYPTED)) { 614 /* hardware didn't decrypt/verify MIC */ 615 bip_aad(skb, aad); 616 ieee80211_aes_cmac(key->u.aes_cmac.tfm, 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