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/slab.h> 13 #include <linux/skbuff.h> 14 #include <linux/compiler.h> 15 #include <linux/ieee80211.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, key_offset; 30 size_t data_len; 31 unsigned int hdrlen; 32 struct ieee80211_hdr *hdr; 33 struct sk_buff *skb = tx->skb; 34 int authenticator; 35 int wpa_test = 0; 36 int tail; 37 38 hdr = (struct ieee80211_hdr *)skb->data; 39 if (!tx->key || tx->key->conf.alg != ALG_TKIP || skb->len < 24 || 40 !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 ((tx->key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE) && 51 !(tx->flags & IEEE80211_TX_FRAGMENTED) && 52 !(tx->key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_MMIC) && 53 !wpa_test) { 54 /* hwaccel - with no need for preallocated room for MMIC */ 55 return TX_CONTINUE; 56 } 57 58 tail = MICHAEL_MIC_LEN; 59 if (!(tx->key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE)) 60 tail += TKIP_ICV_LEN; 61 62 if (WARN_ON(skb_tailroom(skb) < tail || 63 skb_headroom(skb) < TKIP_IV_LEN)) 64 return TX_DROP; 65 66 #if 0 67 authenticator = fc & IEEE80211_FCTL_FROMDS; /* FIX */ 68 #else 69 authenticator = 1; 70 #endif 71 key_offset = authenticator ? 72 NL80211_TKIP_DATA_OFFSET_TX_MIC_KEY : 73 NL80211_TKIP_DATA_OFFSET_RX_MIC_KEY; 74 key = &tx->key->conf.key[key_offset]; 75 mic = skb_put(skb, MICHAEL_MIC_LEN); 76 michael_mic(key, hdr, data, data_len, mic); 77 78 return TX_CONTINUE; 79 } 80 81 82 ieee80211_rx_result 83 ieee80211_rx_h_michael_mic_verify(struct ieee80211_rx_data *rx) 84 { 85 u8 *data, *key = NULL, key_offset; 86 size_t data_len; 87 unsigned int hdrlen; 88 u8 mic[MICHAEL_MIC_LEN]; 89 struct sk_buff *skb = rx->skb; 90 struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb); 91 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data; 92 int authenticator = 1, wpa_test = 0; 93 94 /* No way to verify the MIC if the hardware stripped it */ 95 if (status->flag & RX_FLAG_MMIC_STRIPPED) 96 return RX_CONTINUE; 97 98 if (!rx->key || rx->key->conf.alg != ALG_TKIP || 99 !ieee80211_has_protected(hdr->frame_control) || 100 !ieee80211_is_data_present(hdr->frame_control)) 101 return RX_CONTINUE; 102 103 hdrlen = ieee80211_hdrlen(hdr->frame_control); 104 if (skb->len < hdrlen + MICHAEL_MIC_LEN) 105 return RX_DROP_UNUSABLE; 106 107 data = skb->data + hdrlen; 108 data_len = skb->len - hdrlen - MICHAEL_MIC_LEN; 109 110 #if 0 111 authenticator = fc & IEEE80211_FCTL_TODS; /* FIX */ 112 #else 113 authenticator = 1; 114 #endif 115 key_offset = authenticator ? 116 NL80211_TKIP_DATA_OFFSET_RX_MIC_KEY : 117 NL80211_TKIP_DATA_OFFSET_TX_MIC_KEY; 118 key = &rx->key->conf.key[key_offset]; 119 michael_mic(key, hdr, data, data_len, mic); 120 if (memcmp(mic, data + data_len, MICHAEL_MIC_LEN) != 0 || wpa_test) { 121 if (!(rx->flags & IEEE80211_RX_RA_MATCH)) 122 return RX_DROP_UNUSABLE; 123 124 mac80211_ev_michael_mic_failure(rx->sdata, rx->key->conf.keyidx, 125 (void *) skb->data, NULL, 126 GFP_ATOMIC); 127 return RX_DROP_UNUSABLE; 128 } 129 130 /* remove Michael MIC from payload */ 131 skb_trim(skb, skb->len - MICHAEL_MIC_LEN); 132 133 /* update IV in key information to be able to detect replays */ 134 rx->key->u.tkip.rx[rx->queue].iv32 = rx->tkip_iv32; 135 rx->key->u.tkip.rx[rx->queue].iv16 = rx->tkip_iv16; 136 137 return RX_CONTINUE; 138 } 139 140 141 static int tkip_encrypt_skb(struct ieee80211_tx_data *tx, struct sk_buff *skb) 142 { 143 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data; 144 struct ieee80211_key *key = tx->key; 145 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb); 146 unsigned int hdrlen; 147 int len, tail; 148 u8 *pos; 149 150 if ((tx->key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE) && 151 !(tx->key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_IV)) { 152 /* hwaccel - with no need for preallocated room for IV/ICV */ 153 info->control.hw_key = &tx->key->conf; 154 return 0; 155 } 156 157 hdrlen = ieee80211_hdrlen(hdr->frame_control); 158 len = skb->len - hdrlen; 159 160 if (tx->key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE) 161 tail = 0; 162 else 163 tail = TKIP_ICV_LEN; 164 165 if (WARN_ON(skb_tailroom(skb) < tail || 166 skb_headroom(skb) < TKIP_IV_LEN)) 167 return -1; 168 169 pos = skb_push(skb, TKIP_IV_LEN); 170 memmove(pos, pos + TKIP_IV_LEN, hdrlen); 171 pos += hdrlen; 172 173 /* Increase IV for the frame */ 174 key->u.tkip.tx.iv16++; 175 if (key->u.tkip.tx.iv16 == 0) 176 key->u.tkip.tx.iv32++; 177 178 if (tx->key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE) { 179 /* hwaccel - with preallocated room for IV */ 180 ieee80211_tkip_add_iv(pos, key, key->u.tkip.tx.iv16); 181 182 info->control.hw_key = &tx->key->conf; 183 return 0; 184 } 185 186 /* Add room for ICV */ 187 skb_put(skb, TKIP_ICV_LEN); 188 189 hdr = (struct ieee80211_hdr *) skb->data; 190 ieee80211_tkip_encrypt_data(tx->local->wep_tx_tfm, 191 key, pos, len, hdr->addr2); 192 return 0; 193 } 194 195 196 ieee80211_tx_result 197 ieee80211_crypto_tkip_encrypt(struct ieee80211_tx_data *tx) 198 { 199 struct sk_buff *skb = tx->skb; 200 201 ieee80211_tx_set_protected(tx); 202 203 do { 204 if (tkip_encrypt_skb(tx, skb) < 0) 205 return TX_DROP; 206 } while ((skb = skb->next)); 207 208 return TX_CONTINUE; 209 } 210 211 212 ieee80211_rx_result 213 ieee80211_crypto_tkip_decrypt(struct ieee80211_rx_data *rx) 214 { 215 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) rx->skb->data; 216 int hdrlen, res, hwaccel = 0, wpa_test = 0; 217 struct ieee80211_key *key = rx->key; 218 struct sk_buff *skb = rx->skb; 219 struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb); 220 221 hdrlen = ieee80211_hdrlen(hdr->frame_control); 222 223 if (!ieee80211_is_data(hdr->frame_control)) 224 return RX_CONTINUE; 225 226 if (!rx->sta || skb->len - hdrlen < 12) 227 return RX_DROP_UNUSABLE; 228 229 if (status->flag & RX_FLAG_DECRYPTED) { 230 if (status->flag & RX_FLAG_IV_STRIPPED) { 231 /* 232 * Hardware took care of all processing, including 233 * replay protection, and stripped the ICV/IV so 234 * we cannot do any checks here. 235 */ 236 return RX_CONTINUE; 237 } 238 239 /* let TKIP code verify IV, but skip decryption */ 240 hwaccel = 1; 241 } 242 243 res = ieee80211_tkip_decrypt_data(rx->local->wep_rx_tfm, 244 key, skb->data + hdrlen, 245 skb->len - hdrlen, rx->sta->sta.addr, 246 hdr->addr1, hwaccel, rx->queue, 247 &rx->tkip_iv32, 248 &rx->tkip_iv16); 249 if (res != TKIP_DECRYPT_OK || wpa_test) 250 return RX_DROP_UNUSABLE; 251 252 /* Trim ICV */ 253 skb_trim(skb, skb->len - TKIP_ICV_LEN); 254 255 /* Remove IV */ 256 memmove(skb->data + TKIP_IV_LEN, skb->data, hdrlen); 257 skb_pull(skb, TKIP_IV_LEN); 258 259 return RX_CONTINUE; 260 } 261 262 263 static void ccmp_special_blocks(struct sk_buff *skb, u8 *pn, u8 *scratch, 264 int encrypted) 265 { 266 __le16 mask_fc; 267 int a4_included, mgmt; 268 u8 qos_tid; 269 u8 *b_0, *aad; 270 u16 data_len, len_a; 271 unsigned int hdrlen; 272 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data; 273 274 b_0 = scratch + 3 * AES_BLOCK_LEN; 275 aad = scratch + 4 * AES_BLOCK_LEN; 276 277 /* 278 * Mask FC: zero subtype b4 b5 b6 (if not mgmt) 279 * Retry, PwrMgt, MoreData; set Protected 280 */ 281 mgmt = ieee80211_is_mgmt(hdr->frame_control); 282 mask_fc = hdr->frame_control; 283 mask_fc &= ~cpu_to_le16(IEEE80211_FCTL_RETRY | 284 IEEE80211_FCTL_PM | IEEE80211_FCTL_MOREDATA); 285 if (!mgmt) 286 mask_fc &= ~cpu_to_le16(0x0070); 287 mask_fc |= cpu_to_le16(IEEE80211_FCTL_PROTECTED); 288 289 hdrlen = ieee80211_hdrlen(hdr->frame_control); 290 len_a = hdrlen - 2; 291 a4_included = ieee80211_has_a4(hdr->frame_control); 292 293 if (ieee80211_is_data_qos(hdr->frame_control)) 294 qos_tid = *ieee80211_get_qos_ctl(hdr) & IEEE80211_QOS_CTL_TID_MASK; 295 else 296 qos_tid = 0; 297 298 data_len = skb->len - hdrlen - CCMP_HDR_LEN; 299 if (encrypted) 300 data_len -= CCMP_MIC_LEN; 301 302 /* First block, b_0 */ 303 b_0[0] = 0x59; /* flags: Adata: 1, M: 011, L: 001 */ 304 /* Nonce: Nonce Flags | A2 | PN 305 * Nonce Flags: Priority (b0..b3) | Management (b4) | Reserved (b5..b7) 306 */ 307 b_0[1] = qos_tid | (mgmt << 4); 308 memcpy(&b_0[2], hdr->addr2, ETH_ALEN); 309 memcpy(&b_0[8], pn, CCMP_PN_LEN); 310 /* l(m) */ 311 put_unaligned_be16(data_len, &b_0[14]); 312 313 /* AAD (extra authenticate-only data) / masked 802.11 header 314 * FC | A1 | A2 | A3 | SC | [A4] | [QC] */ 315 put_unaligned_be16(len_a, &aad[0]); 316 put_unaligned(mask_fc, (__le16 *)&aad[2]); 317 memcpy(&aad[4], &hdr->addr1, 3 * ETH_ALEN); 318 319 /* Mask Seq#, leave Frag# */ 320 aad[22] = *((u8 *) &hdr->seq_ctrl) & 0x0f; 321 aad[23] = 0; 322 323 if (a4_included) { 324 memcpy(&aad[24], hdr->addr4, ETH_ALEN); 325 aad[30] = qos_tid; 326 aad[31] = 0; 327 } else { 328 memset(&aad[24], 0, ETH_ALEN + IEEE80211_QOS_CTL_LEN); 329 aad[24] = qos_tid; 330 } 331 } 332 333 334 static inline void ccmp_pn2hdr(u8 *hdr, u8 *pn, int key_id) 335 { 336 hdr[0] = pn[5]; 337 hdr[1] = pn[4]; 338 hdr[2] = 0; 339 hdr[3] = 0x20 | (key_id << 6); 340 hdr[4] = pn[3]; 341 hdr[5] = pn[2]; 342 hdr[6] = pn[1]; 343 hdr[7] = pn[0]; 344 } 345 346 347 static inline void ccmp_hdr2pn(u8 *pn, u8 *hdr) 348 { 349 pn[0] = hdr[7]; 350 pn[1] = hdr[6]; 351 pn[2] = hdr[5]; 352 pn[3] = hdr[4]; 353 pn[4] = hdr[1]; 354 pn[5] = hdr[0]; 355 } 356 357 358 static int ccmp_encrypt_skb(struct ieee80211_tx_data *tx, struct sk_buff *skb) 359 { 360 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data; 361 struct ieee80211_key *key = tx->key; 362 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb); 363 int hdrlen, len, tail; 364 u8 *pos, *pn; 365 int i; 366 bool skip_hw; 367 368 skip_hw = (tx->key->conf.flags & IEEE80211_KEY_FLAG_SW_MGMT) && 369 ieee80211_is_mgmt(hdr->frame_control); 370 371 if ((tx->key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE) && 372 !(tx->key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_IV) && 373 !skip_hw) { 374 /* hwaccel - with no need for preallocated room for CCMP 375 * header or MIC fields */ 376 info->control.hw_key = &tx->key->conf; 377 return 0; 378 } 379 380 hdrlen = ieee80211_hdrlen(hdr->frame_control); 381 len = skb->len - hdrlen; 382 383 if (key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE) 384 tail = 0; 385 else 386 tail = CCMP_MIC_LEN; 387 388 if (WARN_ON(skb_tailroom(skb) < tail || 389 skb_headroom(skb) < CCMP_HDR_LEN)) 390 return -1; 391 392 pos = skb_push(skb, CCMP_HDR_LEN); 393 memmove(pos, pos + CCMP_HDR_LEN, hdrlen); 394 hdr = (struct ieee80211_hdr *) pos; 395 pos += hdrlen; 396 397 /* PN = PN + 1 */ 398 pn = key->u.ccmp.tx_pn; 399 400 for (i = CCMP_PN_LEN - 1; i >= 0; i--) { 401 pn[i]++; 402 if (pn[i]) 403 break; 404 } 405 406 ccmp_pn2hdr(pos, pn, key->conf.keyidx); 407 408 if ((key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE) && !skip_hw) { 409 /* hwaccel - with preallocated room for CCMP header */ 410 info->control.hw_key = &tx->key->conf; 411 return 0; 412 } 413 414 pos += CCMP_HDR_LEN; 415 ccmp_special_blocks(skb, pn, key->u.ccmp.tx_crypto_buf, 0); 416 ieee80211_aes_ccm_encrypt(key->u.ccmp.tfm, key->u.ccmp.tx_crypto_buf, pos, len, 417 pos, skb_put(skb, CCMP_MIC_LEN)); 418 419 return 0; 420 } 421 422 423 ieee80211_tx_result 424 ieee80211_crypto_ccmp_encrypt(struct ieee80211_tx_data *tx) 425 { 426 struct sk_buff *skb = tx->skb; 427 428 ieee80211_tx_set_protected(tx); 429 430 do { 431 if (ccmp_encrypt_skb(tx, skb) < 0) 432 return TX_DROP; 433 } while ((skb = skb->next)); 434 435 return TX_CONTINUE; 436 } 437 438 439 ieee80211_rx_result 440 ieee80211_crypto_ccmp_decrypt(struct ieee80211_rx_data *rx) 441 { 442 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data; 443 int hdrlen; 444 struct ieee80211_key *key = rx->key; 445 struct sk_buff *skb = rx->skb; 446 struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb); 447 u8 pn[CCMP_PN_LEN]; 448 int data_len; 449 450 hdrlen = ieee80211_hdrlen(hdr->frame_control); 451 452 if (!ieee80211_is_data(hdr->frame_control) && 453 !ieee80211_is_robust_mgmt_frame(hdr)) 454 return RX_CONTINUE; 455 456 data_len = skb->len - hdrlen - CCMP_HDR_LEN - CCMP_MIC_LEN; 457 if (!rx->sta || data_len < 0) 458 return RX_DROP_UNUSABLE; 459 460 if ((status->flag & RX_FLAG_DECRYPTED) && 461 (status->flag & RX_FLAG_IV_STRIPPED)) 462 return RX_CONTINUE; 463 464 ccmp_hdr2pn(pn, skb->data + hdrlen); 465 466 if (memcmp(pn, key->u.ccmp.rx_pn[rx->queue], CCMP_PN_LEN) <= 0) { 467 key->u.ccmp.replays++; 468 return RX_DROP_UNUSABLE; 469 } 470 471 if (!(status->flag & RX_FLAG_DECRYPTED)) { 472 /* hardware didn't decrypt/verify MIC */ 473 ccmp_special_blocks(skb, pn, key->u.ccmp.rx_crypto_buf, 1); 474 475 if (ieee80211_aes_ccm_decrypt( 476 key->u.ccmp.tfm, key->u.ccmp.rx_crypto_buf, 477 skb->data + hdrlen + CCMP_HDR_LEN, data_len, 478 skb->data + skb->len - CCMP_MIC_LEN, 479 skb->data + hdrlen + CCMP_HDR_LEN)) 480 return RX_DROP_UNUSABLE; 481 } 482 483 memcpy(key->u.ccmp.rx_pn[rx->queue], pn, CCMP_PN_LEN); 484 485 /* Remove CCMP header and MIC */ 486 skb_trim(skb, skb->len - CCMP_MIC_LEN); 487 memmove(skb->data + CCMP_HDR_LEN, skb->data, hdrlen); 488 skb_pull(skb, CCMP_HDR_LEN); 489 490 return RX_CONTINUE; 491 } 492 493 494 static void bip_aad(struct sk_buff *skb, u8 *aad) 495 { 496 /* BIP AAD: FC(masked) || A1 || A2 || A3 */ 497 498 /* FC type/subtype */ 499 aad[0] = skb->data[0]; 500 /* Mask FC Retry, PwrMgt, MoreData flags to zero */ 501 aad[1] = skb->data[1] & ~(BIT(4) | BIT(5) | BIT(6)); 502 /* A1 || A2 || A3 */ 503 memcpy(aad + 2, skb->data + 4, 3 * ETH_ALEN); 504 } 505 506 507 static inline void bip_ipn_swap(u8 *d, const u8 *s) 508 { 509 *d++ = s[5]; 510 *d++ = s[4]; 511 *d++ = s[3]; 512 *d++ = s[2]; 513 *d++ = s[1]; 514 *d = s[0]; 515 } 516 517 518 ieee80211_tx_result 519 ieee80211_crypto_aes_cmac_encrypt(struct ieee80211_tx_data *tx) 520 { 521 struct sk_buff *skb = tx->skb; 522 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb); 523 struct ieee80211_key *key = tx->key; 524 struct ieee80211_mmie *mmie; 525 u8 *pn, aad[20]; 526 int i; 527 528 if (tx->key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE) { 529 /* hwaccel */ 530 info->control.hw_key = &tx->key->conf; 531 return 0; 532 } 533 534 if (WARN_ON(skb_tailroom(skb) < sizeof(*mmie))) 535 return TX_DROP; 536 537 mmie = (struct ieee80211_mmie *) skb_put(skb, sizeof(*mmie)); 538 mmie->element_id = WLAN_EID_MMIE; 539 mmie->length = sizeof(*mmie) - 2; 540 mmie->key_id = cpu_to_le16(key->conf.keyidx); 541 542 /* PN = PN + 1 */ 543 pn = key->u.aes_cmac.tx_pn; 544 545 for (i = sizeof(key->u.aes_cmac.tx_pn) - 1; i >= 0; i--) { 546 pn[i]++; 547 if (pn[i]) 548 break; 549 } 550 bip_ipn_swap(mmie->sequence_number, pn); 551 552 bip_aad(skb, aad); 553 554 /* 555 * MIC = AES-128-CMAC(IGTK, AAD || Management Frame Body || MMIE, 64) 556 */ 557 ieee80211_aes_cmac(key->u.aes_cmac.tfm, key->u.aes_cmac.tx_crypto_buf, 558 aad, skb->data + 24, skb->len - 24, mmie->mic); 559 560 return TX_CONTINUE; 561 } 562 563 564 ieee80211_rx_result 565 ieee80211_crypto_aes_cmac_decrypt(struct ieee80211_rx_data *rx) 566 { 567 struct sk_buff *skb = rx->skb; 568 struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb); 569 struct ieee80211_key *key = rx->key; 570 struct ieee80211_mmie *mmie; 571 u8 aad[20], mic[8], ipn[6]; 572 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data; 573 574 if (!ieee80211_is_mgmt(hdr->frame_control)) 575 return RX_CONTINUE; 576 577 if ((status->flag & RX_FLAG_DECRYPTED) && 578 (status->flag & RX_FLAG_IV_STRIPPED)) 579 return RX_CONTINUE; 580 581 if (skb->len < 24 + sizeof(*mmie)) 582 return RX_DROP_UNUSABLE; 583 584 mmie = (struct ieee80211_mmie *) 585 (skb->data + skb->len - sizeof(*mmie)); 586 if (mmie->element_id != WLAN_EID_MMIE || 587 mmie->length != sizeof(*mmie) - 2) 588 return RX_DROP_UNUSABLE; /* Invalid MMIE */ 589 590 bip_ipn_swap(ipn, mmie->sequence_number); 591 592 if (memcmp(ipn, key->u.aes_cmac.rx_pn, 6) <= 0) { 593 key->u.aes_cmac.replays++; 594 return RX_DROP_UNUSABLE; 595 } 596 597 if (!(status->flag & RX_FLAG_DECRYPTED)) { 598 /* hardware didn't decrypt/verify MIC */ 599 bip_aad(skb, aad); 600 ieee80211_aes_cmac(key->u.aes_cmac.tfm, 601 key->u.aes_cmac.rx_crypto_buf, aad, 602 skb->data + 24, skb->len - 24, mic); 603 if (memcmp(mic, mmie->mic, sizeof(mmie->mic)) != 0) { 604 key->u.aes_cmac.icverrors++; 605 return RX_DROP_UNUSABLE; 606 } 607 } 608 609 memcpy(key->u.aes_cmac.rx_pn, ipn, 6); 610 611 /* Remove MMIE */ 612 skb_trim(skb, skb->len - sizeof(*mmie)); 613 614 return RX_CONTINUE; 615 } 616