1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Copyright 2002-2004, Instant802 Networks, Inc.
4 * Copyright 2008, Jouni Malinen <[email protected]>
5 * Copyright (C) 2016-2017 Intel Deutschland GmbH
6 * Copyright (C) 2020-2023 Intel Corporation
7 */
8
9 #include <linux/netdevice.h>
10 #include <linux/types.h>
11 #include <linux/skbuff.h>
12 #include <linux/compiler.h>
13 #include <linux/ieee80211.h>
14 #include <linux/gfp.h>
15 #include <linux/unaligned.h>
16 #include <net/mac80211.h>
17 #include <crypto/aes.h>
18 #include <crypto/utils.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 "aes_gmac.h"
26 #include "aes_gcm.h"
27 #include "wpa.h"
28
29 ieee80211_tx_result
ieee80211_tx_h_michael_mic_add(struct ieee80211_tx_data * tx)30 ieee80211_tx_h_michael_mic_add(struct ieee80211_tx_data *tx)
31 {
32 u8 *data, *key, *mic;
33 size_t data_len;
34 unsigned int hdrlen;
35 struct ieee80211_hdr *hdr;
36 struct sk_buff *skb = tx->skb;
37 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
38 int tail;
39
40 hdr = (struct ieee80211_hdr *)skb->data;
41 if (!tx->key || tx->key->conf.cipher != WLAN_CIPHER_SUITE_TKIP ||
42 skb->len < 24 || !ieee80211_is_data_present(hdr->frame_control))
43 return TX_CONTINUE;
44
45 hdrlen = ieee80211_hdrlen(hdr->frame_control);
46 if (skb->len < hdrlen)
47 return TX_DROP;
48
49 data = skb->data + hdrlen;
50 data_len = skb->len - hdrlen;
51
52 if (unlikely(info->flags & IEEE80211_TX_INTFL_TKIP_MIC_FAILURE)) {
53 /* Need to use software crypto for the test */
54 info->control.hw_key = NULL;
55 }
56
57 if (info->control.hw_key &&
58 (info->flags & IEEE80211_TX_CTL_DONTFRAG ||
59 ieee80211_hw_check(&tx->local->hw, SUPPORTS_TX_FRAG)) &&
60 !(tx->key->conf.flags & (IEEE80211_KEY_FLAG_GENERATE_MMIC |
61 IEEE80211_KEY_FLAG_PUT_MIC_SPACE))) {
62 /* hwaccel - with no need for SW-generated MMIC or MIC space */
63 return TX_CONTINUE;
64 }
65
66 tail = MICHAEL_MIC_LEN;
67 if (!info->control.hw_key)
68 tail += IEEE80211_TKIP_ICV_LEN;
69
70 if (WARN(skb_tailroom(skb) < tail ||
71 skb_headroom(skb) < IEEE80211_TKIP_IV_LEN,
72 "mmic: not enough head/tail (%d/%d,%d/%d)\n",
73 skb_headroom(skb), IEEE80211_TKIP_IV_LEN,
74 skb_tailroom(skb), tail))
75 return TX_DROP;
76
77 mic = skb_put(skb, MICHAEL_MIC_LEN);
78
79 if (tx->key->conf.flags & IEEE80211_KEY_FLAG_PUT_MIC_SPACE) {
80 /* Zeroed MIC can help with debug */
81 memset(mic, 0, MICHAEL_MIC_LEN);
82 return TX_CONTINUE;
83 }
84
85 key = &tx->key->conf.key[NL80211_TKIP_DATA_OFFSET_TX_MIC_KEY];
86 michael_mic(key, hdr, data, data_len, mic);
87 if (unlikely(info->flags & IEEE80211_TX_INTFL_TKIP_MIC_FAILURE))
88 mic[0]++;
89
90 return TX_CONTINUE;
91 }
92
93
94 ieee80211_rx_result
ieee80211_rx_h_michael_mic_verify(struct ieee80211_rx_data * rx)95 ieee80211_rx_h_michael_mic_verify(struct ieee80211_rx_data *rx)
96 {
97 u8 *data, *key = NULL;
98 size_t data_len;
99 unsigned int hdrlen;
100 u8 mic[MICHAEL_MIC_LEN];
101 struct sk_buff *skb = rx->skb;
102 struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
103 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
104
105 /*
106 * it makes no sense to check for MIC errors on anything other
107 * than data frames.
108 */
109 if (!ieee80211_is_data_present(hdr->frame_control))
110 return RX_CONTINUE;
111
112 /*
113 * No way to verify the MIC if the hardware stripped it or
114 * the IV with the key index. In this case we have solely rely
115 * on the driver to set RX_FLAG_MMIC_ERROR in the event of a
116 * MIC failure report.
117 */
118 if (status->flag & (RX_FLAG_MMIC_STRIPPED | RX_FLAG_IV_STRIPPED)) {
119 if (status->flag & RX_FLAG_MMIC_ERROR)
120 goto mic_fail_no_key;
121
122 if (!(status->flag & RX_FLAG_IV_STRIPPED) && rx->key &&
123 rx->key->conf.cipher == WLAN_CIPHER_SUITE_TKIP)
124 goto update_iv;
125
126 return RX_CONTINUE;
127 }
128
129 /*
130 * Some hardware seems to generate Michael MIC failure reports; even
131 * though, the frame was not encrypted with TKIP and therefore has no
132 * MIC. Ignore the flag them to avoid triggering countermeasures.
133 */
134 if (!rx->key || rx->key->conf.cipher != WLAN_CIPHER_SUITE_TKIP ||
135 !(status->flag & RX_FLAG_DECRYPTED))
136 return RX_CONTINUE;
137
138 if (rx->sdata->vif.type == NL80211_IFTYPE_AP && rx->key->conf.keyidx) {
139 /*
140 * APs with pairwise keys should never receive Michael MIC
141 * errors for non-zero keyidx because these are reserved for
142 * group keys and only the AP is sending real multicast
143 * frames in the BSS.
144 */
145 return RX_DROP_U_AP_RX_GROUPCAST;
146 }
147
148 if (status->flag & RX_FLAG_MMIC_ERROR)
149 goto mic_fail;
150
151 hdrlen = ieee80211_hdrlen(hdr->frame_control);
152 if (skb->len < hdrlen + MICHAEL_MIC_LEN)
153 return RX_DROP_U_SHORT_MMIC;
154
155 if (skb_linearize(rx->skb))
156 return RX_DROP_U_OOM;
157 hdr = (void *)skb->data;
158
159 data = skb->data + hdrlen;
160 data_len = skb->len - hdrlen - MICHAEL_MIC_LEN;
161 key = &rx->key->conf.key[NL80211_TKIP_DATA_OFFSET_RX_MIC_KEY];
162 michael_mic(key, hdr, data, data_len, mic);
163 if (crypto_memneq(mic, data + data_len, MICHAEL_MIC_LEN))
164 goto mic_fail;
165
166 /* remove Michael MIC from payload */
167 skb_trim(skb, skb->len - MICHAEL_MIC_LEN);
168
169 update_iv:
170 /* update IV in key information to be able to detect replays */
171 rx->key->u.tkip.rx[rx->security_idx].iv32 = rx->tkip.iv32;
172 rx->key->u.tkip.rx[rx->security_idx].iv16 = rx->tkip.iv16;
173
174 return RX_CONTINUE;
175
176 mic_fail:
177 rx->key->u.tkip.mic_failures++;
178
179 mic_fail_no_key:
180 /*
181 * In some cases the key can be unset - e.g. a multicast packet, in
182 * a driver that supports HW encryption. Send up the key idx only if
183 * the key is set.
184 */
185 cfg80211_michael_mic_failure(rx->sdata->dev, hdr->addr2,
186 is_multicast_ether_addr(hdr->addr1) ?
187 NL80211_KEYTYPE_GROUP :
188 NL80211_KEYTYPE_PAIRWISE,
189 rx->key ? rx->key->conf.keyidx : -1,
190 NULL, GFP_ATOMIC);
191 return RX_DROP_U_MMIC_FAIL;
192 }
193
tkip_encrypt_skb(struct ieee80211_tx_data * tx,struct sk_buff * skb)194 static int tkip_encrypt_skb(struct ieee80211_tx_data *tx, struct sk_buff *skb)
195 {
196 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
197 struct ieee80211_key *key = tx->key;
198 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
199 unsigned int hdrlen;
200 int len, tail;
201 u64 pn;
202 u8 *pos;
203
204 if (info->control.hw_key &&
205 !(info->control.hw_key->flags & IEEE80211_KEY_FLAG_GENERATE_IV) &&
206 !(info->control.hw_key->flags & IEEE80211_KEY_FLAG_PUT_IV_SPACE)) {
207 /* hwaccel - with no need for software-generated IV */
208 return 0;
209 }
210
211 hdrlen = ieee80211_hdrlen(hdr->frame_control);
212 len = skb->len - hdrlen;
213
214 if (info->control.hw_key)
215 tail = 0;
216 else
217 tail = IEEE80211_TKIP_ICV_LEN;
218
219 if (WARN_ON(skb_tailroom(skb) < tail ||
220 skb_headroom(skb) < IEEE80211_TKIP_IV_LEN))
221 return -1;
222
223 pos = skb_push(skb, IEEE80211_TKIP_IV_LEN);
224 memmove(pos, pos + IEEE80211_TKIP_IV_LEN, hdrlen);
225 pos += hdrlen;
226
227 /* the HW only needs room for the IV, but not the actual IV */
228 if (info->control.hw_key &&
229 (info->control.hw_key->flags & IEEE80211_KEY_FLAG_PUT_IV_SPACE))
230 return 0;
231
232 /* Increase IV for the frame */
233 pn = atomic64_inc_return(&key->conf.tx_pn);
234 pos = ieee80211_tkip_add_iv(pos, &key->conf, pn);
235
236 /* hwaccel - with software IV */
237 if (info->control.hw_key)
238 return 0;
239
240 /* Add room for ICV */
241 skb_put(skb, IEEE80211_TKIP_ICV_LEN);
242
243 return ieee80211_tkip_encrypt_data(&tx->local->wep_tx_ctx,
244 key, skb, pos, len);
245 }
246
247
248 ieee80211_tx_result
ieee80211_crypto_tkip_encrypt(struct ieee80211_tx_data * tx)249 ieee80211_crypto_tkip_encrypt(struct ieee80211_tx_data *tx)
250 {
251 struct sk_buff *skb;
252
253 ieee80211_tx_set_protected(tx);
254
255 skb_queue_walk(&tx->skbs, skb) {
256 if (tkip_encrypt_skb(tx, skb) < 0)
257 return TX_DROP;
258 }
259
260 return TX_CONTINUE;
261 }
262
263
264 ieee80211_rx_result
ieee80211_crypto_tkip_decrypt(struct ieee80211_rx_data * rx)265 ieee80211_crypto_tkip_decrypt(struct ieee80211_rx_data *rx)
266 {
267 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) rx->skb->data;
268 int hdrlen, res, hwaccel = 0;
269 struct ieee80211_key *key = rx->key;
270 struct sk_buff *skb = rx->skb;
271 struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
272
273 hdrlen = ieee80211_hdrlen(hdr->frame_control);
274
275 if (!ieee80211_is_data(hdr->frame_control))
276 return RX_CONTINUE;
277
278 if (!rx->sta || skb->len - hdrlen < 12)
279 return RX_DROP_U_SHORT_TKIP;
280
281 /* it may be possible to optimize this a bit more */
282 if (skb_linearize(rx->skb))
283 return RX_DROP_U_OOM;
284 hdr = (void *)skb->data;
285
286 /*
287 * Let TKIP code verify IV, but skip decryption.
288 * In the case where hardware checks the IV as well,
289 * we don't even get here, see ieee80211_rx_h_decrypt()
290 */
291 if (status->flag & RX_FLAG_DECRYPTED)
292 hwaccel = 1;
293
294 res = ieee80211_tkip_decrypt_data(&rx->local->wep_rx_ctx,
295 key, skb->data + hdrlen,
296 skb->len - hdrlen, rx->sta->sta.addr,
297 hdr->addr1, hwaccel, rx->security_idx,
298 &rx->tkip.iv32,
299 &rx->tkip.iv16);
300 if (res != TKIP_DECRYPT_OK)
301 return RX_DROP_U_TKIP_FAIL;
302
303 /* Trim ICV */
304 if (!(status->flag & RX_FLAG_ICV_STRIPPED))
305 skb_trim(skb, skb->len - IEEE80211_TKIP_ICV_LEN);
306
307 /* Remove IV */
308 memmove(skb->data + IEEE80211_TKIP_IV_LEN, skb->data, hdrlen);
309 skb_pull(skb, IEEE80211_TKIP_IV_LEN);
310
311 return RX_CONTINUE;
312 }
313
314 /*
315 * Calculate AAD for CCMP/GCMP, returning qos_tid since we
316 * need that in CCMP also for b_0.
317 */
ccmp_gcmp_aad(struct sk_buff * skb,u8 * aad,bool spp_amsdu)318 static u8 ccmp_gcmp_aad(struct sk_buff *skb, u8 *aad, bool spp_amsdu)
319 {
320 struct ieee80211_hdr *hdr = (void *)skb->data;
321 __le16 mask_fc;
322 int a4_included, mgmt;
323 u8 qos_tid;
324 u16 len_a = 22;
325
326 /*
327 * Mask FC: zero subtype b4 b5 b6 (if not mgmt)
328 * Retry, PwrMgt, MoreData, Order (if Qos Data); set Protected
329 */
330 mgmt = ieee80211_is_mgmt(hdr->frame_control);
331 mask_fc = hdr->frame_control;
332 mask_fc &= ~cpu_to_le16(IEEE80211_FCTL_RETRY |
333 IEEE80211_FCTL_PM | IEEE80211_FCTL_MOREDATA);
334 if (!mgmt)
335 mask_fc &= ~cpu_to_le16(0x0070);
336 mask_fc |= cpu_to_le16(IEEE80211_FCTL_PROTECTED);
337
338 a4_included = ieee80211_has_a4(hdr->frame_control);
339 if (a4_included)
340 len_a += 6;
341
342 if (ieee80211_is_data_qos(hdr->frame_control)) {
343 qos_tid = *ieee80211_get_qos_ctl(hdr);
344
345 if (spp_amsdu)
346 qos_tid &= IEEE80211_QOS_CTL_TID_MASK |
347 IEEE80211_QOS_CTL_A_MSDU_PRESENT;
348 else
349 qos_tid &= IEEE80211_QOS_CTL_TID_MASK;
350
351 mask_fc &= ~cpu_to_le16(IEEE80211_FCTL_ORDER);
352 len_a += 2;
353 } else {
354 qos_tid = 0;
355 }
356
357 /* AAD (extra authenticate-only data) / masked 802.11 header
358 * FC | A1 | A2 | A3 | SC | [A4] | [QC] */
359 put_unaligned_be16(len_a, &aad[0]);
360 put_unaligned(mask_fc, (__le16 *)&aad[2]);
361 memcpy(&aad[4], &hdr->addrs, 3 * ETH_ALEN);
362
363 /* Mask Seq#, leave Frag# */
364 aad[22] = *((u8 *) &hdr->seq_ctrl) & 0x0f;
365 aad[23] = 0;
366
367 if (a4_included) {
368 memcpy(&aad[24], hdr->addr4, ETH_ALEN);
369 aad[30] = qos_tid;
370 aad[31] = 0;
371 } else {
372 memset(&aad[24], 0, ETH_ALEN + IEEE80211_QOS_CTL_LEN);
373 aad[24] = qos_tid;
374 }
375
376 return qos_tid;
377 }
378
ccmp_special_blocks(struct sk_buff * skb,u8 * pn,u8 * b_0,u8 * aad,bool spp_amsdu)379 static void ccmp_special_blocks(struct sk_buff *skb, u8 *pn, u8 *b_0, u8 *aad,
380 bool spp_amsdu)
381 {
382 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
383 u8 qos_tid = ccmp_gcmp_aad(skb, aad, spp_amsdu);
384
385 /* In CCM, the initial vectors (IV) used for CTR mode encryption and CBC
386 * mode authentication are not allowed to collide, yet both are derived
387 * from this vector b_0. We only set L := 1 here to indicate that the
388 * data size can be represented in (L+1) bytes. The CCM layer will take
389 * care of storing the data length in the top (L+1) bytes and setting
390 * and clearing the other bits as is required to derive the two IVs.
391 */
392 b_0[0] = 0x1;
393
394 /* Nonce: Nonce Flags | A2 | PN
395 * Nonce Flags: Priority (b0..b3) | Management (b4) | Reserved (b5..b7)
396 */
397 b_0[1] = qos_tid | (ieee80211_is_mgmt(hdr->frame_control) << 4);
398 memcpy(&b_0[2], hdr->addr2, ETH_ALEN);
399 memcpy(&b_0[8], pn, IEEE80211_CCMP_PN_LEN);
400 }
401
ccmp_pn2hdr(u8 * hdr,u8 * pn,int key_id)402 static inline void ccmp_pn2hdr(u8 *hdr, u8 *pn, int key_id)
403 {
404 hdr[0] = pn[5];
405 hdr[1] = pn[4];
406 hdr[2] = 0;
407 hdr[3] = 0x20 | (key_id << 6);
408 hdr[4] = pn[3];
409 hdr[5] = pn[2];
410 hdr[6] = pn[1];
411 hdr[7] = pn[0];
412 }
413
414
ccmp_hdr2pn(u8 * pn,u8 * hdr)415 static inline void ccmp_hdr2pn(u8 *pn, u8 *hdr)
416 {
417 pn[0] = hdr[7];
418 pn[1] = hdr[6];
419 pn[2] = hdr[5];
420 pn[3] = hdr[4];
421 pn[4] = hdr[1];
422 pn[5] = hdr[0];
423 }
424
425
ccmp_encrypt_skb(struct ieee80211_tx_data * tx,struct sk_buff * skb,unsigned int mic_len)426 static int ccmp_encrypt_skb(struct ieee80211_tx_data *tx, struct sk_buff *skb,
427 unsigned int mic_len)
428 {
429 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
430 struct ieee80211_key *key = tx->key;
431 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
432 int hdrlen, len, tail;
433 u8 *pos;
434 u8 pn[6];
435 u64 pn64;
436 u8 aad[CCM_AAD_LEN];
437 u8 b_0[AES_BLOCK_SIZE];
438
439 if (info->control.hw_key &&
440 !(info->control.hw_key->flags & IEEE80211_KEY_FLAG_GENERATE_IV) &&
441 !(info->control.hw_key->flags & IEEE80211_KEY_FLAG_PUT_IV_SPACE) &&
442 !((info->control.hw_key->flags &
443 IEEE80211_KEY_FLAG_GENERATE_IV_MGMT) &&
444 ieee80211_is_mgmt(hdr->frame_control))) {
445 /*
446 * hwaccel has no need for preallocated room for CCMP
447 * header or MIC fields
448 */
449 return 0;
450 }
451
452 hdrlen = ieee80211_hdrlen(hdr->frame_control);
453 len = skb->len - hdrlen;
454
455 if (info->control.hw_key)
456 tail = 0;
457 else
458 tail = mic_len;
459
460 if (WARN_ON(skb_tailroom(skb) < tail ||
461 skb_headroom(skb) < IEEE80211_CCMP_HDR_LEN))
462 return -1;
463
464 pos = skb_push(skb, IEEE80211_CCMP_HDR_LEN);
465 memmove(pos, pos + IEEE80211_CCMP_HDR_LEN, hdrlen);
466
467 /* the HW only needs room for the IV, but not the actual IV */
468 if (info->control.hw_key &&
469 (info->control.hw_key->flags & IEEE80211_KEY_FLAG_PUT_IV_SPACE))
470 return 0;
471
472 pos += hdrlen;
473
474 pn64 = atomic64_inc_return(&key->conf.tx_pn);
475
476 pn[5] = pn64;
477 pn[4] = pn64 >> 8;
478 pn[3] = pn64 >> 16;
479 pn[2] = pn64 >> 24;
480 pn[1] = pn64 >> 32;
481 pn[0] = pn64 >> 40;
482
483 ccmp_pn2hdr(pos, pn, key->conf.keyidx);
484
485 /* hwaccel - with software CCMP header */
486 if (info->control.hw_key)
487 return 0;
488
489 pos += IEEE80211_CCMP_HDR_LEN;
490 ccmp_special_blocks(skb, pn, b_0, aad,
491 key->conf.flags & IEEE80211_KEY_FLAG_SPP_AMSDU);
492 return ieee80211_aes_ccm_encrypt(key->u.ccmp.tfm, b_0, aad, pos, len,
493 skb_put(skb, mic_len));
494 }
495
496
497 ieee80211_tx_result
ieee80211_crypto_ccmp_encrypt(struct ieee80211_tx_data * tx,unsigned int mic_len)498 ieee80211_crypto_ccmp_encrypt(struct ieee80211_tx_data *tx,
499 unsigned int mic_len)
500 {
501 struct sk_buff *skb;
502
503 ieee80211_tx_set_protected(tx);
504
505 skb_queue_walk(&tx->skbs, skb) {
506 if (ccmp_encrypt_skb(tx, skb, mic_len) < 0)
507 return TX_DROP;
508 }
509
510 return TX_CONTINUE;
511 }
512
513
514 ieee80211_rx_result
ieee80211_crypto_ccmp_decrypt(struct ieee80211_rx_data * rx,unsigned int mic_len)515 ieee80211_crypto_ccmp_decrypt(struct ieee80211_rx_data *rx,
516 unsigned int mic_len)
517 {
518 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
519 int hdrlen;
520 struct ieee80211_key *key = rx->key;
521 struct sk_buff *skb = rx->skb;
522 struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
523 u8 pn[IEEE80211_CCMP_PN_LEN];
524 int data_len;
525 int queue;
526
527 hdrlen = ieee80211_hdrlen(hdr->frame_control);
528
529 if (!ieee80211_is_data(hdr->frame_control) &&
530 !ieee80211_is_robust_mgmt_frame(skb))
531 return RX_CONTINUE;
532
533 if (status->flag & RX_FLAG_DECRYPTED) {
534 if (!pskb_may_pull(rx->skb, hdrlen + IEEE80211_CCMP_HDR_LEN))
535 return RX_DROP_U_SHORT_CCMP;
536 if (status->flag & RX_FLAG_MIC_STRIPPED)
537 mic_len = 0;
538 } else {
539 if (skb_linearize(rx->skb))
540 return RX_DROP_U_OOM;
541 }
542
543 /* reload hdr - skb might have been reallocated */
544 hdr = (void *)rx->skb->data;
545
546 data_len = skb->len - hdrlen - IEEE80211_CCMP_HDR_LEN - mic_len;
547 if (!rx->sta || data_len < 0)
548 return RX_DROP_U_SHORT_CCMP;
549
550 if (!(status->flag & RX_FLAG_PN_VALIDATED)) {
551 int res;
552
553 ccmp_hdr2pn(pn, skb->data + hdrlen);
554
555 queue = rx->security_idx;
556
557 res = memcmp(pn, key->u.ccmp.rx_pn[queue],
558 IEEE80211_CCMP_PN_LEN);
559 if (res < 0 ||
560 (!res && !(status->flag & RX_FLAG_ALLOW_SAME_PN))) {
561 key->u.ccmp.replays++;
562 return RX_DROP_U_REPLAY;
563 }
564
565 if (!(status->flag & RX_FLAG_DECRYPTED)) {
566 u8 aad[2 * AES_BLOCK_SIZE];
567 u8 b_0[AES_BLOCK_SIZE];
568 /* hardware didn't decrypt/verify MIC */
569 ccmp_special_blocks(skb, pn, b_0, aad,
570 key->conf.flags & IEEE80211_KEY_FLAG_SPP_AMSDU);
571
572 if (ieee80211_aes_ccm_decrypt(
573 key->u.ccmp.tfm, b_0, aad,
574 skb->data + hdrlen + IEEE80211_CCMP_HDR_LEN,
575 data_len,
576 skb->data + skb->len - mic_len))
577 return RX_DROP_U_MIC_FAIL;
578 }
579
580 memcpy(key->u.ccmp.rx_pn[queue], pn, IEEE80211_CCMP_PN_LEN);
581 if (unlikely(ieee80211_is_frag(hdr)))
582 memcpy(rx->ccm_gcm.pn, pn, IEEE80211_CCMP_PN_LEN);
583 }
584
585 /* Remove CCMP header and MIC */
586 if (pskb_trim(skb, skb->len - mic_len))
587 return RX_DROP_U_SHORT_CCMP_MIC;
588 memmove(skb->data + IEEE80211_CCMP_HDR_LEN, skb->data, hdrlen);
589 skb_pull(skb, IEEE80211_CCMP_HDR_LEN);
590
591 return RX_CONTINUE;
592 }
593
gcmp_special_blocks(struct sk_buff * skb,u8 * pn,u8 * j_0,u8 * aad,bool spp_amsdu)594 static void gcmp_special_blocks(struct sk_buff *skb, u8 *pn, u8 *j_0, u8 *aad,
595 bool spp_amsdu)
596 {
597 struct ieee80211_hdr *hdr = (void *)skb->data;
598
599 memcpy(j_0, hdr->addr2, ETH_ALEN);
600 memcpy(&j_0[ETH_ALEN], pn, IEEE80211_GCMP_PN_LEN);
601
602 ccmp_gcmp_aad(skb, aad, spp_amsdu);
603 }
604
gcmp_pn2hdr(u8 * hdr,const u8 * pn,int key_id)605 static inline void gcmp_pn2hdr(u8 *hdr, const u8 *pn, int key_id)
606 {
607 hdr[0] = pn[5];
608 hdr[1] = pn[4];
609 hdr[2] = 0;
610 hdr[3] = 0x20 | (key_id << 6);
611 hdr[4] = pn[3];
612 hdr[5] = pn[2];
613 hdr[6] = pn[1];
614 hdr[7] = pn[0];
615 }
616
gcmp_hdr2pn(u8 * pn,const u8 * hdr)617 static inline void gcmp_hdr2pn(u8 *pn, const u8 *hdr)
618 {
619 pn[0] = hdr[7];
620 pn[1] = hdr[6];
621 pn[2] = hdr[5];
622 pn[3] = hdr[4];
623 pn[4] = hdr[1];
624 pn[5] = hdr[0];
625 }
626
gcmp_encrypt_skb(struct ieee80211_tx_data * tx,struct sk_buff * skb)627 static int gcmp_encrypt_skb(struct ieee80211_tx_data *tx, struct sk_buff *skb)
628 {
629 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
630 struct ieee80211_key *key = tx->key;
631 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
632 int hdrlen, len, tail;
633 u8 *pos;
634 u8 pn[6];
635 u64 pn64;
636 u8 aad[GCM_AAD_LEN];
637 u8 j_0[AES_BLOCK_SIZE];
638
639 if (info->control.hw_key &&
640 !(info->control.hw_key->flags & IEEE80211_KEY_FLAG_GENERATE_IV) &&
641 !(info->control.hw_key->flags & IEEE80211_KEY_FLAG_PUT_IV_SPACE) &&
642 !((info->control.hw_key->flags &
643 IEEE80211_KEY_FLAG_GENERATE_IV_MGMT) &&
644 ieee80211_is_mgmt(hdr->frame_control))) {
645 /* hwaccel has no need for preallocated room for GCMP
646 * header or MIC fields
647 */
648 return 0;
649 }
650
651 hdrlen = ieee80211_hdrlen(hdr->frame_control);
652 len = skb->len - hdrlen;
653
654 if (info->control.hw_key)
655 tail = 0;
656 else
657 tail = IEEE80211_GCMP_MIC_LEN;
658
659 if (WARN_ON(skb_tailroom(skb) < tail ||
660 skb_headroom(skb) < IEEE80211_GCMP_HDR_LEN))
661 return -1;
662
663 pos = skb_push(skb, IEEE80211_GCMP_HDR_LEN);
664 memmove(pos, pos + IEEE80211_GCMP_HDR_LEN, hdrlen);
665 skb_set_network_header(skb, skb_network_offset(skb) +
666 IEEE80211_GCMP_HDR_LEN);
667
668 /* the HW only needs room for the IV, but not the actual IV */
669 if (info->control.hw_key &&
670 (info->control.hw_key->flags & IEEE80211_KEY_FLAG_PUT_IV_SPACE))
671 return 0;
672
673 pos += hdrlen;
674
675 pn64 = atomic64_inc_return(&key->conf.tx_pn);
676
677 pn[5] = pn64;
678 pn[4] = pn64 >> 8;
679 pn[3] = pn64 >> 16;
680 pn[2] = pn64 >> 24;
681 pn[1] = pn64 >> 32;
682 pn[0] = pn64 >> 40;
683
684 gcmp_pn2hdr(pos, pn, key->conf.keyidx);
685
686 /* hwaccel - with software GCMP header */
687 if (info->control.hw_key)
688 return 0;
689
690 pos += IEEE80211_GCMP_HDR_LEN;
691 gcmp_special_blocks(skb, pn, j_0, aad,
692 key->conf.flags & IEEE80211_KEY_FLAG_SPP_AMSDU);
693 return ieee80211_aes_gcm_encrypt(key->u.gcmp.tfm, j_0, aad, pos, len,
694 skb_put(skb, IEEE80211_GCMP_MIC_LEN));
695 }
696
697 ieee80211_tx_result
ieee80211_crypto_gcmp_encrypt(struct ieee80211_tx_data * tx)698 ieee80211_crypto_gcmp_encrypt(struct ieee80211_tx_data *tx)
699 {
700 struct sk_buff *skb;
701
702 ieee80211_tx_set_protected(tx);
703
704 skb_queue_walk(&tx->skbs, skb) {
705 if (gcmp_encrypt_skb(tx, skb) < 0)
706 return TX_DROP;
707 }
708
709 return TX_CONTINUE;
710 }
711
712 ieee80211_rx_result
ieee80211_crypto_gcmp_decrypt(struct ieee80211_rx_data * rx)713 ieee80211_crypto_gcmp_decrypt(struct ieee80211_rx_data *rx)
714 {
715 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
716 int hdrlen;
717 struct ieee80211_key *key = rx->key;
718 struct sk_buff *skb = rx->skb;
719 struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
720 u8 pn[IEEE80211_GCMP_PN_LEN];
721 int data_len, queue, mic_len = IEEE80211_GCMP_MIC_LEN;
722
723 hdrlen = ieee80211_hdrlen(hdr->frame_control);
724
725 if (!ieee80211_is_data(hdr->frame_control) &&
726 !ieee80211_is_robust_mgmt_frame(skb))
727 return RX_CONTINUE;
728
729 if (status->flag & RX_FLAG_DECRYPTED) {
730 if (!pskb_may_pull(rx->skb, hdrlen + IEEE80211_GCMP_HDR_LEN))
731 return RX_DROP_U_SHORT_GCMP;
732 if (status->flag & RX_FLAG_MIC_STRIPPED)
733 mic_len = 0;
734 } else {
735 if (skb_linearize(rx->skb))
736 return RX_DROP_U_OOM;
737 }
738
739 /* reload hdr - skb might have been reallocated */
740 hdr = (void *)rx->skb->data;
741
742 data_len = skb->len - hdrlen - IEEE80211_GCMP_HDR_LEN - mic_len;
743 if (!rx->sta || data_len < 0)
744 return RX_DROP_U_SHORT_GCMP;
745
746 if (!(status->flag & RX_FLAG_PN_VALIDATED)) {
747 int res;
748
749 gcmp_hdr2pn(pn, skb->data + hdrlen);
750
751 queue = rx->security_idx;
752
753 res = memcmp(pn, key->u.gcmp.rx_pn[queue],
754 IEEE80211_GCMP_PN_LEN);
755 if (res < 0 ||
756 (!res && !(status->flag & RX_FLAG_ALLOW_SAME_PN))) {
757 key->u.gcmp.replays++;
758 return RX_DROP_U_REPLAY;
759 }
760
761 if (!(status->flag & RX_FLAG_DECRYPTED)) {
762 u8 aad[2 * AES_BLOCK_SIZE];
763 u8 j_0[AES_BLOCK_SIZE];
764 /* hardware didn't decrypt/verify MIC */
765 gcmp_special_blocks(skb, pn, j_0, aad,
766 key->conf.flags & IEEE80211_KEY_FLAG_SPP_AMSDU);
767
768 if (ieee80211_aes_gcm_decrypt(
769 key->u.gcmp.tfm, j_0, aad,
770 skb->data + hdrlen + IEEE80211_GCMP_HDR_LEN,
771 data_len,
772 skb->data + skb->len -
773 IEEE80211_GCMP_MIC_LEN))
774 return RX_DROP_U_MIC_FAIL;
775 }
776
777 memcpy(key->u.gcmp.rx_pn[queue], pn, IEEE80211_GCMP_PN_LEN);
778 if (unlikely(ieee80211_is_frag(hdr)))
779 memcpy(rx->ccm_gcm.pn, pn, IEEE80211_CCMP_PN_LEN);
780 }
781
782 /* Remove GCMP header and MIC */
783 if (pskb_trim(skb, skb->len - mic_len))
784 return RX_DROP_U_SHORT_GCMP_MIC;
785 memmove(skb->data + IEEE80211_GCMP_HDR_LEN, skb->data, hdrlen);
786 skb_pull(skb, IEEE80211_GCMP_HDR_LEN);
787
788 return RX_CONTINUE;
789 }
790
bip_aad(struct sk_buff * skb,u8 * aad)791 static void bip_aad(struct sk_buff *skb, u8 *aad)
792 {
793 __le16 mask_fc;
794 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
795
796 /* BIP AAD: FC(masked) || A1 || A2 || A3 */
797
798 /* FC type/subtype */
799 /* Mask FC Retry, PwrMgt, MoreData flags to zero */
800 mask_fc = hdr->frame_control;
801 mask_fc &= ~cpu_to_le16(IEEE80211_FCTL_RETRY | IEEE80211_FCTL_PM |
802 IEEE80211_FCTL_MOREDATA);
803 put_unaligned(mask_fc, (__le16 *) &aad[0]);
804 /* A1 || A2 || A3 */
805 memcpy(aad + 2, &hdr->addrs, 3 * ETH_ALEN);
806 }
807
808
bip_ipn_set64(u8 * d,u64 pn)809 static inline void bip_ipn_set64(u8 *d, u64 pn)
810 {
811 *d++ = pn;
812 *d++ = pn >> 8;
813 *d++ = pn >> 16;
814 *d++ = pn >> 24;
815 *d++ = pn >> 32;
816 *d = pn >> 40;
817 }
818
bip_ipn_swap(u8 * d,const u8 * s)819 static inline void bip_ipn_swap(u8 *d, const u8 *s)
820 {
821 *d++ = s[5];
822 *d++ = s[4];
823 *d++ = s[3];
824 *d++ = s[2];
825 *d++ = s[1];
826 *d = s[0];
827 }
828
829
830 ieee80211_tx_result
ieee80211_crypto_aes_cmac_encrypt(struct ieee80211_tx_data * tx)831 ieee80211_crypto_aes_cmac_encrypt(struct ieee80211_tx_data *tx)
832 {
833 struct sk_buff *skb;
834 struct ieee80211_tx_info *info;
835 struct ieee80211_key *key = tx->key;
836 struct ieee80211_mmie *mmie;
837 u8 aad[20];
838 u64 pn64;
839
840 if (WARN_ON(skb_queue_len(&tx->skbs) != 1))
841 return TX_DROP;
842
843 skb = skb_peek(&tx->skbs);
844
845 info = IEEE80211_SKB_CB(skb);
846
847 if (info->control.hw_key &&
848 !(key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_MMIE))
849 return TX_CONTINUE;
850
851 if (WARN_ON(skb_tailroom(skb) < sizeof(*mmie)))
852 return TX_DROP;
853
854 mmie = skb_put(skb, sizeof(*mmie));
855 mmie->element_id = WLAN_EID_MMIE;
856 mmie->length = sizeof(*mmie) - 2;
857 mmie->key_id = cpu_to_le16(key->conf.keyidx);
858
859 /* PN = PN + 1 */
860 pn64 = atomic64_inc_return(&key->conf.tx_pn);
861
862 bip_ipn_set64(mmie->sequence_number, pn64);
863
864 if (info->control.hw_key)
865 return TX_CONTINUE;
866
867 bip_aad(skb, aad);
868
869 /*
870 * MIC = AES-128-CMAC(IGTK, AAD || Management Frame Body || MMIE, 64)
871 */
872 ieee80211_aes_cmac(key->u.aes_cmac.tfm, aad,
873 skb->data + 24, skb->len - 24, mmie->mic);
874
875 return TX_CONTINUE;
876 }
877
878 ieee80211_tx_result
ieee80211_crypto_aes_cmac_256_encrypt(struct ieee80211_tx_data * tx)879 ieee80211_crypto_aes_cmac_256_encrypt(struct ieee80211_tx_data *tx)
880 {
881 struct sk_buff *skb;
882 struct ieee80211_tx_info *info;
883 struct ieee80211_key *key = tx->key;
884 struct ieee80211_mmie_16 *mmie;
885 u8 aad[20];
886 u64 pn64;
887
888 if (WARN_ON(skb_queue_len(&tx->skbs) != 1))
889 return TX_DROP;
890
891 skb = skb_peek(&tx->skbs);
892
893 info = IEEE80211_SKB_CB(skb);
894
895 if (info->control.hw_key &&
896 !(key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_MMIE))
897 return TX_CONTINUE;
898
899 if (WARN_ON(skb_tailroom(skb) < sizeof(*mmie)))
900 return TX_DROP;
901
902 mmie = skb_put(skb, sizeof(*mmie));
903 mmie->element_id = WLAN_EID_MMIE;
904 mmie->length = sizeof(*mmie) - 2;
905 mmie->key_id = cpu_to_le16(key->conf.keyidx);
906
907 /* PN = PN + 1 */
908 pn64 = atomic64_inc_return(&key->conf.tx_pn);
909
910 bip_ipn_set64(mmie->sequence_number, pn64);
911
912 if (info->control.hw_key)
913 return TX_CONTINUE;
914
915 bip_aad(skb, aad);
916
917 /* MIC = AES-256-CMAC(IGTK, AAD || Management Frame Body || MMIE, 128)
918 */
919 ieee80211_aes_cmac_256(key->u.aes_cmac.tfm, aad,
920 skb->data + 24, skb->len - 24, mmie->mic);
921
922 return TX_CONTINUE;
923 }
924
925 ieee80211_rx_result
ieee80211_crypto_aes_cmac_decrypt(struct ieee80211_rx_data * rx)926 ieee80211_crypto_aes_cmac_decrypt(struct ieee80211_rx_data *rx)
927 {
928 struct sk_buff *skb = rx->skb;
929 struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
930 struct ieee80211_key *key = rx->key;
931 struct ieee80211_mmie *mmie;
932 u8 aad[20], mic[8], ipn[6];
933 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
934
935 if (!ieee80211_is_mgmt(hdr->frame_control))
936 return RX_CONTINUE;
937
938 /* management frames are already linear */
939
940 if (skb->len < 24 + sizeof(*mmie))
941 return RX_DROP_U_SHORT_CMAC;
942
943 mmie = (struct ieee80211_mmie *)
944 (skb->data + skb->len - sizeof(*mmie));
945 if (mmie->element_id != WLAN_EID_MMIE ||
946 mmie->length != sizeof(*mmie) - 2)
947 return RX_DROP_U_BAD_MMIE; /* Invalid MMIE */
948
949 bip_ipn_swap(ipn, mmie->sequence_number);
950
951 if (memcmp(ipn, key->u.aes_cmac.rx_pn, 6) <= 0) {
952 key->u.aes_cmac.replays++;
953 return RX_DROP_U_REPLAY;
954 }
955
956 if (!(status->flag & RX_FLAG_DECRYPTED)) {
957 /* hardware didn't decrypt/verify MIC */
958 bip_aad(skb, aad);
959 ieee80211_aes_cmac(key->u.aes_cmac.tfm, aad,
960 skb->data + 24, skb->len - 24, mic);
961 if (crypto_memneq(mic, mmie->mic, sizeof(mmie->mic))) {
962 key->u.aes_cmac.icverrors++;
963 return RX_DROP_U_MIC_FAIL;
964 }
965 }
966
967 memcpy(key->u.aes_cmac.rx_pn, ipn, 6);
968
969 /* Remove MMIE */
970 skb_trim(skb, skb->len - sizeof(*mmie));
971
972 return RX_CONTINUE;
973 }
974
975 ieee80211_rx_result
ieee80211_crypto_aes_cmac_256_decrypt(struct ieee80211_rx_data * rx)976 ieee80211_crypto_aes_cmac_256_decrypt(struct ieee80211_rx_data *rx)
977 {
978 struct sk_buff *skb = rx->skb;
979 struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
980 struct ieee80211_key *key = rx->key;
981 struct ieee80211_mmie_16 *mmie;
982 u8 aad[20], mic[16], ipn[6];
983 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
984
985 if (!ieee80211_is_mgmt(hdr->frame_control))
986 return RX_CONTINUE;
987
988 /* management frames are already linear */
989
990 if (skb->len < 24 + sizeof(*mmie))
991 return RX_DROP_U_SHORT_CMAC256;
992
993 mmie = (struct ieee80211_mmie_16 *)
994 (skb->data + skb->len - sizeof(*mmie));
995 if (mmie->element_id != WLAN_EID_MMIE ||
996 mmie->length != sizeof(*mmie) - 2)
997 return RX_DROP_U_BAD_MMIE; /* Invalid MMIE */
998
999 bip_ipn_swap(ipn, mmie->sequence_number);
1000
1001 if (memcmp(ipn, key->u.aes_cmac.rx_pn, 6) <= 0) {
1002 key->u.aes_cmac.replays++;
1003 return RX_DROP_U_REPLAY;
1004 }
1005
1006 if (!(status->flag & RX_FLAG_DECRYPTED)) {
1007 /* hardware didn't decrypt/verify MIC */
1008 bip_aad(skb, aad);
1009 ieee80211_aes_cmac_256(key->u.aes_cmac.tfm, aad,
1010 skb->data + 24, skb->len - 24, mic);
1011 if (crypto_memneq(mic, mmie->mic, sizeof(mmie->mic))) {
1012 key->u.aes_cmac.icverrors++;
1013 return RX_DROP_U_MIC_FAIL;
1014 }
1015 }
1016
1017 memcpy(key->u.aes_cmac.rx_pn, ipn, 6);
1018
1019 /* Remove MMIE */
1020 skb_trim(skb, skb->len - sizeof(*mmie));
1021
1022 return RX_CONTINUE;
1023 }
1024
1025 ieee80211_tx_result
ieee80211_crypto_aes_gmac_encrypt(struct ieee80211_tx_data * tx)1026 ieee80211_crypto_aes_gmac_encrypt(struct ieee80211_tx_data *tx)
1027 {
1028 struct sk_buff *skb;
1029 struct ieee80211_tx_info *info;
1030 struct ieee80211_key *key = tx->key;
1031 struct ieee80211_mmie_16 *mmie;
1032 struct ieee80211_hdr *hdr;
1033 u8 aad[GMAC_AAD_LEN];
1034 u64 pn64;
1035 u8 nonce[GMAC_NONCE_LEN];
1036
1037 if (WARN_ON(skb_queue_len(&tx->skbs) != 1))
1038 return TX_DROP;
1039
1040 skb = skb_peek(&tx->skbs);
1041
1042 info = IEEE80211_SKB_CB(skb);
1043
1044 if (info->control.hw_key &&
1045 !(key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_MMIE))
1046 return TX_CONTINUE;
1047
1048 if (WARN_ON(skb_tailroom(skb) < sizeof(*mmie)))
1049 return TX_DROP;
1050
1051 mmie = skb_put(skb, sizeof(*mmie));
1052 mmie->element_id = WLAN_EID_MMIE;
1053 mmie->length = sizeof(*mmie) - 2;
1054 mmie->key_id = cpu_to_le16(key->conf.keyidx);
1055
1056 /* PN = PN + 1 */
1057 pn64 = atomic64_inc_return(&key->conf.tx_pn);
1058
1059 bip_ipn_set64(mmie->sequence_number, pn64);
1060
1061 if (info->control.hw_key)
1062 return TX_CONTINUE;
1063
1064 bip_aad(skb, aad);
1065
1066 hdr = (struct ieee80211_hdr *)skb->data;
1067 memcpy(nonce, hdr->addr2, ETH_ALEN);
1068 bip_ipn_swap(nonce + ETH_ALEN, mmie->sequence_number);
1069
1070 /* MIC = AES-GMAC(IGTK, AAD || Management Frame Body || MMIE, 128) */
1071 if (ieee80211_aes_gmac(key->u.aes_gmac.tfm, aad, nonce,
1072 skb->data + 24, skb->len - 24, mmie->mic) < 0)
1073 return TX_DROP;
1074
1075 return TX_CONTINUE;
1076 }
1077
1078 ieee80211_rx_result
ieee80211_crypto_aes_gmac_decrypt(struct ieee80211_rx_data * rx)1079 ieee80211_crypto_aes_gmac_decrypt(struct ieee80211_rx_data *rx)
1080 {
1081 struct sk_buff *skb = rx->skb;
1082 struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
1083 struct ieee80211_key *key = rx->key;
1084 struct ieee80211_mmie_16 *mmie;
1085 u8 aad[GMAC_AAD_LEN], *mic, ipn[6], nonce[GMAC_NONCE_LEN];
1086 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
1087
1088 if (!ieee80211_is_mgmt(hdr->frame_control))
1089 return RX_CONTINUE;
1090
1091 /* management frames are already linear */
1092
1093 if (skb->len < 24 + sizeof(*mmie))
1094 return RX_DROP_U_SHORT_GMAC;
1095
1096 mmie = (struct ieee80211_mmie_16 *)
1097 (skb->data + skb->len - sizeof(*mmie));
1098 if (mmie->element_id != WLAN_EID_MMIE ||
1099 mmie->length != sizeof(*mmie) - 2)
1100 return RX_DROP_U_BAD_MMIE; /* Invalid MMIE */
1101
1102 bip_ipn_swap(ipn, mmie->sequence_number);
1103
1104 if (memcmp(ipn, key->u.aes_gmac.rx_pn, 6) <= 0) {
1105 key->u.aes_gmac.replays++;
1106 return RX_DROP_U_REPLAY;
1107 }
1108
1109 if (!(status->flag & RX_FLAG_DECRYPTED)) {
1110 /* hardware didn't decrypt/verify MIC */
1111 bip_aad(skb, aad);
1112
1113 memcpy(nonce, hdr->addr2, ETH_ALEN);
1114 memcpy(nonce + ETH_ALEN, ipn, 6);
1115
1116 mic = kmalloc(GMAC_MIC_LEN, GFP_ATOMIC);
1117 if (!mic)
1118 return RX_DROP_U_OOM;
1119 if (ieee80211_aes_gmac(key->u.aes_gmac.tfm, aad, nonce,
1120 skb->data + 24, skb->len - 24,
1121 mic) < 0 ||
1122 crypto_memneq(mic, mmie->mic, sizeof(mmie->mic))) {
1123 key->u.aes_gmac.icverrors++;
1124 kfree(mic);
1125 return RX_DROP_U_MIC_FAIL;
1126 }
1127 kfree(mic);
1128 }
1129
1130 memcpy(key->u.aes_gmac.rx_pn, ipn, 6);
1131
1132 /* Remove MMIE */
1133 skb_trim(skb, skb->len - sizeof(*mmie));
1134
1135 return RX_CONTINUE;
1136 }
1137