xref: /linux/net/mac80211/wpa.c (revision a36e9f5cfe9eb3a1dce8769c7058251c42705357)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright 2002-2004, Instant802 Networks, Inc.
4  * Copyright 2008, Jouni Malinen <j@w1.fi>
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 <asm/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
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
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 
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
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
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  */
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 
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 
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 
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 
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
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
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 
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 	j_0[13] = 0;
602 	j_0[14] = 0;
603 	j_0[AES_BLOCK_SIZE - 1] = 0x01;
604 
605 	ccmp_gcmp_aad(skb, aad, spp_amsdu);
606 }
607 
608 static inline void gcmp_pn2hdr(u8 *hdr, const u8 *pn, int key_id)
609 {
610 	hdr[0] = pn[5];
611 	hdr[1] = pn[4];
612 	hdr[2] = 0;
613 	hdr[3] = 0x20 | (key_id << 6);
614 	hdr[4] = pn[3];
615 	hdr[5] = pn[2];
616 	hdr[6] = pn[1];
617 	hdr[7] = pn[0];
618 }
619 
620 static inline void gcmp_hdr2pn(u8 *pn, const u8 *hdr)
621 {
622 	pn[0] = hdr[7];
623 	pn[1] = hdr[6];
624 	pn[2] = hdr[5];
625 	pn[3] = hdr[4];
626 	pn[4] = hdr[1];
627 	pn[5] = hdr[0];
628 }
629 
630 static int gcmp_encrypt_skb(struct ieee80211_tx_data *tx, struct sk_buff *skb)
631 {
632 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
633 	struct ieee80211_key *key = tx->key;
634 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
635 	int hdrlen, len, tail;
636 	u8 *pos;
637 	u8 pn[6];
638 	u64 pn64;
639 	u8 aad[GCM_AAD_LEN];
640 	u8 j_0[AES_BLOCK_SIZE];
641 
642 	if (info->control.hw_key &&
643 	    !(info->control.hw_key->flags & IEEE80211_KEY_FLAG_GENERATE_IV) &&
644 	    !(info->control.hw_key->flags & IEEE80211_KEY_FLAG_PUT_IV_SPACE) &&
645 	    !((info->control.hw_key->flags &
646 	       IEEE80211_KEY_FLAG_GENERATE_IV_MGMT) &&
647 	      ieee80211_is_mgmt(hdr->frame_control))) {
648 		/* hwaccel has no need for preallocated room for GCMP
649 		 * header or MIC fields
650 		 */
651 		return 0;
652 	}
653 
654 	hdrlen = ieee80211_hdrlen(hdr->frame_control);
655 	len = skb->len - hdrlen;
656 
657 	if (info->control.hw_key)
658 		tail = 0;
659 	else
660 		tail = IEEE80211_GCMP_MIC_LEN;
661 
662 	if (WARN_ON(skb_tailroom(skb) < tail ||
663 		    skb_headroom(skb) < IEEE80211_GCMP_HDR_LEN))
664 		return -1;
665 
666 	pos = skb_push(skb, IEEE80211_GCMP_HDR_LEN);
667 	memmove(pos, pos + IEEE80211_GCMP_HDR_LEN, hdrlen);
668 	skb_set_network_header(skb, skb_network_offset(skb) +
669 				    IEEE80211_GCMP_HDR_LEN);
670 
671 	/* the HW only needs room for the IV, but not the actual IV */
672 	if (info->control.hw_key &&
673 	    (info->control.hw_key->flags & IEEE80211_KEY_FLAG_PUT_IV_SPACE))
674 		return 0;
675 
676 	pos += hdrlen;
677 
678 	pn64 = atomic64_inc_return(&key->conf.tx_pn);
679 
680 	pn[5] = pn64;
681 	pn[4] = pn64 >> 8;
682 	pn[3] = pn64 >> 16;
683 	pn[2] = pn64 >> 24;
684 	pn[1] = pn64 >> 32;
685 	pn[0] = pn64 >> 40;
686 
687 	gcmp_pn2hdr(pos, pn, key->conf.keyidx);
688 
689 	/* hwaccel - with software GCMP header */
690 	if (info->control.hw_key)
691 		return 0;
692 
693 	pos += IEEE80211_GCMP_HDR_LEN;
694 	gcmp_special_blocks(skb, pn, j_0, aad,
695 			    key->conf.flags & IEEE80211_KEY_FLAG_SPP_AMSDU);
696 	return ieee80211_aes_gcm_encrypt(key->u.gcmp.tfm, j_0, aad, pos, len,
697 					 skb_put(skb, IEEE80211_GCMP_MIC_LEN));
698 }
699 
700 ieee80211_tx_result
701 ieee80211_crypto_gcmp_encrypt(struct ieee80211_tx_data *tx)
702 {
703 	struct sk_buff *skb;
704 
705 	ieee80211_tx_set_protected(tx);
706 
707 	skb_queue_walk(&tx->skbs, skb) {
708 		if (gcmp_encrypt_skb(tx, skb) < 0)
709 			return TX_DROP;
710 	}
711 
712 	return TX_CONTINUE;
713 }
714 
715 ieee80211_rx_result
716 ieee80211_crypto_gcmp_decrypt(struct ieee80211_rx_data *rx)
717 {
718 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
719 	int hdrlen;
720 	struct ieee80211_key *key = rx->key;
721 	struct sk_buff *skb = rx->skb;
722 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
723 	u8 pn[IEEE80211_GCMP_PN_LEN];
724 	int data_len, queue, mic_len = IEEE80211_GCMP_MIC_LEN;
725 
726 	hdrlen = ieee80211_hdrlen(hdr->frame_control);
727 
728 	if (!ieee80211_is_data(hdr->frame_control) &&
729 	    !ieee80211_is_robust_mgmt_frame(skb))
730 		return RX_CONTINUE;
731 
732 	if (status->flag & RX_FLAG_DECRYPTED) {
733 		if (!pskb_may_pull(rx->skb, hdrlen + IEEE80211_GCMP_HDR_LEN))
734 			return RX_DROP_U_SHORT_GCMP;
735 		if (status->flag & RX_FLAG_MIC_STRIPPED)
736 			mic_len = 0;
737 	} else {
738 		if (skb_linearize(rx->skb))
739 			return RX_DROP_U_OOM;
740 	}
741 
742 	/* reload hdr - skb might have been reallocated */
743 	hdr = (void *)rx->skb->data;
744 
745 	data_len = skb->len - hdrlen - IEEE80211_GCMP_HDR_LEN - mic_len;
746 	if (!rx->sta || data_len < 0)
747 		return RX_DROP_U_SHORT_GCMP;
748 
749 	if (!(status->flag & RX_FLAG_PN_VALIDATED)) {
750 		int res;
751 
752 		gcmp_hdr2pn(pn, skb->data + hdrlen);
753 
754 		queue = rx->security_idx;
755 
756 		res = memcmp(pn, key->u.gcmp.rx_pn[queue],
757 			     IEEE80211_GCMP_PN_LEN);
758 		if (res < 0 ||
759 		    (!res && !(status->flag & RX_FLAG_ALLOW_SAME_PN))) {
760 			key->u.gcmp.replays++;
761 			return RX_DROP_U_REPLAY;
762 		}
763 
764 		if (!(status->flag & RX_FLAG_DECRYPTED)) {
765 			u8 aad[2 * AES_BLOCK_SIZE];
766 			u8 j_0[AES_BLOCK_SIZE];
767 			/* hardware didn't decrypt/verify MIC */
768 			gcmp_special_blocks(skb, pn, j_0, aad,
769 					    key->conf.flags & IEEE80211_KEY_FLAG_SPP_AMSDU);
770 
771 			if (ieee80211_aes_gcm_decrypt(
772 				    key->u.gcmp.tfm, j_0, aad,
773 				    skb->data + hdrlen + IEEE80211_GCMP_HDR_LEN,
774 				    data_len,
775 				    skb->data + skb->len -
776 				    IEEE80211_GCMP_MIC_LEN))
777 				return RX_DROP_U_MIC_FAIL;
778 		}
779 
780 		memcpy(key->u.gcmp.rx_pn[queue], pn, IEEE80211_GCMP_PN_LEN);
781 		if (unlikely(ieee80211_is_frag(hdr)))
782 			memcpy(rx->ccm_gcm.pn, pn, IEEE80211_CCMP_PN_LEN);
783 	}
784 
785 	/* Remove GCMP header and MIC */
786 	if (pskb_trim(skb, skb->len - mic_len))
787 		return RX_DROP_U_SHORT_GCMP_MIC;
788 	memmove(skb->data + IEEE80211_GCMP_HDR_LEN, skb->data, hdrlen);
789 	skb_pull(skb, IEEE80211_GCMP_HDR_LEN);
790 
791 	return RX_CONTINUE;
792 }
793 
794 static void bip_aad(struct sk_buff *skb, u8 *aad)
795 {
796 	__le16 mask_fc;
797 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
798 
799 	/* BIP AAD: FC(masked) || A1 || A2 || A3 */
800 
801 	/* FC type/subtype */
802 	/* Mask FC Retry, PwrMgt, MoreData flags to zero */
803 	mask_fc = hdr->frame_control;
804 	mask_fc &= ~cpu_to_le16(IEEE80211_FCTL_RETRY | IEEE80211_FCTL_PM |
805 				IEEE80211_FCTL_MOREDATA);
806 	put_unaligned(mask_fc, (__le16 *) &aad[0]);
807 	/* A1 || A2 || A3 */
808 	memcpy(aad + 2, &hdr->addrs, 3 * ETH_ALEN);
809 }
810 
811 
812 static inline void bip_ipn_set64(u8 *d, u64 pn)
813 {
814 	*d++ = pn;
815 	*d++ = pn >> 8;
816 	*d++ = pn >> 16;
817 	*d++ = pn >> 24;
818 	*d++ = pn >> 32;
819 	*d = pn >> 40;
820 }
821 
822 static inline void bip_ipn_swap(u8 *d, const u8 *s)
823 {
824 	*d++ = s[5];
825 	*d++ = s[4];
826 	*d++ = s[3];
827 	*d++ = s[2];
828 	*d++ = s[1];
829 	*d = s[0];
830 }
831 
832 
833 ieee80211_tx_result
834 ieee80211_crypto_aes_cmac_encrypt(struct ieee80211_tx_data *tx)
835 {
836 	struct sk_buff *skb;
837 	struct ieee80211_tx_info *info;
838 	struct ieee80211_key *key = tx->key;
839 	struct ieee80211_mmie *mmie;
840 	u8 aad[20];
841 	u64 pn64;
842 
843 	if (WARN_ON(skb_queue_len(&tx->skbs) != 1))
844 		return TX_DROP;
845 
846 	skb = skb_peek(&tx->skbs);
847 
848 	info = IEEE80211_SKB_CB(skb);
849 
850 	if (info->control.hw_key &&
851 	    !(key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_MMIE))
852 		return TX_CONTINUE;
853 
854 	if (WARN_ON(skb_tailroom(skb) < sizeof(*mmie)))
855 		return TX_DROP;
856 
857 	mmie = skb_put(skb, sizeof(*mmie));
858 	mmie->element_id = WLAN_EID_MMIE;
859 	mmie->length = sizeof(*mmie) - 2;
860 	mmie->key_id = cpu_to_le16(key->conf.keyidx);
861 
862 	/* PN = PN + 1 */
863 	pn64 = atomic64_inc_return(&key->conf.tx_pn);
864 
865 	bip_ipn_set64(mmie->sequence_number, pn64);
866 
867 	if (info->control.hw_key)
868 		return TX_CONTINUE;
869 
870 	bip_aad(skb, aad);
871 
872 	/*
873 	 * MIC = AES-128-CMAC(IGTK, AAD || Management Frame Body || MMIE, 64)
874 	 */
875 	ieee80211_aes_cmac(key->u.aes_cmac.tfm, aad,
876 			   skb->data + 24, skb->len - 24, mmie->mic);
877 
878 	return TX_CONTINUE;
879 }
880 
881 ieee80211_tx_result
882 ieee80211_crypto_aes_cmac_256_encrypt(struct ieee80211_tx_data *tx)
883 {
884 	struct sk_buff *skb;
885 	struct ieee80211_tx_info *info;
886 	struct ieee80211_key *key = tx->key;
887 	struct ieee80211_mmie_16 *mmie;
888 	u8 aad[20];
889 	u64 pn64;
890 
891 	if (WARN_ON(skb_queue_len(&tx->skbs) != 1))
892 		return TX_DROP;
893 
894 	skb = skb_peek(&tx->skbs);
895 
896 	info = IEEE80211_SKB_CB(skb);
897 
898 	if (info->control.hw_key &&
899 	    !(key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_MMIE))
900 		return TX_CONTINUE;
901 
902 	if (WARN_ON(skb_tailroom(skb) < sizeof(*mmie)))
903 		return TX_DROP;
904 
905 	mmie = skb_put(skb, sizeof(*mmie));
906 	mmie->element_id = WLAN_EID_MMIE;
907 	mmie->length = sizeof(*mmie) - 2;
908 	mmie->key_id = cpu_to_le16(key->conf.keyidx);
909 
910 	/* PN = PN + 1 */
911 	pn64 = atomic64_inc_return(&key->conf.tx_pn);
912 
913 	bip_ipn_set64(mmie->sequence_number, pn64);
914 
915 	if (info->control.hw_key)
916 		return TX_CONTINUE;
917 
918 	bip_aad(skb, aad);
919 
920 	/* MIC = AES-256-CMAC(IGTK, AAD || Management Frame Body || MMIE, 128)
921 	 */
922 	ieee80211_aes_cmac_256(key->u.aes_cmac.tfm, aad,
923 			       skb->data + 24, skb->len - 24, mmie->mic);
924 
925 	return TX_CONTINUE;
926 }
927 
928 ieee80211_rx_result
929 ieee80211_crypto_aes_cmac_decrypt(struct ieee80211_rx_data *rx)
930 {
931 	struct sk_buff *skb = rx->skb;
932 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
933 	struct ieee80211_key *key = rx->key;
934 	struct ieee80211_mmie *mmie;
935 	u8 aad[20], mic[8], ipn[6];
936 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
937 
938 	if (!ieee80211_is_mgmt(hdr->frame_control))
939 		return RX_CONTINUE;
940 
941 	/* management frames are already linear */
942 
943 	if (skb->len < 24 + sizeof(*mmie))
944 		return RX_DROP_U_SHORT_CMAC;
945 
946 	mmie = (struct ieee80211_mmie *)
947 		(skb->data + skb->len - sizeof(*mmie));
948 	if (mmie->element_id != WLAN_EID_MMIE ||
949 	    mmie->length != sizeof(*mmie) - 2)
950 		return RX_DROP_U_BAD_MMIE; /* Invalid MMIE */
951 
952 	bip_ipn_swap(ipn, mmie->sequence_number);
953 
954 	if (memcmp(ipn, key->u.aes_cmac.rx_pn, 6) <= 0) {
955 		key->u.aes_cmac.replays++;
956 		return RX_DROP_U_REPLAY;
957 	}
958 
959 	if (!(status->flag & RX_FLAG_DECRYPTED)) {
960 		/* hardware didn't decrypt/verify MIC */
961 		bip_aad(skb, aad);
962 		ieee80211_aes_cmac(key->u.aes_cmac.tfm, aad,
963 				   skb->data + 24, skb->len - 24, mic);
964 		if (crypto_memneq(mic, mmie->mic, sizeof(mmie->mic))) {
965 			key->u.aes_cmac.icverrors++;
966 			return RX_DROP_U_MIC_FAIL;
967 		}
968 	}
969 
970 	memcpy(key->u.aes_cmac.rx_pn, ipn, 6);
971 
972 	/* Remove MMIE */
973 	skb_trim(skb, skb->len - sizeof(*mmie));
974 
975 	return RX_CONTINUE;
976 }
977 
978 ieee80211_rx_result
979 ieee80211_crypto_aes_cmac_256_decrypt(struct ieee80211_rx_data *rx)
980 {
981 	struct sk_buff *skb = rx->skb;
982 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
983 	struct ieee80211_key *key = rx->key;
984 	struct ieee80211_mmie_16 *mmie;
985 	u8 aad[20], mic[16], ipn[6];
986 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
987 
988 	if (!ieee80211_is_mgmt(hdr->frame_control))
989 		return RX_CONTINUE;
990 
991 	/* management frames are already linear */
992 
993 	if (skb->len < 24 + sizeof(*mmie))
994 		return RX_DROP_U_SHORT_CMAC256;
995 
996 	mmie = (struct ieee80211_mmie_16 *)
997 		(skb->data + skb->len - sizeof(*mmie));
998 	if (mmie->element_id != WLAN_EID_MMIE ||
999 	    mmie->length != sizeof(*mmie) - 2)
1000 		return RX_DROP_U_BAD_MMIE; /* Invalid MMIE */
1001 
1002 	bip_ipn_swap(ipn, mmie->sequence_number);
1003 
1004 	if (memcmp(ipn, key->u.aes_cmac.rx_pn, 6) <= 0) {
1005 		key->u.aes_cmac.replays++;
1006 		return RX_DROP_U_REPLAY;
1007 	}
1008 
1009 	if (!(status->flag & RX_FLAG_DECRYPTED)) {
1010 		/* hardware didn't decrypt/verify MIC */
1011 		bip_aad(skb, aad);
1012 		ieee80211_aes_cmac_256(key->u.aes_cmac.tfm, aad,
1013 				       skb->data + 24, skb->len - 24, mic);
1014 		if (crypto_memneq(mic, mmie->mic, sizeof(mmie->mic))) {
1015 			key->u.aes_cmac.icverrors++;
1016 			return RX_DROP_U_MIC_FAIL;
1017 		}
1018 	}
1019 
1020 	memcpy(key->u.aes_cmac.rx_pn, ipn, 6);
1021 
1022 	/* Remove MMIE */
1023 	skb_trim(skb, skb->len - sizeof(*mmie));
1024 
1025 	return RX_CONTINUE;
1026 }
1027 
1028 ieee80211_tx_result
1029 ieee80211_crypto_aes_gmac_encrypt(struct ieee80211_tx_data *tx)
1030 {
1031 	struct sk_buff *skb;
1032 	struct ieee80211_tx_info *info;
1033 	struct ieee80211_key *key = tx->key;
1034 	struct ieee80211_mmie_16 *mmie;
1035 	struct ieee80211_hdr *hdr;
1036 	u8 aad[GMAC_AAD_LEN];
1037 	u64 pn64;
1038 	u8 nonce[GMAC_NONCE_LEN];
1039 
1040 	if (WARN_ON(skb_queue_len(&tx->skbs) != 1))
1041 		return TX_DROP;
1042 
1043 	skb = skb_peek(&tx->skbs);
1044 
1045 	info = IEEE80211_SKB_CB(skb);
1046 
1047 	if (info->control.hw_key &&
1048 	    !(key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_MMIE))
1049 		return TX_CONTINUE;
1050 
1051 	if (WARN_ON(skb_tailroom(skb) < sizeof(*mmie)))
1052 		return TX_DROP;
1053 
1054 	mmie = skb_put(skb, sizeof(*mmie));
1055 	mmie->element_id = WLAN_EID_MMIE;
1056 	mmie->length = sizeof(*mmie) - 2;
1057 	mmie->key_id = cpu_to_le16(key->conf.keyidx);
1058 
1059 	/* PN = PN + 1 */
1060 	pn64 = atomic64_inc_return(&key->conf.tx_pn);
1061 
1062 	bip_ipn_set64(mmie->sequence_number, pn64);
1063 
1064 	if (info->control.hw_key)
1065 		return TX_CONTINUE;
1066 
1067 	bip_aad(skb, aad);
1068 
1069 	hdr = (struct ieee80211_hdr *)skb->data;
1070 	memcpy(nonce, hdr->addr2, ETH_ALEN);
1071 	bip_ipn_swap(nonce + ETH_ALEN, mmie->sequence_number);
1072 
1073 	/* MIC = AES-GMAC(IGTK, AAD || Management Frame Body || MMIE, 128) */
1074 	if (ieee80211_aes_gmac(key->u.aes_gmac.tfm, aad, nonce,
1075 			       skb->data + 24, skb->len - 24, mmie->mic) < 0)
1076 		return TX_DROP;
1077 
1078 	return TX_CONTINUE;
1079 }
1080 
1081 ieee80211_rx_result
1082 ieee80211_crypto_aes_gmac_decrypt(struct ieee80211_rx_data *rx)
1083 {
1084 	struct sk_buff *skb = rx->skb;
1085 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
1086 	struct ieee80211_key *key = rx->key;
1087 	struct ieee80211_mmie_16 *mmie;
1088 	u8 aad[GMAC_AAD_LEN], *mic, ipn[6], nonce[GMAC_NONCE_LEN];
1089 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
1090 
1091 	if (!ieee80211_is_mgmt(hdr->frame_control))
1092 		return RX_CONTINUE;
1093 
1094 	/* management frames are already linear */
1095 
1096 	if (skb->len < 24 + sizeof(*mmie))
1097 		return RX_DROP_U_SHORT_GMAC;
1098 
1099 	mmie = (struct ieee80211_mmie_16 *)
1100 		(skb->data + skb->len - sizeof(*mmie));
1101 	if (mmie->element_id != WLAN_EID_MMIE ||
1102 	    mmie->length != sizeof(*mmie) - 2)
1103 		return RX_DROP_U_BAD_MMIE; /* Invalid MMIE */
1104 
1105 	bip_ipn_swap(ipn, mmie->sequence_number);
1106 
1107 	if (memcmp(ipn, key->u.aes_gmac.rx_pn, 6) <= 0) {
1108 		key->u.aes_gmac.replays++;
1109 		return RX_DROP_U_REPLAY;
1110 	}
1111 
1112 	if (!(status->flag & RX_FLAG_DECRYPTED)) {
1113 		/* hardware didn't decrypt/verify MIC */
1114 		bip_aad(skb, aad);
1115 
1116 		memcpy(nonce, hdr->addr2, ETH_ALEN);
1117 		memcpy(nonce + ETH_ALEN, ipn, 6);
1118 
1119 		mic = kmalloc(GMAC_MIC_LEN, GFP_ATOMIC);
1120 		if (!mic)
1121 			return RX_DROP_U_OOM;
1122 		if (ieee80211_aes_gmac(key->u.aes_gmac.tfm, aad, nonce,
1123 				       skb->data + 24, skb->len - 24,
1124 				       mic) < 0 ||
1125 		    crypto_memneq(mic, mmie->mic, sizeof(mmie->mic))) {
1126 			key->u.aes_gmac.icverrors++;
1127 			kfree(mic);
1128 			return RX_DROP_U_MIC_FAIL;
1129 		}
1130 		kfree(mic);
1131 	}
1132 
1133 	memcpy(key->u.aes_gmac.rx_pn, ipn, 6);
1134 
1135 	/* Remove MMIE */
1136 	skb_trim(skb, skb->len - sizeof(*mmie));
1137 
1138 	return RX_CONTINUE;
1139 }
1140