xref: /openbmc/linux/net/mac80211/wpa.c (revision 8da1985f)
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) 2020-2022 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
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_UNUSABLE;
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_UNUSABLE;
154 
155 	if (skb_linearize(rx->skb))
156 		return RX_DROP_UNUSABLE;
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_UNUSABLE;
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_UNUSABLE;
280 
281 	/* it may be possible to optimize this a bit more */
282 	if (skb_linearize(rx->skb))
283 		return RX_DROP_UNUSABLE;
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_UNUSABLE;
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)318 static u8 ccmp_gcmp_aad(struct sk_buff *skb, u8 *aad)
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_tid(hdr);
344 		mask_fc &= ~cpu_to_le16(IEEE80211_FCTL_ORDER);
345 		len_a += 2;
346 	} else {
347 		qos_tid = 0;
348 	}
349 
350 	/* AAD (extra authenticate-only data) / masked 802.11 header
351 	 * FC | A1 | A2 | A3 | SC | [A4] | [QC] */
352 	put_unaligned_be16(len_a, &aad[0]);
353 	put_unaligned(mask_fc, (__le16 *)&aad[2]);
354 	memcpy(&aad[4], &hdr->addrs, 3 * ETH_ALEN);
355 
356 	/* Mask Seq#, leave Frag# */
357 	aad[22] = *((u8 *) &hdr->seq_ctrl) & 0x0f;
358 	aad[23] = 0;
359 
360 	if (a4_included) {
361 		memcpy(&aad[24], hdr->addr4, ETH_ALEN);
362 		aad[30] = qos_tid;
363 		aad[31] = 0;
364 	} else {
365 		memset(&aad[24], 0, ETH_ALEN + IEEE80211_QOS_CTL_LEN);
366 		aad[24] = qos_tid;
367 	}
368 
369 	return qos_tid;
370 }
371 
ccmp_special_blocks(struct sk_buff * skb,u8 * pn,u8 * b_0,u8 * aad)372 static void ccmp_special_blocks(struct sk_buff *skb, u8 *pn, u8 *b_0, u8 *aad)
373 {
374 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
375 	u8 qos_tid = ccmp_gcmp_aad(skb, aad);
376 
377 	/* In CCM, the initial vectors (IV) used for CTR mode encryption and CBC
378 	 * mode authentication are not allowed to collide, yet both are derived
379 	 * from this vector b_0. We only set L := 1 here to indicate that the
380 	 * data size can be represented in (L+1) bytes. The CCM layer will take
381 	 * care of storing the data length in the top (L+1) bytes and setting
382 	 * and clearing the other bits as is required to derive the two IVs.
383 	 */
384 	b_0[0] = 0x1;
385 
386 	/* Nonce: Nonce Flags | A2 | PN
387 	 * Nonce Flags: Priority (b0..b3) | Management (b4) | Reserved (b5..b7)
388 	 */
389 	b_0[1] = qos_tid | (ieee80211_is_mgmt(hdr->frame_control) << 4);
390 	memcpy(&b_0[2], hdr->addr2, ETH_ALEN);
391 	memcpy(&b_0[8], pn, IEEE80211_CCMP_PN_LEN);
392 }
393 
ccmp_pn2hdr(u8 * hdr,u8 * pn,int key_id)394 static inline void ccmp_pn2hdr(u8 *hdr, u8 *pn, int key_id)
395 {
396 	hdr[0] = pn[5];
397 	hdr[1] = pn[4];
398 	hdr[2] = 0;
399 	hdr[3] = 0x20 | (key_id << 6);
400 	hdr[4] = pn[3];
401 	hdr[5] = pn[2];
402 	hdr[6] = pn[1];
403 	hdr[7] = pn[0];
404 }
405 
406 
ccmp_hdr2pn(u8 * pn,u8 * hdr)407 static inline void ccmp_hdr2pn(u8 *pn, u8 *hdr)
408 {
409 	pn[0] = hdr[7];
410 	pn[1] = hdr[6];
411 	pn[2] = hdr[5];
412 	pn[3] = hdr[4];
413 	pn[4] = hdr[1];
414 	pn[5] = hdr[0];
415 }
416 
417 
ccmp_encrypt_skb(struct ieee80211_tx_data * tx,struct sk_buff * skb,unsigned int mic_len)418 static int ccmp_encrypt_skb(struct ieee80211_tx_data *tx, struct sk_buff *skb,
419 			    unsigned int mic_len)
420 {
421 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
422 	struct ieee80211_key *key = tx->key;
423 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
424 	int hdrlen, len, tail;
425 	u8 *pos;
426 	u8 pn[6];
427 	u64 pn64;
428 	u8 aad[CCM_AAD_LEN];
429 	u8 b_0[AES_BLOCK_SIZE];
430 
431 	if (info->control.hw_key &&
432 	    !(info->control.hw_key->flags & IEEE80211_KEY_FLAG_GENERATE_IV) &&
433 	    !(info->control.hw_key->flags & IEEE80211_KEY_FLAG_PUT_IV_SPACE) &&
434 	    !((info->control.hw_key->flags &
435 	       IEEE80211_KEY_FLAG_GENERATE_IV_MGMT) &&
436 	      ieee80211_is_mgmt(hdr->frame_control))) {
437 		/*
438 		 * hwaccel has no need for preallocated room for CCMP
439 		 * header or MIC fields
440 		 */
441 		return 0;
442 	}
443 
444 	hdrlen = ieee80211_hdrlen(hdr->frame_control);
445 	len = skb->len - hdrlen;
446 
447 	if (info->control.hw_key)
448 		tail = 0;
449 	else
450 		tail = mic_len;
451 
452 	if (WARN_ON(skb_tailroom(skb) < tail ||
453 		    skb_headroom(skb) < IEEE80211_CCMP_HDR_LEN))
454 		return -1;
455 
456 	pos = skb_push(skb, IEEE80211_CCMP_HDR_LEN);
457 	memmove(pos, pos + IEEE80211_CCMP_HDR_LEN, hdrlen);
458 
459 	/* the HW only needs room for the IV, but not the actual IV */
460 	if (info->control.hw_key &&
461 	    (info->control.hw_key->flags & IEEE80211_KEY_FLAG_PUT_IV_SPACE))
462 		return 0;
463 
464 	pos += hdrlen;
465 
466 	pn64 = atomic64_inc_return(&key->conf.tx_pn);
467 
468 	pn[5] = pn64;
469 	pn[4] = pn64 >> 8;
470 	pn[3] = pn64 >> 16;
471 	pn[2] = pn64 >> 24;
472 	pn[1] = pn64 >> 32;
473 	pn[0] = pn64 >> 40;
474 
475 	ccmp_pn2hdr(pos, pn, key->conf.keyidx);
476 
477 	/* hwaccel - with software CCMP header */
478 	if (info->control.hw_key)
479 		return 0;
480 
481 	pos += IEEE80211_CCMP_HDR_LEN;
482 	ccmp_special_blocks(skb, pn, b_0, aad);
483 	return ieee80211_aes_ccm_encrypt(key->u.ccmp.tfm, b_0, aad, pos, len,
484 					 skb_put(skb, mic_len));
485 }
486 
487 
488 ieee80211_tx_result
ieee80211_crypto_ccmp_encrypt(struct ieee80211_tx_data * tx,unsigned int mic_len)489 ieee80211_crypto_ccmp_encrypt(struct ieee80211_tx_data *tx,
490 			      unsigned int mic_len)
491 {
492 	struct sk_buff *skb;
493 
494 	ieee80211_tx_set_protected(tx);
495 
496 	skb_queue_walk(&tx->skbs, skb) {
497 		if (ccmp_encrypt_skb(tx, skb, mic_len) < 0)
498 			return TX_DROP;
499 	}
500 
501 	return TX_CONTINUE;
502 }
503 
504 
505 ieee80211_rx_result
ieee80211_crypto_ccmp_decrypt(struct ieee80211_rx_data * rx,unsigned int mic_len)506 ieee80211_crypto_ccmp_decrypt(struct ieee80211_rx_data *rx,
507 			      unsigned int mic_len)
508 {
509 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
510 	int hdrlen;
511 	struct ieee80211_key *key = rx->key;
512 	struct sk_buff *skb = rx->skb;
513 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
514 	u8 pn[IEEE80211_CCMP_PN_LEN];
515 	int data_len;
516 	int queue;
517 
518 	hdrlen = ieee80211_hdrlen(hdr->frame_control);
519 
520 	if (!ieee80211_is_data(hdr->frame_control) &&
521 	    !ieee80211_is_robust_mgmt_frame(skb))
522 		return RX_CONTINUE;
523 
524 	if (status->flag & RX_FLAG_DECRYPTED) {
525 		if (!pskb_may_pull(rx->skb, hdrlen + IEEE80211_CCMP_HDR_LEN))
526 			return RX_DROP_UNUSABLE;
527 		if (status->flag & RX_FLAG_MIC_STRIPPED)
528 			mic_len = 0;
529 	} else {
530 		if (skb_linearize(rx->skb))
531 			return RX_DROP_UNUSABLE;
532 	}
533 
534 	/* reload hdr - skb might have been reallocated */
535 	hdr = (void *)rx->skb->data;
536 
537 	data_len = skb->len - hdrlen - IEEE80211_CCMP_HDR_LEN - mic_len;
538 	if (!rx->sta || data_len < 0)
539 		return RX_DROP_UNUSABLE;
540 
541 	if (!(status->flag & RX_FLAG_PN_VALIDATED)) {
542 		int res;
543 
544 		ccmp_hdr2pn(pn, skb->data + hdrlen);
545 
546 		queue = rx->security_idx;
547 
548 		res = memcmp(pn, key->u.ccmp.rx_pn[queue],
549 			     IEEE80211_CCMP_PN_LEN);
550 		if (res < 0 ||
551 		    (!res && !(status->flag & RX_FLAG_ALLOW_SAME_PN))) {
552 			key->u.ccmp.replays++;
553 			return RX_DROP_U_REPLAY;
554 		}
555 
556 		if (!(status->flag & RX_FLAG_DECRYPTED)) {
557 			u8 aad[2 * AES_BLOCK_SIZE];
558 			u8 b_0[AES_BLOCK_SIZE];
559 			/* hardware didn't decrypt/verify MIC */
560 			ccmp_special_blocks(skb, pn, b_0, aad);
561 
562 			if (ieee80211_aes_ccm_decrypt(
563 				    key->u.ccmp.tfm, b_0, aad,
564 				    skb->data + hdrlen + IEEE80211_CCMP_HDR_LEN,
565 				    data_len,
566 				    skb->data + skb->len - mic_len))
567 				return RX_DROP_U_MIC_FAIL;
568 		}
569 
570 		memcpy(key->u.ccmp.rx_pn[queue], pn, IEEE80211_CCMP_PN_LEN);
571 		if (unlikely(ieee80211_is_frag(hdr)))
572 			memcpy(rx->ccm_gcm.pn, pn, IEEE80211_CCMP_PN_LEN);
573 	}
574 
575 	/* Remove CCMP header and MIC */
576 	if (pskb_trim(skb, skb->len - mic_len))
577 		return RX_DROP_UNUSABLE;
578 	memmove(skb->data + IEEE80211_CCMP_HDR_LEN, skb->data, hdrlen);
579 	skb_pull(skb, IEEE80211_CCMP_HDR_LEN);
580 
581 	return RX_CONTINUE;
582 }
583 
gcmp_special_blocks(struct sk_buff * skb,u8 * pn,u8 * j_0,u8 * aad)584 static void gcmp_special_blocks(struct sk_buff *skb, u8 *pn, u8 *j_0, u8 *aad)
585 {
586 	struct ieee80211_hdr *hdr = (void *)skb->data;
587 
588 	memcpy(j_0, hdr->addr2, ETH_ALEN);
589 	memcpy(&j_0[ETH_ALEN], pn, IEEE80211_GCMP_PN_LEN);
590 	j_0[13] = 0;
591 	j_0[14] = 0;
592 	j_0[AES_BLOCK_SIZE - 1] = 0x01;
593 
594 	ccmp_gcmp_aad(skb, aad);
595 }
596 
gcmp_pn2hdr(u8 * hdr,const u8 * pn,int key_id)597 static inline void gcmp_pn2hdr(u8 *hdr, const u8 *pn, int key_id)
598 {
599 	hdr[0] = pn[5];
600 	hdr[1] = pn[4];
601 	hdr[2] = 0;
602 	hdr[3] = 0x20 | (key_id << 6);
603 	hdr[4] = pn[3];
604 	hdr[5] = pn[2];
605 	hdr[6] = pn[1];
606 	hdr[7] = pn[0];
607 }
608 
gcmp_hdr2pn(u8 * pn,const u8 * hdr)609 static inline void gcmp_hdr2pn(u8 *pn, const u8 *hdr)
610 {
611 	pn[0] = hdr[7];
612 	pn[1] = hdr[6];
613 	pn[2] = hdr[5];
614 	pn[3] = hdr[4];
615 	pn[4] = hdr[1];
616 	pn[5] = hdr[0];
617 }
618 
gcmp_encrypt_skb(struct ieee80211_tx_data * tx,struct sk_buff * skb)619 static int gcmp_encrypt_skb(struct ieee80211_tx_data *tx, struct sk_buff *skb)
620 {
621 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
622 	struct ieee80211_key *key = tx->key;
623 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
624 	int hdrlen, len, tail;
625 	u8 *pos;
626 	u8 pn[6];
627 	u64 pn64;
628 	u8 aad[GCM_AAD_LEN];
629 	u8 j_0[AES_BLOCK_SIZE];
630 
631 	if (info->control.hw_key &&
632 	    !(info->control.hw_key->flags & IEEE80211_KEY_FLAG_GENERATE_IV) &&
633 	    !(info->control.hw_key->flags & IEEE80211_KEY_FLAG_PUT_IV_SPACE) &&
634 	    !((info->control.hw_key->flags &
635 	       IEEE80211_KEY_FLAG_GENERATE_IV_MGMT) &&
636 	      ieee80211_is_mgmt(hdr->frame_control))) {
637 		/* hwaccel has no need for preallocated room for GCMP
638 		 * header or MIC fields
639 		 */
640 		return 0;
641 	}
642 
643 	hdrlen = ieee80211_hdrlen(hdr->frame_control);
644 	len = skb->len - hdrlen;
645 
646 	if (info->control.hw_key)
647 		tail = 0;
648 	else
649 		tail = IEEE80211_GCMP_MIC_LEN;
650 
651 	if (WARN_ON(skb_tailroom(skb) < tail ||
652 		    skb_headroom(skb) < IEEE80211_GCMP_HDR_LEN))
653 		return -1;
654 
655 	pos = skb_push(skb, IEEE80211_GCMP_HDR_LEN);
656 	memmove(pos, pos + IEEE80211_GCMP_HDR_LEN, hdrlen);
657 	skb_set_network_header(skb, skb_network_offset(skb) +
658 				    IEEE80211_GCMP_HDR_LEN);
659 
660 	/* the HW only needs room for the IV, but not the actual IV */
661 	if (info->control.hw_key &&
662 	    (info->control.hw_key->flags & IEEE80211_KEY_FLAG_PUT_IV_SPACE))
663 		return 0;
664 
665 	pos += hdrlen;
666 
667 	pn64 = atomic64_inc_return(&key->conf.tx_pn);
668 
669 	pn[5] = pn64;
670 	pn[4] = pn64 >> 8;
671 	pn[3] = pn64 >> 16;
672 	pn[2] = pn64 >> 24;
673 	pn[1] = pn64 >> 32;
674 	pn[0] = pn64 >> 40;
675 
676 	gcmp_pn2hdr(pos, pn, key->conf.keyidx);
677 
678 	/* hwaccel - with software GCMP header */
679 	if (info->control.hw_key)
680 		return 0;
681 
682 	pos += IEEE80211_GCMP_HDR_LEN;
683 	gcmp_special_blocks(skb, pn, j_0, aad);
684 	return ieee80211_aes_gcm_encrypt(key->u.gcmp.tfm, j_0, aad, pos, len,
685 					 skb_put(skb, IEEE80211_GCMP_MIC_LEN));
686 }
687 
688 ieee80211_tx_result
ieee80211_crypto_gcmp_encrypt(struct ieee80211_tx_data * tx)689 ieee80211_crypto_gcmp_encrypt(struct ieee80211_tx_data *tx)
690 {
691 	struct sk_buff *skb;
692 
693 	ieee80211_tx_set_protected(tx);
694 
695 	skb_queue_walk(&tx->skbs, skb) {
696 		if (gcmp_encrypt_skb(tx, skb) < 0)
697 			return TX_DROP;
698 	}
699 
700 	return TX_CONTINUE;
701 }
702 
703 ieee80211_rx_result
ieee80211_crypto_gcmp_decrypt(struct ieee80211_rx_data * rx)704 ieee80211_crypto_gcmp_decrypt(struct ieee80211_rx_data *rx)
705 {
706 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
707 	int hdrlen;
708 	struct ieee80211_key *key = rx->key;
709 	struct sk_buff *skb = rx->skb;
710 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
711 	u8 pn[IEEE80211_GCMP_PN_LEN];
712 	int data_len, queue, mic_len = IEEE80211_GCMP_MIC_LEN;
713 
714 	hdrlen = ieee80211_hdrlen(hdr->frame_control);
715 
716 	if (!ieee80211_is_data(hdr->frame_control) &&
717 	    !ieee80211_is_robust_mgmt_frame(skb))
718 		return RX_CONTINUE;
719 
720 	if (status->flag & RX_FLAG_DECRYPTED) {
721 		if (!pskb_may_pull(rx->skb, hdrlen + IEEE80211_GCMP_HDR_LEN))
722 			return RX_DROP_UNUSABLE;
723 		if (status->flag & RX_FLAG_MIC_STRIPPED)
724 			mic_len = 0;
725 	} else {
726 		if (skb_linearize(rx->skb))
727 			return RX_DROP_UNUSABLE;
728 	}
729 
730 	/* reload hdr - skb might have been reallocated */
731 	hdr = (void *)rx->skb->data;
732 
733 	data_len = skb->len - hdrlen - IEEE80211_GCMP_HDR_LEN - mic_len;
734 	if (!rx->sta || data_len < 0)
735 		return RX_DROP_UNUSABLE;
736 
737 	if (!(status->flag & RX_FLAG_PN_VALIDATED)) {
738 		int res;
739 
740 		gcmp_hdr2pn(pn, skb->data + hdrlen);
741 
742 		queue = rx->security_idx;
743 
744 		res = memcmp(pn, key->u.gcmp.rx_pn[queue],
745 			     IEEE80211_GCMP_PN_LEN);
746 		if (res < 0 ||
747 		    (!res && !(status->flag & RX_FLAG_ALLOW_SAME_PN))) {
748 			key->u.gcmp.replays++;
749 			return RX_DROP_U_REPLAY;
750 		}
751 
752 		if (!(status->flag & RX_FLAG_DECRYPTED)) {
753 			u8 aad[2 * AES_BLOCK_SIZE];
754 			u8 j_0[AES_BLOCK_SIZE];
755 			/* hardware didn't decrypt/verify MIC */
756 			gcmp_special_blocks(skb, pn, j_0, aad);
757 
758 			if (ieee80211_aes_gcm_decrypt(
759 				    key->u.gcmp.tfm, j_0, aad,
760 				    skb->data + hdrlen + IEEE80211_GCMP_HDR_LEN,
761 				    data_len,
762 				    skb->data + skb->len -
763 				    IEEE80211_GCMP_MIC_LEN))
764 				return RX_DROP_U_MIC_FAIL;
765 		}
766 
767 		memcpy(key->u.gcmp.rx_pn[queue], pn, IEEE80211_GCMP_PN_LEN);
768 		if (unlikely(ieee80211_is_frag(hdr)))
769 			memcpy(rx->ccm_gcm.pn, pn, IEEE80211_CCMP_PN_LEN);
770 	}
771 
772 	/* Remove GCMP header and MIC */
773 	if (pskb_trim(skb, skb->len - mic_len))
774 		return RX_DROP_UNUSABLE;
775 	memmove(skb->data + IEEE80211_GCMP_HDR_LEN, skb->data, hdrlen);
776 	skb_pull(skb, IEEE80211_GCMP_HDR_LEN);
777 
778 	return RX_CONTINUE;
779 }
780 
bip_aad(struct sk_buff * skb,u8 * aad)781 static void bip_aad(struct sk_buff *skb, u8 *aad)
782 {
783 	__le16 mask_fc;
784 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
785 
786 	/* BIP AAD: FC(masked) || A1 || A2 || A3 */
787 
788 	/* FC type/subtype */
789 	/* Mask FC Retry, PwrMgt, MoreData flags to zero */
790 	mask_fc = hdr->frame_control;
791 	mask_fc &= ~cpu_to_le16(IEEE80211_FCTL_RETRY | IEEE80211_FCTL_PM |
792 				IEEE80211_FCTL_MOREDATA);
793 	put_unaligned(mask_fc, (__le16 *) &aad[0]);
794 	/* A1 || A2 || A3 */
795 	memcpy(aad + 2, &hdr->addrs, 3 * ETH_ALEN);
796 }
797 
798 
bip_ipn_set64(u8 * d,u64 pn)799 static inline void bip_ipn_set64(u8 *d, u64 pn)
800 {
801 	*d++ = pn;
802 	*d++ = pn >> 8;
803 	*d++ = pn >> 16;
804 	*d++ = pn >> 24;
805 	*d++ = pn >> 32;
806 	*d = pn >> 40;
807 }
808 
bip_ipn_swap(u8 * d,const u8 * s)809 static inline void bip_ipn_swap(u8 *d, const u8 *s)
810 {
811 	*d++ = s[5];
812 	*d++ = s[4];
813 	*d++ = s[3];
814 	*d++ = s[2];
815 	*d++ = s[1];
816 	*d = s[0];
817 }
818 
819 
820 ieee80211_tx_result
ieee80211_crypto_aes_cmac_encrypt(struct ieee80211_tx_data * tx)821 ieee80211_crypto_aes_cmac_encrypt(struct ieee80211_tx_data *tx)
822 {
823 	struct sk_buff *skb;
824 	struct ieee80211_tx_info *info;
825 	struct ieee80211_key *key = tx->key;
826 	struct ieee80211_mmie *mmie;
827 	u8 aad[20];
828 	u64 pn64;
829 
830 	if (WARN_ON(skb_queue_len(&tx->skbs) != 1))
831 		return TX_DROP;
832 
833 	skb = skb_peek(&tx->skbs);
834 
835 	info = IEEE80211_SKB_CB(skb);
836 
837 	if (info->control.hw_key &&
838 	    !(key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_MMIE))
839 		return TX_CONTINUE;
840 
841 	if (WARN_ON(skb_tailroom(skb) < sizeof(*mmie)))
842 		return TX_DROP;
843 
844 	mmie = skb_put(skb, sizeof(*mmie));
845 	mmie->element_id = WLAN_EID_MMIE;
846 	mmie->length = sizeof(*mmie) - 2;
847 	mmie->key_id = cpu_to_le16(key->conf.keyidx);
848 
849 	/* PN = PN + 1 */
850 	pn64 = atomic64_inc_return(&key->conf.tx_pn);
851 
852 	bip_ipn_set64(mmie->sequence_number, pn64);
853 
854 	if (info->control.hw_key)
855 		return TX_CONTINUE;
856 
857 	bip_aad(skb, aad);
858 
859 	/*
860 	 * MIC = AES-128-CMAC(IGTK, AAD || Management Frame Body || MMIE, 64)
861 	 */
862 	ieee80211_aes_cmac(key->u.aes_cmac.tfm, aad,
863 			   skb->data + 24, skb->len - 24, mmie->mic);
864 
865 	return TX_CONTINUE;
866 }
867 
868 ieee80211_tx_result
ieee80211_crypto_aes_cmac_256_encrypt(struct ieee80211_tx_data * tx)869 ieee80211_crypto_aes_cmac_256_encrypt(struct ieee80211_tx_data *tx)
870 {
871 	struct sk_buff *skb;
872 	struct ieee80211_tx_info *info;
873 	struct ieee80211_key *key = tx->key;
874 	struct ieee80211_mmie_16 *mmie;
875 	u8 aad[20];
876 	u64 pn64;
877 
878 	if (WARN_ON(skb_queue_len(&tx->skbs) != 1))
879 		return TX_DROP;
880 
881 	skb = skb_peek(&tx->skbs);
882 
883 	info = IEEE80211_SKB_CB(skb);
884 
885 	if (info->control.hw_key)
886 		return TX_CONTINUE;
887 
888 	if (WARN_ON(skb_tailroom(skb) < sizeof(*mmie)))
889 		return TX_DROP;
890 
891 	mmie = skb_put(skb, sizeof(*mmie));
892 	mmie->element_id = WLAN_EID_MMIE;
893 	mmie->length = sizeof(*mmie) - 2;
894 	mmie->key_id = cpu_to_le16(key->conf.keyidx);
895 
896 	/* PN = PN + 1 */
897 	pn64 = atomic64_inc_return(&key->conf.tx_pn);
898 
899 	bip_ipn_set64(mmie->sequence_number, pn64);
900 
901 	bip_aad(skb, aad);
902 
903 	/* MIC = AES-256-CMAC(IGTK, AAD || Management Frame Body || MMIE, 128)
904 	 */
905 	ieee80211_aes_cmac_256(key->u.aes_cmac.tfm, aad,
906 			       skb->data + 24, skb->len - 24, mmie->mic);
907 
908 	return TX_CONTINUE;
909 }
910 
911 ieee80211_rx_result
ieee80211_crypto_aes_cmac_decrypt(struct ieee80211_rx_data * rx)912 ieee80211_crypto_aes_cmac_decrypt(struct ieee80211_rx_data *rx)
913 {
914 	struct sk_buff *skb = rx->skb;
915 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
916 	struct ieee80211_key *key = rx->key;
917 	struct ieee80211_mmie *mmie;
918 	u8 aad[20], mic[8], ipn[6];
919 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
920 
921 	if (!ieee80211_is_mgmt(hdr->frame_control))
922 		return RX_CONTINUE;
923 
924 	/* management frames are already linear */
925 
926 	if (skb->len < 24 + sizeof(*mmie))
927 		return RX_DROP_UNUSABLE;
928 
929 	mmie = (struct ieee80211_mmie *)
930 		(skb->data + skb->len - sizeof(*mmie));
931 	if (mmie->element_id != WLAN_EID_MMIE ||
932 	    mmie->length != sizeof(*mmie) - 2)
933 		return RX_DROP_U_BAD_MMIE; /* Invalid MMIE */
934 
935 	bip_ipn_swap(ipn, mmie->sequence_number);
936 
937 	if (memcmp(ipn, key->u.aes_cmac.rx_pn, 6) <= 0) {
938 		key->u.aes_cmac.replays++;
939 		return RX_DROP_U_REPLAY;
940 	}
941 
942 	if (!(status->flag & RX_FLAG_DECRYPTED)) {
943 		/* hardware didn't decrypt/verify MIC */
944 		bip_aad(skb, aad);
945 		ieee80211_aes_cmac(key->u.aes_cmac.tfm, aad,
946 				   skb->data + 24, skb->len - 24, mic);
947 		if (crypto_memneq(mic, mmie->mic, sizeof(mmie->mic))) {
948 			key->u.aes_cmac.icverrors++;
949 			return RX_DROP_U_MIC_FAIL;
950 		}
951 	}
952 
953 	memcpy(key->u.aes_cmac.rx_pn, ipn, 6);
954 
955 	/* Remove MMIE */
956 	skb_trim(skb, skb->len - sizeof(*mmie));
957 
958 	return RX_CONTINUE;
959 }
960 
961 ieee80211_rx_result
ieee80211_crypto_aes_cmac_256_decrypt(struct ieee80211_rx_data * rx)962 ieee80211_crypto_aes_cmac_256_decrypt(struct ieee80211_rx_data *rx)
963 {
964 	struct sk_buff *skb = rx->skb;
965 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
966 	struct ieee80211_key *key = rx->key;
967 	struct ieee80211_mmie_16 *mmie;
968 	u8 aad[20], mic[16], ipn[6];
969 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
970 
971 	if (!ieee80211_is_mgmt(hdr->frame_control))
972 		return RX_CONTINUE;
973 
974 	/* management frames are already linear */
975 
976 	if (skb->len < 24 + sizeof(*mmie))
977 		return RX_DROP_UNUSABLE;
978 
979 	mmie = (struct ieee80211_mmie_16 *)
980 		(skb->data + skb->len - sizeof(*mmie));
981 	if (mmie->element_id != WLAN_EID_MMIE ||
982 	    mmie->length != sizeof(*mmie) - 2)
983 		return RX_DROP_UNUSABLE; /* Invalid MMIE */
984 
985 	bip_ipn_swap(ipn, mmie->sequence_number);
986 
987 	if (memcmp(ipn, key->u.aes_cmac.rx_pn, 6) <= 0) {
988 		key->u.aes_cmac.replays++;
989 		return RX_DROP_U_REPLAY;
990 	}
991 
992 	if (!(status->flag & RX_FLAG_DECRYPTED)) {
993 		/* hardware didn't decrypt/verify MIC */
994 		bip_aad(skb, aad);
995 		ieee80211_aes_cmac_256(key->u.aes_cmac.tfm, aad,
996 				       skb->data + 24, skb->len - 24, mic);
997 		if (crypto_memneq(mic, mmie->mic, sizeof(mmie->mic))) {
998 			key->u.aes_cmac.icverrors++;
999 			return RX_DROP_U_MIC_FAIL;
1000 		}
1001 	}
1002 
1003 	memcpy(key->u.aes_cmac.rx_pn, ipn, 6);
1004 
1005 	/* Remove MMIE */
1006 	skb_trim(skb, skb->len - sizeof(*mmie));
1007 
1008 	return RX_CONTINUE;
1009 }
1010 
1011 ieee80211_tx_result
ieee80211_crypto_aes_gmac_encrypt(struct ieee80211_tx_data * tx)1012 ieee80211_crypto_aes_gmac_encrypt(struct ieee80211_tx_data *tx)
1013 {
1014 	struct sk_buff *skb;
1015 	struct ieee80211_tx_info *info;
1016 	struct ieee80211_key *key = tx->key;
1017 	struct ieee80211_mmie_16 *mmie;
1018 	struct ieee80211_hdr *hdr;
1019 	u8 aad[GMAC_AAD_LEN];
1020 	u64 pn64;
1021 	u8 nonce[GMAC_NONCE_LEN];
1022 
1023 	if (WARN_ON(skb_queue_len(&tx->skbs) != 1))
1024 		return TX_DROP;
1025 
1026 	skb = skb_peek(&tx->skbs);
1027 
1028 	info = IEEE80211_SKB_CB(skb);
1029 
1030 	if (info->control.hw_key)
1031 		return TX_CONTINUE;
1032 
1033 	if (WARN_ON(skb_tailroom(skb) < sizeof(*mmie)))
1034 		return TX_DROP;
1035 
1036 	mmie = skb_put(skb, sizeof(*mmie));
1037 	mmie->element_id = WLAN_EID_MMIE;
1038 	mmie->length = sizeof(*mmie) - 2;
1039 	mmie->key_id = cpu_to_le16(key->conf.keyidx);
1040 
1041 	/* PN = PN + 1 */
1042 	pn64 = atomic64_inc_return(&key->conf.tx_pn);
1043 
1044 	bip_ipn_set64(mmie->sequence_number, pn64);
1045 
1046 	bip_aad(skb, aad);
1047 
1048 	hdr = (struct ieee80211_hdr *)skb->data;
1049 	memcpy(nonce, hdr->addr2, ETH_ALEN);
1050 	bip_ipn_swap(nonce + ETH_ALEN, mmie->sequence_number);
1051 
1052 	/* MIC = AES-GMAC(IGTK, AAD || Management Frame Body || MMIE, 128) */
1053 	if (ieee80211_aes_gmac(key->u.aes_gmac.tfm, aad, nonce,
1054 			       skb->data + 24, skb->len - 24, mmie->mic) < 0)
1055 		return TX_DROP;
1056 
1057 	return TX_CONTINUE;
1058 }
1059 
1060 ieee80211_rx_result
ieee80211_crypto_aes_gmac_decrypt(struct ieee80211_rx_data * rx)1061 ieee80211_crypto_aes_gmac_decrypt(struct ieee80211_rx_data *rx)
1062 {
1063 	struct sk_buff *skb = rx->skb;
1064 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
1065 	struct ieee80211_key *key = rx->key;
1066 	struct ieee80211_mmie_16 *mmie;
1067 	u8 aad[GMAC_AAD_LEN], *mic, ipn[6], nonce[GMAC_NONCE_LEN];
1068 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
1069 
1070 	if (!ieee80211_is_mgmt(hdr->frame_control))
1071 		return RX_CONTINUE;
1072 
1073 	/* management frames are already linear */
1074 
1075 	if (skb->len < 24 + sizeof(*mmie))
1076 		return RX_DROP_UNUSABLE;
1077 
1078 	mmie = (struct ieee80211_mmie_16 *)
1079 		(skb->data + skb->len - sizeof(*mmie));
1080 	if (mmie->element_id != WLAN_EID_MMIE ||
1081 	    mmie->length != sizeof(*mmie) - 2)
1082 		return RX_DROP_U_BAD_MMIE; /* Invalid MMIE */
1083 
1084 	bip_ipn_swap(ipn, mmie->sequence_number);
1085 
1086 	if (memcmp(ipn, key->u.aes_gmac.rx_pn, 6) <= 0) {
1087 		key->u.aes_gmac.replays++;
1088 		return RX_DROP_U_REPLAY;
1089 	}
1090 
1091 	if (!(status->flag & RX_FLAG_DECRYPTED)) {
1092 		/* hardware didn't decrypt/verify MIC */
1093 		bip_aad(skb, aad);
1094 
1095 		memcpy(nonce, hdr->addr2, ETH_ALEN);
1096 		memcpy(nonce + ETH_ALEN, ipn, 6);
1097 
1098 		mic = kmalloc(GMAC_MIC_LEN, GFP_ATOMIC);
1099 		if (!mic)
1100 			return RX_DROP_UNUSABLE;
1101 		if (ieee80211_aes_gmac(key->u.aes_gmac.tfm, aad, nonce,
1102 				       skb->data + 24, skb->len - 24,
1103 				       mic) < 0 ||
1104 		    crypto_memneq(mic, mmie->mic, sizeof(mmie->mic))) {
1105 			key->u.aes_gmac.icverrors++;
1106 			kfree(mic);
1107 			return RX_DROP_U_MIC_FAIL;
1108 		}
1109 		kfree(mic);
1110 	}
1111 
1112 	memcpy(key->u.aes_gmac.rx_pn, ipn, 6);
1113 
1114 	/* Remove MMIE */
1115 	skb_trim(skb, skb->len - sizeof(*mmie));
1116 
1117 	return RX_CONTINUE;
1118 }
1119