xref: /openbmc/linux/net/mac80211/wpa.c (revision 293d5b43)
1 /*
2  * Copyright 2002-2004, Instant802 Networks, Inc.
3  * Copyright 2008, Jouni Malinen <j@w1.fi>
4  * Copyright (C) 2016 Intel Deutschland GmbH
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License version 2 as
8  * published by the Free Software Foundation.
9  */
10 
11 #include <linux/netdevice.h>
12 #include <linux/types.h>
13 #include <linux/skbuff.h>
14 #include <linux/compiler.h>
15 #include <linux/ieee80211.h>
16 #include <linux/gfp.h>
17 #include <asm/unaligned.h>
18 #include <net/mac80211.h>
19 #include <crypto/aes.h>
20 
21 #include "ieee80211_i.h"
22 #include "michael.h"
23 #include "tkip.h"
24 #include "aes_ccm.h"
25 #include "aes_cmac.h"
26 #include "aes_gmac.h"
27 #include "aes_gcm.h"
28 #include "wpa.h"
29 
30 ieee80211_tx_result
31 ieee80211_tx_h_michael_mic_add(struct ieee80211_tx_data *tx)
32 {
33 	u8 *data, *key, *mic;
34 	size_t data_len;
35 	unsigned int hdrlen;
36 	struct ieee80211_hdr *hdr;
37 	struct sk_buff *skb = tx->skb;
38 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
39 	int tail;
40 
41 	hdr = (struct ieee80211_hdr *)skb->data;
42 	if (!tx->key || tx->key->conf.cipher != WLAN_CIPHER_SUITE_TKIP ||
43 	    skb->len < 24 || !ieee80211_is_data_present(hdr->frame_control))
44 		return TX_CONTINUE;
45 
46 	hdrlen = ieee80211_hdrlen(hdr->frame_control);
47 	if (skb->len < hdrlen)
48 		return TX_DROP;
49 
50 	data = skb->data + hdrlen;
51 	data_len = skb->len - hdrlen;
52 
53 	if (unlikely(info->flags & IEEE80211_TX_INTFL_TKIP_MIC_FAILURE)) {
54 		/* Need to use software crypto for the test */
55 		info->control.hw_key = NULL;
56 	}
57 
58 	if (info->control.hw_key &&
59 	    (info->flags & IEEE80211_TX_CTL_DONTFRAG ||
60 	     tx->local->ops->set_frag_threshold) &&
61 	    !(tx->key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_MMIC)) {
62 		/* hwaccel - with no need for SW-generated MMIC */
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 	key = &tx->key->conf.key[NL80211_TKIP_DATA_OFFSET_TX_MIC_KEY];
78 	mic = skb_put(skb, MICHAEL_MIC_LEN);
79 	michael_mic(key, hdr, data, data_len, mic);
80 	if (unlikely(info->flags & IEEE80211_TX_INTFL_TKIP_MIC_FAILURE))
81 		mic[0]++;
82 
83 	return TX_CONTINUE;
84 }
85 
86 
87 ieee80211_rx_result
88 ieee80211_rx_h_michael_mic_verify(struct ieee80211_rx_data *rx)
89 {
90 	u8 *data, *key = NULL;
91 	size_t data_len;
92 	unsigned int hdrlen;
93 	u8 mic[MICHAEL_MIC_LEN];
94 	struct sk_buff *skb = rx->skb;
95 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
96 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
97 
98 	/*
99 	 * it makes no sense to check for MIC errors on anything other
100 	 * than data frames.
101 	 */
102 	if (!ieee80211_is_data_present(hdr->frame_control))
103 		return RX_CONTINUE;
104 
105 	/*
106 	 * No way to verify the MIC if the hardware stripped it or
107 	 * the IV with the key index. In this case we have solely rely
108 	 * on the driver to set RX_FLAG_MMIC_ERROR in the event of a
109 	 * MIC failure report.
110 	 */
111 	if (status->flag & (RX_FLAG_MMIC_STRIPPED | RX_FLAG_IV_STRIPPED)) {
112 		if (status->flag & RX_FLAG_MMIC_ERROR)
113 			goto mic_fail_no_key;
114 
115 		if (!(status->flag & RX_FLAG_IV_STRIPPED) && rx->key &&
116 		    rx->key->conf.cipher == WLAN_CIPHER_SUITE_TKIP)
117 			goto update_iv;
118 
119 		return RX_CONTINUE;
120 	}
121 
122 	/*
123 	 * Some hardware seems to generate Michael MIC failure reports; even
124 	 * though, the frame was not encrypted with TKIP and therefore has no
125 	 * MIC. Ignore the flag them to avoid triggering countermeasures.
126 	 */
127 	if (!rx->key || rx->key->conf.cipher != WLAN_CIPHER_SUITE_TKIP ||
128 	    !(status->flag & RX_FLAG_DECRYPTED))
129 		return RX_CONTINUE;
130 
131 	if (rx->sdata->vif.type == NL80211_IFTYPE_AP && rx->key->conf.keyidx) {
132 		/*
133 		 * APs with pairwise keys should never receive Michael MIC
134 		 * errors for non-zero keyidx because these are reserved for
135 		 * group keys and only the AP is sending real multicast
136 		 * frames in the BSS.
137 		 */
138 		return RX_DROP_UNUSABLE;
139 	}
140 
141 	if (status->flag & RX_FLAG_MMIC_ERROR)
142 		goto mic_fail;
143 
144 	hdrlen = ieee80211_hdrlen(hdr->frame_control);
145 	if (skb->len < hdrlen + MICHAEL_MIC_LEN)
146 		return RX_DROP_UNUSABLE;
147 
148 	if (skb_linearize(rx->skb))
149 		return RX_DROP_UNUSABLE;
150 	hdr = (void *)skb->data;
151 
152 	data = skb->data + hdrlen;
153 	data_len = skb->len - hdrlen - MICHAEL_MIC_LEN;
154 	key = &rx->key->conf.key[NL80211_TKIP_DATA_OFFSET_RX_MIC_KEY];
155 	michael_mic(key, hdr, data, data_len, mic);
156 	if (memcmp(mic, data + data_len, MICHAEL_MIC_LEN) != 0)
157 		goto mic_fail;
158 
159 	/* remove Michael MIC from payload */
160 	skb_trim(skb, skb->len - MICHAEL_MIC_LEN);
161 
162 update_iv:
163 	/* update IV in key information to be able to detect replays */
164 	rx->key->u.tkip.rx[rx->security_idx].iv32 = rx->tkip_iv32;
165 	rx->key->u.tkip.rx[rx->security_idx].iv16 = rx->tkip_iv16;
166 
167 	return RX_CONTINUE;
168 
169 mic_fail:
170 	rx->key->u.tkip.mic_failures++;
171 
172 mic_fail_no_key:
173 	/*
174 	 * In some cases the key can be unset - e.g. a multicast packet, in
175 	 * a driver that supports HW encryption. Send up the key idx only if
176 	 * the key is set.
177 	 */
178 	cfg80211_michael_mic_failure(rx->sdata->dev, hdr->addr2,
179 				     is_multicast_ether_addr(hdr->addr1) ?
180 				     NL80211_KEYTYPE_GROUP :
181 				     NL80211_KEYTYPE_PAIRWISE,
182 				     rx->key ? rx->key->conf.keyidx : -1,
183 				     NULL, GFP_ATOMIC);
184 	return RX_DROP_UNUSABLE;
185 }
186 
187 static int tkip_encrypt_skb(struct ieee80211_tx_data *tx, struct sk_buff *skb)
188 {
189 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
190 	struct ieee80211_key *key = tx->key;
191 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
192 	unsigned int hdrlen;
193 	int len, tail;
194 	u64 pn;
195 	u8 *pos;
196 
197 	if (info->control.hw_key &&
198 	    !(info->control.hw_key->flags & IEEE80211_KEY_FLAG_GENERATE_IV) &&
199 	    !(info->control.hw_key->flags & IEEE80211_KEY_FLAG_PUT_IV_SPACE)) {
200 		/* hwaccel - with no need for software-generated IV */
201 		return 0;
202 	}
203 
204 	hdrlen = ieee80211_hdrlen(hdr->frame_control);
205 	len = skb->len - hdrlen;
206 
207 	if (info->control.hw_key)
208 		tail = 0;
209 	else
210 		tail = IEEE80211_TKIP_ICV_LEN;
211 
212 	if (WARN_ON(skb_tailroom(skb) < tail ||
213 		    skb_headroom(skb) < IEEE80211_TKIP_IV_LEN))
214 		return -1;
215 
216 	pos = skb_push(skb, IEEE80211_TKIP_IV_LEN);
217 	memmove(pos, pos + IEEE80211_TKIP_IV_LEN, hdrlen);
218 	pos += hdrlen;
219 
220 	/* the HW only needs room for the IV, but not the actual IV */
221 	if (info->control.hw_key &&
222 	    (info->control.hw_key->flags & IEEE80211_KEY_FLAG_PUT_IV_SPACE))
223 		return 0;
224 
225 	/* Increase IV for the frame */
226 	pn = atomic64_inc_return(&key->conf.tx_pn);
227 	pos = ieee80211_tkip_add_iv(pos, &key->conf, pn);
228 
229 	/* hwaccel - with software IV */
230 	if (info->control.hw_key)
231 		return 0;
232 
233 	/* Add room for ICV */
234 	skb_put(skb, IEEE80211_TKIP_ICV_LEN);
235 
236 	return ieee80211_tkip_encrypt_data(tx->local->wep_tx_tfm,
237 					   key, skb, pos, len);
238 }
239 
240 
241 ieee80211_tx_result
242 ieee80211_crypto_tkip_encrypt(struct ieee80211_tx_data *tx)
243 {
244 	struct sk_buff *skb;
245 
246 	ieee80211_tx_set_protected(tx);
247 
248 	skb_queue_walk(&tx->skbs, skb) {
249 		if (tkip_encrypt_skb(tx, skb) < 0)
250 			return TX_DROP;
251 	}
252 
253 	return TX_CONTINUE;
254 }
255 
256 
257 ieee80211_rx_result
258 ieee80211_crypto_tkip_decrypt(struct ieee80211_rx_data *rx)
259 {
260 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) rx->skb->data;
261 	int hdrlen, res, hwaccel = 0;
262 	struct ieee80211_key *key = rx->key;
263 	struct sk_buff *skb = rx->skb;
264 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
265 
266 	hdrlen = ieee80211_hdrlen(hdr->frame_control);
267 
268 	if (!ieee80211_is_data(hdr->frame_control))
269 		return RX_CONTINUE;
270 
271 	if (!rx->sta || skb->len - hdrlen < 12)
272 		return RX_DROP_UNUSABLE;
273 
274 	/* it may be possible to optimize this a bit more */
275 	if (skb_linearize(rx->skb))
276 		return RX_DROP_UNUSABLE;
277 	hdr = (void *)skb->data;
278 
279 	/*
280 	 * Let TKIP code verify IV, but skip decryption.
281 	 * In the case where hardware checks the IV as well,
282 	 * we don't even get here, see ieee80211_rx_h_decrypt()
283 	 */
284 	if (status->flag & RX_FLAG_DECRYPTED)
285 		hwaccel = 1;
286 
287 	res = ieee80211_tkip_decrypt_data(rx->local->wep_rx_tfm,
288 					  key, skb->data + hdrlen,
289 					  skb->len - hdrlen, rx->sta->sta.addr,
290 					  hdr->addr1, hwaccel, rx->security_idx,
291 					  &rx->tkip_iv32,
292 					  &rx->tkip_iv16);
293 	if (res != TKIP_DECRYPT_OK)
294 		return RX_DROP_UNUSABLE;
295 
296 	/* Trim ICV */
297 	skb_trim(skb, skb->len - IEEE80211_TKIP_ICV_LEN);
298 
299 	/* Remove IV */
300 	memmove(skb->data + IEEE80211_TKIP_IV_LEN, skb->data, hdrlen);
301 	skb_pull(skb, IEEE80211_TKIP_IV_LEN);
302 
303 	return RX_CONTINUE;
304 }
305 
306 
307 static void ccmp_special_blocks(struct sk_buff *skb, u8 *pn, u8 *b_0, u8 *aad)
308 {
309 	__le16 mask_fc;
310 	int a4_included, mgmt;
311 	u8 qos_tid;
312 	u16 len_a;
313 	unsigned int hdrlen;
314 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
315 
316 	/*
317 	 * Mask FC: zero subtype b4 b5 b6 (if not mgmt)
318 	 * Retry, PwrMgt, MoreData; set Protected
319 	 */
320 	mgmt = ieee80211_is_mgmt(hdr->frame_control);
321 	mask_fc = hdr->frame_control;
322 	mask_fc &= ~cpu_to_le16(IEEE80211_FCTL_RETRY |
323 				IEEE80211_FCTL_PM | IEEE80211_FCTL_MOREDATA);
324 	if (!mgmt)
325 		mask_fc &= ~cpu_to_le16(0x0070);
326 	mask_fc |= cpu_to_le16(IEEE80211_FCTL_PROTECTED);
327 
328 	hdrlen = ieee80211_hdrlen(hdr->frame_control);
329 	len_a = hdrlen - 2;
330 	a4_included = ieee80211_has_a4(hdr->frame_control);
331 
332 	if (ieee80211_is_data_qos(hdr->frame_control))
333 		qos_tid = *ieee80211_get_qos_ctl(hdr) & IEEE80211_QOS_CTL_TID_MASK;
334 	else
335 		qos_tid = 0;
336 
337 	/* In CCM, the initial vectors (IV) used for CTR mode encryption and CBC
338 	 * mode authentication are not allowed to collide, yet both are derived
339 	 * from this vector b_0. We only set L := 1 here to indicate that the
340 	 * data size can be represented in (L+1) bytes. The CCM layer will take
341 	 * care of storing the data length in the top (L+1) bytes and setting
342 	 * and clearing the other bits as is required to derive the two IVs.
343 	 */
344 	b_0[0] = 0x1;
345 
346 	/* Nonce: Nonce Flags | A2 | PN
347 	 * Nonce Flags: Priority (b0..b3) | Management (b4) | Reserved (b5..b7)
348 	 */
349 	b_0[1] = qos_tid | (mgmt << 4);
350 	memcpy(&b_0[2], hdr->addr2, ETH_ALEN);
351 	memcpy(&b_0[8], pn, IEEE80211_CCMP_PN_LEN);
352 
353 	/* AAD (extra authenticate-only data) / masked 802.11 header
354 	 * FC | A1 | A2 | A3 | SC | [A4] | [QC] */
355 	put_unaligned_be16(len_a, &aad[0]);
356 	put_unaligned(mask_fc, (__le16 *)&aad[2]);
357 	memcpy(&aad[4], &hdr->addr1, 3 * ETH_ALEN);
358 
359 	/* Mask Seq#, leave Frag# */
360 	aad[22] = *((u8 *) &hdr->seq_ctrl) & 0x0f;
361 	aad[23] = 0;
362 
363 	if (a4_included) {
364 		memcpy(&aad[24], hdr->addr4, ETH_ALEN);
365 		aad[30] = qos_tid;
366 		aad[31] = 0;
367 	} else {
368 		memset(&aad[24], 0, ETH_ALEN + IEEE80211_QOS_CTL_LEN);
369 		aad[24] = qos_tid;
370 	}
371 }
372 
373 
374 static inline void ccmp_pn2hdr(u8 *hdr, u8 *pn, int key_id)
375 {
376 	hdr[0] = pn[5];
377 	hdr[1] = pn[4];
378 	hdr[2] = 0;
379 	hdr[3] = 0x20 | (key_id << 6);
380 	hdr[4] = pn[3];
381 	hdr[5] = pn[2];
382 	hdr[6] = pn[1];
383 	hdr[7] = pn[0];
384 }
385 
386 
387 static inline void ccmp_hdr2pn(u8 *pn, u8 *hdr)
388 {
389 	pn[0] = hdr[7];
390 	pn[1] = hdr[6];
391 	pn[2] = hdr[5];
392 	pn[3] = hdr[4];
393 	pn[4] = hdr[1];
394 	pn[5] = hdr[0];
395 }
396 
397 
398 static int ccmp_encrypt_skb(struct ieee80211_tx_data *tx, struct sk_buff *skb,
399 			    unsigned int mic_len)
400 {
401 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
402 	struct ieee80211_key *key = tx->key;
403 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
404 	int hdrlen, len, tail;
405 	u8 *pos;
406 	u8 pn[6];
407 	u64 pn64;
408 	u8 aad[2 * AES_BLOCK_SIZE];
409 	u8 b_0[AES_BLOCK_SIZE];
410 
411 	if (info->control.hw_key &&
412 	    !(info->control.hw_key->flags & IEEE80211_KEY_FLAG_GENERATE_IV) &&
413 	    !(info->control.hw_key->flags & IEEE80211_KEY_FLAG_PUT_IV_SPACE) &&
414 	    !((info->control.hw_key->flags &
415 	       IEEE80211_KEY_FLAG_GENERATE_IV_MGMT) &&
416 	      ieee80211_is_mgmt(hdr->frame_control))) {
417 		/*
418 		 * hwaccel has no need for preallocated room for CCMP
419 		 * header or MIC fields
420 		 */
421 		return 0;
422 	}
423 
424 	hdrlen = ieee80211_hdrlen(hdr->frame_control);
425 	len = skb->len - hdrlen;
426 
427 	if (info->control.hw_key)
428 		tail = 0;
429 	else
430 		tail = mic_len;
431 
432 	if (WARN_ON(skb_tailroom(skb) < tail ||
433 		    skb_headroom(skb) < IEEE80211_CCMP_HDR_LEN))
434 		return -1;
435 
436 	pos = skb_push(skb, IEEE80211_CCMP_HDR_LEN);
437 	memmove(pos, pos + IEEE80211_CCMP_HDR_LEN, hdrlen);
438 
439 	/* the HW only needs room for the IV, but not the actual IV */
440 	if (info->control.hw_key &&
441 	    (info->control.hw_key->flags & IEEE80211_KEY_FLAG_PUT_IV_SPACE))
442 		return 0;
443 
444 	hdr = (struct ieee80211_hdr *) pos;
445 	pos += hdrlen;
446 
447 	pn64 = atomic64_inc_return(&key->conf.tx_pn);
448 
449 	pn[5] = pn64;
450 	pn[4] = pn64 >> 8;
451 	pn[3] = pn64 >> 16;
452 	pn[2] = pn64 >> 24;
453 	pn[1] = pn64 >> 32;
454 	pn[0] = pn64 >> 40;
455 
456 	ccmp_pn2hdr(pos, pn, key->conf.keyidx);
457 
458 	/* hwaccel - with software CCMP header */
459 	if (info->control.hw_key)
460 		return 0;
461 
462 	pos += IEEE80211_CCMP_HDR_LEN;
463 	ccmp_special_blocks(skb, pn, b_0, aad);
464 	ieee80211_aes_ccm_encrypt(key->u.ccmp.tfm, b_0, aad, pos, len,
465 				  skb_put(skb, mic_len), mic_len);
466 
467 	return 0;
468 }
469 
470 
471 ieee80211_tx_result
472 ieee80211_crypto_ccmp_encrypt(struct ieee80211_tx_data *tx,
473 			      unsigned int mic_len)
474 {
475 	struct sk_buff *skb;
476 
477 	ieee80211_tx_set_protected(tx);
478 
479 	skb_queue_walk(&tx->skbs, skb) {
480 		if (ccmp_encrypt_skb(tx, skb, mic_len) < 0)
481 			return TX_DROP;
482 	}
483 
484 	return TX_CONTINUE;
485 }
486 
487 
488 ieee80211_rx_result
489 ieee80211_crypto_ccmp_decrypt(struct ieee80211_rx_data *rx,
490 			      unsigned int mic_len)
491 {
492 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
493 	int hdrlen;
494 	struct ieee80211_key *key = rx->key;
495 	struct sk_buff *skb = rx->skb;
496 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
497 	u8 pn[IEEE80211_CCMP_PN_LEN];
498 	int data_len;
499 	int queue;
500 
501 	hdrlen = ieee80211_hdrlen(hdr->frame_control);
502 
503 	if (!ieee80211_is_data(hdr->frame_control) &&
504 	    !ieee80211_is_robust_mgmt_frame(skb))
505 		return RX_CONTINUE;
506 
507 	if (status->flag & RX_FLAG_DECRYPTED) {
508 		if (!pskb_may_pull(rx->skb, hdrlen + IEEE80211_CCMP_HDR_LEN))
509 			return RX_DROP_UNUSABLE;
510 		if (status->flag & RX_FLAG_MIC_STRIPPED)
511 			mic_len = 0;
512 	} else {
513 		if (skb_linearize(rx->skb))
514 			return RX_DROP_UNUSABLE;
515 	}
516 
517 	data_len = skb->len - hdrlen - IEEE80211_CCMP_HDR_LEN - mic_len;
518 	if (!rx->sta || data_len < 0)
519 		return RX_DROP_UNUSABLE;
520 
521 	if (!(status->flag & RX_FLAG_PN_VALIDATED)) {
522 		int res;
523 
524 		ccmp_hdr2pn(pn, skb->data + hdrlen);
525 
526 		queue = rx->security_idx;
527 
528 		res = memcmp(pn, key->u.ccmp.rx_pn[queue],
529 			     IEEE80211_CCMP_PN_LEN);
530 		if (res < 0 ||
531 		    (!res && !(status->flag & RX_FLAG_ALLOW_SAME_PN))) {
532 			key->u.ccmp.replays++;
533 			return RX_DROP_UNUSABLE;
534 		}
535 
536 		if (!(status->flag & RX_FLAG_DECRYPTED)) {
537 			u8 aad[2 * AES_BLOCK_SIZE];
538 			u8 b_0[AES_BLOCK_SIZE];
539 			/* hardware didn't decrypt/verify MIC */
540 			ccmp_special_blocks(skb, pn, b_0, aad);
541 
542 			if (ieee80211_aes_ccm_decrypt(
543 				    key->u.ccmp.tfm, b_0, aad,
544 				    skb->data + hdrlen + IEEE80211_CCMP_HDR_LEN,
545 				    data_len,
546 				    skb->data + skb->len - mic_len, mic_len))
547 				return RX_DROP_UNUSABLE;
548 		}
549 
550 		memcpy(key->u.ccmp.rx_pn[queue], pn, IEEE80211_CCMP_PN_LEN);
551 	}
552 
553 	/* Remove CCMP header and MIC */
554 	if (pskb_trim(skb, skb->len - mic_len))
555 		return RX_DROP_UNUSABLE;
556 	memmove(skb->data + IEEE80211_CCMP_HDR_LEN, skb->data, hdrlen);
557 	skb_pull(skb, IEEE80211_CCMP_HDR_LEN);
558 
559 	return RX_CONTINUE;
560 }
561 
562 static void gcmp_special_blocks(struct sk_buff *skb, u8 *pn, u8 *j_0, u8 *aad)
563 {
564 	__le16 mask_fc;
565 	u8 qos_tid;
566 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
567 
568 	memcpy(j_0, hdr->addr2, ETH_ALEN);
569 	memcpy(&j_0[ETH_ALEN], pn, IEEE80211_GCMP_PN_LEN);
570 	j_0[13] = 0;
571 	j_0[14] = 0;
572 	j_0[AES_BLOCK_SIZE - 1] = 0x01;
573 
574 	/* AAD (extra authenticate-only data) / masked 802.11 header
575 	 * FC | A1 | A2 | A3 | SC | [A4] | [QC]
576 	 */
577 	put_unaligned_be16(ieee80211_hdrlen(hdr->frame_control) - 2, &aad[0]);
578 	/* Mask FC: zero subtype b4 b5 b6 (if not mgmt)
579 	 * Retry, PwrMgt, MoreData; set Protected
580 	 */
581 	mask_fc = hdr->frame_control;
582 	mask_fc &= ~cpu_to_le16(IEEE80211_FCTL_RETRY |
583 				IEEE80211_FCTL_PM | IEEE80211_FCTL_MOREDATA);
584 	if (!ieee80211_is_mgmt(hdr->frame_control))
585 		mask_fc &= ~cpu_to_le16(0x0070);
586 	mask_fc |= cpu_to_le16(IEEE80211_FCTL_PROTECTED);
587 
588 	put_unaligned(mask_fc, (__le16 *)&aad[2]);
589 	memcpy(&aad[4], &hdr->addr1, 3 * ETH_ALEN);
590 
591 	/* Mask Seq#, leave Frag# */
592 	aad[22] = *((u8 *)&hdr->seq_ctrl) & 0x0f;
593 	aad[23] = 0;
594 
595 	if (ieee80211_is_data_qos(hdr->frame_control))
596 		qos_tid = *ieee80211_get_qos_ctl(hdr) &
597 			IEEE80211_QOS_CTL_TID_MASK;
598 	else
599 		qos_tid = 0;
600 
601 	if (ieee80211_has_a4(hdr->frame_control)) {
602 		memcpy(&aad[24], hdr->addr4, ETH_ALEN);
603 		aad[30] = qos_tid;
604 		aad[31] = 0;
605 	} else {
606 		memset(&aad[24], 0, ETH_ALEN + IEEE80211_QOS_CTL_LEN);
607 		aad[24] = qos_tid;
608 	}
609 }
610 
611 static inline void gcmp_pn2hdr(u8 *hdr, const u8 *pn, int key_id)
612 {
613 	hdr[0] = pn[5];
614 	hdr[1] = pn[4];
615 	hdr[2] = 0;
616 	hdr[3] = 0x20 | (key_id << 6);
617 	hdr[4] = pn[3];
618 	hdr[5] = pn[2];
619 	hdr[6] = pn[1];
620 	hdr[7] = pn[0];
621 }
622 
623 static inline void gcmp_hdr2pn(u8 *pn, const u8 *hdr)
624 {
625 	pn[0] = hdr[7];
626 	pn[1] = hdr[6];
627 	pn[2] = hdr[5];
628 	pn[3] = hdr[4];
629 	pn[4] = hdr[1];
630 	pn[5] = hdr[0];
631 }
632 
633 static int gcmp_encrypt_skb(struct ieee80211_tx_data *tx, struct sk_buff *skb)
634 {
635 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
636 	struct ieee80211_key *key = tx->key;
637 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
638 	int hdrlen, len, tail;
639 	u8 *pos;
640 	u8 pn[6];
641 	u64 pn64;
642 	u8 aad[2 * AES_BLOCK_SIZE];
643 	u8 j_0[AES_BLOCK_SIZE];
644 
645 	if (info->control.hw_key &&
646 	    !(info->control.hw_key->flags & IEEE80211_KEY_FLAG_GENERATE_IV) &&
647 	    !(info->control.hw_key->flags & IEEE80211_KEY_FLAG_PUT_IV_SPACE) &&
648 	    !((info->control.hw_key->flags &
649 	       IEEE80211_KEY_FLAG_GENERATE_IV_MGMT) &&
650 	      ieee80211_is_mgmt(hdr->frame_control))) {
651 		/* hwaccel has no need for preallocated room for GCMP
652 		 * header or MIC fields
653 		 */
654 		return 0;
655 	}
656 
657 	hdrlen = ieee80211_hdrlen(hdr->frame_control);
658 	len = skb->len - hdrlen;
659 
660 	if (info->control.hw_key)
661 		tail = 0;
662 	else
663 		tail = IEEE80211_GCMP_MIC_LEN;
664 
665 	if (WARN_ON(skb_tailroom(skb) < tail ||
666 		    skb_headroom(skb) < IEEE80211_GCMP_HDR_LEN))
667 		return -1;
668 
669 	pos = skb_push(skb, IEEE80211_GCMP_HDR_LEN);
670 	memmove(pos, pos + IEEE80211_GCMP_HDR_LEN, hdrlen);
671 	skb_set_network_header(skb, skb_network_offset(skb) +
672 				    IEEE80211_GCMP_HDR_LEN);
673 
674 	/* the HW only needs room for the IV, but not the actual IV */
675 	if (info->control.hw_key &&
676 	    (info->control.hw_key->flags & IEEE80211_KEY_FLAG_PUT_IV_SPACE))
677 		return 0;
678 
679 	hdr = (struct ieee80211_hdr *)pos;
680 	pos += hdrlen;
681 
682 	pn64 = atomic64_inc_return(&key->conf.tx_pn);
683 
684 	pn[5] = pn64;
685 	pn[4] = pn64 >> 8;
686 	pn[3] = pn64 >> 16;
687 	pn[2] = pn64 >> 24;
688 	pn[1] = pn64 >> 32;
689 	pn[0] = pn64 >> 40;
690 
691 	gcmp_pn2hdr(pos, pn, key->conf.keyidx);
692 
693 	/* hwaccel - with software GCMP header */
694 	if (info->control.hw_key)
695 		return 0;
696 
697 	pos += IEEE80211_GCMP_HDR_LEN;
698 	gcmp_special_blocks(skb, pn, j_0, aad);
699 	ieee80211_aes_gcm_encrypt(key->u.gcmp.tfm, j_0, aad, pos, len,
700 				  skb_put(skb, IEEE80211_GCMP_MIC_LEN));
701 
702 	return 0;
703 }
704 
705 ieee80211_tx_result
706 ieee80211_crypto_gcmp_encrypt(struct ieee80211_tx_data *tx)
707 {
708 	struct sk_buff *skb;
709 
710 	ieee80211_tx_set_protected(tx);
711 
712 	skb_queue_walk(&tx->skbs, skb) {
713 		if (gcmp_encrypt_skb(tx, skb) < 0)
714 			return TX_DROP;
715 	}
716 
717 	return TX_CONTINUE;
718 }
719 
720 ieee80211_rx_result
721 ieee80211_crypto_gcmp_decrypt(struct ieee80211_rx_data *rx)
722 {
723 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
724 	int hdrlen;
725 	struct ieee80211_key *key = rx->key;
726 	struct sk_buff *skb = rx->skb;
727 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
728 	u8 pn[IEEE80211_GCMP_PN_LEN];
729 	int data_len, queue, mic_len = IEEE80211_GCMP_MIC_LEN;
730 
731 	hdrlen = ieee80211_hdrlen(hdr->frame_control);
732 
733 	if (!ieee80211_is_data(hdr->frame_control) &&
734 	    !ieee80211_is_robust_mgmt_frame(skb))
735 		return RX_CONTINUE;
736 
737 	if (status->flag & RX_FLAG_DECRYPTED) {
738 		if (!pskb_may_pull(rx->skb, hdrlen + IEEE80211_GCMP_HDR_LEN))
739 			return RX_DROP_UNUSABLE;
740 		if (status->flag & RX_FLAG_MIC_STRIPPED)
741 			mic_len = 0;
742 	} else {
743 		if (skb_linearize(rx->skb))
744 			return RX_DROP_UNUSABLE;
745 	}
746 
747 	data_len = skb->len - hdrlen - IEEE80211_GCMP_HDR_LEN - mic_len;
748 	if (!rx->sta || data_len < 0)
749 		return RX_DROP_UNUSABLE;
750 
751 	if (!(status->flag & RX_FLAG_PN_VALIDATED)) {
752 		int res;
753 
754 		gcmp_hdr2pn(pn, skb->data + hdrlen);
755 
756 		queue = rx->security_idx;
757 
758 		res = memcmp(pn, key->u.gcmp.rx_pn[queue],
759 			     IEEE80211_GCMP_PN_LEN);
760 		if (res < 0 ||
761 		    (!res && !(status->flag & RX_FLAG_ALLOW_SAME_PN))) {
762 			key->u.gcmp.replays++;
763 			return RX_DROP_UNUSABLE;
764 		}
765 
766 		if (!(status->flag & RX_FLAG_DECRYPTED)) {
767 			u8 aad[2 * AES_BLOCK_SIZE];
768 			u8 j_0[AES_BLOCK_SIZE];
769 			/* hardware didn't decrypt/verify MIC */
770 			gcmp_special_blocks(skb, pn, j_0, aad);
771 
772 			if (ieee80211_aes_gcm_decrypt(
773 				    key->u.gcmp.tfm, j_0, aad,
774 				    skb->data + hdrlen + IEEE80211_GCMP_HDR_LEN,
775 				    data_len,
776 				    skb->data + skb->len -
777 				    IEEE80211_GCMP_MIC_LEN))
778 				return RX_DROP_UNUSABLE;
779 		}
780 
781 		memcpy(key->u.gcmp.rx_pn[queue], pn, IEEE80211_GCMP_PN_LEN);
782 	}
783 
784 	/* Remove GCMP header and MIC */
785 	if (pskb_trim(skb, skb->len - mic_len))
786 		return RX_DROP_UNUSABLE;
787 	memmove(skb->data + IEEE80211_GCMP_HDR_LEN, skb->data, hdrlen);
788 	skb_pull(skb, IEEE80211_GCMP_HDR_LEN);
789 
790 	return RX_CONTINUE;
791 }
792 
793 static ieee80211_tx_result
794 ieee80211_crypto_cs_encrypt(struct ieee80211_tx_data *tx,
795 			    struct sk_buff *skb)
796 {
797 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
798 	struct ieee80211_key *key = tx->key;
799 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
800 	int hdrlen;
801 	u8 *pos, iv_len = key->conf.iv_len;
802 
803 	if (info->control.hw_key &&
804 	    !(info->control.hw_key->flags & IEEE80211_KEY_FLAG_PUT_IV_SPACE)) {
805 		/* hwaccel has no need for preallocated head room */
806 		return TX_CONTINUE;
807 	}
808 
809 	if (unlikely(skb_headroom(skb) < iv_len &&
810 		     pskb_expand_head(skb, iv_len, 0, GFP_ATOMIC)))
811 		return TX_DROP;
812 
813 	hdrlen = ieee80211_hdrlen(hdr->frame_control);
814 
815 	pos = skb_push(skb, iv_len);
816 	memmove(pos, pos + iv_len, hdrlen);
817 
818 	return TX_CONTINUE;
819 }
820 
821 static inline int ieee80211_crypto_cs_pn_compare(u8 *pn1, u8 *pn2, int len)
822 {
823 	int i;
824 
825 	/* pn is little endian */
826 	for (i = len - 1; i >= 0; i--) {
827 		if (pn1[i] < pn2[i])
828 			return -1;
829 		else if (pn1[i] > pn2[i])
830 			return 1;
831 	}
832 
833 	return 0;
834 }
835 
836 static ieee80211_rx_result
837 ieee80211_crypto_cs_decrypt(struct ieee80211_rx_data *rx)
838 {
839 	struct ieee80211_key *key = rx->key;
840 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
841 	const struct ieee80211_cipher_scheme *cs = NULL;
842 	int hdrlen = ieee80211_hdrlen(hdr->frame_control);
843 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
844 	int data_len;
845 	u8 *rx_pn;
846 	u8 *skb_pn;
847 	u8 qos_tid;
848 
849 	if (!rx->sta || !rx->sta->cipher_scheme ||
850 	    !(status->flag & RX_FLAG_DECRYPTED))
851 		return RX_DROP_UNUSABLE;
852 
853 	if (!ieee80211_is_data(hdr->frame_control))
854 		return RX_CONTINUE;
855 
856 	cs = rx->sta->cipher_scheme;
857 
858 	data_len = rx->skb->len - hdrlen - cs->hdr_len;
859 
860 	if (data_len < 0)
861 		return RX_DROP_UNUSABLE;
862 
863 	if (ieee80211_is_data_qos(hdr->frame_control))
864 		qos_tid = *ieee80211_get_qos_ctl(hdr) &
865 				IEEE80211_QOS_CTL_TID_MASK;
866 	else
867 		qos_tid = 0;
868 
869 	if (skb_linearize(rx->skb))
870 		return RX_DROP_UNUSABLE;
871 
872 	hdr = (struct ieee80211_hdr *)rx->skb->data;
873 
874 	rx_pn = key->u.gen.rx_pn[qos_tid];
875 	skb_pn = rx->skb->data + hdrlen + cs->pn_off;
876 
877 	if (ieee80211_crypto_cs_pn_compare(skb_pn, rx_pn, cs->pn_len) <= 0)
878 		return RX_DROP_UNUSABLE;
879 
880 	memcpy(rx_pn, skb_pn, cs->pn_len);
881 
882 	/* remove security header and MIC */
883 	if (pskb_trim(rx->skb, rx->skb->len - cs->mic_len))
884 		return RX_DROP_UNUSABLE;
885 
886 	memmove(rx->skb->data + cs->hdr_len, rx->skb->data, hdrlen);
887 	skb_pull(rx->skb, cs->hdr_len);
888 
889 	return RX_CONTINUE;
890 }
891 
892 static void bip_aad(struct sk_buff *skb, u8 *aad)
893 {
894 	__le16 mask_fc;
895 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
896 
897 	/* BIP AAD: FC(masked) || A1 || A2 || A3 */
898 
899 	/* FC type/subtype */
900 	/* Mask FC Retry, PwrMgt, MoreData flags to zero */
901 	mask_fc = hdr->frame_control;
902 	mask_fc &= ~cpu_to_le16(IEEE80211_FCTL_RETRY | IEEE80211_FCTL_PM |
903 				IEEE80211_FCTL_MOREDATA);
904 	put_unaligned(mask_fc, (__le16 *) &aad[0]);
905 	/* A1 || A2 || A3 */
906 	memcpy(aad + 2, &hdr->addr1, 3 * ETH_ALEN);
907 }
908 
909 
910 static inline void bip_ipn_set64(u8 *d, u64 pn)
911 {
912 	*d++ = pn;
913 	*d++ = pn >> 8;
914 	*d++ = pn >> 16;
915 	*d++ = pn >> 24;
916 	*d++ = pn >> 32;
917 	*d = pn >> 40;
918 }
919 
920 static inline void bip_ipn_swap(u8 *d, const u8 *s)
921 {
922 	*d++ = s[5];
923 	*d++ = s[4];
924 	*d++ = s[3];
925 	*d++ = s[2];
926 	*d++ = s[1];
927 	*d = s[0];
928 }
929 
930 
931 ieee80211_tx_result
932 ieee80211_crypto_aes_cmac_encrypt(struct ieee80211_tx_data *tx)
933 {
934 	struct sk_buff *skb;
935 	struct ieee80211_tx_info *info;
936 	struct ieee80211_key *key = tx->key;
937 	struct ieee80211_mmie *mmie;
938 	u8 aad[20];
939 	u64 pn64;
940 
941 	if (WARN_ON(skb_queue_len(&tx->skbs) != 1))
942 		return TX_DROP;
943 
944 	skb = skb_peek(&tx->skbs);
945 
946 	info = IEEE80211_SKB_CB(skb);
947 
948 	if (info->control.hw_key)
949 		return TX_CONTINUE;
950 
951 	if (WARN_ON(skb_tailroom(skb) < sizeof(*mmie)))
952 		return TX_DROP;
953 
954 	mmie = (struct ieee80211_mmie *) skb_put(skb, sizeof(*mmie));
955 	mmie->element_id = WLAN_EID_MMIE;
956 	mmie->length = sizeof(*mmie) - 2;
957 	mmie->key_id = cpu_to_le16(key->conf.keyidx);
958 
959 	/* PN = PN + 1 */
960 	pn64 = atomic64_inc_return(&key->conf.tx_pn);
961 
962 	bip_ipn_set64(mmie->sequence_number, pn64);
963 
964 	bip_aad(skb, aad);
965 
966 	/*
967 	 * MIC = AES-128-CMAC(IGTK, AAD || Management Frame Body || MMIE, 64)
968 	 */
969 	ieee80211_aes_cmac(key->u.aes_cmac.tfm, aad,
970 			   skb->data + 24, skb->len - 24, mmie->mic);
971 
972 	return TX_CONTINUE;
973 }
974 
975 ieee80211_tx_result
976 ieee80211_crypto_aes_cmac_256_encrypt(struct ieee80211_tx_data *tx)
977 {
978 	struct sk_buff *skb;
979 	struct ieee80211_tx_info *info;
980 	struct ieee80211_key *key = tx->key;
981 	struct ieee80211_mmie_16 *mmie;
982 	u8 aad[20];
983 	u64 pn64;
984 
985 	if (WARN_ON(skb_queue_len(&tx->skbs) != 1))
986 		return TX_DROP;
987 
988 	skb = skb_peek(&tx->skbs);
989 
990 	info = IEEE80211_SKB_CB(skb);
991 
992 	if (info->control.hw_key)
993 		return TX_CONTINUE;
994 
995 	if (WARN_ON(skb_tailroom(skb) < sizeof(*mmie)))
996 		return TX_DROP;
997 
998 	mmie = (struct ieee80211_mmie_16 *)skb_put(skb, sizeof(*mmie));
999 	mmie->element_id = WLAN_EID_MMIE;
1000 	mmie->length = sizeof(*mmie) - 2;
1001 	mmie->key_id = cpu_to_le16(key->conf.keyidx);
1002 
1003 	/* PN = PN + 1 */
1004 	pn64 = atomic64_inc_return(&key->conf.tx_pn);
1005 
1006 	bip_ipn_set64(mmie->sequence_number, pn64);
1007 
1008 	bip_aad(skb, aad);
1009 
1010 	/* MIC = AES-256-CMAC(IGTK, AAD || Management Frame Body || MMIE, 128)
1011 	 */
1012 	ieee80211_aes_cmac_256(key->u.aes_cmac.tfm, aad,
1013 			       skb->data + 24, skb->len - 24, mmie->mic);
1014 
1015 	return TX_CONTINUE;
1016 }
1017 
1018 ieee80211_rx_result
1019 ieee80211_crypto_aes_cmac_decrypt(struct ieee80211_rx_data *rx)
1020 {
1021 	struct sk_buff *skb = rx->skb;
1022 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
1023 	struct ieee80211_key *key = rx->key;
1024 	struct ieee80211_mmie *mmie;
1025 	u8 aad[20], mic[8], ipn[6];
1026 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
1027 
1028 	if (!ieee80211_is_mgmt(hdr->frame_control))
1029 		return RX_CONTINUE;
1030 
1031 	/* management frames are already linear */
1032 
1033 	if (skb->len < 24 + sizeof(*mmie))
1034 		return RX_DROP_UNUSABLE;
1035 
1036 	mmie = (struct ieee80211_mmie *)
1037 		(skb->data + skb->len - sizeof(*mmie));
1038 	if (mmie->element_id != WLAN_EID_MMIE ||
1039 	    mmie->length != sizeof(*mmie) - 2)
1040 		return RX_DROP_UNUSABLE; /* Invalid MMIE */
1041 
1042 	bip_ipn_swap(ipn, mmie->sequence_number);
1043 
1044 	if (memcmp(ipn, key->u.aes_cmac.rx_pn, 6) <= 0) {
1045 		key->u.aes_cmac.replays++;
1046 		return RX_DROP_UNUSABLE;
1047 	}
1048 
1049 	if (!(status->flag & RX_FLAG_DECRYPTED)) {
1050 		/* hardware didn't decrypt/verify MIC */
1051 		bip_aad(skb, aad);
1052 		ieee80211_aes_cmac(key->u.aes_cmac.tfm, aad,
1053 				   skb->data + 24, skb->len - 24, mic);
1054 		if (memcmp(mic, mmie->mic, sizeof(mmie->mic)) != 0) {
1055 			key->u.aes_cmac.icverrors++;
1056 			return RX_DROP_UNUSABLE;
1057 		}
1058 	}
1059 
1060 	memcpy(key->u.aes_cmac.rx_pn, ipn, 6);
1061 
1062 	/* Remove MMIE */
1063 	skb_trim(skb, skb->len - sizeof(*mmie));
1064 
1065 	return RX_CONTINUE;
1066 }
1067 
1068 ieee80211_rx_result
1069 ieee80211_crypto_aes_cmac_256_decrypt(struct ieee80211_rx_data *rx)
1070 {
1071 	struct sk_buff *skb = rx->skb;
1072 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
1073 	struct ieee80211_key *key = rx->key;
1074 	struct ieee80211_mmie_16 *mmie;
1075 	u8 aad[20], mic[16], ipn[6];
1076 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
1077 
1078 	if (!ieee80211_is_mgmt(hdr->frame_control))
1079 		return RX_CONTINUE;
1080 
1081 	/* management frames are already linear */
1082 
1083 	if (skb->len < 24 + sizeof(*mmie))
1084 		return RX_DROP_UNUSABLE;
1085 
1086 	mmie = (struct ieee80211_mmie_16 *)
1087 		(skb->data + skb->len - sizeof(*mmie));
1088 	if (mmie->element_id != WLAN_EID_MMIE ||
1089 	    mmie->length != sizeof(*mmie) - 2)
1090 		return RX_DROP_UNUSABLE; /* Invalid MMIE */
1091 
1092 	bip_ipn_swap(ipn, mmie->sequence_number);
1093 
1094 	if (memcmp(ipn, key->u.aes_cmac.rx_pn, 6) <= 0) {
1095 		key->u.aes_cmac.replays++;
1096 		return RX_DROP_UNUSABLE;
1097 	}
1098 
1099 	if (!(status->flag & RX_FLAG_DECRYPTED)) {
1100 		/* hardware didn't decrypt/verify MIC */
1101 		bip_aad(skb, aad);
1102 		ieee80211_aes_cmac_256(key->u.aes_cmac.tfm, aad,
1103 				       skb->data + 24, skb->len - 24, mic);
1104 		if (memcmp(mic, mmie->mic, sizeof(mmie->mic)) != 0) {
1105 			key->u.aes_cmac.icverrors++;
1106 			return RX_DROP_UNUSABLE;
1107 		}
1108 	}
1109 
1110 	memcpy(key->u.aes_cmac.rx_pn, ipn, 6);
1111 
1112 	/* Remove MMIE */
1113 	skb_trim(skb, skb->len - sizeof(*mmie));
1114 
1115 	return RX_CONTINUE;
1116 }
1117 
1118 ieee80211_tx_result
1119 ieee80211_crypto_aes_gmac_encrypt(struct ieee80211_tx_data *tx)
1120 {
1121 	struct sk_buff *skb;
1122 	struct ieee80211_tx_info *info;
1123 	struct ieee80211_key *key = tx->key;
1124 	struct ieee80211_mmie_16 *mmie;
1125 	struct ieee80211_hdr *hdr;
1126 	u8 aad[20];
1127 	u64 pn64;
1128 	u8 nonce[12];
1129 
1130 	if (WARN_ON(skb_queue_len(&tx->skbs) != 1))
1131 		return TX_DROP;
1132 
1133 	skb = skb_peek(&tx->skbs);
1134 
1135 	info = IEEE80211_SKB_CB(skb);
1136 
1137 	if (info->control.hw_key)
1138 		return TX_CONTINUE;
1139 
1140 	if (WARN_ON(skb_tailroom(skb) < sizeof(*mmie)))
1141 		return TX_DROP;
1142 
1143 	mmie = (struct ieee80211_mmie_16 *)skb_put(skb, sizeof(*mmie));
1144 	mmie->element_id = WLAN_EID_MMIE;
1145 	mmie->length = sizeof(*mmie) - 2;
1146 	mmie->key_id = cpu_to_le16(key->conf.keyidx);
1147 
1148 	/* PN = PN + 1 */
1149 	pn64 = atomic64_inc_return(&key->conf.tx_pn);
1150 
1151 	bip_ipn_set64(mmie->sequence_number, pn64);
1152 
1153 	bip_aad(skb, aad);
1154 
1155 	hdr = (struct ieee80211_hdr *)skb->data;
1156 	memcpy(nonce, hdr->addr2, ETH_ALEN);
1157 	bip_ipn_swap(nonce + ETH_ALEN, mmie->sequence_number);
1158 
1159 	/* MIC = AES-GMAC(IGTK, AAD || Management Frame Body || MMIE, 128) */
1160 	if (ieee80211_aes_gmac(key->u.aes_gmac.tfm, aad, nonce,
1161 			       skb->data + 24, skb->len - 24, mmie->mic) < 0)
1162 		return TX_DROP;
1163 
1164 	return TX_CONTINUE;
1165 }
1166 
1167 ieee80211_rx_result
1168 ieee80211_crypto_aes_gmac_decrypt(struct ieee80211_rx_data *rx)
1169 {
1170 	struct sk_buff *skb = rx->skb;
1171 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
1172 	struct ieee80211_key *key = rx->key;
1173 	struct ieee80211_mmie_16 *mmie;
1174 	u8 aad[20], mic[16], ipn[6], nonce[12];
1175 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
1176 
1177 	if (!ieee80211_is_mgmt(hdr->frame_control))
1178 		return RX_CONTINUE;
1179 
1180 	/* management frames are already linear */
1181 
1182 	if (skb->len < 24 + sizeof(*mmie))
1183 		return RX_DROP_UNUSABLE;
1184 
1185 	mmie = (struct ieee80211_mmie_16 *)
1186 		(skb->data + skb->len - sizeof(*mmie));
1187 	if (mmie->element_id != WLAN_EID_MMIE ||
1188 	    mmie->length != sizeof(*mmie) - 2)
1189 		return RX_DROP_UNUSABLE; /* Invalid MMIE */
1190 
1191 	bip_ipn_swap(ipn, mmie->sequence_number);
1192 
1193 	if (memcmp(ipn, key->u.aes_gmac.rx_pn, 6) <= 0) {
1194 		key->u.aes_gmac.replays++;
1195 		return RX_DROP_UNUSABLE;
1196 	}
1197 
1198 	if (!(status->flag & RX_FLAG_DECRYPTED)) {
1199 		/* hardware didn't decrypt/verify MIC */
1200 		bip_aad(skb, aad);
1201 
1202 		memcpy(nonce, hdr->addr2, ETH_ALEN);
1203 		memcpy(nonce + ETH_ALEN, ipn, 6);
1204 
1205 		if (ieee80211_aes_gmac(key->u.aes_gmac.tfm, aad, nonce,
1206 				       skb->data + 24, skb->len - 24,
1207 				       mic) < 0 ||
1208 		    memcmp(mic, mmie->mic, sizeof(mmie->mic)) != 0) {
1209 			key->u.aes_gmac.icverrors++;
1210 			return RX_DROP_UNUSABLE;
1211 		}
1212 	}
1213 
1214 	memcpy(key->u.aes_gmac.rx_pn, ipn, 6);
1215 
1216 	/* Remove MMIE */
1217 	skb_trim(skb, skb->len - sizeof(*mmie));
1218 
1219 	return RX_CONTINUE;
1220 }
1221 
1222 ieee80211_tx_result
1223 ieee80211_crypto_hw_encrypt(struct ieee80211_tx_data *tx)
1224 {
1225 	struct sk_buff *skb;
1226 	struct ieee80211_tx_info *info = NULL;
1227 	ieee80211_tx_result res;
1228 
1229 	skb_queue_walk(&tx->skbs, skb) {
1230 		info  = IEEE80211_SKB_CB(skb);
1231 
1232 		/* handle hw-only algorithm */
1233 		if (!info->control.hw_key)
1234 			return TX_DROP;
1235 
1236 		if (tx->key->flags & KEY_FLAG_CIPHER_SCHEME) {
1237 			res = ieee80211_crypto_cs_encrypt(tx, skb);
1238 			if (res != TX_CONTINUE)
1239 				return res;
1240 		}
1241 	}
1242 
1243 	ieee80211_tx_set_protected(tx);
1244 
1245 	return TX_CONTINUE;
1246 }
1247 
1248 ieee80211_rx_result
1249 ieee80211_crypto_hw_decrypt(struct ieee80211_rx_data *rx)
1250 {
1251 	if (rx->sta && rx->sta->cipher_scheme)
1252 		return ieee80211_crypto_cs_decrypt(rx);
1253 
1254 	return RX_DROP_UNUSABLE;
1255 }
1256