xref: /openbmc/linux/net/mac80211/wpa.c (revision 22d55f02)
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  */
7 
8 #include <linux/netdevice.h>
9 #include <linux/types.h>
10 #include <linux/skbuff.h>
11 #include <linux/compiler.h>
12 #include <linux/ieee80211.h>
13 #include <linux/gfp.h>
14 #include <asm/unaligned.h>
15 #include <net/mac80211.h>
16 #include <crypto/aes.h>
17 #include <crypto/algapi.h>
18 
19 #include "ieee80211_i.h"
20 #include "michael.h"
21 #include "tkip.h"
22 #include "aes_ccm.h"
23 #include "aes_cmac.h"
24 #include "aes_gmac.h"
25 #include "aes_gcm.h"
26 #include "wpa.h"
27 
28 ieee80211_tx_result
29 ieee80211_tx_h_michael_mic_add(struct ieee80211_tx_data *tx)
30 {
31 	u8 *data, *key, *mic;
32 	size_t data_len;
33 	unsigned int hdrlen;
34 	struct ieee80211_hdr *hdr;
35 	struct sk_buff *skb = tx->skb;
36 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
37 	int tail;
38 
39 	hdr = (struct ieee80211_hdr *)skb->data;
40 	if (!tx->key || tx->key->conf.cipher != WLAN_CIPHER_SUITE_TKIP ||
41 	    skb->len < 24 || !ieee80211_is_data_present(hdr->frame_control))
42 		return TX_CONTINUE;
43 
44 	hdrlen = ieee80211_hdrlen(hdr->frame_control);
45 	if (skb->len < hdrlen)
46 		return TX_DROP;
47 
48 	data = skb->data + hdrlen;
49 	data_len = skb->len - hdrlen;
50 
51 	if (unlikely(info->flags & IEEE80211_TX_INTFL_TKIP_MIC_FAILURE)) {
52 		/* Need to use software crypto for the test */
53 		info->control.hw_key = NULL;
54 	}
55 
56 	if (info->control.hw_key &&
57 	    (info->flags & IEEE80211_TX_CTL_DONTFRAG ||
58 	     ieee80211_hw_check(&tx->local->hw, SUPPORTS_TX_FRAG)) &&
59 	    !(tx->key->conf.flags & (IEEE80211_KEY_FLAG_GENERATE_MMIC |
60 				     IEEE80211_KEY_FLAG_PUT_MIC_SPACE))) {
61 		/* hwaccel - with no need for SW-generated MMIC or MIC space */
62 		return TX_CONTINUE;
63 	}
64 
65 	tail = MICHAEL_MIC_LEN;
66 	if (!info->control.hw_key)
67 		tail += IEEE80211_TKIP_ICV_LEN;
68 
69 	if (WARN(skb_tailroom(skb) < tail ||
70 		 skb_headroom(skb) < IEEE80211_TKIP_IV_LEN,
71 		 "mmic: not enough head/tail (%d/%d,%d/%d)\n",
72 		 skb_headroom(skb), IEEE80211_TKIP_IV_LEN,
73 		 skb_tailroom(skb), tail))
74 		return TX_DROP;
75 
76 	mic = skb_put(skb, MICHAEL_MIC_LEN);
77 
78 	if (tx->key->conf.flags & IEEE80211_KEY_FLAG_PUT_MIC_SPACE) {
79 		/* Zeroed MIC can help with debug */
80 		memset(mic, 0, MICHAEL_MIC_LEN);
81 		return TX_CONTINUE;
82 	}
83 
84 	key = &tx->key->conf.key[NL80211_TKIP_DATA_OFFSET_TX_MIC_KEY];
85 	michael_mic(key, hdr, data, data_len, mic);
86 	if (unlikely(info->flags & IEEE80211_TX_INTFL_TKIP_MIC_FAILURE))
87 		mic[0]++;
88 
89 	return TX_CONTINUE;
90 }
91 
92 
93 ieee80211_rx_result
94 ieee80211_rx_h_michael_mic_verify(struct ieee80211_rx_data *rx)
95 {
96 	u8 *data, *key = NULL;
97 	size_t data_len;
98 	unsigned int hdrlen;
99 	u8 mic[MICHAEL_MIC_LEN];
100 	struct sk_buff *skb = rx->skb;
101 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
102 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
103 
104 	/*
105 	 * it makes no sense to check for MIC errors on anything other
106 	 * than data frames.
107 	 */
108 	if (!ieee80211_is_data_present(hdr->frame_control))
109 		return RX_CONTINUE;
110 
111 	/*
112 	 * No way to verify the MIC if the hardware stripped it or
113 	 * the IV with the key index. In this case we have solely rely
114 	 * on the driver to set RX_FLAG_MMIC_ERROR in the event of a
115 	 * MIC failure report.
116 	 */
117 	if (status->flag & (RX_FLAG_MMIC_STRIPPED | RX_FLAG_IV_STRIPPED)) {
118 		if (status->flag & RX_FLAG_MMIC_ERROR)
119 			goto mic_fail_no_key;
120 
121 		if (!(status->flag & RX_FLAG_IV_STRIPPED) && rx->key &&
122 		    rx->key->conf.cipher == WLAN_CIPHER_SUITE_TKIP)
123 			goto update_iv;
124 
125 		return RX_CONTINUE;
126 	}
127 
128 	/*
129 	 * Some hardware seems to generate Michael MIC failure reports; even
130 	 * though, the frame was not encrypted with TKIP and therefore has no
131 	 * MIC. Ignore the flag them to avoid triggering countermeasures.
132 	 */
133 	if (!rx->key || rx->key->conf.cipher != WLAN_CIPHER_SUITE_TKIP ||
134 	    !(status->flag & RX_FLAG_DECRYPTED))
135 		return RX_CONTINUE;
136 
137 	if (rx->sdata->vif.type == NL80211_IFTYPE_AP && rx->key->conf.keyidx) {
138 		/*
139 		 * APs with pairwise keys should never receive Michael MIC
140 		 * errors for non-zero keyidx because these are reserved for
141 		 * group keys and only the AP is sending real multicast
142 		 * frames in the BSS.
143 		 */
144 		return RX_DROP_UNUSABLE;
145 	}
146 
147 	if (status->flag & RX_FLAG_MMIC_ERROR)
148 		goto mic_fail;
149 
150 	hdrlen = ieee80211_hdrlen(hdr->frame_control);
151 	if (skb->len < hdrlen + MICHAEL_MIC_LEN)
152 		return RX_DROP_UNUSABLE;
153 
154 	if (skb_linearize(rx->skb))
155 		return RX_DROP_UNUSABLE;
156 	hdr = (void *)skb->data;
157 
158 	data = skb->data + hdrlen;
159 	data_len = skb->len - hdrlen - MICHAEL_MIC_LEN;
160 	key = &rx->key->conf.key[NL80211_TKIP_DATA_OFFSET_RX_MIC_KEY];
161 	michael_mic(key, hdr, data, data_len, mic);
162 	if (crypto_memneq(mic, data + data_len, MICHAEL_MIC_LEN))
163 		goto mic_fail;
164 
165 	/* remove Michael MIC from payload */
166 	skb_trim(skb, skb->len - MICHAEL_MIC_LEN);
167 
168 update_iv:
169 	/* update IV in key information to be able to detect replays */
170 	rx->key->u.tkip.rx[rx->security_idx].iv32 = rx->tkip_iv32;
171 	rx->key->u.tkip.rx[rx->security_idx].iv16 = rx->tkip_iv16;
172 
173 	return RX_CONTINUE;
174 
175 mic_fail:
176 	rx->key->u.tkip.mic_failures++;
177 
178 mic_fail_no_key:
179 	/*
180 	 * In some cases the key can be unset - e.g. a multicast packet, in
181 	 * a driver that supports HW encryption. Send up the key idx only if
182 	 * the key is set.
183 	 */
184 	cfg80211_michael_mic_failure(rx->sdata->dev, hdr->addr2,
185 				     is_multicast_ether_addr(hdr->addr1) ?
186 				     NL80211_KEYTYPE_GROUP :
187 				     NL80211_KEYTYPE_PAIRWISE,
188 				     rx->key ? rx->key->conf.keyidx : -1,
189 				     NULL, GFP_ATOMIC);
190 	return RX_DROP_UNUSABLE;
191 }
192 
193 static int tkip_encrypt_skb(struct ieee80211_tx_data *tx, struct sk_buff *skb)
194 {
195 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
196 	struct ieee80211_key *key = tx->key;
197 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
198 	unsigned int hdrlen;
199 	int len, tail;
200 	u64 pn;
201 	u8 *pos;
202 
203 	if (info->control.hw_key &&
204 	    !(info->control.hw_key->flags & IEEE80211_KEY_FLAG_GENERATE_IV) &&
205 	    !(info->control.hw_key->flags & IEEE80211_KEY_FLAG_PUT_IV_SPACE)) {
206 		/* hwaccel - with no need for software-generated IV */
207 		return 0;
208 	}
209 
210 	hdrlen = ieee80211_hdrlen(hdr->frame_control);
211 	len = skb->len - hdrlen;
212 
213 	if (info->control.hw_key)
214 		tail = 0;
215 	else
216 		tail = IEEE80211_TKIP_ICV_LEN;
217 
218 	if (WARN_ON(skb_tailroom(skb) < tail ||
219 		    skb_headroom(skb) < IEEE80211_TKIP_IV_LEN))
220 		return -1;
221 
222 	pos = skb_push(skb, IEEE80211_TKIP_IV_LEN);
223 	memmove(pos, pos + IEEE80211_TKIP_IV_LEN, hdrlen);
224 	pos += hdrlen;
225 
226 	/* the HW only needs room for the IV, but not the actual IV */
227 	if (info->control.hw_key &&
228 	    (info->control.hw_key->flags & IEEE80211_KEY_FLAG_PUT_IV_SPACE))
229 		return 0;
230 
231 	/* Increase IV for the frame */
232 	pn = atomic64_inc_return(&key->conf.tx_pn);
233 	pos = ieee80211_tkip_add_iv(pos, &key->conf, pn);
234 
235 	/* hwaccel - with software IV */
236 	if (info->control.hw_key)
237 		return 0;
238 
239 	/* Add room for ICV */
240 	skb_put(skb, IEEE80211_TKIP_ICV_LEN);
241 
242 	return ieee80211_tkip_encrypt_data(tx->local->wep_tx_tfm,
243 					   key, skb, pos, len);
244 }
245 
246 
247 ieee80211_tx_result
248 ieee80211_crypto_tkip_encrypt(struct ieee80211_tx_data *tx)
249 {
250 	struct sk_buff *skb;
251 
252 	ieee80211_tx_set_protected(tx);
253 
254 	skb_queue_walk(&tx->skbs, skb) {
255 		if (tkip_encrypt_skb(tx, skb) < 0)
256 			return TX_DROP;
257 	}
258 
259 	return TX_CONTINUE;
260 }
261 
262 
263 ieee80211_rx_result
264 ieee80211_crypto_tkip_decrypt(struct ieee80211_rx_data *rx)
265 {
266 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) rx->skb->data;
267 	int hdrlen, res, hwaccel = 0;
268 	struct ieee80211_key *key = rx->key;
269 	struct sk_buff *skb = rx->skb;
270 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
271 
272 	hdrlen = ieee80211_hdrlen(hdr->frame_control);
273 
274 	if (!ieee80211_is_data(hdr->frame_control))
275 		return RX_CONTINUE;
276 
277 	if (!rx->sta || skb->len - hdrlen < 12)
278 		return RX_DROP_UNUSABLE;
279 
280 	/* it may be possible to optimize this a bit more */
281 	if (skb_linearize(rx->skb))
282 		return RX_DROP_UNUSABLE;
283 	hdr = (void *)skb->data;
284 
285 	/*
286 	 * Let TKIP code verify IV, but skip decryption.
287 	 * In the case where hardware checks the IV as well,
288 	 * we don't even get here, see ieee80211_rx_h_decrypt()
289 	 */
290 	if (status->flag & RX_FLAG_DECRYPTED)
291 		hwaccel = 1;
292 
293 	res = ieee80211_tkip_decrypt_data(rx->local->wep_rx_tfm,
294 					  key, skb->data + hdrlen,
295 					  skb->len - hdrlen, rx->sta->sta.addr,
296 					  hdr->addr1, hwaccel, rx->security_idx,
297 					  &rx->tkip_iv32,
298 					  &rx->tkip_iv16);
299 	if (res != TKIP_DECRYPT_OK)
300 		return RX_DROP_UNUSABLE;
301 
302 	/* Trim ICV */
303 	if (!(status->flag & RX_FLAG_ICV_STRIPPED))
304 		skb_trim(skb, skb->len - IEEE80211_TKIP_ICV_LEN);
305 
306 	/* Remove IV */
307 	memmove(skb->data + IEEE80211_TKIP_IV_LEN, skb->data, hdrlen);
308 	skb_pull(skb, IEEE80211_TKIP_IV_LEN);
309 
310 	return RX_CONTINUE;
311 }
312 
313 
314 static void ccmp_special_blocks(struct sk_buff *skb, u8 *pn, u8 *b_0, u8 *aad)
315 {
316 	__le16 mask_fc;
317 	int a4_included, mgmt;
318 	u8 qos_tid;
319 	u16 len_a;
320 	unsigned int hdrlen;
321 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
322 
323 	/*
324 	 * Mask FC: zero subtype b4 b5 b6 (if not mgmt)
325 	 * Retry, PwrMgt, MoreData; set Protected
326 	 */
327 	mgmt = ieee80211_is_mgmt(hdr->frame_control);
328 	mask_fc = hdr->frame_control;
329 	mask_fc &= ~cpu_to_le16(IEEE80211_FCTL_RETRY |
330 				IEEE80211_FCTL_PM | IEEE80211_FCTL_MOREDATA);
331 	if (!mgmt)
332 		mask_fc &= ~cpu_to_le16(0x0070);
333 	mask_fc |= cpu_to_le16(IEEE80211_FCTL_PROTECTED);
334 
335 	hdrlen = ieee80211_hdrlen(hdr->frame_control);
336 	len_a = hdrlen - 2;
337 	a4_included = ieee80211_has_a4(hdr->frame_control);
338 
339 	if (ieee80211_is_data_qos(hdr->frame_control))
340 		qos_tid = ieee80211_get_tid(hdr);
341 	else
342 		qos_tid = 0;
343 
344 	/* In CCM, the initial vectors (IV) used for CTR mode encryption and CBC
345 	 * mode authentication are not allowed to collide, yet both are derived
346 	 * from this vector b_0. We only set L := 1 here to indicate that the
347 	 * data size can be represented in (L+1) bytes. The CCM layer will take
348 	 * care of storing the data length in the top (L+1) bytes and setting
349 	 * and clearing the other bits as is required to derive the two IVs.
350 	 */
351 	b_0[0] = 0x1;
352 
353 	/* Nonce: Nonce Flags | A2 | PN
354 	 * Nonce Flags: Priority (b0..b3) | Management (b4) | Reserved (b5..b7)
355 	 */
356 	b_0[1] = qos_tid | (mgmt << 4);
357 	memcpy(&b_0[2], hdr->addr2, ETH_ALEN);
358 	memcpy(&b_0[8], pn, IEEE80211_CCMP_PN_LEN);
359 
360 	/* AAD (extra authenticate-only data) / masked 802.11 header
361 	 * FC | A1 | A2 | A3 | SC | [A4] | [QC] */
362 	put_unaligned_be16(len_a, &aad[0]);
363 	put_unaligned(mask_fc, (__le16 *)&aad[2]);
364 	memcpy(&aad[4], &hdr->addr1, 3 * ETH_ALEN);
365 
366 	/* Mask Seq#, leave Frag# */
367 	aad[22] = *((u8 *) &hdr->seq_ctrl) & 0x0f;
368 	aad[23] = 0;
369 
370 	if (a4_included) {
371 		memcpy(&aad[24], hdr->addr4, ETH_ALEN);
372 		aad[30] = qos_tid;
373 		aad[31] = 0;
374 	} else {
375 		memset(&aad[24], 0, ETH_ALEN + IEEE80211_QOS_CTL_LEN);
376 		aad[24] = qos_tid;
377 	}
378 }
379 
380 
381 static inline void ccmp_pn2hdr(u8 *hdr, u8 *pn, int key_id)
382 {
383 	hdr[0] = pn[5];
384 	hdr[1] = pn[4];
385 	hdr[2] = 0;
386 	hdr[3] = 0x20 | (key_id << 6);
387 	hdr[4] = pn[3];
388 	hdr[5] = pn[2];
389 	hdr[6] = pn[1];
390 	hdr[7] = pn[0];
391 }
392 
393 
394 static inline void ccmp_hdr2pn(u8 *pn, u8 *hdr)
395 {
396 	pn[0] = hdr[7];
397 	pn[1] = hdr[6];
398 	pn[2] = hdr[5];
399 	pn[3] = hdr[4];
400 	pn[4] = hdr[1];
401 	pn[5] = hdr[0];
402 }
403 
404 
405 static int ccmp_encrypt_skb(struct ieee80211_tx_data *tx, struct sk_buff *skb,
406 			    unsigned int mic_len)
407 {
408 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
409 	struct ieee80211_key *key = tx->key;
410 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
411 	int hdrlen, len, tail;
412 	u8 *pos;
413 	u8 pn[6];
414 	u64 pn64;
415 	u8 aad[CCM_AAD_LEN];
416 	u8 b_0[AES_BLOCK_SIZE];
417 
418 	if (info->control.hw_key &&
419 	    !(info->control.hw_key->flags & IEEE80211_KEY_FLAG_GENERATE_IV) &&
420 	    !(info->control.hw_key->flags & IEEE80211_KEY_FLAG_PUT_IV_SPACE) &&
421 	    !((info->control.hw_key->flags &
422 	       IEEE80211_KEY_FLAG_GENERATE_IV_MGMT) &&
423 	      ieee80211_is_mgmt(hdr->frame_control))) {
424 		/*
425 		 * hwaccel has no need for preallocated room for CCMP
426 		 * header or MIC fields
427 		 */
428 		return 0;
429 	}
430 
431 	hdrlen = ieee80211_hdrlen(hdr->frame_control);
432 	len = skb->len - hdrlen;
433 
434 	if (info->control.hw_key)
435 		tail = 0;
436 	else
437 		tail = mic_len;
438 
439 	if (WARN_ON(skb_tailroom(skb) < tail ||
440 		    skb_headroom(skb) < IEEE80211_CCMP_HDR_LEN))
441 		return -1;
442 
443 	pos = skb_push(skb, IEEE80211_CCMP_HDR_LEN);
444 	memmove(pos, pos + IEEE80211_CCMP_HDR_LEN, hdrlen);
445 
446 	/* the HW only needs room for the IV, but not the actual IV */
447 	if (info->control.hw_key &&
448 	    (info->control.hw_key->flags & IEEE80211_KEY_FLAG_PUT_IV_SPACE))
449 		return 0;
450 
451 	hdr = (struct ieee80211_hdr *) pos;
452 	pos += hdrlen;
453 
454 	pn64 = atomic64_inc_return(&key->conf.tx_pn);
455 
456 	pn[5] = pn64;
457 	pn[4] = pn64 >> 8;
458 	pn[3] = pn64 >> 16;
459 	pn[2] = pn64 >> 24;
460 	pn[1] = pn64 >> 32;
461 	pn[0] = pn64 >> 40;
462 
463 	ccmp_pn2hdr(pos, pn, key->conf.keyidx);
464 
465 	/* hwaccel - with software CCMP header */
466 	if (info->control.hw_key)
467 		return 0;
468 
469 	pos += IEEE80211_CCMP_HDR_LEN;
470 	ccmp_special_blocks(skb, pn, b_0, aad);
471 	return ieee80211_aes_ccm_encrypt(key->u.ccmp.tfm, b_0, aad, pos, len,
472 					 skb_put(skb, mic_len));
473 }
474 
475 
476 ieee80211_tx_result
477 ieee80211_crypto_ccmp_encrypt(struct ieee80211_tx_data *tx,
478 			      unsigned int mic_len)
479 {
480 	struct sk_buff *skb;
481 
482 	ieee80211_tx_set_protected(tx);
483 
484 	skb_queue_walk(&tx->skbs, skb) {
485 		if (ccmp_encrypt_skb(tx, skb, mic_len) < 0)
486 			return TX_DROP;
487 	}
488 
489 	return TX_CONTINUE;
490 }
491 
492 
493 ieee80211_rx_result
494 ieee80211_crypto_ccmp_decrypt(struct ieee80211_rx_data *rx,
495 			      unsigned int mic_len)
496 {
497 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
498 	int hdrlen;
499 	struct ieee80211_key *key = rx->key;
500 	struct sk_buff *skb = rx->skb;
501 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
502 	u8 pn[IEEE80211_CCMP_PN_LEN];
503 	int data_len;
504 	int queue;
505 
506 	hdrlen = ieee80211_hdrlen(hdr->frame_control);
507 
508 	if (!ieee80211_is_data(hdr->frame_control) &&
509 	    !ieee80211_is_robust_mgmt_frame(skb))
510 		return RX_CONTINUE;
511 
512 	if (status->flag & RX_FLAG_DECRYPTED) {
513 		if (!pskb_may_pull(rx->skb, hdrlen + IEEE80211_CCMP_HDR_LEN))
514 			return RX_DROP_UNUSABLE;
515 		if (status->flag & RX_FLAG_MIC_STRIPPED)
516 			mic_len = 0;
517 	} else {
518 		if (skb_linearize(rx->skb))
519 			return RX_DROP_UNUSABLE;
520 	}
521 
522 	data_len = skb->len - hdrlen - IEEE80211_CCMP_HDR_LEN - mic_len;
523 	if (!rx->sta || data_len < 0)
524 		return RX_DROP_UNUSABLE;
525 
526 	if (!(status->flag & RX_FLAG_PN_VALIDATED)) {
527 		int res;
528 
529 		ccmp_hdr2pn(pn, skb->data + hdrlen);
530 
531 		queue = rx->security_idx;
532 
533 		res = memcmp(pn, key->u.ccmp.rx_pn[queue],
534 			     IEEE80211_CCMP_PN_LEN);
535 		if (res < 0 ||
536 		    (!res && !(status->flag & RX_FLAG_ALLOW_SAME_PN))) {
537 			key->u.ccmp.replays++;
538 			return RX_DROP_UNUSABLE;
539 		}
540 
541 		if (!(status->flag & RX_FLAG_DECRYPTED)) {
542 			u8 aad[2 * AES_BLOCK_SIZE];
543 			u8 b_0[AES_BLOCK_SIZE];
544 			/* hardware didn't decrypt/verify MIC */
545 			ccmp_special_blocks(skb, pn, b_0, aad);
546 
547 			if (ieee80211_aes_ccm_decrypt(
548 				    key->u.ccmp.tfm, b_0, aad,
549 				    skb->data + hdrlen + IEEE80211_CCMP_HDR_LEN,
550 				    data_len,
551 				    skb->data + skb->len - mic_len))
552 				return RX_DROP_UNUSABLE;
553 		}
554 
555 		memcpy(key->u.ccmp.rx_pn[queue], pn, IEEE80211_CCMP_PN_LEN);
556 	}
557 
558 	/* Remove CCMP header and MIC */
559 	if (pskb_trim(skb, skb->len - mic_len))
560 		return RX_DROP_UNUSABLE;
561 	memmove(skb->data + IEEE80211_CCMP_HDR_LEN, skb->data, hdrlen);
562 	skb_pull(skb, IEEE80211_CCMP_HDR_LEN);
563 
564 	return RX_CONTINUE;
565 }
566 
567 static void gcmp_special_blocks(struct sk_buff *skb, u8 *pn, u8 *j_0, u8 *aad)
568 {
569 	__le16 mask_fc;
570 	u8 qos_tid;
571 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
572 
573 	memcpy(j_0, hdr->addr2, ETH_ALEN);
574 	memcpy(&j_0[ETH_ALEN], pn, IEEE80211_GCMP_PN_LEN);
575 	j_0[13] = 0;
576 	j_0[14] = 0;
577 	j_0[AES_BLOCK_SIZE - 1] = 0x01;
578 
579 	/* AAD (extra authenticate-only data) / masked 802.11 header
580 	 * FC | A1 | A2 | A3 | SC | [A4] | [QC]
581 	 */
582 	put_unaligned_be16(ieee80211_hdrlen(hdr->frame_control) - 2, &aad[0]);
583 	/* Mask FC: zero subtype b4 b5 b6 (if not mgmt)
584 	 * Retry, PwrMgt, MoreData; set Protected
585 	 */
586 	mask_fc = hdr->frame_control;
587 	mask_fc &= ~cpu_to_le16(IEEE80211_FCTL_RETRY |
588 				IEEE80211_FCTL_PM | IEEE80211_FCTL_MOREDATA);
589 	if (!ieee80211_is_mgmt(hdr->frame_control))
590 		mask_fc &= ~cpu_to_le16(0x0070);
591 	mask_fc |= cpu_to_le16(IEEE80211_FCTL_PROTECTED);
592 
593 	put_unaligned(mask_fc, (__le16 *)&aad[2]);
594 	memcpy(&aad[4], &hdr->addr1, 3 * ETH_ALEN);
595 
596 	/* Mask Seq#, leave Frag# */
597 	aad[22] = *((u8 *)&hdr->seq_ctrl) & 0x0f;
598 	aad[23] = 0;
599 
600 	if (ieee80211_is_data_qos(hdr->frame_control))
601 		qos_tid = ieee80211_get_tid(hdr);
602 	else
603 		qos_tid = 0;
604 
605 	if (ieee80211_has_a4(hdr->frame_control)) {
606 		memcpy(&aad[24], hdr->addr4, ETH_ALEN);
607 		aad[30] = qos_tid;
608 		aad[31] = 0;
609 	} else {
610 		memset(&aad[24], 0, ETH_ALEN + IEEE80211_QOS_CTL_LEN);
611 		aad[24] = qos_tid;
612 	}
613 }
614 
615 static inline void gcmp_pn2hdr(u8 *hdr, const u8 *pn, int key_id)
616 {
617 	hdr[0] = pn[5];
618 	hdr[1] = pn[4];
619 	hdr[2] = 0;
620 	hdr[3] = 0x20 | (key_id << 6);
621 	hdr[4] = pn[3];
622 	hdr[5] = pn[2];
623 	hdr[6] = pn[1];
624 	hdr[7] = pn[0];
625 }
626 
627 static inline void gcmp_hdr2pn(u8 *pn, const u8 *hdr)
628 {
629 	pn[0] = hdr[7];
630 	pn[1] = hdr[6];
631 	pn[2] = hdr[5];
632 	pn[3] = hdr[4];
633 	pn[4] = hdr[1];
634 	pn[5] = hdr[0];
635 }
636 
637 static int gcmp_encrypt_skb(struct ieee80211_tx_data *tx, struct sk_buff *skb)
638 {
639 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
640 	struct ieee80211_key *key = tx->key;
641 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
642 	int hdrlen, len, tail;
643 	u8 *pos;
644 	u8 pn[6];
645 	u64 pn64;
646 	u8 aad[GCM_AAD_LEN];
647 	u8 j_0[AES_BLOCK_SIZE];
648 
649 	if (info->control.hw_key &&
650 	    !(info->control.hw_key->flags & IEEE80211_KEY_FLAG_GENERATE_IV) &&
651 	    !(info->control.hw_key->flags & IEEE80211_KEY_FLAG_PUT_IV_SPACE) &&
652 	    !((info->control.hw_key->flags &
653 	       IEEE80211_KEY_FLAG_GENERATE_IV_MGMT) &&
654 	      ieee80211_is_mgmt(hdr->frame_control))) {
655 		/* hwaccel has no need for preallocated room for GCMP
656 		 * header or MIC fields
657 		 */
658 		return 0;
659 	}
660 
661 	hdrlen = ieee80211_hdrlen(hdr->frame_control);
662 	len = skb->len - hdrlen;
663 
664 	if (info->control.hw_key)
665 		tail = 0;
666 	else
667 		tail = IEEE80211_GCMP_MIC_LEN;
668 
669 	if (WARN_ON(skb_tailroom(skb) < tail ||
670 		    skb_headroom(skb) < IEEE80211_GCMP_HDR_LEN))
671 		return -1;
672 
673 	pos = skb_push(skb, IEEE80211_GCMP_HDR_LEN);
674 	memmove(pos, pos + IEEE80211_GCMP_HDR_LEN, hdrlen);
675 	skb_set_network_header(skb, skb_network_offset(skb) +
676 				    IEEE80211_GCMP_HDR_LEN);
677 
678 	/* the HW only needs room for the IV, but not the actual IV */
679 	if (info->control.hw_key &&
680 	    (info->control.hw_key->flags & IEEE80211_KEY_FLAG_PUT_IV_SPACE))
681 		return 0;
682 
683 	hdr = (struct ieee80211_hdr *)pos;
684 	pos += hdrlen;
685 
686 	pn64 = atomic64_inc_return(&key->conf.tx_pn);
687 
688 	pn[5] = pn64;
689 	pn[4] = pn64 >> 8;
690 	pn[3] = pn64 >> 16;
691 	pn[2] = pn64 >> 24;
692 	pn[1] = pn64 >> 32;
693 	pn[0] = pn64 >> 40;
694 
695 	gcmp_pn2hdr(pos, pn, key->conf.keyidx);
696 
697 	/* hwaccel - with software GCMP header */
698 	if (info->control.hw_key)
699 		return 0;
700 
701 	pos += IEEE80211_GCMP_HDR_LEN;
702 	gcmp_special_blocks(skb, pn, j_0, aad);
703 	return ieee80211_aes_gcm_encrypt(key->u.gcmp.tfm, j_0, aad, pos, len,
704 					 skb_put(skb, IEEE80211_GCMP_MIC_LEN));
705 }
706 
707 ieee80211_tx_result
708 ieee80211_crypto_gcmp_encrypt(struct ieee80211_tx_data *tx)
709 {
710 	struct sk_buff *skb;
711 
712 	ieee80211_tx_set_protected(tx);
713 
714 	skb_queue_walk(&tx->skbs, skb) {
715 		if (gcmp_encrypt_skb(tx, skb) < 0)
716 			return TX_DROP;
717 	}
718 
719 	return TX_CONTINUE;
720 }
721 
722 ieee80211_rx_result
723 ieee80211_crypto_gcmp_decrypt(struct ieee80211_rx_data *rx)
724 {
725 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
726 	int hdrlen;
727 	struct ieee80211_key *key = rx->key;
728 	struct sk_buff *skb = rx->skb;
729 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
730 	u8 pn[IEEE80211_GCMP_PN_LEN];
731 	int data_len, queue, mic_len = IEEE80211_GCMP_MIC_LEN;
732 
733 	hdrlen = ieee80211_hdrlen(hdr->frame_control);
734 
735 	if (!ieee80211_is_data(hdr->frame_control) &&
736 	    !ieee80211_is_robust_mgmt_frame(skb))
737 		return RX_CONTINUE;
738 
739 	if (status->flag & RX_FLAG_DECRYPTED) {
740 		if (!pskb_may_pull(rx->skb, hdrlen + IEEE80211_GCMP_HDR_LEN))
741 			return RX_DROP_UNUSABLE;
742 		if (status->flag & RX_FLAG_MIC_STRIPPED)
743 			mic_len = 0;
744 	} else {
745 		if (skb_linearize(rx->skb))
746 			return RX_DROP_UNUSABLE;
747 	}
748 
749 	data_len = skb->len - hdrlen - IEEE80211_GCMP_HDR_LEN - mic_len;
750 	if (!rx->sta || data_len < 0)
751 		return RX_DROP_UNUSABLE;
752 
753 	if (!(status->flag & RX_FLAG_PN_VALIDATED)) {
754 		int res;
755 
756 		gcmp_hdr2pn(pn, skb->data + hdrlen);
757 
758 		queue = rx->security_idx;
759 
760 		res = memcmp(pn, key->u.gcmp.rx_pn[queue],
761 			     IEEE80211_GCMP_PN_LEN);
762 		if (res < 0 ||
763 		    (!res && !(status->flag & RX_FLAG_ALLOW_SAME_PN))) {
764 			key->u.gcmp.replays++;
765 			return RX_DROP_UNUSABLE;
766 		}
767 
768 		if (!(status->flag & RX_FLAG_DECRYPTED)) {
769 			u8 aad[2 * AES_BLOCK_SIZE];
770 			u8 j_0[AES_BLOCK_SIZE];
771 			/* hardware didn't decrypt/verify MIC */
772 			gcmp_special_blocks(skb, pn, j_0, aad);
773 
774 			if (ieee80211_aes_gcm_decrypt(
775 				    key->u.gcmp.tfm, j_0, aad,
776 				    skb->data + hdrlen + IEEE80211_GCMP_HDR_LEN,
777 				    data_len,
778 				    skb->data + skb->len -
779 				    IEEE80211_GCMP_MIC_LEN))
780 				return RX_DROP_UNUSABLE;
781 		}
782 
783 		memcpy(key->u.gcmp.rx_pn[queue], pn, IEEE80211_GCMP_PN_LEN);
784 	}
785 
786 	/* Remove GCMP header and MIC */
787 	if (pskb_trim(skb, skb->len - mic_len))
788 		return RX_DROP_UNUSABLE;
789 	memmove(skb->data + IEEE80211_GCMP_HDR_LEN, skb->data, hdrlen);
790 	skb_pull(skb, IEEE80211_GCMP_HDR_LEN);
791 
792 	return RX_CONTINUE;
793 }
794 
795 static ieee80211_tx_result
796 ieee80211_crypto_cs_encrypt(struct ieee80211_tx_data *tx,
797 			    struct sk_buff *skb)
798 {
799 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
800 	struct ieee80211_key *key = tx->key;
801 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
802 	int hdrlen;
803 	u8 *pos, iv_len = key->conf.iv_len;
804 
805 	if (info->control.hw_key &&
806 	    !(info->control.hw_key->flags & IEEE80211_KEY_FLAG_PUT_IV_SPACE)) {
807 		/* hwaccel has no need for preallocated head room */
808 		return TX_CONTINUE;
809 	}
810 
811 	if (unlikely(skb_headroom(skb) < iv_len &&
812 		     pskb_expand_head(skb, iv_len, 0, GFP_ATOMIC)))
813 		return TX_DROP;
814 
815 	hdrlen = ieee80211_hdrlen(hdr->frame_control);
816 
817 	pos = skb_push(skb, iv_len);
818 	memmove(pos, pos + iv_len, hdrlen);
819 
820 	return TX_CONTINUE;
821 }
822 
823 static inline int ieee80211_crypto_cs_pn_compare(u8 *pn1, u8 *pn2, int len)
824 {
825 	int i;
826 
827 	/* pn is little endian */
828 	for (i = len - 1; i >= 0; i--) {
829 		if (pn1[i] < pn2[i])
830 			return -1;
831 		else if (pn1[i] > pn2[i])
832 			return 1;
833 	}
834 
835 	return 0;
836 }
837 
838 static ieee80211_rx_result
839 ieee80211_crypto_cs_decrypt(struct ieee80211_rx_data *rx)
840 {
841 	struct ieee80211_key *key = rx->key;
842 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
843 	const struct ieee80211_cipher_scheme *cs = NULL;
844 	int hdrlen = ieee80211_hdrlen(hdr->frame_control);
845 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
846 	int data_len;
847 	u8 *rx_pn;
848 	u8 *skb_pn;
849 	u8 qos_tid;
850 
851 	if (!rx->sta || !rx->sta->cipher_scheme ||
852 	    !(status->flag & RX_FLAG_DECRYPTED))
853 		return RX_DROP_UNUSABLE;
854 
855 	if (!ieee80211_is_data(hdr->frame_control))
856 		return RX_CONTINUE;
857 
858 	cs = rx->sta->cipher_scheme;
859 
860 	data_len = rx->skb->len - hdrlen - cs->hdr_len;
861 
862 	if (data_len < 0)
863 		return RX_DROP_UNUSABLE;
864 
865 	if (ieee80211_is_data_qos(hdr->frame_control))
866 		qos_tid = ieee80211_get_tid(hdr);
867 	else
868 		qos_tid = 0;
869 
870 	if (skb_linearize(rx->skb))
871 		return RX_DROP_UNUSABLE;
872 
873 	hdr = (struct ieee80211_hdr *)rx->skb->data;
874 
875 	rx_pn = key->u.gen.rx_pn[qos_tid];
876 	skb_pn = rx->skb->data + hdrlen + cs->pn_off;
877 
878 	if (ieee80211_crypto_cs_pn_compare(skb_pn, rx_pn, cs->pn_len) <= 0)
879 		return RX_DROP_UNUSABLE;
880 
881 	memcpy(rx_pn, skb_pn, cs->pn_len);
882 
883 	/* remove security header and MIC */
884 	if (pskb_trim(rx->skb, rx->skb->len - cs->mic_len))
885 		return RX_DROP_UNUSABLE;
886 
887 	memmove(rx->skb->data + cs->hdr_len, rx->skb->data, hdrlen);
888 	skb_pull(rx->skb, cs->hdr_len);
889 
890 	return RX_CONTINUE;
891 }
892 
893 static void bip_aad(struct sk_buff *skb, u8 *aad)
894 {
895 	__le16 mask_fc;
896 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
897 
898 	/* BIP AAD: FC(masked) || A1 || A2 || A3 */
899 
900 	/* FC type/subtype */
901 	/* Mask FC Retry, PwrMgt, MoreData flags to zero */
902 	mask_fc = hdr->frame_control;
903 	mask_fc &= ~cpu_to_le16(IEEE80211_FCTL_RETRY | IEEE80211_FCTL_PM |
904 				IEEE80211_FCTL_MOREDATA);
905 	put_unaligned(mask_fc, (__le16 *) &aad[0]);
906 	/* A1 || A2 || A3 */
907 	memcpy(aad + 2, &hdr->addr1, 3 * ETH_ALEN);
908 }
909 
910 
911 static inline void bip_ipn_set64(u8 *d, u64 pn)
912 {
913 	*d++ = pn;
914 	*d++ = pn >> 8;
915 	*d++ = pn >> 16;
916 	*d++ = pn >> 24;
917 	*d++ = pn >> 32;
918 	*d = pn >> 40;
919 }
920 
921 static inline void bip_ipn_swap(u8 *d, const u8 *s)
922 {
923 	*d++ = s[5];
924 	*d++ = s[4];
925 	*d++ = s[3];
926 	*d++ = s[2];
927 	*d++ = s[1];
928 	*d = s[0];
929 }
930 
931 
932 ieee80211_tx_result
933 ieee80211_crypto_aes_cmac_encrypt(struct ieee80211_tx_data *tx)
934 {
935 	struct sk_buff *skb;
936 	struct ieee80211_tx_info *info;
937 	struct ieee80211_key *key = tx->key;
938 	struct ieee80211_mmie *mmie;
939 	u8 aad[20];
940 	u64 pn64;
941 
942 	if (WARN_ON(skb_queue_len(&tx->skbs) != 1))
943 		return TX_DROP;
944 
945 	skb = skb_peek(&tx->skbs);
946 
947 	info = IEEE80211_SKB_CB(skb);
948 
949 	if (info->control.hw_key)
950 		return TX_CONTINUE;
951 
952 	if (WARN_ON(skb_tailroom(skb) < sizeof(*mmie)))
953 		return TX_DROP;
954 
955 	mmie = skb_put(skb, sizeof(*mmie));
956 	mmie->element_id = WLAN_EID_MMIE;
957 	mmie->length = sizeof(*mmie) - 2;
958 	mmie->key_id = cpu_to_le16(key->conf.keyidx);
959 
960 	/* PN = PN + 1 */
961 	pn64 = atomic64_inc_return(&key->conf.tx_pn);
962 
963 	bip_ipn_set64(mmie->sequence_number, pn64);
964 
965 	bip_aad(skb, aad);
966 
967 	/*
968 	 * MIC = AES-128-CMAC(IGTK, AAD || Management Frame Body || MMIE, 64)
969 	 */
970 	ieee80211_aes_cmac(key->u.aes_cmac.tfm, aad,
971 			   skb->data + 24, skb->len - 24, mmie->mic);
972 
973 	return TX_CONTINUE;
974 }
975 
976 ieee80211_tx_result
977 ieee80211_crypto_aes_cmac_256_encrypt(struct ieee80211_tx_data *tx)
978 {
979 	struct sk_buff *skb;
980 	struct ieee80211_tx_info *info;
981 	struct ieee80211_key *key = tx->key;
982 	struct ieee80211_mmie_16 *mmie;
983 	u8 aad[20];
984 	u64 pn64;
985 
986 	if (WARN_ON(skb_queue_len(&tx->skbs) != 1))
987 		return TX_DROP;
988 
989 	skb = skb_peek(&tx->skbs);
990 
991 	info = IEEE80211_SKB_CB(skb);
992 
993 	if (info->control.hw_key)
994 		return TX_CONTINUE;
995 
996 	if (WARN_ON(skb_tailroom(skb) < sizeof(*mmie)))
997 		return TX_DROP;
998 
999 	mmie = skb_put(skb, sizeof(*mmie));
1000 	mmie->element_id = WLAN_EID_MMIE;
1001 	mmie->length = sizeof(*mmie) - 2;
1002 	mmie->key_id = cpu_to_le16(key->conf.keyidx);
1003 
1004 	/* PN = PN + 1 */
1005 	pn64 = atomic64_inc_return(&key->conf.tx_pn);
1006 
1007 	bip_ipn_set64(mmie->sequence_number, pn64);
1008 
1009 	bip_aad(skb, aad);
1010 
1011 	/* MIC = AES-256-CMAC(IGTK, AAD || Management Frame Body || MMIE, 128)
1012 	 */
1013 	ieee80211_aes_cmac_256(key->u.aes_cmac.tfm, aad,
1014 			       skb->data + 24, skb->len - 24, mmie->mic);
1015 
1016 	return TX_CONTINUE;
1017 }
1018 
1019 ieee80211_rx_result
1020 ieee80211_crypto_aes_cmac_decrypt(struct ieee80211_rx_data *rx)
1021 {
1022 	struct sk_buff *skb = rx->skb;
1023 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
1024 	struct ieee80211_key *key = rx->key;
1025 	struct ieee80211_mmie *mmie;
1026 	u8 aad[20], mic[8], ipn[6];
1027 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
1028 
1029 	if (!ieee80211_is_mgmt(hdr->frame_control))
1030 		return RX_CONTINUE;
1031 
1032 	/* management frames are already linear */
1033 
1034 	if (skb->len < 24 + sizeof(*mmie))
1035 		return RX_DROP_UNUSABLE;
1036 
1037 	mmie = (struct ieee80211_mmie *)
1038 		(skb->data + skb->len - sizeof(*mmie));
1039 	if (mmie->element_id != WLAN_EID_MMIE ||
1040 	    mmie->length != sizeof(*mmie) - 2)
1041 		return RX_DROP_UNUSABLE; /* Invalid MMIE */
1042 
1043 	bip_ipn_swap(ipn, mmie->sequence_number);
1044 
1045 	if (memcmp(ipn, key->u.aes_cmac.rx_pn, 6) <= 0) {
1046 		key->u.aes_cmac.replays++;
1047 		return RX_DROP_UNUSABLE;
1048 	}
1049 
1050 	if (!(status->flag & RX_FLAG_DECRYPTED)) {
1051 		/* hardware didn't decrypt/verify MIC */
1052 		bip_aad(skb, aad);
1053 		ieee80211_aes_cmac(key->u.aes_cmac.tfm, aad,
1054 				   skb->data + 24, skb->len - 24, mic);
1055 		if (crypto_memneq(mic, mmie->mic, sizeof(mmie->mic))) {
1056 			key->u.aes_cmac.icverrors++;
1057 			return RX_DROP_UNUSABLE;
1058 		}
1059 	}
1060 
1061 	memcpy(key->u.aes_cmac.rx_pn, ipn, 6);
1062 
1063 	/* Remove MMIE */
1064 	skb_trim(skb, skb->len - sizeof(*mmie));
1065 
1066 	return RX_CONTINUE;
1067 }
1068 
1069 ieee80211_rx_result
1070 ieee80211_crypto_aes_cmac_256_decrypt(struct ieee80211_rx_data *rx)
1071 {
1072 	struct sk_buff *skb = rx->skb;
1073 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
1074 	struct ieee80211_key *key = rx->key;
1075 	struct ieee80211_mmie_16 *mmie;
1076 	u8 aad[20], mic[16], ipn[6];
1077 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
1078 
1079 	if (!ieee80211_is_mgmt(hdr->frame_control))
1080 		return RX_CONTINUE;
1081 
1082 	/* management frames are already linear */
1083 
1084 	if (skb->len < 24 + sizeof(*mmie))
1085 		return RX_DROP_UNUSABLE;
1086 
1087 	mmie = (struct ieee80211_mmie_16 *)
1088 		(skb->data + skb->len - sizeof(*mmie));
1089 	if (mmie->element_id != WLAN_EID_MMIE ||
1090 	    mmie->length != sizeof(*mmie) - 2)
1091 		return RX_DROP_UNUSABLE; /* Invalid MMIE */
1092 
1093 	bip_ipn_swap(ipn, mmie->sequence_number);
1094 
1095 	if (memcmp(ipn, key->u.aes_cmac.rx_pn, 6) <= 0) {
1096 		key->u.aes_cmac.replays++;
1097 		return RX_DROP_UNUSABLE;
1098 	}
1099 
1100 	if (!(status->flag & RX_FLAG_DECRYPTED)) {
1101 		/* hardware didn't decrypt/verify MIC */
1102 		bip_aad(skb, aad);
1103 		ieee80211_aes_cmac_256(key->u.aes_cmac.tfm, aad,
1104 				       skb->data + 24, skb->len - 24, mic);
1105 		if (crypto_memneq(mic, mmie->mic, sizeof(mmie->mic))) {
1106 			key->u.aes_cmac.icverrors++;
1107 			return RX_DROP_UNUSABLE;
1108 		}
1109 	}
1110 
1111 	memcpy(key->u.aes_cmac.rx_pn, ipn, 6);
1112 
1113 	/* Remove MMIE */
1114 	skb_trim(skb, skb->len - sizeof(*mmie));
1115 
1116 	return RX_CONTINUE;
1117 }
1118 
1119 ieee80211_tx_result
1120 ieee80211_crypto_aes_gmac_encrypt(struct ieee80211_tx_data *tx)
1121 {
1122 	struct sk_buff *skb;
1123 	struct ieee80211_tx_info *info;
1124 	struct ieee80211_key *key = tx->key;
1125 	struct ieee80211_mmie_16 *mmie;
1126 	struct ieee80211_hdr *hdr;
1127 	u8 aad[GMAC_AAD_LEN];
1128 	u64 pn64;
1129 	u8 nonce[GMAC_NONCE_LEN];
1130 
1131 	if (WARN_ON(skb_queue_len(&tx->skbs) != 1))
1132 		return TX_DROP;
1133 
1134 	skb = skb_peek(&tx->skbs);
1135 
1136 	info = IEEE80211_SKB_CB(skb);
1137 
1138 	if (info->control.hw_key)
1139 		return TX_CONTINUE;
1140 
1141 	if (WARN_ON(skb_tailroom(skb) < sizeof(*mmie)))
1142 		return TX_DROP;
1143 
1144 	mmie = skb_put(skb, sizeof(*mmie));
1145 	mmie->element_id = WLAN_EID_MMIE;
1146 	mmie->length = sizeof(*mmie) - 2;
1147 	mmie->key_id = cpu_to_le16(key->conf.keyidx);
1148 
1149 	/* PN = PN + 1 */
1150 	pn64 = atomic64_inc_return(&key->conf.tx_pn);
1151 
1152 	bip_ipn_set64(mmie->sequence_number, pn64);
1153 
1154 	bip_aad(skb, aad);
1155 
1156 	hdr = (struct ieee80211_hdr *)skb->data;
1157 	memcpy(nonce, hdr->addr2, ETH_ALEN);
1158 	bip_ipn_swap(nonce + ETH_ALEN, mmie->sequence_number);
1159 
1160 	/* MIC = AES-GMAC(IGTK, AAD || Management Frame Body || MMIE, 128) */
1161 	if (ieee80211_aes_gmac(key->u.aes_gmac.tfm, aad, nonce,
1162 			       skb->data + 24, skb->len - 24, mmie->mic) < 0)
1163 		return TX_DROP;
1164 
1165 	return TX_CONTINUE;
1166 }
1167 
1168 ieee80211_rx_result
1169 ieee80211_crypto_aes_gmac_decrypt(struct ieee80211_rx_data *rx)
1170 {
1171 	struct sk_buff *skb = rx->skb;
1172 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
1173 	struct ieee80211_key *key = rx->key;
1174 	struct ieee80211_mmie_16 *mmie;
1175 	u8 aad[GMAC_AAD_LEN], *mic, ipn[6], nonce[GMAC_NONCE_LEN];
1176 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
1177 
1178 	if (!ieee80211_is_mgmt(hdr->frame_control))
1179 		return RX_CONTINUE;
1180 
1181 	/* management frames are already linear */
1182 
1183 	if (skb->len < 24 + sizeof(*mmie))
1184 		return RX_DROP_UNUSABLE;
1185 
1186 	mmie = (struct ieee80211_mmie_16 *)
1187 		(skb->data + skb->len - sizeof(*mmie));
1188 	if (mmie->element_id != WLAN_EID_MMIE ||
1189 	    mmie->length != sizeof(*mmie) - 2)
1190 		return RX_DROP_UNUSABLE; /* Invalid MMIE */
1191 
1192 	bip_ipn_swap(ipn, mmie->sequence_number);
1193 
1194 	if (memcmp(ipn, key->u.aes_gmac.rx_pn, 6) <= 0) {
1195 		key->u.aes_gmac.replays++;
1196 		return RX_DROP_UNUSABLE;
1197 	}
1198 
1199 	if (!(status->flag & RX_FLAG_DECRYPTED)) {
1200 		/* hardware didn't decrypt/verify MIC */
1201 		bip_aad(skb, aad);
1202 
1203 		memcpy(nonce, hdr->addr2, ETH_ALEN);
1204 		memcpy(nonce + ETH_ALEN, ipn, 6);
1205 
1206 		mic = kmalloc(GMAC_MIC_LEN, GFP_ATOMIC);
1207 		if (!mic)
1208 			return RX_DROP_UNUSABLE;
1209 		if (ieee80211_aes_gmac(key->u.aes_gmac.tfm, aad, nonce,
1210 				       skb->data + 24, skb->len - 24,
1211 				       mic) < 0 ||
1212 		    crypto_memneq(mic, mmie->mic, sizeof(mmie->mic))) {
1213 			key->u.aes_gmac.icverrors++;
1214 			kfree(mic);
1215 			return RX_DROP_UNUSABLE;
1216 		}
1217 		kfree(mic);
1218 	}
1219 
1220 	memcpy(key->u.aes_gmac.rx_pn, ipn, 6);
1221 
1222 	/* Remove MMIE */
1223 	skb_trim(skb, skb->len - sizeof(*mmie));
1224 
1225 	return RX_CONTINUE;
1226 }
1227 
1228 ieee80211_tx_result
1229 ieee80211_crypto_hw_encrypt(struct ieee80211_tx_data *tx)
1230 {
1231 	struct sk_buff *skb;
1232 	struct ieee80211_tx_info *info = NULL;
1233 	ieee80211_tx_result res;
1234 
1235 	skb_queue_walk(&tx->skbs, skb) {
1236 		info  = IEEE80211_SKB_CB(skb);
1237 
1238 		/* handle hw-only algorithm */
1239 		if (!info->control.hw_key)
1240 			return TX_DROP;
1241 
1242 		if (tx->key->flags & KEY_FLAG_CIPHER_SCHEME) {
1243 			res = ieee80211_crypto_cs_encrypt(tx, skb);
1244 			if (res != TX_CONTINUE)
1245 				return res;
1246 		}
1247 	}
1248 
1249 	ieee80211_tx_set_protected(tx);
1250 
1251 	return TX_CONTINUE;
1252 }
1253 
1254 ieee80211_rx_result
1255 ieee80211_crypto_hw_decrypt(struct ieee80211_rx_data *rx)
1256 {
1257 	if (rx->sta && rx->sta->cipher_scheme)
1258 		return ieee80211_crypto_cs_decrypt(rx);
1259 
1260 	return RX_DROP_UNUSABLE;
1261 }
1262