xref: /openbmc/linux/net/mac80211/wpa.c (revision e868d61272caa648214046a096e5a6bfc068dc8c)
1 /*
2  * Copyright 2002-2004, Instant802 Networks, Inc.
3  *
4  * This program is free software; you can redistribute it and/or modify
5  * it under the terms of the GNU General Public License version 2 as
6  * published by the Free Software Foundation.
7  */
8 
9 #include <linux/netdevice.h>
10 #include <linux/types.h>
11 #include <linux/slab.h>
12 #include <linux/skbuff.h>
13 #include <linux/compiler.h>
14 #include <net/iw_handler.h>
15 
16 #include <net/mac80211.h>
17 #include "ieee80211_common.h"
18 #include "ieee80211_i.h"
19 #include "michael.h"
20 #include "tkip.h"
21 #include "aes_ccm.h"
22 #include "wpa.h"
23 
24 static int ieee80211_get_hdr_info(const struct sk_buff *skb, u8 **sa, u8 **da,
25 				  u8 *qos_tid, u8 **data, size_t *data_len)
26 {
27 	struct ieee80211_hdr *hdr;
28 	size_t hdrlen;
29 	u16 fc;
30 	int a4_included;
31 	u8 *pos;
32 
33 	hdr = (struct ieee80211_hdr *) skb->data;
34 	fc = le16_to_cpu(hdr->frame_control);
35 
36 	hdrlen = 24;
37 	if ((fc & (IEEE80211_FCTL_FROMDS | IEEE80211_FCTL_TODS)) ==
38 	    (IEEE80211_FCTL_FROMDS | IEEE80211_FCTL_TODS)) {
39 		hdrlen += ETH_ALEN;
40 		*sa = hdr->addr4;
41 		*da = hdr->addr3;
42 	} else if (fc & IEEE80211_FCTL_FROMDS) {
43 		*sa = hdr->addr3;
44 		*da = hdr->addr1;
45 	} else if (fc & IEEE80211_FCTL_TODS) {
46 		*sa = hdr->addr2;
47 		*da = hdr->addr3;
48 	} else {
49 		*sa = hdr->addr2;
50 		*da = hdr->addr1;
51 	}
52 
53 	if (fc & 0x80)
54 		hdrlen += 2;
55 
56 	*data = skb->data + hdrlen;
57 	*data_len = skb->len - hdrlen;
58 
59 	a4_included = (fc & (IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS)) ==
60 		(IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS);
61 	if ((fc & IEEE80211_FCTL_FTYPE) == IEEE80211_FTYPE_DATA &&
62 	    fc & IEEE80211_STYPE_QOS_DATA) {
63 		pos = (u8 *) &hdr->addr4;
64 		if (a4_included)
65 			pos += 6;
66 		*qos_tid = pos[0] & 0x0f;
67 		*qos_tid |= 0x80; /* qos_included flag */
68 	} else
69 		*qos_tid = 0;
70 
71 	return skb->len < hdrlen ? -1 : 0;
72 }
73 
74 
75 ieee80211_txrx_result
76 ieee80211_tx_h_michael_mic_add(struct ieee80211_txrx_data *tx)
77 {
78 	u8 *data, *sa, *da, *key, *mic, qos_tid;
79 	size_t data_len;
80 	u16 fc;
81 	struct sk_buff *skb = tx->skb;
82 	int authenticator;
83 	int wpa_test = 0;
84 
85 	fc = tx->fc;
86 
87 	if (!tx->key || tx->key->alg != ALG_TKIP || skb->len < 24 ||
88 	    !WLAN_FC_DATA_PRESENT(fc))
89 		return TXRX_CONTINUE;
90 
91 	if (ieee80211_get_hdr_info(skb, &sa, &da, &qos_tid, &data, &data_len))
92 		return TXRX_DROP;
93 
94 	if (!tx->key->force_sw_encrypt &&
95 	    !tx->fragmented &&
96 	    !(tx->local->hw.flags & IEEE80211_HW_TKIP_INCLUDE_MMIC) &&
97 	    !wpa_test) {
98 		/* hwaccel - with no need for preallocated room for Michael MIC
99 		 */
100 		return TXRX_CONTINUE;
101 	}
102 
103 	if (skb_tailroom(skb) < MICHAEL_MIC_LEN) {
104 		I802_DEBUG_INC(tx->local->tx_expand_skb_head);
105 		if (unlikely(pskb_expand_head(skb, TKIP_IV_LEN,
106 					      MICHAEL_MIC_LEN + TKIP_ICV_LEN,
107 					      GFP_ATOMIC))) {
108 			printk(KERN_DEBUG "%s: failed to allocate more memory "
109 			       "for Michael MIC\n", tx->dev->name);
110 			return TXRX_DROP;
111 		}
112 	}
113 
114 #if 0
115 	authenticator = fc & IEEE80211_FCTL_FROMDS; /* FIX */
116 #else
117 	authenticator = 1;
118 #endif
119 	key = &tx->key->key[authenticator ? ALG_TKIP_TEMP_AUTH_TX_MIC_KEY :
120 			    ALG_TKIP_TEMP_AUTH_RX_MIC_KEY];
121 	mic = skb_put(skb, MICHAEL_MIC_LEN);
122 	michael_mic(key, da, sa, qos_tid & 0x0f, data, data_len, mic);
123 
124 	return TXRX_CONTINUE;
125 }
126 
127 
128 ieee80211_txrx_result
129 ieee80211_rx_h_michael_mic_verify(struct ieee80211_txrx_data *rx)
130 {
131 	u8 *data, *sa, *da, *key = NULL, qos_tid;
132 	size_t data_len;
133 	u16 fc;
134 	u8 mic[MICHAEL_MIC_LEN];
135 	struct sk_buff *skb = rx->skb;
136 	int authenticator = 1, wpa_test = 0;
137 
138 	fc = rx->fc;
139 
140 	/* If device handles decryption totally, skip this check */
141 	if ((rx->local->hw.flags & IEEE80211_HW_DEVICE_HIDES_WEP) ||
142 	    (rx->local->hw.flags & IEEE80211_HW_DEVICE_STRIPS_MIC))
143 		return TXRX_CONTINUE;
144 
145 	if (!rx->key || rx->key->alg != ALG_TKIP ||
146 	    !(rx->fc & IEEE80211_FCTL_PROTECTED) || !WLAN_FC_DATA_PRESENT(fc))
147 		return TXRX_CONTINUE;
148 
149 	if ((rx->u.rx.status->flag & RX_FLAG_DECRYPTED) &&
150 	    !rx->key->force_sw_encrypt) {
151 		if (rx->local->hw.flags & IEEE80211_HW_WEP_INCLUDE_IV) {
152 			if (skb->len < MICHAEL_MIC_LEN)
153 				return TXRX_DROP;
154 		}
155 		/* Need to verify Michael MIC sometimes in software even when
156 		 * hwaccel is used. Atheros ar5212: fragmented frames and QoS
157 		 * frames. */
158 		if (!rx->fragmented && !wpa_test)
159 			goto remove_mic;
160 	}
161 
162 	if (ieee80211_get_hdr_info(skb, &sa, &da, &qos_tid, &data, &data_len)
163 	    || data_len < MICHAEL_MIC_LEN)
164 		return TXRX_DROP;
165 
166 	data_len -= MICHAEL_MIC_LEN;
167 
168 #if 0
169 	authenticator = fc & IEEE80211_FCTL_TODS; /* FIX */
170 #else
171 	authenticator = 1;
172 #endif
173 	key = &rx->key->key[authenticator ? ALG_TKIP_TEMP_AUTH_RX_MIC_KEY :
174 			    ALG_TKIP_TEMP_AUTH_TX_MIC_KEY];
175 	michael_mic(key, da, sa, qos_tid & 0x0f, data, data_len, mic);
176 	if (memcmp(mic, data + data_len, MICHAEL_MIC_LEN) != 0 || wpa_test) {
177 		if (!rx->u.rx.ra_match)
178 			return TXRX_DROP;
179 
180 		printk(KERN_DEBUG "%s: invalid Michael MIC in data frame from "
181 		       MAC_FMT "\n", rx->dev->name, MAC_ARG(sa));
182 
183 		do {
184 			struct ieee80211_hdr *hdr;
185 			union iwreq_data wrqu;
186 			char *buf = kmalloc(128, GFP_ATOMIC);
187 			if (!buf)
188 				break;
189 
190 			/* TODO: needed parameters: count, key type, TSC */
191 			hdr = (struct ieee80211_hdr *) skb->data;
192 			sprintf(buf, "MLME-MICHAELMICFAILURE.indication("
193 				"keyid=%d %scast addr=" MAC_FMT ")",
194 				rx->key->keyidx,
195 				hdr->addr1[0] & 0x01 ? "broad" : "uni",
196 				MAC_ARG(hdr->addr2));
197 			memset(&wrqu, 0, sizeof(wrqu));
198 			wrqu.data.length = strlen(buf);
199 			wireless_send_event(rx->dev, IWEVCUSTOM, &wrqu, buf);
200 			kfree(buf);
201 		} while (0);
202 
203 		if (!rx->local->apdev)
204 			return TXRX_DROP;
205 
206 		ieee80211_rx_mgmt(rx->local, rx->skb, rx->u.rx.status,
207 				  ieee80211_msg_michael_mic_failure);
208 
209 		return TXRX_QUEUED;
210 	}
211 
212  remove_mic:
213 	/* remove Michael MIC from payload */
214 	skb_trim(skb, skb->len - MICHAEL_MIC_LEN);
215 
216 	return TXRX_CONTINUE;
217 }
218 
219 
220 static int tkip_encrypt_skb(struct ieee80211_txrx_data *tx,
221 			    struct sk_buff *skb, int test)
222 {
223 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
224 	struct ieee80211_key *key = tx->key;
225 	int hdrlen, len, tailneed;
226 	u16 fc;
227 	u8 *pos;
228 
229 	fc = le16_to_cpu(hdr->frame_control);
230 	hdrlen = ieee80211_get_hdrlen(fc);
231 	len = skb->len - hdrlen;
232 
233 	tailneed = !tx->key->force_sw_encrypt ? 0 : TKIP_ICV_LEN;
234 	if ((skb_headroom(skb) < TKIP_IV_LEN ||
235 	     skb_tailroom(skb) < tailneed)) {
236 		I802_DEBUG_INC(tx->local->tx_expand_skb_head);
237 		if (unlikely(pskb_expand_head(skb, TKIP_IV_LEN, tailneed,
238 					      GFP_ATOMIC)))
239 			return -1;
240 	}
241 
242 	pos = skb_push(skb, TKIP_IV_LEN);
243 	memmove(pos, pos + TKIP_IV_LEN, hdrlen);
244 	pos += hdrlen;
245 
246 	/* Increase IV for the frame */
247 	key->u.tkip.iv16++;
248 	if (key->u.tkip.iv16 == 0)
249 		key->u.tkip.iv32++;
250 
251 	if (!tx->key->force_sw_encrypt) {
252 		u32 flags = tx->local->hw.flags;
253 		hdr = (struct ieee80211_hdr *)skb->data;
254 
255 		/* hwaccel - with preallocated room for IV */
256 		ieee80211_tkip_add_iv(pos, key,
257 				      (u8) (key->u.tkip.iv16 >> 8),
258 				      (u8) (((key->u.tkip.iv16 >> 8) | 0x20) &
259 					    0x7f),
260 				      (u8) key->u.tkip.iv16);
261 
262 		if (flags & IEEE80211_HW_TKIP_REQ_PHASE2_KEY)
263 			ieee80211_tkip_gen_rc4key(key, hdr->addr2,
264 						  tx->u.tx.control->tkip_key);
265 		else if (flags & IEEE80211_HW_TKIP_REQ_PHASE1_KEY) {
266 			if (key->u.tkip.iv16 == 0 ||
267 			    !key->u.tkip.tx_initialized) {
268 				ieee80211_tkip_gen_phase1key(key, hdr->addr2,
269 					    (u16 *)tx->u.tx.control->tkip_key);
270 				key->u.tkip.tx_initialized = 1;
271 				tx->u.tx.control->flags |=
272 					    IEEE80211_TXCTL_TKIP_NEW_PHASE1_KEY;
273 			} else
274 				tx->u.tx.control->flags &=
275 					    ~IEEE80211_TXCTL_TKIP_NEW_PHASE1_KEY;
276 		}
277 
278 		tx->u.tx.control->key_idx = tx->key->hw_key_idx;
279 		return 0;
280 	}
281 
282 	/* Add room for ICV */
283 	skb_put(skb, TKIP_ICV_LEN);
284 
285 	hdr = (struct ieee80211_hdr *) skb->data;
286 	ieee80211_tkip_encrypt_data(tx->local->wep_tx_tfm,
287 				    key, pos, len, hdr->addr2);
288 	return 0;
289 }
290 
291 
292 ieee80211_txrx_result
293 ieee80211_tx_h_tkip_encrypt(struct ieee80211_txrx_data *tx)
294 {
295 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) tx->skb->data;
296 	u16 fc;
297 	struct ieee80211_key *key = tx->key;
298 	struct sk_buff *skb = tx->skb;
299 	int wpa_test = 0, test = 0;
300 
301 	fc = le16_to_cpu(hdr->frame_control);
302 
303 	if (!key || key->alg != ALG_TKIP || !WLAN_FC_DATA_PRESENT(fc))
304 		return TXRX_CONTINUE;
305 
306 	tx->u.tx.control->icv_len = TKIP_ICV_LEN;
307 	tx->u.tx.control->iv_len = TKIP_IV_LEN;
308 	ieee80211_tx_set_iswep(tx);
309 
310 	if (!tx->key->force_sw_encrypt &&
311 	    !(tx->local->hw.flags & IEEE80211_HW_WEP_INCLUDE_IV) &&
312 	    !wpa_test) {
313 		/* hwaccel - with no need for preallocated room for IV/ICV */
314 		tx->u.tx.control->key_idx = tx->key->hw_key_idx;
315 		return TXRX_CONTINUE;
316 	}
317 
318 	if (tkip_encrypt_skb(tx, skb, test) < 0)
319 		return TXRX_DROP;
320 
321 	if (tx->u.tx.extra_frag) {
322 		int i;
323 		for (i = 0; i < tx->u.tx.num_extra_frag; i++) {
324 			if (tkip_encrypt_skb(tx, tx->u.tx.extra_frag[i], test)
325 			    < 0)
326 				return TXRX_DROP;
327 		}
328 	}
329 
330 	return TXRX_CONTINUE;
331 }
332 
333 
334 ieee80211_txrx_result
335 ieee80211_rx_h_tkip_decrypt(struct ieee80211_txrx_data *rx)
336 {
337 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) rx->skb->data;
338 	u16 fc;
339 	int hdrlen, res, hwaccel = 0, wpa_test = 0;
340 	struct ieee80211_key *key = rx->key;
341 	struct sk_buff *skb = rx->skb;
342 
343 	fc = le16_to_cpu(hdr->frame_control);
344 	hdrlen = ieee80211_get_hdrlen(fc);
345 
346 	if (!rx->key || rx->key->alg != ALG_TKIP ||
347 	    !(rx->fc & IEEE80211_FCTL_PROTECTED) ||
348 	    (rx->fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_DATA)
349 		return TXRX_CONTINUE;
350 
351 	if (!rx->sta || skb->len - hdrlen < 12)
352 		return TXRX_DROP;
353 
354 	if ((rx->u.rx.status->flag & RX_FLAG_DECRYPTED) &&
355 	    !rx->key->force_sw_encrypt) {
356 		if (!(rx->local->hw.flags & IEEE80211_HW_WEP_INCLUDE_IV)) {
357 			/* Hardware takes care of all processing, including
358 			 * replay protection, so no need to continue here. */
359 			return TXRX_CONTINUE;
360 		}
361 
362 		/* let TKIP code verify IV, but skip decryption */
363 		hwaccel = 1;
364 	}
365 
366 	res = ieee80211_tkip_decrypt_data(rx->local->wep_rx_tfm,
367 					  key, skb->data + hdrlen,
368 					  skb->len - hdrlen, rx->sta->addr,
369 					  hwaccel, rx->u.rx.queue);
370 	if (res != TKIP_DECRYPT_OK || wpa_test) {
371 		printk(KERN_DEBUG "%s: TKIP decrypt failed for RX frame from "
372 		       MAC_FMT " (res=%d)\n",
373 		       rx->dev->name, MAC_ARG(rx->sta->addr), res);
374 		return TXRX_DROP;
375 	}
376 
377 	/* Trim ICV */
378 	skb_trim(skb, skb->len - TKIP_ICV_LEN);
379 
380 	/* Remove IV */
381 	memmove(skb->data + TKIP_IV_LEN, skb->data, hdrlen);
382 	skb_pull(skb, TKIP_IV_LEN);
383 
384 	return TXRX_CONTINUE;
385 }
386 
387 
388 static void ccmp_special_blocks(struct sk_buff *skb, u8 *pn, u8 *b_0, u8 *aad,
389 				int encrypted)
390 {
391 	u16 fc;
392 	int a4_included, qos_included;
393 	u8 qos_tid, *fc_pos, *data, *sa, *da;
394 	int len_a;
395 	size_t data_len;
396 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
397 
398 	fc_pos = (u8 *) &hdr->frame_control;
399 	fc = fc_pos[0] ^ (fc_pos[1] << 8);
400 	a4_included = (fc & (IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS)) ==
401 		(IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS);
402 
403 	ieee80211_get_hdr_info(skb, &sa, &da, &qos_tid, &data, &data_len);
404 	data_len -= CCMP_HDR_LEN + (encrypted ? CCMP_MIC_LEN : 0);
405 	if (qos_tid & 0x80) {
406 		qos_included = 1;
407 		qos_tid &= 0x0f;
408 	} else
409 		qos_included = 0;
410 	/* First block, b_0 */
411 
412 	b_0[0] = 0x59; /* flags: Adata: 1, M: 011, L: 001 */
413 	/* Nonce: QoS Priority | A2 | PN */
414 	b_0[1] = qos_tid;
415 	memcpy(&b_0[2], hdr->addr2, 6);
416 	memcpy(&b_0[8], pn, CCMP_PN_LEN);
417 	/* l(m) */
418 	b_0[14] = (data_len >> 8) & 0xff;
419 	b_0[15] = data_len & 0xff;
420 
421 
422 	/* AAD (extra authenticate-only data) / masked 802.11 header
423 	 * FC | A1 | A2 | A3 | SC | [A4] | [QC] */
424 
425 	len_a = a4_included ? 28 : 22;
426 	if (qos_included)
427 		len_a += 2;
428 
429 	aad[0] = 0; /* (len_a >> 8) & 0xff; */
430 	aad[1] = len_a & 0xff;
431 	/* Mask FC: zero subtype b4 b5 b6 */
432 	aad[2] = fc_pos[0] & ~(BIT(4) | BIT(5) | BIT(6));
433 	/* Retry, PwrMgt, MoreData; set Protected */
434 	aad[3] = (fc_pos[1] & ~(BIT(3) | BIT(4) | BIT(5))) | BIT(6);
435 	memcpy(&aad[4], &hdr->addr1, 18);
436 
437 	/* Mask Seq#, leave Frag# */
438 	aad[22] = *((u8 *) &hdr->seq_ctrl) & 0x0f;
439 	aad[23] = 0;
440 	if (a4_included) {
441 		memcpy(&aad[24], hdr->addr4, 6);
442 		aad[30] = 0;
443 		aad[31] = 0;
444 	} else
445 		memset(&aad[24], 0, 8);
446 	if (qos_included) {
447 		u8 *dpos = &aad[a4_included ? 30 : 24];
448 
449 		/* Mask QoS Control field */
450 		dpos[0] = qos_tid;
451 		dpos[1] = 0;
452 	}
453 }
454 
455 
456 static inline void ccmp_pn2hdr(u8 *hdr, u8 *pn, int key_id)
457 {
458 	hdr[0] = pn[5];
459 	hdr[1] = pn[4];
460 	hdr[2] = 0;
461 	hdr[3] = 0x20 | (key_id << 6);
462 	hdr[4] = pn[3];
463 	hdr[5] = pn[2];
464 	hdr[6] = pn[1];
465 	hdr[7] = pn[0];
466 }
467 
468 
469 static inline int ccmp_hdr2pn(u8 *pn, u8 *hdr)
470 {
471 	pn[0] = hdr[7];
472 	pn[1] = hdr[6];
473 	pn[2] = hdr[5];
474 	pn[3] = hdr[4];
475 	pn[4] = hdr[1];
476 	pn[5] = hdr[0];
477 	return (hdr[3] >> 6) & 0x03;
478 }
479 
480 
481 static int ccmp_encrypt_skb(struct ieee80211_txrx_data *tx,
482 			    struct sk_buff *skb, int test)
483 {
484 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
485 	struct ieee80211_key *key = tx->key;
486 	int hdrlen, len, tailneed;
487 	u16 fc;
488 	u8 *pos, *pn, *b_0, *aad, *scratch;
489 	int i;
490 
491 	scratch = key->u.ccmp.tx_crypto_buf;
492 	b_0 = scratch + 3 * AES_BLOCK_LEN;
493 	aad = scratch + 4 * AES_BLOCK_LEN;
494 
495 	fc = le16_to_cpu(hdr->frame_control);
496 	hdrlen = ieee80211_get_hdrlen(fc);
497 	len = skb->len - hdrlen;
498 
499 	tailneed = !key->force_sw_encrypt ? 0 : CCMP_MIC_LEN;
500 
501 	if ((skb_headroom(skb) < CCMP_HDR_LEN ||
502 	     skb_tailroom(skb) < tailneed)) {
503 		I802_DEBUG_INC(tx->local->tx_expand_skb_head);
504 		if (unlikely(pskb_expand_head(skb, CCMP_HDR_LEN, tailneed,
505 					      GFP_ATOMIC)))
506 			return -1;
507 	}
508 
509 	pos = skb_push(skb, CCMP_HDR_LEN);
510 	memmove(pos, pos + CCMP_HDR_LEN, hdrlen);
511 	hdr = (struct ieee80211_hdr *) pos;
512 	pos += hdrlen;
513 
514 	/* PN = PN + 1 */
515 	pn = key->u.ccmp.tx_pn;
516 
517 	for (i = CCMP_PN_LEN - 1; i >= 0; i--) {
518 		pn[i]++;
519 		if (pn[i])
520 			break;
521 	}
522 
523 	ccmp_pn2hdr(pos, pn, key->keyidx);
524 
525 	if (!key->force_sw_encrypt) {
526 		/* hwaccel - with preallocated room for CCMP header */
527 		tx->u.tx.control->key_idx = key->hw_key_idx;
528 		return 0;
529 	}
530 
531 	pos += CCMP_HDR_LEN;
532 	ccmp_special_blocks(skb, pn, b_0, aad, 0);
533 	ieee80211_aes_ccm_encrypt(key->u.ccmp.tfm, scratch, b_0, aad, pos, len,
534 				  pos, skb_put(skb, CCMP_MIC_LEN));
535 
536 	return 0;
537 }
538 
539 
540 ieee80211_txrx_result
541 ieee80211_tx_h_ccmp_encrypt(struct ieee80211_txrx_data *tx)
542 {
543 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) tx->skb->data;
544 	struct ieee80211_key *key = tx->key;
545 	u16 fc;
546 	struct sk_buff *skb = tx->skb;
547 	int test = 0;
548 
549 	fc = le16_to_cpu(hdr->frame_control);
550 
551 	if (!key || key->alg != ALG_CCMP || !WLAN_FC_DATA_PRESENT(fc))
552 		return TXRX_CONTINUE;
553 
554 	tx->u.tx.control->icv_len = CCMP_MIC_LEN;
555 	tx->u.tx.control->iv_len = CCMP_HDR_LEN;
556 	ieee80211_tx_set_iswep(tx);
557 
558 	if (!tx->key->force_sw_encrypt &&
559 	    !(tx->local->hw.flags & IEEE80211_HW_WEP_INCLUDE_IV)) {
560 		/* hwaccel - with no need for preallocated room for CCMP "
561 		 * header or MIC fields */
562 		tx->u.tx.control->key_idx = tx->key->hw_key_idx;
563 		return TXRX_CONTINUE;
564 	}
565 
566 	if (ccmp_encrypt_skb(tx, skb, test) < 0)
567 		return TXRX_DROP;
568 
569 	if (tx->u.tx.extra_frag) {
570 		int i;
571 
572 		for (i = 0; i < tx->u.tx.num_extra_frag; i++) {
573 			if (ccmp_encrypt_skb(tx, tx->u.tx.extra_frag[i], test)
574 			    < 0)
575 				return TXRX_DROP;
576 		}
577 	}
578 
579 	return TXRX_CONTINUE;
580 }
581 
582 
583 ieee80211_txrx_result
584 ieee80211_rx_h_ccmp_decrypt(struct ieee80211_txrx_data *rx)
585 {
586 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) rx->skb->data;
587 	u16 fc;
588 	int hdrlen;
589 	struct ieee80211_key *key = rx->key;
590 	struct sk_buff *skb = rx->skb;
591 	u8 pn[CCMP_PN_LEN];
592 	int data_len;
593 
594 	fc = le16_to_cpu(hdr->frame_control);
595 	hdrlen = ieee80211_get_hdrlen(fc);
596 
597 	if (!key || key->alg != ALG_CCMP ||
598 	    !(rx->fc & IEEE80211_FCTL_PROTECTED) ||
599 	    (rx->fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_DATA)
600 		return TXRX_CONTINUE;
601 
602 	data_len = skb->len - hdrlen - CCMP_HDR_LEN - CCMP_MIC_LEN;
603 	if (!rx->sta || data_len < 0)
604 		return TXRX_DROP;
605 
606 	if ((rx->u.rx.status->flag & RX_FLAG_DECRYPTED) &&
607 	    !key->force_sw_encrypt &&
608 	    !(rx->local->hw.flags & IEEE80211_HW_WEP_INCLUDE_IV))
609 		return TXRX_CONTINUE;
610 
611 	(void) ccmp_hdr2pn(pn, skb->data + hdrlen);
612 
613 	if (memcmp(pn, key->u.ccmp.rx_pn[rx->u.rx.queue], CCMP_PN_LEN) <= 0) {
614 #ifdef CONFIG_MAC80211_DEBUG
615 		u8 *ppn = key->u.ccmp.rx_pn[rx->u.rx.queue];
616 		printk(KERN_DEBUG "%s: CCMP replay detected for RX frame from "
617 		       MAC_FMT " (RX PN %02x%02x%02x%02x%02x%02x <= prev. PN "
618 		       "%02x%02x%02x%02x%02x%02x)\n", rx->dev->name,
619 		       MAC_ARG(rx->sta->addr),
620 		       pn[0], pn[1], pn[2], pn[3], pn[4], pn[5],
621 		       ppn[0], ppn[1], ppn[2], ppn[3], ppn[4], ppn[5]);
622 #endif /* CONFIG_MAC80211_DEBUG */
623 		key->u.ccmp.replays++;
624 		return TXRX_DROP;
625 	}
626 
627 	if ((rx->u.rx.status->flag & RX_FLAG_DECRYPTED) &&
628 	    !key->force_sw_encrypt) {
629 		/* hwaccel has already decrypted frame and verified MIC */
630 	} else {
631 		u8 *scratch, *b_0, *aad;
632 
633 		scratch = key->u.ccmp.rx_crypto_buf;
634 		b_0 = scratch + 3 * AES_BLOCK_LEN;
635 		aad = scratch + 4 * AES_BLOCK_LEN;
636 
637 		ccmp_special_blocks(skb, pn, b_0, aad, 1);
638 
639 		if (ieee80211_aes_ccm_decrypt(
640 			    key->u.ccmp.tfm, scratch, b_0, aad,
641 			    skb->data + hdrlen + CCMP_HDR_LEN, data_len,
642 			    skb->data + skb->len - CCMP_MIC_LEN,
643 			    skb->data + hdrlen + CCMP_HDR_LEN)) {
644 			printk(KERN_DEBUG "%s: CCMP decrypt failed for RX "
645 			       "frame from " MAC_FMT "\n", rx->dev->name,
646 			       MAC_ARG(rx->sta->addr));
647 			return TXRX_DROP;
648 		}
649 	}
650 
651 	memcpy(key->u.ccmp.rx_pn[rx->u.rx.queue], pn, CCMP_PN_LEN);
652 
653 	/* Remove CCMP header and MIC */
654 	skb_trim(skb, skb->len - CCMP_MIC_LEN);
655 	memmove(skb->data + CCMP_HDR_LEN, skb->data, hdrlen);
656 	skb_pull(skb, CCMP_HDR_LEN);
657 
658 	return TXRX_CONTINUE;
659 }
660 
661