tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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/mac80211.h>
15
16#include "ieee80211_i.h"
17#include "michael.h"
18#include "tkip.h"
19#include "aes_ccm.h"
20#include "wpa.h"
21
22static int ieee80211_get_hdr_info(const struct sk_buff *skb, u8 **sa, u8 **da,
23 u8 *qos_tid, u8 **data, size_t *data_len)
24{
25 struct ieee80211_hdr *hdr;
26 size_t hdrlen;
27 u16 fc;
28 int a4_included;
29 u8 *pos;
30
31 hdr = (struct ieee80211_hdr *) skb->data;
32 fc = le16_to_cpu(hdr->frame_control);
33
34 hdrlen = 24;
35 if ((fc & (IEEE80211_FCTL_FROMDS | IEEE80211_FCTL_TODS)) ==
36 (IEEE80211_FCTL_FROMDS | IEEE80211_FCTL_TODS)) {
37 hdrlen += ETH_ALEN;
38 *sa = hdr->addr4;
39 *da = hdr->addr3;
40 } else if (fc & IEEE80211_FCTL_FROMDS) {
41 *sa = hdr->addr3;
42 *da = hdr->addr1;
43 } else if (fc & IEEE80211_FCTL_TODS) {
44 *sa = hdr->addr2;
45 *da = hdr->addr3;
46 } else {
47 *sa = hdr->addr2;
48 *da = hdr->addr1;
49 }
50
51 if (fc & 0x80)
52 hdrlen += 2;
53
54 *data = skb->data + hdrlen;
55 *data_len = skb->len - hdrlen;
56
57 a4_included = (fc & (IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS)) ==
58 (IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS);
59 if ((fc & IEEE80211_FCTL_FTYPE) == IEEE80211_FTYPE_DATA &&
60 fc & IEEE80211_STYPE_QOS_DATA) {
61 pos = (u8 *) &hdr->addr4;
62 if (a4_included)
63 pos += 6;
64 *qos_tid = pos[0] & 0x0f;
65 *qos_tid |= 0x80; /* qos_included flag */
66 } else
67 *qos_tid = 0;
68
69 return skb->len < hdrlen ? -1 : 0;
70}
71
72
73ieee80211_txrx_result
74ieee80211_tx_h_michael_mic_add(struct ieee80211_txrx_data *tx)
75{
76 u8 *data, *sa, *da, *key, *mic, qos_tid;
77 size_t data_len;
78 u16 fc;
79 struct sk_buff *skb = tx->skb;
80 int authenticator;
81 int wpa_test = 0;
82
83 fc = tx->fc;
84
85 if (!tx->key || tx->key->conf.alg != ALG_TKIP || skb->len < 24 ||
86 !WLAN_FC_DATA_PRESENT(fc))
87 return TXRX_CONTINUE;
88
89 if (ieee80211_get_hdr_info(skb, &sa, &da, &qos_tid, &data, &data_len))
90 return TXRX_DROP;
91
92 if ((tx->key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE) &&
93 !(tx->flags & IEEE80211_TXRXD_FRAGMENTED) &&
94 !(tx->key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_MMIC) &&
95 !wpa_test) {
96 /* hwaccel - with no need for preallocated room for Michael MIC
97 */
98 return TXRX_CONTINUE;
99 }
100
101 if (skb_tailroom(skb) < MICHAEL_MIC_LEN) {
102 I802_DEBUG_INC(tx->local->tx_expand_skb_head);
103 if (unlikely(pskb_expand_head(skb, TKIP_IV_LEN,
104 MICHAEL_MIC_LEN + TKIP_ICV_LEN,
105 GFP_ATOMIC))) {
106 printk(KERN_DEBUG "%s: failed to allocate more memory "
107 "for Michael MIC\n", tx->dev->name);
108 return TXRX_DROP;
109 }
110 }
111
112#if 0
113 authenticator = fc & IEEE80211_FCTL_FROMDS; /* FIX */
114#else
115 authenticator = 1;
116#endif
117 key = &tx->key->conf.key[authenticator ? ALG_TKIP_TEMP_AUTH_TX_MIC_KEY :
118 ALG_TKIP_TEMP_AUTH_RX_MIC_KEY];
119 mic = skb_put(skb, MICHAEL_MIC_LEN);
120 michael_mic(key, da, sa, qos_tid & 0x0f, data, data_len, mic);
121
122 return TXRX_CONTINUE;
123}
124
125
126ieee80211_txrx_result
127ieee80211_rx_h_michael_mic_verify(struct ieee80211_txrx_data *rx)
128{
129 u8 *data, *sa, *da, *key = NULL, qos_tid;
130 size_t data_len;
131 u16 fc;
132 u8 mic[MICHAEL_MIC_LEN];
133 struct sk_buff *skb = rx->skb;
134 int authenticator = 1, wpa_test = 0;
135 DECLARE_MAC_BUF(mac);
136
137 fc = rx->fc;
138
139 /*
140 * No way to verify the MIC if the hardware stripped it
141 */
142 if (rx->u.rx.status->flag & RX_FLAG_MMIC_STRIPPED)
143 return TXRX_CONTINUE;
144
145 if (!rx->key || rx->key->conf.alg != ALG_TKIP ||
146 !(rx->fc & IEEE80211_FCTL_PROTECTED) || !WLAN_FC_DATA_PRESENT(fc))
147 return TXRX_CONTINUE;
148
149 if (ieee80211_get_hdr_info(skb, &sa, &da, &qos_tid, &data, &data_len)
150 || data_len < MICHAEL_MIC_LEN)
151 return TXRX_DROP;
152
153 data_len -= MICHAEL_MIC_LEN;
154
155#if 0
156 authenticator = fc & IEEE80211_FCTL_TODS; /* FIX */
157#else
158 authenticator = 1;
159#endif
160 key = &rx->key->conf.key[authenticator ? ALG_TKIP_TEMP_AUTH_RX_MIC_KEY :
161 ALG_TKIP_TEMP_AUTH_TX_MIC_KEY];
162 michael_mic(key, da, sa, qos_tid & 0x0f, data, data_len, mic);
163 if (memcmp(mic, data + data_len, MICHAEL_MIC_LEN) != 0 || wpa_test) {
164 if (!(rx->flags & IEEE80211_TXRXD_RXRA_MATCH))
165 return TXRX_DROP;
166
167 printk(KERN_DEBUG "%s: invalid Michael MIC in data frame from "
168 "%s\n", rx->dev->name, print_mac(mac, sa));
169
170 mac80211_ev_michael_mic_failure(rx->dev, rx->key->conf.keyidx,
171 (void *) skb->data);
172 return TXRX_DROP;
173 }
174
175 /* remove Michael MIC from payload */
176 skb_trim(skb, skb->len - MICHAEL_MIC_LEN);
177
178 /* update IV in key information to be able to detect replays */
179 rx->key->u.tkip.iv32_rx[rx->u.rx.queue] = rx->u.rx.tkip_iv32;
180 rx->key->u.tkip.iv16_rx[rx->u.rx.queue] = rx->u.rx.tkip_iv16;
181
182 return TXRX_CONTINUE;
183}
184
185
186static int tkip_encrypt_skb(struct ieee80211_txrx_data *tx,
187 struct sk_buff *skb, int test)
188{
189 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
190 struct ieee80211_key *key = tx->key;
191 int hdrlen, len, tailneed;
192 u16 fc;
193 u8 *pos;
194
195 fc = le16_to_cpu(hdr->frame_control);
196 hdrlen = ieee80211_get_hdrlen(fc);
197 len = skb->len - hdrlen;
198
199 if (tx->key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE)
200 tailneed = 0;
201 else
202 tailneed = TKIP_ICV_LEN;
203
204 if ((skb_headroom(skb) < TKIP_IV_LEN ||
205 skb_tailroom(skb) < tailneed)) {
206 I802_DEBUG_INC(tx->local->tx_expand_skb_head);
207 if (unlikely(pskb_expand_head(skb, TKIP_IV_LEN, tailneed,
208 GFP_ATOMIC)))
209 return -1;
210 }
211
212 pos = skb_push(skb, TKIP_IV_LEN);
213 memmove(pos, pos + TKIP_IV_LEN, hdrlen);
214 pos += hdrlen;
215
216 /* Increase IV for the frame */
217 key->u.tkip.iv16++;
218 if (key->u.tkip.iv16 == 0)
219 key->u.tkip.iv32++;
220
221 if (tx->key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE) {
222 hdr = (struct ieee80211_hdr *)skb->data;
223
224 /* hwaccel - with preallocated room for IV */
225 ieee80211_tkip_add_iv(pos, key,
226 (u8) (key->u.tkip.iv16 >> 8),
227 (u8) (((key->u.tkip.iv16 >> 8) | 0x20) &
228 0x7f),
229 (u8) key->u.tkip.iv16);
230
231 tx->u.tx.control->key_idx = tx->key->conf.hw_key_idx;
232 return 0;
233 }
234
235 /* Add room for ICV */
236 skb_put(skb, TKIP_ICV_LEN);
237
238 hdr = (struct ieee80211_hdr *) skb->data;
239 ieee80211_tkip_encrypt_data(tx->local->wep_tx_tfm,
240 key, pos, len, hdr->addr2);
241 return 0;
242}
243
244
245ieee80211_txrx_result
246ieee80211_crypto_tkip_encrypt(struct ieee80211_txrx_data *tx)
247{
248 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) tx->skb->data;
249 u16 fc;
250 struct sk_buff *skb = tx->skb;
251 int wpa_test = 0, test = 0;
252
253 fc = le16_to_cpu(hdr->frame_control);
254
255 if (!WLAN_FC_DATA_PRESENT(fc))
256 return TXRX_CONTINUE;
257
258 tx->u.tx.control->icv_len = TKIP_ICV_LEN;
259 tx->u.tx.control->iv_len = TKIP_IV_LEN;
260 ieee80211_tx_set_iswep(tx);
261
262 if ((tx->key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE) &&
263 !(tx->key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_IV) &&
264 !wpa_test) {
265 /* hwaccel - with no need for preallocated room for IV/ICV */
266 tx->u.tx.control->key_idx = tx->key->conf.hw_key_idx;
267 return TXRX_CONTINUE;
268 }
269
270 if (tkip_encrypt_skb(tx, skb, test) < 0)
271 return TXRX_DROP;
272
273 if (tx->u.tx.extra_frag) {
274 int i;
275 for (i = 0; i < tx->u.tx.num_extra_frag; i++) {
276 if (tkip_encrypt_skb(tx, tx->u.tx.extra_frag[i], test)
277 < 0)
278 return TXRX_DROP;
279 }
280 }
281
282 return TXRX_CONTINUE;
283}
284
285
286ieee80211_txrx_result
287ieee80211_crypto_tkip_decrypt(struct ieee80211_txrx_data *rx)
288{
289 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) rx->skb->data;
290 u16 fc;
291 int hdrlen, res, hwaccel = 0, wpa_test = 0;
292 struct ieee80211_key *key = rx->key;
293 struct sk_buff *skb = rx->skb;
294 DECLARE_MAC_BUF(mac);
295
296 fc = le16_to_cpu(hdr->frame_control);
297 hdrlen = ieee80211_get_hdrlen(fc);
298
299 if ((rx->fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_DATA)
300 return TXRX_CONTINUE;
301
302 if (!rx->sta || skb->len - hdrlen < 12)
303 return TXRX_DROP;
304
305 if (rx->u.rx.status->flag & RX_FLAG_DECRYPTED) {
306 if (rx->u.rx.status->flag & RX_FLAG_IV_STRIPPED) {
307 /*
308 * Hardware took care of all processing, including
309 * replay protection, and stripped the ICV/IV so
310 * we cannot do any checks here.
311 */
312 return TXRX_CONTINUE;
313 }
314
315 /* let TKIP code verify IV, but skip decryption */
316 hwaccel = 1;
317 }
318
319 res = ieee80211_tkip_decrypt_data(rx->local->wep_rx_tfm,
320 key, skb->data + hdrlen,
321 skb->len - hdrlen, rx->sta->addr,
322 hwaccel, rx->u.rx.queue,
323 &rx->u.rx.tkip_iv32,
324 &rx->u.rx.tkip_iv16);
325 if (res != TKIP_DECRYPT_OK || wpa_test) {
326#ifdef CONFIG_MAC80211_DEBUG
327 if (net_ratelimit())
328 printk(KERN_DEBUG "%s: TKIP decrypt failed for RX "
329 "frame from %s (res=%d)\n", rx->dev->name,
330 print_mac(mac, rx->sta->addr), res);
331#endif /* CONFIG_MAC80211_DEBUG */
332 return TXRX_DROP;
333 }
334
335 /* Trim ICV */
336 skb_trim(skb, skb->len - TKIP_ICV_LEN);
337
338 /* Remove IV */
339 memmove(skb->data + TKIP_IV_LEN, skb->data, hdrlen);
340 skb_pull(skb, TKIP_IV_LEN);
341
342 return TXRX_CONTINUE;
343}
344
345
346static void ccmp_special_blocks(struct sk_buff *skb, u8 *pn, u8 *b_0, u8 *aad,
347 int encrypted)
348{
349 u16 fc;
350 int a4_included, qos_included;
351 u8 qos_tid, *fc_pos, *data, *sa, *da;
352 int len_a;
353 size_t data_len;
354 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
355
356 fc_pos = (u8 *) &hdr->frame_control;
357 fc = fc_pos[0] ^ (fc_pos[1] << 8);
358 a4_included = (fc & (IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS)) ==
359 (IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS);
360
361 ieee80211_get_hdr_info(skb, &sa, &da, &qos_tid, &data, &data_len);
362 data_len -= CCMP_HDR_LEN + (encrypted ? CCMP_MIC_LEN : 0);
363 if (qos_tid & 0x80) {
364 qos_included = 1;
365 qos_tid &= 0x0f;
366 } else
367 qos_included = 0;
368 /* First block, b_0 */
369
370 b_0[0] = 0x59; /* flags: Adata: 1, M: 011, L: 001 */
371 /* Nonce: QoS Priority | A2 | PN */
372 b_0[1] = qos_tid;
373 memcpy(&b_0[2], hdr->addr2, 6);
374 memcpy(&b_0[8], pn, CCMP_PN_LEN);
375 /* l(m) */
376 b_0[14] = (data_len >> 8) & 0xff;
377 b_0[15] = data_len & 0xff;
378
379
380 /* AAD (extra authenticate-only data) / masked 802.11 header
381 * FC | A1 | A2 | A3 | SC | [A4] | [QC] */
382
383 len_a = a4_included ? 28 : 22;
384 if (qos_included)
385 len_a += 2;
386
387 aad[0] = 0; /* (len_a >> 8) & 0xff; */
388 aad[1] = len_a & 0xff;
389 /* Mask FC: zero subtype b4 b5 b6 */
390 aad[2] = fc_pos[0] & ~(BIT(4) | BIT(5) | BIT(6));
391 /* Retry, PwrMgt, MoreData; set Protected */
392 aad[3] = (fc_pos[1] & ~(BIT(3) | BIT(4) | BIT(5))) | BIT(6);
393 memcpy(&aad[4], &hdr->addr1, 18);
394
395 /* Mask Seq#, leave Frag# */
396 aad[22] = *((u8 *) &hdr->seq_ctrl) & 0x0f;
397 aad[23] = 0;
398 if (a4_included) {
399 memcpy(&aad[24], hdr->addr4, 6);
400 aad[30] = 0;
401 aad[31] = 0;
402 } else
403 memset(&aad[24], 0, 8);
404 if (qos_included) {
405 u8 *dpos = &aad[a4_included ? 30 : 24];
406
407 /* Mask QoS Control field */
408 dpos[0] = qos_tid;
409 dpos[1] = 0;
410 }
411}
412
413
414static inline void ccmp_pn2hdr(u8 *hdr, u8 *pn, int key_id)
415{
416 hdr[0] = pn[5];
417 hdr[1] = pn[4];
418 hdr[2] = 0;
419 hdr[3] = 0x20 | (key_id << 6);
420 hdr[4] = pn[3];
421 hdr[5] = pn[2];
422 hdr[6] = pn[1];
423 hdr[7] = pn[0];
424}
425
426
427static inline int ccmp_hdr2pn(u8 *pn, u8 *hdr)
428{
429 pn[0] = hdr[7];
430 pn[1] = hdr[6];
431 pn[2] = hdr[5];
432 pn[3] = hdr[4];
433 pn[4] = hdr[1];
434 pn[5] = hdr[0];
435 return (hdr[3] >> 6) & 0x03;
436}
437
438
439static int ccmp_encrypt_skb(struct ieee80211_txrx_data *tx,
440 struct sk_buff *skb, int test)
441{
442 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
443 struct ieee80211_key *key = tx->key;
444 int hdrlen, len, tailneed;
445 u16 fc;
446 u8 *pos, *pn, *b_0, *aad, *scratch;
447 int i;
448
449 scratch = key->u.ccmp.tx_crypto_buf;
450 b_0 = scratch + 3 * AES_BLOCK_LEN;
451 aad = scratch + 4 * AES_BLOCK_LEN;
452
453 fc = le16_to_cpu(hdr->frame_control);
454 hdrlen = ieee80211_get_hdrlen(fc);
455 len = skb->len - hdrlen;
456
457 if (key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE)
458 tailneed = 0;
459 else
460 tailneed = CCMP_MIC_LEN;
461
462 if ((skb_headroom(skb) < CCMP_HDR_LEN ||
463 skb_tailroom(skb) < tailneed)) {
464 I802_DEBUG_INC(tx->local->tx_expand_skb_head);
465 if (unlikely(pskb_expand_head(skb, CCMP_HDR_LEN, tailneed,
466 GFP_ATOMIC)))
467 return -1;
468 }
469
470 pos = skb_push(skb, CCMP_HDR_LEN);
471 memmove(pos, pos + CCMP_HDR_LEN, hdrlen);
472 hdr = (struct ieee80211_hdr *) pos;
473 pos += hdrlen;
474
475 /* PN = PN + 1 */
476 pn = key->u.ccmp.tx_pn;
477
478 for (i = CCMP_PN_LEN - 1; i >= 0; i--) {
479 pn[i]++;
480 if (pn[i])
481 break;
482 }
483
484 ccmp_pn2hdr(pos, pn, key->conf.keyidx);
485
486 if (key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE) {
487 /* hwaccel - with preallocated room for CCMP header */
488 tx->u.tx.control->key_idx = key->conf.hw_key_idx;
489 return 0;
490 }
491
492 pos += CCMP_HDR_LEN;
493 ccmp_special_blocks(skb, pn, b_0, aad, 0);
494 ieee80211_aes_ccm_encrypt(key->u.ccmp.tfm, scratch, b_0, aad, pos, len,
495 pos, skb_put(skb, CCMP_MIC_LEN));
496
497 return 0;
498}
499
500
501ieee80211_txrx_result
502ieee80211_crypto_ccmp_encrypt(struct ieee80211_txrx_data *tx)
503{
504 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) tx->skb->data;
505 u16 fc;
506 struct sk_buff *skb = tx->skb;
507 int test = 0;
508
509 fc = le16_to_cpu(hdr->frame_control);
510
511 if (!WLAN_FC_DATA_PRESENT(fc))
512 return TXRX_CONTINUE;
513
514 tx->u.tx.control->icv_len = CCMP_MIC_LEN;
515 tx->u.tx.control->iv_len = CCMP_HDR_LEN;
516 ieee80211_tx_set_iswep(tx);
517
518 if ((tx->key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE) &&
519 !(tx->key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_IV)) {
520 /* hwaccel - with no need for preallocated room for CCMP "
521 * header or MIC fields */
522 tx->u.tx.control->key_idx = tx->key->conf.hw_key_idx;
523 return TXRX_CONTINUE;
524 }
525
526 if (ccmp_encrypt_skb(tx, skb, test) < 0)
527 return TXRX_DROP;
528
529 if (tx->u.tx.extra_frag) {
530 int i;
531 for (i = 0; i < tx->u.tx.num_extra_frag; i++) {
532 if (ccmp_encrypt_skb(tx, tx->u.tx.extra_frag[i], test)
533 < 0)
534 return TXRX_DROP;
535 }
536 }
537
538 return TXRX_CONTINUE;
539}
540
541
542ieee80211_txrx_result
543ieee80211_crypto_ccmp_decrypt(struct ieee80211_txrx_data *rx)
544{
545 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) rx->skb->data;
546 u16 fc;
547 int hdrlen;
548 struct ieee80211_key *key = rx->key;
549 struct sk_buff *skb = rx->skb;
550 u8 pn[CCMP_PN_LEN];
551 int data_len;
552 DECLARE_MAC_BUF(mac);
553
554 fc = le16_to_cpu(hdr->frame_control);
555 hdrlen = ieee80211_get_hdrlen(fc);
556
557 if ((rx->fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_DATA)
558 return TXRX_CONTINUE;
559
560 data_len = skb->len - hdrlen - CCMP_HDR_LEN - CCMP_MIC_LEN;
561 if (!rx->sta || data_len < 0)
562 return TXRX_DROP;
563
564 if ((rx->u.rx.status->flag & RX_FLAG_DECRYPTED) &&
565 (rx->u.rx.status->flag & RX_FLAG_IV_STRIPPED))
566 return TXRX_CONTINUE;
567
568 (void) ccmp_hdr2pn(pn, skb->data + hdrlen);
569
570 if (memcmp(pn, key->u.ccmp.rx_pn[rx->u.rx.queue], CCMP_PN_LEN) <= 0) {
571#ifdef CONFIG_MAC80211_DEBUG
572 u8 *ppn = key->u.ccmp.rx_pn[rx->u.rx.queue];
573
574 printk(KERN_DEBUG "%s: CCMP replay detected for RX frame from "
575 "%s (RX PN %02x%02x%02x%02x%02x%02x <= prev. PN "
576 "%02x%02x%02x%02x%02x%02x)\n", rx->dev->name,
577 print_mac(mac, rx->sta->addr),
578 pn[0], pn[1], pn[2], pn[3], pn[4], pn[5],
579 ppn[0], ppn[1], ppn[2], ppn[3], ppn[4], ppn[5]);
580#endif /* CONFIG_MAC80211_DEBUG */
581 key->u.ccmp.replays++;
582 return TXRX_DROP;
583 }
584
585 if (!(rx->u.rx.status->flag & RX_FLAG_DECRYPTED)) {
586 /* hardware didn't decrypt/verify MIC */
587 u8 *scratch, *b_0, *aad;
588
589 scratch = key->u.ccmp.rx_crypto_buf;
590 b_0 = scratch + 3 * AES_BLOCK_LEN;
591 aad = scratch + 4 * AES_BLOCK_LEN;
592
593 ccmp_special_blocks(skb, pn, b_0, aad, 1);
594
595 if (ieee80211_aes_ccm_decrypt(
596 key->u.ccmp.tfm, scratch, b_0, aad,
597 skb->data + hdrlen + CCMP_HDR_LEN, data_len,
598 skb->data + skb->len - CCMP_MIC_LEN,
599 skb->data + hdrlen + CCMP_HDR_LEN)) {
600#ifdef CONFIG_MAC80211_DEBUG
601 if (net_ratelimit())
602 printk(KERN_DEBUG "%s: CCMP decrypt failed "
603 "for RX frame from %s\n", rx->dev->name,
604 print_mac(mac, rx->sta->addr));
605#endif /* CONFIG_MAC80211_DEBUG */
606 return TXRX_DROP;
607 }
608 }
609
610 memcpy(key->u.ccmp.rx_pn[rx->u.rx.queue], pn, CCMP_PN_LEN);
611
612 /* Remove CCMP header and MIC */
613 skb_trim(skb, skb->len - CCMP_MIC_LEN);
614 memmove(skb->data + CCMP_HDR_LEN, skb->data, hdrlen);
615 skb_pull(skb, CCMP_HDR_LEN);
616
617 return TXRX_CONTINUE;
618}