xref: /linux/net/mac80211/rx.c (revision 643d1f7fe3aa12c8bdea6fa5b4ba874ff6dd601d)
1 /*
2  * Copyright 2002-2005, Instant802 Networks, Inc.
3  * Copyright 2005-2006, Devicescape Software, Inc.
4  * Copyright 2006-2007	Jiri Benc <jbenc@suse.cz>
5  * Copyright 2007	Johannes Berg <johannes@sipsolutions.net>
6  *
7  * This program is free software; you can redistribute it and/or modify
8  * it under the terms of the GNU General Public License version 2 as
9  * published by the Free Software Foundation.
10  */
11 
12 #include <linux/kernel.h>
13 #include <linux/skbuff.h>
14 #include <linux/netdevice.h>
15 #include <linux/etherdevice.h>
16 #include <linux/rcupdate.h>
17 #include <net/mac80211.h>
18 #include <net/ieee80211_radiotap.h>
19 
20 #include "ieee80211_i.h"
21 #include "ieee80211_led.h"
22 #include "wep.h"
23 #include "wpa.h"
24 #include "tkip.h"
25 #include "wme.h"
26 
27 u8 ieee80211_sta_manage_reorder_buf(struct ieee80211_hw *hw,
28 				struct tid_ampdu_rx *tid_agg_rx,
29 				struct sk_buff *skb, u16 mpdu_seq_num,
30 				int bar_req);
31 /*
32  * monitor mode reception
33  *
34  * This function cleans up the SKB, i.e. it removes all the stuff
35  * only useful for monitoring.
36  */
37 static struct sk_buff *remove_monitor_info(struct ieee80211_local *local,
38 					   struct sk_buff *skb,
39 					   int rtap_len)
40 {
41 	skb_pull(skb, rtap_len);
42 
43 	if (local->hw.flags & IEEE80211_HW_RX_INCLUDES_FCS) {
44 		if (likely(skb->len > FCS_LEN))
45 			skb_trim(skb, skb->len - FCS_LEN);
46 		else {
47 			/* driver bug */
48 			WARN_ON(1);
49 			dev_kfree_skb(skb);
50 			skb = NULL;
51 		}
52 	}
53 
54 	return skb;
55 }
56 
57 static inline int should_drop_frame(struct ieee80211_rx_status *status,
58 				    struct sk_buff *skb,
59 				    int present_fcs_len,
60 				    int radiotap_len)
61 {
62 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
63 
64 	if (status->flag & (RX_FLAG_FAILED_FCS_CRC | RX_FLAG_FAILED_PLCP_CRC))
65 		return 1;
66 	if (unlikely(skb->len < 16 + present_fcs_len + radiotap_len))
67 		return 1;
68 	if (((hdr->frame_control & cpu_to_le16(IEEE80211_FCTL_FTYPE)) ==
69 			cpu_to_le16(IEEE80211_FTYPE_CTL)) &&
70 	    ((hdr->frame_control & cpu_to_le16(IEEE80211_FCTL_STYPE)) !=
71 			cpu_to_le16(IEEE80211_STYPE_PSPOLL)) &&
72 	    ((hdr->frame_control & cpu_to_le16(IEEE80211_FCTL_STYPE)) !=
73 			cpu_to_le16(IEEE80211_STYPE_BACK_REQ)))
74 		return 1;
75 	return 0;
76 }
77 
78 /*
79  * This function copies a received frame to all monitor interfaces and
80  * returns a cleaned-up SKB that no longer includes the FCS nor the
81  * radiotap header the driver might have added.
82  */
83 static struct sk_buff *
84 ieee80211_rx_monitor(struct ieee80211_local *local, struct sk_buff *origskb,
85 		     struct ieee80211_rx_status *status)
86 {
87 	struct ieee80211_sub_if_data *sdata;
88 	struct ieee80211_rate *rate;
89 	int needed_headroom = 0;
90 	struct ieee80211_radiotap_header *rthdr;
91 	__le64 *rttsft = NULL;
92 	struct ieee80211_rtap_fixed_data {
93 		u8 flags;
94 		u8 rate;
95 		__le16 chan_freq;
96 		__le16 chan_flags;
97 		u8 antsignal;
98 		u8 padding_for_rxflags;
99 		__le16 rx_flags;
100 	} __attribute__ ((packed)) *rtfixed;
101 	struct sk_buff *skb, *skb2;
102 	struct net_device *prev_dev = NULL;
103 	int present_fcs_len = 0;
104 	int rtap_len = 0;
105 
106 	/*
107 	 * First, we may need to make a copy of the skb because
108 	 *  (1) we need to modify it for radiotap (if not present), and
109 	 *  (2) the other RX handlers will modify the skb we got.
110 	 *
111 	 * We don't need to, of course, if we aren't going to return
112 	 * the SKB because it has a bad FCS/PLCP checksum.
113 	 */
114 	if (status->flag & RX_FLAG_RADIOTAP)
115 		rtap_len = ieee80211_get_radiotap_len(origskb->data);
116 	else
117 		/* room for radiotap header, always present fields and TSFT */
118 		needed_headroom = sizeof(*rthdr) + sizeof(*rtfixed) + 8;
119 
120 	if (local->hw.flags & IEEE80211_HW_RX_INCLUDES_FCS)
121 		present_fcs_len = FCS_LEN;
122 
123 	if (!local->monitors) {
124 		if (should_drop_frame(status, origskb, present_fcs_len,
125 				      rtap_len)) {
126 			dev_kfree_skb(origskb);
127 			return NULL;
128 		}
129 
130 		return remove_monitor_info(local, origskb, rtap_len);
131 	}
132 
133 	if (should_drop_frame(status, origskb, present_fcs_len, rtap_len)) {
134 		/* only need to expand headroom if necessary */
135 		skb = origskb;
136 		origskb = NULL;
137 
138 		/*
139 		 * This shouldn't trigger often because most devices have an
140 		 * RX header they pull before we get here, and that should
141 		 * be big enough for our radiotap information. We should
142 		 * probably export the length to drivers so that we can have
143 		 * them allocate enough headroom to start with.
144 		 */
145 		if (skb_headroom(skb) < needed_headroom &&
146 		    pskb_expand_head(skb, needed_headroom, 0, GFP_ATOMIC)) {
147 			dev_kfree_skb(skb);
148 			return NULL;
149 		}
150 	} else {
151 		/*
152 		 * Need to make a copy and possibly remove radiotap header
153 		 * and FCS from the original.
154 		 */
155 		skb = skb_copy_expand(origskb, needed_headroom, 0, GFP_ATOMIC);
156 
157 		origskb = remove_monitor_info(local, origskb, rtap_len);
158 
159 		if (!skb)
160 			return origskb;
161 	}
162 
163 	/* if necessary, prepend radiotap information */
164 	if (!(status->flag & RX_FLAG_RADIOTAP)) {
165 		rtfixed = (void *) skb_push(skb, sizeof(*rtfixed));
166 		rtap_len = sizeof(*rthdr) + sizeof(*rtfixed);
167 		if (status->flag & RX_FLAG_TSFT) {
168 			rttsft = (void *) skb_push(skb, sizeof(*rttsft));
169 			rtap_len += 8;
170 		}
171 		rthdr = (void *) skb_push(skb, sizeof(*rthdr));
172 		memset(rthdr, 0, sizeof(*rthdr));
173 		memset(rtfixed, 0, sizeof(*rtfixed));
174 		rthdr->it_present =
175 			cpu_to_le32((1 << IEEE80211_RADIOTAP_FLAGS) |
176 				    (1 << IEEE80211_RADIOTAP_RATE) |
177 				    (1 << IEEE80211_RADIOTAP_CHANNEL) |
178 				    (1 << IEEE80211_RADIOTAP_DB_ANTSIGNAL) |
179 				    (1 << IEEE80211_RADIOTAP_RX_FLAGS));
180 		rtfixed->flags = 0;
181 		if (local->hw.flags & IEEE80211_HW_RX_INCLUDES_FCS)
182 			rtfixed->flags |= IEEE80211_RADIOTAP_F_FCS;
183 
184 		if (rttsft) {
185 			*rttsft = cpu_to_le64(status->mactime);
186 			rthdr->it_present |=
187 				cpu_to_le32(1 << IEEE80211_RADIOTAP_TSFT);
188 		}
189 
190 		/* FIXME: when radiotap gets a 'bad PLCP' flag use it here */
191 		rtfixed->rx_flags = 0;
192 		if (status->flag &
193 		    (RX_FLAG_FAILED_FCS_CRC | RX_FLAG_FAILED_PLCP_CRC))
194 			rtfixed->rx_flags |=
195 				cpu_to_le16(IEEE80211_RADIOTAP_F_RX_BADFCS);
196 
197 		rate = ieee80211_get_rate(local, status->phymode,
198 					  status->rate);
199 		if (rate)
200 			rtfixed->rate = rate->rate / 5;
201 
202 		rtfixed->chan_freq = cpu_to_le16(status->freq);
203 
204 		if (status->phymode == MODE_IEEE80211A)
205 			rtfixed->chan_flags =
206 				cpu_to_le16(IEEE80211_CHAN_OFDM |
207 					    IEEE80211_CHAN_5GHZ);
208 		else
209 			rtfixed->chan_flags =
210 				cpu_to_le16(IEEE80211_CHAN_DYN |
211 					    IEEE80211_CHAN_2GHZ);
212 
213 		rtfixed->antsignal = status->ssi;
214 		rthdr->it_len = cpu_to_le16(rtap_len);
215 	}
216 
217 	skb_reset_mac_header(skb);
218 	skb->ip_summed = CHECKSUM_UNNECESSARY;
219 	skb->pkt_type = PACKET_OTHERHOST;
220 	skb->protocol = htons(ETH_P_802_2);
221 
222 	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
223 		if (!netif_running(sdata->dev))
224 			continue;
225 
226 		if (sdata->vif.type != IEEE80211_IF_TYPE_MNTR)
227 			continue;
228 
229 		if (prev_dev) {
230 			skb2 = skb_clone(skb, GFP_ATOMIC);
231 			if (skb2) {
232 				skb2->dev = prev_dev;
233 				netif_rx(skb2);
234 			}
235 		}
236 
237 		prev_dev = sdata->dev;
238 		sdata->dev->stats.rx_packets++;
239 		sdata->dev->stats.rx_bytes += skb->len;
240 	}
241 
242 	if (prev_dev) {
243 		skb->dev = prev_dev;
244 		netif_rx(skb);
245 	} else
246 		dev_kfree_skb(skb);
247 
248 	return origskb;
249 }
250 
251 
252 /* pre-rx handlers
253  *
254  * these don't have dev/sdata fields in the rx data
255  * The sta value should also not be used because it may
256  * be NULL even though a STA (in IBSS mode) will be added.
257  */
258 
259 static ieee80211_txrx_result
260 ieee80211_rx_h_parse_qos(struct ieee80211_txrx_data *rx)
261 {
262 	u8 *data = rx->skb->data;
263 	int tid;
264 
265 	/* does the frame have a qos control field? */
266 	if (WLAN_FC_IS_QOS_DATA(rx->fc)) {
267 		u8 *qc = data + ieee80211_get_hdrlen(rx->fc) - QOS_CONTROL_LEN;
268 		/* frame has qos control */
269 		tid = qc[0] & QOS_CONTROL_TID_MASK;
270 		if (qc[0] & IEEE80211_QOS_CONTROL_A_MSDU_PRESENT)
271 			rx->flags |= IEEE80211_TXRXD_RX_AMSDU;
272 		else
273 			rx->flags &= ~IEEE80211_TXRXD_RX_AMSDU;
274 	} else {
275 		if (unlikely((rx->fc & IEEE80211_FCTL_FTYPE) == IEEE80211_FTYPE_MGMT)) {
276 			/* Separate TID for management frames */
277 			tid = NUM_RX_DATA_QUEUES - 1;
278 		} else {
279 			/* no qos control present */
280 			tid = 0; /* 802.1d - Best Effort */
281 		}
282 	}
283 
284 	I802_DEBUG_INC(rx->local->wme_rx_queue[tid]);
285 	/* only a debug counter, sta might not be assigned properly yet */
286 	if (rx->sta)
287 		I802_DEBUG_INC(rx->sta->wme_rx_queue[tid]);
288 
289 	rx->u.rx.queue = tid;
290 	/* Set skb->priority to 1d tag if highest order bit of TID is not set.
291 	 * For now, set skb->priority to 0 for other cases. */
292 	rx->skb->priority = (tid > 7) ? 0 : tid;
293 
294 	return TXRX_CONTINUE;
295 }
296 
297 
298 static u32 ieee80211_rx_load_stats(struct ieee80211_local *local,
299 			      struct sk_buff *skb,
300 			      struct ieee80211_rx_status *status)
301 {
302 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
303 	u32 load = 0, hdrtime;
304 	struct ieee80211_rate *rate;
305 	struct ieee80211_hw_mode *mode = local->hw.conf.mode;
306 	int i;
307 
308 	/* Estimate total channel use caused by this frame */
309 
310 	if (unlikely(mode->num_rates < 0))
311 		return TXRX_CONTINUE;
312 
313 	rate = &mode->rates[0];
314 	for (i = 0; i < mode->num_rates; i++) {
315 		if (mode->rates[i].val == status->rate) {
316 			rate = &mode->rates[i];
317 			break;
318 		}
319 	}
320 
321 	/* 1 bit at 1 Mbit/s takes 1 usec; in channel_use values,
322 	 * 1 usec = 1/8 * (1080 / 10) = 13.5 */
323 
324 	if (mode->mode == MODE_IEEE80211A ||
325 	    (mode->mode == MODE_IEEE80211G &&
326 	     rate->flags & IEEE80211_RATE_ERP))
327 		hdrtime = CHAN_UTIL_HDR_SHORT;
328 	else
329 		hdrtime = CHAN_UTIL_HDR_LONG;
330 
331 	load = hdrtime;
332 	if (!is_multicast_ether_addr(hdr->addr1))
333 		load += hdrtime;
334 
335 	load += skb->len * rate->rate_inv;
336 
337 	/* Divide channel_use by 8 to avoid wrapping around the counter */
338 	load >>= CHAN_UTIL_SHIFT;
339 
340 	return load;
341 }
342 
343 static ieee80211_txrx_result
344 ieee80211_rx_h_verify_ip_alignment(struct ieee80211_txrx_data *rx)
345 {
346 	int hdrlen;
347 
348 	/*
349 	 * Drivers are required to align the payload data in a way that
350 	 * guarantees that the contained IP header is aligned to a four-
351 	 * byte boundary. In the case of regular frames, this simply means
352 	 * aligning the payload to a four-byte boundary (because either
353 	 * the IP header is directly contained, or IV/RFC1042 headers that
354 	 * have a length divisible by four are in front of it.
355 	 *
356 	 * With A-MSDU frames, however, the payload data address must
357 	 * yield two modulo four because there are 14-byte 802.3 headers
358 	 * within the A-MSDU frames that push the IP header further back
359 	 * to a multiple of four again. Thankfully, the specs were sane
360 	 * enough this time around to require padding each A-MSDU subframe
361 	 * to a length that is a multiple of four.
362 	 *
363 	 * Padding like atheros hardware adds which is inbetween the 802.11
364 	 * header and the payload is not supported, the driver is required
365 	 * to move the 802.11 header further back in that case.
366 	 */
367 	hdrlen = ieee80211_get_hdrlen(rx->fc);
368 	if (rx->flags & IEEE80211_TXRXD_RX_AMSDU)
369 		hdrlen += ETH_HLEN;
370 	WARN_ON_ONCE(((unsigned long)(rx->skb->data + hdrlen)) & 3);
371 
372 	return TXRX_CONTINUE;
373 }
374 
375 ieee80211_rx_handler ieee80211_rx_pre_handlers[] =
376 {
377 	ieee80211_rx_h_parse_qos,
378 	ieee80211_rx_h_verify_ip_alignment,
379 	NULL
380 };
381 
382 /* rx handlers */
383 
384 static ieee80211_txrx_result
385 ieee80211_rx_h_if_stats(struct ieee80211_txrx_data *rx)
386 {
387 	if (rx->sta)
388 		rx->sta->channel_use_raw += rx->u.rx.load;
389 	rx->sdata->channel_use_raw += rx->u.rx.load;
390 	return TXRX_CONTINUE;
391 }
392 
393 static ieee80211_txrx_result
394 ieee80211_rx_h_passive_scan(struct ieee80211_txrx_data *rx)
395 {
396 	struct ieee80211_local *local = rx->local;
397 	struct sk_buff *skb = rx->skb;
398 
399 	if (unlikely(local->sta_hw_scanning))
400 		return ieee80211_sta_rx_scan(rx->dev, skb, rx->u.rx.status);
401 
402 	if (unlikely(local->sta_sw_scanning)) {
403 		/* drop all the other packets during a software scan anyway */
404 		if (ieee80211_sta_rx_scan(rx->dev, skb, rx->u.rx.status)
405 		    != TXRX_QUEUED)
406 			dev_kfree_skb(skb);
407 		return TXRX_QUEUED;
408 	}
409 
410 	if (unlikely(rx->flags & IEEE80211_TXRXD_RXIN_SCAN)) {
411 		/* scanning finished during invoking of handlers */
412 		I802_DEBUG_INC(local->rx_handlers_drop_passive_scan);
413 		return TXRX_DROP;
414 	}
415 
416 	return TXRX_CONTINUE;
417 }
418 
419 static ieee80211_txrx_result
420 ieee80211_rx_h_check(struct ieee80211_txrx_data *rx)
421 {
422 	struct ieee80211_hdr *hdr;
423 	hdr = (struct ieee80211_hdr *) rx->skb->data;
424 
425 	/* Drop duplicate 802.11 retransmissions (IEEE 802.11 Chap. 9.2.9) */
426 	if (rx->sta && !is_multicast_ether_addr(hdr->addr1)) {
427 		if (unlikely(rx->fc & IEEE80211_FCTL_RETRY &&
428 			     rx->sta->last_seq_ctrl[rx->u.rx.queue] ==
429 			     hdr->seq_ctrl)) {
430 			if (rx->flags & IEEE80211_TXRXD_RXRA_MATCH) {
431 				rx->local->dot11FrameDuplicateCount++;
432 				rx->sta->num_duplicates++;
433 			}
434 			return TXRX_DROP;
435 		} else
436 			rx->sta->last_seq_ctrl[rx->u.rx.queue] = hdr->seq_ctrl;
437 	}
438 
439 	if (unlikely(rx->skb->len < 16)) {
440 		I802_DEBUG_INC(rx->local->rx_handlers_drop_short);
441 		return TXRX_DROP;
442 	}
443 
444 	/* Drop disallowed frame classes based on STA auth/assoc state;
445 	 * IEEE 802.11, Chap 5.5.
446 	 *
447 	 * 80211.o does filtering only based on association state, i.e., it
448 	 * drops Class 3 frames from not associated stations. hostapd sends
449 	 * deauth/disassoc frames when needed. In addition, hostapd is
450 	 * responsible for filtering on both auth and assoc states.
451 	 */
452 	if (unlikely(((rx->fc & IEEE80211_FCTL_FTYPE) == IEEE80211_FTYPE_DATA ||
453 		      ((rx->fc & IEEE80211_FCTL_FTYPE) == IEEE80211_FTYPE_CTL &&
454 		       (rx->fc & IEEE80211_FCTL_STYPE) == IEEE80211_STYPE_PSPOLL)) &&
455 		     rx->sdata->vif.type != IEEE80211_IF_TYPE_IBSS &&
456 		     (!rx->sta || !(rx->sta->flags & WLAN_STA_ASSOC)))) {
457 		if ((!(rx->fc & IEEE80211_FCTL_FROMDS) &&
458 		     !(rx->fc & IEEE80211_FCTL_TODS) &&
459 		     (rx->fc & IEEE80211_FCTL_FTYPE) == IEEE80211_FTYPE_DATA)
460 		    || !(rx->flags & IEEE80211_TXRXD_RXRA_MATCH)) {
461 			/* Drop IBSS frames and frames for other hosts
462 			 * silently. */
463 			return TXRX_DROP;
464 		}
465 
466 		return TXRX_DROP;
467 	}
468 
469 	return TXRX_CONTINUE;
470 }
471 
472 
473 static ieee80211_txrx_result
474 ieee80211_rx_h_decrypt(struct ieee80211_txrx_data *rx)
475 {
476 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) rx->skb->data;
477 	int keyidx;
478 	int hdrlen;
479 	ieee80211_txrx_result result = TXRX_DROP;
480 	struct ieee80211_key *stakey = NULL;
481 
482 	/*
483 	 * Key selection 101
484 	 *
485 	 * There are three types of keys:
486 	 *  - GTK (group keys)
487 	 *  - PTK (pairwise keys)
488 	 *  - STK (station-to-station pairwise keys)
489 	 *
490 	 * When selecting a key, we have to distinguish between multicast
491 	 * (including broadcast) and unicast frames, the latter can only
492 	 * use PTKs and STKs while the former always use GTKs. Unless, of
493 	 * course, actual WEP keys ("pre-RSNA") are used, then unicast
494 	 * frames can also use key indizes like GTKs. Hence, if we don't
495 	 * have a PTK/STK we check the key index for a WEP key.
496 	 *
497 	 * Note that in a regular BSS, multicast frames are sent by the
498 	 * AP only, associated stations unicast the frame to the AP first
499 	 * which then multicasts it on their behalf.
500 	 *
501 	 * There is also a slight problem in IBSS mode: GTKs are negotiated
502 	 * with each station, that is something we don't currently handle.
503 	 * The spec seems to expect that one negotiates the same key with
504 	 * every station but there's no such requirement; VLANs could be
505 	 * possible.
506 	 */
507 
508 	if (!(rx->fc & IEEE80211_FCTL_PROTECTED))
509 		return TXRX_CONTINUE;
510 
511 	/*
512 	 * No point in finding a key and decrypting if the frame is neither
513 	 * addressed to us nor a multicast frame.
514 	 */
515 	if (!(rx->flags & IEEE80211_TXRXD_RXRA_MATCH))
516 		return TXRX_CONTINUE;
517 
518 	if (rx->sta)
519 		stakey = rcu_dereference(rx->sta->key);
520 
521 	if (!is_multicast_ether_addr(hdr->addr1) && stakey) {
522 		rx->key = stakey;
523 	} else {
524 		/*
525 		 * The device doesn't give us the IV so we won't be
526 		 * able to look up the key. That's ok though, we
527 		 * don't need to decrypt the frame, we just won't
528 		 * be able to keep statistics accurate.
529 		 * Except for key threshold notifications, should
530 		 * we somehow allow the driver to tell us which key
531 		 * the hardware used if this flag is set?
532 		 */
533 		if ((rx->u.rx.status->flag & RX_FLAG_DECRYPTED) &&
534 		    (rx->u.rx.status->flag & RX_FLAG_IV_STRIPPED))
535 			return TXRX_CONTINUE;
536 
537 		hdrlen = ieee80211_get_hdrlen(rx->fc);
538 
539 		if (rx->skb->len < 8 + hdrlen)
540 			return TXRX_DROP; /* TODO: count this? */
541 
542 		/*
543 		 * no need to call ieee80211_wep_get_keyidx,
544 		 * it verifies a bunch of things we've done already
545 		 */
546 		keyidx = rx->skb->data[hdrlen + 3] >> 6;
547 
548 		rx->key = rcu_dereference(rx->sdata->keys[keyidx]);
549 
550 		/*
551 		 * RSNA-protected unicast frames should always be sent with
552 		 * pairwise or station-to-station keys, but for WEP we allow
553 		 * using a key index as well.
554 		 */
555 		if (rx->key && rx->key->conf.alg != ALG_WEP &&
556 		    !is_multicast_ether_addr(hdr->addr1))
557 			rx->key = NULL;
558 	}
559 
560 	if (rx->key) {
561 		rx->key->tx_rx_count++;
562 		/* TODO: add threshold stuff again */
563 	} else {
564 #ifdef CONFIG_MAC80211_DEBUG
565 		if (net_ratelimit())
566 			printk(KERN_DEBUG "%s: RX protected frame,"
567 			       " but have no key\n", rx->dev->name);
568 #endif /* CONFIG_MAC80211_DEBUG */
569 		return TXRX_DROP;
570 	}
571 
572 	/* Check for weak IVs if possible */
573 	if (rx->sta && rx->key->conf.alg == ALG_WEP &&
574 	    ((rx->fc & IEEE80211_FCTL_FTYPE) == IEEE80211_FTYPE_DATA) &&
575 	    (!(rx->u.rx.status->flag & RX_FLAG_IV_STRIPPED) ||
576 	     !(rx->u.rx.status->flag & RX_FLAG_DECRYPTED)) &&
577 	    ieee80211_wep_is_weak_iv(rx->skb, rx->key))
578 		rx->sta->wep_weak_iv_count++;
579 
580 	switch (rx->key->conf.alg) {
581 	case ALG_WEP:
582 		result = ieee80211_crypto_wep_decrypt(rx);
583 		break;
584 	case ALG_TKIP:
585 		result = ieee80211_crypto_tkip_decrypt(rx);
586 		break;
587 	case ALG_CCMP:
588 		result = ieee80211_crypto_ccmp_decrypt(rx);
589 		break;
590 	}
591 
592 	/* either the frame has been decrypted or will be dropped */
593 	rx->u.rx.status->flag |= RX_FLAG_DECRYPTED;
594 
595 	return result;
596 }
597 
598 static void ap_sta_ps_start(struct net_device *dev, struct sta_info *sta)
599 {
600 	struct ieee80211_sub_if_data *sdata;
601 	DECLARE_MAC_BUF(mac);
602 
603 	sdata = IEEE80211_DEV_TO_SUB_IF(sta->dev);
604 
605 	if (sdata->bss)
606 		atomic_inc(&sdata->bss->num_sta_ps);
607 	sta->flags |= WLAN_STA_PS;
608 	sta->pspoll = 0;
609 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
610 	printk(KERN_DEBUG "%s: STA %s aid %d enters power save mode\n",
611 	       dev->name, print_mac(mac, sta->addr), sta->aid);
612 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
613 }
614 
615 static int ap_sta_ps_end(struct net_device *dev, struct sta_info *sta)
616 {
617 	struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
618 	struct sk_buff *skb;
619 	int sent = 0;
620 	struct ieee80211_sub_if_data *sdata;
621 	struct ieee80211_tx_packet_data *pkt_data;
622 	DECLARE_MAC_BUF(mac);
623 
624 	sdata = IEEE80211_DEV_TO_SUB_IF(sta->dev);
625 	if (sdata->bss)
626 		atomic_dec(&sdata->bss->num_sta_ps);
627 	sta->flags &= ~(WLAN_STA_PS | WLAN_STA_TIM);
628 	sta->pspoll = 0;
629 	if (!skb_queue_empty(&sta->ps_tx_buf)) {
630 		if (local->ops->set_tim)
631 			local->ops->set_tim(local_to_hw(local), sta->aid, 0);
632 		if (sdata->bss)
633 			bss_tim_clear(local, sdata->bss, sta->aid);
634 	}
635 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
636 	printk(KERN_DEBUG "%s: STA %s aid %d exits power save mode\n",
637 	       dev->name, print_mac(mac, sta->addr), sta->aid);
638 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
639 	/* Send all buffered frames to the station */
640 	while ((skb = skb_dequeue(&sta->tx_filtered)) != NULL) {
641 		pkt_data = (struct ieee80211_tx_packet_data *) skb->cb;
642 		sent++;
643 		pkt_data->flags |= IEEE80211_TXPD_REQUEUE;
644 		dev_queue_xmit(skb);
645 	}
646 	while ((skb = skb_dequeue(&sta->ps_tx_buf)) != NULL) {
647 		pkt_data = (struct ieee80211_tx_packet_data *) skb->cb;
648 		local->total_ps_buffered--;
649 		sent++;
650 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
651 		printk(KERN_DEBUG "%s: STA %s aid %d send PS frame "
652 		       "since STA not sleeping anymore\n", dev->name,
653 		       print_mac(mac, sta->addr), sta->aid);
654 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
655 		pkt_data->flags |= IEEE80211_TXPD_REQUEUE;
656 		dev_queue_xmit(skb);
657 	}
658 
659 	return sent;
660 }
661 
662 static ieee80211_txrx_result
663 ieee80211_rx_h_sta_process(struct ieee80211_txrx_data *rx)
664 {
665 	struct sta_info *sta = rx->sta;
666 	struct net_device *dev = rx->dev;
667 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) rx->skb->data;
668 
669 	if (!sta)
670 		return TXRX_CONTINUE;
671 
672 	/* Update last_rx only for IBSS packets which are for the current
673 	 * BSSID to avoid keeping the current IBSS network alive in cases where
674 	 * other STAs are using different BSSID. */
675 	if (rx->sdata->vif.type == IEEE80211_IF_TYPE_IBSS) {
676 		u8 *bssid = ieee80211_get_bssid(hdr, rx->skb->len,
677 						IEEE80211_IF_TYPE_IBSS);
678 		if (compare_ether_addr(bssid, rx->sdata->u.sta.bssid) == 0)
679 			sta->last_rx = jiffies;
680 	} else
681 	if (!is_multicast_ether_addr(hdr->addr1) ||
682 	    rx->sdata->vif.type == IEEE80211_IF_TYPE_STA) {
683 		/* Update last_rx only for unicast frames in order to prevent
684 		 * the Probe Request frames (the only broadcast frames from a
685 		 * STA in infrastructure mode) from keeping a connection alive.
686 		 */
687 		sta->last_rx = jiffies;
688 	}
689 
690 	if (!(rx->flags & IEEE80211_TXRXD_RXRA_MATCH))
691 		return TXRX_CONTINUE;
692 
693 	sta->rx_fragments++;
694 	sta->rx_bytes += rx->skb->len;
695 	sta->last_rssi = rx->u.rx.status->ssi;
696 	sta->last_signal = rx->u.rx.status->signal;
697 	sta->last_noise = rx->u.rx.status->noise;
698 
699 	if (!(rx->fc & IEEE80211_FCTL_MOREFRAGS)) {
700 		/* Change STA power saving mode only in the end of a frame
701 		 * exchange sequence */
702 		if ((sta->flags & WLAN_STA_PS) && !(rx->fc & IEEE80211_FCTL_PM))
703 			rx->u.rx.sent_ps_buffered += ap_sta_ps_end(dev, sta);
704 		else if (!(sta->flags & WLAN_STA_PS) &&
705 			 (rx->fc & IEEE80211_FCTL_PM))
706 			ap_sta_ps_start(dev, sta);
707 	}
708 
709 	/* Drop data::nullfunc frames silently, since they are used only to
710 	 * control station power saving mode. */
711 	if ((rx->fc & IEEE80211_FCTL_FTYPE) == IEEE80211_FTYPE_DATA &&
712 	    (rx->fc & IEEE80211_FCTL_STYPE) == IEEE80211_STYPE_NULLFUNC) {
713 		I802_DEBUG_INC(rx->local->rx_handlers_drop_nullfunc);
714 		/* Update counter and free packet here to avoid counting this
715 		 * as a dropped packed. */
716 		sta->rx_packets++;
717 		dev_kfree_skb(rx->skb);
718 		return TXRX_QUEUED;
719 	}
720 
721 	return TXRX_CONTINUE;
722 } /* ieee80211_rx_h_sta_process */
723 
724 static inline struct ieee80211_fragment_entry *
725 ieee80211_reassemble_add(struct ieee80211_sub_if_data *sdata,
726 			 unsigned int frag, unsigned int seq, int rx_queue,
727 			 struct sk_buff **skb)
728 {
729 	struct ieee80211_fragment_entry *entry;
730 	int idx;
731 
732 	idx = sdata->fragment_next;
733 	entry = &sdata->fragments[sdata->fragment_next++];
734 	if (sdata->fragment_next >= IEEE80211_FRAGMENT_MAX)
735 		sdata->fragment_next = 0;
736 
737 	if (!skb_queue_empty(&entry->skb_list)) {
738 #ifdef CONFIG_MAC80211_DEBUG
739 		struct ieee80211_hdr *hdr =
740 			(struct ieee80211_hdr *) entry->skb_list.next->data;
741 		DECLARE_MAC_BUF(mac);
742 		DECLARE_MAC_BUF(mac2);
743 		printk(KERN_DEBUG "%s: RX reassembly removed oldest "
744 		       "fragment entry (idx=%d age=%lu seq=%d last_frag=%d "
745 		       "addr1=%s addr2=%s\n",
746 		       sdata->dev->name, idx,
747 		       jiffies - entry->first_frag_time, entry->seq,
748 		       entry->last_frag, print_mac(mac, hdr->addr1),
749 		       print_mac(mac2, hdr->addr2));
750 #endif /* CONFIG_MAC80211_DEBUG */
751 		__skb_queue_purge(&entry->skb_list);
752 	}
753 
754 	__skb_queue_tail(&entry->skb_list, *skb); /* no need for locking */
755 	*skb = NULL;
756 	entry->first_frag_time = jiffies;
757 	entry->seq = seq;
758 	entry->rx_queue = rx_queue;
759 	entry->last_frag = frag;
760 	entry->ccmp = 0;
761 	entry->extra_len = 0;
762 
763 	return entry;
764 }
765 
766 static inline struct ieee80211_fragment_entry *
767 ieee80211_reassemble_find(struct ieee80211_sub_if_data *sdata,
768 			  u16 fc, unsigned int frag, unsigned int seq,
769 			  int rx_queue, struct ieee80211_hdr *hdr)
770 {
771 	struct ieee80211_fragment_entry *entry;
772 	int i, idx;
773 
774 	idx = sdata->fragment_next;
775 	for (i = 0; i < IEEE80211_FRAGMENT_MAX; i++) {
776 		struct ieee80211_hdr *f_hdr;
777 		u16 f_fc;
778 
779 		idx--;
780 		if (idx < 0)
781 			idx = IEEE80211_FRAGMENT_MAX - 1;
782 
783 		entry = &sdata->fragments[idx];
784 		if (skb_queue_empty(&entry->skb_list) || entry->seq != seq ||
785 		    entry->rx_queue != rx_queue ||
786 		    entry->last_frag + 1 != frag)
787 			continue;
788 
789 		f_hdr = (struct ieee80211_hdr *) entry->skb_list.next->data;
790 		f_fc = le16_to_cpu(f_hdr->frame_control);
791 
792 		if ((fc & IEEE80211_FCTL_FTYPE) != (f_fc & IEEE80211_FCTL_FTYPE) ||
793 		    compare_ether_addr(hdr->addr1, f_hdr->addr1) != 0 ||
794 		    compare_ether_addr(hdr->addr2, f_hdr->addr2) != 0)
795 			continue;
796 
797 		if (entry->first_frag_time + 2 * HZ < jiffies) {
798 			__skb_queue_purge(&entry->skb_list);
799 			continue;
800 		}
801 		return entry;
802 	}
803 
804 	return NULL;
805 }
806 
807 static ieee80211_txrx_result
808 ieee80211_rx_h_defragment(struct ieee80211_txrx_data *rx)
809 {
810 	struct ieee80211_hdr *hdr;
811 	u16 sc;
812 	unsigned int frag, seq;
813 	struct ieee80211_fragment_entry *entry;
814 	struct sk_buff *skb;
815 	DECLARE_MAC_BUF(mac);
816 
817 	hdr = (struct ieee80211_hdr *) rx->skb->data;
818 	sc = le16_to_cpu(hdr->seq_ctrl);
819 	frag = sc & IEEE80211_SCTL_FRAG;
820 
821 	if (likely((!(rx->fc & IEEE80211_FCTL_MOREFRAGS) && frag == 0) ||
822 		   (rx->skb)->len < 24 ||
823 		   is_multicast_ether_addr(hdr->addr1))) {
824 		/* not fragmented */
825 		goto out;
826 	}
827 	I802_DEBUG_INC(rx->local->rx_handlers_fragments);
828 
829 	seq = (sc & IEEE80211_SCTL_SEQ) >> 4;
830 
831 	if (frag == 0) {
832 		/* This is the first fragment of a new frame. */
833 		entry = ieee80211_reassemble_add(rx->sdata, frag, seq,
834 						 rx->u.rx.queue, &(rx->skb));
835 		if (rx->key && rx->key->conf.alg == ALG_CCMP &&
836 		    (rx->fc & IEEE80211_FCTL_PROTECTED)) {
837 			/* Store CCMP PN so that we can verify that the next
838 			 * fragment has a sequential PN value. */
839 			entry->ccmp = 1;
840 			memcpy(entry->last_pn,
841 			       rx->key->u.ccmp.rx_pn[rx->u.rx.queue],
842 			       CCMP_PN_LEN);
843 		}
844 		return TXRX_QUEUED;
845 	}
846 
847 	/* This is a fragment for a frame that should already be pending in
848 	 * fragment cache. Add this fragment to the end of the pending entry.
849 	 */
850 	entry = ieee80211_reassemble_find(rx->sdata, rx->fc, frag, seq,
851 					  rx->u.rx.queue, hdr);
852 	if (!entry) {
853 		I802_DEBUG_INC(rx->local->rx_handlers_drop_defrag);
854 		return TXRX_DROP;
855 	}
856 
857 	/* Verify that MPDUs within one MSDU have sequential PN values.
858 	 * (IEEE 802.11i, 8.3.3.4.5) */
859 	if (entry->ccmp) {
860 		int i;
861 		u8 pn[CCMP_PN_LEN], *rpn;
862 		if (!rx->key || rx->key->conf.alg != ALG_CCMP)
863 			return TXRX_DROP;
864 		memcpy(pn, entry->last_pn, CCMP_PN_LEN);
865 		for (i = CCMP_PN_LEN - 1; i >= 0; i--) {
866 			pn[i]++;
867 			if (pn[i])
868 				break;
869 		}
870 		rpn = rx->key->u.ccmp.rx_pn[rx->u.rx.queue];
871 		if (memcmp(pn, rpn, CCMP_PN_LEN) != 0) {
872 			if (net_ratelimit())
873 				printk(KERN_DEBUG "%s: defrag: CCMP PN not "
874 				       "sequential A2=%s"
875 				       " PN=%02x%02x%02x%02x%02x%02x "
876 				       "(expected %02x%02x%02x%02x%02x%02x)\n",
877 				       rx->dev->name, print_mac(mac, hdr->addr2),
878 				       rpn[0], rpn[1], rpn[2], rpn[3], rpn[4],
879 				       rpn[5], pn[0], pn[1], pn[2], pn[3],
880 				       pn[4], pn[5]);
881 			return TXRX_DROP;
882 		}
883 		memcpy(entry->last_pn, pn, CCMP_PN_LEN);
884 	}
885 
886 	skb_pull(rx->skb, ieee80211_get_hdrlen(rx->fc));
887 	__skb_queue_tail(&entry->skb_list, rx->skb);
888 	entry->last_frag = frag;
889 	entry->extra_len += rx->skb->len;
890 	if (rx->fc & IEEE80211_FCTL_MOREFRAGS) {
891 		rx->skb = NULL;
892 		return TXRX_QUEUED;
893 	}
894 
895 	rx->skb = __skb_dequeue(&entry->skb_list);
896 	if (skb_tailroom(rx->skb) < entry->extra_len) {
897 		I802_DEBUG_INC(rx->local->rx_expand_skb_head2);
898 		if (unlikely(pskb_expand_head(rx->skb, 0, entry->extra_len,
899 					      GFP_ATOMIC))) {
900 			I802_DEBUG_INC(rx->local->rx_handlers_drop_defrag);
901 			__skb_queue_purge(&entry->skb_list);
902 			return TXRX_DROP;
903 		}
904 	}
905 	while ((skb = __skb_dequeue(&entry->skb_list))) {
906 		memcpy(skb_put(rx->skb, skb->len), skb->data, skb->len);
907 		dev_kfree_skb(skb);
908 	}
909 
910 	/* Complete frame has been reassembled - process it now */
911 	rx->flags |= IEEE80211_TXRXD_FRAGMENTED;
912 
913  out:
914 	if (rx->sta)
915 		rx->sta->rx_packets++;
916 	if (is_multicast_ether_addr(hdr->addr1))
917 		rx->local->dot11MulticastReceivedFrameCount++;
918 	else
919 		ieee80211_led_rx(rx->local);
920 	return TXRX_CONTINUE;
921 }
922 
923 static ieee80211_txrx_result
924 ieee80211_rx_h_ps_poll(struct ieee80211_txrx_data *rx)
925 {
926 	struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(rx->dev);
927 	struct sk_buff *skb;
928 	int no_pending_pkts;
929 	DECLARE_MAC_BUF(mac);
930 
931 	if (likely(!rx->sta ||
932 		   (rx->fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_CTL ||
933 		   (rx->fc & IEEE80211_FCTL_STYPE) != IEEE80211_STYPE_PSPOLL ||
934 		   !(rx->flags & IEEE80211_TXRXD_RXRA_MATCH)))
935 		return TXRX_CONTINUE;
936 
937 	if ((sdata->vif.type != IEEE80211_IF_TYPE_AP) &&
938 	    (sdata->vif.type != IEEE80211_IF_TYPE_VLAN))
939 		return TXRX_DROP;
940 
941 	skb = skb_dequeue(&rx->sta->tx_filtered);
942 	if (!skb) {
943 		skb = skb_dequeue(&rx->sta->ps_tx_buf);
944 		if (skb)
945 			rx->local->total_ps_buffered--;
946 	}
947 	no_pending_pkts = skb_queue_empty(&rx->sta->tx_filtered) &&
948 		skb_queue_empty(&rx->sta->ps_tx_buf);
949 
950 	if (skb) {
951 		struct ieee80211_hdr *hdr =
952 			(struct ieee80211_hdr *) skb->data;
953 
954 		/* tell TX path to send one frame even though the STA may
955 		 * still remain is PS mode after this frame exchange */
956 		rx->sta->pspoll = 1;
957 
958 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
959 		printk(KERN_DEBUG "STA %s aid %d: PS Poll (entries after %d)\n",
960 		       print_mac(mac, rx->sta->addr), rx->sta->aid,
961 		       skb_queue_len(&rx->sta->ps_tx_buf));
962 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
963 
964 		/* Use MoreData flag to indicate whether there are more
965 		 * buffered frames for this STA */
966 		if (no_pending_pkts) {
967 			hdr->frame_control &= cpu_to_le16(~IEEE80211_FCTL_MOREDATA);
968 			rx->sta->flags &= ~WLAN_STA_TIM;
969 		} else
970 			hdr->frame_control |= cpu_to_le16(IEEE80211_FCTL_MOREDATA);
971 
972 		dev_queue_xmit(skb);
973 
974 		if (no_pending_pkts) {
975 			if (rx->local->ops->set_tim)
976 				rx->local->ops->set_tim(local_to_hw(rx->local),
977 						       rx->sta->aid, 0);
978 			if (rx->sdata->bss)
979 				bss_tim_clear(rx->local, rx->sdata->bss, rx->sta->aid);
980 		}
981 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
982 	} else if (!rx->u.rx.sent_ps_buffered) {
983 		printk(KERN_DEBUG "%s: STA %s sent PS Poll even "
984 		       "though there is no buffered frames for it\n",
985 		       rx->dev->name, print_mac(mac, rx->sta->addr));
986 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
987 
988 	}
989 
990 	/* Free PS Poll skb here instead of returning TXRX_DROP that would
991 	 * count as an dropped frame. */
992 	dev_kfree_skb(rx->skb);
993 
994 	return TXRX_QUEUED;
995 }
996 
997 static ieee80211_txrx_result
998 ieee80211_rx_h_remove_qos_control(struct ieee80211_txrx_data *rx)
999 {
1000 	u16 fc = rx->fc;
1001 	u8 *data = rx->skb->data;
1002 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) data;
1003 
1004 	if (!WLAN_FC_IS_QOS_DATA(fc))
1005 		return TXRX_CONTINUE;
1006 
1007 	/* remove the qos control field, update frame type and meta-data */
1008 	memmove(data + 2, data, ieee80211_get_hdrlen(fc) - 2);
1009 	hdr = (struct ieee80211_hdr *) skb_pull(rx->skb, 2);
1010 	/* change frame type to non QOS */
1011 	rx->fc = fc &= ~IEEE80211_STYPE_QOS_DATA;
1012 	hdr->frame_control = cpu_to_le16(fc);
1013 
1014 	return TXRX_CONTINUE;
1015 }
1016 
1017 static int
1018 ieee80211_802_1x_port_control(struct ieee80211_txrx_data *rx)
1019 {
1020 	if (unlikely(rx->sdata->ieee802_1x_pac &&
1021 		     (!rx->sta || !(rx->sta->flags & WLAN_STA_AUTHORIZED)))) {
1022 #ifdef CONFIG_MAC80211_DEBUG
1023 		printk(KERN_DEBUG "%s: dropped frame "
1024 		       "(unauthorized port)\n", rx->dev->name);
1025 #endif /* CONFIG_MAC80211_DEBUG */
1026 		return -EACCES;
1027 	}
1028 
1029 	return 0;
1030 }
1031 
1032 static int
1033 ieee80211_drop_unencrypted(struct ieee80211_txrx_data *rx)
1034 {
1035 	/*
1036 	 * Pass through unencrypted frames if the hardware has
1037 	 * decrypted them already.
1038 	 */
1039 	if (rx->u.rx.status->flag & RX_FLAG_DECRYPTED)
1040 		return 0;
1041 
1042 	/* Drop unencrypted frames if key is set. */
1043 	if (unlikely(!(rx->fc & IEEE80211_FCTL_PROTECTED) &&
1044 		     (rx->fc & IEEE80211_FCTL_FTYPE) == IEEE80211_FTYPE_DATA &&
1045 		     (rx->fc & IEEE80211_FCTL_STYPE) != IEEE80211_STYPE_NULLFUNC &&
1046 		     (rx->key || rx->sdata->drop_unencrypted))) {
1047 		if (net_ratelimit())
1048 			printk(KERN_DEBUG "%s: RX non-WEP frame, but expected "
1049 			       "encryption\n", rx->dev->name);
1050 		return -EACCES;
1051 	}
1052 	return 0;
1053 }
1054 
1055 static int
1056 ieee80211_data_to_8023(struct ieee80211_txrx_data *rx)
1057 {
1058 	struct net_device *dev = rx->dev;
1059 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) rx->skb->data;
1060 	u16 fc, hdrlen, ethertype;
1061 	u8 *payload;
1062 	u8 dst[ETH_ALEN];
1063 	u8 src[ETH_ALEN];
1064 	struct sk_buff *skb = rx->skb;
1065 	struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
1066 	DECLARE_MAC_BUF(mac);
1067 	DECLARE_MAC_BUF(mac2);
1068 	DECLARE_MAC_BUF(mac3);
1069 	DECLARE_MAC_BUF(mac4);
1070 
1071 	fc = rx->fc;
1072 
1073 	if (unlikely(!WLAN_FC_DATA_PRESENT(fc)))
1074 		return -1;
1075 
1076 	hdrlen = ieee80211_get_hdrlen(fc);
1077 
1078 	/* convert IEEE 802.11 header + possible LLC headers into Ethernet
1079 	 * header
1080 	 * IEEE 802.11 address fields:
1081 	 * ToDS FromDS Addr1 Addr2 Addr3 Addr4
1082 	 *   0     0   DA    SA    BSSID n/a
1083 	 *   0     1   DA    BSSID SA    n/a
1084 	 *   1     0   BSSID SA    DA    n/a
1085 	 *   1     1   RA    TA    DA    SA
1086 	 */
1087 
1088 	switch (fc & (IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS)) {
1089 	case IEEE80211_FCTL_TODS:
1090 		/* BSSID SA DA */
1091 		memcpy(dst, hdr->addr3, ETH_ALEN);
1092 		memcpy(src, hdr->addr2, ETH_ALEN);
1093 
1094 		if (unlikely(sdata->vif.type != IEEE80211_IF_TYPE_AP &&
1095 			     sdata->vif.type != IEEE80211_IF_TYPE_VLAN)) {
1096 			if (net_ratelimit())
1097 				printk(KERN_DEBUG "%s: dropped ToDS frame "
1098 				       "(BSSID=%s SA=%s DA=%s)\n",
1099 				       dev->name,
1100 				       print_mac(mac, hdr->addr1),
1101 				       print_mac(mac2, hdr->addr2),
1102 				       print_mac(mac3, hdr->addr3));
1103 			return -1;
1104 		}
1105 		break;
1106 	case (IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS):
1107 		/* RA TA DA SA */
1108 		memcpy(dst, hdr->addr3, ETH_ALEN);
1109 		memcpy(src, hdr->addr4, ETH_ALEN);
1110 
1111 		if (unlikely(sdata->vif.type != IEEE80211_IF_TYPE_WDS)) {
1112 			if (net_ratelimit())
1113 				printk(KERN_DEBUG "%s: dropped FromDS&ToDS "
1114 				       "frame (RA=%s TA=%s DA=%s SA=%s)\n",
1115 				       rx->dev->name,
1116 				       print_mac(mac, hdr->addr1),
1117 				       print_mac(mac2, hdr->addr2),
1118 				       print_mac(mac3, hdr->addr3),
1119 				       print_mac(mac4, hdr->addr4));
1120 			return -1;
1121 		}
1122 		break;
1123 	case IEEE80211_FCTL_FROMDS:
1124 		/* DA BSSID SA */
1125 		memcpy(dst, hdr->addr1, ETH_ALEN);
1126 		memcpy(src, hdr->addr3, ETH_ALEN);
1127 
1128 		if (sdata->vif.type != IEEE80211_IF_TYPE_STA ||
1129 		    (is_multicast_ether_addr(dst) &&
1130 		     !compare_ether_addr(src, dev->dev_addr)))
1131 			return -1;
1132 		break;
1133 	case 0:
1134 		/* DA SA BSSID */
1135 		memcpy(dst, hdr->addr1, ETH_ALEN);
1136 		memcpy(src, hdr->addr2, ETH_ALEN);
1137 
1138 		if (sdata->vif.type != IEEE80211_IF_TYPE_IBSS) {
1139 			if (net_ratelimit()) {
1140 				printk(KERN_DEBUG "%s: dropped IBSS frame "
1141 				       "(DA=%s SA=%s BSSID=%s)\n",
1142 				       dev->name,
1143 				       print_mac(mac, hdr->addr1),
1144 				       print_mac(mac2, hdr->addr2),
1145 				       print_mac(mac3, hdr->addr3));
1146 			}
1147 			return -1;
1148 		}
1149 		break;
1150 	}
1151 
1152 	if (unlikely(skb->len - hdrlen < 8)) {
1153 		if (net_ratelimit()) {
1154 			printk(KERN_DEBUG "%s: RX too short data frame "
1155 			       "payload\n", dev->name);
1156 		}
1157 		return -1;
1158 	}
1159 
1160 	payload = skb->data + hdrlen;
1161 	ethertype = (payload[6] << 8) | payload[7];
1162 
1163 	if (likely((compare_ether_addr(payload, rfc1042_header) == 0 &&
1164 		    ethertype != ETH_P_AARP && ethertype != ETH_P_IPX) ||
1165 		   compare_ether_addr(payload, bridge_tunnel_header) == 0)) {
1166 		/* remove RFC1042 or Bridge-Tunnel encapsulation and
1167 		 * replace EtherType */
1168 		skb_pull(skb, hdrlen + 6);
1169 		memcpy(skb_push(skb, ETH_ALEN), src, ETH_ALEN);
1170 		memcpy(skb_push(skb, ETH_ALEN), dst, ETH_ALEN);
1171 	} else {
1172 		struct ethhdr *ehdr;
1173 		__be16 len;
1174 
1175 		skb_pull(skb, hdrlen);
1176 		len = htons(skb->len);
1177 		ehdr = (struct ethhdr *) skb_push(skb, sizeof(struct ethhdr));
1178 		memcpy(ehdr->h_dest, dst, ETH_ALEN);
1179 		memcpy(ehdr->h_source, src, ETH_ALEN);
1180 		ehdr->h_proto = len;
1181 	}
1182 	return 0;
1183 }
1184 
1185 /*
1186  * requires that rx->skb is a frame with ethernet header
1187  */
1188 static bool ieee80211_frame_allowed(struct ieee80211_txrx_data *rx)
1189 {
1190 	static const u8 pae_group_addr[ETH_ALEN]
1191 		= { 0x01, 0x80, 0xC2, 0x00, 0x00, 0x03 };
1192 	struct ethhdr *ehdr = (struct ethhdr *) rx->skb->data;
1193 
1194 	/*
1195 	 * Allow EAPOL frames to us/the PAE group address regardless
1196 	 * of whether the frame was encrypted or not.
1197 	 */
1198 	if (ehdr->h_proto == htons(ETH_P_PAE) &&
1199 	    (compare_ether_addr(ehdr->h_dest, rx->dev->dev_addr) == 0 ||
1200 	     compare_ether_addr(ehdr->h_dest, pae_group_addr) == 0))
1201 		return true;
1202 
1203 	if (ieee80211_802_1x_port_control(rx) ||
1204 	    ieee80211_drop_unencrypted(rx))
1205 		return false;
1206 
1207 	return true;
1208 }
1209 
1210 /*
1211  * requires that rx->skb is a frame with ethernet header
1212  */
1213 static void
1214 ieee80211_deliver_skb(struct ieee80211_txrx_data *rx)
1215 {
1216 	struct net_device *dev = rx->dev;
1217 	struct ieee80211_local *local = rx->local;
1218 	struct sk_buff *skb, *xmit_skb;
1219 	struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
1220 	struct ethhdr *ehdr = (struct ethhdr *) rx->skb->data;
1221 	struct sta_info *dsta;
1222 
1223 	skb = rx->skb;
1224 	xmit_skb = NULL;
1225 
1226 	if (local->bridge_packets && (sdata->vif.type == IEEE80211_IF_TYPE_AP ||
1227 				      sdata->vif.type == IEEE80211_IF_TYPE_VLAN) &&
1228 	    (rx->flags & IEEE80211_TXRXD_RXRA_MATCH)) {
1229 		if (is_multicast_ether_addr(ehdr->h_dest)) {
1230 			/*
1231 			 * send multicast frames both to higher layers in
1232 			 * local net stack and back to the wireless medium
1233 			 */
1234 			xmit_skb = skb_copy(skb, GFP_ATOMIC);
1235 			if (!xmit_skb && net_ratelimit())
1236 				printk(KERN_DEBUG "%s: failed to clone "
1237 				       "multicast frame\n", dev->name);
1238 		} else {
1239 			dsta = sta_info_get(local, skb->data);
1240 			if (dsta && dsta->dev == dev) {
1241 				/*
1242 				 * The destination station is associated to
1243 				 * this AP (in this VLAN), so send the frame
1244 				 * directly to it and do not pass it to local
1245 				 * net stack.
1246 				 */
1247 				xmit_skb = skb;
1248 				skb = NULL;
1249 			}
1250 			if (dsta)
1251 				sta_info_put(dsta);
1252 		}
1253 	}
1254 
1255 	if (skb) {
1256 		/* deliver to local stack */
1257 		skb->protocol = eth_type_trans(skb, dev);
1258 		memset(skb->cb, 0, sizeof(skb->cb));
1259 		netif_rx(skb);
1260 	}
1261 
1262 	if (xmit_skb) {
1263 		/* send to wireless media */
1264 		xmit_skb->protocol = htons(ETH_P_802_3);
1265 		skb_reset_network_header(xmit_skb);
1266 		skb_reset_mac_header(xmit_skb);
1267 		dev_queue_xmit(xmit_skb);
1268 	}
1269 }
1270 
1271 static ieee80211_txrx_result
1272 ieee80211_rx_h_amsdu(struct ieee80211_txrx_data *rx)
1273 {
1274 	struct net_device *dev = rx->dev;
1275 	struct ieee80211_local *local = rx->local;
1276 	u16 fc, ethertype;
1277 	u8 *payload;
1278 	struct sk_buff *skb = rx->skb, *frame = NULL;
1279 	const struct ethhdr *eth;
1280 	int remaining, err;
1281 	u8 dst[ETH_ALEN];
1282 	u8 src[ETH_ALEN];
1283 	DECLARE_MAC_BUF(mac);
1284 
1285 	fc = rx->fc;
1286 	if (unlikely((fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_DATA))
1287 		return TXRX_CONTINUE;
1288 
1289 	if (unlikely(!WLAN_FC_DATA_PRESENT(fc)))
1290 		return TXRX_DROP;
1291 
1292 	if (!(rx->flags & IEEE80211_TXRXD_RX_AMSDU))
1293 		return TXRX_CONTINUE;
1294 
1295 	err = ieee80211_data_to_8023(rx);
1296 	if (unlikely(err))
1297 		return TXRX_DROP;
1298 
1299 	skb->dev = dev;
1300 
1301 	dev->stats.rx_packets++;
1302 	dev->stats.rx_bytes += skb->len;
1303 
1304 	/* skip the wrapping header */
1305 	eth = (struct ethhdr *) skb_pull(skb, sizeof(struct ethhdr));
1306 	if (!eth)
1307 		return TXRX_DROP;
1308 
1309 	while (skb != frame) {
1310 		u8 padding;
1311 		__be16 len = eth->h_proto;
1312 		unsigned int subframe_len = sizeof(struct ethhdr) + ntohs(len);
1313 
1314 		remaining = skb->len;
1315 		memcpy(dst, eth->h_dest, ETH_ALEN);
1316 		memcpy(src, eth->h_source, ETH_ALEN);
1317 
1318 		padding = ((4 - subframe_len) & 0x3);
1319 		/* the last MSDU has no padding */
1320 		if (subframe_len > remaining) {
1321 			printk(KERN_DEBUG "%s: wrong buffer size", dev->name);
1322 			return TXRX_DROP;
1323 		}
1324 
1325 		skb_pull(skb, sizeof(struct ethhdr));
1326 		/* if last subframe reuse skb */
1327 		if (remaining <= subframe_len + padding)
1328 			frame = skb;
1329 		else {
1330 			frame = dev_alloc_skb(local->hw.extra_tx_headroom +
1331 					      subframe_len);
1332 
1333 			if (frame == NULL)
1334 				return TXRX_DROP;
1335 
1336 			skb_reserve(frame, local->hw.extra_tx_headroom +
1337 				    sizeof(struct ethhdr));
1338 			memcpy(skb_put(frame, ntohs(len)), skb->data,
1339 				ntohs(len));
1340 
1341 			eth = (struct ethhdr *) skb_pull(skb, ntohs(len) +
1342 							padding);
1343 			if (!eth) {
1344 				printk(KERN_DEBUG "%s: wrong buffer size ",
1345 				       dev->name);
1346 				dev_kfree_skb(frame);
1347 				return TXRX_DROP;
1348 			}
1349 		}
1350 
1351 		skb_reset_network_header(frame);
1352 		frame->dev = dev;
1353 		frame->priority = skb->priority;
1354 		rx->skb = frame;
1355 
1356 		payload = frame->data;
1357 		ethertype = (payload[6] << 8) | payload[7];
1358 
1359 		if (likely((compare_ether_addr(payload, rfc1042_header) == 0 &&
1360 			    ethertype != ETH_P_AARP && ethertype != ETH_P_IPX) ||
1361 			   compare_ether_addr(payload,
1362 					      bridge_tunnel_header) == 0)) {
1363 			/* remove RFC1042 or Bridge-Tunnel
1364 			 * encapsulation and replace EtherType */
1365 			skb_pull(frame, 6);
1366 			memcpy(skb_push(frame, ETH_ALEN), src, ETH_ALEN);
1367 			memcpy(skb_push(frame, ETH_ALEN), dst, ETH_ALEN);
1368 		} else {
1369 			memcpy(skb_push(frame, sizeof(__be16)),
1370 			       &len, sizeof(__be16));
1371 			memcpy(skb_push(frame, ETH_ALEN), src, ETH_ALEN);
1372 			memcpy(skb_push(frame, ETH_ALEN), dst, ETH_ALEN);
1373 		}
1374 
1375 		if (!ieee80211_frame_allowed(rx)) {
1376 			if (skb == frame) /* last frame */
1377 				return TXRX_DROP;
1378 			dev_kfree_skb(frame);
1379 			continue;
1380 		}
1381 
1382 		ieee80211_deliver_skb(rx);
1383 	}
1384 
1385 	return TXRX_QUEUED;
1386 }
1387 
1388 static ieee80211_txrx_result
1389 ieee80211_rx_h_data(struct ieee80211_txrx_data *rx)
1390 {
1391 	struct net_device *dev = rx->dev;
1392 	u16 fc;
1393 	int err;
1394 
1395 	fc = rx->fc;
1396 	if (unlikely((fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_DATA))
1397 		return TXRX_CONTINUE;
1398 
1399 	if (unlikely(!WLAN_FC_DATA_PRESENT(fc)))
1400 		return TXRX_DROP;
1401 
1402 	err = ieee80211_data_to_8023(rx);
1403 	if (unlikely(err))
1404 		return TXRX_DROP;
1405 
1406 	if (!ieee80211_frame_allowed(rx))
1407 		return TXRX_DROP;
1408 
1409 	rx->skb->dev = dev;
1410 
1411 	dev->stats.rx_packets++;
1412 	dev->stats.rx_bytes += rx->skb->len;
1413 
1414 	ieee80211_deliver_skb(rx);
1415 
1416 	return TXRX_QUEUED;
1417 }
1418 
1419 static ieee80211_txrx_result
1420 ieee80211_rx_h_ctrl(struct ieee80211_txrx_data *rx)
1421 {
1422 	struct ieee80211_local *local = rx->local;
1423 	struct ieee80211_hw *hw = &local->hw;
1424 	struct sk_buff *skb = rx->skb;
1425 	struct ieee80211_bar *bar = (struct ieee80211_bar *) skb->data;
1426 	struct tid_ampdu_rx *tid_agg_rx;
1427 	u16 start_seq_num;
1428 	u16 tid;
1429 
1430 	if (likely((rx->fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_CTL))
1431 		return TXRX_CONTINUE;
1432 
1433 	if ((rx->fc & IEEE80211_FCTL_STYPE) == IEEE80211_STYPE_BACK_REQ) {
1434 		if (!rx->sta)
1435 			return TXRX_CONTINUE;
1436 		tid = le16_to_cpu(bar->control) >> 12;
1437 		tid_agg_rx = &(rx->sta->ampdu_mlme.tid_rx[tid]);
1438 		if (tid_agg_rx->state != HT_AGG_STATE_OPERATIONAL)
1439 			return TXRX_CONTINUE;
1440 
1441 		start_seq_num = le16_to_cpu(bar->start_seq_num) >> 4;
1442 
1443 		/* reset session timer */
1444 		if (tid_agg_rx->timeout) {
1445 			unsigned long expires =
1446 				jiffies + (tid_agg_rx->timeout / 1000) * HZ;
1447 			mod_timer(&tid_agg_rx->session_timer, expires);
1448 		}
1449 
1450 		/* manage reordering buffer according to requested */
1451 		/* sequence number */
1452 		rcu_read_lock();
1453 		ieee80211_sta_manage_reorder_buf(hw, tid_agg_rx, NULL,
1454 						 start_seq_num, 1);
1455 		rcu_read_unlock();
1456 		return TXRX_DROP;
1457 	}
1458 
1459 	return TXRX_CONTINUE;
1460 }
1461 
1462 static ieee80211_txrx_result
1463 ieee80211_rx_h_mgmt(struct ieee80211_txrx_data *rx)
1464 {
1465 	struct ieee80211_sub_if_data *sdata;
1466 
1467 	if (!(rx->flags & IEEE80211_TXRXD_RXRA_MATCH))
1468 		return TXRX_DROP;
1469 
1470 	sdata = IEEE80211_DEV_TO_SUB_IF(rx->dev);
1471 	if ((sdata->vif.type == IEEE80211_IF_TYPE_STA ||
1472 	     sdata->vif.type == IEEE80211_IF_TYPE_IBSS) &&
1473 	    !(sdata->flags & IEEE80211_SDATA_USERSPACE_MLME))
1474 		ieee80211_sta_rx_mgmt(rx->dev, rx->skb, rx->u.rx.status);
1475 	else
1476 		return TXRX_DROP;
1477 
1478 	return TXRX_QUEUED;
1479 }
1480 
1481 static inline ieee80211_txrx_result __ieee80211_invoke_rx_handlers(
1482 				struct ieee80211_local *local,
1483 				ieee80211_rx_handler *handlers,
1484 				struct ieee80211_txrx_data *rx,
1485 				struct sta_info *sta)
1486 {
1487 	ieee80211_rx_handler *handler;
1488 	ieee80211_txrx_result res = TXRX_DROP;
1489 
1490 	for (handler = handlers; *handler != NULL; handler++) {
1491 		res = (*handler)(rx);
1492 
1493 		switch (res) {
1494 		case TXRX_CONTINUE:
1495 			continue;
1496 		case TXRX_DROP:
1497 			I802_DEBUG_INC(local->rx_handlers_drop);
1498 			if (sta)
1499 				sta->rx_dropped++;
1500 			break;
1501 		case TXRX_QUEUED:
1502 			I802_DEBUG_INC(local->rx_handlers_queued);
1503 			break;
1504 		}
1505 		break;
1506 	}
1507 
1508 	if (res == TXRX_DROP)
1509 		dev_kfree_skb(rx->skb);
1510 	return res;
1511 }
1512 
1513 static inline void ieee80211_invoke_rx_handlers(struct ieee80211_local *local,
1514 						ieee80211_rx_handler *handlers,
1515 						struct ieee80211_txrx_data *rx,
1516 						struct sta_info *sta)
1517 {
1518 	if (__ieee80211_invoke_rx_handlers(local, handlers, rx, sta) ==
1519 	    TXRX_CONTINUE)
1520 		dev_kfree_skb(rx->skb);
1521 }
1522 
1523 static void ieee80211_rx_michael_mic_report(struct net_device *dev,
1524 					    struct ieee80211_hdr *hdr,
1525 					    struct sta_info *sta,
1526 					    struct ieee80211_txrx_data *rx)
1527 {
1528 	int keyidx, hdrlen;
1529 	DECLARE_MAC_BUF(mac);
1530 	DECLARE_MAC_BUF(mac2);
1531 
1532 	hdrlen = ieee80211_get_hdrlen_from_skb(rx->skb);
1533 	if (rx->skb->len >= hdrlen + 4)
1534 		keyidx = rx->skb->data[hdrlen + 3] >> 6;
1535 	else
1536 		keyidx = -1;
1537 
1538 	if (net_ratelimit())
1539 		printk(KERN_DEBUG "%s: TKIP hwaccel reported Michael MIC "
1540 		       "failure from %s to %s keyidx=%d\n",
1541 		       dev->name, print_mac(mac, hdr->addr2),
1542 		       print_mac(mac2, hdr->addr1), keyidx);
1543 
1544 	if (!sta) {
1545 		/*
1546 		 * Some hardware seem to generate incorrect Michael MIC
1547 		 * reports; ignore them to avoid triggering countermeasures.
1548 		 */
1549 		if (net_ratelimit())
1550 			printk(KERN_DEBUG "%s: ignored spurious Michael MIC "
1551 			       "error for unknown address %s\n",
1552 			       dev->name, print_mac(mac, hdr->addr2));
1553 		goto ignore;
1554 	}
1555 
1556 	if (!(rx->fc & IEEE80211_FCTL_PROTECTED)) {
1557 		if (net_ratelimit())
1558 			printk(KERN_DEBUG "%s: ignored spurious Michael MIC "
1559 			       "error for a frame with no PROTECTED flag (src "
1560 			       "%s)\n", dev->name, print_mac(mac, hdr->addr2));
1561 		goto ignore;
1562 	}
1563 
1564 	if (rx->sdata->vif.type == IEEE80211_IF_TYPE_AP && keyidx) {
1565 		/*
1566 		 * APs with pairwise keys should never receive Michael MIC
1567 		 * errors for non-zero keyidx because these are reserved for
1568 		 * group keys and only the AP is sending real multicast
1569 		 * frames in the BSS.
1570 		 */
1571 		if (net_ratelimit())
1572 			printk(KERN_DEBUG "%s: ignored Michael MIC error for "
1573 			       "a frame with non-zero keyidx (%d)"
1574 			       " (src %s)\n", dev->name, keyidx,
1575 			       print_mac(mac, hdr->addr2));
1576 		goto ignore;
1577 	}
1578 
1579 	if ((rx->fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_DATA &&
1580 	    ((rx->fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_MGMT ||
1581 	     (rx->fc & IEEE80211_FCTL_STYPE) != IEEE80211_STYPE_AUTH)) {
1582 		if (net_ratelimit())
1583 			printk(KERN_DEBUG "%s: ignored spurious Michael MIC "
1584 			       "error for a frame that cannot be encrypted "
1585 			       "(fc=0x%04x) (src %s)\n",
1586 			       dev->name, rx->fc, print_mac(mac, hdr->addr2));
1587 		goto ignore;
1588 	}
1589 
1590 	mac80211_ev_michael_mic_failure(rx->dev, keyidx, hdr);
1591  ignore:
1592 	dev_kfree_skb(rx->skb);
1593 	rx->skb = NULL;
1594 }
1595 
1596 ieee80211_rx_handler ieee80211_rx_handlers[] =
1597 {
1598 	ieee80211_rx_h_if_stats,
1599 	ieee80211_rx_h_passive_scan,
1600 	ieee80211_rx_h_check,
1601 	ieee80211_rx_h_decrypt,
1602 	ieee80211_rx_h_sta_process,
1603 	ieee80211_rx_h_defragment,
1604 	ieee80211_rx_h_ps_poll,
1605 	ieee80211_rx_h_michael_mic_verify,
1606 	/* this must be after decryption - so header is counted in MPDU mic
1607 	 * must be before pae and data, so QOS_DATA format frames
1608 	 * are not passed to user space by these functions
1609 	 */
1610 	ieee80211_rx_h_remove_qos_control,
1611 	ieee80211_rx_h_amsdu,
1612 	ieee80211_rx_h_data,
1613 	ieee80211_rx_h_ctrl,
1614 	ieee80211_rx_h_mgmt,
1615 	NULL
1616 };
1617 
1618 /* main receive path */
1619 
1620 static int prepare_for_handlers(struct ieee80211_sub_if_data *sdata,
1621 				u8 *bssid, struct ieee80211_txrx_data *rx,
1622 				struct ieee80211_hdr *hdr)
1623 {
1624 	int multicast = is_multicast_ether_addr(hdr->addr1);
1625 
1626 	switch (sdata->vif.type) {
1627 	case IEEE80211_IF_TYPE_STA:
1628 		if (!bssid)
1629 			return 0;
1630 		if (!ieee80211_bssid_match(bssid, sdata->u.sta.bssid)) {
1631 			if (!(rx->flags & IEEE80211_TXRXD_RXIN_SCAN))
1632 				return 0;
1633 			rx->flags &= ~IEEE80211_TXRXD_RXRA_MATCH;
1634 		} else if (!multicast &&
1635 			   compare_ether_addr(sdata->dev->dev_addr,
1636 					      hdr->addr1) != 0) {
1637 			if (!(sdata->dev->flags & IFF_PROMISC))
1638 				return 0;
1639 			rx->flags &= ~IEEE80211_TXRXD_RXRA_MATCH;
1640 		}
1641 		break;
1642 	case IEEE80211_IF_TYPE_IBSS:
1643 		if (!bssid)
1644 			return 0;
1645 		if (!ieee80211_bssid_match(bssid, sdata->u.sta.bssid)) {
1646 			if (!(rx->flags & IEEE80211_TXRXD_RXIN_SCAN))
1647 				return 0;
1648 			rx->flags &= ~IEEE80211_TXRXD_RXRA_MATCH;
1649 		} else if (!multicast &&
1650 			   compare_ether_addr(sdata->dev->dev_addr,
1651 					      hdr->addr1) != 0) {
1652 			if (!(sdata->dev->flags & IFF_PROMISC))
1653 				return 0;
1654 			rx->flags &= ~IEEE80211_TXRXD_RXRA_MATCH;
1655 		} else if (!rx->sta)
1656 			rx->sta = ieee80211_ibss_add_sta(sdata->dev, rx->skb,
1657 							 bssid, hdr->addr2);
1658 		break;
1659 	case IEEE80211_IF_TYPE_VLAN:
1660 	case IEEE80211_IF_TYPE_AP:
1661 		if (!bssid) {
1662 			if (compare_ether_addr(sdata->dev->dev_addr,
1663 					       hdr->addr1))
1664 				return 0;
1665 		} else if (!ieee80211_bssid_match(bssid,
1666 					sdata->dev->dev_addr)) {
1667 			if (!(rx->flags & IEEE80211_TXRXD_RXIN_SCAN))
1668 				return 0;
1669 			rx->flags &= ~IEEE80211_TXRXD_RXRA_MATCH;
1670 		}
1671 		if (sdata->dev == sdata->local->mdev &&
1672 		    !(rx->flags & IEEE80211_TXRXD_RXIN_SCAN))
1673 			/* do not receive anything via
1674 			 * master device when not scanning */
1675 			return 0;
1676 		break;
1677 	case IEEE80211_IF_TYPE_WDS:
1678 		if (bssid ||
1679 		    (rx->fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_DATA)
1680 			return 0;
1681 		if (compare_ether_addr(sdata->u.wds.remote_addr, hdr->addr2))
1682 			return 0;
1683 		break;
1684 	case IEEE80211_IF_TYPE_MNTR:
1685 		/* take everything */
1686 		break;
1687 	case IEEE80211_IF_TYPE_INVALID:
1688 		/* should never get here */
1689 		WARN_ON(1);
1690 		break;
1691 	}
1692 
1693 	return 1;
1694 }
1695 
1696 /*
1697  * This is the actual Rx frames handler. as it blongs to Rx path it must
1698  * be called with rcu_read_lock protection.
1699  */
1700 static void __ieee80211_rx_handle_packet(struct ieee80211_hw *hw,
1701 					 struct sk_buff *skb,
1702 					 struct ieee80211_rx_status *status,
1703 					 u32 load)
1704 {
1705 	struct ieee80211_local *local = hw_to_local(hw);
1706 	struct ieee80211_sub_if_data *sdata;
1707 	struct sta_info *sta;
1708 	struct ieee80211_hdr *hdr;
1709 	struct ieee80211_txrx_data rx;
1710 	u16 type;
1711 	int prepares;
1712 	struct ieee80211_sub_if_data *prev = NULL;
1713 	struct sk_buff *skb_new;
1714 	u8 *bssid;
1715 
1716 	hdr = (struct ieee80211_hdr *) skb->data;
1717 	memset(&rx, 0, sizeof(rx));
1718 	rx.skb = skb;
1719 	rx.local = local;
1720 
1721 	rx.u.rx.status = status;
1722 	rx.u.rx.load = load;
1723 	rx.fc = le16_to_cpu(hdr->frame_control);
1724 	type = rx.fc & IEEE80211_FCTL_FTYPE;
1725 
1726 	if (type == IEEE80211_FTYPE_DATA || type == IEEE80211_FTYPE_MGMT)
1727 		local->dot11ReceivedFragmentCount++;
1728 
1729 	sta = rx.sta = sta_info_get(local, hdr->addr2);
1730 	if (sta) {
1731 		rx.dev = rx.sta->dev;
1732 		rx.sdata = IEEE80211_DEV_TO_SUB_IF(rx.dev);
1733 	}
1734 
1735 	if ((status->flag & RX_FLAG_MMIC_ERROR)) {
1736 		ieee80211_rx_michael_mic_report(local->mdev, hdr, sta, &rx);
1737 		goto end;
1738 	}
1739 
1740 	if (unlikely(local->sta_sw_scanning || local->sta_hw_scanning))
1741 		rx.flags |= IEEE80211_TXRXD_RXIN_SCAN;
1742 
1743 	if (__ieee80211_invoke_rx_handlers(local, local->rx_pre_handlers, &rx,
1744 					   sta) != TXRX_CONTINUE)
1745 		goto end;
1746 	skb = rx.skb;
1747 
1748 	if (sta && !(sta->flags & (WLAN_STA_WDS | WLAN_STA_ASSOC_AP)) &&
1749 	    !atomic_read(&local->iff_promiscs) &&
1750 	    !is_multicast_ether_addr(hdr->addr1)) {
1751 		rx.flags |= IEEE80211_TXRXD_RXRA_MATCH;
1752 		ieee80211_invoke_rx_handlers(local, local->rx_handlers, &rx,
1753 					     rx.sta);
1754 		sta_info_put(sta);
1755 		return;
1756 	}
1757 
1758 	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
1759 		if (!netif_running(sdata->dev))
1760 			continue;
1761 
1762 		if (sdata->vif.type == IEEE80211_IF_TYPE_MNTR)
1763 			continue;
1764 
1765 		bssid = ieee80211_get_bssid(hdr, skb->len, sdata->vif.type);
1766 		rx.flags |= IEEE80211_TXRXD_RXRA_MATCH;
1767 		prepares = prepare_for_handlers(sdata, bssid, &rx, hdr);
1768 		/* prepare_for_handlers can change sta */
1769 		sta = rx.sta;
1770 
1771 		if (!prepares)
1772 			continue;
1773 
1774 		/*
1775 		 * frame is destined for this interface, but if it's not
1776 		 * also for the previous one we handle that after the
1777 		 * loop to avoid copying the SKB once too much
1778 		 */
1779 
1780 		if (!prev) {
1781 			prev = sdata;
1782 			continue;
1783 		}
1784 
1785 		/*
1786 		 * frame was destined for the previous interface
1787 		 * so invoke RX handlers for it
1788 		 */
1789 
1790 		skb_new = skb_copy(skb, GFP_ATOMIC);
1791 		if (!skb_new) {
1792 			if (net_ratelimit())
1793 				printk(KERN_DEBUG "%s: failed to copy "
1794 				       "multicast frame for %s",
1795 				       wiphy_name(local->hw.wiphy),
1796 				       prev->dev->name);
1797 			continue;
1798 		}
1799 		rx.fc = le16_to_cpu(hdr->frame_control);
1800 		rx.skb = skb_new;
1801 		rx.dev = prev->dev;
1802 		rx.sdata = prev;
1803 		ieee80211_invoke_rx_handlers(local, local->rx_handlers,
1804 					     &rx, sta);
1805 		prev = sdata;
1806 	}
1807 	if (prev) {
1808 		rx.fc = le16_to_cpu(hdr->frame_control);
1809 		rx.skb = skb;
1810 		rx.dev = prev->dev;
1811 		rx.sdata = prev;
1812 		ieee80211_invoke_rx_handlers(local, local->rx_handlers,
1813 					     &rx, sta);
1814 	} else
1815 		dev_kfree_skb(skb);
1816 
1817  end:
1818 	if (sta)
1819 		sta_info_put(sta);
1820 }
1821 
1822 #define SEQ_MODULO 0x1000
1823 #define SEQ_MASK   0xfff
1824 
1825 static inline int seq_less(u16 sq1, u16 sq2)
1826 {
1827 	return (((sq1 - sq2) & SEQ_MASK) > (SEQ_MODULO >> 1));
1828 }
1829 
1830 static inline u16 seq_inc(u16 sq)
1831 {
1832 	return ((sq + 1) & SEQ_MASK);
1833 }
1834 
1835 static inline u16 seq_sub(u16 sq1, u16 sq2)
1836 {
1837 	return ((sq1 - sq2) & SEQ_MASK);
1838 }
1839 
1840 
1841 /*
1842  * As it function blongs to Rx path it must be called with
1843  * the proper rcu_read_lock protection for its flow.
1844  */
1845 u8 ieee80211_sta_manage_reorder_buf(struct ieee80211_hw *hw,
1846 				struct tid_ampdu_rx *tid_agg_rx,
1847 				struct sk_buff *skb, u16 mpdu_seq_num,
1848 				int bar_req)
1849 {
1850 	struct ieee80211_local *local = hw_to_local(hw);
1851 	struct ieee80211_rx_status status;
1852 	u16 head_seq_num, buf_size;
1853 	int index;
1854 	u32 pkt_load;
1855 
1856 	buf_size = tid_agg_rx->buf_size;
1857 	head_seq_num = tid_agg_rx->head_seq_num;
1858 
1859 	/* frame with out of date sequence number */
1860 	if (seq_less(mpdu_seq_num, head_seq_num)) {
1861 		dev_kfree_skb(skb);
1862 		return 1;
1863 	}
1864 
1865 	/* if frame sequence number exceeds our buffering window size or
1866 	 * block Ack Request arrived - release stored frames */
1867 	if ((!seq_less(mpdu_seq_num, head_seq_num + buf_size)) || (bar_req)) {
1868 		/* new head to the ordering buffer */
1869 		if (bar_req)
1870 			head_seq_num = mpdu_seq_num;
1871 		else
1872 			head_seq_num =
1873 				seq_inc(seq_sub(mpdu_seq_num, buf_size));
1874 		/* release stored frames up to new head to stack */
1875 		while (seq_less(tid_agg_rx->head_seq_num, head_seq_num)) {
1876 			index = seq_sub(tid_agg_rx->head_seq_num,
1877 				tid_agg_rx->ssn)
1878 				% tid_agg_rx->buf_size;
1879 
1880 			if (tid_agg_rx->reorder_buf[index]) {
1881 				/* release the reordered frames to stack */
1882 				memcpy(&status,
1883 					tid_agg_rx->reorder_buf[index]->cb,
1884 					sizeof(status));
1885 				pkt_load = ieee80211_rx_load_stats(local,
1886 						tid_agg_rx->reorder_buf[index],
1887 						&status);
1888 				__ieee80211_rx_handle_packet(hw,
1889 					tid_agg_rx->reorder_buf[index],
1890 					&status, pkt_load);
1891 				tid_agg_rx->stored_mpdu_num--;
1892 				tid_agg_rx->reorder_buf[index] = NULL;
1893 			}
1894 			tid_agg_rx->head_seq_num =
1895 				seq_inc(tid_agg_rx->head_seq_num);
1896 		}
1897 		if (bar_req)
1898 			return 1;
1899 	}
1900 
1901 	/* now the new frame is always in the range of the reordering */
1902 	/* buffer window */
1903 	index = seq_sub(mpdu_seq_num, tid_agg_rx->ssn)
1904 				% tid_agg_rx->buf_size;
1905 	/* check if we already stored this frame */
1906 	if (tid_agg_rx->reorder_buf[index]) {
1907 		dev_kfree_skb(skb);
1908 		return 1;
1909 	}
1910 
1911 	/* if arrived mpdu is in the right order and nothing else stored */
1912 	/* release it immediately */
1913 	if (mpdu_seq_num == tid_agg_rx->head_seq_num &&
1914 			tid_agg_rx->stored_mpdu_num == 0) {
1915 		tid_agg_rx->head_seq_num =
1916 			seq_inc(tid_agg_rx->head_seq_num);
1917 		return 0;
1918 	}
1919 
1920 	/* put the frame in the reordering buffer */
1921 	tid_agg_rx->reorder_buf[index] = skb;
1922 	tid_agg_rx->stored_mpdu_num++;
1923 	/* release the buffer until next missing frame */
1924 	index = seq_sub(tid_agg_rx->head_seq_num, tid_agg_rx->ssn)
1925 						% tid_agg_rx->buf_size;
1926 	while (tid_agg_rx->reorder_buf[index]) {
1927 		/* release the reordered frame back to stack */
1928 		memcpy(&status, tid_agg_rx->reorder_buf[index]->cb,
1929 			sizeof(status));
1930 		pkt_load = ieee80211_rx_load_stats(local,
1931 					tid_agg_rx->reorder_buf[index],
1932 					&status);
1933 		__ieee80211_rx_handle_packet(hw, tid_agg_rx->reorder_buf[index],
1934 						&status, pkt_load);
1935 		tid_agg_rx->stored_mpdu_num--;
1936 		tid_agg_rx->reorder_buf[index] = NULL;
1937 		tid_agg_rx->head_seq_num = seq_inc(tid_agg_rx->head_seq_num);
1938 		index =	seq_sub(tid_agg_rx->head_seq_num,
1939 			tid_agg_rx->ssn) % tid_agg_rx->buf_size;
1940 	}
1941 	return 1;
1942 }
1943 
1944 static u8 ieee80211_rx_reorder_ampdu(struct ieee80211_local *local,
1945 				     struct sk_buff *skb)
1946 {
1947 	struct ieee80211_hw *hw = &local->hw;
1948 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
1949 	struct sta_info *sta;
1950 	struct tid_ampdu_rx *tid_agg_rx;
1951 	u16 fc, sc;
1952 	u16 mpdu_seq_num;
1953 	u8 ret = 0, *qc;
1954 	int tid;
1955 
1956 	sta = sta_info_get(local, hdr->addr2);
1957 	if (!sta)
1958 		return ret;
1959 
1960 	fc = le16_to_cpu(hdr->frame_control);
1961 
1962 	/* filter the QoS data rx stream according to
1963 	 * STA/TID and check if this STA/TID is on aggregation */
1964 	if (!WLAN_FC_IS_QOS_DATA(fc))
1965 		goto end_reorder;
1966 
1967 	qc = skb->data + ieee80211_get_hdrlen(fc) - QOS_CONTROL_LEN;
1968 	tid = qc[0] & QOS_CONTROL_TID_MASK;
1969 	tid_agg_rx = &(sta->ampdu_mlme.tid_rx[tid]);
1970 
1971 	if (tid_agg_rx->state != HT_AGG_STATE_OPERATIONAL)
1972 		goto end_reorder;
1973 
1974 	/* null data frames are excluded */
1975 	if (unlikely(fc & IEEE80211_STYPE_NULLFUNC))
1976 		goto end_reorder;
1977 
1978 	/* new un-ordered ampdu frame - process it */
1979 
1980 	/* reset session timer */
1981 	if (tid_agg_rx->timeout) {
1982 		unsigned long expires =
1983 			jiffies + (tid_agg_rx->timeout / 1000) * HZ;
1984 		mod_timer(&tid_agg_rx->session_timer, expires);
1985 	}
1986 
1987 	/* if this mpdu is fragmented - terminate rx aggregation session */
1988 	sc = le16_to_cpu(hdr->seq_ctrl);
1989 	if (sc & IEEE80211_SCTL_FRAG) {
1990 		ieee80211_sta_stop_rx_ba_session(sta->dev, sta->addr,
1991 			tid, 0, WLAN_REASON_QSTA_REQUIRE_SETUP);
1992 		ret = 1;
1993 		goto end_reorder;
1994 	}
1995 
1996 	/* according to mpdu sequence number deal with reordering buffer */
1997 	mpdu_seq_num = (sc & IEEE80211_SCTL_SEQ) >> 4;
1998 	ret = ieee80211_sta_manage_reorder_buf(hw, tid_agg_rx, skb,
1999 						mpdu_seq_num, 0);
2000 end_reorder:
2001 	if (sta)
2002 		sta_info_put(sta);
2003 	return ret;
2004 }
2005 
2006 /*
2007  * This is the receive path handler. It is called by a low level driver when an
2008  * 802.11 MPDU is received from the hardware.
2009  */
2010 void __ieee80211_rx(struct ieee80211_hw *hw, struct sk_buff *skb,
2011 		    struct ieee80211_rx_status *status)
2012 {
2013 	struct ieee80211_local *local = hw_to_local(hw);
2014 	u32 pkt_load;
2015 
2016 	/*
2017 	 * key references and virtual interfaces are protected using RCU
2018 	 * and this requires that we are in a read-side RCU section during
2019 	 * receive processing
2020 	 */
2021 	rcu_read_lock();
2022 
2023 	/*
2024 	 * Frames with failed FCS/PLCP checksum are not returned,
2025 	 * all other frames are returned without radiotap header
2026 	 * if it was previously present.
2027 	 * Also, frames with less than 16 bytes are dropped.
2028 	 */
2029 	skb = ieee80211_rx_monitor(local, skb, status);
2030 	if (!skb) {
2031 		rcu_read_unlock();
2032 		return;
2033 	}
2034 
2035 	pkt_load = ieee80211_rx_load_stats(local, skb, status);
2036 	local->channel_use_raw += pkt_load;
2037 
2038 	if (!ieee80211_rx_reorder_ampdu(local, skb))
2039 		__ieee80211_rx_handle_packet(hw, skb, status, pkt_load);
2040 
2041 	rcu_read_unlock();
2042 }
2043 EXPORT_SYMBOL(__ieee80211_rx);
2044 
2045 /* This is a version of the rx handler that can be called from hard irq
2046  * context. Post the skb on the queue and schedule the tasklet */
2047 void ieee80211_rx_irqsafe(struct ieee80211_hw *hw, struct sk_buff *skb,
2048 			  struct ieee80211_rx_status *status)
2049 {
2050 	struct ieee80211_local *local = hw_to_local(hw);
2051 
2052 	BUILD_BUG_ON(sizeof(struct ieee80211_rx_status) > sizeof(skb->cb));
2053 
2054 	skb->dev = local->mdev;
2055 	/* copy status into skb->cb for use by tasklet */
2056 	memcpy(skb->cb, status, sizeof(*status));
2057 	skb->pkt_type = IEEE80211_RX_MSG;
2058 	skb_queue_tail(&local->skb_queue, skb);
2059 	tasklet_schedule(&local->tasklet);
2060 }
2061 EXPORT_SYMBOL(ieee80211_rx_irqsafe);
2062