xref: /linux/net/mac80211/rx.c (revision 8fa5723aa7e053d498336b48448b292fc2e0458b)
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/jiffies.h>
13 #include <linux/kernel.h>
14 #include <linux/skbuff.h>
15 #include <linux/netdevice.h>
16 #include <linux/etherdevice.h>
17 #include <linux/rcupdate.h>
18 #include <net/mac80211.h>
19 #include <net/ieee80211_radiotap.h>
20 
21 #include "ieee80211_i.h"
22 #include "led.h"
23 #include "mesh.h"
24 #include "wep.h"
25 #include "wpa.h"
26 #include "tkip.h"
27 #include "wme.h"
28 
29 u8 ieee80211_sta_manage_reorder_buf(struct ieee80211_hw *hw,
30 				struct tid_ampdu_rx *tid_agg_rx,
31 				struct sk_buff *skb, u16 mpdu_seq_num,
32 				int bar_req);
33 /*
34  * monitor mode reception
35  *
36  * This function cleans up the SKB, i.e. it removes all the stuff
37  * only useful for monitoring.
38  */
39 static struct sk_buff *remove_monitor_info(struct ieee80211_local *local,
40 					   struct sk_buff *skb,
41 					   int rtap_len)
42 {
43 	skb_pull(skb, rtap_len);
44 
45 	if (local->hw.flags & IEEE80211_HW_RX_INCLUDES_FCS) {
46 		if (likely(skb->len > FCS_LEN))
47 			skb_trim(skb, skb->len - FCS_LEN);
48 		else {
49 			/* driver bug */
50 			WARN_ON(1);
51 			dev_kfree_skb(skb);
52 			skb = NULL;
53 		}
54 	}
55 
56 	return skb;
57 }
58 
59 static inline int should_drop_frame(struct ieee80211_rx_status *status,
60 				    struct sk_buff *skb,
61 				    int present_fcs_len,
62 				    int radiotap_len)
63 {
64 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
65 
66 	if (status->flag & (RX_FLAG_FAILED_FCS_CRC | RX_FLAG_FAILED_PLCP_CRC))
67 		return 1;
68 	if (unlikely(skb->len < 16 + present_fcs_len + radiotap_len))
69 		return 1;
70 	if (ieee80211_is_ctl(hdr->frame_control) &&
71 	    !ieee80211_is_pspoll(hdr->frame_control) &&
72 	    !ieee80211_is_back_req(hdr->frame_control))
73 		return 1;
74 	return 0;
75 }
76 
77 static int
78 ieee80211_rx_radiotap_len(struct ieee80211_local *local,
79 			  struct ieee80211_rx_status *status)
80 {
81 	int len;
82 
83 	/* always present fields */
84 	len = sizeof(struct ieee80211_radiotap_header) + 9;
85 
86 	if (status->flag & RX_FLAG_TSFT)
87 		len += 8;
88 	if (local->hw.flags & IEEE80211_HW_SIGNAL_DB ||
89 	    local->hw.flags & IEEE80211_HW_SIGNAL_DBM)
90 		len += 1;
91 	if (local->hw.flags & IEEE80211_HW_NOISE_DBM)
92 		len += 1;
93 
94 	if (len & 1) /* padding for RX_FLAGS if necessary */
95 		len++;
96 
97 	/* make sure radiotap starts at a naturally aligned address */
98 	if (len % 8)
99 		len = roundup(len, 8);
100 
101 	return len;
102 }
103 
104 /**
105  * ieee80211_add_rx_radiotap_header - add radiotap header
106  *
107  * add a radiotap header containing all the fields which the hardware provided.
108  */
109 static void
110 ieee80211_add_rx_radiotap_header(struct ieee80211_local *local,
111 				 struct sk_buff *skb,
112 				 struct ieee80211_rx_status *status,
113 				 struct ieee80211_rate *rate,
114 				 int rtap_len)
115 {
116 	struct ieee80211_radiotap_header *rthdr;
117 	unsigned char *pos;
118 
119 	rthdr = (struct ieee80211_radiotap_header *)skb_push(skb, rtap_len);
120 	memset(rthdr, 0, rtap_len);
121 
122 	/* radiotap header, set always present flags */
123 	rthdr->it_present =
124 		cpu_to_le32((1 << IEEE80211_RADIOTAP_FLAGS) |
125 			    (1 << IEEE80211_RADIOTAP_RATE) |
126 			    (1 << IEEE80211_RADIOTAP_CHANNEL) |
127 			    (1 << IEEE80211_RADIOTAP_ANTENNA) |
128 			    (1 << IEEE80211_RADIOTAP_RX_FLAGS));
129 	rthdr->it_len = cpu_to_le16(rtap_len);
130 
131 	pos = (unsigned char *)(rthdr+1);
132 
133 	/* the order of the following fields is important */
134 
135 	/* IEEE80211_RADIOTAP_TSFT */
136 	if (status->flag & RX_FLAG_TSFT) {
137 		*(__le64 *)pos = cpu_to_le64(status->mactime);
138 		rthdr->it_present |=
139 			cpu_to_le32(1 << IEEE80211_RADIOTAP_TSFT);
140 		pos += 8;
141 	}
142 
143 	/* IEEE80211_RADIOTAP_FLAGS */
144 	if (local->hw.flags & IEEE80211_HW_RX_INCLUDES_FCS)
145 		*pos |= IEEE80211_RADIOTAP_F_FCS;
146 	if (status->flag & RX_FLAG_SHORTPRE)
147 		*pos |= IEEE80211_RADIOTAP_F_SHORTPRE;
148 	pos++;
149 
150 	/* IEEE80211_RADIOTAP_RATE */
151 	*pos = rate->bitrate / 5;
152 	pos++;
153 
154 	/* IEEE80211_RADIOTAP_CHANNEL */
155 	*(__le16 *)pos = cpu_to_le16(status->freq);
156 	pos += 2;
157 	if (status->band == IEEE80211_BAND_5GHZ)
158 		*(__le16 *)pos = cpu_to_le16(IEEE80211_CHAN_OFDM |
159 					     IEEE80211_CHAN_5GHZ);
160 	else if (rate->flags & IEEE80211_RATE_ERP_G)
161 		*(__le16 *)pos = cpu_to_le16(IEEE80211_CHAN_OFDM |
162 					     IEEE80211_CHAN_2GHZ);
163 	else
164 		*(__le16 *)pos = cpu_to_le16(IEEE80211_CHAN_CCK |
165 					     IEEE80211_CHAN_2GHZ);
166 	pos += 2;
167 
168 	/* IEEE80211_RADIOTAP_DBM_ANTSIGNAL */
169 	if (local->hw.flags & IEEE80211_HW_SIGNAL_DBM) {
170 		*pos = status->signal;
171 		rthdr->it_present |=
172 			cpu_to_le32(1 << IEEE80211_RADIOTAP_DBM_ANTSIGNAL);
173 		pos++;
174 	}
175 
176 	/* IEEE80211_RADIOTAP_DBM_ANTNOISE */
177 	if (local->hw.flags & IEEE80211_HW_NOISE_DBM) {
178 		*pos = status->noise;
179 		rthdr->it_present |=
180 			cpu_to_le32(1 << IEEE80211_RADIOTAP_DBM_ANTNOISE);
181 		pos++;
182 	}
183 
184 	/* IEEE80211_RADIOTAP_LOCK_QUALITY is missing */
185 
186 	/* IEEE80211_RADIOTAP_ANTENNA */
187 	*pos = status->antenna;
188 	pos++;
189 
190 	/* IEEE80211_RADIOTAP_DB_ANTSIGNAL */
191 	if (local->hw.flags & IEEE80211_HW_SIGNAL_DB) {
192 		*pos = status->signal;
193 		rthdr->it_present |=
194 			cpu_to_le32(1 << IEEE80211_RADIOTAP_DB_ANTSIGNAL);
195 		pos++;
196 	}
197 
198 	/* IEEE80211_RADIOTAP_DB_ANTNOISE is not used */
199 
200 	/* IEEE80211_RADIOTAP_RX_FLAGS */
201 	/* ensure 2 byte alignment for the 2 byte field as required */
202 	if ((pos - (unsigned char *)rthdr) & 1)
203 		pos++;
204 	/* FIXME: when radiotap gets a 'bad PLCP' flag use it here */
205 	if (status->flag & (RX_FLAG_FAILED_FCS_CRC | RX_FLAG_FAILED_PLCP_CRC))
206 		*(__le16 *)pos |= cpu_to_le16(IEEE80211_RADIOTAP_F_RX_BADFCS);
207 	pos += 2;
208 }
209 
210 /*
211  * This function copies a received frame to all monitor interfaces and
212  * returns a cleaned-up SKB that no longer includes the FCS nor the
213  * radiotap header the driver might have added.
214  */
215 static struct sk_buff *
216 ieee80211_rx_monitor(struct ieee80211_local *local, struct sk_buff *origskb,
217 		     struct ieee80211_rx_status *status,
218 		     struct ieee80211_rate *rate)
219 {
220 	struct ieee80211_sub_if_data *sdata;
221 	int needed_headroom = 0;
222 	struct sk_buff *skb, *skb2;
223 	struct net_device *prev_dev = NULL;
224 	int present_fcs_len = 0;
225 	int rtap_len = 0;
226 
227 	/*
228 	 * First, we may need to make a copy of the skb because
229 	 *  (1) we need to modify it for radiotap (if not present), and
230 	 *  (2) the other RX handlers will modify the skb we got.
231 	 *
232 	 * We don't need to, of course, if we aren't going to return
233 	 * the SKB because it has a bad FCS/PLCP checksum.
234 	 */
235 	if (status->flag & RX_FLAG_RADIOTAP)
236 		rtap_len = ieee80211_get_radiotap_len(origskb->data);
237 	else
238 		/* room for the radiotap header based on driver features */
239 		needed_headroom = ieee80211_rx_radiotap_len(local, status);
240 
241 	if (local->hw.flags & IEEE80211_HW_RX_INCLUDES_FCS)
242 		present_fcs_len = FCS_LEN;
243 
244 	if (!local->monitors) {
245 		if (should_drop_frame(status, origskb, present_fcs_len,
246 				      rtap_len)) {
247 			dev_kfree_skb(origskb);
248 			return NULL;
249 		}
250 
251 		return remove_monitor_info(local, origskb, rtap_len);
252 	}
253 
254 	if (should_drop_frame(status, origskb, present_fcs_len, rtap_len)) {
255 		/* only need to expand headroom if necessary */
256 		skb = origskb;
257 		origskb = NULL;
258 
259 		/*
260 		 * This shouldn't trigger often because most devices have an
261 		 * RX header they pull before we get here, and that should
262 		 * be big enough for our radiotap information. We should
263 		 * probably export the length to drivers so that we can have
264 		 * them allocate enough headroom to start with.
265 		 */
266 		if (skb_headroom(skb) < needed_headroom &&
267 		    pskb_expand_head(skb, needed_headroom, 0, GFP_ATOMIC)) {
268 			dev_kfree_skb(skb);
269 			return NULL;
270 		}
271 	} else {
272 		/*
273 		 * Need to make a copy and possibly remove radiotap header
274 		 * and FCS from the original.
275 		 */
276 		skb = skb_copy_expand(origskb, needed_headroom, 0, GFP_ATOMIC);
277 
278 		origskb = remove_monitor_info(local, origskb, rtap_len);
279 
280 		if (!skb)
281 			return origskb;
282 	}
283 
284 	/* if necessary, prepend radiotap information */
285 	if (!(status->flag & RX_FLAG_RADIOTAP))
286 		ieee80211_add_rx_radiotap_header(local, skb, status, rate,
287 						 needed_headroom);
288 
289 	skb_reset_mac_header(skb);
290 	skb->ip_summed = CHECKSUM_UNNECESSARY;
291 	skb->pkt_type = PACKET_OTHERHOST;
292 	skb->protocol = htons(ETH_P_802_2);
293 
294 	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
295 		if (!netif_running(sdata->dev))
296 			continue;
297 
298 		if (sdata->vif.type != NL80211_IFTYPE_MONITOR)
299 			continue;
300 
301 		if (sdata->u.mntr_flags & MONITOR_FLAG_COOK_FRAMES)
302 			continue;
303 
304 		if (prev_dev) {
305 			skb2 = skb_clone(skb, GFP_ATOMIC);
306 			if (skb2) {
307 				skb2->dev = prev_dev;
308 				netif_rx(skb2);
309 			}
310 		}
311 
312 		prev_dev = sdata->dev;
313 		sdata->dev->stats.rx_packets++;
314 		sdata->dev->stats.rx_bytes += skb->len;
315 	}
316 
317 	if (prev_dev) {
318 		skb->dev = prev_dev;
319 		netif_rx(skb);
320 	} else
321 		dev_kfree_skb(skb);
322 
323 	return origskb;
324 }
325 
326 
327 static void ieee80211_parse_qos(struct ieee80211_rx_data *rx)
328 {
329 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
330 	int tid;
331 
332 	/* does the frame have a qos control field? */
333 	if (ieee80211_is_data_qos(hdr->frame_control)) {
334 		u8 *qc = ieee80211_get_qos_ctl(hdr);
335 		/* frame has qos control */
336 		tid = *qc & IEEE80211_QOS_CTL_TID_MASK;
337 		if (*qc & IEEE80211_QOS_CONTROL_A_MSDU_PRESENT)
338 			rx->flags |= IEEE80211_RX_AMSDU;
339 		else
340 			rx->flags &= ~IEEE80211_RX_AMSDU;
341 	} else {
342 		/*
343 		 * IEEE 802.11-2007, 7.1.3.4.1 ("Sequence Number field"):
344 		 *
345 		 *	Sequence numbers for management frames, QoS data
346 		 *	frames with a broadcast/multicast address in the
347 		 *	Address 1 field, and all non-QoS data frames sent
348 		 *	by QoS STAs are assigned using an additional single
349 		 *	modulo-4096 counter, [...]
350 		 *
351 		 * We also use that counter for non-QoS STAs.
352 		 */
353 		tid = NUM_RX_DATA_QUEUES - 1;
354 	}
355 
356 	rx->queue = tid;
357 	/* Set skb->priority to 1d tag if highest order bit of TID is not set.
358 	 * For now, set skb->priority to 0 for other cases. */
359 	rx->skb->priority = (tid > 7) ? 0 : tid;
360 }
361 
362 static void ieee80211_verify_ip_alignment(struct ieee80211_rx_data *rx)
363 {
364 #ifdef CONFIG_MAC80211_DEBUG_PACKET_ALIGNMENT
365 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
366 	int hdrlen;
367 
368 	if (!ieee80211_is_data_present(hdr->frame_control))
369 		return;
370 
371 	/*
372 	 * Drivers are required to align the payload data in a way that
373 	 * guarantees that the contained IP header is aligned to a four-
374 	 * byte boundary. In the case of regular frames, this simply means
375 	 * aligning the payload to a four-byte boundary (because either
376 	 * the IP header is directly contained, or IV/RFC1042 headers that
377 	 * have a length divisible by four are in front of it.
378 	 *
379 	 * With A-MSDU frames, however, the payload data address must
380 	 * yield two modulo four because there are 14-byte 802.3 headers
381 	 * within the A-MSDU frames that push the IP header further back
382 	 * to a multiple of four again. Thankfully, the specs were sane
383 	 * enough this time around to require padding each A-MSDU subframe
384 	 * to a length that is a multiple of four.
385 	 *
386 	 * Padding like atheros hardware adds which is inbetween the 802.11
387 	 * header and the payload is not supported, the driver is required
388 	 * to move the 802.11 header further back in that case.
389 	 */
390 	hdrlen = ieee80211_hdrlen(hdr->frame_control);
391 	if (rx->flags & IEEE80211_RX_AMSDU)
392 		hdrlen += ETH_HLEN;
393 	WARN_ON_ONCE(((unsigned long)(rx->skb->data + hdrlen)) & 3);
394 #endif
395 }
396 
397 
398 /* rx handlers */
399 
400 static ieee80211_rx_result debug_noinline
401 ieee80211_rx_h_passive_scan(struct ieee80211_rx_data *rx)
402 {
403 	struct ieee80211_local *local = rx->local;
404 	struct sk_buff *skb = rx->skb;
405 
406 	if (unlikely(local->hw_scanning))
407 		return ieee80211_scan_rx(rx->sdata, skb, rx->status);
408 
409 	if (unlikely(local->sw_scanning)) {
410 		/* drop all the other packets during a software scan anyway */
411 		if (ieee80211_scan_rx(rx->sdata, skb, rx->status)
412 		    != RX_QUEUED)
413 			dev_kfree_skb(skb);
414 		return RX_QUEUED;
415 	}
416 
417 	if (unlikely(rx->flags & IEEE80211_RX_IN_SCAN)) {
418 		/* scanning finished during invoking of handlers */
419 		I802_DEBUG_INC(local->rx_handlers_drop_passive_scan);
420 		return RX_DROP_UNUSABLE;
421 	}
422 
423 	return RX_CONTINUE;
424 }
425 
426 static ieee80211_rx_result
427 ieee80211_rx_mesh_check(struct ieee80211_rx_data *rx)
428 {
429 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
430 	unsigned int hdrlen = ieee80211_hdrlen(hdr->frame_control);
431 
432 	if (ieee80211_is_data(hdr->frame_control)) {
433 		if (!ieee80211_has_a4(hdr->frame_control))
434 			return RX_DROP_MONITOR;
435 		if (memcmp(hdr->addr4, rx->dev->dev_addr, ETH_ALEN) == 0)
436 			return RX_DROP_MONITOR;
437 	}
438 
439 	/* If there is not an established peer link and this is not a peer link
440 	 * establisment frame, beacon or probe, drop the frame.
441 	 */
442 
443 	if (!rx->sta || sta_plink_state(rx->sta) != PLINK_ESTAB) {
444 		struct ieee80211_mgmt *mgmt;
445 
446 		if (!ieee80211_is_mgmt(hdr->frame_control))
447 			return RX_DROP_MONITOR;
448 
449 		if (ieee80211_is_action(hdr->frame_control)) {
450 			mgmt = (struct ieee80211_mgmt *)hdr;
451 			if (mgmt->u.action.category != PLINK_CATEGORY)
452 				return RX_DROP_MONITOR;
453 			return RX_CONTINUE;
454 		}
455 
456 		if (ieee80211_is_probe_req(hdr->frame_control) ||
457 		    ieee80211_is_probe_resp(hdr->frame_control) ||
458 		    ieee80211_is_beacon(hdr->frame_control))
459 			return RX_CONTINUE;
460 
461 		return RX_DROP_MONITOR;
462 
463 	}
464 
465 #define msh_h_get(h, l) ((struct ieee80211s_hdr *) ((u8 *)h + l))
466 
467 	if (ieee80211_is_data(hdr->frame_control) &&
468 	    is_multicast_ether_addr(hdr->addr1) &&
469 	    mesh_rmc_check(hdr->addr4, msh_h_get(hdr, hdrlen), rx->sdata))
470 		return RX_DROP_MONITOR;
471 #undef msh_h_get
472 
473 	return RX_CONTINUE;
474 }
475 
476 
477 static ieee80211_rx_result debug_noinline
478 ieee80211_rx_h_check(struct ieee80211_rx_data *rx)
479 {
480 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
481 
482 	/* Drop duplicate 802.11 retransmissions (IEEE 802.11 Chap. 9.2.9) */
483 	if (rx->sta && !is_multicast_ether_addr(hdr->addr1)) {
484 		if (unlikely(ieee80211_has_retry(hdr->frame_control) &&
485 			     rx->sta->last_seq_ctrl[rx->queue] ==
486 			     hdr->seq_ctrl)) {
487 			if (rx->flags & IEEE80211_RX_RA_MATCH) {
488 				rx->local->dot11FrameDuplicateCount++;
489 				rx->sta->num_duplicates++;
490 			}
491 			return RX_DROP_MONITOR;
492 		} else
493 			rx->sta->last_seq_ctrl[rx->queue] = hdr->seq_ctrl;
494 	}
495 
496 	if (unlikely(rx->skb->len < 16)) {
497 		I802_DEBUG_INC(rx->local->rx_handlers_drop_short);
498 		return RX_DROP_MONITOR;
499 	}
500 
501 	/* Drop disallowed frame classes based on STA auth/assoc state;
502 	 * IEEE 802.11, Chap 5.5.
503 	 *
504 	 * mac80211 filters only based on association state, i.e. it drops
505 	 * Class 3 frames from not associated stations. hostapd sends
506 	 * deauth/disassoc frames when needed. In addition, hostapd is
507 	 * responsible for filtering on both auth and assoc states.
508 	 */
509 
510 	if (ieee80211_vif_is_mesh(&rx->sdata->vif))
511 		return ieee80211_rx_mesh_check(rx);
512 
513 	if (unlikely((ieee80211_is_data(hdr->frame_control) ||
514 		      ieee80211_is_pspoll(hdr->frame_control)) &&
515 		     rx->sdata->vif.type != NL80211_IFTYPE_ADHOC &&
516 		     (!rx->sta || !test_sta_flags(rx->sta, WLAN_STA_ASSOC)))) {
517 		if ((!ieee80211_has_fromds(hdr->frame_control) &&
518 		     !ieee80211_has_tods(hdr->frame_control) &&
519 		     ieee80211_is_data(hdr->frame_control)) ||
520 		    !(rx->flags & IEEE80211_RX_RA_MATCH)) {
521 			/* Drop IBSS frames and frames for other hosts
522 			 * silently. */
523 			return RX_DROP_MONITOR;
524 		}
525 
526 		return RX_DROP_MONITOR;
527 	}
528 
529 	return RX_CONTINUE;
530 }
531 
532 
533 static ieee80211_rx_result debug_noinline
534 ieee80211_rx_h_decrypt(struct ieee80211_rx_data *rx)
535 {
536 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
537 	int keyidx;
538 	int hdrlen;
539 	ieee80211_rx_result result = RX_DROP_UNUSABLE;
540 	struct ieee80211_key *stakey = NULL;
541 
542 	/*
543 	 * Key selection 101
544 	 *
545 	 * There are three types of keys:
546 	 *  - GTK (group keys)
547 	 *  - PTK (pairwise keys)
548 	 *  - STK (station-to-station pairwise keys)
549 	 *
550 	 * When selecting a key, we have to distinguish between multicast
551 	 * (including broadcast) and unicast frames, the latter can only
552 	 * use PTKs and STKs while the former always use GTKs. Unless, of
553 	 * course, actual WEP keys ("pre-RSNA") are used, then unicast
554 	 * frames can also use key indizes like GTKs. Hence, if we don't
555 	 * have a PTK/STK we check the key index for a WEP key.
556 	 *
557 	 * Note that in a regular BSS, multicast frames are sent by the
558 	 * AP only, associated stations unicast the frame to the AP first
559 	 * which then multicasts it on their behalf.
560 	 *
561 	 * There is also a slight problem in IBSS mode: GTKs are negotiated
562 	 * with each station, that is something we don't currently handle.
563 	 * The spec seems to expect that one negotiates the same key with
564 	 * every station but there's no such requirement; VLANs could be
565 	 * possible.
566 	 */
567 
568 	if (!ieee80211_has_protected(hdr->frame_control))
569 		return RX_CONTINUE;
570 
571 	/*
572 	 * No point in finding a key and decrypting if the frame is neither
573 	 * addressed to us nor a multicast frame.
574 	 */
575 	if (!(rx->flags & IEEE80211_RX_RA_MATCH))
576 		return RX_CONTINUE;
577 
578 	if (rx->sta)
579 		stakey = rcu_dereference(rx->sta->key);
580 
581 	if (!is_multicast_ether_addr(hdr->addr1) && stakey) {
582 		rx->key = stakey;
583 	} else {
584 		/*
585 		 * The device doesn't give us the IV so we won't be
586 		 * able to look up the key. That's ok though, we
587 		 * don't need to decrypt the frame, we just won't
588 		 * be able to keep statistics accurate.
589 		 * Except for key threshold notifications, should
590 		 * we somehow allow the driver to tell us which key
591 		 * the hardware used if this flag is set?
592 		 */
593 		if ((rx->status->flag & RX_FLAG_DECRYPTED) &&
594 		    (rx->status->flag & RX_FLAG_IV_STRIPPED))
595 			return RX_CONTINUE;
596 
597 		hdrlen = ieee80211_hdrlen(hdr->frame_control);
598 
599 		if (rx->skb->len < 8 + hdrlen)
600 			return RX_DROP_UNUSABLE; /* TODO: count this? */
601 
602 		/*
603 		 * no need to call ieee80211_wep_get_keyidx,
604 		 * it verifies a bunch of things we've done already
605 		 */
606 		keyidx = rx->skb->data[hdrlen + 3] >> 6;
607 
608 		rx->key = rcu_dereference(rx->sdata->keys[keyidx]);
609 
610 		/*
611 		 * RSNA-protected unicast frames should always be sent with
612 		 * pairwise or station-to-station keys, but for WEP we allow
613 		 * using a key index as well.
614 		 */
615 		if (rx->key && rx->key->conf.alg != ALG_WEP &&
616 		    !is_multicast_ether_addr(hdr->addr1))
617 			rx->key = NULL;
618 	}
619 
620 	if (rx->key) {
621 		rx->key->tx_rx_count++;
622 		/* TODO: add threshold stuff again */
623 	} else {
624 		return RX_DROP_MONITOR;
625 	}
626 
627 	/* Check for weak IVs if possible */
628 	if (rx->sta && rx->key->conf.alg == ALG_WEP &&
629 	    ieee80211_is_data(hdr->frame_control) &&
630 	    (!(rx->status->flag & RX_FLAG_IV_STRIPPED) ||
631 	     !(rx->status->flag & RX_FLAG_DECRYPTED)) &&
632 	    ieee80211_wep_is_weak_iv(rx->skb, rx->key))
633 		rx->sta->wep_weak_iv_count++;
634 
635 	switch (rx->key->conf.alg) {
636 	case ALG_WEP:
637 		result = ieee80211_crypto_wep_decrypt(rx);
638 		break;
639 	case ALG_TKIP:
640 		result = ieee80211_crypto_tkip_decrypt(rx);
641 		break;
642 	case ALG_CCMP:
643 		result = ieee80211_crypto_ccmp_decrypt(rx);
644 		break;
645 	}
646 
647 	/* either the frame has been decrypted or will be dropped */
648 	rx->status->flag |= RX_FLAG_DECRYPTED;
649 
650 	return result;
651 }
652 
653 static void ap_sta_ps_start(struct sta_info *sta)
654 {
655 	struct ieee80211_sub_if_data *sdata = sta->sdata;
656 	DECLARE_MAC_BUF(mac);
657 
658 	atomic_inc(&sdata->bss->num_sta_ps);
659 	set_and_clear_sta_flags(sta, WLAN_STA_PS, WLAN_STA_PSPOLL);
660 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
661 	printk(KERN_DEBUG "%s: STA %s aid %d enters power save mode\n",
662 	       sdata->dev->name, print_mac(mac, sta->sta.addr), sta->sta.aid);
663 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
664 }
665 
666 static int ap_sta_ps_end(struct sta_info *sta)
667 {
668 	struct ieee80211_sub_if_data *sdata = sta->sdata;
669 	struct ieee80211_local *local = sdata->local;
670 	struct sk_buff *skb;
671 	int sent = 0;
672 	struct ieee80211_tx_info *info;
673 	DECLARE_MAC_BUF(mac);
674 
675 	atomic_dec(&sdata->bss->num_sta_ps);
676 
677 	clear_sta_flags(sta, WLAN_STA_PS | WLAN_STA_PSPOLL);
678 
679 	if (!skb_queue_empty(&sta->ps_tx_buf))
680 		sta_info_clear_tim_bit(sta);
681 
682 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
683 	printk(KERN_DEBUG "%s: STA %s aid %d exits power save mode\n",
684 	       sdata->dev->name, print_mac(mac, sta->sta.addr), sta->sta.aid);
685 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
686 
687 	/* Send all buffered frames to the station */
688 	while ((skb = skb_dequeue(&sta->tx_filtered)) != NULL) {
689 		info = IEEE80211_SKB_CB(skb);
690 		sent++;
691 		info->flags |= IEEE80211_TX_CTL_REQUEUE;
692 		dev_queue_xmit(skb);
693 	}
694 	while ((skb = skb_dequeue(&sta->ps_tx_buf)) != NULL) {
695 		info = IEEE80211_SKB_CB(skb);
696 		local->total_ps_buffered--;
697 		sent++;
698 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
699 		printk(KERN_DEBUG "%s: STA %s aid %d send PS frame "
700 		       "since STA not sleeping anymore\n", sdata->dev->name,
701 		       print_mac(mac, sta->sta.addr), sta->sta.aid);
702 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
703 		info->flags |= IEEE80211_TX_CTL_REQUEUE;
704 		dev_queue_xmit(skb);
705 	}
706 
707 	return sent;
708 }
709 
710 static ieee80211_rx_result debug_noinline
711 ieee80211_rx_h_sta_process(struct ieee80211_rx_data *rx)
712 {
713 	struct sta_info *sta = rx->sta;
714 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
715 
716 	if (!sta)
717 		return RX_CONTINUE;
718 
719 	/* Update last_rx only for IBSS packets which are for the current
720 	 * BSSID to avoid keeping the current IBSS network alive in cases where
721 	 * other STAs are using different BSSID. */
722 	if (rx->sdata->vif.type == NL80211_IFTYPE_ADHOC) {
723 		u8 *bssid = ieee80211_get_bssid(hdr, rx->skb->len,
724 						NL80211_IFTYPE_ADHOC);
725 		if (compare_ether_addr(bssid, rx->sdata->u.sta.bssid) == 0)
726 			sta->last_rx = jiffies;
727 	} else
728 	if (!is_multicast_ether_addr(hdr->addr1) ||
729 	    rx->sdata->vif.type == NL80211_IFTYPE_STATION) {
730 		/* Update last_rx only for unicast frames in order to prevent
731 		 * the Probe Request frames (the only broadcast frames from a
732 		 * STA in infrastructure mode) from keeping a connection alive.
733 		 * Mesh beacons will update last_rx when if they are found to
734 		 * match the current local configuration when processed.
735 		 */
736 		sta->last_rx = jiffies;
737 	}
738 
739 	if (!(rx->flags & IEEE80211_RX_RA_MATCH))
740 		return RX_CONTINUE;
741 
742 	sta->rx_fragments++;
743 	sta->rx_bytes += rx->skb->len;
744 	sta->last_signal = rx->status->signal;
745 	sta->last_qual = rx->status->qual;
746 	sta->last_noise = rx->status->noise;
747 
748 	if (!ieee80211_has_morefrags(hdr->frame_control) &&
749 	    (rx->sdata->vif.type == NL80211_IFTYPE_AP ||
750 	     rx->sdata->vif.type == NL80211_IFTYPE_AP_VLAN)) {
751 		/* Change STA power saving mode only in the end of a frame
752 		 * exchange sequence */
753 		if (test_sta_flags(sta, WLAN_STA_PS) &&
754 		    !ieee80211_has_pm(hdr->frame_control))
755 			rx->sent_ps_buffered += ap_sta_ps_end(sta);
756 		else if (!test_sta_flags(sta, WLAN_STA_PS) &&
757 			 ieee80211_has_pm(hdr->frame_control))
758 			ap_sta_ps_start(sta);
759 	}
760 
761 	/* Drop data::nullfunc frames silently, since they are used only to
762 	 * control station power saving mode. */
763 	if (ieee80211_is_nullfunc(hdr->frame_control)) {
764 		I802_DEBUG_INC(rx->local->rx_handlers_drop_nullfunc);
765 		/* Update counter and free packet here to avoid counting this
766 		 * as a dropped packed. */
767 		sta->rx_packets++;
768 		dev_kfree_skb(rx->skb);
769 		return RX_QUEUED;
770 	}
771 
772 	return RX_CONTINUE;
773 } /* ieee80211_rx_h_sta_process */
774 
775 static inline struct ieee80211_fragment_entry *
776 ieee80211_reassemble_add(struct ieee80211_sub_if_data *sdata,
777 			 unsigned int frag, unsigned int seq, int rx_queue,
778 			 struct sk_buff **skb)
779 {
780 	struct ieee80211_fragment_entry *entry;
781 	int idx;
782 
783 	idx = sdata->fragment_next;
784 	entry = &sdata->fragments[sdata->fragment_next++];
785 	if (sdata->fragment_next >= IEEE80211_FRAGMENT_MAX)
786 		sdata->fragment_next = 0;
787 
788 	if (!skb_queue_empty(&entry->skb_list)) {
789 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG
790 		struct ieee80211_hdr *hdr =
791 			(struct ieee80211_hdr *) entry->skb_list.next->data;
792 		DECLARE_MAC_BUF(mac);
793 		DECLARE_MAC_BUF(mac2);
794 		printk(KERN_DEBUG "%s: RX reassembly removed oldest "
795 		       "fragment entry (idx=%d age=%lu seq=%d last_frag=%d "
796 		       "addr1=%s addr2=%s\n",
797 		       sdata->dev->name, idx,
798 		       jiffies - entry->first_frag_time, entry->seq,
799 		       entry->last_frag, print_mac(mac, hdr->addr1),
800 		       print_mac(mac2, hdr->addr2));
801 #endif
802 		__skb_queue_purge(&entry->skb_list);
803 	}
804 
805 	__skb_queue_tail(&entry->skb_list, *skb); /* no need for locking */
806 	*skb = NULL;
807 	entry->first_frag_time = jiffies;
808 	entry->seq = seq;
809 	entry->rx_queue = rx_queue;
810 	entry->last_frag = frag;
811 	entry->ccmp = 0;
812 	entry->extra_len = 0;
813 
814 	return entry;
815 }
816 
817 static inline struct ieee80211_fragment_entry *
818 ieee80211_reassemble_find(struct ieee80211_sub_if_data *sdata,
819 			  unsigned int frag, unsigned int seq,
820 			  int rx_queue, struct ieee80211_hdr *hdr)
821 {
822 	struct ieee80211_fragment_entry *entry;
823 	int i, idx;
824 
825 	idx = sdata->fragment_next;
826 	for (i = 0; i < IEEE80211_FRAGMENT_MAX; i++) {
827 		struct ieee80211_hdr *f_hdr;
828 
829 		idx--;
830 		if (idx < 0)
831 			idx = IEEE80211_FRAGMENT_MAX - 1;
832 
833 		entry = &sdata->fragments[idx];
834 		if (skb_queue_empty(&entry->skb_list) || entry->seq != seq ||
835 		    entry->rx_queue != rx_queue ||
836 		    entry->last_frag + 1 != frag)
837 			continue;
838 
839 		f_hdr = (struct ieee80211_hdr *)entry->skb_list.next->data;
840 
841 		/*
842 		 * Check ftype and addresses are equal, else check next fragment
843 		 */
844 		if (((hdr->frame_control ^ f_hdr->frame_control) &
845 		     cpu_to_le16(IEEE80211_FCTL_FTYPE)) ||
846 		    compare_ether_addr(hdr->addr1, f_hdr->addr1) != 0 ||
847 		    compare_ether_addr(hdr->addr2, f_hdr->addr2) != 0)
848 			continue;
849 
850 		if (time_after(jiffies, entry->first_frag_time + 2 * HZ)) {
851 			__skb_queue_purge(&entry->skb_list);
852 			continue;
853 		}
854 		return entry;
855 	}
856 
857 	return NULL;
858 }
859 
860 static ieee80211_rx_result debug_noinline
861 ieee80211_rx_h_defragment(struct ieee80211_rx_data *rx)
862 {
863 	struct ieee80211_hdr *hdr;
864 	u16 sc;
865 	__le16 fc;
866 	unsigned int frag, seq;
867 	struct ieee80211_fragment_entry *entry;
868 	struct sk_buff *skb;
869 	DECLARE_MAC_BUF(mac);
870 
871 	hdr = (struct ieee80211_hdr *)rx->skb->data;
872 	fc = hdr->frame_control;
873 	sc = le16_to_cpu(hdr->seq_ctrl);
874 	frag = sc & IEEE80211_SCTL_FRAG;
875 
876 	if (likely((!ieee80211_has_morefrags(fc) && frag == 0) ||
877 		   (rx->skb)->len < 24 ||
878 		   is_multicast_ether_addr(hdr->addr1))) {
879 		/* not fragmented */
880 		goto out;
881 	}
882 	I802_DEBUG_INC(rx->local->rx_handlers_fragments);
883 
884 	seq = (sc & IEEE80211_SCTL_SEQ) >> 4;
885 
886 	if (frag == 0) {
887 		/* This is the first fragment of a new frame. */
888 		entry = ieee80211_reassemble_add(rx->sdata, frag, seq,
889 						 rx->queue, &(rx->skb));
890 		if (rx->key && rx->key->conf.alg == ALG_CCMP &&
891 		    ieee80211_has_protected(fc)) {
892 			/* Store CCMP PN so that we can verify that the next
893 			 * fragment has a sequential PN value. */
894 			entry->ccmp = 1;
895 			memcpy(entry->last_pn,
896 			       rx->key->u.ccmp.rx_pn[rx->queue],
897 			       CCMP_PN_LEN);
898 		}
899 		return RX_QUEUED;
900 	}
901 
902 	/* This is a fragment for a frame that should already be pending in
903 	 * fragment cache. Add this fragment to the end of the pending entry.
904 	 */
905 	entry = ieee80211_reassemble_find(rx->sdata, frag, seq, rx->queue, hdr);
906 	if (!entry) {
907 		I802_DEBUG_INC(rx->local->rx_handlers_drop_defrag);
908 		return RX_DROP_MONITOR;
909 	}
910 
911 	/* Verify that MPDUs within one MSDU have sequential PN values.
912 	 * (IEEE 802.11i, 8.3.3.4.5) */
913 	if (entry->ccmp) {
914 		int i;
915 		u8 pn[CCMP_PN_LEN], *rpn;
916 		if (!rx->key || rx->key->conf.alg != ALG_CCMP)
917 			return RX_DROP_UNUSABLE;
918 		memcpy(pn, entry->last_pn, CCMP_PN_LEN);
919 		for (i = CCMP_PN_LEN - 1; i >= 0; i--) {
920 			pn[i]++;
921 			if (pn[i])
922 				break;
923 		}
924 		rpn = rx->key->u.ccmp.rx_pn[rx->queue];
925 		if (memcmp(pn, rpn, CCMP_PN_LEN))
926 			return RX_DROP_UNUSABLE;
927 		memcpy(entry->last_pn, pn, CCMP_PN_LEN);
928 	}
929 
930 	skb_pull(rx->skb, ieee80211_hdrlen(fc));
931 	__skb_queue_tail(&entry->skb_list, rx->skb);
932 	entry->last_frag = frag;
933 	entry->extra_len += rx->skb->len;
934 	if (ieee80211_has_morefrags(fc)) {
935 		rx->skb = NULL;
936 		return RX_QUEUED;
937 	}
938 
939 	rx->skb = __skb_dequeue(&entry->skb_list);
940 	if (skb_tailroom(rx->skb) < entry->extra_len) {
941 		I802_DEBUG_INC(rx->local->rx_expand_skb_head2);
942 		if (unlikely(pskb_expand_head(rx->skb, 0, entry->extra_len,
943 					      GFP_ATOMIC))) {
944 			I802_DEBUG_INC(rx->local->rx_handlers_drop_defrag);
945 			__skb_queue_purge(&entry->skb_list);
946 			return RX_DROP_UNUSABLE;
947 		}
948 	}
949 	while ((skb = __skb_dequeue(&entry->skb_list))) {
950 		memcpy(skb_put(rx->skb, skb->len), skb->data, skb->len);
951 		dev_kfree_skb(skb);
952 	}
953 
954 	/* Complete frame has been reassembled - process it now */
955 	rx->flags |= IEEE80211_RX_FRAGMENTED;
956 
957  out:
958 	if (rx->sta)
959 		rx->sta->rx_packets++;
960 	if (is_multicast_ether_addr(hdr->addr1))
961 		rx->local->dot11MulticastReceivedFrameCount++;
962 	else
963 		ieee80211_led_rx(rx->local);
964 	return RX_CONTINUE;
965 }
966 
967 static ieee80211_rx_result debug_noinline
968 ieee80211_rx_h_ps_poll(struct ieee80211_rx_data *rx)
969 {
970 	struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(rx->dev);
971 	struct sk_buff *skb;
972 	int no_pending_pkts;
973 	DECLARE_MAC_BUF(mac);
974 	__le16 fc = ((struct ieee80211_hdr *)rx->skb->data)->frame_control;
975 
976 	if (likely(!rx->sta || !ieee80211_is_pspoll(fc) ||
977 		   !(rx->flags & IEEE80211_RX_RA_MATCH)))
978 		return RX_CONTINUE;
979 
980 	if ((sdata->vif.type != NL80211_IFTYPE_AP) &&
981 	    (sdata->vif.type != NL80211_IFTYPE_AP_VLAN))
982 		return RX_DROP_UNUSABLE;
983 
984 	skb = skb_dequeue(&rx->sta->tx_filtered);
985 	if (!skb) {
986 		skb = skb_dequeue(&rx->sta->ps_tx_buf);
987 		if (skb)
988 			rx->local->total_ps_buffered--;
989 	}
990 	no_pending_pkts = skb_queue_empty(&rx->sta->tx_filtered) &&
991 		skb_queue_empty(&rx->sta->ps_tx_buf);
992 
993 	if (skb) {
994 		struct ieee80211_hdr *hdr =
995 			(struct ieee80211_hdr *) skb->data;
996 
997 		/*
998 		 * Tell TX path to send one frame even though the STA may
999 		 * still remain is PS mode after this frame exchange.
1000 		 */
1001 		set_sta_flags(rx->sta, WLAN_STA_PSPOLL);
1002 
1003 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
1004 		printk(KERN_DEBUG "STA %s aid %d: PS Poll (entries after %d)\n",
1005 		       print_mac(mac, rx->sta->sta.addr), rx->sta->sta.aid,
1006 		       skb_queue_len(&rx->sta->ps_tx_buf));
1007 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
1008 
1009 		/* Use MoreData flag to indicate whether there are more
1010 		 * buffered frames for this STA */
1011 		if (no_pending_pkts)
1012 			hdr->frame_control &= cpu_to_le16(~IEEE80211_FCTL_MOREDATA);
1013 		else
1014 			hdr->frame_control |= cpu_to_le16(IEEE80211_FCTL_MOREDATA);
1015 
1016 		dev_queue_xmit(skb);
1017 
1018 		if (no_pending_pkts)
1019 			sta_info_clear_tim_bit(rx->sta);
1020 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
1021 	} else if (!rx->sent_ps_buffered) {
1022 		/*
1023 		 * FIXME: This can be the result of a race condition between
1024 		 *	  us expiring a frame and the station polling for it.
1025 		 *	  Should we send it a null-func frame indicating we
1026 		 *	  have nothing buffered for it?
1027 		 */
1028 		printk(KERN_DEBUG "%s: STA %s sent PS Poll even "
1029 		       "though there are no buffered frames for it\n",
1030 		       rx->dev->name, print_mac(mac, rx->sta->sta.addr));
1031 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
1032 	}
1033 
1034 	/* Free PS Poll skb here instead of returning RX_DROP that would
1035 	 * count as an dropped frame. */
1036 	dev_kfree_skb(rx->skb);
1037 
1038 	return RX_QUEUED;
1039 }
1040 
1041 static ieee80211_rx_result debug_noinline
1042 ieee80211_rx_h_remove_qos_control(struct ieee80211_rx_data *rx)
1043 {
1044 	u8 *data = rx->skb->data;
1045 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)data;
1046 
1047 	if (!ieee80211_is_data_qos(hdr->frame_control))
1048 		return RX_CONTINUE;
1049 
1050 	/* remove the qos control field, update frame type and meta-data */
1051 	memmove(data + IEEE80211_QOS_CTL_LEN, data,
1052 		ieee80211_hdrlen(hdr->frame_control) - IEEE80211_QOS_CTL_LEN);
1053 	hdr = (struct ieee80211_hdr *)skb_pull(rx->skb, IEEE80211_QOS_CTL_LEN);
1054 	/* change frame type to non QOS */
1055 	hdr->frame_control &= ~cpu_to_le16(IEEE80211_STYPE_QOS_DATA);
1056 
1057 	return RX_CONTINUE;
1058 }
1059 
1060 static int
1061 ieee80211_802_1x_port_control(struct ieee80211_rx_data *rx)
1062 {
1063 	if (unlikely(!rx->sta ||
1064 	    !test_sta_flags(rx->sta, WLAN_STA_AUTHORIZED)))
1065 		return -EACCES;
1066 
1067 	return 0;
1068 }
1069 
1070 static int
1071 ieee80211_drop_unencrypted(struct ieee80211_rx_data *rx, __le16 fc)
1072 {
1073 	/*
1074 	 * Pass through unencrypted frames if the hardware has
1075 	 * decrypted them already.
1076 	 */
1077 	if (rx->status->flag & RX_FLAG_DECRYPTED)
1078 		return 0;
1079 
1080 	/* Drop unencrypted frames if key is set. */
1081 	if (unlikely(!ieee80211_has_protected(fc) &&
1082 		     !ieee80211_is_nullfunc(fc) &&
1083 		     (rx->key || rx->sdata->drop_unencrypted)))
1084 		return -EACCES;
1085 
1086 	return 0;
1087 }
1088 
1089 static int
1090 ieee80211_data_to_8023(struct ieee80211_rx_data *rx)
1091 {
1092 	struct net_device *dev = rx->dev;
1093 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) rx->skb->data;
1094 	u16 hdrlen, ethertype;
1095 	u8 *payload;
1096 	u8 dst[ETH_ALEN];
1097 	u8 src[ETH_ALEN] __aligned(2);
1098 	struct sk_buff *skb = rx->skb;
1099 	struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
1100 	DECLARE_MAC_BUF(mac);
1101 	DECLARE_MAC_BUF(mac2);
1102 	DECLARE_MAC_BUF(mac3);
1103 	DECLARE_MAC_BUF(mac4);
1104 
1105 	if (unlikely(!ieee80211_is_data_present(hdr->frame_control)))
1106 		return -1;
1107 
1108 	hdrlen = ieee80211_hdrlen(hdr->frame_control);
1109 
1110 	/* convert IEEE 802.11 header + possible LLC headers into Ethernet
1111 	 * header
1112 	 * IEEE 802.11 address fields:
1113 	 * ToDS FromDS Addr1 Addr2 Addr3 Addr4
1114 	 *   0     0   DA    SA    BSSID n/a
1115 	 *   0     1   DA    BSSID SA    n/a
1116 	 *   1     0   BSSID SA    DA    n/a
1117 	 *   1     1   RA    TA    DA    SA
1118 	 */
1119 	memcpy(dst, ieee80211_get_DA(hdr), ETH_ALEN);
1120 	memcpy(src, ieee80211_get_SA(hdr), ETH_ALEN);
1121 
1122 	switch (hdr->frame_control &
1123 		cpu_to_le16(IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS)) {
1124 	case __constant_cpu_to_le16(IEEE80211_FCTL_TODS):
1125 		if (unlikely(sdata->vif.type != NL80211_IFTYPE_AP &&
1126 			     sdata->vif.type != NL80211_IFTYPE_AP_VLAN))
1127 			return -1;
1128 		break;
1129 	case __constant_cpu_to_le16(IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS):
1130 		if (unlikely(sdata->vif.type != NL80211_IFTYPE_WDS &&
1131 			     sdata->vif.type != NL80211_IFTYPE_MESH_POINT))
1132 			return -1;
1133 		if (ieee80211_vif_is_mesh(&sdata->vif)) {
1134 			struct ieee80211s_hdr *meshdr = (struct ieee80211s_hdr *)
1135 				(skb->data + hdrlen);
1136 			hdrlen += ieee80211_get_mesh_hdrlen(meshdr);
1137 			if (meshdr->flags & MESH_FLAGS_AE_A5_A6) {
1138 				memcpy(dst, meshdr->eaddr1, ETH_ALEN);
1139 				memcpy(src, meshdr->eaddr2, ETH_ALEN);
1140 			}
1141 		}
1142 		break;
1143 	case __constant_cpu_to_le16(IEEE80211_FCTL_FROMDS):
1144 		if (sdata->vif.type != NL80211_IFTYPE_STATION ||
1145 		    (is_multicast_ether_addr(dst) &&
1146 		     !compare_ether_addr(src, dev->dev_addr)))
1147 			return -1;
1148 		break;
1149 	case __constant_cpu_to_le16(0):
1150 		if (sdata->vif.type != NL80211_IFTYPE_ADHOC)
1151 			return -1;
1152 		break;
1153 	}
1154 
1155 	if (unlikely(skb->len - hdrlen < 8))
1156 		return -1;
1157 
1158 	payload = skb->data + hdrlen;
1159 	ethertype = (payload[6] << 8) | payload[7];
1160 
1161 	if (likely((compare_ether_addr(payload, rfc1042_header) == 0 &&
1162 		    ethertype != ETH_P_AARP && ethertype != ETH_P_IPX) ||
1163 		   compare_ether_addr(payload, bridge_tunnel_header) == 0)) {
1164 		/* remove RFC1042 or Bridge-Tunnel encapsulation and
1165 		 * replace EtherType */
1166 		skb_pull(skb, hdrlen + 6);
1167 		memcpy(skb_push(skb, ETH_ALEN), src, ETH_ALEN);
1168 		memcpy(skb_push(skb, ETH_ALEN), dst, ETH_ALEN);
1169 	} else {
1170 		struct ethhdr *ehdr;
1171 		__be16 len;
1172 
1173 		skb_pull(skb, hdrlen);
1174 		len = htons(skb->len);
1175 		ehdr = (struct ethhdr *) skb_push(skb, sizeof(struct ethhdr));
1176 		memcpy(ehdr->h_dest, dst, ETH_ALEN);
1177 		memcpy(ehdr->h_source, src, ETH_ALEN);
1178 		ehdr->h_proto = len;
1179 	}
1180 	return 0;
1181 }
1182 
1183 /*
1184  * requires that rx->skb is a frame with ethernet header
1185  */
1186 static bool ieee80211_frame_allowed(struct ieee80211_rx_data *rx, __le16 fc)
1187 {
1188 	static const u8 pae_group_addr[ETH_ALEN] __aligned(2)
1189 		= { 0x01, 0x80, 0xC2, 0x00, 0x00, 0x03 };
1190 	struct ethhdr *ehdr = (struct ethhdr *) rx->skb->data;
1191 
1192 	/*
1193 	 * Allow EAPOL frames to us/the PAE group address regardless
1194 	 * of whether the frame was encrypted or not.
1195 	 */
1196 	if (ehdr->h_proto == htons(ETH_P_PAE) &&
1197 	    (compare_ether_addr(ehdr->h_dest, rx->dev->dev_addr) == 0 ||
1198 	     compare_ether_addr(ehdr->h_dest, pae_group_addr) == 0))
1199 		return true;
1200 
1201 	if (ieee80211_802_1x_port_control(rx) ||
1202 	    ieee80211_drop_unencrypted(rx, fc))
1203 		return false;
1204 
1205 	return true;
1206 }
1207 
1208 /*
1209  * requires that rx->skb is a frame with ethernet header
1210  */
1211 static void
1212 ieee80211_deliver_skb(struct ieee80211_rx_data *rx)
1213 {
1214 	struct net_device *dev = rx->dev;
1215 	struct ieee80211_local *local = rx->local;
1216 	struct sk_buff *skb, *xmit_skb;
1217 	struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
1218 	struct ethhdr *ehdr = (struct ethhdr *) rx->skb->data;
1219 	struct sta_info *dsta;
1220 
1221 	skb = rx->skb;
1222 	xmit_skb = NULL;
1223 
1224 	if ((sdata->vif.type == NL80211_IFTYPE_AP ||
1225 	     sdata->vif.type == NL80211_IFTYPE_AP_VLAN) &&
1226 	    !(sdata->flags & IEEE80211_SDATA_DONT_BRIDGE_PACKETS) &&
1227 	    (rx->flags & IEEE80211_RX_RA_MATCH)) {
1228 		if (is_multicast_ether_addr(ehdr->h_dest)) {
1229 			/*
1230 			 * send multicast frames both to higher layers in
1231 			 * local net stack and back to the wireless medium
1232 			 */
1233 			xmit_skb = skb_copy(skb, GFP_ATOMIC);
1234 			if (!xmit_skb && net_ratelimit())
1235 				printk(KERN_DEBUG "%s: failed to clone "
1236 				       "multicast frame\n", dev->name);
1237 		} else {
1238 			dsta = sta_info_get(local, skb->data);
1239 			if (dsta && dsta->sdata->dev == dev) {
1240 				/*
1241 				 * The destination station is associated to
1242 				 * this AP (in this VLAN), so send the frame
1243 				 * directly to it and do not pass it to local
1244 				 * net stack.
1245 				 */
1246 				xmit_skb = skb;
1247 				skb = NULL;
1248 			}
1249 		}
1250 	}
1251 
1252 	if (skb) {
1253 		/* deliver to local stack */
1254 		skb->protocol = eth_type_trans(skb, dev);
1255 		memset(skb->cb, 0, sizeof(skb->cb));
1256 		netif_rx(skb);
1257 	}
1258 
1259 	if (xmit_skb) {
1260 		/* send to wireless media */
1261 		xmit_skb->protocol = htons(ETH_P_802_3);
1262 		skb_reset_network_header(xmit_skb);
1263 		skb_reset_mac_header(xmit_skb);
1264 		dev_queue_xmit(xmit_skb);
1265 	}
1266 }
1267 
1268 static ieee80211_rx_result debug_noinline
1269 ieee80211_rx_h_amsdu(struct ieee80211_rx_data *rx)
1270 {
1271 	struct net_device *dev = rx->dev;
1272 	struct ieee80211_local *local = rx->local;
1273 	u16 ethertype;
1274 	u8 *payload;
1275 	struct sk_buff *skb = rx->skb, *frame = NULL;
1276 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
1277 	__le16 fc = hdr->frame_control;
1278 	const struct ethhdr *eth;
1279 	int remaining, err;
1280 	u8 dst[ETH_ALEN];
1281 	u8 src[ETH_ALEN];
1282 	DECLARE_MAC_BUF(mac);
1283 
1284 	if (unlikely(!ieee80211_is_data(fc)))
1285 		return RX_CONTINUE;
1286 
1287 	if (unlikely(!ieee80211_is_data_present(fc)))
1288 		return RX_DROP_MONITOR;
1289 
1290 	if (!(rx->flags & IEEE80211_RX_AMSDU))
1291 		return RX_CONTINUE;
1292 
1293 	err = ieee80211_data_to_8023(rx);
1294 	if (unlikely(err))
1295 		return RX_DROP_UNUSABLE;
1296 
1297 	skb->dev = dev;
1298 
1299 	dev->stats.rx_packets++;
1300 	dev->stats.rx_bytes += skb->len;
1301 
1302 	/* skip the wrapping header */
1303 	eth = (struct ethhdr *) skb_pull(skb, sizeof(struct ethhdr));
1304 	if (!eth)
1305 		return RX_DROP_UNUSABLE;
1306 
1307 	while (skb != frame) {
1308 		u8 padding;
1309 		__be16 len = eth->h_proto;
1310 		unsigned int subframe_len = sizeof(struct ethhdr) + ntohs(len);
1311 
1312 		remaining = skb->len;
1313 		memcpy(dst, eth->h_dest, ETH_ALEN);
1314 		memcpy(src, eth->h_source, ETH_ALEN);
1315 
1316 		padding = ((4 - subframe_len) & 0x3);
1317 		/* the last MSDU has no padding */
1318 		if (subframe_len > remaining)
1319 			return RX_DROP_UNUSABLE;
1320 
1321 		skb_pull(skb, sizeof(struct ethhdr));
1322 		/* if last subframe reuse skb */
1323 		if (remaining <= subframe_len + padding)
1324 			frame = skb;
1325 		else {
1326 			frame = dev_alloc_skb(local->hw.extra_tx_headroom +
1327 					      subframe_len);
1328 
1329 			if (frame == NULL)
1330 				return RX_DROP_UNUSABLE;
1331 
1332 			skb_reserve(frame, local->hw.extra_tx_headroom +
1333 				    sizeof(struct ethhdr));
1334 			memcpy(skb_put(frame, ntohs(len)), skb->data,
1335 				ntohs(len));
1336 
1337 			eth = (struct ethhdr *) skb_pull(skb, ntohs(len) +
1338 							padding);
1339 			if (!eth) {
1340 				dev_kfree_skb(frame);
1341 				return RX_DROP_UNUSABLE;
1342 			}
1343 		}
1344 
1345 		skb_reset_network_header(frame);
1346 		frame->dev = dev;
1347 		frame->priority = skb->priority;
1348 		rx->skb = frame;
1349 
1350 		payload = frame->data;
1351 		ethertype = (payload[6] << 8) | payload[7];
1352 
1353 		if (likely((compare_ether_addr(payload, rfc1042_header) == 0 &&
1354 			    ethertype != ETH_P_AARP && ethertype != ETH_P_IPX) ||
1355 			   compare_ether_addr(payload,
1356 					      bridge_tunnel_header) == 0)) {
1357 			/* remove RFC1042 or Bridge-Tunnel
1358 			 * encapsulation and replace EtherType */
1359 			skb_pull(frame, 6);
1360 			memcpy(skb_push(frame, ETH_ALEN), src, ETH_ALEN);
1361 			memcpy(skb_push(frame, ETH_ALEN), dst, ETH_ALEN);
1362 		} else {
1363 			memcpy(skb_push(frame, sizeof(__be16)),
1364 			       &len, sizeof(__be16));
1365 			memcpy(skb_push(frame, ETH_ALEN), src, ETH_ALEN);
1366 			memcpy(skb_push(frame, ETH_ALEN), dst, ETH_ALEN);
1367 		}
1368 
1369 		if (!ieee80211_frame_allowed(rx, fc)) {
1370 			if (skb == frame) /* last frame */
1371 				return RX_DROP_UNUSABLE;
1372 			dev_kfree_skb(frame);
1373 			continue;
1374 		}
1375 
1376 		ieee80211_deliver_skb(rx);
1377 	}
1378 
1379 	return RX_QUEUED;
1380 }
1381 
1382 #ifdef CONFIG_MAC80211_MESH
1383 static ieee80211_rx_result
1384 ieee80211_rx_h_mesh_fwding(struct ieee80211_rx_data *rx)
1385 {
1386 	struct ieee80211_hdr *hdr;
1387 	struct ieee80211s_hdr *mesh_hdr;
1388 	unsigned int hdrlen;
1389 	struct sk_buff *skb = rx->skb, *fwd_skb;
1390 
1391 	hdr = (struct ieee80211_hdr *) skb->data;
1392 	hdrlen = ieee80211_hdrlen(hdr->frame_control);
1393 	mesh_hdr = (struct ieee80211s_hdr *) (skb->data + hdrlen);
1394 
1395 	if (!ieee80211_is_data(hdr->frame_control))
1396 		return RX_CONTINUE;
1397 
1398 	if (!mesh_hdr->ttl)
1399 		/* illegal frame */
1400 		return RX_DROP_MONITOR;
1401 
1402 	if (mesh_hdr->flags & MESH_FLAGS_AE_A5_A6){
1403 		struct ieee80211_sub_if_data *sdata;
1404 		struct mesh_path *mppath;
1405 
1406 		sdata = IEEE80211_DEV_TO_SUB_IF(rx->dev);
1407 		rcu_read_lock();
1408 		mppath = mpp_path_lookup(mesh_hdr->eaddr2, sdata);
1409 		if (!mppath) {
1410 			mpp_path_add(mesh_hdr->eaddr2, hdr->addr4, sdata);
1411 		} else {
1412 			spin_lock_bh(&mppath->state_lock);
1413 			mppath->exp_time = jiffies;
1414 			if (compare_ether_addr(mppath->mpp, hdr->addr4) != 0)
1415 				memcpy(mppath->mpp, hdr->addr4, ETH_ALEN);
1416 			spin_unlock_bh(&mppath->state_lock);
1417 		}
1418 		rcu_read_unlock();
1419 	}
1420 
1421 	if (compare_ether_addr(rx->dev->dev_addr, hdr->addr3) == 0)
1422 		return RX_CONTINUE;
1423 
1424 	mesh_hdr->ttl--;
1425 
1426 	if (rx->flags & IEEE80211_RX_RA_MATCH) {
1427 		if (!mesh_hdr->ttl)
1428 			IEEE80211_IFSTA_MESH_CTR_INC(&rx->sdata->u.mesh,
1429 						     dropped_frames_ttl);
1430 		else {
1431 			struct ieee80211_hdr *fwd_hdr;
1432 			fwd_skb = skb_copy(skb, GFP_ATOMIC);
1433 
1434 			if (!fwd_skb && net_ratelimit())
1435 				printk(KERN_DEBUG "%s: failed to clone mesh frame\n",
1436 						   rx->dev->name);
1437 
1438 			fwd_hdr =  (struct ieee80211_hdr *) fwd_skb->data;
1439 			/*
1440 			 * Save TA to addr1 to send TA a path error if a
1441 			 * suitable next hop is not found
1442 			 */
1443 			memcpy(fwd_hdr->addr1, fwd_hdr->addr2, ETH_ALEN);
1444 			memcpy(fwd_hdr->addr2, rx->dev->dev_addr, ETH_ALEN);
1445 			fwd_skb->dev = rx->local->mdev;
1446 			fwd_skb->iif = rx->dev->ifindex;
1447 			dev_queue_xmit(fwd_skb);
1448 		}
1449 	}
1450 
1451 	if (is_multicast_ether_addr(hdr->addr3) ||
1452 	    rx->dev->flags & IFF_PROMISC)
1453 		return RX_CONTINUE;
1454 	else
1455 		return RX_DROP_MONITOR;
1456 }
1457 #endif
1458 
1459 static ieee80211_rx_result debug_noinline
1460 ieee80211_rx_h_data(struct ieee80211_rx_data *rx)
1461 {
1462 	struct net_device *dev = rx->dev;
1463 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
1464 	__le16 fc = hdr->frame_control;
1465 	int err;
1466 
1467 	if (unlikely(!ieee80211_is_data(hdr->frame_control)))
1468 		return RX_CONTINUE;
1469 
1470 	if (unlikely(!ieee80211_is_data_present(hdr->frame_control)))
1471 		return RX_DROP_MONITOR;
1472 
1473 	err = ieee80211_data_to_8023(rx);
1474 	if (unlikely(err))
1475 		return RX_DROP_UNUSABLE;
1476 
1477 	if (!ieee80211_frame_allowed(rx, fc))
1478 		return RX_DROP_MONITOR;
1479 
1480 	rx->skb->dev = dev;
1481 
1482 	dev->stats.rx_packets++;
1483 	dev->stats.rx_bytes += rx->skb->len;
1484 
1485 	ieee80211_deliver_skb(rx);
1486 
1487 	return RX_QUEUED;
1488 }
1489 
1490 static ieee80211_rx_result debug_noinline
1491 ieee80211_rx_h_ctrl(struct ieee80211_rx_data *rx)
1492 {
1493 	struct ieee80211_local *local = rx->local;
1494 	struct ieee80211_hw *hw = &local->hw;
1495 	struct sk_buff *skb = rx->skb;
1496 	struct ieee80211_bar *bar = (struct ieee80211_bar *)skb->data;
1497 	struct tid_ampdu_rx *tid_agg_rx;
1498 	u16 start_seq_num;
1499 	u16 tid;
1500 
1501 	if (likely(!ieee80211_is_ctl(bar->frame_control)))
1502 		return RX_CONTINUE;
1503 
1504 	if (ieee80211_is_back_req(bar->frame_control)) {
1505 		if (!rx->sta)
1506 			return RX_CONTINUE;
1507 		tid = le16_to_cpu(bar->control) >> 12;
1508 		if (rx->sta->ampdu_mlme.tid_state_rx[tid]
1509 					!= HT_AGG_STATE_OPERATIONAL)
1510 			return RX_CONTINUE;
1511 		tid_agg_rx = rx->sta->ampdu_mlme.tid_rx[tid];
1512 
1513 		start_seq_num = le16_to_cpu(bar->start_seq_num) >> 4;
1514 
1515 		/* reset session timer */
1516 		if (tid_agg_rx->timeout) {
1517 			unsigned long expires =
1518 				jiffies + (tid_agg_rx->timeout / 1000) * HZ;
1519 			mod_timer(&tid_agg_rx->session_timer, expires);
1520 		}
1521 
1522 		/* manage reordering buffer according to requested */
1523 		/* sequence number */
1524 		rcu_read_lock();
1525 		ieee80211_sta_manage_reorder_buf(hw, tid_agg_rx, NULL,
1526 						 start_seq_num, 1);
1527 		rcu_read_unlock();
1528 		return RX_DROP_UNUSABLE;
1529 	}
1530 
1531 	return RX_CONTINUE;
1532 }
1533 
1534 static ieee80211_rx_result debug_noinline
1535 ieee80211_rx_h_action(struct ieee80211_rx_data *rx)
1536 {
1537 	struct ieee80211_local *local = rx->local;
1538 	struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(rx->dev);
1539 	struct ieee80211_mgmt *mgmt = (struct ieee80211_mgmt *) rx->skb->data;
1540 	int len = rx->skb->len;
1541 
1542 	if (!ieee80211_is_action(mgmt->frame_control))
1543 		return RX_CONTINUE;
1544 
1545 	if (!rx->sta)
1546 		return RX_DROP_MONITOR;
1547 
1548 	if (!(rx->flags & IEEE80211_RX_RA_MATCH))
1549 		return RX_DROP_MONITOR;
1550 
1551 	/* all categories we currently handle have action_code */
1552 	if (len < IEEE80211_MIN_ACTION_SIZE + 1)
1553 		return RX_DROP_MONITOR;
1554 
1555 	/*
1556 	 * FIXME: revisit this, I'm sure we should handle most
1557 	 *	  of these frames in other modes as well!
1558 	 */
1559 	if (sdata->vif.type != NL80211_IFTYPE_STATION &&
1560 	    sdata->vif.type != NL80211_IFTYPE_ADHOC)
1561 		return RX_CONTINUE;
1562 
1563 	switch (mgmt->u.action.category) {
1564 	case WLAN_CATEGORY_BACK:
1565 		switch (mgmt->u.action.u.addba_req.action_code) {
1566 		case WLAN_ACTION_ADDBA_REQ:
1567 			if (len < (IEEE80211_MIN_ACTION_SIZE +
1568 				   sizeof(mgmt->u.action.u.addba_req)))
1569 				return RX_DROP_MONITOR;
1570 			ieee80211_process_addba_request(local, rx->sta, mgmt, len);
1571 			break;
1572 		case WLAN_ACTION_ADDBA_RESP:
1573 			if (len < (IEEE80211_MIN_ACTION_SIZE +
1574 				   sizeof(mgmt->u.action.u.addba_resp)))
1575 				return RX_DROP_MONITOR;
1576 			ieee80211_process_addba_resp(local, rx->sta, mgmt, len);
1577 			break;
1578 		case WLAN_ACTION_DELBA:
1579 			if (len < (IEEE80211_MIN_ACTION_SIZE +
1580 				   sizeof(mgmt->u.action.u.delba)))
1581 				return RX_DROP_MONITOR;
1582 			ieee80211_process_delba(sdata, rx->sta, mgmt, len);
1583 			break;
1584 		}
1585 		break;
1586 	case WLAN_CATEGORY_SPECTRUM_MGMT:
1587 		if (local->hw.conf.channel->band != IEEE80211_BAND_5GHZ)
1588 			return RX_DROP_MONITOR;
1589 		switch (mgmt->u.action.u.measurement.action_code) {
1590 		case WLAN_ACTION_SPCT_MSR_REQ:
1591 			if (len < (IEEE80211_MIN_ACTION_SIZE +
1592 				   sizeof(mgmt->u.action.u.measurement)))
1593 				return RX_DROP_MONITOR;
1594 			ieee80211_process_measurement_req(sdata, mgmt, len);
1595 			break;
1596 		}
1597 		break;
1598 	default:
1599 		return RX_CONTINUE;
1600 	}
1601 
1602 	rx->sta->rx_packets++;
1603 	dev_kfree_skb(rx->skb);
1604 	return RX_QUEUED;
1605 }
1606 
1607 static ieee80211_rx_result debug_noinline
1608 ieee80211_rx_h_mgmt(struct ieee80211_rx_data *rx)
1609 {
1610 	struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(rx->dev);
1611 
1612 	if (!(rx->flags & IEEE80211_RX_RA_MATCH))
1613 		return RX_DROP_MONITOR;
1614 
1615 	if (ieee80211_vif_is_mesh(&sdata->vif))
1616 		return ieee80211_mesh_rx_mgmt(sdata, rx->skb, rx->status);
1617 
1618 	if (sdata->vif.type != NL80211_IFTYPE_STATION &&
1619 	    sdata->vif.type != NL80211_IFTYPE_ADHOC)
1620 		return RX_DROP_MONITOR;
1621 
1622 	if (sdata->flags & IEEE80211_SDATA_USERSPACE_MLME)
1623 		return RX_DROP_MONITOR;
1624 
1625 	ieee80211_sta_rx_mgmt(sdata, rx->skb, rx->status);
1626 	return RX_QUEUED;
1627 }
1628 
1629 static void ieee80211_rx_michael_mic_report(struct net_device *dev,
1630 					    struct ieee80211_hdr *hdr,
1631 					    struct ieee80211_rx_data *rx)
1632 {
1633 	int keyidx;
1634 	unsigned int hdrlen;
1635 	DECLARE_MAC_BUF(mac);
1636 	DECLARE_MAC_BUF(mac2);
1637 
1638 	hdrlen = ieee80211_hdrlen(hdr->frame_control);
1639 	if (rx->skb->len >= hdrlen + 4)
1640 		keyidx = rx->skb->data[hdrlen + 3] >> 6;
1641 	else
1642 		keyidx = -1;
1643 
1644 	if (!rx->sta) {
1645 		/*
1646 		 * Some hardware seem to generate incorrect Michael MIC
1647 		 * reports; ignore them to avoid triggering countermeasures.
1648 		 */
1649 		goto ignore;
1650 	}
1651 
1652 	if (!ieee80211_has_protected(hdr->frame_control))
1653 		goto ignore;
1654 
1655 	if (rx->sdata->vif.type == NL80211_IFTYPE_AP && keyidx) {
1656 		/*
1657 		 * APs with pairwise keys should never receive Michael MIC
1658 		 * errors for non-zero keyidx because these are reserved for
1659 		 * group keys and only the AP is sending real multicast
1660 		 * frames in the BSS.
1661 		 */
1662 		goto ignore;
1663 	}
1664 
1665 	if (!ieee80211_is_data(hdr->frame_control) &&
1666 	    !ieee80211_is_auth(hdr->frame_control))
1667 		goto ignore;
1668 
1669 	mac80211_ev_michael_mic_failure(rx->sdata, keyidx, hdr);
1670  ignore:
1671 	dev_kfree_skb(rx->skb);
1672 	rx->skb = NULL;
1673 }
1674 
1675 /* TODO: use IEEE80211_RX_FRAGMENTED */
1676 static void ieee80211_rx_cooked_monitor(struct ieee80211_rx_data *rx)
1677 {
1678 	struct ieee80211_sub_if_data *sdata;
1679 	struct ieee80211_local *local = rx->local;
1680 	struct ieee80211_rtap_hdr {
1681 		struct ieee80211_radiotap_header hdr;
1682 		u8 flags;
1683 		u8 rate;
1684 		__le16 chan_freq;
1685 		__le16 chan_flags;
1686 	} __attribute__ ((packed)) *rthdr;
1687 	struct sk_buff *skb = rx->skb, *skb2;
1688 	struct net_device *prev_dev = NULL;
1689 	struct ieee80211_rx_status *status = rx->status;
1690 
1691 	if (rx->flags & IEEE80211_RX_CMNTR_REPORTED)
1692 		goto out_free_skb;
1693 
1694 	if (skb_headroom(skb) < sizeof(*rthdr) &&
1695 	    pskb_expand_head(skb, sizeof(*rthdr), 0, GFP_ATOMIC))
1696 		goto out_free_skb;
1697 
1698 	rthdr = (void *)skb_push(skb, sizeof(*rthdr));
1699 	memset(rthdr, 0, sizeof(*rthdr));
1700 	rthdr->hdr.it_len = cpu_to_le16(sizeof(*rthdr));
1701 	rthdr->hdr.it_present =
1702 		cpu_to_le32((1 << IEEE80211_RADIOTAP_FLAGS) |
1703 			    (1 << IEEE80211_RADIOTAP_RATE) |
1704 			    (1 << IEEE80211_RADIOTAP_CHANNEL));
1705 
1706 	rthdr->rate = rx->rate->bitrate / 5;
1707 	rthdr->chan_freq = cpu_to_le16(status->freq);
1708 
1709 	if (status->band == IEEE80211_BAND_5GHZ)
1710 		rthdr->chan_flags = cpu_to_le16(IEEE80211_CHAN_OFDM |
1711 						IEEE80211_CHAN_5GHZ);
1712 	else
1713 		rthdr->chan_flags = cpu_to_le16(IEEE80211_CHAN_DYN |
1714 						IEEE80211_CHAN_2GHZ);
1715 
1716 	skb_set_mac_header(skb, 0);
1717 	skb->ip_summed = CHECKSUM_UNNECESSARY;
1718 	skb->pkt_type = PACKET_OTHERHOST;
1719 	skb->protocol = htons(ETH_P_802_2);
1720 
1721 	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
1722 		if (!netif_running(sdata->dev))
1723 			continue;
1724 
1725 		if (sdata->vif.type != NL80211_IFTYPE_MONITOR ||
1726 		    !(sdata->u.mntr_flags & MONITOR_FLAG_COOK_FRAMES))
1727 			continue;
1728 
1729 		if (prev_dev) {
1730 			skb2 = skb_clone(skb, GFP_ATOMIC);
1731 			if (skb2) {
1732 				skb2->dev = prev_dev;
1733 				netif_rx(skb2);
1734 			}
1735 		}
1736 
1737 		prev_dev = sdata->dev;
1738 		sdata->dev->stats.rx_packets++;
1739 		sdata->dev->stats.rx_bytes += skb->len;
1740 	}
1741 
1742 	if (prev_dev) {
1743 		skb->dev = prev_dev;
1744 		netif_rx(skb);
1745 		skb = NULL;
1746 	} else
1747 		goto out_free_skb;
1748 
1749 	rx->flags |= IEEE80211_RX_CMNTR_REPORTED;
1750 	return;
1751 
1752  out_free_skb:
1753 	dev_kfree_skb(skb);
1754 }
1755 
1756 
1757 static void ieee80211_invoke_rx_handlers(struct ieee80211_sub_if_data *sdata,
1758 					 struct ieee80211_rx_data *rx,
1759 					 struct sk_buff *skb)
1760 {
1761 	ieee80211_rx_result res = RX_DROP_MONITOR;
1762 
1763 	rx->skb = skb;
1764 	rx->sdata = sdata;
1765 	rx->dev = sdata->dev;
1766 
1767 #define CALL_RXH(rxh)			\
1768 	do {				\
1769 		res = rxh(rx);		\
1770 		if (res != RX_CONTINUE)	\
1771 			goto rxh_done;  \
1772 	} while (0);
1773 
1774 	CALL_RXH(ieee80211_rx_h_passive_scan)
1775 	CALL_RXH(ieee80211_rx_h_check)
1776 	CALL_RXH(ieee80211_rx_h_decrypt)
1777 	CALL_RXH(ieee80211_rx_h_sta_process)
1778 	CALL_RXH(ieee80211_rx_h_defragment)
1779 	CALL_RXH(ieee80211_rx_h_ps_poll)
1780 	CALL_RXH(ieee80211_rx_h_michael_mic_verify)
1781 	/* must be after MMIC verify so header is counted in MPDU mic */
1782 	CALL_RXH(ieee80211_rx_h_remove_qos_control)
1783 	CALL_RXH(ieee80211_rx_h_amsdu)
1784 #ifdef CONFIG_MAC80211_MESH
1785 	if (ieee80211_vif_is_mesh(&sdata->vif))
1786 		CALL_RXH(ieee80211_rx_h_mesh_fwding);
1787 #endif
1788 	CALL_RXH(ieee80211_rx_h_data)
1789 	CALL_RXH(ieee80211_rx_h_ctrl)
1790 	CALL_RXH(ieee80211_rx_h_action)
1791 	CALL_RXH(ieee80211_rx_h_mgmt)
1792 
1793 #undef CALL_RXH
1794 
1795  rxh_done:
1796 	switch (res) {
1797 	case RX_DROP_MONITOR:
1798 		I802_DEBUG_INC(sdata->local->rx_handlers_drop);
1799 		if (rx->sta)
1800 			rx->sta->rx_dropped++;
1801 		/* fall through */
1802 	case RX_CONTINUE:
1803 		ieee80211_rx_cooked_monitor(rx);
1804 		break;
1805 	case RX_DROP_UNUSABLE:
1806 		I802_DEBUG_INC(sdata->local->rx_handlers_drop);
1807 		if (rx->sta)
1808 			rx->sta->rx_dropped++;
1809 		dev_kfree_skb(rx->skb);
1810 		break;
1811 	case RX_QUEUED:
1812 		I802_DEBUG_INC(sdata->local->rx_handlers_queued);
1813 		break;
1814 	}
1815 }
1816 
1817 /* main receive path */
1818 
1819 static int prepare_for_handlers(struct ieee80211_sub_if_data *sdata,
1820 				u8 *bssid, struct ieee80211_rx_data *rx,
1821 				struct ieee80211_hdr *hdr)
1822 {
1823 	int multicast = is_multicast_ether_addr(hdr->addr1);
1824 
1825 	switch (sdata->vif.type) {
1826 	case NL80211_IFTYPE_STATION:
1827 		if (!bssid)
1828 			return 0;
1829 		if (!ieee80211_bssid_match(bssid, sdata->u.sta.bssid)) {
1830 			if (!(rx->flags & IEEE80211_RX_IN_SCAN))
1831 				return 0;
1832 			rx->flags &= ~IEEE80211_RX_RA_MATCH;
1833 		} else if (!multicast &&
1834 			   compare_ether_addr(sdata->dev->dev_addr,
1835 					      hdr->addr1) != 0) {
1836 			if (!(sdata->dev->flags & IFF_PROMISC))
1837 				return 0;
1838 			rx->flags &= ~IEEE80211_RX_RA_MATCH;
1839 		}
1840 		break;
1841 	case NL80211_IFTYPE_ADHOC:
1842 		if (!bssid)
1843 			return 0;
1844 		if (ieee80211_is_beacon(hdr->frame_control)) {
1845 			return 1;
1846 		}
1847 		else if (!ieee80211_bssid_match(bssid, sdata->u.sta.bssid)) {
1848 			if (!(rx->flags & IEEE80211_RX_IN_SCAN))
1849 				return 0;
1850 			rx->flags &= ~IEEE80211_RX_RA_MATCH;
1851 		} else if (!multicast &&
1852 			   compare_ether_addr(sdata->dev->dev_addr,
1853 					      hdr->addr1) != 0) {
1854 			if (!(sdata->dev->flags & IFF_PROMISC))
1855 				return 0;
1856 			rx->flags &= ~IEEE80211_RX_RA_MATCH;
1857 		} else if (!rx->sta)
1858 			rx->sta = ieee80211_ibss_add_sta(sdata, rx->skb,
1859 						bssid, hdr->addr2,
1860 						BIT(rx->status->rate_idx));
1861 		break;
1862 	case NL80211_IFTYPE_MESH_POINT:
1863 		if (!multicast &&
1864 		    compare_ether_addr(sdata->dev->dev_addr,
1865 				       hdr->addr1) != 0) {
1866 			if (!(sdata->dev->flags & IFF_PROMISC))
1867 				return 0;
1868 
1869 			rx->flags &= ~IEEE80211_RX_RA_MATCH;
1870 		}
1871 		break;
1872 	case NL80211_IFTYPE_AP_VLAN:
1873 	case NL80211_IFTYPE_AP:
1874 		if (!bssid) {
1875 			if (compare_ether_addr(sdata->dev->dev_addr,
1876 					       hdr->addr1))
1877 				return 0;
1878 		} else if (!ieee80211_bssid_match(bssid,
1879 					sdata->dev->dev_addr)) {
1880 			if (!(rx->flags & IEEE80211_RX_IN_SCAN))
1881 				return 0;
1882 			rx->flags &= ~IEEE80211_RX_RA_MATCH;
1883 		}
1884 		break;
1885 	case NL80211_IFTYPE_WDS:
1886 		if (bssid || !ieee80211_is_data(hdr->frame_control))
1887 			return 0;
1888 		if (compare_ether_addr(sdata->u.wds.remote_addr, hdr->addr2))
1889 			return 0;
1890 		break;
1891 	case NL80211_IFTYPE_MONITOR:
1892 		/* take everything */
1893 		break;
1894 	case NL80211_IFTYPE_UNSPECIFIED:
1895 	case __NL80211_IFTYPE_AFTER_LAST:
1896 		/* should never get here */
1897 		WARN_ON(1);
1898 		break;
1899 	}
1900 
1901 	return 1;
1902 }
1903 
1904 /*
1905  * This is the actual Rx frames handler. as it blongs to Rx path it must
1906  * be called with rcu_read_lock protection.
1907  */
1908 static void __ieee80211_rx_handle_packet(struct ieee80211_hw *hw,
1909 					 struct sk_buff *skb,
1910 					 struct ieee80211_rx_status *status,
1911 					 struct ieee80211_rate *rate)
1912 {
1913 	struct ieee80211_local *local = hw_to_local(hw);
1914 	struct ieee80211_sub_if_data *sdata;
1915 	struct ieee80211_hdr *hdr;
1916 	struct ieee80211_rx_data rx;
1917 	int prepares;
1918 	struct ieee80211_sub_if_data *prev = NULL;
1919 	struct sk_buff *skb_new;
1920 	u8 *bssid;
1921 
1922 	hdr = (struct ieee80211_hdr *)skb->data;
1923 	memset(&rx, 0, sizeof(rx));
1924 	rx.skb = skb;
1925 	rx.local = local;
1926 
1927 	rx.status = status;
1928 	rx.rate = rate;
1929 
1930 	if (ieee80211_is_data(hdr->frame_control) || ieee80211_is_mgmt(hdr->frame_control))
1931 		local->dot11ReceivedFragmentCount++;
1932 
1933 	rx.sta = sta_info_get(local, hdr->addr2);
1934 	if (rx.sta) {
1935 		rx.sdata = rx.sta->sdata;
1936 		rx.dev = rx.sta->sdata->dev;
1937 	}
1938 
1939 	if ((status->flag & RX_FLAG_MMIC_ERROR)) {
1940 		ieee80211_rx_michael_mic_report(local->mdev, hdr, &rx);
1941 		return;
1942 	}
1943 
1944 	if (unlikely(local->sw_scanning || local->hw_scanning))
1945 		rx.flags |= IEEE80211_RX_IN_SCAN;
1946 
1947 	ieee80211_parse_qos(&rx);
1948 	ieee80211_verify_ip_alignment(&rx);
1949 
1950 	skb = rx.skb;
1951 
1952 	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
1953 		if (!netif_running(sdata->dev))
1954 			continue;
1955 
1956 		if (sdata->vif.type == NL80211_IFTYPE_MONITOR)
1957 			continue;
1958 
1959 		bssid = ieee80211_get_bssid(hdr, skb->len, sdata->vif.type);
1960 		rx.flags |= IEEE80211_RX_RA_MATCH;
1961 		prepares = prepare_for_handlers(sdata, bssid, &rx, hdr);
1962 
1963 		if (!prepares)
1964 			continue;
1965 
1966 		/*
1967 		 * frame is destined for this interface, but if it's not
1968 		 * also for the previous one we handle that after the
1969 		 * loop to avoid copying the SKB once too much
1970 		 */
1971 
1972 		if (!prev) {
1973 			prev = sdata;
1974 			continue;
1975 		}
1976 
1977 		/*
1978 		 * frame was destined for the previous interface
1979 		 * so invoke RX handlers for it
1980 		 */
1981 
1982 		skb_new = skb_copy(skb, GFP_ATOMIC);
1983 		if (!skb_new) {
1984 			if (net_ratelimit())
1985 				printk(KERN_DEBUG "%s: failed to copy "
1986 				       "multicast frame for %s\n",
1987 				       wiphy_name(local->hw.wiphy),
1988 				       prev->dev->name);
1989 			continue;
1990 		}
1991 		ieee80211_invoke_rx_handlers(prev, &rx, skb_new);
1992 		prev = sdata;
1993 	}
1994 	if (prev)
1995 		ieee80211_invoke_rx_handlers(prev, &rx, skb);
1996 	else
1997 		dev_kfree_skb(skb);
1998 }
1999 
2000 #define SEQ_MODULO 0x1000
2001 #define SEQ_MASK   0xfff
2002 
2003 static inline int seq_less(u16 sq1, u16 sq2)
2004 {
2005 	return (((sq1 - sq2) & SEQ_MASK) > (SEQ_MODULO >> 1));
2006 }
2007 
2008 static inline u16 seq_inc(u16 sq)
2009 {
2010 	return ((sq + 1) & SEQ_MASK);
2011 }
2012 
2013 static inline u16 seq_sub(u16 sq1, u16 sq2)
2014 {
2015 	return ((sq1 - sq2) & SEQ_MASK);
2016 }
2017 
2018 
2019 /*
2020  * As it function blongs to Rx path it must be called with
2021  * the proper rcu_read_lock protection for its flow.
2022  */
2023 u8 ieee80211_sta_manage_reorder_buf(struct ieee80211_hw *hw,
2024 				struct tid_ampdu_rx *tid_agg_rx,
2025 				struct sk_buff *skb, u16 mpdu_seq_num,
2026 				int bar_req)
2027 {
2028 	struct ieee80211_local *local = hw_to_local(hw);
2029 	struct ieee80211_rx_status status;
2030 	u16 head_seq_num, buf_size;
2031 	int index;
2032 	struct ieee80211_supported_band *sband;
2033 	struct ieee80211_rate *rate;
2034 
2035 	buf_size = tid_agg_rx->buf_size;
2036 	head_seq_num = tid_agg_rx->head_seq_num;
2037 
2038 	/* frame with out of date sequence number */
2039 	if (seq_less(mpdu_seq_num, head_seq_num)) {
2040 		dev_kfree_skb(skb);
2041 		return 1;
2042 	}
2043 
2044 	/* if frame sequence number exceeds our buffering window size or
2045 	 * block Ack Request arrived - release stored frames */
2046 	if ((!seq_less(mpdu_seq_num, head_seq_num + buf_size)) || (bar_req)) {
2047 		/* new head to the ordering buffer */
2048 		if (bar_req)
2049 			head_seq_num = mpdu_seq_num;
2050 		else
2051 			head_seq_num =
2052 				seq_inc(seq_sub(mpdu_seq_num, buf_size));
2053 		/* release stored frames up to new head to stack */
2054 		while (seq_less(tid_agg_rx->head_seq_num, head_seq_num)) {
2055 			index = seq_sub(tid_agg_rx->head_seq_num,
2056 				tid_agg_rx->ssn)
2057 				% tid_agg_rx->buf_size;
2058 
2059 			if (tid_agg_rx->reorder_buf[index]) {
2060 				/* release the reordered frames to stack */
2061 				memcpy(&status,
2062 					tid_agg_rx->reorder_buf[index]->cb,
2063 					sizeof(status));
2064 				sband = local->hw.wiphy->bands[status.band];
2065 				rate = &sband->bitrates[status.rate_idx];
2066 				__ieee80211_rx_handle_packet(hw,
2067 					tid_agg_rx->reorder_buf[index],
2068 					&status, rate);
2069 				tid_agg_rx->stored_mpdu_num--;
2070 				tid_agg_rx->reorder_buf[index] = NULL;
2071 			}
2072 			tid_agg_rx->head_seq_num =
2073 				seq_inc(tid_agg_rx->head_seq_num);
2074 		}
2075 		if (bar_req)
2076 			return 1;
2077 	}
2078 
2079 	/* now the new frame is always in the range of the reordering */
2080 	/* buffer window */
2081 	index = seq_sub(mpdu_seq_num, tid_agg_rx->ssn)
2082 				% tid_agg_rx->buf_size;
2083 	/* check if we already stored this frame */
2084 	if (tid_agg_rx->reorder_buf[index]) {
2085 		dev_kfree_skb(skb);
2086 		return 1;
2087 	}
2088 
2089 	/* if arrived mpdu is in the right order and nothing else stored */
2090 	/* release it immediately */
2091 	if (mpdu_seq_num == tid_agg_rx->head_seq_num &&
2092 			tid_agg_rx->stored_mpdu_num == 0) {
2093 		tid_agg_rx->head_seq_num =
2094 			seq_inc(tid_agg_rx->head_seq_num);
2095 		return 0;
2096 	}
2097 
2098 	/* put the frame in the reordering buffer */
2099 	tid_agg_rx->reorder_buf[index] = skb;
2100 	tid_agg_rx->stored_mpdu_num++;
2101 	/* release the buffer until next missing frame */
2102 	index = seq_sub(tid_agg_rx->head_seq_num, tid_agg_rx->ssn)
2103 						% tid_agg_rx->buf_size;
2104 	while (tid_agg_rx->reorder_buf[index]) {
2105 		/* release the reordered frame back to stack */
2106 		memcpy(&status, tid_agg_rx->reorder_buf[index]->cb,
2107 			sizeof(status));
2108 		sband = local->hw.wiphy->bands[status.band];
2109 		rate = &sband->bitrates[status.rate_idx];
2110 		__ieee80211_rx_handle_packet(hw, tid_agg_rx->reorder_buf[index],
2111 					     &status, rate);
2112 		tid_agg_rx->stored_mpdu_num--;
2113 		tid_agg_rx->reorder_buf[index] = NULL;
2114 		tid_agg_rx->head_seq_num = seq_inc(tid_agg_rx->head_seq_num);
2115 		index =	seq_sub(tid_agg_rx->head_seq_num,
2116 			tid_agg_rx->ssn) % tid_agg_rx->buf_size;
2117 	}
2118 	return 1;
2119 }
2120 
2121 static u8 ieee80211_rx_reorder_ampdu(struct ieee80211_local *local,
2122 				     struct sk_buff *skb)
2123 {
2124 	struct ieee80211_hw *hw = &local->hw;
2125 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
2126 	struct sta_info *sta;
2127 	struct tid_ampdu_rx *tid_agg_rx;
2128 	u16 sc;
2129 	u16 mpdu_seq_num;
2130 	u8 ret = 0;
2131 	int tid;
2132 
2133 	sta = sta_info_get(local, hdr->addr2);
2134 	if (!sta)
2135 		return ret;
2136 
2137 	/* filter the QoS data rx stream according to
2138 	 * STA/TID and check if this STA/TID is on aggregation */
2139 	if (!ieee80211_is_data_qos(hdr->frame_control))
2140 		goto end_reorder;
2141 
2142 	tid = *ieee80211_get_qos_ctl(hdr) & IEEE80211_QOS_CTL_TID_MASK;
2143 
2144 	if (sta->ampdu_mlme.tid_state_rx[tid] != HT_AGG_STATE_OPERATIONAL)
2145 		goto end_reorder;
2146 
2147 	tid_agg_rx = sta->ampdu_mlme.tid_rx[tid];
2148 
2149 	/* qos null data frames are excluded */
2150 	if (unlikely(hdr->frame_control & cpu_to_le16(IEEE80211_STYPE_NULLFUNC)))
2151 		goto end_reorder;
2152 
2153 	/* new un-ordered ampdu frame - process it */
2154 
2155 	/* reset session timer */
2156 	if (tid_agg_rx->timeout) {
2157 		unsigned long expires =
2158 			jiffies + (tid_agg_rx->timeout / 1000) * HZ;
2159 		mod_timer(&tid_agg_rx->session_timer, expires);
2160 	}
2161 
2162 	/* if this mpdu is fragmented - terminate rx aggregation session */
2163 	sc = le16_to_cpu(hdr->seq_ctrl);
2164 	if (sc & IEEE80211_SCTL_FRAG) {
2165 		ieee80211_sta_stop_rx_ba_session(sta->sdata, sta->sta.addr,
2166 			tid, 0, WLAN_REASON_QSTA_REQUIRE_SETUP);
2167 		ret = 1;
2168 		goto end_reorder;
2169 	}
2170 
2171 	/* according to mpdu sequence number deal with reordering buffer */
2172 	mpdu_seq_num = (sc & IEEE80211_SCTL_SEQ) >> 4;
2173 	ret = ieee80211_sta_manage_reorder_buf(hw, tid_agg_rx, skb,
2174 						mpdu_seq_num, 0);
2175  end_reorder:
2176 	return ret;
2177 }
2178 
2179 /*
2180  * This is the receive path handler. It is called by a low level driver when an
2181  * 802.11 MPDU is received from the hardware.
2182  */
2183 void __ieee80211_rx(struct ieee80211_hw *hw, struct sk_buff *skb,
2184 		    struct ieee80211_rx_status *status)
2185 {
2186 	struct ieee80211_local *local = hw_to_local(hw);
2187 	struct ieee80211_rate *rate = NULL;
2188 	struct ieee80211_supported_band *sband;
2189 
2190 	if (status->band < 0 ||
2191 	    status->band >= IEEE80211_NUM_BANDS) {
2192 		WARN_ON(1);
2193 		return;
2194 	}
2195 
2196 	sband = local->hw.wiphy->bands[status->band];
2197 
2198 	if (!sband ||
2199 	    status->rate_idx < 0 ||
2200 	    status->rate_idx >= sband->n_bitrates) {
2201 		WARN_ON(1);
2202 		return;
2203 	}
2204 
2205 	rate = &sband->bitrates[status->rate_idx];
2206 
2207 	/*
2208 	 * key references and virtual interfaces are protected using RCU
2209 	 * and this requires that we are in a read-side RCU section during
2210 	 * receive processing
2211 	 */
2212 	rcu_read_lock();
2213 
2214 	/*
2215 	 * Frames with failed FCS/PLCP checksum are not returned,
2216 	 * all other frames are returned without radiotap header
2217 	 * if it was previously present.
2218 	 * Also, frames with less than 16 bytes are dropped.
2219 	 */
2220 	skb = ieee80211_rx_monitor(local, skb, status, rate);
2221 	if (!skb) {
2222 		rcu_read_unlock();
2223 		return;
2224 	}
2225 
2226 	if (!ieee80211_rx_reorder_ampdu(local, skb))
2227 		__ieee80211_rx_handle_packet(hw, skb, status, rate);
2228 
2229 	rcu_read_unlock();
2230 }
2231 EXPORT_SYMBOL(__ieee80211_rx);
2232 
2233 /* This is a version of the rx handler that can be called from hard irq
2234  * context. Post the skb on the queue and schedule the tasklet */
2235 void ieee80211_rx_irqsafe(struct ieee80211_hw *hw, struct sk_buff *skb,
2236 			  struct ieee80211_rx_status *status)
2237 {
2238 	struct ieee80211_local *local = hw_to_local(hw);
2239 
2240 	BUILD_BUG_ON(sizeof(struct ieee80211_rx_status) > sizeof(skb->cb));
2241 
2242 	skb->dev = local->mdev;
2243 	/* copy status into skb->cb for use by tasklet */
2244 	memcpy(skb->cb, status, sizeof(*status));
2245 	skb->pkt_type = IEEE80211_RX_MSG;
2246 	skb_queue_tail(&local->skb_queue, skb);
2247 	tasklet_schedule(&local->tasklet);
2248 }
2249 EXPORT_SYMBOL(ieee80211_rx_irqsafe);
2250