xref: /linux/net/mac80211/rx.c (revision 40d3057ac036f2501c1930728a6179be4fca577b)
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 	pos++;
147 
148 	/* IEEE80211_RADIOTAP_RATE */
149 	*pos = rate->bitrate / 5;
150 	pos++;
151 
152 	/* IEEE80211_RADIOTAP_CHANNEL */
153 	*(__le16 *)pos = cpu_to_le16(status->freq);
154 	pos += 2;
155 	if (status->band == IEEE80211_BAND_5GHZ)
156 		*(__le16 *)pos = cpu_to_le16(IEEE80211_CHAN_OFDM |
157 					     IEEE80211_CHAN_5GHZ);
158 	else
159 		*(__le16 *)pos = cpu_to_le16(IEEE80211_CHAN_DYN |
160 					     IEEE80211_CHAN_2GHZ);
161 	pos += 2;
162 
163 	/* IEEE80211_RADIOTAP_DBM_ANTSIGNAL */
164 	if (local->hw.flags & IEEE80211_HW_SIGNAL_DBM) {
165 		*pos = status->signal;
166 		rthdr->it_present |=
167 			cpu_to_le32(1 << IEEE80211_RADIOTAP_DBM_ANTSIGNAL);
168 		pos++;
169 	}
170 
171 	/* IEEE80211_RADIOTAP_DBM_ANTNOISE */
172 	if (local->hw.flags & IEEE80211_HW_NOISE_DBM) {
173 		*pos = status->noise;
174 		rthdr->it_present |=
175 			cpu_to_le32(1 << IEEE80211_RADIOTAP_DBM_ANTNOISE);
176 		pos++;
177 	}
178 
179 	/* IEEE80211_RADIOTAP_LOCK_QUALITY is missing */
180 
181 	/* IEEE80211_RADIOTAP_ANTENNA */
182 	*pos = status->antenna;
183 	pos++;
184 
185 	/* IEEE80211_RADIOTAP_DB_ANTSIGNAL */
186 	if (local->hw.flags & IEEE80211_HW_SIGNAL_DB) {
187 		*pos = status->signal;
188 		rthdr->it_present |=
189 			cpu_to_le32(1 << IEEE80211_RADIOTAP_DB_ANTSIGNAL);
190 		pos++;
191 	}
192 
193 	/* IEEE80211_RADIOTAP_DB_ANTNOISE is not used */
194 
195 	/* IEEE80211_RADIOTAP_RX_FLAGS */
196 	/* ensure 2 byte alignment for the 2 byte field as required */
197 	if ((pos - (unsigned char *)rthdr) & 1)
198 		pos++;
199 	/* FIXME: when radiotap gets a 'bad PLCP' flag use it here */
200 	if (status->flag & (RX_FLAG_FAILED_FCS_CRC | RX_FLAG_FAILED_PLCP_CRC))
201 		*(__le16 *)pos |= cpu_to_le16(IEEE80211_RADIOTAP_F_RX_BADFCS);
202 	pos += 2;
203 }
204 
205 /*
206  * This function copies a received frame to all monitor interfaces and
207  * returns a cleaned-up SKB that no longer includes the FCS nor the
208  * radiotap header the driver might have added.
209  */
210 static struct sk_buff *
211 ieee80211_rx_monitor(struct ieee80211_local *local, struct sk_buff *origskb,
212 		     struct ieee80211_rx_status *status,
213 		     struct ieee80211_rate *rate)
214 {
215 	struct ieee80211_sub_if_data *sdata;
216 	int needed_headroom = 0;
217 	struct sk_buff *skb, *skb2;
218 	struct net_device *prev_dev = NULL;
219 	int present_fcs_len = 0;
220 	int rtap_len = 0;
221 
222 	/*
223 	 * First, we may need to make a copy of the skb because
224 	 *  (1) we need to modify it for radiotap (if not present), and
225 	 *  (2) the other RX handlers will modify the skb we got.
226 	 *
227 	 * We don't need to, of course, if we aren't going to return
228 	 * the SKB because it has a bad FCS/PLCP checksum.
229 	 */
230 	if (status->flag & RX_FLAG_RADIOTAP)
231 		rtap_len = ieee80211_get_radiotap_len(origskb->data);
232 	else
233 		/* room for the radiotap header based on driver features */
234 		needed_headroom = ieee80211_rx_radiotap_len(local, status);
235 
236 	if (local->hw.flags & IEEE80211_HW_RX_INCLUDES_FCS)
237 		present_fcs_len = FCS_LEN;
238 
239 	if (!local->monitors) {
240 		if (should_drop_frame(status, origskb, present_fcs_len,
241 				      rtap_len)) {
242 			dev_kfree_skb(origskb);
243 			return NULL;
244 		}
245 
246 		return remove_monitor_info(local, origskb, rtap_len);
247 	}
248 
249 	if (should_drop_frame(status, origskb, present_fcs_len, rtap_len)) {
250 		/* only need to expand headroom if necessary */
251 		skb = origskb;
252 		origskb = NULL;
253 
254 		/*
255 		 * This shouldn't trigger often because most devices have an
256 		 * RX header they pull before we get here, and that should
257 		 * be big enough for our radiotap information. We should
258 		 * probably export the length to drivers so that we can have
259 		 * them allocate enough headroom to start with.
260 		 */
261 		if (skb_headroom(skb) < needed_headroom &&
262 		    pskb_expand_head(skb, needed_headroom, 0, GFP_ATOMIC)) {
263 			dev_kfree_skb(skb);
264 			return NULL;
265 		}
266 	} else {
267 		/*
268 		 * Need to make a copy and possibly remove radiotap header
269 		 * and FCS from the original.
270 		 */
271 		skb = skb_copy_expand(origskb, needed_headroom, 0, GFP_ATOMIC);
272 
273 		origskb = remove_monitor_info(local, origskb, rtap_len);
274 
275 		if (!skb)
276 			return origskb;
277 	}
278 
279 	/* if necessary, prepend radiotap information */
280 	if (!(status->flag & RX_FLAG_RADIOTAP))
281 		ieee80211_add_rx_radiotap_header(local, skb, status, rate,
282 						 needed_headroom);
283 
284 	skb_reset_mac_header(skb);
285 	skb->ip_summed = CHECKSUM_UNNECESSARY;
286 	skb->pkt_type = PACKET_OTHERHOST;
287 	skb->protocol = htons(ETH_P_802_2);
288 
289 	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
290 		if (!netif_running(sdata->dev))
291 			continue;
292 
293 		if (sdata->vif.type != IEEE80211_IF_TYPE_MNTR)
294 			continue;
295 
296 		if (sdata->u.mntr_flags & MONITOR_FLAG_COOK_FRAMES)
297 			continue;
298 
299 		if (prev_dev) {
300 			skb2 = skb_clone(skb, GFP_ATOMIC);
301 			if (skb2) {
302 				skb2->dev = prev_dev;
303 				netif_rx(skb2);
304 			}
305 		}
306 
307 		prev_dev = sdata->dev;
308 		sdata->dev->stats.rx_packets++;
309 		sdata->dev->stats.rx_bytes += skb->len;
310 	}
311 
312 	if (prev_dev) {
313 		skb->dev = prev_dev;
314 		netif_rx(skb);
315 	} else
316 		dev_kfree_skb(skb);
317 
318 	return origskb;
319 }
320 
321 
322 static void ieee80211_parse_qos(struct ieee80211_rx_data *rx)
323 {
324 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
325 	int tid;
326 
327 	/* does the frame have a qos control field? */
328 	if (ieee80211_is_data_qos(hdr->frame_control)) {
329 		u8 *qc = ieee80211_get_qos_ctl(hdr);
330 		/* frame has qos control */
331 		tid = *qc & IEEE80211_QOS_CTL_TID_MASK;
332 		if (*qc & IEEE80211_QOS_CONTROL_A_MSDU_PRESENT)
333 			rx->flags |= IEEE80211_RX_AMSDU;
334 		else
335 			rx->flags &= ~IEEE80211_RX_AMSDU;
336 	} else {
337 		/*
338 		 * IEEE 802.11-2007, 7.1.3.4.1 ("Sequence Number field"):
339 		 *
340 		 *	Sequence numbers for management frames, QoS data
341 		 *	frames with a broadcast/multicast address in the
342 		 *	Address 1 field, and all non-QoS data frames sent
343 		 *	by QoS STAs are assigned using an additional single
344 		 *	modulo-4096 counter, [...]
345 		 *
346 		 * We also use that counter for non-QoS STAs.
347 		 */
348 		tid = NUM_RX_DATA_QUEUES - 1;
349 	}
350 
351 	rx->queue = tid;
352 	/* Set skb->priority to 1d tag if highest order bit of TID is not set.
353 	 * For now, set skb->priority to 0 for other cases. */
354 	rx->skb->priority = (tid > 7) ? 0 : tid;
355 }
356 
357 static void ieee80211_verify_ip_alignment(struct ieee80211_rx_data *rx)
358 {
359 #ifdef CONFIG_MAC80211_DEBUG_PACKET_ALIGNMENT
360 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
361 	int hdrlen;
362 
363 	if (!ieee80211_is_data_present(hdr->frame_control))
364 		return;
365 
366 	/*
367 	 * Drivers are required to align the payload data in a way that
368 	 * guarantees that the contained IP header is aligned to a four-
369 	 * byte boundary. In the case of regular frames, this simply means
370 	 * aligning the payload to a four-byte boundary (because either
371 	 * the IP header is directly contained, or IV/RFC1042 headers that
372 	 * have a length divisible by four are in front of it.
373 	 *
374 	 * With A-MSDU frames, however, the payload data address must
375 	 * yield two modulo four because there are 14-byte 802.3 headers
376 	 * within the A-MSDU frames that push the IP header further back
377 	 * to a multiple of four again. Thankfully, the specs were sane
378 	 * enough this time around to require padding each A-MSDU subframe
379 	 * to a length that is a multiple of four.
380 	 *
381 	 * Padding like atheros hardware adds which is inbetween the 802.11
382 	 * header and the payload is not supported, the driver is required
383 	 * to move the 802.11 header further back in that case.
384 	 */
385 	hdrlen = ieee80211_hdrlen(hdr->frame_control);
386 	if (rx->flags & IEEE80211_RX_AMSDU)
387 		hdrlen += ETH_HLEN;
388 	WARN_ON_ONCE(((unsigned long)(rx->skb->data + hdrlen)) & 3);
389 #endif
390 }
391 
392 
393 /* rx handlers */
394 
395 static ieee80211_rx_result debug_noinline
396 ieee80211_rx_h_passive_scan(struct ieee80211_rx_data *rx)
397 {
398 	struct ieee80211_local *local = rx->local;
399 	struct sk_buff *skb = rx->skb;
400 
401 	if (unlikely(local->sta_hw_scanning))
402 		return ieee80211_sta_rx_scan(rx->dev, skb, rx->status);
403 
404 	if (unlikely(local->sta_sw_scanning)) {
405 		/* drop all the other packets during a software scan anyway */
406 		if (ieee80211_sta_rx_scan(rx->dev, skb, rx->status)
407 		    != RX_QUEUED)
408 			dev_kfree_skb(skb);
409 		return RX_QUEUED;
410 	}
411 
412 	if (unlikely(rx->flags & IEEE80211_RX_IN_SCAN)) {
413 		/* scanning finished during invoking of handlers */
414 		I802_DEBUG_INC(local->rx_handlers_drop_passive_scan);
415 		return RX_DROP_UNUSABLE;
416 	}
417 
418 	return RX_CONTINUE;
419 }
420 
421 static ieee80211_rx_result
422 ieee80211_rx_mesh_check(struct ieee80211_rx_data *rx)
423 {
424 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
425 	unsigned int hdrlen = ieee80211_hdrlen(hdr->frame_control);
426 
427 	if (ieee80211_is_data(hdr->frame_control)) {
428 		if (!ieee80211_has_a4(hdr->frame_control))
429 			return RX_DROP_MONITOR;
430 		if (memcmp(hdr->addr4, rx->dev->dev_addr, ETH_ALEN) == 0)
431 			return RX_DROP_MONITOR;
432 	}
433 
434 	/* If there is not an established peer link and this is not a peer link
435 	 * establisment frame, beacon or probe, drop the frame.
436 	 */
437 
438 	if (!rx->sta || sta_plink_state(rx->sta) != PLINK_ESTAB) {
439 		struct ieee80211_mgmt *mgmt;
440 
441 		if (!ieee80211_is_mgmt(hdr->frame_control))
442 			return RX_DROP_MONITOR;
443 
444 		if (ieee80211_is_action(hdr->frame_control)) {
445 			mgmt = (struct ieee80211_mgmt *)hdr;
446 			if (mgmt->u.action.category != PLINK_CATEGORY)
447 				return RX_DROP_MONITOR;
448 			return RX_CONTINUE;
449 		}
450 
451 		if (ieee80211_is_probe_req(hdr->frame_control) ||
452 		    ieee80211_is_probe_resp(hdr->frame_control) ||
453 		    ieee80211_is_beacon(hdr->frame_control))
454 			return RX_CONTINUE;
455 
456 		return RX_DROP_MONITOR;
457 
458 	}
459 
460 #define msh_h_get(h, l) ((struct ieee80211s_hdr *) ((u8 *)h + l))
461 
462 	if (ieee80211_is_data(hdr->frame_control) &&
463 	    is_multicast_ether_addr(hdr->addr1) &&
464 	    mesh_rmc_check(hdr->addr4, msh_h_get(hdr, hdrlen), rx->dev))
465 		return RX_DROP_MONITOR;
466 #undef msh_h_get
467 
468 	return RX_CONTINUE;
469 }
470 
471 
472 static ieee80211_rx_result debug_noinline
473 ieee80211_rx_h_check(struct ieee80211_rx_data *rx)
474 {
475 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
476 
477 	/* Drop duplicate 802.11 retransmissions (IEEE 802.11 Chap. 9.2.9) */
478 	if (rx->sta && !is_multicast_ether_addr(hdr->addr1)) {
479 		if (unlikely(ieee80211_has_retry(hdr->frame_control) &&
480 			     rx->sta->last_seq_ctrl[rx->queue] ==
481 			     hdr->seq_ctrl)) {
482 			if (rx->flags & IEEE80211_RX_RA_MATCH) {
483 				rx->local->dot11FrameDuplicateCount++;
484 				rx->sta->num_duplicates++;
485 			}
486 			return RX_DROP_MONITOR;
487 		} else
488 			rx->sta->last_seq_ctrl[rx->queue] = hdr->seq_ctrl;
489 	}
490 
491 	if (unlikely(rx->skb->len < 16)) {
492 		I802_DEBUG_INC(rx->local->rx_handlers_drop_short);
493 		return RX_DROP_MONITOR;
494 	}
495 
496 	/* Drop disallowed frame classes based on STA auth/assoc state;
497 	 * IEEE 802.11, Chap 5.5.
498 	 *
499 	 * 80211.o does filtering only based on association state, i.e., it
500 	 * drops Class 3 frames from not associated stations. hostapd sends
501 	 * deauth/disassoc frames when needed. In addition, hostapd is
502 	 * responsible for filtering on both auth and assoc states.
503 	 */
504 
505 	if (ieee80211_vif_is_mesh(&rx->sdata->vif))
506 		return ieee80211_rx_mesh_check(rx);
507 
508 	if (unlikely((ieee80211_is_data(hdr->frame_control) ||
509 		      ieee80211_is_pspoll(hdr->frame_control)) &&
510 		     rx->sdata->vif.type != IEEE80211_IF_TYPE_IBSS &&
511 		     (!rx->sta || !test_sta_flags(rx->sta, WLAN_STA_ASSOC)))) {
512 		if ((!ieee80211_has_fromds(hdr->frame_control) &&
513 		     !ieee80211_has_tods(hdr->frame_control) &&
514 		     ieee80211_is_data(hdr->frame_control)) ||
515 		    !(rx->flags & IEEE80211_RX_RA_MATCH)) {
516 			/* Drop IBSS frames and frames for other hosts
517 			 * silently. */
518 			return RX_DROP_MONITOR;
519 		}
520 
521 		return RX_DROP_MONITOR;
522 	}
523 
524 	return RX_CONTINUE;
525 }
526 
527 
528 static ieee80211_rx_result debug_noinline
529 ieee80211_rx_h_decrypt(struct ieee80211_rx_data *rx)
530 {
531 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
532 	int keyidx;
533 	int hdrlen;
534 	ieee80211_rx_result result = RX_DROP_UNUSABLE;
535 	struct ieee80211_key *stakey = NULL;
536 
537 	/*
538 	 * Key selection 101
539 	 *
540 	 * There are three types of keys:
541 	 *  - GTK (group keys)
542 	 *  - PTK (pairwise keys)
543 	 *  - STK (station-to-station pairwise keys)
544 	 *
545 	 * When selecting a key, we have to distinguish between multicast
546 	 * (including broadcast) and unicast frames, the latter can only
547 	 * use PTKs and STKs while the former always use GTKs. Unless, of
548 	 * course, actual WEP keys ("pre-RSNA") are used, then unicast
549 	 * frames can also use key indizes like GTKs. Hence, if we don't
550 	 * have a PTK/STK we check the key index for a WEP key.
551 	 *
552 	 * Note that in a regular BSS, multicast frames are sent by the
553 	 * AP only, associated stations unicast the frame to the AP first
554 	 * which then multicasts it on their behalf.
555 	 *
556 	 * There is also a slight problem in IBSS mode: GTKs are negotiated
557 	 * with each station, that is something we don't currently handle.
558 	 * The spec seems to expect that one negotiates the same key with
559 	 * every station but there's no such requirement; VLANs could be
560 	 * possible.
561 	 */
562 
563 	if (!ieee80211_has_protected(hdr->frame_control))
564 		return RX_CONTINUE;
565 
566 	/*
567 	 * No point in finding a key and decrypting if the frame is neither
568 	 * addressed to us nor a multicast frame.
569 	 */
570 	if (!(rx->flags & IEEE80211_RX_RA_MATCH))
571 		return RX_CONTINUE;
572 
573 	if (rx->sta)
574 		stakey = rcu_dereference(rx->sta->key);
575 
576 	if (!is_multicast_ether_addr(hdr->addr1) && stakey) {
577 		rx->key = stakey;
578 	} else {
579 		/*
580 		 * The device doesn't give us the IV so we won't be
581 		 * able to look up the key. That's ok though, we
582 		 * don't need to decrypt the frame, we just won't
583 		 * be able to keep statistics accurate.
584 		 * Except for key threshold notifications, should
585 		 * we somehow allow the driver to tell us which key
586 		 * the hardware used if this flag is set?
587 		 */
588 		if ((rx->status->flag & RX_FLAG_DECRYPTED) &&
589 		    (rx->status->flag & RX_FLAG_IV_STRIPPED))
590 			return RX_CONTINUE;
591 
592 		hdrlen = ieee80211_hdrlen(hdr->frame_control);
593 
594 		if (rx->skb->len < 8 + hdrlen)
595 			return RX_DROP_UNUSABLE; /* TODO: count this? */
596 
597 		/*
598 		 * no need to call ieee80211_wep_get_keyidx,
599 		 * it verifies a bunch of things we've done already
600 		 */
601 		keyidx = rx->skb->data[hdrlen + 3] >> 6;
602 
603 		rx->key = rcu_dereference(rx->sdata->keys[keyidx]);
604 
605 		/*
606 		 * RSNA-protected unicast frames should always be sent with
607 		 * pairwise or station-to-station keys, but for WEP we allow
608 		 * using a key index as well.
609 		 */
610 		if (rx->key && rx->key->conf.alg != ALG_WEP &&
611 		    !is_multicast_ether_addr(hdr->addr1))
612 			rx->key = NULL;
613 	}
614 
615 	if (rx->key) {
616 		rx->key->tx_rx_count++;
617 		/* TODO: add threshold stuff again */
618 	} else {
619 		return RX_DROP_MONITOR;
620 	}
621 
622 	/* Check for weak IVs if possible */
623 	if (rx->sta && rx->key->conf.alg == ALG_WEP &&
624 	    ieee80211_is_data(hdr->frame_control) &&
625 	    (!(rx->status->flag & RX_FLAG_IV_STRIPPED) ||
626 	     !(rx->status->flag & RX_FLAG_DECRYPTED)) &&
627 	    ieee80211_wep_is_weak_iv(rx->skb, rx->key))
628 		rx->sta->wep_weak_iv_count++;
629 
630 	switch (rx->key->conf.alg) {
631 	case ALG_WEP:
632 		result = ieee80211_crypto_wep_decrypt(rx);
633 		break;
634 	case ALG_TKIP:
635 		result = ieee80211_crypto_tkip_decrypt(rx);
636 		break;
637 	case ALG_CCMP:
638 		result = ieee80211_crypto_ccmp_decrypt(rx);
639 		break;
640 	}
641 
642 	/* either the frame has been decrypted or will be dropped */
643 	rx->status->flag |= RX_FLAG_DECRYPTED;
644 
645 	return result;
646 }
647 
648 static void ap_sta_ps_start(struct net_device *dev, struct sta_info *sta)
649 {
650 	struct ieee80211_sub_if_data *sdata;
651 	DECLARE_MAC_BUF(mac);
652 
653 	sdata = sta->sdata;
654 
655 	atomic_inc(&sdata->bss->num_sta_ps);
656 	set_and_clear_sta_flags(sta, WLAN_STA_PS, WLAN_STA_PSPOLL);
657 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
658 	printk(KERN_DEBUG "%s: STA %s aid %d enters power save mode\n",
659 	       dev->name, print_mac(mac, sta->addr), sta->aid);
660 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
661 }
662 
663 static int ap_sta_ps_end(struct net_device *dev, struct sta_info *sta)
664 {
665 	struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
666 	struct sk_buff *skb;
667 	int sent = 0;
668 	struct ieee80211_sub_if_data *sdata;
669 	struct ieee80211_tx_info *info;
670 	DECLARE_MAC_BUF(mac);
671 
672 	sdata = sta->sdata;
673 
674 	atomic_dec(&sdata->bss->num_sta_ps);
675 
676 	clear_sta_flags(sta, WLAN_STA_PS | WLAN_STA_PSPOLL);
677 
678 	if (!skb_queue_empty(&sta->ps_tx_buf))
679 		sta_info_clear_tim_bit(sta);
680 
681 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
682 	printk(KERN_DEBUG "%s: STA %s aid %d exits power save mode\n",
683 	       dev->name, print_mac(mac, sta->addr), sta->aid);
684 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
685 
686 	/* Send all buffered frames to the station */
687 	while ((skb = skb_dequeue(&sta->tx_filtered)) != NULL) {
688 		info = IEEE80211_SKB_CB(skb);
689 		sent++;
690 		info->flags |= IEEE80211_TX_CTL_REQUEUE;
691 		dev_queue_xmit(skb);
692 	}
693 	while ((skb = skb_dequeue(&sta->ps_tx_buf)) != NULL) {
694 		info = IEEE80211_SKB_CB(skb);
695 		local->total_ps_buffered--;
696 		sent++;
697 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
698 		printk(KERN_DEBUG "%s: STA %s aid %d send PS frame "
699 		       "since STA not sleeping anymore\n", dev->name,
700 		       print_mac(mac, sta->addr), sta->aid);
701 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
702 		info->flags |= IEEE80211_TX_CTL_REQUEUE;
703 		dev_queue_xmit(skb);
704 	}
705 
706 	return sent;
707 }
708 
709 static ieee80211_rx_result debug_noinline
710 ieee80211_rx_h_sta_process(struct ieee80211_rx_data *rx)
711 {
712 	struct sta_info *sta = rx->sta;
713 	struct net_device *dev = rx->dev;
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 == IEEE80211_IF_TYPE_IBSS) {
723 		u8 *bssid = ieee80211_get_bssid(hdr, rx->skb->len,
724 						IEEE80211_IF_TYPE_IBSS);
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 == IEEE80211_IF_TYPE_STA) {
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 == IEEE80211_IF_TYPE_AP ||
750 	     rx->sdata->vif.type == IEEE80211_IF_TYPE_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(dev, sta);
756 		else if (!test_sta_flags(sta, WLAN_STA_PS) &&
757 			 ieee80211_has_pm(hdr->frame_control))
758 			ap_sta_ps_start(dev, 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 			  u16 fc, 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 		u16 f_fc;
829 
830 		idx--;
831 		if (idx < 0)
832 			idx = IEEE80211_FRAGMENT_MAX - 1;
833 
834 		entry = &sdata->fragments[idx];
835 		if (skb_queue_empty(&entry->skb_list) || entry->seq != seq ||
836 		    entry->rx_queue != rx_queue ||
837 		    entry->last_frag + 1 != frag)
838 			continue;
839 
840 		f_hdr = (struct ieee80211_hdr *) entry->skb_list.next->data;
841 		f_fc = le16_to_cpu(f_hdr->frame_control);
842 
843 		if ((fc & IEEE80211_FCTL_FTYPE) != (f_fc & IEEE80211_FCTL_FTYPE) ||
844 		    compare_ether_addr(hdr->addr1, f_hdr->addr1) != 0 ||
845 		    compare_ether_addr(hdr->addr2, f_hdr->addr2) != 0)
846 			continue;
847 
848 		if (time_after(jiffies, entry->first_frag_time + 2 * HZ)) {
849 			__skb_queue_purge(&entry->skb_list);
850 			continue;
851 		}
852 		return entry;
853 	}
854 
855 	return NULL;
856 }
857 
858 static ieee80211_rx_result debug_noinline
859 ieee80211_rx_h_defragment(struct ieee80211_rx_data *rx)
860 {
861 	struct ieee80211_hdr *hdr;
862 	u16 sc;
863 	unsigned int frag, seq;
864 	struct ieee80211_fragment_entry *entry;
865 	struct sk_buff *skb;
866 	DECLARE_MAC_BUF(mac);
867 
868 	hdr = (struct ieee80211_hdr *) rx->skb->data;
869 	sc = le16_to_cpu(hdr->seq_ctrl);
870 	frag = sc & IEEE80211_SCTL_FRAG;
871 
872 	if (likely((!(rx->fc & IEEE80211_FCTL_MOREFRAGS) && frag == 0) ||
873 		   (rx->skb)->len < 24 ||
874 		   is_multicast_ether_addr(hdr->addr1))) {
875 		/* not fragmented */
876 		goto out;
877 	}
878 	I802_DEBUG_INC(rx->local->rx_handlers_fragments);
879 
880 	seq = (sc & IEEE80211_SCTL_SEQ) >> 4;
881 
882 	if (frag == 0) {
883 		/* This is the first fragment of a new frame. */
884 		entry = ieee80211_reassemble_add(rx->sdata, frag, seq,
885 						 rx->queue, &(rx->skb));
886 		if (rx->key && rx->key->conf.alg == ALG_CCMP &&
887 		    (rx->fc & IEEE80211_FCTL_PROTECTED)) {
888 			/* Store CCMP PN so that we can verify that the next
889 			 * fragment has a sequential PN value. */
890 			entry->ccmp = 1;
891 			memcpy(entry->last_pn,
892 			       rx->key->u.ccmp.rx_pn[rx->queue],
893 			       CCMP_PN_LEN);
894 		}
895 		return RX_QUEUED;
896 	}
897 
898 	/* This is a fragment for a frame that should already be pending in
899 	 * fragment cache. Add this fragment to the end of the pending entry.
900 	 */
901 	entry = ieee80211_reassemble_find(rx->sdata, rx->fc, frag, seq,
902 					  rx->queue, hdr);
903 	if (!entry) {
904 		I802_DEBUG_INC(rx->local->rx_handlers_drop_defrag);
905 		return RX_DROP_MONITOR;
906 	}
907 
908 	/* Verify that MPDUs within one MSDU have sequential PN values.
909 	 * (IEEE 802.11i, 8.3.3.4.5) */
910 	if (entry->ccmp) {
911 		int i;
912 		u8 pn[CCMP_PN_LEN], *rpn;
913 		if (!rx->key || rx->key->conf.alg != ALG_CCMP)
914 			return RX_DROP_UNUSABLE;
915 		memcpy(pn, entry->last_pn, CCMP_PN_LEN);
916 		for (i = CCMP_PN_LEN - 1; i >= 0; i--) {
917 			pn[i]++;
918 			if (pn[i])
919 				break;
920 		}
921 		rpn = rx->key->u.ccmp.rx_pn[rx->queue];
922 		if (memcmp(pn, rpn, CCMP_PN_LEN))
923 			return RX_DROP_UNUSABLE;
924 		memcpy(entry->last_pn, pn, CCMP_PN_LEN);
925 	}
926 
927 	skb_pull(rx->skb, ieee80211_get_hdrlen(rx->fc));
928 	__skb_queue_tail(&entry->skb_list, rx->skb);
929 	entry->last_frag = frag;
930 	entry->extra_len += rx->skb->len;
931 	if (rx->fc & IEEE80211_FCTL_MOREFRAGS) {
932 		rx->skb = NULL;
933 		return RX_QUEUED;
934 	}
935 
936 	rx->skb = __skb_dequeue(&entry->skb_list);
937 	if (skb_tailroom(rx->skb) < entry->extra_len) {
938 		I802_DEBUG_INC(rx->local->rx_expand_skb_head2);
939 		if (unlikely(pskb_expand_head(rx->skb, 0, entry->extra_len,
940 					      GFP_ATOMIC))) {
941 			I802_DEBUG_INC(rx->local->rx_handlers_drop_defrag);
942 			__skb_queue_purge(&entry->skb_list);
943 			return RX_DROP_UNUSABLE;
944 		}
945 	}
946 	while ((skb = __skb_dequeue(&entry->skb_list))) {
947 		memcpy(skb_put(rx->skb, skb->len), skb->data, skb->len);
948 		dev_kfree_skb(skb);
949 	}
950 
951 	/* Complete frame has been reassembled - process it now */
952 	rx->flags |= IEEE80211_RX_FRAGMENTED;
953 
954  out:
955 	if (rx->sta)
956 		rx->sta->rx_packets++;
957 	if (is_multicast_ether_addr(hdr->addr1))
958 		rx->local->dot11MulticastReceivedFrameCount++;
959 	else
960 		ieee80211_led_rx(rx->local);
961 	return RX_CONTINUE;
962 }
963 
964 static ieee80211_rx_result debug_noinline
965 ieee80211_rx_h_ps_poll(struct ieee80211_rx_data *rx)
966 {
967 	struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(rx->dev);
968 	struct sk_buff *skb;
969 	int no_pending_pkts;
970 	DECLARE_MAC_BUF(mac);
971 
972 	if (likely(!rx->sta ||
973 		   (rx->fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_CTL ||
974 		   (rx->fc & IEEE80211_FCTL_STYPE) != IEEE80211_STYPE_PSPOLL ||
975 		   !(rx->flags & IEEE80211_RX_RA_MATCH)))
976 		return RX_CONTINUE;
977 
978 	if ((sdata->vif.type != IEEE80211_IF_TYPE_AP) &&
979 	    (sdata->vif.type != IEEE80211_IF_TYPE_VLAN))
980 		return RX_DROP_UNUSABLE;
981 
982 	skb = skb_dequeue(&rx->sta->tx_filtered);
983 	if (!skb) {
984 		skb = skb_dequeue(&rx->sta->ps_tx_buf);
985 		if (skb)
986 			rx->local->total_ps_buffered--;
987 	}
988 	no_pending_pkts = skb_queue_empty(&rx->sta->tx_filtered) &&
989 		skb_queue_empty(&rx->sta->ps_tx_buf);
990 
991 	if (skb) {
992 		struct ieee80211_hdr *hdr =
993 			(struct ieee80211_hdr *) skb->data;
994 
995 		/*
996 		 * Tell TX path to send one frame even though the STA may
997 		 * still remain is PS mode after this frame exchange.
998 		 */
999 		set_sta_flags(rx->sta, WLAN_STA_PSPOLL);
1000 
1001 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
1002 		printk(KERN_DEBUG "STA %s aid %d: PS Poll (entries after %d)\n",
1003 		       print_mac(mac, rx->sta->addr), rx->sta->aid,
1004 		       skb_queue_len(&rx->sta->ps_tx_buf));
1005 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
1006 
1007 		/* Use MoreData flag to indicate whether there are more
1008 		 * buffered frames for this STA */
1009 		if (no_pending_pkts)
1010 			hdr->frame_control &= cpu_to_le16(~IEEE80211_FCTL_MOREDATA);
1011 		else
1012 			hdr->frame_control |= cpu_to_le16(IEEE80211_FCTL_MOREDATA);
1013 
1014 		dev_queue_xmit(skb);
1015 
1016 		if (no_pending_pkts)
1017 			sta_info_clear_tim_bit(rx->sta);
1018 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
1019 	} else if (!rx->sent_ps_buffered) {
1020 		/*
1021 		 * FIXME: This can be the result of a race condition between
1022 		 *	  us expiring a frame and the station polling for it.
1023 		 *	  Should we send it a null-func frame indicating we
1024 		 *	  have nothing buffered for it?
1025 		 */
1026 		printk(KERN_DEBUG "%s: STA %s sent PS Poll even "
1027 		       "though there are no buffered frames for it\n",
1028 		       rx->dev->name, print_mac(mac, rx->sta->addr));
1029 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
1030 	}
1031 
1032 	/* Free PS Poll skb here instead of returning RX_DROP that would
1033 	 * count as an dropped frame. */
1034 	dev_kfree_skb(rx->skb);
1035 
1036 	return RX_QUEUED;
1037 }
1038 
1039 static ieee80211_rx_result debug_noinline
1040 ieee80211_rx_h_remove_qos_control(struct ieee80211_rx_data *rx)
1041 {
1042 	u8 *data = rx->skb->data;
1043 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)data;
1044 
1045 	if (!ieee80211_is_data_qos(hdr->frame_control))
1046 		return RX_CONTINUE;
1047 
1048 	/* remove the qos control field, update frame type and meta-data */
1049 	memmove(data + IEEE80211_QOS_CTL_LEN, data,
1050 		ieee80211_hdrlen(hdr->frame_control) - IEEE80211_QOS_CTL_LEN);
1051 	hdr = (struct ieee80211_hdr *)skb_pull(rx->skb, IEEE80211_QOS_CTL_LEN);
1052 	/* change frame type to non QOS */
1053 	rx->fc &= ~IEEE80211_STYPE_QOS_DATA;
1054 	hdr->frame_control &= ~cpu_to_le16(IEEE80211_STYPE_QOS_DATA);
1055 
1056 	return RX_CONTINUE;
1057 }
1058 
1059 static int
1060 ieee80211_802_1x_port_control(struct ieee80211_rx_data *rx)
1061 {
1062 	if (unlikely(!rx->sta ||
1063 	    !test_sta_flags(rx->sta, WLAN_STA_AUTHORIZED)))
1064 		return -EACCES;
1065 
1066 	return 0;
1067 }
1068 
1069 static int
1070 ieee80211_drop_unencrypted(struct ieee80211_rx_data *rx)
1071 {
1072 	/*
1073 	 * Pass through unencrypted frames if the hardware has
1074 	 * decrypted them already.
1075 	 */
1076 	if (rx->status->flag & RX_FLAG_DECRYPTED)
1077 		return 0;
1078 
1079 	/* Drop unencrypted frames if key is set. */
1080 	if (unlikely(!(rx->fc & IEEE80211_FCTL_PROTECTED) &&
1081 		     (rx->fc & IEEE80211_FCTL_FTYPE) == IEEE80211_FTYPE_DATA &&
1082 		     (rx->fc & IEEE80211_FCTL_STYPE) != IEEE80211_STYPE_NULLFUNC &&
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 fc, 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 	fc = rx->fc;
1106 
1107 	if (unlikely(!WLAN_FC_DATA_PRESENT(fc)))
1108 		return -1;
1109 
1110 	hdrlen = ieee80211_get_hdrlen(fc);
1111 
1112 	if (ieee80211_vif_is_mesh(&sdata->vif))
1113 		hdrlen += ieee80211_get_mesh_hdrlen(
1114 				(struct ieee80211s_hdr *) (skb->data + hdrlen));
1115 
1116 	/* convert IEEE 802.11 header + possible LLC headers into Ethernet
1117 	 * header
1118 	 * IEEE 802.11 address fields:
1119 	 * ToDS FromDS Addr1 Addr2 Addr3 Addr4
1120 	 *   0     0   DA    SA    BSSID n/a
1121 	 *   0     1   DA    BSSID SA    n/a
1122 	 *   1     0   BSSID SA    DA    n/a
1123 	 *   1     1   RA    TA    DA    SA
1124 	 */
1125 
1126 	switch (fc & (IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS)) {
1127 	case IEEE80211_FCTL_TODS:
1128 		/* BSSID SA DA */
1129 		memcpy(dst, hdr->addr3, ETH_ALEN);
1130 		memcpy(src, hdr->addr2, ETH_ALEN);
1131 
1132 		if (unlikely(sdata->vif.type != IEEE80211_IF_TYPE_AP &&
1133 			     sdata->vif.type != IEEE80211_IF_TYPE_VLAN))
1134 			return -1;
1135 		break;
1136 	case (IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS):
1137 		/* RA TA DA SA */
1138 		memcpy(dst, hdr->addr3, ETH_ALEN);
1139 		memcpy(src, hdr->addr4, ETH_ALEN);
1140 
1141 		 if (unlikely(sdata->vif.type != IEEE80211_IF_TYPE_WDS &&
1142 			     sdata->vif.type != IEEE80211_IF_TYPE_MESH_POINT))
1143 			return -1;
1144 		break;
1145 	case IEEE80211_FCTL_FROMDS:
1146 		/* DA BSSID SA */
1147 		memcpy(dst, hdr->addr1, ETH_ALEN);
1148 		memcpy(src, hdr->addr3, ETH_ALEN);
1149 
1150 		if (sdata->vif.type != IEEE80211_IF_TYPE_STA ||
1151 		    (is_multicast_ether_addr(dst) &&
1152 		     !compare_ether_addr(src, dev->dev_addr)))
1153 			return -1;
1154 		break;
1155 	case 0:
1156 		/* DA SA BSSID */
1157 		memcpy(dst, hdr->addr1, ETH_ALEN);
1158 		memcpy(src, hdr->addr2, ETH_ALEN);
1159 
1160 		if (sdata->vif.type != IEEE80211_IF_TYPE_IBSS)
1161 			return -1;
1162 		break;
1163 	}
1164 
1165 	if (unlikely(skb->len - hdrlen < 8))
1166 		return -1;
1167 
1168 	payload = skb->data + hdrlen;
1169 	ethertype = (payload[6] << 8) | payload[7];
1170 
1171 	if (likely((compare_ether_addr(payload, rfc1042_header) == 0 &&
1172 		    ethertype != ETH_P_AARP && ethertype != ETH_P_IPX) ||
1173 		   compare_ether_addr(payload, bridge_tunnel_header) == 0)) {
1174 		/* remove RFC1042 or Bridge-Tunnel encapsulation and
1175 		 * replace EtherType */
1176 		skb_pull(skb, hdrlen + 6);
1177 		memcpy(skb_push(skb, ETH_ALEN), src, ETH_ALEN);
1178 		memcpy(skb_push(skb, ETH_ALEN), dst, ETH_ALEN);
1179 	} else {
1180 		struct ethhdr *ehdr;
1181 		__be16 len;
1182 
1183 		skb_pull(skb, hdrlen);
1184 		len = htons(skb->len);
1185 		ehdr = (struct ethhdr *) skb_push(skb, sizeof(struct ethhdr));
1186 		memcpy(ehdr->h_dest, dst, ETH_ALEN);
1187 		memcpy(ehdr->h_source, src, ETH_ALEN);
1188 		ehdr->h_proto = len;
1189 	}
1190 	return 0;
1191 }
1192 
1193 /*
1194  * requires that rx->skb is a frame with ethernet header
1195  */
1196 static bool ieee80211_frame_allowed(struct ieee80211_rx_data *rx)
1197 {
1198 	static const u8 pae_group_addr[ETH_ALEN] __aligned(2)
1199 		= { 0x01, 0x80, 0xC2, 0x00, 0x00, 0x03 };
1200 	struct ethhdr *ehdr = (struct ethhdr *) rx->skb->data;
1201 
1202 	/*
1203 	 * Allow EAPOL frames to us/the PAE group address regardless
1204 	 * of whether the frame was encrypted or not.
1205 	 */
1206 	if (ehdr->h_proto == htons(ETH_P_PAE) &&
1207 	    (compare_ether_addr(ehdr->h_dest, rx->dev->dev_addr) == 0 ||
1208 	     compare_ether_addr(ehdr->h_dest, pae_group_addr) == 0))
1209 		return true;
1210 
1211 	if (ieee80211_802_1x_port_control(rx) ||
1212 	    ieee80211_drop_unencrypted(rx))
1213 		return false;
1214 
1215 	return true;
1216 }
1217 
1218 /*
1219  * requires that rx->skb is a frame with ethernet header
1220  */
1221 static void
1222 ieee80211_deliver_skb(struct ieee80211_rx_data *rx)
1223 {
1224 	struct net_device *dev = rx->dev;
1225 	struct ieee80211_local *local = rx->local;
1226 	struct sk_buff *skb, *xmit_skb;
1227 	struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
1228 	struct ethhdr *ehdr = (struct ethhdr *) rx->skb->data;
1229 	struct sta_info *dsta;
1230 
1231 	skb = rx->skb;
1232 	xmit_skb = NULL;
1233 
1234 	if (local->bridge_packets && (sdata->vif.type == IEEE80211_IF_TYPE_AP ||
1235 				      sdata->vif.type == IEEE80211_IF_TYPE_VLAN) &&
1236 	    (rx->flags & IEEE80211_RX_RA_MATCH)) {
1237 		if (is_multicast_ether_addr(ehdr->h_dest)) {
1238 			/*
1239 			 * send multicast frames both to higher layers in
1240 			 * local net stack and back to the wireless medium
1241 			 */
1242 			xmit_skb = skb_copy(skb, GFP_ATOMIC);
1243 			if (!xmit_skb && net_ratelimit())
1244 				printk(KERN_DEBUG "%s: failed to clone "
1245 				       "multicast frame\n", dev->name);
1246 		} else {
1247 			dsta = sta_info_get(local, skb->data);
1248 			if (dsta && dsta->sdata->dev == dev) {
1249 				/*
1250 				 * The destination station is associated to
1251 				 * this AP (in this VLAN), so send the frame
1252 				 * directly to it and do not pass it to local
1253 				 * net stack.
1254 				 */
1255 				xmit_skb = skb;
1256 				skb = NULL;
1257 			}
1258 		}
1259 	}
1260 
1261 	if (skb) {
1262 		/* deliver to local stack */
1263 		skb->protocol = eth_type_trans(skb, dev);
1264 		memset(skb->cb, 0, sizeof(skb->cb));
1265 		netif_rx(skb);
1266 	}
1267 
1268 	if (xmit_skb) {
1269 		/* send to wireless media */
1270 		xmit_skb->protocol = htons(ETH_P_802_3);
1271 		skb_reset_network_header(xmit_skb);
1272 		skb_reset_mac_header(xmit_skb);
1273 		dev_queue_xmit(xmit_skb);
1274 	}
1275 }
1276 
1277 static ieee80211_rx_result debug_noinline
1278 ieee80211_rx_h_amsdu(struct ieee80211_rx_data *rx)
1279 {
1280 	struct net_device *dev = rx->dev;
1281 	struct ieee80211_local *local = rx->local;
1282 	u16 fc, ethertype;
1283 	u8 *payload;
1284 	struct sk_buff *skb = rx->skb, *frame = NULL;
1285 	const struct ethhdr *eth;
1286 	int remaining, err;
1287 	u8 dst[ETH_ALEN];
1288 	u8 src[ETH_ALEN];
1289 	DECLARE_MAC_BUF(mac);
1290 
1291 	fc = rx->fc;
1292 	if (unlikely((fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_DATA))
1293 		return RX_CONTINUE;
1294 
1295 	if (unlikely(!WLAN_FC_DATA_PRESENT(fc)))
1296 		return RX_DROP_MONITOR;
1297 
1298 	if (!(rx->flags & IEEE80211_RX_AMSDU))
1299 		return RX_CONTINUE;
1300 
1301 	err = ieee80211_data_to_8023(rx);
1302 	if (unlikely(err))
1303 		return RX_DROP_UNUSABLE;
1304 
1305 	skb->dev = dev;
1306 
1307 	dev->stats.rx_packets++;
1308 	dev->stats.rx_bytes += skb->len;
1309 
1310 	/* skip the wrapping header */
1311 	eth = (struct ethhdr *) skb_pull(skb, sizeof(struct ethhdr));
1312 	if (!eth)
1313 		return RX_DROP_UNUSABLE;
1314 
1315 	while (skb != frame) {
1316 		u8 padding;
1317 		__be16 len = eth->h_proto;
1318 		unsigned int subframe_len = sizeof(struct ethhdr) + ntohs(len);
1319 
1320 		remaining = skb->len;
1321 		memcpy(dst, eth->h_dest, ETH_ALEN);
1322 		memcpy(src, eth->h_source, ETH_ALEN);
1323 
1324 		padding = ((4 - subframe_len) & 0x3);
1325 		/* the last MSDU has no padding */
1326 		if (subframe_len > remaining)
1327 			return RX_DROP_UNUSABLE;
1328 
1329 		skb_pull(skb, sizeof(struct ethhdr));
1330 		/* if last subframe reuse skb */
1331 		if (remaining <= subframe_len + padding)
1332 			frame = skb;
1333 		else {
1334 			frame = dev_alloc_skb(local->hw.extra_tx_headroom +
1335 					      subframe_len);
1336 
1337 			if (frame == NULL)
1338 				return RX_DROP_UNUSABLE;
1339 
1340 			skb_reserve(frame, local->hw.extra_tx_headroom +
1341 				    sizeof(struct ethhdr));
1342 			memcpy(skb_put(frame, ntohs(len)), skb->data,
1343 				ntohs(len));
1344 
1345 			eth = (struct ethhdr *) skb_pull(skb, ntohs(len) +
1346 							padding);
1347 			if (!eth) {
1348 				dev_kfree_skb(frame);
1349 				return RX_DROP_UNUSABLE;
1350 			}
1351 		}
1352 
1353 		skb_reset_network_header(frame);
1354 		frame->dev = dev;
1355 		frame->priority = skb->priority;
1356 		rx->skb = frame;
1357 
1358 		payload = frame->data;
1359 		ethertype = (payload[6] << 8) | payload[7];
1360 
1361 		if (likely((compare_ether_addr(payload, rfc1042_header) == 0 &&
1362 			    ethertype != ETH_P_AARP && ethertype != ETH_P_IPX) ||
1363 			   compare_ether_addr(payload,
1364 					      bridge_tunnel_header) == 0)) {
1365 			/* remove RFC1042 or Bridge-Tunnel
1366 			 * encapsulation and replace EtherType */
1367 			skb_pull(frame, 6);
1368 			memcpy(skb_push(frame, ETH_ALEN), src, ETH_ALEN);
1369 			memcpy(skb_push(frame, ETH_ALEN), dst, ETH_ALEN);
1370 		} else {
1371 			memcpy(skb_push(frame, sizeof(__be16)),
1372 			       &len, sizeof(__be16));
1373 			memcpy(skb_push(frame, ETH_ALEN), src, ETH_ALEN);
1374 			memcpy(skb_push(frame, ETH_ALEN), dst, ETH_ALEN);
1375 		}
1376 
1377 		if (!ieee80211_frame_allowed(rx)) {
1378 			if (skb == frame) /* last frame */
1379 				return RX_DROP_UNUSABLE;
1380 			dev_kfree_skb(frame);
1381 			continue;
1382 		}
1383 
1384 		ieee80211_deliver_skb(rx);
1385 	}
1386 
1387 	return RX_QUEUED;
1388 }
1389 
1390 static ieee80211_rx_result debug_noinline
1391 ieee80211_rx_h_mesh_fwding(struct ieee80211_rx_data *rx)
1392 {
1393 	struct ieee80211_hdr *hdr;
1394 	struct ieee80211s_hdr *mesh_hdr;
1395 	unsigned int hdrlen;
1396 	struct sk_buff *skb = rx->skb, *fwd_skb;
1397 
1398 	hdr = (struct ieee80211_hdr *) skb->data;
1399 	hdrlen = ieee80211_hdrlen(hdr->frame_control);
1400 	mesh_hdr = (struct ieee80211s_hdr *) (skb->data + hdrlen);
1401 
1402 	if (!ieee80211_is_data(hdr->frame_control))
1403 		return RX_CONTINUE;
1404 
1405 	if (!mesh_hdr->ttl)
1406 		/* illegal frame */
1407 		return RX_DROP_MONITOR;
1408 
1409 	if (compare_ether_addr(rx->dev->dev_addr, hdr->addr3) == 0)
1410 		return RX_CONTINUE;
1411 
1412 	mesh_hdr->ttl--;
1413 
1414 	if (rx->flags & IEEE80211_RX_RA_MATCH) {
1415 		if (!mesh_hdr->ttl)
1416 			IEEE80211_IFSTA_MESH_CTR_INC(&rx->sdata->u.sta,
1417 						     dropped_frames_ttl);
1418 		else {
1419 			struct ieee80211_hdr *fwd_hdr;
1420 			fwd_skb = skb_copy(skb, GFP_ATOMIC);
1421 
1422 			if (!fwd_skb && net_ratelimit())
1423 				printk(KERN_DEBUG "%s: failed to clone mesh frame\n",
1424 						   rx->dev->name);
1425 
1426 			fwd_hdr =  (struct ieee80211_hdr *) fwd_skb->data;
1427 			/*
1428 			 * Save TA to addr1 to send TA a path error if a
1429 			 * suitable next hop is not found
1430 			 */
1431 			memcpy(fwd_hdr->addr1, fwd_hdr->addr2, ETH_ALEN);
1432 			memcpy(fwd_hdr->addr2, rx->dev->dev_addr, ETH_ALEN);
1433 			fwd_skb->dev = rx->local->mdev;
1434 			fwd_skb->iif = rx->dev->ifindex;
1435 			dev_queue_xmit(fwd_skb);
1436 		}
1437 	}
1438 
1439 	if (is_multicast_ether_addr(hdr->addr3) ||
1440 	    rx->dev->flags & IFF_PROMISC)
1441 		return RX_CONTINUE;
1442 	else
1443 		return RX_DROP_MONITOR;
1444 }
1445 
1446 
1447 static ieee80211_rx_result debug_noinline
1448 ieee80211_rx_h_data(struct ieee80211_rx_data *rx)
1449 {
1450 	struct net_device *dev = rx->dev;
1451 	u16 fc;
1452 	int err;
1453 
1454 	fc = rx->fc;
1455 	if (unlikely((fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_DATA))
1456 		return RX_CONTINUE;
1457 
1458 	if (unlikely(!WLAN_FC_DATA_PRESENT(fc)))
1459 		return RX_DROP_MONITOR;
1460 
1461 	err = ieee80211_data_to_8023(rx);
1462 	if (unlikely(err))
1463 		return RX_DROP_UNUSABLE;
1464 
1465 	if (!ieee80211_frame_allowed(rx))
1466 		return RX_DROP_MONITOR;
1467 
1468 	rx->skb->dev = dev;
1469 
1470 	dev->stats.rx_packets++;
1471 	dev->stats.rx_bytes += rx->skb->len;
1472 
1473 	ieee80211_deliver_skb(rx);
1474 
1475 	return RX_QUEUED;
1476 }
1477 
1478 static ieee80211_rx_result debug_noinline
1479 ieee80211_rx_h_ctrl(struct ieee80211_rx_data *rx)
1480 {
1481 	struct ieee80211_local *local = rx->local;
1482 	struct ieee80211_hw *hw = &local->hw;
1483 	struct sk_buff *skb = rx->skb;
1484 	struct ieee80211_bar *bar = (struct ieee80211_bar *)skb->data;
1485 	struct tid_ampdu_rx *tid_agg_rx;
1486 	u16 start_seq_num;
1487 	u16 tid;
1488 
1489 	if (likely(!ieee80211_is_ctl(bar->frame_control)))
1490 		return RX_CONTINUE;
1491 
1492 	if (ieee80211_is_back_req(bar->frame_control)) {
1493 		if (!rx->sta)
1494 			return RX_CONTINUE;
1495 		tid = le16_to_cpu(bar->control) >> 12;
1496 		if (rx->sta->ampdu_mlme.tid_state_rx[tid]
1497 					!= HT_AGG_STATE_OPERATIONAL)
1498 			return RX_CONTINUE;
1499 		tid_agg_rx = rx->sta->ampdu_mlme.tid_rx[tid];
1500 
1501 		start_seq_num = le16_to_cpu(bar->start_seq_num) >> 4;
1502 
1503 		/* reset session timer */
1504 		if (tid_agg_rx->timeout) {
1505 			unsigned long expires =
1506 				jiffies + (tid_agg_rx->timeout / 1000) * HZ;
1507 			mod_timer(&tid_agg_rx->session_timer, expires);
1508 		}
1509 
1510 		/* manage reordering buffer according to requested */
1511 		/* sequence number */
1512 		rcu_read_lock();
1513 		ieee80211_sta_manage_reorder_buf(hw, tid_agg_rx, NULL,
1514 						 start_seq_num, 1);
1515 		rcu_read_unlock();
1516 		return RX_DROP_UNUSABLE;
1517 	}
1518 
1519 	return RX_CONTINUE;
1520 }
1521 
1522 static ieee80211_rx_result debug_noinline
1523 ieee80211_rx_h_mgmt(struct ieee80211_rx_data *rx)
1524 {
1525 	struct ieee80211_sub_if_data *sdata;
1526 
1527 	if (!(rx->flags & IEEE80211_RX_RA_MATCH))
1528 		return RX_DROP_MONITOR;
1529 
1530 	sdata = IEEE80211_DEV_TO_SUB_IF(rx->dev);
1531 	if ((sdata->vif.type == IEEE80211_IF_TYPE_STA ||
1532 	     sdata->vif.type == IEEE80211_IF_TYPE_IBSS ||
1533 	     sdata->vif.type == IEEE80211_IF_TYPE_MESH_POINT) &&
1534 	    !(sdata->flags & IEEE80211_SDATA_USERSPACE_MLME))
1535 		ieee80211_sta_rx_mgmt(rx->dev, rx->skb, rx->status);
1536 	else
1537 		return RX_DROP_MONITOR;
1538 
1539 	return RX_QUEUED;
1540 }
1541 
1542 static void ieee80211_rx_michael_mic_report(struct net_device *dev,
1543 					    struct ieee80211_hdr *hdr,
1544 					    struct ieee80211_rx_data *rx)
1545 {
1546 	int keyidx;
1547 	unsigned int hdrlen;
1548 	DECLARE_MAC_BUF(mac);
1549 	DECLARE_MAC_BUF(mac2);
1550 
1551 	hdrlen = ieee80211_hdrlen(hdr->frame_control);
1552 	if (rx->skb->len >= hdrlen + 4)
1553 		keyidx = rx->skb->data[hdrlen + 3] >> 6;
1554 	else
1555 		keyidx = -1;
1556 
1557 	if (!rx->sta) {
1558 		/*
1559 		 * Some hardware seem to generate incorrect Michael MIC
1560 		 * reports; ignore them to avoid triggering countermeasures.
1561 		 */
1562 		goto ignore;
1563 	}
1564 
1565 	if (!ieee80211_has_protected(hdr->frame_control))
1566 		goto ignore;
1567 
1568 	if (rx->sdata->vif.type == IEEE80211_IF_TYPE_AP && keyidx) {
1569 		/*
1570 		 * APs with pairwise keys should never receive Michael MIC
1571 		 * errors for non-zero keyidx because these are reserved for
1572 		 * group keys and only the AP is sending real multicast
1573 		 * frames in the BSS.
1574 		 */
1575 		goto ignore;
1576 	}
1577 
1578 	if (!ieee80211_is_data(hdr->frame_control) &&
1579 	    !ieee80211_is_auth(hdr->frame_control))
1580 		goto ignore;
1581 
1582 	mac80211_ev_michael_mic_failure(rx->dev, keyidx, hdr);
1583  ignore:
1584 	dev_kfree_skb(rx->skb);
1585 	rx->skb = NULL;
1586 }
1587 
1588 /* TODO: use IEEE80211_RX_FRAGMENTED */
1589 static void ieee80211_rx_cooked_monitor(struct ieee80211_rx_data *rx)
1590 {
1591 	struct ieee80211_sub_if_data *sdata;
1592 	struct ieee80211_local *local = rx->local;
1593 	struct ieee80211_rtap_hdr {
1594 		struct ieee80211_radiotap_header hdr;
1595 		u8 flags;
1596 		u8 rate;
1597 		__le16 chan_freq;
1598 		__le16 chan_flags;
1599 	} __attribute__ ((packed)) *rthdr;
1600 	struct sk_buff *skb = rx->skb, *skb2;
1601 	struct net_device *prev_dev = NULL;
1602 	struct ieee80211_rx_status *status = rx->status;
1603 
1604 	if (rx->flags & IEEE80211_RX_CMNTR_REPORTED)
1605 		goto out_free_skb;
1606 
1607 	if (skb_headroom(skb) < sizeof(*rthdr) &&
1608 	    pskb_expand_head(skb, sizeof(*rthdr), 0, GFP_ATOMIC))
1609 		goto out_free_skb;
1610 
1611 	rthdr = (void *)skb_push(skb, sizeof(*rthdr));
1612 	memset(rthdr, 0, sizeof(*rthdr));
1613 	rthdr->hdr.it_len = cpu_to_le16(sizeof(*rthdr));
1614 	rthdr->hdr.it_present =
1615 		cpu_to_le32((1 << IEEE80211_RADIOTAP_FLAGS) |
1616 			    (1 << IEEE80211_RADIOTAP_RATE) |
1617 			    (1 << IEEE80211_RADIOTAP_CHANNEL));
1618 
1619 	rthdr->rate = rx->rate->bitrate / 5;
1620 	rthdr->chan_freq = cpu_to_le16(status->freq);
1621 
1622 	if (status->band == IEEE80211_BAND_5GHZ)
1623 		rthdr->chan_flags = cpu_to_le16(IEEE80211_CHAN_OFDM |
1624 						IEEE80211_CHAN_5GHZ);
1625 	else
1626 		rthdr->chan_flags = cpu_to_le16(IEEE80211_CHAN_DYN |
1627 						IEEE80211_CHAN_2GHZ);
1628 
1629 	skb_set_mac_header(skb, 0);
1630 	skb->ip_summed = CHECKSUM_UNNECESSARY;
1631 	skb->pkt_type = PACKET_OTHERHOST;
1632 	skb->protocol = htons(ETH_P_802_2);
1633 
1634 	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
1635 		if (!netif_running(sdata->dev))
1636 			continue;
1637 
1638 		if (sdata->vif.type != IEEE80211_IF_TYPE_MNTR ||
1639 		    !(sdata->u.mntr_flags & MONITOR_FLAG_COOK_FRAMES))
1640 			continue;
1641 
1642 		if (prev_dev) {
1643 			skb2 = skb_clone(skb, GFP_ATOMIC);
1644 			if (skb2) {
1645 				skb2->dev = prev_dev;
1646 				netif_rx(skb2);
1647 			}
1648 		}
1649 
1650 		prev_dev = sdata->dev;
1651 		sdata->dev->stats.rx_packets++;
1652 		sdata->dev->stats.rx_bytes += skb->len;
1653 	}
1654 
1655 	if (prev_dev) {
1656 		skb->dev = prev_dev;
1657 		netif_rx(skb);
1658 		skb = NULL;
1659 	} else
1660 		goto out_free_skb;
1661 
1662 	rx->flags |= IEEE80211_RX_CMNTR_REPORTED;
1663 	return;
1664 
1665  out_free_skb:
1666 	dev_kfree_skb(skb);
1667 }
1668 
1669 
1670 static void ieee80211_invoke_rx_handlers(struct ieee80211_sub_if_data *sdata,
1671 					 struct ieee80211_rx_data *rx,
1672 					 struct sk_buff *skb)
1673 {
1674 	ieee80211_rx_result res = RX_DROP_MONITOR;
1675 
1676 	rx->skb = skb;
1677 	rx->sdata = sdata;
1678 	rx->dev = sdata->dev;
1679 
1680 #define CALL_RXH(rxh)			\
1681 	do {				\
1682 		res = rxh(rx);		\
1683 		if (res != RX_CONTINUE)	\
1684 			goto rxh_done;  \
1685 	} while (0);
1686 
1687 	CALL_RXH(ieee80211_rx_h_passive_scan)
1688 	CALL_RXH(ieee80211_rx_h_check)
1689 	CALL_RXH(ieee80211_rx_h_decrypt)
1690 	CALL_RXH(ieee80211_rx_h_sta_process)
1691 	CALL_RXH(ieee80211_rx_h_defragment)
1692 	CALL_RXH(ieee80211_rx_h_ps_poll)
1693 	CALL_RXH(ieee80211_rx_h_michael_mic_verify)
1694 	/* must be after MMIC verify so header is counted in MPDU mic */
1695 	CALL_RXH(ieee80211_rx_h_remove_qos_control)
1696 	CALL_RXH(ieee80211_rx_h_amsdu)
1697 	if (ieee80211_vif_is_mesh(&sdata->vif))
1698 		CALL_RXH(ieee80211_rx_h_mesh_fwding);
1699 	CALL_RXH(ieee80211_rx_h_data)
1700 	CALL_RXH(ieee80211_rx_h_ctrl)
1701 	CALL_RXH(ieee80211_rx_h_mgmt)
1702 
1703 #undef CALL_RXH
1704 
1705  rxh_done:
1706 	switch (res) {
1707 	case RX_DROP_MONITOR:
1708 		I802_DEBUG_INC(sdata->local->rx_handlers_drop);
1709 		if (rx->sta)
1710 			rx->sta->rx_dropped++;
1711 		/* fall through */
1712 	case RX_CONTINUE:
1713 		ieee80211_rx_cooked_monitor(rx);
1714 		break;
1715 	case RX_DROP_UNUSABLE:
1716 		I802_DEBUG_INC(sdata->local->rx_handlers_drop);
1717 		if (rx->sta)
1718 			rx->sta->rx_dropped++;
1719 		dev_kfree_skb(rx->skb);
1720 		break;
1721 	case RX_QUEUED:
1722 		I802_DEBUG_INC(sdata->local->rx_handlers_queued);
1723 		break;
1724 	}
1725 }
1726 
1727 /* main receive path */
1728 
1729 static int prepare_for_handlers(struct ieee80211_sub_if_data *sdata,
1730 				u8 *bssid, struct ieee80211_rx_data *rx,
1731 				struct ieee80211_hdr *hdr)
1732 {
1733 	int multicast = is_multicast_ether_addr(hdr->addr1);
1734 
1735 	switch (sdata->vif.type) {
1736 	case IEEE80211_IF_TYPE_STA:
1737 		if (!bssid)
1738 			return 0;
1739 		if (!ieee80211_bssid_match(bssid, sdata->u.sta.bssid)) {
1740 			if (!(rx->flags & IEEE80211_RX_IN_SCAN))
1741 				return 0;
1742 			rx->flags &= ~IEEE80211_RX_RA_MATCH;
1743 		} else if (!multicast &&
1744 			   compare_ether_addr(sdata->dev->dev_addr,
1745 					      hdr->addr1) != 0) {
1746 			if (!(sdata->dev->flags & IFF_PROMISC))
1747 				return 0;
1748 			rx->flags &= ~IEEE80211_RX_RA_MATCH;
1749 		}
1750 		break;
1751 	case IEEE80211_IF_TYPE_IBSS:
1752 		if (!bssid)
1753 			return 0;
1754 		if (ieee80211_is_beacon(hdr->frame_control)) {
1755 			if (!rx->sta)
1756 				rx->sta = ieee80211_ibss_add_sta(sdata->dev,
1757 						rx->skb, bssid, hdr->addr2,
1758 						BIT(rx->status->rate_idx));
1759 			return 1;
1760 		}
1761 		else if (!ieee80211_bssid_match(bssid, sdata->u.sta.bssid)) {
1762 			if (!(rx->flags & IEEE80211_RX_IN_SCAN))
1763 				return 0;
1764 			rx->flags &= ~IEEE80211_RX_RA_MATCH;
1765 		} else if (!multicast &&
1766 			   compare_ether_addr(sdata->dev->dev_addr,
1767 					      hdr->addr1) != 0) {
1768 			if (!(sdata->dev->flags & IFF_PROMISC))
1769 				return 0;
1770 			rx->flags &= ~IEEE80211_RX_RA_MATCH;
1771 		} else if (!rx->sta)
1772 			rx->sta = ieee80211_ibss_add_sta(sdata->dev, rx->skb,
1773 						bssid, hdr->addr2,
1774 						BIT(rx->status->rate_idx));
1775 		break;
1776 	case IEEE80211_IF_TYPE_MESH_POINT:
1777 		if (!multicast &&
1778 		    compare_ether_addr(sdata->dev->dev_addr,
1779 				       hdr->addr1) != 0) {
1780 			if (!(sdata->dev->flags & IFF_PROMISC))
1781 				return 0;
1782 
1783 			rx->flags &= ~IEEE80211_RX_RA_MATCH;
1784 		}
1785 		break;
1786 	case IEEE80211_IF_TYPE_VLAN:
1787 	case IEEE80211_IF_TYPE_AP:
1788 		if (!bssid) {
1789 			if (compare_ether_addr(sdata->dev->dev_addr,
1790 					       hdr->addr1))
1791 				return 0;
1792 		} else if (!ieee80211_bssid_match(bssid,
1793 					sdata->dev->dev_addr)) {
1794 			if (!(rx->flags & IEEE80211_RX_IN_SCAN))
1795 				return 0;
1796 			rx->flags &= ~IEEE80211_RX_RA_MATCH;
1797 		}
1798 		break;
1799 	case IEEE80211_IF_TYPE_WDS:
1800 		if (bssid || !ieee80211_is_data(hdr->frame_control))
1801 			return 0;
1802 		if (compare_ether_addr(sdata->u.wds.remote_addr, hdr->addr2))
1803 			return 0;
1804 		break;
1805 	case IEEE80211_IF_TYPE_MNTR:
1806 		/* take everything */
1807 		break;
1808 	case IEEE80211_IF_TYPE_INVALID:
1809 		/* should never get here */
1810 		WARN_ON(1);
1811 		break;
1812 	}
1813 
1814 	return 1;
1815 }
1816 
1817 /*
1818  * This is the actual Rx frames handler. as it blongs to Rx path it must
1819  * be called with rcu_read_lock protection.
1820  */
1821 static void __ieee80211_rx_handle_packet(struct ieee80211_hw *hw,
1822 					 struct sk_buff *skb,
1823 					 struct ieee80211_rx_status *status,
1824 					 struct ieee80211_rate *rate)
1825 {
1826 	struct ieee80211_local *local = hw_to_local(hw);
1827 	struct ieee80211_sub_if_data *sdata;
1828 	struct ieee80211_hdr *hdr;
1829 	struct ieee80211_rx_data rx;
1830 	u16 type;
1831 	int prepares;
1832 	struct ieee80211_sub_if_data *prev = NULL;
1833 	struct sk_buff *skb_new;
1834 	u8 *bssid;
1835 
1836 	hdr = (struct ieee80211_hdr *) skb->data;
1837 	memset(&rx, 0, sizeof(rx));
1838 	rx.skb = skb;
1839 	rx.local = local;
1840 
1841 	rx.status = status;
1842 	rx.rate = rate;
1843 	rx.fc = le16_to_cpu(hdr->frame_control);
1844 	type = rx.fc & IEEE80211_FCTL_FTYPE;
1845 
1846 	if (type == IEEE80211_FTYPE_DATA || type == IEEE80211_FTYPE_MGMT)
1847 		local->dot11ReceivedFragmentCount++;
1848 
1849 	rx.sta = sta_info_get(local, hdr->addr2);
1850 	if (rx.sta) {
1851 		rx.sdata = rx.sta->sdata;
1852 		rx.dev = rx.sta->sdata->dev;
1853 	}
1854 
1855 	if ((status->flag & RX_FLAG_MMIC_ERROR)) {
1856 		ieee80211_rx_michael_mic_report(local->mdev, hdr, &rx);
1857 		return;
1858 	}
1859 
1860 	if (unlikely(local->sta_sw_scanning || local->sta_hw_scanning))
1861 		rx.flags |= IEEE80211_RX_IN_SCAN;
1862 
1863 	ieee80211_parse_qos(&rx);
1864 	ieee80211_verify_ip_alignment(&rx);
1865 
1866 	skb = rx.skb;
1867 
1868 	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
1869 		if (!netif_running(sdata->dev))
1870 			continue;
1871 
1872 		if (sdata->vif.type == IEEE80211_IF_TYPE_MNTR)
1873 			continue;
1874 
1875 		bssid = ieee80211_get_bssid(hdr, skb->len, sdata->vif.type);
1876 		rx.flags |= IEEE80211_RX_RA_MATCH;
1877 		prepares = prepare_for_handlers(sdata, bssid, &rx, hdr);
1878 
1879 		if (!prepares)
1880 			continue;
1881 
1882 		/*
1883 		 * frame is destined for this interface, but if it's not
1884 		 * also for the previous one we handle that after the
1885 		 * loop to avoid copying the SKB once too much
1886 		 */
1887 
1888 		if (!prev) {
1889 			prev = sdata;
1890 			continue;
1891 		}
1892 
1893 		/*
1894 		 * frame was destined for the previous interface
1895 		 * so invoke RX handlers for it
1896 		 */
1897 
1898 		skb_new = skb_copy(skb, GFP_ATOMIC);
1899 		if (!skb_new) {
1900 			if (net_ratelimit())
1901 				printk(KERN_DEBUG "%s: failed to copy "
1902 				       "multicast frame for %s\n",
1903 				       wiphy_name(local->hw.wiphy),
1904 				       prev->dev->name);
1905 			continue;
1906 		}
1907 		rx.fc = le16_to_cpu(hdr->frame_control);
1908 		ieee80211_invoke_rx_handlers(prev, &rx, skb_new);
1909 		prev = sdata;
1910 	}
1911 	if (prev) {
1912 		rx.fc = le16_to_cpu(hdr->frame_control);
1913 		ieee80211_invoke_rx_handlers(prev, &rx, skb);
1914 	} else
1915 		dev_kfree_skb(skb);
1916 }
1917 
1918 #define SEQ_MODULO 0x1000
1919 #define SEQ_MASK   0xfff
1920 
1921 static inline int seq_less(u16 sq1, u16 sq2)
1922 {
1923 	return (((sq1 - sq2) & SEQ_MASK) > (SEQ_MODULO >> 1));
1924 }
1925 
1926 static inline u16 seq_inc(u16 sq)
1927 {
1928 	return ((sq + 1) & SEQ_MASK);
1929 }
1930 
1931 static inline u16 seq_sub(u16 sq1, u16 sq2)
1932 {
1933 	return ((sq1 - sq2) & SEQ_MASK);
1934 }
1935 
1936 
1937 /*
1938  * As it function blongs to Rx path it must be called with
1939  * the proper rcu_read_lock protection for its flow.
1940  */
1941 u8 ieee80211_sta_manage_reorder_buf(struct ieee80211_hw *hw,
1942 				struct tid_ampdu_rx *tid_agg_rx,
1943 				struct sk_buff *skb, u16 mpdu_seq_num,
1944 				int bar_req)
1945 {
1946 	struct ieee80211_local *local = hw_to_local(hw);
1947 	struct ieee80211_rx_status status;
1948 	u16 head_seq_num, buf_size;
1949 	int index;
1950 	struct ieee80211_supported_band *sband;
1951 	struct ieee80211_rate *rate;
1952 
1953 	buf_size = tid_agg_rx->buf_size;
1954 	head_seq_num = tid_agg_rx->head_seq_num;
1955 
1956 	/* frame with out of date sequence number */
1957 	if (seq_less(mpdu_seq_num, head_seq_num)) {
1958 		dev_kfree_skb(skb);
1959 		return 1;
1960 	}
1961 
1962 	/* if frame sequence number exceeds our buffering window size or
1963 	 * block Ack Request arrived - release stored frames */
1964 	if ((!seq_less(mpdu_seq_num, head_seq_num + buf_size)) || (bar_req)) {
1965 		/* new head to the ordering buffer */
1966 		if (bar_req)
1967 			head_seq_num = mpdu_seq_num;
1968 		else
1969 			head_seq_num =
1970 				seq_inc(seq_sub(mpdu_seq_num, buf_size));
1971 		/* release stored frames up to new head to stack */
1972 		while (seq_less(tid_agg_rx->head_seq_num, head_seq_num)) {
1973 			index = seq_sub(tid_agg_rx->head_seq_num,
1974 				tid_agg_rx->ssn)
1975 				% tid_agg_rx->buf_size;
1976 
1977 			if (tid_agg_rx->reorder_buf[index]) {
1978 				/* release the reordered frames to stack */
1979 				memcpy(&status,
1980 					tid_agg_rx->reorder_buf[index]->cb,
1981 					sizeof(status));
1982 				sband = local->hw.wiphy->bands[status.band];
1983 				rate = &sband->bitrates[status.rate_idx];
1984 				__ieee80211_rx_handle_packet(hw,
1985 					tid_agg_rx->reorder_buf[index],
1986 					&status, rate);
1987 				tid_agg_rx->stored_mpdu_num--;
1988 				tid_agg_rx->reorder_buf[index] = NULL;
1989 			}
1990 			tid_agg_rx->head_seq_num =
1991 				seq_inc(tid_agg_rx->head_seq_num);
1992 		}
1993 		if (bar_req)
1994 			return 1;
1995 	}
1996 
1997 	/* now the new frame is always in the range of the reordering */
1998 	/* buffer window */
1999 	index = seq_sub(mpdu_seq_num, tid_agg_rx->ssn)
2000 				% tid_agg_rx->buf_size;
2001 	/* check if we already stored this frame */
2002 	if (tid_agg_rx->reorder_buf[index]) {
2003 		dev_kfree_skb(skb);
2004 		return 1;
2005 	}
2006 
2007 	/* if arrived mpdu is in the right order and nothing else stored */
2008 	/* release it immediately */
2009 	if (mpdu_seq_num == tid_agg_rx->head_seq_num &&
2010 			tid_agg_rx->stored_mpdu_num == 0) {
2011 		tid_agg_rx->head_seq_num =
2012 			seq_inc(tid_agg_rx->head_seq_num);
2013 		return 0;
2014 	}
2015 
2016 	/* put the frame in the reordering buffer */
2017 	tid_agg_rx->reorder_buf[index] = skb;
2018 	tid_agg_rx->stored_mpdu_num++;
2019 	/* release the buffer until next missing frame */
2020 	index = seq_sub(tid_agg_rx->head_seq_num, tid_agg_rx->ssn)
2021 						% tid_agg_rx->buf_size;
2022 	while (tid_agg_rx->reorder_buf[index]) {
2023 		/* release the reordered frame back to stack */
2024 		memcpy(&status, tid_agg_rx->reorder_buf[index]->cb,
2025 			sizeof(status));
2026 		sband = local->hw.wiphy->bands[status.band];
2027 		rate = &sband->bitrates[status.rate_idx];
2028 		__ieee80211_rx_handle_packet(hw, tid_agg_rx->reorder_buf[index],
2029 					     &status, rate);
2030 		tid_agg_rx->stored_mpdu_num--;
2031 		tid_agg_rx->reorder_buf[index] = NULL;
2032 		tid_agg_rx->head_seq_num = seq_inc(tid_agg_rx->head_seq_num);
2033 		index =	seq_sub(tid_agg_rx->head_seq_num,
2034 			tid_agg_rx->ssn) % tid_agg_rx->buf_size;
2035 	}
2036 	return 1;
2037 }
2038 
2039 static u8 ieee80211_rx_reorder_ampdu(struct ieee80211_local *local,
2040 				     struct sk_buff *skb)
2041 {
2042 	struct ieee80211_hw *hw = &local->hw;
2043 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
2044 	struct sta_info *sta;
2045 	struct tid_ampdu_rx *tid_agg_rx;
2046 	u16 sc;
2047 	u16 mpdu_seq_num;
2048 	u8 ret = 0;
2049 	int tid;
2050 
2051 	sta = sta_info_get(local, hdr->addr2);
2052 	if (!sta)
2053 		return ret;
2054 
2055 	/* filter the QoS data rx stream according to
2056 	 * STA/TID and check if this STA/TID is on aggregation */
2057 	if (!ieee80211_is_data_qos(hdr->frame_control))
2058 		goto end_reorder;
2059 
2060 	tid = *ieee80211_get_qos_ctl(hdr) & IEEE80211_QOS_CTL_TID_MASK;
2061 
2062 	if (sta->ampdu_mlme.tid_state_rx[tid] != HT_AGG_STATE_OPERATIONAL)
2063 		goto end_reorder;
2064 
2065 	tid_agg_rx = sta->ampdu_mlme.tid_rx[tid];
2066 
2067 	/* qos null data frames are excluded */
2068 	if (unlikely(hdr->frame_control & cpu_to_le16(IEEE80211_STYPE_NULLFUNC)))
2069 		goto end_reorder;
2070 
2071 	/* new un-ordered ampdu frame - process it */
2072 
2073 	/* reset session timer */
2074 	if (tid_agg_rx->timeout) {
2075 		unsigned long expires =
2076 			jiffies + (tid_agg_rx->timeout / 1000) * HZ;
2077 		mod_timer(&tid_agg_rx->session_timer, expires);
2078 	}
2079 
2080 	/* if this mpdu is fragmented - terminate rx aggregation session */
2081 	sc = le16_to_cpu(hdr->seq_ctrl);
2082 	if (sc & IEEE80211_SCTL_FRAG) {
2083 		ieee80211_sta_stop_rx_ba_session(sta->sdata->dev, sta->addr,
2084 			tid, 0, WLAN_REASON_QSTA_REQUIRE_SETUP);
2085 		ret = 1;
2086 		goto end_reorder;
2087 	}
2088 
2089 	/* according to mpdu sequence number deal with reordering buffer */
2090 	mpdu_seq_num = (sc & IEEE80211_SCTL_SEQ) >> 4;
2091 	ret = ieee80211_sta_manage_reorder_buf(hw, tid_agg_rx, skb,
2092 						mpdu_seq_num, 0);
2093  end_reorder:
2094 	return ret;
2095 }
2096 
2097 /*
2098  * This is the receive path handler. It is called by a low level driver when an
2099  * 802.11 MPDU is received from the hardware.
2100  */
2101 void __ieee80211_rx(struct ieee80211_hw *hw, struct sk_buff *skb,
2102 		    struct ieee80211_rx_status *status)
2103 {
2104 	struct ieee80211_local *local = hw_to_local(hw);
2105 	struct ieee80211_rate *rate = NULL;
2106 	struct ieee80211_supported_band *sband;
2107 
2108 	if (status->band < 0 ||
2109 	    status->band >= IEEE80211_NUM_BANDS) {
2110 		WARN_ON(1);
2111 		return;
2112 	}
2113 
2114 	sband = local->hw.wiphy->bands[status->band];
2115 
2116 	if (!sband ||
2117 	    status->rate_idx < 0 ||
2118 	    status->rate_idx >= sband->n_bitrates) {
2119 		WARN_ON(1);
2120 		return;
2121 	}
2122 
2123 	rate = &sband->bitrates[status->rate_idx];
2124 
2125 	/*
2126 	 * key references and virtual interfaces are protected using RCU
2127 	 * and this requires that we are in a read-side RCU section during
2128 	 * receive processing
2129 	 */
2130 	rcu_read_lock();
2131 
2132 	/*
2133 	 * Frames with failed FCS/PLCP checksum are not returned,
2134 	 * all other frames are returned without radiotap header
2135 	 * if it was previously present.
2136 	 * Also, frames with less than 16 bytes are dropped.
2137 	 */
2138 	skb = ieee80211_rx_monitor(local, skb, status, rate);
2139 	if (!skb) {
2140 		rcu_read_unlock();
2141 		return;
2142 	}
2143 
2144 	if (!ieee80211_rx_reorder_ampdu(local, skb))
2145 		__ieee80211_rx_handle_packet(hw, skb, status, rate);
2146 
2147 	rcu_read_unlock();
2148 }
2149 EXPORT_SYMBOL(__ieee80211_rx);
2150 
2151 /* This is a version of the rx handler that can be called from hard irq
2152  * context. Post the skb on the queue and schedule the tasklet */
2153 void ieee80211_rx_irqsafe(struct ieee80211_hw *hw, struct sk_buff *skb,
2154 			  struct ieee80211_rx_status *status)
2155 {
2156 	struct ieee80211_local *local = hw_to_local(hw);
2157 
2158 	BUILD_BUG_ON(sizeof(struct ieee80211_rx_status) > sizeof(skb->cb));
2159 
2160 	skb->dev = local->mdev;
2161 	/* copy status into skb->cb for use by tasklet */
2162 	memcpy(skb->cb, status, sizeof(*status));
2163 	skb->pkt_type = IEEE80211_RX_MSG;
2164 	skb_queue_tail(&local->skb_queue, skb);
2165 	tasklet_schedule(&local->tasklet);
2166 }
2167 EXPORT_SYMBOL(ieee80211_rx_irqsafe);
2168