xref: /openbmc/linux/net/mac80211/rx.c (revision 4a65896f94fa82370041823837cd75aac1186b54)
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 2007-2010	Johannes Berg <johannes@sipsolutions.net>
6  * Copyright 2013-2014  Intel Mobile Communications GmbH
7  * Copyright(c) 2015 - 2016 Intel Deutschland GmbH
8  *
9  * This program is free software; you can redistribute it and/or modify
10  * it under the terms of the GNU General Public License version 2 as
11  * published by the Free Software Foundation.
12  */
13 
14 #include <linux/jiffies.h>
15 #include <linux/slab.h>
16 #include <linux/kernel.h>
17 #include <linux/skbuff.h>
18 #include <linux/netdevice.h>
19 #include <linux/etherdevice.h>
20 #include <linux/rcupdate.h>
21 #include <linux/export.h>
22 #include <linux/bitops.h>
23 #include <net/mac80211.h>
24 #include <net/ieee80211_radiotap.h>
25 #include <asm/unaligned.h>
26 
27 #include "ieee80211_i.h"
28 #include "driver-ops.h"
29 #include "led.h"
30 #include "mesh.h"
31 #include "wep.h"
32 #include "wpa.h"
33 #include "tkip.h"
34 #include "wme.h"
35 #include "rate.h"
36 
37 static inline void ieee80211_rx_stats(struct net_device *dev, u32 len)
38 {
39 	struct pcpu_sw_netstats *tstats = this_cpu_ptr(dev->tstats);
40 
41 	u64_stats_update_begin(&tstats->syncp);
42 	tstats->rx_packets++;
43 	tstats->rx_bytes += len;
44 	u64_stats_update_end(&tstats->syncp);
45 }
46 
47 static u8 *ieee80211_get_bssid(struct ieee80211_hdr *hdr, size_t len,
48 			       enum nl80211_iftype type)
49 {
50 	__le16 fc = hdr->frame_control;
51 
52 	if (ieee80211_is_data(fc)) {
53 		if (len < 24) /* drop incorrect hdr len (data) */
54 			return NULL;
55 
56 		if (ieee80211_has_a4(fc))
57 			return NULL;
58 		if (ieee80211_has_tods(fc))
59 			return hdr->addr1;
60 		if (ieee80211_has_fromds(fc))
61 			return hdr->addr2;
62 
63 		return hdr->addr3;
64 	}
65 
66 	if (ieee80211_is_mgmt(fc)) {
67 		if (len < 24) /* drop incorrect hdr len (mgmt) */
68 			return NULL;
69 		return hdr->addr3;
70 	}
71 
72 	if (ieee80211_is_ctl(fc)) {
73 		if (ieee80211_is_pspoll(fc))
74 			return hdr->addr1;
75 
76 		if (ieee80211_is_back_req(fc)) {
77 			switch (type) {
78 			case NL80211_IFTYPE_STATION:
79 				return hdr->addr2;
80 			case NL80211_IFTYPE_AP:
81 			case NL80211_IFTYPE_AP_VLAN:
82 				return hdr->addr1;
83 			default:
84 				break; /* fall through to the return */
85 			}
86 		}
87 	}
88 
89 	return NULL;
90 }
91 
92 /*
93  * monitor mode reception
94  *
95  * This function cleans up the SKB, i.e. it removes all the stuff
96  * only useful for monitoring.
97  */
98 static struct sk_buff *remove_monitor_info(struct ieee80211_local *local,
99 					   struct sk_buff *skb,
100 					   unsigned int rtap_vendor_space)
101 {
102 	if (ieee80211_hw_check(&local->hw, RX_INCLUDES_FCS)) {
103 		if (likely(skb->len > FCS_LEN))
104 			__pskb_trim(skb, skb->len - FCS_LEN);
105 		else {
106 			/* driver bug */
107 			WARN_ON(1);
108 			dev_kfree_skb(skb);
109 			return NULL;
110 		}
111 	}
112 
113 	__pskb_pull(skb, rtap_vendor_space);
114 
115 	return skb;
116 }
117 
118 static inline bool should_drop_frame(struct sk_buff *skb, int present_fcs_len,
119 				     unsigned int rtap_vendor_space)
120 {
121 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
122 	struct ieee80211_hdr *hdr;
123 
124 	hdr = (void *)(skb->data + rtap_vendor_space);
125 
126 	if (status->flag & (RX_FLAG_FAILED_FCS_CRC |
127 			    RX_FLAG_FAILED_PLCP_CRC |
128 			    RX_FLAG_ONLY_MONITOR))
129 		return true;
130 
131 	if (unlikely(skb->len < 16 + present_fcs_len + rtap_vendor_space))
132 		return true;
133 
134 	if (ieee80211_is_ctl(hdr->frame_control) &&
135 	    !ieee80211_is_pspoll(hdr->frame_control) &&
136 	    !ieee80211_is_back_req(hdr->frame_control))
137 		return true;
138 
139 	return false;
140 }
141 
142 static int
143 ieee80211_rx_radiotap_hdrlen(struct ieee80211_local *local,
144 			     struct ieee80211_rx_status *status,
145 			     struct sk_buff *skb)
146 {
147 	int len;
148 
149 	/* always present fields */
150 	len = sizeof(struct ieee80211_radiotap_header) + 8;
151 
152 	/* allocate extra bitmaps */
153 	if (status->chains)
154 		len += 4 * hweight8(status->chains);
155 
156 	if (ieee80211_have_rx_timestamp(status)) {
157 		len = ALIGN(len, 8);
158 		len += 8;
159 	}
160 	if (ieee80211_hw_check(&local->hw, SIGNAL_DBM))
161 		len += 1;
162 
163 	/* antenna field, if we don't have per-chain info */
164 	if (!status->chains)
165 		len += 1;
166 
167 	/* padding for RX_FLAGS if necessary */
168 	len = ALIGN(len, 2);
169 
170 	if (status->flag & RX_FLAG_HT) /* HT info */
171 		len += 3;
172 
173 	if (status->flag & RX_FLAG_AMPDU_DETAILS) {
174 		len = ALIGN(len, 4);
175 		len += 8;
176 	}
177 
178 	if (status->flag & RX_FLAG_VHT) {
179 		len = ALIGN(len, 2);
180 		len += 12;
181 	}
182 
183 	if (status->chains) {
184 		/* antenna and antenna signal fields */
185 		len += 2 * hweight8(status->chains);
186 	}
187 
188 	if (status->flag & RX_FLAG_RADIOTAP_VENDOR_DATA) {
189 		struct ieee80211_vendor_radiotap *rtap = (void *)skb->data;
190 
191 		/* vendor presence bitmap */
192 		len += 4;
193 		/* alignment for fixed 6-byte vendor data header */
194 		len = ALIGN(len, 2);
195 		/* vendor data header */
196 		len += 6;
197 		if (WARN_ON(rtap->align == 0))
198 			rtap->align = 1;
199 		len = ALIGN(len, rtap->align);
200 		len += rtap->len + rtap->pad;
201 	}
202 
203 	return len;
204 }
205 
206 /*
207  * ieee80211_add_rx_radiotap_header - add radiotap header
208  *
209  * add a radiotap header containing all the fields which the hardware provided.
210  */
211 static void
212 ieee80211_add_rx_radiotap_header(struct ieee80211_local *local,
213 				 struct sk_buff *skb,
214 				 struct ieee80211_rate *rate,
215 				 int rtap_len, bool has_fcs)
216 {
217 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
218 	struct ieee80211_radiotap_header *rthdr;
219 	unsigned char *pos;
220 	__le32 *it_present;
221 	u32 it_present_val;
222 	u16 rx_flags = 0;
223 	u16 channel_flags = 0;
224 	int mpdulen, chain;
225 	unsigned long chains = status->chains;
226 	struct ieee80211_vendor_radiotap rtap = {};
227 
228 	if (status->flag & RX_FLAG_RADIOTAP_VENDOR_DATA) {
229 		rtap = *(struct ieee80211_vendor_radiotap *)skb->data;
230 		/* rtap.len and rtap.pad are undone immediately */
231 		skb_pull(skb, sizeof(rtap) + rtap.len + rtap.pad);
232 	}
233 
234 	mpdulen = skb->len;
235 	if (!(has_fcs && ieee80211_hw_check(&local->hw, RX_INCLUDES_FCS)))
236 		mpdulen += FCS_LEN;
237 
238 	rthdr = (struct ieee80211_radiotap_header *)skb_push(skb, rtap_len);
239 	memset(rthdr, 0, rtap_len - rtap.len - rtap.pad);
240 	it_present = &rthdr->it_present;
241 
242 	/* radiotap header, set always present flags */
243 	rthdr->it_len = cpu_to_le16(rtap_len);
244 	it_present_val = BIT(IEEE80211_RADIOTAP_FLAGS) |
245 			 BIT(IEEE80211_RADIOTAP_CHANNEL) |
246 			 BIT(IEEE80211_RADIOTAP_RX_FLAGS);
247 
248 	if (!status->chains)
249 		it_present_val |= BIT(IEEE80211_RADIOTAP_ANTENNA);
250 
251 	for_each_set_bit(chain, &chains, IEEE80211_MAX_CHAINS) {
252 		it_present_val |=
253 			BIT(IEEE80211_RADIOTAP_EXT) |
254 			BIT(IEEE80211_RADIOTAP_RADIOTAP_NAMESPACE);
255 		put_unaligned_le32(it_present_val, it_present);
256 		it_present++;
257 		it_present_val = BIT(IEEE80211_RADIOTAP_ANTENNA) |
258 				 BIT(IEEE80211_RADIOTAP_DBM_ANTSIGNAL);
259 	}
260 
261 	if (status->flag & RX_FLAG_RADIOTAP_VENDOR_DATA) {
262 		it_present_val |= BIT(IEEE80211_RADIOTAP_VENDOR_NAMESPACE) |
263 				  BIT(IEEE80211_RADIOTAP_EXT);
264 		put_unaligned_le32(it_present_val, it_present);
265 		it_present++;
266 		it_present_val = rtap.present;
267 	}
268 
269 	put_unaligned_le32(it_present_val, it_present);
270 
271 	pos = (void *)(it_present + 1);
272 
273 	/* the order of the following fields is important */
274 
275 	/* IEEE80211_RADIOTAP_TSFT */
276 	if (ieee80211_have_rx_timestamp(status)) {
277 		/* padding */
278 		while ((pos - (u8 *)rthdr) & 7)
279 			*pos++ = 0;
280 		put_unaligned_le64(
281 			ieee80211_calculate_rx_timestamp(local, status,
282 							 mpdulen, 0),
283 			pos);
284 		rthdr->it_present |= cpu_to_le32(1 << IEEE80211_RADIOTAP_TSFT);
285 		pos += 8;
286 	}
287 
288 	/* IEEE80211_RADIOTAP_FLAGS */
289 	if (has_fcs && ieee80211_hw_check(&local->hw, RX_INCLUDES_FCS))
290 		*pos |= IEEE80211_RADIOTAP_F_FCS;
291 	if (status->flag & (RX_FLAG_FAILED_FCS_CRC | RX_FLAG_FAILED_PLCP_CRC))
292 		*pos |= IEEE80211_RADIOTAP_F_BADFCS;
293 	if (status->flag & RX_FLAG_SHORTPRE)
294 		*pos |= IEEE80211_RADIOTAP_F_SHORTPRE;
295 	pos++;
296 
297 	/* IEEE80211_RADIOTAP_RATE */
298 	if (!rate || status->flag & (RX_FLAG_HT | RX_FLAG_VHT)) {
299 		/*
300 		 * Without rate information don't add it. If we have,
301 		 * MCS information is a separate field in radiotap,
302 		 * added below. The byte here is needed as padding
303 		 * for the channel though, so initialise it to 0.
304 		 */
305 		*pos = 0;
306 	} else {
307 		int shift = 0;
308 		rthdr->it_present |= cpu_to_le32(1 << IEEE80211_RADIOTAP_RATE);
309 		if (status->flag & RX_FLAG_10MHZ)
310 			shift = 1;
311 		else if (status->flag & RX_FLAG_5MHZ)
312 			shift = 2;
313 		*pos = DIV_ROUND_UP(rate->bitrate, 5 * (1 << shift));
314 	}
315 	pos++;
316 
317 	/* IEEE80211_RADIOTAP_CHANNEL */
318 	put_unaligned_le16(status->freq, pos);
319 	pos += 2;
320 	if (status->flag & RX_FLAG_10MHZ)
321 		channel_flags |= IEEE80211_CHAN_HALF;
322 	else if (status->flag & RX_FLAG_5MHZ)
323 		channel_flags |= IEEE80211_CHAN_QUARTER;
324 
325 	if (status->band == NL80211_BAND_5GHZ)
326 		channel_flags |= IEEE80211_CHAN_OFDM | IEEE80211_CHAN_5GHZ;
327 	else if (status->flag & (RX_FLAG_HT | RX_FLAG_VHT))
328 		channel_flags |= IEEE80211_CHAN_DYN | IEEE80211_CHAN_2GHZ;
329 	else if (rate && rate->flags & IEEE80211_RATE_ERP_G)
330 		channel_flags |= IEEE80211_CHAN_OFDM | IEEE80211_CHAN_2GHZ;
331 	else if (rate)
332 		channel_flags |= IEEE80211_CHAN_CCK | IEEE80211_CHAN_2GHZ;
333 	else
334 		channel_flags |= IEEE80211_CHAN_2GHZ;
335 	put_unaligned_le16(channel_flags, pos);
336 	pos += 2;
337 
338 	/* IEEE80211_RADIOTAP_DBM_ANTSIGNAL */
339 	if (ieee80211_hw_check(&local->hw, SIGNAL_DBM) &&
340 	    !(status->flag & RX_FLAG_NO_SIGNAL_VAL)) {
341 		*pos = status->signal;
342 		rthdr->it_present |=
343 			cpu_to_le32(1 << IEEE80211_RADIOTAP_DBM_ANTSIGNAL);
344 		pos++;
345 	}
346 
347 	/* IEEE80211_RADIOTAP_LOCK_QUALITY is missing */
348 
349 	if (!status->chains) {
350 		/* IEEE80211_RADIOTAP_ANTENNA */
351 		*pos = status->antenna;
352 		pos++;
353 	}
354 
355 	/* IEEE80211_RADIOTAP_DB_ANTNOISE is not used */
356 
357 	/* IEEE80211_RADIOTAP_RX_FLAGS */
358 	/* ensure 2 byte alignment for the 2 byte field as required */
359 	if ((pos - (u8 *)rthdr) & 1)
360 		*pos++ = 0;
361 	if (status->flag & RX_FLAG_FAILED_PLCP_CRC)
362 		rx_flags |= IEEE80211_RADIOTAP_F_RX_BADPLCP;
363 	put_unaligned_le16(rx_flags, pos);
364 	pos += 2;
365 
366 	if (status->flag & RX_FLAG_HT) {
367 		unsigned int stbc;
368 
369 		rthdr->it_present |= cpu_to_le32(1 << IEEE80211_RADIOTAP_MCS);
370 		*pos++ = local->hw.radiotap_mcs_details;
371 		*pos = 0;
372 		if (status->flag & RX_FLAG_SHORT_GI)
373 			*pos |= IEEE80211_RADIOTAP_MCS_SGI;
374 		if (status->flag & RX_FLAG_40MHZ)
375 			*pos |= IEEE80211_RADIOTAP_MCS_BW_40;
376 		if (status->flag & RX_FLAG_HT_GF)
377 			*pos |= IEEE80211_RADIOTAP_MCS_FMT_GF;
378 		if (status->flag & RX_FLAG_LDPC)
379 			*pos |= IEEE80211_RADIOTAP_MCS_FEC_LDPC;
380 		stbc = (status->flag & RX_FLAG_STBC_MASK) >> RX_FLAG_STBC_SHIFT;
381 		*pos |= stbc << IEEE80211_RADIOTAP_MCS_STBC_SHIFT;
382 		pos++;
383 		*pos++ = status->rate_idx;
384 	}
385 
386 	if (status->flag & RX_FLAG_AMPDU_DETAILS) {
387 		u16 flags = 0;
388 
389 		/* ensure 4 byte alignment */
390 		while ((pos - (u8 *)rthdr) & 3)
391 			pos++;
392 		rthdr->it_present |=
393 			cpu_to_le32(1 << IEEE80211_RADIOTAP_AMPDU_STATUS);
394 		put_unaligned_le32(status->ampdu_reference, pos);
395 		pos += 4;
396 		if (status->flag & RX_FLAG_AMPDU_LAST_KNOWN)
397 			flags |= IEEE80211_RADIOTAP_AMPDU_LAST_KNOWN;
398 		if (status->flag & RX_FLAG_AMPDU_IS_LAST)
399 			flags |= IEEE80211_RADIOTAP_AMPDU_IS_LAST;
400 		if (status->flag & RX_FLAG_AMPDU_DELIM_CRC_ERROR)
401 			flags |= IEEE80211_RADIOTAP_AMPDU_DELIM_CRC_ERR;
402 		if (status->flag & RX_FLAG_AMPDU_DELIM_CRC_KNOWN)
403 			flags |= IEEE80211_RADIOTAP_AMPDU_DELIM_CRC_KNOWN;
404 		put_unaligned_le16(flags, pos);
405 		pos += 2;
406 		if (status->flag & RX_FLAG_AMPDU_DELIM_CRC_KNOWN)
407 			*pos++ = status->ampdu_delimiter_crc;
408 		else
409 			*pos++ = 0;
410 		*pos++ = 0;
411 	}
412 
413 	if (status->flag & RX_FLAG_VHT) {
414 		u16 known = local->hw.radiotap_vht_details;
415 
416 		rthdr->it_present |= cpu_to_le32(1 << IEEE80211_RADIOTAP_VHT);
417 		put_unaligned_le16(known, pos);
418 		pos += 2;
419 		/* flags */
420 		if (status->flag & RX_FLAG_SHORT_GI)
421 			*pos |= IEEE80211_RADIOTAP_VHT_FLAG_SGI;
422 		/* in VHT, STBC is binary */
423 		if (status->flag & RX_FLAG_STBC_MASK)
424 			*pos |= IEEE80211_RADIOTAP_VHT_FLAG_STBC;
425 		if (status->vht_flag & RX_VHT_FLAG_BF)
426 			*pos |= IEEE80211_RADIOTAP_VHT_FLAG_BEAMFORMED;
427 		pos++;
428 		/* bandwidth */
429 		if (status->vht_flag & RX_VHT_FLAG_80MHZ)
430 			*pos++ = 4;
431 		else if (status->vht_flag & RX_VHT_FLAG_160MHZ)
432 			*pos++ = 11;
433 		else if (status->flag & RX_FLAG_40MHZ)
434 			*pos++ = 1;
435 		else /* 20 MHz */
436 			*pos++ = 0;
437 		/* MCS/NSS */
438 		*pos = (status->rate_idx << 4) | status->vht_nss;
439 		pos += 4;
440 		/* coding field */
441 		if (status->flag & RX_FLAG_LDPC)
442 			*pos |= IEEE80211_RADIOTAP_CODING_LDPC_USER0;
443 		pos++;
444 		/* group ID */
445 		pos++;
446 		/* partial_aid */
447 		pos += 2;
448 	}
449 
450 	for_each_set_bit(chain, &chains, IEEE80211_MAX_CHAINS) {
451 		*pos++ = status->chain_signal[chain];
452 		*pos++ = chain;
453 	}
454 
455 	if (status->flag & RX_FLAG_RADIOTAP_VENDOR_DATA) {
456 		/* ensure 2 byte alignment for the vendor field as required */
457 		if ((pos - (u8 *)rthdr) & 1)
458 			*pos++ = 0;
459 		*pos++ = rtap.oui[0];
460 		*pos++ = rtap.oui[1];
461 		*pos++ = rtap.oui[2];
462 		*pos++ = rtap.subns;
463 		put_unaligned_le16(rtap.len, pos);
464 		pos += 2;
465 		/* align the actual payload as requested */
466 		while ((pos - (u8 *)rthdr) & (rtap.align - 1))
467 			*pos++ = 0;
468 		/* data (and possible padding) already follows */
469 	}
470 }
471 
472 /*
473  * This function copies a received frame to all monitor interfaces and
474  * returns a cleaned-up SKB that no longer includes the FCS nor the
475  * radiotap header the driver might have added.
476  */
477 static struct sk_buff *
478 ieee80211_rx_monitor(struct ieee80211_local *local, struct sk_buff *origskb,
479 		     struct ieee80211_rate *rate)
480 {
481 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(origskb);
482 	struct ieee80211_sub_if_data *sdata;
483 	int rt_hdrlen, needed_headroom;
484 	struct sk_buff *skb, *skb2;
485 	struct net_device *prev_dev = NULL;
486 	int present_fcs_len = 0;
487 	unsigned int rtap_vendor_space = 0;
488 
489 	if (unlikely(status->flag & RX_FLAG_RADIOTAP_VENDOR_DATA)) {
490 		struct ieee80211_vendor_radiotap *rtap = (void *)origskb->data;
491 
492 		rtap_vendor_space = sizeof(*rtap) + rtap->len + rtap->pad;
493 	}
494 
495 	/*
496 	 * First, we may need to make a copy of the skb because
497 	 *  (1) we need to modify it for radiotap (if not present), and
498 	 *  (2) the other RX handlers will modify the skb we got.
499 	 *
500 	 * We don't need to, of course, if we aren't going to return
501 	 * the SKB because it has a bad FCS/PLCP checksum.
502 	 */
503 
504 	if (ieee80211_hw_check(&local->hw, RX_INCLUDES_FCS))
505 		present_fcs_len = FCS_LEN;
506 
507 	/* ensure hdr->frame_control and vendor radiotap data are in skb head */
508 	if (!pskb_may_pull(origskb, 2 + rtap_vendor_space)) {
509 		dev_kfree_skb(origskb);
510 		return NULL;
511 	}
512 
513 	if (!local->monitors || (status->flag & RX_FLAG_SKIP_MONITOR)) {
514 		if (should_drop_frame(origskb, present_fcs_len,
515 				      rtap_vendor_space)) {
516 			dev_kfree_skb(origskb);
517 			return NULL;
518 		}
519 
520 		return remove_monitor_info(local, origskb, rtap_vendor_space);
521 	}
522 
523 	/* room for the radiotap header based on driver features */
524 	rt_hdrlen = ieee80211_rx_radiotap_hdrlen(local, status, origskb);
525 	needed_headroom = rt_hdrlen - rtap_vendor_space;
526 
527 	if (should_drop_frame(origskb, present_fcs_len, rtap_vendor_space)) {
528 		/* only need to expand headroom if necessary */
529 		skb = origskb;
530 		origskb = NULL;
531 
532 		/*
533 		 * This shouldn't trigger often because most devices have an
534 		 * RX header they pull before we get here, and that should
535 		 * be big enough for our radiotap information. We should
536 		 * probably export the length to drivers so that we can have
537 		 * them allocate enough headroom to start with.
538 		 */
539 		if (skb_headroom(skb) < needed_headroom &&
540 		    pskb_expand_head(skb, needed_headroom, 0, GFP_ATOMIC)) {
541 			dev_kfree_skb(skb);
542 			return NULL;
543 		}
544 	} else {
545 		/*
546 		 * Need to make a copy and possibly remove radiotap header
547 		 * and FCS from the original.
548 		 */
549 		skb = skb_copy_expand(origskb, needed_headroom, 0, GFP_ATOMIC);
550 
551 		origskb = remove_monitor_info(local, origskb,
552 					      rtap_vendor_space);
553 
554 		if (!skb)
555 			return origskb;
556 	}
557 
558 	/* prepend radiotap information */
559 	ieee80211_add_rx_radiotap_header(local, skb, rate, rt_hdrlen, true);
560 
561 	skb_reset_mac_header(skb);
562 	skb->ip_summed = CHECKSUM_UNNECESSARY;
563 	skb->pkt_type = PACKET_OTHERHOST;
564 	skb->protocol = htons(ETH_P_802_2);
565 
566 	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
567 		if (sdata->vif.type != NL80211_IFTYPE_MONITOR)
568 			continue;
569 
570 		if (sdata->u.mntr_flags & MONITOR_FLAG_COOK_FRAMES)
571 			continue;
572 
573 		if (!ieee80211_sdata_running(sdata))
574 			continue;
575 
576 		if (prev_dev) {
577 			skb2 = skb_clone(skb, GFP_ATOMIC);
578 			if (skb2) {
579 				skb2->dev = prev_dev;
580 				netif_receive_skb(skb2);
581 			}
582 		}
583 
584 		prev_dev = sdata->dev;
585 		ieee80211_rx_stats(sdata->dev, skb->len);
586 	}
587 
588 	if (prev_dev) {
589 		skb->dev = prev_dev;
590 		netif_receive_skb(skb);
591 	} else
592 		dev_kfree_skb(skb);
593 
594 	return origskb;
595 }
596 
597 static void ieee80211_parse_qos(struct ieee80211_rx_data *rx)
598 {
599 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
600 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
601 	int tid, seqno_idx, security_idx;
602 
603 	/* does the frame have a qos control field? */
604 	if (ieee80211_is_data_qos(hdr->frame_control)) {
605 		u8 *qc = ieee80211_get_qos_ctl(hdr);
606 		/* frame has qos control */
607 		tid = *qc & IEEE80211_QOS_CTL_TID_MASK;
608 		if (*qc & IEEE80211_QOS_CTL_A_MSDU_PRESENT)
609 			status->rx_flags |= IEEE80211_RX_AMSDU;
610 
611 		seqno_idx = tid;
612 		security_idx = tid;
613 	} else {
614 		/*
615 		 * IEEE 802.11-2007, 7.1.3.4.1 ("Sequence Number field"):
616 		 *
617 		 *	Sequence numbers for management frames, QoS data
618 		 *	frames with a broadcast/multicast address in the
619 		 *	Address 1 field, and all non-QoS data frames sent
620 		 *	by QoS STAs are assigned using an additional single
621 		 *	modulo-4096 counter, [...]
622 		 *
623 		 * We also use that counter for non-QoS STAs.
624 		 */
625 		seqno_idx = IEEE80211_NUM_TIDS;
626 		security_idx = 0;
627 		if (ieee80211_is_mgmt(hdr->frame_control))
628 			security_idx = IEEE80211_NUM_TIDS;
629 		tid = 0;
630 	}
631 
632 	rx->seqno_idx = seqno_idx;
633 	rx->security_idx = security_idx;
634 	/* Set skb->priority to 1d tag if highest order bit of TID is not set.
635 	 * For now, set skb->priority to 0 for other cases. */
636 	rx->skb->priority = (tid > 7) ? 0 : tid;
637 }
638 
639 /**
640  * DOC: Packet alignment
641  *
642  * Drivers always need to pass packets that are aligned to two-byte boundaries
643  * to the stack.
644  *
645  * Additionally, should, if possible, align the payload data in a way that
646  * guarantees that the contained IP header is aligned to a four-byte
647  * boundary. In the case of regular frames, this simply means aligning the
648  * payload to a four-byte boundary (because either the IP header is directly
649  * contained, or IV/RFC1042 headers that have a length divisible by four are
650  * in front of it).  If the payload data is not properly aligned and the
651  * architecture doesn't support efficient unaligned operations, mac80211
652  * will align the data.
653  *
654  * With A-MSDU frames, however, the payload data address must yield two modulo
655  * four because there are 14-byte 802.3 headers within the A-MSDU frames that
656  * push the IP header further back to a multiple of four again. Thankfully, the
657  * specs were sane enough this time around to require padding each A-MSDU
658  * subframe to a length that is a multiple of four.
659  *
660  * Padding like Atheros hardware adds which is between the 802.11 header and
661  * the payload is not supported, the driver is required to move the 802.11
662  * header to be directly in front of the payload in that case.
663  */
664 static void ieee80211_verify_alignment(struct ieee80211_rx_data *rx)
665 {
666 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG
667 	WARN_ON_ONCE((unsigned long)rx->skb->data & 1);
668 #endif
669 }
670 
671 
672 /* rx handlers */
673 
674 static int ieee80211_is_unicast_robust_mgmt_frame(struct sk_buff *skb)
675 {
676 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
677 
678 	if (is_multicast_ether_addr(hdr->addr1))
679 		return 0;
680 
681 	return ieee80211_is_robust_mgmt_frame(skb);
682 }
683 
684 
685 static int ieee80211_is_multicast_robust_mgmt_frame(struct sk_buff *skb)
686 {
687 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
688 
689 	if (!is_multicast_ether_addr(hdr->addr1))
690 		return 0;
691 
692 	return ieee80211_is_robust_mgmt_frame(skb);
693 }
694 
695 
696 /* Get the BIP key index from MMIE; return -1 if this is not a BIP frame */
697 static int ieee80211_get_mmie_keyidx(struct sk_buff *skb)
698 {
699 	struct ieee80211_mgmt *hdr = (struct ieee80211_mgmt *) skb->data;
700 	struct ieee80211_mmie *mmie;
701 	struct ieee80211_mmie_16 *mmie16;
702 
703 	if (skb->len < 24 + sizeof(*mmie) || !is_multicast_ether_addr(hdr->da))
704 		return -1;
705 
706 	if (!ieee80211_is_robust_mgmt_frame(skb))
707 		return -1; /* not a robust management frame */
708 
709 	mmie = (struct ieee80211_mmie *)
710 		(skb->data + skb->len - sizeof(*mmie));
711 	if (mmie->element_id == WLAN_EID_MMIE &&
712 	    mmie->length == sizeof(*mmie) - 2)
713 		return le16_to_cpu(mmie->key_id);
714 
715 	mmie16 = (struct ieee80211_mmie_16 *)
716 		(skb->data + skb->len - sizeof(*mmie16));
717 	if (skb->len >= 24 + sizeof(*mmie16) &&
718 	    mmie16->element_id == WLAN_EID_MMIE &&
719 	    mmie16->length == sizeof(*mmie16) - 2)
720 		return le16_to_cpu(mmie16->key_id);
721 
722 	return -1;
723 }
724 
725 static int ieee80211_get_cs_keyid(const struct ieee80211_cipher_scheme *cs,
726 				  struct sk_buff *skb)
727 {
728 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
729 	__le16 fc;
730 	int hdrlen;
731 	u8 keyid;
732 
733 	fc = hdr->frame_control;
734 	hdrlen = ieee80211_hdrlen(fc);
735 
736 	if (skb->len < hdrlen + cs->hdr_len)
737 		return -EINVAL;
738 
739 	skb_copy_bits(skb, hdrlen + cs->key_idx_off, &keyid, 1);
740 	keyid &= cs->key_idx_mask;
741 	keyid >>= cs->key_idx_shift;
742 
743 	return keyid;
744 }
745 
746 static ieee80211_rx_result ieee80211_rx_mesh_check(struct ieee80211_rx_data *rx)
747 {
748 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
749 	char *dev_addr = rx->sdata->vif.addr;
750 
751 	if (ieee80211_is_data(hdr->frame_control)) {
752 		if (is_multicast_ether_addr(hdr->addr1)) {
753 			if (ieee80211_has_tods(hdr->frame_control) ||
754 			    !ieee80211_has_fromds(hdr->frame_control))
755 				return RX_DROP_MONITOR;
756 			if (ether_addr_equal(hdr->addr3, dev_addr))
757 				return RX_DROP_MONITOR;
758 		} else {
759 			if (!ieee80211_has_a4(hdr->frame_control))
760 				return RX_DROP_MONITOR;
761 			if (ether_addr_equal(hdr->addr4, dev_addr))
762 				return RX_DROP_MONITOR;
763 		}
764 	}
765 
766 	/* If there is not an established peer link and this is not a peer link
767 	 * establisment frame, beacon or probe, drop the frame.
768 	 */
769 
770 	if (!rx->sta || sta_plink_state(rx->sta) != NL80211_PLINK_ESTAB) {
771 		struct ieee80211_mgmt *mgmt;
772 
773 		if (!ieee80211_is_mgmt(hdr->frame_control))
774 			return RX_DROP_MONITOR;
775 
776 		if (ieee80211_is_action(hdr->frame_control)) {
777 			u8 category;
778 
779 			/* make sure category field is present */
780 			if (rx->skb->len < IEEE80211_MIN_ACTION_SIZE)
781 				return RX_DROP_MONITOR;
782 
783 			mgmt = (struct ieee80211_mgmt *)hdr;
784 			category = mgmt->u.action.category;
785 			if (category != WLAN_CATEGORY_MESH_ACTION &&
786 			    category != WLAN_CATEGORY_SELF_PROTECTED)
787 				return RX_DROP_MONITOR;
788 			return RX_CONTINUE;
789 		}
790 
791 		if (ieee80211_is_probe_req(hdr->frame_control) ||
792 		    ieee80211_is_probe_resp(hdr->frame_control) ||
793 		    ieee80211_is_beacon(hdr->frame_control) ||
794 		    ieee80211_is_auth(hdr->frame_control))
795 			return RX_CONTINUE;
796 
797 		return RX_DROP_MONITOR;
798 	}
799 
800 	return RX_CONTINUE;
801 }
802 
803 static inline bool ieee80211_rx_reorder_ready(struct tid_ampdu_rx *tid_agg_rx,
804 					      int index)
805 {
806 	struct sk_buff_head *frames = &tid_agg_rx->reorder_buf[index];
807 	struct sk_buff *tail = skb_peek_tail(frames);
808 	struct ieee80211_rx_status *status;
809 
810 	if (tid_agg_rx->reorder_buf_filtered & BIT_ULL(index))
811 		return true;
812 
813 	if (!tail)
814 		return false;
815 
816 	status = IEEE80211_SKB_RXCB(tail);
817 	if (status->flag & RX_FLAG_AMSDU_MORE)
818 		return false;
819 
820 	return true;
821 }
822 
823 static void ieee80211_release_reorder_frame(struct ieee80211_sub_if_data *sdata,
824 					    struct tid_ampdu_rx *tid_agg_rx,
825 					    int index,
826 					    struct sk_buff_head *frames)
827 {
828 	struct sk_buff_head *skb_list = &tid_agg_rx->reorder_buf[index];
829 	struct sk_buff *skb;
830 	struct ieee80211_rx_status *status;
831 
832 	lockdep_assert_held(&tid_agg_rx->reorder_lock);
833 
834 	if (skb_queue_empty(skb_list))
835 		goto no_frame;
836 
837 	if (!ieee80211_rx_reorder_ready(tid_agg_rx, index)) {
838 		__skb_queue_purge(skb_list);
839 		goto no_frame;
840 	}
841 
842 	/* release frames from the reorder ring buffer */
843 	tid_agg_rx->stored_mpdu_num--;
844 	while ((skb = __skb_dequeue(skb_list))) {
845 		status = IEEE80211_SKB_RXCB(skb);
846 		status->rx_flags |= IEEE80211_RX_DEFERRED_RELEASE;
847 		__skb_queue_tail(frames, skb);
848 	}
849 
850 no_frame:
851 	tid_agg_rx->reorder_buf_filtered &= ~BIT_ULL(index);
852 	tid_agg_rx->head_seq_num = ieee80211_sn_inc(tid_agg_rx->head_seq_num);
853 }
854 
855 static void ieee80211_release_reorder_frames(struct ieee80211_sub_if_data *sdata,
856 					     struct tid_ampdu_rx *tid_agg_rx,
857 					     u16 head_seq_num,
858 					     struct sk_buff_head *frames)
859 {
860 	int index;
861 
862 	lockdep_assert_held(&tid_agg_rx->reorder_lock);
863 
864 	while (ieee80211_sn_less(tid_agg_rx->head_seq_num, head_seq_num)) {
865 		index = tid_agg_rx->head_seq_num % tid_agg_rx->buf_size;
866 		ieee80211_release_reorder_frame(sdata, tid_agg_rx, index,
867 						frames);
868 	}
869 }
870 
871 /*
872  * Timeout (in jiffies) for skb's that are waiting in the RX reorder buffer. If
873  * the skb was added to the buffer longer than this time ago, the earlier
874  * frames that have not yet been received are assumed to be lost and the skb
875  * can be released for processing. This may also release other skb's from the
876  * reorder buffer if there are no additional gaps between the frames.
877  *
878  * Callers must hold tid_agg_rx->reorder_lock.
879  */
880 #define HT_RX_REORDER_BUF_TIMEOUT (HZ / 10)
881 
882 static void ieee80211_sta_reorder_release(struct ieee80211_sub_if_data *sdata,
883 					  struct tid_ampdu_rx *tid_agg_rx,
884 					  struct sk_buff_head *frames)
885 {
886 	int index, i, j;
887 
888 	lockdep_assert_held(&tid_agg_rx->reorder_lock);
889 
890 	/* release the buffer until next missing frame */
891 	index = tid_agg_rx->head_seq_num % tid_agg_rx->buf_size;
892 	if (!ieee80211_rx_reorder_ready(tid_agg_rx, index) &&
893 	    tid_agg_rx->stored_mpdu_num) {
894 		/*
895 		 * No buffers ready to be released, but check whether any
896 		 * frames in the reorder buffer have timed out.
897 		 */
898 		int skipped = 1;
899 		for (j = (index + 1) % tid_agg_rx->buf_size; j != index;
900 		     j = (j + 1) % tid_agg_rx->buf_size) {
901 			if (!ieee80211_rx_reorder_ready(tid_agg_rx, j)) {
902 				skipped++;
903 				continue;
904 			}
905 			if (skipped &&
906 			    !time_after(jiffies, tid_agg_rx->reorder_time[j] +
907 					HT_RX_REORDER_BUF_TIMEOUT))
908 				goto set_release_timer;
909 
910 			/* don't leave incomplete A-MSDUs around */
911 			for (i = (index + 1) % tid_agg_rx->buf_size; i != j;
912 			     i = (i + 1) % tid_agg_rx->buf_size)
913 				__skb_queue_purge(&tid_agg_rx->reorder_buf[i]);
914 
915 			ht_dbg_ratelimited(sdata,
916 					   "release an RX reorder frame due to timeout on earlier frames\n");
917 			ieee80211_release_reorder_frame(sdata, tid_agg_rx, j,
918 							frames);
919 
920 			/*
921 			 * Increment the head seq# also for the skipped slots.
922 			 */
923 			tid_agg_rx->head_seq_num =
924 				(tid_agg_rx->head_seq_num +
925 				 skipped) & IEEE80211_SN_MASK;
926 			skipped = 0;
927 		}
928 	} else while (ieee80211_rx_reorder_ready(tid_agg_rx, index)) {
929 		ieee80211_release_reorder_frame(sdata, tid_agg_rx, index,
930 						frames);
931 		index =	tid_agg_rx->head_seq_num % tid_agg_rx->buf_size;
932 	}
933 
934 	if (tid_agg_rx->stored_mpdu_num) {
935 		j = index = tid_agg_rx->head_seq_num % tid_agg_rx->buf_size;
936 
937 		for (; j != (index - 1) % tid_agg_rx->buf_size;
938 		     j = (j + 1) % tid_agg_rx->buf_size) {
939 			if (ieee80211_rx_reorder_ready(tid_agg_rx, j))
940 				break;
941 		}
942 
943  set_release_timer:
944 
945 		if (!tid_agg_rx->removed)
946 			mod_timer(&tid_agg_rx->reorder_timer,
947 				  tid_agg_rx->reorder_time[j] + 1 +
948 				  HT_RX_REORDER_BUF_TIMEOUT);
949 	} else {
950 		del_timer(&tid_agg_rx->reorder_timer);
951 	}
952 }
953 
954 /*
955  * As this function belongs to the RX path it must be under
956  * rcu_read_lock protection. It returns false if the frame
957  * can be processed immediately, true if it was consumed.
958  */
959 static bool ieee80211_sta_manage_reorder_buf(struct ieee80211_sub_if_data *sdata,
960 					     struct tid_ampdu_rx *tid_agg_rx,
961 					     struct sk_buff *skb,
962 					     struct sk_buff_head *frames)
963 {
964 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
965 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
966 	u16 sc = le16_to_cpu(hdr->seq_ctrl);
967 	u16 mpdu_seq_num = (sc & IEEE80211_SCTL_SEQ) >> 4;
968 	u16 head_seq_num, buf_size;
969 	int index;
970 	bool ret = true;
971 
972 	spin_lock(&tid_agg_rx->reorder_lock);
973 
974 	/*
975 	 * Offloaded BA sessions have no known starting sequence number so pick
976 	 * one from first Rxed frame for this tid after BA was started.
977 	 */
978 	if (unlikely(tid_agg_rx->auto_seq)) {
979 		tid_agg_rx->auto_seq = false;
980 		tid_agg_rx->ssn = mpdu_seq_num;
981 		tid_agg_rx->head_seq_num = mpdu_seq_num;
982 	}
983 
984 	buf_size = tid_agg_rx->buf_size;
985 	head_seq_num = tid_agg_rx->head_seq_num;
986 
987 	/* frame with out of date sequence number */
988 	if (ieee80211_sn_less(mpdu_seq_num, head_seq_num)) {
989 		dev_kfree_skb(skb);
990 		goto out;
991 	}
992 
993 	/*
994 	 * If frame the sequence number exceeds our buffering window
995 	 * size release some previous frames to make room for this one.
996 	 */
997 	if (!ieee80211_sn_less(mpdu_seq_num, head_seq_num + buf_size)) {
998 		head_seq_num = ieee80211_sn_inc(
999 				ieee80211_sn_sub(mpdu_seq_num, buf_size));
1000 		/* release stored frames up to new head to stack */
1001 		ieee80211_release_reorder_frames(sdata, tid_agg_rx,
1002 						 head_seq_num, frames);
1003 	}
1004 
1005 	/* Now the new frame is always in the range of the reordering buffer */
1006 
1007 	index = mpdu_seq_num % tid_agg_rx->buf_size;
1008 
1009 	/* check if we already stored this frame */
1010 	if (ieee80211_rx_reorder_ready(tid_agg_rx, index)) {
1011 		dev_kfree_skb(skb);
1012 		goto out;
1013 	}
1014 
1015 	/*
1016 	 * If the current MPDU is in the right order and nothing else
1017 	 * is stored we can process it directly, no need to buffer it.
1018 	 * If it is first but there's something stored, we may be able
1019 	 * to release frames after this one.
1020 	 */
1021 	if (mpdu_seq_num == tid_agg_rx->head_seq_num &&
1022 	    tid_agg_rx->stored_mpdu_num == 0) {
1023 		if (!(status->flag & RX_FLAG_AMSDU_MORE))
1024 			tid_agg_rx->head_seq_num =
1025 				ieee80211_sn_inc(tid_agg_rx->head_seq_num);
1026 		ret = false;
1027 		goto out;
1028 	}
1029 
1030 	/* put the frame in the reordering buffer */
1031 	__skb_queue_tail(&tid_agg_rx->reorder_buf[index], skb);
1032 	if (!(status->flag & RX_FLAG_AMSDU_MORE)) {
1033 		tid_agg_rx->reorder_time[index] = jiffies;
1034 		tid_agg_rx->stored_mpdu_num++;
1035 		ieee80211_sta_reorder_release(sdata, tid_agg_rx, frames);
1036 	}
1037 
1038  out:
1039 	spin_unlock(&tid_agg_rx->reorder_lock);
1040 	return ret;
1041 }
1042 
1043 /*
1044  * Reorder MPDUs from A-MPDUs, keeping them on a buffer. Returns
1045  * true if the MPDU was buffered, false if it should be processed.
1046  */
1047 static void ieee80211_rx_reorder_ampdu(struct ieee80211_rx_data *rx,
1048 				       struct sk_buff_head *frames)
1049 {
1050 	struct sk_buff *skb = rx->skb;
1051 	struct ieee80211_local *local = rx->local;
1052 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
1053 	struct sta_info *sta = rx->sta;
1054 	struct tid_ampdu_rx *tid_agg_rx;
1055 	u16 sc;
1056 	u8 tid, ack_policy;
1057 
1058 	if (!ieee80211_is_data_qos(hdr->frame_control) ||
1059 	    is_multicast_ether_addr(hdr->addr1))
1060 		goto dont_reorder;
1061 
1062 	/*
1063 	 * filter the QoS data rx stream according to
1064 	 * STA/TID and check if this STA/TID is on aggregation
1065 	 */
1066 
1067 	if (!sta)
1068 		goto dont_reorder;
1069 
1070 	ack_policy = *ieee80211_get_qos_ctl(hdr) &
1071 		     IEEE80211_QOS_CTL_ACK_POLICY_MASK;
1072 	tid = *ieee80211_get_qos_ctl(hdr) & IEEE80211_QOS_CTL_TID_MASK;
1073 
1074 	tid_agg_rx = rcu_dereference(sta->ampdu_mlme.tid_rx[tid]);
1075 	if (!tid_agg_rx)
1076 		goto dont_reorder;
1077 
1078 	/* qos null data frames are excluded */
1079 	if (unlikely(hdr->frame_control & cpu_to_le16(IEEE80211_STYPE_NULLFUNC)))
1080 		goto dont_reorder;
1081 
1082 	/* not part of a BA session */
1083 	if (ack_policy != IEEE80211_QOS_CTL_ACK_POLICY_BLOCKACK &&
1084 	    ack_policy != IEEE80211_QOS_CTL_ACK_POLICY_NORMAL)
1085 		goto dont_reorder;
1086 
1087 	/* new, potentially un-ordered, ampdu frame - process it */
1088 
1089 	/* reset session timer */
1090 	if (tid_agg_rx->timeout)
1091 		tid_agg_rx->last_rx = jiffies;
1092 
1093 	/* if this mpdu is fragmented - terminate rx aggregation session */
1094 	sc = le16_to_cpu(hdr->seq_ctrl);
1095 	if (sc & IEEE80211_SCTL_FRAG) {
1096 		skb->pkt_type = IEEE80211_SDATA_QUEUE_TYPE_FRAME;
1097 		skb_queue_tail(&rx->sdata->skb_queue, skb);
1098 		ieee80211_queue_work(&local->hw, &rx->sdata->work);
1099 		return;
1100 	}
1101 
1102 	/*
1103 	 * No locking needed -- we will only ever process one
1104 	 * RX packet at a time, and thus own tid_agg_rx. All
1105 	 * other code manipulating it needs to (and does) make
1106 	 * sure that we cannot get to it any more before doing
1107 	 * anything with it.
1108 	 */
1109 	if (ieee80211_sta_manage_reorder_buf(rx->sdata, tid_agg_rx, skb,
1110 					     frames))
1111 		return;
1112 
1113  dont_reorder:
1114 	__skb_queue_tail(frames, skb);
1115 }
1116 
1117 static ieee80211_rx_result debug_noinline
1118 ieee80211_rx_h_check_dup(struct ieee80211_rx_data *rx)
1119 {
1120 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
1121 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
1122 
1123 	if (status->flag & RX_FLAG_DUP_VALIDATED)
1124 		return RX_CONTINUE;
1125 
1126 	/*
1127 	 * Drop duplicate 802.11 retransmissions
1128 	 * (IEEE 802.11-2012: 9.3.2.10 "Duplicate detection and recovery")
1129 	 */
1130 
1131 	if (rx->skb->len < 24)
1132 		return RX_CONTINUE;
1133 
1134 	if (ieee80211_is_ctl(hdr->frame_control) ||
1135 	    ieee80211_is_qos_nullfunc(hdr->frame_control) ||
1136 	    is_multicast_ether_addr(hdr->addr1))
1137 		return RX_CONTINUE;
1138 
1139 	if (!rx->sta)
1140 		return RX_CONTINUE;
1141 
1142 	if (unlikely(ieee80211_has_retry(hdr->frame_control) &&
1143 		     rx->sta->last_seq_ctrl[rx->seqno_idx] == hdr->seq_ctrl)) {
1144 		I802_DEBUG_INC(rx->local->dot11FrameDuplicateCount);
1145 		rx->sta->rx_stats.num_duplicates++;
1146 		return RX_DROP_UNUSABLE;
1147 	} else if (!(status->flag & RX_FLAG_AMSDU_MORE)) {
1148 		rx->sta->last_seq_ctrl[rx->seqno_idx] = hdr->seq_ctrl;
1149 	}
1150 
1151 	return RX_CONTINUE;
1152 }
1153 
1154 static ieee80211_rx_result debug_noinline
1155 ieee80211_rx_h_check(struct ieee80211_rx_data *rx)
1156 {
1157 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
1158 
1159 	/* Drop disallowed frame classes based on STA auth/assoc state;
1160 	 * IEEE 802.11, Chap 5.5.
1161 	 *
1162 	 * mac80211 filters only based on association state, i.e. it drops
1163 	 * Class 3 frames from not associated stations. hostapd sends
1164 	 * deauth/disassoc frames when needed. In addition, hostapd is
1165 	 * responsible for filtering on both auth and assoc states.
1166 	 */
1167 
1168 	if (ieee80211_vif_is_mesh(&rx->sdata->vif))
1169 		return ieee80211_rx_mesh_check(rx);
1170 
1171 	if (unlikely((ieee80211_is_data(hdr->frame_control) ||
1172 		      ieee80211_is_pspoll(hdr->frame_control)) &&
1173 		     rx->sdata->vif.type != NL80211_IFTYPE_ADHOC &&
1174 		     rx->sdata->vif.type != NL80211_IFTYPE_WDS &&
1175 		     rx->sdata->vif.type != NL80211_IFTYPE_OCB &&
1176 		     (!rx->sta || !test_sta_flag(rx->sta, WLAN_STA_ASSOC)))) {
1177 		/*
1178 		 * accept port control frames from the AP even when it's not
1179 		 * yet marked ASSOC to prevent a race where we don't set the
1180 		 * assoc bit quickly enough before it sends the first frame
1181 		 */
1182 		if (rx->sta && rx->sdata->vif.type == NL80211_IFTYPE_STATION &&
1183 		    ieee80211_is_data_present(hdr->frame_control)) {
1184 			unsigned int hdrlen;
1185 			__be16 ethertype;
1186 
1187 			hdrlen = ieee80211_hdrlen(hdr->frame_control);
1188 
1189 			if (rx->skb->len < hdrlen + 8)
1190 				return RX_DROP_MONITOR;
1191 
1192 			skb_copy_bits(rx->skb, hdrlen + 6, &ethertype, 2);
1193 			if (ethertype == rx->sdata->control_port_protocol)
1194 				return RX_CONTINUE;
1195 		}
1196 
1197 		if (rx->sdata->vif.type == NL80211_IFTYPE_AP &&
1198 		    cfg80211_rx_spurious_frame(rx->sdata->dev,
1199 					       hdr->addr2,
1200 					       GFP_ATOMIC))
1201 			return RX_DROP_UNUSABLE;
1202 
1203 		return RX_DROP_MONITOR;
1204 	}
1205 
1206 	return RX_CONTINUE;
1207 }
1208 
1209 
1210 static ieee80211_rx_result debug_noinline
1211 ieee80211_rx_h_check_more_data(struct ieee80211_rx_data *rx)
1212 {
1213 	struct ieee80211_local *local;
1214 	struct ieee80211_hdr *hdr;
1215 	struct sk_buff *skb;
1216 
1217 	local = rx->local;
1218 	skb = rx->skb;
1219 	hdr = (struct ieee80211_hdr *) skb->data;
1220 
1221 	if (!local->pspolling)
1222 		return RX_CONTINUE;
1223 
1224 	if (!ieee80211_has_fromds(hdr->frame_control))
1225 		/* this is not from AP */
1226 		return RX_CONTINUE;
1227 
1228 	if (!ieee80211_is_data(hdr->frame_control))
1229 		return RX_CONTINUE;
1230 
1231 	if (!ieee80211_has_moredata(hdr->frame_control)) {
1232 		/* AP has no more frames buffered for us */
1233 		local->pspolling = false;
1234 		return RX_CONTINUE;
1235 	}
1236 
1237 	/* more data bit is set, let's request a new frame from the AP */
1238 	ieee80211_send_pspoll(local, rx->sdata);
1239 
1240 	return RX_CONTINUE;
1241 }
1242 
1243 static void sta_ps_start(struct sta_info *sta)
1244 {
1245 	struct ieee80211_sub_if_data *sdata = sta->sdata;
1246 	struct ieee80211_local *local = sdata->local;
1247 	struct ps_data *ps;
1248 	int tid;
1249 
1250 	if (sta->sdata->vif.type == NL80211_IFTYPE_AP ||
1251 	    sta->sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
1252 		ps = &sdata->bss->ps;
1253 	else
1254 		return;
1255 
1256 	atomic_inc(&ps->num_sta_ps);
1257 	set_sta_flag(sta, WLAN_STA_PS_STA);
1258 	if (!ieee80211_hw_check(&local->hw, AP_LINK_PS))
1259 		drv_sta_notify(local, sdata, STA_NOTIFY_SLEEP, &sta->sta);
1260 	ps_dbg(sdata, "STA %pM aid %d enters power save mode\n",
1261 	       sta->sta.addr, sta->sta.aid);
1262 
1263 	ieee80211_clear_fast_xmit(sta);
1264 
1265 	if (!sta->sta.txq[0])
1266 		return;
1267 
1268 	for (tid = 0; tid < ARRAY_SIZE(sta->sta.txq); tid++) {
1269 		struct txq_info *txqi = to_txq_info(sta->sta.txq[tid]);
1270 
1271 		if (!skb_queue_len(&txqi->queue))
1272 			set_bit(tid, &sta->txq_buffered_tids);
1273 		else
1274 			clear_bit(tid, &sta->txq_buffered_tids);
1275 	}
1276 }
1277 
1278 static void sta_ps_end(struct sta_info *sta)
1279 {
1280 	ps_dbg(sta->sdata, "STA %pM aid %d exits power save mode\n",
1281 	       sta->sta.addr, sta->sta.aid);
1282 
1283 	if (test_sta_flag(sta, WLAN_STA_PS_DRIVER)) {
1284 		/*
1285 		 * Clear the flag only if the other one is still set
1286 		 * so that the TX path won't start TX'ing new frames
1287 		 * directly ... In the case that the driver flag isn't
1288 		 * set ieee80211_sta_ps_deliver_wakeup() will clear it.
1289 		 */
1290 		clear_sta_flag(sta, WLAN_STA_PS_STA);
1291 		ps_dbg(sta->sdata, "STA %pM aid %d driver-ps-blocked\n",
1292 		       sta->sta.addr, sta->sta.aid);
1293 		return;
1294 	}
1295 
1296 	set_sta_flag(sta, WLAN_STA_PS_DELIVER);
1297 	clear_sta_flag(sta, WLAN_STA_PS_STA);
1298 	ieee80211_sta_ps_deliver_wakeup(sta);
1299 }
1300 
1301 int ieee80211_sta_ps_transition(struct ieee80211_sta *pubsta, bool start)
1302 {
1303 	struct sta_info *sta = container_of(pubsta, struct sta_info, sta);
1304 	bool in_ps;
1305 
1306 	WARN_ON(!ieee80211_hw_check(&sta->local->hw, AP_LINK_PS));
1307 
1308 	/* Don't let the same PS state be set twice */
1309 	in_ps = test_sta_flag(sta, WLAN_STA_PS_STA);
1310 	if ((start && in_ps) || (!start && !in_ps))
1311 		return -EINVAL;
1312 
1313 	if (start)
1314 		sta_ps_start(sta);
1315 	else
1316 		sta_ps_end(sta);
1317 
1318 	return 0;
1319 }
1320 EXPORT_SYMBOL(ieee80211_sta_ps_transition);
1321 
1322 static ieee80211_rx_result debug_noinline
1323 ieee80211_rx_h_uapsd_and_pspoll(struct ieee80211_rx_data *rx)
1324 {
1325 	struct ieee80211_sub_if_data *sdata = rx->sdata;
1326 	struct ieee80211_hdr *hdr = (void *)rx->skb->data;
1327 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
1328 	int tid, ac;
1329 
1330 	if (!rx->sta)
1331 		return RX_CONTINUE;
1332 
1333 	if (sdata->vif.type != NL80211_IFTYPE_AP &&
1334 	    sdata->vif.type != NL80211_IFTYPE_AP_VLAN)
1335 		return RX_CONTINUE;
1336 
1337 	/*
1338 	 * The device handles station powersave, so don't do anything about
1339 	 * uAPSD and PS-Poll frames (the latter shouldn't even come up from
1340 	 * it to mac80211 since they're handled.)
1341 	 */
1342 	if (ieee80211_hw_check(&sdata->local->hw, AP_LINK_PS))
1343 		return RX_CONTINUE;
1344 
1345 	/*
1346 	 * Don't do anything if the station isn't already asleep. In
1347 	 * the uAPSD case, the station will probably be marked asleep,
1348 	 * in the PS-Poll case the station must be confused ...
1349 	 */
1350 	if (!test_sta_flag(rx->sta, WLAN_STA_PS_STA))
1351 		return RX_CONTINUE;
1352 
1353 	if (unlikely(ieee80211_is_pspoll(hdr->frame_control))) {
1354 		if (!test_sta_flag(rx->sta, WLAN_STA_SP)) {
1355 			if (!test_sta_flag(rx->sta, WLAN_STA_PS_DRIVER))
1356 				ieee80211_sta_ps_deliver_poll_response(rx->sta);
1357 			else
1358 				set_sta_flag(rx->sta, WLAN_STA_PSPOLL);
1359 		}
1360 
1361 		/* Free PS Poll skb here instead of returning RX_DROP that would
1362 		 * count as an dropped frame. */
1363 		dev_kfree_skb(rx->skb);
1364 
1365 		return RX_QUEUED;
1366 	} else if (!ieee80211_has_morefrags(hdr->frame_control) &&
1367 		   !(status->rx_flags & IEEE80211_RX_DEFERRED_RELEASE) &&
1368 		   ieee80211_has_pm(hdr->frame_control) &&
1369 		   (ieee80211_is_data_qos(hdr->frame_control) ||
1370 		    ieee80211_is_qos_nullfunc(hdr->frame_control))) {
1371 		tid = *ieee80211_get_qos_ctl(hdr) & IEEE80211_QOS_CTL_TID_MASK;
1372 		ac = ieee802_1d_to_ac[tid & 7];
1373 
1374 		/*
1375 		 * If this AC is not trigger-enabled do nothing.
1376 		 *
1377 		 * NB: This could/should check a separate bitmap of trigger-
1378 		 * enabled queues, but for now we only implement uAPSD w/o
1379 		 * TSPEC changes to the ACs, so they're always the same.
1380 		 */
1381 		if (!(rx->sta->sta.uapsd_queues & BIT(ac)))
1382 			return RX_CONTINUE;
1383 
1384 		/* if we are in a service period, do nothing */
1385 		if (test_sta_flag(rx->sta, WLAN_STA_SP))
1386 			return RX_CONTINUE;
1387 
1388 		if (!test_sta_flag(rx->sta, WLAN_STA_PS_DRIVER))
1389 			ieee80211_sta_ps_deliver_uapsd(rx->sta);
1390 		else
1391 			set_sta_flag(rx->sta, WLAN_STA_UAPSD);
1392 	}
1393 
1394 	return RX_CONTINUE;
1395 }
1396 
1397 static ieee80211_rx_result debug_noinline
1398 ieee80211_rx_h_sta_process(struct ieee80211_rx_data *rx)
1399 {
1400 	struct sta_info *sta = rx->sta;
1401 	struct sk_buff *skb = rx->skb;
1402 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
1403 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
1404 	int i;
1405 
1406 	if (!sta)
1407 		return RX_CONTINUE;
1408 
1409 	/*
1410 	 * Update last_rx only for IBSS packets which are for the current
1411 	 * BSSID and for station already AUTHORIZED to avoid keeping the
1412 	 * current IBSS network alive in cases where other STAs start
1413 	 * using different BSSID. This will also give the station another
1414 	 * chance to restart the authentication/authorization in case
1415 	 * something went wrong the first time.
1416 	 */
1417 	if (rx->sdata->vif.type == NL80211_IFTYPE_ADHOC) {
1418 		u8 *bssid = ieee80211_get_bssid(hdr, rx->skb->len,
1419 						NL80211_IFTYPE_ADHOC);
1420 		if (ether_addr_equal(bssid, rx->sdata->u.ibss.bssid) &&
1421 		    test_sta_flag(sta, WLAN_STA_AUTHORIZED)) {
1422 			sta->rx_stats.last_rx = jiffies;
1423 			if (ieee80211_is_data(hdr->frame_control) &&
1424 			    !is_multicast_ether_addr(hdr->addr1))
1425 				sta->rx_stats.last_rate =
1426 					sta_stats_encode_rate(status);
1427 		}
1428 	} else if (rx->sdata->vif.type == NL80211_IFTYPE_OCB) {
1429 		sta->rx_stats.last_rx = jiffies;
1430 	} else if (!is_multicast_ether_addr(hdr->addr1)) {
1431 		/*
1432 		 * Mesh beacons will update last_rx when if they are found to
1433 		 * match the current local configuration when processed.
1434 		 */
1435 		sta->rx_stats.last_rx = jiffies;
1436 		if (ieee80211_is_data(hdr->frame_control))
1437 			sta->rx_stats.last_rate = sta_stats_encode_rate(status);
1438 	}
1439 
1440 	if (rx->sdata->vif.type == NL80211_IFTYPE_STATION)
1441 		ieee80211_sta_rx_notify(rx->sdata, hdr);
1442 
1443 	sta->rx_stats.fragments++;
1444 
1445 	u64_stats_update_begin(&rx->sta->rx_stats.syncp);
1446 	sta->rx_stats.bytes += rx->skb->len;
1447 	u64_stats_update_end(&rx->sta->rx_stats.syncp);
1448 
1449 	if (!(status->flag & RX_FLAG_NO_SIGNAL_VAL)) {
1450 		sta->rx_stats.last_signal = status->signal;
1451 		ewma_signal_add(&sta->rx_stats_avg.signal, -status->signal);
1452 	}
1453 
1454 	if (status->chains) {
1455 		sta->rx_stats.chains = status->chains;
1456 		for (i = 0; i < ARRAY_SIZE(status->chain_signal); i++) {
1457 			int signal = status->chain_signal[i];
1458 
1459 			if (!(status->chains & BIT(i)))
1460 				continue;
1461 
1462 			sta->rx_stats.chain_signal_last[i] = signal;
1463 			ewma_signal_add(&sta->rx_stats_avg.chain_signal[i],
1464 					-signal);
1465 		}
1466 	}
1467 
1468 	/*
1469 	 * Change STA power saving mode only at the end of a frame
1470 	 * exchange sequence.
1471 	 */
1472 	if (!ieee80211_hw_check(&sta->local->hw, AP_LINK_PS) &&
1473 	    !ieee80211_has_morefrags(hdr->frame_control) &&
1474 	    !(status->rx_flags & IEEE80211_RX_DEFERRED_RELEASE) &&
1475 	    (rx->sdata->vif.type == NL80211_IFTYPE_AP ||
1476 	     rx->sdata->vif.type == NL80211_IFTYPE_AP_VLAN) &&
1477 	    /* PM bit is only checked in frames where it isn't reserved,
1478 	     * in AP mode it's reserved in non-bufferable management frames
1479 	     * (cf. IEEE 802.11-2012 8.2.4.1.7 Power Management field)
1480 	     */
1481 	    (!ieee80211_is_mgmt(hdr->frame_control) ||
1482 	     ieee80211_is_bufferable_mmpdu(hdr->frame_control))) {
1483 		if (test_sta_flag(sta, WLAN_STA_PS_STA)) {
1484 			if (!ieee80211_has_pm(hdr->frame_control))
1485 				sta_ps_end(sta);
1486 		} else {
1487 			if (ieee80211_has_pm(hdr->frame_control))
1488 				sta_ps_start(sta);
1489 		}
1490 	}
1491 
1492 	/* mesh power save support */
1493 	if (ieee80211_vif_is_mesh(&rx->sdata->vif))
1494 		ieee80211_mps_rx_h_sta_process(sta, hdr);
1495 
1496 	/*
1497 	 * Drop (qos-)data::nullfunc frames silently, since they
1498 	 * are used only to control station power saving mode.
1499 	 */
1500 	if (ieee80211_is_nullfunc(hdr->frame_control) ||
1501 	    ieee80211_is_qos_nullfunc(hdr->frame_control)) {
1502 		I802_DEBUG_INC(rx->local->rx_handlers_drop_nullfunc);
1503 
1504 		/*
1505 		 * If we receive a 4-addr nullfunc frame from a STA
1506 		 * that was not moved to a 4-addr STA vlan yet send
1507 		 * the event to userspace and for older hostapd drop
1508 		 * the frame to the monitor interface.
1509 		 */
1510 		if (ieee80211_has_a4(hdr->frame_control) &&
1511 		    (rx->sdata->vif.type == NL80211_IFTYPE_AP ||
1512 		     (rx->sdata->vif.type == NL80211_IFTYPE_AP_VLAN &&
1513 		      !rx->sdata->u.vlan.sta))) {
1514 			if (!test_and_set_sta_flag(sta, WLAN_STA_4ADDR_EVENT))
1515 				cfg80211_rx_unexpected_4addr_frame(
1516 					rx->sdata->dev, sta->sta.addr,
1517 					GFP_ATOMIC);
1518 			return RX_DROP_MONITOR;
1519 		}
1520 		/*
1521 		 * Update counter and free packet here to avoid
1522 		 * counting this as a dropped packed.
1523 		 */
1524 		sta->rx_stats.packets++;
1525 		dev_kfree_skb(rx->skb);
1526 		return RX_QUEUED;
1527 	}
1528 
1529 	return RX_CONTINUE;
1530 } /* ieee80211_rx_h_sta_process */
1531 
1532 static ieee80211_rx_result debug_noinline
1533 ieee80211_rx_h_decrypt(struct ieee80211_rx_data *rx)
1534 {
1535 	struct sk_buff *skb = rx->skb;
1536 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
1537 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
1538 	int keyidx;
1539 	int hdrlen;
1540 	ieee80211_rx_result result = RX_DROP_UNUSABLE;
1541 	struct ieee80211_key *sta_ptk = NULL;
1542 	int mmie_keyidx = -1;
1543 	__le16 fc;
1544 	const struct ieee80211_cipher_scheme *cs = NULL;
1545 
1546 	/*
1547 	 * Key selection 101
1548 	 *
1549 	 * There are four types of keys:
1550 	 *  - GTK (group keys)
1551 	 *  - IGTK (group keys for management frames)
1552 	 *  - PTK (pairwise keys)
1553 	 *  - STK (station-to-station pairwise keys)
1554 	 *
1555 	 * When selecting a key, we have to distinguish between multicast
1556 	 * (including broadcast) and unicast frames, the latter can only
1557 	 * use PTKs and STKs while the former always use GTKs and IGTKs.
1558 	 * Unless, of course, actual WEP keys ("pre-RSNA") are used, then
1559 	 * unicast frames can also use key indices like GTKs. Hence, if we
1560 	 * don't have a PTK/STK we check the key index for a WEP key.
1561 	 *
1562 	 * Note that in a regular BSS, multicast frames are sent by the
1563 	 * AP only, associated stations unicast the frame to the AP first
1564 	 * which then multicasts it on their behalf.
1565 	 *
1566 	 * There is also a slight problem in IBSS mode: GTKs are negotiated
1567 	 * with each station, that is something we don't currently handle.
1568 	 * The spec seems to expect that one negotiates the same key with
1569 	 * every station but there's no such requirement; VLANs could be
1570 	 * possible.
1571 	 */
1572 
1573 	/* start without a key */
1574 	rx->key = NULL;
1575 	fc = hdr->frame_control;
1576 
1577 	if (rx->sta) {
1578 		int keyid = rx->sta->ptk_idx;
1579 
1580 		if (ieee80211_has_protected(fc) && rx->sta->cipher_scheme) {
1581 			cs = rx->sta->cipher_scheme;
1582 			keyid = ieee80211_get_cs_keyid(cs, rx->skb);
1583 			if (unlikely(keyid < 0))
1584 				return RX_DROP_UNUSABLE;
1585 		}
1586 		sta_ptk = rcu_dereference(rx->sta->ptk[keyid]);
1587 	}
1588 
1589 	if (!ieee80211_has_protected(fc))
1590 		mmie_keyidx = ieee80211_get_mmie_keyidx(rx->skb);
1591 
1592 	if (!is_multicast_ether_addr(hdr->addr1) && sta_ptk) {
1593 		rx->key = sta_ptk;
1594 		if ((status->flag & RX_FLAG_DECRYPTED) &&
1595 		    (status->flag & RX_FLAG_IV_STRIPPED))
1596 			return RX_CONTINUE;
1597 		/* Skip decryption if the frame is not protected. */
1598 		if (!ieee80211_has_protected(fc))
1599 			return RX_CONTINUE;
1600 	} else if (mmie_keyidx >= 0) {
1601 		/* Broadcast/multicast robust management frame / BIP */
1602 		if ((status->flag & RX_FLAG_DECRYPTED) &&
1603 		    (status->flag & RX_FLAG_IV_STRIPPED))
1604 			return RX_CONTINUE;
1605 
1606 		if (mmie_keyidx < NUM_DEFAULT_KEYS ||
1607 		    mmie_keyidx >= NUM_DEFAULT_KEYS + NUM_DEFAULT_MGMT_KEYS)
1608 			return RX_DROP_MONITOR; /* unexpected BIP keyidx */
1609 		if (rx->sta)
1610 			rx->key = rcu_dereference(rx->sta->gtk[mmie_keyidx]);
1611 		if (!rx->key)
1612 			rx->key = rcu_dereference(rx->sdata->keys[mmie_keyidx]);
1613 	} else if (!ieee80211_has_protected(fc)) {
1614 		/*
1615 		 * The frame was not protected, so skip decryption. However, we
1616 		 * need to set rx->key if there is a key that could have been
1617 		 * used so that the frame may be dropped if encryption would
1618 		 * have been expected.
1619 		 */
1620 		struct ieee80211_key *key = NULL;
1621 		struct ieee80211_sub_if_data *sdata = rx->sdata;
1622 		int i;
1623 
1624 		if (ieee80211_is_mgmt(fc) &&
1625 		    is_multicast_ether_addr(hdr->addr1) &&
1626 		    (key = rcu_dereference(rx->sdata->default_mgmt_key)))
1627 			rx->key = key;
1628 		else {
1629 			if (rx->sta) {
1630 				for (i = 0; i < NUM_DEFAULT_KEYS; i++) {
1631 					key = rcu_dereference(rx->sta->gtk[i]);
1632 					if (key)
1633 						break;
1634 				}
1635 			}
1636 			if (!key) {
1637 				for (i = 0; i < NUM_DEFAULT_KEYS; i++) {
1638 					key = rcu_dereference(sdata->keys[i]);
1639 					if (key)
1640 						break;
1641 				}
1642 			}
1643 			if (key)
1644 				rx->key = key;
1645 		}
1646 		return RX_CONTINUE;
1647 	} else {
1648 		u8 keyid;
1649 
1650 		/*
1651 		 * The device doesn't give us the IV so we won't be
1652 		 * able to look up the key. That's ok though, we
1653 		 * don't need to decrypt the frame, we just won't
1654 		 * be able to keep statistics accurate.
1655 		 * Except for key threshold notifications, should
1656 		 * we somehow allow the driver to tell us which key
1657 		 * the hardware used if this flag is set?
1658 		 */
1659 		if ((status->flag & RX_FLAG_DECRYPTED) &&
1660 		    (status->flag & RX_FLAG_IV_STRIPPED))
1661 			return RX_CONTINUE;
1662 
1663 		hdrlen = ieee80211_hdrlen(fc);
1664 
1665 		if (cs) {
1666 			keyidx = ieee80211_get_cs_keyid(cs, rx->skb);
1667 
1668 			if (unlikely(keyidx < 0))
1669 				return RX_DROP_UNUSABLE;
1670 		} else {
1671 			if (rx->skb->len < 8 + hdrlen)
1672 				return RX_DROP_UNUSABLE; /* TODO: count this? */
1673 			/*
1674 			 * no need to call ieee80211_wep_get_keyidx,
1675 			 * it verifies a bunch of things we've done already
1676 			 */
1677 			skb_copy_bits(rx->skb, hdrlen + 3, &keyid, 1);
1678 			keyidx = keyid >> 6;
1679 		}
1680 
1681 		/* check per-station GTK first, if multicast packet */
1682 		if (is_multicast_ether_addr(hdr->addr1) && rx->sta)
1683 			rx->key = rcu_dereference(rx->sta->gtk[keyidx]);
1684 
1685 		/* if not found, try default key */
1686 		if (!rx->key) {
1687 			rx->key = rcu_dereference(rx->sdata->keys[keyidx]);
1688 
1689 			/*
1690 			 * RSNA-protected unicast frames should always be
1691 			 * sent with pairwise or station-to-station keys,
1692 			 * but for WEP we allow using a key index as well.
1693 			 */
1694 			if (rx->key &&
1695 			    rx->key->conf.cipher != WLAN_CIPHER_SUITE_WEP40 &&
1696 			    rx->key->conf.cipher != WLAN_CIPHER_SUITE_WEP104 &&
1697 			    !is_multicast_ether_addr(hdr->addr1))
1698 				rx->key = NULL;
1699 		}
1700 	}
1701 
1702 	if (rx->key) {
1703 		if (unlikely(rx->key->flags & KEY_FLAG_TAINTED))
1704 			return RX_DROP_MONITOR;
1705 
1706 		/* TODO: add threshold stuff again */
1707 	} else {
1708 		return RX_DROP_MONITOR;
1709 	}
1710 
1711 	switch (rx->key->conf.cipher) {
1712 	case WLAN_CIPHER_SUITE_WEP40:
1713 	case WLAN_CIPHER_SUITE_WEP104:
1714 		result = ieee80211_crypto_wep_decrypt(rx);
1715 		break;
1716 	case WLAN_CIPHER_SUITE_TKIP:
1717 		result = ieee80211_crypto_tkip_decrypt(rx);
1718 		break;
1719 	case WLAN_CIPHER_SUITE_CCMP:
1720 		result = ieee80211_crypto_ccmp_decrypt(
1721 			rx, IEEE80211_CCMP_MIC_LEN);
1722 		break;
1723 	case WLAN_CIPHER_SUITE_CCMP_256:
1724 		result = ieee80211_crypto_ccmp_decrypt(
1725 			rx, IEEE80211_CCMP_256_MIC_LEN);
1726 		break;
1727 	case WLAN_CIPHER_SUITE_AES_CMAC:
1728 		result = ieee80211_crypto_aes_cmac_decrypt(rx);
1729 		break;
1730 	case WLAN_CIPHER_SUITE_BIP_CMAC_256:
1731 		result = ieee80211_crypto_aes_cmac_256_decrypt(rx);
1732 		break;
1733 	case WLAN_CIPHER_SUITE_BIP_GMAC_128:
1734 	case WLAN_CIPHER_SUITE_BIP_GMAC_256:
1735 		result = ieee80211_crypto_aes_gmac_decrypt(rx);
1736 		break;
1737 	case WLAN_CIPHER_SUITE_GCMP:
1738 	case WLAN_CIPHER_SUITE_GCMP_256:
1739 		result = ieee80211_crypto_gcmp_decrypt(rx);
1740 		break;
1741 	default:
1742 		result = ieee80211_crypto_hw_decrypt(rx);
1743 	}
1744 
1745 	/* the hdr variable is invalid after the decrypt handlers */
1746 
1747 	/* either the frame has been decrypted or will be dropped */
1748 	status->flag |= RX_FLAG_DECRYPTED;
1749 
1750 	return result;
1751 }
1752 
1753 static inline struct ieee80211_fragment_entry *
1754 ieee80211_reassemble_add(struct ieee80211_sub_if_data *sdata,
1755 			 unsigned int frag, unsigned int seq, int rx_queue,
1756 			 struct sk_buff **skb)
1757 {
1758 	struct ieee80211_fragment_entry *entry;
1759 
1760 	entry = &sdata->fragments[sdata->fragment_next++];
1761 	if (sdata->fragment_next >= IEEE80211_FRAGMENT_MAX)
1762 		sdata->fragment_next = 0;
1763 
1764 	if (!skb_queue_empty(&entry->skb_list))
1765 		__skb_queue_purge(&entry->skb_list);
1766 
1767 	__skb_queue_tail(&entry->skb_list, *skb); /* no need for locking */
1768 	*skb = NULL;
1769 	entry->first_frag_time = jiffies;
1770 	entry->seq = seq;
1771 	entry->rx_queue = rx_queue;
1772 	entry->last_frag = frag;
1773 	entry->check_sequential_pn = false;
1774 	entry->extra_len = 0;
1775 
1776 	return entry;
1777 }
1778 
1779 static inline struct ieee80211_fragment_entry *
1780 ieee80211_reassemble_find(struct ieee80211_sub_if_data *sdata,
1781 			  unsigned int frag, unsigned int seq,
1782 			  int rx_queue, struct ieee80211_hdr *hdr)
1783 {
1784 	struct ieee80211_fragment_entry *entry;
1785 	int i, idx;
1786 
1787 	idx = sdata->fragment_next;
1788 	for (i = 0; i < IEEE80211_FRAGMENT_MAX; i++) {
1789 		struct ieee80211_hdr *f_hdr;
1790 
1791 		idx--;
1792 		if (idx < 0)
1793 			idx = IEEE80211_FRAGMENT_MAX - 1;
1794 
1795 		entry = &sdata->fragments[idx];
1796 		if (skb_queue_empty(&entry->skb_list) || entry->seq != seq ||
1797 		    entry->rx_queue != rx_queue ||
1798 		    entry->last_frag + 1 != frag)
1799 			continue;
1800 
1801 		f_hdr = (struct ieee80211_hdr *)entry->skb_list.next->data;
1802 
1803 		/*
1804 		 * Check ftype and addresses are equal, else check next fragment
1805 		 */
1806 		if (((hdr->frame_control ^ f_hdr->frame_control) &
1807 		     cpu_to_le16(IEEE80211_FCTL_FTYPE)) ||
1808 		    !ether_addr_equal(hdr->addr1, f_hdr->addr1) ||
1809 		    !ether_addr_equal(hdr->addr2, f_hdr->addr2))
1810 			continue;
1811 
1812 		if (time_after(jiffies, entry->first_frag_time + 2 * HZ)) {
1813 			__skb_queue_purge(&entry->skb_list);
1814 			continue;
1815 		}
1816 		return entry;
1817 	}
1818 
1819 	return NULL;
1820 }
1821 
1822 static ieee80211_rx_result debug_noinline
1823 ieee80211_rx_h_defragment(struct ieee80211_rx_data *rx)
1824 {
1825 	struct ieee80211_hdr *hdr;
1826 	u16 sc;
1827 	__le16 fc;
1828 	unsigned int frag, seq;
1829 	struct ieee80211_fragment_entry *entry;
1830 	struct sk_buff *skb;
1831 	struct ieee80211_rx_status *status;
1832 
1833 	hdr = (struct ieee80211_hdr *)rx->skb->data;
1834 	fc = hdr->frame_control;
1835 
1836 	if (ieee80211_is_ctl(fc))
1837 		return RX_CONTINUE;
1838 
1839 	sc = le16_to_cpu(hdr->seq_ctrl);
1840 	frag = sc & IEEE80211_SCTL_FRAG;
1841 
1842 	if (is_multicast_ether_addr(hdr->addr1)) {
1843 		I802_DEBUG_INC(rx->local->dot11MulticastReceivedFrameCount);
1844 		goto out_no_led;
1845 	}
1846 
1847 	if (likely(!ieee80211_has_morefrags(fc) && frag == 0))
1848 		goto out;
1849 
1850 	I802_DEBUG_INC(rx->local->rx_handlers_fragments);
1851 
1852 	if (skb_linearize(rx->skb))
1853 		return RX_DROP_UNUSABLE;
1854 
1855 	/*
1856 	 *  skb_linearize() might change the skb->data and
1857 	 *  previously cached variables (in this case, hdr) need to
1858 	 *  be refreshed with the new data.
1859 	 */
1860 	hdr = (struct ieee80211_hdr *)rx->skb->data;
1861 	seq = (sc & IEEE80211_SCTL_SEQ) >> 4;
1862 
1863 	if (frag == 0) {
1864 		/* This is the first fragment of a new frame. */
1865 		entry = ieee80211_reassemble_add(rx->sdata, frag, seq,
1866 						 rx->seqno_idx, &(rx->skb));
1867 		if (rx->key &&
1868 		    (rx->key->conf.cipher == WLAN_CIPHER_SUITE_CCMP ||
1869 		     rx->key->conf.cipher == WLAN_CIPHER_SUITE_CCMP_256 ||
1870 		     rx->key->conf.cipher == WLAN_CIPHER_SUITE_GCMP ||
1871 		     rx->key->conf.cipher == WLAN_CIPHER_SUITE_GCMP_256) &&
1872 		    ieee80211_has_protected(fc)) {
1873 			int queue = rx->security_idx;
1874 
1875 			/* Store CCMP/GCMP PN so that we can verify that the
1876 			 * next fragment has a sequential PN value.
1877 			 */
1878 			entry->check_sequential_pn = true;
1879 			memcpy(entry->last_pn,
1880 			       rx->key->u.ccmp.rx_pn[queue],
1881 			       IEEE80211_CCMP_PN_LEN);
1882 			BUILD_BUG_ON(offsetof(struct ieee80211_key,
1883 					      u.ccmp.rx_pn) !=
1884 				     offsetof(struct ieee80211_key,
1885 					      u.gcmp.rx_pn));
1886 			BUILD_BUG_ON(sizeof(rx->key->u.ccmp.rx_pn[queue]) !=
1887 				     sizeof(rx->key->u.gcmp.rx_pn[queue]));
1888 			BUILD_BUG_ON(IEEE80211_CCMP_PN_LEN !=
1889 				     IEEE80211_GCMP_PN_LEN);
1890 		}
1891 		return RX_QUEUED;
1892 	}
1893 
1894 	/* This is a fragment for a frame that should already be pending in
1895 	 * fragment cache. Add this fragment to the end of the pending entry.
1896 	 */
1897 	entry = ieee80211_reassemble_find(rx->sdata, frag, seq,
1898 					  rx->seqno_idx, hdr);
1899 	if (!entry) {
1900 		I802_DEBUG_INC(rx->local->rx_handlers_drop_defrag);
1901 		return RX_DROP_MONITOR;
1902 	}
1903 
1904 	/* "The receiver shall discard MSDUs and MMPDUs whose constituent
1905 	 *  MPDU PN values are not incrementing in steps of 1."
1906 	 * see IEEE P802.11-REVmc/D5.0, 12.5.3.4.4, item d (for CCMP)
1907 	 * and IEEE P802.11-REVmc/D5.0, 12.5.5.4.4, item d (for GCMP)
1908 	 */
1909 	if (entry->check_sequential_pn) {
1910 		int i;
1911 		u8 pn[IEEE80211_CCMP_PN_LEN], *rpn;
1912 		int queue;
1913 
1914 		if (!rx->key ||
1915 		    (rx->key->conf.cipher != WLAN_CIPHER_SUITE_CCMP &&
1916 		     rx->key->conf.cipher != WLAN_CIPHER_SUITE_CCMP_256 &&
1917 		     rx->key->conf.cipher != WLAN_CIPHER_SUITE_GCMP &&
1918 		     rx->key->conf.cipher != WLAN_CIPHER_SUITE_GCMP_256))
1919 			return RX_DROP_UNUSABLE;
1920 		memcpy(pn, entry->last_pn, IEEE80211_CCMP_PN_LEN);
1921 		for (i = IEEE80211_CCMP_PN_LEN - 1; i >= 0; i--) {
1922 			pn[i]++;
1923 			if (pn[i])
1924 				break;
1925 		}
1926 		queue = rx->security_idx;
1927 		rpn = rx->key->u.ccmp.rx_pn[queue];
1928 		if (memcmp(pn, rpn, IEEE80211_CCMP_PN_LEN))
1929 			return RX_DROP_UNUSABLE;
1930 		memcpy(entry->last_pn, pn, IEEE80211_CCMP_PN_LEN);
1931 	}
1932 
1933 	skb_pull(rx->skb, ieee80211_hdrlen(fc));
1934 	__skb_queue_tail(&entry->skb_list, rx->skb);
1935 	entry->last_frag = frag;
1936 	entry->extra_len += rx->skb->len;
1937 	if (ieee80211_has_morefrags(fc)) {
1938 		rx->skb = NULL;
1939 		return RX_QUEUED;
1940 	}
1941 
1942 	rx->skb = __skb_dequeue(&entry->skb_list);
1943 	if (skb_tailroom(rx->skb) < entry->extra_len) {
1944 		I802_DEBUG_INC(rx->local->rx_expand_skb_head_defrag);
1945 		if (unlikely(pskb_expand_head(rx->skb, 0, entry->extra_len,
1946 					      GFP_ATOMIC))) {
1947 			I802_DEBUG_INC(rx->local->rx_handlers_drop_defrag);
1948 			__skb_queue_purge(&entry->skb_list);
1949 			return RX_DROP_UNUSABLE;
1950 		}
1951 	}
1952 	while ((skb = __skb_dequeue(&entry->skb_list))) {
1953 		memcpy(skb_put(rx->skb, skb->len), skb->data, skb->len);
1954 		dev_kfree_skb(skb);
1955 	}
1956 
1957 	/* Complete frame has been reassembled - process it now */
1958 	status = IEEE80211_SKB_RXCB(rx->skb);
1959 
1960  out:
1961 	ieee80211_led_rx(rx->local);
1962  out_no_led:
1963 	if (rx->sta)
1964 		rx->sta->rx_stats.packets++;
1965 	return RX_CONTINUE;
1966 }
1967 
1968 static int ieee80211_802_1x_port_control(struct ieee80211_rx_data *rx)
1969 {
1970 	if (unlikely(!rx->sta || !test_sta_flag(rx->sta, WLAN_STA_AUTHORIZED)))
1971 		return -EACCES;
1972 
1973 	return 0;
1974 }
1975 
1976 static int ieee80211_drop_unencrypted(struct ieee80211_rx_data *rx, __le16 fc)
1977 {
1978 	struct sk_buff *skb = rx->skb;
1979 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
1980 
1981 	/*
1982 	 * Pass through unencrypted frames if the hardware has
1983 	 * decrypted them already.
1984 	 */
1985 	if (status->flag & RX_FLAG_DECRYPTED)
1986 		return 0;
1987 
1988 	/* Drop unencrypted frames if key is set. */
1989 	if (unlikely(!ieee80211_has_protected(fc) &&
1990 		     !ieee80211_is_nullfunc(fc) &&
1991 		     ieee80211_is_data(fc) && rx->key))
1992 		return -EACCES;
1993 
1994 	return 0;
1995 }
1996 
1997 static int ieee80211_drop_unencrypted_mgmt(struct ieee80211_rx_data *rx)
1998 {
1999 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
2000 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
2001 	__le16 fc = hdr->frame_control;
2002 
2003 	/*
2004 	 * Pass through unencrypted frames if the hardware has
2005 	 * decrypted them already.
2006 	 */
2007 	if (status->flag & RX_FLAG_DECRYPTED)
2008 		return 0;
2009 
2010 	if (rx->sta && test_sta_flag(rx->sta, WLAN_STA_MFP)) {
2011 		if (unlikely(!ieee80211_has_protected(fc) &&
2012 			     ieee80211_is_unicast_robust_mgmt_frame(rx->skb) &&
2013 			     rx->key)) {
2014 			if (ieee80211_is_deauth(fc) ||
2015 			    ieee80211_is_disassoc(fc))
2016 				cfg80211_rx_unprot_mlme_mgmt(rx->sdata->dev,
2017 							     rx->skb->data,
2018 							     rx->skb->len);
2019 			return -EACCES;
2020 		}
2021 		/* BIP does not use Protected field, so need to check MMIE */
2022 		if (unlikely(ieee80211_is_multicast_robust_mgmt_frame(rx->skb) &&
2023 			     ieee80211_get_mmie_keyidx(rx->skb) < 0)) {
2024 			if (ieee80211_is_deauth(fc) ||
2025 			    ieee80211_is_disassoc(fc))
2026 				cfg80211_rx_unprot_mlme_mgmt(rx->sdata->dev,
2027 							     rx->skb->data,
2028 							     rx->skb->len);
2029 			return -EACCES;
2030 		}
2031 		/*
2032 		 * When using MFP, Action frames are not allowed prior to
2033 		 * having configured keys.
2034 		 */
2035 		if (unlikely(ieee80211_is_action(fc) && !rx->key &&
2036 			     ieee80211_is_robust_mgmt_frame(rx->skb)))
2037 			return -EACCES;
2038 	}
2039 
2040 	return 0;
2041 }
2042 
2043 static int
2044 __ieee80211_data_to_8023(struct ieee80211_rx_data *rx, bool *port_control)
2045 {
2046 	struct ieee80211_sub_if_data *sdata = rx->sdata;
2047 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
2048 	bool check_port_control = false;
2049 	struct ethhdr *ehdr;
2050 	int ret;
2051 
2052 	*port_control = false;
2053 	if (ieee80211_has_a4(hdr->frame_control) &&
2054 	    sdata->vif.type == NL80211_IFTYPE_AP_VLAN && !sdata->u.vlan.sta)
2055 		return -1;
2056 
2057 	if (sdata->vif.type == NL80211_IFTYPE_STATION &&
2058 	    !!sdata->u.mgd.use_4addr != !!ieee80211_has_a4(hdr->frame_control)) {
2059 
2060 		if (!sdata->u.mgd.use_4addr)
2061 			return -1;
2062 		else
2063 			check_port_control = true;
2064 	}
2065 
2066 	if (is_multicast_ether_addr(hdr->addr1) &&
2067 	    sdata->vif.type == NL80211_IFTYPE_AP_VLAN && sdata->u.vlan.sta)
2068 		return -1;
2069 
2070 	ret = ieee80211_data_to_8023(rx->skb, sdata->vif.addr, sdata->vif.type);
2071 	if (ret < 0)
2072 		return ret;
2073 
2074 	ehdr = (struct ethhdr *) rx->skb->data;
2075 	if (ehdr->h_proto == rx->sdata->control_port_protocol)
2076 		*port_control = true;
2077 	else if (check_port_control)
2078 		return -1;
2079 
2080 	return 0;
2081 }
2082 
2083 /*
2084  * requires that rx->skb is a frame with ethernet header
2085  */
2086 static bool ieee80211_frame_allowed(struct ieee80211_rx_data *rx, __le16 fc)
2087 {
2088 	static const u8 pae_group_addr[ETH_ALEN] __aligned(2)
2089 		= { 0x01, 0x80, 0xC2, 0x00, 0x00, 0x03 };
2090 	struct ethhdr *ehdr = (struct ethhdr *) rx->skb->data;
2091 
2092 	/*
2093 	 * Allow EAPOL frames to us/the PAE group address regardless
2094 	 * of whether the frame was encrypted or not.
2095 	 */
2096 	if (ehdr->h_proto == rx->sdata->control_port_protocol &&
2097 	    (ether_addr_equal(ehdr->h_dest, rx->sdata->vif.addr) ||
2098 	     ether_addr_equal(ehdr->h_dest, pae_group_addr)))
2099 		return true;
2100 
2101 	if (ieee80211_802_1x_port_control(rx) ||
2102 	    ieee80211_drop_unencrypted(rx, fc))
2103 		return false;
2104 
2105 	return true;
2106 }
2107 
2108 /*
2109  * requires that rx->skb is a frame with ethernet header
2110  */
2111 static void
2112 ieee80211_deliver_skb(struct ieee80211_rx_data *rx)
2113 {
2114 	struct ieee80211_sub_if_data *sdata = rx->sdata;
2115 	struct net_device *dev = sdata->dev;
2116 	struct sk_buff *skb, *xmit_skb;
2117 	struct ethhdr *ehdr = (struct ethhdr *) rx->skb->data;
2118 	struct sta_info *dsta;
2119 
2120 	skb = rx->skb;
2121 	xmit_skb = NULL;
2122 
2123 	ieee80211_rx_stats(dev, skb->len);
2124 
2125 	if (rx->sta) {
2126 		/* The seqno index has the same property as needed
2127 		 * for the rx_msdu field, i.e. it is IEEE80211_NUM_TIDS
2128 		 * for non-QoS-data frames. Here we know it's a data
2129 		 * frame, so count MSDUs.
2130 		 */
2131 		u64_stats_update_begin(&rx->sta->rx_stats.syncp);
2132 		rx->sta->rx_stats.msdu[rx->seqno_idx]++;
2133 		u64_stats_update_end(&rx->sta->rx_stats.syncp);
2134 	}
2135 
2136 	if ((sdata->vif.type == NL80211_IFTYPE_AP ||
2137 	     sdata->vif.type == NL80211_IFTYPE_AP_VLAN) &&
2138 	    !(sdata->flags & IEEE80211_SDATA_DONT_BRIDGE_PACKETS) &&
2139 	    (sdata->vif.type != NL80211_IFTYPE_AP_VLAN || !sdata->u.vlan.sta)) {
2140 		if (is_multicast_ether_addr(ehdr->h_dest)) {
2141 			/*
2142 			 * send multicast frames both to higher layers in
2143 			 * local net stack and back to the wireless medium
2144 			 */
2145 			xmit_skb = skb_copy(skb, GFP_ATOMIC);
2146 			if (!xmit_skb)
2147 				net_info_ratelimited("%s: failed to clone multicast frame\n",
2148 						    dev->name);
2149 		} else {
2150 			dsta = sta_info_get(sdata, skb->data);
2151 			if (dsta) {
2152 				/*
2153 				 * The destination station is associated to
2154 				 * this AP (in this VLAN), so send the frame
2155 				 * directly to it and do not pass it to local
2156 				 * net stack.
2157 				 */
2158 				xmit_skb = skb;
2159 				skb = NULL;
2160 			}
2161 		}
2162 	}
2163 
2164 #ifndef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
2165 	if (skb) {
2166 		/* 'align' will only take the values 0 or 2 here since all
2167 		 * frames are required to be aligned to 2-byte boundaries
2168 		 * when being passed to mac80211; the code here works just
2169 		 * as well if that isn't true, but mac80211 assumes it can
2170 		 * access fields as 2-byte aligned (e.g. for ether_addr_equal)
2171 		 */
2172 		int align;
2173 
2174 		align = (unsigned long)(skb->data + sizeof(struct ethhdr)) & 3;
2175 		if (align) {
2176 			if (WARN_ON(skb_headroom(skb) < 3)) {
2177 				dev_kfree_skb(skb);
2178 				skb = NULL;
2179 			} else {
2180 				u8 *data = skb->data;
2181 				size_t len = skb_headlen(skb);
2182 				skb->data -= align;
2183 				memmove(skb->data, data, len);
2184 				skb_set_tail_pointer(skb, len);
2185 			}
2186 		}
2187 	}
2188 #endif
2189 
2190 	if (skb) {
2191 		/* deliver to local stack */
2192 		skb->protocol = eth_type_trans(skb, dev);
2193 		memset(skb->cb, 0, sizeof(skb->cb));
2194 		if (rx->napi)
2195 			napi_gro_receive(rx->napi, skb);
2196 		else
2197 			netif_receive_skb(skb);
2198 	}
2199 
2200 	if (xmit_skb) {
2201 		/*
2202 		 * Send to wireless media and increase priority by 256 to
2203 		 * keep the received priority instead of reclassifying
2204 		 * the frame (see cfg80211_classify8021d).
2205 		 */
2206 		xmit_skb->priority += 256;
2207 		xmit_skb->protocol = htons(ETH_P_802_3);
2208 		skb_reset_network_header(xmit_skb);
2209 		skb_reset_mac_header(xmit_skb);
2210 		dev_queue_xmit(xmit_skb);
2211 	}
2212 }
2213 
2214 static ieee80211_rx_result debug_noinline
2215 ieee80211_rx_h_amsdu(struct ieee80211_rx_data *rx)
2216 {
2217 	struct net_device *dev = rx->sdata->dev;
2218 	struct sk_buff *skb = rx->skb;
2219 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
2220 	__le16 fc = hdr->frame_control;
2221 	struct sk_buff_head frame_list;
2222 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
2223 
2224 	if (unlikely(!ieee80211_is_data(fc)))
2225 		return RX_CONTINUE;
2226 
2227 	if (unlikely(!ieee80211_is_data_present(fc)))
2228 		return RX_DROP_MONITOR;
2229 
2230 	if (!(status->rx_flags & IEEE80211_RX_AMSDU))
2231 		return RX_CONTINUE;
2232 
2233 	if (ieee80211_has_a4(hdr->frame_control) &&
2234 	    rx->sdata->vif.type == NL80211_IFTYPE_AP_VLAN &&
2235 	    !rx->sdata->u.vlan.sta)
2236 		return RX_DROP_UNUSABLE;
2237 
2238 	if (is_multicast_ether_addr(hdr->addr1) &&
2239 	    ((rx->sdata->vif.type == NL80211_IFTYPE_AP_VLAN &&
2240 	      rx->sdata->u.vlan.sta) ||
2241 	     (rx->sdata->vif.type == NL80211_IFTYPE_STATION &&
2242 	      rx->sdata->u.mgd.use_4addr)))
2243 		return RX_DROP_UNUSABLE;
2244 
2245 	skb->dev = dev;
2246 	__skb_queue_head_init(&frame_list);
2247 
2248 	ieee80211_amsdu_to_8023s(skb, &frame_list, dev->dev_addr,
2249 				 rx->sdata->vif.type,
2250 				 rx->local->hw.extra_tx_headroom, true);
2251 
2252 	while (!skb_queue_empty(&frame_list)) {
2253 		rx->skb = __skb_dequeue(&frame_list);
2254 
2255 		if (!ieee80211_frame_allowed(rx, fc)) {
2256 			dev_kfree_skb(rx->skb);
2257 			continue;
2258 		}
2259 
2260 		ieee80211_deliver_skb(rx);
2261 	}
2262 
2263 	return RX_QUEUED;
2264 }
2265 
2266 #ifdef CONFIG_MAC80211_MESH
2267 static ieee80211_rx_result
2268 ieee80211_rx_h_mesh_fwding(struct ieee80211_rx_data *rx)
2269 {
2270 	struct ieee80211_hdr *fwd_hdr, *hdr;
2271 	struct ieee80211_tx_info *info;
2272 	struct ieee80211s_hdr *mesh_hdr;
2273 	struct sk_buff *skb = rx->skb, *fwd_skb;
2274 	struct ieee80211_local *local = rx->local;
2275 	struct ieee80211_sub_if_data *sdata = rx->sdata;
2276 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
2277 	u16 ac, q, hdrlen;
2278 
2279 	hdr = (struct ieee80211_hdr *) skb->data;
2280 	hdrlen = ieee80211_hdrlen(hdr->frame_control);
2281 
2282 	/* make sure fixed part of mesh header is there, also checks skb len */
2283 	if (!pskb_may_pull(rx->skb, hdrlen + 6))
2284 		return RX_DROP_MONITOR;
2285 
2286 	mesh_hdr = (struct ieee80211s_hdr *) (skb->data + hdrlen);
2287 
2288 	/* make sure full mesh header is there, also checks skb len */
2289 	if (!pskb_may_pull(rx->skb,
2290 			   hdrlen + ieee80211_get_mesh_hdrlen(mesh_hdr)))
2291 		return RX_DROP_MONITOR;
2292 
2293 	/* reload pointers */
2294 	hdr = (struct ieee80211_hdr *) skb->data;
2295 	mesh_hdr = (struct ieee80211s_hdr *) (skb->data + hdrlen);
2296 
2297 	if (ieee80211_drop_unencrypted(rx, hdr->frame_control))
2298 		return RX_DROP_MONITOR;
2299 
2300 	/* frame is in RMC, don't forward */
2301 	if (ieee80211_is_data(hdr->frame_control) &&
2302 	    is_multicast_ether_addr(hdr->addr1) &&
2303 	    mesh_rmc_check(rx->sdata, hdr->addr3, mesh_hdr))
2304 		return RX_DROP_MONITOR;
2305 
2306 	if (!ieee80211_is_data(hdr->frame_control))
2307 		return RX_CONTINUE;
2308 
2309 	if (!mesh_hdr->ttl)
2310 		return RX_DROP_MONITOR;
2311 
2312 	if (mesh_hdr->flags & MESH_FLAGS_AE) {
2313 		struct mesh_path *mppath;
2314 		char *proxied_addr;
2315 		char *mpp_addr;
2316 
2317 		if (is_multicast_ether_addr(hdr->addr1)) {
2318 			mpp_addr = hdr->addr3;
2319 			proxied_addr = mesh_hdr->eaddr1;
2320 		} else if (mesh_hdr->flags & MESH_FLAGS_AE_A5_A6) {
2321 			/* has_a4 already checked in ieee80211_rx_mesh_check */
2322 			mpp_addr = hdr->addr4;
2323 			proxied_addr = mesh_hdr->eaddr2;
2324 		} else {
2325 			return RX_DROP_MONITOR;
2326 		}
2327 
2328 		rcu_read_lock();
2329 		mppath = mpp_path_lookup(sdata, proxied_addr);
2330 		if (!mppath) {
2331 			mpp_path_add(sdata, proxied_addr, mpp_addr);
2332 		} else {
2333 			spin_lock_bh(&mppath->state_lock);
2334 			if (!ether_addr_equal(mppath->mpp, mpp_addr))
2335 				memcpy(mppath->mpp, mpp_addr, ETH_ALEN);
2336 			mppath->exp_time = jiffies;
2337 			spin_unlock_bh(&mppath->state_lock);
2338 		}
2339 		rcu_read_unlock();
2340 	}
2341 
2342 	/* Frame has reached destination.  Don't forward */
2343 	if (!is_multicast_ether_addr(hdr->addr1) &&
2344 	    ether_addr_equal(sdata->vif.addr, hdr->addr3))
2345 		return RX_CONTINUE;
2346 
2347 	ac = ieee80211_select_queue_80211(sdata, skb, hdr);
2348 	q = sdata->vif.hw_queue[ac];
2349 	if (ieee80211_queue_stopped(&local->hw, q)) {
2350 		IEEE80211_IFSTA_MESH_CTR_INC(ifmsh, dropped_frames_congestion);
2351 		return RX_DROP_MONITOR;
2352 	}
2353 	skb_set_queue_mapping(skb, q);
2354 
2355 	if (!--mesh_hdr->ttl) {
2356 		IEEE80211_IFSTA_MESH_CTR_INC(ifmsh, dropped_frames_ttl);
2357 		goto out;
2358 	}
2359 
2360 	if (!ifmsh->mshcfg.dot11MeshForwarding)
2361 		goto out;
2362 
2363 	fwd_skb = skb_copy(skb, GFP_ATOMIC);
2364 	if (!fwd_skb) {
2365 		net_info_ratelimited("%s: failed to clone mesh frame\n",
2366 				    sdata->name);
2367 		goto out;
2368 	}
2369 
2370 	fwd_hdr =  (struct ieee80211_hdr *) fwd_skb->data;
2371 	fwd_hdr->frame_control &= ~cpu_to_le16(IEEE80211_FCTL_RETRY);
2372 	info = IEEE80211_SKB_CB(fwd_skb);
2373 	memset(info, 0, sizeof(*info));
2374 	info->flags |= IEEE80211_TX_INTFL_NEED_TXPROCESSING;
2375 	info->control.vif = &rx->sdata->vif;
2376 	info->control.jiffies = jiffies;
2377 	if (is_multicast_ether_addr(fwd_hdr->addr1)) {
2378 		IEEE80211_IFSTA_MESH_CTR_INC(ifmsh, fwded_mcast);
2379 		memcpy(fwd_hdr->addr2, sdata->vif.addr, ETH_ALEN);
2380 		/* update power mode indication when forwarding */
2381 		ieee80211_mps_set_frame_flags(sdata, NULL, fwd_hdr);
2382 	} else if (!mesh_nexthop_lookup(sdata, fwd_skb)) {
2383 		/* mesh power mode flags updated in mesh_nexthop_lookup */
2384 		IEEE80211_IFSTA_MESH_CTR_INC(ifmsh, fwded_unicast);
2385 	} else {
2386 		/* unable to resolve next hop */
2387 		mesh_path_error_tx(sdata, ifmsh->mshcfg.element_ttl,
2388 				   fwd_hdr->addr3, 0,
2389 				   WLAN_REASON_MESH_PATH_NOFORWARD,
2390 				   fwd_hdr->addr2);
2391 		IEEE80211_IFSTA_MESH_CTR_INC(ifmsh, dropped_frames_no_route);
2392 		kfree_skb(fwd_skb);
2393 		return RX_DROP_MONITOR;
2394 	}
2395 
2396 	IEEE80211_IFSTA_MESH_CTR_INC(ifmsh, fwded_frames);
2397 	ieee80211_add_pending_skb(local, fwd_skb);
2398  out:
2399 	if (is_multicast_ether_addr(hdr->addr1))
2400 		return RX_CONTINUE;
2401 	return RX_DROP_MONITOR;
2402 }
2403 #endif
2404 
2405 static ieee80211_rx_result debug_noinline
2406 ieee80211_rx_h_data(struct ieee80211_rx_data *rx)
2407 {
2408 	struct ieee80211_sub_if_data *sdata = rx->sdata;
2409 	struct ieee80211_local *local = rx->local;
2410 	struct net_device *dev = sdata->dev;
2411 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
2412 	__le16 fc = hdr->frame_control;
2413 	bool port_control;
2414 	int err;
2415 
2416 	if (unlikely(!ieee80211_is_data(hdr->frame_control)))
2417 		return RX_CONTINUE;
2418 
2419 	if (unlikely(!ieee80211_is_data_present(hdr->frame_control)))
2420 		return RX_DROP_MONITOR;
2421 
2422 	/*
2423 	 * Send unexpected-4addr-frame event to hostapd. For older versions,
2424 	 * also drop the frame to cooked monitor interfaces.
2425 	 */
2426 	if (ieee80211_has_a4(hdr->frame_control) &&
2427 	    sdata->vif.type == NL80211_IFTYPE_AP) {
2428 		if (rx->sta &&
2429 		    !test_and_set_sta_flag(rx->sta, WLAN_STA_4ADDR_EVENT))
2430 			cfg80211_rx_unexpected_4addr_frame(
2431 				rx->sdata->dev, rx->sta->sta.addr, GFP_ATOMIC);
2432 		return RX_DROP_MONITOR;
2433 	}
2434 
2435 	err = __ieee80211_data_to_8023(rx, &port_control);
2436 	if (unlikely(err))
2437 		return RX_DROP_UNUSABLE;
2438 
2439 	if (!ieee80211_frame_allowed(rx, fc))
2440 		return RX_DROP_MONITOR;
2441 
2442 	/* directly handle TDLS channel switch requests/responses */
2443 	if (unlikely(((struct ethhdr *)rx->skb->data)->h_proto ==
2444 						cpu_to_be16(ETH_P_TDLS))) {
2445 		struct ieee80211_tdls_data *tf = (void *)rx->skb->data;
2446 
2447 		if (pskb_may_pull(rx->skb,
2448 				  offsetof(struct ieee80211_tdls_data, u)) &&
2449 		    tf->payload_type == WLAN_TDLS_SNAP_RFTYPE &&
2450 		    tf->category == WLAN_CATEGORY_TDLS &&
2451 		    (tf->action_code == WLAN_TDLS_CHANNEL_SWITCH_REQUEST ||
2452 		     tf->action_code == WLAN_TDLS_CHANNEL_SWITCH_RESPONSE)) {
2453 			skb_queue_tail(&local->skb_queue_tdls_chsw, rx->skb);
2454 			schedule_work(&local->tdls_chsw_work);
2455 			if (rx->sta)
2456 				rx->sta->rx_stats.packets++;
2457 
2458 			return RX_QUEUED;
2459 		}
2460 	}
2461 
2462 	if (rx->sdata->vif.type == NL80211_IFTYPE_AP_VLAN &&
2463 	    unlikely(port_control) && sdata->bss) {
2464 		sdata = container_of(sdata->bss, struct ieee80211_sub_if_data,
2465 				     u.ap);
2466 		dev = sdata->dev;
2467 		rx->sdata = sdata;
2468 	}
2469 
2470 	rx->skb->dev = dev;
2471 
2472 	if (!ieee80211_hw_check(&local->hw, SUPPORTS_DYNAMIC_PS) &&
2473 	    local->ps_sdata && local->hw.conf.dynamic_ps_timeout > 0 &&
2474 	    !is_multicast_ether_addr(
2475 		    ((struct ethhdr *)rx->skb->data)->h_dest) &&
2476 	    (!local->scanning &&
2477 	     !test_bit(SDATA_STATE_OFFCHANNEL, &sdata->state)))
2478 		mod_timer(&local->dynamic_ps_timer, jiffies +
2479 			  msecs_to_jiffies(local->hw.conf.dynamic_ps_timeout));
2480 
2481 	ieee80211_deliver_skb(rx);
2482 
2483 	return RX_QUEUED;
2484 }
2485 
2486 static ieee80211_rx_result debug_noinline
2487 ieee80211_rx_h_ctrl(struct ieee80211_rx_data *rx, struct sk_buff_head *frames)
2488 {
2489 	struct sk_buff *skb = rx->skb;
2490 	struct ieee80211_bar *bar = (struct ieee80211_bar *)skb->data;
2491 	struct tid_ampdu_rx *tid_agg_rx;
2492 	u16 start_seq_num;
2493 	u16 tid;
2494 
2495 	if (likely(!ieee80211_is_ctl(bar->frame_control)))
2496 		return RX_CONTINUE;
2497 
2498 	if (ieee80211_is_back_req(bar->frame_control)) {
2499 		struct {
2500 			__le16 control, start_seq_num;
2501 		} __packed bar_data;
2502 		struct ieee80211_event event = {
2503 			.type = BAR_RX_EVENT,
2504 		};
2505 
2506 		if (!rx->sta)
2507 			return RX_DROP_MONITOR;
2508 
2509 		if (skb_copy_bits(skb, offsetof(struct ieee80211_bar, control),
2510 				  &bar_data, sizeof(bar_data)))
2511 			return RX_DROP_MONITOR;
2512 
2513 		tid = le16_to_cpu(bar_data.control) >> 12;
2514 
2515 		tid_agg_rx = rcu_dereference(rx->sta->ampdu_mlme.tid_rx[tid]);
2516 		if (!tid_agg_rx)
2517 			return RX_DROP_MONITOR;
2518 
2519 		start_seq_num = le16_to_cpu(bar_data.start_seq_num) >> 4;
2520 		event.u.ba.tid = tid;
2521 		event.u.ba.ssn = start_seq_num;
2522 		event.u.ba.sta = &rx->sta->sta;
2523 
2524 		/* reset session timer */
2525 		if (tid_agg_rx->timeout)
2526 			mod_timer(&tid_agg_rx->session_timer,
2527 				  TU_TO_EXP_TIME(tid_agg_rx->timeout));
2528 
2529 		spin_lock(&tid_agg_rx->reorder_lock);
2530 		/* release stored frames up to start of BAR */
2531 		ieee80211_release_reorder_frames(rx->sdata, tid_agg_rx,
2532 						 start_seq_num, frames);
2533 		spin_unlock(&tid_agg_rx->reorder_lock);
2534 
2535 		drv_event_callback(rx->local, rx->sdata, &event);
2536 
2537 		kfree_skb(skb);
2538 		return RX_QUEUED;
2539 	}
2540 
2541 	/*
2542 	 * After this point, we only want management frames,
2543 	 * so we can drop all remaining control frames to
2544 	 * cooked monitor interfaces.
2545 	 */
2546 	return RX_DROP_MONITOR;
2547 }
2548 
2549 static void ieee80211_process_sa_query_req(struct ieee80211_sub_if_data *sdata,
2550 					   struct ieee80211_mgmt *mgmt,
2551 					   size_t len)
2552 {
2553 	struct ieee80211_local *local = sdata->local;
2554 	struct sk_buff *skb;
2555 	struct ieee80211_mgmt *resp;
2556 
2557 	if (!ether_addr_equal(mgmt->da, sdata->vif.addr)) {
2558 		/* Not to own unicast address */
2559 		return;
2560 	}
2561 
2562 	if (!ether_addr_equal(mgmt->sa, sdata->u.mgd.bssid) ||
2563 	    !ether_addr_equal(mgmt->bssid, sdata->u.mgd.bssid)) {
2564 		/* Not from the current AP or not associated yet. */
2565 		return;
2566 	}
2567 
2568 	if (len < 24 + 1 + sizeof(resp->u.action.u.sa_query)) {
2569 		/* Too short SA Query request frame */
2570 		return;
2571 	}
2572 
2573 	skb = dev_alloc_skb(sizeof(*resp) + local->hw.extra_tx_headroom);
2574 	if (skb == NULL)
2575 		return;
2576 
2577 	skb_reserve(skb, local->hw.extra_tx_headroom);
2578 	resp = (struct ieee80211_mgmt *) skb_put(skb, 24);
2579 	memset(resp, 0, 24);
2580 	memcpy(resp->da, mgmt->sa, ETH_ALEN);
2581 	memcpy(resp->sa, sdata->vif.addr, ETH_ALEN);
2582 	memcpy(resp->bssid, sdata->u.mgd.bssid, ETH_ALEN);
2583 	resp->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
2584 					  IEEE80211_STYPE_ACTION);
2585 	skb_put(skb, 1 + sizeof(resp->u.action.u.sa_query));
2586 	resp->u.action.category = WLAN_CATEGORY_SA_QUERY;
2587 	resp->u.action.u.sa_query.action = WLAN_ACTION_SA_QUERY_RESPONSE;
2588 	memcpy(resp->u.action.u.sa_query.trans_id,
2589 	       mgmt->u.action.u.sa_query.trans_id,
2590 	       WLAN_SA_QUERY_TR_ID_LEN);
2591 
2592 	ieee80211_tx_skb(sdata, skb);
2593 }
2594 
2595 static ieee80211_rx_result debug_noinline
2596 ieee80211_rx_h_mgmt_check(struct ieee80211_rx_data *rx)
2597 {
2598 	struct ieee80211_mgmt *mgmt = (struct ieee80211_mgmt *) rx->skb->data;
2599 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
2600 
2601 	/*
2602 	 * From here on, look only at management frames.
2603 	 * Data and control frames are already handled,
2604 	 * and unknown (reserved) frames are useless.
2605 	 */
2606 	if (rx->skb->len < 24)
2607 		return RX_DROP_MONITOR;
2608 
2609 	if (!ieee80211_is_mgmt(mgmt->frame_control))
2610 		return RX_DROP_MONITOR;
2611 
2612 	if (rx->sdata->vif.type == NL80211_IFTYPE_AP &&
2613 	    ieee80211_is_beacon(mgmt->frame_control) &&
2614 	    !(rx->flags & IEEE80211_RX_BEACON_REPORTED)) {
2615 		int sig = 0;
2616 
2617 		if (ieee80211_hw_check(&rx->local->hw, SIGNAL_DBM))
2618 			sig = status->signal;
2619 
2620 		cfg80211_report_obss_beacon(rx->local->hw.wiphy,
2621 					    rx->skb->data, rx->skb->len,
2622 					    status->freq, sig);
2623 		rx->flags |= IEEE80211_RX_BEACON_REPORTED;
2624 	}
2625 
2626 	if (ieee80211_drop_unencrypted_mgmt(rx))
2627 		return RX_DROP_UNUSABLE;
2628 
2629 	return RX_CONTINUE;
2630 }
2631 
2632 static ieee80211_rx_result debug_noinline
2633 ieee80211_rx_h_action(struct ieee80211_rx_data *rx)
2634 {
2635 	struct ieee80211_local *local = rx->local;
2636 	struct ieee80211_sub_if_data *sdata = rx->sdata;
2637 	struct ieee80211_mgmt *mgmt = (struct ieee80211_mgmt *) rx->skb->data;
2638 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
2639 	int len = rx->skb->len;
2640 
2641 	if (!ieee80211_is_action(mgmt->frame_control))
2642 		return RX_CONTINUE;
2643 
2644 	/* drop too small frames */
2645 	if (len < IEEE80211_MIN_ACTION_SIZE)
2646 		return RX_DROP_UNUSABLE;
2647 
2648 	if (!rx->sta && mgmt->u.action.category != WLAN_CATEGORY_PUBLIC &&
2649 	    mgmt->u.action.category != WLAN_CATEGORY_SELF_PROTECTED &&
2650 	    mgmt->u.action.category != WLAN_CATEGORY_SPECTRUM_MGMT)
2651 		return RX_DROP_UNUSABLE;
2652 
2653 	switch (mgmt->u.action.category) {
2654 	case WLAN_CATEGORY_HT:
2655 		/* reject HT action frames from stations not supporting HT */
2656 		if (!rx->sta->sta.ht_cap.ht_supported)
2657 			goto invalid;
2658 
2659 		if (sdata->vif.type != NL80211_IFTYPE_STATION &&
2660 		    sdata->vif.type != NL80211_IFTYPE_MESH_POINT &&
2661 		    sdata->vif.type != NL80211_IFTYPE_AP_VLAN &&
2662 		    sdata->vif.type != NL80211_IFTYPE_AP &&
2663 		    sdata->vif.type != NL80211_IFTYPE_ADHOC)
2664 			break;
2665 
2666 		/* verify action & smps_control/chanwidth are present */
2667 		if (len < IEEE80211_MIN_ACTION_SIZE + 2)
2668 			goto invalid;
2669 
2670 		switch (mgmt->u.action.u.ht_smps.action) {
2671 		case WLAN_HT_ACTION_SMPS: {
2672 			struct ieee80211_supported_band *sband;
2673 			enum ieee80211_smps_mode smps_mode;
2674 
2675 			/* convert to HT capability */
2676 			switch (mgmt->u.action.u.ht_smps.smps_control) {
2677 			case WLAN_HT_SMPS_CONTROL_DISABLED:
2678 				smps_mode = IEEE80211_SMPS_OFF;
2679 				break;
2680 			case WLAN_HT_SMPS_CONTROL_STATIC:
2681 				smps_mode = IEEE80211_SMPS_STATIC;
2682 				break;
2683 			case WLAN_HT_SMPS_CONTROL_DYNAMIC:
2684 				smps_mode = IEEE80211_SMPS_DYNAMIC;
2685 				break;
2686 			default:
2687 				goto invalid;
2688 			}
2689 
2690 			/* if no change do nothing */
2691 			if (rx->sta->sta.smps_mode == smps_mode)
2692 				goto handled;
2693 			rx->sta->sta.smps_mode = smps_mode;
2694 
2695 			sband = rx->local->hw.wiphy->bands[status->band];
2696 
2697 			rate_control_rate_update(local, sband, rx->sta,
2698 						 IEEE80211_RC_SMPS_CHANGED);
2699 			goto handled;
2700 		}
2701 		case WLAN_HT_ACTION_NOTIFY_CHANWIDTH: {
2702 			struct ieee80211_supported_band *sband;
2703 			u8 chanwidth = mgmt->u.action.u.ht_notify_cw.chanwidth;
2704 			enum ieee80211_sta_rx_bandwidth max_bw, new_bw;
2705 
2706 			/* If it doesn't support 40 MHz it can't change ... */
2707 			if (!(rx->sta->sta.ht_cap.cap &
2708 					IEEE80211_HT_CAP_SUP_WIDTH_20_40))
2709 				goto handled;
2710 
2711 			if (chanwidth == IEEE80211_HT_CHANWIDTH_20MHZ)
2712 				max_bw = IEEE80211_STA_RX_BW_20;
2713 			else
2714 				max_bw = ieee80211_sta_cap_rx_bw(rx->sta);
2715 
2716 			/* set cur_max_bandwidth and recalc sta bw */
2717 			rx->sta->cur_max_bandwidth = max_bw;
2718 			new_bw = ieee80211_sta_cur_vht_bw(rx->sta);
2719 
2720 			if (rx->sta->sta.bandwidth == new_bw)
2721 				goto handled;
2722 
2723 			rx->sta->sta.bandwidth = new_bw;
2724 			sband = rx->local->hw.wiphy->bands[status->band];
2725 
2726 			rate_control_rate_update(local, sband, rx->sta,
2727 						 IEEE80211_RC_BW_CHANGED);
2728 			goto handled;
2729 		}
2730 		default:
2731 			goto invalid;
2732 		}
2733 
2734 		break;
2735 	case WLAN_CATEGORY_PUBLIC:
2736 		if (len < IEEE80211_MIN_ACTION_SIZE + 1)
2737 			goto invalid;
2738 		if (sdata->vif.type != NL80211_IFTYPE_STATION)
2739 			break;
2740 		if (!rx->sta)
2741 			break;
2742 		if (!ether_addr_equal(mgmt->bssid, sdata->u.mgd.bssid))
2743 			break;
2744 		if (mgmt->u.action.u.ext_chan_switch.action_code !=
2745 				WLAN_PUB_ACTION_EXT_CHANSW_ANN)
2746 			break;
2747 		if (len < offsetof(struct ieee80211_mgmt,
2748 				   u.action.u.ext_chan_switch.variable))
2749 			goto invalid;
2750 		goto queue;
2751 	case WLAN_CATEGORY_VHT:
2752 		if (sdata->vif.type != NL80211_IFTYPE_STATION &&
2753 		    sdata->vif.type != NL80211_IFTYPE_MESH_POINT &&
2754 		    sdata->vif.type != NL80211_IFTYPE_AP_VLAN &&
2755 		    sdata->vif.type != NL80211_IFTYPE_AP &&
2756 		    sdata->vif.type != NL80211_IFTYPE_ADHOC)
2757 			break;
2758 
2759 		/* verify action code is present */
2760 		if (len < IEEE80211_MIN_ACTION_SIZE + 1)
2761 			goto invalid;
2762 
2763 		switch (mgmt->u.action.u.vht_opmode_notif.action_code) {
2764 		case WLAN_VHT_ACTION_OPMODE_NOTIF: {
2765 			u8 opmode;
2766 
2767 			/* verify opmode is present */
2768 			if (len < IEEE80211_MIN_ACTION_SIZE + 2)
2769 				goto invalid;
2770 
2771 			opmode = mgmt->u.action.u.vht_opmode_notif.operating_mode;
2772 
2773 			ieee80211_vht_handle_opmode(rx->sdata, rx->sta,
2774 						    opmode, status->band);
2775 			goto handled;
2776 		}
2777 		case WLAN_VHT_ACTION_GROUPID_MGMT: {
2778 			if (len < IEEE80211_MIN_ACTION_SIZE + 25)
2779 				goto invalid;
2780 			goto queue;
2781 		}
2782 		default:
2783 			break;
2784 		}
2785 		break;
2786 	case WLAN_CATEGORY_BACK:
2787 		if (sdata->vif.type != NL80211_IFTYPE_STATION &&
2788 		    sdata->vif.type != NL80211_IFTYPE_MESH_POINT &&
2789 		    sdata->vif.type != NL80211_IFTYPE_AP_VLAN &&
2790 		    sdata->vif.type != NL80211_IFTYPE_AP &&
2791 		    sdata->vif.type != NL80211_IFTYPE_ADHOC)
2792 			break;
2793 
2794 		/* verify action_code is present */
2795 		if (len < IEEE80211_MIN_ACTION_SIZE + 1)
2796 			break;
2797 
2798 		switch (mgmt->u.action.u.addba_req.action_code) {
2799 		case WLAN_ACTION_ADDBA_REQ:
2800 			if (len < (IEEE80211_MIN_ACTION_SIZE +
2801 				   sizeof(mgmt->u.action.u.addba_req)))
2802 				goto invalid;
2803 			break;
2804 		case WLAN_ACTION_ADDBA_RESP:
2805 			if (len < (IEEE80211_MIN_ACTION_SIZE +
2806 				   sizeof(mgmt->u.action.u.addba_resp)))
2807 				goto invalid;
2808 			break;
2809 		case WLAN_ACTION_DELBA:
2810 			if (len < (IEEE80211_MIN_ACTION_SIZE +
2811 				   sizeof(mgmt->u.action.u.delba)))
2812 				goto invalid;
2813 			break;
2814 		default:
2815 			goto invalid;
2816 		}
2817 
2818 		goto queue;
2819 	case WLAN_CATEGORY_SPECTRUM_MGMT:
2820 		/* verify action_code is present */
2821 		if (len < IEEE80211_MIN_ACTION_SIZE + 1)
2822 			break;
2823 
2824 		switch (mgmt->u.action.u.measurement.action_code) {
2825 		case WLAN_ACTION_SPCT_MSR_REQ:
2826 			if (status->band != NL80211_BAND_5GHZ)
2827 				break;
2828 
2829 			if (len < (IEEE80211_MIN_ACTION_SIZE +
2830 				   sizeof(mgmt->u.action.u.measurement)))
2831 				break;
2832 
2833 			if (sdata->vif.type != NL80211_IFTYPE_STATION)
2834 				break;
2835 
2836 			ieee80211_process_measurement_req(sdata, mgmt, len);
2837 			goto handled;
2838 		case WLAN_ACTION_SPCT_CHL_SWITCH: {
2839 			u8 *bssid;
2840 			if (len < (IEEE80211_MIN_ACTION_SIZE +
2841 				   sizeof(mgmt->u.action.u.chan_switch)))
2842 				break;
2843 
2844 			if (sdata->vif.type != NL80211_IFTYPE_STATION &&
2845 			    sdata->vif.type != NL80211_IFTYPE_ADHOC &&
2846 			    sdata->vif.type != NL80211_IFTYPE_MESH_POINT)
2847 				break;
2848 
2849 			if (sdata->vif.type == NL80211_IFTYPE_STATION)
2850 				bssid = sdata->u.mgd.bssid;
2851 			else if (sdata->vif.type == NL80211_IFTYPE_ADHOC)
2852 				bssid = sdata->u.ibss.bssid;
2853 			else if (sdata->vif.type == NL80211_IFTYPE_MESH_POINT)
2854 				bssid = mgmt->sa;
2855 			else
2856 				break;
2857 
2858 			if (!ether_addr_equal(mgmt->bssid, bssid))
2859 				break;
2860 
2861 			goto queue;
2862 			}
2863 		}
2864 		break;
2865 	case WLAN_CATEGORY_SA_QUERY:
2866 		if (len < (IEEE80211_MIN_ACTION_SIZE +
2867 			   sizeof(mgmt->u.action.u.sa_query)))
2868 			break;
2869 
2870 		switch (mgmt->u.action.u.sa_query.action) {
2871 		case WLAN_ACTION_SA_QUERY_REQUEST:
2872 			if (sdata->vif.type != NL80211_IFTYPE_STATION)
2873 				break;
2874 			ieee80211_process_sa_query_req(sdata, mgmt, len);
2875 			goto handled;
2876 		}
2877 		break;
2878 	case WLAN_CATEGORY_SELF_PROTECTED:
2879 		if (len < (IEEE80211_MIN_ACTION_SIZE +
2880 			   sizeof(mgmt->u.action.u.self_prot.action_code)))
2881 			break;
2882 
2883 		switch (mgmt->u.action.u.self_prot.action_code) {
2884 		case WLAN_SP_MESH_PEERING_OPEN:
2885 		case WLAN_SP_MESH_PEERING_CLOSE:
2886 		case WLAN_SP_MESH_PEERING_CONFIRM:
2887 			if (!ieee80211_vif_is_mesh(&sdata->vif))
2888 				goto invalid;
2889 			if (sdata->u.mesh.user_mpm)
2890 				/* userspace handles this frame */
2891 				break;
2892 			goto queue;
2893 		case WLAN_SP_MGK_INFORM:
2894 		case WLAN_SP_MGK_ACK:
2895 			if (!ieee80211_vif_is_mesh(&sdata->vif))
2896 				goto invalid;
2897 			break;
2898 		}
2899 		break;
2900 	case WLAN_CATEGORY_MESH_ACTION:
2901 		if (len < (IEEE80211_MIN_ACTION_SIZE +
2902 			   sizeof(mgmt->u.action.u.mesh_action.action_code)))
2903 			break;
2904 
2905 		if (!ieee80211_vif_is_mesh(&sdata->vif))
2906 			break;
2907 		if (mesh_action_is_path_sel(mgmt) &&
2908 		    !mesh_path_sel_is_hwmp(sdata))
2909 			break;
2910 		goto queue;
2911 	}
2912 
2913 	return RX_CONTINUE;
2914 
2915  invalid:
2916 	status->rx_flags |= IEEE80211_RX_MALFORMED_ACTION_FRM;
2917 	/* will return in the next handlers */
2918 	return RX_CONTINUE;
2919 
2920  handled:
2921 	if (rx->sta)
2922 		rx->sta->rx_stats.packets++;
2923 	dev_kfree_skb(rx->skb);
2924 	return RX_QUEUED;
2925 
2926  queue:
2927 	rx->skb->pkt_type = IEEE80211_SDATA_QUEUE_TYPE_FRAME;
2928 	skb_queue_tail(&sdata->skb_queue, rx->skb);
2929 	ieee80211_queue_work(&local->hw, &sdata->work);
2930 	if (rx->sta)
2931 		rx->sta->rx_stats.packets++;
2932 	return RX_QUEUED;
2933 }
2934 
2935 static ieee80211_rx_result debug_noinline
2936 ieee80211_rx_h_userspace_mgmt(struct ieee80211_rx_data *rx)
2937 {
2938 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
2939 	int sig = 0;
2940 
2941 	/* skip known-bad action frames and return them in the next handler */
2942 	if (status->rx_flags & IEEE80211_RX_MALFORMED_ACTION_FRM)
2943 		return RX_CONTINUE;
2944 
2945 	/*
2946 	 * Getting here means the kernel doesn't know how to handle
2947 	 * it, but maybe userspace does ... include returned frames
2948 	 * so userspace can register for those to know whether ones
2949 	 * it transmitted were processed or returned.
2950 	 */
2951 
2952 	if (ieee80211_hw_check(&rx->local->hw, SIGNAL_DBM))
2953 		sig = status->signal;
2954 
2955 	if (cfg80211_rx_mgmt(&rx->sdata->wdev, status->freq, sig,
2956 			     rx->skb->data, rx->skb->len, 0)) {
2957 		if (rx->sta)
2958 			rx->sta->rx_stats.packets++;
2959 		dev_kfree_skb(rx->skb);
2960 		return RX_QUEUED;
2961 	}
2962 
2963 	return RX_CONTINUE;
2964 }
2965 
2966 static ieee80211_rx_result debug_noinline
2967 ieee80211_rx_h_action_return(struct ieee80211_rx_data *rx)
2968 {
2969 	struct ieee80211_local *local = rx->local;
2970 	struct ieee80211_mgmt *mgmt = (struct ieee80211_mgmt *) rx->skb->data;
2971 	struct sk_buff *nskb;
2972 	struct ieee80211_sub_if_data *sdata = rx->sdata;
2973 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
2974 
2975 	if (!ieee80211_is_action(mgmt->frame_control))
2976 		return RX_CONTINUE;
2977 
2978 	/*
2979 	 * For AP mode, hostapd is responsible for handling any action
2980 	 * frames that we didn't handle, including returning unknown
2981 	 * ones. For all other modes we will return them to the sender,
2982 	 * setting the 0x80 bit in the action category, as required by
2983 	 * 802.11-2012 9.24.4.
2984 	 * Newer versions of hostapd shall also use the management frame
2985 	 * registration mechanisms, but older ones still use cooked
2986 	 * monitor interfaces so push all frames there.
2987 	 */
2988 	if (!(status->rx_flags & IEEE80211_RX_MALFORMED_ACTION_FRM) &&
2989 	    (sdata->vif.type == NL80211_IFTYPE_AP ||
2990 	     sdata->vif.type == NL80211_IFTYPE_AP_VLAN))
2991 		return RX_DROP_MONITOR;
2992 
2993 	if (is_multicast_ether_addr(mgmt->da))
2994 		return RX_DROP_MONITOR;
2995 
2996 	/* do not return rejected action frames */
2997 	if (mgmt->u.action.category & 0x80)
2998 		return RX_DROP_UNUSABLE;
2999 
3000 	nskb = skb_copy_expand(rx->skb, local->hw.extra_tx_headroom, 0,
3001 			       GFP_ATOMIC);
3002 	if (nskb) {
3003 		struct ieee80211_mgmt *nmgmt = (void *)nskb->data;
3004 
3005 		nmgmt->u.action.category |= 0x80;
3006 		memcpy(nmgmt->da, nmgmt->sa, ETH_ALEN);
3007 		memcpy(nmgmt->sa, rx->sdata->vif.addr, ETH_ALEN);
3008 
3009 		memset(nskb->cb, 0, sizeof(nskb->cb));
3010 
3011 		if (rx->sdata->vif.type == NL80211_IFTYPE_P2P_DEVICE) {
3012 			struct ieee80211_tx_info *info = IEEE80211_SKB_CB(nskb);
3013 
3014 			info->flags = IEEE80211_TX_CTL_TX_OFFCHAN |
3015 				      IEEE80211_TX_INTFL_OFFCHAN_TX_OK |
3016 				      IEEE80211_TX_CTL_NO_CCK_RATE;
3017 			if (ieee80211_hw_check(&local->hw, QUEUE_CONTROL))
3018 				info->hw_queue =
3019 					local->hw.offchannel_tx_hw_queue;
3020 		}
3021 
3022 		__ieee80211_tx_skb_tid_band(rx->sdata, nskb, 7,
3023 					    status->band);
3024 	}
3025 	dev_kfree_skb(rx->skb);
3026 	return RX_QUEUED;
3027 }
3028 
3029 static ieee80211_rx_result debug_noinline
3030 ieee80211_rx_h_mgmt(struct ieee80211_rx_data *rx)
3031 {
3032 	struct ieee80211_sub_if_data *sdata = rx->sdata;
3033 	struct ieee80211_mgmt *mgmt = (void *)rx->skb->data;
3034 	__le16 stype;
3035 
3036 	stype = mgmt->frame_control & cpu_to_le16(IEEE80211_FCTL_STYPE);
3037 
3038 	if (!ieee80211_vif_is_mesh(&sdata->vif) &&
3039 	    sdata->vif.type != NL80211_IFTYPE_ADHOC &&
3040 	    sdata->vif.type != NL80211_IFTYPE_OCB &&
3041 	    sdata->vif.type != NL80211_IFTYPE_STATION)
3042 		return RX_DROP_MONITOR;
3043 
3044 	switch (stype) {
3045 	case cpu_to_le16(IEEE80211_STYPE_AUTH):
3046 	case cpu_to_le16(IEEE80211_STYPE_BEACON):
3047 	case cpu_to_le16(IEEE80211_STYPE_PROBE_RESP):
3048 		/* process for all: mesh, mlme, ibss */
3049 		break;
3050 	case cpu_to_le16(IEEE80211_STYPE_ASSOC_RESP):
3051 	case cpu_to_le16(IEEE80211_STYPE_REASSOC_RESP):
3052 	case cpu_to_le16(IEEE80211_STYPE_DEAUTH):
3053 	case cpu_to_le16(IEEE80211_STYPE_DISASSOC):
3054 		if (is_multicast_ether_addr(mgmt->da) &&
3055 		    !is_broadcast_ether_addr(mgmt->da))
3056 			return RX_DROP_MONITOR;
3057 
3058 		/* process only for station */
3059 		if (sdata->vif.type != NL80211_IFTYPE_STATION)
3060 			return RX_DROP_MONITOR;
3061 		break;
3062 	case cpu_to_le16(IEEE80211_STYPE_PROBE_REQ):
3063 		/* process only for ibss and mesh */
3064 		if (sdata->vif.type != NL80211_IFTYPE_ADHOC &&
3065 		    sdata->vif.type != NL80211_IFTYPE_MESH_POINT)
3066 			return RX_DROP_MONITOR;
3067 		break;
3068 	default:
3069 		return RX_DROP_MONITOR;
3070 	}
3071 
3072 	/* queue up frame and kick off work to process it */
3073 	rx->skb->pkt_type = IEEE80211_SDATA_QUEUE_TYPE_FRAME;
3074 	skb_queue_tail(&sdata->skb_queue, rx->skb);
3075 	ieee80211_queue_work(&rx->local->hw, &sdata->work);
3076 	if (rx->sta)
3077 		rx->sta->rx_stats.packets++;
3078 
3079 	return RX_QUEUED;
3080 }
3081 
3082 static void ieee80211_rx_cooked_monitor(struct ieee80211_rx_data *rx,
3083 					struct ieee80211_rate *rate)
3084 {
3085 	struct ieee80211_sub_if_data *sdata;
3086 	struct ieee80211_local *local = rx->local;
3087 	struct sk_buff *skb = rx->skb, *skb2;
3088 	struct net_device *prev_dev = NULL;
3089 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
3090 	int needed_headroom;
3091 
3092 	/*
3093 	 * If cooked monitor has been processed already, then
3094 	 * don't do it again. If not, set the flag.
3095 	 */
3096 	if (rx->flags & IEEE80211_RX_CMNTR)
3097 		goto out_free_skb;
3098 	rx->flags |= IEEE80211_RX_CMNTR;
3099 
3100 	/* If there are no cooked monitor interfaces, just free the SKB */
3101 	if (!local->cooked_mntrs)
3102 		goto out_free_skb;
3103 
3104 	/* vendor data is long removed here */
3105 	status->flag &= ~RX_FLAG_RADIOTAP_VENDOR_DATA;
3106 	/* room for the radiotap header based on driver features */
3107 	needed_headroom = ieee80211_rx_radiotap_hdrlen(local, status, skb);
3108 
3109 	if (skb_headroom(skb) < needed_headroom &&
3110 	    pskb_expand_head(skb, needed_headroom, 0, GFP_ATOMIC))
3111 		goto out_free_skb;
3112 
3113 	/* prepend radiotap information */
3114 	ieee80211_add_rx_radiotap_header(local, skb, rate, needed_headroom,
3115 					 false);
3116 
3117 	skb_reset_mac_header(skb);
3118 	skb->ip_summed = CHECKSUM_UNNECESSARY;
3119 	skb->pkt_type = PACKET_OTHERHOST;
3120 	skb->protocol = htons(ETH_P_802_2);
3121 
3122 	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
3123 		if (!ieee80211_sdata_running(sdata))
3124 			continue;
3125 
3126 		if (sdata->vif.type != NL80211_IFTYPE_MONITOR ||
3127 		    !(sdata->u.mntr_flags & MONITOR_FLAG_COOK_FRAMES))
3128 			continue;
3129 
3130 		if (prev_dev) {
3131 			skb2 = skb_clone(skb, GFP_ATOMIC);
3132 			if (skb2) {
3133 				skb2->dev = prev_dev;
3134 				netif_receive_skb(skb2);
3135 			}
3136 		}
3137 
3138 		prev_dev = sdata->dev;
3139 		ieee80211_rx_stats(sdata->dev, skb->len);
3140 	}
3141 
3142 	if (prev_dev) {
3143 		skb->dev = prev_dev;
3144 		netif_receive_skb(skb);
3145 		return;
3146 	}
3147 
3148  out_free_skb:
3149 	dev_kfree_skb(skb);
3150 }
3151 
3152 static void ieee80211_rx_handlers_result(struct ieee80211_rx_data *rx,
3153 					 ieee80211_rx_result res)
3154 {
3155 	switch (res) {
3156 	case RX_DROP_MONITOR:
3157 		I802_DEBUG_INC(rx->sdata->local->rx_handlers_drop);
3158 		if (rx->sta)
3159 			rx->sta->rx_stats.dropped++;
3160 		/* fall through */
3161 	case RX_CONTINUE: {
3162 		struct ieee80211_rate *rate = NULL;
3163 		struct ieee80211_supported_band *sband;
3164 		struct ieee80211_rx_status *status;
3165 
3166 		status = IEEE80211_SKB_RXCB((rx->skb));
3167 
3168 		sband = rx->local->hw.wiphy->bands[status->band];
3169 		if (!(status->flag & RX_FLAG_HT) &&
3170 		    !(status->flag & RX_FLAG_VHT))
3171 			rate = &sband->bitrates[status->rate_idx];
3172 
3173 		ieee80211_rx_cooked_monitor(rx, rate);
3174 		break;
3175 		}
3176 	case RX_DROP_UNUSABLE:
3177 		I802_DEBUG_INC(rx->sdata->local->rx_handlers_drop);
3178 		if (rx->sta)
3179 			rx->sta->rx_stats.dropped++;
3180 		dev_kfree_skb(rx->skb);
3181 		break;
3182 	case RX_QUEUED:
3183 		I802_DEBUG_INC(rx->sdata->local->rx_handlers_queued);
3184 		break;
3185 	}
3186 }
3187 
3188 static void ieee80211_rx_handlers(struct ieee80211_rx_data *rx,
3189 				  struct sk_buff_head *frames)
3190 {
3191 	ieee80211_rx_result res = RX_DROP_MONITOR;
3192 	struct sk_buff *skb;
3193 
3194 #define CALL_RXH(rxh)			\
3195 	do {				\
3196 		res = rxh(rx);		\
3197 		if (res != RX_CONTINUE)	\
3198 			goto rxh_next;  \
3199 	} while (0)
3200 
3201 	/* Lock here to avoid hitting all of the data used in the RX
3202 	 * path (e.g. key data, station data, ...) concurrently when
3203 	 * a frame is released from the reorder buffer due to timeout
3204 	 * from the timer, potentially concurrently with RX from the
3205 	 * driver.
3206 	 */
3207 	spin_lock_bh(&rx->local->rx_path_lock);
3208 
3209 	while ((skb = __skb_dequeue(frames))) {
3210 		/*
3211 		 * all the other fields are valid across frames
3212 		 * that belong to an aMPDU since they are on the
3213 		 * same TID from the same station
3214 		 */
3215 		rx->skb = skb;
3216 
3217 		CALL_RXH(ieee80211_rx_h_check_more_data);
3218 		CALL_RXH(ieee80211_rx_h_uapsd_and_pspoll);
3219 		CALL_RXH(ieee80211_rx_h_sta_process);
3220 		CALL_RXH(ieee80211_rx_h_decrypt);
3221 		CALL_RXH(ieee80211_rx_h_defragment);
3222 		CALL_RXH(ieee80211_rx_h_michael_mic_verify);
3223 		/* must be after MMIC verify so header is counted in MPDU mic */
3224 #ifdef CONFIG_MAC80211_MESH
3225 		if (ieee80211_vif_is_mesh(&rx->sdata->vif))
3226 			CALL_RXH(ieee80211_rx_h_mesh_fwding);
3227 #endif
3228 		CALL_RXH(ieee80211_rx_h_amsdu);
3229 		CALL_RXH(ieee80211_rx_h_data);
3230 
3231 		/* special treatment -- needs the queue */
3232 		res = ieee80211_rx_h_ctrl(rx, frames);
3233 		if (res != RX_CONTINUE)
3234 			goto rxh_next;
3235 
3236 		CALL_RXH(ieee80211_rx_h_mgmt_check);
3237 		CALL_RXH(ieee80211_rx_h_action);
3238 		CALL_RXH(ieee80211_rx_h_userspace_mgmt);
3239 		CALL_RXH(ieee80211_rx_h_action_return);
3240 		CALL_RXH(ieee80211_rx_h_mgmt);
3241 
3242  rxh_next:
3243 		ieee80211_rx_handlers_result(rx, res);
3244 
3245 #undef CALL_RXH
3246 	}
3247 
3248 	spin_unlock_bh(&rx->local->rx_path_lock);
3249 }
3250 
3251 static void ieee80211_invoke_rx_handlers(struct ieee80211_rx_data *rx)
3252 {
3253 	struct sk_buff_head reorder_release;
3254 	ieee80211_rx_result res = RX_DROP_MONITOR;
3255 
3256 	__skb_queue_head_init(&reorder_release);
3257 
3258 #define CALL_RXH(rxh)			\
3259 	do {				\
3260 		res = rxh(rx);		\
3261 		if (res != RX_CONTINUE)	\
3262 			goto rxh_next;  \
3263 	} while (0)
3264 
3265 	CALL_RXH(ieee80211_rx_h_check_dup);
3266 	CALL_RXH(ieee80211_rx_h_check);
3267 
3268 	ieee80211_rx_reorder_ampdu(rx, &reorder_release);
3269 
3270 	ieee80211_rx_handlers(rx, &reorder_release);
3271 	return;
3272 
3273  rxh_next:
3274 	ieee80211_rx_handlers_result(rx, res);
3275 
3276 #undef CALL_RXH
3277 }
3278 
3279 /*
3280  * This function makes calls into the RX path, therefore
3281  * it has to be invoked under RCU read lock.
3282  */
3283 void ieee80211_release_reorder_timeout(struct sta_info *sta, int tid)
3284 {
3285 	struct sk_buff_head frames;
3286 	struct ieee80211_rx_data rx = {
3287 		.sta = sta,
3288 		.sdata = sta->sdata,
3289 		.local = sta->local,
3290 		/* This is OK -- must be QoS data frame */
3291 		.security_idx = tid,
3292 		.seqno_idx = tid,
3293 		.napi = NULL, /* must be NULL to not have races */
3294 	};
3295 	struct tid_ampdu_rx *tid_agg_rx;
3296 
3297 	tid_agg_rx = rcu_dereference(sta->ampdu_mlme.tid_rx[tid]);
3298 	if (!tid_agg_rx)
3299 		return;
3300 
3301 	__skb_queue_head_init(&frames);
3302 
3303 	spin_lock(&tid_agg_rx->reorder_lock);
3304 	ieee80211_sta_reorder_release(sta->sdata, tid_agg_rx, &frames);
3305 	spin_unlock(&tid_agg_rx->reorder_lock);
3306 
3307 	if (!skb_queue_empty(&frames)) {
3308 		struct ieee80211_event event = {
3309 			.type = BA_FRAME_TIMEOUT,
3310 			.u.ba.tid = tid,
3311 			.u.ba.sta = &sta->sta,
3312 		};
3313 		drv_event_callback(rx.local, rx.sdata, &event);
3314 	}
3315 
3316 	ieee80211_rx_handlers(&rx, &frames);
3317 }
3318 
3319 void ieee80211_mark_rx_ba_filtered_frames(struct ieee80211_sta *pubsta, u8 tid,
3320 					  u16 ssn, u64 filtered,
3321 					  u16 received_mpdus)
3322 {
3323 	struct sta_info *sta;
3324 	struct tid_ampdu_rx *tid_agg_rx;
3325 	struct sk_buff_head frames;
3326 	struct ieee80211_rx_data rx = {
3327 		/* This is OK -- must be QoS data frame */
3328 		.security_idx = tid,
3329 		.seqno_idx = tid,
3330 	};
3331 	int i, diff;
3332 
3333 	if (WARN_ON(!pubsta || tid >= IEEE80211_NUM_TIDS))
3334 		return;
3335 
3336 	__skb_queue_head_init(&frames);
3337 
3338 	sta = container_of(pubsta, struct sta_info, sta);
3339 
3340 	rx.sta = sta;
3341 	rx.sdata = sta->sdata;
3342 	rx.local = sta->local;
3343 
3344 	rcu_read_lock();
3345 	tid_agg_rx = rcu_dereference(sta->ampdu_mlme.tid_rx[tid]);
3346 	if (!tid_agg_rx)
3347 		goto out;
3348 
3349 	spin_lock_bh(&tid_agg_rx->reorder_lock);
3350 
3351 	if (received_mpdus >= IEEE80211_SN_MODULO >> 1) {
3352 		int release;
3353 
3354 		/* release all frames in the reorder buffer */
3355 		release = (tid_agg_rx->head_seq_num + tid_agg_rx->buf_size) %
3356 			   IEEE80211_SN_MODULO;
3357 		ieee80211_release_reorder_frames(sta->sdata, tid_agg_rx,
3358 						 release, &frames);
3359 		/* update ssn to match received ssn */
3360 		tid_agg_rx->head_seq_num = ssn;
3361 	} else {
3362 		ieee80211_release_reorder_frames(sta->sdata, tid_agg_rx, ssn,
3363 						 &frames);
3364 	}
3365 
3366 	/* handle the case that received ssn is behind the mac ssn.
3367 	 * it can be tid_agg_rx->buf_size behind and still be valid */
3368 	diff = (tid_agg_rx->head_seq_num - ssn) & IEEE80211_SN_MASK;
3369 	if (diff >= tid_agg_rx->buf_size) {
3370 		tid_agg_rx->reorder_buf_filtered = 0;
3371 		goto release;
3372 	}
3373 	filtered = filtered >> diff;
3374 	ssn += diff;
3375 
3376 	/* update bitmap */
3377 	for (i = 0; i < tid_agg_rx->buf_size; i++) {
3378 		int index = (ssn + i) % tid_agg_rx->buf_size;
3379 
3380 		tid_agg_rx->reorder_buf_filtered &= ~BIT_ULL(index);
3381 		if (filtered & BIT_ULL(i))
3382 			tid_agg_rx->reorder_buf_filtered |= BIT_ULL(index);
3383 	}
3384 
3385 	/* now process also frames that the filter marking released */
3386 	ieee80211_sta_reorder_release(sta->sdata, tid_agg_rx, &frames);
3387 
3388 release:
3389 	spin_unlock_bh(&tid_agg_rx->reorder_lock);
3390 
3391 	ieee80211_rx_handlers(&rx, &frames);
3392 
3393  out:
3394 	rcu_read_unlock();
3395 }
3396 EXPORT_SYMBOL(ieee80211_mark_rx_ba_filtered_frames);
3397 
3398 /* main receive path */
3399 
3400 static bool ieee80211_accept_frame(struct ieee80211_rx_data *rx)
3401 {
3402 	struct ieee80211_sub_if_data *sdata = rx->sdata;
3403 	struct sk_buff *skb = rx->skb;
3404 	struct ieee80211_hdr *hdr = (void *)skb->data;
3405 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
3406 	u8 *bssid = ieee80211_get_bssid(hdr, skb->len, sdata->vif.type);
3407 	int multicast = is_multicast_ether_addr(hdr->addr1);
3408 
3409 	switch (sdata->vif.type) {
3410 	case NL80211_IFTYPE_STATION:
3411 		if (!bssid && !sdata->u.mgd.use_4addr)
3412 			return false;
3413 		if (multicast)
3414 			return true;
3415 		return ether_addr_equal(sdata->vif.addr, hdr->addr1);
3416 	case NL80211_IFTYPE_ADHOC:
3417 		if (!bssid)
3418 			return false;
3419 		if (ether_addr_equal(sdata->vif.addr, hdr->addr2) ||
3420 		    ether_addr_equal(sdata->u.ibss.bssid, hdr->addr2))
3421 			return false;
3422 		if (ieee80211_is_beacon(hdr->frame_control))
3423 			return true;
3424 		if (!ieee80211_bssid_match(bssid, sdata->u.ibss.bssid))
3425 			return false;
3426 		if (!multicast &&
3427 		    !ether_addr_equal(sdata->vif.addr, hdr->addr1))
3428 			return false;
3429 		if (!rx->sta) {
3430 			int rate_idx;
3431 			if (status->flag & (RX_FLAG_HT | RX_FLAG_VHT))
3432 				rate_idx = 0; /* TODO: HT/VHT rates */
3433 			else
3434 				rate_idx = status->rate_idx;
3435 			ieee80211_ibss_rx_no_sta(sdata, bssid, hdr->addr2,
3436 						 BIT(rate_idx));
3437 		}
3438 		return true;
3439 	case NL80211_IFTYPE_OCB:
3440 		if (!bssid)
3441 			return false;
3442 		if (!ieee80211_is_data_present(hdr->frame_control))
3443 			return false;
3444 		if (!is_broadcast_ether_addr(bssid))
3445 			return false;
3446 		if (!multicast &&
3447 		    !ether_addr_equal(sdata->dev->dev_addr, hdr->addr1))
3448 			return false;
3449 		if (!rx->sta) {
3450 			int rate_idx;
3451 			if (status->flag & RX_FLAG_HT)
3452 				rate_idx = 0; /* TODO: HT rates */
3453 			else
3454 				rate_idx = status->rate_idx;
3455 			ieee80211_ocb_rx_no_sta(sdata, bssid, hdr->addr2,
3456 						BIT(rate_idx));
3457 		}
3458 		return true;
3459 	case NL80211_IFTYPE_MESH_POINT:
3460 		if (multicast)
3461 			return true;
3462 		return ether_addr_equal(sdata->vif.addr, hdr->addr1);
3463 	case NL80211_IFTYPE_AP_VLAN:
3464 	case NL80211_IFTYPE_AP:
3465 		if (!bssid)
3466 			return ether_addr_equal(sdata->vif.addr, hdr->addr1);
3467 
3468 		if (!ieee80211_bssid_match(bssid, sdata->vif.addr)) {
3469 			/*
3470 			 * Accept public action frames even when the
3471 			 * BSSID doesn't match, this is used for P2P
3472 			 * and location updates. Note that mac80211
3473 			 * itself never looks at these frames.
3474 			 */
3475 			if (!multicast &&
3476 			    !ether_addr_equal(sdata->vif.addr, hdr->addr1))
3477 				return false;
3478 			if (ieee80211_is_public_action(hdr, skb->len))
3479 				return true;
3480 			return ieee80211_is_beacon(hdr->frame_control);
3481 		}
3482 
3483 		if (!ieee80211_has_tods(hdr->frame_control)) {
3484 			/* ignore data frames to TDLS-peers */
3485 			if (ieee80211_is_data(hdr->frame_control))
3486 				return false;
3487 			/* ignore action frames to TDLS-peers */
3488 			if (ieee80211_is_action(hdr->frame_control) &&
3489 			    !is_broadcast_ether_addr(bssid) &&
3490 			    !ether_addr_equal(bssid, hdr->addr1))
3491 				return false;
3492 		}
3493 		return true;
3494 	case NL80211_IFTYPE_WDS:
3495 		if (bssid || !ieee80211_is_data(hdr->frame_control))
3496 			return false;
3497 		return ether_addr_equal(sdata->u.wds.remote_addr, hdr->addr2);
3498 	case NL80211_IFTYPE_P2P_DEVICE:
3499 		return ieee80211_is_public_action(hdr, skb->len) ||
3500 		       ieee80211_is_probe_req(hdr->frame_control) ||
3501 		       ieee80211_is_probe_resp(hdr->frame_control) ||
3502 		       ieee80211_is_beacon(hdr->frame_control);
3503 	default:
3504 		break;
3505 	}
3506 
3507 	WARN_ON_ONCE(1);
3508 	return false;
3509 }
3510 
3511 void ieee80211_check_fast_rx(struct sta_info *sta)
3512 {
3513 	struct ieee80211_sub_if_data *sdata = sta->sdata;
3514 	struct ieee80211_local *local = sdata->local;
3515 	struct ieee80211_key *key;
3516 	struct ieee80211_fast_rx fastrx = {
3517 		.dev = sdata->dev,
3518 		.vif_type = sdata->vif.type,
3519 		.control_port_protocol = sdata->control_port_protocol,
3520 	}, *old, *new = NULL;
3521 	bool assign = false;
3522 
3523 	/* use sparse to check that we don't return without updating */
3524 	__acquire(check_fast_rx);
3525 
3526 	BUILD_BUG_ON(sizeof(fastrx.rfc1042_hdr) != sizeof(rfc1042_header));
3527 	BUILD_BUG_ON(sizeof(fastrx.rfc1042_hdr) != ETH_ALEN);
3528 	ether_addr_copy(fastrx.rfc1042_hdr, rfc1042_header);
3529 	ether_addr_copy(fastrx.vif_addr, sdata->vif.addr);
3530 
3531 	fastrx.uses_rss = ieee80211_hw_check(&local->hw, USES_RSS);
3532 
3533 	/* fast-rx doesn't do reordering */
3534 	if (ieee80211_hw_check(&local->hw, AMPDU_AGGREGATION) &&
3535 	    !ieee80211_hw_check(&local->hw, SUPPORTS_REORDERING_BUFFER))
3536 		goto clear;
3537 
3538 	switch (sdata->vif.type) {
3539 	case NL80211_IFTYPE_STATION:
3540 		/* 4-addr is harder to deal with, later maybe */
3541 		if (sdata->u.mgd.use_4addr)
3542 			goto clear;
3543 		/* software powersave is a huge mess, avoid all of it */
3544 		if (ieee80211_hw_check(&local->hw, PS_NULLFUNC_STACK))
3545 			goto clear;
3546 		if (ieee80211_hw_check(&local->hw, SUPPORTS_PS) &&
3547 		    !ieee80211_hw_check(&local->hw, SUPPORTS_DYNAMIC_PS))
3548 			goto clear;
3549 		if (sta->sta.tdls) {
3550 			fastrx.da_offs = offsetof(struct ieee80211_hdr, addr1);
3551 			fastrx.sa_offs = offsetof(struct ieee80211_hdr, addr2);
3552 			fastrx.expected_ds_bits = 0;
3553 		} else {
3554 			fastrx.sta_notify = sdata->u.mgd.probe_send_count > 0;
3555 			fastrx.da_offs = offsetof(struct ieee80211_hdr, addr1);
3556 			fastrx.sa_offs = offsetof(struct ieee80211_hdr, addr3);
3557 			fastrx.expected_ds_bits =
3558 				cpu_to_le16(IEEE80211_FCTL_FROMDS);
3559 		}
3560 		break;
3561 	case NL80211_IFTYPE_AP_VLAN:
3562 	case NL80211_IFTYPE_AP:
3563 		/* parallel-rx requires this, at least with calls to
3564 		 * ieee80211_sta_ps_transition()
3565 		 */
3566 		if (!ieee80211_hw_check(&local->hw, AP_LINK_PS))
3567 			goto clear;
3568 		fastrx.da_offs = offsetof(struct ieee80211_hdr, addr3);
3569 		fastrx.sa_offs = offsetof(struct ieee80211_hdr, addr2);
3570 		fastrx.expected_ds_bits = cpu_to_le16(IEEE80211_FCTL_TODS);
3571 
3572 		fastrx.internal_forward =
3573 			!(sdata->flags & IEEE80211_SDATA_DONT_BRIDGE_PACKETS) &&
3574 			(sdata->vif.type != NL80211_IFTYPE_AP_VLAN ||
3575 			 !sdata->u.vlan.sta);
3576 		break;
3577 	default:
3578 		goto clear;
3579 	}
3580 
3581 	if (!test_sta_flag(sta, WLAN_STA_AUTHORIZED))
3582 		goto clear;
3583 
3584 	rcu_read_lock();
3585 	key = rcu_dereference(sta->ptk[sta->ptk_idx]);
3586 	if (key) {
3587 		switch (key->conf.cipher) {
3588 		case WLAN_CIPHER_SUITE_TKIP:
3589 			/* we don't want to deal with MMIC in fast-rx */
3590 			goto clear_rcu;
3591 		case WLAN_CIPHER_SUITE_CCMP:
3592 		case WLAN_CIPHER_SUITE_CCMP_256:
3593 		case WLAN_CIPHER_SUITE_GCMP:
3594 		case WLAN_CIPHER_SUITE_GCMP_256:
3595 			break;
3596 		default:
3597 			/* we also don't want to deal with WEP or cipher scheme
3598 			 * since those require looking up the key idx in the
3599 			 * frame, rather than assuming the PTK is used
3600 			 * (we need to revisit this once we implement the real
3601 			 * PTK index, which is now valid in the spec, but we
3602 			 * haven't implemented that part yet)
3603 			 */
3604 			goto clear_rcu;
3605 		}
3606 
3607 		fastrx.key = true;
3608 		fastrx.icv_len = key->conf.icv_len;
3609 	}
3610 
3611 	assign = true;
3612  clear_rcu:
3613 	rcu_read_unlock();
3614  clear:
3615 	__release(check_fast_rx);
3616 
3617 	if (assign)
3618 		new = kmemdup(&fastrx, sizeof(fastrx), GFP_KERNEL);
3619 
3620 	spin_lock_bh(&sta->lock);
3621 	old = rcu_dereference_protected(sta->fast_rx, true);
3622 	rcu_assign_pointer(sta->fast_rx, new);
3623 	spin_unlock_bh(&sta->lock);
3624 
3625 	if (old)
3626 		kfree_rcu(old, rcu_head);
3627 }
3628 
3629 void ieee80211_clear_fast_rx(struct sta_info *sta)
3630 {
3631 	struct ieee80211_fast_rx *old;
3632 
3633 	spin_lock_bh(&sta->lock);
3634 	old = rcu_dereference_protected(sta->fast_rx, true);
3635 	RCU_INIT_POINTER(sta->fast_rx, NULL);
3636 	spin_unlock_bh(&sta->lock);
3637 
3638 	if (old)
3639 		kfree_rcu(old, rcu_head);
3640 }
3641 
3642 void __ieee80211_check_fast_rx_iface(struct ieee80211_sub_if_data *sdata)
3643 {
3644 	struct ieee80211_local *local = sdata->local;
3645 	struct sta_info *sta;
3646 
3647 	lockdep_assert_held(&local->sta_mtx);
3648 
3649 	list_for_each_entry_rcu(sta, &local->sta_list, list) {
3650 		if (sdata != sta->sdata &&
3651 		    (!sta->sdata->bss || sta->sdata->bss != sdata->bss))
3652 			continue;
3653 		ieee80211_check_fast_rx(sta);
3654 	}
3655 }
3656 
3657 void ieee80211_check_fast_rx_iface(struct ieee80211_sub_if_data *sdata)
3658 {
3659 	struct ieee80211_local *local = sdata->local;
3660 
3661 	mutex_lock(&local->sta_mtx);
3662 	__ieee80211_check_fast_rx_iface(sdata);
3663 	mutex_unlock(&local->sta_mtx);
3664 }
3665 
3666 static bool ieee80211_invoke_fast_rx(struct ieee80211_rx_data *rx,
3667 				     struct ieee80211_fast_rx *fast_rx)
3668 {
3669 	struct sk_buff *skb = rx->skb;
3670 	struct ieee80211_hdr *hdr = (void *)skb->data;
3671 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
3672 	struct sta_info *sta = rx->sta;
3673 	int orig_len = skb->len;
3674 	int snap_offs = ieee80211_hdrlen(hdr->frame_control);
3675 	struct {
3676 		u8 snap[sizeof(rfc1042_header)];
3677 		__be16 proto;
3678 	} *payload __aligned(2);
3679 	struct {
3680 		u8 da[ETH_ALEN];
3681 		u8 sa[ETH_ALEN];
3682 	} addrs __aligned(2);
3683 	struct ieee80211_sta_rx_stats *stats = &sta->rx_stats;
3684 
3685 	if (fast_rx->uses_rss)
3686 		stats = this_cpu_ptr(sta->pcpu_rx_stats);
3687 
3688 	/* for parallel-rx, we need to have DUP_VALIDATED, otherwise we write
3689 	 * to a common data structure; drivers can implement that per queue
3690 	 * but we don't have that information in mac80211
3691 	 */
3692 	if (!(status->flag & RX_FLAG_DUP_VALIDATED))
3693 		return false;
3694 
3695 #define FAST_RX_CRYPT_FLAGS	(RX_FLAG_PN_VALIDATED | RX_FLAG_DECRYPTED)
3696 
3697 	/* If using encryption, we also need to have:
3698 	 *  - PN_VALIDATED: similar, but the implementation is tricky
3699 	 *  - DECRYPTED: necessary for PN_VALIDATED
3700 	 */
3701 	if (fast_rx->key &&
3702 	    (status->flag & FAST_RX_CRYPT_FLAGS) != FAST_RX_CRYPT_FLAGS)
3703 		return false;
3704 
3705 	/* we don't deal with A-MSDU deaggregation here */
3706 	if (status->rx_flags & IEEE80211_RX_AMSDU)
3707 		return false;
3708 
3709 	if (unlikely(!ieee80211_is_data_present(hdr->frame_control)))
3710 		return false;
3711 
3712 	if (unlikely(ieee80211_is_frag(hdr)))
3713 		return false;
3714 
3715 	/* Since our interface address cannot be multicast, this
3716 	 * implicitly also rejects multicast frames without the
3717 	 * explicit check.
3718 	 *
3719 	 * We shouldn't get any *data* frames not addressed to us
3720 	 * (AP mode will accept multicast *management* frames), but
3721 	 * punting here will make it go through the full checks in
3722 	 * ieee80211_accept_frame().
3723 	 */
3724 	if (!ether_addr_equal(fast_rx->vif_addr, hdr->addr1))
3725 		return false;
3726 
3727 	if ((hdr->frame_control & cpu_to_le16(IEEE80211_FCTL_FROMDS |
3728 					      IEEE80211_FCTL_TODS)) !=
3729 	    fast_rx->expected_ds_bits)
3730 		goto drop;
3731 
3732 	/* assign the key to drop unencrypted frames (later)
3733 	 * and strip the IV/MIC if necessary
3734 	 */
3735 	if (fast_rx->key && !(status->flag & RX_FLAG_IV_STRIPPED)) {
3736 		/* GCMP header length is the same */
3737 		snap_offs += IEEE80211_CCMP_HDR_LEN;
3738 	}
3739 
3740 	if (!pskb_may_pull(skb, snap_offs + sizeof(*payload)))
3741 		goto drop;
3742 	payload = (void *)(skb->data + snap_offs);
3743 
3744 	if (!ether_addr_equal(payload->snap, fast_rx->rfc1042_hdr))
3745 		return false;
3746 
3747 	/* Don't handle these here since they require special code.
3748 	 * Accept AARP and IPX even though they should come with a
3749 	 * bridge-tunnel header - but if we get them this way then
3750 	 * there's little point in discarding them.
3751 	 */
3752 	if (unlikely(payload->proto == cpu_to_be16(ETH_P_TDLS) ||
3753 		     payload->proto == fast_rx->control_port_protocol))
3754 		return false;
3755 
3756 	/* after this point, don't punt to the slowpath! */
3757 
3758 	if (rx->key && !(status->flag & RX_FLAG_MIC_STRIPPED) &&
3759 	    pskb_trim(skb, skb->len - fast_rx->icv_len))
3760 		goto drop;
3761 
3762 	if (unlikely(fast_rx->sta_notify)) {
3763 		ieee80211_sta_rx_notify(rx->sdata, hdr);
3764 		fast_rx->sta_notify = false;
3765 	}
3766 
3767 	/* statistics part of ieee80211_rx_h_sta_process() */
3768 	stats->last_rx = jiffies;
3769 	stats->last_rate = sta_stats_encode_rate(status);
3770 
3771 	stats->fragments++;
3772 
3773 	if (!(status->flag & RX_FLAG_NO_SIGNAL_VAL)) {
3774 		stats->last_signal = status->signal;
3775 		if (!fast_rx->uses_rss)
3776 			ewma_signal_add(&sta->rx_stats_avg.signal,
3777 					-status->signal);
3778 	}
3779 
3780 	if (status->chains) {
3781 		int i;
3782 
3783 		stats->chains = status->chains;
3784 		for (i = 0; i < ARRAY_SIZE(status->chain_signal); i++) {
3785 			int signal = status->chain_signal[i];
3786 
3787 			if (!(status->chains & BIT(i)))
3788 				continue;
3789 
3790 			stats->chain_signal_last[i] = signal;
3791 			if (!fast_rx->uses_rss)
3792 				ewma_signal_add(&sta->rx_stats_avg.chain_signal[i],
3793 						-signal);
3794 		}
3795 	}
3796 	/* end of statistics */
3797 
3798 	if (rx->key && !ieee80211_has_protected(hdr->frame_control))
3799 		goto drop;
3800 
3801 	/* do the header conversion - first grab the addresses */
3802 	ether_addr_copy(addrs.da, skb->data + fast_rx->da_offs);
3803 	ether_addr_copy(addrs.sa, skb->data + fast_rx->sa_offs);
3804 	/* remove the SNAP but leave the ethertype */
3805 	skb_pull(skb, snap_offs + sizeof(rfc1042_header));
3806 	/* push the addresses in front */
3807 	memcpy(skb_push(skb, sizeof(addrs)), &addrs, sizeof(addrs));
3808 
3809 	skb->dev = fast_rx->dev;
3810 
3811 	ieee80211_rx_stats(fast_rx->dev, skb->len);
3812 
3813 	/* The seqno index has the same property as needed
3814 	 * for the rx_msdu field, i.e. it is IEEE80211_NUM_TIDS
3815 	 * for non-QoS-data frames. Here we know it's a data
3816 	 * frame, so count MSDUs.
3817 	 */
3818 	u64_stats_update_begin(&stats->syncp);
3819 	stats->msdu[rx->seqno_idx]++;
3820 	stats->bytes += orig_len;
3821 	u64_stats_update_end(&stats->syncp);
3822 
3823 	if (fast_rx->internal_forward) {
3824 		struct sta_info *dsta = sta_info_get(rx->sdata, skb->data);
3825 
3826 		if (dsta) {
3827 			/*
3828 			 * Send to wireless media and increase priority by 256
3829 			 * to keep the received priority instead of
3830 			 * reclassifying the frame (see cfg80211_classify8021d).
3831 			 */
3832 			skb->priority += 256;
3833 			skb->protocol = htons(ETH_P_802_3);
3834 			skb_reset_network_header(skb);
3835 			skb_reset_mac_header(skb);
3836 			dev_queue_xmit(skb);
3837 			return true;
3838 		}
3839 	}
3840 
3841 	/* deliver to local stack */
3842 	skb->protocol = eth_type_trans(skb, fast_rx->dev);
3843 	memset(skb->cb, 0, sizeof(skb->cb));
3844 	if (rx->napi)
3845 		napi_gro_receive(rx->napi, skb);
3846 	else
3847 		netif_receive_skb(skb);
3848 
3849 	return true;
3850  drop:
3851 	dev_kfree_skb(skb);
3852 	stats->dropped++;
3853 	return true;
3854 }
3855 
3856 /*
3857  * This function returns whether or not the SKB
3858  * was destined for RX processing or not, which,
3859  * if consume is true, is equivalent to whether
3860  * or not the skb was consumed.
3861  */
3862 static bool ieee80211_prepare_and_rx_handle(struct ieee80211_rx_data *rx,
3863 					    struct sk_buff *skb, bool consume)
3864 {
3865 	struct ieee80211_local *local = rx->local;
3866 	struct ieee80211_sub_if_data *sdata = rx->sdata;
3867 
3868 	rx->skb = skb;
3869 
3870 	/* See if we can do fast-rx; if we have to copy we already lost,
3871 	 * so punt in that case. We should never have to deliver a data
3872 	 * frame to multiple interfaces anyway.
3873 	 *
3874 	 * We skip the ieee80211_accept_frame() call and do the necessary
3875 	 * checking inside ieee80211_invoke_fast_rx().
3876 	 */
3877 	if (consume && rx->sta) {
3878 		struct ieee80211_fast_rx *fast_rx;
3879 
3880 		fast_rx = rcu_dereference(rx->sta->fast_rx);
3881 		if (fast_rx && ieee80211_invoke_fast_rx(rx, fast_rx))
3882 			return true;
3883 	}
3884 
3885 	if (!ieee80211_accept_frame(rx))
3886 		return false;
3887 
3888 	if (!consume) {
3889 		skb = skb_copy(skb, GFP_ATOMIC);
3890 		if (!skb) {
3891 			if (net_ratelimit())
3892 				wiphy_debug(local->hw.wiphy,
3893 					"failed to copy skb for %s\n",
3894 					sdata->name);
3895 			return true;
3896 		}
3897 
3898 		rx->skb = skb;
3899 	}
3900 
3901 	ieee80211_invoke_rx_handlers(rx);
3902 	return true;
3903 }
3904 
3905 /*
3906  * This is the actual Rx frames handler. as it belongs to Rx path it must
3907  * be called with rcu_read_lock protection.
3908  */
3909 static void __ieee80211_rx_handle_packet(struct ieee80211_hw *hw,
3910 					 struct ieee80211_sta *pubsta,
3911 					 struct sk_buff *skb,
3912 					 struct napi_struct *napi)
3913 {
3914 	struct ieee80211_local *local = hw_to_local(hw);
3915 	struct ieee80211_sub_if_data *sdata;
3916 	struct ieee80211_hdr *hdr;
3917 	__le16 fc;
3918 	struct ieee80211_rx_data rx;
3919 	struct ieee80211_sub_if_data *prev;
3920 	struct rhash_head *tmp;
3921 	int err = 0;
3922 
3923 	fc = ((struct ieee80211_hdr *)skb->data)->frame_control;
3924 	memset(&rx, 0, sizeof(rx));
3925 	rx.skb = skb;
3926 	rx.local = local;
3927 	rx.napi = napi;
3928 
3929 	if (ieee80211_is_data(fc) || ieee80211_is_mgmt(fc))
3930 		I802_DEBUG_INC(local->dot11ReceivedFragmentCount);
3931 
3932 	if (ieee80211_is_mgmt(fc)) {
3933 		/* drop frame if too short for header */
3934 		if (skb->len < ieee80211_hdrlen(fc))
3935 			err = -ENOBUFS;
3936 		else
3937 			err = skb_linearize(skb);
3938 	} else {
3939 		err = !pskb_may_pull(skb, ieee80211_hdrlen(fc));
3940 	}
3941 
3942 	if (err) {
3943 		dev_kfree_skb(skb);
3944 		return;
3945 	}
3946 
3947 	hdr = (struct ieee80211_hdr *)skb->data;
3948 	ieee80211_parse_qos(&rx);
3949 	ieee80211_verify_alignment(&rx);
3950 
3951 	if (unlikely(ieee80211_is_probe_resp(hdr->frame_control) ||
3952 		     ieee80211_is_beacon(hdr->frame_control)))
3953 		ieee80211_scan_rx(local, skb);
3954 
3955 	if (pubsta) {
3956 		rx.sta = container_of(pubsta, struct sta_info, sta);
3957 		rx.sdata = rx.sta->sdata;
3958 		if (ieee80211_prepare_and_rx_handle(&rx, skb, true))
3959 			return;
3960 		goto out;
3961 	} else if (ieee80211_is_data(fc)) {
3962 		struct sta_info *sta, *prev_sta;
3963 		const struct bucket_table *tbl;
3964 
3965 		prev_sta = NULL;
3966 
3967 		tbl = rht_dereference_rcu(local->sta_hash.tbl, &local->sta_hash);
3968 
3969 		for_each_sta_info(local, tbl, hdr->addr2, sta, tmp) {
3970 			if (!prev_sta) {
3971 				prev_sta = sta;
3972 				continue;
3973 			}
3974 
3975 			rx.sta = prev_sta;
3976 			rx.sdata = prev_sta->sdata;
3977 			ieee80211_prepare_and_rx_handle(&rx, skb, false);
3978 
3979 			prev_sta = sta;
3980 		}
3981 
3982 		if (prev_sta) {
3983 			rx.sta = prev_sta;
3984 			rx.sdata = prev_sta->sdata;
3985 
3986 			if (ieee80211_prepare_and_rx_handle(&rx, skb, true))
3987 				return;
3988 			goto out;
3989 		}
3990 	}
3991 
3992 	prev = NULL;
3993 
3994 	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
3995 		if (!ieee80211_sdata_running(sdata))
3996 			continue;
3997 
3998 		if (sdata->vif.type == NL80211_IFTYPE_MONITOR ||
3999 		    sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
4000 			continue;
4001 
4002 		/*
4003 		 * frame is destined for this interface, but if it's
4004 		 * not also for the previous one we handle that after
4005 		 * the loop to avoid copying the SKB once too much
4006 		 */
4007 
4008 		if (!prev) {
4009 			prev = sdata;
4010 			continue;
4011 		}
4012 
4013 		rx.sta = sta_info_get_bss(prev, hdr->addr2);
4014 		rx.sdata = prev;
4015 		ieee80211_prepare_and_rx_handle(&rx, skb, false);
4016 
4017 		prev = sdata;
4018 	}
4019 
4020 	if (prev) {
4021 		rx.sta = sta_info_get_bss(prev, hdr->addr2);
4022 		rx.sdata = prev;
4023 
4024 		if (ieee80211_prepare_and_rx_handle(&rx, skb, true))
4025 			return;
4026 	}
4027 
4028  out:
4029 	dev_kfree_skb(skb);
4030 }
4031 
4032 /*
4033  * This is the receive path handler. It is called by a low level driver when an
4034  * 802.11 MPDU is received from the hardware.
4035  */
4036 void ieee80211_rx_napi(struct ieee80211_hw *hw, struct ieee80211_sta *pubsta,
4037 		       struct sk_buff *skb, struct napi_struct *napi)
4038 {
4039 	struct ieee80211_local *local = hw_to_local(hw);
4040 	struct ieee80211_rate *rate = NULL;
4041 	struct ieee80211_supported_band *sband;
4042 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
4043 
4044 	WARN_ON_ONCE(softirq_count() == 0);
4045 
4046 	if (WARN_ON(status->band >= NUM_NL80211_BANDS))
4047 		goto drop;
4048 
4049 	sband = local->hw.wiphy->bands[status->band];
4050 	if (WARN_ON(!sband))
4051 		goto drop;
4052 
4053 	/*
4054 	 * If we're suspending, it is possible although not too likely
4055 	 * that we'd be receiving frames after having already partially
4056 	 * quiesced the stack. We can't process such frames then since
4057 	 * that might, for example, cause stations to be added or other
4058 	 * driver callbacks be invoked.
4059 	 */
4060 	if (unlikely(local->quiescing || local->suspended))
4061 		goto drop;
4062 
4063 	/* We might be during a HW reconfig, prevent Rx for the same reason */
4064 	if (unlikely(local->in_reconfig))
4065 		goto drop;
4066 
4067 	/*
4068 	 * The same happens when we're not even started,
4069 	 * but that's worth a warning.
4070 	 */
4071 	if (WARN_ON(!local->started))
4072 		goto drop;
4073 
4074 	if (likely(!(status->flag & RX_FLAG_FAILED_PLCP_CRC))) {
4075 		/*
4076 		 * Validate the rate, unless a PLCP error means that
4077 		 * we probably can't have a valid rate here anyway.
4078 		 */
4079 
4080 		if (status->flag & RX_FLAG_HT) {
4081 			/*
4082 			 * rate_idx is MCS index, which can be [0-76]
4083 			 * as documented on:
4084 			 *
4085 			 * http://wireless.kernel.org/en/developers/Documentation/ieee80211/802.11n
4086 			 *
4087 			 * Anything else would be some sort of driver or
4088 			 * hardware error. The driver should catch hardware
4089 			 * errors.
4090 			 */
4091 			if (WARN(status->rate_idx > 76,
4092 				 "Rate marked as an HT rate but passed "
4093 				 "status->rate_idx is not "
4094 				 "an MCS index [0-76]: %d (0x%02x)\n",
4095 				 status->rate_idx,
4096 				 status->rate_idx))
4097 				goto drop;
4098 		} else if (status->flag & RX_FLAG_VHT) {
4099 			if (WARN_ONCE(status->rate_idx > 9 ||
4100 				      !status->vht_nss ||
4101 				      status->vht_nss > 8,
4102 				      "Rate marked as a VHT rate but data is invalid: MCS: %d, NSS: %d\n",
4103 				      status->rate_idx, status->vht_nss))
4104 				goto drop;
4105 		} else {
4106 			if (WARN_ON(status->rate_idx >= sband->n_bitrates))
4107 				goto drop;
4108 			rate = &sband->bitrates[status->rate_idx];
4109 		}
4110 	}
4111 
4112 	status->rx_flags = 0;
4113 
4114 	/*
4115 	 * key references and virtual interfaces are protected using RCU
4116 	 * and this requires that we are in a read-side RCU section during
4117 	 * receive processing
4118 	 */
4119 	rcu_read_lock();
4120 
4121 	/*
4122 	 * Frames with failed FCS/PLCP checksum are not returned,
4123 	 * all other frames are returned without radiotap header
4124 	 * if it was previously present.
4125 	 * Also, frames with less than 16 bytes are dropped.
4126 	 */
4127 	skb = ieee80211_rx_monitor(local, skb, rate);
4128 	if (!skb) {
4129 		rcu_read_unlock();
4130 		return;
4131 	}
4132 
4133 	ieee80211_tpt_led_trig_rx(local,
4134 			((struct ieee80211_hdr *)skb->data)->frame_control,
4135 			skb->len);
4136 
4137 	__ieee80211_rx_handle_packet(hw, pubsta, skb, napi);
4138 
4139 	rcu_read_unlock();
4140 
4141 	return;
4142  drop:
4143 	kfree_skb(skb);
4144 }
4145 EXPORT_SYMBOL(ieee80211_rx_napi);
4146 
4147 /* This is a version of the rx handler that can be called from hard irq
4148  * context. Post the skb on the queue and schedule the tasklet */
4149 void ieee80211_rx_irqsafe(struct ieee80211_hw *hw, struct sk_buff *skb)
4150 {
4151 	struct ieee80211_local *local = hw_to_local(hw);
4152 
4153 	BUILD_BUG_ON(sizeof(struct ieee80211_rx_status) > sizeof(skb->cb));
4154 
4155 	skb->pkt_type = IEEE80211_RX_MSG;
4156 	skb_queue_tail(&local->skb_queue, skb);
4157 	tasklet_schedule(&local->tasklet);
4158 }
4159 EXPORT_SYMBOL(ieee80211_rx_irqsafe);
4160