xref: /linux/net/mac80211/rx.c (revision 2d87650a3bf1b80f7d0d150ee1af3f8a89e5b7aa)
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  *
7  * This program is free software; you can redistribute it and/or modify
8  * it under the terms of the GNU General Public License version 2 as
9  * published by the Free Software Foundation.
10  */
11 
12 #include <linux/jiffies.h>
13 #include <linux/slab.h>
14 #include <linux/kernel.h>
15 #include <linux/skbuff.h>
16 #include <linux/netdevice.h>
17 #include <linux/etherdevice.h>
18 #include <linux/rcupdate.h>
19 #include <linux/export.h>
20 #include <net/mac80211.h>
21 #include <net/ieee80211_radiotap.h>
22 #include <asm/unaligned.h>
23 
24 #include "ieee80211_i.h"
25 #include "driver-ops.h"
26 #include "led.h"
27 #include "mesh.h"
28 #include "wep.h"
29 #include "wpa.h"
30 #include "tkip.h"
31 #include "wme.h"
32 #include "rate.h"
33 
34 /*
35  * monitor mode reception
36  *
37  * This function cleans up the SKB, i.e. it removes all the stuff
38  * only useful for monitoring.
39  */
40 static struct sk_buff *remove_monitor_info(struct ieee80211_local *local,
41 					   struct sk_buff *skb)
42 {
43 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
44 
45 	if (local->hw.flags & IEEE80211_HW_RX_INCLUDES_FCS) {
46 		if (likely(skb->len > FCS_LEN))
47 			__pskb_trim(skb, skb->len - FCS_LEN);
48 		else {
49 			/* driver bug */
50 			WARN_ON(1);
51 			dev_kfree_skb(skb);
52 			return NULL;
53 		}
54 	}
55 
56 	if (status->vendor_radiotap_len)
57 		__pskb_pull(skb, status->vendor_radiotap_len);
58 
59 	return skb;
60 }
61 
62 static inline int should_drop_frame(struct sk_buff *skb, int present_fcs_len)
63 {
64 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
65 	struct ieee80211_hdr *hdr;
66 
67 	hdr = (void *)(skb->data + status->vendor_radiotap_len);
68 
69 	if (status->flag & (RX_FLAG_FAILED_FCS_CRC |
70 			    RX_FLAG_FAILED_PLCP_CRC |
71 			    RX_FLAG_AMPDU_IS_ZEROLEN))
72 		return 1;
73 	if (unlikely(skb->len < 16 + present_fcs_len +
74 				status->vendor_radiotap_len))
75 		return 1;
76 	if (ieee80211_is_ctl(hdr->frame_control) &&
77 	    !ieee80211_is_pspoll(hdr->frame_control) &&
78 	    !ieee80211_is_back_req(hdr->frame_control))
79 		return 1;
80 	return 0;
81 }
82 
83 static int
84 ieee80211_rx_radiotap_space(struct ieee80211_local *local,
85 			    struct ieee80211_rx_status *status)
86 {
87 	int len;
88 
89 	/* always present fields */
90 	len = sizeof(struct ieee80211_radiotap_header) + 8;
91 
92 	/* allocate extra bitmaps */
93 	if (status->vendor_radiotap_len)
94 		len += 4;
95 	if (status->chains)
96 		len += 4 * hweight8(status->chains);
97 
98 	if (ieee80211_have_rx_timestamp(status)) {
99 		len = ALIGN(len, 8);
100 		len += 8;
101 	}
102 	if (local->hw.flags & IEEE80211_HW_SIGNAL_DBM)
103 		len += 1;
104 
105 	/* antenna field, if we don't have per-chain info */
106 	if (!status->chains)
107 		len += 1;
108 
109 	/* padding for RX_FLAGS if necessary */
110 	len = ALIGN(len, 2);
111 
112 	if (status->flag & RX_FLAG_HT) /* HT info */
113 		len += 3;
114 
115 	if (status->flag & RX_FLAG_AMPDU_DETAILS) {
116 		len = ALIGN(len, 4);
117 		len += 8;
118 	}
119 
120 	if (status->flag & RX_FLAG_VHT) {
121 		len = ALIGN(len, 2);
122 		len += 12;
123 	}
124 
125 	if (status->chains) {
126 		/* antenna and antenna signal fields */
127 		len += 2 * hweight8(status->chains);
128 	}
129 
130 	if (status->vendor_radiotap_len) {
131 		if (WARN_ON_ONCE(status->vendor_radiotap_align == 0))
132 			status->vendor_radiotap_align = 1;
133 		/* align standard part of vendor namespace */
134 		len = ALIGN(len, 2);
135 		/* allocate standard part of vendor namespace */
136 		len += 6;
137 		/* align vendor-defined part */
138 		len = ALIGN(len, status->vendor_radiotap_align);
139 		/* vendor-defined part is already in skb */
140 	}
141 
142 	return len;
143 }
144 
145 /*
146  * ieee80211_add_rx_radiotap_header - add radiotap header
147  *
148  * add a radiotap header containing all the fields which the hardware provided.
149  */
150 static void
151 ieee80211_add_rx_radiotap_header(struct ieee80211_local *local,
152 				 struct sk_buff *skb,
153 				 struct ieee80211_rate *rate,
154 				 int rtap_len, bool has_fcs)
155 {
156 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
157 	struct ieee80211_radiotap_header *rthdr;
158 	unsigned char *pos;
159 	__le32 *it_present;
160 	u32 it_present_val;
161 	u16 rx_flags = 0;
162 	u16 channel_flags = 0;
163 	int mpdulen, chain;
164 	unsigned long chains = status->chains;
165 
166 	mpdulen = skb->len;
167 	if (!(has_fcs && (local->hw.flags & IEEE80211_HW_RX_INCLUDES_FCS)))
168 		mpdulen += FCS_LEN;
169 
170 	rthdr = (struct ieee80211_radiotap_header *)skb_push(skb, rtap_len);
171 	memset(rthdr, 0, rtap_len);
172 	it_present = &rthdr->it_present;
173 
174 	/* radiotap header, set always present flags */
175 	rthdr->it_len = cpu_to_le16(rtap_len + status->vendor_radiotap_len);
176 	it_present_val = BIT(IEEE80211_RADIOTAP_FLAGS) |
177 			 BIT(IEEE80211_RADIOTAP_CHANNEL) |
178 			 BIT(IEEE80211_RADIOTAP_RX_FLAGS);
179 
180 	if (!status->chains)
181 		it_present_val |= BIT(IEEE80211_RADIOTAP_ANTENNA);
182 
183 	for_each_set_bit(chain, &chains, IEEE80211_MAX_CHAINS) {
184 		it_present_val |=
185 			BIT(IEEE80211_RADIOTAP_EXT) |
186 			BIT(IEEE80211_RADIOTAP_RADIOTAP_NAMESPACE);
187 		put_unaligned_le32(it_present_val, it_present);
188 		it_present++;
189 		it_present_val = BIT(IEEE80211_RADIOTAP_ANTENNA) |
190 				 BIT(IEEE80211_RADIOTAP_DBM_ANTSIGNAL);
191 	}
192 
193 	if (status->vendor_radiotap_len) {
194 		it_present_val |= BIT(IEEE80211_RADIOTAP_VENDOR_NAMESPACE) |
195 				  BIT(IEEE80211_RADIOTAP_EXT);
196 		put_unaligned_le32(it_present_val, it_present);
197 		it_present++;
198 		it_present_val = status->vendor_radiotap_bitmap;
199 	}
200 
201 	put_unaligned_le32(it_present_val, it_present);
202 
203 	pos = (void *)(it_present + 1);
204 
205 	/* the order of the following fields is important */
206 
207 	/* IEEE80211_RADIOTAP_TSFT */
208 	if (ieee80211_have_rx_timestamp(status)) {
209 		/* padding */
210 		while ((pos - (u8 *)rthdr) & 7)
211 			*pos++ = 0;
212 		put_unaligned_le64(
213 			ieee80211_calculate_rx_timestamp(local, status,
214 							 mpdulen, 0),
215 			pos);
216 		rthdr->it_present |= cpu_to_le32(1 << IEEE80211_RADIOTAP_TSFT);
217 		pos += 8;
218 	}
219 
220 	/* IEEE80211_RADIOTAP_FLAGS */
221 	if (has_fcs && (local->hw.flags & IEEE80211_HW_RX_INCLUDES_FCS))
222 		*pos |= IEEE80211_RADIOTAP_F_FCS;
223 	if (status->flag & (RX_FLAG_FAILED_FCS_CRC | RX_FLAG_FAILED_PLCP_CRC))
224 		*pos |= IEEE80211_RADIOTAP_F_BADFCS;
225 	if (status->flag & RX_FLAG_SHORTPRE)
226 		*pos |= IEEE80211_RADIOTAP_F_SHORTPRE;
227 	pos++;
228 
229 	/* IEEE80211_RADIOTAP_RATE */
230 	if (!rate || status->flag & (RX_FLAG_HT | RX_FLAG_VHT)) {
231 		/*
232 		 * Without rate information don't add it. If we have,
233 		 * MCS information is a separate field in radiotap,
234 		 * added below. The byte here is needed as padding
235 		 * for the channel though, so initialise it to 0.
236 		 */
237 		*pos = 0;
238 	} else {
239 		int shift = 0;
240 		rthdr->it_present |= cpu_to_le32(1 << IEEE80211_RADIOTAP_RATE);
241 		if (status->flag & RX_FLAG_10MHZ)
242 			shift = 1;
243 		else if (status->flag & RX_FLAG_5MHZ)
244 			shift = 2;
245 		*pos = DIV_ROUND_UP(rate->bitrate, 5 * (1 << shift));
246 	}
247 	pos++;
248 
249 	/* IEEE80211_RADIOTAP_CHANNEL */
250 	put_unaligned_le16(status->freq, pos);
251 	pos += 2;
252 	if (status->flag & RX_FLAG_10MHZ)
253 		channel_flags |= IEEE80211_CHAN_HALF;
254 	else if (status->flag & RX_FLAG_5MHZ)
255 		channel_flags |= IEEE80211_CHAN_QUARTER;
256 
257 	if (status->band == IEEE80211_BAND_5GHZ)
258 		channel_flags |= IEEE80211_CHAN_OFDM | IEEE80211_CHAN_5GHZ;
259 	else if (status->flag & (RX_FLAG_HT | RX_FLAG_VHT))
260 		channel_flags |= IEEE80211_CHAN_DYN | IEEE80211_CHAN_2GHZ;
261 	else if (rate && rate->flags & IEEE80211_RATE_ERP_G)
262 		channel_flags |= IEEE80211_CHAN_OFDM | IEEE80211_CHAN_2GHZ;
263 	else if (rate)
264 		channel_flags |= IEEE80211_CHAN_OFDM | IEEE80211_CHAN_2GHZ;
265 	else
266 		channel_flags |= IEEE80211_CHAN_2GHZ;
267 	put_unaligned_le16(channel_flags, pos);
268 	pos += 2;
269 
270 	/* IEEE80211_RADIOTAP_DBM_ANTSIGNAL */
271 	if (local->hw.flags & IEEE80211_HW_SIGNAL_DBM &&
272 	    !(status->flag & RX_FLAG_NO_SIGNAL_VAL)) {
273 		*pos = status->signal;
274 		rthdr->it_present |=
275 			cpu_to_le32(1 << IEEE80211_RADIOTAP_DBM_ANTSIGNAL);
276 		pos++;
277 	}
278 
279 	/* IEEE80211_RADIOTAP_LOCK_QUALITY is missing */
280 
281 	if (!status->chains) {
282 		/* IEEE80211_RADIOTAP_ANTENNA */
283 		*pos = status->antenna;
284 		pos++;
285 	}
286 
287 	/* IEEE80211_RADIOTAP_DB_ANTNOISE is not used */
288 
289 	/* IEEE80211_RADIOTAP_RX_FLAGS */
290 	/* ensure 2 byte alignment for the 2 byte field as required */
291 	if ((pos - (u8 *)rthdr) & 1)
292 		*pos++ = 0;
293 	if (status->flag & RX_FLAG_FAILED_PLCP_CRC)
294 		rx_flags |= IEEE80211_RADIOTAP_F_RX_BADPLCP;
295 	put_unaligned_le16(rx_flags, pos);
296 	pos += 2;
297 
298 	if (status->flag & RX_FLAG_HT) {
299 		unsigned int stbc;
300 
301 		rthdr->it_present |= cpu_to_le32(1 << IEEE80211_RADIOTAP_MCS);
302 		*pos++ = local->hw.radiotap_mcs_details;
303 		*pos = 0;
304 		if (status->flag & RX_FLAG_SHORT_GI)
305 			*pos |= IEEE80211_RADIOTAP_MCS_SGI;
306 		if (status->flag & RX_FLAG_40MHZ)
307 			*pos |= IEEE80211_RADIOTAP_MCS_BW_40;
308 		if (status->flag & RX_FLAG_HT_GF)
309 			*pos |= IEEE80211_RADIOTAP_MCS_FMT_GF;
310 		stbc = (status->flag & RX_FLAG_STBC_MASK) >> RX_FLAG_STBC_SHIFT;
311 		*pos |= stbc << IEEE80211_RADIOTAP_MCS_STBC_SHIFT;
312 		pos++;
313 		*pos++ = status->rate_idx;
314 	}
315 
316 	if (status->flag & RX_FLAG_AMPDU_DETAILS) {
317 		u16 flags = 0;
318 
319 		/* ensure 4 byte alignment */
320 		while ((pos - (u8 *)rthdr) & 3)
321 			pos++;
322 		rthdr->it_present |=
323 			cpu_to_le32(1 << IEEE80211_RADIOTAP_AMPDU_STATUS);
324 		put_unaligned_le32(status->ampdu_reference, pos);
325 		pos += 4;
326 		if (status->flag & RX_FLAG_AMPDU_REPORT_ZEROLEN)
327 			flags |= IEEE80211_RADIOTAP_AMPDU_REPORT_ZEROLEN;
328 		if (status->flag & RX_FLAG_AMPDU_IS_ZEROLEN)
329 			flags |= IEEE80211_RADIOTAP_AMPDU_IS_ZEROLEN;
330 		if (status->flag & RX_FLAG_AMPDU_LAST_KNOWN)
331 			flags |= IEEE80211_RADIOTAP_AMPDU_LAST_KNOWN;
332 		if (status->flag & RX_FLAG_AMPDU_IS_LAST)
333 			flags |= IEEE80211_RADIOTAP_AMPDU_IS_LAST;
334 		if (status->flag & RX_FLAG_AMPDU_DELIM_CRC_ERROR)
335 			flags |= IEEE80211_RADIOTAP_AMPDU_DELIM_CRC_ERR;
336 		if (status->flag & RX_FLAG_AMPDU_DELIM_CRC_KNOWN)
337 			flags |= IEEE80211_RADIOTAP_AMPDU_DELIM_CRC_KNOWN;
338 		put_unaligned_le16(flags, pos);
339 		pos += 2;
340 		if (status->flag & RX_FLAG_AMPDU_DELIM_CRC_KNOWN)
341 			*pos++ = status->ampdu_delimiter_crc;
342 		else
343 			*pos++ = 0;
344 		*pos++ = 0;
345 	}
346 
347 	if (status->flag & RX_FLAG_VHT) {
348 		u16 known = local->hw.radiotap_vht_details;
349 
350 		rthdr->it_present |= cpu_to_le32(1 << IEEE80211_RADIOTAP_VHT);
351 		/* known field - how to handle 80+80? */
352 		if (status->flag & RX_FLAG_80P80MHZ)
353 			known &= ~IEEE80211_RADIOTAP_VHT_KNOWN_BANDWIDTH;
354 		put_unaligned_le16(known, pos);
355 		pos += 2;
356 		/* flags */
357 		if (status->flag & RX_FLAG_SHORT_GI)
358 			*pos |= IEEE80211_RADIOTAP_VHT_FLAG_SGI;
359 		pos++;
360 		/* bandwidth */
361 		if (status->flag & RX_FLAG_80MHZ)
362 			*pos++ = 4;
363 		else if (status->flag & RX_FLAG_80P80MHZ)
364 			*pos++ = 0; /* marked not known above */
365 		else if (status->flag & RX_FLAG_160MHZ)
366 			*pos++ = 11;
367 		else if (status->flag & RX_FLAG_40MHZ)
368 			*pos++ = 1;
369 		else /* 20 MHz */
370 			*pos++ = 0;
371 		/* MCS/NSS */
372 		*pos = (status->rate_idx << 4) | status->vht_nss;
373 		pos += 4;
374 		/* coding field */
375 		pos++;
376 		/* group ID */
377 		pos++;
378 		/* partial_aid */
379 		pos += 2;
380 	}
381 
382 	for_each_set_bit(chain, &chains, IEEE80211_MAX_CHAINS) {
383 		*pos++ = status->chain_signal[chain];
384 		*pos++ = chain;
385 	}
386 
387 	if (status->vendor_radiotap_len) {
388 		/* ensure 2 byte alignment for the vendor field as required */
389 		if ((pos - (u8 *)rthdr) & 1)
390 			*pos++ = 0;
391 		*pos++ = status->vendor_radiotap_oui[0];
392 		*pos++ = status->vendor_radiotap_oui[1];
393 		*pos++ = status->vendor_radiotap_oui[2];
394 		*pos++ = status->vendor_radiotap_subns;
395 		put_unaligned_le16(status->vendor_radiotap_len, pos);
396 		pos += 2;
397 		/* align the actual payload as requested */
398 		while ((pos - (u8 *)rthdr) & (status->vendor_radiotap_align - 1))
399 			*pos++ = 0;
400 	}
401 }
402 
403 /*
404  * This function copies a received frame to all monitor interfaces and
405  * returns a cleaned-up SKB that no longer includes the FCS nor the
406  * radiotap header the driver might have added.
407  */
408 static struct sk_buff *
409 ieee80211_rx_monitor(struct ieee80211_local *local, struct sk_buff *origskb,
410 		     struct ieee80211_rate *rate)
411 {
412 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(origskb);
413 	struct ieee80211_sub_if_data *sdata;
414 	int needed_headroom;
415 	struct sk_buff *skb, *skb2;
416 	struct net_device *prev_dev = NULL;
417 	int present_fcs_len = 0;
418 
419 	/*
420 	 * First, we may need to make a copy of the skb because
421 	 *  (1) we need to modify it for radiotap (if not present), and
422 	 *  (2) the other RX handlers will modify the skb we got.
423 	 *
424 	 * We don't need to, of course, if we aren't going to return
425 	 * the SKB because it has a bad FCS/PLCP checksum.
426 	 */
427 
428 	if (local->hw.flags & IEEE80211_HW_RX_INCLUDES_FCS)
429 		present_fcs_len = FCS_LEN;
430 
431 	/* ensure hdr->frame_control and vendor radiotap data are in skb head */
432 	if (!pskb_may_pull(origskb, 2 + status->vendor_radiotap_len)) {
433 		dev_kfree_skb(origskb);
434 		return NULL;
435 	}
436 
437 	if (!local->monitors) {
438 		if (should_drop_frame(origskb, present_fcs_len)) {
439 			dev_kfree_skb(origskb);
440 			return NULL;
441 		}
442 
443 		return remove_monitor_info(local, origskb);
444 	}
445 
446 	/* room for the radiotap header based on driver features */
447 	needed_headroom = ieee80211_rx_radiotap_space(local, status);
448 
449 	if (should_drop_frame(origskb, present_fcs_len)) {
450 		/* only need to expand headroom if necessary */
451 		skb = origskb;
452 		origskb = NULL;
453 
454 		/*
455 		 * This shouldn't trigger often because most devices have an
456 		 * RX header they pull before we get here, and that should
457 		 * be big enough for our radiotap information. We should
458 		 * probably export the length to drivers so that we can have
459 		 * them allocate enough headroom to start with.
460 		 */
461 		if (skb_headroom(skb) < needed_headroom &&
462 		    pskb_expand_head(skb, needed_headroom, 0, GFP_ATOMIC)) {
463 			dev_kfree_skb(skb);
464 			return NULL;
465 		}
466 	} else {
467 		/*
468 		 * Need to make a copy and possibly remove radiotap header
469 		 * and FCS from the original.
470 		 */
471 		skb = skb_copy_expand(origskb, needed_headroom, 0, GFP_ATOMIC);
472 
473 		origskb = remove_monitor_info(local, origskb);
474 
475 		if (!skb)
476 			return origskb;
477 	}
478 
479 	/* prepend radiotap information */
480 	ieee80211_add_rx_radiotap_header(local, skb, rate, needed_headroom,
481 					 true);
482 
483 	skb_reset_mac_header(skb);
484 	skb->ip_summed = CHECKSUM_UNNECESSARY;
485 	skb->pkt_type = PACKET_OTHERHOST;
486 	skb->protocol = htons(ETH_P_802_2);
487 
488 	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
489 		if (sdata->vif.type != NL80211_IFTYPE_MONITOR)
490 			continue;
491 
492 		if (sdata->u.mntr_flags & MONITOR_FLAG_COOK_FRAMES)
493 			continue;
494 
495 		if (!ieee80211_sdata_running(sdata))
496 			continue;
497 
498 		if (prev_dev) {
499 			skb2 = skb_clone(skb, GFP_ATOMIC);
500 			if (skb2) {
501 				skb2->dev = prev_dev;
502 				netif_receive_skb(skb2);
503 			}
504 		}
505 
506 		prev_dev = sdata->dev;
507 		sdata->dev->stats.rx_packets++;
508 		sdata->dev->stats.rx_bytes += skb->len;
509 	}
510 
511 	if (prev_dev) {
512 		skb->dev = prev_dev;
513 		netif_receive_skb(skb);
514 	} else
515 		dev_kfree_skb(skb);
516 
517 	return origskb;
518 }
519 
520 static void ieee80211_parse_qos(struct ieee80211_rx_data *rx)
521 {
522 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
523 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
524 	int tid, seqno_idx, security_idx;
525 
526 	/* does the frame have a qos control field? */
527 	if (ieee80211_is_data_qos(hdr->frame_control)) {
528 		u8 *qc = ieee80211_get_qos_ctl(hdr);
529 		/* frame has qos control */
530 		tid = *qc & IEEE80211_QOS_CTL_TID_MASK;
531 		if (*qc & IEEE80211_QOS_CTL_A_MSDU_PRESENT)
532 			status->rx_flags |= IEEE80211_RX_AMSDU;
533 
534 		seqno_idx = tid;
535 		security_idx = tid;
536 	} else {
537 		/*
538 		 * IEEE 802.11-2007, 7.1.3.4.1 ("Sequence Number field"):
539 		 *
540 		 *	Sequence numbers for management frames, QoS data
541 		 *	frames with a broadcast/multicast address in the
542 		 *	Address 1 field, and all non-QoS data frames sent
543 		 *	by QoS STAs are assigned using an additional single
544 		 *	modulo-4096 counter, [...]
545 		 *
546 		 * We also use that counter for non-QoS STAs.
547 		 */
548 		seqno_idx = IEEE80211_NUM_TIDS;
549 		security_idx = 0;
550 		if (ieee80211_is_mgmt(hdr->frame_control))
551 			security_idx = IEEE80211_NUM_TIDS;
552 		tid = 0;
553 	}
554 
555 	rx->seqno_idx = seqno_idx;
556 	rx->security_idx = security_idx;
557 	/* Set skb->priority to 1d tag if highest order bit of TID is not set.
558 	 * For now, set skb->priority to 0 for other cases. */
559 	rx->skb->priority = (tid > 7) ? 0 : tid;
560 }
561 
562 /**
563  * DOC: Packet alignment
564  *
565  * Drivers always need to pass packets that are aligned to two-byte boundaries
566  * to the stack.
567  *
568  * Additionally, should, if possible, align the payload data in a way that
569  * guarantees that the contained IP header is aligned to a four-byte
570  * boundary. In the case of regular frames, this simply means aligning the
571  * payload to a four-byte boundary (because either the IP header is directly
572  * contained, or IV/RFC1042 headers that have a length divisible by four are
573  * in front of it).  If the payload data is not properly aligned and the
574  * architecture doesn't support efficient unaligned operations, mac80211
575  * will align the data.
576  *
577  * With A-MSDU frames, however, the payload data address must yield two modulo
578  * four because there are 14-byte 802.3 headers within the A-MSDU frames that
579  * push the IP header further back to a multiple of four again. Thankfully, the
580  * specs were sane enough this time around to require padding each A-MSDU
581  * subframe to a length that is a multiple of four.
582  *
583  * Padding like Atheros hardware adds which is between the 802.11 header and
584  * the payload is not supported, the driver is required to move the 802.11
585  * header to be directly in front of the payload in that case.
586  */
587 static void ieee80211_verify_alignment(struct ieee80211_rx_data *rx)
588 {
589 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG
590 	WARN_ONCE((unsigned long)rx->skb->data & 1,
591 		  "unaligned packet at 0x%p\n", rx->skb->data);
592 #endif
593 }
594 
595 
596 /* rx handlers */
597 
598 static int ieee80211_is_unicast_robust_mgmt_frame(struct sk_buff *skb)
599 {
600 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
601 
602 	if (skb->len < 24 || is_multicast_ether_addr(hdr->addr1))
603 		return 0;
604 
605 	return ieee80211_is_robust_mgmt_frame(hdr);
606 }
607 
608 
609 static int ieee80211_is_multicast_robust_mgmt_frame(struct sk_buff *skb)
610 {
611 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
612 
613 	if (skb->len < 24 || !is_multicast_ether_addr(hdr->addr1))
614 		return 0;
615 
616 	return ieee80211_is_robust_mgmt_frame(hdr);
617 }
618 
619 
620 /* Get the BIP key index from MMIE; return -1 if this is not a BIP frame */
621 static int ieee80211_get_mmie_keyidx(struct sk_buff *skb)
622 {
623 	struct ieee80211_mgmt *hdr = (struct ieee80211_mgmt *) skb->data;
624 	struct ieee80211_mmie *mmie;
625 
626 	if (skb->len < 24 + sizeof(*mmie) || !is_multicast_ether_addr(hdr->da))
627 		return -1;
628 
629 	if (!ieee80211_is_robust_mgmt_frame((struct ieee80211_hdr *) hdr))
630 		return -1; /* not a robust management frame */
631 
632 	mmie = (struct ieee80211_mmie *)
633 		(skb->data + skb->len - sizeof(*mmie));
634 	if (mmie->element_id != WLAN_EID_MMIE ||
635 	    mmie->length != sizeof(*mmie) - 2)
636 		return -1;
637 
638 	return le16_to_cpu(mmie->key_id);
639 }
640 
641 static int iwl80211_get_cs_keyid(const struct ieee80211_cipher_scheme *cs,
642 				 struct sk_buff *skb)
643 {
644 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
645 	__le16 fc;
646 	int hdrlen;
647 	u8 keyid;
648 
649 	fc = hdr->frame_control;
650 	hdrlen = ieee80211_hdrlen(fc);
651 
652 	if (skb->len < hdrlen + cs->hdr_len)
653 		return -EINVAL;
654 
655 	skb_copy_bits(skb, hdrlen + cs->key_idx_off, &keyid, 1);
656 	keyid &= cs->key_idx_mask;
657 	keyid >>= cs->key_idx_shift;
658 
659 	return keyid;
660 }
661 
662 static ieee80211_rx_result ieee80211_rx_mesh_check(struct ieee80211_rx_data *rx)
663 {
664 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
665 	char *dev_addr = rx->sdata->vif.addr;
666 
667 	if (ieee80211_is_data(hdr->frame_control)) {
668 		if (is_multicast_ether_addr(hdr->addr1)) {
669 			if (ieee80211_has_tods(hdr->frame_control) ||
670 			    !ieee80211_has_fromds(hdr->frame_control))
671 				return RX_DROP_MONITOR;
672 			if (ether_addr_equal(hdr->addr3, dev_addr))
673 				return RX_DROP_MONITOR;
674 		} else {
675 			if (!ieee80211_has_a4(hdr->frame_control))
676 				return RX_DROP_MONITOR;
677 			if (ether_addr_equal(hdr->addr4, dev_addr))
678 				return RX_DROP_MONITOR;
679 		}
680 	}
681 
682 	/* If there is not an established peer link and this is not a peer link
683 	 * establisment frame, beacon or probe, drop the frame.
684 	 */
685 
686 	if (!rx->sta || sta_plink_state(rx->sta) != NL80211_PLINK_ESTAB) {
687 		struct ieee80211_mgmt *mgmt;
688 
689 		if (!ieee80211_is_mgmt(hdr->frame_control))
690 			return RX_DROP_MONITOR;
691 
692 		if (ieee80211_is_action(hdr->frame_control)) {
693 			u8 category;
694 
695 			/* make sure category field is present */
696 			if (rx->skb->len < IEEE80211_MIN_ACTION_SIZE)
697 				return RX_DROP_MONITOR;
698 
699 			mgmt = (struct ieee80211_mgmt *)hdr;
700 			category = mgmt->u.action.category;
701 			if (category != WLAN_CATEGORY_MESH_ACTION &&
702 			    category != WLAN_CATEGORY_SELF_PROTECTED)
703 				return RX_DROP_MONITOR;
704 			return RX_CONTINUE;
705 		}
706 
707 		if (ieee80211_is_probe_req(hdr->frame_control) ||
708 		    ieee80211_is_probe_resp(hdr->frame_control) ||
709 		    ieee80211_is_beacon(hdr->frame_control) ||
710 		    ieee80211_is_auth(hdr->frame_control))
711 			return RX_CONTINUE;
712 
713 		return RX_DROP_MONITOR;
714 	}
715 
716 	return RX_CONTINUE;
717 }
718 
719 static void ieee80211_release_reorder_frame(struct ieee80211_sub_if_data *sdata,
720 					    struct tid_ampdu_rx *tid_agg_rx,
721 					    int index,
722 					    struct sk_buff_head *frames)
723 {
724 	struct sk_buff *skb = tid_agg_rx->reorder_buf[index];
725 	struct ieee80211_rx_status *status;
726 
727 	lockdep_assert_held(&tid_agg_rx->reorder_lock);
728 
729 	if (!skb)
730 		goto no_frame;
731 
732 	/* release the frame from the reorder ring buffer */
733 	tid_agg_rx->stored_mpdu_num--;
734 	tid_agg_rx->reorder_buf[index] = NULL;
735 	status = IEEE80211_SKB_RXCB(skb);
736 	status->rx_flags |= IEEE80211_RX_DEFERRED_RELEASE;
737 	__skb_queue_tail(frames, skb);
738 
739 no_frame:
740 	tid_agg_rx->head_seq_num = ieee80211_sn_inc(tid_agg_rx->head_seq_num);
741 }
742 
743 static void ieee80211_release_reorder_frames(struct ieee80211_sub_if_data *sdata,
744 					     struct tid_ampdu_rx *tid_agg_rx,
745 					     u16 head_seq_num,
746 					     struct sk_buff_head *frames)
747 {
748 	int index;
749 
750 	lockdep_assert_held(&tid_agg_rx->reorder_lock);
751 
752 	while (ieee80211_sn_less(tid_agg_rx->head_seq_num, head_seq_num)) {
753 		index = tid_agg_rx->head_seq_num % tid_agg_rx->buf_size;
754 		ieee80211_release_reorder_frame(sdata, tid_agg_rx, index,
755 						frames);
756 	}
757 }
758 
759 /*
760  * Timeout (in jiffies) for skb's that are waiting in the RX reorder buffer. If
761  * the skb was added to the buffer longer than this time ago, the earlier
762  * frames that have not yet been received are assumed to be lost and the skb
763  * can be released for processing. This may also release other skb's from the
764  * reorder buffer if there are no additional gaps between the frames.
765  *
766  * Callers must hold tid_agg_rx->reorder_lock.
767  */
768 #define HT_RX_REORDER_BUF_TIMEOUT (HZ / 10)
769 
770 static void ieee80211_sta_reorder_release(struct ieee80211_sub_if_data *sdata,
771 					  struct tid_ampdu_rx *tid_agg_rx,
772 					  struct sk_buff_head *frames)
773 {
774 	int index, j;
775 
776 	lockdep_assert_held(&tid_agg_rx->reorder_lock);
777 
778 	/* release the buffer until next missing frame */
779 	index = tid_agg_rx->head_seq_num % tid_agg_rx->buf_size;
780 	if (!tid_agg_rx->reorder_buf[index] &&
781 	    tid_agg_rx->stored_mpdu_num) {
782 		/*
783 		 * No buffers ready to be released, but check whether any
784 		 * frames in the reorder buffer have timed out.
785 		 */
786 		int skipped = 1;
787 		for (j = (index + 1) % tid_agg_rx->buf_size; j != index;
788 		     j = (j + 1) % tid_agg_rx->buf_size) {
789 			if (!tid_agg_rx->reorder_buf[j]) {
790 				skipped++;
791 				continue;
792 			}
793 			if (skipped &&
794 			    !time_after(jiffies, tid_agg_rx->reorder_time[j] +
795 					HT_RX_REORDER_BUF_TIMEOUT))
796 				goto set_release_timer;
797 
798 			ht_dbg_ratelimited(sdata,
799 					   "release an RX reorder frame due to timeout on earlier frames\n");
800 			ieee80211_release_reorder_frame(sdata, tid_agg_rx, j,
801 							frames);
802 
803 			/*
804 			 * Increment the head seq# also for the skipped slots.
805 			 */
806 			tid_agg_rx->head_seq_num =
807 				(tid_agg_rx->head_seq_num +
808 				 skipped) & IEEE80211_SN_MASK;
809 			skipped = 0;
810 		}
811 	} else while (tid_agg_rx->reorder_buf[index]) {
812 		ieee80211_release_reorder_frame(sdata, tid_agg_rx, index,
813 						frames);
814 		index =	tid_agg_rx->head_seq_num % tid_agg_rx->buf_size;
815 	}
816 
817 	if (tid_agg_rx->stored_mpdu_num) {
818 		j = index = tid_agg_rx->head_seq_num % tid_agg_rx->buf_size;
819 
820 		for (; j != (index - 1) % tid_agg_rx->buf_size;
821 		     j = (j + 1) % tid_agg_rx->buf_size) {
822 			if (tid_agg_rx->reorder_buf[j])
823 				break;
824 		}
825 
826  set_release_timer:
827 
828 		mod_timer(&tid_agg_rx->reorder_timer,
829 			  tid_agg_rx->reorder_time[j] + 1 +
830 			  HT_RX_REORDER_BUF_TIMEOUT);
831 	} else {
832 		del_timer(&tid_agg_rx->reorder_timer);
833 	}
834 }
835 
836 /*
837  * As this function belongs to the RX path it must be under
838  * rcu_read_lock protection. It returns false if the frame
839  * can be processed immediately, true if it was consumed.
840  */
841 static bool ieee80211_sta_manage_reorder_buf(struct ieee80211_sub_if_data *sdata,
842 					     struct tid_ampdu_rx *tid_agg_rx,
843 					     struct sk_buff *skb,
844 					     struct sk_buff_head *frames)
845 {
846 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
847 	u16 sc = le16_to_cpu(hdr->seq_ctrl);
848 	u16 mpdu_seq_num = (sc & IEEE80211_SCTL_SEQ) >> 4;
849 	u16 head_seq_num, buf_size;
850 	int index;
851 	bool ret = true;
852 
853 	spin_lock(&tid_agg_rx->reorder_lock);
854 
855 	buf_size = tid_agg_rx->buf_size;
856 	head_seq_num = tid_agg_rx->head_seq_num;
857 
858 	/* frame with out of date sequence number */
859 	if (ieee80211_sn_less(mpdu_seq_num, head_seq_num)) {
860 		dev_kfree_skb(skb);
861 		goto out;
862 	}
863 
864 	/*
865 	 * If frame the sequence number exceeds our buffering window
866 	 * size release some previous frames to make room for this one.
867 	 */
868 	if (!ieee80211_sn_less(mpdu_seq_num, head_seq_num + buf_size)) {
869 		head_seq_num = ieee80211_sn_inc(
870 				ieee80211_sn_sub(mpdu_seq_num, buf_size));
871 		/* release stored frames up to new head to stack */
872 		ieee80211_release_reorder_frames(sdata, tid_agg_rx,
873 						 head_seq_num, frames);
874 	}
875 
876 	/* Now the new frame is always in the range of the reordering buffer */
877 
878 	index = mpdu_seq_num % tid_agg_rx->buf_size;
879 
880 	/* check if we already stored this frame */
881 	if (tid_agg_rx->reorder_buf[index]) {
882 		dev_kfree_skb(skb);
883 		goto out;
884 	}
885 
886 	/*
887 	 * If the current MPDU is in the right order and nothing else
888 	 * is stored we can process it directly, no need to buffer it.
889 	 * If it is first but there's something stored, we may be able
890 	 * to release frames after this one.
891 	 */
892 	if (mpdu_seq_num == tid_agg_rx->head_seq_num &&
893 	    tid_agg_rx->stored_mpdu_num == 0) {
894 		tid_agg_rx->head_seq_num =
895 			ieee80211_sn_inc(tid_agg_rx->head_seq_num);
896 		ret = false;
897 		goto out;
898 	}
899 
900 	/* put the frame in the reordering buffer */
901 	tid_agg_rx->reorder_buf[index] = skb;
902 	tid_agg_rx->reorder_time[index] = jiffies;
903 	tid_agg_rx->stored_mpdu_num++;
904 	ieee80211_sta_reorder_release(sdata, tid_agg_rx, frames);
905 
906  out:
907 	spin_unlock(&tid_agg_rx->reorder_lock);
908 	return ret;
909 }
910 
911 /*
912  * Reorder MPDUs from A-MPDUs, keeping them on a buffer. Returns
913  * true if the MPDU was buffered, false if it should be processed.
914  */
915 static void ieee80211_rx_reorder_ampdu(struct ieee80211_rx_data *rx,
916 				       struct sk_buff_head *frames)
917 {
918 	struct sk_buff *skb = rx->skb;
919 	struct ieee80211_local *local = rx->local;
920 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
921 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
922 	struct sta_info *sta = rx->sta;
923 	struct tid_ampdu_rx *tid_agg_rx;
924 	u16 sc;
925 	u8 tid, ack_policy;
926 
927 	if (!ieee80211_is_data_qos(hdr->frame_control) ||
928 	    is_multicast_ether_addr(hdr->addr1))
929 		goto dont_reorder;
930 
931 	/*
932 	 * filter the QoS data rx stream according to
933 	 * STA/TID and check if this STA/TID is on aggregation
934 	 */
935 
936 	if (!sta)
937 		goto dont_reorder;
938 
939 	ack_policy = *ieee80211_get_qos_ctl(hdr) &
940 		     IEEE80211_QOS_CTL_ACK_POLICY_MASK;
941 	tid = *ieee80211_get_qos_ctl(hdr) & IEEE80211_QOS_CTL_TID_MASK;
942 
943 	tid_agg_rx = rcu_dereference(sta->ampdu_mlme.tid_rx[tid]);
944 	if (!tid_agg_rx)
945 		goto dont_reorder;
946 
947 	/* qos null data frames are excluded */
948 	if (unlikely(hdr->frame_control & cpu_to_le16(IEEE80211_STYPE_NULLFUNC)))
949 		goto dont_reorder;
950 
951 	/* not part of a BA session */
952 	if (ack_policy != IEEE80211_QOS_CTL_ACK_POLICY_BLOCKACK &&
953 	    ack_policy != IEEE80211_QOS_CTL_ACK_POLICY_NORMAL)
954 		goto dont_reorder;
955 
956 	/* not actually part of this BA session */
957 	if (!(status->rx_flags & IEEE80211_RX_RA_MATCH))
958 		goto dont_reorder;
959 
960 	/* new, potentially un-ordered, ampdu frame - process it */
961 
962 	/* reset session timer */
963 	if (tid_agg_rx->timeout)
964 		tid_agg_rx->last_rx = jiffies;
965 
966 	/* if this mpdu is fragmented - terminate rx aggregation session */
967 	sc = le16_to_cpu(hdr->seq_ctrl);
968 	if (sc & IEEE80211_SCTL_FRAG) {
969 		skb->pkt_type = IEEE80211_SDATA_QUEUE_TYPE_FRAME;
970 		skb_queue_tail(&rx->sdata->skb_queue, skb);
971 		ieee80211_queue_work(&local->hw, &rx->sdata->work);
972 		return;
973 	}
974 
975 	/*
976 	 * No locking needed -- we will only ever process one
977 	 * RX packet at a time, and thus own tid_agg_rx. All
978 	 * other code manipulating it needs to (and does) make
979 	 * sure that we cannot get to it any more before doing
980 	 * anything with it.
981 	 */
982 	if (ieee80211_sta_manage_reorder_buf(rx->sdata, tid_agg_rx, skb,
983 					     frames))
984 		return;
985 
986  dont_reorder:
987 	__skb_queue_tail(frames, skb);
988 }
989 
990 static ieee80211_rx_result debug_noinline
991 ieee80211_rx_h_check(struct ieee80211_rx_data *rx)
992 {
993 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
994 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
995 
996 	/*
997 	 * Drop duplicate 802.11 retransmissions
998 	 * (IEEE 802.11-2012: 9.3.2.10 "Duplicate detection and recovery")
999 	 */
1000 	if (rx->skb->len >= 24 && rx->sta &&
1001 	    !ieee80211_is_ctl(hdr->frame_control) &&
1002 	    !ieee80211_is_qos_nullfunc(hdr->frame_control) &&
1003 	    !is_multicast_ether_addr(hdr->addr1)) {
1004 		if (unlikely(ieee80211_has_retry(hdr->frame_control) &&
1005 			     rx->sta->last_seq_ctrl[rx->seqno_idx] ==
1006 			     hdr->seq_ctrl)) {
1007 			if (status->rx_flags & IEEE80211_RX_RA_MATCH) {
1008 				rx->local->dot11FrameDuplicateCount++;
1009 				rx->sta->num_duplicates++;
1010 			}
1011 			return RX_DROP_UNUSABLE;
1012 		} else if (!(status->flag & RX_FLAG_AMSDU_MORE)) {
1013 			rx->sta->last_seq_ctrl[rx->seqno_idx] = hdr->seq_ctrl;
1014 		}
1015 	}
1016 
1017 	if (unlikely(rx->skb->len < 16)) {
1018 		I802_DEBUG_INC(rx->local->rx_handlers_drop_short);
1019 		return RX_DROP_MONITOR;
1020 	}
1021 
1022 	/* Drop disallowed frame classes based on STA auth/assoc state;
1023 	 * IEEE 802.11, Chap 5.5.
1024 	 *
1025 	 * mac80211 filters only based on association state, i.e. it drops
1026 	 * Class 3 frames from not associated stations. hostapd sends
1027 	 * deauth/disassoc frames when needed. In addition, hostapd is
1028 	 * responsible for filtering on both auth and assoc states.
1029 	 */
1030 
1031 	if (ieee80211_vif_is_mesh(&rx->sdata->vif))
1032 		return ieee80211_rx_mesh_check(rx);
1033 
1034 	if (unlikely((ieee80211_is_data(hdr->frame_control) ||
1035 		      ieee80211_is_pspoll(hdr->frame_control)) &&
1036 		     rx->sdata->vif.type != NL80211_IFTYPE_ADHOC &&
1037 		     rx->sdata->vif.type != NL80211_IFTYPE_WDS &&
1038 		     (!rx->sta || !test_sta_flag(rx->sta, WLAN_STA_ASSOC)))) {
1039 		/*
1040 		 * accept port control frames from the AP even when it's not
1041 		 * yet marked ASSOC to prevent a race where we don't set the
1042 		 * assoc bit quickly enough before it sends the first frame
1043 		 */
1044 		if (rx->sta && rx->sdata->vif.type == NL80211_IFTYPE_STATION &&
1045 		    ieee80211_is_data_present(hdr->frame_control)) {
1046 			unsigned int hdrlen;
1047 			__be16 ethertype;
1048 
1049 			hdrlen = ieee80211_hdrlen(hdr->frame_control);
1050 
1051 			if (rx->skb->len < hdrlen + 8)
1052 				return RX_DROP_MONITOR;
1053 
1054 			skb_copy_bits(rx->skb, hdrlen + 6, &ethertype, 2);
1055 			if (ethertype == rx->sdata->control_port_protocol)
1056 				return RX_CONTINUE;
1057 		}
1058 
1059 		if (rx->sdata->vif.type == NL80211_IFTYPE_AP &&
1060 		    cfg80211_rx_spurious_frame(rx->sdata->dev,
1061 					       hdr->addr2,
1062 					       GFP_ATOMIC))
1063 			return RX_DROP_UNUSABLE;
1064 
1065 		return RX_DROP_MONITOR;
1066 	}
1067 
1068 	return RX_CONTINUE;
1069 }
1070 
1071 
1072 static ieee80211_rx_result debug_noinline
1073 ieee80211_rx_h_check_more_data(struct ieee80211_rx_data *rx)
1074 {
1075 	struct ieee80211_local *local;
1076 	struct ieee80211_hdr *hdr;
1077 	struct sk_buff *skb;
1078 
1079 	local = rx->local;
1080 	skb = rx->skb;
1081 	hdr = (struct ieee80211_hdr *) skb->data;
1082 
1083 	if (!local->pspolling)
1084 		return RX_CONTINUE;
1085 
1086 	if (!ieee80211_has_fromds(hdr->frame_control))
1087 		/* this is not from AP */
1088 		return RX_CONTINUE;
1089 
1090 	if (!ieee80211_is_data(hdr->frame_control))
1091 		return RX_CONTINUE;
1092 
1093 	if (!ieee80211_has_moredata(hdr->frame_control)) {
1094 		/* AP has no more frames buffered for us */
1095 		local->pspolling = false;
1096 		return RX_CONTINUE;
1097 	}
1098 
1099 	/* more data bit is set, let's request a new frame from the AP */
1100 	ieee80211_send_pspoll(local, rx->sdata);
1101 
1102 	return RX_CONTINUE;
1103 }
1104 
1105 static void sta_ps_start(struct sta_info *sta)
1106 {
1107 	struct ieee80211_sub_if_data *sdata = sta->sdata;
1108 	struct ieee80211_local *local = sdata->local;
1109 	struct ps_data *ps;
1110 
1111 	if (sta->sdata->vif.type == NL80211_IFTYPE_AP ||
1112 	    sta->sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
1113 		ps = &sdata->bss->ps;
1114 	else
1115 		return;
1116 
1117 	atomic_inc(&ps->num_sta_ps);
1118 	set_sta_flag(sta, WLAN_STA_PS_STA);
1119 	if (!(local->hw.flags & IEEE80211_HW_AP_LINK_PS))
1120 		drv_sta_notify(local, sdata, STA_NOTIFY_SLEEP, &sta->sta);
1121 	ps_dbg(sdata, "STA %pM aid %d enters power save mode\n",
1122 	       sta->sta.addr, sta->sta.aid);
1123 }
1124 
1125 static void sta_ps_end(struct sta_info *sta)
1126 {
1127 	ps_dbg(sta->sdata, "STA %pM aid %d exits power save mode\n",
1128 	       sta->sta.addr, sta->sta.aid);
1129 
1130 	if (test_sta_flag(sta, WLAN_STA_PS_DRIVER)) {
1131 		ps_dbg(sta->sdata, "STA %pM aid %d driver-ps-blocked\n",
1132 		       sta->sta.addr, sta->sta.aid);
1133 		return;
1134 	}
1135 
1136 	ieee80211_sta_ps_deliver_wakeup(sta);
1137 }
1138 
1139 int ieee80211_sta_ps_transition(struct ieee80211_sta *sta, bool start)
1140 {
1141 	struct sta_info *sta_inf = container_of(sta, struct sta_info, sta);
1142 	bool in_ps;
1143 
1144 	WARN_ON(!(sta_inf->local->hw.flags & IEEE80211_HW_AP_LINK_PS));
1145 
1146 	/* Don't let the same PS state be set twice */
1147 	in_ps = test_sta_flag(sta_inf, WLAN_STA_PS_STA);
1148 	if ((start && in_ps) || (!start && !in_ps))
1149 		return -EINVAL;
1150 
1151 	if (start)
1152 		sta_ps_start(sta_inf);
1153 	else
1154 		sta_ps_end(sta_inf);
1155 
1156 	return 0;
1157 }
1158 EXPORT_SYMBOL(ieee80211_sta_ps_transition);
1159 
1160 static ieee80211_rx_result debug_noinline
1161 ieee80211_rx_h_uapsd_and_pspoll(struct ieee80211_rx_data *rx)
1162 {
1163 	struct ieee80211_sub_if_data *sdata = rx->sdata;
1164 	struct ieee80211_hdr *hdr = (void *)rx->skb->data;
1165 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
1166 	int tid, ac;
1167 
1168 	if (!rx->sta || !(status->rx_flags & IEEE80211_RX_RA_MATCH))
1169 		return RX_CONTINUE;
1170 
1171 	if (sdata->vif.type != NL80211_IFTYPE_AP &&
1172 	    sdata->vif.type != NL80211_IFTYPE_AP_VLAN)
1173 		return RX_CONTINUE;
1174 
1175 	/*
1176 	 * The device handles station powersave, so don't do anything about
1177 	 * uAPSD and PS-Poll frames (the latter shouldn't even come up from
1178 	 * it to mac80211 since they're handled.)
1179 	 */
1180 	if (sdata->local->hw.flags & IEEE80211_HW_AP_LINK_PS)
1181 		return RX_CONTINUE;
1182 
1183 	/*
1184 	 * Don't do anything if the station isn't already asleep. In
1185 	 * the uAPSD case, the station will probably be marked asleep,
1186 	 * in the PS-Poll case the station must be confused ...
1187 	 */
1188 	if (!test_sta_flag(rx->sta, WLAN_STA_PS_STA))
1189 		return RX_CONTINUE;
1190 
1191 	if (unlikely(ieee80211_is_pspoll(hdr->frame_control))) {
1192 		if (!test_sta_flag(rx->sta, WLAN_STA_SP)) {
1193 			if (!test_sta_flag(rx->sta, WLAN_STA_PS_DRIVER))
1194 				ieee80211_sta_ps_deliver_poll_response(rx->sta);
1195 			else
1196 				set_sta_flag(rx->sta, WLAN_STA_PSPOLL);
1197 		}
1198 
1199 		/* Free PS Poll skb here instead of returning RX_DROP that would
1200 		 * count as an dropped frame. */
1201 		dev_kfree_skb(rx->skb);
1202 
1203 		return RX_QUEUED;
1204 	} else if (!ieee80211_has_morefrags(hdr->frame_control) &&
1205 		   !(status->rx_flags & IEEE80211_RX_DEFERRED_RELEASE) &&
1206 		   ieee80211_has_pm(hdr->frame_control) &&
1207 		   (ieee80211_is_data_qos(hdr->frame_control) ||
1208 		    ieee80211_is_qos_nullfunc(hdr->frame_control))) {
1209 		tid = *ieee80211_get_qos_ctl(hdr) & IEEE80211_QOS_CTL_TID_MASK;
1210 		ac = ieee802_1d_to_ac[tid & 7];
1211 
1212 		/*
1213 		 * If this AC is not trigger-enabled do nothing.
1214 		 *
1215 		 * NB: This could/should check a separate bitmap of trigger-
1216 		 * enabled queues, but for now we only implement uAPSD w/o
1217 		 * TSPEC changes to the ACs, so they're always the same.
1218 		 */
1219 		if (!(rx->sta->sta.uapsd_queues & BIT(ac)))
1220 			return RX_CONTINUE;
1221 
1222 		/* if we are in a service period, do nothing */
1223 		if (test_sta_flag(rx->sta, WLAN_STA_SP))
1224 			return RX_CONTINUE;
1225 
1226 		if (!test_sta_flag(rx->sta, WLAN_STA_PS_DRIVER))
1227 			ieee80211_sta_ps_deliver_uapsd(rx->sta);
1228 		else
1229 			set_sta_flag(rx->sta, WLAN_STA_UAPSD);
1230 	}
1231 
1232 	return RX_CONTINUE;
1233 }
1234 
1235 static ieee80211_rx_result debug_noinline
1236 ieee80211_rx_h_sta_process(struct ieee80211_rx_data *rx)
1237 {
1238 	struct sta_info *sta = rx->sta;
1239 	struct sk_buff *skb = rx->skb;
1240 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
1241 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
1242 	int i;
1243 
1244 	if (!sta)
1245 		return RX_CONTINUE;
1246 
1247 	/*
1248 	 * Update last_rx only for IBSS packets which are for the current
1249 	 * BSSID and for station already AUTHORIZED to avoid keeping the
1250 	 * current IBSS network alive in cases where other STAs start
1251 	 * using different BSSID. This will also give the station another
1252 	 * chance to restart the authentication/authorization in case
1253 	 * something went wrong the first time.
1254 	 */
1255 	if (rx->sdata->vif.type == NL80211_IFTYPE_ADHOC) {
1256 		u8 *bssid = ieee80211_get_bssid(hdr, rx->skb->len,
1257 						NL80211_IFTYPE_ADHOC);
1258 		if (ether_addr_equal(bssid, rx->sdata->u.ibss.bssid) &&
1259 		    test_sta_flag(sta, WLAN_STA_AUTHORIZED)) {
1260 			sta->last_rx = jiffies;
1261 			if (ieee80211_is_data(hdr->frame_control)) {
1262 				sta->last_rx_rate_idx = status->rate_idx;
1263 				sta->last_rx_rate_flag = status->flag;
1264 				sta->last_rx_rate_vht_nss = status->vht_nss;
1265 			}
1266 		}
1267 	} else if (!is_multicast_ether_addr(hdr->addr1)) {
1268 		/*
1269 		 * Mesh beacons will update last_rx when if they are found to
1270 		 * match the current local configuration when processed.
1271 		 */
1272 		sta->last_rx = jiffies;
1273 		if (ieee80211_is_data(hdr->frame_control)) {
1274 			sta->last_rx_rate_idx = status->rate_idx;
1275 			sta->last_rx_rate_flag = status->flag;
1276 			sta->last_rx_rate_vht_nss = status->vht_nss;
1277 		}
1278 	}
1279 
1280 	if (!(status->rx_flags & IEEE80211_RX_RA_MATCH))
1281 		return RX_CONTINUE;
1282 
1283 	if (rx->sdata->vif.type == NL80211_IFTYPE_STATION)
1284 		ieee80211_sta_rx_notify(rx->sdata, hdr);
1285 
1286 	sta->rx_fragments++;
1287 	sta->rx_bytes += rx->skb->len;
1288 	if (!(status->flag & RX_FLAG_NO_SIGNAL_VAL)) {
1289 		sta->last_signal = status->signal;
1290 		ewma_add(&sta->avg_signal, -status->signal);
1291 	}
1292 
1293 	if (status->chains) {
1294 		sta->chains = status->chains;
1295 		for (i = 0; i < ARRAY_SIZE(status->chain_signal); i++) {
1296 			int signal = status->chain_signal[i];
1297 
1298 			if (!(status->chains & BIT(i)))
1299 				continue;
1300 
1301 			sta->chain_signal_last[i] = signal;
1302 			ewma_add(&sta->chain_signal_avg[i], -signal);
1303 		}
1304 	}
1305 
1306 	/*
1307 	 * Change STA power saving mode only at the end of a frame
1308 	 * exchange sequence.
1309 	 */
1310 	if (!(sta->local->hw.flags & IEEE80211_HW_AP_LINK_PS) &&
1311 	    !ieee80211_has_morefrags(hdr->frame_control) &&
1312 	    !(status->rx_flags & IEEE80211_RX_DEFERRED_RELEASE) &&
1313 	    (rx->sdata->vif.type == NL80211_IFTYPE_AP ||
1314 	     rx->sdata->vif.type == NL80211_IFTYPE_AP_VLAN)) {
1315 		if (test_sta_flag(sta, WLAN_STA_PS_STA)) {
1316 			/*
1317 			 * Ignore doze->wake transitions that are
1318 			 * indicated by non-data frames, the standard
1319 			 * is unclear here, but for example going to
1320 			 * PS mode and then scanning would cause a
1321 			 * doze->wake transition for the probe request,
1322 			 * and that is clearly undesirable.
1323 			 */
1324 			if (ieee80211_is_data(hdr->frame_control) &&
1325 			    !ieee80211_has_pm(hdr->frame_control))
1326 				sta_ps_end(sta);
1327 		} else {
1328 			if (ieee80211_has_pm(hdr->frame_control))
1329 				sta_ps_start(sta);
1330 		}
1331 	}
1332 
1333 	/* mesh power save support */
1334 	if (ieee80211_vif_is_mesh(&rx->sdata->vif))
1335 		ieee80211_mps_rx_h_sta_process(sta, hdr);
1336 
1337 	/*
1338 	 * Drop (qos-)data::nullfunc frames silently, since they
1339 	 * are used only to control station power saving mode.
1340 	 */
1341 	if (ieee80211_is_nullfunc(hdr->frame_control) ||
1342 	    ieee80211_is_qos_nullfunc(hdr->frame_control)) {
1343 		I802_DEBUG_INC(rx->local->rx_handlers_drop_nullfunc);
1344 
1345 		/*
1346 		 * If we receive a 4-addr nullfunc frame from a STA
1347 		 * that was not moved to a 4-addr STA vlan yet send
1348 		 * the event to userspace and for older hostapd drop
1349 		 * the frame to the monitor interface.
1350 		 */
1351 		if (ieee80211_has_a4(hdr->frame_control) &&
1352 		    (rx->sdata->vif.type == NL80211_IFTYPE_AP ||
1353 		     (rx->sdata->vif.type == NL80211_IFTYPE_AP_VLAN &&
1354 		      !rx->sdata->u.vlan.sta))) {
1355 			if (!test_and_set_sta_flag(sta, WLAN_STA_4ADDR_EVENT))
1356 				cfg80211_rx_unexpected_4addr_frame(
1357 					rx->sdata->dev, sta->sta.addr,
1358 					GFP_ATOMIC);
1359 			return RX_DROP_MONITOR;
1360 		}
1361 		/*
1362 		 * Update counter and free packet here to avoid
1363 		 * counting this as a dropped packed.
1364 		 */
1365 		sta->rx_packets++;
1366 		dev_kfree_skb(rx->skb);
1367 		return RX_QUEUED;
1368 	}
1369 
1370 	return RX_CONTINUE;
1371 } /* ieee80211_rx_h_sta_process */
1372 
1373 static ieee80211_rx_result debug_noinline
1374 ieee80211_rx_h_decrypt(struct ieee80211_rx_data *rx)
1375 {
1376 	struct sk_buff *skb = rx->skb;
1377 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
1378 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
1379 	int keyidx;
1380 	int hdrlen;
1381 	ieee80211_rx_result result = RX_DROP_UNUSABLE;
1382 	struct ieee80211_key *sta_ptk = NULL;
1383 	int mmie_keyidx = -1;
1384 	__le16 fc;
1385 	const struct ieee80211_cipher_scheme *cs = NULL;
1386 
1387 	/*
1388 	 * Key selection 101
1389 	 *
1390 	 * There are four types of keys:
1391 	 *  - GTK (group keys)
1392 	 *  - IGTK (group keys for management frames)
1393 	 *  - PTK (pairwise keys)
1394 	 *  - STK (station-to-station pairwise keys)
1395 	 *
1396 	 * When selecting a key, we have to distinguish between multicast
1397 	 * (including broadcast) and unicast frames, the latter can only
1398 	 * use PTKs and STKs while the former always use GTKs and IGTKs.
1399 	 * Unless, of course, actual WEP keys ("pre-RSNA") are used, then
1400 	 * unicast frames can also use key indices like GTKs. Hence, if we
1401 	 * don't have a PTK/STK we check the key index for a WEP key.
1402 	 *
1403 	 * Note that in a regular BSS, multicast frames are sent by the
1404 	 * AP only, associated stations unicast the frame to the AP first
1405 	 * which then multicasts it on their behalf.
1406 	 *
1407 	 * There is also a slight problem in IBSS mode: GTKs are negotiated
1408 	 * with each station, that is something we don't currently handle.
1409 	 * The spec seems to expect that one negotiates the same key with
1410 	 * every station but there's no such requirement; VLANs could be
1411 	 * possible.
1412 	 */
1413 
1414 	/*
1415 	 * No point in finding a key and decrypting if the frame is neither
1416 	 * addressed to us nor a multicast frame.
1417 	 */
1418 	if (!(status->rx_flags & IEEE80211_RX_RA_MATCH))
1419 		return RX_CONTINUE;
1420 
1421 	/* start without a key */
1422 	rx->key = NULL;
1423 	fc = hdr->frame_control;
1424 
1425 	if (rx->sta) {
1426 		int keyid = rx->sta->ptk_idx;
1427 
1428 		if (ieee80211_has_protected(fc) && rx->sta->cipher_scheme) {
1429 			cs = rx->sta->cipher_scheme;
1430 			keyid = iwl80211_get_cs_keyid(cs, rx->skb);
1431 			if (unlikely(keyid < 0))
1432 				return RX_DROP_UNUSABLE;
1433 		}
1434 		sta_ptk = rcu_dereference(rx->sta->ptk[keyid]);
1435 	}
1436 
1437 	if (!ieee80211_has_protected(fc))
1438 		mmie_keyidx = ieee80211_get_mmie_keyidx(rx->skb);
1439 
1440 	if (!is_multicast_ether_addr(hdr->addr1) && sta_ptk) {
1441 		rx->key = sta_ptk;
1442 		if ((status->flag & RX_FLAG_DECRYPTED) &&
1443 		    (status->flag & RX_FLAG_IV_STRIPPED))
1444 			return RX_CONTINUE;
1445 		/* Skip decryption if the frame is not protected. */
1446 		if (!ieee80211_has_protected(fc))
1447 			return RX_CONTINUE;
1448 	} else if (mmie_keyidx >= 0) {
1449 		/* Broadcast/multicast robust management frame / BIP */
1450 		if ((status->flag & RX_FLAG_DECRYPTED) &&
1451 		    (status->flag & RX_FLAG_IV_STRIPPED))
1452 			return RX_CONTINUE;
1453 
1454 		if (mmie_keyidx < NUM_DEFAULT_KEYS ||
1455 		    mmie_keyidx >= NUM_DEFAULT_KEYS + NUM_DEFAULT_MGMT_KEYS)
1456 			return RX_DROP_MONITOR; /* unexpected BIP keyidx */
1457 		if (rx->sta)
1458 			rx->key = rcu_dereference(rx->sta->gtk[mmie_keyidx]);
1459 		if (!rx->key)
1460 			rx->key = rcu_dereference(rx->sdata->keys[mmie_keyidx]);
1461 	} else if (!ieee80211_has_protected(fc)) {
1462 		/*
1463 		 * The frame was not protected, so skip decryption. However, we
1464 		 * need to set rx->key if there is a key that could have been
1465 		 * used so that the frame may be dropped if encryption would
1466 		 * have been expected.
1467 		 */
1468 		struct ieee80211_key *key = NULL;
1469 		struct ieee80211_sub_if_data *sdata = rx->sdata;
1470 		int i;
1471 
1472 		if (ieee80211_is_mgmt(fc) &&
1473 		    is_multicast_ether_addr(hdr->addr1) &&
1474 		    (key = rcu_dereference(rx->sdata->default_mgmt_key)))
1475 			rx->key = key;
1476 		else {
1477 			if (rx->sta) {
1478 				for (i = 0; i < NUM_DEFAULT_KEYS; i++) {
1479 					key = rcu_dereference(rx->sta->gtk[i]);
1480 					if (key)
1481 						break;
1482 				}
1483 			}
1484 			if (!key) {
1485 				for (i = 0; i < NUM_DEFAULT_KEYS; i++) {
1486 					key = rcu_dereference(sdata->keys[i]);
1487 					if (key)
1488 						break;
1489 				}
1490 			}
1491 			if (key)
1492 				rx->key = key;
1493 		}
1494 		return RX_CONTINUE;
1495 	} else {
1496 		u8 keyid;
1497 
1498 		/*
1499 		 * The device doesn't give us the IV so we won't be
1500 		 * able to look up the key. That's ok though, we
1501 		 * don't need to decrypt the frame, we just won't
1502 		 * be able to keep statistics accurate.
1503 		 * Except for key threshold notifications, should
1504 		 * we somehow allow the driver to tell us which key
1505 		 * the hardware used if this flag is set?
1506 		 */
1507 		if ((status->flag & RX_FLAG_DECRYPTED) &&
1508 		    (status->flag & RX_FLAG_IV_STRIPPED))
1509 			return RX_CONTINUE;
1510 
1511 		hdrlen = ieee80211_hdrlen(fc);
1512 
1513 		if (cs) {
1514 			keyidx = iwl80211_get_cs_keyid(cs, rx->skb);
1515 
1516 			if (unlikely(keyidx < 0))
1517 				return RX_DROP_UNUSABLE;
1518 		} else {
1519 			if (rx->skb->len < 8 + hdrlen)
1520 				return RX_DROP_UNUSABLE; /* TODO: count this? */
1521 			/*
1522 			 * no need to call ieee80211_wep_get_keyidx,
1523 			 * it verifies a bunch of things we've done already
1524 			 */
1525 			skb_copy_bits(rx->skb, hdrlen + 3, &keyid, 1);
1526 			keyidx = keyid >> 6;
1527 		}
1528 
1529 		/* check per-station GTK first, if multicast packet */
1530 		if (is_multicast_ether_addr(hdr->addr1) && rx->sta)
1531 			rx->key = rcu_dereference(rx->sta->gtk[keyidx]);
1532 
1533 		/* if not found, try default key */
1534 		if (!rx->key) {
1535 			rx->key = rcu_dereference(rx->sdata->keys[keyidx]);
1536 
1537 			/*
1538 			 * RSNA-protected unicast frames should always be
1539 			 * sent with pairwise or station-to-station keys,
1540 			 * but for WEP we allow using a key index as well.
1541 			 */
1542 			if (rx->key &&
1543 			    rx->key->conf.cipher != WLAN_CIPHER_SUITE_WEP40 &&
1544 			    rx->key->conf.cipher != WLAN_CIPHER_SUITE_WEP104 &&
1545 			    !is_multicast_ether_addr(hdr->addr1))
1546 				rx->key = NULL;
1547 		}
1548 	}
1549 
1550 	if (rx->key) {
1551 		if (unlikely(rx->key->flags & KEY_FLAG_TAINTED))
1552 			return RX_DROP_MONITOR;
1553 
1554 		rx->key->tx_rx_count++;
1555 		/* TODO: add threshold stuff again */
1556 	} else {
1557 		return RX_DROP_MONITOR;
1558 	}
1559 
1560 	switch (rx->key->conf.cipher) {
1561 	case WLAN_CIPHER_SUITE_WEP40:
1562 	case WLAN_CIPHER_SUITE_WEP104:
1563 		result = ieee80211_crypto_wep_decrypt(rx);
1564 		break;
1565 	case WLAN_CIPHER_SUITE_TKIP:
1566 		result = ieee80211_crypto_tkip_decrypt(rx);
1567 		break;
1568 	case WLAN_CIPHER_SUITE_CCMP:
1569 		result = ieee80211_crypto_ccmp_decrypt(rx);
1570 		break;
1571 	case WLAN_CIPHER_SUITE_AES_CMAC:
1572 		result = ieee80211_crypto_aes_cmac_decrypt(rx);
1573 		break;
1574 	default:
1575 		result = ieee80211_crypto_hw_decrypt(rx);
1576 	}
1577 
1578 	/* the hdr variable is invalid after the decrypt handlers */
1579 
1580 	/* either the frame has been decrypted or will be dropped */
1581 	status->flag |= RX_FLAG_DECRYPTED;
1582 
1583 	return result;
1584 }
1585 
1586 static inline struct ieee80211_fragment_entry *
1587 ieee80211_reassemble_add(struct ieee80211_sub_if_data *sdata,
1588 			 unsigned int frag, unsigned int seq, int rx_queue,
1589 			 struct sk_buff **skb)
1590 {
1591 	struct ieee80211_fragment_entry *entry;
1592 
1593 	entry = &sdata->fragments[sdata->fragment_next++];
1594 	if (sdata->fragment_next >= IEEE80211_FRAGMENT_MAX)
1595 		sdata->fragment_next = 0;
1596 
1597 	if (!skb_queue_empty(&entry->skb_list))
1598 		__skb_queue_purge(&entry->skb_list);
1599 
1600 	__skb_queue_tail(&entry->skb_list, *skb); /* no need for locking */
1601 	*skb = NULL;
1602 	entry->first_frag_time = jiffies;
1603 	entry->seq = seq;
1604 	entry->rx_queue = rx_queue;
1605 	entry->last_frag = frag;
1606 	entry->ccmp = 0;
1607 	entry->extra_len = 0;
1608 
1609 	return entry;
1610 }
1611 
1612 static inline struct ieee80211_fragment_entry *
1613 ieee80211_reassemble_find(struct ieee80211_sub_if_data *sdata,
1614 			  unsigned int frag, unsigned int seq,
1615 			  int rx_queue, struct ieee80211_hdr *hdr)
1616 {
1617 	struct ieee80211_fragment_entry *entry;
1618 	int i, idx;
1619 
1620 	idx = sdata->fragment_next;
1621 	for (i = 0; i < IEEE80211_FRAGMENT_MAX; i++) {
1622 		struct ieee80211_hdr *f_hdr;
1623 
1624 		idx--;
1625 		if (idx < 0)
1626 			idx = IEEE80211_FRAGMENT_MAX - 1;
1627 
1628 		entry = &sdata->fragments[idx];
1629 		if (skb_queue_empty(&entry->skb_list) || entry->seq != seq ||
1630 		    entry->rx_queue != rx_queue ||
1631 		    entry->last_frag + 1 != frag)
1632 			continue;
1633 
1634 		f_hdr = (struct ieee80211_hdr *)entry->skb_list.next->data;
1635 
1636 		/*
1637 		 * Check ftype and addresses are equal, else check next fragment
1638 		 */
1639 		if (((hdr->frame_control ^ f_hdr->frame_control) &
1640 		     cpu_to_le16(IEEE80211_FCTL_FTYPE)) ||
1641 		    !ether_addr_equal(hdr->addr1, f_hdr->addr1) ||
1642 		    !ether_addr_equal(hdr->addr2, f_hdr->addr2))
1643 			continue;
1644 
1645 		if (time_after(jiffies, entry->first_frag_time + 2 * HZ)) {
1646 			__skb_queue_purge(&entry->skb_list);
1647 			continue;
1648 		}
1649 		return entry;
1650 	}
1651 
1652 	return NULL;
1653 }
1654 
1655 static ieee80211_rx_result debug_noinline
1656 ieee80211_rx_h_defragment(struct ieee80211_rx_data *rx)
1657 {
1658 	struct ieee80211_hdr *hdr;
1659 	u16 sc;
1660 	__le16 fc;
1661 	unsigned int frag, seq;
1662 	struct ieee80211_fragment_entry *entry;
1663 	struct sk_buff *skb;
1664 	struct ieee80211_rx_status *status;
1665 
1666 	hdr = (struct ieee80211_hdr *)rx->skb->data;
1667 	fc = hdr->frame_control;
1668 
1669 	if (ieee80211_is_ctl(fc))
1670 		return RX_CONTINUE;
1671 
1672 	sc = le16_to_cpu(hdr->seq_ctrl);
1673 	frag = sc & IEEE80211_SCTL_FRAG;
1674 
1675 	if (likely((!ieee80211_has_morefrags(fc) && frag == 0) ||
1676 		   is_multicast_ether_addr(hdr->addr1))) {
1677 		/* not fragmented */
1678 		goto out;
1679 	}
1680 	I802_DEBUG_INC(rx->local->rx_handlers_fragments);
1681 
1682 	if (skb_linearize(rx->skb))
1683 		return RX_DROP_UNUSABLE;
1684 
1685 	/*
1686 	 *  skb_linearize() might change the skb->data and
1687 	 *  previously cached variables (in this case, hdr) need to
1688 	 *  be refreshed with the new data.
1689 	 */
1690 	hdr = (struct ieee80211_hdr *)rx->skb->data;
1691 	seq = (sc & IEEE80211_SCTL_SEQ) >> 4;
1692 
1693 	if (frag == 0) {
1694 		/* This is the first fragment of a new frame. */
1695 		entry = ieee80211_reassemble_add(rx->sdata, frag, seq,
1696 						 rx->seqno_idx, &(rx->skb));
1697 		if (rx->key && rx->key->conf.cipher == WLAN_CIPHER_SUITE_CCMP &&
1698 		    ieee80211_has_protected(fc)) {
1699 			int queue = rx->security_idx;
1700 			/* Store CCMP PN so that we can verify that the next
1701 			 * fragment has a sequential PN value. */
1702 			entry->ccmp = 1;
1703 			memcpy(entry->last_pn,
1704 			       rx->key->u.ccmp.rx_pn[queue],
1705 			       IEEE80211_CCMP_PN_LEN);
1706 		}
1707 		return RX_QUEUED;
1708 	}
1709 
1710 	/* This is a fragment for a frame that should already be pending in
1711 	 * fragment cache. Add this fragment to the end of the pending entry.
1712 	 */
1713 	entry = ieee80211_reassemble_find(rx->sdata, frag, seq,
1714 					  rx->seqno_idx, hdr);
1715 	if (!entry) {
1716 		I802_DEBUG_INC(rx->local->rx_handlers_drop_defrag);
1717 		return RX_DROP_MONITOR;
1718 	}
1719 
1720 	/* Verify that MPDUs within one MSDU have sequential PN values.
1721 	 * (IEEE 802.11i, 8.3.3.4.5) */
1722 	if (entry->ccmp) {
1723 		int i;
1724 		u8 pn[IEEE80211_CCMP_PN_LEN], *rpn;
1725 		int queue;
1726 		if (!rx->key || rx->key->conf.cipher != WLAN_CIPHER_SUITE_CCMP)
1727 			return RX_DROP_UNUSABLE;
1728 		memcpy(pn, entry->last_pn, IEEE80211_CCMP_PN_LEN);
1729 		for (i = IEEE80211_CCMP_PN_LEN - 1; i >= 0; i--) {
1730 			pn[i]++;
1731 			if (pn[i])
1732 				break;
1733 		}
1734 		queue = rx->security_idx;
1735 		rpn = rx->key->u.ccmp.rx_pn[queue];
1736 		if (memcmp(pn, rpn, IEEE80211_CCMP_PN_LEN))
1737 			return RX_DROP_UNUSABLE;
1738 		memcpy(entry->last_pn, pn, IEEE80211_CCMP_PN_LEN);
1739 	}
1740 
1741 	skb_pull(rx->skb, ieee80211_hdrlen(fc));
1742 	__skb_queue_tail(&entry->skb_list, rx->skb);
1743 	entry->last_frag = frag;
1744 	entry->extra_len += rx->skb->len;
1745 	if (ieee80211_has_morefrags(fc)) {
1746 		rx->skb = NULL;
1747 		return RX_QUEUED;
1748 	}
1749 
1750 	rx->skb = __skb_dequeue(&entry->skb_list);
1751 	if (skb_tailroom(rx->skb) < entry->extra_len) {
1752 		I802_DEBUG_INC(rx->local->rx_expand_skb_head2);
1753 		if (unlikely(pskb_expand_head(rx->skb, 0, entry->extra_len,
1754 					      GFP_ATOMIC))) {
1755 			I802_DEBUG_INC(rx->local->rx_handlers_drop_defrag);
1756 			__skb_queue_purge(&entry->skb_list);
1757 			return RX_DROP_UNUSABLE;
1758 		}
1759 	}
1760 	while ((skb = __skb_dequeue(&entry->skb_list))) {
1761 		memcpy(skb_put(rx->skb, skb->len), skb->data, skb->len);
1762 		dev_kfree_skb(skb);
1763 	}
1764 
1765 	/* Complete frame has been reassembled - process it now */
1766 	status = IEEE80211_SKB_RXCB(rx->skb);
1767 	status->rx_flags |= IEEE80211_RX_FRAGMENTED;
1768 
1769  out:
1770 	if (rx->sta)
1771 		rx->sta->rx_packets++;
1772 	if (is_multicast_ether_addr(hdr->addr1))
1773 		rx->local->dot11MulticastReceivedFrameCount++;
1774 	else
1775 		ieee80211_led_rx(rx->local);
1776 	return RX_CONTINUE;
1777 }
1778 
1779 static int ieee80211_802_1x_port_control(struct ieee80211_rx_data *rx)
1780 {
1781 	if (unlikely(!rx->sta || !test_sta_flag(rx->sta, WLAN_STA_AUTHORIZED)))
1782 		return -EACCES;
1783 
1784 	return 0;
1785 }
1786 
1787 static int ieee80211_drop_unencrypted(struct ieee80211_rx_data *rx, __le16 fc)
1788 {
1789 	struct sk_buff *skb = rx->skb;
1790 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
1791 
1792 	/*
1793 	 * Pass through unencrypted frames if the hardware has
1794 	 * decrypted them already.
1795 	 */
1796 	if (status->flag & RX_FLAG_DECRYPTED)
1797 		return 0;
1798 
1799 	/* Drop unencrypted frames if key is set. */
1800 	if (unlikely(!ieee80211_has_protected(fc) &&
1801 		     !ieee80211_is_nullfunc(fc) &&
1802 		     ieee80211_is_data(fc) &&
1803 		     (rx->key || rx->sdata->drop_unencrypted)))
1804 		return -EACCES;
1805 
1806 	return 0;
1807 }
1808 
1809 static int ieee80211_drop_unencrypted_mgmt(struct ieee80211_rx_data *rx)
1810 {
1811 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
1812 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
1813 	__le16 fc = hdr->frame_control;
1814 
1815 	/*
1816 	 * Pass through unencrypted frames if the hardware has
1817 	 * decrypted them already.
1818 	 */
1819 	if (status->flag & RX_FLAG_DECRYPTED)
1820 		return 0;
1821 
1822 	if (rx->sta && test_sta_flag(rx->sta, WLAN_STA_MFP)) {
1823 		if (unlikely(!ieee80211_has_protected(fc) &&
1824 			     ieee80211_is_unicast_robust_mgmt_frame(rx->skb) &&
1825 			     rx->key)) {
1826 			if (ieee80211_is_deauth(fc) ||
1827 			    ieee80211_is_disassoc(fc))
1828 				cfg80211_rx_unprot_mlme_mgmt(rx->sdata->dev,
1829 							     rx->skb->data,
1830 							     rx->skb->len);
1831 			return -EACCES;
1832 		}
1833 		/* BIP does not use Protected field, so need to check MMIE */
1834 		if (unlikely(ieee80211_is_multicast_robust_mgmt_frame(rx->skb) &&
1835 			     ieee80211_get_mmie_keyidx(rx->skb) < 0)) {
1836 			if (ieee80211_is_deauth(fc) ||
1837 			    ieee80211_is_disassoc(fc))
1838 				cfg80211_rx_unprot_mlme_mgmt(rx->sdata->dev,
1839 							     rx->skb->data,
1840 							     rx->skb->len);
1841 			return -EACCES;
1842 		}
1843 		/*
1844 		 * When using MFP, Action frames are not allowed prior to
1845 		 * having configured keys.
1846 		 */
1847 		if (unlikely(ieee80211_is_action(fc) && !rx->key &&
1848 			     ieee80211_is_robust_mgmt_frame(
1849 				     (struct ieee80211_hdr *) rx->skb->data)))
1850 			return -EACCES;
1851 	}
1852 
1853 	return 0;
1854 }
1855 
1856 static int
1857 __ieee80211_data_to_8023(struct ieee80211_rx_data *rx, bool *port_control)
1858 {
1859 	struct ieee80211_sub_if_data *sdata = rx->sdata;
1860 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
1861 	bool check_port_control = false;
1862 	struct ethhdr *ehdr;
1863 	int ret;
1864 
1865 	*port_control = false;
1866 	if (ieee80211_has_a4(hdr->frame_control) &&
1867 	    sdata->vif.type == NL80211_IFTYPE_AP_VLAN && !sdata->u.vlan.sta)
1868 		return -1;
1869 
1870 	if (sdata->vif.type == NL80211_IFTYPE_STATION &&
1871 	    !!sdata->u.mgd.use_4addr != !!ieee80211_has_a4(hdr->frame_control)) {
1872 
1873 		if (!sdata->u.mgd.use_4addr)
1874 			return -1;
1875 		else
1876 			check_port_control = true;
1877 	}
1878 
1879 	if (is_multicast_ether_addr(hdr->addr1) &&
1880 	    sdata->vif.type == NL80211_IFTYPE_AP_VLAN && sdata->u.vlan.sta)
1881 		return -1;
1882 
1883 	ret = ieee80211_data_to_8023(rx->skb, sdata->vif.addr, sdata->vif.type);
1884 	if (ret < 0)
1885 		return ret;
1886 
1887 	ehdr = (struct ethhdr *) rx->skb->data;
1888 	if (ehdr->h_proto == rx->sdata->control_port_protocol)
1889 		*port_control = true;
1890 	else if (check_port_control)
1891 		return -1;
1892 
1893 	return 0;
1894 }
1895 
1896 /*
1897  * requires that rx->skb is a frame with ethernet header
1898  */
1899 static bool ieee80211_frame_allowed(struct ieee80211_rx_data *rx, __le16 fc)
1900 {
1901 	static const u8 pae_group_addr[ETH_ALEN] __aligned(2)
1902 		= { 0x01, 0x80, 0xC2, 0x00, 0x00, 0x03 };
1903 	struct ethhdr *ehdr = (struct ethhdr *) rx->skb->data;
1904 
1905 	/*
1906 	 * Allow EAPOL frames to us/the PAE group address regardless
1907 	 * of whether the frame was encrypted or not.
1908 	 */
1909 	if (ehdr->h_proto == rx->sdata->control_port_protocol &&
1910 	    (ether_addr_equal(ehdr->h_dest, rx->sdata->vif.addr) ||
1911 	     ether_addr_equal(ehdr->h_dest, pae_group_addr)))
1912 		return true;
1913 
1914 	if (ieee80211_802_1x_port_control(rx) ||
1915 	    ieee80211_drop_unencrypted(rx, fc))
1916 		return false;
1917 
1918 	return true;
1919 }
1920 
1921 /*
1922  * requires that rx->skb is a frame with ethernet header
1923  */
1924 static void
1925 ieee80211_deliver_skb(struct ieee80211_rx_data *rx)
1926 {
1927 	struct ieee80211_sub_if_data *sdata = rx->sdata;
1928 	struct net_device *dev = sdata->dev;
1929 	struct sk_buff *skb, *xmit_skb;
1930 	struct ethhdr *ehdr = (struct ethhdr *) rx->skb->data;
1931 	struct sta_info *dsta;
1932 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
1933 
1934 	skb = rx->skb;
1935 	xmit_skb = NULL;
1936 
1937 	if ((sdata->vif.type == NL80211_IFTYPE_AP ||
1938 	     sdata->vif.type == NL80211_IFTYPE_AP_VLAN) &&
1939 	    !(sdata->flags & IEEE80211_SDATA_DONT_BRIDGE_PACKETS) &&
1940 	    (status->rx_flags & IEEE80211_RX_RA_MATCH) &&
1941 	    (sdata->vif.type != NL80211_IFTYPE_AP_VLAN || !sdata->u.vlan.sta)) {
1942 		if (is_multicast_ether_addr(ehdr->h_dest)) {
1943 			/*
1944 			 * send multicast frames both to higher layers in
1945 			 * local net stack and back to the wireless medium
1946 			 */
1947 			xmit_skb = skb_copy(skb, GFP_ATOMIC);
1948 			if (!xmit_skb)
1949 				net_info_ratelimited("%s: failed to clone multicast frame\n",
1950 						    dev->name);
1951 		} else {
1952 			dsta = sta_info_get(sdata, skb->data);
1953 			if (dsta) {
1954 				/*
1955 				 * The destination station is associated to
1956 				 * this AP (in this VLAN), so send the frame
1957 				 * directly to it and do not pass it to local
1958 				 * net stack.
1959 				 */
1960 				xmit_skb = skb;
1961 				skb = NULL;
1962 			}
1963 		}
1964 	}
1965 
1966 	if (skb) {
1967 		int align __maybe_unused;
1968 
1969 #ifndef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
1970 		/*
1971 		 * 'align' will only take the values 0 or 2 here
1972 		 * since all frames are required to be aligned
1973 		 * to 2-byte boundaries when being passed to
1974 		 * mac80211; the code here works just as well if
1975 		 * that isn't true, but mac80211 assumes it can
1976 		 * access fields as 2-byte aligned (e.g. for
1977 		 * compare_ether_addr)
1978 		 */
1979 		align = ((unsigned long)(skb->data + sizeof(struct ethhdr))) & 3;
1980 		if (align) {
1981 			if (WARN_ON(skb_headroom(skb) < 3)) {
1982 				dev_kfree_skb(skb);
1983 				skb = NULL;
1984 			} else {
1985 				u8 *data = skb->data;
1986 				size_t len = skb_headlen(skb);
1987 				skb->data -= align;
1988 				memmove(skb->data, data, len);
1989 				skb_set_tail_pointer(skb, len);
1990 			}
1991 		}
1992 #endif
1993 
1994 		if (skb) {
1995 			/* deliver to local stack */
1996 			skb->protocol = eth_type_trans(skb, dev);
1997 			memset(skb->cb, 0, sizeof(skb->cb));
1998 			netif_receive_skb(skb);
1999 		}
2000 	}
2001 
2002 	if (xmit_skb) {
2003 		/*
2004 		 * Send to wireless media and increase priority by 256 to
2005 		 * keep the received priority instead of reclassifying
2006 		 * the frame (see cfg80211_classify8021d).
2007 		 */
2008 		xmit_skb->priority += 256;
2009 		xmit_skb->protocol = htons(ETH_P_802_3);
2010 		skb_reset_network_header(xmit_skb);
2011 		skb_reset_mac_header(xmit_skb);
2012 		dev_queue_xmit(xmit_skb);
2013 	}
2014 }
2015 
2016 static ieee80211_rx_result debug_noinline
2017 ieee80211_rx_h_amsdu(struct ieee80211_rx_data *rx)
2018 {
2019 	struct net_device *dev = rx->sdata->dev;
2020 	struct sk_buff *skb = rx->skb;
2021 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
2022 	__le16 fc = hdr->frame_control;
2023 	struct sk_buff_head frame_list;
2024 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
2025 
2026 	if (unlikely(!ieee80211_is_data(fc)))
2027 		return RX_CONTINUE;
2028 
2029 	if (unlikely(!ieee80211_is_data_present(fc)))
2030 		return RX_DROP_MONITOR;
2031 
2032 	if (!(status->rx_flags & IEEE80211_RX_AMSDU))
2033 		return RX_CONTINUE;
2034 
2035 	if (ieee80211_has_a4(hdr->frame_control) &&
2036 	    rx->sdata->vif.type == NL80211_IFTYPE_AP_VLAN &&
2037 	    !rx->sdata->u.vlan.sta)
2038 		return RX_DROP_UNUSABLE;
2039 
2040 	if (is_multicast_ether_addr(hdr->addr1) &&
2041 	    ((rx->sdata->vif.type == NL80211_IFTYPE_AP_VLAN &&
2042 	      rx->sdata->u.vlan.sta) ||
2043 	     (rx->sdata->vif.type == NL80211_IFTYPE_STATION &&
2044 	      rx->sdata->u.mgd.use_4addr)))
2045 		return RX_DROP_UNUSABLE;
2046 
2047 	skb->dev = dev;
2048 	__skb_queue_head_init(&frame_list);
2049 
2050 	if (skb_linearize(skb))
2051 		return RX_DROP_UNUSABLE;
2052 
2053 	ieee80211_amsdu_to_8023s(skb, &frame_list, dev->dev_addr,
2054 				 rx->sdata->vif.type,
2055 				 rx->local->hw.extra_tx_headroom, true);
2056 
2057 	while (!skb_queue_empty(&frame_list)) {
2058 		rx->skb = __skb_dequeue(&frame_list);
2059 
2060 		if (!ieee80211_frame_allowed(rx, fc)) {
2061 			dev_kfree_skb(rx->skb);
2062 			continue;
2063 		}
2064 		dev->stats.rx_packets++;
2065 		dev->stats.rx_bytes += rx->skb->len;
2066 
2067 		ieee80211_deliver_skb(rx);
2068 	}
2069 
2070 	return RX_QUEUED;
2071 }
2072 
2073 #ifdef CONFIG_MAC80211_MESH
2074 static ieee80211_rx_result
2075 ieee80211_rx_h_mesh_fwding(struct ieee80211_rx_data *rx)
2076 {
2077 	struct ieee80211_hdr *fwd_hdr, *hdr;
2078 	struct ieee80211_tx_info *info;
2079 	struct ieee80211s_hdr *mesh_hdr;
2080 	struct sk_buff *skb = rx->skb, *fwd_skb;
2081 	struct ieee80211_local *local = rx->local;
2082 	struct ieee80211_sub_if_data *sdata = rx->sdata;
2083 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
2084 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
2085 	u16 q, hdrlen;
2086 
2087 	hdr = (struct ieee80211_hdr *) skb->data;
2088 	hdrlen = ieee80211_hdrlen(hdr->frame_control);
2089 
2090 	/* make sure fixed part of mesh header is there, also checks skb len */
2091 	if (!pskb_may_pull(rx->skb, hdrlen + 6))
2092 		return RX_DROP_MONITOR;
2093 
2094 	mesh_hdr = (struct ieee80211s_hdr *) (skb->data + hdrlen);
2095 
2096 	/* make sure full mesh header is there, also checks skb len */
2097 	if (!pskb_may_pull(rx->skb,
2098 			   hdrlen + ieee80211_get_mesh_hdrlen(mesh_hdr)))
2099 		return RX_DROP_MONITOR;
2100 
2101 	/* reload pointers */
2102 	hdr = (struct ieee80211_hdr *) skb->data;
2103 	mesh_hdr = (struct ieee80211s_hdr *) (skb->data + hdrlen);
2104 
2105 	/* frame is in RMC, don't forward */
2106 	if (ieee80211_is_data(hdr->frame_control) &&
2107 	    is_multicast_ether_addr(hdr->addr1) &&
2108 	    mesh_rmc_check(rx->sdata, hdr->addr3, mesh_hdr))
2109 		return RX_DROP_MONITOR;
2110 
2111 	if (!ieee80211_is_data(hdr->frame_control) ||
2112 	    !(status->rx_flags & IEEE80211_RX_RA_MATCH))
2113 		return RX_CONTINUE;
2114 
2115 	if (!mesh_hdr->ttl)
2116 		return RX_DROP_MONITOR;
2117 
2118 	if (mesh_hdr->flags & MESH_FLAGS_AE) {
2119 		struct mesh_path *mppath;
2120 		char *proxied_addr;
2121 		char *mpp_addr;
2122 
2123 		if (is_multicast_ether_addr(hdr->addr1)) {
2124 			mpp_addr = hdr->addr3;
2125 			proxied_addr = mesh_hdr->eaddr1;
2126 		} else if (mesh_hdr->flags & MESH_FLAGS_AE_A5_A6) {
2127 			/* has_a4 already checked in ieee80211_rx_mesh_check */
2128 			mpp_addr = hdr->addr4;
2129 			proxied_addr = mesh_hdr->eaddr2;
2130 		} else {
2131 			return RX_DROP_MONITOR;
2132 		}
2133 
2134 		rcu_read_lock();
2135 		mppath = mpp_path_lookup(sdata, proxied_addr);
2136 		if (!mppath) {
2137 			mpp_path_add(sdata, proxied_addr, mpp_addr);
2138 		} else {
2139 			spin_lock_bh(&mppath->state_lock);
2140 			if (!ether_addr_equal(mppath->mpp, mpp_addr))
2141 				memcpy(mppath->mpp, mpp_addr, ETH_ALEN);
2142 			spin_unlock_bh(&mppath->state_lock);
2143 		}
2144 		rcu_read_unlock();
2145 	}
2146 
2147 	/* Frame has reached destination.  Don't forward */
2148 	if (!is_multicast_ether_addr(hdr->addr1) &&
2149 	    ether_addr_equal(sdata->vif.addr, hdr->addr3))
2150 		return RX_CONTINUE;
2151 
2152 	q = ieee80211_select_queue_80211(sdata, skb, hdr);
2153 	if (ieee80211_queue_stopped(&local->hw, q)) {
2154 		IEEE80211_IFSTA_MESH_CTR_INC(ifmsh, dropped_frames_congestion);
2155 		return RX_DROP_MONITOR;
2156 	}
2157 	skb_set_queue_mapping(skb, q);
2158 
2159 	if (!--mesh_hdr->ttl) {
2160 		IEEE80211_IFSTA_MESH_CTR_INC(ifmsh, dropped_frames_ttl);
2161 		goto out;
2162 	}
2163 
2164 	if (!ifmsh->mshcfg.dot11MeshForwarding)
2165 		goto out;
2166 
2167 	fwd_skb = skb_copy(skb, GFP_ATOMIC);
2168 	if (!fwd_skb) {
2169 		net_info_ratelimited("%s: failed to clone mesh frame\n",
2170 				    sdata->name);
2171 		goto out;
2172 	}
2173 
2174 	fwd_hdr =  (struct ieee80211_hdr *) fwd_skb->data;
2175 	fwd_hdr->frame_control &= ~cpu_to_le16(IEEE80211_FCTL_RETRY);
2176 	info = IEEE80211_SKB_CB(fwd_skb);
2177 	memset(info, 0, sizeof(*info));
2178 	info->flags |= IEEE80211_TX_INTFL_NEED_TXPROCESSING;
2179 	info->control.vif = &rx->sdata->vif;
2180 	info->control.jiffies = jiffies;
2181 	if (is_multicast_ether_addr(fwd_hdr->addr1)) {
2182 		IEEE80211_IFSTA_MESH_CTR_INC(ifmsh, fwded_mcast);
2183 		memcpy(fwd_hdr->addr2, sdata->vif.addr, ETH_ALEN);
2184 		/* update power mode indication when forwarding */
2185 		ieee80211_mps_set_frame_flags(sdata, NULL, fwd_hdr);
2186 	} else if (!mesh_nexthop_lookup(sdata, fwd_skb)) {
2187 		/* mesh power mode flags updated in mesh_nexthop_lookup */
2188 		IEEE80211_IFSTA_MESH_CTR_INC(ifmsh, fwded_unicast);
2189 	} else {
2190 		/* unable to resolve next hop */
2191 		mesh_path_error_tx(sdata, ifmsh->mshcfg.element_ttl,
2192 				   fwd_hdr->addr3, 0,
2193 				   WLAN_REASON_MESH_PATH_NOFORWARD,
2194 				   fwd_hdr->addr2);
2195 		IEEE80211_IFSTA_MESH_CTR_INC(ifmsh, dropped_frames_no_route);
2196 		kfree_skb(fwd_skb);
2197 		return RX_DROP_MONITOR;
2198 	}
2199 
2200 	IEEE80211_IFSTA_MESH_CTR_INC(ifmsh, fwded_frames);
2201 	ieee80211_add_pending_skb(local, fwd_skb);
2202  out:
2203 	if (is_multicast_ether_addr(hdr->addr1) ||
2204 	    sdata->dev->flags & IFF_PROMISC)
2205 		return RX_CONTINUE;
2206 	else
2207 		return RX_DROP_MONITOR;
2208 }
2209 #endif
2210 
2211 static ieee80211_rx_result debug_noinline
2212 ieee80211_rx_h_data(struct ieee80211_rx_data *rx)
2213 {
2214 	struct ieee80211_sub_if_data *sdata = rx->sdata;
2215 	struct ieee80211_local *local = rx->local;
2216 	struct net_device *dev = sdata->dev;
2217 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
2218 	__le16 fc = hdr->frame_control;
2219 	bool port_control;
2220 	int err;
2221 
2222 	if (unlikely(!ieee80211_is_data(hdr->frame_control)))
2223 		return RX_CONTINUE;
2224 
2225 	if (unlikely(!ieee80211_is_data_present(hdr->frame_control)))
2226 		return RX_DROP_MONITOR;
2227 
2228 	/*
2229 	 * Send unexpected-4addr-frame event to hostapd. For older versions,
2230 	 * also drop the frame to cooked monitor interfaces.
2231 	 */
2232 	if (ieee80211_has_a4(hdr->frame_control) &&
2233 	    sdata->vif.type == NL80211_IFTYPE_AP) {
2234 		if (rx->sta &&
2235 		    !test_and_set_sta_flag(rx->sta, WLAN_STA_4ADDR_EVENT))
2236 			cfg80211_rx_unexpected_4addr_frame(
2237 				rx->sdata->dev, rx->sta->sta.addr, GFP_ATOMIC);
2238 		return RX_DROP_MONITOR;
2239 	}
2240 
2241 	err = __ieee80211_data_to_8023(rx, &port_control);
2242 	if (unlikely(err))
2243 		return RX_DROP_UNUSABLE;
2244 
2245 	if (!ieee80211_frame_allowed(rx, fc))
2246 		return RX_DROP_MONITOR;
2247 
2248 	if (rx->sdata->vif.type == NL80211_IFTYPE_AP_VLAN &&
2249 	    unlikely(port_control) && sdata->bss) {
2250 		sdata = container_of(sdata->bss, struct ieee80211_sub_if_data,
2251 				     u.ap);
2252 		dev = sdata->dev;
2253 		rx->sdata = sdata;
2254 	}
2255 
2256 	rx->skb->dev = dev;
2257 
2258 	dev->stats.rx_packets++;
2259 	dev->stats.rx_bytes += rx->skb->len;
2260 
2261 	if (local->ps_sdata && local->hw.conf.dynamic_ps_timeout > 0 &&
2262 	    !is_multicast_ether_addr(
2263 		    ((struct ethhdr *)rx->skb->data)->h_dest) &&
2264 	    (!local->scanning &&
2265 	     !test_bit(SDATA_STATE_OFFCHANNEL, &sdata->state))) {
2266 			mod_timer(&local->dynamic_ps_timer, jiffies +
2267 			 msecs_to_jiffies(local->hw.conf.dynamic_ps_timeout));
2268 	}
2269 
2270 	ieee80211_deliver_skb(rx);
2271 
2272 	return RX_QUEUED;
2273 }
2274 
2275 static ieee80211_rx_result debug_noinline
2276 ieee80211_rx_h_ctrl(struct ieee80211_rx_data *rx, struct sk_buff_head *frames)
2277 {
2278 	struct sk_buff *skb = rx->skb;
2279 	struct ieee80211_bar *bar = (struct ieee80211_bar *)skb->data;
2280 	struct tid_ampdu_rx *tid_agg_rx;
2281 	u16 start_seq_num;
2282 	u16 tid;
2283 
2284 	if (likely(!ieee80211_is_ctl(bar->frame_control)))
2285 		return RX_CONTINUE;
2286 
2287 	if (ieee80211_is_back_req(bar->frame_control)) {
2288 		struct {
2289 			__le16 control, start_seq_num;
2290 		} __packed bar_data;
2291 
2292 		if (!rx->sta)
2293 			return RX_DROP_MONITOR;
2294 
2295 		if (skb_copy_bits(skb, offsetof(struct ieee80211_bar, control),
2296 				  &bar_data, sizeof(bar_data)))
2297 			return RX_DROP_MONITOR;
2298 
2299 		tid = le16_to_cpu(bar_data.control) >> 12;
2300 
2301 		tid_agg_rx = rcu_dereference(rx->sta->ampdu_mlme.tid_rx[tid]);
2302 		if (!tid_agg_rx)
2303 			return RX_DROP_MONITOR;
2304 
2305 		start_seq_num = le16_to_cpu(bar_data.start_seq_num) >> 4;
2306 
2307 		/* reset session timer */
2308 		if (tid_agg_rx->timeout)
2309 			mod_timer(&tid_agg_rx->session_timer,
2310 				  TU_TO_EXP_TIME(tid_agg_rx->timeout));
2311 
2312 		spin_lock(&tid_agg_rx->reorder_lock);
2313 		/* release stored frames up to start of BAR */
2314 		ieee80211_release_reorder_frames(rx->sdata, tid_agg_rx,
2315 						 start_seq_num, frames);
2316 		spin_unlock(&tid_agg_rx->reorder_lock);
2317 
2318 		kfree_skb(skb);
2319 		return RX_QUEUED;
2320 	}
2321 
2322 	/*
2323 	 * After this point, we only want management frames,
2324 	 * so we can drop all remaining control frames to
2325 	 * cooked monitor interfaces.
2326 	 */
2327 	return RX_DROP_MONITOR;
2328 }
2329 
2330 static void ieee80211_process_sa_query_req(struct ieee80211_sub_if_data *sdata,
2331 					   struct ieee80211_mgmt *mgmt,
2332 					   size_t len)
2333 {
2334 	struct ieee80211_local *local = sdata->local;
2335 	struct sk_buff *skb;
2336 	struct ieee80211_mgmt *resp;
2337 
2338 	if (!ether_addr_equal(mgmt->da, sdata->vif.addr)) {
2339 		/* Not to own unicast address */
2340 		return;
2341 	}
2342 
2343 	if (!ether_addr_equal(mgmt->sa, sdata->u.mgd.bssid) ||
2344 	    !ether_addr_equal(mgmt->bssid, sdata->u.mgd.bssid)) {
2345 		/* Not from the current AP or not associated yet. */
2346 		return;
2347 	}
2348 
2349 	if (len < 24 + 1 + sizeof(resp->u.action.u.sa_query)) {
2350 		/* Too short SA Query request frame */
2351 		return;
2352 	}
2353 
2354 	skb = dev_alloc_skb(sizeof(*resp) + local->hw.extra_tx_headroom);
2355 	if (skb == NULL)
2356 		return;
2357 
2358 	skb_reserve(skb, local->hw.extra_tx_headroom);
2359 	resp = (struct ieee80211_mgmt *) skb_put(skb, 24);
2360 	memset(resp, 0, 24);
2361 	memcpy(resp->da, mgmt->sa, ETH_ALEN);
2362 	memcpy(resp->sa, sdata->vif.addr, ETH_ALEN);
2363 	memcpy(resp->bssid, sdata->u.mgd.bssid, ETH_ALEN);
2364 	resp->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
2365 					  IEEE80211_STYPE_ACTION);
2366 	skb_put(skb, 1 + sizeof(resp->u.action.u.sa_query));
2367 	resp->u.action.category = WLAN_CATEGORY_SA_QUERY;
2368 	resp->u.action.u.sa_query.action = WLAN_ACTION_SA_QUERY_RESPONSE;
2369 	memcpy(resp->u.action.u.sa_query.trans_id,
2370 	       mgmt->u.action.u.sa_query.trans_id,
2371 	       WLAN_SA_QUERY_TR_ID_LEN);
2372 
2373 	ieee80211_tx_skb(sdata, skb);
2374 }
2375 
2376 static ieee80211_rx_result debug_noinline
2377 ieee80211_rx_h_mgmt_check(struct ieee80211_rx_data *rx)
2378 {
2379 	struct ieee80211_mgmt *mgmt = (struct ieee80211_mgmt *) rx->skb->data;
2380 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
2381 
2382 	/*
2383 	 * From here on, look only at management frames.
2384 	 * Data and control frames are already handled,
2385 	 * and unknown (reserved) frames are useless.
2386 	 */
2387 	if (rx->skb->len < 24)
2388 		return RX_DROP_MONITOR;
2389 
2390 	if (!ieee80211_is_mgmt(mgmt->frame_control))
2391 		return RX_DROP_MONITOR;
2392 
2393 	if (rx->sdata->vif.type == NL80211_IFTYPE_AP &&
2394 	    ieee80211_is_beacon(mgmt->frame_control) &&
2395 	    !(rx->flags & IEEE80211_RX_BEACON_REPORTED)) {
2396 		int sig = 0;
2397 
2398 		if (rx->local->hw.flags & IEEE80211_HW_SIGNAL_DBM)
2399 			sig = status->signal;
2400 
2401 		cfg80211_report_obss_beacon(rx->local->hw.wiphy,
2402 					    rx->skb->data, rx->skb->len,
2403 					    status->freq, sig);
2404 		rx->flags |= IEEE80211_RX_BEACON_REPORTED;
2405 	}
2406 
2407 	if (!(status->rx_flags & IEEE80211_RX_RA_MATCH))
2408 		return RX_DROP_MONITOR;
2409 
2410 	if (ieee80211_drop_unencrypted_mgmt(rx))
2411 		return RX_DROP_UNUSABLE;
2412 
2413 	return RX_CONTINUE;
2414 }
2415 
2416 static ieee80211_rx_result debug_noinline
2417 ieee80211_rx_h_action(struct ieee80211_rx_data *rx)
2418 {
2419 	struct ieee80211_local *local = rx->local;
2420 	struct ieee80211_sub_if_data *sdata = rx->sdata;
2421 	struct ieee80211_mgmt *mgmt = (struct ieee80211_mgmt *) rx->skb->data;
2422 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
2423 	int len = rx->skb->len;
2424 
2425 	if (!ieee80211_is_action(mgmt->frame_control))
2426 		return RX_CONTINUE;
2427 
2428 	/* drop too small frames */
2429 	if (len < IEEE80211_MIN_ACTION_SIZE)
2430 		return RX_DROP_UNUSABLE;
2431 
2432 	if (!rx->sta && mgmt->u.action.category != WLAN_CATEGORY_PUBLIC &&
2433 	    mgmt->u.action.category != WLAN_CATEGORY_SELF_PROTECTED &&
2434 	    mgmt->u.action.category != WLAN_CATEGORY_SPECTRUM_MGMT)
2435 		return RX_DROP_UNUSABLE;
2436 
2437 	if (!(status->rx_flags & IEEE80211_RX_RA_MATCH))
2438 		return RX_DROP_UNUSABLE;
2439 
2440 	switch (mgmt->u.action.category) {
2441 	case WLAN_CATEGORY_HT:
2442 		/* reject HT action frames from stations not supporting HT */
2443 		if (!rx->sta->sta.ht_cap.ht_supported)
2444 			goto invalid;
2445 
2446 		if (sdata->vif.type != NL80211_IFTYPE_STATION &&
2447 		    sdata->vif.type != NL80211_IFTYPE_MESH_POINT &&
2448 		    sdata->vif.type != NL80211_IFTYPE_AP_VLAN &&
2449 		    sdata->vif.type != NL80211_IFTYPE_AP &&
2450 		    sdata->vif.type != NL80211_IFTYPE_ADHOC)
2451 			break;
2452 
2453 		/* verify action & smps_control/chanwidth are present */
2454 		if (len < IEEE80211_MIN_ACTION_SIZE + 2)
2455 			goto invalid;
2456 
2457 		switch (mgmt->u.action.u.ht_smps.action) {
2458 		case WLAN_HT_ACTION_SMPS: {
2459 			struct ieee80211_supported_band *sband;
2460 			enum ieee80211_smps_mode smps_mode;
2461 
2462 			/* convert to HT capability */
2463 			switch (mgmt->u.action.u.ht_smps.smps_control) {
2464 			case WLAN_HT_SMPS_CONTROL_DISABLED:
2465 				smps_mode = IEEE80211_SMPS_OFF;
2466 				break;
2467 			case WLAN_HT_SMPS_CONTROL_STATIC:
2468 				smps_mode = IEEE80211_SMPS_STATIC;
2469 				break;
2470 			case WLAN_HT_SMPS_CONTROL_DYNAMIC:
2471 				smps_mode = IEEE80211_SMPS_DYNAMIC;
2472 				break;
2473 			default:
2474 				goto invalid;
2475 			}
2476 
2477 			/* if no change do nothing */
2478 			if (rx->sta->sta.smps_mode == smps_mode)
2479 				goto handled;
2480 			rx->sta->sta.smps_mode = smps_mode;
2481 
2482 			sband = rx->local->hw.wiphy->bands[status->band];
2483 
2484 			rate_control_rate_update(local, sband, rx->sta,
2485 						 IEEE80211_RC_SMPS_CHANGED);
2486 			goto handled;
2487 		}
2488 		case WLAN_HT_ACTION_NOTIFY_CHANWIDTH: {
2489 			struct ieee80211_supported_band *sband;
2490 			u8 chanwidth = mgmt->u.action.u.ht_notify_cw.chanwidth;
2491 			enum ieee80211_sta_rx_bandwidth new_bw;
2492 
2493 			/* If it doesn't support 40 MHz it can't change ... */
2494 			if (!(rx->sta->sta.ht_cap.cap &
2495 					IEEE80211_HT_CAP_SUP_WIDTH_20_40))
2496 				goto handled;
2497 
2498 			if (chanwidth == IEEE80211_HT_CHANWIDTH_20MHZ)
2499 				new_bw = IEEE80211_STA_RX_BW_20;
2500 			else
2501 				new_bw = ieee80211_sta_cur_vht_bw(rx->sta);
2502 
2503 			if (rx->sta->sta.bandwidth == new_bw)
2504 				goto handled;
2505 
2506 			sband = rx->local->hw.wiphy->bands[status->band];
2507 
2508 			rate_control_rate_update(local, sband, rx->sta,
2509 						 IEEE80211_RC_BW_CHANGED);
2510 			goto handled;
2511 		}
2512 		default:
2513 			goto invalid;
2514 		}
2515 
2516 		break;
2517 	case WLAN_CATEGORY_PUBLIC:
2518 		if (len < IEEE80211_MIN_ACTION_SIZE + 1)
2519 			goto invalid;
2520 		if (sdata->vif.type != NL80211_IFTYPE_STATION)
2521 			break;
2522 		if (!rx->sta)
2523 			break;
2524 		if (!ether_addr_equal(mgmt->bssid, sdata->u.mgd.bssid))
2525 			break;
2526 		if (mgmt->u.action.u.ext_chan_switch.action_code !=
2527 				WLAN_PUB_ACTION_EXT_CHANSW_ANN)
2528 			break;
2529 		if (len < offsetof(struct ieee80211_mgmt,
2530 				   u.action.u.ext_chan_switch.variable))
2531 			goto invalid;
2532 		goto queue;
2533 	case WLAN_CATEGORY_VHT:
2534 		if (sdata->vif.type != NL80211_IFTYPE_STATION &&
2535 		    sdata->vif.type != NL80211_IFTYPE_MESH_POINT &&
2536 		    sdata->vif.type != NL80211_IFTYPE_AP_VLAN &&
2537 		    sdata->vif.type != NL80211_IFTYPE_AP &&
2538 		    sdata->vif.type != NL80211_IFTYPE_ADHOC)
2539 			break;
2540 
2541 		/* verify action code is present */
2542 		if (len < IEEE80211_MIN_ACTION_SIZE + 1)
2543 			goto invalid;
2544 
2545 		switch (mgmt->u.action.u.vht_opmode_notif.action_code) {
2546 		case WLAN_VHT_ACTION_OPMODE_NOTIF: {
2547 			u8 opmode;
2548 
2549 			/* verify opmode is present */
2550 			if (len < IEEE80211_MIN_ACTION_SIZE + 2)
2551 				goto invalid;
2552 
2553 			opmode = mgmt->u.action.u.vht_opmode_notif.operating_mode;
2554 
2555 			ieee80211_vht_handle_opmode(rx->sdata, rx->sta,
2556 						    opmode, status->band,
2557 						    false);
2558 			goto handled;
2559 		}
2560 		default:
2561 			break;
2562 		}
2563 		break;
2564 	case WLAN_CATEGORY_BACK:
2565 		if (sdata->vif.type != NL80211_IFTYPE_STATION &&
2566 		    sdata->vif.type != NL80211_IFTYPE_MESH_POINT &&
2567 		    sdata->vif.type != NL80211_IFTYPE_AP_VLAN &&
2568 		    sdata->vif.type != NL80211_IFTYPE_AP &&
2569 		    sdata->vif.type != NL80211_IFTYPE_ADHOC)
2570 			break;
2571 
2572 		/* verify action_code is present */
2573 		if (len < IEEE80211_MIN_ACTION_SIZE + 1)
2574 			break;
2575 
2576 		switch (mgmt->u.action.u.addba_req.action_code) {
2577 		case WLAN_ACTION_ADDBA_REQ:
2578 			if (len < (IEEE80211_MIN_ACTION_SIZE +
2579 				   sizeof(mgmt->u.action.u.addba_req)))
2580 				goto invalid;
2581 			break;
2582 		case WLAN_ACTION_ADDBA_RESP:
2583 			if (len < (IEEE80211_MIN_ACTION_SIZE +
2584 				   sizeof(mgmt->u.action.u.addba_resp)))
2585 				goto invalid;
2586 			break;
2587 		case WLAN_ACTION_DELBA:
2588 			if (len < (IEEE80211_MIN_ACTION_SIZE +
2589 				   sizeof(mgmt->u.action.u.delba)))
2590 				goto invalid;
2591 			break;
2592 		default:
2593 			goto invalid;
2594 		}
2595 
2596 		goto queue;
2597 	case WLAN_CATEGORY_SPECTRUM_MGMT:
2598 		/* verify action_code is present */
2599 		if (len < IEEE80211_MIN_ACTION_SIZE + 1)
2600 			break;
2601 
2602 		switch (mgmt->u.action.u.measurement.action_code) {
2603 		case WLAN_ACTION_SPCT_MSR_REQ:
2604 			if (status->band != IEEE80211_BAND_5GHZ)
2605 				break;
2606 
2607 			if (len < (IEEE80211_MIN_ACTION_SIZE +
2608 				   sizeof(mgmt->u.action.u.measurement)))
2609 				break;
2610 
2611 			if (sdata->vif.type != NL80211_IFTYPE_STATION)
2612 				break;
2613 
2614 			ieee80211_process_measurement_req(sdata, mgmt, len);
2615 			goto handled;
2616 		case WLAN_ACTION_SPCT_CHL_SWITCH: {
2617 			u8 *bssid;
2618 			if (len < (IEEE80211_MIN_ACTION_SIZE +
2619 				   sizeof(mgmt->u.action.u.chan_switch)))
2620 				break;
2621 
2622 			if (sdata->vif.type != NL80211_IFTYPE_STATION &&
2623 			    sdata->vif.type != NL80211_IFTYPE_ADHOC &&
2624 			    sdata->vif.type != NL80211_IFTYPE_MESH_POINT)
2625 				break;
2626 
2627 			if (sdata->vif.type == NL80211_IFTYPE_STATION)
2628 				bssid = sdata->u.mgd.bssid;
2629 			else if (sdata->vif.type == NL80211_IFTYPE_ADHOC)
2630 				bssid = sdata->u.ibss.bssid;
2631 			else if (sdata->vif.type == NL80211_IFTYPE_MESH_POINT)
2632 				bssid = mgmt->sa;
2633 			else
2634 				break;
2635 
2636 			if (!ether_addr_equal(mgmt->bssid, bssid))
2637 				break;
2638 
2639 			goto queue;
2640 			}
2641 		}
2642 		break;
2643 	case WLAN_CATEGORY_SA_QUERY:
2644 		if (len < (IEEE80211_MIN_ACTION_SIZE +
2645 			   sizeof(mgmt->u.action.u.sa_query)))
2646 			break;
2647 
2648 		switch (mgmt->u.action.u.sa_query.action) {
2649 		case WLAN_ACTION_SA_QUERY_REQUEST:
2650 			if (sdata->vif.type != NL80211_IFTYPE_STATION)
2651 				break;
2652 			ieee80211_process_sa_query_req(sdata, mgmt, len);
2653 			goto handled;
2654 		}
2655 		break;
2656 	case WLAN_CATEGORY_SELF_PROTECTED:
2657 		if (len < (IEEE80211_MIN_ACTION_SIZE +
2658 			   sizeof(mgmt->u.action.u.self_prot.action_code)))
2659 			break;
2660 
2661 		switch (mgmt->u.action.u.self_prot.action_code) {
2662 		case WLAN_SP_MESH_PEERING_OPEN:
2663 		case WLAN_SP_MESH_PEERING_CLOSE:
2664 		case WLAN_SP_MESH_PEERING_CONFIRM:
2665 			if (!ieee80211_vif_is_mesh(&sdata->vif))
2666 				goto invalid;
2667 			if (sdata->u.mesh.user_mpm)
2668 				/* userspace handles this frame */
2669 				break;
2670 			goto queue;
2671 		case WLAN_SP_MGK_INFORM:
2672 		case WLAN_SP_MGK_ACK:
2673 			if (!ieee80211_vif_is_mesh(&sdata->vif))
2674 				goto invalid;
2675 			break;
2676 		}
2677 		break;
2678 	case WLAN_CATEGORY_MESH_ACTION:
2679 		if (len < (IEEE80211_MIN_ACTION_SIZE +
2680 			   sizeof(mgmt->u.action.u.mesh_action.action_code)))
2681 			break;
2682 
2683 		if (!ieee80211_vif_is_mesh(&sdata->vif))
2684 			break;
2685 		if (mesh_action_is_path_sel(mgmt) &&
2686 		    !mesh_path_sel_is_hwmp(sdata))
2687 			break;
2688 		goto queue;
2689 	}
2690 
2691 	return RX_CONTINUE;
2692 
2693  invalid:
2694 	status->rx_flags |= IEEE80211_RX_MALFORMED_ACTION_FRM;
2695 	/* will return in the next handlers */
2696 	return RX_CONTINUE;
2697 
2698  handled:
2699 	if (rx->sta)
2700 		rx->sta->rx_packets++;
2701 	dev_kfree_skb(rx->skb);
2702 	return RX_QUEUED;
2703 
2704  queue:
2705 	rx->skb->pkt_type = IEEE80211_SDATA_QUEUE_TYPE_FRAME;
2706 	skb_queue_tail(&sdata->skb_queue, rx->skb);
2707 	ieee80211_queue_work(&local->hw, &sdata->work);
2708 	if (rx->sta)
2709 		rx->sta->rx_packets++;
2710 	return RX_QUEUED;
2711 }
2712 
2713 static ieee80211_rx_result debug_noinline
2714 ieee80211_rx_h_userspace_mgmt(struct ieee80211_rx_data *rx)
2715 {
2716 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
2717 	int sig = 0;
2718 
2719 	/* skip known-bad action frames and return them in the next handler */
2720 	if (status->rx_flags & IEEE80211_RX_MALFORMED_ACTION_FRM)
2721 		return RX_CONTINUE;
2722 
2723 	/*
2724 	 * Getting here means the kernel doesn't know how to handle
2725 	 * it, but maybe userspace does ... include returned frames
2726 	 * so userspace can register for those to know whether ones
2727 	 * it transmitted were processed or returned.
2728 	 */
2729 
2730 	if (rx->local->hw.flags & IEEE80211_HW_SIGNAL_DBM)
2731 		sig = status->signal;
2732 
2733 	if (cfg80211_rx_mgmt(&rx->sdata->wdev, status->freq, sig,
2734 			     rx->skb->data, rx->skb->len, 0, GFP_ATOMIC)) {
2735 		if (rx->sta)
2736 			rx->sta->rx_packets++;
2737 		dev_kfree_skb(rx->skb);
2738 		return RX_QUEUED;
2739 	}
2740 
2741 	return RX_CONTINUE;
2742 }
2743 
2744 static ieee80211_rx_result debug_noinline
2745 ieee80211_rx_h_action_return(struct ieee80211_rx_data *rx)
2746 {
2747 	struct ieee80211_local *local = rx->local;
2748 	struct ieee80211_mgmt *mgmt = (struct ieee80211_mgmt *) rx->skb->data;
2749 	struct sk_buff *nskb;
2750 	struct ieee80211_sub_if_data *sdata = rx->sdata;
2751 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
2752 
2753 	if (!ieee80211_is_action(mgmt->frame_control))
2754 		return RX_CONTINUE;
2755 
2756 	/*
2757 	 * For AP mode, hostapd is responsible for handling any action
2758 	 * frames that we didn't handle, including returning unknown
2759 	 * ones. For all other modes we will return them to the sender,
2760 	 * setting the 0x80 bit in the action category, as required by
2761 	 * 802.11-2012 9.24.4.
2762 	 * Newer versions of hostapd shall also use the management frame
2763 	 * registration mechanisms, but older ones still use cooked
2764 	 * monitor interfaces so push all frames there.
2765 	 */
2766 	if (!(status->rx_flags & IEEE80211_RX_MALFORMED_ACTION_FRM) &&
2767 	    (sdata->vif.type == NL80211_IFTYPE_AP ||
2768 	     sdata->vif.type == NL80211_IFTYPE_AP_VLAN))
2769 		return RX_DROP_MONITOR;
2770 
2771 	if (is_multicast_ether_addr(mgmt->da))
2772 		return RX_DROP_MONITOR;
2773 
2774 	/* do not return rejected action frames */
2775 	if (mgmt->u.action.category & 0x80)
2776 		return RX_DROP_UNUSABLE;
2777 
2778 	nskb = skb_copy_expand(rx->skb, local->hw.extra_tx_headroom, 0,
2779 			       GFP_ATOMIC);
2780 	if (nskb) {
2781 		struct ieee80211_mgmt *nmgmt = (void *)nskb->data;
2782 
2783 		nmgmt->u.action.category |= 0x80;
2784 		memcpy(nmgmt->da, nmgmt->sa, ETH_ALEN);
2785 		memcpy(nmgmt->sa, rx->sdata->vif.addr, ETH_ALEN);
2786 
2787 		memset(nskb->cb, 0, sizeof(nskb->cb));
2788 
2789 		if (rx->sdata->vif.type == NL80211_IFTYPE_P2P_DEVICE) {
2790 			struct ieee80211_tx_info *info = IEEE80211_SKB_CB(nskb);
2791 
2792 			info->flags = IEEE80211_TX_CTL_TX_OFFCHAN |
2793 				      IEEE80211_TX_INTFL_OFFCHAN_TX_OK |
2794 				      IEEE80211_TX_CTL_NO_CCK_RATE;
2795 			if (local->hw.flags & IEEE80211_HW_QUEUE_CONTROL)
2796 				info->hw_queue =
2797 					local->hw.offchannel_tx_hw_queue;
2798 		}
2799 
2800 		__ieee80211_tx_skb_tid_band(rx->sdata, nskb, 7,
2801 					    status->band);
2802 	}
2803 	dev_kfree_skb(rx->skb);
2804 	return RX_QUEUED;
2805 }
2806 
2807 static ieee80211_rx_result debug_noinline
2808 ieee80211_rx_h_mgmt(struct ieee80211_rx_data *rx)
2809 {
2810 	struct ieee80211_sub_if_data *sdata = rx->sdata;
2811 	struct ieee80211_mgmt *mgmt = (void *)rx->skb->data;
2812 	__le16 stype;
2813 
2814 	stype = mgmt->frame_control & cpu_to_le16(IEEE80211_FCTL_STYPE);
2815 
2816 	if (!ieee80211_vif_is_mesh(&sdata->vif) &&
2817 	    sdata->vif.type != NL80211_IFTYPE_ADHOC &&
2818 	    sdata->vif.type != NL80211_IFTYPE_STATION)
2819 		return RX_DROP_MONITOR;
2820 
2821 	switch (stype) {
2822 	case cpu_to_le16(IEEE80211_STYPE_AUTH):
2823 	case cpu_to_le16(IEEE80211_STYPE_BEACON):
2824 	case cpu_to_le16(IEEE80211_STYPE_PROBE_RESP):
2825 		/* process for all: mesh, mlme, ibss */
2826 		break;
2827 	case cpu_to_le16(IEEE80211_STYPE_ASSOC_RESP):
2828 	case cpu_to_le16(IEEE80211_STYPE_REASSOC_RESP):
2829 	case cpu_to_le16(IEEE80211_STYPE_DEAUTH):
2830 	case cpu_to_le16(IEEE80211_STYPE_DISASSOC):
2831 		if (is_multicast_ether_addr(mgmt->da) &&
2832 		    !is_broadcast_ether_addr(mgmt->da))
2833 			return RX_DROP_MONITOR;
2834 
2835 		/* process only for station */
2836 		if (sdata->vif.type != NL80211_IFTYPE_STATION)
2837 			return RX_DROP_MONITOR;
2838 		break;
2839 	case cpu_to_le16(IEEE80211_STYPE_PROBE_REQ):
2840 		/* process only for ibss and mesh */
2841 		if (sdata->vif.type != NL80211_IFTYPE_ADHOC &&
2842 		    sdata->vif.type != NL80211_IFTYPE_MESH_POINT)
2843 			return RX_DROP_MONITOR;
2844 		break;
2845 	default:
2846 		return RX_DROP_MONITOR;
2847 	}
2848 
2849 	/* queue up frame and kick off work to process it */
2850 	rx->skb->pkt_type = IEEE80211_SDATA_QUEUE_TYPE_FRAME;
2851 	skb_queue_tail(&sdata->skb_queue, rx->skb);
2852 	ieee80211_queue_work(&rx->local->hw, &sdata->work);
2853 	if (rx->sta)
2854 		rx->sta->rx_packets++;
2855 
2856 	return RX_QUEUED;
2857 }
2858 
2859 /* TODO: use IEEE80211_RX_FRAGMENTED */
2860 static void ieee80211_rx_cooked_monitor(struct ieee80211_rx_data *rx,
2861 					struct ieee80211_rate *rate)
2862 {
2863 	struct ieee80211_sub_if_data *sdata;
2864 	struct ieee80211_local *local = rx->local;
2865 	struct sk_buff *skb = rx->skb, *skb2;
2866 	struct net_device *prev_dev = NULL;
2867 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
2868 	int needed_headroom;
2869 
2870 	/*
2871 	 * If cooked monitor has been processed already, then
2872 	 * don't do it again. If not, set the flag.
2873 	 */
2874 	if (rx->flags & IEEE80211_RX_CMNTR)
2875 		goto out_free_skb;
2876 	rx->flags |= IEEE80211_RX_CMNTR;
2877 
2878 	/* If there are no cooked monitor interfaces, just free the SKB */
2879 	if (!local->cooked_mntrs)
2880 		goto out_free_skb;
2881 
2882 	/* room for the radiotap header based on driver features */
2883 	needed_headroom = ieee80211_rx_radiotap_space(local, status);
2884 
2885 	if (skb_headroom(skb) < needed_headroom &&
2886 	    pskb_expand_head(skb, needed_headroom, 0, GFP_ATOMIC))
2887 		goto out_free_skb;
2888 
2889 	/* prepend radiotap information */
2890 	ieee80211_add_rx_radiotap_header(local, skb, rate, needed_headroom,
2891 					 false);
2892 
2893 	skb_set_mac_header(skb, 0);
2894 	skb->ip_summed = CHECKSUM_UNNECESSARY;
2895 	skb->pkt_type = PACKET_OTHERHOST;
2896 	skb->protocol = htons(ETH_P_802_2);
2897 
2898 	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
2899 		if (!ieee80211_sdata_running(sdata))
2900 			continue;
2901 
2902 		if (sdata->vif.type != NL80211_IFTYPE_MONITOR ||
2903 		    !(sdata->u.mntr_flags & MONITOR_FLAG_COOK_FRAMES))
2904 			continue;
2905 
2906 		if (prev_dev) {
2907 			skb2 = skb_clone(skb, GFP_ATOMIC);
2908 			if (skb2) {
2909 				skb2->dev = prev_dev;
2910 				netif_receive_skb(skb2);
2911 			}
2912 		}
2913 
2914 		prev_dev = sdata->dev;
2915 		sdata->dev->stats.rx_packets++;
2916 		sdata->dev->stats.rx_bytes += skb->len;
2917 	}
2918 
2919 	if (prev_dev) {
2920 		skb->dev = prev_dev;
2921 		netif_receive_skb(skb);
2922 		return;
2923 	}
2924 
2925  out_free_skb:
2926 	dev_kfree_skb(skb);
2927 }
2928 
2929 static void ieee80211_rx_handlers_result(struct ieee80211_rx_data *rx,
2930 					 ieee80211_rx_result res)
2931 {
2932 	switch (res) {
2933 	case RX_DROP_MONITOR:
2934 		I802_DEBUG_INC(rx->sdata->local->rx_handlers_drop);
2935 		if (rx->sta)
2936 			rx->sta->rx_dropped++;
2937 		/* fall through */
2938 	case RX_CONTINUE: {
2939 		struct ieee80211_rate *rate = NULL;
2940 		struct ieee80211_supported_band *sband;
2941 		struct ieee80211_rx_status *status;
2942 
2943 		status = IEEE80211_SKB_RXCB((rx->skb));
2944 
2945 		sband = rx->local->hw.wiphy->bands[status->band];
2946 		if (!(status->flag & RX_FLAG_HT) &&
2947 		    !(status->flag & RX_FLAG_VHT))
2948 			rate = &sband->bitrates[status->rate_idx];
2949 
2950 		ieee80211_rx_cooked_monitor(rx, rate);
2951 		break;
2952 		}
2953 	case RX_DROP_UNUSABLE:
2954 		I802_DEBUG_INC(rx->sdata->local->rx_handlers_drop);
2955 		if (rx->sta)
2956 			rx->sta->rx_dropped++;
2957 		dev_kfree_skb(rx->skb);
2958 		break;
2959 	case RX_QUEUED:
2960 		I802_DEBUG_INC(rx->sdata->local->rx_handlers_queued);
2961 		break;
2962 	}
2963 }
2964 
2965 static void ieee80211_rx_handlers(struct ieee80211_rx_data *rx,
2966 				  struct sk_buff_head *frames)
2967 {
2968 	ieee80211_rx_result res = RX_DROP_MONITOR;
2969 	struct sk_buff *skb;
2970 
2971 #define CALL_RXH(rxh)			\
2972 	do {				\
2973 		res = rxh(rx);		\
2974 		if (res != RX_CONTINUE)	\
2975 			goto rxh_next;  \
2976 	} while (0);
2977 
2978 	spin_lock_bh(&rx->local->rx_path_lock);
2979 
2980 	while ((skb = __skb_dequeue(frames))) {
2981 		/*
2982 		 * all the other fields are valid across frames
2983 		 * that belong to an aMPDU since they are on the
2984 		 * same TID from the same station
2985 		 */
2986 		rx->skb = skb;
2987 
2988 		CALL_RXH(ieee80211_rx_h_check_more_data)
2989 		CALL_RXH(ieee80211_rx_h_uapsd_and_pspoll)
2990 		CALL_RXH(ieee80211_rx_h_sta_process)
2991 		CALL_RXH(ieee80211_rx_h_decrypt)
2992 		CALL_RXH(ieee80211_rx_h_defragment)
2993 		CALL_RXH(ieee80211_rx_h_michael_mic_verify)
2994 		/* must be after MMIC verify so header is counted in MPDU mic */
2995 #ifdef CONFIG_MAC80211_MESH
2996 		if (ieee80211_vif_is_mesh(&rx->sdata->vif))
2997 			CALL_RXH(ieee80211_rx_h_mesh_fwding);
2998 #endif
2999 		CALL_RXH(ieee80211_rx_h_amsdu)
3000 		CALL_RXH(ieee80211_rx_h_data)
3001 
3002 		/* special treatment -- needs the queue */
3003 		res = ieee80211_rx_h_ctrl(rx, frames);
3004 		if (res != RX_CONTINUE)
3005 			goto rxh_next;
3006 
3007 		CALL_RXH(ieee80211_rx_h_mgmt_check)
3008 		CALL_RXH(ieee80211_rx_h_action)
3009 		CALL_RXH(ieee80211_rx_h_userspace_mgmt)
3010 		CALL_RXH(ieee80211_rx_h_action_return)
3011 		CALL_RXH(ieee80211_rx_h_mgmt)
3012 
3013  rxh_next:
3014 		ieee80211_rx_handlers_result(rx, res);
3015 
3016 #undef CALL_RXH
3017 	}
3018 
3019 	spin_unlock_bh(&rx->local->rx_path_lock);
3020 }
3021 
3022 static void ieee80211_invoke_rx_handlers(struct ieee80211_rx_data *rx)
3023 {
3024 	struct sk_buff_head reorder_release;
3025 	ieee80211_rx_result res = RX_DROP_MONITOR;
3026 
3027 	__skb_queue_head_init(&reorder_release);
3028 
3029 #define CALL_RXH(rxh)			\
3030 	do {				\
3031 		res = rxh(rx);		\
3032 		if (res != RX_CONTINUE)	\
3033 			goto rxh_next;  \
3034 	} while (0);
3035 
3036 	CALL_RXH(ieee80211_rx_h_check)
3037 
3038 	ieee80211_rx_reorder_ampdu(rx, &reorder_release);
3039 
3040 	ieee80211_rx_handlers(rx, &reorder_release);
3041 	return;
3042 
3043  rxh_next:
3044 	ieee80211_rx_handlers_result(rx, res);
3045 
3046 #undef CALL_RXH
3047 }
3048 
3049 /*
3050  * This function makes calls into the RX path, therefore
3051  * it has to be invoked under RCU read lock.
3052  */
3053 void ieee80211_release_reorder_timeout(struct sta_info *sta, int tid)
3054 {
3055 	struct sk_buff_head frames;
3056 	struct ieee80211_rx_data rx = {
3057 		.sta = sta,
3058 		.sdata = sta->sdata,
3059 		.local = sta->local,
3060 		/* This is OK -- must be QoS data frame */
3061 		.security_idx = tid,
3062 		.seqno_idx = tid,
3063 		.flags = 0,
3064 	};
3065 	struct tid_ampdu_rx *tid_agg_rx;
3066 
3067 	tid_agg_rx = rcu_dereference(sta->ampdu_mlme.tid_rx[tid]);
3068 	if (!tid_agg_rx)
3069 		return;
3070 
3071 	__skb_queue_head_init(&frames);
3072 
3073 	spin_lock(&tid_agg_rx->reorder_lock);
3074 	ieee80211_sta_reorder_release(sta->sdata, tid_agg_rx, &frames);
3075 	spin_unlock(&tid_agg_rx->reorder_lock);
3076 
3077 	ieee80211_rx_handlers(&rx, &frames);
3078 }
3079 
3080 /* main receive path */
3081 
3082 static int prepare_for_handlers(struct ieee80211_rx_data *rx,
3083 				struct ieee80211_hdr *hdr)
3084 {
3085 	struct ieee80211_sub_if_data *sdata = rx->sdata;
3086 	struct sk_buff *skb = rx->skb;
3087 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
3088 	u8 *bssid = ieee80211_get_bssid(hdr, skb->len, sdata->vif.type);
3089 	int multicast = is_multicast_ether_addr(hdr->addr1);
3090 
3091 	switch (sdata->vif.type) {
3092 	case NL80211_IFTYPE_STATION:
3093 		if (!bssid && !sdata->u.mgd.use_4addr)
3094 			return 0;
3095 		if (!multicast &&
3096 		    !ether_addr_equal(sdata->vif.addr, hdr->addr1)) {
3097 			if (!(sdata->dev->flags & IFF_PROMISC) ||
3098 			    sdata->u.mgd.use_4addr)
3099 				return 0;
3100 			status->rx_flags &= ~IEEE80211_RX_RA_MATCH;
3101 		}
3102 		break;
3103 	case NL80211_IFTYPE_ADHOC:
3104 		if (!bssid)
3105 			return 0;
3106 		if (ether_addr_equal(sdata->vif.addr, hdr->addr2) ||
3107 		    ether_addr_equal(sdata->u.ibss.bssid, hdr->addr2))
3108 			return 0;
3109 		if (ieee80211_is_beacon(hdr->frame_control)) {
3110 			return 1;
3111 		} else if (!ieee80211_bssid_match(bssid, sdata->u.ibss.bssid)) {
3112 			return 0;
3113 		} else if (!multicast &&
3114 			   !ether_addr_equal(sdata->vif.addr, hdr->addr1)) {
3115 			if (!(sdata->dev->flags & IFF_PROMISC))
3116 				return 0;
3117 			status->rx_flags &= ~IEEE80211_RX_RA_MATCH;
3118 		} else if (!rx->sta) {
3119 			int rate_idx;
3120 			if (status->flag & (RX_FLAG_HT | RX_FLAG_VHT))
3121 				rate_idx = 0; /* TODO: HT/VHT rates */
3122 			else
3123 				rate_idx = status->rate_idx;
3124 			ieee80211_ibss_rx_no_sta(sdata, bssid, hdr->addr2,
3125 						 BIT(rate_idx));
3126 		}
3127 		break;
3128 	case NL80211_IFTYPE_MESH_POINT:
3129 		if (!multicast &&
3130 		    !ether_addr_equal(sdata->vif.addr, hdr->addr1)) {
3131 			if (!(sdata->dev->flags & IFF_PROMISC))
3132 				return 0;
3133 
3134 			status->rx_flags &= ~IEEE80211_RX_RA_MATCH;
3135 		}
3136 		break;
3137 	case NL80211_IFTYPE_AP_VLAN:
3138 	case NL80211_IFTYPE_AP:
3139 		if (!bssid) {
3140 			if (!ether_addr_equal(sdata->vif.addr, hdr->addr1))
3141 				return 0;
3142 		} else if (!ieee80211_bssid_match(bssid, sdata->vif.addr)) {
3143 			/*
3144 			 * Accept public action frames even when the
3145 			 * BSSID doesn't match, this is used for P2P
3146 			 * and location updates. Note that mac80211
3147 			 * itself never looks at these frames.
3148 			 */
3149 			if (!multicast &&
3150 			    !ether_addr_equal(sdata->vif.addr, hdr->addr1))
3151 				return 0;
3152 			if (ieee80211_is_public_action(hdr, skb->len))
3153 				return 1;
3154 			if (!ieee80211_is_beacon(hdr->frame_control))
3155 				return 0;
3156 			status->rx_flags &= ~IEEE80211_RX_RA_MATCH;
3157 		}
3158 		break;
3159 	case NL80211_IFTYPE_WDS:
3160 		if (bssid || !ieee80211_is_data(hdr->frame_control))
3161 			return 0;
3162 		if (!ether_addr_equal(sdata->u.wds.remote_addr, hdr->addr2))
3163 			return 0;
3164 		break;
3165 	case NL80211_IFTYPE_P2P_DEVICE:
3166 		if (!ieee80211_is_public_action(hdr, skb->len) &&
3167 		    !ieee80211_is_probe_req(hdr->frame_control) &&
3168 		    !ieee80211_is_probe_resp(hdr->frame_control) &&
3169 		    !ieee80211_is_beacon(hdr->frame_control))
3170 			return 0;
3171 		if (!ether_addr_equal(sdata->vif.addr, hdr->addr1) &&
3172 		    !multicast)
3173 			status->rx_flags &= ~IEEE80211_RX_RA_MATCH;
3174 		break;
3175 	default:
3176 		/* should never get here */
3177 		WARN_ON_ONCE(1);
3178 		break;
3179 	}
3180 
3181 	return 1;
3182 }
3183 
3184 /*
3185  * This function returns whether or not the SKB
3186  * was destined for RX processing or not, which,
3187  * if consume is true, is equivalent to whether
3188  * or not the skb was consumed.
3189  */
3190 static bool ieee80211_prepare_and_rx_handle(struct ieee80211_rx_data *rx,
3191 					    struct sk_buff *skb, bool consume)
3192 {
3193 	struct ieee80211_local *local = rx->local;
3194 	struct ieee80211_sub_if_data *sdata = rx->sdata;
3195 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
3196 	struct ieee80211_hdr *hdr = (void *)skb->data;
3197 	int prepares;
3198 
3199 	rx->skb = skb;
3200 	status->rx_flags |= IEEE80211_RX_RA_MATCH;
3201 	prepares = prepare_for_handlers(rx, hdr);
3202 
3203 	if (!prepares)
3204 		return false;
3205 
3206 	if (!consume) {
3207 		skb = skb_copy(skb, GFP_ATOMIC);
3208 		if (!skb) {
3209 			if (net_ratelimit())
3210 				wiphy_debug(local->hw.wiphy,
3211 					"failed to copy skb for %s\n",
3212 					sdata->name);
3213 			return true;
3214 		}
3215 
3216 		rx->skb = skb;
3217 	}
3218 
3219 	ieee80211_invoke_rx_handlers(rx);
3220 	return true;
3221 }
3222 
3223 /*
3224  * This is the actual Rx frames handler. as it blongs to Rx path it must
3225  * be called with rcu_read_lock protection.
3226  */
3227 static void __ieee80211_rx_handle_packet(struct ieee80211_hw *hw,
3228 					 struct sk_buff *skb)
3229 {
3230 	struct ieee80211_local *local = hw_to_local(hw);
3231 	struct ieee80211_sub_if_data *sdata;
3232 	struct ieee80211_hdr *hdr;
3233 	__le16 fc;
3234 	struct ieee80211_rx_data rx;
3235 	struct ieee80211_sub_if_data *prev;
3236 	struct sta_info *sta, *tmp, *prev_sta;
3237 	int err = 0;
3238 
3239 	fc = ((struct ieee80211_hdr *)skb->data)->frame_control;
3240 	memset(&rx, 0, sizeof(rx));
3241 	rx.skb = skb;
3242 	rx.local = local;
3243 
3244 	if (ieee80211_is_data(fc) || ieee80211_is_mgmt(fc))
3245 		local->dot11ReceivedFragmentCount++;
3246 
3247 	if (ieee80211_is_mgmt(fc)) {
3248 		/* drop frame if too short for header */
3249 		if (skb->len < ieee80211_hdrlen(fc))
3250 			err = -ENOBUFS;
3251 		else
3252 			err = skb_linearize(skb);
3253 	} else {
3254 		err = !pskb_may_pull(skb, ieee80211_hdrlen(fc));
3255 	}
3256 
3257 	if (err) {
3258 		dev_kfree_skb(skb);
3259 		return;
3260 	}
3261 
3262 	hdr = (struct ieee80211_hdr *)skb->data;
3263 	ieee80211_parse_qos(&rx);
3264 	ieee80211_verify_alignment(&rx);
3265 
3266 	if (unlikely(ieee80211_is_probe_resp(hdr->frame_control) ||
3267 		     ieee80211_is_beacon(hdr->frame_control)))
3268 		ieee80211_scan_rx(local, skb);
3269 
3270 	if (ieee80211_is_data(fc)) {
3271 		prev_sta = NULL;
3272 
3273 		for_each_sta_info(local, hdr->addr2, sta, tmp) {
3274 			if (!prev_sta) {
3275 				prev_sta = sta;
3276 				continue;
3277 			}
3278 
3279 			rx.sta = prev_sta;
3280 			rx.sdata = prev_sta->sdata;
3281 			ieee80211_prepare_and_rx_handle(&rx, skb, false);
3282 
3283 			prev_sta = sta;
3284 		}
3285 
3286 		if (prev_sta) {
3287 			rx.sta = prev_sta;
3288 			rx.sdata = prev_sta->sdata;
3289 
3290 			if (ieee80211_prepare_and_rx_handle(&rx, skb, true))
3291 				return;
3292 			goto out;
3293 		}
3294 	}
3295 
3296 	prev = NULL;
3297 
3298 	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
3299 		if (!ieee80211_sdata_running(sdata))
3300 			continue;
3301 
3302 		if (sdata->vif.type == NL80211_IFTYPE_MONITOR ||
3303 		    sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
3304 			continue;
3305 
3306 		/*
3307 		 * frame is destined for this interface, but if it's
3308 		 * not also for the previous one we handle that after
3309 		 * the loop to avoid copying the SKB once too much
3310 		 */
3311 
3312 		if (!prev) {
3313 			prev = sdata;
3314 			continue;
3315 		}
3316 
3317 		rx.sta = sta_info_get_bss(prev, hdr->addr2);
3318 		rx.sdata = prev;
3319 		ieee80211_prepare_and_rx_handle(&rx, skb, false);
3320 
3321 		prev = sdata;
3322 	}
3323 
3324 	if (prev) {
3325 		rx.sta = sta_info_get_bss(prev, hdr->addr2);
3326 		rx.sdata = prev;
3327 
3328 		if (ieee80211_prepare_and_rx_handle(&rx, skb, true))
3329 			return;
3330 	}
3331 
3332  out:
3333 	dev_kfree_skb(skb);
3334 }
3335 
3336 /*
3337  * This is the receive path handler. It is called by a low level driver when an
3338  * 802.11 MPDU is received from the hardware.
3339  */
3340 void ieee80211_rx(struct ieee80211_hw *hw, struct sk_buff *skb)
3341 {
3342 	struct ieee80211_local *local = hw_to_local(hw);
3343 	struct ieee80211_rate *rate = NULL;
3344 	struct ieee80211_supported_band *sband;
3345 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
3346 
3347 	WARN_ON_ONCE(softirq_count() == 0);
3348 
3349 	if (WARN_ON(status->band >= IEEE80211_NUM_BANDS))
3350 		goto drop;
3351 
3352 	sband = local->hw.wiphy->bands[status->band];
3353 	if (WARN_ON(!sband))
3354 		goto drop;
3355 
3356 	/*
3357 	 * If we're suspending, it is possible although not too likely
3358 	 * that we'd be receiving frames after having already partially
3359 	 * quiesced the stack. We can't process such frames then since
3360 	 * that might, for example, cause stations to be added or other
3361 	 * driver callbacks be invoked.
3362 	 */
3363 	if (unlikely(local->quiescing || local->suspended))
3364 		goto drop;
3365 
3366 	/* We might be during a HW reconfig, prevent Rx for the same reason */
3367 	if (unlikely(local->in_reconfig))
3368 		goto drop;
3369 
3370 	/*
3371 	 * The same happens when we're not even started,
3372 	 * but that's worth a warning.
3373 	 */
3374 	if (WARN_ON(!local->started))
3375 		goto drop;
3376 
3377 	if (likely(!(status->flag & RX_FLAG_FAILED_PLCP_CRC))) {
3378 		/*
3379 		 * Validate the rate, unless a PLCP error means that
3380 		 * we probably can't have a valid rate here anyway.
3381 		 */
3382 
3383 		if (status->flag & RX_FLAG_HT) {
3384 			/*
3385 			 * rate_idx is MCS index, which can be [0-76]
3386 			 * as documented on:
3387 			 *
3388 			 * http://wireless.kernel.org/en/developers/Documentation/ieee80211/802.11n
3389 			 *
3390 			 * Anything else would be some sort of driver or
3391 			 * hardware error. The driver should catch hardware
3392 			 * errors.
3393 			 */
3394 			if (WARN(status->rate_idx > 76,
3395 				 "Rate marked as an HT rate but passed "
3396 				 "status->rate_idx is not "
3397 				 "an MCS index [0-76]: %d (0x%02x)\n",
3398 				 status->rate_idx,
3399 				 status->rate_idx))
3400 				goto drop;
3401 		} else if (status->flag & RX_FLAG_VHT) {
3402 			if (WARN_ONCE(status->rate_idx > 9 ||
3403 				      !status->vht_nss ||
3404 				      status->vht_nss > 8,
3405 				      "Rate marked as a VHT rate but data is invalid: MCS: %d, NSS: %d\n",
3406 				      status->rate_idx, status->vht_nss))
3407 				goto drop;
3408 		} else {
3409 			if (WARN_ON(status->rate_idx >= sband->n_bitrates))
3410 				goto drop;
3411 			rate = &sband->bitrates[status->rate_idx];
3412 		}
3413 	}
3414 
3415 	status->rx_flags = 0;
3416 
3417 	/*
3418 	 * key references and virtual interfaces are protected using RCU
3419 	 * and this requires that we are in a read-side RCU section during
3420 	 * receive processing
3421 	 */
3422 	rcu_read_lock();
3423 
3424 	/*
3425 	 * Frames with failed FCS/PLCP checksum are not returned,
3426 	 * all other frames are returned without radiotap header
3427 	 * if it was previously present.
3428 	 * Also, frames with less than 16 bytes are dropped.
3429 	 */
3430 	skb = ieee80211_rx_monitor(local, skb, rate);
3431 	if (!skb) {
3432 		rcu_read_unlock();
3433 		return;
3434 	}
3435 
3436 	ieee80211_tpt_led_trig_rx(local,
3437 			((struct ieee80211_hdr *)skb->data)->frame_control,
3438 			skb->len);
3439 	__ieee80211_rx_handle_packet(hw, skb);
3440 
3441 	rcu_read_unlock();
3442 
3443 	return;
3444  drop:
3445 	kfree_skb(skb);
3446 }
3447 EXPORT_SYMBOL(ieee80211_rx);
3448 
3449 /* This is a version of the rx handler that can be called from hard irq
3450  * context. Post the skb on the queue and schedule the tasklet */
3451 void ieee80211_rx_irqsafe(struct ieee80211_hw *hw, struct sk_buff *skb)
3452 {
3453 	struct ieee80211_local *local = hw_to_local(hw);
3454 
3455 	BUILD_BUG_ON(sizeof(struct ieee80211_rx_status) > sizeof(skb->cb));
3456 
3457 	skb->pkt_type = IEEE80211_RX_MSG;
3458 	skb_queue_tail(&local->skb_queue, skb);
3459 	tasklet_schedule(&local->tasklet);
3460 }
3461 EXPORT_SYMBOL(ieee80211_rx_irqsafe);
3462