xref: /openbmc/linux/net/mac80211/rx.c (revision 77d84ff8)
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 ieee80211_rx_result ieee80211_rx_mesh_check(struct ieee80211_rx_data *rx)
642 {
643 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
644 	char *dev_addr = rx->sdata->vif.addr;
645 
646 	if (ieee80211_is_data(hdr->frame_control)) {
647 		if (is_multicast_ether_addr(hdr->addr1)) {
648 			if (ieee80211_has_tods(hdr->frame_control) ||
649 			    !ieee80211_has_fromds(hdr->frame_control))
650 				return RX_DROP_MONITOR;
651 			if (ether_addr_equal(hdr->addr3, dev_addr))
652 				return RX_DROP_MONITOR;
653 		} else {
654 			if (!ieee80211_has_a4(hdr->frame_control))
655 				return RX_DROP_MONITOR;
656 			if (ether_addr_equal(hdr->addr4, dev_addr))
657 				return RX_DROP_MONITOR;
658 		}
659 	}
660 
661 	/* If there is not an established peer link and this is not a peer link
662 	 * establisment frame, beacon or probe, drop the frame.
663 	 */
664 
665 	if (!rx->sta || sta_plink_state(rx->sta) != NL80211_PLINK_ESTAB) {
666 		struct ieee80211_mgmt *mgmt;
667 
668 		if (!ieee80211_is_mgmt(hdr->frame_control))
669 			return RX_DROP_MONITOR;
670 
671 		if (ieee80211_is_action(hdr->frame_control)) {
672 			u8 category;
673 
674 			/* make sure category field is present */
675 			if (rx->skb->len < IEEE80211_MIN_ACTION_SIZE)
676 				return RX_DROP_MONITOR;
677 
678 			mgmt = (struct ieee80211_mgmt *)hdr;
679 			category = mgmt->u.action.category;
680 			if (category != WLAN_CATEGORY_MESH_ACTION &&
681 			    category != WLAN_CATEGORY_SELF_PROTECTED)
682 				return RX_DROP_MONITOR;
683 			return RX_CONTINUE;
684 		}
685 
686 		if (ieee80211_is_probe_req(hdr->frame_control) ||
687 		    ieee80211_is_probe_resp(hdr->frame_control) ||
688 		    ieee80211_is_beacon(hdr->frame_control) ||
689 		    ieee80211_is_auth(hdr->frame_control))
690 			return RX_CONTINUE;
691 
692 		return RX_DROP_MONITOR;
693 	}
694 
695 	return RX_CONTINUE;
696 }
697 
698 static void ieee80211_release_reorder_frame(struct ieee80211_sub_if_data *sdata,
699 					    struct tid_ampdu_rx *tid_agg_rx,
700 					    int index,
701 					    struct sk_buff_head *frames)
702 {
703 	struct sk_buff *skb = tid_agg_rx->reorder_buf[index];
704 	struct ieee80211_rx_status *status;
705 
706 	lockdep_assert_held(&tid_agg_rx->reorder_lock);
707 
708 	if (!skb)
709 		goto no_frame;
710 
711 	/* release the frame from the reorder ring buffer */
712 	tid_agg_rx->stored_mpdu_num--;
713 	tid_agg_rx->reorder_buf[index] = NULL;
714 	status = IEEE80211_SKB_RXCB(skb);
715 	status->rx_flags |= IEEE80211_RX_DEFERRED_RELEASE;
716 	__skb_queue_tail(frames, skb);
717 
718 no_frame:
719 	tid_agg_rx->head_seq_num = ieee80211_sn_inc(tid_agg_rx->head_seq_num);
720 }
721 
722 static void ieee80211_release_reorder_frames(struct ieee80211_sub_if_data *sdata,
723 					     struct tid_ampdu_rx *tid_agg_rx,
724 					     u16 head_seq_num,
725 					     struct sk_buff_head *frames)
726 {
727 	int index;
728 
729 	lockdep_assert_held(&tid_agg_rx->reorder_lock);
730 
731 	while (ieee80211_sn_less(tid_agg_rx->head_seq_num, head_seq_num)) {
732 		index = ieee80211_sn_sub(tid_agg_rx->head_seq_num,
733 					 tid_agg_rx->ssn) %
734 							tid_agg_rx->buf_size;
735 		ieee80211_release_reorder_frame(sdata, tid_agg_rx, index,
736 						frames);
737 	}
738 }
739 
740 /*
741  * Timeout (in jiffies) for skb's that are waiting in the RX reorder buffer. If
742  * the skb was added to the buffer longer than this time ago, the earlier
743  * frames that have not yet been received are assumed to be lost and the skb
744  * can be released for processing. This may also release other skb's from the
745  * reorder buffer if there are no additional gaps between the frames.
746  *
747  * Callers must hold tid_agg_rx->reorder_lock.
748  */
749 #define HT_RX_REORDER_BUF_TIMEOUT (HZ / 10)
750 
751 static void ieee80211_sta_reorder_release(struct ieee80211_sub_if_data *sdata,
752 					  struct tid_ampdu_rx *tid_agg_rx,
753 					  struct sk_buff_head *frames)
754 {
755 	int index, j;
756 
757 	lockdep_assert_held(&tid_agg_rx->reorder_lock);
758 
759 	/* release the buffer until next missing frame */
760 	index = ieee80211_sn_sub(tid_agg_rx->head_seq_num,
761 				 tid_agg_rx->ssn) % tid_agg_rx->buf_size;
762 	if (!tid_agg_rx->reorder_buf[index] &&
763 	    tid_agg_rx->stored_mpdu_num) {
764 		/*
765 		 * No buffers ready to be released, but check whether any
766 		 * frames in the reorder buffer have timed out.
767 		 */
768 		int skipped = 1;
769 		for (j = (index + 1) % tid_agg_rx->buf_size; j != index;
770 		     j = (j + 1) % tid_agg_rx->buf_size) {
771 			if (!tid_agg_rx->reorder_buf[j]) {
772 				skipped++;
773 				continue;
774 			}
775 			if (skipped &&
776 			    !time_after(jiffies, tid_agg_rx->reorder_time[j] +
777 					HT_RX_REORDER_BUF_TIMEOUT))
778 				goto set_release_timer;
779 
780 			ht_dbg_ratelimited(sdata,
781 					   "release an RX reorder frame due to timeout on earlier frames\n");
782 			ieee80211_release_reorder_frame(sdata, tid_agg_rx, j,
783 							frames);
784 
785 			/*
786 			 * Increment the head seq# also for the skipped slots.
787 			 */
788 			tid_agg_rx->head_seq_num =
789 				(tid_agg_rx->head_seq_num +
790 				 skipped) & IEEE80211_SN_MASK;
791 			skipped = 0;
792 		}
793 	} else while (tid_agg_rx->reorder_buf[index]) {
794 		ieee80211_release_reorder_frame(sdata, tid_agg_rx, index,
795 						frames);
796 		index =	ieee80211_sn_sub(tid_agg_rx->head_seq_num,
797 					 tid_agg_rx->ssn) %
798 							tid_agg_rx->buf_size;
799 	}
800 
801 	if (tid_agg_rx->stored_mpdu_num) {
802 		j = index = ieee80211_sn_sub(tid_agg_rx->head_seq_num,
803 					     tid_agg_rx->ssn) %
804 							tid_agg_rx->buf_size;
805 
806 		for (; j != (index - 1) % tid_agg_rx->buf_size;
807 		     j = (j + 1) % tid_agg_rx->buf_size) {
808 			if (tid_agg_rx->reorder_buf[j])
809 				break;
810 		}
811 
812  set_release_timer:
813 
814 		mod_timer(&tid_agg_rx->reorder_timer,
815 			  tid_agg_rx->reorder_time[j] + 1 +
816 			  HT_RX_REORDER_BUF_TIMEOUT);
817 	} else {
818 		del_timer(&tid_agg_rx->reorder_timer);
819 	}
820 }
821 
822 /*
823  * As this function belongs to the RX path it must be under
824  * rcu_read_lock protection. It returns false if the frame
825  * can be processed immediately, true if it was consumed.
826  */
827 static bool ieee80211_sta_manage_reorder_buf(struct ieee80211_sub_if_data *sdata,
828 					     struct tid_ampdu_rx *tid_agg_rx,
829 					     struct sk_buff *skb,
830 					     struct sk_buff_head *frames)
831 {
832 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
833 	u16 sc = le16_to_cpu(hdr->seq_ctrl);
834 	u16 mpdu_seq_num = (sc & IEEE80211_SCTL_SEQ) >> 4;
835 	u16 head_seq_num, buf_size;
836 	int index;
837 	bool ret = true;
838 
839 	spin_lock(&tid_agg_rx->reorder_lock);
840 
841 	buf_size = tid_agg_rx->buf_size;
842 	head_seq_num = tid_agg_rx->head_seq_num;
843 
844 	/* frame with out of date sequence number */
845 	if (ieee80211_sn_less(mpdu_seq_num, head_seq_num)) {
846 		dev_kfree_skb(skb);
847 		goto out;
848 	}
849 
850 	/*
851 	 * If frame the sequence number exceeds our buffering window
852 	 * size release some previous frames to make room for this one.
853 	 */
854 	if (!ieee80211_sn_less(mpdu_seq_num, head_seq_num + buf_size)) {
855 		head_seq_num = ieee80211_sn_inc(
856 				ieee80211_sn_sub(mpdu_seq_num, buf_size));
857 		/* release stored frames up to new head to stack */
858 		ieee80211_release_reorder_frames(sdata, tid_agg_rx,
859 						 head_seq_num, frames);
860 	}
861 
862 	/* Now the new frame is always in the range of the reordering buffer */
863 
864 	index = ieee80211_sn_sub(mpdu_seq_num,
865 				 tid_agg_rx->ssn) % tid_agg_rx->buf_size;
866 
867 	/* check if we already stored this frame */
868 	if (tid_agg_rx->reorder_buf[index]) {
869 		dev_kfree_skb(skb);
870 		goto out;
871 	}
872 
873 	/*
874 	 * If the current MPDU is in the right order and nothing else
875 	 * is stored we can process it directly, no need to buffer it.
876 	 * If it is first but there's something stored, we may be able
877 	 * to release frames after this one.
878 	 */
879 	if (mpdu_seq_num == tid_agg_rx->head_seq_num &&
880 	    tid_agg_rx->stored_mpdu_num == 0) {
881 		tid_agg_rx->head_seq_num =
882 			ieee80211_sn_inc(tid_agg_rx->head_seq_num);
883 		ret = false;
884 		goto out;
885 	}
886 
887 	/* put the frame in the reordering buffer */
888 	tid_agg_rx->reorder_buf[index] = skb;
889 	tid_agg_rx->reorder_time[index] = jiffies;
890 	tid_agg_rx->stored_mpdu_num++;
891 	ieee80211_sta_reorder_release(sdata, tid_agg_rx, frames);
892 
893  out:
894 	spin_unlock(&tid_agg_rx->reorder_lock);
895 	return ret;
896 }
897 
898 /*
899  * Reorder MPDUs from A-MPDUs, keeping them on a buffer. Returns
900  * true if the MPDU was buffered, false if it should be processed.
901  */
902 static void ieee80211_rx_reorder_ampdu(struct ieee80211_rx_data *rx,
903 				       struct sk_buff_head *frames)
904 {
905 	struct sk_buff *skb = rx->skb;
906 	struct ieee80211_local *local = rx->local;
907 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
908 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
909 	struct sta_info *sta = rx->sta;
910 	struct tid_ampdu_rx *tid_agg_rx;
911 	u16 sc;
912 	u8 tid, ack_policy;
913 
914 	if (!ieee80211_is_data_qos(hdr->frame_control) ||
915 	    is_multicast_ether_addr(hdr->addr1))
916 		goto dont_reorder;
917 
918 	/*
919 	 * filter the QoS data rx stream according to
920 	 * STA/TID and check if this STA/TID is on aggregation
921 	 */
922 
923 	if (!sta)
924 		goto dont_reorder;
925 
926 	ack_policy = *ieee80211_get_qos_ctl(hdr) &
927 		     IEEE80211_QOS_CTL_ACK_POLICY_MASK;
928 	tid = *ieee80211_get_qos_ctl(hdr) & IEEE80211_QOS_CTL_TID_MASK;
929 
930 	tid_agg_rx = rcu_dereference(sta->ampdu_mlme.tid_rx[tid]);
931 	if (!tid_agg_rx)
932 		goto dont_reorder;
933 
934 	/* qos null data frames are excluded */
935 	if (unlikely(hdr->frame_control & cpu_to_le16(IEEE80211_STYPE_NULLFUNC)))
936 		goto dont_reorder;
937 
938 	/* not part of a BA session */
939 	if (ack_policy != IEEE80211_QOS_CTL_ACK_POLICY_BLOCKACK &&
940 	    ack_policy != IEEE80211_QOS_CTL_ACK_POLICY_NORMAL)
941 		goto dont_reorder;
942 
943 	/* not actually part of this BA session */
944 	if (!(status->rx_flags & IEEE80211_RX_RA_MATCH))
945 		goto dont_reorder;
946 
947 	/* new, potentially un-ordered, ampdu frame - process it */
948 
949 	/* reset session timer */
950 	if (tid_agg_rx->timeout)
951 		tid_agg_rx->last_rx = jiffies;
952 
953 	/* if this mpdu is fragmented - terminate rx aggregation session */
954 	sc = le16_to_cpu(hdr->seq_ctrl);
955 	if (sc & IEEE80211_SCTL_FRAG) {
956 		skb->pkt_type = IEEE80211_SDATA_QUEUE_TYPE_FRAME;
957 		skb_queue_tail(&rx->sdata->skb_queue, skb);
958 		ieee80211_queue_work(&local->hw, &rx->sdata->work);
959 		return;
960 	}
961 
962 	/*
963 	 * No locking needed -- we will only ever process one
964 	 * RX packet at a time, and thus own tid_agg_rx. All
965 	 * other code manipulating it needs to (and does) make
966 	 * sure that we cannot get to it any more before doing
967 	 * anything with it.
968 	 */
969 	if (ieee80211_sta_manage_reorder_buf(rx->sdata, tid_agg_rx, skb,
970 					     frames))
971 		return;
972 
973  dont_reorder:
974 	__skb_queue_tail(frames, skb);
975 }
976 
977 static ieee80211_rx_result debug_noinline
978 ieee80211_rx_h_check(struct ieee80211_rx_data *rx)
979 {
980 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
981 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
982 
983 	/*
984 	 * Drop duplicate 802.11 retransmissions
985 	 * (IEEE 802.11-2012: 9.3.2.10 "Duplicate detection and recovery")
986 	 */
987 	if (rx->skb->len >= 24 && rx->sta &&
988 	    !ieee80211_is_ctl(hdr->frame_control) &&
989 	    !ieee80211_is_qos_nullfunc(hdr->frame_control) &&
990 	    !is_multicast_ether_addr(hdr->addr1)) {
991 		if (unlikely(ieee80211_has_retry(hdr->frame_control) &&
992 			     rx->sta->last_seq_ctrl[rx->seqno_idx] ==
993 			     hdr->seq_ctrl)) {
994 			if (status->rx_flags & IEEE80211_RX_RA_MATCH) {
995 				rx->local->dot11FrameDuplicateCount++;
996 				rx->sta->num_duplicates++;
997 			}
998 			return RX_DROP_UNUSABLE;
999 		} else if (!(status->flag & RX_FLAG_AMSDU_MORE)) {
1000 			rx->sta->last_seq_ctrl[rx->seqno_idx] = hdr->seq_ctrl;
1001 		}
1002 	}
1003 
1004 	if (unlikely(rx->skb->len < 16)) {
1005 		I802_DEBUG_INC(rx->local->rx_handlers_drop_short);
1006 		return RX_DROP_MONITOR;
1007 	}
1008 
1009 	/* Drop disallowed frame classes based on STA auth/assoc state;
1010 	 * IEEE 802.11, Chap 5.5.
1011 	 *
1012 	 * mac80211 filters only based on association state, i.e. it drops
1013 	 * Class 3 frames from not associated stations. hostapd sends
1014 	 * deauth/disassoc frames when needed. In addition, hostapd is
1015 	 * responsible for filtering on both auth and assoc states.
1016 	 */
1017 
1018 	if (ieee80211_vif_is_mesh(&rx->sdata->vif))
1019 		return ieee80211_rx_mesh_check(rx);
1020 
1021 	if (unlikely((ieee80211_is_data(hdr->frame_control) ||
1022 		      ieee80211_is_pspoll(hdr->frame_control)) &&
1023 		     rx->sdata->vif.type != NL80211_IFTYPE_ADHOC &&
1024 		     rx->sdata->vif.type != NL80211_IFTYPE_WDS &&
1025 		     (!rx->sta || !test_sta_flag(rx->sta, WLAN_STA_ASSOC)))) {
1026 		/*
1027 		 * accept port control frames from the AP even when it's not
1028 		 * yet marked ASSOC to prevent a race where we don't set the
1029 		 * assoc bit quickly enough before it sends the first frame
1030 		 */
1031 		if (rx->sta && rx->sdata->vif.type == NL80211_IFTYPE_STATION &&
1032 		    ieee80211_is_data_present(hdr->frame_control)) {
1033 			unsigned int hdrlen;
1034 			__be16 ethertype;
1035 
1036 			hdrlen = ieee80211_hdrlen(hdr->frame_control);
1037 
1038 			if (rx->skb->len < hdrlen + 8)
1039 				return RX_DROP_MONITOR;
1040 
1041 			skb_copy_bits(rx->skb, hdrlen + 6, &ethertype, 2);
1042 			if (ethertype == rx->sdata->control_port_protocol)
1043 				return RX_CONTINUE;
1044 		}
1045 
1046 		if (rx->sdata->vif.type == NL80211_IFTYPE_AP &&
1047 		    cfg80211_rx_spurious_frame(rx->sdata->dev,
1048 					       hdr->addr2,
1049 					       GFP_ATOMIC))
1050 			return RX_DROP_UNUSABLE;
1051 
1052 		return RX_DROP_MONITOR;
1053 	}
1054 
1055 	return RX_CONTINUE;
1056 }
1057 
1058 
1059 static ieee80211_rx_result debug_noinline
1060 ieee80211_rx_h_check_more_data(struct ieee80211_rx_data *rx)
1061 {
1062 	struct ieee80211_local *local;
1063 	struct ieee80211_hdr *hdr;
1064 	struct sk_buff *skb;
1065 
1066 	local = rx->local;
1067 	skb = rx->skb;
1068 	hdr = (struct ieee80211_hdr *) skb->data;
1069 
1070 	if (!local->pspolling)
1071 		return RX_CONTINUE;
1072 
1073 	if (!ieee80211_has_fromds(hdr->frame_control))
1074 		/* this is not from AP */
1075 		return RX_CONTINUE;
1076 
1077 	if (!ieee80211_is_data(hdr->frame_control))
1078 		return RX_CONTINUE;
1079 
1080 	if (!ieee80211_has_moredata(hdr->frame_control)) {
1081 		/* AP has no more frames buffered for us */
1082 		local->pspolling = false;
1083 		return RX_CONTINUE;
1084 	}
1085 
1086 	/* more data bit is set, let's request a new frame from the AP */
1087 	ieee80211_send_pspoll(local, rx->sdata);
1088 
1089 	return RX_CONTINUE;
1090 }
1091 
1092 static void sta_ps_start(struct sta_info *sta)
1093 {
1094 	struct ieee80211_sub_if_data *sdata = sta->sdata;
1095 	struct ieee80211_local *local = sdata->local;
1096 	struct ps_data *ps;
1097 
1098 	if (sta->sdata->vif.type == NL80211_IFTYPE_AP ||
1099 	    sta->sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
1100 		ps = &sdata->bss->ps;
1101 	else
1102 		return;
1103 
1104 	atomic_inc(&ps->num_sta_ps);
1105 	set_sta_flag(sta, WLAN_STA_PS_STA);
1106 	if (!(local->hw.flags & IEEE80211_HW_AP_LINK_PS))
1107 		drv_sta_notify(local, sdata, STA_NOTIFY_SLEEP, &sta->sta);
1108 	ps_dbg(sdata, "STA %pM aid %d enters power save mode\n",
1109 	       sta->sta.addr, sta->sta.aid);
1110 }
1111 
1112 static void sta_ps_end(struct sta_info *sta)
1113 {
1114 	ps_dbg(sta->sdata, "STA %pM aid %d exits power save mode\n",
1115 	       sta->sta.addr, sta->sta.aid);
1116 
1117 	if (test_sta_flag(sta, WLAN_STA_PS_DRIVER)) {
1118 		ps_dbg(sta->sdata, "STA %pM aid %d driver-ps-blocked\n",
1119 		       sta->sta.addr, sta->sta.aid);
1120 		return;
1121 	}
1122 
1123 	ieee80211_sta_ps_deliver_wakeup(sta);
1124 }
1125 
1126 int ieee80211_sta_ps_transition(struct ieee80211_sta *sta, bool start)
1127 {
1128 	struct sta_info *sta_inf = container_of(sta, struct sta_info, sta);
1129 	bool in_ps;
1130 
1131 	WARN_ON(!(sta_inf->local->hw.flags & IEEE80211_HW_AP_LINK_PS));
1132 
1133 	/* Don't let the same PS state be set twice */
1134 	in_ps = test_sta_flag(sta_inf, WLAN_STA_PS_STA);
1135 	if ((start && in_ps) || (!start && !in_ps))
1136 		return -EINVAL;
1137 
1138 	if (start)
1139 		sta_ps_start(sta_inf);
1140 	else
1141 		sta_ps_end(sta_inf);
1142 
1143 	return 0;
1144 }
1145 EXPORT_SYMBOL(ieee80211_sta_ps_transition);
1146 
1147 static ieee80211_rx_result debug_noinline
1148 ieee80211_rx_h_uapsd_and_pspoll(struct ieee80211_rx_data *rx)
1149 {
1150 	struct ieee80211_sub_if_data *sdata = rx->sdata;
1151 	struct ieee80211_hdr *hdr = (void *)rx->skb->data;
1152 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
1153 	int tid, ac;
1154 
1155 	if (!rx->sta || !(status->rx_flags & IEEE80211_RX_RA_MATCH))
1156 		return RX_CONTINUE;
1157 
1158 	if (sdata->vif.type != NL80211_IFTYPE_AP &&
1159 	    sdata->vif.type != NL80211_IFTYPE_AP_VLAN)
1160 		return RX_CONTINUE;
1161 
1162 	/*
1163 	 * The device handles station powersave, so don't do anything about
1164 	 * uAPSD and PS-Poll frames (the latter shouldn't even come up from
1165 	 * it to mac80211 since they're handled.)
1166 	 */
1167 	if (sdata->local->hw.flags & IEEE80211_HW_AP_LINK_PS)
1168 		return RX_CONTINUE;
1169 
1170 	/*
1171 	 * Don't do anything if the station isn't already asleep. In
1172 	 * the uAPSD case, the station will probably be marked asleep,
1173 	 * in the PS-Poll case the station must be confused ...
1174 	 */
1175 	if (!test_sta_flag(rx->sta, WLAN_STA_PS_STA))
1176 		return RX_CONTINUE;
1177 
1178 	if (unlikely(ieee80211_is_pspoll(hdr->frame_control))) {
1179 		if (!test_sta_flag(rx->sta, WLAN_STA_SP)) {
1180 			if (!test_sta_flag(rx->sta, WLAN_STA_PS_DRIVER))
1181 				ieee80211_sta_ps_deliver_poll_response(rx->sta);
1182 			else
1183 				set_sta_flag(rx->sta, WLAN_STA_PSPOLL);
1184 		}
1185 
1186 		/* Free PS Poll skb here instead of returning RX_DROP that would
1187 		 * count as an dropped frame. */
1188 		dev_kfree_skb(rx->skb);
1189 
1190 		return RX_QUEUED;
1191 	} else if (!ieee80211_has_morefrags(hdr->frame_control) &&
1192 		   !(status->rx_flags & IEEE80211_RX_DEFERRED_RELEASE) &&
1193 		   ieee80211_has_pm(hdr->frame_control) &&
1194 		   (ieee80211_is_data_qos(hdr->frame_control) ||
1195 		    ieee80211_is_qos_nullfunc(hdr->frame_control))) {
1196 		tid = *ieee80211_get_qos_ctl(hdr) & IEEE80211_QOS_CTL_TID_MASK;
1197 		ac = ieee802_1d_to_ac[tid & 7];
1198 
1199 		/*
1200 		 * If this AC is not trigger-enabled do nothing.
1201 		 *
1202 		 * NB: This could/should check a separate bitmap of trigger-
1203 		 * enabled queues, but for now we only implement uAPSD w/o
1204 		 * TSPEC changes to the ACs, so they're always the same.
1205 		 */
1206 		if (!(rx->sta->sta.uapsd_queues & BIT(ac)))
1207 			return RX_CONTINUE;
1208 
1209 		/* if we are in a service period, do nothing */
1210 		if (test_sta_flag(rx->sta, WLAN_STA_SP))
1211 			return RX_CONTINUE;
1212 
1213 		if (!test_sta_flag(rx->sta, WLAN_STA_PS_DRIVER))
1214 			ieee80211_sta_ps_deliver_uapsd(rx->sta);
1215 		else
1216 			set_sta_flag(rx->sta, WLAN_STA_UAPSD);
1217 	}
1218 
1219 	return RX_CONTINUE;
1220 }
1221 
1222 static ieee80211_rx_result debug_noinline
1223 ieee80211_rx_h_sta_process(struct ieee80211_rx_data *rx)
1224 {
1225 	struct sta_info *sta = rx->sta;
1226 	struct sk_buff *skb = rx->skb;
1227 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
1228 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
1229 	int i;
1230 
1231 	if (!sta)
1232 		return RX_CONTINUE;
1233 
1234 	/*
1235 	 * Update last_rx only for IBSS packets which are for the current
1236 	 * BSSID and for station already AUTHORIZED to avoid keeping the
1237 	 * current IBSS network alive in cases where other STAs start
1238 	 * using different BSSID. This will also give the station another
1239 	 * chance to restart the authentication/authorization in case
1240 	 * something went wrong the first time.
1241 	 */
1242 	if (rx->sdata->vif.type == NL80211_IFTYPE_ADHOC) {
1243 		u8 *bssid = ieee80211_get_bssid(hdr, rx->skb->len,
1244 						NL80211_IFTYPE_ADHOC);
1245 		if (ether_addr_equal(bssid, rx->sdata->u.ibss.bssid) &&
1246 		    test_sta_flag(sta, WLAN_STA_AUTHORIZED)) {
1247 			sta->last_rx = jiffies;
1248 			if (ieee80211_is_data(hdr->frame_control)) {
1249 				sta->last_rx_rate_idx = status->rate_idx;
1250 				sta->last_rx_rate_flag = status->flag;
1251 				sta->last_rx_rate_vht_nss = status->vht_nss;
1252 			}
1253 		}
1254 	} else if (!is_multicast_ether_addr(hdr->addr1)) {
1255 		/*
1256 		 * Mesh beacons will update last_rx when if they are found to
1257 		 * match the current local configuration when processed.
1258 		 */
1259 		sta->last_rx = jiffies;
1260 		if (ieee80211_is_data(hdr->frame_control)) {
1261 			sta->last_rx_rate_idx = status->rate_idx;
1262 			sta->last_rx_rate_flag = status->flag;
1263 			sta->last_rx_rate_vht_nss = status->vht_nss;
1264 		}
1265 	}
1266 
1267 	if (!(status->rx_flags & IEEE80211_RX_RA_MATCH))
1268 		return RX_CONTINUE;
1269 
1270 	if (rx->sdata->vif.type == NL80211_IFTYPE_STATION)
1271 		ieee80211_sta_rx_notify(rx->sdata, hdr);
1272 
1273 	sta->rx_fragments++;
1274 	sta->rx_bytes += rx->skb->len;
1275 	if (!(status->flag & RX_FLAG_NO_SIGNAL_VAL)) {
1276 		sta->last_signal = status->signal;
1277 		ewma_add(&sta->avg_signal, -status->signal);
1278 	}
1279 
1280 	if (status->chains) {
1281 		sta->chains = status->chains;
1282 		for (i = 0; i < ARRAY_SIZE(status->chain_signal); i++) {
1283 			int signal = status->chain_signal[i];
1284 
1285 			if (!(status->chains & BIT(i)))
1286 				continue;
1287 
1288 			sta->chain_signal_last[i] = signal;
1289 			ewma_add(&sta->chain_signal_avg[i], -signal);
1290 		}
1291 	}
1292 
1293 	/*
1294 	 * Change STA power saving mode only at the end of a frame
1295 	 * exchange sequence.
1296 	 */
1297 	if (!(sta->local->hw.flags & IEEE80211_HW_AP_LINK_PS) &&
1298 	    !ieee80211_has_morefrags(hdr->frame_control) &&
1299 	    !(status->rx_flags & IEEE80211_RX_DEFERRED_RELEASE) &&
1300 	    (rx->sdata->vif.type == NL80211_IFTYPE_AP ||
1301 	     rx->sdata->vif.type == NL80211_IFTYPE_AP_VLAN)) {
1302 		if (test_sta_flag(sta, WLAN_STA_PS_STA)) {
1303 			/*
1304 			 * Ignore doze->wake transitions that are
1305 			 * indicated by non-data frames, the standard
1306 			 * is unclear here, but for example going to
1307 			 * PS mode and then scanning would cause a
1308 			 * doze->wake transition for the probe request,
1309 			 * and that is clearly undesirable.
1310 			 */
1311 			if (ieee80211_is_data(hdr->frame_control) &&
1312 			    !ieee80211_has_pm(hdr->frame_control))
1313 				sta_ps_end(sta);
1314 		} else {
1315 			if (ieee80211_has_pm(hdr->frame_control))
1316 				sta_ps_start(sta);
1317 		}
1318 	}
1319 
1320 	/* mesh power save support */
1321 	if (ieee80211_vif_is_mesh(&rx->sdata->vif))
1322 		ieee80211_mps_rx_h_sta_process(sta, hdr);
1323 
1324 	/*
1325 	 * Drop (qos-)data::nullfunc frames silently, since they
1326 	 * are used only to control station power saving mode.
1327 	 */
1328 	if (ieee80211_is_nullfunc(hdr->frame_control) ||
1329 	    ieee80211_is_qos_nullfunc(hdr->frame_control)) {
1330 		I802_DEBUG_INC(rx->local->rx_handlers_drop_nullfunc);
1331 
1332 		/*
1333 		 * If we receive a 4-addr nullfunc frame from a STA
1334 		 * that was not moved to a 4-addr STA vlan yet send
1335 		 * the event to userspace and for older hostapd drop
1336 		 * the frame to the monitor interface.
1337 		 */
1338 		if (ieee80211_has_a4(hdr->frame_control) &&
1339 		    (rx->sdata->vif.type == NL80211_IFTYPE_AP ||
1340 		     (rx->sdata->vif.type == NL80211_IFTYPE_AP_VLAN &&
1341 		      !rx->sdata->u.vlan.sta))) {
1342 			if (!test_and_set_sta_flag(sta, WLAN_STA_4ADDR_EVENT))
1343 				cfg80211_rx_unexpected_4addr_frame(
1344 					rx->sdata->dev, sta->sta.addr,
1345 					GFP_ATOMIC);
1346 			return RX_DROP_MONITOR;
1347 		}
1348 		/*
1349 		 * Update counter and free packet here to avoid
1350 		 * counting this as a dropped packed.
1351 		 */
1352 		sta->rx_packets++;
1353 		dev_kfree_skb(rx->skb);
1354 		return RX_QUEUED;
1355 	}
1356 
1357 	return RX_CONTINUE;
1358 } /* ieee80211_rx_h_sta_process */
1359 
1360 static ieee80211_rx_result debug_noinline
1361 ieee80211_rx_h_decrypt(struct ieee80211_rx_data *rx)
1362 {
1363 	struct sk_buff *skb = rx->skb;
1364 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
1365 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
1366 	int keyidx;
1367 	int hdrlen;
1368 	ieee80211_rx_result result = RX_DROP_UNUSABLE;
1369 	struct ieee80211_key *sta_ptk = NULL;
1370 	int mmie_keyidx = -1;
1371 	__le16 fc;
1372 
1373 	/*
1374 	 * Key selection 101
1375 	 *
1376 	 * There are four types of keys:
1377 	 *  - GTK (group keys)
1378 	 *  - IGTK (group keys for management frames)
1379 	 *  - PTK (pairwise keys)
1380 	 *  - STK (station-to-station pairwise keys)
1381 	 *
1382 	 * When selecting a key, we have to distinguish between multicast
1383 	 * (including broadcast) and unicast frames, the latter can only
1384 	 * use PTKs and STKs while the former always use GTKs and IGTKs.
1385 	 * Unless, of course, actual WEP keys ("pre-RSNA") are used, then
1386 	 * unicast frames can also use key indices like GTKs. Hence, if we
1387 	 * don't have a PTK/STK we check the key index for a WEP key.
1388 	 *
1389 	 * Note that in a regular BSS, multicast frames are sent by the
1390 	 * AP only, associated stations unicast the frame to the AP first
1391 	 * which then multicasts it on their behalf.
1392 	 *
1393 	 * There is also a slight problem in IBSS mode: GTKs are negotiated
1394 	 * with each station, that is something we don't currently handle.
1395 	 * The spec seems to expect that one negotiates the same key with
1396 	 * every station but there's no such requirement; VLANs could be
1397 	 * possible.
1398 	 */
1399 
1400 	/*
1401 	 * No point in finding a key and decrypting if the frame is neither
1402 	 * addressed to us nor a multicast frame.
1403 	 */
1404 	if (!(status->rx_flags & IEEE80211_RX_RA_MATCH))
1405 		return RX_CONTINUE;
1406 
1407 	/* start without a key */
1408 	rx->key = NULL;
1409 
1410 	if (rx->sta)
1411 		sta_ptk = rcu_dereference(rx->sta->ptk);
1412 
1413 	fc = hdr->frame_control;
1414 
1415 	if (!ieee80211_has_protected(fc))
1416 		mmie_keyidx = ieee80211_get_mmie_keyidx(rx->skb);
1417 
1418 	if (!is_multicast_ether_addr(hdr->addr1) && sta_ptk) {
1419 		rx->key = sta_ptk;
1420 		if ((status->flag & RX_FLAG_DECRYPTED) &&
1421 		    (status->flag & RX_FLAG_IV_STRIPPED))
1422 			return RX_CONTINUE;
1423 		/* Skip decryption if the frame is not protected. */
1424 		if (!ieee80211_has_protected(fc))
1425 			return RX_CONTINUE;
1426 	} else if (mmie_keyidx >= 0) {
1427 		/* Broadcast/multicast robust management frame / BIP */
1428 		if ((status->flag & RX_FLAG_DECRYPTED) &&
1429 		    (status->flag & RX_FLAG_IV_STRIPPED))
1430 			return RX_CONTINUE;
1431 
1432 		if (mmie_keyidx < NUM_DEFAULT_KEYS ||
1433 		    mmie_keyidx >= NUM_DEFAULT_KEYS + NUM_DEFAULT_MGMT_KEYS)
1434 			return RX_DROP_MONITOR; /* unexpected BIP keyidx */
1435 		if (rx->sta)
1436 			rx->key = rcu_dereference(rx->sta->gtk[mmie_keyidx]);
1437 		if (!rx->key)
1438 			rx->key = rcu_dereference(rx->sdata->keys[mmie_keyidx]);
1439 	} else if (!ieee80211_has_protected(fc)) {
1440 		/*
1441 		 * The frame was not protected, so skip decryption. However, we
1442 		 * need to set rx->key if there is a key that could have been
1443 		 * used so that the frame may be dropped if encryption would
1444 		 * have been expected.
1445 		 */
1446 		struct ieee80211_key *key = NULL;
1447 		struct ieee80211_sub_if_data *sdata = rx->sdata;
1448 		int i;
1449 
1450 		if (ieee80211_is_mgmt(fc) &&
1451 		    is_multicast_ether_addr(hdr->addr1) &&
1452 		    (key = rcu_dereference(rx->sdata->default_mgmt_key)))
1453 			rx->key = key;
1454 		else {
1455 			if (rx->sta) {
1456 				for (i = 0; i < NUM_DEFAULT_KEYS; i++) {
1457 					key = rcu_dereference(rx->sta->gtk[i]);
1458 					if (key)
1459 						break;
1460 				}
1461 			}
1462 			if (!key) {
1463 				for (i = 0; i < NUM_DEFAULT_KEYS; i++) {
1464 					key = rcu_dereference(sdata->keys[i]);
1465 					if (key)
1466 						break;
1467 				}
1468 			}
1469 			if (key)
1470 				rx->key = key;
1471 		}
1472 		return RX_CONTINUE;
1473 	} else {
1474 		u8 keyid;
1475 		/*
1476 		 * The device doesn't give us the IV so we won't be
1477 		 * able to look up the key. That's ok though, we
1478 		 * don't need to decrypt the frame, we just won't
1479 		 * be able to keep statistics accurate.
1480 		 * Except for key threshold notifications, should
1481 		 * we somehow allow the driver to tell us which key
1482 		 * the hardware used if this flag is set?
1483 		 */
1484 		if ((status->flag & RX_FLAG_DECRYPTED) &&
1485 		    (status->flag & RX_FLAG_IV_STRIPPED))
1486 			return RX_CONTINUE;
1487 
1488 		hdrlen = ieee80211_hdrlen(fc);
1489 
1490 		if (rx->skb->len < 8 + hdrlen)
1491 			return RX_DROP_UNUSABLE; /* TODO: count this? */
1492 
1493 		/*
1494 		 * no need to call ieee80211_wep_get_keyidx,
1495 		 * it verifies a bunch of things we've done already
1496 		 */
1497 		skb_copy_bits(rx->skb, hdrlen + 3, &keyid, 1);
1498 		keyidx = keyid >> 6;
1499 
1500 		/* check per-station GTK first, if multicast packet */
1501 		if (is_multicast_ether_addr(hdr->addr1) && rx->sta)
1502 			rx->key = rcu_dereference(rx->sta->gtk[keyidx]);
1503 
1504 		/* if not found, try default key */
1505 		if (!rx->key) {
1506 			rx->key = rcu_dereference(rx->sdata->keys[keyidx]);
1507 
1508 			/*
1509 			 * RSNA-protected unicast frames should always be
1510 			 * sent with pairwise or station-to-station keys,
1511 			 * but for WEP we allow using a key index as well.
1512 			 */
1513 			if (rx->key &&
1514 			    rx->key->conf.cipher != WLAN_CIPHER_SUITE_WEP40 &&
1515 			    rx->key->conf.cipher != WLAN_CIPHER_SUITE_WEP104 &&
1516 			    !is_multicast_ether_addr(hdr->addr1))
1517 				rx->key = NULL;
1518 		}
1519 	}
1520 
1521 	if (rx->key) {
1522 		if (unlikely(rx->key->flags & KEY_FLAG_TAINTED))
1523 			return RX_DROP_MONITOR;
1524 
1525 		rx->key->tx_rx_count++;
1526 		/* TODO: add threshold stuff again */
1527 	} else {
1528 		return RX_DROP_MONITOR;
1529 	}
1530 
1531 	switch (rx->key->conf.cipher) {
1532 	case WLAN_CIPHER_SUITE_WEP40:
1533 	case WLAN_CIPHER_SUITE_WEP104:
1534 		result = ieee80211_crypto_wep_decrypt(rx);
1535 		break;
1536 	case WLAN_CIPHER_SUITE_TKIP:
1537 		result = ieee80211_crypto_tkip_decrypt(rx);
1538 		break;
1539 	case WLAN_CIPHER_SUITE_CCMP:
1540 		result = ieee80211_crypto_ccmp_decrypt(rx);
1541 		break;
1542 	case WLAN_CIPHER_SUITE_AES_CMAC:
1543 		result = ieee80211_crypto_aes_cmac_decrypt(rx);
1544 		break;
1545 	default:
1546 		/*
1547 		 * We can reach here only with HW-only algorithms
1548 		 * but why didn't it decrypt the frame?!
1549 		 */
1550 		return RX_DROP_UNUSABLE;
1551 	}
1552 
1553 	/* the hdr variable is invalid after the decrypt handlers */
1554 
1555 	/* either the frame has been decrypted or will be dropped */
1556 	status->flag |= RX_FLAG_DECRYPTED;
1557 
1558 	return result;
1559 }
1560 
1561 static inline struct ieee80211_fragment_entry *
1562 ieee80211_reassemble_add(struct ieee80211_sub_if_data *sdata,
1563 			 unsigned int frag, unsigned int seq, int rx_queue,
1564 			 struct sk_buff **skb)
1565 {
1566 	struct ieee80211_fragment_entry *entry;
1567 
1568 	entry = &sdata->fragments[sdata->fragment_next++];
1569 	if (sdata->fragment_next >= IEEE80211_FRAGMENT_MAX)
1570 		sdata->fragment_next = 0;
1571 
1572 	if (!skb_queue_empty(&entry->skb_list))
1573 		__skb_queue_purge(&entry->skb_list);
1574 
1575 	__skb_queue_tail(&entry->skb_list, *skb); /* no need for locking */
1576 	*skb = NULL;
1577 	entry->first_frag_time = jiffies;
1578 	entry->seq = seq;
1579 	entry->rx_queue = rx_queue;
1580 	entry->last_frag = frag;
1581 	entry->ccmp = 0;
1582 	entry->extra_len = 0;
1583 
1584 	return entry;
1585 }
1586 
1587 static inline struct ieee80211_fragment_entry *
1588 ieee80211_reassemble_find(struct ieee80211_sub_if_data *sdata,
1589 			  unsigned int frag, unsigned int seq,
1590 			  int rx_queue, struct ieee80211_hdr *hdr)
1591 {
1592 	struct ieee80211_fragment_entry *entry;
1593 	int i, idx;
1594 
1595 	idx = sdata->fragment_next;
1596 	for (i = 0; i < IEEE80211_FRAGMENT_MAX; i++) {
1597 		struct ieee80211_hdr *f_hdr;
1598 
1599 		idx--;
1600 		if (idx < 0)
1601 			idx = IEEE80211_FRAGMENT_MAX - 1;
1602 
1603 		entry = &sdata->fragments[idx];
1604 		if (skb_queue_empty(&entry->skb_list) || entry->seq != seq ||
1605 		    entry->rx_queue != rx_queue ||
1606 		    entry->last_frag + 1 != frag)
1607 			continue;
1608 
1609 		f_hdr = (struct ieee80211_hdr *)entry->skb_list.next->data;
1610 
1611 		/*
1612 		 * Check ftype and addresses are equal, else check next fragment
1613 		 */
1614 		if (((hdr->frame_control ^ f_hdr->frame_control) &
1615 		     cpu_to_le16(IEEE80211_FCTL_FTYPE)) ||
1616 		    !ether_addr_equal(hdr->addr1, f_hdr->addr1) ||
1617 		    !ether_addr_equal(hdr->addr2, f_hdr->addr2))
1618 			continue;
1619 
1620 		if (time_after(jiffies, entry->first_frag_time + 2 * HZ)) {
1621 			__skb_queue_purge(&entry->skb_list);
1622 			continue;
1623 		}
1624 		return entry;
1625 	}
1626 
1627 	return NULL;
1628 }
1629 
1630 static ieee80211_rx_result debug_noinline
1631 ieee80211_rx_h_defragment(struct ieee80211_rx_data *rx)
1632 {
1633 	struct ieee80211_hdr *hdr;
1634 	u16 sc;
1635 	__le16 fc;
1636 	unsigned int frag, seq;
1637 	struct ieee80211_fragment_entry *entry;
1638 	struct sk_buff *skb;
1639 	struct ieee80211_rx_status *status;
1640 
1641 	hdr = (struct ieee80211_hdr *)rx->skb->data;
1642 	fc = hdr->frame_control;
1643 
1644 	if (ieee80211_is_ctl(fc))
1645 		return RX_CONTINUE;
1646 
1647 	sc = le16_to_cpu(hdr->seq_ctrl);
1648 	frag = sc & IEEE80211_SCTL_FRAG;
1649 
1650 	if (likely((!ieee80211_has_morefrags(fc) && frag == 0) ||
1651 		   is_multicast_ether_addr(hdr->addr1))) {
1652 		/* not fragmented */
1653 		goto out;
1654 	}
1655 	I802_DEBUG_INC(rx->local->rx_handlers_fragments);
1656 
1657 	if (skb_linearize(rx->skb))
1658 		return RX_DROP_UNUSABLE;
1659 
1660 	/*
1661 	 *  skb_linearize() might change the skb->data and
1662 	 *  previously cached variables (in this case, hdr) need to
1663 	 *  be refreshed with the new data.
1664 	 */
1665 	hdr = (struct ieee80211_hdr *)rx->skb->data;
1666 	seq = (sc & IEEE80211_SCTL_SEQ) >> 4;
1667 
1668 	if (frag == 0) {
1669 		/* This is the first fragment of a new frame. */
1670 		entry = ieee80211_reassemble_add(rx->sdata, frag, seq,
1671 						 rx->seqno_idx, &(rx->skb));
1672 		if (rx->key && rx->key->conf.cipher == WLAN_CIPHER_SUITE_CCMP &&
1673 		    ieee80211_has_protected(fc)) {
1674 			int queue = rx->security_idx;
1675 			/* Store CCMP PN so that we can verify that the next
1676 			 * fragment has a sequential PN value. */
1677 			entry->ccmp = 1;
1678 			memcpy(entry->last_pn,
1679 			       rx->key->u.ccmp.rx_pn[queue],
1680 			       IEEE80211_CCMP_PN_LEN);
1681 		}
1682 		return RX_QUEUED;
1683 	}
1684 
1685 	/* This is a fragment for a frame that should already be pending in
1686 	 * fragment cache. Add this fragment to the end of the pending entry.
1687 	 */
1688 	entry = ieee80211_reassemble_find(rx->sdata, frag, seq,
1689 					  rx->seqno_idx, hdr);
1690 	if (!entry) {
1691 		I802_DEBUG_INC(rx->local->rx_handlers_drop_defrag);
1692 		return RX_DROP_MONITOR;
1693 	}
1694 
1695 	/* Verify that MPDUs within one MSDU have sequential PN values.
1696 	 * (IEEE 802.11i, 8.3.3.4.5) */
1697 	if (entry->ccmp) {
1698 		int i;
1699 		u8 pn[IEEE80211_CCMP_PN_LEN], *rpn;
1700 		int queue;
1701 		if (!rx->key || rx->key->conf.cipher != WLAN_CIPHER_SUITE_CCMP)
1702 			return RX_DROP_UNUSABLE;
1703 		memcpy(pn, entry->last_pn, IEEE80211_CCMP_PN_LEN);
1704 		for (i = IEEE80211_CCMP_PN_LEN - 1; i >= 0; i--) {
1705 			pn[i]++;
1706 			if (pn[i])
1707 				break;
1708 		}
1709 		queue = rx->security_idx;
1710 		rpn = rx->key->u.ccmp.rx_pn[queue];
1711 		if (memcmp(pn, rpn, IEEE80211_CCMP_PN_LEN))
1712 			return RX_DROP_UNUSABLE;
1713 		memcpy(entry->last_pn, pn, IEEE80211_CCMP_PN_LEN);
1714 	}
1715 
1716 	skb_pull(rx->skb, ieee80211_hdrlen(fc));
1717 	__skb_queue_tail(&entry->skb_list, rx->skb);
1718 	entry->last_frag = frag;
1719 	entry->extra_len += rx->skb->len;
1720 	if (ieee80211_has_morefrags(fc)) {
1721 		rx->skb = NULL;
1722 		return RX_QUEUED;
1723 	}
1724 
1725 	rx->skb = __skb_dequeue(&entry->skb_list);
1726 	if (skb_tailroom(rx->skb) < entry->extra_len) {
1727 		I802_DEBUG_INC(rx->local->rx_expand_skb_head2);
1728 		if (unlikely(pskb_expand_head(rx->skb, 0, entry->extra_len,
1729 					      GFP_ATOMIC))) {
1730 			I802_DEBUG_INC(rx->local->rx_handlers_drop_defrag);
1731 			__skb_queue_purge(&entry->skb_list);
1732 			return RX_DROP_UNUSABLE;
1733 		}
1734 	}
1735 	while ((skb = __skb_dequeue(&entry->skb_list))) {
1736 		memcpy(skb_put(rx->skb, skb->len), skb->data, skb->len);
1737 		dev_kfree_skb(skb);
1738 	}
1739 
1740 	/* Complete frame has been reassembled - process it now */
1741 	status = IEEE80211_SKB_RXCB(rx->skb);
1742 	status->rx_flags |= IEEE80211_RX_FRAGMENTED;
1743 
1744  out:
1745 	if (rx->sta)
1746 		rx->sta->rx_packets++;
1747 	if (is_multicast_ether_addr(hdr->addr1))
1748 		rx->local->dot11MulticastReceivedFrameCount++;
1749 	else
1750 		ieee80211_led_rx(rx->local);
1751 	return RX_CONTINUE;
1752 }
1753 
1754 static int ieee80211_802_1x_port_control(struct ieee80211_rx_data *rx)
1755 {
1756 	if (unlikely(!rx->sta || !test_sta_flag(rx->sta, WLAN_STA_AUTHORIZED)))
1757 		return -EACCES;
1758 
1759 	return 0;
1760 }
1761 
1762 static int ieee80211_drop_unencrypted(struct ieee80211_rx_data *rx, __le16 fc)
1763 {
1764 	struct sk_buff *skb = rx->skb;
1765 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
1766 
1767 	/*
1768 	 * Pass through unencrypted frames if the hardware has
1769 	 * decrypted them already.
1770 	 */
1771 	if (status->flag & RX_FLAG_DECRYPTED)
1772 		return 0;
1773 
1774 	/* Drop unencrypted frames if key is set. */
1775 	if (unlikely(!ieee80211_has_protected(fc) &&
1776 		     !ieee80211_is_nullfunc(fc) &&
1777 		     ieee80211_is_data(fc) &&
1778 		     (rx->key || rx->sdata->drop_unencrypted)))
1779 		return -EACCES;
1780 
1781 	return 0;
1782 }
1783 
1784 static int ieee80211_drop_unencrypted_mgmt(struct ieee80211_rx_data *rx)
1785 {
1786 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
1787 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
1788 	__le16 fc = hdr->frame_control;
1789 
1790 	/*
1791 	 * Pass through unencrypted frames if the hardware has
1792 	 * decrypted them already.
1793 	 */
1794 	if (status->flag & RX_FLAG_DECRYPTED)
1795 		return 0;
1796 
1797 	if (rx->sta && test_sta_flag(rx->sta, WLAN_STA_MFP)) {
1798 		if (unlikely(!ieee80211_has_protected(fc) &&
1799 			     ieee80211_is_unicast_robust_mgmt_frame(rx->skb) &&
1800 			     rx->key)) {
1801 			if (ieee80211_is_deauth(fc) ||
1802 			    ieee80211_is_disassoc(fc))
1803 				cfg80211_rx_unprot_mlme_mgmt(rx->sdata->dev,
1804 							     rx->skb->data,
1805 							     rx->skb->len);
1806 			return -EACCES;
1807 		}
1808 		/* BIP does not use Protected field, so need to check MMIE */
1809 		if (unlikely(ieee80211_is_multicast_robust_mgmt_frame(rx->skb) &&
1810 			     ieee80211_get_mmie_keyidx(rx->skb) < 0)) {
1811 			if (ieee80211_is_deauth(fc) ||
1812 			    ieee80211_is_disassoc(fc))
1813 				cfg80211_rx_unprot_mlme_mgmt(rx->sdata->dev,
1814 							     rx->skb->data,
1815 							     rx->skb->len);
1816 			return -EACCES;
1817 		}
1818 		/*
1819 		 * When using MFP, Action frames are not allowed prior to
1820 		 * having configured keys.
1821 		 */
1822 		if (unlikely(ieee80211_is_action(fc) && !rx->key &&
1823 			     ieee80211_is_robust_mgmt_frame(
1824 				     (struct ieee80211_hdr *) rx->skb->data)))
1825 			return -EACCES;
1826 	}
1827 
1828 	return 0;
1829 }
1830 
1831 static int
1832 __ieee80211_data_to_8023(struct ieee80211_rx_data *rx, bool *port_control)
1833 {
1834 	struct ieee80211_sub_if_data *sdata = rx->sdata;
1835 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
1836 	bool check_port_control = false;
1837 	struct ethhdr *ehdr;
1838 	int ret;
1839 
1840 	*port_control = false;
1841 	if (ieee80211_has_a4(hdr->frame_control) &&
1842 	    sdata->vif.type == NL80211_IFTYPE_AP_VLAN && !sdata->u.vlan.sta)
1843 		return -1;
1844 
1845 	if (sdata->vif.type == NL80211_IFTYPE_STATION &&
1846 	    !!sdata->u.mgd.use_4addr != !!ieee80211_has_a4(hdr->frame_control)) {
1847 
1848 		if (!sdata->u.mgd.use_4addr)
1849 			return -1;
1850 		else
1851 			check_port_control = true;
1852 	}
1853 
1854 	if (is_multicast_ether_addr(hdr->addr1) &&
1855 	    sdata->vif.type == NL80211_IFTYPE_AP_VLAN && sdata->u.vlan.sta)
1856 		return -1;
1857 
1858 	ret = ieee80211_data_to_8023(rx->skb, sdata->vif.addr, sdata->vif.type);
1859 	if (ret < 0)
1860 		return ret;
1861 
1862 	ehdr = (struct ethhdr *) rx->skb->data;
1863 	if (ehdr->h_proto == rx->sdata->control_port_protocol)
1864 		*port_control = true;
1865 	else if (check_port_control)
1866 		return -1;
1867 
1868 	return 0;
1869 }
1870 
1871 /*
1872  * requires that rx->skb is a frame with ethernet header
1873  */
1874 static bool ieee80211_frame_allowed(struct ieee80211_rx_data *rx, __le16 fc)
1875 {
1876 	static const u8 pae_group_addr[ETH_ALEN] __aligned(2)
1877 		= { 0x01, 0x80, 0xC2, 0x00, 0x00, 0x03 };
1878 	struct ethhdr *ehdr = (struct ethhdr *) rx->skb->data;
1879 
1880 	/*
1881 	 * Allow EAPOL frames to us/the PAE group address regardless
1882 	 * of whether the frame was encrypted or not.
1883 	 */
1884 	if (ehdr->h_proto == rx->sdata->control_port_protocol &&
1885 	    (ether_addr_equal(ehdr->h_dest, rx->sdata->vif.addr) ||
1886 	     ether_addr_equal(ehdr->h_dest, pae_group_addr)))
1887 		return true;
1888 
1889 	if (ieee80211_802_1x_port_control(rx) ||
1890 	    ieee80211_drop_unencrypted(rx, fc))
1891 		return false;
1892 
1893 	return true;
1894 }
1895 
1896 /*
1897  * requires that rx->skb is a frame with ethernet header
1898  */
1899 static void
1900 ieee80211_deliver_skb(struct ieee80211_rx_data *rx)
1901 {
1902 	struct ieee80211_sub_if_data *sdata = rx->sdata;
1903 	struct net_device *dev = sdata->dev;
1904 	struct sk_buff *skb, *xmit_skb;
1905 	struct ethhdr *ehdr = (struct ethhdr *) rx->skb->data;
1906 	struct sta_info *dsta;
1907 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
1908 
1909 	skb = rx->skb;
1910 	xmit_skb = NULL;
1911 
1912 	if ((sdata->vif.type == NL80211_IFTYPE_AP ||
1913 	     sdata->vif.type == NL80211_IFTYPE_AP_VLAN) &&
1914 	    !(sdata->flags & IEEE80211_SDATA_DONT_BRIDGE_PACKETS) &&
1915 	    (status->rx_flags & IEEE80211_RX_RA_MATCH) &&
1916 	    (sdata->vif.type != NL80211_IFTYPE_AP_VLAN || !sdata->u.vlan.sta)) {
1917 		if (is_multicast_ether_addr(ehdr->h_dest)) {
1918 			/*
1919 			 * send multicast frames both to higher layers in
1920 			 * local net stack and back to the wireless medium
1921 			 */
1922 			xmit_skb = skb_copy(skb, GFP_ATOMIC);
1923 			if (!xmit_skb)
1924 				net_info_ratelimited("%s: failed to clone multicast frame\n",
1925 						    dev->name);
1926 		} else {
1927 			dsta = sta_info_get(sdata, skb->data);
1928 			if (dsta) {
1929 				/*
1930 				 * The destination station is associated to
1931 				 * this AP (in this VLAN), so send the frame
1932 				 * directly to it and do not pass it to local
1933 				 * net stack.
1934 				 */
1935 				xmit_skb = skb;
1936 				skb = NULL;
1937 			}
1938 		}
1939 	}
1940 
1941 	if (skb) {
1942 		int align __maybe_unused;
1943 
1944 #ifndef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
1945 		/*
1946 		 * 'align' will only take the values 0 or 2 here
1947 		 * since all frames are required to be aligned
1948 		 * to 2-byte boundaries when being passed to
1949 		 * mac80211; the code here works just as well if
1950 		 * that isn't true, but mac80211 assumes it can
1951 		 * access fields as 2-byte aligned (e.g. for
1952 		 * compare_ether_addr)
1953 		 */
1954 		align = ((unsigned long)(skb->data + sizeof(struct ethhdr))) & 3;
1955 		if (align) {
1956 			if (WARN_ON(skb_headroom(skb) < 3)) {
1957 				dev_kfree_skb(skb);
1958 				skb = NULL;
1959 			} else {
1960 				u8 *data = skb->data;
1961 				size_t len = skb_headlen(skb);
1962 				skb->data -= align;
1963 				memmove(skb->data, data, len);
1964 				skb_set_tail_pointer(skb, len);
1965 			}
1966 		}
1967 #endif
1968 
1969 		if (skb) {
1970 			/* deliver to local stack */
1971 			skb->protocol = eth_type_trans(skb, dev);
1972 			memset(skb->cb, 0, sizeof(skb->cb));
1973 			netif_receive_skb(skb);
1974 		}
1975 	}
1976 
1977 	if (xmit_skb) {
1978 		/*
1979 		 * Send to wireless media and increase priority by 256 to
1980 		 * keep the received priority instead of reclassifying
1981 		 * the frame (see cfg80211_classify8021d).
1982 		 */
1983 		xmit_skb->priority += 256;
1984 		xmit_skb->protocol = htons(ETH_P_802_3);
1985 		skb_reset_network_header(xmit_skb);
1986 		skb_reset_mac_header(xmit_skb);
1987 		dev_queue_xmit(xmit_skb);
1988 	}
1989 }
1990 
1991 static ieee80211_rx_result debug_noinline
1992 ieee80211_rx_h_amsdu(struct ieee80211_rx_data *rx)
1993 {
1994 	struct net_device *dev = rx->sdata->dev;
1995 	struct sk_buff *skb = rx->skb;
1996 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
1997 	__le16 fc = hdr->frame_control;
1998 	struct sk_buff_head frame_list;
1999 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
2000 
2001 	if (unlikely(!ieee80211_is_data(fc)))
2002 		return RX_CONTINUE;
2003 
2004 	if (unlikely(!ieee80211_is_data_present(fc)))
2005 		return RX_DROP_MONITOR;
2006 
2007 	if (!(status->rx_flags & IEEE80211_RX_AMSDU))
2008 		return RX_CONTINUE;
2009 
2010 	if (ieee80211_has_a4(hdr->frame_control) &&
2011 	    rx->sdata->vif.type == NL80211_IFTYPE_AP_VLAN &&
2012 	    !rx->sdata->u.vlan.sta)
2013 		return RX_DROP_UNUSABLE;
2014 
2015 	if (is_multicast_ether_addr(hdr->addr1) &&
2016 	    ((rx->sdata->vif.type == NL80211_IFTYPE_AP_VLAN &&
2017 	      rx->sdata->u.vlan.sta) ||
2018 	     (rx->sdata->vif.type == NL80211_IFTYPE_STATION &&
2019 	      rx->sdata->u.mgd.use_4addr)))
2020 		return RX_DROP_UNUSABLE;
2021 
2022 	skb->dev = dev;
2023 	__skb_queue_head_init(&frame_list);
2024 
2025 	if (skb_linearize(skb))
2026 		return RX_DROP_UNUSABLE;
2027 
2028 	ieee80211_amsdu_to_8023s(skb, &frame_list, dev->dev_addr,
2029 				 rx->sdata->vif.type,
2030 				 rx->local->hw.extra_tx_headroom, true);
2031 
2032 	while (!skb_queue_empty(&frame_list)) {
2033 		rx->skb = __skb_dequeue(&frame_list);
2034 
2035 		if (!ieee80211_frame_allowed(rx, fc)) {
2036 			dev_kfree_skb(rx->skb);
2037 			continue;
2038 		}
2039 		dev->stats.rx_packets++;
2040 		dev->stats.rx_bytes += rx->skb->len;
2041 
2042 		ieee80211_deliver_skb(rx);
2043 	}
2044 
2045 	return RX_QUEUED;
2046 }
2047 
2048 #ifdef CONFIG_MAC80211_MESH
2049 static ieee80211_rx_result
2050 ieee80211_rx_h_mesh_fwding(struct ieee80211_rx_data *rx)
2051 {
2052 	struct ieee80211_hdr *fwd_hdr, *hdr;
2053 	struct ieee80211_tx_info *info;
2054 	struct ieee80211s_hdr *mesh_hdr;
2055 	struct sk_buff *skb = rx->skb, *fwd_skb;
2056 	struct ieee80211_local *local = rx->local;
2057 	struct ieee80211_sub_if_data *sdata = rx->sdata;
2058 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
2059 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
2060 	__le16 reason = cpu_to_le16(WLAN_REASON_MESH_PATH_NOFORWARD);
2061 	u16 q, hdrlen;
2062 
2063 	hdr = (struct ieee80211_hdr *) skb->data;
2064 	hdrlen = ieee80211_hdrlen(hdr->frame_control);
2065 
2066 	/* make sure fixed part of mesh header is there, also checks skb len */
2067 	if (!pskb_may_pull(rx->skb, hdrlen + 6))
2068 		return RX_DROP_MONITOR;
2069 
2070 	mesh_hdr = (struct ieee80211s_hdr *) (skb->data + hdrlen);
2071 
2072 	/* make sure full mesh header is there, also checks skb len */
2073 	if (!pskb_may_pull(rx->skb,
2074 			   hdrlen + ieee80211_get_mesh_hdrlen(mesh_hdr)))
2075 		return RX_DROP_MONITOR;
2076 
2077 	/* reload pointers */
2078 	hdr = (struct ieee80211_hdr *) skb->data;
2079 	mesh_hdr = (struct ieee80211s_hdr *) (skb->data + hdrlen);
2080 
2081 	/* frame is in RMC, don't forward */
2082 	if (ieee80211_is_data(hdr->frame_control) &&
2083 	    is_multicast_ether_addr(hdr->addr1) &&
2084 	    mesh_rmc_check(rx->sdata, hdr->addr3, mesh_hdr))
2085 		return RX_DROP_MONITOR;
2086 
2087 	if (!ieee80211_is_data(hdr->frame_control) ||
2088 	    !(status->rx_flags & IEEE80211_RX_RA_MATCH))
2089 		return RX_CONTINUE;
2090 
2091 	if (!mesh_hdr->ttl)
2092 		return RX_DROP_MONITOR;
2093 
2094 	if (mesh_hdr->flags & MESH_FLAGS_AE) {
2095 		struct mesh_path *mppath;
2096 		char *proxied_addr;
2097 		char *mpp_addr;
2098 
2099 		if (is_multicast_ether_addr(hdr->addr1)) {
2100 			mpp_addr = hdr->addr3;
2101 			proxied_addr = mesh_hdr->eaddr1;
2102 		} else if (mesh_hdr->flags & MESH_FLAGS_AE_A5_A6) {
2103 			/* has_a4 already checked in ieee80211_rx_mesh_check */
2104 			mpp_addr = hdr->addr4;
2105 			proxied_addr = mesh_hdr->eaddr2;
2106 		} else {
2107 			return RX_DROP_MONITOR;
2108 		}
2109 
2110 		rcu_read_lock();
2111 		mppath = mpp_path_lookup(sdata, proxied_addr);
2112 		if (!mppath) {
2113 			mpp_path_add(sdata, proxied_addr, mpp_addr);
2114 		} else {
2115 			spin_lock_bh(&mppath->state_lock);
2116 			if (!ether_addr_equal(mppath->mpp, mpp_addr))
2117 				memcpy(mppath->mpp, mpp_addr, ETH_ALEN);
2118 			spin_unlock_bh(&mppath->state_lock);
2119 		}
2120 		rcu_read_unlock();
2121 	}
2122 
2123 	/* Frame has reached destination.  Don't forward */
2124 	if (!is_multicast_ether_addr(hdr->addr1) &&
2125 	    ether_addr_equal(sdata->vif.addr, hdr->addr3))
2126 		return RX_CONTINUE;
2127 
2128 	q = ieee80211_select_queue_80211(sdata, skb, hdr);
2129 	if (ieee80211_queue_stopped(&local->hw, q)) {
2130 		IEEE80211_IFSTA_MESH_CTR_INC(ifmsh, dropped_frames_congestion);
2131 		return RX_DROP_MONITOR;
2132 	}
2133 	skb_set_queue_mapping(skb, q);
2134 
2135 	if (!--mesh_hdr->ttl) {
2136 		IEEE80211_IFSTA_MESH_CTR_INC(ifmsh, dropped_frames_ttl);
2137 		goto out;
2138 	}
2139 
2140 	if (!ifmsh->mshcfg.dot11MeshForwarding)
2141 		goto out;
2142 
2143 	fwd_skb = skb_copy(skb, GFP_ATOMIC);
2144 	if (!fwd_skb) {
2145 		net_info_ratelimited("%s: failed to clone mesh frame\n",
2146 				    sdata->name);
2147 		goto out;
2148 	}
2149 
2150 	fwd_hdr =  (struct ieee80211_hdr *) fwd_skb->data;
2151 	fwd_hdr->frame_control &= ~cpu_to_le16(IEEE80211_FCTL_RETRY);
2152 	info = IEEE80211_SKB_CB(fwd_skb);
2153 	memset(info, 0, sizeof(*info));
2154 	info->flags |= IEEE80211_TX_INTFL_NEED_TXPROCESSING;
2155 	info->control.vif = &rx->sdata->vif;
2156 	info->control.jiffies = jiffies;
2157 	if (is_multicast_ether_addr(fwd_hdr->addr1)) {
2158 		IEEE80211_IFSTA_MESH_CTR_INC(ifmsh, fwded_mcast);
2159 		memcpy(fwd_hdr->addr2, sdata->vif.addr, ETH_ALEN);
2160 		/* update power mode indication when forwarding */
2161 		ieee80211_mps_set_frame_flags(sdata, NULL, fwd_hdr);
2162 	} else if (!mesh_nexthop_lookup(sdata, fwd_skb)) {
2163 		/* mesh power mode flags updated in mesh_nexthop_lookup */
2164 		IEEE80211_IFSTA_MESH_CTR_INC(ifmsh, fwded_unicast);
2165 	} else {
2166 		/* unable to resolve next hop */
2167 		mesh_path_error_tx(sdata, ifmsh->mshcfg.element_ttl,
2168 				   fwd_hdr->addr3, 0, reason, fwd_hdr->addr2);
2169 		IEEE80211_IFSTA_MESH_CTR_INC(ifmsh, dropped_frames_no_route);
2170 		kfree_skb(fwd_skb);
2171 		return RX_DROP_MONITOR;
2172 	}
2173 
2174 	IEEE80211_IFSTA_MESH_CTR_INC(ifmsh, fwded_frames);
2175 	ieee80211_add_pending_skb(local, fwd_skb);
2176  out:
2177 	if (is_multicast_ether_addr(hdr->addr1) ||
2178 	    sdata->dev->flags & IFF_PROMISC)
2179 		return RX_CONTINUE;
2180 	else
2181 		return RX_DROP_MONITOR;
2182 }
2183 #endif
2184 
2185 static ieee80211_rx_result debug_noinline
2186 ieee80211_rx_h_data(struct ieee80211_rx_data *rx)
2187 {
2188 	struct ieee80211_sub_if_data *sdata = rx->sdata;
2189 	struct ieee80211_local *local = rx->local;
2190 	struct net_device *dev = sdata->dev;
2191 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
2192 	__le16 fc = hdr->frame_control;
2193 	bool port_control;
2194 	int err;
2195 
2196 	if (unlikely(!ieee80211_is_data(hdr->frame_control)))
2197 		return RX_CONTINUE;
2198 
2199 	if (unlikely(!ieee80211_is_data_present(hdr->frame_control)))
2200 		return RX_DROP_MONITOR;
2201 
2202 	/*
2203 	 * Send unexpected-4addr-frame event to hostapd. For older versions,
2204 	 * also drop the frame to cooked monitor interfaces.
2205 	 */
2206 	if (ieee80211_has_a4(hdr->frame_control) &&
2207 	    sdata->vif.type == NL80211_IFTYPE_AP) {
2208 		if (rx->sta &&
2209 		    !test_and_set_sta_flag(rx->sta, WLAN_STA_4ADDR_EVENT))
2210 			cfg80211_rx_unexpected_4addr_frame(
2211 				rx->sdata->dev, rx->sta->sta.addr, GFP_ATOMIC);
2212 		return RX_DROP_MONITOR;
2213 	}
2214 
2215 	err = __ieee80211_data_to_8023(rx, &port_control);
2216 	if (unlikely(err))
2217 		return RX_DROP_UNUSABLE;
2218 
2219 	if (!ieee80211_frame_allowed(rx, fc))
2220 		return RX_DROP_MONITOR;
2221 
2222 	if (rx->sdata->vif.type == NL80211_IFTYPE_AP_VLAN &&
2223 	    unlikely(port_control) && sdata->bss) {
2224 		sdata = container_of(sdata->bss, struct ieee80211_sub_if_data,
2225 				     u.ap);
2226 		dev = sdata->dev;
2227 		rx->sdata = sdata;
2228 	}
2229 
2230 	rx->skb->dev = dev;
2231 
2232 	dev->stats.rx_packets++;
2233 	dev->stats.rx_bytes += rx->skb->len;
2234 
2235 	if (local->ps_sdata && local->hw.conf.dynamic_ps_timeout > 0 &&
2236 	    !is_multicast_ether_addr(
2237 		    ((struct ethhdr *)rx->skb->data)->h_dest) &&
2238 	    (!local->scanning &&
2239 	     !test_bit(SDATA_STATE_OFFCHANNEL, &sdata->state))) {
2240 			mod_timer(&local->dynamic_ps_timer, jiffies +
2241 			 msecs_to_jiffies(local->hw.conf.dynamic_ps_timeout));
2242 	}
2243 
2244 	ieee80211_deliver_skb(rx);
2245 
2246 	return RX_QUEUED;
2247 }
2248 
2249 static ieee80211_rx_result debug_noinline
2250 ieee80211_rx_h_ctrl(struct ieee80211_rx_data *rx, struct sk_buff_head *frames)
2251 {
2252 	struct sk_buff *skb = rx->skb;
2253 	struct ieee80211_bar *bar = (struct ieee80211_bar *)skb->data;
2254 	struct tid_ampdu_rx *tid_agg_rx;
2255 	u16 start_seq_num;
2256 	u16 tid;
2257 
2258 	if (likely(!ieee80211_is_ctl(bar->frame_control)))
2259 		return RX_CONTINUE;
2260 
2261 	if (ieee80211_is_back_req(bar->frame_control)) {
2262 		struct {
2263 			__le16 control, start_seq_num;
2264 		} __packed bar_data;
2265 
2266 		if (!rx->sta)
2267 			return RX_DROP_MONITOR;
2268 
2269 		if (skb_copy_bits(skb, offsetof(struct ieee80211_bar, control),
2270 				  &bar_data, sizeof(bar_data)))
2271 			return RX_DROP_MONITOR;
2272 
2273 		tid = le16_to_cpu(bar_data.control) >> 12;
2274 
2275 		tid_agg_rx = rcu_dereference(rx->sta->ampdu_mlme.tid_rx[tid]);
2276 		if (!tid_agg_rx)
2277 			return RX_DROP_MONITOR;
2278 
2279 		start_seq_num = le16_to_cpu(bar_data.start_seq_num) >> 4;
2280 
2281 		/* reset session timer */
2282 		if (tid_agg_rx->timeout)
2283 			mod_timer(&tid_agg_rx->session_timer,
2284 				  TU_TO_EXP_TIME(tid_agg_rx->timeout));
2285 
2286 		spin_lock(&tid_agg_rx->reorder_lock);
2287 		/* release stored frames up to start of BAR */
2288 		ieee80211_release_reorder_frames(rx->sdata, tid_agg_rx,
2289 						 start_seq_num, frames);
2290 		spin_unlock(&tid_agg_rx->reorder_lock);
2291 
2292 		kfree_skb(skb);
2293 		return RX_QUEUED;
2294 	}
2295 
2296 	/*
2297 	 * After this point, we only want management frames,
2298 	 * so we can drop all remaining control frames to
2299 	 * cooked monitor interfaces.
2300 	 */
2301 	return RX_DROP_MONITOR;
2302 }
2303 
2304 static void ieee80211_process_sa_query_req(struct ieee80211_sub_if_data *sdata,
2305 					   struct ieee80211_mgmt *mgmt,
2306 					   size_t len)
2307 {
2308 	struct ieee80211_local *local = sdata->local;
2309 	struct sk_buff *skb;
2310 	struct ieee80211_mgmt *resp;
2311 
2312 	if (!ether_addr_equal(mgmt->da, sdata->vif.addr)) {
2313 		/* Not to own unicast address */
2314 		return;
2315 	}
2316 
2317 	if (!ether_addr_equal(mgmt->sa, sdata->u.mgd.bssid) ||
2318 	    !ether_addr_equal(mgmt->bssid, sdata->u.mgd.bssid)) {
2319 		/* Not from the current AP or not associated yet. */
2320 		return;
2321 	}
2322 
2323 	if (len < 24 + 1 + sizeof(resp->u.action.u.sa_query)) {
2324 		/* Too short SA Query request frame */
2325 		return;
2326 	}
2327 
2328 	skb = dev_alloc_skb(sizeof(*resp) + local->hw.extra_tx_headroom);
2329 	if (skb == NULL)
2330 		return;
2331 
2332 	skb_reserve(skb, local->hw.extra_tx_headroom);
2333 	resp = (struct ieee80211_mgmt *) skb_put(skb, 24);
2334 	memset(resp, 0, 24);
2335 	memcpy(resp->da, mgmt->sa, ETH_ALEN);
2336 	memcpy(resp->sa, sdata->vif.addr, ETH_ALEN);
2337 	memcpy(resp->bssid, sdata->u.mgd.bssid, ETH_ALEN);
2338 	resp->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
2339 					  IEEE80211_STYPE_ACTION);
2340 	skb_put(skb, 1 + sizeof(resp->u.action.u.sa_query));
2341 	resp->u.action.category = WLAN_CATEGORY_SA_QUERY;
2342 	resp->u.action.u.sa_query.action = WLAN_ACTION_SA_QUERY_RESPONSE;
2343 	memcpy(resp->u.action.u.sa_query.trans_id,
2344 	       mgmt->u.action.u.sa_query.trans_id,
2345 	       WLAN_SA_QUERY_TR_ID_LEN);
2346 
2347 	ieee80211_tx_skb(sdata, skb);
2348 }
2349 
2350 static ieee80211_rx_result debug_noinline
2351 ieee80211_rx_h_mgmt_check(struct ieee80211_rx_data *rx)
2352 {
2353 	struct ieee80211_mgmt *mgmt = (struct ieee80211_mgmt *) rx->skb->data;
2354 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
2355 
2356 	/*
2357 	 * From here on, look only at management frames.
2358 	 * Data and control frames are already handled,
2359 	 * and unknown (reserved) frames are useless.
2360 	 */
2361 	if (rx->skb->len < 24)
2362 		return RX_DROP_MONITOR;
2363 
2364 	if (!ieee80211_is_mgmt(mgmt->frame_control))
2365 		return RX_DROP_MONITOR;
2366 
2367 	if (rx->sdata->vif.type == NL80211_IFTYPE_AP &&
2368 	    ieee80211_is_beacon(mgmt->frame_control) &&
2369 	    !(rx->flags & IEEE80211_RX_BEACON_REPORTED)) {
2370 		int sig = 0;
2371 
2372 		if (rx->local->hw.flags & IEEE80211_HW_SIGNAL_DBM)
2373 			sig = status->signal;
2374 
2375 		cfg80211_report_obss_beacon(rx->local->hw.wiphy,
2376 					    rx->skb->data, rx->skb->len,
2377 					    status->freq, sig);
2378 		rx->flags |= IEEE80211_RX_BEACON_REPORTED;
2379 	}
2380 
2381 	if (!(status->rx_flags & IEEE80211_RX_RA_MATCH))
2382 		return RX_DROP_MONITOR;
2383 
2384 	if (ieee80211_drop_unencrypted_mgmt(rx))
2385 		return RX_DROP_UNUSABLE;
2386 
2387 	return RX_CONTINUE;
2388 }
2389 
2390 static ieee80211_rx_result debug_noinline
2391 ieee80211_rx_h_action(struct ieee80211_rx_data *rx)
2392 {
2393 	struct ieee80211_local *local = rx->local;
2394 	struct ieee80211_sub_if_data *sdata = rx->sdata;
2395 	struct ieee80211_mgmt *mgmt = (struct ieee80211_mgmt *) rx->skb->data;
2396 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
2397 	int len = rx->skb->len;
2398 
2399 	if (!ieee80211_is_action(mgmt->frame_control))
2400 		return RX_CONTINUE;
2401 
2402 	/* drop too small frames */
2403 	if (len < IEEE80211_MIN_ACTION_SIZE)
2404 		return RX_DROP_UNUSABLE;
2405 
2406 	if (!rx->sta && mgmt->u.action.category != WLAN_CATEGORY_PUBLIC &&
2407 	    mgmt->u.action.category != WLAN_CATEGORY_SELF_PROTECTED &&
2408 	    mgmt->u.action.category != WLAN_CATEGORY_SPECTRUM_MGMT)
2409 		return RX_DROP_UNUSABLE;
2410 
2411 	if (!(status->rx_flags & IEEE80211_RX_RA_MATCH))
2412 		return RX_DROP_UNUSABLE;
2413 
2414 	switch (mgmt->u.action.category) {
2415 	case WLAN_CATEGORY_HT:
2416 		/* reject HT action frames from stations not supporting HT */
2417 		if (!rx->sta->sta.ht_cap.ht_supported)
2418 			goto invalid;
2419 
2420 		if (sdata->vif.type != NL80211_IFTYPE_STATION &&
2421 		    sdata->vif.type != NL80211_IFTYPE_MESH_POINT &&
2422 		    sdata->vif.type != NL80211_IFTYPE_AP_VLAN &&
2423 		    sdata->vif.type != NL80211_IFTYPE_AP &&
2424 		    sdata->vif.type != NL80211_IFTYPE_ADHOC)
2425 			break;
2426 
2427 		/* verify action & smps_control/chanwidth are present */
2428 		if (len < IEEE80211_MIN_ACTION_SIZE + 2)
2429 			goto invalid;
2430 
2431 		switch (mgmt->u.action.u.ht_smps.action) {
2432 		case WLAN_HT_ACTION_SMPS: {
2433 			struct ieee80211_supported_band *sband;
2434 			enum ieee80211_smps_mode smps_mode;
2435 
2436 			/* convert to HT capability */
2437 			switch (mgmt->u.action.u.ht_smps.smps_control) {
2438 			case WLAN_HT_SMPS_CONTROL_DISABLED:
2439 				smps_mode = IEEE80211_SMPS_OFF;
2440 				break;
2441 			case WLAN_HT_SMPS_CONTROL_STATIC:
2442 				smps_mode = IEEE80211_SMPS_STATIC;
2443 				break;
2444 			case WLAN_HT_SMPS_CONTROL_DYNAMIC:
2445 				smps_mode = IEEE80211_SMPS_DYNAMIC;
2446 				break;
2447 			default:
2448 				goto invalid;
2449 			}
2450 
2451 			/* if no change do nothing */
2452 			if (rx->sta->sta.smps_mode == smps_mode)
2453 				goto handled;
2454 			rx->sta->sta.smps_mode = smps_mode;
2455 
2456 			sband = rx->local->hw.wiphy->bands[status->band];
2457 
2458 			rate_control_rate_update(local, sband, rx->sta,
2459 						 IEEE80211_RC_SMPS_CHANGED);
2460 			goto handled;
2461 		}
2462 		case WLAN_HT_ACTION_NOTIFY_CHANWIDTH: {
2463 			struct ieee80211_supported_band *sband;
2464 			u8 chanwidth = mgmt->u.action.u.ht_notify_cw.chanwidth;
2465 			enum ieee80211_sta_rx_bandwidth new_bw;
2466 
2467 			/* If it doesn't support 40 MHz it can't change ... */
2468 			if (!(rx->sta->sta.ht_cap.cap &
2469 					IEEE80211_HT_CAP_SUP_WIDTH_20_40))
2470 				goto handled;
2471 
2472 			if (chanwidth == IEEE80211_HT_CHANWIDTH_20MHZ)
2473 				new_bw = IEEE80211_STA_RX_BW_20;
2474 			else
2475 				new_bw = ieee80211_sta_cur_vht_bw(rx->sta);
2476 
2477 			if (rx->sta->sta.bandwidth == new_bw)
2478 				goto handled;
2479 
2480 			sband = rx->local->hw.wiphy->bands[status->band];
2481 
2482 			rate_control_rate_update(local, sband, rx->sta,
2483 						 IEEE80211_RC_BW_CHANGED);
2484 			goto handled;
2485 		}
2486 		default:
2487 			goto invalid;
2488 		}
2489 
2490 		break;
2491 	case WLAN_CATEGORY_PUBLIC:
2492 		if (len < IEEE80211_MIN_ACTION_SIZE + 1)
2493 			goto invalid;
2494 		if (sdata->vif.type != NL80211_IFTYPE_STATION)
2495 			break;
2496 		if (!rx->sta)
2497 			break;
2498 		if (!ether_addr_equal(mgmt->bssid, sdata->u.mgd.bssid))
2499 			break;
2500 		if (mgmt->u.action.u.ext_chan_switch.action_code !=
2501 				WLAN_PUB_ACTION_EXT_CHANSW_ANN)
2502 			break;
2503 		if (len < offsetof(struct ieee80211_mgmt,
2504 				   u.action.u.ext_chan_switch.variable))
2505 			goto invalid;
2506 		goto queue;
2507 	case WLAN_CATEGORY_VHT:
2508 		if (sdata->vif.type != NL80211_IFTYPE_STATION &&
2509 		    sdata->vif.type != NL80211_IFTYPE_MESH_POINT &&
2510 		    sdata->vif.type != NL80211_IFTYPE_AP_VLAN &&
2511 		    sdata->vif.type != NL80211_IFTYPE_AP &&
2512 		    sdata->vif.type != NL80211_IFTYPE_ADHOC)
2513 			break;
2514 
2515 		/* verify action code is present */
2516 		if (len < IEEE80211_MIN_ACTION_SIZE + 1)
2517 			goto invalid;
2518 
2519 		switch (mgmt->u.action.u.vht_opmode_notif.action_code) {
2520 		case WLAN_VHT_ACTION_OPMODE_NOTIF: {
2521 			u8 opmode;
2522 
2523 			/* verify opmode is present */
2524 			if (len < IEEE80211_MIN_ACTION_SIZE + 2)
2525 				goto invalid;
2526 
2527 			opmode = mgmt->u.action.u.vht_opmode_notif.operating_mode;
2528 
2529 			ieee80211_vht_handle_opmode(rx->sdata, rx->sta,
2530 						    opmode, status->band,
2531 						    false);
2532 			goto handled;
2533 		}
2534 		default:
2535 			break;
2536 		}
2537 		break;
2538 	case WLAN_CATEGORY_BACK:
2539 		if (sdata->vif.type != NL80211_IFTYPE_STATION &&
2540 		    sdata->vif.type != NL80211_IFTYPE_MESH_POINT &&
2541 		    sdata->vif.type != NL80211_IFTYPE_AP_VLAN &&
2542 		    sdata->vif.type != NL80211_IFTYPE_AP &&
2543 		    sdata->vif.type != NL80211_IFTYPE_ADHOC)
2544 			break;
2545 
2546 		/* verify action_code is present */
2547 		if (len < IEEE80211_MIN_ACTION_SIZE + 1)
2548 			break;
2549 
2550 		switch (mgmt->u.action.u.addba_req.action_code) {
2551 		case WLAN_ACTION_ADDBA_REQ:
2552 			if (len < (IEEE80211_MIN_ACTION_SIZE +
2553 				   sizeof(mgmt->u.action.u.addba_req)))
2554 				goto invalid;
2555 			break;
2556 		case WLAN_ACTION_ADDBA_RESP:
2557 			if (len < (IEEE80211_MIN_ACTION_SIZE +
2558 				   sizeof(mgmt->u.action.u.addba_resp)))
2559 				goto invalid;
2560 			break;
2561 		case WLAN_ACTION_DELBA:
2562 			if (len < (IEEE80211_MIN_ACTION_SIZE +
2563 				   sizeof(mgmt->u.action.u.delba)))
2564 				goto invalid;
2565 			break;
2566 		default:
2567 			goto invalid;
2568 		}
2569 
2570 		goto queue;
2571 	case WLAN_CATEGORY_SPECTRUM_MGMT:
2572 		/* verify action_code is present */
2573 		if (len < IEEE80211_MIN_ACTION_SIZE + 1)
2574 			break;
2575 
2576 		switch (mgmt->u.action.u.measurement.action_code) {
2577 		case WLAN_ACTION_SPCT_MSR_REQ:
2578 			if (status->band != IEEE80211_BAND_5GHZ)
2579 				break;
2580 
2581 			if (len < (IEEE80211_MIN_ACTION_SIZE +
2582 				   sizeof(mgmt->u.action.u.measurement)))
2583 				break;
2584 
2585 			if (sdata->vif.type != NL80211_IFTYPE_STATION)
2586 				break;
2587 
2588 			ieee80211_process_measurement_req(sdata, mgmt, len);
2589 			goto handled;
2590 		case WLAN_ACTION_SPCT_CHL_SWITCH: {
2591 			u8 *bssid;
2592 			if (len < (IEEE80211_MIN_ACTION_SIZE +
2593 				   sizeof(mgmt->u.action.u.chan_switch)))
2594 				break;
2595 
2596 			if (sdata->vif.type != NL80211_IFTYPE_STATION &&
2597 			    sdata->vif.type != NL80211_IFTYPE_ADHOC &&
2598 			    sdata->vif.type != NL80211_IFTYPE_MESH_POINT)
2599 				break;
2600 
2601 			if (sdata->vif.type == NL80211_IFTYPE_STATION)
2602 				bssid = sdata->u.mgd.bssid;
2603 			else if (sdata->vif.type == NL80211_IFTYPE_ADHOC)
2604 				bssid = sdata->u.ibss.bssid;
2605 			else if (sdata->vif.type == NL80211_IFTYPE_MESH_POINT)
2606 				bssid = mgmt->sa;
2607 			else
2608 				break;
2609 
2610 			if (!ether_addr_equal(mgmt->bssid, bssid))
2611 				break;
2612 
2613 			goto queue;
2614 			}
2615 		}
2616 		break;
2617 	case WLAN_CATEGORY_SA_QUERY:
2618 		if (len < (IEEE80211_MIN_ACTION_SIZE +
2619 			   sizeof(mgmt->u.action.u.sa_query)))
2620 			break;
2621 
2622 		switch (mgmt->u.action.u.sa_query.action) {
2623 		case WLAN_ACTION_SA_QUERY_REQUEST:
2624 			if (sdata->vif.type != NL80211_IFTYPE_STATION)
2625 				break;
2626 			ieee80211_process_sa_query_req(sdata, mgmt, len);
2627 			goto handled;
2628 		}
2629 		break;
2630 	case WLAN_CATEGORY_SELF_PROTECTED:
2631 		if (len < (IEEE80211_MIN_ACTION_SIZE +
2632 			   sizeof(mgmt->u.action.u.self_prot.action_code)))
2633 			break;
2634 
2635 		switch (mgmt->u.action.u.self_prot.action_code) {
2636 		case WLAN_SP_MESH_PEERING_OPEN:
2637 		case WLAN_SP_MESH_PEERING_CLOSE:
2638 		case WLAN_SP_MESH_PEERING_CONFIRM:
2639 			if (!ieee80211_vif_is_mesh(&sdata->vif))
2640 				goto invalid;
2641 			if (sdata->u.mesh.user_mpm)
2642 				/* userspace handles this frame */
2643 				break;
2644 			goto queue;
2645 		case WLAN_SP_MGK_INFORM:
2646 		case WLAN_SP_MGK_ACK:
2647 			if (!ieee80211_vif_is_mesh(&sdata->vif))
2648 				goto invalid;
2649 			break;
2650 		}
2651 		break;
2652 	case WLAN_CATEGORY_MESH_ACTION:
2653 		if (len < (IEEE80211_MIN_ACTION_SIZE +
2654 			   sizeof(mgmt->u.action.u.mesh_action.action_code)))
2655 			break;
2656 
2657 		if (!ieee80211_vif_is_mesh(&sdata->vif))
2658 			break;
2659 		if (mesh_action_is_path_sel(mgmt) &&
2660 		    !mesh_path_sel_is_hwmp(sdata))
2661 			break;
2662 		goto queue;
2663 	}
2664 
2665 	return RX_CONTINUE;
2666 
2667  invalid:
2668 	status->rx_flags |= IEEE80211_RX_MALFORMED_ACTION_FRM;
2669 	/* will return in the next handlers */
2670 	return RX_CONTINUE;
2671 
2672  handled:
2673 	if (rx->sta)
2674 		rx->sta->rx_packets++;
2675 	dev_kfree_skb(rx->skb);
2676 	return RX_QUEUED;
2677 
2678  queue:
2679 	rx->skb->pkt_type = IEEE80211_SDATA_QUEUE_TYPE_FRAME;
2680 	skb_queue_tail(&sdata->skb_queue, rx->skb);
2681 	ieee80211_queue_work(&local->hw, &sdata->work);
2682 	if (rx->sta)
2683 		rx->sta->rx_packets++;
2684 	return RX_QUEUED;
2685 }
2686 
2687 static ieee80211_rx_result debug_noinline
2688 ieee80211_rx_h_userspace_mgmt(struct ieee80211_rx_data *rx)
2689 {
2690 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
2691 	int sig = 0;
2692 
2693 	/* skip known-bad action frames and return them in the next handler */
2694 	if (status->rx_flags & IEEE80211_RX_MALFORMED_ACTION_FRM)
2695 		return RX_CONTINUE;
2696 
2697 	/*
2698 	 * Getting here means the kernel doesn't know how to handle
2699 	 * it, but maybe userspace does ... include returned frames
2700 	 * so userspace can register for those to know whether ones
2701 	 * it transmitted were processed or returned.
2702 	 */
2703 
2704 	if (rx->local->hw.flags & IEEE80211_HW_SIGNAL_DBM)
2705 		sig = status->signal;
2706 
2707 	if (cfg80211_rx_mgmt(&rx->sdata->wdev, status->freq, sig,
2708 			     rx->skb->data, rx->skb->len, 0, GFP_ATOMIC)) {
2709 		if (rx->sta)
2710 			rx->sta->rx_packets++;
2711 		dev_kfree_skb(rx->skb);
2712 		return RX_QUEUED;
2713 	}
2714 
2715 	return RX_CONTINUE;
2716 }
2717 
2718 static ieee80211_rx_result debug_noinline
2719 ieee80211_rx_h_action_return(struct ieee80211_rx_data *rx)
2720 {
2721 	struct ieee80211_local *local = rx->local;
2722 	struct ieee80211_mgmt *mgmt = (struct ieee80211_mgmt *) rx->skb->data;
2723 	struct sk_buff *nskb;
2724 	struct ieee80211_sub_if_data *sdata = rx->sdata;
2725 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
2726 
2727 	if (!ieee80211_is_action(mgmt->frame_control))
2728 		return RX_CONTINUE;
2729 
2730 	/*
2731 	 * For AP mode, hostapd is responsible for handling any action
2732 	 * frames that we didn't handle, including returning unknown
2733 	 * ones. For all other modes we will return them to the sender,
2734 	 * setting the 0x80 bit in the action category, as required by
2735 	 * 802.11-2012 9.24.4.
2736 	 * Newer versions of hostapd shall also use the management frame
2737 	 * registration mechanisms, but older ones still use cooked
2738 	 * monitor interfaces so push all frames there.
2739 	 */
2740 	if (!(status->rx_flags & IEEE80211_RX_MALFORMED_ACTION_FRM) &&
2741 	    (sdata->vif.type == NL80211_IFTYPE_AP ||
2742 	     sdata->vif.type == NL80211_IFTYPE_AP_VLAN))
2743 		return RX_DROP_MONITOR;
2744 
2745 	if (is_multicast_ether_addr(mgmt->da))
2746 		return RX_DROP_MONITOR;
2747 
2748 	/* do not return rejected action frames */
2749 	if (mgmt->u.action.category & 0x80)
2750 		return RX_DROP_UNUSABLE;
2751 
2752 	nskb = skb_copy_expand(rx->skb, local->hw.extra_tx_headroom, 0,
2753 			       GFP_ATOMIC);
2754 	if (nskb) {
2755 		struct ieee80211_mgmt *nmgmt = (void *)nskb->data;
2756 
2757 		nmgmt->u.action.category |= 0x80;
2758 		memcpy(nmgmt->da, nmgmt->sa, ETH_ALEN);
2759 		memcpy(nmgmt->sa, rx->sdata->vif.addr, ETH_ALEN);
2760 
2761 		memset(nskb->cb, 0, sizeof(nskb->cb));
2762 
2763 		if (rx->sdata->vif.type == NL80211_IFTYPE_P2P_DEVICE) {
2764 			struct ieee80211_tx_info *info = IEEE80211_SKB_CB(nskb);
2765 
2766 			info->flags = IEEE80211_TX_CTL_TX_OFFCHAN |
2767 				      IEEE80211_TX_INTFL_OFFCHAN_TX_OK |
2768 				      IEEE80211_TX_CTL_NO_CCK_RATE;
2769 			if (local->hw.flags & IEEE80211_HW_QUEUE_CONTROL)
2770 				info->hw_queue =
2771 					local->hw.offchannel_tx_hw_queue;
2772 		}
2773 
2774 		__ieee80211_tx_skb_tid_band(rx->sdata, nskb, 7,
2775 					    status->band);
2776 	}
2777 	dev_kfree_skb(rx->skb);
2778 	return RX_QUEUED;
2779 }
2780 
2781 static ieee80211_rx_result debug_noinline
2782 ieee80211_rx_h_mgmt(struct ieee80211_rx_data *rx)
2783 {
2784 	struct ieee80211_sub_if_data *sdata = rx->sdata;
2785 	struct ieee80211_mgmt *mgmt = (void *)rx->skb->data;
2786 	__le16 stype;
2787 
2788 	stype = mgmt->frame_control & cpu_to_le16(IEEE80211_FCTL_STYPE);
2789 
2790 	if (!ieee80211_vif_is_mesh(&sdata->vif) &&
2791 	    sdata->vif.type != NL80211_IFTYPE_ADHOC &&
2792 	    sdata->vif.type != NL80211_IFTYPE_STATION)
2793 		return RX_DROP_MONITOR;
2794 
2795 	switch (stype) {
2796 	case cpu_to_le16(IEEE80211_STYPE_AUTH):
2797 	case cpu_to_le16(IEEE80211_STYPE_BEACON):
2798 	case cpu_to_le16(IEEE80211_STYPE_PROBE_RESP):
2799 		/* process for all: mesh, mlme, ibss */
2800 		break;
2801 	case cpu_to_le16(IEEE80211_STYPE_ASSOC_RESP):
2802 	case cpu_to_le16(IEEE80211_STYPE_REASSOC_RESP):
2803 	case cpu_to_le16(IEEE80211_STYPE_DEAUTH):
2804 	case cpu_to_le16(IEEE80211_STYPE_DISASSOC):
2805 		if (is_multicast_ether_addr(mgmt->da) &&
2806 		    !is_broadcast_ether_addr(mgmt->da))
2807 			return RX_DROP_MONITOR;
2808 
2809 		/* process only for station */
2810 		if (sdata->vif.type != NL80211_IFTYPE_STATION)
2811 			return RX_DROP_MONITOR;
2812 		break;
2813 	case cpu_to_le16(IEEE80211_STYPE_PROBE_REQ):
2814 		/* process only for ibss and mesh */
2815 		if (sdata->vif.type != NL80211_IFTYPE_ADHOC &&
2816 		    sdata->vif.type != NL80211_IFTYPE_MESH_POINT)
2817 			return RX_DROP_MONITOR;
2818 		break;
2819 	default:
2820 		return RX_DROP_MONITOR;
2821 	}
2822 
2823 	/* queue up frame and kick off work to process it */
2824 	rx->skb->pkt_type = IEEE80211_SDATA_QUEUE_TYPE_FRAME;
2825 	skb_queue_tail(&sdata->skb_queue, rx->skb);
2826 	ieee80211_queue_work(&rx->local->hw, &sdata->work);
2827 	if (rx->sta)
2828 		rx->sta->rx_packets++;
2829 
2830 	return RX_QUEUED;
2831 }
2832 
2833 /* TODO: use IEEE80211_RX_FRAGMENTED */
2834 static void ieee80211_rx_cooked_monitor(struct ieee80211_rx_data *rx,
2835 					struct ieee80211_rate *rate)
2836 {
2837 	struct ieee80211_sub_if_data *sdata;
2838 	struct ieee80211_local *local = rx->local;
2839 	struct sk_buff *skb = rx->skb, *skb2;
2840 	struct net_device *prev_dev = NULL;
2841 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
2842 	int needed_headroom;
2843 
2844 	/*
2845 	 * If cooked monitor has been processed already, then
2846 	 * don't do it again. If not, set the flag.
2847 	 */
2848 	if (rx->flags & IEEE80211_RX_CMNTR)
2849 		goto out_free_skb;
2850 	rx->flags |= IEEE80211_RX_CMNTR;
2851 
2852 	/* If there are no cooked monitor interfaces, just free the SKB */
2853 	if (!local->cooked_mntrs)
2854 		goto out_free_skb;
2855 
2856 	/* room for the radiotap header based on driver features */
2857 	needed_headroom = ieee80211_rx_radiotap_space(local, status);
2858 
2859 	if (skb_headroom(skb) < needed_headroom &&
2860 	    pskb_expand_head(skb, needed_headroom, 0, GFP_ATOMIC))
2861 		goto out_free_skb;
2862 
2863 	/* prepend radiotap information */
2864 	ieee80211_add_rx_radiotap_header(local, skb, rate, needed_headroom,
2865 					 false);
2866 
2867 	skb_set_mac_header(skb, 0);
2868 	skb->ip_summed = CHECKSUM_UNNECESSARY;
2869 	skb->pkt_type = PACKET_OTHERHOST;
2870 	skb->protocol = htons(ETH_P_802_2);
2871 
2872 	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
2873 		if (!ieee80211_sdata_running(sdata))
2874 			continue;
2875 
2876 		if (sdata->vif.type != NL80211_IFTYPE_MONITOR ||
2877 		    !(sdata->u.mntr_flags & MONITOR_FLAG_COOK_FRAMES))
2878 			continue;
2879 
2880 		if (prev_dev) {
2881 			skb2 = skb_clone(skb, GFP_ATOMIC);
2882 			if (skb2) {
2883 				skb2->dev = prev_dev;
2884 				netif_receive_skb(skb2);
2885 			}
2886 		}
2887 
2888 		prev_dev = sdata->dev;
2889 		sdata->dev->stats.rx_packets++;
2890 		sdata->dev->stats.rx_bytes += skb->len;
2891 	}
2892 
2893 	if (prev_dev) {
2894 		skb->dev = prev_dev;
2895 		netif_receive_skb(skb);
2896 		return;
2897 	}
2898 
2899  out_free_skb:
2900 	dev_kfree_skb(skb);
2901 }
2902 
2903 static void ieee80211_rx_handlers_result(struct ieee80211_rx_data *rx,
2904 					 ieee80211_rx_result res)
2905 {
2906 	switch (res) {
2907 	case RX_DROP_MONITOR:
2908 		I802_DEBUG_INC(rx->sdata->local->rx_handlers_drop);
2909 		if (rx->sta)
2910 			rx->sta->rx_dropped++;
2911 		/* fall through */
2912 	case RX_CONTINUE: {
2913 		struct ieee80211_rate *rate = NULL;
2914 		struct ieee80211_supported_band *sband;
2915 		struct ieee80211_rx_status *status;
2916 
2917 		status = IEEE80211_SKB_RXCB((rx->skb));
2918 
2919 		sband = rx->local->hw.wiphy->bands[status->band];
2920 		if (!(status->flag & RX_FLAG_HT) &&
2921 		    !(status->flag & RX_FLAG_VHT))
2922 			rate = &sband->bitrates[status->rate_idx];
2923 
2924 		ieee80211_rx_cooked_monitor(rx, rate);
2925 		break;
2926 		}
2927 	case RX_DROP_UNUSABLE:
2928 		I802_DEBUG_INC(rx->sdata->local->rx_handlers_drop);
2929 		if (rx->sta)
2930 			rx->sta->rx_dropped++;
2931 		dev_kfree_skb(rx->skb);
2932 		break;
2933 	case RX_QUEUED:
2934 		I802_DEBUG_INC(rx->sdata->local->rx_handlers_queued);
2935 		break;
2936 	}
2937 }
2938 
2939 static void ieee80211_rx_handlers(struct ieee80211_rx_data *rx,
2940 				  struct sk_buff_head *frames)
2941 {
2942 	ieee80211_rx_result res = RX_DROP_MONITOR;
2943 	struct sk_buff *skb;
2944 
2945 #define CALL_RXH(rxh)			\
2946 	do {				\
2947 		res = rxh(rx);		\
2948 		if (res != RX_CONTINUE)	\
2949 			goto rxh_next;  \
2950 	} while (0);
2951 
2952 	spin_lock_bh(&rx->local->rx_path_lock);
2953 
2954 	while ((skb = __skb_dequeue(frames))) {
2955 		/*
2956 		 * all the other fields are valid across frames
2957 		 * that belong to an aMPDU since they are on the
2958 		 * same TID from the same station
2959 		 */
2960 		rx->skb = skb;
2961 
2962 		CALL_RXH(ieee80211_rx_h_check_more_data)
2963 		CALL_RXH(ieee80211_rx_h_uapsd_and_pspoll)
2964 		CALL_RXH(ieee80211_rx_h_sta_process)
2965 		CALL_RXH(ieee80211_rx_h_decrypt)
2966 		CALL_RXH(ieee80211_rx_h_defragment)
2967 		CALL_RXH(ieee80211_rx_h_michael_mic_verify)
2968 		/* must be after MMIC verify so header is counted in MPDU mic */
2969 #ifdef CONFIG_MAC80211_MESH
2970 		if (ieee80211_vif_is_mesh(&rx->sdata->vif))
2971 			CALL_RXH(ieee80211_rx_h_mesh_fwding);
2972 #endif
2973 		CALL_RXH(ieee80211_rx_h_amsdu)
2974 		CALL_RXH(ieee80211_rx_h_data)
2975 
2976 		/* special treatment -- needs the queue */
2977 		res = ieee80211_rx_h_ctrl(rx, frames);
2978 		if (res != RX_CONTINUE)
2979 			goto rxh_next;
2980 
2981 		CALL_RXH(ieee80211_rx_h_mgmt_check)
2982 		CALL_RXH(ieee80211_rx_h_action)
2983 		CALL_RXH(ieee80211_rx_h_userspace_mgmt)
2984 		CALL_RXH(ieee80211_rx_h_action_return)
2985 		CALL_RXH(ieee80211_rx_h_mgmt)
2986 
2987  rxh_next:
2988 		ieee80211_rx_handlers_result(rx, res);
2989 
2990 #undef CALL_RXH
2991 	}
2992 
2993 	spin_unlock_bh(&rx->local->rx_path_lock);
2994 }
2995 
2996 static void ieee80211_invoke_rx_handlers(struct ieee80211_rx_data *rx)
2997 {
2998 	struct sk_buff_head reorder_release;
2999 	ieee80211_rx_result res = RX_DROP_MONITOR;
3000 
3001 	__skb_queue_head_init(&reorder_release);
3002 
3003 #define CALL_RXH(rxh)			\
3004 	do {				\
3005 		res = rxh(rx);		\
3006 		if (res != RX_CONTINUE)	\
3007 			goto rxh_next;  \
3008 	} while (0);
3009 
3010 	CALL_RXH(ieee80211_rx_h_check)
3011 
3012 	ieee80211_rx_reorder_ampdu(rx, &reorder_release);
3013 
3014 	ieee80211_rx_handlers(rx, &reorder_release);
3015 	return;
3016 
3017  rxh_next:
3018 	ieee80211_rx_handlers_result(rx, res);
3019 
3020 #undef CALL_RXH
3021 }
3022 
3023 /*
3024  * This function makes calls into the RX path, therefore
3025  * it has to be invoked under RCU read lock.
3026  */
3027 void ieee80211_release_reorder_timeout(struct sta_info *sta, int tid)
3028 {
3029 	struct sk_buff_head frames;
3030 	struct ieee80211_rx_data rx = {
3031 		.sta = sta,
3032 		.sdata = sta->sdata,
3033 		.local = sta->local,
3034 		/* This is OK -- must be QoS data frame */
3035 		.security_idx = tid,
3036 		.seqno_idx = tid,
3037 		.flags = 0,
3038 	};
3039 	struct tid_ampdu_rx *tid_agg_rx;
3040 
3041 	tid_agg_rx = rcu_dereference(sta->ampdu_mlme.tid_rx[tid]);
3042 	if (!tid_agg_rx)
3043 		return;
3044 
3045 	__skb_queue_head_init(&frames);
3046 
3047 	spin_lock(&tid_agg_rx->reorder_lock);
3048 	ieee80211_sta_reorder_release(sta->sdata, tid_agg_rx, &frames);
3049 	spin_unlock(&tid_agg_rx->reorder_lock);
3050 
3051 	ieee80211_rx_handlers(&rx, &frames);
3052 }
3053 
3054 /* main receive path */
3055 
3056 static int prepare_for_handlers(struct ieee80211_rx_data *rx,
3057 				struct ieee80211_hdr *hdr)
3058 {
3059 	struct ieee80211_sub_if_data *sdata = rx->sdata;
3060 	struct sk_buff *skb = rx->skb;
3061 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
3062 	u8 *bssid = ieee80211_get_bssid(hdr, skb->len, sdata->vif.type);
3063 	int multicast = is_multicast_ether_addr(hdr->addr1);
3064 
3065 	switch (sdata->vif.type) {
3066 	case NL80211_IFTYPE_STATION:
3067 		if (!bssid && !sdata->u.mgd.use_4addr)
3068 			return 0;
3069 		if (!multicast &&
3070 		    !ether_addr_equal(sdata->vif.addr, hdr->addr1)) {
3071 			if (!(sdata->dev->flags & IFF_PROMISC) ||
3072 			    sdata->u.mgd.use_4addr)
3073 				return 0;
3074 			status->rx_flags &= ~IEEE80211_RX_RA_MATCH;
3075 		}
3076 		break;
3077 	case NL80211_IFTYPE_ADHOC:
3078 		if (!bssid)
3079 			return 0;
3080 		if (ether_addr_equal(sdata->vif.addr, hdr->addr2) ||
3081 		    ether_addr_equal(sdata->u.ibss.bssid, hdr->addr2))
3082 			return 0;
3083 		if (ieee80211_is_beacon(hdr->frame_control)) {
3084 			return 1;
3085 		} else if (!ieee80211_bssid_match(bssid, sdata->u.ibss.bssid)) {
3086 			return 0;
3087 		} else if (!multicast &&
3088 			   !ether_addr_equal(sdata->vif.addr, hdr->addr1)) {
3089 			if (!(sdata->dev->flags & IFF_PROMISC))
3090 				return 0;
3091 			status->rx_flags &= ~IEEE80211_RX_RA_MATCH;
3092 		} else if (!rx->sta) {
3093 			int rate_idx;
3094 			if (status->flag & (RX_FLAG_HT | RX_FLAG_VHT))
3095 				rate_idx = 0; /* TODO: HT/VHT rates */
3096 			else
3097 				rate_idx = status->rate_idx;
3098 			ieee80211_ibss_rx_no_sta(sdata, bssid, hdr->addr2,
3099 						 BIT(rate_idx));
3100 		}
3101 		break;
3102 	case NL80211_IFTYPE_MESH_POINT:
3103 		if (!multicast &&
3104 		    !ether_addr_equal(sdata->vif.addr, hdr->addr1)) {
3105 			if (!(sdata->dev->flags & IFF_PROMISC))
3106 				return 0;
3107 
3108 			status->rx_flags &= ~IEEE80211_RX_RA_MATCH;
3109 		}
3110 		break;
3111 	case NL80211_IFTYPE_AP_VLAN:
3112 	case NL80211_IFTYPE_AP:
3113 		if (!bssid) {
3114 			if (!ether_addr_equal(sdata->vif.addr, hdr->addr1))
3115 				return 0;
3116 		} else if (!ieee80211_bssid_match(bssid, sdata->vif.addr)) {
3117 			/*
3118 			 * Accept public action frames even when the
3119 			 * BSSID doesn't match, this is used for P2P
3120 			 * and location updates. Note that mac80211
3121 			 * itself never looks at these frames.
3122 			 */
3123 			if (!multicast &&
3124 			    !ether_addr_equal(sdata->vif.addr, hdr->addr1))
3125 				return 0;
3126 			if (ieee80211_is_public_action(hdr, skb->len))
3127 				return 1;
3128 			if (!ieee80211_is_beacon(hdr->frame_control))
3129 				return 0;
3130 			status->rx_flags &= ~IEEE80211_RX_RA_MATCH;
3131 		}
3132 		break;
3133 	case NL80211_IFTYPE_WDS:
3134 		if (bssid || !ieee80211_is_data(hdr->frame_control))
3135 			return 0;
3136 		if (!ether_addr_equal(sdata->u.wds.remote_addr, hdr->addr2))
3137 			return 0;
3138 		break;
3139 	case NL80211_IFTYPE_P2P_DEVICE:
3140 		if (!ieee80211_is_public_action(hdr, skb->len) &&
3141 		    !ieee80211_is_probe_req(hdr->frame_control) &&
3142 		    !ieee80211_is_probe_resp(hdr->frame_control) &&
3143 		    !ieee80211_is_beacon(hdr->frame_control))
3144 			return 0;
3145 		if (!ether_addr_equal(sdata->vif.addr, hdr->addr1) &&
3146 		    !multicast)
3147 			status->rx_flags &= ~IEEE80211_RX_RA_MATCH;
3148 		break;
3149 	default:
3150 		/* should never get here */
3151 		WARN_ON_ONCE(1);
3152 		break;
3153 	}
3154 
3155 	return 1;
3156 }
3157 
3158 /*
3159  * This function returns whether or not the SKB
3160  * was destined for RX processing or not, which,
3161  * if consume is true, is equivalent to whether
3162  * or not the skb was consumed.
3163  */
3164 static bool ieee80211_prepare_and_rx_handle(struct ieee80211_rx_data *rx,
3165 					    struct sk_buff *skb, bool consume)
3166 {
3167 	struct ieee80211_local *local = rx->local;
3168 	struct ieee80211_sub_if_data *sdata = rx->sdata;
3169 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
3170 	struct ieee80211_hdr *hdr = (void *)skb->data;
3171 	int prepares;
3172 
3173 	rx->skb = skb;
3174 	status->rx_flags |= IEEE80211_RX_RA_MATCH;
3175 	prepares = prepare_for_handlers(rx, hdr);
3176 
3177 	if (!prepares)
3178 		return false;
3179 
3180 	if (!consume) {
3181 		skb = skb_copy(skb, GFP_ATOMIC);
3182 		if (!skb) {
3183 			if (net_ratelimit())
3184 				wiphy_debug(local->hw.wiphy,
3185 					"failed to copy skb for %s\n",
3186 					sdata->name);
3187 			return true;
3188 		}
3189 
3190 		rx->skb = skb;
3191 	}
3192 
3193 	ieee80211_invoke_rx_handlers(rx);
3194 	return true;
3195 }
3196 
3197 /*
3198  * This is the actual Rx frames handler. as it blongs to Rx path it must
3199  * be called with rcu_read_lock protection.
3200  */
3201 static void __ieee80211_rx_handle_packet(struct ieee80211_hw *hw,
3202 					 struct sk_buff *skb)
3203 {
3204 	struct ieee80211_local *local = hw_to_local(hw);
3205 	struct ieee80211_sub_if_data *sdata;
3206 	struct ieee80211_hdr *hdr;
3207 	__le16 fc;
3208 	struct ieee80211_rx_data rx;
3209 	struct ieee80211_sub_if_data *prev;
3210 	struct sta_info *sta, *tmp, *prev_sta;
3211 	int err = 0;
3212 
3213 	fc = ((struct ieee80211_hdr *)skb->data)->frame_control;
3214 	memset(&rx, 0, sizeof(rx));
3215 	rx.skb = skb;
3216 	rx.local = local;
3217 
3218 	if (ieee80211_is_data(fc) || ieee80211_is_mgmt(fc))
3219 		local->dot11ReceivedFragmentCount++;
3220 
3221 	if (ieee80211_is_mgmt(fc)) {
3222 		/* drop frame if too short for header */
3223 		if (skb->len < ieee80211_hdrlen(fc))
3224 			err = -ENOBUFS;
3225 		else
3226 			err = skb_linearize(skb);
3227 	} else {
3228 		err = !pskb_may_pull(skb, ieee80211_hdrlen(fc));
3229 	}
3230 
3231 	if (err) {
3232 		dev_kfree_skb(skb);
3233 		return;
3234 	}
3235 
3236 	hdr = (struct ieee80211_hdr *)skb->data;
3237 	ieee80211_parse_qos(&rx);
3238 	ieee80211_verify_alignment(&rx);
3239 
3240 	if (unlikely(ieee80211_is_probe_resp(hdr->frame_control) ||
3241 		     ieee80211_is_beacon(hdr->frame_control)))
3242 		ieee80211_scan_rx(local, skb);
3243 
3244 	if (ieee80211_is_data(fc)) {
3245 		prev_sta = NULL;
3246 
3247 		for_each_sta_info(local, hdr->addr2, sta, tmp) {
3248 			if (!prev_sta) {
3249 				prev_sta = sta;
3250 				continue;
3251 			}
3252 
3253 			rx.sta = prev_sta;
3254 			rx.sdata = prev_sta->sdata;
3255 			ieee80211_prepare_and_rx_handle(&rx, skb, false);
3256 
3257 			prev_sta = sta;
3258 		}
3259 
3260 		if (prev_sta) {
3261 			rx.sta = prev_sta;
3262 			rx.sdata = prev_sta->sdata;
3263 
3264 			if (ieee80211_prepare_and_rx_handle(&rx, skb, true))
3265 				return;
3266 			goto out;
3267 		}
3268 	}
3269 
3270 	prev = NULL;
3271 
3272 	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
3273 		if (!ieee80211_sdata_running(sdata))
3274 			continue;
3275 
3276 		if (sdata->vif.type == NL80211_IFTYPE_MONITOR ||
3277 		    sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
3278 			continue;
3279 
3280 		/*
3281 		 * frame is destined for this interface, but if it's
3282 		 * not also for the previous one we handle that after
3283 		 * the loop to avoid copying the SKB once too much
3284 		 */
3285 
3286 		if (!prev) {
3287 			prev = sdata;
3288 			continue;
3289 		}
3290 
3291 		rx.sta = sta_info_get_bss(prev, hdr->addr2);
3292 		rx.sdata = prev;
3293 		ieee80211_prepare_and_rx_handle(&rx, skb, false);
3294 
3295 		prev = sdata;
3296 	}
3297 
3298 	if (prev) {
3299 		rx.sta = sta_info_get_bss(prev, hdr->addr2);
3300 		rx.sdata = prev;
3301 
3302 		if (ieee80211_prepare_and_rx_handle(&rx, skb, true))
3303 			return;
3304 	}
3305 
3306  out:
3307 	dev_kfree_skb(skb);
3308 }
3309 
3310 /*
3311  * This is the receive path handler. It is called by a low level driver when an
3312  * 802.11 MPDU is received from the hardware.
3313  */
3314 void ieee80211_rx(struct ieee80211_hw *hw, struct sk_buff *skb)
3315 {
3316 	struct ieee80211_local *local = hw_to_local(hw);
3317 	struct ieee80211_rate *rate = NULL;
3318 	struct ieee80211_supported_band *sband;
3319 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
3320 
3321 	WARN_ON_ONCE(softirq_count() == 0);
3322 
3323 	if (WARN_ON(status->band >= IEEE80211_NUM_BANDS))
3324 		goto drop;
3325 
3326 	sband = local->hw.wiphy->bands[status->band];
3327 	if (WARN_ON(!sband))
3328 		goto drop;
3329 
3330 	/*
3331 	 * If we're suspending, it is possible although not too likely
3332 	 * that we'd be receiving frames after having already partially
3333 	 * quiesced the stack. We can't process such frames then since
3334 	 * that might, for example, cause stations to be added or other
3335 	 * driver callbacks be invoked.
3336 	 */
3337 	if (unlikely(local->quiescing || local->suspended))
3338 		goto drop;
3339 
3340 	/* We might be during a HW reconfig, prevent Rx for the same reason */
3341 	if (unlikely(local->in_reconfig))
3342 		goto drop;
3343 
3344 	/*
3345 	 * The same happens when we're not even started,
3346 	 * but that's worth a warning.
3347 	 */
3348 	if (WARN_ON(!local->started))
3349 		goto drop;
3350 
3351 	if (likely(!(status->flag & RX_FLAG_FAILED_PLCP_CRC))) {
3352 		/*
3353 		 * Validate the rate, unless a PLCP error means that
3354 		 * we probably can't have a valid rate here anyway.
3355 		 */
3356 
3357 		if (status->flag & RX_FLAG_HT) {
3358 			/*
3359 			 * rate_idx is MCS index, which can be [0-76]
3360 			 * as documented on:
3361 			 *
3362 			 * http://wireless.kernel.org/en/developers/Documentation/ieee80211/802.11n
3363 			 *
3364 			 * Anything else would be some sort of driver or
3365 			 * hardware error. The driver should catch hardware
3366 			 * errors.
3367 			 */
3368 			if (WARN(status->rate_idx > 76,
3369 				 "Rate marked as an HT rate but passed "
3370 				 "status->rate_idx is not "
3371 				 "an MCS index [0-76]: %d (0x%02x)\n",
3372 				 status->rate_idx,
3373 				 status->rate_idx))
3374 				goto drop;
3375 		} else if (status->flag & RX_FLAG_VHT) {
3376 			if (WARN_ONCE(status->rate_idx > 9 ||
3377 				      !status->vht_nss ||
3378 				      status->vht_nss > 8,
3379 				      "Rate marked as a VHT rate but data is invalid: MCS: %d, NSS: %d\n",
3380 				      status->rate_idx, status->vht_nss))
3381 				goto drop;
3382 		} else {
3383 			if (WARN_ON(status->rate_idx >= sband->n_bitrates))
3384 				goto drop;
3385 			rate = &sband->bitrates[status->rate_idx];
3386 		}
3387 	}
3388 
3389 	status->rx_flags = 0;
3390 
3391 	/*
3392 	 * key references and virtual interfaces are protected using RCU
3393 	 * and this requires that we are in a read-side RCU section during
3394 	 * receive processing
3395 	 */
3396 	rcu_read_lock();
3397 
3398 	/*
3399 	 * Frames with failed FCS/PLCP checksum are not returned,
3400 	 * all other frames are returned without radiotap header
3401 	 * if it was previously present.
3402 	 * Also, frames with less than 16 bytes are dropped.
3403 	 */
3404 	skb = ieee80211_rx_monitor(local, skb, rate);
3405 	if (!skb) {
3406 		rcu_read_unlock();
3407 		return;
3408 	}
3409 
3410 	ieee80211_tpt_led_trig_rx(local,
3411 			((struct ieee80211_hdr *)skb->data)->frame_control,
3412 			skb->len);
3413 	__ieee80211_rx_handle_packet(hw, skb);
3414 
3415 	rcu_read_unlock();
3416 
3417 	return;
3418  drop:
3419 	kfree_skb(skb);
3420 }
3421 EXPORT_SYMBOL(ieee80211_rx);
3422 
3423 /* This is a version of the rx handler that can be called from hard irq
3424  * context. Post the skb on the queue and schedule the tasklet */
3425 void ieee80211_rx_irqsafe(struct ieee80211_hw *hw, struct sk_buff *skb)
3426 {
3427 	struct ieee80211_local *local = hw_to_local(hw);
3428 
3429 	BUILD_BUG_ON(sizeof(struct ieee80211_rx_status) > sizeof(skb->cb));
3430 
3431 	skb->pkt_type = IEEE80211_RX_MSG;
3432 	skb_queue_tail(&local->skb_queue, skb);
3433 	tasklet_schedule(&local->tasklet);
3434 }
3435 EXPORT_SYMBOL(ieee80211_rx_irqsafe);
3436