xref: /openbmc/linux/net/mac80211/rx.c (revision 6774def6)
1 /*
2  * Copyright 2002-2005, Instant802 Networks, Inc.
3  * Copyright 2005-2006, Devicescape Software, Inc.
4  * Copyright 2006-2007	Jiri Benc <jbenc@suse.cz>
5  * Copyright 2007-2010	Johannes Berg <johannes@sipsolutions.net>
6  * Copyright 2013-2014  Intel Mobile Communications GmbH
7  *
8  * This program is free software; you can redistribute it and/or modify
9  * it under the terms of the GNU General Public License version 2 as
10  * published by the Free Software Foundation.
11  */
12 
13 #include <linux/jiffies.h>
14 #include <linux/slab.h>
15 #include <linux/kernel.h>
16 #include <linux/skbuff.h>
17 #include <linux/netdevice.h>
18 #include <linux/etherdevice.h>
19 #include <linux/rcupdate.h>
20 #include <linux/export.h>
21 #include <net/mac80211.h>
22 #include <net/ieee80211_radiotap.h>
23 #include <asm/unaligned.h>
24 
25 #include "ieee80211_i.h"
26 #include "driver-ops.h"
27 #include "led.h"
28 #include "mesh.h"
29 #include "wep.h"
30 #include "wpa.h"
31 #include "tkip.h"
32 #include "wme.h"
33 #include "rate.h"
34 
35 /*
36  * monitor mode reception
37  *
38  * This function cleans up the SKB, i.e. it removes all the stuff
39  * only useful for monitoring.
40  */
41 static struct sk_buff *remove_monitor_info(struct ieee80211_local *local,
42 					   struct sk_buff *skb)
43 {
44 	if (local->hw.flags & IEEE80211_HW_RX_INCLUDES_FCS) {
45 		if (likely(skb->len > FCS_LEN))
46 			__pskb_trim(skb, skb->len - FCS_LEN);
47 		else {
48 			/* driver bug */
49 			WARN_ON(1);
50 			dev_kfree_skb(skb);
51 			return NULL;
52 		}
53 	}
54 
55 	return skb;
56 }
57 
58 static inline bool should_drop_frame(struct sk_buff *skb, int present_fcs_len)
59 {
60 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
61 	struct ieee80211_hdr *hdr = (void *)skb->data;
62 
63 	if (status->flag & (RX_FLAG_FAILED_FCS_CRC |
64 			    RX_FLAG_FAILED_PLCP_CRC |
65 			    RX_FLAG_AMPDU_IS_ZEROLEN))
66 		return true;
67 
68 	if (unlikely(skb->len < 16 + present_fcs_len))
69 		return true;
70 
71 	if (ieee80211_is_ctl(hdr->frame_control) &&
72 	    !ieee80211_is_pspoll(hdr->frame_control) &&
73 	    !ieee80211_is_back_req(hdr->frame_control))
74 		return true;
75 
76 	return false;
77 }
78 
79 static int
80 ieee80211_rx_radiotap_space(struct ieee80211_local *local,
81 			    struct ieee80211_rx_status *status)
82 {
83 	int len;
84 
85 	/* always present fields */
86 	len = sizeof(struct ieee80211_radiotap_header) + 8;
87 
88 	/* allocate extra bitmaps */
89 	if (status->chains)
90 		len += 4 * hweight8(status->chains);
91 
92 	if (ieee80211_have_rx_timestamp(status)) {
93 		len = ALIGN(len, 8);
94 		len += 8;
95 	}
96 	if (local->hw.flags & IEEE80211_HW_SIGNAL_DBM)
97 		len += 1;
98 
99 	/* antenna field, if we don't have per-chain info */
100 	if (!status->chains)
101 		len += 1;
102 
103 	/* padding for RX_FLAGS if necessary */
104 	len = ALIGN(len, 2);
105 
106 	if (status->flag & RX_FLAG_HT) /* HT info */
107 		len += 3;
108 
109 	if (status->flag & RX_FLAG_AMPDU_DETAILS) {
110 		len = ALIGN(len, 4);
111 		len += 8;
112 	}
113 
114 	if (status->flag & RX_FLAG_VHT) {
115 		len = ALIGN(len, 2);
116 		len += 12;
117 	}
118 
119 	if (status->chains) {
120 		/* antenna and antenna signal fields */
121 		len += 2 * hweight8(status->chains);
122 	}
123 
124 	return len;
125 }
126 
127 /*
128  * ieee80211_add_rx_radiotap_header - add radiotap header
129  *
130  * add a radiotap header containing all the fields which the hardware provided.
131  */
132 static void
133 ieee80211_add_rx_radiotap_header(struct ieee80211_local *local,
134 				 struct sk_buff *skb,
135 				 struct ieee80211_rate *rate,
136 				 int rtap_len, bool has_fcs)
137 {
138 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
139 	struct ieee80211_radiotap_header *rthdr;
140 	unsigned char *pos;
141 	__le32 *it_present;
142 	u32 it_present_val;
143 	u16 rx_flags = 0;
144 	u16 channel_flags = 0;
145 	int mpdulen, chain;
146 	unsigned long chains = status->chains;
147 
148 	mpdulen = skb->len;
149 	if (!(has_fcs && (local->hw.flags & IEEE80211_HW_RX_INCLUDES_FCS)))
150 		mpdulen += FCS_LEN;
151 
152 	rthdr = (struct ieee80211_radiotap_header *)skb_push(skb, rtap_len);
153 	memset(rthdr, 0, rtap_len);
154 	it_present = &rthdr->it_present;
155 
156 	/* radiotap header, set always present flags */
157 	rthdr->it_len = cpu_to_le16(rtap_len);
158 	it_present_val = BIT(IEEE80211_RADIOTAP_FLAGS) |
159 			 BIT(IEEE80211_RADIOTAP_CHANNEL) |
160 			 BIT(IEEE80211_RADIOTAP_RX_FLAGS);
161 
162 	if (!status->chains)
163 		it_present_val |= BIT(IEEE80211_RADIOTAP_ANTENNA);
164 
165 	for_each_set_bit(chain, &chains, IEEE80211_MAX_CHAINS) {
166 		it_present_val |=
167 			BIT(IEEE80211_RADIOTAP_EXT) |
168 			BIT(IEEE80211_RADIOTAP_RADIOTAP_NAMESPACE);
169 		put_unaligned_le32(it_present_val, it_present);
170 		it_present++;
171 		it_present_val = BIT(IEEE80211_RADIOTAP_ANTENNA) |
172 				 BIT(IEEE80211_RADIOTAP_DBM_ANTSIGNAL);
173 	}
174 
175 	put_unaligned_le32(it_present_val, it_present);
176 
177 	pos = (void *)(it_present + 1);
178 
179 	/* the order of the following fields is important */
180 
181 	/* IEEE80211_RADIOTAP_TSFT */
182 	if (ieee80211_have_rx_timestamp(status)) {
183 		/* padding */
184 		while ((pos - (u8 *)rthdr) & 7)
185 			*pos++ = 0;
186 		put_unaligned_le64(
187 			ieee80211_calculate_rx_timestamp(local, status,
188 							 mpdulen, 0),
189 			pos);
190 		rthdr->it_present |= cpu_to_le32(1 << IEEE80211_RADIOTAP_TSFT);
191 		pos += 8;
192 	}
193 
194 	/* IEEE80211_RADIOTAP_FLAGS */
195 	if (has_fcs && (local->hw.flags & IEEE80211_HW_RX_INCLUDES_FCS))
196 		*pos |= IEEE80211_RADIOTAP_F_FCS;
197 	if (status->flag & (RX_FLAG_FAILED_FCS_CRC | RX_FLAG_FAILED_PLCP_CRC))
198 		*pos |= IEEE80211_RADIOTAP_F_BADFCS;
199 	if (status->flag & RX_FLAG_SHORTPRE)
200 		*pos |= IEEE80211_RADIOTAP_F_SHORTPRE;
201 	pos++;
202 
203 	/* IEEE80211_RADIOTAP_RATE */
204 	if (!rate || status->flag & (RX_FLAG_HT | RX_FLAG_VHT)) {
205 		/*
206 		 * Without rate information don't add it. If we have,
207 		 * MCS information is a separate field in radiotap,
208 		 * added below. The byte here is needed as padding
209 		 * for the channel though, so initialise it to 0.
210 		 */
211 		*pos = 0;
212 	} else {
213 		int shift = 0;
214 		rthdr->it_present |= cpu_to_le32(1 << IEEE80211_RADIOTAP_RATE);
215 		if (status->flag & RX_FLAG_10MHZ)
216 			shift = 1;
217 		else if (status->flag & RX_FLAG_5MHZ)
218 			shift = 2;
219 		*pos = DIV_ROUND_UP(rate->bitrate, 5 * (1 << shift));
220 	}
221 	pos++;
222 
223 	/* IEEE80211_RADIOTAP_CHANNEL */
224 	put_unaligned_le16(status->freq, pos);
225 	pos += 2;
226 	if (status->flag & RX_FLAG_10MHZ)
227 		channel_flags |= IEEE80211_CHAN_HALF;
228 	else if (status->flag & RX_FLAG_5MHZ)
229 		channel_flags |= IEEE80211_CHAN_QUARTER;
230 
231 	if (status->band == IEEE80211_BAND_5GHZ)
232 		channel_flags |= IEEE80211_CHAN_OFDM | IEEE80211_CHAN_5GHZ;
233 	else if (status->flag & (RX_FLAG_HT | RX_FLAG_VHT))
234 		channel_flags |= IEEE80211_CHAN_DYN | IEEE80211_CHAN_2GHZ;
235 	else if (rate && rate->flags & IEEE80211_RATE_ERP_G)
236 		channel_flags |= IEEE80211_CHAN_OFDM | IEEE80211_CHAN_2GHZ;
237 	else if (rate)
238 		channel_flags |= IEEE80211_CHAN_OFDM | IEEE80211_CHAN_2GHZ;
239 	else
240 		channel_flags |= IEEE80211_CHAN_2GHZ;
241 	put_unaligned_le16(channel_flags, pos);
242 	pos += 2;
243 
244 	/* IEEE80211_RADIOTAP_DBM_ANTSIGNAL */
245 	if (local->hw.flags & IEEE80211_HW_SIGNAL_DBM &&
246 	    !(status->flag & RX_FLAG_NO_SIGNAL_VAL)) {
247 		*pos = status->signal;
248 		rthdr->it_present |=
249 			cpu_to_le32(1 << IEEE80211_RADIOTAP_DBM_ANTSIGNAL);
250 		pos++;
251 	}
252 
253 	/* IEEE80211_RADIOTAP_LOCK_QUALITY is missing */
254 
255 	if (!status->chains) {
256 		/* IEEE80211_RADIOTAP_ANTENNA */
257 		*pos = status->antenna;
258 		pos++;
259 	}
260 
261 	/* IEEE80211_RADIOTAP_DB_ANTNOISE is not used */
262 
263 	/* IEEE80211_RADIOTAP_RX_FLAGS */
264 	/* ensure 2 byte alignment for the 2 byte field as required */
265 	if ((pos - (u8 *)rthdr) & 1)
266 		*pos++ = 0;
267 	if (status->flag & RX_FLAG_FAILED_PLCP_CRC)
268 		rx_flags |= IEEE80211_RADIOTAP_F_RX_BADPLCP;
269 	put_unaligned_le16(rx_flags, pos);
270 	pos += 2;
271 
272 	if (status->flag & RX_FLAG_HT) {
273 		unsigned int stbc;
274 
275 		rthdr->it_present |= cpu_to_le32(1 << IEEE80211_RADIOTAP_MCS);
276 		*pos++ = local->hw.radiotap_mcs_details;
277 		*pos = 0;
278 		if (status->flag & RX_FLAG_SHORT_GI)
279 			*pos |= IEEE80211_RADIOTAP_MCS_SGI;
280 		if (status->flag & RX_FLAG_40MHZ)
281 			*pos |= IEEE80211_RADIOTAP_MCS_BW_40;
282 		if (status->flag & RX_FLAG_HT_GF)
283 			*pos |= IEEE80211_RADIOTAP_MCS_FMT_GF;
284 		if (status->flag & RX_FLAG_LDPC)
285 			*pos |= IEEE80211_RADIOTAP_MCS_FEC_LDPC;
286 		stbc = (status->flag & RX_FLAG_STBC_MASK) >> RX_FLAG_STBC_SHIFT;
287 		*pos |= stbc << IEEE80211_RADIOTAP_MCS_STBC_SHIFT;
288 		pos++;
289 		*pos++ = status->rate_idx;
290 	}
291 
292 	if (status->flag & RX_FLAG_AMPDU_DETAILS) {
293 		u16 flags = 0;
294 
295 		/* ensure 4 byte alignment */
296 		while ((pos - (u8 *)rthdr) & 3)
297 			pos++;
298 		rthdr->it_present |=
299 			cpu_to_le32(1 << IEEE80211_RADIOTAP_AMPDU_STATUS);
300 		put_unaligned_le32(status->ampdu_reference, pos);
301 		pos += 4;
302 		if (status->flag & RX_FLAG_AMPDU_REPORT_ZEROLEN)
303 			flags |= IEEE80211_RADIOTAP_AMPDU_REPORT_ZEROLEN;
304 		if (status->flag & RX_FLAG_AMPDU_IS_ZEROLEN)
305 			flags |= IEEE80211_RADIOTAP_AMPDU_IS_ZEROLEN;
306 		if (status->flag & RX_FLAG_AMPDU_LAST_KNOWN)
307 			flags |= IEEE80211_RADIOTAP_AMPDU_LAST_KNOWN;
308 		if (status->flag & RX_FLAG_AMPDU_IS_LAST)
309 			flags |= IEEE80211_RADIOTAP_AMPDU_IS_LAST;
310 		if (status->flag & RX_FLAG_AMPDU_DELIM_CRC_ERROR)
311 			flags |= IEEE80211_RADIOTAP_AMPDU_DELIM_CRC_ERR;
312 		if (status->flag & RX_FLAG_AMPDU_DELIM_CRC_KNOWN)
313 			flags |= IEEE80211_RADIOTAP_AMPDU_DELIM_CRC_KNOWN;
314 		put_unaligned_le16(flags, pos);
315 		pos += 2;
316 		if (status->flag & RX_FLAG_AMPDU_DELIM_CRC_KNOWN)
317 			*pos++ = status->ampdu_delimiter_crc;
318 		else
319 			*pos++ = 0;
320 		*pos++ = 0;
321 	}
322 
323 	if (status->flag & RX_FLAG_VHT) {
324 		u16 known = local->hw.radiotap_vht_details;
325 
326 		rthdr->it_present |= cpu_to_le32(1 << IEEE80211_RADIOTAP_VHT);
327 		/* known field - how to handle 80+80? */
328 		if (status->vht_flag & RX_VHT_FLAG_80P80MHZ)
329 			known &= ~IEEE80211_RADIOTAP_VHT_KNOWN_BANDWIDTH;
330 		put_unaligned_le16(known, pos);
331 		pos += 2;
332 		/* flags */
333 		if (status->flag & RX_FLAG_SHORT_GI)
334 			*pos |= IEEE80211_RADIOTAP_VHT_FLAG_SGI;
335 		/* in VHT, STBC is binary */
336 		if (status->flag & RX_FLAG_STBC_MASK)
337 			*pos |= IEEE80211_RADIOTAP_VHT_FLAG_STBC;
338 		if (status->vht_flag & RX_VHT_FLAG_BF)
339 			*pos |= IEEE80211_RADIOTAP_VHT_FLAG_BEAMFORMED;
340 		pos++;
341 		/* bandwidth */
342 		if (status->vht_flag & RX_VHT_FLAG_80MHZ)
343 			*pos++ = 4;
344 		else if (status->vht_flag & RX_VHT_FLAG_80P80MHZ)
345 			*pos++ = 0; /* marked not known above */
346 		else if (status->vht_flag & RX_VHT_FLAG_160MHZ)
347 			*pos++ = 11;
348 		else if (status->flag & RX_FLAG_40MHZ)
349 			*pos++ = 1;
350 		else /* 20 MHz */
351 			*pos++ = 0;
352 		/* MCS/NSS */
353 		*pos = (status->rate_idx << 4) | status->vht_nss;
354 		pos += 4;
355 		/* coding field */
356 		if (status->flag & RX_FLAG_LDPC)
357 			*pos |= IEEE80211_RADIOTAP_CODING_LDPC_USER0;
358 		pos++;
359 		/* group ID */
360 		pos++;
361 		/* partial_aid */
362 		pos += 2;
363 	}
364 
365 	for_each_set_bit(chain, &chains, IEEE80211_MAX_CHAINS) {
366 		*pos++ = status->chain_signal[chain];
367 		*pos++ = chain;
368 	}
369 }
370 
371 /*
372  * This function copies a received frame to all monitor interfaces and
373  * returns a cleaned-up SKB that no longer includes the FCS nor the
374  * radiotap header the driver might have added.
375  */
376 static struct sk_buff *
377 ieee80211_rx_monitor(struct ieee80211_local *local, struct sk_buff *origskb,
378 		     struct ieee80211_rate *rate)
379 {
380 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(origskb);
381 	struct ieee80211_sub_if_data *sdata;
382 	int needed_headroom;
383 	struct sk_buff *skb, *skb2;
384 	struct net_device *prev_dev = NULL;
385 	int present_fcs_len = 0;
386 
387 	/*
388 	 * First, we may need to make a copy of the skb because
389 	 *  (1) we need to modify it for radiotap (if not present), and
390 	 *  (2) the other RX handlers will modify the skb we got.
391 	 *
392 	 * We don't need to, of course, if we aren't going to return
393 	 * the SKB because it has a bad FCS/PLCP checksum.
394 	 */
395 
396 	if (local->hw.flags & IEEE80211_HW_RX_INCLUDES_FCS)
397 		present_fcs_len = FCS_LEN;
398 
399 	/* ensure hdr->frame_control is in skb head */
400 	if (!pskb_may_pull(origskb, 2)) {
401 		dev_kfree_skb(origskb);
402 		return NULL;
403 	}
404 
405 	if (!local->monitors) {
406 		if (should_drop_frame(origskb, present_fcs_len)) {
407 			dev_kfree_skb(origskb);
408 			return NULL;
409 		}
410 
411 		return remove_monitor_info(local, origskb);
412 	}
413 
414 	/* room for the radiotap header based on driver features */
415 	needed_headroom = ieee80211_rx_radiotap_space(local, status);
416 
417 	if (should_drop_frame(origskb, present_fcs_len)) {
418 		/* only need to expand headroom if necessary */
419 		skb = origskb;
420 		origskb = NULL;
421 
422 		/*
423 		 * This shouldn't trigger often because most devices have an
424 		 * RX header they pull before we get here, and that should
425 		 * be big enough for our radiotap information. We should
426 		 * probably export the length to drivers so that we can have
427 		 * them allocate enough headroom to start with.
428 		 */
429 		if (skb_headroom(skb) < needed_headroom &&
430 		    pskb_expand_head(skb, needed_headroom, 0, GFP_ATOMIC)) {
431 			dev_kfree_skb(skb);
432 			return NULL;
433 		}
434 	} else {
435 		/*
436 		 * Need to make a copy and possibly remove radiotap header
437 		 * and FCS from the original.
438 		 */
439 		skb = skb_copy_expand(origskb, needed_headroom, 0, GFP_ATOMIC);
440 
441 		origskb = remove_monitor_info(local, origskb);
442 
443 		if (!skb)
444 			return origskb;
445 	}
446 
447 	/* prepend radiotap information */
448 	ieee80211_add_rx_radiotap_header(local, skb, rate, needed_headroom,
449 					 true);
450 
451 	skb_reset_mac_header(skb);
452 	skb->ip_summed = CHECKSUM_UNNECESSARY;
453 	skb->pkt_type = PACKET_OTHERHOST;
454 	skb->protocol = htons(ETH_P_802_2);
455 
456 	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
457 		if (sdata->vif.type != NL80211_IFTYPE_MONITOR)
458 			continue;
459 
460 		if (sdata->u.mntr_flags & MONITOR_FLAG_COOK_FRAMES)
461 			continue;
462 
463 		if (!ieee80211_sdata_running(sdata))
464 			continue;
465 
466 		if (prev_dev) {
467 			skb2 = skb_clone(skb, GFP_ATOMIC);
468 			if (skb2) {
469 				skb2->dev = prev_dev;
470 				netif_receive_skb(skb2);
471 			}
472 		}
473 
474 		prev_dev = sdata->dev;
475 		sdata->dev->stats.rx_packets++;
476 		sdata->dev->stats.rx_bytes += skb->len;
477 	}
478 
479 	if (prev_dev) {
480 		skb->dev = prev_dev;
481 		netif_receive_skb(skb);
482 	} else
483 		dev_kfree_skb(skb);
484 
485 	return origskb;
486 }
487 
488 static void ieee80211_parse_qos(struct ieee80211_rx_data *rx)
489 {
490 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
491 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
492 	int tid, seqno_idx, security_idx;
493 
494 	/* does the frame have a qos control field? */
495 	if (ieee80211_is_data_qos(hdr->frame_control)) {
496 		u8 *qc = ieee80211_get_qos_ctl(hdr);
497 		/* frame has qos control */
498 		tid = *qc & IEEE80211_QOS_CTL_TID_MASK;
499 		if (*qc & IEEE80211_QOS_CTL_A_MSDU_PRESENT)
500 			status->rx_flags |= IEEE80211_RX_AMSDU;
501 
502 		seqno_idx = tid;
503 		security_idx = tid;
504 	} else {
505 		/*
506 		 * IEEE 802.11-2007, 7.1.3.4.1 ("Sequence Number field"):
507 		 *
508 		 *	Sequence numbers for management frames, QoS data
509 		 *	frames with a broadcast/multicast address in the
510 		 *	Address 1 field, and all non-QoS data frames sent
511 		 *	by QoS STAs are assigned using an additional single
512 		 *	modulo-4096 counter, [...]
513 		 *
514 		 * We also use that counter for non-QoS STAs.
515 		 */
516 		seqno_idx = IEEE80211_NUM_TIDS;
517 		security_idx = 0;
518 		if (ieee80211_is_mgmt(hdr->frame_control))
519 			security_idx = IEEE80211_NUM_TIDS;
520 		tid = 0;
521 	}
522 
523 	rx->seqno_idx = seqno_idx;
524 	rx->security_idx = security_idx;
525 	/* Set skb->priority to 1d tag if highest order bit of TID is not set.
526 	 * For now, set skb->priority to 0 for other cases. */
527 	rx->skb->priority = (tid > 7) ? 0 : tid;
528 }
529 
530 /**
531  * DOC: Packet alignment
532  *
533  * Drivers always need to pass packets that are aligned to two-byte boundaries
534  * to the stack.
535  *
536  * Additionally, should, if possible, align the payload data in a way that
537  * guarantees that the contained IP header is aligned to a four-byte
538  * boundary. In the case of regular frames, this simply means aligning the
539  * payload to a four-byte boundary (because either the IP header is directly
540  * contained, or IV/RFC1042 headers that have a length divisible by four are
541  * in front of it).  If the payload data is not properly aligned and the
542  * architecture doesn't support efficient unaligned operations, mac80211
543  * will align the data.
544  *
545  * With A-MSDU frames, however, the payload data address must yield two modulo
546  * four because there are 14-byte 802.3 headers within the A-MSDU frames that
547  * push the IP header further back to a multiple of four again. Thankfully, the
548  * specs were sane enough this time around to require padding each A-MSDU
549  * subframe to a length that is a multiple of four.
550  *
551  * Padding like Atheros hardware adds which is between the 802.11 header and
552  * the payload is not supported, the driver is required to move the 802.11
553  * header to be directly in front of the payload in that case.
554  */
555 static void ieee80211_verify_alignment(struct ieee80211_rx_data *rx)
556 {
557 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG
558 	WARN_ONCE((unsigned long)rx->skb->data & 1,
559 		  "unaligned packet at 0x%p\n", rx->skb->data);
560 #endif
561 }
562 
563 
564 /* rx handlers */
565 
566 static int ieee80211_is_unicast_robust_mgmt_frame(struct sk_buff *skb)
567 {
568 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
569 
570 	if (is_multicast_ether_addr(hdr->addr1))
571 		return 0;
572 
573 	return ieee80211_is_robust_mgmt_frame(skb);
574 }
575 
576 
577 static int ieee80211_is_multicast_robust_mgmt_frame(struct sk_buff *skb)
578 {
579 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
580 
581 	if (!is_multicast_ether_addr(hdr->addr1))
582 		return 0;
583 
584 	return ieee80211_is_robust_mgmt_frame(skb);
585 }
586 
587 
588 /* Get the BIP key index from MMIE; return -1 if this is not a BIP frame */
589 static int ieee80211_get_mmie_keyidx(struct sk_buff *skb)
590 {
591 	struct ieee80211_mgmt *hdr = (struct ieee80211_mgmt *) skb->data;
592 	struct ieee80211_mmie *mmie;
593 
594 	if (skb->len < 24 + sizeof(*mmie) || !is_multicast_ether_addr(hdr->da))
595 		return -1;
596 
597 	if (!ieee80211_is_robust_mgmt_frame(skb))
598 		return -1; /* not a robust management frame */
599 
600 	mmie = (struct ieee80211_mmie *)
601 		(skb->data + skb->len - sizeof(*mmie));
602 	if (mmie->element_id != WLAN_EID_MMIE ||
603 	    mmie->length != sizeof(*mmie) - 2)
604 		return -1;
605 
606 	return le16_to_cpu(mmie->key_id);
607 }
608 
609 static int iwl80211_get_cs_keyid(const struct ieee80211_cipher_scheme *cs,
610 				 struct sk_buff *skb)
611 {
612 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
613 	__le16 fc;
614 	int hdrlen;
615 	u8 keyid;
616 
617 	fc = hdr->frame_control;
618 	hdrlen = ieee80211_hdrlen(fc);
619 
620 	if (skb->len < hdrlen + cs->hdr_len)
621 		return -EINVAL;
622 
623 	skb_copy_bits(skb, hdrlen + cs->key_idx_off, &keyid, 1);
624 	keyid &= cs->key_idx_mask;
625 	keyid >>= cs->key_idx_shift;
626 
627 	return keyid;
628 }
629 
630 static ieee80211_rx_result ieee80211_rx_mesh_check(struct ieee80211_rx_data *rx)
631 {
632 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
633 	char *dev_addr = rx->sdata->vif.addr;
634 
635 	if (ieee80211_is_data(hdr->frame_control)) {
636 		if (is_multicast_ether_addr(hdr->addr1)) {
637 			if (ieee80211_has_tods(hdr->frame_control) ||
638 			    !ieee80211_has_fromds(hdr->frame_control))
639 				return RX_DROP_MONITOR;
640 			if (ether_addr_equal(hdr->addr3, dev_addr))
641 				return RX_DROP_MONITOR;
642 		} else {
643 			if (!ieee80211_has_a4(hdr->frame_control))
644 				return RX_DROP_MONITOR;
645 			if (ether_addr_equal(hdr->addr4, dev_addr))
646 				return RX_DROP_MONITOR;
647 		}
648 	}
649 
650 	/* If there is not an established peer link and this is not a peer link
651 	 * establisment frame, beacon or probe, drop the frame.
652 	 */
653 
654 	if (!rx->sta || sta_plink_state(rx->sta) != NL80211_PLINK_ESTAB) {
655 		struct ieee80211_mgmt *mgmt;
656 
657 		if (!ieee80211_is_mgmt(hdr->frame_control))
658 			return RX_DROP_MONITOR;
659 
660 		if (ieee80211_is_action(hdr->frame_control)) {
661 			u8 category;
662 
663 			/* make sure category field is present */
664 			if (rx->skb->len < IEEE80211_MIN_ACTION_SIZE)
665 				return RX_DROP_MONITOR;
666 
667 			mgmt = (struct ieee80211_mgmt *)hdr;
668 			category = mgmt->u.action.category;
669 			if (category != WLAN_CATEGORY_MESH_ACTION &&
670 			    category != WLAN_CATEGORY_SELF_PROTECTED)
671 				return RX_DROP_MONITOR;
672 			return RX_CONTINUE;
673 		}
674 
675 		if (ieee80211_is_probe_req(hdr->frame_control) ||
676 		    ieee80211_is_probe_resp(hdr->frame_control) ||
677 		    ieee80211_is_beacon(hdr->frame_control) ||
678 		    ieee80211_is_auth(hdr->frame_control))
679 			return RX_CONTINUE;
680 
681 		return RX_DROP_MONITOR;
682 	}
683 
684 	return RX_CONTINUE;
685 }
686 
687 static void ieee80211_release_reorder_frame(struct ieee80211_sub_if_data *sdata,
688 					    struct tid_ampdu_rx *tid_agg_rx,
689 					    int index,
690 					    struct sk_buff_head *frames)
691 {
692 	struct sk_buff_head *skb_list = &tid_agg_rx->reorder_buf[index];
693 	struct sk_buff *skb;
694 	struct ieee80211_rx_status *status;
695 
696 	lockdep_assert_held(&tid_agg_rx->reorder_lock);
697 
698 	if (skb_queue_empty(skb_list))
699 		goto no_frame;
700 
701 	if (!ieee80211_rx_reorder_ready(skb_list)) {
702 		__skb_queue_purge(skb_list);
703 		goto no_frame;
704 	}
705 
706 	/* release frames from the reorder ring buffer */
707 	tid_agg_rx->stored_mpdu_num--;
708 	while ((skb = __skb_dequeue(skb_list))) {
709 		status = IEEE80211_SKB_RXCB(skb);
710 		status->rx_flags |= IEEE80211_RX_DEFERRED_RELEASE;
711 		__skb_queue_tail(frames, skb);
712 	}
713 
714 no_frame:
715 	tid_agg_rx->head_seq_num = ieee80211_sn_inc(tid_agg_rx->head_seq_num);
716 }
717 
718 static void ieee80211_release_reorder_frames(struct ieee80211_sub_if_data *sdata,
719 					     struct tid_ampdu_rx *tid_agg_rx,
720 					     u16 head_seq_num,
721 					     struct sk_buff_head *frames)
722 {
723 	int index;
724 
725 	lockdep_assert_held(&tid_agg_rx->reorder_lock);
726 
727 	while (ieee80211_sn_less(tid_agg_rx->head_seq_num, head_seq_num)) {
728 		index = tid_agg_rx->head_seq_num % tid_agg_rx->buf_size;
729 		ieee80211_release_reorder_frame(sdata, tid_agg_rx, index,
730 						frames);
731 	}
732 }
733 
734 /*
735  * Timeout (in jiffies) for skb's that are waiting in the RX reorder buffer. If
736  * the skb was added to the buffer longer than this time ago, the earlier
737  * frames that have not yet been received are assumed to be lost and the skb
738  * can be released for processing. This may also release other skb's from the
739  * reorder buffer if there are no additional gaps between the frames.
740  *
741  * Callers must hold tid_agg_rx->reorder_lock.
742  */
743 #define HT_RX_REORDER_BUF_TIMEOUT (HZ / 10)
744 
745 static void ieee80211_sta_reorder_release(struct ieee80211_sub_if_data *sdata,
746 					  struct tid_ampdu_rx *tid_agg_rx,
747 					  struct sk_buff_head *frames)
748 {
749 	int index, i, j;
750 
751 	lockdep_assert_held(&tid_agg_rx->reorder_lock);
752 
753 	/* release the buffer until next missing frame */
754 	index = tid_agg_rx->head_seq_num % tid_agg_rx->buf_size;
755 	if (!ieee80211_rx_reorder_ready(&tid_agg_rx->reorder_buf[index]) &&
756 	    tid_agg_rx->stored_mpdu_num) {
757 		/*
758 		 * No buffers ready to be released, but check whether any
759 		 * frames in the reorder buffer have timed out.
760 		 */
761 		int skipped = 1;
762 		for (j = (index + 1) % tid_agg_rx->buf_size; j != index;
763 		     j = (j + 1) % tid_agg_rx->buf_size) {
764 			if (!ieee80211_rx_reorder_ready(
765 					&tid_agg_rx->reorder_buf[j])) {
766 				skipped++;
767 				continue;
768 			}
769 			if (skipped &&
770 			    !time_after(jiffies, tid_agg_rx->reorder_time[j] +
771 					HT_RX_REORDER_BUF_TIMEOUT))
772 				goto set_release_timer;
773 
774 			/* don't leave incomplete A-MSDUs around */
775 			for (i = (index + 1) % tid_agg_rx->buf_size; i != j;
776 			     i = (i + 1) % tid_agg_rx->buf_size)
777 				__skb_queue_purge(&tid_agg_rx->reorder_buf[i]);
778 
779 			ht_dbg_ratelimited(sdata,
780 					   "release an RX reorder frame due to timeout on earlier frames\n");
781 			ieee80211_release_reorder_frame(sdata, tid_agg_rx, j,
782 							frames);
783 
784 			/*
785 			 * Increment the head seq# also for the skipped slots.
786 			 */
787 			tid_agg_rx->head_seq_num =
788 				(tid_agg_rx->head_seq_num +
789 				 skipped) & IEEE80211_SN_MASK;
790 			skipped = 0;
791 		}
792 	} else while (ieee80211_rx_reorder_ready(
793 				&tid_agg_rx->reorder_buf[index])) {
794 		ieee80211_release_reorder_frame(sdata, tid_agg_rx, index,
795 						frames);
796 		index =	tid_agg_rx->head_seq_num % tid_agg_rx->buf_size;
797 	}
798 
799 	if (tid_agg_rx->stored_mpdu_num) {
800 		j = index = tid_agg_rx->head_seq_num % tid_agg_rx->buf_size;
801 
802 		for (; j != (index - 1) % tid_agg_rx->buf_size;
803 		     j = (j + 1) % tid_agg_rx->buf_size) {
804 			if (ieee80211_rx_reorder_ready(
805 					&tid_agg_rx->reorder_buf[j]))
806 				break;
807 		}
808 
809  set_release_timer:
810 
811 		mod_timer(&tid_agg_rx->reorder_timer,
812 			  tid_agg_rx->reorder_time[j] + 1 +
813 			  HT_RX_REORDER_BUF_TIMEOUT);
814 	} else {
815 		del_timer(&tid_agg_rx->reorder_timer);
816 	}
817 }
818 
819 /*
820  * As this function belongs to the RX path it must be under
821  * rcu_read_lock protection. It returns false if the frame
822  * can be processed immediately, true if it was consumed.
823  */
824 static bool ieee80211_sta_manage_reorder_buf(struct ieee80211_sub_if_data *sdata,
825 					     struct tid_ampdu_rx *tid_agg_rx,
826 					     struct sk_buff *skb,
827 					     struct sk_buff_head *frames)
828 {
829 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
830 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
831 	u16 sc = le16_to_cpu(hdr->seq_ctrl);
832 	u16 mpdu_seq_num = (sc & IEEE80211_SCTL_SEQ) >> 4;
833 	u16 head_seq_num, buf_size;
834 	int index;
835 	bool ret = true;
836 
837 	spin_lock(&tid_agg_rx->reorder_lock);
838 
839 	/*
840 	 * Offloaded BA sessions have no known starting sequence number so pick
841 	 * one from first Rxed frame for this tid after BA was started.
842 	 */
843 	if (unlikely(tid_agg_rx->auto_seq)) {
844 		tid_agg_rx->auto_seq = false;
845 		tid_agg_rx->ssn = mpdu_seq_num;
846 		tid_agg_rx->head_seq_num = mpdu_seq_num;
847 	}
848 
849 	buf_size = tid_agg_rx->buf_size;
850 	head_seq_num = tid_agg_rx->head_seq_num;
851 
852 	/* frame with out of date sequence number */
853 	if (ieee80211_sn_less(mpdu_seq_num, head_seq_num)) {
854 		dev_kfree_skb(skb);
855 		goto out;
856 	}
857 
858 	/*
859 	 * If frame the sequence number exceeds our buffering window
860 	 * size release some previous frames to make room for this one.
861 	 */
862 	if (!ieee80211_sn_less(mpdu_seq_num, head_seq_num + buf_size)) {
863 		head_seq_num = ieee80211_sn_inc(
864 				ieee80211_sn_sub(mpdu_seq_num, buf_size));
865 		/* release stored frames up to new head to stack */
866 		ieee80211_release_reorder_frames(sdata, tid_agg_rx,
867 						 head_seq_num, frames);
868 	}
869 
870 	/* Now the new frame is always in the range of the reordering buffer */
871 
872 	index = mpdu_seq_num % tid_agg_rx->buf_size;
873 
874 	/* check if we already stored this frame */
875 	if (ieee80211_rx_reorder_ready(&tid_agg_rx->reorder_buf[index])) {
876 		dev_kfree_skb(skb);
877 		goto out;
878 	}
879 
880 	/*
881 	 * If the current MPDU is in the right order and nothing else
882 	 * is stored we can process it directly, no need to buffer it.
883 	 * If it is first but there's something stored, we may be able
884 	 * to release frames after this one.
885 	 */
886 	if (mpdu_seq_num == tid_agg_rx->head_seq_num &&
887 	    tid_agg_rx->stored_mpdu_num == 0) {
888 		if (!(status->flag & RX_FLAG_AMSDU_MORE))
889 			tid_agg_rx->head_seq_num =
890 				ieee80211_sn_inc(tid_agg_rx->head_seq_num);
891 		ret = false;
892 		goto out;
893 	}
894 
895 	/* put the frame in the reordering buffer */
896 	__skb_queue_tail(&tid_agg_rx->reorder_buf[index], skb);
897 	if (!(status->flag & RX_FLAG_AMSDU_MORE)) {
898 		tid_agg_rx->reorder_time[index] = jiffies;
899 		tid_agg_rx->stored_mpdu_num++;
900 		ieee80211_sta_reorder_release(sdata, tid_agg_rx, frames);
901 	}
902 
903  out:
904 	spin_unlock(&tid_agg_rx->reorder_lock);
905 	return ret;
906 }
907 
908 /*
909  * Reorder MPDUs from A-MPDUs, keeping them on a buffer. Returns
910  * true if the MPDU was buffered, false if it should be processed.
911  */
912 static void ieee80211_rx_reorder_ampdu(struct ieee80211_rx_data *rx,
913 				       struct sk_buff_head *frames)
914 {
915 	struct sk_buff *skb = rx->skb;
916 	struct ieee80211_local *local = rx->local;
917 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
918 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
919 	struct sta_info *sta = rx->sta;
920 	struct tid_ampdu_rx *tid_agg_rx;
921 	u16 sc;
922 	u8 tid, ack_policy;
923 
924 	if (!ieee80211_is_data_qos(hdr->frame_control) ||
925 	    is_multicast_ether_addr(hdr->addr1))
926 		goto dont_reorder;
927 
928 	/*
929 	 * filter the QoS data rx stream according to
930 	 * STA/TID and check if this STA/TID is on aggregation
931 	 */
932 
933 	if (!sta)
934 		goto dont_reorder;
935 
936 	ack_policy = *ieee80211_get_qos_ctl(hdr) &
937 		     IEEE80211_QOS_CTL_ACK_POLICY_MASK;
938 	tid = *ieee80211_get_qos_ctl(hdr) & IEEE80211_QOS_CTL_TID_MASK;
939 
940 	tid_agg_rx = rcu_dereference(sta->ampdu_mlme.tid_rx[tid]);
941 	if (!tid_agg_rx)
942 		goto dont_reorder;
943 
944 	/* qos null data frames are excluded */
945 	if (unlikely(hdr->frame_control & cpu_to_le16(IEEE80211_STYPE_NULLFUNC)))
946 		goto dont_reorder;
947 
948 	/* not part of a BA session */
949 	if (ack_policy != IEEE80211_QOS_CTL_ACK_POLICY_BLOCKACK &&
950 	    ack_policy != IEEE80211_QOS_CTL_ACK_POLICY_NORMAL)
951 		goto dont_reorder;
952 
953 	/* not actually part of this BA session */
954 	if (!(status->rx_flags & IEEE80211_RX_RA_MATCH))
955 		goto dont_reorder;
956 
957 	/* new, potentially un-ordered, ampdu frame - process it */
958 
959 	/* reset session timer */
960 	if (tid_agg_rx->timeout)
961 		tid_agg_rx->last_rx = jiffies;
962 
963 	/* if this mpdu is fragmented - terminate rx aggregation session */
964 	sc = le16_to_cpu(hdr->seq_ctrl);
965 	if (sc & IEEE80211_SCTL_FRAG) {
966 		skb->pkt_type = IEEE80211_SDATA_QUEUE_TYPE_FRAME;
967 		skb_queue_tail(&rx->sdata->skb_queue, skb);
968 		ieee80211_queue_work(&local->hw, &rx->sdata->work);
969 		return;
970 	}
971 
972 	/*
973 	 * No locking needed -- we will only ever process one
974 	 * RX packet at a time, and thus own tid_agg_rx. All
975 	 * other code manipulating it needs to (and does) make
976 	 * sure that we cannot get to it any more before doing
977 	 * anything with it.
978 	 */
979 	if (ieee80211_sta_manage_reorder_buf(rx->sdata, tid_agg_rx, skb,
980 					     frames))
981 		return;
982 
983  dont_reorder:
984 	__skb_queue_tail(frames, skb);
985 }
986 
987 static ieee80211_rx_result debug_noinline
988 ieee80211_rx_h_check(struct ieee80211_rx_data *rx)
989 {
990 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
991 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
992 
993 	/*
994 	 * Drop duplicate 802.11 retransmissions
995 	 * (IEEE 802.11-2012: 9.3.2.10 "Duplicate detection and recovery")
996 	 */
997 	if (rx->skb->len >= 24 && rx->sta &&
998 	    !ieee80211_is_ctl(hdr->frame_control) &&
999 	    !ieee80211_is_qos_nullfunc(hdr->frame_control) &&
1000 	    !is_multicast_ether_addr(hdr->addr1)) {
1001 		if (unlikely(ieee80211_has_retry(hdr->frame_control) &&
1002 			     rx->sta->last_seq_ctrl[rx->seqno_idx] ==
1003 			     hdr->seq_ctrl)) {
1004 			if (status->rx_flags & IEEE80211_RX_RA_MATCH) {
1005 				rx->local->dot11FrameDuplicateCount++;
1006 				rx->sta->num_duplicates++;
1007 			}
1008 			return RX_DROP_UNUSABLE;
1009 		} else if (!(status->flag & RX_FLAG_AMSDU_MORE)) {
1010 			rx->sta->last_seq_ctrl[rx->seqno_idx] = hdr->seq_ctrl;
1011 		}
1012 	}
1013 
1014 	if (unlikely(rx->skb->len < 16)) {
1015 		I802_DEBUG_INC(rx->local->rx_handlers_drop_short);
1016 		return RX_DROP_MONITOR;
1017 	}
1018 
1019 	/* Drop disallowed frame classes based on STA auth/assoc state;
1020 	 * IEEE 802.11, Chap 5.5.
1021 	 *
1022 	 * mac80211 filters only based on association state, i.e. it drops
1023 	 * Class 3 frames from not associated stations. hostapd sends
1024 	 * deauth/disassoc frames when needed. In addition, hostapd is
1025 	 * responsible for filtering on both auth and assoc states.
1026 	 */
1027 
1028 	if (ieee80211_vif_is_mesh(&rx->sdata->vif))
1029 		return ieee80211_rx_mesh_check(rx);
1030 
1031 	if (unlikely((ieee80211_is_data(hdr->frame_control) ||
1032 		      ieee80211_is_pspoll(hdr->frame_control)) &&
1033 		     rx->sdata->vif.type != NL80211_IFTYPE_ADHOC &&
1034 		     rx->sdata->vif.type != NL80211_IFTYPE_WDS &&
1035 		     (!rx->sta || !test_sta_flag(rx->sta, WLAN_STA_ASSOC)))) {
1036 		/*
1037 		 * accept port control frames from the AP even when it's not
1038 		 * yet marked ASSOC to prevent a race where we don't set the
1039 		 * assoc bit quickly enough before it sends the first frame
1040 		 */
1041 		if (rx->sta && rx->sdata->vif.type == NL80211_IFTYPE_STATION &&
1042 		    ieee80211_is_data_present(hdr->frame_control)) {
1043 			unsigned int hdrlen;
1044 			__be16 ethertype;
1045 
1046 			hdrlen = ieee80211_hdrlen(hdr->frame_control);
1047 
1048 			if (rx->skb->len < hdrlen + 8)
1049 				return RX_DROP_MONITOR;
1050 
1051 			skb_copy_bits(rx->skb, hdrlen + 6, &ethertype, 2);
1052 			if (ethertype == rx->sdata->control_port_protocol)
1053 				return RX_CONTINUE;
1054 		}
1055 
1056 		if (rx->sdata->vif.type == NL80211_IFTYPE_AP &&
1057 		    cfg80211_rx_spurious_frame(rx->sdata->dev,
1058 					       hdr->addr2,
1059 					       GFP_ATOMIC))
1060 			return RX_DROP_UNUSABLE;
1061 
1062 		return RX_DROP_MONITOR;
1063 	}
1064 
1065 	return RX_CONTINUE;
1066 }
1067 
1068 
1069 static ieee80211_rx_result debug_noinline
1070 ieee80211_rx_h_check_more_data(struct ieee80211_rx_data *rx)
1071 {
1072 	struct ieee80211_local *local;
1073 	struct ieee80211_hdr *hdr;
1074 	struct sk_buff *skb;
1075 
1076 	local = rx->local;
1077 	skb = rx->skb;
1078 	hdr = (struct ieee80211_hdr *) skb->data;
1079 
1080 	if (!local->pspolling)
1081 		return RX_CONTINUE;
1082 
1083 	if (!ieee80211_has_fromds(hdr->frame_control))
1084 		/* this is not from AP */
1085 		return RX_CONTINUE;
1086 
1087 	if (!ieee80211_is_data(hdr->frame_control))
1088 		return RX_CONTINUE;
1089 
1090 	if (!ieee80211_has_moredata(hdr->frame_control)) {
1091 		/* AP has no more frames buffered for us */
1092 		local->pspolling = false;
1093 		return RX_CONTINUE;
1094 	}
1095 
1096 	/* more data bit is set, let's request a new frame from the AP */
1097 	ieee80211_send_pspoll(local, rx->sdata);
1098 
1099 	return RX_CONTINUE;
1100 }
1101 
1102 static void sta_ps_start(struct sta_info *sta)
1103 {
1104 	struct ieee80211_sub_if_data *sdata = sta->sdata;
1105 	struct ieee80211_local *local = sdata->local;
1106 	struct ps_data *ps;
1107 
1108 	if (sta->sdata->vif.type == NL80211_IFTYPE_AP ||
1109 	    sta->sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
1110 		ps = &sdata->bss->ps;
1111 	else
1112 		return;
1113 
1114 	atomic_inc(&ps->num_sta_ps);
1115 	set_sta_flag(sta, WLAN_STA_PS_STA);
1116 	if (!(local->hw.flags & IEEE80211_HW_AP_LINK_PS))
1117 		drv_sta_notify(local, sdata, STA_NOTIFY_SLEEP, &sta->sta);
1118 	ps_dbg(sdata, "STA %pM aid %d enters power save mode\n",
1119 	       sta->sta.addr, sta->sta.aid);
1120 }
1121 
1122 static void sta_ps_end(struct sta_info *sta)
1123 {
1124 	ps_dbg(sta->sdata, "STA %pM aid %d exits power save mode\n",
1125 	       sta->sta.addr, sta->sta.aid);
1126 
1127 	if (test_sta_flag(sta, WLAN_STA_PS_DRIVER)) {
1128 		/*
1129 		 * Clear the flag only if the other one is still set
1130 		 * so that the TX path won't start TX'ing new frames
1131 		 * directly ... In the case that the driver flag isn't
1132 		 * set ieee80211_sta_ps_deliver_wakeup() will clear it.
1133 		 */
1134 		clear_sta_flag(sta, WLAN_STA_PS_STA);
1135 		ps_dbg(sta->sdata, "STA %pM aid %d driver-ps-blocked\n",
1136 		       sta->sta.addr, sta->sta.aid);
1137 		return;
1138 	}
1139 
1140 	set_sta_flag(sta, WLAN_STA_PS_DELIVER);
1141 	clear_sta_flag(sta, WLAN_STA_PS_STA);
1142 	ieee80211_sta_ps_deliver_wakeup(sta);
1143 }
1144 
1145 int ieee80211_sta_ps_transition(struct ieee80211_sta *sta, bool start)
1146 {
1147 	struct sta_info *sta_inf = container_of(sta, struct sta_info, sta);
1148 	bool in_ps;
1149 
1150 	WARN_ON(!(sta_inf->local->hw.flags & IEEE80211_HW_AP_LINK_PS));
1151 
1152 	/* Don't let the same PS state be set twice */
1153 	in_ps = test_sta_flag(sta_inf, WLAN_STA_PS_STA);
1154 	if ((start && in_ps) || (!start && !in_ps))
1155 		return -EINVAL;
1156 
1157 	if (start)
1158 		sta_ps_start(sta_inf);
1159 	else
1160 		sta_ps_end(sta_inf);
1161 
1162 	return 0;
1163 }
1164 EXPORT_SYMBOL(ieee80211_sta_ps_transition);
1165 
1166 static ieee80211_rx_result debug_noinline
1167 ieee80211_rx_h_uapsd_and_pspoll(struct ieee80211_rx_data *rx)
1168 {
1169 	struct ieee80211_sub_if_data *sdata = rx->sdata;
1170 	struct ieee80211_hdr *hdr = (void *)rx->skb->data;
1171 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
1172 	int tid, ac;
1173 
1174 	if (!rx->sta || !(status->rx_flags & IEEE80211_RX_RA_MATCH))
1175 		return RX_CONTINUE;
1176 
1177 	if (sdata->vif.type != NL80211_IFTYPE_AP &&
1178 	    sdata->vif.type != NL80211_IFTYPE_AP_VLAN)
1179 		return RX_CONTINUE;
1180 
1181 	/*
1182 	 * The device handles station powersave, so don't do anything about
1183 	 * uAPSD and PS-Poll frames (the latter shouldn't even come up from
1184 	 * it to mac80211 since they're handled.)
1185 	 */
1186 	if (sdata->local->hw.flags & IEEE80211_HW_AP_LINK_PS)
1187 		return RX_CONTINUE;
1188 
1189 	/*
1190 	 * Don't do anything if the station isn't already asleep. In
1191 	 * the uAPSD case, the station will probably be marked asleep,
1192 	 * in the PS-Poll case the station must be confused ...
1193 	 */
1194 	if (!test_sta_flag(rx->sta, WLAN_STA_PS_STA))
1195 		return RX_CONTINUE;
1196 
1197 	if (unlikely(ieee80211_is_pspoll(hdr->frame_control))) {
1198 		if (!test_sta_flag(rx->sta, WLAN_STA_SP)) {
1199 			if (!test_sta_flag(rx->sta, WLAN_STA_PS_DRIVER))
1200 				ieee80211_sta_ps_deliver_poll_response(rx->sta);
1201 			else
1202 				set_sta_flag(rx->sta, WLAN_STA_PSPOLL);
1203 		}
1204 
1205 		/* Free PS Poll skb here instead of returning RX_DROP that would
1206 		 * count as an dropped frame. */
1207 		dev_kfree_skb(rx->skb);
1208 
1209 		return RX_QUEUED;
1210 	} else if (!ieee80211_has_morefrags(hdr->frame_control) &&
1211 		   !(status->rx_flags & IEEE80211_RX_DEFERRED_RELEASE) &&
1212 		   ieee80211_has_pm(hdr->frame_control) &&
1213 		   (ieee80211_is_data_qos(hdr->frame_control) ||
1214 		    ieee80211_is_qos_nullfunc(hdr->frame_control))) {
1215 		tid = *ieee80211_get_qos_ctl(hdr) & IEEE80211_QOS_CTL_TID_MASK;
1216 		ac = ieee802_1d_to_ac[tid & 7];
1217 
1218 		/*
1219 		 * If this AC is not trigger-enabled do nothing.
1220 		 *
1221 		 * NB: This could/should check a separate bitmap of trigger-
1222 		 * enabled queues, but for now we only implement uAPSD w/o
1223 		 * TSPEC changes to the ACs, so they're always the same.
1224 		 */
1225 		if (!(rx->sta->sta.uapsd_queues & BIT(ac)))
1226 			return RX_CONTINUE;
1227 
1228 		/* if we are in a service period, do nothing */
1229 		if (test_sta_flag(rx->sta, WLAN_STA_SP))
1230 			return RX_CONTINUE;
1231 
1232 		if (!test_sta_flag(rx->sta, WLAN_STA_PS_DRIVER))
1233 			ieee80211_sta_ps_deliver_uapsd(rx->sta);
1234 		else
1235 			set_sta_flag(rx->sta, WLAN_STA_UAPSD);
1236 	}
1237 
1238 	return RX_CONTINUE;
1239 }
1240 
1241 static ieee80211_rx_result debug_noinline
1242 ieee80211_rx_h_sta_process(struct ieee80211_rx_data *rx)
1243 {
1244 	struct sta_info *sta = rx->sta;
1245 	struct sk_buff *skb = rx->skb;
1246 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
1247 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
1248 	int i;
1249 
1250 	if (!sta)
1251 		return RX_CONTINUE;
1252 
1253 	/*
1254 	 * Update last_rx only for IBSS packets which are for the current
1255 	 * BSSID and for station already AUTHORIZED to avoid keeping the
1256 	 * current IBSS network alive in cases where other STAs start
1257 	 * using different BSSID. This will also give the station another
1258 	 * chance to restart the authentication/authorization in case
1259 	 * something went wrong the first time.
1260 	 */
1261 	if (rx->sdata->vif.type == NL80211_IFTYPE_ADHOC) {
1262 		u8 *bssid = ieee80211_get_bssid(hdr, rx->skb->len,
1263 						NL80211_IFTYPE_ADHOC);
1264 		if (ether_addr_equal(bssid, rx->sdata->u.ibss.bssid) &&
1265 		    test_sta_flag(sta, WLAN_STA_AUTHORIZED)) {
1266 			sta->last_rx = jiffies;
1267 			if (ieee80211_is_data(hdr->frame_control) &&
1268 			    !is_multicast_ether_addr(hdr->addr1)) {
1269 				sta->last_rx_rate_idx = status->rate_idx;
1270 				sta->last_rx_rate_flag = status->flag;
1271 				sta->last_rx_rate_vht_flag = status->vht_flag;
1272 				sta->last_rx_rate_vht_nss = status->vht_nss;
1273 			}
1274 		}
1275 	} else if (!is_multicast_ether_addr(hdr->addr1)) {
1276 		/*
1277 		 * Mesh beacons will update last_rx when if they are found to
1278 		 * match the current local configuration when processed.
1279 		 */
1280 		sta->last_rx = jiffies;
1281 		if (ieee80211_is_data(hdr->frame_control)) {
1282 			sta->last_rx_rate_idx = status->rate_idx;
1283 			sta->last_rx_rate_flag = status->flag;
1284 			sta->last_rx_rate_vht_flag = status->vht_flag;
1285 			sta->last_rx_rate_vht_nss = status->vht_nss;
1286 		}
1287 	}
1288 
1289 	if (!(status->rx_flags & IEEE80211_RX_RA_MATCH))
1290 		return RX_CONTINUE;
1291 
1292 	if (rx->sdata->vif.type == NL80211_IFTYPE_STATION)
1293 		ieee80211_sta_rx_notify(rx->sdata, hdr);
1294 
1295 	sta->rx_fragments++;
1296 	sta->rx_bytes += rx->skb->len;
1297 	if (!(status->flag & RX_FLAG_NO_SIGNAL_VAL)) {
1298 		sta->last_signal = status->signal;
1299 		ewma_add(&sta->avg_signal, -status->signal);
1300 	}
1301 
1302 	if (status->chains) {
1303 		sta->chains = status->chains;
1304 		for (i = 0; i < ARRAY_SIZE(status->chain_signal); i++) {
1305 			int signal = status->chain_signal[i];
1306 
1307 			if (!(status->chains & BIT(i)))
1308 				continue;
1309 
1310 			sta->chain_signal_last[i] = signal;
1311 			ewma_add(&sta->chain_signal_avg[i], -signal);
1312 		}
1313 	}
1314 
1315 	/*
1316 	 * Change STA power saving mode only at the end of a frame
1317 	 * exchange sequence.
1318 	 */
1319 	if (!(sta->local->hw.flags & IEEE80211_HW_AP_LINK_PS) &&
1320 	    !ieee80211_has_morefrags(hdr->frame_control) &&
1321 	    !(status->rx_flags & IEEE80211_RX_DEFERRED_RELEASE) &&
1322 	    (rx->sdata->vif.type == NL80211_IFTYPE_AP ||
1323 	     rx->sdata->vif.type == NL80211_IFTYPE_AP_VLAN) &&
1324 	    /* PM bit is only checked in frames where it isn't reserved,
1325 	     * in AP mode it's reserved in non-bufferable management frames
1326 	     * (cf. IEEE 802.11-2012 8.2.4.1.7 Power Management field)
1327 	     */
1328 	    (!ieee80211_is_mgmt(hdr->frame_control) ||
1329 	     ieee80211_is_bufferable_mmpdu(hdr->frame_control))) {
1330 		if (test_sta_flag(sta, WLAN_STA_PS_STA)) {
1331 			if (!ieee80211_has_pm(hdr->frame_control))
1332 				sta_ps_end(sta);
1333 		} else {
1334 			if (ieee80211_has_pm(hdr->frame_control))
1335 				sta_ps_start(sta);
1336 		}
1337 	}
1338 
1339 	/* mesh power save support */
1340 	if (ieee80211_vif_is_mesh(&rx->sdata->vif))
1341 		ieee80211_mps_rx_h_sta_process(sta, hdr);
1342 
1343 	/*
1344 	 * Drop (qos-)data::nullfunc frames silently, since they
1345 	 * are used only to control station power saving mode.
1346 	 */
1347 	if (ieee80211_is_nullfunc(hdr->frame_control) ||
1348 	    ieee80211_is_qos_nullfunc(hdr->frame_control)) {
1349 		I802_DEBUG_INC(rx->local->rx_handlers_drop_nullfunc);
1350 
1351 		/*
1352 		 * If we receive a 4-addr nullfunc frame from a STA
1353 		 * that was not moved to a 4-addr STA vlan yet send
1354 		 * the event to userspace and for older hostapd drop
1355 		 * the frame to the monitor interface.
1356 		 */
1357 		if (ieee80211_has_a4(hdr->frame_control) &&
1358 		    (rx->sdata->vif.type == NL80211_IFTYPE_AP ||
1359 		     (rx->sdata->vif.type == NL80211_IFTYPE_AP_VLAN &&
1360 		      !rx->sdata->u.vlan.sta))) {
1361 			if (!test_and_set_sta_flag(sta, WLAN_STA_4ADDR_EVENT))
1362 				cfg80211_rx_unexpected_4addr_frame(
1363 					rx->sdata->dev, sta->sta.addr,
1364 					GFP_ATOMIC);
1365 			return RX_DROP_MONITOR;
1366 		}
1367 		/*
1368 		 * Update counter and free packet here to avoid
1369 		 * counting this as a dropped packed.
1370 		 */
1371 		sta->rx_packets++;
1372 		dev_kfree_skb(rx->skb);
1373 		return RX_QUEUED;
1374 	}
1375 
1376 	return RX_CONTINUE;
1377 } /* ieee80211_rx_h_sta_process */
1378 
1379 static ieee80211_rx_result debug_noinline
1380 ieee80211_rx_h_decrypt(struct ieee80211_rx_data *rx)
1381 {
1382 	struct sk_buff *skb = rx->skb;
1383 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
1384 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
1385 	int keyidx;
1386 	int hdrlen;
1387 	ieee80211_rx_result result = RX_DROP_UNUSABLE;
1388 	struct ieee80211_key *sta_ptk = NULL;
1389 	int mmie_keyidx = -1;
1390 	__le16 fc;
1391 	const struct ieee80211_cipher_scheme *cs = NULL;
1392 
1393 	/*
1394 	 * Key selection 101
1395 	 *
1396 	 * There are four types of keys:
1397 	 *  - GTK (group keys)
1398 	 *  - IGTK (group keys for management frames)
1399 	 *  - PTK (pairwise keys)
1400 	 *  - STK (station-to-station pairwise keys)
1401 	 *
1402 	 * When selecting a key, we have to distinguish between multicast
1403 	 * (including broadcast) and unicast frames, the latter can only
1404 	 * use PTKs and STKs while the former always use GTKs and IGTKs.
1405 	 * Unless, of course, actual WEP keys ("pre-RSNA") are used, then
1406 	 * unicast frames can also use key indices like GTKs. Hence, if we
1407 	 * don't have a PTK/STK we check the key index for a WEP key.
1408 	 *
1409 	 * Note that in a regular BSS, multicast frames are sent by the
1410 	 * AP only, associated stations unicast the frame to the AP first
1411 	 * which then multicasts it on their behalf.
1412 	 *
1413 	 * There is also a slight problem in IBSS mode: GTKs are negotiated
1414 	 * with each station, that is something we don't currently handle.
1415 	 * The spec seems to expect that one negotiates the same key with
1416 	 * every station but there's no such requirement; VLANs could be
1417 	 * possible.
1418 	 */
1419 
1420 	/*
1421 	 * No point in finding a key and decrypting if the frame is neither
1422 	 * addressed to us nor a multicast frame.
1423 	 */
1424 	if (!(status->rx_flags & IEEE80211_RX_RA_MATCH))
1425 		return RX_CONTINUE;
1426 
1427 	/* start without a key */
1428 	rx->key = NULL;
1429 	fc = hdr->frame_control;
1430 
1431 	if (rx->sta) {
1432 		int keyid = rx->sta->ptk_idx;
1433 
1434 		if (ieee80211_has_protected(fc) && rx->sta->cipher_scheme) {
1435 			cs = rx->sta->cipher_scheme;
1436 			keyid = iwl80211_get_cs_keyid(cs, rx->skb);
1437 			if (unlikely(keyid < 0))
1438 				return RX_DROP_UNUSABLE;
1439 		}
1440 		sta_ptk = rcu_dereference(rx->sta->ptk[keyid]);
1441 	}
1442 
1443 	if (!ieee80211_has_protected(fc))
1444 		mmie_keyidx = ieee80211_get_mmie_keyidx(rx->skb);
1445 
1446 	if (!is_multicast_ether_addr(hdr->addr1) && sta_ptk) {
1447 		rx->key = sta_ptk;
1448 		if ((status->flag & RX_FLAG_DECRYPTED) &&
1449 		    (status->flag & RX_FLAG_IV_STRIPPED))
1450 			return RX_CONTINUE;
1451 		/* Skip decryption if the frame is not protected. */
1452 		if (!ieee80211_has_protected(fc))
1453 			return RX_CONTINUE;
1454 	} else if (mmie_keyidx >= 0) {
1455 		/* Broadcast/multicast robust management frame / BIP */
1456 		if ((status->flag & RX_FLAG_DECRYPTED) &&
1457 		    (status->flag & RX_FLAG_IV_STRIPPED))
1458 			return RX_CONTINUE;
1459 
1460 		if (mmie_keyidx < NUM_DEFAULT_KEYS ||
1461 		    mmie_keyidx >= NUM_DEFAULT_KEYS + NUM_DEFAULT_MGMT_KEYS)
1462 			return RX_DROP_MONITOR; /* unexpected BIP keyidx */
1463 		if (rx->sta)
1464 			rx->key = rcu_dereference(rx->sta->gtk[mmie_keyidx]);
1465 		if (!rx->key)
1466 			rx->key = rcu_dereference(rx->sdata->keys[mmie_keyidx]);
1467 	} else if (!ieee80211_has_protected(fc)) {
1468 		/*
1469 		 * The frame was not protected, so skip decryption. However, we
1470 		 * need to set rx->key if there is a key that could have been
1471 		 * used so that the frame may be dropped if encryption would
1472 		 * have been expected.
1473 		 */
1474 		struct ieee80211_key *key = NULL;
1475 		struct ieee80211_sub_if_data *sdata = rx->sdata;
1476 		int i;
1477 
1478 		if (ieee80211_is_mgmt(fc) &&
1479 		    is_multicast_ether_addr(hdr->addr1) &&
1480 		    (key = rcu_dereference(rx->sdata->default_mgmt_key)))
1481 			rx->key = key;
1482 		else {
1483 			if (rx->sta) {
1484 				for (i = 0; i < NUM_DEFAULT_KEYS; i++) {
1485 					key = rcu_dereference(rx->sta->gtk[i]);
1486 					if (key)
1487 						break;
1488 				}
1489 			}
1490 			if (!key) {
1491 				for (i = 0; i < NUM_DEFAULT_KEYS; i++) {
1492 					key = rcu_dereference(sdata->keys[i]);
1493 					if (key)
1494 						break;
1495 				}
1496 			}
1497 			if (key)
1498 				rx->key = key;
1499 		}
1500 		return RX_CONTINUE;
1501 	} else {
1502 		u8 keyid;
1503 
1504 		/*
1505 		 * The device doesn't give us the IV so we won't be
1506 		 * able to look up the key. That's ok though, we
1507 		 * don't need to decrypt the frame, we just won't
1508 		 * be able to keep statistics accurate.
1509 		 * Except for key threshold notifications, should
1510 		 * we somehow allow the driver to tell us which key
1511 		 * the hardware used if this flag is set?
1512 		 */
1513 		if ((status->flag & RX_FLAG_DECRYPTED) &&
1514 		    (status->flag & RX_FLAG_IV_STRIPPED))
1515 			return RX_CONTINUE;
1516 
1517 		hdrlen = ieee80211_hdrlen(fc);
1518 
1519 		if (cs) {
1520 			keyidx = iwl80211_get_cs_keyid(cs, rx->skb);
1521 
1522 			if (unlikely(keyidx < 0))
1523 				return RX_DROP_UNUSABLE;
1524 		} else {
1525 			if (rx->skb->len < 8 + hdrlen)
1526 				return RX_DROP_UNUSABLE; /* TODO: count this? */
1527 			/*
1528 			 * no need to call ieee80211_wep_get_keyidx,
1529 			 * it verifies a bunch of things we've done already
1530 			 */
1531 			skb_copy_bits(rx->skb, hdrlen + 3, &keyid, 1);
1532 			keyidx = keyid >> 6;
1533 		}
1534 
1535 		/* check per-station GTK first, if multicast packet */
1536 		if (is_multicast_ether_addr(hdr->addr1) && rx->sta)
1537 			rx->key = rcu_dereference(rx->sta->gtk[keyidx]);
1538 
1539 		/* if not found, try default key */
1540 		if (!rx->key) {
1541 			rx->key = rcu_dereference(rx->sdata->keys[keyidx]);
1542 
1543 			/*
1544 			 * RSNA-protected unicast frames should always be
1545 			 * sent with pairwise or station-to-station keys,
1546 			 * but for WEP we allow using a key index as well.
1547 			 */
1548 			if (rx->key &&
1549 			    rx->key->conf.cipher != WLAN_CIPHER_SUITE_WEP40 &&
1550 			    rx->key->conf.cipher != WLAN_CIPHER_SUITE_WEP104 &&
1551 			    !is_multicast_ether_addr(hdr->addr1))
1552 				rx->key = NULL;
1553 		}
1554 	}
1555 
1556 	if (rx->key) {
1557 		if (unlikely(rx->key->flags & KEY_FLAG_TAINTED))
1558 			return RX_DROP_MONITOR;
1559 
1560 		rx->key->tx_rx_count++;
1561 		/* TODO: add threshold stuff again */
1562 	} else {
1563 		return RX_DROP_MONITOR;
1564 	}
1565 
1566 	switch (rx->key->conf.cipher) {
1567 	case WLAN_CIPHER_SUITE_WEP40:
1568 	case WLAN_CIPHER_SUITE_WEP104:
1569 		result = ieee80211_crypto_wep_decrypt(rx);
1570 		break;
1571 	case WLAN_CIPHER_SUITE_TKIP:
1572 		result = ieee80211_crypto_tkip_decrypt(rx);
1573 		break;
1574 	case WLAN_CIPHER_SUITE_CCMP:
1575 		result = ieee80211_crypto_ccmp_decrypt(rx);
1576 		break;
1577 	case WLAN_CIPHER_SUITE_AES_CMAC:
1578 		result = ieee80211_crypto_aes_cmac_decrypt(rx);
1579 		break;
1580 	default:
1581 		result = ieee80211_crypto_hw_decrypt(rx);
1582 	}
1583 
1584 	/* the hdr variable is invalid after the decrypt handlers */
1585 
1586 	/* either the frame has been decrypted or will be dropped */
1587 	status->flag |= RX_FLAG_DECRYPTED;
1588 
1589 	return result;
1590 }
1591 
1592 static inline struct ieee80211_fragment_entry *
1593 ieee80211_reassemble_add(struct ieee80211_sub_if_data *sdata,
1594 			 unsigned int frag, unsigned int seq, int rx_queue,
1595 			 struct sk_buff **skb)
1596 {
1597 	struct ieee80211_fragment_entry *entry;
1598 
1599 	entry = &sdata->fragments[sdata->fragment_next++];
1600 	if (sdata->fragment_next >= IEEE80211_FRAGMENT_MAX)
1601 		sdata->fragment_next = 0;
1602 
1603 	if (!skb_queue_empty(&entry->skb_list))
1604 		__skb_queue_purge(&entry->skb_list);
1605 
1606 	__skb_queue_tail(&entry->skb_list, *skb); /* no need for locking */
1607 	*skb = NULL;
1608 	entry->first_frag_time = jiffies;
1609 	entry->seq = seq;
1610 	entry->rx_queue = rx_queue;
1611 	entry->last_frag = frag;
1612 	entry->ccmp = 0;
1613 	entry->extra_len = 0;
1614 
1615 	return entry;
1616 }
1617 
1618 static inline struct ieee80211_fragment_entry *
1619 ieee80211_reassemble_find(struct ieee80211_sub_if_data *sdata,
1620 			  unsigned int frag, unsigned int seq,
1621 			  int rx_queue, struct ieee80211_hdr *hdr)
1622 {
1623 	struct ieee80211_fragment_entry *entry;
1624 	int i, idx;
1625 
1626 	idx = sdata->fragment_next;
1627 	for (i = 0; i < IEEE80211_FRAGMENT_MAX; i++) {
1628 		struct ieee80211_hdr *f_hdr;
1629 
1630 		idx--;
1631 		if (idx < 0)
1632 			idx = IEEE80211_FRAGMENT_MAX - 1;
1633 
1634 		entry = &sdata->fragments[idx];
1635 		if (skb_queue_empty(&entry->skb_list) || entry->seq != seq ||
1636 		    entry->rx_queue != rx_queue ||
1637 		    entry->last_frag + 1 != frag)
1638 			continue;
1639 
1640 		f_hdr = (struct ieee80211_hdr *)entry->skb_list.next->data;
1641 
1642 		/*
1643 		 * Check ftype and addresses are equal, else check next fragment
1644 		 */
1645 		if (((hdr->frame_control ^ f_hdr->frame_control) &
1646 		     cpu_to_le16(IEEE80211_FCTL_FTYPE)) ||
1647 		    !ether_addr_equal(hdr->addr1, f_hdr->addr1) ||
1648 		    !ether_addr_equal(hdr->addr2, f_hdr->addr2))
1649 			continue;
1650 
1651 		if (time_after(jiffies, entry->first_frag_time + 2 * HZ)) {
1652 			__skb_queue_purge(&entry->skb_list);
1653 			continue;
1654 		}
1655 		return entry;
1656 	}
1657 
1658 	return NULL;
1659 }
1660 
1661 static ieee80211_rx_result debug_noinline
1662 ieee80211_rx_h_defragment(struct ieee80211_rx_data *rx)
1663 {
1664 	struct ieee80211_hdr *hdr;
1665 	u16 sc;
1666 	__le16 fc;
1667 	unsigned int frag, seq;
1668 	struct ieee80211_fragment_entry *entry;
1669 	struct sk_buff *skb;
1670 	struct ieee80211_rx_status *status;
1671 
1672 	hdr = (struct ieee80211_hdr *)rx->skb->data;
1673 	fc = hdr->frame_control;
1674 
1675 	if (ieee80211_is_ctl(fc))
1676 		return RX_CONTINUE;
1677 
1678 	sc = le16_to_cpu(hdr->seq_ctrl);
1679 	frag = sc & IEEE80211_SCTL_FRAG;
1680 
1681 	if (likely(!ieee80211_has_morefrags(fc) && frag == 0))
1682 		goto out;
1683 
1684 	if (is_multicast_ether_addr(hdr->addr1)) {
1685 		rx->local->dot11MulticastReceivedFrameCount++;
1686 		goto out;
1687 	}
1688 
1689 	I802_DEBUG_INC(rx->local->rx_handlers_fragments);
1690 
1691 	if (skb_linearize(rx->skb))
1692 		return RX_DROP_UNUSABLE;
1693 
1694 	/*
1695 	 *  skb_linearize() might change the skb->data and
1696 	 *  previously cached variables (in this case, hdr) need to
1697 	 *  be refreshed with the new data.
1698 	 */
1699 	hdr = (struct ieee80211_hdr *)rx->skb->data;
1700 	seq = (sc & IEEE80211_SCTL_SEQ) >> 4;
1701 
1702 	if (frag == 0) {
1703 		/* This is the first fragment of a new frame. */
1704 		entry = ieee80211_reassemble_add(rx->sdata, frag, seq,
1705 						 rx->seqno_idx, &(rx->skb));
1706 		if (rx->key && rx->key->conf.cipher == WLAN_CIPHER_SUITE_CCMP &&
1707 		    ieee80211_has_protected(fc)) {
1708 			int queue = rx->security_idx;
1709 			/* Store CCMP PN so that we can verify that the next
1710 			 * fragment has a sequential PN value. */
1711 			entry->ccmp = 1;
1712 			memcpy(entry->last_pn,
1713 			       rx->key->u.ccmp.rx_pn[queue],
1714 			       IEEE80211_CCMP_PN_LEN);
1715 		}
1716 		return RX_QUEUED;
1717 	}
1718 
1719 	/* This is a fragment for a frame that should already be pending in
1720 	 * fragment cache. Add this fragment to the end of the pending entry.
1721 	 */
1722 	entry = ieee80211_reassemble_find(rx->sdata, frag, seq,
1723 					  rx->seqno_idx, hdr);
1724 	if (!entry) {
1725 		I802_DEBUG_INC(rx->local->rx_handlers_drop_defrag);
1726 		return RX_DROP_MONITOR;
1727 	}
1728 
1729 	/* Verify that MPDUs within one MSDU have sequential PN values.
1730 	 * (IEEE 802.11i, 8.3.3.4.5) */
1731 	if (entry->ccmp) {
1732 		int i;
1733 		u8 pn[IEEE80211_CCMP_PN_LEN], *rpn;
1734 		int queue;
1735 		if (!rx->key || rx->key->conf.cipher != WLAN_CIPHER_SUITE_CCMP)
1736 			return RX_DROP_UNUSABLE;
1737 		memcpy(pn, entry->last_pn, IEEE80211_CCMP_PN_LEN);
1738 		for (i = IEEE80211_CCMP_PN_LEN - 1; i >= 0; i--) {
1739 			pn[i]++;
1740 			if (pn[i])
1741 				break;
1742 		}
1743 		queue = rx->security_idx;
1744 		rpn = rx->key->u.ccmp.rx_pn[queue];
1745 		if (memcmp(pn, rpn, IEEE80211_CCMP_PN_LEN))
1746 			return RX_DROP_UNUSABLE;
1747 		memcpy(entry->last_pn, pn, IEEE80211_CCMP_PN_LEN);
1748 	}
1749 
1750 	skb_pull(rx->skb, ieee80211_hdrlen(fc));
1751 	__skb_queue_tail(&entry->skb_list, rx->skb);
1752 	entry->last_frag = frag;
1753 	entry->extra_len += rx->skb->len;
1754 	if (ieee80211_has_morefrags(fc)) {
1755 		rx->skb = NULL;
1756 		return RX_QUEUED;
1757 	}
1758 
1759 	rx->skb = __skb_dequeue(&entry->skb_list);
1760 	if (skb_tailroom(rx->skb) < entry->extra_len) {
1761 		I802_DEBUG_INC(rx->local->rx_expand_skb_head2);
1762 		if (unlikely(pskb_expand_head(rx->skb, 0, entry->extra_len,
1763 					      GFP_ATOMIC))) {
1764 			I802_DEBUG_INC(rx->local->rx_handlers_drop_defrag);
1765 			__skb_queue_purge(&entry->skb_list);
1766 			return RX_DROP_UNUSABLE;
1767 		}
1768 	}
1769 	while ((skb = __skb_dequeue(&entry->skb_list))) {
1770 		memcpy(skb_put(rx->skb, skb->len), skb->data, skb->len);
1771 		dev_kfree_skb(skb);
1772 	}
1773 
1774 	/* Complete frame has been reassembled - process it now */
1775 	status = IEEE80211_SKB_RXCB(rx->skb);
1776 	status->rx_flags |= IEEE80211_RX_FRAGMENTED;
1777 
1778  out:
1779 	if (rx->sta)
1780 		rx->sta->rx_packets++;
1781 	ieee80211_led_rx(rx->local);
1782 	return RX_CONTINUE;
1783 }
1784 
1785 static int ieee80211_802_1x_port_control(struct ieee80211_rx_data *rx)
1786 {
1787 	if (unlikely(!rx->sta || !test_sta_flag(rx->sta, WLAN_STA_AUTHORIZED)))
1788 		return -EACCES;
1789 
1790 	return 0;
1791 }
1792 
1793 static int ieee80211_drop_unencrypted(struct ieee80211_rx_data *rx, __le16 fc)
1794 {
1795 	struct sk_buff *skb = rx->skb;
1796 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
1797 
1798 	/*
1799 	 * Pass through unencrypted frames if the hardware has
1800 	 * decrypted them already.
1801 	 */
1802 	if (status->flag & RX_FLAG_DECRYPTED)
1803 		return 0;
1804 
1805 	/* Drop unencrypted frames if key is set. */
1806 	if (unlikely(!ieee80211_has_protected(fc) &&
1807 		     !ieee80211_is_nullfunc(fc) &&
1808 		     ieee80211_is_data(fc) &&
1809 		     (rx->key || rx->sdata->drop_unencrypted)))
1810 		return -EACCES;
1811 
1812 	return 0;
1813 }
1814 
1815 static int ieee80211_drop_unencrypted_mgmt(struct ieee80211_rx_data *rx)
1816 {
1817 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
1818 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
1819 	__le16 fc = hdr->frame_control;
1820 
1821 	/*
1822 	 * Pass through unencrypted frames if the hardware has
1823 	 * decrypted them already.
1824 	 */
1825 	if (status->flag & RX_FLAG_DECRYPTED)
1826 		return 0;
1827 
1828 	if (rx->sta && test_sta_flag(rx->sta, WLAN_STA_MFP)) {
1829 		if (unlikely(!ieee80211_has_protected(fc) &&
1830 			     ieee80211_is_unicast_robust_mgmt_frame(rx->skb) &&
1831 			     rx->key)) {
1832 			if (ieee80211_is_deauth(fc) ||
1833 			    ieee80211_is_disassoc(fc))
1834 				cfg80211_rx_unprot_mlme_mgmt(rx->sdata->dev,
1835 							     rx->skb->data,
1836 							     rx->skb->len);
1837 			return -EACCES;
1838 		}
1839 		/* BIP does not use Protected field, so need to check MMIE */
1840 		if (unlikely(ieee80211_is_multicast_robust_mgmt_frame(rx->skb) &&
1841 			     ieee80211_get_mmie_keyidx(rx->skb) < 0)) {
1842 			if (ieee80211_is_deauth(fc) ||
1843 			    ieee80211_is_disassoc(fc))
1844 				cfg80211_rx_unprot_mlme_mgmt(rx->sdata->dev,
1845 							     rx->skb->data,
1846 							     rx->skb->len);
1847 			return -EACCES;
1848 		}
1849 		/*
1850 		 * When using MFP, Action frames are not allowed prior to
1851 		 * having configured keys.
1852 		 */
1853 		if (unlikely(ieee80211_is_action(fc) && !rx->key &&
1854 			     ieee80211_is_robust_mgmt_frame(rx->skb)))
1855 			return -EACCES;
1856 	}
1857 
1858 	return 0;
1859 }
1860 
1861 static int
1862 __ieee80211_data_to_8023(struct ieee80211_rx_data *rx, bool *port_control)
1863 {
1864 	struct ieee80211_sub_if_data *sdata = rx->sdata;
1865 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
1866 	bool check_port_control = false;
1867 	struct ethhdr *ehdr;
1868 	int ret;
1869 
1870 	*port_control = false;
1871 	if (ieee80211_has_a4(hdr->frame_control) &&
1872 	    sdata->vif.type == NL80211_IFTYPE_AP_VLAN && !sdata->u.vlan.sta)
1873 		return -1;
1874 
1875 	if (sdata->vif.type == NL80211_IFTYPE_STATION &&
1876 	    !!sdata->u.mgd.use_4addr != !!ieee80211_has_a4(hdr->frame_control)) {
1877 
1878 		if (!sdata->u.mgd.use_4addr)
1879 			return -1;
1880 		else
1881 			check_port_control = true;
1882 	}
1883 
1884 	if (is_multicast_ether_addr(hdr->addr1) &&
1885 	    sdata->vif.type == NL80211_IFTYPE_AP_VLAN && sdata->u.vlan.sta)
1886 		return -1;
1887 
1888 	ret = ieee80211_data_to_8023(rx->skb, sdata->vif.addr, sdata->vif.type);
1889 	if (ret < 0)
1890 		return ret;
1891 
1892 	ehdr = (struct ethhdr *) rx->skb->data;
1893 	if (ehdr->h_proto == rx->sdata->control_port_protocol)
1894 		*port_control = true;
1895 	else if (check_port_control)
1896 		return -1;
1897 
1898 	return 0;
1899 }
1900 
1901 /*
1902  * requires that rx->skb is a frame with ethernet header
1903  */
1904 static bool ieee80211_frame_allowed(struct ieee80211_rx_data *rx, __le16 fc)
1905 {
1906 	static const u8 pae_group_addr[ETH_ALEN] __aligned(2)
1907 		= { 0x01, 0x80, 0xC2, 0x00, 0x00, 0x03 };
1908 	struct ethhdr *ehdr = (struct ethhdr *) rx->skb->data;
1909 
1910 	/*
1911 	 * Allow EAPOL frames to us/the PAE group address regardless
1912 	 * of whether the frame was encrypted or not.
1913 	 */
1914 	if (ehdr->h_proto == rx->sdata->control_port_protocol &&
1915 	    (ether_addr_equal(ehdr->h_dest, rx->sdata->vif.addr) ||
1916 	     ether_addr_equal(ehdr->h_dest, pae_group_addr)))
1917 		return true;
1918 
1919 	if (ieee80211_802_1x_port_control(rx) ||
1920 	    ieee80211_drop_unencrypted(rx, fc))
1921 		return false;
1922 
1923 	return true;
1924 }
1925 
1926 /*
1927  * requires that rx->skb is a frame with ethernet header
1928  */
1929 static void
1930 ieee80211_deliver_skb(struct ieee80211_rx_data *rx)
1931 {
1932 	struct ieee80211_sub_if_data *sdata = rx->sdata;
1933 	struct net_device *dev = sdata->dev;
1934 	struct sk_buff *skb, *xmit_skb;
1935 	struct ethhdr *ehdr = (struct ethhdr *) rx->skb->data;
1936 	struct sta_info *dsta;
1937 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
1938 
1939 	skb = rx->skb;
1940 	xmit_skb = NULL;
1941 
1942 	if ((sdata->vif.type == NL80211_IFTYPE_AP ||
1943 	     sdata->vif.type == NL80211_IFTYPE_AP_VLAN) &&
1944 	    !(sdata->flags & IEEE80211_SDATA_DONT_BRIDGE_PACKETS) &&
1945 	    (status->rx_flags & IEEE80211_RX_RA_MATCH) &&
1946 	    (sdata->vif.type != NL80211_IFTYPE_AP_VLAN || !sdata->u.vlan.sta)) {
1947 		if (is_multicast_ether_addr(ehdr->h_dest)) {
1948 			/*
1949 			 * send multicast frames both to higher layers in
1950 			 * local net stack and back to the wireless medium
1951 			 */
1952 			xmit_skb = skb_copy(skb, GFP_ATOMIC);
1953 			if (!xmit_skb)
1954 				net_info_ratelimited("%s: failed to clone multicast frame\n",
1955 						    dev->name);
1956 		} else {
1957 			dsta = sta_info_get(sdata, skb->data);
1958 			if (dsta) {
1959 				/*
1960 				 * The destination station is associated to
1961 				 * this AP (in this VLAN), so send the frame
1962 				 * directly to it and do not pass it to local
1963 				 * net stack.
1964 				 */
1965 				xmit_skb = skb;
1966 				skb = NULL;
1967 			}
1968 		}
1969 	}
1970 
1971 #ifndef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
1972 	if (skb) {
1973 		/* 'align' will only take the values 0 or 2 here since all
1974 		 * frames are required to be aligned to 2-byte boundaries
1975 		 * when being passed to mac80211; the code here works just
1976 		 * as well if that isn't true, but mac80211 assumes it can
1977 		 * access fields as 2-byte aligned (e.g. for ether_addr_equal)
1978 		 */
1979 		int align;
1980 
1981 		align = (unsigned long)(skb->data + sizeof(struct ethhdr)) & 3;
1982 		if (align) {
1983 			if (WARN_ON(skb_headroom(skb) < 3)) {
1984 				dev_kfree_skb(skb);
1985 				skb = NULL;
1986 			} else {
1987 				u8 *data = skb->data;
1988 				size_t len = skb_headlen(skb);
1989 				skb->data -= align;
1990 				memmove(skb->data, data, len);
1991 				skb_set_tail_pointer(skb, len);
1992 			}
1993 		}
1994 	}
1995 #endif
1996 
1997 	if (skb) {
1998 		/* deliver to local stack */
1999 		skb->protocol = eth_type_trans(skb, dev);
2000 		memset(skb->cb, 0, sizeof(skb->cb));
2001 		if (rx->local->napi)
2002 			napi_gro_receive(rx->local->napi, skb);
2003 		else
2004 			netif_receive_skb(skb);
2005 	}
2006 
2007 	if (xmit_skb) {
2008 		/*
2009 		 * Send to wireless media and increase priority by 256 to
2010 		 * keep the received priority instead of reclassifying
2011 		 * the frame (see cfg80211_classify8021d).
2012 		 */
2013 		xmit_skb->priority += 256;
2014 		xmit_skb->protocol = htons(ETH_P_802_3);
2015 		skb_reset_network_header(xmit_skb);
2016 		skb_reset_mac_header(xmit_skb);
2017 		dev_queue_xmit(xmit_skb);
2018 	}
2019 }
2020 
2021 static ieee80211_rx_result debug_noinline
2022 ieee80211_rx_h_amsdu(struct ieee80211_rx_data *rx)
2023 {
2024 	struct net_device *dev = rx->sdata->dev;
2025 	struct sk_buff *skb = rx->skb;
2026 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
2027 	__le16 fc = hdr->frame_control;
2028 	struct sk_buff_head frame_list;
2029 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
2030 
2031 	if (unlikely(!ieee80211_is_data(fc)))
2032 		return RX_CONTINUE;
2033 
2034 	if (unlikely(!ieee80211_is_data_present(fc)))
2035 		return RX_DROP_MONITOR;
2036 
2037 	if (!(status->rx_flags & IEEE80211_RX_AMSDU))
2038 		return RX_CONTINUE;
2039 
2040 	if (ieee80211_has_a4(hdr->frame_control) &&
2041 	    rx->sdata->vif.type == NL80211_IFTYPE_AP_VLAN &&
2042 	    !rx->sdata->u.vlan.sta)
2043 		return RX_DROP_UNUSABLE;
2044 
2045 	if (is_multicast_ether_addr(hdr->addr1) &&
2046 	    ((rx->sdata->vif.type == NL80211_IFTYPE_AP_VLAN &&
2047 	      rx->sdata->u.vlan.sta) ||
2048 	     (rx->sdata->vif.type == NL80211_IFTYPE_STATION &&
2049 	      rx->sdata->u.mgd.use_4addr)))
2050 		return RX_DROP_UNUSABLE;
2051 
2052 	skb->dev = dev;
2053 	__skb_queue_head_init(&frame_list);
2054 
2055 	if (skb_linearize(skb))
2056 		return RX_DROP_UNUSABLE;
2057 
2058 	ieee80211_amsdu_to_8023s(skb, &frame_list, dev->dev_addr,
2059 				 rx->sdata->vif.type,
2060 				 rx->local->hw.extra_tx_headroom, true);
2061 
2062 	while (!skb_queue_empty(&frame_list)) {
2063 		rx->skb = __skb_dequeue(&frame_list);
2064 
2065 		if (!ieee80211_frame_allowed(rx, fc)) {
2066 			dev_kfree_skb(rx->skb);
2067 			continue;
2068 		}
2069 		dev->stats.rx_packets++;
2070 		dev->stats.rx_bytes += rx->skb->len;
2071 
2072 		ieee80211_deliver_skb(rx);
2073 	}
2074 
2075 	return RX_QUEUED;
2076 }
2077 
2078 #ifdef CONFIG_MAC80211_MESH
2079 static ieee80211_rx_result
2080 ieee80211_rx_h_mesh_fwding(struct ieee80211_rx_data *rx)
2081 {
2082 	struct ieee80211_hdr *fwd_hdr, *hdr;
2083 	struct ieee80211_tx_info *info;
2084 	struct ieee80211s_hdr *mesh_hdr;
2085 	struct sk_buff *skb = rx->skb, *fwd_skb;
2086 	struct ieee80211_local *local = rx->local;
2087 	struct ieee80211_sub_if_data *sdata = rx->sdata;
2088 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
2089 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
2090 	u16 q, hdrlen;
2091 
2092 	hdr = (struct ieee80211_hdr *) skb->data;
2093 	hdrlen = ieee80211_hdrlen(hdr->frame_control);
2094 
2095 	/* make sure fixed part of mesh header is there, also checks skb len */
2096 	if (!pskb_may_pull(rx->skb, hdrlen + 6))
2097 		return RX_DROP_MONITOR;
2098 
2099 	mesh_hdr = (struct ieee80211s_hdr *) (skb->data + hdrlen);
2100 
2101 	/* make sure full mesh header is there, also checks skb len */
2102 	if (!pskb_may_pull(rx->skb,
2103 			   hdrlen + ieee80211_get_mesh_hdrlen(mesh_hdr)))
2104 		return RX_DROP_MONITOR;
2105 
2106 	/* reload pointers */
2107 	hdr = (struct ieee80211_hdr *) skb->data;
2108 	mesh_hdr = (struct ieee80211s_hdr *) (skb->data + hdrlen);
2109 
2110 	/* frame is in RMC, don't forward */
2111 	if (ieee80211_is_data(hdr->frame_control) &&
2112 	    is_multicast_ether_addr(hdr->addr1) &&
2113 	    mesh_rmc_check(rx->sdata, hdr->addr3, mesh_hdr))
2114 		return RX_DROP_MONITOR;
2115 
2116 	if (!ieee80211_is_data(hdr->frame_control) ||
2117 	    !(status->rx_flags & IEEE80211_RX_RA_MATCH))
2118 		return RX_CONTINUE;
2119 
2120 	if (!mesh_hdr->ttl)
2121 		return RX_DROP_MONITOR;
2122 
2123 	if (mesh_hdr->flags & MESH_FLAGS_AE) {
2124 		struct mesh_path *mppath;
2125 		char *proxied_addr;
2126 		char *mpp_addr;
2127 
2128 		if (is_multicast_ether_addr(hdr->addr1)) {
2129 			mpp_addr = hdr->addr3;
2130 			proxied_addr = mesh_hdr->eaddr1;
2131 		} else if (mesh_hdr->flags & MESH_FLAGS_AE_A5_A6) {
2132 			/* has_a4 already checked in ieee80211_rx_mesh_check */
2133 			mpp_addr = hdr->addr4;
2134 			proxied_addr = mesh_hdr->eaddr2;
2135 		} else {
2136 			return RX_DROP_MONITOR;
2137 		}
2138 
2139 		rcu_read_lock();
2140 		mppath = mpp_path_lookup(sdata, proxied_addr);
2141 		if (!mppath) {
2142 			mpp_path_add(sdata, proxied_addr, mpp_addr);
2143 		} else {
2144 			spin_lock_bh(&mppath->state_lock);
2145 			if (!ether_addr_equal(mppath->mpp, mpp_addr))
2146 				memcpy(mppath->mpp, mpp_addr, ETH_ALEN);
2147 			spin_unlock_bh(&mppath->state_lock);
2148 		}
2149 		rcu_read_unlock();
2150 	}
2151 
2152 	/* Frame has reached destination.  Don't forward */
2153 	if (!is_multicast_ether_addr(hdr->addr1) &&
2154 	    ether_addr_equal(sdata->vif.addr, hdr->addr3))
2155 		return RX_CONTINUE;
2156 
2157 	q = ieee80211_select_queue_80211(sdata, skb, hdr);
2158 	if (ieee80211_queue_stopped(&local->hw, q)) {
2159 		IEEE80211_IFSTA_MESH_CTR_INC(ifmsh, dropped_frames_congestion);
2160 		return RX_DROP_MONITOR;
2161 	}
2162 	skb_set_queue_mapping(skb, q);
2163 
2164 	if (!--mesh_hdr->ttl) {
2165 		IEEE80211_IFSTA_MESH_CTR_INC(ifmsh, dropped_frames_ttl);
2166 		goto out;
2167 	}
2168 
2169 	if (!ifmsh->mshcfg.dot11MeshForwarding)
2170 		goto out;
2171 
2172 	fwd_skb = skb_copy(skb, GFP_ATOMIC);
2173 	if (!fwd_skb) {
2174 		net_info_ratelimited("%s: failed to clone mesh frame\n",
2175 				    sdata->name);
2176 		goto out;
2177 	}
2178 
2179 	fwd_hdr =  (struct ieee80211_hdr *) fwd_skb->data;
2180 	fwd_hdr->frame_control &= ~cpu_to_le16(IEEE80211_FCTL_RETRY);
2181 	info = IEEE80211_SKB_CB(fwd_skb);
2182 	memset(info, 0, sizeof(*info));
2183 	info->flags |= IEEE80211_TX_INTFL_NEED_TXPROCESSING;
2184 	info->control.vif = &rx->sdata->vif;
2185 	info->control.jiffies = jiffies;
2186 	if (is_multicast_ether_addr(fwd_hdr->addr1)) {
2187 		IEEE80211_IFSTA_MESH_CTR_INC(ifmsh, fwded_mcast);
2188 		memcpy(fwd_hdr->addr2, sdata->vif.addr, ETH_ALEN);
2189 		/* update power mode indication when forwarding */
2190 		ieee80211_mps_set_frame_flags(sdata, NULL, fwd_hdr);
2191 	} else if (!mesh_nexthop_lookup(sdata, fwd_skb)) {
2192 		/* mesh power mode flags updated in mesh_nexthop_lookup */
2193 		IEEE80211_IFSTA_MESH_CTR_INC(ifmsh, fwded_unicast);
2194 	} else {
2195 		/* unable to resolve next hop */
2196 		mesh_path_error_tx(sdata, ifmsh->mshcfg.element_ttl,
2197 				   fwd_hdr->addr3, 0,
2198 				   WLAN_REASON_MESH_PATH_NOFORWARD,
2199 				   fwd_hdr->addr2);
2200 		IEEE80211_IFSTA_MESH_CTR_INC(ifmsh, dropped_frames_no_route);
2201 		kfree_skb(fwd_skb);
2202 		return RX_DROP_MONITOR;
2203 	}
2204 
2205 	IEEE80211_IFSTA_MESH_CTR_INC(ifmsh, fwded_frames);
2206 	ieee80211_add_pending_skb(local, fwd_skb);
2207  out:
2208 	if (is_multicast_ether_addr(hdr->addr1) ||
2209 	    sdata->dev->flags & IFF_PROMISC)
2210 		return RX_CONTINUE;
2211 	else
2212 		return RX_DROP_MONITOR;
2213 }
2214 #endif
2215 
2216 static ieee80211_rx_result debug_noinline
2217 ieee80211_rx_h_data(struct ieee80211_rx_data *rx)
2218 {
2219 	struct ieee80211_sub_if_data *sdata = rx->sdata;
2220 	struct ieee80211_local *local = rx->local;
2221 	struct net_device *dev = sdata->dev;
2222 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
2223 	__le16 fc = hdr->frame_control;
2224 	bool port_control;
2225 	int err;
2226 
2227 	if (unlikely(!ieee80211_is_data(hdr->frame_control)))
2228 		return RX_CONTINUE;
2229 
2230 	if (unlikely(!ieee80211_is_data_present(hdr->frame_control)))
2231 		return RX_DROP_MONITOR;
2232 
2233 	/*
2234 	 * Send unexpected-4addr-frame event to hostapd. For older versions,
2235 	 * also drop the frame to cooked monitor interfaces.
2236 	 */
2237 	if (ieee80211_has_a4(hdr->frame_control) &&
2238 	    sdata->vif.type == NL80211_IFTYPE_AP) {
2239 		if (rx->sta &&
2240 		    !test_and_set_sta_flag(rx->sta, WLAN_STA_4ADDR_EVENT))
2241 			cfg80211_rx_unexpected_4addr_frame(
2242 				rx->sdata->dev, rx->sta->sta.addr, GFP_ATOMIC);
2243 		return RX_DROP_MONITOR;
2244 	}
2245 
2246 	err = __ieee80211_data_to_8023(rx, &port_control);
2247 	if (unlikely(err))
2248 		return RX_DROP_UNUSABLE;
2249 
2250 	if (!ieee80211_frame_allowed(rx, fc))
2251 		return RX_DROP_MONITOR;
2252 
2253 	if (rx->sdata->vif.type == NL80211_IFTYPE_AP_VLAN &&
2254 	    unlikely(port_control) && sdata->bss) {
2255 		sdata = container_of(sdata->bss, struct ieee80211_sub_if_data,
2256 				     u.ap);
2257 		dev = sdata->dev;
2258 		rx->sdata = sdata;
2259 	}
2260 
2261 	rx->skb->dev = dev;
2262 
2263 	dev->stats.rx_packets++;
2264 	dev->stats.rx_bytes += rx->skb->len;
2265 
2266 	if (local->ps_sdata && local->hw.conf.dynamic_ps_timeout > 0 &&
2267 	    !is_multicast_ether_addr(
2268 		    ((struct ethhdr *)rx->skb->data)->h_dest) &&
2269 	    (!local->scanning &&
2270 	     !test_bit(SDATA_STATE_OFFCHANNEL, &sdata->state))) {
2271 			mod_timer(&local->dynamic_ps_timer, jiffies +
2272 			 msecs_to_jiffies(local->hw.conf.dynamic_ps_timeout));
2273 	}
2274 
2275 	ieee80211_deliver_skb(rx);
2276 
2277 	return RX_QUEUED;
2278 }
2279 
2280 static ieee80211_rx_result debug_noinline
2281 ieee80211_rx_h_ctrl(struct ieee80211_rx_data *rx, struct sk_buff_head *frames)
2282 {
2283 	struct sk_buff *skb = rx->skb;
2284 	struct ieee80211_bar *bar = (struct ieee80211_bar *)skb->data;
2285 	struct tid_ampdu_rx *tid_agg_rx;
2286 	u16 start_seq_num;
2287 	u16 tid;
2288 
2289 	if (likely(!ieee80211_is_ctl(bar->frame_control)))
2290 		return RX_CONTINUE;
2291 
2292 	if (ieee80211_is_back_req(bar->frame_control)) {
2293 		struct {
2294 			__le16 control, start_seq_num;
2295 		} __packed bar_data;
2296 
2297 		if (!rx->sta)
2298 			return RX_DROP_MONITOR;
2299 
2300 		if (skb_copy_bits(skb, offsetof(struct ieee80211_bar, control),
2301 				  &bar_data, sizeof(bar_data)))
2302 			return RX_DROP_MONITOR;
2303 
2304 		tid = le16_to_cpu(bar_data.control) >> 12;
2305 
2306 		tid_agg_rx = rcu_dereference(rx->sta->ampdu_mlme.tid_rx[tid]);
2307 		if (!tid_agg_rx)
2308 			return RX_DROP_MONITOR;
2309 
2310 		start_seq_num = le16_to_cpu(bar_data.start_seq_num) >> 4;
2311 
2312 		/* reset session timer */
2313 		if (tid_agg_rx->timeout)
2314 			mod_timer(&tid_agg_rx->session_timer,
2315 				  TU_TO_EXP_TIME(tid_agg_rx->timeout));
2316 
2317 		spin_lock(&tid_agg_rx->reorder_lock);
2318 		/* release stored frames up to start of BAR */
2319 		ieee80211_release_reorder_frames(rx->sdata, tid_agg_rx,
2320 						 start_seq_num, frames);
2321 		spin_unlock(&tid_agg_rx->reorder_lock);
2322 
2323 		kfree_skb(skb);
2324 		return RX_QUEUED;
2325 	}
2326 
2327 	/*
2328 	 * After this point, we only want management frames,
2329 	 * so we can drop all remaining control frames to
2330 	 * cooked monitor interfaces.
2331 	 */
2332 	return RX_DROP_MONITOR;
2333 }
2334 
2335 static void ieee80211_process_sa_query_req(struct ieee80211_sub_if_data *sdata,
2336 					   struct ieee80211_mgmt *mgmt,
2337 					   size_t len)
2338 {
2339 	struct ieee80211_local *local = sdata->local;
2340 	struct sk_buff *skb;
2341 	struct ieee80211_mgmt *resp;
2342 
2343 	if (!ether_addr_equal(mgmt->da, sdata->vif.addr)) {
2344 		/* Not to own unicast address */
2345 		return;
2346 	}
2347 
2348 	if (!ether_addr_equal(mgmt->sa, sdata->u.mgd.bssid) ||
2349 	    !ether_addr_equal(mgmt->bssid, sdata->u.mgd.bssid)) {
2350 		/* Not from the current AP or not associated yet. */
2351 		return;
2352 	}
2353 
2354 	if (len < 24 + 1 + sizeof(resp->u.action.u.sa_query)) {
2355 		/* Too short SA Query request frame */
2356 		return;
2357 	}
2358 
2359 	skb = dev_alloc_skb(sizeof(*resp) + local->hw.extra_tx_headroom);
2360 	if (skb == NULL)
2361 		return;
2362 
2363 	skb_reserve(skb, local->hw.extra_tx_headroom);
2364 	resp = (struct ieee80211_mgmt *) skb_put(skb, 24);
2365 	memset(resp, 0, 24);
2366 	memcpy(resp->da, mgmt->sa, ETH_ALEN);
2367 	memcpy(resp->sa, sdata->vif.addr, ETH_ALEN);
2368 	memcpy(resp->bssid, sdata->u.mgd.bssid, ETH_ALEN);
2369 	resp->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
2370 					  IEEE80211_STYPE_ACTION);
2371 	skb_put(skb, 1 + sizeof(resp->u.action.u.sa_query));
2372 	resp->u.action.category = WLAN_CATEGORY_SA_QUERY;
2373 	resp->u.action.u.sa_query.action = WLAN_ACTION_SA_QUERY_RESPONSE;
2374 	memcpy(resp->u.action.u.sa_query.trans_id,
2375 	       mgmt->u.action.u.sa_query.trans_id,
2376 	       WLAN_SA_QUERY_TR_ID_LEN);
2377 
2378 	ieee80211_tx_skb(sdata, skb);
2379 }
2380 
2381 static ieee80211_rx_result debug_noinline
2382 ieee80211_rx_h_mgmt_check(struct ieee80211_rx_data *rx)
2383 {
2384 	struct ieee80211_mgmt *mgmt = (struct ieee80211_mgmt *) rx->skb->data;
2385 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
2386 
2387 	/*
2388 	 * From here on, look only at management frames.
2389 	 * Data and control frames are already handled,
2390 	 * and unknown (reserved) frames are useless.
2391 	 */
2392 	if (rx->skb->len < 24)
2393 		return RX_DROP_MONITOR;
2394 
2395 	if (!ieee80211_is_mgmt(mgmt->frame_control))
2396 		return RX_DROP_MONITOR;
2397 
2398 	if (rx->sdata->vif.type == NL80211_IFTYPE_AP &&
2399 	    ieee80211_is_beacon(mgmt->frame_control) &&
2400 	    !(rx->flags & IEEE80211_RX_BEACON_REPORTED)) {
2401 		int sig = 0;
2402 
2403 		if (rx->local->hw.flags & IEEE80211_HW_SIGNAL_DBM)
2404 			sig = status->signal;
2405 
2406 		cfg80211_report_obss_beacon(rx->local->hw.wiphy,
2407 					    rx->skb->data, rx->skb->len,
2408 					    status->freq, sig);
2409 		rx->flags |= IEEE80211_RX_BEACON_REPORTED;
2410 	}
2411 
2412 	if (!(status->rx_flags & IEEE80211_RX_RA_MATCH))
2413 		return RX_DROP_MONITOR;
2414 
2415 	if (ieee80211_drop_unencrypted_mgmt(rx))
2416 		return RX_DROP_UNUSABLE;
2417 
2418 	return RX_CONTINUE;
2419 }
2420 
2421 static ieee80211_rx_result debug_noinline
2422 ieee80211_rx_h_action(struct ieee80211_rx_data *rx)
2423 {
2424 	struct ieee80211_local *local = rx->local;
2425 	struct ieee80211_sub_if_data *sdata = rx->sdata;
2426 	struct ieee80211_mgmt *mgmt = (struct ieee80211_mgmt *) rx->skb->data;
2427 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
2428 	int len = rx->skb->len;
2429 
2430 	if (!ieee80211_is_action(mgmt->frame_control))
2431 		return RX_CONTINUE;
2432 
2433 	/* drop too small frames */
2434 	if (len < IEEE80211_MIN_ACTION_SIZE)
2435 		return RX_DROP_UNUSABLE;
2436 
2437 	if (!rx->sta && mgmt->u.action.category != WLAN_CATEGORY_PUBLIC &&
2438 	    mgmt->u.action.category != WLAN_CATEGORY_SELF_PROTECTED &&
2439 	    mgmt->u.action.category != WLAN_CATEGORY_SPECTRUM_MGMT)
2440 		return RX_DROP_UNUSABLE;
2441 
2442 	if (!(status->rx_flags & IEEE80211_RX_RA_MATCH))
2443 		return RX_DROP_UNUSABLE;
2444 
2445 	switch (mgmt->u.action.category) {
2446 	case WLAN_CATEGORY_HT:
2447 		/* reject HT action frames from stations not supporting HT */
2448 		if (!rx->sta->sta.ht_cap.ht_supported)
2449 			goto invalid;
2450 
2451 		if (sdata->vif.type != NL80211_IFTYPE_STATION &&
2452 		    sdata->vif.type != NL80211_IFTYPE_MESH_POINT &&
2453 		    sdata->vif.type != NL80211_IFTYPE_AP_VLAN &&
2454 		    sdata->vif.type != NL80211_IFTYPE_AP &&
2455 		    sdata->vif.type != NL80211_IFTYPE_ADHOC)
2456 			break;
2457 
2458 		/* verify action & smps_control/chanwidth are present */
2459 		if (len < IEEE80211_MIN_ACTION_SIZE + 2)
2460 			goto invalid;
2461 
2462 		switch (mgmt->u.action.u.ht_smps.action) {
2463 		case WLAN_HT_ACTION_SMPS: {
2464 			struct ieee80211_supported_band *sband;
2465 			enum ieee80211_smps_mode smps_mode;
2466 
2467 			/* convert to HT capability */
2468 			switch (mgmt->u.action.u.ht_smps.smps_control) {
2469 			case WLAN_HT_SMPS_CONTROL_DISABLED:
2470 				smps_mode = IEEE80211_SMPS_OFF;
2471 				break;
2472 			case WLAN_HT_SMPS_CONTROL_STATIC:
2473 				smps_mode = IEEE80211_SMPS_STATIC;
2474 				break;
2475 			case WLAN_HT_SMPS_CONTROL_DYNAMIC:
2476 				smps_mode = IEEE80211_SMPS_DYNAMIC;
2477 				break;
2478 			default:
2479 				goto invalid;
2480 			}
2481 
2482 			/* if no change do nothing */
2483 			if (rx->sta->sta.smps_mode == smps_mode)
2484 				goto handled;
2485 			rx->sta->sta.smps_mode = smps_mode;
2486 
2487 			sband = rx->local->hw.wiphy->bands[status->band];
2488 
2489 			rate_control_rate_update(local, sband, rx->sta,
2490 						 IEEE80211_RC_SMPS_CHANGED);
2491 			goto handled;
2492 		}
2493 		case WLAN_HT_ACTION_NOTIFY_CHANWIDTH: {
2494 			struct ieee80211_supported_band *sband;
2495 			u8 chanwidth = mgmt->u.action.u.ht_notify_cw.chanwidth;
2496 			enum ieee80211_sta_rx_bandwidth new_bw;
2497 
2498 			/* If it doesn't support 40 MHz it can't change ... */
2499 			if (!(rx->sta->sta.ht_cap.cap &
2500 					IEEE80211_HT_CAP_SUP_WIDTH_20_40))
2501 				goto handled;
2502 
2503 			if (chanwidth == IEEE80211_HT_CHANWIDTH_20MHZ)
2504 				new_bw = IEEE80211_STA_RX_BW_20;
2505 			else
2506 				new_bw = ieee80211_sta_cur_vht_bw(rx->sta);
2507 
2508 			if (rx->sta->sta.bandwidth == new_bw)
2509 				goto handled;
2510 
2511 			sband = rx->local->hw.wiphy->bands[status->band];
2512 
2513 			rate_control_rate_update(local, sband, rx->sta,
2514 						 IEEE80211_RC_BW_CHANGED);
2515 			goto handled;
2516 		}
2517 		default:
2518 			goto invalid;
2519 		}
2520 
2521 		break;
2522 	case WLAN_CATEGORY_PUBLIC:
2523 		if (len < IEEE80211_MIN_ACTION_SIZE + 1)
2524 			goto invalid;
2525 		if (sdata->vif.type != NL80211_IFTYPE_STATION)
2526 			break;
2527 		if (!rx->sta)
2528 			break;
2529 		if (!ether_addr_equal(mgmt->bssid, sdata->u.mgd.bssid))
2530 			break;
2531 		if (mgmt->u.action.u.ext_chan_switch.action_code !=
2532 				WLAN_PUB_ACTION_EXT_CHANSW_ANN)
2533 			break;
2534 		if (len < offsetof(struct ieee80211_mgmt,
2535 				   u.action.u.ext_chan_switch.variable))
2536 			goto invalid;
2537 		goto queue;
2538 	case WLAN_CATEGORY_VHT:
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 			goto invalid;
2549 
2550 		switch (mgmt->u.action.u.vht_opmode_notif.action_code) {
2551 		case WLAN_VHT_ACTION_OPMODE_NOTIF: {
2552 			u8 opmode;
2553 
2554 			/* verify opmode is present */
2555 			if (len < IEEE80211_MIN_ACTION_SIZE + 2)
2556 				goto invalid;
2557 
2558 			opmode = mgmt->u.action.u.vht_opmode_notif.operating_mode;
2559 
2560 			ieee80211_vht_handle_opmode(rx->sdata, rx->sta,
2561 						    opmode, status->band,
2562 						    false);
2563 			goto handled;
2564 		}
2565 		default:
2566 			break;
2567 		}
2568 		break;
2569 	case WLAN_CATEGORY_BACK:
2570 		if (sdata->vif.type != NL80211_IFTYPE_STATION &&
2571 		    sdata->vif.type != NL80211_IFTYPE_MESH_POINT &&
2572 		    sdata->vif.type != NL80211_IFTYPE_AP_VLAN &&
2573 		    sdata->vif.type != NL80211_IFTYPE_AP &&
2574 		    sdata->vif.type != NL80211_IFTYPE_ADHOC)
2575 			break;
2576 
2577 		/* verify action_code is present */
2578 		if (len < IEEE80211_MIN_ACTION_SIZE + 1)
2579 			break;
2580 
2581 		switch (mgmt->u.action.u.addba_req.action_code) {
2582 		case WLAN_ACTION_ADDBA_REQ:
2583 			if (len < (IEEE80211_MIN_ACTION_SIZE +
2584 				   sizeof(mgmt->u.action.u.addba_req)))
2585 				goto invalid;
2586 			break;
2587 		case WLAN_ACTION_ADDBA_RESP:
2588 			if (len < (IEEE80211_MIN_ACTION_SIZE +
2589 				   sizeof(mgmt->u.action.u.addba_resp)))
2590 				goto invalid;
2591 			break;
2592 		case WLAN_ACTION_DELBA:
2593 			if (len < (IEEE80211_MIN_ACTION_SIZE +
2594 				   sizeof(mgmt->u.action.u.delba)))
2595 				goto invalid;
2596 			break;
2597 		default:
2598 			goto invalid;
2599 		}
2600 
2601 		goto queue;
2602 	case WLAN_CATEGORY_SPECTRUM_MGMT:
2603 		/* verify action_code is present */
2604 		if (len < IEEE80211_MIN_ACTION_SIZE + 1)
2605 			break;
2606 
2607 		switch (mgmt->u.action.u.measurement.action_code) {
2608 		case WLAN_ACTION_SPCT_MSR_REQ:
2609 			if (status->band != IEEE80211_BAND_5GHZ)
2610 				break;
2611 
2612 			if (len < (IEEE80211_MIN_ACTION_SIZE +
2613 				   sizeof(mgmt->u.action.u.measurement)))
2614 				break;
2615 
2616 			if (sdata->vif.type != NL80211_IFTYPE_STATION)
2617 				break;
2618 
2619 			ieee80211_process_measurement_req(sdata, mgmt, len);
2620 			goto handled;
2621 		case WLAN_ACTION_SPCT_CHL_SWITCH: {
2622 			u8 *bssid;
2623 			if (len < (IEEE80211_MIN_ACTION_SIZE +
2624 				   sizeof(mgmt->u.action.u.chan_switch)))
2625 				break;
2626 
2627 			if (sdata->vif.type != NL80211_IFTYPE_STATION &&
2628 			    sdata->vif.type != NL80211_IFTYPE_ADHOC &&
2629 			    sdata->vif.type != NL80211_IFTYPE_MESH_POINT)
2630 				break;
2631 
2632 			if (sdata->vif.type == NL80211_IFTYPE_STATION)
2633 				bssid = sdata->u.mgd.bssid;
2634 			else if (sdata->vif.type == NL80211_IFTYPE_ADHOC)
2635 				bssid = sdata->u.ibss.bssid;
2636 			else if (sdata->vif.type == NL80211_IFTYPE_MESH_POINT)
2637 				bssid = mgmt->sa;
2638 			else
2639 				break;
2640 
2641 			if (!ether_addr_equal(mgmt->bssid, bssid))
2642 				break;
2643 
2644 			goto queue;
2645 			}
2646 		}
2647 		break;
2648 	case WLAN_CATEGORY_SA_QUERY:
2649 		if (len < (IEEE80211_MIN_ACTION_SIZE +
2650 			   sizeof(mgmt->u.action.u.sa_query)))
2651 			break;
2652 
2653 		switch (mgmt->u.action.u.sa_query.action) {
2654 		case WLAN_ACTION_SA_QUERY_REQUEST:
2655 			if (sdata->vif.type != NL80211_IFTYPE_STATION)
2656 				break;
2657 			ieee80211_process_sa_query_req(sdata, mgmt, len);
2658 			goto handled;
2659 		}
2660 		break;
2661 	case WLAN_CATEGORY_SELF_PROTECTED:
2662 		if (len < (IEEE80211_MIN_ACTION_SIZE +
2663 			   sizeof(mgmt->u.action.u.self_prot.action_code)))
2664 			break;
2665 
2666 		switch (mgmt->u.action.u.self_prot.action_code) {
2667 		case WLAN_SP_MESH_PEERING_OPEN:
2668 		case WLAN_SP_MESH_PEERING_CLOSE:
2669 		case WLAN_SP_MESH_PEERING_CONFIRM:
2670 			if (!ieee80211_vif_is_mesh(&sdata->vif))
2671 				goto invalid;
2672 			if (sdata->u.mesh.user_mpm)
2673 				/* userspace handles this frame */
2674 				break;
2675 			goto queue;
2676 		case WLAN_SP_MGK_INFORM:
2677 		case WLAN_SP_MGK_ACK:
2678 			if (!ieee80211_vif_is_mesh(&sdata->vif))
2679 				goto invalid;
2680 			break;
2681 		}
2682 		break;
2683 	case WLAN_CATEGORY_MESH_ACTION:
2684 		if (len < (IEEE80211_MIN_ACTION_SIZE +
2685 			   sizeof(mgmt->u.action.u.mesh_action.action_code)))
2686 			break;
2687 
2688 		if (!ieee80211_vif_is_mesh(&sdata->vif))
2689 			break;
2690 		if (mesh_action_is_path_sel(mgmt) &&
2691 		    !mesh_path_sel_is_hwmp(sdata))
2692 			break;
2693 		goto queue;
2694 	}
2695 
2696 	return RX_CONTINUE;
2697 
2698  invalid:
2699 	status->rx_flags |= IEEE80211_RX_MALFORMED_ACTION_FRM;
2700 	/* will return in the next handlers */
2701 	return RX_CONTINUE;
2702 
2703  handled:
2704 	if (rx->sta)
2705 		rx->sta->rx_packets++;
2706 	dev_kfree_skb(rx->skb);
2707 	return RX_QUEUED;
2708 
2709  queue:
2710 	rx->skb->pkt_type = IEEE80211_SDATA_QUEUE_TYPE_FRAME;
2711 	skb_queue_tail(&sdata->skb_queue, rx->skb);
2712 	ieee80211_queue_work(&local->hw, &sdata->work);
2713 	if (rx->sta)
2714 		rx->sta->rx_packets++;
2715 	return RX_QUEUED;
2716 }
2717 
2718 static ieee80211_rx_result debug_noinline
2719 ieee80211_rx_h_userspace_mgmt(struct ieee80211_rx_data *rx)
2720 {
2721 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
2722 	int sig = 0;
2723 
2724 	/* skip known-bad action frames and return them in the next handler */
2725 	if (status->rx_flags & IEEE80211_RX_MALFORMED_ACTION_FRM)
2726 		return RX_CONTINUE;
2727 
2728 	/*
2729 	 * Getting here means the kernel doesn't know how to handle
2730 	 * it, but maybe userspace does ... include returned frames
2731 	 * so userspace can register for those to know whether ones
2732 	 * it transmitted were processed or returned.
2733 	 */
2734 
2735 	if (rx->local->hw.flags & IEEE80211_HW_SIGNAL_DBM)
2736 		sig = status->signal;
2737 
2738 	if (cfg80211_rx_mgmt(&rx->sdata->wdev, status->freq, sig,
2739 			     rx->skb->data, rx->skb->len, 0)) {
2740 		if (rx->sta)
2741 			rx->sta->rx_packets++;
2742 		dev_kfree_skb(rx->skb);
2743 		return RX_QUEUED;
2744 	}
2745 
2746 	return RX_CONTINUE;
2747 }
2748 
2749 static ieee80211_rx_result debug_noinline
2750 ieee80211_rx_h_action_return(struct ieee80211_rx_data *rx)
2751 {
2752 	struct ieee80211_local *local = rx->local;
2753 	struct ieee80211_mgmt *mgmt = (struct ieee80211_mgmt *) rx->skb->data;
2754 	struct sk_buff *nskb;
2755 	struct ieee80211_sub_if_data *sdata = rx->sdata;
2756 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
2757 
2758 	if (!ieee80211_is_action(mgmt->frame_control))
2759 		return RX_CONTINUE;
2760 
2761 	/*
2762 	 * For AP mode, hostapd is responsible for handling any action
2763 	 * frames that we didn't handle, including returning unknown
2764 	 * ones. For all other modes we will return them to the sender,
2765 	 * setting the 0x80 bit in the action category, as required by
2766 	 * 802.11-2012 9.24.4.
2767 	 * Newer versions of hostapd shall also use the management frame
2768 	 * registration mechanisms, but older ones still use cooked
2769 	 * monitor interfaces so push all frames there.
2770 	 */
2771 	if (!(status->rx_flags & IEEE80211_RX_MALFORMED_ACTION_FRM) &&
2772 	    (sdata->vif.type == NL80211_IFTYPE_AP ||
2773 	     sdata->vif.type == NL80211_IFTYPE_AP_VLAN))
2774 		return RX_DROP_MONITOR;
2775 
2776 	if (is_multicast_ether_addr(mgmt->da))
2777 		return RX_DROP_MONITOR;
2778 
2779 	/* do not return rejected action frames */
2780 	if (mgmt->u.action.category & 0x80)
2781 		return RX_DROP_UNUSABLE;
2782 
2783 	nskb = skb_copy_expand(rx->skb, local->hw.extra_tx_headroom, 0,
2784 			       GFP_ATOMIC);
2785 	if (nskb) {
2786 		struct ieee80211_mgmt *nmgmt = (void *)nskb->data;
2787 
2788 		nmgmt->u.action.category |= 0x80;
2789 		memcpy(nmgmt->da, nmgmt->sa, ETH_ALEN);
2790 		memcpy(nmgmt->sa, rx->sdata->vif.addr, ETH_ALEN);
2791 
2792 		memset(nskb->cb, 0, sizeof(nskb->cb));
2793 
2794 		if (rx->sdata->vif.type == NL80211_IFTYPE_P2P_DEVICE) {
2795 			struct ieee80211_tx_info *info = IEEE80211_SKB_CB(nskb);
2796 
2797 			info->flags = IEEE80211_TX_CTL_TX_OFFCHAN |
2798 				      IEEE80211_TX_INTFL_OFFCHAN_TX_OK |
2799 				      IEEE80211_TX_CTL_NO_CCK_RATE;
2800 			if (local->hw.flags & IEEE80211_HW_QUEUE_CONTROL)
2801 				info->hw_queue =
2802 					local->hw.offchannel_tx_hw_queue;
2803 		}
2804 
2805 		__ieee80211_tx_skb_tid_band(rx->sdata, nskb, 7,
2806 					    status->band);
2807 	}
2808 	dev_kfree_skb(rx->skb);
2809 	return RX_QUEUED;
2810 }
2811 
2812 static ieee80211_rx_result debug_noinline
2813 ieee80211_rx_h_mgmt(struct ieee80211_rx_data *rx)
2814 {
2815 	struct ieee80211_sub_if_data *sdata = rx->sdata;
2816 	struct ieee80211_mgmt *mgmt = (void *)rx->skb->data;
2817 	__le16 stype;
2818 
2819 	stype = mgmt->frame_control & cpu_to_le16(IEEE80211_FCTL_STYPE);
2820 
2821 	if (!ieee80211_vif_is_mesh(&sdata->vif) &&
2822 	    sdata->vif.type != NL80211_IFTYPE_ADHOC &&
2823 	    sdata->vif.type != NL80211_IFTYPE_STATION)
2824 		return RX_DROP_MONITOR;
2825 
2826 	switch (stype) {
2827 	case cpu_to_le16(IEEE80211_STYPE_AUTH):
2828 	case cpu_to_le16(IEEE80211_STYPE_BEACON):
2829 	case cpu_to_le16(IEEE80211_STYPE_PROBE_RESP):
2830 		/* process for all: mesh, mlme, ibss */
2831 		break;
2832 	case cpu_to_le16(IEEE80211_STYPE_ASSOC_RESP):
2833 	case cpu_to_le16(IEEE80211_STYPE_REASSOC_RESP):
2834 	case cpu_to_le16(IEEE80211_STYPE_DEAUTH):
2835 	case cpu_to_le16(IEEE80211_STYPE_DISASSOC):
2836 		if (is_multicast_ether_addr(mgmt->da) &&
2837 		    !is_broadcast_ether_addr(mgmt->da))
2838 			return RX_DROP_MONITOR;
2839 
2840 		/* process only for station */
2841 		if (sdata->vif.type != NL80211_IFTYPE_STATION)
2842 			return RX_DROP_MONITOR;
2843 		break;
2844 	case cpu_to_le16(IEEE80211_STYPE_PROBE_REQ):
2845 		/* process only for ibss and mesh */
2846 		if (sdata->vif.type != NL80211_IFTYPE_ADHOC &&
2847 		    sdata->vif.type != NL80211_IFTYPE_MESH_POINT)
2848 			return RX_DROP_MONITOR;
2849 		break;
2850 	default:
2851 		return RX_DROP_MONITOR;
2852 	}
2853 
2854 	/* queue up frame and kick off work to process it */
2855 	rx->skb->pkt_type = IEEE80211_SDATA_QUEUE_TYPE_FRAME;
2856 	skb_queue_tail(&sdata->skb_queue, rx->skb);
2857 	ieee80211_queue_work(&rx->local->hw, &sdata->work);
2858 	if (rx->sta)
2859 		rx->sta->rx_packets++;
2860 
2861 	return RX_QUEUED;
2862 }
2863 
2864 /* TODO: use IEEE80211_RX_FRAGMENTED */
2865 static void ieee80211_rx_cooked_monitor(struct ieee80211_rx_data *rx,
2866 					struct ieee80211_rate *rate)
2867 {
2868 	struct ieee80211_sub_if_data *sdata;
2869 	struct ieee80211_local *local = rx->local;
2870 	struct sk_buff *skb = rx->skb, *skb2;
2871 	struct net_device *prev_dev = NULL;
2872 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
2873 	int needed_headroom;
2874 
2875 	/*
2876 	 * If cooked monitor has been processed already, then
2877 	 * don't do it again. If not, set the flag.
2878 	 */
2879 	if (rx->flags & IEEE80211_RX_CMNTR)
2880 		goto out_free_skb;
2881 	rx->flags |= IEEE80211_RX_CMNTR;
2882 
2883 	/* If there are no cooked monitor interfaces, just free the SKB */
2884 	if (!local->cooked_mntrs)
2885 		goto out_free_skb;
2886 
2887 	/* room for the radiotap header based on driver features */
2888 	needed_headroom = ieee80211_rx_radiotap_space(local, status);
2889 
2890 	if (skb_headroom(skb) < needed_headroom &&
2891 	    pskb_expand_head(skb, needed_headroom, 0, GFP_ATOMIC))
2892 		goto out_free_skb;
2893 
2894 	/* prepend radiotap information */
2895 	ieee80211_add_rx_radiotap_header(local, skb, rate, needed_headroom,
2896 					 false);
2897 
2898 	skb_set_mac_header(skb, 0);
2899 	skb->ip_summed = CHECKSUM_UNNECESSARY;
2900 	skb->pkt_type = PACKET_OTHERHOST;
2901 	skb->protocol = htons(ETH_P_802_2);
2902 
2903 	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
2904 		if (!ieee80211_sdata_running(sdata))
2905 			continue;
2906 
2907 		if (sdata->vif.type != NL80211_IFTYPE_MONITOR ||
2908 		    !(sdata->u.mntr_flags & MONITOR_FLAG_COOK_FRAMES))
2909 			continue;
2910 
2911 		if (prev_dev) {
2912 			skb2 = skb_clone(skb, GFP_ATOMIC);
2913 			if (skb2) {
2914 				skb2->dev = prev_dev;
2915 				netif_receive_skb(skb2);
2916 			}
2917 		}
2918 
2919 		prev_dev = sdata->dev;
2920 		sdata->dev->stats.rx_packets++;
2921 		sdata->dev->stats.rx_bytes += skb->len;
2922 	}
2923 
2924 	if (prev_dev) {
2925 		skb->dev = prev_dev;
2926 		netif_receive_skb(skb);
2927 		return;
2928 	}
2929 
2930  out_free_skb:
2931 	dev_kfree_skb(skb);
2932 }
2933 
2934 static void ieee80211_rx_handlers_result(struct ieee80211_rx_data *rx,
2935 					 ieee80211_rx_result res)
2936 {
2937 	switch (res) {
2938 	case RX_DROP_MONITOR:
2939 		I802_DEBUG_INC(rx->sdata->local->rx_handlers_drop);
2940 		if (rx->sta)
2941 			rx->sta->rx_dropped++;
2942 		/* fall through */
2943 	case RX_CONTINUE: {
2944 		struct ieee80211_rate *rate = NULL;
2945 		struct ieee80211_supported_band *sband;
2946 		struct ieee80211_rx_status *status;
2947 
2948 		status = IEEE80211_SKB_RXCB((rx->skb));
2949 
2950 		sband = rx->local->hw.wiphy->bands[status->band];
2951 		if (!(status->flag & RX_FLAG_HT) &&
2952 		    !(status->flag & RX_FLAG_VHT))
2953 			rate = &sband->bitrates[status->rate_idx];
2954 
2955 		ieee80211_rx_cooked_monitor(rx, rate);
2956 		break;
2957 		}
2958 	case RX_DROP_UNUSABLE:
2959 		I802_DEBUG_INC(rx->sdata->local->rx_handlers_drop);
2960 		if (rx->sta)
2961 			rx->sta->rx_dropped++;
2962 		dev_kfree_skb(rx->skb);
2963 		break;
2964 	case RX_QUEUED:
2965 		I802_DEBUG_INC(rx->sdata->local->rx_handlers_queued);
2966 		break;
2967 	}
2968 }
2969 
2970 static void ieee80211_rx_handlers(struct ieee80211_rx_data *rx,
2971 				  struct sk_buff_head *frames)
2972 {
2973 	ieee80211_rx_result res = RX_DROP_MONITOR;
2974 	struct sk_buff *skb;
2975 
2976 #define CALL_RXH(rxh)			\
2977 	do {				\
2978 		res = rxh(rx);		\
2979 		if (res != RX_CONTINUE)	\
2980 			goto rxh_next;  \
2981 	} while (0);
2982 
2983 	spin_lock_bh(&rx->local->rx_path_lock);
2984 
2985 	while ((skb = __skb_dequeue(frames))) {
2986 		/*
2987 		 * all the other fields are valid across frames
2988 		 * that belong to an aMPDU since they are on the
2989 		 * same TID from the same station
2990 		 */
2991 		rx->skb = skb;
2992 
2993 		CALL_RXH(ieee80211_rx_h_check_more_data)
2994 		CALL_RXH(ieee80211_rx_h_uapsd_and_pspoll)
2995 		CALL_RXH(ieee80211_rx_h_sta_process)
2996 		CALL_RXH(ieee80211_rx_h_decrypt)
2997 		CALL_RXH(ieee80211_rx_h_defragment)
2998 		CALL_RXH(ieee80211_rx_h_michael_mic_verify)
2999 		/* must be after MMIC verify so header is counted in MPDU mic */
3000 #ifdef CONFIG_MAC80211_MESH
3001 		if (ieee80211_vif_is_mesh(&rx->sdata->vif))
3002 			CALL_RXH(ieee80211_rx_h_mesh_fwding);
3003 #endif
3004 		CALL_RXH(ieee80211_rx_h_amsdu)
3005 		CALL_RXH(ieee80211_rx_h_data)
3006 
3007 		/* special treatment -- needs the queue */
3008 		res = ieee80211_rx_h_ctrl(rx, frames);
3009 		if (res != RX_CONTINUE)
3010 			goto rxh_next;
3011 
3012 		CALL_RXH(ieee80211_rx_h_mgmt_check)
3013 		CALL_RXH(ieee80211_rx_h_action)
3014 		CALL_RXH(ieee80211_rx_h_userspace_mgmt)
3015 		CALL_RXH(ieee80211_rx_h_action_return)
3016 		CALL_RXH(ieee80211_rx_h_mgmt)
3017 
3018  rxh_next:
3019 		ieee80211_rx_handlers_result(rx, res);
3020 
3021 #undef CALL_RXH
3022 	}
3023 
3024 	spin_unlock_bh(&rx->local->rx_path_lock);
3025 }
3026 
3027 static void ieee80211_invoke_rx_handlers(struct ieee80211_rx_data *rx)
3028 {
3029 	struct sk_buff_head reorder_release;
3030 	ieee80211_rx_result res = RX_DROP_MONITOR;
3031 
3032 	__skb_queue_head_init(&reorder_release);
3033 
3034 #define CALL_RXH(rxh)			\
3035 	do {				\
3036 		res = rxh(rx);		\
3037 		if (res != RX_CONTINUE)	\
3038 			goto rxh_next;  \
3039 	} while (0);
3040 
3041 	CALL_RXH(ieee80211_rx_h_check)
3042 
3043 	ieee80211_rx_reorder_ampdu(rx, &reorder_release);
3044 
3045 	ieee80211_rx_handlers(rx, &reorder_release);
3046 	return;
3047 
3048  rxh_next:
3049 	ieee80211_rx_handlers_result(rx, res);
3050 
3051 #undef CALL_RXH
3052 }
3053 
3054 /*
3055  * This function makes calls into the RX path, therefore
3056  * it has to be invoked under RCU read lock.
3057  */
3058 void ieee80211_release_reorder_timeout(struct sta_info *sta, int tid)
3059 {
3060 	struct sk_buff_head frames;
3061 	struct ieee80211_rx_data rx = {
3062 		.sta = sta,
3063 		.sdata = sta->sdata,
3064 		.local = sta->local,
3065 		/* This is OK -- must be QoS data frame */
3066 		.security_idx = tid,
3067 		.seqno_idx = tid,
3068 		.flags = 0,
3069 	};
3070 	struct tid_ampdu_rx *tid_agg_rx;
3071 
3072 	tid_agg_rx = rcu_dereference(sta->ampdu_mlme.tid_rx[tid]);
3073 	if (!tid_agg_rx)
3074 		return;
3075 
3076 	__skb_queue_head_init(&frames);
3077 
3078 	spin_lock(&tid_agg_rx->reorder_lock);
3079 	ieee80211_sta_reorder_release(sta->sdata, tid_agg_rx, &frames);
3080 	spin_unlock(&tid_agg_rx->reorder_lock);
3081 
3082 	ieee80211_rx_handlers(&rx, &frames);
3083 }
3084 
3085 /* main receive path */
3086 
3087 static bool prepare_for_handlers(struct ieee80211_rx_data *rx,
3088 				 struct ieee80211_hdr *hdr)
3089 {
3090 	struct ieee80211_sub_if_data *sdata = rx->sdata;
3091 	struct sk_buff *skb = rx->skb;
3092 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
3093 	u8 *bssid = ieee80211_get_bssid(hdr, skb->len, sdata->vif.type);
3094 	int multicast = is_multicast_ether_addr(hdr->addr1);
3095 
3096 	switch (sdata->vif.type) {
3097 	case NL80211_IFTYPE_STATION:
3098 		if (!bssid && !sdata->u.mgd.use_4addr)
3099 			return false;
3100 		if (!multicast &&
3101 		    !ether_addr_equal(sdata->vif.addr, hdr->addr1)) {
3102 			if (!(sdata->dev->flags & IFF_PROMISC) ||
3103 			    sdata->u.mgd.use_4addr)
3104 				return false;
3105 			status->rx_flags &= ~IEEE80211_RX_RA_MATCH;
3106 		}
3107 		break;
3108 	case NL80211_IFTYPE_ADHOC:
3109 		if (!bssid)
3110 			return false;
3111 		if (ether_addr_equal(sdata->vif.addr, hdr->addr2) ||
3112 		    ether_addr_equal(sdata->u.ibss.bssid, hdr->addr2))
3113 			return false;
3114 		if (ieee80211_is_beacon(hdr->frame_control)) {
3115 			return true;
3116 		} else if (!ieee80211_bssid_match(bssid, sdata->u.ibss.bssid)) {
3117 			return false;
3118 		} else if (!multicast &&
3119 			   !ether_addr_equal(sdata->vif.addr, hdr->addr1)) {
3120 			if (!(sdata->dev->flags & IFF_PROMISC))
3121 				return false;
3122 			status->rx_flags &= ~IEEE80211_RX_RA_MATCH;
3123 		} else if (!rx->sta) {
3124 			int rate_idx;
3125 			if (status->flag & (RX_FLAG_HT | RX_FLAG_VHT))
3126 				rate_idx = 0; /* TODO: HT/VHT rates */
3127 			else
3128 				rate_idx = status->rate_idx;
3129 			ieee80211_ibss_rx_no_sta(sdata, bssid, hdr->addr2,
3130 						 BIT(rate_idx));
3131 		}
3132 		break;
3133 	case NL80211_IFTYPE_MESH_POINT:
3134 		if (!multicast &&
3135 		    !ether_addr_equal(sdata->vif.addr, hdr->addr1)) {
3136 			if (!(sdata->dev->flags & IFF_PROMISC))
3137 				return false;
3138 
3139 			status->rx_flags &= ~IEEE80211_RX_RA_MATCH;
3140 		}
3141 		break;
3142 	case NL80211_IFTYPE_AP_VLAN:
3143 	case NL80211_IFTYPE_AP:
3144 		if (!bssid) {
3145 			if (!ether_addr_equal(sdata->vif.addr, hdr->addr1))
3146 				return false;
3147 		} else if (!ieee80211_bssid_match(bssid, sdata->vif.addr)) {
3148 			/*
3149 			 * Accept public action frames even when the
3150 			 * BSSID doesn't match, this is used for P2P
3151 			 * and location updates. Note that mac80211
3152 			 * itself never looks at these frames.
3153 			 */
3154 			if (!multicast &&
3155 			    !ether_addr_equal(sdata->vif.addr, hdr->addr1))
3156 				return false;
3157 			if (ieee80211_is_public_action(hdr, skb->len))
3158 				return true;
3159 			if (!ieee80211_is_beacon(hdr->frame_control))
3160 				return false;
3161 			status->rx_flags &= ~IEEE80211_RX_RA_MATCH;
3162 		} else if (!ieee80211_has_tods(hdr->frame_control)) {
3163 			/* ignore data frames to TDLS-peers */
3164 			if (ieee80211_is_data(hdr->frame_control))
3165 				return false;
3166 			/* ignore action frames to TDLS-peers */
3167 			if (ieee80211_is_action(hdr->frame_control) &&
3168 			    !ether_addr_equal(bssid, hdr->addr1))
3169 				return false;
3170 		}
3171 		break;
3172 	case NL80211_IFTYPE_WDS:
3173 		if (bssid || !ieee80211_is_data(hdr->frame_control))
3174 			return false;
3175 		if (!ether_addr_equal(sdata->u.wds.remote_addr, hdr->addr2))
3176 			return false;
3177 		break;
3178 	case NL80211_IFTYPE_P2P_DEVICE:
3179 		if (!ieee80211_is_public_action(hdr, skb->len) &&
3180 		    !ieee80211_is_probe_req(hdr->frame_control) &&
3181 		    !ieee80211_is_probe_resp(hdr->frame_control) &&
3182 		    !ieee80211_is_beacon(hdr->frame_control))
3183 			return false;
3184 		if (!ether_addr_equal(sdata->vif.addr, hdr->addr1) &&
3185 		    !multicast)
3186 			status->rx_flags &= ~IEEE80211_RX_RA_MATCH;
3187 		break;
3188 	default:
3189 		/* should never get here */
3190 		WARN_ON_ONCE(1);
3191 		break;
3192 	}
3193 
3194 	return true;
3195 }
3196 
3197 /*
3198  * This function returns whether or not the SKB
3199  * was destined for RX processing or not, which,
3200  * if consume is true, is equivalent to whether
3201  * or not the skb was consumed.
3202  */
3203 static bool ieee80211_prepare_and_rx_handle(struct ieee80211_rx_data *rx,
3204 					    struct sk_buff *skb, bool consume)
3205 {
3206 	struct ieee80211_local *local = rx->local;
3207 	struct ieee80211_sub_if_data *sdata = rx->sdata;
3208 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
3209 	struct ieee80211_hdr *hdr = (void *)skb->data;
3210 
3211 	rx->skb = skb;
3212 	status->rx_flags |= IEEE80211_RX_RA_MATCH;
3213 
3214 	if (!prepare_for_handlers(rx, hdr))
3215 		return false;
3216 
3217 	if (!consume) {
3218 		skb = skb_copy(skb, GFP_ATOMIC);
3219 		if (!skb) {
3220 			if (net_ratelimit())
3221 				wiphy_debug(local->hw.wiphy,
3222 					"failed to copy skb for %s\n",
3223 					sdata->name);
3224 			return true;
3225 		}
3226 
3227 		rx->skb = skb;
3228 	}
3229 
3230 	ieee80211_invoke_rx_handlers(rx);
3231 	return true;
3232 }
3233 
3234 /*
3235  * This is the actual Rx frames handler. as it belongs to Rx path it must
3236  * be called with rcu_read_lock protection.
3237  */
3238 static void __ieee80211_rx_handle_packet(struct ieee80211_hw *hw,
3239 					 struct sk_buff *skb)
3240 {
3241 	struct ieee80211_local *local = hw_to_local(hw);
3242 	struct ieee80211_sub_if_data *sdata;
3243 	struct ieee80211_hdr *hdr;
3244 	__le16 fc;
3245 	struct ieee80211_rx_data rx;
3246 	struct ieee80211_sub_if_data *prev;
3247 	struct sta_info *sta, *tmp, *prev_sta;
3248 	int err = 0;
3249 
3250 	fc = ((struct ieee80211_hdr *)skb->data)->frame_control;
3251 	memset(&rx, 0, sizeof(rx));
3252 	rx.skb = skb;
3253 	rx.local = local;
3254 
3255 	if (ieee80211_is_data(fc) || ieee80211_is_mgmt(fc))
3256 		local->dot11ReceivedFragmentCount++;
3257 
3258 	if (ieee80211_is_mgmt(fc)) {
3259 		/* drop frame if too short for header */
3260 		if (skb->len < ieee80211_hdrlen(fc))
3261 			err = -ENOBUFS;
3262 		else
3263 			err = skb_linearize(skb);
3264 	} else {
3265 		err = !pskb_may_pull(skb, ieee80211_hdrlen(fc));
3266 	}
3267 
3268 	if (err) {
3269 		dev_kfree_skb(skb);
3270 		return;
3271 	}
3272 
3273 	hdr = (struct ieee80211_hdr *)skb->data;
3274 	ieee80211_parse_qos(&rx);
3275 	ieee80211_verify_alignment(&rx);
3276 
3277 	if (unlikely(ieee80211_is_probe_resp(hdr->frame_control) ||
3278 		     ieee80211_is_beacon(hdr->frame_control)))
3279 		ieee80211_scan_rx(local, skb);
3280 
3281 	if (ieee80211_is_data(fc)) {
3282 		prev_sta = NULL;
3283 
3284 		for_each_sta_info(local, hdr->addr2, sta, tmp) {
3285 			if (!prev_sta) {
3286 				prev_sta = sta;
3287 				continue;
3288 			}
3289 
3290 			rx.sta = prev_sta;
3291 			rx.sdata = prev_sta->sdata;
3292 			ieee80211_prepare_and_rx_handle(&rx, skb, false);
3293 
3294 			prev_sta = sta;
3295 		}
3296 
3297 		if (prev_sta) {
3298 			rx.sta = prev_sta;
3299 			rx.sdata = prev_sta->sdata;
3300 
3301 			if (ieee80211_prepare_and_rx_handle(&rx, skb, true))
3302 				return;
3303 			goto out;
3304 		}
3305 	}
3306 
3307 	prev = NULL;
3308 
3309 	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
3310 		if (!ieee80211_sdata_running(sdata))
3311 			continue;
3312 
3313 		if (sdata->vif.type == NL80211_IFTYPE_MONITOR ||
3314 		    sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
3315 			continue;
3316 
3317 		/*
3318 		 * frame is destined for this interface, but if it's
3319 		 * not also for the previous one we handle that after
3320 		 * the loop to avoid copying the SKB once too much
3321 		 */
3322 
3323 		if (!prev) {
3324 			prev = sdata;
3325 			continue;
3326 		}
3327 
3328 		rx.sta = sta_info_get_bss(prev, hdr->addr2);
3329 		rx.sdata = prev;
3330 		ieee80211_prepare_and_rx_handle(&rx, skb, false);
3331 
3332 		prev = sdata;
3333 	}
3334 
3335 	if (prev) {
3336 		rx.sta = sta_info_get_bss(prev, hdr->addr2);
3337 		rx.sdata = prev;
3338 
3339 		if (ieee80211_prepare_and_rx_handle(&rx, skb, true))
3340 			return;
3341 	}
3342 
3343  out:
3344 	dev_kfree_skb(skb);
3345 }
3346 
3347 /*
3348  * This is the receive path handler. It is called by a low level driver when an
3349  * 802.11 MPDU is received from the hardware.
3350  */
3351 void ieee80211_rx(struct ieee80211_hw *hw, struct sk_buff *skb)
3352 {
3353 	struct ieee80211_local *local = hw_to_local(hw);
3354 	struct ieee80211_rate *rate = NULL;
3355 	struct ieee80211_supported_band *sband;
3356 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
3357 
3358 	WARN_ON_ONCE(softirq_count() == 0);
3359 
3360 	if (WARN_ON(status->band >= IEEE80211_NUM_BANDS))
3361 		goto drop;
3362 
3363 	sband = local->hw.wiphy->bands[status->band];
3364 	if (WARN_ON(!sband))
3365 		goto drop;
3366 
3367 	/*
3368 	 * If we're suspending, it is possible although not too likely
3369 	 * that we'd be receiving frames after having already partially
3370 	 * quiesced the stack. We can't process such frames then since
3371 	 * that might, for example, cause stations to be added or other
3372 	 * driver callbacks be invoked.
3373 	 */
3374 	if (unlikely(local->quiescing || local->suspended))
3375 		goto drop;
3376 
3377 	/* We might be during a HW reconfig, prevent Rx for the same reason */
3378 	if (unlikely(local->in_reconfig))
3379 		goto drop;
3380 
3381 	/*
3382 	 * The same happens when we're not even started,
3383 	 * but that's worth a warning.
3384 	 */
3385 	if (WARN_ON(!local->started))
3386 		goto drop;
3387 
3388 	if (likely(!(status->flag & RX_FLAG_FAILED_PLCP_CRC))) {
3389 		/*
3390 		 * Validate the rate, unless a PLCP error means that
3391 		 * we probably can't have a valid rate here anyway.
3392 		 */
3393 
3394 		if (status->flag & RX_FLAG_HT) {
3395 			/*
3396 			 * rate_idx is MCS index, which can be [0-76]
3397 			 * as documented on:
3398 			 *
3399 			 * http://wireless.kernel.org/en/developers/Documentation/ieee80211/802.11n
3400 			 *
3401 			 * Anything else would be some sort of driver or
3402 			 * hardware error. The driver should catch hardware
3403 			 * errors.
3404 			 */
3405 			if (WARN(status->rate_idx > 76,
3406 				 "Rate marked as an HT rate but passed "
3407 				 "status->rate_idx is not "
3408 				 "an MCS index [0-76]: %d (0x%02x)\n",
3409 				 status->rate_idx,
3410 				 status->rate_idx))
3411 				goto drop;
3412 		} else if (status->flag & RX_FLAG_VHT) {
3413 			if (WARN_ONCE(status->rate_idx > 9 ||
3414 				      !status->vht_nss ||
3415 				      status->vht_nss > 8,
3416 				      "Rate marked as a VHT rate but data is invalid: MCS: %d, NSS: %d\n",
3417 				      status->rate_idx, status->vht_nss))
3418 				goto drop;
3419 		} else {
3420 			if (WARN_ON(status->rate_idx >= sband->n_bitrates))
3421 				goto drop;
3422 			rate = &sband->bitrates[status->rate_idx];
3423 		}
3424 	}
3425 
3426 	status->rx_flags = 0;
3427 
3428 	/*
3429 	 * key references and virtual interfaces are protected using RCU
3430 	 * and this requires that we are in a read-side RCU section during
3431 	 * receive processing
3432 	 */
3433 	rcu_read_lock();
3434 
3435 	/*
3436 	 * Frames with failed FCS/PLCP checksum are not returned,
3437 	 * all other frames are returned without radiotap header
3438 	 * if it was previously present.
3439 	 * Also, frames with less than 16 bytes are dropped.
3440 	 */
3441 	skb = ieee80211_rx_monitor(local, skb, rate);
3442 	if (!skb) {
3443 		rcu_read_unlock();
3444 		return;
3445 	}
3446 
3447 	ieee80211_tpt_led_trig_rx(local,
3448 			((struct ieee80211_hdr *)skb->data)->frame_control,
3449 			skb->len);
3450 	__ieee80211_rx_handle_packet(hw, skb);
3451 
3452 	rcu_read_unlock();
3453 
3454 	return;
3455  drop:
3456 	kfree_skb(skb);
3457 }
3458 EXPORT_SYMBOL(ieee80211_rx);
3459 
3460 /* This is a version of the rx handler that can be called from hard irq
3461  * context. Post the skb on the queue and schedule the tasklet */
3462 void ieee80211_rx_irqsafe(struct ieee80211_hw *hw, struct sk_buff *skb)
3463 {
3464 	struct ieee80211_local *local = hw_to_local(hw);
3465 
3466 	BUILD_BUG_ON(sizeof(struct ieee80211_rx_status) > sizeof(skb->cb));
3467 
3468 	skb->pkt_type = IEEE80211_RX_MSG;
3469 	skb_queue_tail(&local->skb_queue, skb);
3470 	tasklet_schedule(&local->tasklet);
3471 }
3472 EXPORT_SYMBOL(ieee80211_rx_irqsafe);
3473