xref: /openbmc/linux/net/mac80211/rx.c (revision 54cbac81)
1 /*
2  * Copyright 2002-2005, Instant802 Networks, Inc.
3  * Copyright 2005-2006, Devicescape Software, Inc.
4  * Copyright 2006-2007	Jiri Benc <jbenc@suse.cz>
5  * Copyright 2007-2010	Johannes Berg <johannes@sipsolutions.net>
6  *
7  * This program is free software; you can redistribute it and/or modify
8  * it under the terms of the GNU General Public License version 2 as
9  * published by the Free Software Foundation.
10  */
11 
12 #include <linux/jiffies.h>
13 #include <linux/slab.h>
14 #include <linux/kernel.h>
15 #include <linux/skbuff.h>
16 #include <linux/netdevice.h>
17 #include <linux/etherdevice.h>
18 #include <linux/rcupdate.h>
19 #include <linux/export.h>
20 #include <net/mac80211.h>
21 #include <net/ieee80211_radiotap.h>
22 #include <asm/unaligned.h>
23 
24 #include "ieee80211_i.h"
25 #include "driver-ops.h"
26 #include "led.h"
27 #include "mesh.h"
28 #include "wep.h"
29 #include "wpa.h"
30 #include "tkip.h"
31 #include "wme.h"
32 #include "rate.h"
33 
34 /*
35  * monitor mode reception
36  *
37  * This function cleans up the SKB, i.e. it removes all the stuff
38  * only useful for monitoring.
39  */
40 static struct sk_buff *remove_monitor_info(struct ieee80211_local *local,
41 					   struct sk_buff *skb)
42 {
43 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
44 
45 	if (local->hw.flags & IEEE80211_HW_RX_INCLUDES_FCS) {
46 		if (likely(skb->len > FCS_LEN))
47 			__pskb_trim(skb, skb->len - FCS_LEN);
48 		else {
49 			/* driver bug */
50 			WARN_ON(1);
51 			dev_kfree_skb(skb);
52 			return NULL;
53 		}
54 	}
55 
56 	if (status->vendor_radiotap_len)
57 		__pskb_pull(skb, status->vendor_radiotap_len);
58 
59 	return skb;
60 }
61 
62 static inline int should_drop_frame(struct sk_buff *skb, int present_fcs_len)
63 {
64 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
65 	struct ieee80211_hdr *hdr;
66 
67 	hdr = (void *)(skb->data + status->vendor_radiotap_len);
68 
69 	if (status->flag & (RX_FLAG_FAILED_FCS_CRC |
70 			    RX_FLAG_FAILED_PLCP_CRC |
71 			    RX_FLAG_AMPDU_IS_ZEROLEN))
72 		return 1;
73 	if (unlikely(skb->len < 16 + present_fcs_len +
74 				status->vendor_radiotap_len))
75 		return 1;
76 	if (ieee80211_is_ctl(hdr->frame_control) &&
77 	    !ieee80211_is_pspoll(hdr->frame_control) &&
78 	    !ieee80211_is_back_req(hdr->frame_control))
79 		return 1;
80 	return 0;
81 }
82 
83 static int
84 ieee80211_rx_radiotap_space(struct ieee80211_local *local,
85 			    struct ieee80211_rx_status *status)
86 {
87 	int len;
88 
89 	/* always present fields */
90 	len = sizeof(struct ieee80211_radiotap_header) + 9;
91 
92 	/* allocate extra bitmap */
93 	if (status->vendor_radiotap_len)
94 		len += 4;
95 
96 	if (ieee80211_have_rx_timestamp(status)) {
97 		len = ALIGN(len, 8);
98 		len += 8;
99 	}
100 	if (local->hw.flags & IEEE80211_HW_SIGNAL_DBM)
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->vendor_radiotap_len) {
120 		if (WARN_ON_ONCE(status->vendor_radiotap_align == 0))
121 			status->vendor_radiotap_align = 1;
122 		/* align standard part of vendor namespace */
123 		len = ALIGN(len, 2);
124 		/* allocate standard part of vendor namespace */
125 		len += 6;
126 		/* align vendor-defined part */
127 		len = ALIGN(len, status->vendor_radiotap_align);
128 		/* vendor-defined part is already in skb */
129 	}
130 
131 	return len;
132 }
133 
134 /*
135  * ieee80211_add_rx_radiotap_header - add radiotap header
136  *
137  * add a radiotap header containing all the fields which the hardware provided.
138  */
139 static void
140 ieee80211_add_rx_radiotap_header(struct ieee80211_local *local,
141 				 struct sk_buff *skb,
142 				 struct ieee80211_rate *rate,
143 				 int rtap_len, bool has_fcs)
144 {
145 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
146 	struct ieee80211_radiotap_header *rthdr;
147 	unsigned char *pos;
148 	u16 rx_flags = 0;
149 	int mpdulen;
150 
151 	mpdulen = skb->len;
152 	if (!(has_fcs && (local->hw.flags & IEEE80211_HW_RX_INCLUDES_FCS)))
153 		mpdulen += FCS_LEN;
154 
155 	rthdr = (struct ieee80211_radiotap_header *)skb_push(skb, rtap_len);
156 	memset(rthdr, 0, rtap_len);
157 
158 	/* radiotap header, set always present flags */
159 	rthdr->it_present =
160 		cpu_to_le32((1 << IEEE80211_RADIOTAP_FLAGS) |
161 			    (1 << IEEE80211_RADIOTAP_CHANNEL) |
162 			    (1 << IEEE80211_RADIOTAP_ANTENNA) |
163 			    (1 << IEEE80211_RADIOTAP_RX_FLAGS));
164 	rthdr->it_len = cpu_to_le16(rtap_len + status->vendor_radiotap_len);
165 
166 	pos = (unsigned char *)(rthdr + 1);
167 
168 	if (status->vendor_radiotap_len) {
169 		rthdr->it_present |=
170 			cpu_to_le32(BIT(IEEE80211_RADIOTAP_VENDOR_NAMESPACE)) |
171 			cpu_to_le32(BIT(IEEE80211_RADIOTAP_EXT));
172 		put_unaligned_le32(status->vendor_radiotap_bitmap, pos);
173 		pos += 4;
174 	}
175 
176 	/* the order of the following fields is important */
177 
178 	/* IEEE80211_RADIOTAP_TSFT */
179 	if (ieee80211_have_rx_timestamp(status)) {
180 		/* padding */
181 		while ((pos - (u8 *)rthdr) & 7)
182 			*pos++ = 0;
183 		put_unaligned_le64(
184 			ieee80211_calculate_rx_timestamp(local, status,
185 							 mpdulen, 0),
186 			pos);
187 		rthdr->it_present |= cpu_to_le32(1 << IEEE80211_RADIOTAP_TSFT);
188 		pos += 8;
189 	}
190 
191 	/* IEEE80211_RADIOTAP_FLAGS */
192 	if (has_fcs && (local->hw.flags & IEEE80211_HW_RX_INCLUDES_FCS))
193 		*pos |= IEEE80211_RADIOTAP_F_FCS;
194 	if (status->flag & (RX_FLAG_FAILED_FCS_CRC | RX_FLAG_FAILED_PLCP_CRC))
195 		*pos |= IEEE80211_RADIOTAP_F_BADFCS;
196 	if (status->flag & RX_FLAG_SHORTPRE)
197 		*pos |= IEEE80211_RADIOTAP_F_SHORTPRE;
198 	pos++;
199 
200 	/* IEEE80211_RADIOTAP_RATE */
201 	if (!rate || status->flag & (RX_FLAG_HT | RX_FLAG_VHT)) {
202 		/*
203 		 * Without rate information don't add it. If we have,
204 		 * MCS information is a separate field in radiotap,
205 		 * added below. The byte here is needed as padding
206 		 * for the channel though, so initialise it to 0.
207 		 */
208 		*pos = 0;
209 	} else {
210 		rthdr->it_present |= cpu_to_le32(1 << IEEE80211_RADIOTAP_RATE);
211 		*pos = rate->bitrate / 5;
212 	}
213 	pos++;
214 
215 	/* IEEE80211_RADIOTAP_CHANNEL */
216 	put_unaligned_le16(status->freq, pos);
217 	pos += 2;
218 	if (status->band == IEEE80211_BAND_5GHZ)
219 		put_unaligned_le16(IEEE80211_CHAN_OFDM | IEEE80211_CHAN_5GHZ,
220 				   pos);
221 	else if (status->flag & (RX_FLAG_HT | RX_FLAG_VHT))
222 		put_unaligned_le16(IEEE80211_CHAN_DYN | IEEE80211_CHAN_2GHZ,
223 				   pos);
224 	else if (rate && rate->flags & IEEE80211_RATE_ERP_G)
225 		put_unaligned_le16(IEEE80211_CHAN_OFDM | IEEE80211_CHAN_2GHZ,
226 				   pos);
227 	else if (rate)
228 		put_unaligned_le16(IEEE80211_CHAN_CCK | IEEE80211_CHAN_2GHZ,
229 				   pos);
230 	else
231 		put_unaligned_le16(IEEE80211_CHAN_2GHZ, pos);
232 	pos += 2;
233 
234 	/* IEEE80211_RADIOTAP_DBM_ANTSIGNAL */
235 	if (local->hw.flags & IEEE80211_HW_SIGNAL_DBM &&
236 	    !(status->flag & RX_FLAG_NO_SIGNAL_VAL)) {
237 		*pos = status->signal;
238 		rthdr->it_present |=
239 			cpu_to_le32(1 << IEEE80211_RADIOTAP_DBM_ANTSIGNAL);
240 		pos++;
241 	}
242 
243 	/* IEEE80211_RADIOTAP_LOCK_QUALITY is missing */
244 
245 	/* IEEE80211_RADIOTAP_ANTENNA */
246 	*pos = status->antenna;
247 	pos++;
248 
249 	/* IEEE80211_RADIOTAP_DB_ANTNOISE is not used */
250 
251 	/* IEEE80211_RADIOTAP_RX_FLAGS */
252 	/* ensure 2 byte alignment for the 2 byte field as required */
253 	if ((pos - (u8 *)rthdr) & 1)
254 		*pos++ = 0;
255 	if (status->flag & RX_FLAG_FAILED_PLCP_CRC)
256 		rx_flags |= IEEE80211_RADIOTAP_F_RX_BADPLCP;
257 	put_unaligned_le16(rx_flags, pos);
258 	pos += 2;
259 
260 	if (status->flag & RX_FLAG_HT) {
261 		rthdr->it_present |= cpu_to_le32(1 << IEEE80211_RADIOTAP_MCS);
262 		*pos++ = local->hw.radiotap_mcs_details;
263 		*pos = 0;
264 		if (status->flag & RX_FLAG_SHORT_GI)
265 			*pos |= IEEE80211_RADIOTAP_MCS_SGI;
266 		if (status->flag & RX_FLAG_40MHZ)
267 			*pos |= IEEE80211_RADIOTAP_MCS_BW_40;
268 		if (status->flag & RX_FLAG_HT_GF)
269 			*pos |= IEEE80211_RADIOTAP_MCS_FMT_GF;
270 		pos++;
271 		*pos++ = status->rate_idx;
272 	}
273 
274 	if (status->flag & RX_FLAG_AMPDU_DETAILS) {
275 		u16 flags = 0;
276 
277 		/* ensure 4 byte alignment */
278 		while ((pos - (u8 *)rthdr) & 3)
279 			pos++;
280 		rthdr->it_present |=
281 			cpu_to_le32(1 << IEEE80211_RADIOTAP_AMPDU_STATUS);
282 		put_unaligned_le32(status->ampdu_reference, pos);
283 		pos += 4;
284 		if (status->flag & RX_FLAG_AMPDU_REPORT_ZEROLEN)
285 			flags |= IEEE80211_RADIOTAP_AMPDU_REPORT_ZEROLEN;
286 		if (status->flag & RX_FLAG_AMPDU_IS_ZEROLEN)
287 			flags |= IEEE80211_RADIOTAP_AMPDU_IS_ZEROLEN;
288 		if (status->flag & RX_FLAG_AMPDU_LAST_KNOWN)
289 			flags |= IEEE80211_RADIOTAP_AMPDU_LAST_KNOWN;
290 		if (status->flag & RX_FLAG_AMPDU_IS_LAST)
291 			flags |= IEEE80211_RADIOTAP_AMPDU_IS_LAST;
292 		if (status->flag & RX_FLAG_AMPDU_DELIM_CRC_ERROR)
293 			flags |= IEEE80211_RADIOTAP_AMPDU_DELIM_CRC_ERR;
294 		if (status->flag & RX_FLAG_AMPDU_DELIM_CRC_KNOWN)
295 			flags |= IEEE80211_RADIOTAP_AMPDU_DELIM_CRC_KNOWN;
296 		put_unaligned_le16(flags, pos);
297 		pos += 2;
298 		if (status->flag & RX_FLAG_AMPDU_DELIM_CRC_KNOWN)
299 			*pos++ = status->ampdu_delimiter_crc;
300 		else
301 			*pos++ = 0;
302 		*pos++ = 0;
303 	}
304 
305 	if (status->flag & RX_FLAG_VHT) {
306 		u16 known = local->hw.radiotap_vht_details;
307 
308 		rthdr->it_present |= cpu_to_le32(1 << IEEE80211_RADIOTAP_VHT);
309 		/* known field - how to handle 80+80? */
310 		if (status->flag & RX_FLAG_80P80MHZ)
311 			known &= ~IEEE80211_RADIOTAP_VHT_KNOWN_BANDWIDTH;
312 		put_unaligned_le16(known, pos);
313 		pos += 2;
314 		/* flags */
315 		if (status->flag & RX_FLAG_SHORT_GI)
316 			*pos |= IEEE80211_RADIOTAP_VHT_FLAG_SGI;
317 		pos++;
318 		/* bandwidth */
319 		if (status->flag & RX_FLAG_80MHZ)
320 			*pos++ = 4;
321 		else if (status->flag & RX_FLAG_80P80MHZ)
322 			*pos++ = 0; /* marked not known above */
323 		else if (status->flag & RX_FLAG_160MHZ)
324 			*pos++ = 11;
325 		else if (status->flag & RX_FLAG_40MHZ)
326 			*pos++ = 1;
327 		else /* 20 MHz */
328 			*pos++ = 0;
329 		/* MCS/NSS */
330 		*pos = (status->rate_idx << 4) | status->vht_nss;
331 		pos += 4;
332 		/* coding field */
333 		pos++;
334 		/* group ID */
335 		pos++;
336 		/* partial_aid */
337 		pos += 2;
338 	}
339 
340 	if (status->vendor_radiotap_len) {
341 		/* ensure 2 byte alignment for the vendor field as required */
342 		if ((pos - (u8 *)rthdr) & 1)
343 			*pos++ = 0;
344 		*pos++ = status->vendor_radiotap_oui[0];
345 		*pos++ = status->vendor_radiotap_oui[1];
346 		*pos++ = status->vendor_radiotap_oui[2];
347 		*pos++ = status->vendor_radiotap_subns;
348 		put_unaligned_le16(status->vendor_radiotap_len, pos);
349 		pos += 2;
350 		/* align the actual payload as requested */
351 		while ((pos - (u8 *)rthdr) & (status->vendor_radiotap_align - 1))
352 			*pos++ = 0;
353 	}
354 }
355 
356 /*
357  * This function copies a received frame to all monitor interfaces and
358  * returns a cleaned-up SKB that no longer includes the FCS nor the
359  * radiotap header the driver might have added.
360  */
361 static struct sk_buff *
362 ieee80211_rx_monitor(struct ieee80211_local *local, struct sk_buff *origskb,
363 		     struct ieee80211_rate *rate)
364 {
365 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(origskb);
366 	struct ieee80211_sub_if_data *sdata;
367 	int needed_headroom;
368 	struct sk_buff *skb, *skb2;
369 	struct net_device *prev_dev = NULL;
370 	int present_fcs_len = 0;
371 
372 	/*
373 	 * First, we may need to make a copy of the skb because
374 	 *  (1) we need to modify it for radiotap (if not present), and
375 	 *  (2) the other RX handlers will modify the skb we got.
376 	 *
377 	 * We don't need to, of course, if we aren't going to return
378 	 * the SKB because it has a bad FCS/PLCP checksum.
379 	 */
380 
381 	if (local->hw.flags & IEEE80211_HW_RX_INCLUDES_FCS)
382 		present_fcs_len = FCS_LEN;
383 
384 	/* ensure hdr->frame_control and vendor radiotap data are in skb head */
385 	if (!pskb_may_pull(origskb, 2 + status->vendor_radiotap_len)) {
386 		dev_kfree_skb(origskb);
387 		return NULL;
388 	}
389 
390 	if (!local->monitors) {
391 		if (should_drop_frame(origskb, present_fcs_len)) {
392 			dev_kfree_skb(origskb);
393 			return NULL;
394 		}
395 
396 		return remove_monitor_info(local, origskb);
397 	}
398 
399 	/* room for the radiotap header based on driver features */
400 	needed_headroom = ieee80211_rx_radiotap_space(local, status);
401 
402 	if (should_drop_frame(origskb, present_fcs_len)) {
403 		/* only need to expand headroom if necessary */
404 		skb = origskb;
405 		origskb = NULL;
406 
407 		/*
408 		 * This shouldn't trigger often because most devices have an
409 		 * RX header they pull before we get here, and that should
410 		 * be big enough for our radiotap information. We should
411 		 * probably export the length to drivers so that we can have
412 		 * them allocate enough headroom to start with.
413 		 */
414 		if (skb_headroom(skb) < needed_headroom &&
415 		    pskb_expand_head(skb, needed_headroom, 0, GFP_ATOMIC)) {
416 			dev_kfree_skb(skb);
417 			return NULL;
418 		}
419 	} else {
420 		/*
421 		 * Need to make a copy and possibly remove radiotap header
422 		 * and FCS from the original.
423 		 */
424 		skb = skb_copy_expand(origskb, needed_headroom, 0, GFP_ATOMIC);
425 
426 		origskb = remove_monitor_info(local, origskb);
427 
428 		if (!skb)
429 			return origskb;
430 	}
431 
432 	/* prepend radiotap information */
433 	ieee80211_add_rx_radiotap_header(local, skb, rate, needed_headroom,
434 					 true);
435 
436 	skb_reset_mac_header(skb);
437 	skb->ip_summed = CHECKSUM_UNNECESSARY;
438 	skb->pkt_type = PACKET_OTHERHOST;
439 	skb->protocol = htons(ETH_P_802_2);
440 
441 	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
442 		if (sdata->vif.type != NL80211_IFTYPE_MONITOR)
443 			continue;
444 
445 		if (sdata->u.mntr_flags & MONITOR_FLAG_COOK_FRAMES)
446 			continue;
447 
448 		if (!ieee80211_sdata_running(sdata))
449 			continue;
450 
451 		if (prev_dev) {
452 			skb2 = skb_clone(skb, GFP_ATOMIC);
453 			if (skb2) {
454 				skb2->dev = prev_dev;
455 				netif_receive_skb(skb2);
456 			}
457 		}
458 
459 		prev_dev = sdata->dev;
460 		sdata->dev->stats.rx_packets++;
461 		sdata->dev->stats.rx_bytes += skb->len;
462 	}
463 
464 	if (prev_dev) {
465 		skb->dev = prev_dev;
466 		netif_receive_skb(skb);
467 	} else
468 		dev_kfree_skb(skb);
469 
470 	return origskb;
471 }
472 
473 static void ieee80211_parse_qos(struct ieee80211_rx_data *rx)
474 {
475 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
476 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
477 	int tid, seqno_idx, security_idx;
478 
479 	/* does the frame have a qos control field? */
480 	if (ieee80211_is_data_qos(hdr->frame_control)) {
481 		u8 *qc = ieee80211_get_qos_ctl(hdr);
482 		/* frame has qos control */
483 		tid = *qc & IEEE80211_QOS_CTL_TID_MASK;
484 		if (*qc & IEEE80211_QOS_CTL_A_MSDU_PRESENT)
485 			status->rx_flags |= IEEE80211_RX_AMSDU;
486 
487 		seqno_idx = tid;
488 		security_idx = tid;
489 	} else {
490 		/*
491 		 * IEEE 802.11-2007, 7.1.3.4.1 ("Sequence Number field"):
492 		 *
493 		 *	Sequence numbers for management frames, QoS data
494 		 *	frames with a broadcast/multicast address in the
495 		 *	Address 1 field, and all non-QoS data frames sent
496 		 *	by QoS STAs are assigned using an additional single
497 		 *	modulo-4096 counter, [...]
498 		 *
499 		 * We also use that counter for non-QoS STAs.
500 		 */
501 		seqno_idx = IEEE80211_NUM_TIDS;
502 		security_idx = 0;
503 		if (ieee80211_is_mgmt(hdr->frame_control))
504 			security_idx = IEEE80211_NUM_TIDS;
505 		tid = 0;
506 	}
507 
508 	rx->seqno_idx = seqno_idx;
509 	rx->security_idx = security_idx;
510 	/* Set skb->priority to 1d tag if highest order bit of TID is not set.
511 	 * For now, set skb->priority to 0 for other cases. */
512 	rx->skb->priority = (tid > 7) ? 0 : tid;
513 }
514 
515 /**
516  * DOC: Packet alignment
517  *
518  * Drivers always need to pass packets that are aligned to two-byte boundaries
519  * to the stack.
520  *
521  * Additionally, should, if possible, align the payload data in a way that
522  * guarantees that the contained IP header is aligned to a four-byte
523  * boundary. In the case of regular frames, this simply means aligning the
524  * payload to a four-byte boundary (because either the IP header is directly
525  * contained, or IV/RFC1042 headers that have a length divisible by four are
526  * in front of it).  If the payload data is not properly aligned and the
527  * architecture doesn't support efficient unaligned operations, mac80211
528  * will align the data.
529  *
530  * With A-MSDU frames, however, the payload data address must yield two modulo
531  * four because there are 14-byte 802.3 headers within the A-MSDU frames that
532  * push the IP header further back to a multiple of four again. Thankfully, the
533  * specs were sane enough this time around to require padding each A-MSDU
534  * subframe to a length that is a multiple of four.
535  *
536  * Padding like Atheros hardware adds which is between the 802.11 header and
537  * the payload is not supported, the driver is required to move the 802.11
538  * header to be directly in front of the payload in that case.
539  */
540 static void ieee80211_verify_alignment(struct ieee80211_rx_data *rx)
541 {
542 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG
543 	WARN_ONCE((unsigned long)rx->skb->data & 1,
544 		  "unaligned packet at 0x%p\n", rx->skb->data);
545 #endif
546 }
547 
548 
549 /* rx handlers */
550 
551 static int ieee80211_is_unicast_robust_mgmt_frame(struct sk_buff *skb)
552 {
553 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
554 
555 	if (skb->len < 24 || is_multicast_ether_addr(hdr->addr1))
556 		return 0;
557 
558 	return ieee80211_is_robust_mgmt_frame(hdr);
559 }
560 
561 
562 static int ieee80211_is_multicast_robust_mgmt_frame(struct sk_buff *skb)
563 {
564 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
565 
566 	if (skb->len < 24 || !is_multicast_ether_addr(hdr->addr1))
567 		return 0;
568 
569 	return ieee80211_is_robust_mgmt_frame(hdr);
570 }
571 
572 
573 /* Get the BIP key index from MMIE; return -1 if this is not a BIP frame */
574 static int ieee80211_get_mmie_keyidx(struct sk_buff *skb)
575 {
576 	struct ieee80211_mgmt *hdr = (struct ieee80211_mgmt *) skb->data;
577 	struct ieee80211_mmie *mmie;
578 
579 	if (skb->len < 24 + sizeof(*mmie) || !is_multicast_ether_addr(hdr->da))
580 		return -1;
581 
582 	if (!ieee80211_is_robust_mgmt_frame((struct ieee80211_hdr *) hdr))
583 		return -1; /* not a robust management frame */
584 
585 	mmie = (struct ieee80211_mmie *)
586 		(skb->data + skb->len - sizeof(*mmie));
587 	if (mmie->element_id != WLAN_EID_MMIE ||
588 	    mmie->length != sizeof(*mmie) - 2)
589 		return -1;
590 
591 	return le16_to_cpu(mmie->key_id);
592 }
593 
594 static ieee80211_rx_result ieee80211_rx_mesh_check(struct ieee80211_rx_data *rx)
595 {
596 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
597 	char *dev_addr = rx->sdata->vif.addr;
598 
599 	if (ieee80211_is_data(hdr->frame_control)) {
600 		if (is_multicast_ether_addr(hdr->addr1)) {
601 			if (ieee80211_has_tods(hdr->frame_control) ||
602 			    !ieee80211_has_fromds(hdr->frame_control))
603 				return RX_DROP_MONITOR;
604 			if (ether_addr_equal(hdr->addr3, dev_addr))
605 				return RX_DROP_MONITOR;
606 		} else {
607 			if (!ieee80211_has_a4(hdr->frame_control))
608 				return RX_DROP_MONITOR;
609 			if (ether_addr_equal(hdr->addr4, dev_addr))
610 				return RX_DROP_MONITOR;
611 		}
612 	}
613 
614 	/* If there is not an established peer link and this is not a peer link
615 	 * establisment frame, beacon or probe, drop the frame.
616 	 */
617 
618 	if (!rx->sta || sta_plink_state(rx->sta) != NL80211_PLINK_ESTAB) {
619 		struct ieee80211_mgmt *mgmt;
620 
621 		if (!ieee80211_is_mgmt(hdr->frame_control))
622 			return RX_DROP_MONITOR;
623 
624 		if (ieee80211_is_action(hdr->frame_control)) {
625 			u8 category;
626 
627 			/* make sure category field is present */
628 			if (rx->skb->len < IEEE80211_MIN_ACTION_SIZE)
629 				return RX_DROP_MONITOR;
630 
631 			mgmt = (struct ieee80211_mgmt *)hdr;
632 			category = mgmt->u.action.category;
633 			if (category != WLAN_CATEGORY_MESH_ACTION &&
634 			    category != WLAN_CATEGORY_SELF_PROTECTED)
635 				return RX_DROP_MONITOR;
636 			return RX_CONTINUE;
637 		}
638 
639 		if (ieee80211_is_probe_req(hdr->frame_control) ||
640 		    ieee80211_is_probe_resp(hdr->frame_control) ||
641 		    ieee80211_is_beacon(hdr->frame_control) ||
642 		    ieee80211_is_auth(hdr->frame_control))
643 			return RX_CONTINUE;
644 
645 		return RX_DROP_MONITOR;
646 	}
647 
648 	return RX_CONTINUE;
649 }
650 
651 #define SEQ_MODULO 0x1000
652 #define SEQ_MASK   0xfff
653 
654 static inline int seq_less(u16 sq1, u16 sq2)
655 {
656 	return ((sq1 - sq2) & SEQ_MASK) > (SEQ_MODULO >> 1);
657 }
658 
659 static inline u16 seq_inc(u16 sq)
660 {
661 	return (sq + 1) & SEQ_MASK;
662 }
663 
664 static inline u16 seq_sub(u16 sq1, u16 sq2)
665 {
666 	return (sq1 - sq2) & SEQ_MASK;
667 }
668 
669 static void ieee80211_release_reorder_frame(struct ieee80211_sub_if_data *sdata,
670 					    struct tid_ampdu_rx *tid_agg_rx,
671 					    int index)
672 {
673 	struct ieee80211_local *local = sdata->local;
674 	struct sk_buff *skb = tid_agg_rx->reorder_buf[index];
675 	struct ieee80211_rx_status *status;
676 
677 	lockdep_assert_held(&tid_agg_rx->reorder_lock);
678 
679 	if (!skb)
680 		goto no_frame;
681 
682 	/* release the frame from the reorder ring buffer */
683 	tid_agg_rx->stored_mpdu_num--;
684 	tid_agg_rx->reorder_buf[index] = NULL;
685 	status = IEEE80211_SKB_RXCB(skb);
686 	status->rx_flags |= IEEE80211_RX_DEFERRED_RELEASE;
687 	skb_queue_tail(&local->rx_skb_queue, skb);
688 
689 no_frame:
690 	tid_agg_rx->head_seq_num = seq_inc(tid_agg_rx->head_seq_num);
691 }
692 
693 static void ieee80211_release_reorder_frames(struct ieee80211_sub_if_data *sdata,
694 					     struct tid_ampdu_rx *tid_agg_rx,
695 					     u16 head_seq_num)
696 {
697 	int index;
698 
699 	lockdep_assert_held(&tid_agg_rx->reorder_lock);
700 
701 	while (seq_less(tid_agg_rx->head_seq_num, head_seq_num)) {
702 		index = seq_sub(tid_agg_rx->head_seq_num, tid_agg_rx->ssn) %
703 							tid_agg_rx->buf_size;
704 		ieee80211_release_reorder_frame(sdata, tid_agg_rx, index);
705 	}
706 }
707 
708 /*
709  * Timeout (in jiffies) for skb's that are waiting in the RX reorder buffer. If
710  * the skb was added to the buffer longer than this time ago, the earlier
711  * frames that have not yet been received are assumed to be lost and the skb
712  * can be released for processing. This may also release other skb's from the
713  * reorder buffer if there are no additional gaps between the frames.
714  *
715  * Callers must hold tid_agg_rx->reorder_lock.
716  */
717 #define HT_RX_REORDER_BUF_TIMEOUT (HZ / 10)
718 
719 static void ieee80211_sta_reorder_release(struct ieee80211_sub_if_data *sdata,
720 					  struct tid_ampdu_rx *tid_agg_rx)
721 {
722 	int index, j;
723 
724 	lockdep_assert_held(&tid_agg_rx->reorder_lock);
725 
726 	/* release the buffer until next missing frame */
727 	index = seq_sub(tid_agg_rx->head_seq_num, tid_agg_rx->ssn) %
728 						tid_agg_rx->buf_size;
729 	if (!tid_agg_rx->reorder_buf[index] &&
730 	    tid_agg_rx->stored_mpdu_num) {
731 		/*
732 		 * No buffers ready to be released, but check whether any
733 		 * frames in the reorder buffer have timed out.
734 		 */
735 		int skipped = 1;
736 		for (j = (index + 1) % tid_agg_rx->buf_size; j != index;
737 		     j = (j + 1) % tid_agg_rx->buf_size) {
738 			if (!tid_agg_rx->reorder_buf[j]) {
739 				skipped++;
740 				continue;
741 			}
742 			if (skipped &&
743 			    !time_after(jiffies, tid_agg_rx->reorder_time[j] +
744 					HT_RX_REORDER_BUF_TIMEOUT))
745 				goto set_release_timer;
746 
747 			ht_dbg_ratelimited(sdata,
748 					   "release an RX reorder frame due to timeout on earlier frames\n");
749 			ieee80211_release_reorder_frame(sdata, tid_agg_rx, j);
750 
751 			/*
752 			 * Increment the head seq# also for the skipped slots.
753 			 */
754 			tid_agg_rx->head_seq_num =
755 				(tid_agg_rx->head_seq_num + skipped) & SEQ_MASK;
756 			skipped = 0;
757 		}
758 	} else while (tid_agg_rx->reorder_buf[index]) {
759 		ieee80211_release_reorder_frame(sdata, tid_agg_rx, index);
760 		index =	seq_sub(tid_agg_rx->head_seq_num, tid_agg_rx->ssn) %
761 							tid_agg_rx->buf_size;
762 	}
763 
764 	if (tid_agg_rx->stored_mpdu_num) {
765 		j = index = seq_sub(tid_agg_rx->head_seq_num,
766 				    tid_agg_rx->ssn) % tid_agg_rx->buf_size;
767 
768 		for (; j != (index - 1) % tid_agg_rx->buf_size;
769 		     j = (j + 1) % tid_agg_rx->buf_size) {
770 			if (tid_agg_rx->reorder_buf[j])
771 				break;
772 		}
773 
774  set_release_timer:
775 
776 		mod_timer(&tid_agg_rx->reorder_timer,
777 			  tid_agg_rx->reorder_time[j] + 1 +
778 			  HT_RX_REORDER_BUF_TIMEOUT);
779 	} else {
780 		del_timer(&tid_agg_rx->reorder_timer);
781 	}
782 }
783 
784 /*
785  * As this function belongs to the RX path it must be under
786  * rcu_read_lock protection. It returns false if the frame
787  * can be processed immediately, true if it was consumed.
788  */
789 static bool ieee80211_sta_manage_reorder_buf(struct ieee80211_sub_if_data *sdata,
790 					     struct tid_ampdu_rx *tid_agg_rx,
791 					     struct sk_buff *skb)
792 {
793 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
794 	u16 sc = le16_to_cpu(hdr->seq_ctrl);
795 	u16 mpdu_seq_num = (sc & IEEE80211_SCTL_SEQ) >> 4;
796 	u16 head_seq_num, buf_size;
797 	int index;
798 	bool ret = true;
799 
800 	spin_lock(&tid_agg_rx->reorder_lock);
801 
802 	buf_size = tid_agg_rx->buf_size;
803 	head_seq_num = tid_agg_rx->head_seq_num;
804 
805 	/* frame with out of date sequence number */
806 	if (seq_less(mpdu_seq_num, head_seq_num)) {
807 		dev_kfree_skb(skb);
808 		goto out;
809 	}
810 
811 	/*
812 	 * If frame the sequence number exceeds our buffering window
813 	 * size release some previous frames to make room for this one.
814 	 */
815 	if (!seq_less(mpdu_seq_num, head_seq_num + buf_size)) {
816 		head_seq_num = seq_inc(seq_sub(mpdu_seq_num, buf_size));
817 		/* release stored frames up to new head to stack */
818 		ieee80211_release_reorder_frames(sdata, tid_agg_rx,
819 						 head_seq_num);
820 	}
821 
822 	/* Now the new frame is always in the range of the reordering buffer */
823 
824 	index = seq_sub(mpdu_seq_num, tid_agg_rx->ssn) % tid_agg_rx->buf_size;
825 
826 	/* check if we already stored this frame */
827 	if (tid_agg_rx->reorder_buf[index]) {
828 		dev_kfree_skb(skb);
829 		goto out;
830 	}
831 
832 	/*
833 	 * If the current MPDU is in the right order and nothing else
834 	 * is stored we can process it directly, no need to buffer it.
835 	 * If it is first but there's something stored, we may be able
836 	 * to release frames after this one.
837 	 */
838 	if (mpdu_seq_num == tid_agg_rx->head_seq_num &&
839 	    tid_agg_rx->stored_mpdu_num == 0) {
840 		tid_agg_rx->head_seq_num = seq_inc(tid_agg_rx->head_seq_num);
841 		ret = false;
842 		goto out;
843 	}
844 
845 	/* put the frame in the reordering buffer */
846 	tid_agg_rx->reorder_buf[index] = skb;
847 	tid_agg_rx->reorder_time[index] = jiffies;
848 	tid_agg_rx->stored_mpdu_num++;
849 	ieee80211_sta_reorder_release(sdata, tid_agg_rx);
850 
851  out:
852 	spin_unlock(&tid_agg_rx->reorder_lock);
853 	return ret;
854 }
855 
856 /*
857  * Reorder MPDUs from A-MPDUs, keeping them on a buffer. Returns
858  * true if the MPDU was buffered, false if it should be processed.
859  */
860 static void ieee80211_rx_reorder_ampdu(struct ieee80211_rx_data *rx)
861 {
862 	struct sk_buff *skb = rx->skb;
863 	struct ieee80211_local *local = rx->local;
864 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
865 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
866 	struct sta_info *sta = rx->sta;
867 	struct tid_ampdu_rx *tid_agg_rx;
868 	u16 sc;
869 	u8 tid, ack_policy;
870 
871 	if (!ieee80211_is_data_qos(hdr->frame_control))
872 		goto dont_reorder;
873 
874 	/*
875 	 * filter the QoS data rx stream according to
876 	 * STA/TID and check if this STA/TID is on aggregation
877 	 */
878 
879 	if (!sta)
880 		goto dont_reorder;
881 
882 	ack_policy = *ieee80211_get_qos_ctl(hdr) &
883 		     IEEE80211_QOS_CTL_ACK_POLICY_MASK;
884 	tid = *ieee80211_get_qos_ctl(hdr) & IEEE80211_QOS_CTL_TID_MASK;
885 
886 	tid_agg_rx = rcu_dereference(sta->ampdu_mlme.tid_rx[tid]);
887 	if (!tid_agg_rx)
888 		goto dont_reorder;
889 
890 	/* qos null data frames are excluded */
891 	if (unlikely(hdr->frame_control & cpu_to_le16(IEEE80211_STYPE_NULLFUNC)))
892 		goto dont_reorder;
893 
894 	/* not part of a BA session */
895 	if (ack_policy != IEEE80211_QOS_CTL_ACK_POLICY_BLOCKACK &&
896 	    ack_policy != IEEE80211_QOS_CTL_ACK_POLICY_NORMAL)
897 		goto dont_reorder;
898 
899 	/* not actually part of this BA session */
900 	if (!(status->rx_flags & IEEE80211_RX_RA_MATCH))
901 		goto dont_reorder;
902 
903 	/* new, potentially un-ordered, ampdu frame - process it */
904 
905 	/* reset session timer */
906 	if (tid_agg_rx->timeout)
907 		tid_agg_rx->last_rx = jiffies;
908 
909 	/* if this mpdu is fragmented - terminate rx aggregation session */
910 	sc = le16_to_cpu(hdr->seq_ctrl);
911 	if (sc & IEEE80211_SCTL_FRAG) {
912 		skb->pkt_type = IEEE80211_SDATA_QUEUE_TYPE_FRAME;
913 		skb_queue_tail(&rx->sdata->skb_queue, skb);
914 		ieee80211_queue_work(&local->hw, &rx->sdata->work);
915 		return;
916 	}
917 
918 	/*
919 	 * No locking needed -- we will only ever process one
920 	 * RX packet at a time, and thus own tid_agg_rx. All
921 	 * other code manipulating it needs to (and does) make
922 	 * sure that we cannot get to it any more before doing
923 	 * anything with it.
924 	 */
925 	if (ieee80211_sta_manage_reorder_buf(rx->sdata, tid_agg_rx, skb))
926 		return;
927 
928  dont_reorder:
929 	skb_queue_tail(&local->rx_skb_queue, skb);
930 }
931 
932 static ieee80211_rx_result debug_noinline
933 ieee80211_rx_h_check(struct ieee80211_rx_data *rx)
934 {
935 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
936 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
937 
938 	/* Drop duplicate 802.11 retransmissions (IEEE 802.11 Chap. 9.2.9) */
939 	if (rx->sta && !is_multicast_ether_addr(hdr->addr1)) {
940 		if (unlikely(ieee80211_has_retry(hdr->frame_control) &&
941 			     rx->sta->last_seq_ctrl[rx->seqno_idx] ==
942 			     hdr->seq_ctrl)) {
943 			if (status->rx_flags & IEEE80211_RX_RA_MATCH) {
944 				rx->local->dot11FrameDuplicateCount++;
945 				rx->sta->num_duplicates++;
946 			}
947 			return RX_DROP_UNUSABLE;
948 		} else
949 			rx->sta->last_seq_ctrl[rx->seqno_idx] = hdr->seq_ctrl;
950 	}
951 
952 	if (unlikely(rx->skb->len < 16)) {
953 		I802_DEBUG_INC(rx->local->rx_handlers_drop_short);
954 		return RX_DROP_MONITOR;
955 	}
956 
957 	/* Drop disallowed frame classes based on STA auth/assoc state;
958 	 * IEEE 802.11, Chap 5.5.
959 	 *
960 	 * mac80211 filters only based on association state, i.e. it drops
961 	 * Class 3 frames from not associated stations. hostapd sends
962 	 * deauth/disassoc frames when needed. In addition, hostapd is
963 	 * responsible for filtering on both auth and assoc states.
964 	 */
965 
966 	if (ieee80211_vif_is_mesh(&rx->sdata->vif))
967 		return ieee80211_rx_mesh_check(rx);
968 
969 	if (unlikely((ieee80211_is_data(hdr->frame_control) ||
970 		      ieee80211_is_pspoll(hdr->frame_control)) &&
971 		     rx->sdata->vif.type != NL80211_IFTYPE_ADHOC &&
972 		     rx->sdata->vif.type != NL80211_IFTYPE_WDS &&
973 		     (!rx->sta || !test_sta_flag(rx->sta, WLAN_STA_ASSOC)))) {
974 		/*
975 		 * accept port control frames from the AP even when it's not
976 		 * yet marked ASSOC to prevent a race where we don't set the
977 		 * assoc bit quickly enough before it sends the first frame
978 		 */
979 		if (rx->sta && rx->sdata->vif.type == NL80211_IFTYPE_STATION &&
980 		    ieee80211_is_data_present(hdr->frame_control)) {
981 			unsigned int hdrlen;
982 			__be16 ethertype;
983 
984 			hdrlen = ieee80211_hdrlen(hdr->frame_control);
985 
986 			if (rx->skb->len < hdrlen + 8)
987 				return RX_DROP_MONITOR;
988 
989 			skb_copy_bits(rx->skb, hdrlen + 6, &ethertype, 2);
990 			if (ethertype == rx->sdata->control_port_protocol)
991 				return RX_CONTINUE;
992 		}
993 
994 		if (rx->sdata->vif.type == NL80211_IFTYPE_AP &&
995 		    cfg80211_rx_spurious_frame(rx->sdata->dev,
996 					       hdr->addr2,
997 					       GFP_ATOMIC))
998 			return RX_DROP_UNUSABLE;
999 
1000 		return RX_DROP_MONITOR;
1001 	}
1002 
1003 	return RX_CONTINUE;
1004 }
1005 
1006 
1007 static ieee80211_rx_result debug_noinline
1008 ieee80211_rx_h_decrypt(struct ieee80211_rx_data *rx)
1009 {
1010 	struct sk_buff *skb = rx->skb;
1011 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
1012 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
1013 	int keyidx;
1014 	int hdrlen;
1015 	ieee80211_rx_result result = RX_DROP_UNUSABLE;
1016 	struct ieee80211_key *sta_ptk = NULL;
1017 	int mmie_keyidx = -1;
1018 	__le16 fc;
1019 
1020 	/*
1021 	 * Key selection 101
1022 	 *
1023 	 * There are four types of keys:
1024 	 *  - GTK (group keys)
1025 	 *  - IGTK (group keys for management frames)
1026 	 *  - PTK (pairwise keys)
1027 	 *  - STK (station-to-station pairwise keys)
1028 	 *
1029 	 * When selecting a key, we have to distinguish between multicast
1030 	 * (including broadcast) and unicast frames, the latter can only
1031 	 * use PTKs and STKs while the former always use GTKs and IGTKs.
1032 	 * Unless, of course, actual WEP keys ("pre-RSNA") are used, then
1033 	 * unicast frames can also use key indices like GTKs. Hence, if we
1034 	 * don't have a PTK/STK we check the key index for a WEP key.
1035 	 *
1036 	 * Note that in a regular BSS, multicast frames are sent by the
1037 	 * AP only, associated stations unicast the frame to the AP first
1038 	 * which then multicasts it on their behalf.
1039 	 *
1040 	 * There is also a slight problem in IBSS mode: GTKs are negotiated
1041 	 * with each station, that is something we don't currently handle.
1042 	 * The spec seems to expect that one negotiates the same key with
1043 	 * every station but there's no such requirement; VLANs could be
1044 	 * possible.
1045 	 */
1046 
1047 	/*
1048 	 * No point in finding a key and decrypting if the frame is neither
1049 	 * addressed to us nor a multicast frame.
1050 	 */
1051 	if (!(status->rx_flags & IEEE80211_RX_RA_MATCH))
1052 		return RX_CONTINUE;
1053 
1054 	/* start without a key */
1055 	rx->key = NULL;
1056 
1057 	if (rx->sta)
1058 		sta_ptk = rcu_dereference(rx->sta->ptk);
1059 
1060 	fc = hdr->frame_control;
1061 
1062 	if (!ieee80211_has_protected(fc))
1063 		mmie_keyidx = ieee80211_get_mmie_keyidx(rx->skb);
1064 
1065 	if (!is_multicast_ether_addr(hdr->addr1) && sta_ptk) {
1066 		rx->key = sta_ptk;
1067 		if ((status->flag & RX_FLAG_DECRYPTED) &&
1068 		    (status->flag & RX_FLAG_IV_STRIPPED))
1069 			return RX_CONTINUE;
1070 		/* Skip decryption if the frame is not protected. */
1071 		if (!ieee80211_has_protected(fc))
1072 			return RX_CONTINUE;
1073 	} else if (mmie_keyidx >= 0) {
1074 		/* Broadcast/multicast robust management frame / BIP */
1075 		if ((status->flag & RX_FLAG_DECRYPTED) &&
1076 		    (status->flag & RX_FLAG_IV_STRIPPED))
1077 			return RX_CONTINUE;
1078 
1079 		if (mmie_keyidx < NUM_DEFAULT_KEYS ||
1080 		    mmie_keyidx >= NUM_DEFAULT_KEYS + NUM_DEFAULT_MGMT_KEYS)
1081 			return RX_DROP_MONITOR; /* unexpected BIP keyidx */
1082 		if (rx->sta)
1083 			rx->key = rcu_dereference(rx->sta->gtk[mmie_keyidx]);
1084 		if (!rx->key)
1085 			rx->key = rcu_dereference(rx->sdata->keys[mmie_keyidx]);
1086 	} else if (!ieee80211_has_protected(fc)) {
1087 		/*
1088 		 * The frame was not protected, so skip decryption. However, we
1089 		 * need to set rx->key if there is a key that could have been
1090 		 * used so that the frame may be dropped if encryption would
1091 		 * have been expected.
1092 		 */
1093 		struct ieee80211_key *key = NULL;
1094 		struct ieee80211_sub_if_data *sdata = rx->sdata;
1095 		int i;
1096 
1097 		if (ieee80211_is_mgmt(fc) &&
1098 		    is_multicast_ether_addr(hdr->addr1) &&
1099 		    (key = rcu_dereference(rx->sdata->default_mgmt_key)))
1100 			rx->key = key;
1101 		else {
1102 			if (rx->sta) {
1103 				for (i = 0; i < NUM_DEFAULT_KEYS; i++) {
1104 					key = rcu_dereference(rx->sta->gtk[i]);
1105 					if (key)
1106 						break;
1107 				}
1108 			}
1109 			if (!key) {
1110 				for (i = 0; i < NUM_DEFAULT_KEYS; i++) {
1111 					key = rcu_dereference(sdata->keys[i]);
1112 					if (key)
1113 						break;
1114 				}
1115 			}
1116 			if (key)
1117 				rx->key = key;
1118 		}
1119 		return RX_CONTINUE;
1120 	} else {
1121 		u8 keyid;
1122 		/*
1123 		 * The device doesn't give us the IV so we won't be
1124 		 * able to look up the key. That's ok though, we
1125 		 * don't need to decrypt the frame, we just won't
1126 		 * be able to keep statistics accurate.
1127 		 * Except for key threshold notifications, should
1128 		 * we somehow allow the driver to tell us which key
1129 		 * the hardware used if this flag is set?
1130 		 */
1131 		if ((status->flag & RX_FLAG_DECRYPTED) &&
1132 		    (status->flag & RX_FLAG_IV_STRIPPED))
1133 			return RX_CONTINUE;
1134 
1135 		hdrlen = ieee80211_hdrlen(fc);
1136 
1137 		if (rx->skb->len < 8 + hdrlen)
1138 			return RX_DROP_UNUSABLE; /* TODO: count this? */
1139 
1140 		/*
1141 		 * no need to call ieee80211_wep_get_keyidx,
1142 		 * it verifies a bunch of things we've done already
1143 		 */
1144 		skb_copy_bits(rx->skb, hdrlen + 3, &keyid, 1);
1145 		keyidx = keyid >> 6;
1146 
1147 		/* check per-station GTK first, if multicast packet */
1148 		if (is_multicast_ether_addr(hdr->addr1) && rx->sta)
1149 			rx->key = rcu_dereference(rx->sta->gtk[keyidx]);
1150 
1151 		/* if not found, try default key */
1152 		if (!rx->key) {
1153 			rx->key = rcu_dereference(rx->sdata->keys[keyidx]);
1154 
1155 			/*
1156 			 * RSNA-protected unicast frames should always be
1157 			 * sent with pairwise or station-to-station keys,
1158 			 * but for WEP we allow using a key index as well.
1159 			 */
1160 			if (rx->key &&
1161 			    rx->key->conf.cipher != WLAN_CIPHER_SUITE_WEP40 &&
1162 			    rx->key->conf.cipher != WLAN_CIPHER_SUITE_WEP104 &&
1163 			    !is_multicast_ether_addr(hdr->addr1))
1164 				rx->key = NULL;
1165 		}
1166 	}
1167 
1168 	if (rx->key) {
1169 		if (unlikely(rx->key->flags & KEY_FLAG_TAINTED))
1170 			return RX_DROP_MONITOR;
1171 
1172 		rx->key->tx_rx_count++;
1173 		/* TODO: add threshold stuff again */
1174 	} else {
1175 		return RX_DROP_MONITOR;
1176 	}
1177 
1178 	switch (rx->key->conf.cipher) {
1179 	case WLAN_CIPHER_SUITE_WEP40:
1180 	case WLAN_CIPHER_SUITE_WEP104:
1181 		result = ieee80211_crypto_wep_decrypt(rx);
1182 		break;
1183 	case WLAN_CIPHER_SUITE_TKIP:
1184 		result = ieee80211_crypto_tkip_decrypt(rx);
1185 		break;
1186 	case WLAN_CIPHER_SUITE_CCMP:
1187 		result = ieee80211_crypto_ccmp_decrypt(rx);
1188 		break;
1189 	case WLAN_CIPHER_SUITE_AES_CMAC:
1190 		result = ieee80211_crypto_aes_cmac_decrypt(rx);
1191 		break;
1192 	default:
1193 		/*
1194 		 * We can reach here only with HW-only algorithms
1195 		 * but why didn't it decrypt the frame?!
1196 		 */
1197 		return RX_DROP_UNUSABLE;
1198 	}
1199 
1200 	/* the hdr variable is invalid after the decrypt handlers */
1201 
1202 	/* either the frame has been decrypted or will be dropped */
1203 	status->flag |= RX_FLAG_DECRYPTED;
1204 
1205 	return result;
1206 }
1207 
1208 static ieee80211_rx_result debug_noinline
1209 ieee80211_rx_h_check_more_data(struct ieee80211_rx_data *rx)
1210 {
1211 	struct ieee80211_local *local;
1212 	struct ieee80211_hdr *hdr;
1213 	struct sk_buff *skb;
1214 
1215 	local = rx->local;
1216 	skb = rx->skb;
1217 	hdr = (struct ieee80211_hdr *) skb->data;
1218 
1219 	if (!local->pspolling)
1220 		return RX_CONTINUE;
1221 
1222 	if (!ieee80211_has_fromds(hdr->frame_control))
1223 		/* this is not from AP */
1224 		return RX_CONTINUE;
1225 
1226 	if (!ieee80211_is_data(hdr->frame_control))
1227 		return RX_CONTINUE;
1228 
1229 	if (!ieee80211_has_moredata(hdr->frame_control)) {
1230 		/* AP has no more frames buffered for us */
1231 		local->pspolling = false;
1232 		return RX_CONTINUE;
1233 	}
1234 
1235 	/* more data bit is set, let's request a new frame from the AP */
1236 	ieee80211_send_pspoll(local, rx->sdata);
1237 
1238 	return RX_CONTINUE;
1239 }
1240 
1241 static void sta_ps_start(struct sta_info *sta)
1242 {
1243 	struct ieee80211_sub_if_data *sdata = sta->sdata;
1244 	struct ieee80211_local *local = sdata->local;
1245 	struct ps_data *ps;
1246 
1247 	if (sta->sdata->vif.type == NL80211_IFTYPE_AP ||
1248 	    sta->sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
1249 		ps = &sdata->bss->ps;
1250 	else
1251 		return;
1252 
1253 	atomic_inc(&ps->num_sta_ps);
1254 	set_sta_flag(sta, WLAN_STA_PS_STA);
1255 	if (!(local->hw.flags & IEEE80211_HW_AP_LINK_PS))
1256 		drv_sta_notify(local, sdata, STA_NOTIFY_SLEEP, &sta->sta);
1257 	ps_dbg(sdata, "STA %pM aid %d enters power save mode\n",
1258 	       sta->sta.addr, sta->sta.aid);
1259 }
1260 
1261 static void sta_ps_end(struct sta_info *sta)
1262 {
1263 	ps_dbg(sta->sdata, "STA %pM aid %d exits power save mode\n",
1264 	       sta->sta.addr, sta->sta.aid);
1265 
1266 	if (test_sta_flag(sta, WLAN_STA_PS_DRIVER)) {
1267 		ps_dbg(sta->sdata, "STA %pM aid %d driver-ps-blocked\n",
1268 		       sta->sta.addr, sta->sta.aid);
1269 		return;
1270 	}
1271 
1272 	ieee80211_sta_ps_deliver_wakeup(sta);
1273 }
1274 
1275 int ieee80211_sta_ps_transition(struct ieee80211_sta *sta, bool start)
1276 {
1277 	struct sta_info *sta_inf = container_of(sta, struct sta_info, sta);
1278 	bool in_ps;
1279 
1280 	WARN_ON(!(sta_inf->local->hw.flags & IEEE80211_HW_AP_LINK_PS));
1281 
1282 	/* Don't let the same PS state be set twice */
1283 	in_ps = test_sta_flag(sta_inf, WLAN_STA_PS_STA);
1284 	if ((start && in_ps) || (!start && !in_ps))
1285 		return -EINVAL;
1286 
1287 	if (start)
1288 		sta_ps_start(sta_inf);
1289 	else
1290 		sta_ps_end(sta_inf);
1291 
1292 	return 0;
1293 }
1294 EXPORT_SYMBOL(ieee80211_sta_ps_transition);
1295 
1296 static ieee80211_rx_result debug_noinline
1297 ieee80211_rx_h_uapsd_and_pspoll(struct ieee80211_rx_data *rx)
1298 {
1299 	struct ieee80211_sub_if_data *sdata = rx->sdata;
1300 	struct ieee80211_hdr *hdr = (void *)rx->skb->data;
1301 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
1302 	int tid, ac;
1303 
1304 	if (!rx->sta || !(status->rx_flags & IEEE80211_RX_RA_MATCH))
1305 		return RX_CONTINUE;
1306 
1307 	if (sdata->vif.type != NL80211_IFTYPE_AP &&
1308 	    sdata->vif.type != NL80211_IFTYPE_AP_VLAN)
1309 		return RX_CONTINUE;
1310 
1311 	/*
1312 	 * The device handles station powersave, so don't do anything about
1313 	 * uAPSD and PS-Poll frames (the latter shouldn't even come up from
1314 	 * it to mac80211 since they're handled.)
1315 	 */
1316 	if (sdata->local->hw.flags & IEEE80211_HW_AP_LINK_PS)
1317 		return RX_CONTINUE;
1318 
1319 	/*
1320 	 * Don't do anything if the station isn't already asleep. In
1321 	 * the uAPSD case, the station will probably be marked asleep,
1322 	 * in the PS-Poll case the station must be confused ...
1323 	 */
1324 	if (!test_sta_flag(rx->sta, WLAN_STA_PS_STA))
1325 		return RX_CONTINUE;
1326 
1327 	if (unlikely(ieee80211_is_pspoll(hdr->frame_control))) {
1328 		if (!test_sta_flag(rx->sta, WLAN_STA_SP)) {
1329 			if (!test_sta_flag(rx->sta, WLAN_STA_PS_DRIVER))
1330 				ieee80211_sta_ps_deliver_poll_response(rx->sta);
1331 			else
1332 				set_sta_flag(rx->sta, WLAN_STA_PSPOLL);
1333 		}
1334 
1335 		/* Free PS Poll skb here instead of returning RX_DROP that would
1336 		 * count as an dropped frame. */
1337 		dev_kfree_skb(rx->skb);
1338 
1339 		return RX_QUEUED;
1340 	} else if (!ieee80211_has_morefrags(hdr->frame_control) &&
1341 		   !(status->rx_flags & IEEE80211_RX_DEFERRED_RELEASE) &&
1342 		   ieee80211_has_pm(hdr->frame_control) &&
1343 		   (ieee80211_is_data_qos(hdr->frame_control) ||
1344 		    ieee80211_is_qos_nullfunc(hdr->frame_control))) {
1345 		tid = *ieee80211_get_qos_ctl(hdr) & IEEE80211_QOS_CTL_TID_MASK;
1346 		ac = ieee802_1d_to_ac[tid & 7];
1347 
1348 		/*
1349 		 * If this AC is not trigger-enabled do nothing.
1350 		 *
1351 		 * NB: This could/should check a separate bitmap of trigger-
1352 		 * enabled queues, but for now we only implement uAPSD w/o
1353 		 * TSPEC changes to the ACs, so they're always the same.
1354 		 */
1355 		if (!(rx->sta->sta.uapsd_queues & BIT(ac)))
1356 			return RX_CONTINUE;
1357 
1358 		/* if we are in a service period, do nothing */
1359 		if (test_sta_flag(rx->sta, WLAN_STA_SP))
1360 			return RX_CONTINUE;
1361 
1362 		if (!test_sta_flag(rx->sta, WLAN_STA_PS_DRIVER))
1363 			ieee80211_sta_ps_deliver_uapsd(rx->sta);
1364 		else
1365 			set_sta_flag(rx->sta, WLAN_STA_UAPSD);
1366 	}
1367 
1368 	return RX_CONTINUE;
1369 }
1370 
1371 static ieee80211_rx_result debug_noinline
1372 ieee80211_rx_h_sta_process(struct ieee80211_rx_data *rx)
1373 {
1374 	struct sta_info *sta = rx->sta;
1375 	struct sk_buff *skb = rx->skb;
1376 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
1377 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
1378 
1379 	if (!sta)
1380 		return RX_CONTINUE;
1381 
1382 	/*
1383 	 * Update last_rx only for IBSS packets which are for the current
1384 	 * BSSID and for station already AUTHORIZED to avoid keeping the
1385 	 * current IBSS network alive in cases where other STAs start
1386 	 * using different BSSID. This will also give the station another
1387 	 * chance to restart the authentication/authorization in case
1388 	 * something went wrong the first time.
1389 	 */
1390 	if (rx->sdata->vif.type == NL80211_IFTYPE_ADHOC) {
1391 		u8 *bssid = ieee80211_get_bssid(hdr, rx->skb->len,
1392 						NL80211_IFTYPE_ADHOC);
1393 		if (ether_addr_equal(bssid, rx->sdata->u.ibss.bssid) &&
1394 		    test_sta_flag(sta, WLAN_STA_AUTHORIZED)) {
1395 			sta->last_rx = jiffies;
1396 			if (ieee80211_is_data(hdr->frame_control)) {
1397 				sta->last_rx_rate_idx = status->rate_idx;
1398 				sta->last_rx_rate_flag = status->flag;
1399 				sta->last_rx_rate_vht_nss = status->vht_nss;
1400 			}
1401 		}
1402 	} else if (!is_multicast_ether_addr(hdr->addr1)) {
1403 		/*
1404 		 * Mesh beacons will update last_rx when if they are found to
1405 		 * match the current local configuration when processed.
1406 		 */
1407 		sta->last_rx = jiffies;
1408 		if (ieee80211_is_data(hdr->frame_control)) {
1409 			sta->last_rx_rate_idx = status->rate_idx;
1410 			sta->last_rx_rate_flag = status->flag;
1411 			sta->last_rx_rate_vht_nss = status->vht_nss;
1412 		}
1413 	}
1414 
1415 	if (!(status->rx_flags & IEEE80211_RX_RA_MATCH))
1416 		return RX_CONTINUE;
1417 
1418 	if (rx->sdata->vif.type == NL80211_IFTYPE_STATION)
1419 		ieee80211_sta_rx_notify(rx->sdata, hdr);
1420 
1421 	sta->rx_fragments++;
1422 	sta->rx_bytes += rx->skb->len;
1423 	if (!(status->flag & RX_FLAG_NO_SIGNAL_VAL)) {
1424 		sta->last_signal = status->signal;
1425 		ewma_add(&sta->avg_signal, -status->signal);
1426 	}
1427 
1428 	/*
1429 	 * Change STA power saving mode only at the end of a frame
1430 	 * exchange sequence.
1431 	 */
1432 	if (!(sta->local->hw.flags & IEEE80211_HW_AP_LINK_PS) &&
1433 	    !ieee80211_has_morefrags(hdr->frame_control) &&
1434 	    !(status->rx_flags & IEEE80211_RX_DEFERRED_RELEASE) &&
1435 	    (rx->sdata->vif.type == NL80211_IFTYPE_AP ||
1436 	     rx->sdata->vif.type == NL80211_IFTYPE_AP_VLAN)) {
1437 		if (test_sta_flag(sta, WLAN_STA_PS_STA)) {
1438 			/*
1439 			 * Ignore doze->wake transitions that are
1440 			 * indicated by non-data frames, the standard
1441 			 * is unclear here, but for example going to
1442 			 * PS mode and then scanning would cause a
1443 			 * doze->wake transition for the probe request,
1444 			 * and that is clearly undesirable.
1445 			 */
1446 			if (ieee80211_is_data(hdr->frame_control) &&
1447 			    !ieee80211_has_pm(hdr->frame_control))
1448 				sta_ps_end(sta);
1449 		} else {
1450 			if (ieee80211_has_pm(hdr->frame_control))
1451 				sta_ps_start(sta);
1452 		}
1453 	}
1454 
1455 	/*
1456 	 * Drop (qos-)data::nullfunc frames silently, since they
1457 	 * are used only to control station power saving mode.
1458 	 */
1459 	if (ieee80211_is_nullfunc(hdr->frame_control) ||
1460 	    ieee80211_is_qos_nullfunc(hdr->frame_control)) {
1461 		I802_DEBUG_INC(rx->local->rx_handlers_drop_nullfunc);
1462 
1463 		/*
1464 		 * If we receive a 4-addr nullfunc frame from a STA
1465 		 * that was not moved to a 4-addr STA vlan yet send
1466 		 * the event to userspace and for older hostapd drop
1467 		 * the frame to the monitor interface.
1468 		 */
1469 		if (ieee80211_has_a4(hdr->frame_control) &&
1470 		    (rx->sdata->vif.type == NL80211_IFTYPE_AP ||
1471 		     (rx->sdata->vif.type == NL80211_IFTYPE_AP_VLAN &&
1472 		      !rx->sdata->u.vlan.sta))) {
1473 			if (!test_and_set_sta_flag(sta, WLAN_STA_4ADDR_EVENT))
1474 				cfg80211_rx_unexpected_4addr_frame(
1475 					rx->sdata->dev, sta->sta.addr,
1476 					GFP_ATOMIC);
1477 			return RX_DROP_MONITOR;
1478 		}
1479 		/*
1480 		 * Update counter and free packet here to avoid
1481 		 * counting this as a dropped packed.
1482 		 */
1483 		sta->rx_packets++;
1484 		dev_kfree_skb(rx->skb);
1485 		return RX_QUEUED;
1486 	}
1487 
1488 	return RX_CONTINUE;
1489 } /* ieee80211_rx_h_sta_process */
1490 
1491 static inline struct ieee80211_fragment_entry *
1492 ieee80211_reassemble_add(struct ieee80211_sub_if_data *sdata,
1493 			 unsigned int frag, unsigned int seq, int rx_queue,
1494 			 struct sk_buff **skb)
1495 {
1496 	struct ieee80211_fragment_entry *entry;
1497 
1498 	entry = &sdata->fragments[sdata->fragment_next++];
1499 	if (sdata->fragment_next >= IEEE80211_FRAGMENT_MAX)
1500 		sdata->fragment_next = 0;
1501 
1502 	if (!skb_queue_empty(&entry->skb_list))
1503 		__skb_queue_purge(&entry->skb_list);
1504 
1505 	__skb_queue_tail(&entry->skb_list, *skb); /* no need for locking */
1506 	*skb = NULL;
1507 	entry->first_frag_time = jiffies;
1508 	entry->seq = seq;
1509 	entry->rx_queue = rx_queue;
1510 	entry->last_frag = frag;
1511 	entry->ccmp = 0;
1512 	entry->extra_len = 0;
1513 
1514 	return entry;
1515 }
1516 
1517 static inline struct ieee80211_fragment_entry *
1518 ieee80211_reassemble_find(struct ieee80211_sub_if_data *sdata,
1519 			  unsigned int frag, unsigned int seq,
1520 			  int rx_queue, struct ieee80211_hdr *hdr)
1521 {
1522 	struct ieee80211_fragment_entry *entry;
1523 	int i, idx;
1524 
1525 	idx = sdata->fragment_next;
1526 	for (i = 0; i < IEEE80211_FRAGMENT_MAX; i++) {
1527 		struct ieee80211_hdr *f_hdr;
1528 
1529 		idx--;
1530 		if (idx < 0)
1531 			idx = IEEE80211_FRAGMENT_MAX - 1;
1532 
1533 		entry = &sdata->fragments[idx];
1534 		if (skb_queue_empty(&entry->skb_list) || entry->seq != seq ||
1535 		    entry->rx_queue != rx_queue ||
1536 		    entry->last_frag + 1 != frag)
1537 			continue;
1538 
1539 		f_hdr = (struct ieee80211_hdr *)entry->skb_list.next->data;
1540 
1541 		/*
1542 		 * Check ftype and addresses are equal, else check next fragment
1543 		 */
1544 		if (((hdr->frame_control ^ f_hdr->frame_control) &
1545 		     cpu_to_le16(IEEE80211_FCTL_FTYPE)) ||
1546 		    !ether_addr_equal(hdr->addr1, f_hdr->addr1) ||
1547 		    !ether_addr_equal(hdr->addr2, f_hdr->addr2))
1548 			continue;
1549 
1550 		if (time_after(jiffies, entry->first_frag_time + 2 * HZ)) {
1551 			__skb_queue_purge(&entry->skb_list);
1552 			continue;
1553 		}
1554 		return entry;
1555 	}
1556 
1557 	return NULL;
1558 }
1559 
1560 static ieee80211_rx_result debug_noinline
1561 ieee80211_rx_h_defragment(struct ieee80211_rx_data *rx)
1562 {
1563 	struct ieee80211_hdr *hdr;
1564 	u16 sc;
1565 	__le16 fc;
1566 	unsigned int frag, seq;
1567 	struct ieee80211_fragment_entry *entry;
1568 	struct sk_buff *skb;
1569 	struct ieee80211_rx_status *status;
1570 
1571 	hdr = (struct ieee80211_hdr *)rx->skb->data;
1572 	fc = hdr->frame_control;
1573 
1574 	if (ieee80211_is_ctl(fc))
1575 		return RX_CONTINUE;
1576 
1577 	sc = le16_to_cpu(hdr->seq_ctrl);
1578 	frag = sc & IEEE80211_SCTL_FRAG;
1579 
1580 	if (likely((!ieee80211_has_morefrags(fc) && frag == 0) ||
1581 		   is_multicast_ether_addr(hdr->addr1))) {
1582 		/* not fragmented */
1583 		goto out;
1584 	}
1585 	I802_DEBUG_INC(rx->local->rx_handlers_fragments);
1586 
1587 	if (skb_linearize(rx->skb))
1588 		return RX_DROP_UNUSABLE;
1589 
1590 	/*
1591 	 *  skb_linearize() might change the skb->data and
1592 	 *  previously cached variables (in this case, hdr) need to
1593 	 *  be refreshed with the new data.
1594 	 */
1595 	hdr = (struct ieee80211_hdr *)rx->skb->data;
1596 	seq = (sc & IEEE80211_SCTL_SEQ) >> 4;
1597 
1598 	if (frag == 0) {
1599 		/* This is the first fragment of a new frame. */
1600 		entry = ieee80211_reassemble_add(rx->sdata, frag, seq,
1601 						 rx->seqno_idx, &(rx->skb));
1602 		if (rx->key && rx->key->conf.cipher == WLAN_CIPHER_SUITE_CCMP &&
1603 		    ieee80211_has_protected(fc)) {
1604 			int queue = rx->security_idx;
1605 			/* Store CCMP PN so that we can verify that the next
1606 			 * fragment has a sequential PN value. */
1607 			entry->ccmp = 1;
1608 			memcpy(entry->last_pn,
1609 			       rx->key->u.ccmp.rx_pn[queue],
1610 			       CCMP_PN_LEN);
1611 		}
1612 		return RX_QUEUED;
1613 	}
1614 
1615 	/* This is a fragment for a frame that should already be pending in
1616 	 * fragment cache. Add this fragment to the end of the pending entry.
1617 	 */
1618 	entry = ieee80211_reassemble_find(rx->sdata, frag, seq,
1619 					  rx->seqno_idx, hdr);
1620 	if (!entry) {
1621 		I802_DEBUG_INC(rx->local->rx_handlers_drop_defrag);
1622 		return RX_DROP_MONITOR;
1623 	}
1624 
1625 	/* Verify that MPDUs within one MSDU have sequential PN values.
1626 	 * (IEEE 802.11i, 8.3.3.4.5) */
1627 	if (entry->ccmp) {
1628 		int i;
1629 		u8 pn[CCMP_PN_LEN], *rpn;
1630 		int queue;
1631 		if (!rx->key || rx->key->conf.cipher != WLAN_CIPHER_SUITE_CCMP)
1632 			return RX_DROP_UNUSABLE;
1633 		memcpy(pn, entry->last_pn, CCMP_PN_LEN);
1634 		for (i = CCMP_PN_LEN - 1; i >= 0; i--) {
1635 			pn[i]++;
1636 			if (pn[i])
1637 				break;
1638 		}
1639 		queue = rx->security_idx;
1640 		rpn = rx->key->u.ccmp.rx_pn[queue];
1641 		if (memcmp(pn, rpn, CCMP_PN_LEN))
1642 			return RX_DROP_UNUSABLE;
1643 		memcpy(entry->last_pn, pn, CCMP_PN_LEN);
1644 	}
1645 
1646 	skb_pull(rx->skb, ieee80211_hdrlen(fc));
1647 	__skb_queue_tail(&entry->skb_list, rx->skb);
1648 	entry->last_frag = frag;
1649 	entry->extra_len += rx->skb->len;
1650 	if (ieee80211_has_morefrags(fc)) {
1651 		rx->skb = NULL;
1652 		return RX_QUEUED;
1653 	}
1654 
1655 	rx->skb = __skb_dequeue(&entry->skb_list);
1656 	if (skb_tailroom(rx->skb) < entry->extra_len) {
1657 		I802_DEBUG_INC(rx->local->rx_expand_skb_head2);
1658 		if (unlikely(pskb_expand_head(rx->skb, 0, entry->extra_len,
1659 					      GFP_ATOMIC))) {
1660 			I802_DEBUG_INC(rx->local->rx_handlers_drop_defrag);
1661 			__skb_queue_purge(&entry->skb_list);
1662 			return RX_DROP_UNUSABLE;
1663 		}
1664 	}
1665 	while ((skb = __skb_dequeue(&entry->skb_list))) {
1666 		memcpy(skb_put(rx->skb, skb->len), skb->data, skb->len);
1667 		dev_kfree_skb(skb);
1668 	}
1669 
1670 	/* Complete frame has been reassembled - process it now */
1671 	status = IEEE80211_SKB_RXCB(rx->skb);
1672 	status->rx_flags |= IEEE80211_RX_FRAGMENTED;
1673 
1674  out:
1675 	if (rx->sta)
1676 		rx->sta->rx_packets++;
1677 	if (is_multicast_ether_addr(hdr->addr1))
1678 		rx->local->dot11MulticastReceivedFrameCount++;
1679 	else
1680 		ieee80211_led_rx(rx->local);
1681 	return RX_CONTINUE;
1682 }
1683 
1684 static int ieee80211_802_1x_port_control(struct ieee80211_rx_data *rx)
1685 {
1686 	if (unlikely(!rx->sta || !test_sta_flag(rx->sta, WLAN_STA_AUTHORIZED)))
1687 		return -EACCES;
1688 
1689 	return 0;
1690 }
1691 
1692 static int ieee80211_drop_unencrypted(struct ieee80211_rx_data *rx, __le16 fc)
1693 {
1694 	struct sk_buff *skb = rx->skb;
1695 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
1696 
1697 	/*
1698 	 * Pass through unencrypted frames if the hardware has
1699 	 * decrypted them already.
1700 	 */
1701 	if (status->flag & RX_FLAG_DECRYPTED)
1702 		return 0;
1703 
1704 	/* Drop unencrypted frames if key is set. */
1705 	if (unlikely(!ieee80211_has_protected(fc) &&
1706 		     !ieee80211_is_nullfunc(fc) &&
1707 		     ieee80211_is_data(fc) &&
1708 		     (rx->key || rx->sdata->drop_unencrypted)))
1709 		return -EACCES;
1710 
1711 	return 0;
1712 }
1713 
1714 static int ieee80211_drop_unencrypted_mgmt(struct ieee80211_rx_data *rx)
1715 {
1716 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
1717 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
1718 	__le16 fc = hdr->frame_control;
1719 
1720 	/*
1721 	 * Pass through unencrypted frames if the hardware has
1722 	 * decrypted them already.
1723 	 */
1724 	if (status->flag & RX_FLAG_DECRYPTED)
1725 		return 0;
1726 
1727 	if (rx->sta && test_sta_flag(rx->sta, WLAN_STA_MFP)) {
1728 		if (unlikely(!ieee80211_has_protected(fc) &&
1729 			     ieee80211_is_unicast_robust_mgmt_frame(rx->skb) &&
1730 			     rx->key)) {
1731 			if (ieee80211_is_deauth(fc))
1732 				cfg80211_send_unprot_deauth(rx->sdata->dev,
1733 							    rx->skb->data,
1734 							    rx->skb->len);
1735 			else if (ieee80211_is_disassoc(fc))
1736 				cfg80211_send_unprot_disassoc(rx->sdata->dev,
1737 							      rx->skb->data,
1738 							      rx->skb->len);
1739 			return -EACCES;
1740 		}
1741 		/* BIP does not use Protected field, so need to check MMIE */
1742 		if (unlikely(ieee80211_is_multicast_robust_mgmt_frame(rx->skb) &&
1743 			     ieee80211_get_mmie_keyidx(rx->skb) < 0)) {
1744 			if (ieee80211_is_deauth(fc))
1745 				cfg80211_send_unprot_deauth(rx->sdata->dev,
1746 							    rx->skb->data,
1747 							    rx->skb->len);
1748 			else if (ieee80211_is_disassoc(fc))
1749 				cfg80211_send_unprot_disassoc(rx->sdata->dev,
1750 							      rx->skb->data,
1751 							      rx->skb->len);
1752 			return -EACCES;
1753 		}
1754 		/*
1755 		 * When using MFP, Action frames are not allowed prior to
1756 		 * having configured keys.
1757 		 */
1758 		if (unlikely(ieee80211_is_action(fc) && !rx->key &&
1759 			     ieee80211_is_robust_mgmt_frame(
1760 				     (struct ieee80211_hdr *) rx->skb->data)))
1761 			return -EACCES;
1762 	}
1763 
1764 	return 0;
1765 }
1766 
1767 static int
1768 __ieee80211_data_to_8023(struct ieee80211_rx_data *rx, bool *port_control)
1769 {
1770 	struct ieee80211_sub_if_data *sdata = rx->sdata;
1771 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
1772 	bool check_port_control = false;
1773 	struct ethhdr *ehdr;
1774 	int ret;
1775 
1776 	*port_control = false;
1777 	if (ieee80211_has_a4(hdr->frame_control) &&
1778 	    sdata->vif.type == NL80211_IFTYPE_AP_VLAN && !sdata->u.vlan.sta)
1779 		return -1;
1780 
1781 	if (sdata->vif.type == NL80211_IFTYPE_STATION &&
1782 	    !!sdata->u.mgd.use_4addr != !!ieee80211_has_a4(hdr->frame_control)) {
1783 
1784 		if (!sdata->u.mgd.use_4addr)
1785 			return -1;
1786 		else
1787 			check_port_control = true;
1788 	}
1789 
1790 	if (is_multicast_ether_addr(hdr->addr1) &&
1791 	    sdata->vif.type == NL80211_IFTYPE_AP_VLAN && sdata->u.vlan.sta)
1792 		return -1;
1793 
1794 	ret = ieee80211_data_to_8023(rx->skb, sdata->vif.addr, sdata->vif.type);
1795 	if (ret < 0)
1796 		return ret;
1797 
1798 	ehdr = (struct ethhdr *) rx->skb->data;
1799 	if (ehdr->h_proto == rx->sdata->control_port_protocol)
1800 		*port_control = true;
1801 	else if (check_port_control)
1802 		return -1;
1803 
1804 	return 0;
1805 }
1806 
1807 /*
1808  * requires that rx->skb is a frame with ethernet header
1809  */
1810 static bool ieee80211_frame_allowed(struct ieee80211_rx_data *rx, __le16 fc)
1811 {
1812 	static const u8 pae_group_addr[ETH_ALEN] __aligned(2)
1813 		= { 0x01, 0x80, 0xC2, 0x00, 0x00, 0x03 };
1814 	struct ethhdr *ehdr = (struct ethhdr *) rx->skb->data;
1815 
1816 	/*
1817 	 * Allow EAPOL frames to us/the PAE group address regardless
1818 	 * of whether the frame was encrypted or not.
1819 	 */
1820 	if (ehdr->h_proto == rx->sdata->control_port_protocol &&
1821 	    (ether_addr_equal(ehdr->h_dest, rx->sdata->vif.addr) ||
1822 	     ether_addr_equal(ehdr->h_dest, pae_group_addr)))
1823 		return true;
1824 
1825 	if (ieee80211_802_1x_port_control(rx) ||
1826 	    ieee80211_drop_unencrypted(rx, fc))
1827 		return false;
1828 
1829 	return true;
1830 }
1831 
1832 /*
1833  * requires that rx->skb is a frame with ethernet header
1834  */
1835 static void
1836 ieee80211_deliver_skb(struct ieee80211_rx_data *rx)
1837 {
1838 	struct ieee80211_sub_if_data *sdata = rx->sdata;
1839 	struct net_device *dev = sdata->dev;
1840 	struct sk_buff *skb, *xmit_skb;
1841 	struct ethhdr *ehdr = (struct ethhdr *) rx->skb->data;
1842 	struct sta_info *dsta;
1843 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
1844 
1845 	skb = rx->skb;
1846 	xmit_skb = NULL;
1847 
1848 	if ((sdata->vif.type == NL80211_IFTYPE_AP ||
1849 	     sdata->vif.type == NL80211_IFTYPE_AP_VLAN) &&
1850 	    !(sdata->flags & IEEE80211_SDATA_DONT_BRIDGE_PACKETS) &&
1851 	    (status->rx_flags & IEEE80211_RX_RA_MATCH) &&
1852 	    (sdata->vif.type != NL80211_IFTYPE_AP_VLAN || !sdata->u.vlan.sta)) {
1853 		if (is_multicast_ether_addr(ehdr->h_dest)) {
1854 			/*
1855 			 * send multicast frames both to higher layers in
1856 			 * local net stack and back to the wireless medium
1857 			 */
1858 			xmit_skb = skb_copy(skb, GFP_ATOMIC);
1859 			if (!xmit_skb)
1860 				net_info_ratelimited("%s: failed to clone multicast frame\n",
1861 						    dev->name);
1862 		} else {
1863 			dsta = sta_info_get(sdata, skb->data);
1864 			if (dsta) {
1865 				/*
1866 				 * The destination station is associated to
1867 				 * this AP (in this VLAN), so send the frame
1868 				 * directly to it and do not pass it to local
1869 				 * net stack.
1870 				 */
1871 				xmit_skb = skb;
1872 				skb = NULL;
1873 			}
1874 		}
1875 	}
1876 
1877 	if (skb) {
1878 		int align __maybe_unused;
1879 
1880 #ifndef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
1881 		/*
1882 		 * 'align' will only take the values 0 or 2 here
1883 		 * since all frames are required to be aligned
1884 		 * to 2-byte boundaries when being passed to
1885 		 * mac80211. That also explains the __skb_push()
1886 		 * below.
1887 		 */
1888 		align = ((unsigned long)(skb->data + sizeof(struct ethhdr))) & 3;
1889 		if (align) {
1890 			if (WARN_ON(skb_headroom(skb) < 3)) {
1891 				dev_kfree_skb(skb);
1892 				skb = NULL;
1893 			} else {
1894 				u8 *data = skb->data;
1895 				size_t len = skb_headlen(skb);
1896 				skb->data -= align;
1897 				memmove(skb->data, data, len);
1898 				skb_set_tail_pointer(skb, len);
1899 			}
1900 		}
1901 #endif
1902 
1903 		if (skb) {
1904 			/* deliver to local stack */
1905 			skb->protocol = eth_type_trans(skb, dev);
1906 			memset(skb->cb, 0, sizeof(skb->cb));
1907 			netif_receive_skb(skb);
1908 		}
1909 	}
1910 
1911 	if (xmit_skb) {
1912 		/*
1913 		 * Send to wireless media and increase priority by 256 to
1914 		 * keep the received priority instead of reclassifying
1915 		 * the frame (see cfg80211_classify8021d).
1916 		 */
1917 		xmit_skb->priority += 256;
1918 		xmit_skb->protocol = htons(ETH_P_802_3);
1919 		skb_reset_network_header(xmit_skb);
1920 		skb_reset_mac_header(xmit_skb);
1921 		dev_queue_xmit(xmit_skb);
1922 	}
1923 }
1924 
1925 static ieee80211_rx_result debug_noinline
1926 ieee80211_rx_h_amsdu(struct ieee80211_rx_data *rx)
1927 {
1928 	struct net_device *dev = rx->sdata->dev;
1929 	struct sk_buff *skb = rx->skb;
1930 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
1931 	__le16 fc = hdr->frame_control;
1932 	struct sk_buff_head frame_list;
1933 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
1934 
1935 	if (unlikely(!ieee80211_is_data(fc)))
1936 		return RX_CONTINUE;
1937 
1938 	if (unlikely(!ieee80211_is_data_present(fc)))
1939 		return RX_DROP_MONITOR;
1940 
1941 	if (!(status->rx_flags & IEEE80211_RX_AMSDU))
1942 		return RX_CONTINUE;
1943 
1944 	if (ieee80211_has_a4(hdr->frame_control) &&
1945 	    rx->sdata->vif.type == NL80211_IFTYPE_AP_VLAN &&
1946 	    !rx->sdata->u.vlan.sta)
1947 		return RX_DROP_UNUSABLE;
1948 
1949 	if (is_multicast_ether_addr(hdr->addr1) &&
1950 	    ((rx->sdata->vif.type == NL80211_IFTYPE_AP_VLAN &&
1951 	      rx->sdata->u.vlan.sta) ||
1952 	     (rx->sdata->vif.type == NL80211_IFTYPE_STATION &&
1953 	      rx->sdata->u.mgd.use_4addr)))
1954 		return RX_DROP_UNUSABLE;
1955 
1956 	skb->dev = dev;
1957 	__skb_queue_head_init(&frame_list);
1958 
1959 	if (skb_linearize(skb))
1960 		return RX_DROP_UNUSABLE;
1961 
1962 	ieee80211_amsdu_to_8023s(skb, &frame_list, dev->dev_addr,
1963 				 rx->sdata->vif.type,
1964 				 rx->local->hw.extra_tx_headroom, true);
1965 
1966 	while (!skb_queue_empty(&frame_list)) {
1967 		rx->skb = __skb_dequeue(&frame_list);
1968 
1969 		if (!ieee80211_frame_allowed(rx, fc)) {
1970 			dev_kfree_skb(rx->skb);
1971 			continue;
1972 		}
1973 		dev->stats.rx_packets++;
1974 		dev->stats.rx_bytes += rx->skb->len;
1975 
1976 		ieee80211_deliver_skb(rx);
1977 	}
1978 
1979 	return RX_QUEUED;
1980 }
1981 
1982 #ifdef CONFIG_MAC80211_MESH
1983 static ieee80211_rx_result
1984 ieee80211_rx_h_mesh_fwding(struct ieee80211_rx_data *rx)
1985 {
1986 	struct ieee80211_hdr *fwd_hdr, *hdr;
1987 	struct ieee80211_tx_info *info;
1988 	struct ieee80211s_hdr *mesh_hdr;
1989 	struct sk_buff *skb = rx->skb, *fwd_skb;
1990 	struct ieee80211_local *local = rx->local;
1991 	struct ieee80211_sub_if_data *sdata = rx->sdata;
1992 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
1993 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
1994 	__le16 reason = cpu_to_le16(WLAN_REASON_MESH_PATH_NOFORWARD);
1995 	u16 q, hdrlen;
1996 
1997 	hdr = (struct ieee80211_hdr *) skb->data;
1998 	hdrlen = ieee80211_hdrlen(hdr->frame_control);
1999 
2000 	/* make sure fixed part of mesh header is there, also checks skb len */
2001 	if (!pskb_may_pull(rx->skb, hdrlen + 6))
2002 		return RX_DROP_MONITOR;
2003 
2004 	mesh_hdr = (struct ieee80211s_hdr *) (skb->data + hdrlen);
2005 
2006 	/* make sure full mesh header is there, also checks skb len */
2007 	if (!pskb_may_pull(rx->skb,
2008 			   hdrlen + ieee80211_get_mesh_hdrlen(mesh_hdr)))
2009 		return RX_DROP_MONITOR;
2010 
2011 	/* reload pointers */
2012 	hdr = (struct ieee80211_hdr *) skb->data;
2013 	mesh_hdr = (struct ieee80211s_hdr *) (skb->data + hdrlen);
2014 
2015 	/* frame is in RMC, don't forward */
2016 	if (ieee80211_is_data(hdr->frame_control) &&
2017 	    is_multicast_ether_addr(hdr->addr1) &&
2018 	    mesh_rmc_check(hdr->addr3, mesh_hdr, rx->sdata))
2019 		return RX_DROP_MONITOR;
2020 
2021 	if (!ieee80211_is_data(hdr->frame_control) ||
2022 	    !(status->rx_flags & IEEE80211_RX_RA_MATCH))
2023 		return RX_CONTINUE;
2024 
2025 	if (!mesh_hdr->ttl)
2026 		return RX_DROP_MONITOR;
2027 
2028 	if (mesh_hdr->flags & MESH_FLAGS_AE) {
2029 		struct mesh_path *mppath;
2030 		char *proxied_addr;
2031 		char *mpp_addr;
2032 
2033 		if (is_multicast_ether_addr(hdr->addr1)) {
2034 			mpp_addr = hdr->addr3;
2035 			proxied_addr = mesh_hdr->eaddr1;
2036 		} else if (mesh_hdr->flags & MESH_FLAGS_AE_A5_A6) {
2037 			/* has_a4 already checked in ieee80211_rx_mesh_check */
2038 			mpp_addr = hdr->addr4;
2039 			proxied_addr = mesh_hdr->eaddr2;
2040 		} else {
2041 			return RX_DROP_MONITOR;
2042 		}
2043 
2044 		rcu_read_lock();
2045 		mppath = mpp_path_lookup(proxied_addr, sdata);
2046 		if (!mppath) {
2047 			mpp_path_add(proxied_addr, mpp_addr, sdata);
2048 		} else {
2049 			spin_lock_bh(&mppath->state_lock);
2050 			if (!ether_addr_equal(mppath->mpp, mpp_addr))
2051 				memcpy(mppath->mpp, mpp_addr, ETH_ALEN);
2052 			spin_unlock_bh(&mppath->state_lock);
2053 		}
2054 		rcu_read_unlock();
2055 	}
2056 
2057 	/* Frame has reached destination.  Don't forward */
2058 	if (!is_multicast_ether_addr(hdr->addr1) &&
2059 	    ether_addr_equal(sdata->vif.addr, hdr->addr3))
2060 		return RX_CONTINUE;
2061 
2062 	q = ieee80211_select_queue_80211(sdata, skb, hdr);
2063 	if (ieee80211_queue_stopped(&local->hw, q)) {
2064 		IEEE80211_IFSTA_MESH_CTR_INC(ifmsh, dropped_frames_congestion);
2065 		return RX_DROP_MONITOR;
2066 	}
2067 	skb_set_queue_mapping(skb, q);
2068 
2069 	if (!--mesh_hdr->ttl) {
2070 		IEEE80211_IFSTA_MESH_CTR_INC(ifmsh, dropped_frames_ttl);
2071 		goto out;
2072 	}
2073 
2074 	if (!ifmsh->mshcfg.dot11MeshForwarding)
2075 		goto out;
2076 
2077 	fwd_skb = skb_copy(skb, GFP_ATOMIC);
2078 	if (!fwd_skb) {
2079 		net_info_ratelimited("%s: failed to clone mesh frame\n",
2080 				    sdata->name);
2081 		goto out;
2082 	}
2083 
2084 	fwd_hdr =  (struct ieee80211_hdr *) fwd_skb->data;
2085 	info = IEEE80211_SKB_CB(fwd_skb);
2086 	memset(info, 0, sizeof(*info));
2087 	info->flags |= IEEE80211_TX_INTFL_NEED_TXPROCESSING;
2088 	info->control.vif = &rx->sdata->vif;
2089 	info->control.jiffies = jiffies;
2090 	if (is_multicast_ether_addr(fwd_hdr->addr1)) {
2091 		IEEE80211_IFSTA_MESH_CTR_INC(ifmsh, fwded_mcast);
2092 		memcpy(fwd_hdr->addr2, sdata->vif.addr, ETH_ALEN);
2093 	} else if (!mesh_nexthop_lookup(fwd_skb, sdata)) {
2094 		IEEE80211_IFSTA_MESH_CTR_INC(ifmsh, fwded_unicast);
2095 	} else {
2096 		/* unable to resolve next hop */
2097 		mesh_path_error_tx(ifmsh->mshcfg.element_ttl, fwd_hdr->addr3,
2098 				   0, reason, fwd_hdr->addr2, sdata);
2099 		IEEE80211_IFSTA_MESH_CTR_INC(ifmsh, dropped_frames_no_route);
2100 		kfree_skb(fwd_skb);
2101 		return RX_DROP_MONITOR;
2102 	}
2103 
2104 	IEEE80211_IFSTA_MESH_CTR_INC(ifmsh, fwded_frames);
2105 	ieee80211_add_pending_skb(local, fwd_skb);
2106  out:
2107 	if (is_multicast_ether_addr(hdr->addr1) ||
2108 	    sdata->dev->flags & IFF_PROMISC)
2109 		return RX_CONTINUE;
2110 	else
2111 		return RX_DROP_MONITOR;
2112 }
2113 #endif
2114 
2115 static ieee80211_rx_result debug_noinline
2116 ieee80211_rx_h_data(struct ieee80211_rx_data *rx)
2117 {
2118 	struct ieee80211_sub_if_data *sdata = rx->sdata;
2119 	struct ieee80211_local *local = rx->local;
2120 	struct net_device *dev = sdata->dev;
2121 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
2122 	__le16 fc = hdr->frame_control;
2123 	bool port_control;
2124 	int err;
2125 
2126 	if (unlikely(!ieee80211_is_data(hdr->frame_control)))
2127 		return RX_CONTINUE;
2128 
2129 	if (unlikely(!ieee80211_is_data_present(hdr->frame_control)))
2130 		return RX_DROP_MONITOR;
2131 
2132 	/*
2133 	 * Send unexpected-4addr-frame event to hostapd. For older versions,
2134 	 * also drop the frame to cooked monitor interfaces.
2135 	 */
2136 	if (ieee80211_has_a4(hdr->frame_control) &&
2137 	    sdata->vif.type == NL80211_IFTYPE_AP) {
2138 		if (rx->sta &&
2139 		    !test_and_set_sta_flag(rx->sta, WLAN_STA_4ADDR_EVENT))
2140 			cfg80211_rx_unexpected_4addr_frame(
2141 				rx->sdata->dev, rx->sta->sta.addr, GFP_ATOMIC);
2142 		return RX_DROP_MONITOR;
2143 	}
2144 
2145 	err = __ieee80211_data_to_8023(rx, &port_control);
2146 	if (unlikely(err))
2147 		return RX_DROP_UNUSABLE;
2148 
2149 	if (!ieee80211_frame_allowed(rx, fc))
2150 		return RX_DROP_MONITOR;
2151 
2152 	if (rx->sdata->vif.type == NL80211_IFTYPE_AP_VLAN &&
2153 	    unlikely(port_control) && sdata->bss) {
2154 		sdata = container_of(sdata->bss, struct ieee80211_sub_if_data,
2155 				     u.ap);
2156 		dev = sdata->dev;
2157 		rx->sdata = sdata;
2158 	}
2159 
2160 	rx->skb->dev = dev;
2161 
2162 	dev->stats.rx_packets++;
2163 	dev->stats.rx_bytes += rx->skb->len;
2164 
2165 	if (local->ps_sdata && local->hw.conf.dynamic_ps_timeout > 0 &&
2166 	    !is_multicast_ether_addr(
2167 		    ((struct ethhdr *)rx->skb->data)->h_dest) &&
2168 	    (!local->scanning &&
2169 	     !test_bit(SDATA_STATE_OFFCHANNEL, &sdata->state))) {
2170 			mod_timer(&local->dynamic_ps_timer, jiffies +
2171 			 msecs_to_jiffies(local->hw.conf.dynamic_ps_timeout));
2172 	}
2173 
2174 	ieee80211_deliver_skb(rx);
2175 
2176 	return RX_QUEUED;
2177 }
2178 
2179 static ieee80211_rx_result debug_noinline
2180 ieee80211_rx_h_ctrl(struct ieee80211_rx_data *rx)
2181 {
2182 	struct sk_buff *skb = rx->skb;
2183 	struct ieee80211_bar *bar = (struct ieee80211_bar *)skb->data;
2184 	struct tid_ampdu_rx *tid_agg_rx;
2185 	u16 start_seq_num;
2186 	u16 tid;
2187 
2188 	if (likely(!ieee80211_is_ctl(bar->frame_control)))
2189 		return RX_CONTINUE;
2190 
2191 	if (ieee80211_is_back_req(bar->frame_control)) {
2192 		struct {
2193 			__le16 control, start_seq_num;
2194 		} __packed bar_data;
2195 
2196 		if (!rx->sta)
2197 			return RX_DROP_MONITOR;
2198 
2199 		if (skb_copy_bits(skb, offsetof(struct ieee80211_bar, control),
2200 				  &bar_data, sizeof(bar_data)))
2201 			return RX_DROP_MONITOR;
2202 
2203 		tid = le16_to_cpu(bar_data.control) >> 12;
2204 
2205 		tid_agg_rx = rcu_dereference(rx->sta->ampdu_mlme.tid_rx[tid]);
2206 		if (!tid_agg_rx)
2207 			return RX_DROP_MONITOR;
2208 
2209 		start_seq_num = le16_to_cpu(bar_data.start_seq_num) >> 4;
2210 
2211 		/* reset session timer */
2212 		if (tid_agg_rx->timeout)
2213 			mod_timer(&tid_agg_rx->session_timer,
2214 				  TU_TO_EXP_TIME(tid_agg_rx->timeout));
2215 
2216 		spin_lock(&tid_agg_rx->reorder_lock);
2217 		/* release stored frames up to start of BAR */
2218 		ieee80211_release_reorder_frames(rx->sdata, tid_agg_rx,
2219 						 start_seq_num);
2220 		spin_unlock(&tid_agg_rx->reorder_lock);
2221 
2222 		kfree_skb(skb);
2223 		return RX_QUEUED;
2224 	}
2225 
2226 	/*
2227 	 * After this point, we only want management frames,
2228 	 * so we can drop all remaining control frames to
2229 	 * cooked monitor interfaces.
2230 	 */
2231 	return RX_DROP_MONITOR;
2232 }
2233 
2234 static void ieee80211_process_sa_query_req(struct ieee80211_sub_if_data *sdata,
2235 					   struct ieee80211_mgmt *mgmt,
2236 					   size_t len)
2237 {
2238 	struct ieee80211_local *local = sdata->local;
2239 	struct sk_buff *skb;
2240 	struct ieee80211_mgmt *resp;
2241 
2242 	if (!ether_addr_equal(mgmt->da, sdata->vif.addr)) {
2243 		/* Not to own unicast address */
2244 		return;
2245 	}
2246 
2247 	if (!ether_addr_equal(mgmt->sa, sdata->u.mgd.bssid) ||
2248 	    !ether_addr_equal(mgmt->bssid, sdata->u.mgd.bssid)) {
2249 		/* Not from the current AP or not associated yet. */
2250 		return;
2251 	}
2252 
2253 	if (len < 24 + 1 + sizeof(resp->u.action.u.sa_query)) {
2254 		/* Too short SA Query request frame */
2255 		return;
2256 	}
2257 
2258 	skb = dev_alloc_skb(sizeof(*resp) + local->hw.extra_tx_headroom);
2259 	if (skb == NULL)
2260 		return;
2261 
2262 	skb_reserve(skb, local->hw.extra_tx_headroom);
2263 	resp = (struct ieee80211_mgmt *) skb_put(skb, 24);
2264 	memset(resp, 0, 24);
2265 	memcpy(resp->da, mgmt->sa, ETH_ALEN);
2266 	memcpy(resp->sa, sdata->vif.addr, ETH_ALEN);
2267 	memcpy(resp->bssid, sdata->u.mgd.bssid, ETH_ALEN);
2268 	resp->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
2269 					  IEEE80211_STYPE_ACTION);
2270 	skb_put(skb, 1 + sizeof(resp->u.action.u.sa_query));
2271 	resp->u.action.category = WLAN_CATEGORY_SA_QUERY;
2272 	resp->u.action.u.sa_query.action = WLAN_ACTION_SA_QUERY_RESPONSE;
2273 	memcpy(resp->u.action.u.sa_query.trans_id,
2274 	       mgmt->u.action.u.sa_query.trans_id,
2275 	       WLAN_SA_QUERY_TR_ID_LEN);
2276 
2277 	ieee80211_tx_skb(sdata, skb);
2278 }
2279 
2280 static ieee80211_rx_result debug_noinline
2281 ieee80211_rx_h_mgmt_check(struct ieee80211_rx_data *rx)
2282 {
2283 	struct ieee80211_mgmt *mgmt = (struct ieee80211_mgmt *) rx->skb->data;
2284 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
2285 
2286 	/*
2287 	 * From here on, look only at management frames.
2288 	 * Data and control frames are already handled,
2289 	 * and unknown (reserved) frames are useless.
2290 	 */
2291 	if (rx->skb->len < 24)
2292 		return RX_DROP_MONITOR;
2293 
2294 	if (!ieee80211_is_mgmt(mgmt->frame_control))
2295 		return RX_DROP_MONITOR;
2296 
2297 	if (rx->sdata->vif.type == NL80211_IFTYPE_AP &&
2298 	    ieee80211_is_beacon(mgmt->frame_control) &&
2299 	    !(rx->flags & IEEE80211_RX_BEACON_REPORTED)) {
2300 		int sig = 0;
2301 
2302 		if (rx->local->hw.flags & IEEE80211_HW_SIGNAL_DBM)
2303 			sig = status->signal;
2304 
2305 		cfg80211_report_obss_beacon(rx->local->hw.wiphy,
2306 					    rx->skb->data, rx->skb->len,
2307 					    status->freq, sig);
2308 		rx->flags |= IEEE80211_RX_BEACON_REPORTED;
2309 	}
2310 
2311 	if (!(status->rx_flags & IEEE80211_RX_RA_MATCH))
2312 		return RX_DROP_MONITOR;
2313 
2314 	if (ieee80211_drop_unencrypted_mgmt(rx))
2315 		return RX_DROP_UNUSABLE;
2316 
2317 	return RX_CONTINUE;
2318 }
2319 
2320 static ieee80211_rx_result debug_noinline
2321 ieee80211_rx_h_action(struct ieee80211_rx_data *rx)
2322 {
2323 	struct ieee80211_local *local = rx->local;
2324 	struct ieee80211_sub_if_data *sdata = rx->sdata;
2325 	struct ieee80211_mgmt *mgmt = (struct ieee80211_mgmt *) rx->skb->data;
2326 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
2327 	int len = rx->skb->len;
2328 
2329 	if (!ieee80211_is_action(mgmt->frame_control))
2330 		return RX_CONTINUE;
2331 
2332 	/* drop too small frames */
2333 	if (len < IEEE80211_MIN_ACTION_SIZE)
2334 		return RX_DROP_UNUSABLE;
2335 
2336 	if (!rx->sta && mgmt->u.action.category != WLAN_CATEGORY_PUBLIC &&
2337 	    mgmt->u.action.category != WLAN_CATEGORY_SELF_PROTECTED)
2338 		return RX_DROP_UNUSABLE;
2339 
2340 	if (!(status->rx_flags & IEEE80211_RX_RA_MATCH))
2341 		return RX_DROP_UNUSABLE;
2342 
2343 	switch (mgmt->u.action.category) {
2344 	case WLAN_CATEGORY_HT:
2345 		/* reject HT action frames from stations not supporting HT */
2346 		if (!rx->sta->sta.ht_cap.ht_supported)
2347 			goto invalid;
2348 
2349 		if (sdata->vif.type != NL80211_IFTYPE_STATION &&
2350 		    sdata->vif.type != NL80211_IFTYPE_MESH_POINT &&
2351 		    sdata->vif.type != NL80211_IFTYPE_AP_VLAN &&
2352 		    sdata->vif.type != NL80211_IFTYPE_AP &&
2353 		    sdata->vif.type != NL80211_IFTYPE_ADHOC)
2354 			break;
2355 
2356 		/* verify action & smps_control are present */
2357 		if (len < IEEE80211_MIN_ACTION_SIZE + 2)
2358 			goto invalid;
2359 
2360 		switch (mgmt->u.action.u.ht_smps.action) {
2361 		case WLAN_HT_ACTION_SMPS: {
2362 			struct ieee80211_supported_band *sband;
2363 			u8 smps;
2364 
2365 			/* convert to HT capability */
2366 			switch (mgmt->u.action.u.ht_smps.smps_control) {
2367 			case WLAN_HT_SMPS_CONTROL_DISABLED:
2368 				smps = WLAN_HT_CAP_SM_PS_DISABLED;
2369 				break;
2370 			case WLAN_HT_SMPS_CONTROL_STATIC:
2371 				smps = WLAN_HT_CAP_SM_PS_STATIC;
2372 				break;
2373 			case WLAN_HT_SMPS_CONTROL_DYNAMIC:
2374 				smps = WLAN_HT_CAP_SM_PS_DYNAMIC;
2375 				break;
2376 			default:
2377 				goto invalid;
2378 			}
2379 			smps <<= IEEE80211_HT_CAP_SM_PS_SHIFT;
2380 
2381 			/* if no change do nothing */
2382 			if ((rx->sta->sta.ht_cap.cap &
2383 					IEEE80211_HT_CAP_SM_PS) == smps)
2384 				goto handled;
2385 
2386 			rx->sta->sta.ht_cap.cap &= ~IEEE80211_HT_CAP_SM_PS;
2387 			rx->sta->sta.ht_cap.cap |= smps;
2388 
2389 			sband = rx->local->hw.wiphy->bands[status->band];
2390 
2391 			rate_control_rate_update(local, sband, rx->sta,
2392 						 IEEE80211_RC_SMPS_CHANGED);
2393 			goto handled;
2394 		}
2395 		default:
2396 			goto invalid;
2397 		}
2398 
2399 		break;
2400 	case WLAN_CATEGORY_BACK:
2401 		if (sdata->vif.type != NL80211_IFTYPE_STATION &&
2402 		    sdata->vif.type != NL80211_IFTYPE_MESH_POINT &&
2403 		    sdata->vif.type != NL80211_IFTYPE_AP_VLAN &&
2404 		    sdata->vif.type != NL80211_IFTYPE_AP &&
2405 		    sdata->vif.type != NL80211_IFTYPE_ADHOC)
2406 			break;
2407 
2408 		/* verify action_code is present */
2409 		if (len < IEEE80211_MIN_ACTION_SIZE + 1)
2410 			break;
2411 
2412 		switch (mgmt->u.action.u.addba_req.action_code) {
2413 		case WLAN_ACTION_ADDBA_REQ:
2414 			if (len < (IEEE80211_MIN_ACTION_SIZE +
2415 				   sizeof(mgmt->u.action.u.addba_req)))
2416 				goto invalid;
2417 			break;
2418 		case WLAN_ACTION_ADDBA_RESP:
2419 			if (len < (IEEE80211_MIN_ACTION_SIZE +
2420 				   sizeof(mgmt->u.action.u.addba_resp)))
2421 				goto invalid;
2422 			break;
2423 		case WLAN_ACTION_DELBA:
2424 			if (len < (IEEE80211_MIN_ACTION_SIZE +
2425 				   sizeof(mgmt->u.action.u.delba)))
2426 				goto invalid;
2427 			break;
2428 		default:
2429 			goto invalid;
2430 		}
2431 
2432 		goto queue;
2433 	case WLAN_CATEGORY_SPECTRUM_MGMT:
2434 		if (status->band != IEEE80211_BAND_5GHZ)
2435 			break;
2436 
2437 		if (sdata->vif.type != NL80211_IFTYPE_STATION)
2438 			break;
2439 
2440 		/* verify action_code is present */
2441 		if (len < IEEE80211_MIN_ACTION_SIZE + 1)
2442 			break;
2443 
2444 		switch (mgmt->u.action.u.measurement.action_code) {
2445 		case WLAN_ACTION_SPCT_MSR_REQ:
2446 			if (len < (IEEE80211_MIN_ACTION_SIZE +
2447 				   sizeof(mgmt->u.action.u.measurement)))
2448 				break;
2449 			ieee80211_process_measurement_req(sdata, mgmt, len);
2450 			goto handled;
2451 		case WLAN_ACTION_SPCT_CHL_SWITCH:
2452 			if (len < (IEEE80211_MIN_ACTION_SIZE +
2453 				   sizeof(mgmt->u.action.u.chan_switch)))
2454 				break;
2455 
2456 			if (sdata->vif.type != NL80211_IFTYPE_STATION)
2457 				break;
2458 
2459 			if (!ether_addr_equal(mgmt->bssid, sdata->u.mgd.bssid))
2460 				break;
2461 
2462 			goto queue;
2463 		}
2464 		break;
2465 	case WLAN_CATEGORY_SA_QUERY:
2466 		if (len < (IEEE80211_MIN_ACTION_SIZE +
2467 			   sizeof(mgmt->u.action.u.sa_query)))
2468 			break;
2469 
2470 		switch (mgmt->u.action.u.sa_query.action) {
2471 		case WLAN_ACTION_SA_QUERY_REQUEST:
2472 			if (sdata->vif.type != NL80211_IFTYPE_STATION)
2473 				break;
2474 			ieee80211_process_sa_query_req(sdata, mgmt, len);
2475 			goto handled;
2476 		}
2477 		break;
2478 	case WLAN_CATEGORY_SELF_PROTECTED:
2479 		if (len < (IEEE80211_MIN_ACTION_SIZE +
2480 			   sizeof(mgmt->u.action.u.self_prot.action_code)))
2481 			break;
2482 
2483 		switch (mgmt->u.action.u.self_prot.action_code) {
2484 		case WLAN_SP_MESH_PEERING_OPEN:
2485 		case WLAN_SP_MESH_PEERING_CLOSE:
2486 		case WLAN_SP_MESH_PEERING_CONFIRM:
2487 			if (!ieee80211_vif_is_mesh(&sdata->vif))
2488 				goto invalid;
2489 			if (sdata->u.mesh.security != IEEE80211_MESH_SEC_NONE)
2490 				/* userspace handles this frame */
2491 				break;
2492 			goto queue;
2493 		case WLAN_SP_MGK_INFORM:
2494 		case WLAN_SP_MGK_ACK:
2495 			if (!ieee80211_vif_is_mesh(&sdata->vif))
2496 				goto invalid;
2497 			break;
2498 		}
2499 		break;
2500 	case WLAN_CATEGORY_MESH_ACTION:
2501 		if (len < (IEEE80211_MIN_ACTION_SIZE +
2502 			   sizeof(mgmt->u.action.u.mesh_action.action_code)))
2503 			break;
2504 
2505 		if (!ieee80211_vif_is_mesh(&sdata->vif))
2506 			break;
2507 		if (mesh_action_is_path_sel(mgmt) &&
2508 		    !mesh_path_sel_is_hwmp(sdata))
2509 			break;
2510 		goto queue;
2511 	}
2512 
2513 	return RX_CONTINUE;
2514 
2515  invalid:
2516 	status->rx_flags |= IEEE80211_RX_MALFORMED_ACTION_FRM;
2517 	/* will return in the next handlers */
2518 	return RX_CONTINUE;
2519 
2520  handled:
2521 	if (rx->sta)
2522 		rx->sta->rx_packets++;
2523 	dev_kfree_skb(rx->skb);
2524 	return RX_QUEUED;
2525 
2526  queue:
2527 	rx->skb->pkt_type = IEEE80211_SDATA_QUEUE_TYPE_FRAME;
2528 	skb_queue_tail(&sdata->skb_queue, rx->skb);
2529 	ieee80211_queue_work(&local->hw, &sdata->work);
2530 	if (rx->sta)
2531 		rx->sta->rx_packets++;
2532 	return RX_QUEUED;
2533 }
2534 
2535 static ieee80211_rx_result debug_noinline
2536 ieee80211_rx_h_userspace_mgmt(struct ieee80211_rx_data *rx)
2537 {
2538 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
2539 	int sig = 0;
2540 
2541 	/* skip known-bad action frames and return them in the next handler */
2542 	if (status->rx_flags & IEEE80211_RX_MALFORMED_ACTION_FRM)
2543 		return RX_CONTINUE;
2544 
2545 	/*
2546 	 * Getting here means the kernel doesn't know how to handle
2547 	 * it, but maybe userspace does ... include returned frames
2548 	 * so userspace can register for those to know whether ones
2549 	 * it transmitted were processed or returned.
2550 	 */
2551 
2552 	if (rx->local->hw.flags & IEEE80211_HW_SIGNAL_DBM)
2553 		sig = status->signal;
2554 
2555 	if (cfg80211_rx_mgmt(&rx->sdata->wdev, status->freq, sig,
2556 			     rx->skb->data, rx->skb->len,
2557 			     GFP_ATOMIC)) {
2558 		if (rx->sta)
2559 			rx->sta->rx_packets++;
2560 		dev_kfree_skb(rx->skb);
2561 		return RX_QUEUED;
2562 	}
2563 
2564 	return RX_CONTINUE;
2565 }
2566 
2567 static ieee80211_rx_result debug_noinline
2568 ieee80211_rx_h_action_return(struct ieee80211_rx_data *rx)
2569 {
2570 	struct ieee80211_local *local = rx->local;
2571 	struct ieee80211_mgmt *mgmt = (struct ieee80211_mgmt *) rx->skb->data;
2572 	struct sk_buff *nskb;
2573 	struct ieee80211_sub_if_data *sdata = rx->sdata;
2574 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
2575 
2576 	if (!ieee80211_is_action(mgmt->frame_control))
2577 		return RX_CONTINUE;
2578 
2579 	/*
2580 	 * For AP mode, hostapd is responsible for handling any action
2581 	 * frames that we didn't handle, including returning unknown
2582 	 * ones. For all other modes we will return them to the sender,
2583 	 * setting the 0x80 bit in the action category, as required by
2584 	 * 802.11-2012 9.24.4.
2585 	 * Newer versions of hostapd shall also use the management frame
2586 	 * registration mechanisms, but older ones still use cooked
2587 	 * monitor interfaces so push all frames there.
2588 	 */
2589 	if (!(status->rx_flags & IEEE80211_RX_MALFORMED_ACTION_FRM) &&
2590 	    (sdata->vif.type == NL80211_IFTYPE_AP ||
2591 	     sdata->vif.type == NL80211_IFTYPE_AP_VLAN))
2592 		return RX_DROP_MONITOR;
2593 
2594 	if (is_multicast_ether_addr(mgmt->da))
2595 		return RX_DROP_MONITOR;
2596 
2597 	/* do not return rejected action frames */
2598 	if (mgmt->u.action.category & 0x80)
2599 		return RX_DROP_UNUSABLE;
2600 
2601 	nskb = skb_copy_expand(rx->skb, local->hw.extra_tx_headroom, 0,
2602 			       GFP_ATOMIC);
2603 	if (nskb) {
2604 		struct ieee80211_mgmt *nmgmt = (void *)nskb->data;
2605 
2606 		nmgmt->u.action.category |= 0x80;
2607 		memcpy(nmgmt->da, nmgmt->sa, ETH_ALEN);
2608 		memcpy(nmgmt->sa, rx->sdata->vif.addr, ETH_ALEN);
2609 
2610 		memset(nskb->cb, 0, sizeof(nskb->cb));
2611 
2612 		ieee80211_tx_skb(rx->sdata, nskb);
2613 	}
2614 	dev_kfree_skb(rx->skb);
2615 	return RX_QUEUED;
2616 }
2617 
2618 static ieee80211_rx_result debug_noinline
2619 ieee80211_rx_h_mgmt(struct ieee80211_rx_data *rx)
2620 {
2621 	struct ieee80211_sub_if_data *sdata = rx->sdata;
2622 	struct ieee80211_mgmt *mgmt = (void *)rx->skb->data;
2623 	__le16 stype;
2624 
2625 	stype = mgmt->frame_control & cpu_to_le16(IEEE80211_FCTL_STYPE);
2626 
2627 	if (!ieee80211_vif_is_mesh(&sdata->vif) &&
2628 	    sdata->vif.type != NL80211_IFTYPE_ADHOC &&
2629 	    sdata->vif.type != NL80211_IFTYPE_STATION)
2630 		return RX_DROP_MONITOR;
2631 
2632 	switch (stype) {
2633 	case cpu_to_le16(IEEE80211_STYPE_AUTH):
2634 	case cpu_to_le16(IEEE80211_STYPE_BEACON):
2635 	case cpu_to_le16(IEEE80211_STYPE_PROBE_RESP):
2636 		/* process for all: mesh, mlme, ibss */
2637 		break;
2638 	case cpu_to_le16(IEEE80211_STYPE_ASSOC_RESP):
2639 	case cpu_to_le16(IEEE80211_STYPE_REASSOC_RESP):
2640 	case cpu_to_le16(IEEE80211_STYPE_DEAUTH):
2641 	case cpu_to_le16(IEEE80211_STYPE_DISASSOC):
2642 		if (is_multicast_ether_addr(mgmt->da) &&
2643 		    !is_broadcast_ether_addr(mgmt->da))
2644 			return RX_DROP_MONITOR;
2645 
2646 		/* process only for station */
2647 		if (sdata->vif.type != NL80211_IFTYPE_STATION)
2648 			return RX_DROP_MONITOR;
2649 		break;
2650 	case cpu_to_le16(IEEE80211_STYPE_PROBE_REQ):
2651 		/* process only for ibss */
2652 		if (sdata->vif.type != NL80211_IFTYPE_ADHOC)
2653 			return RX_DROP_MONITOR;
2654 		break;
2655 	default:
2656 		return RX_DROP_MONITOR;
2657 	}
2658 
2659 	/* queue up frame and kick off work to process it */
2660 	rx->skb->pkt_type = IEEE80211_SDATA_QUEUE_TYPE_FRAME;
2661 	skb_queue_tail(&sdata->skb_queue, rx->skb);
2662 	ieee80211_queue_work(&rx->local->hw, &sdata->work);
2663 	if (rx->sta)
2664 		rx->sta->rx_packets++;
2665 
2666 	return RX_QUEUED;
2667 }
2668 
2669 /* TODO: use IEEE80211_RX_FRAGMENTED */
2670 static void ieee80211_rx_cooked_monitor(struct ieee80211_rx_data *rx,
2671 					struct ieee80211_rate *rate)
2672 {
2673 	struct ieee80211_sub_if_data *sdata;
2674 	struct ieee80211_local *local = rx->local;
2675 	struct sk_buff *skb = rx->skb, *skb2;
2676 	struct net_device *prev_dev = NULL;
2677 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
2678 	int needed_headroom;
2679 
2680 	/*
2681 	 * If cooked monitor has been processed already, then
2682 	 * don't do it again. If not, set the flag.
2683 	 */
2684 	if (rx->flags & IEEE80211_RX_CMNTR)
2685 		goto out_free_skb;
2686 	rx->flags |= IEEE80211_RX_CMNTR;
2687 
2688 	/* If there are no cooked monitor interfaces, just free the SKB */
2689 	if (!local->cooked_mntrs)
2690 		goto out_free_skb;
2691 
2692 	/* room for the radiotap header based on driver features */
2693 	needed_headroom = ieee80211_rx_radiotap_space(local, status);
2694 
2695 	if (skb_headroom(skb) < needed_headroom &&
2696 	    pskb_expand_head(skb, needed_headroom, 0, GFP_ATOMIC))
2697 		goto out_free_skb;
2698 
2699 	/* prepend radiotap information */
2700 	ieee80211_add_rx_radiotap_header(local, skb, rate, needed_headroom,
2701 					 false);
2702 
2703 	skb_set_mac_header(skb, 0);
2704 	skb->ip_summed = CHECKSUM_UNNECESSARY;
2705 	skb->pkt_type = PACKET_OTHERHOST;
2706 	skb->protocol = htons(ETH_P_802_2);
2707 
2708 	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
2709 		if (!ieee80211_sdata_running(sdata))
2710 			continue;
2711 
2712 		if (sdata->vif.type != NL80211_IFTYPE_MONITOR ||
2713 		    !(sdata->u.mntr_flags & MONITOR_FLAG_COOK_FRAMES))
2714 			continue;
2715 
2716 		if (prev_dev) {
2717 			skb2 = skb_clone(skb, GFP_ATOMIC);
2718 			if (skb2) {
2719 				skb2->dev = prev_dev;
2720 				netif_receive_skb(skb2);
2721 			}
2722 		}
2723 
2724 		prev_dev = sdata->dev;
2725 		sdata->dev->stats.rx_packets++;
2726 		sdata->dev->stats.rx_bytes += skb->len;
2727 	}
2728 
2729 	if (prev_dev) {
2730 		skb->dev = prev_dev;
2731 		netif_receive_skb(skb);
2732 		return;
2733 	}
2734 
2735  out_free_skb:
2736 	dev_kfree_skb(skb);
2737 }
2738 
2739 static void ieee80211_rx_handlers_result(struct ieee80211_rx_data *rx,
2740 					 ieee80211_rx_result res)
2741 {
2742 	switch (res) {
2743 	case RX_DROP_MONITOR:
2744 		I802_DEBUG_INC(rx->sdata->local->rx_handlers_drop);
2745 		if (rx->sta)
2746 			rx->sta->rx_dropped++;
2747 		/* fall through */
2748 	case RX_CONTINUE: {
2749 		struct ieee80211_rate *rate = NULL;
2750 		struct ieee80211_supported_band *sband;
2751 		struct ieee80211_rx_status *status;
2752 
2753 		status = IEEE80211_SKB_RXCB((rx->skb));
2754 
2755 		sband = rx->local->hw.wiphy->bands[status->band];
2756 		if (!(status->flag & RX_FLAG_HT) &&
2757 		    !(status->flag & RX_FLAG_VHT))
2758 			rate = &sband->bitrates[status->rate_idx];
2759 
2760 		ieee80211_rx_cooked_monitor(rx, rate);
2761 		break;
2762 		}
2763 	case RX_DROP_UNUSABLE:
2764 		I802_DEBUG_INC(rx->sdata->local->rx_handlers_drop);
2765 		if (rx->sta)
2766 			rx->sta->rx_dropped++;
2767 		dev_kfree_skb(rx->skb);
2768 		break;
2769 	case RX_QUEUED:
2770 		I802_DEBUG_INC(rx->sdata->local->rx_handlers_queued);
2771 		break;
2772 	}
2773 }
2774 
2775 static void ieee80211_rx_handlers(struct ieee80211_rx_data *rx)
2776 {
2777 	ieee80211_rx_result res = RX_DROP_MONITOR;
2778 	struct sk_buff *skb;
2779 
2780 #define CALL_RXH(rxh)			\
2781 	do {				\
2782 		res = rxh(rx);		\
2783 		if (res != RX_CONTINUE)	\
2784 			goto rxh_next;  \
2785 	} while (0);
2786 
2787 	spin_lock(&rx->local->rx_skb_queue.lock);
2788 	if (rx->local->running_rx_handler)
2789 		goto unlock;
2790 
2791 	rx->local->running_rx_handler = true;
2792 
2793 	while ((skb = __skb_dequeue(&rx->local->rx_skb_queue))) {
2794 		spin_unlock(&rx->local->rx_skb_queue.lock);
2795 
2796 		/*
2797 		 * all the other fields are valid across frames
2798 		 * that belong to an aMPDU since they are on the
2799 		 * same TID from the same station
2800 		 */
2801 		rx->skb = skb;
2802 
2803 		CALL_RXH(ieee80211_rx_h_decrypt)
2804 		CALL_RXH(ieee80211_rx_h_check_more_data)
2805 		CALL_RXH(ieee80211_rx_h_uapsd_and_pspoll)
2806 		CALL_RXH(ieee80211_rx_h_sta_process)
2807 		CALL_RXH(ieee80211_rx_h_defragment)
2808 		CALL_RXH(ieee80211_rx_h_michael_mic_verify)
2809 		/* must be after MMIC verify so header is counted in MPDU mic */
2810 #ifdef CONFIG_MAC80211_MESH
2811 		if (ieee80211_vif_is_mesh(&rx->sdata->vif))
2812 			CALL_RXH(ieee80211_rx_h_mesh_fwding);
2813 #endif
2814 		CALL_RXH(ieee80211_rx_h_amsdu)
2815 		CALL_RXH(ieee80211_rx_h_data)
2816 		CALL_RXH(ieee80211_rx_h_ctrl);
2817 		CALL_RXH(ieee80211_rx_h_mgmt_check)
2818 		CALL_RXH(ieee80211_rx_h_action)
2819 		CALL_RXH(ieee80211_rx_h_userspace_mgmt)
2820 		CALL_RXH(ieee80211_rx_h_action_return)
2821 		CALL_RXH(ieee80211_rx_h_mgmt)
2822 
2823  rxh_next:
2824 		ieee80211_rx_handlers_result(rx, res);
2825 		spin_lock(&rx->local->rx_skb_queue.lock);
2826 #undef CALL_RXH
2827 	}
2828 
2829 	rx->local->running_rx_handler = false;
2830 
2831  unlock:
2832 	spin_unlock(&rx->local->rx_skb_queue.lock);
2833 }
2834 
2835 static void ieee80211_invoke_rx_handlers(struct ieee80211_rx_data *rx)
2836 {
2837 	ieee80211_rx_result res = RX_DROP_MONITOR;
2838 
2839 #define CALL_RXH(rxh)			\
2840 	do {				\
2841 		res = rxh(rx);		\
2842 		if (res != RX_CONTINUE)	\
2843 			goto rxh_next;  \
2844 	} while (0);
2845 
2846 	CALL_RXH(ieee80211_rx_h_check)
2847 
2848 	ieee80211_rx_reorder_ampdu(rx);
2849 
2850 	ieee80211_rx_handlers(rx);
2851 	return;
2852 
2853  rxh_next:
2854 	ieee80211_rx_handlers_result(rx, res);
2855 
2856 #undef CALL_RXH
2857 }
2858 
2859 /*
2860  * This function makes calls into the RX path, therefore
2861  * it has to be invoked under RCU read lock.
2862  */
2863 void ieee80211_release_reorder_timeout(struct sta_info *sta, int tid)
2864 {
2865 	struct ieee80211_rx_data rx = {
2866 		.sta = sta,
2867 		.sdata = sta->sdata,
2868 		.local = sta->local,
2869 		/* This is OK -- must be QoS data frame */
2870 		.security_idx = tid,
2871 		.seqno_idx = tid,
2872 		.flags = 0,
2873 	};
2874 	struct tid_ampdu_rx *tid_agg_rx;
2875 
2876 	tid_agg_rx = rcu_dereference(sta->ampdu_mlme.tid_rx[tid]);
2877 	if (!tid_agg_rx)
2878 		return;
2879 
2880 	spin_lock(&tid_agg_rx->reorder_lock);
2881 	ieee80211_sta_reorder_release(sta->sdata, tid_agg_rx);
2882 	spin_unlock(&tid_agg_rx->reorder_lock);
2883 
2884 	ieee80211_rx_handlers(&rx);
2885 }
2886 
2887 /* main receive path */
2888 
2889 static int prepare_for_handlers(struct ieee80211_rx_data *rx,
2890 				struct ieee80211_hdr *hdr)
2891 {
2892 	struct ieee80211_sub_if_data *sdata = rx->sdata;
2893 	struct sk_buff *skb = rx->skb;
2894 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
2895 	u8 *bssid = ieee80211_get_bssid(hdr, skb->len, sdata->vif.type);
2896 	int multicast = is_multicast_ether_addr(hdr->addr1);
2897 
2898 	switch (sdata->vif.type) {
2899 	case NL80211_IFTYPE_STATION:
2900 		if (!bssid && !sdata->u.mgd.use_4addr)
2901 			return 0;
2902 		if (!multicast &&
2903 		    !ether_addr_equal(sdata->vif.addr, hdr->addr1)) {
2904 			if (!(sdata->dev->flags & IFF_PROMISC) ||
2905 			    sdata->u.mgd.use_4addr)
2906 				return 0;
2907 			status->rx_flags &= ~IEEE80211_RX_RA_MATCH;
2908 		}
2909 		break;
2910 	case NL80211_IFTYPE_ADHOC:
2911 		if (!bssid)
2912 			return 0;
2913 		if (ieee80211_is_beacon(hdr->frame_control)) {
2914 			return 1;
2915 		} else if (!ieee80211_bssid_match(bssid, sdata->u.ibss.bssid)) {
2916 			return 0;
2917 		} else if (!multicast &&
2918 			   !ether_addr_equal(sdata->vif.addr, hdr->addr1)) {
2919 			if (!(sdata->dev->flags & IFF_PROMISC))
2920 				return 0;
2921 			status->rx_flags &= ~IEEE80211_RX_RA_MATCH;
2922 		} else if (!rx->sta) {
2923 			int rate_idx;
2924 			if (status->flag & (RX_FLAG_HT | RX_FLAG_VHT))
2925 				rate_idx = 0; /* TODO: HT/VHT rates */
2926 			else
2927 				rate_idx = status->rate_idx;
2928 			ieee80211_ibss_rx_no_sta(sdata, bssid, hdr->addr2,
2929 						 BIT(rate_idx));
2930 		}
2931 		break;
2932 	case NL80211_IFTYPE_MESH_POINT:
2933 		if (!multicast &&
2934 		    !ether_addr_equal(sdata->vif.addr, hdr->addr1)) {
2935 			if (!(sdata->dev->flags & IFF_PROMISC))
2936 				return 0;
2937 
2938 			status->rx_flags &= ~IEEE80211_RX_RA_MATCH;
2939 		}
2940 		break;
2941 	case NL80211_IFTYPE_AP_VLAN:
2942 	case NL80211_IFTYPE_AP:
2943 		if (!bssid) {
2944 			if (!ether_addr_equal(sdata->vif.addr, hdr->addr1))
2945 				return 0;
2946 		} else if (!ieee80211_bssid_match(bssid, sdata->vif.addr)) {
2947 			/*
2948 			 * Accept public action frames even when the
2949 			 * BSSID doesn't match, this is used for P2P
2950 			 * and location updates. Note that mac80211
2951 			 * itself never looks at these frames.
2952 			 */
2953 			if (ieee80211_is_public_action(hdr, skb->len))
2954 				return 1;
2955 			if (!ieee80211_is_beacon(hdr->frame_control))
2956 				return 0;
2957 			status->rx_flags &= ~IEEE80211_RX_RA_MATCH;
2958 		}
2959 		break;
2960 	case NL80211_IFTYPE_WDS:
2961 		if (bssid || !ieee80211_is_data(hdr->frame_control))
2962 			return 0;
2963 		if (!ether_addr_equal(sdata->u.wds.remote_addr, hdr->addr2))
2964 			return 0;
2965 		break;
2966 	case NL80211_IFTYPE_P2P_DEVICE:
2967 		if (!ieee80211_is_public_action(hdr, skb->len) &&
2968 		    !ieee80211_is_probe_req(hdr->frame_control) &&
2969 		    !ieee80211_is_probe_resp(hdr->frame_control) &&
2970 		    !ieee80211_is_beacon(hdr->frame_control))
2971 			return 0;
2972 		if (!ether_addr_equal(sdata->vif.addr, hdr->addr1))
2973 			status->rx_flags &= ~IEEE80211_RX_RA_MATCH;
2974 		break;
2975 	default:
2976 		/* should never get here */
2977 		WARN_ON_ONCE(1);
2978 		break;
2979 	}
2980 
2981 	return 1;
2982 }
2983 
2984 /*
2985  * This function returns whether or not the SKB
2986  * was destined for RX processing or not, which,
2987  * if consume is true, is equivalent to whether
2988  * or not the skb was consumed.
2989  */
2990 static bool ieee80211_prepare_and_rx_handle(struct ieee80211_rx_data *rx,
2991 					    struct sk_buff *skb, bool consume)
2992 {
2993 	struct ieee80211_local *local = rx->local;
2994 	struct ieee80211_sub_if_data *sdata = rx->sdata;
2995 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
2996 	struct ieee80211_hdr *hdr = (void *)skb->data;
2997 	int prepares;
2998 
2999 	rx->skb = skb;
3000 	status->rx_flags |= IEEE80211_RX_RA_MATCH;
3001 	prepares = prepare_for_handlers(rx, hdr);
3002 
3003 	if (!prepares)
3004 		return false;
3005 
3006 	if (!consume) {
3007 		skb = skb_copy(skb, GFP_ATOMIC);
3008 		if (!skb) {
3009 			if (net_ratelimit())
3010 				wiphy_debug(local->hw.wiphy,
3011 					"failed to copy skb for %s\n",
3012 					sdata->name);
3013 			return true;
3014 		}
3015 
3016 		rx->skb = skb;
3017 	}
3018 
3019 	ieee80211_invoke_rx_handlers(rx);
3020 	return true;
3021 }
3022 
3023 /*
3024  * This is the actual Rx frames handler. as it blongs to Rx path it must
3025  * be called with rcu_read_lock protection.
3026  */
3027 static void __ieee80211_rx_handle_packet(struct ieee80211_hw *hw,
3028 					 struct sk_buff *skb)
3029 {
3030 	struct ieee80211_local *local = hw_to_local(hw);
3031 	struct ieee80211_sub_if_data *sdata;
3032 	struct ieee80211_hdr *hdr;
3033 	__le16 fc;
3034 	struct ieee80211_rx_data rx;
3035 	struct ieee80211_sub_if_data *prev;
3036 	struct sta_info *sta, *tmp, *prev_sta;
3037 	int err = 0;
3038 
3039 	fc = ((struct ieee80211_hdr *)skb->data)->frame_control;
3040 	memset(&rx, 0, sizeof(rx));
3041 	rx.skb = skb;
3042 	rx.local = local;
3043 
3044 	if (ieee80211_is_data(fc) || ieee80211_is_mgmt(fc))
3045 		local->dot11ReceivedFragmentCount++;
3046 
3047 	if (ieee80211_is_mgmt(fc)) {
3048 		/* drop frame if too short for header */
3049 		if (skb->len < ieee80211_hdrlen(fc))
3050 			err = -ENOBUFS;
3051 		else
3052 			err = skb_linearize(skb);
3053 	} else {
3054 		err = !pskb_may_pull(skb, ieee80211_hdrlen(fc));
3055 	}
3056 
3057 	if (err) {
3058 		dev_kfree_skb(skb);
3059 		return;
3060 	}
3061 
3062 	hdr = (struct ieee80211_hdr *)skb->data;
3063 	ieee80211_parse_qos(&rx);
3064 	ieee80211_verify_alignment(&rx);
3065 
3066 	if (unlikely(ieee80211_is_probe_resp(hdr->frame_control) ||
3067 		     ieee80211_is_beacon(hdr->frame_control)))
3068 		ieee80211_scan_rx(local, skb);
3069 
3070 	if (ieee80211_is_data(fc)) {
3071 		prev_sta = NULL;
3072 
3073 		for_each_sta_info(local, hdr->addr2, sta, tmp) {
3074 			if (!prev_sta) {
3075 				prev_sta = sta;
3076 				continue;
3077 			}
3078 
3079 			rx.sta = prev_sta;
3080 			rx.sdata = prev_sta->sdata;
3081 			ieee80211_prepare_and_rx_handle(&rx, skb, false);
3082 
3083 			prev_sta = sta;
3084 		}
3085 
3086 		if (prev_sta) {
3087 			rx.sta = prev_sta;
3088 			rx.sdata = prev_sta->sdata;
3089 
3090 			if (ieee80211_prepare_and_rx_handle(&rx, skb, true))
3091 				return;
3092 			goto out;
3093 		}
3094 	}
3095 
3096 	prev = NULL;
3097 
3098 	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
3099 		if (!ieee80211_sdata_running(sdata))
3100 			continue;
3101 
3102 		if (sdata->vif.type == NL80211_IFTYPE_MONITOR ||
3103 		    sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
3104 			continue;
3105 
3106 		/*
3107 		 * frame is destined for this interface, but if it's
3108 		 * not also for the previous one we handle that after
3109 		 * the loop to avoid copying the SKB once too much
3110 		 */
3111 
3112 		if (!prev) {
3113 			prev = sdata;
3114 			continue;
3115 		}
3116 
3117 		rx.sta = sta_info_get_bss(prev, hdr->addr2);
3118 		rx.sdata = prev;
3119 		ieee80211_prepare_and_rx_handle(&rx, skb, false);
3120 
3121 		prev = sdata;
3122 	}
3123 
3124 	if (prev) {
3125 		rx.sta = sta_info_get_bss(prev, hdr->addr2);
3126 		rx.sdata = prev;
3127 
3128 		if (ieee80211_prepare_and_rx_handle(&rx, skb, true))
3129 			return;
3130 	}
3131 
3132  out:
3133 	dev_kfree_skb(skb);
3134 }
3135 
3136 /*
3137  * This is the receive path handler. It is called by a low level driver when an
3138  * 802.11 MPDU is received from the hardware.
3139  */
3140 void ieee80211_rx(struct ieee80211_hw *hw, struct sk_buff *skb)
3141 {
3142 	struct ieee80211_local *local = hw_to_local(hw);
3143 	struct ieee80211_rate *rate = NULL;
3144 	struct ieee80211_supported_band *sband;
3145 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
3146 
3147 	WARN_ON_ONCE(softirq_count() == 0);
3148 
3149 	if (WARN_ON(status->band >= IEEE80211_NUM_BANDS))
3150 		goto drop;
3151 
3152 	sband = local->hw.wiphy->bands[status->band];
3153 	if (WARN_ON(!sband))
3154 		goto drop;
3155 
3156 	/*
3157 	 * If we're suspending, it is possible although not too likely
3158 	 * that we'd be receiving frames after having already partially
3159 	 * quiesced the stack. We can't process such frames then since
3160 	 * that might, for example, cause stations to be added or other
3161 	 * driver callbacks be invoked.
3162 	 */
3163 	if (unlikely(local->quiescing || local->suspended))
3164 		goto drop;
3165 
3166 	/* We might be during a HW reconfig, prevent Rx for the same reason */
3167 	if (unlikely(local->in_reconfig))
3168 		goto drop;
3169 
3170 	/*
3171 	 * The same happens when we're not even started,
3172 	 * but that's worth a warning.
3173 	 */
3174 	if (WARN_ON(!local->started))
3175 		goto drop;
3176 
3177 	if (likely(!(status->flag & RX_FLAG_FAILED_PLCP_CRC))) {
3178 		/*
3179 		 * Validate the rate, unless a PLCP error means that
3180 		 * we probably can't have a valid rate here anyway.
3181 		 */
3182 
3183 		if (status->flag & RX_FLAG_HT) {
3184 			/*
3185 			 * rate_idx is MCS index, which can be [0-76]
3186 			 * as documented on:
3187 			 *
3188 			 * http://wireless.kernel.org/en/developers/Documentation/ieee80211/802.11n
3189 			 *
3190 			 * Anything else would be some sort of driver or
3191 			 * hardware error. The driver should catch hardware
3192 			 * errors.
3193 			 */
3194 			if (WARN(status->rate_idx > 76,
3195 				 "Rate marked as an HT rate but passed "
3196 				 "status->rate_idx is not "
3197 				 "an MCS index [0-76]: %d (0x%02x)\n",
3198 				 status->rate_idx,
3199 				 status->rate_idx))
3200 				goto drop;
3201 		} else if (status->flag & RX_FLAG_VHT) {
3202 			if (WARN_ONCE(status->rate_idx > 9 ||
3203 				      !status->vht_nss ||
3204 				      status->vht_nss > 8,
3205 				      "Rate marked as a VHT rate but data is invalid: MCS: %d, NSS: %d\n",
3206 				      status->rate_idx, status->vht_nss))
3207 				goto drop;
3208 		} else {
3209 			if (WARN_ON(status->rate_idx >= sband->n_bitrates))
3210 				goto drop;
3211 			rate = &sband->bitrates[status->rate_idx];
3212 		}
3213 	}
3214 
3215 	status->rx_flags = 0;
3216 
3217 	/*
3218 	 * key references and virtual interfaces are protected using RCU
3219 	 * and this requires that we are in a read-side RCU section during
3220 	 * receive processing
3221 	 */
3222 	rcu_read_lock();
3223 
3224 	/*
3225 	 * Frames with failed FCS/PLCP checksum are not returned,
3226 	 * all other frames are returned without radiotap header
3227 	 * if it was previously present.
3228 	 * Also, frames with less than 16 bytes are dropped.
3229 	 */
3230 	skb = ieee80211_rx_monitor(local, skb, rate);
3231 	if (!skb) {
3232 		rcu_read_unlock();
3233 		return;
3234 	}
3235 
3236 	ieee80211_tpt_led_trig_rx(local,
3237 			((struct ieee80211_hdr *)skb->data)->frame_control,
3238 			skb->len);
3239 	__ieee80211_rx_handle_packet(hw, skb);
3240 
3241 	rcu_read_unlock();
3242 
3243 	return;
3244  drop:
3245 	kfree_skb(skb);
3246 }
3247 EXPORT_SYMBOL(ieee80211_rx);
3248 
3249 /* This is a version of the rx handler that can be called from hard irq
3250  * context. Post the skb on the queue and schedule the tasklet */
3251 void ieee80211_rx_irqsafe(struct ieee80211_hw *hw, struct sk_buff *skb)
3252 {
3253 	struct ieee80211_local *local = hw_to_local(hw);
3254 
3255 	BUILD_BUG_ON(sizeof(struct ieee80211_rx_status) > sizeof(skb->cb));
3256 
3257 	skb->pkt_type = IEEE80211_RX_MSG;
3258 	skb_queue_tail(&local->skb_queue, skb);
3259 	tasklet_schedule(&local->tasklet);
3260 }
3261 EXPORT_SYMBOL(ieee80211_rx_irqsafe);
3262