xref: /linux/net/mac80211/rx.c (revision f49f4ab95c301dbccad0efe85296d908b8ae7ad4)
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 	if (local->hw.flags & IEEE80211_HW_RX_INCLUDES_FCS) {
44 		if (likely(skb->len > FCS_LEN))
45 			__pskb_trim(skb, skb->len - FCS_LEN);
46 		else {
47 			/* driver bug */
48 			WARN_ON(1);
49 			dev_kfree_skb(skb);
50 			skb = NULL;
51 		}
52 	}
53 
54 	return skb;
55 }
56 
57 static inline int should_drop_frame(struct sk_buff *skb,
58 				    int present_fcs_len)
59 {
60 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
61 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
62 
63 	if (status->flag & (RX_FLAG_FAILED_FCS_CRC |
64 			    RX_FLAG_FAILED_PLCP_CRC |
65 			    RX_FLAG_AMPDU_IS_ZEROLEN))
66 		return 1;
67 	if (unlikely(skb->len < 16 + present_fcs_len))
68 		return 1;
69 	if (ieee80211_is_ctl(hdr->frame_control) &&
70 	    !ieee80211_is_pspoll(hdr->frame_control) &&
71 	    !ieee80211_is_back_req(hdr->frame_control))
72 		return 1;
73 	return 0;
74 }
75 
76 static int
77 ieee80211_rx_radiotap_len(struct ieee80211_local *local,
78 			  struct ieee80211_rx_status *status)
79 {
80 	int len;
81 
82 	/* always present fields */
83 	len = sizeof(struct ieee80211_radiotap_header) + 9;
84 
85 	if (status->flag & RX_FLAG_MACTIME_MPDU)
86 		len += 8;
87 	if (local->hw.flags & IEEE80211_HW_SIGNAL_DBM)
88 		len += 1;
89 
90 	if (len & 1) /* padding for RX_FLAGS if necessary */
91 		len++;
92 
93 	if (status->flag & RX_FLAG_HT) /* HT info */
94 		len += 3;
95 
96 	if (status->flag & RX_FLAG_AMPDU_DETAILS) {
97 		/* padding */
98 		while (len & 3)
99 			len++;
100 		len += 8;
101 	}
102 
103 	return len;
104 }
105 
106 /*
107  * ieee80211_add_rx_radiotap_header - add radiotap header
108  *
109  * add a radiotap header containing all the fields which the hardware provided.
110  */
111 static void
112 ieee80211_add_rx_radiotap_header(struct ieee80211_local *local,
113 				 struct sk_buff *skb,
114 				 struct ieee80211_rate *rate,
115 				 int rtap_len, bool has_fcs)
116 {
117 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
118 	struct ieee80211_radiotap_header *rthdr;
119 	unsigned char *pos;
120 	u16 rx_flags = 0;
121 
122 	rthdr = (struct ieee80211_radiotap_header *)skb_push(skb, rtap_len);
123 	memset(rthdr, 0, rtap_len);
124 
125 	/* radiotap header, set always present flags */
126 	rthdr->it_present =
127 		cpu_to_le32((1 << IEEE80211_RADIOTAP_FLAGS) |
128 			    (1 << IEEE80211_RADIOTAP_CHANNEL) |
129 			    (1 << IEEE80211_RADIOTAP_ANTENNA) |
130 			    (1 << IEEE80211_RADIOTAP_RX_FLAGS));
131 	rthdr->it_len = cpu_to_le16(rtap_len);
132 
133 	pos = (unsigned char *)(rthdr+1);
134 
135 	/* the order of the following fields is important */
136 
137 	/* IEEE80211_RADIOTAP_TSFT */
138 	if (status->flag & RX_FLAG_MACTIME_MPDU) {
139 		put_unaligned_le64(status->mactime, pos);
140 		rthdr->it_present |=
141 			cpu_to_le32(1 << IEEE80211_RADIOTAP_TSFT);
142 		pos += 8;
143 	}
144 
145 	/* IEEE80211_RADIOTAP_FLAGS */
146 	if (has_fcs && (local->hw.flags & IEEE80211_HW_RX_INCLUDES_FCS))
147 		*pos |= IEEE80211_RADIOTAP_F_FCS;
148 	if (status->flag & (RX_FLAG_FAILED_FCS_CRC | RX_FLAG_FAILED_PLCP_CRC))
149 		*pos |= IEEE80211_RADIOTAP_F_BADFCS;
150 	if (status->flag & RX_FLAG_SHORTPRE)
151 		*pos |= IEEE80211_RADIOTAP_F_SHORTPRE;
152 	pos++;
153 
154 	/* IEEE80211_RADIOTAP_RATE */
155 	if (!rate || status->flag & RX_FLAG_HT) {
156 		/*
157 		 * Without rate information don't add it. If we have,
158 		 * MCS information is a separate field in radiotap,
159 		 * added below. The byte here is needed as padding
160 		 * for the channel though, so initialise it to 0.
161 		 */
162 		*pos = 0;
163 	} else {
164 		rthdr->it_present |= cpu_to_le32(1 << IEEE80211_RADIOTAP_RATE);
165 		*pos = rate->bitrate / 5;
166 	}
167 	pos++;
168 
169 	/* IEEE80211_RADIOTAP_CHANNEL */
170 	put_unaligned_le16(status->freq, pos);
171 	pos += 2;
172 	if (status->band == IEEE80211_BAND_5GHZ)
173 		put_unaligned_le16(IEEE80211_CHAN_OFDM | IEEE80211_CHAN_5GHZ,
174 				   pos);
175 	else if (status->flag & RX_FLAG_HT)
176 		put_unaligned_le16(IEEE80211_CHAN_DYN | IEEE80211_CHAN_2GHZ,
177 				   pos);
178 	else if (rate && rate->flags & IEEE80211_RATE_ERP_G)
179 		put_unaligned_le16(IEEE80211_CHAN_OFDM | IEEE80211_CHAN_2GHZ,
180 				   pos);
181 	else if (rate)
182 		put_unaligned_le16(IEEE80211_CHAN_CCK | IEEE80211_CHAN_2GHZ,
183 				   pos);
184 	else
185 		put_unaligned_le16(IEEE80211_CHAN_2GHZ, pos);
186 	pos += 2;
187 
188 	/* IEEE80211_RADIOTAP_DBM_ANTSIGNAL */
189 	if (local->hw.flags & IEEE80211_HW_SIGNAL_DBM &&
190 	    !(status->flag & RX_FLAG_NO_SIGNAL_VAL)) {
191 		*pos = status->signal;
192 		rthdr->it_present |=
193 			cpu_to_le32(1 << IEEE80211_RADIOTAP_DBM_ANTSIGNAL);
194 		pos++;
195 	}
196 
197 	/* IEEE80211_RADIOTAP_LOCK_QUALITY is missing */
198 
199 	/* IEEE80211_RADIOTAP_ANTENNA */
200 	*pos = status->antenna;
201 	pos++;
202 
203 	/* IEEE80211_RADIOTAP_DB_ANTNOISE is not used */
204 
205 	/* IEEE80211_RADIOTAP_RX_FLAGS */
206 	/* ensure 2 byte alignment for the 2 byte field as required */
207 	if ((pos - (u8 *)rthdr) & 1)
208 		pos++;
209 	if (status->flag & RX_FLAG_FAILED_PLCP_CRC)
210 		rx_flags |= IEEE80211_RADIOTAP_F_RX_BADPLCP;
211 	put_unaligned_le16(rx_flags, pos);
212 	pos += 2;
213 
214 	if (status->flag & RX_FLAG_HT) {
215 		rthdr->it_present |= cpu_to_le32(1 << IEEE80211_RADIOTAP_MCS);
216 		*pos++ = local->hw.radiotap_mcs_details;
217 		*pos = 0;
218 		if (status->flag & RX_FLAG_SHORT_GI)
219 			*pos |= IEEE80211_RADIOTAP_MCS_SGI;
220 		if (status->flag & RX_FLAG_40MHZ)
221 			*pos |= IEEE80211_RADIOTAP_MCS_BW_40;
222 		if (status->flag & RX_FLAG_HT_GF)
223 			*pos |= IEEE80211_RADIOTAP_MCS_FMT_GF;
224 		pos++;
225 		*pos++ = status->rate_idx;
226 	}
227 
228 	if (status->flag & RX_FLAG_AMPDU_DETAILS) {
229 		u16 flags = 0;
230 
231 		/* ensure 4 byte alignment */
232 		while ((pos - (u8 *)rthdr) & 3)
233 			pos++;
234 		rthdr->it_present |=
235 			cpu_to_le32(1 << IEEE80211_RADIOTAP_AMPDU_STATUS);
236 		put_unaligned_le32(status->ampdu_reference, pos);
237 		pos += 4;
238 		if (status->flag & RX_FLAG_AMPDU_REPORT_ZEROLEN)
239 			flags |= IEEE80211_RADIOTAP_AMPDU_REPORT_ZEROLEN;
240 		if (status->flag & RX_FLAG_AMPDU_IS_ZEROLEN)
241 			flags |= IEEE80211_RADIOTAP_AMPDU_IS_ZEROLEN;
242 		if (status->flag & RX_FLAG_AMPDU_LAST_KNOWN)
243 			flags |= IEEE80211_RADIOTAP_AMPDU_LAST_KNOWN;
244 		if (status->flag & RX_FLAG_AMPDU_IS_LAST)
245 			flags |= IEEE80211_RADIOTAP_AMPDU_IS_LAST;
246 		if (status->flag & RX_FLAG_AMPDU_DELIM_CRC_ERROR)
247 			flags |= IEEE80211_RADIOTAP_AMPDU_DELIM_CRC_ERR;
248 		if (status->flag & RX_FLAG_AMPDU_DELIM_CRC_KNOWN)
249 			flags |= IEEE80211_RADIOTAP_AMPDU_DELIM_CRC_KNOWN;
250 		put_unaligned_le16(flags, pos);
251 		pos += 2;
252 		if (status->flag & RX_FLAG_AMPDU_DELIM_CRC_KNOWN)
253 			*pos++ = status->ampdu_delimiter_crc;
254 		else
255 			*pos++ = 0;
256 		*pos++ = 0;
257 	}
258 }
259 
260 /*
261  * This function copies a received frame to all monitor interfaces and
262  * returns a cleaned-up SKB that no longer includes the FCS nor the
263  * radiotap header the driver might have added.
264  */
265 static struct sk_buff *
266 ieee80211_rx_monitor(struct ieee80211_local *local, struct sk_buff *origskb,
267 		     struct ieee80211_rate *rate)
268 {
269 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(origskb);
270 	struct ieee80211_sub_if_data *sdata;
271 	int needed_headroom;
272 	struct sk_buff *skb, *skb2;
273 	struct net_device *prev_dev = NULL;
274 	int present_fcs_len = 0;
275 
276 	/*
277 	 * First, we may need to make a copy of the skb because
278 	 *  (1) we need to modify it for radiotap (if not present), and
279 	 *  (2) the other RX handlers will modify the skb we got.
280 	 *
281 	 * We don't need to, of course, if we aren't going to return
282 	 * the SKB because it has a bad FCS/PLCP checksum.
283 	 */
284 
285 	/* room for the radiotap header based on driver features */
286 	needed_headroom = ieee80211_rx_radiotap_len(local, status);
287 
288 	if (local->hw.flags & IEEE80211_HW_RX_INCLUDES_FCS)
289 		present_fcs_len = FCS_LEN;
290 
291 	/* make sure hdr->frame_control is on the linear part */
292 	if (!pskb_may_pull(origskb, 2)) {
293 		dev_kfree_skb(origskb);
294 		return NULL;
295 	}
296 
297 	if (!local->monitors) {
298 		if (should_drop_frame(origskb, present_fcs_len)) {
299 			dev_kfree_skb(origskb);
300 			return NULL;
301 		}
302 
303 		return remove_monitor_info(local, origskb);
304 	}
305 
306 	if (should_drop_frame(origskb, present_fcs_len)) {
307 		/* only need to expand headroom if necessary */
308 		skb = origskb;
309 		origskb = NULL;
310 
311 		/*
312 		 * This shouldn't trigger often because most devices have an
313 		 * RX header they pull before we get here, and that should
314 		 * be big enough for our radiotap information. We should
315 		 * probably export the length to drivers so that we can have
316 		 * them allocate enough headroom to start with.
317 		 */
318 		if (skb_headroom(skb) < needed_headroom &&
319 		    pskb_expand_head(skb, needed_headroom, 0, GFP_ATOMIC)) {
320 			dev_kfree_skb(skb);
321 			return NULL;
322 		}
323 	} else {
324 		/*
325 		 * Need to make a copy and possibly remove radiotap header
326 		 * and FCS from the original.
327 		 */
328 		skb = skb_copy_expand(origskb, needed_headroom, 0, GFP_ATOMIC);
329 
330 		origskb = remove_monitor_info(local, origskb);
331 
332 		if (!skb)
333 			return origskb;
334 	}
335 
336 	/* prepend radiotap information */
337 	ieee80211_add_rx_radiotap_header(local, skb, rate, needed_headroom,
338 					 true);
339 
340 	skb_reset_mac_header(skb);
341 	skb->ip_summed = CHECKSUM_UNNECESSARY;
342 	skb->pkt_type = PACKET_OTHERHOST;
343 	skb->protocol = htons(ETH_P_802_2);
344 
345 	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
346 		if (sdata->vif.type != NL80211_IFTYPE_MONITOR)
347 			continue;
348 
349 		if (sdata->u.mntr_flags & MONITOR_FLAG_COOK_FRAMES)
350 			continue;
351 
352 		if (!ieee80211_sdata_running(sdata))
353 			continue;
354 
355 		if (prev_dev) {
356 			skb2 = skb_clone(skb, GFP_ATOMIC);
357 			if (skb2) {
358 				skb2->dev = prev_dev;
359 				netif_receive_skb(skb2);
360 			}
361 		}
362 
363 		prev_dev = sdata->dev;
364 		sdata->dev->stats.rx_packets++;
365 		sdata->dev->stats.rx_bytes += skb->len;
366 	}
367 
368 	if (prev_dev) {
369 		skb->dev = prev_dev;
370 		netif_receive_skb(skb);
371 	} else
372 		dev_kfree_skb(skb);
373 
374 	return origskb;
375 }
376 
377 
378 static void ieee80211_parse_qos(struct ieee80211_rx_data *rx)
379 {
380 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
381 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
382 	int tid, seqno_idx, security_idx;
383 
384 	/* does the frame have a qos control field? */
385 	if (ieee80211_is_data_qos(hdr->frame_control)) {
386 		u8 *qc = ieee80211_get_qos_ctl(hdr);
387 		/* frame has qos control */
388 		tid = *qc & IEEE80211_QOS_CTL_TID_MASK;
389 		if (*qc & IEEE80211_QOS_CTL_A_MSDU_PRESENT)
390 			status->rx_flags |= IEEE80211_RX_AMSDU;
391 
392 		seqno_idx = tid;
393 		security_idx = tid;
394 	} else {
395 		/*
396 		 * IEEE 802.11-2007, 7.1.3.4.1 ("Sequence Number field"):
397 		 *
398 		 *	Sequence numbers for management frames, QoS data
399 		 *	frames with a broadcast/multicast address in the
400 		 *	Address 1 field, and all non-QoS data frames sent
401 		 *	by QoS STAs are assigned using an additional single
402 		 *	modulo-4096 counter, [...]
403 		 *
404 		 * We also use that counter for non-QoS STAs.
405 		 */
406 		seqno_idx = NUM_RX_DATA_QUEUES;
407 		security_idx = 0;
408 		if (ieee80211_is_mgmt(hdr->frame_control))
409 			security_idx = NUM_RX_DATA_QUEUES;
410 		tid = 0;
411 	}
412 
413 	rx->seqno_idx = seqno_idx;
414 	rx->security_idx = security_idx;
415 	/* Set skb->priority to 1d tag if highest order bit of TID is not set.
416 	 * For now, set skb->priority to 0 for other cases. */
417 	rx->skb->priority = (tid > 7) ? 0 : tid;
418 }
419 
420 /**
421  * DOC: Packet alignment
422  *
423  * Drivers always need to pass packets that are aligned to two-byte boundaries
424  * to the stack.
425  *
426  * Additionally, should, if possible, align the payload data in a way that
427  * guarantees that the contained IP header is aligned to a four-byte
428  * boundary. In the case of regular frames, this simply means aligning the
429  * payload to a four-byte boundary (because either the IP header is directly
430  * contained, or IV/RFC1042 headers that have a length divisible by four are
431  * in front of it).  If the payload data is not properly aligned and the
432  * architecture doesn't support efficient unaligned operations, mac80211
433  * will align the data.
434  *
435  * With A-MSDU frames, however, the payload data address must yield two modulo
436  * four because there are 14-byte 802.3 headers within the A-MSDU frames that
437  * push the IP header further back to a multiple of four again. Thankfully, the
438  * specs were sane enough this time around to require padding each A-MSDU
439  * subframe to a length that is a multiple of four.
440  *
441  * Padding like Atheros hardware adds which is between the 802.11 header and
442  * the payload is not supported, the driver is required to move the 802.11
443  * header to be directly in front of the payload in that case.
444  */
445 static void ieee80211_verify_alignment(struct ieee80211_rx_data *rx)
446 {
447 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG
448 	WARN_ONCE((unsigned long)rx->skb->data & 1,
449 		  "unaligned packet at 0x%p\n", rx->skb->data);
450 #endif
451 }
452 
453 
454 /* rx handlers */
455 
456 static int ieee80211_is_unicast_robust_mgmt_frame(struct sk_buff *skb)
457 {
458 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
459 
460 	if (skb->len < 24 || is_multicast_ether_addr(hdr->addr1))
461 		return 0;
462 
463 	return ieee80211_is_robust_mgmt_frame(hdr);
464 }
465 
466 
467 static int ieee80211_is_multicast_robust_mgmt_frame(struct sk_buff *skb)
468 {
469 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
470 
471 	if (skb->len < 24 || !is_multicast_ether_addr(hdr->addr1))
472 		return 0;
473 
474 	return ieee80211_is_robust_mgmt_frame(hdr);
475 }
476 
477 
478 /* Get the BIP key index from MMIE; return -1 if this is not a BIP frame */
479 static int ieee80211_get_mmie_keyidx(struct sk_buff *skb)
480 {
481 	struct ieee80211_mgmt *hdr = (struct ieee80211_mgmt *) skb->data;
482 	struct ieee80211_mmie *mmie;
483 
484 	if (skb->len < 24 + sizeof(*mmie) ||
485 	    !is_multicast_ether_addr(hdr->da))
486 		return -1;
487 
488 	if (!ieee80211_is_robust_mgmt_frame((struct ieee80211_hdr *) hdr))
489 		return -1; /* not a robust management frame */
490 
491 	mmie = (struct ieee80211_mmie *)
492 		(skb->data + skb->len - sizeof(*mmie));
493 	if (mmie->element_id != WLAN_EID_MMIE ||
494 	    mmie->length != sizeof(*mmie) - 2)
495 		return -1;
496 
497 	return le16_to_cpu(mmie->key_id);
498 }
499 
500 
501 static ieee80211_rx_result
502 ieee80211_rx_mesh_check(struct ieee80211_rx_data *rx)
503 {
504 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
505 	char *dev_addr = rx->sdata->vif.addr;
506 
507 	if (ieee80211_is_data(hdr->frame_control)) {
508 		if (is_multicast_ether_addr(hdr->addr1)) {
509 			if (ieee80211_has_tods(hdr->frame_control) ||
510 				!ieee80211_has_fromds(hdr->frame_control))
511 				return RX_DROP_MONITOR;
512 			if (ether_addr_equal(hdr->addr3, dev_addr))
513 				return RX_DROP_MONITOR;
514 		} else {
515 			if (!ieee80211_has_a4(hdr->frame_control))
516 				return RX_DROP_MONITOR;
517 			if (ether_addr_equal(hdr->addr4, dev_addr))
518 				return RX_DROP_MONITOR;
519 		}
520 	}
521 
522 	/* If there is not an established peer link and this is not a peer link
523 	 * establisment frame, beacon or probe, drop the frame.
524 	 */
525 
526 	if (!rx->sta || sta_plink_state(rx->sta) != NL80211_PLINK_ESTAB) {
527 		struct ieee80211_mgmt *mgmt;
528 
529 		if (!ieee80211_is_mgmt(hdr->frame_control))
530 			return RX_DROP_MONITOR;
531 
532 		if (ieee80211_is_action(hdr->frame_control)) {
533 			u8 category;
534 			mgmt = (struct ieee80211_mgmt *)hdr;
535 			category = mgmt->u.action.category;
536 			if (category != WLAN_CATEGORY_MESH_ACTION &&
537 				category != WLAN_CATEGORY_SELF_PROTECTED)
538 				return RX_DROP_MONITOR;
539 			return RX_CONTINUE;
540 		}
541 
542 		if (ieee80211_is_probe_req(hdr->frame_control) ||
543 		    ieee80211_is_probe_resp(hdr->frame_control) ||
544 		    ieee80211_is_beacon(hdr->frame_control) ||
545 		    ieee80211_is_auth(hdr->frame_control))
546 			return RX_CONTINUE;
547 
548 		return RX_DROP_MONITOR;
549 
550 	}
551 
552 	return RX_CONTINUE;
553 }
554 
555 #define SEQ_MODULO 0x1000
556 #define SEQ_MASK   0xfff
557 
558 static inline int seq_less(u16 sq1, u16 sq2)
559 {
560 	return ((sq1 - sq2) & SEQ_MASK) > (SEQ_MODULO >> 1);
561 }
562 
563 static inline u16 seq_inc(u16 sq)
564 {
565 	return (sq + 1) & SEQ_MASK;
566 }
567 
568 static inline u16 seq_sub(u16 sq1, u16 sq2)
569 {
570 	return (sq1 - sq2) & SEQ_MASK;
571 }
572 
573 
574 static void ieee80211_release_reorder_frame(struct ieee80211_sub_if_data *sdata,
575 					    struct tid_ampdu_rx *tid_agg_rx,
576 					    int index)
577 {
578 	struct ieee80211_local *local = sdata->local;
579 	struct sk_buff *skb = tid_agg_rx->reorder_buf[index];
580 	struct ieee80211_rx_status *status;
581 
582 	lockdep_assert_held(&tid_agg_rx->reorder_lock);
583 
584 	if (!skb)
585 		goto no_frame;
586 
587 	/* release the frame from the reorder ring buffer */
588 	tid_agg_rx->stored_mpdu_num--;
589 	tid_agg_rx->reorder_buf[index] = NULL;
590 	status = IEEE80211_SKB_RXCB(skb);
591 	status->rx_flags |= IEEE80211_RX_DEFERRED_RELEASE;
592 	skb_queue_tail(&local->rx_skb_queue, skb);
593 
594 no_frame:
595 	tid_agg_rx->head_seq_num = seq_inc(tid_agg_rx->head_seq_num);
596 }
597 
598 static void ieee80211_release_reorder_frames(struct ieee80211_sub_if_data *sdata,
599 					     struct tid_ampdu_rx *tid_agg_rx,
600 					     u16 head_seq_num)
601 {
602 	int index;
603 
604 	lockdep_assert_held(&tid_agg_rx->reorder_lock);
605 
606 	while (seq_less(tid_agg_rx->head_seq_num, head_seq_num)) {
607 		index = seq_sub(tid_agg_rx->head_seq_num, tid_agg_rx->ssn) %
608 							tid_agg_rx->buf_size;
609 		ieee80211_release_reorder_frame(sdata, tid_agg_rx, index);
610 	}
611 }
612 
613 /*
614  * Timeout (in jiffies) for skb's that are waiting in the RX reorder buffer. If
615  * the skb was added to the buffer longer than this time ago, the earlier
616  * frames that have not yet been received are assumed to be lost and the skb
617  * can be released for processing. This may also release other skb's from the
618  * reorder buffer if there are no additional gaps between the frames.
619  *
620  * Callers must hold tid_agg_rx->reorder_lock.
621  */
622 #define HT_RX_REORDER_BUF_TIMEOUT (HZ / 10)
623 
624 static void ieee80211_sta_reorder_release(struct ieee80211_sub_if_data *sdata,
625 					  struct tid_ampdu_rx *tid_agg_rx)
626 {
627 	int index, j;
628 
629 	lockdep_assert_held(&tid_agg_rx->reorder_lock);
630 
631 	/* release the buffer until next missing frame */
632 	index = seq_sub(tid_agg_rx->head_seq_num, tid_agg_rx->ssn) %
633 						tid_agg_rx->buf_size;
634 	if (!tid_agg_rx->reorder_buf[index] &&
635 	    tid_agg_rx->stored_mpdu_num) {
636 		/*
637 		 * No buffers ready to be released, but check whether any
638 		 * frames in the reorder buffer have timed out.
639 		 */
640 		int skipped = 1;
641 		for (j = (index + 1) % tid_agg_rx->buf_size; j != index;
642 		     j = (j + 1) % tid_agg_rx->buf_size) {
643 			if (!tid_agg_rx->reorder_buf[j]) {
644 				skipped++;
645 				continue;
646 			}
647 			if (skipped &&
648 			    !time_after(jiffies, tid_agg_rx->reorder_time[j] +
649 					HT_RX_REORDER_BUF_TIMEOUT))
650 				goto set_release_timer;
651 
652 			ht_dbg_ratelimited(sdata,
653 					   "release an RX reorder frame due to timeout on earlier frames\n");
654 			ieee80211_release_reorder_frame(sdata, tid_agg_rx, j);
655 
656 			/*
657 			 * Increment the head seq# also for the skipped slots.
658 			 */
659 			tid_agg_rx->head_seq_num =
660 				(tid_agg_rx->head_seq_num + skipped) & SEQ_MASK;
661 			skipped = 0;
662 		}
663 	} else while (tid_agg_rx->reorder_buf[index]) {
664 		ieee80211_release_reorder_frame(sdata, tid_agg_rx, index);
665 		index =	seq_sub(tid_agg_rx->head_seq_num, tid_agg_rx->ssn) %
666 							tid_agg_rx->buf_size;
667 	}
668 
669 	if (tid_agg_rx->stored_mpdu_num) {
670 		j = index = seq_sub(tid_agg_rx->head_seq_num,
671 				    tid_agg_rx->ssn) % tid_agg_rx->buf_size;
672 
673 		for (; j != (index - 1) % tid_agg_rx->buf_size;
674 		     j = (j + 1) % tid_agg_rx->buf_size) {
675 			if (tid_agg_rx->reorder_buf[j])
676 				break;
677 		}
678 
679  set_release_timer:
680 
681 		mod_timer(&tid_agg_rx->reorder_timer,
682 			  tid_agg_rx->reorder_time[j] + 1 +
683 			  HT_RX_REORDER_BUF_TIMEOUT);
684 	} else {
685 		del_timer(&tid_agg_rx->reorder_timer);
686 	}
687 }
688 
689 /*
690  * As this function belongs to the RX path it must be under
691  * rcu_read_lock protection. It returns false if the frame
692  * can be processed immediately, true if it was consumed.
693  */
694 static bool ieee80211_sta_manage_reorder_buf(struct ieee80211_sub_if_data *sdata,
695 					     struct tid_ampdu_rx *tid_agg_rx,
696 					     struct sk_buff *skb)
697 {
698 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
699 	u16 sc = le16_to_cpu(hdr->seq_ctrl);
700 	u16 mpdu_seq_num = (sc & IEEE80211_SCTL_SEQ) >> 4;
701 	u16 head_seq_num, buf_size;
702 	int index;
703 	bool ret = true;
704 
705 	spin_lock(&tid_agg_rx->reorder_lock);
706 
707 	buf_size = tid_agg_rx->buf_size;
708 	head_seq_num = tid_agg_rx->head_seq_num;
709 
710 	/* frame with out of date sequence number */
711 	if (seq_less(mpdu_seq_num, head_seq_num)) {
712 		dev_kfree_skb(skb);
713 		goto out;
714 	}
715 
716 	/*
717 	 * If frame the sequence number exceeds our buffering window
718 	 * size release some previous frames to make room for this one.
719 	 */
720 	if (!seq_less(mpdu_seq_num, head_seq_num + buf_size)) {
721 		head_seq_num = seq_inc(seq_sub(mpdu_seq_num, buf_size));
722 		/* release stored frames up to new head to stack */
723 		ieee80211_release_reorder_frames(sdata, tid_agg_rx,
724 						 head_seq_num);
725 	}
726 
727 	/* Now the new frame is always in the range of the reordering buffer */
728 
729 	index = seq_sub(mpdu_seq_num, tid_agg_rx->ssn) % tid_agg_rx->buf_size;
730 
731 	/* check if we already stored this frame */
732 	if (tid_agg_rx->reorder_buf[index]) {
733 		dev_kfree_skb(skb);
734 		goto out;
735 	}
736 
737 	/*
738 	 * If the current MPDU is in the right order and nothing else
739 	 * is stored we can process it directly, no need to buffer it.
740 	 * If it is first but there's something stored, we may be able
741 	 * to release frames after this one.
742 	 */
743 	if (mpdu_seq_num == tid_agg_rx->head_seq_num &&
744 	    tid_agg_rx->stored_mpdu_num == 0) {
745 		tid_agg_rx->head_seq_num = seq_inc(tid_agg_rx->head_seq_num);
746 		ret = false;
747 		goto out;
748 	}
749 
750 	/* put the frame in the reordering buffer */
751 	tid_agg_rx->reorder_buf[index] = skb;
752 	tid_agg_rx->reorder_time[index] = jiffies;
753 	tid_agg_rx->stored_mpdu_num++;
754 	ieee80211_sta_reorder_release(sdata, tid_agg_rx);
755 
756  out:
757 	spin_unlock(&tid_agg_rx->reorder_lock);
758 	return ret;
759 }
760 
761 /*
762  * Reorder MPDUs from A-MPDUs, keeping them on a buffer. Returns
763  * true if the MPDU was buffered, false if it should be processed.
764  */
765 static void ieee80211_rx_reorder_ampdu(struct ieee80211_rx_data *rx)
766 {
767 	struct sk_buff *skb = rx->skb;
768 	struct ieee80211_local *local = rx->local;
769 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
770 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
771 	struct sta_info *sta = rx->sta;
772 	struct tid_ampdu_rx *tid_agg_rx;
773 	u16 sc;
774 	u8 tid, ack_policy;
775 
776 	if (!ieee80211_is_data_qos(hdr->frame_control))
777 		goto dont_reorder;
778 
779 	/*
780 	 * filter the QoS data rx stream according to
781 	 * STA/TID and check if this STA/TID is on aggregation
782 	 */
783 
784 	if (!sta)
785 		goto dont_reorder;
786 
787 	ack_policy = *ieee80211_get_qos_ctl(hdr) &
788 		     IEEE80211_QOS_CTL_ACK_POLICY_MASK;
789 	tid = *ieee80211_get_qos_ctl(hdr) & IEEE80211_QOS_CTL_TID_MASK;
790 
791 	tid_agg_rx = rcu_dereference(sta->ampdu_mlme.tid_rx[tid]);
792 	if (!tid_agg_rx)
793 		goto dont_reorder;
794 
795 	/* qos null data frames are excluded */
796 	if (unlikely(hdr->frame_control & cpu_to_le16(IEEE80211_STYPE_NULLFUNC)))
797 		goto dont_reorder;
798 
799 	/* not part of a BA session */
800 	if (ack_policy != IEEE80211_QOS_CTL_ACK_POLICY_BLOCKACK &&
801 	    ack_policy != IEEE80211_QOS_CTL_ACK_POLICY_NORMAL)
802 		goto dont_reorder;
803 
804 	/* not actually part of this BA session */
805 	if (!(status->rx_flags & IEEE80211_RX_RA_MATCH))
806 		goto dont_reorder;
807 
808 	/* new, potentially un-ordered, ampdu frame - process it */
809 
810 	/* reset session timer */
811 	if (tid_agg_rx->timeout)
812 		tid_agg_rx->last_rx = jiffies;
813 
814 	/* if this mpdu is fragmented - terminate rx aggregation session */
815 	sc = le16_to_cpu(hdr->seq_ctrl);
816 	if (sc & IEEE80211_SCTL_FRAG) {
817 		skb->pkt_type = IEEE80211_SDATA_QUEUE_TYPE_FRAME;
818 		skb_queue_tail(&rx->sdata->skb_queue, skb);
819 		ieee80211_queue_work(&local->hw, &rx->sdata->work);
820 		return;
821 	}
822 
823 	/*
824 	 * No locking needed -- we will only ever process one
825 	 * RX packet at a time, and thus own tid_agg_rx. All
826 	 * other code manipulating it needs to (and does) make
827 	 * sure that we cannot get to it any more before doing
828 	 * anything with it.
829 	 */
830 	if (ieee80211_sta_manage_reorder_buf(rx->sdata, tid_agg_rx, skb))
831 		return;
832 
833  dont_reorder:
834 	skb_queue_tail(&local->rx_skb_queue, skb);
835 }
836 
837 static ieee80211_rx_result debug_noinline
838 ieee80211_rx_h_check(struct ieee80211_rx_data *rx)
839 {
840 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
841 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
842 
843 	/* Drop duplicate 802.11 retransmissions (IEEE 802.11 Chap. 9.2.9) */
844 	if (rx->sta && !is_multicast_ether_addr(hdr->addr1)) {
845 		if (unlikely(ieee80211_has_retry(hdr->frame_control) &&
846 			     rx->sta->last_seq_ctrl[rx->seqno_idx] ==
847 			     hdr->seq_ctrl)) {
848 			if (status->rx_flags & IEEE80211_RX_RA_MATCH) {
849 				rx->local->dot11FrameDuplicateCount++;
850 				rx->sta->num_duplicates++;
851 			}
852 			return RX_DROP_UNUSABLE;
853 		} else
854 			rx->sta->last_seq_ctrl[rx->seqno_idx] = hdr->seq_ctrl;
855 	}
856 
857 	if (unlikely(rx->skb->len < 16)) {
858 		I802_DEBUG_INC(rx->local->rx_handlers_drop_short);
859 		return RX_DROP_MONITOR;
860 	}
861 
862 	/* Drop disallowed frame classes based on STA auth/assoc state;
863 	 * IEEE 802.11, Chap 5.5.
864 	 *
865 	 * mac80211 filters only based on association state, i.e. it drops
866 	 * Class 3 frames from not associated stations. hostapd sends
867 	 * deauth/disassoc frames when needed. In addition, hostapd is
868 	 * responsible for filtering on both auth and assoc states.
869 	 */
870 
871 	if (ieee80211_vif_is_mesh(&rx->sdata->vif))
872 		return ieee80211_rx_mesh_check(rx);
873 
874 	if (unlikely((ieee80211_is_data(hdr->frame_control) ||
875 		      ieee80211_is_pspoll(hdr->frame_control)) &&
876 		     rx->sdata->vif.type != NL80211_IFTYPE_ADHOC &&
877 		     rx->sdata->vif.type != NL80211_IFTYPE_WDS &&
878 		     (!rx->sta || !test_sta_flag(rx->sta, WLAN_STA_ASSOC)))) {
879 		/*
880 		 * accept port control frames from the AP even when it's not
881 		 * yet marked ASSOC to prevent a race where we don't set the
882 		 * assoc bit quickly enough before it sends the first frame
883 		 */
884 		if (rx->sta && rx->sdata->vif.type == NL80211_IFTYPE_STATION &&
885 		    ieee80211_is_data_present(hdr->frame_control)) {
886 			u16 ethertype;
887 			u8 *payload;
888 
889 			payload = rx->skb->data +
890 				ieee80211_hdrlen(hdr->frame_control);
891 			ethertype = (payload[6] << 8) | payload[7];
892 			if (cpu_to_be16(ethertype) ==
893 			    rx->sdata->control_port_protocol)
894 				return RX_CONTINUE;
895 		}
896 
897 		if (rx->sdata->vif.type == NL80211_IFTYPE_AP &&
898 		    cfg80211_rx_spurious_frame(rx->sdata->dev,
899 					       hdr->addr2,
900 					       GFP_ATOMIC))
901 			return RX_DROP_UNUSABLE;
902 
903 		return RX_DROP_MONITOR;
904 	}
905 
906 	return RX_CONTINUE;
907 }
908 
909 
910 static ieee80211_rx_result debug_noinline
911 ieee80211_rx_h_decrypt(struct ieee80211_rx_data *rx)
912 {
913 	struct sk_buff *skb = rx->skb;
914 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
915 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
916 	int keyidx;
917 	int hdrlen;
918 	ieee80211_rx_result result = RX_DROP_UNUSABLE;
919 	struct ieee80211_key *sta_ptk = NULL;
920 	int mmie_keyidx = -1;
921 	__le16 fc;
922 
923 	/*
924 	 * Key selection 101
925 	 *
926 	 * There are four types of keys:
927 	 *  - GTK (group keys)
928 	 *  - IGTK (group keys for management frames)
929 	 *  - PTK (pairwise keys)
930 	 *  - STK (station-to-station pairwise keys)
931 	 *
932 	 * When selecting a key, we have to distinguish between multicast
933 	 * (including broadcast) and unicast frames, the latter can only
934 	 * use PTKs and STKs while the former always use GTKs and IGTKs.
935 	 * Unless, of course, actual WEP keys ("pre-RSNA") are used, then
936 	 * unicast frames can also use key indices like GTKs. Hence, if we
937 	 * don't have a PTK/STK we check the key index for a WEP key.
938 	 *
939 	 * Note that in a regular BSS, multicast frames are sent by the
940 	 * AP only, associated stations unicast the frame to the AP first
941 	 * which then multicasts it on their behalf.
942 	 *
943 	 * There is also a slight problem in IBSS mode: GTKs are negotiated
944 	 * with each station, that is something we don't currently handle.
945 	 * The spec seems to expect that one negotiates the same key with
946 	 * every station but there's no such requirement; VLANs could be
947 	 * possible.
948 	 */
949 
950 	/*
951 	 * No point in finding a key and decrypting if the frame is neither
952 	 * addressed to us nor a multicast frame.
953 	 */
954 	if (!(status->rx_flags & IEEE80211_RX_RA_MATCH))
955 		return RX_CONTINUE;
956 
957 	/* start without a key */
958 	rx->key = NULL;
959 
960 	if (rx->sta)
961 		sta_ptk = rcu_dereference(rx->sta->ptk);
962 
963 	fc = hdr->frame_control;
964 
965 	if (!ieee80211_has_protected(fc))
966 		mmie_keyidx = ieee80211_get_mmie_keyidx(rx->skb);
967 
968 	if (!is_multicast_ether_addr(hdr->addr1) && sta_ptk) {
969 		rx->key = sta_ptk;
970 		if ((status->flag & RX_FLAG_DECRYPTED) &&
971 		    (status->flag & RX_FLAG_IV_STRIPPED))
972 			return RX_CONTINUE;
973 		/* Skip decryption if the frame is not protected. */
974 		if (!ieee80211_has_protected(fc))
975 			return RX_CONTINUE;
976 	} else if (mmie_keyidx >= 0) {
977 		/* Broadcast/multicast robust management frame / BIP */
978 		if ((status->flag & RX_FLAG_DECRYPTED) &&
979 		    (status->flag & RX_FLAG_IV_STRIPPED))
980 			return RX_CONTINUE;
981 
982 		if (mmie_keyidx < NUM_DEFAULT_KEYS ||
983 		    mmie_keyidx >= NUM_DEFAULT_KEYS + NUM_DEFAULT_MGMT_KEYS)
984 			return RX_DROP_MONITOR; /* unexpected BIP keyidx */
985 		if (rx->sta)
986 			rx->key = rcu_dereference(rx->sta->gtk[mmie_keyidx]);
987 		if (!rx->key)
988 			rx->key = rcu_dereference(rx->sdata->keys[mmie_keyidx]);
989 	} else if (!ieee80211_has_protected(fc)) {
990 		/*
991 		 * The frame was not protected, so skip decryption. However, we
992 		 * need to set rx->key if there is a key that could have been
993 		 * used so that the frame may be dropped if encryption would
994 		 * have been expected.
995 		 */
996 		struct ieee80211_key *key = NULL;
997 		struct ieee80211_sub_if_data *sdata = rx->sdata;
998 		int i;
999 
1000 		if (ieee80211_is_mgmt(fc) &&
1001 		    is_multicast_ether_addr(hdr->addr1) &&
1002 		    (key = rcu_dereference(rx->sdata->default_mgmt_key)))
1003 			rx->key = key;
1004 		else {
1005 			if (rx->sta) {
1006 				for (i = 0; i < NUM_DEFAULT_KEYS; i++) {
1007 					key = rcu_dereference(rx->sta->gtk[i]);
1008 					if (key)
1009 						break;
1010 				}
1011 			}
1012 			if (!key) {
1013 				for (i = 0; i < NUM_DEFAULT_KEYS; i++) {
1014 					key = rcu_dereference(sdata->keys[i]);
1015 					if (key)
1016 						break;
1017 				}
1018 			}
1019 			if (key)
1020 				rx->key = key;
1021 		}
1022 		return RX_CONTINUE;
1023 	} else {
1024 		u8 keyid;
1025 		/*
1026 		 * The device doesn't give us the IV so we won't be
1027 		 * able to look up the key. That's ok though, we
1028 		 * don't need to decrypt the frame, we just won't
1029 		 * be able to keep statistics accurate.
1030 		 * Except for key threshold notifications, should
1031 		 * we somehow allow the driver to tell us which key
1032 		 * the hardware used if this flag is set?
1033 		 */
1034 		if ((status->flag & RX_FLAG_DECRYPTED) &&
1035 		    (status->flag & RX_FLAG_IV_STRIPPED))
1036 			return RX_CONTINUE;
1037 
1038 		hdrlen = ieee80211_hdrlen(fc);
1039 
1040 		if (rx->skb->len < 8 + hdrlen)
1041 			return RX_DROP_UNUSABLE; /* TODO: count this? */
1042 
1043 		/*
1044 		 * no need to call ieee80211_wep_get_keyidx,
1045 		 * it verifies a bunch of things we've done already
1046 		 */
1047 		skb_copy_bits(rx->skb, hdrlen + 3, &keyid, 1);
1048 		keyidx = keyid >> 6;
1049 
1050 		/* check per-station GTK first, if multicast packet */
1051 		if (is_multicast_ether_addr(hdr->addr1) && rx->sta)
1052 			rx->key = rcu_dereference(rx->sta->gtk[keyidx]);
1053 
1054 		/* if not found, try default key */
1055 		if (!rx->key) {
1056 			rx->key = rcu_dereference(rx->sdata->keys[keyidx]);
1057 
1058 			/*
1059 			 * RSNA-protected unicast frames should always be
1060 			 * sent with pairwise or station-to-station keys,
1061 			 * but for WEP we allow using a key index as well.
1062 			 */
1063 			if (rx->key &&
1064 			    rx->key->conf.cipher != WLAN_CIPHER_SUITE_WEP40 &&
1065 			    rx->key->conf.cipher != WLAN_CIPHER_SUITE_WEP104 &&
1066 			    !is_multicast_ether_addr(hdr->addr1))
1067 				rx->key = NULL;
1068 		}
1069 	}
1070 
1071 	if (rx->key) {
1072 		if (unlikely(rx->key->flags & KEY_FLAG_TAINTED))
1073 			return RX_DROP_MONITOR;
1074 
1075 		rx->key->tx_rx_count++;
1076 		/* TODO: add threshold stuff again */
1077 	} else {
1078 		return RX_DROP_MONITOR;
1079 	}
1080 
1081 	switch (rx->key->conf.cipher) {
1082 	case WLAN_CIPHER_SUITE_WEP40:
1083 	case WLAN_CIPHER_SUITE_WEP104:
1084 		result = ieee80211_crypto_wep_decrypt(rx);
1085 		break;
1086 	case WLAN_CIPHER_SUITE_TKIP:
1087 		result = ieee80211_crypto_tkip_decrypt(rx);
1088 		break;
1089 	case WLAN_CIPHER_SUITE_CCMP:
1090 		result = ieee80211_crypto_ccmp_decrypt(rx);
1091 		break;
1092 	case WLAN_CIPHER_SUITE_AES_CMAC:
1093 		result = ieee80211_crypto_aes_cmac_decrypt(rx);
1094 		break;
1095 	default:
1096 		/*
1097 		 * We can reach here only with HW-only algorithms
1098 		 * but why didn't it decrypt the frame?!
1099 		 */
1100 		return RX_DROP_UNUSABLE;
1101 	}
1102 
1103 	/* the hdr variable is invalid after the decrypt handlers */
1104 
1105 	/* either the frame has been decrypted or will be dropped */
1106 	status->flag |= RX_FLAG_DECRYPTED;
1107 
1108 	return result;
1109 }
1110 
1111 static ieee80211_rx_result debug_noinline
1112 ieee80211_rx_h_check_more_data(struct ieee80211_rx_data *rx)
1113 {
1114 	struct ieee80211_local *local;
1115 	struct ieee80211_hdr *hdr;
1116 	struct sk_buff *skb;
1117 
1118 	local = rx->local;
1119 	skb = rx->skb;
1120 	hdr = (struct ieee80211_hdr *) skb->data;
1121 
1122 	if (!local->pspolling)
1123 		return RX_CONTINUE;
1124 
1125 	if (!ieee80211_has_fromds(hdr->frame_control))
1126 		/* this is not from AP */
1127 		return RX_CONTINUE;
1128 
1129 	if (!ieee80211_is_data(hdr->frame_control))
1130 		return RX_CONTINUE;
1131 
1132 	if (!ieee80211_has_moredata(hdr->frame_control)) {
1133 		/* AP has no more frames buffered for us */
1134 		local->pspolling = false;
1135 		return RX_CONTINUE;
1136 	}
1137 
1138 	/* more data bit is set, let's request a new frame from the AP */
1139 	ieee80211_send_pspoll(local, rx->sdata);
1140 
1141 	return RX_CONTINUE;
1142 }
1143 
1144 static void ap_sta_ps_start(struct sta_info *sta)
1145 {
1146 	struct ieee80211_sub_if_data *sdata = sta->sdata;
1147 	struct ieee80211_local *local = sdata->local;
1148 
1149 	atomic_inc(&sdata->bss->num_sta_ps);
1150 	set_sta_flag(sta, WLAN_STA_PS_STA);
1151 	if (!(local->hw.flags & IEEE80211_HW_AP_LINK_PS))
1152 		drv_sta_notify(local, sdata, STA_NOTIFY_SLEEP, &sta->sta);
1153 	ps_dbg(sdata, "STA %pM aid %d enters power save mode\n",
1154 	       sta->sta.addr, sta->sta.aid);
1155 }
1156 
1157 static void ap_sta_ps_end(struct sta_info *sta)
1158 {
1159 	ps_dbg(sta->sdata, "STA %pM aid %d exits power save mode\n",
1160 	       sta->sta.addr, sta->sta.aid);
1161 
1162 	if (test_sta_flag(sta, WLAN_STA_PS_DRIVER)) {
1163 		ps_dbg(sta->sdata, "STA %pM aid %d driver-ps-blocked\n",
1164 		       sta->sta.addr, sta->sta.aid);
1165 		return;
1166 	}
1167 
1168 	ieee80211_sta_ps_deliver_wakeup(sta);
1169 }
1170 
1171 int ieee80211_sta_ps_transition(struct ieee80211_sta *sta, bool start)
1172 {
1173 	struct sta_info *sta_inf = container_of(sta, struct sta_info, sta);
1174 	bool in_ps;
1175 
1176 	WARN_ON(!(sta_inf->local->hw.flags & IEEE80211_HW_AP_LINK_PS));
1177 
1178 	/* Don't let the same PS state be set twice */
1179 	in_ps = test_sta_flag(sta_inf, WLAN_STA_PS_STA);
1180 	if ((start && in_ps) || (!start && !in_ps))
1181 		return -EINVAL;
1182 
1183 	if (start)
1184 		ap_sta_ps_start(sta_inf);
1185 	else
1186 		ap_sta_ps_end(sta_inf);
1187 
1188 	return 0;
1189 }
1190 EXPORT_SYMBOL(ieee80211_sta_ps_transition);
1191 
1192 static ieee80211_rx_result debug_noinline
1193 ieee80211_rx_h_uapsd_and_pspoll(struct ieee80211_rx_data *rx)
1194 {
1195 	struct ieee80211_sub_if_data *sdata = rx->sdata;
1196 	struct ieee80211_hdr *hdr = (void *)rx->skb->data;
1197 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
1198 	int tid, ac;
1199 
1200 	if (!rx->sta || !(status->rx_flags & IEEE80211_RX_RA_MATCH))
1201 		return RX_CONTINUE;
1202 
1203 	if (sdata->vif.type != NL80211_IFTYPE_AP &&
1204 	    sdata->vif.type != NL80211_IFTYPE_AP_VLAN)
1205 		return RX_CONTINUE;
1206 
1207 	/*
1208 	 * The device handles station powersave, so don't do anything about
1209 	 * uAPSD and PS-Poll frames (the latter shouldn't even come up from
1210 	 * it to mac80211 since they're handled.)
1211 	 */
1212 	if (sdata->local->hw.flags & IEEE80211_HW_AP_LINK_PS)
1213 		return RX_CONTINUE;
1214 
1215 	/*
1216 	 * Don't do anything if the station isn't already asleep. In
1217 	 * the uAPSD case, the station will probably be marked asleep,
1218 	 * in the PS-Poll case the station must be confused ...
1219 	 */
1220 	if (!test_sta_flag(rx->sta, WLAN_STA_PS_STA))
1221 		return RX_CONTINUE;
1222 
1223 	if (unlikely(ieee80211_is_pspoll(hdr->frame_control))) {
1224 		if (!test_sta_flag(rx->sta, WLAN_STA_SP)) {
1225 			if (!test_sta_flag(rx->sta, WLAN_STA_PS_DRIVER))
1226 				ieee80211_sta_ps_deliver_poll_response(rx->sta);
1227 			else
1228 				set_sta_flag(rx->sta, WLAN_STA_PSPOLL);
1229 		}
1230 
1231 		/* Free PS Poll skb here instead of returning RX_DROP that would
1232 		 * count as an dropped frame. */
1233 		dev_kfree_skb(rx->skb);
1234 
1235 		return RX_QUEUED;
1236 	} else if (!ieee80211_has_morefrags(hdr->frame_control) &&
1237 		   !(status->rx_flags & IEEE80211_RX_DEFERRED_RELEASE) &&
1238 		   ieee80211_has_pm(hdr->frame_control) &&
1239 		   (ieee80211_is_data_qos(hdr->frame_control) ||
1240 		    ieee80211_is_qos_nullfunc(hdr->frame_control))) {
1241 		tid = *ieee80211_get_qos_ctl(hdr) & IEEE80211_QOS_CTL_TID_MASK;
1242 		ac = ieee802_1d_to_ac[tid & 7];
1243 
1244 		/*
1245 		 * If this AC is not trigger-enabled do nothing.
1246 		 *
1247 		 * NB: This could/should check a separate bitmap of trigger-
1248 		 * enabled queues, but for now we only implement uAPSD w/o
1249 		 * TSPEC changes to the ACs, so they're always the same.
1250 		 */
1251 		if (!(rx->sta->sta.uapsd_queues & BIT(ac)))
1252 			return RX_CONTINUE;
1253 
1254 		/* if we are in a service period, do nothing */
1255 		if (test_sta_flag(rx->sta, WLAN_STA_SP))
1256 			return RX_CONTINUE;
1257 
1258 		if (!test_sta_flag(rx->sta, WLAN_STA_PS_DRIVER))
1259 			ieee80211_sta_ps_deliver_uapsd(rx->sta);
1260 		else
1261 			set_sta_flag(rx->sta, WLAN_STA_UAPSD);
1262 	}
1263 
1264 	return RX_CONTINUE;
1265 }
1266 
1267 static ieee80211_rx_result debug_noinline
1268 ieee80211_rx_h_sta_process(struct ieee80211_rx_data *rx)
1269 {
1270 	struct sta_info *sta = rx->sta;
1271 	struct sk_buff *skb = rx->skb;
1272 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
1273 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
1274 
1275 	if (!sta)
1276 		return RX_CONTINUE;
1277 
1278 	/*
1279 	 * Update last_rx only for IBSS packets which are for the current
1280 	 * BSSID to avoid keeping the current IBSS network alive in cases
1281 	 * where other STAs start using different BSSID.
1282 	 */
1283 	if (rx->sdata->vif.type == NL80211_IFTYPE_ADHOC) {
1284 		u8 *bssid = ieee80211_get_bssid(hdr, rx->skb->len,
1285 						NL80211_IFTYPE_ADHOC);
1286 		if (ether_addr_equal(bssid, rx->sdata->u.ibss.bssid)) {
1287 			sta->last_rx = jiffies;
1288 			if (ieee80211_is_data(hdr->frame_control)) {
1289 				sta->last_rx_rate_idx = status->rate_idx;
1290 				sta->last_rx_rate_flag = status->flag;
1291 			}
1292 		}
1293 	} else if (!is_multicast_ether_addr(hdr->addr1)) {
1294 		/*
1295 		 * Mesh beacons will update last_rx when if they are found to
1296 		 * match the current local configuration when processed.
1297 		 */
1298 		sta->last_rx = jiffies;
1299 		if (ieee80211_is_data(hdr->frame_control)) {
1300 			sta->last_rx_rate_idx = status->rate_idx;
1301 			sta->last_rx_rate_flag = status->flag;
1302 		}
1303 	}
1304 
1305 	if (!(status->rx_flags & IEEE80211_RX_RA_MATCH))
1306 		return RX_CONTINUE;
1307 
1308 	if (rx->sdata->vif.type == NL80211_IFTYPE_STATION)
1309 		ieee80211_sta_rx_notify(rx->sdata, hdr);
1310 
1311 	sta->rx_fragments++;
1312 	sta->rx_bytes += rx->skb->len;
1313 	if (!(status->flag & RX_FLAG_NO_SIGNAL_VAL)) {
1314 		sta->last_signal = status->signal;
1315 		ewma_add(&sta->avg_signal, -status->signal);
1316 	}
1317 
1318 	/*
1319 	 * Change STA power saving mode only at the end of a frame
1320 	 * exchange sequence.
1321 	 */
1322 	if (!(sta->local->hw.flags & IEEE80211_HW_AP_LINK_PS) &&
1323 	    !ieee80211_has_morefrags(hdr->frame_control) &&
1324 	    !(status->rx_flags & IEEE80211_RX_DEFERRED_RELEASE) &&
1325 	    (rx->sdata->vif.type == NL80211_IFTYPE_AP ||
1326 	     rx->sdata->vif.type == NL80211_IFTYPE_AP_VLAN)) {
1327 		if (test_sta_flag(sta, WLAN_STA_PS_STA)) {
1328 			/*
1329 			 * Ignore doze->wake transitions that are
1330 			 * indicated by non-data frames, the standard
1331 			 * is unclear here, but for example going to
1332 			 * PS mode and then scanning would cause a
1333 			 * doze->wake transition for the probe request,
1334 			 * and that is clearly undesirable.
1335 			 */
1336 			if (ieee80211_is_data(hdr->frame_control) &&
1337 			    !ieee80211_has_pm(hdr->frame_control))
1338 				ap_sta_ps_end(sta);
1339 		} else {
1340 			if (ieee80211_has_pm(hdr->frame_control))
1341 				ap_sta_ps_start(sta);
1342 		}
1343 	}
1344 
1345 	/*
1346 	 * Drop (qos-)data::nullfunc frames silently, since they
1347 	 * are used only to control station power saving mode.
1348 	 */
1349 	if (ieee80211_is_nullfunc(hdr->frame_control) ||
1350 	    ieee80211_is_qos_nullfunc(hdr->frame_control)) {
1351 		I802_DEBUG_INC(rx->local->rx_handlers_drop_nullfunc);
1352 
1353 		/*
1354 		 * If we receive a 4-addr nullfunc frame from a STA
1355 		 * that was not moved to a 4-addr STA vlan yet send
1356 		 * the event to userspace and for older hostapd drop
1357 		 * the frame to the monitor interface.
1358 		 */
1359 		if (ieee80211_has_a4(hdr->frame_control) &&
1360 		    (rx->sdata->vif.type == NL80211_IFTYPE_AP ||
1361 		     (rx->sdata->vif.type == NL80211_IFTYPE_AP_VLAN &&
1362 		      !rx->sdata->u.vlan.sta))) {
1363 			if (!test_and_set_sta_flag(sta, WLAN_STA_4ADDR_EVENT))
1364 				cfg80211_rx_unexpected_4addr_frame(
1365 					rx->sdata->dev, sta->sta.addr,
1366 					GFP_ATOMIC);
1367 			return RX_DROP_MONITOR;
1368 		}
1369 		/*
1370 		 * Update counter and free packet here to avoid
1371 		 * counting this as a dropped packed.
1372 		 */
1373 		sta->rx_packets++;
1374 		dev_kfree_skb(rx->skb);
1375 		return RX_QUEUED;
1376 	}
1377 
1378 	return RX_CONTINUE;
1379 } /* ieee80211_rx_h_sta_process */
1380 
1381 static inline struct ieee80211_fragment_entry *
1382 ieee80211_reassemble_add(struct ieee80211_sub_if_data *sdata,
1383 			 unsigned int frag, unsigned int seq, int rx_queue,
1384 			 struct sk_buff **skb)
1385 {
1386 	struct ieee80211_fragment_entry *entry;
1387 	int idx;
1388 
1389 	idx = sdata->fragment_next;
1390 	entry = &sdata->fragments[sdata->fragment_next++];
1391 	if (sdata->fragment_next >= IEEE80211_FRAGMENT_MAX)
1392 		sdata->fragment_next = 0;
1393 
1394 	if (!skb_queue_empty(&entry->skb_list))
1395 		__skb_queue_purge(&entry->skb_list);
1396 
1397 	__skb_queue_tail(&entry->skb_list, *skb); /* no need for locking */
1398 	*skb = NULL;
1399 	entry->first_frag_time = jiffies;
1400 	entry->seq = seq;
1401 	entry->rx_queue = rx_queue;
1402 	entry->last_frag = frag;
1403 	entry->ccmp = 0;
1404 	entry->extra_len = 0;
1405 
1406 	return entry;
1407 }
1408 
1409 static inline struct ieee80211_fragment_entry *
1410 ieee80211_reassemble_find(struct ieee80211_sub_if_data *sdata,
1411 			  unsigned int frag, unsigned int seq,
1412 			  int rx_queue, struct ieee80211_hdr *hdr)
1413 {
1414 	struct ieee80211_fragment_entry *entry;
1415 	int i, idx;
1416 
1417 	idx = sdata->fragment_next;
1418 	for (i = 0; i < IEEE80211_FRAGMENT_MAX; i++) {
1419 		struct ieee80211_hdr *f_hdr;
1420 
1421 		idx--;
1422 		if (idx < 0)
1423 			idx = IEEE80211_FRAGMENT_MAX - 1;
1424 
1425 		entry = &sdata->fragments[idx];
1426 		if (skb_queue_empty(&entry->skb_list) || entry->seq != seq ||
1427 		    entry->rx_queue != rx_queue ||
1428 		    entry->last_frag + 1 != frag)
1429 			continue;
1430 
1431 		f_hdr = (struct ieee80211_hdr *)entry->skb_list.next->data;
1432 
1433 		/*
1434 		 * Check ftype and addresses are equal, else check next fragment
1435 		 */
1436 		if (((hdr->frame_control ^ f_hdr->frame_control) &
1437 		     cpu_to_le16(IEEE80211_FCTL_FTYPE)) ||
1438 		    !ether_addr_equal(hdr->addr1, f_hdr->addr1) ||
1439 		    !ether_addr_equal(hdr->addr2, f_hdr->addr2))
1440 			continue;
1441 
1442 		if (time_after(jiffies, entry->first_frag_time + 2 * HZ)) {
1443 			__skb_queue_purge(&entry->skb_list);
1444 			continue;
1445 		}
1446 		return entry;
1447 	}
1448 
1449 	return NULL;
1450 }
1451 
1452 static ieee80211_rx_result debug_noinline
1453 ieee80211_rx_h_defragment(struct ieee80211_rx_data *rx)
1454 {
1455 	struct ieee80211_hdr *hdr;
1456 	u16 sc;
1457 	__le16 fc;
1458 	unsigned int frag, seq;
1459 	struct ieee80211_fragment_entry *entry;
1460 	struct sk_buff *skb;
1461 	struct ieee80211_rx_status *status;
1462 
1463 	hdr = (struct ieee80211_hdr *)rx->skb->data;
1464 	fc = hdr->frame_control;
1465 	sc = le16_to_cpu(hdr->seq_ctrl);
1466 	frag = sc & IEEE80211_SCTL_FRAG;
1467 
1468 	if (likely((!ieee80211_has_morefrags(fc) && frag == 0) ||
1469 		   (rx->skb)->len < 24 ||
1470 		   is_multicast_ether_addr(hdr->addr1))) {
1471 		/* not fragmented */
1472 		goto out;
1473 	}
1474 	I802_DEBUG_INC(rx->local->rx_handlers_fragments);
1475 
1476 	if (skb_linearize(rx->skb))
1477 		return RX_DROP_UNUSABLE;
1478 
1479 	/*
1480 	 *  skb_linearize() might change the skb->data and
1481 	 *  previously cached variables (in this case, hdr) need to
1482 	 *  be refreshed with the new data.
1483 	 */
1484 	hdr = (struct ieee80211_hdr *)rx->skb->data;
1485 	seq = (sc & IEEE80211_SCTL_SEQ) >> 4;
1486 
1487 	if (frag == 0) {
1488 		/* This is the first fragment of a new frame. */
1489 		entry = ieee80211_reassemble_add(rx->sdata, frag, seq,
1490 						 rx->seqno_idx, &(rx->skb));
1491 		if (rx->key && rx->key->conf.cipher == WLAN_CIPHER_SUITE_CCMP &&
1492 		    ieee80211_has_protected(fc)) {
1493 			int queue = rx->security_idx;
1494 			/* Store CCMP PN so that we can verify that the next
1495 			 * fragment has a sequential PN value. */
1496 			entry->ccmp = 1;
1497 			memcpy(entry->last_pn,
1498 			       rx->key->u.ccmp.rx_pn[queue],
1499 			       CCMP_PN_LEN);
1500 		}
1501 		return RX_QUEUED;
1502 	}
1503 
1504 	/* This is a fragment for a frame that should already be pending in
1505 	 * fragment cache. Add this fragment to the end of the pending entry.
1506 	 */
1507 	entry = ieee80211_reassemble_find(rx->sdata, frag, seq,
1508 					  rx->seqno_idx, hdr);
1509 	if (!entry) {
1510 		I802_DEBUG_INC(rx->local->rx_handlers_drop_defrag);
1511 		return RX_DROP_MONITOR;
1512 	}
1513 
1514 	/* Verify that MPDUs within one MSDU have sequential PN values.
1515 	 * (IEEE 802.11i, 8.3.3.4.5) */
1516 	if (entry->ccmp) {
1517 		int i;
1518 		u8 pn[CCMP_PN_LEN], *rpn;
1519 		int queue;
1520 		if (!rx->key || rx->key->conf.cipher != WLAN_CIPHER_SUITE_CCMP)
1521 			return RX_DROP_UNUSABLE;
1522 		memcpy(pn, entry->last_pn, CCMP_PN_LEN);
1523 		for (i = CCMP_PN_LEN - 1; i >= 0; i--) {
1524 			pn[i]++;
1525 			if (pn[i])
1526 				break;
1527 		}
1528 		queue = rx->security_idx;
1529 		rpn = rx->key->u.ccmp.rx_pn[queue];
1530 		if (memcmp(pn, rpn, CCMP_PN_LEN))
1531 			return RX_DROP_UNUSABLE;
1532 		memcpy(entry->last_pn, pn, CCMP_PN_LEN);
1533 	}
1534 
1535 	skb_pull(rx->skb, ieee80211_hdrlen(fc));
1536 	__skb_queue_tail(&entry->skb_list, rx->skb);
1537 	entry->last_frag = frag;
1538 	entry->extra_len += rx->skb->len;
1539 	if (ieee80211_has_morefrags(fc)) {
1540 		rx->skb = NULL;
1541 		return RX_QUEUED;
1542 	}
1543 
1544 	rx->skb = __skb_dequeue(&entry->skb_list);
1545 	if (skb_tailroom(rx->skb) < entry->extra_len) {
1546 		I802_DEBUG_INC(rx->local->rx_expand_skb_head2);
1547 		if (unlikely(pskb_expand_head(rx->skb, 0, entry->extra_len,
1548 					      GFP_ATOMIC))) {
1549 			I802_DEBUG_INC(rx->local->rx_handlers_drop_defrag);
1550 			__skb_queue_purge(&entry->skb_list);
1551 			return RX_DROP_UNUSABLE;
1552 		}
1553 	}
1554 	while ((skb = __skb_dequeue(&entry->skb_list))) {
1555 		memcpy(skb_put(rx->skb, skb->len), skb->data, skb->len);
1556 		dev_kfree_skb(skb);
1557 	}
1558 
1559 	/* Complete frame has been reassembled - process it now */
1560 	status = IEEE80211_SKB_RXCB(rx->skb);
1561 	status->rx_flags |= IEEE80211_RX_FRAGMENTED;
1562 
1563  out:
1564 	if (rx->sta)
1565 		rx->sta->rx_packets++;
1566 	if (is_multicast_ether_addr(hdr->addr1))
1567 		rx->local->dot11MulticastReceivedFrameCount++;
1568 	else
1569 		ieee80211_led_rx(rx->local);
1570 	return RX_CONTINUE;
1571 }
1572 
1573 static int
1574 ieee80211_802_1x_port_control(struct ieee80211_rx_data *rx)
1575 {
1576 	if (unlikely(!rx->sta ||
1577 	    !test_sta_flag(rx->sta, WLAN_STA_AUTHORIZED)))
1578 		return -EACCES;
1579 
1580 	return 0;
1581 }
1582 
1583 static int
1584 ieee80211_drop_unencrypted(struct ieee80211_rx_data *rx, __le16 fc)
1585 {
1586 	struct sk_buff *skb = rx->skb;
1587 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
1588 
1589 	/*
1590 	 * Pass through unencrypted frames if the hardware has
1591 	 * decrypted them already.
1592 	 */
1593 	if (status->flag & RX_FLAG_DECRYPTED)
1594 		return 0;
1595 
1596 	/* Drop unencrypted frames if key is set. */
1597 	if (unlikely(!ieee80211_has_protected(fc) &&
1598 		     !ieee80211_is_nullfunc(fc) &&
1599 		     ieee80211_is_data(fc) &&
1600 		     (rx->key || rx->sdata->drop_unencrypted)))
1601 		return -EACCES;
1602 
1603 	return 0;
1604 }
1605 
1606 static int
1607 ieee80211_drop_unencrypted_mgmt(struct ieee80211_rx_data *rx)
1608 {
1609 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
1610 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
1611 	__le16 fc = hdr->frame_control;
1612 
1613 	/*
1614 	 * Pass through unencrypted frames if the hardware has
1615 	 * decrypted them already.
1616 	 */
1617 	if (status->flag & RX_FLAG_DECRYPTED)
1618 		return 0;
1619 
1620 	if (rx->sta && test_sta_flag(rx->sta, WLAN_STA_MFP)) {
1621 		if (unlikely(!ieee80211_has_protected(fc) &&
1622 			     ieee80211_is_unicast_robust_mgmt_frame(rx->skb) &&
1623 			     rx->key)) {
1624 			if (ieee80211_is_deauth(fc))
1625 				cfg80211_send_unprot_deauth(rx->sdata->dev,
1626 							    rx->skb->data,
1627 							    rx->skb->len);
1628 			else if (ieee80211_is_disassoc(fc))
1629 				cfg80211_send_unprot_disassoc(rx->sdata->dev,
1630 							      rx->skb->data,
1631 							      rx->skb->len);
1632 			return -EACCES;
1633 		}
1634 		/* BIP does not use Protected field, so need to check MMIE */
1635 		if (unlikely(ieee80211_is_multicast_robust_mgmt_frame(rx->skb) &&
1636 			     ieee80211_get_mmie_keyidx(rx->skb) < 0)) {
1637 			if (ieee80211_is_deauth(fc))
1638 				cfg80211_send_unprot_deauth(rx->sdata->dev,
1639 							    rx->skb->data,
1640 							    rx->skb->len);
1641 			else if (ieee80211_is_disassoc(fc))
1642 				cfg80211_send_unprot_disassoc(rx->sdata->dev,
1643 							      rx->skb->data,
1644 							      rx->skb->len);
1645 			return -EACCES;
1646 		}
1647 		/*
1648 		 * When using MFP, Action frames are not allowed prior to
1649 		 * having configured keys.
1650 		 */
1651 		if (unlikely(ieee80211_is_action(fc) && !rx->key &&
1652 			     ieee80211_is_robust_mgmt_frame(
1653 				     (struct ieee80211_hdr *) rx->skb->data)))
1654 			return -EACCES;
1655 	}
1656 
1657 	return 0;
1658 }
1659 
1660 static int
1661 __ieee80211_data_to_8023(struct ieee80211_rx_data *rx, bool *port_control)
1662 {
1663 	struct ieee80211_sub_if_data *sdata = rx->sdata;
1664 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
1665 	bool check_port_control = false;
1666 	struct ethhdr *ehdr;
1667 	int ret;
1668 
1669 	*port_control = false;
1670 	if (ieee80211_has_a4(hdr->frame_control) &&
1671 	    sdata->vif.type == NL80211_IFTYPE_AP_VLAN && !sdata->u.vlan.sta)
1672 		return -1;
1673 
1674 	if (sdata->vif.type == NL80211_IFTYPE_STATION &&
1675 	    !!sdata->u.mgd.use_4addr != !!ieee80211_has_a4(hdr->frame_control)) {
1676 
1677 		if (!sdata->u.mgd.use_4addr)
1678 			return -1;
1679 		else
1680 			check_port_control = true;
1681 	}
1682 
1683 	if (is_multicast_ether_addr(hdr->addr1) &&
1684 	    sdata->vif.type == NL80211_IFTYPE_AP_VLAN && sdata->u.vlan.sta)
1685 		return -1;
1686 
1687 	ret = ieee80211_data_to_8023(rx->skb, sdata->vif.addr, sdata->vif.type);
1688 	if (ret < 0)
1689 		return ret;
1690 
1691 	ehdr = (struct ethhdr *) rx->skb->data;
1692 	if (ehdr->h_proto == rx->sdata->control_port_protocol)
1693 		*port_control = true;
1694 	else if (check_port_control)
1695 		return -1;
1696 
1697 	return 0;
1698 }
1699 
1700 /*
1701  * requires that rx->skb is a frame with ethernet header
1702  */
1703 static bool ieee80211_frame_allowed(struct ieee80211_rx_data *rx, __le16 fc)
1704 {
1705 	static const u8 pae_group_addr[ETH_ALEN] __aligned(2)
1706 		= { 0x01, 0x80, 0xC2, 0x00, 0x00, 0x03 };
1707 	struct ethhdr *ehdr = (struct ethhdr *) rx->skb->data;
1708 
1709 	/*
1710 	 * Allow EAPOL frames to us/the PAE group address regardless
1711 	 * of whether the frame was encrypted or not.
1712 	 */
1713 	if (ehdr->h_proto == rx->sdata->control_port_protocol &&
1714 	    (ether_addr_equal(ehdr->h_dest, rx->sdata->vif.addr) ||
1715 	     ether_addr_equal(ehdr->h_dest, pae_group_addr)))
1716 		return true;
1717 
1718 	if (ieee80211_802_1x_port_control(rx) ||
1719 	    ieee80211_drop_unencrypted(rx, fc))
1720 		return false;
1721 
1722 	return true;
1723 }
1724 
1725 /*
1726  * requires that rx->skb is a frame with ethernet header
1727  */
1728 static void
1729 ieee80211_deliver_skb(struct ieee80211_rx_data *rx)
1730 {
1731 	struct ieee80211_sub_if_data *sdata = rx->sdata;
1732 	struct net_device *dev = sdata->dev;
1733 	struct sk_buff *skb, *xmit_skb;
1734 	struct ethhdr *ehdr = (struct ethhdr *) rx->skb->data;
1735 	struct sta_info *dsta;
1736 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
1737 
1738 	skb = rx->skb;
1739 	xmit_skb = NULL;
1740 
1741 	if ((sdata->vif.type == NL80211_IFTYPE_AP ||
1742 	     sdata->vif.type == NL80211_IFTYPE_AP_VLAN) &&
1743 	    !(sdata->flags & IEEE80211_SDATA_DONT_BRIDGE_PACKETS) &&
1744 	    (status->rx_flags & IEEE80211_RX_RA_MATCH) &&
1745 	    (sdata->vif.type != NL80211_IFTYPE_AP_VLAN || !sdata->u.vlan.sta)) {
1746 		if (is_multicast_ether_addr(ehdr->h_dest)) {
1747 			/*
1748 			 * send multicast frames both to higher layers in
1749 			 * local net stack and back to the wireless medium
1750 			 */
1751 			xmit_skb = skb_copy(skb, GFP_ATOMIC);
1752 			if (!xmit_skb)
1753 				net_info_ratelimited("%s: failed to clone multicast frame\n",
1754 						    dev->name);
1755 		} else {
1756 			dsta = sta_info_get(sdata, skb->data);
1757 			if (dsta) {
1758 				/*
1759 				 * The destination station is associated to
1760 				 * this AP (in this VLAN), so send the frame
1761 				 * directly to it and do not pass it to local
1762 				 * net stack.
1763 				 */
1764 				xmit_skb = skb;
1765 				skb = NULL;
1766 			}
1767 		}
1768 	}
1769 
1770 	if (skb) {
1771 		int align __maybe_unused;
1772 
1773 #ifndef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
1774 		/*
1775 		 * 'align' will only take the values 0 or 2 here
1776 		 * since all frames are required to be aligned
1777 		 * to 2-byte boundaries when being passed to
1778 		 * mac80211. That also explains the __skb_push()
1779 		 * below.
1780 		 */
1781 		align = ((unsigned long)(skb->data + sizeof(struct ethhdr))) & 3;
1782 		if (align) {
1783 			if (WARN_ON(skb_headroom(skb) < 3)) {
1784 				dev_kfree_skb(skb);
1785 				skb = NULL;
1786 			} else {
1787 				u8 *data = skb->data;
1788 				size_t len = skb_headlen(skb);
1789 				skb->data -= align;
1790 				memmove(skb->data, data, len);
1791 				skb_set_tail_pointer(skb, len);
1792 			}
1793 		}
1794 #endif
1795 
1796 		if (skb) {
1797 			/* deliver to local stack */
1798 			skb->protocol = eth_type_trans(skb, dev);
1799 			memset(skb->cb, 0, sizeof(skb->cb));
1800 			netif_receive_skb(skb);
1801 		}
1802 	}
1803 
1804 	if (xmit_skb) {
1805 		/*
1806 		 * Send to wireless media and increase priority by 256 to
1807 		 * keep the received priority instead of reclassifying
1808 		 * the frame (see cfg80211_classify8021d).
1809 		 */
1810 		xmit_skb->priority += 256;
1811 		xmit_skb->protocol = htons(ETH_P_802_3);
1812 		skb_reset_network_header(xmit_skb);
1813 		skb_reset_mac_header(xmit_skb);
1814 		dev_queue_xmit(xmit_skb);
1815 	}
1816 }
1817 
1818 static ieee80211_rx_result debug_noinline
1819 ieee80211_rx_h_amsdu(struct ieee80211_rx_data *rx)
1820 {
1821 	struct net_device *dev = rx->sdata->dev;
1822 	struct sk_buff *skb = rx->skb;
1823 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
1824 	__le16 fc = hdr->frame_control;
1825 	struct sk_buff_head frame_list;
1826 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
1827 
1828 	if (unlikely(!ieee80211_is_data(fc)))
1829 		return RX_CONTINUE;
1830 
1831 	if (unlikely(!ieee80211_is_data_present(fc)))
1832 		return RX_DROP_MONITOR;
1833 
1834 	if (!(status->rx_flags & IEEE80211_RX_AMSDU))
1835 		return RX_CONTINUE;
1836 
1837 	if (ieee80211_has_a4(hdr->frame_control) &&
1838 	    rx->sdata->vif.type == NL80211_IFTYPE_AP_VLAN &&
1839 	    !rx->sdata->u.vlan.sta)
1840 		return RX_DROP_UNUSABLE;
1841 
1842 	if (is_multicast_ether_addr(hdr->addr1) &&
1843 	    ((rx->sdata->vif.type == NL80211_IFTYPE_AP_VLAN &&
1844 	      rx->sdata->u.vlan.sta) ||
1845 	     (rx->sdata->vif.type == NL80211_IFTYPE_STATION &&
1846 	      rx->sdata->u.mgd.use_4addr)))
1847 		return RX_DROP_UNUSABLE;
1848 
1849 	skb->dev = dev;
1850 	__skb_queue_head_init(&frame_list);
1851 
1852 	if (skb_linearize(skb))
1853 		return RX_DROP_UNUSABLE;
1854 
1855 	ieee80211_amsdu_to_8023s(skb, &frame_list, dev->dev_addr,
1856 				 rx->sdata->vif.type,
1857 				 rx->local->hw.extra_tx_headroom, true);
1858 
1859 	while (!skb_queue_empty(&frame_list)) {
1860 		rx->skb = __skb_dequeue(&frame_list);
1861 
1862 		if (!ieee80211_frame_allowed(rx, fc)) {
1863 			dev_kfree_skb(rx->skb);
1864 			continue;
1865 		}
1866 		dev->stats.rx_packets++;
1867 		dev->stats.rx_bytes += rx->skb->len;
1868 
1869 		ieee80211_deliver_skb(rx);
1870 	}
1871 
1872 	return RX_QUEUED;
1873 }
1874 
1875 #ifdef CONFIG_MAC80211_MESH
1876 static ieee80211_rx_result
1877 ieee80211_rx_h_mesh_fwding(struct ieee80211_rx_data *rx)
1878 {
1879 	struct ieee80211_hdr *fwd_hdr, *hdr;
1880 	struct ieee80211_tx_info *info;
1881 	struct ieee80211s_hdr *mesh_hdr;
1882 	struct sk_buff *skb = rx->skb, *fwd_skb;
1883 	struct ieee80211_local *local = rx->local;
1884 	struct ieee80211_sub_if_data *sdata = rx->sdata;
1885 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
1886 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
1887 	__le16 reason = cpu_to_le16(WLAN_REASON_MESH_PATH_NOFORWARD);
1888 	u16 q, hdrlen;
1889 
1890 	hdr = (struct ieee80211_hdr *) skb->data;
1891 	hdrlen = ieee80211_hdrlen(hdr->frame_control);
1892 	mesh_hdr = (struct ieee80211s_hdr *) (skb->data + hdrlen);
1893 
1894 	/* frame is in RMC, don't forward */
1895 	if (ieee80211_is_data(hdr->frame_control) &&
1896 	    is_multicast_ether_addr(hdr->addr1) &&
1897 	    mesh_rmc_check(hdr->addr3, mesh_hdr, rx->sdata))
1898 		return RX_DROP_MONITOR;
1899 
1900 	if (!ieee80211_is_data(hdr->frame_control))
1901 		return RX_CONTINUE;
1902 
1903 	if (!mesh_hdr->ttl)
1904 		return RX_DROP_MONITOR;
1905 
1906 	if (mesh_hdr->flags & MESH_FLAGS_AE) {
1907 		struct mesh_path *mppath;
1908 		char *proxied_addr;
1909 		char *mpp_addr;
1910 
1911 		if (is_multicast_ether_addr(hdr->addr1)) {
1912 			mpp_addr = hdr->addr3;
1913 			proxied_addr = mesh_hdr->eaddr1;
1914 		} else {
1915 			mpp_addr = hdr->addr4;
1916 			proxied_addr = mesh_hdr->eaddr2;
1917 		}
1918 
1919 		rcu_read_lock();
1920 		mppath = mpp_path_lookup(proxied_addr, sdata);
1921 		if (!mppath) {
1922 			mpp_path_add(proxied_addr, mpp_addr, sdata);
1923 		} else {
1924 			spin_lock_bh(&mppath->state_lock);
1925 			if (!ether_addr_equal(mppath->mpp, mpp_addr))
1926 				memcpy(mppath->mpp, mpp_addr, ETH_ALEN);
1927 			spin_unlock_bh(&mppath->state_lock);
1928 		}
1929 		rcu_read_unlock();
1930 	}
1931 
1932 	/* Frame has reached destination.  Don't forward */
1933 	if (!is_multicast_ether_addr(hdr->addr1) &&
1934 	    ether_addr_equal(sdata->vif.addr, hdr->addr3))
1935 		return RX_CONTINUE;
1936 
1937 	q = ieee80211_select_queue_80211(sdata, skb, hdr);
1938 	if (ieee80211_queue_stopped(&local->hw, q)) {
1939 		IEEE80211_IFSTA_MESH_CTR_INC(ifmsh, dropped_frames_congestion);
1940 		return RX_DROP_MONITOR;
1941 	}
1942 	skb_set_queue_mapping(skb, q);
1943 
1944 	if (!(status->rx_flags & IEEE80211_RX_RA_MATCH))
1945 		goto out;
1946 
1947 	if (!--mesh_hdr->ttl) {
1948 		IEEE80211_IFSTA_MESH_CTR_INC(ifmsh, dropped_frames_ttl);
1949 		return RX_DROP_MONITOR;
1950 	}
1951 
1952 	if (!ifmsh->mshcfg.dot11MeshForwarding)
1953 		goto out;
1954 
1955 	fwd_skb = skb_copy(skb, GFP_ATOMIC);
1956 	if (!fwd_skb) {
1957 		net_info_ratelimited("%s: failed to clone mesh frame\n",
1958 				    sdata->name);
1959 		goto out;
1960 	}
1961 
1962 	fwd_hdr =  (struct ieee80211_hdr *) fwd_skb->data;
1963 	info = IEEE80211_SKB_CB(fwd_skb);
1964 	memset(info, 0, sizeof(*info));
1965 	info->flags |= IEEE80211_TX_INTFL_NEED_TXPROCESSING;
1966 	info->control.vif = &rx->sdata->vif;
1967 	info->control.jiffies = jiffies;
1968 	if (is_multicast_ether_addr(fwd_hdr->addr1)) {
1969 		IEEE80211_IFSTA_MESH_CTR_INC(ifmsh, fwded_mcast);
1970 		memcpy(fwd_hdr->addr2, sdata->vif.addr, ETH_ALEN);
1971 	} else if (!mesh_nexthop_lookup(fwd_skb, sdata)) {
1972 		IEEE80211_IFSTA_MESH_CTR_INC(ifmsh, fwded_unicast);
1973 	} else {
1974 		/* unable to resolve next hop */
1975 		mesh_path_error_tx(ifmsh->mshcfg.element_ttl, fwd_hdr->addr3,
1976 				    0, reason, fwd_hdr->addr2, sdata);
1977 		IEEE80211_IFSTA_MESH_CTR_INC(ifmsh, dropped_frames_no_route);
1978 		kfree_skb(fwd_skb);
1979 		return RX_DROP_MONITOR;
1980 	}
1981 
1982 	IEEE80211_IFSTA_MESH_CTR_INC(ifmsh, fwded_frames);
1983 	ieee80211_add_pending_skb(local, fwd_skb);
1984  out:
1985 	if (is_multicast_ether_addr(hdr->addr1) ||
1986 	    sdata->dev->flags & IFF_PROMISC)
1987 		return RX_CONTINUE;
1988 	else
1989 		return RX_DROP_MONITOR;
1990 }
1991 #endif
1992 
1993 static ieee80211_rx_result debug_noinline
1994 ieee80211_rx_h_data(struct ieee80211_rx_data *rx)
1995 {
1996 	struct ieee80211_sub_if_data *sdata = rx->sdata;
1997 	struct ieee80211_local *local = rx->local;
1998 	struct net_device *dev = sdata->dev;
1999 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
2000 	__le16 fc = hdr->frame_control;
2001 	bool port_control;
2002 	int err;
2003 
2004 	if (unlikely(!ieee80211_is_data(hdr->frame_control)))
2005 		return RX_CONTINUE;
2006 
2007 	if (unlikely(!ieee80211_is_data_present(hdr->frame_control)))
2008 		return RX_DROP_MONITOR;
2009 
2010 	/*
2011 	 * Send unexpected-4addr-frame event to hostapd. For older versions,
2012 	 * also drop the frame to cooked monitor interfaces.
2013 	 */
2014 	if (ieee80211_has_a4(hdr->frame_control) &&
2015 	    sdata->vif.type == NL80211_IFTYPE_AP) {
2016 		if (rx->sta &&
2017 		    !test_and_set_sta_flag(rx->sta, WLAN_STA_4ADDR_EVENT))
2018 			cfg80211_rx_unexpected_4addr_frame(
2019 				rx->sdata->dev, rx->sta->sta.addr, GFP_ATOMIC);
2020 		return RX_DROP_MONITOR;
2021 	}
2022 
2023 	err = __ieee80211_data_to_8023(rx, &port_control);
2024 	if (unlikely(err))
2025 		return RX_DROP_UNUSABLE;
2026 
2027 	if (!ieee80211_frame_allowed(rx, fc))
2028 		return RX_DROP_MONITOR;
2029 
2030 	if (rx->sdata->vif.type == NL80211_IFTYPE_AP_VLAN &&
2031 	    unlikely(port_control) && sdata->bss) {
2032 		sdata = container_of(sdata->bss, struct ieee80211_sub_if_data,
2033 				     u.ap);
2034 		dev = sdata->dev;
2035 		rx->sdata = sdata;
2036 	}
2037 
2038 	rx->skb->dev = dev;
2039 
2040 	dev->stats.rx_packets++;
2041 	dev->stats.rx_bytes += rx->skb->len;
2042 
2043 	if (local->ps_sdata && local->hw.conf.dynamic_ps_timeout > 0 &&
2044 	    !is_multicast_ether_addr(
2045 		    ((struct ethhdr *)rx->skb->data)->h_dest) &&
2046 	    (!local->scanning &&
2047 	     !test_bit(SDATA_STATE_OFFCHANNEL, &sdata->state))) {
2048 			mod_timer(&local->dynamic_ps_timer, jiffies +
2049 			 msecs_to_jiffies(local->hw.conf.dynamic_ps_timeout));
2050 	}
2051 
2052 	ieee80211_deliver_skb(rx);
2053 
2054 	return RX_QUEUED;
2055 }
2056 
2057 static ieee80211_rx_result debug_noinline
2058 ieee80211_rx_h_ctrl(struct ieee80211_rx_data *rx)
2059 {
2060 	struct sk_buff *skb = rx->skb;
2061 	struct ieee80211_bar *bar = (struct ieee80211_bar *)skb->data;
2062 	struct tid_ampdu_rx *tid_agg_rx;
2063 	u16 start_seq_num;
2064 	u16 tid;
2065 
2066 	if (likely(!ieee80211_is_ctl(bar->frame_control)))
2067 		return RX_CONTINUE;
2068 
2069 	if (ieee80211_is_back_req(bar->frame_control)) {
2070 		struct {
2071 			__le16 control, start_seq_num;
2072 		} __packed bar_data;
2073 
2074 		if (!rx->sta)
2075 			return RX_DROP_MONITOR;
2076 
2077 		if (skb_copy_bits(skb, offsetof(struct ieee80211_bar, control),
2078 				  &bar_data, sizeof(bar_data)))
2079 			return RX_DROP_MONITOR;
2080 
2081 		tid = le16_to_cpu(bar_data.control) >> 12;
2082 
2083 		tid_agg_rx = rcu_dereference(rx->sta->ampdu_mlme.tid_rx[tid]);
2084 		if (!tid_agg_rx)
2085 			return RX_DROP_MONITOR;
2086 
2087 		start_seq_num = le16_to_cpu(bar_data.start_seq_num) >> 4;
2088 
2089 		/* reset session timer */
2090 		if (tid_agg_rx->timeout)
2091 			mod_timer(&tid_agg_rx->session_timer,
2092 				  TU_TO_EXP_TIME(tid_agg_rx->timeout));
2093 
2094 		spin_lock(&tid_agg_rx->reorder_lock);
2095 		/* release stored frames up to start of BAR */
2096 		ieee80211_release_reorder_frames(rx->sdata, tid_agg_rx,
2097 						 start_seq_num);
2098 		spin_unlock(&tid_agg_rx->reorder_lock);
2099 
2100 		kfree_skb(skb);
2101 		return RX_QUEUED;
2102 	}
2103 
2104 	/*
2105 	 * After this point, we only want management frames,
2106 	 * so we can drop all remaining control frames to
2107 	 * cooked monitor interfaces.
2108 	 */
2109 	return RX_DROP_MONITOR;
2110 }
2111 
2112 static void ieee80211_process_sa_query_req(struct ieee80211_sub_if_data *sdata,
2113 					   struct ieee80211_mgmt *mgmt,
2114 					   size_t len)
2115 {
2116 	struct ieee80211_local *local = sdata->local;
2117 	struct sk_buff *skb;
2118 	struct ieee80211_mgmt *resp;
2119 
2120 	if (!ether_addr_equal(mgmt->da, sdata->vif.addr)) {
2121 		/* Not to own unicast address */
2122 		return;
2123 	}
2124 
2125 	if (!ether_addr_equal(mgmt->sa, sdata->u.mgd.bssid) ||
2126 	    !ether_addr_equal(mgmt->bssid, sdata->u.mgd.bssid)) {
2127 		/* Not from the current AP or not associated yet. */
2128 		return;
2129 	}
2130 
2131 	if (len < 24 + 1 + sizeof(resp->u.action.u.sa_query)) {
2132 		/* Too short SA Query request frame */
2133 		return;
2134 	}
2135 
2136 	skb = dev_alloc_skb(sizeof(*resp) + local->hw.extra_tx_headroom);
2137 	if (skb == NULL)
2138 		return;
2139 
2140 	skb_reserve(skb, local->hw.extra_tx_headroom);
2141 	resp = (struct ieee80211_mgmt *) skb_put(skb, 24);
2142 	memset(resp, 0, 24);
2143 	memcpy(resp->da, mgmt->sa, ETH_ALEN);
2144 	memcpy(resp->sa, sdata->vif.addr, ETH_ALEN);
2145 	memcpy(resp->bssid, sdata->u.mgd.bssid, ETH_ALEN);
2146 	resp->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
2147 					  IEEE80211_STYPE_ACTION);
2148 	skb_put(skb, 1 + sizeof(resp->u.action.u.sa_query));
2149 	resp->u.action.category = WLAN_CATEGORY_SA_QUERY;
2150 	resp->u.action.u.sa_query.action = WLAN_ACTION_SA_QUERY_RESPONSE;
2151 	memcpy(resp->u.action.u.sa_query.trans_id,
2152 	       mgmt->u.action.u.sa_query.trans_id,
2153 	       WLAN_SA_QUERY_TR_ID_LEN);
2154 
2155 	ieee80211_tx_skb(sdata, skb);
2156 }
2157 
2158 static ieee80211_rx_result debug_noinline
2159 ieee80211_rx_h_mgmt_check(struct ieee80211_rx_data *rx)
2160 {
2161 	struct ieee80211_mgmt *mgmt = (struct ieee80211_mgmt *) rx->skb->data;
2162 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
2163 
2164 	/*
2165 	 * From here on, look only at management frames.
2166 	 * Data and control frames are already handled,
2167 	 * and unknown (reserved) frames are useless.
2168 	 */
2169 	if (rx->skb->len < 24)
2170 		return RX_DROP_MONITOR;
2171 
2172 	if (!ieee80211_is_mgmt(mgmt->frame_control))
2173 		return RX_DROP_MONITOR;
2174 
2175 	if (rx->sdata->vif.type == NL80211_IFTYPE_AP &&
2176 	    ieee80211_is_beacon(mgmt->frame_control) &&
2177 	    !(rx->flags & IEEE80211_RX_BEACON_REPORTED)) {
2178 		int sig = 0;
2179 
2180 		if (rx->local->hw.flags & IEEE80211_HW_SIGNAL_DBM)
2181 			sig = status->signal;
2182 
2183 		cfg80211_report_obss_beacon(rx->local->hw.wiphy,
2184 					    rx->skb->data, rx->skb->len,
2185 					    status->freq, sig, GFP_ATOMIC);
2186 		rx->flags |= IEEE80211_RX_BEACON_REPORTED;
2187 	}
2188 
2189 	if (!(status->rx_flags & IEEE80211_RX_RA_MATCH))
2190 		return RX_DROP_MONITOR;
2191 
2192 	if (ieee80211_drop_unencrypted_mgmt(rx))
2193 		return RX_DROP_UNUSABLE;
2194 
2195 	return RX_CONTINUE;
2196 }
2197 
2198 static ieee80211_rx_result debug_noinline
2199 ieee80211_rx_h_action(struct ieee80211_rx_data *rx)
2200 {
2201 	struct ieee80211_local *local = rx->local;
2202 	struct ieee80211_sub_if_data *sdata = rx->sdata;
2203 	struct ieee80211_mgmt *mgmt = (struct ieee80211_mgmt *) rx->skb->data;
2204 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
2205 	int len = rx->skb->len;
2206 
2207 	if (!ieee80211_is_action(mgmt->frame_control))
2208 		return RX_CONTINUE;
2209 
2210 	/* drop too small frames */
2211 	if (len < IEEE80211_MIN_ACTION_SIZE)
2212 		return RX_DROP_UNUSABLE;
2213 
2214 	if (!rx->sta && mgmt->u.action.category != WLAN_CATEGORY_PUBLIC)
2215 		return RX_DROP_UNUSABLE;
2216 
2217 	if (!(status->rx_flags & IEEE80211_RX_RA_MATCH))
2218 		return RX_DROP_UNUSABLE;
2219 
2220 	switch (mgmt->u.action.category) {
2221 	case WLAN_CATEGORY_HT:
2222 		/* reject HT action frames from stations not supporting HT */
2223 		if (!rx->sta->sta.ht_cap.ht_supported)
2224 			goto invalid;
2225 
2226 		if (sdata->vif.type != NL80211_IFTYPE_STATION &&
2227 		    sdata->vif.type != NL80211_IFTYPE_MESH_POINT &&
2228 		    sdata->vif.type != NL80211_IFTYPE_AP_VLAN &&
2229 		    sdata->vif.type != NL80211_IFTYPE_AP &&
2230 		    sdata->vif.type != NL80211_IFTYPE_ADHOC)
2231 			break;
2232 
2233 		/* verify action & smps_control are present */
2234 		if (len < IEEE80211_MIN_ACTION_SIZE + 2)
2235 			goto invalid;
2236 
2237 		switch (mgmt->u.action.u.ht_smps.action) {
2238 		case WLAN_HT_ACTION_SMPS: {
2239 			struct ieee80211_supported_band *sband;
2240 			u8 smps;
2241 
2242 			/* convert to HT capability */
2243 			switch (mgmt->u.action.u.ht_smps.smps_control) {
2244 			case WLAN_HT_SMPS_CONTROL_DISABLED:
2245 				smps = WLAN_HT_CAP_SM_PS_DISABLED;
2246 				break;
2247 			case WLAN_HT_SMPS_CONTROL_STATIC:
2248 				smps = WLAN_HT_CAP_SM_PS_STATIC;
2249 				break;
2250 			case WLAN_HT_SMPS_CONTROL_DYNAMIC:
2251 				smps = WLAN_HT_CAP_SM_PS_DYNAMIC;
2252 				break;
2253 			default:
2254 				goto invalid;
2255 			}
2256 			smps <<= IEEE80211_HT_CAP_SM_PS_SHIFT;
2257 
2258 			/* if no change do nothing */
2259 			if ((rx->sta->sta.ht_cap.cap &
2260 					IEEE80211_HT_CAP_SM_PS) == smps)
2261 				goto handled;
2262 
2263 			rx->sta->sta.ht_cap.cap &= ~IEEE80211_HT_CAP_SM_PS;
2264 			rx->sta->sta.ht_cap.cap |= smps;
2265 
2266 			sband = rx->local->hw.wiphy->bands[status->band];
2267 
2268 			rate_control_rate_update(local, sband, rx->sta,
2269 						 IEEE80211_RC_SMPS_CHANGED);
2270 			goto handled;
2271 		}
2272 		default:
2273 			goto invalid;
2274 		}
2275 
2276 		break;
2277 	case WLAN_CATEGORY_BACK:
2278 		if (sdata->vif.type != NL80211_IFTYPE_STATION &&
2279 		    sdata->vif.type != NL80211_IFTYPE_MESH_POINT &&
2280 		    sdata->vif.type != NL80211_IFTYPE_AP_VLAN &&
2281 		    sdata->vif.type != NL80211_IFTYPE_AP &&
2282 		    sdata->vif.type != NL80211_IFTYPE_ADHOC)
2283 			break;
2284 
2285 		/* verify action_code is present */
2286 		if (len < IEEE80211_MIN_ACTION_SIZE + 1)
2287 			break;
2288 
2289 		switch (mgmt->u.action.u.addba_req.action_code) {
2290 		case WLAN_ACTION_ADDBA_REQ:
2291 			if (len < (IEEE80211_MIN_ACTION_SIZE +
2292 				   sizeof(mgmt->u.action.u.addba_req)))
2293 				goto invalid;
2294 			break;
2295 		case WLAN_ACTION_ADDBA_RESP:
2296 			if (len < (IEEE80211_MIN_ACTION_SIZE +
2297 				   sizeof(mgmt->u.action.u.addba_resp)))
2298 				goto invalid;
2299 			break;
2300 		case WLAN_ACTION_DELBA:
2301 			if (len < (IEEE80211_MIN_ACTION_SIZE +
2302 				   sizeof(mgmt->u.action.u.delba)))
2303 				goto invalid;
2304 			break;
2305 		default:
2306 			goto invalid;
2307 		}
2308 
2309 		goto queue;
2310 	case WLAN_CATEGORY_SPECTRUM_MGMT:
2311 		if (status->band != IEEE80211_BAND_5GHZ)
2312 			break;
2313 
2314 		if (sdata->vif.type != NL80211_IFTYPE_STATION)
2315 			break;
2316 
2317 		/* verify action_code is present */
2318 		if (len < IEEE80211_MIN_ACTION_SIZE + 1)
2319 			break;
2320 
2321 		switch (mgmt->u.action.u.measurement.action_code) {
2322 		case WLAN_ACTION_SPCT_MSR_REQ:
2323 			if (len < (IEEE80211_MIN_ACTION_SIZE +
2324 				   sizeof(mgmt->u.action.u.measurement)))
2325 				break;
2326 			ieee80211_process_measurement_req(sdata, mgmt, len);
2327 			goto handled;
2328 		case WLAN_ACTION_SPCT_CHL_SWITCH:
2329 			if (len < (IEEE80211_MIN_ACTION_SIZE +
2330 				   sizeof(mgmt->u.action.u.chan_switch)))
2331 				break;
2332 
2333 			if (sdata->vif.type != NL80211_IFTYPE_STATION)
2334 				break;
2335 
2336 			if (!ether_addr_equal(mgmt->bssid, sdata->u.mgd.bssid))
2337 				break;
2338 
2339 			goto queue;
2340 		}
2341 		break;
2342 	case WLAN_CATEGORY_SA_QUERY:
2343 		if (len < (IEEE80211_MIN_ACTION_SIZE +
2344 			   sizeof(mgmt->u.action.u.sa_query)))
2345 			break;
2346 
2347 		switch (mgmt->u.action.u.sa_query.action) {
2348 		case WLAN_ACTION_SA_QUERY_REQUEST:
2349 			if (sdata->vif.type != NL80211_IFTYPE_STATION)
2350 				break;
2351 			ieee80211_process_sa_query_req(sdata, mgmt, len);
2352 			goto handled;
2353 		}
2354 		break;
2355 	case WLAN_CATEGORY_SELF_PROTECTED:
2356 		switch (mgmt->u.action.u.self_prot.action_code) {
2357 		case WLAN_SP_MESH_PEERING_OPEN:
2358 		case WLAN_SP_MESH_PEERING_CLOSE:
2359 		case WLAN_SP_MESH_PEERING_CONFIRM:
2360 			if (!ieee80211_vif_is_mesh(&sdata->vif))
2361 				goto invalid;
2362 			if (sdata->u.mesh.security != IEEE80211_MESH_SEC_NONE)
2363 				/* userspace handles this frame */
2364 				break;
2365 			goto queue;
2366 		case WLAN_SP_MGK_INFORM:
2367 		case WLAN_SP_MGK_ACK:
2368 			if (!ieee80211_vif_is_mesh(&sdata->vif))
2369 				goto invalid;
2370 			break;
2371 		}
2372 		break;
2373 	case WLAN_CATEGORY_MESH_ACTION:
2374 		if (!ieee80211_vif_is_mesh(&sdata->vif))
2375 			break;
2376 		if (mesh_action_is_path_sel(mgmt) &&
2377 		  (!mesh_path_sel_is_hwmp(sdata)))
2378 			break;
2379 		goto queue;
2380 	}
2381 
2382 	return RX_CONTINUE;
2383 
2384  invalid:
2385 	status->rx_flags |= IEEE80211_RX_MALFORMED_ACTION_FRM;
2386 	/* will return in the next handlers */
2387 	return RX_CONTINUE;
2388 
2389  handled:
2390 	if (rx->sta)
2391 		rx->sta->rx_packets++;
2392 	dev_kfree_skb(rx->skb);
2393 	return RX_QUEUED;
2394 
2395  queue:
2396 	rx->skb->pkt_type = IEEE80211_SDATA_QUEUE_TYPE_FRAME;
2397 	skb_queue_tail(&sdata->skb_queue, rx->skb);
2398 	ieee80211_queue_work(&local->hw, &sdata->work);
2399 	if (rx->sta)
2400 		rx->sta->rx_packets++;
2401 	return RX_QUEUED;
2402 }
2403 
2404 static ieee80211_rx_result debug_noinline
2405 ieee80211_rx_h_userspace_mgmt(struct ieee80211_rx_data *rx)
2406 {
2407 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
2408 	int sig = 0;
2409 
2410 	/* skip known-bad action frames and return them in the next handler */
2411 	if (status->rx_flags & IEEE80211_RX_MALFORMED_ACTION_FRM)
2412 		return RX_CONTINUE;
2413 
2414 	/*
2415 	 * Getting here means the kernel doesn't know how to handle
2416 	 * it, but maybe userspace does ... include returned frames
2417 	 * so userspace can register for those to know whether ones
2418 	 * it transmitted were processed or returned.
2419 	 */
2420 
2421 	if (rx->local->hw.flags & IEEE80211_HW_SIGNAL_DBM)
2422 		sig = status->signal;
2423 
2424 	if (cfg80211_rx_mgmt(&rx->sdata->wdev, status->freq, sig,
2425 			     rx->skb->data, rx->skb->len,
2426 			     GFP_ATOMIC)) {
2427 		if (rx->sta)
2428 			rx->sta->rx_packets++;
2429 		dev_kfree_skb(rx->skb);
2430 		return RX_QUEUED;
2431 	}
2432 
2433 
2434 	return RX_CONTINUE;
2435 }
2436 
2437 static ieee80211_rx_result debug_noinline
2438 ieee80211_rx_h_action_return(struct ieee80211_rx_data *rx)
2439 {
2440 	struct ieee80211_local *local = rx->local;
2441 	struct ieee80211_mgmt *mgmt = (struct ieee80211_mgmt *) rx->skb->data;
2442 	struct sk_buff *nskb;
2443 	struct ieee80211_sub_if_data *sdata = rx->sdata;
2444 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
2445 
2446 	if (!ieee80211_is_action(mgmt->frame_control))
2447 		return RX_CONTINUE;
2448 
2449 	/*
2450 	 * For AP mode, hostapd is responsible for handling any action
2451 	 * frames that we didn't handle, including returning unknown
2452 	 * ones. For all other modes we will return them to the sender,
2453 	 * setting the 0x80 bit in the action category, as required by
2454 	 * 802.11-2012 9.24.4.
2455 	 * Newer versions of hostapd shall also use the management frame
2456 	 * registration mechanisms, but older ones still use cooked
2457 	 * monitor interfaces so push all frames there.
2458 	 */
2459 	if (!(status->rx_flags & IEEE80211_RX_MALFORMED_ACTION_FRM) &&
2460 	    (sdata->vif.type == NL80211_IFTYPE_AP ||
2461 	     sdata->vif.type == NL80211_IFTYPE_AP_VLAN))
2462 		return RX_DROP_MONITOR;
2463 
2464 	if (is_multicast_ether_addr(mgmt->da))
2465 		return RX_DROP_MONITOR;
2466 
2467 	/* do not return rejected action frames */
2468 	if (mgmt->u.action.category & 0x80)
2469 		return RX_DROP_UNUSABLE;
2470 
2471 	nskb = skb_copy_expand(rx->skb, local->hw.extra_tx_headroom, 0,
2472 			       GFP_ATOMIC);
2473 	if (nskb) {
2474 		struct ieee80211_mgmt *nmgmt = (void *)nskb->data;
2475 
2476 		nmgmt->u.action.category |= 0x80;
2477 		memcpy(nmgmt->da, nmgmt->sa, ETH_ALEN);
2478 		memcpy(nmgmt->sa, rx->sdata->vif.addr, ETH_ALEN);
2479 
2480 		memset(nskb->cb, 0, sizeof(nskb->cb));
2481 
2482 		ieee80211_tx_skb(rx->sdata, nskb);
2483 	}
2484 	dev_kfree_skb(rx->skb);
2485 	return RX_QUEUED;
2486 }
2487 
2488 static ieee80211_rx_result debug_noinline
2489 ieee80211_rx_h_mgmt(struct ieee80211_rx_data *rx)
2490 {
2491 	struct ieee80211_sub_if_data *sdata = rx->sdata;
2492 	struct ieee80211_mgmt *mgmt = (void *)rx->skb->data;
2493 	__le16 stype;
2494 
2495 	stype = mgmt->frame_control & cpu_to_le16(IEEE80211_FCTL_STYPE);
2496 
2497 	if (!ieee80211_vif_is_mesh(&sdata->vif) &&
2498 	    sdata->vif.type != NL80211_IFTYPE_ADHOC &&
2499 	    sdata->vif.type != NL80211_IFTYPE_STATION)
2500 		return RX_DROP_MONITOR;
2501 
2502 	switch (stype) {
2503 	case cpu_to_le16(IEEE80211_STYPE_AUTH):
2504 	case cpu_to_le16(IEEE80211_STYPE_BEACON):
2505 	case cpu_to_le16(IEEE80211_STYPE_PROBE_RESP):
2506 		/* process for all: mesh, mlme, ibss */
2507 		break;
2508 	case cpu_to_le16(IEEE80211_STYPE_ASSOC_RESP):
2509 	case cpu_to_le16(IEEE80211_STYPE_REASSOC_RESP):
2510 	case cpu_to_le16(IEEE80211_STYPE_DEAUTH):
2511 	case cpu_to_le16(IEEE80211_STYPE_DISASSOC):
2512 		if (is_multicast_ether_addr(mgmt->da) &&
2513 		    !is_broadcast_ether_addr(mgmt->da))
2514 			return RX_DROP_MONITOR;
2515 
2516 		/* process only for station */
2517 		if (sdata->vif.type != NL80211_IFTYPE_STATION)
2518 			return RX_DROP_MONITOR;
2519 		break;
2520 	case cpu_to_le16(IEEE80211_STYPE_PROBE_REQ):
2521 		/* process only for ibss */
2522 		if (sdata->vif.type != NL80211_IFTYPE_ADHOC)
2523 			return RX_DROP_MONITOR;
2524 		break;
2525 	default:
2526 		return RX_DROP_MONITOR;
2527 	}
2528 
2529 	/* queue up frame and kick off work to process it */
2530 	rx->skb->pkt_type = IEEE80211_SDATA_QUEUE_TYPE_FRAME;
2531 	skb_queue_tail(&sdata->skb_queue, rx->skb);
2532 	ieee80211_queue_work(&rx->local->hw, &sdata->work);
2533 	if (rx->sta)
2534 		rx->sta->rx_packets++;
2535 
2536 	return RX_QUEUED;
2537 }
2538 
2539 /* TODO: use IEEE80211_RX_FRAGMENTED */
2540 static void ieee80211_rx_cooked_monitor(struct ieee80211_rx_data *rx,
2541 					struct ieee80211_rate *rate)
2542 {
2543 	struct ieee80211_sub_if_data *sdata;
2544 	struct ieee80211_local *local = rx->local;
2545 	struct sk_buff *skb = rx->skb, *skb2;
2546 	struct net_device *prev_dev = NULL;
2547 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
2548 	int needed_headroom;
2549 
2550 	/*
2551 	 * If cooked monitor has been processed already, then
2552 	 * don't do it again. If not, set the flag.
2553 	 */
2554 	if (rx->flags & IEEE80211_RX_CMNTR)
2555 		goto out_free_skb;
2556 	rx->flags |= IEEE80211_RX_CMNTR;
2557 
2558 	/* If there are no cooked monitor interfaces, just free the SKB */
2559 	if (!local->cooked_mntrs)
2560 		goto out_free_skb;
2561 
2562 	/* room for the radiotap header based on driver features */
2563 	needed_headroom = ieee80211_rx_radiotap_len(local, status);
2564 
2565 	if (skb_headroom(skb) < needed_headroom &&
2566 	    pskb_expand_head(skb, needed_headroom, 0, GFP_ATOMIC))
2567 		goto out_free_skb;
2568 
2569 	/* prepend radiotap information */
2570 	ieee80211_add_rx_radiotap_header(local, skb, rate, needed_headroom,
2571 					 false);
2572 
2573 	skb_set_mac_header(skb, 0);
2574 	skb->ip_summed = CHECKSUM_UNNECESSARY;
2575 	skb->pkt_type = PACKET_OTHERHOST;
2576 	skb->protocol = htons(ETH_P_802_2);
2577 
2578 	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
2579 		if (!ieee80211_sdata_running(sdata))
2580 			continue;
2581 
2582 		if (sdata->vif.type != NL80211_IFTYPE_MONITOR ||
2583 		    !(sdata->u.mntr_flags & MONITOR_FLAG_COOK_FRAMES))
2584 			continue;
2585 
2586 		if (prev_dev) {
2587 			skb2 = skb_clone(skb, GFP_ATOMIC);
2588 			if (skb2) {
2589 				skb2->dev = prev_dev;
2590 				netif_receive_skb(skb2);
2591 			}
2592 		}
2593 
2594 		prev_dev = sdata->dev;
2595 		sdata->dev->stats.rx_packets++;
2596 		sdata->dev->stats.rx_bytes += skb->len;
2597 	}
2598 
2599 	if (prev_dev) {
2600 		skb->dev = prev_dev;
2601 		netif_receive_skb(skb);
2602 		return;
2603 	}
2604 
2605  out_free_skb:
2606 	dev_kfree_skb(skb);
2607 }
2608 
2609 static void ieee80211_rx_handlers_result(struct ieee80211_rx_data *rx,
2610 					 ieee80211_rx_result res)
2611 {
2612 	switch (res) {
2613 	case RX_DROP_MONITOR:
2614 		I802_DEBUG_INC(rx->sdata->local->rx_handlers_drop);
2615 		if (rx->sta)
2616 			rx->sta->rx_dropped++;
2617 		/* fall through */
2618 	case RX_CONTINUE: {
2619 		struct ieee80211_rate *rate = NULL;
2620 		struct ieee80211_supported_band *sband;
2621 		struct ieee80211_rx_status *status;
2622 
2623 		status = IEEE80211_SKB_RXCB((rx->skb));
2624 
2625 		sband = rx->local->hw.wiphy->bands[status->band];
2626 		if (!(status->flag & RX_FLAG_HT))
2627 			rate = &sband->bitrates[status->rate_idx];
2628 
2629 		ieee80211_rx_cooked_monitor(rx, rate);
2630 		break;
2631 		}
2632 	case RX_DROP_UNUSABLE:
2633 		I802_DEBUG_INC(rx->sdata->local->rx_handlers_drop);
2634 		if (rx->sta)
2635 			rx->sta->rx_dropped++;
2636 		dev_kfree_skb(rx->skb);
2637 		break;
2638 	case RX_QUEUED:
2639 		I802_DEBUG_INC(rx->sdata->local->rx_handlers_queued);
2640 		break;
2641 	}
2642 }
2643 
2644 static void ieee80211_rx_handlers(struct ieee80211_rx_data *rx)
2645 {
2646 	ieee80211_rx_result res = RX_DROP_MONITOR;
2647 	struct sk_buff *skb;
2648 
2649 #define CALL_RXH(rxh)			\
2650 	do {				\
2651 		res = rxh(rx);		\
2652 		if (res != RX_CONTINUE)	\
2653 			goto rxh_next;  \
2654 	} while (0);
2655 
2656 	spin_lock(&rx->local->rx_skb_queue.lock);
2657 	if (rx->local->running_rx_handler)
2658 		goto unlock;
2659 
2660 	rx->local->running_rx_handler = true;
2661 
2662 	while ((skb = __skb_dequeue(&rx->local->rx_skb_queue))) {
2663 		spin_unlock(&rx->local->rx_skb_queue.lock);
2664 
2665 		/*
2666 		 * all the other fields are valid across frames
2667 		 * that belong to an aMPDU since they are on the
2668 		 * same TID from the same station
2669 		 */
2670 		rx->skb = skb;
2671 
2672 		CALL_RXH(ieee80211_rx_h_decrypt)
2673 		CALL_RXH(ieee80211_rx_h_check_more_data)
2674 		CALL_RXH(ieee80211_rx_h_uapsd_and_pspoll)
2675 		CALL_RXH(ieee80211_rx_h_sta_process)
2676 		CALL_RXH(ieee80211_rx_h_defragment)
2677 		CALL_RXH(ieee80211_rx_h_michael_mic_verify)
2678 		/* must be after MMIC verify so header is counted in MPDU mic */
2679 #ifdef CONFIG_MAC80211_MESH
2680 		if (ieee80211_vif_is_mesh(&rx->sdata->vif))
2681 			CALL_RXH(ieee80211_rx_h_mesh_fwding);
2682 #endif
2683 		CALL_RXH(ieee80211_rx_h_amsdu)
2684 		CALL_RXH(ieee80211_rx_h_data)
2685 		CALL_RXH(ieee80211_rx_h_ctrl);
2686 		CALL_RXH(ieee80211_rx_h_mgmt_check)
2687 		CALL_RXH(ieee80211_rx_h_action)
2688 		CALL_RXH(ieee80211_rx_h_userspace_mgmt)
2689 		CALL_RXH(ieee80211_rx_h_action_return)
2690 		CALL_RXH(ieee80211_rx_h_mgmt)
2691 
2692  rxh_next:
2693 		ieee80211_rx_handlers_result(rx, res);
2694 		spin_lock(&rx->local->rx_skb_queue.lock);
2695 #undef CALL_RXH
2696 	}
2697 
2698 	rx->local->running_rx_handler = false;
2699 
2700  unlock:
2701 	spin_unlock(&rx->local->rx_skb_queue.lock);
2702 }
2703 
2704 static void ieee80211_invoke_rx_handlers(struct ieee80211_rx_data *rx)
2705 {
2706 	ieee80211_rx_result res = RX_DROP_MONITOR;
2707 
2708 #define CALL_RXH(rxh)			\
2709 	do {				\
2710 		res = rxh(rx);		\
2711 		if (res != RX_CONTINUE)	\
2712 			goto rxh_next;  \
2713 	} while (0);
2714 
2715 	CALL_RXH(ieee80211_rx_h_check)
2716 
2717 	ieee80211_rx_reorder_ampdu(rx);
2718 
2719 	ieee80211_rx_handlers(rx);
2720 	return;
2721 
2722  rxh_next:
2723 	ieee80211_rx_handlers_result(rx, res);
2724 
2725 #undef CALL_RXH
2726 }
2727 
2728 /*
2729  * This function makes calls into the RX path, therefore
2730  * it has to be invoked under RCU read lock.
2731  */
2732 void ieee80211_release_reorder_timeout(struct sta_info *sta, int tid)
2733 {
2734 	struct ieee80211_rx_data rx = {
2735 		.sta = sta,
2736 		.sdata = sta->sdata,
2737 		.local = sta->local,
2738 		/* This is OK -- must be QoS data frame */
2739 		.security_idx = tid,
2740 		.seqno_idx = tid,
2741 		.flags = 0,
2742 	};
2743 	struct tid_ampdu_rx *tid_agg_rx;
2744 
2745 	tid_agg_rx = rcu_dereference(sta->ampdu_mlme.tid_rx[tid]);
2746 	if (!tid_agg_rx)
2747 		return;
2748 
2749 	spin_lock(&tid_agg_rx->reorder_lock);
2750 	ieee80211_sta_reorder_release(sta->sdata, tid_agg_rx);
2751 	spin_unlock(&tid_agg_rx->reorder_lock);
2752 
2753 	ieee80211_rx_handlers(&rx);
2754 }
2755 
2756 /* main receive path */
2757 
2758 static int prepare_for_handlers(struct ieee80211_rx_data *rx,
2759 				struct ieee80211_hdr *hdr)
2760 {
2761 	struct ieee80211_sub_if_data *sdata = rx->sdata;
2762 	struct sk_buff *skb = rx->skb;
2763 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
2764 	u8 *bssid = ieee80211_get_bssid(hdr, skb->len, sdata->vif.type);
2765 	int multicast = is_multicast_ether_addr(hdr->addr1);
2766 
2767 	switch (sdata->vif.type) {
2768 	case NL80211_IFTYPE_STATION:
2769 		if (!bssid && !sdata->u.mgd.use_4addr)
2770 			return 0;
2771 		if (!multicast &&
2772 		    !ether_addr_equal(sdata->vif.addr, hdr->addr1)) {
2773 			if (!(sdata->dev->flags & IFF_PROMISC) ||
2774 			    sdata->u.mgd.use_4addr)
2775 				return 0;
2776 			status->rx_flags &= ~IEEE80211_RX_RA_MATCH;
2777 		}
2778 		break;
2779 	case NL80211_IFTYPE_ADHOC:
2780 		if (!bssid)
2781 			return 0;
2782 		if (ieee80211_is_beacon(hdr->frame_control)) {
2783 			return 1;
2784 		} else if (!ieee80211_bssid_match(bssid, sdata->u.ibss.bssid)) {
2785 			return 0;
2786 		} else if (!multicast &&
2787 			   !ether_addr_equal(sdata->vif.addr, hdr->addr1)) {
2788 			if (!(sdata->dev->flags & IFF_PROMISC))
2789 				return 0;
2790 			status->rx_flags &= ~IEEE80211_RX_RA_MATCH;
2791 		} else if (!rx->sta) {
2792 			int rate_idx;
2793 			if (status->flag & RX_FLAG_HT)
2794 				rate_idx = 0; /* TODO: HT rates */
2795 			else
2796 				rate_idx = status->rate_idx;
2797 			ieee80211_ibss_rx_no_sta(sdata, bssid, hdr->addr2,
2798 						 BIT(rate_idx));
2799 		}
2800 		break;
2801 	case NL80211_IFTYPE_MESH_POINT:
2802 		if (!multicast &&
2803 		    !ether_addr_equal(sdata->vif.addr, hdr->addr1)) {
2804 			if (!(sdata->dev->flags & IFF_PROMISC))
2805 				return 0;
2806 
2807 			status->rx_flags &= ~IEEE80211_RX_RA_MATCH;
2808 		}
2809 		break;
2810 	case NL80211_IFTYPE_AP_VLAN:
2811 	case NL80211_IFTYPE_AP:
2812 		if (!bssid) {
2813 			if (!ether_addr_equal(sdata->vif.addr, hdr->addr1))
2814 				return 0;
2815 		} else if (!ieee80211_bssid_match(bssid, sdata->vif.addr)) {
2816 			/*
2817 			 * Accept public action frames even when the
2818 			 * BSSID doesn't match, this is used for P2P
2819 			 * and location updates. Note that mac80211
2820 			 * itself never looks at these frames.
2821 			 */
2822 			if (ieee80211_is_public_action(hdr, skb->len))
2823 				return 1;
2824 			if (!ieee80211_is_beacon(hdr->frame_control))
2825 				return 0;
2826 			status->rx_flags &= ~IEEE80211_RX_RA_MATCH;
2827 		}
2828 		break;
2829 	case NL80211_IFTYPE_WDS:
2830 		if (bssid || !ieee80211_is_data(hdr->frame_control))
2831 			return 0;
2832 		if (!ether_addr_equal(sdata->u.wds.remote_addr, hdr->addr2))
2833 			return 0;
2834 		break;
2835 	case NL80211_IFTYPE_P2P_DEVICE:
2836 		if (!ieee80211_is_public_action(hdr, skb->len) &&
2837 		    !ieee80211_is_probe_req(hdr->frame_control) &&
2838 		    !ieee80211_is_probe_resp(hdr->frame_control) &&
2839 		    !ieee80211_is_beacon(hdr->frame_control))
2840 			return 0;
2841 		if (!ether_addr_equal(sdata->vif.addr, hdr->addr1))
2842 			status->rx_flags &= ~IEEE80211_RX_RA_MATCH;
2843 		break;
2844 	default:
2845 		/* should never get here */
2846 		WARN_ON_ONCE(1);
2847 		break;
2848 	}
2849 
2850 	return 1;
2851 }
2852 
2853 /*
2854  * This function returns whether or not the SKB
2855  * was destined for RX processing or not, which,
2856  * if consume is true, is equivalent to whether
2857  * or not the skb was consumed.
2858  */
2859 static bool ieee80211_prepare_and_rx_handle(struct ieee80211_rx_data *rx,
2860 					    struct sk_buff *skb, bool consume)
2861 {
2862 	struct ieee80211_local *local = rx->local;
2863 	struct ieee80211_sub_if_data *sdata = rx->sdata;
2864 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
2865 	struct ieee80211_hdr *hdr = (void *)skb->data;
2866 	int prepares;
2867 
2868 	rx->skb = skb;
2869 	status->rx_flags |= IEEE80211_RX_RA_MATCH;
2870 	prepares = prepare_for_handlers(rx, hdr);
2871 
2872 	if (!prepares)
2873 		return false;
2874 
2875 	if (!consume) {
2876 		skb = skb_copy(skb, GFP_ATOMIC);
2877 		if (!skb) {
2878 			if (net_ratelimit())
2879 				wiphy_debug(local->hw.wiphy,
2880 					"failed to copy skb for %s\n",
2881 					sdata->name);
2882 			return true;
2883 		}
2884 
2885 		rx->skb = skb;
2886 	}
2887 
2888 	ieee80211_invoke_rx_handlers(rx);
2889 	return true;
2890 }
2891 
2892 /*
2893  * This is the actual Rx frames handler. as it blongs to Rx path it must
2894  * be called with rcu_read_lock protection.
2895  */
2896 static void __ieee80211_rx_handle_packet(struct ieee80211_hw *hw,
2897 					 struct sk_buff *skb)
2898 {
2899 	struct ieee80211_local *local = hw_to_local(hw);
2900 	struct ieee80211_sub_if_data *sdata;
2901 	struct ieee80211_hdr *hdr;
2902 	__le16 fc;
2903 	struct ieee80211_rx_data rx;
2904 	struct ieee80211_sub_if_data *prev;
2905 	struct sta_info *sta, *tmp, *prev_sta;
2906 	int err = 0;
2907 
2908 	fc = ((struct ieee80211_hdr *)skb->data)->frame_control;
2909 	memset(&rx, 0, sizeof(rx));
2910 	rx.skb = skb;
2911 	rx.local = local;
2912 
2913 	if (ieee80211_is_data(fc) || ieee80211_is_mgmt(fc))
2914 		local->dot11ReceivedFragmentCount++;
2915 
2916 	if (ieee80211_is_mgmt(fc))
2917 		err = skb_linearize(skb);
2918 	else
2919 		err = !pskb_may_pull(skb, ieee80211_hdrlen(fc));
2920 
2921 	if (err) {
2922 		dev_kfree_skb(skb);
2923 		return;
2924 	}
2925 
2926 	hdr = (struct ieee80211_hdr *)skb->data;
2927 	ieee80211_parse_qos(&rx);
2928 	ieee80211_verify_alignment(&rx);
2929 
2930 	if (unlikely(ieee80211_is_probe_resp(hdr->frame_control) ||
2931 		     ieee80211_is_beacon(hdr->frame_control)))
2932 		ieee80211_scan_rx(local, skb);
2933 
2934 	if (ieee80211_is_data(fc)) {
2935 		prev_sta = NULL;
2936 
2937 		for_each_sta_info(local, hdr->addr2, sta, tmp) {
2938 			if (!prev_sta) {
2939 				prev_sta = sta;
2940 				continue;
2941 			}
2942 
2943 			rx.sta = prev_sta;
2944 			rx.sdata = prev_sta->sdata;
2945 			ieee80211_prepare_and_rx_handle(&rx, skb, false);
2946 
2947 			prev_sta = sta;
2948 		}
2949 
2950 		if (prev_sta) {
2951 			rx.sta = prev_sta;
2952 			rx.sdata = prev_sta->sdata;
2953 
2954 			if (ieee80211_prepare_and_rx_handle(&rx, skb, true))
2955 				return;
2956 			goto out;
2957 		}
2958 	}
2959 
2960 	prev = NULL;
2961 
2962 	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
2963 		if (!ieee80211_sdata_running(sdata))
2964 			continue;
2965 
2966 		if (sdata->vif.type == NL80211_IFTYPE_MONITOR ||
2967 		    sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
2968 			continue;
2969 
2970 		/*
2971 		 * frame is destined for this interface, but if it's
2972 		 * not also for the previous one we handle that after
2973 		 * the loop to avoid copying the SKB once too much
2974 		 */
2975 
2976 		if (!prev) {
2977 			prev = sdata;
2978 			continue;
2979 		}
2980 
2981 		rx.sta = sta_info_get_bss(prev, hdr->addr2);
2982 		rx.sdata = prev;
2983 		ieee80211_prepare_and_rx_handle(&rx, skb, false);
2984 
2985 		prev = sdata;
2986 	}
2987 
2988 	if (prev) {
2989 		rx.sta = sta_info_get_bss(prev, hdr->addr2);
2990 		rx.sdata = prev;
2991 
2992 		if (ieee80211_prepare_and_rx_handle(&rx, skb, true))
2993 			return;
2994 	}
2995 
2996  out:
2997 	dev_kfree_skb(skb);
2998 }
2999 
3000 /*
3001  * This is the receive path handler. It is called by a low level driver when an
3002  * 802.11 MPDU is received from the hardware.
3003  */
3004 void ieee80211_rx(struct ieee80211_hw *hw, struct sk_buff *skb)
3005 {
3006 	struct ieee80211_local *local = hw_to_local(hw);
3007 	struct ieee80211_rate *rate = NULL;
3008 	struct ieee80211_supported_band *sband;
3009 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
3010 
3011 	WARN_ON_ONCE(softirq_count() == 0);
3012 
3013 	if (WARN_ON(status->band < 0 ||
3014 		    status->band >= IEEE80211_NUM_BANDS))
3015 		goto drop;
3016 
3017 	sband = local->hw.wiphy->bands[status->band];
3018 	if (WARN_ON(!sband))
3019 		goto drop;
3020 
3021 	/*
3022 	 * If we're suspending, it is possible although not too likely
3023 	 * that we'd be receiving frames after having already partially
3024 	 * quiesced the stack. We can't process such frames then since
3025 	 * that might, for example, cause stations to be added or other
3026 	 * driver callbacks be invoked.
3027 	 */
3028 	if (unlikely(local->quiescing || local->suspended))
3029 		goto drop;
3030 
3031 	/* We might be during a HW reconfig, prevent Rx for the same reason */
3032 	if (unlikely(local->in_reconfig))
3033 		goto drop;
3034 
3035 	/*
3036 	 * The same happens when we're not even started,
3037 	 * but that's worth a warning.
3038 	 */
3039 	if (WARN_ON(!local->started))
3040 		goto drop;
3041 
3042 	if (likely(!(status->flag & RX_FLAG_FAILED_PLCP_CRC))) {
3043 		/*
3044 		 * Validate the rate, unless a PLCP error means that
3045 		 * we probably can't have a valid rate here anyway.
3046 		 */
3047 
3048 		if (status->flag & RX_FLAG_HT) {
3049 			/*
3050 			 * rate_idx is MCS index, which can be [0-76]
3051 			 * as documented on:
3052 			 *
3053 			 * http://wireless.kernel.org/en/developers/Documentation/ieee80211/802.11n
3054 			 *
3055 			 * Anything else would be some sort of driver or
3056 			 * hardware error. The driver should catch hardware
3057 			 * errors.
3058 			 */
3059 			if (WARN((status->rate_idx < 0 ||
3060 				 status->rate_idx > 76),
3061 				 "Rate marked as an HT rate but passed "
3062 				 "status->rate_idx is not "
3063 				 "an MCS index [0-76]: %d (0x%02x)\n",
3064 				 status->rate_idx,
3065 				 status->rate_idx))
3066 				goto drop;
3067 		} else {
3068 			if (WARN_ON(status->rate_idx < 0 ||
3069 				    status->rate_idx >= sband->n_bitrates))
3070 				goto drop;
3071 			rate = &sband->bitrates[status->rate_idx];
3072 		}
3073 	}
3074 
3075 	status->rx_flags = 0;
3076 
3077 	/*
3078 	 * key references and virtual interfaces are protected using RCU
3079 	 * and this requires that we are in a read-side RCU section during
3080 	 * receive processing
3081 	 */
3082 	rcu_read_lock();
3083 
3084 	/*
3085 	 * Frames with failed FCS/PLCP checksum are not returned,
3086 	 * all other frames are returned without radiotap header
3087 	 * if it was previously present.
3088 	 * Also, frames with less than 16 bytes are dropped.
3089 	 */
3090 	skb = ieee80211_rx_monitor(local, skb, rate);
3091 	if (!skb) {
3092 		rcu_read_unlock();
3093 		return;
3094 	}
3095 
3096 	ieee80211_tpt_led_trig_rx(local,
3097 			((struct ieee80211_hdr *)skb->data)->frame_control,
3098 			skb->len);
3099 	__ieee80211_rx_handle_packet(hw, skb);
3100 
3101 	rcu_read_unlock();
3102 
3103 	return;
3104  drop:
3105 	kfree_skb(skb);
3106 }
3107 EXPORT_SYMBOL(ieee80211_rx);
3108 
3109 /* This is a version of the rx handler that can be called from hard irq
3110  * context. Post the skb on the queue and schedule the tasklet */
3111 void ieee80211_rx_irqsafe(struct ieee80211_hw *hw, struct sk_buff *skb)
3112 {
3113 	struct ieee80211_local *local = hw_to_local(hw);
3114 
3115 	BUILD_BUG_ON(sizeof(struct ieee80211_rx_status) > sizeof(skb->cb));
3116 
3117 	skb->pkt_type = IEEE80211_RX_MSG;
3118 	skb_queue_tail(&local->skb_queue, skb);
3119 	tasklet_schedule(&local->tasklet);
3120 }
3121 EXPORT_SYMBOL(ieee80211_rx_irqsafe);
3122