xref: /linux/net/mac80211/rx.c (revision 9e8ba5f3ec35cba4fd8a8bebda548c4db2651e40)
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 
23 #include "ieee80211_i.h"
24 #include "driver-ops.h"
25 #include "led.h"
26 #include "mesh.h"
27 #include "wep.h"
28 #include "wpa.h"
29 #include "tkip.h"
30 #include "wme.h"
31 
32 /*
33  * monitor mode reception
34  *
35  * This function cleans up the SKB, i.e. it removes all the stuff
36  * only useful for monitoring.
37  */
38 static struct sk_buff *remove_monitor_info(struct ieee80211_local *local,
39 					   struct sk_buff *skb)
40 {
41 	if (local->hw.flags & IEEE80211_HW_RX_INCLUDES_FCS) {
42 		if (likely(skb->len > FCS_LEN))
43 			__pskb_trim(skb, skb->len - FCS_LEN);
44 		else {
45 			/* driver bug */
46 			WARN_ON(1);
47 			dev_kfree_skb(skb);
48 			skb = NULL;
49 		}
50 	}
51 
52 	return skb;
53 }
54 
55 static inline int should_drop_frame(struct sk_buff *skb,
56 				    int present_fcs_len)
57 {
58 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
59 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
60 
61 	if (status->flag & (RX_FLAG_FAILED_FCS_CRC | RX_FLAG_FAILED_PLCP_CRC))
62 		return 1;
63 	if (unlikely(skb->len < 16 + present_fcs_len))
64 		return 1;
65 	if (ieee80211_is_ctl(hdr->frame_control) &&
66 	    !ieee80211_is_pspoll(hdr->frame_control) &&
67 	    !ieee80211_is_back_req(hdr->frame_control))
68 		return 1;
69 	return 0;
70 }
71 
72 static int
73 ieee80211_rx_radiotap_len(struct ieee80211_local *local,
74 			  struct ieee80211_rx_status *status)
75 {
76 	int len;
77 
78 	/* always present fields */
79 	len = sizeof(struct ieee80211_radiotap_header) + 9;
80 
81 	if (status->flag & RX_FLAG_MACTIME_MPDU)
82 		len += 8;
83 	if (local->hw.flags & IEEE80211_HW_SIGNAL_DBM)
84 		len += 1;
85 
86 	if (len & 1) /* padding for RX_FLAGS if necessary */
87 		len++;
88 
89 	if (status->flag & RX_FLAG_HT) /* HT info */
90 		len += 3;
91 
92 	return len;
93 }
94 
95 /*
96  * ieee80211_add_rx_radiotap_header - add radiotap header
97  *
98  * add a radiotap header containing all the fields which the hardware provided.
99  */
100 static void
101 ieee80211_add_rx_radiotap_header(struct ieee80211_local *local,
102 				 struct sk_buff *skb,
103 				 struct ieee80211_rate *rate,
104 				 int rtap_len)
105 {
106 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
107 	struct ieee80211_radiotap_header *rthdr;
108 	unsigned char *pos;
109 	u16 rx_flags = 0;
110 
111 	rthdr = (struct ieee80211_radiotap_header *)skb_push(skb, rtap_len);
112 	memset(rthdr, 0, rtap_len);
113 
114 	/* radiotap header, set always present flags */
115 	rthdr->it_present =
116 		cpu_to_le32((1 << IEEE80211_RADIOTAP_FLAGS) |
117 			    (1 << IEEE80211_RADIOTAP_CHANNEL) |
118 			    (1 << IEEE80211_RADIOTAP_ANTENNA) |
119 			    (1 << IEEE80211_RADIOTAP_RX_FLAGS));
120 	rthdr->it_len = cpu_to_le16(rtap_len);
121 
122 	pos = (unsigned char *)(rthdr+1);
123 
124 	/* the order of the following fields is important */
125 
126 	/* IEEE80211_RADIOTAP_TSFT */
127 	if (status->flag & RX_FLAG_MACTIME_MPDU) {
128 		put_unaligned_le64(status->mactime, pos);
129 		rthdr->it_present |=
130 			cpu_to_le32(1 << IEEE80211_RADIOTAP_TSFT);
131 		pos += 8;
132 	}
133 
134 	/* IEEE80211_RADIOTAP_FLAGS */
135 	if (local->hw.flags & IEEE80211_HW_RX_INCLUDES_FCS)
136 		*pos |= IEEE80211_RADIOTAP_F_FCS;
137 	if (status->flag & (RX_FLAG_FAILED_FCS_CRC | RX_FLAG_FAILED_PLCP_CRC))
138 		*pos |= IEEE80211_RADIOTAP_F_BADFCS;
139 	if (status->flag & RX_FLAG_SHORTPRE)
140 		*pos |= IEEE80211_RADIOTAP_F_SHORTPRE;
141 	pos++;
142 
143 	/* IEEE80211_RADIOTAP_RATE */
144 	if (!rate || status->flag & RX_FLAG_HT) {
145 		/*
146 		 * Without rate information don't add it. If we have,
147 		 * MCS information is a separate field in radiotap,
148 		 * added below. The byte here is needed as padding
149 		 * for the channel though, so initialise it to 0.
150 		 */
151 		*pos = 0;
152 	} else {
153 		rthdr->it_present |= cpu_to_le32(1 << IEEE80211_RADIOTAP_RATE);
154 		*pos = rate->bitrate / 5;
155 	}
156 	pos++;
157 
158 	/* IEEE80211_RADIOTAP_CHANNEL */
159 	put_unaligned_le16(status->freq, pos);
160 	pos += 2;
161 	if (status->band == IEEE80211_BAND_5GHZ)
162 		put_unaligned_le16(IEEE80211_CHAN_OFDM | IEEE80211_CHAN_5GHZ,
163 				   pos);
164 	else if (status->flag & RX_FLAG_HT)
165 		put_unaligned_le16(IEEE80211_CHAN_DYN | IEEE80211_CHAN_2GHZ,
166 				   pos);
167 	else if (rate && rate->flags & IEEE80211_RATE_ERP_G)
168 		put_unaligned_le16(IEEE80211_CHAN_OFDM | IEEE80211_CHAN_2GHZ,
169 				   pos);
170 	else if (rate)
171 		put_unaligned_le16(IEEE80211_CHAN_CCK | IEEE80211_CHAN_2GHZ,
172 				   pos);
173 	else
174 		put_unaligned_le16(IEEE80211_CHAN_2GHZ, pos);
175 	pos += 2;
176 
177 	/* IEEE80211_RADIOTAP_DBM_ANTSIGNAL */
178 	if (local->hw.flags & IEEE80211_HW_SIGNAL_DBM) {
179 		*pos = status->signal;
180 		rthdr->it_present |=
181 			cpu_to_le32(1 << IEEE80211_RADIOTAP_DBM_ANTSIGNAL);
182 		pos++;
183 	}
184 
185 	/* IEEE80211_RADIOTAP_LOCK_QUALITY is missing */
186 
187 	/* IEEE80211_RADIOTAP_ANTENNA */
188 	*pos = status->antenna;
189 	pos++;
190 
191 	/* IEEE80211_RADIOTAP_DB_ANTNOISE is not used */
192 
193 	/* IEEE80211_RADIOTAP_RX_FLAGS */
194 	/* ensure 2 byte alignment for the 2 byte field as required */
195 	if ((pos - (u8 *)rthdr) & 1)
196 		pos++;
197 	if (status->flag & RX_FLAG_FAILED_PLCP_CRC)
198 		rx_flags |= IEEE80211_RADIOTAP_F_RX_BADPLCP;
199 	put_unaligned_le16(rx_flags, pos);
200 	pos += 2;
201 
202 	if (status->flag & RX_FLAG_HT) {
203 		rthdr->it_present |= cpu_to_le32(1 << IEEE80211_RADIOTAP_MCS);
204 		*pos++ = IEEE80211_RADIOTAP_MCS_HAVE_MCS |
205 			 IEEE80211_RADIOTAP_MCS_HAVE_GI |
206 			 IEEE80211_RADIOTAP_MCS_HAVE_BW;
207 		*pos = 0;
208 		if (status->flag & RX_FLAG_SHORT_GI)
209 			*pos |= IEEE80211_RADIOTAP_MCS_SGI;
210 		if (status->flag & RX_FLAG_40MHZ)
211 			*pos |= IEEE80211_RADIOTAP_MCS_BW_40;
212 		pos++;
213 		*pos++ = status->rate_idx;
214 	}
215 }
216 
217 /*
218  * This function copies a received frame to all monitor interfaces and
219  * returns a cleaned-up SKB that no longer includes the FCS nor the
220  * radiotap header the driver might have added.
221  */
222 static struct sk_buff *
223 ieee80211_rx_monitor(struct ieee80211_local *local, struct sk_buff *origskb,
224 		     struct ieee80211_rate *rate)
225 {
226 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(origskb);
227 	struct ieee80211_sub_if_data *sdata;
228 	int needed_headroom = 0;
229 	struct sk_buff *skb, *skb2;
230 	struct net_device *prev_dev = NULL;
231 	int present_fcs_len = 0;
232 
233 	/*
234 	 * First, we may need to make a copy of the skb because
235 	 *  (1) we need to modify it for radiotap (if not present), and
236 	 *  (2) the other RX handlers will modify the skb we got.
237 	 *
238 	 * We don't need to, of course, if we aren't going to return
239 	 * the SKB because it has a bad FCS/PLCP checksum.
240 	 */
241 
242 	/* room for the radiotap header based on driver features */
243 	needed_headroom = ieee80211_rx_radiotap_len(local, status);
244 
245 	if (local->hw.flags & IEEE80211_HW_RX_INCLUDES_FCS)
246 		present_fcs_len = FCS_LEN;
247 
248 	/* make sure hdr->frame_control is on the linear part */
249 	if (!pskb_may_pull(origskb, 2)) {
250 		dev_kfree_skb(origskb);
251 		return NULL;
252 	}
253 
254 	if (!local->monitors) {
255 		if (should_drop_frame(origskb, present_fcs_len)) {
256 			dev_kfree_skb(origskb);
257 			return NULL;
258 		}
259 
260 		return remove_monitor_info(local, origskb);
261 	}
262 
263 	if (should_drop_frame(origskb, present_fcs_len)) {
264 		/* only need to expand headroom if necessary */
265 		skb = origskb;
266 		origskb = NULL;
267 
268 		/*
269 		 * This shouldn't trigger often because most devices have an
270 		 * RX header they pull before we get here, and that should
271 		 * be big enough for our radiotap information. We should
272 		 * probably export the length to drivers so that we can have
273 		 * them allocate enough headroom to start with.
274 		 */
275 		if (skb_headroom(skb) < needed_headroom &&
276 		    pskb_expand_head(skb, needed_headroom, 0, GFP_ATOMIC)) {
277 			dev_kfree_skb(skb);
278 			return NULL;
279 		}
280 	} else {
281 		/*
282 		 * Need to make a copy and possibly remove radiotap header
283 		 * and FCS from the original.
284 		 */
285 		skb = skb_copy_expand(origskb, needed_headroom, 0, GFP_ATOMIC);
286 
287 		origskb = remove_monitor_info(local, origskb);
288 
289 		if (!skb)
290 			return origskb;
291 	}
292 
293 	/* prepend radiotap information */
294 	ieee80211_add_rx_radiotap_header(local, skb, rate, needed_headroom);
295 
296 	skb_reset_mac_header(skb);
297 	skb->ip_summed = CHECKSUM_UNNECESSARY;
298 	skb->pkt_type = PACKET_OTHERHOST;
299 	skb->protocol = htons(ETH_P_802_2);
300 
301 	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
302 		if (sdata->vif.type != NL80211_IFTYPE_MONITOR)
303 			continue;
304 
305 		if (sdata->u.mntr_flags & MONITOR_FLAG_COOK_FRAMES)
306 			continue;
307 
308 		if (!ieee80211_sdata_running(sdata))
309 			continue;
310 
311 		if (prev_dev) {
312 			skb2 = skb_clone(skb, GFP_ATOMIC);
313 			if (skb2) {
314 				skb2->dev = prev_dev;
315 				netif_receive_skb(skb2);
316 			}
317 		}
318 
319 		prev_dev = sdata->dev;
320 		sdata->dev->stats.rx_packets++;
321 		sdata->dev->stats.rx_bytes += skb->len;
322 	}
323 
324 	if (prev_dev) {
325 		skb->dev = prev_dev;
326 		netif_receive_skb(skb);
327 	} else
328 		dev_kfree_skb(skb);
329 
330 	return origskb;
331 }
332 
333 
334 static void ieee80211_parse_qos(struct ieee80211_rx_data *rx)
335 {
336 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
337 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
338 	int tid, seqno_idx, security_idx;
339 
340 	/* does the frame have a qos control field? */
341 	if (ieee80211_is_data_qos(hdr->frame_control)) {
342 		u8 *qc = ieee80211_get_qos_ctl(hdr);
343 		/* frame has qos control */
344 		tid = *qc & IEEE80211_QOS_CTL_TID_MASK;
345 		if (*qc & IEEE80211_QOS_CTL_A_MSDU_PRESENT)
346 			status->rx_flags |= IEEE80211_RX_AMSDU;
347 
348 		seqno_idx = tid;
349 		security_idx = tid;
350 	} else {
351 		/*
352 		 * IEEE 802.11-2007, 7.1.3.4.1 ("Sequence Number field"):
353 		 *
354 		 *	Sequence numbers for management frames, QoS data
355 		 *	frames with a broadcast/multicast address in the
356 		 *	Address 1 field, and all non-QoS data frames sent
357 		 *	by QoS STAs are assigned using an additional single
358 		 *	modulo-4096 counter, [...]
359 		 *
360 		 * We also use that counter for non-QoS STAs.
361 		 */
362 		seqno_idx = NUM_RX_DATA_QUEUES;
363 		security_idx = 0;
364 		if (ieee80211_is_mgmt(hdr->frame_control))
365 			security_idx = NUM_RX_DATA_QUEUES;
366 		tid = 0;
367 	}
368 
369 	rx->seqno_idx = seqno_idx;
370 	rx->security_idx = security_idx;
371 	/* Set skb->priority to 1d tag if highest order bit of TID is not set.
372 	 * For now, set skb->priority to 0 for other cases. */
373 	rx->skb->priority = (tid > 7) ? 0 : tid;
374 }
375 
376 /**
377  * DOC: Packet alignment
378  *
379  * Drivers always need to pass packets that are aligned to two-byte boundaries
380  * to the stack.
381  *
382  * Additionally, should, if possible, align the payload data in a way that
383  * guarantees that the contained IP header is aligned to a four-byte
384  * boundary. In the case of regular frames, this simply means aligning the
385  * payload to a four-byte boundary (because either the IP header is directly
386  * contained, or IV/RFC1042 headers that have a length divisible by four are
387  * in front of it).  If the payload data is not properly aligned and the
388  * architecture doesn't support efficient unaligned operations, mac80211
389  * will align the data.
390  *
391  * With A-MSDU frames, however, the payload data address must yield two modulo
392  * four because there are 14-byte 802.3 headers within the A-MSDU frames that
393  * push the IP header further back to a multiple of four again. Thankfully, the
394  * specs were sane enough this time around to require padding each A-MSDU
395  * subframe to a length that is a multiple of four.
396  *
397  * Padding like Atheros hardware adds which is between the 802.11 header and
398  * the payload is not supported, the driver is required to move the 802.11
399  * header to be directly in front of the payload in that case.
400  */
401 static void ieee80211_verify_alignment(struct ieee80211_rx_data *rx)
402 {
403 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG
404 	WARN_ONCE((unsigned long)rx->skb->data & 1,
405 		  "unaligned packet at 0x%p\n", rx->skb->data);
406 #endif
407 }
408 
409 
410 /* rx handlers */
411 
412 static ieee80211_rx_result debug_noinline
413 ieee80211_rx_h_passive_scan(struct ieee80211_rx_data *rx)
414 {
415 	struct ieee80211_local *local = rx->local;
416 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
417 	struct sk_buff *skb = rx->skb;
418 
419 	if (likely(!(status->rx_flags & IEEE80211_RX_IN_SCAN) &&
420 		   !local->sched_scanning))
421 		return RX_CONTINUE;
422 
423 	if (test_bit(SCAN_HW_SCANNING, &local->scanning) ||
424 	    test_bit(SCAN_SW_SCANNING, &local->scanning) ||
425 	    local->sched_scanning)
426 		return ieee80211_scan_rx(rx->sdata, skb);
427 
428 	/* scanning finished during invoking of handlers */
429 	I802_DEBUG_INC(local->rx_handlers_drop_passive_scan);
430 	return RX_DROP_UNUSABLE;
431 }
432 
433 
434 static int ieee80211_is_unicast_robust_mgmt_frame(struct sk_buff *skb)
435 {
436 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
437 
438 	if (skb->len < 24 || is_multicast_ether_addr(hdr->addr1))
439 		return 0;
440 
441 	return ieee80211_is_robust_mgmt_frame(hdr);
442 }
443 
444 
445 static int ieee80211_is_multicast_robust_mgmt_frame(struct sk_buff *skb)
446 {
447 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
448 
449 	if (skb->len < 24 || !is_multicast_ether_addr(hdr->addr1))
450 		return 0;
451 
452 	return ieee80211_is_robust_mgmt_frame(hdr);
453 }
454 
455 
456 /* Get the BIP key index from MMIE; return -1 if this is not a BIP frame */
457 static int ieee80211_get_mmie_keyidx(struct sk_buff *skb)
458 {
459 	struct ieee80211_mgmt *hdr = (struct ieee80211_mgmt *) skb->data;
460 	struct ieee80211_mmie *mmie;
461 
462 	if (skb->len < 24 + sizeof(*mmie) ||
463 	    !is_multicast_ether_addr(hdr->da))
464 		return -1;
465 
466 	if (!ieee80211_is_robust_mgmt_frame((struct ieee80211_hdr *) hdr))
467 		return -1; /* not a robust management frame */
468 
469 	mmie = (struct ieee80211_mmie *)
470 		(skb->data + skb->len - sizeof(*mmie));
471 	if (mmie->element_id != WLAN_EID_MMIE ||
472 	    mmie->length != sizeof(*mmie) - 2)
473 		return -1;
474 
475 	return le16_to_cpu(mmie->key_id);
476 }
477 
478 
479 static ieee80211_rx_result
480 ieee80211_rx_mesh_check(struct ieee80211_rx_data *rx)
481 {
482 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
483 	char *dev_addr = rx->sdata->vif.addr;
484 
485 	if (ieee80211_is_data(hdr->frame_control)) {
486 		if (is_multicast_ether_addr(hdr->addr1)) {
487 			if (ieee80211_has_tods(hdr->frame_control) ||
488 				!ieee80211_has_fromds(hdr->frame_control))
489 				return RX_DROP_MONITOR;
490 			if (memcmp(hdr->addr3, dev_addr, ETH_ALEN) == 0)
491 				return RX_DROP_MONITOR;
492 		} else {
493 			if (!ieee80211_has_a4(hdr->frame_control))
494 				return RX_DROP_MONITOR;
495 			if (memcmp(hdr->addr4, dev_addr, ETH_ALEN) == 0)
496 				return RX_DROP_MONITOR;
497 		}
498 	}
499 
500 	/* If there is not an established peer link and this is not a peer link
501 	 * establisment frame, beacon or probe, drop the frame.
502 	 */
503 
504 	if (!rx->sta || sta_plink_state(rx->sta) != NL80211_PLINK_ESTAB) {
505 		struct ieee80211_mgmt *mgmt;
506 
507 		if (!ieee80211_is_mgmt(hdr->frame_control))
508 			return RX_DROP_MONITOR;
509 
510 		if (ieee80211_is_action(hdr->frame_control)) {
511 			u8 category;
512 			mgmt = (struct ieee80211_mgmt *)hdr;
513 			category = mgmt->u.action.category;
514 			if (category != WLAN_CATEGORY_MESH_ACTION &&
515 				category != WLAN_CATEGORY_SELF_PROTECTED)
516 				return RX_DROP_MONITOR;
517 			return RX_CONTINUE;
518 		}
519 
520 		if (ieee80211_is_probe_req(hdr->frame_control) ||
521 		    ieee80211_is_probe_resp(hdr->frame_control) ||
522 		    ieee80211_is_beacon(hdr->frame_control) ||
523 		    ieee80211_is_auth(hdr->frame_control))
524 			return RX_CONTINUE;
525 
526 		return RX_DROP_MONITOR;
527 
528 	}
529 
530 	return RX_CONTINUE;
531 }
532 
533 #define SEQ_MODULO 0x1000
534 #define SEQ_MASK   0xfff
535 
536 static inline int seq_less(u16 sq1, u16 sq2)
537 {
538 	return ((sq1 - sq2) & SEQ_MASK) > (SEQ_MODULO >> 1);
539 }
540 
541 static inline u16 seq_inc(u16 sq)
542 {
543 	return (sq + 1) & SEQ_MASK;
544 }
545 
546 static inline u16 seq_sub(u16 sq1, u16 sq2)
547 {
548 	return (sq1 - sq2) & SEQ_MASK;
549 }
550 
551 
552 static void ieee80211_release_reorder_frame(struct ieee80211_hw *hw,
553 					    struct tid_ampdu_rx *tid_agg_rx,
554 					    int index)
555 {
556 	struct ieee80211_local *local = hw_to_local(hw);
557 	struct sk_buff *skb = tid_agg_rx->reorder_buf[index];
558 	struct ieee80211_rx_status *status;
559 
560 	lockdep_assert_held(&tid_agg_rx->reorder_lock);
561 
562 	if (!skb)
563 		goto no_frame;
564 
565 	/* release the frame from the reorder ring buffer */
566 	tid_agg_rx->stored_mpdu_num--;
567 	tid_agg_rx->reorder_buf[index] = NULL;
568 	status = IEEE80211_SKB_RXCB(skb);
569 	status->rx_flags |= IEEE80211_RX_DEFERRED_RELEASE;
570 	skb_queue_tail(&local->rx_skb_queue, skb);
571 
572 no_frame:
573 	tid_agg_rx->head_seq_num = seq_inc(tid_agg_rx->head_seq_num);
574 }
575 
576 static void ieee80211_release_reorder_frames(struct ieee80211_hw *hw,
577 					     struct tid_ampdu_rx *tid_agg_rx,
578 					     u16 head_seq_num)
579 {
580 	int index;
581 
582 	lockdep_assert_held(&tid_agg_rx->reorder_lock);
583 
584 	while (seq_less(tid_agg_rx->head_seq_num, head_seq_num)) {
585 		index = seq_sub(tid_agg_rx->head_seq_num, tid_agg_rx->ssn) %
586 							tid_agg_rx->buf_size;
587 		ieee80211_release_reorder_frame(hw, tid_agg_rx, index);
588 	}
589 }
590 
591 /*
592  * Timeout (in jiffies) for skb's that are waiting in the RX reorder buffer. If
593  * the skb was added to the buffer longer than this time ago, the earlier
594  * frames that have not yet been received are assumed to be lost and the skb
595  * can be released for processing. This may also release other skb's from the
596  * reorder buffer if there are no additional gaps between the frames.
597  *
598  * Callers must hold tid_agg_rx->reorder_lock.
599  */
600 #define HT_RX_REORDER_BUF_TIMEOUT (HZ / 10)
601 
602 static void ieee80211_sta_reorder_release(struct ieee80211_hw *hw,
603 					  struct tid_ampdu_rx *tid_agg_rx)
604 {
605 	int index, j;
606 
607 	lockdep_assert_held(&tid_agg_rx->reorder_lock);
608 
609 	/* release the buffer until next missing frame */
610 	index = seq_sub(tid_agg_rx->head_seq_num, tid_agg_rx->ssn) %
611 						tid_agg_rx->buf_size;
612 	if (!tid_agg_rx->reorder_buf[index] &&
613 	    tid_agg_rx->stored_mpdu_num > 1) {
614 		/*
615 		 * No buffers ready to be released, but check whether any
616 		 * frames in the reorder buffer have timed out.
617 		 */
618 		int skipped = 1;
619 		for (j = (index + 1) % tid_agg_rx->buf_size; j != index;
620 		     j = (j + 1) % tid_agg_rx->buf_size) {
621 			if (!tid_agg_rx->reorder_buf[j]) {
622 				skipped++;
623 				continue;
624 			}
625 			if (skipped &&
626 			    !time_after(jiffies, tid_agg_rx->reorder_time[j] +
627 					HT_RX_REORDER_BUF_TIMEOUT))
628 				goto set_release_timer;
629 
630 #ifdef CONFIG_MAC80211_HT_DEBUG
631 			if (net_ratelimit())
632 				wiphy_debug(hw->wiphy,
633 					    "release an RX reorder frame due to timeout on earlier frames\n");
634 #endif
635 			ieee80211_release_reorder_frame(hw, tid_agg_rx, j);
636 
637 			/*
638 			 * Increment the head seq# also for the skipped slots.
639 			 */
640 			tid_agg_rx->head_seq_num =
641 				(tid_agg_rx->head_seq_num + skipped) & SEQ_MASK;
642 			skipped = 0;
643 		}
644 	} else while (tid_agg_rx->reorder_buf[index]) {
645 		ieee80211_release_reorder_frame(hw, tid_agg_rx, index);
646 		index =	seq_sub(tid_agg_rx->head_seq_num, tid_agg_rx->ssn) %
647 							tid_agg_rx->buf_size;
648 	}
649 
650 	if (tid_agg_rx->stored_mpdu_num) {
651 		j = index = seq_sub(tid_agg_rx->head_seq_num,
652 				    tid_agg_rx->ssn) % tid_agg_rx->buf_size;
653 
654 		for (; j != (index - 1) % tid_agg_rx->buf_size;
655 		     j = (j + 1) % tid_agg_rx->buf_size) {
656 			if (tid_agg_rx->reorder_buf[j])
657 				break;
658 		}
659 
660  set_release_timer:
661 
662 		mod_timer(&tid_agg_rx->reorder_timer,
663 			  tid_agg_rx->reorder_time[j] + 1 +
664 			  HT_RX_REORDER_BUF_TIMEOUT);
665 	} else {
666 		del_timer(&tid_agg_rx->reorder_timer);
667 	}
668 }
669 
670 /*
671  * As this function belongs to the RX path it must be under
672  * rcu_read_lock protection. It returns false if the frame
673  * can be processed immediately, true if it was consumed.
674  */
675 static bool ieee80211_sta_manage_reorder_buf(struct ieee80211_hw *hw,
676 					     struct tid_ampdu_rx *tid_agg_rx,
677 					     struct sk_buff *skb)
678 {
679 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
680 	u16 sc = le16_to_cpu(hdr->seq_ctrl);
681 	u16 mpdu_seq_num = (sc & IEEE80211_SCTL_SEQ) >> 4;
682 	u16 head_seq_num, buf_size;
683 	int index;
684 	bool ret = true;
685 
686 	spin_lock(&tid_agg_rx->reorder_lock);
687 
688 	buf_size = tid_agg_rx->buf_size;
689 	head_seq_num = tid_agg_rx->head_seq_num;
690 
691 	/* frame with out of date sequence number */
692 	if (seq_less(mpdu_seq_num, head_seq_num)) {
693 		dev_kfree_skb(skb);
694 		goto out;
695 	}
696 
697 	/*
698 	 * If frame the sequence number exceeds our buffering window
699 	 * size release some previous frames to make room for this one.
700 	 */
701 	if (!seq_less(mpdu_seq_num, head_seq_num + buf_size)) {
702 		head_seq_num = seq_inc(seq_sub(mpdu_seq_num, buf_size));
703 		/* release stored frames up to new head to stack */
704 		ieee80211_release_reorder_frames(hw, tid_agg_rx, head_seq_num);
705 	}
706 
707 	/* Now the new frame is always in the range of the reordering buffer */
708 
709 	index = seq_sub(mpdu_seq_num, tid_agg_rx->ssn) % tid_agg_rx->buf_size;
710 
711 	/* check if we already stored this frame */
712 	if (tid_agg_rx->reorder_buf[index]) {
713 		dev_kfree_skb(skb);
714 		goto out;
715 	}
716 
717 	/*
718 	 * If the current MPDU is in the right order and nothing else
719 	 * is stored we can process it directly, no need to buffer it.
720 	 * If it is first but there's something stored, we may be able
721 	 * to release frames after this one.
722 	 */
723 	if (mpdu_seq_num == tid_agg_rx->head_seq_num &&
724 	    tid_agg_rx->stored_mpdu_num == 0) {
725 		tid_agg_rx->head_seq_num = seq_inc(tid_agg_rx->head_seq_num);
726 		ret = false;
727 		goto out;
728 	}
729 
730 	/* put the frame in the reordering buffer */
731 	tid_agg_rx->reorder_buf[index] = skb;
732 	tid_agg_rx->reorder_time[index] = jiffies;
733 	tid_agg_rx->stored_mpdu_num++;
734 	ieee80211_sta_reorder_release(hw, tid_agg_rx);
735 
736  out:
737 	spin_unlock(&tid_agg_rx->reorder_lock);
738 	return ret;
739 }
740 
741 /*
742  * Reorder MPDUs from A-MPDUs, keeping them on a buffer. Returns
743  * true if the MPDU was buffered, false if it should be processed.
744  */
745 static void ieee80211_rx_reorder_ampdu(struct ieee80211_rx_data *rx)
746 {
747 	struct sk_buff *skb = rx->skb;
748 	struct ieee80211_local *local = rx->local;
749 	struct ieee80211_hw *hw = &local->hw;
750 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
751 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
752 	struct sta_info *sta = rx->sta;
753 	struct tid_ampdu_rx *tid_agg_rx;
754 	u16 sc;
755 	u8 tid, ack_policy;
756 
757 	if (!ieee80211_is_data_qos(hdr->frame_control))
758 		goto dont_reorder;
759 
760 	/*
761 	 * filter the QoS data rx stream according to
762 	 * STA/TID and check if this STA/TID is on aggregation
763 	 */
764 
765 	if (!sta)
766 		goto dont_reorder;
767 
768 	ack_policy = *ieee80211_get_qos_ctl(hdr) &
769 		     IEEE80211_QOS_CTL_ACK_POLICY_MASK;
770 	tid = *ieee80211_get_qos_ctl(hdr) & IEEE80211_QOS_CTL_TID_MASK;
771 
772 	tid_agg_rx = rcu_dereference(sta->ampdu_mlme.tid_rx[tid]);
773 	if (!tid_agg_rx)
774 		goto dont_reorder;
775 
776 	/* qos null data frames are excluded */
777 	if (unlikely(hdr->frame_control & cpu_to_le16(IEEE80211_STYPE_NULLFUNC)))
778 		goto dont_reorder;
779 
780 	/* not part of a BA session */
781 	if (ack_policy != IEEE80211_QOS_CTL_ACK_POLICY_BLOCKACK &&
782 	    ack_policy != IEEE80211_QOS_CTL_ACK_POLICY_NORMAL)
783 		goto dont_reorder;
784 
785 	/* not actually part of this BA session */
786 	if (!(status->rx_flags & IEEE80211_RX_RA_MATCH))
787 		goto dont_reorder;
788 
789 	/* new, potentially un-ordered, ampdu frame - process it */
790 
791 	/* reset session timer */
792 	if (tid_agg_rx->timeout)
793 		mod_timer(&tid_agg_rx->session_timer,
794 			  TU_TO_EXP_TIME(tid_agg_rx->timeout));
795 
796 	/* if this mpdu is fragmented - terminate rx aggregation session */
797 	sc = le16_to_cpu(hdr->seq_ctrl);
798 	if (sc & IEEE80211_SCTL_FRAG) {
799 		skb->pkt_type = IEEE80211_SDATA_QUEUE_TYPE_FRAME;
800 		skb_queue_tail(&rx->sdata->skb_queue, skb);
801 		ieee80211_queue_work(&local->hw, &rx->sdata->work);
802 		return;
803 	}
804 
805 	/*
806 	 * No locking needed -- we will only ever process one
807 	 * RX packet at a time, and thus own tid_agg_rx. All
808 	 * other code manipulating it needs to (and does) make
809 	 * sure that we cannot get to it any more before doing
810 	 * anything with it.
811 	 */
812 	if (ieee80211_sta_manage_reorder_buf(hw, tid_agg_rx, skb))
813 		return;
814 
815  dont_reorder:
816 	skb_queue_tail(&local->rx_skb_queue, skb);
817 }
818 
819 static ieee80211_rx_result debug_noinline
820 ieee80211_rx_h_check(struct ieee80211_rx_data *rx)
821 {
822 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
823 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
824 
825 	/* Drop duplicate 802.11 retransmissions (IEEE 802.11 Chap. 9.2.9) */
826 	if (rx->sta && !is_multicast_ether_addr(hdr->addr1)) {
827 		if (unlikely(ieee80211_has_retry(hdr->frame_control) &&
828 			     rx->sta->last_seq_ctrl[rx->seqno_idx] ==
829 			     hdr->seq_ctrl)) {
830 			if (status->rx_flags & IEEE80211_RX_RA_MATCH) {
831 				rx->local->dot11FrameDuplicateCount++;
832 				rx->sta->num_duplicates++;
833 			}
834 			return RX_DROP_UNUSABLE;
835 		} else
836 			rx->sta->last_seq_ctrl[rx->seqno_idx] = hdr->seq_ctrl;
837 	}
838 
839 	if (unlikely(rx->skb->len < 16)) {
840 		I802_DEBUG_INC(rx->local->rx_handlers_drop_short);
841 		return RX_DROP_MONITOR;
842 	}
843 
844 	/* Drop disallowed frame classes based on STA auth/assoc state;
845 	 * IEEE 802.11, Chap 5.5.
846 	 *
847 	 * mac80211 filters only based on association state, i.e. it drops
848 	 * Class 3 frames from not associated stations. hostapd sends
849 	 * deauth/disassoc frames when needed. In addition, hostapd is
850 	 * responsible for filtering on both auth and assoc states.
851 	 */
852 
853 	if (ieee80211_vif_is_mesh(&rx->sdata->vif))
854 		return ieee80211_rx_mesh_check(rx);
855 
856 	if (unlikely((ieee80211_is_data(hdr->frame_control) ||
857 		      ieee80211_is_pspoll(hdr->frame_control)) &&
858 		     rx->sdata->vif.type != NL80211_IFTYPE_ADHOC &&
859 		     rx->sdata->vif.type != NL80211_IFTYPE_WDS &&
860 		     (!rx->sta || !test_sta_flag(rx->sta, WLAN_STA_ASSOC)))) {
861 		if (rx->sta && rx->sta->dummy &&
862 		    ieee80211_is_data_present(hdr->frame_control)) {
863 			u16 ethertype;
864 			u8 *payload;
865 
866 			payload = rx->skb->data +
867 				ieee80211_hdrlen(hdr->frame_control);
868 			ethertype = (payload[6] << 8) | payload[7];
869 			if (cpu_to_be16(ethertype) ==
870 			    rx->sdata->control_port_protocol)
871 				return RX_CONTINUE;
872 		}
873 
874 		if (rx->sdata->vif.type == NL80211_IFTYPE_AP &&
875 		    cfg80211_rx_spurious_frame(rx->sdata->dev,
876 					       hdr->addr2,
877 					       GFP_ATOMIC))
878 			return RX_DROP_UNUSABLE;
879 
880 		return RX_DROP_MONITOR;
881 	}
882 
883 	return RX_CONTINUE;
884 }
885 
886 
887 static ieee80211_rx_result debug_noinline
888 ieee80211_rx_h_decrypt(struct ieee80211_rx_data *rx)
889 {
890 	struct sk_buff *skb = rx->skb;
891 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
892 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
893 	int keyidx;
894 	int hdrlen;
895 	ieee80211_rx_result result = RX_DROP_UNUSABLE;
896 	struct ieee80211_key *sta_ptk = NULL;
897 	int mmie_keyidx = -1;
898 	__le16 fc;
899 
900 	/*
901 	 * Key selection 101
902 	 *
903 	 * There are four types of keys:
904 	 *  - GTK (group keys)
905 	 *  - IGTK (group keys for management frames)
906 	 *  - PTK (pairwise keys)
907 	 *  - STK (station-to-station pairwise keys)
908 	 *
909 	 * When selecting a key, we have to distinguish between multicast
910 	 * (including broadcast) and unicast frames, the latter can only
911 	 * use PTKs and STKs while the former always use GTKs and IGTKs.
912 	 * Unless, of course, actual WEP keys ("pre-RSNA") are used, then
913 	 * unicast frames can also use key indices like GTKs. Hence, if we
914 	 * don't have a PTK/STK we check the key index for a WEP key.
915 	 *
916 	 * Note that in a regular BSS, multicast frames are sent by the
917 	 * AP only, associated stations unicast the frame to the AP first
918 	 * which then multicasts it on their behalf.
919 	 *
920 	 * There is also a slight problem in IBSS mode: GTKs are negotiated
921 	 * with each station, that is something we don't currently handle.
922 	 * The spec seems to expect that one negotiates the same key with
923 	 * every station but there's no such requirement; VLANs could be
924 	 * possible.
925 	 */
926 
927 	/*
928 	 * No point in finding a key and decrypting if the frame is neither
929 	 * addressed to us nor a multicast frame.
930 	 */
931 	if (!(status->rx_flags & IEEE80211_RX_RA_MATCH))
932 		return RX_CONTINUE;
933 
934 	/* start without a key */
935 	rx->key = NULL;
936 
937 	if (rx->sta)
938 		sta_ptk = rcu_dereference(rx->sta->ptk);
939 
940 	fc = hdr->frame_control;
941 
942 	if (!ieee80211_has_protected(fc))
943 		mmie_keyidx = ieee80211_get_mmie_keyidx(rx->skb);
944 
945 	if (!is_multicast_ether_addr(hdr->addr1) && sta_ptk) {
946 		rx->key = sta_ptk;
947 		if ((status->flag & RX_FLAG_DECRYPTED) &&
948 		    (status->flag & RX_FLAG_IV_STRIPPED))
949 			return RX_CONTINUE;
950 		/* Skip decryption if the frame is not protected. */
951 		if (!ieee80211_has_protected(fc))
952 			return RX_CONTINUE;
953 	} else if (mmie_keyidx >= 0) {
954 		/* Broadcast/multicast robust management frame / BIP */
955 		if ((status->flag & RX_FLAG_DECRYPTED) &&
956 		    (status->flag & RX_FLAG_IV_STRIPPED))
957 			return RX_CONTINUE;
958 
959 		if (mmie_keyidx < NUM_DEFAULT_KEYS ||
960 		    mmie_keyidx >= NUM_DEFAULT_KEYS + NUM_DEFAULT_MGMT_KEYS)
961 			return RX_DROP_MONITOR; /* unexpected BIP keyidx */
962 		if (rx->sta)
963 			rx->key = rcu_dereference(rx->sta->gtk[mmie_keyidx]);
964 		if (!rx->key)
965 			rx->key = rcu_dereference(rx->sdata->keys[mmie_keyidx]);
966 	} else if (!ieee80211_has_protected(fc)) {
967 		/*
968 		 * The frame was not protected, so skip decryption. However, we
969 		 * need to set rx->key if there is a key that could have been
970 		 * used so that the frame may be dropped if encryption would
971 		 * have been expected.
972 		 */
973 		struct ieee80211_key *key = NULL;
974 		struct ieee80211_sub_if_data *sdata = rx->sdata;
975 		int i;
976 
977 		if (ieee80211_is_mgmt(fc) &&
978 		    is_multicast_ether_addr(hdr->addr1) &&
979 		    (key = rcu_dereference(rx->sdata->default_mgmt_key)))
980 			rx->key = key;
981 		else {
982 			if (rx->sta) {
983 				for (i = 0; i < NUM_DEFAULT_KEYS; i++) {
984 					key = rcu_dereference(rx->sta->gtk[i]);
985 					if (key)
986 						break;
987 				}
988 			}
989 			if (!key) {
990 				for (i = 0; i < NUM_DEFAULT_KEYS; i++) {
991 					key = rcu_dereference(sdata->keys[i]);
992 					if (key)
993 						break;
994 				}
995 			}
996 			if (key)
997 				rx->key = key;
998 		}
999 		return RX_CONTINUE;
1000 	} else {
1001 		u8 keyid;
1002 		/*
1003 		 * The device doesn't give us the IV so we won't be
1004 		 * able to look up the key. That's ok though, we
1005 		 * don't need to decrypt the frame, we just won't
1006 		 * be able to keep statistics accurate.
1007 		 * Except for key threshold notifications, should
1008 		 * we somehow allow the driver to tell us which key
1009 		 * the hardware used if this flag is set?
1010 		 */
1011 		if ((status->flag & RX_FLAG_DECRYPTED) &&
1012 		    (status->flag & RX_FLAG_IV_STRIPPED))
1013 			return RX_CONTINUE;
1014 
1015 		hdrlen = ieee80211_hdrlen(fc);
1016 
1017 		if (rx->skb->len < 8 + hdrlen)
1018 			return RX_DROP_UNUSABLE; /* TODO: count this? */
1019 
1020 		/*
1021 		 * no need to call ieee80211_wep_get_keyidx,
1022 		 * it verifies a bunch of things we've done already
1023 		 */
1024 		skb_copy_bits(rx->skb, hdrlen + 3, &keyid, 1);
1025 		keyidx = keyid >> 6;
1026 
1027 		/* check per-station GTK first, if multicast packet */
1028 		if (is_multicast_ether_addr(hdr->addr1) && rx->sta)
1029 			rx->key = rcu_dereference(rx->sta->gtk[keyidx]);
1030 
1031 		/* if not found, try default key */
1032 		if (!rx->key) {
1033 			rx->key = rcu_dereference(rx->sdata->keys[keyidx]);
1034 
1035 			/*
1036 			 * RSNA-protected unicast frames should always be
1037 			 * sent with pairwise or station-to-station keys,
1038 			 * but for WEP we allow using a key index as well.
1039 			 */
1040 			if (rx->key &&
1041 			    rx->key->conf.cipher != WLAN_CIPHER_SUITE_WEP40 &&
1042 			    rx->key->conf.cipher != WLAN_CIPHER_SUITE_WEP104 &&
1043 			    !is_multicast_ether_addr(hdr->addr1))
1044 				rx->key = NULL;
1045 		}
1046 	}
1047 
1048 	if (rx->key) {
1049 		if (unlikely(rx->key->flags & KEY_FLAG_TAINTED))
1050 			return RX_DROP_MONITOR;
1051 
1052 		rx->key->tx_rx_count++;
1053 		/* TODO: add threshold stuff again */
1054 	} else {
1055 		return RX_DROP_MONITOR;
1056 	}
1057 
1058 	if (skb_linearize(rx->skb))
1059 		return RX_DROP_UNUSABLE;
1060 	/* the hdr variable is invalid now! */
1061 
1062 	switch (rx->key->conf.cipher) {
1063 	case WLAN_CIPHER_SUITE_WEP40:
1064 	case WLAN_CIPHER_SUITE_WEP104:
1065 		/* Check for weak IVs if possible */
1066 		if (rx->sta && ieee80211_is_data(fc) &&
1067 		    (!(status->flag & RX_FLAG_IV_STRIPPED) ||
1068 		     !(status->flag & RX_FLAG_DECRYPTED)) &&
1069 		    ieee80211_wep_is_weak_iv(rx->skb, rx->key))
1070 			rx->sta->wep_weak_iv_count++;
1071 
1072 		result = ieee80211_crypto_wep_decrypt(rx);
1073 		break;
1074 	case WLAN_CIPHER_SUITE_TKIP:
1075 		result = ieee80211_crypto_tkip_decrypt(rx);
1076 		break;
1077 	case WLAN_CIPHER_SUITE_CCMP:
1078 		result = ieee80211_crypto_ccmp_decrypt(rx);
1079 		break;
1080 	case WLAN_CIPHER_SUITE_AES_CMAC:
1081 		result = ieee80211_crypto_aes_cmac_decrypt(rx);
1082 		break;
1083 	default:
1084 		/*
1085 		 * We can reach here only with HW-only algorithms
1086 		 * but why didn't it decrypt the frame?!
1087 		 */
1088 		return RX_DROP_UNUSABLE;
1089 	}
1090 
1091 	/* either the frame has been decrypted or will be dropped */
1092 	status->flag |= RX_FLAG_DECRYPTED;
1093 
1094 	return result;
1095 }
1096 
1097 static ieee80211_rx_result debug_noinline
1098 ieee80211_rx_h_check_more_data(struct ieee80211_rx_data *rx)
1099 {
1100 	struct ieee80211_local *local;
1101 	struct ieee80211_hdr *hdr;
1102 	struct sk_buff *skb;
1103 
1104 	local = rx->local;
1105 	skb = rx->skb;
1106 	hdr = (struct ieee80211_hdr *) skb->data;
1107 
1108 	if (!local->pspolling)
1109 		return RX_CONTINUE;
1110 
1111 	if (!ieee80211_has_fromds(hdr->frame_control))
1112 		/* this is not from AP */
1113 		return RX_CONTINUE;
1114 
1115 	if (!ieee80211_is_data(hdr->frame_control))
1116 		return RX_CONTINUE;
1117 
1118 	if (!ieee80211_has_moredata(hdr->frame_control)) {
1119 		/* AP has no more frames buffered for us */
1120 		local->pspolling = false;
1121 		return RX_CONTINUE;
1122 	}
1123 
1124 	/* more data bit is set, let's request a new frame from the AP */
1125 	ieee80211_send_pspoll(local, rx->sdata);
1126 
1127 	return RX_CONTINUE;
1128 }
1129 
1130 static void ap_sta_ps_start(struct sta_info *sta)
1131 {
1132 	struct ieee80211_sub_if_data *sdata = sta->sdata;
1133 	struct ieee80211_local *local = sdata->local;
1134 
1135 	atomic_inc(&sdata->bss->num_sta_ps);
1136 	set_sta_flag(sta, WLAN_STA_PS_STA);
1137 	if (!(local->hw.flags & IEEE80211_HW_AP_LINK_PS))
1138 		drv_sta_notify(local, sdata, STA_NOTIFY_SLEEP, &sta->sta);
1139 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
1140 	printk(KERN_DEBUG "%s: STA %pM aid %d enters power save mode\n",
1141 	       sdata->name, sta->sta.addr, sta->sta.aid);
1142 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
1143 }
1144 
1145 static void ap_sta_ps_end(struct sta_info *sta)
1146 {
1147 	struct ieee80211_sub_if_data *sdata = sta->sdata;
1148 
1149 	atomic_dec(&sdata->bss->num_sta_ps);
1150 
1151 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
1152 	printk(KERN_DEBUG "%s: STA %pM aid %d exits power save mode\n",
1153 	       sdata->name, sta->sta.addr, sta->sta.aid);
1154 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
1155 
1156 	if (test_sta_flag(sta, WLAN_STA_PS_DRIVER)) {
1157 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
1158 		printk(KERN_DEBUG "%s: STA %pM aid %d driver-ps-blocked\n",
1159 		       sdata->name, sta->sta.addr, sta->sta.aid);
1160 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
1161 		return;
1162 	}
1163 
1164 	ieee80211_sta_ps_deliver_wakeup(sta);
1165 }
1166 
1167 int ieee80211_sta_ps_transition(struct ieee80211_sta *sta, bool start)
1168 {
1169 	struct sta_info *sta_inf = container_of(sta, struct sta_info, sta);
1170 	bool in_ps;
1171 
1172 	WARN_ON(!(sta_inf->local->hw.flags & IEEE80211_HW_AP_LINK_PS));
1173 
1174 	/* Don't let the same PS state be set twice */
1175 	in_ps = test_sta_flag(sta_inf, WLAN_STA_PS_STA);
1176 	if ((start && in_ps) || (!start && !in_ps))
1177 		return -EINVAL;
1178 
1179 	if (start)
1180 		ap_sta_ps_start(sta_inf);
1181 	else
1182 		ap_sta_ps_end(sta_inf);
1183 
1184 	return 0;
1185 }
1186 EXPORT_SYMBOL(ieee80211_sta_ps_transition);
1187 
1188 static ieee80211_rx_result debug_noinline
1189 ieee80211_rx_h_uapsd_and_pspoll(struct ieee80211_rx_data *rx)
1190 {
1191 	struct ieee80211_sub_if_data *sdata = rx->sdata;
1192 	struct ieee80211_hdr *hdr = (void *)rx->skb->data;
1193 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
1194 	int tid, ac;
1195 
1196 	if (!rx->sta || !(status->rx_flags & IEEE80211_RX_RA_MATCH))
1197 		return RX_CONTINUE;
1198 
1199 	if (sdata->vif.type != NL80211_IFTYPE_AP &&
1200 	    sdata->vif.type != NL80211_IFTYPE_AP_VLAN)
1201 		return RX_CONTINUE;
1202 
1203 	/*
1204 	 * The device handles station powersave, so don't do anything about
1205 	 * uAPSD and PS-Poll frames (the latter shouldn't even come up from
1206 	 * it to mac80211 since they're handled.)
1207 	 */
1208 	if (sdata->local->hw.flags & IEEE80211_HW_AP_LINK_PS)
1209 		return RX_CONTINUE;
1210 
1211 	/*
1212 	 * Don't do anything if the station isn't already asleep. In
1213 	 * the uAPSD case, the station will probably be marked asleep,
1214 	 * in the PS-Poll case the station must be confused ...
1215 	 */
1216 	if (!test_sta_flag(rx->sta, WLAN_STA_PS_STA))
1217 		return RX_CONTINUE;
1218 
1219 	if (unlikely(ieee80211_is_pspoll(hdr->frame_control))) {
1220 		if (!test_sta_flag(rx->sta, WLAN_STA_SP)) {
1221 			if (!test_sta_flag(rx->sta, WLAN_STA_PS_DRIVER))
1222 				ieee80211_sta_ps_deliver_poll_response(rx->sta);
1223 			else
1224 				set_sta_flag(rx->sta, WLAN_STA_PSPOLL);
1225 		}
1226 
1227 		/* Free PS Poll skb here instead of returning RX_DROP that would
1228 		 * count as an dropped frame. */
1229 		dev_kfree_skb(rx->skb);
1230 
1231 		return RX_QUEUED;
1232 	} else if (!ieee80211_has_morefrags(hdr->frame_control) &&
1233 		   !(status->rx_flags & IEEE80211_RX_DEFERRED_RELEASE) &&
1234 		   ieee80211_has_pm(hdr->frame_control) &&
1235 		   (ieee80211_is_data_qos(hdr->frame_control) ||
1236 		    ieee80211_is_qos_nullfunc(hdr->frame_control))) {
1237 		tid = *ieee80211_get_qos_ctl(hdr) & IEEE80211_QOS_CTL_TID_MASK;
1238 		ac = ieee802_1d_to_ac[tid & 7];
1239 
1240 		/*
1241 		 * If this AC is not trigger-enabled do nothing.
1242 		 *
1243 		 * NB: This could/should check a separate bitmap of trigger-
1244 		 * enabled queues, but for now we only implement uAPSD w/o
1245 		 * TSPEC changes to the ACs, so they're always the same.
1246 		 */
1247 		if (!(rx->sta->sta.uapsd_queues & BIT(ac)))
1248 			return RX_CONTINUE;
1249 
1250 		/* if we are in a service period, do nothing */
1251 		if (test_sta_flag(rx->sta, WLAN_STA_SP))
1252 			return RX_CONTINUE;
1253 
1254 		if (!test_sta_flag(rx->sta, WLAN_STA_PS_DRIVER))
1255 			ieee80211_sta_ps_deliver_uapsd(rx->sta);
1256 		else
1257 			set_sta_flag(rx->sta, WLAN_STA_UAPSD);
1258 	}
1259 
1260 	return RX_CONTINUE;
1261 }
1262 
1263 static ieee80211_rx_result debug_noinline
1264 ieee80211_rx_h_sta_process(struct ieee80211_rx_data *rx)
1265 {
1266 	struct sta_info *sta = rx->sta;
1267 	struct sk_buff *skb = rx->skb;
1268 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
1269 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
1270 
1271 	if (!sta)
1272 		return RX_CONTINUE;
1273 
1274 	/*
1275 	 * Update last_rx only for IBSS packets which are for the current
1276 	 * BSSID to avoid keeping the current IBSS network alive in cases
1277 	 * where other STAs start using different BSSID.
1278 	 */
1279 	if (rx->sdata->vif.type == NL80211_IFTYPE_ADHOC) {
1280 		u8 *bssid = ieee80211_get_bssid(hdr, rx->skb->len,
1281 						NL80211_IFTYPE_ADHOC);
1282 		if (compare_ether_addr(bssid, rx->sdata->u.ibss.bssid) == 0) {
1283 			sta->last_rx = jiffies;
1284 			if (ieee80211_is_data(hdr->frame_control)) {
1285 				sta->last_rx_rate_idx = status->rate_idx;
1286 				sta->last_rx_rate_flag = status->flag;
1287 			}
1288 		}
1289 	} else if (!is_multicast_ether_addr(hdr->addr1)) {
1290 		/*
1291 		 * Mesh beacons will update last_rx when if they are found to
1292 		 * match the current local configuration when processed.
1293 		 */
1294 		sta->last_rx = jiffies;
1295 		if (ieee80211_is_data(hdr->frame_control)) {
1296 			sta->last_rx_rate_idx = status->rate_idx;
1297 			sta->last_rx_rate_flag = status->flag;
1298 		}
1299 	}
1300 
1301 	if (!(status->rx_flags & IEEE80211_RX_RA_MATCH))
1302 		return RX_CONTINUE;
1303 
1304 	if (rx->sdata->vif.type == NL80211_IFTYPE_STATION)
1305 		ieee80211_sta_rx_notify(rx->sdata, hdr);
1306 
1307 	sta->rx_fragments++;
1308 	sta->rx_bytes += rx->skb->len;
1309 	sta->last_signal = status->signal;
1310 	ewma_add(&sta->avg_signal, -status->signal);
1311 
1312 	/*
1313 	 * Change STA power saving mode only at the end of a frame
1314 	 * exchange sequence.
1315 	 */
1316 	if (!(sta->local->hw.flags & IEEE80211_HW_AP_LINK_PS) &&
1317 	    !ieee80211_has_morefrags(hdr->frame_control) &&
1318 	    !(status->rx_flags & IEEE80211_RX_DEFERRED_RELEASE) &&
1319 	    (rx->sdata->vif.type == NL80211_IFTYPE_AP ||
1320 	     rx->sdata->vif.type == NL80211_IFTYPE_AP_VLAN)) {
1321 		if (test_sta_flag(sta, WLAN_STA_PS_STA)) {
1322 			/*
1323 			 * Ignore doze->wake transitions that are
1324 			 * indicated by non-data frames, the standard
1325 			 * is unclear here, but for example going to
1326 			 * PS mode and then scanning would cause a
1327 			 * doze->wake transition for the probe request,
1328 			 * and that is clearly undesirable.
1329 			 */
1330 			if (ieee80211_is_data(hdr->frame_control) &&
1331 			    !ieee80211_has_pm(hdr->frame_control))
1332 				ap_sta_ps_end(sta);
1333 		} else {
1334 			if (ieee80211_has_pm(hdr->frame_control))
1335 				ap_sta_ps_start(sta);
1336 		}
1337 	}
1338 
1339 	/*
1340 	 * Drop (qos-)data::nullfunc frames silently, since they
1341 	 * are used only to control station power saving mode.
1342 	 */
1343 	if (ieee80211_is_nullfunc(hdr->frame_control) ||
1344 	    ieee80211_is_qos_nullfunc(hdr->frame_control)) {
1345 		I802_DEBUG_INC(rx->local->rx_handlers_drop_nullfunc);
1346 
1347 		/*
1348 		 * If we receive a 4-addr nullfunc frame from a STA
1349 		 * that was not moved to a 4-addr STA vlan yet send
1350 		 * the event to userspace and for older hostapd drop
1351 		 * the frame to the monitor interface.
1352 		 */
1353 		if (ieee80211_has_a4(hdr->frame_control) &&
1354 		    (rx->sdata->vif.type == NL80211_IFTYPE_AP ||
1355 		     (rx->sdata->vif.type == NL80211_IFTYPE_AP_VLAN &&
1356 		      !rx->sdata->u.vlan.sta))) {
1357 			if (!test_and_set_sta_flag(sta, WLAN_STA_4ADDR_EVENT))
1358 				cfg80211_rx_unexpected_4addr_frame(
1359 					rx->sdata->dev, sta->sta.addr,
1360 					GFP_ATOMIC);
1361 			return RX_DROP_MONITOR;
1362 		}
1363 		/*
1364 		 * Update counter and free packet here to avoid
1365 		 * counting this as a dropped packed.
1366 		 */
1367 		sta->rx_packets++;
1368 		dev_kfree_skb(rx->skb);
1369 		return RX_QUEUED;
1370 	}
1371 
1372 	return RX_CONTINUE;
1373 } /* ieee80211_rx_h_sta_process */
1374 
1375 static inline struct ieee80211_fragment_entry *
1376 ieee80211_reassemble_add(struct ieee80211_sub_if_data *sdata,
1377 			 unsigned int frag, unsigned int seq, int rx_queue,
1378 			 struct sk_buff **skb)
1379 {
1380 	struct ieee80211_fragment_entry *entry;
1381 	int idx;
1382 
1383 	idx = sdata->fragment_next;
1384 	entry = &sdata->fragments[sdata->fragment_next++];
1385 	if (sdata->fragment_next >= IEEE80211_FRAGMENT_MAX)
1386 		sdata->fragment_next = 0;
1387 
1388 	if (!skb_queue_empty(&entry->skb_list)) {
1389 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG
1390 		struct ieee80211_hdr *hdr =
1391 			(struct ieee80211_hdr *) entry->skb_list.next->data;
1392 		printk(KERN_DEBUG "%s: RX reassembly removed oldest "
1393 		       "fragment entry (idx=%d age=%lu seq=%d last_frag=%d "
1394 		       "addr1=%pM addr2=%pM\n",
1395 		       sdata->name, idx,
1396 		       jiffies - entry->first_frag_time, entry->seq,
1397 		       entry->last_frag, hdr->addr1, hdr->addr2);
1398 #endif
1399 		__skb_queue_purge(&entry->skb_list);
1400 	}
1401 
1402 	__skb_queue_tail(&entry->skb_list, *skb); /* no need for locking */
1403 	*skb = NULL;
1404 	entry->first_frag_time = jiffies;
1405 	entry->seq = seq;
1406 	entry->rx_queue = rx_queue;
1407 	entry->last_frag = frag;
1408 	entry->ccmp = 0;
1409 	entry->extra_len = 0;
1410 
1411 	return entry;
1412 }
1413 
1414 static inline struct ieee80211_fragment_entry *
1415 ieee80211_reassemble_find(struct ieee80211_sub_if_data *sdata,
1416 			  unsigned int frag, unsigned int seq,
1417 			  int rx_queue, struct ieee80211_hdr *hdr)
1418 {
1419 	struct ieee80211_fragment_entry *entry;
1420 	int i, idx;
1421 
1422 	idx = sdata->fragment_next;
1423 	for (i = 0; i < IEEE80211_FRAGMENT_MAX; i++) {
1424 		struct ieee80211_hdr *f_hdr;
1425 
1426 		idx--;
1427 		if (idx < 0)
1428 			idx = IEEE80211_FRAGMENT_MAX - 1;
1429 
1430 		entry = &sdata->fragments[idx];
1431 		if (skb_queue_empty(&entry->skb_list) || entry->seq != seq ||
1432 		    entry->rx_queue != rx_queue ||
1433 		    entry->last_frag + 1 != frag)
1434 			continue;
1435 
1436 		f_hdr = (struct ieee80211_hdr *)entry->skb_list.next->data;
1437 
1438 		/*
1439 		 * Check ftype and addresses are equal, else check next fragment
1440 		 */
1441 		if (((hdr->frame_control ^ f_hdr->frame_control) &
1442 		     cpu_to_le16(IEEE80211_FCTL_FTYPE)) ||
1443 		    compare_ether_addr(hdr->addr1, f_hdr->addr1) != 0 ||
1444 		    compare_ether_addr(hdr->addr2, f_hdr->addr2) != 0)
1445 			continue;
1446 
1447 		if (time_after(jiffies, entry->first_frag_time + 2 * HZ)) {
1448 			__skb_queue_purge(&entry->skb_list);
1449 			continue;
1450 		}
1451 		return entry;
1452 	}
1453 
1454 	return NULL;
1455 }
1456 
1457 static ieee80211_rx_result debug_noinline
1458 ieee80211_rx_h_defragment(struct ieee80211_rx_data *rx)
1459 {
1460 	struct ieee80211_hdr *hdr;
1461 	u16 sc;
1462 	__le16 fc;
1463 	unsigned int frag, seq;
1464 	struct ieee80211_fragment_entry *entry;
1465 	struct sk_buff *skb;
1466 	struct ieee80211_rx_status *status;
1467 
1468 	hdr = (struct ieee80211_hdr *)rx->skb->data;
1469 	fc = hdr->frame_control;
1470 	sc = le16_to_cpu(hdr->seq_ctrl);
1471 	frag = sc & IEEE80211_SCTL_FRAG;
1472 
1473 	if (likely((!ieee80211_has_morefrags(fc) && frag == 0) ||
1474 		   (rx->skb)->len < 24 ||
1475 		   is_multicast_ether_addr(hdr->addr1))) {
1476 		/* not fragmented */
1477 		goto out;
1478 	}
1479 	I802_DEBUG_INC(rx->local->rx_handlers_fragments);
1480 
1481 	if (skb_linearize(rx->skb))
1482 		return RX_DROP_UNUSABLE;
1483 
1484 	/*
1485 	 *  skb_linearize() might change the skb->data and
1486 	 *  previously cached variables (in this case, hdr) need to
1487 	 *  be refreshed with the new data.
1488 	 */
1489 	hdr = (struct ieee80211_hdr *)rx->skb->data;
1490 	seq = (sc & IEEE80211_SCTL_SEQ) >> 4;
1491 
1492 	if (frag == 0) {
1493 		/* This is the first fragment of a new frame. */
1494 		entry = ieee80211_reassemble_add(rx->sdata, frag, seq,
1495 						 rx->seqno_idx, &(rx->skb));
1496 		if (rx->key && rx->key->conf.cipher == WLAN_CIPHER_SUITE_CCMP &&
1497 		    ieee80211_has_protected(fc)) {
1498 			int queue = rx->security_idx;
1499 			/* Store CCMP PN so that we can verify that the next
1500 			 * fragment has a sequential PN value. */
1501 			entry->ccmp = 1;
1502 			memcpy(entry->last_pn,
1503 			       rx->key->u.ccmp.rx_pn[queue],
1504 			       CCMP_PN_LEN);
1505 		}
1506 		return RX_QUEUED;
1507 	}
1508 
1509 	/* This is a fragment for a frame that should already be pending in
1510 	 * fragment cache. Add this fragment to the end of the pending entry.
1511 	 */
1512 	entry = ieee80211_reassemble_find(rx->sdata, frag, seq,
1513 					  rx->seqno_idx, hdr);
1514 	if (!entry) {
1515 		I802_DEBUG_INC(rx->local->rx_handlers_drop_defrag);
1516 		return RX_DROP_MONITOR;
1517 	}
1518 
1519 	/* Verify that MPDUs within one MSDU have sequential PN values.
1520 	 * (IEEE 802.11i, 8.3.3.4.5) */
1521 	if (entry->ccmp) {
1522 		int i;
1523 		u8 pn[CCMP_PN_LEN], *rpn;
1524 		int queue;
1525 		if (!rx->key || rx->key->conf.cipher != WLAN_CIPHER_SUITE_CCMP)
1526 			return RX_DROP_UNUSABLE;
1527 		memcpy(pn, entry->last_pn, CCMP_PN_LEN);
1528 		for (i = CCMP_PN_LEN - 1; i >= 0; i--) {
1529 			pn[i]++;
1530 			if (pn[i])
1531 				break;
1532 		}
1533 		queue = rx->security_idx;
1534 		rpn = rx->key->u.ccmp.rx_pn[queue];
1535 		if (memcmp(pn, rpn, CCMP_PN_LEN))
1536 			return RX_DROP_UNUSABLE;
1537 		memcpy(entry->last_pn, pn, CCMP_PN_LEN);
1538 	}
1539 
1540 	skb_pull(rx->skb, ieee80211_hdrlen(fc));
1541 	__skb_queue_tail(&entry->skb_list, rx->skb);
1542 	entry->last_frag = frag;
1543 	entry->extra_len += rx->skb->len;
1544 	if (ieee80211_has_morefrags(fc)) {
1545 		rx->skb = NULL;
1546 		return RX_QUEUED;
1547 	}
1548 
1549 	rx->skb = __skb_dequeue(&entry->skb_list);
1550 	if (skb_tailroom(rx->skb) < entry->extra_len) {
1551 		I802_DEBUG_INC(rx->local->rx_expand_skb_head2);
1552 		if (unlikely(pskb_expand_head(rx->skb, 0, entry->extra_len,
1553 					      GFP_ATOMIC))) {
1554 			I802_DEBUG_INC(rx->local->rx_handlers_drop_defrag);
1555 			__skb_queue_purge(&entry->skb_list);
1556 			return RX_DROP_UNUSABLE;
1557 		}
1558 	}
1559 	while ((skb = __skb_dequeue(&entry->skb_list))) {
1560 		memcpy(skb_put(rx->skb, skb->len), skb->data, skb->len);
1561 		dev_kfree_skb(skb);
1562 	}
1563 
1564 	/* Complete frame has been reassembled - process it now */
1565 	status = IEEE80211_SKB_RXCB(rx->skb);
1566 	status->rx_flags |= IEEE80211_RX_FRAGMENTED;
1567 
1568  out:
1569 	if (rx->sta)
1570 		rx->sta->rx_packets++;
1571 	if (is_multicast_ether_addr(hdr->addr1))
1572 		rx->local->dot11MulticastReceivedFrameCount++;
1573 	else
1574 		ieee80211_led_rx(rx->local);
1575 	return RX_CONTINUE;
1576 }
1577 
1578 static ieee80211_rx_result debug_noinline
1579 ieee80211_rx_h_remove_qos_control(struct ieee80211_rx_data *rx)
1580 {
1581 	u8 *data = rx->skb->data;
1582 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)data;
1583 
1584 	if (!ieee80211_is_data_qos(hdr->frame_control))
1585 		return RX_CONTINUE;
1586 
1587 	/* remove the qos control field, update frame type and meta-data */
1588 	memmove(data + IEEE80211_QOS_CTL_LEN, data,
1589 		ieee80211_hdrlen(hdr->frame_control) - IEEE80211_QOS_CTL_LEN);
1590 	hdr = (struct ieee80211_hdr *)skb_pull(rx->skb, IEEE80211_QOS_CTL_LEN);
1591 	/* change frame type to non QOS */
1592 	hdr->frame_control &= ~cpu_to_le16(IEEE80211_STYPE_QOS_DATA);
1593 
1594 	return RX_CONTINUE;
1595 }
1596 
1597 static int
1598 ieee80211_802_1x_port_control(struct ieee80211_rx_data *rx)
1599 {
1600 	if (unlikely(!rx->sta ||
1601 	    !test_sta_flag(rx->sta, WLAN_STA_AUTHORIZED)))
1602 		return -EACCES;
1603 
1604 	return 0;
1605 }
1606 
1607 static int
1608 ieee80211_drop_unencrypted(struct ieee80211_rx_data *rx, __le16 fc)
1609 {
1610 	struct sk_buff *skb = rx->skb;
1611 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
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 	/* Drop unencrypted frames if key is set. */
1621 	if (unlikely(!ieee80211_has_protected(fc) &&
1622 		     !ieee80211_is_nullfunc(fc) &&
1623 		     ieee80211_is_data(fc) &&
1624 		     (rx->key || rx->sdata->drop_unencrypted)))
1625 		return -EACCES;
1626 
1627 	return 0;
1628 }
1629 
1630 static int
1631 ieee80211_drop_unencrypted_mgmt(struct ieee80211_rx_data *rx)
1632 {
1633 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
1634 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
1635 	__le16 fc = hdr->frame_control;
1636 
1637 	/*
1638 	 * Pass through unencrypted frames if the hardware has
1639 	 * decrypted them already.
1640 	 */
1641 	if (status->flag & RX_FLAG_DECRYPTED)
1642 		return 0;
1643 
1644 	if (rx->sta && test_sta_flag(rx->sta, WLAN_STA_MFP)) {
1645 		if (unlikely(!ieee80211_has_protected(fc) &&
1646 			     ieee80211_is_unicast_robust_mgmt_frame(rx->skb) &&
1647 			     rx->key)) {
1648 			if (ieee80211_is_deauth(fc))
1649 				cfg80211_send_unprot_deauth(rx->sdata->dev,
1650 							    rx->skb->data,
1651 							    rx->skb->len);
1652 			else if (ieee80211_is_disassoc(fc))
1653 				cfg80211_send_unprot_disassoc(rx->sdata->dev,
1654 							      rx->skb->data,
1655 							      rx->skb->len);
1656 			return -EACCES;
1657 		}
1658 		/* BIP does not use Protected field, so need to check MMIE */
1659 		if (unlikely(ieee80211_is_multicast_robust_mgmt_frame(rx->skb) &&
1660 			     ieee80211_get_mmie_keyidx(rx->skb) < 0)) {
1661 			if (ieee80211_is_deauth(fc))
1662 				cfg80211_send_unprot_deauth(rx->sdata->dev,
1663 							    rx->skb->data,
1664 							    rx->skb->len);
1665 			else if (ieee80211_is_disassoc(fc))
1666 				cfg80211_send_unprot_disassoc(rx->sdata->dev,
1667 							      rx->skb->data,
1668 							      rx->skb->len);
1669 			return -EACCES;
1670 		}
1671 		/*
1672 		 * When using MFP, Action frames are not allowed prior to
1673 		 * having configured keys.
1674 		 */
1675 		if (unlikely(ieee80211_is_action(fc) && !rx->key &&
1676 			     ieee80211_is_robust_mgmt_frame(
1677 				     (struct ieee80211_hdr *) rx->skb->data)))
1678 			return -EACCES;
1679 	}
1680 
1681 	return 0;
1682 }
1683 
1684 static int
1685 __ieee80211_data_to_8023(struct ieee80211_rx_data *rx, bool *port_control)
1686 {
1687 	struct ieee80211_sub_if_data *sdata = rx->sdata;
1688 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
1689 	bool check_port_control = false;
1690 	struct ethhdr *ehdr;
1691 	int ret;
1692 
1693 	*port_control = false;
1694 	if (ieee80211_has_a4(hdr->frame_control) &&
1695 	    sdata->vif.type == NL80211_IFTYPE_AP_VLAN && !sdata->u.vlan.sta)
1696 		return -1;
1697 
1698 	if (sdata->vif.type == NL80211_IFTYPE_STATION &&
1699 	    !!sdata->u.mgd.use_4addr != !!ieee80211_has_a4(hdr->frame_control)) {
1700 
1701 		if (!sdata->u.mgd.use_4addr)
1702 			return -1;
1703 		else
1704 			check_port_control = true;
1705 	}
1706 
1707 	if (is_multicast_ether_addr(hdr->addr1) &&
1708 	    sdata->vif.type == NL80211_IFTYPE_AP_VLAN && sdata->u.vlan.sta)
1709 		return -1;
1710 
1711 	ret = ieee80211_data_to_8023(rx->skb, sdata->vif.addr, sdata->vif.type);
1712 	if (ret < 0)
1713 		return ret;
1714 
1715 	ehdr = (struct ethhdr *) rx->skb->data;
1716 	if (ehdr->h_proto == rx->sdata->control_port_protocol)
1717 		*port_control = true;
1718 	else if (check_port_control)
1719 		return -1;
1720 
1721 	return 0;
1722 }
1723 
1724 /*
1725  * requires that rx->skb is a frame with ethernet header
1726  */
1727 static bool ieee80211_frame_allowed(struct ieee80211_rx_data *rx, __le16 fc)
1728 {
1729 	static const u8 pae_group_addr[ETH_ALEN] __aligned(2)
1730 		= { 0x01, 0x80, 0xC2, 0x00, 0x00, 0x03 };
1731 	struct ethhdr *ehdr = (struct ethhdr *) rx->skb->data;
1732 
1733 	/*
1734 	 * Allow EAPOL frames to us/the PAE group address regardless
1735 	 * of whether the frame was encrypted or not.
1736 	 */
1737 	if (ehdr->h_proto == rx->sdata->control_port_protocol &&
1738 	    (compare_ether_addr(ehdr->h_dest, rx->sdata->vif.addr) == 0 ||
1739 	     compare_ether_addr(ehdr->h_dest, pae_group_addr) == 0))
1740 		return true;
1741 
1742 	if (ieee80211_802_1x_port_control(rx) ||
1743 	    ieee80211_drop_unencrypted(rx, fc))
1744 		return false;
1745 
1746 	return true;
1747 }
1748 
1749 /*
1750  * requires that rx->skb is a frame with ethernet header
1751  */
1752 static void
1753 ieee80211_deliver_skb(struct ieee80211_rx_data *rx)
1754 {
1755 	struct ieee80211_sub_if_data *sdata = rx->sdata;
1756 	struct net_device *dev = sdata->dev;
1757 	struct sk_buff *skb, *xmit_skb;
1758 	struct ethhdr *ehdr = (struct ethhdr *) rx->skb->data;
1759 	struct sta_info *dsta;
1760 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
1761 
1762 	skb = rx->skb;
1763 	xmit_skb = NULL;
1764 
1765 	if ((sdata->vif.type == NL80211_IFTYPE_AP ||
1766 	     sdata->vif.type == NL80211_IFTYPE_AP_VLAN) &&
1767 	    !(sdata->flags & IEEE80211_SDATA_DONT_BRIDGE_PACKETS) &&
1768 	    (status->rx_flags & IEEE80211_RX_RA_MATCH) &&
1769 	    (sdata->vif.type != NL80211_IFTYPE_AP_VLAN || !sdata->u.vlan.sta)) {
1770 		if (is_multicast_ether_addr(ehdr->h_dest)) {
1771 			/*
1772 			 * send multicast frames both to higher layers in
1773 			 * local net stack and back to the wireless medium
1774 			 */
1775 			xmit_skb = skb_copy(skb, GFP_ATOMIC);
1776 			if (!xmit_skb && net_ratelimit())
1777 				printk(KERN_DEBUG "%s: failed to clone "
1778 				       "multicast frame\n", dev->name);
1779 		} else {
1780 			dsta = sta_info_get(sdata, skb->data);
1781 			if (dsta) {
1782 				/*
1783 				 * The destination station is associated to
1784 				 * this AP (in this VLAN), so send the frame
1785 				 * directly to it and do not pass it to local
1786 				 * net stack.
1787 				 */
1788 				xmit_skb = skb;
1789 				skb = NULL;
1790 			}
1791 		}
1792 	}
1793 
1794 	if (skb) {
1795 		int align __maybe_unused;
1796 
1797 #ifndef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
1798 		/*
1799 		 * 'align' will only take the values 0 or 2 here
1800 		 * since all frames are required to be aligned
1801 		 * to 2-byte boundaries when being passed to
1802 		 * mac80211. That also explains the __skb_push()
1803 		 * below.
1804 		 */
1805 		align = ((unsigned long)(skb->data + sizeof(struct ethhdr))) & 3;
1806 		if (align) {
1807 			if (WARN_ON(skb_headroom(skb) < 3)) {
1808 				dev_kfree_skb(skb);
1809 				skb = NULL;
1810 			} else {
1811 				u8 *data = skb->data;
1812 				size_t len = skb_headlen(skb);
1813 				skb->data -= align;
1814 				memmove(skb->data, data, len);
1815 				skb_set_tail_pointer(skb, len);
1816 			}
1817 		}
1818 #endif
1819 
1820 		if (skb) {
1821 			/* deliver to local stack */
1822 			skb->protocol = eth_type_trans(skb, dev);
1823 			memset(skb->cb, 0, sizeof(skb->cb));
1824 			netif_receive_skb(skb);
1825 		}
1826 	}
1827 
1828 	if (xmit_skb) {
1829 		/* send to wireless media */
1830 		xmit_skb->protocol = htons(ETH_P_802_3);
1831 		skb_reset_network_header(xmit_skb);
1832 		skb_reset_mac_header(xmit_skb);
1833 		dev_queue_xmit(xmit_skb);
1834 	}
1835 }
1836 
1837 static ieee80211_rx_result debug_noinline
1838 ieee80211_rx_h_amsdu(struct ieee80211_rx_data *rx)
1839 {
1840 	struct net_device *dev = rx->sdata->dev;
1841 	struct sk_buff *skb = rx->skb;
1842 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
1843 	__le16 fc = hdr->frame_control;
1844 	struct sk_buff_head frame_list;
1845 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
1846 
1847 	if (unlikely(!ieee80211_is_data(fc)))
1848 		return RX_CONTINUE;
1849 
1850 	if (unlikely(!ieee80211_is_data_present(fc)))
1851 		return RX_DROP_MONITOR;
1852 
1853 	if (!(status->rx_flags & IEEE80211_RX_AMSDU))
1854 		return RX_CONTINUE;
1855 
1856 	if (ieee80211_has_a4(hdr->frame_control) &&
1857 	    rx->sdata->vif.type == NL80211_IFTYPE_AP_VLAN &&
1858 	    !rx->sdata->u.vlan.sta)
1859 		return RX_DROP_UNUSABLE;
1860 
1861 	if (is_multicast_ether_addr(hdr->addr1) &&
1862 	    ((rx->sdata->vif.type == NL80211_IFTYPE_AP_VLAN &&
1863 	      rx->sdata->u.vlan.sta) ||
1864 	     (rx->sdata->vif.type == NL80211_IFTYPE_STATION &&
1865 	      rx->sdata->u.mgd.use_4addr)))
1866 		return RX_DROP_UNUSABLE;
1867 
1868 	skb->dev = dev;
1869 	__skb_queue_head_init(&frame_list);
1870 
1871 	if (skb_linearize(skb))
1872 		return RX_DROP_UNUSABLE;
1873 
1874 	ieee80211_amsdu_to_8023s(skb, &frame_list, dev->dev_addr,
1875 				 rx->sdata->vif.type,
1876 				 rx->local->hw.extra_tx_headroom, true);
1877 
1878 	while (!skb_queue_empty(&frame_list)) {
1879 		rx->skb = __skb_dequeue(&frame_list);
1880 
1881 		if (!ieee80211_frame_allowed(rx, fc)) {
1882 			dev_kfree_skb(rx->skb);
1883 			continue;
1884 		}
1885 		dev->stats.rx_packets++;
1886 		dev->stats.rx_bytes += rx->skb->len;
1887 
1888 		ieee80211_deliver_skb(rx);
1889 	}
1890 
1891 	return RX_QUEUED;
1892 }
1893 
1894 #ifdef CONFIG_MAC80211_MESH
1895 static ieee80211_rx_result
1896 ieee80211_rx_h_mesh_fwding(struct ieee80211_rx_data *rx)
1897 {
1898 	struct ieee80211_hdr *fwd_hdr, *hdr;
1899 	struct ieee80211_tx_info *info;
1900 	struct ieee80211s_hdr *mesh_hdr;
1901 	struct sk_buff *skb = rx->skb, *fwd_skb;
1902 	struct ieee80211_local *local = rx->local;
1903 	struct ieee80211_sub_if_data *sdata = rx->sdata;
1904 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
1905 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
1906 	__le16 reason = cpu_to_le16(WLAN_REASON_MESH_PATH_NOFORWARD);
1907 	u16 q, hdrlen;
1908 
1909 	hdr = (struct ieee80211_hdr *) skb->data;
1910 	hdrlen = ieee80211_hdrlen(hdr->frame_control);
1911 	mesh_hdr = (struct ieee80211s_hdr *) (skb->data + hdrlen);
1912 
1913 	/* frame is in RMC, don't forward */
1914 	if (ieee80211_is_data(hdr->frame_control) &&
1915 	    is_multicast_ether_addr(hdr->addr1) &&
1916 	    mesh_rmc_check(hdr->addr3, mesh_hdr, rx->sdata))
1917 		return RX_DROP_MONITOR;
1918 
1919 	if (!ieee80211_is_data(hdr->frame_control))
1920 		return RX_CONTINUE;
1921 
1922 	if (!mesh_hdr->ttl)
1923 		return RX_DROP_MONITOR;
1924 
1925 	if (mesh_hdr->flags & MESH_FLAGS_AE) {
1926 		struct mesh_path *mppath;
1927 		char *proxied_addr;
1928 		char *mpp_addr;
1929 
1930 		if (is_multicast_ether_addr(hdr->addr1)) {
1931 			mpp_addr = hdr->addr3;
1932 			proxied_addr = mesh_hdr->eaddr1;
1933 		} else {
1934 			mpp_addr = hdr->addr4;
1935 			proxied_addr = mesh_hdr->eaddr2;
1936 		}
1937 
1938 		rcu_read_lock();
1939 		mppath = mpp_path_lookup(proxied_addr, sdata);
1940 		if (!mppath) {
1941 			mpp_path_add(proxied_addr, mpp_addr, sdata);
1942 		} else {
1943 			spin_lock_bh(&mppath->state_lock);
1944 			if (compare_ether_addr(mppath->mpp, mpp_addr) != 0)
1945 				memcpy(mppath->mpp, mpp_addr, ETH_ALEN);
1946 			spin_unlock_bh(&mppath->state_lock);
1947 		}
1948 		rcu_read_unlock();
1949 	}
1950 
1951 	/* Frame has reached destination.  Don't forward */
1952 	if (!is_multicast_ether_addr(hdr->addr1) &&
1953 	    compare_ether_addr(sdata->vif.addr, hdr->addr3) == 0)
1954 		return RX_CONTINUE;
1955 
1956 	q = ieee80211_select_queue_80211(local, skb, hdr);
1957 	if (ieee80211_queue_stopped(&local->hw, q)) {
1958 		IEEE80211_IFSTA_MESH_CTR_INC(ifmsh, dropped_frames_congestion);
1959 		return RX_DROP_MONITOR;
1960 	}
1961 	skb_set_queue_mapping(skb, q);
1962 
1963 	if (!(status->rx_flags & IEEE80211_RX_RA_MATCH))
1964 		goto out;
1965 
1966 	if (!--mesh_hdr->ttl) {
1967 		IEEE80211_IFSTA_MESH_CTR_INC(ifmsh, dropped_frames_ttl);
1968 		return RX_DROP_MONITOR;
1969 	}
1970 
1971 	fwd_skb = skb_copy(skb, GFP_ATOMIC);
1972 	if (!fwd_skb) {
1973 		if (net_ratelimit())
1974 			printk(KERN_DEBUG "%s: failed to clone mesh frame\n",
1975 					sdata->name);
1976 		goto out;
1977 	}
1978 
1979 	fwd_hdr =  (struct ieee80211_hdr *) fwd_skb->data;
1980 	info = IEEE80211_SKB_CB(fwd_skb);
1981 	memset(info, 0, sizeof(*info));
1982 	info->flags |= IEEE80211_TX_INTFL_NEED_TXPROCESSING;
1983 	info->control.vif = &rx->sdata->vif;
1984 	info->control.jiffies = jiffies;
1985 	if (is_multicast_ether_addr(fwd_hdr->addr1)) {
1986 		IEEE80211_IFSTA_MESH_CTR_INC(ifmsh, fwded_mcast);
1987 		memcpy(fwd_hdr->addr2, sdata->vif.addr, ETH_ALEN);
1988 	} else if (!mesh_nexthop_lookup(fwd_skb, sdata)) {
1989 		IEEE80211_IFSTA_MESH_CTR_INC(ifmsh, fwded_unicast);
1990 	} else {
1991 		/* unable to resolve next hop */
1992 		mesh_path_error_tx(ifmsh->mshcfg.element_ttl, fwd_hdr->addr3,
1993 				    0, reason, fwd_hdr->addr2, sdata);
1994 		IEEE80211_IFSTA_MESH_CTR_INC(ifmsh, dropped_frames_no_route);
1995 		return RX_DROP_MONITOR;
1996 	}
1997 
1998 	IEEE80211_IFSTA_MESH_CTR_INC(ifmsh, fwded_frames);
1999 	ieee80211_add_pending_skb(local, fwd_skb);
2000  out:
2001 	if (is_multicast_ether_addr(hdr->addr1) ||
2002 	    sdata->dev->flags & IFF_PROMISC)
2003 		return RX_CONTINUE;
2004 	else
2005 		return RX_DROP_MONITOR;
2006 }
2007 #endif
2008 
2009 static ieee80211_rx_result debug_noinline
2010 ieee80211_rx_h_data(struct ieee80211_rx_data *rx)
2011 {
2012 	struct ieee80211_sub_if_data *sdata = rx->sdata;
2013 	struct ieee80211_local *local = rx->local;
2014 	struct net_device *dev = sdata->dev;
2015 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
2016 	__le16 fc = hdr->frame_control;
2017 	bool port_control;
2018 	int err;
2019 
2020 	if (unlikely(!ieee80211_is_data(hdr->frame_control)))
2021 		return RX_CONTINUE;
2022 
2023 	if (unlikely(!ieee80211_is_data_present(hdr->frame_control)))
2024 		return RX_DROP_MONITOR;
2025 
2026 	/*
2027 	 * Send unexpected-4addr-frame event to hostapd. For older versions,
2028 	 * also drop the frame to cooked monitor interfaces.
2029 	 */
2030 	if (ieee80211_has_a4(hdr->frame_control) &&
2031 	    sdata->vif.type == NL80211_IFTYPE_AP) {
2032 		if (rx->sta &&
2033 		    !test_and_set_sta_flag(rx->sta, WLAN_STA_4ADDR_EVENT))
2034 			cfg80211_rx_unexpected_4addr_frame(
2035 				rx->sdata->dev, rx->sta->sta.addr, GFP_ATOMIC);
2036 		return RX_DROP_MONITOR;
2037 	}
2038 
2039 	err = __ieee80211_data_to_8023(rx, &port_control);
2040 	if (unlikely(err))
2041 		return RX_DROP_UNUSABLE;
2042 
2043 	if (!ieee80211_frame_allowed(rx, fc))
2044 		return RX_DROP_MONITOR;
2045 
2046 	if (rx->sdata->vif.type == NL80211_IFTYPE_AP_VLAN &&
2047 	    unlikely(port_control) && sdata->bss) {
2048 		sdata = container_of(sdata->bss, struct ieee80211_sub_if_data,
2049 				     u.ap);
2050 		dev = sdata->dev;
2051 		rx->sdata = sdata;
2052 	}
2053 
2054 	rx->skb->dev = dev;
2055 
2056 	dev->stats.rx_packets++;
2057 	dev->stats.rx_bytes += rx->skb->len;
2058 
2059 	if (local->ps_sdata && local->hw.conf.dynamic_ps_timeout > 0 &&
2060 	    !is_multicast_ether_addr(
2061 		    ((struct ethhdr *)rx->skb->data)->h_dest) &&
2062 	    (!local->scanning &&
2063 	     !test_bit(SDATA_STATE_OFFCHANNEL, &sdata->state))) {
2064 			mod_timer(&local->dynamic_ps_timer, jiffies +
2065 			 msecs_to_jiffies(local->hw.conf.dynamic_ps_timeout));
2066 	}
2067 
2068 	ieee80211_deliver_skb(rx);
2069 
2070 	return RX_QUEUED;
2071 }
2072 
2073 static ieee80211_rx_result debug_noinline
2074 ieee80211_rx_h_ctrl(struct ieee80211_rx_data *rx)
2075 {
2076 	struct ieee80211_local *local = rx->local;
2077 	struct ieee80211_hw *hw = &local->hw;
2078 	struct sk_buff *skb = rx->skb;
2079 	struct ieee80211_bar *bar = (struct ieee80211_bar *)skb->data;
2080 	struct tid_ampdu_rx *tid_agg_rx;
2081 	u16 start_seq_num;
2082 	u16 tid;
2083 
2084 	if (likely(!ieee80211_is_ctl(bar->frame_control)))
2085 		return RX_CONTINUE;
2086 
2087 	if (ieee80211_is_back_req(bar->frame_control)) {
2088 		struct {
2089 			__le16 control, start_seq_num;
2090 		} __packed bar_data;
2091 
2092 		if (!rx->sta)
2093 			return RX_DROP_MONITOR;
2094 
2095 		if (skb_copy_bits(skb, offsetof(struct ieee80211_bar, control),
2096 				  &bar_data, sizeof(bar_data)))
2097 			return RX_DROP_MONITOR;
2098 
2099 		tid = le16_to_cpu(bar_data.control) >> 12;
2100 
2101 		tid_agg_rx = rcu_dereference(rx->sta->ampdu_mlme.tid_rx[tid]);
2102 		if (!tid_agg_rx)
2103 			return RX_DROP_MONITOR;
2104 
2105 		start_seq_num = le16_to_cpu(bar_data.start_seq_num) >> 4;
2106 
2107 		/* reset session timer */
2108 		if (tid_agg_rx->timeout)
2109 			mod_timer(&tid_agg_rx->session_timer,
2110 				  TU_TO_EXP_TIME(tid_agg_rx->timeout));
2111 
2112 		spin_lock(&tid_agg_rx->reorder_lock);
2113 		/* release stored frames up to start of BAR */
2114 		ieee80211_release_reorder_frames(hw, tid_agg_rx, start_seq_num);
2115 		spin_unlock(&tid_agg_rx->reorder_lock);
2116 
2117 		kfree_skb(skb);
2118 		return RX_QUEUED;
2119 	}
2120 
2121 	/*
2122 	 * After this point, we only want management frames,
2123 	 * so we can drop all remaining control frames to
2124 	 * cooked monitor interfaces.
2125 	 */
2126 	return RX_DROP_MONITOR;
2127 }
2128 
2129 static void ieee80211_process_sa_query_req(struct ieee80211_sub_if_data *sdata,
2130 					   struct ieee80211_mgmt *mgmt,
2131 					   size_t len)
2132 {
2133 	struct ieee80211_local *local = sdata->local;
2134 	struct sk_buff *skb;
2135 	struct ieee80211_mgmt *resp;
2136 
2137 	if (compare_ether_addr(mgmt->da, sdata->vif.addr) != 0) {
2138 		/* Not to own unicast address */
2139 		return;
2140 	}
2141 
2142 	if (compare_ether_addr(mgmt->sa, sdata->u.mgd.bssid) != 0 ||
2143 	    compare_ether_addr(mgmt->bssid, sdata->u.mgd.bssid) != 0) {
2144 		/* Not from the current AP or not associated yet. */
2145 		return;
2146 	}
2147 
2148 	if (len < 24 + 1 + sizeof(resp->u.action.u.sa_query)) {
2149 		/* Too short SA Query request frame */
2150 		return;
2151 	}
2152 
2153 	skb = dev_alloc_skb(sizeof(*resp) + local->hw.extra_tx_headroom);
2154 	if (skb == NULL)
2155 		return;
2156 
2157 	skb_reserve(skb, local->hw.extra_tx_headroom);
2158 	resp = (struct ieee80211_mgmt *) skb_put(skb, 24);
2159 	memset(resp, 0, 24);
2160 	memcpy(resp->da, mgmt->sa, ETH_ALEN);
2161 	memcpy(resp->sa, sdata->vif.addr, ETH_ALEN);
2162 	memcpy(resp->bssid, sdata->u.mgd.bssid, ETH_ALEN);
2163 	resp->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
2164 					  IEEE80211_STYPE_ACTION);
2165 	skb_put(skb, 1 + sizeof(resp->u.action.u.sa_query));
2166 	resp->u.action.category = WLAN_CATEGORY_SA_QUERY;
2167 	resp->u.action.u.sa_query.action = WLAN_ACTION_SA_QUERY_RESPONSE;
2168 	memcpy(resp->u.action.u.sa_query.trans_id,
2169 	       mgmt->u.action.u.sa_query.trans_id,
2170 	       WLAN_SA_QUERY_TR_ID_LEN);
2171 
2172 	ieee80211_tx_skb(sdata, skb);
2173 }
2174 
2175 static ieee80211_rx_result debug_noinline
2176 ieee80211_rx_h_mgmt_check(struct ieee80211_rx_data *rx)
2177 {
2178 	struct ieee80211_mgmt *mgmt = (struct ieee80211_mgmt *) rx->skb->data;
2179 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
2180 
2181 	/*
2182 	 * From here on, look only at management frames.
2183 	 * Data and control frames are already handled,
2184 	 * and unknown (reserved) frames are useless.
2185 	 */
2186 	if (rx->skb->len < 24)
2187 		return RX_DROP_MONITOR;
2188 
2189 	if (!ieee80211_is_mgmt(mgmt->frame_control))
2190 		return RX_DROP_MONITOR;
2191 
2192 	if (rx->sdata->vif.type == NL80211_IFTYPE_AP &&
2193 	    ieee80211_is_beacon(mgmt->frame_control) &&
2194 	    !(rx->flags & IEEE80211_RX_BEACON_REPORTED)) {
2195 		struct ieee80211_rx_status *status;
2196 
2197 		status = IEEE80211_SKB_RXCB(rx->skb);
2198 		cfg80211_report_obss_beacon(rx->local->hw.wiphy,
2199 					    rx->skb->data, rx->skb->len,
2200 					    status->freq, GFP_ATOMIC);
2201 		rx->flags |= IEEE80211_RX_BEACON_REPORTED;
2202 	}
2203 
2204 	if (!(status->rx_flags & IEEE80211_RX_RA_MATCH))
2205 		return RX_DROP_MONITOR;
2206 
2207 	if (ieee80211_drop_unencrypted_mgmt(rx))
2208 		return RX_DROP_UNUSABLE;
2209 
2210 	return RX_CONTINUE;
2211 }
2212 
2213 static ieee80211_rx_result debug_noinline
2214 ieee80211_rx_h_action(struct ieee80211_rx_data *rx)
2215 {
2216 	struct ieee80211_local *local = rx->local;
2217 	struct ieee80211_sub_if_data *sdata = rx->sdata;
2218 	struct ieee80211_mgmt *mgmt = (struct ieee80211_mgmt *) rx->skb->data;
2219 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
2220 	int len = rx->skb->len;
2221 
2222 	if (!ieee80211_is_action(mgmt->frame_control))
2223 		return RX_CONTINUE;
2224 
2225 	/* drop too small frames */
2226 	if (len < IEEE80211_MIN_ACTION_SIZE)
2227 		return RX_DROP_UNUSABLE;
2228 
2229 	if (!rx->sta && mgmt->u.action.category != WLAN_CATEGORY_PUBLIC)
2230 		return RX_DROP_UNUSABLE;
2231 
2232 	if (!(status->rx_flags & IEEE80211_RX_RA_MATCH))
2233 		return RX_DROP_UNUSABLE;
2234 
2235 	switch (mgmt->u.action.category) {
2236 	case WLAN_CATEGORY_BACK:
2237 		if (sdata->vif.type != NL80211_IFTYPE_STATION &&
2238 		    sdata->vif.type != NL80211_IFTYPE_MESH_POINT &&
2239 		    sdata->vif.type != NL80211_IFTYPE_AP_VLAN &&
2240 		    sdata->vif.type != NL80211_IFTYPE_AP &&
2241 		    sdata->vif.type != NL80211_IFTYPE_ADHOC)
2242 			break;
2243 
2244 		/* verify action_code is present */
2245 		if (len < IEEE80211_MIN_ACTION_SIZE + 1)
2246 			break;
2247 
2248 		switch (mgmt->u.action.u.addba_req.action_code) {
2249 		case WLAN_ACTION_ADDBA_REQ:
2250 			if (len < (IEEE80211_MIN_ACTION_SIZE +
2251 				   sizeof(mgmt->u.action.u.addba_req)))
2252 				goto invalid;
2253 			break;
2254 		case WLAN_ACTION_ADDBA_RESP:
2255 			if (len < (IEEE80211_MIN_ACTION_SIZE +
2256 				   sizeof(mgmt->u.action.u.addba_resp)))
2257 				goto invalid;
2258 			break;
2259 		case WLAN_ACTION_DELBA:
2260 			if (len < (IEEE80211_MIN_ACTION_SIZE +
2261 				   sizeof(mgmt->u.action.u.delba)))
2262 				goto invalid;
2263 			break;
2264 		default:
2265 			goto invalid;
2266 		}
2267 
2268 		goto queue;
2269 	case WLAN_CATEGORY_SPECTRUM_MGMT:
2270 		if (local->hw.conf.channel->band != IEEE80211_BAND_5GHZ)
2271 			break;
2272 
2273 		if (sdata->vif.type != NL80211_IFTYPE_STATION)
2274 			break;
2275 
2276 		/* verify action_code is present */
2277 		if (len < IEEE80211_MIN_ACTION_SIZE + 1)
2278 			break;
2279 
2280 		switch (mgmt->u.action.u.measurement.action_code) {
2281 		case WLAN_ACTION_SPCT_MSR_REQ:
2282 			if (len < (IEEE80211_MIN_ACTION_SIZE +
2283 				   sizeof(mgmt->u.action.u.measurement)))
2284 				break;
2285 			ieee80211_process_measurement_req(sdata, mgmt, len);
2286 			goto handled;
2287 		case WLAN_ACTION_SPCT_CHL_SWITCH:
2288 			if (len < (IEEE80211_MIN_ACTION_SIZE +
2289 				   sizeof(mgmt->u.action.u.chan_switch)))
2290 				break;
2291 
2292 			if (sdata->vif.type != NL80211_IFTYPE_STATION)
2293 				break;
2294 
2295 			if (memcmp(mgmt->bssid, sdata->u.mgd.bssid, ETH_ALEN))
2296 				break;
2297 
2298 			goto queue;
2299 		}
2300 		break;
2301 	case WLAN_CATEGORY_SA_QUERY:
2302 		if (len < (IEEE80211_MIN_ACTION_SIZE +
2303 			   sizeof(mgmt->u.action.u.sa_query)))
2304 			break;
2305 
2306 		switch (mgmt->u.action.u.sa_query.action) {
2307 		case WLAN_ACTION_SA_QUERY_REQUEST:
2308 			if (sdata->vif.type != NL80211_IFTYPE_STATION)
2309 				break;
2310 			ieee80211_process_sa_query_req(sdata, mgmt, len);
2311 			goto handled;
2312 		}
2313 		break;
2314 	case WLAN_CATEGORY_SELF_PROTECTED:
2315 		switch (mgmt->u.action.u.self_prot.action_code) {
2316 		case WLAN_SP_MESH_PEERING_OPEN:
2317 		case WLAN_SP_MESH_PEERING_CLOSE:
2318 		case WLAN_SP_MESH_PEERING_CONFIRM:
2319 			if (!ieee80211_vif_is_mesh(&sdata->vif))
2320 				goto invalid;
2321 			if (sdata->u.mesh.security != IEEE80211_MESH_SEC_NONE)
2322 				/* userspace handles this frame */
2323 				break;
2324 			goto queue;
2325 		case WLAN_SP_MGK_INFORM:
2326 		case WLAN_SP_MGK_ACK:
2327 			if (!ieee80211_vif_is_mesh(&sdata->vif))
2328 				goto invalid;
2329 			break;
2330 		}
2331 		break;
2332 	case WLAN_CATEGORY_MESH_ACTION:
2333 		if (!ieee80211_vif_is_mesh(&sdata->vif))
2334 			break;
2335 		if (mesh_action_is_path_sel(mgmt) &&
2336 		  (!mesh_path_sel_is_hwmp(sdata)))
2337 			break;
2338 		goto queue;
2339 	}
2340 
2341 	return RX_CONTINUE;
2342 
2343  invalid:
2344 	status->rx_flags |= IEEE80211_RX_MALFORMED_ACTION_FRM;
2345 	/* will return in the next handlers */
2346 	return RX_CONTINUE;
2347 
2348  handled:
2349 	if (rx->sta)
2350 		rx->sta->rx_packets++;
2351 	dev_kfree_skb(rx->skb);
2352 	return RX_QUEUED;
2353 
2354  queue:
2355 	rx->skb->pkt_type = IEEE80211_SDATA_QUEUE_TYPE_FRAME;
2356 	skb_queue_tail(&sdata->skb_queue, rx->skb);
2357 	ieee80211_queue_work(&local->hw, &sdata->work);
2358 	if (rx->sta)
2359 		rx->sta->rx_packets++;
2360 	return RX_QUEUED;
2361 }
2362 
2363 static ieee80211_rx_result debug_noinline
2364 ieee80211_rx_h_userspace_mgmt(struct ieee80211_rx_data *rx)
2365 {
2366 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
2367 
2368 	/* skip known-bad action frames and return them in the next handler */
2369 	if (status->rx_flags & IEEE80211_RX_MALFORMED_ACTION_FRM)
2370 		return RX_CONTINUE;
2371 
2372 	/*
2373 	 * Getting here means the kernel doesn't know how to handle
2374 	 * it, but maybe userspace does ... include returned frames
2375 	 * so userspace can register for those to know whether ones
2376 	 * it transmitted were processed or returned.
2377 	 */
2378 
2379 	if (cfg80211_rx_mgmt(rx->sdata->dev, status->freq,
2380 			     rx->skb->data, rx->skb->len,
2381 			     GFP_ATOMIC)) {
2382 		if (rx->sta)
2383 			rx->sta->rx_packets++;
2384 		dev_kfree_skb(rx->skb);
2385 		return RX_QUEUED;
2386 	}
2387 
2388 
2389 	return RX_CONTINUE;
2390 }
2391 
2392 static ieee80211_rx_result debug_noinline
2393 ieee80211_rx_h_action_return(struct ieee80211_rx_data *rx)
2394 {
2395 	struct ieee80211_local *local = rx->local;
2396 	struct ieee80211_mgmt *mgmt = (struct ieee80211_mgmt *) rx->skb->data;
2397 	struct sk_buff *nskb;
2398 	struct ieee80211_sub_if_data *sdata = rx->sdata;
2399 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
2400 
2401 	if (!ieee80211_is_action(mgmt->frame_control))
2402 		return RX_CONTINUE;
2403 
2404 	/*
2405 	 * For AP mode, hostapd is responsible for handling any action
2406 	 * frames that we didn't handle, including returning unknown
2407 	 * ones. For all other modes we will return them to the sender,
2408 	 * setting the 0x80 bit in the action category, as required by
2409 	 * 802.11-2007 7.3.1.11.
2410 	 * Newer versions of hostapd shall also use the management frame
2411 	 * registration mechanisms, but older ones still use cooked
2412 	 * monitor interfaces so push all frames there.
2413 	 */
2414 	if (!(status->rx_flags & IEEE80211_RX_MALFORMED_ACTION_FRM) &&
2415 	    (sdata->vif.type == NL80211_IFTYPE_AP ||
2416 	     sdata->vif.type == NL80211_IFTYPE_AP_VLAN))
2417 		return RX_DROP_MONITOR;
2418 
2419 	/* do not return rejected action frames */
2420 	if (mgmt->u.action.category & 0x80)
2421 		return RX_DROP_UNUSABLE;
2422 
2423 	nskb = skb_copy_expand(rx->skb, local->hw.extra_tx_headroom, 0,
2424 			       GFP_ATOMIC);
2425 	if (nskb) {
2426 		struct ieee80211_mgmt *nmgmt = (void *)nskb->data;
2427 
2428 		nmgmt->u.action.category |= 0x80;
2429 		memcpy(nmgmt->da, nmgmt->sa, ETH_ALEN);
2430 		memcpy(nmgmt->sa, rx->sdata->vif.addr, ETH_ALEN);
2431 
2432 		memset(nskb->cb, 0, sizeof(nskb->cb));
2433 
2434 		ieee80211_tx_skb(rx->sdata, nskb);
2435 	}
2436 	dev_kfree_skb(rx->skb);
2437 	return RX_QUEUED;
2438 }
2439 
2440 static ieee80211_rx_result debug_noinline
2441 ieee80211_rx_h_mgmt(struct ieee80211_rx_data *rx)
2442 {
2443 	struct ieee80211_sub_if_data *sdata = rx->sdata;
2444 	ieee80211_rx_result rxs;
2445 	struct ieee80211_mgmt *mgmt = (void *)rx->skb->data;
2446 	__le16 stype;
2447 
2448 	rxs = ieee80211_work_rx_mgmt(rx->sdata, rx->skb);
2449 	if (rxs != RX_CONTINUE)
2450 		return rxs;
2451 
2452 	stype = mgmt->frame_control & cpu_to_le16(IEEE80211_FCTL_STYPE);
2453 
2454 	if (!ieee80211_vif_is_mesh(&sdata->vif) &&
2455 	    sdata->vif.type != NL80211_IFTYPE_ADHOC &&
2456 	    sdata->vif.type != NL80211_IFTYPE_STATION)
2457 		return RX_DROP_MONITOR;
2458 
2459 	switch (stype) {
2460 	case cpu_to_le16(IEEE80211_STYPE_BEACON):
2461 	case cpu_to_le16(IEEE80211_STYPE_PROBE_RESP):
2462 		/* process for all: mesh, mlme, ibss */
2463 		break;
2464 	case cpu_to_le16(IEEE80211_STYPE_DEAUTH):
2465 	case cpu_to_le16(IEEE80211_STYPE_DISASSOC):
2466 		if (is_multicast_ether_addr(mgmt->da) &&
2467 		    !is_broadcast_ether_addr(mgmt->da))
2468 			return RX_DROP_MONITOR;
2469 
2470 		/* process only for station */
2471 		if (sdata->vif.type != NL80211_IFTYPE_STATION)
2472 			return RX_DROP_MONITOR;
2473 		break;
2474 	case cpu_to_le16(IEEE80211_STYPE_PROBE_REQ):
2475 	case cpu_to_le16(IEEE80211_STYPE_AUTH):
2476 		/* process only for ibss */
2477 		if (sdata->vif.type != NL80211_IFTYPE_ADHOC)
2478 			return RX_DROP_MONITOR;
2479 		break;
2480 	default:
2481 		return RX_DROP_MONITOR;
2482 	}
2483 
2484 	/* queue up frame and kick off work to process it */
2485 	rx->skb->pkt_type = IEEE80211_SDATA_QUEUE_TYPE_FRAME;
2486 	skb_queue_tail(&sdata->skb_queue, rx->skb);
2487 	ieee80211_queue_work(&rx->local->hw, &sdata->work);
2488 	if (rx->sta)
2489 		rx->sta->rx_packets++;
2490 
2491 	return RX_QUEUED;
2492 }
2493 
2494 /* TODO: use IEEE80211_RX_FRAGMENTED */
2495 static void ieee80211_rx_cooked_monitor(struct ieee80211_rx_data *rx,
2496 					struct ieee80211_rate *rate)
2497 {
2498 	struct ieee80211_sub_if_data *sdata;
2499 	struct ieee80211_local *local = rx->local;
2500 	struct ieee80211_rtap_hdr {
2501 		struct ieee80211_radiotap_header hdr;
2502 		u8 flags;
2503 		u8 rate_or_pad;
2504 		__le16 chan_freq;
2505 		__le16 chan_flags;
2506 	} __packed *rthdr;
2507 	struct sk_buff *skb = rx->skb, *skb2;
2508 	struct net_device *prev_dev = NULL;
2509 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
2510 
2511 	/*
2512 	 * If cooked monitor has been processed already, then
2513 	 * don't do it again. If not, set the flag.
2514 	 */
2515 	if (rx->flags & IEEE80211_RX_CMNTR)
2516 		goto out_free_skb;
2517 	rx->flags |= IEEE80211_RX_CMNTR;
2518 
2519 	/* If there are no cooked monitor interfaces, just free the SKB */
2520 	if (!local->cooked_mntrs)
2521 		goto out_free_skb;
2522 
2523 	if (skb_headroom(skb) < sizeof(*rthdr) &&
2524 	    pskb_expand_head(skb, sizeof(*rthdr), 0, GFP_ATOMIC))
2525 		goto out_free_skb;
2526 
2527 	rthdr = (void *)skb_push(skb, sizeof(*rthdr));
2528 	memset(rthdr, 0, sizeof(*rthdr));
2529 	rthdr->hdr.it_len = cpu_to_le16(sizeof(*rthdr));
2530 	rthdr->hdr.it_present =
2531 		cpu_to_le32((1 << IEEE80211_RADIOTAP_FLAGS) |
2532 			    (1 << IEEE80211_RADIOTAP_CHANNEL));
2533 
2534 	if (rate) {
2535 		rthdr->rate_or_pad = rate->bitrate / 5;
2536 		rthdr->hdr.it_present |=
2537 			cpu_to_le32(1 << IEEE80211_RADIOTAP_RATE);
2538 	}
2539 	rthdr->chan_freq = cpu_to_le16(status->freq);
2540 
2541 	if (status->band == IEEE80211_BAND_5GHZ)
2542 		rthdr->chan_flags = cpu_to_le16(IEEE80211_CHAN_OFDM |
2543 						IEEE80211_CHAN_5GHZ);
2544 	else
2545 		rthdr->chan_flags = cpu_to_le16(IEEE80211_CHAN_DYN |
2546 						IEEE80211_CHAN_2GHZ);
2547 
2548 	skb_set_mac_header(skb, 0);
2549 	skb->ip_summed = CHECKSUM_UNNECESSARY;
2550 	skb->pkt_type = PACKET_OTHERHOST;
2551 	skb->protocol = htons(ETH_P_802_2);
2552 
2553 	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
2554 		if (!ieee80211_sdata_running(sdata))
2555 			continue;
2556 
2557 		if (sdata->vif.type != NL80211_IFTYPE_MONITOR ||
2558 		    !(sdata->u.mntr_flags & MONITOR_FLAG_COOK_FRAMES))
2559 			continue;
2560 
2561 		if (prev_dev) {
2562 			skb2 = skb_clone(skb, GFP_ATOMIC);
2563 			if (skb2) {
2564 				skb2->dev = prev_dev;
2565 				netif_receive_skb(skb2);
2566 			}
2567 		}
2568 
2569 		prev_dev = sdata->dev;
2570 		sdata->dev->stats.rx_packets++;
2571 		sdata->dev->stats.rx_bytes += skb->len;
2572 	}
2573 
2574 	if (prev_dev) {
2575 		skb->dev = prev_dev;
2576 		netif_receive_skb(skb);
2577 		return;
2578 	}
2579 
2580  out_free_skb:
2581 	dev_kfree_skb(skb);
2582 }
2583 
2584 static void ieee80211_rx_handlers_result(struct ieee80211_rx_data *rx,
2585 					 ieee80211_rx_result res)
2586 {
2587 	switch (res) {
2588 	case RX_DROP_MONITOR:
2589 		I802_DEBUG_INC(rx->sdata->local->rx_handlers_drop);
2590 		if (rx->sta)
2591 			rx->sta->rx_dropped++;
2592 		/* fall through */
2593 	case RX_CONTINUE: {
2594 		struct ieee80211_rate *rate = NULL;
2595 		struct ieee80211_supported_band *sband;
2596 		struct ieee80211_rx_status *status;
2597 
2598 		status = IEEE80211_SKB_RXCB((rx->skb));
2599 
2600 		sband = rx->local->hw.wiphy->bands[status->band];
2601 		if (!(status->flag & RX_FLAG_HT))
2602 			rate = &sband->bitrates[status->rate_idx];
2603 
2604 		ieee80211_rx_cooked_monitor(rx, rate);
2605 		break;
2606 		}
2607 	case RX_DROP_UNUSABLE:
2608 		I802_DEBUG_INC(rx->sdata->local->rx_handlers_drop);
2609 		if (rx->sta)
2610 			rx->sta->rx_dropped++;
2611 		dev_kfree_skb(rx->skb);
2612 		break;
2613 	case RX_QUEUED:
2614 		I802_DEBUG_INC(rx->sdata->local->rx_handlers_queued);
2615 		break;
2616 	}
2617 }
2618 
2619 static void ieee80211_rx_handlers(struct ieee80211_rx_data *rx)
2620 {
2621 	ieee80211_rx_result res = RX_DROP_MONITOR;
2622 	struct sk_buff *skb;
2623 
2624 #define CALL_RXH(rxh)			\
2625 	do {				\
2626 		res = rxh(rx);		\
2627 		if (res != RX_CONTINUE)	\
2628 			goto rxh_next;  \
2629 	} while (0);
2630 
2631 	spin_lock(&rx->local->rx_skb_queue.lock);
2632 	if (rx->local->running_rx_handler)
2633 		goto unlock;
2634 
2635 	rx->local->running_rx_handler = true;
2636 
2637 	while ((skb = __skb_dequeue(&rx->local->rx_skb_queue))) {
2638 		spin_unlock(&rx->local->rx_skb_queue.lock);
2639 
2640 		/*
2641 		 * all the other fields are valid across frames
2642 		 * that belong to an aMPDU since they are on the
2643 		 * same TID from the same station
2644 		 */
2645 		rx->skb = skb;
2646 
2647 		CALL_RXH(ieee80211_rx_h_decrypt)
2648 		CALL_RXH(ieee80211_rx_h_check_more_data)
2649 		CALL_RXH(ieee80211_rx_h_uapsd_and_pspoll)
2650 		CALL_RXH(ieee80211_rx_h_sta_process)
2651 		CALL_RXH(ieee80211_rx_h_defragment)
2652 		CALL_RXH(ieee80211_rx_h_michael_mic_verify)
2653 		/* must be after MMIC verify so header is counted in MPDU mic */
2654 #ifdef CONFIG_MAC80211_MESH
2655 		if (ieee80211_vif_is_mesh(&rx->sdata->vif))
2656 			CALL_RXH(ieee80211_rx_h_mesh_fwding);
2657 #endif
2658 		CALL_RXH(ieee80211_rx_h_remove_qos_control)
2659 		CALL_RXH(ieee80211_rx_h_amsdu)
2660 		CALL_RXH(ieee80211_rx_h_data)
2661 		CALL_RXH(ieee80211_rx_h_ctrl);
2662 		CALL_RXH(ieee80211_rx_h_mgmt_check)
2663 		CALL_RXH(ieee80211_rx_h_action)
2664 		CALL_RXH(ieee80211_rx_h_userspace_mgmt)
2665 		CALL_RXH(ieee80211_rx_h_action_return)
2666 		CALL_RXH(ieee80211_rx_h_mgmt)
2667 
2668  rxh_next:
2669 		ieee80211_rx_handlers_result(rx, res);
2670 		spin_lock(&rx->local->rx_skb_queue.lock);
2671 #undef CALL_RXH
2672 	}
2673 
2674 	rx->local->running_rx_handler = false;
2675 
2676  unlock:
2677 	spin_unlock(&rx->local->rx_skb_queue.lock);
2678 }
2679 
2680 static void ieee80211_invoke_rx_handlers(struct ieee80211_rx_data *rx)
2681 {
2682 	ieee80211_rx_result res = RX_DROP_MONITOR;
2683 
2684 #define CALL_RXH(rxh)			\
2685 	do {				\
2686 		res = rxh(rx);		\
2687 		if (res != RX_CONTINUE)	\
2688 			goto rxh_next;  \
2689 	} while (0);
2690 
2691 	CALL_RXH(ieee80211_rx_h_passive_scan)
2692 	CALL_RXH(ieee80211_rx_h_check)
2693 
2694 	ieee80211_rx_reorder_ampdu(rx);
2695 
2696 	ieee80211_rx_handlers(rx);
2697 	return;
2698 
2699  rxh_next:
2700 	ieee80211_rx_handlers_result(rx, res);
2701 
2702 #undef CALL_RXH
2703 }
2704 
2705 /*
2706  * This function makes calls into the RX path, therefore
2707  * it has to be invoked under RCU read lock.
2708  */
2709 void ieee80211_release_reorder_timeout(struct sta_info *sta, int tid)
2710 {
2711 	struct ieee80211_rx_data rx = {
2712 		.sta = sta,
2713 		.sdata = sta->sdata,
2714 		.local = sta->local,
2715 		/* This is OK -- must be QoS data frame */
2716 		.security_idx = tid,
2717 		.seqno_idx = tid,
2718 		.flags = 0,
2719 	};
2720 	struct tid_ampdu_rx *tid_agg_rx;
2721 
2722 	tid_agg_rx = rcu_dereference(sta->ampdu_mlme.tid_rx[tid]);
2723 	if (!tid_agg_rx)
2724 		return;
2725 
2726 	spin_lock(&tid_agg_rx->reorder_lock);
2727 	ieee80211_sta_reorder_release(&sta->local->hw, tid_agg_rx);
2728 	spin_unlock(&tid_agg_rx->reorder_lock);
2729 
2730 	ieee80211_rx_handlers(&rx);
2731 }
2732 
2733 /* main receive path */
2734 
2735 static int prepare_for_handlers(struct ieee80211_rx_data *rx,
2736 				struct ieee80211_hdr *hdr)
2737 {
2738 	struct ieee80211_sub_if_data *sdata = rx->sdata;
2739 	struct sk_buff *skb = rx->skb;
2740 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
2741 	u8 *bssid = ieee80211_get_bssid(hdr, skb->len, sdata->vif.type);
2742 	int multicast = is_multicast_ether_addr(hdr->addr1);
2743 
2744 	switch (sdata->vif.type) {
2745 	case NL80211_IFTYPE_STATION:
2746 		if (!bssid && !sdata->u.mgd.use_4addr)
2747 			return 0;
2748 		if (!multicast &&
2749 		    compare_ether_addr(sdata->vif.addr, hdr->addr1) != 0) {
2750 			if (!(sdata->dev->flags & IFF_PROMISC) ||
2751 			    sdata->u.mgd.use_4addr)
2752 				return 0;
2753 			status->rx_flags &= ~IEEE80211_RX_RA_MATCH;
2754 		}
2755 		break;
2756 	case NL80211_IFTYPE_ADHOC:
2757 		if (!bssid)
2758 			return 0;
2759 		if (ieee80211_is_beacon(hdr->frame_control)) {
2760 			return 1;
2761 		}
2762 		else if (!ieee80211_bssid_match(bssid, sdata->u.ibss.bssid)) {
2763 			if (!(status->rx_flags & IEEE80211_RX_IN_SCAN))
2764 				return 0;
2765 			status->rx_flags &= ~IEEE80211_RX_RA_MATCH;
2766 		} else if (!multicast &&
2767 			   compare_ether_addr(sdata->vif.addr,
2768 					      hdr->addr1) != 0) {
2769 			if (!(sdata->dev->flags & IFF_PROMISC))
2770 				return 0;
2771 			status->rx_flags &= ~IEEE80211_RX_RA_MATCH;
2772 		} else if (!rx->sta) {
2773 			int rate_idx;
2774 			if (status->flag & RX_FLAG_HT)
2775 				rate_idx = 0; /* TODO: HT rates */
2776 			else
2777 				rate_idx = status->rate_idx;
2778 			ieee80211_ibss_rx_no_sta(sdata, bssid, hdr->addr2,
2779 						 BIT(rate_idx));
2780 		}
2781 		break;
2782 	case NL80211_IFTYPE_MESH_POINT:
2783 		if (!multicast &&
2784 		    compare_ether_addr(sdata->vif.addr,
2785 				       hdr->addr1) != 0) {
2786 			if (!(sdata->dev->flags & IFF_PROMISC))
2787 				return 0;
2788 
2789 			status->rx_flags &= ~IEEE80211_RX_RA_MATCH;
2790 		}
2791 		break;
2792 	case NL80211_IFTYPE_AP_VLAN:
2793 	case NL80211_IFTYPE_AP:
2794 		if (!bssid) {
2795 			if (compare_ether_addr(sdata->vif.addr,
2796 					       hdr->addr1))
2797 				return 0;
2798 		} else if (!ieee80211_bssid_match(bssid,
2799 					sdata->vif.addr)) {
2800 			/*
2801 			 * Accept public action frames even when the
2802 			 * BSSID doesn't match, this is used for P2P
2803 			 * and location updates. Note that mac80211
2804 			 * itself never looks at these frames.
2805 			 */
2806 			if (!(status->rx_flags & IEEE80211_RX_IN_SCAN) &&
2807 			    ieee80211_is_public_action(hdr, skb->len))
2808 				return 1;
2809 			if (!(status->rx_flags & IEEE80211_RX_IN_SCAN) &&
2810 			    !ieee80211_is_beacon(hdr->frame_control))
2811 				return 0;
2812 			status->rx_flags &= ~IEEE80211_RX_RA_MATCH;
2813 		}
2814 		break;
2815 	case NL80211_IFTYPE_WDS:
2816 		if (bssid || !ieee80211_is_data(hdr->frame_control))
2817 			return 0;
2818 		if (compare_ether_addr(sdata->u.wds.remote_addr, hdr->addr2))
2819 			return 0;
2820 		break;
2821 	default:
2822 		/* should never get here */
2823 		WARN_ON(1);
2824 		break;
2825 	}
2826 
2827 	return 1;
2828 }
2829 
2830 /*
2831  * This function returns whether or not the SKB
2832  * was destined for RX processing or not, which,
2833  * if consume is true, is equivalent to whether
2834  * or not the skb was consumed.
2835  */
2836 static bool ieee80211_prepare_and_rx_handle(struct ieee80211_rx_data *rx,
2837 					    struct sk_buff *skb, bool consume)
2838 {
2839 	struct ieee80211_local *local = rx->local;
2840 	struct ieee80211_sub_if_data *sdata = rx->sdata;
2841 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
2842 	struct ieee80211_hdr *hdr = (void *)skb->data;
2843 	int prepares;
2844 
2845 	rx->skb = skb;
2846 	status->rx_flags |= IEEE80211_RX_RA_MATCH;
2847 	prepares = prepare_for_handlers(rx, hdr);
2848 
2849 	if (!prepares)
2850 		return false;
2851 
2852 	if (!consume) {
2853 		skb = skb_copy(skb, GFP_ATOMIC);
2854 		if (!skb) {
2855 			if (net_ratelimit())
2856 				wiphy_debug(local->hw.wiphy,
2857 					"failed to copy skb for %s\n",
2858 					sdata->name);
2859 			return true;
2860 		}
2861 
2862 		rx->skb = skb;
2863 	}
2864 
2865 	ieee80211_invoke_rx_handlers(rx);
2866 	return true;
2867 }
2868 
2869 /*
2870  * This is the actual Rx frames handler. as it blongs to Rx path it must
2871  * be called with rcu_read_lock protection.
2872  */
2873 static void __ieee80211_rx_handle_packet(struct ieee80211_hw *hw,
2874 					 struct sk_buff *skb)
2875 {
2876 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
2877 	struct ieee80211_local *local = hw_to_local(hw);
2878 	struct ieee80211_sub_if_data *sdata;
2879 	struct ieee80211_hdr *hdr;
2880 	__le16 fc;
2881 	struct ieee80211_rx_data rx;
2882 	struct ieee80211_sub_if_data *prev;
2883 	struct sta_info *sta, *tmp, *prev_sta;
2884 	int err = 0;
2885 
2886 	fc = ((struct ieee80211_hdr *)skb->data)->frame_control;
2887 	memset(&rx, 0, sizeof(rx));
2888 	rx.skb = skb;
2889 	rx.local = local;
2890 
2891 	if (ieee80211_is_data(fc) || ieee80211_is_mgmt(fc))
2892 		local->dot11ReceivedFragmentCount++;
2893 
2894 	if (unlikely(test_bit(SCAN_HW_SCANNING, &local->scanning) ||
2895 		     test_bit(SCAN_SW_SCANNING, &local->scanning)))
2896 		status->rx_flags |= IEEE80211_RX_IN_SCAN;
2897 
2898 	if (ieee80211_is_mgmt(fc))
2899 		err = skb_linearize(skb);
2900 	else
2901 		err = !pskb_may_pull(skb, ieee80211_hdrlen(fc));
2902 
2903 	if (err) {
2904 		dev_kfree_skb(skb);
2905 		return;
2906 	}
2907 
2908 	hdr = (struct ieee80211_hdr *)skb->data;
2909 	ieee80211_parse_qos(&rx);
2910 	ieee80211_verify_alignment(&rx);
2911 
2912 	if (ieee80211_is_data(fc)) {
2913 		prev_sta = NULL;
2914 
2915 		for_each_sta_info_rx(local, hdr->addr2, sta, tmp) {
2916 			if (!prev_sta) {
2917 				prev_sta = sta;
2918 				continue;
2919 			}
2920 
2921 			rx.sta = prev_sta;
2922 			rx.sdata = prev_sta->sdata;
2923 			ieee80211_prepare_and_rx_handle(&rx, skb, false);
2924 
2925 			prev_sta = sta;
2926 		}
2927 
2928 		if (prev_sta) {
2929 			rx.sta = prev_sta;
2930 			rx.sdata = prev_sta->sdata;
2931 
2932 			if (ieee80211_prepare_and_rx_handle(&rx, skb, true))
2933 				return;
2934 			goto out;
2935 		}
2936 	}
2937 
2938 	prev = NULL;
2939 
2940 	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
2941 		if (!ieee80211_sdata_running(sdata))
2942 			continue;
2943 
2944 		if (sdata->vif.type == NL80211_IFTYPE_MONITOR ||
2945 		    sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
2946 			continue;
2947 
2948 		/*
2949 		 * frame is destined for this interface, but if it's
2950 		 * not also for the previous one we handle that after
2951 		 * the loop to avoid copying the SKB once too much
2952 		 */
2953 
2954 		if (!prev) {
2955 			prev = sdata;
2956 			continue;
2957 		}
2958 
2959 		rx.sta = sta_info_get_bss_rx(prev, hdr->addr2);
2960 		rx.sdata = prev;
2961 		ieee80211_prepare_and_rx_handle(&rx, skb, false);
2962 
2963 		prev = sdata;
2964 	}
2965 
2966 	if (prev) {
2967 		rx.sta = sta_info_get_bss_rx(prev, hdr->addr2);
2968 		rx.sdata = prev;
2969 
2970 		if (ieee80211_prepare_and_rx_handle(&rx, skb, true))
2971 			return;
2972 	}
2973 
2974  out:
2975 	dev_kfree_skb(skb);
2976 }
2977 
2978 /*
2979  * This is the receive path handler. It is called by a low level driver when an
2980  * 802.11 MPDU is received from the hardware.
2981  */
2982 void ieee80211_rx(struct ieee80211_hw *hw, struct sk_buff *skb)
2983 {
2984 	struct ieee80211_local *local = hw_to_local(hw);
2985 	struct ieee80211_rate *rate = NULL;
2986 	struct ieee80211_supported_band *sband;
2987 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
2988 
2989 	WARN_ON_ONCE(softirq_count() == 0);
2990 
2991 	if (WARN_ON(status->band < 0 ||
2992 		    status->band >= IEEE80211_NUM_BANDS))
2993 		goto drop;
2994 
2995 	sband = local->hw.wiphy->bands[status->band];
2996 	if (WARN_ON(!sband))
2997 		goto drop;
2998 
2999 	/*
3000 	 * If we're suspending, it is possible although not too likely
3001 	 * that we'd be receiving frames after having already partially
3002 	 * quiesced the stack. We can't process such frames then since
3003 	 * that might, for example, cause stations to be added or other
3004 	 * driver callbacks be invoked.
3005 	 */
3006 	if (unlikely(local->quiescing || local->suspended))
3007 		goto drop;
3008 
3009 	/*
3010 	 * The same happens when we're not even started,
3011 	 * but that's worth a warning.
3012 	 */
3013 	if (WARN_ON(!local->started))
3014 		goto drop;
3015 
3016 	if (likely(!(status->flag & RX_FLAG_FAILED_PLCP_CRC))) {
3017 		/*
3018 		 * Validate the rate, unless a PLCP error means that
3019 		 * we probably can't have a valid rate here anyway.
3020 		 */
3021 
3022 		if (status->flag & RX_FLAG_HT) {
3023 			/*
3024 			 * rate_idx is MCS index, which can be [0-76]
3025 			 * as documented on:
3026 			 *
3027 			 * http://wireless.kernel.org/en/developers/Documentation/ieee80211/802.11n
3028 			 *
3029 			 * Anything else would be some sort of driver or
3030 			 * hardware error. The driver should catch hardware
3031 			 * errors.
3032 			 */
3033 			if (WARN((status->rate_idx < 0 ||
3034 				 status->rate_idx > 76),
3035 				 "Rate marked as an HT rate but passed "
3036 				 "status->rate_idx is not "
3037 				 "an MCS index [0-76]: %d (0x%02x)\n",
3038 				 status->rate_idx,
3039 				 status->rate_idx))
3040 				goto drop;
3041 		} else {
3042 			if (WARN_ON(status->rate_idx < 0 ||
3043 				    status->rate_idx >= sband->n_bitrates))
3044 				goto drop;
3045 			rate = &sband->bitrates[status->rate_idx];
3046 		}
3047 	}
3048 
3049 	status->rx_flags = 0;
3050 
3051 	/*
3052 	 * key references and virtual interfaces are protected using RCU
3053 	 * and this requires that we are in a read-side RCU section during
3054 	 * receive processing
3055 	 */
3056 	rcu_read_lock();
3057 
3058 	/*
3059 	 * Frames with failed FCS/PLCP checksum are not returned,
3060 	 * all other frames are returned without radiotap header
3061 	 * if it was previously present.
3062 	 * Also, frames with less than 16 bytes are dropped.
3063 	 */
3064 	skb = ieee80211_rx_monitor(local, skb, rate);
3065 	if (!skb) {
3066 		rcu_read_unlock();
3067 		return;
3068 	}
3069 
3070 	ieee80211_tpt_led_trig_rx(local,
3071 			((struct ieee80211_hdr *)skb->data)->frame_control,
3072 			skb->len);
3073 	__ieee80211_rx_handle_packet(hw, skb);
3074 
3075 	rcu_read_unlock();
3076 
3077 	return;
3078  drop:
3079 	kfree_skb(skb);
3080 }
3081 EXPORT_SYMBOL(ieee80211_rx);
3082 
3083 /* This is a version of the rx handler that can be called from hard irq
3084  * context. Post the skb on the queue and schedule the tasklet */
3085 void ieee80211_rx_irqsafe(struct ieee80211_hw *hw, struct sk_buff *skb)
3086 {
3087 	struct ieee80211_local *local = hw_to_local(hw);
3088 
3089 	BUILD_BUG_ON(sizeof(struct ieee80211_rx_status) > sizeof(skb->cb));
3090 
3091 	skb->pkt_type = IEEE80211_RX_MSG;
3092 	skb_queue_tail(&local->skb_queue, skb);
3093 	tasklet_schedule(&local->tasklet);
3094 }
3095 EXPORT_SYMBOL(ieee80211_rx_irqsafe);
3096