xref: /openbmc/linux/net/mac80211/rx.c (revision 565d76cb)
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 <net/mac80211.h>
20 #include <net/ieee80211_radiotap.h>
21 
22 #include "ieee80211_i.h"
23 #include "driver-ops.h"
24 #include "led.h"
25 #include "mesh.h"
26 #include "wep.h"
27 #include "wpa.h"
28 #include "tkip.h"
29 #include "wme.h"
30 
31 /*
32  * monitor mode reception
33  *
34  * This function cleans up the SKB, i.e. it removes all the stuff
35  * only useful for monitoring.
36  */
37 static struct sk_buff *remove_monitor_info(struct ieee80211_local *local,
38 					   struct sk_buff *skb)
39 {
40 	if (local->hw.flags & IEEE80211_HW_RX_INCLUDES_FCS) {
41 		if (likely(skb->len > FCS_LEN))
42 			__pskb_trim(skb, skb->len - FCS_LEN);
43 		else {
44 			/* driver bug */
45 			WARN_ON(1);
46 			dev_kfree_skb(skb);
47 			skb = NULL;
48 		}
49 	}
50 
51 	return skb;
52 }
53 
54 static inline int should_drop_frame(struct sk_buff *skb,
55 				    int present_fcs_len)
56 {
57 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
58 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
59 
60 	if (status->flag & (RX_FLAG_FAILED_FCS_CRC | RX_FLAG_FAILED_PLCP_CRC))
61 		return 1;
62 	if (unlikely(skb->len < 16 + present_fcs_len))
63 		return 1;
64 	if (ieee80211_is_ctl(hdr->frame_control) &&
65 	    !ieee80211_is_pspoll(hdr->frame_control) &&
66 	    !ieee80211_is_back_req(hdr->frame_control))
67 		return 1;
68 	return 0;
69 }
70 
71 static int
72 ieee80211_rx_radiotap_len(struct ieee80211_local *local,
73 			  struct ieee80211_rx_status *status)
74 {
75 	int len;
76 
77 	/* always present fields */
78 	len = sizeof(struct ieee80211_radiotap_header) + 9;
79 
80 	if (status->flag & RX_FLAG_MACTIME_MPDU)
81 		len += 8;
82 	if (local->hw.flags & IEEE80211_HW_SIGNAL_DBM)
83 		len += 1;
84 
85 	if (len & 1) /* padding for RX_FLAGS if necessary */
86 		len++;
87 
88 	if (status->flag & RX_FLAG_HT) /* HT info */
89 		len += 3;
90 
91 	return len;
92 }
93 
94 /*
95  * ieee80211_add_rx_radiotap_header - add radiotap header
96  *
97  * add a radiotap header containing all the fields which the hardware provided.
98  */
99 static void
100 ieee80211_add_rx_radiotap_header(struct ieee80211_local *local,
101 				 struct sk_buff *skb,
102 				 struct ieee80211_rate *rate,
103 				 int rtap_len)
104 {
105 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
106 	struct ieee80211_radiotap_header *rthdr;
107 	unsigned char *pos;
108 	u16 rx_flags = 0;
109 
110 	rthdr = (struct ieee80211_radiotap_header *)skb_push(skb, rtap_len);
111 	memset(rthdr, 0, rtap_len);
112 
113 	/* radiotap header, set always present flags */
114 	rthdr->it_present =
115 		cpu_to_le32((1 << IEEE80211_RADIOTAP_FLAGS) |
116 			    (1 << IEEE80211_RADIOTAP_CHANNEL) |
117 			    (1 << IEEE80211_RADIOTAP_ANTENNA) |
118 			    (1 << IEEE80211_RADIOTAP_RX_FLAGS));
119 	rthdr->it_len = cpu_to_le16(rtap_len);
120 
121 	pos = (unsigned char *)(rthdr+1);
122 
123 	/* the order of the following fields is important */
124 
125 	/* IEEE80211_RADIOTAP_TSFT */
126 	if (status->flag & RX_FLAG_MACTIME_MPDU) {
127 		put_unaligned_le64(status->mactime, pos);
128 		rthdr->it_present |=
129 			cpu_to_le32(1 << IEEE80211_RADIOTAP_TSFT);
130 		pos += 8;
131 	}
132 
133 	/* IEEE80211_RADIOTAP_FLAGS */
134 	if (local->hw.flags & IEEE80211_HW_RX_INCLUDES_FCS)
135 		*pos |= IEEE80211_RADIOTAP_F_FCS;
136 	if (status->flag & (RX_FLAG_FAILED_FCS_CRC | RX_FLAG_FAILED_PLCP_CRC))
137 		*pos |= IEEE80211_RADIOTAP_F_BADFCS;
138 	if (status->flag & RX_FLAG_SHORTPRE)
139 		*pos |= IEEE80211_RADIOTAP_F_SHORTPRE;
140 	pos++;
141 
142 	/* IEEE80211_RADIOTAP_RATE */
143 	if (status->flag & RX_FLAG_HT) {
144 		/*
145 		 * MCS information is a separate field in radiotap,
146 		 * added below.
147 		 */
148 		*pos = 0;
149 	} else {
150 		rthdr->it_present |= cpu_to_le32(1 << IEEE80211_RADIOTAP_RATE);
151 		*pos = rate->bitrate / 5;
152 	}
153 	pos++;
154 
155 	/* IEEE80211_RADIOTAP_CHANNEL */
156 	put_unaligned_le16(status->freq, pos);
157 	pos += 2;
158 	if (status->band == IEEE80211_BAND_5GHZ)
159 		put_unaligned_le16(IEEE80211_CHAN_OFDM | IEEE80211_CHAN_5GHZ,
160 				   pos);
161 	else if (status->flag & RX_FLAG_HT)
162 		put_unaligned_le16(IEEE80211_CHAN_DYN | IEEE80211_CHAN_2GHZ,
163 				   pos);
164 	else if (rate->flags & IEEE80211_RATE_ERP_G)
165 		put_unaligned_le16(IEEE80211_CHAN_OFDM | IEEE80211_CHAN_2GHZ,
166 				   pos);
167 	else
168 		put_unaligned_le16(IEEE80211_CHAN_CCK | IEEE80211_CHAN_2GHZ,
169 				   pos);
170 	pos += 2;
171 
172 	/* IEEE80211_RADIOTAP_DBM_ANTSIGNAL */
173 	if (local->hw.flags & IEEE80211_HW_SIGNAL_DBM) {
174 		*pos = status->signal;
175 		rthdr->it_present |=
176 			cpu_to_le32(1 << IEEE80211_RADIOTAP_DBM_ANTSIGNAL);
177 		pos++;
178 	}
179 
180 	/* IEEE80211_RADIOTAP_LOCK_QUALITY is missing */
181 
182 	/* IEEE80211_RADIOTAP_ANTENNA */
183 	*pos = status->antenna;
184 	pos++;
185 
186 	/* IEEE80211_RADIOTAP_DB_ANTNOISE is not used */
187 
188 	/* IEEE80211_RADIOTAP_RX_FLAGS */
189 	/* ensure 2 byte alignment for the 2 byte field as required */
190 	if ((pos - (u8 *)rthdr) & 1)
191 		pos++;
192 	if (status->flag & RX_FLAG_FAILED_PLCP_CRC)
193 		rx_flags |= IEEE80211_RADIOTAP_F_RX_BADPLCP;
194 	put_unaligned_le16(rx_flags, pos);
195 	pos += 2;
196 
197 	if (status->flag & RX_FLAG_HT) {
198 		rthdr->it_present |= cpu_to_le32(1 << IEEE80211_RADIOTAP_MCS);
199 		*pos++ = IEEE80211_RADIOTAP_MCS_HAVE_MCS |
200 			 IEEE80211_RADIOTAP_MCS_HAVE_GI |
201 			 IEEE80211_RADIOTAP_MCS_HAVE_BW;
202 		*pos = 0;
203 		if (status->flag & RX_FLAG_SHORT_GI)
204 			*pos |= IEEE80211_RADIOTAP_MCS_SGI;
205 		if (status->flag & RX_FLAG_40MHZ)
206 			*pos |= IEEE80211_RADIOTAP_MCS_BW_40;
207 		pos++;
208 		*pos++ = status->rate_idx;
209 	}
210 }
211 
212 /*
213  * This function copies a received frame to all monitor interfaces and
214  * returns a cleaned-up SKB that no longer includes the FCS nor the
215  * radiotap header the driver might have added.
216  */
217 static struct sk_buff *
218 ieee80211_rx_monitor(struct ieee80211_local *local, struct sk_buff *origskb,
219 		     struct ieee80211_rate *rate)
220 {
221 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(origskb);
222 	struct ieee80211_sub_if_data *sdata;
223 	int needed_headroom = 0;
224 	struct sk_buff *skb, *skb2;
225 	struct net_device *prev_dev = NULL;
226 	int present_fcs_len = 0;
227 
228 	/*
229 	 * First, we may need to make a copy of the skb because
230 	 *  (1) we need to modify it for radiotap (if not present), and
231 	 *  (2) the other RX handlers will modify the skb we got.
232 	 *
233 	 * We don't need to, of course, if we aren't going to return
234 	 * the SKB because it has a bad FCS/PLCP checksum.
235 	 */
236 
237 	/* room for the radiotap header based on driver features */
238 	needed_headroom = ieee80211_rx_radiotap_len(local, status);
239 
240 	if (local->hw.flags & IEEE80211_HW_RX_INCLUDES_FCS)
241 		present_fcs_len = FCS_LEN;
242 
243 	/* make sure hdr->frame_control is on the linear part */
244 	if (!pskb_may_pull(origskb, 2)) {
245 		dev_kfree_skb(origskb);
246 		return NULL;
247 	}
248 
249 	if (!local->monitors) {
250 		if (should_drop_frame(origskb, present_fcs_len)) {
251 			dev_kfree_skb(origskb);
252 			return NULL;
253 		}
254 
255 		return remove_monitor_info(local, origskb);
256 	}
257 
258 	if (should_drop_frame(origskb, present_fcs_len)) {
259 		/* only need to expand headroom if necessary */
260 		skb = origskb;
261 		origskb = NULL;
262 
263 		/*
264 		 * This shouldn't trigger often because most devices have an
265 		 * RX header they pull before we get here, and that should
266 		 * be big enough for our radiotap information. We should
267 		 * probably export the length to drivers so that we can have
268 		 * them allocate enough headroom to start with.
269 		 */
270 		if (skb_headroom(skb) < needed_headroom &&
271 		    pskb_expand_head(skb, needed_headroom, 0, GFP_ATOMIC)) {
272 			dev_kfree_skb(skb);
273 			return NULL;
274 		}
275 	} else {
276 		/*
277 		 * Need to make a copy and possibly remove radiotap header
278 		 * and FCS from the original.
279 		 */
280 		skb = skb_copy_expand(origskb, needed_headroom, 0, GFP_ATOMIC);
281 
282 		origskb = remove_monitor_info(local, origskb);
283 
284 		if (!skb)
285 			return origskb;
286 	}
287 
288 	/* prepend radiotap information */
289 	ieee80211_add_rx_radiotap_header(local, skb, rate, needed_headroom);
290 
291 	skb_reset_mac_header(skb);
292 	skb->ip_summed = CHECKSUM_UNNECESSARY;
293 	skb->pkt_type = PACKET_OTHERHOST;
294 	skb->protocol = htons(ETH_P_802_2);
295 
296 	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
297 		if (sdata->vif.type != NL80211_IFTYPE_MONITOR)
298 			continue;
299 
300 		if (sdata->u.mntr_flags & MONITOR_FLAG_COOK_FRAMES)
301 			continue;
302 
303 		if (!ieee80211_sdata_running(sdata))
304 			continue;
305 
306 		if (prev_dev) {
307 			skb2 = skb_clone(skb, GFP_ATOMIC);
308 			if (skb2) {
309 				skb2->dev = prev_dev;
310 				netif_receive_skb(skb2);
311 			}
312 		}
313 
314 		prev_dev = sdata->dev;
315 		sdata->dev->stats.rx_packets++;
316 		sdata->dev->stats.rx_bytes += skb->len;
317 	}
318 
319 	if (prev_dev) {
320 		skb->dev = prev_dev;
321 		netif_receive_skb(skb);
322 	} else
323 		dev_kfree_skb(skb);
324 
325 	return origskb;
326 }
327 
328 
329 static void ieee80211_parse_qos(struct ieee80211_rx_data *rx)
330 {
331 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
332 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
333 	int tid;
334 
335 	/* does the frame have a qos control field? */
336 	if (ieee80211_is_data_qos(hdr->frame_control)) {
337 		u8 *qc = ieee80211_get_qos_ctl(hdr);
338 		/* frame has qos control */
339 		tid = *qc & IEEE80211_QOS_CTL_TID_MASK;
340 		if (*qc & IEEE80211_QOS_CONTROL_A_MSDU_PRESENT)
341 			status->rx_flags |= IEEE80211_RX_AMSDU;
342 	} else {
343 		/*
344 		 * IEEE 802.11-2007, 7.1.3.4.1 ("Sequence Number field"):
345 		 *
346 		 *	Sequence numbers for management frames, QoS data
347 		 *	frames with a broadcast/multicast address in the
348 		 *	Address 1 field, and all non-QoS data frames sent
349 		 *	by QoS STAs are assigned using an additional single
350 		 *	modulo-4096 counter, [...]
351 		 *
352 		 * We also use that counter for non-QoS STAs.
353 		 */
354 		tid = NUM_RX_DATA_QUEUES - 1;
355 	}
356 
357 	rx->queue = tid;
358 	/* Set skb->priority to 1d tag if highest order bit of TID is not set.
359 	 * For now, set skb->priority to 0 for other cases. */
360 	rx->skb->priority = (tid > 7) ? 0 : tid;
361 }
362 
363 /**
364  * DOC: Packet alignment
365  *
366  * Drivers always need to pass packets that are aligned to two-byte boundaries
367  * to the stack.
368  *
369  * Additionally, should, if possible, align the payload data in a way that
370  * guarantees that the contained IP header is aligned to a four-byte
371  * boundary. In the case of regular frames, this simply means aligning the
372  * payload to a four-byte boundary (because either the IP header is directly
373  * contained, or IV/RFC1042 headers that have a length divisible by four are
374  * in front of it).  If the payload data is not properly aligned and the
375  * architecture doesn't support efficient unaligned operations, mac80211
376  * will align the data.
377  *
378  * With A-MSDU frames, however, the payload data address must yield two modulo
379  * four because there are 14-byte 802.3 headers within the A-MSDU frames that
380  * push the IP header further back to a multiple of four again. Thankfully, the
381  * specs were sane enough this time around to require padding each A-MSDU
382  * subframe to a length that is a multiple of four.
383  *
384  * Padding like Atheros hardware adds which is inbetween the 802.11 header and
385  * the payload is not supported, the driver is required to move the 802.11
386  * header to be directly in front of the payload in that case.
387  */
388 static void ieee80211_verify_alignment(struct ieee80211_rx_data *rx)
389 {
390 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG
391 	WARN_ONCE((unsigned long)rx->skb->data & 1,
392 		  "unaligned packet at 0x%p\n", rx->skb->data);
393 #endif
394 }
395 
396 
397 /* rx handlers */
398 
399 static ieee80211_rx_result debug_noinline
400 ieee80211_rx_h_passive_scan(struct ieee80211_rx_data *rx)
401 {
402 	struct ieee80211_local *local = rx->local;
403 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
404 	struct sk_buff *skb = rx->skb;
405 
406 	if (likely(!(status->rx_flags & IEEE80211_RX_IN_SCAN)))
407 		return RX_CONTINUE;
408 
409 	if (test_bit(SCAN_HW_SCANNING, &local->scanning) ||
410 	    test_bit(SCAN_SW_SCANNING, &local->scanning))
411 		return ieee80211_scan_rx(rx->sdata, skb);
412 
413 	/* scanning finished during invoking of handlers */
414 	I802_DEBUG_INC(local->rx_handlers_drop_passive_scan);
415 	return RX_DROP_UNUSABLE;
416 }
417 
418 
419 static int ieee80211_is_unicast_robust_mgmt_frame(struct sk_buff *skb)
420 {
421 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
422 
423 	if (skb->len < 24 || is_multicast_ether_addr(hdr->addr1))
424 		return 0;
425 
426 	return ieee80211_is_robust_mgmt_frame(hdr);
427 }
428 
429 
430 static int ieee80211_is_multicast_robust_mgmt_frame(struct sk_buff *skb)
431 {
432 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
433 
434 	if (skb->len < 24 || !is_multicast_ether_addr(hdr->addr1))
435 		return 0;
436 
437 	return ieee80211_is_robust_mgmt_frame(hdr);
438 }
439 
440 
441 /* Get the BIP key index from MMIE; return -1 if this is not a BIP frame */
442 static int ieee80211_get_mmie_keyidx(struct sk_buff *skb)
443 {
444 	struct ieee80211_mgmt *hdr = (struct ieee80211_mgmt *) skb->data;
445 	struct ieee80211_mmie *mmie;
446 
447 	if (skb->len < 24 + sizeof(*mmie) ||
448 	    !is_multicast_ether_addr(hdr->da))
449 		return -1;
450 
451 	if (!ieee80211_is_robust_mgmt_frame((struct ieee80211_hdr *) hdr))
452 		return -1; /* not a robust management frame */
453 
454 	mmie = (struct ieee80211_mmie *)
455 		(skb->data + skb->len - sizeof(*mmie));
456 	if (mmie->element_id != WLAN_EID_MMIE ||
457 	    mmie->length != sizeof(*mmie) - 2)
458 		return -1;
459 
460 	return le16_to_cpu(mmie->key_id);
461 }
462 
463 
464 static ieee80211_rx_result
465 ieee80211_rx_mesh_check(struct ieee80211_rx_data *rx)
466 {
467 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
468 	unsigned int hdrlen = ieee80211_hdrlen(hdr->frame_control);
469 	char *dev_addr = rx->sdata->vif.addr;
470 
471 	if (ieee80211_is_data(hdr->frame_control)) {
472 		if (is_multicast_ether_addr(hdr->addr1)) {
473 			if (ieee80211_has_tods(hdr->frame_control) ||
474 				!ieee80211_has_fromds(hdr->frame_control))
475 				return RX_DROP_MONITOR;
476 			if (memcmp(hdr->addr3, dev_addr, ETH_ALEN) == 0)
477 				return RX_DROP_MONITOR;
478 		} else {
479 			if (!ieee80211_has_a4(hdr->frame_control))
480 				return RX_DROP_MONITOR;
481 			if (memcmp(hdr->addr4, dev_addr, ETH_ALEN) == 0)
482 				return RX_DROP_MONITOR;
483 		}
484 	}
485 
486 	/* If there is not an established peer link and this is not a peer link
487 	 * establisment frame, beacon or probe, drop the frame.
488 	 */
489 
490 	if (!rx->sta || sta_plink_state(rx->sta) != PLINK_ESTAB) {
491 		struct ieee80211_mgmt *mgmt;
492 
493 		if (!ieee80211_is_mgmt(hdr->frame_control))
494 			return RX_DROP_MONITOR;
495 
496 		if (ieee80211_is_action(hdr->frame_control)) {
497 			mgmt = (struct ieee80211_mgmt *)hdr;
498 			if (mgmt->u.action.category != WLAN_CATEGORY_MESH_PLINK)
499 				return RX_DROP_MONITOR;
500 			return RX_CONTINUE;
501 		}
502 
503 		if (ieee80211_is_probe_req(hdr->frame_control) ||
504 		    ieee80211_is_probe_resp(hdr->frame_control) ||
505 		    ieee80211_is_beacon(hdr->frame_control))
506 			return RX_CONTINUE;
507 
508 		return RX_DROP_MONITOR;
509 
510 	}
511 
512 #define msh_h_get(h, l) ((struct ieee80211s_hdr *) ((u8 *)h + l))
513 
514 	if (ieee80211_is_data(hdr->frame_control) &&
515 	    is_multicast_ether_addr(hdr->addr1) &&
516 	    mesh_rmc_check(hdr->addr3, msh_h_get(hdr, hdrlen), rx->sdata))
517 		return RX_DROP_MONITOR;
518 #undef msh_h_get
519 
520 	return RX_CONTINUE;
521 }
522 
523 #define SEQ_MODULO 0x1000
524 #define SEQ_MASK   0xfff
525 
526 static inline int seq_less(u16 sq1, u16 sq2)
527 {
528 	return ((sq1 - sq2) & SEQ_MASK) > (SEQ_MODULO >> 1);
529 }
530 
531 static inline u16 seq_inc(u16 sq)
532 {
533 	return (sq + 1) & SEQ_MASK;
534 }
535 
536 static inline u16 seq_sub(u16 sq1, u16 sq2)
537 {
538 	return (sq1 - sq2) & SEQ_MASK;
539 }
540 
541 
542 static void ieee80211_release_reorder_frame(struct ieee80211_hw *hw,
543 					    struct tid_ampdu_rx *tid_agg_rx,
544 					    int index)
545 {
546 	struct ieee80211_local *local = hw_to_local(hw);
547 	struct sk_buff *skb = tid_agg_rx->reorder_buf[index];
548 	struct ieee80211_rx_status *status;
549 
550 	lockdep_assert_held(&tid_agg_rx->reorder_lock);
551 
552 	if (!skb)
553 		goto no_frame;
554 
555 	/* release the frame from the reorder ring buffer */
556 	tid_agg_rx->stored_mpdu_num--;
557 	tid_agg_rx->reorder_buf[index] = NULL;
558 	status = IEEE80211_SKB_RXCB(skb);
559 	status->rx_flags |= IEEE80211_RX_DEFERRED_RELEASE;
560 	skb_queue_tail(&local->rx_skb_queue, skb);
561 
562 no_frame:
563 	tid_agg_rx->head_seq_num = seq_inc(tid_agg_rx->head_seq_num);
564 }
565 
566 static void ieee80211_release_reorder_frames(struct ieee80211_hw *hw,
567 					     struct tid_ampdu_rx *tid_agg_rx,
568 					     u16 head_seq_num)
569 {
570 	int index;
571 
572 	lockdep_assert_held(&tid_agg_rx->reorder_lock);
573 
574 	while (seq_less(tid_agg_rx->head_seq_num, head_seq_num)) {
575 		index = seq_sub(tid_agg_rx->head_seq_num, tid_agg_rx->ssn) %
576 							tid_agg_rx->buf_size;
577 		ieee80211_release_reorder_frame(hw, tid_agg_rx, index);
578 	}
579 }
580 
581 /*
582  * Timeout (in jiffies) for skb's that are waiting in the RX reorder buffer. If
583  * the skb was added to the buffer longer than this time ago, the earlier
584  * frames that have not yet been received are assumed to be lost and the skb
585  * can be released for processing. This may also release other skb's from the
586  * reorder buffer if there are no additional gaps between the frames.
587  *
588  * Callers must hold tid_agg_rx->reorder_lock.
589  */
590 #define HT_RX_REORDER_BUF_TIMEOUT (HZ / 10)
591 
592 static void ieee80211_sta_reorder_release(struct ieee80211_hw *hw,
593 					  struct tid_ampdu_rx *tid_agg_rx)
594 {
595 	int index, j;
596 
597 	lockdep_assert_held(&tid_agg_rx->reorder_lock);
598 
599 	/* release the buffer until next missing frame */
600 	index = seq_sub(tid_agg_rx->head_seq_num, tid_agg_rx->ssn) %
601 						tid_agg_rx->buf_size;
602 	if (!tid_agg_rx->reorder_buf[index] &&
603 	    tid_agg_rx->stored_mpdu_num > 1) {
604 		/*
605 		 * No buffers ready to be released, but check whether any
606 		 * frames in the reorder buffer have timed out.
607 		 */
608 		int skipped = 1;
609 		for (j = (index + 1) % tid_agg_rx->buf_size; j != index;
610 		     j = (j + 1) % tid_agg_rx->buf_size) {
611 			if (!tid_agg_rx->reorder_buf[j]) {
612 				skipped++;
613 				continue;
614 			}
615 			if (!time_after(jiffies, tid_agg_rx->reorder_time[j] +
616 					HT_RX_REORDER_BUF_TIMEOUT))
617 				goto set_release_timer;
618 
619 #ifdef CONFIG_MAC80211_HT_DEBUG
620 			if (net_ratelimit())
621 				wiphy_debug(hw->wiphy,
622 					    "release an RX reorder frame due to timeout on earlier frames\n");
623 #endif
624 			ieee80211_release_reorder_frame(hw, tid_agg_rx, j);
625 
626 			/*
627 			 * Increment the head seq# also for the skipped slots.
628 			 */
629 			tid_agg_rx->head_seq_num =
630 				(tid_agg_rx->head_seq_num + skipped) & SEQ_MASK;
631 			skipped = 0;
632 		}
633 	} else while (tid_agg_rx->reorder_buf[index]) {
634 		ieee80211_release_reorder_frame(hw, tid_agg_rx, index);
635 		index =	seq_sub(tid_agg_rx->head_seq_num, tid_agg_rx->ssn) %
636 							tid_agg_rx->buf_size;
637 	}
638 
639 	if (tid_agg_rx->stored_mpdu_num) {
640 		j = index = seq_sub(tid_agg_rx->head_seq_num,
641 				    tid_agg_rx->ssn) % tid_agg_rx->buf_size;
642 
643 		for (; j != (index - 1) % tid_agg_rx->buf_size;
644 		     j = (j + 1) % tid_agg_rx->buf_size) {
645 			if (tid_agg_rx->reorder_buf[j])
646 				break;
647 		}
648 
649  set_release_timer:
650 
651 		mod_timer(&tid_agg_rx->reorder_timer,
652 			  tid_agg_rx->reorder_time[j] +
653 			  HT_RX_REORDER_BUF_TIMEOUT);
654 	} else {
655 		del_timer(&tid_agg_rx->reorder_timer);
656 	}
657 }
658 
659 /*
660  * As this function belongs to the RX path it must be under
661  * rcu_read_lock protection. It returns false if the frame
662  * can be processed immediately, true if it was consumed.
663  */
664 static bool ieee80211_sta_manage_reorder_buf(struct ieee80211_hw *hw,
665 					     struct tid_ampdu_rx *tid_agg_rx,
666 					     struct sk_buff *skb)
667 {
668 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
669 	u16 sc = le16_to_cpu(hdr->seq_ctrl);
670 	u16 mpdu_seq_num = (sc & IEEE80211_SCTL_SEQ) >> 4;
671 	u16 head_seq_num, buf_size;
672 	int index;
673 	bool ret = true;
674 
675 	spin_lock(&tid_agg_rx->reorder_lock);
676 
677 	buf_size = tid_agg_rx->buf_size;
678 	head_seq_num = tid_agg_rx->head_seq_num;
679 
680 	/* frame with out of date sequence number */
681 	if (seq_less(mpdu_seq_num, head_seq_num)) {
682 		dev_kfree_skb(skb);
683 		goto out;
684 	}
685 
686 	/*
687 	 * If frame the sequence number exceeds our buffering window
688 	 * size release some previous frames to make room for this one.
689 	 */
690 	if (!seq_less(mpdu_seq_num, head_seq_num + buf_size)) {
691 		head_seq_num = seq_inc(seq_sub(mpdu_seq_num, buf_size));
692 		/* release stored frames up to new head to stack */
693 		ieee80211_release_reorder_frames(hw, tid_agg_rx, head_seq_num);
694 	}
695 
696 	/* Now the new frame is always in the range of the reordering buffer */
697 
698 	index = seq_sub(mpdu_seq_num, tid_agg_rx->ssn) % tid_agg_rx->buf_size;
699 
700 	/* check if we already stored this frame */
701 	if (tid_agg_rx->reorder_buf[index]) {
702 		dev_kfree_skb(skb);
703 		goto out;
704 	}
705 
706 	/*
707 	 * If the current MPDU is in the right order and nothing else
708 	 * is stored we can process it directly, no need to buffer it.
709 	 */
710 	if (mpdu_seq_num == tid_agg_rx->head_seq_num &&
711 	    tid_agg_rx->stored_mpdu_num == 0) {
712 		tid_agg_rx->head_seq_num = seq_inc(tid_agg_rx->head_seq_num);
713 		ret = false;
714 		goto out;
715 	}
716 
717 	/* put the frame in the reordering buffer */
718 	tid_agg_rx->reorder_buf[index] = skb;
719 	tid_agg_rx->reorder_time[index] = jiffies;
720 	tid_agg_rx->stored_mpdu_num++;
721 	ieee80211_sta_reorder_release(hw, tid_agg_rx);
722 
723  out:
724 	spin_unlock(&tid_agg_rx->reorder_lock);
725 	return ret;
726 }
727 
728 /*
729  * Reorder MPDUs from A-MPDUs, keeping them on a buffer. Returns
730  * true if the MPDU was buffered, false if it should be processed.
731  */
732 static void ieee80211_rx_reorder_ampdu(struct ieee80211_rx_data *rx)
733 {
734 	struct sk_buff *skb = rx->skb;
735 	struct ieee80211_local *local = rx->local;
736 	struct ieee80211_hw *hw = &local->hw;
737 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
738 	struct sta_info *sta = rx->sta;
739 	struct tid_ampdu_rx *tid_agg_rx;
740 	u16 sc;
741 	int tid;
742 
743 	if (!ieee80211_is_data_qos(hdr->frame_control))
744 		goto dont_reorder;
745 
746 	/*
747 	 * filter the QoS data rx stream according to
748 	 * STA/TID and check if this STA/TID is on aggregation
749 	 */
750 
751 	if (!sta)
752 		goto dont_reorder;
753 
754 	tid = *ieee80211_get_qos_ctl(hdr) & IEEE80211_QOS_CTL_TID_MASK;
755 
756 	tid_agg_rx = rcu_dereference(sta->ampdu_mlme.tid_rx[tid]);
757 	if (!tid_agg_rx)
758 		goto dont_reorder;
759 
760 	/* qos null data frames are excluded */
761 	if (unlikely(hdr->frame_control & cpu_to_le16(IEEE80211_STYPE_NULLFUNC)))
762 		goto dont_reorder;
763 
764 	/* new, potentially un-ordered, ampdu frame - process it */
765 
766 	/* reset session timer */
767 	if (tid_agg_rx->timeout)
768 		mod_timer(&tid_agg_rx->session_timer,
769 			  TU_TO_EXP_TIME(tid_agg_rx->timeout));
770 
771 	/* if this mpdu is fragmented - terminate rx aggregation session */
772 	sc = le16_to_cpu(hdr->seq_ctrl);
773 	if (sc & IEEE80211_SCTL_FRAG) {
774 		skb->pkt_type = IEEE80211_SDATA_QUEUE_TYPE_FRAME;
775 		skb_queue_tail(&rx->sdata->skb_queue, skb);
776 		ieee80211_queue_work(&local->hw, &rx->sdata->work);
777 		return;
778 	}
779 
780 	/*
781 	 * No locking needed -- we will only ever process one
782 	 * RX packet at a time, and thus own tid_agg_rx. All
783 	 * other code manipulating it needs to (and does) make
784 	 * sure that we cannot get to it any more before doing
785 	 * anything with it.
786 	 */
787 	if (ieee80211_sta_manage_reorder_buf(hw, tid_agg_rx, skb))
788 		return;
789 
790  dont_reorder:
791 	skb_queue_tail(&local->rx_skb_queue, skb);
792 }
793 
794 static ieee80211_rx_result debug_noinline
795 ieee80211_rx_h_check(struct ieee80211_rx_data *rx)
796 {
797 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
798 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
799 
800 	/* Drop duplicate 802.11 retransmissions (IEEE 802.11 Chap. 9.2.9) */
801 	if (rx->sta && !is_multicast_ether_addr(hdr->addr1)) {
802 		if (unlikely(ieee80211_has_retry(hdr->frame_control) &&
803 			     rx->sta->last_seq_ctrl[rx->queue] ==
804 			     hdr->seq_ctrl)) {
805 			if (status->rx_flags & IEEE80211_RX_RA_MATCH) {
806 				rx->local->dot11FrameDuplicateCount++;
807 				rx->sta->num_duplicates++;
808 			}
809 			return RX_DROP_UNUSABLE;
810 		} else
811 			rx->sta->last_seq_ctrl[rx->queue] = hdr->seq_ctrl;
812 	}
813 
814 	if (unlikely(rx->skb->len < 16)) {
815 		I802_DEBUG_INC(rx->local->rx_handlers_drop_short);
816 		return RX_DROP_MONITOR;
817 	}
818 
819 	/* Drop disallowed frame classes based on STA auth/assoc state;
820 	 * IEEE 802.11, Chap 5.5.
821 	 *
822 	 * mac80211 filters only based on association state, i.e. it drops
823 	 * Class 3 frames from not associated stations. hostapd sends
824 	 * deauth/disassoc frames when needed. In addition, hostapd is
825 	 * responsible for filtering on both auth and assoc states.
826 	 */
827 
828 	if (ieee80211_vif_is_mesh(&rx->sdata->vif))
829 		return ieee80211_rx_mesh_check(rx);
830 
831 	if (unlikely((ieee80211_is_data(hdr->frame_control) ||
832 		      ieee80211_is_pspoll(hdr->frame_control)) &&
833 		     rx->sdata->vif.type != NL80211_IFTYPE_ADHOC &&
834 		     rx->sdata->vif.type != NL80211_IFTYPE_WDS &&
835 		     (!rx->sta || !test_sta_flags(rx->sta, WLAN_STA_ASSOC))))
836 		return RX_DROP_MONITOR;
837 
838 	return RX_CONTINUE;
839 }
840 
841 
842 static ieee80211_rx_result debug_noinline
843 ieee80211_rx_h_decrypt(struct ieee80211_rx_data *rx)
844 {
845 	struct sk_buff *skb = rx->skb;
846 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
847 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
848 	int keyidx;
849 	int hdrlen;
850 	ieee80211_rx_result result = RX_DROP_UNUSABLE;
851 	struct ieee80211_key *sta_ptk = NULL;
852 	int mmie_keyidx = -1;
853 	__le16 fc;
854 
855 	/*
856 	 * Key selection 101
857 	 *
858 	 * There are four types of keys:
859 	 *  - GTK (group keys)
860 	 *  - IGTK (group keys for management frames)
861 	 *  - PTK (pairwise keys)
862 	 *  - STK (station-to-station pairwise keys)
863 	 *
864 	 * When selecting a key, we have to distinguish between multicast
865 	 * (including broadcast) and unicast frames, the latter can only
866 	 * use PTKs and STKs while the former always use GTKs and IGTKs.
867 	 * Unless, of course, actual WEP keys ("pre-RSNA") are used, then
868 	 * unicast frames can also use key indices like GTKs. Hence, if we
869 	 * don't have a PTK/STK we check the key index for a WEP key.
870 	 *
871 	 * Note that in a regular BSS, multicast frames are sent by the
872 	 * AP only, associated stations unicast the frame to the AP first
873 	 * which then multicasts it on their behalf.
874 	 *
875 	 * There is also a slight problem in IBSS mode: GTKs are negotiated
876 	 * with each station, that is something we don't currently handle.
877 	 * The spec seems to expect that one negotiates the same key with
878 	 * every station but there's no such requirement; VLANs could be
879 	 * possible.
880 	 */
881 
882 	/*
883 	 * No point in finding a key and decrypting if the frame is neither
884 	 * addressed to us nor a multicast frame.
885 	 */
886 	if (!(status->rx_flags & IEEE80211_RX_RA_MATCH))
887 		return RX_CONTINUE;
888 
889 	/* start without a key */
890 	rx->key = NULL;
891 
892 	if (rx->sta)
893 		sta_ptk = rcu_dereference(rx->sta->ptk);
894 
895 	fc = hdr->frame_control;
896 
897 	if (!ieee80211_has_protected(fc))
898 		mmie_keyidx = ieee80211_get_mmie_keyidx(rx->skb);
899 
900 	if (!is_multicast_ether_addr(hdr->addr1) && sta_ptk) {
901 		rx->key = sta_ptk;
902 		if ((status->flag & RX_FLAG_DECRYPTED) &&
903 		    (status->flag & RX_FLAG_IV_STRIPPED))
904 			return RX_CONTINUE;
905 		/* Skip decryption if the frame is not protected. */
906 		if (!ieee80211_has_protected(fc))
907 			return RX_CONTINUE;
908 	} else if (mmie_keyidx >= 0) {
909 		/* Broadcast/multicast robust management frame / BIP */
910 		if ((status->flag & RX_FLAG_DECRYPTED) &&
911 		    (status->flag & RX_FLAG_IV_STRIPPED))
912 			return RX_CONTINUE;
913 
914 		if (mmie_keyidx < NUM_DEFAULT_KEYS ||
915 		    mmie_keyidx >= NUM_DEFAULT_KEYS + NUM_DEFAULT_MGMT_KEYS)
916 			return RX_DROP_MONITOR; /* unexpected BIP keyidx */
917 		if (rx->sta)
918 			rx->key = rcu_dereference(rx->sta->gtk[mmie_keyidx]);
919 		if (!rx->key)
920 			rx->key = rcu_dereference(rx->sdata->keys[mmie_keyidx]);
921 	} else if (!ieee80211_has_protected(fc)) {
922 		/*
923 		 * The frame was not protected, so skip decryption. However, we
924 		 * need to set rx->key if there is a key that could have been
925 		 * used so that the frame may be dropped if encryption would
926 		 * have been expected.
927 		 */
928 		struct ieee80211_key *key = NULL;
929 		struct ieee80211_sub_if_data *sdata = rx->sdata;
930 		int i;
931 
932 		if (ieee80211_is_mgmt(fc) &&
933 		    is_multicast_ether_addr(hdr->addr1) &&
934 		    (key = rcu_dereference(rx->sdata->default_mgmt_key)))
935 			rx->key = key;
936 		else {
937 			if (rx->sta) {
938 				for (i = 0; i < NUM_DEFAULT_KEYS; i++) {
939 					key = rcu_dereference(rx->sta->gtk[i]);
940 					if (key)
941 						break;
942 				}
943 			}
944 			if (!key) {
945 				for (i = 0; i < NUM_DEFAULT_KEYS; i++) {
946 					key = rcu_dereference(sdata->keys[i]);
947 					if (key)
948 						break;
949 				}
950 			}
951 			if (key)
952 				rx->key = key;
953 		}
954 		return RX_CONTINUE;
955 	} else {
956 		u8 keyid;
957 		/*
958 		 * The device doesn't give us the IV so we won't be
959 		 * able to look up the key. That's ok though, we
960 		 * don't need to decrypt the frame, we just won't
961 		 * be able to keep statistics accurate.
962 		 * Except for key threshold notifications, should
963 		 * we somehow allow the driver to tell us which key
964 		 * the hardware used if this flag is set?
965 		 */
966 		if ((status->flag & RX_FLAG_DECRYPTED) &&
967 		    (status->flag & RX_FLAG_IV_STRIPPED))
968 			return RX_CONTINUE;
969 
970 		hdrlen = ieee80211_hdrlen(fc);
971 
972 		if (rx->skb->len < 8 + hdrlen)
973 			return RX_DROP_UNUSABLE; /* TODO: count this? */
974 
975 		/*
976 		 * no need to call ieee80211_wep_get_keyidx,
977 		 * it verifies a bunch of things we've done already
978 		 */
979 		skb_copy_bits(rx->skb, hdrlen + 3, &keyid, 1);
980 		keyidx = keyid >> 6;
981 
982 		/* check per-station GTK first, if multicast packet */
983 		if (is_multicast_ether_addr(hdr->addr1) && rx->sta)
984 			rx->key = rcu_dereference(rx->sta->gtk[keyidx]);
985 
986 		/* if not found, try default key */
987 		if (!rx->key) {
988 			rx->key = rcu_dereference(rx->sdata->keys[keyidx]);
989 
990 			/*
991 			 * RSNA-protected unicast frames should always be
992 			 * sent with pairwise or station-to-station keys,
993 			 * but for WEP we allow using a key index as well.
994 			 */
995 			if (rx->key &&
996 			    rx->key->conf.cipher != WLAN_CIPHER_SUITE_WEP40 &&
997 			    rx->key->conf.cipher != WLAN_CIPHER_SUITE_WEP104 &&
998 			    !is_multicast_ether_addr(hdr->addr1))
999 				rx->key = NULL;
1000 		}
1001 	}
1002 
1003 	if (rx->key) {
1004 		rx->key->tx_rx_count++;
1005 		/* TODO: add threshold stuff again */
1006 	} else {
1007 		return RX_DROP_MONITOR;
1008 	}
1009 
1010 	if (skb_linearize(rx->skb))
1011 		return RX_DROP_UNUSABLE;
1012 	/* the hdr variable is invalid now! */
1013 
1014 	switch (rx->key->conf.cipher) {
1015 	case WLAN_CIPHER_SUITE_WEP40:
1016 	case WLAN_CIPHER_SUITE_WEP104:
1017 		/* Check for weak IVs if possible */
1018 		if (rx->sta && ieee80211_is_data(fc) &&
1019 		    (!(status->flag & RX_FLAG_IV_STRIPPED) ||
1020 		     !(status->flag & RX_FLAG_DECRYPTED)) &&
1021 		    ieee80211_wep_is_weak_iv(rx->skb, rx->key))
1022 			rx->sta->wep_weak_iv_count++;
1023 
1024 		result = ieee80211_crypto_wep_decrypt(rx);
1025 		break;
1026 	case WLAN_CIPHER_SUITE_TKIP:
1027 		result = ieee80211_crypto_tkip_decrypt(rx);
1028 		break;
1029 	case WLAN_CIPHER_SUITE_CCMP:
1030 		result = ieee80211_crypto_ccmp_decrypt(rx);
1031 		break;
1032 	case WLAN_CIPHER_SUITE_AES_CMAC:
1033 		result = ieee80211_crypto_aes_cmac_decrypt(rx);
1034 		break;
1035 	default:
1036 		/*
1037 		 * We can reach here only with HW-only algorithms
1038 		 * but why didn't it decrypt the frame?!
1039 		 */
1040 		return RX_DROP_UNUSABLE;
1041 	}
1042 
1043 	/* either the frame has been decrypted or will be dropped */
1044 	status->flag |= RX_FLAG_DECRYPTED;
1045 
1046 	return result;
1047 }
1048 
1049 static ieee80211_rx_result debug_noinline
1050 ieee80211_rx_h_check_more_data(struct ieee80211_rx_data *rx)
1051 {
1052 	struct ieee80211_local *local;
1053 	struct ieee80211_hdr *hdr;
1054 	struct sk_buff *skb;
1055 
1056 	local = rx->local;
1057 	skb = rx->skb;
1058 	hdr = (struct ieee80211_hdr *) skb->data;
1059 
1060 	if (!local->pspolling)
1061 		return RX_CONTINUE;
1062 
1063 	if (!ieee80211_has_fromds(hdr->frame_control))
1064 		/* this is not from AP */
1065 		return RX_CONTINUE;
1066 
1067 	if (!ieee80211_is_data(hdr->frame_control))
1068 		return RX_CONTINUE;
1069 
1070 	if (!ieee80211_has_moredata(hdr->frame_control)) {
1071 		/* AP has no more frames buffered for us */
1072 		local->pspolling = false;
1073 		return RX_CONTINUE;
1074 	}
1075 
1076 	/* more data bit is set, let's request a new frame from the AP */
1077 	ieee80211_send_pspoll(local, rx->sdata);
1078 
1079 	return RX_CONTINUE;
1080 }
1081 
1082 static void ap_sta_ps_start(struct sta_info *sta)
1083 {
1084 	struct ieee80211_sub_if_data *sdata = sta->sdata;
1085 	struct ieee80211_local *local = sdata->local;
1086 
1087 	atomic_inc(&sdata->bss->num_sta_ps);
1088 	set_sta_flags(sta, WLAN_STA_PS_STA);
1089 	if (!(local->hw.flags & IEEE80211_HW_AP_LINK_PS))
1090 		drv_sta_notify(local, sdata, STA_NOTIFY_SLEEP, &sta->sta);
1091 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
1092 	printk(KERN_DEBUG "%s: STA %pM aid %d enters power save mode\n",
1093 	       sdata->name, sta->sta.addr, sta->sta.aid);
1094 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
1095 }
1096 
1097 static void ap_sta_ps_end(struct sta_info *sta)
1098 {
1099 	struct ieee80211_sub_if_data *sdata = sta->sdata;
1100 
1101 	atomic_dec(&sdata->bss->num_sta_ps);
1102 
1103 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
1104 	printk(KERN_DEBUG "%s: STA %pM aid %d exits power save mode\n",
1105 	       sdata->name, sta->sta.addr, sta->sta.aid);
1106 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
1107 
1108 	if (test_sta_flags(sta, WLAN_STA_PS_DRIVER)) {
1109 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
1110 		printk(KERN_DEBUG "%s: STA %pM aid %d driver-ps-blocked\n",
1111 		       sdata->name, sta->sta.addr, sta->sta.aid);
1112 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
1113 		return;
1114 	}
1115 
1116 	ieee80211_sta_ps_deliver_wakeup(sta);
1117 }
1118 
1119 int ieee80211_sta_ps_transition(struct ieee80211_sta *sta, bool start)
1120 {
1121 	struct sta_info *sta_inf = container_of(sta, struct sta_info, sta);
1122 	bool in_ps;
1123 
1124 	WARN_ON(!(sta_inf->local->hw.flags & IEEE80211_HW_AP_LINK_PS));
1125 
1126 	/* Don't let the same PS state be set twice */
1127 	in_ps = test_sta_flags(sta_inf, WLAN_STA_PS_STA);
1128 	if ((start && in_ps) || (!start && !in_ps))
1129 		return -EINVAL;
1130 
1131 	if (start)
1132 		ap_sta_ps_start(sta_inf);
1133 	else
1134 		ap_sta_ps_end(sta_inf);
1135 
1136 	return 0;
1137 }
1138 EXPORT_SYMBOL(ieee80211_sta_ps_transition);
1139 
1140 static ieee80211_rx_result debug_noinline
1141 ieee80211_rx_h_sta_process(struct ieee80211_rx_data *rx)
1142 {
1143 	struct sta_info *sta = rx->sta;
1144 	struct sk_buff *skb = rx->skb;
1145 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
1146 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
1147 
1148 	if (!sta)
1149 		return RX_CONTINUE;
1150 
1151 	/*
1152 	 * Update last_rx only for IBSS packets which are for the current
1153 	 * BSSID to avoid keeping the current IBSS network alive in cases
1154 	 * where other STAs start using different BSSID.
1155 	 */
1156 	if (rx->sdata->vif.type == NL80211_IFTYPE_ADHOC) {
1157 		u8 *bssid = ieee80211_get_bssid(hdr, rx->skb->len,
1158 						NL80211_IFTYPE_ADHOC);
1159 		if (compare_ether_addr(bssid, rx->sdata->u.ibss.bssid) == 0) {
1160 			sta->last_rx = jiffies;
1161 			if (ieee80211_is_data(hdr->frame_control)) {
1162 				sta->last_rx_rate_idx = status->rate_idx;
1163 				sta->last_rx_rate_flag = status->flag;
1164 			}
1165 		}
1166 	} else if (!is_multicast_ether_addr(hdr->addr1)) {
1167 		/*
1168 		 * Mesh beacons will update last_rx when if they are found to
1169 		 * match the current local configuration when processed.
1170 		 */
1171 		sta->last_rx = jiffies;
1172 		if (ieee80211_is_data(hdr->frame_control)) {
1173 			sta->last_rx_rate_idx = status->rate_idx;
1174 			sta->last_rx_rate_flag = status->flag;
1175 		}
1176 	}
1177 
1178 	if (!(status->rx_flags & IEEE80211_RX_RA_MATCH))
1179 		return RX_CONTINUE;
1180 
1181 	if (rx->sdata->vif.type == NL80211_IFTYPE_STATION)
1182 		ieee80211_sta_rx_notify(rx->sdata, hdr);
1183 
1184 	sta->rx_fragments++;
1185 	sta->rx_bytes += rx->skb->len;
1186 	sta->last_signal = status->signal;
1187 	ewma_add(&sta->avg_signal, -status->signal);
1188 
1189 	/*
1190 	 * Change STA power saving mode only at the end of a frame
1191 	 * exchange sequence.
1192 	 */
1193 	if (!(sta->local->hw.flags & IEEE80211_HW_AP_LINK_PS) &&
1194 	    !ieee80211_has_morefrags(hdr->frame_control) &&
1195 	    !(status->rx_flags & IEEE80211_RX_DEFERRED_RELEASE) &&
1196 	    (rx->sdata->vif.type == NL80211_IFTYPE_AP ||
1197 	     rx->sdata->vif.type == NL80211_IFTYPE_AP_VLAN)) {
1198 		if (test_sta_flags(sta, WLAN_STA_PS_STA)) {
1199 			/*
1200 			 * Ignore doze->wake transitions that are
1201 			 * indicated by non-data frames, the standard
1202 			 * is unclear here, but for example going to
1203 			 * PS mode and then scanning would cause a
1204 			 * doze->wake transition for the probe request,
1205 			 * and that is clearly undesirable.
1206 			 */
1207 			if (ieee80211_is_data(hdr->frame_control) &&
1208 			    !ieee80211_has_pm(hdr->frame_control))
1209 				ap_sta_ps_end(sta);
1210 		} else {
1211 			if (ieee80211_has_pm(hdr->frame_control))
1212 				ap_sta_ps_start(sta);
1213 		}
1214 	}
1215 
1216 	/*
1217 	 * Drop (qos-)data::nullfunc frames silently, since they
1218 	 * are used only to control station power saving mode.
1219 	 */
1220 	if (ieee80211_is_nullfunc(hdr->frame_control) ||
1221 	    ieee80211_is_qos_nullfunc(hdr->frame_control)) {
1222 		I802_DEBUG_INC(rx->local->rx_handlers_drop_nullfunc);
1223 
1224 		/*
1225 		 * If we receive a 4-addr nullfunc frame from a STA
1226 		 * that was not moved to a 4-addr STA vlan yet, drop
1227 		 * the frame to the monitor interface, to make sure
1228 		 * that hostapd sees it
1229 		 */
1230 		if (ieee80211_has_a4(hdr->frame_control) &&
1231 		    (rx->sdata->vif.type == NL80211_IFTYPE_AP ||
1232 		     (rx->sdata->vif.type == NL80211_IFTYPE_AP_VLAN &&
1233 		      !rx->sdata->u.vlan.sta)))
1234 			return RX_DROP_MONITOR;
1235 		/*
1236 		 * Update counter and free packet here to avoid
1237 		 * counting this as a dropped packed.
1238 		 */
1239 		sta->rx_packets++;
1240 		dev_kfree_skb(rx->skb);
1241 		return RX_QUEUED;
1242 	}
1243 
1244 	return RX_CONTINUE;
1245 } /* ieee80211_rx_h_sta_process */
1246 
1247 static inline struct ieee80211_fragment_entry *
1248 ieee80211_reassemble_add(struct ieee80211_sub_if_data *sdata,
1249 			 unsigned int frag, unsigned int seq, int rx_queue,
1250 			 struct sk_buff **skb)
1251 {
1252 	struct ieee80211_fragment_entry *entry;
1253 	int idx;
1254 
1255 	idx = sdata->fragment_next;
1256 	entry = &sdata->fragments[sdata->fragment_next++];
1257 	if (sdata->fragment_next >= IEEE80211_FRAGMENT_MAX)
1258 		sdata->fragment_next = 0;
1259 
1260 	if (!skb_queue_empty(&entry->skb_list)) {
1261 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG
1262 		struct ieee80211_hdr *hdr =
1263 			(struct ieee80211_hdr *) entry->skb_list.next->data;
1264 		printk(KERN_DEBUG "%s: RX reassembly removed oldest "
1265 		       "fragment entry (idx=%d age=%lu seq=%d last_frag=%d "
1266 		       "addr1=%pM addr2=%pM\n",
1267 		       sdata->name, idx,
1268 		       jiffies - entry->first_frag_time, entry->seq,
1269 		       entry->last_frag, hdr->addr1, hdr->addr2);
1270 #endif
1271 		__skb_queue_purge(&entry->skb_list);
1272 	}
1273 
1274 	__skb_queue_tail(&entry->skb_list, *skb); /* no need for locking */
1275 	*skb = NULL;
1276 	entry->first_frag_time = jiffies;
1277 	entry->seq = seq;
1278 	entry->rx_queue = rx_queue;
1279 	entry->last_frag = frag;
1280 	entry->ccmp = 0;
1281 	entry->extra_len = 0;
1282 
1283 	return entry;
1284 }
1285 
1286 static inline struct ieee80211_fragment_entry *
1287 ieee80211_reassemble_find(struct ieee80211_sub_if_data *sdata,
1288 			  unsigned int frag, unsigned int seq,
1289 			  int rx_queue, struct ieee80211_hdr *hdr)
1290 {
1291 	struct ieee80211_fragment_entry *entry;
1292 	int i, idx;
1293 
1294 	idx = sdata->fragment_next;
1295 	for (i = 0; i < IEEE80211_FRAGMENT_MAX; i++) {
1296 		struct ieee80211_hdr *f_hdr;
1297 
1298 		idx--;
1299 		if (idx < 0)
1300 			idx = IEEE80211_FRAGMENT_MAX - 1;
1301 
1302 		entry = &sdata->fragments[idx];
1303 		if (skb_queue_empty(&entry->skb_list) || entry->seq != seq ||
1304 		    entry->rx_queue != rx_queue ||
1305 		    entry->last_frag + 1 != frag)
1306 			continue;
1307 
1308 		f_hdr = (struct ieee80211_hdr *)entry->skb_list.next->data;
1309 
1310 		/*
1311 		 * Check ftype and addresses are equal, else check next fragment
1312 		 */
1313 		if (((hdr->frame_control ^ f_hdr->frame_control) &
1314 		     cpu_to_le16(IEEE80211_FCTL_FTYPE)) ||
1315 		    compare_ether_addr(hdr->addr1, f_hdr->addr1) != 0 ||
1316 		    compare_ether_addr(hdr->addr2, f_hdr->addr2) != 0)
1317 			continue;
1318 
1319 		if (time_after(jiffies, entry->first_frag_time + 2 * HZ)) {
1320 			__skb_queue_purge(&entry->skb_list);
1321 			continue;
1322 		}
1323 		return entry;
1324 	}
1325 
1326 	return NULL;
1327 }
1328 
1329 static ieee80211_rx_result debug_noinline
1330 ieee80211_rx_h_defragment(struct ieee80211_rx_data *rx)
1331 {
1332 	struct ieee80211_hdr *hdr;
1333 	u16 sc;
1334 	__le16 fc;
1335 	unsigned int frag, seq;
1336 	struct ieee80211_fragment_entry *entry;
1337 	struct sk_buff *skb;
1338 	struct ieee80211_rx_status *status;
1339 
1340 	hdr = (struct ieee80211_hdr *)rx->skb->data;
1341 	fc = hdr->frame_control;
1342 	sc = le16_to_cpu(hdr->seq_ctrl);
1343 	frag = sc & IEEE80211_SCTL_FRAG;
1344 
1345 	if (likely((!ieee80211_has_morefrags(fc) && frag == 0) ||
1346 		   (rx->skb)->len < 24 ||
1347 		   is_multicast_ether_addr(hdr->addr1))) {
1348 		/* not fragmented */
1349 		goto out;
1350 	}
1351 	I802_DEBUG_INC(rx->local->rx_handlers_fragments);
1352 
1353 	if (skb_linearize(rx->skb))
1354 		return RX_DROP_UNUSABLE;
1355 
1356 	/*
1357 	 *  skb_linearize() might change the skb->data and
1358 	 *  previously cached variables (in this case, hdr) need to
1359 	 *  be refreshed with the new data.
1360 	 */
1361 	hdr = (struct ieee80211_hdr *)rx->skb->data;
1362 	seq = (sc & IEEE80211_SCTL_SEQ) >> 4;
1363 
1364 	if (frag == 0) {
1365 		/* This is the first fragment of a new frame. */
1366 		entry = ieee80211_reassemble_add(rx->sdata, frag, seq,
1367 						 rx->queue, &(rx->skb));
1368 		if (rx->key && rx->key->conf.cipher == WLAN_CIPHER_SUITE_CCMP &&
1369 		    ieee80211_has_protected(fc)) {
1370 			int queue = ieee80211_is_mgmt(fc) ?
1371 				NUM_RX_DATA_QUEUES : rx->queue;
1372 			/* Store CCMP PN so that we can verify that the next
1373 			 * fragment has a sequential PN value. */
1374 			entry->ccmp = 1;
1375 			memcpy(entry->last_pn,
1376 			       rx->key->u.ccmp.rx_pn[queue],
1377 			       CCMP_PN_LEN);
1378 		}
1379 		return RX_QUEUED;
1380 	}
1381 
1382 	/* This is a fragment for a frame that should already be pending in
1383 	 * fragment cache. Add this fragment to the end of the pending entry.
1384 	 */
1385 	entry = ieee80211_reassemble_find(rx->sdata, frag, seq, rx->queue, hdr);
1386 	if (!entry) {
1387 		I802_DEBUG_INC(rx->local->rx_handlers_drop_defrag);
1388 		return RX_DROP_MONITOR;
1389 	}
1390 
1391 	/* Verify that MPDUs within one MSDU have sequential PN values.
1392 	 * (IEEE 802.11i, 8.3.3.4.5) */
1393 	if (entry->ccmp) {
1394 		int i;
1395 		u8 pn[CCMP_PN_LEN], *rpn;
1396 		int queue;
1397 		if (!rx->key || rx->key->conf.cipher != WLAN_CIPHER_SUITE_CCMP)
1398 			return RX_DROP_UNUSABLE;
1399 		memcpy(pn, entry->last_pn, CCMP_PN_LEN);
1400 		for (i = CCMP_PN_LEN - 1; i >= 0; i--) {
1401 			pn[i]++;
1402 			if (pn[i])
1403 				break;
1404 		}
1405 		queue = ieee80211_is_mgmt(fc) ?
1406 			NUM_RX_DATA_QUEUES : rx->queue;
1407 		rpn = rx->key->u.ccmp.rx_pn[queue];
1408 		if (memcmp(pn, rpn, CCMP_PN_LEN))
1409 			return RX_DROP_UNUSABLE;
1410 		memcpy(entry->last_pn, pn, CCMP_PN_LEN);
1411 	}
1412 
1413 	skb_pull(rx->skb, ieee80211_hdrlen(fc));
1414 	__skb_queue_tail(&entry->skb_list, rx->skb);
1415 	entry->last_frag = frag;
1416 	entry->extra_len += rx->skb->len;
1417 	if (ieee80211_has_morefrags(fc)) {
1418 		rx->skb = NULL;
1419 		return RX_QUEUED;
1420 	}
1421 
1422 	rx->skb = __skb_dequeue(&entry->skb_list);
1423 	if (skb_tailroom(rx->skb) < entry->extra_len) {
1424 		I802_DEBUG_INC(rx->local->rx_expand_skb_head2);
1425 		if (unlikely(pskb_expand_head(rx->skb, 0, entry->extra_len,
1426 					      GFP_ATOMIC))) {
1427 			I802_DEBUG_INC(rx->local->rx_handlers_drop_defrag);
1428 			__skb_queue_purge(&entry->skb_list);
1429 			return RX_DROP_UNUSABLE;
1430 		}
1431 	}
1432 	while ((skb = __skb_dequeue(&entry->skb_list))) {
1433 		memcpy(skb_put(rx->skb, skb->len), skb->data, skb->len);
1434 		dev_kfree_skb(skb);
1435 	}
1436 
1437 	/* Complete frame has been reassembled - process it now */
1438 	status = IEEE80211_SKB_RXCB(rx->skb);
1439 	status->rx_flags |= IEEE80211_RX_FRAGMENTED;
1440 
1441  out:
1442 	if (rx->sta)
1443 		rx->sta->rx_packets++;
1444 	if (is_multicast_ether_addr(hdr->addr1))
1445 		rx->local->dot11MulticastReceivedFrameCount++;
1446 	else
1447 		ieee80211_led_rx(rx->local);
1448 	return RX_CONTINUE;
1449 }
1450 
1451 static ieee80211_rx_result debug_noinline
1452 ieee80211_rx_h_ps_poll(struct ieee80211_rx_data *rx)
1453 {
1454 	struct ieee80211_sub_if_data *sdata = rx->sdata;
1455 	__le16 fc = ((struct ieee80211_hdr *)rx->skb->data)->frame_control;
1456 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
1457 
1458 	if (likely(!rx->sta || !ieee80211_is_pspoll(fc) ||
1459 		   !(status->rx_flags & IEEE80211_RX_RA_MATCH)))
1460 		return RX_CONTINUE;
1461 
1462 	if ((sdata->vif.type != NL80211_IFTYPE_AP) &&
1463 	    (sdata->vif.type != NL80211_IFTYPE_AP_VLAN))
1464 		return RX_DROP_UNUSABLE;
1465 
1466 	if (!test_sta_flags(rx->sta, WLAN_STA_PS_DRIVER))
1467 		ieee80211_sta_ps_deliver_poll_response(rx->sta);
1468 	else
1469 		set_sta_flags(rx->sta, WLAN_STA_PSPOLL);
1470 
1471 	/* Free PS Poll skb here instead of returning RX_DROP that would
1472 	 * count as an dropped frame. */
1473 	dev_kfree_skb(rx->skb);
1474 
1475 	return RX_QUEUED;
1476 }
1477 
1478 static ieee80211_rx_result debug_noinline
1479 ieee80211_rx_h_remove_qos_control(struct ieee80211_rx_data *rx)
1480 {
1481 	u8 *data = rx->skb->data;
1482 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)data;
1483 
1484 	if (!ieee80211_is_data_qos(hdr->frame_control))
1485 		return RX_CONTINUE;
1486 
1487 	/* remove the qos control field, update frame type and meta-data */
1488 	memmove(data + IEEE80211_QOS_CTL_LEN, data,
1489 		ieee80211_hdrlen(hdr->frame_control) - IEEE80211_QOS_CTL_LEN);
1490 	hdr = (struct ieee80211_hdr *)skb_pull(rx->skb, IEEE80211_QOS_CTL_LEN);
1491 	/* change frame type to non QOS */
1492 	hdr->frame_control &= ~cpu_to_le16(IEEE80211_STYPE_QOS_DATA);
1493 
1494 	return RX_CONTINUE;
1495 }
1496 
1497 static int
1498 ieee80211_802_1x_port_control(struct ieee80211_rx_data *rx)
1499 {
1500 	if (unlikely(!rx->sta ||
1501 	    !test_sta_flags(rx->sta, WLAN_STA_AUTHORIZED)))
1502 		return -EACCES;
1503 
1504 	return 0;
1505 }
1506 
1507 static int
1508 ieee80211_drop_unencrypted(struct ieee80211_rx_data *rx, __le16 fc)
1509 {
1510 	struct sk_buff *skb = rx->skb;
1511 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
1512 
1513 	/*
1514 	 * Pass through unencrypted frames if the hardware has
1515 	 * decrypted them already.
1516 	 */
1517 	if (status->flag & RX_FLAG_DECRYPTED)
1518 		return 0;
1519 
1520 	/* Drop unencrypted frames if key is set. */
1521 	if (unlikely(!ieee80211_has_protected(fc) &&
1522 		     !ieee80211_is_nullfunc(fc) &&
1523 		     ieee80211_is_data(fc) &&
1524 		     (rx->key || rx->sdata->drop_unencrypted)))
1525 		return -EACCES;
1526 
1527 	return 0;
1528 }
1529 
1530 static int
1531 ieee80211_drop_unencrypted_mgmt(struct ieee80211_rx_data *rx)
1532 {
1533 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
1534 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
1535 	__le16 fc = hdr->frame_control;
1536 
1537 	/*
1538 	 * Pass through unencrypted frames if the hardware has
1539 	 * decrypted them already.
1540 	 */
1541 	if (status->flag & RX_FLAG_DECRYPTED)
1542 		return 0;
1543 
1544 	if (rx->sta && test_sta_flags(rx->sta, WLAN_STA_MFP)) {
1545 		if (unlikely(!ieee80211_has_protected(fc) &&
1546 			     ieee80211_is_unicast_robust_mgmt_frame(rx->skb) &&
1547 			     rx->key)) {
1548 			if (ieee80211_is_deauth(fc))
1549 				cfg80211_send_unprot_deauth(rx->sdata->dev,
1550 							    rx->skb->data,
1551 							    rx->skb->len);
1552 			else if (ieee80211_is_disassoc(fc))
1553 				cfg80211_send_unprot_disassoc(rx->sdata->dev,
1554 							      rx->skb->data,
1555 							      rx->skb->len);
1556 			return -EACCES;
1557 		}
1558 		/* BIP does not use Protected field, so need to check MMIE */
1559 		if (unlikely(ieee80211_is_multicast_robust_mgmt_frame(rx->skb) &&
1560 			     ieee80211_get_mmie_keyidx(rx->skb) < 0)) {
1561 			if (ieee80211_is_deauth(fc))
1562 				cfg80211_send_unprot_deauth(rx->sdata->dev,
1563 							    rx->skb->data,
1564 							    rx->skb->len);
1565 			else if (ieee80211_is_disassoc(fc))
1566 				cfg80211_send_unprot_disassoc(rx->sdata->dev,
1567 							      rx->skb->data,
1568 							      rx->skb->len);
1569 			return -EACCES;
1570 		}
1571 		/*
1572 		 * When using MFP, Action frames are not allowed prior to
1573 		 * having configured keys.
1574 		 */
1575 		if (unlikely(ieee80211_is_action(fc) && !rx->key &&
1576 			     ieee80211_is_robust_mgmt_frame(
1577 				     (struct ieee80211_hdr *) rx->skb->data)))
1578 			return -EACCES;
1579 	}
1580 
1581 	return 0;
1582 }
1583 
1584 static int
1585 __ieee80211_data_to_8023(struct ieee80211_rx_data *rx)
1586 {
1587 	struct ieee80211_sub_if_data *sdata = rx->sdata;
1588 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
1589 	bool check_port_control = false;
1590 	struct ethhdr *ehdr;
1591 	int ret;
1592 
1593 	if (ieee80211_has_a4(hdr->frame_control) &&
1594 	    sdata->vif.type == NL80211_IFTYPE_AP_VLAN && !sdata->u.vlan.sta)
1595 		return -1;
1596 
1597 	if (sdata->vif.type == NL80211_IFTYPE_STATION &&
1598 	    !!sdata->u.mgd.use_4addr != !!ieee80211_has_a4(hdr->frame_control)) {
1599 
1600 		if (!sdata->u.mgd.use_4addr)
1601 			return -1;
1602 		else
1603 			check_port_control = true;
1604 	}
1605 
1606 	if (is_multicast_ether_addr(hdr->addr1) &&
1607 	    sdata->vif.type == NL80211_IFTYPE_AP_VLAN && sdata->u.vlan.sta)
1608 		return -1;
1609 
1610 	ret = ieee80211_data_to_8023(rx->skb, sdata->vif.addr, sdata->vif.type);
1611 	if (ret < 0 || !check_port_control)
1612 		return ret;
1613 
1614 	ehdr = (struct ethhdr *) rx->skb->data;
1615 	if (ehdr->h_proto != rx->sdata->control_port_protocol)
1616 		return -1;
1617 
1618 	return 0;
1619 }
1620 
1621 /*
1622  * requires that rx->skb is a frame with ethernet header
1623  */
1624 static bool ieee80211_frame_allowed(struct ieee80211_rx_data *rx, __le16 fc)
1625 {
1626 	static const u8 pae_group_addr[ETH_ALEN] __aligned(2)
1627 		= { 0x01, 0x80, 0xC2, 0x00, 0x00, 0x03 };
1628 	struct ethhdr *ehdr = (struct ethhdr *) rx->skb->data;
1629 
1630 	/*
1631 	 * Allow EAPOL frames to us/the PAE group address regardless
1632 	 * of whether the frame was encrypted or not.
1633 	 */
1634 	if (ehdr->h_proto == rx->sdata->control_port_protocol &&
1635 	    (compare_ether_addr(ehdr->h_dest, rx->sdata->vif.addr) == 0 ||
1636 	     compare_ether_addr(ehdr->h_dest, pae_group_addr) == 0))
1637 		return true;
1638 
1639 	if (ieee80211_802_1x_port_control(rx) ||
1640 	    ieee80211_drop_unencrypted(rx, fc))
1641 		return false;
1642 
1643 	return true;
1644 }
1645 
1646 /*
1647  * requires that rx->skb is a frame with ethernet header
1648  */
1649 static void
1650 ieee80211_deliver_skb(struct ieee80211_rx_data *rx)
1651 {
1652 	struct ieee80211_sub_if_data *sdata = rx->sdata;
1653 	struct net_device *dev = sdata->dev;
1654 	struct sk_buff *skb, *xmit_skb;
1655 	struct ethhdr *ehdr = (struct ethhdr *) rx->skb->data;
1656 	struct sta_info *dsta;
1657 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
1658 
1659 	skb = rx->skb;
1660 	xmit_skb = NULL;
1661 
1662 	if ((sdata->vif.type == NL80211_IFTYPE_AP ||
1663 	     sdata->vif.type == NL80211_IFTYPE_AP_VLAN) &&
1664 	    !(sdata->flags & IEEE80211_SDATA_DONT_BRIDGE_PACKETS) &&
1665 	    (status->rx_flags & IEEE80211_RX_RA_MATCH) &&
1666 	    (sdata->vif.type != NL80211_IFTYPE_AP_VLAN || !sdata->u.vlan.sta)) {
1667 		if (is_multicast_ether_addr(ehdr->h_dest)) {
1668 			/*
1669 			 * send multicast frames both to higher layers in
1670 			 * local net stack and back to the wireless medium
1671 			 */
1672 			xmit_skb = skb_copy(skb, GFP_ATOMIC);
1673 			if (!xmit_skb && net_ratelimit())
1674 				printk(KERN_DEBUG "%s: failed to clone "
1675 				       "multicast frame\n", dev->name);
1676 		} else {
1677 			dsta = sta_info_get(sdata, skb->data);
1678 			if (dsta) {
1679 				/*
1680 				 * The destination station is associated to
1681 				 * this AP (in this VLAN), so send the frame
1682 				 * directly to it and do not pass it to local
1683 				 * net stack.
1684 				 */
1685 				xmit_skb = skb;
1686 				skb = NULL;
1687 			}
1688 		}
1689 	}
1690 
1691 	if (skb) {
1692 		int align __maybe_unused;
1693 
1694 #ifndef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
1695 		/*
1696 		 * 'align' will only take the values 0 or 2 here
1697 		 * since all frames are required to be aligned
1698 		 * to 2-byte boundaries when being passed to
1699 		 * mac80211. That also explains the __skb_push()
1700 		 * below.
1701 		 */
1702 		align = ((unsigned long)(skb->data + sizeof(struct ethhdr))) & 3;
1703 		if (align) {
1704 			if (WARN_ON(skb_headroom(skb) < 3)) {
1705 				dev_kfree_skb(skb);
1706 				skb = NULL;
1707 			} else {
1708 				u8 *data = skb->data;
1709 				size_t len = skb_headlen(skb);
1710 				skb->data -= align;
1711 				memmove(skb->data, data, len);
1712 				skb_set_tail_pointer(skb, len);
1713 			}
1714 		}
1715 #endif
1716 
1717 		if (skb) {
1718 			/* deliver to local stack */
1719 			skb->protocol = eth_type_trans(skb, dev);
1720 			memset(skb->cb, 0, sizeof(skb->cb));
1721 			netif_receive_skb(skb);
1722 		}
1723 	}
1724 
1725 	if (xmit_skb) {
1726 		/* send to wireless media */
1727 		xmit_skb->protocol = htons(ETH_P_802_3);
1728 		skb_reset_network_header(xmit_skb);
1729 		skb_reset_mac_header(xmit_skb);
1730 		dev_queue_xmit(xmit_skb);
1731 	}
1732 }
1733 
1734 static ieee80211_rx_result debug_noinline
1735 ieee80211_rx_h_amsdu(struct ieee80211_rx_data *rx)
1736 {
1737 	struct net_device *dev = rx->sdata->dev;
1738 	struct sk_buff *skb = rx->skb;
1739 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
1740 	__le16 fc = hdr->frame_control;
1741 	struct sk_buff_head frame_list;
1742 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
1743 
1744 	if (unlikely(!ieee80211_is_data(fc)))
1745 		return RX_CONTINUE;
1746 
1747 	if (unlikely(!ieee80211_is_data_present(fc)))
1748 		return RX_DROP_MONITOR;
1749 
1750 	if (!(status->rx_flags & IEEE80211_RX_AMSDU))
1751 		return RX_CONTINUE;
1752 
1753 	if (ieee80211_has_a4(hdr->frame_control) &&
1754 	    rx->sdata->vif.type == NL80211_IFTYPE_AP_VLAN &&
1755 	    !rx->sdata->u.vlan.sta)
1756 		return RX_DROP_UNUSABLE;
1757 
1758 	if (is_multicast_ether_addr(hdr->addr1) &&
1759 	    ((rx->sdata->vif.type == NL80211_IFTYPE_AP_VLAN &&
1760 	      rx->sdata->u.vlan.sta) ||
1761 	     (rx->sdata->vif.type == NL80211_IFTYPE_STATION &&
1762 	      rx->sdata->u.mgd.use_4addr)))
1763 		return RX_DROP_UNUSABLE;
1764 
1765 	skb->dev = dev;
1766 	__skb_queue_head_init(&frame_list);
1767 
1768 	if (skb_linearize(skb))
1769 		return RX_DROP_UNUSABLE;
1770 
1771 	ieee80211_amsdu_to_8023s(skb, &frame_list, dev->dev_addr,
1772 				 rx->sdata->vif.type,
1773 				 rx->local->hw.extra_tx_headroom);
1774 
1775 	while (!skb_queue_empty(&frame_list)) {
1776 		rx->skb = __skb_dequeue(&frame_list);
1777 
1778 		if (!ieee80211_frame_allowed(rx, fc)) {
1779 			dev_kfree_skb(rx->skb);
1780 			continue;
1781 		}
1782 		dev->stats.rx_packets++;
1783 		dev->stats.rx_bytes += rx->skb->len;
1784 
1785 		ieee80211_deliver_skb(rx);
1786 	}
1787 
1788 	return RX_QUEUED;
1789 }
1790 
1791 #ifdef CONFIG_MAC80211_MESH
1792 static ieee80211_rx_result
1793 ieee80211_rx_h_mesh_fwding(struct ieee80211_rx_data *rx)
1794 {
1795 	struct ieee80211_hdr *hdr;
1796 	struct ieee80211s_hdr *mesh_hdr;
1797 	unsigned int hdrlen;
1798 	struct sk_buff *skb = rx->skb, *fwd_skb;
1799 	struct ieee80211_local *local = rx->local;
1800 	struct ieee80211_sub_if_data *sdata = rx->sdata;
1801 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
1802 
1803 	hdr = (struct ieee80211_hdr *) skb->data;
1804 	hdrlen = ieee80211_hdrlen(hdr->frame_control);
1805 	mesh_hdr = (struct ieee80211s_hdr *) (skb->data + hdrlen);
1806 
1807 	if (!ieee80211_is_data(hdr->frame_control))
1808 		return RX_CONTINUE;
1809 
1810 	if (!mesh_hdr->ttl)
1811 		/* illegal frame */
1812 		return RX_DROP_MONITOR;
1813 
1814 	if (mesh_hdr->flags & MESH_FLAGS_AE) {
1815 		struct mesh_path *mppath;
1816 		char *proxied_addr;
1817 		char *mpp_addr;
1818 
1819 		if (is_multicast_ether_addr(hdr->addr1)) {
1820 			mpp_addr = hdr->addr3;
1821 			proxied_addr = mesh_hdr->eaddr1;
1822 		} else {
1823 			mpp_addr = hdr->addr4;
1824 			proxied_addr = mesh_hdr->eaddr2;
1825 		}
1826 
1827 		rcu_read_lock();
1828 		mppath = mpp_path_lookup(proxied_addr, sdata);
1829 		if (!mppath) {
1830 			mpp_path_add(proxied_addr, mpp_addr, sdata);
1831 		} else {
1832 			spin_lock_bh(&mppath->state_lock);
1833 			if (compare_ether_addr(mppath->mpp, mpp_addr) != 0)
1834 				memcpy(mppath->mpp, mpp_addr, ETH_ALEN);
1835 			spin_unlock_bh(&mppath->state_lock);
1836 		}
1837 		rcu_read_unlock();
1838 	}
1839 
1840 	/* Frame has reached destination.  Don't forward */
1841 	if (!is_multicast_ether_addr(hdr->addr1) &&
1842 	    compare_ether_addr(sdata->vif.addr, hdr->addr3) == 0)
1843 		return RX_CONTINUE;
1844 
1845 	mesh_hdr->ttl--;
1846 
1847 	if (status->rx_flags & IEEE80211_RX_RA_MATCH) {
1848 		if (!mesh_hdr->ttl)
1849 			IEEE80211_IFSTA_MESH_CTR_INC(&rx->sdata->u.mesh,
1850 						     dropped_frames_ttl);
1851 		else {
1852 			struct ieee80211_hdr *fwd_hdr;
1853 			struct ieee80211_tx_info *info;
1854 
1855 			fwd_skb = skb_copy(skb, GFP_ATOMIC);
1856 
1857 			if (!fwd_skb && net_ratelimit())
1858 				printk(KERN_DEBUG "%s: failed to clone mesh frame\n",
1859 						   sdata->name);
1860 			if (!fwd_skb)
1861 				goto out;
1862 
1863 			fwd_hdr =  (struct ieee80211_hdr *) fwd_skb->data;
1864 			memcpy(fwd_hdr->addr2, sdata->vif.addr, ETH_ALEN);
1865 			info = IEEE80211_SKB_CB(fwd_skb);
1866 			memset(info, 0, sizeof(*info));
1867 			info->flags |= IEEE80211_TX_INTFL_NEED_TXPROCESSING;
1868 			info->control.vif = &rx->sdata->vif;
1869 			skb_set_queue_mapping(skb,
1870 				ieee80211_select_queue(rx->sdata, fwd_skb));
1871 			ieee80211_set_qos_hdr(local, skb);
1872 			if (is_multicast_ether_addr(fwd_hdr->addr1))
1873 				IEEE80211_IFSTA_MESH_CTR_INC(&sdata->u.mesh,
1874 								fwded_mcast);
1875 			else {
1876 				int err;
1877 				/*
1878 				 * Save TA to addr1 to send TA a path error if a
1879 				 * suitable next hop is not found
1880 				 */
1881 				memcpy(fwd_hdr->addr1, fwd_hdr->addr2,
1882 						ETH_ALEN);
1883 				err = mesh_nexthop_lookup(fwd_skb, sdata);
1884 				/* Failed to immediately resolve next hop:
1885 				 * fwded frame was dropped or will be added
1886 				 * later to the pending skb queue.  */
1887 				if (err)
1888 					return RX_DROP_MONITOR;
1889 
1890 				IEEE80211_IFSTA_MESH_CTR_INC(&sdata->u.mesh,
1891 								fwded_unicast);
1892 			}
1893 			IEEE80211_IFSTA_MESH_CTR_INC(&sdata->u.mesh,
1894 						     fwded_frames);
1895 			ieee80211_add_pending_skb(local, fwd_skb);
1896 		}
1897 	}
1898 
1899  out:
1900 	if (is_multicast_ether_addr(hdr->addr1) ||
1901 	    sdata->dev->flags & IFF_PROMISC)
1902 		return RX_CONTINUE;
1903 	else
1904 		return RX_DROP_MONITOR;
1905 }
1906 #endif
1907 
1908 static ieee80211_rx_result debug_noinline
1909 ieee80211_rx_h_data(struct ieee80211_rx_data *rx)
1910 {
1911 	struct ieee80211_sub_if_data *sdata = rx->sdata;
1912 	struct ieee80211_local *local = rx->local;
1913 	struct net_device *dev = sdata->dev;
1914 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
1915 	__le16 fc = hdr->frame_control;
1916 	int err;
1917 
1918 	if (unlikely(!ieee80211_is_data(hdr->frame_control)))
1919 		return RX_CONTINUE;
1920 
1921 	if (unlikely(!ieee80211_is_data_present(hdr->frame_control)))
1922 		return RX_DROP_MONITOR;
1923 
1924 	/*
1925 	 * Allow the cooked monitor interface of an AP to see 4-addr frames so
1926 	 * that a 4-addr station can be detected and moved into a separate VLAN
1927 	 */
1928 	if (ieee80211_has_a4(hdr->frame_control) &&
1929 	    sdata->vif.type == NL80211_IFTYPE_AP)
1930 		return RX_DROP_MONITOR;
1931 
1932 	err = __ieee80211_data_to_8023(rx);
1933 	if (unlikely(err))
1934 		return RX_DROP_UNUSABLE;
1935 
1936 	if (!ieee80211_frame_allowed(rx, fc))
1937 		return RX_DROP_MONITOR;
1938 
1939 	rx->skb->dev = dev;
1940 
1941 	dev->stats.rx_packets++;
1942 	dev->stats.rx_bytes += rx->skb->len;
1943 
1944 	if (local->ps_sdata && local->hw.conf.dynamic_ps_timeout > 0 &&
1945 	    !is_multicast_ether_addr(
1946 		    ((struct ethhdr *)rx->skb->data)->h_dest) &&
1947 	    (!local->scanning &&
1948 	     !test_bit(SDATA_STATE_OFFCHANNEL, &sdata->state))) {
1949 			mod_timer(&local->dynamic_ps_timer, jiffies +
1950 			 msecs_to_jiffies(local->hw.conf.dynamic_ps_timeout));
1951 	}
1952 
1953 	ieee80211_deliver_skb(rx);
1954 
1955 	return RX_QUEUED;
1956 }
1957 
1958 static ieee80211_rx_result debug_noinline
1959 ieee80211_rx_h_ctrl(struct ieee80211_rx_data *rx)
1960 {
1961 	struct ieee80211_local *local = rx->local;
1962 	struct ieee80211_hw *hw = &local->hw;
1963 	struct sk_buff *skb = rx->skb;
1964 	struct ieee80211_bar *bar = (struct ieee80211_bar *)skb->data;
1965 	struct tid_ampdu_rx *tid_agg_rx;
1966 	u16 start_seq_num;
1967 	u16 tid;
1968 
1969 	if (likely(!ieee80211_is_ctl(bar->frame_control)))
1970 		return RX_CONTINUE;
1971 
1972 	if (ieee80211_is_back_req(bar->frame_control)) {
1973 		struct {
1974 			__le16 control, start_seq_num;
1975 		} __packed bar_data;
1976 
1977 		if (!rx->sta)
1978 			return RX_DROP_MONITOR;
1979 
1980 		if (skb_copy_bits(skb, offsetof(struct ieee80211_bar, control),
1981 				  &bar_data, sizeof(bar_data)))
1982 			return RX_DROP_MONITOR;
1983 
1984 		tid = le16_to_cpu(bar_data.control) >> 12;
1985 
1986 		tid_agg_rx = rcu_dereference(rx->sta->ampdu_mlme.tid_rx[tid]);
1987 		if (!tid_agg_rx)
1988 			return RX_DROP_MONITOR;
1989 
1990 		start_seq_num = le16_to_cpu(bar_data.start_seq_num) >> 4;
1991 
1992 		/* reset session timer */
1993 		if (tid_agg_rx->timeout)
1994 			mod_timer(&tid_agg_rx->session_timer,
1995 				  TU_TO_EXP_TIME(tid_agg_rx->timeout));
1996 
1997 		spin_lock(&tid_agg_rx->reorder_lock);
1998 		/* release stored frames up to start of BAR */
1999 		ieee80211_release_reorder_frames(hw, tid_agg_rx, start_seq_num);
2000 		spin_unlock(&tid_agg_rx->reorder_lock);
2001 
2002 		kfree_skb(skb);
2003 		return RX_QUEUED;
2004 	}
2005 
2006 	/*
2007 	 * After this point, we only want management frames,
2008 	 * so we can drop all remaining control frames to
2009 	 * cooked monitor interfaces.
2010 	 */
2011 	return RX_DROP_MONITOR;
2012 }
2013 
2014 static void ieee80211_process_sa_query_req(struct ieee80211_sub_if_data *sdata,
2015 					   struct ieee80211_mgmt *mgmt,
2016 					   size_t len)
2017 {
2018 	struct ieee80211_local *local = sdata->local;
2019 	struct sk_buff *skb;
2020 	struct ieee80211_mgmt *resp;
2021 
2022 	if (compare_ether_addr(mgmt->da, sdata->vif.addr) != 0) {
2023 		/* Not to own unicast address */
2024 		return;
2025 	}
2026 
2027 	if (compare_ether_addr(mgmt->sa, sdata->u.mgd.bssid) != 0 ||
2028 	    compare_ether_addr(mgmt->bssid, sdata->u.mgd.bssid) != 0) {
2029 		/* Not from the current AP or not associated yet. */
2030 		return;
2031 	}
2032 
2033 	if (len < 24 + 1 + sizeof(resp->u.action.u.sa_query)) {
2034 		/* Too short SA Query request frame */
2035 		return;
2036 	}
2037 
2038 	skb = dev_alloc_skb(sizeof(*resp) + local->hw.extra_tx_headroom);
2039 	if (skb == NULL)
2040 		return;
2041 
2042 	skb_reserve(skb, local->hw.extra_tx_headroom);
2043 	resp = (struct ieee80211_mgmt *) skb_put(skb, 24);
2044 	memset(resp, 0, 24);
2045 	memcpy(resp->da, mgmt->sa, ETH_ALEN);
2046 	memcpy(resp->sa, sdata->vif.addr, ETH_ALEN);
2047 	memcpy(resp->bssid, sdata->u.mgd.bssid, ETH_ALEN);
2048 	resp->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
2049 					  IEEE80211_STYPE_ACTION);
2050 	skb_put(skb, 1 + sizeof(resp->u.action.u.sa_query));
2051 	resp->u.action.category = WLAN_CATEGORY_SA_QUERY;
2052 	resp->u.action.u.sa_query.action = WLAN_ACTION_SA_QUERY_RESPONSE;
2053 	memcpy(resp->u.action.u.sa_query.trans_id,
2054 	       mgmt->u.action.u.sa_query.trans_id,
2055 	       WLAN_SA_QUERY_TR_ID_LEN);
2056 
2057 	ieee80211_tx_skb(sdata, skb);
2058 }
2059 
2060 static ieee80211_rx_result debug_noinline
2061 ieee80211_rx_h_mgmt_check(struct ieee80211_rx_data *rx)
2062 {
2063 	struct ieee80211_mgmt *mgmt = (struct ieee80211_mgmt *) rx->skb->data;
2064 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
2065 
2066 	/*
2067 	 * From here on, look only at management frames.
2068 	 * Data and control frames are already handled,
2069 	 * and unknown (reserved) frames are useless.
2070 	 */
2071 	if (rx->skb->len < 24)
2072 		return RX_DROP_MONITOR;
2073 
2074 	if (!ieee80211_is_mgmt(mgmt->frame_control))
2075 		return RX_DROP_MONITOR;
2076 
2077 	if (!(status->rx_flags & IEEE80211_RX_RA_MATCH))
2078 		return RX_DROP_MONITOR;
2079 
2080 	if (ieee80211_drop_unencrypted_mgmt(rx))
2081 		return RX_DROP_UNUSABLE;
2082 
2083 	return RX_CONTINUE;
2084 }
2085 
2086 static ieee80211_rx_result debug_noinline
2087 ieee80211_rx_h_action(struct ieee80211_rx_data *rx)
2088 {
2089 	struct ieee80211_local *local = rx->local;
2090 	struct ieee80211_sub_if_data *sdata = rx->sdata;
2091 	struct ieee80211_mgmt *mgmt = (struct ieee80211_mgmt *) rx->skb->data;
2092 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
2093 	int len = rx->skb->len;
2094 
2095 	if (!ieee80211_is_action(mgmt->frame_control))
2096 		return RX_CONTINUE;
2097 
2098 	/* drop too small frames */
2099 	if (len < IEEE80211_MIN_ACTION_SIZE)
2100 		return RX_DROP_UNUSABLE;
2101 
2102 	if (!rx->sta && mgmt->u.action.category != WLAN_CATEGORY_PUBLIC)
2103 		return RX_DROP_UNUSABLE;
2104 
2105 	if (!(status->rx_flags & IEEE80211_RX_RA_MATCH))
2106 		return RX_DROP_UNUSABLE;
2107 
2108 	switch (mgmt->u.action.category) {
2109 	case WLAN_CATEGORY_BACK:
2110 		/*
2111 		 * The aggregation code is not prepared to handle
2112 		 * anything but STA/AP due to the BSSID handling;
2113 		 * IBSS could work in the code but isn't supported
2114 		 * by drivers or the standard.
2115 		 */
2116 		if (sdata->vif.type != NL80211_IFTYPE_STATION &&
2117 		    sdata->vif.type != NL80211_IFTYPE_AP_VLAN &&
2118 		    sdata->vif.type != NL80211_IFTYPE_AP)
2119 			break;
2120 
2121 		/* verify action_code is present */
2122 		if (len < IEEE80211_MIN_ACTION_SIZE + 1)
2123 			break;
2124 
2125 		switch (mgmt->u.action.u.addba_req.action_code) {
2126 		case WLAN_ACTION_ADDBA_REQ:
2127 			if (len < (IEEE80211_MIN_ACTION_SIZE +
2128 				   sizeof(mgmt->u.action.u.addba_req)))
2129 				goto invalid;
2130 			break;
2131 		case WLAN_ACTION_ADDBA_RESP:
2132 			if (len < (IEEE80211_MIN_ACTION_SIZE +
2133 				   sizeof(mgmt->u.action.u.addba_resp)))
2134 				goto invalid;
2135 			break;
2136 		case WLAN_ACTION_DELBA:
2137 			if (len < (IEEE80211_MIN_ACTION_SIZE +
2138 				   sizeof(mgmt->u.action.u.delba)))
2139 				goto invalid;
2140 			break;
2141 		default:
2142 			goto invalid;
2143 		}
2144 
2145 		goto queue;
2146 	case WLAN_CATEGORY_SPECTRUM_MGMT:
2147 		if (local->hw.conf.channel->band != IEEE80211_BAND_5GHZ)
2148 			break;
2149 
2150 		if (sdata->vif.type != NL80211_IFTYPE_STATION)
2151 			break;
2152 
2153 		/* verify action_code is present */
2154 		if (len < IEEE80211_MIN_ACTION_SIZE + 1)
2155 			break;
2156 
2157 		switch (mgmt->u.action.u.measurement.action_code) {
2158 		case WLAN_ACTION_SPCT_MSR_REQ:
2159 			if (len < (IEEE80211_MIN_ACTION_SIZE +
2160 				   sizeof(mgmt->u.action.u.measurement)))
2161 				break;
2162 			ieee80211_process_measurement_req(sdata, mgmt, len);
2163 			goto handled;
2164 		case WLAN_ACTION_SPCT_CHL_SWITCH:
2165 			if (len < (IEEE80211_MIN_ACTION_SIZE +
2166 				   sizeof(mgmt->u.action.u.chan_switch)))
2167 				break;
2168 
2169 			if (sdata->vif.type != NL80211_IFTYPE_STATION)
2170 				break;
2171 
2172 			if (memcmp(mgmt->bssid, sdata->u.mgd.bssid, ETH_ALEN))
2173 				break;
2174 
2175 			goto queue;
2176 		}
2177 		break;
2178 	case WLAN_CATEGORY_SA_QUERY:
2179 		if (len < (IEEE80211_MIN_ACTION_SIZE +
2180 			   sizeof(mgmt->u.action.u.sa_query)))
2181 			break;
2182 
2183 		switch (mgmt->u.action.u.sa_query.action) {
2184 		case WLAN_ACTION_SA_QUERY_REQUEST:
2185 			if (sdata->vif.type != NL80211_IFTYPE_STATION)
2186 				break;
2187 			ieee80211_process_sa_query_req(sdata, mgmt, len);
2188 			goto handled;
2189 		}
2190 		break;
2191 	case WLAN_CATEGORY_MESH_PLINK:
2192 		if (!ieee80211_vif_is_mesh(&sdata->vif))
2193 			break;
2194 		goto queue;
2195 	case WLAN_CATEGORY_MESH_PATH_SEL:
2196 		if (!mesh_path_sel_is_hwmp(sdata))
2197 			break;
2198 		goto queue;
2199 	}
2200 
2201 	return RX_CONTINUE;
2202 
2203  invalid:
2204 	status->rx_flags |= IEEE80211_RX_MALFORMED_ACTION_FRM;
2205 	/* will return in the next handlers */
2206 	return RX_CONTINUE;
2207 
2208  handled:
2209 	if (rx->sta)
2210 		rx->sta->rx_packets++;
2211 	dev_kfree_skb(rx->skb);
2212 	return RX_QUEUED;
2213 
2214  queue:
2215 	rx->skb->pkt_type = IEEE80211_SDATA_QUEUE_TYPE_FRAME;
2216 	skb_queue_tail(&sdata->skb_queue, rx->skb);
2217 	ieee80211_queue_work(&local->hw, &sdata->work);
2218 	if (rx->sta)
2219 		rx->sta->rx_packets++;
2220 	return RX_QUEUED;
2221 }
2222 
2223 static ieee80211_rx_result debug_noinline
2224 ieee80211_rx_h_userspace_mgmt(struct ieee80211_rx_data *rx)
2225 {
2226 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
2227 
2228 	/* skip known-bad action frames and return them in the next handler */
2229 	if (status->rx_flags & IEEE80211_RX_MALFORMED_ACTION_FRM)
2230 		return RX_CONTINUE;
2231 
2232 	/*
2233 	 * Getting here means the kernel doesn't know how to handle
2234 	 * it, but maybe userspace does ... include returned frames
2235 	 * so userspace can register for those to know whether ones
2236 	 * it transmitted were processed or returned.
2237 	 */
2238 
2239 	if (cfg80211_rx_mgmt(rx->sdata->dev, status->freq,
2240 			     rx->skb->data, rx->skb->len,
2241 			     GFP_ATOMIC)) {
2242 		if (rx->sta)
2243 			rx->sta->rx_packets++;
2244 		dev_kfree_skb(rx->skb);
2245 		return RX_QUEUED;
2246 	}
2247 
2248 
2249 	return RX_CONTINUE;
2250 }
2251 
2252 static ieee80211_rx_result debug_noinline
2253 ieee80211_rx_h_action_return(struct ieee80211_rx_data *rx)
2254 {
2255 	struct ieee80211_local *local = rx->local;
2256 	struct ieee80211_mgmt *mgmt = (struct ieee80211_mgmt *) rx->skb->data;
2257 	struct sk_buff *nskb;
2258 	struct ieee80211_sub_if_data *sdata = rx->sdata;
2259 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
2260 
2261 	if (!ieee80211_is_action(mgmt->frame_control))
2262 		return RX_CONTINUE;
2263 
2264 	/*
2265 	 * For AP mode, hostapd is responsible for handling any action
2266 	 * frames that we didn't handle, including returning unknown
2267 	 * ones. For all other modes we will return them to the sender,
2268 	 * setting the 0x80 bit in the action category, as required by
2269 	 * 802.11-2007 7.3.1.11.
2270 	 * Newer versions of hostapd shall also use the management frame
2271 	 * registration mechanisms, but older ones still use cooked
2272 	 * monitor interfaces so push all frames there.
2273 	 */
2274 	if (!(status->rx_flags & IEEE80211_RX_MALFORMED_ACTION_FRM) &&
2275 	    (sdata->vif.type == NL80211_IFTYPE_AP ||
2276 	     sdata->vif.type == NL80211_IFTYPE_AP_VLAN))
2277 		return RX_DROP_MONITOR;
2278 
2279 	/* do not return rejected action frames */
2280 	if (mgmt->u.action.category & 0x80)
2281 		return RX_DROP_UNUSABLE;
2282 
2283 	nskb = skb_copy_expand(rx->skb, local->hw.extra_tx_headroom, 0,
2284 			       GFP_ATOMIC);
2285 	if (nskb) {
2286 		struct ieee80211_mgmt *nmgmt = (void *)nskb->data;
2287 
2288 		nmgmt->u.action.category |= 0x80;
2289 		memcpy(nmgmt->da, nmgmt->sa, ETH_ALEN);
2290 		memcpy(nmgmt->sa, rx->sdata->vif.addr, ETH_ALEN);
2291 
2292 		memset(nskb->cb, 0, sizeof(nskb->cb));
2293 
2294 		ieee80211_tx_skb(rx->sdata, nskb);
2295 	}
2296 	dev_kfree_skb(rx->skb);
2297 	return RX_QUEUED;
2298 }
2299 
2300 static ieee80211_rx_result debug_noinline
2301 ieee80211_rx_h_mgmt(struct ieee80211_rx_data *rx)
2302 {
2303 	struct ieee80211_sub_if_data *sdata = rx->sdata;
2304 	ieee80211_rx_result rxs;
2305 	struct ieee80211_mgmt *mgmt = (void *)rx->skb->data;
2306 	__le16 stype;
2307 
2308 	rxs = ieee80211_work_rx_mgmt(rx->sdata, rx->skb);
2309 	if (rxs != RX_CONTINUE)
2310 		return rxs;
2311 
2312 	stype = mgmt->frame_control & cpu_to_le16(IEEE80211_FCTL_STYPE);
2313 
2314 	if (!ieee80211_vif_is_mesh(&sdata->vif) &&
2315 	    sdata->vif.type != NL80211_IFTYPE_ADHOC &&
2316 	    sdata->vif.type != NL80211_IFTYPE_STATION)
2317 		return RX_DROP_MONITOR;
2318 
2319 	switch (stype) {
2320 	case cpu_to_le16(IEEE80211_STYPE_BEACON):
2321 	case cpu_to_le16(IEEE80211_STYPE_PROBE_RESP):
2322 		/* process for all: mesh, mlme, ibss */
2323 		break;
2324 	case cpu_to_le16(IEEE80211_STYPE_DEAUTH):
2325 	case cpu_to_le16(IEEE80211_STYPE_DISASSOC):
2326 		if (is_multicast_ether_addr(mgmt->da) &&
2327 		    !is_broadcast_ether_addr(mgmt->da))
2328 			return RX_DROP_MONITOR;
2329 
2330 		/* process only for station */
2331 		if (sdata->vif.type != NL80211_IFTYPE_STATION)
2332 			return RX_DROP_MONITOR;
2333 		break;
2334 	case cpu_to_le16(IEEE80211_STYPE_PROBE_REQ):
2335 	case cpu_to_le16(IEEE80211_STYPE_AUTH):
2336 		/* process only for ibss */
2337 		if (sdata->vif.type != NL80211_IFTYPE_ADHOC)
2338 			return RX_DROP_MONITOR;
2339 		break;
2340 	default:
2341 		return RX_DROP_MONITOR;
2342 	}
2343 
2344 	/* queue up frame and kick off work to process it */
2345 	rx->skb->pkt_type = IEEE80211_SDATA_QUEUE_TYPE_FRAME;
2346 	skb_queue_tail(&sdata->skb_queue, rx->skb);
2347 	ieee80211_queue_work(&rx->local->hw, &sdata->work);
2348 	if (rx->sta)
2349 		rx->sta->rx_packets++;
2350 
2351 	return RX_QUEUED;
2352 }
2353 
2354 static void ieee80211_rx_michael_mic_report(struct ieee80211_hdr *hdr,
2355 					    struct ieee80211_rx_data *rx)
2356 {
2357 	int keyidx;
2358 	unsigned int hdrlen;
2359 
2360 	hdrlen = ieee80211_hdrlen(hdr->frame_control);
2361 	if (rx->skb->len >= hdrlen + 4)
2362 		keyidx = rx->skb->data[hdrlen + 3] >> 6;
2363 	else
2364 		keyidx = -1;
2365 
2366 	if (!rx->sta) {
2367 		/*
2368 		 * Some hardware seem to generate incorrect Michael MIC
2369 		 * reports; ignore them to avoid triggering countermeasures.
2370 		 */
2371 		return;
2372 	}
2373 
2374 	if (!ieee80211_has_protected(hdr->frame_control))
2375 		return;
2376 
2377 	if (rx->sdata->vif.type == NL80211_IFTYPE_AP && keyidx) {
2378 		/*
2379 		 * APs with pairwise keys should never receive Michael MIC
2380 		 * errors for non-zero keyidx because these are reserved for
2381 		 * group keys and only the AP is sending real multicast
2382 		 * frames in the BSS.
2383 		 */
2384 		return;
2385 	}
2386 
2387 	if (!ieee80211_is_data(hdr->frame_control) &&
2388 	    !ieee80211_is_auth(hdr->frame_control))
2389 		return;
2390 
2391 	mac80211_ev_michael_mic_failure(rx->sdata, keyidx, hdr, NULL,
2392 					GFP_ATOMIC);
2393 }
2394 
2395 /* TODO: use IEEE80211_RX_FRAGMENTED */
2396 static void ieee80211_rx_cooked_monitor(struct ieee80211_rx_data *rx,
2397 					struct ieee80211_rate *rate)
2398 {
2399 	struct ieee80211_sub_if_data *sdata;
2400 	struct ieee80211_local *local = rx->local;
2401 	struct ieee80211_rtap_hdr {
2402 		struct ieee80211_radiotap_header hdr;
2403 		u8 flags;
2404 		u8 rate_or_pad;
2405 		__le16 chan_freq;
2406 		__le16 chan_flags;
2407 	} __packed *rthdr;
2408 	struct sk_buff *skb = rx->skb, *skb2;
2409 	struct net_device *prev_dev = NULL;
2410 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
2411 
2412 	/*
2413 	 * If cooked monitor has been processed already, then
2414 	 * don't do it again. If not, set the flag.
2415 	 */
2416 	if (rx->flags & IEEE80211_RX_CMNTR)
2417 		goto out_free_skb;
2418 	rx->flags |= IEEE80211_RX_CMNTR;
2419 
2420 	if (skb_headroom(skb) < sizeof(*rthdr) &&
2421 	    pskb_expand_head(skb, sizeof(*rthdr), 0, GFP_ATOMIC))
2422 		goto out_free_skb;
2423 
2424 	rthdr = (void *)skb_push(skb, sizeof(*rthdr));
2425 	memset(rthdr, 0, sizeof(*rthdr));
2426 	rthdr->hdr.it_len = cpu_to_le16(sizeof(*rthdr));
2427 	rthdr->hdr.it_present =
2428 		cpu_to_le32((1 << IEEE80211_RADIOTAP_FLAGS) |
2429 			    (1 << IEEE80211_RADIOTAP_CHANNEL));
2430 
2431 	if (rate) {
2432 		rthdr->rate_or_pad = rate->bitrate / 5;
2433 		rthdr->hdr.it_present |=
2434 			cpu_to_le32(1 << IEEE80211_RADIOTAP_RATE);
2435 	}
2436 	rthdr->chan_freq = cpu_to_le16(status->freq);
2437 
2438 	if (status->band == IEEE80211_BAND_5GHZ)
2439 		rthdr->chan_flags = cpu_to_le16(IEEE80211_CHAN_OFDM |
2440 						IEEE80211_CHAN_5GHZ);
2441 	else
2442 		rthdr->chan_flags = cpu_to_le16(IEEE80211_CHAN_DYN |
2443 						IEEE80211_CHAN_2GHZ);
2444 
2445 	skb_set_mac_header(skb, 0);
2446 	skb->ip_summed = CHECKSUM_UNNECESSARY;
2447 	skb->pkt_type = PACKET_OTHERHOST;
2448 	skb->protocol = htons(ETH_P_802_2);
2449 
2450 	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
2451 		if (!ieee80211_sdata_running(sdata))
2452 			continue;
2453 
2454 		if (sdata->vif.type != NL80211_IFTYPE_MONITOR ||
2455 		    !(sdata->u.mntr_flags & MONITOR_FLAG_COOK_FRAMES))
2456 			continue;
2457 
2458 		if (prev_dev) {
2459 			skb2 = skb_clone(skb, GFP_ATOMIC);
2460 			if (skb2) {
2461 				skb2->dev = prev_dev;
2462 				netif_receive_skb(skb2);
2463 			}
2464 		}
2465 
2466 		prev_dev = sdata->dev;
2467 		sdata->dev->stats.rx_packets++;
2468 		sdata->dev->stats.rx_bytes += skb->len;
2469 	}
2470 
2471 	if (prev_dev) {
2472 		skb->dev = prev_dev;
2473 		netif_receive_skb(skb);
2474 		return;
2475 	}
2476 
2477  out_free_skb:
2478 	dev_kfree_skb(skb);
2479 }
2480 
2481 static void ieee80211_rx_handlers_result(struct ieee80211_rx_data *rx,
2482 					 ieee80211_rx_result res)
2483 {
2484 	switch (res) {
2485 	case RX_DROP_MONITOR:
2486 		I802_DEBUG_INC(rx->sdata->local->rx_handlers_drop);
2487 		if (rx->sta)
2488 			rx->sta->rx_dropped++;
2489 		/* fall through */
2490 	case RX_CONTINUE: {
2491 		struct ieee80211_rate *rate = NULL;
2492 		struct ieee80211_supported_band *sband;
2493 		struct ieee80211_rx_status *status;
2494 
2495 		status = IEEE80211_SKB_RXCB((rx->skb));
2496 
2497 		sband = rx->local->hw.wiphy->bands[status->band];
2498 		if (!(status->flag & RX_FLAG_HT))
2499 			rate = &sband->bitrates[status->rate_idx];
2500 
2501 		ieee80211_rx_cooked_monitor(rx, rate);
2502 		break;
2503 		}
2504 	case RX_DROP_UNUSABLE:
2505 		I802_DEBUG_INC(rx->sdata->local->rx_handlers_drop);
2506 		if (rx->sta)
2507 			rx->sta->rx_dropped++;
2508 		dev_kfree_skb(rx->skb);
2509 		break;
2510 	case RX_QUEUED:
2511 		I802_DEBUG_INC(rx->sdata->local->rx_handlers_queued);
2512 		break;
2513 	}
2514 }
2515 
2516 static void ieee80211_rx_handlers(struct ieee80211_rx_data *rx)
2517 {
2518 	ieee80211_rx_result res = RX_DROP_MONITOR;
2519 	struct sk_buff *skb;
2520 
2521 #define CALL_RXH(rxh)			\
2522 	do {				\
2523 		res = rxh(rx);		\
2524 		if (res != RX_CONTINUE)	\
2525 			goto rxh_next;  \
2526 	} while (0);
2527 
2528 	spin_lock(&rx->local->rx_skb_queue.lock);
2529 	if (rx->local->running_rx_handler)
2530 		goto unlock;
2531 
2532 	rx->local->running_rx_handler = true;
2533 
2534 	while ((skb = __skb_dequeue(&rx->local->rx_skb_queue))) {
2535 		spin_unlock(&rx->local->rx_skb_queue.lock);
2536 
2537 		/*
2538 		 * all the other fields are valid across frames
2539 		 * that belong to an aMPDU since they are on the
2540 		 * same TID from the same station
2541 		 */
2542 		rx->skb = skb;
2543 		rx->flags = 0;
2544 
2545 		CALL_RXH(ieee80211_rx_h_decrypt)
2546 		CALL_RXH(ieee80211_rx_h_check_more_data)
2547 		CALL_RXH(ieee80211_rx_h_sta_process)
2548 		CALL_RXH(ieee80211_rx_h_defragment)
2549 		CALL_RXH(ieee80211_rx_h_ps_poll)
2550 		CALL_RXH(ieee80211_rx_h_michael_mic_verify)
2551 		/* must be after MMIC verify so header is counted in MPDU mic */
2552 		CALL_RXH(ieee80211_rx_h_remove_qos_control)
2553 		CALL_RXH(ieee80211_rx_h_amsdu)
2554 #ifdef CONFIG_MAC80211_MESH
2555 		if (ieee80211_vif_is_mesh(&rx->sdata->vif))
2556 			CALL_RXH(ieee80211_rx_h_mesh_fwding);
2557 #endif
2558 		CALL_RXH(ieee80211_rx_h_data)
2559 		CALL_RXH(ieee80211_rx_h_ctrl);
2560 		CALL_RXH(ieee80211_rx_h_mgmt_check)
2561 		CALL_RXH(ieee80211_rx_h_action)
2562 		CALL_RXH(ieee80211_rx_h_userspace_mgmt)
2563 		CALL_RXH(ieee80211_rx_h_action_return)
2564 		CALL_RXH(ieee80211_rx_h_mgmt)
2565 
2566  rxh_next:
2567 		ieee80211_rx_handlers_result(rx, res);
2568 		spin_lock(&rx->local->rx_skb_queue.lock);
2569 #undef CALL_RXH
2570 	}
2571 
2572 	rx->local->running_rx_handler = false;
2573 
2574  unlock:
2575 	spin_unlock(&rx->local->rx_skb_queue.lock);
2576 }
2577 
2578 static void ieee80211_invoke_rx_handlers(struct ieee80211_rx_data *rx)
2579 {
2580 	ieee80211_rx_result res = RX_DROP_MONITOR;
2581 
2582 #define CALL_RXH(rxh)			\
2583 	do {				\
2584 		res = rxh(rx);		\
2585 		if (res != RX_CONTINUE)	\
2586 			goto rxh_next;  \
2587 	} while (0);
2588 
2589 	CALL_RXH(ieee80211_rx_h_passive_scan)
2590 	CALL_RXH(ieee80211_rx_h_check)
2591 
2592 	ieee80211_rx_reorder_ampdu(rx);
2593 
2594 	ieee80211_rx_handlers(rx);
2595 	return;
2596 
2597  rxh_next:
2598 	ieee80211_rx_handlers_result(rx, res);
2599 
2600 #undef CALL_RXH
2601 }
2602 
2603 /*
2604  * This function makes calls into the RX path, therefore
2605  * it has to be invoked under RCU read lock.
2606  */
2607 void ieee80211_release_reorder_timeout(struct sta_info *sta, int tid)
2608 {
2609 	struct ieee80211_rx_data rx = {
2610 		.sta = sta,
2611 		.sdata = sta->sdata,
2612 		.local = sta->local,
2613 		.queue = tid,
2614 	};
2615 	struct tid_ampdu_rx *tid_agg_rx;
2616 
2617 	tid_agg_rx = rcu_dereference(sta->ampdu_mlme.tid_rx[tid]);
2618 	if (!tid_agg_rx)
2619 		return;
2620 
2621 	spin_lock(&tid_agg_rx->reorder_lock);
2622 	ieee80211_sta_reorder_release(&sta->local->hw, tid_agg_rx);
2623 	spin_unlock(&tid_agg_rx->reorder_lock);
2624 
2625 	ieee80211_rx_handlers(&rx);
2626 }
2627 
2628 /* main receive path */
2629 
2630 static int prepare_for_handlers(struct ieee80211_rx_data *rx,
2631 				struct ieee80211_hdr *hdr)
2632 {
2633 	struct ieee80211_sub_if_data *sdata = rx->sdata;
2634 	struct sk_buff *skb = rx->skb;
2635 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
2636 	u8 *bssid = ieee80211_get_bssid(hdr, skb->len, sdata->vif.type);
2637 	int multicast = is_multicast_ether_addr(hdr->addr1);
2638 
2639 	switch (sdata->vif.type) {
2640 	case NL80211_IFTYPE_STATION:
2641 		if (!bssid && !sdata->u.mgd.use_4addr)
2642 			return 0;
2643 		if (!multicast &&
2644 		    compare_ether_addr(sdata->vif.addr, hdr->addr1) != 0) {
2645 			if (!(sdata->dev->flags & IFF_PROMISC) ||
2646 			    sdata->u.mgd.use_4addr)
2647 				return 0;
2648 			status->rx_flags &= ~IEEE80211_RX_RA_MATCH;
2649 		}
2650 		break;
2651 	case NL80211_IFTYPE_ADHOC:
2652 		if (!bssid)
2653 			return 0;
2654 		if (ieee80211_is_beacon(hdr->frame_control)) {
2655 			return 1;
2656 		}
2657 		else if (!ieee80211_bssid_match(bssid, sdata->u.ibss.bssid)) {
2658 			if (!(status->rx_flags & IEEE80211_RX_IN_SCAN))
2659 				return 0;
2660 			status->rx_flags &= ~IEEE80211_RX_RA_MATCH;
2661 		} else if (!multicast &&
2662 			   compare_ether_addr(sdata->vif.addr,
2663 					      hdr->addr1) != 0) {
2664 			if (!(sdata->dev->flags & IFF_PROMISC))
2665 				return 0;
2666 			status->rx_flags &= ~IEEE80211_RX_RA_MATCH;
2667 		} else if (!rx->sta) {
2668 			int rate_idx;
2669 			if (status->flag & RX_FLAG_HT)
2670 				rate_idx = 0; /* TODO: HT rates */
2671 			else
2672 				rate_idx = status->rate_idx;
2673 			rx->sta = ieee80211_ibss_add_sta(sdata, bssid,
2674 					hdr->addr2, BIT(rate_idx), GFP_ATOMIC);
2675 		}
2676 		break;
2677 	case NL80211_IFTYPE_MESH_POINT:
2678 		if (!multicast &&
2679 		    compare_ether_addr(sdata->vif.addr,
2680 				       hdr->addr1) != 0) {
2681 			if (!(sdata->dev->flags & IFF_PROMISC))
2682 				return 0;
2683 
2684 			status->rx_flags &= ~IEEE80211_RX_RA_MATCH;
2685 		}
2686 		break;
2687 	case NL80211_IFTYPE_AP_VLAN:
2688 	case NL80211_IFTYPE_AP:
2689 		if (!bssid) {
2690 			if (compare_ether_addr(sdata->vif.addr,
2691 					       hdr->addr1))
2692 				return 0;
2693 		} else if (!ieee80211_bssid_match(bssid,
2694 					sdata->vif.addr)) {
2695 			if (!(status->rx_flags & IEEE80211_RX_IN_SCAN) &&
2696 			    !ieee80211_is_beacon(hdr->frame_control))
2697 				return 0;
2698 			status->rx_flags &= ~IEEE80211_RX_RA_MATCH;
2699 		}
2700 		break;
2701 	case NL80211_IFTYPE_WDS:
2702 		if (bssid || !ieee80211_is_data(hdr->frame_control))
2703 			return 0;
2704 		if (compare_ether_addr(sdata->u.wds.remote_addr, hdr->addr2))
2705 			return 0;
2706 		break;
2707 	default:
2708 		/* should never get here */
2709 		WARN_ON(1);
2710 		break;
2711 	}
2712 
2713 	return 1;
2714 }
2715 
2716 /*
2717  * This function returns whether or not the SKB
2718  * was destined for RX processing or not, which,
2719  * if consume is true, is equivalent to whether
2720  * or not the skb was consumed.
2721  */
2722 static bool ieee80211_prepare_and_rx_handle(struct ieee80211_rx_data *rx,
2723 					    struct sk_buff *skb, bool consume)
2724 {
2725 	struct ieee80211_local *local = rx->local;
2726 	struct ieee80211_sub_if_data *sdata = rx->sdata;
2727 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
2728 	struct ieee80211_hdr *hdr = (void *)skb->data;
2729 	int prepares;
2730 
2731 	rx->skb = skb;
2732 	status->rx_flags |= IEEE80211_RX_RA_MATCH;
2733 	prepares = prepare_for_handlers(rx, hdr);
2734 
2735 	if (!prepares)
2736 		return false;
2737 
2738 	if (status->flag & RX_FLAG_MMIC_ERROR) {
2739 		if (status->rx_flags & IEEE80211_RX_RA_MATCH)
2740 			ieee80211_rx_michael_mic_report(hdr, rx);
2741 		return false;
2742 	}
2743 
2744 	if (!consume) {
2745 		skb = skb_copy(skb, GFP_ATOMIC);
2746 		if (!skb) {
2747 			if (net_ratelimit())
2748 				wiphy_debug(local->hw.wiphy,
2749 					"failed to copy skb for %s\n",
2750 					sdata->name);
2751 			return true;
2752 		}
2753 
2754 		rx->skb = skb;
2755 	}
2756 
2757 	ieee80211_invoke_rx_handlers(rx);
2758 	return true;
2759 }
2760 
2761 /*
2762  * This is the actual Rx frames handler. as it blongs to Rx path it must
2763  * be called with rcu_read_lock protection.
2764  */
2765 static void __ieee80211_rx_handle_packet(struct ieee80211_hw *hw,
2766 					 struct sk_buff *skb)
2767 {
2768 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
2769 	struct ieee80211_local *local = hw_to_local(hw);
2770 	struct ieee80211_sub_if_data *sdata;
2771 	struct ieee80211_hdr *hdr;
2772 	__le16 fc;
2773 	struct ieee80211_rx_data rx;
2774 	struct ieee80211_sub_if_data *prev;
2775 	struct sta_info *sta, *tmp, *prev_sta;
2776 	int err = 0;
2777 
2778 	fc = ((struct ieee80211_hdr *)skb->data)->frame_control;
2779 	memset(&rx, 0, sizeof(rx));
2780 	rx.skb = skb;
2781 	rx.local = local;
2782 
2783 	if (ieee80211_is_data(fc) || ieee80211_is_mgmt(fc))
2784 		local->dot11ReceivedFragmentCount++;
2785 
2786 	if (unlikely(test_bit(SCAN_HW_SCANNING, &local->scanning) ||
2787 		     test_bit(SCAN_SW_SCANNING, &local->scanning)))
2788 		status->rx_flags |= IEEE80211_RX_IN_SCAN;
2789 
2790 	if (ieee80211_is_mgmt(fc))
2791 		err = skb_linearize(skb);
2792 	else
2793 		err = !pskb_may_pull(skb, ieee80211_hdrlen(fc));
2794 
2795 	if (err) {
2796 		dev_kfree_skb(skb);
2797 		return;
2798 	}
2799 
2800 	hdr = (struct ieee80211_hdr *)skb->data;
2801 	ieee80211_parse_qos(&rx);
2802 	ieee80211_verify_alignment(&rx);
2803 
2804 	if (ieee80211_is_data(fc)) {
2805 		prev_sta = NULL;
2806 
2807 		for_each_sta_info(local, hdr->addr2, sta, tmp) {
2808 			if (!prev_sta) {
2809 				prev_sta = sta;
2810 				continue;
2811 			}
2812 
2813 			rx.sta = prev_sta;
2814 			rx.sdata = prev_sta->sdata;
2815 			ieee80211_prepare_and_rx_handle(&rx, skb, false);
2816 
2817 			prev_sta = sta;
2818 		}
2819 
2820 		if (prev_sta) {
2821 			rx.sta = prev_sta;
2822 			rx.sdata = prev_sta->sdata;
2823 
2824 			if (ieee80211_prepare_and_rx_handle(&rx, skb, true))
2825 				return;
2826 			goto out;
2827 		}
2828 	}
2829 
2830 	prev = NULL;
2831 
2832 	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
2833 		if (!ieee80211_sdata_running(sdata))
2834 			continue;
2835 
2836 		if (sdata->vif.type == NL80211_IFTYPE_MONITOR ||
2837 		    sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
2838 			continue;
2839 
2840 		/*
2841 		 * frame is destined for this interface, but if it's
2842 		 * not also for the previous one we handle that after
2843 		 * the loop to avoid copying the SKB once too much
2844 		 */
2845 
2846 		if (!prev) {
2847 			prev = sdata;
2848 			continue;
2849 		}
2850 
2851 		rx.sta = sta_info_get_bss(prev, hdr->addr2);
2852 		rx.sdata = prev;
2853 		ieee80211_prepare_and_rx_handle(&rx, skb, false);
2854 
2855 		prev = sdata;
2856 	}
2857 
2858 	if (prev) {
2859 		rx.sta = sta_info_get_bss(prev, hdr->addr2);
2860 		rx.sdata = prev;
2861 
2862 		if (ieee80211_prepare_and_rx_handle(&rx, skb, true))
2863 			return;
2864 	}
2865 
2866  out:
2867 	dev_kfree_skb(skb);
2868 }
2869 
2870 /*
2871  * This is the receive path handler. It is called by a low level driver when an
2872  * 802.11 MPDU is received from the hardware.
2873  */
2874 void ieee80211_rx(struct ieee80211_hw *hw, struct sk_buff *skb)
2875 {
2876 	struct ieee80211_local *local = hw_to_local(hw);
2877 	struct ieee80211_rate *rate = NULL;
2878 	struct ieee80211_supported_band *sband;
2879 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
2880 
2881 	WARN_ON_ONCE(softirq_count() == 0);
2882 
2883 	if (WARN_ON(status->band < 0 ||
2884 		    status->band >= IEEE80211_NUM_BANDS))
2885 		goto drop;
2886 
2887 	sband = local->hw.wiphy->bands[status->band];
2888 	if (WARN_ON(!sband))
2889 		goto drop;
2890 
2891 	/*
2892 	 * If we're suspending, it is possible although not too likely
2893 	 * that we'd be receiving frames after having already partially
2894 	 * quiesced the stack. We can't process such frames then since
2895 	 * that might, for example, cause stations to be added or other
2896 	 * driver callbacks be invoked.
2897 	 */
2898 	if (unlikely(local->quiescing || local->suspended))
2899 		goto drop;
2900 
2901 	/*
2902 	 * The same happens when we're not even started,
2903 	 * but that's worth a warning.
2904 	 */
2905 	if (WARN_ON(!local->started))
2906 		goto drop;
2907 
2908 	if (likely(!(status->flag & RX_FLAG_FAILED_PLCP_CRC))) {
2909 		/*
2910 		 * Validate the rate, unless a PLCP error means that
2911 		 * we probably can't have a valid rate here anyway.
2912 		 */
2913 
2914 		if (status->flag & RX_FLAG_HT) {
2915 			/*
2916 			 * rate_idx is MCS index, which can be [0-76]
2917 			 * as documented on:
2918 			 *
2919 			 * http://wireless.kernel.org/en/developers/Documentation/ieee80211/802.11n
2920 			 *
2921 			 * Anything else would be some sort of driver or
2922 			 * hardware error. The driver should catch hardware
2923 			 * errors.
2924 			 */
2925 			if (WARN((status->rate_idx < 0 ||
2926 				 status->rate_idx > 76),
2927 				 "Rate marked as an HT rate but passed "
2928 				 "status->rate_idx is not "
2929 				 "an MCS index [0-76]: %d (0x%02x)\n",
2930 				 status->rate_idx,
2931 				 status->rate_idx))
2932 				goto drop;
2933 		} else {
2934 			if (WARN_ON(status->rate_idx < 0 ||
2935 				    status->rate_idx >= sband->n_bitrates))
2936 				goto drop;
2937 			rate = &sband->bitrates[status->rate_idx];
2938 		}
2939 	}
2940 
2941 	status->rx_flags = 0;
2942 
2943 	/*
2944 	 * key references and virtual interfaces are protected using RCU
2945 	 * and this requires that we are in a read-side RCU section during
2946 	 * receive processing
2947 	 */
2948 	rcu_read_lock();
2949 
2950 	/*
2951 	 * Frames with failed FCS/PLCP checksum are not returned,
2952 	 * all other frames are returned without radiotap header
2953 	 * if it was previously present.
2954 	 * Also, frames with less than 16 bytes are dropped.
2955 	 */
2956 	skb = ieee80211_rx_monitor(local, skb, rate);
2957 	if (!skb) {
2958 		rcu_read_unlock();
2959 		return;
2960 	}
2961 
2962 	ieee80211_tpt_led_trig_rx(local,
2963 			((struct ieee80211_hdr *)skb->data)->frame_control,
2964 			skb->len);
2965 	__ieee80211_rx_handle_packet(hw, skb);
2966 
2967 	rcu_read_unlock();
2968 
2969 	return;
2970  drop:
2971 	kfree_skb(skb);
2972 }
2973 EXPORT_SYMBOL(ieee80211_rx);
2974 
2975 /* This is a version of the rx handler that can be called from hard irq
2976  * context. Post the skb on the queue and schedule the tasklet */
2977 void ieee80211_rx_irqsafe(struct ieee80211_hw *hw, struct sk_buff *skb)
2978 {
2979 	struct ieee80211_local *local = hw_to_local(hw);
2980 
2981 	BUILD_BUG_ON(sizeof(struct ieee80211_rx_status) > sizeof(skb->cb));
2982 
2983 	skb->pkt_type = IEEE80211_RX_MSG;
2984 	skb_queue_tail(&local->skb_queue, skb);
2985 	tasklet_schedule(&local->tasklet);
2986 }
2987 EXPORT_SYMBOL(ieee80211_rx_irqsafe);
2988