xref: /linux/net/mac80211/rx.c (revision a33f32244d8550da8b4a26e277ce07d5c6d158b5)
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 			skb_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_TSFT)
81 		len += 8;
82 	if (local->hw.flags & IEEE80211_HW_SIGNAL_DBM)
83 		len += 1;
84 	if (local->hw.flags & IEEE80211_HW_NOISE_DBM)
85 		len += 1;
86 
87 	if (len & 1) /* padding for RX_FLAGS if necessary */
88 		len++;
89 
90 	return len;
91 }
92 
93 /*
94  * ieee80211_add_rx_radiotap_header - add radiotap header
95  *
96  * add a radiotap header containing all the fields which the hardware provided.
97  */
98 static void
99 ieee80211_add_rx_radiotap_header(struct ieee80211_local *local,
100 				 struct sk_buff *skb,
101 				 struct ieee80211_rate *rate,
102 				 int rtap_len)
103 {
104 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
105 	struct ieee80211_radiotap_header *rthdr;
106 	unsigned char *pos;
107 	u16 rx_flags = 0;
108 
109 	rthdr = (struct ieee80211_radiotap_header *)skb_push(skb, rtap_len);
110 	memset(rthdr, 0, rtap_len);
111 
112 	/* radiotap header, set always present flags */
113 	rthdr->it_present =
114 		cpu_to_le32((1 << IEEE80211_RADIOTAP_FLAGS) |
115 			    (1 << IEEE80211_RADIOTAP_CHANNEL) |
116 			    (1 << IEEE80211_RADIOTAP_ANTENNA) |
117 			    (1 << IEEE80211_RADIOTAP_RX_FLAGS));
118 	rthdr->it_len = cpu_to_le16(rtap_len);
119 
120 	pos = (unsigned char *)(rthdr+1);
121 
122 	/* the order of the following fields is important */
123 
124 	/* IEEE80211_RADIOTAP_TSFT */
125 	if (status->flag & RX_FLAG_TSFT) {
126 		put_unaligned_le64(status->mactime, pos);
127 		rthdr->it_present |=
128 			cpu_to_le32(1 << IEEE80211_RADIOTAP_TSFT);
129 		pos += 8;
130 	}
131 
132 	/* IEEE80211_RADIOTAP_FLAGS */
133 	if (local->hw.flags & IEEE80211_HW_RX_INCLUDES_FCS)
134 		*pos |= IEEE80211_RADIOTAP_F_FCS;
135 	if (status->flag & (RX_FLAG_FAILED_FCS_CRC | RX_FLAG_FAILED_PLCP_CRC))
136 		*pos |= IEEE80211_RADIOTAP_F_BADFCS;
137 	if (status->flag & RX_FLAG_SHORTPRE)
138 		*pos |= IEEE80211_RADIOTAP_F_SHORTPRE;
139 	pos++;
140 
141 	/* IEEE80211_RADIOTAP_RATE */
142 	if (status->flag & RX_FLAG_HT) {
143 		/*
144 		 * TODO: add following information into radiotap header once
145 		 * suitable fields are defined for it:
146 		 * - MCS index (status->rate_idx)
147 		 * - HT40 (status->flag & RX_FLAG_40MHZ)
148 		 * - short-GI (status->flag & RX_FLAG_SHORT_GI)
149 		 */
150 		*pos = 0;
151 	} else {
152 		rthdr->it_present |= cpu_to_le32(1 << IEEE80211_RADIOTAP_RATE);
153 		*pos = rate->bitrate / 5;
154 	}
155 	pos++;
156 
157 	/* IEEE80211_RADIOTAP_CHANNEL */
158 	put_unaligned_le16(status->freq, pos);
159 	pos += 2;
160 	if (status->band == IEEE80211_BAND_5GHZ)
161 		put_unaligned_le16(IEEE80211_CHAN_OFDM | IEEE80211_CHAN_5GHZ,
162 				   pos);
163 	else if (status->flag & RX_FLAG_HT)
164 		put_unaligned_le16(IEEE80211_CHAN_DYN | IEEE80211_CHAN_2GHZ,
165 				   pos);
166 	else if (rate->flags & IEEE80211_RATE_ERP_G)
167 		put_unaligned_le16(IEEE80211_CHAN_OFDM | IEEE80211_CHAN_2GHZ,
168 				   pos);
169 	else
170 		put_unaligned_le16(IEEE80211_CHAN_CCK | IEEE80211_CHAN_2GHZ,
171 				   pos);
172 	pos += 2;
173 
174 	/* IEEE80211_RADIOTAP_DBM_ANTSIGNAL */
175 	if (local->hw.flags & IEEE80211_HW_SIGNAL_DBM) {
176 		*pos = status->signal;
177 		rthdr->it_present |=
178 			cpu_to_le32(1 << IEEE80211_RADIOTAP_DBM_ANTSIGNAL);
179 		pos++;
180 	}
181 
182 	/* IEEE80211_RADIOTAP_DBM_ANTNOISE */
183 	if (local->hw.flags & IEEE80211_HW_NOISE_DBM) {
184 		*pos = status->noise;
185 		rthdr->it_present |=
186 			cpu_to_le32(1 << IEEE80211_RADIOTAP_DBM_ANTNOISE);
187 		pos++;
188 	}
189 
190 	/* IEEE80211_RADIOTAP_LOCK_QUALITY is missing */
191 
192 	/* IEEE80211_RADIOTAP_ANTENNA */
193 	*pos = status->antenna;
194 	pos++;
195 
196 	/* IEEE80211_RADIOTAP_DB_ANTNOISE is not used */
197 
198 	/* IEEE80211_RADIOTAP_RX_FLAGS */
199 	/* ensure 2 byte alignment for the 2 byte field as required */
200 	if ((pos - (u8 *)rthdr) & 1)
201 		pos++;
202 	if (status->flag & RX_FLAG_FAILED_PLCP_CRC)
203 		rx_flags |= IEEE80211_RADIOTAP_F_RX_BADPLCP;
204 	put_unaligned_le16(rx_flags, pos);
205 	pos += 2;
206 }
207 
208 /*
209  * This function copies a received frame to all monitor interfaces and
210  * returns a cleaned-up SKB that no longer includes the FCS nor the
211  * radiotap header the driver might have added.
212  */
213 static struct sk_buff *
214 ieee80211_rx_monitor(struct ieee80211_local *local, struct sk_buff *origskb,
215 		     struct ieee80211_rate *rate)
216 {
217 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(origskb);
218 	struct ieee80211_sub_if_data *sdata;
219 	int needed_headroom = 0;
220 	struct sk_buff *skb, *skb2;
221 	struct net_device *prev_dev = NULL;
222 	int present_fcs_len = 0;
223 
224 	/*
225 	 * First, we may need to make a copy of the skb because
226 	 *  (1) we need to modify it for radiotap (if not present), and
227 	 *  (2) the other RX handlers will modify the skb we got.
228 	 *
229 	 * We don't need to, of course, if we aren't going to return
230 	 * the SKB because it has a bad FCS/PLCP checksum.
231 	 */
232 
233 	/* room for the radiotap header based on driver features */
234 	needed_headroom = ieee80211_rx_radiotap_len(local, status);
235 
236 	if (local->hw.flags & IEEE80211_HW_RX_INCLUDES_FCS)
237 		present_fcs_len = FCS_LEN;
238 
239 	if (!local->monitors) {
240 		if (should_drop_frame(origskb, present_fcs_len)) {
241 			dev_kfree_skb(origskb);
242 			return NULL;
243 		}
244 
245 		return remove_monitor_info(local, origskb);
246 	}
247 
248 	if (should_drop_frame(origskb, present_fcs_len)) {
249 		/* only need to expand headroom if necessary */
250 		skb = origskb;
251 		origskb = NULL;
252 
253 		/*
254 		 * This shouldn't trigger often because most devices have an
255 		 * RX header they pull before we get here, and that should
256 		 * be big enough for our radiotap information. We should
257 		 * probably export the length to drivers so that we can have
258 		 * them allocate enough headroom to start with.
259 		 */
260 		if (skb_headroom(skb) < needed_headroom &&
261 		    pskb_expand_head(skb, needed_headroom, 0, GFP_ATOMIC)) {
262 			dev_kfree_skb(skb);
263 			return NULL;
264 		}
265 	} else {
266 		/*
267 		 * Need to make a copy and possibly remove radiotap header
268 		 * and FCS from the original.
269 		 */
270 		skb = skb_copy_expand(origskb, needed_headroom, 0, GFP_ATOMIC);
271 
272 		origskb = remove_monitor_info(local, origskb);
273 
274 		if (!skb)
275 			return origskb;
276 	}
277 
278 	/* prepend radiotap information */
279 	ieee80211_add_rx_radiotap_header(local, skb, rate, needed_headroom);
280 
281 	skb_reset_mac_header(skb);
282 	skb->ip_summed = CHECKSUM_UNNECESSARY;
283 	skb->pkt_type = PACKET_OTHERHOST;
284 	skb->protocol = htons(ETH_P_802_2);
285 
286 	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
287 		if (sdata->vif.type != NL80211_IFTYPE_MONITOR)
288 			continue;
289 
290 		if (sdata->u.mntr_flags & MONITOR_FLAG_COOK_FRAMES)
291 			continue;
292 
293 		if (!ieee80211_sdata_running(sdata))
294 			continue;
295 
296 		if (prev_dev) {
297 			skb2 = skb_clone(skb, GFP_ATOMIC);
298 			if (skb2) {
299 				skb2->dev = prev_dev;
300 				netif_rx(skb2);
301 			}
302 		}
303 
304 		prev_dev = sdata->dev;
305 		sdata->dev->stats.rx_packets++;
306 		sdata->dev->stats.rx_bytes += skb->len;
307 	}
308 
309 	if (prev_dev) {
310 		skb->dev = prev_dev;
311 		netif_rx(skb);
312 	} else
313 		dev_kfree_skb(skb);
314 
315 	return origskb;
316 }
317 
318 
319 static void ieee80211_parse_qos(struct ieee80211_rx_data *rx)
320 {
321 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
322 	int tid;
323 
324 	/* does the frame have a qos control field? */
325 	if (ieee80211_is_data_qos(hdr->frame_control)) {
326 		u8 *qc = ieee80211_get_qos_ctl(hdr);
327 		/* frame has qos control */
328 		tid = *qc & IEEE80211_QOS_CTL_TID_MASK;
329 		if (*qc & IEEE80211_QOS_CONTROL_A_MSDU_PRESENT)
330 			rx->flags |= IEEE80211_RX_AMSDU;
331 		else
332 			rx->flags &= ~IEEE80211_RX_AMSDU;
333 	} else {
334 		/*
335 		 * IEEE 802.11-2007, 7.1.3.4.1 ("Sequence Number field"):
336 		 *
337 		 *	Sequence numbers for management frames, QoS data
338 		 *	frames with a broadcast/multicast address in the
339 		 *	Address 1 field, and all non-QoS data frames sent
340 		 *	by QoS STAs are assigned using an additional single
341 		 *	modulo-4096 counter, [...]
342 		 *
343 		 * We also use that counter for non-QoS STAs.
344 		 */
345 		tid = NUM_RX_DATA_QUEUES - 1;
346 	}
347 
348 	rx->queue = tid;
349 	/* Set skb->priority to 1d tag if highest order bit of TID is not set.
350 	 * For now, set skb->priority to 0 for other cases. */
351 	rx->skb->priority = (tid > 7) ? 0 : tid;
352 }
353 
354 /**
355  * DOC: Packet alignment
356  *
357  * Drivers always need to pass packets that are aligned to two-byte boundaries
358  * to the stack.
359  *
360  * Additionally, should, if possible, align the payload data in a way that
361  * guarantees that the contained IP header is aligned to a four-byte
362  * boundary. In the case of regular frames, this simply means aligning the
363  * payload to a four-byte boundary (because either the IP header is directly
364  * contained, or IV/RFC1042 headers that have a length divisible by four are
365  * in front of it).  If the payload data is not properly aligned and the
366  * architecture doesn't support efficient unaligned operations, mac80211
367  * will align the data.
368  *
369  * With A-MSDU frames, however, the payload data address must yield two modulo
370  * four because there are 14-byte 802.3 headers within the A-MSDU frames that
371  * push the IP header further back to a multiple of four again. Thankfully, the
372  * specs were sane enough this time around to require padding each A-MSDU
373  * subframe to a length that is a multiple of four.
374  *
375  * Padding like Atheros hardware adds which is inbetween the 802.11 header and
376  * the payload is not supported, the driver is required to move the 802.11
377  * header to be directly in front of the payload in that case.
378  */
379 static void ieee80211_verify_alignment(struct ieee80211_rx_data *rx)
380 {
381 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG
382 	WARN_ONCE((unsigned long)rx->skb->data & 1,
383 		  "unaligned packet at 0x%p\n", rx->skb->data);
384 #endif
385 }
386 
387 
388 /* rx handlers */
389 
390 static ieee80211_rx_result debug_noinline
391 ieee80211_rx_h_passive_scan(struct ieee80211_rx_data *rx)
392 {
393 	struct ieee80211_local *local = rx->local;
394 	struct sk_buff *skb = rx->skb;
395 
396 	if (unlikely(test_bit(SCAN_HW_SCANNING, &local->scanning)))
397 		return ieee80211_scan_rx(rx->sdata, skb);
398 
399 	if (unlikely(test_bit(SCAN_SW_SCANNING, &local->scanning) &&
400 		     (rx->flags & IEEE80211_RX_IN_SCAN))) {
401 		/* drop all the other packets during a software scan anyway */
402 		if (ieee80211_scan_rx(rx->sdata, skb) != RX_QUEUED)
403 			dev_kfree_skb(skb);
404 		return RX_QUEUED;
405 	}
406 
407 	if (unlikely(rx->flags & IEEE80211_RX_IN_SCAN)) {
408 		/* scanning finished during invoking of handlers */
409 		I802_DEBUG_INC(local->rx_handlers_drop_passive_scan);
410 		return RX_DROP_UNUSABLE;
411 	}
412 
413 	return RX_CONTINUE;
414 }
415 
416 
417 static int ieee80211_is_unicast_robust_mgmt_frame(struct sk_buff *skb)
418 {
419 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
420 
421 	if (skb->len < 24 || is_multicast_ether_addr(hdr->addr1))
422 		return 0;
423 
424 	return ieee80211_is_robust_mgmt_frame(hdr);
425 }
426 
427 
428 static int ieee80211_is_multicast_robust_mgmt_frame(struct sk_buff *skb)
429 {
430 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
431 
432 	if (skb->len < 24 || !is_multicast_ether_addr(hdr->addr1))
433 		return 0;
434 
435 	return ieee80211_is_robust_mgmt_frame(hdr);
436 }
437 
438 
439 /* Get the BIP key index from MMIE; return -1 if this is not a BIP frame */
440 static int ieee80211_get_mmie_keyidx(struct sk_buff *skb)
441 {
442 	struct ieee80211_mgmt *hdr = (struct ieee80211_mgmt *) skb->data;
443 	struct ieee80211_mmie *mmie;
444 
445 	if (skb->len < 24 + sizeof(*mmie) ||
446 	    !is_multicast_ether_addr(hdr->da))
447 		return -1;
448 
449 	if (!ieee80211_is_robust_mgmt_frame((struct ieee80211_hdr *) hdr))
450 		return -1; /* not a robust management frame */
451 
452 	mmie = (struct ieee80211_mmie *)
453 		(skb->data + skb->len - sizeof(*mmie));
454 	if (mmie->element_id != WLAN_EID_MMIE ||
455 	    mmie->length != sizeof(*mmie) - 2)
456 		return -1;
457 
458 	return le16_to_cpu(mmie->key_id);
459 }
460 
461 
462 static ieee80211_rx_result
463 ieee80211_rx_mesh_check(struct ieee80211_rx_data *rx)
464 {
465 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
466 	unsigned int hdrlen = ieee80211_hdrlen(hdr->frame_control);
467 	char *dev_addr = rx->sdata->vif.addr;
468 
469 	if (ieee80211_is_data(hdr->frame_control)) {
470 		if (is_multicast_ether_addr(hdr->addr1)) {
471 			if (ieee80211_has_tods(hdr->frame_control) ||
472 				!ieee80211_has_fromds(hdr->frame_control))
473 				return RX_DROP_MONITOR;
474 			if (memcmp(hdr->addr3, dev_addr, ETH_ALEN) == 0)
475 				return RX_DROP_MONITOR;
476 		} else {
477 			if (!ieee80211_has_a4(hdr->frame_control))
478 				return RX_DROP_MONITOR;
479 			if (memcmp(hdr->addr4, dev_addr, ETH_ALEN) == 0)
480 				return RX_DROP_MONITOR;
481 		}
482 	}
483 
484 	/* If there is not an established peer link and this is not a peer link
485 	 * establisment frame, beacon or probe, drop the frame.
486 	 */
487 
488 	if (!rx->sta || sta_plink_state(rx->sta) != PLINK_ESTAB) {
489 		struct ieee80211_mgmt *mgmt;
490 
491 		if (!ieee80211_is_mgmt(hdr->frame_control))
492 			return RX_DROP_MONITOR;
493 
494 		if (ieee80211_is_action(hdr->frame_control)) {
495 			mgmt = (struct ieee80211_mgmt *)hdr;
496 			if (mgmt->u.action.category != MESH_PLINK_CATEGORY)
497 				return RX_DROP_MONITOR;
498 			return RX_CONTINUE;
499 		}
500 
501 		if (ieee80211_is_probe_req(hdr->frame_control) ||
502 		    ieee80211_is_probe_resp(hdr->frame_control) ||
503 		    ieee80211_is_beacon(hdr->frame_control))
504 			return RX_CONTINUE;
505 
506 		return RX_DROP_MONITOR;
507 
508 	}
509 
510 #define msh_h_get(h, l) ((struct ieee80211s_hdr *) ((u8 *)h + l))
511 
512 	if (ieee80211_is_data(hdr->frame_control) &&
513 	    is_multicast_ether_addr(hdr->addr1) &&
514 	    mesh_rmc_check(hdr->addr3, msh_h_get(hdr, hdrlen), rx->sdata))
515 		return RX_DROP_MONITOR;
516 #undef msh_h_get
517 
518 	return RX_CONTINUE;
519 }
520 
521 #define SEQ_MODULO 0x1000
522 #define SEQ_MASK   0xfff
523 
524 static inline int seq_less(u16 sq1, u16 sq2)
525 {
526 	return ((sq1 - sq2) & SEQ_MASK) > (SEQ_MODULO >> 1);
527 }
528 
529 static inline u16 seq_inc(u16 sq)
530 {
531 	return (sq + 1) & SEQ_MASK;
532 }
533 
534 static inline u16 seq_sub(u16 sq1, u16 sq2)
535 {
536 	return (sq1 - sq2) & SEQ_MASK;
537 }
538 
539 
540 static void ieee80211_release_reorder_frame(struct ieee80211_hw *hw,
541 					    struct tid_ampdu_rx *tid_agg_rx,
542 					    int index,
543 					    struct sk_buff_head *frames)
544 {
545 	struct ieee80211_supported_band *sband;
546 	struct ieee80211_rate *rate = NULL;
547 	struct sk_buff *skb = tid_agg_rx->reorder_buf[index];
548 	struct ieee80211_rx_status *status;
549 
550 	if (!skb)
551 		goto no_frame;
552 
553 	status = IEEE80211_SKB_RXCB(skb);
554 
555 	/* release the reordered frames to stack */
556 	sband = hw->wiphy->bands[status->band];
557 	if (!(status->flag & RX_FLAG_HT))
558 		rate = &sband->bitrates[status->rate_idx];
559 	tid_agg_rx->stored_mpdu_num--;
560 	tid_agg_rx->reorder_buf[index] = NULL;
561 	__skb_queue_tail(frames, skb);
562 
563 no_frame:
564 	tid_agg_rx->head_seq_num = seq_inc(tid_agg_rx->head_seq_num);
565 }
566 
567 static void ieee80211_release_reorder_frames(struct ieee80211_hw *hw,
568 					     struct tid_ampdu_rx *tid_agg_rx,
569 					     u16 head_seq_num,
570 					     struct sk_buff_head *frames)
571 {
572 	int index;
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, frames);
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 #define HT_RX_REORDER_BUF_TIMEOUT (HZ / 10)
589 
590 /*
591  * As this function belongs to the RX path it must be under
592  * rcu_read_lock protection. It returns false if the frame
593  * can be processed immediately, true if it was consumed.
594  */
595 static bool ieee80211_sta_manage_reorder_buf(struct ieee80211_hw *hw,
596 					     struct tid_ampdu_rx *tid_agg_rx,
597 					     struct sk_buff *skb,
598 					     struct sk_buff_head *frames)
599 {
600 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
601 	u16 sc = le16_to_cpu(hdr->seq_ctrl);
602 	u16 mpdu_seq_num = (sc & IEEE80211_SCTL_SEQ) >> 4;
603 	u16 head_seq_num, buf_size;
604 	int index;
605 
606 	buf_size = tid_agg_rx->buf_size;
607 	head_seq_num = tid_agg_rx->head_seq_num;
608 
609 	/* frame with out of date sequence number */
610 	if (seq_less(mpdu_seq_num, head_seq_num)) {
611 		dev_kfree_skb(skb);
612 		return true;
613 	}
614 
615 	/*
616 	 * If frame the sequence number exceeds our buffering window
617 	 * size release some previous frames to make room for this one.
618 	 */
619 	if (!seq_less(mpdu_seq_num, head_seq_num + buf_size)) {
620 		head_seq_num = seq_inc(seq_sub(mpdu_seq_num, buf_size));
621 		/* release stored frames up to new head to stack */
622 		ieee80211_release_reorder_frames(hw, tid_agg_rx, head_seq_num,
623 						 frames);
624 	}
625 
626 	/* Now the new frame is always in the range of the reordering buffer */
627 
628 	index = seq_sub(mpdu_seq_num, tid_agg_rx->ssn) % tid_agg_rx->buf_size;
629 
630 	/* check if we already stored this frame */
631 	if (tid_agg_rx->reorder_buf[index]) {
632 		dev_kfree_skb(skb);
633 		return true;
634 	}
635 
636 	/*
637 	 * If the current MPDU is in the right order and nothing else
638 	 * is stored we can process it directly, no need to buffer it.
639 	 */
640 	if (mpdu_seq_num == tid_agg_rx->head_seq_num &&
641 	    tid_agg_rx->stored_mpdu_num == 0) {
642 		tid_agg_rx->head_seq_num = seq_inc(tid_agg_rx->head_seq_num);
643 		return false;
644 	}
645 
646 	/* put the frame in the reordering buffer */
647 	tid_agg_rx->reorder_buf[index] = skb;
648 	tid_agg_rx->reorder_time[index] = jiffies;
649 	tid_agg_rx->stored_mpdu_num++;
650 	/* release the buffer until next missing frame */
651 	index = seq_sub(tid_agg_rx->head_seq_num, tid_agg_rx->ssn) %
652 						tid_agg_rx->buf_size;
653 	if (!tid_agg_rx->reorder_buf[index] &&
654 	    tid_agg_rx->stored_mpdu_num > 1) {
655 		/*
656 		 * No buffers ready to be released, but check whether any
657 		 * frames in the reorder buffer have timed out.
658 		 */
659 		int j;
660 		int skipped = 1;
661 		for (j = (index + 1) % tid_agg_rx->buf_size; j != index;
662 		     j = (j + 1) % tid_agg_rx->buf_size) {
663 			if (!tid_agg_rx->reorder_buf[j]) {
664 				skipped++;
665 				continue;
666 			}
667 			if (!time_after(jiffies, tid_agg_rx->reorder_time[j] +
668 					HT_RX_REORDER_BUF_TIMEOUT))
669 				break;
670 
671 #ifdef CONFIG_MAC80211_HT_DEBUG
672 			if (net_ratelimit())
673 				printk(KERN_DEBUG "%s: release an RX reorder "
674 				       "frame due to timeout on earlier "
675 				       "frames\n",
676 				       wiphy_name(hw->wiphy));
677 #endif
678 			ieee80211_release_reorder_frame(hw, tid_agg_rx,
679 							j, frames);
680 
681 			/*
682 			 * Increment the head seq# also for the skipped slots.
683 			 */
684 			tid_agg_rx->head_seq_num =
685 				(tid_agg_rx->head_seq_num + skipped) & SEQ_MASK;
686 			skipped = 0;
687 		}
688 	} else while (tid_agg_rx->reorder_buf[index]) {
689 		ieee80211_release_reorder_frame(hw, tid_agg_rx, index, frames);
690 		index =	seq_sub(tid_agg_rx->head_seq_num, tid_agg_rx->ssn) %
691 							tid_agg_rx->buf_size;
692 	}
693 
694 	return true;
695 }
696 
697 /*
698  * Reorder MPDUs from A-MPDUs, keeping them on a buffer. Returns
699  * true if the MPDU was buffered, false if it should be processed.
700  */
701 static void ieee80211_rx_reorder_ampdu(struct ieee80211_rx_data *rx,
702 				       struct sk_buff_head *frames)
703 {
704 	struct sk_buff *skb = rx->skb;
705 	struct ieee80211_local *local = rx->local;
706 	struct ieee80211_hw *hw = &local->hw;
707 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
708 	struct sta_info *sta = rx->sta;
709 	struct tid_ampdu_rx *tid_agg_rx;
710 	u16 sc;
711 	int tid;
712 
713 	if (!ieee80211_is_data_qos(hdr->frame_control))
714 		goto dont_reorder;
715 
716 	/*
717 	 * filter the QoS data rx stream according to
718 	 * STA/TID and check if this STA/TID is on aggregation
719 	 */
720 
721 	if (!sta)
722 		goto dont_reorder;
723 
724 	tid = *ieee80211_get_qos_ctl(hdr) & IEEE80211_QOS_CTL_TID_MASK;
725 
726 	if (sta->ampdu_mlme.tid_state_rx[tid] != HT_AGG_STATE_OPERATIONAL)
727 		goto dont_reorder;
728 
729 	tid_agg_rx = sta->ampdu_mlme.tid_rx[tid];
730 
731 	/* qos null data frames are excluded */
732 	if (unlikely(hdr->frame_control & cpu_to_le16(IEEE80211_STYPE_NULLFUNC)))
733 		goto dont_reorder;
734 
735 	/* new, potentially un-ordered, ampdu frame - process it */
736 
737 	/* reset session timer */
738 	if (tid_agg_rx->timeout)
739 		mod_timer(&tid_agg_rx->session_timer,
740 			  TU_TO_EXP_TIME(tid_agg_rx->timeout));
741 
742 	/* if this mpdu is fragmented - terminate rx aggregation session */
743 	sc = le16_to_cpu(hdr->seq_ctrl);
744 	if (sc & IEEE80211_SCTL_FRAG) {
745 		ieee80211_sta_stop_rx_ba_session(sta->sdata, sta->sta.addr,
746 			tid, 0, WLAN_REASON_QSTA_REQUIRE_SETUP);
747 		dev_kfree_skb(skb);
748 		return;
749 	}
750 
751 	if (ieee80211_sta_manage_reorder_buf(hw, tid_agg_rx, skb, frames))
752 		return;
753 
754  dont_reorder:
755 	__skb_queue_tail(frames, skb);
756 }
757 
758 static ieee80211_rx_result debug_noinline
759 ieee80211_rx_h_check(struct ieee80211_rx_data *rx)
760 {
761 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
762 
763 	/* Drop duplicate 802.11 retransmissions (IEEE 802.11 Chap. 9.2.9) */
764 	if (rx->sta && !is_multicast_ether_addr(hdr->addr1)) {
765 		if (unlikely(ieee80211_has_retry(hdr->frame_control) &&
766 			     rx->sta->last_seq_ctrl[rx->queue] ==
767 			     hdr->seq_ctrl)) {
768 			if (rx->flags & IEEE80211_RX_RA_MATCH) {
769 				rx->local->dot11FrameDuplicateCount++;
770 				rx->sta->num_duplicates++;
771 			}
772 			return RX_DROP_MONITOR;
773 		} else
774 			rx->sta->last_seq_ctrl[rx->queue] = hdr->seq_ctrl;
775 	}
776 
777 	if (unlikely(rx->skb->len < 16)) {
778 		I802_DEBUG_INC(rx->local->rx_handlers_drop_short);
779 		return RX_DROP_MONITOR;
780 	}
781 
782 	/* Drop disallowed frame classes based on STA auth/assoc state;
783 	 * IEEE 802.11, Chap 5.5.
784 	 *
785 	 * mac80211 filters only based on association state, i.e. it drops
786 	 * Class 3 frames from not associated stations. hostapd sends
787 	 * deauth/disassoc frames when needed. In addition, hostapd is
788 	 * responsible for filtering on both auth and assoc states.
789 	 */
790 
791 	if (ieee80211_vif_is_mesh(&rx->sdata->vif))
792 		return ieee80211_rx_mesh_check(rx);
793 
794 	if (unlikely((ieee80211_is_data(hdr->frame_control) ||
795 		      ieee80211_is_pspoll(hdr->frame_control)) &&
796 		     rx->sdata->vif.type != NL80211_IFTYPE_ADHOC &&
797 		     (!rx->sta || !test_sta_flags(rx->sta, WLAN_STA_ASSOC)))) {
798 		if ((!ieee80211_has_fromds(hdr->frame_control) &&
799 		     !ieee80211_has_tods(hdr->frame_control) &&
800 		     ieee80211_is_data(hdr->frame_control)) ||
801 		    !(rx->flags & IEEE80211_RX_RA_MATCH)) {
802 			/* Drop IBSS frames and frames for other hosts
803 			 * silently. */
804 			return RX_DROP_MONITOR;
805 		}
806 
807 		return RX_DROP_MONITOR;
808 	}
809 
810 	return RX_CONTINUE;
811 }
812 
813 
814 static ieee80211_rx_result debug_noinline
815 ieee80211_rx_h_decrypt(struct ieee80211_rx_data *rx)
816 {
817 	struct sk_buff *skb = rx->skb;
818 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
819 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
820 	int keyidx;
821 	int hdrlen;
822 	ieee80211_rx_result result = RX_DROP_UNUSABLE;
823 	struct ieee80211_key *stakey = NULL;
824 	int mmie_keyidx = -1;
825 
826 	/*
827 	 * Key selection 101
828 	 *
829 	 * There are four types of keys:
830 	 *  - GTK (group keys)
831 	 *  - IGTK (group keys for management frames)
832 	 *  - PTK (pairwise keys)
833 	 *  - STK (station-to-station pairwise keys)
834 	 *
835 	 * When selecting a key, we have to distinguish between multicast
836 	 * (including broadcast) and unicast frames, the latter can only
837 	 * use PTKs and STKs while the former always use GTKs and IGTKs.
838 	 * Unless, of course, actual WEP keys ("pre-RSNA") are used, then
839 	 * unicast frames can also use key indices like GTKs. Hence, if we
840 	 * don't have a PTK/STK we check the key index for a WEP key.
841 	 *
842 	 * Note that in a regular BSS, multicast frames are sent by the
843 	 * AP only, associated stations unicast the frame to the AP first
844 	 * which then multicasts it on their behalf.
845 	 *
846 	 * There is also a slight problem in IBSS mode: GTKs are negotiated
847 	 * with each station, that is something we don't currently handle.
848 	 * The spec seems to expect that one negotiates the same key with
849 	 * every station but there's no such requirement; VLANs could be
850 	 * possible.
851 	 */
852 
853 	/*
854 	 * No point in finding a key and decrypting if the frame is neither
855 	 * addressed to us nor a multicast frame.
856 	 */
857 	if (!(rx->flags & IEEE80211_RX_RA_MATCH))
858 		return RX_CONTINUE;
859 
860 	/* start without a key */
861 	rx->key = NULL;
862 
863 	if (rx->sta)
864 		stakey = rcu_dereference(rx->sta->key);
865 
866 	if (!ieee80211_has_protected(hdr->frame_control))
867 		mmie_keyidx = ieee80211_get_mmie_keyidx(rx->skb);
868 
869 	if (!is_multicast_ether_addr(hdr->addr1) && stakey) {
870 		rx->key = stakey;
871 		/* Skip decryption if the frame is not protected. */
872 		if (!ieee80211_has_protected(hdr->frame_control))
873 			return RX_CONTINUE;
874 	} else if (mmie_keyidx >= 0) {
875 		/* Broadcast/multicast robust management frame / BIP */
876 		if ((status->flag & RX_FLAG_DECRYPTED) &&
877 		    (status->flag & RX_FLAG_IV_STRIPPED))
878 			return RX_CONTINUE;
879 
880 		if (mmie_keyidx < NUM_DEFAULT_KEYS ||
881 		    mmie_keyidx >= NUM_DEFAULT_KEYS + NUM_DEFAULT_MGMT_KEYS)
882 			return RX_DROP_MONITOR; /* unexpected BIP keyidx */
883 		rx->key = rcu_dereference(rx->sdata->keys[mmie_keyidx]);
884 	} else if (!ieee80211_has_protected(hdr->frame_control)) {
885 		/*
886 		 * The frame was not protected, so skip decryption. However, we
887 		 * need to set rx->key if there is a key that could have been
888 		 * used so that the frame may be dropped if encryption would
889 		 * have been expected.
890 		 */
891 		struct ieee80211_key *key = NULL;
892 		if (ieee80211_is_mgmt(hdr->frame_control) &&
893 		    is_multicast_ether_addr(hdr->addr1) &&
894 		    (key = rcu_dereference(rx->sdata->default_mgmt_key)))
895 			rx->key = key;
896 		else if ((key = rcu_dereference(rx->sdata->default_key)))
897 			rx->key = key;
898 		return RX_CONTINUE;
899 	} else {
900 		/*
901 		 * The device doesn't give us the IV so we won't be
902 		 * able to look up the key. That's ok though, we
903 		 * don't need to decrypt the frame, we just won't
904 		 * be able to keep statistics accurate.
905 		 * Except for key threshold notifications, should
906 		 * we somehow allow the driver to tell us which key
907 		 * the hardware used if this flag is set?
908 		 */
909 		if ((status->flag & RX_FLAG_DECRYPTED) &&
910 		    (status->flag & RX_FLAG_IV_STRIPPED))
911 			return RX_CONTINUE;
912 
913 		hdrlen = ieee80211_hdrlen(hdr->frame_control);
914 
915 		if (rx->skb->len < 8 + hdrlen)
916 			return RX_DROP_UNUSABLE; /* TODO: count this? */
917 
918 		/*
919 		 * no need to call ieee80211_wep_get_keyidx,
920 		 * it verifies a bunch of things we've done already
921 		 */
922 		keyidx = rx->skb->data[hdrlen + 3] >> 6;
923 
924 		rx->key = rcu_dereference(rx->sdata->keys[keyidx]);
925 
926 		/*
927 		 * RSNA-protected unicast frames should always be sent with
928 		 * pairwise or station-to-station keys, but for WEP we allow
929 		 * using a key index as well.
930 		 */
931 		if (rx->key && rx->key->conf.alg != ALG_WEP &&
932 		    !is_multicast_ether_addr(hdr->addr1))
933 			rx->key = NULL;
934 	}
935 
936 	if (rx->key) {
937 		rx->key->tx_rx_count++;
938 		/* TODO: add threshold stuff again */
939 	} else {
940 		return RX_DROP_MONITOR;
941 	}
942 
943 	/* Check for weak IVs if possible */
944 	if (rx->sta && rx->key->conf.alg == ALG_WEP &&
945 	    ieee80211_is_data(hdr->frame_control) &&
946 	    (!(status->flag & RX_FLAG_IV_STRIPPED) ||
947 	     !(status->flag & RX_FLAG_DECRYPTED)) &&
948 	    ieee80211_wep_is_weak_iv(rx->skb, rx->key))
949 		rx->sta->wep_weak_iv_count++;
950 
951 	switch (rx->key->conf.alg) {
952 	case ALG_WEP:
953 		result = ieee80211_crypto_wep_decrypt(rx);
954 		break;
955 	case ALG_TKIP:
956 		result = ieee80211_crypto_tkip_decrypt(rx);
957 		break;
958 	case ALG_CCMP:
959 		result = ieee80211_crypto_ccmp_decrypt(rx);
960 		break;
961 	case ALG_AES_CMAC:
962 		result = ieee80211_crypto_aes_cmac_decrypt(rx);
963 		break;
964 	}
965 
966 	/* either the frame has been decrypted or will be dropped */
967 	status->flag |= RX_FLAG_DECRYPTED;
968 
969 	return result;
970 }
971 
972 static ieee80211_rx_result debug_noinline
973 ieee80211_rx_h_check_more_data(struct ieee80211_rx_data *rx)
974 {
975 	struct ieee80211_local *local;
976 	struct ieee80211_hdr *hdr;
977 	struct sk_buff *skb;
978 
979 	local = rx->local;
980 	skb = rx->skb;
981 	hdr = (struct ieee80211_hdr *) skb->data;
982 
983 	if (!local->pspolling)
984 		return RX_CONTINUE;
985 
986 	if (!ieee80211_has_fromds(hdr->frame_control))
987 		/* this is not from AP */
988 		return RX_CONTINUE;
989 
990 	if (!ieee80211_is_data(hdr->frame_control))
991 		return RX_CONTINUE;
992 
993 	if (!ieee80211_has_moredata(hdr->frame_control)) {
994 		/* AP has no more frames buffered for us */
995 		local->pspolling = false;
996 		return RX_CONTINUE;
997 	}
998 
999 	/* more data bit is set, let's request a new frame from the AP */
1000 	ieee80211_send_pspoll(local, rx->sdata);
1001 
1002 	return RX_CONTINUE;
1003 }
1004 
1005 static void ap_sta_ps_start(struct sta_info *sta)
1006 {
1007 	struct ieee80211_sub_if_data *sdata = sta->sdata;
1008 	struct ieee80211_local *local = sdata->local;
1009 
1010 	atomic_inc(&sdata->bss->num_sta_ps);
1011 	set_sta_flags(sta, WLAN_STA_PS_STA);
1012 	drv_sta_notify(local, sdata, STA_NOTIFY_SLEEP, &sta->sta);
1013 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
1014 	printk(KERN_DEBUG "%s: STA %pM aid %d enters power save mode\n",
1015 	       sdata->name, sta->sta.addr, sta->sta.aid);
1016 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
1017 }
1018 
1019 static void ap_sta_ps_end(struct sta_info *sta)
1020 {
1021 	struct ieee80211_sub_if_data *sdata = sta->sdata;
1022 
1023 	atomic_dec(&sdata->bss->num_sta_ps);
1024 
1025 	clear_sta_flags(sta, WLAN_STA_PS_STA);
1026 
1027 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
1028 	printk(KERN_DEBUG "%s: STA %pM aid %d exits power save mode\n",
1029 	       sdata->name, sta->sta.addr, sta->sta.aid);
1030 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
1031 
1032 	if (test_sta_flags(sta, WLAN_STA_PS_DRIVER)) {
1033 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
1034 		printk(KERN_DEBUG "%s: STA %pM aid %d driver-ps-blocked\n",
1035 		       sdata->name, sta->sta.addr, sta->sta.aid);
1036 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
1037 		return;
1038 	}
1039 
1040 	ieee80211_sta_ps_deliver_wakeup(sta);
1041 }
1042 
1043 static ieee80211_rx_result debug_noinline
1044 ieee80211_rx_h_sta_process(struct ieee80211_rx_data *rx)
1045 {
1046 	struct sta_info *sta = rx->sta;
1047 	struct sk_buff *skb = rx->skb;
1048 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
1049 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
1050 
1051 	if (!sta)
1052 		return RX_CONTINUE;
1053 
1054 	/*
1055 	 * Update last_rx only for IBSS packets which are for the current
1056 	 * BSSID to avoid keeping the current IBSS network alive in cases
1057 	 * where other STAs start using different BSSID.
1058 	 */
1059 	if (rx->sdata->vif.type == NL80211_IFTYPE_ADHOC) {
1060 		u8 *bssid = ieee80211_get_bssid(hdr, rx->skb->len,
1061 						NL80211_IFTYPE_ADHOC);
1062 		if (compare_ether_addr(bssid, rx->sdata->u.ibss.bssid) == 0)
1063 			sta->last_rx = jiffies;
1064 	} else if (!is_multicast_ether_addr(hdr->addr1)) {
1065 		/*
1066 		 * Mesh beacons will update last_rx when if they are found to
1067 		 * match the current local configuration when processed.
1068 		 */
1069 		sta->last_rx = jiffies;
1070 	}
1071 
1072 	if (!(rx->flags & IEEE80211_RX_RA_MATCH))
1073 		return RX_CONTINUE;
1074 
1075 	if (rx->sdata->vif.type == NL80211_IFTYPE_STATION)
1076 		ieee80211_sta_rx_notify(rx->sdata, hdr);
1077 
1078 	sta->rx_fragments++;
1079 	sta->rx_bytes += rx->skb->len;
1080 	sta->last_signal = status->signal;
1081 	sta->last_noise = status->noise;
1082 
1083 	/*
1084 	 * Change STA power saving mode only at the end of a frame
1085 	 * exchange sequence.
1086 	 */
1087 	if (!ieee80211_has_morefrags(hdr->frame_control) &&
1088 	    (rx->sdata->vif.type == NL80211_IFTYPE_AP ||
1089 	     rx->sdata->vif.type == NL80211_IFTYPE_AP_VLAN)) {
1090 		if (test_sta_flags(sta, WLAN_STA_PS_STA)) {
1091 			/*
1092 			 * Ignore doze->wake transitions that are
1093 			 * indicated by non-data frames, the standard
1094 			 * is unclear here, but for example going to
1095 			 * PS mode and then scanning would cause a
1096 			 * doze->wake transition for the probe request,
1097 			 * and that is clearly undesirable.
1098 			 */
1099 			if (ieee80211_is_data(hdr->frame_control) &&
1100 			    !ieee80211_has_pm(hdr->frame_control))
1101 				ap_sta_ps_end(sta);
1102 		} else {
1103 			if (ieee80211_has_pm(hdr->frame_control))
1104 				ap_sta_ps_start(sta);
1105 		}
1106 	}
1107 
1108 	/*
1109 	 * Drop (qos-)data::nullfunc frames silently, since they
1110 	 * are used only to control station power saving mode.
1111 	 */
1112 	if (ieee80211_is_nullfunc(hdr->frame_control) ||
1113 	    ieee80211_is_qos_nullfunc(hdr->frame_control)) {
1114 		I802_DEBUG_INC(rx->local->rx_handlers_drop_nullfunc);
1115 
1116 		/*
1117 		 * If we receive a 4-addr nullfunc frame from a STA
1118 		 * that was not moved to a 4-addr STA vlan yet, drop
1119 		 * the frame to the monitor interface, to make sure
1120 		 * that hostapd sees it
1121 		 */
1122 		if (ieee80211_has_a4(hdr->frame_control) &&
1123 		    (rx->sdata->vif.type == NL80211_IFTYPE_AP ||
1124 		     (rx->sdata->vif.type == NL80211_IFTYPE_AP_VLAN &&
1125 		      !rx->sdata->u.vlan.sta)))
1126 			return RX_DROP_MONITOR;
1127 		/*
1128 		 * Update counter and free packet here to avoid
1129 		 * counting this as a dropped packed.
1130 		 */
1131 		sta->rx_packets++;
1132 		dev_kfree_skb(rx->skb);
1133 		return RX_QUEUED;
1134 	}
1135 
1136 	return RX_CONTINUE;
1137 } /* ieee80211_rx_h_sta_process */
1138 
1139 static inline struct ieee80211_fragment_entry *
1140 ieee80211_reassemble_add(struct ieee80211_sub_if_data *sdata,
1141 			 unsigned int frag, unsigned int seq, int rx_queue,
1142 			 struct sk_buff **skb)
1143 {
1144 	struct ieee80211_fragment_entry *entry;
1145 	int idx;
1146 
1147 	idx = sdata->fragment_next;
1148 	entry = &sdata->fragments[sdata->fragment_next++];
1149 	if (sdata->fragment_next >= IEEE80211_FRAGMENT_MAX)
1150 		sdata->fragment_next = 0;
1151 
1152 	if (!skb_queue_empty(&entry->skb_list)) {
1153 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG
1154 		struct ieee80211_hdr *hdr =
1155 			(struct ieee80211_hdr *) entry->skb_list.next->data;
1156 		printk(KERN_DEBUG "%s: RX reassembly removed oldest "
1157 		       "fragment entry (idx=%d age=%lu seq=%d last_frag=%d "
1158 		       "addr1=%pM addr2=%pM\n",
1159 		       sdata->name, idx,
1160 		       jiffies - entry->first_frag_time, entry->seq,
1161 		       entry->last_frag, hdr->addr1, hdr->addr2);
1162 #endif
1163 		__skb_queue_purge(&entry->skb_list);
1164 	}
1165 
1166 	__skb_queue_tail(&entry->skb_list, *skb); /* no need for locking */
1167 	*skb = NULL;
1168 	entry->first_frag_time = jiffies;
1169 	entry->seq = seq;
1170 	entry->rx_queue = rx_queue;
1171 	entry->last_frag = frag;
1172 	entry->ccmp = 0;
1173 	entry->extra_len = 0;
1174 
1175 	return entry;
1176 }
1177 
1178 static inline struct ieee80211_fragment_entry *
1179 ieee80211_reassemble_find(struct ieee80211_sub_if_data *sdata,
1180 			  unsigned int frag, unsigned int seq,
1181 			  int rx_queue, struct ieee80211_hdr *hdr)
1182 {
1183 	struct ieee80211_fragment_entry *entry;
1184 	int i, idx;
1185 
1186 	idx = sdata->fragment_next;
1187 	for (i = 0; i < IEEE80211_FRAGMENT_MAX; i++) {
1188 		struct ieee80211_hdr *f_hdr;
1189 
1190 		idx--;
1191 		if (idx < 0)
1192 			idx = IEEE80211_FRAGMENT_MAX - 1;
1193 
1194 		entry = &sdata->fragments[idx];
1195 		if (skb_queue_empty(&entry->skb_list) || entry->seq != seq ||
1196 		    entry->rx_queue != rx_queue ||
1197 		    entry->last_frag + 1 != frag)
1198 			continue;
1199 
1200 		f_hdr = (struct ieee80211_hdr *)entry->skb_list.next->data;
1201 
1202 		/*
1203 		 * Check ftype and addresses are equal, else check next fragment
1204 		 */
1205 		if (((hdr->frame_control ^ f_hdr->frame_control) &
1206 		     cpu_to_le16(IEEE80211_FCTL_FTYPE)) ||
1207 		    compare_ether_addr(hdr->addr1, f_hdr->addr1) != 0 ||
1208 		    compare_ether_addr(hdr->addr2, f_hdr->addr2) != 0)
1209 			continue;
1210 
1211 		if (time_after(jiffies, entry->first_frag_time + 2 * HZ)) {
1212 			__skb_queue_purge(&entry->skb_list);
1213 			continue;
1214 		}
1215 		return entry;
1216 	}
1217 
1218 	return NULL;
1219 }
1220 
1221 static ieee80211_rx_result debug_noinline
1222 ieee80211_rx_h_defragment(struct ieee80211_rx_data *rx)
1223 {
1224 	struct ieee80211_hdr *hdr;
1225 	u16 sc;
1226 	__le16 fc;
1227 	unsigned int frag, seq;
1228 	struct ieee80211_fragment_entry *entry;
1229 	struct sk_buff *skb;
1230 
1231 	hdr = (struct ieee80211_hdr *)rx->skb->data;
1232 	fc = hdr->frame_control;
1233 	sc = le16_to_cpu(hdr->seq_ctrl);
1234 	frag = sc & IEEE80211_SCTL_FRAG;
1235 
1236 	if (likely((!ieee80211_has_morefrags(fc) && frag == 0) ||
1237 		   (rx->skb)->len < 24 ||
1238 		   is_multicast_ether_addr(hdr->addr1))) {
1239 		/* not fragmented */
1240 		goto out;
1241 	}
1242 	I802_DEBUG_INC(rx->local->rx_handlers_fragments);
1243 
1244 	seq = (sc & IEEE80211_SCTL_SEQ) >> 4;
1245 
1246 	if (frag == 0) {
1247 		/* This is the first fragment of a new frame. */
1248 		entry = ieee80211_reassemble_add(rx->sdata, frag, seq,
1249 						 rx->queue, &(rx->skb));
1250 		if (rx->key && rx->key->conf.alg == ALG_CCMP &&
1251 		    ieee80211_has_protected(fc)) {
1252 			/* Store CCMP PN so that we can verify that the next
1253 			 * fragment has a sequential PN value. */
1254 			entry->ccmp = 1;
1255 			memcpy(entry->last_pn,
1256 			       rx->key->u.ccmp.rx_pn[rx->queue],
1257 			       CCMP_PN_LEN);
1258 		}
1259 		return RX_QUEUED;
1260 	}
1261 
1262 	/* This is a fragment for a frame that should already be pending in
1263 	 * fragment cache. Add this fragment to the end of the pending entry.
1264 	 */
1265 	entry = ieee80211_reassemble_find(rx->sdata, frag, seq, rx->queue, hdr);
1266 	if (!entry) {
1267 		I802_DEBUG_INC(rx->local->rx_handlers_drop_defrag);
1268 		return RX_DROP_MONITOR;
1269 	}
1270 
1271 	/* Verify that MPDUs within one MSDU have sequential PN values.
1272 	 * (IEEE 802.11i, 8.3.3.4.5) */
1273 	if (entry->ccmp) {
1274 		int i;
1275 		u8 pn[CCMP_PN_LEN], *rpn;
1276 		if (!rx->key || rx->key->conf.alg != ALG_CCMP)
1277 			return RX_DROP_UNUSABLE;
1278 		memcpy(pn, entry->last_pn, CCMP_PN_LEN);
1279 		for (i = CCMP_PN_LEN - 1; i >= 0; i--) {
1280 			pn[i]++;
1281 			if (pn[i])
1282 				break;
1283 		}
1284 		rpn = rx->key->u.ccmp.rx_pn[rx->queue];
1285 		if (memcmp(pn, rpn, CCMP_PN_LEN))
1286 			return RX_DROP_UNUSABLE;
1287 		memcpy(entry->last_pn, pn, CCMP_PN_LEN);
1288 	}
1289 
1290 	skb_pull(rx->skb, ieee80211_hdrlen(fc));
1291 	__skb_queue_tail(&entry->skb_list, rx->skb);
1292 	entry->last_frag = frag;
1293 	entry->extra_len += rx->skb->len;
1294 	if (ieee80211_has_morefrags(fc)) {
1295 		rx->skb = NULL;
1296 		return RX_QUEUED;
1297 	}
1298 
1299 	rx->skb = __skb_dequeue(&entry->skb_list);
1300 	if (skb_tailroom(rx->skb) < entry->extra_len) {
1301 		I802_DEBUG_INC(rx->local->rx_expand_skb_head2);
1302 		if (unlikely(pskb_expand_head(rx->skb, 0, entry->extra_len,
1303 					      GFP_ATOMIC))) {
1304 			I802_DEBUG_INC(rx->local->rx_handlers_drop_defrag);
1305 			__skb_queue_purge(&entry->skb_list);
1306 			return RX_DROP_UNUSABLE;
1307 		}
1308 	}
1309 	while ((skb = __skb_dequeue(&entry->skb_list))) {
1310 		memcpy(skb_put(rx->skb, skb->len), skb->data, skb->len);
1311 		dev_kfree_skb(skb);
1312 	}
1313 
1314 	/* Complete frame has been reassembled - process it now */
1315 	rx->flags |= IEEE80211_RX_FRAGMENTED;
1316 
1317  out:
1318 	if (rx->sta)
1319 		rx->sta->rx_packets++;
1320 	if (is_multicast_ether_addr(hdr->addr1))
1321 		rx->local->dot11MulticastReceivedFrameCount++;
1322 	else
1323 		ieee80211_led_rx(rx->local);
1324 	return RX_CONTINUE;
1325 }
1326 
1327 static ieee80211_rx_result debug_noinline
1328 ieee80211_rx_h_ps_poll(struct ieee80211_rx_data *rx)
1329 {
1330 	struct ieee80211_sub_if_data *sdata = rx->sdata;
1331 	__le16 fc = ((struct ieee80211_hdr *)rx->skb->data)->frame_control;
1332 
1333 	if (likely(!rx->sta || !ieee80211_is_pspoll(fc) ||
1334 		   !(rx->flags & IEEE80211_RX_RA_MATCH)))
1335 		return RX_CONTINUE;
1336 
1337 	if ((sdata->vif.type != NL80211_IFTYPE_AP) &&
1338 	    (sdata->vif.type != NL80211_IFTYPE_AP_VLAN))
1339 		return RX_DROP_UNUSABLE;
1340 
1341 	if (!test_sta_flags(rx->sta, WLAN_STA_PS_DRIVER))
1342 		ieee80211_sta_ps_deliver_poll_response(rx->sta);
1343 	else
1344 		set_sta_flags(rx->sta, WLAN_STA_PSPOLL);
1345 
1346 	/* Free PS Poll skb here instead of returning RX_DROP that would
1347 	 * count as an dropped frame. */
1348 	dev_kfree_skb(rx->skb);
1349 
1350 	return RX_QUEUED;
1351 }
1352 
1353 static ieee80211_rx_result debug_noinline
1354 ieee80211_rx_h_remove_qos_control(struct ieee80211_rx_data *rx)
1355 {
1356 	u8 *data = rx->skb->data;
1357 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)data;
1358 
1359 	if (!ieee80211_is_data_qos(hdr->frame_control))
1360 		return RX_CONTINUE;
1361 
1362 	/* remove the qos control field, update frame type and meta-data */
1363 	memmove(data + IEEE80211_QOS_CTL_LEN, data,
1364 		ieee80211_hdrlen(hdr->frame_control) - IEEE80211_QOS_CTL_LEN);
1365 	hdr = (struct ieee80211_hdr *)skb_pull(rx->skb, IEEE80211_QOS_CTL_LEN);
1366 	/* change frame type to non QOS */
1367 	hdr->frame_control &= ~cpu_to_le16(IEEE80211_STYPE_QOS_DATA);
1368 
1369 	return RX_CONTINUE;
1370 }
1371 
1372 static int
1373 ieee80211_802_1x_port_control(struct ieee80211_rx_data *rx)
1374 {
1375 	if (unlikely(!rx->sta ||
1376 	    !test_sta_flags(rx->sta, WLAN_STA_AUTHORIZED)))
1377 		return -EACCES;
1378 
1379 	return 0;
1380 }
1381 
1382 static int
1383 ieee80211_drop_unencrypted(struct ieee80211_rx_data *rx, __le16 fc)
1384 {
1385 	struct sk_buff *skb = rx->skb;
1386 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
1387 
1388 	/*
1389 	 * Pass through unencrypted frames if the hardware has
1390 	 * decrypted them already.
1391 	 */
1392 	if (status->flag & RX_FLAG_DECRYPTED)
1393 		return 0;
1394 
1395 	/* Drop unencrypted frames if key is set. */
1396 	if (unlikely(!ieee80211_has_protected(fc) &&
1397 		     !ieee80211_is_nullfunc(fc) &&
1398 		     ieee80211_is_data(fc) &&
1399 		     (rx->key || rx->sdata->drop_unencrypted)))
1400 		return -EACCES;
1401 
1402 	return 0;
1403 }
1404 
1405 static int
1406 ieee80211_drop_unencrypted_mgmt(struct ieee80211_rx_data *rx)
1407 {
1408 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
1409 	__le16 fc = hdr->frame_control;
1410 	int res;
1411 
1412 	res = ieee80211_drop_unencrypted(rx, fc);
1413 	if (unlikely(res))
1414 		return res;
1415 
1416 	if (rx->sta && test_sta_flags(rx->sta, WLAN_STA_MFP)) {
1417 		if (unlikely(ieee80211_is_unicast_robust_mgmt_frame(rx->skb) &&
1418 			     rx->key))
1419 			return -EACCES;
1420 		/* BIP does not use Protected field, so need to check MMIE */
1421 		if (unlikely(ieee80211_is_multicast_robust_mgmt_frame(rx->skb) &&
1422 			     ieee80211_get_mmie_keyidx(rx->skb) < 0 &&
1423 			     rx->key))
1424 			return -EACCES;
1425 		/*
1426 		 * When using MFP, Action frames are not allowed prior to
1427 		 * having configured keys.
1428 		 */
1429 		if (unlikely(ieee80211_is_action(fc) && !rx->key &&
1430 			     ieee80211_is_robust_mgmt_frame(
1431 				     (struct ieee80211_hdr *) rx->skb->data)))
1432 			return -EACCES;
1433 	}
1434 
1435 	return 0;
1436 }
1437 
1438 static int
1439 __ieee80211_data_to_8023(struct ieee80211_rx_data *rx)
1440 {
1441 	struct ieee80211_sub_if_data *sdata = rx->sdata;
1442 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
1443 
1444 	if (ieee80211_has_a4(hdr->frame_control) &&
1445 	    sdata->vif.type == NL80211_IFTYPE_AP_VLAN && !sdata->u.vlan.sta)
1446 		return -1;
1447 
1448 	if (is_multicast_ether_addr(hdr->addr1) &&
1449 	    ((sdata->vif.type == NL80211_IFTYPE_AP_VLAN && sdata->u.vlan.sta) ||
1450 	     (sdata->vif.type == NL80211_IFTYPE_STATION && sdata->u.mgd.use_4addr)))
1451 		return -1;
1452 
1453 	return ieee80211_data_to_8023(rx->skb, sdata->vif.addr, sdata->vif.type);
1454 }
1455 
1456 /*
1457  * requires that rx->skb is a frame with ethernet header
1458  */
1459 static bool ieee80211_frame_allowed(struct ieee80211_rx_data *rx, __le16 fc)
1460 {
1461 	static const u8 pae_group_addr[ETH_ALEN] __aligned(2)
1462 		= { 0x01, 0x80, 0xC2, 0x00, 0x00, 0x03 };
1463 	struct ethhdr *ehdr = (struct ethhdr *) rx->skb->data;
1464 
1465 	/*
1466 	 * Allow EAPOL frames to us/the PAE group address regardless
1467 	 * of whether the frame was encrypted or not.
1468 	 */
1469 	if (ehdr->h_proto == htons(ETH_P_PAE) &&
1470 	    (compare_ether_addr(ehdr->h_dest, rx->sdata->vif.addr) == 0 ||
1471 	     compare_ether_addr(ehdr->h_dest, pae_group_addr) == 0))
1472 		return true;
1473 
1474 	if (ieee80211_802_1x_port_control(rx) ||
1475 	    ieee80211_drop_unencrypted(rx, fc))
1476 		return false;
1477 
1478 	return true;
1479 }
1480 
1481 /*
1482  * requires that rx->skb is a frame with ethernet header
1483  */
1484 static void
1485 ieee80211_deliver_skb(struct ieee80211_rx_data *rx)
1486 {
1487 	struct ieee80211_sub_if_data *sdata = rx->sdata;
1488 	struct net_device *dev = sdata->dev;
1489 	struct sk_buff *skb, *xmit_skb;
1490 	struct ethhdr *ehdr = (struct ethhdr *) rx->skb->data;
1491 	struct sta_info *dsta;
1492 
1493 	skb = rx->skb;
1494 	xmit_skb = NULL;
1495 
1496 	if ((sdata->vif.type == NL80211_IFTYPE_AP ||
1497 	     sdata->vif.type == NL80211_IFTYPE_AP_VLAN) &&
1498 	    !(sdata->flags & IEEE80211_SDATA_DONT_BRIDGE_PACKETS) &&
1499 	    (rx->flags & IEEE80211_RX_RA_MATCH) &&
1500 	    (sdata->vif.type != NL80211_IFTYPE_AP_VLAN || !sdata->u.vlan.sta)) {
1501 		if (is_multicast_ether_addr(ehdr->h_dest)) {
1502 			/*
1503 			 * send multicast frames both to higher layers in
1504 			 * local net stack and back to the wireless medium
1505 			 */
1506 			xmit_skb = skb_copy(skb, GFP_ATOMIC);
1507 			if (!xmit_skb && net_ratelimit())
1508 				printk(KERN_DEBUG "%s: failed to clone "
1509 				       "multicast frame\n", dev->name);
1510 		} else {
1511 			dsta = sta_info_get(sdata, skb->data);
1512 			if (dsta) {
1513 				/*
1514 				 * The destination station is associated to
1515 				 * this AP (in this VLAN), so send the frame
1516 				 * directly to it and do not pass it to local
1517 				 * net stack.
1518 				 */
1519 				xmit_skb = skb;
1520 				skb = NULL;
1521 			}
1522 		}
1523 	}
1524 
1525 	if (skb) {
1526 		int align __maybe_unused;
1527 
1528 #ifndef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
1529 		/*
1530 		 * 'align' will only take the values 0 or 2 here
1531 		 * since all frames are required to be aligned
1532 		 * to 2-byte boundaries when being passed to
1533 		 * mac80211. That also explains the __skb_push()
1534 		 * below.
1535 		 */
1536 		align = ((unsigned long)(skb->data + sizeof(struct ethhdr))) & 3;
1537 		if (align) {
1538 			if (WARN_ON(skb_headroom(skb) < 3)) {
1539 				dev_kfree_skb(skb);
1540 				skb = NULL;
1541 			} else {
1542 				u8 *data = skb->data;
1543 				size_t len = skb_headlen(skb);
1544 				skb->data -= align;
1545 				memmove(skb->data, data, len);
1546 				skb_set_tail_pointer(skb, len);
1547 			}
1548 		}
1549 #endif
1550 
1551 		if (skb) {
1552 			/* deliver to local stack */
1553 			skb->protocol = eth_type_trans(skb, dev);
1554 			memset(skb->cb, 0, sizeof(skb->cb));
1555 			netif_rx(skb);
1556 		}
1557 	}
1558 
1559 	if (xmit_skb) {
1560 		/* send to wireless media */
1561 		xmit_skb->protocol = htons(ETH_P_802_3);
1562 		skb_reset_network_header(xmit_skb);
1563 		skb_reset_mac_header(xmit_skb);
1564 		dev_queue_xmit(xmit_skb);
1565 	}
1566 }
1567 
1568 static ieee80211_rx_result debug_noinline
1569 ieee80211_rx_h_amsdu(struct ieee80211_rx_data *rx)
1570 {
1571 	struct net_device *dev = rx->sdata->dev;
1572 	struct sk_buff *skb = rx->skb;
1573 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
1574 	__le16 fc = hdr->frame_control;
1575 	struct sk_buff_head frame_list;
1576 
1577 	if (unlikely(!ieee80211_is_data(fc)))
1578 		return RX_CONTINUE;
1579 
1580 	if (unlikely(!ieee80211_is_data_present(fc)))
1581 		return RX_DROP_MONITOR;
1582 
1583 	if (!(rx->flags & IEEE80211_RX_AMSDU))
1584 		return RX_CONTINUE;
1585 
1586 	if (ieee80211_has_a4(hdr->frame_control) &&
1587 	    rx->sdata->vif.type == NL80211_IFTYPE_AP_VLAN &&
1588 	    !rx->sdata->u.vlan.sta)
1589 		return RX_DROP_UNUSABLE;
1590 
1591 	if (is_multicast_ether_addr(hdr->addr1) &&
1592 	    ((rx->sdata->vif.type == NL80211_IFTYPE_AP_VLAN &&
1593 	      rx->sdata->u.vlan.sta) ||
1594 	     (rx->sdata->vif.type == NL80211_IFTYPE_STATION &&
1595 	      rx->sdata->u.mgd.use_4addr)))
1596 		return RX_DROP_UNUSABLE;
1597 
1598 	skb->dev = dev;
1599 	__skb_queue_head_init(&frame_list);
1600 
1601 	ieee80211_amsdu_to_8023s(skb, &frame_list, dev->dev_addr,
1602 				 rx->sdata->vif.type,
1603 				 rx->local->hw.extra_tx_headroom);
1604 
1605 	while (!skb_queue_empty(&frame_list)) {
1606 		rx->skb = __skb_dequeue(&frame_list);
1607 
1608 		if (!ieee80211_frame_allowed(rx, fc)) {
1609 			dev_kfree_skb(rx->skb);
1610 			continue;
1611 		}
1612 		dev->stats.rx_packets++;
1613 		dev->stats.rx_bytes += rx->skb->len;
1614 
1615 		ieee80211_deliver_skb(rx);
1616 	}
1617 
1618 	return RX_QUEUED;
1619 }
1620 
1621 #ifdef CONFIG_MAC80211_MESH
1622 static ieee80211_rx_result
1623 ieee80211_rx_h_mesh_fwding(struct ieee80211_rx_data *rx)
1624 {
1625 	struct ieee80211_hdr *hdr;
1626 	struct ieee80211s_hdr *mesh_hdr;
1627 	unsigned int hdrlen;
1628 	struct sk_buff *skb = rx->skb, *fwd_skb;
1629 	struct ieee80211_local *local = rx->local;
1630 	struct ieee80211_sub_if_data *sdata = rx->sdata;
1631 
1632 	hdr = (struct ieee80211_hdr *) skb->data;
1633 	hdrlen = ieee80211_hdrlen(hdr->frame_control);
1634 	mesh_hdr = (struct ieee80211s_hdr *) (skb->data + hdrlen);
1635 
1636 	if (!ieee80211_is_data(hdr->frame_control))
1637 		return RX_CONTINUE;
1638 
1639 	if (!mesh_hdr->ttl)
1640 		/* illegal frame */
1641 		return RX_DROP_MONITOR;
1642 
1643 	if (mesh_hdr->flags & MESH_FLAGS_AE) {
1644 		struct mesh_path *mppath;
1645 		char *proxied_addr;
1646 		char *mpp_addr;
1647 
1648 		if (is_multicast_ether_addr(hdr->addr1)) {
1649 			mpp_addr = hdr->addr3;
1650 			proxied_addr = mesh_hdr->eaddr1;
1651 		} else {
1652 			mpp_addr = hdr->addr4;
1653 			proxied_addr = mesh_hdr->eaddr2;
1654 		}
1655 
1656 		rcu_read_lock();
1657 		mppath = mpp_path_lookup(proxied_addr, sdata);
1658 		if (!mppath) {
1659 			mpp_path_add(proxied_addr, mpp_addr, sdata);
1660 		} else {
1661 			spin_lock_bh(&mppath->state_lock);
1662 			if (compare_ether_addr(mppath->mpp, mpp_addr) != 0)
1663 				memcpy(mppath->mpp, mpp_addr, ETH_ALEN);
1664 			spin_unlock_bh(&mppath->state_lock);
1665 		}
1666 		rcu_read_unlock();
1667 	}
1668 
1669 	/* Frame has reached destination.  Don't forward */
1670 	if (!is_multicast_ether_addr(hdr->addr1) &&
1671 	    compare_ether_addr(sdata->vif.addr, hdr->addr3) == 0)
1672 		return RX_CONTINUE;
1673 
1674 	mesh_hdr->ttl--;
1675 
1676 	if (rx->flags & IEEE80211_RX_RA_MATCH) {
1677 		if (!mesh_hdr->ttl)
1678 			IEEE80211_IFSTA_MESH_CTR_INC(&rx->sdata->u.mesh,
1679 						     dropped_frames_ttl);
1680 		else {
1681 			struct ieee80211_hdr *fwd_hdr;
1682 			struct ieee80211_tx_info *info;
1683 
1684 			fwd_skb = skb_copy(skb, GFP_ATOMIC);
1685 
1686 			if (!fwd_skb && net_ratelimit())
1687 				printk(KERN_DEBUG "%s: failed to clone mesh frame\n",
1688 						   sdata->name);
1689 
1690 			fwd_hdr =  (struct ieee80211_hdr *) fwd_skb->data;
1691 			memcpy(fwd_hdr->addr2, sdata->vif.addr, ETH_ALEN);
1692 			info = IEEE80211_SKB_CB(fwd_skb);
1693 			memset(info, 0, sizeof(*info));
1694 			info->flags |= IEEE80211_TX_INTFL_NEED_TXPROCESSING;
1695 			info->control.vif = &rx->sdata->vif;
1696 			skb_set_queue_mapping(skb,
1697 				ieee80211_select_queue(rx->sdata, fwd_skb));
1698 			ieee80211_set_qos_hdr(local, skb);
1699 			if (is_multicast_ether_addr(fwd_hdr->addr1))
1700 				IEEE80211_IFSTA_MESH_CTR_INC(&sdata->u.mesh,
1701 								fwded_mcast);
1702 			else {
1703 				int err;
1704 				/*
1705 				 * Save TA to addr1 to send TA a path error if a
1706 				 * suitable next hop is not found
1707 				 */
1708 				memcpy(fwd_hdr->addr1, fwd_hdr->addr2,
1709 						ETH_ALEN);
1710 				err = mesh_nexthop_lookup(fwd_skb, sdata);
1711 				/* Failed to immediately resolve next hop:
1712 				 * fwded frame was dropped or will be added
1713 				 * later to the pending skb queue.  */
1714 				if (err)
1715 					return RX_DROP_MONITOR;
1716 
1717 				IEEE80211_IFSTA_MESH_CTR_INC(&sdata->u.mesh,
1718 								fwded_unicast);
1719 			}
1720 			IEEE80211_IFSTA_MESH_CTR_INC(&sdata->u.mesh,
1721 						     fwded_frames);
1722 			ieee80211_add_pending_skb(local, fwd_skb);
1723 		}
1724 	}
1725 
1726 	if (is_multicast_ether_addr(hdr->addr1) ||
1727 	    sdata->dev->flags & IFF_PROMISC)
1728 		return RX_CONTINUE;
1729 	else
1730 		return RX_DROP_MONITOR;
1731 }
1732 #endif
1733 
1734 static ieee80211_rx_result debug_noinline
1735 ieee80211_rx_h_data(struct ieee80211_rx_data *rx)
1736 {
1737 	struct ieee80211_sub_if_data *sdata = rx->sdata;
1738 	struct ieee80211_local *local = rx->local;
1739 	struct net_device *dev = sdata->dev;
1740 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
1741 	__le16 fc = hdr->frame_control;
1742 	int err;
1743 
1744 	if (unlikely(!ieee80211_is_data(hdr->frame_control)))
1745 		return RX_CONTINUE;
1746 
1747 	if (unlikely(!ieee80211_is_data_present(hdr->frame_control)))
1748 		return RX_DROP_MONITOR;
1749 
1750 	/*
1751 	 * Allow the cooked monitor interface of an AP to see 4-addr frames so
1752 	 * that a 4-addr station can be detected and moved into a separate VLAN
1753 	 */
1754 	if (ieee80211_has_a4(hdr->frame_control) &&
1755 	    sdata->vif.type == NL80211_IFTYPE_AP)
1756 		return RX_DROP_MONITOR;
1757 
1758 	err = __ieee80211_data_to_8023(rx);
1759 	if (unlikely(err))
1760 		return RX_DROP_UNUSABLE;
1761 
1762 	if (!ieee80211_frame_allowed(rx, fc))
1763 		return RX_DROP_MONITOR;
1764 
1765 	rx->skb->dev = dev;
1766 
1767 	dev->stats.rx_packets++;
1768 	dev->stats.rx_bytes += rx->skb->len;
1769 
1770 	if (ieee80211_is_data(hdr->frame_control) &&
1771 	    !is_multicast_ether_addr(hdr->addr1) &&
1772 	    local->hw.conf.dynamic_ps_timeout > 0 && local->ps_sdata) {
1773 			mod_timer(&local->dynamic_ps_timer, jiffies +
1774 			 msecs_to_jiffies(local->hw.conf.dynamic_ps_timeout));
1775 	}
1776 
1777 	ieee80211_deliver_skb(rx);
1778 
1779 	return RX_QUEUED;
1780 }
1781 
1782 static ieee80211_rx_result debug_noinline
1783 ieee80211_rx_h_ctrl(struct ieee80211_rx_data *rx, struct sk_buff_head *frames)
1784 {
1785 	struct ieee80211_local *local = rx->local;
1786 	struct ieee80211_hw *hw = &local->hw;
1787 	struct sk_buff *skb = rx->skb;
1788 	struct ieee80211_bar *bar = (struct ieee80211_bar *)skb->data;
1789 	struct tid_ampdu_rx *tid_agg_rx;
1790 	u16 start_seq_num;
1791 	u16 tid;
1792 
1793 	if (likely(!ieee80211_is_ctl(bar->frame_control)))
1794 		return RX_CONTINUE;
1795 
1796 	if (ieee80211_is_back_req(bar->frame_control)) {
1797 		if (!rx->sta)
1798 			return RX_DROP_MONITOR;
1799 		tid = le16_to_cpu(bar->control) >> 12;
1800 		if (rx->sta->ampdu_mlme.tid_state_rx[tid]
1801 					!= HT_AGG_STATE_OPERATIONAL)
1802 			return RX_DROP_MONITOR;
1803 		tid_agg_rx = rx->sta->ampdu_mlme.tid_rx[tid];
1804 
1805 		start_seq_num = le16_to_cpu(bar->start_seq_num) >> 4;
1806 
1807 		/* reset session timer */
1808 		if (tid_agg_rx->timeout)
1809 			mod_timer(&tid_agg_rx->session_timer,
1810 				  TU_TO_EXP_TIME(tid_agg_rx->timeout));
1811 
1812 		/* release stored frames up to start of BAR */
1813 		ieee80211_release_reorder_frames(hw, tid_agg_rx, start_seq_num,
1814 						 frames);
1815 		kfree_skb(skb);
1816 		return RX_QUEUED;
1817 	}
1818 
1819 	return RX_CONTINUE;
1820 }
1821 
1822 static void ieee80211_process_sa_query_req(struct ieee80211_sub_if_data *sdata,
1823 					   struct ieee80211_mgmt *mgmt,
1824 					   size_t len)
1825 {
1826 	struct ieee80211_local *local = sdata->local;
1827 	struct sk_buff *skb;
1828 	struct ieee80211_mgmt *resp;
1829 
1830 	if (compare_ether_addr(mgmt->da, sdata->vif.addr) != 0) {
1831 		/* Not to own unicast address */
1832 		return;
1833 	}
1834 
1835 	if (compare_ether_addr(mgmt->sa, sdata->u.mgd.bssid) != 0 ||
1836 	    compare_ether_addr(mgmt->bssid, sdata->u.mgd.bssid) != 0) {
1837 		/* Not from the current AP or not associated yet. */
1838 		return;
1839 	}
1840 
1841 	if (len < 24 + 1 + sizeof(resp->u.action.u.sa_query)) {
1842 		/* Too short SA Query request frame */
1843 		return;
1844 	}
1845 
1846 	skb = dev_alloc_skb(sizeof(*resp) + local->hw.extra_tx_headroom);
1847 	if (skb == NULL)
1848 		return;
1849 
1850 	skb_reserve(skb, local->hw.extra_tx_headroom);
1851 	resp = (struct ieee80211_mgmt *) skb_put(skb, 24);
1852 	memset(resp, 0, 24);
1853 	memcpy(resp->da, mgmt->sa, ETH_ALEN);
1854 	memcpy(resp->sa, sdata->vif.addr, ETH_ALEN);
1855 	memcpy(resp->bssid, sdata->u.mgd.bssid, ETH_ALEN);
1856 	resp->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
1857 					  IEEE80211_STYPE_ACTION);
1858 	skb_put(skb, 1 + sizeof(resp->u.action.u.sa_query));
1859 	resp->u.action.category = WLAN_CATEGORY_SA_QUERY;
1860 	resp->u.action.u.sa_query.action = WLAN_ACTION_SA_QUERY_RESPONSE;
1861 	memcpy(resp->u.action.u.sa_query.trans_id,
1862 	       mgmt->u.action.u.sa_query.trans_id,
1863 	       WLAN_SA_QUERY_TR_ID_LEN);
1864 
1865 	ieee80211_tx_skb(sdata, skb);
1866 }
1867 
1868 static ieee80211_rx_result debug_noinline
1869 ieee80211_rx_h_action(struct ieee80211_rx_data *rx)
1870 {
1871 	struct ieee80211_local *local = rx->local;
1872 	struct ieee80211_sub_if_data *sdata = rx->sdata;
1873 	struct ieee80211_mgmt *mgmt = (struct ieee80211_mgmt *) rx->skb->data;
1874 	struct sk_buff *nskb;
1875 	struct ieee80211_rx_status *status;
1876 	int len = rx->skb->len;
1877 
1878 	if (!ieee80211_is_action(mgmt->frame_control))
1879 		return RX_CONTINUE;
1880 
1881 	/* drop too small frames */
1882 	if (len < IEEE80211_MIN_ACTION_SIZE)
1883 		return RX_DROP_UNUSABLE;
1884 
1885 	if (!rx->sta && mgmt->u.action.category != WLAN_CATEGORY_PUBLIC)
1886 		return RX_DROP_UNUSABLE;
1887 
1888 	if (!(rx->flags & IEEE80211_RX_RA_MATCH))
1889 		return RX_DROP_UNUSABLE;
1890 
1891 	if (ieee80211_drop_unencrypted_mgmt(rx))
1892 		return RX_DROP_UNUSABLE;
1893 
1894 	switch (mgmt->u.action.category) {
1895 	case WLAN_CATEGORY_BACK:
1896 		/*
1897 		 * The aggregation code is not prepared to handle
1898 		 * anything but STA/AP due to the BSSID handling;
1899 		 * IBSS could work in the code but isn't supported
1900 		 * by drivers or the standard.
1901 		 */
1902 		if (sdata->vif.type != NL80211_IFTYPE_STATION &&
1903 		    sdata->vif.type != NL80211_IFTYPE_AP_VLAN &&
1904 		    sdata->vif.type != NL80211_IFTYPE_AP)
1905 			break;
1906 
1907 		/* verify action_code is present */
1908 		if (len < IEEE80211_MIN_ACTION_SIZE + 1)
1909 			break;
1910 
1911 		switch (mgmt->u.action.u.addba_req.action_code) {
1912 		case WLAN_ACTION_ADDBA_REQ:
1913 			if (len < (IEEE80211_MIN_ACTION_SIZE +
1914 				   sizeof(mgmt->u.action.u.addba_req)))
1915 				return RX_DROP_MONITOR;
1916 			ieee80211_process_addba_request(local, rx->sta, mgmt, len);
1917 			goto handled;
1918 		case WLAN_ACTION_ADDBA_RESP:
1919 			if (len < (IEEE80211_MIN_ACTION_SIZE +
1920 				   sizeof(mgmt->u.action.u.addba_resp)))
1921 				break;
1922 			ieee80211_process_addba_resp(local, rx->sta, mgmt, len);
1923 			goto handled;
1924 		case WLAN_ACTION_DELBA:
1925 			if (len < (IEEE80211_MIN_ACTION_SIZE +
1926 				   sizeof(mgmt->u.action.u.delba)))
1927 				break;
1928 			ieee80211_process_delba(sdata, rx->sta, mgmt, len);
1929 			goto handled;
1930 		}
1931 		break;
1932 	case WLAN_CATEGORY_SPECTRUM_MGMT:
1933 		if (local->hw.conf.channel->band != IEEE80211_BAND_5GHZ)
1934 			break;
1935 
1936 		if (sdata->vif.type != NL80211_IFTYPE_STATION)
1937 			break;
1938 
1939 		/* verify action_code is present */
1940 		if (len < IEEE80211_MIN_ACTION_SIZE + 1)
1941 			break;
1942 
1943 		switch (mgmt->u.action.u.measurement.action_code) {
1944 		case WLAN_ACTION_SPCT_MSR_REQ:
1945 			if (len < (IEEE80211_MIN_ACTION_SIZE +
1946 				   sizeof(mgmt->u.action.u.measurement)))
1947 				break;
1948 			ieee80211_process_measurement_req(sdata, mgmt, len);
1949 			goto handled;
1950 		case WLAN_ACTION_SPCT_CHL_SWITCH:
1951 			if (len < (IEEE80211_MIN_ACTION_SIZE +
1952 				   sizeof(mgmt->u.action.u.chan_switch)))
1953 				break;
1954 
1955 			if (sdata->vif.type != NL80211_IFTYPE_STATION)
1956 				break;
1957 
1958 			if (memcmp(mgmt->bssid, sdata->u.mgd.bssid, ETH_ALEN))
1959 				break;
1960 
1961 			return ieee80211_sta_rx_mgmt(sdata, rx->skb);
1962 		}
1963 		break;
1964 	case WLAN_CATEGORY_SA_QUERY:
1965 		if (len < (IEEE80211_MIN_ACTION_SIZE +
1966 			   sizeof(mgmt->u.action.u.sa_query)))
1967 			break;
1968 
1969 		switch (mgmt->u.action.u.sa_query.action) {
1970 		case WLAN_ACTION_SA_QUERY_REQUEST:
1971 			if (sdata->vif.type != NL80211_IFTYPE_STATION)
1972 				break;
1973 			ieee80211_process_sa_query_req(sdata, mgmt, len);
1974 			goto handled;
1975 		}
1976 		break;
1977 	case MESH_PLINK_CATEGORY:
1978 	case MESH_PATH_SEL_CATEGORY:
1979 		if (ieee80211_vif_is_mesh(&sdata->vif))
1980 			return ieee80211_mesh_rx_mgmt(sdata, rx->skb);
1981 		break;
1982 	}
1983 
1984 	/*
1985 	 * For AP mode, hostapd is responsible for handling any action
1986 	 * frames that we didn't handle, including returning unknown
1987 	 * ones. For all other modes we will return them to the sender,
1988 	 * setting the 0x80 bit in the action category, as required by
1989 	 * 802.11-2007 7.3.1.11.
1990 	 */
1991 	if (sdata->vif.type == NL80211_IFTYPE_AP ||
1992 	    sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
1993 		return RX_DROP_MONITOR;
1994 
1995 	/*
1996 	 * Getting here means the kernel doesn't know how to handle
1997 	 * it, but maybe userspace does ... include returned frames
1998 	 * so userspace can register for those to know whether ones
1999 	 * it transmitted were processed or returned.
2000 	 */
2001 	status = IEEE80211_SKB_RXCB(rx->skb);
2002 
2003 	if (sdata->vif.type == NL80211_IFTYPE_STATION &&
2004 	    cfg80211_rx_action(rx->sdata->dev, status->freq,
2005 			       rx->skb->data, rx->skb->len,
2006 			       GFP_ATOMIC))
2007 		goto handled;
2008 
2009 	/* do not return rejected action frames */
2010 	if (mgmt->u.action.category & 0x80)
2011 		return RX_DROP_UNUSABLE;
2012 
2013 	nskb = skb_copy_expand(rx->skb, local->hw.extra_tx_headroom, 0,
2014 			       GFP_ATOMIC);
2015 	if (nskb) {
2016 		struct ieee80211_mgmt *mgmt = (void *)nskb->data;
2017 
2018 		mgmt->u.action.category |= 0x80;
2019 		memcpy(mgmt->da, mgmt->sa, ETH_ALEN);
2020 		memcpy(mgmt->sa, rx->sdata->vif.addr, ETH_ALEN);
2021 
2022 		memset(nskb->cb, 0, sizeof(nskb->cb));
2023 
2024 		ieee80211_tx_skb(rx->sdata, nskb);
2025 	}
2026 
2027  handled:
2028 	if (rx->sta)
2029 		rx->sta->rx_packets++;
2030 	dev_kfree_skb(rx->skb);
2031 	return RX_QUEUED;
2032 }
2033 
2034 static ieee80211_rx_result debug_noinline
2035 ieee80211_rx_h_mgmt(struct ieee80211_rx_data *rx)
2036 {
2037 	struct ieee80211_sub_if_data *sdata = rx->sdata;
2038 	ieee80211_rx_result rxs;
2039 
2040 	if (!(rx->flags & IEEE80211_RX_RA_MATCH))
2041 		return RX_DROP_MONITOR;
2042 
2043 	if (ieee80211_drop_unencrypted_mgmt(rx))
2044 		return RX_DROP_UNUSABLE;
2045 
2046 	rxs = ieee80211_work_rx_mgmt(rx->sdata, rx->skb);
2047 	if (rxs != RX_CONTINUE)
2048 		return rxs;
2049 
2050 	if (ieee80211_vif_is_mesh(&sdata->vif))
2051 		return ieee80211_mesh_rx_mgmt(sdata, rx->skb);
2052 
2053 	if (sdata->vif.type == NL80211_IFTYPE_ADHOC)
2054 		return ieee80211_ibss_rx_mgmt(sdata, rx->skb);
2055 
2056 	if (sdata->vif.type == NL80211_IFTYPE_STATION)
2057 		return ieee80211_sta_rx_mgmt(sdata, rx->skb);
2058 
2059 	return RX_DROP_MONITOR;
2060 }
2061 
2062 static void ieee80211_rx_michael_mic_report(struct ieee80211_hdr *hdr,
2063 					    struct ieee80211_rx_data *rx)
2064 {
2065 	int keyidx;
2066 	unsigned int hdrlen;
2067 
2068 	hdrlen = ieee80211_hdrlen(hdr->frame_control);
2069 	if (rx->skb->len >= hdrlen + 4)
2070 		keyidx = rx->skb->data[hdrlen + 3] >> 6;
2071 	else
2072 		keyidx = -1;
2073 
2074 	if (!rx->sta) {
2075 		/*
2076 		 * Some hardware seem to generate incorrect Michael MIC
2077 		 * reports; ignore them to avoid triggering countermeasures.
2078 		 */
2079 		return;
2080 	}
2081 
2082 	if (!ieee80211_has_protected(hdr->frame_control))
2083 		return;
2084 
2085 	if (rx->sdata->vif.type == NL80211_IFTYPE_AP && keyidx) {
2086 		/*
2087 		 * APs with pairwise keys should never receive Michael MIC
2088 		 * errors for non-zero keyidx because these are reserved for
2089 		 * group keys and only the AP is sending real multicast
2090 		 * frames in the BSS.
2091 		 */
2092 		return;
2093 	}
2094 
2095 	if (!ieee80211_is_data(hdr->frame_control) &&
2096 	    !ieee80211_is_auth(hdr->frame_control))
2097 		return;
2098 
2099 	mac80211_ev_michael_mic_failure(rx->sdata, keyidx, hdr, NULL,
2100 					GFP_ATOMIC);
2101 }
2102 
2103 /* TODO: use IEEE80211_RX_FRAGMENTED */
2104 static void ieee80211_rx_cooked_monitor(struct ieee80211_rx_data *rx,
2105 					struct ieee80211_rate *rate)
2106 {
2107 	struct ieee80211_sub_if_data *sdata;
2108 	struct ieee80211_local *local = rx->local;
2109 	struct ieee80211_rtap_hdr {
2110 		struct ieee80211_radiotap_header hdr;
2111 		u8 flags;
2112 		u8 rate_or_pad;
2113 		__le16 chan_freq;
2114 		__le16 chan_flags;
2115 	} __attribute__ ((packed)) *rthdr;
2116 	struct sk_buff *skb = rx->skb, *skb2;
2117 	struct net_device *prev_dev = NULL;
2118 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
2119 
2120 	if (status->flag & RX_FLAG_INTERNAL_CMTR)
2121 		goto out_free_skb;
2122 
2123 	if (skb_headroom(skb) < sizeof(*rthdr) &&
2124 	    pskb_expand_head(skb, sizeof(*rthdr), 0, GFP_ATOMIC))
2125 		goto out_free_skb;
2126 
2127 	rthdr = (void *)skb_push(skb, sizeof(*rthdr));
2128 	memset(rthdr, 0, sizeof(*rthdr));
2129 	rthdr->hdr.it_len = cpu_to_le16(sizeof(*rthdr));
2130 	rthdr->hdr.it_present =
2131 		cpu_to_le32((1 << IEEE80211_RADIOTAP_FLAGS) |
2132 			    (1 << IEEE80211_RADIOTAP_CHANNEL));
2133 
2134 	if (rate) {
2135 		rthdr->rate_or_pad = rate->bitrate / 5;
2136 		rthdr->hdr.it_present |=
2137 			cpu_to_le32(1 << IEEE80211_RADIOTAP_RATE);
2138 	}
2139 	rthdr->chan_freq = cpu_to_le16(status->freq);
2140 
2141 	if (status->band == IEEE80211_BAND_5GHZ)
2142 		rthdr->chan_flags = cpu_to_le16(IEEE80211_CHAN_OFDM |
2143 						IEEE80211_CHAN_5GHZ);
2144 	else
2145 		rthdr->chan_flags = cpu_to_le16(IEEE80211_CHAN_DYN |
2146 						IEEE80211_CHAN_2GHZ);
2147 
2148 	skb_set_mac_header(skb, 0);
2149 	skb->ip_summed = CHECKSUM_UNNECESSARY;
2150 	skb->pkt_type = PACKET_OTHERHOST;
2151 	skb->protocol = htons(ETH_P_802_2);
2152 
2153 	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
2154 		if (!ieee80211_sdata_running(sdata))
2155 			continue;
2156 
2157 		if (sdata->vif.type != NL80211_IFTYPE_MONITOR ||
2158 		    !(sdata->u.mntr_flags & MONITOR_FLAG_COOK_FRAMES))
2159 			continue;
2160 
2161 		if (prev_dev) {
2162 			skb2 = skb_clone(skb, GFP_ATOMIC);
2163 			if (skb2) {
2164 				skb2->dev = prev_dev;
2165 				netif_rx(skb2);
2166 			}
2167 		}
2168 
2169 		prev_dev = sdata->dev;
2170 		sdata->dev->stats.rx_packets++;
2171 		sdata->dev->stats.rx_bytes += skb->len;
2172 	}
2173 
2174 	if (prev_dev) {
2175 		skb->dev = prev_dev;
2176 		netif_rx(skb);
2177 		skb = NULL;
2178 	} else
2179 		goto out_free_skb;
2180 
2181 	status->flag |= RX_FLAG_INTERNAL_CMTR;
2182 	return;
2183 
2184  out_free_skb:
2185 	dev_kfree_skb(skb);
2186 }
2187 
2188 
2189 static void ieee80211_invoke_rx_handlers(struct ieee80211_sub_if_data *sdata,
2190 					 struct ieee80211_rx_data *rx,
2191 					 struct sk_buff *skb,
2192 					 struct ieee80211_rate *rate)
2193 {
2194 	struct sk_buff_head reorder_release;
2195 	ieee80211_rx_result res = RX_DROP_MONITOR;
2196 
2197 	__skb_queue_head_init(&reorder_release);
2198 
2199 	rx->skb = skb;
2200 	rx->sdata = sdata;
2201 
2202 #define CALL_RXH(rxh)			\
2203 	do {				\
2204 		res = rxh(rx);		\
2205 		if (res != RX_CONTINUE)	\
2206 			goto rxh_next;  \
2207 	} while (0);
2208 
2209 	/*
2210 	 * NB: the rxh_next label works even if we jump
2211 	 *     to it from here because then the list will
2212 	 *     be empty, which is a trivial check
2213 	 */
2214 	CALL_RXH(ieee80211_rx_h_passive_scan)
2215 	CALL_RXH(ieee80211_rx_h_check)
2216 
2217 	ieee80211_rx_reorder_ampdu(rx, &reorder_release);
2218 
2219 	while ((skb = __skb_dequeue(&reorder_release))) {
2220 		/*
2221 		 * all the other fields are valid across frames
2222 		 * that belong to an aMPDU since they are on the
2223 		 * same TID from the same station
2224 		 */
2225 		rx->skb = skb;
2226 
2227 		CALL_RXH(ieee80211_rx_h_decrypt)
2228 		CALL_RXH(ieee80211_rx_h_check_more_data)
2229 		CALL_RXH(ieee80211_rx_h_sta_process)
2230 		CALL_RXH(ieee80211_rx_h_defragment)
2231 		CALL_RXH(ieee80211_rx_h_ps_poll)
2232 		CALL_RXH(ieee80211_rx_h_michael_mic_verify)
2233 		/* must be after MMIC verify so header is counted in MPDU mic */
2234 		CALL_RXH(ieee80211_rx_h_remove_qos_control)
2235 		CALL_RXH(ieee80211_rx_h_amsdu)
2236 #ifdef CONFIG_MAC80211_MESH
2237 		if (ieee80211_vif_is_mesh(&sdata->vif))
2238 			CALL_RXH(ieee80211_rx_h_mesh_fwding);
2239 #endif
2240 		CALL_RXH(ieee80211_rx_h_data)
2241 
2242 		/* special treatment -- needs the queue */
2243 		res = ieee80211_rx_h_ctrl(rx, &reorder_release);
2244 		if (res != RX_CONTINUE)
2245 			goto rxh_next;
2246 
2247 		CALL_RXH(ieee80211_rx_h_action)
2248 		CALL_RXH(ieee80211_rx_h_mgmt)
2249 
2250 #undef CALL_RXH
2251 
2252  rxh_next:
2253 		switch (res) {
2254 		case RX_DROP_MONITOR:
2255 			I802_DEBUG_INC(sdata->local->rx_handlers_drop);
2256 			if (rx->sta)
2257 				rx->sta->rx_dropped++;
2258 			/* fall through */
2259 		case RX_CONTINUE:
2260 			ieee80211_rx_cooked_monitor(rx, rate);
2261 			break;
2262 		case RX_DROP_UNUSABLE:
2263 			I802_DEBUG_INC(sdata->local->rx_handlers_drop);
2264 			if (rx->sta)
2265 				rx->sta->rx_dropped++;
2266 			dev_kfree_skb(rx->skb);
2267 			break;
2268 		case RX_QUEUED:
2269 			I802_DEBUG_INC(sdata->local->rx_handlers_queued);
2270 			break;
2271 		}
2272 	}
2273 }
2274 
2275 /* main receive path */
2276 
2277 static int prepare_for_handlers(struct ieee80211_sub_if_data *sdata,
2278 				struct ieee80211_rx_data *rx,
2279 				struct ieee80211_hdr *hdr)
2280 {
2281 	struct sk_buff *skb = rx->skb;
2282 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
2283 	u8 *bssid = ieee80211_get_bssid(hdr, skb->len, sdata->vif.type);
2284 	int multicast = is_multicast_ether_addr(hdr->addr1);
2285 
2286 	switch (sdata->vif.type) {
2287 	case NL80211_IFTYPE_STATION:
2288 		if (!bssid && !sdata->u.mgd.use_4addr)
2289 			return 0;
2290 		if (!multicast &&
2291 		    compare_ether_addr(sdata->vif.addr, hdr->addr1) != 0) {
2292 			if (!(sdata->dev->flags & IFF_PROMISC))
2293 				return 0;
2294 			rx->flags &= ~IEEE80211_RX_RA_MATCH;
2295 		}
2296 		break;
2297 	case NL80211_IFTYPE_ADHOC:
2298 		if (!bssid)
2299 			return 0;
2300 		if (ieee80211_is_beacon(hdr->frame_control)) {
2301 			return 1;
2302 		}
2303 		else if (!ieee80211_bssid_match(bssid, sdata->u.ibss.bssid)) {
2304 			if (!(rx->flags & IEEE80211_RX_IN_SCAN))
2305 				return 0;
2306 			rx->flags &= ~IEEE80211_RX_RA_MATCH;
2307 		} else if (!multicast &&
2308 			   compare_ether_addr(sdata->vif.addr,
2309 					      hdr->addr1) != 0) {
2310 			if (!(sdata->dev->flags & IFF_PROMISC))
2311 				return 0;
2312 			rx->flags &= ~IEEE80211_RX_RA_MATCH;
2313 		} else if (!rx->sta) {
2314 			int rate_idx;
2315 			if (status->flag & RX_FLAG_HT)
2316 				rate_idx = 0; /* TODO: HT rates */
2317 			else
2318 				rate_idx = status->rate_idx;
2319 			rx->sta = ieee80211_ibss_add_sta(sdata, bssid,
2320 					hdr->addr2, BIT(rate_idx), GFP_ATOMIC);
2321 		}
2322 		break;
2323 	case NL80211_IFTYPE_MESH_POINT:
2324 		if (!multicast &&
2325 		    compare_ether_addr(sdata->vif.addr,
2326 				       hdr->addr1) != 0) {
2327 			if (!(sdata->dev->flags & IFF_PROMISC))
2328 				return 0;
2329 
2330 			rx->flags &= ~IEEE80211_RX_RA_MATCH;
2331 		}
2332 		break;
2333 	case NL80211_IFTYPE_AP_VLAN:
2334 	case NL80211_IFTYPE_AP:
2335 		if (!bssid) {
2336 			if (compare_ether_addr(sdata->vif.addr,
2337 					       hdr->addr1))
2338 				return 0;
2339 		} else if (!ieee80211_bssid_match(bssid,
2340 					sdata->vif.addr)) {
2341 			if (!(rx->flags & IEEE80211_RX_IN_SCAN))
2342 				return 0;
2343 			rx->flags &= ~IEEE80211_RX_RA_MATCH;
2344 		}
2345 		break;
2346 	case NL80211_IFTYPE_WDS:
2347 		if (bssid || !ieee80211_is_data(hdr->frame_control))
2348 			return 0;
2349 		if (compare_ether_addr(sdata->u.wds.remote_addr, hdr->addr2))
2350 			return 0;
2351 		break;
2352 	case NL80211_IFTYPE_MONITOR:
2353 	case NL80211_IFTYPE_UNSPECIFIED:
2354 	case __NL80211_IFTYPE_AFTER_LAST:
2355 		/* should never get here */
2356 		WARN_ON(1);
2357 		break;
2358 	}
2359 
2360 	return 1;
2361 }
2362 
2363 /*
2364  * This is the actual Rx frames handler. as it blongs to Rx path it must
2365  * be called with rcu_read_lock protection.
2366  */
2367 static void __ieee80211_rx_handle_packet(struct ieee80211_hw *hw,
2368 					 struct sk_buff *skb,
2369 					 struct ieee80211_rate *rate)
2370 {
2371 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
2372 	struct ieee80211_local *local = hw_to_local(hw);
2373 	struct ieee80211_sub_if_data *sdata;
2374 	struct ieee80211_hdr *hdr;
2375 	struct ieee80211_rx_data rx;
2376 	int prepares;
2377 	struct ieee80211_sub_if_data *prev = NULL;
2378 	struct sk_buff *skb_new;
2379 	struct sta_info *sta, *tmp;
2380 	bool found_sta = false;
2381 
2382 	hdr = (struct ieee80211_hdr *)skb->data;
2383 	memset(&rx, 0, sizeof(rx));
2384 	rx.skb = skb;
2385 	rx.local = local;
2386 
2387 	if (ieee80211_is_data(hdr->frame_control) || ieee80211_is_mgmt(hdr->frame_control))
2388 		local->dot11ReceivedFragmentCount++;
2389 
2390 	if (unlikely(test_bit(SCAN_HW_SCANNING, &local->scanning) ||
2391 		     test_bit(SCAN_OFF_CHANNEL, &local->scanning)))
2392 		rx.flags |= IEEE80211_RX_IN_SCAN;
2393 
2394 	ieee80211_parse_qos(&rx);
2395 	ieee80211_verify_alignment(&rx);
2396 
2397 	if (ieee80211_is_data(hdr->frame_control)) {
2398 		for_each_sta_info(local, hdr->addr2, sta, tmp) {
2399 			rx.sta = sta;
2400 			found_sta = true;
2401 			rx.sdata = sta->sdata;
2402 
2403 			rx.flags |= IEEE80211_RX_RA_MATCH;
2404 			prepares = prepare_for_handlers(rx.sdata, &rx, hdr);
2405 			if (prepares) {
2406 				if (status->flag & RX_FLAG_MMIC_ERROR) {
2407 					if (rx.flags & IEEE80211_RX_RA_MATCH)
2408 						ieee80211_rx_michael_mic_report(hdr, &rx);
2409 				} else
2410 					prev = rx.sdata;
2411 			}
2412 		}
2413 	}
2414 	if (!found_sta) {
2415 		list_for_each_entry_rcu(sdata, &local->interfaces, list) {
2416 			if (!ieee80211_sdata_running(sdata))
2417 				continue;
2418 
2419 			if (sdata->vif.type == NL80211_IFTYPE_MONITOR ||
2420 			    sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
2421 				continue;
2422 
2423 			/*
2424 			 * frame is destined for this interface, but if it's
2425 			 * not also for the previous one we handle that after
2426 			 * the loop to avoid copying the SKB once too much
2427 			 */
2428 
2429 			if (!prev) {
2430 				prev = sdata;
2431 				continue;
2432 			}
2433 
2434 			rx.sta = sta_info_get_bss(prev, hdr->addr2);
2435 
2436 			rx.flags |= IEEE80211_RX_RA_MATCH;
2437 			prepares = prepare_for_handlers(prev, &rx, hdr);
2438 
2439 			if (!prepares)
2440 				goto next;
2441 
2442 			if (status->flag & RX_FLAG_MMIC_ERROR) {
2443 				rx.sdata = prev;
2444 				if (rx.flags & IEEE80211_RX_RA_MATCH)
2445 					ieee80211_rx_michael_mic_report(hdr,
2446 									&rx);
2447 				goto next;
2448 			}
2449 
2450 			/*
2451 			 * frame was destined for the previous interface
2452 			 * so invoke RX handlers for it
2453 			 */
2454 
2455 			skb_new = skb_copy(skb, GFP_ATOMIC);
2456 			if (!skb_new) {
2457 				if (net_ratelimit())
2458 					printk(KERN_DEBUG "%s: failed to copy "
2459 					       "multicast frame for %s\n",
2460 					       wiphy_name(local->hw.wiphy),
2461 					       prev->name);
2462 				goto next;
2463 			}
2464 			ieee80211_invoke_rx_handlers(prev, &rx, skb_new, rate);
2465 next:
2466 			prev = sdata;
2467 		}
2468 
2469 		if (prev) {
2470 			rx.sta = sta_info_get_bss(prev, hdr->addr2);
2471 
2472 			rx.flags |= IEEE80211_RX_RA_MATCH;
2473 			prepares = prepare_for_handlers(prev, &rx, hdr);
2474 
2475 			if (!prepares)
2476 				prev = NULL;
2477 		}
2478 	}
2479 	if (prev)
2480 		ieee80211_invoke_rx_handlers(prev, &rx, skb, rate);
2481 	else
2482 		dev_kfree_skb(skb);
2483 }
2484 
2485 /*
2486  * This is the receive path handler. It is called by a low level driver when an
2487  * 802.11 MPDU is received from the hardware.
2488  */
2489 void ieee80211_rx(struct ieee80211_hw *hw, struct sk_buff *skb)
2490 {
2491 	struct ieee80211_local *local = hw_to_local(hw);
2492 	struct ieee80211_rate *rate = NULL;
2493 	struct ieee80211_supported_band *sband;
2494 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
2495 
2496 	WARN_ON_ONCE(softirq_count() == 0);
2497 
2498 	if (WARN_ON(status->band < 0 ||
2499 		    status->band >= IEEE80211_NUM_BANDS))
2500 		goto drop;
2501 
2502 	sband = local->hw.wiphy->bands[status->band];
2503 	if (WARN_ON(!sband))
2504 		goto drop;
2505 
2506 	/*
2507 	 * If we're suspending, it is possible although not too likely
2508 	 * that we'd be receiving frames after having already partially
2509 	 * quiesced the stack. We can't process such frames then since
2510 	 * that might, for example, cause stations to be added or other
2511 	 * driver callbacks be invoked.
2512 	 */
2513 	if (unlikely(local->quiescing || local->suspended))
2514 		goto drop;
2515 
2516 	/*
2517 	 * The same happens when we're not even started,
2518 	 * but that's worth a warning.
2519 	 */
2520 	if (WARN_ON(!local->started))
2521 		goto drop;
2522 
2523 	if (status->flag & RX_FLAG_HT) {
2524 		/*
2525 		 * rate_idx is MCS index, which can be [0-76] as documented on:
2526 		 *
2527 		 * http://wireless.kernel.org/en/developers/Documentation/ieee80211/802.11n
2528 		 *
2529 		 * Anything else would be some sort of driver or hardware error.
2530 		 * The driver should catch hardware errors.
2531 		 */
2532 		if (WARN((status->rate_idx < 0 ||
2533 			 status->rate_idx > 76),
2534 			 "Rate marked as an HT rate but passed "
2535 			 "status->rate_idx is not "
2536 			 "an MCS index [0-76]: %d (0x%02x)\n",
2537 			 status->rate_idx,
2538 			 status->rate_idx))
2539 			goto drop;
2540 	} else {
2541 		if (WARN_ON(status->rate_idx < 0 ||
2542 			    status->rate_idx >= sband->n_bitrates))
2543 			goto drop;
2544 		rate = &sband->bitrates[status->rate_idx];
2545 	}
2546 
2547 	/*
2548 	 * key references and virtual interfaces are protected using RCU
2549 	 * and this requires that we are in a read-side RCU section during
2550 	 * receive processing
2551 	 */
2552 	rcu_read_lock();
2553 
2554 	/*
2555 	 * Frames with failed FCS/PLCP checksum are not returned,
2556 	 * all other frames are returned without radiotap header
2557 	 * if it was previously present.
2558 	 * Also, frames with less than 16 bytes are dropped.
2559 	 */
2560 	skb = ieee80211_rx_monitor(local, skb, rate);
2561 	if (!skb) {
2562 		rcu_read_unlock();
2563 		return;
2564 	}
2565 
2566 	__ieee80211_rx_handle_packet(hw, skb, rate);
2567 
2568 	rcu_read_unlock();
2569 
2570 	return;
2571  drop:
2572 	kfree_skb(skb);
2573 }
2574 EXPORT_SYMBOL(ieee80211_rx);
2575 
2576 /* This is a version of the rx handler that can be called from hard irq
2577  * context. Post the skb on the queue and schedule the tasklet */
2578 void ieee80211_rx_irqsafe(struct ieee80211_hw *hw, struct sk_buff *skb)
2579 {
2580 	struct ieee80211_local *local = hw_to_local(hw);
2581 
2582 	BUILD_BUG_ON(sizeof(struct ieee80211_rx_status) > sizeof(skb->cb));
2583 
2584 	skb->pkt_type = IEEE80211_RX_MSG;
2585 	skb_queue_tail(&local->skb_queue, skb);
2586 	tasklet_schedule(&local->tasklet);
2587 }
2588 EXPORT_SYMBOL(ieee80211_rx_irqsafe);
2589