xref: /openbmc/linux/net/mac80211/rx.c (revision b6dcefde)
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	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/kernel.h>
14 #include <linux/skbuff.h>
15 #include <linux/netdevice.h>
16 #include <linux/etherdevice.h>
17 #include <linux/rcupdate.h>
18 #include <net/mac80211.h>
19 #include <net/ieee80211_radiotap.h>
20 
21 #include "ieee80211_i.h"
22 #include "driver-ops.h"
23 #include "led.h"
24 #include "mesh.h"
25 #include "wep.h"
26 #include "wpa.h"
27 #include "tkip.h"
28 #include "wme.h"
29 
30 /*
31  * monitor mode reception
32  *
33  * This function cleans up the SKB, i.e. it removes all the stuff
34  * only useful for monitoring.
35  */
36 static struct sk_buff *remove_monitor_info(struct ieee80211_local *local,
37 					   struct sk_buff *skb)
38 {
39 	if (local->hw.flags & IEEE80211_HW_RX_INCLUDES_FCS) {
40 		if (likely(skb->len > FCS_LEN))
41 			skb_trim(skb, skb->len - FCS_LEN);
42 		else {
43 			/* driver bug */
44 			WARN_ON(1);
45 			dev_kfree_skb(skb);
46 			skb = NULL;
47 		}
48 	}
49 
50 	return skb;
51 }
52 
53 static inline int should_drop_frame(struct sk_buff *skb,
54 				    int present_fcs_len)
55 {
56 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
57 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
58 
59 	if (status->flag & (RX_FLAG_FAILED_FCS_CRC | RX_FLAG_FAILED_PLCP_CRC))
60 		return 1;
61 	if (unlikely(skb->len < 16 + present_fcs_len))
62 		return 1;
63 	if (ieee80211_is_ctl(hdr->frame_control) &&
64 	    !ieee80211_is_pspoll(hdr->frame_control) &&
65 	    !ieee80211_is_back_req(hdr->frame_control))
66 		return 1;
67 	return 0;
68 }
69 
70 static int
71 ieee80211_rx_radiotap_len(struct ieee80211_local *local,
72 			  struct ieee80211_rx_status *status)
73 {
74 	int len;
75 
76 	/* always present fields */
77 	len = sizeof(struct ieee80211_radiotap_header) + 9;
78 
79 	if (status->flag & RX_FLAG_TSFT)
80 		len += 8;
81 	if (local->hw.flags & IEEE80211_HW_SIGNAL_DBM)
82 		len += 1;
83 	if (local->hw.flags & IEEE80211_HW_NOISE_DBM)
84 		len += 1;
85 
86 	if (len & 1) /* padding for RX_FLAGS if necessary */
87 		len++;
88 
89 	return len;
90 }
91 
92 /*
93  * ieee80211_add_rx_radiotap_header - add radiotap header
94  *
95  * add a radiotap header containing all the fields which the hardware provided.
96  */
97 static void
98 ieee80211_add_rx_radiotap_header(struct ieee80211_local *local,
99 				 struct sk_buff *skb,
100 				 struct ieee80211_rate *rate,
101 				 int rtap_len)
102 {
103 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
104 	struct ieee80211_radiotap_header *rthdr;
105 	unsigned char *pos;
106 	u16 rx_flags = 0;
107 
108 	rthdr = (struct ieee80211_radiotap_header *)skb_push(skb, rtap_len);
109 	memset(rthdr, 0, rtap_len);
110 
111 	/* radiotap header, set always present flags */
112 	rthdr->it_present =
113 		cpu_to_le32((1 << IEEE80211_RADIOTAP_FLAGS) |
114 			    (1 << IEEE80211_RADIOTAP_CHANNEL) |
115 			    (1 << IEEE80211_RADIOTAP_ANTENNA) |
116 			    (1 << IEEE80211_RADIOTAP_RX_FLAGS));
117 	rthdr->it_len = cpu_to_le16(rtap_len);
118 
119 	pos = (unsigned char *)(rthdr+1);
120 
121 	/* the order of the following fields is important */
122 
123 	/* IEEE80211_RADIOTAP_TSFT */
124 	if (status->flag & RX_FLAG_TSFT) {
125 		put_unaligned_le64(status->mactime, pos);
126 		rthdr->it_present |=
127 			cpu_to_le32(1 << IEEE80211_RADIOTAP_TSFT);
128 		pos += 8;
129 	}
130 
131 	/* IEEE80211_RADIOTAP_FLAGS */
132 	if (local->hw.flags & IEEE80211_HW_RX_INCLUDES_FCS)
133 		*pos |= IEEE80211_RADIOTAP_F_FCS;
134 	if (status->flag & (RX_FLAG_FAILED_FCS_CRC | RX_FLAG_FAILED_PLCP_CRC))
135 		*pos |= IEEE80211_RADIOTAP_F_BADFCS;
136 	if (status->flag & RX_FLAG_SHORTPRE)
137 		*pos |= IEEE80211_RADIOTAP_F_SHORTPRE;
138 	pos++;
139 
140 	/* IEEE80211_RADIOTAP_RATE */
141 	if (status->flag & RX_FLAG_HT) {
142 		/*
143 		 * TODO: add following information into radiotap header once
144 		 * suitable fields are defined for it:
145 		 * - MCS index (status->rate_idx)
146 		 * - HT40 (status->flag & RX_FLAG_40MHZ)
147 		 * - short-GI (status->flag & RX_FLAG_SHORT_GI)
148 		 */
149 		*pos = 0;
150 	} else {
151 		rthdr->it_present |= cpu_to_le32(1 << IEEE80211_RADIOTAP_RATE);
152 		*pos = rate->bitrate / 5;
153 	}
154 	pos++;
155 
156 	/* IEEE80211_RADIOTAP_CHANNEL */
157 	put_unaligned_le16(status->freq, pos);
158 	pos += 2;
159 	if (status->band == IEEE80211_BAND_5GHZ)
160 		put_unaligned_le16(IEEE80211_CHAN_OFDM | IEEE80211_CHAN_5GHZ,
161 				   pos);
162 	else if (status->flag & RX_FLAG_HT)
163 		put_unaligned_le16(IEEE80211_CHAN_DYN | IEEE80211_CHAN_2GHZ,
164 				   pos);
165 	else if (rate->flags & IEEE80211_RATE_ERP_G)
166 		put_unaligned_le16(IEEE80211_CHAN_OFDM | IEEE80211_CHAN_2GHZ,
167 				   pos);
168 	else
169 		put_unaligned_le16(IEEE80211_CHAN_CCK | IEEE80211_CHAN_2GHZ,
170 				   pos);
171 	pos += 2;
172 
173 	/* IEEE80211_RADIOTAP_DBM_ANTSIGNAL */
174 	if (local->hw.flags & IEEE80211_HW_SIGNAL_DBM) {
175 		*pos = status->signal;
176 		rthdr->it_present |=
177 			cpu_to_le32(1 << IEEE80211_RADIOTAP_DBM_ANTSIGNAL);
178 		pos++;
179 	}
180 
181 	/* IEEE80211_RADIOTAP_DBM_ANTNOISE */
182 	if (local->hw.flags & IEEE80211_HW_NOISE_DBM) {
183 		*pos = status->noise;
184 		rthdr->it_present |=
185 			cpu_to_le32(1 << IEEE80211_RADIOTAP_DBM_ANTNOISE);
186 		pos++;
187 	}
188 
189 	/* IEEE80211_RADIOTAP_LOCK_QUALITY is missing */
190 
191 	/* IEEE80211_RADIOTAP_ANTENNA */
192 	*pos = status->antenna;
193 	pos++;
194 
195 	/* IEEE80211_RADIOTAP_DB_ANTNOISE is not used */
196 
197 	/* IEEE80211_RADIOTAP_RX_FLAGS */
198 	/* ensure 2 byte alignment for the 2 byte field as required */
199 	if ((pos - (u8 *)rthdr) & 1)
200 		pos++;
201 	if (status->flag & RX_FLAG_FAILED_PLCP_CRC)
202 		rx_flags |= IEEE80211_RADIOTAP_F_RX_BADPLCP;
203 	put_unaligned_le16(rx_flags, pos);
204 	pos += 2;
205 }
206 
207 /*
208  * This function copies a received frame to all monitor interfaces and
209  * returns a cleaned-up SKB that no longer includes the FCS nor the
210  * radiotap header the driver might have added.
211  */
212 static struct sk_buff *
213 ieee80211_rx_monitor(struct ieee80211_local *local, struct sk_buff *origskb,
214 		     struct ieee80211_rate *rate)
215 {
216 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(origskb);
217 	struct ieee80211_sub_if_data *sdata;
218 	int needed_headroom = 0;
219 	struct sk_buff *skb, *skb2;
220 	struct net_device *prev_dev = NULL;
221 	int present_fcs_len = 0;
222 
223 	/*
224 	 * First, we may need to make a copy of the skb because
225 	 *  (1) we need to modify it for radiotap (if not present), and
226 	 *  (2) the other RX handlers will modify the skb we got.
227 	 *
228 	 * We don't need to, of course, if we aren't going to return
229 	 * the SKB because it has a bad FCS/PLCP checksum.
230 	 */
231 
232 	/* room for the radiotap header based on driver features */
233 	needed_headroom = ieee80211_rx_radiotap_len(local, status);
234 
235 	if (local->hw.flags & IEEE80211_HW_RX_INCLUDES_FCS)
236 		present_fcs_len = FCS_LEN;
237 
238 	if (!local->monitors) {
239 		if (should_drop_frame(origskb, present_fcs_len)) {
240 			dev_kfree_skb(origskb);
241 			return NULL;
242 		}
243 
244 		return remove_monitor_info(local, origskb);
245 	}
246 
247 	if (should_drop_frame(origskb, present_fcs_len)) {
248 		/* only need to expand headroom if necessary */
249 		skb = origskb;
250 		origskb = NULL;
251 
252 		/*
253 		 * This shouldn't trigger often because most devices have an
254 		 * RX header they pull before we get here, and that should
255 		 * be big enough for our radiotap information. We should
256 		 * probably export the length to drivers so that we can have
257 		 * them allocate enough headroom to start with.
258 		 */
259 		if (skb_headroom(skb) < needed_headroom &&
260 		    pskb_expand_head(skb, needed_headroom, 0, GFP_ATOMIC)) {
261 			dev_kfree_skb(skb);
262 			return NULL;
263 		}
264 	} else {
265 		/*
266 		 * Need to make a copy and possibly remove radiotap header
267 		 * and FCS from the original.
268 		 */
269 		skb = skb_copy_expand(origskb, needed_headroom, 0, GFP_ATOMIC);
270 
271 		origskb = remove_monitor_info(local, origskb);
272 
273 		if (!skb)
274 			return origskb;
275 	}
276 
277 	/* prepend radiotap information */
278 	ieee80211_add_rx_radiotap_header(local, skb, rate, needed_headroom);
279 
280 	skb_reset_mac_header(skb);
281 	skb->ip_summed = CHECKSUM_UNNECESSARY;
282 	skb->pkt_type = PACKET_OTHERHOST;
283 	skb->protocol = htons(ETH_P_802_2);
284 
285 	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
286 		if (!netif_running(sdata->dev))
287 			continue;
288 
289 		if (sdata->vif.type != NL80211_IFTYPE_MONITOR)
290 			continue;
291 
292 		if (sdata->u.mntr_flags & MONITOR_FLAG_COOK_FRAMES)
293 			continue;
294 
295 		if (prev_dev) {
296 			skb2 = skb_clone(skb, GFP_ATOMIC);
297 			if (skb2) {
298 				skb2->dev = prev_dev;
299 				netif_rx(skb2);
300 			}
301 		}
302 
303 		prev_dev = sdata->dev;
304 		sdata->dev->stats.rx_packets++;
305 		sdata->dev->stats.rx_bytes += skb->len;
306 	}
307 
308 	if (prev_dev) {
309 		skb->dev = prev_dev;
310 		netif_rx(skb);
311 	} else
312 		dev_kfree_skb(skb);
313 
314 	return origskb;
315 }
316 
317 
318 static void ieee80211_parse_qos(struct ieee80211_rx_data *rx)
319 {
320 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
321 	int tid;
322 
323 	/* does the frame have a qos control field? */
324 	if (ieee80211_is_data_qos(hdr->frame_control)) {
325 		u8 *qc = ieee80211_get_qos_ctl(hdr);
326 		/* frame has qos control */
327 		tid = *qc & IEEE80211_QOS_CTL_TID_MASK;
328 		if (*qc & IEEE80211_QOS_CONTROL_A_MSDU_PRESENT)
329 			rx->flags |= IEEE80211_RX_AMSDU;
330 		else
331 			rx->flags &= ~IEEE80211_RX_AMSDU;
332 	} else {
333 		/*
334 		 * IEEE 802.11-2007, 7.1.3.4.1 ("Sequence Number field"):
335 		 *
336 		 *	Sequence numbers for management frames, QoS data
337 		 *	frames with a broadcast/multicast address in the
338 		 *	Address 1 field, and all non-QoS data frames sent
339 		 *	by QoS STAs are assigned using an additional single
340 		 *	modulo-4096 counter, [...]
341 		 *
342 		 * We also use that counter for non-QoS STAs.
343 		 */
344 		tid = NUM_RX_DATA_QUEUES - 1;
345 	}
346 
347 	rx->queue = tid;
348 	/* Set skb->priority to 1d tag if highest order bit of TID is not set.
349 	 * For now, set skb->priority to 0 for other cases. */
350 	rx->skb->priority = (tid > 7) ? 0 : tid;
351 }
352 
353 /**
354  * DOC: Packet alignment
355  *
356  * Drivers always need to pass packets that are aligned to two-byte boundaries
357  * to the stack.
358  *
359  * Additionally, should, if possible, align the payload data in a way that
360  * guarantees that the contained IP header is aligned to a four-byte
361  * boundary. In the case of regular frames, this simply means aligning the
362  * payload to a four-byte boundary (because either the IP header is directly
363  * contained, or IV/RFC1042 headers that have a length divisible by four are
364  * in front of it).
365  *
366  * With A-MSDU frames, however, the payload data address must yield two modulo
367  * four because there are 14-byte 802.3 headers within the A-MSDU frames that
368  * push the IP header further back to a multiple of four again. Thankfully, the
369  * specs were sane enough this time around to require padding each A-MSDU
370  * subframe to a length that is a multiple of four.
371  *
372  * Padding like Atheros hardware adds which is inbetween the 802.11 header and
373  * the payload is not supported, the driver is required to move the 802.11
374  * header to be directly in front of the payload in that case.
375  */
376 static void ieee80211_verify_alignment(struct ieee80211_rx_data *rx)
377 {
378 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
379 	int hdrlen;
380 
381 #ifndef CONFIG_MAC80211_DEBUG_PACKET_ALIGNMENT
382 	return;
383 #endif
384 
385 	if (WARN_ONCE((unsigned long)rx->skb->data & 1,
386 		      "unaligned packet at 0x%p\n", rx->skb->data))
387 		return;
388 
389 	if (!ieee80211_is_data_present(hdr->frame_control))
390 		return;
391 
392 	hdrlen = ieee80211_hdrlen(hdr->frame_control);
393 	if (rx->flags & IEEE80211_RX_AMSDU)
394 		hdrlen += ETH_HLEN;
395 	WARN_ONCE(((unsigned long)(rx->skb->data + hdrlen)) & 3,
396 		  "unaligned IP payload at 0x%p\n", rx->skb->data + hdrlen);
397 }
398 
399 
400 /* rx handlers */
401 
402 static ieee80211_rx_result debug_noinline
403 ieee80211_rx_h_passive_scan(struct ieee80211_rx_data *rx)
404 {
405 	struct ieee80211_local *local = rx->local;
406 	struct sk_buff *skb = rx->skb;
407 
408 	if (unlikely(test_bit(SCAN_HW_SCANNING, &local->scanning)))
409 		return ieee80211_scan_rx(rx->sdata, skb);
410 
411 	if (unlikely(test_bit(SCAN_SW_SCANNING, &local->scanning) &&
412 		     (rx->flags & IEEE80211_RX_IN_SCAN))) {
413 		/* drop all the other packets during a software scan anyway */
414 		if (ieee80211_scan_rx(rx->sdata, skb) != RX_QUEUED)
415 			dev_kfree_skb(skb);
416 		return RX_QUEUED;
417 	}
418 
419 	if (unlikely(rx->flags & IEEE80211_RX_IN_SCAN)) {
420 		/* scanning finished during invoking of handlers */
421 		I802_DEBUG_INC(local->rx_handlers_drop_passive_scan);
422 		return RX_DROP_UNUSABLE;
423 	}
424 
425 	return RX_CONTINUE;
426 }
427 
428 
429 static int ieee80211_is_unicast_robust_mgmt_frame(struct sk_buff *skb)
430 {
431 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
432 
433 	if (skb->len < 24 || is_multicast_ether_addr(hdr->addr1))
434 		return 0;
435 
436 	return ieee80211_is_robust_mgmt_frame(hdr);
437 }
438 
439 
440 static int ieee80211_is_multicast_robust_mgmt_frame(struct sk_buff *skb)
441 {
442 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
443 
444 	if (skb->len < 24 || !is_multicast_ether_addr(hdr->addr1))
445 		return 0;
446 
447 	return ieee80211_is_robust_mgmt_frame(hdr);
448 }
449 
450 
451 /* Get the BIP key index from MMIE; return -1 if this is not a BIP frame */
452 static int ieee80211_get_mmie_keyidx(struct sk_buff *skb)
453 {
454 	struct ieee80211_mgmt *hdr = (struct ieee80211_mgmt *) skb->data;
455 	struct ieee80211_mmie *mmie;
456 
457 	if (skb->len < 24 + sizeof(*mmie) ||
458 	    !is_multicast_ether_addr(hdr->da))
459 		return -1;
460 
461 	if (!ieee80211_is_robust_mgmt_frame((struct ieee80211_hdr *) hdr))
462 		return -1; /* not a robust management frame */
463 
464 	mmie = (struct ieee80211_mmie *)
465 		(skb->data + skb->len - sizeof(*mmie));
466 	if (mmie->element_id != WLAN_EID_MMIE ||
467 	    mmie->length != sizeof(*mmie) - 2)
468 		return -1;
469 
470 	return le16_to_cpu(mmie->key_id);
471 }
472 
473 
474 static ieee80211_rx_result
475 ieee80211_rx_mesh_check(struct ieee80211_rx_data *rx)
476 {
477 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
478 	unsigned int hdrlen = ieee80211_hdrlen(hdr->frame_control);
479 	char *dev_addr = rx->sdata->dev->dev_addr;
480 
481 	if (ieee80211_is_data(hdr->frame_control)) {
482 		if (is_multicast_ether_addr(hdr->addr1)) {
483 			if (ieee80211_has_tods(hdr->frame_control) ||
484 				!ieee80211_has_fromds(hdr->frame_control))
485 				return RX_DROP_MONITOR;
486 			if (memcmp(hdr->addr3, dev_addr, ETH_ALEN) == 0)
487 				return RX_DROP_MONITOR;
488 		} else {
489 			if (!ieee80211_has_a4(hdr->frame_control))
490 				return RX_DROP_MONITOR;
491 			if (memcmp(hdr->addr4, dev_addr, ETH_ALEN) == 0)
492 				return RX_DROP_MONITOR;
493 		}
494 	}
495 
496 	/* If there is not an established peer link and this is not a peer link
497 	 * establisment frame, beacon or probe, drop the frame.
498 	 */
499 
500 	if (!rx->sta || sta_plink_state(rx->sta) != PLINK_ESTAB) {
501 		struct ieee80211_mgmt *mgmt;
502 
503 		if (!ieee80211_is_mgmt(hdr->frame_control))
504 			return RX_DROP_MONITOR;
505 
506 		if (ieee80211_is_action(hdr->frame_control)) {
507 			mgmt = (struct ieee80211_mgmt *)hdr;
508 			if (mgmt->u.action.category != MESH_PLINK_CATEGORY)
509 				return RX_DROP_MONITOR;
510 			return RX_CONTINUE;
511 		}
512 
513 		if (ieee80211_is_probe_req(hdr->frame_control) ||
514 		    ieee80211_is_probe_resp(hdr->frame_control) ||
515 		    ieee80211_is_beacon(hdr->frame_control))
516 			return RX_CONTINUE;
517 
518 		return RX_DROP_MONITOR;
519 
520 	}
521 
522 #define msh_h_get(h, l) ((struct ieee80211s_hdr *) ((u8 *)h + l))
523 
524 	if (ieee80211_is_data(hdr->frame_control) &&
525 	    is_multicast_ether_addr(hdr->addr1) &&
526 	    mesh_rmc_check(hdr->addr3, msh_h_get(hdr, hdrlen), rx->sdata))
527 		return RX_DROP_MONITOR;
528 #undef msh_h_get
529 
530 	return RX_CONTINUE;
531 }
532 
533 #define SEQ_MODULO 0x1000
534 #define SEQ_MASK   0xfff
535 
536 static inline int seq_less(u16 sq1, u16 sq2)
537 {
538 	return ((sq1 - sq2) & SEQ_MASK) > (SEQ_MODULO >> 1);
539 }
540 
541 static inline u16 seq_inc(u16 sq)
542 {
543 	return (sq + 1) & SEQ_MASK;
544 }
545 
546 static inline u16 seq_sub(u16 sq1, u16 sq2)
547 {
548 	return (sq1 - sq2) & SEQ_MASK;
549 }
550 
551 
552 static void ieee80211_release_reorder_frame(struct ieee80211_hw *hw,
553 					    struct tid_ampdu_rx *tid_agg_rx,
554 					    int index,
555 					    struct sk_buff_head *frames)
556 {
557 	struct ieee80211_supported_band *sband;
558 	struct ieee80211_rate *rate = NULL;
559 	struct sk_buff *skb = tid_agg_rx->reorder_buf[index];
560 	struct ieee80211_rx_status *status;
561 
562 	if (!skb)
563 		goto no_frame;
564 
565 	status = IEEE80211_SKB_RXCB(skb);
566 
567 	/* release the reordered frames to stack */
568 	sband = hw->wiphy->bands[status->band];
569 	if (!(status->flag & RX_FLAG_HT))
570 		rate = &sband->bitrates[status->rate_idx];
571 	tid_agg_rx->stored_mpdu_num--;
572 	tid_agg_rx->reorder_buf[index] = NULL;
573 	__skb_queue_tail(frames, skb);
574 
575 no_frame:
576 	tid_agg_rx->head_seq_num = seq_inc(tid_agg_rx->head_seq_num);
577 }
578 
579 static void ieee80211_release_reorder_frames(struct ieee80211_hw *hw,
580 					     struct tid_ampdu_rx *tid_agg_rx,
581 					     u16 head_seq_num,
582 					     struct sk_buff_head *frames)
583 {
584 	int index;
585 
586 	while (seq_less(tid_agg_rx->head_seq_num, head_seq_num)) {
587 		index = seq_sub(tid_agg_rx->head_seq_num, tid_agg_rx->ssn) %
588 							tid_agg_rx->buf_size;
589 		ieee80211_release_reorder_frame(hw, tid_agg_rx, index, frames);
590 	}
591 }
592 
593 /*
594  * Timeout (in jiffies) for skb's that are waiting in the RX reorder buffer. If
595  * the skb was added to the buffer longer than this time ago, the earlier
596  * frames that have not yet been received are assumed to be lost and the skb
597  * can be released for processing. This may also release other skb's from the
598  * reorder buffer if there are no additional gaps between the frames.
599  */
600 #define HT_RX_REORDER_BUF_TIMEOUT (HZ / 10)
601 
602 /*
603  * As this function belongs to the RX path it must be under
604  * rcu_read_lock protection. It returns false if the frame
605  * can be processed immediately, true if it was consumed.
606  */
607 static bool ieee80211_sta_manage_reorder_buf(struct ieee80211_hw *hw,
608 					     struct tid_ampdu_rx *tid_agg_rx,
609 					     struct sk_buff *skb,
610 					     struct sk_buff_head *frames)
611 {
612 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
613 	u16 sc = le16_to_cpu(hdr->seq_ctrl);
614 	u16 mpdu_seq_num = (sc & IEEE80211_SCTL_SEQ) >> 4;
615 	u16 head_seq_num, buf_size;
616 	int index;
617 
618 	buf_size = tid_agg_rx->buf_size;
619 	head_seq_num = tid_agg_rx->head_seq_num;
620 
621 	/* frame with out of date sequence number */
622 	if (seq_less(mpdu_seq_num, head_seq_num)) {
623 		dev_kfree_skb(skb);
624 		return true;
625 	}
626 
627 	/*
628 	 * If frame the sequence number exceeds our buffering window
629 	 * size release some previous frames to make room for this one.
630 	 */
631 	if (!seq_less(mpdu_seq_num, head_seq_num + buf_size)) {
632 		head_seq_num = seq_inc(seq_sub(mpdu_seq_num, buf_size));
633 		/* release stored frames up to new head to stack */
634 		ieee80211_release_reorder_frames(hw, tid_agg_rx, head_seq_num,
635 						 frames);
636 	}
637 
638 	/* Now the new frame is always in the range of the reordering buffer */
639 
640 	index = seq_sub(mpdu_seq_num, tid_agg_rx->ssn) % tid_agg_rx->buf_size;
641 
642 	/* check if we already stored this frame */
643 	if (tid_agg_rx->reorder_buf[index]) {
644 		dev_kfree_skb(skb);
645 		return true;
646 	}
647 
648 	/*
649 	 * If the current MPDU is in the right order and nothing else
650 	 * is stored we can process it directly, no need to buffer it.
651 	 */
652 	if (mpdu_seq_num == tid_agg_rx->head_seq_num &&
653 	    tid_agg_rx->stored_mpdu_num == 0) {
654 		tid_agg_rx->head_seq_num = seq_inc(tid_agg_rx->head_seq_num);
655 		return false;
656 	}
657 
658 	/* put the frame in the reordering buffer */
659 	tid_agg_rx->reorder_buf[index] = skb;
660 	tid_agg_rx->reorder_time[index] = jiffies;
661 	tid_agg_rx->stored_mpdu_num++;
662 	/* release the buffer until next missing frame */
663 	index = seq_sub(tid_agg_rx->head_seq_num, tid_agg_rx->ssn) %
664 						tid_agg_rx->buf_size;
665 	if (!tid_agg_rx->reorder_buf[index] &&
666 	    tid_agg_rx->stored_mpdu_num > 1) {
667 		/*
668 		 * No buffers ready to be released, but check whether any
669 		 * frames in the reorder buffer have timed out.
670 		 */
671 		int j;
672 		int skipped = 1;
673 		for (j = (index + 1) % tid_agg_rx->buf_size; j != index;
674 		     j = (j + 1) % tid_agg_rx->buf_size) {
675 			if (!tid_agg_rx->reorder_buf[j]) {
676 				skipped++;
677 				continue;
678 			}
679 			if (!time_after(jiffies, tid_agg_rx->reorder_time[j] +
680 					HT_RX_REORDER_BUF_TIMEOUT))
681 				break;
682 
683 #ifdef CONFIG_MAC80211_HT_DEBUG
684 			if (net_ratelimit())
685 				printk(KERN_DEBUG "%s: release an RX reorder "
686 				       "frame due to timeout on earlier "
687 				       "frames\n",
688 				       wiphy_name(hw->wiphy));
689 #endif
690 			ieee80211_release_reorder_frame(hw, tid_agg_rx,
691 							j, frames);
692 
693 			/*
694 			 * Increment the head seq# also for the skipped slots.
695 			 */
696 			tid_agg_rx->head_seq_num =
697 				(tid_agg_rx->head_seq_num + skipped) & SEQ_MASK;
698 			skipped = 0;
699 		}
700 	} else while (tid_agg_rx->reorder_buf[index]) {
701 		ieee80211_release_reorder_frame(hw, tid_agg_rx, index, frames);
702 		index =	seq_sub(tid_agg_rx->head_seq_num, tid_agg_rx->ssn) %
703 							tid_agg_rx->buf_size;
704 	}
705 
706 	return true;
707 }
708 
709 /*
710  * Reorder MPDUs from A-MPDUs, keeping them on a buffer. Returns
711  * true if the MPDU was buffered, false if it should be processed.
712  */
713 static void ieee80211_rx_reorder_ampdu(struct ieee80211_rx_data *rx,
714 				       struct sk_buff_head *frames)
715 {
716 	struct sk_buff *skb = rx->skb;
717 	struct ieee80211_local *local = rx->local;
718 	struct ieee80211_hw *hw = &local->hw;
719 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
720 	struct sta_info *sta = rx->sta;
721 	struct tid_ampdu_rx *tid_agg_rx;
722 	u16 sc;
723 	int tid;
724 
725 	if (!ieee80211_is_data_qos(hdr->frame_control))
726 		goto dont_reorder;
727 
728 	/*
729 	 * filter the QoS data rx stream according to
730 	 * STA/TID and check if this STA/TID is on aggregation
731 	 */
732 
733 	if (!sta)
734 		goto dont_reorder;
735 
736 	tid = *ieee80211_get_qos_ctl(hdr) & IEEE80211_QOS_CTL_TID_MASK;
737 
738 	if (sta->ampdu_mlme.tid_state_rx[tid] != HT_AGG_STATE_OPERATIONAL)
739 		goto dont_reorder;
740 
741 	tid_agg_rx = sta->ampdu_mlme.tid_rx[tid];
742 
743 	/* qos null data frames are excluded */
744 	if (unlikely(hdr->frame_control & cpu_to_le16(IEEE80211_STYPE_NULLFUNC)))
745 		goto dont_reorder;
746 
747 	/* new, potentially un-ordered, ampdu frame - process it */
748 
749 	/* reset session timer */
750 	if (tid_agg_rx->timeout)
751 		mod_timer(&tid_agg_rx->session_timer,
752 			  TU_TO_EXP_TIME(tid_agg_rx->timeout));
753 
754 	/* if this mpdu is fragmented - terminate rx aggregation session */
755 	sc = le16_to_cpu(hdr->seq_ctrl);
756 	if (sc & IEEE80211_SCTL_FRAG) {
757 		ieee80211_sta_stop_rx_ba_session(sta->sdata, sta->sta.addr,
758 			tid, 0, WLAN_REASON_QSTA_REQUIRE_SETUP);
759 		dev_kfree_skb(skb);
760 		return;
761 	}
762 
763 	if (ieee80211_sta_manage_reorder_buf(hw, tid_agg_rx, skb, frames))
764 		return;
765 
766  dont_reorder:
767 	__skb_queue_tail(frames, skb);
768 }
769 
770 static ieee80211_rx_result debug_noinline
771 ieee80211_rx_h_check(struct ieee80211_rx_data *rx)
772 {
773 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
774 
775 	/* Drop duplicate 802.11 retransmissions (IEEE 802.11 Chap. 9.2.9) */
776 	if (rx->sta && !is_multicast_ether_addr(hdr->addr1)) {
777 		if (unlikely(ieee80211_has_retry(hdr->frame_control) &&
778 			     rx->sta->last_seq_ctrl[rx->queue] ==
779 			     hdr->seq_ctrl)) {
780 			if (rx->flags & IEEE80211_RX_RA_MATCH) {
781 				rx->local->dot11FrameDuplicateCount++;
782 				rx->sta->num_duplicates++;
783 			}
784 			return RX_DROP_MONITOR;
785 		} else
786 			rx->sta->last_seq_ctrl[rx->queue] = hdr->seq_ctrl;
787 	}
788 
789 	if (unlikely(rx->skb->len < 16)) {
790 		I802_DEBUG_INC(rx->local->rx_handlers_drop_short);
791 		return RX_DROP_MONITOR;
792 	}
793 
794 	/* Drop disallowed frame classes based on STA auth/assoc state;
795 	 * IEEE 802.11, Chap 5.5.
796 	 *
797 	 * mac80211 filters only based on association state, i.e. it drops
798 	 * Class 3 frames from not associated stations. hostapd sends
799 	 * deauth/disassoc frames when needed. In addition, hostapd is
800 	 * responsible for filtering on both auth and assoc states.
801 	 */
802 
803 	if (ieee80211_vif_is_mesh(&rx->sdata->vif))
804 		return ieee80211_rx_mesh_check(rx);
805 
806 	if (unlikely((ieee80211_is_data(hdr->frame_control) ||
807 		      ieee80211_is_pspoll(hdr->frame_control)) &&
808 		     rx->sdata->vif.type != NL80211_IFTYPE_ADHOC &&
809 		     (!rx->sta || !test_sta_flags(rx->sta, WLAN_STA_ASSOC)))) {
810 		if ((!ieee80211_has_fromds(hdr->frame_control) &&
811 		     !ieee80211_has_tods(hdr->frame_control) &&
812 		     ieee80211_is_data(hdr->frame_control)) ||
813 		    !(rx->flags & IEEE80211_RX_RA_MATCH)) {
814 			/* Drop IBSS frames and frames for other hosts
815 			 * silently. */
816 			return RX_DROP_MONITOR;
817 		}
818 
819 		return RX_DROP_MONITOR;
820 	}
821 
822 	return RX_CONTINUE;
823 }
824 
825 
826 static ieee80211_rx_result debug_noinline
827 ieee80211_rx_h_decrypt(struct ieee80211_rx_data *rx)
828 {
829 	struct sk_buff *skb = rx->skb;
830 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
831 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
832 	int keyidx;
833 	int hdrlen;
834 	ieee80211_rx_result result = RX_DROP_UNUSABLE;
835 	struct ieee80211_key *stakey = NULL;
836 	int mmie_keyidx = -1;
837 
838 	/*
839 	 * Key selection 101
840 	 *
841 	 * There are four types of keys:
842 	 *  - GTK (group keys)
843 	 *  - IGTK (group keys for management frames)
844 	 *  - PTK (pairwise keys)
845 	 *  - STK (station-to-station pairwise keys)
846 	 *
847 	 * When selecting a key, we have to distinguish between multicast
848 	 * (including broadcast) and unicast frames, the latter can only
849 	 * use PTKs and STKs while the former always use GTKs and IGTKs.
850 	 * Unless, of course, actual WEP keys ("pre-RSNA") are used, then
851 	 * unicast frames can also use key indices like GTKs. Hence, if we
852 	 * don't have a PTK/STK we check the key index for a WEP key.
853 	 *
854 	 * Note that in a regular BSS, multicast frames are sent by the
855 	 * AP only, associated stations unicast the frame to the AP first
856 	 * which then multicasts it on their behalf.
857 	 *
858 	 * There is also a slight problem in IBSS mode: GTKs are negotiated
859 	 * with each station, that is something we don't currently handle.
860 	 * The spec seems to expect that one negotiates the same key with
861 	 * every station but there's no such requirement; VLANs could be
862 	 * possible.
863 	 */
864 
865 	/*
866 	 * No point in finding a key and decrypting if the frame is neither
867 	 * addressed to us nor a multicast frame.
868 	 */
869 	if (!(rx->flags & IEEE80211_RX_RA_MATCH))
870 		return RX_CONTINUE;
871 
872 	/* start without a key */
873 	rx->key = NULL;
874 
875 	if (rx->sta)
876 		stakey = rcu_dereference(rx->sta->key);
877 
878 	if (!ieee80211_has_protected(hdr->frame_control))
879 		mmie_keyidx = ieee80211_get_mmie_keyidx(rx->skb);
880 
881 	if (!is_multicast_ether_addr(hdr->addr1) && stakey) {
882 		rx->key = stakey;
883 		/* Skip decryption if the frame is not protected. */
884 		if (!ieee80211_has_protected(hdr->frame_control))
885 			return RX_CONTINUE;
886 	} else if (mmie_keyidx >= 0) {
887 		/* Broadcast/multicast robust management frame / BIP */
888 		if ((status->flag & RX_FLAG_DECRYPTED) &&
889 		    (status->flag & RX_FLAG_IV_STRIPPED))
890 			return RX_CONTINUE;
891 
892 		if (mmie_keyidx < NUM_DEFAULT_KEYS ||
893 		    mmie_keyidx >= NUM_DEFAULT_KEYS + NUM_DEFAULT_MGMT_KEYS)
894 			return RX_DROP_MONITOR; /* unexpected BIP keyidx */
895 		rx->key = rcu_dereference(rx->sdata->keys[mmie_keyidx]);
896 	} else if (!ieee80211_has_protected(hdr->frame_control)) {
897 		/*
898 		 * The frame was not protected, so skip decryption. However, we
899 		 * need to set rx->key if there is a key that could have been
900 		 * used so that the frame may be dropped if encryption would
901 		 * have been expected.
902 		 */
903 		struct ieee80211_key *key = NULL;
904 		if (ieee80211_is_mgmt(hdr->frame_control) &&
905 		    is_multicast_ether_addr(hdr->addr1) &&
906 		    (key = rcu_dereference(rx->sdata->default_mgmt_key)))
907 			rx->key = key;
908 		else if ((key = rcu_dereference(rx->sdata->default_key)))
909 			rx->key = key;
910 		return RX_CONTINUE;
911 	} else {
912 		/*
913 		 * The device doesn't give us the IV so we won't be
914 		 * able to look up the key. That's ok though, we
915 		 * don't need to decrypt the frame, we just won't
916 		 * be able to keep statistics accurate.
917 		 * Except for key threshold notifications, should
918 		 * we somehow allow the driver to tell us which key
919 		 * the hardware used if this flag is set?
920 		 */
921 		if ((status->flag & RX_FLAG_DECRYPTED) &&
922 		    (status->flag & RX_FLAG_IV_STRIPPED))
923 			return RX_CONTINUE;
924 
925 		hdrlen = ieee80211_hdrlen(hdr->frame_control);
926 
927 		if (rx->skb->len < 8 + hdrlen)
928 			return RX_DROP_UNUSABLE; /* TODO: count this? */
929 
930 		/*
931 		 * no need to call ieee80211_wep_get_keyidx,
932 		 * it verifies a bunch of things we've done already
933 		 */
934 		keyidx = rx->skb->data[hdrlen + 3] >> 6;
935 
936 		rx->key = rcu_dereference(rx->sdata->keys[keyidx]);
937 
938 		/*
939 		 * RSNA-protected unicast frames should always be sent with
940 		 * pairwise or station-to-station keys, but for WEP we allow
941 		 * using a key index as well.
942 		 */
943 		if (rx->key && rx->key->conf.alg != ALG_WEP &&
944 		    !is_multicast_ether_addr(hdr->addr1))
945 			rx->key = NULL;
946 	}
947 
948 	if (rx->key) {
949 		rx->key->tx_rx_count++;
950 		/* TODO: add threshold stuff again */
951 	} else {
952 		return RX_DROP_MONITOR;
953 	}
954 
955 	/* Check for weak IVs if possible */
956 	if (rx->sta && rx->key->conf.alg == ALG_WEP &&
957 	    ieee80211_is_data(hdr->frame_control) &&
958 	    (!(status->flag & RX_FLAG_IV_STRIPPED) ||
959 	     !(status->flag & RX_FLAG_DECRYPTED)) &&
960 	    ieee80211_wep_is_weak_iv(rx->skb, rx->key))
961 		rx->sta->wep_weak_iv_count++;
962 
963 	switch (rx->key->conf.alg) {
964 	case ALG_WEP:
965 		result = ieee80211_crypto_wep_decrypt(rx);
966 		break;
967 	case ALG_TKIP:
968 		result = ieee80211_crypto_tkip_decrypt(rx);
969 		break;
970 	case ALG_CCMP:
971 		result = ieee80211_crypto_ccmp_decrypt(rx);
972 		break;
973 	case ALG_AES_CMAC:
974 		result = ieee80211_crypto_aes_cmac_decrypt(rx);
975 		break;
976 	}
977 
978 	/* either the frame has been decrypted or will be dropped */
979 	status->flag |= RX_FLAG_DECRYPTED;
980 
981 	return result;
982 }
983 
984 static ieee80211_rx_result debug_noinline
985 ieee80211_rx_h_check_more_data(struct ieee80211_rx_data *rx)
986 {
987 	struct ieee80211_local *local;
988 	struct ieee80211_hdr *hdr;
989 	struct sk_buff *skb;
990 
991 	local = rx->local;
992 	skb = rx->skb;
993 	hdr = (struct ieee80211_hdr *) skb->data;
994 
995 	if (!local->pspolling)
996 		return RX_CONTINUE;
997 
998 	if (!ieee80211_has_fromds(hdr->frame_control))
999 		/* this is not from AP */
1000 		return RX_CONTINUE;
1001 
1002 	if (!ieee80211_is_data(hdr->frame_control))
1003 		return RX_CONTINUE;
1004 
1005 	if (!ieee80211_has_moredata(hdr->frame_control)) {
1006 		/* AP has no more frames buffered for us */
1007 		local->pspolling = false;
1008 		return RX_CONTINUE;
1009 	}
1010 
1011 	/* more data bit is set, let's request a new frame from the AP */
1012 	ieee80211_send_pspoll(local, rx->sdata);
1013 
1014 	return RX_CONTINUE;
1015 }
1016 
1017 static void ap_sta_ps_start(struct sta_info *sta)
1018 {
1019 	struct ieee80211_sub_if_data *sdata = sta->sdata;
1020 	struct ieee80211_local *local = sdata->local;
1021 
1022 	atomic_inc(&sdata->bss->num_sta_ps);
1023 	set_sta_flags(sta, WLAN_STA_PS_STA);
1024 	drv_sta_notify(local, &sdata->vif, STA_NOTIFY_SLEEP, &sta->sta);
1025 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
1026 	printk(KERN_DEBUG "%s: STA %pM aid %d enters power save mode\n",
1027 	       sdata->dev->name, sta->sta.addr, sta->sta.aid);
1028 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
1029 }
1030 
1031 static void ap_sta_ps_end(struct sta_info *sta)
1032 {
1033 	struct ieee80211_sub_if_data *sdata = sta->sdata;
1034 
1035 	atomic_dec(&sdata->bss->num_sta_ps);
1036 
1037 	clear_sta_flags(sta, WLAN_STA_PS_STA);
1038 
1039 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
1040 	printk(KERN_DEBUG "%s: STA %pM aid %d exits power save mode\n",
1041 	       sdata->dev->name, sta->sta.addr, sta->sta.aid);
1042 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
1043 
1044 	if (test_sta_flags(sta, WLAN_STA_PS_DRIVER)) {
1045 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
1046 		printk(KERN_DEBUG "%s: STA %pM aid %d driver-ps-blocked\n",
1047 		       sdata->dev->name, sta->sta.addr, sta->sta.aid);
1048 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
1049 		return;
1050 	}
1051 
1052 	ieee80211_sta_ps_deliver_wakeup(sta);
1053 }
1054 
1055 static ieee80211_rx_result debug_noinline
1056 ieee80211_rx_h_sta_process(struct ieee80211_rx_data *rx)
1057 {
1058 	struct sta_info *sta = rx->sta;
1059 	struct sk_buff *skb = rx->skb;
1060 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
1061 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
1062 
1063 	if (!sta)
1064 		return RX_CONTINUE;
1065 
1066 	/*
1067 	 * Update last_rx only for IBSS packets which are for the current
1068 	 * BSSID to avoid keeping the current IBSS network alive in cases
1069 	 * where other STAs start using different BSSID.
1070 	 */
1071 	if (rx->sdata->vif.type == NL80211_IFTYPE_ADHOC) {
1072 		u8 *bssid = ieee80211_get_bssid(hdr, rx->skb->len,
1073 						NL80211_IFTYPE_ADHOC);
1074 		if (compare_ether_addr(bssid, rx->sdata->u.ibss.bssid) == 0)
1075 			sta->last_rx = jiffies;
1076 	} else if (!is_multicast_ether_addr(hdr->addr1)) {
1077 		/*
1078 		 * Mesh beacons will update last_rx when if they are found to
1079 		 * match the current local configuration when processed.
1080 		 */
1081 		sta->last_rx = jiffies;
1082 	}
1083 
1084 	if (!(rx->flags & IEEE80211_RX_RA_MATCH))
1085 		return RX_CONTINUE;
1086 
1087 	if (rx->sdata->vif.type == NL80211_IFTYPE_STATION)
1088 		ieee80211_sta_rx_notify(rx->sdata, hdr);
1089 
1090 	sta->rx_fragments++;
1091 	sta->rx_bytes += rx->skb->len;
1092 	sta->last_signal = status->signal;
1093 	sta->last_noise = status->noise;
1094 
1095 	/*
1096 	 * Change STA power saving mode only at the end of a frame
1097 	 * exchange sequence.
1098 	 */
1099 	if (!ieee80211_has_morefrags(hdr->frame_control) &&
1100 	    (rx->sdata->vif.type == NL80211_IFTYPE_AP ||
1101 	     rx->sdata->vif.type == NL80211_IFTYPE_AP_VLAN)) {
1102 		if (test_sta_flags(sta, WLAN_STA_PS_STA)) {
1103 			/*
1104 			 * Ignore doze->wake transitions that are
1105 			 * indicated by non-data frames, the standard
1106 			 * is unclear here, but for example going to
1107 			 * PS mode and then scanning would cause a
1108 			 * doze->wake transition for the probe request,
1109 			 * and that is clearly undesirable.
1110 			 */
1111 			if (ieee80211_is_data(hdr->frame_control) &&
1112 			    !ieee80211_has_pm(hdr->frame_control))
1113 				ap_sta_ps_end(sta);
1114 		} else {
1115 			if (ieee80211_has_pm(hdr->frame_control))
1116 				ap_sta_ps_start(sta);
1117 		}
1118 	}
1119 
1120 	/*
1121 	 * Drop (qos-)data::nullfunc frames silently, since they
1122 	 * are used only to control station power saving mode.
1123 	 */
1124 	if (ieee80211_is_nullfunc(hdr->frame_control) ||
1125 	    ieee80211_is_qos_nullfunc(hdr->frame_control)) {
1126 		I802_DEBUG_INC(rx->local->rx_handlers_drop_nullfunc);
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->dev->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 	if (rx->sta && test_sta_flags(rx->sta, WLAN_STA_MFP)) {
1402 		if (unlikely(ieee80211_is_unicast_robust_mgmt_frame(rx->skb) &&
1403 			     rx->key))
1404 			return -EACCES;
1405 		/* BIP does not use Protected field, so need to check MMIE */
1406 		if (unlikely(ieee80211_is_multicast_robust_mgmt_frame(rx->skb) &&
1407 			     ieee80211_get_mmie_keyidx(rx->skb) < 0 &&
1408 			     rx->key))
1409 			return -EACCES;
1410 		/*
1411 		 * When using MFP, Action frames are not allowed prior to
1412 		 * having configured keys.
1413 		 */
1414 		if (unlikely(ieee80211_is_action(fc) && !rx->key &&
1415 			     ieee80211_is_robust_mgmt_frame(
1416 				     (struct ieee80211_hdr *) rx->skb->data)))
1417 			return -EACCES;
1418 	}
1419 
1420 	return 0;
1421 }
1422 
1423 static int
1424 __ieee80211_data_to_8023(struct ieee80211_rx_data *rx)
1425 {
1426 	struct ieee80211_sub_if_data *sdata = rx->sdata;
1427 	struct net_device *dev = sdata->dev;
1428 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
1429 
1430 	if (ieee80211_has_a4(hdr->frame_control) &&
1431 	    sdata->vif.type == NL80211_IFTYPE_AP_VLAN && !sdata->u.vlan.sta)
1432 		return -1;
1433 
1434 	if (is_multicast_ether_addr(hdr->addr1) &&
1435 	    ((sdata->vif.type == NL80211_IFTYPE_AP_VLAN && sdata->u.vlan.sta) ||
1436 	     (sdata->vif.type == NL80211_IFTYPE_STATION && sdata->u.mgd.use_4addr)))
1437 		return -1;
1438 
1439 	return ieee80211_data_to_8023(rx->skb, dev->dev_addr, sdata->vif.type);
1440 }
1441 
1442 /*
1443  * requires that rx->skb is a frame with ethernet header
1444  */
1445 static bool ieee80211_frame_allowed(struct ieee80211_rx_data *rx, __le16 fc)
1446 {
1447 	static const u8 pae_group_addr[ETH_ALEN] __aligned(2)
1448 		= { 0x01, 0x80, 0xC2, 0x00, 0x00, 0x03 };
1449 	struct ethhdr *ehdr = (struct ethhdr *) rx->skb->data;
1450 
1451 	/*
1452 	 * Allow EAPOL frames to us/the PAE group address regardless
1453 	 * of whether the frame was encrypted or not.
1454 	 */
1455 	if (ehdr->h_proto == htons(ETH_P_PAE) &&
1456 	    (compare_ether_addr(ehdr->h_dest, rx->sdata->dev->dev_addr) == 0 ||
1457 	     compare_ether_addr(ehdr->h_dest, pae_group_addr) == 0))
1458 		return true;
1459 
1460 	if (ieee80211_802_1x_port_control(rx) ||
1461 	    ieee80211_drop_unencrypted(rx, fc))
1462 		return false;
1463 
1464 	return true;
1465 }
1466 
1467 /*
1468  * requires that rx->skb is a frame with ethernet header
1469  */
1470 static void
1471 ieee80211_deliver_skb(struct ieee80211_rx_data *rx)
1472 {
1473 	struct ieee80211_sub_if_data *sdata = rx->sdata;
1474 	struct net_device *dev = sdata->dev;
1475 	struct ieee80211_local *local = rx->local;
1476 	struct sk_buff *skb, *xmit_skb;
1477 	struct ethhdr *ehdr = (struct ethhdr *) rx->skb->data;
1478 	struct sta_info *dsta;
1479 
1480 	skb = rx->skb;
1481 	xmit_skb = NULL;
1482 
1483 	if ((sdata->vif.type == NL80211_IFTYPE_AP ||
1484 	     sdata->vif.type == NL80211_IFTYPE_AP_VLAN) &&
1485 	    !(sdata->flags & IEEE80211_SDATA_DONT_BRIDGE_PACKETS) &&
1486 	    (rx->flags & IEEE80211_RX_RA_MATCH) &&
1487 	    (sdata->vif.type != NL80211_IFTYPE_AP_VLAN || !sdata->u.vlan.sta)) {
1488 		if (is_multicast_ether_addr(ehdr->h_dest)) {
1489 			/*
1490 			 * send multicast frames both to higher layers in
1491 			 * local net stack and back to the wireless medium
1492 			 */
1493 			xmit_skb = skb_copy(skb, GFP_ATOMIC);
1494 			if (!xmit_skb && net_ratelimit())
1495 				printk(KERN_DEBUG "%s: failed to clone "
1496 				       "multicast frame\n", dev->name);
1497 		} else {
1498 			dsta = sta_info_get(local, skb->data);
1499 			if (dsta && dsta->sdata->dev == dev) {
1500 				/*
1501 				 * The destination station is associated to
1502 				 * this AP (in this VLAN), so send the frame
1503 				 * directly to it and do not pass it to local
1504 				 * net stack.
1505 				 */
1506 				xmit_skb = skb;
1507 				skb = NULL;
1508 			}
1509 		}
1510 	}
1511 
1512 	if (skb) {
1513 		int align __maybe_unused;
1514 
1515 #if defined(CONFIG_MAC80211_DEBUG_PACKET_ALIGNMENT) || !defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS)
1516 		/*
1517 		 * 'align' will only take the values 0 or 2 here
1518 		 * since all frames are required to be aligned
1519 		 * to 2-byte boundaries when being passed to
1520 		 * mac80211. That also explains the __skb_push()
1521 		 * below.
1522 		 */
1523 		align = ((unsigned long)(skb->data + sizeof(struct ethhdr))) & 3;
1524 		if (align) {
1525 			if (WARN_ON(skb_headroom(skb) < 3)) {
1526 				dev_kfree_skb(skb);
1527 				skb = NULL;
1528 			} else {
1529 				u8 *data = skb->data;
1530 				size_t len = skb_headlen(skb);
1531 				skb->data -= align;
1532 				memmove(skb->data, data, len);
1533 				skb_set_tail_pointer(skb, len);
1534 			}
1535 		}
1536 #endif
1537 
1538 		if (skb) {
1539 			/* deliver to local stack */
1540 			skb->protocol = eth_type_trans(skb, dev);
1541 			memset(skb->cb, 0, sizeof(skb->cb));
1542 			netif_rx(skb);
1543 		}
1544 	}
1545 
1546 	if (xmit_skb) {
1547 		/* send to wireless media */
1548 		xmit_skb->protocol = htons(ETH_P_802_3);
1549 		skb_reset_network_header(xmit_skb);
1550 		skb_reset_mac_header(xmit_skb);
1551 		dev_queue_xmit(xmit_skb);
1552 	}
1553 }
1554 
1555 static ieee80211_rx_result debug_noinline
1556 ieee80211_rx_h_amsdu(struct ieee80211_rx_data *rx)
1557 {
1558 	struct net_device *dev = rx->sdata->dev;
1559 	struct ieee80211_local *local = rx->local;
1560 	u16 ethertype;
1561 	u8 *payload;
1562 	struct sk_buff *skb = rx->skb, *frame = NULL;
1563 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
1564 	__le16 fc = hdr->frame_control;
1565 	const struct ethhdr *eth;
1566 	int remaining, err;
1567 	u8 dst[ETH_ALEN];
1568 	u8 src[ETH_ALEN];
1569 
1570 	if (unlikely(!ieee80211_is_data(fc)))
1571 		return RX_CONTINUE;
1572 
1573 	if (unlikely(!ieee80211_is_data_present(fc)))
1574 		return RX_DROP_MONITOR;
1575 
1576 	if (!(rx->flags & IEEE80211_RX_AMSDU))
1577 		return RX_CONTINUE;
1578 
1579 	err = __ieee80211_data_to_8023(rx);
1580 	if (unlikely(err))
1581 		return RX_DROP_UNUSABLE;
1582 
1583 	skb->dev = dev;
1584 
1585 	dev->stats.rx_packets++;
1586 	dev->stats.rx_bytes += skb->len;
1587 
1588 	/* skip the wrapping header */
1589 	eth = (struct ethhdr *) skb_pull(skb, sizeof(struct ethhdr));
1590 	if (!eth)
1591 		return RX_DROP_UNUSABLE;
1592 
1593 	while (skb != frame) {
1594 		u8 padding;
1595 		__be16 len = eth->h_proto;
1596 		unsigned int subframe_len = sizeof(struct ethhdr) + ntohs(len);
1597 
1598 		remaining = skb->len;
1599 		memcpy(dst, eth->h_dest, ETH_ALEN);
1600 		memcpy(src, eth->h_source, ETH_ALEN);
1601 
1602 		padding = ((4 - subframe_len) & 0x3);
1603 		/* the last MSDU has no padding */
1604 		if (subframe_len > remaining)
1605 			return RX_DROP_UNUSABLE;
1606 
1607 		skb_pull(skb, sizeof(struct ethhdr));
1608 		/* if last subframe reuse skb */
1609 		if (remaining <= subframe_len + padding)
1610 			frame = skb;
1611 		else {
1612 			/*
1613 			 * Allocate and reserve two bytes more for payload
1614 			 * alignment since sizeof(struct ethhdr) is 14.
1615 			 */
1616 			frame = dev_alloc_skb(
1617 				ALIGN(local->hw.extra_tx_headroom, 4) +
1618 				subframe_len + 2);
1619 
1620 			if (frame == NULL)
1621 				return RX_DROP_UNUSABLE;
1622 
1623 			skb_reserve(frame,
1624 				    ALIGN(local->hw.extra_tx_headroom, 4) +
1625 				    sizeof(struct ethhdr) + 2);
1626 			memcpy(skb_put(frame, ntohs(len)), skb->data,
1627 				ntohs(len));
1628 
1629 			eth = (struct ethhdr *) skb_pull(skb, ntohs(len) +
1630 							padding);
1631 			if (!eth) {
1632 				dev_kfree_skb(frame);
1633 				return RX_DROP_UNUSABLE;
1634 			}
1635 		}
1636 
1637 		skb_reset_network_header(frame);
1638 		frame->dev = dev;
1639 		frame->priority = skb->priority;
1640 		rx->skb = frame;
1641 
1642 		payload = frame->data;
1643 		ethertype = (payload[6] << 8) | payload[7];
1644 
1645 		if (likely((compare_ether_addr(payload, rfc1042_header) == 0 &&
1646 			    ethertype != ETH_P_AARP && ethertype != ETH_P_IPX) ||
1647 			   compare_ether_addr(payload,
1648 					      bridge_tunnel_header) == 0)) {
1649 			/* remove RFC1042 or Bridge-Tunnel
1650 			 * encapsulation and replace EtherType */
1651 			skb_pull(frame, 6);
1652 			memcpy(skb_push(frame, ETH_ALEN), src, ETH_ALEN);
1653 			memcpy(skb_push(frame, ETH_ALEN), dst, ETH_ALEN);
1654 		} else {
1655 			memcpy(skb_push(frame, sizeof(__be16)),
1656 			       &len, sizeof(__be16));
1657 			memcpy(skb_push(frame, ETH_ALEN), src, ETH_ALEN);
1658 			memcpy(skb_push(frame, ETH_ALEN), dst, ETH_ALEN);
1659 		}
1660 
1661 		if (!ieee80211_frame_allowed(rx, fc)) {
1662 			if (skb == frame) /* last frame */
1663 				return RX_DROP_UNUSABLE;
1664 			dev_kfree_skb(frame);
1665 			continue;
1666 		}
1667 
1668 		ieee80211_deliver_skb(rx);
1669 	}
1670 
1671 	return RX_QUEUED;
1672 }
1673 
1674 #ifdef CONFIG_MAC80211_MESH
1675 static ieee80211_rx_result
1676 ieee80211_rx_h_mesh_fwding(struct ieee80211_rx_data *rx)
1677 {
1678 	struct ieee80211_hdr *hdr;
1679 	struct ieee80211s_hdr *mesh_hdr;
1680 	unsigned int hdrlen;
1681 	struct sk_buff *skb = rx->skb, *fwd_skb;
1682 	struct ieee80211_local *local = rx->local;
1683 	struct ieee80211_sub_if_data *sdata = rx->sdata;
1684 
1685 	hdr = (struct ieee80211_hdr *) skb->data;
1686 	hdrlen = ieee80211_hdrlen(hdr->frame_control);
1687 	mesh_hdr = (struct ieee80211s_hdr *) (skb->data + hdrlen);
1688 
1689 	if (!ieee80211_is_data(hdr->frame_control))
1690 		return RX_CONTINUE;
1691 
1692 	if (!mesh_hdr->ttl)
1693 		/* illegal frame */
1694 		return RX_DROP_MONITOR;
1695 
1696 	if (mesh_hdr->flags & MESH_FLAGS_AE) {
1697 		struct mesh_path *mppath;
1698 		char *proxied_addr;
1699 		char *mpp_addr;
1700 
1701 		if (is_multicast_ether_addr(hdr->addr1)) {
1702 			mpp_addr = hdr->addr3;
1703 			proxied_addr = mesh_hdr->eaddr1;
1704 		} else {
1705 			mpp_addr = hdr->addr4;
1706 			proxied_addr = mesh_hdr->eaddr2;
1707 		}
1708 
1709 		rcu_read_lock();
1710 		mppath = mpp_path_lookup(proxied_addr, sdata);
1711 		if (!mppath) {
1712 			mpp_path_add(proxied_addr, mpp_addr, sdata);
1713 		} else {
1714 			spin_lock_bh(&mppath->state_lock);
1715 			if (compare_ether_addr(mppath->mpp, mpp_addr) != 0)
1716 				memcpy(mppath->mpp, mpp_addr, ETH_ALEN);
1717 			spin_unlock_bh(&mppath->state_lock);
1718 		}
1719 		rcu_read_unlock();
1720 	}
1721 
1722 	/* Frame has reached destination.  Don't forward */
1723 	if (!is_multicast_ether_addr(hdr->addr1) &&
1724 	    compare_ether_addr(sdata->dev->dev_addr, hdr->addr3) == 0)
1725 		return RX_CONTINUE;
1726 
1727 	mesh_hdr->ttl--;
1728 
1729 	if (rx->flags & IEEE80211_RX_RA_MATCH) {
1730 		if (!mesh_hdr->ttl)
1731 			IEEE80211_IFSTA_MESH_CTR_INC(&rx->sdata->u.mesh,
1732 						     dropped_frames_ttl);
1733 		else {
1734 			struct ieee80211_hdr *fwd_hdr;
1735 			struct ieee80211_tx_info *info;
1736 
1737 			fwd_skb = skb_copy(skb, GFP_ATOMIC);
1738 
1739 			if (!fwd_skb && net_ratelimit())
1740 				printk(KERN_DEBUG "%s: failed to clone mesh frame\n",
1741 						   sdata->dev->name);
1742 
1743 			fwd_hdr =  (struct ieee80211_hdr *) fwd_skb->data;
1744 			memcpy(fwd_hdr->addr2, sdata->dev->dev_addr, ETH_ALEN);
1745 			info = IEEE80211_SKB_CB(fwd_skb);
1746 			memset(info, 0, sizeof(*info));
1747 			info->flags |= IEEE80211_TX_INTFL_NEED_TXPROCESSING;
1748 			info->control.vif = &rx->sdata->vif;
1749 			skb_set_queue_mapping(skb,
1750 				ieee80211_select_queue(rx->sdata, fwd_skb));
1751 			ieee80211_set_qos_hdr(local, skb);
1752 			if (is_multicast_ether_addr(fwd_hdr->addr1))
1753 				IEEE80211_IFSTA_MESH_CTR_INC(&sdata->u.mesh,
1754 								fwded_mcast);
1755 			else {
1756 				int err;
1757 				/*
1758 				 * Save TA to addr1 to send TA a path error if a
1759 				 * suitable next hop is not found
1760 				 */
1761 				memcpy(fwd_hdr->addr1, fwd_hdr->addr2,
1762 						ETH_ALEN);
1763 				err = mesh_nexthop_lookup(fwd_skb, sdata);
1764 				/* Failed to immediately resolve next hop:
1765 				 * fwded frame was dropped or will be added
1766 				 * later to the pending skb queue.  */
1767 				if (err)
1768 					return RX_DROP_MONITOR;
1769 
1770 				IEEE80211_IFSTA_MESH_CTR_INC(&sdata->u.mesh,
1771 								fwded_unicast);
1772 			}
1773 			IEEE80211_IFSTA_MESH_CTR_INC(&sdata->u.mesh,
1774 						     fwded_frames);
1775 			ieee80211_add_pending_skb(local, fwd_skb);
1776 		}
1777 	}
1778 
1779 	if (is_multicast_ether_addr(hdr->addr1) ||
1780 	    sdata->dev->flags & IFF_PROMISC)
1781 		return RX_CONTINUE;
1782 	else
1783 		return RX_DROP_MONITOR;
1784 }
1785 #endif
1786 
1787 static ieee80211_rx_result debug_noinline
1788 ieee80211_rx_h_data(struct ieee80211_rx_data *rx)
1789 {
1790 	struct ieee80211_sub_if_data *sdata = rx->sdata;
1791 	struct net_device *dev = sdata->dev;
1792 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
1793 	__le16 fc = hdr->frame_control;
1794 	int err;
1795 
1796 	if (unlikely(!ieee80211_is_data(hdr->frame_control)))
1797 		return RX_CONTINUE;
1798 
1799 	if (unlikely(!ieee80211_is_data_present(hdr->frame_control)))
1800 		return RX_DROP_MONITOR;
1801 
1802 	/*
1803 	 * Allow the cooked monitor interface of an AP to see 4-addr frames so
1804 	 * that a 4-addr station can be detected and moved into a separate VLAN
1805 	 */
1806 	if (ieee80211_has_a4(hdr->frame_control) &&
1807 	    sdata->vif.type == NL80211_IFTYPE_AP)
1808 		return RX_DROP_MONITOR;
1809 
1810 	err = __ieee80211_data_to_8023(rx);
1811 	if (unlikely(err))
1812 		return RX_DROP_UNUSABLE;
1813 
1814 	if (!ieee80211_frame_allowed(rx, fc))
1815 		return RX_DROP_MONITOR;
1816 
1817 	rx->skb->dev = dev;
1818 
1819 	dev->stats.rx_packets++;
1820 	dev->stats.rx_bytes += rx->skb->len;
1821 
1822 	ieee80211_deliver_skb(rx);
1823 
1824 	return RX_QUEUED;
1825 }
1826 
1827 static ieee80211_rx_result debug_noinline
1828 ieee80211_rx_h_ctrl(struct ieee80211_rx_data *rx, struct sk_buff_head *frames)
1829 {
1830 	struct ieee80211_local *local = rx->local;
1831 	struct ieee80211_hw *hw = &local->hw;
1832 	struct sk_buff *skb = rx->skb;
1833 	struct ieee80211_bar *bar = (struct ieee80211_bar *)skb->data;
1834 	struct tid_ampdu_rx *tid_agg_rx;
1835 	u16 start_seq_num;
1836 	u16 tid;
1837 
1838 	if (likely(!ieee80211_is_ctl(bar->frame_control)))
1839 		return RX_CONTINUE;
1840 
1841 	if (ieee80211_is_back_req(bar->frame_control)) {
1842 		if (!rx->sta)
1843 			return RX_DROP_MONITOR;
1844 		tid = le16_to_cpu(bar->control) >> 12;
1845 		if (rx->sta->ampdu_mlme.tid_state_rx[tid]
1846 					!= HT_AGG_STATE_OPERATIONAL)
1847 			return RX_DROP_MONITOR;
1848 		tid_agg_rx = rx->sta->ampdu_mlme.tid_rx[tid];
1849 
1850 		start_seq_num = le16_to_cpu(bar->start_seq_num) >> 4;
1851 
1852 		/* reset session timer */
1853 		if (tid_agg_rx->timeout)
1854 			mod_timer(&tid_agg_rx->session_timer,
1855 				  TU_TO_EXP_TIME(tid_agg_rx->timeout));
1856 
1857 		/* release stored frames up to start of BAR */
1858 		ieee80211_release_reorder_frames(hw, tid_agg_rx, start_seq_num,
1859 						 frames);
1860 		kfree_skb(skb);
1861 		return RX_QUEUED;
1862 	}
1863 
1864 	return RX_CONTINUE;
1865 }
1866 
1867 static void ieee80211_process_sa_query_req(struct ieee80211_sub_if_data *sdata,
1868 					   struct ieee80211_mgmt *mgmt,
1869 					   size_t len)
1870 {
1871 	struct ieee80211_local *local = sdata->local;
1872 	struct sk_buff *skb;
1873 	struct ieee80211_mgmt *resp;
1874 
1875 	if (compare_ether_addr(mgmt->da, sdata->dev->dev_addr) != 0) {
1876 		/* Not to own unicast address */
1877 		return;
1878 	}
1879 
1880 	if (compare_ether_addr(mgmt->sa, sdata->u.mgd.bssid) != 0 ||
1881 	    compare_ether_addr(mgmt->bssid, sdata->u.mgd.bssid) != 0) {
1882 		/* Not from the current AP or not associated yet. */
1883 		return;
1884 	}
1885 
1886 	if (len < 24 + 1 + sizeof(resp->u.action.u.sa_query)) {
1887 		/* Too short SA Query request frame */
1888 		return;
1889 	}
1890 
1891 	skb = dev_alloc_skb(sizeof(*resp) + local->hw.extra_tx_headroom);
1892 	if (skb == NULL)
1893 		return;
1894 
1895 	skb_reserve(skb, local->hw.extra_tx_headroom);
1896 	resp = (struct ieee80211_mgmt *) skb_put(skb, 24);
1897 	memset(resp, 0, 24);
1898 	memcpy(resp->da, mgmt->sa, ETH_ALEN);
1899 	memcpy(resp->sa, sdata->dev->dev_addr, ETH_ALEN);
1900 	memcpy(resp->bssid, sdata->u.mgd.bssid, ETH_ALEN);
1901 	resp->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
1902 					  IEEE80211_STYPE_ACTION);
1903 	skb_put(skb, 1 + sizeof(resp->u.action.u.sa_query));
1904 	resp->u.action.category = WLAN_CATEGORY_SA_QUERY;
1905 	resp->u.action.u.sa_query.action = WLAN_ACTION_SA_QUERY_RESPONSE;
1906 	memcpy(resp->u.action.u.sa_query.trans_id,
1907 	       mgmt->u.action.u.sa_query.trans_id,
1908 	       WLAN_SA_QUERY_TR_ID_LEN);
1909 
1910 	ieee80211_tx_skb(sdata, skb);
1911 }
1912 
1913 static ieee80211_rx_result debug_noinline
1914 ieee80211_rx_h_action(struct ieee80211_rx_data *rx)
1915 {
1916 	struct ieee80211_local *local = rx->local;
1917 	struct ieee80211_sub_if_data *sdata = rx->sdata;
1918 	struct ieee80211_mgmt *mgmt = (struct ieee80211_mgmt *) rx->skb->data;
1919 	int len = rx->skb->len;
1920 
1921 	if (!ieee80211_is_action(mgmt->frame_control))
1922 		return RX_CONTINUE;
1923 
1924 	if (!rx->sta)
1925 		return RX_DROP_MONITOR;
1926 
1927 	if (!(rx->flags & IEEE80211_RX_RA_MATCH))
1928 		return RX_DROP_MONITOR;
1929 
1930 	if (ieee80211_drop_unencrypted(rx, mgmt->frame_control))
1931 		return RX_DROP_MONITOR;
1932 
1933 	/* all categories we currently handle have action_code */
1934 	if (len < IEEE80211_MIN_ACTION_SIZE + 1)
1935 		return RX_DROP_MONITOR;
1936 
1937 	switch (mgmt->u.action.category) {
1938 	case WLAN_CATEGORY_BACK:
1939 		/*
1940 		 * The aggregation code is not prepared to handle
1941 		 * anything but STA/AP due to the BSSID handling;
1942 		 * IBSS could work in the code but isn't supported
1943 		 * by drivers or the standard.
1944 		 */
1945 		if (sdata->vif.type != NL80211_IFTYPE_STATION &&
1946 		    sdata->vif.type != NL80211_IFTYPE_AP_VLAN &&
1947 		    sdata->vif.type != NL80211_IFTYPE_AP)
1948 			return RX_DROP_MONITOR;
1949 
1950 		switch (mgmt->u.action.u.addba_req.action_code) {
1951 		case WLAN_ACTION_ADDBA_REQ:
1952 			if (len < (IEEE80211_MIN_ACTION_SIZE +
1953 				   sizeof(mgmt->u.action.u.addba_req)))
1954 				return RX_DROP_MONITOR;
1955 			ieee80211_process_addba_request(local, rx->sta, mgmt, len);
1956 			break;
1957 		case WLAN_ACTION_ADDBA_RESP:
1958 			if (len < (IEEE80211_MIN_ACTION_SIZE +
1959 				   sizeof(mgmt->u.action.u.addba_resp)))
1960 				return RX_DROP_MONITOR;
1961 			ieee80211_process_addba_resp(local, rx->sta, mgmt, len);
1962 			break;
1963 		case WLAN_ACTION_DELBA:
1964 			if (len < (IEEE80211_MIN_ACTION_SIZE +
1965 				   sizeof(mgmt->u.action.u.delba)))
1966 				return RX_DROP_MONITOR;
1967 			ieee80211_process_delba(sdata, rx->sta, mgmt, len);
1968 			break;
1969 		}
1970 		break;
1971 	case WLAN_CATEGORY_SPECTRUM_MGMT:
1972 		if (local->hw.conf.channel->band != IEEE80211_BAND_5GHZ)
1973 			return RX_DROP_MONITOR;
1974 
1975 		if (sdata->vif.type != NL80211_IFTYPE_STATION)
1976 			return RX_DROP_MONITOR;
1977 
1978 		switch (mgmt->u.action.u.measurement.action_code) {
1979 		case WLAN_ACTION_SPCT_MSR_REQ:
1980 			if (len < (IEEE80211_MIN_ACTION_SIZE +
1981 				   sizeof(mgmt->u.action.u.measurement)))
1982 				return RX_DROP_MONITOR;
1983 			ieee80211_process_measurement_req(sdata, mgmt, len);
1984 			break;
1985 		case WLAN_ACTION_SPCT_CHL_SWITCH:
1986 			if (len < (IEEE80211_MIN_ACTION_SIZE +
1987 				   sizeof(mgmt->u.action.u.chan_switch)))
1988 				return RX_DROP_MONITOR;
1989 
1990 			if (sdata->vif.type != NL80211_IFTYPE_STATION)
1991 				return RX_DROP_MONITOR;
1992 
1993 			if (memcmp(mgmt->bssid, sdata->u.mgd.bssid, ETH_ALEN))
1994 				return RX_DROP_MONITOR;
1995 
1996 			return ieee80211_sta_rx_mgmt(sdata, rx->skb);
1997 		}
1998 		break;
1999 	case WLAN_CATEGORY_SA_QUERY:
2000 		if (len < (IEEE80211_MIN_ACTION_SIZE +
2001 			   sizeof(mgmt->u.action.u.sa_query)))
2002 			return RX_DROP_MONITOR;
2003 		switch (mgmt->u.action.u.sa_query.action) {
2004 		case WLAN_ACTION_SA_QUERY_REQUEST:
2005 			if (sdata->vif.type != NL80211_IFTYPE_STATION)
2006 				return RX_DROP_MONITOR;
2007 			ieee80211_process_sa_query_req(sdata, mgmt, len);
2008 			break;
2009 		case WLAN_ACTION_SA_QUERY_RESPONSE:
2010 			/*
2011 			 * SA Query response is currently only used in AP mode
2012 			 * and it is processed in user space.
2013 			 */
2014 			return RX_CONTINUE;
2015 		}
2016 		break;
2017 	default:
2018 		/* do not process rejected action frames */
2019 		if (mgmt->u.action.category & 0x80)
2020 			return RX_DROP_MONITOR;
2021 
2022 		return RX_CONTINUE;
2023 	}
2024 
2025 	rx->sta->rx_packets++;
2026 	dev_kfree_skb(rx->skb);
2027 	return RX_QUEUED;
2028 }
2029 
2030 static ieee80211_rx_result debug_noinline
2031 ieee80211_rx_h_mgmt(struct ieee80211_rx_data *rx)
2032 {
2033 	struct ieee80211_sub_if_data *sdata = rx->sdata;
2034 	struct ieee80211_mgmt *mgmt = (struct ieee80211_mgmt *) rx->skb->data;
2035 
2036 	if (!(rx->flags & IEEE80211_RX_RA_MATCH))
2037 		return RX_DROP_MONITOR;
2038 
2039 	if (ieee80211_drop_unencrypted(rx, mgmt->frame_control))
2040 		return RX_DROP_MONITOR;
2041 
2042 	if (ieee80211_vif_is_mesh(&sdata->vif))
2043 		return ieee80211_mesh_rx_mgmt(sdata, rx->skb);
2044 
2045 	if (sdata->vif.type == NL80211_IFTYPE_ADHOC)
2046 		return ieee80211_ibss_rx_mgmt(sdata, rx->skb);
2047 
2048 	if (sdata->vif.type == NL80211_IFTYPE_STATION)
2049 		return ieee80211_sta_rx_mgmt(sdata, rx->skb);
2050 
2051 	return RX_DROP_MONITOR;
2052 }
2053 
2054 static void ieee80211_rx_michael_mic_report(struct ieee80211_hdr *hdr,
2055 					    struct ieee80211_rx_data *rx)
2056 {
2057 	int keyidx;
2058 	unsigned int hdrlen;
2059 
2060 	hdrlen = ieee80211_hdrlen(hdr->frame_control);
2061 	if (rx->skb->len >= hdrlen + 4)
2062 		keyidx = rx->skb->data[hdrlen + 3] >> 6;
2063 	else
2064 		keyidx = -1;
2065 
2066 	if (!rx->sta) {
2067 		/*
2068 		 * Some hardware seem to generate incorrect Michael MIC
2069 		 * reports; ignore them to avoid triggering countermeasures.
2070 		 */
2071 		return;
2072 	}
2073 
2074 	if (!ieee80211_has_protected(hdr->frame_control))
2075 		return;
2076 
2077 	if (rx->sdata->vif.type == NL80211_IFTYPE_AP && keyidx) {
2078 		/*
2079 		 * APs with pairwise keys should never receive Michael MIC
2080 		 * errors for non-zero keyidx because these are reserved for
2081 		 * group keys and only the AP is sending real multicast
2082 		 * frames in the BSS.
2083 		 */
2084 		return;
2085 	}
2086 
2087 	if (!ieee80211_is_data(hdr->frame_control) &&
2088 	    !ieee80211_is_auth(hdr->frame_control))
2089 		return;
2090 
2091 	mac80211_ev_michael_mic_failure(rx->sdata, keyidx, hdr, NULL,
2092 					GFP_ATOMIC);
2093 }
2094 
2095 /* TODO: use IEEE80211_RX_FRAGMENTED */
2096 static void ieee80211_rx_cooked_monitor(struct ieee80211_rx_data *rx,
2097 					struct ieee80211_rate *rate)
2098 {
2099 	struct ieee80211_sub_if_data *sdata;
2100 	struct ieee80211_local *local = rx->local;
2101 	struct ieee80211_rtap_hdr {
2102 		struct ieee80211_radiotap_header hdr;
2103 		u8 flags;
2104 		u8 rate_or_pad;
2105 		__le16 chan_freq;
2106 		__le16 chan_flags;
2107 	} __attribute__ ((packed)) *rthdr;
2108 	struct sk_buff *skb = rx->skb, *skb2;
2109 	struct net_device *prev_dev = NULL;
2110 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
2111 
2112 	if (status->flag & RX_FLAG_INTERNAL_CMTR)
2113 		goto out_free_skb;
2114 
2115 	if (skb_headroom(skb) < sizeof(*rthdr) &&
2116 	    pskb_expand_head(skb, sizeof(*rthdr), 0, GFP_ATOMIC))
2117 		goto out_free_skb;
2118 
2119 	rthdr = (void *)skb_push(skb, sizeof(*rthdr));
2120 	memset(rthdr, 0, sizeof(*rthdr));
2121 	rthdr->hdr.it_len = cpu_to_le16(sizeof(*rthdr));
2122 	rthdr->hdr.it_present =
2123 		cpu_to_le32((1 << IEEE80211_RADIOTAP_FLAGS) |
2124 			    (1 << IEEE80211_RADIOTAP_CHANNEL));
2125 
2126 	if (rate) {
2127 		rthdr->rate_or_pad = rate->bitrate / 5;
2128 		rthdr->hdr.it_present |=
2129 			cpu_to_le32(1 << IEEE80211_RADIOTAP_RATE);
2130 	}
2131 	rthdr->chan_freq = cpu_to_le16(status->freq);
2132 
2133 	if (status->band == IEEE80211_BAND_5GHZ)
2134 		rthdr->chan_flags = cpu_to_le16(IEEE80211_CHAN_OFDM |
2135 						IEEE80211_CHAN_5GHZ);
2136 	else
2137 		rthdr->chan_flags = cpu_to_le16(IEEE80211_CHAN_DYN |
2138 						IEEE80211_CHAN_2GHZ);
2139 
2140 	skb_set_mac_header(skb, 0);
2141 	skb->ip_summed = CHECKSUM_UNNECESSARY;
2142 	skb->pkt_type = PACKET_OTHERHOST;
2143 	skb->protocol = htons(ETH_P_802_2);
2144 
2145 	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
2146 		if (!netif_running(sdata->dev))
2147 			continue;
2148 
2149 		if (sdata->vif.type != NL80211_IFTYPE_MONITOR ||
2150 		    !(sdata->u.mntr_flags & MONITOR_FLAG_COOK_FRAMES))
2151 			continue;
2152 
2153 		if (prev_dev) {
2154 			skb2 = skb_clone(skb, GFP_ATOMIC);
2155 			if (skb2) {
2156 				skb2->dev = prev_dev;
2157 				netif_rx(skb2);
2158 			}
2159 		}
2160 
2161 		prev_dev = sdata->dev;
2162 		sdata->dev->stats.rx_packets++;
2163 		sdata->dev->stats.rx_bytes += skb->len;
2164 	}
2165 
2166 	if (prev_dev) {
2167 		skb->dev = prev_dev;
2168 		netif_rx(skb);
2169 		skb = NULL;
2170 	} else
2171 		goto out_free_skb;
2172 
2173 	status->flag |= RX_FLAG_INTERNAL_CMTR;
2174 	return;
2175 
2176  out_free_skb:
2177 	dev_kfree_skb(skb);
2178 }
2179 
2180 
2181 static void ieee80211_invoke_rx_handlers(struct ieee80211_sub_if_data *sdata,
2182 					 struct ieee80211_rx_data *rx,
2183 					 struct sk_buff *skb,
2184 					 struct ieee80211_rate *rate)
2185 {
2186 	struct sk_buff_head reorder_release;
2187 	ieee80211_rx_result res = RX_DROP_MONITOR;
2188 
2189 	__skb_queue_head_init(&reorder_release);
2190 
2191 	rx->skb = skb;
2192 	rx->sdata = sdata;
2193 
2194 #define CALL_RXH(rxh)			\
2195 	do {				\
2196 		res = rxh(rx);		\
2197 		if (res != RX_CONTINUE)	\
2198 			goto rxh_next;  \
2199 	} while (0);
2200 
2201 	/*
2202 	 * NB: the rxh_next label works even if we jump
2203 	 *     to it from here because then the list will
2204 	 *     be empty, which is a trivial check
2205 	 */
2206 	CALL_RXH(ieee80211_rx_h_passive_scan)
2207 	CALL_RXH(ieee80211_rx_h_check)
2208 
2209 	ieee80211_rx_reorder_ampdu(rx, &reorder_release);
2210 
2211 	while ((skb = __skb_dequeue(&reorder_release))) {
2212 		/*
2213 		 * all the other fields are valid across frames
2214 		 * that belong to an aMPDU since they are on the
2215 		 * same TID from the same station
2216 		 */
2217 		rx->skb = skb;
2218 
2219 		CALL_RXH(ieee80211_rx_h_decrypt)
2220 		CALL_RXH(ieee80211_rx_h_check_more_data)
2221 		CALL_RXH(ieee80211_rx_h_sta_process)
2222 		CALL_RXH(ieee80211_rx_h_defragment)
2223 		CALL_RXH(ieee80211_rx_h_ps_poll)
2224 		CALL_RXH(ieee80211_rx_h_michael_mic_verify)
2225 		/* must be after MMIC verify so header is counted in MPDU mic */
2226 		CALL_RXH(ieee80211_rx_h_remove_qos_control)
2227 		CALL_RXH(ieee80211_rx_h_amsdu)
2228 #ifdef CONFIG_MAC80211_MESH
2229 		if (ieee80211_vif_is_mesh(&sdata->vif))
2230 			CALL_RXH(ieee80211_rx_h_mesh_fwding);
2231 #endif
2232 		CALL_RXH(ieee80211_rx_h_data)
2233 
2234 		/* special treatment -- needs the queue */
2235 		res = ieee80211_rx_h_ctrl(rx, &reorder_release);
2236 		if (res != RX_CONTINUE)
2237 			goto rxh_next;
2238 
2239 		CALL_RXH(ieee80211_rx_h_action)
2240 		CALL_RXH(ieee80211_rx_h_mgmt)
2241 
2242 #undef CALL_RXH
2243 
2244  rxh_next:
2245 		switch (res) {
2246 		case RX_DROP_MONITOR:
2247 			I802_DEBUG_INC(sdata->local->rx_handlers_drop);
2248 			if (rx->sta)
2249 				rx->sta->rx_dropped++;
2250 			/* fall through */
2251 		case RX_CONTINUE:
2252 			ieee80211_rx_cooked_monitor(rx, rate);
2253 			break;
2254 		case RX_DROP_UNUSABLE:
2255 			I802_DEBUG_INC(sdata->local->rx_handlers_drop);
2256 			if (rx->sta)
2257 				rx->sta->rx_dropped++;
2258 			dev_kfree_skb(rx->skb);
2259 			break;
2260 		case RX_QUEUED:
2261 			I802_DEBUG_INC(sdata->local->rx_handlers_queued);
2262 			break;
2263 		}
2264 	}
2265 }
2266 
2267 /* main receive path */
2268 
2269 static int prepare_for_handlers(struct ieee80211_sub_if_data *sdata,
2270 				struct ieee80211_rx_data *rx,
2271 				struct ieee80211_hdr *hdr)
2272 {
2273 	struct sk_buff *skb = rx->skb;
2274 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
2275 	u8 *bssid = ieee80211_get_bssid(hdr, skb->len, sdata->vif.type);
2276 	int multicast = is_multicast_ether_addr(hdr->addr1);
2277 
2278 	switch (sdata->vif.type) {
2279 	case NL80211_IFTYPE_STATION:
2280 		if (!bssid && !sdata->u.mgd.use_4addr)
2281 			return 0;
2282 		if (!multicast &&
2283 		    compare_ether_addr(sdata->dev->dev_addr, hdr->addr1) != 0) {
2284 			if (!(sdata->dev->flags & IFF_PROMISC))
2285 				return 0;
2286 			rx->flags &= ~IEEE80211_RX_RA_MATCH;
2287 		}
2288 		break;
2289 	case NL80211_IFTYPE_ADHOC:
2290 		if (!bssid)
2291 			return 0;
2292 		if (ieee80211_is_beacon(hdr->frame_control)) {
2293 			return 1;
2294 		}
2295 		else if (!ieee80211_bssid_match(bssid, sdata->u.ibss.bssid)) {
2296 			if (!(rx->flags & IEEE80211_RX_IN_SCAN))
2297 				return 0;
2298 			rx->flags &= ~IEEE80211_RX_RA_MATCH;
2299 		} else if (!multicast &&
2300 			   compare_ether_addr(sdata->dev->dev_addr,
2301 					      hdr->addr1) != 0) {
2302 			if (!(sdata->dev->flags & IFF_PROMISC))
2303 				return 0;
2304 			rx->flags &= ~IEEE80211_RX_RA_MATCH;
2305 		} else if (!rx->sta) {
2306 			int rate_idx;
2307 			if (status->flag & RX_FLAG_HT)
2308 				rate_idx = 0; /* TODO: HT rates */
2309 			else
2310 				rate_idx = status->rate_idx;
2311 			rx->sta = ieee80211_ibss_add_sta(sdata, bssid, hdr->addr2,
2312 				BIT(rate_idx));
2313 		}
2314 		break;
2315 	case NL80211_IFTYPE_MESH_POINT:
2316 		if (!multicast &&
2317 		    compare_ether_addr(sdata->dev->dev_addr,
2318 				       hdr->addr1) != 0) {
2319 			if (!(sdata->dev->flags & IFF_PROMISC))
2320 				return 0;
2321 
2322 			rx->flags &= ~IEEE80211_RX_RA_MATCH;
2323 		}
2324 		break;
2325 	case NL80211_IFTYPE_AP_VLAN:
2326 	case NL80211_IFTYPE_AP:
2327 		if (!bssid) {
2328 			if (compare_ether_addr(sdata->dev->dev_addr,
2329 					       hdr->addr1))
2330 				return 0;
2331 		} else if (!ieee80211_bssid_match(bssid,
2332 					sdata->dev->dev_addr)) {
2333 			if (!(rx->flags & IEEE80211_RX_IN_SCAN))
2334 				return 0;
2335 			rx->flags &= ~IEEE80211_RX_RA_MATCH;
2336 		}
2337 		break;
2338 	case NL80211_IFTYPE_WDS:
2339 		if (bssid || !ieee80211_is_data(hdr->frame_control))
2340 			return 0;
2341 		if (compare_ether_addr(sdata->u.wds.remote_addr, hdr->addr2))
2342 			return 0;
2343 		break;
2344 	case NL80211_IFTYPE_MONITOR:
2345 	case NL80211_IFTYPE_UNSPECIFIED:
2346 	case __NL80211_IFTYPE_AFTER_LAST:
2347 		/* should never get here */
2348 		WARN_ON(1);
2349 		break;
2350 	}
2351 
2352 	return 1;
2353 }
2354 
2355 /*
2356  * This is the actual Rx frames handler. as it blongs to Rx path it must
2357  * be called with rcu_read_lock protection.
2358  */
2359 static void __ieee80211_rx_handle_packet(struct ieee80211_hw *hw,
2360 					 struct sk_buff *skb,
2361 					 struct ieee80211_rate *rate)
2362 {
2363 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
2364 	struct ieee80211_local *local = hw_to_local(hw);
2365 	struct ieee80211_sub_if_data *sdata;
2366 	struct ieee80211_hdr *hdr;
2367 	struct ieee80211_rx_data rx;
2368 	int prepares;
2369 	struct ieee80211_sub_if_data *prev = NULL;
2370 	struct sk_buff *skb_new;
2371 
2372 	hdr = (struct ieee80211_hdr *)skb->data;
2373 	memset(&rx, 0, sizeof(rx));
2374 	rx.skb = skb;
2375 	rx.local = local;
2376 
2377 	if (ieee80211_is_data(hdr->frame_control) || ieee80211_is_mgmt(hdr->frame_control))
2378 		local->dot11ReceivedFragmentCount++;
2379 
2380 	if (unlikely(test_bit(SCAN_HW_SCANNING, &local->scanning) ||
2381 		     test_bit(SCAN_OFF_CHANNEL, &local->scanning)))
2382 		rx.flags |= IEEE80211_RX_IN_SCAN;
2383 
2384 	ieee80211_parse_qos(&rx);
2385 	ieee80211_verify_alignment(&rx);
2386 
2387 	rx.sta = sta_info_get(local, hdr->addr2);
2388 	if (rx.sta)
2389 		rx.sdata = rx.sta->sdata;
2390 
2391 	if (rx.sdata && ieee80211_is_data(hdr->frame_control)) {
2392 		rx.flags |= IEEE80211_RX_RA_MATCH;
2393 		prepares = prepare_for_handlers(rx.sdata, &rx, hdr);
2394 		if (prepares) {
2395 			if (status->flag & RX_FLAG_MMIC_ERROR) {
2396 				if (rx.flags & IEEE80211_RX_RA_MATCH)
2397 					ieee80211_rx_michael_mic_report(hdr, &rx);
2398 			} else
2399 				prev = rx.sdata;
2400 		}
2401 	} else list_for_each_entry_rcu(sdata, &local->interfaces, list) {
2402 		if (!netif_running(sdata->dev))
2403 			continue;
2404 
2405 		if (sdata->vif.type == NL80211_IFTYPE_MONITOR ||
2406 		    sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
2407 			continue;
2408 
2409 		rx.flags |= IEEE80211_RX_RA_MATCH;
2410 		prepares = prepare_for_handlers(sdata, &rx, hdr);
2411 
2412 		if (!prepares)
2413 			continue;
2414 
2415 		if (status->flag & RX_FLAG_MMIC_ERROR) {
2416 			rx.sdata = sdata;
2417 			if (rx.flags & IEEE80211_RX_RA_MATCH)
2418 				ieee80211_rx_michael_mic_report(hdr, &rx);
2419 			continue;
2420 		}
2421 
2422 		/*
2423 		 * frame is destined for this interface, but if it's not
2424 		 * also for the previous one we handle that after the
2425 		 * loop to avoid copying the SKB once too much
2426 		 */
2427 
2428 		if (!prev) {
2429 			prev = sdata;
2430 			continue;
2431 		}
2432 
2433 		/*
2434 		 * frame was destined for the previous interface
2435 		 * so invoke RX handlers for it
2436 		 */
2437 
2438 		skb_new = skb_copy(skb, GFP_ATOMIC);
2439 		if (!skb_new) {
2440 			if (net_ratelimit())
2441 				printk(KERN_DEBUG "%s: failed to copy "
2442 				       "multicast frame for %s\n",
2443 				       wiphy_name(local->hw.wiphy),
2444 				       prev->dev->name);
2445 			continue;
2446 		}
2447 		ieee80211_invoke_rx_handlers(prev, &rx, skb_new, rate);
2448 		prev = sdata;
2449 	}
2450 	if (prev)
2451 		ieee80211_invoke_rx_handlers(prev, &rx, skb, rate);
2452 	else
2453 		dev_kfree_skb(skb);
2454 }
2455 
2456 /*
2457  * This is the receive path handler. It is called by a low level driver when an
2458  * 802.11 MPDU is received from the hardware.
2459  */
2460 void ieee80211_rx(struct ieee80211_hw *hw, struct sk_buff *skb)
2461 {
2462 	struct ieee80211_local *local = hw_to_local(hw);
2463 	struct ieee80211_rate *rate = NULL;
2464 	struct ieee80211_supported_band *sband;
2465 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
2466 
2467 	WARN_ON_ONCE(softirq_count() == 0);
2468 
2469 	if (WARN_ON(status->band < 0 ||
2470 		    status->band >= IEEE80211_NUM_BANDS))
2471 		goto drop;
2472 
2473 	sband = local->hw.wiphy->bands[status->band];
2474 	if (WARN_ON(!sband))
2475 		goto drop;
2476 
2477 	/*
2478 	 * If we're suspending, it is possible although not too likely
2479 	 * that we'd be receiving frames after having already partially
2480 	 * quiesced the stack. We can't process such frames then since
2481 	 * that might, for example, cause stations to be added or other
2482 	 * driver callbacks be invoked.
2483 	 */
2484 	if (unlikely(local->quiescing || local->suspended))
2485 		goto drop;
2486 
2487 	/*
2488 	 * The same happens when we're not even started,
2489 	 * but that's worth a warning.
2490 	 */
2491 	if (WARN_ON(!local->started))
2492 		goto drop;
2493 
2494 	if (status->flag & RX_FLAG_HT) {
2495 		/*
2496 		 * rate_idx is MCS index, which can be [0-76] as documented on:
2497 		 *
2498 		 * http://wireless.kernel.org/en/developers/Documentation/ieee80211/802.11n
2499 		 *
2500 		 * Anything else would be some sort of driver or hardware error.
2501 		 * The driver should catch hardware errors.
2502 		 */
2503 		if (WARN((status->rate_idx < 0 ||
2504 			 status->rate_idx > 76),
2505 			 "Rate marked as an HT rate but passed "
2506 			 "status->rate_idx is not "
2507 			 "an MCS index [0-76]: %d (0x%02x)\n",
2508 			 status->rate_idx,
2509 			 status->rate_idx))
2510 			goto drop;
2511 	} else {
2512 		if (WARN_ON(status->rate_idx < 0 ||
2513 			    status->rate_idx >= sband->n_bitrates))
2514 			goto drop;
2515 		rate = &sband->bitrates[status->rate_idx];
2516 	}
2517 
2518 	/*
2519 	 * key references and virtual interfaces are protected using RCU
2520 	 * and this requires that we are in a read-side RCU section during
2521 	 * receive processing
2522 	 */
2523 	rcu_read_lock();
2524 
2525 	/*
2526 	 * Frames with failed FCS/PLCP checksum are not returned,
2527 	 * all other frames are returned without radiotap header
2528 	 * if it was previously present.
2529 	 * Also, frames with less than 16 bytes are dropped.
2530 	 */
2531 	skb = ieee80211_rx_monitor(local, skb, rate);
2532 	if (!skb) {
2533 		rcu_read_unlock();
2534 		return;
2535 	}
2536 
2537 	__ieee80211_rx_handle_packet(hw, skb, rate);
2538 
2539 	rcu_read_unlock();
2540 
2541 	return;
2542  drop:
2543 	kfree_skb(skb);
2544 }
2545 EXPORT_SYMBOL(ieee80211_rx);
2546 
2547 /* This is a version of the rx handler that can be called from hard irq
2548  * context. Post the skb on the queue and schedule the tasklet */
2549 void ieee80211_rx_irqsafe(struct ieee80211_hw *hw, struct sk_buff *skb)
2550 {
2551 	struct ieee80211_local *local = hw_to_local(hw);
2552 
2553 	BUILD_BUG_ON(sizeof(struct ieee80211_rx_status) > sizeof(skb->cb));
2554 
2555 	skb->pkt_type = IEEE80211_RX_MSG;
2556 	skb_queue_tail(&local->skb_queue, skb);
2557 	tasklet_schedule(&local->tasklet);
2558 }
2559 EXPORT_SYMBOL(ieee80211_rx_irqsafe);
2560