xref: /openbmc/linux/net/mac80211/rx.c (revision a1e58bbd)
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/kernel.h>
13 #include <linux/skbuff.h>
14 #include <linux/netdevice.h>
15 #include <linux/etherdevice.h>
16 #include <linux/rcupdate.h>
17 #include <net/mac80211.h>
18 #include <net/ieee80211_radiotap.h>
19 
20 #include "ieee80211_i.h"
21 #include "ieee80211_led.h"
22 #include "wep.h"
23 #include "wpa.h"
24 #include "tkip.h"
25 #include "wme.h"
26 
27 u8 ieee80211_sta_manage_reorder_buf(struct ieee80211_hw *hw,
28 				struct tid_ampdu_rx *tid_agg_rx,
29 				struct sk_buff *skb, u16 mpdu_seq_num,
30 				int bar_req);
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 					   int rtap_len)
40 {
41 	skb_pull(skb, rtap_len);
42 
43 	if (local->hw.flags & IEEE80211_HW_RX_INCLUDES_FCS) {
44 		if (likely(skb->len > FCS_LEN))
45 			skb_trim(skb, skb->len - FCS_LEN);
46 		else {
47 			/* driver bug */
48 			WARN_ON(1);
49 			dev_kfree_skb(skb);
50 			skb = NULL;
51 		}
52 	}
53 
54 	return skb;
55 }
56 
57 static inline int should_drop_frame(struct ieee80211_rx_status *status,
58 				    struct sk_buff *skb,
59 				    int present_fcs_len,
60 				    int radiotap_len)
61 {
62 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
63 
64 	if (status->flag & (RX_FLAG_FAILED_FCS_CRC | RX_FLAG_FAILED_PLCP_CRC))
65 		return 1;
66 	if (unlikely(skb->len < 16 + present_fcs_len + radiotap_len))
67 		return 1;
68 	if (((hdr->frame_control & cpu_to_le16(IEEE80211_FCTL_FTYPE)) ==
69 			cpu_to_le16(IEEE80211_FTYPE_CTL)) &&
70 	    ((hdr->frame_control & cpu_to_le16(IEEE80211_FCTL_STYPE)) !=
71 			cpu_to_le16(IEEE80211_STYPE_PSPOLL)) &&
72 	    ((hdr->frame_control & cpu_to_le16(IEEE80211_FCTL_STYPE)) !=
73 			cpu_to_le16(IEEE80211_STYPE_BACK_REQ)))
74 		return 1;
75 	return 0;
76 }
77 
78 /*
79  * This function copies a received frame to all monitor interfaces and
80  * returns a cleaned-up SKB that no longer includes the FCS nor the
81  * radiotap header the driver might have added.
82  */
83 static struct sk_buff *
84 ieee80211_rx_monitor(struct ieee80211_local *local, struct sk_buff *origskb,
85 		     struct ieee80211_rx_status *status)
86 {
87 	struct ieee80211_sub_if_data *sdata;
88 	struct ieee80211_rate *rate;
89 	int needed_headroom = 0;
90 	struct ieee80211_radiotap_header *rthdr;
91 	__le64 *rttsft = NULL;
92 	struct ieee80211_rtap_fixed_data {
93 		u8 flags;
94 		u8 rate;
95 		__le16 chan_freq;
96 		__le16 chan_flags;
97 		u8 antsignal;
98 		u8 padding_for_rxflags;
99 		__le16 rx_flags;
100 	} __attribute__ ((packed)) *rtfixed;
101 	struct sk_buff *skb, *skb2;
102 	struct net_device *prev_dev = NULL;
103 	int present_fcs_len = 0;
104 	int rtap_len = 0;
105 
106 	/*
107 	 * First, we may need to make a copy of the skb because
108 	 *  (1) we need to modify it for radiotap (if not present), and
109 	 *  (2) the other RX handlers will modify the skb we got.
110 	 *
111 	 * We don't need to, of course, if we aren't going to return
112 	 * the SKB because it has a bad FCS/PLCP checksum.
113 	 */
114 	if (status->flag & RX_FLAG_RADIOTAP)
115 		rtap_len = ieee80211_get_radiotap_len(origskb->data);
116 	else
117 		/* room for radiotap header, always present fields and TSFT */
118 		needed_headroom = sizeof(*rthdr) + sizeof(*rtfixed) + 8;
119 
120 	if (local->hw.flags & IEEE80211_HW_RX_INCLUDES_FCS)
121 		present_fcs_len = FCS_LEN;
122 
123 	if (!local->monitors) {
124 		if (should_drop_frame(status, origskb, present_fcs_len,
125 				      rtap_len)) {
126 			dev_kfree_skb(origskb);
127 			return NULL;
128 		}
129 
130 		return remove_monitor_info(local, origskb, rtap_len);
131 	}
132 
133 	if (should_drop_frame(status, origskb, present_fcs_len, rtap_len)) {
134 		/* only need to expand headroom if necessary */
135 		skb = origskb;
136 		origskb = NULL;
137 
138 		/*
139 		 * This shouldn't trigger often because most devices have an
140 		 * RX header they pull before we get here, and that should
141 		 * be big enough for our radiotap information. We should
142 		 * probably export the length to drivers so that we can have
143 		 * them allocate enough headroom to start with.
144 		 */
145 		if (skb_headroom(skb) < needed_headroom &&
146 		    pskb_expand_head(skb, needed_headroom, 0, GFP_ATOMIC)) {
147 			dev_kfree_skb(skb);
148 			return NULL;
149 		}
150 	} else {
151 		/*
152 		 * Need to make a copy and possibly remove radiotap header
153 		 * and FCS from the original.
154 		 */
155 		skb = skb_copy_expand(origskb, needed_headroom, 0, GFP_ATOMIC);
156 
157 		origskb = remove_monitor_info(local, origskb, rtap_len);
158 
159 		if (!skb)
160 			return origskb;
161 	}
162 
163 	/* if necessary, prepend radiotap information */
164 	if (!(status->flag & RX_FLAG_RADIOTAP)) {
165 		rtfixed = (void *) skb_push(skb, sizeof(*rtfixed));
166 		rtap_len = sizeof(*rthdr) + sizeof(*rtfixed);
167 		if (status->flag & RX_FLAG_TSFT) {
168 			rttsft = (void *) skb_push(skb, sizeof(*rttsft));
169 			rtap_len += 8;
170 		}
171 		rthdr = (void *) skb_push(skb, sizeof(*rthdr));
172 		memset(rthdr, 0, sizeof(*rthdr));
173 		memset(rtfixed, 0, sizeof(*rtfixed));
174 		rthdr->it_present =
175 			cpu_to_le32((1 << IEEE80211_RADIOTAP_FLAGS) |
176 				    (1 << IEEE80211_RADIOTAP_RATE) |
177 				    (1 << IEEE80211_RADIOTAP_CHANNEL) |
178 				    (1 << IEEE80211_RADIOTAP_DB_ANTSIGNAL) |
179 				    (1 << IEEE80211_RADIOTAP_RX_FLAGS));
180 		rtfixed->flags = 0;
181 		if (local->hw.flags & IEEE80211_HW_RX_INCLUDES_FCS)
182 			rtfixed->flags |= IEEE80211_RADIOTAP_F_FCS;
183 
184 		if (rttsft) {
185 			*rttsft = cpu_to_le64(status->mactime);
186 			rthdr->it_present |=
187 				cpu_to_le32(1 << IEEE80211_RADIOTAP_TSFT);
188 		}
189 
190 		/* FIXME: when radiotap gets a 'bad PLCP' flag use it here */
191 		rtfixed->rx_flags = 0;
192 		if (status->flag &
193 		    (RX_FLAG_FAILED_FCS_CRC | RX_FLAG_FAILED_PLCP_CRC))
194 			rtfixed->rx_flags |=
195 				cpu_to_le16(IEEE80211_RADIOTAP_F_RX_BADFCS);
196 
197 		rate = ieee80211_get_rate(local, status->phymode,
198 					  status->rate);
199 		if (rate)
200 			rtfixed->rate = rate->rate / 5;
201 
202 		rtfixed->chan_freq = cpu_to_le16(status->freq);
203 
204 		if (status->phymode == MODE_IEEE80211A)
205 			rtfixed->chan_flags =
206 				cpu_to_le16(IEEE80211_CHAN_OFDM |
207 					    IEEE80211_CHAN_5GHZ);
208 		else
209 			rtfixed->chan_flags =
210 				cpu_to_le16(IEEE80211_CHAN_DYN |
211 					    IEEE80211_CHAN_2GHZ);
212 
213 		rtfixed->antsignal = status->ssi;
214 		rthdr->it_len = cpu_to_le16(rtap_len);
215 	}
216 
217 	skb_reset_mac_header(skb);
218 	skb->ip_summed = CHECKSUM_UNNECESSARY;
219 	skb->pkt_type = PACKET_OTHERHOST;
220 	skb->protocol = htons(ETH_P_802_2);
221 
222 	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
223 		if (!netif_running(sdata->dev))
224 			continue;
225 
226 		if (sdata->vif.type != IEEE80211_IF_TYPE_MNTR)
227 			continue;
228 
229 		if (prev_dev) {
230 			skb2 = skb_clone(skb, GFP_ATOMIC);
231 			if (skb2) {
232 				skb2->dev = prev_dev;
233 				netif_rx(skb2);
234 			}
235 		}
236 
237 		prev_dev = sdata->dev;
238 		sdata->dev->stats.rx_packets++;
239 		sdata->dev->stats.rx_bytes += skb->len;
240 	}
241 
242 	if (prev_dev) {
243 		skb->dev = prev_dev;
244 		netif_rx(skb);
245 	} else
246 		dev_kfree_skb(skb);
247 
248 	return origskb;
249 }
250 
251 
252 /* pre-rx handlers
253  *
254  * these don't have dev/sdata fields in the rx data
255  * The sta value should also not be used because it may
256  * be NULL even though a STA (in IBSS mode) will be added.
257  */
258 
259 static ieee80211_txrx_result
260 ieee80211_rx_h_parse_qos(struct ieee80211_txrx_data *rx)
261 {
262 	u8 *data = rx->skb->data;
263 	int tid;
264 
265 	/* does the frame have a qos control field? */
266 	if (WLAN_FC_IS_QOS_DATA(rx->fc)) {
267 		u8 *qc = data + ieee80211_get_hdrlen(rx->fc) - QOS_CONTROL_LEN;
268 		/* frame has qos control */
269 		tid = qc[0] & QOS_CONTROL_TID_MASK;
270 		if (qc[0] & IEEE80211_QOS_CONTROL_A_MSDU_PRESENT)
271 			rx->flags |= IEEE80211_TXRXD_RX_AMSDU;
272 		else
273 			rx->flags &= ~IEEE80211_TXRXD_RX_AMSDU;
274 	} else {
275 		if (unlikely((rx->fc & IEEE80211_FCTL_FTYPE) == IEEE80211_FTYPE_MGMT)) {
276 			/* Separate TID for management frames */
277 			tid = NUM_RX_DATA_QUEUES - 1;
278 		} else {
279 			/* no qos control present */
280 			tid = 0; /* 802.1d - Best Effort */
281 		}
282 	}
283 
284 	I802_DEBUG_INC(rx->local->wme_rx_queue[tid]);
285 	/* only a debug counter, sta might not be assigned properly yet */
286 	if (rx->sta)
287 		I802_DEBUG_INC(rx->sta->wme_rx_queue[tid]);
288 
289 	rx->u.rx.queue = tid;
290 	/* Set skb->priority to 1d tag if highest order bit of TID is not set.
291 	 * For now, set skb->priority to 0 for other cases. */
292 	rx->skb->priority = (tid > 7) ? 0 : tid;
293 
294 	return TXRX_CONTINUE;
295 }
296 
297 
298 static u32 ieee80211_rx_load_stats(struct ieee80211_local *local,
299 			      struct sk_buff *skb,
300 			      struct ieee80211_rx_status *status)
301 {
302 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
303 	u32 load = 0, hdrtime;
304 	struct ieee80211_rate *rate;
305 	struct ieee80211_hw_mode *mode = local->hw.conf.mode;
306 	int i;
307 
308 	/* Estimate total channel use caused by this frame */
309 
310 	if (unlikely(mode->num_rates < 0))
311 		return TXRX_CONTINUE;
312 
313 	rate = &mode->rates[0];
314 	for (i = 0; i < mode->num_rates; i++) {
315 		if (mode->rates[i].val == status->rate) {
316 			rate = &mode->rates[i];
317 			break;
318 		}
319 	}
320 
321 	/* 1 bit at 1 Mbit/s takes 1 usec; in channel_use values,
322 	 * 1 usec = 1/8 * (1080 / 10) = 13.5 */
323 
324 	if (mode->mode == MODE_IEEE80211A ||
325 	    (mode->mode == MODE_IEEE80211G &&
326 	     rate->flags & IEEE80211_RATE_ERP))
327 		hdrtime = CHAN_UTIL_HDR_SHORT;
328 	else
329 		hdrtime = CHAN_UTIL_HDR_LONG;
330 
331 	load = hdrtime;
332 	if (!is_multicast_ether_addr(hdr->addr1))
333 		load += hdrtime;
334 
335 	load += skb->len * rate->rate_inv;
336 
337 	/* Divide channel_use by 8 to avoid wrapping around the counter */
338 	load >>= CHAN_UTIL_SHIFT;
339 
340 	return load;
341 }
342 
343 #ifdef CONFIG_MAC80211_DEBUG_PACKET_ALIGNMENT
344 static ieee80211_txrx_result
345 ieee80211_rx_h_verify_ip_alignment(struct ieee80211_txrx_data *rx)
346 {
347 	int hdrlen;
348 
349 	if (!WLAN_FC_DATA_PRESENT(rx->fc))
350 		return TXRX_CONTINUE;
351 
352 	/*
353 	 * Drivers are required to align the payload data in a way that
354 	 * guarantees that the contained IP header is aligned to a four-
355 	 * byte boundary. In the case of regular frames, this simply means
356 	 * aligning the payload to a four-byte boundary (because either
357 	 * the IP header is directly contained, or IV/RFC1042 headers that
358 	 * have a length divisible by four are in front of it.
359 	 *
360 	 * With A-MSDU frames, however, the payload data address must
361 	 * yield two modulo four because there are 14-byte 802.3 headers
362 	 * within the A-MSDU frames that push the IP header further back
363 	 * to a multiple of four again. Thankfully, the specs were sane
364 	 * enough this time around to require padding each A-MSDU subframe
365 	 * to a length that is a multiple of four.
366 	 *
367 	 * Padding like atheros hardware adds which is inbetween the 802.11
368 	 * header and the payload is not supported, the driver is required
369 	 * to move the 802.11 header further back in that case.
370 	 */
371 	hdrlen = ieee80211_get_hdrlen(rx->fc);
372 	if (rx->flags & IEEE80211_TXRXD_RX_AMSDU)
373 		hdrlen += ETH_HLEN;
374 	WARN_ON_ONCE(((unsigned long)(rx->skb->data + hdrlen)) & 3);
375 
376 	return TXRX_CONTINUE;
377 }
378 #endif
379 
380 ieee80211_rx_handler ieee80211_rx_pre_handlers[] =
381 {
382 	ieee80211_rx_h_parse_qos,
383 #ifdef CONFIG_MAC80211_DEBUG_PACKET_ALIGNMENT
384 	ieee80211_rx_h_verify_ip_alignment,
385 #endif
386 	NULL
387 };
388 
389 /* rx handlers */
390 
391 static ieee80211_txrx_result
392 ieee80211_rx_h_if_stats(struct ieee80211_txrx_data *rx)
393 {
394 	if (rx->sta)
395 		rx->sta->channel_use_raw += rx->u.rx.load;
396 	rx->sdata->channel_use_raw += rx->u.rx.load;
397 	return TXRX_CONTINUE;
398 }
399 
400 static ieee80211_txrx_result
401 ieee80211_rx_h_passive_scan(struct ieee80211_txrx_data *rx)
402 {
403 	struct ieee80211_local *local = rx->local;
404 	struct sk_buff *skb = rx->skb;
405 
406 	if (unlikely(local->sta_hw_scanning))
407 		return ieee80211_sta_rx_scan(rx->dev, skb, rx->u.rx.status);
408 
409 	if (unlikely(local->sta_sw_scanning)) {
410 		/* drop all the other packets during a software scan anyway */
411 		if (ieee80211_sta_rx_scan(rx->dev, skb, rx->u.rx.status)
412 		    != TXRX_QUEUED)
413 			dev_kfree_skb(skb);
414 		return TXRX_QUEUED;
415 	}
416 
417 	if (unlikely(rx->flags & IEEE80211_TXRXD_RXIN_SCAN)) {
418 		/* scanning finished during invoking of handlers */
419 		I802_DEBUG_INC(local->rx_handlers_drop_passive_scan);
420 		return TXRX_DROP;
421 	}
422 
423 	return TXRX_CONTINUE;
424 }
425 
426 static ieee80211_txrx_result
427 ieee80211_rx_h_check(struct ieee80211_txrx_data *rx)
428 {
429 	struct ieee80211_hdr *hdr;
430 	hdr = (struct ieee80211_hdr *) rx->skb->data;
431 
432 	/* Drop duplicate 802.11 retransmissions (IEEE 802.11 Chap. 9.2.9) */
433 	if (rx->sta && !is_multicast_ether_addr(hdr->addr1)) {
434 		if (unlikely(rx->fc & IEEE80211_FCTL_RETRY &&
435 			     rx->sta->last_seq_ctrl[rx->u.rx.queue] ==
436 			     hdr->seq_ctrl)) {
437 			if (rx->flags & IEEE80211_TXRXD_RXRA_MATCH) {
438 				rx->local->dot11FrameDuplicateCount++;
439 				rx->sta->num_duplicates++;
440 			}
441 			return TXRX_DROP;
442 		} else
443 			rx->sta->last_seq_ctrl[rx->u.rx.queue] = hdr->seq_ctrl;
444 	}
445 
446 	if (unlikely(rx->skb->len < 16)) {
447 		I802_DEBUG_INC(rx->local->rx_handlers_drop_short);
448 		return TXRX_DROP;
449 	}
450 
451 	/* Drop disallowed frame classes based on STA auth/assoc state;
452 	 * IEEE 802.11, Chap 5.5.
453 	 *
454 	 * 80211.o does filtering only based on association state, i.e., it
455 	 * drops Class 3 frames from not associated stations. hostapd sends
456 	 * deauth/disassoc frames when needed. In addition, hostapd is
457 	 * responsible for filtering on both auth and assoc states.
458 	 */
459 	if (unlikely(((rx->fc & IEEE80211_FCTL_FTYPE) == IEEE80211_FTYPE_DATA ||
460 		      ((rx->fc & IEEE80211_FCTL_FTYPE) == IEEE80211_FTYPE_CTL &&
461 		       (rx->fc & IEEE80211_FCTL_STYPE) == IEEE80211_STYPE_PSPOLL)) &&
462 		     rx->sdata->vif.type != IEEE80211_IF_TYPE_IBSS &&
463 		     (!rx->sta || !(rx->sta->flags & WLAN_STA_ASSOC)))) {
464 		if ((!(rx->fc & IEEE80211_FCTL_FROMDS) &&
465 		     !(rx->fc & IEEE80211_FCTL_TODS) &&
466 		     (rx->fc & IEEE80211_FCTL_FTYPE) == IEEE80211_FTYPE_DATA)
467 		    || !(rx->flags & IEEE80211_TXRXD_RXRA_MATCH)) {
468 			/* Drop IBSS frames and frames for other hosts
469 			 * silently. */
470 			return TXRX_DROP;
471 		}
472 
473 		return TXRX_DROP;
474 	}
475 
476 	return TXRX_CONTINUE;
477 }
478 
479 
480 static ieee80211_txrx_result
481 ieee80211_rx_h_decrypt(struct ieee80211_txrx_data *rx)
482 {
483 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) rx->skb->data;
484 	int keyidx;
485 	int hdrlen;
486 	ieee80211_txrx_result result = TXRX_DROP;
487 	struct ieee80211_key *stakey = NULL;
488 
489 	/*
490 	 * Key selection 101
491 	 *
492 	 * There are three types of keys:
493 	 *  - GTK (group keys)
494 	 *  - PTK (pairwise keys)
495 	 *  - STK (station-to-station pairwise keys)
496 	 *
497 	 * When selecting a key, we have to distinguish between multicast
498 	 * (including broadcast) and unicast frames, the latter can only
499 	 * use PTKs and STKs while the former always use GTKs. Unless, of
500 	 * course, actual WEP keys ("pre-RSNA") are used, then unicast
501 	 * frames can also use key indizes like GTKs. Hence, if we don't
502 	 * have a PTK/STK we check the key index for a WEP key.
503 	 *
504 	 * Note that in a regular BSS, multicast frames are sent by the
505 	 * AP only, associated stations unicast the frame to the AP first
506 	 * which then multicasts it on their behalf.
507 	 *
508 	 * There is also a slight problem in IBSS mode: GTKs are negotiated
509 	 * with each station, that is something we don't currently handle.
510 	 * The spec seems to expect that one negotiates the same key with
511 	 * every station but there's no such requirement; VLANs could be
512 	 * possible.
513 	 */
514 
515 	if (!(rx->fc & IEEE80211_FCTL_PROTECTED))
516 		return TXRX_CONTINUE;
517 
518 	/*
519 	 * No point in finding a key and decrypting if the frame is neither
520 	 * addressed to us nor a multicast frame.
521 	 */
522 	if (!(rx->flags & IEEE80211_TXRXD_RXRA_MATCH))
523 		return TXRX_CONTINUE;
524 
525 	if (rx->sta)
526 		stakey = rcu_dereference(rx->sta->key);
527 
528 	if (!is_multicast_ether_addr(hdr->addr1) && stakey) {
529 		rx->key = stakey;
530 	} else {
531 		/*
532 		 * The device doesn't give us the IV so we won't be
533 		 * able to look up the key. That's ok though, we
534 		 * don't need to decrypt the frame, we just won't
535 		 * be able to keep statistics accurate.
536 		 * Except for key threshold notifications, should
537 		 * we somehow allow the driver to tell us which key
538 		 * the hardware used if this flag is set?
539 		 */
540 		if ((rx->u.rx.status->flag & RX_FLAG_DECRYPTED) &&
541 		    (rx->u.rx.status->flag & RX_FLAG_IV_STRIPPED))
542 			return TXRX_CONTINUE;
543 
544 		hdrlen = ieee80211_get_hdrlen(rx->fc);
545 
546 		if (rx->skb->len < 8 + hdrlen)
547 			return TXRX_DROP; /* TODO: count this? */
548 
549 		/*
550 		 * no need to call ieee80211_wep_get_keyidx,
551 		 * it verifies a bunch of things we've done already
552 		 */
553 		keyidx = rx->skb->data[hdrlen + 3] >> 6;
554 
555 		rx->key = rcu_dereference(rx->sdata->keys[keyidx]);
556 
557 		/*
558 		 * RSNA-protected unicast frames should always be sent with
559 		 * pairwise or station-to-station keys, but for WEP we allow
560 		 * using a key index as well.
561 		 */
562 		if (rx->key && rx->key->conf.alg != ALG_WEP &&
563 		    !is_multicast_ether_addr(hdr->addr1))
564 			rx->key = NULL;
565 	}
566 
567 	if (rx->key) {
568 		rx->key->tx_rx_count++;
569 		/* TODO: add threshold stuff again */
570 	} else {
571 #ifdef CONFIG_MAC80211_DEBUG
572 		if (net_ratelimit())
573 			printk(KERN_DEBUG "%s: RX protected frame,"
574 			       " but have no key\n", rx->dev->name);
575 #endif /* CONFIG_MAC80211_DEBUG */
576 		return TXRX_DROP;
577 	}
578 
579 	/* Check for weak IVs if possible */
580 	if (rx->sta && rx->key->conf.alg == ALG_WEP &&
581 	    ((rx->fc & IEEE80211_FCTL_FTYPE) == IEEE80211_FTYPE_DATA) &&
582 	    (!(rx->u.rx.status->flag & RX_FLAG_IV_STRIPPED) ||
583 	     !(rx->u.rx.status->flag & RX_FLAG_DECRYPTED)) &&
584 	    ieee80211_wep_is_weak_iv(rx->skb, rx->key))
585 		rx->sta->wep_weak_iv_count++;
586 
587 	switch (rx->key->conf.alg) {
588 	case ALG_WEP:
589 		result = ieee80211_crypto_wep_decrypt(rx);
590 		break;
591 	case ALG_TKIP:
592 		result = ieee80211_crypto_tkip_decrypt(rx);
593 		break;
594 	case ALG_CCMP:
595 		result = ieee80211_crypto_ccmp_decrypt(rx);
596 		break;
597 	}
598 
599 	/* either the frame has been decrypted or will be dropped */
600 	rx->u.rx.status->flag |= RX_FLAG_DECRYPTED;
601 
602 	return result;
603 }
604 
605 static void ap_sta_ps_start(struct net_device *dev, struct sta_info *sta)
606 {
607 	struct ieee80211_sub_if_data *sdata;
608 	DECLARE_MAC_BUF(mac);
609 
610 	sdata = IEEE80211_DEV_TO_SUB_IF(sta->dev);
611 
612 	if (sdata->bss)
613 		atomic_inc(&sdata->bss->num_sta_ps);
614 	sta->flags |= WLAN_STA_PS;
615 	sta->pspoll = 0;
616 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
617 	printk(KERN_DEBUG "%s: STA %s aid %d enters power save mode\n",
618 	       dev->name, print_mac(mac, sta->addr), sta->aid);
619 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
620 }
621 
622 static int ap_sta_ps_end(struct net_device *dev, struct sta_info *sta)
623 {
624 	struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
625 	struct sk_buff *skb;
626 	int sent = 0;
627 	struct ieee80211_sub_if_data *sdata;
628 	struct ieee80211_tx_packet_data *pkt_data;
629 	DECLARE_MAC_BUF(mac);
630 
631 	sdata = IEEE80211_DEV_TO_SUB_IF(sta->dev);
632 	if (sdata->bss)
633 		atomic_dec(&sdata->bss->num_sta_ps);
634 	sta->flags &= ~(WLAN_STA_PS | WLAN_STA_TIM);
635 	sta->pspoll = 0;
636 	if (!skb_queue_empty(&sta->ps_tx_buf)) {
637 		if (local->ops->set_tim)
638 			local->ops->set_tim(local_to_hw(local), sta->aid, 0);
639 		if (sdata->bss)
640 			bss_tim_clear(local, sdata->bss, sta->aid);
641 	}
642 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
643 	printk(KERN_DEBUG "%s: STA %s aid %d exits power save mode\n",
644 	       dev->name, print_mac(mac, sta->addr), sta->aid);
645 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
646 	/* Send all buffered frames to the station */
647 	while ((skb = skb_dequeue(&sta->tx_filtered)) != NULL) {
648 		pkt_data = (struct ieee80211_tx_packet_data *) skb->cb;
649 		sent++;
650 		pkt_data->flags |= IEEE80211_TXPD_REQUEUE;
651 		dev_queue_xmit(skb);
652 	}
653 	while ((skb = skb_dequeue(&sta->ps_tx_buf)) != NULL) {
654 		pkt_data = (struct ieee80211_tx_packet_data *) skb->cb;
655 		local->total_ps_buffered--;
656 		sent++;
657 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
658 		printk(KERN_DEBUG "%s: STA %s aid %d send PS frame "
659 		       "since STA not sleeping anymore\n", dev->name,
660 		       print_mac(mac, sta->addr), sta->aid);
661 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
662 		pkt_data->flags |= IEEE80211_TXPD_REQUEUE;
663 		dev_queue_xmit(skb);
664 	}
665 
666 	return sent;
667 }
668 
669 static ieee80211_txrx_result
670 ieee80211_rx_h_sta_process(struct ieee80211_txrx_data *rx)
671 {
672 	struct sta_info *sta = rx->sta;
673 	struct net_device *dev = rx->dev;
674 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) rx->skb->data;
675 
676 	if (!sta)
677 		return TXRX_CONTINUE;
678 
679 	/* Update last_rx only for IBSS packets which are for the current
680 	 * BSSID to avoid keeping the current IBSS network alive in cases where
681 	 * other STAs are using different BSSID. */
682 	if (rx->sdata->vif.type == IEEE80211_IF_TYPE_IBSS) {
683 		u8 *bssid = ieee80211_get_bssid(hdr, rx->skb->len,
684 						IEEE80211_IF_TYPE_IBSS);
685 		if (compare_ether_addr(bssid, rx->sdata->u.sta.bssid) == 0)
686 			sta->last_rx = jiffies;
687 	} else
688 	if (!is_multicast_ether_addr(hdr->addr1) ||
689 	    rx->sdata->vif.type == IEEE80211_IF_TYPE_STA) {
690 		/* Update last_rx only for unicast frames in order to prevent
691 		 * the Probe Request frames (the only broadcast frames from a
692 		 * STA in infrastructure mode) from keeping a connection alive.
693 		 */
694 		sta->last_rx = jiffies;
695 	}
696 
697 	if (!(rx->flags & IEEE80211_TXRXD_RXRA_MATCH))
698 		return TXRX_CONTINUE;
699 
700 	sta->rx_fragments++;
701 	sta->rx_bytes += rx->skb->len;
702 	sta->last_rssi = rx->u.rx.status->ssi;
703 	sta->last_signal = rx->u.rx.status->signal;
704 	sta->last_noise = rx->u.rx.status->noise;
705 
706 	if (!(rx->fc & IEEE80211_FCTL_MOREFRAGS)) {
707 		/* Change STA power saving mode only in the end of a frame
708 		 * exchange sequence */
709 		if ((sta->flags & WLAN_STA_PS) && !(rx->fc & IEEE80211_FCTL_PM))
710 			rx->u.rx.sent_ps_buffered += ap_sta_ps_end(dev, sta);
711 		else if (!(sta->flags & WLAN_STA_PS) &&
712 			 (rx->fc & IEEE80211_FCTL_PM))
713 			ap_sta_ps_start(dev, sta);
714 	}
715 
716 	/* Drop data::nullfunc frames silently, since they are used only to
717 	 * control station power saving mode. */
718 	if ((rx->fc & IEEE80211_FCTL_FTYPE) == IEEE80211_FTYPE_DATA &&
719 	    (rx->fc & IEEE80211_FCTL_STYPE) == IEEE80211_STYPE_NULLFUNC) {
720 		I802_DEBUG_INC(rx->local->rx_handlers_drop_nullfunc);
721 		/* Update counter and free packet here to avoid counting this
722 		 * as a dropped packed. */
723 		sta->rx_packets++;
724 		dev_kfree_skb(rx->skb);
725 		return TXRX_QUEUED;
726 	}
727 
728 	return TXRX_CONTINUE;
729 } /* ieee80211_rx_h_sta_process */
730 
731 static inline struct ieee80211_fragment_entry *
732 ieee80211_reassemble_add(struct ieee80211_sub_if_data *sdata,
733 			 unsigned int frag, unsigned int seq, int rx_queue,
734 			 struct sk_buff **skb)
735 {
736 	struct ieee80211_fragment_entry *entry;
737 	int idx;
738 
739 	idx = sdata->fragment_next;
740 	entry = &sdata->fragments[sdata->fragment_next++];
741 	if (sdata->fragment_next >= IEEE80211_FRAGMENT_MAX)
742 		sdata->fragment_next = 0;
743 
744 	if (!skb_queue_empty(&entry->skb_list)) {
745 #ifdef CONFIG_MAC80211_DEBUG
746 		struct ieee80211_hdr *hdr =
747 			(struct ieee80211_hdr *) entry->skb_list.next->data;
748 		DECLARE_MAC_BUF(mac);
749 		DECLARE_MAC_BUF(mac2);
750 		printk(KERN_DEBUG "%s: RX reassembly removed oldest "
751 		       "fragment entry (idx=%d age=%lu seq=%d last_frag=%d "
752 		       "addr1=%s addr2=%s\n",
753 		       sdata->dev->name, idx,
754 		       jiffies - entry->first_frag_time, entry->seq,
755 		       entry->last_frag, print_mac(mac, hdr->addr1),
756 		       print_mac(mac2, hdr->addr2));
757 #endif /* CONFIG_MAC80211_DEBUG */
758 		__skb_queue_purge(&entry->skb_list);
759 	}
760 
761 	__skb_queue_tail(&entry->skb_list, *skb); /* no need for locking */
762 	*skb = NULL;
763 	entry->first_frag_time = jiffies;
764 	entry->seq = seq;
765 	entry->rx_queue = rx_queue;
766 	entry->last_frag = frag;
767 	entry->ccmp = 0;
768 	entry->extra_len = 0;
769 
770 	return entry;
771 }
772 
773 static inline struct ieee80211_fragment_entry *
774 ieee80211_reassemble_find(struct ieee80211_sub_if_data *sdata,
775 			  u16 fc, unsigned int frag, unsigned int seq,
776 			  int rx_queue, struct ieee80211_hdr *hdr)
777 {
778 	struct ieee80211_fragment_entry *entry;
779 	int i, idx;
780 
781 	idx = sdata->fragment_next;
782 	for (i = 0; i < IEEE80211_FRAGMENT_MAX; i++) {
783 		struct ieee80211_hdr *f_hdr;
784 		u16 f_fc;
785 
786 		idx--;
787 		if (idx < 0)
788 			idx = IEEE80211_FRAGMENT_MAX - 1;
789 
790 		entry = &sdata->fragments[idx];
791 		if (skb_queue_empty(&entry->skb_list) || entry->seq != seq ||
792 		    entry->rx_queue != rx_queue ||
793 		    entry->last_frag + 1 != frag)
794 			continue;
795 
796 		f_hdr = (struct ieee80211_hdr *) entry->skb_list.next->data;
797 		f_fc = le16_to_cpu(f_hdr->frame_control);
798 
799 		if ((fc & IEEE80211_FCTL_FTYPE) != (f_fc & IEEE80211_FCTL_FTYPE) ||
800 		    compare_ether_addr(hdr->addr1, f_hdr->addr1) != 0 ||
801 		    compare_ether_addr(hdr->addr2, f_hdr->addr2) != 0)
802 			continue;
803 
804 		if (entry->first_frag_time + 2 * HZ < jiffies) {
805 			__skb_queue_purge(&entry->skb_list);
806 			continue;
807 		}
808 		return entry;
809 	}
810 
811 	return NULL;
812 }
813 
814 static ieee80211_txrx_result
815 ieee80211_rx_h_defragment(struct ieee80211_txrx_data *rx)
816 {
817 	struct ieee80211_hdr *hdr;
818 	u16 sc;
819 	unsigned int frag, seq;
820 	struct ieee80211_fragment_entry *entry;
821 	struct sk_buff *skb;
822 	DECLARE_MAC_BUF(mac);
823 
824 	hdr = (struct ieee80211_hdr *) rx->skb->data;
825 	sc = le16_to_cpu(hdr->seq_ctrl);
826 	frag = sc & IEEE80211_SCTL_FRAG;
827 
828 	if (likely((!(rx->fc & IEEE80211_FCTL_MOREFRAGS) && frag == 0) ||
829 		   (rx->skb)->len < 24 ||
830 		   is_multicast_ether_addr(hdr->addr1))) {
831 		/* not fragmented */
832 		goto out;
833 	}
834 	I802_DEBUG_INC(rx->local->rx_handlers_fragments);
835 
836 	seq = (sc & IEEE80211_SCTL_SEQ) >> 4;
837 
838 	if (frag == 0) {
839 		/* This is the first fragment of a new frame. */
840 		entry = ieee80211_reassemble_add(rx->sdata, frag, seq,
841 						 rx->u.rx.queue, &(rx->skb));
842 		if (rx->key && rx->key->conf.alg == ALG_CCMP &&
843 		    (rx->fc & IEEE80211_FCTL_PROTECTED)) {
844 			/* Store CCMP PN so that we can verify that the next
845 			 * fragment has a sequential PN value. */
846 			entry->ccmp = 1;
847 			memcpy(entry->last_pn,
848 			       rx->key->u.ccmp.rx_pn[rx->u.rx.queue],
849 			       CCMP_PN_LEN);
850 		}
851 		return TXRX_QUEUED;
852 	}
853 
854 	/* This is a fragment for a frame that should already be pending in
855 	 * fragment cache. Add this fragment to the end of the pending entry.
856 	 */
857 	entry = ieee80211_reassemble_find(rx->sdata, rx->fc, frag, seq,
858 					  rx->u.rx.queue, hdr);
859 	if (!entry) {
860 		I802_DEBUG_INC(rx->local->rx_handlers_drop_defrag);
861 		return TXRX_DROP;
862 	}
863 
864 	/* Verify that MPDUs within one MSDU have sequential PN values.
865 	 * (IEEE 802.11i, 8.3.3.4.5) */
866 	if (entry->ccmp) {
867 		int i;
868 		u8 pn[CCMP_PN_LEN], *rpn;
869 		if (!rx->key || rx->key->conf.alg != ALG_CCMP)
870 			return TXRX_DROP;
871 		memcpy(pn, entry->last_pn, CCMP_PN_LEN);
872 		for (i = CCMP_PN_LEN - 1; i >= 0; i--) {
873 			pn[i]++;
874 			if (pn[i])
875 				break;
876 		}
877 		rpn = rx->key->u.ccmp.rx_pn[rx->u.rx.queue];
878 		if (memcmp(pn, rpn, CCMP_PN_LEN) != 0) {
879 			if (net_ratelimit())
880 				printk(KERN_DEBUG "%s: defrag: CCMP PN not "
881 				       "sequential A2=%s"
882 				       " PN=%02x%02x%02x%02x%02x%02x "
883 				       "(expected %02x%02x%02x%02x%02x%02x)\n",
884 				       rx->dev->name, print_mac(mac, hdr->addr2),
885 				       rpn[0], rpn[1], rpn[2], rpn[3], rpn[4],
886 				       rpn[5], pn[0], pn[1], pn[2], pn[3],
887 				       pn[4], pn[5]);
888 			return TXRX_DROP;
889 		}
890 		memcpy(entry->last_pn, pn, CCMP_PN_LEN);
891 	}
892 
893 	skb_pull(rx->skb, ieee80211_get_hdrlen(rx->fc));
894 	__skb_queue_tail(&entry->skb_list, rx->skb);
895 	entry->last_frag = frag;
896 	entry->extra_len += rx->skb->len;
897 	if (rx->fc & IEEE80211_FCTL_MOREFRAGS) {
898 		rx->skb = NULL;
899 		return TXRX_QUEUED;
900 	}
901 
902 	rx->skb = __skb_dequeue(&entry->skb_list);
903 	if (skb_tailroom(rx->skb) < entry->extra_len) {
904 		I802_DEBUG_INC(rx->local->rx_expand_skb_head2);
905 		if (unlikely(pskb_expand_head(rx->skb, 0, entry->extra_len,
906 					      GFP_ATOMIC))) {
907 			I802_DEBUG_INC(rx->local->rx_handlers_drop_defrag);
908 			__skb_queue_purge(&entry->skb_list);
909 			return TXRX_DROP;
910 		}
911 	}
912 	while ((skb = __skb_dequeue(&entry->skb_list))) {
913 		memcpy(skb_put(rx->skb, skb->len), skb->data, skb->len);
914 		dev_kfree_skb(skb);
915 	}
916 
917 	/* Complete frame has been reassembled - process it now */
918 	rx->flags |= IEEE80211_TXRXD_FRAGMENTED;
919 
920  out:
921 	if (rx->sta)
922 		rx->sta->rx_packets++;
923 	if (is_multicast_ether_addr(hdr->addr1))
924 		rx->local->dot11MulticastReceivedFrameCount++;
925 	else
926 		ieee80211_led_rx(rx->local);
927 	return TXRX_CONTINUE;
928 }
929 
930 static ieee80211_txrx_result
931 ieee80211_rx_h_ps_poll(struct ieee80211_txrx_data *rx)
932 {
933 	struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(rx->dev);
934 	struct sk_buff *skb;
935 	int no_pending_pkts;
936 	DECLARE_MAC_BUF(mac);
937 
938 	if (likely(!rx->sta ||
939 		   (rx->fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_CTL ||
940 		   (rx->fc & IEEE80211_FCTL_STYPE) != IEEE80211_STYPE_PSPOLL ||
941 		   !(rx->flags & IEEE80211_TXRXD_RXRA_MATCH)))
942 		return TXRX_CONTINUE;
943 
944 	if ((sdata->vif.type != IEEE80211_IF_TYPE_AP) &&
945 	    (sdata->vif.type != IEEE80211_IF_TYPE_VLAN))
946 		return TXRX_DROP;
947 
948 	skb = skb_dequeue(&rx->sta->tx_filtered);
949 	if (!skb) {
950 		skb = skb_dequeue(&rx->sta->ps_tx_buf);
951 		if (skb)
952 			rx->local->total_ps_buffered--;
953 	}
954 	no_pending_pkts = skb_queue_empty(&rx->sta->tx_filtered) &&
955 		skb_queue_empty(&rx->sta->ps_tx_buf);
956 
957 	if (skb) {
958 		struct ieee80211_hdr *hdr =
959 			(struct ieee80211_hdr *) skb->data;
960 
961 		/* tell TX path to send one frame even though the STA may
962 		 * still remain is PS mode after this frame exchange */
963 		rx->sta->pspoll = 1;
964 
965 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
966 		printk(KERN_DEBUG "STA %s aid %d: PS Poll (entries after %d)\n",
967 		       print_mac(mac, rx->sta->addr), rx->sta->aid,
968 		       skb_queue_len(&rx->sta->ps_tx_buf));
969 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
970 
971 		/* Use MoreData flag to indicate whether there are more
972 		 * buffered frames for this STA */
973 		if (no_pending_pkts) {
974 			hdr->frame_control &= cpu_to_le16(~IEEE80211_FCTL_MOREDATA);
975 			rx->sta->flags &= ~WLAN_STA_TIM;
976 		} else
977 			hdr->frame_control |= cpu_to_le16(IEEE80211_FCTL_MOREDATA);
978 
979 		dev_queue_xmit(skb);
980 
981 		if (no_pending_pkts) {
982 			if (rx->local->ops->set_tim)
983 				rx->local->ops->set_tim(local_to_hw(rx->local),
984 						       rx->sta->aid, 0);
985 			if (rx->sdata->bss)
986 				bss_tim_clear(rx->local, rx->sdata->bss, rx->sta->aid);
987 		}
988 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
989 	} else if (!rx->u.rx.sent_ps_buffered) {
990 		printk(KERN_DEBUG "%s: STA %s sent PS Poll even "
991 		       "though there is no buffered frames for it\n",
992 		       rx->dev->name, print_mac(mac, rx->sta->addr));
993 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
994 
995 	}
996 
997 	/* Free PS Poll skb here instead of returning TXRX_DROP that would
998 	 * count as an dropped frame. */
999 	dev_kfree_skb(rx->skb);
1000 
1001 	return TXRX_QUEUED;
1002 }
1003 
1004 static ieee80211_txrx_result
1005 ieee80211_rx_h_remove_qos_control(struct ieee80211_txrx_data *rx)
1006 {
1007 	u16 fc = rx->fc;
1008 	u8 *data = rx->skb->data;
1009 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) data;
1010 
1011 	if (!WLAN_FC_IS_QOS_DATA(fc))
1012 		return TXRX_CONTINUE;
1013 
1014 	/* remove the qos control field, update frame type and meta-data */
1015 	memmove(data + 2, data, ieee80211_get_hdrlen(fc) - 2);
1016 	hdr = (struct ieee80211_hdr *) skb_pull(rx->skb, 2);
1017 	/* change frame type to non QOS */
1018 	rx->fc = fc &= ~IEEE80211_STYPE_QOS_DATA;
1019 	hdr->frame_control = cpu_to_le16(fc);
1020 
1021 	return TXRX_CONTINUE;
1022 }
1023 
1024 static int
1025 ieee80211_802_1x_port_control(struct ieee80211_txrx_data *rx)
1026 {
1027 	if (unlikely(rx->sdata->ieee802_1x_pac &&
1028 		     (!rx->sta || !(rx->sta->flags & WLAN_STA_AUTHORIZED)))) {
1029 #ifdef CONFIG_MAC80211_DEBUG
1030 		printk(KERN_DEBUG "%s: dropped frame "
1031 		       "(unauthorized port)\n", rx->dev->name);
1032 #endif /* CONFIG_MAC80211_DEBUG */
1033 		return -EACCES;
1034 	}
1035 
1036 	return 0;
1037 }
1038 
1039 static int
1040 ieee80211_drop_unencrypted(struct ieee80211_txrx_data *rx)
1041 {
1042 	/*
1043 	 * Pass through unencrypted frames if the hardware has
1044 	 * decrypted them already.
1045 	 */
1046 	if (rx->u.rx.status->flag & RX_FLAG_DECRYPTED)
1047 		return 0;
1048 
1049 	/* Drop unencrypted frames if key is set. */
1050 	if (unlikely(!(rx->fc & IEEE80211_FCTL_PROTECTED) &&
1051 		     (rx->fc & IEEE80211_FCTL_FTYPE) == IEEE80211_FTYPE_DATA &&
1052 		     (rx->fc & IEEE80211_FCTL_STYPE) != IEEE80211_STYPE_NULLFUNC &&
1053 		     (rx->key || rx->sdata->drop_unencrypted))) {
1054 		if (net_ratelimit())
1055 			printk(KERN_DEBUG "%s: RX non-WEP frame, but expected "
1056 			       "encryption\n", rx->dev->name);
1057 		return -EACCES;
1058 	}
1059 	return 0;
1060 }
1061 
1062 static int
1063 ieee80211_data_to_8023(struct ieee80211_txrx_data *rx)
1064 {
1065 	struct net_device *dev = rx->dev;
1066 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) rx->skb->data;
1067 	u16 fc, hdrlen, ethertype;
1068 	u8 *payload;
1069 	u8 dst[ETH_ALEN];
1070 	u8 src[ETH_ALEN];
1071 	struct sk_buff *skb = rx->skb;
1072 	struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
1073 	DECLARE_MAC_BUF(mac);
1074 	DECLARE_MAC_BUF(mac2);
1075 	DECLARE_MAC_BUF(mac3);
1076 	DECLARE_MAC_BUF(mac4);
1077 
1078 	fc = rx->fc;
1079 
1080 	if (unlikely(!WLAN_FC_DATA_PRESENT(fc)))
1081 		return -1;
1082 
1083 	hdrlen = ieee80211_get_hdrlen(fc);
1084 
1085 	/* convert IEEE 802.11 header + possible LLC headers into Ethernet
1086 	 * header
1087 	 * IEEE 802.11 address fields:
1088 	 * ToDS FromDS Addr1 Addr2 Addr3 Addr4
1089 	 *   0     0   DA    SA    BSSID n/a
1090 	 *   0     1   DA    BSSID SA    n/a
1091 	 *   1     0   BSSID SA    DA    n/a
1092 	 *   1     1   RA    TA    DA    SA
1093 	 */
1094 
1095 	switch (fc & (IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS)) {
1096 	case IEEE80211_FCTL_TODS:
1097 		/* BSSID SA DA */
1098 		memcpy(dst, hdr->addr3, ETH_ALEN);
1099 		memcpy(src, hdr->addr2, ETH_ALEN);
1100 
1101 		if (unlikely(sdata->vif.type != IEEE80211_IF_TYPE_AP &&
1102 			     sdata->vif.type != IEEE80211_IF_TYPE_VLAN)) {
1103 			if (net_ratelimit())
1104 				printk(KERN_DEBUG "%s: dropped ToDS frame "
1105 				       "(BSSID=%s SA=%s DA=%s)\n",
1106 				       dev->name,
1107 				       print_mac(mac, hdr->addr1),
1108 				       print_mac(mac2, hdr->addr2),
1109 				       print_mac(mac3, hdr->addr3));
1110 			return -1;
1111 		}
1112 		break;
1113 	case (IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS):
1114 		/* RA TA DA SA */
1115 		memcpy(dst, hdr->addr3, ETH_ALEN);
1116 		memcpy(src, hdr->addr4, ETH_ALEN);
1117 
1118 		if (unlikely(sdata->vif.type != IEEE80211_IF_TYPE_WDS)) {
1119 			if (net_ratelimit())
1120 				printk(KERN_DEBUG "%s: dropped FromDS&ToDS "
1121 				       "frame (RA=%s TA=%s DA=%s SA=%s)\n",
1122 				       rx->dev->name,
1123 				       print_mac(mac, hdr->addr1),
1124 				       print_mac(mac2, hdr->addr2),
1125 				       print_mac(mac3, hdr->addr3),
1126 				       print_mac(mac4, hdr->addr4));
1127 			return -1;
1128 		}
1129 		break;
1130 	case IEEE80211_FCTL_FROMDS:
1131 		/* DA BSSID SA */
1132 		memcpy(dst, hdr->addr1, ETH_ALEN);
1133 		memcpy(src, hdr->addr3, ETH_ALEN);
1134 
1135 		if (sdata->vif.type != IEEE80211_IF_TYPE_STA ||
1136 		    (is_multicast_ether_addr(dst) &&
1137 		     !compare_ether_addr(src, dev->dev_addr)))
1138 			return -1;
1139 		break;
1140 	case 0:
1141 		/* DA SA BSSID */
1142 		memcpy(dst, hdr->addr1, ETH_ALEN);
1143 		memcpy(src, hdr->addr2, ETH_ALEN);
1144 
1145 		if (sdata->vif.type != IEEE80211_IF_TYPE_IBSS) {
1146 			if (net_ratelimit()) {
1147 				printk(KERN_DEBUG "%s: dropped IBSS frame "
1148 				       "(DA=%s SA=%s BSSID=%s)\n",
1149 				       dev->name,
1150 				       print_mac(mac, hdr->addr1),
1151 				       print_mac(mac2, hdr->addr2),
1152 				       print_mac(mac3, hdr->addr3));
1153 			}
1154 			return -1;
1155 		}
1156 		break;
1157 	}
1158 
1159 	if (unlikely(skb->len - hdrlen < 8)) {
1160 		if (net_ratelimit()) {
1161 			printk(KERN_DEBUG "%s: RX too short data frame "
1162 			       "payload\n", dev->name);
1163 		}
1164 		return -1;
1165 	}
1166 
1167 	payload = skb->data + hdrlen;
1168 	ethertype = (payload[6] << 8) | payload[7];
1169 
1170 	if (likely((compare_ether_addr(payload, rfc1042_header) == 0 &&
1171 		    ethertype != ETH_P_AARP && ethertype != ETH_P_IPX) ||
1172 		   compare_ether_addr(payload, bridge_tunnel_header) == 0)) {
1173 		/* remove RFC1042 or Bridge-Tunnel encapsulation and
1174 		 * replace EtherType */
1175 		skb_pull(skb, hdrlen + 6);
1176 		memcpy(skb_push(skb, ETH_ALEN), src, ETH_ALEN);
1177 		memcpy(skb_push(skb, ETH_ALEN), dst, ETH_ALEN);
1178 	} else {
1179 		struct ethhdr *ehdr;
1180 		__be16 len;
1181 
1182 		skb_pull(skb, hdrlen);
1183 		len = htons(skb->len);
1184 		ehdr = (struct ethhdr *) skb_push(skb, sizeof(struct ethhdr));
1185 		memcpy(ehdr->h_dest, dst, ETH_ALEN);
1186 		memcpy(ehdr->h_source, src, ETH_ALEN);
1187 		ehdr->h_proto = len;
1188 	}
1189 	return 0;
1190 }
1191 
1192 /*
1193  * requires that rx->skb is a frame with ethernet header
1194  */
1195 static bool ieee80211_frame_allowed(struct ieee80211_txrx_data *rx)
1196 {
1197 	static const u8 pae_group_addr[ETH_ALEN]
1198 		= { 0x01, 0x80, 0xC2, 0x00, 0x00, 0x03 };
1199 	struct ethhdr *ehdr = (struct ethhdr *) rx->skb->data;
1200 
1201 	/*
1202 	 * Allow EAPOL frames to us/the PAE group address regardless
1203 	 * of whether the frame was encrypted or not.
1204 	 */
1205 	if (ehdr->h_proto == htons(ETH_P_PAE) &&
1206 	    (compare_ether_addr(ehdr->h_dest, rx->dev->dev_addr) == 0 ||
1207 	     compare_ether_addr(ehdr->h_dest, pae_group_addr) == 0))
1208 		return true;
1209 
1210 	if (ieee80211_802_1x_port_control(rx) ||
1211 	    ieee80211_drop_unencrypted(rx))
1212 		return false;
1213 
1214 	return true;
1215 }
1216 
1217 /*
1218  * requires that rx->skb is a frame with ethernet header
1219  */
1220 static void
1221 ieee80211_deliver_skb(struct ieee80211_txrx_data *rx)
1222 {
1223 	struct net_device *dev = rx->dev;
1224 	struct ieee80211_local *local = rx->local;
1225 	struct sk_buff *skb, *xmit_skb;
1226 	struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
1227 	struct ethhdr *ehdr = (struct ethhdr *) rx->skb->data;
1228 	struct sta_info *dsta;
1229 
1230 	skb = rx->skb;
1231 	xmit_skb = NULL;
1232 
1233 	if (local->bridge_packets && (sdata->vif.type == IEEE80211_IF_TYPE_AP ||
1234 				      sdata->vif.type == IEEE80211_IF_TYPE_VLAN) &&
1235 	    (rx->flags & IEEE80211_TXRXD_RXRA_MATCH)) {
1236 		if (is_multicast_ether_addr(ehdr->h_dest)) {
1237 			/*
1238 			 * send multicast frames both to higher layers in
1239 			 * local net stack and back to the wireless medium
1240 			 */
1241 			xmit_skb = skb_copy(skb, GFP_ATOMIC);
1242 			if (!xmit_skb && net_ratelimit())
1243 				printk(KERN_DEBUG "%s: failed to clone "
1244 				       "multicast frame\n", dev->name);
1245 		} else {
1246 			dsta = sta_info_get(local, skb->data);
1247 			if (dsta && dsta->dev == dev) {
1248 				/*
1249 				 * The destination station is associated to
1250 				 * this AP (in this VLAN), so send the frame
1251 				 * directly to it and do not pass it to local
1252 				 * net stack.
1253 				 */
1254 				xmit_skb = skb;
1255 				skb = NULL;
1256 			}
1257 			if (dsta)
1258 				sta_info_put(dsta);
1259 		}
1260 	}
1261 
1262 	if (skb) {
1263 		/* deliver to local stack */
1264 		skb->protocol = eth_type_trans(skb, dev);
1265 		memset(skb->cb, 0, sizeof(skb->cb));
1266 		netif_rx(skb);
1267 	}
1268 
1269 	if (xmit_skb) {
1270 		/* send to wireless media */
1271 		xmit_skb->protocol = htons(ETH_P_802_3);
1272 		skb_reset_network_header(xmit_skb);
1273 		skb_reset_mac_header(xmit_skb);
1274 		dev_queue_xmit(xmit_skb);
1275 	}
1276 }
1277 
1278 static ieee80211_txrx_result
1279 ieee80211_rx_h_amsdu(struct ieee80211_txrx_data *rx)
1280 {
1281 	struct net_device *dev = rx->dev;
1282 	struct ieee80211_local *local = rx->local;
1283 	u16 fc, ethertype;
1284 	u8 *payload;
1285 	struct sk_buff *skb = rx->skb, *frame = NULL;
1286 	const struct ethhdr *eth;
1287 	int remaining, err;
1288 	u8 dst[ETH_ALEN];
1289 	u8 src[ETH_ALEN];
1290 	DECLARE_MAC_BUF(mac);
1291 
1292 	fc = rx->fc;
1293 	if (unlikely((fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_DATA))
1294 		return TXRX_CONTINUE;
1295 
1296 	if (unlikely(!WLAN_FC_DATA_PRESENT(fc)))
1297 		return TXRX_DROP;
1298 
1299 	if (!(rx->flags & IEEE80211_TXRXD_RX_AMSDU))
1300 		return TXRX_CONTINUE;
1301 
1302 	err = ieee80211_data_to_8023(rx);
1303 	if (unlikely(err))
1304 		return TXRX_DROP;
1305 
1306 	skb->dev = dev;
1307 
1308 	dev->stats.rx_packets++;
1309 	dev->stats.rx_bytes += skb->len;
1310 
1311 	/* skip the wrapping header */
1312 	eth = (struct ethhdr *) skb_pull(skb, sizeof(struct ethhdr));
1313 	if (!eth)
1314 		return TXRX_DROP;
1315 
1316 	while (skb != frame) {
1317 		u8 padding;
1318 		__be16 len = eth->h_proto;
1319 		unsigned int subframe_len = sizeof(struct ethhdr) + ntohs(len);
1320 
1321 		remaining = skb->len;
1322 		memcpy(dst, eth->h_dest, ETH_ALEN);
1323 		memcpy(src, eth->h_source, ETH_ALEN);
1324 
1325 		padding = ((4 - subframe_len) & 0x3);
1326 		/* the last MSDU has no padding */
1327 		if (subframe_len > remaining) {
1328 			printk(KERN_DEBUG "%s: wrong buffer size", dev->name);
1329 			return TXRX_DROP;
1330 		}
1331 
1332 		skb_pull(skb, sizeof(struct ethhdr));
1333 		/* if last subframe reuse skb */
1334 		if (remaining <= subframe_len + padding)
1335 			frame = skb;
1336 		else {
1337 			frame = dev_alloc_skb(local->hw.extra_tx_headroom +
1338 					      subframe_len);
1339 
1340 			if (frame == NULL)
1341 				return TXRX_DROP;
1342 
1343 			skb_reserve(frame, local->hw.extra_tx_headroom +
1344 				    sizeof(struct ethhdr));
1345 			memcpy(skb_put(frame, ntohs(len)), skb->data,
1346 				ntohs(len));
1347 
1348 			eth = (struct ethhdr *) skb_pull(skb, ntohs(len) +
1349 							padding);
1350 			if (!eth) {
1351 				printk(KERN_DEBUG "%s: wrong buffer size ",
1352 				       dev->name);
1353 				dev_kfree_skb(frame);
1354 				return TXRX_DROP;
1355 			}
1356 		}
1357 
1358 		skb_reset_network_header(frame);
1359 		frame->dev = dev;
1360 		frame->priority = skb->priority;
1361 		rx->skb = frame;
1362 
1363 		payload = frame->data;
1364 		ethertype = (payload[6] << 8) | payload[7];
1365 
1366 		if (likely((compare_ether_addr(payload, rfc1042_header) == 0 &&
1367 			    ethertype != ETH_P_AARP && ethertype != ETH_P_IPX) ||
1368 			   compare_ether_addr(payload,
1369 					      bridge_tunnel_header) == 0)) {
1370 			/* remove RFC1042 or Bridge-Tunnel
1371 			 * encapsulation and replace EtherType */
1372 			skb_pull(frame, 6);
1373 			memcpy(skb_push(frame, ETH_ALEN), src, ETH_ALEN);
1374 			memcpy(skb_push(frame, ETH_ALEN), dst, ETH_ALEN);
1375 		} else {
1376 			memcpy(skb_push(frame, sizeof(__be16)),
1377 			       &len, sizeof(__be16));
1378 			memcpy(skb_push(frame, ETH_ALEN), src, ETH_ALEN);
1379 			memcpy(skb_push(frame, ETH_ALEN), dst, ETH_ALEN);
1380 		}
1381 
1382 		if (!ieee80211_frame_allowed(rx)) {
1383 			if (skb == frame) /* last frame */
1384 				return TXRX_DROP;
1385 			dev_kfree_skb(frame);
1386 			continue;
1387 		}
1388 
1389 		ieee80211_deliver_skb(rx);
1390 	}
1391 
1392 	return TXRX_QUEUED;
1393 }
1394 
1395 static ieee80211_txrx_result
1396 ieee80211_rx_h_data(struct ieee80211_txrx_data *rx)
1397 {
1398 	struct net_device *dev = rx->dev;
1399 	u16 fc;
1400 	int err;
1401 
1402 	fc = rx->fc;
1403 	if (unlikely((fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_DATA))
1404 		return TXRX_CONTINUE;
1405 
1406 	if (unlikely(!WLAN_FC_DATA_PRESENT(fc)))
1407 		return TXRX_DROP;
1408 
1409 	err = ieee80211_data_to_8023(rx);
1410 	if (unlikely(err))
1411 		return TXRX_DROP;
1412 
1413 	if (!ieee80211_frame_allowed(rx))
1414 		return TXRX_DROP;
1415 
1416 	rx->skb->dev = dev;
1417 
1418 	dev->stats.rx_packets++;
1419 	dev->stats.rx_bytes += rx->skb->len;
1420 
1421 	ieee80211_deliver_skb(rx);
1422 
1423 	return TXRX_QUEUED;
1424 }
1425 
1426 static ieee80211_txrx_result
1427 ieee80211_rx_h_ctrl(struct ieee80211_txrx_data *rx)
1428 {
1429 	struct ieee80211_local *local = rx->local;
1430 	struct ieee80211_hw *hw = &local->hw;
1431 	struct sk_buff *skb = rx->skb;
1432 	struct ieee80211_bar *bar = (struct ieee80211_bar *) skb->data;
1433 	struct tid_ampdu_rx *tid_agg_rx;
1434 	u16 start_seq_num;
1435 	u16 tid;
1436 
1437 	if (likely((rx->fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_CTL))
1438 		return TXRX_CONTINUE;
1439 
1440 	if ((rx->fc & IEEE80211_FCTL_STYPE) == IEEE80211_STYPE_BACK_REQ) {
1441 		if (!rx->sta)
1442 			return TXRX_CONTINUE;
1443 		tid = le16_to_cpu(bar->control) >> 12;
1444 		tid_agg_rx = &(rx->sta->ampdu_mlme.tid_rx[tid]);
1445 		if (tid_agg_rx->state != HT_AGG_STATE_OPERATIONAL)
1446 			return TXRX_CONTINUE;
1447 
1448 		start_seq_num = le16_to_cpu(bar->start_seq_num) >> 4;
1449 
1450 		/* reset session timer */
1451 		if (tid_agg_rx->timeout) {
1452 			unsigned long expires =
1453 				jiffies + (tid_agg_rx->timeout / 1000) * HZ;
1454 			mod_timer(&tid_agg_rx->session_timer, expires);
1455 		}
1456 
1457 		/* manage reordering buffer according to requested */
1458 		/* sequence number */
1459 		rcu_read_lock();
1460 		ieee80211_sta_manage_reorder_buf(hw, tid_agg_rx, NULL,
1461 						 start_seq_num, 1);
1462 		rcu_read_unlock();
1463 		return TXRX_DROP;
1464 	}
1465 
1466 	return TXRX_CONTINUE;
1467 }
1468 
1469 static ieee80211_txrx_result
1470 ieee80211_rx_h_mgmt(struct ieee80211_txrx_data *rx)
1471 {
1472 	struct ieee80211_sub_if_data *sdata;
1473 
1474 	if (!(rx->flags & IEEE80211_TXRXD_RXRA_MATCH))
1475 		return TXRX_DROP;
1476 
1477 	sdata = IEEE80211_DEV_TO_SUB_IF(rx->dev);
1478 	if ((sdata->vif.type == IEEE80211_IF_TYPE_STA ||
1479 	     sdata->vif.type == IEEE80211_IF_TYPE_IBSS) &&
1480 	    !(sdata->flags & IEEE80211_SDATA_USERSPACE_MLME))
1481 		ieee80211_sta_rx_mgmt(rx->dev, rx->skb, rx->u.rx.status);
1482 	else
1483 		return TXRX_DROP;
1484 
1485 	return TXRX_QUEUED;
1486 }
1487 
1488 static inline ieee80211_txrx_result __ieee80211_invoke_rx_handlers(
1489 				struct ieee80211_local *local,
1490 				ieee80211_rx_handler *handlers,
1491 				struct ieee80211_txrx_data *rx,
1492 				struct sta_info *sta)
1493 {
1494 	ieee80211_rx_handler *handler;
1495 	ieee80211_txrx_result res = TXRX_DROP;
1496 
1497 	for (handler = handlers; *handler != NULL; handler++) {
1498 		res = (*handler)(rx);
1499 
1500 		switch (res) {
1501 		case TXRX_CONTINUE:
1502 			continue;
1503 		case TXRX_DROP:
1504 			I802_DEBUG_INC(local->rx_handlers_drop);
1505 			if (sta)
1506 				sta->rx_dropped++;
1507 			break;
1508 		case TXRX_QUEUED:
1509 			I802_DEBUG_INC(local->rx_handlers_queued);
1510 			break;
1511 		}
1512 		break;
1513 	}
1514 
1515 	if (res == TXRX_DROP)
1516 		dev_kfree_skb(rx->skb);
1517 	return res;
1518 }
1519 
1520 static inline void ieee80211_invoke_rx_handlers(struct ieee80211_local *local,
1521 						ieee80211_rx_handler *handlers,
1522 						struct ieee80211_txrx_data *rx,
1523 						struct sta_info *sta)
1524 {
1525 	if (__ieee80211_invoke_rx_handlers(local, handlers, rx, sta) ==
1526 	    TXRX_CONTINUE)
1527 		dev_kfree_skb(rx->skb);
1528 }
1529 
1530 static void ieee80211_rx_michael_mic_report(struct net_device *dev,
1531 					    struct ieee80211_hdr *hdr,
1532 					    struct sta_info *sta,
1533 					    struct ieee80211_txrx_data *rx)
1534 {
1535 	int keyidx, hdrlen;
1536 	DECLARE_MAC_BUF(mac);
1537 	DECLARE_MAC_BUF(mac2);
1538 
1539 	hdrlen = ieee80211_get_hdrlen_from_skb(rx->skb);
1540 	if (rx->skb->len >= hdrlen + 4)
1541 		keyidx = rx->skb->data[hdrlen + 3] >> 6;
1542 	else
1543 		keyidx = -1;
1544 
1545 	if (net_ratelimit())
1546 		printk(KERN_DEBUG "%s: TKIP hwaccel reported Michael MIC "
1547 		       "failure from %s to %s keyidx=%d\n",
1548 		       dev->name, print_mac(mac, hdr->addr2),
1549 		       print_mac(mac2, hdr->addr1), keyidx);
1550 
1551 	if (!sta) {
1552 		/*
1553 		 * Some hardware seem to generate incorrect Michael MIC
1554 		 * reports; ignore them to avoid triggering countermeasures.
1555 		 */
1556 		if (net_ratelimit())
1557 			printk(KERN_DEBUG "%s: ignored spurious Michael MIC "
1558 			       "error for unknown address %s\n",
1559 			       dev->name, print_mac(mac, hdr->addr2));
1560 		goto ignore;
1561 	}
1562 
1563 	if (!(rx->fc & IEEE80211_FCTL_PROTECTED)) {
1564 		if (net_ratelimit())
1565 			printk(KERN_DEBUG "%s: ignored spurious Michael MIC "
1566 			       "error for a frame with no PROTECTED flag (src "
1567 			       "%s)\n", dev->name, print_mac(mac, hdr->addr2));
1568 		goto ignore;
1569 	}
1570 
1571 	if (rx->sdata->vif.type == IEEE80211_IF_TYPE_AP && keyidx) {
1572 		/*
1573 		 * APs with pairwise keys should never receive Michael MIC
1574 		 * errors for non-zero keyidx because these are reserved for
1575 		 * group keys and only the AP is sending real multicast
1576 		 * frames in the BSS.
1577 		 */
1578 		if (net_ratelimit())
1579 			printk(KERN_DEBUG "%s: ignored Michael MIC error for "
1580 			       "a frame with non-zero keyidx (%d)"
1581 			       " (src %s)\n", dev->name, keyidx,
1582 			       print_mac(mac, hdr->addr2));
1583 		goto ignore;
1584 	}
1585 
1586 	if ((rx->fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_DATA &&
1587 	    ((rx->fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_MGMT ||
1588 	     (rx->fc & IEEE80211_FCTL_STYPE) != IEEE80211_STYPE_AUTH)) {
1589 		if (net_ratelimit())
1590 			printk(KERN_DEBUG "%s: ignored spurious Michael MIC "
1591 			       "error for a frame that cannot be encrypted "
1592 			       "(fc=0x%04x) (src %s)\n",
1593 			       dev->name, rx->fc, print_mac(mac, hdr->addr2));
1594 		goto ignore;
1595 	}
1596 
1597 	mac80211_ev_michael_mic_failure(rx->dev, keyidx, hdr);
1598  ignore:
1599 	dev_kfree_skb(rx->skb);
1600 	rx->skb = NULL;
1601 }
1602 
1603 ieee80211_rx_handler ieee80211_rx_handlers[] =
1604 {
1605 	ieee80211_rx_h_if_stats,
1606 	ieee80211_rx_h_passive_scan,
1607 	ieee80211_rx_h_check,
1608 	ieee80211_rx_h_decrypt,
1609 	ieee80211_rx_h_sta_process,
1610 	ieee80211_rx_h_defragment,
1611 	ieee80211_rx_h_ps_poll,
1612 	ieee80211_rx_h_michael_mic_verify,
1613 	/* this must be after decryption - so header is counted in MPDU mic
1614 	 * must be before pae and data, so QOS_DATA format frames
1615 	 * are not passed to user space by these functions
1616 	 */
1617 	ieee80211_rx_h_remove_qos_control,
1618 	ieee80211_rx_h_amsdu,
1619 	ieee80211_rx_h_data,
1620 	ieee80211_rx_h_ctrl,
1621 	ieee80211_rx_h_mgmt,
1622 	NULL
1623 };
1624 
1625 /* main receive path */
1626 
1627 static int prepare_for_handlers(struct ieee80211_sub_if_data *sdata,
1628 				u8 *bssid, struct ieee80211_txrx_data *rx,
1629 				struct ieee80211_hdr *hdr)
1630 {
1631 	int multicast = is_multicast_ether_addr(hdr->addr1);
1632 
1633 	switch (sdata->vif.type) {
1634 	case IEEE80211_IF_TYPE_STA:
1635 		if (!bssid)
1636 			return 0;
1637 		if (!ieee80211_bssid_match(bssid, sdata->u.sta.bssid)) {
1638 			if (!(rx->flags & IEEE80211_TXRXD_RXIN_SCAN))
1639 				return 0;
1640 			rx->flags &= ~IEEE80211_TXRXD_RXRA_MATCH;
1641 		} else if (!multicast &&
1642 			   compare_ether_addr(sdata->dev->dev_addr,
1643 					      hdr->addr1) != 0) {
1644 			if (!(sdata->dev->flags & IFF_PROMISC))
1645 				return 0;
1646 			rx->flags &= ~IEEE80211_TXRXD_RXRA_MATCH;
1647 		}
1648 		break;
1649 	case IEEE80211_IF_TYPE_IBSS:
1650 		if (!bssid)
1651 			return 0;
1652 		if (!ieee80211_bssid_match(bssid, sdata->u.sta.bssid)) {
1653 			if (!(rx->flags & IEEE80211_TXRXD_RXIN_SCAN))
1654 				return 0;
1655 			rx->flags &= ~IEEE80211_TXRXD_RXRA_MATCH;
1656 		} else if (!multicast &&
1657 			   compare_ether_addr(sdata->dev->dev_addr,
1658 					      hdr->addr1) != 0) {
1659 			if (!(sdata->dev->flags & IFF_PROMISC))
1660 				return 0;
1661 			rx->flags &= ~IEEE80211_TXRXD_RXRA_MATCH;
1662 		} else if (!rx->sta)
1663 			rx->sta = ieee80211_ibss_add_sta(sdata->dev, rx->skb,
1664 							 bssid, hdr->addr2);
1665 		break;
1666 	case IEEE80211_IF_TYPE_VLAN:
1667 	case IEEE80211_IF_TYPE_AP:
1668 		if (!bssid) {
1669 			if (compare_ether_addr(sdata->dev->dev_addr,
1670 					       hdr->addr1))
1671 				return 0;
1672 		} else if (!ieee80211_bssid_match(bssid,
1673 					sdata->dev->dev_addr)) {
1674 			if (!(rx->flags & IEEE80211_TXRXD_RXIN_SCAN))
1675 				return 0;
1676 			rx->flags &= ~IEEE80211_TXRXD_RXRA_MATCH;
1677 		}
1678 		if (sdata->dev == sdata->local->mdev &&
1679 		    !(rx->flags & IEEE80211_TXRXD_RXIN_SCAN))
1680 			/* do not receive anything via
1681 			 * master device when not scanning */
1682 			return 0;
1683 		break;
1684 	case IEEE80211_IF_TYPE_WDS:
1685 		if (bssid ||
1686 		    (rx->fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_DATA)
1687 			return 0;
1688 		if (compare_ether_addr(sdata->u.wds.remote_addr, hdr->addr2))
1689 			return 0;
1690 		break;
1691 	case IEEE80211_IF_TYPE_MNTR:
1692 		/* take everything */
1693 		break;
1694 	case IEEE80211_IF_TYPE_INVALID:
1695 		/* should never get here */
1696 		WARN_ON(1);
1697 		break;
1698 	}
1699 
1700 	return 1;
1701 }
1702 
1703 /*
1704  * This is the actual Rx frames handler. as it blongs to Rx path it must
1705  * be called with rcu_read_lock protection.
1706  */
1707 static void __ieee80211_rx_handle_packet(struct ieee80211_hw *hw,
1708 					 struct sk_buff *skb,
1709 					 struct ieee80211_rx_status *status,
1710 					 u32 load)
1711 {
1712 	struct ieee80211_local *local = hw_to_local(hw);
1713 	struct ieee80211_sub_if_data *sdata;
1714 	struct sta_info *sta;
1715 	struct ieee80211_hdr *hdr;
1716 	struct ieee80211_txrx_data rx;
1717 	u16 type;
1718 	int prepares;
1719 	struct ieee80211_sub_if_data *prev = NULL;
1720 	struct sk_buff *skb_new;
1721 	u8 *bssid;
1722 
1723 	hdr = (struct ieee80211_hdr *) skb->data;
1724 	memset(&rx, 0, sizeof(rx));
1725 	rx.skb = skb;
1726 	rx.local = local;
1727 
1728 	rx.u.rx.status = status;
1729 	rx.u.rx.load = load;
1730 	rx.fc = le16_to_cpu(hdr->frame_control);
1731 	type = rx.fc & IEEE80211_FCTL_FTYPE;
1732 
1733 	if (type == IEEE80211_FTYPE_DATA || type == IEEE80211_FTYPE_MGMT)
1734 		local->dot11ReceivedFragmentCount++;
1735 
1736 	sta = rx.sta = sta_info_get(local, hdr->addr2);
1737 	if (sta) {
1738 		rx.dev = rx.sta->dev;
1739 		rx.sdata = IEEE80211_DEV_TO_SUB_IF(rx.dev);
1740 	}
1741 
1742 	if ((status->flag & RX_FLAG_MMIC_ERROR)) {
1743 		ieee80211_rx_michael_mic_report(local->mdev, hdr, sta, &rx);
1744 		goto end;
1745 	}
1746 
1747 	if (unlikely(local->sta_sw_scanning || local->sta_hw_scanning))
1748 		rx.flags |= IEEE80211_TXRXD_RXIN_SCAN;
1749 
1750 	if (__ieee80211_invoke_rx_handlers(local, local->rx_pre_handlers, &rx,
1751 					   sta) != TXRX_CONTINUE)
1752 		goto end;
1753 	skb = rx.skb;
1754 
1755 	if (sta && !(sta->flags & (WLAN_STA_WDS | WLAN_STA_ASSOC_AP)) &&
1756 	    !atomic_read(&local->iff_promiscs) &&
1757 	    !is_multicast_ether_addr(hdr->addr1)) {
1758 		rx.flags |= IEEE80211_TXRXD_RXRA_MATCH;
1759 		ieee80211_invoke_rx_handlers(local, local->rx_handlers, &rx,
1760 					     rx.sta);
1761 		sta_info_put(sta);
1762 		return;
1763 	}
1764 
1765 	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
1766 		if (!netif_running(sdata->dev))
1767 			continue;
1768 
1769 		if (sdata->vif.type == IEEE80211_IF_TYPE_MNTR)
1770 			continue;
1771 
1772 		bssid = ieee80211_get_bssid(hdr, skb->len, sdata->vif.type);
1773 		rx.flags |= IEEE80211_TXRXD_RXRA_MATCH;
1774 		prepares = prepare_for_handlers(sdata, bssid, &rx, hdr);
1775 		/* prepare_for_handlers can change sta */
1776 		sta = rx.sta;
1777 
1778 		if (!prepares)
1779 			continue;
1780 
1781 		/*
1782 		 * frame is destined for this interface, but if it's not
1783 		 * also for the previous one we handle that after the
1784 		 * loop to avoid copying the SKB once too much
1785 		 */
1786 
1787 		if (!prev) {
1788 			prev = sdata;
1789 			continue;
1790 		}
1791 
1792 		/*
1793 		 * frame was destined for the previous interface
1794 		 * so invoke RX handlers for it
1795 		 */
1796 
1797 		skb_new = skb_copy(skb, GFP_ATOMIC);
1798 		if (!skb_new) {
1799 			if (net_ratelimit())
1800 				printk(KERN_DEBUG "%s: failed to copy "
1801 				       "multicast frame for %s",
1802 				       wiphy_name(local->hw.wiphy),
1803 				       prev->dev->name);
1804 			continue;
1805 		}
1806 		rx.fc = le16_to_cpu(hdr->frame_control);
1807 		rx.skb = skb_new;
1808 		rx.dev = prev->dev;
1809 		rx.sdata = prev;
1810 		ieee80211_invoke_rx_handlers(local, local->rx_handlers,
1811 					     &rx, sta);
1812 		prev = sdata;
1813 	}
1814 	if (prev) {
1815 		rx.fc = le16_to_cpu(hdr->frame_control);
1816 		rx.skb = skb;
1817 		rx.dev = prev->dev;
1818 		rx.sdata = prev;
1819 		ieee80211_invoke_rx_handlers(local, local->rx_handlers,
1820 					     &rx, sta);
1821 	} else
1822 		dev_kfree_skb(skb);
1823 
1824  end:
1825 	if (sta)
1826 		sta_info_put(sta);
1827 }
1828 
1829 #define SEQ_MODULO 0x1000
1830 #define SEQ_MASK   0xfff
1831 
1832 static inline int seq_less(u16 sq1, u16 sq2)
1833 {
1834 	return (((sq1 - sq2) & SEQ_MASK) > (SEQ_MODULO >> 1));
1835 }
1836 
1837 static inline u16 seq_inc(u16 sq)
1838 {
1839 	return ((sq + 1) & SEQ_MASK);
1840 }
1841 
1842 static inline u16 seq_sub(u16 sq1, u16 sq2)
1843 {
1844 	return ((sq1 - sq2) & SEQ_MASK);
1845 }
1846 
1847 
1848 /*
1849  * As it function blongs to Rx path it must be called with
1850  * the proper rcu_read_lock protection for its flow.
1851  */
1852 u8 ieee80211_sta_manage_reorder_buf(struct ieee80211_hw *hw,
1853 				struct tid_ampdu_rx *tid_agg_rx,
1854 				struct sk_buff *skb, u16 mpdu_seq_num,
1855 				int bar_req)
1856 {
1857 	struct ieee80211_local *local = hw_to_local(hw);
1858 	struct ieee80211_rx_status status;
1859 	u16 head_seq_num, buf_size;
1860 	int index;
1861 	u32 pkt_load;
1862 
1863 	buf_size = tid_agg_rx->buf_size;
1864 	head_seq_num = tid_agg_rx->head_seq_num;
1865 
1866 	/* frame with out of date sequence number */
1867 	if (seq_less(mpdu_seq_num, head_seq_num)) {
1868 		dev_kfree_skb(skb);
1869 		return 1;
1870 	}
1871 
1872 	/* if frame sequence number exceeds our buffering window size or
1873 	 * block Ack Request arrived - release stored frames */
1874 	if ((!seq_less(mpdu_seq_num, head_seq_num + buf_size)) || (bar_req)) {
1875 		/* new head to the ordering buffer */
1876 		if (bar_req)
1877 			head_seq_num = mpdu_seq_num;
1878 		else
1879 			head_seq_num =
1880 				seq_inc(seq_sub(mpdu_seq_num, buf_size));
1881 		/* release stored frames up to new head to stack */
1882 		while (seq_less(tid_agg_rx->head_seq_num, head_seq_num)) {
1883 			index = seq_sub(tid_agg_rx->head_seq_num,
1884 				tid_agg_rx->ssn)
1885 				% tid_agg_rx->buf_size;
1886 
1887 			if (tid_agg_rx->reorder_buf[index]) {
1888 				/* release the reordered frames to stack */
1889 				memcpy(&status,
1890 					tid_agg_rx->reorder_buf[index]->cb,
1891 					sizeof(status));
1892 				pkt_load = ieee80211_rx_load_stats(local,
1893 						tid_agg_rx->reorder_buf[index],
1894 						&status);
1895 				__ieee80211_rx_handle_packet(hw,
1896 					tid_agg_rx->reorder_buf[index],
1897 					&status, pkt_load);
1898 				tid_agg_rx->stored_mpdu_num--;
1899 				tid_agg_rx->reorder_buf[index] = NULL;
1900 			}
1901 			tid_agg_rx->head_seq_num =
1902 				seq_inc(tid_agg_rx->head_seq_num);
1903 		}
1904 		if (bar_req)
1905 			return 1;
1906 	}
1907 
1908 	/* now the new frame is always in the range of the reordering */
1909 	/* buffer window */
1910 	index = seq_sub(mpdu_seq_num, tid_agg_rx->ssn)
1911 				% tid_agg_rx->buf_size;
1912 	/* check if we already stored this frame */
1913 	if (tid_agg_rx->reorder_buf[index]) {
1914 		dev_kfree_skb(skb);
1915 		return 1;
1916 	}
1917 
1918 	/* if arrived mpdu is in the right order and nothing else stored */
1919 	/* release it immediately */
1920 	if (mpdu_seq_num == tid_agg_rx->head_seq_num &&
1921 			tid_agg_rx->stored_mpdu_num == 0) {
1922 		tid_agg_rx->head_seq_num =
1923 			seq_inc(tid_agg_rx->head_seq_num);
1924 		return 0;
1925 	}
1926 
1927 	/* put the frame in the reordering buffer */
1928 	tid_agg_rx->reorder_buf[index] = skb;
1929 	tid_agg_rx->stored_mpdu_num++;
1930 	/* release the buffer until next missing frame */
1931 	index = seq_sub(tid_agg_rx->head_seq_num, tid_agg_rx->ssn)
1932 						% tid_agg_rx->buf_size;
1933 	while (tid_agg_rx->reorder_buf[index]) {
1934 		/* release the reordered frame back to stack */
1935 		memcpy(&status, tid_agg_rx->reorder_buf[index]->cb,
1936 			sizeof(status));
1937 		pkt_load = ieee80211_rx_load_stats(local,
1938 					tid_agg_rx->reorder_buf[index],
1939 					&status);
1940 		__ieee80211_rx_handle_packet(hw, tid_agg_rx->reorder_buf[index],
1941 						&status, pkt_load);
1942 		tid_agg_rx->stored_mpdu_num--;
1943 		tid_agg_rx->reorder_buf[index] = NULL;
1944 		tid_agg_rx->head_seq_num = seq_inc(tid_agg_rx->head_seq_num);
1945 		index =	seq_sub(tid_agg_rx->head_seq_num,
1946 			tid_agg_rx->ssn) % tid_agg_rx->buf_size;
1947 	}
1948 	return 1;
1949 }
1950 
1951 static u8 ieee80211_rx_reorder_ampdu(struct ieee80211_local *local,
1952 				     struct sk_buff *skb)
1953 {
1954 	struct ieee80211_hw *hw = &local->hw;
1955 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
1956 	struct sta_info *sta;
1957 	struct tid_ampdu_rx *tid_agg_rx;
1958 	u16 fc, sc;
1959 	u16 mpdu_seq_num;
1960 	u8 ret = 0, *qc;
1961 	int tid;
1962 
1963 	sta = sta_info_get(local, hdr->addr2);
1964 	if (!sta)
1965 		return ret;
1966 
1967 	fc = le16_to_cpu(hdr->frame_control);
1968 
1969 	/* filter the QoS data rx stream according to
1970 	 * STA/TID and check if this STA/TID is on aggregation */
1971 	if (!WLAN_FC_IS_QOS_DATA(fc))
1972 		goto end_reorder;
1973 
1974 	qc = skb->data + ieee80211_get_hdrlen(fc) - QOS_CONTROL_LEN;
1975 	tid = qc[0] & QOS_CONTROL_TID_MASK;
1976 	tid_agg_rx = &(sta->ampdu_mlme.tid_rx[tid]);
1977 
1978 	if (tid_agg_rx->state != HT_AGG_STATE_OPERATIONAL)
1979 		goto end_reorder;
1980 
1981 	/* null data frames are excluded */
1982 	if (unlikely(fc & IEEE80211_STYPE_NULLFUNC))
1983 		goto end_reorder;
1984 
1985 	/* new un-ordered ampdu frame - process it */
1986 
1987 	/* reset session timer */
1988 	if (tid_agg_rx->timeout) {
1989 		unsigned long expires =
1990 			jiffies + (tid_agg_rx->timeout / 1000) * HZ;
1991 		mod_timer(&tid_agg_rx->session_timer, expires);
1992 	}
1993 
1994 	/* if this mpdu is fragmented - terminate rx aggregation session */
1995 	sc = le16_to_cpu(hdr->seq_ctrl);
1996 	if (sc & IEEE80211_SCTL_FRAG) {
1997 		ieee80211_sta_stop_rx_ba_session(sta->dev, sta->addr,
1998 			tid, 0, WLAN_REASON_QSTA_REQUIRE_SETUP);
1999 		ret = 1;
2000 		goto end_reorder;
2001 	}
2002 
2003 	/* according to mpdu sequence number deal with reordering buffer */
2004 	mpdu_seq_num = (sc & IEEE80211_SCTL_SEQ) >> 4;
2005 	ret = ieee80211_sta_manage_reorder_buf(hw, tid_agg_rx, skb,
2006 						mpdu_seq_num, 0);
2007 end_reorder:
2008 	if (sta)
2009 		sta_info_put(sta);
2010 	return ret;
2011 }
2012 
2013 /*
2014  * This is the receive path handler. It is called by a low level driver when an
2015  * 802.11 MPDU is received from the hardware.
2016  */
2017 void __ieee80211_rx(struct ieee80211_hw *hw, struct sk_buff *skb,
2018 		    struct ieee80211_rx_status *status)
2019 {
2020 	struct ieee80211_local *local = hw_to_local(hw);
2021 	u32 pkt_load;
2022 
2023 	/*
2024 	 * key references and virtual interfaces are protected using RCU
2025 	 * and this requires that we are in a read-side RCU section during
2026 	 * receive processing
2027 	 */
2028 	rcu_read_lock();
2029 
2030 	/*
2031 	 * Frames with failed FCS/PLCP checksum are not returned,
2032 	 * all other frames are returned without radiotap header
2033 	 * if it was previously present.
2034 	 * Also, frames with less than 16 bytes are dropped.
2035 	 */
2036 	skb = ieee80211_rx_monitor(local, skb, status);
2037 	if (!skb) {
2038 		rcu_read_unlock();
2039 		return;
2040 	}
2041 
2042 	pkt_load = ieee80211_rx_load_stats(local, skb, status);
2043 	local->channel_use_raw += pkt_load;
2044 
2045 	if (!ieee80211_rx_reorder_ampdu(local, skb))
2046 		__ieee80211_rx_handle_packet(hw, skb, status, pkt_load);
2047 
2048 	rcu_read_unlock();
2049 }
2050 EXPORT_SYMBOL(__ieee80211_rx);
2051 
2052 /* This is a version of the rx handler that can be called from hard irq
2053  * context. Post the skb on the queue and schedule the tasklet */
2054 void ieee80211_rx_irqsafe(struct ieee80211_hw *hw, struct sk_buff *skb,
2055 			  struct ieee80211_rx_status *status)
2056 {
2057 	struct ieee80211_local *local = hw_to_local(hw);
2058 
2059 	BUILD_BUG_ON(sizeof(struct ieee80211_rx_status) > sizeof(skb->cb));
2060 
2061 	skb->dev = local->mdev;
2062 	/* copy status into skb->cb for use by tasklet */
2063 	memcpy(skb->cb, status, sizeof(*status));
2064 	skb->pkt_type = IEEE80211_RX_MSG;
2065 	skb_queue_tail(&local->skb_queue, skb);
2066 	tasklet_schedule(&local->tasklet);
2067 }
2068 EXPORT_SYMBOL(ieee80211_rx_irqsafe);
2069