xref: /linux/net/mac80211/rx.c (revision b8bb76713ec50df2f11efee386e16f93d51e1076)
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 "led.h"
23 #include "mesh.h"
24 #include "wep.h"
25 #include "wpa.h"
26 #include "tkip.h"
27 #include "wme.h"
28 
29 static u8 ieee80211_sta_manage_reorder_buf(struct ieee80211_hw *hw,
30 					   struct tid_ampdu_rx *tid_agg_rx,
31 					   struct sk_buff *skb,
32 					   u16 mpdu_seq_num,
33 					   int bar_req);
34 /*
35  * monitor mode reception
36  *
37  * This function cleans up the SKB, i.e. it removes all the stuff
38  * only useful for monitoring.
39  */
40 static struct sk_buff *remove_monitor_info(struct ieee80211_local *local,
41 					   struct sk_buff *skb,
42 					   int rtap_len)
43 {
44 	skb_pull(skb, rtap_len);
45 
46 	if (local->hw.flags & IEEE80211_HW_RX_INCLUDES_FCS) {
47 		if (likely(skb->len > FCS_LEN))
48 			skb_trim(skb, skb->len - FCS_LEN);
49 		else {
50 			/* driver bug */
51 			WARN_ON(1);
52 			dev_kfree_skb(skb);
53 			skb = NULL;
54 		}
55 	}
56 
57 	return skb;
58 }
59 
60 static inline int should_drop_frame(struct ieee80211_rx_status *status,
61 				    struct sk_buff *skb,
62 				    int present_fcs_len,
63 				    int radiotap_len)
64 {
65 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
66 
67 	if (status->flag & (RX_FLAG_FAILED_FCS_CRC | RX_FLAG_FAILED_PLCP_CRC))
68 		return 1;
69 	if (unlikely(skb->len < 16 + present_fcs_len + radiotap_len))
70 		return 1;
71 	if (ieee80211_is_ctl(hdr->frame_control) &&
72 	    !ieee80211_is_pspoll(hdr->frame_control) &&
73 	    !ieee80211_is_back_req(hdr->frame_control))
74 		return 1;
75 	return 0;
76 }
77 
78 static int
79 ieee80211_rx_radiotap_len(struct ieee80211_local *local,
80 			  struct ieee80211_rx_status *status)
81 {
82 	int len;
83 
84 	/* always present fields */
85 	len = sizeof(struct ieee80211_radiotap_header) + 9;
86 
87 	if (status->flag & RX_FLAG_TSFT)
88 		len += 8;
89 	if (local->hw.flags & IEEE80211_HW_SIGNAL_DBM)
90 		len += 1;
91 	if (local->hw.flags & IEEE80211_HW_NOISE_DBM)
92 		len += 1;
93 
94 	if (len & 1) /* padding for RX_FLAGS if necessary */
95 		len++;
96 
97 	/* make sure radiotap starts at a naturally aligned address */
98 	if (len % 8)
99 		len = roundup(len, 8);
100 
101 	return len;
102 }
103 
104 /*
105  * ieee80211_add_rx_radiotap_header - add radiotap header
106  *
107  * add a radiotap header containing all the fields which the hardware provided.
108  */
109 static void
110 ieee80211_add_rx_radiotap_header(struct ieee80211_local *local,
111 				 struct sk_buff *skb,
112 				 struct ieee80211_rx_status *status,
113 				 struct ieee80211_rate *rate,
114 				 int rtap_len)
115 {
116 	struct ieee80211_radiotap_header *rthdr;
117 	unsigned char *pos;
118 
119 	rthdr = (struct ieee80211_radiotap_header *)skb_push(skb, rtap_len);
120 	memset(rthdr, 0, rtap_len);
121 
122 	/* radiotap header, set always present flags */
123 	rthdr->it_present =
124 		cpu_to_le32((1 << IEEE80211_RADIOTAP_FLAGS) |
125 			    (1 << IEEE80211_RADIOTAP_CHANNEL) |
126 			    (1 << IEEE80211_RADIOTAP_ANTENNA) |
127 			    (1 << IEEE80211_RADIOTAP_RX_FLAGS));
128 	rthdr->it_len = cpu_to_le16(rtap_len);
129 
130 	pos = (unsigned char *)(rthdr+1);
131 
132 	/* the order of the following fields is important */
133 
134 	/* IEEE80211_RADIOTAP_TSFT */
135 	if (status->flag & RX_FLAG_TSFT) {
136 		*(__le64 *)pos = cpu_to_le64(status->mactime);
137 		rthdr->it_present |=
138 			cpu_to_le32(1 << IEEE80211_RADIOTAP_TSFT);
139 		pos += 8;
140 	}
141 
142 	/* IEEE80211_RADIOTAP_FLAGS */
143 	if (local->hw.flags & IEEE80211_HW_RX_INCLUDES_FCS)
144 		*pos |= IEEE80211_RADIOTAP_F_FCS;
145 	if (status->flag & (RX_FLAG_FAILED_FCS_CRC | RX_FLAG_FAILED_PLCP_CRC))
146 		*pos |= IEEE80211_RADIOTAP_F_BADFCS;
147 	if (status->flag & RX_FLAG_SHORTPRE)
148 		*pos |= IEEE80211_RADIOTAP_F_SHORTPRE;
149 	pos++;
150 
151 	/* IEEE80211_RADIOTAP_RATE */
152 	if (status->flag & RX_FLAG_HT) {
153 		/*
154 		 * TODO: add following information into radiotap header once
155 		 * suitable fields are defined for it:
156 		 * - MCS index (status->rate_idx)
157 		 * - HT40 (status->flag & RX_FLAG_40MHZ)
158 		 * - short-GI (status->flag & RX_FLAG_SHORT_GI)
159 		 */
160 		*pos = 0;
161 	} else {
162 		rthdr->it_present |= cpu_to_le32(1 << IEEE80211_RADIOTAP_RATE);
163 		*pos = rate->bitrate / 5;
164 	}
165 	pos++;
166 
167 	/* IEEE80211_RADIOTAP_CHANNEL */
168 	*(__le16 *)pos = cpu_to_le16(status->freq);
169 	pos += 2;
170 	if (status->band == IEEE80211_BAND_5GHZ)
171 		*(__le16 *)pos = cpu_to_le16(IEEE80211_CHAN_OFDM |
172 					     IEEE80211_CHAN_5GHZ);
173 	else if (rate->flags & IEEE80211_RATE_ERP_G)
174 		*(__le16 *)pos = cpu_to_le16(IEEE80211_CHAN_OFDM |
175 					     IEEE80211_CHAN_2GHZ);
176 	else
177 		*(__le16 *)pos = cpu_to_le16(IEEE80211_CHAN_CCK |
178 					     IEEE80211_CHAN_2GHZ);
179 	pos += 2;
180 
181 	/* IEEE80211_RADIOTAP_DBM_ANTSIGNAL */
182 	if (local->hw.flags & IEEE80211_HW_SIGNAL_DBM) {
183 		*pos = status->signal;
184 		rthdr->it_present |=
185 			cpu_to_le32(1 << IEEE80211_RADIOTAP_DBM_ANTSIGNAL);
186 		pos++;
187 	}
188 
189 	/* IEEE80211_RADIOTAP_DBM_ANTNOISE */
190 	if (local->hw.flags & IEEE80211_HW_NOISE_DBM) {
191 		*pos = status->noise;
192 		rthdr->it_present |=
193 			cpu_to_le32(1 << IEEE80211_RADIOTAP_DBM_ANTNOISE);
194 		pos++;
195 	}
196 
197 	/* IEEE80211_RADIOTAP_LOCK_QUALITY is missing */
198 
199 	/* IEEE80211_RADIOTAP_ANTENNA */
200 	*pos = status->antenna;
201 	pos++;
202 
203 	/* IEEE80211_RADIOTAP_DB_ANTNOISE is not used */
204 
205 	/* IEEE80211_RADIOTAP_RX_FLAGS */
206 	/* ensure 2 byte alignment for the 2 byte field as required */
207 	if ((pos - (unsigned char *)rthdr) & 1)
208 		pos++;
209 	if (status->flag & RX_FLAG_FAILED_PLCP_CRC)
210 		*(__le16 *)pos |= cpu_to_le16(IEEE80211_RADIOTAP_F_RX_BADPLCP);
211 	pos += 2;
212 }
213 
214 /*
215  * This function copies a received frame to all monitor interfaces and
216  * returns a cleaned-up SKB that no longer includes the FCS nor the
217  * radiotap header the driver might have added.
218  */
219 static struct sk_buff *
220 ieee80211_rx_monitor(struct ieee80211_local *local, struct sk_buff *origskb,
221 		     struct ieee80211_rx_status *status,
222 		     struct ieee80211_rate *rate)
223 {
224 	struct ieee80211_sub_if_data *sdata;
225 	int needed_headroom = 0;
226 	struct sk_buff *skb, *skb2;
227 	struct net_device *prev_dev = NULL;
228 	int present_fcs_len = 0;
229 	int rtap_len = 0;
230 
231 	/*
232 	 * First, we may need to make a copy of the skb because
233 	 *  (1) we need to modify it for radiotap (if not present), and
234 	 *  (2) the other RX handlers will modify the skb we got.
235 	 *
236 	 * We don't need to, of course, if we aren't going to return
237 	 * the SKB because it has a bad FCS/PLCP checksum.
238 	 */
239 	if (status->flag & RX_FLAG_RADIOTAP)
240 		rtap_len = ieee80211_get_radiotap_len(origskb->data);
241 	else
242 		/* room for the radiotap header based on driver features */
243 		needed_headroom = ieee80211_rx_radiotap_len(local, status);
244 
245 	if (local->hw.flags & IEEE80211_HW_RX_INCLUDES_FCS)
246 		present_fcs_len = FCS_LEN;
247 
248 	if (!local->monitors) {
249 		if (should_drop_frame(status, origskb, present_fcs_len,
250 				      rtap_len)) {
251 			dev_kfree_skb(origskb);
252 			return NULL;
253 		}
254 
255 		return remove_monitor_info(local, origskb, rtap_len);
256 	}
257 
258 	if (should_drop_frame(status, origskb, present_fcs_len, rtap_len)) {
259 		/* only need to expand headroom if necessary */
260 		skb = origskb;
261 		origskb = NULL;
262 
263 		/*
264 		 * This shouldn't trigger often because most devices have an
265 		 * RX header they pull before we get here, and that should
266 		 * be big enough for our radiotap information. We should
267 		 * probably export the length to drivers so that we can have
268 		 * them allocate enough headroom to start with.
269 		 */
270 		if (skb_headroom(skb) < needed_headroom &&
271 		    pskb_expand_head(skb, needed_headroom, 0, GFP_ATOMIC)) {
272 			dev_kfree_skb(skb);
273 			return NULL;
274 		}
275 	} else {
276 		/*
277 		 * Need to make a copy and possibly remove radiotap header
278 		 * and FCS from the original.
279 		 */
280 		skb = skb_copy_expand(origskb, needed_headroom, 0, GFP_ATOMIC);
281 
282 		origskb = remove_monitor_info(local, origskb, rtap_len);
283 
284 		if (!skb)
285 			return origskb;
286 	}
287 
288 	/* if necessary, prepend radiotap information */
289 	if (!(status->flag & RX_FLAG_RADIOTAP))
290 		ieee80211_add_rx_radiotap_header(local, skb, status, rate,
291 						 needed_headroom);
292 
293 	skb_reset_mac_header(skb);
294 	skb->ip_summed = CHECKSUM_UNNECESSARY;
295 	skb->pkt_type = PACKET_OTHERHOST;
296 	skb->protocol = htons(ETH_P_802_2);
297 
298 	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
299 		if (!netif_running(sdata->dev))
300 			continue;
301 
302 		if (sdata->vif.type != NL80211_IFTYPE_MONITOR)
303 			continue;
304 
305 		if (sdata->u.mntr_flags & MONITOR_FLAG_COOK_FRAMES)
306 			continue;
307 
308 		if (prev_dev) {
309 			skb2 = skb_clone(skb, GFP_ATOMIC);
310 			if (skb2) {
311 				skb2->dev = prev_dev;
312 				netif_rx(skb2);
313 			}
314 		}
315 
316 		prev_dev = sdata->dev;
317 		sdata->dev->stats.rx_packets++;
318 		sdata->dev->stats.rx_bytes += skb->len;
319 	}
320 
321 	if (prev_dev) {
322 		skb->dev = prev_dev;
323 		netif_rx(skb);
324 	} else
325 		dev_kfree_skb(skb);
326 
327 	return origskb;
328 }
329 
330 
331 static void ieee80211_parse_qos(struct ieee80211_rx_data *rx)
332 {
333 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
334 	int tid;
335 
336 	/* does the frame have a qos control field? */
337 	if (ieee80211_is_data_qos(hdr->frame_control)) {
338 		u8 *qc = ieee80211_get_qos_ctl(hdr);
339 		/* frame has qos control */
340 		tid = *qc & IEEE80211_QOS_CTL_TID_MASK;
341 		if (*qc & IEEE80211_QOS_CONTROL_A_MSDU_PRESENT)
342 			rx->flags |= IEEE80211_RX_AMSDU;
343 		else
344 			rx->flags &= ~IEEE80211_RX_AMSDU;
345 	} else {
346 		/*
347 		 * IEEE 802.11-2007, 7.1.3.4.1 ("Sequence Number field"):
348 		 *
349 		 *	Sequence numbers for management frames, QoS data
350 		 *	frames with a broadcast/multicast address in the
351 		 *	Address 1 field, and all non-QoS data frames sent
352 		 *	by QoS STAs are assigned using an additional single
353 		 *	modulo-4096 counter, [...]
354 		 *
355 		 * We also use that counter for non-QoS STAs.
356 		 */
357 		tid = NUM_RX_DATA_QUEUES - 1;
358 	}
359 
360 	rx->queue = tid;
361 	/* Set skb->priority to 1d tag if highest order bit of TID is not set.
362 	 * For now, set skb->priority to 0 for other cases. */
363 	rx->skb->priority = (tid > 7) ? 0 : tid;
364 }
365 
366 /**
367  * DOC: Packet alignment
368  *
369  * Drivers always need to pass packets that are aligned to two-byte boundaries
370  * to the stack.
371  *
372  * Additionally, should, if possible, align the payload data in a way that
373  * guarantees that the contained IP header is aligned to a four-byte
374  * boundary. In the case of regular frames, this simply means aligning the
375  * payload to a four-byte boundary (because either the IP header is directly
376  * contained, or IV/RFC1042 headers that have a length divisible by four are
377  * in front of it).
378  *
379  * With A-MSDU frames, however, the payload data address must yield two modulo
380  * four because there are 14-byte 802.3 headers within the A-MSDU frames that
381  * push the IP header further back to a multiple of four again. Thankfully, the
382  * specs were sane enough this time around to require padding each A-MSDU
383  * subframe to a length that is a multiple of four.
384  *
385  * Padding like Atheros hardware adds which is inbetween the 802.11 header and
386  * the payload is not supported, the driver is required to move the 802.11
387  * header to be directly in front of the payload in that case.
388  */
389 static void ieee80211_verify_alignment(struct ieee80211_rx_data *rx)
390 {
391 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
392 	int hdrlen;
393 
394 #ifndef CONFIG_MAC80211_DEBUG_PACKET_ALIGNMENT
395 	return;
396 #endif
397 
398 	if (WARN_ONCE((unsigned long)rx->skb->data & 1,
399 		      "unaligned packet at 0x%p\n", rx->skb->data))
400 		return;
401 
402 	if (!ieee80211_is_data_present(hdr->frame_control))
403 		return;
404 
405 	hdrlen = ieee80211_hdrlen(hdr->frame_control);
406 	if (rx->flags & IEEE80211_RX_AMSDU)
407 		hdrlen += ETH_HLEN;
408 	WARN_ONCE(((unsigned long)(rx->skb->data + hdrlen)) & 3,
409 		  "unaligned IP payload at 0x%p\n", rx->skb->data + hdrlen);
410 }
411 
412 
413 /* rx handlers */
414 
415 static ieee80211_rx_result debug_noinline
416 ieee80211_rx_h_passive_scan(struct ieee80211_rx_data *rx)
417 {
418 	struct ieee80211_local *local = rx->local;
419 	struct sk_buff *skb = rx->skb;
420 
421 	if (unlikely(local->hw_scanning))
422 		return ieee80211_scan_rx(rx->sdata, skb, rx->status);
423 
424 	if (unlikely(local->sw_scanning)) {
425 		/* drop all the other packets during a software scan anyway */
426 		if (ieee80211_scan_rx(rx->sdata, skb, rx->status)
427 		    != RX_QUEUED)
428 			dev_kfree_skb(skb);
429 		return RX_QUEUED;
430 	}
431 
432 	if (unlikely(rx->flags & IEEE80211_RX_IN_SCAN)) {
433 		/* scanning finished during invoking of handlers */
434 		I802_DEBUG_INC(local->rx_handlers_drop_passive_scan);
435 		return RX_DROP_UNUSABLE;
436 	}
437 
438 	return RX_CONTINUE;
439 }
440 
441 
442 static int ieee80211_is_unicast_robust_mgmt_frame(struct sk_buff *skb)
443 {
444 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
445 
446 	if (skb->len < 24 || is_multicast_ether_addr(hdr->addr1))
447 		return 0;
448 
449 	return ieee80211_is_robust_mgmt_frame(hdr);
450 }
451 
452 
453 static int ieee80211_is_multicast_robust_mgmt_frame(struct sk_buff *skb)
454 {
455 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
456 
457 	if (skb->len < 24 || !is_multicast_ether_addr(hdr->addr1))
458 		return 0;
459 
460 	return ieee80211_is_robust_mgmt_frame(hdr);
461 }
462 
463 
464 /* Get the BIP key index from MMIE; return -1 if this is not a BIP frame */
465 static int ieee80211_get_mmie_keyidx(struct sk_buff *skb)
466 {
467 	struct ieee80211_mgmt *hdr = (struct ieee80211_mgmt *) skb->data;
468 	struct ieee80211_mmie *mmie;
469 
470 	if (skb->len < 24 + sizeof(*mmie) ||
471 	    !is_multicast_ether_addr(hdr->da))
472 		return -1;
473 
474 	if (!ieee80211_is_robust_mgmt_frame((struct ieee80211_hdr *) hdr))
475 		return -1; /* not a robust management frame */
476 
477 	mmie = (struct ieee80211_mmie *)
478 		(skb->data + skb->len - sizeof(*mmie));
479 	if (mmie->element_id != WLAN_EID_MMIE ||
480 	    mmie->length != sizeof(*mmie) - 2)
481 		return -1;
482 
483 	return le16_to_cpu(mmie->key_id);
484 }
485 
486 
487 static ieee80211_rx_result
488 ieee80211_rx_mesh_check(struct ieee80211_rx_data *rx)
489 {
490 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
491 	unsigned int hdrlen = ieee80211_hdrlen(hdr->frame_control);
492 
493 	if (ieee80211_is_data(hdr->frame_control)) {
494 		if (!ieee80211_has_a4(hdr->frame_control))
495 			return RX_DROP_MONITOR;
496 		if (memcmp(hdr->addr4, rx->dev->dev_addr, ETH_ALEN) == 0)
497 			return RX_DROP_MONITOR;
498 	}
499 
500 	/* If there is not an established peer link and this is not a peer link
501 	 * establisment frame, beacon or probe, drop the frame.
502 	 */
503 
504 	if (!rx->sta || sta_plink_state(rx->sta) != PLINK_ESTAB) {
505 		struct ieee80211_mgmt *mgmt;
506 
507 		if (!ieee80211_is_mgmt(hdr->frame_control))
508 			return RX_DROP_MONITOR;
509 
510 		if (ieee80211_is_action(hdr->frame_control)) {
511 			mgmt = (struct ieee80211_mgmt *)hdr;
512 			if (mgmt->u.action.category != PLINK_CATEGORY)
513 				return RX_DROP_MONITOR;
514 			return RX_CONTINUE;
515 		}
516 
517 		if (ieee80211_is_probe_req(hdr->frame_control) ||
518 		    ieee80211_is_probe_resp(hdr->frame_control) ||
519 		    ieee80211_is_beacon(hdr->frame_control))
520 			return RX_CONTINUE;
521 
522 		return RX_DROP_MONITOR;
523 
524 	}
525 
526 #define msh_h_get(h, l) ((struct ieee80211s_hdr *) ((u8 *)h + l))
527 
528 	if (ieee80211_is_data(hdr->frame_control) &&
529 	    is_multicast_ether_addr(hdr->addr1) &&
530 	    mesh_rmc_check(hdr->addr4, msh_h_get(hdr, hdrlen), rx->sdata))
531 		return RX_DROP_MONITOR;
532 #undef msh_h_get
533 
534 	return RX_CONTINUE;
535 }
536 
537 
538 static ieee80211_rx_result debug_noinline
539 ieee80211_rx_h_check(struct ieee80211_rx_data *rx)
540 {
541 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
542 
543 	/* Drop duplicate 802.11 retransmissions (IEEE 802.11 Chap. 9.2.9) */
544 	if (rx->sta && !is_multicast_ether_addr(hdr->addr1)) {
545 		if (unlikely(ieee80211_has_retry(hdr->frame_control) &&
546 			     rx->sta->last_seq_ctrl[rx->queue] ==
547 			     hdr->seq_ctrl)) {
548 			if (rx->flags & IEEE80211_RX_RA_MATCH) {
549 				rx->local->dot11FrameDuplicateCount++;
550 				rx->sta->num_duplicates++;
551 			}
552 			return RX_DROP_MONITOR;
553 		} else
554 			rx->sta->last_seq_ctrl[rx->queue] = hdr->seq_ctrl;
555 	}
556 
557 	if (unlikely(rx->skb->len < 16)) {
558 		I802_DEBUG_INC(rx->local->rx_handlers_drop_short);
559 		return RX_DROP_MONITOR;
560 	}
561 
562 	/* Drop disallowed frame classes based on STA auth/assoc state;
563 	 * IEEE 802.11, Chap 5.5.
564 	 *
565 	 * mac80211 filters only based on association state, i.e. it drops
566 	 * Class 3 frames from not associated stations. hostapd sends
567 	 * deauth/disassoc frames when needed. In addition, hostapd is
568 	 * responsible for filtering on both auth and assoc states.
569 	 */
570 
571 	if (ieee80211_vif_is_mesh(&rx->sdata->vif))
572 		return ieee80211_rx_mesh_check(rx);
573 
574 	if (unlikely((ieee80211_is_data(hdr->frame_control) ||
575 		      ieee80211_is_pspoll(hdr->frame_control)) &&
576 		     rx->sdata->vif.type != NL80211_IFTYPE_ADHOC &&
577 		     (!rx->sta || !test_sta_flags(rx->sta, WLAN_STA_ASSOC)))) {
578 		if ((!ieee80211_has_fromds(hdr->frame_control) &&
579 		     !ieee80211_has_tods(hdr->frame_control) &&
580 		     ieee80211_is_data(hdr->frame_control)) ||
581 		    !(rx->flags & IEEE80211_RX_RA_MATCH)) {
582 			/* Drop IBSS frames and frames for other hosts
583 			 * silently. */
584 			return RX_DROP_MONITOR;
585 		}
586 
587 		return RX_DROP_MONITOR;
588 	}
589 
590 	return RX_CONTINUE;
591 }
592 
593 
594 static ieee80211_rx_result debug_noinline
595 ieee80211_rx_h_decrypt(struct ieee80211_rx_data *rx)
596 {
597 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
598 	int keyidx;
599 	int hdrlen;
600 	ieee80211_rx_result result = RX_DROP_UNUSABLE;
601 	struct ieee80211_key *stakey = NULL;
602 	int mmie_keyidx = -1;
603 
604 	/*
605 	 * Key selection 101
606 	 *
607 	 * There are four types of keys:
608 	 *  - GTK (group keys)
609 	 *  - IGTK (group keys for management frames)
610 	 *  - PTK (pairwise keys)
611 	 *  - STK (station-to-station pairwise keys)
612 	 *
613 	 * When selecting a key, we have to distinguish between multicast
614 	 * (including broadcast) and unicast frames, the latter can only
615 	 * use PTKs and STKs while the former always use GTKs and IGTKs.
616 	 * Unless, of course, actual WEP keys ("pre-RSNA") are used, then
617 	 * unicast frames can also use key indices like GTKs. Hence, if we
618 	 * don't have a PTK/STK we check the key index for a WEP key.
619 	 *
620 	 * Note that in a regular BSS, multicast frames are sent by the
621 	 * AP only, associated stations unicast the frame to the AP first
622 	 * which then multicasts it on their behalf.
623 	 *
624 	 * There is also a slight problem in IBSS mode: GTKs are negotiated
625 	 * with each station, that is something we don't currently handle.
626 	 * The spec seems to expect that one negotiates the same key with
627 	 * every station but there's no such requirement; VLANs could be
628 	 * possible.
629 	 */
630 
631 	if (!ieee80211_has_protected(hdr->frame_control)) {
632 		if (!ieee80211_is_mgmt(hdr->frame_control) ||
633 		    rx->sta == NULL || !test_sta_flags(rx->sta, WLAN_STA_MFP))
634 			return RX_CONTINUE;
635 		mmie_keyidx = ieee80211_get_mmie_keyidx(rx->skb);
636 		if (mmie_keyidx < 0)
637 			return RX_CONTINUE;
638 	}
639 
640 	/*
641 	 * No point in finding a key and decrypting if the frame is neither
642 	 * addressed to us nor a multicast frame.
643 	 */
644 	if (!(rx->flags & IEEE80211_RX_RA_MATCH))
645 		return RX_CONTINUE;
646 
647 	if (rx->sta)
648 		stakey = rcu_dereference(rx->sta->key);
649 
650 	if (!is_multicast_ether_addr(hdr->addr1) && stakey) {
651 		rx->key = stakey;
652 	} else if (mmie_keyidx >= 0) {
653 		/* Broadcast/multicast robust management frame / BIP */
654 		if ((rx->status->flag & RX_FLAG_DECRYPTED) &&
655 		    (rx->status->flag & RX_FLAG_IV_STRIPPED))
656 			return RX_CONTINUE;
657 
658 		if (mmie_keyidx < NUM_DEFAULT_KEYS ||
659 		    mmie_keyidx >= NUM_DEFAULT_KEYS + NUM_DEFAULT_MGMT_KEYS)
660 			return RX_DROP_MONITOR; /* unexpected BIP keyidx */
661 		rx->key = rcu_dereference(rx->sdata->keys[mmie_keyidx]);
662 	} else {
663 		/*
664 		 * The device doesn't give us the IV so we won't be
665 		 * able to look up the key. That's ok though, we
666 		 * don't need to decrypt the frame, we just won't
667 		 * be able to keep statistics accurate.
668 		 * Except for key threshold notifications, should
669 		 * we somehow allow the driver to tell us which key
670 		 * the hardware used if this flag is set?
671 		 */
672 		if ((rx->status->flag & RX_FLAG_DECRYPTED) &&
673 		    (rx->status->flag & RX_FLAG_IV_STRIPPED))
674 			return RX_CONTINUE;
675 
676 		hdrlen = ieee80211_hdrlen(hdr->frame_control);
677 
678 		if (rx->skb->len < 8 + hdrlen)
679 			return RX_DROP_UNUSABLE; /* TODO: count this? */
680 
681 		/*
682 		 * no need to call ieee80211_wep_get_keyidx,
683 		 * it verifies a bunch of things we've done already
684 		 */
685 		keyidx = rx->skb->data[hdrlen + 3] >> 6;
686 
687 		rx->key = rcu_dereference(rx->sdata->keys[keyidx]);
688 
689 		/*
690 		 * RSNA-protected unicast frames should always be sent with
691 		 * pairwise or station-to-station keys, but for WEP we allow
692 		 * using a key index as well.
693 		 */
694 		if (rx->key && rx->key->conf.alg != ALG_WEP &&
695 		    !is_multicast_ether_addr(hdr->addr1))
696 			rx->key = NULL;
697 	}
698 
699 	if (rx->key) {
700 		rx->key->tx_rx_count++;
701 		/* TODO: add threshold stuff again */
702 	} else {
703 		return RX_DROP_MONITOR;
704 	}
705 
706 	/* Check for weak IVs if possible */
707 	if (rx->sta && rx->key->conf.alg == ALG_WEP &&
708 	    ieee80211_is_data(hdr->frame_control) &&
709 	    (!(rx->status->flag & RX_FLAG_IV_STRIPPED) ||
710 	     !(rx->status->flag & RX_FLAG_DECRYPTED)) &&
711 	    ieee80211_wep_is_weak_iv(rx->skb, rx->key))
712 		rx->sta->wep_weak_iv_count++;
713 
714 	switch (rx->key->conf.alg) {
715 	case ALG_WEP:
716 		result = ieee80211_crypto_wep_decrypt(rx);
717 		break;
718 	case ALG_TKIP:
719 		result = ieee80211_crypto_tkip_decrypt(rx);
720 		break;
721 	case ALG_CCMP:
722 		result = ieee80211_crypto_ccmp_decrypt(rx);
723 		break;
724 	case ALG_AES_CMAC:
725 		result = ieee80211_crypto_aes_cmac_decrypt(rx);
726 		break;
727 	}
728 
729 	/* either the frame has been decrypted or will be dropped */
730 	rx->status->flag |= RX_FLAG_DECRYPTED;
731 
732 	return result;
733 }
734 
735 static ieee80211_rx_result debug_noinline
736 ieee80211_rx_h_check_more_data(struct ieee80211_rx_data *rx)
737 {
738 	struct ieee80211_local *local;
739 	struct ieee80211_hdr *hdr;
740 	struct sk_buff *skb;
741 
742 	local = rx->local;
743 	skb = rx->skb;
744 	hdr = (struct ieee80211_hdr *) skb->data;
745 
746 	if (!local->pspolling)
747 		return RX_CONTINUE;
748 
749 	if (!ieee80211_has_fromds(hdr->frame_control))
750 		/* this is not from AP */
751 		return RX_CONTINUE;
752 
753 	if (!ieee80211_is_data(hdr->frame_control))
754 		return RX_CONTINUE;
755 
756 	if (!ieee80211_has_moredata(hdr->frame_control)) {
757 		/* AP has no more frames buffered for us */
758 		local->pspolling = false;
759 		return RX_CONTINUE;
760 	}
761 
762 	/* more data bit is set, let's request a new frame from the AP */
763 	ieee80211_send_pspoll(local, rx->sdata);
764 
765 	return RX_CONTINUE;
766 }
767 
768 static void ap_sta_ps_start(struct sta_info *sta)
769 {
770 	struct ieee80211_sub_if_data *sdata = sta->sdata;
771 	struct ieee80211_local *local = sdata->local;
772 
773 	atomic_inc(&sdata->bss->num_sta_ps);
774 	set_and_clear_sta_flags(sta, WLAN_STA_PS, WLAN_STA_PSPOLL);
775 	if (local->ops->sta_notify)
776 		local->ops->sta_notify(local_to_hw(local), &sdata->vif,
777 					STA_NOTIFY_SLEEP, &sta->sta);
778 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
779 	printk(KERN_DEBUG "%s: STA %pM aid %d enters power save mode\n",
780 	       sdata->dev->name, sta->sta.addr, sta->sta.aid);
781 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
782 }
783 
784 static int ap_sta_ps_end(struct sta_info *sta)
785 {
786 	struct ieee80211_sub_if_data *sdata = sta->sdata;
787 	struct ieee80211_local *local = sdata->local;
788 	struct sk_buff *skb;
789 	int sent = 0;
790 
791 	atomic_dec(&sdata->bss->num_sta_ps);
792 
793 	clear_sta_flags(sta, WLAN_STA_PS | WLAN_STA_PSPOLL);
794 	if (local->ops->sta_notify)
795 		local->ops->sta_notify(local_to_hw(local), &sdata->vif,
796 					STA_NOTIFY_AWAKE, &sta->sta);
797 
798 	if (!skb_queue_empty(&sta->ps_tx_buf))
799 		sta_info_clear_tim_bit(sta);
800 
801 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
802 	printk(KERN_DEBUG "%s: STA %pM aid %d exits power save mode\n",
803 	       sdata->dev->name, sta->sta.addr, sta->sta.aid);
804 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
805 
806 	/* Send all buffered frames to the station */
807 	while ((skb = skb_dequeue(&sta->tx_filtered)) != NULL) {
808 		sent++;
809 		skb->requeue = 1;
810 		dev_queue_xmit(skb);
811 	}
812 	while ((skb = skb_dequeue(&sta->ps_tx_buf)) != NULL) {
813 		local->total_ps_buffered--;
814 		sent++;
815 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
816 		printk(KERN_DEBUG "%s: STA %pM aid %d send PS frame "
817 		       "since STA not sleeping anymore\n", sdata->dev->name,
818 		       sta->sta.addr, sta->sta.aid);
819 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
820 		skb->requeue = 1;
821 		dev_queue_xmit(skb);
822 	}
823 
824 	return sent;
825 }
826 
827 static ieee80211_rx_result debug_noinline
828 ieee80211_rx_h_sta_process(struct ieee80211_rx_data *rx)
829 {
830 	struct sta_info *sta = rx->sta;
831 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
832 
833 	if (!sta)
834 		return RX_CONTINUE;
835 
836 	/* Update last_rx only for IBSS packets which are for the current
837 	 * BSSID to avoid keeping the current IBSS network alive in cases where
838 	 * other STAs are using different BSSID. */
839 	if (rx->sdata->vif.type == NL80211_IFTYPE_ADHOC) {
840 		u8 *bssid = ieee80211_get_bssid(hdr, rx->skb->len,
841 						NL80211_IFTYPE_ADHOC);
842 		if (compare_ether_addr(bssid, rx->sdata->u.ibss.bssid) == 0)
843 			sta->last_rx = jiffies;
844 	} else
845 	if (!is_multicast_ether_addr(hdr->addr1) ||
846 	    rx->sdata->vif.type == NL80211_IFTYPE_STATION) {
847 		/* Update last_rx only for unicast frames in order to prevent
848 		 * the Probe Request frames (the only broadcast frames from a
849 		 * STA in infrastructure mode) from keeping a connection alive.
850 		 * Mesh beacons will update last_rx when if they are found to
851 		 * match the current local configuration when processed.
852 		 */
853 		if (rx->sdata->vif.type == NL80211_IFTYPE_STATION &&
854 		    ieee80211_is_beacon(hdr->frame_control)) {
855 			rx->sdata->u.mgd.last_beacon = jiffies;
856 		} else
857 			sta->last_rx = jiffies;
858 	}
859 
860 	if (!(rx->flags & IEEE80211_RX_RA_MATCH))
861 		return RX_CONTINUE;
862 
863 	if (rx->sdata->vif.type == NL80211_IFTYPE_STATION)
864 		ieee80211_sta_rx_notify(rx->sdata, hdr);
865 
866 	sta->rx_fragments++;
867 	sta->rx_bytes += rx->skb->len;
868 	sta->last_signal = rx->status->signal;
869 	sta->last_qual = rx->status->qual;
870 	sta->last_noise = rx->status->noise;
871 
872 	/*
873 	 * Change STA power saving mode only at the end of a frame
874 	 * exchange sequence.
875 	 */
876 	if (!ieee80211_has_morefrags(hdr->frame_control) &&
877 	    (rx->sdata->vif.type == NL80211_IFTYPE_AP ||
878 	     rx->sdata->vif.type == NL80211_IFTYPE_AP_VLAN)) {
879 		if (test_sta_flags(sta, WLAN_STA_PS)) {
880 			/*
881 			 * Ignore doze->wake transitions that are
882 			 * indicated by non-data frames, the standard
883 			 * is unclear here, but for example going to
884 			 * PS mode and then scanning would cause a
885 			 * doze->wake transition for the probe request,
886 			 * and that is clearly undesirable.
887 			 */
888 			if (ieee80211_is_data(hdr->frame_control) &&
889 			    !ieee80211_has_pm(hdr->frame_control))
890 				rx->sent_ps_buffered += ap_sta_ps_end(sta);
891 		} else {
892 			if (ieee80211_has_pm(hdr->frame_control))
893 				ap_sta_ps_start(sta);
894 		}
895 	}
896 
897 	/* Drop data::nullfunc frames silently, since they are used only to
898 	 * control station power saving mode. */
899 	if (ieee80211_is_nullfunc(hdr->frame_control)) {
900 		I802_DEBUG_INC(rx->local->rx_handlers_drop_nullfunc);
901 		/* Update counter and free packet here to avoid counting this
902 		 * as a dropped packed. */
903 		sta->rx_packets++;
904 		dev_kfree_skb(rx->skb);
905 		return RX_QUEUED;
906 	}
907 
908 	return RX_CONTINUE;
909 } /* ieee80211_rx_h_sta_process */
910 
911 static inline struct ieee80211_fragment_entry *
912 ieee80211_reassemble_add(struct ieee80211_sub_if_data *sdata,
913 			 unsigned int frag, unsigned int seq, int rx_queue,
914 			 struct sk_buff **skb)
915 {
916 	struct ieee80211_fragment_entry *entry;
917 	int idx;
918 
919 	idx = sdata->fragment_next;
920 	entry = &sdata->fragments[sdata->fragment_next++];
921 	if (sdata->fragment_next >= IEEE80211_FRAGMENT_MAX)
922 		sdata->fragment_next = 0;
923 
924 	if (!skb_queue_empty(&entry->skb_list)) {
925 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG
926 		struct ieee80211_hdr *hdr =
927 			(struct ieee80211_hdr *) entry->skb_list.next->data;
928 		printk(KERN_DEBUG "%s: RX reassembly removed oldest "
929 		       "fragment entry (idx=%d age=%lu seq=%d last_frag=%d "
930 		       "addr1=%pM addr2=%pM\n",
931 		       sdata->dev->name, idx,
932 		       jiffies - entry->first_frag_time, entry->seq,
933 		       entry->last_frag, hdr->addr1, hdr->addr2);
934 #endif
935 		__skb_queue_purge(&entry->skb_list);
936 	}
937 
938 	__skb_queue_tail(&entry->skb_list, *skb); /* no need for locking */
939 	*skb = NULL;
940 	entry->first_frag_time = jiffies;
941 	entry->seq = seq;
942 	entry->rx_queue = rx_queue;
943 	entry->last_frag = frag;
944 	entry->ccmp = 0;
945 	entry->extra_len = 0;
946 
947 	return entry;
948 }
949 
950 static inline struct ieee80211_fragment_entry *
951 ieee80211_reassemble_find(struct ieee80211_sub_if_data *sdata,
952 			  unsigned int frag, unsigned int seq,
953 			  int rx_queue, struct ieee80211_hdr *hdr)
954 {
955 	struct ieee80211_fragment_entry *entry;
956 	int i, idx;
957 
958 	idx = sdata->fragment_next;
959 	for (i = 0; i < IEEE80211_FRAGMENT_MAX; i++) {
960 		struct ieee80211_hdr *f_hdr;
961 
962 		idx--;
963 		if (idx < 0)
964 			idx = IEEE80211_FRAGMENT_MAX - 1;
965 
966 		entry = &sdata->fragments[idx];
967 		if (skb_queue_empty(&entry->skb_list) || entry->seq != seq ||
968 		    entry->rx_queue != rx_queue ||
969 		    entry->last_frag + 1 != frag)
970 			continue;
971 
972 		f_hdr = (struct ieee80211_hdr *)entry->skb_list.next->data;
973 
974 		/*
975 		 * Check ftype and addresses are equal, else check next fragment
976 		 */
977 		if (((hdr->frame_control ^ f_hdr->frame_control) &
978 		     cpu_to_le16(IEEE80211_FCTL_FTYPE)) ||
979 		    compare_ether_addr(hdr->addr1, f_hdr->addr1) != 0 ||
980 		    compare_ether_addr(hdr->addr2, f_hdr->addr2) != 0)
981 			continue;
982 
983 		if (time_after(jiffies, entry->first_frag_time + 2 * HZ)) {
984 			__skb_queue_purge(&entry->skb_list);
985 			continue;
986 		}
987 		return entry;
988 	}
989 
990 	return NULL;
991 }
992 
993 static ieee80211_rx_result debug_noinline
994 ieee80211_rx_h_defragment(struct ieee80211_rx_data *rx)
995 {
996 	struct ieee80211_hdr *hdr;
997 	u16 sc;
998 	__le16 fc;
999 	unsigned int frag, seq;
1000 	struct ieee80211_fragment_entry *entry;
1001 	struct sk_buff *skb;
1002 
1003 	hdr = (struct ieee80211_hdr *)rx->skb->data;
1004 	fc = hdr->frame_control;
1005 	sc = le16_to_cpu(hdr->seq_ctrl);
1006 	frag = sc & IEEE80211_SCTL_FRAG;
1007 
1008 	if (likely((!ieee80211_has_morefrags(fc) && frag == 0) ||
1009 		   (rx->skb)->len < 24 ||
1010 		   is_multicast_ether_addr(hdr->addr1))) {
1011 		/* not fragmented */
1012 		goto out;
1013 	}
1014 	I802_DEBUG_INC(rx->local->rx_handlers_fragments);
1015 
1016 	seq = (sc & IEEE80211_SCTL_SEQ) >> 4;
1017 
1018 	if (frag == 0) {
1019 		/* This is the first fragment of a new frame. */
1020 		entry = ieee80211_reassemble_add(rx->sdata, frag, seq,
1021 						 rx->queue, &(rx->skb));
1022 		if (rx->key && rx->key->conf.alg == ALG_CCMP &&
1023 		    ieee80211_has_protected(fc)) {
1024 			/* Store CCMP PN so that we can verify that the next
1025 			 * fragment has a sequential PN value. */
1026 			entry->ccmp = 1;
1027 			memcpy(entry->last_pn,
1028 			       rx->key->u.ccmp.rx_pn[rx->queue],
1029 			       CCMP_PN_LEN);
1030 		}
1031 		return RX_QUEUED;
1032 	}
1033 
1034 	/* This is a fragment for a frame that should already be pending in
1035 	 * fragment cache. Add this fragment to the end of the pending entry.
1036 	 */
1037 	entry = ieee80211_reassemble_find(rx->sdata, frag, seq, rx->queue, hdr);
1038 	if (!entry) {
1039 		I802_DEBUG_INC(rx->local->rx_handlers_drop_defrag);
1040 		return RX_DROP_MONITOR;
1041 	}
1042 
1043 	/* Verify that MPDUs within one MSDU have sequential PN values.
1044 	 * (IEEE 802.11i, 8.3.3.4.5) */
1045 	if (entry->ccmp) {
1046 		int i;
1047 		u8 pn[CCMP_PN_LEN], *rpn;
1048 		if (!rx->key || rx->key->conf.alg != ALG_CCMP)
1049 			return RX_DROP_UNUSABLE;
1050 		memcpy(pn, entry->last_pn, CCMP_PN_LEN);
1051 		for (i = CCMP_PN_LEN - 1; i >= 0; i--) {
1052 			pn[i]++;
1053 			if (pn[i])
1054 				break;
1055 		}
1056 		rpn = rx->key->u.ccmp.rx_pn[rx->queue];
1057 		if (memcmp(pn, rpn, CCMP_PN_LEN))
1058 			return RX_DROP_UNUSABLE;
1059 		memcpy(entry->last_pn, pn, CCMP_PN_LEN);
1060 	}
1061 
1062 	skb_pull(rx->skb, ieee80211_hdrlen(fc));
1063 	__skb_queue_tail(&entry->skb_list, rx->skb);
1064 	entry->last_frag = frag;
1065 	entry->extra_len += rx->skb->len;
1066 	if (ieee80211_has_morefrags(fc)) {
1067 		rx->skb = NULL;
1068 		return RX_QUEUED;
1069 	}
1070 
1071 	rx->skb = __skb_dequeue(&entry->skb_list);
1072 	if (skb_tailroom(rx->skb) < entry->extra_len) {
1073 		I802_DEBUG_INC(rx->local->rx_expand_skb_head2);
1074 		if (unlikely(pskb_expand_head(rx->skb, 0, entry->extra_len,
1075 					      GFP_ATOMIC))) {
1076 			I802_DEBUG_INC(rx->local->rx_handlers_drop_defrag);
1077 			__skb_queue_purge(&entry->skb_list);
1078 			return RX_DROP_UNUSABLE;
1079 		}
1080 	}
1081 	while ((skb = __skb_dequeue(&entry->skb_list))) {
1082 		memcpy(skb_put(rx->skb, skb->len), skb->data, skb->len);
1083 		dev_kfree_skb(skb);
1084 	}
1085 
1086 	/* Complete frame has been reassembled - process it now */
1087 	rx->flags |= IEEE80211_RX_FRAGMENTED;
1088 
1089  out:
1090 	if (rx->sta)
1091 		rx->sta->rx_packets++;
1092 	if (is_multicast_ether_addr(hdr->addr1))
1093 		rx->local->dot11MulticastReceivedFrameCount++;
1094 	else
1095 		ieee80211_led_rx(rx->local);
1096 	return RX_CONTINUE;
1097 }
1098 
1099 static ieee80211_rx_result debug_noinline
1100 ieee80211_rx_h_ps_poll(struct ieee80211_rx_data *rx)
1101 {
1102 	struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(rx->dev);
1103 	struct sk_buff *skb;
1104 	int no_pending_pkts;
1105 	__le16 fc = ((struct ieee80211_hdr *)rx->skb->data)->frame_control;
1106 
1107 	if (likely(!rx->sta || !ieee80211_is_pspoll(fc) ||
1108 		   !(rx->flags & IEEE80211_RX_RA_MATCH)))
1109 		return RX_CONTINUE;
1110 
1111 	if ((sdata->vif.type != NL80211_IFTYPE_AP) &&
1112 	    (sdata->vif.type != NL80211_IFTYPE_AP_VLAN))
1113 		return RX_DROP_UNUSABLE;
1114 
1115 	skb = skb_dequeue(&rx->sta->tx_filtered);
1116 	if (!skb) {
1117 		skb = skb_dequeue(&rx->sta->ps_tx_buf);
1118 		if (skb)
1119 			rx->local->total_ps_buffered--;
1120 	}
1121 	no_pending_pkts = skb_queue_empty(&rx->sta->tx_filtered) &&
1122 		skb_queue_empty(&rx->sta->ps_tx_buf);
1123 
1124 	if (skb) {
1125 		struct ieee80211_hdr *hdr =
1126 			(struct ieee80211_hdr *) skb->data;
1127 
1128 		/*
1129 		 * Tell TX path to send one frame even though the STA may
1130 		 * still remain is PS mode after this frame exchange.
1131 		 */
1132 		set_sta_flags(rx->sta, WLAN_STA_PSPOLL);
1133 
1134 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
1135 		printk(KERN_DEBUG "STA %pM aid %d: PS Poll (entries after %d)\n",
1136 		       rx->sta->sta.addr, rx->sta->sta.aid,
1137 		       skb_queue_len(&rx->sta->ps_tx_buf));
1138 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
1139 
1140 		/* Use MoreData flag to indicate whether there are more
1141 		 * buffered frames for this STA */
1142 		if (no_pending_pkts)
1143 			hdr->frame_control &= cpu_to_le16(~IEEE80211_FCTL_MOREDATA);
1144 		else
1145 			hdr->frame_control |= cpu_to_le16(IEEE80211_FCTL_MOREDATA);
1146 
1147 		dev_queue_xmit(skb);
1148 
1149 		if (no_pending_pkts)
1150 			sta_info_clear_tim_bit(rx->sta);
1151 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
1152 	} else if (!rx->sent_ps_buffered) {
1153 		/*
1154 		 * FIXME: This can be the result of a race condition between
1155 		 *	  us expiring a frame and the station polling for it.
1156 		 *	  Should we send it a null-func frame indicating we
1157 		 *	  have nothing buffered for it?
1158 		 */
1159 		printk(KERN_DEBUG "%s: STA %pM sent PS Poll even "
1160 		       "though there are no buffered frames for it\n",
1161 		       rx->dev->name, rx->sta->sta.addr);
1162 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
1163 	}
1164 
1165 	/* Free PS Poll skb here instead of returning RX_DROP that would
1166 	 * count as an dropped frame. */
1167 	dev_kfree_skb(rx->skb);
1168 
1169 	return RX_QUEUED;
1170 }
1171 
1172 static ieee80211_rx_result debug_noinline
1173 ieee80211_rx_h_remove_qos_control(struct ieee80211_rx_data *rx)
1174 {
1175 	u8 *data = rx->skb->data;
1176 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)data;
1177 
1178 	if (!ieee80211_is_data_qos(hdr->frame_control))
1179 		return RX_CONTINUE;
1180 
1181 	/* remove the qos control field, update frame type and meta-data */
1182 	memmove(data + IEEE80211_QOS_CTL_LEN, data,
1183 		ieee80211_hdrlen(hdr->frame_control) - IEEE80211_QOS_CTL_LEN);
1184 	hdr = (struct ieee80211_hdr *)skb_pull(rx->skb, IEEE80211_QOS_CTL_LEN);
1185 	/* change frame type to non QOS */
1186 	hdr->frame_control &= ~cpu_to_le16(IEEE80211_STYPE_QOS_DATA);
1187 
1188 	return RX_CONTINUE;
1189 }
1190 
1191 static int
1192 ieee80211_802_1x_port_control(struct ieee80211_rx_data *rx)
1193 {
1194 	if (unlikely(!rx->sta ||
1195 	    !test_sta_flags(rx->sta, WLAN_STA_AUTHORIZED)))
1196 		return -EACCES;
1197 
1198 	return 0;
1199 }
1200 
1201 static int
1202 ieee80211_drop_unencrypted(struct ieee80211_rx_data *rx, __le16 fc)
1203 {
1204 	/*
1205 	 * Pass through unencrypted frames if the hardware has
1206 	 * decrypted them already.
1207 	 */
1208 	if (rx->status->flag & RX_FLAG_DECRYPTED)
1209 		return 0;
1210 
1211 	/* Drop unencrypted frames if key is set. */
1212 	if (unlikely(!ieee80211_has_protected(fc) &&
1213 		     !ieee80211_is_nullfunc(fc) &&
1214 		     (!ieee80211_is_mgmt(fc) ||
1215 		      (ieee80211_is_unicast_robust_mgmt_frame(rx->skb) &&
1216 		       rx->sta && test_sta_flags(rx->sta, WLAN_STA_MFP))) &&
1217 		     (rx->key || rx->sdata->drop_unencrypted)))
1218 		return -EACCES;
1219 	/* BIP does not use Protected field, so need to check MMIE */
1220 	if (unlikely(rx->sta && test_sta_flags(rx->sta, WLAN_STA_MFP) &&
1221 		     ieee80211_is_multicast_robust_mgmt_frame(rx->skb) &&
1222 		     ieee80211_get_mmie_keyidx(rx->skb) < 0 &&
1223 		     (rx->key || rx->sdata->drop_unencrypted)))
1224 		return -EACCES;
1225 
1226 	return 0;
1227 }
1228 
1229 static int
1230 ieee80211_data_to_8023(struct ieee80211_rx_data *rx)
1231 {
1232 	struct net_device *dev = rx->dev;
1233 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) rx->skb->data;
1234 	u16 hdrlen, ethertype;
1235 	u8 *payload;
1236 	u8 dst[ETH_ALEN];
1237 	u8 src[ETH_ALEN] __aligned(2);
1238 	struct sk_buff *skb = rx->skb;
1239 	struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
1240 
1241 	if (unlikely(!ieee80211_is_data_present(hdr->frame_control)))
1242 		return -1;
1243 
1244 	hdrlen = ieee80211_hdrlen(hdr->frame_control);
1245 
1246 	/* convert IEEE 802.11 header + possible LLC headers into Ethernet
1247 	 * header
1248 	 * IEEE 802.11 address fields:
1249 	 * ToDS FromDS Addr1 Addr2 Addr3 Addr4
1250 	 *   0     0   DA    SA    BSSID n/a
1251 	 *   0     1   DA    BSSID SA    n/a
1252 	 *   1     0   BSSID SA    DA    n/a
1253 	 *   1     1   RA    TA    DA    SA
1254 	 */
1255 	memcpy(dst, ieee80211_get_DA(hdr), ETH_ALEN);
1256 	memcpy(src, ieee80211_get_SA(hdr), ETH_ALEN);
1257 
1258 	switch (hdr->frame_control &
1259 		cpu_to_le16(IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS)) {
1260 	case cpu_to_le16(IEEE80211_FCTL_TODS):
1261 		if (unlikely(sdata->vif.type != NL80211_IFTYPE_AP &&
1262 			     sdata->vif.type != NL80211_IFTYPE_AP_VLAN))
1263 			return -1;
1264 		break;
1265 	case cpu_to_le16(IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS):
1266 		if (unlikely(sdata->vif.type != NL80211_IFTYPE_WDS &&
1267 			     sdata->vif.type != NL80211_IFTYPE_MESH_POINT))
1268 			return -1;
1269 		if (ieee80211_vif_is_mesh(&sdata->vif)) {
1270 			struct ieee80211s_hdr *meshdr = (struct ieee80211s_hdr *)
1271 				(skb->data + hdrlen);
1272 			hdrlen += ieee80211_get_mesh_hdrlen(meshdr);
1273 			if (meshdr->flags & MESH_FLAGS_AE_A5_A6) {
1274 				memcpy(dst, meshdr->eaddr1, ETH_ALEN);
1275 				memcpy(src, meshdr->eaddr2, ETH_ALEN);
1276 			}
1277 		}
1278 		break;
1279 	case cpu_to_le16(IEEE80211_FCTL_FROMDS):
1280 		if (sdata->vif.type != NL80211_IFTYPE_STATION ||
1281 		    (is_multicast_ether_addr(dst) &&
1282 		     !compare_ether_addr(src, dev->dev_addr)))
1283 			return -1;
1284 		break;
1285 	case cpu_to_le16(0):
1286 		if (sdata->vif.type != NL80211_IFTYPE_ADHOC)
1287 			return -1;
1288 		break;
1289 	}
1290 
1291 	if (unlikely(skb->len - hdrlen < 8))
1292 		return -1;
1293 
1294 	payload = skb->data + hdrlen;
1295 	ethertype = (payload[6] << 8) | payload[7];
1296 
1297 	if (likely((compare_ether_addr(payload, rfc1042_header) == 0 &&
1298 		    ethertype != ETH_P_AARP && ethertype != ETH_P_IPX) ||
1299 		   compare_ether_addr(payload, bridge_tunnel_header) == 0)) {
1300 		/* remove RFC1042 or Bridge-Tunnel encapsulation and
1301 		 * replace EtherType */
1302 		skb_pull(skb, hdrlen + 6);
1303 		memcpy(skb_push(skb, ETH_ALEN), src, ETH_ALEN);
1304 		memcpy(skb_push(skb, ETH_ALEN), dst, ETH_ALEN);
1305 	} else {
1306 		struct ethhdr *ehdr;
1307 		__be16 len;
1308 
1309 		skb_pull(skb, hdrlen);
1310 		len = htons(skb->len);
1311 		ehdr = (struct ethhdr *) skb_push(skb, sizeof(struct ethhdr));
1312 		memcpy(ehdr->h_dest, dst, ETH_ALEN);
1313 		memcpy(ehdr->h_source, src, ETH_ALEN);
1314 		ehdr->h_proto = len;
1315 	}
1316 	return 0;
1317 }
1318 
1319 /*
1320  * requires that rx->skb is a frame with ethernet header
1321  */
1322 static bool ieee80211_frame_allowed(struct ieee80211_rx_data *rx, __le16 fc)
1323 {
1324 	static const u8 pae_group_addr[ETH_ALEN] __aligned(2)
1325 		= { 0x01, 0x80, 0xC2, 0x00, 0x00, 0x03 };
1326 	struct ethhdr *ehdr = (struct ethhdr *) rx->skb->data;
1327 
1328 	/*
1329 	 * Allow EAPOL frames to us/the PAE group address regardless
1330 	 * of whether the frame was encrypted or not.
1331 	 */
1332 	if (ehdr->h_proto == htons(ETH_P_PAE) &&
1333 	    (compare_ether_addr(ehdr->h_dest, rx->dev->dev_addr) == 0 ||
1334 	     compare_ether_addr(ehdr->h_dest, pae_group_addr) == 0))
1335 		return true;
1336 
1337 	if (ieee80211_802_1x_port_control(rx) ||
1338 	    ieee80211_drop_unencrypted(rx, fc))
1339 		return false;
1340 
1341 	return true;
1342 }
1343 
1344 /*
1345  * requires that rx->skb is a frame with ethernet header
1346  */
1347 static void
1348 ieee80211_deliver_skb(struct ieee80211_rx_data *rx)
1349 {
1350 	struct net_device *dev = rx->dev;
1351 	struct ieee80211_local *local = rx->local;
1352 	struct sk_buff *skb, *xmit_skb;
1353 	struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
1354 	struct ethhdr *ehdr = (struct ethhdr *) rx->skb->data;
1355 	struct sta_info *dsta;
1356 
1357 	skb = rx->skb;
1358 	xmit_skb = NULL;
1359 
1360 	if ((sdata->vif.type == NL80211_IFTYPE_AP ||
1361 	     sdata->vif.type == NL80211_IFTYPE_AP_VLAN) &&
1362 	    !(sdata->flags & IEEE80211_SDATA_DONT_BRIDGE_PACKETS) &&
1363 	    (rx->flags & IEEE80211_RX_RA_MATCH)) {
1364 		if (is_multicast_ether_addr(ehdr->h_dest)) {
1365 			/*
1366 			 * send multicast frames both to higher layers in
1367 			 * local net stack and back to the wireless medium
1368 			 */
1369 			xmit_skb = skb_copy(skb, GFP_ATOMIC);
1370 			if (!xmit_skb && net_ratelimit())
1371 				printk(KERN_DEBUG "%s: failed to clone "
1372 				       "multicast frame\n", dev->name);
1373 		} else {
1374 			dsta = sta_info_get(local, skb->data);
1375 			if (dsta && dsta->sdata->dev == dev) {
1376 				/*
1377 				 * The destination station is associated to
1378 				 * this AP (in this VLAN), so send the frame
1379 				 * directly to it and do not pass it to local
1380 				 * net stack.
1381 				 */
1382 				xmit_skb = skb;
1383 				skb = NULL;
1384 			}
1385 		}
1386 	}
1387 
1388 	if (skb) {
1389 		int align __maybe_unused;
1390 
1391 #if defined(CONFIG_MAC80211_DEBUG_PACKET_ALIGNMENT) || !defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS)
1392 		/*
1393 		 * 'align' will only take the values 0 or 2 here
1394 		 * since all frames are required to be aligned
1395 		 * to 2-byte boundaries when being passed to
1396 		 * mac80211. That also explains the __skb_push()
1397 		 * below.
1398 		 */
1399 		align = (unsigned long)skb->data & 4;
1400 		if (align) {
1401 			if (WARN_ON(skb_headroom(skb) < 3)) {
1402 				dev_kfree_skb(skb);
1403 				skb = NULL;
1404 			} else {
1405 				u8 *data = skb->data;
1406 				size_t len = skb->len;
1407 				u8 *new = __skb_push(skb, align);
1408 				memmove(new, data, len);
1409 				__skb_trim(skb, len);
1410 			}
1411 		}
1412 #endif
1413 
1414 		if (skb) {
1415 			/* deliver to local stack */
1416 			skb->protocol = eth_type_trans(skb, dev);
1417 			memset(skb->cb, 0, sizeof(skb->cb));
1418 			netif_rx(skb);
1419 		}
1420 	}
1421 
1422 	if (xmit_skb) {
1423 		/* send to wireless media */
1424 		xmit_skb->protocol = htons(ETH_P_802_3);
1425 		skb_reset_network_header(xmit_skb);
1426 		skb_reset_mac_header(xmit_skb);
1427 		dev_queue_xmit(xmit_skb);
1428 	}
1429 }
1430 
1431 static ieee80211_rx_result debug_noinline
1432 ieee80211_rx_h_amsdu(struct ieee80211_rx_data *rx)
1433 {
1434 	struct net_device *dev = rx->dev;
1435 	struct ieee80211_local *local = rx->local;
1436 	u16 ethertype;
1437 	u8 *payload;
1438 	struct sk_buff *skb = rx->skb, *frame = NULL;
1439 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
1440 	__le16 fc = hdr->frame_control;
1441 	const struct ethhdr *eth;
1442 	int remaining, err;
1443 	u8 dst[ETH_ALEN];
1444 	u8 src[ETH_ALEN];
1445 
1446 	if (unlikely(!ieee80211_is_data(fc)))
1447 		return RX_CONTINUE;
1448 
1449 	if (unlikely(!ieee80211_is_data_present(fc)))
1450 		return RX_DROP_MONITOR;
1451 
1452 	if (!(rx->flags & IEEE80211_RX_AMSDU))
1453 		return RX_CONTINUE;
1454 
1455 	err = ieee80211_data_to_8023(rx);
1456 	if (unlikely(err))
1457 		return RX_DROP_UNUSABLE;
1458 
1459 	skb->dev = dev;
1460 
1461 	dev->stats.rx_packets++;
1462 	dev->stats.rx_bytes += skb->len;
1463 
1464 	/* skip the wrapping header */
1465 	eth = (struct ethhdr *) skb_pull(skb, sizeof(struct ethhdr));
1466 	if (!eth)
1467 		return RX_DROP_UNUSABLE;
1468 
1469 	while (skb != frame) {
1470 		u8 padding;
1471 		__be16 len = eth->h_proto;
1472 		unsigned int subframe_len = sizeof(struct ethhdr) + ntohs(len);
1473 
1474 		remaining = skb->len;
1475 		memcpy(dst, eth->h_dest, ETH_ALEN);
1476 		memcpy(src, eth->h_source, ETH_ALEN);
1477 
1478 		padding = ((4 - subframe_len) & 0x3);
1479 		/* the last MSDU has no padding */
1480 		if (subframe_len > remaining)
1481 			return RX_DROP_UNUSABLE;
1482 
1483 		skb_pull(skb, sizeof(struct ethhdr));
1484 		/* if last subframe reuse skb */
1485 		if (remaining <= subframe_len + padding)
1486 			frame = skb;
1487 		else {
1488 			/*
1489 			 * Allocate and reserve two bytes more for payload
1490 			 * alignment since sizeof(struct ethhdr) is 14.
1491 			 */
1492 			frame = dev_alloc_skb(
1493 				ALIGN(local->hw.extra_tx_headroom, 4) +
1494 				subframe_len + 2);
1495 
1496 			if (frame == NULL)
1497 				return RX_DROP_UNUSABLE;
1498 
1499 			skb_reserve(frame,
1500 				    ALIGN(local->hw.extra_tx_headroom, 4) +
1501 				    sizeof(struct ethhdr) + 2);
1502 			memcpy(skb_put(frame, ntohs(len)), skb->data,
1503 				ntohs(len));
1504 
1505 			eth = (struct ethhdr *) skb_pull(skb, ntohs(len) +
1506 							padding);
1507 			if (!eth) {
1508 				dev_kfree_skb(frame);
1509 				return RX_DROP_UNUSABLE;
1510 			}
1511 		}
1512 
1513 		skb_reset_network_header(frame);
1514 		frame->dev = dev;
1515 		frame->priority = skb->priority;
1516 		rx->skb = frame;
1517 
1518 		payload = frame->data;
1519 		ethertype = (payload[6] << 8) | payload[7];
1520 
1521 		if (likely((compare_ether_addr(payload, rfc1042_header) == 0 &&
1522 			    ethertype != ETH_P_AARP && ethertype != ETH_P_IPX) ||
1523 			   compare_ether_addr(payload,
1524 					      bridge_tunnel_header) == 0)) {
1525 			/* remove RFC1042 or Bridge-Tunnel
1526 			 * encapsulation and replace EtherType */
1527 			skb_pull(frame, 6);
1528 			memcpy(skb_push(frame, ETH_ALEN), src, ETH_ALEN);
1529 			memcpy(skb_push(frame, ETH_ALEN), dst, ETH_ALEN);
1530 		} else {
1531 			memcpy(skb_push(frame, sizeof(__be16)),
1532 			       &len, sizeof(__be16));
1533 			memcpy(skb_push(frame, ETH_ALEN), src, ETH_ALEN);
1534 			memcpy(skb_push(frame, ETH_ALEN), dst, ETH_ALEN);
1535 		}
1536 
1537 		if (!ieee80211_frame_allowed(rx, fc)) {
1538 			if (skb == frame) /* last frame */
1539 				return RX_DROP_UNUSABLE;
1540 			dev_kfree_skb(frame);
1541 			continue;
1542 		}
1543 
1544 		ieee80211_deliver_skb(rx);
1545 	}
1546 
1547 	return RX_QUEUED;
1548 }
1549 
1550 #ifdef CONFIG_MAC80211_MESH
1551 static ieee80211_rx_result
1552 ieee80211_rx_h_mesh_fwding(struct ieee80211_rx_data *rx)
1553 {
1554 	struct ieee80211_hdr *hdr;
1555 	struct ieee80211s_hdr *mesh_hdr;
1556 	unsigned int hdrlen;
1557 	struct sk_buff *skb = rx->skb, *fwd_skb;
1558 
1559 	hdr = (struct ieee80211_hdr *) skb->data;
1560 	hdrlen = ieee80211_hdrlen(hdr->frame_control);
1561 	mesh_hdr = (struct ieee80211s_hdr *) (skb->data + hdrlen);
1562 
1563 	if (!ieee80211_is_data(hdr->frame_control))
1564 		return RX_CONTINUE;
1565 
1566 	if (!mesh_hdr->ttl)
1567 		/* illegal frame */
1568 		return RX_DROP_MONITOR;
1569 
1570 	if (mesh_hdr->flags & MESH_FLAGS_AE_A5_A6){
1571 		struct ieee80211_sub_if_data *sdata;
1572 		struct mesh_path *mppath;
1573 
1574 		sdata = IEEE80211_DEV_TO_SUB_IF(rx->dev);
1575 		rcu_read_lock();
1576 		mppath = mpp_path_lookup(mesh_hdr->eaddr2, sdata);
1577 		if (!mppath) {
1578 			mpp_path_add(mesh_hdr->eaddr2, hdr->addr4, sdata);
1579 		} else {
1580 			spin_lock_bh(&mppath->state_lock);
1581 			mppath->exp_time = jiffies;
1582 			if (compare_ether_addr(mppath->mpp, hdr->addr4) != 0)
1583 				memcpy(mppath->mpp, hdr->addr4, ETH_ALEN);
1584 			spin_unlock_bh(&mppath->state_lock);
1585 		}
1586 		rcu_read_unlock();
1587 	}
1588 
1589 	if (compare_ether_addr(rx->dev->dev_addr, hdr->addr3) == 0)
1590 		return RX_CONTINUE;
1591 
1592 	mesh_hdr->ttl--;
1593 
1594 	if (rx->flags & IEEE80211_RX_RA_MATCH) {
1595 		if (!mesh_hdr->ttl)
1596 			IEEE80211_IFSTA_MESH_CTR_INC(&rx->sdata->u.mesh,
1597 						     dropped_frames_ttl);
1598 		else {
1599 			struct ieee80211_hdr *fwd_hdr;
1600 			fwd_skb = skb_copy(skb, GFP_ATOMIC);
1601 
1602 			if (!fwd_skb && net_ratelimit())
1603 				printk(KERN_DEBUG "%s: failed to clone mesh frame\n",
1604 						   rx->dev->name);
1605 
1606 			fwd_hdr =  (struct ieee80211_hdr *) fwd_skb->data;
1607 			/*
1608 			 * Save TA to addr1 to send TA a path error if a
1609 			 * suitable next hop is not found
1610 			 */
1611 			memcpy(fwd_hdr->addr1, fwd_hdr->addr2, ETH_ALEN);
1612 			memcpy(fwd_hdr->addr2, rx->dev->dev_addr, ETH_ALEN);
1613 			fwd_skb->dev = rx->local->mdev;
1614 			fwd_skb->iif = rx->dev->ifindex;
1615 			dev_queue_xmit(fwd_skb);
1616 		}
1617 	}
1618 
1619 	if (is_multicast_ether_addr(hdr->addr3) ||
1620 	    rx->dev->flags & IFF_PROMISC)
1621 		return RX_CONTINUE;
1622 	else
1623 		return RX_DROP_MONITOR;
1624 }
1625 #endif
1626 
1627 static ieee80211_rx_result debug_noinline
1628 ieee80211_rx_h_data(struct ieee80211_rx_data *rx)
1629 {
1630 	struct net_device *dev = rx->dev;
1631 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
1632 	__le16 fc = hdr->frame_control;
1633 	int err;
1634 
1635 	if (unlikely(!ieee80211_is_data(hdr->frame_control)))
1636 		return RX_CONTINUE;
1637 
1638 	if (unlikely(!ieee80211_is_data_present(hdr->frame_control)))
1639 		return RX_DROP_MONITOR;
1640 
1641 	err = ieee80211_data_to_8023(rx);
1642 	if (unlikely(err))
1643 		return RX_DROP_UNUSABLE;
1644 
1645 	if (!ieee80211_frame_allowed(rx, fc))
1646 		return RX_DROP_MONITOR;
1647 
1648 	rx->skb->dev = dev;
1649 
1650 	dev->stats.rx_packets++;
1651 	dev->stats.rx_bytes += rx->skb->len;
1652 
1653 	ieee80211_deliver_skb(rx);
1654 
1655 	return RX_QUEUED;
1656 }
1657 
1658 static ieee80211_rx_result debug_noinline
1659 ieee80211_rx_h_ctrl(struct ieee80211_rx_data *rx)
1660 {
1661 	struct ieee80211_local *local = rx->local;
1662 	struct ieee80211_hw *hw = &local->hw;
1663 	struct sk_buff *skb = rx->skb;
1664 	struct ieee80211_bar *bar = (struct ieee80211_bar *)skb->data;
1665 	struct tid_ampdu_rx *tid_agg_rx;
1666 	u16 start_seq_num;
1667 	u16 tid;
1668 
1669 	if (likely(!ieee80211_is_ctl(bar->frame_control)))
1670 		return RX_CONTINUE;
1671 
1672 	if (ieee80211_is_back_req(bar->frame_control)) {
1673 		if (!rx->sta)
1674 			return RX_CONTINUE;
1675 		tid = le16_to_cpu(bar->control) >> 12;
1676 		if (rx->sta->ampdu_mlme.tid_state_rx[tid]
1677 					!= HT_AGG_STATE_OPERATIONAL)
1678 			return RX_CONTINUE;
1679 		tid_agg_rx = rx->sta->ampdu_mlme.tid_rx[tid];
1680 
1681 		start_seq_num = le16_to_cpu(bar->start_seq_num) >> 4;
1682 
1683 		/* reset session timer */
1684 		if (tid_agg_rx->timeout)
1685 			mod_timer(&tid_agg_rx->session_timer,
1686 				  TU_TO_EXP_TIME(tid_agg_rx->timeout));
1687 
1688 		/* manage reordering buffer according to requested */
1689 		/* sequence number */
1690 		rcu_read_lock();
1691 		ieee80211_sta_manage_reorder_buf(hw, tid_agg_rx, NULL,
1692 						 start_seq_num, 1);
1693 		rcu_read_unlock();
1694 		return RX_DROP_UNUSABLE;
1695 	}
1696 
1697 	return RX_CONTINUE;
1698 }
1699 
1700 static void ieee80211_process_sa_query_req(struct ieee80211_sub_if_data *sdata,
1701 					   struct ieee80211_mgmt *mgmt,
1702 					   size_t len)
1703 {
1704 	struct ieee80211_local *local = sdata->local;
1705 	struct sk_buff *skb;
1706 	struct ieee80211_mgmt *resp;
1707 
1708 	if (compare_ether_addr(mgmt->da, sdata->dev->dev_addr) != 0) {
1709 		/* Not to own unicast address */
1710 		return;
1711 	}
1712 
1713 	if (compare_ether_addr(mgmt->sa, sdata->u.mgd.bssid) != 0 ||
1714 	    compare_ether_addr(mgmt->bssid, sdata->u.mgd.bssid) != 0) {
1715 		/* Not from the current AP. */
1716 		return;
1717 	}
1718 
1719 	if (sdata->u.mgd.state == IEEE80211_STA_MLME_ASSOCIATE) {
1720 		/* Association in progress; ignore SA Query */
1721 		return;
1722 	}
1723 
1724 	if (len < 24 + 1 + sizeof(resp->u.action.u.sa_query)) {
1725 		/* Too short SA Query request frame */
1726 		return;
1727 	}
1728 
1729 	skb = dev_alloc_skb(sizeof(*resp) + local->hw.extra_tx_headroom);
1730 	if (skb == NULL)
1731 		return;
1732 
1733 	skb_reserve(skb, local->hw.extra_tx_headroom);
1734 	resp = (struct ieee80211_mgmt *) skb_put(skb, 24);
1735 	memset(resp, 0, 24);
1736 	memcpy(resp->da, mgmt->sa, ETH_ALEN);
1737 	memcpy(resp->sa, sdata->dev->dev_addr, ETH_ALEN);
1738 	memcpy(resp->bssid, sdata->u.mgd.bssid, ETH_ALEN);
1739 	resp->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
1740 					  IEEE80211_STYPE_ACTION);
1741 	skb_put(skb, 1 + sizeof(resp->u.action.u.sa_query));
1742 	resp->u.action.category = WLAN_CATEGORY_SA_QUERY;
1743 	resp->u.action.u.sa_query.action = WLAN_ACTION_SA_QUERY_RESPONSE;
1744 	memcpy(resp->u.action.u.sa_query.trans_id,
1745 	       mgmt->u.action.u.sa_query.trans_id,
1746 	       WLAN_SA_QUERY_TR_ID_LEN);
1747 
1748 	ieee80211_tx_skb(sdata, skb, 1);
1749 }
1750 
1751 static ieee80211_rx_result debug_noinline
1752 ieee80211_rx_h_action(struct ieee80211_rx_data *rx)
1753 {
1754 	struct ieee80211_local *local = rx->local;
1755 	struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(rx->dev);
1756 	struct ieee80211_mgmt *mgmt = (struct ieee80211_mgmt *) rx->skb->data;
1757 	struct ieee80211_bss *bss;
1758 	int len = rx->skb->len;
1759 
1760 	if (!ieee80211_is_action(mgmt->frame_control))
1761 		return RX_CONTINUE;
1762 
1763 	if (!rx->sta)
1764 		return RX_DROP_MONITOR;
1765 
1766 	if (!(rx->flags & IEEE80211_RX_RA_MATCH))
1767 		return RX_DROP_MONITOR;
1768 
1769 	if (ieee80211_drop_unencrypted(rx, mgmt->frame_control))
1770 		return RX_DROP_MONITOR;
1771 
1772 	/* all categories we currently handle have action_code */
1773 	if (len < IEEE80211_MIN_ACTION_SIZE + 1)
1774 		return RX_DROP_MONITOR;
1775 
1776 	switch (mgmt->u.action.category) {
1777 	case WLAN_CATEGORY_BACK:
1778 		/*
1779 		 * The aggregation code is not prepared to handle
1780 		 * anything but STA/AP due to the BSSID handling;
1781 		 * IBSS could work in the code but isn't supported
1782 		 * by drivers or the standard.
1783 		 */
1784 		if (sdata->vif.type != NL80211_IFTYPE_STATION &&
1785 		    sdata->vif.type != NL80211_IFTYPE_AP_VLAN &&
1786 		    sdata->vif.type != NL80211_IFTYPE_AP)
1787 			return RX_DROP_MONITOR;
1788 
1789 		switch (mgmt->u.action.u.addba_req.action_code) {
1790 		case WLAN_ACTION_ADDBA_REQ:
1791 			if (len < (IEEE80211_MIN_ACTION_SIZE +
1792 				   sizeof(mgmt->u.action.u.addba_req)))
1793 				return RX_DROP_MONITOR;
1794 			ieee80211_process_addba_request(local, rx->sta, mgmt, len);
1795 			break;
1796 		case WLAN_ACTION_ADDBA_RESP:
1797 			if (len < (IEEE80211_MIN_ACTION_SIZE +
1798 				   sizeof(mgmt->u.action.u.addba_resp)))
1799 				return RX_DROP_MONITOR;
1800 			ieee80211_process_addba_resp(local, rx->sta, mgmt, len);
1801 			break;
1802 		case WLAN_ACTION_DELBA:
1803 			if (len < (IEEE80211_MIN_ACTION_SIZE +
1804 				   sizeof(mgmt->u.action.u.delba)))
1805 				return RX_DROP_MONITOR;
1806 			ieee80211_process_delba(sdata, rx->sta, mgmt, len);
1807 			break;
1808 		}
1809 		break;
1810 	case WLAN_CATEGORY_SPECTRUM_MGMT:
1811 		if (local->hw.conf.channel->band != IEEE80211_BAND_5GHZ)
1812 			return RX_DROP_MONITOR;
1813 
1814 		if (sdata->vif.type != NL80211_IFTYPE_STATION)
1815 			return RX_DROP_MONITOR;
1816 
1817 		switch (mgmt->u.action.u.measurement.action_code) {
1818 		case WLAN_ACTION_SPCT_MSR_REQ:
1819 			if (len < (IEEE80211_MIN_ACTION_SIZE +
1820 				   sizeof(mgmt->u.action.u.measurement)))
1821 				return RX_DROP_MONITOR;
1822 			ieee80211_process_measurement_req(sdata, mgmt, len);
1823 			break;
1824 		case WLAN_ACTION_SPCT_CHL_SWITCH:
1825 			if (len < (IEEE80211_MIN_ACTION_SIZE +
1826 				   sizeof(mgmt->u.action.u.chan_switch)))
1827 				return RX_DROP_MONITOR;
1828 
1829 			if (memcmp(mgmt->bssid, sdata->u.mgd.bssid, ETH_ALEN))
1830 				return RX_DROP_MONITOR;
1831 
1832 			bss = ieee80211_rx_bss_get(local, sdata->u.mgd.bssid,
1833 					   local->hw.conf.channel->center_freq,
1834 					   sdata->u.mgd.ssid,
1835 					   sdata->u.mgd.ssid_len);
1836 			if (!bss)
1837 				return RX_DROP_MONITOR;
1838 
1839 			ieee80211_process_chanswitch(sdata,
1840 				     &mgmt->u.action.u.chan_switch.sw_elem, bss);
1841 			ieee80211_rx_bss_put(local, bss);
1842 			break;
1843 		}
1844 		break;
1845 	case WLAN_CATEGORY_SA_QUERY:
1846 		if (len < (IEEE80211_MIN_ACTION_SIZE +
1847 			   sizeof(mgmt->u.action.u.sa_query)))
1848 			return RX_DROP_MONITOR;
1849 		switch (mgmt->u.action.u.sa_query.action) {
1850 		case WLAN_ACTION_SA_QUERY_REQUEST:
1851 			if (sdata->vif.type != NL80211_IFTYPE_STATION)
1852 				return RX_DROP_MONITOR;
1853 			ieee80211_process_sa_query_req(sdata, mgmt, len);
1854 			break;
1855 		case WLAN_ACTION_SA_QUERY_RESPONSE:
1856 			/*
1857 			 * SA Query response is currently only used in AP mode
1858 			 * and it is processed in user space.
1859 			 */
1860 			return RX_CONTINUE;
1861 		}
1862 		break;
1863 	default:
1864 		return RX_CONTINUE;
1865 	}
1866 
1867 	rx->sta->rx_packets++;
1868 	dev_kfree_skb(rx->skb);
1869 	return RX_QUEUED;
1870 }
1871 
1872 static ieee80211_rx_result debug_noinline
1873 ieee80211_rx_h_mgmt(struct ieee80211_rx_data *rx)
1874 {
1875 	struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(rx->dev);
1876 	struct ieee80211_mgmt *mgmt = (struct ieee80211_mgmt *) rx->skb->data;
1877 
1878 	if (!(rx->flags & IEEE80211_RX_RA_MATCH))
1879 		return RX_DROP_MONITOR;
1880 
1881 	if (ieee80211_drop_unencrypted(rx, mgmt->frame_control))
1882 		return RX_DROP_MONITOR;
1883 
1884 	if (ieee80211_vif_is_mesh(&sdata->vif))
1885 		return ieee80211_mesh_rx_mgmt(sdata, rx->skb, rx->status);
1886 
1887 	if (sdata->vif.type == NL80211_IFTYPE_ADHOC)
1888 		return ieee80211_ibss_rx_mgmt(sdata, rx->skb, rx->status);
1889 
1890 	if (sdata->vif.type == NL80211_IFTYPE_STATION)
1891 		return ieee80211_sta_rx_mgmt(sdata, rx->skb, rx->status);
1892 
1893 	return RX_DROP_MONITOR;
1894 }
1895 
1896 static void ieee80211_rx_michael_mic_report(struct net_device *dev,
1897 					    struct ieee80211_hdr *hdr,
1898 					    struct ieee80211_rx_data *rx)
1899 {
1900 	int keyidx;
1901 	unsigned int hdrlen;
1902 
1903 	hdrlen = ieee80211_hdrlen(hdr->frame_control);
1904 	if (rx->skb->len >= hdrlen + 4)
1905 		keyidx = rx->skb->data[hdrlen + 3] >> 6;
1906 	else
1907 		keyidx = -1;
1908 
1909 	if (!rx->sta) {
1910 		/*
1911 		 * Some hardware seem to generate incorrect Michael MIC
1912 		 * reports; ignore them to avoid triggering countermeasures.
1913 		 */
1914 		goto ignore;
1915 	}
1916 
1917 	if (!ieee80211_has_protected(hdr->frame_control))
1918 		goto ignore;
1919 
1920 	if (rx->sdata->vif.type == NL80211_IFTYPE_AP && keyidx) {
1921 		/*
1922 		 * APs with pairwise keys should never receive Michael MIC
1923 		 * errors for non-zero keyidx because these are reserved for
1924 		 * group keys and only the AP is sending real multicast
1925 		 * frames in the BSS.
1926 		 */
1927 		goto ignore;
1928 	}
1929 
1930 	if (!ieee80211_is_data(hdr->frame_control) &&
1931 	    !ieee80211_is_auth(hdr->frame_control))
1932 		goto ignore;
1933 
1934 	mac80211_ev_michael_mic_failure(rx->sdata, keyidx, hdr);
1935  ignore:
1936 	dev_kfree_skb(rx->skb);
1937 	rx->skb = NULL;
1938 }
1939 
1940 /* TODO: use IEEE80211_RX_FRAGMENTED */
1941 static void ieee80211_rx_cooked_monitor(struct ieee80211_rx_data *rx)
1942 {
1943 	struct ieee80211_sub_if_data *sdata;
1944 	struct ieee80211_local *local = rx->local;
1945 	struct ieee80211_rtap_hdr {
1946 		struct ieee80211_radiotap_header hdr;
1947 		u8 flags;
1948 		u8 rate;
1949 		__le16 chan_freq;
1950 		__le16 chan_flags;
1951 	} __attribute__ ((packed)) *rthdr;
1952 	struct sk_buff *skb = rx->skb, *skb2;
1953 	struct net_device *prev_dev = NULL;
1954 	struct ieee80211_rx_status *status = rx->status;
1955 
1956 	if (rx->flags & IEEE80211_RX_CMNTR_REPORTED)
1957 		goto out_free_skb;
1958 
1959 	if (skb_headroom(skb) < sizeof(*rthdr) &&
1960 	    pskb_expand_head(skb, sizeof(*rthdr), 0, GFP_ATOMIC))
1961 		goto out_free_skb;
1962 
1963 	rthdr = (void *)skb_push(skb, sizeof(*rthdr));
1964 	memset(rthdr, 0, sizeof(*rthdr));
1965 	rthdr->hdr.it_len = cpu_to_le16(sizeof(*rthdr));
1966 	rthdr->hdr.it_present =
1967 		cpu_to_le32((1 << IEEE80211_RADIOTAP_FLAGS) |
1968 			    (1 << IEEE80211_RADIOTAP_RATE) |
1969 			    (1 << IEEE80211_RADIOTAP_CHANNEL));
1970 
1971 	rthdr->rate = rx->rate->bitrate / 5;
1972 	rthdr->chan_freq = cpu_to_le16(status->freq);
1973 
1974 	if (status->band == IEEE80211_BAND_5GHZ)
1975 		rthdr->chan_flags = cpu_to_le16(IEEE80211_CHAN_OFDM |
1976 						IEEE80211_CHAN_5GHZ);
1977 	else
1978 		rthdr->chan_flags = cpu_to_le16(IEEE80211_CHAN_DYN |
1979 						IEEE80211_CHAN_2GHZ);
1980 
1981 	skb_set_mac_header(skb, 0);
1982 	skb->ip_summed = CHECKSUM_UNNECESSARY;
1983 	skb->pkt_type = PACKET_OTHERHOST;
1984 	skb->protocol = htons(ETH_P_802_2);
1985 
1986 	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
1987 		if (!netif_running(sdata->dev))
1988 			continue;
1989 
1990 		if (sdata->vif.type != NL80211_IFTYPE_MONITOR ||
1991 		    !(sdata->u.mntr_flags & MONITOR_FLAG_COOK_FRAMES))
1992 			continue;
1993 
1994 		if (prev_dev) {
1995 			skb2 = skb_clone(skb, GFP_ATOMIC);
1996 			if (skb2) {
1997 				skb2->dev = prev_dev;
1998 				netif_rx(skb2);
1999 			}
2000 		}
2001 
2002 		prev_dev = sdata->dev;
2003 		sdata->dev->stats.rx_packets++;
2004 		sdata->dev->stats.rx_bytes += skb->len;
2005 	}
2006 
2007 	if (prev_dev) {
2008 		skb->dev = prev_dev;
2009 		netif_rx(skb);
2010 		skb = NULL;
2011 	} else
2012 		goto out_free_skb;
2013 
2014 	rx->flags |= IEEE80211_RX_CMNTR_REPORTED;
2015 	return;
2016 
2017  out_free_skb:
2018 	dev_kfree_skb(skb);
2019 }
2020 
2021 
2022 static void ieee80211_invoke_rx_handlers(struct ieee80211_sub_if_data *sdata,
2023 					 struct ieee80211_rx_data *rx,
2024 					 struct sk_buff *skb)
2025 {
2026 	ieee80211_rx_result res = RX_DROP_MONITOR;
2027 
2028 	rx->skb = skb;
2029 	rx->sdata = sdata;
2030 	rx->dev = sdata->dev;
2031 
2032 #define CALL_RXH(rxh)			\
2033 	do {				\
2034 		res = rxh(rx);		\
2035 		if (res != RX_CONTINUE)	\
2036 			goto rxh_done;  \
2037 	} while (0);
2038 
2039 	CALL_RXH(ieee80211_rx_h_passive_scan)
2040 	CALL_RXH(ieee80211_rx_h_check)
2041 	CALL_RXH(ieee80211_rx_h_decrypt)
2042 	CALL_RXH(ieee80211_rx_h_check_more_data)
2043 	CALL_RXH(ieee80211_rx_h_sta_process)
2044 	CALL_RXH(ieee80211_rx_h_defragment)
2045 	CALL_RXH(ieee80211_rx_h_ps_poll)
2046 	CALL_RXH(ieee80211_rx_h_michael_mic_verify)
2047 	/* must be after MMIC verify so header is counted in MPDU mic */
2048 	CALL_RXH(ieee80211_rx_h_remove_qos_control)
2049 	CALL_RXH(ieee80211_rx_h_amsdu)
2050 #ifdef CONFIG_MAC80211_MESH
2051 	if (ieee80211_vif_is_mesh(&sdata->vif))
2052 		CALL_RXH(ieee80211_rx_h_mesh_fwding);
2053 #endif
2054 	CALL_RXH(ieee80211_rx_h_data)
2055 	CALL_RXH(ieee80211_rx_h_ctrl)
2056 	CALL_RXH(ieee80211_rx_h_action)
2057 	CALL_RXH(ieee80211_rx_h_mgmt)
2058 
2059 #undef CALL_RXH
2060 
2061  rxh_done:
2062 	switch (res) {
2063 	case RX_DROP_MONITOR:
2064 		I802_DEBUG_INC(sdata->local->rx_handlers_drop);
2065 		if (rx->sta)
2066 			rx->sta->rx_dropped++;
2067 		/* fall through */
2068 	case RX_CONTINUE:
2069 		ieee80211_rx_cooked_monitor(rx);
2070 		break;
2071 	case RX_DROP_UNUSABLE:
2072 		I802_DEBUG_INC(sdata->local->rx_handlers_drop);
2073 		if (rx->sta)
2074 			rx->sta->rx_dropped++;
2075 		dev_kfree_skb(rx->skb);
2076 		break;
2077 	case RX_QUEUED:
2078 		I802_DEBUG_INC(sdata->local->rx_handlers_queued);
2079 		break;
2080 	}
2081 }
2082 
2083 /* main receive path */
2084 
2085 static int prepare_for_handlers(struct ieee80211_sub_if_data *sdata,
2086 				struct ieee80211_rx_data *rx,
2087 				struct ieee80211_hdr *hdr)
2088 {
2089 	u8 *bssid = ieee80211_get_bssid(hdr, rx->skb->len, sdata->vif.type);
2090 	int multicast = is_multicast_ether_addr(hdr->addr1);
2091 
2092 	switch (sdata->vif.type) {
2093 	case NL80211_IFTYPE_STATION:
2094 		if (!bssid)
2095 			return 0;
2096 		if (!ieee80211_bssid_match(bssid, sdata->u.mgd.bssid)) {
2097 			if (!(rx->flags & IEEE80211_RX_IN_SCAN))
2098 				return 0;
2099 			rx->flags &= ~IEEE80211_RX_RA_MATCH;
2100 		} else if (!multicast &&
2101 			   compare_ether_addr(sdata->dev->dev_addr,
2102 					      hdr->addr1) != 0) {
2103 			if (!(sdata->dev->flags & IFF_PROMISC))
2104 				return 0;
2105 			rx->flags &= ~IEEE80211_RX_RA_MATCH;
2106 		}
2107 		break;
2108 	case NL80211_IFTYPE_ADHOC:
2109 		if (!bssid)
2110 			return 0;
2111 		if (ieee80211_is_beacon(hdr->frame_control)) {
2112 			return 1;
2113 		}
2114 		else if (!ieee80211_bssid_match(bssid, sdata->u.ibss.bssid)) {
2115 			if (!(rx->flags & IEEE80211_RX_IN_SCAN))
2116 				return 0;
2117 			rx->flags &= ~IEEE80211_RX_RA_MATCH;
2118 		} else if (!multicast &&
2119 			   compare_ether_addr(sdata->dev->dev_addr,
2120 					      hdr->addr1) != 0) {
2121 			if (!(sdata->dev->flags & IFF_PROMISC))
2122 				return 0;
2123 			rx->flags &= ~IEEE80211_RX_RA_MATCH;
2124 		} else if (!rx->sta) {
2125 			int rate_idx;
2126 			if (rx->status->flag & RX_FLAG_HT)
2127 				rate_idx = 0; /* TODO: HT rates */
2128 			else
2129 				rate_idx = rx->status->rate_idx;
2130 			rx->sta = ieee80211_ibss_add_sta(sdata, bssid, hdr->addr2,
2131 				BIT(rate_idx));
2132 		}
2133 		break;
2134 	case NL80211_IFTYPE_MESH_POINT:
2135 		if (!multicast &&
2136 		    compare_ether_addr(sdata->dev->dev_addr,
2137 				       hdr->addr1) != 0) {
2138 			if (!(sdata->dev->flags & IFF_PROMISC))
2139 				return 0;
2140 
2141 			rx->flags &= ~IEEE80211_RX_RA_MATCH;
2142 		}
2143 		break;
2144 	case NL80211_IFTYPE_AP_VLAN:
2145 	case NL80211_IFTYPE_AP:
2146 		if (!bssid) {
2147 			if (compare_ether_addr(sdata->dev->dev_addr,
2148 					       hdr->addr1))
2149 				return 0;
2150 		} else if (!ieee80211_bssid_match(bssid,
2151 					sdata->dev->dev_addr)) {
2152 			if (!(rx->flags & IEEE80211_RX_IN_SCAN))
2153 				return 0;
2154 			rx->flags &= ~IEEE80211_RX_RA_MATCH;
2155 		}
2156 		break;
2157 	case NL80211_IFTYPE_WDS:
2158 		if (bssid || !ieee80211_is_data(hdr->frame_control))
2159 			return 0;
2160 		if (compare_ether_addr(sdata->u.wds.remote_addr, hdr->addr2))
2161 			return 0;
2162 		break;
2163 	case NL80211_IFTYPE_MONITOR:
2164 		/* take everything */
2165 		break;
2166 	case NL80211_IFTYPE_UNSPECIFIED:
2167 	case __NL80211_IFTYPE_AFTER_LAST:
2168 		/* should never get here */
2169 		WARN_ON(1);
2170 		break;
2171 	}
2172 
2173 	return 1;
2174 }
2175 
2176 /*
2177  * This is the actual Rx frames handler. as it blongs to Rx path it must
2178  * be called with rcu_read_lock protection.
2179  */
2180 static void __ieee80211_rx_handle_packet(struct ieee80211_hw *hw,
2181 					 struct sk_buff *skb,
2182 					 struct ieee80211_rx_status *status,
2183 					 struct ieee80211_rate *rate)
2184 {
2185 	struct ieee80211_local *local = hw_to_local(hw);
2186 	struct ieee80211_sub_if_data *sdata;
2187 	struct ieee80211_hdr *hdr;
2188 	struct ieee80211_rx_data rx;
2189 	int prepares;
2190 	struct ieee80211_sub_if_data *prev = NULL;
2191 	struct sk_buff *skb_new;
2192 
2193 	hdr = (struct ieee80211_hdr *)skb->data;
2194 	memset(&rx, 0, sizeof(rx));
2195 	rx.skb = skb;
2196 	rx.local = local;
2197 
2198 	rx.status = status;
2199 	rx.rate = rate;
2200 
2201 	if (ieee80211_is_data(hdr->frame_control) || ieee80211_is_mgmt(hdr->frame_control))
2202 		local->dot11ReceivedFragmentCount++;
2203 
2204 	rx.sta = sta_info_get(local, hdr->addr2);
2205 	if (rx.sta) {
2206 		rx.sdata = rx.sta->sdata;
2207 		rx.dev = rx.sta->sdata->dev;
2208 	}
2209 
2210 	if ((status->flag & RX_FLAG_MMIC_ERROR)) {
2211 		ieee80211_rx_michael_mic_report(local->mdev, hdr, &rx);
2212 		return;
2213 	}
2214 
2215 	if (unlikely(local->sw_scanning || local->hw_scanning))
2216 		rx.flags |= IEEE80211_RX_IN_SCAN;
2217 
2218 	ieee80211_parse_qos(&rx);
2219 	ieee80211_verify_alignment(&rx);
2220 
2221 	skb = rx.skb;
2222 
2223 	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
2224 		if (!netif_running(sdata->dev))
2225 			continue;
2226 
2227 		if (sdata->vif.type == NL80211_IFTYPE_MONITOR)
2228 			continue;
2229 
2230 		rx.flags |= IEEE80211_RX_RA_MATCH;
2231 		prepares = prepare_for_handlers(sdata, &rx, hdr);
2232 
2233 		if (!prepares)
2234 			continue;
2235 
2236 		/*
2237 		 * frame is destined for this interface, but if it's not
2238 		 * also for the previous one we handle that after the
2239 		 * loop to avoid copying the SKB once too much
2240 		 */
2241 
2242 		if (!prev) {
2243 			prev = sdata;
2244 			continue;
2245 		}
2246 
2247 		/*
2248 		 * frame was destined for the previous interface
2249 		 * so invoke RX handlers for it
2250 		 */
2251 
2252 		skb_new = skb_copy(skb, GFP_ATOMIC);
2253 		if (!skb_new) {
2254 			if (net_ratelimit())
2255 				printk(KERN_DEBUG "%s: failed to copy "
2256 				       "multicast frame for %s\n",
2257 				       wiphy_name(local->hw.wiphy),
2258 				       prev->dev->name);
2259 			continue;
2260 		}
2261 		ieee80211_invoke_rx_handlers(prev, &rx, skb_new);
2262 		prev = sdata;
2263 	}
2264 	if (prev)
2265 		ieee80211_invoke_rx_handlers(prev, &rx, skb);
2266 	else
2267 		dev_kfree_skb(skb);
2268 }
2269 
2270 #define SEQ_MODULO 0x1000
2271 #define SEQ_MASK   0xfff
2272 
2273 static inline int seq_less(u16 sq1, u16 sq2)
2274 {
2275 	return ((sq1 - sq2) & SEQ_MASK) > (SEQ_MODULO >> 1);
2276 }
2277 
2278 static inline u16 seq_inc(u16 sq)
2279 {
2280 	return (sq + 1) & SEQ_MASK;
2281 }
2282 
2283 static inline u16 seq_sub(u16 sq1, u16 sq2)
2284 {
2285 	return (sq1 - sq2) & SEQ_MASK;
2286 }
2287 
2288 
2289 /*
2290  * As it function blongs to Rx path it must be called with
2291  * the proper rcu_read_lock protection for its flow.
2292  */
2293 static u8 ieee80211_sta_manage_reorder_buf(struct ieee80211_hw *hw,
2294 					   struct tid_ampdu_rx *tid_agg_rx,
2295 					   struct sk_buff *skb,
2296 					   u16 mpdu_seq_num,
2297 					   int bar_req)
2298 {
2299 	struct ieee80211_local *local = hw_to_local(hw);
2300 	struct ieee80211_rx_status status;
2301 	u16 head_seq_num, buf_size;
2302 	int index;
2303 	struct ieee80211_supported_band *sband;
2304 	struct ieee80211_rate *rate;
2305 
2306 	buf_size = tid_agg_rx->buf_size;
2307 	head_seq_num = tid_agg_rx->head_seq_num;
2308 
2309 	/* frame with out of date sequence number */
2310 	if (seq_less(mpdu_seq_num, head_seq_num)) {
2311 		dev_kfree_skb(skb);
2312 		return 1;
2313 	}
2314 
2315 	/* if frame sequence number exceeds our buffering window size or
2316 	 * block Ack Request arrived - release stored frames */
2317 	if ((!seq_less(mpdu_seq_num, head_seq_num + buf_size)) || (bar_req)) {
2318 		/* new head to the ordering buffer */
2319 		if (bar_req)
2320 			head_seq_num = mpdu_seq_num;
2321 		else
2322 			head_seq_num =
2323 				seq_inc(seq_sub(mpdu_seq_num, buf_size));
2324 		/* release stored frames up to new head to stack */
2325 		while (seq_less(tid_agg_rx->head_seq_num, head_seq_num)) {
2326 			index = seq_sub(tid_agg_rx->head_seq_num,
2327 				tid_agg_rx->ssn)
2328 				% tid_agg_rx->buf_size;
2329 
2330 			if (tid_agg_rx->reorder_buf[index]) {
2331 				/* release the reordered frames to stack */
2332 				memcpy(&status,
2333 					tid_agg_rx->reorder_buf[index]->cb,
2334 					sizeof(status));
2335 				sband = local->hw.wiphy->bands[status.band];
2336 				if (status.flag & RX_FLAG_HT) {
2337 					/* TODO: HT rates */
2338 					rate = sband->bitrates;
2339 				} else {
2340 					rate = &sband->bitrates
2341 						[status.rate_idx];
2342 				}
2343 				__ieee80211_rx_handle_packet(hw,
2344 					tid_agg_rx->reorder_buf[index],
2345 					&status, rate);
2346 				tid_agg_rx->stored_mpdu_num--;
2347 				tid_agg_rx->reorder_buf[index] = NULL;
2348 			}
2349 			tid_agg_rx->head_seq_num =
2350 				seq_inc(tid_agg_rx->head_seq_num);
2351 		}
2352 		if (bar_req)
2353 			return 1;
2354 	}
2355 
2356 	/* now the new frame is always in the range of the reordering */
2357 	/* buffer window */
2358 	index = seq_sub(mpdu_seq_num, tid_agg_rx->ssn)
2359 				% tid_agg_rx->buf_size;
2360 	/* check if we already stored this frame */
2361 	if (tid_agg_rx->reorder_buf[index]) {
2362 		dev_kfree_skb(skb);
2363 		return 1;
2364 	}
2365 
2366 	/* if arrived mpdu is in the right order and nothing else stored */
2367 	/* release it immediately */
2368 	if (mpdu_seq_num == tid_agg_rx->head_seq_num &&
2369 			tid_agg_rx->stored_mpdu_num == 0) {
2370 		tid_agg_rx->head_seq_num =
2371 			seq_inc(tid_agg_rx->head_seq_num);
2372 		return 0;
2373 	}
2374 
2375 	/* put the frame in the reordering buffer */
2376 	tid_agg_rx->reorder_buf[index] = skb;
2377 	tid_agg_rx->stored_mpdu_num++;
2378 	/* release the buffer until next missing frame */
2379 	index = seq_sub(tid_agg_rx->head_seq_num, tid_agg_rx->ssn)
2380 						% tid_agg_rx->buf_size;
2381 	while (tid_agg_rx->reorder_buf[index]) {
2382 		/* release the reordered frame back to stack */
2383 		memcpy(&status, tid_agg_rx->reorder_buf[index]->cb,
2384 			sizeof(status));
2385 		sband = local->hw.wiphy->bands[status.band];
2386 		if (status.flag & RX_FLAG_HT)
2387 			rate = sband->bitrates; /* TODO: HT rates */
2388 		else
2389 			rate = &sband->bitrates[status.rate_idx];
2390 		__ieee80211_rx_handle_packet(hw, tid_agg_rx->reorder_buf[index],
2391 					     &status, rate);
2392 		tid_agg_rx->stored_mpdu_num--;
2393 		tid_agg_rx->reorder_buf[index] = NULL;
2394 		tid_agg_rx->head_seq_num = seq_inc(tid_agg_rx->head_seq_num);
2395 		index =	seq_sub(tid_agg_rx->head_seq_num,
2396 			tid_agg_rx->ssn) % tid_agg_rx->buf_size;
2397 	}
2398 	return 1;
2399 }
2400 
2401 static u8 ieee80211_rx_reorder_ampdu(struct ieee80211_local *local,
2402 				     struct sk_buff *skb)
2403 {
2404 	struct ieee80211_hw *hw = &local->hw;
2405 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
2406 	struct sta_info *sta;
2407 	struct tid_ampdu_rx *tid_agg_rx;
2408 	u16 sc;
2409 	u16 mpdu_seq_num;
2410 	u8 ret = 0;
2411 	int tid;
2412 
2413 	sta = sta_info_get(local, hdr->addr2);
2414 	if (!sta)
2415 		return ret;
2416 
2417 	/* filter the QoS data rx stream according to
2418 	 * STA/TID and check if this STA/TID is on aggregation */
2419 	if (!ieee80211_is_data_qos(hdr->frame_control))
2420 		goto end_reorder;
2421 
2422 	tid = *ieee80211_get_qos_ctl(hdr) & IEEE80211_QOS_CTL_TID_MASK;
2423 
2424 	if (sta->ampdu_mlme.tid_state_rx[tid] != HT_AGG_STATE_OPERATIONAL)
2425 		goto end_reorder;
2426 
2427 	tid_agg_rx = sta->ampdu_mlme.tid_rx[tid];
2428 
2429 	/* qos null data frames are excluded */
2430 	if (unlikely(hdr->frame_control & cpu_to_le16(IEEE80211_STYPE_NULLFUNC)))
2431 		goto end_reorder;
2432 
2433 	/* new un-ordered ampdu frame - process it */
2434 
2435 	/* reset session timer */
2436 	if (tid_agg_rx->timeout)
2437 		mod_timer(&tid_agg_rx->session_timer,
2438 			  TU_TO_EXP_TIME(tid_agg_rx->timeout));
2439 
2440 	/* if this mpdu is fragmented - terminate rx aggregation session */
2441 	sc = le16_to_cpu(hdr->seq_ctrl);
2442 	if (sc & IEEE80211_SCTL_FRAG) {
2443 		ieee80211_sta_stop_rx_ba_session(sta->sdata, sta->sta.addr,
2444 			tid, 0, WLAN_REASON_QSTA_REQUIRE_SETUP);
2445 		ret = 1;
2446 		goto end_reorder;
2447 	}
2448 
2449 	/* according to mpdu sequence number deal with reordering buffer */
2450 	mpdu_seq_num = (sc & IEEE80211_SCTL_SEQ) >> 4;
2451 	ret = ieee80211_sta_manage_reorder_buf(hw, tid_agg_rx, skb,
2452 						mpdu_seq_num, 0);
2453  end_reorder:
2454 	return ret;
2455 }
2456 
2457 /*
2458  * This is the receive path handler. It is called by a low level driver when an
2459  * 802.11 MPDU is received from the hardware.
2460  */
2461 void __ieee80211_rx(struct ieee80211_hw *hw, struct sk_buff *skb,
2462 		    struct ieee80211_rx_status *status)
2463 {
2464 	struct ieee80211_local *local = hw_to_local(hw);
2465 	struct ieee80211_rate *rate = NULL;
2466 	struct ieee80211_supported_band *sband;
2467 
2468 	if (status->band < 0 ||
2469 	    status->band >= IEEE80211_NUM_BANDS) {
2470 		WARN_ON(1);
2471 		return;
2472 	}
2473 
2474 	sband = local->hw.wiphy->bands[status->band];
2475 	if (!sband) {
2476 		WARN_ON(1);
2477 		return;
2478 	}
2479 
2480 	if (status->flag & RX_FLAG_HT) {
2481 		/* rate_idx is MCS index */
2482 		if (WARN_ON(status->rate_idx < 0 ||
2483 			    status->rate_idx >= 76))
2484 			return;
2485 		/* HT rates are not in the table - use the highest legacy rate
2486 		 * for now since other parts of mac80211 may not yet be fully
2487 		 * MCS aware. */
2488 		rate = &sband->bitrates[sband->n_bitrates - 1];
2489 	} else {
2490 		if (WARN_ON(status->rate_idx < 0 ||
2491 			    status->rate_idx >= sband->n_bitrates))
2492 			return;
2493 		rate = &sband->bitrates[status->rate_idx];
2494 	}
2495 
2496 	/*
2497 	 * key references and virtual interfaces are protected using RCU
2498 	 * and this requires that we are in a read-side RCU section during
2499 	 * receive processing
2500 	 */
2501 	rcu_read_lock();
2502 
2503 	/*
2504 	 * Frames with failed FCS/PLCP checksum are not returned,
2505 	 * all other frames are returned without radiotap header
2506 	 * if it was previously present.
2507 	 * Also, frames with less than 16 bytes are dropped.
2508 	 */
2509 	skb = ieee80211_rx_monitor(local, skb, status, rate);
2510 	if (!skb) {
2511 		rcu_read_unlock();
2512 		return;
2513 	}
2514 
2515 	if (!ieee80211_rx_reorder_ampdu(local, skb))
2516 		__ieee80211_rx_handle_packet(hw, skb, status, rate);
2517 
2518 	rcu_read_unlock();
2519 }
2520 EXPORT_SYMBOL(__ieee80211_rx);
2521 
2522 /* This is a version of the rx handler that can be called from hard irq
2523  * context. Post the skb on the queue and schedule the tasklet */
2524 void ieee80211_rx_irqsafe(struct ieee80211_hw *hw, struct sk_buff *skb,
2525 			  struct ieee80211_rx_status *status)
2526 {
2527 	struct ieee80211_local *local = hw_to_local(hw);
2528 
2529 	BUILD_BUG_ON(sizeof(struct ieee80211_rx_status) > sizeof(skb->cb));
2530 
2531 	skb->dev = local->mdev;
2532 	/* copy status into skb->cb for use by tasklet */
2533 	memcpy(skb->cb, status, sizeof(*status));
2534 	skb->pkt_type = IEEE80211_RX_MSG;
2535 	skb_queue_tail(&local->skb_queue, skb);
2536 	tasklet_schedule(&local->tasklet);
2537 }
2538 EXPORT_SYMBOL(ieee80211_rx_irqsafe);
2539