xref: /openbmc/linux/net/mac80211/rx.c (revision b04b4f78)
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 					   struct ieee80211_rx_status *status,
33 					   u16 mpdu_seq_num,
34 					   int bar_req);
35 /*
36  * monitor mode reception
37  *
38  * This function cleans up the SKB, i.e. it removes all the stuff
39  * only useful for monitoring.
40  */
41 static struct sk_buff *remove_monitor_info(struct ieee80211_local *local,
42 					   struct sk_buff *skb,
43 					   int rtap_len)
44 {
45 	skb_pull(skb, rtap_len);
46 
47 	if (local->hw.flags & IEEE80211_HW_RX_INCLUDES_FCS) {
48 		if (likely(skb->len > FCS_LEN))
49 			skb_trim(skb, skb->len - FCS_LEN);
50 		else {
51 			/* driver bug */
52 			WARN_ON(1);
53 			dev_kfree_skb(skb);
54 			skb = NULL;
55 		}
56 	}
57 
58 	return skb;
59 }
60 
61 static inline int should_drop_frame(struct ieee80211_rx_status *status,
62 				    struct sk_buff *skb,
63 				    int present_fcs_len,
64 				    int radiotap_len)
65 {
66 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
67 
68 	if (status->flag & (RX_FLAG_FAILED_FCS_CRC | RX_FLAG_FAILED_PLCP_CRC))
69 		return 1;
70 	if (unlikely(skb->len < 16 + present_fcs_len + radiotap_len))
71 		return 1;
72 	if (ieee80211_is_ctl(hdr->frame_control) &&
73 	    !ieee80211_is_pspoll(hdr->frame_control) &&
74 	    !ieee80211_is_back_req(hdr->frame_control))
75 		return 1;
76 	return 0;
77 }
78 
79 static int
80 ieee80211_rx_radiotap_len(struct ieee80211_local *local,
81 			  struct ieee80211_rx_status *status)
82 {
83 	int len;
84 
85 	/* always present fields */
86 	len = sizeof(struct ieee80211_radiotap_header) + 9;
87 
88 	if (status->flag & RX_FLAG_TSFT)
89 		len += 8;
90 	if (local->hw.flags & IEEE80211_HW_SIGNAL_DBM)
91 		len += 1;
92 	if (local->hw.flags & IEEE80211_HW_NOISE_DBM)
93 		len += 1;
94 
95 	if (len & 1) /* padding for RX_FLAGS if necessary */
96 		len++;
97 
98 	/* make sure radiotap starts at a naturally aligned address */
99 	if (len % 8)
100 		len = roundup(len, 8);
101 
102 	return len;
103 }
104 
105 /*
106  * ieee80211_add_rx_radiotap_header - add radiotap header
107  *
108  * add a radiotap header containing all the fields which the hardware provided.
109  */
110 static void
111 ieee80211_add_rx_radiotap_header(struct ieee80211_local *local,
112 				 struct sk_buff *skb,
113 				 struct ieee80211_rx_status *status,
114 				 struct ieee80211_rate *rate,
115 				 int rtap_len)
116 {
117 	struct ieee80211_radiotap_header *rthdr;
118 	unsigned char *pos;
119 
120 	rthdr = (struct ieee80211_radiotap_header *)skb_push(skb, rtap_len);
121 	memset(rthdr, 0, rtap_len);
122 
123 	/* radiotap header, set always present flags */
124 	rthdr->it_present =
125 		cpu_to_le32((1 << IEEE80211_RADIOTAP_FLAGS) |
126 			    (1 << IEEE80211_RADIOTAP_CHANNEL) |
127 			    (1 << IEEE80211_RADIOTAP_ANTENNA) |
128 			    (1 << IEEE80211_RADIOTAP_RX_FLAGS));
129 	rthdr->it_len = cpu_to_le16(rtap_len);
130 
131 	pos = (unsigned char *)(rthdr+1);
132 
133 	/* the order of the following fields is important */
134 
135 	/* IEEE80211_RADIOTAP_TSFT */
136 	if (status->flag & RX_FLAG_TSFT) {
137 		*(__le64 *)pos = cpu_to_le64(status->mactime);
138 		rthdr->it_present |=
139 			cpu_to_le32(1 << IEEE80211_RADIOTAP_TSFT);
140 		pos += 8;
141 	}
142 
143 	/* IEEE80211_RADIOTAP_FLAGS */
144 	if (local->hw.flags & IEEE80211_HW_RX_INCLUDES_FCS)
145 		*pos |= IEEE80211_RADIOTAP_F_FCS;
146 	if (status->flag & (RX_FLAG_FAILED_FCS_CRC | RX_FLAG_FAILED_PLCP_CRC))
147 		*pos |= IEEE80211_RADIOTAP_F_BADFCS;
148 	if (status->flag & RX_FLAG_SHORTPRE)
149 		*pos |= IEEE80211_RADIOTAP_F_SHORTPRE;
150 	pos++;
151 
152 	/* IEEE80211_RADIOTAP_RATE */
153 	if (status->flag & RX_FLAG_HT) {
154 		/*
155 		 * TODO: add following information into radiotap header once
156 		 * suitable fields are defined for it:
157 		 * - MCS index (status->rate_idx)
158 		 * - HT40 (status->flag & RX_FLAG_40MHZ)
159 		 * - short-GI (status->flag & RX_FLAG_SHORT_GI)
160 		 */
161 		*pos = 0;
162 	} else {
163 		rthdr->it_present |= cpu_to_le32(1 << IEEE80211_RADIOTAP_RATE);
164 		*pos = rate->bitrate / 5;
165 	}
166 	pos++;
167 
168 	/* IEEE80211_RADIOTAP_CHANNEL */
169 	*(__le16 *)pos = cpu_to_le16(status->freq);
170 	pos += 2;
171 	if (status->band == IEEE80211_BAND_5GHZ)
172 		*(__le16 *)pos = cpu_to_le16(IEEE80211_CHAN_OFDM |
173 					     IEEE80211_CHAN_5GHZ);
174 	else if (rate->flags & IEEE80211_RATE_ERP_G)
175 		*(__le16 *)pos = cpu_to_le16(IEEE80211_CHAN_OFDM |
176 					     IEEE80211_CHAN_2GHZ);
177 	else
178 		*(__le16 *)pos = cpu_to_le16(IEEE80211_CHAN_CCK |
179 					     IEEE80211_CHAN_2GHZ);
180 	pos += 2;
181 
182 	/* IEEE80211_RADIOTAP_DBM_ANTSIGNAL */
183 	if (local->hw.flags & IEEE80211_HW_SIGNAL_DBM) {
184 		*pos = status->signal;
185 		rthdr->it_present |=
186 			cpu_to_le32(1 << IEEE80211_RADIOTAP_DBM_ANTSIGNAL);
187 		pos++;
188 	}
189 
190 	/* IEEE80211_RADIOTAP_DBM_ANTNOISE */
191 	if (local->hw.flags & IEEE80211_HW_NOISE_DBM) {
192 		*pos = status->noise;
193 		rthdr->it_present |=
194 			cpu_to_le32(1 << IEEE80211_RADIOTAP_DBM_ANTNOISE);
195 		pos++;
196 	}
197 
198 	/* IEEE80211_RADIOTAP_LOCK_QUALITY is missing */
199 
200 	/* IEEE80211_RADIOTAP_ANTENNA */
201 	*pos = status->antenna;
202 	pos++;
203 
204 	/* IEEE80211_RADIOTAP_DB_ANTNOISE is not used */
205 
206 	/* IEEE80211_RADIOTAP_RX_FLAGS */
207 	/* ensure 2 byte alignment for the 2 byte field as required */
208 	if ((pos - (unsigned char *)rthdr) & 1)
209 		pos++;
210 	if (status->flag & RX_FLAG_FAILED_PLCP_CRC)
211 		*(__le16 *)pos |= cpu_to_le16(IEEE80211_RADIOTAP_F_RX_BADPLCP);
212 	pos += 2;
213 }
214 
215 /*
216  * This function copies a received frame to all monitor interfaces and
217  * returns a cleaned-up SKB that no longer includes the FCS nor the
218  * radiotap header the driver might have added.
219  */
220 static struct sk_buff *
221 ieee80211_rx_monitor(struct ieee80211_local *local, struct sk_buff *origskb,
222 		     struct ieee80211_rx_status *status,
223 		     struct ieee80211_rate *rate)
224 {
225 	struct ieee80211_sub_if_data *sdata;
226 	int needed_headroom = 0;
227 	struct sk_buff *skb, *skb2;
228 	struct net_device *prev_dev = NULL;
229 	int present_fcs_len = 0;
230 	int rtap_len = 0;
231 
232 	/*
233 	 * First, we may need to make a copy of the skb because
234 	 *  (1) we need to modify it for radiotap (if not present), and
235 	 *  (2) the other RX handlers will modify the skb we got.
236 	 *
237 	 * We don't need to, of course, if we aren't going to return
238 	 * the SKB because it has a bad FCS/PLCP checksum.
239 	 */
240 	if (status->flag & RX_FLAG_RADIOTAP)
241 		rtap_len = ieee80211_get_radiotap_len(origskb->data);
242 	else
243 		/* room for the radiotap header based on driver features */
244 		needed_headroom = ieee80211_rx_radiotap_len(local, status);
245 
246 	if (local->hw.flags & IEEE80211_HW_RX_INCLUDES_FCS)
247 		present_fcs_len = FCS_LEN;
248 
249 	if (!local->monitors) {
250 		if (should_drop_frame(status, origskb, present_fcs_len,
251 				      rtap_len)) {
252 			dev_kfree_skb(origskb);
253 			return NULL;
254 		}
255 
256 		return remove_monitor_info(local, origskb, rtap_len);
257 	}
258 
259 	if (should_drop_frame(status, origskb, present_fcs_len, rtap_len)) {
260 		/* only need to expand headroom if necessary */
261 		skb = origskb;
262 		origskb = NULL;
263 
264 		/*
265 		 * This shouldn't trigger often because most devices have an
266 		 * RX header they pull before we get here, and that should
267 		 * be big enough for our radiotap information. We should
268 		 * probably export the length to drivers so that we can have
269 		 * them allocate enough headroom to start with.
270 		 */
271 		if (skb_headroom(skb) < needed_headroom &&
272 		    pskb_expand_head(skb, needed_headroom, 0, GFP_ATOMIC)) {
273 			dev_kfree_skb(skb);
274 			return NULL;
275 		}
276 	} else {
277 		/*
278 		 * Need to make a copy and possibly remove radiotap header
279 		 * and FCS from the original.
280 		 */
281 		skb = skb_copy_expand(origskb, needed_headroom, 0, GFP_ATOMIC);
282 
283 		origskb = remove_monitor_info(local, origskb, rtap_len);
284 
285 		if (!skb)
286 			return origskb;
287 	}
288 
289 	/* if necessary, prepend radiotap information */
290 	if (!(status->flag & RX_FLAG_RADIOTAP))
291 		ieee80211_add_rx_radiotap_header(local, skb, status, rate,
292 						 needed_headroom);
293 
294 	skb_reset_mac_header(skb);
295 	skb->ip_summed = CHECKSUM_UNNECESSARY;
296 	skb->pkt_type = PACKET_OTHERHOST;
297 	skb->protocol = htons(ETH_P_802_2);
298 
299 	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
300 		if (!netif_running(sdata->dev))
301 			continue;
302 
303 		if (sdata->vif.type != NL80211_IFTYPE_MONITOR)
304 			continue;
305 
306 		if (sdata->u.mntr_flags & MONITOR_FLAG_COOK_FRAMES)
307 			continue;
308 
309 		if (prev_dev) {
310 			skb2 = skb_clone(skb, GFP_ATOMIC);
311 			if (skb2) {
312 				skb2->dev = prev_dev;
313 				netif_rx(skb2);
314 			}
315 		}
316 
317 		prev_dev = sdata->dev;
318 		sdata->dev->stats.rx_packets++;
319 		sdata->dev->stats.rx_bytes += skb->len;
320 	}
321 
322 	if (prev_dev) {
323 		skb->dev = prev_dev;
324 		netif_rx(skb);
325 	} else
326 		dev_kfree_skb(skb);
327 
328 	return origskb;
329 }
330 
331 
332 static void ieee80211_parse_qos(struct ieee80211_rx_data *rx)
333 {
334 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
335 	int tid;
336 
337 	/* does the frame have a qos control field? */
338 	if (ieee80211_is_data_qos(hdr->frame_control)) {
339 		u8 *qc = ieee80211_get_qos_ctl(hdr);
340 		/* frame has qos control */
341 		tid = *qc & IEEE80211_QOS_CTL_TID_MASK;
342 		if (*qc & IEEE80211_QOS_CONTROL_A_MSDU_PRESENT)
343 			rx->flags |= IEEE80211_RX_AMSDU;
344 		else
345 			rx->flags &= ~IEEE80211_RX_AMSDU;
346 	} else {
347 		/*
348 		 * IEEE 802.11-2007, 7.1.3.4.1 ("Sequence Number field"):
349 		 *
350 		 *	Sequence numbers for management frames, QoS data
351 		 *	frames with a broadcast/multicast address in the
352 		 *	Address 1 field, and all non-QoS data frames sent
353 		 *	by QoS STAs are assigned using an additional single
354 		 *	modulo-4096 counter, [...]
355 		 *
356 		 * We also use that counter for non-QoS STAs.
357 		 */
358 		tid = NUM_RX_DATA_QUEUES - 1;
359 	}
360 
361 	rx->queue = tid;
362 	/* Set skb->priority to 1d tag if highest order bit of TID is not set.
363 	 * For now, set skb->priority to 0 for other cases. */
364 	rx->skb->priority = (tid > 7) ? 0 : tid;
365 }
366 
367 /**
368  * DOC: Packet alignment
369  *
370  * Drivers always need to pass packets that are aligned to two-byte boundaries
371  * to the stack.
372  *
373  * Additionally, should, if possible, align the payload data in a way that
374  * guarantees that the contained IP header is aligned to a four-byte
375  * boundary. In the case of regular frames, this simply means aligning the
376  * payload to a four-byte boundary (because either the IP header is directly
377  * contained, or IV/RFC1042 headers that have a length divisible by four are
378  * in front of it).
379  *
380  * With A-MSDU frames, however, the payload data address must yield two modulo
381  * four because there are 14-byte 802.3 headers within the A-MSDU frames that
382  * push the IP header further back to a multiple of four again. Thankfully, the
383  * specs were sane enough this time around to require padding each A-MSDU
384  * subframe to a length that is a multiple of four.
385  *
386  * Padding like Atheros hardware adds which is inbetween the 802.11 header and
387  * the payload is not supported, the driver is required to move the 802.11
388  * header to be directly in front of the payload in that case.
389  */
390 static void ieee80211_verify_alignment(struct ieee80211_rx_data *rx)
391 {
392 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
393 	int hdrlen;
394 
395 #ifndef CONFIG_MAC80211_DEBUG_PACKET_ALIGNMENT
396 	return;
397 #endif
398 
399 	if (WARN_ONCE((unsigned long)rx->skb->data & 1,
400 		      "unaligned packet at 0x%p\n", rx->skb->data))
401 		return;
402 
403 	if (!ieee80211_is_data_present(hdr->frame_control))
404 		return;
405 
406 	hdrlen = ieee80211_hdrlen(hdr->frame_control);
407 	if (rx->flags & IEEE80211_RX_AMSDU)
408 		hdrlen += ETH_HLEN;
409 	WARN_ONCE(((unsigned long)(rx->skb->data + hdrlen)) & 3,
410 		  "unaligned IP payload at 0x%p\n", rx->skb->data + hdrlen);
411 }
412 
413 
414 /* rx handlers */
415 
416 static ieee80211_rx_result debug_noinline
417 ieee80211_rx_h_passive_scan(struct ieee80211_rx_data *rx)
418 {
419 	struct ieee80211_local *local = rx->local;
420 	struct sk_buff *skb = rx->skb;
421 
422 	if (unlikely(local->hw_scanning))
423 		return ieee80211_scan_rx(rx->sdata, skb, rx->status);
424 
425 	if (unlikely(local->sw_scanning)) {
426 		/* drop all the other packets during a software scan anyway */
427 		if (ieee80211_scan_rx(rx->sdata, skb, rx->status)
428 		    != RX_QUEUED)
429 			dev_kfree_skb(skb);
430 		return RX_QUEUED;
431 	}
432 
433 	if (unlikely(rx->flags & IEEE80211_RX_IN_SCAN)) {
434 		/* scanning finished during invoking of handlers */
435 		I802_DEBUG_INC(local->rx_handlers_drop_passive_scan);
436 		return RX_DROP_UNUSABLE;
437 	}
438 
439 	return RX_CONTINUE;
440 }
441 
442 
443 static int ieee80211_is_unicast_robust_mgmt_frame(struct sk_buff *skb)
444 {
445 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
446 
447 	if (skb->len < 24 || is_multicast_ether_addr(hdr->addr1))
448 		return 0;
449 
450 	return ieee80211_is_robust_mgmt_frame(hdr);
451 }
452 
453 
454 static int ieee80211_is_multicast_robust_mgmt_frame(struct sk_buff *skb)
455 {
456 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
457 
458 	if (skb->len < 24 || !is_multicast_ether_addr(hdr->addr1))
459 		return 0;
460 
461 	return ieee80211_is_robust_mgmt_frame(hdr);
462 }
463 
464 
465 /* Get the BIP key index from MMIE; return -1 if this is not a BIP frame */
466 static int ieee80211_get_mmie_keyidx(struct sk_buff *skb)
467 {
468 	struct ieee80211_mgmt *hdr = (struct ieee80211_mgmt *) skb->data;
469 	struct ieee80211_mmie *mmie;
470 
471 	if (skb->len < 24 + sizeof(*mmie) ||
472 	    !is_multicast_ether_addr(hdr->da))
473 		return -1;
474 
475 	if (!ieee80211_is_robust_mgmt_frame((struct ieee80211_hdr *) hdr))
476 		return -1; /* not a robust management frame */
477 
478 	mmie = (struct ieee80211_mmie *)
479 		(skb->data + skb->len - sizeof(*mmie));
480 	if (mmie->element_id != WLAN_EID_MMIE ||
481 	    mmie->length != sizeof(*mmie) - 2)
482 		return -1;
483 
484 	return le16_to_cpu(mmie->key_id);
485 }
486 
487 
488 static ieee80211_rx_result
489 ieee80211_rx_mesh_check(struct ieee80211_rx_data *rx)
490 {
491 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
492 	unsigned int hdrlen = ieee80211_hdrlen(hdr->frame_control);
493 
494 	if (ieee80211_is_data(hdr->frame_control)) {
495 		if (!ieee80211_has_a4(hdr->frame_control))
496 			return RX_DROP_MONITOR;
497 		if (memcmp(hdr->addr4, rx->dev->dev_addr, ETH_ALEN) == 0)
498 			return RX_DROP_MONITOR;
499 	}
500 
501 	/* If there is not an established peer link and this is not a peer link
502 	 * establisment frame, beacon or probe, drop the frame.
503 	 */
504 
505 	if (!rx->sta || sta_plink_state(rx->sta) != PLINK_ESTAB) {
506 		struct ieee80211_mgmt *mgmt;
507 
508 		if (!ieee80211_is_mgmt(hdr->frame_control))
509 			return RX_DROP_MONITOR;
510 
511 		if (ieee80211_is_action(hdr->frame_control)) {
512 			mgmt = (struct ieee80211_mgmt *)hdr;
513 			if (mgmt->u.action.category != PLINK_CATEGORY)
514 				return RX_DROP_MONITOR;
515 			return RX_CONTINUE;
516 		}
517 
518 		if (ieee80211_is_probe_req(hdr->frame_control) ||
519 		    ieee80211_is_probe_resp(hdr->frame_control) ||
520 		    ieee80211_is_beacon(hdr->frame_control))
521 			return RX_CONTINUE;
522 
523 		return RX_DROP_MONITOR;
524 
525 	}
526 
527 #define msh_h_get(h, l) ((struct ieee80211s_hdr *) ((u8 *)h + l))
528 
529 	if (ieee80211_is_data(hdr->frame_control) &&
530 	    is_multicast_ether_addr(hdr->addr1) &&
531 	    mesh_rmc_check(hdr->addr4, msh_h_get(hdr, hdrlen), rx->sdata))
532 		return RX_DROP_MONITOR;
533 #undef msh_h_get
534 
535 	return RX_CONTINUE;
536 }
537 
538 
539 static ieee80211_rx_result debug_noinline
540 ieee80211_rx_h_check(struct ieee80211_rx_data *rx)
541 {
542 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
543 
544 	/* Drop duplicate 802.11 retransmissions (IEEE 802.11 Chap. 9.2.9) */
545 	if (rx->sta && !is_multicast_ether_addr(hdr->addr1)) {
546 		if (unlikely(ieee80211_has_retry(hdr->frame_control) &&
547 			     rx->sta->last_seq_ctrl[rx->queue] ==
548 			     hdr->seq_ctrl)) {
549 			if (rx->flags & IEEE80211_RX_RA_MATCH) {
550 				rx->local->dot11FrameDuplicateCount++;
551 				rx->sta->num_duplicates++;
552 			}
553 			return RX_DROP_MONITOR;
554 		} else
555 			rx->sta->last_seq_ctrl[rx->queue] = hdr->seq_ctrl;
556 	}
557 
558 	if (unlikely(rx->skb->len < 16)) {
559 		I802_DEBUG_INC(rx->local->rx_handlers_drop_short);
560 		return RX_DROP_MONITOR;
561 	}
562 
563 	/* Drop disallowed frame classes based on STA auth/assoc state;
564 	 * IEEE 802.11, Chap 5.5.
565 	 *
566 	 * mac80211 filters only based on association state, i.e. it drops
567 	 * Class 3 frames from not associated stations. hostapd sends
568 	 * deauth/disassoc frames when needed. In addition, hostapd is
569 	 * responsible for filtering on both auth and assoc states.
570 	 */
571 
572 	if (ieee80211_vif_is_mesh(&rx->sdata->vif))
573 		return ieee80211_rx_mesh_check(rx);
574 
575 	if (unlikely((ieee80211_is_data(hdr->frame_control) ||
576 		      ieee80211_is_pspoll(hdr->frame_control)) &&
577 		     rx->sdata->vif.type != NL80211_IFTYPE_ADHOC &&
578 		     (!rx->sta || !test_sta_flags(rx->sta, WLAN_STA_ASSOC)))) {
579 		if ((!ieee80211_has_fromds(hdr->frame_control) &&
580 		     !ieee80211_has_tods(hdr->frame_control) &&
581 		     ieee80211_is_data(hdr->frame_control)) ||
582 		    !(rx->flags & IEEE80211_RX_RA_MATCH)) {
583 			/* Drop IBSS frames and frames for other hosts
584 			 * silently. */
585 			return RX_DROP_MONITOR;
586 		}
587 
588 		return RX_DROP_MONITOR;
589 	}
590 
591 	return RX_CONTINUE;
592 }
593 
594 
595 static ieee80211_rx_result debug_noinline
596 ieee80211_rx_h_decrypt(struct ieee80211_rx_data *rx)
597 {
598 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
599 	int keyidx;
600 	int hdrlen;
601 	ieee80211_rx_result result = RX_DROP_UNUSABLE;
602 	struct ieee80211_key *stakey = NULL;
603 	int mmie_keyidx = -1;
604 
605 	/*
606 	 * Key selection 101
607 	 *
608 	 * There are four types of keys:
609 	 *  - GTK (group keys)
610 	 *  - IGTK (group keys for management frames)
611 	 *  - PTK (pairwise keys)
612 	 *  - STK (station-to-station pairwise keys)
613 	 *
614 	 * When selecting a key, we have to distinguish between multicast
615 	 * (including broadcast) and unicast frames, the latter can only
616 	 * use PTKs and STKs while the former always use GTKs and IGTKs.
617 	 * Unless, of course, actual WEP keys ("pre-RSNA") are used, then
618 	 * unicast frames can also use key indices like GTKs. Hence, if we
619 	 * don't have a PTK/STK we check the key index for a WEP key.
620 	 *
621 	 * Note that in a regular BSS, multicast frames are sent by the
622 	 * AP only, associated stations unicast the frame to the AP first
623 	 * which then multicasts it on their behalf.
624 	 *
625 	 * There is also a slight problem in IBSS mode: GTKs are negotiated
626 	 * with each station, that is something we don't currently handle.
627 	 * The spec seems to expect that one negotiates the same key with
628 	 * every station but there's no such requirement; VLANs could be
629 	 * possible.
630 	 */
631 
632 	if (!ieee80211_has_protected(hdr->frame_control)) {
633 		if (!ieee80211_is_mgmt(hdr->frame_control) ||
634 		    rx->sta == NULL || !test_sta_flags(rx->sta, WLAN_STA_MFP))
635 			return RX_CONTINUE;
636 		mmie_keyidx = ieee80211_get_mmie_keyidx(rx->skb);
637 		if (mmie_keyidx < 0)
638 			return RX_CONTINUE;
639 	}
640 
641 	/*
642 	 * No point in finding a key and decrypting if the frame is neither
643 	 * addressed to us nor a multicast frame.
644 	 */
645 	if (!(rx->flags & IEEE80211_RX_RA_MATCH))
646 		return RX_CONTINUE;
647 
648 	if (rx->sta)
649 		stakey = rcu_dereference(rx->sta->key);
650 
651 	if (!is_multicast_ether_addr(hdr->addr1) && stakey) {
652 		rx->key = stakey;
653 	} else if (mmie_keyidx >= 0) {
654 		/* Broadcast/multicast robust management frame / BIP */
655 		if ((rx->status->flag & RX_FLAG_DECRYPTED) &&
656 		    (rx->status->flag & RX_FLAG_IV_STRIPPED))
657 			return RX_CONTINUE;
658 
659 		if (mmie_keyidx < NUM_DEFAULT_KEYS ||
660 		    mmie_keyidx >= NUM_DEFAULT_KEYS + NUM_DEFAULT_MGMT_KEYS)
661 			return RX_DROP_MONITOR; /* unexpected BIP keyidx */
662 		rx->key = rcu_dereference(rx->sdata->keys[mmie_keyidx]);
663 	} else {
664 		/*
665 		 * The device doesn't give us the IV so we won't be
666 		 * able to look up the key. That's ok though, we
667 		 * don't need to decrypt the frame, we just won't
668 		 * be able to keep statistics accurate.
669 		 * Except for key threshold notifications, should
670 		 * we somehow allow the driver to tell us which key
671 		 * the hardware used if this flag is set?
672 		 */
673 		if ((rx->status->flag & RX_FLAG_DECRYPTED) &&
674 		    (rx->status->flag & RX_FLAG_IV_STRIPPED))
675 			return RX_CONTINUE;
676 
677 		hdrlen = ieee80211_hdrlen(hdr->frame_control);
678 
679 		if (rx->skb->len < 8 + hdrlen)
680 			return RX_DROP_UNUSABLE; /* TODO: count this? */
681 
682 		/*
683 		 * no need to call ieee80211_wep_get_keyidx,
684 		 * it verifies a bunch of things we've done already
685 		 */
686 		keyidx = rx->skb->data[hdrlen + 3] >> 6;
687 
688 		rx->key = rcu_dereference(rx->sdata->keys[keyidx]);
689 
690 		/*
691 		 * RSNA-protected unicast frames should always be sent with
692 		 * pairwise or station-to-station keys, but for WEP we allow
693 		 * using a key index as well.
694 		 */
695 		if (rx->key && rx->key->conf.alg != ALG_WEP &&
696 		    !is_multicast_ether_addr(hdr->addr1))
697 			rx->key = NULL;
698 	}
699 
700 	if (rx->key) {
701 		rx->key->tx_rx_count++;
702 		/* TODO: add threshold stuff again */
703 	} else {
704 		return RX_DROP_MONITOR;
705 	}
706 
707 	/* Check for weak IVs if possible */
708 	if (rx->sta && rx->key->conf.alg == ALG_WEP &&
709 	    ieee80211_is_data(hdr->frame_control) &&
710 	    (!(rx->status->flag & RX_FLAG_IV_STRIPPED) ||
711 	     !(rx->status->flag & RX_FLAG_DECRYPTED)) &&
712 	    ieee80211_wep_is_weak_iv(rx->skb, rx->key))
713 		rx->sta->wep_weak_iv_count++;
714 
715 	switch (rx->key->conf.alg) {
716 	case ALG_WEP:
717 		result = ieee80211_crypto_wep_decrypt(rx);
718 		break;
719 	case ALG_TKIP:
720 		result = ieee80211_crypto_tkip_decrypt(rx);
721 		break;
722 	case ALG_CCMP:
723 		result = ieee80211_crypto_ccmp_decrypt(rx);
724 		break;
725 	case ALG_AES_CMAC:
726 		result = ieee80211_crypto_aes_cmac_decrypt(rx);
727 		break;
728 	}
729 
730 	/* either the frame has been decrypted or will be dropped */
731 	rx->status->flag |= RX_FLAG_DECRYPTED;
732 
733 	return result;
734 }
735 
736 static ieee80211_rx_result debug_noinline
737 ieee80211_rx_h_check_more_data(struct ieee80211_rx_data *rx)
738 {
739 	struct ieee80211_local *local;
740 	struct ieee80211_hdr *hdr;
741 	struct sk_buff *skb;
742 
743 	local = rx->local;
744 	skb = rx->skb;
745 	hdr = (struct ieee80211_hdr *) skb->data;
746 
747 	if (!local->pspolling)
748 		return RX_CONTINUE;
749 
750 	if (!ieee80211_has_fromds(hdr->frame_control))
751 		/* this is not from AP */
752 		return RX_CONTINUE;
753 
754 	if (!ieee80211_is_data(hdr->frame_control))
755 		return RX_CONTINUE;
756 
757 	if (!ieee80211_has_moredata(hdr->frame_control)) {
758 		/* AP has no more frames buffered for us */
759 		local->pspolling = false;
760 		return RX_CONTINUE;
761 	}
762 
763 	/* more data bit is set, let's request a new frame from the AP */
764 	ieee80211_send_pspoll(local, rx->sdata);
765 
766 	return RX_CONTINUE;
767 }
768 
769 static void ap_sta_ps_start(struct sta_info *sta)
770 {
771 	struct ieee80211_sub_if_data *sdata = sta->sdata;
772 	struct ieee80211_local *local = sdata->local;
773 
774 	atomic_inc(&sdata->bss->num_sta_ps);
775 	set_and_clear_sta_flags(sta, WLAN_STA_PS, WLAN_STA_PSPOLL);
776 	if (local->ops->sta_notify)
777 		local->ops->sta_notify(local_to_hw(local), &sdata->vif,
778 					STA_NOTIFY_SLEEP, &sta->sta);
779 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
780 	printk(KERN_DEBUG "%s: STA %pM aid %d enters power save mode\n",
781 	       sdata->dev->name, sta->sta.addr, sta->sta.aid);
782 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
783 }
784 
785 static int ap_sta_ps_end(struct sta_info *sta)
786 {
787 	struct ieee80211_sub_if_data *sdata = sta->sdata;
788 	struct ieee80211_local *local = sdata->local;
789 	struct sk_buff *skb;
790 	int sent = 0;
791 
792 	atomic_dec(&sdata->bss->num_sta_ps);
793 
794 	clear_sta_flags(sta, WLAN_STA_PS | WLAN_STA_PSPOLL);
795 	if (local->ops->sta_notify)
796 		local->ops->sta_notify(local_to_hw(local), &sdata->vif,
797 					STA_NOTIFY_AWAKE, &sta->sta);
798 
799 	if (!skb_queue_empty(&sta->ps_tx_buf))
800 		sta_info_clear_tim_bit(sta);
801 
802 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
803 	printk(KERN_DEBUG "%s: STA %pM aid %d exits power save mode\n",
804 	       sdata->dev->name, sta->sta.addr, sta->sta.aid);
805 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
806 
807 	/* Send all buffered frames to the station */
808 	while ((skb = skb_dequeue(&sta->tx_filtered)) != NULL) {
809 		sent++;
810 		skb->requeue = 1;
811 		dev_queue_xmit(skb);
812 	}
813 	while ((skb = skb_dequeue(&sta->ps_tx_buf)) != NULL) {
814 		local->total_ps_buffered--;
815 		sent++;
816 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
817 		printk(KERN_DEBUG "%s: STA %pM aid %d send PS frame "
818 		       "since STA not sleeping anymore\n", sdata->dev->name,
819 		       sta->sta.addr, sta->sta.aid);
820 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
821 		skb->requeue = 1;
822 		dev_queue_xmit(skb);
823 	}
824 
825 	return sent;
826 }
827 
828 static ieee80211_rx_result debug_noinline
829 ieee80211_rx_h_sta_process(struct ieee80211_rx_data *rx)
830 {
831 	struct sta_info *sta = rx->sta;
832 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
833 
834 	if (!sta)
835 		return RX_CONTINUE;
836 
837 	/* Update last_rx only for IBSS packets which are for the current
838 	 * BSSID to avoid keeping the current IBSS network alive in cases where
839 	 * other STAs are using different BSSID. */
840 	if (rx->sdata->vif.type == NL80211_IFTYPE_ADHOC) {
841 		u8 *bssid = ieee80211_get_bssid(hdr, rx->skb->len,
842 						NL80211_IFTYPE_ADHOC);
843 		if (compare_ether_addr(bssid, rx->sdata->u.ibss.bssid) == 0)
844 			sta->last_rx = jiffies;
845 	} else
846 	if (!is_multicast_ether_addr(hdr->addr1) ||
847 	    rx->sdata->vif.type == NL80211_IFTYPE_STATION) {
848 		/* Update last_rx only for unicast frames in order to prevent
849 		 * the Probe Request frames (the only broadcast frames from a
850 		 * STA in infrastructure mode) from keeping a connection alive.
851 		 * Mesh beacons will update last_rx when if they are found to
852 		 * match the current local configuration when processed.
853 		 */
854 		if (rx->sdata->vif.type == NL80211_IFTYPE_STATION &&
855 		    ieee80211_is_beacon(hdr->frame_control)) {
856 			rx->sdata->u.mgd.last_beacon = jiffies;
857 		} else
858 			sta->last_rx = jiffies;
859 	}
860 
861 	if (!(rx->flags & IEEE80211_RX_RA_MATCH))
862 		return RX_CONTINUE;
863 
864 	if (rx->sdata->vif.type == NL80211_IFTYPE_STATION)
865 		ieee80211_sta_rx_notify(rx->sdata, hdr);
866 
867 	sta->rx_fragments++;
868 	sta->rx_bytes += rx->skb->len;
869 	sta->last_signal = rx->status->signal;
870 	sta->last_qual = rx->status->qual;
871 	sta->last_noise = rx->status->noise;
872 
873 	/*
874 	 * Change STA power saving mode only at the end of a frame
875 	 * exchange sequence.
876 	 */
877 	if (!ieee80211_has_morefrags(hdr->frame_control) &&
878 	    (rx->sdata->vif.type == NL80211_IFTYPE_AP ||
879 	     rx->sdata->vif.type == NL80211_IFTYPE_AP_VLAN)) {
880 		if (test_sta_flags(sta, WLAN_STA_PS)) {
881 			/*
882 			 * Ignore doze->wake transitions that are
883 			 * indicated by non-data frames, the standard
884 			 * is unclear here, but for example going to
885 			 * PS mode and then scanning would cause a
886 			 * doze->wake transition for the probe request,
887 			 * and that is clearly undesirable.
888 			 */
889 			if (ieee80211_is_data(hdr->frame_control) &&
890 			    !ieee80211_has_pm(hdr->frame_control))
891 				rx->sent_ps_buffered += ap_sta_ps_end(sta);
892 		} else {
893 			if (ieee80211_has_pm(hdr->frame_control))
894 				ap_sta_ps_start(sta);
895 		}
896 	}
897 
898 	/* Drop data::nullfunc frames silently, since they are used only to
899 	 * control station power saving mode. */
900 	if (ieee80211_is_nullfunc(hdr->frame_control)) {
901 		I802_DEBUG_INC(rx->local->rx_handlers_drop_nullfunc);
902 		/* Update counter and free packet here to avoid counting this
903 		 * as a dropped packed. */
904 		sta->rx_packets++;
905 		dev_kfree_skb(rx->skb);
906 		return RX_QUEUED;
907 	}
908 
909 	return RX_CONTINUE;
910 } /* ieee80211_rx_h_sta_process */
911 
912 static inline struct ieee80211_fragment_entry *
913 ieee80211_reassemble_add(struct ieee80211_sub_if_data *sdata,
914 			 unsigned int frag, unsigned int seq, int rx_queue,
915 			 struct sk_buff **skb)
916 {
917 	struct ieee80211_fragment_entry *entry;
918 	int idx;
919 
920 	idx = sdata->fragment_next;
921 	entry = &sdata->fragments[sdata->fragment_next++];
922 	if (sdata->fragment_next >= IEEE80211_FRAGMENT_MAX)
923 		sdata->fragment_next = 0;
924 
925 	if (!skb_queue_empty(&entry->skb_list)) {
926 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG
927 		struct ieee80211_hdr *hdr =
928 			(struct ieee80211_hdr *) entry->skb_list.next->data;
929 		printk(KERN_DEBUG "%s: RX reassembly removed oldest "
930 		       "fragment entry (idx=%d age=%lu seq=%d last_frag=%d "
931 		       "addr1=%pM addr2=%pM\n",
932 		       sdata->dev->name, idx,
933 		       jiffies - entry->first_frag_time, entry->seq,
934 		       entry->last_frag, hdr->addr1, hdr->addr2);
935 #endif
936 		__skb_queue_purge(&entry->skb_list);
937 	}
938 
939 	__skb_queue_tail(&entry->skb_list, *skb); /* no need for locking */
940 	*skb = NULL;
941 	entry->first_frag_time = jiffies;
942 	entry->seq = seq;
943 	entry->rx_queue = rx_queue;
944 	entry->last_frag = frag;
945 	entry->ccmp = 0;
946 	entry->extra_len = 0;
947 
948 	return entry;
949 }
950 
951 static inline struct ieee80211_fragment_entry *
952 ieee80211_reassemble_find(struct ieee80211_sub_if_data *sdata,
953 			  unsigned int frag, unsigned int seq,
954 			  int rx_queue, struct ieee80211_hdr *hdr)
955 {
956 	struct ieee80211_fragment_entry *entry;
957 	int i, idx;
958 
959 	idx = sdata->fragment_next;
960 	for (i = 0; i < IEEE80211_FRAGMENT_MAX; i++) {
961 		struct ieee80211_hdr *f_hdr;
962 
963 		idx--;
964 		if (idx < 0)
965 			idx = IEEE80211_FRAGMENT_MAX - 1;
966 
967 		entry = &sdata->fragments[idx];
968 		if (skb_queue_empty(&entry->skb_list) || entry->seq != seq ||
969 		    entry->rx_queue != rx_queue ||
970 		    entry->last_frag + 1 != frag)
971 			continue;
972 
973 		f_hdr = (struct ieee80211_hdr *)entry->skb_list.next->data;
974 
975 		/*
976 		 * Check ftype and addresses are equal, else check next fragment
977 		 */
978 		if (((hdr->frame_control ^ f_hdr->frame_control) &
979 		     cpu_to_le16(IEEE80211_FCTL_FTYPE)) ||
980 		    compare_ether_addr(hdr->addr1, f_hdr->addr1) != 0 ||
981 		    compare_ether_addr(hdr->addr2, f_hdr->addr2) != 0)
982 			continue;
983 
984 		if (time_after(jiffies, entry->first_frag_time + 2 * HZ)) {
985 			__skb_queue_purge(&entry->skb_list);
986 			continue;
987 		}
988 		return entry;
989 	}
990 
991 	return NULL;
992 }
993 
994 static ieee80211_rx_result debug_noinline
995 ieee80211_rx_h_defragment(struct ieee80211_rx_data *rx)
996 {
997 	struct ieee80211_hdr *hdr;
998 	u16 sc;
999 	__le16 fc;
1000 	unsigned int frag, seq;
1001 	struct ieee80211_fragment_entry *entry;
1002 	struct sk_buff *skb;
1003 
1004 	hdr = (struct ieee80211_hdr *)rx->skb->data;
1005 	fc = hdr->frame_control;
1006 	sc = le16_to_cpu(hdr->seq_ctrl);
1007 	frag = sc & IEEE80211_SCTL_FRAG;
1008 
1009 	if (likely((!ieee80211_has_morefrags(fc) && frag == 0) ||
1010 		   (rx->skb)->len < 24 ||
1011 		   is_multicast_ether_addr(hdr->addr1))) {
1012 		/* not fragmented */
1013 		goto out;
1014 	}
1015 	I802_DEBUG_INC(rx->local->rx_handlers_fragments);
1016 
1017 	seq = (sc & IEEE80211_SCTL_SEQ) >> 4;
1018 
1019 	if (frag == 0) {
1020 		/* This is the first fragment of a new frame. */
1021 		entry = ieee80211_reassemble_add(rx->sdata, frag, seq,
1022 						 rx->queue, &(rx->skb));
1023 		if (rx->key && rx->key->conf.alg == ALG_CCMP &&
1024 		    ieee80211_has_protected(fc)) {
1025 			/* Store CCMP PN so that we can verify that the next
1026 			 * fragment has a sequential PN value. */
1027 			entry->ccmp = 1;
1028 			memcpy(entry->last_pn,
1029 			       rx->key->u.ccmp.rx_pn[rx->queue],
1030 			       CCMP_PN_LEN);
1031 		}
1032 		return RX_QUEUED;
1033 	}
1034 
1035 	/* This is a fragment for a frame that should already be pending in
1036 	 * fragment cache. Add this fragment to the end of the pending entry.
1037 	 */
1038 	entry = ieee80211_reassemble_find(rx->sdata, frag, seq, rx->queue, hdr);
1039 	if (!entry) {
1040 		I802_DEBUG_INC(rx->local->rx_handlers_drop_defrag);
1041 		return RX_DROP_MONITOR;
1042 	}
1043 
1044 	/* Verify that MPDUs within one MSDU have sequential PN values.
1045 	 * (IEEE 802.11i, 8.3.3.4.5) */
1046 	if (entry->ccmp) {
1047 		int i;
1048 		u8 pn[CCMP_PN_LEN], *rpn;
1049 		if (!rx->key || rx->key->conf.alg != ALG_CCMP)
1050 			return RX_DROP_UNUSABLE;
1051 		memcpy(pn, entry->last_pn, CCMP_PN_LEN);
1052 		for (i = CCMP_PN_LEN - 1; i >= 0; i--) {
1053 			pn[i]++;
1054 			if (pn[i])
1055 				break;
1056 		}
1057 		rpn = rx->key->u.ccmp.rx_pn[rx->queue];
1058 		if (memcmp(pn, rpn, CCMP_PN_LEN))
1059 			return RX_DROP_UNUSABLE;
1060 		memcpy(entry->last_pn, pn, CCMP_PN_LEN);
1061 	}
1062 
1063 	skb_pull(rx->skb, ieee80211_hdrlen(fc));
1064 	__skb_queue_tail(&entry->skb_list, rx->skb);
1065 	entry->last_frag = frag;
1066 	entry->extra_len += rx->skb->len;
1067 	if (ieee80211_has_morefrags(fc)) {
1068 		rx->skb = NULL;
1069 		return RX_QUEUED;
1070 	}
1071 
1072 	rx->skb = __skb_dequeue(&entry->skb_list);
1073 	if (skb_tailroom(rx->skb) < entry->extra_len) {
1074 		I802_DEBUG_INC(rx->local->rx_expand_skb_head2);
1075 		if (unlikely(pskb_expand_head(rx->skb, 0, entry->extra_len,
1076 					      GFP_ATOMIC))) {
1077 			I802_DEBUG_INC(rx->local->rx_handlers_drop_defrag);
1078 			__skb_queue_purge(&entry->skb_list);
1079 			return RX_DROP_UNUSABLE;
1080 		}
1081 	}
1082 	while ((skb = __skb_dequeue(&entry->skb_list))) {
1083 		memcpy(skb_put(rx->skb, skb->len), skb->data, skb->len);
1084 		dev_kfree_skb(skb);
1085 	}
1086 
1087 	/* Complete frame has been reassembled - process it now */
1088 	rx->flags |= IEEE80211_RX_FRAGMENTED;
1089 
1090  out:
1091 	if (rx->sta)
1092 		rx->sta->rx_packets++;
1093 	if (is_multicast_ether_addr(hdr->addr1))
1094 		rx->local->dot11MulticastReceivedFrameCount++;
1095 	else
1096 		ieee80211_led_rx(rx->local);
1097 	return RX_CONTINUE;
1098 }
1099 
1100 static ieee80211_rx_result debug_noinline
1101 ieee80211_rx_h_ps_poll(struct ieee80211_rx_data *rx)
1102 {
1103 	struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(rx->dev);
1104 	struct sk_buff *skb;
1105 	int no_pending_pkts;
1106 	__le16 fc = ((struct ieee80211_hdr *)rx->skb->data)->frame_control;
1107 
1108 	if (likely(!rx->sta || !ieee80211_is_pspoll(fc) ||
1109 		   !(rx->flags & IEEE80211_RX_RA_MATCH)))
1110 		return RX_CONTINUE;
1111 
1112 	if ((sdata->vif.type != NL80211_IFTYPE_AP) &&
1113 	    (sdata->vif.type != NL80211_IFTYPE_AP_VLAN))
1114 		return RX_DROP_UNUSABLE;
1115 
1116 	skb = skb_dequeue(&rx->sta->tx_filtered);
1117 	if (!skb) {
1118 		skb = skb_dequeue(&rx->sta->ps_tx_buf);
1119 		if (skb)
1120 			rx->local->total_ps_buffered--;
1121 	}
1122 	no_pending_pkts = skb_queue_empty(&rx->sta->tx_filtered) &&
1123 		skb_queue_empty(&rx->sta->ps_tx_buf);
1124 
1125 	if (skb) {
1126 		struct ieee80211_hdr *hdr =
1127 			(struct ieee80211_hdr *) skb->data;
1128 
1129 		/*
1130 		 * Tell TX path to send one frame even though the STA may
1131 		 * still remain is PS mode after this frame exchange.
1132 		 */
1133 		set_sta_flags(rx->sta, WLAN_STA_PSPOLL);
1134 
1135 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
1136 		printk(KERN_DEBUG "STA %pM aid %d: PS Poll (entries after %d)\n",
1137 		       rx->sta->sta.addr, rx->sta->sta.aid,
1138 		       skb_queue_len(&rx->sta->ps_tx_buf));
1139 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
1140 
1141 		/* Use MoreData flag to indicate whether there are more
1142 		 * buffered frames for this STA */
1143 		if (no_pending_pkts)
1144 			hdr->frame_control &= cpu_to_le16(~IEEE80211_FCTL_MOREDATA);
1145 		else
1146 			hdr->frame_control |= cpu_to_le16(IEEE80211_FCTL_MOREDATA);
1147 
1148 		dev_queue_xmit(skb);
1149 
1150 		if (no_pending_pkts)
1151 			sta_info_clear_tim_bit(rx->sta);
1152 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
1153 	} else if (!rx->sent_ps_buffered) {
1154 		/*
1155 		 * FIXME: This can be the result of a race condition between
1156 		 *	  us expiring a frame and the station polling for it.
1157 		 *	  Should we send it a null-func frame indicating we
1158 		 *	  have nothing buffered for it?
1159 		 */
1160 		printk(KERN_DEBUG "%s: STA %pM sent PS Poll even "
1161 		       "though there are no buffered frames for it\n",
1162 		       rx->dev->name, rx->sta->sta.addr);
1163 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
1164 	}
1165 
1166 	/* Free PS Poll skb here instead of returning RX_DROP that would
1167 	 * count as an dropped frame. */
1168 	dev_kfree_skb(rx->skb);
1169 
1170 	return RX_QUEUED;
1171 }
1172 
1173 static ieee80211_rx_result debug_noinline
1174 ieee80211_rx_h_remove_qos_control(struct ieee80211_rx_data *rx)
1175 {
1176 	u8 *data = rx->skb->data;
1177 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)data;
1178 
1179 	if (!ieee80211_is_data_qos(hdr->frame_control))
1180 		return RX_CONTINUE;
1181 
1182 	/* remove the qos control field, update frame type and meta-data */
1183 	memmove(data + IEEE80211_QOS_CTL_LEN, data,
1184 		ieee80211_hdrlen(hdr->frame_control) - IEEE80211_QOS_CTL_LEN);
1185 	hdr = (struct ieee80211_hdr *)skb_pull(rx->skb, IEEE80211_QOS_CTL_LEN);
1186 	/* change frame type to non QOS */
1187 	hdr->frame_control &= ~cpu_to_le16(IEEE80211_STYPE_QOS_DATA);
1188 
1189 	return RX_CONTINUE;
1190 }
1191 
1192 static int
1193 ieee80211_802_1x_port_control(struct ieee80211_rx_data *rx)
1194 {
1195 	if (unlikely(!rx->sta ||
1196 	    !test_sta_flags(rx->sta, WLAN_STA_AUTHORIZED)))
1197 		return -EACCES;
1198 
1199 	return 0;
1200 }
1201 
1202 static int
1203 ieee80211_drop_unencrypted(struct ieee80211_rx_data *rx, __le16 fc)
1204 {
1205 	/*
1206 	 * Pass through unencrypted frames if the hardware has
1207 	 * decrypted them already.
1208 	 */
1209 	if (rx->status->flag & RX_FLAG_DECRYPTED)
1210 		return 0;
1211 
1212 	/* Drop unencrypted frames if key is set. */
1213 	if (unlikely(!ieee80211_has_protected(fc) &&
1214 		     !ieee80211_is_nullfunc(fc) &&
1215 		     (!ieee80211_is_mgmt(fc) ||
1216 		      (ieee80211_is_unicast_robust_mgmt_frame(rx->skb) &&
1217 		       rx->sta && test_sta_flags(rx->sta, WLAN_STA_MFP))) &&
1218 		     (rx->key || rx->sdata->drop_unencrypted)))
1219 		return -EACCES;
1220 	/* BIP does not use Protected field, so need to check MMIE */
1221 	if (unlikely(rx->sta && test_sta_flags(rx->sta, WLAN_STA_MFP) &&
1222 		     ieee80211_is_multicast_robust_mgmt_frame(rx->skb) &&
1223 		     ieee80211_get_mmie_keyidx(rx->skb) < 0 &&
1224 		     (rx->key || rx->sdata->drop_unencrypted)))
1225 		return -EACCES;
1226 
1227 	return 0;
1228 }
1229 
1230 static int
1231 ieee80211_data_to_8023(struct ieee80211_rx_data *rx)
1232 {
1233 	struct net_device *dev = rx->dev;
1234 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) rx->skb->data;
1235 	u16 hdrlen, ethertype;
1236 	u8 *payload;
1237 	u8 dst[ETH_ALEN];
1238 	u8 src[ETH_ALEN] __aligned(2);
1239 	struct sk_buff *skb = rx->skb;
1240 	struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
1241 
1242 	if (unlikely(!ieee80211_is_data_present(hdr->frame_control)))
1243 		return -1;
1244 
1245 	hdrlen = ieee80211_hdrlen(hdr->frame_control);
1246 
1247 	/* convert IEEE 802.11 header + possible LLC headers into Ethernet
1248 	 * header
1249 	 * IEEE 802.11 address fields:
1250 	 * ToDS FromDS Addr1 Addr2 Addr3 Addr4
1251 	 *   0     0   DA    SA    BSSID n/a
1252 	 *   0     1   DA    BSSID SA    n/a
1253 	 *   1     0   BSSID SA    DA    n/a
1254 	 *   1     1   RA    TA    DA    SA
1255 	 */
1256 	memcpy(dst, ieee80211_get_DA(hdr), ETH_ALEN);
1257 	memcpy(src, ieee80211_get_SA(hdr), ETH_ALEN);
1258 
1259 	switch (hdr->frame_control &
1260 		cpu_to_le16(IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS)) {
1261 	case cpu_to_le16(IEEE80211_FCTL_TODS):
1262 		if (unlikely(sdata->vif.type != NL80211_IFTYPE_AP &&
1263 			     sdata->vif.type != NL80211_IFTYPE_AP_VLAN))
1264 			return -1;
1265 		break;
1266 	case cpu_to_le16(IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS):
1267 		if (unlikely(sdata->vif.type != NL80211_IFTYPE_WDS &&
1268 			     sdata->vif.type != NL80211_IFTYPE_MESH_POINT))
1269 			return -1;
1270 		if (ieee80211_vif_is_mesh(&sdata->vif)) {
1271 			struct ieee80211s_hdr *meshdr = (struct ieee80211s_hdr *)
1272 				(skb->data + hdrlen);
1273 			hdrlen += ieee80211_get_mesh_hdrlen(meshdr);
1274 			if (meshdr->flags & MESH_FLAGS_AE_A5_A6) {
1275 				memcpy(dst, meshdr->eaddr1, ETH_ALEN);
1276 				memcpy(src, meshdr->eaddr2, ETH_ALEN);
1277 			}
1278 		}
1279 		break;
1280 	case cpu_to_le16(IEEE80211_FCTL_FROMDS):
1281 		if (sdata->vif.type != NL80211_IFTYPE_STATION ||
1282 		    (is_multicast_ether_addr(dst) &&
1283 		     !compare_ether_addr(src, dev->dev_addr)))
1284 			return -1;
1285 		break;
1286 	case cpu_to_le16(0):
1287 		if (sdata->vif.type != NL80211_IFTYPE_ADHOC)
1288 			return -1;
1289 		break;
1290 	}
1291 
1292 	if (unlikely(skb->len - hdrlen < 8))
1293 		return -1;
1294 
1295 	payload = skb->data + hdrlen;
1296 	ethertype = (payload[6] << 8) | payload[7];
1297 
1298 	if (likely((compare_ether_addr(payload, rfc1042_header) == 0 &&
1299 		    ethertype != ETH_P_AARP && ethertype != ETH_P_IPX) ||
1300 		   compare_ether_addr(payload, bridge_tunnel_header) == 0)) {
1301 		/* remove RFC1042 or Bridge-Tunnel encapsulation and
1302 		 * replace EtherType */
1303 		skb_pull(skb, hdrlen + 6);
1304 		memcpy(skb_push(skb, ETH_ALEN), src, ETH_ALEN);
1305 		memcpy(skb_push(skb, ETH_ALEN), dst, ETH_ALEN);
1306 	} else {
1307 		struct ethhdr *ehdr;
1308 		__be16 len;
1309 
1310 		skb_pull(skb, hdrlen);
1311 		len = htons(skb->len);
1312 		ehdr = (struct ethhdr *) skb_push(skb, sizeof(struct ethhdr));
1313 		memcpy(ehdr->h_dest, dst, ETH_ALEN);
1314 		memcpy(ehdr->h_source, src, ETH_ALEN);
1315 		ehdr->h_proto = len;
1316 	}
1317 	return 0;
1318 }
1319 
1320 /*
1321  * requires that rx->skb is a frame with ethernet header
1322  */
1323 static bool ieee80211_frame_allowed(struct ieee80211_rx_data *rx, __le16 fc)
1324 {
1325 	static const u8 pae_group_addr[ETH_ALEN] __aligned(2)
1326 		= { 0x01, 0x80, 0xC2, 0x00, 0x00, 0x03 };
1327 	struct ethhdr *ehdr = (struct ethhdr *) rx->skb->data;
1328 
1329 	/*
1330 	 * Allow EAPOL frames to us/the PAE group address regardless
1331 	 * of whether the frame was encrypted or not.
1332 	 */
1333 	if (ehdr->h_proto == htons(ETH_P_PAE) &&
1334 	    (compare_ether_addr(ehdr->h_dest, rx->dev->dev_addr) == 0 ||
1335 	     compare_ether_addr(ehdr->h_dest, pae_group_addr) == 0))
1336 		return true;
1337 
1338 	if (ieee80211_802_1x_port_control(rx) ||
1339 	    ieee80211_drop_unencrypted(rx, fc))
1340 		return false;
1341 
1342 	return true;
1343 }
1344 
1345 /*
1346  * requires that rx->skb is a frame with ethernet header
1347  */
1348 static void
1349 ieee80211_deliver_skb(struct ieee80211_rx_data *rx)
1350 {
1351 	struct net_device *dev = rx->dev;
1352 	struct ieee80211_local *local = rx->local;
1353 	struct sk_buff *skb, *xmit_skb;
1354 	struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
1355 	struct ethhdr *ehdr = (struct ethhdr *) rx->skb->data;
1356 	struct sta_info *dsta;
1357 
1358 	skb = rx->skb;
1359 	xmit_skb = NULL;
1360 
1361 	if ((sdata->vif.type == NL80211_IFTYPE_AP ||
1362 	     sdata->vif.type == NL80211_IFTYPE_AP_VLAN) &&
1363 	    !(sdata->flags & IEEE80211_SDATA_DONT_BRIDGE_PACKETS) &&
1364 	    (rx->flags & IEEE80211_RX_RA_MATCH)) {
1365 		if (is_multicast_ether_addr(ehdr->h_dest)) {
1366 			/*
1367 			 * send multicast frames both to higher layers in
1368 			 * local net stack and back to the wireless medium
1369 			 */
1370 			xmit_skb = skb_copy(skb, GFP_ATOMIC);
1371 			if (!xmit_skb && net_ratelimit())
1372 				printk(KERN_DEBUG "%s: failed to clone "
1373 				       "multicast frame\n", dev->name);
1374 		} else {
1375 			dsta = sta_info_get(local, skb->data);
1376 			if (dsta && dsta->sdata->dev == dev) {
1377 				/*
1378 				 * The destination station is associated to
1379 				 * this AP (in this VLAN), so send the frame
1380 				 * directly to it and do not pass it to local
1381 				 * net stack.
1382 				 */
1383 				xmit_skb = skb;
1384 				skb = NULL;
1385 			}
1386 		}
1387 	}
1388 
1389 	if (skb) {
1390 		int align __maybe_unused;
1391 
1392 #if defined(CONFIG_MAC80211_DEBUG_PACKET_ALIGNMENT) || !defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS)
1393 		/*
1394 		 * 'align' will only take the values 0 or 2 here
1395 		 * since all frames are required to be aligned
1396 		 * to 2-byte boundaries when being passed to
1397 		 * mac80211. That also explains the __skb_push()
1398 		 * below.
1399 		 */
1400 		align = (unsigned long)skb->data & 3;
1401 		if (align) {
1402 			if (WARN_ON(skb_headroom(skb) < 3)) {
1403 				dev_kfree_skb(skb);
1404 				skb = NULL;
1405 			} else {
1406 				u8 *data = skb->data;
1407 				size_t len = skb->len;
1408 				u8 *new = __skb_push(skb, align);
1409 				memmove(new, data, len);
1410 				__skb_trim(skb, len);
1411 			}
1412 		}
1413 #endif
1414 
1415 		if (skb) {
1416 			/* deliver to local stack */
1417 			skb->protocol = eth_type_trans(skb, dev);
1418 			memset(skb->cb, 0, sizeof(skb->cb));
1419 			netif_rx(skb);
1420 		}
1421 	}
1422 
1423 	if (xmit_skb) {
1424 		/* send to wireless media */
1425 		xmit_skb->protocol = htons(ETH_P_802_3);
1426 		skb_reset_network_header(xmit_skb);
1427 		skb_reset_mac_header(xmit_skb);
1428 		dev_queue_xmit(xmit_skb);
1429 	}
1430 }
1431 
1432 static ieee80211_rx_result debug_noinline
1433 ieee80211_rx_h_amsdu(struct ieee80211_rx_data *rx)
1434 {
1435 	struct net_device *dev = rx->dev;
1436 	struct ieee80211_local *local = rx->local;
1437 	u16 ethertype;
1438 	u8 *payload;
1439 	struct sk_buff *skb = rx->skb, *frame = NULL;
1440 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
1441 	__le16 fc = hdr->frame_control;
1442 	const struct ethhdr *eth;
1443 	int remaining, err;
1444 	u8 dst[ETH_ALEN];
1445 	u8 src[ETH_ALEN];
1446 
1447 	if (unlikely(!ieee80211_is_data(fc)))
1448 		return RX_CONTINUE;
1449 
1450 	if (unlikely(!ieee80211_is_data_present(fc)))
1451 		return RX_DROP_MONITOR;
1452 
1453 	if (!(rx->flags & IEEE80211_RX_AMSDU))
1454 		return RX_CONTINUE;
1455 
1456 	err = ieee80211_data_to_8023(rx);
1457 	if (unlikely(err))
1458 		return RX_DROP_UNUSABLE;
1459 
1460 	skb->dev = dev;
1461 
1462 	dev->stats.rx_packets++;
1463 	dev->stats.rx_bytes += skb->len;
1464 
1465 	/* skip the wrapping header */
1466 	eth = (struct ethhdr *) skb_pull(skb, sizeof(struct ethhdr));
1467 	if (!eth)
1468 		return RX_DROP_UNUSABLE;
1469 
1470 	while (skb != frame) {
1471 		u8 padding;
1472 		__be16 len = eth->h_proto;
1473 		unsigned int subframe_len = sizeof(struct ethhdr) + ntohs(len);
1474 
1475 		remaining = skb->len;
1476 		memcpy(dst, eth->h_dest, ETH_ALEN);
1477 		memcpy(src, eth->h_source, ETH_ALEN);
1478 
1479 		padding = ((4 - subframe_len) & 0x3);
1480 		/* the last MSDU has no padding */
1481 		if (subframe_len > remaining)
1482 			return RX_DROP_UNUSABLE;
1483 
1484 		skb_pull(skb, sizeof(struct ethhdr));
1485 		/* if last subframe reuse skb */
1486 		if (remaining <= subframe_len + padding)
1487 			frame = skb;
1488 		else {
1489 			/*
1490 			 * Allocate and reserve two bytes more for payload
1491 			 * alignment since sizeof(struct ethhdr) is 14.
1492 			 */
1493 			frame = dev_alloc_skb(
1494 				ALIGN(local->hw.extra_tx_headroom, 4) +
1495 				subframe_len + 2);
1496 
1497 			if (frame == NULL)
1498 				return RX_DROP_UNUSABLE;
1499 
1500 			skb_reserve(frame,
1501 				    ALIGN(local->hw.extra_tx_headroom, 4) +
1502 				    sizeof(struct ethhdr) + 2);
1503 			memcpy(skb_put(frame, ntohs(len)), skb->data,
1504 				ntohs(len));
1505 
1506 			eth = (struct ethhdr *) skb_pull(skb, ntohs(len) +
1507 							padding);
1508 			if (!eth) {
1509 				dev_kfree_skb(frame);
1510 				return RX_DROP_UNUSABLE;
1511 			}
1512 		}
1513 
1514 		skb_reset_network_header(frame);
1515 		frame->dev = dev;
1516 		frame->priority = skb->priority;
1517 		rx->skb = frame;
1518 
1519 		payload = frame->data;
1520 		ethertype = (payload[6] << 8) | payload[7];
1521 
1522 		if (likely((compare_ether_addr(payload, rfc1042_header) == 0 &&
1523 			    ethertype != ETH_P_AARP && ethertype != ETH_P_IPX) ||
1524 			   compare_ether_addr(payload,
1525 					      bridge_tunnel_header) == 0)) {
1526 			/* remove RFC1042 or Bridge-Tunnel
1527 			 * encapsulation and replace EtherType */
1528 			skb_pull(frame, 6);
1529 			memcpy(skb_push(frame, ETH_ALEN), src, ETH_ALEN);
1530 			memcpy(skb_push(frame, ETH_ALEN), dst, ETH_ALEN);
1531 		} else {
1532 			memcpy(skb_push(frame, sizeof(__be16)),
1533 			       &len, sizeof(__be16));
1534 			memcpy(skb_push(frame, ETH_ALEN), src, ETH_ALEN);
1535 			memcpy(skb_push(frame, ETH_ALEN), dst, ETH_ALEN);
1536 		}
1537 
1538 		if (!ieee80211_frame_allowed(rx, fc)) {
1539 			if (skb == frame) /* last frame */
1540 				return RX_DROP_UNUSABLE;
1541 			dev_kfree_skb(frame);
1542 			continue;
1543 		}
1544 
1545 		ieee80211_deliver_skb(rx);
1546 	}
1547 
1548 	return RX_QUEUED;
1549 }
1550 
1551 #ifdef CONFIG_MAC80211_MESH
1552 static ieee80211_rx_result
1553 ieee80211_rx_h_mesh_fwding(struct ieee80211_rx_data *rx)
1554 {
1555 	struct ieee80211_hdr *hdr;
1556 	struct ieee80211s_hdr *mesh_hdr;
1557 	unsigned int hdrlen;
1558 	struct sk_buff *skb = rx->skb, *fwd_skb;
1559 
1560 	hdr = (struct ieee80211_hdr *) skb->data;
1561 	hdrlen = ieee80211_hdrlen(hdr->frame_control);
1562 	mesh_hdr = (struct ieee80211s_hdr *) (skb->data + hdrlen);
1563 
1564 	if (!ieee80211_is_data(hdr->frame_control))
1565 		return RX_CONTINUE;
1566 
1567 	if (!mesh_hdr->ttl)
1568 		/* illegal frame */
1569 		return RX_DROP_MONITOR;
1570 
1571 	if (mesh_hdr->flags & MESH_FLAGS_AE_A5_A6){
1572 		struct ieee80211_sub_if_data *sdata;
1573 		struct mesh_path *mppath;
1574 
1575 		sdata = IEEE80211_DEV_TO_SUB_IF(rx->dev);
1576 		rcu_read_lock();
1577 		mppath = mpp_path_lookup(mesh_hdr->eaddr2, sdata);
1578 		if (!mppath) {
1579 			mpp_path_add(mesh_hdr->eaddr2, hdr->addr4, sdata);
1580 		} else {
1581 			spin_lock_bh(&mppath->state_lock);
1582 			mppath->exp_time = jiffies;
1583 			if (compare_ether_addr(mppath->mpp, hdr->addr4) != 0)
1584 				memcpy(mppath->mpp, hdr->addr4, ETH_ALEN);
1585 			spin_unlock_bh(&mppath->state_lock);
1586 		}
1587 		rcu_read_unlock();
1588 	}
1589 
1590 	if (compare_ether_addr(rx->dev->dev_addr, hdr->addr3) == 0)
1591 		return RX_CONTINUE;
1592 
1593 	mesh_hdr->ttl--;
1594 
1595 	if (rx->flags & IEEE80211_RX_RA_MATCH) {
1596 		if (!mesh_hdr->ttl)
1597 			IEEE80211_IFSTA_MESH_CTR_INC(&rx->sdata->u.mesh,
1598 						     dropped_frames_ttl);
1599 		else {
1600 			struct ieee80211_hdr *fwd_hdr;
1601 			fwd_skb = skb_copy(skb, GFP_ATOMIC);
1602 
1603 			if (!fwd_skb && net_ratelimit())
1604 				printk(KERN_DEBUG "%s: failed to clone mesh frame\n",
1605 						   rx->dev->name);
1606 
1607 			fwd_hdr =  (struct ieee80211_hdr *) fwd_skb->data;
1608 			/*
1609 			 * Save TA to addr1 to send TA a path error if a
1610 			 * suitable next hop is not found
1611 			 */
1612 			memcpy(fwd_hdr->addr1, fwd_hdr->addr2, ETH_ALEN);
1613 			memcpy(fwd_hdr->addr2, rx->dev->dev_addr, ETH_ALEN);
1614 			fwd_skb->dev = rx->local->mdev;
1615 			fwd_skb->iif = rx->dev->ifindex;
1616 			dev_queue_xmit(fwd_skb);
1617 		}
1618 	}
1619 
1620 	if (is_multicast_ether_addr(hdr->addr3) ||
1621 	    rx->dev->flags & IFF_PROMISC)
1622 		return RX_CONTINUE;
1623 	else
1624 		return RX_DROP_MONITOR;
1625 }
1626 #endif
1627 
1628 static ieee80211_rx_result debug_noinline
1629 ieee80211_rx_h_data(struct ieee80211_rx_data *rx)
1630 {
1631 	struct net_device *dev = rx->dev;
1632 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
1633 	__le16 fc = hdr->frame_control;
1634 	int err;
1635 
1636 	if (unlikely(!ieee80211_is_data(hdr->frame_control)))
1637 		return RX_CONTINUE;
1638 
1639 	if (unlikely(!ieee80211_is_data_present(hdr->frame_control)))
1640 		return RX_DROP_MONITOR;
1641 
1642 	err = ieee80211_data_to_8023(rx);
1643 	if (unlikely(err))
1644 		return RX_DROP_UNUSABLE;
1645 
1646 	if (!ieee80211_frame_allowed(rx, fc))
1647 		return RX_DROP_MONITOR;
1648 
1649 	rx->skb->dev = dev;
1650 
1651 	dev->stats.rx_packets++;
1652 	dev->stats.rx_bytes += rx->skb->len;
1653 
1654 	ieee80211_deliver_skb(rx);
1655 
1656 	return RX_QUEUED;
1657 }
1658 
1659 static ieee80211_rx_result debug_noinline
1660 ieee80211_rx_h_ctrl(struct ieee80211_rx_data *rx)
1661 {
1662 	struct ieee80211_local *local = rx->local;
1663 	struct ieee80211_hw *hw = &local->hw;
1664 	struct sk_buff *skb = rx->skb;
1665 	struct ieee80211_bar *bar = (struct ieee80211_bar *)skb->data;
1666 	struct tid_ampdu_rx *tid_agg_rx;
1667 	u16 start_seq_num;
1668 	u16 tid;
1669 
1670 	if (likely(!ieee80211_is_ctl(bar->frame_control)))
1671 		return RX_CONTINUE;
1672 
1673 	if (ieee80211_is_back_req(bar->frame_control)) {
1674 		if (!rx->sta)
1675 			return RX_CONTINUE;
1676 		tid = le16_to_cpu(bar->control) >> 12;
1677 		if (rx->sta->ampdu_mlme.tid_state_rx[tid]
1678 					!= HT_AGG_STATE_OPERATIONAL)
1679 			return RX_CONTINUE;
1680 		tid_agg_rx = rx->sta->ampdu_mlme.tid_rx[tid];
1681 
1682 		start_seq_num = le16_to_cpu(bar->start_seq_num) >> 4;
1683 
1684 		/* reset session timer */
1685 		if (tid_agg_rx->timeout)
1686 			mod_timer(&tid_agg_rx->session_timer,
1687 				  TU_TO_EXP_TIME(tid_agg_rx->timeout));
1688 
1689 		/* manage reordering buffer according to requested */
1690 		/* sequence number */
1691 		rcu_read_lock();
1692 		ieee80211_sta_manage_reorder_buf(hw, tid_agg_rx, NULL, NULL,
1693 						 start_seq_num, 1);
1694 		rcu_read_unlock();
1695 		return RX_DROP_UNUSABLE;
1696 	}
1697 
1698 	return RX_CONTINUE;
1699 }
1700 
1701 static void ieee80211_process_sa_query_req(struct ieee80211_sub_if_data *sdata,
1702 					   struct ieee80211_mgmt *mgmt,
1703 					   size_t len)
1704 {
1705 	struct ieee80211_local *local = sdata->local;
1706 	struct sk_buff *skb;
1707 	struct ieee80211_mgmt *resp;
1708 
1709 	if (compare_ether_addr(mgmt->da, sdata->dev->dev_addr) != 0) {
1710 		/* Not to own unicast address */
1711 		return;
1712 	}
1713 
1714 	if (compare_ether_addr(mgmt->sa, sdata->u.mgd.bssid) != 0 ||
1715 	    compare_ether_addr(mgmt->bssid, sdata->u.mgd.bssid) != 0) {
1716 		/* Not from the current AP. */
1717 		return;
1718 	}
1719 
1720 	if (sdata->u.mgd.state == IEEE80211_STA_MLME_ASSOCIATE) {
1721 		/* Association in progress; ignore SA Query */
1722 		return;
1723 	}
1724 
1725 	if (len < 24 + 1 + sizeof(resp->u.action.u.sa_query)) {
1726 		/* Too short SA Query request frame */
1727 		return;
1728 	}
1729 
1730 	skb = dev_alloc_skb(sizeof(*resp) + local->hw.extra_tx_headroom);
1731 	if (skb == NULL)
1732 		return;
1733 
1734 	skb_reserve(skb, local->hw.extra_tx_headroom);
1735 	resp = (struct ieee80211_mgmt *) skb_put(skb, 24);
1736 	memset(resp, 0, 24);
1737 	memcpy(resp->da, mgmt->sa, ETH_ALEN);
1738 	memcpy(resp->sa, sdata->dev->dev_addr, ETH_ALEN);
1739 	memcpy(resp->bssid, sdata->u.mgd.bssid, ETH_ALEN);
1740 	resp->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
1741 					  IEEE80211_STYPE_ACTION);
1742 	skb_put(skb, 1 + sizeof(resp->u.action.u.sa_query));
1743 	resp->u.action.category = WLAN_CATEGORY_SA_QUERY;
1744 	resp->u.action.u.sa_query.action = WLAN_ACTION_SA_QUERY_RESPONSE;
1745 	memcpy(resp->u.action.u.sa_query.trans_id,
1746 	       mgmt->u.action.u.sa_query.trans_id,
1747 	       WLAN_SA_QUERY_TR_ID_LEN);
1748 
1749 	ieee80211_tx_skb(sdata, skb, 1);
1750 }
1751 
1752 static ieee80211_rx_result debug_noinline
1753 ieee80211_rx_h_action(struct ieee80211_rx_data *rx)
1754 {
1755 	struct ieee80211_local *local = rx->local;
1756 	struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(rx->dev);
1757 	struct ieee80211_mgmt *mgmt = (struct ieee80211_mgmt *) rx->skb->data;
1758 	struct ieee80211_bss *bss;
1759 	int len = rx->skb->len;
1760 
1761 	if (!ieee80211_is_action(mgmt->frame_control))
1762 		return RX_CONTINUE;
1763 
1764 	if (!rx->sta)
1765 		return RX_DROP_MONITOR;
1766 
1767 	if (!(rx->flags & IEEE80211_RX_RA_MATCH))
1768 		return RX_DROP_MONITOR;
1769 
1770 	if (ieee80211_drop_unencrypted(rx, mgmt->frame_control))
1771 		return RX_DROP_MONITOR;
1772 
1773 	/* all categories we currently handle have action_code */
1774 	if (len < IEEE80211_MIN_ACTION_SIZE + 1)
1775 		return RX_DROP_MONITOR;
1776 
1777 	switch (mgmt->u.action.category) {
1778 	case WLAN_CATEGORY_BACK:
1779 		/*
1780 		 * The aggregation code is not prepared to handle
1781 		 * anything but STA/AP due to the BSSID handling;
1782 		 * IBSS could work in the code but isn't supported
1783 		 * by drivers or the standard.
1784 		 */
1785 		if (sdata->vif.type != NL80211_IFTYPE_STATION &&
1786 		    sdata->vif.type != NL80211_IFTYPE_AP_VLAN &&
1787 		    sdata->vif.type != NL80211_IFTYPE_AP)
1788 			return RX_DROP_MONITOR;
1789 
1790 		switch (mgmt->u.action.u.addba_req.action_code) {
1791 		case WLAN_ACTION_ADDBA_REQ:
1792 			if (len < (IEEE80211_MIN_ACTION_SIZE +
1793 				   sizeof(mgmt->u.action.u.addba_req)))
1794 				return RX_DROP_MONITOR;
1795 			ieee80211_process_addba_request(local, rx->sta, mgmt, len);
1796 			break;
1797 		case WLAN_ACTION_ADDBA_RESP:
1798 			if (len < (IEEE80211_MIN_ACTION_SIZE +
1799 				   sizeof(mgmt->u.action.u.addba_resp)))
1800 				return RX_DROP_MONITOR;
1801 			ieee80211_process_addba_resp(local, rx->sta, mgmt, len);
1802 			break;
1803 		case WLAN_ACTION_DELBA:
1804 			if (len < (IEEE80211_MIN_ACTION_SIZE +
1805 				   sizeof(mgmt->u.action.u.delba)))
1806 				return RX_DROP_MONITOR;
1807 			ieee80211_process_delba(sdata, rx->sta, mgmt, len);
1808 			break;
1809 		}
1810 		break;
1811 	case WLAN_CATEGORY_SPECTRUM_MGMT:
1812 		if (local->hw.conf.channel->band != IEEE80211_BAND_5GHZ)
1813 			return RX_DROP_MONITOR;
1814 
1815 		if (sdata->vif.type != NL80211_IFTYPE_STATION)
1816 			return RX_DROP_MONITOR;
1817 
1818 		switch (mgmt->u.action.u.measurement.action_code) {
1819 		case WLAN_ACTION_SPCT_MSR_REQ:
1820 			if (len < (IEEE80211_MIN_ACTION_SIZE +
1821 				   sizeof(mgmt->u.action.u.measurement)))
1822 				return RX_DROP_MONITOR;
1823 			ieee80211_process_measurement_req(sdata, mgmt, len);
1824 			break;
1825 		case WLAN_ACTION_SPCT_CHL_SWITCH:
1826 			if (len < (IEEE80211_MIN_ACTION_SIZE +
1827 				   sizeof(mgmt->u.action.u.chan_switch)))
1828 				return RX_DROP_MONITOR;
1829 
1830 			if (memcmp(mgmt->bssid, sdata->u.mgd.bssid, ETH_ALEN))
1831 				return RX_DROP_MONITOR;
1832 
1833 			bss = ieee80211_rx_bss_get(local, sdata->u.mgd.bssid,
1834 					   local->hw.conf.channel->center_freq,
1835 					   sdata->u.mgd.ssid,
1836 					   sdata->u.mgd.ssid_len);
1837 			if (!bss)
1838 				return RX_DROP_MONITOR;
1839 
1840 			ieee80211_process_chanswitch(sdata,
1841 				     &mgmt->u.action.u.chan_switch.sw_elem, bss);
1842 			ieee80211_rx_bss_put(local, bss);
1843 			break;
1844 		}
1845 		break;
1846 	case WLAN_CATEGORY_SA_QUERY:
1847 		if (len < (IEEE80211_MIN_ACTION_SIZE +
1848 			   sizeof(mgmt->u.action.u.sa_query)))
1849 			return RX_DROP_MONITOR;
1850 		switch (mgmt->u.action.u.sa_query.action) {
1851 		case WLAN_ACTION_SA_QUERY_REQUEST:
1852 			if (sdata->vif.type != NL80211_IFTYPE_STATION)
1853 				return RX_DROP_MONITOR;
1854 			ieee80211_process_sa_query_req(sdata, mgmt, len);
1855 			break;
1856 		case WLAN_ACTION_SA_QUERY_RESPONSE:
1857 			/*
1858 			 * SA Query response is currently only used in AP mode
1859 			 * and it is processed in user space.
1860 			 */
1861 			return RX_CONTINUE;
1862 		}
1863 		break;
1864 	default:
1865 		return RX_CONTINUE;
1866 	}
1867 
1868 	rx->sta->rx_packets++;
1869 	dev_kfree_skb(rx->skb);
1870 	return RX_QUEUED;
1871 }
1872 
1873 static ieee80211_rx_result debug_noinline
1874 ieee80211_rx_h_mgmt(struct ieee80211_rx_data *rx)
1875 {
1876 	struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(rx->dev);
1877 	struct ieee80211_mgmt *mgmt = (struct ieee80211_mgmt *) rx->skb->data;
1878 
1879 	if (!(rx->flags & IEEE80211_RX_RA_MATCH))
1880 		return RX_DROP_MONITOR;
1881 
1882 	if (ieee80211_drop_unencrypted(rx, mgmt->frame_control))
1883 		return RX_DROP_MONITOR;
1884 
1885 	if (ieee80211_vif_is_mesh(&sdata->vif))
1886 		return ieee80211_mesh_rx_mgmt(sdata, rx->skb, rx->status);
1887 
1888 	if (sdata->vif.type == NL80211_IFTYPE_ADHOC)
1889 		return ieee80211_ibss_rx_mgmt(sdata, rx->skb, rx->status);
1890 
1891 	if (sdata->vif.type == NL80211_IFTYPE_STATION)
1892 		return ieee80211_sta_rx_mgmt(sdata, rx->skb, rx->status);
1893 
1894 	return RX_DROP_MONITOR;
1895 }
1896 
1897 static void ieee80211_rx_michael_mic_report(struct net_device *dev,
1898 					    struct ieee80211_hdr *hdr,
1899 					    struct ieee80211_rx_data *rx)
1900 {
1901 	int keyidx;
1902 	unsigned int hdrlen;
1903 
1904 	hdrlen = ieee80211_hdrlen(hdr->frame_control);
1905 	if (rx->skb->len >= hdrlen + 4)
1906 		keyidx = rx->skb->data[hdrlen + 3] >> 6;
1907 	else
1908 		keyidx = -1;
1909 
1910 	if (!rx->sta) {
1911 		/*
1912 		 * Some hardware seem to generate incorrect Michael MIC
1913 		 * reports; ignore them to avoid triggering countermeasures.
1914 		 */
1915 		goto ignore;
1916 	}
1917 
1918 	if (!ieee80211_has_protected(hdr->frame_control))
1919 		goto ignore;
1920 
1921 	if (rx->sdata->vif.type == NL80211_IFTYPE_AP && keyidx) {
1922 		/*
1923 		 * APs with pairwise keys should never receive Michael MIC
1924 		 * errors for non-zero keyidx because these are reserved for
1925 		 * group keys and only the AP is sending real multicast
1926 		 * frames in the BSS.
1927 		 */
1928 		goto ignore;
1929 	}
1930 
1931 	if (!ieee80211_is_data(hdr->frame_control) &&
1932 	    !ieee80211_is_auth(hdr->frame_control))
1933 		goto ignore;
1934 
1935 	mac80211_ev_michael_mic_failure(rx->sdata, keyidx, hdr);
1936  ignore:
1937 	dev_kfree_skb(rx->skb);
1938 	rx->skb = NULL;
1939 }
1940 
1941 /* TODO: use IEEE80211_RX_FRAGMENTED */
1942 static void ieee80211_rx_cooked_monitor(struct ieee80211_rx_data *rx)
1943 {
1944 	struct ieee80211_sub_if_data *sdata;
1945 	struct ieee80211_local *local = rx->local;
1946 	struct ieee80211_rtap_hdr {
1947 		struct ieee80211_radiotap_header hdr;
1948 		u8 flags;
1949 		u8 rate;
1950 		__le16 chan_freq;
1951 		__le16 chan_flags;
1952 	} __attribute__ ((packed)) *rthdr;
1953 	struct sk_buff *skb = rx->skb, *skb2;
1954 	struct net_device *prev_dev = NULL;
1955 	struct ieee80211_rx_status *status = rx->status;
1956 
1957 	if (rx->flags & IEEE80211_RX_CMNTR_REPORTED)
1958 		goto out_free_skb;
1959 
1960 	if (skb_headroom(skb) < sizeof(*rthdr) &&
1961 	    pskb_expand_head(skb, sizeof(*rthdr), 0, GFP_ATOMIC))
1962 		goto out_free_skb;
1963 
1964 	rthdr = (void *)skb_push(skb, sizeof(*rthdr));
1965 	memset(rthdr, 0, sizeof(*rthdr));
1966 	rthdr->hdr.it_len = cpu_to_le16(sizeof(*rthdr));
1967 	rthdr->hdr.it_present =
1968 		cpu_to_le32((1 << IEEE80211_RADIOTAP_FLAGS) |
1969 			    (1 << IEEE80211_RADIOTAP_RATE) |
1970 			    (1 << IEEE80211_RADIOTAP_CHANNEL));
1971 
1972 	rthdr->rate = rx->rate->bitrate / 5;
1973 	rthdr->chan_freq = cpu_to_le16(status->freq);
1974 
1975 	if (status->band == IEEE80211_BAND_5GHZ)
1976 		rthdr->chan_flags = cpu_to_le16(IEEE80211_CHAN_OFDM |
1977 						IEEE80211_CHAN_5GHZ);
1978 	else
1979 		rthdr->chan_flags = cpu_to_le16(IEEE80211_CHAN_DYN |
1980 						IEEE80211_CHAN_2GHZ);
1981 
1982 	skb_set_mac_header(skb, 0);
1983 	skb->ip_summed = CHECKSUM_UNNECESSARY;
1984 	skb->pkt_type = PACKET_OTHERHOST;
1985 	skb->protocol = htons(ETH_P_802_2);
1986 
1987 	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
1988 		if (!netif_running(sdata->dev))
1989 			continue;
1990 
1991 		if (sdata->vif.type != NL80211_IFTYPE_MONITOR ||
1992 		    !(sdata->u.mntr_flags & MONITOR_FLAG_COOK_FRAMES))
1993 			continue;
1994 
1995 		if (prev_dev) {
1996 			skb2 = skb_clone(skb, GFP_ATOMIC);
1997 			if (skb2) {
1998 				skb2->dev = prev_dev;
1999 				netif_rx(skb2);
2000 			}
2001 		}
2002 
2003 		prev_dev = sdata->dev;
2004 		sdata->dev->stats.rx_packets++;
2005 		sdata->dev->stats.rx_bytes += skb->len;
2006 	}
2007 
2008 	if (prev_dev) {
2009 		skb->dev = prev_dev;
2010 		netif_rx(skb);
2011 		skb = NULL;
2012 	} else
2013 		goto out_free_skb;
2014 
2015 	rx->flags |= IEEE80211_RX_CMNTR_REPORTED;
2016 	return;
2017 
2018  out_free_skb:
2019 	dev_kfree_skb(skb);
2020 }
2021 
2022 
2023 static void ieee80211_invoke_rx_handlers(struct ieee80211_sub_if_data *sdata,
2024 					 struct ieee80211_rx_data *rx,
2025 					 struct sk_buff *skb)
2026 {
2027 	ieee80211_rx_result res = RX_DROP_MONITOR;
2028 
2029 	rx->skb = skb;
2030 	rx->sdata = sdata;
2031 	rx->dev = sdata->dev;
2032 
2033 #define CALL_RXH(rxh)			\
2034 	do {				\
2035 		res = rxh(rx);		\
2036 		if (res != RX_CONTINUE)	\
2037 			goto rxh_done;  \
2038 	} while (0);
2039 
2040 	CALL_RXH(ieee80211_rx_h_passive_scan)
2041 	CALL_RXH(ieee80211_rx_h_check)
2042 	CALL_RXH(ieee80211_rx_h_decrypt)
2043 	CALL_RXH(ieee80211_rx_h_check_more_data)
2044 	CALL_RXH(ieee80211_rx_h_sta_process)
2045 	CALL_RXH(ieee80211_rx_h_defragment)
2046 	CALL_RXH(ieee80211_rx_h_ps_poll)
2047 	CALL_RXH(ieee80211_rx_h_michael_mic_verify)
2048 	/* must be after MMIC verify so header is counted in MPDU mic */
2049 	CALL_RXH(ieee80211_rx_h_remove_qos_control)
2050 	CALL_RXH(ieee80211_rx_h_amsdu)
2051 #ifdef CONFIG_MAC80211_MESH
2052 	if (ieee80211_vif_is_mesh(&sdata->vif))
2053 		CALL_RXH(ieee80211_rx_h_mesh_fwding);
2054 #endif
2055 	CALL_RXH(ieee80211_rx_h_data)
2056 	CALL_RXH(ieee80211_rx_h_ctrl)
2057 	CALL_RXH(ieee80211_rx_h_action)
2058 	CALL_RXH(ieee80211_rx_h_mgmt)
2059 
2060 #undef CALL_RXH
2061 
2062  rxh_done:
2063 	switch (res) {
2064 	case RX_DROP_MONITOR:
2065 		I802_DEBUG_INC(sdata->local->rx_handlers_drop);
2066 		if (rx->sta)
2067 			rx->sta->rx_dropped++;
2068 		/* fall through */
2069 	case RX_CONTINUE:
2070 		ieee80211_rx_cooked_monitor(rx);
2071 		break;
2072 	case RX_DROP_UNUSABLE:
2073 		I802_DEBUG_INC(sdata->local->rx_handlers_drop);
2074 		if (rx->sta)
2075 			rx->sta->rx_dropped++;
2076 		dev_kfree_skb(rx->skb);
2077 		break;
2078 	case RX_QUEUED:
2079 		I802_DEBUG_INC(sdata->local->rx_handlers_queued);
2080 		break;
2081 	}
2082 }
2083 
2084 /* main receive path */
2085 
2086 static int prepare_for_handlers(struct ieee80211_sub_if_data *sdata,
2087 				struct ieee80211_rx_data *rx,
2088 				struct ieee80211_hdr *hdr)
2089 {
2090 	u8 *bssid = ieee80211_get_bssid(hdr, rx->skb->len, sdata->vif.type);
2091 	int multicast = is_multicast_ether_addr(hdr->addr1);
2092 
2093 	switch (sdata->vif.type) {
2094 	case NL80211_IFTYPE_STATION:
2095 		if (!bssid)
2096 			return 0;
2097 		if (!ieee80211_bssid_match(bssid, sdata->u.mgd.bssid)) {
2098 			if (!(rx->flags & IEEE80211_RX_IN_SCAN))
2099 				return 0;
2100 			rx->flags &= ~IEEE80211_RX_RA_MATCH;
2101 		} else if (!multicast &&
2102 			   compare_ether_addr(sdata->dev->dev_addr,
2103 					      hdr->addr1) != 0) {
2104 			if (!(sdata->dev->flags & IFF_PROMISC))
2105 				return 0;
2106 			rx->flags &= ~IEEE80211_RX_RA_MATCH;
2107 		}
2108 		break;
2109 	case NL80211_IFTYPE_ADHOC:
2110 		if (!bssid)
2111 			return 0;
2112 		if (ieee80211_is_beacon(hdr->frame_control)) {
2113 			return 1;
2114 		}
2115 		else if (!ieee80211_bssid_match(bssid, sdata->u.ibss.bssid)) {
2116 			if (!(rx->flags & IEEE80211_RX_IN_SCAN))
2117 				return 0;
2118 			rx->flags &= ~IEEE80211_RX_RA_MATCH;
2119 		} else if (!multicast &&
2120 			   compare_ether_addr(sdata->dev->dev_addr,
2121 					      hdr->addr1) != 0) {
2122 			if (!(sdata->dev->flags & IFF_PROMISC))
2123 				return 0;
2124 			rx->flags &= ~IEEE80211_RX_RA_MATCH;
2125 		} else if (!rx->sta) {
2126 			int rate_idx;
2127 			if (rx->status->flag & RX_FLAG_HT)
2128 				rate_idx = 0; /* TODO: HT rates */
2129 			else
2130 				rate_idx = rx->status->rate_idx;
2131 			rx->sta = ieee80211_ibss_add_sta(sdata, bssid, hdr->addr2,
2132 				BIT(rate_idx));
2133 		}
2134 		break;
2135 	case NL80211_IFTYPE_MESH_POINT:
2136 		if (!multicast &&
2137 		    compare_ether_addr(sdata->dev->dev_addr,
2138 				       hdr->addr1) != 0) {
2139 			if (!(sdata->dev->flags & IFF_PROMISC))
2140 				return 0;
2141 
2142 			rx->flags &= ~IEEE80211_RX_RA_MATCH;
2143 		}
2144 		break;
2145 	case NL80211_IFTYPE_AP_VLAN:
2146 	case NL80211_IFTYPE_AP:
2147 		if (!bssid) {
2148 			if (compare_ether_addr(sdata->dev->dev_addr,
2149 					       hdr->addr1))
2150 				return 0;
2151 		} else if (!ieee80211_bssid_match(bssid,
2152 					sdata->dev->dev_addr)) {
2153 			if (!(rx->flags & IEEE80211_RX_IN_SCAN))
2154 				return 0;
2155 			rx->flags &= ~IEEE80211_RX_RA_MATCH;
2156 		}
2157 		break;
2158 	case NL80211_IFTYPE_WDS:
2159 		if (bssid || !ieee80211_is_data(hdr->frame_control))
2160 			return 0;
2161 		if (compare_ether_addr(sdata->u.wds.remote_addr, hdr->addr2))
2162 			return 0;
2163 		break;
2164 	case NL80211_IFTYPE_MONITOR:
2165 		/* take everything */
2166 		break;
2167 	case NL80211_IFTYPE_UNSPECIFIED:
2168 	case __NL80211_IFTYPE_AFTER_LAST:
2169 		/* should never get here */
2170 		WARN_ON(1);
2171 		break;
2172 	}
2173 
2174 	return 1;
2175 }
2176 
2177 /*
2178  * This is the actual Rx frames handler. as it blongs to Rx path it must
2179  * be called with rcu_read_lock protection.
2180  */
2181 static void __ieee80211_rx_handle_packet(struct ieee80211_hw *hw,
2182 					 struct sk_buff *skb,
2183 					 struct ieee80211_rx_status *status,
2184 					 struct ieee80211_rate *rate)
2185 {
2186 	struct ieee80211_local *local = hw_to_local(hw);
2187 	struct ieee80211_sub_if_data *sdata;
2188 	struct ieee80211_hdr *hdr;
2189 	struct ieee80211_rx_data rx;
2190 	int prepares;
2191 	struct ieee80211_sub_if_data *prev = NULL;
2192 	struct sk_buff *skb_new;
2193 
2194 	hdr = (struct ieee80211_hdr *)skb->data;
2195 	memset(&rx, 0, sizeof(rx));
2196 	rx.skb = skb;
2197 	rx.local = local;
2198 
2199 	rx.status = status;
2200 	rx.rate = rate;
2201 
2202 	if (ieee80211_is_data(hdr->frame_control) || ieee80211_is_mgmt(hdr->frame_control))
2203 		local->dot11ReceivedFragmentCount++;
2204 
2205 	rx.sta = sta_info_get(local, hdr->addr2);
2206 	if (rx.sta) {
2207 		rx.sdata = rx.sta->sdata;
2208 		rx.dev = rx.sta->sdata->dev;
2209 	}
2210 
2211 	if ((status->flag & RX_FLAG_MMIC_ERROR)) {
2212 		ieee80211_rx_michael_mic_report(local->mdev, hdr, &rx);
2213 		return;
2214 	}
2215 
2216 	if (unlikely(local->sw_scanning || local->hw_scanning))
2217 		rx.flags |= IEEE80211_RX_IN_SCAN;
2218 
2219 	ieee80211_parse_qos(&rx);
2220 	ieee80211_verify_alignment(&rx);
2221 
2222 	skb = rx.skb;
2223 
2224 	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
2225 		if (!netif_running(sdata->dev))
2226 			continue;
2227 
2228 		if (sdata->vif.type == NL80211_IFTYPE_MONITOR)
2229 			continue;
2230 
2231 		rx.flags |= IEEE80211_RX_RA_MATCH;
2232 		prepares = prepare_for_handlers(sdata, &rx, hdr);
2233 
2234 		if (!prepares)
2235 			continue;
2236 
2237 		/*
2238 		 * frame is destined for this interface, but if it's not
2239 		 * also for the previous one we handle that after the
2240 		 * loop to avoid copying the SKB once too much
2241 		 */
2242 
2243 		if (!prev) {
2244 			prev = sdata;
2245 			continue;
2246 		}
2247 
2248 		/*
2249 		 * frame was destined for the previous interface
2250 		 * so invoke RX handlers for it
2251 		 */
2252 
2253 		skb_new = skb_copy(skb, GFP_ATOMIC);
2254 		if (!skb_new) {
2255 			if (net_ratelimit())
2256 				printk(KERN_DEBUG "%s: failed to copy "
2257 				       "multicast frame for %s\n",
2258 				       wiphy_name(local->hw.wiphy),
2259 				       prev->dev->name);
2260 			continue;
2261 		}
2262 		ieee80211_invoke_rx_handlers(prev, &rx, skb_new);
2263 		prev = sdata;
2264 	}
2265 	if (prev)
2266 		ieee80211_invoke_rx_handlers(prev, &rx, skb);
2267 	else
2268 		dev_kfree_skb(skb);
2269 }
2270 
2271 #define SEQ_MODULO 0x1000
2272 #define SEQ_MASK   0xfff
2273 
2274 static inline int seq_less(u16 sq1, u16 sq2)
2275 {
2276 	return ((sq1 - sq2) & SEQ_MASK) > (SEQ_MODULO >> 1);
2277 }
2278 
2279 static inline u16 seq_inc(u16 sq)
2280 {
2281 	return (sq + 1) & SEQ_MASK;
2282 }
2283 
2284 static inline u16 seq_sub(u16 sq1, u16 sq2)
2285 {
2286 	return (sq1 - sq2) & SEQ_MASK;
2287 }
2288 
2289 
2290 /*
2291  * As it function blongs to Rx path it must be called with
2292  * the proper rcu_read_lock protection for its flow.
2293  */
2294 static u8 ieee80211_sta_manage_reorder_buf(struct ieee80211_hw *hw,
2295 					   struct tid_ampdu_rx *tid_agg_rx,
2296 					   struct sk_buff *skb,
2297 					   struct ieee80211_rx_status *rxstatus,
2298 					   u16 mpdu_seq_num,
2299 					   int bar_req)
2300 {
2301 	struct ieee80211_local *local = hw_to_local(hw);
2302 	struct ieee80211_rx_status status;
2303 	u16 head_seq_num, buf_size;
2304 	int index;
2305 	struct ieee80211_supported_band *sband;
2306 	struct ieee80211_rate *rate;
2307 
2308 	buf_size = tid_agg_rx->buf_size;
2309 	head_seq_num = tid_agg_rx->head_seq_num;
2310 
2311 	/* frame with out of date sequence number */
2312 	if (seq_less(mpdu_seq_num, head_seq_num)) {
2313 		dev_kfree_skb(skb);
2314 		return 1;
2315 	}
2316 
2317 	/* if frame sequence number exceeds our buffering window size or
2318 	 * block Ack Request arrived - release stored frames */
2319 	if ((!seq_less(mpdu_seq_num, head_seq_num + buf_size)) || (bar_req)) {
2320 		/* new head to the ordering buffer */
2321 		if (bar_req)
2322 			head_seq_num = mpdu_seq_num;
2323 		else
2324 			head_seq_num =
2325 				seq_inc(seq_sub(mpdu_seq_num, buf_size));
2326 		/* release stored frames up to new head to stack */
2327 		while (seq_less(tid_agg_rx->head_seq_num, head_seq_num)) {
2328 			index = seq_sub(tid_agg_rx->head_seq_num,
2329 				tid_agg_rx->ssn)
2330 				% tid_agg_rx->buf_size;
2331 
2332 			if (tid_agg_rx->reorder_buf[index]) {
2333 				/* release the reordered frames to stack */
2334 				memcpy(&status,
2335 					tid_agg_rx->reorder_buf[index]->cb,
2336 					sizeof(status));
2337 				sband = local->hw.wiphy->bands[status.band];
2338 				if (status.flag & RX_FLAG_HT) {
2339 					/* TODO: HT rates */
2340 					rate = sband->bitrates;
2341 				} else {
2342 					rate = &sband->bitrates
2343 						[status.rate_idx];
2344 				}
2345 				__ieee80211_rx_handle_packet(hw,
2346 					tid_agg_rx->reorder_buf[index],
2347 					&status, rate);
2348 				tid_agg_rx->stored_mpdu_num--;
2349 				tid_agg_rx->reorder_buf[index] = NULL;
2350 			}
2351 			tid_agg_rx->head_seq_num =
2352 				seq_inc(tid_agg_rx->head_seq_num);
2353 		}
2354 		if (bar_req)
2355 			return 1;
2356 	}
2357 
2358 	/* now the new frame is always in the range of the reordering */
2359 	/* buffer window */
2360 	index = seq_sub(mpdu_seq_num, tid_agg_rx->ssn)
2361 				% tid_agg_rx->buf_size;
2362 	/* check if we already stored this frame */
2363 	if (tid_agg_rx->reorder_buf[index]) {
2364 		dev_kfree_skb(skb);
2365 		return 1;
2366 	}
2367 
2368 	/* if arrived mpdu is in the right order and nothing else stored */
2369 	/* release it immediately */
2370 	if (mpdu_seq_num == tid_agg_rx->head_seq_num &&
2371 			tid_agg_rx->stored_mpdu_num == 0) {
2372 		tid_agg_rx->head_seq_num =
2373 			seq_inc(tid_agg_rx->head_seq_num);
2374 		return 0;
2375 	}
2376 
2377 	/* put the frame in the reordering buffer */
2378 	tid_agg_rx->reorder_buf[index] = skb;
2379 	memcpy(tid_agg_rx->reorder_buf[index]->cb, rxstatus,
2380 	       sizeof(*rxstatus));
2381 	tid_agg_rx->stored_mpdu_num++;
2382 	/* release the buffer until next missing frame */
2383 	index = seq_sub(tid_agg_rx->head_seq_num, tid_agg_rx->ssn)
2384 						% tid_agg_rx->buf_size;
2385 	while (tid_agg_rx->reorder_buf[index]) {
2386 		/* release the reordered frame back to stack */
2387 		memcpy(&status, tid_agg_rx->reorder_buf[index]->cb,
2388 			sizeof(status));
2389 		sband = local->hw.wiphy->bands[status.band];
2390 		if (status.flag & RX_FLAG_HT)
2391 			rate = sband->bitrates; /* TODO: HT rates */
2392 		else
2393 			rate = &sband->bitrates[status.rate_idx];
2394 		__ieee80211_rx_handle_packet(hw, tid_agg_rx->reorder_buf[index],
2395 					     &status, rate);
2396 		tid_agg_rx->stored_mpdu_num--;
2397 		tid_agg_rx->reorder_buf[index] = NULL;
2398 		tid_agg_rx->head_seq_num = seq_inc(tid_agg_rx->head_seq_num);
2399 		index =	seq_sub(tid_agg_rx->head_seq_num,
2400 			tid_agg_rx->ssn) % tid_agg_rx->buf_size;
2401 	}
2402 	return 1;
2403 }
2404 
2405 static u8 ieee80211_rx_reorder_ampdu(struct ieee80211_local *local,
2406 				     struct sk_buff *skb,
2407 				     struct ieee80211_rx_status *status)
2408 {
2409 	struct ieee80211_hw *hw = &local->hw;
2410 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
2411 	struct sta_info *sta;
2412 	struct tid_ampdu_rx *tid_agg_rx;
2413 	u16 sc;
2414 	u16 mpdu_seq_num;
2415 	u8 ret = 0;
2416 	int tid;
2417 
2418 	sta = sta_info_get(local, hdr->addr2);
2419 	if (!sta)
2420 		return ret;
2421 
2422 	/* filter the QoS data rx stream according to
2423 	 * STA/TID and check if this STA/TID is on aggregation */
2424 	if (!ieee80211_is_data_qos(hdr->frame_control))
2425 		goto end_reorder;
2426 
2427 	tid = *ieee80211_get_qos_ctl(hdr) & IEEE80211_QOS_CTL_TID_MASK;
2428 
2429 	if (sta->ampdu_mlme.tid_state_rx[tid] != HT_AGG_STATE_OPERATIONAL)
2430 		goto end_reorder;
2431 
2432 	tid_agg_rx = sta->ampdu_mlme.tid_rx[tid];
2433 
2434 	/* qos null data frames are excluded */
2435 	if (unlikely(hdr->frame_control & cpu_to_le16(IEEE80211_STYPE_NULLFUNC)))
2436 		goto end_reorder;
2437 
2438 	/* new un-ordered ampdu frame - process it */
2439 
2440 	/* reset session timer */
2441 	if (tid_agg_rx->timeout)
2442 		mod_timer(&tid_agg_rx->session_timer,
2443 			  TU_TO_EXP_TIME(tid_agg_rx->timeout));
2444 
2445 	/* if this mpdu is fragmented - terminate rx aggregation session */
2446 	sc = le16_to_cpu(hdr->seq_ctrl);
2447 	if (sc & IEEE80211_SCTL_FRAG) {
2448 		ieee80211_sta_stop_rx_ba_session(sta->sdata, sta->sta.addr,
2449 			tid, 0, WLAN_REASON_QSTA_REQUIRE_SETUP);
2450 		ret = 1;
2451 		goto end_reorder;
2452 	}
2453 
2454 	/* according to mpdu sequence number deal with reordering buffer */
2455 	mpdu_seq_num = (sc & IEEE80211_SCTL_SEQ) >> 4;
2456 	ret = ieee80211_sta_manage_reorder_buf(hw, tid_agg_rx, skb, status,
2457 						mpdu_seq_num, 0);
2458  end_reorder:
2459 	return ret;
2460 }
2461 
2462 /*
2463  * This is the receive path handler. It is called by a low level driver when an
2464  * 802.11 MPDU is received from the hardware.
2465  */
2466 void __ieee80211_rx(struct ieee80211_hw *hw, struct sk_buff *skb,
2467 		    struct ieee80211_rx_status *status)
2468 {
2469 	struct ieee80211_local *local = hw_to_local(hw);
2470 	struct ieee80211_rate *rate = NULL;
2471 	struct ieee80211_supported_band *sband;
2472 
2473 	if (status->band < 0 ||
2474 	    status->band >= IEEE80211_NUM_BANDS) {
2475 		WARN_ON(1);
2476 		return;
2477 	}
2478 
2479 	sband = local->hw.wiphy->bands[status->band];
2480 	if (!sband) {
2481 		WARN_ON(1);
2482 		return;
2483 	}
2484 
2485 	if (status->flag & RX_FLAG_HT) {
2486 		/* rate_idx is MCS index */
2487 		if (WARN_ON(status->rate_idx < 0 ||
2488 			    status->rate_idx >= 76))
2489 			return;
2490 		/* HT rates are not in the table - use the highest legacy rate
2491 		 * for now since other parts of mac80211 may not yet be fully
2492 		 * MCS aware. */
2493 		rate = &sband->bitrates[sband->n_bitrates - 1];
2494 	} else {
2495 		if (WARN_ON(status->rate_idx < 0 ||
2496 			    status->rate_idx >= sband->n_bitrates))
2497 			return;
2498 		rate = &sband->bitrates[status->rate_idx];
2499 	}
2500 
2501 	/*
2502 	 * key references and virtual interfaces are protected using RCU
2503 	 * and this requires that we are in a read-side RCU section during
2504 	 * receive processing
2505 	 */
2506 	rcu_read_lock();
2507 
2508 	/*
2509 	 * Frames with failed FCS/PLCP checksum are not returned,
2510 	 * all other frames are returned without radiotap header
2511 	 * if it was previously present.
2512 	 * Also, frames with less than 16 bytes are dropped.
2513 	 */
2514 	skb = ieee80211_rx_monitor(local, skb, status, rate);
2515 	if (!skb) {
2516 		rcu_read_unlock();
2517 		return;
2518 	}
2519 
2520 	if (!ieee80211_rx_reorder_ampdu(local, skb, status))
2521 		__ieee80211_rx_handle_packet(hw, skb, status, rate);
2522 
2523 	rcu_read_unlock();
2524 }
2525 EXPORT_SYMBOL(__ieee80211_rx);
2526 
2527 /* This is a version of the rx handler that can be called from hard irq
2528  * context. Post the skb on the queue and schedule the tasklet */
2529 void ieee80211_rx_irqsafe(struct ieee80211_hw *hw, struct sk_buff *skb,
2530 			  struct ieee80211_rx_status *status)
2531 {
2532 	struct ieee80211_local *local = hw_to_local(hw);
2533 
2534 	BUILD_BUG_ON(sizeof(struct ieee80211_rx_status) > sizeof(skb->cb));
2535 
2536 	skb->dev = local->mdev;
2537 	/* copy status into skb->cb for use by tasklet */
2538 	memcpy(skb->cb, status, sizeof(*status));
2539 	skb->pkt_type = IEEE80211_RX_MSG;
2540 	skb_queue_tail(&local->skb_queue, skb);
2541 	tasklet_schedule(&local->tasklet);
2542 }
2543 EXPORT_SYMBOL(ieee80211_rx_irqsafe);
2544