xref: /linux/net/mac80211/rx.c (revision a67ff6a54095e27093ea501fb143fefe51a536c2)
1 /*
2  * Copyright 2002-2005, Instant802 Networks, Inc.
3  * Copyright 2005-2006, Devicescape Software, Inc.
4  * Copyright 2006-2007	Jiri Benc <jbenc@suse.cz>
5  * Copyright 2007-2010	Johannes Berg <johannes@sipsolutions.net>
6  *
7  * This program is free software; you can redistribute it and/or modify
8  * it under the terms of the GNU General Public License version 2 as
9  * published by the Free Software Foundation.
10  */
11 
12 #include <linux/jiffies.h>
13 #include <linux/slab.h>
14 #include <linux/kernel.h>
15 #include <linux/skbuff.h>
16 #include <linux/netdevice.h>
17 #include <linux/etherdevice.h>
18 #include <linux/rcupdate.h>
19 #include <linux/export.h>
20 #include <net/mac80211.h>
21 #include <net/ieee80211_radiotap.h>
22 
23 #include "ieee80211_i.h"
24 #include "driver-ops.h"
25 #include "led.h"
26 #include "mesh.h"
27 #include "wep.h"
28 #include "wpa.h"
29 #include "tkip.h"
30 #include "wme.h"
31 
32 /*
33  * monitor mode reception
34  *
35  * This function cleans up the SKB, i.e. it removes all the stuff
36  * only useful for monitoring.
37  */
38 static struct sk_buff *remove_monitor_info(struct ieee80211_local *local,
39 					   struct sk_buff *skb)
40 {
41 	if (local->hw.flags & IEEE80211_HW_RX_INCLUDES_FCS) {
42 		if (likely(skb->len > FCS_LEN))
43 			__pskb_trim(skb, skb->len - FCS_LEN);
44 		else {
45 			/* driver bug */
46 			WARN_ON(1);
47 			dev_kfree_skb(skb);
48 			skb = NULL;
49 		}
50 	}
51 
52 	return skb;
53 }
54 
55 static inline int should_drop_frame(struct sk_buff *skb,
56 				    int present_fcs_len)
57 {
58 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
59 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
60 
61 	if (status->flag & (RX_FLAG_FAILED_FCS_CRC | RX_FLAG_FAILED_PLCP_CRC))
62 		return 1;
63 	if (unlikely(skb->len < 16 + present_fcs_len))
64 		return 1;
65 	if (ieee80211_is_ctl(hdr->frame_control) &&
66 	    !ieee80211_is_pspoll(hdr->frame_control) &&
67 	    !ieee80211_is_back_req(hdr->frame_control))
68 		return 1;
69 	return 0;
70 }
71 
72 static int
73 ieee80211_rx_radiotap_len(struct ieee80211_local *local,
74 			  struct ieee80211_rx_status *status)
75 {
76 	int len;
77 
78 	/* always present fields */
79 	len = sizeof(struct ieee80211_radiotap_header) + 9;
80 
81 	if (status->flag & RX_FLAG_MACTIME_MPDU)
82 		len += 8;
83 	if (local->hw.flags & IEEE80211_HW_SIGNAL_DBM)
84 		len += 1;
85 
86 	if (len & 1) /* padding for RX_FLAGS if necessary */
87 		len++;
88 
89 	if (status->flag & RX_FLAG_HT) /* HT info */
90 		len += 3;
91 
92 	return len;
93 }
94 
95 /*
96  * ieee80211_add_rx_radiotap_header - add radiotap header
97  *
98  * add a radiotap header containing all the fields which the hardware provided.
99  */
100 static void
101 ieee80211_add_rx_radiotap_header(struct ieee80211_local *local,
102 				 struct sk_buff *skb,
103 				 struct ieee80211_rate *rate,
104 				 int rtap_len)
105 {
106 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
107 	struct ieee80211_radiotap_header *rthdr;
108 	unsigned char *pos;
109 	u16 rx_flags = 0;
110 
111 	rthdr = (struct ieee80211_radiotap_header *)skb_push(skb, rtap_len);
112 	memset(rthdr, 0, rtap_len);
113 
114 	/* radiotap header, set always present flags */
115 	rthdr->it_present =
116 		cpu_to_le32((1 << IEEE80211_RADIOTAP_FLAGS) |
117 			    (1 << IEEE80211_RADIOTAP_CHANNEL) |
118 			    (1 << IEEE80211_RADIOTAP_ANTENNA) |
119 			    (1 << IEEE80211_RADIOTAP_RX_FLAGS));
120 	rthdr->it_len = cpu_to_le16(rtap_len);
121 
122 	pos = (unsigned char *)(rthdr+1);
123 
124 	/* the order of the following fields is important */
125 
126 	/* IEEE80211_RADIOTAP_TSFT */
127 	if (status->flag & RX_FLAG_MACTIME_MPDU) {
128 		put_unaligned_le64(status->mactime, pos);
129 		rthdr->it_present |=
130 			cpu_to_le32(1 << IEEE80211_RADIOTAP_TSFT);
131 		pos += 8;
132 	}
133 
134 	/* IEEE80211_RADIOTAP_FLAGS */
135 	if (local->hw.flags & IEEE80211_HW_RX_INCLUDES_FCS)
136 		*pos |= IEEE80211_RADIOTAP_F_FCS;
137 	if (status->flag & (RX_FLAG_FAILED_FCS_CRC | RX_FLAG_FAILED_PLCP_CRC))
138 		*pos |= IEEE80211_RADIOTAP_F_BADFCS;
139 	if (status->flag & RX_FLAG_SHORTPRE)
140 		*pos |= IEEE80211_RADIOTAP_F_SHORTPRE;
141 	pos++;
142 
143 	/* IEEE80211_RADIOTAP_RATE */
144 	if (status->flag & RX_FLAG_HT) {
145 		/*
146 		 * MCS information is a separate field in radiotap,
147 		 * added below. The byte here is needed as padding
148 		 * for the channel though, so initialise it to 0.
149 		 */
150 		*pos = 0;
151 	} else {
152 		rthdr->it_present |= cpu_to_le32(1 << IEEE80211_RADIOTAP_RATE);
153 		*pos = rate->bitrate / 5;
154 	}
155 	pos++;
156 
157 	/* IEEE80211_RADIOTAP_CHANNEL */
158 	put_unaligned_le16(status->freq, pos);
159 	pos += 2;
160 	if (status->band == IEEE80211_BAND_5GHZ)
161 		put_unaligned_le16(IEEE80211_CHAN_OFDM | IEEE80211_CHAN_5GHZ,
162 				   pos);
163 	else if (status->flag & RX_FLAG_HT)
164 		put_unaligned_le16(IEEE80211_CHAN_DYN | IEEE80211_CHAN_2GHZ,
165 				   pos);
166 	else if (rate->flags & IEEE80211_RATE_ERP_G)
167 		put_unaligned_le16(IEEE80211_CHAN_OFDM | IEEE80211_CHAN_2GHZ,
168 				   pos);
169 	else
170 		put_unaligned_le16(IEEE80211_CHAN_CCK | IEEE80211_CHAN_2GHZ,
171 				   pos);
172 	pos += 2;
173 
174 	/* IEEE80211_RADIOTAP_DBM_ANTSIGNAL */
175 	if (local->hw.flags & IEEE80211_HW_SIGNAL_DBM) {
176 		*pos = status->signal;
177 		rthdr->it_present |=
178 			cpu_to_le32(1 << IEEE80211_RADIOTAP_DBM_ANTSIGNAL);
179 		pos++;
180 	}
181 
182 	/* IEEE80211_RADIOTAP_LOCK_QUALITY is missing */
183 
184 	/* IEEE80211_RADIOTAP_ANTENNA */
185 	*pos = status->antenna;
186 	pos++;
187 
188 	/* IEEE80211_RADIOTAP_DB_ANTNOISE is not used */
189 
190 	/* IEEE80211_RADIOTAP_RX_FLAGS */
191 	/* ensure 2 byte alignment for the 2 byte field as required */
192 	if ((pos - (u8 *)rthdr) & 1)
193 		pos++;
194 	if (status->flag & RX_FLAG_FAILED_PLCP_CRC)
195 		rx_flags |= IEEE80211_RADIOTAP_F_RX_BADPLCP;
196 	put_unaligned_le16(rx_flags, pos);
197 	pos += 2;
198 
199 	if (status->flag & RX_FLAG_HT) {
200 		rthdr->it_present |= cpu_to_le32(1 << IEEE80211_RADIOTAP_MCS);
201 		*pos++ = IEEE80211_RADIOTAP_MCS_HAVE_MCS |
202 			 IEEE80211_RADIOTAP_MCS_HAVE_GI |
203 			 IEEE80211_RADIOTAP_MCS_HAVE_BW;
204 		*pos = 0;
205 		if (status->flag & RX_FLAG_SHORT_GI)
206 			*pos |= IEEE80211_RADIOTAP_MCS_SGI;
207 		if (status->flag & RX_FLAG_40MHZ)
208 			*pos |= IEEE80211_RADIOTAP_MCS_BW_40;
209 		pos++;
210 		*pos++ = status->rate_idx;
211 	}
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_rate *rate)
222 {
223 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(origskb);
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 
230 	/*
231 	 * First, we may need to make a copy of the skb because
232 	 *  (1) we need to modify it for radiotap (if not present), and
233 	 *  (2) the other RX handlers will modify the skb we got.
234 	 *
235 	 * We don't need to, of course, if we aren't going to return
236 	 * the SKB because it has a bad FCS/PLCP checksum.
237 	 */
238 
239 	/* room for the radiotap header based on driver features */
240 	needed_headroom = ieee80211_rx_radiotap_len(local, status);
241 
242 	if (local->hw.flags & IEEE80211_HW_RX_INCLUDES_FCS)
243 		present_fcs_len = FCS_LEN;
244 
245 	/* make sure hdr->frame_control is on the linear part */
246 	if (!pskb_may_pull(origskb, 2)) {
247 		dev_kfree_skb(origskb);
248 		return NULL;
249 	}
250 
251 	if (!local->monitors) {
252 		if (should_drop_frame(origskb, present_fcs_len)) {
253 			dev_kfree_skb(origskb);
254 			return NULL;
255 		}
256 
257 		return remove_monitor_info(local, origskb);
258 	}
259 
260 	if (should_drop_frame(origskb, present_fcs_len)) {
261 		/* only need to expand headroom if necessary */
262 		skb = origskb;
263 		origskb = NULL;
264 
265 		/*
266 		 * This shouldn't trigger often because most devices have an
267 		 * RX header they pull before we get here, and that should
268 		 * be big enough for our radiotap information. We should
269 		 * probably export the length to drivers so that we can have
270 		 * them allocate enough headroom to start with.
271 		 */
272 		if (skb_headroom(skb) < needed_headroom &&
273 		    pskb_expand_head(skb, needed_headroom, 0, GFP_ATOMIC)) {
274 			dev_kfree_skb(skb);
275 			return NULL;
276 		}
277 	} else {
278 		/*
279 		 * Need to make a copy and possibly remove radiotap header
280 		 * and FCS from the original.
281 		 */
282 		skb = skb_copy_expand(origskb, needed_headroom, 0, GFP_ATOMIC);
283 
284 		origskb = remove_monitor_info(local, origskb);
285 
286 		if (!skb)
287 			return origskb;
288 	}
289 
290 	/* prepend radiotap information */
291 	ieee80211_add_rx_radiotap_header(local, skb, rate, 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 (sdata->vif.type != NL80211_IFTYPE_MONITOR)
300 			continue;
301 
302 		if (sdata->u.mntr_flags & MONITOR_FLAG_COOK_FRAMES)
303 			continue;
304 
305 		if (!ieee80211_sdata_running(sdata))
306 			continue;
307 
308 		if (prev_dev) {
309 			skb2 = skb_clone(skb, GFP_ATOMIC);
310 			if (skb2) {
311 				skb2->dev = prev_dev;
312 				netif_receive_skb(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_receive_skb(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 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
335 	int tid, seqno_idx, security_idx;
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_CTL_A_MSDU_PRESENT)
343 			status->rx_flags |= IEEE80211_RX_AMSDU;
344 
345 		seqno_idx = tid;
346 		security_idx = tid;
347 	} else {
348 		/*
349 		 * IEEE 802.11-2007, 7.1.3.4.1 ("Sequence Number field"):
350 		 *
351 		 *	Sequence numbers for management frames, QoS data
352 		 *	frames with a broadcast/multicast address in the
353 		 *	Address 1 field, and all non-QoS data frames sent
354 		 *	by QoS STAs are assigned using an additional single
355 		 *	modulo-4096 counter, [...]
356 		 *
357 		 * We also use that counter for non-QoS STAs.
358 		 */
359 		seqno_idx = NUM_RX_DATA_QUEUES;
360 		security_idx = 0;
361 		if (ieee80211_is_mgmt(hdr->frame_control))
362 			security_idx = NUM_RX_DATA_QUEUES;
363 		tid = 0;
364 	}
365 
366 	rx->seqno_idx = seqno_idx;
367 	rx->security_idx = security_idx;
368 	/* Set skb->priority to 1d tag if highest order bit of TID is not set.
369 	 * For now, set skb->priority to 0 for other cases. */
370 	rx->skb->priority = (tid > 7) ? 0 : tid;
371 }
372 
373 /**
374  * DOC: Packet alignment
375  *
376  * Drivers always need to pass packets that are aligned to two-byte boundaries
377  * to the stack.
378  *
379  * Additionally, should, if possible, align the payload data in a way that
380  * guarantees that the contained IP header is aligned to a four-byte
381  * boundary. In the case of regular frames, this simply means aligning the
382  * payload to a four-byte boundary (because either the IP header is directly
383  * contained, or IV/RFC1042 headers that have a length divisible by four are
384  * in front of it).  If the payload data is not properly aligned and the
385  * architecture doesn't support efficient unaligned operations, mac80211
386  * will align the data.
387  *
388  * With A-MSDU frames, however, the payload data address must yield two modulo
389  * four because there are 14-byte 802.3 headers within the A-MSDU frames that
390  * push the IP header further back to a multiple of four again. Thankfully, the
391  * specs were sane enough this time around to require padding each A-MSDU
392  * subframe to a length that is a multiple of four.
393  *
394  * Padding like Atheros hardware adds which is between the 802.11 header and
395  * the payload is not supported, the driver is required to move the 802.11
396  * header to be directly in front of the payload in that case.
397  */
398 static void ieee80211_verify_alignment(struct ieee80211_rx_data *rx)
399 {
400 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG
401 	WARN_ONCE((unsigned long)rx->skb->data & 1,
402 		  "unaligned packet at 0x%p\n", rx->skb->data);
403 #endif
404 }
405 
406 
407 /* rx handlers */
408 
409 static ieee80211_rx_result debug_noinline
410 ieee80211_rx_h_passive_scan(struct ieee80211_rx_data *rx)
411 {
412 	struct ieee80211_local *local = rx->local;
413 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
414 	struct sk_buff *skb = rx->skb;
415 
416 	if (likely(!(status->rx_flags & IEEE80211_RX_IN_SCAN) &&
417 		   !local->sched_scanning))
418 		return RX_CONTINUE;
419 
420 	if (test_bit(SCAN_HW_SCANNING, &local->scanning) ||
421 	    test_bit(SCAN_SW_SCANNING, &local->scanning) ||
422 	    local->sched_scanning)
423 		return ieee80211_scan_rx(rx->sdata, skb);
424 
425 	/* scanning finished during invoking of handlers */
426 	I802_DEBUG_INC(local->rx_handlers_drop_passive_scan);
427 	return RX_DROP_UNUSABLE;
428 }
429 
430 
431 static int ieee80211_is_unicast_robust_mgmt_frame(struct sk_buff *skb)
432 {
433 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
434 
435 	if (skb->len < 24 || is_multicast_ether_addr(hdr->addr1))
436 		return 0;
437 
438 	return ieee80211_is_robust_mgmt_frame(hdr);
439 }
440 
441 
442 static int ieee80211_is_multicast_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 /* Get the BIP key index from MMIE; return -1 if this is not a BIP frame */
454 static int ieee80211_get_mmie_keyidx(struct sk_buff *skb)
455 {
456 	struct ieee80211_mgmt *hdr = (struct ieee80211_mgmt *) skb->data;
457 	struct ieee80211_mmie *mmie;
458 
459 	if (skb->len < 24 + sizeof(*mmie) ||
460 	    !is_multicast_ether_addr(hdr->da))
461 		return -1;
462 
463 	if (!ieee80211_is_robust_mgmt_frame((struct ieee80211_hdr *) hdr))
464 		return -1; /* not a robust management frame */
465 
466 	mmie = (struct ieee80211_mmie *)
467 		(skb->data + skb->len - sizeof(*mmie));
468 	if (mmie->element_id != WLAN_EID_MMIE ||
469 	    mmie->length != sizeof(*mmie) - 2)
470 		return -1;
471 
472 	return le16_to_cpu(mmie->key_id);
473 }
474 
475 
476 static ieee80211_rx_result
477 ieee80211_rx_mesh_check(struct ieee80211_rx_data *rx)
478 {
479 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
480 	char *dev_addr = rx->sdata->vif.addr;
481 
482 	if (ieee80211_is_data(hdr->frame_control)) {
483 		if (is_multicast_ether_addr(hdr->addr1)) {
484 			if (ieee80211_has_tods(hdr->frame_control) ||
485 				!ieee80211_has_fromds(hdr->frame_control))
486 				return RX_DROP_MONITOR;
487 			if (memcmp(hdr->addr3, dev_addr, ETH_ALEN) == 0)
488 				return RX_DROP_MONITOR;
489 		} else {
490 			if (!ieee80211_has_a4(hdr->frame_control))
491 				return RX_DROP_MONITOR;
492 			if (memcmp(hdr->addr4, dev_addr, ETH_ALEN) == 0)
493 				return RX_DROP_MONITOR;
494 		}
495 	}
496 
497 	/* If there is not an established peer link and this is not a peer link
498 	 * establisment frame, beacon or probe, drop the frame.
499 	 */
500 
501 	if (!rx->sta || sta_plink_state(rx->sta) != NL80211_PLINK_ESTAB) {
502 		struct ieee80211_mgmt *mgmt;
503 
504 		if (!ieee80211_is_mgmt(hdr->frame_control))
505 			return RX_DROP_MONITOR;
506 
507 		if (ieee80211_is_action(hdr->frame_control)) {
508 			u8 category;
509 			mgmt = (struct ieee80211_mgmt *)hdr;
510 			category = mgmt->u.action.category;
511 			if (category != WLAN_CATEGORY_MESH_ACTION &&
512 				category != WLAN_CATEGORY_SELF_PROTECTED)
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 		    ieee80211_is_auth(hdr->frame_control))
521 			return RX_CONTINUE;
522 
523 		return RX_DROP_MONITOR;
524 
525 	}
526 
527 	return RX_CONTINUE;
528 }
529 
530 #define SEQ_MODULO 0x1000
531 #define SEQ_MASK   0xfff
532 
533 static inline int seq_less(u16 sq1, u16 sq2)
534 {
535 	return ((sq1 - sq2) & SEQ_MASK) > (SEQ_MODULO >> 1);
536 }
537 
538 static inline u16 seq_inc(u16 sq)
539 {
540 	return (sq + 1) & SEQ_MASK;
541 }
542 
543 static inline u16 seq_sub(u16 sq1, u16 sq2)
544 {
545 	return (sq1 - sq2) & SEQ_MASK;
546 }
547 
548 
549 static void ieee80211_release_reorder_frame(struct ieee80211_hw *hw,
550 					    struct tid_ampdu_rx *tid_agg_rx,
551 					    int index)
552 {
553 	struct ieee80211_local *local = hw_to_local(hw);
554 	struct sk_buff *skb = tid_agg_rx->reorder_buf[index];
555 	struct ieee80211_rx_status *status;
556 
557 	lockdep_assert_held(&tid_agg_rx->reorder_lock);
558 
559 	if (!skb)
560 		goto no_frame;
561 
562 	/* release the frame from the reorder ring buffer */
563 	tid_agg_rx->stored_mpdu_num--;
564 	tid_agg_rx->reorder_buf[index] = NULL;
565 	status = IEEE80211_SKB_RXCB(skb);
566 	status->rx_flags |= IEEE80211_RX_DEFERRED_RELEASE;
567 	skb_queue_tail(&local->rx_skb_queue, skb);
568 
569 no_frame:
570 	tid_agg_rx->head_seq_num = seq_inc(tid_agg_rx->head_seq_num);
571 }
572 
573 static void ieee80211_release_reorder_frames(struct ieee80211_hw *hw,
574 					     struct tid_ampdu_rx *tid_agg_rx,
575 					     u16 head_seq_num)
576 {
577 	int index;
578 
579 	lockdep_assert_held(&tid_agg_rx->reorder_lock);
580 
581 	while (seq_less(tid_agg_rx->head_seq_num, head_seq_num)) {
582 		index = seq_sub(tid_agg_rx->head_seq_num, tid_agg_rx->ssn) %
583 							tid_agg_rx->buf_size;
584 		ieee80211_release_reorder_frame(hw, tid_agg_rx, index);
585 	}
586 }
587 
588 /*
589  * Timeout (in jiffies) for skb's that are waiting in the RX reorder buffer. If
590  * the skb was added to the buffer longer than this time ago, the earlier
591  * frames that have not yet been received are assumed to be lost and the skb
592  * can be released for processing. This may also release other skb's from the
593  * reorder buffer if there are no additional gaps between the frames.
594  *
595  * Callers must hold tid_agg_rx->reorder_lock.
596  */
597 #define HT_RX_REORDER_BUF_TIMEOUT (HZ / 10)
598 
599 static void ieee80211_sta_reorder_release(struct ieee80211_hw *hw,
600 					  struct tid_ampdu_rx *tid_agg_rx)
601 {
602 	int index, j;
603 
604 	lockdep_assert_held(&tid_agg_rx->reorder_lock);
605 
606 	/* release the buffer until next missing frame */
607 	index = seq_sub(tid_agg_rx->head_seq_num, tid_agg_rx->ssn) %
608 						tid_agg_rx->buf_size;
609 	if (!tid_agg_rx->reorder_buf[index] &&
610 	    tid_agg_rx->stored_mpdu_num > 1) {
611 		/*
612 		 * No buffers ready to be released, but check whether any
613 		 * frames in the reorder buffer have timed out.
614 		 */
615 		int skipped = 1;
616 		for (j = (index + 1) % tid_agg_rx->buf_size; j != index;
617 		     j = (j + 1) % tid_agg_rx->buf_size) {
618 			if (!tid_agg_rx->reorder_buf[j]) {
619 				skipped++;
620 				continue;
621 			}
622 			if (skipped &&
623 			    !time_after(jiffies, tid_agg_rx->reorder_time[j] +
624 					HT_RX_REORDER_BUF_TIMEOUT))
625 				goto set_release_timer;
626 
627 #ifdef CONFIG_MAC80211_HT_DEBUG
628 			if (net_ratelimit())
629 				wiphy_debug(hw->wiphy,
630 					    "release an RX reorder frame due to timeout on earlier frames\n");
631 #endif
632 			ieee80211_release_reorder_frame(hw, tid_agg_rx, j);
633 
634 			/*
635 			 * Increment the head seq# also for the skipped slots.
636 			 */
637 			tid_agg_rx->head_seq_num =
638 				(tid_agg_rx->head_seq_num + skipped) & SEQ_MASK;
639 			skipped = 0;
640 		}
641 	} else while (tid_agg_rx->reorder_buf[index]) {
642 		ieee80211_release_reorder_frame(hw, tid_agg_rx, index);
643 		index =	seq_sub(tid_agg_rx->head_seq_num, tid_agg_rx->ssn) %
644 							tid_agg_rx->buf_size;
645 	}
646 
647 	if (tid_agg_rx->stored_mpdu_num) {
648 		j = index = seq_sub(tid_agg_rx->head_seq_num,
649 				    tid_agg_rx->ssn) % tid_agg_rx->buf_size;
650 
651 		for (; j != (index - 1) % tid_agg_rx->buf_size;
652 		     j = (j + 1) % tid_agg_rx->buf_size) {
653 			if (tid_agg_rx->reorder_buf[j])
654 				break;
655 		}
656 
657  set_release_timer:
658 
659 		mod_timer(&tid_agg_rx->reorder_timer,
660 			  tid_agg_rx->reorder_time[j] + 1 +
661 			  HT_RX_REORDER_BUF_TIMEOUT);
662 	} else {
663 		del_timer(&tid_agg_rx->reorder_timer);
664 	}
665 }
666 
667 /*
668  * As this function belongs to the RX path it must be under
669  * rcu_read_lock protection. It returns false if the frame
670  * can be processed immediately, true if it was consumed.
671  */
672 static bool ieee80211_sta_manage_reorder_buf(struct ieee80211_hw *hw,
673 					     struct tid_ampdu_rx *tid_agg_rx,
674 					     struct sk_buff *skb)
675 {
676 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
677 	u16 sc = le16_to_cpu(hdr->seq_ctrl);
678 	u16 mpdu_seq_num = (sc & IEEE80211_SCTL_SEQ) >> 4;
679 	u16 head_seq_num, buf_size;
680 	int index;
681 	bool ret = true;
682 
683 	spin_lock(&tid_agg_rx->reorder_lock);
684 
685 	buf_size = tid_agg_rx->buf_size;
686 	head_seq_num = tid_agg_rx->head_seq_num;
687 
688 	/* frame with out of date sequence number */
689 	if (seq_less(mpdu_seq_num, head_seq_num)) {
690 		dev_kfree_skb(skb);
691 		goto out;
692 	}
693 
694 	/*
695 	 * If frame the sequence number exceeds our buffering window
696 	 * size release some previous frames to make room for this one.
697 	 */
698 	if (!seq_less(mpdu_seq_num, head_seq_num + buf_size)) {
699 		head_seq_num = seq_inc(seq_sub(mpdu_seq_num, buf_size));
700 		/* release stored frames up to new head to stack */
701 		ieee80211_release_reorder_frames(hw, tid_agg_rx, head_seq_num);
702 	}
703 
704 	/* Now the new frame is always in the range of the reordering buffer */
705 
706 	index = seq_sub(mpdu_seq_num, tid_agg_rx->ssn) % tid_agg_rx->buf_size;
707 
708 	/* check if we already stored this frame */
709 	if (tid_agg_rx->reorder_buf[index]) {
710 		dev_kfree_skb(skb);
711 		goto out;
712 	}
713 
714 	/*
715 	 * If the current MPDU is in the right order and nothing else
716 	 * is stored we can process it directly, no need to buffer it.
717 	 * If it is first but there's something stored, we may be able
718 	 * to release frames after this one.
719 	 */
720 	if (mpdu_seq_num == tid_agg_rx->head_seq_num &&
721 	    tid_agg_rx->stored_mpdu_num == 0) {
722 		tid_agg_rx->head_seq_num = seq_inc(tid_agg_rx->head_seq_num);
723 		ret = false;
724 		goto out;
725 	}
726 
727 	/* put the frame in the reordering buffer */
728 	tid_agg_rx->reorder_buf[index] = skb;
729 	tid_agg_rx->reorder_time[index] = jiffies;
730 	tid_agg_rx->stored_mpdu_num++;
731 	ieee80211_sta_reorder_release(hw, tid_agg_rx);
732 
733  out:
734 	spin_unlock(&tid_agg_rx->reorder_lock);
735 	return ret;
736 }
737 
738 /*
739  * Reorder MPDUs from A-MPDUs, keeping them on a buffer. Returns
740  * true if the MPDU was buffered, false if it should be processed.
741  */
742 static void ieee80211_rx_reorder_ampdu(struct ieee80211_rx_data *rx)
743 {
744 	struct sk_buff *skb = rx->skb;
745 	struct ieee80211_local *local = rx->local;
746 	struct ieee80211_hw *hw = &local->hw;
747 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
748 	struct sta_info *sta = rx->sta;
749 	struct tid_ampdu_rx *tid_agg_rx;
750 	u16 sc;
751 	int tid;
752 
753 	if (!ieee80211_is_data_qos(hdr->frame_control))
754 		goto dont_reorder;
755 
756 	/*
757 	 * filter the QoS data rx stream according to
758 	 * STA/TID and check if this STA/TID is on aggregation
759 	 */
760 
761 	if (!sta)
762 		goto dont_reorder;
763 
764 	tid = *ieee80211_get_qos_ctl(hdr) & IEEE80211_QOS_CTL_TID_MASK;
765 
766 	tid_agg_rx = rcu_dereference(sta->ampdu_mlme.tid_rx[tid]);
767 	if (!tid_agg_rx)
768 		goto dont_reorder;
769 
770 	/* qos null data frames are excluded */
771 	if (unlikely(hdr->frame_control & cpu_to_le16(IEEE80211_STYPE_NULLFUNC)))
772 		goto dont_reorder;
773 
774 	/* new, potentially un-ordered, ampdu frame - process it */
775 
776 	/* reset session timer */
777 	if (tid_agg_rx->timeout)
778 		mod_timer(&tid_agg_rx->session_timer,
779 			  TU_TO_EXP_TIME(tid_agg_rx->timeout));
780 
781 	/* if this mpdu is fragmented - terminate rx aggregation session */
782 	sc = le16_to_cpu(hdr->seq_ctrl);
783 	if (sc & IEEE80211_SCTL_FRAG) {
784 		skb->pkt_type = IEEE80211_SDATA_QUEUE_TYPE_FRAME;
785 		skb_queue_tail(&rx->sdata->skb_queue, skb);
786 		ieee80211_queue_work(&local->hw, &rx->sdata->work);
787 		return;
788 	}
789 
790 	/*
791 	 * No locking needed -- we will only ever process one
792 	 * RX packet at a time, and thus own tid_agg_rx. All
793 	 * other code manipulating it needs to (and does) make
794 	 * sure that we cannot get to it any more before doing
795 	 * anything with it.
796 	 */
797 	if (ieee80211_sta_manage_reorder_buf(hw, tid_agg_rx, skb))
798 		return;
799 
800  dont_reorder:
801 	skb_queue_tail(&local->rx_skb_queue, skb);
802 }
803 
804 static ieee80211_rx_result debug_noinline
805 ieee80211_rx_h_check(struct ieee80211_rx_data *rx)
806 {
807 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
808 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
809 
810 	/* Drop duplicate 802.11 retransmissions (IEEE 802.11 Chap. 9.2.9) */
811 	if (rx->sta && !is_multicast_ether_addr(hdr->addr1)) {
812 		if (unlikely(ieee80211_has_retry(hdr->frame_control) &&
813 			     rx->sta->last_seq_ctrl[rx->seqno_idx] ==
814 			     hdr->seq_ctrl)) {
815 			if (status->rx_flags & IEEE80211_RX_RA_MATCH) {
816 				rx->local->dot11FrameDuplicateCount++;
817 				rx->sta->num_duplicates++;
818 			}
819 			return RX_DROP_UNUSABLE;
820 		} else
821 			rx->sta->last_seq_ctrl[rx->seqno_idx] = hdr->seq_ctrl;
822 	}
823 
824 	if (unlikely(rx->skb->len < 16)) {
825 		I802_DEBUG_INC(rx->local->rx_handlers_drop_short);
826 		return RX_DROP_MONITOR;
827 	}
828 
829 	/* Drop disallowed frame classes based on STA auth/assoc state;
830 	 * IEEE 802.11, Chap 5.5.
831 	 *
832 	 * mac80211 filters only based on association state, i.e. it drops
833 	 * Class 3 frames from not associated stations. hostapd sends
834 	 * deauth/disassoc frames when needed. In addition, hostapd is
835 	 * responsible for filtering on both auth and assoc states.
836 	 */
837 
838 	if (ieee80211_vif_is_mesh(&rx->sdata->vif))
839 		return ieee80211_rx_mesh_check(rx);
840 
841 	if (unlikely((ieee80211_is_data(hdr->frame_control) ||
842 		      ieee80211_is_pspoll(hdr->frame_control)) &&
843 		     rx->sdata->vif.type != NL80211_IFTYPE_ADHOC &&
844 		     rx->sdata->vif.type != NL80211_IFTYPE_WDS &&
845 		     (!rx->sta || !test_sta_flag(rx->sta, WLAN_STA_ASSOC)))) {
846 		if (rx->sta && rx->sta->dummy &&
847 		    ieee80211_is_data_present(hdr->frame_control)) {
848 			u16 ethertype;
849 			u8 *payload;
850 
851 			payload = rx->skb->data +
852 				ieee80211_hdrlen(hdr->frame_control);
853 			ethertype = (payload[6] << 8) | payload[7];
854 			if (cpu_to_be16(ethertype) ==
855 			    rx->sdata->control_port_protocol)
856 				return RX_CONTINUE;
857 		}
858 		return RX_DROP_MONITOR;
859 	}
860 
861 	return RX_CONTINUE;
862 }
863 
864 
865 static ieee80211_rx_result debug_noinline
866 ieee80211_rx_h_decrypt(struct ieee80211_rx_data *rx)
867 {
868 	struct sk_buff *skb = rx->skb;
869 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
870 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
871 	int keyidx;
872 	int hdrlen;
873 	ieee80211_rx_result result = RX_DROP_UNUSABLE;
874 	struct ieee80211_key *sta_ptk = NULL;
875 	int mmie_keyidx = -1;
876 	__le16 fc;
877 
878 	/*
879 	 * Key selection 101
880 	 *
881 	 * There are four types of keys:
882 	 *  - GTK (group keys)
883 	 *  - IGTK (group keys for management frames)
884 	 *  - PTK (pairwise keys)
885 	 *  - STK (station-to-station pairwise keys)
886 	 *
887 	 * When selecting a key, we have to distinguish between multicast
888 	 * (including broadcast) and unicast frames, the latter can only
889 	 * use PTKs and STKs while the former always use GTKs and IGTKs.
890 	 * Unless, of course, actual WEP keys ("pre-RSNA") are used, then
891 	 * unicast frames can also use key indices like GTKs. Hence, if we
892 	 * don't have a PTK/STK we check the key index for a WEP key.
893 	 *
894 	 * Note that in a regular BSS, multicast frames are sent by the
895 	 * AP only, associated stations unicast the frame to the AP first
896 	 * which then multicasts it on their behalf.
897 	 *
898 	 * There is also a slight problem in IBSS mode: GTKs are negotiated
899 	 * with each station, that is something we don't currently handle.
900 	 * The spec seems to expect that one negotiates the same key with
901 	 * every station but there's no such requirement; VLANs could be
902 	 * possible.
903 	 */
904 
905 	/*
906 	 * No point in finding a key and decrypting if the frame is neither
907 	 * addressed to us nor a multicast frame.
908 	 */
909 	if (!(status->rx_flags & IEEE80211_RX_RA_MATCH))
910 		return RX_CONTINUE;
911 
912 	/* start without a key */
913 	rx->key = NULL;
914 
915 	if (rx->sta)
916 		sta_ptk = rcu_dereference(rx->sta->ptk);
917 
918 	fc = hdr->frame_control;
919 
920 	if (!ieee80211_has_protected(fc))
921 		mmie_keyidx = ieee80211_get_mmie_keyidx(rx->skb);
922 
923 	if (!is_multicast_ether_addr(hdr->addr1) && sta_ptk) {
924 		rx->key = sta_ptk;
925 		if ((status->flag & RX_FLAG_DECRYPTED) &&
926 		    (status->flag & RX_FLAG_IV_STRIPPED))
927 			return RX_CONTINUE;
928 		/* Skip decryption if the frame is not protected. */
929 		if (!ieee80211_has_protected(fc))
930 			return RX_CONTINUE;
931 	} else if (mmie_keyidx >= 0) {
932 		/* Broadcast/multicast robust management frame / BIP */
933 		if ((status->flag & RX_FLAG_DECRYPTED) &&
934 		    (status->flag & RX_FLAG_IV_STRIPPED))
935 			return RX_CONTINUE;
936 
937 		if (mmie_keyidx < NUM_DEFAULT_KEYS ||
938 		    mmie_keyidx >= NUM_DEFAULT_KEYS + NUM_DEFAULT_MGMT_KEYS)
939 			return RX_DROP_MONITOR; /* unexpected BIP keyidx */
940 		if (rx->sta)
941 			rx->key = rcu_dereference(rx->sta->gtk[mmie_keyidx]);
942 		if (!rx->key)
943 			rx->key = rcu_dereference(rx->sdata->keys[mmie_keyidx]);
944 	} else if (!ieee80211_has_protected(fc)) {
945 		/*
946 		 * The frame was not protected, so skip decryption. However, we
947 		 * need to set rx->key if there is a key that could have been
948 		 * used so that the frame may be dropped if encryption would
949 		 * have been expected.
950 		 */
951 		struct ieee80211_key *key = NULL;
952 		struct ieee80211_sub_if_data *sdata = rx->sdata;
953 		int i;
954 
955 		if (ieee80211_is_mgmt(fc) &&
956 		    is_multicast_ether_addr(hdr->addr1) &&
957 		    (key = rcu_dereference(rx->sdata->default_mgmt_key)))
958 			rx->key = key;
959 		else {
960 			if (rx->sta) {
961 				for (i = 0; i < NUM_DEFAULT_KEYS; i++) {
962 					key = rcu_dereference(rx->sta->gtk[i]);
963 					if (key)
964 						break;
965 				}
966 			}
967 			if (!key) {
968 				for (i = 0; i < NUM_DEFAULT_KEYS; i++) {
969 					key = rcu_dereference(sdata->keys[i]);
970 					if (key)
971 						break;
972 				}
973 			}
974 			if (key)
975 				rx->key = key;
976 		}
977 		return RX_CONTINUE;
978 	} else {
979 		u8 keyid;
980 		/*
981 		 * The device doesn't give us the IV so we won't be
982 		 * able to look up the key. That's ok though, we
983 		 * don't need to decrypt the frame, we just won't
984 		 * be able to keep statistics accurate.
985 		 * Except for key threshold notifications, should
986 		 * we somehow allow the driver to tell us which key
987 		 * the hardware used if this flag is set?
988 		 */
989 		if ((status->flag & RX_FLAG_DECRYPTED) &&
990 		    (status->flag & RX_FLAG_IV_STRIPPED))
991 			return RX_CONTINUE;
992 
993 		hdrlen = ieee80211_hdrlen(fc);
994 
995 		if (rx->skb->len < 8 + hdrlen)
996 			return RX_DROP_UNUSABLE; /* TODO: count this? */
997 
998 		/*
999 		 * no need to call ieee80211_wep_get_keyidx,
1000 		 * it verifies a bunch of things we've done already
1001 		 */
1002 		skb_copy_bits(rx->skb, hdrlen + 3, &keyid, 1);
1003 		keyidx = keyid >> 6;
1004 
1005 		/* check per-station GTK first, if multicast packet */
1006 		if (is_multicast_ether_addr(hdr->addr1) && rx->sta)
1007 			rx->key = rcu_dereference(rx->sta->gtk[keyidx]);
1008 
1009 		/* if not found, try default key */
1010 		if (!rx->key) {
1011 			rx->key = rcu_dereference(rx->sdata->keys[keyidx]);
1012 
1013 			/*
1014 			 * RSNA-protected unicast frames should always be
1015 			 * sent with pairwise or station-to-station keys,
1016 			 * but for WEP we allow using a key index as well.
1017 			 */
1018 			if (rx->key &&
1019 			    rx->key->conf.cipher != WLAN_CIPHER_SUITE_WEP40 &&
1020 			    rx->key->conf.cipher != WLAN_CIPHER_SUITE_WEP104 &&
1021 			    !is_multicast_ether_addr(hdr->addr1))
1022 				rx->key = NULL;
1023 		}
1024 	}
1025 
1026 	if (rx->key) {
1027 		if (unlikely(rx->key->flags & KEY_FLAG_TAINTED))
1028 			return RX_DROP_MONITOR;
1029 
1030 		rx->key->tx_rx_count++;
1031 		/* TODO: add threshold stuff again */
1032 	} else {
1033 		return RX_DROP_MONITOR;
1034 	}
1035 
1036 	if (skb_linearize(rx->skb))
1037 		return RX_DROP_UNUSABLE;
1038 	/* the hdr variable is invalid now! */
1039 
1040 	switch (rx->key->conf.cipher) {
1041 	case WLAN_CIPHER_SUITE_WEP40:
1042 	case WLAN_CIPHER_SUITE_WEP104:
1043 		/* Check for weak IVs if possible */
1044 		if (rx->sta && ieee80211_is_data(fc) &&
1045 		    (!(status->flag & RX_FLAG_IV_STRIPPED) ||
1046 		     !(status->flag & RX_FLAG_DECRYPTED)) &&
1047 		    ieee80211_wep_is_weak_iv(rx->skb, rx->key))
1048 			rx->sta->wep_weak_iv_count++;
1049 
1050 		result = ieee80211_crypto_wep_decrypt(rx);
1051 		break;
1052 	case WLAN_CIPHER_SUITE_TKIP:
1053 		result = ieee80211_crypto_tkip_decrypt(rx);
1054 		break;
1055 	case WLAN_CIPHER_SUITE_CCMP:
1056 		result = ieee80211_crypto_ccmp_decrypt(rx);
1057 		break;
1058 	case WLAN_CIPHER_SUITE_AES_CMAC:
1059 		result = ieee80211_crypto_aes_cmac_decrypt(rx);
1060 		break;
1061 	default:
1062 		/*
1063 		 * We can reach here only with HW-only algorithms
1064 		 * but why didn't it decrypt the frame?!
1065 		 */
1066 		return RX_DROP_UNUSABLE;
1067 	}
1068 
1069 	/* either the frame has been decrypted or will be dropped */
1070 	status->flag |= RX_FLAG_DECRYPTED;
1071 
1072 	return result;
1073 }
1074 
1075 static ieee80211_rx_result debug_noinline
1076 ieee80211_rx_h_check_more_data(struct ieee80211_rx_data *rx)
1077 {
1078 	struct ieee80211_local *local;
1079 	struct ieee80211_hdr *hdr;
1080 	struct sk_buff *skb;
1081 
1082 	local = rx->local;
1083 	skb = rx->skb;
1084 	hdr = (struct ieee80211_hdr *) skb->data;
1085 
1086 	if (!local->pspolling)
1087 		return RX_CONTINUE;
1088 
1089 	if (!ieee80211_has_fromds(hdr->frame_control))
1090 		/* this is not from AP */
1091 		return RX_CONTINUE;
1092 
1093 	if (!ieee80211_is_data(hdr->frame_control))
1094 		return RX_CONTINUE;
1095 
1096 	if (!ieee80211_has_moredata(hdr->frame_control)) {
1097 		/* AP has no more frames buffered for us */
1098 		local->pspolling = false;
1099 		return RX_CONTINUE;
1100 	}
1101 
1102 	/* more data bit is set, let's request a new frame from the AP */
1103 	ieee80211_send_pspoll(local, rx->sdata);
1104 
1105 	return RX_CONTINUE;
1106 }
1107 
1108 static void ap_sta_ps_start(struct sta_info *sta)
1109 {
1110 	struct ieee80211_sub_if_data *sdata = sta->sdata;
1111 	struct ieee80211_local *local = sdata->local;
1112 
1113 	atomic_inc(&sdata->bss->num_sta_ps);
1114 	set_sta_flag(sta, WLAN_STA_PS_STA);
1115 	if (!(local->hw.flags & IEEE80211_HW_AP_LINK_PS))
1116 		drv_sta_notify(local, sdata, STA_NOTIFY_SLEEP, &sta->sta);
1117 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
1118 	printk(KERN_DEBUG "%s: STA %pM aid %d enters power save mode\n",
1119 	       sdata->name, sta->sta.addr, sta->sta.aid);
1120 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
1121 }
1122 
1123 static void ap_sta_ps_end(struct sta_info *sta)
1124 {
1125 	struct ieee80211_sub_if_data *sdata = sta->sdata;
1126 
1127 	atomic_dec(&sdata->bss->num_sta_ps);
1128 
1129 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
1130 	printk(KERN_DEBUG "%s: STA %pM aid %d exits power save mode\n",
1131 	       sdata->name, sta->sta.addr, sta->sta.aid);
1132 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
1133 
1134 	if (test_sta_flag(sta, WLAN_STA_PS_DRIVER)) {
1135 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
1136 		printk(KERN_DEBUG "%s: STA %pM aid %d driver-ps-blocked\n",
1137 		       sdata->name, sta->sta.addr, sta->sta.aid);
1138 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
1139 		return;
1140 	}
1141 
1142 	ieee80211_sta_ps_deliver_wakeup(sta);
1143 }
1144 
1145 int ieee80211_sta_ps_transition(struct ieee80211_sta *sta, bool start)
1146 {
1147 	struct sta_info *sta_inf = container_of(sta, struct sta_info, sta);
1148 	bool in_ps;
1149 
1150 	WARN_ON(!(sta_inf->local->hw.flags & IEEE80211_HW_AP_LINK_PS));
1151 
1152 	/* Don't let the same PS state be set twice */
1153 	in_ps = test_sta_flag(sta_inf, WLAN_STA_PS_STA);
1154 	if ((start && in_ps) || (!start && !in_ps))
1155 		return -EINVAL;
1156 
1157 	if (start)
1158 		ap_sta_ps_start(sta_inf);
1159 	else
1160 		ap_sta_ps_end(sta_inf);
1161 
1162 	return 0;
1163 }
1164 EXPORT_SYMBOL(ieee80211_sta_ps_transition);
1165 
1166 static ieee80211_rx_result debug_noinline
1167 ieee80211_rx_h_uapsd_and_pspoll(struct ieee80211_rx_data *rx)
1168 {
1169 	struct ieee80211_sub_if_data *sdata = rx->sdata;
1170 	struct ieee80211_hdr *hdr = (void *)rx->skb->data;
1171 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
1172 	int tid, ac;
1173 
1174 	if (!rx->sta || !(status->rx_flags & IEEE80211_RX_RA_MATCH))
1175 		return RX_CONTINUE;
1176 
1177 	if (sdata->vif.type != NL80211_IFTYPE_AP &&
1178 	    sdata->vif.type != NL80211_IFTYPE_AP_VLAN)
1179 		return RX_CONTINUE;
1180 
1181 	/*
1182 	 * The device handles station powersave, so don't do anything about
1183 	 * uAPSD and PS-Poll frames (the latter shouldn't even come up from
1184 	 * it to mac80211 since they're handled.)
1185 	 */
1186 	if (sdata->local->hw.flags & IEEE80211_HW_AP_LINK_PS)
1187 		return RX_CONTINUE;
1188 
1189 	/*
1190 	 * Don't do anything if the station isn't already asleep. In
1191 	 * the uAPSD case, the station will probably be marked asleep,
1192 	 * in the PS-Poll case the station must be confused ...
1193 	 */
1194 	if (!test_sta_flag(rx->sta, WLAN_STA_PS_STA))
1195 		return RX_CONTINUE;
1196 
1197 	if (unlikely(ieee80211_is_pspoll(hdr->frame_control))) {
1198 		if (!test_sta_flag(rx->sta, WLAN_STA_SP)) {
1199 			if (!test_sta_flag(rx->sta, WLAN_STA_PS_DRIVER))
1200 				ieee80211_sta_ps_deliver_poll_response(rx->sta);
1201 			else
1202 				set_sta_flag(rx->sta, WLAN_STA_PSPOLL);
1203 		}
1204 
1205 		/* Free PS Poll skb here instead of returning RX_DROP that would
1206 		 * count as an dropped frame. */
1207 		dev_kfree_skb(rx->skb);
1208 
1209 		return RX_QUEUED;
1210 	} else if (!ieee80211_has_morefrags(hdr->frame_control) &&
1211 		   !(status->rx_flags & IEEE80211_RX_DEFERRED_RELEASE) &&
1212 		   ieee80211_has_pm(hdr->frame_control) &&
1213 		   (ieee80211_is_data_qos(hdr->frame_control) ||
1214 		    ieee80211_is_qos_nullfunc(hdr->frame_control))) {
1215 		tid = *ieee80211_get_qos_ctl(hdr) & IEEE80211_QOS_CTL_TID_MASK;
1216 		ac = ieee802_1d_to_ac[tid & 7];
1217 
1218 		/*
1219 		 * If this AC is not trigger-enabled do nothing.
1220 		 *
1221 		 * NB: This could/should check a separate bitmap of trigger-
1222 		 * enabled queues, but for now we only implement uAPSD w/o
1223 		 * TSPEC changes to the ACs, so they're always the same.
1224 		 */
1225 		if (!(rx->sta->sta.uapsd_queues & BIT(ac)))
1226 			return RX_CONTINUE;
1227 
1228 		/* if we are in a service period, do nothing */
1229 		if (test_sta_flag(rx->sta, WLAN_STA_SP))
1230 			return RX_CONTINUE;
1231 
1232 		if (!test_sta_flag(rx->sta, WLAN_STA_PS_DRIVER))
1233 			ieee80211_sta_ps_deliver_uapsd(rx->sta);
1234 		else
1235 			set_sta_flag(rx->sta, WLAN_STA_UAPSD);
1236 	}
1237 
1238 	return RX_CONTINUE;
1239 }
1240 
1241 static ieee80211_rx_result debug_noinline
1242 ieee80211_rx_h_sta_process(struct ieee80211_rx_data *rx)
1243 {
1244 	struct sta_info *sta = rx->sta;
1245 	struct sk_buff *skb = rx->skb;
1246 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
1247 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
1248 
1249 	if (!sta)
1250 		return RX_CONTINUE;
1251 
1252 	/*
1253 	 * Update last_rx only for IBSS packets which are for the current
1254 	 * BSSID to avoid keeping the current IBSS network alive in cases
1255 	 * where other STAs start using different BSSID.
1256 	 */
1257 	if (rx->sdata->vif.type == NL80211_IFTYPE_ADHOC) {
1258 		u8 *bssid = ieee80211_get_bssid(hdr, rx->skb->len,
1259 						NL80211_IFTYPE_ADHOC);
1260 		if (compare_ether_addr(bssid, rx->sdata->u.ibss.bssid) == 0) {
1261 			sta->last_rx = jiffies;
1262 			if (ieee80211_is_data(hdr->frame_control)) {
1263 				sta->last_rx_rate_idx = status->rate_idx;
1264 				sta->last_rx_rate_flag = status->flag;
1265 			}
1266 		}
1267 	} else if (!is_multicast_ether_addr(hdr->addr1)) {
1268 		/*
1269 		 * Mesh beacons will update last_rx when if they are found to
1270 		 * match the current local configuration when processed.
1271 		 */
1272 		sta->last_rx = jiffies;
1273 		if (ieee80211_is_data(hdr->frame_control)) {
1274 			sta->last_rx_rate_idx = status->rate_idx;
1275 			sta->last_rx_rate_flag = status->flag;
1276 		}
1277 	}
1278 
1279 	if (!(status->rx_flags & IEEE80211_RX_RA_MATCH))
1280 		return RX_CONTINUE;
1281 
1282 	if (rx->sdata->vif.type == NL80211_IFTYPE_STATION)
1283 		ieee80211_sta_rx_notify(rx->sdata, hdr);
1284 
1285 	sta->rx_fragments++;
1286 	sta->rx_bytes += rx->skb->len;
1287 	sta->last_signal = status->signal;
1288 	ewma_add(&sta->avg_signal, -status->signal);
1289 
1290 	/*
1291 	 * Change STA power saving mode only at the end of a frame
1292 	 * exchange sequence.
1293 	 */
1294 	if (!(sta->local->hw.flags & IEEE80211_HW_AP_LINK_PS) &&
1295 	    !ieee80211_has_morefrags(hdr->frame_control) &&
1296 	    !(status->rx_flags & IEEE80211_RX_DEFERRED_RELEASE) &&
1297 	    (rx->sdata->vif.type == NL80211_IFTYPE_AP ||
1298 	     rx->sdata->vif.type == NL80211_IFTYPE_AP_VLAN)) {
1299 		if (test_sta_flag(sta, WLAN_STA_PS_STA)) {
1300 			/*
1301 			 * Ignore doze->wake transitions that are
1302 			 * indicated by non-data frames, the standard
1303 			 * is unclear here, but for example going to
1304 			 * PS mode and then scanning would cause a
1305 			 * doze->wake transition for the probe request,
1306 			 * and that is clearly undesirable.
1307 			 */
1308 			if (ieee80211_is_data(hdr->frame_control) &&
1309 			    !ieee80211_has_pm(hdr->frame_control))
1310 				ap_sta_ps_end(sta);
1311 		} else {
1312 			if (ieee80211_has_pm(hdr->frame_control))
1313 				ap_sta_ps_start(sta);
1314 		}
1315 	}
1316 
1317 	/*
1318 	 * Drop (qos-)data::nullfunc frames silently, since they
1319 	 * are used only to control station power saving mode.
1320 	 */
1321 	if (ieee80211_is_nullfunc(hdr->frame_control) ||
1322 	    ieee80211_is_qos_nullfunc(hdr->frame_control)) {
1323 		I802_DEBUG_INC(rx->local->rx_handlers_drop_nullfunc);
1324 
1325 		/*
1326 		 * If we receive a 4-addr nullfunc frame from a STA
1327 		 * that was not moved to a 4-addr STA vlan yet, drop
1328 		 * the frame to the monitor interface, to make sure
1329 		 * that hostapd sees it
1330 		 */
1331 		if (ieee80211_has_a4(hdr->frame_control) &&
1332 		    (rx->sdata->vif.type == NL80211_IFTYPE_AP ||
1333 		     (rx->sdata->vif.type == NL80211_IFTYPE_AP_VLAN &&
1334 		      !rx->sdata->u.vlan.sta)))
1335 			return RX_DROP_MONITOR;
1336 		/*
1337 		 * Update counter and free packet here to avoid
1338 		 * counting this as a dropped packed.
1339 		 */
1340 		sta->rx_packets++;
1341 		dev_kfree_skb(rx->skb);
1342 		return RX_QUEUED;
1343 	}
1344 
1345 	return RX_CONTINUE;
1346 } /* ieee80211_rx_h_sta_process */
1347 
1348 static inline struct ieee80211_fragment_entry *
1349 ieee80211_reassemble_add(struct ieee80211_sub_if_data *sdata,
1350 			 unsigned int frag, unsigned int seq, int rx_queue,
1351 			 struct sk_buff **skb)
1352 {
1353 	struct ieee80211_fragment_entry *entry;
1354 	int idx;
1355 
1356 	idx = sdata->fragment_next;
1357 	entry = &sdata->fragments[sdata->fragment_next++];
1358 	if (sdata->fragment_next >= IEEE80211_FRAGMENT_MAX)
1359 		sdata->fragment_next = 0;
1360 
1361 	if (!skb_queue_empty(&entry->skb_list)) {
1362 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG
1363 		struct ieee80211_hdr *hdr =
1364 			(struct ieee80211_hdr *) entry->skb_list.next->data;
1365 		printk(KERN_DEBUG "%s: RX reassembly removed oldest "
1366 		       "fragment entry (idx=%d age=%lu seq=%d last_frag=%d "
1367 		       "addr1=%pM addr2=%pM\n",
1368 		       sdata->name, idx,
1369 		       jiffies - entry->first_frag_time, entry->seq,
1370 		       entry->last_frag, hdr->addr1, hdr->addr2);
1371 #endif
1372 		__skb_queue_purge(&entry->skb_list);
1373 	}
1374 
1375 	__skb_queue_tail(&entry->skb_list, *skb); /* no need for locking */
1376 	*skb = NULL;
1377 	entry->first_frag_time = jiffies;
1378 	entry->seq = seq;
1379 	entry->rx_queue = rx_queue;
1380 	entry->last_frag = frag;
1381 	entry->ccmp = 0;
1382 	entry->extra_len = 0;
1383 
1384 	return entry;
1385 }
1386 
1387 static inline struct ieee80211_fragment_entry *
1388 ieee80211_reassemble_find(struct ieee80211_sub_if_data *sdata,
1389 			  unsigned int frag, unsigned int seq,
1390 			  int rx_queue, struct ieee80211_hdr *hdr)
1391 {
1392 	struct ieee80211_fragment_entry *entry;
1393 	int i, idx;
1394 
1395 	idx = sdata->fragment_next;
1396 	for (i = 0; i < IEEE80211_FRAGMENT_MAX; i++) {
1397 		struct ieee80211_hdr *f_hdr;
1398 
1399 		idx--;
1400 		if (idx < 0)
1401 			idx = IEEE80211_FRAGMENT_MAX - 1;
1402 
1403 		entry = &sdata->fragments[idx];
1404 		if (skb_queue_empty(&entry->skb_list) || entry->seq != seq ||
1405 		    entry->rx_queue != rx_queue ||
1406 		    entry->last_frag + 1 != frag)
1407 			continue;
1408 
1409 		f_hdr = (struct ieee80211_hdr *)entry->skb_list.next->data;
1410 
1411 		/*
1412 		 * Check ftype and addresses are equal, else check next fragment
1413 		 */
1414 		if (((hdr->frame_control ^ f_hdr->frame_control) &
1415 		     cpu_to_le16(IEEE80211_FCTL_FTYPE)) ||
1416 		    compare_ether_addr(hdr->addr1, f_hdr->addr1) != 0 ||
1417 		    compare_ether_addr(hdr->addr2, f_hdr->addr2) != 0)
1418 			continue;
1419 
1420 		if (time_after(jiffies, entry->first_frag_time + 2 * HZ)) {
1421 			__skb_queue_purge(&entry->skb_list);
1422 			continue;
1423 		}
1424 		return entry;
1425 	}
1426 
1427 	return NULL;
1428 }
1429 
1430 static ieee80211_rx_result debug_noinline
1431 ieee80211_rx_h_defragment(struct ieee80211_rx_data *rx)
1432 {
1433 	struct ieee80211_hdr *hdr;
1434 	u16 sc;
1435 	__le16 fc;
1436 	unsigned int frag, seq;
1437 	struct ieee80211_fragment_entry *entry;
1438 	struct sk_buff *skb;
1439 	struct ieee80211_rx_status *status;
1440 
1441 	hdr = (struct ieee80211_hdr *)rx->skb->data;
1442 	fc = hdr->frame_control;
1443 	sc = le16_to_cpu(hdr->seq_ctrl);
1444 	frag = sc & IEEE80211_SCTL_FRAG;
1445 
1446 	if (likely((!ieee80211_has_morefrags(fc) && frag == 0) ||
1447 		   (rx->skb)->len < 24 ||
1448 		   is_multicast_ether_addr(hdr->addr1))) {
1449 		/* not fragmented */
1450 		goto out;
1451 	}
1452 	I802_DEBUG_INC(rx->local->rx_handlers_fragments);
1453 
1454 	if (skb_linearize(rx->skb))
1455 		return RX_DROP_UNUSABLE;
1456 
1457 	/*
1458 	 *  skb_linearize() might change the skb->data and
1459 	 *  previously cached variables (in this case, hdr) need to
1460 	 *  be refreshed with the new data.
1461 	 */
1462 	hdr = (struct ieee80211_hdr *)rx->skb->data;
1463 	seq = (sc & IEEE80211_SCTL_SEQ) >> 4;
1464 
1465 	if (frag == 0) {
1466 		/* This is the first fragment of a new frame. */
1467 		entry = ieee80211_reassemble_add(rx->sdata, frag, seq,
1468 						 rx->seqno_idx, &(rx->skb));
1469 		if (rx->key && rx->key->conf.cipher == WLAN_CIPHER_SUITE_CCMP &&
1470 		    ieee80211_has_protected(fc)) {
1471 			int queue = rx->security_idx;
1472 			/* Store CCMP PN so that we can verify that the next
1473 			 * fragment has a sequential PN value. */
1474 			entry->ccmp = 1;
1475 			memcpy(entry->last_pn,
1476 			       rx->key->u.ccmp.rx_pn[queue],
1477 			       CCMP_PN_LEN);
1478 		}
1479 		return RX_QUEUED;
1480 	}
1481 
1482 	/* This is a fragment for a frame that should already be pending in
1483 	 * fragment cache. Add this fragment to the end of the pending entry.
1484 	 */
1485 	entry = ieee80211_reassemble_find(rx->sdata, frag, seq,
1486 					  rx->seqno_idx, hdr);
1487 	if (!entry) {
1488 		I802_DEBUG_INC(rx->local->rx_handlers_drop_defrag);
1489 		return RX_DROP_MONITOR;
1490 	}
1491 
1492 	/* Verify that MPDUs within one MSDU have sequential PN values.
1493 	 * (IEEE 802.11i, 8.3.3.4.5) */
1494 	if (entry->ccmp) {
1495 		int i;
1496 		u8 pn[CCMP_PN_LEN], *rpn;
1497 		int queue;
1498 		if (!rx->key || rx->key->conf.cipher != WLAN_CIPHER_SUITE_CCMP)
1499 			return RX_DROP_UNUSABLE;
1500 		memcpy(pn, entry->last_pn, CCMP_PN_LEN);
1501 		for (i = CCMP_PN_LEN - 1; i >= 0; i--) {
1502 			pn[i]++;
1503 			if (pn[i])
1504 				break;
1505 		}
1506 		queue = rx->security_idx;
1507 		rpn = rx->key->u.ccmp.rx_pn[queue];
1508 		if (memcmp(pn, rpn, CCMP_PN_LEN))
1509 			return RX_DROP_UNUSABLE;
1510 		memcpy(entry->last_pn, pn, CCMP_PN_LEN);
1511 	}
1512 
1513 	skb_pull(rx->skb, ieee80211_hdrlen(fc));
1514 	__skb_queue_tail(&entry->skb_list, rx->skb);
1515 	entry->last_frag = frag;
1516 	entry->extra_len += rx->skb->len;
1517 	if (ieee80211_has_morefrags(fc)) {
1518 		rx->skb = NULL;
1519 		return RX_QUEUED;
1520 	}
1521 
1522 	rx->skb = __skb_dequeue(&entry->skb_list);
1523 	if (skb_tailroom(rx->skb) < entry->extra_len) {
1524 		I802_DEBUG_INC(rx->local->rx_expand_skb_head2);
1525 		if (unlikely(pskb_expand_head(rx->skb, 0, entry->extra_len,
1526 					      GFP_ATOMIC))) {
1527 			I802_DEBUG_INC(rx->local->rx_handlers_drop_defrag);
1528 			__skb_queue_purge(&entry->skb_list);
1529 			return RX_DROP_UNUSABLE;
1530 		}
1531 	}
1532 	while ((skb = __skb_dequeue(&entry->skb_list))) {
1533 		memcpy(skb_put(rx->skb, skb->len), skb->data, skb->len);
1534 		dev_kfree_skb(skb);
1535 	}
1536 
1537 	/* Complete frame has been reassembled - process it now */
1538 	status = IEEE80211_SKB_RXCB(rx->skb);
1539 	status->rx_flags |= IEEE80211_RX_FRAGMENTED;
1540 
1541  out:
1542 	if (rx->sta)
1543 		rx->sta->rx_packets++;
1544 	if (is_multicast_ether_addr(hdr->addr1))
1545 		rx->local->dot11MulticastReceivedFrameCount++;
1546 	else
1547 		ieee80211_led_rx(rx->local);
1548 	return RX_CONTINUE;
1549 }
1550 
1551 static ieee80211_rx_result debug_noinline
1552 ieee80211_rx_h_remove_qos_control(struct ieee80211_rx_data *rx)
1553 {
1554 	u8 *data = rx->skb->data;
1555 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)data;
1556 
1557 	if (!ieee80211_is_data_qos(hdr->frame_control))
1558 		return RX_CONTINUE;
1559 
1560 	/* remove the qos control field, update frame type and meta-data */
1561 	memmove(data + IEEE80211_QOS_CTL_LEN, data,
1562 		ieee80211_hdrlen(hdr->frame_control) - IEEE80211_QOS_CTL_LEN);
1563 	hdr = (struct ieee80211_hdr *)skb_pull(rx->skb, IEEE80211_QOS_CTL_LEN);
1564 	/* change frame type to non QOS */
1565 	hdr->frame_control &= ~cpu_to_le16(IEEE80211_STYPE_QOS_DATA);
1566 
1567 	return RX_CONTINUE;
1568 }
1569 
1570 static int
1571 ieee80211_802_1x_port_control(struct ieee80211_rx_data *rx)
1572 {
1573 	if (unlikely(!rx->sta ||
1574 	    !test_sta_flag(rx->sta, WLAN_STA_AUTHORIZED)))
1575 		return -EACCES;
1576 
1577 	return 0;
1578 }
1579 
1580 static int
1581 ieee80211_drop_unencrypted(struct ieee80211_rx_data *rx, __le16 fc)
1582 {
1583 	struct sk_buff *skb = rx->skb;
1584 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
1585 
1586 	/*
1587 	 * Pass through unencrypted frames if the hardware has
1588 	 * decrypted them already.
1589 	 */
1590 	if (status->flag & RX_FLAG_DECRYPTED)
1591 		return 0;
1592 
1593 	/* Drop unencrypted frames if key is set. */
1594 	if (unlikely(!ieee80211_has_protected(fc) &&
1595 		     !ieee80211_is_nullfunc(fc) &&
1596 		     ieee80211_is_data(fc) &&
1597 		     (rx->key || rx->sdata->drop_unencrypted)))
1598 		return -EACCES;
1599 
1600 	return 0;
1601 }
1602 
1603 static int
1604 ieee80211_drop_unencrypted_mgmt(struct ieee80211_rx_data *rx)
1605 {
1606 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
1607 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
1608 	__le16 fc = hdr->frame_control;
1609 
1610 	/*
1611 	 * Pass through unencrypted frames if the hardware has
1612 	 * decrypted them already.
1613 	 */
1614 	if (status->flag & RX_FLAG_DECRYPTED)
1615 		return 0;
1616 
1617 	if (rx->sta && test_sta_flag(rx->sta, WLAN_STA_MFP)) {
1618 		if (unlikely(!ieee80211_has_protected(fc) &&
1619 			     ieee80211_is_unicast_robust_mgmt_frame(rx->skb) &&
1620 			     rx->key)) {
1621 			if (ieee80211_is_deauth(fc))
1622 				cfg80211_send_unprot_deauth(rx->sdata->dev,
1623 							    rx->skb->data,
1624 							    rx->skb->len);
1625 			else if (ieee80211_is_disassoc(fc))
1626 				cfg80211_send_unprot_disassoc(rx->sdata->dev,
1627 							      rx->skb->data,
1628 							      rx->skb->len);
1629 			return -EACCES;
1630 		}
1631 		/* BIP does not use Protected field, so need to check MMIE */
1632 		if (unlikely(ieee80211_is_multicast_robust_mgmt_frame(rx->skb) &&
1633 			     ieee80211_get_mmie_keyidx(rx->skb) < 0)) {
1634 			if (ieee80211_is_deauth(fc))
1635 				cfg80211_send_unprot_deauth(rx->sdata->dev,
1636 							    rx->skb->data,
1637 							    rx->skb->len);
1638 			else if (ieee80211_is_disassoc(fc))
1639 				cfg80211_send_unprot_disassoc(rx->sdata->dev,
1640 							      rx->skb->data,
1641 							      rx->skb->len);
1642 			return -EACCES;
1643 		}
1644 		/*
1645 		 * When using MFP, Action frames are not allowed prior to
1646 		 * having configured keys.
1647 		 */
1648 		if (unlikely(ieee80211_is_action(fc) && !rx->key &&
1649 			     ieee80211_is_robust_mgmt_frame(
1650 				     (struct ieee80211_hdr *) rx->skb->data)))
1651 			return -EACCES;
1652 	}
1653 
1654 	return 0;
1655 }
1656 
1657 static int
1658 __ieee80211_data_to_8023(struct ieee80211_rx_data *rx, bool *port_control)
1659 {
1660 	struct ieee80211_sub_if_data *sdata = rx->sdata;
1661 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
1662 	bool check_port_control = false;
1663 	struct ethhdr *ehdr;
1664 	int ret;
1665 
1666 	*port_control = false;
1667 	if (ieee80211_has_a4(hdr->frame_control) &&
1668 	    sdata->vif.type == NL80211_IFTYPE_AP_VLAN && !sdata->u.vlan.sta)
1669 		return -1;
1670 
1671 	if (sdata->vif.type == NL80211_IFTYPE_STATION &&
1672 	    !!sdata->u.mgd.use_4addr != !!ieee80211_has_a4(hdr->frame_control)) {
1673 
1674 		if (!sdata->u.mgd.use_4addr)
1675 			return -1;
1676 		else
1677 			check_port_control = true;
1678 	}
1679 
1680 	if (is_multicast_ether_addr(hdr->addr1) &&
1681 	    sdata->vif.type == NL80211_IFTYPE_AP_VLAN && sdata->u.vlan.sta)
1682 		return -1;
1683 
1684 	ret = ieee80211_data_to_8023(rx->skb, sdata->vif.addr, sdata->vif.type);
1685 	if (ret < 0)
1686 		return ret;
1687 
1688 	ehdr = (struct ethhdr *) rx->skb->data;
1689 	if (ehdr->h_proto == rx->sdata->control_port_protocol)
1690 		*port_control = true;
1691 	else if (check_port_control)
1692 		return -1;
1693 
1694 	return 0;
1695 }
1696 
1697 /*
1698  * requires that rx->skb is a frame with ethernet header
1699  */
1700 static bool ieee80211_frame_allowed(struct ieee80211_rx_data *rx, __le16 fc)
1701 {
1702 	static const u8 pae_group_addr[ETH_ALEN] __aligned(2)
1703 		= { 0x01, 0x80, 0xC2, 0x00, 0x00, 0x03 };
1704 	struct ethhdr *ehdr = (struct ethhdr *) rx->skb->data;
1705 
1706 	/*
1707 	 * Allow EAPOL frames to us/the PAE group address regardless
1708 	 * of whether the frame was encrypted or not.
1709 	 */
1710 	if (ehdr->h_proto == rx->sdata->control_port_protocol &&
1711 	    (compare_ether_addr(ehdr->h_dest, rx->sdata->vif.addr) == 0 ||
1712 	     compare_ether_addr(ehdr->h_dest, pae_group_addr) == 0))
1713 		return true;
1714 
1715 	if (ieee80211_802_1x_port_control(rx) ||
1716 	    ieee80211_drop_unencrypted(rx, fc))
1717 		return false;
1718 
1719 	return true;
1720 }
1721 
1722 /*
1723  * requires that rx->skb is a frame with ethernet header
1724  */
1725 static void
1726 ieee80211_deliver_skb(struct ieee80211_rx_data *rx)
1727 {
1728 	struct ieee80211_sub_if_data *sdata = rx->sdata;
1729 	struct net_device *dev = sdata->dev;
1730 	struct sk_buff *skb, *xmit_skb;
1731 	struct ethhdr *ehdr = (struct ethhdr *) rx->skb->data;
1732 	struct sta_info *dsta;
1733 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
1734 
1735 	skb = rx->skb;
1736 	xmit_skb = NULL;
1737 
1738 	if ((sdata->vif.type == NL80211_IFTYPE_AP ||
1739 	     sdata->vif.type == NL80211_IFTYPE_AP_VLAN) &&
1740 	    !(sdata->flags & IEEE80211_SDATA_DONT_BRIDGE_PACKETS) &&
1741 	    (status->rx_flags & IEEE80211_RX_RA_MATCH) &&
1742 	    (sdata->vif.type != NL80211_IFTYPE_AP_VLAN || !sdata->u.vlan.sta)) {
1743 		if (is_multicast_ether_addr(ehdr->h_dest)) {
1744 			/*
1745 			 * send multicast frames both to higher layers in
1746 			 * local net stack and back to the wireless medium
1747 			 */
1748 			xmit_skb = skb_copy(skb, GFP_ATOMIC);
1749 			if (!xmit_skb && net_ratelimit())
1750 				printk(KERN_DEBUG "%s: failed to clone "
1751 				       "multicast frame\n", dev->name);
1752 		} else {
1753 			dsta = sta_info_get(sdata, skb->data);
1754 			if (dsta) {
1755 				/*
1756 				 * The destination station is associated to
1757 				 * this AP (in this VLAN), so send the frame
1758 				 * directly to it and do not pass it to local
1759 				 * net stack.
1760 				 */
1761 				xmit_skb = skb;
1762 				skb = NULL;
1763 			}
1764 		}
1765 	}
1766 
1767 	if (skb) {
1768 		int align __maybe_unused;
1769 
1770 #ifndef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
1771 		/*
1772 		 * 'align' will only take the values 0 or 2 here
1773 		 * since all frames are required to be aligned
1774 		 * to 2-byte boundaries when being passed to
1775 		 * mac80211. That also explains the __skb_push()
1776 		 * below.
1777 		 */
1778 		align = ((unsigned long)(skb->data + sizeof(struct ethhdr))) & 3;
1779 		if (align) {
1780 			if (WARN_ON(skb_headroom(skb) < 3)) {
1781 				dev_kfree_skb(skb);
1782 				skb = NULL;
1783 			} else {
1784 				u8 *data = skb->data;
1785 				size_t len = skb_headlen(skb);
1786 				skb->data -= align;
1787 				memmove(skb->data, data, len);
1788 				skb_set_tail_pointer(skb, len);
1789 			}
1790 		}
1791 #endif
1792 
1793 		if (skb) {
1794 			/* deliver to local stack */
1795 			skb->protocol = eth_type_trans(skb, dev);
1796 			memset(skb->cb, 0, sizeof(skb->cb));
1797 			netif_receive_skb(skb);
1798 		}
1799 	}
1800 
1801 	if (xmit_skb) {
1802 		/* send to wireless media */
1803 		xmit_skb->protocol = htons(ETH_P_802_3);
1804 		skb_reset_network_header(xmit_skb);
1805 		skb_reset_mac_header(xmit_skb);
1806 		dev_queue_xmit(xmit_skb);
1807 	}
1808 }
1809 
1810 static ieee80211_rx_result debug_noinline
1811 ieee80211_rx_h_amsdu(struct ieee80211_rx_data *rx)
1812 {
1813 	struct net_device *dev = rx->sdata->dev;
1814 	struct sk_buff *skb = rx->skb;
1815 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
1816 	__le16 fc = hdr->frame_control;
1817 	struct sk_buff_head frame_list;
1818 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
1819 
1820 	if (unlikely(!ieee80211_is_data(fc)))
1821 		return RX_CONTINUE;
1822 
1823 	if (unlikely(!ieee80211_is_data_present(fc)))
1824 		return RX_DROP_MONITOR;
1825 
1826 	if (!(status->rx_flags & IEEE80211_RX_AMSDU))
1827 		return RX_CONTINUE;
1828 
1829 	if (ieee80211_has_a4(hdr->frame_control) &&
1830 	    rx->sdata->vif.type == NL80211_IFTYPE_AP_VLAN &&
1831 	    !rx->sdata->u.vlan.sta)
1832 		return RX_DROP_UNUSABLE;
1833 
1834 	if (is_multicast_ether_addr(hdr->addr1) &&
1835 	    ((rx->sdata->vif.type == NL80211_IFTYPE_AP_VLAN &&
1836 	      rx->sdata->u.vlan.sta) ||
1837 	     (rx->sdata->vif.type == NL80211_IFTYPE_STATION &&
1838 	      rx->sdata->u.mgd.use_4addr)))
1839 		return RX_DROP_UNUSABLE;
1840 
1841 	skb->dev = dev;
1842 	__skb_queue_head_init(&frame_list);
1843 
1844 	if (skb_linearize(skb))
1845 		return RX_DROP_UNUSABLE;
1846 
1847 	ieee80211_amsdu_to_8023s(skb, &frame_list, dev->dev_addr,
1848 				 rx->sdata->vif.type,
1849 				 rx->local->hw.extra_tx_headroom, true);
1850 
1851 	while (!skb_queue_empty(&frame_list)) {
1852 		rx->skb = __skb_dequeue(&frame_list);
1853 
1854 		if (!ieee80211_frame_allowed(rx, fc)) {
1855 			dev_kfree_skb(rx->skb);
1856 			continue;
1857 		}
1858 		dev->stats.rx_packets++;
1859 		dev->stats.rx_bytes += rx->skb->len;
1860 
1861 		ieee80211_deliver_skb(rx);
1862 	}
1863 
1864 	return RX_QUEUED;
1865 }
1866 
1867 #ifdef CONFIG_MAC80211_MESH
1868 static ieee80211_rx_result
1869 ieee80211_rx_h_mesh_fwding(struct ieee80211_rx_data *rx)
1870 {
1871 	struct ieee80211_hdr *hdr;
1872 	struct ieee80211s_hdr *mesh_hdr;
1873 	unsigned int hdrlen;
1874 	struct sk_buff *skb = rx->skb, *fwd_skb;
1875 	struct ieee80211_local *local = rx->local;
1876 	struct ieee80211_sub_if_data *sdata = rx->sdata;
1877 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
1878 
1879 	hdr = (struct ieee80211_hdr *) skb->data;
1880 	hdrlen = ieee80211_hdrlen(hdr->frame_control);
1881 	mesh_hdr = (struct ieee80211s_hdr *) (skb->data + hdrlen);
1882 
1883 	/* frame is in RMC, don't forward */
1884 	if (ieee80211_is_data(hdr->frame_control) &&
1885 	    is_multicast_ether_addr(hdr->addr1) &&
1886 	    mesh_rmc_check(hdr->addr3, mesh_hdr, rx->sdata))
1887 		return RX_DROP_MONITOR;
1888 
1889 	if (!ieee80211_is_data(hdr->frame_control))
1890 		return RX_CONTINUE;
1891 
1892 	if (!mesh_hdr->ttl)
1893 		/* illegal frame */
1894 		return RX_DROP_MONITOR;
1895 
1896 	if (ieee80211_queue_stopped(&local->hw, skb_get_queue_mapping(skb))) {
1897 		IEEE80211_IFSTA_MESH_CTR_INC(&sdata->u.mesh,
1898 						dropped_frames_congestion);
1899 		return RX_DROP_MONITOR;
1900 	}
1901 
1902 	if (mesh_hdr->flags & MESH_FLAGS_AE) {
1903 		struct mesh_path *mppath;
1904 		char *proxied_addr;
1905 		char *mpp_addr;
1906 
1907 		if (is_multicast_ether_addr(hdr->addr1)) {
1908 			mpp_addr = hdr->addr3;
1909 			proxied_addr = mesh_hdr->eaddr1;
1910 		} else {
1911 			mpp_addr = hdr->addr4;
1912 			proxied_addr = mesh_hdr->eaddr2;
1913 		}
1914 
1915 		rcu_read_lock();
1916 		mppath = mpp_path_lookup(proxied_addr, sdata);
1917 		if (!mppath) {
1918 			mpp_path_add(proxied_addr, mpp_addr, sdata);
1919 		} else {
1920 			spin_lock_bh(&mppath->state_lock);
1921 			if (compare_ether_addr(mppath->mpp, mpp_addr) != 0)
1922 				memcpy(mppath->mpp, mpp_addr, ETH_ALEN);
1923 			spin_unlock_bh(&mppath->state_lock);
1924 		}
1925 		rcu_read_unlock();
1926 	}
1927 
1928 	/* Frame has reached destination.  Don't forward */
1929 	if (!is_multicast_ether_addr(hdr->addr1) &&
1930 	    compare_ether_addr(sdata->vif.addr, hdr->addr3) == 0)
1931 		return RX_CONTINUE;
1932 
1933 	mesh_hdr->ttl--;
1934 
1935 	if (status->rx_flags & IEEE80211_RX_RA_MATCH) {
1936 		if (!mesh_hdr->ttl)
1937 			IEEE80211_IFSTA_MESH_CTR_INC(&rx->sdata->u.mesh,
1938 						     dropped_frames_ttl);
1939 		else {
1940 			struct ieee80211_hdr *fwd_hdr;
1941 			struct ieee80211_tx_info *info;
1942 
1943 			fwd_skb = skb_copy(skb, GFP_ATOMIC);
1944 
1945 			if (!fwd_skb && net_ratelimit())
1946 				printk(KERN_DEBUG "%s: failed to clone mesh frame\n",
1947 						   sdata->name);
1948 			if (!fwd_skb)
1949 				goto out;
1950 
1951 			fwd_hdr =  (struct ieee80211_hdr *) fwd_skb->data;
1952 			memcpy(fwd_hdr->addr2, sdata->vif.addr, ETH_ALEN);
1953 			info = IEEE80211_SKB_CB(fwd_skb);
1954 			memset(info, 0, sizeof(*info));
1955 			info->flags |= IEEE80211_TX_INTFL_NEED_TXPROCESSING;
1956 			info->control.vif = &rx->sdata->vif;
1957 			if (is_multicast_ether_addr(fwd_hdr->addr1)) {
1958 				IEEE80211_IFSTA_MESH_CTR_INC(&sdata->u.mesh,
1959 								fwded_mcast);
1960 				skb_set_queue_mapping(fwd_skb,
1961 					ieee80211_select_queue(sdata, fwd_skb));
1962 				ieee80211_set_qos_hdr(sdata, fwd_skb);
1963 			} else {
1964 				int err;
1965 				/*
1966 				 * Save TA to addr1 to send TA a path error if a
1967 				 * suitable next hop is not found
1968 				 */
1969 				memcpy(fwd_hdr->addr1, fwd_hdr->addr2,
1970 						ETH_ALEN);
1971 				err = mesh_nexthop_lookup(fwd_skb, sdata);
1972 				/* Failed to immediately resolve next hop:
1973 				 * fwded frame was dropped or will be added
1974 				 * later to the pending skb queue.  */
1975 				if (err)
1976 					return RX_DROP_MONITOR;
1977 
1978 				IEEE80211_IFSTA_MESH_CTR_INC(&sdata->u.mesh,
1979 								fwded_unicast);
1980 			}
1981 			IEEE80211_IFSTA_MESH_CTR_INC(&sdata->u.mesh,
1982 						     fwded_frames);
1983 			ieee80211_add_pending_skb(local, fwd_skb);
1984 		}
1985 	}
1986 
1987  out:
1988 	if (is_multicast_ether_addr(hdr->addr1) ||
1989 	    sdata->dev->flags & IFF_PROMISC)
1990 		return RX_CONTINUE;
1991 	else
1992 		return RX_DROP_MONITOR;
1993 }
1994 #endif
1995 
1996 static ieee80211_rx_result debug_noinline
1997 ieee80211_rx_h_data(struct ieee80211_rx_data *rx)
1998 {
1999 	struct ieee80211_sub_if_data *sdata = rx->sdata;
2000 	struct ieee80211_local *local = rx->local;
2001 	struct net_device *dev = sdata->dev;
2002 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
2003 	__le16 fc = hdr->frame_control;
2004 	bool port_control;
2005 	int err;
2006 
2007 	if (unlikely(!ieee80211_is_data(hdr->frame_control)))
2008 		return RX_CONTINUE;
2009 
2010 	if (unlikely(!ieee80211_is_data_present(hdr->frame_control)))
2011 		return RX_DROP_MONITOR;
2012 
2013 	/*
2014 	 * Allow the cooked monitor interface of an AP to see 4-addr frames so
2015 	 * that a 4-addr station can be detected and moved into a separate VLAN
2016 	 */
2017 	if (ieee80211_has_a4(hdr->frame_control) &&
2018 	    sdata->vif.type == NL80211_IFTYPE_AP)
2019 		return RX_DROP_MONITOR;
2020 
2021 	err = __ieee80211_data_to_8023(rx, &port_control);
2022 	if (unlikely(err))
2023 		return RX_DROP_UNUSABLE;
2024 
2025 	if (!ieee80211_frame_allowed(rx, fc))
2026 		return RX_DROP_MONITOR;
2027 
2028 	if (rx->sdata->vif.type == NL80211_IFTYPE_AP_VLAN &&
2029 	    unlikely(port_control) && sdata->bss) {
2030 		sdata = container_of(sdata->bss, struct ieee80211_sub_if_data,
2031 				     u.ap);
2032 		dev = sdata->dev;
2033 		rx->sdata = sdata;
2034 	}
2035 
2036 	rx->skb->dev = dev;
2037 
2038 	dev->stats.rx_packets++;
2039 	dev->stats.rx_bytes += rx->skb->len;
2040 
2041 	if (local->ps_sdata && local->hw.conf.dynamic_ps_timeout > 0 &&
2042 	    !is_multicast_ether_addr(
2043 		    ((struct ethhdr *)rx->skb->data)->h_dest) &&
2044 	    (!local->scanning &&
2045 	     !test_bit(SDATA_STATE_OFFCHANNEL, &sdata->state))) {
2046 			mod_timer(&local->dynamic_ps_timer, jiffies +
2047 			 msecs_to_jiffies(local->hw.conf.dynamic_ps_timeout));
2048 	}
2049 
2050 	ieee80211_deliver_skb(rx);
2051 
2052 	return RX_QUEUED;
2053 }
2054 
2055 static ieee80211_rx_result debug_noinline
2056 ieee80211_rx_h_ctrl(struct ieee80211_rx_data *rx)
2057 {
2058 	struct ieee80211_local *local = rx->local;
2059 	struct ieee80211_hw *hw = &local->hw;
2060 	struct sk_buff *skb = rx->skb;
2061 	struct ieee80211_bar *bar = (struct ieee80211_bar *)skb->data;
2062 	struct tid_ampdu_rx *tid_agg_rx;
2063 	u16 start_seq_num;
2064 	u16 tid;
2065 
2066 	if (likely(!ieee80211_is_ctl(bar->frame_control)))
2067 		return RX_CONTINUE;
2068 
2069 	if (ieee80211_is_back_req(bar->frame_control)) {
2070 		struct {
2071 			__le16 control, start_seq_num;
2072 		} __packed bar_data;
2073 
2074 		if (!rx->sta)
2075 			return RX_DROP_MONITOR;
2076 
2077 		if (skb_copy_bits(skb, offsetof(struct ieee80211_bar, control),
2078 				  &bar_data, sizeof(bar_data)))
2079 			return RX_DROP_MONITOR;
2080 
2081 		tid = le16_to_cpu(bar_data.control) >> 12;
2082 
2083 		tid_agg_rx = rcu_dereference(rx->sta->ampdu_mlme.tid_rx[tid]);
2084 		if (!tid_agg_rx)
2085 			return RX_DROP_MONITOR;
2086 
2087 		start_seq_num = le16_to_cpu(bar_data.start_seq_num) >> 4;
2088 
2089 		/* reset session timer */
2090 		if (tid_agg_rx->timeout)
2091 			mod_timer(&tid_agg_rx->session_timer,
2092 				  TU_TO_EXP_TIME(tid_agg_rx->timeout));
2093 
2094 		spin_lock(&tid_agg_rx->reorder_lock);
2095 		/* release stored frames up to start of BAR */
2096 		ieee80211_release_reorder_frames(hw, tid_agg_rx, start_seq_num);
2097 		spin_unlock(&tid_agg_rx->reorder_lock);
2098 
2099 		kfree_skb(skb);
2100 		return RX_QUEUED;
2101 	}
2102 
2103 	/*
2104 	 * After this point, we only want management frames,
2105 	 * so we can drop all remaining control frames to
2106 	 * cooked monitor interfaces.
2107 	 */
2108 	return RX_DROP_MONITOR;
2109 }
2110 
2111 static void ieee80211_process_sa_query_req(struct ieee80211_sub_if_data *sdata,
2112 					   struct ieee80211_mgmt *mgmt,
2113 					   size_t len)
2114 {
2115 	struct ieee80211_local *local = sdata->local;
2116 	struct sk_buff *skb;
2117 	struct ieee80211_mgmt *resp;
2118 
2119 	if (compare_ether_addr(mgmt->da, sdata->vif.addr) != 0) {
2120 		/* Not to own unicast address */
2121 		return;
2122 	}
2123 
2124 	if (compare_ether_addr(mgmt->sa, sdata->u.mgd.bssid) != 0 ||
2125 	    compare_ether_addr(mgmt->bssid, sdata->u.mgd.bssid) != 0) {
2126 		/* Not from the current AP or not associated yet. */
2127 		return;
2128 	}
2129 
2130 	if (len < 24 + 1 + sizeof(resp->u.action.u.sa_query)) {
2131 		/* Too short SA Query request frame */
2132 		return;
2133 	}
2134 
2135 	skb = dev_alloc_skb(sizeof(*resp) + local->hw.extra_tx_headroom);
2136 	if (skb == NULL)
2137 		return;
2138 
2139 	skb_reserve(skb, local->hw.extra_tx_headroom);
2140 	resp = (struct ieee80211_mgmt *) skb_put(skb, 24);
2141 	memset(resp, 0, 24);
2142 	memcpy(resp->da, mgmt->sa, ETH_ALEN);
2143 	memcpy(resp->sa, sdata->vif.addr, ETH_ALEN);
2144 	memcpy(resp->bssid, sdata->u.mgd.bssid, ETH_ALEN);
2145 	resp->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
2146 					  IEEE80211_STYPE_ACTION);
2147 	skb_put(skb, 1 + sizeof(resp->u.action.u.sa_query));
2148 	resp->u.action.category = WLAN_CATEGORY_SA_QUERY;
2149 	resp->u.action.u.sa_query.action = WLAN_ACTION_SA_QUERY_RESPONSE;
2150 	memcpy(resp->u.action.u.sa_query.trans_id,
2151 	       mgmt->u.action.u.sa_query.trans_id,
2152 	       WLAN_SA_QUERY_TR_ID_LEN);
2153 
2154 	ieee80211_tx_skb(sdata, skb);
2155 }
2156 
2157 static ieee80211_rx_result debug_noinline
2158 ieee80211_rx_h_mgmt_check(struct ieee80211_rx_data *rx)
2159 {
2160 	struct ieee80211_mgmt *mgmt = (struct ieee80211_mgmt *) rx->skb->data;
2161 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
2162 
2163 	/*
2164 	 * From here on, look only at management frames.
2165 	 * Data and control frames are already handled,
2166 	 * and unknown (reserved) frames are useless.
2167 	 */
2168 	if (rx->skb->len < 24)
2169 		return RX_DROP_MONITOR;
2170 
2171 	if (!ieee80211_is_mgmt(mgmt->frame_control))
2172 		return RX_DROP_MONITOR;
2173 
2174 	if (!(status->rx_flags & IEEE80211_RX_RA_MATCH))
2175 		return RX_DROP_MONITOR;
2176 
2177 	if (ieee80211_drop_unencrypted_mgmt(rx))
2178 		return RX_DROP_UNUSABLE;
2179 
2180 	return RX_CONTINUE;
2181 }
2182 
2183 static ieee80211_rx_result debug_noinline
2184 ieee80211_rx_h_action(struct ieee80211_rx_data *rx)
2185 {
2186 	struct ieee80211_local *local = rx->local;
2187 	struct ieee80211_sub_if_data *sdata = rx->sdata;
2188 	struct ieee80211_mgmt *mgmt = (struct ieee80211_mgmt *) rx->skb->data;
2189 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
2190 	int len = rx->skb->len;
2191 
2192 	if (!ieee80211_is_action(mgmt->frame_control))
2193 		return RX_CONTINUE;
2194 
2195 	/* drop too small frames */
2196 	if (len < IEEE80211_MIN_ACTION_SIZE)
2197 		return RX_DROP_UNUSABLE;
2198 
2199 	if (!rx->sta && mgmt->u.action.category != WLAN_CATEGORY_PUBLIC)
2200 		return RX_DROP_UNUSABLE;
2201 
2202 	if (!(status->rx_flags & IEEE80211_RX_RA_MATCH))
2203 		return RX_DROP_UNUSABLE;
2204 
2205 	switch (mgmt->u.action.category) {
2206 	case WLAN_CATEGORY_BACK:
2207 		/*
2208 		 * The aggregation code is not prepared to handle
2209 		 * anything but STA/AP due to the BSSID handling;
2210 		 * IBSS could work in the code but isn't supported
2211 		 * by drivers or the standard.
2212 		 */
2213 		if (sdata->vif.type != NL80211_IFTYPE_STATION &&
2214 		    sdata->vif.type != NL80211_IFTYPE_AP_VLAN &&
2215 		    sdata->vif.type != NL80211_IFTYPE_AP)
2216 			break;
2217 
2218 		/* verify action_code is present */
2219 		if (len < IEEE80211_MIN_ACTION_SIZE + 1)
2220 			break;
2221 
2222 		switch (mgmt->u.action.u.addba_req.action_code) {
2223 		case WLAN_ACTION_ADDBA_REQ:
2224 			if (len < (IEEE80211_MIN_ACTION_SIZE +
2225 				   sizeof(mgmt->u.action.u.addba_req)))
2226 				goto invalid;
2227 			break;
2228 		case WLAN_ACTION_ADDBA_RESP:
2229 			if (len < (IEEE80211_MIN_ACTION_SIZE +
2230 				   sizeof(mgmt->u.action.u.addba_resp)))
2231 				goto invalid;
2232 			break;
2233 		case WLAN_ACTION_DELBA:
2234 			if (len < (IEEE80211_MIN_ACTION_SIZE +
2235 				   sizeof(mgmt->u.action.u.delba)))
2236 				goto invalid;
2237 			break;
2238 		default:
2239 			goto invalid;
2240 		}
2241 
2242 		goto queue;
2243 	case WLAN_CATEGORY_SPECTRUM_MGMT:
2244 		if (local->hw.conf.channel->band != IEEE80211_BAND_5GHZ)
2245 			break;
2246 
2247 		if (sdata->vif.type != NL80211_IFTYPE_STATION)
2248 			break;
2249 
2250 		/* verify action_code is present */
2251 		if (len < IEEE80211_MIN_ACTION_SIZE + 1)
2252 			break;
2253 
2254 		switch (mgmt->u.action.u.measurement.action_code) {
2255 		case WLAN_ACTION_SPCT_MSR_REQ:
2256 			if (len < (IEEE80211_MIN_ACTION_SIZE +
2257 				   sizeof(mgmt->u.action.u.measurement)))
2258 				break;
2259 			ieee80211_process_measurement_req(sdata, mgmt, len);
2260 			goto handled;
2261 		case WLAN_ACTION_SPCT_CHL_SWITCH:
2262 			if (len < (IEEE80211_MIN_ACTION_SIZE +
2263 				   sizeof(mgmt->u.action.u.chan_switch)))
2264 				break;
2265 
2266 			if (sdata->vif.type != NL80211_IFTYPE_STATION)
2267 				break;
2268 
2269 			if (memcmp(mgmt->bssid, sdata->u.mgd.bssid, ETH_ALEN))
2270 				break;
2271 
2272 			goto queue;
2273 		}
2274 		break;
2275 	case WLAN_CATEGORY_SA_QUERY:
2276 		if (len < (IEEE80211_MIN_ACTION_SIZE +
2277 			   sizeof(mgmt->u.action.u.sa_query)))
2278 			break;
2279 
2280 		switch (mgmt->u.action.u.sa_query.action) {
2281 		case WLAN_ACTION_SA_QUERY_REQUEST:
2282 			if (sdata->vif.type != NL80211_IFTYPE_STATION)
2283 				break;
2284 			ieee80211_process_sa_query_req(sdata, mgmt, len);
2285 			goto handled;
2286 		}
2287 		break;
2288 	case WLAN_CATEGORY_SELF_PROTECTED:
2289 		switch (mgmt->u.action.u.self_prot.action_code) {
2290 		case WLAN_SP_MESH_PEERING_OPEN:
2291 		case WLAN_SP_MESH_PEERING_CLOSE:
2292 		case WLAN_SP_MESH_PEERING_CONFIRM:
2293 			if (!ieee80211_vif_is_mesh(&sdata->vif))
2294 				goto invalid;
2295 			if (sdata->u.mesh.security != IEEE80211_MESH_SEC_NONE)
2296 				/* userspace handles this frame */
2297 				break;
2298 			goto queue;
2299 		case WLAN_SP_MGK_INFORM:
2300 		case WLAN_SP_MGK_ACK:
2301 			if (!ieee80211_vif_is_mesh(&sdata->vif))
2302 				goto invalid;
2303 			break;
2304 		}
2305 		break;
2306 	case WLAN_CATEGORY_MESH_ACTION:
2307 		if (!ieee80211_vif_is_mesh(&sdata->vif))
2308 			break;
2309 		if (mesh_action_is_path_sel(mgmt) &&
2310 		  (!mesh_path_sel_is_hwmp(sdata)))
2311 			break;
2312 		goto queue;
2313 	}
2314 
2315 	return RX_CONTINUE;
2316 
2317  invalid:
2318 	status->rx_flags |= IEEE80211_RX_MALFORMED_ACTION_FRM;
2319 	/* will return in the next handlers */
2320 	return RX_CONTINUE;
2321 
2322  handled:
2323 	if (rx->sta)
2324 		rx->sta->rx_packets++;
2325 	dev_kfree_skb(rx->skb);
2326 	return RX_QUEUED;
2327 
2328  queue:
2329 	rx->skb->pkt_type = IEEE80211_SDATA_QUEUE_TYPE_FRAME;
2330 	skb_queue_tail(&sdata->skb_queue, rx->skb);
2331 	ieee80211_queue_work(&local->hw, &sdata->work);
2332 	if (rx->sta)
2333 		rx->sta->rx_packets++;
2334 	return RX_QUEUED;
2335 }
2336 
2337 static ieee80211_rx_result debug_noinline
2338 ieee80211_rx_h_userspace_mgmt(struct ieee80211_rx_data *rx)
2339 {
2340 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
2341 
2342 	/* skip known-bad action frames and return them in the next handler */
2343 	if (status->rx_flags & IEEE80211_RX_MALFORMED_ACTION_FRM)
2344 		return RX_CONTINUE;
2345 
2346 	/*
2347 	 * Getting here means the kernel doesn't know how to handle
2348 	 * it, but maybe userspace does ... include returned frames
2349 	 * so userspace can register for those to know whether ones
2350 	 * it transmitted were processed or returned.
2351 	 */
2352 
2353 	if (cfg80211_rx_mgmt(rx->sdata->dev, status->freq,
2354 			     rx->skb->data, rx->skb->len,
2355 			     GFP_ATOMIC)) {
2356 		if (rx->sta)
2357 			rx->sta->rx_packets++;
2358 		dev_kfree_skb(rx->skb);
2359 		return RX_QUEUED;
2360 	}
2361 
2362 
2363 	return RX_CONTINUE;
2364 }
2365 
2366 static ieee80211_rx_result debug_noinline
2367 ieee80211_rx_h_action_return(struct ieee80211_rx_data *rx)
2368 {
2369 	struct ieee80211_local *local = rx->local;
2370 	struct ieee80211_mgmt *mgmt = (struct ieee80211_mgmt *) rx->skb->data;
2371 	struct sk_buff *nskb;
2372 	struct ieee80211_sub_if_data *sdata = rx->sdata;
2373 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
2374 
2375 	if (!ieee80211_is_action(mgmt->frame_control))
2376 		return RX_CONTINUE;
2377 
2378 	/*
2379 	 * For AP mode, hostapd is responsible for handling any action
2380 	 * frames that we didn't handle, including returning unknown
2381 	 * ones. For all other modes we will return them to the sender,
2382 	 * setting the 0x80 bit in the action category, as required by
2383 	 * 802.11-2007 7.3.1.11.
2384 	 * Newer versions of hostapd shall also use the management frame
2385 	 * registration mechanisms, but older ones still use cooked
2386 	 * monitor interfaces so push all frames there.
2387 	 */
2388 	if (!(status->rx_flags & IEEE80211_RX_MALFORMED_ACTION_FRM) &&
2389 	    (sdata->vif.type == NL80211_IFTYPE_AP ||
2390 	     sdata->vif.type == NL80211_IFTYPE_AP_VLAN))
2391 		return RX_DROP_MONITOR;
2392 
2393 	/* do not return rejected action frames */
2394 	if (mgmt->u.action.category & 0x80)
2395 		return RX_DROP_UNUSABLE;
2396 
2397 	nskb = skb_copy_expand(rx->skb, local->hw.extra_tx_headroom, 0,
2398 			       GFP_ATOMIC);
2399 	if (nskb) {
2400 		struct ieee80211_mgmt *nmgmt = (void *)nskb->data;
2401 
2402 		nmgmt->u.action.category |= 0x80;
2403 		memcpy(nmgmt->da, nmgmt->sa, ETH_ALEN);
2404 		memcpy(nmgmt->sa, rx->sdata->vif.addr, ETH_ALEN);
2405 
2406 		memset(nskb->cb, 0, sizeof(nskb->cb));
2407 
2408 		ieee80211_tx_skb(rx->sdata, nskb);
2409 	}
2410 	dev_kfree_skb(rx->skb);
2411 	return RX_QUEUED;
2412 }
2413 
2414 static ieee80211_rx_result debug_noinline
2415 ieee80211_rx_h_mgmt(struct ieee80211_rx_data *rx)
2416 {
2417 	struct ieee80211_sub_if_data *sdata = rx->sdata;
2418 	ieee80211_rx_result rxs;
2419 	struct ieee80211_mgmt *mgmt = (void *)rx->skb->data;
2420 	__le16 stype;
2421 
2422 	rxs = ieee80211_work_rx_mgmt(rx->sdata, rx->skb);
2423 	if (rxs != RX_CONTINUE)
2424 		return rxs;
2425 
2426 	stype = mgmt->frame_control & cpu_to_le16(IEEE80211_FCTL_STYPE);
2427 
2428 	if (!ieee80211_vif_is_mesh(&sdata->vif) &&
2429 	    sdata->vif.type != NL80211_IFTYPE_ADHOC &&
2430 	    sdata->vif.type != NL80211_IFTYPE_STATION)
2431 		return RX_DROP_MONITOR;
2432 
2433 	switch (stype) {
2434 	case cpu_to_le16(IEEE80211_STYPE_BEACON):
2435 	case cpu_to_le16(IEEE80211_STYPE_PROBE_RESP):
2436 		/* process for all: mesh, mlme, ibss */
2437 		break;
2438 	case cpu_to_le16(IEEE80211_STYPE_DEAUTH):
2439 	case cpu_to_le16(IEEE80211_STYPE_DISASSOC):
2440 		if (is_multicast_ether_addr(mgmt->da) &&
2441 		    !is_broadcast_ether_addr(mgmt->da))
2442 			return RX_DROP_MONITOR;
2443 
2444 		/* process only for station */
2445 		if (sdata->vif.type != NL80211_IFTYPE_STATION)
2446 			return RX_DROP_MONITOR;
2447 		break;
2448 	case cpu_to_le16(IEEE80211_STYPE_PROBE_REQ):
2449 	case cpu_to_le16(IEEE80211_STYPE_AUTH):
2450 		/* process only for ibss */
2451 		if (sdata->vif.type != NL80211_IFTYPE_ADHOC)
2452 			return RX_DROP_MONITOR;
2453 		break;
2454 	default:
2455 		return RX_DROP_MONITOR;
2456 	}
2457 
2458 	/* queue up frame and kick off work to process it */
2459 	rx->skb->pkt_type = IEEE80211_SDATA_QUEUE_TYPE_FRAME;
2460 	skb_queue_tail(&sdata->skb_queue, rx->skb);
2461 	ieee80211_queue_work(&rx->local->hw, &sdata->work);
2462 	if (rx->sta)
2463 		rx->sta->rx_packets++;
2464 
2465 	return RX_QUEUED;
2466 }
2467 
2468 /* TODO: use IEEE80211_RX_FRAGMENTED */
2469 static void ieee80211_rx_cooked_monitor(struct ieee80211_rx_data *rx,
2470 					struct ieee80211_rate *rate)
2471 {
2472 	struct ieee80211_sub_if_data *sdata;
2473 	struct ieee80211_local *local = rx->local;
2474 	struct ieee80211_rtap_hdr {
2475 		struct ieee80211_radiotap_header hdr;
2476 		u8 flags;
2477 		u8 rate_or_pad;
2478 		__le16 chan_freq;
2479 		__le16 chan_flags;
2480 	} __packed *rthdr;
2481 	struct sk_buff *skb = rx->skb, *skb2;
2482 	struct net_device *prev_dev = NULL;
2483 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
2484 
2485 	/*
2486 	 * If cooked monitor has been processed already, then
2487 	 * don't do it again. If not, set the flag.
2488 	 */
2489 	if (rx->flags & IEEE80211_RX_CMNTR)
2490 		goto out_free_skb;
2491 	rx->flags |= IEEE80211_RX_CMNTR;
2492 
2493 	if (skb_headroom(skb) < sizeof(*rthdr) &&
2494 	    pskb_expand_head(skb, sizeof(*rthdr), 0, GFP_ATOMIC))
2495 		goto out_free_skb;
2496 
2497 	rthdr = (void *)skb_push(skb, sizeof(*rthdr));
2498 	memset(rthdr, 0, sizeof(*rthdr));
2499 	rthdr->hdr.it_len = cpu_to_le16(sizeof(*rthdr));
2500 	rthdr->hdr.it_present =
2501 		cpu_to_le32((1 << IEEE80211_RADIOTAP_FLAGS) |
2502 			    (1 << IEEE80211_RADIOTAP_CHANNEL));
2503 
2504 	if (rate) {
2505 		rthdr->rate_or_pad = rate->bitrate / 5;
2506 		rthdr->hdr.it_present |=
2507 			cpu_to_le32(1 << IEEE80211_RADIOTAP_RATE);
2508 	}
2509 	rthdr->chan_freq = cpu_to_le16(status->freq);
2510 
2511 	if (status->band == IEEE80211_BAND_5GHZ)
2512 		rthdr->chan_flags = cpu_to_le16(IEEE80211_CHAN_OFDM |
2513 						IEEE80211_CHAN_5GHZ);
2514 	else
2515 		rthdr->chan_flags = cpu_to_le16(IEEE80211_CHAN_DYN |
2516 						IEEE80211_CHAN_2GHZ);
2517 
2518 	skb_set_mac_header(skb, 0);
2519 	skb->ip_summed = CHECKSUM_UNNECESSARY;
2520 	skb->pkt_type = PACKET_OTHERHOST;
2521 	skb->protocol = htons(ETH_P_802_2);
2522 
2523 	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
2524 		if (!ieee80211_sdata_running(sdata))
2525 			continue;
2526 
2527 		if (sdata->vif.type != NL80211_IFTYPE_MONITOR ||
2528 		    !(sdata->u.mntr_flags & MONITOR_FLAG_COOK_FRAMES))
2529 			continue;
2530 
2531 		if (prev_dev) {
2532 			skb2 = skb_clone(skb, GFP_ATOMIC);
2533 			if (skb2) {
2534 				skb2->dev = prev_dev;
2535 				netif_receive_skb(skb2);
2536 			}
2537 		}
2538 
2539 		prev_dev = sdata->dev;
2540 		sdata->dev->stats.rx_packets++;
2541 		sdata->dev->stats.rx_bytes += skb->len;
2542 	}
2543 
2544 	if (prev_dev) {
2545 		skb->dev = prev_dev;
2546 		netif_receive_skb(skb);
2547 		return;
2548 	}
2549 
2550  out_free_skb:
2551 	dev_kfree_skb(skb);
2552 }
2553 
2554 static void ieee80211_rx_handlers_result(struct ieee80211_rx_data *rx,
2555 					 ieee80211_rx_result res)
2556 {
2557 	switch (res) {
2558 	case RX_DROP_MONITOR:
2559 		I802_DEBUG_INC(rx->sdata->local->rx_handlers_drop);
2560 		if (rx->sta)
2561 			rx->sta->rx_dropped++;
2562 		/* fall through */
2563 	case RX_CONTINUE: {
2564 		struct ieee80211_rate *rate = NULL;
2565 		struct ieee80211_supported_band *sband;
2566 		struct ieee80211_rx_status *status;
2567 
2568 		status = IEEE80211_SKB_RXCB((rx->skb));
2569 
2570 		sband = rx->local->hw.wiphy->bands[status->band];
2571 		if (!(status->flag & RX_FLAG_HT))
2572 			rate = &sband->bitrates[status->rate_idx];
2573 
2574 		ieee80211_rx_cooked_monitor(rx, rate);
2575 		break;
2576 		}
2577 	case RX_DROP_UNUSABLE:
2578 		I802_DEBUG_INC(rx->sdata->local->rx_handlers_drop);
2579 		if (rx->sta)
2580 			rx->sta->rx_dropped++;
2581 		dev_kfree_skb(rx->skb);
2582 		break;
2583 	case RX_QUEUED:
2584 		I802_DEBUG_INC(rx->sdata->local->rx_handlers_queued);
2585 		break;
2586 	}
2587 }
2588 
2589 static void ieee80211_rx_handlers(struct ieee80211_rx_data *rx)
2590 {
2591 	ieee80211_rx_result res = RX_DROP_MONITOR;
2592 	struct sk_buff *skb;
2593 
2594 #define CALL_RXH(rxh)			\
2595 	do {				\
2596 		res = rxh(rx);		\
2597 		if (res != RX_CONTINUE)	\
2598 			goto rxh_next;  \
2599 	} while (0);
2600 
2601 	spin_lock(&rx->local->rx_skb_queue.lock);
2602 	if (rx->local->running_rx_handler)
2603 		goto unlock;
2604 
2605 	rx->local->running_rx_handler = true;
2606 
2607 	while ((skb = __skb_dequeue(&rx->local->rx_skb_queue))) {
2608 		spin_unlock(&rx->local->rx_skb_queue.lock);
2609 
2610 		/*
2611 		 * all the other fields are valid across frames
2612 		 * that belong to an aMPDU since they are on the
2613 		 * same TID from the same station
2614 		 */
2615 		rx->skb = skb;
2616 
2617 		CALL_RXH(ieee80211_rx_h_decrypt)
2618 		CALL_RXH(ieee80211_rx_h_check_more_data)
2619 		CALL_RXH(ieee80211_rx_h_uapsd_and_pspoll)
2620 		CALL_RXH(ieee80211_rx_h_sta_process)
2621 		CALL_RXH(ieee80211_rx_h_defragment)
2622 		CALL_RXH(ieee80211_rx_h_michael_mic_verify)
2623 		/* must be after MMIC verify so header is counted in MPDU mic */
2624 #ifdef CONFIG_MAC80211_MESH
2625 		if (ieee80211_vif_is_mesh(&rx->sdata->vif))
2626 			CALL_RXH(ieee80211_rx_h_mesh_fwding);
2627 #endif
2628 		CALL_RXH(ieee80211_rx_h_remove_qos_control)
2629 		CALL_RXH(ieee80211_rx_h_amsdu)
2630 		CALL_RXH(ieee80211_rx_h_data)
2631 		CALL_RXH(ieee80211_rx_h_ctrl);
2632 		CALL_RXH(ieee80211_rx_h_mgmt_check)
2633 		CALL_RXH(ieee80211_rx_h_action)
2634 		CALL_RXH(ieee80211_rx_h_userspace_mgmt)
2635 		CALL_RXH(ieee80211_rx_h_action_return)
2636 		CALL_RXH(ieee80211_rx_h_mgmt)
2637 
2638  rxh_next:
2639 		ieee80211_rx_handlers_result(rx, res);
2640 		spin_lock(&rx->local->rx_skb_queue.lock);
2641 #undef CALL_RXH
2642 	}
2643 
2644 	rx->local->running_rx_handler = false;
2645 
2646  unlock:
2647 	spin_unlock(&rx->local->rx_skb_queue.lock);
2648 }
2649 
2650 static void ieee80211_invoke_rx_handlers(struct ieee80211_rx_data *rx)
2651 {
2652 	ieee80211_rx_result res = RX_DROP_MONITOR;
2653 
2654 #define CALL_RXH(rxh)			\
2655 	do {				\
2656 		res = rxh(rx);		\
2657 		if (res != RX_CONTINUE)	\
2658 			goto rxh_next;  \
2659 	} while (0);
2660 
2661 	CALL_RXH(ieee80211_rx_h_passive_scan)
2662 	CALL_RXH(ieee80211_rx_h_check)
2663 
2664 	ieee80211_rx_reorder_ampdu(rx);
2665 
2666 	ieee80211_rx_handlers(rx);
2667 	return;
2668 
2669  rxh_next:
2670 	ieee80211_rx_handlers_result(rx, res);
2671 
2672 #undef CALL_RXH
2673 }
2674 
2675 /*
2676  * This function makes calls into the RX path, therefore
2677  * it has to be invoked under RCU read lock.
2678  */
2679 void ieee80211_release_reorder_timeout(struct sta_info *sta, int tid)
2680 {
2681 	struct ieee80211_rx_data rx = {
2682 		.sta = sta,
2683 		.sdata = sta->sdata,
2684 		.local = sta->local,
2685 		/* This is OK -- must be QoS data frame */
2686 		.security_idx = tid,
2687 		.seqno_idx = tid,
2688 		.flags = 0,
2689 	};
2690 	struct tid_ampdu_rx *tid_agg_rx;
2691 
2692 	tid_agg_rx = rcu_dereference(sta->ampdu_mlme.tid_rx[tid]);
2693 	if (!tid_agg_rx)
2694 		return;
2695 
2696 	spin_lock(&tid_agg_rx->reorder_lock);
2697 	ieee80211_sta_reorder_release(&sta->local->hw, tid_agg_rx);
2698 	spin_unlock(&tid_agg_rx->reorder_lock);
2699 
2700 	ieee80211_rx_handlers(&rx);
2701 }
2702 
2703 /* main receive path */
2704 
2705 static int prepare_for_handlers(struct ieee80211_rx_data *rx,
2706 				struct ieee80211_hdr *hdr)
2707 {
2708 	struct ieee80211_sub_if_data *sdata = rx->sdata;
2709 	struct sk_buff *skb = rx->skb;
2710 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
2711 	u8 *bssid = ieee80211_get_bssid(hdr, skb->len, sdata->vif.type);
2712 	int multicast = is_multicast_ether_addr(hdr->addr1);
2713 
2714 	switch (sdata->vif.type) {
2715 	case NL80211_IFTYPE_STATION:
2716 		if (!bssid && !sdata->u.mgd.use_4addr)
2717 			return 0;
2718 		if (!multicast &&
2719 		    compare_ether_addr(sdata->vif.addr, hdr->addr1) != 0) {
2720 			if (!(sdata->dev->flags & IFF_PROMISC) ||
2721 			    sdata->u.mgd.use_4addr)
2722 				return 0;
2723 			status->rx_flags &= ~IEEE80211_RX_RA_MATCH;
2724 		}
2725 		break;
2726 	case NL80211_IFTYPE_ADHOC:
2727 		if (!bssid)
2728 			return 0;
2729 		if (ieee80211_is_beacon(hdr->frame_control)) {
2730 			return 1;
2731 		}
2732 		else if (!ieee80211_bssid_match(bssid, sdata->u.ibss.bssid)) {
2733 			if (!(status->rx_flags & IEEE80211_RX_IN_SCAN))
2734 				return 0;
2735 			status->rx_flags &= ~IEEE80211_RX_RA_MATCH;
2736 		} else if (!multicast &&
2737 			   compare_ether_addr(sdata->vif.addr,
2738 					      hdr->addr1) != 0) {
2739 			if (!(sdata->dev->flags & IFF_PROMISC))
2740 				return 0;
2741 			status->rx_flags &= ~IEEE80211_RX_RA_MATCH;
2742 		} else if (!rx->sta) {
2743 			int rate_idx;
2744 			if (status->flag & RX_FLAG_HT)
2745 				rate_idx = 0; /* TODO: HT rates */
2746 			else
2747 				rate_idx = status->rate_idx;
2748 			rx->sta = ieee80211_ibss_add_sta(sdata, bssid,
2749 					hdr->addr2, BIT(rate_idx), GFP_ATOMIC);
2750 		}
2751 		break;
2752 	case NL80211_IFTYPE_MESH_POINT:
2753 		if (!multicast &&
2754 		    compare_ether_addr(sdata->vif.addr,
2755 				       hdr->addr1) != 0) {
2756 			if (!(sdata->dev->flags & IFF_PROMISC))
2757 				return 0;
2758 
2759 			status->rx_flags &= ~IEEE80211_RX_RA_MATCH;
2760 		}
2761 		break;
2762 	case NL80211_IFTYPE_AP_VLAN:
2763 	case NL80211_IFTYPE_AP:
2764 		if (!bssid) {
2765 			if (compare_ether_addr(sdata->vif.addr,
2766 					       hdr->addr1))
2767 				return 0;
2768 		} else if (!ieee80211_bssid_match(bssid,
2769 					sdata->vif.addr)) {
2770 			if (!(status->rx_flags & IEEE80211_RX_IN_SCAN) &&
2771 			    !ieee80211_is_beacon(hdr->frame_control) &&
2772 			    !(ieee80211_is_action(hdr->frame_control) &&
2773 			      sdata->vif.p2p))
2774 				return 0;
2775 			status->rx_flags &= ~IEEE80211_RX_RA_MATCH;
2776 		}
2777 		break;
2778 	case NL80211_IFTYPE_WDS:
2779 		if (bssid || !ieee80211_is_data(hdr->frame_control))
2780 			return 0;
2781 		if (compare_ether_addr(sdata->u.wds.remote_addr, hdr->addr2))
2782 			return 0;
2783 		break;
2784 	default:
2785 		/* should never get here */
2786 		WARN_ON(1);
2787 		break;
2788 	}
2789 
2790 	return 1;
2791 }
2792 
2793 /*
2794  * This function returns whether or not the SKB
2795  * was destined for RX processing or not, which,
2796  * if consume is true, is equivalent to whether
2797  * or not the skb was consumed.
2798  */
2799 static bool ieee80211_prepare_and_rx_handle(struct ieee80211_rx_data *rx,
2800 					    struct sk_buff *skb, bool consume)
2801 {
2802 	struct ieee80211_local *local = rx->local;
2803 	struct ieee80211_sub_if_data *sdata = rx->sdata;
2804 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
2805 	struct ieee80211_hdr *hdr = (void *)skb->data;
2806 	int prepares;
2807 
2808 	rx->skb = skb;
2809 	status->rx_flags |= IEEE80211_RX_RA_MATCH;
2810 	prepares = prepare_for_handlers(rx, hdr);
2811 
2812 	if (!prepares)
2813 		return false;
2814 
2815 	if (!consume) {
2816 		skb = skb_copy(skb, GFP_ATOMIC);
2817 		if (!skb) {
2818 			if (net_ratelimit())
2819 				wiphy_debug(local->hw.wiphy,
2820 					"failed to copy skb for %s\n",
2821 					sdata->name);
2822 			return true;
2823 		}
2824 
2825 		rx->skb = skb;
2826 	}
2827 
2828 	ieee80211_invoke_rx_handlers(rx);
2829 	return true;
2830 }
2831 
2832 /*
2833  * This is the actual Rx frames handler. as it blongs to Rx path it must
2834  * be called with rcu_read_lock protection.
2835  */
2836 static void __ieee80211_rx_handle_packet(struct ieee80211_hw *hw,
2837 					 struct sk_buff *skb)
2838 {
2839 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
2840 	struct ieee80211_local *local = hw_to_local(hw);
2841 	struct ieee80211_sub_if_data *sdata;
2842 	struct ieee80211_hdr *hdr;
2843 	__le16 fc;
2844 	struct ieee80211_rx_data rx;
2845 	struct ieee80211_sub_if_data *prev;
2846 	struct sta_info *sta, *tmp, *prev_sta;
2847 	int err = 0;
2848 
2849 	fc = ((struct ieee80211_hdr *)skb->data)->frame_control;
2850 	memset(&rx, 0, sizeof(rx));
2851 	rx.skb = skb;
2852 	rx.local = local;
2853 
2854 	if (ieee80211_is_data(fc) || ieee80211_is_mgmt(fc))
2855 		local->dot11ReceivedFragmentCount++;
2856 
2857 	if (unlikely(test_bit(SCAN_HW_SCANNING, &local->scanning) ||
2858 		     test_bit(SCAN_SW_SCANNING, &local->scanning)))
2859 		status->rx_flags |= IEEE80211_RX_IN_SCAN;
2860 
2861 	if (ieee80211_is_mgmt(fc))
2862 		err = skb_linearize(skb);
2863 	else
2864 		err = !pskb_may_pull(skb, ieee80211_hdrlen(fc));
2865 
2866 	if (err) {
2867 		dev_kfree_skb(skb);
2868 		return;
2869 	}
2870 
2871 	hdr = (struct ieee80211_hdr *)skb->data;
2872 	ieee80211_parse_qos(&rx);
2873 	ieee80211_verify_alignment(&rx);
2874 
2875 	if (ieee80211_is_data(fc)) {
2876 		prev_sta = NULL;
2877 
2878 		for_each_sta_info_rx(local, hdr->addr2, sta, tmp) {
2879 			if (!prev_sta) {
2880 				prev_sta = sta;
2881 				continue;
2882 			}
2883 
2884 			rx.sta = prev_sta;
2885 			rx.sdata = prev_sta->sdata;
2886 			ieee80211_prepare_and_rx_handle(&rx, skb, false);
2887 
2888 			prev_sta = sta;
2889 		}
2890 
2891 		if (prev_sta) {
2892 			rx.sta = prev_sta;
2893 			rx.sdata = prev_sta->sdata;
2894 
2895 			if (ieee80211_prepare_and_rx_handle(&rx, skb, true))
2896 				return;
2897 			goto out;
2898 		}
2899 	}
2900 
2901 	prev = NULL;
2902 
2903 	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
2904 		if (!ieee80211_sdata_running(sdata))
2905 			continue;
2906 
2907 		if (sdata->vif.type == NL80211_IFTYPE_MONITOR ||
2908 		    sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
2909 			continue;
2910 
2911 		/*
2912 		 * frame is destined for this interface, but if it's
2913 		 * not also for the previous one we handle that after
2914 		 * the loop to avoid copying the SKB once too much
2915 		 */
2916 
2917 		if (!prev) {
2918 			prev = sdata;
2919 			continue;
2920 		}
2921 
2922 		rx.sta = sta_info_get_bss_rx(prev, hdr->addr2);
2923 		rx.sdata = prev;
2924 		ieee80211_prepare_and_rx_handle(&rx, skb, false);
2925 
2926 		prev = sdata;
2927 	}
2928 
2929 	if (prev) {
2930 		rx.sta = sta_info_get_bss_rx(prev, hdr->addr2);
2931 		rx.sdata = prev;
2932 
2933 		if (ieee80211_prepare_and_rx_handle(&rx, skb, true))
2934 			return;
2935 	}
2936 
2937  out:
2938 	dev_kfree_skb(skb);
2939 }
2940 
2941 /*
2942  * This is the receive path handler. It is called by a low level driver when an
2943  * 802.11 MPDU is received from the hardware.
2944  */
2945 void ieee80211_rx(struct ieee80211_hw *hw, struct sk_buff *skb)
2946 {
2947 	struct ieee80211_local *local = hw_to_local(hw);
2948 	struct ieee80211_rate *rate = NULL;
2949 	struct ieee80211_supported_band *sband;
2950 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
2951 
2952 	WARN_ON_ONCE(softirq_count() == 0);
2953 
2954 	if (WARN_ON(status->band < 0 ||
2955 		    status->band >= IEEE80211_NUM_BANDS))
2956 		goto drop;
2957 
2958 	sband = local->hw.wiphy->bands[status->band];
2959 	if (WARN_ON(!sband))
2960 		goto drop;
2961 
2962 	/*
2963 	 * If we're suspending, it is possible although not too likely
2964 	 * that we'd be receiving frames after having already partially
2965 	 * quiesced the stack. We can't process such frames then since
2966 	 * that might, for example, cause stations to be added or other
2967 	 * driver callbacks be invoked.
2968 	 */
2969 	if (unlikely(local->quiescing || local->suspended))
2970 		goto drop;
2971 
2972 	/*
2973 	 * The same happens when we're not even started,
2974 	 * but that's worth a warning.
2975 	 */
2976 	if (WARN_ON(!local->started))
2977 		goto drop;
2978 
2979 	if (likely(!(status->flag & RX_FLAG_FAILED_PLCP_CRC))) {
2980 		/*
2981 		 * Validate the rate, unless a PLCP error means that
2982 		 * we probably can't have a valid rate here anyway.
2983 		 */
2984 
2985 		if (status->flag & RX_FLAG_HT) {
2986 			/*
2987 			 * rate_idx is MCS index, which can be [0-76]
2988 			 * as documented on:
2989 			 *
2990 			 * http://wireless.kernel.org/en/developers/Documentation/ieee80211/802.11n
2991 			 *
2992 			 * Anything else would be some sort of driver or
2993 			 * hardware error. The driver should catch hardware
2994 			 * errors.
2995 			 */
2996 			if (WARN((status->rate_idx < 0 ||
2997 				 status->rate_idx > 76),
2998 				 "Rate marked as an HT rate but passed "
2999 				 "status->rate_idx is not "
3000 				 "an MCS index [0-76]: %d (0x%02x)\n",
3001 				 status->rate_idx,
3002 				 status->rate_idx))
3003 				goto drop;
3004 		} else {
3005 			if (WARN_ON(status->rate_idx < 0 ||
3006 				    status->rate_idx >= sband->n_bitrates))
3007 				goto drop;
3008 			rate = &sband->bitrates[status->rate_idx];
3009 		}
3010 	}
3011 
3012 	status->rx_flags = 0;
3013 
3014 	/*
3015 	 * key references and virtual interfaces are protected using RCU
3016 	 * and this requires that we are in a read-side RCU section during
3017 	 * receive processing
3018 	 */
3019 	rcu_read_lock();
3020 
3021 	/*
3022 	 * Frames with failed FCS/PLCP checksum are not returned,
3023 	 * all other frames are returned without radiotap header
3024 	 * if it was previously present.
3025 	 * Also, frames with less than 16 bytes are dropped.
3026 	 */
3027 	skb = ieee80211_rx_monitor(local, skb, rate);
3028 	if (!skb) {
3029 		rcu_read_unlock();
3030 		return;
3031 	}
3032 
3033 	ieee80211_tpt_led_trig_rx(local,
3034 			((struct ieee80211_hdr *)skb->data)->frame_control,
3035 			skb->len);
3036 	__ieee80211_rx_handle_packet(hw, skb);
3037 
3038 	rcu_read_unlock();
3039 
3040 	return;
3041  drop:
3042 	kfree_skb(skb);
3043 }
3044 EXPORT_SYMBOL(ieee80211_rx);
3045 
3046 /* This is a version of the rx handler that can be called from hard irq
3047  * context. Post the skb on the queue and schedule the tasklet */
3048 void ieee80211_rx_irqsafe(struct ieee80211_hw *hw, struct sk_buff *skb)
3049 {
3050 	struct ieee80211_local *local = hw_to_local(hw);
3051 
3052 	BUILD_BUG_ON(sizeof(struct ieee80211_rx_status) > sizeof(skb->cb));
3053 
3054 	skb->pkt_type = IEEE80211_RX_MSG;
3055 	skb_queue_tail(&local->skb_queue, skb);
3056 	tasklet_schedule(&local->tasklet);
3057 }
3058 EXPORT_SYMBOL(ieee80211_rx_irqsafe);
3059