d9df819eef3b778ac76eacdaa54bf87c5dc0ed57
[linux-2.6.git] / net / mac80211 / rx.c
1 /*
2  * Copyright 2002-2005, Instant802 Networks, Inc.
3  * Copyright 2005-2006, Devicescape Software, Inc.
4  * Copyright 2006-2007  Jiri Benc <jbenc@suse.cz>
5  * Copyright 2007       Johannes Berg <johannes@sipsolutions.net>
6  *
7  * This program is free software; you can redistribute it and/or modify
8  * it under the terms of the GNU General Public License version 2 as
9  * published by the Free Software Foundation.
10  */
11
12 #include <linux/jiffies.h>
13 #include <linux/kernel.h>
14 #include <linux/skbuff.h>
15 #include <linux/netdevice.h>
16 #include <linux/etherdevice.h>
17 #include <linux/rcupdate.h>
18 #include <net/mac80211.h>
19 #include <net/ieee80211_radiotap.h>
20
21 #include "ieee80211_i.h"
22 #include "driver-ops.h"
23 #include "led.h"
24 #include "mesh.h"
25 #include "wep.h"
26 #include "wpa.h"
27 #include "tkip.h"
28 #include "wme.h"
29
30 static u8 ieee80211_sta_manage_reorder_buf(struct ieee80211_hw *hw,
31                                            struct tid_ampdu_rx *tid_agg_rx,
32                                            struct sk_buff *skb,
33                                            u16 mpdu_seq_num,
34                                            int bar_req);
35 /*
36  * monitor mode reception
37  *
38  * This function cleans up the SKB, i.e. it removes all the stuff
39  * only useful for monitoring.
40  */
41 static struct sk_buff *remove_monitor_info(struct ieee80211_local *local,
42                                            struct sk_buff *skb,
43                                            int rtap_len)
44 {
45         skb_pull(skb, rtap_len);
46
47         if (local->hw.flags & IEEE80211_HW_RX_INCLUDES_FCS) {
48                 if (likely(skb->len > FCS_LEN))
49                         skb_trim(skb, skb->len - FCS_LEN);
50                 else {
51                         /* driver bug */
52                         WARN_ON(1);
53                         dev_kfree_skb(skb);
54                         skb = NULL;
55                 }
56         }
57
58         return skb;
59 }
60
61 static inline int should_drop_frame(struct sk_buff *skb,
62                                     int present_fcs_len,
63                                     int radiotap_len)
64 {
65         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
66         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
67
68         if (status->flag & (RX_FLAG_FAILED_FCS_CRC | RX_FLAG_FAILED_PLCP_CRC))
69                 return 1;
70         if (unlikely(skb->len < 16 + present_fcs_len + radiotap_len))
71                 return 1;
72         if (ieee80211_is_ctl(hdr->frame_control) &&
73             !ieee80211_is_pspoll(hdr->frame_control) &&
74             !ieee80211_is_back_req(hdr->frame_control))
75                 return 1;
76         return 0;
77 }
78
79 static int
80 ieee80211_rx_radiotap_len(struct ieee80211_local *local,
81                           struct ieee80211_rx_status *status)
82 {
83         int len;
84
85         /* always present fields */
86         len = sizeof(struct ieee80211_radiotap_header) + 9;
87
88         if (status->flag & RX_FLAG_TSFT)
89                 len += 8;
90         if (local->hw.flags & IEEE80211_HW_SIGNAL_DBM)
91                 len += 1;
92         if (local->hw.flags & IEEE80211_HW_NOISE_DBM)
93                 len += 1;
94
95         if (len & 1) /* padding for RX_FLAGS if necessary */
96                 len++;
97
98         /* make sure radiotap starts at a naturally aligned address */
99         if (len % 8)
100                 len = roundup(len, 8);
101
102         return len;
103 }
104
105 /*
106  * ieee80211_add_rx_radiotap_header - add radiotap header
107  *
108  * add a radiotap header containing all the fields which the hardware provided.
109  */
110 static void
111 ieee80211_add_rx_radiotap_header(struct ieee80211_local *local,
112                                  struct sk_buff *skb,
113                                  struct ieee80211_rate *rate,
114                                  int rtap_len)
115 {
116         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
117         struct ieee80211_radiotap_header *rthdr;
118         unsigned char *pos;
119
120         rthdr = (struct ieee80211_radiotap_header *)skb_push(skb, rtap_len);
121         memset(rthdr, 0, rtap_len);
122
123         /* radiotap header, set always present flags */
124         rthdr->it_present =
125                 cpu_to_le32((1 << IEEE80211_RADIOTAP_FLAGS) |
126                             (1 << IEEE80211_RADIOTAP_CHANNEL) |
127                             (1 << IEEE80211_RADIOTAP_ANTENNA) |
128                             (1 << IEEE80211_RADIOTAP_RX_FLAGS));
129         rthdr->it_len = cpu_to_le16(rtap_len);
130
131         pos = (unsigned char *)(rthdr+1);
132
133         /* the order of the following fields is important */
134
135         /* IEEE80211_RADIOTAP_TSFT */
136         if (status->flag & RX_FLAG_TSFT) {
137                 *(__le64 *)pos = cpu_to_le64(status->mactime);
138                 rthdr->it_present |=
139                         cpu_to_le32(1 << IEEE80211_RADIOTAP_TSFT);
140                 pos += 8;
141         }
142
143         /* IEEE80211_RADIOTAP_FLAGS */
144         if (local->hw.flags & IEEE80211_HW_RX_INCLUDES_FCS)
145                 *pos |= IEEE80211_RADIOTAP_F_FCS;
146         if (status->flag & (RX_FLAG_FAILED_FCS_CRC | RX_FLAG_FAILED_PLCP_CRC))
147                 *pos |= IEEE80211_RADIOTAP_F_BADFCS;
148         if (status->flag & RX_FLAG_SHORTPRE)
149                 *pos |= IEEE80211_RADIOTAP_F_SHORTPRE;
150         pos++;
151
152         /* IEEE80211_RADIOTAP_RATE */
153         if (status->flag & RX_FLAG_HT) {
154                 /*
155                  * TODO: add following information into radiotap header once
156                  * suitable fields are defined for it:
157                  * - MCS index (status->rate_idx)
158                  * - HT40 (status->flag & RX_FLAG_40MHZ)
159                  * - short-GI (status->flag & RX_FLAG_SHORT_GI)
160                  */
161                 *pos = 0;
162         } else {
163                 rthdr->it_present |= cpu_to_le32(1 << IEEE80211_RADIOTAP_RATE);
164                 *pos = rate->bitrate / 5;
165         }
166         pos++;
167
168         /* IEEE80211_RADIOTAP_CHANNEL */
169         *(__le16 *)pos = cpu_to_le16(status->freq);
170         pos += 2;
171         if (status->band == IEEE80211_BAND_5GHZ)
172                 *(__le16 *)pos = cpu_to_le16(IEEE80211_CHAN_OFDM |
173                                              IEEE80211_CHAN_5GHZ);
174         else if (rate->flags & IEEE80211_RATE_ERP_G)
175                 *(__le16 *)pos = cpu_to_le16(IEEE80211_CHAN_OFDM |
176                                              IEEE80211_CHAN_2GHZ);
177         else
178                 *(__le16 *)pos = cpu_to_le16(IEEE80211_CHAN_CCK |
179                                              IEEE80211_CHAN_2GHZ);
180         pos += 2;
181
182         /* IEEE80211_RADIOTAP_DBM_ANTSIGNAL */
183         if (local->hw.flags & IEEE80211_HW_SIGNAL_DBM) {
184                 *pos = status->signal;
185                 rthdr->it_present |=
186                         cpu_to_le32(1 << IEEE80211_RADIOTAP_DBM_ANTSIGNAL);
187                 pos++;
188         }
189
190         /* IEEE80211_RADIOTAP_DBM_ANTNOISE */
191         if (local->hw.flags & IEEE80211_HW_NOISE_DBM) {
192                 *pos = status->noise;
193                 rthdr->it_present |=
194                         cpu_to_le32(1 << IEEE80211_RADIOTAP_DBM_ANTNOISE);
195                 pos++;
196         }
197
198         /* IEEE80211_RADIOTAP_LOCK_QUALITY is missing */
199
200         /* IEEE80211_RADIOTAP_ANTENNA */
201         *pos = status->antenna;
202         pos++;
203
204         /* IEEE80211_RADIOTAP_DB_ANTNOISE is not used */
205
206         /* IEEE80211_RADIOTAP_RX_FLAGS */
207         /* ensure 2 byte alignment for the 2 byte field as required */
208         if ((pos - (unsigned char *)rthdr) & 1)
209                 pos++;
210         if (status->flag & RX_FLAG_FAILED_PLCP_CRC)
211                 *(__le16 *)pos |= cpu_to_le16(IEEE80211_RADIOTAP_F_RX_BADPLCP);
212         pos += 2;
213 }
214
215 /*
216  * This function copies a received frame to all monitor interfaces and
217  * returns a cleaned-up SKB that no longer includes the FCS nor the
218  * radiotap header the driver might have added.
219  */
220 static struct sk_buff *
221 ieee80211_rx_monitor(struct ieee80211_local *local, struct sk_buff *origskb,
222                      struct ieee80211_rate *rate)
223 {
224         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(origskb);
225         struct ieee80211_sub_if_data *sdata;
226         int needed_headroom = 0;
227         struct sk_buff *skb, *skb2;
228         struct net_device *prev_dev = NULL;
229         int present_fcs_len = 0;
230         int rtap_len = 0;
231
232         /*
233          * First, we may need to make a copy of the skb because
234          *  (1) we need to modify it for radiotap (if not present), and
235          *  (2) the other RX handlers will modify the skb we got.
236          *
237          * We don't need to, of course, if we aren't going to return
238          * the SKB because it has a bad FCS/PLCP checksum.
239          */
240         if (status->flag & RX_FLAG_RADIOTAP)
241                 rtap_len = ieee80211_get_radiotap_len(origskb->data);
242         else
243                 /* room for the radiotap header based on driver features */
244                 needed_headroom = ieee80211_rx_radiotap_len(local, status);
245
246         if (local->hw.flags & IEEE80211_HW_RX_INCLUDES_FCS)
247                 present_fcs_len = FCS_LEN;
248
249         if (!local->monitors) {
250                 if (should_drop_frame(origskb, present_fcs_len, rtap_len)) {
251                         dev_kfree_skb(origskb);
252                         return NULL;
253                 }
254
255                 return remove_monitor_info(local, origskb, rtap_len);
256         }
257
258         if (should_drop_frame(origskb, present_fcs_len, rtap_len)) {
259                 /* only need to expand headroom if necessary */
260                 skb = origskb;
261                 origskb = NULL;
262
263                 /*
264                  * This shouldn't trigger often because most devices have an
265                  * RX header they pull before we get here, and that should
266                  * be big enough for our radiotap information. We should
267                  * probably export the length to drivers so that we can have
268                  * them allocate enough headroom to start with.
269                  */
270                 if (skb_headroom(skb) < needed_headroom &&
271                     pskb_expand_head(skb, needed_headroom, 0, GFP_ATOMIC)) {
272                         dev_kfree_skb(skb);
273                         return NULL;
274                 }
275         } else {
276                 /*
277                  * Need to make a copy and possibly remove radiotap header
278                  * and FCS from the original.
279                  */
280                 skb = skb_copy_expand(origskb, needed_headroom, 0, GFP_ATOMIC);
281
282                 origskb = remove_monitor_info(local, origskb, rtap_len);
283
284                 if (!skb)
285                         return origskb;
286         }
287
288         /* if necessary, prepend radiotap information */
289         if (!(status->flag & RX_FLAG_RADIOTAP))
290                 ieee80211_add_rx_radiotap_header(local, skb, rate,
291                                                  needed_headroom);
292
293         skb_reset_mac_header(skb);
294         skb->ip_summed = CHECKSUM_UNNECESSARY;
295         skb->pkt_type = PACKET_OTHERHOST;
296         skb->protocol = htons(ETH_P_802_2);
297
298         list_for_each_entry_rcu(sdata, &local->interfaces, list) {
299                 if (!netif_running(sdata->dev))
300                         continue;
301
302                 if (sdata->vif.type != NL80211_IFTYPE_MONITOR)
303                         continue;
304
305                 if (sdata->u.mntr_flags & MONITOR_FLAG_COOK_FRAMES)
306                         continue;
307
308                 if (prev_dev) {
309                         skb2 = skb_clone(skb, GFP_ATOMIC);
310                         if (skb2) {
311                                 skb2->dev = prev_dev;
312                                 netif_rx(skb2);
313                         }
314                 }
315
316                 prev_dev = sdata->dev;
317                 sdata->dev->stats.rx_packets++;
318                 sdata->dev->stats.rx_bytes += skb->len;
319         }
320
321         if (prev_dev) {
322                 skb->dev = prev_dev;
323                 netif_rx(skb);
324         } else
325                 dev_kfree_skb(skb);
326
327         return origskb;
328 }
329
330
331 static void ieee80211_parse_qos(struct ieee80211_rx_data *rx)
332 {
333         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
334         int tid;
335
336         /* does the frame have a qos control field? */
337         if (ieee80211_is_data_qos(hdr->frame_control)) {
338                 u8 *qc = ieee80211_get_qos_ctl(hdr);
339                 /* frame has qos control */
340                 tid = *qc & IEEE80211_QOS_CTL_TID_MASK;
341                 if (*qc & IEEE80211_QOS_CONTROL_A_MSDU_PRESENT)
342                         rx->flags |= IEEE80211_RX_AMSDU;
343                 else
344                         rx->flags &= ~IEEE80211_RX_AMSDU;
345         } else {
346                 /*
347                  * IEEE 802.11-2007, 7.1.3.4.1 ("Sequence Number field"):
348                  *
349                  *      Sequence numbers for management frames, QoS data
350                  *      frames with a broadcast/multicast address in the
351                  *      Address 1 field, and all non-QoS data frames sent
352                  *      by QoS STAs are assigned using an additional single
353                  *      modulo-4096 counter, [...]
354                  *
355                  * We also use that counter for non-QoS STAs.
356                  */
357                 tid = NUM_RX_DATA_QUEUES - 1;
358         }
359
360         rx->queue = tid;
361         /* Set skb->priority to 1d tag if highest order bit of TID is not set.
362          * For now, set skb->priority to 0 for other cases. */
363         rx->skb->priority = (tid > 7) ? 0 : tid;
364 }
365
366 /**
367  * DOC: Packet alignment
368  *
369  * Drivers always need to pass packets that are aligned to two-byte boundaries
370  * to the stack.
371  *
372  * Additionally, should, if possible, align the payload data in a way that
373  * guarantees that the contained IP header is aligned to a four-byte
374  * boundary. In the case of regular frames, this simply means aligning the
375  * payload to a four-byte boundary (because either the IP header is directly
376  * contained, or IV/RFC1042 headers that have a length divisible by four are
377  * in front of it).
378  *
379  * With A-MSDU frames, however, the payload data address must yield two modulo
380  * four because there are 14-byte 802.3 headers within the A-MSDU frames that
381  * push the IP header further back to a multiple of four again. Thankfully, the
382  * specs were sane enough this time around to require padding each A-MSDU
383  * subframe to a length that is a multiple of four.
384  *
385  * Padding like Atheros hardware adds which is inbetween the 802.11 header and
386  * the payload is not supported, the driver is required to move the 802.11
387  * header to be directly in front of the payload in that case.
388  */
389 static void ieee80211_verify_alignment(struct ieee80211_rx_data *rx)
390 {
391         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
392         int hdrlen;
393
394 #ifndef CONFIG_MAC80211_DEBUG_PACKET_ALIGNMENT
395         return;
396 #endif
397
398         if (WARN_ONCE((unsigned long)rx->skb->data & 1,
399                       "unaligned packet at 0x%p\n", rx->skb->data))
400                 return;
401
402         if (!ieee80211_is_data_present(hdr->frame_control))
403                 return;
404
405         hdrlen = ieee80211_hdrlen(hdr->frame_control);
406         if (rx->flags & IEEE80211_RX_AMSDU)
407                 hdrlen += ETH_HLEN;
408         WARN_ONCE(((unsigned long)(rx->skb->data + hdrlen)) & 3,
409                   "unaligned IP payload at 0x%p\n", rx->skb->data + hdrlen);
410 }
411
412
413 /* rx handlers */
414
415 static ieee80211_rx_result debug_noinline
416 ieee80211_rx_h_passive_scan(struct ieee80211_rx_data *rx)
417 {
418         struct ieee80211_local *local = rx->local;
419         struct sk_buff *skb = rx->skb;
420
421         if (unlikely(local->hw_scanning))
422                 return ieee80211_scan_rx(rx->sdata, skb);
423
424         if (unlikely(local->sw_scanning)) {
425                 /* drop all the other packets during a software scan anyway */
426                 if (ieee80211_scan_rx(rx->sdata, skb) != RX_QUEUED)
427                         dev_kfree_skb(skb);
428                 return RX_QUEUED;
429         }
430
431         if (unlikely(rx->flags & IEEE80211_RX_IN_SCAN)) {
432                 /* scanning finished during invoking of handlers */
433                 I802_DEBUG_INC(local->rx_handlers_drop_passive_scan);
434                 return RX_DROP_UNUSABLE;
435         }
436
437         return RX_CONTINUE;
438 }
439
440
441 static int ieee80211_is_unicast_robust_mgmt_frame(struct sk_buff *skb)
442 {
443         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
444
445         if (skb->len < 24 || is_multicast_ether_addr(hdr->addr1))
446                 return 0;
447
448         return ieee80211_is_robust_mgmt_frame(hdr);
449 }
450
451
452 static int ieee80211_is_multicast_robust_mgmt_frame(struct sk_buff *skb)
453 {
454         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
455
456         if (skb->len < 24 || !is_multicast_ether_addr(hdr->addr1))
457                 return 0;
458
459         return ieee80211_is_robust_mgmt_frame(hdr);
460 }
461
462
463 /* Get the BIP key index from MMIE; return -1 if this is not a BIP frame */
464 static int ieee80211_get_mmie_keyidx(struct sk_buff *skb)
465 {
466         struct ieee80211_mgmt *hdr = (struct ieee80211_mgmt *) skb->data;
467         struct ieee80211_mmie *mmie;
468
469         if (skb->len < 24 + sizeof(*mmie) ||
470             !is_multicast_ether_addr(hdr->da))
471                 return -1;
472
473         if (!ieee80211_is_robust_mgmt_frame((struct ieee80211_hdr *) hdr))
474                 return -1; /* not a robust management frame */
475
476         mmie = (struct ieee80211_mmie *)
477                 (skb->data + skb->len - sizeof(*mmie));
478         if (mmie->element_id != WLAN_EID_MMIE ||
479             mmie->length != sizeof(*mmie) - 2)
480                 return -1;
481
482         return le16_to_cpu(mmie->key_id);
483 }
484
485
486 static ieee80211_rx_result
487 ieee80211_rx_mesh_check(struct ieee80211_rx_data *rx)
488 {
489         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
490         unsigned int hdrlen = ieee80211_hdrlen(hdr->frame_control);
491
492         if (ieee80211_is_data(hdr->frame_control)) {
493                 if (!ieee80211_has_a4(hdr->frame_control))
494                         return RX_DROP_MONITOR;
495                 if (memcmp(hdr->addr4, rx->dev->dev_addr, ETH_ALEN) == 0)
496                         return RX_DROP_MONITOR;
497         }
498
499         /* If there is not an established peer link and this is not a peer link
500          * establisment frame, beacon or probe, drop the frame.
501          */
502
503         if (!rx->sta || sta_plink_state(rx->sta) != PLINK_ESTAB) {
504                 struct ieee80211_mgmt *mgmt;
505
506                 if (!ieee80211_is_mgmt(hdr->frame_control))
507                         return RX_DROP_MONITOR;
508
509                 if (ieee80211_is_action(hdr->frame_control)) {
510                         mgmt = (struct ieee80211_mgmt *)hdr;
511                         if (mgmt->u.action.category != PLINK_CATEGORY)
512                                 return RX_DROP_MONITOR;
513                         return RX_CONTINUE;
514                 }
515
516                 if (ieee80211_is_probe_req(hdr->frame_control) ||
517                     ieee80211_is_probe_resp(hdr->frame_control) ||
518                     ieee80211_is_beacon(hdr->frame_control))
519                         return RX_CONTINUE;
520
521                 return RX_DROP_MONITOR;
522
523         }
524
525 #define msh_h_get(h, l) ((struct ieee80211s_hdr *) ((u8 *)h + l))
526
527         if (ieee80211_is_data(hdr->frame_control) &&
528             is_multicast_ether_addr(hdr->addr1) &&
529             mesh_rmc_check(hdr->addr4, msh_h_get(hdr, hdrlen), rx->sdata))
530                 return RX_DROP_MONITOR;
531 #undef msh_h_get
532
533         return RX_CONTINUE;
534 }
535
536
537 static ieee80211_rx_result debug_noinline
538 ieee80211_rx_h_check(struct ieee80211_rx_data *rx)
539 {
540         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
541
542         /* Drop duplicate 802.11 retransmissions (IEEE 802.11 Chap. 9.2.9) */
543         if (rx->sta && !is_multicast_ether_addr(hdr->addr1)) {
544                 if (unlikely(ieee80211_has_retry(hdr->frame_control) &&
545                              rx->sta->last_seq_ctrl[rx->queue] ==
546                              hdr->seq_ctrl)) {
547                         if (rx->flags & IEEE80211_RX_RA_MATCH) {
548                                 rx->local->dot11FrameDuplicateCount++;
549                                 rx->sta->num_duplicates++;
550                         }
551                         return RX_DROP_MONITOR;
552                 } else
553                         rx->sta->last_seq_ctrl[rx->queue] = hdr->seq_ctrl;
554         }
555
556         if (unlikely(rx->skb->len < 16)) {
557                 I802_DEBUG_INC(rx->local->rx_handlers_drop_short);
558                 return RX_DROP_MONITOR;
559         }
560
561         /* Drop disallowed frame classes based on STA auth/assoc state;
562          * IEEE 802.11, Chap 5.5.
563          *
564          * mac80211 filters only based on association state, i.e. it drops
565          * Class 3 frames from not associated stations. hostapd sends
566          * deauth/disassoc frames when needed. In addition, hostapd is
567          * responsible for filtering on both auth and assoc states.
568          */
569
570         if (ieee80211_vif_is_mesh(&rx->sdata->vif))
571                 return ieee80211_rx_mesh_check(rx);
572
573         if (unlikely((ieee80211_is_data(hdr->frame_control) ||
574                       ieee80211_is_pspoll(hdr->frame_control)) &&
575                      rx->sdata->vif.type != NL80211_IFTYPE_ADHOC &&
576                      (!rx->sta || !test_sta_flags(rx->sta, WLAN_STA_ASSOC)))) {
577                 if ((!ieee80211_has_fromds(hdr->frame_control) &&
578                      !ieee80211_has_tods(hdr->frame_control) &&
579                      ieee80211_is_data(hdr->frame_control)) ||
580                     !(rx->flags & IEEE80211_RX_RA_MATCH)) {
581                         /* Drop IBSS frames and frames for other hosts
582                          * silently. */
583                         return RX_DROP_MONITOR;
584                 }
585
586                 return RX_DROP_MONITOR;
587         }
588
589         return RX_CONTINUE;
590 }
591
592
593 static ieee80211_rx_result debug_noinline
594 ieee80211_rx_h_decrypt(struct ieee80211_rx_data *rx)
595 {
596         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
597         int keyidx;
598         int hdrlen;
599         ieee80211_rx_result result = RX_DROP_UNUSABLE;
600         struct ieee80211_key *stakey = NULL;
601         int mmie_keyidx = -1;
602
603         /*
604          * Key selection 101
605          *
606          * There are four types of keys:
607          *  - GTK (group keys)
608          *  - IGTK (group keys for management frames)
609          *  - PTK (pairwise keys)
610          *  - STK (station-to-station pairwise keys)
611          *
612          * When selecting a key, we have to distinguish between multicast
613          * (including broadcast) and unicast frames, the latter can only
614          * use PTKs and STKs while the former always use GTKs and IGTKs.
615          * Unless, of course, actual WEP keys ("pre-RSNA") are used, then
616          * unicast frames can also use key indices like GTKs. Hence, if we
617          * don't have a PTK/STK we check the key index for a WEP key.
618          *
619          * Note that in a regular BSS, multicast frames are sent by the
620          * AP only, associated stations unicast the frame to the AP first
621          * which then multicasts it on their behalf.
622          *
623          * There is also a slight problem in IBSS mode: GTKs are negotiated
624          * with each station, that is something we don't currently handle.
625          * The spec seems to expect that one negotiates the same key with
626          * every station but there's no such requirement; VLANs could be
627          * possible.
628          */
629
630         /*
631          * No point in finding a key and decrypting if the frame is neither
632          * addressed to us nor a multicast frame.
633          */
634         if (!(rx->flags & IEEE80211_RX_RA_MATCH))
635                 return RX_CONTINUE;
636
637         if (rx->sta)
638                 stakey = rcu_dereference(rx->sta->key);
639
640         if (!ieee80211_has_protected(hdr->frame_control))
641                 mmie_keyidx = ieee80211_get_mmie_keyidx(rx->skb);
642
643         if (!is_multicast_ether_addr(hdr->addr1) && stakey) {
644                 rx->key = stakey;
645                 /* Skip decryption if the frame is not protected. */
646                 if (!ieee80211_has_protected(hdr->frame_control))
647                         return RX_CONTINUE;
648         } else if (mmie_keyidx >= 0) {
649                 /* Broadcast/multicast robust management frame / BIP */
650                 if ((rx->status->flag & RX_FLAG_DECRYPTED) &&
651                     (rx->status->flag & RX_FLAG_IV_STRIPPED))
652                         return RX_CONTINUE;
653
654                 if (mmie_keyidx < NUM_DEFAULT_KEYS ||
655                     mmie_keyidx >= NUM_DEFAULT_KEYS + NUM_DEFAULT_MGMT_KEYS)
656                         return RX_DROP_MONITOR; /* unexpected BIP keyidx */
657                 rx->key = rcu_dereference(rx->sdata->keys[mmie_keyidx]);
658         } else if (!ieee80211_has_protected(hdr->frame_control)) {
659                 /*
660                  * The frame was not protected, so skip decryption. However, we
661                  * need to set rx->key if there is a key that could have been
662                  * used so that the frame may be dropped if encryption would
663                  * have been expected.
664                  */
665                 struct ieee80211_key *key = NULL;
666                 if (ieee80211_is_mgmt(hdr->frame_control) &&
667                     is_multicast_ether_addr(hdr->addr1) &&
668                     (key = rcu_dereference(rx->sdata->default_mgmt_key)))
669                         rx->key = key;
670                 else if ((key = rcu_dereference(rx->sdata->default_key)))
671                         rx->key = key;
672                 return RX_CONTINUE;
673         } else {
674                 /*
675                  * The device doesn't give us the IV so we won't be
676                  * able to look up the key. That's ok though, we
677                  * don't need to decrypt the frame, we just won't
678                  * be able to keep statistics accurate.
679                  * Except for key threshold notifications, should
680                  * we somehow allow the driver to tell us which key
681                  * the hardware used if this flag is set?
682                  */
683                 if ((rx->status->flag & RX_FLAG_DECRYPTED) &&
684                     (rx->status->flag & RX_FLAG_IV_STRIPPED))
685                         return RX_CONTINUE;
686
687                 hdrlen = ieee80211_hdrlen(hdr->frame_control);
688
689                 if (rx->skb->len < 8 + hdrlen)
690                         return RX_DROP_UNUSABLE; /* TODO: count this? */
691
692                 /*
693                  * no need to call ieee80211_wep_get_keyidx,
694                  * it verifies a bunch of things we've done already
695                  */
696                 keyidx = rx->skb->data[hdrlen + 3] >> 6;
697
698                 rx->key = rcu_dereference(rx->sdata->keys[keyidx]);
699
700                 /*
701                  * RSNA-protected unicast frames should always be sent with
702                  * pairwise or station-to-station keys, but for WEP we allow
703                  * using a key index as well.
704                  */
705                 if (rx->key && rx->key->conf.alg != ALG_WEP &&
706                     !is_multicast_ether_addr(hdr->addr1))
707                         rx->key = NULL;
708         }
709
710         if (rx->key) {
711                 rx->key->tx_rx_count++;
712                 /* TODO: add threshold stuff again */
713         } else {
714                 return RX_DROP_MONITOR;
715         }
716
717         /* Check for weak IVs if possible */
718         if (rx->sta && rx->key->conf.alg == ALG_WEP &&
719             ieee80211_is_data(hdr->frame_control) &&
720             (!(rx->status->flag & RX_FLAG_IV_STRIPPED) ||
721              !(rx->status->flag & RX_FLAG_DECRYPTED)) &&
722             ieee80211_wep_is_weak_iv(rx->skb, rx->key))
723                 rx->sta->wep_weak_iv_count++;
724
725         switch (rx->key->conf.alg) {
726         case ALG_WEP:
727                 result = ieee80211_crypto_wep_decrypt(rx);
728                 break;
729         case ALG_TKIP:
730                 result = ieee80211_crypto_tkip_decrypt(rx);
731                 break;
732         case ALG_CCMP:
733                 result = ieee80211_crypto_ccmp_decrypt(rx);
734                 break;
735         case ALG_AES_CMAC:
736                 result = ieee80211_crypto_aes_cmac_decrypt(rx);
737                 break;
738         }
739
740         /* either the frame has been decrypted or will be dropped */
741         rx->status->flag |= RX_FLAG_DECRYPTED;
742
743         return result;
744 }
745
746 static ieee80211_rx_result debug_noinline
747 ieee80211_rx_h_check_more_data(struct ieee80211_rx_data *rx)
748 {
749         struct ieee80211_local *local;
750         struct ieee80211_hdr *hdr;
751         struct sk_buff *skb;
752
753         local = rx->local;
754         skb = rx->skb;
755         hdr = (struct ieee80211_hdr *) skb->data;
756
757         if (!local->pspolling)
758                 return RX_CONTINUE;
759
760         if (!ieee80211_has_fromds(hdr->frame_control))
761                 /* this is not from AP */
762                 return RX_CONTINUE;
763
764         if (!ieee80211_is_data(hdr->frame_control))
765                 return RX_CONTINUE;
766
767         if (!ieee80211_has_moredata(hdr->frame_control)) {
768                 /* AP has no more frames buffered for us */
769                 local->pspolling = false;
770                 return RX_CONTINUE;
771         }
772
773         /* more data bit is set, let's request a new frame from the AP */
774         ieee80211_send_pspoll(local, rx->sdata);
775
776         return RX_CONTINUE;
777 }
778
779 static void ap_sta_ps_start(struct sta_info *sta)
780 {
781         struct ieee80211_sub_if_data *sdata = sta->sdata;
782         struct ieee80211_local *local = sdata->local;
783
784         atomic_inc(&sdata->bss->num_sta_ps);
785         set_and_clear_sta_flags(sta, WLAN_STA_PS, WLAN_STA_PSPOLL);
786         drv_sta_notify(local, &sdata->vif, STA_NOTIFY_SLEEP, &sta->sta);
787 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
788         printk(KERN_DEBUG "%s: STA %pM aid %d enters power save mode\n",
789                sdata->dev->name, sta->sta.addr, sta->sta.aid);
790 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
791 }
792
793 static int ap_sta_ps_end(struct sta_info *sta)
794 {
795         struct ieee80211_sub_if_data *sdata = sta->sdata;
796         struct ieee80211_local *local = sdata->local;
797         int sent, buffered;
798
799         atomic_dec(&sdata->bss->num_sta_ps);
800
801         clear_sta_flags(sta, WLAN_STA_PS | WLAN_STA_PSPOLL);
802         drv_sta_notify(local, &sdata->vif, STA_NOTIFY_AWAKE, &sta->sta);
803
804         if (!skb_queue_empty(&sta->ps_tx_buf))
805                 sta_info_clear_tim_bit(sta);
806
807 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
808         printk(KERN_DEBUG "%s: STA %pM aid %d exits power save mode\n",
809                sdata->dev->name, sta->sta.addr, sta->sta.aid);
810 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
811
812         /* Send all buffered frames to the station */
813         sent = ieee80211_add_pending_skbs(local, &sta->tx_filtered);
814         buffered = ieee80211_add_pending_skbs(local, &sta->ps_tx_buf);
815         sent += buffered;
816         local->total_ps_buffered -= buffered;
817
818 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
819         printk(KERN_DEBUG "%s: STA %pM aid %d sending %d filtered/%d PS frames "
820                "since STA not sleeping anymore\n", sdata->dev->name,
821                sta->sta.addr, sta->sta.aid, sent - buffered, buffered);
822 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
823
824         return sent;
825 }
826
827 static ieee80211_rx_result debug_noinline
828 ieee80211_rx_h_sta_process(struct ieee80211_rx_data *rx)
829 {
830         struct sta_info *sta = rx->sta;
831         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
832
833         if (!sta)
834                 return RX_CONTINUE;
835
836         /*
837          * Update last_rx only for IBSS packets which are for the current
838          * BSSID to avoid keeping the current IBSS network alive in cases
839          * where other STAs start using different BSSID.
840          */
841         if (rx->sdata->vif.type == NL80211_IFTYPE_ADHOC) {
842                 u8 *bssid = ieee80211_get_bssid(hdr, rx->skb->len,
843                                                 NL80211_IFTYPE_ADHOC);
844                 if (compare_ether_addr(bssid, rx->sdata->u.ibss.bssid) == 0)
845                         sta->last_rx = jiffies;
846         } else if (!is_multicast_ether_addr(hdr->addr1)) {
847                 /*
848                  * Mesh beacons will update last_rx when if they are found to
849                  * match the current local configuration when processed.
850                  */
851                 sta->last_rx = jiffies;
852         }
853
854         if (!(rx->flags & IEEE80211_RX_RA_MATCH))
855                 return RX_CONTINUE;
856
857         if (rx->sdata->vif.type == NL80211_IFTYPE_STATION)
858                 ieee80211_sta_rx_notify(rx->sdata, hdr);
859
860         sta->rx_fragments++;
861         sta->rx_bytes += rx->skb->len;
862         sta->last_signal = rx->status->signal;
863         sta->last_qual = rx->status->qual;
864         sta->last_noise = rx->status->noise;
865
866         /*
867          * Change STA power saving mode only at the end of a frame
868          * exchange sequence.
869          */
870         if (!ieee80211_has_morefrags(hdr->frame_control) &&
871             (rx->sdata->vif.type == NL80211_IFTYPE_AP ||
872              rx->sdata->vif.type == NL80211_IFTYPE_AP_VLAN)) {
873                 if (test_sta_flags(sta, WLAN_STA_PS)) {
874                         /*
875                          * Ignore doze->wake transitions that are
876                          * indicated by non-data frames, the standard
877                          * is unclear here, but for example going to
878                          * PS mode and then scanning would cause a
879                          * doze->wake transition for the probe request,
880                          * and that is clearly undesirable.
881                          */
882                         if (ieee80211_is_data(hdr->frame_control) &&
883                             !ieee80211_has_pm(hdr->frame_control))
884                                 rx->sent_ps_buffered += ap_sta_ps_end(sta);
885                 } else {
886                         if (ieee80211_has_pm(hdr->frame_control))
887                                 ap_sta_ps_start(sta);
888                 }
889         }
890
891         /* Drop data::nullfunc frames silently, since they are used only to
892          * control station power saving mode. */
893         if (ieee80211_is_nullfunc(hdr->frame_control)) {
894                 I802_DEBUG_INC(rx->local->rx_handlers_drop_nullfunc);
895                 /* Update counter and free packet here to avoid counting this
896                  * as a dropped packed. */
897                 sta->rx_packets++;
898                 dev_kfree_skb(rx->skb);
899                 return RX_QUEUED;
900         }
901
902         return RX_CONTINUE;
903 } /* ieee80211_rx_h_sta_process */
904
905 static inline struct ieee80211_fragment_entry *
906 ieee80211_reassemble_add(struct ieee80211_sub_if_data *sdata,
907                          unsigned int frag, unsigned int seq, int rx_queue,
908                          struct sk_buff **skb)
909 {
910         struct ieee80211_fragment_entry *entry;
911         int idx;
912
913         idx = sdata->fragment_next;
914         entry = &sdata->fragments[sdata->fragment_next++];
915         if (sdata->fragment_next >= IEEE80211_FRAGMENT_MAX)
916                 sdata->fragment_next = 0;
917
918         if (!skb_queue_empty(&entry->skb_list)) {
919 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG
920                 struct ieee80211_hdr *hdr =
921                         (struct ieee80211_hdr *) entry->skb_list.next->data;
922                 printk(KERN_DEBUG "%s: RX reassembly removed oldest "
923                        "fragment entry (idx=%d age=%lu seq=%d last_frag=%d "
924                        "addr1=%pM addr2=%pM\n",
925                        sdata->dev->name, idx,
926                        jiffies - entry->first_frag_time, entry->seq,
927                        entry->last_frag, hdr->addr1, hdr->addr2);
928 #endif
929                 __skb_queue_purge(&entry->skb_list);
930         }
931
932         __skb_queue_tail(&entry->skb_list, *skb); /* no need for locking */
933         *skb = NULL;
934         entry->first_frag_time = jiffies;
935         entry->seq = seq;
936         entry->rx_queue = rx_queue;
937         entry->last_frag = frag;
938         entry->ccmp = 0;
939         entry->extra_len = 0;
940
941         return entry;
942 }
943
944 static inline struct ieee80211_fragment_entry *
945 ieee80211_reassemble_find(struct ieee80211_sub_if_data *sdata,
946                           unsigned int frag, unsigned int seq,
947                           int rx_queue, struct ieee80211_hdr *hdr)
948 {
949         struct ieee80211_fragment_entry *entry;
950         int i, idx;
951
952         idx = sdata->fragment_next;
953         for (i = 0; i < IEEE80211_FRAGMENT_MAX; i++) {
954                 struct ieee80211_hdr *f_hdr;
955
956                 idx--;
957                 if (idx < 0)
958                         idx = IEEE80211_FRAGMENT_MAX - 1;
959
960                 entry = &sdata->fragments[idx];
961                 if (skb_queue_empty(&entry->skb_list) || entry->seq != seq ||
962                     entry->rx_queue != rx_queue ||
963                     entry->last_frag + 1 != frag)
964                         continue;
965
966                 f_hdr = (struct ieee80211_hdr *)entry->skb_list.next->data;
967
968                 /*
969                  * Check ftype and addresses are equal, else check next fragment
970                  */
971                 if (((hdr->frame_control ^ f_hdr->frame_control) &
972                      cpu_to_le16(IEEE80211_FCTL_FTYPE)) ||
973                     compare_ether_addr(hdr->addr1, f_hdr->addr1) != 0 ||
974                     compare_ether_addr(hdr->addr2, f_hdr->addr2) != 0)
975                         continue;
976
977                 if (time_after(jiffies, entry->first_frag_time + 2 * HZ)) {
978                         __skb_queue_purge(&entry->skb_list);
979                         continue;
980                 }
981                 return entry;
982         }
983
984         return NULL;
985 }
986
987 static ieee80211_rx_result debug_noinline
988 ieee80211_rx_h_defragment(struct ieee80211_rx_data *rx)
989 {
990         struct ieee80211_hdr *hdr;
991         u16 sc;
992         __le16 fc;
993         unsigned int frag, seq;
994         struct ieee80211_fragment_entry *entry;
995         struct sk_buff *skb;
996
997         hdr = (struct ieee80211_hdr *)rx->skb->data;
998         fc = hdr->frame_control;
999         sc = le16_to_cpu(hdr->seq_ctrl);
1000         frag = sc & IEEE80211_SCTL_FRAG;
1001
1002         if (likely((!ieee80211_has_morefrags(fc) && frag == 0) ||
1003                    (rx->skb)->len < 24 ||
1004                    is_multicast_ether_addr(hdr->addr1))) {
1005                 /* not fragmented */
1006                 goto out;
1007         }
1008         I802_DEBUG_INC(rx->local->rx_handlers_fragments);
1009
1010         seq = (sc & IEEE80211_SCTL_SEQ) >> 4;
1011
1012         if (frag == 0) {
1013                 /* This is the first fragment of a new frame. */
1014                 entry = ieee80211_reassemble_add(rx->sdata, frag, seq,
1015                                                  rx->queue, &(rx->skb));
1016                 if (rx->key && rx->key->conf.alg == ALG_CCMP &&
1017                     ieee80211_has_protected(fc)) {
1018                         /* Store CCMP PN so that we can verify that the next
1019                          * fragment has a sequential PN value. */
1020                         entry->ccmp = 1;
1021                         memcpy(entry->last_pn,
1022                                rx->key->u.ccmp.rx_pn[rx->queue],
1023                                CCMP_PN_LEN);
1024                 }
1025                 return RX_QUEUED;
1026         }
1027
1028         /* This is a fragment for a frame that should already be pending in
1029          * fragment cache. Add this fragment to the end of the pending entry.
1030          */
1031         entry = ieee80211_reassemble_find(rx->sdata, frag, seq, rx->queue, hdr);
1032         if (!entry) {
1033                 I802_DEBUG_INC(rx->local->rx_handlers_drop_defrag);
1034                 return RX_DROP_MONITOR;
1035         }
1036
1037         /* Verify that MPDUs within one MSDU have sequential PN values.
1038          * (IEEE 802.11i, 8.3.3.4.5) */
1039         if (entry->ccmp) {
1040                 int i;
1041                 u8 pn[CCMP_PN_LEN], *rpn;
1042                 if (!rx->key || rx->key->conf.alg != ALG_CCMP)
1043                         return RX_DROP_UNUSABLE;
1044                 memcpy(pn, entry->last_pn, CCMP_PN_LEN);
1045                 for (i = CCMP_PN_LEN - 1; i >= 0; i--) {
1046                         pn[i]++;
1047                         if (pn[i])
1048                                 break;
1049                 }
1050                 rpn = rx->key->u.ccmp.rx_pn[rx->queue];
1051                 if (memcmp(pn, rpn, CCMP_PN_LEN))
1052                         return RX_DROP_UNUSABLE;
1053                 memcpy(entry->last_pn, pn, CCMP_PN_LEN);
1054         }
1055
1056         skb_pull(rx->skb, ieee80211_hdrlen(fc));
1057         __skb_queue_tail(&entry->skb_list, rx->skb);
1058         entry->last_frag = frag;
1059         entry->extra_len += rx->skb->len;
1060         if (ieee80211_has_morefrags(fc)) {
1061                 rx->skb = NULL;
1062                 return RX_QUEUED;
1063         }
1064
1065         rx->skb = __skb_dequeue(&entry->skb_list);
1066         if (skb_tailroom(rx->skb) < entry->extra_len) {
1067                 I802_DEBUG_INC(rx->local->rx_expand_skb_head2);
1068                 if (unlikely(pskb_expand_head(rx->skb, 0, entry->extra_len,
1069                                               GFP_ATOMIC))) {
1070                         I802_DEBUG_INC(rx->local->rx_handlers_drop_defrag);
1071                         __skb_queue_purge(&entry->skb_list);
1072                         return RX_DROP_UNUSABLE;
1073                 }
1074         }
1075         while ((skb = __skb_dequeue(&entry->skb_list))) {
1076                 memcpy(skb_put(rx->skb, skb->len), skb->data, skb->len);
1077                 dev_kfree_skb(skb);
1078         }
1079
1080         /* Complete frame has been reassembled - process it now */
1081         rx->flags |= IEEE80211_RX_FRAGMENTED;
1082
1083  out:
1084         if (rx->sta)
1085                 rx->sta->rx_packets++;
1086         if (is_multicast_ether_addr(hdr->addr1))
1087                 rx->local->dot11MulticastReceivedFrameCount++;
1088         else
1089                 ieee80211_led_rx(rx->local);
1090         return RX_CONTINUE;
1091 }
1092
1093 static ieee80211_rx_result debug_noinline
1094 ieee80211_rx_h_ps_poll(struct ieee80211_rx_data *rx)
1095 {
1096         struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(rx->dev);
1097         struct sk_buff *skb;
1098         int no_pending_pkts;
1099         __le16 fc = ((struct ieee80211_hdr *)rx->skb->data)->frame_control;
1100
1101         if (likely(!rx->sta || !ieee80211_is_pspoll(fc) ||
1102                    !(rx->flags & IEEE80211_RX_RA_MATCH)))
1103                 return RX_CONTINUE;
1104
1105         if ((sdata->vif.type != NL80211_IFTYPE_AP) &&
1106             (sdata->vif.type != NL80211_IFTYPE_AP_VLAN))
1107                 return RX_DROP_UNUSABLE;
1108
1109         skb = skb_dequeue(&rx->sta->tx_filtered);
1110         if (!skb) {
1111                 skb = skb_dequeue(&rx->sta->ps_tx_buf);
1112                 if (skb)
1113                         rx->local->total_ps_buffered--;
1114         }
1115         no_pending_pkts = skb_queue_empty(&rx->sta->tx_filtered) &&
1116                 skb_queue_empty(&rx->sta->ps_tx_buf);
1117
1118         if (skb) {
1119                 struct ieee80211_hdr *hdr =
1120                         (struct ieee80211_hdr *) skb->data;
1121
1122                 /*
1123                  * Tell TX path to send one frame even though the STA may
1124                  * still remain is PS mode after this frame exchange.
1125                  */
1126                 set_sta_flags(rx->sta, WLAN_STA_PSPOLL);
1127
1128 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
1129                 printk(KERN_DEBUG "STA %pM aid %d: PS Poll (entries after %d)\n",
1130                        rx->sta->sta.addr, rx->sta->sta.aid,
1131                        skb_queue_len(&rx->sta->ps_tx_buf));
1132 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
1133
1134                 /* Use MoreData flag to indicate whether there are more
1135                  * buffered frames for this STA */
1136                 if (no_pending_pkts)
1137                         hdr->frame_control &= cpu_to_le16(~IEEE80211_FCTL_MOREDATA);
1138                 else
1139                         hdr->frame_control |= cpu_to_le16(IEEE80211_FCTL_MOREDATA);
1140
1141                 dev_queue_xmit(skb);
1142
1143                 if (no_pending_pkts)
1144                         sta_info_clear_tim_bit(rx->sta);
1145 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
1146         } else if (!rx->sent_ps_buffered) {
1147                 /*
1148                  * FIXME: This can be the result of a race condition between
1149                  *        us expiring a frame and the station polling for it.
1150                  *        Should we send it a null-func frame indicating we
1151                  *        have nothing buffered for it?
1152                  */
1153                 printk(KERN_DEBUG "%s: STA %pM sent PS Poll even "
1154                        "though there are no buffered frames for it\n",
1155                        rx->dev->name, rx->sta->sta.addr);
1156 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
1157         }
1158
1159         /* Free PS Poll skb here instead of returning RX_DROP that would
1160          * count as an dropped frame. */
1161         dev_kfree_skb(rx->skb);
1162
1163         return RX_QUEUED;
1164 }
1165
1166 static ieee80211_rx_result debug_noinline
1167 ieee80211_rx_h_remove_qos_control(struct ieee80211_rx_data *rx)
1168 {
1169         u8 *data = rx->skb->data;
1170         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)data;
1171
1172         if (!ieee80211_is_data_qos(hdr->frame_control))
1173                 return RX_CONTINUE;
1174
1175         /* remove the qos control field, update frame type and meta-data */
1176         memmove(data + IEEE80211_QOS_CTL_LEN, data,
1177                 ieee80211_hdrlen(hdr->frame_control) - IEEE80211_QOS_CTL_LEN);
1178         hdr = (struct ieee80211_hdr *)skb_pull(rx->skb, IEEE80211_QOS_CTL_LEN);
1179         /* change frame type to non QOS */
1180         hdr->frame_control &= ~cpu_to_le16(IEEE80211_STYPE_QOS_DATA);
1181
1182         return RX_CONTINUE;
1183 }
1184
1185 static int
1186 ieee80211_802_1x_port_control(struct ieee80211_rx_data *rx)
1187 {
1188         if (unlikely(!rx->sta ||
1189             !test_sta_flags(rx->sta, WLAN_STA_AUTHORIZED)))
1190                 return -EACCES;
1191
1192         return 0;
1193 }
1194
1195 static int
1196 ieee80211_drop_unencrypted(struct ieee80211_rx_data *rx, __le16 fc)
1197 {
1198         /*
1199          * Pass through unencrypted frames if the hardware has
1200          * decrypted them already.
1201          */
1202         if (rx->status->flag & RX_FLAG_DECRYPTED)
1203                 return 0;
1204
1205         /* Drop unencrypted frames if key is set. */
1206         if (unlikely(!ieee80211_has_protected(fc) &&
1207                      !ieee80211_is_nullfunc(fc) &&
1208                      ieee80211_is_data(fc) &&
1209                      (rx->key || rx->sdata->drop_unencrypted)))
1210                 return -EACCES;
1211         if (rx->sta && test_sta_flags(rx->sta, WLAN_STA_MFP)) {
1212                 if (unlikely(ieee80211_is_unicast_robust_mgmt_frame(rx->skb) &&
1213                              rx->key))
1214                         return -EACCES;
1215                 /* BIP does not use Protected field, so need to check MMIE */
1216                 if (unlikely(ieee80211_is_multicast_robust_mgmt_frame(rx->skb)
1217                              && ieee80211_get_mmie_keyidx(rx->skb) < 0 &&
1218                              rx->key))
1219                         return -EACCES;
1220                 /*
1221                  * When using MFP, Action frames are not allowed prior to
1222                  * having configured keys.
1223                  */
1224                 if (unlikely(ieee80211_is_action(fc) && !rx->key &&
1225                              ieee80211_is_robust_mgmt_frame(
1226                                      (struct ieee80211_hdr *) rx->skb->data)))
1227                         return -EACCES;
1228         }
1229
1230         return 0;
1231 }
1232
1233 static int
1234 __ieee80211_data_to_8023(struct ieee80211_rx_data *rx)
1235 {
1236         struct net_device *dev = rx->dev;
1237         struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
1238
1239         return ieee80211_data_to_8023(rx->skb, dev->dev_addr, sdata->vif.type);
1240 }
1241
1242 /*
1243  * requires that rx->skb is a frame with ethernet header
1244  */
1245 static bool ieee80211_frame_allowed(struct ieee80211_rx_data *rx, __le16 fc)
1246 {
1247         static const u8 pae_group_addr[ETH_ALEN] __aligned(2)
1248                 = { 0x01, 0x80, 0xC2, 0x00, 0x00, 0x03 };
1249         struct ethhdr *ehdr = (struct ethhdr *) rx->skb->data;
1250
1251         /*
1252          * Allow EAPOL frames to us/the PAE group address regardless
1253          * of whether the frame was encrypted or not.
1254          */
1255         if (ehdr->h_proto == htons(ETH_P_PAE) &&
1256             (compare_ether_addr(ehdr->h_dest, rx->dev->dev_addr) == 0 ||
1257              compare_ether_addr(ehdr->h_dest, pae_group_addr) == 0))
1258                 return true;
1259
1260         if (ieee80211_802_1x_port_control(rx) ||
1261             ieee80211_drop_unencrypted(rx, fc))
1262                 return false;
1263
1264         return true;
1265 }
1266
1267 /*
1268  * requires that rx->skb is a frame with ethernet header
1269  */
1270 static void
1271 ieee80211_deliver_skb(struct ieee80211_rx_data *rx)
1272 {
1273         struct net_device *dev = rx->dev;
1274         struct ieee80211_local *local = rx->local;
1275         struct sk_buff *skb, *xmit_skb;
1276         struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
1277         struct ethhdr *ehdr = (struct ethhdr *) rx->skb->data;
1278         struct sta_info *dsta;
1279
1280         skb = rx->skb;
1281         xmit_skb = NULL;
1282
1283         if ((sdata->vif.type == NL80211_IFTYPE_AP ||
1284              sdata->vif.type == NL80211_IFTYPE_AP_VLAN) &&
1285             !(sdata->flags & IEEE80211_SDATA_DONT_BRIDGE_PACKETS) &&
1286             (rx->flags & IEEE80211_RX_RA_MATCH)) {
1287                 if (is_multicast_ether_addr(ehdr->h_dest)) {
1288                         /*
1289                          * send multicast frames both to higher layers in
1290                          * local net stack and back to the wireless medium
1291                          */
1292                         xmit_skb = skb_copy(skb, GFP_ATOMIC);
1293                         if (!xmit_skb && net_ratelimit())
1294                                 printk(KERN_DEBUG "%s: failed to clone "
1295                                        "multicast frame\n", dev->name);
1296                 } else {
1297                         dsta = sta_info_get(local, skb->data);
1298                         if (dsta && dsta->sdata->dev == dev) {
1299                                 /*
1300                                  * The destination station is associated to
1301                                  * this AP (in this VLAN), so send the frame
1302                                  * directly to it and do not pass it to local
1303                                  * net stack.
1304                                  */
1305                                 xmit_skb = skb;
1306                                 skb = NULL;
1307                         }
1308                 }
1309         }
1310
1311         if (skb) {
1312                 int align __maybe_unused;
1313
1314 #if defined(CONFIG_MAC80211_DEBUG_PACKET_ALIGNMENT) || !defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS)
1315                 /*
1316                  * 'align' will only take the values 0 or 2 here
1317                  * since all frames are required to be aligned
1318                  * to 2-byte boundaries when being passed to
1319                  * mac80211. That also explains the __skb_push()
1320                  * below.
1321                  */
1322                 align = ((unsigned long)(skb->data + sizeof(struct ethhdr))) & 3;
1323                 if (align) {
1324                         if (WARN_ON(skb_headroom(skb) < 3)) {
1325                                 dev_kfree_skb(skb);
1326                                 skb = NULL;
1327                         } else {
1328                                 u8 *data = skb->data;
1329                                 size_t len = skb->len;
1330                                 u8 *new = __skb_push(skb, align);
1331                                 memmove(new, data, len);
1332                                 __skb_trim(skb, len);
1333                         }
1334                 }
1335 #endif
1336
1337                 if (skb) {
1338                         /* deliver to local stack */
1339                         skb->protocol = eth_type_trans(skb, dev);
1340                         memset(skb->cb, 0, sizeof(skb->cb));
1341                         netif_rx(skb);
1342                 }
1343         }
1344
1345         if (xmit_skb) {
1346                 /* send to wireless media */
1347                 xmit_skb->protocol = htons(ETH_P_802_3);
1348                 skb_reset_network_header(xmit_skb);
1349                 skb_reset_mac_header(xmit_skb);
1350                 dev_queue_xmit(xmit_skb);
1351         }
1352 }
1353
1354 static ieee80211_rx_result debug_noinline
1355 ieee80211_rx_h_amsdu(struct ieee80211_rx_data *rx)
1356 {
1357         struct net_device *dev = rx->dev;
1358         struct ieee80211_local *local = rx->local;
1359         u16 ethertype;
1360         u8 *payload;
1361         struct sk_buff *skb = rx->skb, *frame = NULL;
1362         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
1363         __le16 fc = hdr->frame_control;
1364         const struct ethhdr *eth;
1365         int remaining, err;
1366         u8 dst[ETH_ALEN];
1367         u8 src[ETH_ALEN];
1368
1369         if (unlikely(!ieee80211_is_data(fc)))
1370                 return RX_CONTINUE;
1371
1372         if (unlikely(!ieee80211_is_data_present(fc)))
1373                 return RX_DROP_MONITOR;
1374
1375         if (!(rx->flags & IEEE80211_RX_AMSDU))
1376                 return RX_CONTINUE;
1377
1378         err = __ieee80211_data_to_8023(rx);
1379         if (unlikely(err))
1380                 return RX_DROP_UNUSABLE;
1381
1382         skb->dev = dev;
1383
1384         dev->stats.rx_packets++;
1385         dev->stats.rx_bytes += skb->len;
1386
1387         /* skip the wrapping header */
1388         eth = (struct ethhdr *) skb_pull(skb, sizeof(struct ethhdr));
1389         if (!eth)
1390                 return RX_DROP_UNUSABLE;
1391
1392         while (skb != frame) {
1393                 u8 padding;
1394                 __be16 len = eth->h_proto;
1395                 unsigned int subframe_len = sizeof(struct ethhdr) + ntohs(len);
1396
1397                 remaining = skb->len;
1398                 memcpy(dst, eth->h_dest, ETH_ALEN);
1399                 memcpy(src, eth->h_source, ETH_ALEN);
1400
1401                 padding = ((4 - subframe_len) & 0x3);
1402                 /* the last MSDU has no padding */
1403                 if (subframe_len > remaining)
1404                         return RX_DROP_UNUSABLE;
1405
1406                 skb_pull(skb, sizeof(struct ethhdr));
1407                 /* if last subframe reuse skb */
1408                 if (remaining <= subframe_len + padding)
1409                         frame = skb;
1410                 else {
1411                         /*
1412                          * Allocate and reserve two bytes more for payload
1413                          * alignment since sizeof(struct ethhdr) is 14.
1414                          */
1415                         frame = dev_alloc_skb(
1416                                 ALIGN(local->hw.extra_tx_headroom, 4) +
1417                                 subframe_len + 2);
1418
1419                         if (frame == NULL)
1420                                 return RX_DROP_UNUSABLE;
1421
1422                         skb_reserve(frame,
1423                                     ALIGN(local->hw.extra_tx_headroom, 4) +
1424                                     sizeof(struct ethhdr) + 2);
1425                         memcpy(skb_put(frame, ntohs(len)), skb->data,
1426                                 ntohs(len));
1427
1428                         eth = (struct ethhdr *) skb_pull(skb, ntohs(len) +
1429                                                         padding);
1430                         if (!eth) {
1431                                 dev_kfree_skb(frame);
1432                                 return RX_DROP_UNUSABLE;
1433                         }
1434                 }
1435
1436                 skb_reset_network_header(frame);
1437                 frame->dev = dev;
1438                 frame->priority = skb->priority;
1439                 rx->skb = frame;
1440
1441                 payload = frame->data;
1442                 ethertype = (payload[6] << 8) | payload[7];
1443
1444                 if (likely((compare_ether_addr(payload, rfc1042_header) == 0 &&
1445                             ethertype != ETH_P_AARP && ethertype != ETH_P_IPX) ||
1446                            compare_ether_addr(payload,
1447                                               bridge_tunnel_header) == 0)) {
1448                         /* remove RFC1042 or Bridge-Tunnel
1449                          * encapsulation and replace EtherType */
1450                         skb_pull(frame, 6);
1451                         memcpy(skb_push(frame, ETH_ALEN), src, ETH_ALEN);
1452                         memcpy(skb_push(frame, ETH_ALEN), dst, ETH_ALEN);
1453                 } else {
1454                         memcpy(skb_push(frame, sizeof(__be16)),
1455                                &len, sizeof(__be16));
1456                         memcpy(skb_push(frame, ETH_ALEN), src, ETH_ALEN);
1457                         memcpy(skb_push(frame, ETH_ALEN), dst, ETH_ALEN);
1458                 }
1459
1460                 if (!ieee80211_frame_allowed(rx, fc)) {
1461                         if (skb == frame) /* last frame */
1462                                 return RX_DROP_UNUSABLE;
1463                         dev_kfree_skb(frame);
1464                         continue;
1465                 }
1466
1467                 ieee80211_deliver_skb(rx);
1468         }
1469
1470         return RX_QUEUED;
1471 }
1472
1473 #ifdef CONFIG_MAC80211_MESH
1474 static ieee80211_rx_result
1475 ieee80211_rx_h_mesh_fwding(struct ieee80211_rx_data *rx)
1476 {
1477         struct ieee80211_hdr *hdr;
1478         struct ieee80211s_hdr *mesh_hdr;
1479         unsigned int hdrlen;
1480         struct sk_buff *skb = rx->skb, *fwd_skb;
1481         struct ieee80211_local *local = rx->local;
1482         struct ieee80211_sub_if_data *sdata;
1483
1484         hdr = (struct ieee80211_hdr *) skb->data;
1485         hdrlen = ieee80211_hdrlen(hdr->frame_control);
1486         mesh_hdr = (struct ieee80211s_hdr *) (skb->data + hdrlen);
1487         sdata = IEEE80211_DEV_TO_SUB_IF(rx->dev);
1488
1489         if (!ieee80211_is_data(hdr->frame_control))
1490                 return RX_CONTINUE;
1491
1492         if (!mesh_hdr->ttl)
1493                 /* illegal frame */
1494                 return RX_DROP_MONITOR;
1495
1496         if (mesh_hdr->flags & MESH_FLAGS_AE_A5_A6){
1497                 struct mesh_path *mppath;
1498
1499                 rcu_read_lock();
1500                 mppath = mpp_path_lookup(mesh_hdr->eaddr2, sdata);
1501                 if (!mppath) {
1502                         mpp_path_add(mesh_hdr->eaddr2, hdr->addr4, sdata);
1503                 } else {
1504                         spin_lock_bh(&mppath->state_lock);
1505                         mppath->exp_time = jiffies;
1506                         if (compare_ether_addr(mppath->mpp, hdr->addr4) != 0)
1507                                 memcpy(mppath->mpp, hdr->addr4, ETH_ALEN);
1508                         spin_unlock_bh(&mppath->state_lock);
1509                 }
1510                 rcu_read_unlock();
1511         }
1512
1513         if (compare_ether_addr(rx->dev->dev_addr, hdr->addr3) == 0)
1514                 return RX_CONTINUE;
1515
1516         mesh_hdr->ttl--;
1517
1518         if (rx->flags & IEEE80211_RX_RA_MATCH) {
1519                 if (!mesh_hdr->ttl)
1520                         IEEE80211_IFSTA_MESH_CTR_INC(&rx->sdata->u.mesh,
1521                                                      dropped_frames_ttl);
1522                 else {
1523                         struct ieee80211_hdr *fwd_hdr;
1524                         struct ieee80211_tx_info *info;
1525
1526                         fwd_skb = skb_copy(skb, GFP_ATOMIC);
1527
1528                         if (!fwd_skb && net_ratelimit())
1529                                 printk(KERN_DEBUG "%s: failed to clone mesh frame\n",
1530                                                    rx->dev->name);
1531
1532                         fwd_hdr =  (struct ieee80211_hdr *) fwd_skb->data;
1533                         /*
1534                          * Save TA to addr1 to send TA a path error if a
1535                          * suitable next hop is not found
1536                          */
1537                         memcpy(fwd_hdr->addr1, fwd_hdr->addr2, ETH_ALEN);
1538                         memcpy(fwd_hdr->addr2, rx->dev->dev_addr, ETH_ALEN);
1539                         info = IEEE80211_SKB_CB(fwd_skb);
1540                         memset(info, 0, sizeof(*info));
1541                         info->flags |= IEEE80211_TX_INTFL_NEED_TXPROCESSING;
1542                         info->control.vif = &rx->sdata->vif;
1543                         ieee80211_select_queue(local, fwd_skb);
1544                         if (is_multicast_ether_addr(fwd_hdr->addr3))
1545                                 memcpy(fwd_hdr->addr1, fwd_hdr->addr3,
1546                                                 ETH_ALEN);
1547                         else {
1548                                 int err = mesh_nexthop_lookup(fwd_skb, sdata);
1549                                 /* Failed to immediately resolve next hop:
1550                                  * fwded frame was dropped or will be added
1551                                  * later to the pending skb queue.  */
1552                                 if (err)
1553                                         return RX_DROP_MONITOR;
1554                         }
1555                         IEEE80211_IFSTA_MESH_CTR_INC(&sdata->u.mesh,
1556                                                      fwded_frames);
1557                         ieee80211_add_pending_skb(local, fwd_skb);
1558                 }
1559         }
1560
1561         if (is_multicast_ether_addr(hdr->addr3) ||
1562             rx->dev->flags & IFF_PROMISC)
1563                 return RX_CONTINUE;
1564         else
1565                 return RX_DROP_MONITOR;
1566 }
1567 #endif
1568
1569 static ieee80211_rx_result debug_noinline
1570 ieee80211_rx_h_data(struct ieee80211_rx_data *rx)
1571 {
1572         struct net_device *dev = rx->dev;
1573         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
1574         __le16 fc = hdr->frame_control;
1575         int err;
1576
1577         if (unlikely(!ieee80211_is_data(hdr->frame_control)))
1578                 return RX_CONTINUE;
1579
1580         if (unlikely(!ieee80211_is_data_present(hdr->frame_control)))
1581                 return RX_DROP_MONITOR;
1582
1583         err = __ieee80211_data_to_8023(rx);
1584         if (unlikely(err))
1585                 return RX_DROP_UNUSABLE;
1586
1587         if (!ieee80211_frame_allowed(rx, fc))
1588                 return RX_DROP_MONITOR;
1589
1590         rx->skb->dev = dev;
1591
1592         dev->stats.rx_packets++;
1593         dev->stats.rx_bytes += rx->skb->len;
1594
1595         ieee80211_deliver_skb(rx);
1596
1597         return RX_QUEUED;
1598 }
1599
1600 static ieee80211_rx_result debug_noinline
1601 ieee80211_rx_h_ctrl(struct ieee80211_rx_data *rx)
1602 {
1603         struct ieee80211_local *local = rx->local;
1604         struct ieee80211_hw *hw = &local->hw;
1605         struct sk_buff *skb = rx->skb;
1606         struct ieee80211_bar *bar = (struct ieee80211_bar *)skb->data;
1607         struct tid_ampdu_rx *tid_agg_rx;
1608         u16 start_seq_num;
1609         u16 tid;
1610
1611         if (likely(!ieee80211_is_ctl(bar->frame_control)))
1612                 return RX_CONTINUE;
1613
1614         if (ieee80211_is_back_req(bar->frame_control)) {
1615                 if (!rx->sta)
1616                         return RX_CONTINUE;
1617                 tid = le16_to_cpu(bar->control) >> 12;
1618                 if (rx->sta->ampdu_mlme.tid_state_rx[tid]
1619                                         != HT_AGG_STATE_OPERATIONAL)
1620                         return RX_CONTINUE;
1621                 tid_agg_rx = rx->sta->ampdu_mlme.tid_rx[tid];
1622
1623                 start_seq_num = le16_to_cpu(bar->start_seq_num) >> 4;
1624
1625                 /* reset session timer */
1626                 if (tid_agg_rx->timeout)
1627                         mod_timer(&tid_agg_rx->session_timer,
1628                                   TU_TO_EXP_TIME(tid_agg_rx->timeout));
1629
1630                 /* manage reordering buffer according to requested */
1631                 /* sequence number */
1632                 rcu_read_lock();
1633                 ieee80211_sta_manage_reorder_buf(hw, tid_agg_rx, NULL,
1634                                                  start_seq_num, 1);
1635                 rcu_read_unlock();
1636                 return RX_DROP_UNUSABLE;
1637         }
1638
1639         return RX_CONTINUE;
1640 }
1641
1642 static void ieee80211_process_sa_query_req(struct ieee80211_sub_if_data *sdata,
1643                                            struct ieee80211_mgmt *mgmt,
1644                                            size_t len)
1645 {
1646         struct ieee80211_local *local = sdata->local;
1647         struct sk_buff *skb;
1648         struct ieee80211_mgmt *resp;
1649
1650         if (compare_ether_addr(mgmt->da, sdata->dev->dev_addr) != 0) {
1651                 /* Not to own unicast address */
1652                 return;
1653         }
1654
1655         if (compare_ether_addr(mgmt->sa, sdata->u.mgd.bssid) != 0 ||
1656             compare_ether_addr(mgmt->bssid, sdata->u.mgd.bssid) != 0) {
1657                 /* Not from the current AP or not associated yet. */
1658                 return;
1659         }
1660
1661         if (len < 24 + 1 + sizeof(resp->u.action.u.sa_query)) {
1662                 /* Too short SA Query request frame */
1663                 return;
1664         }
1665
1666         skb = dev_alloc_skb(sizeof(*resp) + local->hw.extra_tx_headroom);
1667         if (skb == NULL)
1668                 return;
1669
1670         skb_reserve(skb, local->hw.extra_tx_headroom);
1671         resp = (struct ieee80211_mgmt *) skb_put(skb, 24);
1672         memset(resp, 0, 24);
1673         memcpy(resp->da, mgmt->sa, ETH_ALEN);
1674         memcpy(resp->sa, sdata->dev->dev_addr, ETH_ALEN);
1675         memcpy(resp->bssid, sdata->u.mgd.bssid, ETH_ALEN);
1676         resp->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
1677                                           IEEE80211_STYPE_ACTION);
1678         skb_put(skb, 1 + sizeof(resp->u.action.u.sa_query));
1679         resp->u.action.category = WLAN_CATEGORY_SA_QUERY;
1680         resp->u.action.u.sa_query.action = WLAN_ACTION_SA_QUERY_RESPONSE;
1681         memcpy(resp->u.action.u.sa_query.trans_id,
1682                mgmt->u.action.u.sa_query.trans_id,
1683                WLAN_SA_QUERY_TR_ID_LEN);
1684
1685         ieee80211_tx_skb(sdata, skb, 1);
1686 }
1687
1688 static ieee80211_rx_result debug_noinline
1689 ieee80211_rx_h_action(struct ieee80211_rx_data *rx)
1690 {
1691         struct ieee80211_local *local = rx->local;
1692         struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(rx->dev);
1693         struct ieee80211_mgmt *mgmt = (struct ieee80211_mgmt *) rx->skb->data;
1694         int len = rx->skb->len;
1695
1696         if (!ieee80211_is_action(mgmt->frame_control))
1697                 return RX_CONTINUE;
1698
1699         if (!rx->sta)
1700                 return RX_DROP_MONITOR;
1701
1702         if (!(rx->flags & IEEE80211_RX_RA_MATCH))
1703                 return RX_DROP_MONITOR;
1704
1705         if (ieee80211_drop_unencrypted(rx, mgmt->frame_control))
1706                 return RX_DROP_MONITOR;
1707
1708         /* all categories we currently handle have action_code */
1709         if (len < IEEE80211_MIN_ACTION_SIZE + 1)
1710                 return RX_DROP_MONITOR;
1711
1712         switch (mgmt->u.action.category) {
1713         case WLAN_CATEGORY_BACK:
1714                 /*
1715                  * The aggregation code is not prepared to handle
1716                  * anything but STA/AP due to the BSSID handling;
1717                  * IBSS could work in the code but isn't supported
1718                  * by drivers or the standard.
1719                  */
1720                 if (sdata->vif.type != NL80211_IFTYPE_STATION &&
1721                     sdata->vif.type != NL80211_IFTYPE_AP_VLAN &&
1722                     sdata->vif.type != NL80211_IFTYPE_AP)
1723                         return RX_DROP_MONITOR;
1724
1725                 switch (mgmt->u.action.u.addba_req.action_code) {
1726                 case WLAN_ACTION_ADDBA_REQ:
1727                         if (len < (IEEE80211_MIN_ACTION_SIZE +
1728                                    sizeof(mgmt->u.action.u.addba_req)))
1729                                 return RX_DROP_MONITOR;
1730                         ieee80211_process_addba_request(local, rx->sta, mgmt, len);
1731                         break;
1732                 case WLAN_ACTION_ADDBA_RESP:
1733                         if (len < (IEEE80211_MIN_ACTION_SIZE +
1734                                    sizeof(mgmt->u.action.u.addba_resp)))
1735                                 return RX_DROP_MONITOR;
1736                         ieee80211_process_addba_resp(local, rx->sta, mgmt, len);
1737                         break;
1738                 case WLAN_ACTION_DELBA:
1739                         if (len < (IEEE80211_MIN_ACTION_SIZE +
1740                                    sizeof(mgmt->u.action.u.delba)))
1741                                 return RX_DROP_MONITOR;
1742                         ieee80211_process_delba(sdata, rx->sta, mgmt, len);
1743                         break;
1744                 }
1745                 break;
1746         case WLAN_CATEGORY_SPECTRUM_MGMT:
1747                 if (local->hw.conf.channel->band != IEEE80211_BAND_5GHZ)
1748                         return RX_DROP_MONITOR;
1749
1750                 if (sdata->vif.type != NL80211_IFTYPE_STATION)
1751                         return RX_DROP_MONITOR;
1752
1753                 switch (mgmt->u.action.u.measurement.action_code) {
1754                 case WLAN_ACTION_SPCT_MSR_REQ:
1755                         if (len < (IEEE80211_MIN_ACTION_SIZE +
1756                                    sizeof(mgmt->u.action.u.measurement)))
1757                                 return RX_DROP_MONITOR;
1758                         ieee80211_process_measurement_req(sdata, mgmt, len);
1759                         break;
1760                 case WLAN_ACTION_SPCT_CHL_SWITCH:
1761                         if (len < (IEEE80211_MIN_ACTION_SIZE +
1762                                    sizeof(mgmt->u.action.u.chan_switch)))
1763                                 return RX_DROP_MONITOR;
1764
1765                         if (sdata->vif.type != NL80211_IFTYPE_STATION)
1766                                 return RX_DROP_MONITOR;
1767
1768                         if (memcmp(mgmt->bssid, sdata->u.mgd.bssid, ETH_ALEN))
1769                                 return RX_DROP_MONITOR;
1770
1771                         return ieee80211_sta_rx_mgmt(sdata, rx->skb);
1772                 }
1773                 break;
1774         case WLAN_CATEGORY_SA_QUERY:
1775                 if (len < (IEEE80211_MIN_ACTION_SIZE +
1776                            sizeof(mgmt->u.action.u.sa_query)))
1777                         return RX_DROP_MONITOR;
1778                 switch (mgmt->u.action.u.sa_query.action) {
1779                 case WLAN_ACTION_SA_QUERY_REQUEST:
1780                         if (sdata->vif.type != NL80211_IFTYPE_STATION)
1781                                 return RX_DROP_MONITOR;
1782                         ieee80211_process_sa_query_req(sdata, mgmt, len);
1783                         break;
1784                 case WLAN_ACTION_SA_QUERY_RESPONSE:
1785                         /*
1786                          * SA Query response is currently only used in AP mode
1787                          * and it is processed in user space.
1788                          */
1789                         return RX_CONTINUE;
1790                 }
1791                 break;
1792         default:
1793                 return RX_CONTINUE;
1794         }
1795
1796         rx->sta->rx_packets++;
1797         dev_kfree_skb(rx->skb);
1798         return RX_QUEUED;
1799 }
1800
1801 static ieee80211_rx_result debug_noinline
1802 ieee80211_rx_h_mgmt(struct ieee80211_rx_data *rx)
1803 {
1804         struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(rx->dev);
1805         struct ieee80211_mgmt *mgmt = (struct ieee80211_mgmt *) rx->skb->data;
1806
1807         if (!(rx->flags & IEEE80211_RX_RA_MATCH))
1808                 return RX_DROP_MONITOR;
1809
1810         if (ieee80211_drop_unencrypted(rx, mgmt->frame_control))
1811                 return RX_DROP_MONITOR;
1812
1813         if (ieee80211_vif_is_mesh(&sdata->vif))
1814                 return ieee80211_mesh_rx_mgmt(sdata, rx->skb);
1815
1816         if (sdata->vif.type == NL80211_IFTYPE_ADHOC)
1817                 return ieee80211_ibss_rx_mgmt(sdata, rx->skb);
1818
1819         if (sdata->vif.type == NL80211_IFTYPE_STATION)
1820                 return ieee80211_sta_rx_mgmt(sdata, rx->skb);
1821
1822         return RX_DROP_MONITOR;
1823 }
1824
1825 static void ieee80211_rx_michael_mic_report(struct ieee80211_hdr *hdr,
1826                                             struct ieee80211_rx_data *rx)
1827 {
1828         int keyidx;
1829         unsigned int hdrlen;
1830
1831         hdrlen = ieee80211_hdrlen(hdr->frame_control);
1832         if (rx->skb->len >= hdrlen + 4)
1833                 keyidx = rx->skb->data[hdrlen + 3] >> 6;
1834         else
1835                 keyidx = -1;
1836
1837         if (!rx->sta) {
1838                 /*
1839                  * Some hardware seem to generate incorrect Michael MIC
1840                  * reports; ignore them to avoid triggering countermeasures.
1841                  */
1842                 goto ignore;
1843         }
1844
1845         if (!ieee80211_has_protected(hdr->frame_control))
1846                 goto ignore;
1847
1848         if (rx->sdata->vif.type == NL80211_IFTYPE_AP && keyidx) {
1849                 /*
1850                  * APs with pairwise keys should never receive Michael MIC
1851                  * errors for non-zero keyidx because these are reserved for
1852                  * group keys and only the AP is sending real multicast
1853                  * frames in the BSS.
1854                  */
1855                 goto ignore;
1856         }
1857
1858         if (!ieee80211_is_data(hdr->frame_control) &&
1859             !ieee80211_is_auth(hdr->frame_control))
1860                 goto ignore;
1861
1862         mac80211_ev_michael_mic_failure(rx->sdata, keyidx, hdr, NULL,
1863                                         GFP_ATOMIC);
1864  ignore:
1865         dev_kfree_skb(rx->skb);
1866         rx->skb = NULL;
1867 }
1868
1869 /* TODO: use IEEE80211_RX_FRAGMENTED */
1870 static void ieee80211_rx_cooked_monitor(struct ieee80211_rx_data *rx)
1871 {
1872         struct ieee80211_sub_if_data *sdata;
1873         struct ieee80211_local *local = rx->local;
1874         struct ieee80211_rtap_hdr {
1875                 struct ieee80211_radiotap_header hdr;
1876                 u8 flags;
1877                 u8 rate;
1878                 __le16 chan_freq;
1879                 __le16 chan_flags;
1880         } __attribute__ ((packed)) *rthdr;
1881         struct sk_buff *skb = rx->skb, *skb2;
1882         struct net_device *prev_dev = NULL;
1883         struct ieee80211_rx_status *status = rx->status;
1884
1885         if (rx->flags & IEEE80211_RX_CMNTR_REPORTED)
1886                 goto out_free_skb;
1887
1888         if (skb_headroom(skb) < sizeof(*rthdr) &&
1889             pskb_expand_head(skb, sizeof(*rthdr), 0, GFP_ATOMIC))
1890                 goto out_free_skb;
1891
1892         rthdr = (void *)skb_push(skb, sizeof(*rthdr));
1893         memset(rthdr, 0, sizeof(*rthdr));
1894         rthdr->hdr.it_len = cpu_to_le16(sizeof(*rthdr));
1895         rthdr->hdr.it_present =
1896                 cpu_to_le32((1 << IEEE80211_RADIOTAP_FLAGS) |
1897                             (1 << IEEE80211_RADIOTAP_RATE) |
1898                             (1 << IEEE80211_RADIOTAP_CHANNEL));
1899
1900         rthdr->rate = rx->rate->bitrate / 5;
1901         rthdr->chan_freq = cpu_to_le16(status->freq);
1902
1903         if (status->band == IEEE80211_BAND_5GHZ)
1904                 rthdr->chan_flags = cpu_to_le16(IEEE80211_CHAN_OFDM |
1905                                                 IEEE80211_CHAN_5GHZ);
1906         else
1907                 rthdr->chan_flags = cpu_to_le16(IEEE80211_CHAN_DYN |
1908                                                 IEEE80211_CHAN_2GHZ);
1909
1910         skb_set_mac_header(skb, 0);
1911         skb->ip_summed = CHECKSUM_UNNECESSARY;
1912         skb->pkt_type = PACKET_OTHERHOST;
1913         skb->protocol = htons(ETH_P_802_2);
1914
1915         list_for_each_entry_rcu(sdata, &local->interfaces, list) {
1916                 if (!netif_running(sdata->dev))
1917                         continue;
1918
1919                 if (sdata->vif.type != NL80211_IFTYPE_MONITOR ||
1920                     !(sdata->u.mntr_flags & MONITOR_FLAG_COOK_FRAMES))
1921                         continue;
1922
1923                 if (prev_dev) {
1924                         skb2 = skb_clone(skb, GFP_ATOMIC);
1925                         if (skb2) {
1926                                 skb2->dev = prev_dev;
1927                                 netif_rx(skb2);
1928                         }
1929                 }
1930
1931                 prev_dev = sdata->dev;
1932                 sdata->dev->stats.rx_packets++;
1933                 sdata->dev->stats.rx_bytes += skb->len;
1934         }
1935
1936         if (prev_dev) {
1937                 skb->dev = prev_dev;
1938                 netif_rx(skb);
1939                 skb = NULL;
1940         } else
1941                 goto out_free_skb;
1942
1943         rx->flags |= IEEE80211_RX_CMNTR_REPORTED;
1944         return;
1945
1946  out_free_skb:
1947         dev_kfree_skb(skb);
1948 }
1949
1950
1951 static void ieee80211_invoke_rx_handlers(struct ieee80211_sub_if_data *sdata,
1952                                          struct ieee80211_rx_data *rx,
1953                                          struct sk_buff *skb)
1954 {
1955         ieee80211_rx_result res = RX_DROP_MONITOR;
1956
1957         rx->skb = skb;
1958         rx->sdata = sdata;
1959         rx->dev = sdata->dev;
1960
1961 #define CALL_RXH(rxh)                   \
1962         do {                            \
1963                 res = rxh(rx);          \
1964                 if (res != RX_CONTINUE) \
1965                         goto rxh_done;  \
1966         } while (0);
1967
1968         CALL_RXH(ieee80211_rx_h_passive_scan)
1969         CALL_RXH(ieee80211_rx_h_check)
1970         CALL_RXH(ieee80211_rx_h_decrypt)
1971         CALL_RXH(ieee80211_rx_h_check_more_data)
1972         CALL_RXH(ieee80211_rx_h_sta_process)
1973         CALL_RXH(ieee80211_rx_h_defragment)
1974         CALL_RXH(ieee80211_rx_h_ps_poll)
1975         CALL_RXH(ieee80211_rx_h_michael_mic_verify)
1976         /* must be after MMIC verify so header is counted in MPDU mic */
1977         CALL_RXH(ieee80211_rx_h_remove_qos_control)
1978         CALL_RXH(ieee80211_rx_h_amsdu)
1979 #ifdef CONFIG_MAC80211_MESH
1980         if (ieee80211_vif_is_mesh(&sdata->vif))
1981                 CALL_RXH(ieee80211_rx_h_mesh_fwding);
1982 #endif
1983         CALL_RXH(ieee80211_rx_h_data)
1984         CALL_RXH(ieee80211_rx_h_ctrl)
1985         CALL_RXH(ieee80211_rx_h_action)
1986         CALL_RXH(ieee80211_rx_h_mgmt)
1987
1988 #undef CALL_RXH
1989
1990  rxh_done:
1991         switch (res) {
1992         case RX_DROP_MONITOR:
1993                 I802_DEBUG_INC(sdata->local->rx_handlers_drop);
1994                 if (rx->sta)
1995                         rx->sta->rx_dropped++;
1996                 /* fall through */
1997         case RX_CONTINUE:
1998                 ieee80211_rx_cooked_monitor(rx);
1999                 break;
2000         case RX_DROP_UNUSABLE:
2001                 I802_DEBUG_INC(sdata->local->rx_handlers_drop);
2002                 if (rx->sta)
2003                         rx->sta->rx_dropped++;
2004                 dev_kfree_skb(rx->skb);
2005                 break;
2006         case RX_QUEUED:
2007                 I802_DEBUG_INC(sdata->local->rx_handlers_queued);
2008                 break;
2009         }
2010 }
2011
2012 /* main receive path */
2013
2014 static int prepare_for_handlers(struct ieee80211_sub_if_data *sdata,
2015                                 struct ieee80211_rx_data *rx,
2016                                 struct ieee80211_hdr *hdr)
2017 {
2018         u8 *bssid = ieee80211_get_bssid(hdr, rx->skb->len, sdata->vif.type);
2019         int multicast = is_multicast_ether_addr(hdr->addr1);
2020
2021         switch (sdata->vif.type) {
2022         case NL80211_IFTYPE_STATION:
2023                 if (!bssid)
2024                         return 0;
2025                 if (!multicast &&
2026                     compare_ether_addr(sdata->dev->dev_addr, hdr->addr1) != 0) {
2027                         if (!(sdata->dev->flags & IFF_PROMISC))
2028                                 return 0;
2029                         rx->flags &= ~IEEE80211_RX_RA_MATCH;
2030                 }
2031                 break;
2032         case NL80211_IFTYPE_ADHOC:
2033                 if (!bssid)
2034                         return 0;
2035                 if (ieee80211_is_beacon(hdr->frame_control)) {
2036                         return 1;
2037                 }
2038                 else if (!ieee80211_bssid_match(bssid, sdata->u.ibss.bssid)) {
2039                         if (!(rx->flags & IEEE80211_RX_IN_SCAN))
2040                                 return 0;
2041                         rx->flags &= ~IEEE80211_RX_RA_MATCH;
2042                 } else if (!multicast &&
2043                            compare_ether_addr(sdata->dev->dev_addr,
2044                                               hdr->addr1) != 0) {
2045                         if (!(sdata->dev->flags & IFF_PROMISC))
2046                                 return 0;
2047                         rx->flags &= ~IEEE80211_RX_RA_MATCH;
2048                 } else if (!rx->sta) {
2049                         int rate_idx;
2050                         if (rx->status->flag & RX_FLAG_HT)
2051                                 rate_idx = 0; /* TODO: HT rates */
2052                         else
2053                                 rate_idx = rx->status->rate_idx;
2054                         rx->sta = ieee80211_ibss_add_sta(sdata, bssid, hdr->addr2,
2055                                 BIT(rate_idx));
2056                 }
2057                 break;
2058         case NL80211_IFTYPE_MESH_POINT:
2059                 if (!multicast &&
2060                     compare_ether_addr(sdata->dev->dev_addr,
2061                                        hdr->addr1) != 0) {
2062                         if (!(sdata->dev->flags & IFF_PROMISC))
2063                                 return 0;
2064
2065                         rx->flags &= ~IEEE80211_RX_RA_MATCH;
2066                 }
2067                 break;
2068         case NL80211_IFTYPE_AP_VLAN:
2069         case NL80211_IFTYPE_AP:
2070                 if (!bssid) {
2071                         if (compare_ether_addr(sdata->dev->dev_addr,
2072                                                hdr->addr1))
2073                                 return 0;
2074                 } else if (!ieee80211_bssid_match(bssid,
2075                                         sdata->dev->dev_addr)) {
2076                         if (!(rx->flags & IEEE80211_RX_IN_SCAN))
2077                                 return 0;
2078                         rx->flags &= ~IEEE80211_RX_RA_MATCH;
2079                 }
2080                 break;
2081         case NL80211_IFTYPE_WDS:
2082                 if (bssid || !ieee80211_is_data(hdr->frame_control))
2083                         return 0;
2084                 if (compare_ether_addr(sdata->u.wds.remote_addr, hdr->addr2))
2085                         return 0;
2086                 break;
2087         case NL80211_IFTYPE_MONITOR:
2088                 /* take everything */
2089                 break;
2090         case NL80211_IFTYPE_UNSPECIFIED:
2091         case __NL80211_IFTYPE_AFTER_LAST:
2092                 /* should never get here */
2093                 WARN_ON(1);
2094                 break;
2095         }
2096
2097         return 1;
2098 }
2099
2100 /*
2101  * This is the actual Rx frames handler. as it blongs to Rx path it must
2102  * be called with rcu_read_lock protection.
2103  */
2104 static void __ieee80211_rx_handle_packet(struct ieee80211_hw *hw,
2105                                          struct sk_buff *skb,
2106                                          struct ieee80211_rate *rate)
2107 {
2108         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
2109         struct ieee80211_local *local = hw_to_local(hw);
2110         struct ieee80211_sub_if_data *sdata;
2111         struct ieee80211_hdr *hdr;
2112         struct ieee80211_rx_data rx;
2113         int prepares;
2114         struct ieee80211_sub_if_data *prev = NULL;
2115         struct sk_buff *skb_new;
2116
2117         hdr = (struct ieee80211_hdr *)skb->data;
2118         memset(&rx, 0, sizeof(rx));
2119         rx.skb = skb;
2120         rx.local = local;
2121
2122         rx.status = status;
2123         rx.rate = rate;
2124
2125         if (ieee80211_is_data(hdr->frame_control) || ieee80211_is_mgmt(hdr->frame_control))
2126                 local->dot11ReceivedFragmentCount++;
2127
2128         rx.sta = sta_info_get(local, hdr->addr2);
2129         if (rx.sta) {
2130                 rx.sdata = rx.sta->sdata;
2131                 rx.dev = rx.sta->sdata->dev;
2132         }
2133
2134         if ((status->flag & RX_FLAG_MMIC_ERROR)) {
2135                 ieee80211_rx_michael_mic_report(hdr, &rx);
2136                 return;
2137         }
2138
2139         if (unlikely(local->sw_scanning || local->hw_scanning))
2140                 rx.flags |= IEEE80211_RX_IN_SCAN;
2141
2142         ieee80211_parse_qos(&rx);
2143         ieee80211_verify_alignment(&rx);
2144
2145         skb = rx.skb;
2146
2147         list_for_each_entry_rcu(sdata, &local->interfaces, list) {
2148                 if (!netif_running(sdata->dev))
2149                         continue;
2150
2151                 if (sdata->vif.type == NL80211_IFTYPE_MONITOR)
2152                         continue;
2153
2154                 rx.flags |= IEEE80211_RX_RA_MATCH;
2155                 prepares = prepare_for_handlers(sdata, &rx, hdr);
2156
2157                 if (!prepares)
2158                         continue;
2159
2160                 /*
2161                  * frame is destined for this interface, but if it's not
2162                  * also for the previous one we handle that after the
2163                  * loop to avoid copying the SKB once too much
2164                  */
2165
2166                 if (!prev) {
2167                         prev = sdata;
2168                         continue;
2169                 }
2170
2171                 /*
2172                  * frame was destined for the previous interface
2173                  * so invoke RX handlers for it
2174                  */
2175
2176                 skb_new = skb_copy(skb, GFP_ATOMIC);
2177                 if (!skb_new) {
2178                         if (net_ratelimit())
2179                                 printk(KERN_DEBUG "%s: failed to copy "
2180                                        "multicast frame for %s\n",
2181                                        wiphy_name(local->hw.wiphy),
2182                                        prev->dev->name);
2183                         continue;
2184                 }
2185                 ieee80211_invoke_rx_handlers(prev, &rx, skb_new);
2186                 prev = sdata;
2187         }
2188         if (prev)
2189                 ieee80211_invoke_rx_handlers(prev, &rx, skb);
2190         else
2191                 dev_kfree_skb(skb);
2192 }
2193
2194 #define SEQ_MODULO 0x1000
2195 #define SEQ_MASK   0xfff
2196
2197 static inline int seq_less(u16 sq1, u16 sq2)
2198 {
2199         return ((sq1 - sq2) & SEQ_MASK) > (SEQ_MODULO >> 1);
2200 }
2201
2202 static inline u16 seq_inc(u16 sq)
2203 {
2204         return (sq + 1) & SEQ_MASK;
2205 }
2206
2207 static inline u16 seq_sub(u16 sq1, u16 sq2)
2208 {
2209         return (sq1 - sq2) & SEQ_MASK;
2210 }
2211
2212
2213 static void ieee80211_release_reorder_frame(struct ieee80211_hw *hw,
2214                                             struct tid_ampdu_rx *tid_agg_rx,
2215                                             int index)
2216 {
2217         struct ieee80211_supported_band *sband;
2218         struct ieee80211_rate *rate;
2219         struct sk_buff *skb = tid_agg_rx->reorder_buf[index];
2220         struct ieee80211_rx_status *status;
2221
2222         if (!skb)
2223                 goto no_frame;
2224
2225         status = IEEE80211_SKB_RXCB(skb);
2226
2227         /* release the reordered frames to stack */
2228         sband = hw->wiphy->bands[status->band];
2229         if (status->flag & RX_FLAG_HT)
2230                 rate = sband->bitrates; /* TODO: HT rates */
2231         else
2232                 rate = &sband->bitrates[status->rate_idx];
2233         __ieee80211_rx_handle_packet(hw, skb, rate);
2234         tid_agg_rx->stored_mpdu_num--;
2235         tid_agg_rx->reorder_buf[index] = NULL;
2236
2237 no_frame:
2238         tid_agg_rx->head_seq_num = seq_inc(tid_agg_rx->head_seq_num);
2239 }
2240
2241
2242 /*
2243  * Timeout (in jiffies) for skb's that are waiting in the RX reorder buffer. If
2244  * the skb was added to the buffer longer than this time ago, the earlier
2245  * frames that have not yet been received are assumed to be lost and the skb
2246  * can be released for processing. This may also release other skb's from the
2247  * reorder buffer if there are no additional gaps between the frames.
2248  */
2249 #define HT_RX_REORDER_BUF_TIMEOUT (HZ / 10)
2250
2251 /*
2252  * As it function blongs to Rx path it must be called with
2253  * the proper rcu_read_lock protection for its flow.
2254  */
2255 static u8 ieee80211_sta_manage_reorder_buf(struct ieee80211_hw *hw,
2256                                            struct tid_ampdu_rx *tid_agg_rx,
2257                                            struct sk_buff *skb,
2258                                            u16 mpdu_seq_num,
2259                                            int bar_req)
2260 {
2261         u16 head_seq_num, buf_size;
2262         int index;
2263
2264         buf_size = tid_agg_rx->buf_size;
2265         head_seq_num = tid_agg_rx->head_seq_num;
2266
2267         /* frame with out of date sequence number */
2268         if (seq_less(mpdu_seq_num, head_seq_num)) {
2269                 dev_kfree_skb(skb);
2270                 return 1;
2271         }
2272
2273         /* if frame sequence number exceeds our buffering window size or
2274          * block Ack Request arrived - release stored frames */
2275         if ((!seq_less(mpdu_seq_num, head_seq_num + buf_size)) || (bar_req)) {
2276                 /* new head to the ordering buffer */
2277                 if (bar_req)
2278                         head_seq_num = mpdu_seq_num;
2279                 else
2280                         head_seq_num =
2281                                 seq_inc(seq_sub(mpdu_seq_num, buf_size));
2282                 /* release stored frames up to new head to stack */
2283                 while (seq_less(tid_agg_rx->head_seq_num, head_seq_num)) {
2284                         index = seq_sub(tid_agg_rx->head_seq_num,
2285                                 tid_agg_rx->ssn)
2286                                 % tid_agg_rx->buf_size;
2287                         ieee80211_release_reorder_frame(hw, tid_agg_rx,
2288                                                         index);
2289                 }
2290                 if (bar_req)
2291                         return 1;
2292         }
2293
2294         /* now the new frame is always in the range of the reordering */
2295         /* buffer window */
2296         index = seq_sub(mpdu_seq_num, tid_agg_rx->ssn)
2297                                 % tid_agg_rx->buf_size;
2298         /* check if we already stored this frame */
2299         if (tid_agg_rx->reorder_buf[index]) {
2300                 dev_kfree_skb(skb);
2301                 return 1;
2302         }
2303
2304         /* if arrived mpdu is in the right order and nothing else stored */
2305         /* release it immediately */
2306         if (mpdu_seq_num == tid_agg_rx->head_seq_num &&
2307                         tid_agg_rx->stored_mpdu_num == 0) {
2308                 tid_agg_rx->head_seq_num =
2309                         seq_inc(tid_agg_rx->head_seq_num);
2310                 return 0;
2311         }
2312
2313         /* put the frame in the reordering buffer */
2314         tid_agg_rx->reorder_buf[index] = skb;
2315         tid_agg_rx->reorder_time[index] = jiffies;
2316         tid_agg_rx->stored_mpdu_num++;
2317         /* release the buffer until next missing frame */
2318         index = seq_sub(tid_agg_rx->head_seq_num, tid_agg_rx->ssn)
2319                                                 % tid_agg_rx->buf_size;
2320         if (!tid_agg_rx->reorder_buf[index] &&
2321             tid_agg_rx->stored_mpdu_num > 1) {
2322                 /*
2323                  * No buffers ready to be released, but check whether any
2324                  * frames in the reorder buffer have timed out.
2325                  */
2326                 int j;
2327                 int skipped = 1;
2328                 for (j = (index + 1) % tid_agg_rx->buf_size; j != index;
2329                      j = (j + 1) % tid_agg_rx->buf_size) {
2330                         if (tid_agg_rx->reorder_buf[j] == NULL) {
2331                                 skipped++;
2332                                 continue;
2333                         }
2334                         if (!time_after(jiffies, tid_agg_rx->reorder_time[j] +
2335                                         HZ / 10))
2336                                 break;
2337
2338 #ifdef CONFIG_MAC80211_HT_DEBUG
2339                         if (net_ratelimit())
2340                                 printk(KERN_DEBUG "%s: release an RX reorder "
2341                                        "frame due to timeout on earlier "
2342                                        "frames\n",
2343                                        wiphy_name(hw->wiphy));
2344 #endif
2345                         ieee80211_release_reorder_frame(hw, tid_agg_rx, j);
2346
2347                         /*
2348                          * Increment the head seq# also for the skipped slots.
2349                          */
2350                         tid_agg_rx->head_seq_num =
2351                                 (tid_agg_rx->head_seq_num + skipped) &
2352                                 SEQ_MASK;
2353                         skipped = 0;
2354                 }
2355         } else while (tid_agg_rx->reorder_buf[index]) {
2356                 ieee80211_release_reorder_frame(hw, tid_agg_rx, index);
2357                 index = seq_sub(tid_agg_rx->head_seq_num,
2358                         tid_agg_rx->ssn) % tid_agg_rx->buf_size;
2359         }
2360         return 1;
2361 }
2362
2363 static u8 ieee80211_rx_reorder_ampdu(struct ieee80211_local *local,
2364                                      struct sk_buff *skb)
2365 {
2366         struct ieee80211_hw *hw = &local->hw;
2367         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
2368         struct sta_info *sta;
2369         struct tid_ampdu_rx *tid_agg_rx;
2370         u16 sc;
2371         u16 mpdu_seq_num;
2372         u8 ret = 0;
2373         int tid;
2374
2375         sta = sta_info_get(local, hdr->addr2);
2376         if (!sta)
2377                 return ret;
2378
2379         /* filter the QoS data rx stream according to
2380          * STA/TID and check if this STA/TID is on aggregation */
2381         if (!ieee80211_is_data_qos(hdr->frame_control))
2382                 goto end_reorder;
2383
2384         tid = *ieee80211_get_qos_ctl(hdr) & IEEE80211_QOS_CTL_TID_MASK;
2385
2386         if (sta->ampdu_mlme.tid_state_rx[tid] != HT_AGG_STATE_OPERATIONAL)
2387                 goto end_reorder;
2388
2389         tid_agg_rx = sta->ampdu_mlme.tid_rx[tid];
2390
2391         /* qos null data frames are excluded */
2392         if (unlikely(hdr->frame_control & cpu_to_le16(IEEE80211_STYPE_NULLFUNC)))
2393                 goto end_reorder;
2394
2395         /* new un-ordered ampdu frame - process it */
2396
2397         /* reset session timer */
2398         if (tid_agg_rx->timeout)
2399                 mod_timer(&tid_agg_rx->session_timer,
2400                           TU_TO_EXP_TIME(tid_agg_rx->timeout));
2401
2402         /* if this mpdu is fragmented - terminate rx aggregation session */
2403         sc = le16_to_cpu(hdr->seq_ctrl);
2404         if (sc & IEEE80211_SCTL_FRAG) {
2405                 ieee80211_sta_stop_rx_ba_session(sta->sdata, sta->sta.addr,
2406                         tid, 0, WLAN_REASON_QSTA_REQUIRE_SETUP);
2407                 ret = 1;
2408                 goto end_reorder;
2409         }
2410
2411         /* according to mpdu sequence number deal with reordering buffer */
2412         mpdu_seq_num = (sc & IEEE80211_SCTL_SEQ) >> 4;
2413         ret = ieee80211_sta_manage_reorder_buf(hw, tid_agg_rx, skb,
2414                                                 mpdu_seq_num, 0);
2415  end_reorder:
2416         return ret;
2417 }
2418
2419 /*
2420  * This is the receive path handler. It is called by a low level driver when an
2421  * 802.11 MPDU is received from the hardware.
2422  */
2423 void __ieee80211_rx(struct ieee80211_hw *hw, struct sk_buff *skb)
2424 {
2425         struct ieee80211_local *local = hw_to_local(hw);
2426         struct ieee80211_rate *rate = NULL;
2427         struct ieee80211_supported_band *sband;
2428         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
2429
2430         if (status->band < 0 ||
2431             status->band >= IEEE80211_NUM_BANDS) {
2432                 WARN_ON(1);
2433                 return;
2434         }
2435
2436         sband = local->hw.wiphy->bands[status->band];
2437         if (!sband) {
2438                 WARN_ON(1);
2439                 return;
2440         }
2441
2442         if (status->flag & RX_FLAG_HT) {
2443                 /* rate_idx is MCS index */
2444                 if (WARN_ON(status->rate_idx < 0 ||
2445                             status->rate_idx >= 76))
2446                         return;
2447                 /* HT rates are not in the table - use the highest legacy rate
2448                  * for now since other parts of mac80211 may not yet be fully
2449                  * MCS aware. */
2450                 rate = &sband->bitrates[sband->n_bitrates - 1];
2451         } else {
2452                 if (WARN_ON(status->rate_idx < 0 ||
2453                             status->rate_idx >= sband->n_bitrates))
2454                         return;
2455                 rate = &sband->bitrates[status->rate_idx];
2456         }
2457
2458         /*
2459          * key references and virtual interfaces are protected using RCU
2460          * and this requires that we are in a read-side RCU section during
2461          * receive processing
2462          */
2463         rcu_read_lock();
2464
2465         /*
2466          * Frames with failed FCS/PLCP checksum are not returned,
2467          * all other frames are returned without radiotap header
2468          * if it was previously present.
2469          * Also, frames with less than 16 bytes are dropped.
2470          */
2471         skb = ieee80211_rx_monitor(local, skb, rate);
2472         if (!skb) {
2473                 rcu_read_unlock();
2474                 return;
2475         }
2476
2477         /*
2478          * In theory, the block ack reordering should happen after duplicate
2479          * removal (ieee80211_rx_h_check(), which is an RX handler). As such,
2480          * the call to ieee80211_rx_reorder_ampdu() should really be moved to
2481          * happen as a new RX handler between ieee80211_rx_h_check and
2482          * ieee80211_rx_h_decrypt. This cleanup may eventually happen, but for
2483          * the time being, the call can be here since RX reorder buf processing
2484          * will implicitly skip duplicates. We could, in theory at least,
2485          * process frames that ieee80211_rx_h_passive_scan would drop (e.g.,
2486          * frames from other than operational channel), but that should not
2487          * happen in normal networks.
2488          */
2489         if (!ieee80211_rx_reorder_ampdu(local, skb))
2490                 __ieee80211_rx_handle_packet(hw, skb, rate);
2491
2492         rcu_read_unlock();
2493 }
2494 EXPORT_SYMBOL(__ieee80211_rx);
2495
2496 /* This is a version of the rx handler that can be called from hard irq
2497  * context. Post the skb on the queue and schedule the tasklet */
2498 void ieee80211_rx_irqsafe(struct ieee80211_hw *hw, struct sk_buff *skb)
2499 {
2500         struct ieee80211_local *local = hw_to_local(hw);
2501
2502         BUILD_BUG_ON(sizeof(struct ieee80211_rx_status) > sizeof(skb->cb));
2503
2504         skb->pkt_type = IEEE80211_RX_MSG;
2505         skb_queue_tail(&local->skb_queue, skb);
2506         tasklet_schedule(&local->tasklet);
2507 }
2508 EXPORT_SYMBOL(ieee80211_rx_irqsafe);