net: Move && and || to end of previous line
[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 void ieee80211_release_reorder_frames(struct ieee80211_hw *hw,
31                                              struct tid_ampdu_rx *tid_agg_rx,
32                                              u16 head_seq_num);
33
34 /*
35  * monitor mode reception
36  *
37  * This function cleans up the SKB, i.e. it removes all the stuff
38  * only useful for monitoring.
39  */
40 static struct sk_buff *remove_monitor_info(struct ieee80211_local *local,
41                                            struct sk_buff *skb)
42 {
43         if (local->hw.flags & IEEE80211_HW_RX_INCLUDES_FCS) {
44                 if (likely(skb->len > FCS_LEN))
45                         skb_trim(skb, skb->len - FCS_LEN);
46                 else {
47                         /* driver bug */
48                         WARN_ON(1);
49                         dev_kfree_skb(skb);
50                         skb = NULL;
51                 }
52         }
53
54         return skb;
55 }
56
57 static inline int should_drop_frame(struct sk_buff *skb,
58                                     int present_fcs_len)
59 {
60         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
61         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
62
63         if (status->flag & (RX_FLAG_FAILED_FCS_CRC | RX_FLAG_FAILED_PLCP_CRC))
64                 return 1;
65         if (unlikely(skb->len < 16 + present_fcs_len))
66                 return 1;
67         if (ieee80211_is_ctl(hdr->frame_control) &&
68             !ieee80211_is_pspoll(hdr->frame_control) &&
69             !ieee80211_is_back_req(hdr->frame_control))
70                 return 1;
71         return 0;
72 }
73
74 static int
75 ieee80211_rx_radiotap_len(struct ieee80211_local *local,
76                           struct ieee80211_rx_status *status)
77 {
78         int len;
79
80         /* always present fields */
81         len = sizeof(struct ieee80211_radiotap_header) + 9;
82
83         if (status->flag & RX_FLAG_TSFT)
84                 len += 8;
85         if (local->hw.flags & IEEE80211_HW_SIGNAL_DBM)
86                 len += 1;
87         if (local->hw.flags & IEEE80211_HW_NOISE_DBM)
88                 len += 1;
89
90         if (len & 1) /* padding for RX_FLAGS if necessary */
91                 len++;
92
93         return len;
94 }
95
96 /*
97  * ieee80211_add_rx_radiotap_header - add radiotap header
98  *
99  * add a radiotap header containing all the fields which the hardware provided.
100  */
101 static void
102 ieee80211_add_rx_radiotap_header(struct ieee80211_local *local,
103                                  struct sk_buff *skb,
104                                  struct ieee80211_rate *rate,
105                                  int rtap_len)
106 {
107         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
108         struct ieee80211_radiotap_header *rthdr;
109         unsigned char *pos;
110         u16 rx_flags = 0;
111
112         rthdr = (struct ieee80211_radiotap_header *)skb_push(skb, rtap_len);
113         memset(rthdr, 0, rtap_len);
114
115         /* radiotap header, set always present flags */
116         rthdr->it_present =
117                 cpu_to_le32((1 << IEEE80211_RADIOTAP_FLAGS) |
118                             (1 << IEEE80211_RADIOTAP_CHANNEL) |
119                             (1 << IEEE80211_RADIOTAP_ANTENNA) |
120                             (1 << IEEE80211_RADIOTAP_RX_FLAGS));
121         rthdr->it_len = cpu_to_le16(rtap_len);
122
123         pos = (unsigned char *)(rthdr+1);
124
125         /* the order of the following fields is important */
126
127         /* IEEE80211_RADIOTAP_TSFT */
128         if (status->flag & RX_FLAG_TSFT) {
129                 put_unaligned_le64(status->mactime, pos);
130                 rthdr->it_present |=
131                         cpu_to_le32(1 << IEEE80211_RADIOTAP_TSFT);
132                 pos += 8;
133         }
134
135         /* IEEE80211_RADIOTAP_FLAGS */
136         if (local->hw.flags & IEEE80211_HW_RX_INCLUDES_FCS)
137                 *pos |= IEEE80211_RADIOTAP_F_FCS;
138         if (status->flag & (RX_FLAG_FAILED_FCS_CRC | RX_FLAG_FAILED_PLCP_CRC))
139                 *pos |= IEEE80211_RADIOTAP_F_BADFCS;
140         if (status->flag & RX_FLAG_SHORTPRE)
141                 *pos |= IEEE80211_RADIOTAP_F_SHORTPRE;
142         pos++;
143
144         /* IEEE80211_RADIOTAP_RATE */
145         if (status->flag & RX_FLAG_HT) {
146                 /*
147                  * TODO: add following information into radiotap header once
148                  * suitable fields are defined for it:
149                  * - MCS index (status->rate_idx)
150                  * - HT40 (status->flag & RX_FLAG_40MHZ)
151                  * - short-GI (status->flag & RX_FLAG_SHORT_GI)
152                  */
153                 *pos = 0;
154         } else {
155                 rthdr->it_present |= cpu_to_le32(1 << IEEE80211_RADIOTAP_RATE);
156                 *pos = rate->bitrate / 5;
157         }
158         pos++;
159
160         /* IEEE80211_RADIOTAP_CHANNEL */
161         put_unaligned_le16(status->freq, pos);
162         pos += 2;
163         if (status->band == IEEE80211_BAND_5GHZ)
164                 put_unaligned_le16(IEEE80211_CHAN_OFDM | IEEE80211_CHAN_5GHZ,
165                                    pos);
166         else if (status->flag & RX_FLAG_HT)
167                 put_unaligned_le16(IEEE80211_CHAN_DYN | IEEE80211_CHAN_2GHZ,
168                                    pos);
169         else if (rate->flags & IEEE80211_RATE_ERP_G)
170                 put_unaligned_le16(IEEE80211_CHAN_OFDM | IEEE80211_CHAN_2GHZ,
171                                    pos);
172         else
173                 put_unaligned_le16(IEEE80211_CHAN_CCK | IEEE80211_CHAN_2GHZ,
174                                    pos);
175         pos += 2;
176
177         /* IEEE80211_RADIOTAP_DBM_ANTSIGNAL */
178         if (local->hw.flags & IEEE80211_HW_SIGNAL_DBM) {
179                 *pos = status->signal;
180                 rthdr->it_present |=
181                         cpu_to_le32(1 << IEEE80211_RADIOTAP_DBM_ANTSIGNAL);
182                 pos++;
183         }
184
185         /* IEEE80211_RADIOTAP_DBM_ANTNOISE */
186         if (local->hw.flags & IEEE80211_HW_NOISE_DBM) {
187                 *pos = status->noise;
188                 rthdr->it_present |=
189                         cpu_to_le32(1 << IEEE80211_RADIOTAP_DBM_ANTNOISE);
190                 pos++;
191         }
192
193         /* IEEE80211_RADIOTAP_LOCK_QUALITY is missing */
194
195         /* IEEE80211_RADIOTAP_ANTENNA */
196         *pos = status->antenna;
197         pos++;
198
199         /* IEEE80211_RADIOTAP_DB_ANTNOISE is not used */
200
201         /* IEEE80211_RADIOTAP_RX_FLAGS */
202         /* ensure 2 byte alignment for the 2 byte field as required */
203         if ((pos - (u8 *)rthdr) & 1)
204                 pos++;
205         if (status->flag & RX_FLAG_FAILED_PLCP_CRC)
206                 rx_flags |= IEEE80211_RADIOTAP_F_RX_BADPLCP;
207         put_unaligned_le16(rx_flags, pos);
208         pos += 2;
209 }
210
211 /*
212  * This function copies a received frame to all monitor interfaces and
213  * returns a cleaned-up SKB that no longer includes the FCS nor the
214  * radiotap header the driver might have added.
215  */
216 static struct sk_buff *
217 ieee80211_rx_monitor(struct ieee80211_local *local, struct sk_buff *origskb,
218                      struct ieee80211_rate *rate)
219 {
220         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(origskb);
221         struct ieee80211_sub_if_data *sdata;
222         int needed_headroom = 0;
223         struct sk_buff *skb, *skb2;
224         struct net_device *prev_dev = NULL;
225         int present_fcs_len = 0;
226
227         /*
228          * First, we may need to make a copy of the skb because
229          *  (1) we need to modify it for radiotap (if not present), and
230          *  (2) the other RX handlers will modify the skb we got.
231          *
232          * We don't need to, of course, if we aren't going to return
233          * the SKB because it has a bad FCS/PLCP checksum.
234          */
235
236         /* room for the radiotap header based on driver features */
237         needed_headroom = ieee80211_rx_radiotap_len(local, status);
238
239         if (local->hw.flags & IEEE80211_HW_RX_INCLUDES_FCS)
240                 present_fcs_len = FCS_LEN;
241
242         if (!local->monitors) {
243                 if (should_drop_frame(origskb, present_fcs_len)) {
244                         dev_kfree_skb(origskb);
245                         return NULL;
246                 }
247
248                 return remove_monitor_info(local, origskb);
249         }
250
251         if (should_drop_frame(origskb, present_fcs_len)) {
252                 /* only need to expand headroom if necessary */
253                 skb = origskb;
254                 origskb = NULL;
255
256                 /*
257                  * This shouldn't trigger often because most devices have an
258                  * RX header they pull before we get here, and that should
259                  * be big enough for our radiotap information. We should
260                  * probably export the length to drivers so that we can have
261                  * them allocate enough headroom to start with.
262                  */
263                 if (skb_headroom(skb) < needed_headroom &&
264                     pskb_expand_head(skb, needed_headroom, 0, GFP_ATOMIC)) {
265                         dev_kfree_skb(skb);
266                         return NULL;
267                 }
268         } else {
269                 /*
270                  * Need to make a copy and possibly remove radiotap header
271                  * and FCS from the original.
272                  */
273                 skb = skb_copy_expand(origskb, needed_headroom, 0, GFP_ATOMIC);
274
275                 origskb = remove_monitor_info(local, origskb);
276
277                 if (!skb)
278                         return origskb;
279         }
280
281         /* prepend radiotap information */
282         ieee80211_add_rx_radiotap_header(local, skb, rate, needed_headroom);
283
284         skb_reset_mac_header(skb);
285         skb->ip_summed = CHECKSUM_UNNECESSARY;
286         skb->pkt_type = PACKET_OTHERHOST;
287         skb->protocol = htons(ETH_P_802_2);
288
289         list_for_each_entry_rcu(sdata, &local->interfaces, list) {
290                 if (!netif_running(sdata->dev))
291                         continue;
292
293                 if (sdata->vif.type != NL80211_IFTYPE_MONITOR)
294                         continue;
295
296                 if (sdata->u.mntr_flags & MONITOR_FLAG_COOK_FRAMES)
297                         continue;
298
299                 if (prev_dev) {
300                         skb2 = skb_clone(skb, GFP_ATOMIC);
301                         if (skb2) {
302                                 skb2->dev = prev_dev;
303                                 netif_rx(skb2);
304                         }
305                 }
306
307                 prev_dev = sdata->dev;
308                 sdata->dev->stats.rx_packets++;
309                 sdata->dev->stats.rx_bytes += skb->len;
310         }
311
312         if (prev_dev) {
313                 skb->dev = prev_dev;
314                 netif_rx(skb);
315         } else
316                 dev_kfree_skb(skb);
317
318         return origskb;
319 }
320
321
322 static void ieee80211_parse_qos(struct ieee80211_rx_data *rx)
323 {
324         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
325         int tid;
326
327         /* does the frame have a qos control field? */
328         if (ieee80211_is_data_qos(hdr->frame_control)) {
329                 u8 *qc = ieee80211_get_qos_ctl(hdr);
330                 /* frame has qos control */
331                 tid = *qc & IEEE80211_QOS_CTL_TID_MASK;
332                 if (*qc & IEEE80211_QOS_CONTROL_A_MSDU_PRESENT)
333                         rx->flags |= IEEE80211_RX_AMSDU;
334                 else
335                         rx->flags &= ~IEEE80211_RX_AMSDU;
336         } else {
337                 /*
338                  * IEEE 802.11-2007, 7.1.3.4.1 ("Sequence Number field"):
339                  *
340                  *      Sequence numbers for management frames, QoS data
341                  *      frames with a broadcast/multicast address in the
342                  *      Address 1 field, and all non-QoS data frames sent
343                  *      by QoS STAs are assigned using an additional single
344                  *      modulo-4096 counter, [...]
345                  *
346                  * We also use that counter for non-QoS STAs.
347                  */
348                 tid = NUM_RX_DATA_QUEUES - 1;
349         }
350
351         rx->queue = tid;
352         /* Set skb->priority to 1d tag if highest order bit of TID is not set.
353          * For now, set skb->priority to 0 for other cases. */
354         rx->skb->priority = (tid > 7) ? 0 : tid;
355 }
356
357 /**
358  * DOC: Packet alignment
359  *
360  * Drivers always need to pass packets that are aligned to two-byte boundaries
361  * to the stack.
362  *
363  * Additionally, should, if possible, align the payload data in a way that
364  * guarantees that the contained IP header is aligned to a four-byte
365  * boundary. In the case of regular frames, this simply means aligning the
366  * payload to a four-byte boundary (because either the IP header is directly
367  * contained, or IV/RFC1042 headers that have a length divisible by four are
368  * in front of it).
369  *
370  * With A-MSDU frames, however, the payload data address must yield two modulo
371  * four because there are 14-byte 802.3 headers within the A-MSDU frames that
372  * push the IP header further back to a multiple of four again. Thankfully, the
373  * specs were sane enough this time around to require padding each A-MSDU
374  * subframe to a length that is a multiple of four.
375  *
376  * Padding like Atheros hardware adds which is inbetween the 802.11 header and
377  * the payload is not supported, the driver is required to move the 802.11
378  * header to be directly in front of the payload in that case.
379  */
380 static void ieee80211_verify_alignment(struct ieee80211_rx_data *rx)
381 {
382         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
383         int hdrlen;
384
385 #ifndef CONFIG_MAC80211_DEBUG_PACKET_ALIGNMENT
386         return;
387 #endif
388
389         if (WARN_ONCE((unsigned long)rx->skb->data & 1,
390                       "unaligned packet at 0x%p\n", rx->skb->data))
391                 return;
392
393         if (!ieee80211_is_data_present(hdr->frame_control))
394                 return;
395
396         hdrlen = ieee80211_hdrlen(hdr->frame_control);
397         if (rx->flags & IEEE80211_RX_AMSDU)
398                 hdrlen += ETH_HLEN;
399         WARN_ONCE(((unsigned long)(rx->skb->data + hdrlen)) & 3,
400                   "unaligned IP payload at 0x%p\n", rx->skb->data + hdrlen);
401 }
402
403
404 /* rx handlers */
405
406 static ieee80211_rx_result debug_noinline
407 ieee80211_rx_h_passive_scan(struct ieee80211_rx_data *rx)
408 {
409         struct ieee80211_local *local = rx->local;
410         struct sk_buff *skb = rx->skb;
411
412         if (unlikely(test_bit(SCAN_HW_SCANNING, &local->scanning)))
413                 return ieee80211_scan_rx(rx->sdata, skb);
414
415         if (unlikely(test_bit(SCAN_SW_SCANNING, &local->scanning) &&
416                      (rx->flags & IEEE80211_RX_IN_SCAN))) {
417                 /* drop all the other packets during a software scan anyway */
418                 if (ieee80211_scan_rx(rx->sdata, skb) != RX_QUEUED)
419                         dev_kfree_skb(skb);
420                 return RX_QUEUED;
421         }
422
423         if (unlikely(rx->flags & IEEE80211_RX_IN_SCAN)) {
424                 /* scanning finished during invoking of handlers */
425                 I802_DEBUG_INC(local->rx_handlers_drop_passive_scan);
426                 return RX_DROP_UNUSABLE;
427         }
428
429         return RX_CONTINUE;
430 }
431
432
433 static int ieee80211_is_unicast_robust_mgmt_frame(struct sk_buff *skb)
434 {
435         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
436
437         if (skb->len < 24 || is_multicast_ether_addr(hdr->addr1))
438                 return 0;
439
440         return ieee80211_is_robust_mgmt_frame(hdr);
441 }
442
443
444 static int ieee80211_is_multicast_robust_mgmt_frame(struct sk_buff *skb)
445 {
446         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
447
448         if (skb->len < 24 || !is_multicast_ether_addr(hdr->addr1))
449                 return 0;
450
451         return ieee80211_is_robust_mgmt_frame(hdr);
452 }
453
454
455 /* Get the BIP key index from MMIE; return -1 if this is not a BIP frame */
456 static int ieee80211_get_mmie_keyidx(struct sk_buff *skb)
457 {
458         struct ieee80211_mgmt *hdr = (struct ieee80211_mgmt *) skb->data;
459         struct ieee80211_mmie *mmie;
460
461         if (skb->len < 24 + sizeof(*mmie) ||
462             !is_multicast_ether_addr(hdr->da))
463                 return -1;
464
465         if (!ieee80211_is_robust_mgmt_frame((struct ieee80211_hdr *) hdr))
466                 return -1; /* not a robust management frame */
467
468         mmie = (struct ieee80211_mmie *)
469                 (skb->data + skb->len - sizeof(*mmie));
470         if (mmie->element_id != WLAN_EID_MMIE ||
471             mmie->length != sizeof(*mmie) - 2)
472                 return -1;
473
474         return le16_to_cpu(mmie->key_id);
475 }
476
477
478 static ieee80211_rx_result
479 ieee80211_rx_mesh_check(struct ieee80211_rx_data *rx)
480 {
481         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
482         unsigned int hdrlen = ieee80211_hdrlen(hdr->frame_control);
483         char *dev_addr = rx->sdata->dev->dev_addr;
484
485         if (ieee80211_is_data(hdr->frame_control)) {
486                 if (is_multicast_ether_addr(hdr->addr1)) {
487                         if (ieee80211_has_tods(hdr->frame_control) ||
488                                 !ieee80211_has_fromds(hdr->frame_control))
489                                 return RX_DROP_MONITOR;
490                         if (memcmp(hdr->addr3, dev_addr, ETH_ALEN) == 0)
491                                 return RX_DROP_MONITOR;
492                 } else {
493                         if (!ieee80211_has_a4(hdr->frame_control))
494                                 return RX_DROP_MONITOR;
495                         if (memcmp(hdr->addr4, dev_addr, ETH_ALEN) == 0)
496                                 return RX_DROP_MONITOR;
497                 }
498         }
499
500         /* If there is not an established peer link and this is not a peer link
501          * establisment frame, beacon or probe, drop the frame.
502          */
503
504         if (!rx->sta || sta_plink_state(rx->sta) != PLINK_ESTAB) {
505                 struct ieee80211_mgmt *mgmt;
506
507                 if (!ieee80211_is_mgmt(hdr->frame_control))
508                         return RX_DROP_MONITOR;
509
510                 if (ieee80211_is_action(hdr->frame_control)) {
511                         mgmt = (struct ieee80211_mgmt *)hdr;
512                         if (mgmt->u.action.category != MESH_PLINK_CATEGORY)
513                                 return RX_DROP_MONITOR;
514                         return RX_CONTINUE;
515                 }
516
517                 if (ieee80211_is_probe_req(hdr->frame_control) ||
518                     ieee80211_is_probe_resp(hdr->frame_control) ||
519                     ieee80211_is_beacon(hdr->frame_control))
520                         return RX_CONTINUE;
521
522                 return RX_DROP_MONITOR;
523
524         }
525
526 #define msh_h_get(h, l) ((struct ieee80211s_hdr *) ((u8 *)h + l))
527
528         if (ieee80211_is_data(hdr->frame_control) &&
529             is_multicast_ether_addr(hdr->addr1) &&
530             mesh_rmc_check(hdr->addr3, msh_h_get(hdr, hdrlen), rx->sdata))
531                 return RX_DROP_MONITOR;
532 #undef msh_h_get
533
534         return RX_CONTINUE;
535 }
536
537
538 static ieee80211_rx_result debug_noinline
539 ieee80211_rx_h_check(struct ieee80211_rx_data *rx)
540 {
541         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
542
543         /* Drop duplicate 802.11 retransmissions (IEEE 802.11 Chap. 9.2.9) */
544         if (rx->sta && !is_multicast_ether_addr(hdr->addr1)) {
545                 if (unlikely(ieee80211_has_retry(hdr->frame_control) &&
546                              rx->sta->last_seq_ctrl[rx->queue] ==
547                              hdr->seq_ctrl)) {
548                         if (rx->flags & IEEE80211_RX_RA_MATCH) {
549                                 rx->local->dot11FrameDuplicateCount++;
550                                 rx->sta->num_duplicates++;
551                         }
552                         return RX_DROP_MONITOR;
553                 } else
554                         rx->sta->last_seq_ctrl[rx->queue] = hdr->seq_ctrl;
555         }
556
557         if (unlikely(rx->skb->len < 16)) {
558                 I802_DEBUG_INC(rx->local->rx_handlers_drop_short);
559                 return RX_DROP_MONITOR;
560         }
561
562         /* Drop disallowed frame classes based on STA auth/assoc state;
563          * IEEE 802.11, Chap 5.5.
564          *
565          * mac80211 filters only based on association state, i.e. it drops
566          * Class 3 frames from not associated stations. hostapd sends
567          * deauth/disassoc frames when needed. In addition, hostapd is
568          * responsible for filtering on both auth and assoc states.
569          */
570
571         if (ieee80211_vif_is_mesh(&rx->sdata->vif))
572                 return ieee80211_rx_mesh_check(rx);
573
574         if (unlikely((ieee80211_is_data(hdr->frame_control) ||
575                       ieee80211_is_pspoll(hdr->frame_control)) &&
576                      rx->sdata->vif.type != NL80211_IFTYPE_ADHOC &&
577                      (!rx->sta || !test_sta_flags(rx->sta, WLAN_STA_ASSOC)))) {
578                 if ((!ieee80211_has_fromds(hdr->frame_control) &&
579                      !ieee80211_has_tods(hdr->frame_control) &&
580                      ieee80211_is_data(hdr->frame_control)) ||
581                     !(rx->flags & IEEE80211_RX_RA_MATCH)) {
582                         /* Drop IBSS frames and frames for other hosts
583                          * silently. */
584                         return RX_DROP_MONITOR;
585                 }
586
587                 return RX_DROP_MONITOR;
588         }
589
590         return RX_CONTINUE;
591 }
592
593
594 static ieee80211_rx_result debug_noinline
595 ieee80211_rx_h_decrypt(struct ieee80211_rx_data *rx)
596 {
597         struct sk_buff *skb = rx->skb;
598         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
599         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
600         int keyidx;
601         int hdrlen;
602         ieee80211_rx_result result = RX_DROP_UNUSABLE;
603         struct ieee80211_key *stakey = NULL;
604         int mmie_keyidx = -1;
605
606         /*
607          * Key selection 101
608          *
609          * There are four types of keys:
610          *  - GTK (group keys)
611          *  - IGTK (group keys for management frames)
612          *  - PTK (pairwise keys)
613          *  - STK (station-to-station pairwise keys)
614          *
615          * When selecting a key, we have to distinguish between multicast
616          * (including broadcast) and unicast frames, the latter can only
617          * use PTKs and STKs while the former always use GTKs and IGTKs.
618          * Unless, of course, actual WEP keys ("pre-RSNA") are used, then
619          * unicast frames can also use key indices like GTKs. Hence, if we
620          * don't have a PTK/STK we check the key index for a WEP key.
621          *
622          * Note that in a regular BSS, multicast frames are sent by the
623          * AP only, associated stations unicast the frame to the AP first
624          * which then multicasts it on their behalf.
625          *
626          * There is also a slight problem in IBSS mode: GTKs are negotiated
627          * with each station, that is something we don't currently handle.
628          * The spec seems to expect that one negotiates the same key with
629          * every station but there's no such requirement; VLANs could be
630          * possible.
631          */
632
633         /*
634          * No point in finding a key and decrypting if the frame is neither
635          * addressed to us nor a multicast frame.
636          */
637         if (!(rx->flags & IEEE80211_RX_RA_MATCH))
638                 return RX_CONTINUE;
639
640         if (rx->sta)
641                 stakey = rcu_dereference(rx->sta->key);
642
643         if (!ieee80211_has_protected(hdr->frame_control))
644                 mmie_keyidx = ieee80211_get_mmie_keyidx(rx->skb);
645
646         if (!is_multicast_ether_addr(hdr->addr1) && stakey) {
647                 rx->key = stakey;
648                 /* Skip decryption if the frame is not protected. */
649                 if (!ieee80211_has_protected(hdr->frame_control))
650                         return RX_CONTINUE;
651         } else if (mmie_keyidx >= 0) {
652                 /* Broadcast/multicast robust management frame / BIP */
653                 if ((status->flag & RX_FLAG_DECRYPTED) &&
654                     (status->flag & RX_FLAG_IV_STRIPPED))
655                         return RX_CONTINUE;
656
657                 if (mmie_keyidx < NUM_DEFAULT_KEYS ||
658                     mmie_keyidx >= NUM_DEFAULT_KEYS + NUM_DEFAULT_MGMT_KEYS)
659                         return RX_DROP_MONITOR; /* unexpected BIP keyidx */
660                 rx->key = rcu_dereference(rx->sdata->keys[mmie_keyidx]);
661         } else if (!ieee80211_has_protected(hdr->frame_control)) {
662                 /*
663                  * The frame was not protected, so skip decryption. However, we
664                  * need to set rx->key if there is a key that could have been
665                  * used so that the frame may be dropped if encryption would
666                  * have been expected.
667                  */
668                 struct ieee80211_key *key = NULL;
669                 if (ieee80211_is_mgmt(hdr->frame_control) &&
670                     is_multicast_ether_addr(hdr->addr1) &&
671                     (key = rcu_dereference(rx->sdata->default_mgmt_key)))
672                         rx->key = key;
673                 else if ((key = rcu_dereference(rx->sdata->default_key)))
674                         rx->key = key;
675                 return RX_CONTINUE;
676         } else {
677                 /*
678                  * The device doesn't give us the IV so we won't be
679                  * able to look up the key. That's ok though, we
680                  * don't need to decrypt the frame, we just won't
681                  * be able to keep statistics accurate.
682                  * Except for key threshold notifications, should
683                  * we somehow allow the driver to tell us which key
684                  * the hardware used if this flag is set?
685                  */
686                 if ((status->flag & RX_FLAG_DECRYPTED) &&
687                     (status->flag & RX_FLAG_IV_STRIPPED))
688                         return RX_CONTINUE;
689
690                 hdrlen = ieee80211_hdrlen(hdr->frame_control);
691
692                 if (rx->skb->len < 8 + hdrlen)
693                         return RX_DROP_UNUSABLE; /* TODO: count this? */
694
695                 /*
696                  * no need to call ieee80211_wep_get_keyidx,
697                  * it verifies a bunch of things we've done already
698                  */
699                 keyidx = rx->skb->data[hdrlen + 3] >> 6;
700
701                 rx->key = rcu_dereference(rx->sdata->keys[keyidx]);
702
703                 /*
704                  * RSNA-protected unicast frames should always be sent with
705                  * pairwise or station-to-station keys, but for WEP we allow
706                  * using a key index as well.
707                  */
708                 if (rx->key && rx->key->conf.alg != ALG_WEP &&
709                     !is_multicast_ether_addr(hdr->addr1))
710                         rx->key = NULL;
711         }
712
713         if (rx->key) {
714                 rx->key->tx_rx_count++;
715                 /* TODO: add threshold stuff again */
716         } else {
717                 return RX_DROP_MONITOR;
718         }
719
720         /* Check for weak IVs if possible */
721         if (rx->sta && rx->key->conf.alg == ALG_WEP &&
722             ieee80211_is_data(hdr->frame_control) &&
723             (!(status->flag & RX_FLAG_IV_STRIPPED) ||
724              !(status->flag & RX_FLAG_DECRYPTED)) &&
725             ieee80211_wep_is_weak_iv(rx->skb, rx->key))
726                 rx->sta->wep_weak_iv_count++;
727
728         switch (rx->key->conf.alg) {
729         case ALG_WEP:
730                 result = ieee80211_crypto_wep_decrypt(rx);
731                 break;
732         case ALG_TKIP:
733                 result = ieee80211_crypto_tkip_decrypt(rx);
734                 break;
735         case ALG_CCMP:
736                 result = ieee80211_crypto_ccmp_decrypt(rx);
737                 break;
738         case ALG_AES_CMAC:
739                 result = ieee80211_crypto_aes_cmac_decrypt(rx);
740                 break;
741         }
742
743         /* either the frame has been decrypted or will be dropped */
744         status->flag |= RX_FLAG_DECRYPTED;
745
746         return result;
747 }
748
749 static ieee80211_rx_result debug_noinline
750 ieee80211_rx_h_check_more_data(struct ieee80211_rx_data *rx)
751 {
752         struct ieee80211_local *local;
753         struct ieee80211_hdr *hdr;
754         struct sk_buff *skb;
755
756         local = rx->local;
757         skb = rx->skb;
758         hdr = (struct ieee80211_hdr *) skb->data;
759
760         if (!local->pspolling)
761                 return RX_CONTINUE;
762
763         if (!ieee80211_has_fromds(hdr->frame_control))
764                 /* this is not from AP */
765                 return RX_CONTINUE;
766
767         if (!ieee80211_is_data(hdr->frame_control))
768                 return RX_CONTINUE;
769
770         if (!ieee80211_has_moredata(hdr->frame_control)) {
771                 /* AP has no more frames buffered for us */
772                 local->pspolling = false;
773                 return RX_CONTINUE;
774         }
775
776         /* more data bit is set, let's request a new frame from the AP */
777         ieee80211_send_pspoll(local, rx->sdata);
778
779         return RX_CONTINUE;
780 }
781
782 static void ap_sta_ps_start(struct sta_info *sta)
783 {
784         struct ieee80211_sub_if_data *sdata = sta->sdata;
785         struct ieee80211_local *local = sdata->local;
786
787         atomic_inc(&sdata->bss->num_sta_ps);
788         set_sta_flags(sta, WLAN_STA_PS_STA);
789         drv_sta_notify(local, &sdata->vif, STA_NOTIFY_SLEEP, &sta->sta);
790 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
791         printk(KERN_DEBUG "%s: STA %pM aid %d enters power save mode\n",
792                sdata->dev->name, sta->sta.addr, sta->sta.aid);
793 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
794 }
795
796 static void ap_sta_ps_end(struct sta_info *sta)
797 {
798         struct ieee80211_sub_if_data *sdata = sta->sdata;
799
800         atomic_dec(&sdata->bss->num_sta_ps);
801
802         clear_sta_flags(sta, WLAN_STA_PS_STA);
803
804 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
805         printk(KERN_DEBUG "%s: STA %pM aid %d exits power save mode\n",
806                sdata->dev->name, sta->sta.addr, sta->sta.aid);
807 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
808
809         if (test_sta_flags(sta, WLAN_STA_PS_DRIVER)) {
810 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
811                 printk(KERN_DEBUG "%s: STA %pM aid %d driver-ps-blocked\n",
812                        sdata->dev->name, sta->sta.addr, sta->sta.aid);
813 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
814                 return;
815         }
816
817         ieee80211_sta_ps_deliver_wakeup(sta);
818 }
819
820 static ieee80211_rx_result debug_noinline
821 ieee80211_rx_h_sta_process(struct ieee80211_rx_data *rx)
822 {
823         struct sta_info *sta = rx->sta;
824         struct sk_buff *skb = rx->skb;
825         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
826         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
827
828         if (!sta)
829                 return RX_CONTINUE;
830
831         /*
832          * Update last_rx only for IBSS packets which are for the current
833          * BSSID to avoid keeping the current IBSS network alive in cases
834          * where other STAs start using different BSSID.
835          */
836         if (rx->sdata->vif.type == NL80211_IFTYPE_ADHOC) {
837                 u8 *bssid = ieee80211_get_bssid(hdr, rx->skb->len,
838                                                 NL80211_IFTYPE_ADHOC);
839                 if (compare_ether_addr(bssid, rx->sdata->u.ibss.bssid) == 0)
840                         sta->last_rx = jiffies;
841         } else if (!is_multicast_ether_addr(hdr->addr1)) {
842                 /*
843                  * Mesh beacons will update last_rx when if they are found to
844                  * match the current local configuration when processed.
845                  */
846                 sta->last_rx = jiffies;
847         }
848
849         if (!(rx->flags & IEEE80211_RX_RA_MATCH))
850                 return RX_CONTINUE;
851
852         if (rx->sdata->vif.type == NL80211_IFTYPE_STATION)
853                 ieee80211_sta_rx_notify(rx->sdata, hdr);
854
855         sta->rx_fragments++;
856         sta->rx_bytes += rx->skb->len;
857         sta->last_signal = status->signal;
858         sta->last_noise = status->noise;
859
860         /*
861          * Change STA power saving mode only at the end of a frame
862          * exchange sequence.
863          */
864         if (!ieee80211_has_morefrags(hdr->frame_control) &&
865             (rx->sdata->vif.type == NL80211_IFTYPE_AP ||
866              rx->sdata->vif.type == NL80211_IFTYPE_AP_VLAN)) {
867                 if (test_sta_flags(sta, WLAN_STA_PS_STA)) {
868                         /*
869                          * Ignore doze->wake transitions that are
870                          * indicated by non-data frames, the standard
871                          * is unclear here, but for example going to
872                          * PS mode and then scanning would cause a
873                          * doze->wake transition for the probe request,
874                          * and that is clearly undesirable.
875                          */
876                         if (ieee80211_is_data(hdr->frame_control) &&
877                             !ieee80211_has_pm(hdr->frame_control))
878                                 ap_sta_ps_end(sta);
879                 } else {
880                         if (ieee80211_has_pm(hdr->frame_control))
881                                 ap_sta_ps_start(sta);
882                 }
883         }
884
885         /*
886          * Drop (qos-)data::nullfunc frames silently, since they
887          * are used only to control station power saving mode.
888          */
889         if (ieee80211_is_nullfunc(hdr->frame_control) ||
890             ieee80211_is_qos_nullfunc(hdr->frame_control)) {
891                 I802_DEBUG_INC(rx->local->rx_handlers_drop_nullfunc);
892                 /*
893                  * Update counter and free packet here to avoid
894                  * counting this as a dropped packed.
895                  */
896                 sta->rx_packets++;
897                 dev_kfree_skb(rx->skb);
898                 return RX_QUEUED;
899         }
900
901         return RX_CONTINUE;
902 } /* ieee80211_rx_h_sta_process */
903
904 static inline struct ieee80211_fragment_entry *
905 ieee80211_reassemble_add(struct ieee80211_sub_if_data *sdata,
906                          unsigned int frag, unsigned int seq, int rx_queue,
907                          struct sk_buff **skb)
908 {
909         struct ieee80211_fragment_entry *entry;
910         int idx;
911
912         idx = sdata->fragment_next;
913         entry = &sdata->fragments[sdata->fragment_next++];
914         if (sdata->fragment_next >= IEEE80211_FRAGMENT_MAX)
915                 sdata->fragment_next = 0;
916
917         if (!skb_queue_empty(&entry->skb_list)) {
918 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG
919                 struct ieee80211_hdr *hdr =
920                         (struct ieee80211_hdr *) entry->skb_list.next->data;
921                 printk(KERN_DEBUG "%s: RX reassembly removed oldest "
922                        "fragment entry (idx=%d age=%lu seq=%d last_frag=%d "
923                        "addr1=%pM addr2=%pM\n",
924                        sdata->dev->name, idx,
925                        jiffies - entry->first_frag_time, entry->seq,
926                        entry->last_frag, hdr->addr1, hdr->addr2);
927 #endif
928                 __skb_queue_purge(&entry->skb_list);
929         }
930
931         __skb_queue_tail(&entry->skb_list, *skb); /* no need for locking */
932         *skb = NULL;
933         entry->first_frag_time = jiffies;
934         entry->seq = seq;
935         entry->rx_queue = rx_queue;
936         entry->last_frag = frag;
937         entry->ccmp = 0;
938         entry->extra_len = 0;
939
940         return entry;
941 }
942
943 static inline struct ieee80211_fragment_entry *
944 ieee80211_reassemble_find(struct ieee80211_sub_if_data *sdata,
945                           unsigned int frag, unsigned int seq,
946                           int rx_queue, struct ieee80211_hdr *hdr)
947 {
948         struct ieee80211_fragment_entry *entry;
949         int i, idx;
950
951         idx = sdata->fragment_next;
952         for (i = 0; i < IEEE80211_FRAGMENT_MAX; i++) {
953                 struct ieee80211_hdr *f_hdr;
954
955                 idx--;
956                 if (idx < 0)
957                         idx = IEEE80211_FRAGMENT_MAX - 1;
958
959                 entry = &sdata->fragments[idx];
960                 if (skb_queue_empty(&entry->skb_list) || entry->seq != seq ||
961                     entry->rx_queue != rx_queue ||
962                     entry->last_frag + 1 != frag)
963                         continue;
964
965                 f_hdr = (struct ieee80211_hdr *)entry->skb_list.next->data;
966
967                 /*
968                  * Check ftype and addresses are equal, else check next fragment
969                  */
970                 if (((hdr->frame_control ^ f_hdr->frame_control) &
971                      cpu_to_le16(IEEE80211_FCTL_FTYPE)) ||
972                     compare_ether_addr(hdr->addr1, f_hdr->addr1) != 0 ||
973                     compare_ether_addr(hdr->addr2, f_hdr->addr2) != 0)
974                         continue;
975
976                 if (time_after(jiffies, entry->first_frag_time + 2 * HZ)) {
977                         __skb_queue_purge(&entry->skb_list);
978                         continue;
979                 }
980                 return entry;
981         }
982
983         return NULL;
984 }
985
986 static ieee80211_rx_result debug_noinline
987 ieee80211_rx_h_defragment(struct ieee80211_rx_data *rx)
988 {
989         struct ieee80211_hdr *hdr;
990         u16 sc;
991         __le16 fc;
992         unsigned int frag, seq;
993         struct ieee80211_fragment_entry *entry;
994         struct sk_buff *skb;
995
996         hdr = (struct ieee80211_hdr *)rx->skb->data;
997         fc = hdr->frame_control;
998         sc = le16_to_cpu(hdr->seq_ctrl);
999         frag = sc & IEEE80211_SCTL_FRAG;
1000
1001         if (likely((!ieee80211_has_morefrags(fc) && frag == 0) ||
1002                    (rx->skb)->len < 24 ||
1003                    is_multicast_ether_addr(hdr->addr1))) {
1004                 /* not fragmented */
1005                 goto out;
1006         }
1007         I802_DEBUG_INC(rx->local->rx_handlers_fragments);
1008
1009         seq = (sc & IEEE80211_SCTL_SEQ) >> 4;
1010
1011         if (frag == 0) {
1012                 /* This is the first fragment of a new frame. */
1013                 entry = ieee80211_reassemble_add(rx->sdata, frag, seq,
1014                                                  rx->queue, &(rx->skb));
1015                 if (rx->key && rx->key->conf.alg == ALG_CCMP &&
1016                     ieee80211_has_protected(fc)) {
1017                         /* Store CCMP PN so that we can verify that the next
1018                          * fragment has a sequential PN value. */
1019                         entry->ccmp = 1;
1020                         memcpy(entry->last_pn,
1021                                rx->key->u.ccmp.rx_pn[rx->queue],
1022                                CCMP_PN_LEN);
1023                 }
1024                 return RX_QUEUED;
1025         }
1026
1027         /* This is a fragment for a frame that should already be pending in
1028          * fragment cache. Add this fragment to the end of the pending entry.
1029          */
1030         entry = ieee80211_reassemble_find(rx->sdata, frag, seq, rx->queue, hdr);
1031         if (!entry) {
1032                 I802_DEBUG_INC(rx->local->rx_handlers_drop_defrag);
1033                 return RX_DROP_MONITOR;
1034         }
1035
1036         /* Verify that MPDUs within one MSDU have sequential PN values.
1037          * (IEEE 802.11i, 8.3.3.4.5) */
1038         if (entry->ccmp) {
1039                 int i;
1040                 u8 pn[CCMP_PN_LEN], *rpn;
1041                 if (!rx->key || rx->key->conf.alg != ALG_CCMP)
1042                         return RX_DROP_UNUSABLE;
1043                 memcpy(pn, entry->last_pn, CCMP_PN_LEN);
1044                 for (i = CCMP_PN_LEN - 1; i >= 0; i--) {
1045                         pn[i]++;
1046                         if (pn[i])
1047                                 break;
1048                 }
1049                 rpn = rx->key->u.ccmp.rx_pn[rx->queue];
1050                 if (memcmp(pn, rpn, CCMP_PN_LEN))
1051                         return RX_DROP_UNUSABLE;
1052                 memcpy(entry->last_pn, pn, CCMP_PN_LEN);
1053         }
1054
1055         skb_pull(rx->skb, ieee80211_hdrlen(fc));
1056         __skb_queue_tail(&entry->skb_list, rx->skb);
1057         entry->last_frag = frag;
1058         entry->extra_len += rx->skb->len;
1059         if (ieee80211_has_morefrags(fc)) {
1060                 rx->skb = NULL;
1061                 return RX_QUEUED;
1062         }
1063
1064         rx->skb = __skb_dequeue(&entry->skb_list);
1065         if (skb_tailroom(rx->skb) < entry->extra_len) {
1066                 I802_DEBUG_INC(rx->local->rx_expand_skb_head2);
1067                 if (unlikely(pskb_expand_head(rx->skb, 0, entry->extra_len,
1068                                               GFP_ATOMIC))) {
1069                         I802_DEBUG_INC(rx->local->rx_handlers_drop_defrag);
1070                         __skb_queue_purge(&entry->skb_list);
1071                         return RX_DROP_UNUSABLE;
1072                 }
1073         }
1074         while ((skb = __skb_dequeue(&entry->skb_list))) {
1075                 memcpy(skb_put(rx->skb, skb->len), skb->data, skb->len);
1076                 dev_kfree_skb(skb);
1077         }
1078
1079         /* Complete frame has been reassembled - process it now */
1080         rx->flags |= IEEE80211_RX_FRAGMENTED;
1081
1082  out:
1083         if (rx->sta)
1084                 rx->sta->rx_packets++;
1085         if (is_multicast_ether_addr(hdr->addr1))
1086                 rx->local->dot11MulticastReceivedFrameCount++;
1087         else
1088                 ieee80211_led_rx(rx->local);
1089         return RX_CONTINUE;
1090 }
1091
1092 static ieee80211_rx_result debug_noinline
1093 ieee80211_rx_h_ps_poll(struct ieee80211_rx_data *rx)
1094 {
1095         struct ieee80211_sub_if_data *sdata = rx->sdata;
1096         __le16 fc = ((struct ieee80211_hdr *)rx->skb->data)->frame_control;
1097
1098         if (likely(!rx->sta || !ieee80211_is_pspoll(fc) ||
1099                    !(rx->flags & IEEE80211_RX_RA_MATCH)))
1100                 return RX_CONTINUE;
1101
1102         if ((sdata->vif.type != NL80211_IFTYPE_AP) &&
1103             (sdata->vif.type != NL80211_IFTYPE_AP_VLAN))
1104                 return RX_DROP_UNUSABLE;
1105
1106         if (!test_sta_flags(rx->sta, WLAN_STA_PS_DRIVER))
1107                 ieee80211_sta_ps_deliver_poll_response(rx->sta);
1108         else
1109                 set_sta_flags(rx->sta, WLAN_STA_PSPOLL);
1110
1111         /* Free PS Poll skb here instead of returning RX_DROP that would
1112          * count as an dropped frame. */
1113         dev_kfree_skb(rx->skb);
1114
1115         return RX_QUEUED;
1116 }
1117
1118 static ieee80211_rx_result debug_noinline
1119 ieee80211_rx_h_remove_qos_control(struct ieee80211_rx_data *rx)
1120 {
1121         u8 *data = rx->skb->data;
1122         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)data;
1123
1124         if (!ieee80211_is_data_qos(hdr->frame_control))
1125                 return RX_CONTINUE;
1126
1127         /* remove the qos control field, update frame type and meta-data */
1128         memmove(data + IEEE80211_QOS_CTL_LEN, data,
1129                 ieee80211_hdrlen(hdr->frame_control) - IEEE80211_QOS_CTL_LEN);
1130         hdr = (struct ieee80211_hdr *)skb_pull(rx->skb, IEEE80211_QOS_CTL_LEN);
1131         /* change frame type to non QOS */
1132         hdr->frame_control &= ~cpu_to_le16(IEEE80211_STYPE_QOS_DATA);
1133
1134         return RX_CONTINUE;
1135 }
1136
1137 static int
1138 ieee80211_802_1x_port_control(struct ieee80211_rx_data *rx)
1139 {
1140         if (unlikely(!rx->sta ||
1141             !test_sta_flags(rx->sta, WLAN_STA_AUTHORIZED)))
1142                 return -EACCES;
1143
1144         return 0;
1145 }
1146
1147 static int
1148 ieee80211_drop_unencrypted(struct ieee80211_rx_data *rx, __le16 fc)
1149 {
1150         struct sk_buff *skb = rx->skb;
1151         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
1152
1153         /*
1154          * Pass through unencrypted frames if the hardware has
1155          * decrypted them already.
1156          */
1157         if (status->flag & RX_FLAG_DECRYPTED)
1158                 return 0;
1159
1160         /* Drop unencrypted frames if key is set. */
1161         if (unlikely(!ieee80211_has_protected(fc) &&
1162                      !ieee80211_is_nullfunc(fc) &&
1163                      ieee80211_is_data(fc) &&
1164                      (rx->key || rx->sdata->drop_unencrypted)))
1165                 return -EACCES;
1166         if (rx->sta && test_sta_flags(rx->sta, WLAN_STA_MFP)) {
1167                 if (unlikely(ieee80211_is_unicast_robust_mgmt_frame(rx->skb) &&
1168                              rx->key))
1169                         return -EACCES;
1170                 /* BIP does not use Protected field, so need to check MMIE */
1171                 if (unlikely(ieee80211_is_multicast_robust_mgmt_frame(rx->skb) &&
1172                              ieee80211_get_mmie_keyidx(rx->skb) < 0 &&
1173                              rx->key))
1174                         return -EACCES;
1175                 /*
1176                  * When using MFP, Action frames are not allowed prior to
1177                  * having configured keys.
1178                  */
1179                 if (unlikely(ieee80211_is_action(fc) && !rx->key &&
1180                              ieee80211_is_robust_mgmt_frame(
1181                                      (struct ieee80211_hdr *) rx->skb->data)))
1182                         return -EACCES;
1183         }
1184
1185         return 0;
1186 }
1187
1188 static int
1189 __ieee80211_data_to_8023(struct ieee80211_rx_data *rx)
1190 {
1191         struct ieee80211_sub_if_data *sdata = rx->sdata;
1192         struct net_device *dev = sdata->dev;
1193         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
1194
1195         if (ieee80211_has_a4(hdr->frame_control) &&
1196             sdata->vif.type == NL80211_IFTYPE_AP_VLAN && !sdata->u.vlan.sta)
1197                 return -1;
1198
1199         if (is_multicast_ether_addr(hdr->addr1) &&
1200             ((sdata->vif.type == NL80211_IFTYPE_AP_VLAN && sdata->u.vlan.sta) ||
1201              (sdata->vif.type == NL80211_IFTYPE_STATION && sdata->u.mgd.use_4addr)))
1202                 return -1;
1203
1204         return ieee80211_data_to_8023(rx->skb, dev->dev_addr, sdata->vif.type);
1205 }
1206
1207 /*
1208  * requires that rx->skb is a frame with ethernet header
1209  */
1210 static bool ieee80211_frame_allowed(struct ieee80211_rx_data *rx, __le16 fc)
1211 {
1212         static const u8 pae_group_addr[ETH_ALEN] __aligned(2)
1213                 = { 0x01, 0x80, 0xC2, 0x00, 0x00, 0x03 };
1214         struct ethhdr *ehdr = (struct ethhdr *) rx->skb->data;
1215
1216         /*
1217          * Allow EAPOL frames to us/the PAE group address regardless
1218          * of whether the frame was encrypted or not.
1219          */
1220         if (ehdr->h_proto == htons(ETH_P_PAE) &&
1221             (compare_ether_addr(ehdr->h_dest, rx->sdata->dev->dev_addr) == 0 ||
1222              compare_ether_addr(ehdr->h_dest, pae_group_addr) == 0))
1223                 return true;
1224
1225         if (ieee80211_802_1x_port_control(rx) ||
1226             ieee80211_drop_unencrypted(rx, fc))
1227                 return false;
1228
1229         return true;
1230 }
1231
1232 /*
1233  * requires that rx->skb is a frame with ethernet header
1234  */
1235 static void
1236 ieee80211_deliver_skb(struct ieee80211_rx_data *rx)
1237 {
1238         struct ieee80211_sub_if_data *sdata = rx->sdata;
1239         struct net_device *dev = sdata->dev;
1240         struct ieee80211_local *local = rx->local;
1241         struct sk_buff *skb, *xmit_skb;
1242         struct ethhdr *ehdr = (struct ethhdr *) rx->skb->data;
1243         struct sta_info *dsta;
1244
1245         skb = rx->skb;
1246         xmit_skb = NULL;
1247
1248         if ((sdata->vif.type == NL80211_IFTYPE_AP ||
1249              sdata->vif.type == NL80211_IFTYPE_AP_VLAN) &&
1250             !(sdata->flags & IEEE80211_SDATA_DONT_BRIDGE_PACKETS) &&
1251             (rx->flags & IEEE80211_RX_RA_MATCH) &&
1252             (sdata->vif.type != NL80211_IFTYPE_AP_VLAN || !sdata->u.vlan.sta)) {
1253                 if (is_multicast_ether_addr(ehdr->h_dest)) {
1254                         /*
1255                          * send multicast frames both to higher layers in
1256                          * local net stack and back to the wireless medium
1257                          */
1258                         xmit_skb = skb_copy(skb, GFP_ATOMIC);
1259                         if (!xmit_skb && net_ratelimit())
1260                                 printk(KERN_DEBUG "%s: failed to clone "
1261                                        "multicast frame\n", dev->name);
1262                 } else {
1263                         dsta = sta_info_get(local, skb->data);
1264                         if (dsta && dsta->sdata->dev == dev) {
1265                                 /*
1266                                  * The destination station is associated to
1267                                  * this AP (in this VLAN), so send the frame
1268                                  * directly to it and do not pass it to local
1269                                  * net stack.
1270                                  */
1271                                 xmit_skb = skb;
1272                                 skb = NULL;
1273                         }
1274                 }
1275         }
1276
1277         if (skb) {
1278                 int align __maybe_unused;
1279
1280 #if defined(CONFIG_MAC80211_DEBUG_PACKET_ALIGNMENT) || !defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS)
1281                 /*
1282                  * 'align' will only take the values 0 or 2 here
1283                  * since all frames are required to be aligned
1284                  * to 2-byte boundaries when being passed to
1285                  * mac80211. That also explains the __skb_push()
1286                  * below.
1287                  */
1288                 align = ((unsigned long)(skb->data + sizeof(struct ethhdr))) & 3;
1289                 if (align) {
1290                         if (WARN_ON(skb_headroom(skb) < 3)) {
1291                                 dev_kfree_skb(skb);
1292                                 skb = NULL;
1293                         } else {
1294                                 u8 *data = skb->data;
1295                                 size_t len = skb_headlen(skb);
1296                                 skb->data -= align;
1297                                 memmove(skb->data, data, len);
1298                                 skb_set_tail_pointer(skb, len);
1299                         }
1300                 }
1301 #endif
1302
1303                 if (skb) {
1304                         /* deliver to local stack */
1305                         skb->protocol = eth_type_trans(skb, dev);
1306                         memset(skb->cb, 0, sizeof(skb->cb));
1307                         netif_rx(skb);
1308                 }
1309         }
1310
1311         if (xmit_skb) {
1312                 /* send to wireless media */
1313                 xmit_skb->protocol = htons(ETH_P_802_3);
1314                 skb_reset_network_header(xmit_skb);
1315                 skb_reset_mac_header(xmit_skb);
1316                 dev_queue_xmit(xmit_skb);
1317         }
1318 }
1319
1320 static ieee80211_rx_result debug_noinline
1321 ieee80211_rx_h_amsdu(struct ieee80211_rx_data *rx)
1322 {
1323         struct net_device *dev = rx->sdata->dev;
1324         struct ieee80211_local *local = rx->local;
1325         u16 ethertype;
1326         u8 *payload;
1327         struct sk_buff *skb = rx->skb, *frame = NULL;
1328         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
1329         __le16 fc = hdr->frame_control;
1330         const struct ethhdr *eth;
1331         int remaining, err;
1332         u8 dst[ETH_ALEN];
1333         u8 src[ETH_ALEN];
1334
1335         if (unlikely(!ieee80211_is_data(fc)))
1336                 return RX_CONTINUE;
1337
1338         if (unlikely(!ieee80211_is_data_present(fc)))
1339                 return RX_DROP_MONITOR;
1340
1341         if (!(rx->flags & IEEE80211_RX_AMSDU))
1342                 return RX_CONTINUE;
1343
1344         err = __ieee80211_data_to_8023(rx);
1345         if (unlikely(err))
1346                 return RX_DROP_UNUSABLE;
1347
1348         skb->dev = dev;
1349
1350         dev->stats.rx_packets++;
1351         dev->stats.rx_bytes += skb->len;
1352
1353         /* skip the wrapping header */
1354         eth = (struct ethhdr *) skb_pull(skb, sizeof(struct ethhdr));
1355         if (!eth)
1356                 return RX_DROP_UNUSABLE;
1357
1358         while (skb != frame) {
1359                 u8 padding;
1360                 __be16 len = eth->h_proto;
1361                 unsigned int subframe_len = sizeof(struct ethhdr) + ntohs(len);
1362
1363                 remaining = skb->len;
1364                 memcpy(dst, eth->h_dest, ETH_ALEN);
1365                 memcpy(src, eth->h_source, ETH_ALEN);
1366
1367                 padding = ((4 - subframe_len) & 0x3);
1368                 /* the last MSDU has no padding */
1369                 if (subframe_len > remaining)
1370                         return RX_DROP_UNUSABLE;
1371
1372                 skb_pull(skb, sizeof(struct ethhdr));
1373                 /* if last subframe reuse skb */
1374                 if (remaining <= subframe_len + padding)
1375                         frame = skb;
1376                 else {
1377                         /*
1378                          * Allocate and reserve two bytes more for payload
1379                          * alignment since sizeof(struct ethhdr) is 14.
1380                          */
1381                         frame = dev_alloc_skb(
1382                                 ALIGN(local->hw.extra_tx_headroom, 4) +
1383                                 subframe_len + 2);
1384
1385                         if (frame == NULL)
1386                                 return RX_DROP_UNUSABLE;
1387
1388                         skb_reserve(frame,
1389                                     ALIGN(local->hw.extra_tx_headroom, 4) +
1390                                     sizeof(struct ethhdr) + 2);
1391                         memcpy(skb_put(frame, ntohs(len)), skb->data,
1392                                 ntohs(len));
1393
1394                         eth = (struct ethhdr *) skb_pull(skb, ntohs(len) +
1395                                                         padding);
1396                         if (!eth) {
1397                                 dev_kfree_skb(frame);
1398                                 return RX_DROP_UNUSABLE;
1399                         }
1400                 }
1401
1402                 skb_reset_network_header(frame);
1403                 frame->dev = dev;
1404                 frame->priority = skb->priority;
1405                 rx->skb = frame;
1406
1407                 payload = frame->data;
1408                 ethertype = (payload[6] << 8) | payload[7];
1409
1410                 if (likely((compare_ether_addr(payload, rfc1042_header) == 0 &&
1411                             ethertype != ETH_P_AARP && ethertype != ETH_P_IPX) ||
1412                            compare_ether_addr(payload,
1413                                               bridge_tunnel_header) == 0)) {
1414                         /* remove RFC1042 or Bridge-Tunnel
1415                          * encapsulation and replace EtherType */
1416                         skb_pull(frame, 6);
1417                         memcpy(skb_push(frame, ETH_ALEN), src, ETH_ALEN);
1418                         memcpy(skb_push(frame, ETH_ALEN), dst, ETH_ALEN);
1419                 } else {
1420                         memcpy(skb_push(frame, sizeof(__be16)),
1421                                &len, sizeof(__be16));
1422                         memcpy(skb_push(frame, ETH_ALEN), src, ETH_ALEN);
1423                         memcpy(skb_push(frame, ETH_ALEN), dst, ETH_ALEN);
1424                 }
1425
1426                 if (!ieee80211_frame_allowed(rx, fc)) {
1427                         if (skb == frame) /* last frame */
1428                                 return RX_DROP_UNUSABLE;
1429                         dev_kfree_skb(frame);
1430                         continue;
1431                 }
1432
1433                 ieee80211_deliver_skb(rx);
1434         }
1435
1436         return RX_QUEUED;
1437 }
1438
1439 #ifdef CONFIG_MAC80211_MESH
1440 static ieee80211_rx_result
1441 ieee80211_rx_h_mesh_fwding(struct ieee80211_rx_data *rx)
1442 {
1443         struct ieee80211_hdr *hdr;
1444         struct ieee80211s_hdr *mesh_hdr;
1445         unsigned int hdrlen;
1446         struct sk_buff *skb = rx->skb, *fwd_skb;
1447         struct ieee80211_local *local = rx->local;
1448         struct ieee80211_sub_if_data *sdata = rx->sdata;
1449
1450         hdr = (struct ieee80211_hdr *) skb->data;
1451         hdrlen = ieee80211_hdrlen(hdr->frame_control);
1452         mesh_hdr = (struct ieee80211s_hdr *) (skb->data + hdrlen);
1453
1454         if (!ieee80211_is_data(hdr->frame_control))
1455                 return RX_CONTINUE;
1456
1457         if (!mesh_hdr->ttl)
1458                 /* illegal frame */
1459                 return RX_DROP_MONITOR;
1460
1461         if (mesh_hdr->flags & MESH_FLAGS_AE) {
1462                 struct mesh_path *mppath;
1463                 char *proxied_addr;
1464                 char *mpp_addr;
1465
1466                 if (is_multicast_ether_addr(hdr->addr1)) {
1467                         mpp_addr = hdr->addr3;
1468                         proxied_addr = mesh_hdr->eaddr1;
1469                 } else {
1470                         mpp_addr = hdr->addr4;
1471                         proxied_addr = mesh_hdr->eaddr2;
1472                 }
1473
1474                 rcu_read_lock();
1475                 mppath = mpp_path_lookup(proxied_addr, sdata);
1476                 if (!mppath) {
1477                         mpp_path_add(proxied_addr, mpp_addr, sdata);
1478                 } else {
1479                         spin_lock_bh(&mppath->state_lock);
1480                         mppath->exp_time = jiffies;
1481                         if (compare_ether_addr(mppath->mpp, mpp_addr) != 0)
1482                                 memcpy(mppath->mpp, mpp_addr, ETH_ALEN);
1483                         spin_unlock_bh(&mppath->state_lock);
1484                 }
1485                 rcu_read_unlock();
1486         }
1487
1488         /* Frame has reached destination.  Don't forward */
1489         if (!is_multicast_ether_addr(hdr->addr1) &&
1490             compare_ether_addr(sdata->dev->dev_addr, hdr->addr3) == 0)
1491                 return RX_CONTINUE;
1492
1493         mesh_hdr->ttl--;
1494
1495         if (rx->flags & IEEE80211_RX_RA_MATCH) {
1496                 if (!mesh_hdr->ttl)
1497                         IEEE80211_IFSTA_MESH_CTR_INC(&rx->sdata->u.mesh,
1498                                                      dropped_frames_ttl);
1499                 else {
1500                         struct ieee80211_hdr *fwd_hdr;
1501                         struct ieee80211_tx_info *info;
1502
1503                         fwd_skb = skb_copy(skb, GFP_ATOMIC);
1504
1505                         if (!fwd_skb && net_ratelimit())
1506                                 printk(KERN_DEBUG "%s: failed to clone mesh frame\n",
1507                                                    sdata->dev->name);
1508
1509                         fwd_hdr =  (struct ieee80211_hdr *) fwd_skb->data;
1510                         memcpy(fwd_hdr->addr2, sdata->dev->dev_addr, ETH_ALEN);
1511                         info = IEEE80211_SKB_CB(fwd_skb);
1512                         memset(info, 0, sizeof(*info));
1513                         info->flags |= IEEE80211_TX_INTFL_NEED_TXPROCESSING;
1514                         info->control.vif = &rx->sdata->vif;
1515                         ieee80211_select_queue(local, fwd_skb);
1516                         if (is_multicast_ether_addr(fwd_hdr->addr1))
1517                                 IEEE80211_IFSTA_MESH_CTR_INC(&sdata->u.mesh,
1518                                                                 fwded_mcast);
1519                         else {
1520                                 int err;
1521                                 /*
1522                                  * Save TA to addr1 to send TA a path error if a
1523                                  * suitable next hop is not found
1524                                  */
1525                                 memcpy(fwd_hdr->addr1, fwd_hdr->addr2,
1526                                                 ETH_ALEN);
1527                                 err = mesh_nexthop_lookup(fwd_skb, sdata);
1528                                 /* Failed to immediately resolve next hop:
1529                                  * fwded frame was dropped or will be added
1530                                  * later to the pending skb queue.  */
1531                                 if (err)
1532                                         return RX_DROP_MONITOR;
1533
1534                                 IEEE80211_IFSTA_MESH_CTR_INC(&sdata->u.mesh,
1535                                                                 fwded_unicast);
1536                         }
1537                         IEEE80211_IFSTA_MESH_CTR_INC(&sdata->u.mesh,
1538                                                      fwded_frames);
1539                         ieee80211_add_pending_skb(local, fwd_skb);
1540                 }
1541         }
1542
1543         if (is_multicast_ether_addr(hdr->addr1) ||
1544             sdata->dev->flags & IFF_PROMISC)
1545                 return RX_CONTINUE;
1546         else
1547                 return RX_DROP_MONITOR;
1548 }
1549 #endif
1550
1551 static ieee80211_rx_result debug_noinline
1552 ieee80211_rx_h_data(struct ieee80211_rx_data *rx)
1553 {
1554         struct ieee80211_sub_if_data *sdata = rx->sdata;
1555         struct net_device *dev = sdata->dev;
1556         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
1557         __le16 fc = hdr->frame_control;
1558         int err;
1559
1560         if (unlikely(!ieee80211_is_data(hdr->frame_control)))
1561                 return RX_CONTINUE;
1562
1563         if (unlikely(!ieee80211_is_data_present(hdr->frame_control)))
1564                 return RX_DROP_MONITOR;
1565
1566         /*
1567          * Allow the cooked monitor interface of an AP to see 4-addr frames so
1568          * that a 4-addr station can be detected and moved into a separate VLAN
1569          */
1570         if (ieee80211_has_a4(hdr->frame_control) &&
1571             sdata->vif.type == NL80211_IFTYPE_AP)
1572                 return RX_DROP_MONITOR;
1573
1574         err = __ieee80211_data_to_8023(rx);
1575         if (unlikely(err))
1576                 return RX_DROP_UNUSABLE;
1577
1578         if (!ieee80211_frame_allowed(rx, fc))
1579                 return RX_DROP_MONITOR;
1580
1581         rx->skb->dev = dev;
1582
1583         dev->stats.rx_packets++;
1584         dev->stats.rx_bytes += rx->skb->len;
1585
1586         ieee80211_deliver_skb(rx);
1587
1588         return RX_QUEUED;
1589 }
1590
1591 static ieee80211_rx_result debug_noinline
1592 ieee80211_rx_h_ctrl(struct ieee80211_rx_data *rx)
1593 {
1594         struct ieee80211_local *local = rx->local;
1595         struct ieee80211_hw *hw = &local->hw;
1596         struct sk_buff *skb = rx->skb;
1597         struct ieee80211_bar *bar = (struct ieee80211_bar *)skb->data;
1598         struct tid_ampdu_rx *tid_agg_rx;
1599         u16 start_seq_num;
1600         u16 tid;
1601
1602         if (likely(!ieee80211_is_ctl(bar->frame_control)))
1603                 return RX_CONTINUE;
1604
1605         if (ieee80211_is_back_req(bar->frame_control)) {
1606                 if (!rx->sta)
1607                         return RX_DROP_MONITOR;
1608                 tid = le16_to_cpu(bar->control) >> 12;
1609                 if (rx->sta->ampdu_mlme.tid_state_rx[tid]
1610                                         != HT_AGG_STATE_OPERATIONAL)
1611                         return RX_DROP_MONITOR;
1612                 tid_agg_rx = rx->sta->ampdu_mlme.tid_rx[tid];
1613
1614                 start_seq_num = le16_to_cpu(bar->start_seq_num) >> 4;
1615
1616                 /* reset session timer */
1617                 if (tid_agg_rx->timeout)
1618                         mod_timer(&tid_agg_rx->session_timer,
1619                                   TU_TO_EXP_TIME(tid_agg_rx->timeout));
1620
1621                 /* release stored frames up to start of BAR */
1622                 ieee80211_release_reorder_frames(hw, tid_agg_rx, start_seq_num);
1623                 kfree_skb(skb);
1624                 return RX_QUEUED;
1625         }
1626
1627         return RX_CONTINUE;
1628 }
1629
1630 static void ieee80211_process_sa_query_req(struct ieee80211_sub_if_data *sdata,
1631                                            struct ieee80211_mgmt *mgmt,
1632                                            size_t len)
1633 {
1634         struct ieee80211_local *local = sdata->local;
1635         struct sk_buff *skb;
1636         struct ieee80211_mgmt *resp;
1637
1638         if (compare_ether_addr(mgmt->da, sdata->dev->dev_addr) != 0) {
1639                 /* Not to own unicast address */
1640                 return;
1641         }
1642
1643         if (compare_ether_addr(mgmt->sa, sdata->u.mgd.bssid) != 0 ||
1644             compare_ether_addr(mgmt->bssid, sdata->u.mgd.bssid) != 0) {
1645                 /* Not from the current AP or not associated yet. */
1646                 return;
1647         }
1648
1649         if (len < 24 + 1 + sizeof(resp->u.action.u.sa_query)) {
1650                 /* Too short SA Query request frame */
1651                 return;
1652         }
1653
1654         skb = dev_alloc_skb(sizeof(*resp) + local->hw.extra_tx_headroom);
1655         if (skb == NULL)
1656                 return;
1657
1658         skb_reserve(skb, local->hw.extra_tx_headroom);
1659         resp = (struct ieee80211_mgmt *) skb_put(skb, 24);
1660         memset(resp, 0, 24);
1661         memcpy(resp->da, mgmt->sa, ETH_ALEN);
1662         memcpy(resp->sa, sdata->dev->dev_addr, ETH_ALEN);
1663         memcpy(resp->bssid, sdata->u.mgd.bssid, ETH_ALEN);
1664         resp->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
1665                                           IEEE80211_STYPE_ACTION);
1666         skb_put(skb, 1 + sizeof(resp->u.action.u.sa_query));
1667         resp->u.action.category = WLAN_CATEGORY_SA_QUERY;
1668         resp->u.action.u.sa_query.action = WLAN_ACTION_SA_QUERY_RESPONSE;
1669         memcpy(resp->u.action.u.sa_query.trans_id,
1670                mgmt->u.action.u.sa_query.trans_id,
1671                WLAN_SA_QUERY_TR_ID_LEN);
1672
1673         ieee80211_tx_skb(sdata, skb);
1674 }
1675
1676 static ieee80211_rx_result debug_noinline
1677 ieee80211_rx_h_action(struct ieee80211_rx_data *rx)
1678 {
1679         struct ieee80211_local *local = rx->local;
1680         struct ieee80211_sub_if_data *sdata = rx->sdata;
1681         struct ieee80211_mgmt *mgmt = (struct ieee80211_mgmt *) rx->skb->data;
1682         int len = rx->skb->len;
1683
1684         if (!ieee80211_is_action(mgmt->frame_control))
1685                 return RX_CONTINUE;
1686
1687         if (!rx->sta)
1688                 return RX_DROP_MONITOR;
1689
1690         if (!(rx->flags & IEEE80211_RX_RA_MATCH))
1691                 return RX_DROP_MONITOR;
1692
1693         if (ieee80211_drop_unencrypted(rx, mgmt->frame_control))
1694                 return RX_DROP_MONITOR;
1695
1696         /* all categories we currently handle have action_code */
1697         if (len < IEEE80211_MIN_ACTION_SIZE + 1)
1698                 return RX_DROP_MONITOR;
1699
1700         switch (mgmt->u.action.category) {
1701         case WLAN_CATEGORY_BACK:
1702                 /*
1703                  * The aggregation code is not prepared to handle
1704                  * anything but STA/AP due to the BSSID handling;
1705                  * IBSS could work in the code but isn't supported
1706                  * by drivers or the standard.
1707                  */
1708                 if (sdata->vif.type != NL80211_IFTYPE_STATION &&
1709                     sdata->vif.type != NL80211_IFTYPE_AP_VLAN &&
1710                     sdata->vif.type != NL80211_IFTYPE_AP)
1711                         return RX_DROP_MONITOR;
1712
1713                 switch (mgmt->u.action.u.addba_req.action_code) {
1714                 case WLAN_ACTION_ADDBA_REQ:
1715                         if (len < (IEEE80211_MIN_ACTION_SIZE +
1716                                    sizeof(mgmt->u.action.u.addba_req)))
1717                                 return RX_DROP_MONITOR;
1718                         ieee80211_process_addba_request(local, rx->sta, mgmt, len);
1719                         break;
1720                 case WLAN_ACTION_ADDBA_RESP:
1721                         if (len < (IEEE80211_MIN_ACTION_SIZE +
1722                                    sizeof(mgmt->u.action.u.addba_resp)))
1723                                 return RX_DROP_MONITOR;
1724                         ieee80211_process_addba_resp(local, rx->sta, mgmt, len);
1725                         break;
1726                 case WLAN_ACTION_DELBA:
1727                         if (len < (IEEE80211_MIN_ACTION_SIZE +
1728                                    sizeof(mgmt->u.action.u.delba)))
1729                                 return RX_DROP_MONITOR;
1730                         ieee80211_process_delba(sdata, rx->sta, mgmt, len);
1731                         break;
1732                 }
1733                 break;
1734         case WLAN_CATEGORY_SPECTRUM_MGMT:
1735                 if (local->hw.conf.channel->band != IEEE80211_BAND_5GHZ)
1736                         return RX_DROP_MONITOR;
1737
1738                 if (sdata->vif.type != NL80211_IFTYPE_STATION)
1739                         return RX_DROP_MONITOR;
1740
1741                 switch (mgmt->u.action.u.measurement.action_code) {
1742                 case WLAN_ACTION_SPCT_MSR_REQ:
1743                         if (len < (IEEE80211_MIN_ACTION_SIZE +
1744                                    sizeof(mgmt->u.action.u.measurement)))
1745                                 return RX_DROP_MONITOR;
1746                         ieee80211_process_measurement_req(sdata, mgmt, len);
1747                         break;
1748                 case WLAN_ACTION_SPCT_CHL_SWITCH:
1749                         if (len < (IEEE80211_MIN_ACTION_SIZE +
1750                                    sizeof(mgmt->u.action.u.chan_switch)))
1751                                 return RX_DROP_MONITOR;
1752
1753                         if (sdata->vif.type != NL80211_IFTYPE_STATION)
1754                                 return RX_DROP_MONITOR;
1755
1756                         if (memcmp(mgmt->bssid, sdata->u.mgd.bssid, ETH_ALEN))
1757                                 return RX_DROP_MONITOR;
1758
1759                         return ieee80211_sta_rx_mgmt(sdata, rx->skb);
1760                 }
1761                 break;
1762         case WLAN_CATEGORY_SA_QUERY:
1763                 if (len < (IEEE80211_MIN_ACTION_SIZE +
1764                            sizeof(mgmt->u.action.u.sa_query)))
1765                         return RX_DROP_MONITOR;
1766                 switch (mgmt->u.action.u.sa_query.action) {
1767                 case WLAN_ACTION_SA_QUERY_REQUEST:
1768                         if (sdata->vif.type != NL80211_IFTYPE_STATION)
1769                                 return RX_DROP_MONITOR;
1770                         ieee80211_process_sa_query_req(sdata, mgmt, len);
1771                         break;
1772                 case WLAN_ACTION_SA_QUERY_RESPONSE:
1773                         /*
1774                          * SA Query response is currently only used in AP mode
1775                          * and it is processed in user space.
1776                          */
1777                         return RX_CONTINUE;
1778                 }
1779                 break;
1780         default:
1781                 return RX_CONTINUE;
1782         }
1783
1784         rx->sta->rx_packets++;
1785         dev_kfree_skb(rx->skb);
1786         return RX_QUEUED;
1787 }
1788
1789 static ieee80211_rx_result debug_noinline
1790 ieee80211_rx_h_mgmt(struct ieee80211_rx_data *rx)
1791 {
1792         struct ieee80211_sub_if_data *sdata = rx->sdata;
1793         struct ieee80211_mgmt *mgmt = (struct ieee80211_mgmt *) rx->skb->data;
1794
1795         if (!(rx->flags & IEEE80211_RX_RA_MATCH))
1796                 return RX_DROP_MONITOR;
1797
1798         if (ieee80211_drop_unencrypted(rx, mgmt->frame_control))
1799                 return RX_DROP_MONITOR;
1800
1801         if (ieee80211_vif_is_mesh(&sdata->vif))
1802                 return ieee80211_mesh_rx_mgmt(sdata, rx->skb);
1803
1804         if (sdata->vif.type == NL80211_IFTYPE_ADHOC)
1805                 return ieee80211_ibss_rx_mgmt(sdata, rx->skb);
1806
1807         if (sdata->vif.type == NL80211_IFTYPE_STATION)
1808                 return ieee80211_sta_rx_mgmt(sdata, rx->skb);
1809
1810         return RX_DROP_MONITOR;
1811 }
1812
1813 static void ieee80211_rx_michael_mic_report(struct ieee80211_hdr *hdr,
1814                                             struct ieee80211_rx_data *rx)
1815 {
1816         int keyidx;
1817         unsigned int hdrlen;
1818
1819         hdrlen = ieee80211_hdrlen(hdr->frame_control);
1820         if (rx->skb->len >= hdrlen + 4)
1821                 keyidx = rx->skb->data[hdrlen + 3] >> 6;
1822         else
1823                 keyidx = -1;
1824
1825         if (!rx->sta) {
1826                 /*
1827                  * Some hardware seem to generate incorrect Michael MIC
1828                  * reports; ignore them to avoid triggering countermeasures.
1829                  */
1830                 return;
1831         }
1832
1833         if (!ieee80211_has_protected(hdr->frame_control))
1834                 return;
1835
1836         if (rx->sdata->vif.type == NL80211_IFTYPE_AP && keyidx) {
1837                 /*
1838                  * APs with pairwise keys should never receive Michael MIC
1839                  * errors for non-zero keyidx because these are reserved for
1840                  * group keys and only the AP is sending real multicast
1841                  * frames in the BSS.
1842                  */
1843                 return;
1844         }
1845
1846         if (!ieee80211_is_data(hdr->frame_control) &&
1847             !ieee80211_is_auth(hdr->frame_control))
1848                 return;
1849
1850         mac80211_ev_michael_mic_failure(rx->sdata, keyidx, hdr, NULL,
1851                                         GFP_ATOMIC);
1852 }
1853
1854 /* TODO: use IEEE80211_RX_FRAGMENTED */
1855 static void ieee80211_rx_cooked_monitor(struct ieee80211_rx_data *rx,
1856                                         struct ieee80211_rate *rate)
1857 {
1858         struct ieee80211_sub_if_data *sdata;
1859         struct ieee80211_local *local = rx->local;
1860         struct ieee80211_rtap_hdr {
1861                 struct ieee80211_radiotap_header hdr;
1862                 u8 flags;
1863                 u8 rate_or_pad;
1864                 __le16 chan_freq;
1865                 __le16 chan_flags;
1866         } __attribute__ ((packed)) *rthdr;
1867         struct sk_buff *skb = rx->skb, *skb2;
1868         struct net_device *prev_dev = NULL;
1869         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
1870
1871         if (rx->flags & IEEE80211_RX_CMNTR_REPORTED)
1872                 goto out_free_skb;
1873
1874         if (skb_headroom(skb) < sizeof(*rthdr) &&
1875             pskb_expand_head(skb, sizeof(*rthdr), 0, GFP_ATOMIC))
1876                 goto out_free_skb;
1877
1878         rthdr = (void *)skb_push(skb, sizeof(*rthdr));
1879         memset(rthdr, 0, sizeof(*rthdr));
1880         rthdr->hdr.it_len = cpu_to_le16(sizeof(*rthdr));
1881         rthdr->hdr.it_present =
1882                 cpu_to_le32((1 << IEEE80211_RADIOTAP_FLAGS) |
1883                             (1 << IEEE80211_RADIOTAP_CHANNEL));
1884
1885         if (rate) {
1886                 rthdr->rate_or_pad = rate->bitrate / 5;
1887                 rthdr->hdr.it_present |=
1888                         cpu_to_le32(1 << IEEE80211_RADIOTAP_RATE);
1889         }
1890         rthdr->chan_freq = cpu_to_le16(status->freq);
1891
1892         if (status->band == IEEE80211_BAND_5GHZ)
1893                 rthdr->chan_flags = cpu_to_le16(IEEE80211_CHAN_OFDM |
1894                                                 IEEE80211_CHAN_5GHZ);
1895         else
1896                 rthdr->chan_flags = cpu_to_le16(IEEE80211_CHAN_DYN |
1897                                                 IEEE80211_CHAN_2GHZ);
1898
1899         skb_set_mac_header(skb, 0);
1900         skb->ip_summed = CHECKSUM_UNNECESSARY;
1901         skb->pkt_type = PACKET_OTHERHOST;
1902         skb->protocol = htons(ETH_P_802_2);
1903
1904         list_for_each_entry_rcu(sdata, &local->interfaces, list) {
1905                 if (!netif_running(sdata->dev))
1906                         continue;
1907
1908                 if (sdata->vif.type != NL80211_IFTYPE_MONITOR ||
1909                     !(sdata->u.mntr_flags & MONITOR_FLAG_COOK_FRAMES))
1910                         continue;
1911
1912                 if (prev_dev) {
1913                         skb2 = skb_clone(skb, GFP_ATOMIC);
1914                         if (skb2) {
1915                                 skb2->dev = prev_dev;
1916                                 netif_rx(skb2);
1917                         }
1918                 }
1919
1920                 prev_dev = sdata->dev;
1921                 sdata->dev->stats.rx_packets++;
1922                 sdata->dev->stats.rx_bytes += skb->len;
1923         }
1924
1925         if (prev_dev) {
1926                 skb->dev = prev_dev;
1927                 netif_rx(skb);
1928                 skb = NULL;
1929         } else
1930                 goto out_free_skb;
1931
1932         rx->flags |= IEEE80211_RX_CMNTR_REPORTED;
1933         return;
1934
1935  out_free_skb:
1936         dev_kfree_skb(skb);
1937 }
1938
1939
1940 static void ieee80211_invoke_rx_handlers(struct ieee80211_sub_if_data *sdata,
1941                                          struct ieee80211_rx_data *rx,
1942                                          struct sk_buff *skb,
1943                                          struct ieee80211_rate *rate)
1944 {
1945         ieee80211_rx_result res = RX_DROP_MONITOR;
1946
1947         rx->skb = skb;
1948         rx->sdata = sdata;
1949
1950 #define CALL_RXH(rxh)                   \
1951         do {                            \
1952                 res = rxh(rx);          \
1953                 if (res != RX_CONTINUE) \
1954                         goto rxh_done;  \
1955         } while (0);
1956
1957         CALL_RXH(ieee80211_rx_h_passive_scan)
1958         CALL_RXH(ieee80211_rx_h_check)
1959         CALL_RXH(ieee80211_rx_h_decrypt)
1960         CALL_RXH(ieee80211_rx_h_check_more_data)
1961         CALL_RXH(ieee80211_rx_h_sta_process)
1962         CALL_RXH(ieee80211_rx_h_defragment)
1963         CALL_RXH(ieee80211_rx_h_ps_poll)
1964         CALL_RXH(ieee80211_rx_h_michael_mic_verify)
1965         /* must be after MMIC verify so header is counted in MPDU mic */
1966         CALL_RXH(ieee80211_rx_h_remove_qos_control)
1967         CALL_RXH(ieee80211_rx_h_amsdu)
1968 #ifdef CONFIG_MAC80211_MESH
1969         if (ieee80211_vif_is_mesh(&sdata->vif))
1970                 CALL_RXH(ieee80211_rx_h_mesh_fwding);
1971 #endif
1972         CALL_RXH(ieee80211_rx_h_data)
1973         CALL_RXH(ieee80211_rx_h_ctrl)
1974         CALL_RXH(ieee80211_rx_h_action)
1975         CALL_RXH(ieee80211_rx_h_mgmt)
1976
1977 #undef CALL_RXH
1978
1979  rxh_done:
1980         switch (res) {
1981         case RX_DROP_MONITOR:
1982                 I802_DEBUG_INC(sdata->local->rx_handlers_drop);
1983                 if (rx->sta)
1984                         rx->sta->rx_dropped++;
1985                 /* fall through */
1986         case RX_CONTINUE:
1987                 ieee80211_rx_cooked_monitor(rx, rate);
1988                 break;
1989         case RX_DROP_UNUSABLE:
1990                 I802_DEBUG_INC(sdata->local->rx_handlers_drop);
1991                 if (rx->sta)
1992                         rx->sta->rx_dropped++;
1993                 dev_kfree_skb(rx->skb);
1994                 break;
1995         case RX_QUEUED:
1996                 I802_DEBUG_INC(sdata->local->rx_handlers_queued);
1997                 break;
1998         }
1999 }
2000
2001 /* main receive path */
2002
2003 static int prepare_for_handlers(struct ieee80211_sub_if_data *sdata,
2004                                 struct ieee80211_rx_data *rx,
2005                                 struct ieee80211_hdr *hdr)
2006 {
2007         struct sk_buff *skb = rx->skb;
2008         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
2009         u8 *bssid = ieee80211_get_bssid(hdr, skb->len, sdata->vif.type);
2010         int multicast = is_multicast_ether_addr(hdr->addr1);
2011
2012         switch (sdata->vif.type) {
2013         case NL80211_IFTYPE_STATION:
2014                 if (!bssid && !sdata->u.mgd.use_4addr)
2015                         return 0;
2016                 if (!multicast &&
2017                     compare_ether_addr(sdata->dev->dev_addr, hdr->addr1) != 0) {
2018                         if (!(sdata->dev->flags & IFF_PROMISC))
2019                                 return 0;
2020                         rx->flags &= ~IEEE80211_RX_RA_MATCH;
2021                 }
2022                 break;
2023         case NL80211_IFTYPE_ADHOC:
2024                 if (!bssid)
2025                         return 0;
2026                 if (ieee80211_is_beacon(hdr->frame_control)) {
2027                         return 1;
2028                 }
2029                 else if (!ieee80211_bssid_match(bssid, sdata->u.ibss.bssid)) {
2030                         if (!(rx->flags & IEEE80211_RX_IN_SCAN))
2031                                 return 0;
2032                         rx->flags &= ~IEEE80211_RX_RA_MATCH;
2033                 } else if (!multicast &&
2034                            compare_ether_addr(sdata->dev->dev_addr,
2035                                               hdr->addr1) != 0) {
2036                         if (!(sdata->dev->flags & IFF_PROMISC))
2037                                 return 0;
2038                         rx->flags &= ~IEEE80211_RX_RA_MATCH;
2039                 } else if (!rx->sta) {
2040                         int rate_idx;
2041                         if (status->flag & RX_FLAG_HT)
2042                                 rate_idx = 0; /* TODO: HT rates */
2043                         else
2044                                 rate_idx = status->rate_idx;
2045                         rx->sta = ieee80211_ibss_add_sta(sdata, bssid, hdr->addr2,
2046                                 BIT(rate_idx));
2047                 }
2048                 break;
2049         case NL80211_IFTYPE_MESH_POINT:
2050                 if (!multicast &&
2051                     compare_ether_addr(sdata->dev->dev_addr,
2052                                        hdr->addr1) != 0) {
2053                         if (!(sdata->dev->flags & IFF_PROMISC))
2054                                 return 0;
2055
2056                         rx->flags &= ~IEEE80211_RX_RA_MATCH;
2057                 }
2058                 break;
2059         case NL80211_IFTYPE_AP_VLAN:
2060         case NL80211_IFTYPE_AP:
2061                 if (!bssid) {
2062                         if (compare_ether_addr(sdata->dev->dev_addr,
2063                                                hdr->addr1))
2064                                 return 0;
2065                 } else if (!ieee80211_bssid_match(bssid,
2066                                         sdata->dev->dev_addr)) {
2067                         if (!(rx->flags & IEEE80211_RX_IN_SCAN))
2068                                 return 0;
2069                         rx->flags &= ~IEEE80211_RX_RA_MATCH;
2070                 }
2071                 break;
2072         case NL80211_IFTYPE_WDS:
2073                 if (bssid || !ieee80211_is_data(hdr->frame_control))
2074                         return 0;
2075                 if (compare_ether_addr(sdata->u.wds.remote_addr, hdr->addr2))
2076                         return 0;
2077                 break;
2078         case NL80211_IFTYPE_MONITOR:
2079         case NL80211_IFTYPE_UNSPECIFIED:
2080         case __NL80211_IFTYPE_AFTER_LAST:
2081                 /* should never get here */
2082                 WARN_ON(1);
2083                 break;
2084         }
2085
2086         return 1;
2087 }
2088
2089 /*
2090  * This is the actual Rx frames handler. as it blongs to Rx path it must
2091  * be called with rcu_read_lock protection.
2092  */
2093 static void __ieee80211_rx_handle_packet(struct ieee80211_hw *hw,
2094                                          struct sk_buff *skb,
2095                                          struct ieee80211_rate *rate)
2096 {
2097         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
2098         struct ieee80211_local *local = hw_to_local(hw);
2099         struct ieee80211_sub_if_data *sdata;
2100         struct ieee80211_hdr *hdr;
2101         struct ieee80211_rx_data rx;
2102         int prepares;
2103         struct ieee80211_sub_if_data *prev = NULL;
2104         struct sk_buff *skb_new;
2105
2106         hdr = (struct ieee80211_hdr *)skb->data;
2107         memset(&rx, 0, sizeof(rx));
2108         rx.skb = skb;
2109         rx.local = local;
2110
2111         if (ieee80211_is_data(hdr->frame_control) || ieee80211_is_mgmt(hdr->frame_control))
2112                 local->dot11ReceivedFragmentCount++;
2113
2114         if (unlikely(test_bit(SCAN_HW_SCANNING, &local->scanning) ||
2115                      test_bit(SCAN_OFF_CHANNEL, &local->scanning)))
2116                 rx.flags |= IEEE80211_RX_IN_SCAN;
2117
2118         ieee80211_parse_qos(&rx);
2119         ieee80211_verify_alignment(&rx);
2120
2121         rx.sta = sta_info_get(local, hdr->addr2);
2122         if (rx.sta)
2123                 rx.sdata = rx.sta->sdata;
2124
2125         if (rx.sdata && ieee80211_is_data(hdr->frame_control)) {
2126                 rx.flags |= IEEE80211_RX_RA_MATCH;
2127                 prepares = prepare_for_handlers(rx.sdata, &rx, hdr);
2128                 if (prepares) {
2129                         if (status->flag & RX_FLAG_MMIC_ERROR) {
2130                                 if (rx.flags & IEEE80211_RX_RA_MATCH)
2131                                         ieee80211_rx_michael_mic_report(hdr, &rx);
2132                         } else
2133                                 prev = rx.sdata;
2134                 }
2135         } else list_for_each_entry_rcu(sdata, &local->interfaces, list) {
2136                 if (!netif_running(sdata->dev))
2137                         continue;
2138
2139                 if (sdata->vif.type == NL80211_IFTYPE_MONITOR ||
2140                     sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
2141                         continue;
2142
2143                 rx.flags |= IEEE80211_RX_RA_MATCH;
2144                 prepares = prepare_for_handlers(sdata, &rx, hdr);
2145
2146                 if (!prepares)
2147                         continue;
2148
2149                 if (status->flag & RX_FLAG_MMIC_ERROR) {
2150                         rx.sdata = sdata;
2151                         if (rx.flags & IEEE80211_RX_RA_MATCH)
2152                                 ieee80211_rx_michael_mic_report(hdr, &rx);
2153                         continue;
2154                 }
2155
2156                 /*
2157                  * frame is destined for this interface, but if it's not
2158                  * also for the previous one we handle that after the
2159                  * loop to avoid copying the SKB once too much
2160                  */
2161
2162                 if (!prev) {
2163                         prev = sdata;
2164                         continue;
2165                 }
2166
2167                 /*
2168                  * frame was destined for the previous interface
2169                  * so invoke RX handlers for it
2170                  */
2171
2172                 skb_new = skb_copy(skb, GFP_ATOMIC);
2173                 if (!skb_new) {
2174                         if (net_ratelimit())
2175                                 printk(KERN_DEBUG "%s: failed to copy "
2176                                        "multicast frame for %s\n",
2177                                        wiphy_name(local->hw.wiphy),
2178                                        prev->dev->name);
2179                         continue;
2180                 }
2181                 ieee80211_invoke_rx_handlers(prev, &rx, skb_new, rate);
2182                 prev = sdata;
2183         }
2184         if (prev)
2185                 ieee80211_invoke_rx_handlers(prev, &rx, skb, rate);
2186         else
2187                 dev_kfree_skb(skb);
2188 }
2189
2190 #define SEQ_MODULO 0x1000
2191 #define SEQ_MASK   0xfff
2192
2193 static inline int seq_less(u16 sq1, u16 sq2)
2194 {
2195         return ((sq1 - sq2) & SEQ_MASK) > (SEQ_MODULO >> 1);
2196 }
2197
2198 static inline u16 seq_inc(u16 sq)
2199 {
2200         return (sq + 1) & SEQ_MASK;
2201 }
2202
2203 static inline u16 seq_sub(u16 sq1, u16 sq2)
2204 {
2205         return (sq1 - sq2) & SEQ_MASK;
2206 }
2207
2208
2209 static void ieee80211_release_reorder_frame(struct ieee80211_hw *hw,
2210                                             struct tid_ampdu_rx *tid_agg_rx,
2211                                             int index)
2212 {
2213         struct ieee80211_supported_band *sband;
2214         struct ieee80211_rate *rate = NULL;
2215         struct sk_buff *skb = tid_agg_rx->reorder_buf[index];
2216         struct ieee80211_rx_status *status;
2217
2218         if (!skb)
2219                 goto no_frame;
2220
2221         status = IEEE80211_SKB_RXCB(skb);
2222
2223         /* release the reordered frames to stack */
2224         sband = hw->wiphy->bands[status->band];
2225         if (!(status->flag & RX_FLAG_HT))
2226                 rate = &sband->bitrates[status->rate_idx];
2227         __ieee80211_rx_handle_packet(hw, skb, rate);
2228         tid_agg_rx->stored_mpdu_num--;
2229         tid_agg_rx->reorder_buf[index] = NULL;
2230
2231 no_frame:
2232         tid_agg_rx->head_seq_num = seq_inc(tid_agg_rx->head_seq_num);
2233 }
2234
2235 static void ieee80211_release_reorder_frames(struct ieee80211_hw *hw,
2236                                              struct tid_ampdu_rx *tid_agg_rx,
2237                                              u16 head_seq_num)
2238 {
2239         int index;
2240
2241         while (seq_less(tid_agg_rx->head_seq_num, head_seq_num)) {
2242                 index = seq_sub(tid_agg_rx->head_seq_num, tid_agg_rx->ssn) %
2243                                                         tid_agg_rx->buf_size;
2244                 ieee80211_release_reorder_frame(hw, tid_agg_rx, index);
2245         }
2246 }
2247
2248 /*
2249  * Timeout (in jiffies) for skb's that are waiting in the RX reorder buffer. If
2250  * the skb was added to the buffer longer than this time ago, the earlier
2251  * frames that have not yet been received are assumed to be lost and the skb
2252  * can be released for processing. This may also release other skb's from the
2253  * reorder buffer if there are no additional gaps between the frames.
2254  */
2255 #define HT_RX_REORDER_BUF_TIMEOUT (HZ / 10)
2256
2257 /*
2258  * As this function belongs to the RX path it must be under
2259  * rcu_read_lock protection. It returns false if the frame
2260  * can be processed immediately, true if it was consumed.
2261  */
2262 static bool ieee80211_sta_manage_reorder_buf(struct ieee80211_hw *hw,
2263                                              struct tid_ampdu_rx *tid_agg_rx,
2264                                              struct sk_buff *skb)
2265 {
2266         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
2267         u16 sc = le16_to_cpu(hdr->seq_ctrl);
2268         u16 mpdu_seq_num = (sc & IEEE80211_SCTL_SEQ) >> 4;
2269         u16 head_seq_num, buf_size;
2270         int index;
2271
2272         buf_size = tid_agg_rx->buf_size;
2273         head_seq_num = tid_agg_rx->head_seq_num;
2274
2275         /* frame with out of date sequence number */
2276         if (seq_less(mpdu_seq_num, head_seq_num)) {
2277                 dev_kfree_skb(skb);
2278                 return true;
2279         }
2280
2281         /*
2282          * If frame the sequence number exceeds our buffering window
2283          * size release some previous frames to make room for this one.
2284          */
2285         if (!seq_less(mpdu_seq_num, head_seq_num + buf_size)) {
2286                 head_seq_num = seq_inc(seq_sub(mpdu_seq_num, buf_size));
2287                 /* release stored frames up to new head to stack */
2288                 ieee80211_release_reorder_frames(hw, tid_agg_rx, head_seq_num);
2289         }
2290
2291         /* Now the new frame is always in the range of the reordering buffer */
2292
2293         index = seq_sub(mpdu_seq_num, tid_agg_rx->ssn) % tid_agg_rx->buf_size;
2294
2295         /* check if we already stored this frame */
2296         if (tid_agg_rx->reorder_buf[index]) {
2297                 dev_kfree_skb(skb);
2298                 return true;
2299         }
2300
2301         /*
2302          * If the current MPDU is in the right order and nothing else
2303          * is stored we can process it directly, no need to buffer it.
2304          */
2305         if (mpdu_seq_num == tid_agg_rx->head_seq_num &&
2306             tid_agg_rx->stored_mpdu_num == 0) {
2307                 tid_agg_rx->head_seq_num = seq_inc(tid_agg_rx->head_seq_num);
2308                 return false;
2309         }
2310
2311         /* put the frame in the reordering buffer */
2312         tid_agg_rx->reorder_buf[index] = skb;
2313         tid_agg_rx->reorder_time[index] = jiffies;
2314         tid_agg_rx->stored_mpdu_num++;
2315         /* release the buffer until next missing frame */
2316         index = seq_sub(tid_agg_rx->head_seq_num, tid_agg_rx->ssn) %
2317                                                 tid_agg_rx->buf_size;
2318         if (!tid_agg_rx->reorder_buf[index] &&
2319             tid_agg_rx->stored_mpdu_num > 1) {
2320                 /*
2321                  * No buffers ready to be released, but check whether any
2322                  * frames in the reorder buffer have timed out.
2323                  */
2324                 int j;
2325                 int skipped = 1;
2326                 for (j = (index + 1) % tid_agg_rx->buf_size; j != index;
2327                      j = (j + 1) % tid_agg_rx->buf_size) {
2328                         if (!tid_agg_rx->reorder_buf[j]) {
2329                                 skipped++;
2330                                 continue;
2331                         }
2332                         if (!time_after(jiffies, tid_agg_rx->reorder_time[j] +
2333                                         HT_RX_REORDER_BUF_TIMEOUT))
2334                                 break;
2335
2336 #ifdef CONFIG_MAC80211_HT_DEBUG
2337                         if (net_ratelimit())
2338                                 printk(KERN_DEBUG "%s: release an RX reorder "
2339                                        "frame due to timeout on earlier "
2340                                        "frames\n",
2341                                        wiphy_name(hw->wiphy));
2342 #endif
2343                         ieee80211_release_reorder_frame(hw, tid_agg_rx, j);
2344
2345                         /*
2346                          * Increment the head seq# also for the skipped slots.
2347                          */
2348                         tid_agg_rx->head_seq_num =
2349                                 (tid_agg_rx->head_seq_num + skipped) & SEQ_MASK;
2350                         skipped = 0;
2351                 }
2352         } else while (tid_agg_rx->reorder_buf[index]) {
2353                 ieee80211_release_reorder_frame(hw, tid_agg_rx, index);
2354                 index = seq_sub(tid_agg_rx->head_seq_num, tid_agg_rx->ssn) %
2355                                                         tid_agg_rx->buf_size;
2356         }
2357
2358         return true;
2359 }
2360
2361 /*
2362  * Reorder MPDUs from A-MPDUs, keeping them on a buffer. Returns
2363  * true if the MPDU was buffered, false if it should be processed.
2364  */
2365 static bool ieee80211_rx_reorder_ampdu(struct ieee80211_local *local,
2366                                        struct sk_buff *skb)
2367 {
2368         struct ieee80211_hw *hw = &local->hw;
2369         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
2370         struct sta_info *sta;
2371         struct tid_ampdu_rx *tid_agg_rx;
2372         u16 sc;
2373         int tid;
2374
2375         if (!ieee80211_is_data_qos(hdr->frame_control))
2376                 return false;
2377
2378         /*
2379          * filter the QoS data rx stream according to
2380          * STA/TID and check if this STA/TID is on aggregation
2381          */
2382
2383         sta = sta_info_get(local, hdr->addr2);
2384         if (!sta)
2385                 return false;
2386
2387         tid = *ieee80211_get_qos_ctl(hdr) & IEEE80211_QOS_CTL_TID_MASK;
2388
2389         if (sta->ampdu_mlme.tid_state_rx[tid] != HT_AGG_STATE_OPERATIONAL)
2390                 return false;
2391
2392         tid_agg_rx = sta->ampdu_mlme.tid_rx[tid];
2393
2394         /* qos null data frames are excluded */
2395         if (unlikely(hdr->frame_control & cpu_to_le16(IEEE80211_STYPE_NULLFUNC)))
2396                 return false;
2397
2398         /* new, potentially un-ordered, ampdu frame - process it */
2399
2400         /* reset session timer */
2401         if (tid_agg_rx->timeout)
2402                 mod_timer(&tid_agg_rx->session_timer,
2403                           TU_TO_EXP_TIME(tid_agg_rx->timeout));
2404
2405         /* if this mpdu is fragmented - terminate rx aggregation session */
2406         sc = le16_to_cpu(hdr->seq_ctrl);
2407         if (sc & IEEE80211_SCTL_FRAG) {
2408                 ieee80211_sta_stop_rx_ba_session(sta->sdata, sta->sta.addr,
2409                         tid, 0, WLAN_REASON_QSTA_REQUIRE_SETUP);
2410                 dev_kfree_skb(skb);
2411                 return true;
2412         }
2413
2414         return ieee80211_sta_manage_reorder_buf(hw, tid_agg_rx, skb);
2415 }
2416
2417 /*
2418  * This is the receive path handler. It is called by a low level driver when an
2419  * 802.11 MPDU is received from the hardware.
2420  */
2421 void ieee80211_rx(struct ieee80211_hw *hw, struct sk_buff *skb)
2422 {
2423         struct ieee80211_local *local = hw_to_local(hw);
2424         struct ieee80211_rate *rate = NULL;
2425         struct ieee80211_supported_band *sband;
2426         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
2427
2428         WARN_ON_ONCE(softirq_count() == 0);
2429
2430         if (WARN_ON(status->band < 0 ||
2431                     status->band >= IEEE80211_NUM_BANDS))
2432                 goto drop;
2433
2434         sband = local->hw.wiphy->bands[status->band];
2435         if (WARN_ON(!sband))
2436                 goto drop;
2437
2438         /*
2439          * If we're suspending, it is possible although not too likely
2440          * that we'd be receiving frames after having already partially
2441          * quiesced the stack. We can't process such frames then since
2442          * that might, for example, cause stations to be added or other
2443          * driver callbacks be invoked.
2444          */
2445         if (unlikely(local->quiescing || local->suspended))
2446                 goto drop;
2447
2448         /*
2449          * The same happens when we're not even started,
2450          * but that's worth a warning.
2451          */
2452         if (WARN_ON(!local->started))
2453                 goto drop;
2454
2455         if (status->flag & RX_FLAG_HT) {
2456                 /*
2457                  * rate_idx is MCS index, which can be [0-76] as documented on:
2458                  *
2459                  * http://wireless.kernel.org/en/developers/Documentation/ieee80211/802.11n
2460                  *
2461                  * Anything else would be some sort of driver or hardware error.
2462                  * The driver should catch hardware errors.
2463                  */
2464                 if (WARN((status->rate_idx < 0 ||
2465                          status->rate_idx > 76),
2466                          "Rate marked as an HT rate but passed "
2467                          "status->rate_idx is not "
2468                          "an MCS index [0-76]: %d (0x%02x)\n",
2469                          status->rate_idx,
2470                          status->rate_idx))
2471                         goto drop;
2472         } else {
2473                 if (WARN_ON(status->rate_idx < 0 ||
2474                             status->rate_idx >= sband->n_bitrates))
2475                         goto drop;
2476                 rate = &sband->bitrates[status->rate_idx];
2477         }
2478
2479         /*
2480          * key references and virtual interfaces are protected using RCU
2481          * and this requires that we are in a read-side RCU section during
2482          * receive processing
2483          */
2484         rcu_read_lock();
2485
2486         /*
2487          * Frames with failed FCS/PLCP checksum are not returned,
2488          * all other frames are returned without radiotap header
2489          * if it was previously present.
2490          * Also, frames with less than 16 bytes are dropped.
2491          */
2492         skb = ieee80211_rx_monitor(local, skb, rate);
2493         if (!skb) {
2494                 rcu_read_unlock();
2495                 return;
2496         }
2497
2498         /*
2499          * In theory, the block ack reordering should happen after duplicate
2500          * removal (ieee80211_rx_h_check(), which is an RX handler). As such,
2501          * the call to ieee80211_rx_reorder_ampdu() should really be moved to
2502          * happen as a new RX handler between ieee80211_rx_h_check and
2503          * ieee80211_rx_h_decrypt. This cleanup may eventually happen, but for
2504          * the time being, the call can be here since RX reorder buf processing
2505          * will implicitly skip duplicates. We could, in theory at least,
2506          * process frames that ieee80211_rx_h_passive_scan would drop (e.g.,
2507          * frames from other than operational channel), but that should not
2508          * happen in normal networks.
2509          */
2510         if (!ieee80211_rx_reorder_ampdu(local, skb))
2511                 __ieee80211_rx_handle_packet(hw, skb, rate);
2512
2513         rcu_read_unlock();
2514
2515         return;
2516  drop:
2517         kfree_skb(skb);
2518 }
2519 EXPORT_SYMBOL(ieee80211_rx);
2520
2521 /* This is a version of the rx handler that can be called from hard irq
2522  * context. Post the skb on the queue and schedule the tasklet */
2523 void ieee80211_rx_irqsafe(struct ieee80211_hw *hw, struct sk_buff *skb)
2524 {
2525         struct ieee80211_local *local = hw_to_local(hw);
2526
2527         BUILD_BUG_ON(sizeof(struct ieee80211_rx_status) > sizeof(skb->cb));
2528
2529         skb->pkt_type = IEEE80211_RX_MSG;
2530         skb_queue_tail(&local->skb_queue, skb);
2531         tasklet_schedule(&local->tasklet);
2532 }
2533 EXPORT_SYMBOL(ieee80211_rx_irqsafe);