mac80211: fix scan channel race
[linux-2.6] / net / mac80211 / rx.c
1 /*
2  * Copyright 2002-2005, Instant802 Networks, Inc.
3  * Copyright 2005-2006, Devicescape Software, Inc.
4  * Copyright 2006-2007  Jiri Benc <jbenc@suse.cz>
5  * Copyright 2007       Johannes Berg <johannes@sipsolutions.net>
6  *
7  * This program is free software; you can redistribute it and/or modify
8  * it under the terms of the GNU General Public License version 2 as
9  * published by the Free Software Foundation.
10  */
11
12 #include <linux/jiffies.h>
13 #include <linux/kernel.h>
14 #include <linux/skbuff.h>
15 #include <linux/netdevice.h>
16 #include <linux/etherdevice.h>
17 #include <linux/rcupdate.h>
18 #include <net/mac80211.h>
19 #include <net/ieee80211_radiotap.h>
20
21 #include "ieee80211_i.h"
22 #include "driver-ops.h"
23 #include "led.h"
24 #include "mesh.h"
25 #include "wep.h"
26 #include "wpa.h"
27 #include "tkip.h"
28 #include "wme.h"
29
30 static u8 ieee80211_sta_manage_reorder_buf(struct ieee80211_hw *hw,
31                                            struct tid_ampdu_rx *tid_agg_rx,
32                                            struct sk_buff *skb,
33                                            struct ieee80211_rx_status *status,
34                                            u16 mpdu_seq_num,
35                                            int bar_req);
36 /*
37  * monitor mode reception
38  *
39  * This function cleans up the SKB, i.e. it removes all the stuff
40  * only useful for monitoring.
41  */
42 static struct sk_buff *remove_monitor_info(struct ieee80211_local *local,
43                                            struct sk_buff *skb,
44                                            int rtap_len)
45 {
46         skb_pull(skb, rtap_len);
47
48         if (local->hw.flags & IEEE80211_HW_RX_INCLUDES_FCS) {
49                 if (likely(skb->len > FCS_LEN))
50                         skb_trim(skb, skb->len - FCS_LEN);
51                 else {
52                         /* driver bug */
53                         WARN_ON(1);
54                         dev_kfree_skb(skb);
55                         skb = NULL;
56                 }
57         }
58
59         return skb;
60 }
61
62 static inline int should_drop_frame(struct ieee80211_rx_status *status,
63                                     struct sk_buff *skb,
64                                     int present_fcs_len,
65                                     int radiotap_len)
66 {
67         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
68
69         if (status->flag & (RX_FLAG_FAILED_FCS_CRC | RX_FLAG_FAILED_PLCP_CRC))
70                 return 1;
71         if (unlikely(skb->len < 16 + present_fcs_len + radiotap_len))
72                 return 1;
73         if (ieee80211_is_ctl(hdr->frame_control) &&
74             !ieee80211_is_pspoll(hdr->frame_control) &&
75             !ieee80211_is_back_req(hdr->frame_control))
76                 return 1;
77         return 0;
78 }
79
80 static int
81 ieee80211_rx_radiotap_len(struct ieee80211_local *local,
82                           struct ieee80211_rx_status *status)
83 {
84         int len;
85
86         /* always present fields */
87         len = sizeof(struct ieee80211_radiotap_header) + 9;
88
89         if (status->flag & RX_FLAG_TSFT)
90                 len += 8;
91         if (local->hw.flags & IEEE80211_HW_SIGNAL_DBM)
92                 len += 1;
93         if (local->hw.flags & IEEE80211_HW_NOISE_DBM)
94                 len += 1;
95
96         if (len & 1) /* padding for RX_FLAGS if necessary */
97                 len++;
98
99         /* make sure radiotap starts at a naturally aligned address */
100         if (len % 8)
101                 len = roundup(len, 8);
102
103         return len;
104 }
105
106 /*
107  * ieee80211_add_rx_radiotap_header - add radiotap header
108  *
109  * add a radiotap header containing all the fields which the hardware provided.
110  */
111 static void
112 ieee80211_add_rx_radiotap_header(struct ieee80211_local *local,
113                                  struct sk_buff *skb,
114                                  struct ieee80211_rx_status *status,
115                                  struct ieee80211_rate *rate,
116                                  int rtap_len)
117 {
118         struct ieee80211_radiotap_header *rthdr;
119         unsigned char *pos;
120
121         rthdr = (struct ieee80211_radiotap_header *)skb_push(skb, rtap_len);
122         memset(rthdr, 0, rtap_len);
123
124         /* radiotap header, set always present flags */
125         rthdr->it_present =
126                 cpu_to_le32((1 << IEEE80211_RADIOTAP_FLAGS) |
127                             (1 << IEEE80211_RADIOTAP_CHANNEL) |
128                             (1 << IEEE80211_RADIOTAP_ANTENNA) |
129                             (1 << IEEE80211_RADIOTAP_RX_FLAGS));
130         rthdr->it_len = cpu_to_le16(rtap_len);
131
132         pos = (unsigned char *)(rthdr+1);
133
134         /* the order of the following fields is important */
135
136         /* IEEE80211_RADIOTAP_TSFT */
137         if (status->flag & RX_FLAG_TSFT) {
138                 *(__le64 *)pos = cpu_to_le64(status->mactime);
139                 rthdr->it_present |=
140                         cpu_to_le32(1 << IEEE80211_RADIOTAP_TSFT);
141                 pos += 8;
142         }
143
144         /* IEEE80211_RADIOTAP_FLAGS */
145         if (local->hw.flags & IEEE80211_HW_RX_INCLUDES_FCS)
146                 *pos |= IEEE80211_RADIOTAP_F_FCS;
147         if (status->flag & (RX_FLAG_FAILED_FCS_CRC | RX_FLAG_FAILED_PLCP_CRC))
148                 *pos |= IEEE80211_RADIOTAP_F_BADFCS;
149         if (status->flag & RX_FLAG_SHORTPRE)
150                 *pos |= IEEE80211_RADIOTAP_F_SHORTPRE;
151         pos++;
152
153         /* IEEE80211_RADIOTAP_RATE */
154         if (status->flag & RX_FLAG_HT) {
155                 /*
156                  * TODO: add following information into radiotap header once
157                  * suitable fields are defined for it:
158                  * - MCS index (status->rate_idx)
159                  * - HT40 (status->flag & RX_FLAG_40MHZ)
160                  * - short-GI (status->flag & RX_FLAG_SHORT_GI)
161                  */
162                 *pos = 0;
163         } else {
164                 rthdr->it_present |= cpu_to_le32(1 << IEEE80211_RADIOTAP_RATE);
165                 *pos = rate->bitrate / 5;
166         }
167         pos++;
168
169         /* IEEE80211_RADIOTAP_CHANNEL */
170         *(__le16 *)pos = cpu_to_le16(status->freq);
171         pos += 2;
172         if (status->band == IEEE80211_BAND_5GHZ)
173                 *(__le16 *)pos = cpu_to_le16(IEEE80211_CHAN_OFDM |
174                                              IEEE80211_CHAN_5GHZ);
175         else if (rate->flags & IEEE80211_RATE_ERP_G)
176                 *(__le16 *)pos = cpu_to_le16(IEEE80211_CHAN_OFDM |
177                                              IEEE80211_CHAN_2GHZ);
178         else
179                 *(__le16 *)pos = cpu_to_le16(IEEE80211_CHAN_CCK |
180                                              IEEE80211_CHAN_2GHZ);
181         pos += 2;
182
183         /* IEEE80211_RADIOTAP_DBM_ANTSIGNAL */
184         if (local->hw.flags & IEEE80211_HW_SIGNAL_DBM) {
185                 *pos = status->signal;
186                 rthdr->it_present |=
187                         cpu_to_le32(1 << IEEE80211_RADIOTAP_DBM_ANTSIGNAL);
188                 pos++;
189         }
190
191         /* IEEE80211_RADIOTAP_DBM_ANTNOISE */
192         if (local->hw.flags & IEEE80211_HW_NOISE_DBM) {
193                 *pos = status->noise;
194                 rthdr->it_present |=
195                         cpu_to_le32(1 << IEEE80211_RADIOTAP_DBM_ANTNOISE);
196                 pos++;
197         }
198
199         /* IEEE80211_RADIOTAP_LOCK_QUALITY is missing */
200
201         /* IEEE80211_RADIOTAP_ANTENNA */
202         *pos = status->antenna;
203         pos++;
204
205         /* IEEE80211_RADIOTAP_DB_ANTNOISE is not used */
206
207         /* IEEE80211_RADIOTAP_RX_FLAGS */
208         /* ensure 2 byte alignment for the 2 byte field as required */
209         if ((pos - (unsigned char *)rthdr) & 1)
210                 pos++;
211         if (status->flag & RX_FLAG_FAILED_PLCP_CRC)
212                 *(__le16 *)pos |= cpu_to_le16(IEEE80211_RADIOTAP_F_RX_BADPLCP);
213         pos += 2;
214 }
215
216 /*
217  * This function copies a received frame to all monitor interfaces and
218  * returns a cleaned-up SKB that no longer includes the FCS nor the
219  * radiotap header the driver might have added.
220  */
221 static struct sk_buff *
222 ieee80211_rx_monitor(struct ieee80211_local *local, struct sk_buff *origskb,
223                      struct ieee80211_rx_status *status,
224                      struct ieee80211_rate *rate)
225 {
226         struct ieee80211_sub_if_data *sdata;
227         int needed_headroom = 0;
228         struct sk_buff *skb, *skb2;
229         struct net_device *prev_dev = NULL;
230         int present_fcs_len = 0;
231         int rtap_len = 0;
232
233         /*
234          * First, we may need to make a copy of the skb because
235          *  (1) we need to modify it for radiotap (if not present), and
236          *  (2) the other RX handlers will modify the skb we got.
237          *
238          * We don't need to, of course, if we aren't going to return
239          * the SKB because it has a bad FCS/PLCP checksum.
240          */
241         if (status->flag & RX_FLAG_RADIOTAP)
242                 rtap_len = ieee80211_get_radiotap_len(origskb->data);
243         else
244                 /* room for the radiotap header based on driver features */
245                 needed_headroom = ieee80211_rx_radiotap_len(local, status);
246
247         if (local->hw.flags & IEEE80211_HW_RX_INCLUDES_FCS)
248                 present_fcs_len = FCS_LEN;
249
250         if (!local->monitors) {
251                 if (should_drop_frame(status, origskb, present_fcs_len,
252                                       rtap_len)) {
253                         dev_kfree_skb(origskb);
254                         return NULL;
255                 }
256
257                 return remove_monitor_info(local, origskb, rtap_len);
258         }
259
260         if (should_drop_frame(status, origskb, present_fcs_len, rtap_len)) {
261                 /* only need to expand headroom if necessary */
262                 skb = origskb;
263                 origskb = NULL;
264
265                 /*
266                  * This shouldn't trigger often because most devices have an
267                  * RX header they pull before we get here, and that should
268                  * be big enough for our radiotap information. We should
269                  * probably export the length to drivers so that we can have
270                  * them allocate enough headroom to start with.
271                  */
272                 if (skb_headroom(skb) < needed_headroom &&
273                     pskb_expand_head(skb, needed_headroom, 0, GFP_ATOMIC)) {
274                         dev_kfree_skb(skb);
275                         return NULL;
276                 }
277         } else {
278                 /*
279                  * Need to make a copy and possibly remove radiotap header
280                  * and FCS from the original.
281                  */
282                 skb = skb_copy_expand(origskb, needed_headroom, 0, GFP_ATOMIC);
283
284                 origskb = remove_monitor_info(local, origskb, rtap_len);
285
286                 if (!skb)
287                         return origskb;
288         }
289
290         /* if necessary, prepend radiotap information */
291         if (!(status->flag & RX_FLAG_RADIOTAP))
292                 ieee80211_add_rx_radiotap_header(local, skb, status, rate,
293                                                  needed_headroom);
294
295         skb_reset_mac_header(skb);
296         skb->ip_summed = CHECKSUM_UNNECESSARY;
297         skb->pkt_type = PACKET_OTHERHOST;
298         skb->protocol = htons(ETH_P_802_2);
299
300         list_for_each_entry_rcu(sdata, &local->interfaces, list) {
301                 if (!netif_running(sdata->dev))
302                         continue;
303
304                 if (sdata->vif.type != NL80211_IFTYPE_MONITOR)
305                         continue;
306
307                 if (sdata->u.mntr_flags & MONITOR_FLAG_COOK_FRAMES)
308                         continue;
309
310                 if (prev_dev) {
311                         skb2 = skb_clone(skb, GFP_ATOMIC);
312                         if (skb2) {
313                                 skb2->dev = prev_dev;
314                                 netif_rx(skb2);
315                         }
316                 }
317
318                 prev_dev = sdata->dev;
319                 sdata->dev->stats.rx_packets++;
320                 sdata->dev->stats.rx_bytes += skb->len;
321         }
322
323         if (prev_dev) {
324                 skb->dev = prev_dev;
325                 netif_rx(skb);
326         } else
327                 dev_kfree_skb(skb);
328
329         return origskb;
330 }
331
332
333 static void ieee80211_parse_qos(struct ieee80211_rx_data *rx)
334 {
335         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
336         int tid;
337
338         /* does the frame have a qos control field? */
339         if (ieee80211_is_data_qos(hdr->frame_control)) {
340                 u8 *qc = ieee80211_get_qos_ctl(hdr);
341                 /* frame has qos control */
342                 tid = *qc & IEEE80211_QOS_CTL_TID_MASK;
343                 if (*qc & IEEE80211_QOS_CONTROL_A_MSDU_PRESENT)
344                         rx->flags |= IEEE80211_RX_AMSDU;
345                 else
346                         rx->flags &= ~IEEE80211_RX_AMSDU;
347         } else {
348                 /*
349                  * IEEE 802.11-2007, 7.1.3.4.1 ("Sequence Number field"):
350                  *
351                  *      Sequence numbers for management frames, QoS data
352                  *      frames with a broadcast/multicast address in the
353                  *      Address 1 field, and all non-QoS data frames sent
354                  *      by QoS STAs are assigned using an additional single
355                  *      modulo-4096 counter, [...]
356                  *
357                  * We also use that counter for non-QoS STAs.
358                  */
359                 tid = NUM_RX_DATA_QUEUES - 1;
360         }
361
362         rx->queue = tid;
363         /* Set skb->priority to 1d tag if highest order bit of TID is not set.
364          * For now, set skb->priority to 0 for other cases. */
365         rx->skb->priority = (tid > 7) ? 0 : tid;
366 }
367
368 /**
369  * DOC: Packet alignment
370  *
371  * Drivers always need to pass packets that are aligned to two-byte boundaries
372  * to the stack.
373  *
374  * Additionally, should, if possible, align the payload data in a way that
375  * guarantees that the contained IP header is aligned to a four-byte
376  * boundary. In the case of regular frames, this simply means aligning the
377  * payload to a four-byte boundary (because either the IP header is directly
378  * contained, or IV/RFC1042 headers that have a length divisible by four are
379  * in front of it).
380  *
381  * With A-MSDU frames, however, the payload data address must yield two modulo
382  * four because there are 14-byte 802.3 headers within the A-MSDU frames that
383  * push the IP header further back to a multiple of four again. Thankfully, the
384  * specs were sane enough this time around to require padding each A-MSDU
385  * subframe to a length that is a multiple of four.
386  *
387  * Padding like Atheros hardware adds which is inbetween the 802.11 header and
388  * the payload is not supported, the driver is required to move the 802.11
389  * header to be directly in front of the payload in that case.
390  */
391 static void ieee80211_verify_alignment(struct ieee80211_rx_data *rx)
392 {
393         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
394         int hdrlen;
395
396 #ifndef CONFIG_MAC80211_DEBUG_PACKET_ALIGNMENT
397         return;
398 #endif
399
400         if (WARN_ONCE((unsigned long)rx->skb->data & 1,
401                       "unaligned packet at 0x%p\n", rx->skb->data))
402                 return;
403
404         if (!ieee80211_is_data_present(hdr->frame_control))
405                 return;
406
407         hdrlen = ieee80211_hdrlen(hdr->frame_control);
408         if (rx->flags & IEEE80211_RX_AMSDU)
409                 hdrlen += ETH_HLEN;
410         WARN_ONCE(((unsigned long)(rx->skb->data + hdrlen)) & 3,
411                   "unaligned IP payload at 0x%p\n", rx->skb->data + hdrlen);
412 }
413
414
415 /* rx handlers */
416
417 static ieee80211_rx_result debug_noinline
418 ieee80211_rx_h_passive_scan(struct ieee80211_rx_data *rx)
419 {
420         struct ieee80211_local *local = rx->local;
421         struct sk_buff *skb = rx->skb;
422
423         if (unlikely(local->hw_scanning))
424                 return ieee80211_scan_rx(rx->sdata, skb, rx->status);
425
426         if (unlikely(local->sw_scanning)) {
427                 /* drop all the other packets during a software scan anyway */
428                 if (ieee80211_scan_rx(rx->sdata, skb, rx->status)
429                     != RX_QUEUED)
430                         dev_kfree_skb(skb);
431                 return RX_QUEUED;
432         }
433
434         if (unlikely(rx->flags & IEEE80211_RX_IN_SCAN)) {
435                 /* scanning finished during invoking of handlers */
436                 I802_DEBUG_INC(local->rx_handlers_drop_passive_scan);
437                 return RX_DROP_UNUSABLE;
438         }
439
440         return RX_CONTINUE;
441 }
442
443
444 static int ieee80211_is_unicast_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 static int ieee80211_is_multicast_robust_mgmt_frame(struct sk_buff *skb)
456 {
457         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
458
459         if (skb->len < 24 || !is_multicast_ether_addr(hdr->addr1))
460                 return 0;
461
462         return ieee80211_is_robust_mgmt_frame(hdr);
463 }
464
465
466 /* Get the BIP key index from MMIE; return -1 if this is not a BIP frame */
467 static int ieee80211_get_mmie_keyidx(struct sk_buff *skb)
468 {
469         struct ieee80211_mgmt *hdr = (struct ieee80211_mgmt *) skb->data;
470         struct ieee80211_mmie *mmie;
471
472         if (skb->len < 24 + sizeof(*mmie) ||
473             !is_multicast_ether_addr(hdr->da))
474                 return -1;
475
476         if (!ieee80211_is_robust_mgmt_frame((struct ieee80211_hdr *) hdr))
477                 return -1; /* not a robust management frame */
478
479         mmie = (struct ieee80211_mmie *)
480                 (skb->data + skb->len - sizeof(*mmie));
481         if (mmie->element_id != WLAN_EID_MMIE ||
482             mmie->length != sizeof(*mmie) - 2)
483                 return -1;
484
485         return le16_to_cpu(mmie->key_id);
486 }
487
488
489 static ieee80211_rx_result
490 ieee80211_rx_mesh_check(struct ieee80211_rx_data *rx)
491 {
492         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
493         unsigned int hdrlen = ieee80211_hdrlen(hdr->frame_control);
494
495         if (ieee80211_is_data(hdr->frame_control)) {
496                 if (!ieee80211_has_a4(hdr->frame_control))
497                         return RX_DROP_MONITOR;
498                 if (memcmp(hdr->addr4, rx->dev->dev_addr, ETH_ALEN) == 0)
499                         return RX_DROP_MONITOR;
500         }
501
502         /* If there is not an established peer link and this is not a peer link
503          * establisment frame, beacon or probe, drop the frame.
504          */
505
506         if (!rx->sta || sta_plink_state(rx->sta) != PLINK_ESTAB) {
507                 struct ieee80211_mgmt *mgmt;
508
509                 if (!ieee80211_is_mgmt(hdr->frame_control))
510                         return RX_DROP_MONITOR;
511
512                 if (ieee80211_is_action(hdr->frame_control)) {
513                         mgmt = (struct ieee80211_mgmt *)hdr;
514                         if (mgmt->u.action.category != PLINK_CATEGORY)
515                                 return RX_DROP_MONITOR;
516                         return RX_CONTINUE;
517                 }
518
519                 if (ieee80211_is_probe_req(hdr->frame_control) ||
520                     ieee80211_is_probe_resp(hdr->frame_control) ||
521                     ieee80211_is_beacon(hdr->frame_control))
522                         return RX_CONTINUE;
523
524                 return RX_DROP_MONITOR;
525
526         }
527
528 #define msh_h_get(h, l) ((struct ieee80211s_hdr *) ((u8 *)h + l))
529
530         if (ieee80211_is_data(hdr->frame_control) &&
531             is_multicast_ether_addr(hdr->addr1) &&
532             mesh_rmc_check(hdr->addr4, msh_h_get(hdr, hdrlen), rx->sdata))
533                 return RX_DROP_MONITOR;
534 #undef msh_h_get
535
536         return RX_CONTINUE;
537 }
538
539
540 static ieee80211_rx_result debug_noinline
541 ieee80211_rx_h_check(struct ieee80211_rx_data *rx)
542 {
543         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
544
545         /* Drop duplicate 802.11 retransmissions (IEEE 802.11 Chap. 9.2.9) */
546         if (rx->sta && !is_multicast_ether_addr(hdr->addr1)) {
547                 if (unlikely(ieee80211_has_retry(hdr->frame_control) &&
548                              rx->sta->last_seq_ctrl[rx->queue] ==
549                              hdr->seq_ctrl)) {
550                         if (rx->flags & IEEE80211_RX_RA_MATCH) {
551                                 rx->local->dot11FrameDuplicateCount++;
552                                 rx->sta->num_duplicates++;
553                         }
554                         return RX_DROP_MONITOR;
555                 } else
556                         rx->sta->last_seq_ctrl[rx->queue] = hdr->seq_ctrl;
557         }
558
559         if (unlikely(rx->skb->len < 16)) {
560                 I802_DEBUG_INC(rx->local->rx_handlers_drop_short);
561                 return RX_DROP_MONITOR;
562         }
563
564         /* Drop disallowed frame classes based on STA auth/assoc state;
565          * IEEE 802.11, Chap 5.5.
566          *
567          * mac80211 filters only based on association state, i.e. it drops
568          * Class 3 frames from not associated stations. hostapd sends
569          * deauth/disassoc frames when needed. In addition, hostapd is
570          * responsible for filtering on both auth and assoc states.
571          */
572
573         if (ieee80211_vif_is_mesh(&rx->sdata->vif))
574                 return ieee80211_rx_mesh_check(rx);
575
576         if (unlikely((ieee80211_is_data(hdr->frame_control) ||
577                       ieee80211_is_pspoll(hdr->frame_control)) &&
578                      rx->sdata->vif.type != NL80211_IFTYPE_ADHOC &&
579                      (!rx->sta || !test_sta_flags(rx->sta, WLAN_STA_ASSOC)))) {
580                 if ((!ieee80211_has_fromds(hdr->frame_control) &&
581                      !ieee80211_has_tods(hdr->frame_control) &&
582                      ieee80211_is_data(hdr->frame_control)) ||
583                     !(rx->flags & IEEE80211_RX_RA_MATCH)) {
584                         /* Drop IBSS frames and frames for other hosts
585                          * silently. */
586                         return RX_DROP_MONITOR;
587                 }
588
589                 return RX_DROP_MONITOR;
590         }
591
592         return RX_CONTINUE;
593 }
594
595
596 static ieee80211_rx_result debug_noinline
597 ieee80211_rx_h_decrypt(struct ieee80211_rx_data *rx)
598 {
599         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->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         if (!ieee80211_has_protected(hdr->frame_control)) {
634                 if (!ieee80211_is_mgmt(hdr->frame_control) ||
635                     rx->sta == NULL || !test_sta_flags(rx->sta, WLAN_STA_MFP))
636                         return RX_CONTINUE;
637                 mmie_keyidx = ieee80211_get_mmie_keyidx(rx->skb);
638                 if (mmie_keyidx < 0)
639                         return RX_CONTINUE;
640         }
641
642         /*
643          * No point in finding a key and decrypting if the frame is neither
644          * addressed to us nor a multicast frame.
645          */
646         if (!(rx->flags & IEEE80211_RX_RA_MATCH))
647                 return RX_CONTINUE;
648
649         if (rx->sta)
650                 stakey = rcu_dereference(rx->sta->key);
651
652         if (!is_multicast_ether_addr(hdr->addr1) && stakey) {
653                 rx->key = stakey;
654         } else if (mmie_keyidx >= 0) {
655                 /* Broadcast/multicast robust management frame / BIP */
656                 if ((rx->status->flag & RX_FLAG_DECRYPTED) &&
657                     (rx->status->flag & RX_FLAG_IV_STRIPPED))
658                         return RX_CONTINUE;
659
660                 if (mmie_keyidx < NUM_DEFAULT_KEYS ||
661                     mmie_keyidx >= NUM_DEFAULT_KEYS + NUM_DEFAULT_MGMT_KEYS)
662                         return RX_DROP_MONITOR; /* unexpected BIP keyidx */
663                 rx->key = rcu_dereference(rx->sdata->keys[mmie_keyidx]);
664         } else {
665                 /*
666                  * The device doesn't give us the IV so we won't be
667                  * able to look up the key. That's ok though, we
668                  * don't need to decrypt the frame, we just won't
669                  * be able to keep statistics accurate.
670                  * Except for key threshold notifications, should
671                  * we somehow allow the driver to tell us which key
672                  * the hardware used if this flag is set?
673                  */
674                 if ((rx->status->flag & RX_FLAG_DECRYPTED) &&
675                     (rx->status->flag & RX_FLAG_IV_STRIPPED))
676                         return RX_CONTINUE;
677
678                 hdrlen = ieee80211_hdrlen(hdr->frame_control);
679
680                 if (rx->skb->len < 8 + hdrlen)
681                         return RX_DROP_UNUSABLE; /* TODO: count this? */
682
683                 /*
684                  * no need to call ieee80211_wep_get_keyidx,
685                  * it verifies a bunch of things we've done already
686                  */
687                 keyidx = rx->skb->data[hdrlen + 3] >> 6;
688
689                 rx->key = rcu_dereference(rx->sdata->keys[keyidx]);
690
691                 /*
692                  * RSNA-protected unicast frames should always be sent with
693                  * pairwise or station-to-station keys, but for WEP we allow
694                  * using a key index as well.
695                  */
696                 if (rx->key && rx->key->conf.alg != ALG_WEP &&
697                     !is_multicast_ether_addr(hdr->addr1))
698                         rx->key = NULL;
699         }
700
701         if (rx->key) {
702                 rx->key->tx_rx_count++;
703                 /* TODO: add threshold stuff again */
704         } else {
705                 return RX_DROP_MONITOR;
706         }
707
708         /* Check for weak IVs if possible */
709         if (rx->sta && rx->key->conf.alg == ALG_WEP &&
710             ieee80211_is_data(hdr->frame_control) &&
711             (!(rx->status->flag & RX_FLAG_IV_STRIPPED) ||
712              !(rx->status->flag & RX_FLAG_DECRYPTED)) &&
713             ieee80211_wep_is_weak_iv(rx->skb, rx->key))
714                 rx->sta->wep_weak_iv_count++;
715
716         switch (rx->key->conf.alg) {
717         case ALG_WEP:
718                 result = ieee80211_crypto_wep_decrypt(rx);
719                 break;
720         case ALG_TKIP:
721                 result = ieee80211_crypto_tkip_decrypt(rx);
722                 break;
723         case ALG_CCMP:
724                 result = ieee80211_crypto_ccmp_decrypt(rx);
725                 break;
726         case ALG_AES_CMAC:
727                 result = ieee80211_crypto_aes_cmac_decrypt(rx);
728                 break;
729         }
730
731         /* either the frame has been decrypted or will be dropped */
732         rx->status->flag |= RX_FLAG_DECRYPTED;
733
734         return result;
735 }
736
737 static ieee80211_rx_result debug_noinline
738 ieee80211_rx_h_check_more_data(struct ieee80211_rx_data *rx)
739 {
740         struct ieee80211_local *local;
741         struct ieee80211_hdr *hdr;
742         struct sk_buff *skb;
743
744         local = rx->local;
745         skb = rx->skb;
746         hdr = (struct ieee80211_hdr *) skb->data;
747
748         if (!local->pspolling)
749                 return RX_CONTINUE;
750
751         if (!ieee80211_has_fromds(hdr->frame_control))
752                 /* this is not from AP */
753                 return RX_CONTINUE;
754
755         if (!ieee80211_is_data(hdr->frame_control))
756                 return RX_CONTINUE;
757
758         if (!ieee80211_has_moredata(hdr->frame_control)) {
759                 /* AP has no more frames buffered for us */
760                 local->pspolling = false;
761                 return RX_CONTINUE;
762         }
763
764         /* more data bit is set, let's request a new frame from the AP */
765         ieee80211_send_pspoll(local, rx->sdata);
766
767         return RX_CONTINUE;
768 }
769
770 static void ap_sta_ps_start(struct sta_info *sta)
771 {
772         struct ieee80211_sub_if_data *sdata = sta->sdata;
773         struct ieee80211_local *local = sdata->local;
774
775         atomic_inc(&sdata->bss->num_sta_ps);
776         set_and_clear_sta_flags(sta, WLAN_STA_PS, WLAN_STA_PSPOLL);
777         drv_sta_notify(local, &sdata->vif, STA_NOTIFY_SLEEP, &sta->sta);
778 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
779         printk(KERN_DEBUG "%s: STA %pM aid %d enters power save mode\n",
780                sdata->dev->name, sta->sta.addr, sta->sta.aid);
781 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
782 }
783
784 static int ap_sta_ps_end(struct sta_info *sta)
785 {
786         struct ieee80211_sub_if_data *sdata = sta->sdata;
787         struct ieee80211_local *local = sdata->local;
788         struct sk_buff *skb;
789         int sent = 0;
790
791         atomic_dec(&sdata->bss->num_sta_ps);
792
793         clear_sta_flags(sta, WLAN_STA_PS | WLAN_STA_PSPOLL);
794         drv_sta_notify(local, &sdata->vif, STA_NOTIFY_AWAKE, &sta->sta);
795
796         if (!skb_queue_empty(&sta->ps_tx_buf))
797                 sta_info_clear_tim_bit(sta);
798
799 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
800         printk(KERN_DEBUG "%s: STA %pM aid %d exits power save mode\n",
801                sdata->dev->name, sta->sta.addr, sta->sta.aid);
802 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
803
804         /* Send all buffered frames to the station */
805         while ((skb = skb_dequeue(&sta->tx_filtered)) != NULL) {
806                 sent++;
807                 skb->requeue = 1;
808                 dev_queue_xmit(skb);
809         }
810         while ((skb = skb_dequeue(&sta->ps_tx_buf)) != NULL) {
811                 local->total_ps_buffered--;
812                 sent++;
813 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
814                 printk(KERN_DEBUG "%s: STA %pM aid %d send PS frame "
815                        "since STA not sleeping anymore\n", sdata->dev->name,
816                        sta->sta.addr, sta->sta.aid);
817 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
818                 skb->requeue = 1;
819                 dev_queue_xmit(skb);
820         }
821
822         return sent;
823 }
824
825 static ieee80211_rx_result debug_noinline
826 ieee80211_rx_h_sta_process(struct ieee80211_rx_data *rx)
827 {
828         struct sta_info *sta = rx->sta;
829         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
830
831         if (!sta)
832                 return RX_CONTINUE;
833
834         /* Update last_rx only for IBSS packets which are for the current
835          * BSSID to avoid keeping the current IBSS network alive in cases where
836          * other STAs are using different BSSID. */
837         if (rx->sdata->vif.type == NL80211_IFTYPE_ADHOC) {
838                 u8 *bssid = ieee80211_get_bssid(hdr, rx->skb->len,
839                                                 NL80211_IFTYPE_ADHOC);
840                 if (compare_ether_addr(bssid, rx->sdata->u.ibss.bssid) == 0)
841                         sta->last_rx = jiffies;
842         } else
843         if (!is_multicast_ether_addr(hdr->addr1) ||
844             rx->sdata->vif.type == NL80211_IFTYPE_STATION) {
845                 /* Update last_rx only for unicast frames in order to prevent
846                  * the Probe Request frames (the only broadcast frames from a
847                  * STA in infrastructure mode) from keeping a connection alive.
848                  * Mesh beacons will update last_rx when if they are found to
849                  * match the current local configuration when processed.
850                  */
851                 if (rx->sdata->vif.type == NL80211_IFTYPE_STATION &&
852                     ieee80211_is_beacon(hdr->frame_control)) {
853                         rx->sdata->u.mgd.last_beacon = jiffies;
854                 } else
855                         sta->last_rx = jiffies;
856         }
857
858         if (!(rx->flags & IEEE80211_RX_RA_MATCH))
859                 return RX_CONTINUE;
860
861         if (rx->sdata->vif.type == NL80211_IFTYPE_STATION)
862                 ieee80211_sta_rx_notify(rx->sdata, hdr);
863
864         sta->rx_fragments++;
865         sta->rx_bytes += rx->skb->len;
866         sta->last_signal = rx->status->signal;
867         sta->last_qual = rx->status->qual;
868         sta->last_noise = rx->status->noise;
869
870         /*
871          * Change STA power saving mode only at the end of a frame
872          * exchange sequence.
873          */
874         if (!ieee80211_has_morefrags(hdr->frame_control) &&
875             (rx->sdata->vif.type == NL80211_IFTYPE_AP ||
876              rx->sdata->vif.type == NL80211_IFTYPE_AP_VLAN)) {
877                 if (test_sta_flags(sta, WLAN_STA_PS)) {
878                         /*
879                          * Ignore doze->wake transitions that are
880                          * indicated by non-data frames, the standard
881                          * is unclear here, but for example going to
882                          * PS mode and then scanning would cause a
883                          * doze->wake transition for the probe request,
884                          * and that is clearly undesirable.
885                          */
886                         if (ieee80211_is_data(hdr->frame_control) &&
887                             !ieee80211_has_pm(hdr->frame_control))
888                                 rx->sent_ps_buffered += ap_sta_ps_end(sta);
889                 } else {
890                         if (ieee80211_has_pm(hdr->frame_control))
891                                 ap_sta_ps_start(sta);
892                 }
893         }
894
895         /* Drop data::nullfunc frames silently, since they are used only to
896          * control station power saving mode. */
897         if (ieee80211_is_nullfunc(hdr->frame_control)) {
898                 I802_DEBUG_INC(rx->local->rx_handlers_drop_nullfunc);
899                 /* Update counter and free packet here to avoid counting this
900                  * as a dropped packed. */
901                 sta->rx_packets++;
902                 dev_kfree_skb(rx->skb);
903                 return RX_QUEUED;
904         }
905
906         return RX_CONTINUE;
907 } /* ieee80211_rx_h_sta_process */
908
909 static inline struct ieee80211_fragment_entry *
910 ieee80211_reassemble_add(struct ieee80211_sub_if_data *sdata,
911                          unsigned int frag, unsigned int seq, int rx_queue,
912                          struct sk_buff **skb)
913 {
914         struct ieee80211_fragment_entry *entry;
915         int idx;
916
917         idx = sdata->fragment_next;
918         entry = &sdata->fragments[sdata->fragment_next++];
919         if (sdata->fragment_next >= IEEE80211_FRAGMENT_MAX)
920                 sdata->fragment_next = 0;
921
922         if (!skb_queue_empty(&entry->skb_list)) {
923 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG
924                 struct ieee80211_hdr *hdr =
925                         (struct ieee80211_hdr *) entry->skb_list.next->data;
926                 printk(KERN_DEBUG "%s: RX reassembly removed oldest "
927                        "fragment entry (idx=%d age=%lu seq=%d last_frag=%d "
928                        "addr1=%pM addr2=%pM\n",
929                        sdata->dev->name, idx,
930                        jiffies - entry->first_frag_time, entry->seq,
931                        entry->last_frag, hdr->addr1, hdr->addr2);
932 #endif
933                 __skb_queue_purge(&entry->skb_list);
934         }
935
936         __skb_queue_tail(&entry->skb_list, *skb); /* no need for locking */
937         *skb = NULL;
938         entry->first_frag_time = jiffies;
939         entry->seq = seq;
940         entry->rx_queue = rx_queue;
941         entry->last_frag = frag;
942         entry->ccmp = 0;
943         entry->extra_len = 0;
944
945         return entry;
946 }
947
948 static inline struct ieee80211_fragment_entry *
949 ieee80211_reassemble_find(struct ieee80211_sub_if_data *sdata,
950                           unsigned int frag, unsigned int seq,
951                           int rx_queue, struct ieee80211_hdr *hdr)
952 {
953         struct ieee80211_fragment_entry *entry;
954         int i, idx;
955
956         idx = sdata->fragment_next;
957         for (i = 0; i < IEEE80211_FRAGMENT_MAX; i++) {
958                 struct ieee80211_hdr *f_hdr;
959
960                 idx--;
961                 if (idx < 0)
962                         idx = IEEE80211_FRAGMENT_MAX - 1;
963
964                 entry = &sdata->fragments[idx];
965                 if (skb_queue_empty(&entry->skb_list) || entry->seq != seq ||
966                     entry->rx_queue != rx_queue ||
967                     entry->last_frag + 1 != frag)
968                         continue;
969
970                 f_hdr = (struct ieee80211_hdr *)entry->skb_list.next->data;
971
972                 /*
973                  * Check ftype and addresses are equal, else check next fragment
974                  */
975                 if (((hdr->frame_control ^ f_hdr->frame_control) &
976                      cpu_to_le16(IEEE80211_FCTL_FTYPE)) ||
977                     compare_ether_addr(hdr->addr1, f_hdr->addr1) != 0 ||
978                     compare_ether_addr(hdr->addr2, f_hdr->addr2) != 0)
979                         continue;
980
981                 if (time_after(jiffies, entry->first_frag_time + 2 * HZ)) {
982                         __skb_queue_purge(&entry->skb_list);
983                         continue;
984                 }
985                 return entry;
986         }
987
988         return NULL;
989 }
990
991 static ieee80211_rx_result debug_noinline
992 ieee80211_rx_h_defragment(struct ieee80211_rx_data *rx)
993 {
994         struct ieee80211_hdr *hdr;
995         u16 sc;
996         __le16 fc;
997         unsigned int frag, seq;
998         struct ieee80211_fragment_entry *entry;
999         struct sk_buff *skb;
1000
1001         hdr = (struct ieee80211_hdr *)rx->skb->data;
1002         fc = hdr->frame_control;
1003         sc = le16_to_cpu(hdr->seq_ctrl);
1004         frag = sc & IEEE80211_SCTL_FRAG;
1005
1006         if (likely((!ieee80211_has_morefrags(fc) && frag == 0) ||
1007                    (rx->skb)->len < 24 ||
1008                    is_multicast_ether_addr(hdr->addr1))) {
1009                 /* not fragmented */
1010                 goto out;
1011         }
1012         I802_DEBUG_INC(rx->local->rx_handlers_fragments);
1013
1014         seq = (sc & IEEE80211_SCTL_SEQ) >> 4;
1015
1016         if (frag == 0) {
1017                 /* This is the first fragment of a new frame. */
1018                 entry = ieee80211_reassemble_add(rx->sdata, frag, seq,
1019                                                  rx->queue, &(rx->skb));
1020                 if (rx->key && rx->key->conf.alg == ALG_CCMP &&
1021                     ieee80211_has_protected(fc)) {
1022                         /* Store CCMP PN so that we can verify that the next
1023                          * fragment has a sequential PN value. */
1024                         entry->ccmp = 1;
1025                         memcpy(entry->last_pn,
1026                                rx->key->u.ccmp.rx_pn[rx->queue],
1027                                CCMP_PN_LEN);
1028                 }
1029                 return RX_QUEUED;
1030         }
1031
1032         /* This is a fragment for a frame that should already be pending in
1033          * fragment cache. Add this fragment to the end of the pending entry.
1034          */
1035         entry = ieee80211_reassemble_find(rx->sdata, frag, seq, rx->queue, hdr);
1036         if (!entry) {
1037                 I802_DEBUG_INC(rx->local->rx_handlers_drop_defrag);
1038                 return RX_DROP_MONITOR;
1039         }
1040
1041         /* Verify that MPDUs within one MSDU have sequential PN values.
1042          * (IEEE 802.11i, 8.3.3.4.5) */
1043         if (entry->ccmp) {
1044                 int i;
1045                 u8 pn[CCMP_PN_LEN], *rpn;
1046                 if (!rx->key || rx->key->conf.alg != ALG_CCMP)
1047                         return RX_DROP_UNUSABLE;
1048                 memcpy(pn, entry->last_pn, CCMP_PN_LEN);
1049                 for (i = CCMP_PN_LEN - 1; i >= 0; i--) {
1050                         pn[i]++;
1051                         if (pn[i])
1052                                 break;
1053                 }
1054                 rpn = rx->key->u.ccmp.rx_pn[rx->queue];
1055                 if (memcmp(pn, rpn, CCMP_PN_LEN))
1056                         return RX_DROP_UNUSABLE;
1057                 memcpy(entry->last_pn, pn, CCMP_PN_LEN);
1058         }
1059
1060         skb_pull(rx->skb, ieee80211_hdrlen(fc));
1061         __skb_queue_tail(&entry->skb_list, rx->skb);
1062         entry->last_frag = frag;
1063         entry->extra_len += rx->skb->len;
1064         if (ieee80211_has_morefrags(fc)) {
1065                 rx->skb = NULL;
1066                 return RX_QUEUED;
1067         }
1068
1069         rx->skb = __skb_dequeue(&entry->skb_list);
1070         if (skb_tailroom(rx->skb) < entry->extra_len) {
1071                 I802_DEBUG_INC(rx->local->rx_expand_skb_head2);
1072                 if (unlikely(pskb_expand_head(rx->skb, 0, entry->extra_len,
1073                                               GFP_ATOMIC))) {
1074                         I802_DEBUG_INC(rx->local->rx_handlers_drop_defrag);
1075                         __skb_queue_purge(&entry->skb_list);
1076                         return RX_DROP_UNUSABLE;
1077                 }
1078         }
1079         while ((skb = __skb_dequeue(&entry->skb_list))) {
1080                 memcpy(skb_put(rx->skb, skb->len), skb->data, skb->len);
1081                 dev_kfree_skb(skb);
1082         }
1083
1084         /* Complete frame has been reassembled - process it now */
1085         rx->flags |= IEEE80211_RX_FRAGMENTED;
1086
1087  out:
1088         if (rx->sta)
1089                 rx->sta->rx_packets++;
1090         if (is_multicast_ether_addr(hdr->addr1))
1091                 rx->local->dot11MulticastReceivedFrameCount++;
1092         else
1093                 ieee80211_led_rx(rx->local);
1094         return RX_CONTINUE;
1095 }
1096
1097 static ieee80211_rx_result debug_noinline
1098 ieee80211_rx_h_ps_poll(struct ieee80211_rx_data *rx)
1099 {
1100         struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(rx->dev);
1101         struct sk_buff *skb;
1102         int no_pending_pkts;
1103         __le16 fc = ((struct ieee80211_hdr *)rx->skb->data)->frame_control;
1104
1105         if (likely(!rx->sta || !ieee80211_is_pspoll(fc) ||
1106                    !(rx->flags & IEEE80211_RX_RA_MATCH)))
1107                 return RX_CONTINUE;
1108
1109         if ((sdata->vif.type != NL80211_IFTYPE_AP) &&
1110             (sdata->vif.type != NL80211_IFTYPE_AP_VLAN))
1111                 return RX_DROP_UNUSABLE;
1112
1113         skb = skb_dequeue(&rx->sta->tx_filtered);
1114         if (!skb) {
1115                 skb = skb_dequeue(&rx->sta->ps_tx_buf);
1116                 if (skb)
1117                         rx->local->total_ps_buffered--;
1118         }
1119         no_pending_pkts = skb_queue_empty(&rx->sta->tx_filtered) &&
1120                 skb_queue_empty(&rx->sta->ps_tx_buf);
1121
1122         if (skb) {
1123                 struct ieee80211_hdr *hdr =
1124                         (struct ieee80211_hdr *) skb->data;
1125
1126                 /*
1127                  * Tell TX path to send one frame even though the STA may
1128                  * still remain is PS mode after this frame exchange.
1129                  */
1130                 set_sta_flags(rx->sta, WLAN_STA_PSPOLL);
1131
1132 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
1133                 printk(KERN_DEBUG "STA %pM aid %d: PS Poll (entries after %d)\n",
1134                        rx->sta->sta.addr, rx->sta->sta.aid,
1135                        skb_queue_len(&rx->sta->ps_tx_buf));
1136 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
1137
1138                 /* Use MoreData flag to indicate whether there are more
1139                  * buffered frames for this STA */
1140                 if (no_pending_pkts)
1141                         hdr->frame_control &= cpu_to_le16(~IEEE80211_FCTL_MOREDATA);
1142                 else
1143                         hdr->frame_control |= cpu_to_le16(IEEE80211_FCTL_MOREDATA);
1144
1145                 dev_queue_xmit(skb);
1146
1147                 if (no_pending_pkts)
1148                         sta_info_clear_tim_bit(rx->sta);
1149 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
1150         } else if (!rx->sent_ps_buffered) {
1151                 /*
1152                  * FIXME: This can be the result of a race condition between
1153                  *        us expiring a frame and the station polling for it.
1154                  *        Should we send it a null-func frame indicating we
1155                  *        have nothing buffered for it?
1156                  */
1157                 printk(KERN_DEBUG "%s: STA %pM sent PS Poll even "
1158                        "though there are no buffered frames for it\n",
1159                        rx->dev->name, rx->sta->sta.addr);
1160 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
1161         }
1162
1163         /* Free PS Poll skb here instead of returning RX_DROP that would
1164          * count as an dropped frame. */
1165         dev_kfree_skb(rx->skb);
1166
1167         return RX_QUEUED;
1168 }
1169
1170 static ieee80211_rx_result debug_noinline
1171 ieee80211_rx_h_remove_qos_control(struct ieee80211_rx_data *rx)
1172 {
1173         u8 *data = rx->skb->data;
1174         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)data;
1175
1176         if (!ieee80211_is_data_qos(hdr->frame_control))
1177                 return RX_CONTINUE;
1178
1179         /* remove the qos control field, update frame type and meta-data */
1180         memmove(data + IEEE80211_QOS_CTL_LEN, data,
1181                 ieee80211_hdrlen(hdr->frame_control) - IEEE80211_QOS_CTL_LEN);
1182         hdr = (struct ieee80211_hdr *)skb_pull(rx->skb, IEEE80211_QOS_CTL_LEN);
1183         /* change frame type to non QOS */
1184         hdr->frame_control &= ~cpu_to_le16(IEEE80211_STYPE_QOS_DATA);
1185
1186         return RX_CONTINUE;
1187 }
1188
1189 static int
1190 ieee80211_802_1x_port_control(struct ieee80211_rx_data *rx)
1191 {
1192         if (unlikely(!rx->sta ||
1193             !test_sta_flags(rx->sta, WLAN_STA_AUTHORIZED)))
1194                 return -EACCES;
1195
1196         return 0;
1197 }
1198
1199 static int
1200 ieee80211_drop_unencrypted(struct ieee80211_rx_data *rx, __le16 fc)
1201 {
1202         /*
1203          * Pass through unencrypted frames if the hardware has
1204          * decrypted them already.
1205          */
1206         if (rx->status->flag & RX_FLAG_DECRYPTED)
1207                 return 0;
1208
1209         /* Drop unencrypted frames if key is set. */
1210         if (unlikely(!ieee80211_has_protected(fc) &&
1211                      !ieee80211_is_nullfunc(fc) &&
1212                      (!ieee80211_is_mgmt(fc) ||
1213                       (ieee80211_is_unicast_robust_mgmt_frame(rx->skb) &&
1214                        rx->sta && test_sta_flags(rx->sta, WLAN_STA_MFP))) &&
1215                      (rx->key || rx->sdata->drop_unencrypted)))
1216                 return -EACCES;
1217         /* BIP does not use Protected field, so need to check MMIE */
1218         if (unlikely(rx->sta && test_sta_flags(rx->sta, WLAN_STA_MFP) &&
1219                      ieee80211_is_multicast_robust_mgmt_frame(rx->skb) &&
1220                      ieee80211_get_mmie_keyidx(rx->skb) < 0 &&
1221                      (rx->key || rx->sdata->drop_unencrypted)))
1222                 return -EACCES;
1223
1224         return 0;
1225 }
1226
1227 static int
1228 ieee80211_data_to_8023(struct ieee80211_rx_data *rx)
1229 {
1230         struct net_device *dev = rx->dev;
1231         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) rx->skb->data;
1232         u16 hdrlen, ethertype;
1233         u8 *payload;
1234         u8 dst[ETH_ALEN];
1235         u8 src[ETH_ALEN] __aligned(2);
1236         struct sk_buff *skb = rx->skb;
1237         struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
1238
1239         if (unlikely(!ieee80211_is_data_present(hdr->frame_control)))
1240                 return -1;
1241
1242         hdrlen = ieee80211_hdrlen(hdr->frame_control);
1243
1244         /* convert IEEE 802.11 header + possible LLC headers into Ethernet
1245          * header
1246          * IEEE 802.11 address fields:
1247          * ToDS FromDS Addr1 Addr2 Addr3 Addr4
1248          *   0     0   DA    SA    BSSID n/a
1249          *   0     1   DA    BSSID SA    n/a
1250          *   1     0   BSSID SA    DA    n/a
1251          *   1     1   RA    TA    DA    SA
1252          */
1253         memcpy(dst, ieee80211_get_DA(hdr), ETH_ALEN);
1254         memcpy(src, ieee80211_get_SA(hdr), ETH_ALEN);
1255
1256         switch (hdr->frame_control &
1257                 cpu_to_le16(IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS)) {
1258         case cpu_to_le16(IEEE80211_FCTL_TODS):
1259                 if (unlikely(sdata->vif.type != NL80211_IFTYPE_AP &&
1260                              sdata->vif.type != NL80211_IFTYPE_AP_VLAN))
1261                         return -1;
1262                 break;
1263         case cpu_to_le16(IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS):
1264                 if (unlikely(sdata->vif.type != NL80211_IFTYPE_WDS &&
1265                              sdata->vif.type != NL80211_IFTYPE_MESH_POINT))
1266                         return -1;
1267                 if (ieee80211_vif_is_mesh(&sdata->vif)) {
1268                         struct ieee80211s_hdr *meshdr = (struct ieee80211s_hdr *)
1269                                 (skb->data + hdrlen);
1270                         hdrlen += ieee80211_get_mesh_hdrlen(meshdr);
1271                         if (meshdr->flags & MESH_FLAGS_AE_A5_A6) {
1272                                 memcpy(dst, meshdr->eaddr1, ETH_ALEN);
1273                                 memcpy(src, meshdr->eaddr2, ETH_ALEN);
1274                         }
1275                 }
1276                 break;
1277         case cpu_to_le16(IEEE80211_FCTL_FROMDS):
1278                 if (sdata->vif.type != NL80211_IFTYPE_STATION ||
1279                     (is_multicast_ether_addr(dst) &&
1280                      !compare_ether_addr(src, dev->dev_addr)))
1281                         return -1;
1282                 break;
1283         case cpu_to_le16(0):
1284                 if (sdata->vif.type != NL80211_IFTYPE_ADHOC)
1285                         return -1;
1286                 break;
1287         }
1288
1289         if (unlikely(skb->len - hdrlen < 8))
1290                 return -1;
1291
1292         payload = skb->data + hdrlen;
1293         ethertype = (payload[6] << 8) | payload[7];
1294
1295         if (likely((compare_ether_addr(payload, rfc1042_header) == 0 &&
1296                     ethertype != ETH_P_AARP && ethertype != ETH_P_IPX) ||
1297                    compare_ether_addr(payload, bridge_tunnel_header) == 0)) {
1298                 /* remove RFC1042 or Bridge-Tunnel encapsulation and
1299                  * replace EtherType */
1300                 skb_pull(skb, hdrlen + 6);
1301                 memcpy(skb_push(skb, ETH_ALEN), src, ETH_ALEN);
1302                 memcpy(skb_push(skb, ETH_ALEN), dst, ETH_ALEN);
1303         } else {
1304                 struct ethhdr *ehdr;
1305                 __be16 len;
1306
1307                 skb_pull(skb, hdrlen);
1308                 len = htons(skb->len);
1309                 ehdr = (struct ethhdr *) skb_push(skb, sizeof(struct ethhdr));
1310                 memcpy(ehdr->h_dest, dst, ETH_ALEN);
1311                 memcpy(ehdr->h_source, src, ETH_ALEN);
1312                 ehdr->h_proto = len;
1313         }
1314         return 0;
1315 }
1316
1317 /*
1318  * requires that rx->skb is a frame with ethernet header
1319  */
1320 static bool ieee80211_frame_allowed(struct ieee80211_rx_data *rx, __le16 fc)
1321 {
1322         static const u8 pae_group_addr[ETH_ALEN] __aligned(2)
1323                 = { 0x01, 0x80, 0xC2, 0x00, 0x00, 0x03 };
1324         struct ethhdr *ehdr = (struct ethhdr *) rx->skb->data;
1325
1326         /*
1327          * Allow EAPOL frames to us/the PAE group address regardless
1328          * of whether the frame was encrypted or not.
1329          */
1330         if (ehdr->h_proto == htons(ETH_P_PAE) &&
1331             (compare_ether_addr(ehdr->h_dest, rx->dev->dev_addr) == 0 ||
1332              compare_ether_addr(ehdr->h_dest, pae_group_addr) == 0))
1333                 return true;
1334
1335         if (ieee80211_802_1x_port_control(rx) ||
1336             ieee80211_drop_unencrypted(rx, fc))
1337                 return false;
1338
1339         return true;
1340 }
1341
1342 /*
1343  * requires that rx->skb is a frame with ethernet header
1344  */
1345 static void
1346 ieee80211_deliver_skb(struct ieee80211_rx_data *rx)
1347 {
1348         struct net_device *dev = rx->dev;
1349         struct ieee80211_local *local = rx->local;
1350         struct sk_buff *skb, *xmit_skb;
1351         struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
1352         struct ethhdr *ehdr = (struct ethhdr *) rx->skb->data;
1353         struct sta_info *dsta;
1354
1355         skb = rx->skb;
1356         xmit_skb = NULL;
1357
1358         if ((sdata->vif.type == NL80211_IFTYPE_AP ||
1359              sdata->vif.type == NL80211_IFTYPE_AP_VLAN) &&
1360             !(sdata->flags & IEEE80211_SDATA_DONT_BRIDGE_PACKETS) &&
1361             (rx->flags & IEEE80211_RX_RA_MATCH)) {
1362                 if (is_multicast_ether_addr(ehdr->h_dest)) {
1363                         /*
1364                          * send multicast frames both to higher layers in
1365                          * local net stack and back to the wireless medium
1366                          */
1367                         xmit_skb = skb_copy(skb, GFP_ATOMIC);
1368                         if (!xmit_skb && net_ratelimit())
1369                                 printk(KERN_DEBUG "%s: failed to clone "
1370                                        "multicast frame\n", dev->name);
1371                 } else {
1372                         dsta = sta_info_get(local, skb->data);
1373                         if (dsta && dsta->sdata->dev == dev) {
1374                                 /*
1375                                  * The destination station is associated to
1376                                  * this AP (in this VLAN), so send the frame
1377                                  * directly to it and do not pass it to local
1378                                  * net stack.
1379                                  */
1380                                 xmit_skb = skb;
1381                                 skb = NULL;
1382                         }
1383                 }
1384         }
1385
1386         if (skb) {
1387                 int align __maybe_unused;
1388
1389 #if defined(CONFIG_MAC80211_DEBUG_PACKET_ALIGNMENT) || !defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS)
1390                 /*
1391                  * 'align' will only take the values 0 or 2 here
1392                  * since all frames are required to be aligned
1393                  * to 2-byte boundaries when being passed to
1394                  * mac80211. That also explains the __skb_push()
1395                  * below.
1396                  */
1397                 align = (unsigned long)skb->data & 3;
1398                 if (align) {
1399                         if (WARN_ON(skb_headroom(skb) < 3)) {
1400                                 dev_kfree_skb(skb);
1401                                 skb = NULL;
1402                         } else {
1403                                 u8 *data = skb->data;
1404                                 size_t len = skb->len;
1405                                 u8 *new = __skb_push(skb, align);
1406                                 memmove(new, data, len);
1407                                 __skb_trim(skb, len);
1408                         }
1409                 }
1410 #endif
1411
1412                 if (skb) {
1413                         /* deliver to local stack */
1414                         skb->protocol = eth_type_trans(skb, dev);
1415                         memset(skb->cb, 0, sizeof(skb->cb));
1416                         netif_rx(skb);
1417                 }
1418         }
1419
1420         if (xmit_skb) {
1421                 /* send to wireless media */
1422                 xmit_skb->protocol = htons(ETH_P_802_3);
1423                 skb_reset_network_header(xmit_skb);
1424                 skb_reset_mac_header(xmit_skb);
1425                 dev_queue_xmit(xmit_skb);
1426         }
1427 }
1428
1429 static ieee80211_rx_result debug_noinline
1430 ieee80211_rx_h_amsdu(struct ieee80211_rx_data *rx)
1431 {
1432         struct net_device *dev = rx->dev;
1433         struct ieee80211_local *local = rx->local;
1434         u16 ethertype;
1435         u8 *payload;
1436         struct sk_buff *skb = rx->skb, *frame = NULL;
1437         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
1438         __le16 fc = hdr->frame_control;
1439         const struct ethhdr *eth;
1440         int remaining, err;
1441         u8 dst[ETH_ALEN];
1442         u8 src[ETH_ALEN];
1443
1444         if (unlikely(!ieee80211_is_data(fc)))
1445                 return RX_CONTINUE;
1446
1447         if (unlikely(!ieee80211_is_data_present(fc)))
1448                 return RX_DROP_MONITOR;
1449
1450         if (!(rx->flags & IEEE80211_RX_AMSDU))
1451                 return RX_CONTINUE;
1452
1453         err = ieee80211_data_to_8023(rx);
1454         if (unlikely(err))
1455                 return RX_DROP_UNUSABLE;
1456
1457         skb->dev = dev;
1458
1459         dev->stats.rx_packets++;
1460         dev->stats.rx_bytes += skb->len;
1461
1462         /* skip the wrapping header */
1463         eth = (struct ethhdr *) skb_pull(skb, sizeof(struct ethhdr));
1464         if (!eth)
1465                 return RX_DROP_UNUSABLE;
1466
1467         while (skb != frame) {
1468                 u8 padding;
1469                 __be16 len = eth->h_proto;
1470                 unsigned int subframe_len = sizeof(struct ethhdr) + ntohs(len);
1471
1472                 remaining = skb->len;
1473                 memcpy(dst, eth->h_dest, ETH_ALEN);
1474                 memcpy(src, eth->h_source, ETH_ALEN);
1475
1476                 padding = ((4 - subframe_len) & 0x3);
1477                 /* the last MSDU has no padding */
1478                 if (subframe_len > remaining)
1479                         return RX_DROP_UNUSABLE;
1480
1481                 skb_pull(skb, sizeof(struct ethhdr));
1482                 /* if last subframe reuse skb */
1483                 if (remaining <= subframe_len + padding)
1484                         frame = skb;
1485                 else {
1486                         /*
1487                          * Allocate and reserve two bytes more for payload
1488                          * alignment since sizeof(struct ethhdr) is 14.
1489                          */
1490                         frame = dev_alloc_skb(
1491                                 ALIGN(local->hw.extra_tx_headroom, 4) +
1492                                 subframe_len + 2);
1493
1494                         if (frame == NULL)
1495                                 return RX_DROP_UNUSABLE;
1496
1497                         skb_reserve(frame,
1498                                     ALIGN(local->hw.extra_tx_headroom, 4) +
1499                                     sizeof(struct ethhdr) + 2);
1500                         memcpy(skb_put(frame, ntohs(len)), skb->data,
1501                                 ntohs(len));
1502
1503                         eth = (struct ethhdr *) skb_pull(skb, ntohs(len) +
1504                                                         padding);
1505                         if (!eth) {
1506                                 dev_kfree_skb(frame);
1507                                 return RX_DROP_UNUSABLE;
1508                         }
1509                 }
1510
1511                 skb_reset_network_header(frame);
1512                 frame->dev = dev;
1513                 frame->priority = skb->priority;
1514                 rx->skb = frame;
1515
1516                 payload = frame->data;
1517                 ethertype = (payload[6] << 8) | payload[7];
1518
1519                 if (likely((compare_ether_addr(payload, rfc1042_header) == 0 &&
1520                             ethertype != ETH_P_AARP && ethertype != ETH_P_IPX) ||
1521                            compare_ether_addr(payload,
1522                                               bridge_tunnel_header) == 0)) {
1523                         /* remove RFC1042 or Bridge-Tunnel
1524                          * encapsulation and replace EtherType */
1525                         skb_pull(frame, 6);
1526                         memcpy(skb_push(frame, ETH_ALEN), src, ETH_ALEN);
1527                         memcpy(skb_push(frame, ETH_ALEN), dst, ETH_ALEN);
1528                 } else {
1529                         memcpy(skb_push(frame, sizeof(__be16)),
1530                                &len, sizeof(__be16));
1531                         memcpy(skb_push(frame, ETH_ALEN), src, ETH_ALEN);
1532                         memcpy(skb_push(frame, ETH_ALEN), dst, ETH_ALEN);
1533                 }
1534
1535                 if (!ieee80211_frame_allowed(rx, fc)) {
1536                         if (skb == frame) /* last frame */
1537                                 return RX_DROP_UNUSABLE;
1538                         dev_kfree_skb(frame);
1539                         continue;
1540                 }
1541
1542                 ieee80211_deliver_skb(rx);
1543         }
1544
1545         return RX_QUEUED;
1546 }
1547
1548 #ifdef CONFIG_MAC80211_MESH
1549 static ieee80211_rx_result
1550 ieee80211_rx_h_mesh_fwding(struct ieee80211_rx_data *rx)
1551 {
1552         struct ieee80211_hdr *hdr;
1553         struct ieee80211s_hdr *mesh_hdr;
1554         unsigned int hdrlen;
1555         struct sk_buff *skb = rx->skb, *fwd_skb;
1556
1557         hdr = (struct ieee80211_hdr *) skb->data;
1558         hdrlen = ieee80211_hdrlen(hdr->frame_control);
1559         mesh_hdr = (struct ieee80211s_hdr *) (skb->data + hdrlen);
1560
1561         if (!ieee80211_is_data(hdr->frame_control))
1562                 return RX_CONTINUE;
1563
1564         if (!mesh_hdr->ttl)
1565                 /* illegal frame */
1566                 return RX_DROP_MONITOR;
1567
1568         if (mesh_hdr->flags & MESH_FLAGS_AE_A5_A6){
1569                 struct ieee80211_sub_if_data *sdata;
1570                 struct mesh_path *mppath;
1571
1572                 sdata = IEEE80211_DEV_TO_SUB_IF(rx->dev);
1573                 rcu_read_lock();
1574                 mppath = mpp_path_lookup(mesh_hdr->eaddr2, sdata);
1575                 if (!mppath) {
1576                         mpp_path_add(mesh_hdr->eaddr2, hdr->addr4, sdata);
1577                 } else {
1578                         spin_lock_bh(&mppath->state_lock);
1579                         mppath->exp_time = jiffies;
1580                         if (compare_ether_addr(mppath->mpp, hdr->addr4) != 0)
1581                                 memcpy(mppath->mpp, hdr->addr4, ETH_ALEN);
1582                         spin_unlock_bh(&mppath->state_lock);
1583                 }
1584                 rcu_read_unlock();
1585         }
1586
1587         if (compare_ether_addr(rx->dev->dev_addr, hdr->addr3) == 0)
1588                 return RX_CONTINUE;
1589
1590         mesh_hdr->ttl--;
1591
1592         if (rx->flags & IEEE80211_RX_RA_MATCH) {
1593                 if (!mesh_hdr->ttl)
1594                         IEEE80211_IFSTA_MESH_CTR_INC(&rx->sdata->u.mesh,
1595                                                      dropped_frames_ttl);
1596                 else {
1597                         struct ieee80211_hdr *fwd_hdr;
1598                         fwd_skb = skb_copy(skb, GFP_ATOMIC);
1599
1600                         if (!fwd_skb && net_ratelimit())
1601                                 printk(KERN_DEBUG "%s: failed to clone mesh frame\n",
1602                                                    rx->dev->name);
1603
1604                         fwd_hdr =  (struct ieee80211_hdr *) fwd_skb->data;
1605                         /*
1606                          * Save TA to addr1 to send TA a path error if a
1607                          * suitable next hop is not found
1608                          */
1609                         memcpy(fwd_hdr->addr1, fwd_hdr->addr2, ETH_ALEN);
1610                         memcpy(fwd_hdr->addr2, rx->dev->dev_addr, ETH_ALEN);
1611                         fwd_skb->dev = rx->local->mdev;
1612                         fwd_skb->iif = rx->dev->ifindex;
1613                         dev_queue_xmit(fwd_skb);
1614                 }
1615         }
1616
1617         if (is_multicast_ether_addr(hdr->addr3) ||
1618             rx->dev->flags & IFF_PROMISC)
1619                 return RX_CONTINUE;
1620         else
1621                 return RX_DROP_MONITOR;
1622 }
1623 #endif
1624
1625 static ieee80211_rx_result debug_noinline
1626 ieee80211_rx_h_data(struct ieee80211_rx_data *rx)
1627 {
1628         struct net_device *dev = rx->dev;
1629         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
1630         __le16 fc = hdr->frame_control;
1631         int err;
1632
1633         if (unlikely(!ieee80211_is_data(hdr->frame_control)))
1634                 return RX_CONTINUE;
1635
1636         if (unlikely(!ieee80211_is_data_present(hdr->frame_control)))
1637                 return RX_DROP_MONITOR;
1638
1639         err = ieee80211_data_to_8023(rx);
1640         if (unlikely(err))
1641                 return RX_DROP_UNUSABLE;
1642
1643         if (!ieee80211_frame_allowed(rx, fc))
1644                 return RX_DROP_MONITOR;
1645
1646         rx->skb->dev = dev;
1647
1648         dev->stats.rx_packets++;
1649         dev->stats.rx_bytes += rx->skb->len;
1650
1651         ieee80211_deliver_skb(rx);
1652
1653         return RX_QUEUED;
1654 }
1655
1656 static ieee80211_rx_result debug_noinline
1657 ieee80211_rx_h_ctrl(struct ieee80211_rx_data *rx)
1658 {
1659         struct ieee80211_local *local = rx->local;
1660         struct ieee80211_hw *hw = &local->hw;
1661         struct sk_buff *skb = rx->skb;
1662         struct ieee80211_bar *bar = (struct ieee80211_bar *)skb->data;
1663         struct tid_ampdu_rx *tid_agg_rx;
1664         u16 start_seq_num;
1665         u16 tid;
1666
1667         if (likely(!ieee80211_is_ctl(bar->frame_control)))
1668                 return RX_CONTINUE;
1669
1670         if (ieee80211_is_back_req(bar->frame_control)) {
1671                 if (!rx->sta)
1672                         return RX_CONTINUE;
1673                 tid = le16_to_cpu(bar->control) >> 12;
1674                 if (rx->sta->ampdu_mlme.tid_state_rx[tid]
1675                                         != HT_AGG_STATE_OPERATIONAL)
1676                         return RX_CONTINUE;
1677                 tid_agg_rx = rx->sta->ampdu_mlme.tid_rx[tid];
1678
1679                 start_seq_num = le16_to_cpu(bar->start_seq_num) >> 4;
1680
1681                 /* reset session timer */
1682                 if (tid_agg_rx->timeout)
1683                         mod_timer(&tid_agg_rx->session_timer,
1684                                   TU_TO_EXP_TIME(tid_agg_rx->timeout));
1685
1686                 /* manage reordering buffer according to requested */
1687                 /* sequence number */
1688                 rcu_read_lock();
1689                 ieee80211_sta_manage_reorder_buf(hw, tid_agg_rx, NULL, NULL,
1690                                                  start_seq_num, 1);
1691                 rcu_read_unlock();
1692                 return RX_DROP_UNUSABLE;
1693         }
1694
1695         return RX_CONTINUE;
1696 }
1697
1698 static void ieee80211_process_sa_query_req(struct ieee80211_sub_if_data *sdata,
1699                                            struct ieee80211_mgmt *mgmt,
1700                                            size_t len)
1701 {
1702         struct ieee80211_local *local = sdata->local;
1703         struct sk_buff *skb;
1704         struct ieee80211_mgmt *resp;
1705
1706         if (compare_ether_addr(mgmt->da, sdata->dev->dev_addr) != 0) {
1707                 /* Not to own unicast address */
1708                 return;
1709         }
1710
1711         if (compare_ether_addr(mgmt->sa, sdata->u.mgd.bssid) != 0 ||
1712             compare_ether_addr(mgmt->bssid, sdata->u.mgd.bssid) != 0) {
1713                 /* Not from the current AP. */
1714                 return;
1715         }
1716
1717         if (sdata->u.mgd.state == IEEE80211_STA_MLME_ASSOCIATE) {
1718                 /* Association in progress; ignore SA Query */
1719                 return;
1720         }
1721
1722         if (len < 24 + 1 + sizeof(resp->u.action.u.sa_query)) {
1723                 /* Too short SA Query request frame */
1724                 return;
1725         }
1726
1727         skb = dev_alloc_skb(sizeof(*resp) + local->hw.extra_tx_headroom);
1728         if (skb == NULL)
1729                 return;
1730
1731         skb_reserve(skb, local->hw.extra_tx_headroom);
1732         resp = (struct ieee80211_mgmt *) skb_put(skb, 24);
1733         memset(resp, 0, 24);
1734         memcpy(resp->da, mgmt->sa, ETH_ALEN);
1735         memcpy(resp->sa, sdata->dev->dev_addr, ETH_ALEN);
1736         memcpy(resp->bssid, sdata->u.mgd.bssid, ETH_ALEN);
1737         resp->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
1738                                           IEEE80211_STYPE_ACTION);
1739         skb_put(skb, 1 + sizeof(resp->u.action.u.sa_query));
1740         resp->u.action.category = WLAN_CATEGORY_SA_QUERY;
1741         resp->u.action.u.sa_query.action = WLAN_ACTION_SA_QUERY_RESPONSE;
1742         memcpy(resp->u.action.u.sa_query.trans_id,
1743                mgmt->u.action.u.sa_query.trans_id,
1744                WLAN_SA_QUERY_TR_ID_LEN);
1745
1746         ieee80211_tx_skb(sdata, skb, 1);
1747 }
1748
1749 static ieee80211_rx_result debug_noinline
1750 ieee80211_rx_h_action(struct ieee80211_rx_data *rx)
1751 {
1752         struct ieee80211_local *local = rx->local;
1753         struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(rx->dev);
1754         struct ieee80211_mgmt *mgmt = (struct ieee80211_mgmt *) rx->skb->data;
1755         struct ieee80211_bss *bss;
1756         int len = rx->skb->len;
1757
1758         if (!ieee80211_is_action(mgmt->frame_control))
1759                 return RX_CONTINUE;
1760
1761         if (!rx->sta)
1762                 return RX_DROP_MONITOR;
1763
1764         if (!(rx->flags & IEEE80211_RX_RA_MATCH))
1765                 return RX_DROP_MONITOR;
1766
1767         if (ieee80211_drop_unencrypted(rx, mgmt->frame_control))
1768                 return RX_DROP_MONITOR;
1769
1770         /* all categories we currently handle have action_code */
1771         if (len < IEEE80211_MIN_ACTION_SIZE + 1)
1772                 return RX_DROP_MONITOR;
1773
1774         switch (mgmt->u.action.category) {
1775         case WLAN_CATEGORY_BACK:
1776                 /*
1777                  * The aggregation code is not prepared to handle
1778                  * anything but STA/AP due to the BSSID handling;
1779                  * IBSS could work in the code but isn't supported
1780                  * by drivers or the standard.
1781                  */
1782                 if (sdata->vif.type != NL80211_IFTYPE_STATION &&
1783                     sdata->vif.type != NL80211_IFTYPE_AP_VLAN &&
1784                     sdata->vif.type != NL80211_IFTYPE_AP)
1785                         return RX_DROP_MONITOR;
1786
1787                 switch (mgmt->u.action.u.addba_req.action_code) {
1788                 case WLAN_ACTION_ADDBA_REQ:
1789                         if (len < (IEEE80211_MIN_ACTION_SIZE +
1790                                    sizeof(mgmt->u.action.u.addba_req)))
1791                                 return RX_DROP_MONITOR;
1792                         ieee80211_process_addba_request(local, rx->sta, mgmt, len);
1793                         break;
1794                 case WLAN_ACTION_ADDBA_RESP:
1795                         if (len < (IEEE80211_MIN_ACTION_SIZE +
1796                                    sizeof(mgmt->u.action.u.addba_resp)))
1797                                 return RX_DROP_MONITOR;
1798                         ieee80211_process_addba_resp(local, rx->sta, mgmt, len);
1799                         break;
1800                 case WLAN_ACTION_DELBA:
1801                         if (len < (IEEE80211_MIN_ACTION_SIZE +
1802                                    sizeof(mgmt->u.action.u.delba)))
1803                                 return RX_DROP_MONITOR;
1804                         ieee80211_process_delba(sdata, rx->sta, mgmt, len);
1805                         break;
1806                 }
1807                 break;
1808         case WLAN_CATEGORY_SPECTRUM_MGMT:
1809                 if (local->hw.conf.channel->band != IEEE80211_BAND_5GHZ)
1810                         return RX_DROP_MONITOR;
1811
1812                 if (sdata->vif.type != NL80211_IFTYPE_STATION)
1813                         return RX_DROP_MONITOR;
1814
1815                 switch (mgmt->u.action.u.measurement.action_code) {
1816                 case WLAN_ACTION_SPCT_MSR_REQ:
1817                         if (len < (IEEE80211_MIN_ACTION_SIZE +
1818                                    sizeof(mgmt->u.action.u.measurement)))
1819                                 return RX_DROP_MONITOR;
1820                         ieee80211_process_measurement_req(sdata, mgmt, len);
1821                         break;
1822                 case WLAN_ACTION_SPCT_CHL_SWITCH:
1823                         if (len < (IEEE80211_MIN_ACTION_SIZE +
1824                                    sizeof(mgmt->u.action.u.chan_switch)))
1825                                 return RX_DROP_MONITOR;
1826
1827                         if (memcmp(mgmt->bssid, sdata->u.mgd.bssid, ETH_ALEN))
1828                                 return RX_DROP_MONITOR;
1829
1830                         bss = ieee80211_rx_bss_get(local, sdata->u.mgd.bssid,
1831                                            local->hw.conf.channel->center_freq,
1832                                            sdata->u.mgd.ssid,
1833                                            sdata->u.mgd.ssid_len);
1834                         if (!bss)
1835                                 return RX_DROP_MONITOR;
1836
1837                         ieee80211_process_chanswitch(sdata,
1838                                      &mgmt->u.action.u.chan_switch.sw_elem, bss);
1839                         ieee80211_rx_bss_put(local, bss);
1840                         break;
1841                 }
1842                 break;
1843         case WLAN_CATEGORY_SA_QUERY:
1844                 if (len < (IEEE80211_MIN_ACTION_SIZE +
1845                            sizeof(mgmt->u.action.u.sa_query)))
1846                         return RX_DROP_MONITOR;
1847                 switch (mgmt->u.action.u.sa_query.action) {
1848                 case WLAN_ACTION_SA_QUERY_REQUEST:
1849                         if (sdata->vif.type != NL80211_IFTYPE_STATION)
1850                                 return RX_DROP_MONITOR;
1851                         ieee80211_process_sa_query_req(sdata, mgmt, len);
1852                         break;
1853                 case WLAN_ACTION_SA_QUERY_RESPONSE:
1854                         /*
1855                          * SA Query response is currently only used in AP mode
1856                          * and it is processed in user space.
1857                          */
1858                         return RX_CONTINUE;
1859                 }
1860                 break;
1861         default:
1862                 return RX_CONTINUE;
1863         }
1864
1865         rx->sta->rx_packets++;
1866         dev_kfree_skb(rx->skb);
1867         return RX_QUEUED;
1868 }
1869
1870 static ieee80211_rx_result debug_noinline
1871 ieee80211_rx_h_mgmt(struct ieee80211_rx_data *rx)
1872 {
1873         struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(rx->dev);
1874         struct ieee80211_mgmt *mgmt = (struct ieee80211_mgmt *) rx->skb->data;
1875
1876         if (!(rx->flags & IEEE80211_RX_RA_MATCH))
1877                 return RX_DROP_MONITOR;
1878
1879         if (ieee80211_drop_unencrypted(rx, mgmt->frame_control))
1880                 return RX_DROP_MONITOR;
1881
1882         if (ieee80211_vif_is_mesh(&sdata->vif))
1883                 return ieee80211_mesh_rx_mgmt(sdata, rx->skb, rx->status);
1884
1885         if (sdata->vif.type == NL80211_IFTYPE_ADHOC)
1886                 return ieee80211_ibss_rx_mgmt(sdata, rx->skb, rx->status);
1887
1888         if (sdata->vif.type == NL80211_IFTYPE_STATION)
1889                 return ieee80211_sta_rx_mgmt(sdata, rx->skb, rx->status);
1890
1891         return RX_DROP_MONITOR;
1892 }
1893
1894 static void ieee80211_rx_michael_mic_report(struct net_device *dev,
1895                                             struct ieee80211_hdr *hdr,
1896                                             struct ieee80211_rx_data *rx)
1897 {
1898         int keyidx;
1899         unsigned int hdrlen;
1900
1901         hdrlen = ieee80211_hdrlen(hdr->frame_control);
1902         if (rx->skb->len >= hdrlen + 4)
1903                 keyidx = rx->skb->data[hdrlen + 3] >> 6;
1904         else
1905                 keyidx = -1;
1906
1907         if (!rx->sta) {
1908                 /*
1909                  * Some hardware seem to generate incorrect Michael MIC
1910                  * reports; ignore them to avoid triggering countermeasures.
1911                  */
1912                 goto ignore;
1913         }
1914
1915         if (!ieee80211_has_protected(hdr->frame_control))
1916                 goto ignore;
1917
1918         if (rx->sdata->vif.type == NL80211_IFTYPE_AP && keyidx) {
1919                 /*
1920                  * APs with pairwise keys should never receive Michael MIC
1921                  * errors for non-zero keyidx because these are reserved for
1922                  * group keys and only the AP is sending real multicast
1923                  * frames in the BSS.
1924                  */
1925                 goto ignore;
1926         }
1927
1928         if (!ieee80211_is_data(hdr->frame_control) &&
1929             !ieee80211_is_auth(hdr->frame_control))
1930                 goto ignore;
1931
1932         mac80211_ev_michael_mic_failure(rx->sdata, keyidx, hdr, NULL);
1933  ignore:
1934         dev_kfree_skb(rx->skb);
1935         rx->skb = NULL;
1936 }
1937
1938 /* TODO: use IEEE80211_RX_FRAGMENTED */
1939 static void ieee80211_rx_cooked_monitor(struct ieee80211_rx_data *rx)
1940 {
1941         struct ieee80211_sub_if_data *sdata;
1942         struct ieee80211_local *local = rx->local;
1943         struct ieee80211_rtap_hdr {
1944                 struct ieee80211_radiotap_header hdr;
1945                 u8 flags;
1946                 u8 rate;
1947                 __le16 chan_freq;
1948                 __le16 chan_flags;
1949         } __attribute__ ((packed)) *rthdr;
1950         struct sk_buff *skb = rx->skb, *skb2;
1951         struct net_device *prev_dev = NULL;
1952         struct ieee80211_rx_status *status = rx->status;
1953
1954         if (rx->flags & IEEE80211_RX_CMNTR_REPORTED)
1955                 goto out_free_skb;
1956
1957         if (skb_headroom(skb) < sizeof(*rthdr) &&
1958             pskb_expand_head(skb, sizeof(*rthdr), 0, GFP_ATOMIC))
1959                 goto out_free_skb;
1960
1961         rthdr = (void *)skb_push(skb, sizeof(*rthdr));
1962         memset(rthdr, 0, sizeof(*rthdr));
1963         rthdr->hdr.it_len = cpu_to_le16(sizeof(*rthdr));
1964         rthdr->hdr.it_present =
1965                 cpu_to_le32((1 << IEEE80211_RADIOTAP_FLAGS) |
1966                             (1 << IEEE80211_RADIOTAP_RATE) |
1967                             (1 << IEEE80211_RADIOTAP_CHANNEL));
1968
1969         rthdr->rate = rx->rate->bitrate / 5;
1970         rthdr->chan_freq = cpu_to_le16(status->freq);
1971
1972         if (status->band == IEEE80211_BAND_5GHZ)
1973                 rthdr->chan_flags = cpu_to_le16(IEEE80211_CHAN_OFDM |
1974                                                 IEEE80211_CHAN_5GHZ);
1975         else
1976                 rthdr->chan_flags = cpu_to_le16(IEEE80211_CHAN_DYN |
1977                                                 IEEE80211_CHAN_2GHZ);
1978
1979         skb_set_mac_header(skb, 0);
1980         skb->ip_summed = CHECKSUM_UNNECESSARY;
1981         skb->pkt_type = PACKET_OTHERHOST;
1982         skb->protocol = htons(ETH_P_802_2);
1983
1984         list_for_each_entry_rcu(sdata, &local->interfaces, list) {
1985                 if (!netif_running(sdata->dev))
1986                         continue;
1987
1988                 if (sdata->vif.type != NL80211_IFTYPE_MONITOR ||
1989                     !(sdata->u.mntr_flags & MONITOR_FLAG_COOK_FRAMES))
1990                         continue;
1991
1992                 if (prev_dev) {
1993                         skb2 = skb_clone(skb, GFP_ATOMIC);
1994                         if (skb2) {
1995                                 skb2->dev = prev_dev;
1996                                 netif_rx(skb2);
1997                         }
1998                 }
1999
2000                 prev_dev = sdata->dev;
2001                 sdata->dev->stats.rx_packets++;
2002                 sdata->dev->stats.rx_bytes += skb->len;
2003         }
2004
2005         if (prev_dev) {
2006                 skb->dev = prev_dev;
2007                 netif_rx(skb);
2008                 skb = NULL;
2009         } else
2010                 goto out_free_skb;
2011
2012         rx->flags |= IEEE80211_RX_CMNTR_REPORTED;
2013         return;
2014
2015  out_free_skb:
2016         dev_kfree_skb(skb);
2017 }
2018
2019
2020 static void ieee80211_invoke_rx_handlers(struct ieee80211_sub_if_data *sdata,
2021                                          struct ieee80211_rx_data *rx,
2022                                          struct sk_buff *skb)
2023 {
2024         ieee80211_rx_result res = RX_DROP_MONITOR;
2025
2026         rx->skb = skb;
2027         rx->sdata = sdata;
2028         rx->dev = sdata->dev;
2029
2030 #define CALL_RXH(rxh)                   \
2031         do {                            \
2032                 res = rxh(rx);          \
2033                 if (res != RX_CONTINUE) \
2034                         goto rxh_done;  \
2035         } while (0);
2036
2037         CALL_RXH(ieee80211_rx_h_passive_scan)
2038         CALL_RXH(ieee80211_rx_h_check)
2039         CALL_RXH(ieee80211_rx_h_decrypt)
2040         CALL_RXH(ieee80211_rx_h_check_more_data)
2041         CALL_RXH(ieee80211_rx_h_sta_process)
2042         CALL_RXH(ieee80211_rx_h_defragment)
2043         CALL_RXH(ieee80211_rx_h_ps_poll)
2044         CALL_RXH(ieee80211_rx_h_michael_mic_verify)
2045         /* must be after MMIC verify so header is counted in MPDU mic */
2046         CALL_RXH(ieee80211_rx_h_remove_qos_control)
2047         CALL_RXH(ieee80211_rx_h_amsdu)
2048 #ifdef CONFIG_MAC80211_MESH
2049         if (ieee80211_vif_is_mesh(&sdata->vif))
2050                 CALL_RXH(ieee80211_rx_h_mesh_fwding);
2051 #endif
2052         CALL_RXH(ieee80211_rx_h_data)
2053         CALL_RXH(ieee80211_rx_h_ctrl)
2054         CALL_RXH(ieee80211_rx_h_action)
2055         CALL_RXH(ieee80211_rx_h_mgmt)
2056
2057 #undef CALL_RXH
2058
2059  rxh_done:
2060         switch (res) {
2061         case RX_DROP_MONITOR:
2062                 I802_DEBUG_INC(sdata->local->rx_handlers_drop);
2063                 if (rx->sta)
2064                         rx->sta->rx_dropped++;
2065                 /* fall through */
2066         case RX_CONTINUE:
2067                 ieee80211_rx_cooked_monitor(rx);
2068                 break;
2069         case RX_DROP_UNUSABLE:
2070                 I802_DEBUG_INC(sdata->local->rx_handlers_drop);
2071                 if (rx->sta)
2072                         rx->sta->rx_dropped++;
2073                 dev_kfree_skb(rx->skb);
2074                 break;
2075         case RX_QUEUED:
2076                 I802_DEBUG_INC(sdata->local->rx_handlers_queued);
2077                 break;
2078         }
2079 }
2080
2081 /* main receive path */
2082
2083 static int prepare_for_handlers(struct ieee80211_sub_if_data *sdata,
2084                                 struct ieee80211_rx_data *rx,
2085                                 struct ieee80211_hdr *hdr)
2086 {
2087         u8 *bssid = ieee80211_get_bssid(hdr, rx->skb->len, sdata->vif.type);
2088         int multicast = is_multicast_ether_addr(hdr->addr1);
2089
2090         switch (sdata->vif.type) {
2091         case NL80211_IFTYPE_STATION:
2092                 if (!bssid)
2093                         return 0;
2094                 if (!ieee80211_bssid_match(bssid, sdata->u.mgd.bssid)) {
2095                         if (!(rx->flags & IEEE80211_RX_IN_SCAN))
2096                                 return 0;
2097                         rx->flags &= ~IEEE80211_RX_RA_MATCH;
2098                 } else if (!multicast &&
2099                            compare_ether_addr(sdata->dev->dev_addr,
2100                                               hdr->addr1) != 0) {
2101                         if (!(sdata->dev->flags & IFF_PROMISC))
2102                                 return 0;
2103                         rx->flags &= ~IEEE80211_RX_RA_MATCH;
2104                 }
2105                 break;
2106         case NL80211_IFTYPE_ADHOC:
2107                 if (!bssid)
2108                         return 0;
2109                 if (ieee80211_is_beacon(hdr->frame_control)) {
2110                         return 1;
2111                 }
2112                 else if (!ieee80211_bssid_match(bssid, sdata->u.ibss.bssid)) {
2113                         if (!(rx->flags & IEEE80211_RX_IN_SCAN))
2114                                 return 0;
2115                         rx->flags &= ~IEEE80211_RX_RA_MATCH;
2116                 } else if (!multicast &&
2117                            compare_ether_addr(sdata->dev->dev_addr,
2118                                               hdr->addr1) != 0) {
2119                         if (!(sdata->dev->flags & IFF_PROMISC))
2120                                 return 0;
2121                         rx->flags &= ~IEEE80211_RX_RA_MATCH;
2122                 } else if (!rx->sta) {
2123                         int rate_idx;
2124                         if (rx->status->flag & RX_FLAG_HT)
2125                                 rate_idx = 0; /* TODO: HT rates */
2126                         else
2127                                 rate_idx = rx->status->rate_idx;
2128                         rx->sta = ieee80211_ibss_add_sta(sdata, bssid, hdr->addr2,
2129                                 BIT(rate_idx));
2130                 }
2131                 break;
2132         case NL80211_IFTYPE_MESH_POINT:
2133                 if (!multicast &&
2134                     compare_ether_addr(sdata->dev->dev_addr,
2135                                        hdr->addr1) != 0) {
2136                         if (!(sdata->dev->flags & IFF_PROMISC))
2137                                 return 0;
2138
2139                         rx->flags &= ~IEEE80211_RX_RA_MATCH;
2140                 }
2141                 break;
2142         case NL80211_IFTYPE_AP_VLAN:
2143         case NL80211_IFTYPE_AP:
2144                 if (!bssid) {
2145                         if (compare_ether_addr(sdata->dev->dev_addr,
2146                                                hdr->addr1))
2147                                 return 0;
2148                 } else if (!ieee80211_bssid_match(bssid,
2149                                         sdata->dev->dev_addr)) {
2150                         if (!(rx->flags & IEEE80211_RX_IN_SCAN))
2151                                 return 0;
2152                         rx->flags &= ~IEEE80211_RX_RA_MATCH;
2153                 }
2154                 break;
2155         case NL80211_IFTYPE_WDS:
2156                 if (bssid || !ieee80211_is_data(hdr->frame_control))
2157                         return 0;
2158                 if (compare_ether_addr(sdata->u.wds.remote_addr, hdr->addr2))
2159                         return 0;
2160                 break;
2161         case NL80211_IFTYPE_MONITOR:
2162                 /* take everything */
2163                 break;
2164         case NL80211_IFTYPE_UNSPECIFIED:
2165         case __NL80211_IFTYPE_AFTER_LAST:
2166                 /* should never get here */
2167                 WARN_ON(1);
2168                 break;
2169         }
2170
2171         return 1;
2172 }
2173
2174 /*
2175  * This is the actual Rx frames handler. as it blongs to Rx path it must
2176  * be called with rcu_read_lock protection.
2177  */
2178 static void __ieee80211_rx_handle_packet(struct ieee80211_hw *hw,
2179                                          struct sk_buff *skb,
2180                                          struct ieee80211_rx_status *status,
2181                                          struct ieee80211_rate *rate)
2182 {
2183         struct ieee80211_local *local = hw_to_local(hw);
2184         struct ieee80211_sub_if_data *sdata;
2185         struct ieee80211_hdr *hdr;
2186         struct ieee80211_rx_data rx;
2187         int prepares;
2188         struct ieee80211_sub_if_data *prev = NULL;
2189         struct sk_buff *skb_new;
2190
2191         hdr = (struct ieee80211_hdr *)skb->data;
2192         memset(&rx, 0, sizeof(rx));
2193         rx.skb = skb;
2194         rx.local = local;
2195
2196         rx.status = status;
2197         rx.rate = rate;
2198
2199         if (ieee80211_is_data(hdr->frame_control) || ieee80211_is_mgmt(hdr->frame_control))
2200                 local->dot11ReceivedFragmentCount++;
2201
2202         rx.sta = sta_info_get(local, hdr->addr2);
2203         if (rx.sta) {
2204                 rx.sdata = rx.sta->sdata;
2205                 rx.dev = rx.sta->sdata->dev;
2206         }
2207
2208         if ((status->flag & RX_FLAG_MMIC_ERROR)) {
2209                 ieee80211_rx_michael_mic_report(local->mdev, hdr, &rx);
2210                 return;
2211         }
2212
2213         if (unlikely(local->sw_scanning || local->hw_scanning))
2214                 rx.flags |= IEEE80211_RX_IN_SCAN;
2215
2216         ieee80211_parse_qos(&rx);
2217         ieee80211_verify_alignment(&rx);
2218
2219         skb = rx.skb;
2220
2221         list_for_each_entry_rcu(sdata, &local->interfaces, list) {
2222                 if (!netif_running(sdata->dev))
2223                         continue;
2224
2225                 if (sdata->vif.type == NL80211_IFTYPE_MONITOR)
2226                         continue;
2227
2228                 rx.flags |= IEEE80211_RX_RA_MATCH;
2229                 prepares = prepare_for_handlers(sdata, &rx, hdr);
2230
2231                 if (!prepares)
2232                         continue;
2233
2234                 /*
2235                  * frame is destined for this interface, but if it's not
2236                  * also for the previous one we handle that after the
2237                  * loop to avoid copying the SKB once too much
2238                  */
2239
2240                 if (!prev) {
2241                         prev = sdata;
2242                         continue;
2243                 }
2244
2245                 /*
2246                  * frame was destined for the previous interface
2247                  * so invoke RX handlers for it
2248                  */
2249
2250                 skb_new = skb_copy(skb, GFP_ATOMIC);
2251                 if (!skb_new) {
2252                         if (net_ratelimit())
2253                                 printk(KERN_DEBUG "%s: failed to copy "
2254                                        "multicast frame for %s\n",
2255                                        wiphy_name(local->hw.wiphy),
2256                                        prev->dev->name);
2257                         continue;
2258                 }
2259                 ieee80211_invoke_rx_handlers(prev, &rx, skb_new);
2260                 prev = sdata;
2261         }
2262         if (prev)
2263                 ieee80211_invoke_rx_handlers(prev, &rx, skb);
2264         else
2265                 dev_kfree_skb(skb);
2266 }
2267
2268 #define SEQ_MODULO 0x1000
2269 #define SEQ_MASK   0xfff
2270
2271 static inline int seq_less(u16 sq1, u16 sq2)
2272 {
2273         return ((sq1 - sq2) & SEQ_MASK) > (SEQ_MODULO >> 1);
2274 }
2275
2276 static inline u16 seq_inc(u16 sq)
2277 {
2278         return (sq + 1) & SEQ_MASK;
2279 }
2280
2281 static inline u16 seq_sub(u16 sq1, u16 sq2)
2282 {
2283         return (sq1 - sq2) & SEQ_MASK;
2284 }
2285
2286
2287 static void ieee80211_release_reorder_frame(struct ieee80211_hw *hw,
2288                                             struct tid_ampdu_rx *tid_agg_rx,
2289                                             int index)
2290 {
2291         struct ieee80211_supported_band *sband;
2292         struct ieee80211_rate *rate;
2293         struct ieee80211_rx_status status;
2294
2295         if (!tid_agg_rx->reorder_buf[index])
2296                 goto no_frame;
2297
2298         /* release the reordered frames to stack */
2299         memcpy(&status, tid_agg_rx->reorder_buf[index]->cb, sizeof(status));
2300         sband = hw->wiphy->bands[status.band];
2301         if (status.flag & RX_FLAG_HT)
2302                 rate = sband->bitrates; /* TODO: HT rates */
2303         else
2304                 rate = &sband->bitrates[status.rate_idx];
2305         __ieee80211_rx_handle_packet(hw, tid_agg_rx->reorder_buf[index],
2306                                      &status, rate);
2307         tid_agg_rx->stored_mpdu_num--;
2308         tid_agg_rx->reorder_buf[index] = NULL;
2309
2310 no_frame:
2311         tid_agg_rx->head_seq_num = seq_inc(tid_agg_rx->head_seq_num);
2312 }
2313
2314
2315 /*
2316  * Timeout (in jiffies) for skb's that are waiting in the RX reorder buffer. If
2317  * the skb was added to the buffer longer than this time ago, the earlier
2318  * frames that have not yet been received are assumed to be lost and the skb
2319  * can be released for processing. This may also release other skb's from the
2320  * reorder buffer if there are no additional gaps between the frames.
2321  */
2322 #define HT_RX_REORDER_BUF_TIMEOUT (HZ / 10)
2323
2324 /*
2325  * As it function blongs to Rx path it must be called with
2326  * the proper rcu_read_lock protection for its flow.
2327  */
2328 static u8 ieee80211_sta_manage_reorder_buf(struct ieee80211_hw *hw,
2329                                            struct tid_ampdu_rx *tid_agg_rx,
2330                                            struct sk_buff *skb,
2331                                            struct ieee80211_rx_status *rxstatus,
2332                                            u16 mpdu_seq_num,
2333                                            int bar_req)
2334 {
2335         u16 head_seq_num, buf_size;
2336         int index;
2337
2338         buf_size = tid_agg_rx->buf_size;
2339         head_seq_num = tid_agg_rx->head_seq_num;
2340
2341         /* frame with out of date sequence number */
2342         if (seq_less(mpdu_seq_num, head_seq_num)) {
2343                 dev_kfree_skb(skb);
2344                 return 1;
2345         }
2346
2347         /* if frame sequence number exceeds our buffering window size or
2348          * block Ack Request arrived - release stored frames */
2349         if ((!seq_less(mpdu_seq_num, head_seq_num + buf_size)) || (bar_req)) {
2350                 /* new head to the ordering buffer */
2351                 if (bar_req)
2352                         head_seq_num = mpdu_seq_num;
2353                 else
2354                         head_seq_num =
2355                                 seq_inc(seq_sub(mpdu_seq_num, buf_size));
2356                 /* release stored frames up to new head to stack */
2357                 while (seq_less(tid_agg_rx->head_seq_num, head_seq_num)) {
2358                         index = seq_sub(tid_agg_rx->head_seq_num,
2359                                 tid_agg_rx->ssn)
2360                                 % tid_agg_rx->buf_size;
2361                         ieee80211_release_reorder_frame(hw, tid_agg_rx,
2362                                                         index);
2363                 }
2364                 if (bar_req)
2365                         return 1;
2366         }
2367
2368         /* now the new frame is always in the range of the reordering */
2369         /* buffer window */
2370         index = seq_sub(mpdu_seq_num, tid_agg_rx->ssn)
2371                                 % tid_agg_rx->buf_size;
2372         /* check if we already stored this frame */
2373         if (tid_agg_rx->reorder_buf[index]) {
2374                 dev_kfree_skb(skb);
2375                 return 1;
2376         }
2377
2378         /* if arrived mpdu is in the right order and nothing else stored */
2379         /* release it immediately */
2380         if (mpdu_seq_num == tid_agg_rx->head_seq_num &&
2381                         tid_agg_rx->stored_mpdu_num == 0) {
2382                 tid_agg_rx->head_seq_num =
2383                         seq_inc(tid_agg_rx->head_seq_num);
2384                 return 0;
2385         }
2386
2387         /* put the frame in the reordering buffer */
2388         tid_agg_rx->reorder_buf[index] = skb;
2389         tid_agg_rx->reorder_time[index] = jiffies;
2390         memcpy(tid_agg_rx->reorder_buf[index]->cb, rxstatus,
2391                sizeof(*rxstatus));
2392         tid_agg_rx->stored_mpdu_num++;
2393         /* release the buffer until next missing frame */
2394         index = seq_sub(tid_agg_rx->head_seq_num, tid_agg_rx->ssn)
2395                                                 % tid_agg_rx->buf_size;
2396         if (!tid_agg_rx->reorder_buf[index] &&
2397             tid_agg_rx->stored_mpdu_num > 1) {
2398                 /*
2399                  * No buffers ready to be released, but check whether any
2400                  * frames in the reorder buffer have timed out.
2401                  */
2402                 int j;
2403                 int skipped = 1;
2404                 for (j = (index + 1) % tid_agg_rx->buf_size; j != index;
2405                      j = (j + 1) % tid_agg_rx->buf_size) {
2406                         if (tid_agg_rx->reorder_buf[j] == NULL) {
2407                                 skipped++;
2408                                 continue;
2409                         }
2410                         if (!time_after(jiffies, tid_agg_rx->reorder_time[j] +
2411                                         HZ / 10))
2412                                 break;
2413
2414 #ifdef CONFIG_MAC80211_HT_DEBUG
2415                         if (net_ratelimit())
2416                                 printk(KERN_DEBUG "%s: release an RX reorder "
2417                                        "frame due to timeout on earlier "
2418                                        "frames\n",
2419                                        wiphy_name(hw->wiphy));
2420 #endif
2421                         ieee80211_release_reorder_frame(hw, tid_agg_rx, j);
2422
2423                         /*
2424                          * Increment the head seq# also for the skipped slots.
2425                          */
2426                         tid_agg_rx->head_seq_num =
2427                                 (tid_agg_rx->head_seq_num + skipped) &
2428                                 SEQ_MASK;
2429                         skipped = 0;
2430                 }
2431         } else while (tid_agg_rx->reorder_buf[index]) {
2432                 ieee80211_release_reorder_frame(hw, tid_agg_rx, index);
2433                 index = seq_sub(tid_agg_rx->head_seq_num,
2434                         tid_agg_rx->ssn) % tid_agg_rx->buf_size;
2435         }
2436         return 1;
2437 }
2438
2439 static u8 ieee80211_rx_reorder_ampdu(struct ieee80211_local *local,
2440                                      struct sk_buff *skb,
2441                                      struct ieee80211_rx_status *status)
2442 {
2443         struct ieee80211_hw *hw = &local->hw;
2444         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
2445         struct sta_info *sta;
2446         struct tid_ampdu_rx *tid_agg_rx;
2447         u16 sc;
2448         u16 mpdu_seq_num;
2449         u8 ret = 0;
2450         int tid;
2451
2452         sta = sta_info_get(local, hdr->addr2);
2453         if (!sta)
2454                 return ret;
2455
2456         /* filter the QoS data rx stream according to
2457          * STA/TID and check if this STA/TID is on aggregation */
2458         if (!ieee80211_is_data_qos(hdr->frame_control))
2459                 goto end_reorder;
2460
2461         tid = *ieee80211_get_qos_ctl(hdr) & IEEE80211_QOS_CTL_TID_MASK;
2462
2463         if (sta->ampdu_mlme.tid_state_rx[tid] != HT_AGG_STATE_OPERATIONAL)
2464                 goto end_reorder;
2465
2466         tid_agg_rx = sta->ampdu_mlme.tid_rx[tid];
2467
2468         /* qos null data frames are excluded */
2469         if (unlikely(hdr->frame_control & cpu_to_le16(IEEE80211_STYPE_NULLFUNC)))
2470                 goto end_reorder;
2471
2472         /* new un-ordered ampdu frame - process it */
2473
2474         /* reset session timer */
2475         if (tid_agg_rx->timeout)
2476                 mod_timer(&tid_agg_rx->session_timer,
2477                           TU_TO_EXP_TIME(tid_agg_rx->timeout));
2478
2479         /* if this mpdu is fragmented - terminate rx aggregation session */
2480         sc = le16_to_cpu(hdr->seq_ctrl);
2481         if (sc & IEEE80211_SCTL_FRAG) {
2482                 ieee80211_sta_stop_rx_ba_session(sta->sdata, sta->sta.addr,
2483                         tid, 0, WLAN_REASON_QSTA_REQUIRE_SETUP);
2484                 ret = 1;
2485                 goto end_reorder;
2486         }
2487
2488         /* according to mpdu sequence number deal with reordering buffer */
2489         mpdu_seq_num = (sc & IEEE80211_SCTL_SEQ) >> 4;
2490         ret = ieee80211_sta_manage_reorder_buf(hw, tid_agg_rx, skb, status,
2491                                                 mpdu_seq_num, 0);
2492  end_reorder:
2493         return ret;
2494 }
2495
2496 /*
2497  * This is the receive path handler. It is called by a low level driver when an
2498  * 802.11 MPDU is received from the hardware.
2499  */
2500 void __ieee80211_rx(struct ieee80211_hw *hw, struct sk_buff *skb,
2501                     struct ieee80211_rx_status *status)
2502 {
2503         struct ieee80211_local *local = hw_to_local(hw);
2504         struct ieee80211_rate *rate = NULL;
2505         struct ieee80211_supported_band *sband;
2506
2507         if (status->band < 0 ||
2508             status->band >= IEEE80211_NUM_BANDS) {
2509                 WARN_ON(1);
2510                 return;
2511         }
2512
2513         sband = local->hw.wiphy->bands[status->band];
2514         if (!sband) {
2515                 WARN_ON(1);
2516                 return;
2517         }
2518
2519         if (status->flag & RX_FLAG_HT) {
2520                 /* rate_idx is MCS index */
2521                 if (WARN_ON(status->rate_idx < 0 ||
2522                             status->rate_idx >= 76))
2523                         return;
2524                 /* HT rates are not in the table - use the highest legacy rate
2525                  * for now since other parts of mac80211 may not yet be fully
2526                  * MCS aware. */
2527                 rate = &sband->bitrates[sband->n_bitrates - 1];
2528         } else {
2529                 if (WARN_ON(status->rate_idx < 0 ||
2530                             status->rate_idx >= sband->n_bitrates))
2531                         return;
2532                 rate = &sband->bitrates[status->rate_idx];
2533         }
2534
2535         /*
2536          * key references and virtual interfaces are protected using RCU
2537          * and this requires that we are in a read-side RCU section during
2538          * receive processing
2539          */
2540         rcu_read_lock();
2541
2542         /*
2543          * Frames with failed FCS/PLCP checksum are not returned,
2544          * all other frames are returned without radiotap header
2545          * if it was previously present.
2546          * Also, frames with less than 16 bytes are dropped.
2547          */
2548         skb = ieee80211_rx_monitor(local, skb, status, rate);
2549         if (!skb) {
2550                 rcu_read_unlock();
2551                 return;
2552         }
2553
2554         /*
2555          * In theory, the block ack reordering should happen after duplicate
2556          * removal (ieee80211_rx_h_check(), which is an RX handler). As such,
2557          * the call to ieee80211_rx_reorder_ampdu() should really be moved to
2558          * happen as a new RX handler between ieee80211_rx_h_check and
2559          * ieee80211_rx_h_decrypt. This cleanup may eventually happen, but for
2560          * the time being, the call can be here since RX reorder buf processing
2561          * will implicitly skip duplicates. We could, in theory at least,
2562          * process frames that ieee80211_rx_h_passive_scan would drop (e.g.,
2563          * frames from other than operational channel), but that should not
2564          * happen in normal networks.
2565          */
2566         if (!ieee80211_rx_reorder_ampdu(local, skb, status))
2567                 __ieee80211_rx_handle_packet(hw, skb, status, rate);
2568
2569         rcu_read_unlock();
2570 }
2571 EXPORT_SYMBOL(__ieee80211_rx);
2572
2573 /* This is a version of the rx handler that can be called from hard irq
2574  * context. Post the skb on the queue and schedule the tasklet */
2575 void ieee80211_rx_irqsafe(struct ieee80211_hw *hw, struct sk_buff *skb,
2576                           struct ieee80211_rx_status *status)
2577 {
2578         struct ieee80211_local *local = hw_to_local(hw);
2579
2580         BUILD_BUG_ON(sizeof(struct ieee80211_rx_status) > sizeof(skb->cb));
2581
2582         skb->dev = local->mdev;
2583         /* copy status into skb->cb for use by tasklet */
2584         memcpy(skb->cb, status, sizeof(*status));
2585         skb->pkt_type = IEEE80211_RX_MSG;
2586         skb_queue_tail(&local->skb_queue, skb);
2587         tasklet_schedule(&local->tasklet);
2588 }
2589 EXPORT_SYMBOL(ieee80211_rx_irqsafe);