dccp: Auto-load (when supported) CCID plugins for negotiation
[linux-2.6.git] / net / mac80211 / rx.c
1 /*
2  * Copyright 2002-2005, Instant802 Networks, Inc.
3  * Copyright 2005-2006, Devicescape Software, Inc.
4  * Copyright 2006-2007  Jiri Benc <jbenc@suse.cz>
5  * Copyright 2007       Johannes Berg <johannes@sipsolutions.net>
6  *
7  * This program is free software; you can redistribute it and/or modify
8  * it under the terms of the GNU General Public License version 2 as
9  * published by the Free Software Foundation.
10  */
11
12 #include <linux/jiffies.h>
13 #include <linux/kernel.h>
14 #include <linux/skbuff.h>
15 #include <linux/netdevice.h>
16 #include <linux/etherdevice.h>
17 #include <linux/rcupdate.h>
18 #include <net/mac80211.h>
19 #include <net/ieee80211_radiotap.h>
20
21 #include "ieee80211_i.h"
22 #include "led.h"
23 #include "mesh.h"
24 #include "wep.h"
25 #include "wpa.h"
26 #include "tkip.h"
27 #include "wme.h"
28
29 u8 ieee80211_sta_manage_reorder_buf(struct ieee80211_hw *hw,
30                                 struct tid_ampdu_rx *tid_agg_rx,
31                                 struct sk_buff *skb, u16 mpdu_seq_num,
32                                 int bar_req);
33 /*
34  * monitor mode reception
35  *
36  * This function cleans up the SKB, i.e. it removes all the stuff
37  * only useful for monitoring.
38  */
39 static struct sk_buff *remove_monitor_info(struct ieee80211_local *local,
40                                            struct sk_buff *skb,
41                                            int rtap_len)
42 {
43         skb_pull(skb, rtap_len);
44
45         if (local->hw.flags & IEEE80211_HW_RX_INCLUDES_FCS) {
46                 if (likely(skb->len > FCS_LEN))
47                         skb_trim(skb, skb->len - FCS_LEN);
48                 else {
49                         /* driver bug */
50                         WARN_ON(1);
51                         dev_kfree_skb(skb);
52                         skb = NULL;
53                 }
54         }
55
56         return skb;
57 }
58
59 static inline int should_drop_frame(struct ieee80211_rx_status *status,
60                                     struct sk_buff *skb,
61                                     int present_fcs_len,
62                                     int radiotap_len)
63 {
64         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
65
66         if (status->flag & (RX_FLAG_FAILED_FCS_CRC | RX_FLAG_FAILED_PLCP_CRC))
67                 return 1;
68         if (unlikely(skb->len < 16 + present_fcs_len + radiotap_len))
69                 return 1;
70         if (ieee80211_is_ctl(hdr->frame_control) &&
71             !ieee80211_is_pspoll(hdr->frame_control) &&
72             !ieee80211_is_back_req(hdr->frame_control))
73                 return 1;
74         return 0;
75 }
76
77 static int
78 ieee80211_rx_radiotap_len(struct ieee80211_local *local,
79                           struct ieee80211_rx_status *status)
80 {
81         int len;
82
83         /* always present fields */
84         len = sizeof(struct ieee80211_radiotap_header) + 9;
85
86         if (status->flag & RX_FLAG_TSFT)
87                 len += 8;
88         if (local->hw.flags & IEEE80211_HW_SIGNAL_DB ||
89             local->hw.flags & IEEE80211_HW_SIGNAL_DBM)
90                 len += 1;
91         if (local->hw.flags & IEEE80211_HW_NOISE_DBM)
92                 len += 1;
93
94         if (len & 1) /* padding for RX_FLAGS if necessary */
95                 len++;
96
97         /* make sure radiotap starts at a naturally aligned address */
98         if (len % 8)
99                 len = roundup(len, 8);
100
101         return len;
102 }
103
104 /**
105  * ieee80211_add_rx_radiotap_header - add radiotap header
106  *
107  * add a radiotap header containing all the fields which the hardware provided.
108  */
109 static void
110 ieee80211_add_rx_radiotap_header(struct ieee80211_local *local,
111                                  struct sk_buff *skb,
112                                  struct ieee80211_rx_status *status,
113                                  struct ieee80211_rate *rate,
114                                  int rtap_len)
115 {
116         struct ieee80211_radiotap_header *rthdr;
117         unsigned char *pos;
118
119         rthdr = (struct ieee80211_radiotap_header *)skb_push(skb, rtap_len);
120         memset(rthdr, 0, rtap_len);
121
122         /* radiotap header, set always present flags */
123         rthdr->it_present =
124                 cpu_to_le32((1 << IEEE80211_RADIOTAP_FLAGS) |
125                             (1 << IEEE80211_RADIOTAP_RATE) |
126                             (1 << IEEE80211_RADIOTAP_CHANNEL) |
127                             (1 << IEEE80211_RADIOTAP_ANTENNA) |
128                             (1 << IEEE80211_RADIOTAP_RX_FLAGS));
129         rthdr->it_len = cpu_to_le16(rtap_len);
130
131         pos = (unsigned char *)(rthdr+1);
132
133         /* the order of the following fields is important */
134
135         /* IEEE80211_RADIOTAP_TSFT */
136         if (status->flag & RX_FLAG_TSFT) {
137                 *(__le64 *)pos = cpu_to_le64(status->mactime);
138                 rthdr->it_present |=
139                         cpu_to_le32(1 << IEEE80211_RADIOTAP_TSFT);
140                 pos += 8;
141         }
142
143         /* IEEE80211_RADIOTAP_FLAGS */
144         if (local->hw.flags & IEEE80211_HW_RX_INCLUDES_FCS)
145                 *pos |= IEEE80211_RADIOTAP_F_FCS;
146         pos++;
147
148         /* IEEE80211_RADIOTAP_RATE */
149         *pos = rate->bitrate / 5;
150         pos++;
151
152         /* IEEE80211_RADIOTAP_CHANNEL */
153         *(__le16 *)pos = cpu_to_le16(status->freq);
154         pos += 2;
155         if (status->band == IEEE80211_BAND_5GHZ)
156                 *(__le16 *)pos = cpu_to_le16(IEEE80211_CHAN_OFDM |
157                                              IEEE80211_CHAN_5GHZ);
158         else
159                 *(__le16 *)pos = cpu_to_le16(IEEE80211_CHAN_DYN |
160                                              IEEE80211_CHAN_2GHZ);
161         pos += 2;
162
163         /* IEEE80211_RADIOTAP_DBM_ANTSIGNAL */
164         if (local->hw.flags & IEEE80211_HW_SIGNAL_DBM) {
165                 *pos = status->signal;
166                 rthdr->it_present |=
167                         cpu_to_le32(1 << IEEE80211_RADIOTAP_DBM_ANTSIGNAL);
168                 pos++;
169         }
170
171         /* IEEE80211_RADIOTAP_DBM_ANTNOISE */
172         if (local->hw.flags & IEEE80211_HW_NOISE_DBM) {
173                 *pos = status->noise;
174                 rthdr->it_present |=
175                         cpu_to_le32(1 << IEEE80211_RADIOTAP_DBM_ANTNOISE);
176                 pos++;
177         }
178
179         /* IEEE80211_RADIOTAP_LOCK_QUALITY is missing */
180
181         /* IEEE80211_RADIOTAP_ANTENNA */
182         *pos = status->antenna;
183         pos++;
184
185         /* IEEE80211_RADIOTAP_DB_ANTSIGNAL */
186         if (local->hw.flags & IEEE80211_HW_SIGNAL_DB) {
187                 *pos = status->signal;
188                 rthdr->it_present |=
189                         cpu_to_le32(1 << IEEE80211_RADIOTAP_DB_ANTSIGNAL);
190                 pos++;
191         }
192
193         /* IEEE80211_RADIOTAP_DB_ANTNOISE is not used */
194
195         /* IEEE80211_RADIOTAP_RX_FLAGS */
196         /* ensure 2 byte alignment for the 2 byte field as required */
197         if ((pos - (unsigned char *)rthdr) & 1)
198                 pos++;
199         /* FIXME: when radiotap gets a 'bad PLCP' flag use it here */
200         if (status->flag & (RX_FLAG_FAILED_FCS_CRC | RX_FLAG_FAILED_PLCP_CRC))
201                 *(__le16 *)pos |= cpu_to_le16(IEEE80211_RADIOTAP_F_RX_BADFCS);
202         pos += 2;
203 }
204
205 /*
206  * This function copies a received frame to all monitor interfaces and
207  * returns a cleaned-up SKB that no longer includes the FCS nor the
208  * radiotap header the driver might have added.
209  */
210 static struct sk_buff *
211 ieee80211_rx_monitor(struct ieee80211_local *local, struct sk_buff *origskb,
212                      struct ieee80211_rx_status *status,
213                      struct ieee80211_rate *rate)
214 {
215         struct ieee80211_sub_if_data *sdata;
216         int needed_headroom = 0;
217         struct sk_buff *skb, *skb2;
218         struct net_device *prev_dev = NULL;
219         int present_fcs_len = 0;
220         int rtap_len = 0;
221
222         /*
223          * First, we may need to make a copy of the skb because
224          *  (1) we need to modify it for radiotap (if not present), and
225          *  (2) the other RX handlers will modify the skb we got.
226          *
227          * We don't need to, of course, if we aren't going to return
228          * the SKB because it has a bad FCS/PLCP checksum.
229          */
230         if (status->flag & RX_FLAG_RADIOTAP)
231                 rtap_len = ieee80211_get_radiotap_len(origskb->data);
232         else
233                 /* room for the radiotap header based on driver features */
234                 needed_headroom = ieee80211_rx_radiotap_len(local, status);
235
236         if (local->hw.flags & IEEE80211_HW_RX_INCLUDES_FCS)
237                 present_fcs_len = FCS_LEN;
238
239         if (!local->monitors) {
240                 if (should_drop_frame(status, origskb, present_fcs_len,
241                                       rtap_len)) {
242                         dev_kfree_skb(origskb);
243                         return NULL;
244                 }
245
246                 return remove_monitor_info(local, origskb, rtap_len);
247         }
248
249         if (should_drop_frame(status, origskb, present_fcs_len, rtap_len)) {
250                 /* only need to expand headroom if necessary */
251                 skb = origskb;
252                 origskb = NULL;
253
254                 /*
255                  * This shouldn't trigger often because most devices have an
256                  * RX header they pull before we get here, and that should
257                  * be big enough for our radiotap information. We should
258                  * probably export the length to drivers so that we can have
259                  * them allocate enough headroom to start with.
260                  */
261                 if (skb_headroom(skb) < needed_headroom &&
262                     pskb_expand_head(skb, needed_headroom, 0, GFP_ATOMIC)) {
263                         dev_kfree_skb(skb);
264                         return NULL;
265                 }
266         } else {
267                 /*
268                  * Need to make a copy and possibly remove radiotap header
269                  * and FCS from the original.
270                  */
271                 skb = skb_copy_expand(origskb, needed_headroom, 0, GFP_ATOMIC);
272
273                 origskb = remove_monitor_info(local, origskb, rtap_len);
274
275                 if (!skb)
276                         return origskb;
277         }
278
279         /* if necessary, prepend radiotap information */
280         if (!(status->flag & RX_FLAG_RADIOTAP))
281                 ieee80211_add_rx_radiotap_header(local, skb, status, rate,
282                                                  needed_headroom);
283
284         skb_reset_mac_header(skb);
285         skb->ip_summed = CHECKSUM_UNNECESSARY;
286         skb->pkt_type = PACKET_OTHERHOST;
287         skb->protocol = htons(ETH_P_802_2);
288
289         list_for_each_entry_rcu(sdata, &local->interfaces, list) {
290                 if (!netif_running(sdata->dev))
291                         continue;
292
293                 if (sdata->vif.type != IEEE80211_IF_TYPE_MNTR)
294                         continue;
295
296                 if (sdata->u.mntr_flags & MONITOR_FLAG_COOK_FRAMES)
297                         continue;
298
299                 if (prev_dev) {
300                         skb2 = skb_clone(skb, GFP_ATOMIC);
301                         if (skb2) {
302                                 skb2->dev = prev_dev;
303                                 netif_rx(skb2);
304                         }
305                 }
306
307                 prev_dev = sdata->dev;
308                 sdata->dev->stats.rx_packets++;
309                 sdata->dev->stats.rx_bytes += skb->len;
310         }
311
312         if (prev_dev) {
313                 skb->dev = prev_dev;
314                 netif_rx(skb);
315         } else
316                 dev_kfree_skb(skb);
317
318         return origskb;
319 }
320
321
322 static void ieee80211_parse_qos(struct ieee80211_rx_data *rx)
323 {
324         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
325         int tid;
326
327         /* does the frame have a qos control field? */
328         if (ieee80211_is_data_qos(hdr->frame_control)) {
329                 u8 *qc = ieee80211_get_qos_ctl(hdr);
330                 /* frame has qos control */
331                 tid = *qc & IEEE80211_QOS_CTL_TID_MASK;
332                 if (*qc & IEEE80211_QOS_CONTROL_A_MSDU_PRESENT)
333                         rx->flags |= IEEE80211_RX_AMSDU;
334                 else
335                         rx->flags &= ~IEEE80211_RX_AMSDU;
336         } else {
337                 /*
338                  * IEEE 802.11-2007, 7.1.3.4.1 ("Sequence Number field"):
339                  *
340                  *      Sequence numbers for management frames, QoS data
341                  *      frames with a broadcast/multicast address in the
342                  *      Address 1 field, and all non-QoS data frames sent
343                  *      by QoS STAs are assigned using an additional single
344                  *      modulo-4096 counter, [...]
345                  *
346                  * We also use that counter for non-QoS STAs.
347                  */
348                 tid = NUM_RX_DATA_QUEUES - 1;
349         }
350
351         rx->queue = tid;
352         /* Set skb->priority to 1d tag if highest order bit of TID is not set.
353          * For now, set skb->priority to 0 for other cases. */
354         rx->skb->priority = (tid > 7) ? 0 : tid;
355 }
356
357 static void ieee80211_verify_ip_alignment(struct ieee80211_rx_data *rx)
358 {
359 #ifdef CONFIG_MAC80211_DEBUG_PACKET_ALIGNMENT
360         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
361         int hdrlen;
362
363         if (!ieee80211_is_data_present(hdr->frame_control))
364                 return;
365
366         /*
367          * Drivers are required to align the payload data in a way that
368          * guarantees that the contained IP header is aligned to a four-
369          * byte boundary. In the case of regular frames, this simply means
370          * aligning the payload to a four-byte boundary (because either
371          * the IP header is directly contained, or IV/RFC1042 headers that
372          * have a length divisible by four are in front of it.
373          *
374          * With A-MSDU frames, however, the payload data address must
375          * yield two modulo four because there are 14-byte 802.3 headers
376          * within the A-MSDU frames that push the IP header further back
377          * to a multiple of four again. Thankfully, the specs were sane
378          * enough this time around to require padding each A-MSDU subframe
379          * to a length that is a multiple of four.
380          *
381          * Padding like atheros hardware adds which is inbetween the 802.11
382          * header and the payload is not supported, the driver is required
383          * to move the 802.11 header further back in that case.
384          */
385         hdrlen = ieee80211_hdrlen(hdr->frame_control);
386         if (rx->flags & IEEE80211_RX_AMSDU)
387                 hdrlen += ETH_HLEN;
388         WARN_ON_ONCE(((unsigned long)(rx->skb->data + hdrlen)) & 3);
389 #endif
390 }
391
392
393 /* rx handlers */
394
395 static ieee80211_rx_result debug_noinline
396 ieee80211_rx_h_passive_scan(struct ieee80211_rx_data *rx)
397 {
398         struct ieee80211_local *local = rx->local;
399         struct sk_buff *skb = rx->skb;
400
401         if (unlikely(local->sta_hw_scanning))
402                 return ieee80211_sta_rx_scan(rx->dev, skb, rx->status);
403
404         if (unlikely(local->sta_sw_scanning)) {
405                 /* drop all the other packets during a software scan anyway */
406                 if (ieee80211_sta_rx_scan(rx->dev, skb, rx->status)
407                     != RX_QUEUED)
408                         dev_kfree_skb(skb);
409                 return RX_QUEUED;
410         }
411
412         if (unlikely(rx->flags & IEEE80211_RX_IN_SCAN)) {
413                 /* scanning finished during invoking of handlers */
414                 I802_DEBUG_INC(local->rx_handlers_drop_passive_scan);
415                 return RX_DROP_UNUSABLE;
416         }
417
418         return RX_CONTINUE;
419 }
420
421 static ieee80211_rx_result
422 ieee80211_rx_mesh_check(struct ieee80211_rx_data *rx)
423 {
424         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
425         unsigned int hdrlen = ieee80211_hdrlen(hdr->frame_control);
426
427         if (ieee80211_is_data(hdr->frame_control)) {
428                 if (!ieee80211_has_a4(hdr->frame_control))
429                         return RX_DROP_MONITOR;
430                 if (memcmp(hdr->addr4, rx->dev->dev_addr, ETH_ALEN) == 0)
431                         return RX_DROP_MONITOR;
432         }
433
434         /* If there is not an established peer link and this is not a peer link
435          * establisment frame, beacon or probe, drop the frame.
436          */
437
438         if (!rx->sta || sta_plink_state(rx->sta) != PLINK_ESTAB) {
439                 struct ieee80211_mgmt *mgmt;
440
441                 if (!ieee80211_is_mgmt(hdr->frame_control))
442                         return RX_DROP_MONITOR;
443
444                 if (ieee80211_is_action(hdr->frame_control)) {
445                         mgmt = (struct ieee80211_mgmt *)hdr;
446                         if (mgmt->u.action.category != PLINK_CATEGORY)
447                                 return RX_DROP_MONITOR;
448                         return RX_CONTINUE;
449                 }
450
451                 if (ieee80211_is_probe_req(hdr->frame_control) ||
452                     ieee80211_is_probe_resp(hdr->frame_control) ||
453                     ieee80211_is_beacon(hdr->frame_control))
454                         return RX_CONTINUE;
455
456                 return RX_DROP_MONITOR;
457
458         }
459
460 #define msh_h_get(h, l) ((struct ieee80211s_hdr *) ((u8 *)h + l))
461
462         if (ieee80211_is_data(hdr->frame_control) &&
463             is_multicast_ether_addr(hdr->addr1) &&
464             mesh_rmc_check(hdr->addr4, msh_h_get(hdr, hdrlen), rx->dev))
465                 return RX_DROP_MONITOR;
466 #undef msh_h_get
467
468         return RX_CONTINUE;
469 }
470
471
472 static ieee80211_rx_result debug_noinline
473 ieee80211_rx_h_check(struct ieee80211_rx_data *rx)
474 {
475         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
476
477         /* Drop duplicate 802.11 retransmissions (IEEE 802.11 Chap. 9.2.9) */
478         if (rx->sta && !is_multicast_ether_addr(hdr->addr1)) {
479                 if (unlikely(ieee80211_has_retry(hdr->frame_control) &&
480                              rx->sta->last_seq_ctrl[rx->queue] ==
481                              hdr->seq_ctrl)) {
482                         if (rx->flags & IEEE80211_RX_RA_MATCH) {
483                                 rx->local->dot11FrameDuplicateCount++;
484                                 rx->sta->num_duplicates++;
485                         }
486                         return RX_DROP_MONITOR;
487                 } else
488                         rx->sta->last_seq_ctrl[rx->queue] = hdr->seq_ctrl;
489         }
490
491         if (unlikely(rx->skb->len < 16)) {
492                 I802_DEBUG_INC(rx->local->rx_handlers_drop_short);
493                 return RX_DROP_MONITOR;
494         }
495
496         /* Drop disallowed frame classes based on STA auth/assoc state;
497          * IEEE 802.11, Chap 5.5.
498          *
499          * 80211.o does filtering only based on association state, i.e., it
500          * drops Class 3 frames from not associated stations. hostapd sends
501          * deauth/disassoc frames when needed. In addition, hostapd is
502          * responsible for filtering on both auth and assoc states.
503          */
504
505         if (ieee80211_vif_is_mesh(&rx->sdata->vif))
506                 return ieee80211_rx_mesh_check(rx);
507
508         if (unlikely((ieee80211_is_data(hdr->frame_control) ||
509                       ieee80211_is_pspoll(hdr->frame_control)) &&
510                      rx->sdata->vif.type != IEEE80211_IF_TYPE_IBSS &&
511                      (!rx->sta || !test_sta_flags(rx->sta, WLAN_STA_ASSOC)))) {
512                 if ((!ieee80211_has_fromds(hdr->frame_control) &&
513                      !ieee80211_has_tods(hdr->frame_control) &&
514                      ieee80211_is_data(hdr->frame_control)) ||
515                     !(rx->flags & IEEE80211_RX_RA_MATCH)) {
516                         /* Drop IBSS frames and frames for other hosts
517                          * silently. */
518                         return RX_DROP_MONITOR;
519                 }
520
521                 return RX_DROP_MONITOR;
522         }
523
524         return RX_CONTINUE;
525 }
526
527
528 static ieee80211_rx_result debug_noinline
529 ieee80211_rx_h_decrypt(struct ieee80211_rx_data *rx)
530 {
531         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
532         int keyidx;
533         int hdrlen;
534         ieee80211_rx_result result = RX_DROP_UNUSABLE;
535         struct ieee80211_key *stakey = NULL;
536
537         /*
538          * Key selection 101
539          *
540          * There are three types of keys:
541          *  - GTK (group keys)
542          *  - PTK (pairwise keys)
543          *  - STK (station-to-station pairwise keys)
544          *
545          * When selecting a key, we have to distinguish between multicast
546          * (including broadcast) and unicast frames, the latter can only
547          * use PTKs and STKs while the former always use GTKs. Unless, of
548          * course, actual WEP keys ("pre-RSNA") are used, then unicast
549          * frames can also use key indizes like GTKs. Hence, if we don't
550          * have a PTK/STK we check the key index for a WEP key.
551          *
552          * Note that in a regular BSS, multicast frames are sent by the
553          * AP only, associated stations unicast the frame to the AP first
554          * which then multicasts it on their behalf.
555          *
556          * There is also a slight problem in IBSS mode: GTKs are negotiated
557          * with each station, that is something we don't currently handle.
558          * The spec seems to expect that one negotiates the same key with
559          * every station but there's no such requirement; VLANs could be
560          * possible.
561          */
562
563         if (!ieee80211_has_protected(hdr->frame_control))
564                 return RX_CONTINUE;
565
566         /*
567          * No point in finding a key and decrypting if the frame is neither
568          * addressed to us nor a multicast frame.
569          */
570         if (!(rx->flags & IEEE80211_RX_RA_MATCH))
571                 return RX_CONTINUE;
572
573         if (rx->sta)
574                 stakey = rcu_dereference(rx->sta->key);
575
576         if (!is_multicast_ether_addr(hdr->addr1) && stakey) {
577                 rx->key = stakey;
578         } else {
579                 /*
580                  * The device doesn't give us the IV so we won't be
581                  * able to look up the key. That's ok though, we
582                  * don't need to decrypt the frame, we just won't
583                  * be able to keep statistics accurate.
584                  * Except for key threshold notifications, should
585                  * we somehow allow the driver to tell us which key
586                  * the hardware used if this flag is set?
587                  */
588                 if ((rx->status->flag & RX_FLAG_DECRYPTED) &&
589                     (rx->status->flag & RX_FLAG_IV_STRIPPED))
590                         return RX_CONTINUE;
591
592                 hdrlen = ieee80211_hdrlen(hdr->frame_control);
593
594                 if (rx->skb->len < 8 + hdrlen)
595                         return RX_DROP_UNUSABLE; /* TODO: count this? */
596
597                 /*
598                  * no need to call ieee80211_wep_get_keyidx,
599                  * it verifies a bunch of things we've done already
600                  */
601                 keyidx = rx->skb->data[hdrlen + 3] >> 6;
602
603                 rx->key = rcu_dereference(rx->sdata->keys[keyidx]);
604
605                 /*
606                  * RSNA-protected unicast frames should always be sent with
607                  * pairwise or station-to-station keys, but for WEP we allow
608                  * using a key index as well.
609                  */
610                 if (rx->key && rx->key->conf.alg != ALG_WEP &&
611                     !is_multicast_ether_addr(hdr->addr1))
612                         rx->key = NULL;
613         }
614
615         if (rx->key) {
616                 rx->key->tx_rx_count++;
617                 /* TODO: add threshold stuff again */
618         } else {
619                 return RX_DROP_MONITOR;
620         }
621
622         /* Check for weak IVs if possible */
623         if (rx->sta && rx->key->conf.alg == ALG_WEP &&
624             ieee80211_is_data(hdr->frame_control) &&
625             (!(rx->status->flag & RX_FLAG_IV_STRIPPED) ||
626              !(rx->status->flag & RX_FLAG_DECRYPTED)) &&
627             ieee80211_wep_is_weak_iv(rx->skb, rx->key))
628                 rx->sta->wep_weak_iv_count++;
629
630         switch (rx->key->conf.alg) {
631         case ALG_WEP:
632                 result = ieee80211_crypto_wep_decrypt(rx);
633                 break;
634         case ALG_TKIP:
635                 result = ieee80211_crypto_tkip_decrypt(rx);
636                 break;
637         case ALG_CCMP:
638                 result = ieee80211_crypto_ccmp_decrypt(rx);
639                 break;
640         }
641
642         /* either the frame has been decrypted or will be dropped */
643         rx->status->flag |= RX_FLAG_DECRYPTED;
644
645         return result;
646 }
647
648 static void ap_sta_ps_start(struct net_device *dev, struct sta_info *sta)
649 {
650         struct ieee80211_sub_if_data *sdata;
651         DECLARE_MAC_BUF(mac);
652
653         sdata = sta->sdata;
654
655         atomic_inc(&sdata->bss->num_sta_ps);
656         set_and_clear_sta_flags(sta, WLAN_STA_PS, WLAN_STA_PSPOLL);
657 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
658         printk(KERN_DEBUG "%s: STA %s aid %d enters power save mode\n",
659                dev->name, print_mac(mac, sta->addr), sta->aid);
660 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
661 }
662
663 static int ap_sta_ps_end(struct net_device *dev, struct sta_info *sta)
664 {
665         struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
666         struct sk_buff *skb;
667         int sent = 0;
668         struct ieee80211_sub_if_data *sdata;
669         struct ieee80211_tx_info *info;
670         DECLARE_MAC_BUF(mac);
671
672         sdata = sta->sdata;
673
674         atomic_dec(&sdata->bss->num_sta_ps);
675
676         clear_sta_flags(sta, WLAN_STA_PS | WLAN_STA_PSPOLL);
677
678         if (!skb_queue_empty(&sta->ps_tx_buf))
679                 sta_info_clear_tim_bit(sta);
680
681 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
682         printk(KERN_DEBUG "%s: STA %s aid %d exits power save mode\n",
683                dev->name, print_mac(mac, sta->addr), sta->aid);
684 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
685
686         /* Send all buffered frames to the station */
687         while ((skb = skb_dequeue(&sta->tx_filtered)) != NULL) {
688                 info = IEEE80211_SKB_CB(skb);
689                 sent++;
690                 info->flags |= IEEE80211_TX_CTL_REQUEUE;
691                 dev_queue_xmit(skb);
692         }
693         while ((skb = skb_dequeue(&sta->ps_tx_buf)) != NULL) {
694                 info = IEEE80211_SKB_CB(skb);
695                 local->total_ps_buffered--;
696                 sent++;
697 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
698                 printk(KERN_DEBUG "%s: STA %s aid %d send PS frame "
699                        "since STA not sleeping anymore\n", dev->name,
700                        print_mac(mac, sta->addr), sta->aid);
701 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
702                 info->flags |= IEEE80211_TX_CTL_REQUEUE;
703                 dev_queue_xmit(skb);
704         }
705
706         return sent;
707 }
708
709 static ieee80211_rx_result debug_noinline
710 ieee80211_rx_h_sta_process(struct ieee80211_rx_data *rx)
711 {
712         struct sta_info *sta = rx->sta;
713         struct net_device *dev = rx->dev;
714         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
715
716         if (!sta)
717                 return RX_CONTINUE;
718
719         /* Update last_rx only for IBSS packets which are for the current
720          * BSSID to avoid keeping the current IBSS network alive in cases where
721          * other STAs are using different BSSID. */
722         if (rx->sdata->vif.type == IEEE80211_IF_TYPE_IBSS) {
723                 u8 *bssid = ieee80211_get_bssid(hdr, rx->skb->len,
724                                                 IEEE80211_IF_TYPE_IBSS);
725                 if (compare_ether_addr(bssid, rx->sdata->u.sta.bssid) == 0)
726                         sta->last_rx = jiffies;
727         } else
728         if (!is_multicast_ether_addr(hdr->addr1) ||
729             rx->sdata->vif.type == IEEE80211_IF_TYPE_STA) {
730                 /* Update last_rx only for unicast frames in order to prevent
731                  * the Probe Request frames (the only broadcast frames from a
732                  * STA in infrastructure mode) from keeping a connection alive.
733                  * Mesh beacons will update last_rx when if they are found to
734                  * match the current local configuration when processed.
735                  */
736                 sta->last_rx = jiffies;
737         }
738
739         if (!(rx->flags & IEEE80211_RX_RA_MATCH))
740                 return RX_CONTINUE;
741
742         sta->rx_fragments++;
743         sta->rx_bytes += rx->skb->len;
744         sta->last_signal = rx->status->signal;
745         sta->last_qual = rx->status->qual;
746         sta->last_noise = rx->status->noise;
747
748         if (!ieee80211_has_morefrags(hdr->frame_control) &&
749             (rx->sdata->vif.type == IEEE80211_IF_TYPE_AP ||
750              rx->sdata->vif.type == IEEE80211_IF_TYPE_VLAN)) {
751                 /* Change STA power saving mode only in the end of a frame
752                  * exchange sequence */
753                 if (test_sta_flags(sta, WLAN_STA_PS) &&
754                     !ieee80211_has_pm(hdr->frame_control))
755                         rx->sent_ps_buffered += ap_sta_ps_end(dev, sta);
756                 else if (!test_sta_flags(sta, WLAN_STA_PS) &&
757                          ieee80211_has_pm(hdr->frame_control))
758                         ap_sta_ps_start(dev, sta);
759         }
760
761         /* Drop data::nullfunc frames silently, since they are used only to
762          * control station power saving mode. */
763         if (ieee80211_is_nullfunc(hdr->frame_control)) {
764                 I802_DEBUG_INC(rx->local->rx_handlers_drop_nullfunc);
765                 /* Update counter and free packet here to avoid counting this
766                  * as a dropped packed. */
767                 sta->rx_packets++;
768                 dev_kfree_skb(rx->skb);
769                 return RX_QUEUED;
770         }
771
772         return RX_CONTINUE;
773 } /* ieee80211_rx_h_sta_process */
774
775 static inline struct ieee80211_fragment_entry *
776 ieee80211_reassemble_add(struct ieee80211_sub_if_data *sdata,
777                          unsigned int frag, unsigned int seq, int rx_queue,
778                          struct sk_buff **skb)
779 {
780         struct ieee80211_fragment_entry *entry;
781         int idx;
782
783         idx = sdata->fragment_next;
784         entry = &sdata->fragments[sdata->fragment_next++];
785         if (sdata->fragment_next >= IEEE80211_FRAGMENT_MAX)
786                 sdata->fragment_next = 0;
787
788         if (!skb_queue_empty(&entry->skb_list)) {
789 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG
790                 struct ieee80211_hdr *hdr =
791                         (struct ieee80211_hdr *) entry->skb_list.next->data;
792                 DECLARE_MAC_BUF(mac);
793                 DECLARE_MAC_BUF(mac2);
794                 printk(KERN_DEBUG "%s: RX reassembly removed oldest "
795                        "fragment entry (idx=%d age=%lu seq=%d last_frag=%d "
796                        "addr1=%s addr2=%s\n",
797                        sdata->dev->name, idx,
798                        jiffies - entry->first_frag_time, entry->seq,
799                        entry->last_frag, print_mac(mac, hdr->addr1),
800                        print_mac(mac2, hdr->addr2));
801 #endif
802                 __skb_queue_purge(&entry->skb_list);
803         }
804
805         __skb_queue_tail(&entry->skb_list, *skb); /* no need for locking */
806         *skb = NULL;
807         entry->first_frag_time = jiffies;
808         entry->seq = seq;
809         entry->rx_queue = rx_queue;
810         entry->last_frag = frag;
811         entry->ccmp = 0;
812         entry->extra_len = 0;
813
814         return entry;
815 }
816
817 static inline struct ieee80211_fragment_entry *
818 ieee80211_reassemble_find(struct ieee80211_sub_if_data *sdata,
819                           u16 fc, unsigned int frag, unsigned int seq,
820                           int rx_queue, struct ieee80211_hdr *hdr)
821 {
822         struct ieee80211_fragment_entry *entry;
823         int i, idx;
824
825         idx = sdata->fragment_next;
826         for (i = 0; i < IEEE80211_FRAGMENT_MAX; i++) {
827                 struct ieee80211_hdr *f_hdr;
828                 u16 f_fc;
829
830                 idx--;
831                 if (idx < 0)
832                         idx = IEEE80211_FRAGMENT_MAX - 1;
833
834                 entry = &sdata->fragments[idx];
835                 if (skb_queue_empty(&entry->skb_list) || entry->seq != seq ||
836                     entry->rx_queue != rx_queue ||
837                     entry->last_frag + 1 != frag)
838                         continue;
839
840                 f_hdr = (struct ieee80211_hdr *) entry->skb_list.next->data;
841                 f_fc = le16_to_cpu(f_hdr->frame_control);
842
843                 if ((fc & IEEE80211_FCTL_FTYPE) != (f_fc & IEEE80211_FCTL_FTYPE) ||
844                     compare_ether_addr(hdr->addr1, f_hdr->addr1) != 0 ||
845                     compare_ether_addr(hdr->addr2, f_hdr->addr2) != 0)
846                         continue;
847
848                 if (time_after(jiffies, entry->first_frag_time + 2 * HZ)) {
849                         __skb_queue_purge(&entry->skb_list);
850                         continue;
851                 }
852                 return entry;
853         }
854
855         return NULL;
856 }
857
858 static ieee80211_rx_result debug_noinline
859 ieee80211_rx_h_defragment(struct ieee80211_rx_data *rx)
860 {
861         struct ieee80211_hdr *hdr;
862         u16 sc;
863         unsigned int frag, seq;
864         struct ieee80211_fragment_entry *entry;
865         struct sk_buff *skb;
866         DECLARE_MAC_BUF(mac);
867
868         hdr = (struct ieee80211_hdr *) rx->skb->data;
869         sc = le16_to_cpu(hdr->seq_ctrl);
870         frag = sc & IEEE80211_SCTL_FRAG;
871
872         if (likely((!(rx->fc & IEEE80211_FCTL_MOREFRAGS) && frag == 0) ||
873                    (rx->skb)->len < 24 ||
874                    is_multicast_ether_addr(hdr->addr1))) {
875                 /* not fragmented */
876                 goto out;
877         }
878         I802_DEBUG_INC(rx->local->rx_handlers_fragments);
879
880         seq = (sc & IEEE80211_SCTL_SEQ) >> 4;
881
882         if (frag == 0) {
883                 /* This is the first fragment of a new frame. */
884                 entry = ieee80211_reassemble_add(rx->sdata, frag, seq,
885                                                  rx->queue, &(rx->skb));
886                 if (rx->key && rx->key->conf.alg == ALG_CCMP &&
887                     (rx->fc & IEEE80211_FCTL_PROTECTED)) {
888                         /* Store CCMP PN so that we can verify that the next
889                          * fragment has a sequential PN value. */
890                         entry->ccmp = 1;
891                         memcpy(entry->last_pn,
892                                rx->key->u.ccmp.rx_pn[rx->queue],
893                                CCMP_PN_LEN);
894                 }
895                 return RX_QUEUED;
896         }
897
898         /* This is a fragment for a frame that should already be pending in
899          * fragment cache. Add this fragment to the end of the pending entry.
900          */
901         entry = ieee80211_reassemble_find(rx->sdata, rx->fc, frag, seq,
902                                           rx->queue, hdr);
903         if (!entry) {
904                 I802_DEBUG_INC(rx->local->rx_handlers_drop_defrag);
905                 return RX_DROP_MONITOR;
906         }
907
908         /* Verify that MPDUs within one MSDU have sequential PN values.
909          * (IEEE 802.11i, 8.3.3.4.5) */
910         if (entry->ccmp) {
911                 int i;
912                 u8 pn[CCMP_PN_LEN], *rpn;
913                 if (!rx->key || rx->key->conf.alg != ALG_CCMP)
914                         return RX_DROP_UNUSABLE;
915                 memcpy(pn, entry->last_pn, CCMP_PN_LEN);
916                 for (i = CCMP_PN_LEN - 1; i >= 0; i--) {
917                         pn[i]++;
918                         if (pn[i])
919                                 break;
920                 }
921                 rpn = rx->key->u.ccmp.rx_pn[rx->queue];
922                 if (memcmp(pn, rpn, CCMP_PN_LEN))
923                         return RX_DROP_UNUSABLE;
924                 memcpy(entry->last_pn, pn, CCMP_PN_LEN);
925         }
926
927         skb_pull(rx->skb, ieee80211_get_hdrlen(rx->fc));
928         __skb_queue_tail(&entry->skb_list, rx->skb);
929         entry->last_frag = frag;
930         entry->extra_len += rx->skb->len;
931         if (rx->fc & IEEE80211_FCTL_MOREFRAGS) {
932                 rx->skb = NULL;
933                 return RX_QUEUED;
934         }
935
936         rx->skb = __skb_dequeue(&entry->skb_list);
937         if (skb_tailroom(rx->skb) < entry->extra_len) {
938                 I802_DEBUG_INC(rx->local->rx_expand_skb_head2);
939                 if (unlikely(pskb_expand_head(rx->skb, 0, entry->extra_len,
940                                               GFP_ATOMIC))) {
941                         I802_DEBUG_INC(rx->local->rx_handlers_drop_defrag);
942                         __skb_queue_purge(&entry->skb_list);
943                         return RX_DROP_UNUSABLE;
944                 }
945         }
946         while ((skb = __skb_dequeue(&entry->skb_list))) {
947                 memcpy(skb_put(rx->skb, skb->len), skb->data, skb->len);
948                 dev_kfree_skb(skb);
949         }
950
951         /* Complete frame has been reassembled - process it now */
952         rx->flags |= IEEE80211_RX_FRAGMENTED;
953
954  out:
955         if (rx->sta)
956                 rx->sta->rx_packets++;
957         if (is_multicast_ether_addr(hdr->addr1))
958                 rx->local->dot11MulticastReceivedFrameCount++;
959         else
960                 ieee80211_led_rx(rx->local);
961         return RX_CONTINUE;
962 }
963
964 static ieee80211_rx_result debug_noinline
965 ieee80211_rx_h_ps_poll(struct ieee80211_rx_data *rx)
966 {
967         struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(rx->dev);
968         struct sk_buff *skb;
969         int no_pending_pkts;
970         DECLARE_MAC_BUF(mac);
971
972         if (likely(!rx->sta ||
973                    (rx->fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_CTL ||
974                    (rx->fc & IEEE80211_FCTL_STYPE) != IEEE80211_STYPE_PSPOLL ||
975                    !(rx->flags & IEEE80211_RX_RA_MATCH)))
976                 return RX_CONTINUE;
977
978         if ((sdata->vif.type != IEEE80211_IF_TYPE_AP) &&
979             (sdata->vif.type != IEEE80211_IF_TYPE_VLAN))
980                 return RX_DROP_UNUSABLE;
981
982         skb = skb_dequeue(&rx->sta->tx_filtered);
983         if (!skb) {
984                 skb = skb_dequeue(&rx->sta->ps_tx_buf);
985                 if (skb)
986                         rx->local->total_ps_buffered--;
987         }
988         no_pending_pkts = skb_queue_empty(&rx->sta->tx_filtered) &&
989                 skb_queue_empty(&rx->sta->ps_tx_buf);
990
991         if (skb) {
992                 struct ieee80211_hdr *hdr =
993                         (struct ieee80211_hdr *) skb->data;
994
995                 /*
996                  * Tell TX path to send one frame even though the STA may
997                  * still remain is PS mode after this frame exchange.
998                  */
999                 set_sta_flags(rx->sta, WLAN_STA_PSPOLL);
1000
1001 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
1002                 printk(KERN_DEBUG "STA %s aid %d: PS Poll (entries after %d)\n",
1003                        print_mac(mac, rx->sta->addr), rx->sta->aid,
1004                        skb_queue_len(&rx->sta->ps_tx_buf));
1005 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
1006
1007                 /* Use MoreData flag to indicate whether there are more
1008                  * buffered frames for this STA */
1009                 if (no_pending_pkts)
1010                         hdr->frame_control &= cpu_to_le16(~IEEE80211_FCTL_MOREDATA);
1011                 else
1012                         hdr->frame_control |= cpu_to_le16(IEEE80211_FCTL_MOREDATA);
1013
1014                 dev_queue_xmit(skb);
1015
1016                 if (no_pending_pkts)
1017                         sta_info_clear_tim_bit(rx->sta);
1018 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
1019         } else if (!rx->sent_ps_buffered) {
1020                 /*
1021                  * FIXME: This can be the result of a race condition between
1022                  *        us expiring a frame and the station polling for it.
1023                  *        Should we send it a null-func frame indicating we
1024                  *        have nothing buffered for it?
1025                  */
1026                 printk(KERN_DEBUG "%s: STA %s sent PS Poll even "
1027                        "though there are no buffered frames for it\n",
1028                        rx->dev->name, print_mac(mac, rx->sta->addr));
1029 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
1030         }
1031
1032         /* Free PS Poll skb here instead of returning RX_DROP that would
1033          * count as an dropped frame. */
1034         dev_kfree_skb(rx->skb);
1035
1036         return RX_QUEUED;
1037 }
1038
1039 static ieee80211_rx_result debug_noinline
1040 ieee80211_rx_h_remove_qos_control(struct ieee80211_rx_data *rx)
1041 {
1042         u8 *data = rx->skb->data;
1043         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)data;
1044
1045         if (!ieee80211_is_data_qos(hdr->frame_control))
1046                 return RX_CONTINUE;
1047
1048         /* remove the qos control field, update frame type and meta-data */
1049         memmove(data + IEEE80211_QOS_CTL_LEN, data,
1050                 ieee80211_hdrlen(hdr->frame_control) - IEEE80211_QOS_CTL_LEN);
1051         hdr = (struct ieee80211_hdr *)skb_pull(rx->skb, IEEE80211_QOS_CTL_LEN);
1052         /* change frame type to non QOS */
1053         rx->fc &= ~IEEE80211_STYPE_QOS_DATA;
1054         hdr->frame_control &= ~cpu_to_le16(IEEE80211_STYPE_QOS_DATA);
1055
1056         return RX_CONTINUE;
1057 }
1058
1059 static int
1060 ieee80211_802_1x_port_control(struct ieee80211_rx_data *rx)
1061 {
1062         if (unlikely(!rx->sta ||
1063             !test_sta_flags(rx->sta, WLAN_STA_AUTHORIZED)))
1064                 return -EACCES;
1065
1066         return 0;
1067 }
1068
1069 static int
1070 ieee80211_drop_unencrypted(struct ieee80211_rx_data *rx)
1071 {
1072         /*
1073          * Pass through unencrypted frames if the hardware has
1074          * decrypted them already.
1075          */
1076         if (rx->status->flag & RX_FLAG_DECRYPTED)
1077                 return 0;
1078
1079         /* Drop unencrypted frames if key is set. */
1080         if (unlikely(!(rx->fc & IEEE80211_FCTL_PROTECTED) &&
1081                      (rx->fc & IEEE80211_FCTL_FTYPE) == IEEE80211_FTYPE_DATA &&
1082                      (rx->fc & IEEE80211_FCTL_STYPE) != IEEE80211_STYPE_NULLFUNC &&
1083                      (rx->key || rx->sdata->drop_unencrypted)))
1084                 return -EACCES;
1085
1086         return 0;
1087 }
1088
1089 static int
1090 ieee80211_data_to_8023(struct ieee80211_rx_data *rx)
1091 {
1092         struct net_device *dev = rx->dev;
1093         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) rx->skb->data;
1094         u16 fc, hdrlen, ethertype;
1095         u8 *payload;
1096         u8 dst[ETH_ALEN];
1097         u8 src[ETH_ALEN] __aligned(2);
1098         struct sk_buff *skb = rx->skb;
1099         struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
1100         DECLARE_MAC_BUF(mac);
1101         DECLARE_MAC_BUF(mac2);
1102         DECLARE_MAC_BUF(mac3);
1103         DECLARE_MAC_BUF(mac4);
1104
1105         fc = rx->fc;
1106
1107         if (unlikely(!WLAN_FC_DATA_PRESENT(fc)))
1108                 return -1;
1109
1110         hdrlen = ieee80211_get_hdrlen(fc);
1111
1112         if (ieee80211_vif_is_mesh(&sdata->vif))
1113                 hdrlen += ieee80211_get_mesh_hdrlen(
1114                                 (struct ieee80211s_hdr *) (skb->data + hdrlen));
1115
1116         /* convert IEEE 802.11 header + possible LLC headers into Ethernet
1117          * header
1118          * IEEE 802.11 address fields:
1119          * ToDS FromDS Addr1 Addr2 Addr3 Addr4
1120          *   0     0   DA    SA    BSSID n/a
1121          *   0     1   DA    BSSID SA    n/a
1122          *   1     0   BSSID SA    DA    n/a
1123          *   1     1   RA    TA    DA    SA
1124          */
1125
1126         switch (fc & (IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS)) {
1127         case IEEE80211_FCTL_TODS:
1128                 /* BSSID SA DA */
1129                 memcpy(dst, hdr->addr3, ETH_ALEN);
1130                 memcpy(src, hdr->addr2, ETH_ALEN);
1131
1132                 if (unlikely(sdata->vif.type != IEEE80211_IF_TYPE_AP &&
1133                              sdata->vif.type != IEEE80211_IF_TYPE_VLAN))
1134                         return -1;
1135                 break;
1136         case (IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS):
1137                 /* RA TA DA SA */
1138                 memcpy(dst, hdr->addr3, ETH_ALEN);
1139                 memcpy(src, hdr->addr4, ETH_ALEN);
1140
1141                  if (unlikely(sdata->vif.type != IEEE80211_IF_TYPE_WDS &&
1142                              sdata->vif.type != IEEE80211_IF_TYPE_MESH_POINT))
1143                         return -1;
1144                 break;
1145         case IEEE80211_FCTL_FROMDS:
1146                 /* DA BSSID SA */
1147                 memcpy(dst, hdr->addr1, ETH_ALEN);
1148                 memcpy(src, hdr->addr3, ETH_ALEN);
1149
1150                 if (sdata->vif.type != IEEE80211_IF_TYPE_STA ||
1151                     (is_multicast_ether_addr(dst) &&
1152                      !compare_ether_addr(src, dev->dev_addr)))
1153                         return -1;
1154                 break;
1155         case 0:
1156                 /* DA SA BSSID */
1157                 memcpy(dst, hdr->addr1, ETH_ALEN);
1158                 memcpy(src, hdr->addr2, ETH_ALEN);
1159
1160                 if (sdata->vif.type != IEEE80211_IF_TYPE_IBSS)
1161                         return -1;
1162                 break;
1163         }
1164
1165         if (unlikely(skb->len - hdrlen < 8))
1166                 return -1;
1167
1168         payload = skb->data + hdrlen;
1169         ethertype = (payload[6] << 8) | payload[7];
1170
1171         if (likely((compare_ether_addr(payload, rfc1042_header) == 0 &&
1172                     ethertype != ETH_P_AARP && ethertype != ETH_P_IPX) ||
1173                    compare_ether_addr(payload, bridge_tunnel_header) == 0)) {
1174                 /* remove RFC1042 or Bridge-Tunnel encapsulation and
1175                  * replace EtherType */
1176                 skb_pull(skb, hdrlen + 6);
1177                 memcpy(skb_push(skb, ETH_ALEN), src, ETH_ALEN);
1178                 memcpy(skb_push(skb, ETH_ALEN), dst, ETH_ALEN);
1179         } else {
1180                 struct ethhdr *ehdr;
1181                 __be16 len;
1182
1183                 skb_pull(skb, hdrlen);
1184                 len = htons(skb->len);
1185                 ehdr = (struct ethhdr *) skb_push(skb, sizeof(struct ethhdr));
1186                 memcpy(ehdr->h_dest, dst, ETH_ALEN);
1187                 memcpy(ehdr->h_source, src, ETH_ALEN);
1188                 ehdr->h_proto = len;
1189         }
1190         return 0;
1191 }
1192
1193 /*
1194  * requires that rx->skb is a frame with ethernet header
1195  */
1196 static bool ieee80211_frame_allowed(struct ieee80211_rx_data *rx)
1197 {
1198         static const u8 pae_group_addr[ETH_ALEN] __aligned(2)
1199                 = { 0x01, 0x80, 0xC2, 0x00, 0x00, 0x03 };
1200         struct ethhdr *ehdr = (struct ethhdr *) rx->skb->data;
1201
1202         /*
1203          * Allow EAPOL frames to us/the PAE group address regardless
1204          * of whether the frame was encrypted or not.
1205          */
1206         if (ehdr->h_proto == htons(ETH_P_PAE) &&
1207             (compare_ether_addr(ehdr->h_dest, rx->dev->dev_addr) == 0 ||
1208              compare_ether_addr(ehdr->h_dest, pae_group_addr) == 0))
1209                 return true;
1210
1211         if (ieee80211_802_1x_port_control(rx) ||
1212             ieee80211_drop_unencrypted(rx))
1213                 return false;
1214
1215         return true;
1216 }
1217
1218 /*
1219  * requires that rx->skb is a frame with ethernet header
1220  */
1221 static void
1222 ieee80211_deliver_skb(struct ieee80211_rx_data *rx)
1223 {
1224         struct net_device *dev = rx->dev;
1225         struct ieee80211_local *local = rx->local;
1226         struct sk_buff *skb, *xmit_skb;
1227         struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
1228         struct ethhdr *ehdr = (struct ethhdr *) rx->skb->data;
1229         struct sta_info *dsta;
1230
1231         skb = rx->skb;
1232         xmit_skb = NULL;
1233
1234         if (local->bridge_packets && (sdata->vif.type == IEEE80211_IF_TYPE_AP ||
1235                                       sdata->vif.type == IEEE80211_IF_TYPE_VLAN) &&
1236             (rx->flags & IEEE80211_RX_RA_MATCH)) {
1237                 if (is_multicast_ether_addr(ehdr->h_dest)) {
1238                         /*
1239                          * send multicast frames both to higher layers in
1240                          * local net stack and back to the wireless medium
1241                          */
1242                         xmit_skb = skb_copy(skb, GFP_ATOMIC);
1243                         if (!xmit_skb && net_ratelimit())
1244                                 printk(KERN_DEBUG "%s: failed to clone "
1245                                        "multicast frame\n", dev->name);
1246                 } else {
1247                         dsta = sta_info_get(local, skb->data);
1248                         if (dsta && dsta->sdata->dev == dev) {
1249                                 /*
1250                                  * The destination station is associated to
1251                                  * this AP (in this VLAN), so send the frame
1252                                  * directly to it and do not pass it to local
1253                                  * net stack.
1254                                  */
1255                                 xmit_skb = skb;
1256                                 skb = NULL;
1257                         }
1258                 }
1259         }
1260
1261         if (skb) {
1262                 /* deliver to local stack */
1263                 skb->protocol = eth_type_trans(skb, dev);
1264                 memset(skb->cb, 0, sizeof(skb->cb));
1265                 netif_rx(skb);
1266         }
1267
1268         if (xmit_skb) {
1269                 /* send to wireless media */
1270                 xmit_skb->protocol = htons(ETH_P_802_3);
1271                 skb_reset_network_header(xmit_skb);
1272                 skb_reset_mac_header(xmit_skb);
1273                 dev_queue_xmit(xmit_skb);
1274         }
1275 }
1276
1277 static ieee80211_rx_result debug_noinline
1278 ieee80211_rx_h_amsdu(struct ieee80211_rx_data *rx)
1279 {
1280         struct net_device *dev = rx->dev;
1281         struct ieee80211_local *local = rx->local;
1282         u16 fc, ethertype;
1283         u8 *payload;
1284         struct sk_buff *skb = rx->skb, *frame = NULL;
1285         const struct ethhdr *eth;
1286         int remaining, err;
1287         u8 dst[ETH_ALEN];
1288         u8 src[ETH_ALEN];
1289         DECLARE_MAC_BUF(mac);
1290
1291         fc = rx->fc;
1292         if (unlikely((fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_DATA))
1293                 return RX_CONTINUE;
1294
1295         if (unlikely(!WLAN_FC_DATA_PRESENT(fc)))
1296                 return RX_DROP_MONITOR;
1297
1298         if (!(rx->flags & IEEE80211_RX_AMSDU))
1299                 return RX_CONTINUE;
1300
1301         err = ieee80211_data_to_8023(rx);
1302         if (unlikely(err))
1303                 return RX_DROP_UNUSABLE;
1304
1305         skb->dev = dev;
1306
1307         dev->stats.rx_packets++;
1308         dev->stats.rx_bytes += skb->len;
1309
1310         /* skip the wrapping header */
1311         eth = (struct ethhdr *) skb_pull(skb, sizeof(struct ethhdr));
1312         if (!eth)
1313                 return RX_DROP_UNUSABLE;
1314
1315         while (skb != frame) {
1316                 u8 padding;
1317                 __be16 len = eth->h_proto;
1318                 unsigned int subframe_len = sizeof(struct ethhdr) + ntohs(len);
1319
1320                 remaining = skb->len;
1321                 memcpy(dst, eth->h_dest, ETH_ALEN);
1322                 memcpy(src, eth->h_source, ETH_ALEN);
1323
1324                 padding = ((4 - subframe_len) & 0x3);
1325                 /* the last MSDU has no padding */
1326                 if (subframe_len > remaining)
1327                         return RX_DROP_UNUSABLE;
1328
1329                 skb_pull(skb, sizeof(struct ethhdr));
1330                 /* if last subframe reuse skb */
1331                 if (remaining <= subframe_len + padding)
1332                         frame = skb;
1333                 else {
1334                         frame = dev_alloc_skb(local->hw.extra_tx_headroom +
1335                                               subframe_len);
1336
1337                         if (frame == NULL)
1338                                 return RX_DROP_UNUSABLE;
1339
1340                         skb_reserve(frame, local->hw.extra_tx_headroom +
1341                                     sizeof(struct ethhdr));
1342                         memcpy(skb_put(frame, ntohs(len)), skb->data,
1343                                 ntohs(len));
1344
1345                         eth = (struct ethhdr *) skb_pull(skb, ntohs(len) +
1346                                                         padding);
1347                         if (!eth) {
1348                                 dev_kfree_skb(frame);
1349                                 return RX_DROP_UNUSABLE;
1350                         }
1351                 }
1352
1353                 skb_reset_network_header(frame);
1354                 frame->dev = dev;
1355                 frame->priority = skb->priority;
1356                 rx->skb = frame;
1357
1358                 payload = frame->data;
1359                 ethertype = (payload[6] << 8) | payload[7];
1360
1361                 if (likely((compare_ether_addr(payload, rfc1042_header) == 0 &&
1362                             ethertype != ETH_P_AARP && ethertype != ETH_P_IPX) ||
1363                            compare_ether_addr(payload,
1364                                               bridge_tunnel_header) == 0)) {
1365                         /* remove RFC1042 or Bridge-Tunnel
1366                          * encapsulation and replace EtherType */
1367                         skb_pull(frame, 6);
1368                         memcpy(skb_push(frame, ETH_ALEN), src, ETH_ALEN);
1369                         memcpy(skb_push(frame, ETH_ALEN), dst, ETH_ALEN);
1370                 } else {
1371                         memcpy(skb_push(frame, sizeof(__be16)),
1372                                &len, sizeof(__be16));
1373                         memcpy(skb_push(frame, ETH_ALEN), src, ETH_ALEN);
1374                         memcpy(skb_push(frame, ETH_ALEN), dst, ETH_ALEN);
1375                 }
1376
1377                 if (!ieee80211_frame_allowed(rx)) {
1378                         if (skb == frame) /* last frame */
1379                                 return RX_DROP_UNUSABLE;
1380                         dev_kfree_skb(frame);
1381                         continue;
1382                 }
1383
1384                 ieee80211_deliver_skb(rx);
1385         }
1386
1387         return RX_QUEUED;
1388 }
1389
1390 static ieee80211_rx_result debug_noinline
1391 ieee80211_rx_h_mesh_fwding(struct ieee80211_rx_data *rx)
1392 {
1393         struct ieee80211_hdr *hdr;
1394         struct ieee80211s_hdr *mesh_hdr;
1395         unsigned int hdrlen;
1396         struct sk_buff *skb = rx->skb, *fwd_skb;
1397
1398         hdr = (struct ieee80211_hdr *) skb->data;
1399         hdrlen = ieee80211_hdrlen(hdr->frame_control);
1400         mesh_hdr = (struct ieee80211s_hdr *) (skb->data + hdrlen);
1401
1402         if (!ieee80211_is_data(hdr->frame_control))
1403                 return RX_CONTINUE;
1404
1405         if (!mesh_hdr->ttl)
1406                 /* illegal frame */
1407                 return RX_DROP_MONITOR;
1408
1409         if (compare_ether_addr(rx->dev->dev_addr, hdr->addr3) == 0)
1410                 return RX_CONTINUE;
1411
1412         mesh_hdr->ttl--;
1413
1414         if (rx->flags & IEEE80211_RX_RA_MATCH) {
1415                 if (!mesh_hdr->ttl)
1416                         IEEE80211_IFSTA_MESH_CTR_INC(&rx->sdata->u.sta,
1417                                                      dropped_frames_ttl);
1418                 else {
1419                         struct ieee80211_hdr *fwd_hdr;
1420                         fwd_skb = skb_copy(skb, GFP_ATOMIC);
1421
1422                         if (!fwd_skb && net_ratelimit())
1423                                 printk(KERN_DEBUG "%s: failed to clone mesh frame\n",
1424                                                    rx->dev->name);
1425
1426                         fwd_hdr =  (struct ieee80211_hdr *) fwd_skb->data;
1427                         /*
1428                          * Save TA to addr1 to send TA a path error if a
1429                          * suitable next hop is not found
1430                          */
1431                         memcpy(fwd_hdr->addr1, fwd_hdr->addr2, ETH_ALEN);
1432                         memcpy(fwd_hdr->addr2, rx->dev->dev_addr, ETH_ALEN);
1433                         fwd_skb->dev = rx->local->mdev;
1434                         fwd_skb->iif = rx->dev->ifindex;
1435                         dev_queue_xmit(fwd_skb);
1436                 }
1437         }
1438
1439         if (is_multicast_ether_addr(hdr->addr3) ||
1440             rx->dev->flags & IFF_PROMISC)
1441                 return RX_CONTINUE;
1442         else
1443                 return RX_DROP_MONITOR;
1444 }
1445
1446
1447 static ieee80211_rx_result debug_noinline
1448 ieee80211_rx_h_data(struct ieee80211_rx_data *rx)
1449 {
1450         struct net_device *dev = rx->dev;
1451         u16 fc;
1452         int err;
1453
1454         fc = rx->fc;
1455         if (unlikely((fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_DATA))
1456                 return RX_CONTINUE;
1457
1458         if (unlikely(!WLAN_FC_DATA_PRESENT(fc)))
1459                 return RX_DROP_MONITOR;
1460
1461         err = ieee80211_data_to_8023(rx);
1462         if (unlikely(err))
1463                 return RX_DROP_UNUSABLE;
1464
1465         if (!ieee80211_frame_allowed(rx))
1466                 return RX_DROP_MONITOR;
1467
1468         rx->skb->dev = dev;
1469
1470         dev->stats.rx_packets++;
1471         dev->stats.rx_bytes += rx->skb->len;
1472
1473         ieee80211_deliver_skb(rx);
1474
1475         return RX_QUEUED;
1476 }
1477
1478 static ieee80211_rx_result debug_noinline
1479 ieee80211_rx_h_ctrl(struct ieee80211_rx_data *rx)
1480 {
1481         struct ieee80211_local *local = rx->local;
1482         struct ieee80211_hw *hw = &local->hw;
1483         struct sk_buff *skb = rx->skb;
1484         struct ieee80211_bar *bar = (struct ieee80211_bar *)skb->data;
1485         struct tid_ampdu_rx *tid_agg_rx;
1486         u16 start_seq_num;
1487         u16 tid;
1488
1489         if (likely(!ieee80211_is_ctl(bar->frame_control)))
1490                 return RX_CONTINUE;
1491
1492         if (ieee80211_is_back_req(bar->frame_control)) {
1493                 if (!rx->sta)
1494                         return RX_CONTINUE;
1495                 tid = le16_to_cpu(bar->control) >> 12;
1496                 if (rx->sta->ampdu_mlme.tid_state_rx[tid]
1497                                         != HT_AGG_STATE_OPERATIONAL)
1498                         return RX_CONTINUE;
1499                 tid_agg_rx = rx->sta->ampdu_mlme.tid_rx[tid];
1500
1501                 start_seq_num = le16_to_cpu(bar->start_seq_num) >> 4;
1502
1503                 /* reset session timer */
1504                 if (tid_agg_rx->timeout) {
1505                         unsigned long expires =
1506                                 jiffies + (tid_agg_rx->timeout / 1000) * HZ;
1507                         mod_timer(&tid_agg_rx->session_timer, expires);
1508                 }
1509
1510                 /* manage reordering buffer according to requested */
1511                 /* sequence number */
1512                 rcu_read_lock();
1513                 ieee80211_sta_manage_reorder_buf(hw, tid_agg_rx, NULL,
1514                                                  start_seq_num, 1);
1515                 rcu_read_unlock();
1516                 return RX_DROP_UNUSABLE;
1517         }
1518
1519         return RX_CONTINUE;
1520 }
1521
1522 static ieee80211_rx_result debug_noinline
1523 ieee80211_rx_h_mgmt(struct ieee80211_rx_data *rx)
1524 {
1525         struct ieee80211_sub_if_data *sdata;
1526
1527         if (!(rx->flags & IEEE80211_RX_RA_MATCH))
1528                 return RX_DROP_MONITOR;
1529
1530         sdata = IEEE80211_DEV_TO_SUB_IF(rx->dev);
1531         if ((sdata->vif.type == IEEE80211_IF_TYPE_STA ||
1532              sdata->vif.type == IEEE80211_IF_TYPE_IBSS ||
1533              sdata->vif.type == IEEE80211_IF_TYPE_MESH_POINT) &&
1534             !(sdata->flags & IEEE80211_SDATA_USERSPACE_MLME))
1535                 ieee80211_sta_rx_mgmt(rx->dev, rx->skb, rx->status);
1536         else
1537                 return RX_DROP_MONITOR;
1538
1539         return RX_QUEUED;
1540 }
1541
1542 static void ieee80211_rx_michael_mic_report(struct net_device *dev,
1543                                             struct ieee80211_hdr *hdr,
1544                                             struct ieee80211_rx_data *rx)
1545 {
1546         int keyidx;
1547         unsigned int hdrlen;
1548         DECLARE_MAC_BUF(mac);
1549         DECLARE_MAC_BUF(mac2);
1550
1551         hdrlen = ieee80211_hdrlen(hdr->frame_control);
1552         if (rx->skb->len >= hdrlen + 4)
1553                 keyidx = rx->skb->data[hdrlen + 3] >> 6;
1554         else
1555                 keyidx = -1;
1556
1557         if (!rx->sta) {
1558                 /*
1559                  * Some hardware seem to generate incorrect Michael MIC
1560                  * reports; ignore them to avoid triggering countermeasures.
1561                  */
1562                 goto ignore;
1563         }
1564
1565         if (!ieee80211_has_protected(hdr->frame_control))
1566                 goto ignore;
1567
1568         if (rx->sdata->vif.type == IEEE80211_IF_TYPE_AP && keyidx) {
1569                 /*
1570                  * APs with pairwise keys should never receive Michael MIC
1571                  * errors for non-zero keyidx because these are reserved for
1572                  * group keys and only the AP is sending real multicast
1573                  * frames in the BSS.
1574                  */
1575                 goto ignore;
1576         }
1577
1578         if (!ieee80211_is_data(hdr->frame_control) &&
1579             !ieee80211_is_auth(hdr->frame_control))
1580                 goto ignore;
1581
1582         mac80211_ev_michael_mic_failure(rx->dev, keyidx, hdr);
1583  ignore:
1584         dev_kfree_skb(rx->skb);
1585         rx->skb = NULL;
1586 }
1587
1588 /* TODO: use IEEE80211_RX_FRAGMENTED */
1589 static void ieee80211_rx_cooked_monitor(struct ieee80211_rx_data *rx)
1590 {
1591         struct ieee80211_sub_if_data *sdata;
1592         struct ieee80211_local *local = rx->local;
1593         struct ieee80211_rtap_hdr {
1594                 struct ieee80211_radiotap_header hdr;
1595                 u8 flags;
1596                 u8 rate;
1597                 __le16 chan_freq;
1598                 __le16 chan_flags;
1599         } __attribute__ ((packed)) *rthdr;
1600         struct sk_buff *skb = rx->skb, *skb2;
1601         struct net_device *prev_dev = NULL;
1602         struct ieee80211_rx_status *status = rx->status;
1603
1604         if (rx->flags & IEEE80211_RX_CMNTR_REPORTED)
1605                 goto out_free_skb;
1606
1607         if (skb_headroom(skb) < sizeof(*rthdr) &&
1608             pskb_expand_head(skb, sizeof(*rthdr), 0, GFP_ATOMIC))
1609                 goto out_free_skb;
1610
1611         rthdr = (void *)skb_push(skb, sizeof(*rthdr));
1612         memset(rthdr, 0, sizeof(*rthdr));
1613         rthdr->hdr.it_len = cpu_to_le16(sizeof(*rthdr));
1614         rthdr->hdr.it_present =
1615                 cpu_to_le32((1 << IEEE80211_RADIOTAP_FLAGS) |
1616                             (1 << IEEE80211_RADIOTAP_RATE) |
1617                             (1 << IEEE80211_RADIOTAP_CHANNEL));
1618
1619         rthdr->rate = rx->rate->bitrate / 5;
1620         rthdr->chan_freq = cpu_to_le16(status->freq);
1621
1622         if (status->band == IEEE80211_BAND_5GHZ)
1623                 rthdr->chan_flags = cpu_to_le16(IEEE80211_CHAN_OFDM |
1624                                                 IEEE80211_CHAN_5GHZ);
1625         else
1626                 rthdr->chan_flags = cpu_to_le16(IEEE80211_CHAN_DYN |
1627                                                 IEEE80211_CHAN_2GHZ);
1628
1629         skb_set_mac_header(skb, 0);
1630         skb->ip_summed = CHECKSUM_UNNECESSARY;
1631         skb->pkt_type = PACKET_OTHERHOST;
1632         skb->protocol = htons(ETH_P_802_2);
1633
1634         list_for_each_entry_rcu(sdata, &local->interfaces, list) {
1635                 if (!netif_running(sdata->dev))
1636                         continue;
1637
1638                 if (sdata->vif.type != IEEE80211_IF_TYPE_MNTR ||
1639                     !(sdata->u.mntr_flags & MONITOR_FLAG_COOK_FRAMES))
1640                         continue;
1641
1642                 if (prev_dev) {
1643                         skb2 = skb_clone(skb, GFP_ATOMIC);
1644                         if (skb2) {
1645                                 skb2->dev = prev_dev;
1646                                 netif_rx(skb2);
1647                         }
1648                 }
1649
1650                 prev_dev = sdata->dev;
1651                 sdata->dev->stats.rx_packets++;
1652                 sdata->dev->stats.rx_bytes += skb->len;
1653         }
1654
1655         if (prev_dev) {
1656                 skb->dev = prev_dev;
1657                 netif_rx(skb);
1658                 skb = NULL;
1659         } else
1660                 goto out_free_skb;
1661
1662         rx->flags |= IEEE80211_RX_CMNTR_REPORTED;
1663         return;
1664
1665  out_free_skb:
1666         dev_kfree_skb(skb);
1667 }
1668
1669
1670 static void ieee80211_invoke_rx_handlers(struct ieee80211_sub_if_data *sdata,
1671                                          struct ieee80211_rx_data *rx,
1672                                          struct sk_buff *skb)
1673 {
1674         ieee80211_rx_result res = RX_DROP_MONITOR;
1675
1676         rx->skb = skb;
1677         rx->sdata = sdata;
1678         rx->dev = sdata->dev;
1679
1680 #define CALL_RXH(rxh)                   \
1681         do {                            \
1682                 res = rxh(rx);          \
1683                 if (res != RX_CONTINUE) \
1684                         goto rxh_done;  \
1685         } while (0);
1686
1687         CALL_RXH(ieee80211_rx_h_passive_scan)
1688         CALL_RXH(ieee80211_rx_h_check)
1689         CALL_RXH(ieee80211_rx_h_decrypt)
1690         CALL_RXH(ieee80211_rx_h_sta_process)
1691         CALL_RXH(ieee80211_rx_h_defragment)
1692         CALL_RXH(ieee80211_rx_h_ps_poll)
1693         CALL_RXH(ieee80211_rx_h_michael_mic_verify)
1694         /* must be after MMIC verify so header is counted in MPDU mic */
1695         CALL_RXH(ieee80211_rx_h_remove_qos_control)
1696         CALL_RXH(ieee80211_rx_h_amsdu)
1697         if (ieee80211_vif_is_mesh(&sdata->vif))
1698                 CALL_RXH(ieee80211_rx_h_mesh_fwding);
1699         CALL_RXH(ieee80211_rx_h_data)
1700         CALL_RXH(ieee80211_rx_h_ctrl)
1701         CALL_RXH(ieee80211_rx_h_mgmt)
1702
1703 #undef CALL_RXH
1704
1705  rxh_done:
1706         switch (res) {
1707         case RX_DROP_MONITOR:
1708                 I802_DEBUG_INC(sdata->local->rx_handlers_drop);
1709                 if (rx->sta)
1710                         rx->sta->rx_dropped++;
1711                 /* fall through */
1712         case RX_CONTINUE:
1713                 ieee80211_rx_cooked_monitor(rx);
1714                 break;
1715         case RX_DROP_UNUSABLE:
1716                 I802_DEBUG_INC(sdata->local->rx_handlers_drop);
1717                 if (rx->sta)
1718                         rx->sta->rx_dropped++;
1719                 dev_kfree_skb(rx->skb);
1720                 break;
1721         case RX_QUEUED:
1722                 I802_DEBUG_INC(sdata->local->rx_handlers_queued);
1723                 break;
1724         }
1725 }
1726
1727 /* main receive path */
1728
1729 static int prepare_for_handlers(struct ieee80211_sub_if_data *sdata,
1730                                 u8 *bssid, struct ieee80211_rx_data *rx,
1731                                 struct ieee80211_hdr *hdr)
1732 {
1733         int multicast = is_multicast_ether_addr(hdr->addr1);
1734
1735         switch (sdata->vif.type) {
1736         case IEEE80211_IF_TYPE_STA:
1737                 if (!bssid)
1738                         return 0;
1739                 if (!ieee80211_bssid_match(bssid, sdata->u.sta.bssid)) {
1740                         if (!(rx->flags & IEEE80211_RX_IN_SCAN))
1741                                 return 0;
1742                         rx->flags &= ~IEEE80211_RX_RA_MATCH;
1743                 } else if (!multicast &&
1744                            compare_ether_addr(sdata->dev->dev_addr,
1745                                               hdr->addr1) != 0) {
1746                         if (!(sdata->dev->flags & IFF_PROMISC))
1747                                 return 0;
1748                         rx->flags &= ~IEEE80211_RX_RA_MATCH;
1749                 }
1750                 break;
1751         case IEEE80211_IF_TYPE_IBSS:
1752                 if (!bssid)
1753                         return 0;
1754                 if (ieee80211_is_beacon(hdr->frame_control)) {
1755                         if (!rx->sta)
1756                                 rx->sta = ieee80211_ibss_add_sta(sdata->dev,
1757                                                 rx->skb, bssid, hdr->addr2,
1758                                                 BIT(rx->status->rate_idx));
1759                         return 1;
1760                 }
1761                 else if (!ieee80211_bssid_match(bssid, sdata->u.sta.bssid)) {
1762                         if (!(rx->flags & IEEE80211_RX_IN_SCAN))
1763                                 return 0;
1764                         rx->flags &= ~IEEE80211_RX_RA_MATCH;
1765                 } else if (!multicast &&
1766                            compare_ether_addr(sdata->dev->dev_addr,
1767                                               hdr->addr1) != 0) {
1768                         if (!(sdata->dev->flags & IFF_PROMISC))
1769                                 return 0;
1770                         rx->flags &= ~IEEE80211_RX_RA_MATCH;
1771                 } else if (!rx->sta)
1772                         rx->sta = ieee80211_ibss_add_sta(sdata->dev, rx->skb,
1773                                                 bssid, hdr->addr2,
1774                                                 BIT(rx->status->rate_idx));
1775                 break;
1776         case IEEE80211_IF_TYPE_MESH_POINT:
1777                 if (!multicast &&
1778                     compare_ether_addr(sdata->dev->dev_addr,
1779                                        hdr->addr1) != 0) {
1780                         if (!(sdata->dev->flags & IFF_PROMISC))
1781                                 return 0;
1782
1783                         rx->flags &= ~IEEE80211_RX_RA_MATCH;
1784                 }
1785                 break;
1786         case IEEE80211_IF_TYPE_VLAN:
1787         case IEEE80211_IF_TYPE_AP:
1788                 if (!bssid) {
1789                         if (compare_ether_addr(sdata->dev->dev_addr,
1790                                                hdr->addr1))
1791                                 return 0;
1792                 } else if (!ieee80211_bssid_match(bssid,
1793                                         sdata->dev->dev_addr)) {
1794                         if (!(rx->flags & IEEE80211_RX_IN_SCAN))
1795                                 return 0;
1796                         rx->flags &= ~IEEE80211_RX_RA_MATCH;
1797                 }
1798                 break;
1799         case IEEE80211_IF_TYPE_WDS:
1800                 if (bssid || !ieee80211_is_data(hdr->frame_control))
1801                         return 0;
1802                 if (compare_ether_addr(sdata->u.wds.remote_addr, hdr->addr2))
1803                         return 0;
1804                 break;
1805         case IEEE80211_IF_TYPE_MNTR:
1806                 /* take everything */
1807                 break;
1808         case IEEE80211_IF_TYPE_INVALID:
1809                 /* should never get here */
1810                 WARN_ON(1);
1811                 break;
1812         }
1813
1814         return 1;
1815 }
1816
1817 /*
1818  * This is the actual Rx frames handler. as it blongs to Rx path it must
1819  * be called with rcu_read_lock protection.
1820  */
1821 static void __ieee80211_rx_handle_packet(struct ieee80211_hw *hw,
1822                                          struct sk_buff *skb,
1823                                          struct ieee80211_rx_status *status,
1824                                          struct ieee80211_rate *rate)
1825 {
1826         struct ieee80211_local *local = hw_to_local(hw);
1827         struct ieee80211_sub_if_data *sdata;
1828         struct ieee80211_hdr *hdr;
1829         struct ieee80211_rx_data rx;
1830         u16 type;
1831         int prepares;
1832         struct ieee80211_sub_if_data *prev = NULL;
1833         struct sk_buff *skb_new;
1834         u8 *bssid;
1835
1836         hdr = (struct ieee80211_hdr *) skb->data;
1837         memset(&rx, 0, sizeof(rx));
1838         rx.skb = skb;
1839         rx.local = local;
1840
1841         rx.status = status;
1842         rx.rate = rate;
1843         rx.fc = le16_to_cpu(hdr->frame_control);
1844         type = rx.fc & IEEE80211_FCTL_FTYPE;
1845
1846         if (type == IEEE80211_FTYPE_DATA || type == IEEE80211_FTYPE_MGMT)
1847                 local->dot11ReceivedFragmentCount++;
1848
1849         rx.sta = sta_info_get(local, hdr->addr2);
1850         if (rx.sta) {
1851                 rx.sdata = rx.sta->sdata;
1852                 rx.dev = rx.sta->sdata->dev;
1853         }
1854
1855         if ((status->flag & RX_FLAG_MMIC_ERROR)) {
1856                 ieee80211_rx_michael_mic_report(local->mdev, hdr, &rx);
1857                 return;
1858         }
1859
1860         if (unlikely(local->sta_sw_scanning || local->sta_hw_scanning))
1861                 rx.flags |= IEEE80211_RX_IN_SCAN;
1862
1863         ieee80211_parse_qos(&rx);
1864         ieee80211_verify_ip_alignment(&rx);
1865
1866         skb = rx.skb;
1867
1868         list_for_each_entry_rcu(sdata, &local->interfaces, list) {
1869                 if (!netif_running(sdata->dev))
1870                         continue;
1871
1872                 if (sdata->vif.type == IEEE80211_IF_TYPE_MNTR)
1873                         continue;
1874
1875                 bssid = ieee80211_get_bssid(hdr, skb->len, sdata->vif.type);
1876                 rx.flags |= IEEE80211_RX_RA_MATCH;
1877                 prepares = prepare_for_handlers(sdata, bssid, &rx, hdr);
1878
1879                 if (!prepares)
1880                         continue;
1881
1882                 /*
1883                  * frame is destined for this interface, but if it's not
1884                  * also for the previous one we handle that after the
1885                  * loop to avoid copying the SKB once too much
1886                  */
1887
1888                 if (!prev) {
1889                         prev = sdata;
1890                         continue;
1891                 }
1892
1893                 /*
1894                  * frame was destined for the previous interface
1895                  * so invoke RX handlers for it
1896                  */
1897
1898                 skb_new = skb_copy(skb, GFP_ATOMIC);
1899                 if (!skb_new) {
1900                         if (net_ratelimit())
1901                                 printk(KERN_DEBUG "%s: failed to copy "
1902                                        "multicast frame for %s\n",
1903                                        wiphy_name(local->hw.wiphy),
1904                                        prev->dev->name);
1905                         continue;
1906                 }
1907                 rx.fc = le16_to_cpu(hdr->frame_control);
1908                 ieee80211_invoke_rx_handlers(prev, &rx, skb_new);
1909                 prev = sdata;
1910         }
1911         if (prev) {
1912                 rx.fc = le16_to_cpu(hdr->frame_control);
1913                 ieee80211_invoke_rx_handlers(prev, &rx, skb);
1914         } else
1915                 dev_kfree_skb(skb);
1916 }
1917
1918 #define SEQ_MODULO 0x1000
1919 #define SEQ_MASK   0xfff
1920
1921 static inline int seq_less(u16 sq1, u16 sq2)
1922 {
1923         return (((sq1 - sq2) & SEQ_MASK) > (SEQ_MODULO >> 1));
1924 }
1925
1926 static inline u16 seq_inc(u16 sq)
1927 {
1928         return ((sq + 1) & SEQ_MASK);
1929 }
1930
1931 static inline u16 seq_sub(u16 sq1, u16 sq2)
1932 {
1933         return ((sq1 - sq2) & SEQ_MASK);
1934 }
1935
1936
1937 /*
1938  * As it function blongs to Rx path it must be called with
1939  * the proper rcu_read_lock protection for its flow.
1940  */
1941 u8 ieee80211_sta_manage_reorder_buf(struct ieee80211_hw *hw,
1942                                 struct tid_ampdu_rx *tid_agg_rx,
1943                                 struct sk_buff *skb, u16 mpdu_seq_num,
1944                                 int bar_req)
1945 {
1946         struct ieee80211_local *local = hw_to_local(hw);
1947         struct ieee80211_rx_status status;
1948         u16 head_seq_num, buf_size;
1949         int index;
1950         struct ieee80211_supported_band *sband;
1951         struct ieee80211_rate *rate;
1952
1953         buf_size = tid_agg_rx->buf_size;
1954         head_seq_num = tid_agg_rx->head_seq_num;
1955
1956         /* frame with out of date sequence number */
1957         if (seq_less(mpdu_seq_num, head_seq_num)) {
1958                 dev_kfree_skb(skb);
1959                 return 1;
1960         }
1961
1962         /* if frame sequence number exceeds our buffering window size or
1963          * block Ack Request arrived - release stored frames */
1964         if ((!seq_less(mpdu_seq_num, head_seq_num + buf_size)) || (bar_req)) {
1965                 /* new head to the ordering buffer */
1966                 if (bar_req)
1967                         head_seq_num = mpdu_seq_num;
1968                 else
1969                         head_seq_num =
1970                                 seq_inc(seq_sub(mpdu_seq_num, buf_size));
1971                 /* release stored frames up to new head to stack */
1972                 while (seq_less(tid_agg_rx->head_seq_num, head_seq_num)) {
1973                         index = seq_sub(tid_agg_rx->head_seq_num,
1974                                 tid_agg_rx->ssn)
1975                                 % tid_agg_rx->buf_size;
1976
1977                         if (tid_agg_rx->reorder_buf[index]) {
1978                                 /* release the reordered frames to stack */
1979                                 memcpy(&status,
1980                                         tid_agg_rx->reorder_buf[index]->cb,
1981                                         sizeof(status));
1982                                 sband = local->hw.wiphy->bands[status.band];
1983                                 rate = &sband->bitrates[status.rate_idx];
1984                                 __ieee80211_rx_handle_packet(hw,
1985                                         tid_agg_rx->reorder_buf[index],
1986                                         &status, rate);
1987                                 tid_agg_rx->stored_mpdu_num--;
1988                                 tid_agg_rx->reorder_buf[index] = NULL;
1989                         }
1990                         tid_agg_rx->head_seq_num =
1991                                 seq_inc(tid_agg_rx->head_seq_num);
1992                 }
1993                 if (bar_req)
1994                         return 1;
1995         }
1996
1997         /* now the new frame is always in the range of the reordering */
1998         /* buffer window */
1999         index = seq_sub(mpdu_seq_num, tid_agg_rx->ssn)
2000                                 % tid_agg_rx->buf_size;
2001         /* check if we already stored this frame */
2002         if (tid_agg_rx->reorder_buf[index]) {
2003                 dev_kfree_skb(skb);
2004                 return 1;
2005         }
2006
2007         /* if arrived mpdu is in the right order and nothing else stored */
2008         /* release it immediately */
2009         if (mpdu_seq_num == tid_agg_rx->head_seq_num &&
2010                         tid_agg_rx->stored_mpdu_num == 0) {
2011                 tid_agg_rx->head_seq_num =
2012                         seq_inc(tid_agg_rx->head_seq_num);
2013                 return 0;
2014         }
2015
2016         /* put the frame in the reordering buffer */
2017         tid_agg_rx->reorder_buf[index] = skb;
2018         tid_agg_rx->stored_mpdu_num++;
2019         /* release the buffer until next missing frame */
2020         index = seq_sub(tid_agg_rx->head_seq_num, tid_agg_rx->ssn)
2021                                                 % tid_agg_rx->buf_size;
2022         while (tid_agg_rx->reorder_buf[index]) {
2023                 /* release the reordered frame back to stack */
2024                 memcpy(&status, tid_agg_rx->reorder_buf[index]->cb,
2025                         sizeof(status));
2026                 sband = local->hw.wiphy->bands[status.band];
2027                 rate = &sband->bitrates[status.rate_idx];
2028                 __ieee80211_rx_handle_packet(hw, tid_agg_rx->reorder_buf[index],
2029                                              &status, rate);
2030                 tid_agg_rx->stored_mpdu_num--;
2031                 tid_agg_rx->reorder_buf[index] = NULL;
2032                 tid_agg_rx->head_seq_num = seq_inc(tid_agg_rx->head_seq_num);
2033                 index = seq_sub(tid_agg_rx->head_seq_num,
2034                         tid_agg_rx->ssn) % tid_agg_rx->buf_size;
2035         }
2036         return 1;
2037 }
2038
2039 static u8 ieee80211_rx_reorder_ampdu(struct ieee80211_local *local,
2040                                      struct sk_buff *skb)
2041 {
2042         struct ieee80211_hw *hw = &local->hw;
2043         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
2044         struct sta_info *sta;
2045         struct tid_ampdu_rx *tid_agg_rx;
2046         u16 sc;
2047         u16 mpdu_seq_num;
2048         u8 ret = 0;
2049         int tid;
2050
2051         sta = sta_info_get(local, hdr->addr2);
2052         if (!sta)
2053                 return ret;
2054
2055         /* filter the QoS data rx stream according to
2056          * STA/TID and check if this STA/TID is on aggregation */
2057         if (!ieee80211_is_data_qos(hdr->frame_control))
2058                 goto end_reorder;
2059
2060         tid = *ieee80211_get_qos_ctl(hdr) & IEEE80211_QOS_CTL_TID_MASK;
2061
2062         if (sta->ampdu_mlme.tid_state_rx[tid] != HT_AGG_STATE_OPERATIONAL)
2063                 goto end_reorder;
2064
2065         tid_agg_rx = sta->ampdu_mlme.tid_rx[tid];
2066
2067         /* qos null data frames are excluded */
2068         if (unlikely(hdr->frame_control & cpu_to_le16(IEEE80211_STYPE_NULLFUNC)))
2069                 goto end_reorder;
2070
2071         /* new un-ordered ampdu frame - process it */
2072
2073         /* reset session timer */
2074         if (tid_agg_rx->timeout) {
2075                 unsigned long expires =
2076                         jiffies + (tid_agg_rx->timeout / 1000) * HZ;
2077                 mod_timer(&tid_agg_rx->session_timer, expires);
2078         }
2079
2080         /* if this mpdu is fragmented - terminate rx aggregation session */
2081         sc = le16_to_cpu(hdr->seq_ctrl);
2082         if (sc & IEEE80211_SCTL_FRAG) {
2083                 ieee80211_sta_stop_rx_ba_session(sta->sdata->dev, sta->addr,
2084                         tid, 0, WLAN_REASON_QSTA_REQUIRE_SETUP);
2085                 ret = 1;
2086                 goto end_reorder;
2087         }
2088
2089         /* according to mpdu sequence number deal with reordering buffer */
2090         mpdu_seq_num = (sc & IEEE80211_SCTL_SEQ) >> 4;
2091         ret = ieee80211_sta_manage_reorder_buf(hw, tid_agg_rx, skb,
2092                                                 mpdu_seq_num, 0);
2093  end_reorder:
2094         return ret;
2095 }
2096
2097 /*
2098  * This is the receive path handler. It is called by a low level driver when an
2099  * 802.11 MPDU is received from the hardware.
2100  */
2101 void __ieee80211_rx(struct ieee80211_hw *hw, struct sk_buff *skb,
2102                     struct ieee80211_rx_status *status)
2103 {
2104         struct ieee80211_local *local = hw_to_local(hw);
2105         struct ieee80211_rate *rate = NULL;
2106         struct ieee80211_supported_band *sband;
2107
2108         if (status->band < 0 ||
2109             status->band >= IEEE80211_NUM_BANDS) {
2110                 WARN_ON(1);
2111                 return;
2112         }
2113
2114         sband = local->hw.wiphy->bands[status->band];
2115
2116         if (!sband ||
2117             status->rate_idx < 0 ||
2118             status->rate_idx >= sband->n_bitrates) {
2119                 WARN_ON(1);
2120                 return;
2121         }
2122
2123         rate = &sband->bitrates[status->rate_idx];
2124
2125         /*
2126          * key references and virtual interfaces are protected using RCU
2127          * and this requires that we are in a read-side RCU section during
2128          * receive processing
2129          */
2130         rcu_read_lock();
2131
2132         /*
2133          * Frames with failed FCS/PLCP checksum are not returned,
2134          * all other frames are returned without radiotap header
2135          * if it was previously present.
2136          * Also, frames with less than 16 bytes are dropped.
2137          */
2138         skb = ieee80211_rx_monitor(local, skb, status, rate);
2139         if (!skb) {
2140                 rcu_read_unlock();
2141                 return;
2142         }
2143
2144         if (!ieee80211_rx_reorder_ampdu(local, skb))
2145                 __ieee80211_rx_handle_packet(hw, skb, status, rate);
2146
2147         rcu_read_unlock();
2148 }
2149 EXPORT_SYMBOL(__ieee80211_rx);
2150
2151 /* This is a version of the rx handler that can be called from hard irq
2152  * context. Post the skb on the queue and schedule the tasklet */
2153 void ieee80211_rx_irqsafe(struct ieee80211_hw *hw, struct sk_buff *skb,
2154                           struct ieee80211_rx_status *status)
2155 {
2156         struct ieee80211_local *local = hw_to_local(hw);
2157
2158         BUILD_BUG_ON(sizeof(struct ieee80211_rx_status) > sizeof(skb->cb));
2159
2160         skb->dev = local->mdev;
2161         /* copy status into skb->cb for use by tasklet */
2162         memcpy(skb->cb, status, sizeof(*status));
2163         skb->pkt_type = IEEE80211_RX_MSG;
2164         skb_queue_tail(&local->skb_queue, skb);
2165         tasklet_schedule(&local->tasklet);
2166 }
2167 EXPORT_SYMBOL(ieee80211_rx_irqsafe);