Merge branch 'linux-2.6'
[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/kernel.h>
13 #include <linux/skbuff.h>
14 #include <linux/netdevice.h>
15 #include <linux/etherdevice.h>
16 #include <linux/rcupdate.h>
17 #include <net/mac80211.h>
18 #include <net/ieee80211_radiotap.h>
19
20 #include "ieee80211_i.h"
21 #include "ieee80211_led.h"
22 #include "wep.h"
23 #include "wpa.h"
24 #include "tkip.h"
25 #include "wme.h"
26
27 u8 ieee80211_sta_manage_reorder_buf(struct ieee80211_hw *hw,
28                                 struct tid_ampdu_rx *tid_agg_rx,
29                                 struct sk_buff *skb, u16 mpdu_seq_num,
30                                 int bar_req);
31 /*
32  * monitor mode reception
33  *
34  * This function cleans up the SKB, i.e. it removes all the stuff
35  * only useful for monitoring.
36  */
37 static struct sk_buff *remove_monitor_info(struct ieee80211_local *local,
38                                            struct sk_buff *skb,
39                                            int rtap_len)
40 {
41         skb_pull(skb, rtap_len);
42
43         if (local->hw.flags & IEEE80211_HW_RX_INCLUDES_FCS) {
44                 if (likely(skb->len > FCS_LEN))
45                         skb_trim(skb, skb->len - FCS_LEN);
46                 else {
47                         /* driver bug */
48                         WARN_ON(1);
49                         dev_kfree_skb(skb);
50                         skb = NULL;
51                 }
52         }
53
54         return skb;
55 }
56
57 static inline int should_drop_frame(struct ieee80211_rx_status *status,
58                                     struct sk_buff *skb,
59                                     int present_fcs_len,
60                                     int radiotap_len)
61 {
62         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
63
64         if (status->flag & (RX_FLAG_FAILED_FCS_CRC | RX_FLAG_FAILED_PLCP_CRC))
65                 return 1;
66         if (unlikely(skb->len < 16 + present_fcs_len + radiotap_len))
67                 return 1;
68         if (((hdr->frame_control & cpu_to_le16(IEEE80211_FCTL_FTYPE)) ==
69                         cpu_to_le16(IEEE80211_FTYPE_CTL)) &&
70             ((hdr->frame_control & cpu_to_le16(IEEE80211_FCTL_STYPE)) !=
71                         cpu_to_le16(IEEE80211_STYPE_PSPOLL)) &&
72             ((hdr->frame_control & cpu_to_le16(IEEE80211_FCTL_STYPE)) !=
73                         cpu_to_le16(IEEE80211_STYPE_BACK_REQ)))
74                 return 1;
75         return 0;
76 }
77
78 /*
79  * This function copies a received frame to all monitor interfaces and
80  * returns a cleaned-up SKB that no longer includes the FCS nor the
81  * radiotap header the driver might have added.
82  */
83 static struct sk_buff *
84 ieee80211_rx_monitor(struct ieee80211_local *local, struct sk_buff *origskb,
85                      struct ieee80211_rx_status *status)
86 {
87         struct ieee80211_sub_if_data *sdata;
88         struct ieee80211_rate *rate;
89         int needed_headroom = 0;
90         struct ieee80211_radiotap_header *rthdr;
91         __le64 *rttsft = NULL;
92         struct ieee80211_rtap_fixed_data {
93                 u8 flags;
94                 u8 rate;
95                 __le16 chan_freq;
96                 __le16 chan_flags;
97                 u8 antsignal;
98                 u8 padding_for_rxflags;
99                 __le16 rx_flags;
100         } __attribute__ ((packed)) *rtfixed;
101         struct sk_buff *skb, *skb2;
102         struct net_device *prev_dev = NULL;
103         int present_fcs_len = 0;
104         int rtap_len = 0;
105
106         /*
107          * First, we may need to make a copy of the skb because
108          *  (1) we need to modify it for radiotap (if not present), and
109          *  (2) the other RX handlers will modify the skb we got.
110          *
111          * We don't need to, of course, if we aren't going to return
112          * the SKB because it has a bad FCS/PLCP checksum.
113          */
114         if (status->flag & RX_FLAG_RADIOTAP)
115                 rtap_len = ieee80211_get_radiotap_len(origskb->data);
116         else
117                 /* room for radiotap header, always present fields and TSFT */
118                 needed_headroom = sizeof(*rthdr) + sizeof(*rtfixed) + 8;
119
120         if (local->hw.flags & IEEE80211_HW_RX_INCLUDES_FCS)
121                 present_fcs_len = FCS_LEN;
122
123         if (!local->monitors) {
124                 if (should_drop_frame(status, origskb, present_fcs_len,
125                                       rtap_len)) {
126                         dev_kfree_skb(origskb);
127                         return NULL;
128                 }
129
130                 return remove_monitor_info(local, origskb, rtap_len);
131         }
132
133         if (should_drop_frame(status, origskb, present_fcs_len, rtap_len)) {
134                 /* only need to expand headroom if necessary */
135                 skb = origskb;
136                 origskb = NULL;
137
138                 /*
139                  * This shouldn't trigger often because most devices have an
140                  * RX header they pull before we get here, and that should
141                  * be big enough for our radiotap information. We should
142                  * probably export the length to drivers so that we can have
143                  * them allocate enough headroom to start with.
144                  */
145                 if (skb_headroom(skb) < needed_headroom &&
146                     pskb_expand_head(skb, needed_headroom, 0, GFP_ATOMIC)) {
147                         dev_kfree_skb(skb);
148                         return NULL;
149                 }
150         } else {
151                 /*
152                  * Need to make a copy and possibly remove radiotap header
153                  * and FCS from the original.
154                  */
155                 skb = skb_copy_expand(origskb, needed_headroom, 0, GFP_ATOMIC);
156
157                 origskb = remove_monitor_info(local, origskb, rtap_len);
158
159                 if (!skb)
160                         return origskb;
161         }
162
163         /* if necessary, prepend radiotap information */
164         if (!(status->flag & RX_FLAG_RADIOTAP)) {
165                 rtfixed = (void *) skb_push(skb, sizeof(*rtfixed));
166                 rtap_len = sizeof(*rthdr) + sizeof(*rtfixed);
167                 if (status->flag & RX_FLAG_TSFT) {
168                         rttsft = (void *) skb_push(skb, sizeof(*rttsft));
169                         rtap_len += 8;
170                 }
171                 rthdr = (void *) skb_push(skb, sizeof(*rthdr));
172                 memset(rthdr, 0, sizeof(*rthdr));
173                 memset(rtfixed, 0, sizeof(*rtfixed));
174                 rthdr->it_present =
175                         cpu_to_le32((1 << IEEE80211_RADIOTAP_FLAGS) |
176                                     (1 << IEEE80211_RADIOTAP_RATE) |
177                                     (1 << IEEE80211_RADIOTAP_CHANNEL) |
178                                     (1 << IEEE80211_RADIOTAP_DB_ANTSIGNAL) |
179                                     (1 << IEEE80211_RADIOTAP_RX_FLAGS));
180                 rtfixed->flags = 0;
181                 if (local->hw.flags & IEEE80211_HW_RX_INCLUDES_FCS)
182                         rtfixed->flags |= IEEE80211_RADIOTAP_F_FCS;
183
184                 if (rttsft) {
185                         *rttsft = cpu_to_le64(status->mactime);
186                         rthdr->it_present |=
187                                 cpu_to_le32(1 << IEEE80211_RADIOTAP_TSFT);
188                 }
189
190                 /* FIXME: when radiotap gets a 'bad PLCP' flag use it here */
191                 rtfixed->rx_flags = 0;
192                 if (status->flag &
193                     (RX_FLAG_FAILED_FCS_CRC | RX_FLAG_FAILED_PLCP_CRC))
194                         rtfixed->rx_flags |=
195                                 cpu_to_le16(IEEE80211_RADIOTAP_F_RX_BADFCS);
196
197                 rate = ieee80211_get_rate(local, status->phymode,
198                                           status->rate);
199                 if (rate)
200                         rtfixed->rate = rate->rate / 5;
201
202                 rtfixed->chan_freq = cpu_to_le16(status->freq);
203
204                 if (status->phymode == MODE_IEEE80211A)
205                         rtfixed->chan_flags =
206                                 cpu_to_le16(IEEE80211_CHAN_OFDM |
207                                             IEEE80211_CHAN_5GHZ);
208                 else
209                         rtfixed->chan_flags =
210                                 cpu_to_le16(IEEE80211_CHAN_DYN |
211                                             IEEE80211_CHAN_2GHZ);
212
213                 rtfixed->antsignal = status->ssi;
214                 rthdr->it_len = cpu_to_le16(rtap_len);
215         }
216
217         skb_reset_mac_header(skb);
218         skb->ip_summed = CHECKSUM_UNNECESSARY;
219         skb->pkt_type = PACKET_OTHERHOST;
220         skb->protocol = htons(ETH_P_802_2);
221
222         list_for_each_entry_rcu(sdata, &local->interfaces, list) {
223                 if (!netif_running(sdata->dev))
224                         continue;
225
226                 if (sdata->vif.type != IEEE80211_IF_TYPE_MNTR)
227                         continue;
228
229                 if (prev_dev) {
230                         skb2 = skb_clone(skb, GFP_ATOMIC);
231                         if (skb2) {
232                                 skb2->dev = prev_dev;
233                                 netif_rx(skb2);
234                         }
235                 }
236
237                 prev_dev = sdata->dev;
238                 sdata->dev->stats.rx_packets++;
239                 sdata->dev->stats.rx_bytes += skb->len;
240         }
241
242         if (prev_dev) {
243                 skb->dev = prev_dev;
244                 netif_rx(skb);
245         } else
246                 dev_kfree_skb(skb);
247
248         return origskb;
249 }
250
251
252 /* pre-rx handlers
253  *
254  * these don't have dev/sdata fields in the rx data
255  * The sta value should also not be used because it may
256  * be NULL even though a STA (in IBSS mode) will be added.
257  */
258
259 static ieee80211_txrx_result
260 ieee80211_rx_h_parse_qos(struct ieee80211_txrx_data *rx)
261 {
262         u8 *data = rx->skb->data;
263         int tid;
264
265         /* does the frame have a qos control field? */
266         if (WLAN_FC_IS_QOS_DATA(rx->fc)) {
267                 u8 *qc = data + ieee80211_get_hdrlen(rx->fc) - QOS_CONTROL_LEN;
268                 /* frame has qos control */
269                 tid = qc[0] & QOS_CONTROL_TID_MASK;
270                 if (qc[0] & IEEE80211_QOS_CONTROL_A_MSDU_PRESENT)
271                         rx->flags |= IEEE80211_TXRXD_RX_AMSDU;
272                 else
273                         rx->flags &= ~IEEE80211_TXRXD_RX_AMSDU;
274         } else {
275                 if (unlikely((rx->fc & IEEE80211_FCTL_FTYPE) == IEEE80211_FTYPE_MGMT)) {
276                         /* Separate TID for management frames */
277                         tid = NUM_RX_DATA_QUEUES - 1;
278                 } else {
279                         /* no qos control present */
280                         tid = 0; /* 802.1d - Best Effort */
281                 }
282         }
283
284         I802_DEBUG_INC(rx->local->wme_rx_queue[tid]);
285         /* only a debug counter, sta might not be assigned properly yet */
286         if (rx->sta)
287                 I802_DEBUG_INC(rx->sta->wme_rx_queue[tid]);
288
289         rx->u.rx.queue = tid;
290         /* Set skb->priority to 1d tag if highest order bit of TID is not set.
291          * For now, set skb->priority to 0 for other cases. */
292         rx->skb->priority = (tid > 7) ? 0 : tid;
293
294         return TXRX_CONTINUE;
295 }
296
297
298 static u32 ieee80211_rx_load_stats(struct ieee80211_local *local,
299                               struct sk_buff *skb,
300                               struct ieee80211_rx_status *status)
301 {
302         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
303         u32 load = 0, hdrtime;
304         struct ieee80211_rate *rate;
305         struct ieee80211_hw_mode *mode = local->hw.conf.mode;
306         int i;
307
308         /* Estimate total channel use caused by this frame */
309
310         if (unlikely(mode->num_rates < 0))
311                 return TXRX_CONTINUE;
312
313         rate = &mode->rates[0];
314         for (i = 0; i < mode->num_rates; i++) {
315                 if (mode->rates[i].val == status->rate) {
316                         rate = &mode->rates[i];
317                         break;
318                 }
319         }
320
321         /* 1 bit at 1 Mbit/s takes 1 usec; in channel_use values,
322          * 1 usec = 1/8 * (1080 / 10) = 13.5 */
323
324         if (mode->mode == MODE_IEEE80211A ||
325             (mode->mode == MODE_IEEE80211G &&
326              rate->flags & IEEE80211_RATE_ERP))
327                 hdrtime = CHAN_UTIL_HDR_SHORT;
328         else
329                 hdrtime = CHAN_UTIL_HDR_LONG;
330
331         load = hdrtime;
332         if (!is_multicast_ether_addr(hdr->addr1))
333                 load += hdrtime;
334
335         load += skb->len * rate->rate_inv;
336
337         /* Divide channel_use by 8 to avoid wrapping around the counter */
338         load >>= CHAN_UTIL_SHIFT;
339
340         return load;
341 }
342
343 ieee80211_rx_handler ieee80211_rx_pre_handlers[] =
344 {
345         ieee80211_rx_h_parse_qos,
346         NULL
347 };
348
349 /* rx handlers */
350
351 static ieee80211_txrx_result
352 ieee80211_rx_h_if_stats(struct ieee80211_txrx_data *rx)
353 {
354         if (rx->sta)
355                 rx->sta->channel_use_raw += rx->u.rx.load;
356         rx->sdata->channel_use_raw += rx->u.rx.load;
357         return TXRX_CONTINUE;
358 }
359
360 static ieee80211_txrx_result
361 ieee80211_rx_h_passive_scan(struct ieee80211_txrx_data *rx)
362 {
363         struct ieee80211_local *local = rx->local;
364         struct sk_buff *skb = rx->skb;
365
366         if (unlikely(local->sta_hw_scanning))
367                 return ieee80211_sta_rx_scan(rx->dev, skb, rx->u.rx.status);
368
369         if (unlikely(local->sta_sw_scanning)) {
370                 /* drop all the other packets during a software scan anyway */
371                 if (ieee80211_sta_rx_scan(rx->dev, skb, rx->u.rx.status)
372                     != TXRX_QUEUED)
373                         dev_kfree_skb(skb);
374                 return TXRX_QUEUED;
375         }
376
377         if (unlikely(rx->flags & IEEE80211_TXRXD_RXIN_SCAN)) {
378                 /* scanning finished during invoking of handlers */
379                 I802_DEBUG_INC(local->rx_handlers_drop_passive_scan);
380                 return TXRX_DROP;
381         }
382
383         return TXRX_CONTINUE;
384 }
385
386 static ieee80211_txrx_result
387 ieee80211_rx_h_check(struct ieee80211_txrx_data *rx)
388 {
389         struct ieee80211_hdr *hdr;
390         hdr = (struct ieee80211_hdr *) rx->skb->data;
391
392         /* Drop duplicate 802.11 retransmissions (IEEE 802.11 Chap. 9.2.9) */
393         if (rx->sta && !is_multicast_ether_addr(hdr->addr1)) {
394                 if (unlikely(rx->fc & IEEE80211_FCTL_RETRY &&
395                              rx->sta->last_seq_ctrl[rx->u.rx.queue] ==
396                              hdr->seq_ctrl)) {
397                         if (rx->flags & IEEE80211_TXRXD_RXRA_MATCH) {
398                                 rx->local->dot11FrameDuplicateCount++;
399                                 rx->sta->num_duplicates++;
400                         }
401                         return TXRX_DROP;
402                 } else
403                         rx->sta->last_seq_ctrl[rx->u.rx.queue] = hdr->seq_ctrl;
404         }
405
406         if (unlikely(rx->skb->len < 16)) {
407                 I802_DEBUG_INC(rx->local->rx_handlers_drop_short);
408                 return TXRX_DROP;
409         }
410
411         /* Drop disallowed frame classes based on STA auth/assoc state;
412          * IEEE 802.11, Chap 5.5.
413          *
414          * 80211.o does filtering only based on association state, i.e., it
415          * drops Class 3 frames from not associated stations. hostapd sends
416          * deauth/disassoc frames when needed. In addition, hostapd is
417          * responsible for filtering on both auth and assoc states.
418          */
419         if (unlikely(((rx->fc & IEEE80211_FCTL_FTYPE) == IEEE80211_FTYPE_DATA ||
420                       ((rx->fc & IEEE80211_FCTL_FTYPE) == IEEE80211_FTYPE_CTL &&
421                        (rx->fc & IEEE80211_FCTL_STYPE) == IEEE80211_STYPE_PSPOLL)) &&
422                      rx->sdata->vif.type != IEEE80211_IF_TYPE_IBSS &&
423                      (!rx->sta || !(rx->sta->flags & WLAN_STA_ASSOC)))) {
424                 if ((!(rx->fc & IEEE80211_FCTL_FROMDS) &&
425                      !(rx->fc & IEEE80211_FCTL_TODS) &&
426                      (rx->fc & IEEE80211_FCTL_FTYPE) == IEEE80211_FTYPE_DATA)
427                     || !(rx->flags & IEEE80211_TXRXD_RXRA_MATCH)) {
428                         /* Drop IBSS frames and frames for other hosts
429                          * silently. */
430                         return TXRX_DROP;
431                 }
432
433                 return TXRX_DROP;
434         }
435
436         return TXRX_CONTINUE;
437 }
438
439
440 static ieee80211_txrx_result
441 ieee80211_rx_h_decrypt(struct ieee80211_txrx_data *rx)
442 {
443         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) rx->skb->data;
444         int keyidx;
445         int hdrlen;
446         ieee80211_txrx_result result = TXRX_DROP;
447         struct ieee80211_key *stakey = NULL;
448
449         /*
450          * Key selection 101
451          *
452          * There are three types of keys:
453          *  - GTK (group keys)
454          *  - PTK (pairwise keys)
455          *  - STK (station-to-station pairwise keys)
456          *
457          * When selecting a key, we have to distinguish between multicast
458          * (including broadcast) and unicast frames, the latter can only
459          * use PTKs and STKs while the former always use GTKs. Unless, of
460          * course, actual WEP keys ("pre-RSNA") are used, then unicast
461          * frames can also use key indizes like GTKs. Hence, if we don't
462          * have a PTK/STK we check the key index for a WEP key.
463          *
464          * Note that in a regular BSS, multicast frames are sent by the
465          * AP only, associated stations unicast the frame to the AP first
466          * which then multicasts it on their behalf.
467          *
468          * There is also a slight problem in IBSS mode: GTKs are negotiated
469          * with each station, that is something we don't currently handle.
470          * The spec seems to expect that one negotiates the same key with
471          * every station but there's no such requirement; VLANs could be
472          * possible.
473          */
474
475         if (!(rx->fc & IEEE80211_FCTL_PROTECTED))
476                 return TXRX_CONTINUE;
477
478         /*
479          * No point in finding a key and decrypting if the frame is neither
480          * addressed to us nor a multicast frame.
481          */
482         if (!(rx->flags & IEEE80211_TXRXD_RXRA_MATCH))
483                 return TXRX_CONTINUE;
484
485         if (rx->sta)
486                 stakey = rcu_dereference(rx->sta->key);
487
488         if (!is_multicast_ether_addr(hdr->addr1) && stakey) {
489                 rx->key = stakey;
490         } else {
491                 /*
492                  * The device doesn't give us the IV so we won't be
493                  * able to look up the key. That's ok though, we
494                  * don't need to decrypt the frame, we just won't
495                  * be able to keep statistics accurate.
496                  * Except for key threshold notifications, should
497                  * we somehow allow the driver to tell us which key
498                  * the hardware used if this flag is set?
499                  */
500                 if ((rx->u.rx.status->flag & RX_FLAG_DECRYPTED) &&
501                     (rx->u.rx.status->flag & RX_FLAG_IV_STRIPPED))
502                         return TXRX_CONTINUE;
503
504                 hdrlen = ieee80211_get_hdrlen(rx->fc);
505
506                 if (rx->skb->len < 8 + hdrlen)
507                         return TXRX_DROP; /* TODO: count this? */
508
509                 /*
510                  * no need to call ieee80211_wep_get_keyidx,
511                  * it verifies a bunch of things we've done already
512                  */
513                 keyidx = rx->skb->data[hdrlen + 3] >> 6;
514
515                 rx->key = rcu_dereference(rx->sdata->keys[keyidx]);
516
517                 /*
518                  * RSNA-protected unicast frames should always be sent with
519                  * pairwise or station-to-station keys, but for WEP we allow
520                  * using a key index as well.
521                  */
522                 if (rx->key && rx->key->conf.alg != ALG_WEP &&
523                     !is_multicast_ether_addr(hdr->addr1))
524                         rx->key = NULL;
525         }
526
527         if (rx->key) {
528                 rx->key->tx_rx_count++;
529                 /* TODO: add threshold stuff again */
530         } else {
531 #ifdef CONFIG_MAC80211_DEBUG
532                 if (net_ratelimit())
533                         printk(KERN_DEBUG "%s: RX protected frame,"
534                                " but have no key\n", rx->dev->name);
535 #endif /* CONFIG_MAC80211_DEBUG */
536                 return TXRX_DROP;
537         }
538
539         /* Check for weak IVs if possible */
540         if (rx->sta && rx->key->conf.alg == ALG_WEP &&
541             ((rx->fc & IEEE80211_FCTL_FTYPE) == IEEE80211_FTYPE_DATA) &&
542             (!(rx->u.rx.status->flag & RX_FLAG_IV_STRIPPED) ||
543              !(rx->u.rx.status->flag & RX_FLAG_DECRYPTED)) &&
544             ieee80211_wep_is_weak_iv(rx->skb, rx->key))
545                 rx->sta->wep_weak_iv_count++;
546
547         switch (rx->key->conf.alg) {
548         case ALG_WEP:
549                 result = ieee80211_crypto_wep_decrypt(rx);
550                 break;
551         case ALG_TKIP:
552                 result = ieee80211_crypto_tkip_decrypt(rx);
553                 break;
554         case ALG_CCMP:
555                 result = ieee80211_crypto_ccmp_decrypt(rx);
556                 break;
557         }
558
559         /* either the frame has been decrypted or will be dropped */
560         rx->u.rx.status->flag |= RX_FLAG_DECRYPTED;
561
562         return result;
563 }
564
565 static void ap_sta_ps_start(struct net_device *dev, struct sta_info *sta)
566 {
567         struct ieee80211_sub_if_data *sdata;
568         DECLARE_MAC_BUF(mac);
569
570         sdata = IEEE80211_DEV_TO_SUB_IF(sta->dev);
571
572         if (sdata->bss)
573                 atomic_inc(&sdata->bss->num_sta_ps);
574         sta->flags |= WLAN_STA_PS;
575         sta->pspoll = 0;
576 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
577         printk(KERN_DEBUG "%s: STA %s aid %d enters power save mode\n",
578                dev->name, print_mac(mac, sta->addr), sta->aid);
579 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
580 }
581
582 static int ap_sta_ps_end(struct net_device *dev, struct sta_info *sta)
583 {
584         struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
585         struct sk_buff *skb;
586         int sent = 0;
587         struct ieee80211_sub_if_data *sdata;
588         struct ieee80211_tx_packet_data *pkt_data;
589         DECLARE_MAC_BUF(mac);
590
591         sdata = IEEE80211_DEV_TO_SUB_IF(sta->dev);
592         if (sdata->bss)
593                 atomic_dec(&sdata->bss->num_sta_ps);
594         sta->flags &= ~(WLAN_STA_PS | WLAN_STA_TIM);
595         sta->pspoll = 0;
596         if (!skb_queue_empty(&sta->ps_tx_buf)) {
597                 if (local->ops->set_tim)
598                         local->ops->set_tim(local_to_hw(local), sta->aid, 0);
599                 if (sdata->bss)
600                         bss_tim_clear(local, sdata->bss, sta->aid);
601         }
602 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
603         printk(KERN_DEBUG "%s: STA %s aid %d exits power save mode\n",
604                dev->name, print_mac(mac, sta->addr), sta->aid);
605 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
606         /* Send all buffered frames to the station */
607         while ((skb = skb_dequeue(&sta->tx_filtered)) != NULL) {
608                 pkt_data = (struct ieee80211_tx_packet_data *) skb->cb;
609                 sent++;
610                 pkt_data->flags |= IEEE80211_TXPD_REQUEUE;
611                 dev_queue_xmit(skb);
612         }
613         while ((skb = skb_dequeue(&sta->ps_tx_buf)) != NULL) {
614                 pkt_data = (struct ieee80211_tx_packet_data *) skb->cb;
615                 local->total_ps_buffered--;
616                 sent++;
617 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
618                 printk(KERN_DEBUG "%s: STA %s aid %d send PS frame "
619                        "since STA not sleeping anymore\n", dev->name,
620                        print_mac(mac, sta->addr), sta->aid);
621 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
622                 pkt_data->flags |= IEEE80211_TXPD_REQUEUE;
623                 dev_queue_xmit(skb);
624         }
625
626         return sent;
627 }
628
629 static ieee80211_txrx_result
630 ieee80211_rx_h_sta_process(struct ieee80211_txrx_data *rx)
631 {
632         struct sta_info *sta = rx->sta;
633         struct net_device *dev = rx->dev;
634         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) rx->skb->data;
635
636         if (!sta)
637                 return TXRX_CONTINUE;
638
639         /* Update last_rx only for IBSS packets which are for the current
640          * BSSID to avoid keeping the current IBSS network alive in cases where
641          * other STAs are using different BSSID. */
642         if (rx->sdata->vif.type == IEEE80211_IF_TYPE_IBSS) {
643                 u8 *bssid = ieee80211_get_bssid(hdr, rx->skb->len,
644                                                 IEEE80211_IF_TYPE_IBSS);
645                 if (compare_ether_addr(bssid, rx->sdata->u.sta.bssid) == 0)
646                         sta->last_rx = jiffies;
647         } else
648         if (!is_multicast_ether_addr(hdr->addr1) ||
649             rx->sdata->vif.type == IEEE80211_IF_TYPE_STA) {
650                 /* Update last_rx only for unicast frames in order to prevent
651                  * the Probe Request frames (the only broadcast frames from a
652                  * STA in infrastructure mode) from keeping a connection alive.
653                  */
654                 sta->last_rx = jiffies;
655         }
656
657         if (!(rx->flags & IEEE80211_TXRXD_RXRA_MATCH))
658                 return TXRX_CONTINUE;
659
660         sta->rx_fragments++;
661         sta->rx_bytes += rx->skb->len;
662         sta->last_rssi = rx->u.rx.status->ssi;
663         sta->last_signal = rx->u.rx.status->signal;
664         sta->last_noise = rx->u.rx.status->noise;
665
666         if (!(rx->fc & IEEE80211_FCTL_MOREFRAGS)) {
667                 /* Change STA power saving mode only in the end of a frame
668                  * exchange sequence */
669                 if ((sta->flags & WLAN_STA_PS) && !(rx->fc & IEEE80211_FCTL_PM))
670                         rx->u.rx.sent_ps_buffered += ap_sta_ps_end(dev, sta);
671                 else if (!(sta->flags & WLAN_STA_PS) &&
672                          (rx->fc & IEEE80211_FCTL_PM))
673                         ap_sta_ps_start(dev, sta);
674         }
675
676         /* Drop data::nullfunc frames silently, since they are used only to
677          * control station power saving mode. */
678         if ((rx->fc & IEEE80211_FCTL_FTYPE) == IEEE80211_FTYPE_DATA &&
679             (rx->fc & IEEE80211_FCTL_STYPE) == IEEE80211_STYPE_NULLFUNC) {
680                 I802_DEBUG_INC(rx->local->rx_handlers_drop_nullfunc);
681                 /* Update counter and free packet here to avoid counting this
682                  * as a dropped packed. */
683                 sta->rx_packets++;
684                 dev_kfree_skb(rx->skb);
685                 return TXRX_QUEUED;
686         }
687
688         return TXRX_CONTINUE;
689 } /* ieee80211_rx_h_sta_process */
690
691 static inline struct ieee80211_fragment_entry *
692 ieee80211_reassemble_add(struct ieee80211_sub_if_data *sdata,
693                          unsigned int frag, unsigned int seq, int rx_queue,
694                          struct sk_buff **skb)
695 {
696         struct ieee80211_fragment_entry *entry;
697         int idx;
698
699         idx = sdata->fragment_next;
700         entry = &sdata->fragments[sdata->fragment_next++];
701         if (sdata->fragment_next >= IEEE80211_FRAGMENT_MAX)
702                 sdata->fragment_next = 0;
703
704         if (!skb_queue_empty(&entry->skb_list)) {
705 #ifdef CONFIG_MAC80211_DEBUG
706                 struct ieee80211_hdr *hdr =
707                         (struct ieee80211_hdr *) entry->skb_list.next->data;
708                 DECLARE_MAC_BUF(mac);
709                 DECLARE_MAC_BUF(mac2);
710                 printk(KERN_DEBUG "%s: RX reassembly removed oldest "
711                        "fragment entry (idx=%d age=%lu seq=%d last_frag=%d "
712                        "addr1=%s addr2=%s\n",
713                        sdata->dev->name, idx,
714                        jiffies - entry->first_frag_time, entry->seq,
715                        entry->last_frag, print_mac(mac, hdr->addr1),
716                        print_mac(mac2, hdr->addr2));
717 #endif /* CONFIG_MAC80211_DEBUG */
718                 __skb_queue_purge(&entry->skb_list);
719         }
720
721         __skb_queue_tail(&entry->skb_list, *skb); /* no need for locking */
722         *skb = NULL;
723         entry->first_frag_time = jiffies;
724         entry->seq = seq;
725         entry->rx_queue = rx_queue;
726         entry->last_frag = frag;
727         entry->ccmp = 0;
728         entry->extra_len = 0;
729
730         return entry;
731 }
732
733 static inline struct ieee80211_fragment_entry *
734 ieee80211_reassemble_find(struct ieee80211_sub_if_data *sdata,
735                           u16 fc, unsigned int frag, unsigned int seq,
736                           int rx_queue, struct ieee80211_hdr *hdr)
737 {
738         struct ieee80211_fragment_entry *entry;
739         int i, idx;
740
741         idx = sdata->fragment_next;
742         for (i = 0; i < IEEE80211_FRAGMENT_MAX; i++) {
743                 struct ieee80211_hdr *f_hdr;
744                 u16 f_fc;
745
746                 idx--;
747                 if (idx < 0)
748                         idx = IEEE80211_FRAGMENT_MAX - 1;
749
750                 entry = &sdata->fragments[idx];
751                 if (skb_queue_empty(&entry->skb_list) || entry->seq != seq ||
752                     entry->rx_queue != rx_queue ||
753                     entry->last_frag + 1 != frag)
754                         continue;
755
756                 f_hdr = (struct ieee80211_hdr *) entry->skb_list.next->data;
757                 f_fc = le16_to_cpu(f_hdr->frame_control);
758
759                 if ((fc & IEEE80211_FCTL_FTYPE) != (f_fc & IEEE80211_FCTL_FTYPE) ||
760                     compare_ether_addr(hdr->addr1, f_hdr->addr1) != 0 ||
761                     compare_ether_addr(hdr->addr2, f_hdr->addr2) != 0)
762                         continue;
763
764                 if (entry->first_frag_time + 2 * HZ < jiffies) {
765                         __skb_queue_purge(&entry->skb_list);
766                         continue;
767                 }
768                 return entry;
769         }
770
771         return NULL;
772 }
773
774 static ieee80211_txrx_result
775 ieee80211_rx_h_defragment(struct ieee80211_txrx_data *rx)
776 {
777         struct ieee80211_hdr *hdr;
778         u16 sc;
779         unsigned int frag, seq;
780         struct ieee80211_fragment_entry *entry;
781         struct sk_buff *skb;
782         DECLARE_MAC_BUF(mac);
783
784         hdr = (struct ieee80211_hdr *) rx->skb->data;
785         sc = le16_to_cpu(hdr->seq_ctrl);
786         frag = sc & IEEE80211_SCTL_FRAG;
787
788         if (likely((!(rx->fc & IEEE80211_FCTL_MOREFRAGS) && frag == 0) ||
789                    (rx->skb)->len < 24 ||
790                    is_multicast_ether_addr(hdr->addr1))) {
791                 /* not fragmented */
792                 goto out;
793         }
794         I802_DEBUG_INC(rx->local->rx_handlers_fragments);
795
796         seq = (sc & IEEE80211_SCTL_SEQ) >> 4;
797
798         if (frag == 0) {
799                 /* This is the first fragment of a new frame. */
800                 entry = ieee80211_reassemble_add(rx->sdata, frag, seq,
801                                                  rx->u.rx.queue, &(rx->skb));
802                 if (rx->key && rx->key->conf.alg == ALG_CCMP &&
803                     (rx->fc & IEEE80211_FCTL_PROTECTED)) {
804                         /* Store CCMP PN so that we can verify that the next
805                          * fragment has a sequential PN value. */
806                         entry->ccmp = 1;
807                         memcpy(entry->last_pn,
808                                rx->key->u.ccmp.rx_pn[rx->u.rx.queue],
809                                CCMP_PN_LEN);
810                 }
811                 return TXRX_QUEUED;
812         }
813
814         /* This is a fragment for a frame that should already be pending in
815          * fragment cache. Add this fragment to the end of the pending entry.
816          */
817         entry = ieee80211_reassemble_find(rx->sdata, rx->fc, frag, seq,
818                                           rx->u.rx.queue, hdr);
819         if (!entry) {
820                 I802_DEBUG_INC(rx->local->rx_handlers_drop_defrag);
821                 return TXRX_DROP;
822         }
823
824         /* Verify that MPDUs within one MSDU have sequential PN values.
825          * (IEEE 802.11i, 8.3.3.4.5) */
826         if (entry->ccmp) {
827                 int i;
828                 u8 pn[CCMP_PN_LEN], *rpn;
829                 if (!rx->key || rx->key->conf.alg != ALG_CCMP)
830                         return TXRX_DROP;
831                 memcpy(pn, entry->last_pn, CCMP_PN_LEN);
832                 for (i = CCMP_PN_LEN - 1; i >= 0; i--) {
833                         pn[i]++;
834                         if (pn[i])
835                                 break;
836                 }
837                 rpn = rx->key->u.ccmp.rx_pn[rx->u.rx.queue];
838                 if (memcmp(pn, rpn, CCMP_PN_LEN) != 0) {
839                         if (net_ratelimit())
840                                 printk(KERN_DEBUG "%s: defrag: CCMP PN not "
841                                        "sequential A2=%s"
842                                        " PN=%02x%02x%02x%02x%02x%02x "
843                                        "(expected %02x%02x%02x%02x%02x%02x)\n",
844                                        rx->dev->name, print_mac(mac, hdr->addr2),
845                                        rpn[0], rpn[1], rpn[2], rpn[3], rpn[4],
846                                        rpn[5], pn[0], pn[1], pn[2], pn[3],
847                                        pn[4], pn[5]);
848                         return TXRX_DROP;
849                 }
850                 memcpy(entry->last_pn, pn, CCMP_PN_LEN);
851         }
852
853         skb_pull(rx->skb, ieee80211_get_hdrlen(rx->fc));
854         __skb_queue_tail(&entry->skb_list, rx->skb);
855         entry->last_frag = frag;
856         entry->extra_len += rx->skb->len;
857         if (rx->fc & IEEE80211_FCTL_MOREFRAGS) {
858                 rx->skb = NULL;
859                 return TXRX_QUEUED;
860         }
861
862         rx->skb = __skb_dequeue(&entry->skb_list);
863         if (skb_tailroom(rx->skb) < entry->extra_len) {
864                 I802_DEBUG_INC(rx->local->rx_expand_skb_head2);
865                 if (unlikely(pskb_expand_head(rx->skb, 0, entry->extra_len,
866                                               GFP_ATOMIC))) {
867                         I802_DEBUG_INC(rx->local->rx_handlers_drop_defrag);
868                         __skb_queue_purge(&entry->skb_list);
869                         return TXRX_DROP;
870                 }
871         }
872         while ((skb = __skb_dequeue(&entry->skb_list))) {
873                 memcpy(skb_put(rx->skb, skb->len), skb->data, skb->len);
874                 dev_kfree_skb(skb);
875         }
876
877         /* Complete frame has been reassembled - process it now */
878         rx->flags |= IEEE80211_TXRXD_FRAGMENTED;
879
880  out:
881         if (rx->sta)
882                 rx->sta->rx_packets++;
883         if (is_multicast_ether_addr(hdr->addr1))
884                 rx->local->dot11MulticastReceivedFrameCount++;
885         else
886                 ieee80211_led_rx(rx->local);
887         return TXRX_CONTINUE;
888 }
889
890 static ieee80211_txrx_result
891 ieee80211_rx_h_ps_poll(struct ieee80211_txrx_data *rx)
892 {
893         struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(rx->dev);
894         struct sk_buff *skb;
895         int no_pending_pkts;
896         DECLARE_MAC_BUF(mac);
897
898         if (likely(!rx->sta ||
899                    (rx->fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_CTL ||
900                    (rx->fc & IEEE80211_FCTL_STYPE) != IEEE80211_STYPE_PSPOLL ||
901                    !(rx->flags & IEEE80211_TXRXD_RXRA_MATCH)))
902                 return TXRX_CONTINUE;
903
904         if ((sdata->vif.type != IEEE80211_IF_TYPE_AP) &&
905             (sdata->vif.type != IEEE80211_IF_TYPE_VLAN))
906                 return TXRX_DROP;
907
908         skb = skb_dequeue(&rx->sta->tx_filtered);
909         if (!skb) {
910                 skb = skb_dequeue(&rx->sta->ps_tx_buf);
911                 if (skb)
912                         rx->local->total_ps_buffered--;
913         }
914         no_pending_pkts = skb_queue_empty(&rx->sta->tx_filtered) &&
915                 skb_queue_empty(&rx->sta->ps_tx_buf);
916
917         if (skb) {
918                 struct ieee80211_hdr *hdr =
919                         (struct ieee80211_hdr *) skb->data;
920
921                 /* tell TX path to send one frame even though the STA may
922                  * still remain is PS mode after this frame exchange */
923                 rx->sta->pspoll = 1;
924
925 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
926                 printk(KERN_DEBUG "STA %s aid %d: PS Poll (entries after %d)\n",
927                        print_mac(mac, rx->sta->addr), rx->sta->aid,
928                        skb_queue_len(&rx->sta->ps_tx_buf));
929 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
930
931                 /* Use MoreData flag to indicate whether there are more
932                  * buffered frames for this STA */
933                 if (no_pending_pkts) {
934                         hdr->frame_control &= cpu_to_le16(~IEEE80211_FCTL_MOREDATA);
935                         rx->sta->flags &= ~WLAN_STA_TIM;
936                 } else
937                         hdr->frame_control |= cpu_to_le16(IEEE80211_FCTL_MOREDATA);
938
939                 dev_queue_xmit(skb);
940
941                 if (no_pending_pkts) {
942                         if (rx->local->ops->set_tim)
943                                 rx->local->ops->set_tim(local_to_hw(rx->local),
944                                                        rx->sta->aid, 0);
945                         if (rx->sdata->bss)
946                                 bss_tim_clear(rx->local, rx->sdata->bss, rx->sta->aid);
947                 }
948 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
949         } else if (!rx->u.rx.sent_ps_buffered) {
950                 printk(KERN_DEBUG "%s: STA %s sent PS Poll even "
951                        "though there is no buffered frames for it\n",
952                        rx->dev->name, print_mac(mac, rx->sta->addr));
953 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
954
955         }
956
957         /* Free PS Poll skb here instead of returning TXRX_DROP that would
958          * count as an dropped frame. */
959         dev_kfree_skb(rx->skb);
960
961         return TXRX_QUEUED;
962 }
963
964 static ieee80211_txrx_result
965 ieee80211_rx_h_remove_qos_control(struct ieee80211_txrx_data *rx)
966 {
967         u16 fc = rx->fc;
968         u8 *data = rx->skb->data;
969         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) data;
970
971         if (!WLAN_FC_IS_QOS_DATA(fc))
972                 return TXRX_CONTINUE;
973
974         /* remove the qos control field, update frame type and meta-data */
975         memmove(data + 2, data, ieee80211_get_hdrlen(fc) - 2);
976         hdr = (struct ieee80211_hdr *) skb_pull(rx->skb, 2);
977         /* change frame type to non QOS */
978         rx->fc = fc &= ~IEEE80211_STYPE_QOS_DATA;
979         hdr->frame_control = cpu_to_le16(fc);
980
981         return TXRX_CONTINUE;
982 }
983
984 static int
985 ieee80211_802_1x_port_control(struct ieee80211_txrx_data *rx)
986 {
987         if (unlikely(rx->sdata->ieee802_1x_pac &&
988                      (!rx->sta || !(rx->sta->flags & WLAN_STA_AUTHORIZED)))) {
989 #ifdef CONFIG_MAC80211_DEBUG
990                 printk(KERN_DEBUG "%s: dropped frame "
991                        "(unauthorized port)\n", rx->dev->name);
992 #endif /* CONFIG_MAC80211_DEBUG */
993                 return -EACCES;
994         }
995
996         return 0;
997 }
998
999 static int
1000 ieee80211_drop_unencrypted(struct ieee80211_txrx_data *rx)
1001 {
1002         /*
1003          * Pass through unencrypted frames if the hardware has
1004          * decrypted them already.
1005          */
1006         if (rx->u.rx.status->flag & RX_FLAG_DECRYPTED)
1007                 return 0;
1008
1009         /* Drop unencrypted frames if key is set. */
1010         if (unlikely(!(rx->fc & IEEE80211_FCTL_PROTECTED) &&
1011                      (rx->fc & IEEE80211_FCTL_FTYPE) == IEEE80211_FTYPE_DATA &&
1012                      (rx->fc & IEEE80211_FCTL_STYPE) != IEEE80211_STYPE_NULLFUNC &&
1013                      (rx->key || rx->sdata->drop_unencrypted))) {
1014                 if (net_ratelimit())
1015                         printk(KERN_DEBUG "%s: RX non-WEP frame, but expected "
1016                                "encryption\n", rx->dev->name);
1017                 return -EACCES;
1018         }
1019         return 0;
1020 }
1021
1022 static int
1023 ieee80211_data_to_8023(struct ieee80211_txrx_data *rx)
1024 {
1025         struct net_device *dev = rx->dev;
1026         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) rx->skb->data;
1027         u16 fc, hdrlen, ethertype;
1028         u8 *payload;
1029         u8 dst[ETH_ALEN];
1030         u8 src[ETH_ALEN];
1031         struct sk_buff *skb = rx->skb;
1032         struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
1033         DECLARE_MAC_BUF(mac);
1034         DECLARE_MAC_BUF(mac2);
1035         DECLARE_MAC_BUF(mac3);
1036         DECLARE_MAC_BUF(mac4);
1037
1038         fc = rx->fc;
1039
1040         if (unlikely(!WLAN_FC_DATA_PRESENT(fc)))
1041                 return -1;
1042
1043         hdrlen = ieee80211_get_hdrlen(fc);
1044
1045         /* convert IEEE 802.11 header + possible LLC headers into Ethernet
1046          * header
1047          * IEEE 802.11 address fields:
1048          * ToDS FromDS Addr1 Addr2 Addr3 Addr4
1049          *   0     0   DA    SA    BSSID n/a
1050          *   0     1   DA    BSSID SA    n/a
1051          *   1     0   BSSID SA    DA    n/a
1052          *   1     1   RA    TA    DA    SA
1053          */
1054
1055         switch (fc & (IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS)) {
1056         case IEEE80211_FCTL_TODS:
1057                 /* BSSID SA DA */
1058                 memcpy(dst, hdr->addr3, ETH_ALEN);
1059                 memcpy(src, hdr->addr2, ETH_ALEN);
1060
1061                 if (unlikely(sdata->vif.type != IEEE80211_IF_TYPE_AP &&
1062                              sdata->vif.type != IEEE80211_IF_TYPE_VLAN)) {
1063                         if (net_ratelimit())
1064                                 printk(KERN_DEBUG "%s: dropped ToDS frame "
1065                                        "(BSSID=%s SA=%s DA=%s)\n",
1066                                        dev->name,
1067                                        print_mac(mac, hdr->addr1),
1068                                        print_mac(mac2, hdr->addr2),
1069                                        print_mac(mac3, hdr->addr3));
1070                         return -1;
1071                 }
1072                 break;
1073         case (IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS):
1074                 /* RA TA DA SA */
1075                 memcpy(dst, hdr->addr3, ETH_ALEN);
1076                 memcpy(src, hdr->addr4, ETH_ALEN);
1077
1078                 if (unlikely(sdata->vif.type != IEEE80211_IF_TYPE_WDS)) {
1079                         if (net_ratelimit())
1080                                 printk(KERN_DEBUG "%s: dropped FromDS&ToDS "
1081                                        "frame (RA=%s TA=%s DA=%s SA=%s)\n",
1082                                        rx->dev->name,
1083                                        print_mac(mac, hdr->addr1),
1084                                        print_mac(mac2, hdr->addr2),
1085                                        print_mac(mac3, hdr->addr3),
1086                                        print_mac(mac4, hdr->addr4));
1087                         return -1;
1088                 }
1089                 break;
1090         case IEEE80211_FCTL_FROMDS:
1091                 /* DA BSSID SA */
1092                 memcpy(dst, hdr->addr1, ETH_ALEN);
1093                 memcpy(src, hdr->addr3, ETH_ALEN);
1094
1095                 if (sdata->vif.type != IEEE80211_IF_TYPE_STA ||
1096                     (is_multicast_ether_addr(dst) &&
1097                      !compare_ether_addr(src, dev->dev_addr)))
1098                         return -1;
1099                 break;
1100         case 0:
1101                 /* DA SA BSSID */
1102                 memcpy(dst, hdr->addr1, ETH_ALEN);
1103                 memcpy(src, hdr->addr2, ETH_ALEN);
1104
1105                 if (sdata->vif.type != IEEE80211_IF_TYPE_IBSS) {
1106                         if (net_ratelimit()) {
1107                                 printk(KERN_DEBUG "%s: dropped IBSS frame "
1108                                        "(DA=%s SA=%s BSSID=%s)\n",
1109                                        dev->name,
1110                                        print_mac(mac, hdr->addr1),
1111                                        print_mac(mac2, hdr->addr2),
1112                                        print_mac(mac3, hdr->addr3));
1113                         }
1114                         return -1;
1115                 }
1116                 break;
1117         }
1118
1119         if (unlikely(skb->len - hdrlen < 8)) {
1120                 if (net_ratelimit()) {
1121                         printk(KERN_DEBUG "%s: RX too short data frame "
1122                                "payload\n", dev->name);
1123                 }
1124                 return -1;
1125         }
1126
1127         payload = skb->data + hdrlen;
1128         ethertype = (payload[6] << 8) | payload[7];
1129
1130         if (likely((compare_ether_addr(payload, rfc1042_header) == 0 &&
1131                     ethertype != ETH_P_AARP && ethertype != ETH_P_IPX) ||
1132                    compare_ether_addr(payload, bridge_tunnel_header) == 0)) {
1133                 /* remove RFC1042 or Bridge-Tunnel encapsulation and
1134                  * replace EtherType */
1135                 skb_pull(skb, hdrlen + 6);
1136                 memcpy(skb_push(skb, ETH_ALEN), src, ETH_ALEN);
1137                 memcpy(skb_push(skb, ETH_ALEN), dst, ETH_ALEN);
1138         } else {
1139                 struct ethhdr *ehdr;
1140                 __be16 len;
1141
1142                 skb_pull(skb, hdrlen);
1143                 len = htons(skb->len);
1144                 ehdr = (struct ethhdr *) skb_push(skb, sizeof(struct ethhdr));
1145                 memcpy(ehdr->h_dest, dst, ETH_ALEN);
1146                 memcpy(ehdr->h_source, src, ETH_ALEN);
1147                 ehdr->h_proto = len;
1148         }
1149         return 0;
1150 }
1151
1152 /*
1153  * requires that rx->skb is a frame with ethernet header
1154  */
1155 static bool ieee80211_frame_allowed(struct ieee80211_txrx_data *rx)
1156 {
1157         static const u8 pae_group_addr[ETH_ALEN]
1158                 = { 0x01, 0x80, 0xC2, 0x00, 0x00, 0x03 };
1159         struct ethhdr *ehdr = (struct ethhdr *) rx->skb->data;
1160
1161         /*
1162          * Allow EAPOL frames to us/the PAE group address regardless
1163          * of whether the frame was encrypted or not.
1164          */
1165         if (ehdr->h_proto == htons(ETH_P_PAE) &&
1166             (compare_ether_addr(ehdr->h_dest, rx->dev->dev_addr) == 0 ||
1167              compare_ether_addr(ehdr->h_dest, pae_group_addr) == 0))
1168                 return true;
1169
1170         if (ieee80211_802_1x_port_control(rx) ||
1171             ieee80211_drop_unencrypted(rx))
1172                 return false;
1173
1174         return true;
1175 }
1176
1177 /*
1178  * requires that rx->skb is a frame with ethernet header
1179  */
1180 static void
1181 ieee80211_deliver_skb(struct ieee80211_txrx_data *rx)
1182 {
1183         struct net_device *dev = rx->dev;
1184         struct ieee80211_local *local = rx->local;
1185         struct sk_buff *skb, *xmit_skb;
1186         struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
1187         struct ethhdr *ehdr = (struct ethhdr *) rx->skb->data;
1188         struct sta_info *dsta;
1189
1190         skb = rx->skb;
1191         xmit_skb = NULL;
1192
1193         if (local->bridge_packets && (sdata->vif.type == IEEE80211_IF_TYPE_AP ||
1194                                       sdata->vif.type == IEEE80211_IF_TYPE_VLAN) &&
1195             (rx->flags & IEEE80211_TXRXD_RXRA_MATCH)) {
1196                 if (is_multicast_ether_addr(ehdr->h_dest)) {
1197                         /*
1198                          * send multicast frames both to higher layers in
1199                          * local net stack and back to the wireless medium
1200                          */
1201                         xmit_skb = skb_copy(skb, GFP_ATOMIC);
1202                         if (!xmit_skb && net_ratelimit())
1203                                 printk(KERN_DEBUG "%s: failed to clone "
1204                                        "multicast frame\n", dev->name);
1205                 } else {
1206                         dsta = sta_info_get(local, skb->data);
1207                         if (dsta && dsta->dev == dev) {
1208                                 /*
1209                                  * The destination station is associated to
1210                                  * this AP (in this VLAN), so send the frame
1211                                  * directly to it and do not pass it to local
1212                                  * net stack.
1213                                  */
1214                                 xmit_skb = skb;
1215                                 skb = NULL;
1216                         }
1217                         if (dsta)
1218                                 sta_info_put(dsta);
1219                 }
1220         }
1221
1222         if (skb) {
1223                 /* deliver to local stack */
1224                 skb->protocol = eth_type_trans(skb, dev);
1225                 memset(skb->cb, 0, sizeof(skb->cb));
1226                 netif_rx(skb);
1227         }
1228
1229         if (xmit_skb) {
1230                 /* send to wireless media */
1231                 xmit_skb->protocol = htons(ETH_P_802_3);
1232                 skb_reset_network_header(xmit_skb);
1233                 skb_reset_mac_header(xmit_skb);
1234                 dev_queue_xmit(xmit_skb);
1235         }
1236 }
1237
1238 static ieee80211_txrx_result
1239 ieee80211_rx_h_amsdu(struct ieee80211_txrx_data *rx)
1240 {
1241         struct net_device *dev = rx->dev;
1242         struct ieee80211_local *local = rx->local;
1243         u16 fc, ethertype;
1244         u8 *payload;
1245         struct sk_buff *skb = rx->skb, *frame = NULL;
1246         const struct ethhdr *eth;
1247         int remaining, err;
1248         u8 dst[ETH_ALEN];
1249         u8 src[ETH_ALEN];
1250         DECLARE_MAC_BUF(mac);
1251
1252         fc = rx->fc;
1253         if (unlikely((fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_DATA))
1254                 return TXRX_CONTINUE;
1255
1256         if (unlikely(!WLAN_FC_DATA_PRESENT(fc)))
1257                 return TXRX_DROP;
1258
1259         if (!(rx->flags & IEEE80211_TXRXD_RX_AMSDU))
1260                 return TXRX_CONTINUE;
1261
1262         err = ieee80211_data_to_8023(rx);
1263         if (unlikely(err))
1264                 return TXRX_DROP;
1265
1266         skb->dev = dev;
1267
1268         dev->stats.rx_packets++;
1269         dev->stats.rx_bytes += skb->len;
1270
1271         /* skip the wrapping header */
1272         eth = (struct ethhdr *) skb_pull(skb, sizeof(struct ethhdr));
1273         if (!eth)
1274                 return TXRX_DROP;
1275
1276         while (skb != frame) {
1277                 u8 padding;
1278                 __be16 len = eth->h_proto;
1279                 unsigned int subframe_len = sizeof(struct ethhdr) + ntohs(len);
1280
1281                 remaining = skb->len;
1282                 memcpy(dst, eth->h_dest, ETH_ALEN);
1283                 memcpy(src, eth->h_source, ETH_ALEN);
1284
1285                 padding = ((4 - subframe_len) & 0x3);
1286                 /* the last MSDU has no padding */
1287                 if (subframe_len > remaining) {
1288                         printk(KERN_DEBUG "%s: wrong buffer size", dev->name);
1289                         return TXRX_DROP;
1290                 }
1291
1292                 skb_pull(skb, sizeof(struct ethhdr));
1293                 /* if last subframe reuse skb */
1294                 if (remaining <= subframe_len + padding)
1295                         frame = skb;
1296                 else {
1297                         frame = dev_alloc_skb(local->hw.extra_tx_headroom +
1298                                               subframe_len);
1299
1300                         if (frame == NULL)
1301                                 return TXRX_DROP;
1302
1303                         skb_reserve(frame, local->hw.extra_tx_headroom +
1304                                     sizeof(struct ethhdr));
1305                         memcpy(skb_put(frame, ntohs(len)), skb->data,
1306                                 ntohs(len));
1307
1308                         eth = (struct ethhdr *) skb_pull(skb, ntohs(len) +
1309                                                         padding);
1310                         if (!eth) {
1311                                 printk(KERN_DEBUG "%s: wrong buffer size ",
1312                                        dev->name);
1313                                 dev_kfree_skb(frame);
1314                                 return TXRX_DROP;
1315                         }
1316                 }
1317
1318                 skb_reset_network_header(frame);
1319                 frame->dev = dev;
1320                 frame->priority = skb->priority;
1321                 rx->skb = frame;
1322
1323                 payload = frame->data;
1324                 ethertype = (payload[6] << 8) | payload[7];
1325
1326                 if (likely((compare_ether_addr(payload, rfc1042_header) == 0 &&
1327                             ethertype != ETH_P_AARP && ethertype != ETH_P_IPX) ||
1328                            compare_ether_addr(payload,
1329                                               bridge_tunnel_header) == 0)) {
1330                         /* remove RFC1042 or Bridge-Tunnel
1331                          * encapsulation and replace EtherType */
1332                         skb_pull(frame, 6);
1333                         memcpy(skb_push(frame, ETH_ALEN), src, ETH_ALEN);
1334                         memcpy(skb_push(frame, ETH_ALEN), dst, ETH_ALEN);
1335                 } else {
1336                         memcpy(skb_push(frame, sizeof(__be16)),
1337                                &len, sizeof(__be16));
1338                         memcpy(skb_push(frame, ETH_ALEN), src, ETH_ALEN);
1339                         memcpy(skb_push(frame, ETH_ALEN), dst, ETH_ALEN);
1340                 }
1341
1342                 if (!ieee80211_frame_allowed(rx)) {
1343                         if (skb == frame) /* last frame */
1344                                 return TXRX_DROP;
1345                         dev_kfree_skb(frame);
1346                         continue;
1347                 }
1348
1349                 ieee80211_deliver_skb(rx);
1350         }
1351
1352         return TXRX_QUEUED;
1353 }
1354
1355 static ieee80211_txrx_result
1356 ieee80211_rx_h_data(struct ieee80211_txrx_data *rx)
1357 {
1358         struct net_device *dev = rx->dev;
1359         u16 fc;
1360         int err;
1361
1362         fc = rx->fc;
1363         if (unlikely((fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_DATA))
1364                 return TXRX_CONTINUE;
1365
1366         if (unlikely(!WLAN_FC_DATA_PRESENT(fc)))
1367                 return TXRX_DROP;
1368
1369         err = ieee80211_data_to_8023(rx);
1370         if (unlikely(err))
1371                 return TXRX_DROP;
1372
1373         if (!ieee80211_frame_allowed(rx))
1374                 return TXRX_DROP;
1375
1376         rx->skb->dev = dev;
1377
1378         dev->stats.rx_packets++;
1379         dev->stats.rx_bytes += rx->skb->len;
1380
1381         ieee80211_deliver_skb(rx);
1382
1383         return TXRX_QUEUED;
1384 }
1385
1386 static ieee80211_txrx_result
1387 ieee80211_rx_h_ctrl(struct ieee80211_txrx_data *rx)
1388 {
1389         struct ieee80211_local *local = rx->local;
1390         struct ieee80211_hw *hw = &local->hw;
1391         struct sk_buff *skb = rx->skb;
1392         struct ieee80211_bar *bar = (struct ieee80211_bar *) skb->data;
1393         struct tid_ampdu_rx *tid_agg_rx;
1394         u16 start_seq_num;
1395         u16 tid;
1396
1397         if (likely((rx->fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_CTL))
1398                 return TXRX_CONTINUE;
1399
1400         if ((rx->fc & IEEE80211_FCTL_STYPE) == IEEE80211_STYPE_BACK_REQ) {
1401                 if (!rx->sta)
1402                         return TXRX_CONTINUE;
1403                 tid = le16_to_cpu(bar->control) >> 12;
1404                 tid_agg_rx = &(rx->sta->ampdu_mlme.tid_rx[tid]);
1405                 if (tid_agg_rx->state != HT_AGG_STATE_OPERATIONAL)
1406                         return TXRX_CONTINUE;
1407
1408                 start_seq_num = le16_to_cpu(bar->start_seq_num) >> 4;
1409
1410                 /* reset session timer */
1411                 if (tid_agg_rx->timeout) {
1412                         unsigned long expires =
1413                                 jiffies + (tid_agg_rx->timeout / 1000) * HZ;
1414                         mod_timer(&tid_agg_rx->session_timer, expires);
1415                 }
1416
1417                 /* manage reordering buffer according to requested */
1418                 /* sequence number */
1419                 rcu_read_lock();
1420                 ieee80211_sta_manage_reorder_buf(hw, tid_agg_rx, NULL,
1421                                                  start_seq_num, 1);
1422                 rcu_read_unlock();
1423                 return TXRX_DROP;
1424         }
1425
1426         return TXRX_CONTINUE;
1427 }
1428
1429 static ieee80211_txrx_result
1430 ieee80211_rx_h_mgmt(struct ieee80211_txrx_data *rx)
1431 {
1432         struct ieee80211_sub_if_data *sdata;
1433
1434         if (!(rx->flags & IEEE80211_TXRXD_RXRA_MATCH))
1435                 return TXRX_DROP;
1436
1437         sdata = IEEE80211_DEV_TO_SUB_IF(rx->dev);
1438         if ((sdata->vif.type == IEEE80211_IF_TYPE_STA ||
1439              sdata->vif.type == IEEE80211_IF_TYPE_IBSS) &&
1440             !(sdata->flags & IEEE80211_SDATA_USERSPACE_MLME))
1441                 ieee80211_sta_rx_mgmt(rx->dev, rx->skb, rx->u.rx.status);
1442         else
1443                 return TXRX_DROP;
1444
1445         return TXRX_QUEUED;
1446 }
1447
1448 static inline ieee80211_txrx_result __ieee80211_invoke_rx_handlers(
1449                                 struct ieee80211_local *local,
1450                                 ieee80211_rx_handler *handlers,
1451                                 struct ieee80211_txrx_data *rx,
1452                                 struct sta_info *sta)
1453 {
1454         ieee80211_rx_handler *handler;
1455         ieee80211_txrx_result res = TXRX_DROP;
1456
1457         for (handler = handlers; *handler != NULL; handler++) {
1458                 res = (*handler)(rx);
1459
1460                 switch (res) {
1461                 case TXRX_CONTINUE:
1462                         continue;
1463                 case TXRX_DROP:
1464                         I802_DEBUG_INC(local->rx_handlers_drop);
1465                         if (sta)
1466                                 sta->rx_dropped++;
1467                         break;
1468                 case TXRX_QUEUED:
1469                         I802_DEBUG_INC(local->rx_handlers_queued);
1470                         break;
1471                 }
1472                 break;
1473         }
1474
1475         if (res == TXRX_DROP)
1476                 dev_kfree_skb(rx->skb);
1477         return res;
1478 }
1479
1480 static inline void ieee80211_invoke_rx_handlers(struct ieee80211_local *local,
1481                                                 ieee80211_rx_handler *handlers,
1482                                                 struct ieee80211_txrx_data *rx,
1483                                                 struct sta_info *sta)
1484 {
1485         if (__ieee80211_invoke_rx_handlers(local, handlers, rx, sta) ==
1486             TXRX_CONTINUE)
1487                 dev_kfree_skb(rx->skb);
1488 }
1489
1490 static void ieee80211_rx_michael_mic_report(struct net_device *dev,
1491                                             struct ieee80211_hdr *hdr,
1492                                             struct sta_info *sta,
1493                                             struct ieee80211_txrx_data *rx)
1494 {
1495         int keyidx, hdrlen;
1496         DECLARE_MAC_BUF(mac);
1497         DECLARE_MAC_BUF(mac2);
1498
1499         hdrlen = ieee80211_get_hdrlen_from_skb(rx->skb);
1500         if (rx->skb->len >= hdrlen + 4)
1501                 keyidx = rx->skb->data[hdrlen + 3] >> 6;
1502         else
1503                 keyidx = -1;
1504
1505         if (net_ratelimit())
1506                 printk(KERN_DEBUG "%s: TKIP hwaccel reported Michael MIC "
1507                        "failure from %s to %s keyidx=%d\n",
1508                        dev->name, print_mac(mac, hdr->addr2),
1509                        print_mac(mac2, hdr->addr1), keyidx);
1510
1511         if (!sta) {
1512                 /*
1513                  * Some hardware seem to generate incorrect Michael MIC
1514                  * reports; ignore them to avoid triggering countermeasures.
1515                  */
1516                 if (net_ratelimit())
1517                         printk(KERN_DEBUG "%s: ignored spurious Michael MIC "
1518                                "error for unknown address %s\n",
1519                                dev->name, print_mac(mac, hdr->addr2));
1520                 goto ignore;
1521         }
1522
1523         if (!(rx->fc & IEEE80211_FCTL_PROTECTED)) {
1524                 if (net_ratelimit())
1525                         printk(KERN_DEBUG "%s: ignored spurious Michael MIC "
1526                                "error for a frame with no PROTECTED flag (src "
1527                                "%s)\n", dev->name, print_mac(mac, hdr->addr2));
1528                 goto ignore;
1529         }
1530
1531         if (rx->sdata->vif.type == IEEE80211_IF_TYPE_AP && keyidx) {
1532                 /*
1533                  * APs with pairwise keys should never receive Michael MIC
1534                  * errors for non-zero keyidx because these are reserved for
1535                  * group keys and only the AP is sending real multicast
1536                  * frames in the BSS.
1537                  */
1538                 if (net_ratelimit())
1539                         printk(KERN_DEBUG "%s: ignored Michael MIC error for "
1540                                "a frame with non-zero keyidx (%d)"
1541                                " (src %s)\n", dev->name, keyidx,
1542                                print_mac(mac, hdr->addr2));
1543                 goto ignore;
1544         }
1545
1546         if ((rx->fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_DATA &&
1547             ((rx->fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_MGMT ||
1548              (rx->fc & IEEE80211_FCTL_STYPE) != IEEE80211_STYPE_AUTH)) {
1549                 if (net_ratelimit())
1550                         printk(KERN_DEBUG "%s: ignored spurious Michael MIC "
1551                                "error for a frame that cannot be encrypted "
1552                                "(fc=0x%04x) (src %s)\n",
1553                                dev->name, rx->fc, print_mac(mac, hdr->addr2));
1554                 goto ignore;
1555         }
1556
1557         mac80211_ev_michael_mic_failure(rx->dev, keyidx, hdr);
1558  ignore:
1559         dev_kfree_skb(rx->skb);
1560         rx->skb = NULL;
1561 }
1562
1563 ieee80211_rx_handler ieee80211_rx_handlers[] =
1564 {
1565         ieee80211_rx_h_if_stats,
1566         ieee80211_rx_h_passive_scan,
1567         ieee80211_rx_h_check,
1568         ieee80211_rx_h_decrypt,
1569         ieee80211_rx_h_sta_process,
1570         ieee80211_rx_h_defragment,
1571         ieee80211_rx_h_ps_poll,
1572         ieee80211_rx_h_michael_mic_verify,
1573         /* this must be after decryption - so header is counted in MPDU mic
1574          * must be before pae and data, so QOS_DATA format frames
1575          * are not passed to user space by these functions
1576          */
1577         ieee80211_rx_h_remove_qos_control,
1578         ieee80211_rx_h_amsdu,
1579         ieee80211_rx_h_data,
1580         ieee80211_rx_h_ctrl,
1581         ieee80211_rx_h_mgmt,
1582         NULL
1583 };
1584
1585 /* main receive path */
1586
1587 static int prepare_for_handlers(struct ieee80211_sub_if_data *sdata,
1588                                 u8 *bssid, struct ieee80211_txrx_data *rx,
1589                                 struct ieee80211_hdr *hdr)
1590 {
1591         int multicast = is_multicast_ether_addr(hdr->addr1);
1592
1593         switch (sdata->vif.type) {
1594         case IEEE80211_IF_TYPE_STA:
1595                 if (!bssid)
1596                         return 0;
1597                 if (!ieee80211_bssid_match(bssid, sdata->u.sta.bssid)) {
1598                         if (!(rx->flags & IEEE80211_TXRXD_RXIN_SCAN))
1599                                 return 0;
1600                         rx->flags &= ~IEEE80211_TXRXD_RXRA_MATCH;
1601                 } else if (!multicast &&
1602                            compare_ether_addr(sdata->dev->dev_addr,
1603                                               hdr->addr1) != 0) {
1604                         if (!(sdata->dev->flags & IFF_PROMISC))
1605                                 return 0;
1606                         rx->flags &= ~IEEE80211_TXRXD_RXRA_MATCH;
1607                 }
1608                 break;
1609         case IEEE80211_IF_TYPE_IBSS:
1610                 if (!bssid)
1611                         return 0;
1612                 if (!ieee80211_bssid_match(bssid, sdata->u.sta.bssid)) {
1613                         if (!(rx->flags & IEEE80211_TXRXD_RXIN_SCAN))
1614                                 return 0;
1615                         rx->flags &= ~IEEE80211_TXRXD_RXRA_MATCH;
1616                 } else if (!multicast &&
1617                            compare_ether_addr(sdata->dev->dev_addr,
1618                                               hdr->addr1) != 0) {
1619                         if (!(sdata->dev->flags & IFF_PROMISC))
1620                                 return 0;
1621                         rx->flags &= ~IEEE80211_TXRXD_RXRA_MATCH;
1622                 } else if (!rx->sta)
1623                         rx->sta = ieee80211_ibss_add_sta(sdata->dev, rx->skb,
1624                                                          bssid, hdr->addr2);
1625                 break;
1626         case IEEE80211_IF_TYPE_VLAN:
1627         case IEEE80211_IF_TYPE_AP:
1628                 if (!bssid) {
1629                         if (compare_ether_addr(sdata->dev->dev_addr,
1630                                                hdr->addr1))
1631                                 return 0;
1632                 } else if (!ieee80211_bssid_match(bssid,
1633                                         sdata->dev->dev_addr)) {
1634                         if (!(rx->flags & IEEE80211_TXRXD_RXIN_SCAN))
1635                                 return 0;
1636                         rx->flags &= ~IEEE80211_TXRXD_RXRA_MATCH;
1637                 }
1638                 if (sdata->dev == sdata->local->mdev &&
1639                     !(rx->flags & IEEE80211_TXRXD_RXIN_SCAN))
1640                         /* do not receive anything via
1641                          * master device when not scanning */
1642                         return 0;
1643                 break;
1644         case IEEE80211_IF_TYPE_WDS:
1645                 if (bssid ||
1646                     (rx->fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_DATA)
1647                         return 0;
1648                 if (compare_ether_addr(sdata->u.wds.remote_addr, hdr->addr2))
1649                         return 0;
1650                 break;
1651         case IEEE80211_IF_TYPE_MNTR:
1652                 /* take everything */
1653                 break;
1654         case IEEE80211_IF_TYPE_INVALID:
1655                 /* should never get here */
1656                 WARN_ON(1);
1657                 break;
1658         }
1659
1660         return 1;
1661 }
1662
1663 /*
1664  * This is the actual Rx frames handler. as it blongs to Rx path it must
1665  * be called with rcu_read_lock protection.
1666  */
1667 static void __ieee80211_rx_handle_packet(struct ieee80211_hw *hw,
1668                                          struct sk_buff *skb,
1669                                          struct ieee80211_rx_status *status,
1670                                          u32 load)
1671 {
1672         struct ieee80211_local *local = hw_to_local(hw);
1673         struct ieee80211_sub_if_data *sdata;
1674         struct sta_info *sta;
1675         struct ieee80211_hdr *hdr;
1676         struct ieee80211_txrx_data rx;
1677         u16 type;
1678         int prepares;
1679         struct ieee80211_sub_if_data *prev = NULL;
1680         struct sk_buff *skb_new;
1681         u8 *bssid;
1682         int hdrlen;
1683
1684         hdr = (struct ieee80211_hdr *) skb->data;
1685         memset(&rx, 0, sizeof(rx));
1686         rx.skb = skb;
1687         rx.local = local;
1688
1689         rx.u.rx.status = status;
1690         rx.u.rx.load = load;
1691         rx.fc = le16_to_cpu(hdr->frame_control);
1692         type = rx.fc & IEEE80211_FCTL_FTYPE;
1693
1694         /*
1695          * Drivers are required to align the payload data to a four-byte
1696          * boundary, so the last two bits of the address where it starts
1697          * may not be set. The header is required to be directly before
1698          * the payload data, padding like atheros hardware adds which is
1699          * inbetween the 802.11 header and the payload is not supported,
1700          * the driver is required to move the 802.11 header further back
1701          * in that case.
1702          */
1703         hdrlen = ieee80211_get_hdrlen(rx.fc);
1704         WARN_ON_ONCE(((unsigned long)(skb->data + hdrlen)) & 3);
1705
1706         if (type == IEEE80211_FTYPE_DATA || type == IEEE80211_FTYPE_MGMT)
1707                 local->dot11ReceivedFragmentCount++;
1708
1709         sta = rx.sta = sta_info_get(local, hdr->addr2);
1710         if (sta) {
1711                 rx.dev = rx.sta->dev;
1712                 rx.sdata = IEEE80211_DEV_TO_SUB_IF(rx.dev);
1713         }
1714
1715         if ((status->flag & RX_FLAG_MMIC_ERROR)) {
1716                 ieee80211_rx_michael_mic_report(local->mdev, hdr, sta, &rx);
1717                 goto end;
1718         }
1719
1720         if (unlikely(local->sta_sw_scanning || local->sta_hw_scanning))
1721                 rx.flags |= IEEE80211_TXRXD_RXIN_SCAN;
1722
1723         if (__ieee80211_invoke_rx_handlers(local, local->rx_pre_handlers, &rx,
1724                                            sta) != TXRX_CONTINUE)
1725                 goto end;
1726         skb = rx.skb;
1727
1728         if (sta && !(sta->flags & (WLAN_STA_WDS | WLAN_STA_ASSOC_AP)) &&
1729             !atomic_read(&local->iff_promiscs) &&
1730             !is_multicast_ether_addr(hdr->addr1)) {
1731                 rx.flags |= IEEE80211_TXRXD_RXRA_MATCH;
1732                 ieee80211_invoke_rx_handlers(local, local->rx_handlers, &rx,
1733                                              rx.sta);
1734                 sta_info_put(sta);
1735                 return;
1736         }
1737
1738         list_for_each_entry_rcu(sdata, &local->interfaces, list) {
1739                 if (!netif_running(sdata->dev))
1740                         continue;
1741
1742                 if (sdata->vif.type == IEEE80211_IF_TYPE_MNTR)
1743                         continue;
1744
1745                 bssid = ieee80211_get_bssid(hdr, skb->len, sdata->vif.type);
1746                 rx.flags |= IEEE80211_TXRXD_RXRA_MATCH;
1747                 prepares = prepare_for_handlers(sdata, bssid, &rx, hdr);
1748                 /* prepare_for_handlers can change sta */
1749                 sta = rx.sta;
1750
1751                 if (!prepares)
1752                         continue;
1753
1754                 /*
1755                  * frame is destined for this interface, but if it's not
1756                  * also for the previous one we handle that after the
1757                  * loop to avoid copying the SKB once too much
1758                  */
1759
1760                 if (!prev) {
1761                         prev = sdata;
1762                         continue;
1763                 }
1764
1765                 /*
1766                  * frame was destined for the previous interface
1767                  * so invoke RX handlers for it
1768                  */
1769
1770                 skb_new = skb_copy(skb, GFP_ATOMIC);
1771                 if (!skb_new) {
1772                         if (net_ratelimit())
1773                                 printk(KERN_DEBUG "%s: failed to copy "
1774                                        "multicast frame for %s",
1775                                        wiphy_name(local->hw.wiphy),
1776                                        prev->dev->name);
1777                         continue;
1778                 }
1779                 rx.fc = le16_to_cpu(hdr->frame_control);
1780                 rx.skb = skb_new;
1781                 rx.dev = prev->dev;
1782                 rx.sdata = prev;
1783                 ieee80211_invoke_rx_handlers(local, local->rx_handlers,
1784                                              &rx, sta);
1785                 prev = sdata;
1786         }
1787         if (prev) {
1788                 rx.fc = le16_to_cpu(hdr->frame_control);
1789                 rx.skb = skb;
1790                 rx.dev = prev->dev;
1791                 rx.sdata = prev;
1792                 ieee80211_invoke_rx_handlers(local, local->rx_handlers,
1793                                              &rx, sta);
1794         } else
1795                 dev_kfree_skb(skb);
1796
1797  end:
1798         if (sta)
1799                 sta_info_put(sta);
1800 }
1801
1802 #define SEQ_MODULO 0x1000
1803 #define SEQ_MASK   0xfff
1804
1805 static inline int seq_less(u16 sq1, u16 sq2)
1806 {
1807         return (((sq1 - sq2) & SEQ_MASK) > (SEQ_MODULO >> 1));
1808 }
1809
1810 static inline u16 seq_inc(u16 sq)
1811 {
1812         return ((sq + 1) & SEQ_MASK);
1813 }
1814
1815 static inline u16 seq_sub(u16 sq1, u16 sq2)
1816 {
1817         return ((sq1 - sq2) & SEQ_MASK);
1818 }
1819
1820
1821 /*
1822  * As it function blongs to Rx path it must be called with
1823  * the proper rcu_read_lock protection for its flow.
1824  */
1825 u8 ieee80211_sta_manage_reorder_buf(struct ieee80211_hw *hw,
1826                                 struct tid_ampdu_rx *tid_agg_rx,
1827                                 struct sk_buff *skb, u16 mpdu_seq_num,
1828                                 int bar_req)
1829 {
1830         struct ieee80211_local *local = hw_to_local(hw);
1831         struct ieee80211_rx_status status;
1832         u16 head_seq_num, buf_size;
1833         int index;
1834         u32 pkt_load;
1835
1836         buf_size = tid_agg_rx->buf_size;
1837         head_seq_num = tid_agg_rx->head_seq_num;
1838
1839         /* frame with out of date sequence number */
1840         if (seq_less(mpdu_seq_num, head_seq_num)) {
1841                 dev_kfree_skb(skb);
1842                 return 1;
1843         }
1844
1845         /* if frame sequence number exceeds our buffering window size or
1846          * block Ack Request arrived - release stored frames */
1847         if ((!seq_less(mpdu_seq_num, head_seq_num + buf_size)) || (bar_req)) {
1848                 /* new head to the ordering buffer */
1849                 if (bar_req)
1850                         head_seq_num = mpdu_seq_num;
1851                 else
1852                         head_seq_num =
1853                                 seq_inc(seq_sub(mpdu_seq_num, buf_size));
1854                 /* release stored frames up to new head to stack */
1855                 while (seq_less(tid_agg_rx->head_seq_num, head_seq_num)) {
1856                         index = seq_sub(tid_agg_rx->head_seq_num,
1857                                 tid_agg_rx->ssn)
1858                                 % tid_agg_rx->buf_size;
1859
1860                         if (tid_agg_rx->reorder_buf[index]) {
1861                                 /* release the reordered frames to stack */
1862                                 memcpy(&status,
1863                                         tid_agg_rx->reorder_buf[index]->cb,
1864                                         sizeof(status));
1865                                 pkt_load = ieee80211_rx_load_stats(local,
1866                                                 tid_agg_rx->reorder_buf[index],
1867                                                 &status);
1868                                 __ieee80211_rx_handle_packet(hw,
1869                                         tid_agg_rx->reorder_buf[index],
1870                                         &status, pkt_load);
1871                                 tid_agg_rx->stored_mpdu_num--;
1872                                 tid_agg_rx->reorder_buf[index] = NULL;
1873                         }
1874                         tid_agg_rx->head_seq_num =
1875                                 seq_inc(tid_agg_rx->head_seq_num);
1876                 }
1877                 if (bar_req)
1878                         return 1;
1879         }
1880
1881         /* now the new frame is always in the range of the reordering */
1882         /* buffer window */
1883         index = seq_sub(mpdu_seq_num, tid_agg_rx->ssn)
1884                                 % tid_agg_rx->buf_size;
1885         /* check if we already stored this frame */
1886         if (tid_agg_rx->reorder_buf[index]) {
1887                 dev_kfree_skb(skb);
1888                 return 1;
1889         }
1890
1891         /* if arrived mpdu is in the right order and nothing else stored */
1892         /* release it immediately */
1893         if (mpdu_seq_num == tid_agg_rx->head_seq_num &&
1894                         tid_agg_rx->stored_mpdu_num == 0) {
1895                 tid_agg_rx->head_seq_num =
1896                         seq_inc(tid_agg_rx->head_seq_num);
1897                 return 0;
1898         }
1899
1900         /* put the frame in the reordering buffer */
1901         tid_agg_rx->reorder_buf[index] = skb;
1902         tid_agg_rx->stored_mpdu_num++;
1903         /* release the buffer until next missing frame */
1904         index = seq_sub(tid_agg_rx->head_seq_num, tid_agg_rx->ssn)
1905                                                 % tid_agg_rx->buf_size;
1906         while (tid_agg_rx->reorder_buf[index]) {
1907                 /* release the reordered frame back to stack */
1908                 memcpy(&status, tid_agg_rx->reorder_buf[index]->cb,
1909                         sizeof(status));
1910                 pkt_load = ieee80211_rx_load_stats(local,
1911                                         tid_agg_rx->reorder_buf[index],
1912                                         &status);
1913                 __ieee80211_rx_handle_packet(hw, tid_agg_rx->reorder_buf[index],
1914                                                 &status, pkt_load);
1915                 tid_agg_rx->stored_mpdu_num--;
1916                 tid_agg_rx->reorder_buf[index] = NULL;
1917                 tid_agg_rx->head_seq_num = seq_inc(tid_agg_rx->head_seq_num);
1918                 index = seq_sub(tid_agg_rx->head_seq_num,
1919                         tid_agg_rx->ssn) % tid_agg_rx->buf_size;
1920         }
1921         return 1;
1922 }
1923
1924 static u8 ieee80211_rx_reorder_ampdu(struct ieee80211_local *local,
1925                                      struct sk_buff *skb)
1926 {
1927         struct ieee80211_hw *hw = &local->hw;
1928         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
1929         struct sta_info *sta;
1930         struct tid_ampdu_rx *tid_agg_rx;
1931         u16 fc, sc;
1932         u16 mpdu_seq_num;
1933         u8 ret = 0, *qc;
1934         int tid;
1935
1936         sta = sta_info_get(local, hdr->addr2);
1937         if (!sta)
1938                 return ret;
1939
1940         fc = le16_to_cpu(hdr->frame_control);
1941
1942         /* filter the QoS data rx stream according to
1943          * STA/TID and check if this STA/TID is on aggregation */
1944         if (!WLAN_FC_IS_QOS_DATA(fc))
1945                 goto end_reorder;
1946
1947         qc = skb->data + ieee80211_get_hdrlen(fc) - QOS_CONTROL_LEN;
1948         tid = qc[0] & QOS_CONTROL_TID_MASK;
1949         tid_agg_rx = &(sta->ampdu_mlme.tid_rx[tid]);
1950
1951         if (tid_agg_rx->state != HT_AGG_STATE_OPERATIONAL)
1952                 goto end_reorder;
1953
1954         /* null data frames are excluded */
1955         if (unlikely(fc & IEEE80211_STYPE_QOS_NULLFUNC))
1956                 goto end_reorder;
1957
1958         /* new un-ordered ampdu frame - process it */
1959
1960         /* reset session timer */
1961         if (tid_agg_rx->timeout) {
1962                 unsigned long expires =
1963                         jiffies + (tid_agg_rx->timeout / 1000) * HZ;
1964                 mod_timer(&tid_agg_rx->session_timer, expires);
1965         }
1966
1967         /* if this mpdu is fragmented - terminate rx aggregation session */
1968         sc = le16_to_cpu(hdr->seq_ctrl);
1969         if (sc & IEEE80211_SCTL_FRAG) {
1970                 ieee80211_sta_stop_rx_ba_session(sta->dev, sta->addr,
1971                         tid, 0, WLAN_REASON_QSTA_REQUIRE_SETUP);
1972                 ret = 1;
1973                 goto end_reorder;
1974         }
1975
1976         /* according to mpdu sequence number deal with reordering buffer */
1977         mpdu_seq_num = (sc & IEEE80211_SCTL_SEQ) >> 4;
1978         ret = ieee80211_sta_manage_reorder_buf(hw, tid_agg_rx, skb,
1979                                                 mpdu_seq_num, 0);
1980 end_reorder:
1981         if (sta)
1982                 sta_info_put(sta);
1983         return ret;
1984 }
1985
1986 /*
1987  * This is the receive path handler. It is called by a low level driver when an
1988  * 802.11 MPDU is received from the hardware.
1989  */
1990 void __ieee80211_rx(struct ieee80211_hw *hw, struct sk_buff *skb,
1991                     struct ieee80211_rx_status *status)
1992 {
1993         struct ieee80211_local *local = hw_to_local(hw);
1994         u32 pkt_load;
1995
1996         /*
1997          * key references and virtual interfaces are protected using RCU
1998          * and this requires that we are in a read-side RCU section during
1999          * receive processing
2000          */
2001         rcu_read_lock();
2002
2003         /*
2004          * Frames with failed FCS/PLCP checksum are not returned,
2005          * all other frames are returned without radiotap header
2006          * if it was previously present.
2007          * Also, frames with less than 16 bytes are dropped.
2008          */
2009         skb = ieee80211_rx_monitor(local, skb, status);
2010         if (!skb) {
2011                 rcu_read_unlock();
2012                 return;
2013         }
2014
2015         pkt_load = ieee80211_rx_load_stats(local, skb, status);
2016         local->channel_use_raw += pkt_load;
2017
2018         if (!ieee80211_rx_reorder_ampdu(local, skb))
2019                 __ieee80211_rx_handle_packet(hw, skb, status, pkt_load);
2020
2021         rcu_read_unlock();
2022 }
2023 EXPORT_SYMBOL(__ieee80211_rx);
2024
2025 /* This is a version of the rx handler that can be called from hard irq
2026  * context. Post the skb on the queue and schedule the tasklet */
2027 void ieee80211_rx_irqsafe(struct ieee80211_hw *hw, struct sk_buff *skb,
2028                           struct ieee80211_rx_status *status)
2029 {
2030         struct ieee80211_local *local = hw_to_local(hw);
2031
2032         BUILD_BUG_ON(sizeof(struct ieee80211_rx_status) > sizeof(skb->cb));
2033
2034         skb->dev = local->mdev;
2035         /* copy status into skb->cb for use by tasklet */
2036         memcpy(skb->cb, status, sizeof(*status));
2037         skb->pkt_type = IEEE80211_RX_MSG;
2038         skb_queue_tail(&local->skb_queue, skb);
2039         tasklet_schedule(&local->tasklet);
2040 }
2041 EXPORT_SYMBOL(ieee80211_rx_irqsafe);