mac80211: remove rx/tx_data->fc member
[linux-2.6] / net / mac80211 / rx.c
1 /*
2  * Copyright 2002-2005, Instant802 Networks, Inc.
3  * Copyright 2005-2006, Devicescape Software, Inc.
4  * Copyright 2006-2007  Jiri Benc <jbenc@suse.cz>
5  * Copyright 2007       Johannes Berg <johannes@sipsolutions.net>
6  *
7  * This program is free software; you can redistribute it and/or modify
8  * it under the terms of the GNU General Public License version 2 as
9  * published by the Free Software Foundation.
10  */
11
12 #include <linux/jiffies.h>
13 #include <linux/kernel.h>
14 #include <linux/skbuff.h>
15 #include <linux/netdevice.h>
16 #include <linux/etherdevice.h>
17 #include <linux/rcupdate.h>
18 #include <net/mac80211.h>
19 #include <net/ieee80211_radiotap.h>
20
21 #include "ieee80211_i.h"
22 #include "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         if (status->flag & RX_FLAG_SHORTPRE)
147                 *pos |= IEEE80211_RADIOTAP_F_SHORTPRE;
148         pos++;
149
150         /* IEEE80211_RADIOTAP_RATE */
151         *pos = rate->bitrate / 5;
152         pos++;
153
154         /* IEEE80211_RADIOTAP_CHANNEL */
155         *(__le16 *)pos = cpu_to_le16(status->freq);
156         pos += 2;
157         if (status->band == IEEE80211_BAND_5GHZ)
158                 *(__le16 *)pos = cpu_to_le16(IEEE80211_CHAN_OFDM |
159                                              IEEE80211_CHAN_5GHZ);
160         else if (rate->flags & IEEE80211_RATE_ERP_G)
161                 *(__le16 *)pos = cpu_to_le16(IEEE80211_CHAN_OFDM |
162                                              IEEE80211_CHAN_2GHZ);
163         else
164                 *(__le16 *)pos = cpu_to_le16(IEEE80211_CHAN_CCK |
165                                              IEEE80211_CHAN_2GHZ);
166         pos += 2;
167
168         /* IEEE80211_RADIOTAP_DBM_ANTSIGNAL */
169         if (local->hw.flags & IEEE80211_HW_SIGNAL_DBM) {
170                 *pos = status->signal;
171                 rthdr->it_present |=
172                         cpu_to_le32(1 << IEEE80211_RADIOTAP_DBM_ANTSIGNAL);
173                 pos++;
174         }
175
176         /* IEEE80211_RADIOTAP_DBM_ANTNOISE */
177         if (local->hw.flags & IEEE80211_HW_NOISE_DBM) {
178                 *pos = status->noise;
179                 rthdr->it_present |=
180                         cpu_to_le32(1 << IEEE80211_RADIOTAP_DBM_ANTNOISE);
181                 pos++;
182         }
183
184         /* IEEE80211_RADIOTAP_LOCK_QUALITY is missing */
185
186         /* IEEE80211_RADIOTAP_ANTENNA */
187         *pos = status->antenna;
188         pos++;
189
190         /* IEEE80211_RADIOTAP_DB_ANTSIGNAL */
191         if (local->hw.flags & IEEE80211_HW_SIGNAL_DB) {
192                 *pos = status->signal;
193                 rthdr->it_present |=
194                         cpu_to_le32(1 << IEEE80211_RADIOTAP_DB_ANTSIGNAL);
195                 pos++;
196         }
197
198         /* IEEE80211_RADIOTAP_DB_ANTNOISE is not used */
199
200         /* IEEE80211_RADIOTAP_RX_FLAGS */
201         /* ensure 2 byte alignment for the 2 byte field as required */
202         if ((pos - (unsigned char *)rthdr) & 1)
203                 pos++;
204         /* FIXME: when radiotap gets a 'bad PLCP' flag use it here */
205         if (status->flag & (RX_FLAG_FAILED_FCS_CRC | RX_FLAG_FAILED_PLCP_CRC))
206                 *(__le16 *)pos |= cpu_to_le16(IEEE80211_RADIOTAP_F_RX_BADFCS);
207         pos += 2;
208 }
209
210 /*
211  * This function copies a received frame to all monitor interfaces and
212  * returns a cleaned-up SKB that no longer includes the FCS nor the
213  * radiotap header the driver might have added.
214  */
215 static struct sk_buff *
216 ieee80211_rx_monitor(struct ieee80211_local *local, struct sk_buff *origskb,
217                      struct ieee80211_rx_status *status,
218                      struct ieee80211_rate *rate)
219 {
220         struct ieee80211_sub_if_data *sdata;
221         int needed_headroom = 0;
222         struct sk_buff *skb, *skb2;
223         struct net_device *prev_dev = NULL;
224         int present_fcs_len = 0;
225         int rtap_len = 0;
226
227         /*
228          * First, we may need to make a copy of the skb because
229          *  (1) we need to modify it for radiotap (if not present), and
230          *  (2) the other RX handlers will modify the skb we got.
231          *
232          * We don't need to, of course, if we aren't going to return
233          * the SKB because it has a bad FCS/PLCP checksum.
234          */
235         if (status->flag & RX_FLAG_RADIOTAP)
236                 rtap_len = ieee80211_get_radiotap_len(origskb->data);
237         else
238                 /* room for the radiotap header based on driver features */
239                 needed_headroom = ieee80211_rx_radiotap_len(local, status);
240
241         if (local->hw.flags & IEEE80211_HW_RX_INCLUDES_FCS)
242                 present_fcs_len = FCS_LEN;
243
244         if (!local->monitors) {
245                 if (should_drop_frame(status, origskb, present_fcs_len,
246                                       rtap_len)) {
247                         dev_kfree_skb(origskb);
248                         return NULL;
249                 }
250
251                 return remove_monitor_info(local, origskb, rtap_len);
252         }
253
254         if (should_drop_frame(status, origskb, present_fcs_len, rtap_len)) {
255                 /* only need to expand headroom if necessary */
256                 skb = origskb;
257                 origskb = NULL;
258
259                 /*
260                  * This shouldn't trigger often because most devices have an
261                  * RX header they pull before we get here, and that should
262                  * be big enough for our radiotap information. We should
263                  * probably export the length to drivers so that we can have
264                  * them allocate enough headroom to start with.
265                  */
266                 if (skb_headroom(skb) < needed_headroom &&
267                     pskb_expand_head(skb, needed_headroom, 0, GFP_ATOMIC)) {
268                         dev_kfree_skb(skb);
269                         return NULL;
270                 }
271         } else {
272                 /*
273                  * Need to make a copy and possibly remove radiotap header
274                  * and FCS from the original.
275                  */
276                 skb = skb_copy_expand(origskb, needed_headroom, 0, GFP_ATOMIC);
277
278                 origskb = remove_monitor_info(local, origskb, rtap_len);
279
280                 if (!skb)
281                         return origskb;
282         }
283
284         /* if necessary, prepend radiotap information */
285         if (!(status->flag & RX_FLAG_RADIOTAP))
286                 ieee80211_add_rx_radiotap_header(local, skb, status, rate,
287                                                  needed_headroom);
288
289         skb_reset_mac_header(skb);
290         skb->ip_summed = CHECKSUM_UNNECESSARY;
291         skb->pkt_type = PACKET_OTHERHOST;
292         skb->protocol = htons(ETH_P_802_2);
293
294         list_for_each_entry_rcu(sdata, &local->interfaces, list) {
295                 if (!netif_running(sdata->dev))
296                         continue;
297
298                 if (sdata->vif.type != IEEE80211_IF_TYPE_MNTR)
299                         continue;
300
301                 if (sdata->u.mntr_flags & MONITOR_FLAG_COOK_FRAMES)
302                         continue;
303
304                 if (prev_dev) {
305                         skb2 = skb_clone(skb, GFP_ATOMIC);
306                         if (skb2) {
307                                 skb2->dev = prev_dev;
308                                 netif_rx(skb2);
309                         }
310                 }
311
312                 prev_dev = sdata->dev;
313                 sdata->dev->stats.rx_packets++;
314                 sdata->dev->stats.rx_bytes += skb->len;
315         }
316
317         if (prev_dev) {
318                 skb->dev = prev_dev;
319                 netif_rx(skb);
320         } else
321                 dev_kfree_skb(skb);
322
323         return origskb;
324 }
325
326
327 static void ieee80211_parse_qos(struct ieee80211_rx_data *rx)
328 {
329         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
330         int tid;
331
332         /* does the frame have a qos control field? */
333         if (ieee80211_is_data_qos(hdr->frame_control)) {
334                 u8 *qc = ieee80211_get_qos_ctl(hdr);
335                 /* frame has qos control */
336                 tid = *qc & IEEE80211_QOS_CTL_TID_MASK;
337                 if (*qc & IEEE80211_QOS_CONTROL_A_MSDU_PRESENT)
338                         rx->flags |= IEEE80211_RX_AMSDU;
339                 else
340                         rx->flags &= ~IEEE80211_RX_AMSDU;
341         } else {
342                 /*
343                  * IEEE 802.11-2007, 7.1.3.4.1 ("Sequence Number field"):
344                  *
345                  *      Sequence numbers for management frames, QoS data
346                  *      frames with a broadcast/multicast address in the
347                  *      Address 1 field, and all non-QoS data frames sent
348                  *      by QoS STAs are assigned using an additional single
349                  *      modulo-4096 counter, [...]
350                  *
351                  * We also use that counter for non-QoS STAs.
352                  */
353                 tid = NUM_RX_DATA_QUEUES - 1;
354         }
355
356         rx->queue = tid;
357         /* Set skb->priority to 1d tag if highest order bit of TID is not set.
358          * For now, set skb->priority to 0 for other cases. */
359         rx->skb->priority = (tid > 7) ? 0 : tid;
360 }
361
362 static void ieee80211_verify_ip_alignment(struct ieee80211_rx_data *rx)
363 {
364 #ifdef CONFIG_MAC80211_DEBUG_PACKET_ALIGNMENT
365         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
366         int hdrlen;
367
368         if (!ieee80211_is_data_present(hdr->frame_control))
369                 return;
370
371         /*
372          * Drivers are required to align the payload data in a way that
373          * guarantees that the contained IP header is aligned to a four-
374          * byte boundary. In the case of regular frames, this simply means
375          * aligning the payload to a four-byte boundary (because either
376          * the IP header is directly contained, or IV/RFC1042 headers that
377          * have a length divisible by four are in front of it.
378          *
379          * With A-MSDU frames, however, the payload data address must
380          * yield two modulo four because there are 14-byte 802.3 headers
381          * within the A-MSDU frames that push the IP header further back
382          * to a multiple of four again. Thankfully, the specs were sane
383          * enough this time around to require padding each A-MSDU subframe
384          * to a length that is a multiple of four.
385          *
386          * Padding like atheros hardware adds which is inbetween the 802.11
387          * header and the payload is not supported, the driver is required
388          * to move the 802.11 header further back in that case.
389          */
390         hdrlen = ieee80211_hdrlen(hdr->frame_control);
391         if (rx->flags & IEEE80211_RX_AMSDU)
392                 hdrlen += ETH_HLEN;
393         WARN_ON_ONCE(((unsigned long)(rx->skb->data + hdrlen)) & 3);
394 #endif
395 }
396
397
398 /* rx handlers */
399
400 static ieee80211_rx_result debug_noinline
401 ieee80211_rx_h_passive_scan(struct ieee80211_rx_data *rx)
402 {
403         struct ieee80211_local *local = rx->local;
404         struct sk_buff *skb = rx->skb;
405
406         if (unlikely(local->sta_hw_scanning))
407                 return ieee80211_sta_rx_scan(rx->dev, skb, rx->status);
408
409         if (unlikely(local->sta_sw_scanning)) {
410                 /* drop all the other packets during a software scan anyway */
411                 if (ieee80211_sta_rx_scan(rx->dev, skb, rx->status)
412                     != RX_QUEUED)
413                         dev_kfree_skb(skb);
414                 return RX_QUEUED;
415         }
416
417         if (unlikely(rx->flags & IEEE80211_RX_IN_SCAN)) {
418                 /* scanning finished during invoking of handlers */
419                 I802_DEBUG_INC(local->rx_handlers_drop_passive_scan);
420                 return RX_DROP_UNUSABLE;
421         }
422
423         return RX_CONTINUE;
424 }
425
426 static ieee80211_rx_result
427 ieee80211_rx_mesh_check(struct ieee80211_rx_data *rx)
428 {
429         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
430         unsigned int hdrlen = ieee80211_hdrlen(hdr->frame_control);
431
432         if (ieee80211_is_data(hdr->frame_control)) {
433                 if (!ieee80211_has_a4(hdr->frame_control))
434                         return RX_DROP_MONITOR;
435                 if (memcmp(hdr->addr4, rx->dev->dev_addr, ETH_ALEN) == 0)
436                         return RX_DROP_MONITOR;
437         }
438
439         /* If there is not an established peer link and this is not a peer link
440          * establisment frame, beacon or probe, drop the frame.
441          */
442
443         if (!rx->sta || sta_plink_state(rx->sta) != PLINK_ESTAB) {
444                 struct ieee80211_mgmt *mgmt;
445
446                 if (!ieee80211_is_mgmt(hdr->frame_control))
447                         return RX_DROP_MONITOR;
448
449                 if (ieee80211_is_action(hdr->frame_control)) {
450                         mgmt = (struct ieee80211_mgmt *)hdr;
451                         if (mgmt->u.action.category != PLINK_CATEGORY)
452                                 return RX_DROP_MONITOR;
453                         return RX_CONTINUE;
454                 }
455
456                 if (ieee80211_is_probe_req(hdr->frame_control) ||
457                     ieee80211_is_probe_resp(hdr->frame_control) ||
458                     ieee80211_is_beacon(hdr->frame_control))
459                         return RX_CONTINUE;
460
461                 return RX_DROP_MONITOR;
462
463         }
464
465 #define msh_h_get(h, l) ((struct ieee80211s_hdr *) ((u8 *)h + l))
466
467         if (ieee80211_is_data(hdr->frame_control) &&
468             is_multicast_ether_addr(hdr->addr1) &&
469             mesh_rmc_check(hdr->addr4, msh_h_get(hdr, hdrlen), rx->dev))
470                 return RX_DROP_MONITOR;
471 #undef msh_h_get
472
473         return RX_CONTINUE;
474 }
475
476
477 static ieee80211_rx_result debug_noinline
478 ieee80211_rx_h_check(struct ieee80211_rx_data *rx)
479 {
480         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
481
482         /* Drop duplicate 802.11 retransmissions (IEEE 802.11 Chap. 9.2.9) */
483         if (rx->sta && !is_multicast_ether_addr(hdr->addr1)) {
484                 if (unlikely(ieee80211_has_retry(hdr->frame_control) &&
485                              rx->sta->last_seq_ctrl[rx->queue] ==
486                              hdr->seq_ctrl)) {
487                         if (rx->flags & IEEE80211_RX_RA_MATCH) {
488                                 rx->local->dot11FrameDuplicateCount++;
489                                 rx->sta->num_duplicates++;
490                         }
491                         return RX_DROP_MONITOR;
492                 } else
493                         rx->sta->last_seq_ctrl[rx->queue] = hdr->seq_ctrl;
494         }
495
496         if (unlikely(rx->skb->len < 16)) {
497                 I802_DEBUG_INC(rx->local->rx_handlers_drop_short);
498                 return RX_DROP_MONITOR;
499         }
500
501         /* Drop disallowed frame classes based on STA auth/assoc state;
502          * IEEE 802.11, Chap 5.5.
503          *
504          * 80211.o does filtering only based on association state, i.e., it
505          * drops Class 3 frames from not associated stations. hostapd sends
506          * deauth/disassoc frames when needed. In addition, hostapd is
507          * responsible for filtering on both auth and assoc states.
508          */
509
510         if (ieee80211_vif_is_mesh(&rx->sdata->vif))
511                 return ieee80211_rx_mesh_check(rx);
512
513         if (unlikely((ieee80211_is_data(hdr->frame_control) ||
514                       ieee80211_is_pspoll(hdr->frame_control)) &&
515                      rx->sdata->vif.type != IEEE80211_IF_TYPE_IBSS &&
516                      (!rx->sta || !test_sta_flags(rx->sta, WLAN_STA_ASSOC)))) {
517                 if ((!ieee80211_has_fromds(hdr->frame_control) &&
518                      !ieee80211_has_tods(hdr->frame_control) &&
519                      ieee80211_is_data(hdr->frame_control)) ||
520                     !(rx->flags & IEEE80211_RX_RA_MATCH)) {
521                         /* Drop IBSS frames and frames for other hosts
522                          * silently. */
523                         return RX_DROP_MONITOR;
524                 }
525
526                 return RX_DROP_MONITOR;
527         }
528
529         return RX_CONTINUE;
530 }
531
532
533 static ieee80211_rx_result debug_noinline
534 ieee80211_rx_h_decrypt(struct ieee80211_rx_data *rx)
535 {
536         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
537         int keyidx;
538         int hdrlen;
539         ieee80211_rx_result result = RX_DROP_UNUSABLE;
540         struct ieee80211_key *stakey = NULL;
541
542         /*
543          * Key selection 101
544          *
545          * There are three types of keys:
546          *  - GTK (group keys)
547          *  - PTK (pairwise keys)
548          *  - STK (station-to-station pairwise keys)
549          *
550          * When selecting a key, we have to distinguish between multicast
551          * (including broadcast) and unicast frames, the latter can only
552          * use PTKs and STKs while the former always use GTKs. Unless, of
553          * course, actual WEP keys ("pre-RSNA") are used, then unicast
554          * frames can also use key indizes like GTKs. Hence, if we don't
555          * have a PTK/STK we check the key index for a WEP key.
556          *
557          * Note that in a regular BSS, multicast frames are sent by the
558          * AP only, associated stations unicast the frame to the AP first
559          * which then multicasts it on their behalf.
560          *
561          * There is also a slight problem in IBSS mode: GTKs are negotiated
562          * with each station, that is something we don't currently handle.
563          * The spec seems to expect that one negotiates the same key with
564          * every station but there's no such requirement; VLANs could be
565          * possible.
566          */
567
568         if (!ieee80211_has_protected(hdr->frame_control))
569                 return RX_CONTINUE;
570
571         /*
572          * No point in finding a key and decrypting if the frame is neither
573          * addressed to us nor a multicast frame.
574          */
575         if (!(rx->flags & IEEE80211_RX_RA_MATCH))
576                 return RX_CONTINUE;
577
578         if (rx->sta)
579                 stakey = rcu_dereference(rx->sta->key);
580
581         if (!is_multicast_ether_addr(hdr->addr1) && stakey) {
582                 rx->key = stakey;
583         } else {
584                 /*
585                  * The device doesn't give us the IV so we won't be
586                  * able to look up the key. That's ok though, we
587                  * don't need to decrypt the frame, we just won't
588                  * be able to keep statistics accurate.
589                  * Except for key threshold notifications, should
590                  * we somehow allow the driver to tell us which key
591                  * the hardware used if this flag is set?
592                  */
593                 if ((rx->status->flag & RX_FLAG_DECRYPTED) &&
594                     (rx->status->flag & RX_FLAG_IV_STRIPPED))
595                         return RX_CONTINUE;
596
597                 hdrlen = ieee80211_hdrlen(hdr->frame_control);
598
599                 if (rx->skb->len < 8 + hdrlen)
600                         return RX_DROP_UNUSABLE; /* TODO: count this? */
601
602                 /*
603                  * no need to call ieee80211_wep_get_keyidx,
604                  * it verifies a bunch of things we've done already
605                  */
606                 keyidx = rx->skb->data[hdrlen + 3] >> 6;
607
608                 rx->key = rcu_dereference(rx->sdata->keys[keyidx]);
609
610                 /*
611                  * RSNA-protected unicast frames should always be sent with
612                  * pairwise or station-to-station keys, but for WEP we allow
613                  * using a key index as well.
614                  */
615                 if (rx->key && rx->key->conf.alg != ALG_WEP &&
616                     !is_multicast_ether_addr(hdr->addr1))
617                         rx->key = NULL;
618         }
619
620         if (rx->key) {
621                 rx->key->tx_rx_count++;
622                 /* TODO: add threshold stuff again */
623         } else {
624                 return RX_DROP_MONITOR;
625         }
626
627         /* Check for weak IVs if possible */
628         if (rx->sta && rx->key->conf.alg == ALG_WEP &&
629             ieee80211_is_data(hdr->frame_control) &&
630             (!(rx->status->flag & RX_FLAG_IV_STRIPPED) ||
631              !(rx->status->flag & RX_FLAG_DECRYPTED)) &&
632             ieee80211_wep_is_weak_iv(rx->skb, rx->key))
633                 rx->sta->wep_weak_iv_count++;
634
635         switch (rx->key->conf.alg) {
636         case ALG_WEP:
637                 result = ieee80211_crypto_wep_decrypt(rx);
638                 break;
639         case ALG_TKIP:
640                 result = ieee80211_crypto_tkip_decrypt(rx);
641                 break;
642         case ALG_CCMP:
643                 result = ieee80211_crypto_ccmp_decrypt(rx);
644                 break;
645         }
646
647         /* either the frame has been decrypted or will be dropped */
648         rx->status->flag |= RX_FLAG_DECRYPTED;
649
650         return result;
651 }
652
653 static void ap_sta_ps_start(struct net_device *dev, struct sta_info *sta)
654 {
655         struct ieee80211_sub_if_data *sdata;
656         DECLARE_MAC_BUF(mac);
657
658         sdata = sta->sdata;
659
660         atomic_inc(&sdata->bss->num_sta_ps);
661         set_and_clear_sta_flags(sta, WLAN_STA_PS, WLAN_STA_PSPOLL);
662 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
663         printk(KERN_DEBUG "%s: STA %s aid %d enters power save mode\n",
664                dev->name, print_mac(mac, sta->addr), sta->aid);
665 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
666 }
667
668 static int ap_sta_ps_end(struct net_device *dev, struct sta_info *sta)
669 {
670         struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
671         struct sk_buff *skb;
672         int sent = 0;
673         struct ieee80211_sub_if_data *sdata;
674         struct ieee80211_tx_info *info;
675         DECLARE_MAC_BUF(mac);
676
677         sdata = sta->sdata;
678
679         atomic_dec(&sdata->bss->num_sta_ps);
680
681         clear_sta_flags(sta, WLAN_STA_PS | WLAN_STA_PSPOLL);
682
683         if (!skb_queue_empty(&sta->ps_tx_buf))
684                 sta_info_clear_tim_bit(sta);
685
686 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
687         printk(KERN_DEBUG "%s: STA %s aid %d exits power save mode\n",
688                dev->name, print_mac(mac, sta->addr), sta->aid);
689 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
690
691         /* Send all buffered frames to the station */
692         while ((skb = skb_dequeue(&sta->tx_filtered)) != NULL) {
693                 info = IEEE80211_SKB_CB(skb);
694                 sent++;
695                 info->flags |= IEEE80211_TX_CTL_REQUEUE;
696                 dev_queue_xmit(skb);
697         }
698         while ((skb = skb_dequeue(&sta->ps_tx_buf)) != NULL) {
699                 info = IEEE80211_SKB_CB(skb);
700                 local->total_ps_buffered--;
701                 sent++;
702 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
703                 printk(KERN_DEBUG "%s: STA %s aid %d send PS frame "
704                        "since STA not sleeping anymore\n", dev->name,
705                        print_mac(mac, sta->addr), sta->aid);
706 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
707                 info->flags |= IEEE80211_TX_CTL_REQUEUE;
708                 dev_queue_xmit(skb);
709         }
710
711         return sent;
712 }
713
714 static ieee80211_rx_result debug_noinline
715 ieee80211_rx_h_sta_process(struct ieee80211_rx_data *rx)
716 {
717         struct sta_info *sta = rx->sta;
718         struct net_device *dev = rx->dev;
719         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
720
721         if (!sta)
722                 return RX_CONTINUE;
723
724         /* Update last_rx only for IBSS packets which are for the current
725          * BSSID to avoid keeping the current IBSS network alive in cases where
726          * other STAs are using different BSSID. */
727         if (rx->sdata->vif.type == IEEE80211_IF_TYPE_IBSS) {
728                 u8 *bssid = ieee80211_get_bssid(hdr, rx->skb->len,
729                                                 IEEE80211_IF_TYPE_IBSS);
730                 if (compare_ether_addr(bssid, rx->sdata->u.sta.bssid) == 0)
731                         sta->last_rx = jiffies;
732         } else
733         if (!is_multicast_ether_addr(hdr->addr1) ||
734             rx->sdata->vif.type == IEEE80211_IF_TYPE_STA) {
735                 /* Update last_rx only for unicast frames in order to prevent
736                  * the Probe Request frames (the only broadcast frames from a
737                  * STA in infrastructure mode) from keeping a connection alive.
738                  * Mesh beacons will update last_rx when if they are found to
739                  * match the current local configuration when processed.
740                  */
741                 sta->last_rx = jiffies;
742         }
743
744         if (!(rx->flags & IEEE80211_RX_RA_MATCH))
745                 return RX_CONTINUE;
746
747         sta->rx_fragments++;
748         sta->rx_bytes += rx->skb->len;
749         sta->last_signal = rx->status->signal;
750         sta->last_qual = rx->status->qual;
751         sta->last_noise = rx->status->noise;
752
753         if (!ieee80211_has_morefrags(hdr->frame_control) &&
754             (rx->sdata->vif.type == IEEE80211_IF_TYPE_AP ||
755              rx->sdata->vif.type == IEEE80211_IF_TYPE_VLAN)) {
756                 /* Change STA power saving mode only in the end of a frame
757                  * exchange sequence */
758                 if (test_sta_flags(sta, WLAN_STA_PS) &&
759                     !ieee80211_has_pm(hdr->frame_control))
760                         rx->sent_ps_buffered += ap_sta_ps_end(dev, sta);
761                 else if (!test_sta_flags(sta, WLAN_STA_PS) &&
762                          ieee80211_has_pm(hdr->frame_control))
763                         ap_sta_ps_start(dev, sta);
764         }
765
766         /* Drop data::nullfunc frames silently, since they are used only to
767          * control station power saving mode. */
768         if (ieee80211_is_nullfunc(hdr->frame_control)) {
769                 I802_DEBUG_INC(rx->local->rx_handlers_drop_nullfunc);
770                 /* Update counter and free packet here to avoid counting this
771                  * as a dropped packed. */
772                 sta->rx_packets++;
773                 dev_kfree_skb(rx->skb);
774                 return RX_QUEUED;
775         }
776
777         return RX_CONTINUE;
778 } /* ieee80211_rx_h_sta_process */
779
780 static inline struct ieee80211_fragment_entry *
781 ieee80211_reassemble_add(struct ieee80211_sub_if_data *sdata,
782                          unsigned int frag, unsigned int seq, int rx_queue,
783                          struct sk_buff **skb)
784 {
785         struct ieee80211_fragment_entry *entry;
786         int idx;
787
788         idx = sdata->fragment_next;
789         entry = &sdata->fragments[sdata->fragment_next++];
790         if (sdata->fragment_next >= IEEE80211_FRAGMENT_MAX)
791                 sdata->fragment_next = 0;
792
793         if (!skb_queue_empty(&entry->skb_list)) {
794 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG
795                 struct ieee80211_hdr *hdr =
796                         (struct ieee80211_hdr *) entry->skb_list.next->data;
797                 DECLARE_MAC_BUF(mac);
798                 DECLARE_MAC_BUF(mac2);
799                 printk(KERN_DEBUG "%s: RX reassembly removed oldest "
800                        "fragment entry (idx=%d age=%lu seq=%d last_frag=%d "
801                        "addr1=%s addr2=%s\n",
802                        sdata->dev->name, idx,
803                        jiffies - entry->first_frag_time, entry->seq,
804                        entry->last_frag, print_mac(mac, hdr->addr1),
805                        print_mac(mac2, hdr->addr2));
806 #endif
807                 __skb_queue_purge(&entry->skb_list);
808         }
809
810         __skb_queue_tail(&entry->skb_list, *skb); /* no need for locking */
811         *skb = NULL;
812         entry->first_frag_time = jiffies;
813         entry->seq = seq;
814         entry->rx_queue = rx_queue;
815         entry->last_frag = frag;
816         entry->ccmp = 0;
817         entry->extra_len = 0;
818
819         return entry;
820 }
821
822 static inline struct ieee80211_fragment_entry *
823 ieee80211_reassemble_find(struct ieee80211_sub_if_data *sdata,
824                           unsigned int frag, unsigned int seq,
825                           int rx_queue, struct ieee80211_hdr *hdr)
826 {
827         struct ieee80211_fragment_entry *entry;
828         int i, idx;
829
830         idx = sdata->fragment_next;
831         for (i = 0; i < IEEE80211_FRAGMENT_MAX; i++) {
832                 struct ieee80211_hdr *f_hdr;
833
834                 idx--;
835                 if (idx < 0)
836                         idx = IEEE80211_FRAGMENT_MAX - 1;
837
838                 entry = &sdata->fragments[idx];
839                 if (skb_queue_empty(&entry->skb_list) || entry->seq != seq ||
840                     entry->rx_queue != rx_queue ||
841                     entry->last_frag + 1 != frag)
842                         continue;
843
844                 f_hdr = (struct ieee80211_hdr *)entry->skb_list.next->data;
845
846                 /*
847                  * Check ftype and addresses are equal, else check next fragment
848                  */
849                 if (((hdr->frame_control ^ f_hdr->frame_control) &
850                      cpu_to_le16(IEEE80211_FCTL_FTYPE)) ||
851                     compare_ether_addr(hdr->addr1, f_hdr->addr1) != 0 ||
852                     compare_ether_addr(hdr->addr2, f_hdr->addr2) != 0)
853                         continue;
854
855                 if (time_after(jiffies, entry->first_frag_time + 2 * HZ)) {
856                         __skb_queue_purge(&entry->skb_list);
857                         continue;
858                 }
859                 return entry;
860         }
861
862         return NULL;
863 }
864
865 static ieee80211_rx_result debug_noinline
866 ieee80211_rx_h_defragment(struct ieee80211_rx_data *rx)
867 {
868         struct ieee80211_hdr *hdr;
869         u16 sc;
870         __le16 fc;
871         unsigned int frag, seq;
872         struct ieee80211_fragment_entry *entry;
873         struct sk_buff *skb;
874         DECLARE_MAC_BUF(mac);
875
876         hdr = (struct ieee80211_hdr *)rx->skb->data;
877         fc = hdr->frame_control;
878         sc = le16_to_cpu(hdr->seq_ctrl);
879         frag = sc & IEEE80211_SCTL_FRAG;
880
881         if (likely((!ieee80211_has_morefrags(fc) && frag == 0) ||
882                    (rx->skb)->len < 24 ||
883                    is_multicast_ether_addr(hdr->addr1))) {
884                 /* not fragmented */
885                 goto out;
886         }
887         I802_DEBUG_INC(rx->local->rx_handlers_fragments);
888
889         seq = (sc & IEEE80211_SCTL_SEQ) >> 4;
890
891         if (frag == 0) {
892                 /* This is the first fragment of a new frame. */
893                 entry = ieee80211_reassemble_add(rx->sdata, frag, seq,
894                                                  rx->queue, &(rx->skb));
895                 if (rx->key && rx->key->conf.alg == ALG_CCMP &&
896                     ieee80211_has_protected(fc)) {
897                         /* Store CCMP PN so that we can verify that the next
898                          * fragment has a sequential PN value. */
899                         entry->ccmp = 1;
900                         memcpy(entry->last_pn,
901                                rx->key->u.ccmp.rx_pn[rx->queue],
902                                CCMP_PN_LEN);
903                 }
904                 return RX_QUEUED;
905         }
906
907         /* This is a fragment for a frame that should already be pending in
908          * fragment cache. Add this fragment to the end of the pending entry.
909          */
910         entry = ieee80211_reassemble_find(rx->sdata, frag, seq, rx->queue, hdr);
911         if (!entry) {
912                 I802_DEBUG_INC(rx->local->rx_handlers_drop_defrag);
913                 return RX_DROP_MONITOR;
914         }
915
916         /* Verify that MPDUs within one MSDU have sequential PN values.
917          * (IEEE 802.11i, 8.3.3.4.5) */
918         if (entry->ccmp) {
919                 int i;
920                 u8 pn[CCMP_PN_LEN], *rpn;
921                 if (!rx->key || rx->key->conf.alg != ALG_CCMP)
922                         return RX_DROP_UNUSABLE;
923                 memcpy(pn, entry->last_pn, CCMP_PN_LEN);
924                 for (i = CCMP_PN_LEN - 1; i >= 0; i--) {
925                         pn[i]++;
926                         if (pn[i])
927                                 break;
928                 }
929                 rpn = rx->key->u.ccmp.rx_pn[rx->queue];
930                 if (memcmp(pn, rpn, CCMP_PN_LEN))
931                         return RX_DROP_UNUSABLE;
932                 memcpy(entry->last_pn, pn, CCMP_PN_LEN);
933         }
934
935         skb_pull(rx->skb, ieee80211_hdrlen(fc));
936         __skb_queue_tail(&entry->skb_list, rx->skb);
937         entry->last_frag = frag;
938         entry->extra_len += rx->skb->len;
939         if (ieee80211_has_morefrags(fc)) {
940                 rx->skb = NULL;
941                 return RX_QUEUED;
942         }
943
944         rx->skb = __skb_dequeue(&entry->skb_list);
945         if (skb_tailroom(rx->skb) < entry->extra_len) {
946                 I802_DEBUG_INC(rx->local->rx_expand_skb_head2);
947                 if (unlikely(pskb_expand_head(rx->skb, 0, entry->extra_len,
948                                               GFP_ATOMIC))) {
949                         I802_DEBUG_INC(rx->local->rx_handlers_drop_defrag);
950                         __skb_queue_purge(&entry->skb_list);
951                         return RX_DROP_UNUSABLE;
952                 }
953         }
954         while ((skb = __skb_dequeue(&entry->skb_list))) {
955                 memcpy(skb_put(rx->skb, skb->len), skb->data, skb->len);
956                 dev_kfree_skb(skb);
957         }
958
959         /* Complete frame has been reassembled - process it now */
960         rx->flags |= IEEE80211_RX_FRAGMENTED;
961
962  out:
963         if (rx->sta)
964                 rx->sta->rx_packets++;
965         if (is_multicast_ether_addr(hdr->addr1))
966                 rx->local->dot11MulticastReceivedFrameCount++;
967         else
968                 ieee80211_led_rx(rx->local);
969         return RX_CONTINUE;
970 }
971
972 static ieee80211_rx_result debug_noinline
973 ieee80211_rx_h_ps_poll(struct ieee80211_rx_data *rx)
974 {
975         struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(rx->dev);
976         struct sk_buff *skb;
977         int no_pending_pkts;
978         DECLARE_MAC_BUF(mac);
979         __le16 fc = ((struct ieee80211_hdr *)rx->skb->data)->frame_control;
980
981         if (likely(!rx->sta || !ieee80211_is_pspoll(fc) ||
982                    !(rx->flags & IEEE80211_RX_RA_MATCH)))
983                 return RX_CONTINUE;
984
985         if ((sdata->vif.type != IEEE80211_IF_TYPE_AP) &&
986             (sdata->vif.type != IEEE80211_IF_TYPE_VLAN))
987                 return RX_DROP_UNUSABLE;
988
989         skb = skb_dequeue(&rx->sta->tx_filtered);
990         if (!skb) {
991                 skb = skb_dequeue(&rx->sta->ps_tx_buf);
992                 if (skb)
993                         rx->local->total_ps_buffered--;
994         }
995         no_pending_pkts = skb_queue_empty(&rx->sta->tx_filtered) &&
996                 skb_queue_empty(&rx->sta->ps_tx_buf);
997
998         if (skb) {
999                 struct ieee80211_hdr *hdr =
1000                         (struct ieee80211_hdr *) skb->data;
1001
1002                 /*
1003                  * Tell TX path to send one frame even though the STA may
1004                  * still remain is PS mode after this frame exchange.
1005                  */
1006                 set_sta_flags(rx->sta, WLAN_STA_PSPOLL);
1007
1008 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
1009                 printk(KERN_DEBUG "STA %s aid %d: PS Poll (entries after %d)\n",
1010                        print_mac(mac, rx->sta->addr), rx->sta->aid,
1011                        skb_queue_len(&rx->sta->ps_tx_buf));
1012 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
1013
1014                 /* Use MoreData flag to indicate whether there are more
1015                  * buffered frames for this STA */
1016                 if (no_pending_pkts)
1017                         hdr->frame_control &= cpu_to_le16(~IEEE80211_FCTL_MOREDATA);
1018                 else
1019                         hdr->frame_control |= cpu_to_le16(IEEE80211_FCTL_MOREDATA);
1020
1021                 dev_queue_xmit(skb);
1022
1023                 if (no_pending_pkts)
1024                         sta_info_clear_tim_bit(rx->sta);
1025 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
1026         } else if (!rx->sent_ps_buffered) {
1027                 /*
1028                  * FIXME: This can be the result of a race condition between
1029                  *        us expiring a frame and the station polling for it.
1030                  *        Should we send it a null-func frame indicating we
1031                  *        have nothing buffered for it?
1032                  */
1033                 printk(KERN_DEBUG "%s: STA %s sent PS Poll even "
1034                        "though there are no buffered frames for it\n",
1035                        rx->dev->name, print_mac(mac, rx->sta->addr));
1036 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
1037         }
1038
1039         /* Free PS Poll skb here instead of returning RX_DROP that would
1040          * count as an dropped frame. */
1041         dev_kfree_skb(rx->skb);
1042
1043         return RX_QUEUED;
1044 }
1045
1046 static ieee80211_rx_result debug_noinline
1047 ieee80211_rx_h_remove_qos_control(struct ieee80211_rx_data *rx)
1048 {
1049         u8 *data = rx->skb->data;
1050         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)data;
1051
1052         if (!ieee80211_is_data_qos(hdr->frame_control))
1053                 return RX_CONTINUE;
1054
1055         /* remove the qos control field, update frame type and meta-data */
1056         memmove(data + IEEE80211_QOS_CTL_LEN, data,
1057                 ieee80211_hdrlen(hdr->frame_control) - IEEE80211_QOS_CTL_LEN);
1058         hdr = (struct ieee80211_hdr *)skb_pull(rx->skb, IEEE80211_QOS_CTL_LEN);
1059         /* change frame type to non QOS */
1060         hdr->frame_control &= ~cpu_to_le16(IEEE80211_STYPE_QOS_DATA);
1061
1062         return RX_CONTINUE;
1063 }
1064
1065 static int
1066 ieee80211_802_1x_port_control(struct ieee80211_rx_data *rx)
1067 {
1068         if (unlikely(!rx->sta ||
1069             !test_sta_flags(rx->sta, WLAN_STA_AUTHORIZED)))
1070                 return -EACCES;
1071
1072         return 0;
1073 }
1074
1075 static int
1076 ieee80211_drop_unencrypted(struct ieee80211_rx_data *rx, __le16 fc)
1077 {
1078         /*
1079          * Pass through unencrypted frames if the hardware has
1080          * decrypted them already.
1081          */
1082         if (rx->status->flag & RX_FLAG_DECRYPTED)
1083                 return 0;
1084
1085         /* Drop unencrypted frames if key is set. */
1086         if (unlikely(!ieee80211_has_protected(fc) &&
1087                      !ieee80211_is_nullfunc(fc) &&
1088                      (rx->key || rx->sdata->drop_unencrypted)))
1089                 return -EACCES;
1090
1091         return 0;
1092 }
1093
1094 static int
1095 ieee80211_data_to_8023(struct ieee80211_rx_data *rx)
1096 {
1097         struct net_device *dev = rx->dev;
1098         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) rx->skb->data;
1099         u16 hdrlen, ethertype;
1100         u8 *payload;
1101         u8 dst[ETH_ALEN];
1102         u8 src[ETH_ALEN] __aligned(2);
1103         struct sk_buff *skb = rx->skb;
1104         struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
1105         DECLARE_MAC_BUF(mac);
1106         DECLARE_MAC_BUF(mac2);
1107         DECLARE_MAC_BUF(mac3);
1108         DECLARE_MAC_BUF(mac4);
1109
1110         if (unlikely(!ieee80211_is_data_present(hdr->frame_control)))
1111                 return -1;
1112
1113         hdrlen = ieee80211_hdrlen(hdr->frame_control);
1114
1115         if (ieee80211_vif_is_mesh(&sdata->vif))
1116                 hdrlen += ieee80211_get_mesh_hdrlen(
1117                                 (struct ieee80211s_hdr *) (skb->data + hdrlen));
1118
1119         /* convert IEEE 802.11 header + possible LLC headers into Ethernet
1120          * header
1121          * IEEE 802.11 address fields:
1122          * ToDS FromDS Addr1 Addr2 Addr3 Addr4
1123          *   0     0   DA    SA    BSSID n/a
1124          *   0     1   DA    BSSID SA    n/a
1125          *   1     0   BSSID SA    DA    n/a
1126          *   1     1   RA    TA    DA    SA
1127          */
1128         memcpy(dst, ieee80211_get_DA(hdr), ETH_ALEN);
1129         memcpy(src, ieee80211_get_SA(hdr), ETH_ALEN);
1130
1131         switch (hdr->frame_control &
1132                 cpu_to_le16(IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS)) {
1133         case __constant_cpu_to_le16(IEEE80211_FCTL_TODS):
1134                 if (unlikely(sdata->vif.type != IEEE80211_IF_TYPE_AP &&
1135                              sdata->vif.type != IEEE80211_IF_TYPE_VLAN))
1136                         return -1;
1137                 break;
1138         case __constant_cpu_to_le16(IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS):
1139                 if (unlikely(sdata->vif.type != IEEE80211_IF_TYPE_WDS &&
1140                              sdata->vif.type != IEEE80211_IF_TYPE_MESH_POINT))
1141                         return -1;
1142                 break;
1143         case __constant_cpu_to_le16(IEEE80211_FCTL_FROMDS):
1144                 if (sdata->vif.type != IEEE80211_IF_TYPE_STA ||
1145                     (is_multicast_ether_addr(dst) &&
1146                      !compare_ether_addr(src, dev->dev_addr)))
1147                         return -1;
1148                 break;
1149         case __constant_cpu_to_le16(0):
1150                 if (sdata->vif.type != IEEE80211_IF_TYPE_IBSS)
1151                         return -1;
1152                 break;
1153         }
1154
1155         if (unlikely(skb->len - hdrlen < 8))
1156                 return -1;
1157
1158         payload = skb->data + hdrlen;
1159         ethertype = (payload[6] << 8) | payload[7];
1160
1161         if (likely((compare_ether_addr(payload, rfc1042_header) == 0 &&
1162                     ethertype != ETH_P_AARP && ethertype != ETH_P_IPX) ||
1163                    compare_ether_addr(payload, bridge_tunnel_header) == 0)) {
1164                 /* remove RFC1042 or Bridge-Tunnel encapsulation and
1165                  * replace EtherType */
1166                 skb_pull(skb, hdrlen + 6);
1167                 memcpy(skb_push(skb, ETH_ALEN), src, ETH_ALEN);
1168                 memcpy(skb_push(skb, ETH_ALEN), dst, ETH_ALEN);
1169         } else {
1170                 struct ethhdr *ehdr;
1171                 __be16 len;
1172
1173                 skb_pull(skb, hdrlen);
1174                 len = htons(skb->len);
1175                 ehdr = (struct ethhdr *) skb_push(skb, sizeof(struct ethhdr));
1176                 memcpy(ehdr->h_dest, dst, ETH_ALEN);
1177                 memcpy(ehdr->h_source, src, ETH_ALEN);
1178                 ehdr->h_proto = len;
1179         }
1180         return 0;
1181 }
1182
1183 /*
1184  * requires that rx->skb is a frame with ethernet header
1185  */
1186 static bool ieee80211_frame_allowed(struct ieee80211_rx_data *rx, __le16 fc)
1187 {
1188         static const u8 pae_group_addr[ETH_ALEN] __aligned(2)
1189                 = { 0x01, 0x80, 0xC2, 0x00, 0x00, 0x03 };
1190         struct ethhdr *ehdr = (struct ethhdr *) rx->skb->data;
1191
1192         /*
1193          * Allow EAPOL frames to us/the PAE group address regardless
1194          * of whether the frame was encrypted or not.
1195          */
1196         if (ehdr->h_proto == htons(ETH_P_PAE) &&
1197             (compare_ether_addr(ehdr->h_dest, rx->dev->dev_addr) == 0 ||
1198              compare_ether_addr(ehdr->h_dest, pae_group_addr) == 0))
1199                 return true;
1200
1201         if (ieee80211_802_1x_port_control(rx) ||
1202             ieee80211_drop_unencrypted(rx, fc))
1203                 return false;
1204
1205         return true;
1206 }
1207
1208 /*
1209  * requires that rx->skb is a frame with ethernet header
1210  */
1211 static void
1212 ieee80211_deliver_skb(struct ieee80211_rx_data *rx)
1213 {
1214         struct net_device *dev = rx->dev;
1215         struct ieee80211_local *local = rx->local;
1216         struct sk_buff *skb, *xmit_skb;
1217         struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
1218         struct ethhdr *ehdr = (struct ethhdr *) rx->skb->data;
1219         struct sta_info *dsta;
1220
1221         skb = rx->skb;
1222         xmit_skb = NULL;
1223
1224         if (local->bridge_packets && (sdata->vif.type == IEEE80211_IF_TYPE_AP ||
1225                                       sdata->vif.type == IEEE80211_IF_TYPE_VLAN) &&
1226             (rx->flags & IEEE80211_RX_RA_MATCH)) {
1227                 if (is_multicast_ether_addr(ehdr->h_dest)) {
1228                         /*
1229                          * send multicast frames both to higher layers in
1230                          * local net stack and back to the wireless medium
1231                          */
1232                         xmit_skb = skb_copy(skb, GFP_ATOMIC);
1233                         if (!xmit_skb && net_ratelimit())
1234                                 printk(KERN_DEBUG "%s: failed to clone "
1235                                        "multicast frame\n", dev->name);
1236                 } else {
1237                         dsta = sta_info_get(local, skb->data);
1238                         if (dsta && dsta->sdata->dev == dev) {
1239                                 /*
1240                                  * The destination station is associated to
1241                                  * this AP (in this VLAN), so send the frame
1242                                  * directly to it and do not pass it to local
1243                                  * net stack.
1244                                  */
1245                                 xmit_skb = skb;
1246                                 skb = NULL;
1247                         }
1248                 }
1249         }
1250
1251         if (skb) {
1252                 /* deliver to local stack */
1253                 skb->protocol = eth_type_trans(skb, dev);
1254                 memset(skb->cb, 0, sizeof(skb->cb));
1255                 netif_rx(skb);
1256         }
1257
1258         if (xmit_skb) {
1259                 /* send to wireless media */
1260                 xmit_skb->protocol = htons(ETH_P_802_3);
1261                 skb_reset_network_header(xmit_skb);
1262                 skb_reset_mac_header(xmit_skb);
1263                 dev_queue_xmit(xmit_skb);
1264         }
1265 }
1266
1267 static ieee80211_rx_result debug_noinline
1268 ieee80211_rx_h_amsdu(struct ieee80211_rx_data *rx)
1269 {
1270         struct net_device *dev = rx->dev;
1271         struct ieee80211_local *local = rx->local;
1272         u16 ethertype;
1273         u8 *payload;
1274         struct sk_buff *skb = rx->skb, *frame = NULL;
1275         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
1276         __le16 fc = hdr->frame_control;
1277         const struct ethhdr *eth;
1278         int remaining, err;
1279         u8 dst[ETH_ALEN];
1280         u8 src[ETH_ALEN];
1281         DECLARE_MAC_BUF(mac);
1282
1283         if (unlikely(!ieee80211_is_data(fc)))
1284                 return RX_CONTINUE;
1285
1286         if (unlikely(!ieee80211_is_data_present(fc)))
1287                 return RX_DROP_MONITOR;
1288
1289         if (!(rx->flags & IEEE80211_RX_AMSDU))
1290                 return RX_CONTINUE;
1291
1292         err = ieee80211_data_to_8023(rx);
1293         if (unlikely(err))
1294                 return RX_DROP_UNUSABLE;
1295
1296         skb->dev = dev;
1297
1298         dev->stats.rx_packets++;
1299         dev->stats.rx_bytes += skb->len;
1300
1301         /* skip the wrapping header */
1302         eth = (struct ethhdr *) skb_pull(skb, sizeof(struct ethhdr));
1303         if (!eth)
1304                 return RX_DROP_UNUSABLE;
1305
1306         while (skb != frame) {
1307                 u8 padding;
1308                 __be16 len = eth->h_proto;
1309                 unsigned int subframe_len = sizeof(struct ethhdr) + ntohs(len);
1310
1311                 remaining = skb->len;
1312                 memcpy(dst, eth->h_dest, ETH_ALEN);
1313                 memcpy(src, eth->h_source, ETH_ALEN);
1314
1315                 padding = ((4 - subframe_len) & 0x3);
1316                 /* the last MSDU has no padding */
1317                 if (subframe_len > remaining)
1318                         return RX_DROP_UNUSABLE;
1319
1320                 skb_pull(skb, sizeof(struct ethhdr));
1321                 /* if last subframe reuse skb */
1322                 if (remaining <= subframe_len + padding)
1323                         frame = skb;
1324                 else {
1325                         frame = dev_alloc_skb(local->hw.extra_tx_headroom +
1326                                               subframe_len);
1327
1328                         if (frame == NULL)
1329                                 return RX_DROP_UNUSABLE;
1330
1331                         skb_reserve(frame, local->hw.extra_tx_headroom +
1332                                     sizeof(struct ethhdr));
1333                         memcpy(skb_put(frame, ntohs(len)), skb->data,
1334                                 ntohs(len));
1335
1336                         eth = (struct ethhdr *) skb_pull(skb, ntohs(len) +
1337                                                         padding);
1338                         if (!eth) {
1339                                 dev_kfree_skb(frame);
1340                                 return RX_DROP_UNUSABLE;
1341                         }
1342                 }
1343
1344                 skb_reset_network_header(frame);
1345                 frame->dev = dev;
1346                 frame->priority = skb->priority;
1347                 rx->skb = frame;
1348
1349                 payload = frame->data;
1350                 ethertype = (payload[6] << 8) | payload[7];
1351
1352                 if (likely((compare_ether_addr(payload, rfc1042_header) == 0 &&
1353                             ethertype != ETH_P_AARP && ethertype != ETH_P_IPX) ||
1354                            compare_ether_addr(payload,
1355                                               bridge_tunnel_header) == 0)) {
1356                         /* remove RFC1042 or Bridge-Tunnel
1357                          * encapsulation and replace EtherType */
1358                         skb_pull(frame, 6);
1359                         memcpy(skb_push(frame, ETH_ALEN), src, ETH_ALEN);
1360                         memcpy(skb_push(frame, ETH_ALEN), dst, ETH_ALEN);
1361                 } else {
1362                         memcpy(skb_push(frame, sizeof(__be16)),
1363                                &len, sizeof(__be16));
1364                         memcpy(skb_push(frame, ETH_ALEN), src, ETH_ALEN);
1365                         memcpy(skb_push(frame, ETH_ALEN), dst, ETH_ALEN);
1366                 }
1367
1368                 if (!ieee80211_frame_allowed(rx, fc)) {
1369                         if (skb == frame) /* last frame */
1370                                 return RX_DROP_UNUSABLE;
1371                         dev_kfree_skb(frame);
1372                         continue;
1373                 }
1374
1375                 ieee80211_deliver_skb(rx);
1376         }
1377
1378         return RX_QUEUED;
1379 }
1380
1381 static ieee80211_rx_result debug_noinline
1382 ieee80211_rx_h_mesh_fwding(struct ieee80211_rx_data *rx)
1383 {
1384         struct ieee80211_hdr *hdr;
1385         struct ieee80211s_hdr *mesh_hdr;
1386         unsigned int hdrlen;
1387         struct sk_buff *skb = rx->skb, *fwd_skb;
1388
1389         hdr = (struct ieee80211_hdr *) skb->data;
1390         hdrlen = ieee80211_hdrlen(hdr->frame_control);
1391         mesh_hdr = (struct ieee80211s_hdr *) (skb->data + hdrlen);
1392
1393         if (!ieee80211_is_data(hdr->frame_control))
1394                 return RX_CONTINUE;
1395
1396         if (!mesh_hdr->ttl)
1397                 /* illegal frame */
1398                 return RX_DROP_MONITOR;
1399
1400         if (compare_ether_addr(rx->dev->dev_addr, hdr->addr3) == 0)
1401                 return RX_CONTINUE;
1402
1403         mesh_hdr->ttl--;
1404
1405         if (rx->flags & IEEE80211_RX_RA_MATCH) {
1406                 if (!mesh_hdr->ttl)
1407                         IEEE80211_IFSTA_MESH_CTR_INC(&rx->sdata->u.sta,
1408                                                      dropped_frames_ttl);
1409                 else {
1410                         struct ieee80211_hdr *fwd_hdr;
1411                         fwd_skb = skb_copy(skb, GFP_ATOMIC);
1412
1413                         if (!fwd_skb && net_ratelimit())
1414                                 printk(KERN_DEBUG "%s: failed to clone mesh frame\n",
1415                                                    rx->dev->name);
1416
1417                         fwd_hdr =  (struct ieee80211_hdr *) fwd_skb->data;
1418                         /*
1419                          * Save TA to addr1 to send TA a path error if a
1420                          * suitable next hop is not found
1421                          */
1422                         memcpy(fwd_hdr->addr1, fwd_hdr->addr2, ETH_ALEN);
1423                         memcpy(fwd_hdr->addr2, rx->dev->dev_addr, ETH_ALEN);
1424                         fwd_skb->dev = rx->local->mdev;
1425                         fwd_skb->iif = rx->dev->ifindex;
1426                         dev_queue_xmit(fwd_skb);
1427                 }
1428         }
1429
1430         if (is_multicast_ether_addr(hdr->addr3) ||
1431             rx->dev->flags & IFF_PROMISC)
1432                 return RX_CONTINUE;
1433         else
1434                 return RX_DROP_MONITOR;
1435 }
1436
1437
1438 static ieee80211_rx_result debug_noinline
1439 ieee80211_rx_h_data(struct ieee80211_rx_data *rx)
1440 {
1441         struct net_device *dev = rx->dev;
1442         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
1443         __le16 fc = hdr->frame_control;
1444         int err;
1445
1446         if (unlikely(!ieee80211_is_data(hdr->frame_control)))
1447                 return RX_CONTINUE;
1448
1449         if (unlikely(!ieee80211_is_data_present(hdr->frame_control)))
1450                 return RX_DROP_MONITOR;
1451
1452         err = ieee80211_data_to_8023(rx);
1453         if (unlikely(err))
1454                 return RX_DROP_UNUSABLE;
1455
1456         if (!ieee80211_frame_allowed(rx, fc))
1457                 return RX_DROP_MONITOR;
1458
1459         rx->skb->dev = dev;
1460
1461         dev->stats.rx_packets++;
1462         dev->stats.rx_bytes += rx->skb->len;
1463
1464         ieee80211_deliver_skb(rx);
1465
1466         return RX_QUEUED;
1467 }
1468
1469 static ieee80211_rx_result debug_noinline
1470 ieee80211_rx_h_ctrl(struct ieee80211_rx_data *rx)
1471 {
1472         struct ieee80211_local *local = rx->local;
1473         struct ieee80211_hw *hw = &local->hw;
1474         struct sk_buff *skb = rx->skb;
1475         struct ieee80211_bar *bar = (struct ieee80211_bar *)skb->data;
1476         struct tid_ampdu_rx *tid_agg_rx;
1477         u16 start_seq_num;
1478         u16 tid;
1479
1480         if (likely(!ieee80211_is_ctl(bar->frame_control)))
1481                 return RX_CONTINUE;
1482
1483         if (ieee80211_is_back_req(bar->frame_control)) {
1484                 if (!rx->sta)
1485                         return RX_CONTINUE;
1486                 tid = le16_to_cpu(bar->control) >> 12;
1487                 if (rx->sta->ampdu_mlme.tid_state_rx[tid]
1488                                         != HT_AGG_STATE_OPERATIONAL)
1489                         return RX_CONTINUE;
1490                 tid_agg_rx = rx->sta->ampdu_mlme.tid_rx[tid];
1491
1492                 start_seq_num = le16_to_cpu(bar->start_seq_num) >> 4;
1493
1494                 /* reset session timer */
1495                 if (tid_agg_rx->timeout) {
1496                         unsigned long expires =
1497                                 jiffies + (tid_agg_rx->timeout / 1000) * HZ;
1498                         mod_timer(&tid_agg_rx->session_timer, expires);
1499                 }
1500
1501                 /* manage reordering buffer according to requested */
1502                 /* sequence number */
1503                 rcu_read_lock();
1504                 ieee80211_sta_manage_reorder_buf(hw, tid_agg_rx, NULL,
1505                                                  start_seq_num, 1);
1506                 rcu_read_unlock();
1507                 return RX_DROP_UNUSABLE;
1508         }
1509
1510         return RX_CONTINUE;
1511 }
1512
1513 static ieee80211_rx_result debug_noinline
1514 ieee80211_rx_h_mgmt(struct ieee80211_rx_data *rx)
1515 {
1516         struct ieee80211_sub_if_data *sdata;
1517
1518         if (!(rx->flags & IEEE80211_RX_RA_MATCH))
1519                 return RX_DROP_MONITOR;
1520
1521         sdata = IEEE80211_DEV_TO_SUB_IF(rx->dev);
1522         if ((sdata->vif.type == IEEE80211_IF_TYPE_STA ||
1523              sdata->vif.type == IEEE80211_IF_TYPE_IBSS ||
1524              sdata->vif.type == IEEE80211_IF_TYPE_MESH_POINT) &&
1525             !(sdata->flags & IEEE80211_SDATA_USERSPACE_MLME))
1526                 ieee80211_sta_rx_mgmt(rx->dev, rx->skb, rx->status);
1527         else
1528                 return RX_DROP_MONITOR;
1529
1530         return RX_QUEUED;
1531 }
1532
1533 static void ieee80211_rx_michael_mic_report(struct net_device *dev,
1534                                             struct ieee80211_hdr *hdr,
1535                                             struct ieee80211_rx_data *rx)
1536 {
1537         int keyidx;
1538         unsigned int hdrlen;
1539         DECLARE_MAC_BUF(mac);
1540         DECLARE_MAC_BUF(mac2);
1541
1542         hdrlen = ieee80211_hdrlen(hdr->frame_control);
1543         if (rx->skb->len >= hdrlen + 4)
1544                 keyidx = rx->skb->data[hdrlen + 3] >> 6;
1545         else
1546                 keyidx = -1;
1547
1548         if (!rx->sta) {
1549                 /*
1550                  * Some hardware seem to generate incorrect Michael MIC
1551                  * reports; ignore them to avoid triggering countermeasures.
1552                  */
1553                 goto ignore;
1554         }
1555
1556         if (!ieee80211_has_protected(hdr->frame_control))
1557                 goto ignore;
1558
1559         if (rx->sdata->vif.type == IEEE80211_IF_TYPE_AP && keyidx) {
1560                 /*
1561                  * APs with pairwise keys should never receive Michael MIC
1562                  * errors for non-zero keyidx because these are reserved for
1563                  * group keys and only the AP is sending real multicast
1564                  * frames in the BSS.
1565                  */
1566                 goto ignore;
1567         }
1568
1569         if (!ieee80211_is_data(hdr->frame_control) &&
1570             !ieee80211_is_auth(hdr->frame_control))
1571                 goto ignore;
1572
1573         mac80211_ev_michael_mic_failure(rx->dev, keyidx, hdr);
1574  ignore:
1575         dev_kfree_skb(rx->skb);
1576         rx->skb = NULL;
1577 }
1578
1579 /* TODO: use IEEE80211_RX_FRAGMENTED */
1580 static void ieee80211_rx_cooked_monitor(struct ieee80211_rx_data *rx)
1581 {
1582         struct ieee80211_sub_if_data *sdata;
1583         struct ieee80211_local *local = rx->local;
1584         struct ieee80211_rtap_hdr {
1585                 struct ieee80211_radiotap_header hdr;
1586                 u8 flags;
1587                 u8 rate;
1588                 __le16 chan_freq;
1589                 __le16 chan_flags;
1590         } __attribute__ ((packed)) *rthdr;
1591         struct sk_buff *skb = rx->skb, *skb2;
1592         struct net_device *prev_dev = NULL;
1593         struct ieee80211_rx_status *status = rx->status;
1594
1595         if (rx->flags & IEEE80211_RX_CMNTR_REPORTED)
1596                 goto out_free_skb;
1597
1598         if (skb_headroom(skb) < sizeof(*rthdr) &&
1599             pskb_expand_head(skb, sizeof(*rthdr), 0, GFP_ATOMIC))
1600                 goto out_free_skb;
1601
1602         rthdr = (void *)skb_push(skb, sizeof(*rthdr));
1603         memset(rthdr, 0, sizeof(*rthdr));
1604         rthdr->hdr.it_len = cpu_to_le16(sizeof(*rthdr));
1605         rthdr->hdr.it_present =
1606                 cpu_to_le32((1 << IEEE80211_RADIOTAP_FLAGS) |
1607                             (1 << IEEE80211_RADIOTAP_RATE) |
1608                             (1 << IEEE80211_RADIOTAP_CHANNEL));
1609
1610         rthdr->rate = rx->rate->bitrate / 5;
1611         rthdr->chan_freq = cpu_to_le16(status->freq);
1612
1613         if (status->band == IEEE80211_BAND_5GHZ)
1614                 rthdr->chan_flags = cpu_to_le16(IEEE80211_CHAN_OFDM |
1615                                                 IEEE80211_CHAN_5GHZ);
1616         else
1617                 rthdr->chan_flags = cpu_to_le16(IEEE80211_CHAN_DYN |
1618                                                 IEEE80211_CHAN_2GHZ);
1619
1620         skb_set_mac_header(skb, 0);
1621         skb->ip_summed = CHECKSUM_UNNECESSARY;
1622         skb->pkt_type = PACKET_OTHERHOST;
1623         skb->protocol = htons(ETH_P_802_2);
1624
1625         list_for_each_entry_rcu(sdata, &local->interfaces, list) {
1626                 if (!netif_running(sdata->dev))
1627                         continue;
1628
1629                 if (sdata->vif.type != IEEE80211_IF_TYPE_MNTR ||
1630                     !(sdata->u.mntr_flags & MONITOR_FLAG_COOK_FRAMES))
1631                         continue;
1632
1633                 if (prev_dev) {
1634                         skb2 = skb_clone(skb, GFP_ATOMIC);
1635                         if (skb2) {
1636                                 skb2->dev = prev_dev;
1637                                 netif_rx(skb2);
1638                         }
1639                 }
1640
1641                 prev_dev = sdata->dev;
1642                 sdata->dev->stats.rx_packets++;
1643                 sdata->dev->stats.rx_bytes += skb->len;
1644         }
1645
1646         if (prev_dev) {
1647                 skb->dev = prev_dev;
1648                 netif_rx(skb);
1649                 skb = NULL;
1650         } else
1651                 goto out_free_skb;
1652
1653         rx->flags |= IEEE80211_RX_CMNTR_REPORTED;
1654         return;
1655
1656  out_free_skb:
1657         dev_kfree_skb(skb);
1658 }
1659
1660
1661 static void ieee80211_invoke_rx_handlers(struct ieee80211_sub_if_data *sdata,
1662                                          struct ieee80211_rx_data *rx,
1663                                          struct sk_buff *skb)
1664 {
1665         ieee80211_rx_result res = RX_DROP_MONITOR;
1666
1667         rx->skb = skb;
1668         rx->sdata = sdata;
1669         rx->dev = sdata->dev;
1670
1671 #define CALL_RXH(rxh)                   \
1672         do {                            \
1673                 res = rxh(rx);          \
1674                 if (res != RX_CONTINUE) \
1675                         goto rxh_done;  \
1676         } while (0);
1677
1678         CALL_RXH(ieee80211_rx_h_passive_scan)
1679         CALL_RXH(ieee80211_rx_h_check)
1680         CALL_RXH(ieee80211_rx_h_decrypt)
1681         CALL_RXH(ieee80211_rx_h_sta_process)
1682         CALL_RXH(ieee80211_rx_h_defragment)
1683         CALL_RXH(ieee80211_rx_h_ps_poll)
1684         CALL_RXH(ieee80211_rx_h_michael_mic_verify)
1685         /* must be after MMIC verify so header is counted in MPDU mic */
1686         CALL_RXH(ieee80211_rx_h_remove_qos_control)
1687         CALL_RXH(ieee80211_rx_h_amsdu)
1688         if (ieee80211_vif_is_mesh(&sdata->vif))
1689                 CALL_RXH(ieee80211_rx_h_mesh_fwding);
1690         CALL_RXH(ieee80211_rx_h_data)
1691         CALL_RXH(ieee80211_rx_h_ctrl)
1692         CALL_RXH(ieee80211_rx_h_mgmt)
1693
1694 #undef CALL_RXH
1695
1696  rxh_done:
1697         switch (res) {
1698         case RX_DROP_MONITOR:
1699                 I802_DEBUG_INC(sdata->local->rx_handlers_drop);
1700                 if (rx->sta)
1701                         rx->sta->rx_dropped++;
1702                 /* fall through */
1703         case RX_CONTINUE:
1704                 ieee80211_rx_cooked_monitor(rx);
1705                 break;
1706         case RX_DROP_UNUSABLE:
1707                 I802_DEBUG_INC(sdata->local->rx_handlers_drop);
1708                 if (rx->sta)
1709                         rx->sta->rx_dropped++;
1710                 dev_kfree_skb(rx->skb);
1711                 break;
1712         case RX_QUEUED:
1713                 I802_DEBUG_INC(sdata->local->rx_handlers_queued);
1714                 break;
1715         }
1716 }
1717
1718 /* main receive path */
1719
1720 static int prepare_for_handlers(struct ieee80211_sub_if_data *sdata,
1721                                 u8 *bssid, struct ieee80211_rx_data *rx,
1722                                 struct ieee80211_hdr *hdr)
1723 {
1724         int multicast = is_multicast_ether_addr(hdr->addr1);
1725
1726         switch (sdata->vif.type) {
1727         case IEEE80211_IF_TYPE_STA:
1728                 if (!bssid)
1729                         return 0;
1730                 if (!ieee80211_bssid_match(bssid, sdata->u.sta.bssid)) {
1731                         if (!(rx->flags & IEEE80211_RX_IN_SCAN))
1732                                 return 0;
1733                         rx->flags &= ~IEEE80211_RX_RA_MATCH;
1734                 } else if (!multicast &&
1735                            compare_ether_addr(sdata->dev->dev_addr,
1736                                               hdr->addr1) != 0) {
1737                         if (!(sdata->dev->flags & IFF_PROMISC))
1738                                 return 0;
1739                         rx->flags &= ~IEEE80211_RX_RA_MATCH;
1740                 }
1741                 break;
1742         case IEEE80211_IF_TYPE_IBSS:
1743                 if (!bssid)
1744                         return 0;
1745                 if (ieee80211_is_beacon(hdr->frame_control)) {
1746                         if (!rx->sta)
1747                                 rx->sta = ieee80211_ibss_add_sta(sdata->dev,
1748                                                 rx->skb, bssid, hdr->addr2,
1749                                                 BIT(rx->status->rate_idx));
1750                         return 1;
1751                 }
1752                 else if (!ieee80211_bssid_match(bssid, sdata->u.sta.bssid)) {
1753                         if (!(rx->flags & IEEE80211_RX_IN_SCAN))
1754                                 return 0;
1755                         rx->flags &= ~IEEE80211_RX_RA_MATCH;
1756                 } else if (!multicast &&
1757                            compare_ether_addr(sdata->dev->dev_addr,
1758                                               hdr->addr1) != 0) {
1759                         if (!(sdata->dev->flags & IFF_PROMISC))
1760                                 return 0;
1761                         rx->flags &= ~IEEE80211_RX_RA_MATCH;
1762                 } else if (!rx->sta)
1763                         rx->sta = ieee80211_ibss_add_sta(sdata->dev, rx->skb,
1764                                                 bssid, hdr->addr2,
1765                                                 BIT(rx->status->rate_idx));
1766                 break;
1767         case IEEE80211_IF_TYPE_MESH_POINT:
1768                 if (!multicast &&
1769                     compare_ether_addr(sdata->dev->dev_addr,
1770                                        hdr->addr1) != 0) {
1771                         if (!(sdata->dev->flags & IFF_PROMISC))
1772                                 return 0;
1773
1774                         rx->flags &= ~IEEE80211_RX_RA_MATCH;
1775                 }
1776                 break;
1777         case IEEE80211_IF_TYPE_VLAN:
1778         case IEEE80211_IF_TYPE_AP:
1779                 if (!bssid) {
1780                         if (compare_ether_addr(sdata->dev->dev_addr,
1781                                                hdr->addr1))
1782                                 return 0;
1783                 } else if (!ieee80211_bssid_match(bssid,
1784                                         sdata->dev->dev_addr)) {
1785                         if (!(rx->flags & IEEE80211_RX_IN_SCAN))
1786                                 return 0;
1787                         rx->flags &= ~IEEE80211_RX_RA_MATCH;
1788                 }
1789                 break;
1790         case IEEE80211_IF_TYPE_WDS:
1791                 if (bssid || !ieee80211_is_data(hdr->frame_control))
1792                         return 0;
1793                 if (compare_ether_addr(sdata->u.wds.remote_addr, hdr->addr2))
1794                         return 0;
1795                 break;
1796         case IEEE80211_IF_TYPE_MNTR:
1797                 /* take everything */
1798                 break;
1799         case IEEE80211_IF_TYPE_INVALID:
1800                 /* should never get here */
1801                 WARN_ON(1);
1802                 break;
1803         }
1804
1805         return 1;
1806 }
1807
1808 /*
1809  * This is the actual Rx frames handler. as it blongs to Rx path it must
1810  * be called with rcu_read_lock protection.
1811  */
1812 static void __ieee80211_rx_handle_packet(struct ieee80211_hw *hw,
1813                                          struct sk_buff *skb,
1814                                          struct ieee80211_rx_status *status,
1815                                          struct ieee80211_rate *rate)
1816 {
1817         struct ieee80211_local *local = hw_to_local(hw);
1818         struct ieee80211_sub_if_data *sdata;
1819         struct ieee80211_hdr *hdr;
1820         struct ieee80211_rx_data rx;
1821         int prepares;
1822         struct ieee80211_sub_if_data *prev = NULL;
1823         struct sk_buff *skb_new;
1824         u8 *bssid;
1825
1826         hdr = (struct ieee80211_hdr *)skb->data;
1827         memset(&rx, 0, sizeof(rx));
1828         rx.skb = skb;
1829         rx.local = local;
1830
1831         rx.status = status;
1832         rx.rate = rate;
1833
1834         if (ieee80211_is_data(hdr->frame_control) || ieee80211_is_mgmt(hdr->frame_control))
1835                 local->dot11ReceivedFragmentCount++;
1836
1837         rx.sta = sta_info_get(local, hdr->addr2);
1838         if (rx.sta) {
1839                 rx.sdata = rx.sta->sdata;
1840                 rx.dev = rx.sta->sdata->dev;
1841         }
1842
1843         if ((status->flag & RX_FLAG_MMIC_ERROR)) {
1844                 ieee80211_rx_michael_mic_report(local->mdev, hdr, &rx);
1845                 return;
1846         }
1847
1848         if (unlikely(local->sta_sw_scanning || local->sta_hw_scanning))
1849                 rx.flags |= IEEE80211_RX_IN_SCAN;
1850
1851         ieee80211_parse_qos(&rx);
1852         ieee80211_verify_ip_alignment(&rx);
1853
1854         skb = rx.skb;
1855
1856         list_for_each_entry_rcu(sdata, &local->interfaces, list) {
1857                 if (!netif_running(sdata->dev))
1858                         continue;
1859
1860                 if (sdata->vif.type == IEEE80211_IF_TYPE_MNTR)
1861                         continue;
1862
1863                 bssid = ieee80211_get_bssid(hdr, skb->len, sdata->vif.type);
1864                 rx.flags |= IEEE80211_RX_RA_MATCH;
1865                 prepares = prepare_for_handlers(sdata, bssid, &rx, hdr);
1866
1867                 if (!prepares)
1868                         continue;
1869
1870                 /*
1871                  * frame is destined for this interface, but if it's not
1872                  * also for the previous one we handle that after the
1873                  * loop to avoid copying the SKB once too much
1874                  */
1875
1876                 if (!prev) {
1877                         prev = sdata;
1878                         continue;
1879                 }
1880
1881                 /*
1882                  * frame was destined for the previous interface
1883                  * so invoke RX handlers for it
1884                  */
1885
1886                 skb_new = skb_copy(skb, GFP_ATOMIC);
1887                 if (!skb_new) {
1888                         if (net_ratelimit())
1889                                 printk(KERN_DEBUG "%s: failed to copy "
1890                                        "multicast frame for %s\n",
1891                                        wiphy_name(local->hw.wiphy),
1892                                        prev->dev->name);
1893                         continue;
1894                 }
1895                 ieee80211_invoke_rx_handlers(prev, &rx, skb_new);
1896                 prev = sdata;
1897         }
1898         if (prev)
1899                 ieee80211_invoke_rx_handlers(prev, &rx, skb);
1900         else
1901                 dev_kfree_skb(skb);
1902 }
1903
1904 #define SEQ_MODULO 0x1000
1905 #define SEQ_MASK   0xfff
1906
1907 static inline int seq_less(u16 sq1, u16 sq2)
1908 {
1909         return (((sq1 - sq2) & SEQ_MASK) > (SEQ_MODULO >> 1));
1910 }
1911
1912 static inline u16 seq_inc(u16 sq)
1913 {
1914         return ((sq + 1) & SEQ_MASK);
1915 }
1916
1917 static inline u16 seq_sub(u16 sq1, u16 sq2)
1918 {
1919         return ((sq1 - sq2) & SEQ_MASK);
1920 }
1921
1922
1923 /*
1924  * As it function blongs to Rx path it must be called with
1925  * the proper rcu_read_lock protection for its flow.
1926  */
1927 u8 ieee80211_sta_manage_reorder_buf(struct ieee80211_hw *hw,
1928                                 struct tid_ampdu_rx *tid_agg_rx,
1929                                 struct sk_buff *skb, u16 mpdu_seq_num,
1930                                 int bar_req)
1931 {
1932         struct ieee80211_local *local = hw_to_local(hw);
1933         struct ieee80211_rx_status status;
1934         u16 head_seq_num, buf_size;
1935         int index;
1936         struct ieee80211_supported_band *sband;
1937         struct ieee80211_rate *rate;
1938
1939         buf_size = tid_agg_rx->buf_size;
1940         head_seq_num = tid_agg_rx->head_seq_num;
1941
1942         /* frame with out of date sequence number */
1943         if (seq_less(mpdu_seq_num, head_seq_num)) {
1944                 dev_kfree_skb(skb);
1945                 return 1;
1946         }
1947
1948         /* if frame sequence number exceeds our buffering window size or
1949          * block Ack Request arrived - release stored frames */
1950         if ((!seq_less(mpdu_seq_num, head_seq_num + buf_size)) || (bar_req)) {
1951                 /* new head to the ordering buffer */
1952                 if (bar_req)
1953                         head_seq_num = mpdu_seq_num;
1954                 else
1955                         head_seq_num =
1956                                 seq_inc(seq_sub(mpdu_seq_num, buf_size));
1957                 /* release stored frames up to new head to stack */
1958                 while (seq_less(tid_agg_rx->head_seq_num, head_seq_num)) {
1959                         index = seq_sub(tid_agg_rx->head_seq_num,
1960                                 tid_agg_rx->ssn)
1961                                 % tid_agg_rx->buf_size;
1962
1963                         if (tid_agg_rx->reorder_buf[index]) {
1964                                 /* release the reordered frames to stack */
1965                                 memcpy(&status,
1966                                         tid_agg_rx->reorder_buf[index]->cb,
1967                                         sizeof(status));
1968                                 sband = local->hw.wiphy->bands[status.band];
1969                                 rate = &sband->bitrates[status.rate_idx];
1970                                 __ieee80211_rx_handle_packet(hw,
1971                                         tid_agg_rx->reorder_buf[index],
1972                                         &status, rate);
1973                                 tid_agg_rx->stored_mpdu_num--;
1974                                 tid_agg_rx->reorder_buf[index] = NULL;
1975                         }
1976                         tid_agg_rx->head_seq_num =
1977                                 seq_inc(tid_agg_rx->head_seq_num);
1978                 }
1979                 if (bar_req)
1980                         return 1;
1981         }
1982
1983         /* now the new frame is always in the range of the reordering */
1984         /* buffer window */
1985         index = seq_sub(mpdu_seq_num, tid_agg_rx->ssn)
1986                                 % tid_agg_rx->buf_size;
1987         /* check if we already stored this frame */
1988         if (tid_agg_rx->reorder_buf[index]) {
1989                 dev_kfree_skb(skb);
1990                 return 1;
1991         }
1992
1993         /* if arrived mpdu is in the right order and nothing else stored */
1994         /* release it immediately */
1995         if (mpdu_seq_num == tid_agg_rx->head_seq_num &&
1996                         tid_agg_rx->stored_mpdu_num == 0) {
1997                 tid_agg_rx->head_seq_num =
1998                         seq_inc(tid_agg_rx->head_seq_num);
1999                 return 0;
2000         }
2001
2002         /* put the frame in the reordering buffer */
2003         tid_agg_rx->reorder_buf[index] = skb;
2004         tid_agg_rx->stored_mpdu_num++;
2005         /* release the buffer until next missing frame */
2006         index = seq_sub(tid_agg_rx->head_seq_num, tid_agg_rx->ssn)
2007                                                 % tid_agg_rx->buf_size;
2008         while (tid_agg_rx->reorder_buf[index]) {
2009                 /* release the reordered frame back to stack */
2010                 memcpy(&status, tid_agg_rx->reorder_buf[index]->cb,
2011                         sizeof(status));
2012                 sband = local->hw.wiphy->bands[status.band];
2013                 rate = &sband->bitrates[status.rate_idx];
2014                 __ieee80211_rx_handle_packet(hw, tid_agg_rx->reorder_buf[index],
2015                                              &status, rate);
2016                 tid_agg_rx->stored_mpdu_num--;
2017                 tid_agg_rx->reorder_buf[index] = NULL;
2018                 tid_agg_rx->head_seq_num = seq_inc(tid_agg_rx->head_seq_num);
2019                 index = seq_sub(tid_agg_rx->head_seq_num,
2020                         tid_agg_rx->ssn) % tid_agg_rx->buf_size;
2021         }
2022         return 1;
2023 }
2024
2025 static u8 ieee80211_rx_reorder_ampdu(struct ieee80211_local *local,
2026                                      struct sk_buff *skb)
2027 {
2028         struct ieee80211_hw *hw = &local->hw;
2029         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
2030         struct sta_info *sta;
2031         struct tid_ampdu_rx *tid_agg_rx;
2032         u16 sc;
2033         u16 mpdu_seq_num;
2034         u8 ret = 0;
2035         int tid;
2036
2037         sta = sta_info_get(local, hdr->addr2);
2038         if (!sta)
2039                 return ret;
2040
2041         /* filter the QoS data rx stream according to
2042          * STA/TID and check if this STA/TID is on aggregation */
2043         if (!ieee80211_is_data_qos(hdr->frame_control))
2044                 goto end_reorder;
2045
2046         tid = *ieee80211_get_qos_ctl(hdr) & IEEE80211_QOS_CTL_TID_MASK;
2047
2048         if (sta->ampdu_mlme.tid_state_rx[tid] != HT_AGG_STATE_OPERATIONAL)
2049                 goto end_reorder;
2050
2051         tid_agg_rx = sta->ampdu_mlme.tid_rx[tid];
2052
2053         /* qos null data frames are excluded */
2054         if (unlikely(hdr->frame_control & cpu_to_le16(IEEE80211_STYPE_NULLFUNC)))
2055                 goto end_reorder;
2056
2057         /* new un-ordered ampdu frame - process it */
2058
2059         /* reset session timer */
2060         if (tid_agg_rx->timeout) {
2061                 unsigned long expires =
2062                         jiffies + (tid_agg_rx->timeout / 1000) * HZ;
2063                 mod_timer(&tid_agg_rx->session_timer, expires);
2064         }
2065
2066         /* if this mpdu is fragmented - terminate rx aggregation session */
2067         sc = le16_to_cpu(hdr->seq_ctrl);
2068         if (sc & IEEE80211_SCTL_FRAG) {
2069                 ieee80211_sta_stop_rx_ba_session(sta->sdata->dev, sta->addr,
2070                         tid, 0, WLAN_REASON_QSTA_REQUIRE_SETUP);
2071                 ret = 1;
2072                 goto end_reorder;
2073         }
2074
2075         /* according to mpdu sequence number deal with reordering buffer */
2076         mpdu_seq_num = (sc & IEEE80211_SCTL_SEQ) >> 4;
2077         ret = ieee80211_sta_manage_reorder_buf(hw, tid_agg_rx, skb,
2078                                                 mpdu_seq_num, 0);
2079  end_reorder:
2080         return ret;
2081 }
2082
2083 /*
2084  * This is the receive path handler. It is called by a low level driver when an
2085  * 802.11 MPDU is received from the hardware.
2086  */
2087 void __ieee80211_rx(struct ieee80211_hw *hw, struct sk_buff *skb,
2088                     struct ieee80211_rx_status *status)
2089 {
2090         struct ieee80211_local *local = hw_to_local(hw);
2091         struct ieee80211_rate *rate = NULL;
2092         struct ieee80211_supported_band *sband;
2093
2094         if (status->band < 0 ||
2095             status->band >= IEEE80211_NUM_BANDS) {
2096                 WARN_ON(1);
2097                 return;
2098         }
2099
2100         sband = local->hw.wiphy->bands[status->band];
2101
2102         if (!sband ||
2103             status->rate_idx < 0 ||
2104             status->rate_idx >= sband->n_bitrates) {
2105                 WARN_ON(1);
2106                 return;
2107         }
2108
2109         rate = &sband->bitrates[status->rate_idx];
2110
2111         /*
2112          * key references and virtual interfaces are protected using RCU
2113          * and this requires that we are in a read-side RCU section during
2114          * receive processing
2115          */
2116         rcu_read_lock();
2117
2118         /*
2119          * Frames with failed FCS/PLCP checksum are not returned,
2120          * all other frames are returned without radiotap header
2121          * if it was previously present.
2122          * Also, frames with less than 16 bytes are dropped.
2123          */
2124         skb = ieee80211_rx_monitor(local, skb, status, rate);
2125         if (!skb) {
2126                 rcu_read_unlock();
2127                 return;
2128         }
2129
2130         if (!ieee80211_rx_reorder_ampdu(local, skb))
2131                 __ieee80211_rx_handle_packet(hw, skb, status, rate);
2132
2133         rcu_read_unlock();
2134 }
2135 EXPORT_SYMBOL(__ieee80211_rx);
2136
2137 /* This is a version of the rx handler that can be called from hard irq
2138  * context. Post the skb on the queue and schedule the tasklet */
2139 void ieee80211_rx_irqsafe(struct ieee80211_hw *hw, struct sk_buff *skb,
2140                           struct ieee80211_rx_status *status)
2141 {
2142         struct ieee80211_local *local = hw_to_local(hw);
2143
2144         BUILD_BUG_ON(sizeof(struct ieee80211_rx_status) > sizeof(skb->cb));
2145
2146         skb->dev = local->mdev;
2147         /* copy status into skb->cb for use by tasklet */
2148         memcpy(skb->cb, status, sizeof(*status));
2149         skb->pkt_type = IEEE80211_RX_MSG;
2150         skb_queue_tail(&local->skb_queue, skb);
2151         tasklet_schedule(&local->tasklet);
2152 }
2153 EXPORT_SYMBOL(ieee80211_rx_irqsafe);