mac80211: document ieee80211_rx() context requirement
[linux-2.6.git] / net / mac80211 / rx.c
1 /*
2  * Copyright 2002-2005, Instant802 Networks, Inc.
3  * Copyright 2005-2006, Devicescape Software, Inc.
4  * Copyright 2006-2007  Jiri Benc <jbenc@suse.cz>
5  * Copyright 2007       Johannes Berg <johannes@sipsolutions.net>
6  *
7  * This program is free software; you can redistribute it and/or modify
8  * it under the terms of the GNU General Public License version 2 as
9  * published by the Free Software Foundation.
10  */
11
12 #include <linux/jiffies.h>
13 #include <linux/kernel.h>
14 #include <linux/skbuff.h>
15 #include <linux/netdevice.h>
16 #include <linux/etherdevice.h>
17 #include <linux/rcupdate.h>
18 #include <net/mac80211.h>
19 #include <net/ieee80211_radiotap.h>
20
21 #include "ieee80211_i.h"
22 #include "driver-ops.h"
23 #include "led.h"
24 #include "mesh.h"
25 #include "wep.h"
26 #include "wpa.h"
27 #include "tkip.h"
28 #include "wme.h"
29
30 static u8 ieee80211_sta_manage_reorder_buf(struct ieee80211_hw *hw,
31                                            struct tid_ampdu_rx *tid_agg_rx,
32                                            struct sk_buff *skb,
33                                            u16 mpdu_seq_num,
34                                            int bar_req);
35 /*
36  * monitor mode reception
37  *
38  * This function cleans up the SKB, i.e. it removes all the stuff
39  * only useful for monitoring.
40  */
41 static struct sk_buff *remove_monitor_info(struct ieee80211_local *local,
42                                            struct sk_buff *skb,
43                                            int rtap_len)
44 {
45         skb_pull(skb, rtap_len);
46
47         if (local->hw.flags & IEEE80211_HW_RX_INCLUDES_FCS) {
48                 if (likely(skb->len > FCS_LEN))
49                         skb_trim(skb, skb->len - FCS_LEN);
50                 else {
51                         /* driver bug */
52                         WARN_ON(1);
53                         dev_kfree_skb(skb);
54                         skb = NULL;
55                 }
56         }
57
58         return skb;
59 }
60
61 static inline int should_drop_frame(struct sk_buff *skb,
62                                     int present_fcs_len,
63                                     int radiotap_len)
64 {
65         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
66         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
67
68         if (status->flag & (RX_FLAG_FAILED_FCS_CRC | RX_FLAG_FAILED_PLCP_CRC))
69                 return 1;
70         if (unlikely(skb->len < 16 + present_fcs_len + radiotap_len))
71                 return 1;
72         if (ieee80211_is_ctl(hdr->frame_control) &&
73             !ieee80211_is_pspoll(hdr->frame_control) &&
74             !ieee80211_is_back_req(hdr->frame_control))
75                 return 1;
76         return 0;
77 }
78
79 static int
80 ieee80211_rx_radiotap_len(struct ieee80211_local *local,
81                           struct ieee80211_rx_status *status)
82 {
83         int len;
84
85         /* always present fields */
86         len = sizeof(struct ieee80211_radiotap_header) + 9;
87
88         if (status->flag & RX_FLAG_TSFT)
89                 len += 8;
90         if (local->hw.flags & IEEE80211_HW_SIGNAL_DBM)
91                 len += 1;
92         if (local->hw.flags & IEEE80211_HW_NOISE_DBM)
93                 len += 1;
94
95         if (len & 1) /* padding for RX_FLAGS if necessary */
96                 len++;
97
98         /* make sure radiotap starts at a naturally aligned address */
99         if (len % 8)
100                 len = roundup(len, 8);
101
102         return len;
103 }
104
105 /*
106  * ieee80211_add_rx_radiotap_header - add radiotap header
107  *
108  * add a radiotap header containing all the fields which the hardware provided.
109  */
110 static void
111 ieee80211_add_rx_radiotap_header(struct ieee80211_local *local,
112                                  struct sk_buff *skb,
113                                  struct ieee80211_rate *rate,
114                                  int rtap_len)
115 {
116         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
117         struct ieee80211_radiotap_header *rthdr;
118         unsigned char *pos;
119
120         rthdr = (struct ieee80211_radiotap_header *)skb_push(skb, rtap_len);
121         memset(rthdr, 0, rtap_len);
122
123         /* radiotap header, set always present flags */
124         rthdr->it_present =
125                 cpu_to_le32((1 << IEEE80211_RADIOTAP_FLAGS) |
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_FAILED_FCS_CRC | RX_FLAG_FAILED_PLCP_CRC))
147                 *pos |= IEEE80211_RADIOTAP_F_BADFCS;
148         if (status->flag & RX_FLAG_SHORTPRE)
149                 *pos |= IEEE80211_RADIOTAP_F_SHORTPRE;
150         pos++;
151
152         /* IEEE80211_RADIOTAP_RATE */
153         if (status->flag & RX_FLAG_HT) {
154                 /*
155                  * TODO: add following information into radiotap header once
156                  * suitable fields are defined for it:
157                  * - MCS index (status->rate_idx)
158                  * - HT40 (status->flag & RX_FLAG_40MHZ)
159                  * - short-GI (status->flag & RX_FLAG_SHORT_GI)
160                  */
161                 *pos = 0;
162         } else {
163                 rthdr->it_present |= cpu_to_le32(1 << IEEE80211_RADIOTAP_RATE);
164                 *pos = rate->bitrate / 5;
165         }
166         pos++;
167
168         /* IEEE80211_RADIOTAP_CHANNEL */
169         *(__le16 *)pos = cpu_to_le16(status->freq);
170         pos += 2;
171         if (status->band == IEEE80211_BAND_5GHZ)
172                 *(__le16 *)pos = cpu_to_le16(IEEE80211_CHAN_OFDM |
173                                              IEEE80211_CHAN_5GHZ);
174         else if (rate->flags & IEEE80211_RATE_ERP_G)
175                 *(__le16 *)pos = cpu_to_le16(IEEE80211_CHAN_OFDM |
176                                              IEEE80211_CHAN_2GHZ);
177         else
178                 *(__le16 *)pos = cpu_to_le16(IEEE80211_CHAN_CCK |
179                                              IEEE80211_CHAN_2GHZ);
180         pos += 2;
181
182         /* IEEE80211_RADIOTAP_DBM_ANTSIGNAL */
183         if (local->hw.flags & IEEE80211_HW_SIGNAL_DBM) {
184                 *pos = status->signal;
185                 rthdr->it_present |=
186                         cpu_to_le32(1 << IEEE80211_RADIOTAP_DBM_ANTSIGNAL);
187                 pos++;
188         }
189
190         /* IEEE80211_RADIOTAP_DBM_ANTNOISE */
191         if (local->hw.flags & IEEE80211_HW_NOISE_DBM) {
192                 *pos = status->noise;
193                 rthdr->it_present |=
194                         cpu_to_le32(1 << IEEE80211_RADIOTAP_DBM_ANTNOISE);
195                 pos++;
196         }
197
198         /* IEEE80211_RADIOTAP_LOCK_QUALITY is missing */
199
200         /* IEEE80211_RADIOTAP_ANTENNA */
201         *pos = status->antenna;
202         pos++;
203
204         /* IEEE80211_RADIOTAP_DB_ANTNOISE is not used */
205
206         /* IEEE80211_RADIOTAP_RX_FLAGS */
207         /* ensure 2 byte alignment for the 2 byte field as required */
208         if ((pos - (unsigned char *)rthdr) & 1)
209                 pos++;
210         if (status->flag & RX_FLAG_FAILED_PLCP_CRC)
211                 *(__le16 *)pos |= cpu_to_le16(IEEE80211_RADIOTAP_F_RX_BADPLCP);
212         pos += 2;
213 }
214
215 /*
216  * This function copies a received frame to all monitor interfaces and
217  * returns a cleaned-up SKB that no longer includes the FCS nor the
218  * radiotap header the driver might have added.
219  */
220 static struct sk_buff *
221 ieee80211_rx_monitor(struct ieee80211_local *local, struct sk_buff *origskb,
222                      struct ieee80211_rate *rate)
223 {
224         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(origskb);
225         struct ieee80211_sub_if_data *sdata;
226         int needed_headroom = 0;
227         struct sk_buff *skb, *skb2;
228         struct net_device *prev_dev = NULL;
229         int present_fcs_len = 0;
230         int rtap_len = 0;
231
232         /*
233          * First, we may need to make a copy of the skb because
234          *  (1) we need to modify it for radiotap (if not present), and
235          *  (2) the other RX handlers will modify the skb we got.
236          *
237          * We don't need to, of course, if we aren't going to return
238          * the SKB because it has a bad FCS/PLCP checksum.
239          */
240         if (status->flag & RX_FLAG_RADIOTAP)
241                 rtap_len = ieee80211_get_radiotap_len(origskb->data);
242         else
243                 /* room for the radiotap header based on driver features */
244                 needed_headroom = ieee80211_rx_radiotap_len(local, status);
245
246         if (local->hw.flags & IEEE80211_HW_RX_INCLUDES_FCS)
247                 present_fcs_len = FCS_LEN;
248
249         if (!local->monitors) {
250                 if (should_drop_frame(origskb, present_fcs_len, rtap_len)) {
251                         dev_kfree_skb(origskb);
252                         return NULL;
253                 }
254
255                 return remove_monitor_info(local, origskb, rtap_len);
256         }
257
258         if (should_drop_frame(origskb, present_fcs_len, rtap_len)) {
259                 /* only need to expand headroom if necessary */
260                 skb = origskb;
261                 origskb = NULL;
262
263                 /*
264                  * This shouldn't trigger often because most devices have an
265                  * RX header they pull before we get here, and that should
266                  * be big enough for our radiotap information. We should
267                  * probably export the length to drivers so that we can have
268                  * them allocate enough headroom to start with.
269                  */
270                 if (skb_headroom(skb) < needed_headroom &&
271                     pskb_expand_head(skb, needed_headroom, 0, GFP_ATOMIC)) {
272                         dev_kfree_skb(skb);
273                         return NULL;
274                 }
275         } else {
276                 /*
277                  * Need to make a copy and possibly remove radiotap header
278                  * and FCS from the original.
279                  */
280                 skb = skb_copy_expand(origskb, needed_headroom, 0, GFP_ATOMIC);
281
282                 origskb = remove_monitor_info(local, origskb, rtap_len);
283
284                 if (!skb)
285                         return origskb;
286         }
287
288         /* if necessary, prepend radiotap information */
289         if (!(status->flag & RX_FLAG_RADIOTAP))
290                 ieee80211_add_rx_radiotap_header(local, skb, rate,
291                                                  needed_headroom);
292
293         skb_reset_mac_header(skb);
294         skb->ip_summed = CHECKSUM_UNNECESSARY;
295         skb->pkt_type = PACKET_OTHERHOST;
296         skb->protocol = htons(ETH_P_802_2);
297
298         list_for_each_entry_rcu(sdata, &local->interfaces, list) {
299                 if (!netif_running(sdata->dev))
300                         continue;
301
302                 if (sdata->vif.type != NL80211_IFTYPE_MONITOR)
303                         continue;
304
305                 if (sdata->u.mntr_flags & MONITOR_FLAG_COOK_FRAMES)
306                         continue;
307
308                 if (prev_dev) {
309                         skb2 = skb_clone(skb, GFP_ATOMIC);
310                         if (skb2) {
311                                 skb2->dev = prev_dev;
312                                 netif_rx(skb2);
313                         }
314                 }
315
316                 prev_dev = sdata->dev;
317                 sdata->dev->stats.rx_packets++;
318                 sdata->dev->stats.rx_bytes += skb->len;
319         }
320
321         if (prev_dev) {
322                 skb->dev = prev_dev;
323                 netif_rx(skb);
324         } else
325                 dev_kfree_skb(skb);
326
327         return origskb;
328 }
329
330
331 static void ieee80211_parse_qos(struct ieee80211_rx_data *rx)
332 {
333         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
334         int tid;
335
336         /* does the frame have a qos control field? */
337         if (ieee80211_is_data_qos(hdr->frame_control)) {
338                 u8 *qc = ieee80211_get_qos_ctl(hdr);
339                 /* frame has qos control */
340                 tid = *qc & IEEE80211_QOS_CTL_TID_MASK;
341                 if (*qc & IEEE80211_QOS_CONTROL_A_MSDU_PRESENT)
342                         rx->flags |= IEEE80211_RX_AMSDU;
343                 else
344                         rx->flags &= ~IEEE80211_RX_AMSDU;
345         } else {
346                 /*
347                  * IEEE 802.11-2007, 7.1.3.4.1 ("Sequence Number field"):
348                  *
349                  *      Sequence numbers for management frames, QoS data
350                  *      frames with a broadcast/multicast address in the
351                  *      Address 1 field, and all non-QoS data frames sent
352                  *      by QoS STAs are assigned using an additional single
353                  *      modulo-4096 counter, [...]
354                  *
355                  * We also use that counter for non-QoS STAs.
356                  */
357                 tid = NUM_RX_DATA_QUEUES - 1;
358         }
359
360         rx->queue = tid;
361         /* Set skb->priority to 1d tag if highest order bit of TID is not set.
362          * For now, set skb->priority to 0 for other cases. */
363         rx->skb->priority = (tid > 7) ? 0 : tid;
364 }
365
366 /**
367  * DOC: Packet alignment
368  *
369  * Drivers always need to pass packets that are aligned to two-byte boundaries
370  * to the stack.
371  *
372  * Additionally, should, if possible, align the payload data in a way that
373  * guarantees that the contained IP header is aligned to a four-byte
374  * boundary. In the case of regular frames, this simply means aligning the
375  * payload to a four-byte boundary (because either the IP header is directly
376  * contained, or IV/RFC1042 headers that have a length divisible by four are
377  * in front of it).
378  *
379  * With A-MSDU frames, however, the payload data address must yield two modulo
380  * four because there are 14-byte 802.3 headers within the A-MSDU frames that
381  * push the IP header further back to a multiple of four again. Thankfully, the
382  * specs were sane enough this time around to require padding each A-MSDU
383  * subframe to a length that is a multiple of four.
384  *
385  * Padding like Atheros hardware adds which is inbetween the 802.11 header and
386  * the payload is not supported, the driver is required to move the 802.11
387  * header to be directly in front of the payload in that case.
388  */
389 static void ieee80211_verify_alignment(struct ieee80211_rx_data *rx)
390 {
391         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
392         int hdrlen;
393
394 #ifndef CONFIG_MAC80211_DEBUG_PACKET_ALIGNMENT
395         return;
396 #endif
397
398         if (WARN_ONCE((unsigned long)rx->skb->data & 1,
399                       "unaligned packet at 0x%p\n", rx->skb->data))
400                 return;
401
402         if (!ieee80211_is_data_present(hdr->frame_control))
403                 return;
404
405         hdrlen = ieee80211_hdrlen(hdr->frame_control);
406         if (rx->flags & IEEE80211_RX_AMSDU)
407                 hdrlen += ETH_HLEN;
408         WARN_ONCE(((unsigned long)(rx->skb->data + hdrlen)) & 3,
409                   "unaligned IP payload at 0x%p\n", rx->skb->data + hdrlen);
410 }
411
412
413 /* rx handlers */
414
415 static ieee80211_rx_result debug_noinline
416 ieee80211_rx_h_passive_scan(struct ieee80211_rx_data *rx)
417 {
418         struct ieee80211_local *local = rx->local;
419         struct sk_buff *skb = rx->skb;
420
421         if (unlikely(test_bit(SCAN_HW_SCANNING, &local->scanning)))
422                 return ieee80211_scan_rx(rx->sdata, skb);
423
424         if (unlikely(test_bit(SCAN_SW_SCANNING, &local->scanning) &&
425                      (rx->flags & IEEE80211_RX_IN_SCAN))) {
426                 /* drop all the other packets during a software scan anyway */
427                 if (ieee80211_scan_rx(rx->sdata, skb) != RX_QUEUED)
428                         dev_kfree_skb(skb);
429                 return RX_QUEUED;
430         }
431
432         if (unlikely(rx->flags & IEEE80211_RX_IN_SCAN)) {
433                 /* scanning finished during invoking of handlers */
434                 I802_DEBUG_INC(local->rx_handlers_drop_passive_scan);
435                 return RX_DROP_UNUSABLE;
436         }
437
438         return RX_CONTINUE;
439 }
440
441
442 static int ieee80211_is_unicast_robust_mgmt_frame(struct sk_buff *skb)
443 {
444         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
445
446         if (skb->len < 24 || is_multicast_ether_addr(hdr->addr1))
447                 return 0;
448
449         return ieee80211_is_robust_mgmt_frame(hdr);
450 }
451
452
453 static int ieee80211_is_multicast_robust_mgmt_frame(struct sk_buff *skb)
454 {
455         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
456
457         if (skb->len < 24 || !is_multicast_ether_addr(hdr->addr1))
458                 return 0;
459
460         return ieee80211_is_robust_mgmt_frame(hdr);
461 }
462
463
464 /* Get the BIP key index from MMIE; return -1 if this is not a BIP frame */
465 static int ieee80211_get_mmie_keyidx(struct sk_buff *skb)
466 {
467         struct ieee80211_mgmt *hdr = (struct ieee80211_mgmt *) skb->data;
468         struct ieee80211_mmie *mmie;
469
470         if (skb->len < 24 + sizeof(*mmie) ||
471             !is_multicast_ether_addr(hdr->da))
472                 return -1;
473
474         if (!ieee80211_is_robust_mgmt_frame((struct ieee80211_hdr *) hdr))
475                 return -1; /* not a robust management frame */
476
477         mmie = (struct ieee80211_mmie *)
478                 (skb->data + skb->len - sizeof(*mmie));
479         if (mmie->element_id != WLAN_EID_MMIE ||
480             mmie->length != sizeof(*mmie) - 2)
481                 return -1;
482
483         return le16_to_cpu(mmie->key_id);
484 }
485
486
487 static ieee80211_rx_result
488 ieee80211_rx_mesh_check(struct ieee80211_rx_data *rx)
489 {
490         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
491         unsigned int hdrlen = ieee80211_hdrlen(hdr->frame_control);
492         char *dev_addr = rx->dev->dev_addr;
493
494         if (ieee80211_is_data(hdr->frame_control)) {
495                 if (is_multicast_ether_addr(hdr->addr1)) {
496                         if (ieee80211_has_tods(hdr->frame_control) ||
497                                 !ieee80211_has_fromds(hdr->frame_control))
498                                 return RX_DROP_MONITOR;
499                         if (memcmp(hdr->addr3, dev_addr, ETH_ALEN) == 0)
500                                 return RX_DROP_MONITOR;
501                 } else {
502                         if (!ieee80211_has_a4(hdr->frame_control))
503                                 return RX_DROP_MONITOR;
504                         if (memcmp(hdr->addr4, dev_addr, ETH_ALEN) == 0)
505                                 return RX_DROP_MONITOR;
506                 }
507         }
508
509         /* If there is not an established peer link and this is not a peer link
510          * establisment frame, beacon or probe, drop the frame.
511          */
512
513         if (!rx->sta || sta_plink_state(rx->sta) != PLINK_ESTAB) {
514                 struct ieee80211_mgmt *mgmt;
515
516                 if (!ieee80211_is_mgmt(hdr->frame_control))
517                         return RX_DROP_MONITOR;
518
519                 if (ieee80211_is_action(hdr->frame_control)) {
520                         mgmt = (struct ieee80211_mgmt *)hdr;
521                         if (mgmt->u.action.category != PLINK_CATEGORY)
522                                 return RX_DROP_MONITOR;
523                         return RX_CONTINUE;
524                 }
525
526                 if (ieee80211_is_probe_req(hdr->frame_control) ||
527                     ieee80211_is_probe_resp(hdr->frame_control) ||
528                     ieee80211_is_beacon(hdr->frame_control))
529                         return RX_CONTINUE;
530
531                 return RX_DROP_MONITOR;
532
533         }
534
535 #define msh_h_get(h, l) ((struct ieee80211s_hdr *) ((u8 *)h + l))
536
537         if (ieee80211_is_data(hdr->frame_control) &&
538             is_multicast_ether_addr(hdr->addr1) &&
539             mesh_rmc_check(hdr->addr3, msh_h_get(hdr, hdrlen), rx->sdata))
540                 return RX_DROP_MONITOR;
541 #undef msh_h_get
542
543         return RX_CONTINUE;
544 }
545
546
547 static ieee80211_rx_result debug_noinline
548 ieee80211_rx_h_check(struct ieee80211_rx_data *rx)
549 {
550         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
551
552         /* Drop duplicate 802.11 retransmissions (IEEE 802.11 Chap. 9.2.9) */
553         if (rx->sta && !is_multicast_ether_addr(hdr->addr1)) {
554                 if (unlikely(ieee80211_has_retry(hdr->frame_control) &&
555                              rx->sta->last_seq_ctrl[rx->queue] ==
556                              hdr->seq_ctrl)) {
557                         if (rx->flags & IEEE80211_RX_RA_MATCH) {
558                                 rx->local->dot11FrameDuplicateCount++;
559                                 rx->sta->num_duplicates++;
560                         }
561                         return RX_DROP_MONITOR;
562                 } else
563                         rx->sta->last_seq_ctrl[rx->queue] = hdr->seq_ctrl;
564         }
565
566         if (unlikely(rx->skb->len < 16)) {
567                 I802_DEBUG_INC(rx->local->rx_handlers_drop_short);
568                 return RX_DROP_MONITOR;
569         }
570
571         /* Drop disallowed frame classes based on STA auth/assoc state;
572          * IEEE 802.11, Chap 5.5.
573          *
574          * mac80211 filters only based on association state, i.e. it drops
575          * Class 3 frames from not associated stations. hostapd sends
576          * deauth/disassoc frames when needed. In addition, hostapd is
577          * responsible for filtering on both auth and assoc states.
578          */
579
580         if (ieee80211_vif_is_mesh(&rx->sdata->vif))
581                 return ieee80211_rx_mesh_check(rx);
582
583         if (unlikely((ieee80211_is_data(hdr->frame_control) ||
584                       ieee80211_is_pspoll(hdr->frame_control)) &&
585                      rx->sdata->vif.type != NL80211_IFTYPE_ADHOC &&
586                      (!rx->sta || !test_sta_flags(rx->sta, WLAN_STA_ASSOC)))) {
587                 if ((!ieee80211_has_fromds(hdr->frame_control) &&
588                      !ieee80211_has_tods(hdr->frame_control) &&
589                      ieee80211_is_data(hdr->frame_control)) ||
590                     !(rx->flags & IEEE80211_RX_RA_MATCH)) {
591                         /* Drop IBSS frames and frames for other hosts
592                          * silently. */
593                         return RX_DROP_MONITOR;
594                 }
595
596                 return RX_DROP_MONITOR;
597         }
598
599         return RX_CONTINUE;
600 }
601
602
603 static ieee80211_rx_result debug_noinline
604 ieee80211_rx_h_decrypt(struct ieee80211_rx_data *rx)
605 {
606         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
607         int keyidx;
608         int hdrlen;
609         ieee80211_rx_result result = RX_DROP_UNUSABLE;
610         struct ieee80211_key *stakey = NULL;
611         int mmie_keyidx = -1;
612
613         /*
614          * Key selection 101
615          *
616          * There are four types of keys:
617          *  - GTK (group keys)
618          *  - IGTK (group keys for management frames)
619          *  - PTK (pairwise keys)
620          *  - STK (station-to-station pairwise keys)
621          *
622          * When selecting a key, we have to distinguish between multicast
623          * (including broadcast) and unicast frames, the latter can only
624          * use PTKs and STKs while the former always use GTKs and IGTKs.
625          * Unless, of course, actual WEP keys ("pre-RSNA") are used, then
626          * unicast frames can also use key indices like GTKs. Hence, if we
627          * don't have a PTK/STK we check the key index for a WEP key.
628          *
629          * Note that in a regular BSS, multicast frames are sent by the
630          * AP only, associated stations unicast the frame to the AP first
631          * which then multicasts it on their behalf.
632          *
633          * There is also a slight problem in IBSS mode: GTKs are negotiated
634          * with each station, that is something we don't currently handle.
635          * The spec seems to expect that one negotiates the same key with
636          * every station but there's no such requirement; VLANs could be
637          * possible.
638          */
639
640         /*
641          * No point in finding a key and decrypting if the frame is neither
642          * addressed to us nor a multicast frame.
643          */
644         if (!(rx->flags & IEEE80211_RX_RA_MATCH))
645                 return RX_CONTINUE;
646
647         if (rx->sta)
648                 stakey = rcu_dereference(rx->sta->key);
649
650         if (!ieee80211_has_protected(hdr->frame_control))
651                 mmie_keyidx = ieee80211_get_mmie_keyidx(rx->skb);
652
653         if (!is_multicast_ether_addr(hdr->addr1) && stakey) {
654                 rx->key = stakey;
655                 /* Skip decryption if the frame is not protected. */
656                 if (!ieee80211_has_protected(hdr->frame_control))
657                         return RX_CONTINUE;
658         } else if (mmie_keyidx >= 0) {
659                 /* Broadcast/multicast robust management frame / BIP */
660                 if ((rx->status->flag & RX_FLAG_DECRYPTED) &&
661                     (rx->status->flag & RX_FLAG_IV_STRIPPED))
662                         return RX_CONTINUE;
663
664                 if (mmie_keyidx < NUM_DEFAULT_KEYS ||
665                     mmie_keyidx >= NUM_DEFAULT_KEYS + NUM_DEFAULT_MGMT_KEYS)
666                         return RX_DROP_MONITOR; /* unexpected BIP keyidx */
667                 rx->key = rcu_dereference(rx->sdata->keys[mmie_keyidx]);
668         } else if (!ieee80211_has_protected(hdr->frame_control)) {
669                 /*
670                  * The frame was not protected, so skip decryption. However, we
671                  * need to set rx->key if there is a key that could have been
672                  * used so that the frame may be dropped if encryption would
673                  * have been expected.
674                  */
675                 struct ieee80211_key *key = NULL;
676                 if (ieee80211_is_mgmt(hdr->frame_control) &&
677                     is_multicast_ether_addr(hdr->addr1) &&
678                     (key = rcu_dereference(rx->sdata->default_mgmt_key)))
679                         rx->key = key;
680                 else if ((key = rcu_dereference(rx->sdata->default_key)))
681                         rx->key = key;
682                 return RX_CONTINUE;
683         } else {
684                 /*
685                  * The device doesn't give us the IV so we won't be
686                  * able to look up the key. That's ok though, we
687                  * don't need to decrypt the frame, we just won't
688                  * be able to keep statistics accurate.
689                  * Except for key threshold notifications, should
690                  * we somehow allow the driver to tell us which key
691                  * the hardware used if this flag is set?
692                  */
693                 if ((rx->status->flag & RX_FLAG_DECRYPTED) &&
694                     (rx->status->flag & RX_FLAG_IV_STRIPPED))
695                         return RX_CONTINUE;
696
697                 hdrlen = ieee80211_hdrlen(hdr->frame_control);
698
699                 if (rx->skb->len < 8 + hdrlen)
700                         return RX_DROP_UNUSABLE; /* TODO: count this? */
701
702                 /*
703                  * no need to call ieee80211_wep_get_keyidx,
704                  * it verifies a bunch of things we've done already
705                  */
706                 keyidx = rx->skb->data[hdrlen + 3] >> 6;
707
708                 rx->key = rcu_dereference(rx->sdata->keys[keyidx]);
709
710                 /*
711                  * RSNA-protected unicast frames should always be sent with
712                  * pairwise or station-to-station keys, but for WEP we allow
713                  * using a key index as well.
714                  */
715                 if (rx->key && rx->key->conf.alg != ALG_WEP &&
716                     !is_multicast_ether_addr(hdr->addr1))
717                         rx->key = NULL;
718         }
719
720         if (rx->key) {
721                 rx->key->tx_rx_count++;
722                 /* TODO: add threshold stuff again */
723         } else {
724                 return RX_DROP_MONITOR;
725         }
726
727         /* Check for weak IVs if possible */
728         if (rx->sta && rx->key->conf.alg == ALG_WEP &&
729             ieee80211_is_data(hdr->frame_control) &&
730             (!(rx->status->flag & RX_FLAG_IV_STRIPPED) ||
731              !(rx->status->flag & RX_FLAG_DECRYPTED)) &&
732             ieee80211_wep_is_weak_iv(rx->skb, rx->key))
733                 rx->sta->wep_weak_iv_count++;
734
735         switch (rx->key->conf.alg) {
736         case ALG_WEP:
737                 result = ieee80211_crypto_wep_decrypt(rx);
738                 break;
739         case ALG_TKIP:
740                 result = ieee80211_crypto_tkip_decrypt(rx);
741                 break;
742         case ALG_CCMP:
743                 result = ieee80211_crypto_ccmp_decrypt(rx);
744                 break;
745         case ALG_AES_CMAC:
746                 result = ieee80211_crypto_aes_cmac_decrypt(rx);
747                 break;
748         }
749
750         /* either the frame has been decrypted or will be dropped */
751         rx->status->flag |= RX_FLAG_DECRYPTED;
752
753         return result;
754 }
755
756 static ieee80211_rx_result debug_noinline
757 ieee80211_rx_h_check_more_data(struct ieee80211_rx_data *rx)
758 {
759         struct ieee80211_local *local;
760         struct ieee80211_hdr *hdr;
761         struct sk_buff *skb;
762
763         local = rx->local;
764         skb = rx->skb;
765         hdr = (struct ieee80211_hdr *) skb->data;
766
767         if (!local->pspolling)
768                 return RX_CONTINUE;
769
770         if (!ieee80211_has_fromds(hdr->frame_control))
771                 /* this is not from AP */
772                 return RX_CONTINUE;
773
774         if (!ieee80211_is_data(hdr->frame_control))
775                 return RX_CONTINUE;
776
777         if (!ieee80211_has_moredata(hdr->frame_control)) {
778                 /* AP has no more frames buffered for us */
779                 local->pspolling = false;
780                 return RX_CONTINUE;
781         }
782
783         /* more data bit is set, let's request a new frame from the AP */
784         ieee80211_send_pspoll(local, rx->sdata);
785
786         return RX_CONTINUE;
787 }
788
789 static void ap_sta_ps_start(struct sta_info *sta)
790 {
791         struct ieee80211_sub_if_data *sdata = sta->sdata;
792         struct ieee80211_local *local = sdata->local;
793
794         atomic_inc(&sdata->bss->num_sta_ps);
795         set_sta_flags(sta, WLAN_STA_PS);
796         drv_sta_notify(local, &sdata->vif, STA_NOTIFY_SLEEP, &sta->sta);
797 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
798         printk(KERN_DEBUG "%s: STA %pM aid %d enters power save mode\n",
799                sdata->dev->name, sta->sta.addr, sta->sta.aid);
800 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
801 }
802
803 static int ap_sta_ps_end(struct sta_info *sta)
804 {
805         struct ieee80211_sub_if_data *sdata = sta->sdata;
806         struct ieee80211_local *local = sdata->local;
807         int sent, buffered;
808
809         atomic_dec(&sdata->bss->num_sta_ps);
810
811         clear_sta_flags(sta, WLAN_STA_PS);
812         drv_sta_notify(local, &sdata->vif, STA_NOTIFY_AWAKE, &sta->sta);
813
814         if (!skb_queue_empty(&sta->ps_tx_buf))
815                 sta_info_clear_tim_bit(sta);
816
817 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
818         printk(KERN_DEBUG "%s: STA %pM aid %d exits power save mode\n",
819                sdata->dev->name, sta->sta.addr, sta->sta.aid);
820 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
821
822         /* Send all buffered frames to the station */
823         sent = ieee80211_add_pending_skbs(local, &sta->tx_filtered);
824         buffered = ieee80211_add_pending_skbs(local, &sta->ps_tx_buf);
825         sent += buffered;
826         local->total_ps_buffered -= buffered;
827
828 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
829         printk(KERN_DEBUG "%s: STA %pM aid %d sending %d filtered/%d PS frames "
830                "since STA not sleeping anymore\n", sdata->dev->name,
831                sta->sta.addr, sta->sta.aid, sent - buffered, buffered);
832 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
833
834         return sent;
835 }
836
837 static ieee80211_rx_result debug_noinline
838 ieee80211_rx_h_sta_process(struct ieee80211_rx_data *rx)
839 {
840         struct sta_info *sta = rx->sta;
841         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
842
843         if (!sta)
844                 return RX_CONTINUE;
845
846         /*
847          * Update last_rx only for IBSS packets which are for the current
848          * BSSID to avoid keeping the current IBSS network alive in cases
849          * where other STAs start using different BSSID.
850          */
851         if (rx->sdata->vif.type == NL80211_IFTYPE_ADHOC) {
852                 u8 *bssid = ieee80211_get_bssid(hdr, rx->skb->len,
853                                                 NL80211_IFTYPE_ADHOC);
854                 if (compare_ether_addr(bssid, rx->sdata->u.ibss.bssid) == 0)
855                         sta->last_rx = jiffies;
856         } else if (!is_multicast_ether_addr(hdr->addr1)) {
857                 /*
858                  * Mesh beacons will update last_rx when if they are found to
859                  * match the current local configuration when processed.
860                  */
861                 sta->last_rx = jiffies;
862         }
863
864         if (!(rx->flags & IEEE80211_RX_RA_MATCH))
865                 return RX_CONTINUE;
866
867         if (rx->sdata->vif.type == NL80211_IFTYPE_STATION)
868                 ieee80211_sta_rx_notify(rx->sdata, hdr);
869
870         sta->rx_fragments++;
871         sta->rx_bytes += rx->skb->len;
872         sta->last_signal = rx->status->signal;
873         sta->last_qual = rx->status->qual;
874         sta->last_noise = rx->status->noise;
875
876         /*
877          * Change STA power saving mode only at the end of a frame
878          * exchange sequence.
879          */
880         if (!ieee80211_has_morefrags(hdr->frame_control) &&
881             (rx->sdata->vif.type == NL80211_IFTYPE_AP ||
882              rx->sdata->vif.type == NL80211_IFTYPE_AP_VLAN)) {
883                 if (test_sta_flags(sta, WLAN_STA_PS)) {
884                         /*
885                          * Ignore doze->wake transitions that are
886                          * indicated by non-data frames, the standard
887                          * is unclear here, but for example going to
888                          * PS mode and then scanning would cause a
889                          * doze->wake transition for the probe request,
890                          * and that is clearly undesirable.
891                          */
892                         if (ieee80211_is_data(hdr->frame_control) &&
893                             !ieee80211_has_pm(hdr->frame_control))
894                                 rx->sent_ps_buffered += ap_sta_ps_end(sta);
895                 } else {
896                         if (ieee80211_has_pm(hdr->frame_control))
897                                 ap_sta_ps_start(sta);
898                 }
899         }
900
901         /* Drop data::nullfunc frames silently, since they are used only to
902          * control station power saving mode. */
903         if (ieee80211_is_nullfunc(hdr->frame_control)) {
904                 I802_DEBUG_INC(rx->local->rx_handlers_drop_nullfunc);
905                 /* Update counter and free packet here to avoid counting this
906                  * as a dropped packed. */
907                 sta->rx_packets++;
908                 dev_kfree_skb(rx->skb);
909                 return RX_QUEUED;
910         }
911
912         return RX_CONTINUE;
913 } /* ieee80211_rx_h_sta_process */
914
915 static inline struct ieee80211_fragment_entry *
916 ieee80211_reassemble_add(struct ieee80211_sub_if_data *sdata,
917                          unsigned int frag, unsigned int seq, int rx_queue,
918                          struct sk_buff **skb)
919 {
920         struct ieee80211_fragment_entry *entry;
921         int idx;
922
923         idx = sdata->fragment_next;
924         entry = &sdata->fragments[sdata->fragment_next++];
925         if (sdata->fragment_next >= IEEE80211_FRAGMENT_MAX)
926                 sdata->fragment_next = 0;
927
928         if (!skb_queue_empty(&entry->skb_list)) {
929 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG
930                 struct ieee80211_hdr *hdr =
931                         (struct ieee80211_hdr *) entry->skb_list.next->data;
932                 printk(KERN_DEBUG "%s: RX reassembly removed oldest "
933                        "fragment entry (idx=%d age=%lu seq=%d last_frag=%d "
934                        "addr1=%pM addr2=%pM\n",
935                        sdata->dev->name, idx,
936                        jiffies - entry->first_frag_time, entry->seq,
937                        entry->last_frag, hdr->addr1, hdr->addr2);
938 #endif
939                 __skb_queue_purge(&entry->skb_list);
940         }
941
942         __skb_queue_tail(&entry->skb_list, *skb); /* no need for locking */
943         *skb = NULL;
944         entry->first_frag_time = jiffies;
945         entry->seq = seq;
946         entry->rx_queue = rx_queue;
947         entry->last_frag = frag;
948         entry->ccmp = 0;
949         entry->extra_len = 0;
950
951         return entry;
952 }
953
954 static inline struct ieee80211_fragment_entry *
955 ieee80211_reassemble_find(struct ieee80211_sub_if_data *sdata,
956                           unsigned int frag, unsigned int seq,
957                           int rx_queue, struct ieee80211_hdr *hdr)
958 {
959         struct ieee80211_fragment_entry *entry;
960         int i, idx;
961
962         idx = sdata->fragment_next;
963         for (i = 0; i < IEEE80211_FRAGMENT_MAX; i++) {
964                 struct ieee80211_hdr *f_hdr;
965
966                 idx--;
967                 if (idx < 0)
968                         idx = IEEE80211_FRAGMENT_MAX - 1;
969
970                 entry = &sdata->fragments[idx];
971                 if (skb_queue_empty(&entry->skb_list) || entry->seq != seq ||
972                     entry->rx_queue != rx_queue ||
973                     entry->last_frag + 1 != frag)
974                         continue;
975
976                 f_hdr = (struct ieee80211_hdr *)entry->skb_list.next->data;
977
978                 /*
979                  * Check ftype and addresses are equal, else check next fragment
980                  */
981                 if (((hdr->frame_control ^ f_hdr->frame_control) &
982                      cpu_to_le16(IEEE80211_FCTL_FTYPE)) ||
983                     compare_ether_addr(hdr->addr1, f_hdr->addr1) != 0 ||
984                     compare_ether_addr(hdr->addr2, f_hdr->addr2) != 0)
985                         continue;
986
987                 if (time_after(jiffies, entry->first_frag_time + 2 * HZ)) {
988                         __skb_queue_purge(&entry->skb_list);
989                         continue;
990                 }
991                 return entry;
992         }
993
994         return NULL;
995 }
996
997 static ieee80211_rx_result debug_noinline
998 ieee80211_rx_h_defragment(struct ieee80211_rx_data *rx)
999 {
1000         struct ieee80211_hdr *hdr;
1001         u16 sc;
1002         __le16 fc;
1003         unsigned int frag, seq;
1004         struct ieee80211_fragment_entry *entry;
1005         struct sk_buff *skb;
1006
1007         hdr = (struct ieee80211_hdr *)rx->skb->data;
1008         fc = hdr->frame_control;
1009         sc = le16_to_cpu(hdr->seq_ctrl);
1010         frag = sc & IEEE80211_SCTL_FRAG;
1011
1012         if (likely((!ieee80211_has_morefrags(fc) && frag == 0) ||
1013                    (rx->skb)->len < 24 ||
1014                    is_multicast_ether_addr(hdr->addr1))) {
1015                 /* not fragmented */
1016                 goto out;
1017         }
1018         I802_DEBUG_INC(rx->local->rx_handlers_fragments);
1019
1020         seq = (sc & IEEE80211_SCTL_SEQ) >> 4;
1021
1022         if (frag == 0) {
1023                 /* This is the first fragment of a new frame. */
1024                 entry = ieee80211_reassemble_add(rx->sdata, frag, seq,
1025                                                  rx->queue, &(rx->skb));
1026                 if (rx->key && rx->key->conf.alg == ALG_CCMP &&
1027                     ieee80211_has_protected(fc)) {
1028                         /* Store CCMP PN so that we can verify that the next
1029                          * fragment has a sequential PN value. */
1030                         entry->ccmp = 1;
1031                         memcpy(entry->last_pn,
1032                                rx->key->u.ccmp.rx_pn[rx->queue],
1033                                CCMP_PN_LEN);
1034                 }
1035                 return RX_QUEUED;
1036         }
1037
1038         /* This is a fragment for a frame that should already be pending in
1039          * fragment cache. Add this fragment to the end of the pending entry.
1040          */
1041         entry = ieee80211_reassemble_find(rx->sdata, frag, seq, rx->queue, hdr);
1042         if (!entry) {
1043                 I802_DEBUG_INC(rx->local->rx_handlers_drop_defrag);
1044                 return RX_DROP_MONITOR;
1045         }
1046
1047         /* Verify that MPDUs within one MSDU have sequential PN values.
1048          * (IEEE 802.11i, 8.3.3.4.5) */
1049         if (entry->ccmp) {
1050                 int i;
1051                 u8 pn[CCMP_PN_LEN], *rpn;
1052                 if (!rx->key || rx->key->conf.alg != ALG_CCMP)
1053                         return RX_DROP_UNUSABLE;
1054                 memcpy(pn, entry->last_pn, CCMP_PN_LEN);
1055                 for (i = CCMP_PN_LEN - 1; i >= 0; i--) {
1056                         pn[i]++;
1057                         if (pn[i])
1058                                 break;
1059                 }
1060                 rpn = rx->key->u.ccmp.rx_pn[rx->queue];
1061                 if (memcmp(pn, rpn, CCMP_PN_LEN))
1062                         return RX_DROP_UNUSABLE;
1063                 memcpy(entry->last_pn, pn, CCMP_PN_LEN);
1064         }
1065
1066         skb_pull(rx->skb, ieee80211_hdrlen(fc));
1067         __skb_queue_tail(&entry->skb_list, rx->skb);
1068         entry->last_frag = frag;
1069         entry->extra_len += rx->skb->len;
1070         if (ieee80211_has_morefrags(fc)) {
1071                 rx->skb = NULL;
1072                 return RX_QUEUED;
1073         }
1074
1075         rx->skb = __skb_dequeue(&entry->skb_list);
1076         if (skb_tailroom(rx->skb) < entry->extra_len) {
1077                 I802_DEBUG_INC(rx->local->rx_expand_skb_head2);
1078                 if (unlikely(pskb_expand_head(rx->skb, 0, entry->extra_len,
1079                                               GFP_ATOMIC))) {
1080                         I802_DEBUG_INC(rx->local->rx_handlers_drop_defrag);
1081                         __skb_queue_purge(&entry->skb_list);
1082                         return RX_DROP_UNUSABLE;
1083                 }
1084         }
1085         while ((skb = __skb_dequeue(&entry->skb_list))) {
1086                 memcpy(skb_put(rx->skb, skb->len), skb->data, skb->len);
1087                 dev_kfree_skb(skb);
1088         }
1089
1090         /* Complete frame has been reassembled - process it now */
1091         rx->flags |= IEEE80211_RX_FRAGMENTED;
1092
1093  out:
1094         if (rx->sta)
1095                 rx->sta->rx_packets++;
1096         if (is_multicast_ether_addr(hdr->addr1))
1097                 rx->local->dot11MulticastReceivedFrameCount++;
1098         else
1099                 ieee80211_led_rx(rx->local);
1100         return RX_CONTINUE;
1101 }
1102
1103 static ieee80211_rx_result debug_noinline
1104 ieee80211_rx_h_ps_poll(struct ieee80211_rx_data *rx)
1105 {
1106         struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(rx->dev);
1107         struct sk_buff *skb;
1108         int no_pending_pkts;
1109         __le16 fc = ((struct ieee80211_hdr *)rx->skb->data)->frame_control;
1110
1111         if (likely(!rx->sta || !ieee80211_is_pspoll(fc) ||
1112                    !(rx->flags & IEEE80211_RX_RA_MATCH)))
1113                 return RX_CONTINUE;
1114
1115         if ((sdata->vif.type != NL80211_IFTYPE_AP) &&
1116             (sdata->vif.type != NL80211_IFTYPE_AP_VLAN))
1117                 return RX_DROP_UNUSABLE;
1118
1119         skb = skb_dequeue(&rx->sta->tx_filtered);
1120         if (!skb) {
1121                 skb = skb_dequeue(&rx->sta->ps_tx_buf);
1122                 if (skb)
1123                         rx->local->total_ps_buffered--;
1124         }
1125         no_pending_pkts = skb_queue_empty(&rx->sta->tx_filtered) &&
1126                 skb_queue_empty(&rx->sta->ps_tx_buf);
1127
1128         if (skb) {
1129                 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
1130                 struct ieee80211_hdr *hdr =
1131                         (struct ieee80211_hdr *) skb->data;
1132
1133                 /*
1134                  * Tell TX path to send this frame even though the STA may
1135                  * still remain is PS mode after this frame exchange.
1136                  */
1137                 info->flags |= IEEE80211_TX_CTL_PSPOLL_RESPONSE;
1138
1139 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
1140                 printk(KERN_DEBUG "STA %pM aid %d: PS Poll (entries after %d)\n",
1141                        rx->sta->sta.addr, rx->sta->sta.aid,
1142                        skb_queue_len(&rx->sta->ps_tx_buf));
1143 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
1144
1145                 /* Use MoreData flag to indicate whether there are more
1146                  * buffered frames for this STA */
1147                 if (no_pending_pkts)
1148                         hdr->frame_control &= cpu_to_le16(~IEEE80211_FCTL_MOREDATA);
1149                 else
1150                         hdr->frame_control |= cpu_to_le16(IEEE80211_FCTL_MOREDATA);
1151
1152                 ieee80211_add_pending_skb(rx->local, skb);
1153
1154                 if (no_pending_pkts)
1155                         sta_info_clear_tim_bit(rx->sta);
1156 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
1157         } else if (!rx->sent_ps_buffered) {
1158                 /*
1159                  * FIXME: This can be the result of a race condition between
1160                  *        us expiring a frame and the station polling for it.
1161                  *        Should we send it a null-func frame indicating we
1162                  *        have nothing buffered for it?
1163                  */
1164                 printk(KERN_DEBUG "%s: STA %pM sent PS Poll even "
1165                        "though there are no buffered frames for it\n",
1166                        rx->dev->name, rx->sta->sta.addr);
1167 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
1168         }
1169
1170         /* Free PS Poll skb here instead of returning RX_DROP that would
1171          * count as an dropped frame. */
1172         dev_kfree_skb(rx->skb);
1173
1174         return RX_QUEUED;
1175 }
1176
1177 static ieee80211_rx_result debug_noinline
1178 ieee80211_rx_h_remove_qos_control(struct ieee80211_rx_data *rx)
1179 {
1180         u8 *data = rx->skb->data;
1181         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)data;
1182
1183         if (!ieee80211_is_data_qos(hdr->frame_control))
1184                 return RX_CONTINUE;
1185
1186         /* remove the qos control field, update frame type and meta-data */
1187         memmove(data + IEEE80211_QOS_CTL_LEN, data,
1188                 ieee80211_hdrlen(hdr->frame_control) - IEEE80211_QOS_CTL_LEN);
1189         hdr = (struct ieee80211_hdr *)skb_pull(rx->skb, IEEE80211_QOS_CTL_LEN);
1190         /* change frame type to non QOS */
1191         hdr->frame_control &= ~cpu_to_le16(IEEE80211_STYPE_QOS_DATA);
1192
1193         return RX_CONTINUE;
1194 }
1195
1196 static int
1197 ieee80211_802_1x_port_control(struct ieee80211_rx_data *rx)
1198 {
1199         if (unlikely(!rx->sta ||
1200             !test_sta_flags(rx->sta, WLAN_STA_AUTHORIZED)))
1201                 return -EACCES;
1202
1203         return 0;
1204 }
1205
1206 static int
1207 ieee80211_drop_unencrypted(struct ieee80211_rx_data *rx, __le16 fc)
1208 {
1209         /*
1210          * Pass through unencrypted frames if the hardware has
1211          * decrypted them already.
1212          */
1213         if (rx->status->flag & RX_FLAG_DECRYPTED)
1214                 return 0;
1215
1216         /* Drop unencrypted frames if key is set. */
1217         if (unlikely(!ieee80211_has_protected(fc) &&
1218                      !ieee80211_is_nullfunc(fc) &&
1219                      ieee80211_is_data(fc) &&
1220                      (rx->key || rx->sdata->drop_unencrypted)))
1221                 return -EACCES;
1222         if (rx->sta && test_sta_flags(rx->sta, WLAN_STA_MFP)) {
1223                 if (unlikely(ieee80211_is_unicast_robust_mgmt_frame(rx->skb) &&
1224                              rx->key))
1225                         return -EACCES;
1226                 /* BIP does not use Protected field, so need to check MMIE */
1227                 if (unlikely(ieee80211_is_multicast_robust_mgmt_frame(rx->skb)
1228                              && ieee80211_get_mmie_keyidx(rx->skb) < 0 &&
1229                              rx->key))
1230                         return -EACCES;
1231                 /*
1232                  * When using MFP, Action frames are not allowed prior to
1233                  * having configured keys.
1234                  */
1235                 if (unlikely(ieee80211_is_action(fc) && !rx->key &&
1236                              ieee80211_is_robust_mgmt_frame(
1237                                      (struct ieee80211_hdr *) rx->skb->data)))
1238                         return -EACCES;
1239         }
1240
1241         return 0;
1242 }
1243
1244 static int
1245 __ieee80211_data_to_8023(struct ieee80211_rx_data *rx)
1246 {
1247         struct net_device *dev = rx->dev;
1248         struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
1249
1250         return ieee80211_data_to_8023(rx->skb, dev->dev_addr, sdata->vif.type);
1251 }
1252
1253 /*
1254  * requires that rx->skb is a frame with ethernet header
1255  */
1256 static bool ieee80211_frame_allowed(struct ieee80211_rx_data *rx, __le16 fc)
1257 {
1258         static const u8 pae_group_addr[ETH_ALEN] __aligned(2)
1259                 = { 0x01, 0x80, 0xC2, 0x00, 0x00, 0x03 };
1260         struct ethhdr *ehdr = (struct ethhdr *) rx->skb->data;
1261
1262         /*
1263          * Allow EAPOL frames to us/the PAE group address regardless
1264          * of whether the frame was encrypted or not.
1265          */
1266         if (ehdr->h_proto == htons(ETH_P_PAE) &&
1267             (compare_ether_addr(ehdr->h_dest, rx->dev->dev_addr) == 0 ||
1268              compare_ether_addr(ehdr->h_dest, pae_group_addr) == 0))
1269                 return true;
1270
1271         if (ieee80211_802_1x_port_control(rx) ||
1272             ieee80211_drop_unencrypted(rx, fc))
1273                 return false;
1274
1275         return true;
1276 }
1277
1278 /*
1279  * requires that rx->skb is a frame with ethernet header
1280  */
1281 static void
1282 ieee80211_deliver_skb(struct ieee80211_rx_data *rx)
1283 {
1284         struct net_device *dev = rx->dev;
1285         struct ieee80211_local *local = rx->local;
1286         struct sk_buff *skb, *xmit_skb;
1287         struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
1288         struct ethhdr *ehdr = (struct ethhdr *) rx->skb->data;
1289         struct sta_info *dsta;
1290
1291         skb = rx->skb;
1292         xmit_skb = NULL;
1293
1294         if ((sdata->vif.type == NL80211_IFTYPE_AP ||
1295              sdata->vif.type == NL80211_IFTYPE_AP_VLAN) &&
1296             !(sdata->flags & IEEE80211_SDATA_DONT_BRIDGE_PACKETS) &&
1297             (rx->flags & IEEE80211_RX_RA_MATCH)) {
1298                 if (is_multicast_ether_addr(ehdr->h_dest)) {
1299                         /*
1300                          * send multicast frames both to higher layers in
1301                          * local net stack and back to the wireless medium
1302                          */
1303                         xmit_skb = skb_copy(skb, GFP_ATOMIC);
1304                         if (!xmit_skb && net_ratelimit())
1305                                 printk(KERN_DEBUG "%s: failed to clone "
1306                                        "multicast frame\n", dev->name);
1307                 } else {
1308                         dsta = sta_info_get(local, skb->data);
1309                         if (dsta && dsta->sdata->dev == dev) {
1310                                 /*
1311                                  * The destination station is associated to
1312                                  * this AP (in this VLAN), so send the frame
1313                                  * directly to it and do not pass it to local
1314                                  * net stack.
1315                                  */
1316                                 xmit_skb = skb;
1317                                 skb = NULL;
1318                         }
1319                 }
1320         }
1321
1322         if (skb) {
1323                 int align __maybe_unused;
1324
1325 #if defined(CONFIG_MAC80211_DEBUG_PACKET_ALIGNMENT) || !defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS)
1326                 /*
1327                  * 'align' will only take the values 0 or 2 here
1328                  * since all frames are required to be aligned
1329                  * to 2-byte boundaries when being passed to
1330                  * mac80211. That also explains the __skb_push()
1331                  * below.
1332                  */
1333                 align = ((unsigned long)(skb->data + sizeof(struct ethhdr))) & 3;
1334                 if (align) {
1335                         if (WARN_ON(skb_headroom(skb) < 3)) {
1336                                 dev_kfree_skb(skb);
1337                                 skb = NULL;
1338                         } else {
1339                                 u8 *data = skb->data;
1340                                 size_t len = skb->len;
1341                                 u8 *new = __skb_push(skb, align);
1342                                 memmove(new, data, len);
1343                                 __skb_trim(skb, len);
1344                         }
1345                 }
1346 #endif
1347
1348                 if (skb) {
1349                         /* deliver to local stack */
1350                         skb->protocol = eth_type_trans(skb, dev);
1351                         memset(skb->cb, 0, sizeof(skb->cb));
1352                         netif_rx(skb);
1353                 }
1354         }
1355
1356         if (xmit_skb) {
1357                 /* send to wireless media */
1358                 xmit_skb->protocol = htons(ETH_P_802_3);
1359                 skb_reset_network_header(xmit_skb);
1360                 skb_reset_mac_header(xmit_skb);
1361                 dev_queue_xmit(xmit_skb);
1362         }
1363 }
1364
1365 static ieee80211_rx_result debug_noinline
1366 ieee80211_rx_h_amsdu(struct ieee80211_rx_data *rx)
1367 {
1368         struct net_device *dev = rx->dev;
1369         struct ieee80211_local *local = rx->local;
1370         u16 ethertype;
1371         u8 *payload;
1372         struct sk_buff *skb = rx->skb, *frame = NULL;
1373         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
1374         __le16 fc = hdr->frame_control;
1375         const struct ethhdr *eth;
1376         int remaining, err;
1377         u8 dst[ETH_ALEN];
1378         u8 src[ETH_ALEN];
1379
1380         if (unlikely(!ieee80211_is_data(fc)))
1381                 return RX_CONTINUE;
1382
1383         if (unlikely(!ieee80211_is_data_present(fc)))
1384                 return RX_DROP_MONITOR;
1385
1386         if (!(rx->flags & IEEE80211_RX_AMSDU))
1387                 return RX_CONTINUE;
1388
1389         err = __ieee80211_data_to_8023(rx);
1390         if (unlikely(err))
1391                 return RX_DROP_UNUSABLE;
1392
1393         skb->dev = dev;
1394
1395         dev->stats.rx_packets++;
1396         dev->stats.rx_bytes += skb->len;
1397
1398         /* skip the wrapping header */
1399         eth = (struct ethhdr *) skb_pull(skb, sizeof(struct ethhdr));
1400         if (!eth)
1401                 return RX_DROP_UNUSABLE;
1402
1403         while (skb != frame) {
1404                 u8 padding;
1405                 __be16 len = eth->h_proto;
1406                 unsigned int subframe_len = sizeof(struct ethhdr) + ntohs(len);
1407
1408                 remaining = skb->len;
1409                 memcpy(dst, eth->h_dest, ETH_ALEN);
1410                 memcpy(src, eth->h_source, ETH_ALEN);
1411
1412                 padding = ((4 - subframe_len) & 0x3);
1413                 /* the last MSDU has no padding */
1414                 if (subframe_len > remaining)
1415                         return RX_DROP_UNUSABLE;
1416
1417                 skb_pull(skb, sizeof(struct ethhdr));
1418                 /* if last subframe reuse skb */
1419                 if (remaining <= subframe_len + padding)
1420                         frame = skb;
1421                 else {
1422                         /*
1423                          * Allocate and reserve two bytes more for payload
1424                          * alignment since sizeof(struct ethhdr) is 14.
1425                          */
1426                         frame = dev_alloc_skb(
1427                                 ALIGN(local->hw.extra_tx_headroom, 4) +
1428                                 subframe_len + 2);
1429
1430                         if (frame == NULL)
1431                                 return RX_DROP_UNUSABLE;
1432
1433                         skb_reserve(frame,
1434                                     ALIGN(local->hw.extra_tx_headroom, 4) +
1435                                     sizeof(struct ethhdr) + 2);
1436                         memcpy(skb_put(frame, ntohs(len)), skb->data,
1437                                 ntohs(len));
1438
1439                         eth = (struct ethhdr *) skb_pull(skb, ntohs(len) +
1440                                                         padding);
1441                         if (!eth) {
1442                                 dev_kfree_skb(frame);
1443                                 return RX_DROP_UNUSABLE;
1444                         }
1445                 }
1446
1447                 skb_reset_network_header(frame);
1448                 frame->dev = dev;
1449                 frame->priority = skb->priority;
1450                 rx->skb = frame;
1451
1452                 payload = frame->data;
1453                 ethertype = (payload[6] << 8) | payload[7];
1454
1455                 if (likely((compare_ether_addr(payload, rfc1042_header) == 0 &&
1456                             ethertype != ETH_P_AARP && ethertype != ETH_P_IPX) ||
1457                            compare_ether_addr(payload,
1458                                               bridge_tunnel_header) == 0)) {
1459                         /* remove RFC1042 or Bridge-Tunnel
1460                          * encapsulation and replace EtherType */
1461                         skb_pull(frame, 6);
1462                         memcpy(skb_push(frame, ETH_ALEN), src, ETH_ALEN);
1463                         memcpy(skb_push(frame, ETH_ALEN), dst, ETH_ALEN);
1464                 } else {
1465                         memcpy(skb_push(frame, sizeof(__be16)),
1466                                &len, sizeof(__be16));
1467                         memcpy(skb_push(frame, ETH_ALEN), src, ETH_ALEN);
1468                         memcpy(skb_push(frame, ETH_ALEN), dst, ETH_ALEN);
1469                 }
1470
1471                 if (!ieee80211_frame_allowed(rx, fc)) {
1472                         if (skb == frame) /* last frame */
1473                                 return RX_DROP_UNUSABLE;
1474                         dev_kfree_skb(frame);
1475                         continue;
1476                 }
1477
1478                 ieee80211_deliver_skb(rx);
1479         }
1480
1481         return RX_QUEUED;
1482 }
1483
1484 #ifdef CONFIG_MAC80211_MESH
1485 static ieee80211_rx_result
1486 ieee80211_rx_h_mesh_fwding(struct ieee80211_rx_data *rx)
1487 {
1488         struct ieee80211_hdr *hdr;
1489         struct ieee80211s_hdr *mesh_hdr;
1490         unsigned int hdrlen;
1491         struct sk_buff *skb = rx->skb, *fwd_skb;
1492         struct ieee80211_local *local = rx->local;
1493         struct ieee80211_sub_if_data *sdata;
1494
1495         hdr = (struct ieee80211_hdr *) skb->data;
1496         hdrlen = ieee80211_hdrlen(hdr->frame_control);
1497         mesh_hdr = (struct ieee80211s_hdr *) (skb->data + hdrlen);
1498         sdata = IEEE80211_DEV_TO_SUB_IF(rx->dev);
1499
1500         if (!ieee80211_is_data(hdr->frame_control))
1501                 return RX_CONTINUE;
1502
1503         if (!mesh_hdr->ttl)
1504                 /* illegal frame */
1505                 return RX_DROP_MONITOR;
1506
1507         if (!is_multicast_ether_addr(hdr->addr1) &&
1508                         (mesh_hdr->flags & MESH_FLAGS_AE_A5_A6)) {
1509                 struct mesh_path *mppath;
1510
1511                 rcu_read_lock();
1512                 mppath = mpp_path_lookup(mesh_hdr->eaddr2, sdata);
1513                 if (!mppath) {
1514                         mpp_path_add(mesh_hdr->eaddr2, hdr->addr4, sdata);
1515                 } else {
1516                         spin_lock_bh(&mppath->state_lock);
1517                         mppath->exp_time = jiffies;
1518                         if (compare_ether_addr(mppath->mpp, hdr->addr4) != 0)
1519                                 memcpy(mppath->mpp, hdr->addr4, ETH_ALEN);
1520                         spin_unlock_bh(&mppath->state_lock);
1521                 }
1522                 rcu_read_unlock();
1523         }
1524
1525         /* Frame has reached destination.  Don't forward */
1526         if (!is_multicast_ether_addr(hdr->addr1) &&
1527                         compare_ether_addr(rx->dev->dev_addr, hdr->addr3) == 0)
1528                 return RX_CONTINUE;
1529
1530         mesh_hdr->ttl--;
1531
1532         if (rx->flags & IEEE80211_RX_RA_MATCH) {
1533                 if (!mesh_hdr->ttl)
1534                         IEEE80211_IFSTA_MESH_CTR_INC(&rx->sdata->u.mesh,
1535                                                      dropped_frames_ttl);
1536                 else {
1537                         struct ieee80211_hdr *fwd_hdr;
1538                         struct ieee80211_tx_info *info;
1539
1540                         fwd_skb = skb_copy(skb, GFP_ATOMIC);
1541
1542                         if (!fwd_skb && net_ratelimit())
1543                                 printk(KERN_DEBUG "%s: failed to clone mesh frame\n",
1544                                                    rx->dev->name);
1545
1546                         fwd_hdr =  (struct ieee80211_hdr *) fwd_skb->data;
1547                         memcpy(fwd_hdr->addr2, rx->dev->dev_addr, ETH_ALEN);
1548                         info = IEEE80211_SKB_CB(fwd_skb);
1549                         memset(info, 0, sizeof(*info));
1550                         info->flags |= IEEE80211_TX_INTFL_NEED_TXPROCESSING;
1551                         info->control.vif = &rx->sdata->vif;
1552                         ieee80211_select_queue(local, fwd_skb);
1553                         if (is_multicast_ether_addr(fwd_hdr->addr1))
1554                                 IEEE80211_IFSTA_MESH_CTR_INC(&sdata->u.mesh,
1555                                                                 fwded_mcast);
1556                         else {
1557                                 int err;
1558                                 /*
1559                                  * Save TA to addr1 to send TA a path error if a
1560                                  * suitable next hop is not found
1561                                  */
1562                                 memcpy(fwd_hdr->addr1, fwd_hdr->addr2,
1563                                                 ETH_ALEN);
1564                                 err = mesh_nexthop_lookup(fwd_skb, sdata);
1565                                 /* Failed to immediately resolve next hop:
1566                                  * fwded frame was dropped or will be added
1567                                  * later to the pending skb queue.  */
1568                                 if (err)
1569                                         return RX_DROP_MONITOR;
1570
1571                                 IEEE80211_IFSTA_MESH_CTR_INC(&sdata->u.mesh,
1572                                                                 fwded_unicast);
1573                         }
1574                         IEEE80211_IFSTA_MESH_CTR_INC(&sdata->u.mesh,
1575                                                      fwded_frames);
1576                         ieee80211_add_pending_skb(local, fwd_skb);
1577                 }
1578         }
1579
1580         if (is_multicast_ether_addr(hdr->addr1) ||
1581             rx->dev->flags & IFF_PROMISC)
1582                 return RX_CONTINUE;
1583         else
1584                 return RX_DROP_MONITOR;
1585 }
1586 #endif
1587
1588 static ieee80211_rx_result debug_noinline
1589 ieee80211_rx_h_data(struct ieee80211_rx_data *rx)
1590 {
1591         struct net_device *dev = rx->dev;
1592         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
1593         __le16 fc = hdr->frame_control;
1594         int err;
1595
1596         if (unlikely(!ieee80211_is_data(hdr->frame_control)))
1597                 return RX_CONTINUE;
1598
1599         if (unlikely(!ieee80211_is_data_present(hdr->frame_control)))
1600                 return RX_DROP_MONITOR;
1601
1602         err = __ieee80211_data_to_8023(rx);
1603         if (unlikely(err))
1604                 return RX_DROP_UNUSABLE;
1605
1606         if (!ieee80211_frame_allowed(rx, fc))
1607                 return RX_DROP_MONITOR;
1608
1609         rx->skb->dev = dev;
1610
1611         dev->stats.rx_packets++;
1612         dev->stats.rx_bytes += rx->skb->len;
1613
1614         ieee80211_deliver_skb(rx);
1615
1616         return RX_QUEUED;
1617 }
1618
1619 static ieee80211_rx_result debug_noinline
1620 ieee80211_rx_h_ctrl(struct ieee80211_rx_data *rx)
1621 {
1622         struct ieee80211_local *local = rx->local;
1623         struct ieee80211_hw *hw = &local->hw;
1624         struct sk_buff *skb = rx->skb;
1625         struct ieee80211_bar *bar = (struct ieee80211_bar *)skb->data;
1626         struct tid_ampdu_rx *tid_agg_rx;
1627         u16 start_seq_num;
1628         u16 tid;
1629
1630         if (likely(!ieee80211_is_ctl(bar->frame_control)))
1631                 return RX_CONTINUE;
1632
1633         if (ieee80211_is_back_req(bar->frame_control)) {
1634                 if (!rx->sta)
1635                         return RX_CONTINUE;
1636                 tid = le16_to_cpu(bar->control) >> 12;
1637                 if (rx->sta->ampdu_mlme.tid_state_rx[tid]
1638                                         != HT_AGG_STATE_OPERATIONAL)
1639                         return RX_CONTINUE;
1640                 tid_agg_rx = rx->sta->ampdu_mlme.tid_rx[tid];
1641
1642                 start_seq_num = le16_to_cpu(bar->start_seq_num) >> 4;
1643
1644                 /* reset session timer */
1645                 if (tid_agg_rx->timeout)
1646                         mod_timer(&tid_agg_rx->session_timer,
1647                                   TU_TO_EXP_TIME(tid_agg_rx->timeout));
1648
1649                 /* manage reordering buffer according to requested */
1650                 /* sequence number */
1651                 rcu_read_lock();
1652                 ieee80211_sta_manage_reorder_buf(hw, tid_agg_rx, NULL,
1653                                                  start_seq_num, 1);
1654                 rcu_read_unlock();
1655                 return RX_DROP_UNUSABLE;
1656         }
1657
1658         return RX_CONTINUE;
1659 }
1660
1661 static void ieee80211_process_sa_query_req(struct ieee80211_sub_if_data *sdata,
1662                                            struct ieee80211_mgmt *mgmt,
1663                                            size_t len)
1664 {
1665         struct ieee80211_local *local = sdata->local;
1666         struct sk_buff *skb;
1667         struct ieee80211_mgmt *resp;
1668
1669         if (compare_ether_addr(mgmt->da, sdata->dev->dev_addr) != 0) {
1670                 /* Not to own unicast address */
1671                 return;
1672         }
1673
1674         if (compare_ether_addr(mgmt->sa, sdata->u.mgd.bssid) != 0 ||
1675             compare_ether_addr(mgmt->bssid, sdata->u.mgd.bssid) != 0) {
1676                 /* Not from the current AP or not associated yet. */
1677                 return;
1678         }
1679
1680         if (len < 24 + 1 + sizeof(resp->u.action.u.sa_query)) {
1681                 /* Too short SA Query request frame */
1682                 return;
1683         }
1684
1685         skb = dev_alloc_skb(sizeof(*resp) + local->hw.extra_tx_headroom);
1686         if (skb == NULL)
1687                 return;
1688
1689         skb_reserve(skb, local->hw.extra_tx_headroom);
1690         resp = (struct ieee80211_mgmt *) skb_put(skb, 24);
1691         memset(resp, 0, 24);
1692         memcpy(resp->da, mgmt->sa, ETH_ALEN);
1693         memcpy(resp->sa, sdata->dev->dev_addr, ETH_ALEN);
1694         memcpy(resp->bssid, sdata->u.mgd.bssid, ETH_ALEN);
1695         resp->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
1696                                           IEEE80211_STYPE_ACTION);
1697         skb_put(skb, 1 + sizeof(resp->u.action.u.sa_query));
1698         resp->u.action.category = WLAN_CATEGORY_SA_QUERY;
1699         resp->u.action.u.sa_query.action = WLAN_ACTION_SA_QUERY_RESPONSE;
1700         memcpy(resp->u.action.u.sa_query.trans_id,
1701                mgmt->u.action.u.sa_query.trans_id,
1702                WLAN_SA_QUERY_TR_ID_LEN);
1703
1704         ieee80211_tx_skb(sdata, skb, 1);
1705 }
1706
1707 static ieee80211_rx_result debug_noinline
1708 ieee80211_rx_h_action(struct ieee80211_rx_data *rx)
1709 {
1710         struct ieee80211_local *local = rx->local;
1711         struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(rx->dev);
1712         struct ieee80211_mgmt *mgmt = (struct ieee80211_mgmt *) rx->skb->data;
1713         int len = rx->skb->len;
1714
1715         if (!ieee80211_is_action(mgmt->frame_control))
1716                 return RX_CONTINUE;
1717
1718         if (!rx->sta)
1719                 return RX_DROP_MONITOR;
1720
1721         if (!(rx->flags & IEEE80211_RX_RA_MATCH))
1722                 return RX_DROP_MONITOR;
1723
1724         if (ieee80211_drop_unencrypted(rx, mgmt->frame_control))
1725                 return RX_DROP_MONITOR;
1726
1727         /* all categories we currently handle have action_code */
1728         if (len < IEEE80211_MIN_ACTION_SIZE + 1)
1729                 return RX_DROP_MONITOR;
1730
1731         switch (mgmt->u.action.category) {
1732         case WLAN_CATEGORY_BACK:
1733                 /*
1734                  * The aggregation code is not prepared to handle
1735                  * anything but STA/AP due to the BSSID handling;
1736                  * IBSS could work in the code but isn't supported
1737                  * by drivers or the standard.
1738                  */
1739                 if (sdata->vif.type != NL80211_IFTYPE_STATION &&
1740                     sdata->vif.type != NL80211_IFTYPE_AP_VLAN &&
1741                     sdata->vif.type != NL80211_IFTYPE_AP)
1742                         return RX_DROP_MONITOR;
1743
1744                 switch (mgmt->u.action.u.addba_req.action_code) {
1745                 case WLAN_ACTION_ADDBA_REQ:
1746                         if (len < (IEEE80211_MIN_ACTION_SIZE +
1747                                    sizeof(mgmt->u.action.u.addba_req)))
1748                                 return RX_DROP_MONITOR;
1749                         ieee80211_process_addba_request(local, rx->sta, mgmt, len);
1750                         break;
1751                 case WLAN_ACTION_ADDBA_RESP:
1752                         if (len < (IEEE80211_MIN_ACTION_SIZE +
1753                                    sizeof(mgmt->u.action.u.addba_resp)))
1754                                 return RX_DROP_MONITOR;
1755                         ieee80211_process_addba_resp(local, rx->sta, mgmt, len);
1756                         break;
1757                 case WLAN_ACTION_DELBA:
1758                         if (len < (IEEE80211_MIN_ACTION_SIZE +
1759                                    sizeof(mgmt->u.action.u.delba)))
1760                                 return RX_DROP_MONITOR;
1761                         ieee80211_process_delba(sdata, rx->sta, mgmt, len);
1762                         break;
1763                 }
1764                 break;
1765         case WLAN_CATEGORY_SPECTRUM_MGMT:
1766                 if (local->hw.conf.channel->band != IEEE80211_BAND_5GHZ)
1767                         return RX_DROP_MONITOR;
1768
1769                 if (sdata->vif.type != NL80211_IFTYPE_STATION)
1770                         return RX_DROP_MONITOR;
1771
1772                 switch (mgmt->u.action.u.measurement.action_code) {
1773                 case WLAN_ACTION_SPCT_MSR_REQ:
1774                         if (len < (IEEE80211_MIN_ACTION_SIZE +
1775                                    sizeof(mgmt->u.action.u.measurement)))
1776                                 return RX_DROP_MONITOR;
1777                         ieee80211_process_measurement_req(sdata, mgmt, len);
1778                         break;
1779                 case WLAN_ACTION_SPCT_CHL_SWITCH:
1780                         if (len < (IEEE80211_MIN_ACTION_SIZE +
1781                                    sizeof(mgmt->u.action.u.chan_switch)))
1782                                 return RX_DROP_MONITOR;
1783
1784                         if (sdata->vif.type != NL80211_IFTYPE_STATION)
1785                                 return RX_DROP_MONITOR;
1786
1787                         if (memcmp(mgmt->bssid, sdata->u.mgd.bssid, ETH_ALEN))
1788                                 return RX_DROP_MONITOR;
1789
1790                         return ieee80211_sta_rx_mgmt(sdata, rx->skb);
1791                 }
1792                 break;
1793         case WLAN_CATEGORY_SA_QUERY:
1794                 if (len < (IEEE80211_MIN_ACTION_SIZE +
1795                            sizeof(mgmt->u.action.u.sa_query)))
1796                         return RX_DROP_MONITOR;
1797                 switch (mgmt->u.action.u.sa_query.action) {
1798                 case WLAN_ACTION_SA_QUERY_REQUEST:
1799                         if (sdata->vif.type != NL80211_IFTYPE_STATION)
1800                                 return RX_DROP_MONITOR;
1801                         ieee80211_process_sa_query_req(sdata, mgmt, len);
1802                         break;
1803                 case WLAN_ACTION_SA_QUERY_RESPONSE:
1804                         /*
1805                          * SA Query response is currently only used in AP mode
1806                          * and it is processed in user space.
1807                          */
1808                         return RX_CONTINUE;
1809                 }
1810                 break;
1811         default:
1812                 return RX_CONTINUE;
1813         }
1814
1815         rx->sta->rx_packets++;
1816         dev_kfree_skb(rx->skb);
1817         return RX_QUEUED;
1818 }
1819
1820 static ieee80211_rx_result debug_noinline
1821 ieee80211_rx_h_mgmt(struct ieee80211_rx_data *rx)
1822 {
1823         struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(rx->dev);
1824         struct ieee80211_mgmt *mgmt = (struct ieee80211_mgmt *) rx->skb->data;
1825
1826         if (!(rx->flags & IEEE80211_RX_RA_MATCH))
1827                 return RX_DROP_MONITOR;
1828
1829         if (ieee80211_drop_unencrypted(rx, mgmt->frame_control))
1830                 return RX_DROP_MONITOR;
1831
1832         if (ieee80211_vif_is_mesh(&sdata->vif))
1833                 return ieee80211_mesh_rx_mgmt(sdata, rx->skb);
1834
1835         if (sdata->vif.type == NL80211_IFTYPE_ADHOC)
1836                 return ieee80211_ibss_rx_mgmt(sdata, rx->skb);
1837
1838         if (sdata->vif.type == NL80211_IFTYPE_STATION)
1839                 return ieee80211_sta_rx_mgmt(sdata, rx->skb);
1840
1841         return RX_DROP_MONITOR;
1842 }
1843
1844 static void ieee80211_rx_michael_mic_report(struct ieee80211_hdr *hdr,
1845                                             struct ieee80211_rx_data *rx)
1846 {
1847         int keyidx;
1848         unsigned int hdrlen;
1849
1850         hdrlen = ieee80211_hdrlen(hdr->frame_control);
1851         if (rx->skb->len >= hdrlen + 4)
1852                 keyidx = rx->skb->data[hdrlen + 3] >> 6;
1853         else
1854                 keyidx = -1;
1855
1856         if (!rx->sta) {
1857                 /*
1858                  * Some hardware seem to generate incorrect Michael MIC
1859                  * reports; ignore them to avoid triggering countermeasures.
1860                  */
1861                 goto ignore;
1862         }
1863
1864         if (!ieee80211_has_protected(hdr->frame_control))
1865                 goto ignore;
1866
1867         if (rx->sdata->vif.type == NL80211_IFTYPE_AP && keyidx) {
1868                 /*
1869                  * APs with pairwise keys should never receive Michael MIC
1870                  * errors for non-zero keyidx because these are reserved for
1871                  * group keys and only the AP is sending real multicast
1872                  * frames in the BSS.
1873                  */
1874                 goto ignore;
1875         }
1876
1877         if (!ieee80211_is_data(hdr->frame_control) &&
1878             !ieee80211_is_auth(hdr->frame_control))
1879                 goto ignore;
1880
1881         mac80211_ev_michael_mic_failure(rx->sdata, keyidx, hdr, NULL,
1882                                         GFP_ATOMIC);
1883  ignore:
1884         dev_kfree_skb(rx->skb);
1885         rx->skb = NULL;
1886 }
1887
1888 /* TODO: use IEEE80211_RX_FRAGMENTED */
1889 static void ieee80211_rx_cooked_monitor(struct ieee80211_rx_data *rx)
1890 {
1891         struct ieee80211_sub_if_data *sdata;
1892         struct ieee80211_local *local = rx->local;
1893         struct ieee80211_rtap_hdr {
1894                 struct ieee80211_radiotap_header hdr;
1895                 u8 flags;
1896                 u8 rate;
1897                 __le16 chan_freq;
1898                 __le16 chan_flags;
1899         } __attribute__ ((packed)) *rthdr;
1900         struct sk_buff *skb = rx->skb, *skb2;
1901         struct net_device *prev_dev = NULL;
1902         struct ieee80211_rx_status *status = rx->status;
1903
1904         if (rx->flags & IEEE80211_RX_CMNTR_REPORTED)
1905                 goto out_free_skb;
1906
1907         if (skb_headroom(skb) < sizeof(*rthdr) &&
1908             pskb_expand_head(skb, sizeof(*rthdr), 0, GFP_ATOMIC))
1909                 goto out_free_skb;
1910
1911         rthdr = (void *)skb_push(skb, sizeof(*rthdr));
1912         memset(rthdr, 0, sizeof(*rthdr));
1913         rthdr->hdr.it_len = cpu_to_le16(sizeof(*rthdr));
1914         rthdr->hdr.it_present =
1915                 cpu_to_le32((1 << IEEE80211_RADIOTAP_FLAGS) |
1916                             (1 << IEEE80211_RADIOTAP_RATE) |
1917                             (1 << IEEE80211_RADIOTAP_CHANNEL));
1918
1919         rthdr->rate = rx->rate->bitrate / 5;
1920         rthdr->chan_freq = cpu_to_le16(status->freq);
1921
1922         if (status->band == IEEE80211_BAND_5GHZ)
1923                 rthdr->chan_flags = cpu_to_le16(IEEE80211_CHAN_OFDM |
1924                                                 IEEE80211_CHAN_5GHZ);
1925         else
1926                 rthdr->chan_flags = cpu_to_le16(IEEE80211_CHAN_DYN |
1927                                                 IEEE80211_CHAN_2GHZ);
1928
1929         skb_set_mac_header(skb, 0);
1930         skb->ip_summed = CHECKSUM_UNNECESSARY;
1931         skb->pkt_type = PACKET_OTHERHOST;
1932         skb->protocol = htons(ETH_P_802_2);
1933
1934         list_for_each_entry_rcu(sdata, &local->interfaces, list) {
1935                 if (!netif_running(sdata->dev))
1936                         continue;
1937
1938                 if (sdata->vif.type != NL80211_IFTYPE_MONITOR ||
1939                     !(sdata->u.mntr_flags & MONITOR_FLAG_COOK_FRAMES))
1940                         continue;
1941
1942                 if (prev_dev) {
1943                         skb2 = skb_clone(skb, GFP_ATOMIC);
1944                         if (skb2) {
1945                                 skb2->dev = prev_dev;
1946                                 netif_rx(skb2);
1947                         }
1948                 }
1949
1950                 prev_dev = sdata->dev;
1951                 sdata->dev->stats.rx_packets++;
1952                 sdata->dev->stats.rx_bytes += skb->len;
1953         }
1954
1955         if (prev_dev) {
1956                 skb->dev = prev_dev;
1957                 netif_rx(skb);
1958                 skb = NULL;
1959         } else
1960                 goto out_free_skb;
1961
1962         rx->flags |= IEEE80211_RX_CMNTR_REPORTED;
1963         return;
1964
1965  out_free_skb:
1966         dev_kfree_skb(skb);
1967 }
1968
1969
1970 static void ieee80211_invoke_rx_handlers(struct ieee80211_sub_if_data *sdata,
1971                                          struct ieee80211_rx_data *rx,
1972                                          struct sk_buff *skb)
1973 {
1974         ieee80211_rx_result res = RX_DROP_MONITOR;
1975
1976         rx->skb = skb;
1977         rx->sdata = sdata;
1978         rx->dev = sdata->dev;
1979
1980 #define CALL_RXH(rxh)                   \
1981         do {                            \
1982                 res = rxh(rx);          \
1983                 if (res != RX_CONTINUE) \
1984                         goto rxh_done;  \
1985         } while (0);
1986
1987         CALL_RXH(ieee80211_rx_h_passive_scan)
1988         CALL_RXH(ieee80211_rx_h_check)
1989         CALL_RXH(ieee80211_rx_h_decrypt)
1990         CALL_RXH(ieee80211_rx_h_check_more_data)
1991         CALL_RXH(ieee80211_rx_h_sta_process)
1992         CALL_RXH(ieee80211_rx_h_defragment)
1993         CALL_RXH(ieee80211_rx_h_ps_poll)
1994         CALL_RXH(ieee80211_rx_h_michael_mic_verify)
1995         /* must be after MMIC verify so header is counted in MPDU mic */
1996         CALL_RXH(ieee80211_rx_h_remove_qos_control)
1997         CALL_RXH(ieee80211_rx_h_amsdu)
1998 #ifdef CONFIG_MAC80211_MESH
1999         if (ieee80211_vif_is_mesh(&sdata->vif))
2000                 CALL_RXH(ieee80211_rx_h_mesh_fwding);
2001 #endif
2002         CALL_RXH(ieee80211_rx_h_data)
2003         CALL_RXH(ieee80211_rx_h_ctrl)
2004         CALL_RXH(ieee80211_rx_h_action)
2005         CALL_RXH(ieee80211_rx_h_mgmt)
2006
2007 #undef CALL_RXH
2008
2009  rxh_done:
2010         switch (res) {
2011         case RX_DROP_MONITOR:
2012                 I802_DEBUG_INC(sdata->local->rx_handlers_drop);
2013                 if (rx->sta)
2014                         rx->sta->rx_dropped++;
2015                 /* fall through */
2016         case RX_CONTINUE:
2017                 ieee80211_rx_cooked_monitor(rx);
2018                 break;
2019         case RX_DROP_UNUSABLE:
2020                 I802_DEBUG_INC(sdata->local->rx_handlers_drop);
2021                 if (rx->sta)
2022                         rx->sta->rx_dropped++;
2023                 dev_kfree_skb(rx->skb);
2024                 break;
2025         case RX_QUEUED:
2026                 I802_DEBUG_INC(sdata->local->rx_handlers_queued);
2027                 break;
2028         }
2029 }
2030
2031 /* main receive path */
2032
2033 static int prepare_for_handlers(struct ieee80211_sub_if_data *sdata,
2034                                 struct ieee80211_rx_data *rx,
2035                                 struct ieee80211_hdr *hdr)
2036 {
2037         u8 *bssid = ieee80211_get_bssid(hdr, rx->skb->len, sdata->vif.type);
2038         int multicast = is_multicast_ether_addr(hdr->addr1);
2039
2040         switch (sdata->vif.type) {
2041         case NL80211_IFTYPE_STATION:
2042                 if (!bssid)
2043                         return 0;
2044                 if (!multicast &&
2045                     compare_ether_addr(sdata->dev->dev_addr, hdr->addr1) != 0) {
2046                         if (!(sdata->dev->flags & IFF_PROMISC))
2047                                 return 0;
2048                         rx->flags &= ~IEEE80211_RX_RA_MATCH;
2049                 }
2050                 break;
2051         case NL80211_IFTYPE_ADHOC:
2052                 if (!bssid)
2053                         return 0;
2054                 if (ieee80211_is_beacon(hdr->frame_control)) {
2055                         return 1;
2056                 }
2057                 else if (!ieee80211_bssid_match(bssid, sdata->u.ibss.bssid)) {
2058                         if (!(rx->flags & IEEE80211_RX_IN_SCAN))
2059                                 return 0;
2060                         rx->flags &= ~IEEE80211_RX_RA_MATCH;
2061                 } else if (!multicast &&
2062                            compare_ether_addr(sdata->dev->dev_addr,
2063                                               hdr->addr1) != 0) {
2064                         if (!(sdata->dev->flags & IFF_PROMISC))
2065                                 return 0;
2066                         rx->flags &= ~IEEE80211_RX_RA_MATCH;
2067                 } else if (!rx->sta) {
2068                         int rate_idx;
2069                         if (rx->status->flag & RX_FLAG_HT)
2070                                 rate_idx = 0; /* TODO: HT rates */
2071                         else
2072                                 rate_idx = rx->status->rate_idx;
2073                         rx->sta = ieee80211_ibss_add_sta(sdata, bssid, hdr->addr2,
2074                                 BIT(rate_idx));
2075                 }
2076                 break;
2077         case NL80211_IFTYPE_MESH_POINT:
2078                 if (!multicast &&
2079                     compare_ether_addr(sdata->dev->dev_addr,
2080                                        hdr->addr1) != 0) {
2081                         if (!(sdata->dev->flags & IFF_PROMISC))
2082                                 return 0;
2083
2084                         rx->flags &= ~IEEE80211_RX_RA_MATCH;
2085                 }
2086                 break;
2087         case NL80211_IFTYPE_AP_VLAN:
2088         case NL80211_IFTYPE_AP:
2089                 if (!bssid) {
2090                         if (compare_ether_addr(sdata->dev->dev_addr,
2091                                                hdr->addr1))
2092                                 return 0;
2093                 } else if (!ieee80211_bssid_match(bssid,
2094                                         sdata->dev->dev_addr)) {
2095                         if (!(rx->flags & IEEE80211_RX_IN_SCAN))
2096                                 return 0;
2097                         rx->flags &= ~IEEE80211_RX_RA_MATCH;
2098                 }
2099                 break;
2100         case NL80211_IFTYPE_WDS:
2101                 if (bssid || !ieee80211_is_data(hdr->frame_control))
2102                         return 0;
2103                 if (compare_ether_addr(sdata->u.wds.remote_addr, hdr->addr2))
2104                         return 0;
2105                 break;
2106         case NL80211_IFTYPE_MONITOR:
2107                 /* take everything */
2108                 break;
2109         case NL80211_IFTYPE_UNSPECIFIED:
2110         case __NL80211_IFTYPE_AFTER_LAST:
2111                 /* should never get here */
2112                 WARN_ON(1);
2113                 break;
2114         }
2115
2116         return 1;
2117 }
2118
2119 /*
2120  * This is the actual Rx frames handler. as it blongs to Rx path it must
2121  * be called with rcu_read_lock protection.
2122  */
2123 static void __ieee80211_rx_handle_packet(struct ieee80211_hw *hw,
2124                                          struct sk_buff *skb,
2125                                          struct ieee80211_rate *rate)
2126 {
2127         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
2128         struct ieee80211_local *local = hw_to_local(hw);
2129         struct ieee80211_sub_if_data *sdata;
2130         struct ieee80211_hdr *hdr;
2131         struct ieee80211_rx_data rx;
2132         int prepares;
2133         struct ieee80211_sub_if_data *prev = NULL;
2134         struct sk_buff *skb_new;
2135
2136         hdr = (struct ieee80211_hdr *)skb->data;
2137         memset(&rx, 0, sizeof(rx));
2138         rx.skb = skb;
2139         rx.local = local;
2140
2141         rx.status = status;
2142         rx.rate = rate;
2143
2144         if (ieee80211_is_data(hdr->frame_control) || ieee80211_is_mgmt(hdr->frame_control))
2145                 local->dot11ReceivedFragmentCount++;
2146
2147         rx.sta = sta_info_get(local, hdr->addr2);
2148         if (rx.sta) {
2149                 rx.sdata = rx.sta->sdata;
2150                 rx.dev = rx.sta->sdata->dev;
2151         }
2152
2153         if ((status->flag & RX_FLAG_MMIC_ERROR)) {
2154                 ieee80211_rx_michael_mic_report(hdr, &rx);
2155                 return;
2156         }
2157
2158         if (unlikely(test_bit(SCAN_HW_SCANNING, &local->scanning) ||
2159                      test_bit(SCAN_OFF_CHANNEL, &local->scanning)))
2160                 rx.flags |= IEEE80211_RX_IN_SCAN;
2161
2162         ieee80211_parse_qos(&rx);
2163         ieee80211_verify_alignment(&rx);
2164
2165         skb = rx.skb;
2166
2167         if (rx.sdata && ieee80211_is_data(hdr->frame_control)) {
2168                 rx.flags |= IEEE80211_RX_RA_MATCH;
2169                 prepares = prepare_for_handlers(rx.sdata, &rx, hdr);
2170                 if (prepares)
2171                         prev = rx.sdata;
2172         } else list_for_each_entry_rcu(sdata, &local->interfaces, list) {
2173                 if (!netif_running(sdata->dev))
2174                         continue;
2175
2176                 if (sdata->vif.type == NL80211_IFTYPE_MONITOR ||
2177                     sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
2178                         continue;
2179
2180                 rx.flags |= IEEE80211_RX_RA_MATCH;
2181                 prepares = prepare_for_handlers(sdata, &rx, hdr);
2182
2183                 if (!prepares)
2184                         continue;
2185
2186                 /*
2187                  * frame is destined for this interface, but if it's not
2188                  * also for the previous one we handle that after the
2189                  * loop to avoid copying the SKB once too much
2190                  */
2191
2192                 if (!prev) {
2193                         prev = sdata;
2194                         continue;
2195                 }
2196
2197                 /*
2198                  * frame was destined for the previous interface
2199                  * so invoke RX handlers for it
2200                  */
2201
2202                 skb_new = skb_copy(skb, GFP_ATOMIC);
2203                 if (!skb_new) {
2204                         if (net_ratelimit())
2205                                 printk(KERN_DEBUG "%s: failed to copy "
2206                                        "multicast frame for %s\n",
2207                                        wiphy_name(local->hw.wiphy),
2208                                        prev->dev->name);
2209                         continue;
2210                 }
2211                 ieee80211_invoke_rx_handlers(prev, &rx, skb_new);
2212                 prev = sdata;
2213         }
2214         if (prev)
2215                 ieee80211_invoke_rx_handlers(prev, &rx, skb);
2216         else
2217                 dev_kfree_skb(skb);
2218 }
2219
2220 #define SEQ_MODULO 0x1000
2221 #define SEQ_MASK   0xfff
2222
2223 static inline int seq_less(u16 sq1, u16 sq2)
2224 {
2225         return ((sq1 - sq2) & SEQ_MASK) > (SEQ_MODULO >> 1);
2226 }
2227
2228 static inline u16 seq_inc(u16 sq)
2229 {
2230         return (sq + 1) & SEQ_MASK;
2231 }
2232
2233 static inline u16 seq_sub(u16 sq1, u16 sq2)
2234 {
2235         return (sq1 - sq2) & SEQ_MASK;
2236 }
2237
2238
2239 static void ieee80211_release_reorder_frame(struct ieee80211_hw *hw,
2240                                             struct tid_ampdu_rx *tid_agg_rx,
2241                                             int index)
2242 {
2243         struct ieee80211_supported_band *sband;
2244         struct ieee80211_rate *rate;
2245         struct sk_buff *skb = tid_agg_rx->reorder_buf[index];
2246         struct ieee80211_rx_status *status;
2247
2248         if (!skb)
2249                 goto no_frame;
2250
2251         status = IEEE80211_SKB_RXCB(skb);
2252
2253         /* release the reordered frames to stack */
2254         sband = hw->wiphy->bands[status->band];
2255         if (status->flag & RX_FLAG_HT)
2256                 rate = sband->bitrates; /* TODO: HT rates */
2257         else
2258                 rate = &sband->bitrates[status->rate_idx];
2259         __ieee80211_rx_handle_packet(hw, skb, rate);
2260         tid_agg_rx->stored_mpdu_num--;
2261         tid_agg_rx->reorder_buf[index] = NULL;
2262
2263 no_frame:
2264         tid_agg_rx->head_seq_num = seq_inc(tid_agg_rx->head_seq_num);
2265 }
2266
2267
2268 /*
2269  * Timeout (in jiffies) for skb's that are waiting in the RX reorder buffer. If
2270  * the skb was added to the buffer longer than this time ago, the earlier
2271  * frames that have not yet been received are assumed to be lost and the skb
2272  * can be released for processing. This may also release other skb's from the
2273  * reorder buffer if there are no additional gaps between the frames.
2274  */
2275 #define HT_RX_REORDER_BUF_TIMEOUT (HZ / 10)
2276
2277 /*
2278  * As it function blongs to Rx path it must be called with
2279  * the proper rcu_read_lock protection for its flow.
2280  */
2281 static u8 ieee80211_sta_manage_reorder_buf(struct ieee80211_hw *hw,
2282                                            struct tid_ampdu_rx *tid_agg_rx,
2283                                            struct sk_buff *skb,
2284                                            u16 mpdu_seq_num,
2285                                            int bar_req)
2286 {
2287         u16 head_seq_num, buf_size;
2288         int index;
2289
2290         buf_size = tid_agg_rx->buf_size;
2291         head_seq_num = tid_agg_rx->head_seq_num;
2292
2293         /* frame with out of date sequence number */
2294         if (seq_less(mpdu_seq_num, head_seq_num)) {
2295                 dev_kfree_skb(skb);
2296                 return 1;
2297         }
2298
2299         /* if frame sequence number exceeds our buffering window size or
2300          * block Ack Request arrived - release stored frames */
2301         if ((!seq_less(mpdu_seq_num, head_seq_num + buf_size)) || (bar_req)) {
2302                 /* new head to the ordering buffer */
2303                 if (bar_req)
2304                         head_seq_num = mpdu_seq_num;
2305                 else
2306                         head_seq_num =
2307                                 seq_inc(seq_sub(mpdu_seq_num, buf_size));
2308                 /* release stored frames up to new head to stack */
2309                 while (seq_less(tid_agg_rx->head_seq_num, head_seq_num)) {
2310                         index = seq_sub(tid_agg_rx->head_seq_num,
2311                                 tid_agg_rx->ssn)
2312                                 % tid_agg_rx->buf_size;
2313                         ieee80211_release_reorder_frame(hw, tid_agg_rx,
2314                                                         index);
2315                 }
2316                 if (bar_req)
2317                         return 1;
2318         }
2319
2320         /* now the new frame is always in the range of the reordering */
2321         /* buffer window */
2322         index = seq_sub(mpdu_seq_num, tid_agg_rx->ssn)
2323                                 % tid_agg_rx->buf_size;
2324         /* check if we already stored this frame */
2325         if (tid_agg_rx->reorder_buf[index]) {
2326                 dev_kfree_skb(skb);
2327                 return 1;
2328         }
2329
2330         /* if arrived mpdu is in the right order and nothing else stored */
2331         /* release it immediately */
2332         if (mpdu_seq_num == tid_agg_rx->head_seq_num &&
2333                         tid_agg_rx->stored_mpdu_num == 0) {
2334                 tid_agg_rx->head_seq_num =
2335                         seq_inc(tid_agg_rx->head_seq_num);
2336                 return 0;
2337         }
2338
2339         /* put the frame in the reordering buffer */
2340         tid_agg_rx->reorder_buf[index] = skb;
2341         tid_agg_rx->reorder_time[index] = jiffies;
2342         tid_agg_rx->stored_mpdu_num++;
2343         /* release the buffer until next missing frame */
2344         index = seq_sub(tid_agg_rx->head_seq_num, tid_agg_rx->ssn)
2345                                                 % tid_agg_rx->buf_size;
2346         if (!tid_agg_rx->reorder_buf[index] &&
2347             tid_agg_rx->stored_mpdu_num > 1) {
2348                 /*
2349                  * No buffers ready to be released, but check whether any
2350                  * frames in the reorder buffer have timed out.
2351                  */
2352                 int j;
2353                 int skipped = 1;
2354                 for (j = (index + 1) % tid_agg_rx->buf_size; j != index;
2355                      j = (j + 1) % tid_agg_rx->buf_size) {
2356                         if (tid_agg_rx->reorder_buf[j] == NULL) {
2357                                 skipped++;
2358                                 continue;
2359                         }
2360                         if (!time_after(jiffies, tid_agg_rx->reorder_time[j] +
2361                                         HZ / 10))
2362                                 break;
2363
2364 #ifdef CONFIG_MAC80211_HT_DEBUG
2365                         if (net_ratelimit())
2366                                 printk(KERN_DEBUG "%s: release an RX reorder "
2367                                        "frame due to timeout on earlier "
2368                                        "frames\n",
2369                                        wiphy_name(hw->wiphy));
2370 #endif
2371                         ieee80211_release_reorder_frame(hw, tid_agg_rx, j);
2372
2373                         /*
2374                          * Increment the head seq# also for the skipped slots.
2375                          */
2376                         tid_agg_rx->head_seq_num =
2377                                 (tid_agg_rx->head_seq_num + skipped) &
2378                                 SEQ_MASK;
2379                         skipped = 0;
2380                 }
2381         } else while (tid_agg_rx->reorder_buf[index]) {
2382                 ieee80211_release_reorder_frame(hw, tid_agg_rx, index);
2383                 index = seq_sub(tid_agg_rx->head_seq_num,
2384                         tid_agg_rx->ssn) % tid_agg_rx->buf_size;
2385         }
2386         return 1;
2387 }
2388
2389 static u8 ieee80211_rx_reorder_ampdu(struct ieee80211_local *local,
2390                                      struct sk_buff *skb)
2391 {
2392         struct ieee80211_hw *hw = &local->hw;
2393         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
2394         struct sta_info *sta;
2395         struct tid_ampdu_rx *tid_agg_rx;
2396         u16 sc;
2397         u16 mpdu_seq_num;
2398         u8 ret = 0;
2399         int tid;
2400
2401         sta = sta_info_get(local, hdr->addr2);
2402         if (!sta)
2403                 return ret;
2404
2405         /* filter the QoS data rx stream according to
2406          * STA/TID and check if this STA/TID is on aggregation */
2407         if (!ieee80211_is_data_qos(hdr->frame_control))
2408                 goto end_reorder;
2409
2410         tid = *ieee80211_get_qos_ctl(hdr) & IEEE80211_QOS_CTL_TID_MASK;
2411
2412         if (sta->ampdu_mlme.tid_state_rx[tid] != HT_AGG_STATE_OPERATIONAL)
2413                 goto end_reorder;
2414
2415         tid_agg_rx = sta->ampdu_mlme.tid_rx[tid];
2416
2417         /* qos null data frames are excluded */
2418         if (unlikely(hdr->frame_control & cpu_to_le16(IEEE80211_STYPE_NULLFUNC)))
2419                 goto end_reorder;
2420
2421         /* new un-ordered ampdu frame - process it */
2422
2423         /* reset session timer */
2424         if (tid_agg_rx->timeout)
2425                 mod_timer(&tid_agg_rx->session_timer,
2426                           TU_TO_EXP_TIME(tid_agg_rx->timeout));
2427
2428         /* if this mpdu is fragmented - terminate rx aggregation session */
2429         sc = le16_to_cpu(hdr->seq_ctrl);
2430         if (sc & IEEE80211_SCTL_FRAG) {
2431                 ieee80211_sta_stop_rx_ba_session(sta->sdata, sta->sta.addr,
2432                         tid, 0, WLAN_REASON_QSTA_REQUIRE_SETUP);
2433                 ret = 1;
2434                 goto end_reorder;
2435         }
2436
2437         /* according to mpdu sequence number deal with reordering buffer */
2438         mpdu_seq_num = (sc & IEEE80211_SCTL_SEQ) >> 4;
2439         ret = ieee80211_sta_manage_reorder_buf(hw, tid_agg_rx, skb,
2440                                                 mpdu_seq_num, 0);
2441  end_reorder:
2442         return ret;
2443 }
2444
2445 /*
2446  * This is the receive path handler. It is called by a low level driver when an
2447  * 802.11 MPDU is received from the hardware.
2448  */
2449 void ieee80211_rx(struct ieee80211_hw *hw, struct sk_buff *skb)
2450 {
2451         struct ieee80211_local *local = hw_to_local(hw);
2452         struct ieee80211_rate *rate = NULL;
2453         struct ieee80211_supported_band *sband;
2454         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
2455
2456         WARN_ON_ONCE(softirq_count() == 0);
2457
2458         if (WARN_ON(status->band < 0 ||
2459                     status->band >= IEEE80211_NUM_BANDS))
2460                 goto drop;
2461
2462         sband = local->hw.wiphy->bands[status->band];
2463         if (WARN_ON(!sband))
2464                 goto drop;
2465
2466         /*
2467          * If we're suspending, it is possible although not too likely
2468          * that we'd be receiving frames after having already partially
2469          * quiesced the stack. We can't process such frames then since
2470          * that might, for example, cause stations to be added or other
2471          * driver callbacks be invoked.
2472          */
2473         if (unlikely(local->quiescing || local->suspended))
2474                 goto drop;
2475
2476         /*
2477          * The same happens when we're not even started,
2478          * but that's worth a warning.
2479          */
2480         if (WARN_ON(!local->started))
2481                 goto drop;
2482
2483         if (status->flag & RX_FLAG_HT) {
2484                 /* rate_idx is MCS index */
2485                 if (WARN_ON(status->rate_idx < 0 ||
2486                             status->rate_idx >= 76))
2487                         goto drop;
2488                 /* HT rates are not in the table - use the highest legacy rate
2489                  * for now since other parts of mac80211 may not yet be fully
2490                  * MCS aware. */
2491                 rate = &sband->bitrates[sband->n_bitrates - 1];
2492         } else {
2493                 if (WARN_ON(status->rate_idx < 0 ||
2494                             status->rate_idx >= sband->n_bitrates))
2495                         goto drop;
2496                 rate = &sband->bitrates[status->rate_idx];
2497         }
2498
2499         /*
2500          * key references and virtual interfaces are protected using RCU
2501          * and this requires that we are in a read-side RCU section during
2502          * receive processing
2503          */
2504         rcu_read_lock();
2505
2506         /*
2507          * Frames with failed FCS/PLCP checksum are not returned,
2508          * all other frames are returned without radiotap header
2509          * if it was previously present.
2510          * Also, frames with less than 16 bytes are dropped.
2511          */
2512         skb = ieee80211_rx_monitor(local, skb, rate);
2513         if (!skb) {
2514                 rcu_read_unlock();
2515                 return;
2516         }
2517
2518         /*
2519          * In theory, the block ack reordering should happen after duplicate
2520          * removal (ieee80211_rx_h_check(), which is an RX handler). As such,
2521          * the call to ieee80211_rx_reorder_ampdu() should really be moved to
2522          * happen as a new RX handler between ieee80211_rx_h_check and
2523          * ieee80211_rx_h_decrypt. This cleanup may eventually happen, but for
2524          * the time being, the call can be here since RX reorder buf processing
2525          * will implicitly skip duplicates. We could, in theory at least,
2526          * process frames that ieee80211_rx_h_passive_scan would drop (e.g.,
2527          * frames from other than operational channel), but that should not
2528          * happen in normal networks.
2529          */
2530         if (!ieee80211_rx_reorder_ampdu(local, skb))
2531                 __ieee80211_rx_handle_packet(hw, skb, rate);
2532
2533         rcu_read_unlock();
2534
2535         return;
2536  drop:
2537         kfree_skb(skb);
2538 }
2539 EXPORT_SYMBOL(ieee80211_rx);
2540
2541 /* This is a version of the rx handler that can be called from hard irq
2542  * context. Post the skb on the queue and schedule the tasklet */
2543 void ieee80211_rx_irqsafe(struct ieee80211_hw *hw, struct sk_buff *skb)
2544 {
2545         struct ieee80211_local *local = hw_to_local(hw);
2546
2547         BUILD_BUG_ON(sizeof(struct ieee80211_rx_status) > sizeof(skb->cb));
2548
2549         skb->pkt_type = IEEE80211_RX_MSG;
2550         skb_queue_tail(&local->skb_queue, skb);
2551         tasklet_schedule(&local->tasklet);
2552 }
2553 EXPORT_SYMBOL(ieee80211_rx_irqsafe);