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TOMOYO Linux Cross Reference
Linux/net/mac80211/tx.c

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  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  * Transmit and frame generation functions.
 13  */
 14 
 15 #include <linux/kernel.h>
 16 #include <linux/slab.h>
 17 #include <linux/skbuff.h>
 18 #include <linux/etherdevice.h>
 19 #include <linux/bitmap.h>
 20 #include <linux/rcupdate.h>
 21 #include <linux/export.h>
 22 #include <net/net_namespace.h>
 23 #include <net/ieee80211_radiotap.h>
 24 #include <net/cfg80211.h>
 25 #include <net/mac80211.h>
 26 #include <asm/unaligned.h>
 27 
 28 #include "ieee80211_i.h"
 29 #include "driver-ops.h"
 30 #include "led.h"
 31 #include "mesh.h"
 32 #include "wep.h"
 33 #include "wpa.h"
 34 #include "wme.h"
 35 #include "rate.h"
 36 
 37 /* misc utils */
 38 
 39 static __le16 ieee80211_duration(struct ieee80211_tx_data *tx,
 40                                  struct sk_buff *skb, int group_addr,
 41                                  int next_frag_len)
 42 {
 43         int rate, mrate, erp, dur, i;
 44         struct ieee80211_rate *txrate;
 45         struct ieee80211_local *local = tx->local;
 46         struct ieee80211_supported_band *sband;
 47         struct ieee80211_hdr *hdr;
 48         struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
 49 
 50         /* assume HW handles this */
 51         if (info->control.rates[0].flags & IEEE80211_TX_RC_MCS)
 52                 return 0;
 53 
 54         /* uh huh? */
 55         if (WARN_ON_ONCE(info->control.rates[0].idx < 0))
 56                 return 0;
 57 
 58         sband = local->hw.wiphy->bands[tx->channel->band];
 59         txrate = &sband->bitrates[info->control.rates[0].idx];
 60 
 61         erp = txrate->flags & IEEE80211_RATE_ERP_G;
 62 
 63         /*
 64          * data and mgmt (except PS Poll):
 65          * - during CFP: 32768
 66          * - during contention period:
 67          *   if addr1 is group address: 0
 68          *   if more fragments = 0 and addr1 is individual address: time to
 69          *      transmit one ACK plus SIFS
 70          *   if more fragments = 1 and addr1 is individual address: time to
 71          *      transmit next fragment plus 2 x ACK plus 3 x SIFS
 72          *
 73          * IEEE 802.11, 9.6:
 74          * - control response frame (CTS or ACK) shall be transmitted using the
 75          *   same rate as the immediately previous frame in the frame exchange
 76          *   sequence, if this rate belongs to the PHY mandatory rates, or else
 77          *   at the highest possible rate belonging to the PHY rates in the
 78          *   BSSBasicRateSet
 79          */
 80         hdr = (struct ieee80211_hdr *)skb->data;
 81         if (ieee80211_is_ctl(hdr->frame_control)) {
 82                 /* TODO: These control frames are not currently sent by
 83                  * mac80211, but should they be implemented, this function
 84                  * needs to be updated to support duration field calculation.
 85                  *
 86                  * RTS: time needed to transmit pending data/mgmt frame plus
 87                  *    one CTS frame plus one ACK frame plus 3 x SIFS
 88                  * CTS: duration of immediately previous RTS minus time
 89                  *    required to transmit CTS and its SIFS
 90                  * ACK: 0 if immediately previous directed data/mgmt had
 91                  *    more=0, with more=1 duration in ACK frame is duration
 92                  *    from previous frame minus time needed to transmit ACK
 93                  *    and its SIFS
 94                  * PS Poll: BIT(15) | BIT(14) | aid
 95                  */
 96                 return 0;
 97         }
 98 
 99         /* data/mgmt */
100         if (0 /* FIX: data/mgmt during CFP */)
101                 return cpu_to_le16(32768);
102 
103         if (group_addr) /* Group address as the destination - no ACK */
104                 return 0;
105 
106         /* Individual destination address:
107          * IEEE 802.11, Ch. 9.6 (after IEEE 802.11g changes)
108          * CTS and ACK frames shall be transmitted using the highest rate in
109          * basic rate set that is less than or equal to the rate of the
110          * immediately previous frame and that is using the same modulation
111          * (CCK or OFDM). If no basic rate set matches with these requirements,
112          * the highest mandatory rate of the PHY that is less than or equal to
113          * the rate of the previous frame is used.
114          * Mandatory rates for IEEE 802.11g PHY: 1, 2, 5.5, 11, 6, 12, 24 Mbps
115          */
116         rate = -1;
117         /* use lowest available if everything fails */
118         mrate = sband->bitrates[0].bitrate;
119         for (i = 0; i < sband->n_bitrates; i++) {
120                 struct ieee80211_rate *r = &sband->bitrates[i];
121 
122                 if (r->bitrate > txrate->bitrate)
123                         break;
124 
125                 if (tx->sdata->vif.bss_conf.basic_rates & BIT(i))
126                         rate = r->bitrate;
127 
128                 switch (sband->band) {
129                 case IEEE80211_BAND_2GHZ: {
130                         u32 flag;
131                         if (tx->sdata->flags & IEEE80211_SDATA_OPERATING_GMODE)
132                                 flag = IEEE80211_RATE_MANDATORY_G;
133                         else
134                                 flag = IEEE80211_RATE_MANDATORY_B;
135                         if (r->flags & flag)
136                                 mrate = r->bitrate;
137                         break;
138                 }
139                 case IEEE80211_BAND_5GHZ:
140                         if (r->flags & IEEE80211_RATE_MANDATORY_A)
141                                 mrate = r->bitrate;
142                         break;
143                 case IEEE80211_NUM_BANDS:
144                         WARN_ON(1);
145                         break;
146                 }
147         }
148         if (rate == -1) {
149                 /* No matching basic rate found; use highest suitable mandatory
150                  * PHY rate */
151                 rate = mrate;
152         }
153 
154         /* Don't calculate ACKs for QoS Frames with NoAck Policy set */
155         if (ieee80211_is_data_qos(hdr->frame_control) &&
156             *(ieee80211_get_qos_ctl(hdr)) & IEEE80211_QOS_CTL_ACK_POLICY_NOACK)
157                 dur = 0;
158         else
159                 /* Time needed to transmit ACK
160                  * (10 bytes + 4-byte FCS = 112 bits) plus SIFS; rounded up
161                  * to closest integer */
162                 dur = ieee80211_frame_duration(sband->band, 10, rate, erp,
163                                 tx->sdata->vif.bss_conf.use_short_preamble);
164 
165         if (next_frag_len) {
166                 /* Frame is fragmented: duration increases with time needed to
167                  * transmit next fragment plus ACK and 2 x SIFS. */
168                 dur *= 2; /* ACK + SIFS */
169                 /* next fragment */
170                 dur += ieee80211_frame_duration(sband->band, next_frag_len,
171                                 txrate->bitrate, erp,
172                                 tx->sdata->vif.bss_conf.use_short_preamble);
173         }
174 
175         return cpu_to_le16(dur);
176 }
177 
178 static inline int is_ieee80211_device(struct ieee80211_local *local,
179                                       struct net_device *dev)
180 {
181         return local == wdev_priv(dev->ieee80211_ptr);
182 }
183 
184 /* tx handlers */
185 static ieee80211_tx_result debug_noinline
186 ieee80211_tx_h_dynamic_ps(struct ieee80211_tx_data *tx)
187 {
188         struct ieee80211_local *local = tx->local;
189         struct ieee80211_if_managed *ifmgd;
190 
191         /* driver doesn't support power save */
192         if (!(local->hw.flags & IEEE80211_HW_SUPPORTS_PS))
193                 return TX_CONTINUE;
194 
195         /* hardware does dynamic power save */
196         if (local->hw.flags & IEEE80211_HW_SUPPORTS_DYNAMIC_PS)
197                 return TX_CONTINUE;
198 
199         /* dynamic power save disabled */
200         if (local->hw.conf.dynamic_ps_timeout <= 0)
201                 return TX_CONTINUE;
202 
203         /* we are scanning, don't enable power save */
204         if (local->scanning)
205                 return TX_CONTINUE;
206 
207         if (!local->ps_sdata)
208                 return TX_CONTINUE;
209 
210         /* No point if we're going to suspend */
211         if (local->quiescing)
212                 return TX_CONTINUE;
213 
214         /* dynamic ps is supported only in managed mode */
215         if (tx->sdata->vif.type != NL80211_IFTYPE_STATION)
216                 return TX_CONTINUE;
217 
218         ifmgd = &tx->sdata->u.mgd;
219 
220         /*
221          * Don't wakeup from power save if u-apsd is enabled, voip ac has
222          * u-apsd enabled and the frame is in voip class. This effectively
223          * means that even if all access categories have u-apsd enabled, in
224          * practise u-apsd is only used with the voip ac. This is a
225          * workaround for the case when received voip class packets do not
226          * have correct qos tag for some reason, due the network or the
227          * peer application.
228          *
229          * Note: ifmgd->uapsd_queues access is racy here. If the value is
230          * changed via debugfs, user needs to reassociate manually to have
231          * everything in sync.
232          */
233         if ((ifmgd->flags & IEEE80211_STA_UAPSD_ENABLED) &&
234             (ifmgd->uapsd_queues & IEEE80211_WMM_IE_STA_QOSINFO_AC_VO) &&
235             skb_get_queue_mapping(tx->skb) == IEEE80211_AC_VO)
236                 return TX_CONTINUE;
237 
238         if (local->hw.conf.flags & IEEE80211_CONF_PS) {
239                 ieee80211_stop_queues_by_reason(&local->hw,
240                                                 IEEE80211_QUEUE_STOP_REASON_PS);
241                 ifmgd->flags &= ~IEEE80211_STA_NULLFUNC_ACKED;
242                 ieee80211_queue_work(&local->hw,
243                                      &local->dynamic_ps_disable_work);
244         }
245 
246         /* Don't restart the timer if we're not disassociated */
247         if (!ifmgd->associated)
248                 return TX_CONTINUE;
249 
250         mod_timer(&local->dynamic_ps_timer, jiffies +
251                   msecs_to_jiffies(local->hw.conf.dynamic_ps_timeout));
252 
253         return TX_CONTINUE;
254 }
255 
256 static ieee80211_tx_result debug_noinline
257 ieee80211_tx_h_check_assoc(struct ieee80211_tx_data *tx)
258 {
259 
260         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)tx->skb->data;
261         struct ieee80211_tx_info *info = IEEE80211_SKB_CB(tx->skb);
262         bool assoc = false;
263 
264         if (unlikely(info->flags & IEEE80211_TX_CTL_INJECTED))
265                 return TX_CONTINUE;
266 
267         if (unlikely(test_bit(SCAN_SW_SCANNING, &tx->local->scanning)) &&
268             test_bit(SDATA_STATE_OFFCHANNEL, &tx->sdata->state) &&
269             !ieee80211_is_probe_req(hdr->frame_control) &&
270             !ieee80211_is_nullfunc(hdr->frame_control))
271                 /*
272                  * When software scanning only nullfunc frames (to notify
273                  * the sleep state to the AP) and probe requests (for the
274                  * active scan) are allowed, all other frames should not be
275                  * sent and we should not get here, but if we do
276                  * nonetheless, drop them to avoid sending them
277                  * off-channel. See the link below and
278                  * ieee80211_start_scan() for more.
279                  *
280                  * http://article.gmane.org/gmane.linux.kernel.wireless.general/30089
281                  */
282                 return TX_DROP;
283 
284         if (tx->sdata->vif.type == NL80211_IFTYPE_WDS)
285                 return TX_CONTINUE;
286 
287         if (tx->sdata->vif.type == NL80211_IFTYPE_MESH_POINT)
288                 return TX_CONTINUE;
289 
290         if (tx->flags & IEEE80211_TX_PS_BUFFERED)
291                 return TX_CONTINUE;
292 
293         if (tx->sta)
294                 assoc = test_sta_flag(tx->sta, WLAN_STA_ASSOC);
295 
296         if (likely(tx->flags & IEEE80211_TX_UNICAST)) {
297                 if (unlikely(!assoc &&
298                              ieee80211_is_data(hdr->frame_control))) {
299 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG
300                         printk(KERN_DEBUG "%s: dropped data frame to not "
301                                "associated station %pM\n",
302                                tx->sdata->name, hdr->addr1);
303 #endif /* CONFIG_MAC80211_VERBOSE_DEBUG */
304                         I802_DEBUG_INC(tx->local->tx_handlers_drop_not_assoc);
305                         return TX_DROP;
306                 }
307         } else if (unlikely(tx->sdata->vif.type == NL80211_IFTYPE_AP &&
308                             ieee80211_is_data(hdr->frame_control) &&
309                             !atomic_read(&tx->sdata->u.ap.num_mcast_sta))) {
310                 /*
311                  * No associated STAs - no need to send multicast
312                  * frames.
313                  */
314                 return TX_DROP;
315         }
316 
317         return TX_CONTINUE;
318 }
319 
320 /* This function is called whenever the AP is about to exceed the maximum limit
321  * of buffered frames for power saving STAs. This situation should not really
322  * happen often during normal operation, so dropping the oldest buffered packet
323  * from each queue should be OK to make some room for new frames. */
324 static void purge_old_ps_buffers(struct ieee80211_local *local)
325 {
326         int total = 0, purged = 0;
327         struct sk_buff *skb;
328         struct ieee80211_sub_if_data *sdata;
329         struct sta_info *sta;
330 
331         /*
332          * virtual interfaces are protected by RCU
333          */
334         rcu_read_lock();
335 
336         list_for_each_entry_rcu(sdata, &local->interfaces, list) {
337                 struct ieee80211_if_ap *ap;
338                 if (sdata->vif.type != NL80211_IFTYPE_AP)
339                         continue;
340                 ap = &sdata->u.ap;
341                 skb = skb_dequeue(&ap->ps_bc_buf);
342                 if (skb) {
343                         purged++;
344                         dev_kfree_skb(skb);
345                 }
346                 total += skb_queue_len(&ap->ps_bc_buf);
347         }
348 
349         /*
350          * Drop one frame from each station from the lowest-priority
351          * AC that has frames at all.
352          */
353         list_for_each_entry_rcu(sta, &local->sta_list, list) {
354                 int ac;
355 
356                 for (ac = IEEE80211_AC_BK; ac >= IEEE80211_AC_VO; ac--) {
357                         skb = skb_dequeue(&sta->ps_tx_buf[ac]);
358                         total += skb_queue_len(&sta->ps_tx_buf[ac]);
359                         if (skb) {
360                                 purged++;
361                                 dev_kfree_skb(skb);
362                                 break;
363                         }
364                 }
365         }
366 
367         rcu_read_unlock();
368 
369         local->total_ps_buffered = total;
370 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
371         wiphy_debug(local->hw.wiphy, "PS buffers full - purged %d frames\n",
372                     purged);
373 #endif
374 }
375 
376 static ieee80211_tx_result
377 ieee80211_tx_h_multicast_ps_buf(struct ieee80211_tx_data *tx)
378 {
379         struct ieee80211_tx_info *info = IEEE80211_SKB_CB(tx->skb);
380         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)tx->skb->data;
381 
382         /*
383          * broadcast/multicast frame
384          *
385          * If any of the associated stations is in power save mode,
386          * the frame is buffered to be sent after DTIM beacon frame.
387          * This is done either by the hardware or us.
388          */
389 
390         /* powersaving STAs only in AP/VLAN mode */
391         if (!tx->sdata->bss)
392                 return TX_CONTINUE;
393 
394         /* no buffering for ordered frames */
395         if (ieee80211_has_order(hdr->frame_control))
396                 return TX_CONTINUE;
397 
398         /* no stations in PS mode */
399         if (!atomic_read(&tx->sdata->bss->num_sta_ps))
400                 return TX_CONTINUE;
401 
402         info->flags |= IEEE80211_TX_CTL_SEND_AFTER_DTIM;
403         if (tx->local->hw.flags & IEEE80211_HW_QUEUE_CONTROL)
404                 info->hw_queue = tx->sdata->vif.cab_queue;
405 
406         /* device releases frame after DTIM beacon */
407         if (!(tx->local->hw.flags & IEEE80211_HW_HOST_BROADCAST_PS_BUFFERING))
408                 return TX_CONTINUE;
409 
410         /* buffered in mac80211 */
411         if (tx->local->total_ps_buffered >= TOTAL_MAX_TX_BUFFER)
412                 purge_old_ps_buffers(tx->local);
413 
414         if (skb_queue_len(&tx->sdata->bss->ps_bc_buf) >= AP_MAX_BC_BUFFER) {
415 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
416                 net_dbg_ratelimited("%s: BC TX buffer full - dropping the oldest frame\n",
417                                     tx->sdata->name);
418 #endif
419                 dev_kfree_skb(skb_dequeue(&tx->sdata->bss->ps_bc_buf));
420         } else
421                 tx->local->total_ps_buffered++;
422 
423         skb_queue_tail(&tx->sdata->bss->ps_bc_buf, tx->skb);
424 
425         return TX_QUEUED;
426 }
427 
428 static int ieee80211_use_mfp(__le16 fc, struct sta_info *sta,
429                              struct sk_buff *skb)
430 {
431         if (!ieee80211_is_mgmt(fc))
432                 return 0;
433 
434         if (sta == NULL || !test_sta_flag(sta, WLAN_STA_MFP))
435                 return 0;
436 
437         if (!ieee80211_is_robust_mgmt_frame((struct ieee80211_hdr *)
438                                             skb->data))
439                 return 0;
440 
441         return 1;
442 }
443 
444 static ieee80211_tx_result
445 ieee80211_tx_h_unicast_ps_buf(struct ieee80211_tx_data *tx)
446 {
447         struct sta_info *sta = tx->sta;
448         struct ieee80211_tx_info *info = IEEE80211_SKB_CB(tx->skb);
449         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)tx->skb->data;
450         struct ieee80211_local *local = tx->local;
451 
452         if (unlikely(!sta))
453                 return TX_CONTINUE;
454 
455         if (unlikely((test_sta_flag(sta, WLAN_STA_PS_STA) ||
456                       test_sta_flag(sta, WLAN_STA_PS_DRIVER)) &&
457                      !(info->flags & IEEE80211_TX_CTL_NO_PS_BUFFER))) {
458                 int ac = skb_get_queue_mapping(tx->skb);
459 
460                 /* only deauth, disassoc and action are bufferable MMPDUs */
461                 if (ieee80211_is_mgmt(hdr->frame_control) &&
462                     !ieee80211_is_deauth(hdr->frame_control) &&
463                     !ieee80211_is_disassoc(hdr->frame_control) &&
464                     !ieee80211_is_action(hdr->frame_control)) {
465                         info->flags |= IEEE80211_TX_CTL_NO_PS_BUFFER;
466                         return TX_CONTINUE;
467                 }
468 
469 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
470                 printk(KERN_DEBUG "STA %pM aid %d: PS buffer for AC %d\n",
471                        sta->sta.addr, sta->sta.aid, ac);
472 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
473                 if (tx->local->total_ps_buffered >= TOTAL_MAX_TX_BUFFER)
474                         purge_old_ps_buffers(tx->local);
475                 if (skb_queue_len(&sta->ps_tx_buf[ac]) >= STA_MAX_TX_BUFFER) {
476                         struct sk_buff *old = skb_dequeue(&sta->ps_tx_buf[ac]);
477 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
478                         net_dbg_ratelimited("%s: STA %pM TX buffer for AC %d full - dropping oldest frame\n",
479                                             tx->sdata->name, sta->sta.addr, ac);
480 #endif
481                         dev_kfree_skb(old);
482                 } else
483                         tx->local->total_ps_buffered++;
484 
485                 info->control.jiffies = jiffies;
486                 info->control.vif = &tx->sdata->vif;
487                 info->flags |= IEEE80211_TX_INTFL_NEED_TXPROCESSING;
488                 skb_queue_tail(&sta->ps_tx_buf[ac], tx->skb);
489 
490                 if (!timer_pending(&local->sta_cleanup))
491                         mod_timer(&local->sta_cleanup,
492                                   round_jiffies(jiffies +
493                                                 STA_INFO_CLEANUP_INTERVAL));
494 
495                 /*
496                  * We queued up some frames, so the TIM bit might
497                  * need to be set, recalculate it.
498                  */
499                 sta_info_recalc_tim(sta);
500 
501                 return TX_QUEUED;
502         }
503 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
504         else if (unlikely(test_sta_flag(sta, WLAN_STA_PS_STA))) {
505                 printk(KERN_DEBUG
506                        "%s: STA %pM in PS mode, but polling/in SP -> send frame\n",
507                        tx->sdata->name, sta->sta.addr);
508         }
509 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
510 
511         return TX_CONTINUE;
512 }
513 
514 static ieee80211_tx_result debug_noinline
515 ieee80211_tx_h_ps_buf(struct ieee80211_tx_data *tx)
516 {
517         if (unlikely(tx->flags & IEEE80211_TX_PS_BUFFERED))
518                 return TX_CONTINUE;
519 
520         if (tx->flags & IEEE80211_TX_UNICAST)
521                 return ieee80211_tx_h_unicast_ps_buf(tx);
522         else
523                 return ieee80211_tx_h_multicast_ps_buf(tx);
524 }
525 
526 static ieee80211_tx_result debug_noinline
527 ieee80211_tx_h_check_control_port_protocol(struct ieee80211_tx_data *tx)
528 {
529         struct ieee80211_tx_info *info = IEEE80211_SKB_CB(tx->skb);
530 
531         if (unlikely(tx->sdata->control_port_protocol == tx->skb->protocol &&
532                      tx->sdata->control_port_no_encrypt))
533                 info->flags |= IEEE80211_TX_INTFL_DONT_ENCRYPT;
534 
535         return TX_CONTINUE;
536 }
537 
538 static ieee80211_tx_result debug_noinline
539 ieee80211_tx_h_select_key(struct ieee80211_tx_data *tx)
540 {
541         struct ieee80211_key *key = NULL;
542         struct ieee80211_tx_info *info = IEEE80211_SKB_CB(tx->skb);
543         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)tx->skb->data;
544 
545         if (unlikely(info->flags & IEEE80211_TX_INTFL_DONT_ENCRYPT))
546                 tx->key = NULL;
547         else if (tx->sta && (key = rcu_dereference(tx->sta->ptk)))
548                 tx->key = key;
549         else if (ieee80211_is_mgmt(hdr->frame_control) &&
550                  is_multicast_ether_addr(hdr->addr1) &&
551                  ieee80211_is_robust_mgmt_frame(hdr) &&
552                  (key = rcu_dereference(tx->sdata->default_mgmt_key)))
553                 tx->key = key;
554         else if (is_multicast_ether_addr(hdr->addr1) &&
555                  (key = rcu_dereference(tx->sdata->default_multicast_key)))
556                 tx->key = key;
557         else if (!is_multicast_ether_addr(hdr->addr1) &&
558                  (key = rcu_dereference(tx->sdata->default_unicast_key)))
559                 tx->key = key;
560         else if (tx->sdata->drop_unencrypted &&
561                  (tx->skb->protocol != tx->sdata->control_port_protocol) &&
562                  !(info->flags & IEEE80211_TX_CTL_INJECTED) &&
563                  (!ieee80211_is_robust_mgmt_frame(hdr) ||
564                   (ieee80211_is_action(hdr->frame_control) &&
565                    tx->sta && test_sta_flag(tx->sta, WLAN_STA_MFP)))) {
566                 I802_DEBUG_INC(tx->local->tx_handlers_drop_unencrypted);
567                 return TX_DROP;
568         } else
569                 tx->key = NULL;
570 
571         if (tx->key) {
572                 bool skip_hw = false;
573 
574                 tx->key->tx_rx_count++;
575                 /* TODO: add threshold stuff again */
576 
577                 switch (tx->key->conf.cipher) {
578                 case WLAN_CIPHER_SUITE_WEP40:
579                 case WLAN_CIPHER_SUITE_WEP104:
580                 case WLAN_CIPHER_SUITE_TKIP:
581                         if (!ieee80211_is_data_present(hdr->frame_control))
582                                 tx->key = NULL;
583                         break;
584                 case WLAN_CIPHER_SUITE_CCMP:
585                         if (!ieee80211_is_data_present(hdr->frame_control) &&
586                             !ieee80211_use_mfp(hdr->frame_control, tx->sta,
587                                                tx->skb))
588                                 tx->key = NULL;
589                         else
590                                 skip_hw = (tx->key->conf.flags &
591                                            IEEE80211_KEY_FLAG_SW_MGMT) &&
592                                         ieee80211_is_mgmt(hdr->frame_control);
593                         break;
594                 case WLAN_CIPHER_SUITE_AES_CMAC:
595                         if (!ieee80211_is_mgmt(hdr->frame_control))
596                                 tx->key = NULL;
597                         break;
598                 }
599 
600                 if (unlikely(tx->key && tx->key->flags & KEY_FLAG_TAINTED))
601                         return TX_DROP;
602 
603                 if (!skip_hw && tx->key &&
604                     tx->key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE)
605                         info->control.hw_key = &tx->key->conf;
606         }
607 
608         return TX_CONTINUE;
609 }
610 
611 static ieee80211_tx_result debug_noinline
612 ieee80211_tx_h_rate_ctrl(struct ieee80211_tx_data *tx)
613 {
614         struct ieee80211_tx_info *info = IEEE80211_SKB_CB(tx->skb);
615         struct ieee80211_hdr *hdr = (void *)tx->skb->data;
616         struct ieee80211_supported_band *sband;
617         struct ieee80211_rate *rate;
618         int i;
619         u32 len;
620         bool inval = false, rts = false, short_preamble = false;
621         struct ieee80211_tx_rate_control txrc;
622         bool assoc = false;
623 
624         memset(&txrc, 0, sizeof(txrc));
625 
626         sband = tx->local->hw.wiphy->bands[tx->channel->band];
627 
628         len = min_t(u32, tx->skb->len + FCS_LEN,
629                          tx->local->hw.wiphy->frag_threshold);
630 
631         /* set up the tx rate control struct we give the RC algo */
632         txrc.hw = &tx->local->hw;
633         txrc.sband = sband;
634         txrc.bss_conf = &tx->sdata->vif.bss_conf;
635         txrc.skb = tx->skb;
636         txrc.reported_rate.idx = -1;
637         txrc.rate_idx_mask = tx->sdata->rc_rateidx_mask[tx->channel->band];
638         if (txrc.rate_idx_mask == (1 << sband->n_bitrates) - 1)
639                 txrc.max_rate_idx = -1;
640         else
641                 txrc.max_rate_idx = fls(txrc.rate_idx_mask) - 1;
642         memcpy(txrc.rate_idx_mcs_mask,
643                tx->sdata->rc_rateidx_mcs_mask[tx->channel->band],
644                sizeof(txrc.rate_idx_mcs_mask));
645         txrc.bss = (tx->sdata->vif.type == NL80211_IFTYPE_AP ||
646                     tx->sdata->vif.type == NL80211_IFTYPE_MESH_POINT ||
647                     tx->sdata->vif.type == NL80211_IFTYPE_ADHOC);
648 
649         /* set up RTS protection if desired */
650         if (len > tx->local->hw.wiphy->rts_threshold) {
651                 txrc.rts = rts = true;
652         }
653 
654         /*
655          * Use short preamble if the BSS can handle it, but not for
656          * management frames unless we know the receiver can handle
657          * that -- the management frame might be to a station that
658          * just wants a probe response.
659          */
660         if (tx->sdata->vif.bss_conf.use_short_preamble &&
661             (ieee80211_is_data(hdr->frame_control) ||
662              (tx->sta && test_sta_flag(tx->sta, WLAN_STA_SHORT_PREAMBLE))))
663                 txrc.short_preamble = short_preamble = true;
664 
665         if (tx->sta)
666                 assoc = test_sta_flag(tx->sta, WLAN_STA_ASSOC);
667 
668         /*
669          * Lets not bother rate control if we're associated and cannot
670          * talk to the sta. This should not happen.
671          */
672         if (WARN(test_bit(SCAN_SW_SCANNING, &tx->local->scanning) && assoc &&
673                  !rate_usable_index_exists(sband, &tx->sta->sta),
674                  "%s: Dropped data frame as no usable bitrate found while "
675                  "scanning and associated. Target station: "
676                  "%pM on %d GHz band\n",
677                  tx->sdata->name, hdr->addr1,
678                  tx->channel->band ? 5 : 2))
679                 return TX_DROP;
680 
681         /*
682          * If we're associated with the sta at this point we know we can at
683          * least send the frame at the lowest bit rate.
684          */
685         rate_control_get_rate(tx->sdata, tx->sta, &txrc);
686 
687         if (unlikely(info->control.rates[0].idx < 0))
688                 return TX_DROP;
689 
690         if (txrc.reported_rate.idx < 0) {
691                 txrc.reported_rate = info->control.rates[0];
692                 if (tx->sta && ieee80211_is_data(hdr->frame_control))
693                         tx->sta->last_tx_rate = txrc.reported_rate;
694         } else if (tx->sta)
695                 tx->sta->last_tx_rate = txrc.reported_rate;
696 
697         if (unlikely(!info->control.rates[0].count))
698                 info->control.rates[0].count = 1;
699 
700         if (WARN_ON_ONCE((info->control.rates[0].count > 1) &&
701                          (info->flags & IEEE80211_TX_CTL_NO_ACK)))
702                 info->control.rates[0].count = 1;
703 
704         if (is_multicast_ether_addr(hdr->addr1)) {
705                 /*
706                  * XXX: verify the rate is in the basic rateset
707                  */
708                 return TX_CONTINUE;
709         }
710 
711         /*
712          * set up the RTS/CTS rate as the fastest basic rate
713          * that is not faster than the data rate
714          *
715          * XXX: Should this check all retry rates?
716          */
717         if (!(info->control.rates[0].flags & IEEE80211_TX_RC_MCS)) {
718                 s8 baserate = 0;
719 
720                 rate = &sband->bitrates[info->control.rates[0].idx];
721 
722                 for (i = 0; i < sband->n_bitrates; i++) {
723                         /* must be a basic rate */
724                         if (!(tx->sdata->vif.bss_conf.basic_rates & BIT(i)))
725                                 continue;
726                         /* must not be faster than the data rate */
727                         if (sband->bitrates[i].bitrate > rate->bitrate)
728                                 continue;
729                         /* maximum */
730                         if (sband->bitrates[baserate].bitrate <
731                              sband->bitrates[i].bitrate)
732                                 baserate = i;
733                 }
734 
735                 info->control.rts_cts_rate_idx = baserate;
736         }
737 
738         for (i = 0; i < IEEE80211_TX_MAX_RATES; i++) {
739                 /*
740                  * make sure there's no valid rate following
741                  * an invalid one, just in case drivers don't
742                  * take the API seriously to stop at -1.
743                  */
744                 if (inval) {
745                         info->control.rates[i].idx = -1;
746                         continue;
747                 }
748                 if (info->control.rates[i].idx < 0) {
749                         inval = true;
750                         continue;
751                 }
752 
753                 /*
754                  * For now assume MCS is already set up correctly, this
755                  * needs to be fixed.
756                  */
757                 if (info->control.rates[i].flags & IEEE80211_TX_RC_MCS) {
758                         WARN_ON(info->control.rates[i].idx > 76);
759                         continue;
760                 }
761 
762                 /* set up RTS protection if desired */
763                 if (rts)
764                         info->control.rates[i].flags |=
765                                 IEEE80211_TX_RC_USE_RTS_CTS;
766 
767                 /* RC is busted */
768                 if (WARN_ON_ONCE(info->control.rates[i].idx >=
769                                  sband->n_bitrates)) {
770                         info->control.rates[i].idx = -1;
771                         continue;
772                 }
773 
774                 rate = &sband->bitrates[info->control.rates[i].idx];
775 
776                 /* set up short preamble */
777                 if (short_preamble &&
778                     rate->flags & IEEE80211_RATE_SHORT_PREAMBLE)
779                         info->control.rates[i].flags |=
780                                 IEEE80211_TX_RC_USE_SHORT_PREAMBLE;
781 
782                 /* set up G protection */
783                 if (!rts && tx->sdata->vif.bss_conf.use_cts_prot &&
784                     rate->flags & IEEE80211_RATE_ERP_G)
785                         info->control.rates[i].flags |=
786                                 IEEE80211_TX_RC_USE_CTS_PROTECT;
787         }
788 
789         return TX_CONTINUE;
790 }
791 
792 static ieee80211_tx_result debug_noinline
793 ieee80211_tx_h_sequence(struct ieee80211_tx_data *tx)
794 {
795         struct ieee80211_tx_info *info = IEEE80211_SKB_CB(tx->skb);
796         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)tx->skb->data;
797         u16 *seq;
798         u8 *qc;
799         int tid;
800 
801         /*
802          * Packet injection may want to control the sequence
803          * number, if we have no matching interface then we
804          * neither assign one ourselves nor ask the driver to.
805          */
806         if (unlikely(info->control.vif->type == NL80211_IFTYPE_MONITOR))
807                 return TX_CONTINUE;
808 
809         if (unlikely(ieee80211_is_ctl(hdr->frame_control)))
810                 return TX_CONTINUE;
811 
812         if (ieee80211_hdrlen(hdr->frame_control) < 24)
813                 return TX_CONTINUE;
814 
815         if (ieee80211_is_qos_nullfunc(hdr->frame_control))
816                 return TX_CONTINUE;
817 
818         /*
819          * Anything but QoS data that has a sequence number field
820          * (is long enough) gets a sequence number from the global
821          * counter.
822          */
823         if (!ieee80211_is_data_qos(hdr->frame_control)) {
824                 /* driver should assign sequence number */
825                 info->flags |= IEEE80211_TX_CTL_ASSIGN_SEQ;
826                 /* for pure STA mode without beacons, we can do it */
827                 hdr->seq_ctrl = cpu_to_le16(tx->sdata->sequence_number);
828                 tx->sdata->sequence_number += 0x10;
829                 return TX_CONTINUE;
830         }
831 
832         /*
833          * This should be true for injected/management frames only, for
834          * management frames we have set the IEEE80211_TX_CTL_ASSIGN_SEQ
835          * above since they are not QoS-data frames.
836          */
837         if (!tx->sta)
838                 return TX_CONTINUE;
839 
840         /* include per-STA, per-TID sequence counter */
841 
842         qc = ieee80211_get_qos_ctl(hdr);
843         tid = *qc & IEEE80211_QOS_CTL_TID_MASK;
844         seq = &tx->sta->tid_seq[tid];
845 
846         hdr->seq_ctrl = cpu_to_le16(*seq);
847 
848         /* Increase the sequence number. */
849         *seq = (*seq + 0x10) & IEEE80211_SCTL_SEQ;
850 
851         return TX_CONTINUE;
852 }
853 
854 static int ieee80211_fragment(struct ieee80211_tx_data *tx,
855                               struct sk_buff *skb, int hdrlen,
856                               int frag_threshold)
857 {
858         struct ieee80211_local *local = tx->local;
859         struct ieee80211_tx_info *info;
860         struct sk_buff *tmp;
861         int per_fragm = frag_threshold - hdrlen - FCS_LEN;
862         int pos = hdrlen + per_fragm;
863         int rem = skb->len - hdrlen - per_fragm;
864 
865         if (WARN_ON(rem < 0))
866                 return -EINVAL;
867 
868         /* first fragment was already added to queue by caller */
869 
870         while (rem) {
871                 int fraglen = per_fragm;
872 
873                 if (fraglen > rem)
874                         fraglen = rem;
875                 rem -= fraglen;
876                 tmp = dev_alloc_skb(local->tx_headroom +
877                                     frag_threshold +
878                                     IEEE80211_ENCRYPT_HEADROOM +
879                                     IEEE80211_ENCRYPT_TAILROOM);
880                 if (!tmp)
881                         return -ENOMEM;
882 
883                 __skb_queue_tail(&tx->skbs, tmp);
884 
885                 skb_reserve(tmp, local->tx_headroom +
886                                  IEEE80211_ENCRYPT_HEADROOM);
887                 /* copy control information */
888                 memcpy(tmp->cb, skb->cb, sizeof(tmp->cb));
889 
890                 info = IEEE80211_SKB_CB(tmp);
891                 info->flags &= ~(IEEE80211_TX_CTL_CLEAR_PS_FILT |
892                                  IEEE80211_TX_CTL_FIRST_FRAGMENT);
893 
894                 if (rem)
895                         info->flags |= IEEE80211_TX_CTL_MORE_FRAMES;
896 
897                 skb_copy_queue_mapping(tmp, skb);
898                 tmp->priority = skb->priority;
899                 tmp->dev = skb->dev;
900 
901                 /* copy header and data */
902                 memcpy(skb_put(tmp, hdrlen), skb->data, hdrlen);
903                 memcpy(skb_put(tmp, fraglen), skb->data + pos, fraglen);
904 
905                 pos += fraglen;
906         }
907 
908         /* adjust first fragment's length */
909         skb->len = hdrlen + per_fragm;
910         return 0;
911 }
912 
913 static ieee80211_tx_result debug_noinline
914 ieee80211_tx_h_fragment(struct ieee80211_tx_data *tx)
915 {
916         struct sk_buff *skb = tx->skb;
917         struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
918         struct ieee80211_hdr *hdr = (void *)skb->data;
919         int frag_threshold = tx->local->hw.wiphy->frag_threshold;
920         int hdrlen;
921         int fragnum;
922 
923         /* no matter what happens, tx->skb moves to tx->skbs */
924         __skb_queue_tail(&tx->skbs, skb);
925         tx->skb = NULL;
926 
927         if (info->flags & IEEE80211_TX_CTL_DONTFRAG)
928                 return TX_CONTINUE;
929 
930         if (tx->local->ops->set_frag_threshold)
931                 return TX_CONTINUE;
932 
933         /*
934          * Warn when submitting a fragmented A-MPDU frame and drop it.
935          * This scenario is handled in ieee80211_tx_prepare but extra
936          * caution taken here as fragmented ampdu may cause Tx stop.
937          */
938         if (WARN_ON(info->flags & IEEE80211_TX_CTL_AMPDU))
939                 return TX_DROP;
940 
941         hdrlen = ieee80211_hdrlen(hdr->frame_control);
942 
943         /* internal error, why isn't DONTFRAG set? */
944         if (WARN_ON(skb->len + FCS_LEN <= frag_threshold))
945                 return TX_DROP;
946 
947         /*
948          * Now fragment the frame. This will allocate all the fragments and
949          * chain them (using skb as the first fragment) to skb->next.
950          * During transmission, we will remove the successfully transmitted
951          * fragments from this list. When the low-level driver rejects one
952          * of the fragments then we will simply pretend to accept the skb
953          * but store it away as pending.
954          */
955         if (ieee80211_fragment(tx, skb, hdrlen, frag_threshold))
956                 return TX_DROP;
957 
958         /* update duration/seq/flags of fragments */
959         fragnum = 0;
960 
961         skb_queue_walk(&tx->skbs, skb) {
962                 int next_len;
963                 const __le16 morefrags = cpu_to_le16(IEEE80211_FCTL_MOREFRAGS);
964 
965                 hdr = (void *)skb->data;
966                 info = IEEE80211_SKB_CB(skb);
967 
968                 if (!skb_queue_is_last(&tx->skbs, skb)) {
969                         hdr->frame_control |= morefrags;
970                         /*
971                          * No multi-rate retries for fragmented frames, that
972                          * would completely throw off the NAV at other STAs.
973                          */
974                         info->control.rates[1].idx = -1;
975                         info->control.rates[2].idx = -1;
976                         info->control.rates[3].idx = -1;
977                         info->control.rates[4].idx = -1;
978                         BUILD_BUG_ON(IEEE80211_TX_MAX_RATES != 5);
979                         info->flags &= ~IEEE80211_TX_CTL_RATE_CTRL_PROBE;
980                 } else {
981                         hdr->frame_control &= ~morefrags;
982                         next_len = 0;
983                 }
984                 hdr->seq_ctrl |= cpu_to_le16(fragnum & IEEE80211_SCTL_FRAG);
985                 fragnum++;
986         }
987 
988         return TX_CONTINUE;
989 }
990 
991 static ieee80211_tx_result debug_noinline
992 ieee80211_tx_h_stats(struct ieee80211_tx_data *tx)
993 {
994         struct sk_buff *skb;
995 
996         if (!tx->sta)
997                 return TX_CONTINUE;
998 
999         tx->sta->tx_packets++;
1000         skb_queue_walk(&tx->skbs, skb) {
1001                 tx->sta->tx_fragments++;
1002                 tx->sta->tx_bytes += skb->len;
1003         }
1004 
1005         return TX_CONTINUE;
1006 }
1007 
1008 static ieee80211_tx_result debug_noinline
1009 ieee80211_tx_h_encrypt(struct ieee80211_tx_data *tx)
1010 {
1011         if (!tx->key)
1012                 return TX_CONTINUE;
1013 
1014         switch (tx->key->conf.cipher) {
1015         case WLAN_CIPHER_SUITE_WEP40:
1016         case WLAN_CIPHER_SUITE_WEP104:
1017                 return ieee80211_crypto_wep_encrypt(tx);
1018         case WLAN_CIPHER_SUITE_TKIP:
1019                 return ieee80211_crypto_tkip_encrypt(tx);
1020         case WLAN_CIPHER_SUITE_CCMP:
1021                 return ieee80211_crypto_ccmp_encrypt(tx);
1022         case WLAN_CIPHER_SUITE_AES_CMAC:
1023                 return ieee80211_crypto_aes_cmac_encrypt(tx);
1024         default:
1025                 return ieee80211_crypto_hw_encrypt(tx);
1026         }
1027 
1028         return TX_DROP;
1029 }
1030 
1031 static ieee80211_tx_result debug_noinline
1032 ieee80211_tx_h_calculate_duration(struct ieee80211_tx_data *tx)
1033 {
1034         struct sk_buff *skb;
1035         struct ieee80211_hdr *hdr;
1036         int next_len;
1037         bool group_addr;
1038 
1039         skb_queue_walk(&tx->skbs, skb) {
1040                 hdr = (void *) skb->data;
1041                 if (unlikely(ieee80211_is_pspoll(hdr->frame_control)))
1042                         break; /* must not overwrite AID */
1043                 if (!skb_queue_is_last(&tx->skbs, skb)) {
1044                         struct sk_buff *next = skb_queue_next(&tx->skbs, skb);
1045                         next_len = next->len;
1046                 } else
1047                         next_len = 0;
1048                 group_addr = is_multicast_ether_addr(hdr->addr1);
1049 
1050                 hdr->duration_id =
1051                         ieee80211_duration(tx, skb, group_addr, next_len);
1052         }
1053 
1054         return TX_CONTINUE;
1055 }
1056 
1057 /* actual transmit path */
1058 
1059 static bool ieee80211_tx_prep_agg(struct ieee80211_tx_data *tx,
1060                                   struct sk_buff *skb,
1061                                   struct ieee80211_tx_info *info,
1062                                   struct tid_ampdu_tx *tid_tx,
1063                                   int tid)
1064 {
1065         bool queued = false;
1066         bool reset_agg_timer = false;
1067         struct sk_buff *purge_skb = NULL;
1068 
1069         if (test_bit(HT_AGG_STATE_OPERATIONAL, &tid_tx->state)) {
1070                 info->flags |= IEEE80211_TX_CTL_AMPDU;
1071                 reset_agg_timer = true;
1072         } else if (test_bit(HT_AGG_STATE_WANT_START, &tid_tx->state)) {
1073                 /*
1074                  * nothing -- this aggregation session is being started
1075                  * but that might still fail with the driver
1076                  */
1077         } else {
1078                 spin_lock(&tx->sta->lock);
1079                 /*
1080                  * Need to re-check now, because we may get here
1081                  *
1082                  *  1) in the window during which the setup is actually
1083                  *     already done, but not marked yet because not all
1084                  *     packets are spliced over to the driver pending
1085                  *     queue yet -- if this happened we acquire the lock
1086                  *     either before or after the splice happens, but
1087                  *     need to recheck which of these cases happened.
1088                  *
1089                  *  2) during session teardown, if the OPERATIONAL bit
1090                  *     was cleared due to the teardown but the pointer
1091                  *     hasn't been assigned NULL yet (or we loaded it
1092                  *     before it was assigned) -- in this case it may
1093                  *     now be NULL which means we should just let the
1094                  *     packet pass through because splicing the frames
1095                  *     back is already done.
1096                  */
1097                 tid_tx = rcu_dereference_protected_tid_tx(tx->sta, tid);
1098 
1099                 if (!tid_tx) {
1100                         /* do nothing, let packet pass through */
1101                 } else if (test_bit(HT_AGG_STATE_OPERATIONAL, &tid_tx->state)) {
1102                         info->flags |= IEEE80211_TX_CTL_AMPDU;
1103                         reset_agg_timer = true;
1104                 } else {
1105                         queued = true;
1106                         info->control.vif = &tx->sdata->vif;
1107                         info->flags |= IEEE80211_TX_INTFL_NEED_TXPROCESSING;
1108                         __skb_queue_tail(&tid_tx->pending, skb);
1109                         if (skb_queue_len(&tid_tx->pending) > STA_MAX_TX_BUFFER)
1110                                 purge_skb = __skb_dequeue(&tid_tx->pending);
1111                 }
1112                 spin_unlock(&tx->sta->lock);
1113 
1114                 if (purge_skb)
1115                         dev_kfree_skb(purge_skb);
1116         }
1117 
1118         /* reset session timer */
1119         if (reset_agg_timer && tid_tx->timeout)
1120                 tid_tx->last_tx = jiffies;
1121 
1122         return queued;
1123 }
1124 
1125 /*
1126  * initialises @tx
1127  */
1128 static ieee80211_tx_result
1129 ieee80211_tx_prepare(struct ieee80211_sub_if_data *sdata,
1130                      struct ieee80211_tx_data *tx,
1131                      struct sk_buff *skb)
1132 {
1133         struct ieee80211_local *local = sdata->local;
1134         struct ieee80211_hdr *hdr;
1135         struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
1136         int tid;
1137         u8 *qc;
1138 
1139         memset(tx, 0, sizeof(*tx));
1140         tx->skb = skb;
1141         tx->local = local;
1142         tx->sdata = sdata;
1143         tx->channel = local->hw.conf.channel;
1144         __skb_queue_head_init(&tx->skbs);
1145 
1146         /*
1147          * If this flag is set to true anywhere, and we get here,
1148          * we are doing the needed processing, so remove the flag
1149          * now.
1150          */
1151         info->flags &= ~IEEE80211_TX_INTFL_NEED_TXPROCESSING;
1152 
1153         hdr = (struct ieee80211_hdr *) skb->data;
1154 
1155         if (sdata->vif.type == NL80211_IFTYPE_AP_VLAN) {
1156                 tx->sta = rcu_dereference(sdata->u.vlan.sta);
1157                 if (!tx->sta && sdata->dev->ieee80211_ptr->use_4addr)
1158                         return TX_DROP;
1159         } else if (info->flags & IEEE80211_TX_CTL_INJECTED ||
1160                    tx->sdata->control_port_protocol == tx->skb->protocol) {
1161                 tx->sta = sta_info_get_bss(sdata, hdr->addr1);
1162         }
1163         if (!tx->sta)
1164                 tx->sta = sta_info_get(sdata, hdr->addr1);
1165 
1166         if (tx->sta && ieee80211_is_data_qos(hdr->frame_control) &&
1167             !ieee80211_is_qos_nullfunc(hdr->frame_control) &&
1168             (local->hw.flags & IEEE80211_HW_AMPDU_AGGREGATION) &&
1169             !(local->hw.flags & IEEE80211_HW_TX_AMPDU_SETUP_IN_HW)) {
1170                 struct tid_ampdu_tx *tid_tx;
1171 
1172                 qc = ieee80211_get_qos_ctl(hdr);
1173                 tid = *qc & IEEE80211_QOS_CTL_TID_MASK;
1174 
1175                 tid_tx = rcu_dereference(tx->sta->ampdu_mlme.tid_tx[tid]);
1176                 if (tid_tx) {
1177                         bool queued;
1178 
1179                         queued = ieee80211_tx_prep_agg(tx, skb, info,
1180                                                        tid_tx, tid);
1181 
1182                         if (unlikely(queued))
1183                                 return TX_QUEUED;
1184                 }
1185         }
1186 
1187         if (is_multicast_ether_addr(hdr->addr1)) {
1188                 tx->flags &= ~IEEE80211_TX_UNICAST;
1189                 info->flags |= IEEE80211_TX_CTL_NO_ACK;
1190         } else
1191                 tx->flags |= IEEE80211_TX_UNICAST;
1192 
1193         if (!(info->flags & IEEE80211_TX_CTL_DONTFRAG)) {
1194                 if (!(tx->flags & IEEE80211_TX_UNICAST) ||
1195                     skb->len + FCS_LEN <= local->hw.wiphy->frag_threshold ||
1196                     info->flags & IEEE80211_TX_CTL_AMPDU)
1197                         info->flags |= IEEE80211_TX_CTL_DONTFRAG;
1198         }
1199 
1200         if (!tx->sta)
1201                 info->flags |= IEEE80211_TX_CTL_CLEAR_PS_FILT;
1202         else if (test_and_clear_sta_flag(tx->sta, WLAN_STA_CLEAR_PS_FILT))
1203                 info->flags |= IEEE80211_TX_CTL_CLEAR_PS_FILT;
1204 
1205         info->flags |= IEEE80211_TX_CTL_FIRST_FRAGMENT;
1206 
1207         return TX_CONTINUE;
1208 }
1209 
1210 static bool ieee80211_tx_frags(struct ieee80211_local *local,
1211                                struct ieee80211_vif *vif,
1212                                struct ieee80211_sta *sta,
1213                                struct sk_buff_head *skbs,
1214                                bool txpending)
1215 {
1216         struct sk_buff *skb, *tmp;
1217         unsigned long flags;
1218 
1219         skb_queue_walk_safe(skbs, skb, tmp) {
1220                 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
1221                 int q = info->hw_queue;
1222 
1223 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG
1224                 if (WARN_ON_ONCE(q >= local->hw.queues)) {
1225                         __skb_unlink(skb, skbs);
1226                         dev_kfree_skb(skb);
1227                         continue;
1228                 }
1229 #endif
1230 
1231                 spin_lock_irqsave(&local->queue_stop_reason_lock, flags);
1232                 if (local->queue_stop_reasons[q] ||
1233                     (!txpending && !skb_queue_empty(&local->pending[q]))) {
1234                         /*
1235                          * Since queue is stopped, queue up frames for later
1236                          * transmission from the tx-pending tasklet when the
1237                          * queue is woken again.
1238                          */
1239                         if (txpending)
1240                                 skb_queue_splice_init(skbs, &local->pending[q]);
1241                         else
1242                                 skb_queue_splice_tail_init(skbs,
1243                                                            &local->pending[q]);
1244 
1245                         spin_unlock_irqrestore(&local->queue_stop_reason_lock,
1246                                                flags);
1247                         return false;
1248                 }
1249                 spin_unlock_irqrestore(&local->queue_stop_reason_lock, flags);
1250 
1251                 info->control.vif = vif;
1252                 info->control.sta = sta;
1253 
1254                 __skb_unlink(skb, skbs);
1255                 drv_tx(local, skb);
1256         }
1257 
1258         return true;
1259 }
1260 
1261 /*
1262  * Returns false if the frame couldn't be transmitted but was queued instead.
1263  */
1264 static bool __ieee80211_tx(struct ieee80211_local *local,
1265                            struct sk_buff_head *skbs, int led_len,
1266                            struct sta_info *sta, bool txpending)
1267 {
1268         struct ieee80211_tx_info *info;
1269         struct ieee80211_sub_if_data *sdata;
1270         struct ieee80211_vif *vif;
1271         struct ieee80211_sta *pubsta;
1272         struct sk_buff *skb;
1273         bool result = true;
1274         __le16 fc;
1275 
1276         if (WARN_ON(skb_queue_empty(skbs)))
1277                 return true;
1278 
1279         skb = skb_peek(skbs);
1280         fc = ((struct ieee80211_hdr *)skb->data)->frame_control;
1281         info = IEEE80211_SKB_CB(skb);
1282         sdata = vif_to_sdata(info->control.vif);
1283         if (sta && !sta->uploaded)
1284                 sta = NULL;
1285 
1286         if (sta)
1287                 pubsta = &sta->sta;
1288         else
1289                 pubsta = NULL;
1290 
1291         switch (sdata->vif.type) {
1292         case NL80211_IFTYPE_MONITOR:
1293                 sdata = rcu_dereference(local->monitor_sdata);
1294                 if (sdata) {
1295                         vif = &sdata->vif;
1296                         info->hw_queue =
1297                                 vif->hw_queue[skb_get_queue_mapping(skb)];
1298                 } else if (local->hw.flags & IEEE80211_HW_QUEUE_CONTROL) {
1299                         dev_kfree_skb(skb);
1300                         return true;
1301                 } else
1302                         vif = NULL;
1303                 break;
1304         case NL80211_IFTYPE_AP_VLAN:
1305                 sdata = container_of(sdata->bss,
1306                                      struct ieee80211_sub_if_data, u.ap);
1307                 /* fall through */
1308         default:
1309                 vif = &sdata->vif;
1310                 break;
1311         }
1312 
1313         if (local->ops->tx_frags)
1314                 drv_tx_frags(local, vif, pubsta, skbs);
1315         else
1316                 result = ieee80211_tx_frags(local, vif, pubsta, skbs,
1317                                             txpending);
1318 
1319         ieee80211_tpt_led_trig_tx(local, fc, led_len);
1320         ieee80211_led_tx(local, 1);
1321 
1322         WARN_ON_ONCE(!skb_queue_empty(skbs));
1323 
1324         return result;
1325 }
1326 
1327 /*
1328  * Invoke TX handlers, return 0 on success and non-zero if the
1329  * frame was dropped or queued.
1330  */
1331 static int invoke_tx_handlers(struct ieee80211_tx_data *tx)
1332 {
1333         struct ieee80211_tx_info *info = IEEE80211_SKB_CB(tx->skb);
1334         ieee80211_tx_result res = TX_DROP;
1335 
1336 #define CALL_TXH(txh) \
1337         do {                            \
1338                 res = txh(tx);          \
1339                 if (res != TX_CONTINUE) \
1340                         goto txh_done;  \
1341         } while (0)
1342 
1343         CALL_TXH(ieee80211_tx_h_dynamic_ps);
1344         CALL_TXH(ieee80211_tx_h_check_assoc);
1345         CALL_TXH(ieee80211_tx_h_ps_buf);
1346         CALL_TXH(ieee80211_tx_h_check_control_port_protocol);
1347         CALL_TXH(ieee80211_tx_h_select_key);
1348         if (!(tx->local->hw.flags & IEEE80211_HW_HAS_RATE_CONTROL))
1349                 CALL_TXH(ieee80211_tx_h_rate_ctrl);
1350 
1351         if (unlikely(info->flags & IEEE80211_TX_INTFL_RETRANSMISSION)) {
1352                 __skb_queue_tail(&tx->skbs, tx->skb);
1353                 tx->skb = NULL;
1354                 goto txh_done;
1355         }
1356 
1357         CALL_TXH(ieee80211_tx_h_michael_mic_add);
1358         CALL_TXH(ieee80211_tx_h_sequence);
1359         CALL_TXH(ieee80211_tx_h_fragment);
1360         /* handlers after fragment must be aware of tx info fragmentation! */
1361         CALL_TXH(ieee80211_tx_h_stats);
1362         CALL_TXH(ieee80211_tx_h_encrypt);
1363         if (!(tx->local->hw.flags & IEEE80211_HW_HAS_RATE_CONTROL))
1364                 CALL_TXH(ieee80211_tx_h_calculate_duration);
1365 #undef CALL_TXH
1366 
1367  txh_done:
1368         if (unlikely(res == TX_DROP)) {
1369                 I802_DEBUG_INC(tx->local->tx_handlers_drop);
1370                 if (tx->skb)
1371                         dev_kfree_skb(tx->skb);
1372                 else
1373                         __skb_queue_purge(&tx->skbs);
1374                 return -1;
1375         } else if (unlikely(res == TX_QUEUED)) {
1376                 I802_DEBUG_INC(tx->local->tx_handlers_queued);
1377                 return -1;
1378         }
1379 
1380         return 0;
1381 }
1382 
1383 /*
1384  * Returns false if the frame couldn't be transmitted but was queued instead.
1385  */
1386 static bool ieee80211_tx(struct ieee80211_sub_if_data *sdata,
1387                          struct sk_buff *skb, bool txpending)
1388 {
1389         struct ieee80211_local *local = sdata->local;
1390         struct ieee80211_tx_data tx;
1391         ieee80211_tx_result res_prepare;
1392         struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
1393         bool result = true;
1394         int led_len;
1395 
1396         if (unlikely(skb->len < 10)) {
1397                 dev_kfree_skb(skb);
1398                 return true;
1399         }
1400 
1401         rcu_read_lock();
1402 
1403         /* initialises tx */
1404         led_len = skb->len;
1405         res_prepare = ieee80211_tx_prepare(sdata, &tx, skb);
1406 
1407         if (unlikely(res_prepare == TX_DROP)) {
1408                 dev_kfree_skb(skb);
1409                 goto out;
1410         } else if (unlikely(res_prepare == TX_QUEUED)) {
1411                 goto out;
1412         }
1413 
1414         tx.channel = local->hw.conf.channel;
1415         info->band = tx.channel->band;
1416 
1417         /* set up hw_queue value early */
1418         if (!(info->flags & IEEE80211_TX_CTL_TX_OFFCHAN) ||
1419             !(local->hw.flags & IEEE80211_HW_QUEUE_CONTROL))
1420                 info->hw_queue =
1421                         sdata->vif.hw_queue[skb_get_queue_mapping(skb)];
1422 
1423         if (!invoke_tx_handlers(&tx))
1424                 result = __ieee80211_tx(local, &tx.skbs, led_len,
1425                                         tx.sta, txpending);
1426  out:
1427         rcu_read_unlock();
1428         return result;
1429 }
1430 
1431 /* device xmit handlers */
1432 
1433 static int ieee80211_skb_resize(struct ieee80211_sub_if_data *sdata,
1434                                 struct sk_buff *skb,
1435                                 int head_need, bool may_encrypt)
1436 {
1437         struct ieee80211_local *local = sdata->local;
1438         int tail_need = 0;
1439 
1440         if (may_encrypt && sdata->crypto_tx_tailroom_needed_cnt) {
1441                 tail_need = IEEE80211_ENCRYPT_TAILROOM;
1442                 tail_need -= skb_tailroom(skb);
1443                 tail_need = max_t(int, tail_need, 0);
1444         }
1445 
1446         if (skb_cloned(skb))
1447                 I802_DEBUG_INC(local->tx_expand_skb_head_cloned);
1448         else if (head_need || tail_need)
1449                 I802_DEBUG_INC(local->tx_expand_skb_head);
1450         else
1451                 return 0;
1452 
1453         if (pskb_expand_head(skb, head_need, tail_need, GFP_ATOMIC)) {
1454                 wiphy_debug(local->hw.wiphy,
1455                             "failed to reallocate TX buffer\n");
1456                 return -ENOMEM;
1457         }
1458 
1459         return 0;
1460 }
1461 
1462 void ieee80211_xmit(struct ieee80211_sub_if_data *sdata, struct sk_buff *skb)
1463 {
1464         struct ieee80211_local *local = sdata->local;
1465         struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
1466         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
1467         int headroom;
1468         bool may_encrypt;
1469 
1470         rcu_read_lock();
1471 
1472         may_encrypt = !(info->flags & IEEE80211_TX_INTFL_DONT_ENCRYPT);
1473 
1474         headroom = local->tx_headroom;
1475         if (may_encrypt)
1476                 headroom += IEEE80211_ENCRYPT_HEADROOM;
1477         headroom -= skb_headroom(skb);
1478         headroom = max_t(int, 0, headroom);
1479 
1480         if (ieee80211_skb_resize(sdata, skb, headroom, may_encrypt)) {
1481                 dev_kfree_skb(skb);
1482                 rcu_read_unlock();
1483                 return;
1484         }
1485 
1486         hdr = (struct ieee80211_hdr *) skb->data;
1487         info->control.vif = &sdata->vif;
1488 
1489         if (ieee80211_vif_is_mesh(&sdata->vif) &&
1490             ieee80211_is_data(hdr->frame_control) &&
1491             !is_multicast_ether_addr(hdr->addr1) &&
1492             mesh_nexthop_resolve(skb, sdata)) {
1493                 /* skb queued: don't free */
1494                 rcu_read_unlock();
1495                 return;
1496         }
1497 
1498         ieee80211_set_qos_hdr(sdata, skb);
1499         ieee80211_tx(sdata, skb, false);
1500         rcu_read_unlock();
1501 }
1502 
1503 static bool ieee80211_parse_tx_radiotap(struct sk_buff *skb)
1504 {
1505         struct ieee80211_radiotap_iterator iterator;
1506         struct ieee80211_radiotap_header *rthdr =
1507                 (struct ieee80211_radiotap_header *) skb->data;
1508         struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
1509         int ret = ieee80211_radiotap_iterator_init(&iterator, rthdr, skb->len,
1510                                                    NULL);
1511         u16 txflags;
1512 
1513         info->flags |= IEEE80211_TX_INTFL_DONT_ENCRYPT |
1514                        IEEE80211_TX_CTL_DONTFRAG;
1515 
1516         /*
1517          * for every radiotap entry that is present
1518          * (ieee80211_radiotap_iterator_next returns -ENOENT when no more
1519          * entries present, or -EINVAL on error)
1520          */
1521 
1522         while (!ret) {
1523                 ret = ieee80211_radiotap_iterator_next(&iterator);
1524 
1525                 if (ret)
1526                         continue;
1527 
1528                 /* see if this argument is something we can use */
1529                 switch (iterator.this_arg_index) {
1530                 /*
1531                  * You must take care when dereferencing iterator.this_arg
1532                  * for multibyte types... the pointer is not aligned.  Use
1533                  * get_unaligned((type *)iterator.this_arg) to dereference
1534                  * iterator.this_arg for type "type" safely on all arches.
1535                 */
1536                 case IEEE80211_RADIOTAP_FLAGS:
1537                         if (*iterator.this_arg & IEEE80211_RADIOTAP_F_FCS) {
1538                                 /*
1539                                  * this indicates that the skb we have been
1540                                  * handed has the 32-bit FCS CRC at the end...
1541                                  * we should react to that by snipping it off
1542                                  * because it will be recomputed and added
1543                                  * on transmission
1544                                  */
1545                                 if (skb->len < (iterator._max_length + FCS_LEN))
1546                                         return false;
1547 
1548                                 skb_trim(skb, skb->len - FCS_LEN);
1549                         }
1550                         if (*iterator.this_arg & IEEE80211_RADIOTAP_F_WEP)
1551                                 info->flags &= ~IEEE80211_TX_INTFL_DONT_ENCRYPT;
1552                         if (*iterator.this_arg & IEEE80211_RADIOTAP_F_FRAG)
1553                                 info->flags &= ~IEEE80211_TX_CTL_DONTFRAG;
1554                         break;
1555 
1556                 case IEEE80211_RADIOTAP_TX_FLAGS:
1557                         txflags = get_unaligned_le16(iterator.this_arg);
1558                         if (txflags & IEEE80211_RADIOTAP_F_TX_NOACK)
1559                                 info->flags |= IEEE80211_TX_CTL_NO_ACK;
1560                         break;
1561 
1562                 /*
1563                  * Please update the file
1564                  * Documentation/networking/mac80211-injection.txt
1565                  * when parsing new fields here.
1566                  */
1567 
1568                 default:
1569                         break;
1570                 }
1571         }
1572 
1573         if (ret != -ENOENT) /* ie, if we didn't simply run out of fields */
1574                 return false;
1575 
1576         /*
1577          * remove the radiotap header
1578          * iterator->_max_length was sanity-checked against
1579          * skb->len by iterator init
1580          */
1581         skb_pull(skb, iterator._max_length);
1582 
1583         return true;
1584 }
1585 
1586 netdev_tx_t ieee80211_monitor_start_xmit(struct sk_buff *skb,
1587                                          struct net_device *dev)
1588 {
1589         struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
1590         struct ieee80211_channel *chan = local->hw.conf.channel;
1591         struct ieee80211_radiotap_header *prthdr =
1592                 (struct ieee80211_radiotap_header *)skb->data;
1593         struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
1594         struct ieee80211_hdr *hdr;
1595         struct ieee80211_sub_if_data *tmp_sdata, *sdata;
1596         u16 len_rthdr;
1597         int hdrlen;
1598 
1599         /*
1600          * Frame injection is not allowed if beaconing is not allowed
1601          * or if we need radar detection. Beaconing is usually not allowed when
1602          * the mode or operation (Adhoc, AP, Mesh) does not support DFS.
1603          * Passive scan is also used in world regulatory domains where
1604          * your country is not known and as such it should be treated as
1605          * NO TX unless the channel is explicitly allowed in which case
1606          * your current regulatory domain would not have the passive scan
1607          * flag.
1608          *
1609          * Since AP mode uses monitor interfaces to inject/TX management
1610          * frames we can make AP mode the exception to this rule once it
1611          * supports radar detection as its implementation can deal with
1612          * radar detection by itself. We can do that later by adding a
1613          * monitor flag interfaces used for AP support.
1614          */
1615         if ((chan->flags & (IEEE80211_CHAN_NO_IBSS | IEEE80211_CHAN_RADAR |
1616              IEEE80211_CHAN_PASSIVE_SCAN)))
1617                 goto fail;
1618 
1619         /* check for not even having the fixed radiotap header part */
1620         if (unlikely(skb->len < sizeof(struct ieee80211_radiotap_header)))
1621                 goto fail; /* too short to be possibly valid */
1622 
1623         /* is it a header version we can trust to find length from? */
1624         if (unlikely(prthdr->it_version))
1625                 goto fail; /* only version 0 is supported */
1626 
1627         /* then there must be a radiotap header with a length we can use */
1628         len_rthdr = ieee80211_get_radiotap_len(skb->data);
1629 
1630         /* does the skb contain enough to deliver on the alleged length? */
1631         if (unlikely(skb->len < len_rthdr))
1632                 goto fail; /* skb too short for claimed rt header extent */
1633 
1634         /*
1635          * fix up the pointers accounting for the radiotap
1636          * header still being in there.  We are being given
1637          * a precooked IEEE80211 header so no need for
1638          * normal processing
1639          */
1640         skb_set_mac_header(skb, len_rthdr);
1641         /*
1642          * these are just fixed to the end of the rt area since we
1643          * don't have any better information and at this point, nobody cares
1644          */
1645         skb_set_network_header(skb, len_rthdr);
1646         skb_set_transport_header(skb, len_rthdr);
1647 
1648         if (skb->len < len_rthdr + 2)
1649                 goto fail;
1650 
1651         hdr = (struct ieee80211_hdr *)(skb->data + len_rthdr);
1652         hdrlen = ieee80211_hdrlen(hdr->frame_control);
1653 
1654         if (skb->len < len_rthdr + hdrlen)
1655                 goto fail;
1656 
1657         /*
1658          * Initialize skb->protocol if the injected frame is a data frame
1659          * carrying a rfc1042 header
1660          */
1661         if (ieee80211_is_data(hdr->frame_control) &&
1662             skb->len >= len_rthdr + hdrlen + sizeof(rfc1042_header) + 2) {
1663                 u8 *payload = (u8 *)hdr + hdrlen;
1664 
1665                 if (ether_addr_equal(payload, rfc1042_header))
1666                         skb->protocol = cpu_to_be16((payload[6] << 8) |
1667                                                     payload[7]);
1668         }
1669 
1670         memset(info, 0, sizeof(*info));
1671 
1672         info->flags = IEEE80211_TX_CTL_REQ_TX_STATUS |
1673                       IEEE80211_TX_CTL_INJECTED;
1674 
1675         /* process and remove the injection radiotap header */
1676         if (!ieee80211_parse_tx_radiotap(skb))
1677                 goto fail;
1678 
1679         rcu_read_lock();
1680 
1681         /*
1682          * We process outgoing injected frames that have a local address
1683          * we handle as though they are non-injected frames.
1684          * This code here isn't entirely correct, the local MAC address
1685          * isn't always enough to find the interface to use; for proper
1686          * VLAN/WDS support we will need a different mechanism (which
1687          * likely isn't going to be monitor interfaces).
1688          */
1689         sdata = IEEE80211_DEV_TO_SUB_IF(dev);
1690 
1691         list_for_each_entry_rcu(tmp_sdata, &local->interfaces, list) {
1692                 if (!ieee80211_sdata_running(tmp_sdata))
1693                         continue;
1694                 if (tmp_sdata->vif.type == NL80211_IFTYPE_MONITOR ||
1695                     tmp_sdata->vif.type == NL80211_IFTYPE_AP_VLAN ||
1696                     tmp_sdata->vif.type == NL80211_IFTYPE_WDS)
1697                         continue;
1698                 if (ether_addr_equal(tmp_sdata->vif.addr, hdr->addr2)) {
1699                         sdata = tmp_sdata;
1700                         break;
1701                 }
1702         }
1703 
1704         ieee80211_xmit(sdata, skb);
1705         rcu_read_unlock();
1706 
1707         return NETDEV_TX_OK;
1708 
1709 fail:
1710         dev_kfree_skb(skb);
1711         return NETDEV_TX_OK; /* meaning, we dealt with the skb */
1712 }
1713 
1714 /**
1715  * ieee80211_subif_start_xmit - netif start_xmit function for Ethernet-type
1716  * subinterfaces (wlan#, WDS, and VLAN interfaces)
1717  * @skb: packet to be sent
1718  * @dev: incoming interface
1719  *
1720  * Returns: 0 on success (and frees skb in this case) or 1 on failure (skb will
1721  * not be freed, and caller is responsible for either retrying later or freeing
1722  * skb).
1723  *
1724  * This function takes in an Ethernet header and encapsulates it with suitable
1725  * IEEE 802.11 header based on which interface the packet is coming in. The
1726  * encapsulated packet will then be passed to master interface, wlan#.11, for
1727  * transmission (through low-level driver).
1728  */
1729 netdev_tx_t ieee80211_subif_start_xmit(struct sk_buff *skb,
1730                                     struct net_device *dev)
1731 {
1732         struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
1733         struct ieee80211_local *local = sdata->local;
1734         struct ieee80211_tx_info *info;
1735         int ret = NETDEV_TX_BUSY, head_need;
1736         u16 ethertype, hdrlen,  meshhdrlen = 0;
1737         __le16 fc;
1738         struct ieee80211_hdr hdr;
1739         struct ieee80211s_hdr mesh_hdr __maybe_unused;
1740         struct mesh_path __maybe_unused *mppath = NULL, *mpath = NULL;
1741         const u8 *encaps_data;
1742         int encaps_len, skip_header_bytes;
1743         int nh_pos, h_pos;
1744         struct sta_info *sta = NULL;
1745         bool wme_sta = false, authorized = false, tdls_auth = false;
1746         bool tdls_direct = false;
1747         bool multicast;
1748         u32 info_flags = 0;
1749         u16 info_id = 0;
1750 
1751         if (unlikely(skb->len < ETH_HLEN)) {
1752                 ret = NETDEV_TX_OK;
1753                 goto fail;
1754         }
1755 
1756         /* convert Ethernet header to proper 802.11 header (based on
1757          * operation mode) */
1758         ethertype = (skb->data[12] << 8) | skb->data[13];
1759         fc = cpu_to_le16(IEEE80211_FTYPE_DATA | IEEE80211_STYPE_DATA);
1760 
1761         switch (sdata->vif.type) {
1762         case NL80211_IFTYPE_AP_VLAN:
1763                 rcu_read_lock();
1764                 sta = rcu_dereference(sdata->u.vlan.sta);
1765                 if (sta) {
1766                         fc |= cpu_to_le16(IEEE80211_FCTL_FROMDS | IEEE80211_FCTL_TODS);
1767                         /* RA TA DA SA */
1768                         memcpy(hdr.addr1, sta->sta.addr, ETH_ALEN);
1769                         memcpy(hdr.addr2, sdata->vif.addr, ETH_ALEN);
1770                         memcpy(hdr.addr3, skb->data, ETH_ALEN);
1771                         memcpy(hdr.addr4, skb->data + ETH_ALEN, ETH_ALEN);
1772                         hdrlen = 30;
1773                         authorized = test_sta_flag(sta, WLAN_STA_AUTHORIZED);
1774                         wme_sta = test_sta_flag(sta, WLAN_STA_WME);
1775                 }
1776                 rcu_read_unlock();
1777                 if (sta)
1778                         break;
1779                 /* fall through */
1780         case NL80211_IFTYPE_AP:
1781                 fc |= cpu_to_le16(IEEE80211_FCTL_FROMDS);
1782                 /* DA BSSID SA */
1783                 memcpy(hdr.addr1, skb->data, ETH_ALEN);
1784                 memcpy(hdr.addr2, sdata->vif.addr, ETH_ALEN);
1785                 memcpy(hdr.addr3, skb->data + ETH_ALEN, ETH_ALEN);
1786                 hdrlen = 24;
1787                 break;
1788         case NL80211_IFTYPE_WDS:
1789                 fc |= cpu_to_le16(IEEE80211_FCTL_FROMDS | IEEE80211_FCTL_TODS);
1790                 /* RA TA DA SA */
1791                 memcpy(hdr.addr1, sdata->u.wds.remote_addr, ETH_ALEN);
1792                 memcpy(hdr.addr2, sdata->vif.addr, ETH_ALEN);
1793                 memcpy(hdr.addr3, skb->data, ETH_ALEN);
1794                 memcpy(hdr.addr4, skb->data + ETH_ALEN, ETH_ALEN);
1795                 hdrlen = 30;
1796                 break;
1797 #ifdef CONFIG_MAC80211_MESH
1798         case NL80211_IFTYPE_MESH_POINT:
1799                 if (!sdata->u.mesh.mshcfg.dot11MeshTTL) {
1800                         /* Do not send frames with mesh_ttl == 0 */
1801                         sdata->u.mesh.mshstats.dropped_frames_ttl++;
1802                         ret = NETDEV_TX_OK;
1803                         goto fail;
1804                 }
1805                 rcu_read_lock();
1806                 if (!is_multicast_ether_addr(skb->data)) {
1807                         mpath = mesh_path_lookup(skb->data, sdata);
1808                         if (!mpath)
1809                                 mppath = mpp_path_lookup(skb->data, sdata);
1810                 }
1811 
1812                 /*
1813                  * Use address extension if it is a packet from
1814                  * another interface or if we know the destination
1815                  * is being proxied by a portal (i.e. portal address
1816                  * differs from proxied address)
1817                  */
1818                 if (ether_addr_equal(sdata->vif.addr, skb->data + ETH_ALEN) &&
1819                     !(mppath && !ether_addr_equal(mppath->mpp, skb->data))) {
1820                         hdrlen = ieee80211_fill_mesh_addresses(&hdr, &fc,
1821                                         skb->data, skb->data + ETH_ALEN);
1822                         rcu_read_unlock();
1823                         meshhdrlen = ieee80211_new_mesh_header(&mesh_hdr,
1824                                         sdata, NULL, NULL);
1825                 } else {
1826                         int is_mesh_mcast = 1;
1827                         const u8 *mesh_da;
1828 
1829                         if (is_multicast_ether_addr(skb->data))
1830                                 /* DA TA mSA AE:SA */
1831                                 mesh_da = skb->data;
1832                         else {
1833                                 static const u8 bcast[ETH_ALEN] =
1834                                         { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };
1835                                 if (mppath) {
1836                                         /* RA TA mDA mSA AE:DA SA */
1837                                         mesh_da = mppath->mpp;
1838                                         is_mesh_mcast = 0;
1839                                 } else {
1840                                         /* DA TA mSA AE:SA */
1841                                         mesh_da = bcast;
1842                                 }
1843                         }
1844                         hdrlen = ieee80211_fill_mesh_addresses(&hdr, &fc,
1845                                         mesh_da, sdata->vif.addr);
1846                         rcu_read_unlock();
1847                         if (is_mesh_mcast)
1848                                 meshhdrlen =
1849                                         ieee80211_new_mesh_header(&mesh_hdr,
1850                                                         sdata,
1851                                                         skb->data + ETH_ALEN,
1852                                                         NULL);
1853                         else
1854                                 meshhdrlen =
1855                                         ieee80211_new_mesh_header(&mesh_hdr,
1856                                                         sdata,
1857                                                         skb->data,
1858                                                         skb->data + ETH_ALEN);
1859 
1860                 }
1861                 break;
1862 #endif
1863         case NL80211_IFTYPE_STATION:
1864                 if (sdata->wdev.wiphy->flags & WIPHY_FLAG_SUPPORTS_TDLS) {
1865                         bool tdls_peer = false;
1866 
1867                         rcu_read_lock();
1868                         sta = sta_info_get(sdata, skb->data);
1869                         if (sta) {
1870                                 authorized = test_sta_flag(sta,
1871                                                         WLAN_STA_AUTHORIZED);
1872                                 wme_sta = test_sta_flag(sta, WLAN_STA_WME);
1873                                 tdls_peer = test_sta_flag(sta,
1874                                                          WLAN_STA_TDLS_PEER);
1875                                 tdls_auth = test_sta_flag(sta,
1876                                                 WLAN_STA_TDLS_PEER_AUTH);
1877                         }
1878                         rcu_read_unlock();
1879 
1880                         /*
1881                          * If the TDLS link is enabled, send everything
1882                          * directly. Otherwise, allow TDLS setup frames
1883                          * to be transmitted indirectly.
1884                          */
1885                         tdls_direct = tdls_peer && (tdls_auth ||
1886                                  !(ethertype == ETH_P_TDLS && skb->len > 14 &&
1887                                    skb->data[14] == WLAN_TDLS_SNAP_RFTYPE));
1888                 }
1889 
1890                 if (tdls_direct) {
1891                         /* link during setup - throw out frames to peer */
1892                         if (!tdls_auth) {
1893                                 ret = NETDEV_TX_OK;
1894                                 goto fail;
1895                         }
1896 
1897                         /* DA SA BSSID */
1898                         memcpy(hdr.addr1, skb->data, ETH_ALEN);
1899                         memcpy(hdr.addr2, skb->data + ETH_ALEN, ETH_ALEN);
1900                         memcpy(hdr.addr3, sdata->u.mgd.bssid, ETH_ALEN);
1901                         hdrlen = 24;
1902                 }  else if (sdata->u.mgd.use_4addr &&
1903                             cpu_to_be16(ethertype) != sdata->control_port_protocol) {
1904                         fc |= cpu_to_le16(IEEE80211_FCTL_FROMDS |
1905                                           IEEE80211_FCTL_TODS);
1906                         /* RA TA DA SA */
1907                         memcpy(hdr.addr1, sdata->u.mgd.bssid, ETH_ALEN);
1908                         memcpy(hdr.addr2, sdata->vif.addr, ETH_ALEN);
1909                         memcpy(hdr.addr3, skb->data, ETH_ALEN);
1910                         memcpy(hdr.addr4, skb->data + ETH_ALEN, ETH_ALEN);
1911                         hdrlen = 30;
1912                 } else {
1913                         fc |= cpu_to_le16(IEEE80211_FCTL_TODS);
1914                         /* BSSID SA DA */
1915                         memcpy(hdr.addr1, sdata->u.mgd.bssid, ETH_ALEN);
1916                         memcpy(hdr.addr2, skb->data + ETH_ALEN, ETH_ALEN);
1917                         memcpy(hdr.addr3, skb->data, ETH_ALEN);
1918                         hdrlen = 24;
1919                 }
1920                 break;
1921         case NL80211_IFTYPE_ADHOC:
1922                 /* DA SA BSSID */
1923                 memcpy(hdr.addr1, skb->data, ETH_ALEN);
1924                 memcpy(hdr.addr2, skb->data + ETH_ALEN, ETH_ALEN);
1925                 memcpy(hdr.addr3, sdata->u.ibss.bssid, ETH_ALEN);
1926                 hdrlen = 24;
1927                 break;
1928         default:
1929                 ret = NETDEV_TX_OK;
1930                 goto fail;
1931         }
1932 
1933         /*
1934          * There's no need to try to look up the destination
1935          * if it is a multicast address (which can only happen
1936          * in AP mode)
1937          */
1938         multicast = is_multicast_ether_addr(hdr.addr1);
1939         if (!multicast) {
1940                 rcu_read_lock();
1941                 sta = sta_info_get(sdata, hdr.addr1);
1942                 if (sta) {
1943                         authorized = test_sta_flag(sta, WLAN_STA_AUTHORIZED);
1944                         wme_sta = test_sta_flag(sta, WLAN_STA_WME);
1945                 }
1946                 rcu_read_unlock();
1947         }
1948 
1949         /* For mesh, the use of the QoS header is mandatory */
1950         if (ieee80211_vif_is_mesh(&sdata->vif))
1951                 wme_sta = true;
1952 
1953         /* receiver and we are QoS enabled, use a QoS type frame */
1954         if (wme_sta && local->hw.queues >= IEEE80211_NUM_ACS) {
1955                 fc |= cpu_to_le16(IEEE80211_STYPE_QOS_DATA);
1956                 hdrlen += 2;
1957         }
1958 
1959         /*
1960          * Drop unicast frames to unauthorised stations unless they are
1961          * EAPOL frames from the local station.
1962          */
1963         if (unlikely(!ieee80211_vif_is_mesh(&sdata->vif) &&
1964                      !is_multicast_ether_addr(hdr.addr1) && !authorized &&
1965                      (cpu_to_be16(ethertype) != sdata->control_port_protocol ||
1966                       !ether_addr_equal(sdata->vif.addr, skb->data + ETH_ALEN)))) {
1967 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG
1968                 net_dbg_ratelimited("%s: dropped frame to %pM (unauthorized port)\n",
1969                                     dev->name, hdr.addr1);
1970 #endif
1971 
1972                 I802_DEBUG_INC(local->tx_handlers_drop_unauth_port);
1973 
1974                 ret = NETDEV_TX_OK;
1975                 goto fail;
1976         }
1977 
1978         if (unlikely(!multicast && skb->sk &&
1979                      skb_shinfo(skb)->tx_flags & SKBTX_WIFI_STATUS)) {
1980                 struct sk_buff *orig_skb = skb;
1981 
1982                 skb = skb_clone(skb, GFP_ATOMIC);
1983                 if (skb) {
1984                         unsigned long flags;
1985                         int id, r;
1986 
1987                         spin_lock_irqsave(&local->ack_status_lock, flags);
1988                         r = idr_get_new_above(&local->ack_status_frames,
1989                                               orig_skb, 1, &id);
1990                         if (r == -EAGAIN) {
1991                                 idr_pre_get(&local->ack_status_frames,
1992                                             GFP_ATOMIC);
1993                                 r = idr_get_new_above(&local->ack_status_frames,
1994                                                       orig_skb, 1, &id);
1995                         }
1996                         if (WARN_ON(!id) || id > 0xffff) {
1997                                 idr_remove(&local->ack_status_frames, id);
1998                                 r = -ERANGE;
1999                         }
2000                         spin_unlock_irqrestore(&local->ack_status_lock, flags);
2001 
2002                         if (!r) {
2003                                 info_id = id;
2004                                 info_flags |= IEEE80211_TX_CTL_REQ_TX_STATUS;
2005                         } else if (skb_shared(skb)) {
2006                                 kfree_skb(orig_skb);
2007                         } else {
2008                                 kfree_skb(skb);
2009                                 skb = orig_skb;
2010                         }
2011                 } else {
2012                         /* couldn't clone -- lose tx status ... */
2013                         skb = orig_skb;
2014                 }
2015         }
2016 
2017         /*
2018          * If the skb is shared we need to obtain our own copy.
2019          */
2020         if (skb_shared(skb)) {
2021                 struct sk_buff *tmp_skb = skb;
2022 
2023                 /* can't happen -- skb is a clone if info_id != 0 */
2024                 WARN_ON(info_id);
2025 
2026                 skb = skb_clone(skb, GFP_ATOMIC);
2027                 kfree_skb(tmp_skb);
2028 
2029                 if (!skb) {
2030                         ret = NETDEV_TX_OK;
2031                         goto fail;
2032                 }
2033         }
2034 
2035         hdr.frame_control = fc;
2036         hdr.duration_id = 0;
2037         hdr.seq_ctrl = 0;
2038 
2039         skip_header_bytes = ETH_HLEN;
2040         if (ethertype == ETH_P_AARP || ethertype == ETH_P_IPX) {
2041                 encaps_data = bridge_tunnel_header;
2042                 encaps_len = sizeof(bridge_tunnel_header);
2043                 skip_header_bytes -= 2;
2044         } else if (ethertype >= 0x600) {
2045                 encaps_data = rfc1042_header;
2046                 encaps_len = sizeof(rfc1042_header);
2047                 skip_header_bytes -= 2;
2048         } else {
2049                 encaps_data = NULL;
2050                 encaps_len = 0;
2051         }
2052 
2053         nh_pos = skb_network_header(skb) - skb->data;
2054         h_pos = skb_transport_header(skb) - skb->data;
2055 
2056         skb_pull(skb, skip_header_bytes);
2057         nh_pos -= skip_header_bytes;
2058         h_pos -= skip_header_bytes;
2059 
2060         head_need = hdrlen + encaps_len + meshhdrlen - skb_headroom(skb);
2061 
2062         /*
2063          * So we need to modify the skb header and hence need a copy of
2064          * that. The head_need variable above doesn't, so far, include
2065          * the needed header space that we don't need right away. If we
2066          * can, then we don't reallocate right now but only after the
2067          * frame arrives at the master device (if it does...)
2068          *
2069          * If we cannot, however, then we will reallocate to include all
2070          * the ever needed space. Also, if we need to reallocate it anyway,
2071          * make it big enough for everything we may ever need.
2072          */
2073 
2074         if (head_need > 0 || skb_cloned(skb)) {
2075                 head_need += IEEE80211_ENCRYPT_HEADROOM;
2076                 head_need += local->tx_headroom;
2077                 head_need = max_t(int, 0, head_need);
2078                 if (ieee80211_skb_resize(sdata, skb, head_need, true))
2079                         goto fail;
2080         }
2081 
2082         if (encaps_data) {
2083                 memcpy(skb_push(skb, encaps_len), encaps_data, encaps_len);
2084                 nh_pos += encaps_len;
2085                 h_pos += encaps_len;
2086         }
2087 
2088 #ifdef CONFIG_MAC80211_MESH
2089         if (meshhdrlen > 0) {
2090                 memcpy(skb_push(skb, meshhdrlen), &mesh_hdr, meshhdrlen);
2091                 nh_pos += meshhdrlen;
2092                 h_pos += meshhdrlen;
2093         }
2094 #endif
2095 
2096         if (ieee80211_is_data_qos(fc)) {
2097                 __le16 *qos_control;
2098 
2099                 qos_control = (__le16*) skb_push(skb, 2);
2100                 memcpy(skb_push(skb, hdrlen - 2), &hdr, hdrlen - 2);
2101                 /*
2102                  * Maybe we could actually set some fields here, for now just
2103                  * initialise to zero to indicate no special operation.
2104                  */
2105                 *qos_control = 0;
2106         } else
2107                 memcpy(skb_push(skb, hdrlen), &hdr, hdrlen);
2108 
2109         nh_pos += hdrlen;
2110         h_pos += hdrlen;
2111 
2112         dev->stats.tx_packets++;
2113         dev->stats.tx_bytes += skb->len;
2114 
2115         /* Update skb pointers to various headers since this modified frame
2116          * is going to go through Linux networking code that may potentially
2117          * need things like pointer to IP header. */
2118         skb_set_mac_header(skb, 0);
2119         skb_set_network_header(skb, nh_pos);
2120         skb_set_transport_header(skb, h_pos);
2121 
2122         info = IEEE80211_SKB_CB(skb);
2123         memset(info, 0, sizeof(*info));
2124 
2125         dev->trans_start = jiffies;
2126 
2127         info->flags = info_flags;
2128         info->ack_frame_id = info_id;
2129 
2130         ieee80211_xmit(sdata, skb);
2131 
2132         return NETDEV_TX_OK;
2133 
2134  fail:
2135         if (ret == NETDEV_TX_OK)
2136                 dev_kfree_skb(skb);
2137 
2138         return ret;
2139 }
2140 
2141 
2142 /*
2143  * ieee80211_clear_tx_pending may not be called in a context where
2144  * it is possible that it packets could come in again.
2145  */
2146 void ieee80211_clear_tx_pending(struct ieee80211_local *local)
2147 {
2148         int i;
2149 
2150         for (i = 0; i < local->hw.queues; i++)
2151                 skb_queue_purge(&local->pending[i]);
2152 }
2153 
2154 /*
2155  * Returns false if the frame couldn't be transmitted but was queued instead,
2156  * which in this case means re-queued -- take as an indication to stop sending
2157  * more pending frames.
2158  */
2159 static bool ieee80211_tx_pending_skb(struct ieee80211_local *local,
2160                                      struct sk_buff *skb)
2161 {
2162         struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
2163         struct ieee80211_sub_if_data *sdata;
2164         struct sta_info *sta;
2165         struct ieee80211_hdr *hdr;
2166         bool result;
2167 
2168         sdata = vif_to_sdata(info->control.vif);
2169 
2170         if (info->flags & IEEE80211_TX_INTFL_NEED_TXPROCESSING) {
2171                 result = ieee80211_tx(sdata, skb, true);
2172         } else {
2173                 struct sk_buff_head skbs;
2174 
2175                 __skb_queue_head_init(&skbs);
2176                 __skb_queue_tail(&skbs, skb);
2177 
2178                 hdr = (struct ieee80211_hdr *)skb->data;
2179                 sta = sta_info_get(sdata, hdr->addr1);
2180 
2181                 result = __ieee80211_tx(local, &skbs, skb->len, sta, true);
2182         }
2183 
2184         return result;
2185 }
2186 
2187 /*
2188  * Transmit all pending packets. Called from tasklet.
2189  */
2190 void ieee80211_tx_pending(unsigned long data)
2191 {
2192         struct ieee80211_local *local = (struct ieee80211_local *)data;
2193         unsigned long flags;
2194         int i;
2195         bool txok;
2196 
2197         rcu_read_lock();
2198 
2199         spin_lock_irqsave(&local->queue_stop_reason_lock, flags);
2200         for (i = 0; i < local->hw.queues; i++) {
2201                 /*
2202                  * If queue is stopped by something other than due to pending
2203                  * frames, or we have no pending frames, proceed to next queue.
2204                  */
2205                 if (local->queue_stop_reasons[i] ||
2206                     skb_queue_empty(&local->pending[i]))
2207                         continue;
2208 
2209                 while (!skb_queue_empty(&local->pending[i])) {
2210                         struct sk_buff *skb = __skb_dequeue(&local->pending[i]);
2211                         struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
2212 
2213                         if (WARN_ON(!info->control.vif)) {
2214                                 kfree_skb(skb);
2215                                 continue;
2216                         }
2217 
2218                         spin_unlock_irqrestore(&local->queue_stop_reason_lock,
2219                                                 flags);
2220 
2221                         txok = ieee80211_tx_pending_skb(local, skb);
2222                         spin_lock_irqsave(&local->queue_stop_reason_lock,
2223                                           flags);
2224                         if (!txok)
2225                                 break;
2226                 }
2227 
2228                 if (skb_queue_empty(&local->pending[i]))
2229                         ieee80211_propagate_queue_wake(local, i);
2230         }
2231         spin_unlock_irqrestore(&local->queue_stop_reason_lock, flags);
2232 
2233         rcu_read_unlock();
2234 }
2235 
2236 /* functions for drivers to get certain frames */
2237 
2238 static void ieee80211_beacon_add_tim(struct ieee80211_sub_if_data *sdata,
2239                                      struct ieee80211_if_ap *bss,
2240                                      struct sk_buff *skb,
2241                                      struct beacon_data *beacon)
2242 {
2243         u8 *pos, *tim;
2244         int aid0 = 0;
2245         int i, have_bits = 0, n1, n2;
2246 
2247         /* Generate bitmap for TIM only if there are any STAs in power save
2248          * mode. */
2249         if (atomic_read(&bss->num_sta_ps) > 0)
2250                 /* in the hope that this is faster than
2251                  * checking byte-for-byte */
2252                 have_bits = !bitmap_empty((unsigned long*)bss->tim,
2253                                           IEEE80211_MAX_AID+1);
2254 
2255         if (bss->dtim_count == 0)
2256                 bss->dtim_count = sdata->vif.bss_conf.dtim_period - 1;
2257         else
2258                 bss->dtim_count--;
2259 
2260         tim = pos = (u8 *) skb_put(skb, 6);
2261         *pos++ = WLAN_EID_TIM;
2262         *pos++ = 4;
2263         *pos++ = bss->dtim_count;
2264         *pos++ = sdata->vif.bss_conf.dtim_period;
2265 
2266         if (bss->dtim_count == 0 && !skb_queue_empty(&bss->ps_bc_buf))
2267                 aid0 = 1;
2268 
2269         bss->dtim_bc_mc = aid0 == 1;
2270 
2271         if (have_bits) {
2272                 /* Find largest even number N1 so that bits numbered 1 through
2273                  * (N1 x 8) - 1 in the bitmap are 0 and number N2 so that bits
2274                  * (N2 + 1) x 8 through 2007 are 0. */
2275                 n1 = 0;
2276                 for (i = 0; i < IEEE80211_MAX_TIM_LEN; i++) {
2277                         if (bss->tim[i]) {
2278                                 n1 = i & 0xfe;
2279                                 break;
2280                         }
2281                 }
2282                 n2 = n1;
2283                 for (i = IEEE80211_MAX_TIM_LEN - 1; i >= n1; i--) {
2284                         if (bss->tim[i]) {
2285                                 n2 = i;
2286                                 break;
2287                         }
2288                 }
2289 
2290                 /* Bitmap control */
2291                 *pos++ = n1 | aid0;
2292                 /* Part Virt Bitmap */
2293                 skb_put(skb, n2 - n1);
2294                 memcpy(pos, bss->tim + n1, n2 - n1 + 1);
2295 
2296                 tim[1] = n2 - n1 + 4;
2297         } else {
2298                 *pos++ = aid0; /* Bitmap control */
2299                 *pos++ = 0; /* Part Virt Bitmap */
2300         }
2301 }
2302 
2303 struct sk_buff *ieee80211_beacon_get_tim(struct ieee80211_hw *hw,
2304                                          struct ieee80211_vif *vif,
2305                                          u16 *tim_offset, u16 *tim_length)
2306 {
2307         struct ieee80211_local *local = hw_to_local(hw);
2308         struct sk_buff *skb = NULL;
2309         struct ieee80211_tx_info *info;
2310         struct ieee80211_sub_if_data *sdata = NULL;
2311         struct ieee80211_if_ap *ap = NULL;
2312         struct beacon_data *beacon;
2313         struct ieee80211_supported_band *sband;
2314         enum ieee80211_band band = local->hw.conf.channel->band;
2315         struct ieee80211_tx_rate_control txrc;
2316 
2317         sband = local->hw.wiphy->bands[band];
2318 
2319         rcu_read_lock();
2320 
2321         sdata = vif_to_sdata(vif);
2322 
2323         if (!ieee80211_sdata_running(sdata))
2324                 goto out;
2325 
2326         if (tim_offset)
2327                 *tim_offset = 0;
2328         if (tim_length)
2329                 *tim_length = 0;
2330 
2331         if (sdata->vif.type == NL80211_IFTYPE_AP) {
2332                 ap = &sdata->u.ap;
2333                 beacon = rcu_dereference(ap->beacon);
2334                 if (beacon) {
2335                         /*
2336                          * headroom, head length,
2337                          * tail length and maximum TIM length
2338                          */
2339                         skb = dev_alloc_skb(local->tx_headroom +
2340                                             beacon->head_len +
2341                                             beacon->tail_len + 256);
2342                         if (!skb)
2343                                 goto out;
2344 
2345                         skb_reserve(skb, local->tx_headroom);
2346                         memcpy(skb_put(skb, beacon->head_len), beacon->head,
2347                                beacon->head_len);
2348 
2349                         /*
2350                          * Not very nice, but we want to allow the driver to call
2351                          * ieee80211_beacon_get() as a response to the set_tim()
2352                          * callback. That, however, is already invoked under the
2353                          * sta_lock to guarantee consistent and race-free update
2354                          * of the tim bitmap in mac80211 and the driver.
2355                          */
2356                         if (local->tim_in_locked_section) {
2357                                 ieee80211_beacon_add_tim(sdata, ap, skb,
2358                                                          beacon);
2359                         } else {
2360                                 unsigned long flags;
2361 
2362                                 spin_lock_irqsave(&local->tim_lock, flags);
2363                                 ieee80211_beacon_add_tim(sdata, ap, skb,
2364                                                          beacon);
2365                                 spin_unlock_irqrestore(&local->tim_lock, flags);
2366                         }
2367 
2368                         if (tim_offset)
2369                                 *tim_offset = beacon->head_len;
2370                         if (tim_length)
2371                                 *tim_length = skb->len - beacon->head_len;
2372 
2373                         if (beacon->tail)
2374                                 memcpy(skb_put(skb, beacon->tail_len),
2375                                        beacon->tail, beacon->tail_len);
2376                 } else
2377                         goto out;
2378         } else if (sdata->vif.type == NL80211_IFTYPE_ADHOC) {
2379                 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
2380                 struct ieee80211_hdr *hdr;
2381                 struct sk_buff *presp = rcu_dereference(ifibss->presp);
2382 
2383                 if (!presp)
2384                         goto out;
2385 
2386                 skb = skb_copy(presp, GFP_ATOMIC);
2387                 if (!skb)
2388                         goto out;
2389 
2390                 hdr = (struct ieee80211_hdr *) skb->data;
2391                 hdr->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
2392                                                  IEEE80211_STYPE_BEACON);
2393         } else if (ieee80211_vif_is_mesh(&sdata->vif)) {
2394                 struct ieee80211_mgmt *mgmt;
2395                 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
2396                 u8 *pos;
2397                 int hdr_len = offsetof(struct ieee80211_mgmt, u.beacon) +
2398                               sizeof(mgmt->u.beacon);
2399 
2400 #ifdef CONFIG_MAC80211_MESH
2401                 if (!sdata->u.mesh.mesh_id_len)
2402                         goto out;
2403 #endif
2404 
2405                 if (ifmsh->sync_ops)
2406                         ifmsh->sync_ops->adjust_tbtt(
2407                                                 sdata);
2408 
2409                 skb = dev_alloc_skb(local->tx_headroom +
2410                                     hdr_len +
2411                                     2 + /* NULL SSID */
2412                                     2 + 8 + /* supported rates */
2413                                     2 + 3 + /* DS params */
2414                                     2 + (IEEE80211_MAX_SUPP_RATES - 8) +
2415                                     2 + sizeof(struct ieee80211_ht_cap) +
2416                                     2 + sizeof(struct ieee80211_ht_operation) +
2417                                     2 + sdata->u.mesh.mesh_id_len +
2418                                     2 + sizeof(struct ieee80211_meshconf_ie) +
2419                                     sdata->u.mesh.ie_len);
2420                 if (!skb)
2421                         goto out;
2422 
2423                 skb_reserve(skb, local->hw.extra_tx_headroom);
2424                 mgmt = (struct ieee80211_mgmt *) skb_put(skb, hdr_len);
2425                 memset(mgmt, 0, hdr_len);
2426                 mgmt->frame_control =
2427                     cpu_to_le16(IEEE80211_FTYPE_MGMT | IEEE80211_STYPE_BEACON);
2428                 memset(mgmt->da, 0xff, ETH_ALEN);
2429                 memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
2430                 memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN);
2431                 mgmt->u.beacon.beacon_int =
2432                         cpu_to_le16(sdata->vif.bss_conf.beacon_int);
2433                 mgmt->u.beacon.capab_info |= cpu_to_le16(
2434                         sdata->u.mesh.security ? WLAN_CAPABILITY_PRIVACY : 0);
2435 
2436                 pos = skb_put(skb, 2);
2437                 *pos++ = WLAN_EID_SSID;
2438                 *pos++ = 0x0;
2439 
2440                 if (ieee80211_add_srates_ie(&sdata->vif, skb, true) ||
2441                     mesh_add_ds_params_ie(skb, sdata) ||
2442                     ieee80211_add_ext_srates_ie(&sdata->vif, skb, true) ||
2443                     mesh_add_rsn_ie(skb, sdata) ||
2444                     mesh_add_ht_cap_ie(skb, sdata) ||
2445                     mesh_add_ht_oper_ie(skb, sdata) ||
2446                     mesh_add_meshid_ie(skb, sdata) ||
2447                     mesh_add_meshconf_ie(skb, sdata) ||
2448                     mesh_add_vendor_ies(skb, sdata)) {
2449                         pr_err("o11s: couldn't add ies!\n");
2450                         goto out;
2451                 }
2452         } else {
2453                 WARN_ON(1);
2454                 goto out;
2455         }
2456 
2457         info = IEEE80211_SKB_CB(skb);
2458 
2459         info->flags |= IEEE80211_TX_INTFL_DONT_ENCRYPT;
2460         info->flags |= IEEE80211_TX_CTL_NO_ACK;
2461         info->band = band;
2462 
2463         memset(&txrc, 0, sizeof(txrc));
2464         txrc.hw = hw;
2465         txrc.sband = sband;
2466         txrc.bss_conf = &sdata->vif.bss_conf;
2467         txrc.skb = skb;
2468         txrc.reported_rate.idx = -1;
2469         txrc.rate_idx_mask = sdata->rc_rateidx_mask[band];
2470         if (txrc.rate_idx_mask == (1 << sband->n_bitrates) - 1)
2471                 txrc.max_rate_idx = -1;
2472         else
2473                 txrc.max_rate_idx = fls(txrc.rate_idx_mask) - 1;
2474         memcpy(txrc.rate_idx_mcs_mask, sdata->rc_rateidx_mcs_mask[band],
2475                sizeof(txrc.rate_idx_mcs_mask));
2476         txrc.bss = true;
2477         rate_control_get_rate(sdata, NULL, &txrc);
2478 
2479         info->control.vif = vif;
2480 
2481         info->flags |= IEEE80211_TX_CTL_CLEAR_PS_FILT |
2482                         IEEE80211_TX_CTL_ASSIGN_SEQ |
2483                         IEEE80211_TX_CTL_FIRST_FRAGMENT;
2484  out:
2485         rcu_read_unlock();
2486         return skb;
2487 }
2488 EXPORT_SYMBOL(ieee80211_beacon_get_tim);
2489 
2490 struct sk_buff *ieee80211_proberesp_get(struct ieee80211_hw *hw,
2491                                         struct ieee80211_vif *vif)
2492 {
2493         struct ieee80211_if_ap *ap = NULL;
2494         struct sk_buff *presp = NULL, *skb = NULL;
2495         struct ieee80211_hdr *hdr;
2496         struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
2497 
2498         if (sdata->vif.type != NL80211_IFTYPE_AP)
2499                 return NULL;
2500 
2501         rcu_read_lock();
2502 
2503         ap = &sdata->u.ap;
2504         presp = rcu_dereference(ap->probe_resp);
2505         if (!presp)
2506                 goto out;
2507 
2508         skb = skb_copy(presp, GFP_ATOMIC);
2509         if (!skb)
2510                 goto out;
2511 
2512         hdr = (struct ieee80211_hdr *) skb->data;
2513         memset(hdr->addr1, 0, sizeof(hdr->addr1));
2514 
2515 out:
2516         rcu_read_unlock();
2517         return skb;
2518 }
2519 EXPORT_SYMBOL(ieee80211_proberesp_get);
2520 
2521 struct sk_buff *ieee80211_pspoll_get(struct ieee80211_hw *hw,
2522                                      struct ieee80211_vif *vif)
2523 {
2524         struct ieee80211_sub_if_data *sdata;
2525         struct ieee80211_if_managed *ifmgd;
2526         struct ieee80211_pspoll *pspoll;
2527         struct ieee80211_local *local;
2528         struct sk_buff *skb;
2529 
2530         if (WARN_ON(vif->type != NL80211_IFTYPE_STATION))
2531                 return NULL;
2532 
2533         sdata = vif_to_sdata(vif);
2534         ifmgd = &sdata->u.mgd;
2535         local = sdata->local;
2536 
2537         skb = dev_alloc_skb(local->hw.extra_tx_headroom + sizeof(*pspoll));
2538         if (!skb)
2539                 return NULL;
2540 
2541         skb_reserve(skb, local->hw.extra_tx_headroom);
2542 
2543         pspoll = (struct ieee80211_pspoll *) skb_put(skb, sizeof(*pspoll));
2544         memset(pspoll, 0, sizeof(*pspoll));
2545         pspoll->frame_control = cpu_to_le16(IEEE80211_FTYPE_CTL |
2546                                             IEEE80211_STYPE_PSPOLL);
2547         pspoll->aid = cpu_to_le16(ifmgd->aid);
2548 
2549         /* aid in PS-Poll has its two MSBs each set to 1 */
2550         pspoll->aid |= cpu_to_le16(1 << 15 | 1 << 14);
2551 
2552         memcpy(pspoll->bssid, ifmgd->bssid, ETH_ALEN);
2553         memcpy(pspoll->ta, vif->addr, ETH_ALEN);
2554 
2555         return skb;
2556 }
2557 EXPORT_SYMBOL(ieee80211_pspoll_get);
2558 
2559 struct sk_buff *ieee80211_nullfunc_get(struct ieee80211_hw *hw,
2560                                        struct ieee80211_vif *vif)
2561 {
2562         struct ieee80211_hdr_3addr *nullfunc;
2563         struct ieee80211_sub_if_data *sdata;
2564         struct ieee80211_if_managed *ifmgd;
2565         struct ieee80211_local *local;
2566         struct sk_buff *skb;
2567 
2568         if (WARN_ON(vif->type != NL80211_IFTYPE_STATION))
2569                 return NULL;
2570 
2571         sdata = vif_to_sdata(vif);
2572         ifmgd = &sdata->u.mgd;
2573         local = sdata->local;
2574 
2575         skb = dev_alloc_skb(local->hw.extra_tx_headroom + sizeof(*nullfunc));
2576         if (!skb)
2577                 return NULL;
2578 
2579         skb_reserve(skb, local->hw.extra_tx_headroom);
2580 
2581         nullfunc = (struct ieee80211_hdr_3addr *) skb_put(skb,
2582                                                           sizeof(*nullfunc));
2583         memset(nullfunc, 0, sizeof(*nullfunc));
2584         nullfunc->frame_control = cpu_to_le16(IEEE80211_FTYPE_DATA |
2585                                               IEEE80211_STYPE_NULLFUNC |
2586                                               IEEE80211_FCTL_TODS);
2587         memcpy(nullfunc->addr1, ifmgd->bssid, ETH_ALEN);
2588         memcpy(nullfunc->addr2, vif->addr, ETH_ALEN);
2589         memcpy(nullfunc->addr3, ifmgd->bssid, ETH_ALEN);
2590 
2591         return skb;
2592 }
2593 EXPORT_SYMBOL(ieee80211_nullfunc_get);
2594 
2595 struct sk_buff *ieee80211_probereq_get(struct ieee80211_hw *hw,
2596                                        struct ieee80211_vif *vif,
2597                                        const u8 *ssid, size_t ssid_len,
2598                                        const u8 *ie, size_t ie_len)
2599 {
2600         struct ieee80211_sub_if_data *sdata;
2601         struct ieee80211_local *local;
2602         struct ieee80211_hdr_3addr *hdr;
2603         struct sk_buff *skb;
2604         size_t ie_ssid_len;
2605         u8 *pos;
2606 
2607         sdata = vif_to_sdata(vif);
2608         local = sdata->local;
2609         ie_ssid_len = 2 + ssid_len;
2610 
2611         skb = dev_alloc_skb(local->hw.extra_tx_headroom + sizeof(*hdr) +
2612                             ie_ssid_len + ie_len);
2613         if (!skb)
2614                 return NULL;
2615 
2616         skb_reserve(skb, local->hw.extra_tx_headroom);
2617 
2618         hdr = (struct ieee80211_hdr_3addr *) skb_put(skb, sizeof(*hdr));
2619         memset(hdr, 0, sizeof(*hdr));
2620         hdr->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
2621                                          IEEE80211_STYPE_PROBE_REQ);
2622         memset(hdr->addr1, 0xff, ETH_ALEN);
2623         memcpy(hdr->addr2, vif->addr, ETH_ALEN);
2624         memset(hdr->addr3, 0xff, ETH_ALEN);
2625 
2626         pos = skb_put(skb, ie_ssid_len);
2627         *pos++ = WLAN_EID_SSID;
2628         *pos++ = ssid_len;
2629         if (ssid_len)
2630                 memcpy(pos, ssid, ssid_len);
2631         pos += ssid_len;
2632 
2633         if (ie) {
2634                 pos = skb_put(skb, ie_len);
2635                 memcpy(pos, ie, ie_len);
2636         }
2637 
2638         return skb;
2639 }
2640 EXPORT_SYMBOL(ieee80211_probereq_get);
2641 
2642 void ieee80211_rts_get(struct ieee80211_hw *hw, struct ieee80211_vif *vif,
2643                        const void *frame, size_t frame_len,
2644                        const struct ieee80211_tx_info *frame_txctl,
2645                        struct ieee80211_rts *rts)
2646 {
2647         const struct ieee80211_hdr *hdr = frame;
2648 
2649         rts->frame_control =
2650             cpu_to_le16(IEEE80211_FTYPE_CTL | IEEE80211_STYPE_RTS);
2651         rts->duration = ieee80211_rts_duration(hw, vif, frame_len,
2652                                                frame_txctl);
2653         memcpy(rts->ra, hdr->addr1, sizeof(rts->ra));
2654         memcpy(rts->ta, hdr->addr2, sizeof(rts->ta));
2655 }
2656 EXPORT_SYMBOL(ieee80211_rts_get);
2657 
2658 void ieee80211_ctstoself_get(struct ieee80211_hw *hw, struct ieee80211_vif *vif,
2659                              const void *frame, size_t frame_len,
2660                              const struct ieee80211_tx_info *frame_txctl,
2661                              struct ieee80211_cts *cts)
2662 {
2663         const struct ieee80211_hdr *hdr = frame;
2664 
2665         cts->frame_control =
2666             cpu_to_le16(IEEE80211_FTYPE_CTL | IEEE80211_STYPE_CTS);
2667         cts->duration = ieee80211_ctstoself_duration(hw, vif,
2668                                                      frame_len, frame_txctl);
2669         memcpy(cts->ra, hdr->addr1, sizeof(cts->ra));
2670 }
2671 EXPORT_SYMBOL(ieee80211_ctstoself_get);
2672 
2673 struct sk_buff *
2674 ieee80211_get_buffered_bc(struct ieee80211_hw *hw,
2675                           struct ieee80211_vif *vif)
2676 {
2677         struct ieee80211_local *local = hw_to_local(hw);
2678         struct sk_buff *skb = NULL;
2679         struct ieee80211_tx_data tx;
2680         struct ieee80211_sub_if_data *sdata;
2681         struct ieee80211_if_ap *bss = NULL;
2682         struct beacon_data *beacon;
2683         struct ieee80211_tx_info *info;
2684 
2685         sdata = vif_to_sdata(vif);
2686         bss = &sdata->u.ap;
2687 
2688         rcu_read_lock();
2689         beacon = rcu_dereference(bss->beacon);
2690 
2691         if (sdata->vif.type != NL80211_IFTYPE_AP || !beacon || !beacon->head)
2692                 goto out;
2693 
2694         if (bss->dtim_count != 0 || !bss->dtim_bc_mc)
2695                 goto out; /* send buffered bc/mc only after DTIM beacon */
2696 
2697         while (1) {
2698                 skb = skb_dequeue(&bss->ps_bc_buf);
2699                 if (!skb)
2700                         goto out;
2701                 local->total_ps_buffered--;
2702 
2703                 if (!skb_queue_empty(&bss->ps_bc_buf) && skb->len >= 2) {
2704                         struct ieee80211_hdr *hdr =
2705                                 (struct ieee80211_hdr *) skb->data;
2706                         /* more buffered multicast/broadcast frames ==> set
2707                          * MoreData flag in IEEE 802.11 header to inform PS
2708                          * STAs */
2709                         hdr->frame_control |=
2710                                 cpu_to_le16(IEEE80211_FCTL_MOREDATA);
2711                 }
2712 
2713                 if (!ieee80211_tx_prepare(sdata, &tx, skb))
2714                         break;
2715                 dev_kfree_skb_any(skb);
2716         }
2717 
2718         info = IEEE80211_SKB_CB(skb);
2719 
2720         tx.flags |= IEEE80211_TX_PS_BUFFERED;
2721         tx.channel = local->hw.conf.channel;
2722         info->band = tx.channel->band;
2723 
2724         if (invoke_tx_handlers(&tx))
2725                 skb = NULL;
2726  out:
2727         rcu_read_unlock();
2728 
2729         return skb;
2730 }
2731 EXPORT_SYMBOL(ieee80211_get_buffered_bc);
2732 
2733 void ieee80211_tx_skb_tid(struct ieee80211_sub_if_data *sdata,
2734                           struct sk_buff *skb, int tid)
2735 {
2736         int ac = ieee802_1d_to_ac[tid & 7];
2737 
2738         skb_set_mac_header(skb, 0);
2739         skb_set_network_header(skb, 0);
2740         skb_set_transport_header(skb, 0);
2741 
2742         skb_set_queue_mapping(skb, ac);
2743         skb->priority = tid;
2744 
2745         /*
2746          * The other path calling ieee80211_xmit is from the tasklet,
2747          * and while we can handle concurrent transmissions locking
2748          * requirements are that we do not come into tx with bhs on.
2749          */
2750         local_bh_disable();
2751         ieee80211_xmit(sdata, skb);
2752         local_bh_enable();
2753 }
2754 

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