xref: /linux/net/mac80211/tx.c (revision 89e47d3b8a273b0eac21e4bf6d7fdb86b654fa16)
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 <linux/time.h>
23 #include <net/net_namespace.h>
24 #include <net/ieee80211_radiotap.h>
25 #include <net/cfg80211.h>
26 #include <net/mac80211.h>
27 #include <asm/unaligned.h>
28 
29 #include "ieee80211_i.h"
30 #include "driver-ops.h"
31 #include "led.h"
32 #include "mesh.h"
33 #include "wep.h"
34 #include "wpa.h"
35 #include "wme.h"
36 #include "rate.h"
37 
38 /* misc utils */
39 
40 static __le16 ieee80211_duration(struct ieee80211_tx_data *tx,
41 				 struct sk_buff *skb, int group_addr,
42 				 int next_frag_len)
43 {
44 	int rate, mrate, erp, dur, i, shift = 0;
45 	struct ieee80211_rate *txrate;
46 	struct ieee80211_local *local = tx->local;
47 	struct ieee80211_supported_band *sband;
48 	struct ieee80211_hdr *hdr;
49 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
50 	struct ieee80211_chanctx_conf *chanctx_conf;
51 	u32 rate_flags = 0;
52 
53 	rcu_read_lock();
54 	chanctx_conf = rcu_dereference(tx->sdata->vif.chanctx_conf);
55 	if (chanctx_conf) {
56 		shift = ieee80211_chandef_get_shift(&chanctx_conf->def);
57 		rate_flags = ieee80211_chandef_rate_flags(&chanctx_conf->def);
58 	}
59 	rcu_read_unlock();
60 
61 	/* assume HW handles this */
62 	if (tx->rate.flags & IEEE80211_TX_RC_MCS)
63 		return 0;
64 
65 	/* uh huh? */
66 	if (WARN_ON_ONCE(tx->rate.idx < 0))
67 		return 0;
68 
69 	sband = local->hw.wiphy->bands[info->band];
70 	txrate = &sband->bitrates[tx->rate.idx];
71 
72 	erp = txrate->flags & IEEE80211_RATE_ERP_G;
73 
74 	/*
75 	 * data and mgmt (except PS Poll):
76 	 * - during CFP: 32768
77 	 * - during contention period:
78 	 *   if addr1 is group address: 0
79 	 *   if more fragments = 0 and addr1 is individual address: time to
80 	 *      transmit one ACK plus SIFS
81 	 *   if more fragments = 1 and addr1 is individual address: time to
82 	 *      transmit next fragment plus 2 x ACK plus 3 x SIFS
83 	 *
84 	 * IEEE 802.11, 9.6:
85 	 * - control response frame (CTS or ACK) shall be transmitted using the
86 	 *   same rate as the immediately previous frame in the frame exchange
87 	 *   sequence, if this rate belongs to the PHY mandatory rates, or else
88 	 *   at the highest possible rate belonging to the PHY rates in the
89 	 *   BSSBasicRateSet
90 	 */
91 	hdr = (struct ieee80211_hdr *)skb->data;
92 	if (ieee80211_is_ctl(hdr->frame_control)) {
93 		/* TODO: These control frames are not currently sent by
94 		 * mac80211, but should they be implemented, this function
95 		 * needs to be updated to support duration field calculation.
96 		 *
97 		 * RTS: time needed to transmit pending data/mgmt frame plus
98 		 *    one CTS frame plus one ACK frame plus 3 x SIFS
99 		 * CTS: duration of immediately previous RTS minus time
100 		 *    required to transmit CTS and its SIFS
101 		 * ACK: 0 if immediately previous directed data/mgmt had
102 		 *    more=0, with more=1 duration in ACK frame is duration
103 		 *    from previous frame minus time needed to transmit ACK
104 		 *    and its SIFS
105 		 * PS Poll: BIT(15) | BIT(14) | aid
106 		 */
107 		return 0;
108 	}
109 
110 	/* data/mgmt */
111 	if (0 /* FIX: data/mgmt during CFP */)
112 		return cpu_to_le16(32768);
113 
114 	if (group_addr) /* Group address as the destination - no ACK */
115 		return 0;
116 
117 	/* Individual destination address:
118 	 * IEEE 802.11, Ch. 9.6 (after IEEE 802.11g changes)
119 	 * CTS and ACK frames shall be transmitted using the highest rate in
120 	 * basic rate set that is less than or equal to the rate of the
121 	 * immediately previous frame and that is using the same modulation
122 	 * (CCK or OFDM). If no basic rate set matches with these requirements,
123 	 * the highest mandatory rate of the PHY that is less than or equal to
124 	 * the rate of the previous frame is used.
125 	 * Mandatory rates for IEEE 802.11g PHY: 1, 2, 5.5, 11, 6, 12, 24 Mbps
126 	 */
127 	rate = -1;
128 	/* use lowest available if everything fails */
129 	mrate = sband->bitrates[0].bitrate;
130 	for (i = 0; i < sband->n_bitrates; i++) {
131 		struct ieee80211_rate *r = &sband->bitrates[i];
132 
133 		if (r->bitrate > txrate->bitrate)
134 			break;
135 
136 		if ((rate_flags & r->flags) != rate_flags)
137 			continue;
138 
139 		if (tx->sdata->vif.bss_conf.basic_rates & BIT(i))
140 			rate = DIV_ROUND_UP(r->bitrate, 1 << shift);
141 
142 		switch (sband->band) {
143 		case IEEE80211_BAND_2GHZ: {
144 			u32 flag;
145 			if (tx->sdata->flags & IEEE80211_SDATA_OPERATING_GMODE)
146 				flag = IEEE80211_RATE_MANDATORY_G;
147 			else
148 				flag = IEEE80211_RATE_MANDATORY_B;
149 			if (r->flags & flag)
150 				mrate = r->bitrate;
151 			break;
152 		}
153 		case IEEE80211_BAND_5GHZ:
154 			if (r->flags & IEEE80211_RATE_MANDATORY_A)
155 				mrate = r->bitrate;
156 			break;
157 		case IEEE80211_BAND_60GHZ:
158 			/* TODO, for now fall through */
159 		case IEEE80211_NUM_BANDS:
160 			WARN_ON(1);
161 			break;
162 		}
163 	}
164 	if (rate == -1) {
165 		/* No matching basic rate found; use highest suitable mandatory
166 		 * PHY rate */
167 		rate = DIV_ROUND_UP(mrate, 1 << shift);
168 	}
169 
170 	/* Don't calculate ACKs for QoS Frames with NoAck Policy set */
171 	if (ieee80211_is_data_qos(hdr->frame_control) &&
172 	    *(ieee80211_get_qos_ctl(hdr)) & IEEE80211_QOS_CTL_ACK_POLICY_NOACK)
173 		dur = 0;
174 	else
175 		/* Time needed to transmit ACK
176 		 * (10 bytes + 4-byte FCS = 112 bits) plus SIFS; rounded up
177 		 * to closest integer */
178 		dur = ieee80211_frame_duration(sband->band, 10, rate, erp,
179 				tx->sdata->vif.bss_conf.use_short_preamble,
180 				shift);
181 
182 	if (next_frag_len) {
183 		/* Frame is fragmented: duration increases with time needed to
184 		 * transmit next fragment plus ACK and 2 x SIFS. */
185 		dur *= 2; /* ACK + SIFS */
186 		/* next fragment */
187 		dur += ieee80211_frame_duration(sband->band, next_frag_len,
188 				txrate->bitrate, erp,
189 				tx->sdata->vif.bss_conf.use_short_preamble,
190 				shift);
191 	}
192 
193 	return cpu_to_le16(dur);
194 }
195 
196 /* tx handlers */
197 static ieee80211_tx_result debug_noinline
198 ieee80211_tx_h_dynamic_ps(struct ieee80211_tx_data *tx)
199 {
200 	struct ieee80211_local *local = tx->local;
201 	struct ieee80211_if_managed *ifmgd;
202 
203 	/* driver doesn't support power save */
204 	if (!(local->hw.flags & IEEE80211_HW_SUPPORTS_PS))
205 		return TX_CONTINUE;
206 
207 	/* hardware does dynamic power save */
208 	if (local->hw.flags & IEEE80211_HW_SUPPORTS_DYNAMIC_PS)
209 		return TX_CONTINUE;
210 
211 	/* dynamic power save disabled */
212 	if (local->hw.conf.dynamic_ps_timeout <= 0)
213 		return TX_CONTINUE;
214 
215 	/* we are scanning, don't enable power save */
216 	if (local->scanning)
217 		return TX_CONTINUE;
218 
219 	if (!local->ps_sdata)
220 		return TX_CONTINUE;
221 
222 	/* No point if we're going to suspend */
223 	if (local->quiescing)
224 		return TX_CONTINUE;
225 
226 	/* dynamic ps is supported only in managed mode */
227 	if (tx->sdata->vif.type != NL80211_IFTYPE_STATION)
228 		return TX_CONTINUE;
229 
230 	ifmgd = &tx->sdata->u.mgd;
231 
232 	/*
233 	 * Don't wakeup from power save if u-apsd is enabled, voip ac has
234 	 * u-apsd enabled and the frame is in voip class. This effectively
235 	 * means that even if all access categories have u-apsd enabled, in
236 	 * practise u-apsd is only used with the voip ac. This is a
237 	 * workaround for the case when received voip class packets do not
238 	 * have correct qos tag for some reason, due the network or the
239 	 * peer application.
240 	 *
241 	 * Note: ifmgd->uapsd_queues access is racy here. If the value is
242 	 * changed via debugfs, user needs to reassociate manually to have
243 	 * everything in sync.
244 	 */
245 	if ((ifmgd->flags & IEEE80211_STA_UAPSD_ENABLED) &&
246 	    (ifmgd->uapsd_queues & IEEE80211_WMM_IE_STA_QOSINFO_AC_VO) &&
247 	    skb_get_queue_mapping(tx->skb) == IEEE80211_AC_VO)
248 		return TX_CONTINUE;
249 
250 	if (local->hw.conf.flags & IEEE80211_CONF_PS) {
251 		ieee80211_stop_queues_by_reason(&local->hw,
252 						IEEE80211_MAX_QUEUE_MAP,
253 						IEEE80211_QUEUE_STOP_REASON_PS);
254 		ifmgd->flags &= ~IEEE80211_STA_NULLFUNC_ACKED;
255 		ieee80211_queue_work(&local->hw,
256 				     &local->dynamic_ps_disable_work);
257 	}
258 
259 	/* Don't restart the timer if we're not disassociated */
260 	if (!ifmgd->associated)
261 		return TX_CONTINUE;
262 
263 	mod_timer(&local->dynamic_ps_timer, jiffies +
264 		  msecs_to_jiffies(local->hw.conf.dynamic_ps_timeout));
265 
266 	return TX_CONTINUE;
267 }
268 
269 static ieee80211_tx_result debug_noinline
270 ieee80211_tx_h_check_assoc(struct ieee80211_tx_data *tx)
271 {
272 
273 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)tx->skb->data;
274 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(tx->skb);
275 	bool assoc = false;
276 
277 	if (unlikely(info->flags & IEEE80211_TX_CTL_INJECTED))
278 		return TX_CONTINUE;
279 
280 	if (unlikely(test_bit(SCAN_SW_SCANNING, &tx->local->scanning)) &&
281 	    test_bit(SDATA_STATE_OFFCHANNEL, &tx->sdata->state) &&
282 	    !ieee80211_is_probe_req(hdr->frame_control) &&
283 	    !ieee80211_is_nullfunc(hdr->frame_control))
284 		/*
285 		 * When software scanning only nullfunc frames (to notify
286 		 * the sleep state to the AP) and probe requests (for the
287 		 * active scan) are allowed, all other frames should not be
288 		 * sent and we should not get here, but if we do
289 		 * nonetheless, drop them to avoid sending them
290 		 * off-channel. See the link below and
291 		 * ieee80211_start_scan() for more.
292 		 *
293 		 * http://article.gmane.org/gmane.linux.kernel.wireless.general/30089
294 		 */
295 		return TX_DROP;
296 
297 	if (tx->sdata->vif.type == NL80211_IFTYPE_WDS)
298 		return TX_CONTINUE;
299 
300 	if (tx->sdata->vif.type == NL80211_IFTYPE_MESH_POINT)
301 		return TX_CONTINUE;
302 
303 	if (tx->flags & IEEE80211_TX_PS_BUFFERED)
304 		return TX_CONTINUE;
305 
306 	if (tx->sta)
307 		assoc = test_sta_flag(tx->sta, WLAN_STA_ASSOC);
308 
309 	if (likely(tx->flags & IEEE80211_TX_UNICAST)) {
310 		if (unlikely(!assoc &&
311 			     ieee80211_is_data(hdr->frame_control))) {
312 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG
313 			sdata_info(tx->sdata,
314 				   "dropped data frame to not associated station %pM\n",
315 				   hdr->addr1);
316 #endif
317 			I802_DEBUG_INC(tx->local->tx_handlers_drop_not_assoc);
318 			return TX_DROP;
319 		}
320 	} else if (unlikely(tx->sdata->vif.type == NL80211_IFTYPE_AP &&
321 			    ieee80211_is_data(hdr->frame_control) &&
322 			    !atomic_read(&tx->sdata->u.ap.num_mcast_sta))) {
323 		/*
324 		 * No associated STAs - no need to send multicast
325 		 * frames.
326 		 */
327 		return TX_DROP;
328 	}
329 
330 	return TX_CONTINUE;
331 }
332 
333 /* This function is called whenever the AP is about to exceed the maximum limit
334  * of buffered frames for power saving STAs. This situation should not really
335  * happen often during normal operation, so dropping the oldest buffered packet
336  * from each queue should be OK to make some room for new frames. */
337 static void purge_old_ps_buffers(struct ieee80211_local *local)
338 {
339 	int total = 0, purged = 0;
340 	struct sk_buff *skb;
341 	struct ieee80211_sub_if_data *sdata;
342 	struct sta_info *sta;
343 
344 	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
345 		struct ps_data *ps;
346 
347 		if (sdata->vif.type == NL80211_IFTYPE_AP)
348 			ps = &sdata->u.ap.ps;
349 		else if (ieee80211_vif_is_mesh(&sdata->vif))
350 			ps = &sdata->u.mesh.ps;
351 		else
352 			continue;
353 
354 		skb = skb_dequeue(&ps->bc_buf);
355 		if (skb) {
356 			purged++;
357 			dev_kfree_skb(skb);
358 		}
359 		total += skb_queue_len(&ps->bc_buf);
360 	}
361 
362 	/*
363 	 * Drop one frame from each station from the lowest-priority
364 	 * AC that has frames at all.
365 	 */
366 	list_for_each_entry_rcu(sta, &local->sta_list, list) {
367 		int ac;
368 
369 		for (ac = IEEE80211_AC_BK; ac >= IEEE80211_AC_VO; ac--) {
370 			skb = skb_dequeue(&sta->ps_tx_buf[ac]);
371 			total += skb_queue_len(&sta->ps_tx_buf[ac]);
372 			if (skb) {
373 				purged++;
374 				ieee80211_free_txskb(&local->hw, skb);
375 				break;
376 			}
377 		}
378 	}
379 
380 	local->total_ps_buffered = total;
381 	ps_dbg_hw(&local->hw, "PS buffers full - purged %d frames\n", purged);
382 }
383 
384 static ieee80211_tx_result
385 ieee80211_tx_h_multicast_ps_buf(struct ieee80211_tx_data *tx)
386 {
387 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(tx->skb);
388 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)tx->skb->data;
389 	struct ps_data *ps;
390 
391 	/*
392 	 * broadcast/multicast frame
393 	 *
394 	 * If any of the associated/peer stations is in power save mode,
395 	 * the frame is buffered to be sent after DTIM beacon frame.
396 	 * This is done either by the hardware or us.
397 	 */
398 
399 	/* powersaving STAs currently only in AP/VLAN/mesh mode */
400 	if (tx->sdata->vif.type == NL80211_IFTYPE_AP ||
401 	    tx->sdata->vif.type == NL80211_IFTYPE_AP_VLAN) {
402 		if (!tx->sdata->bss)
403 			return TX_CONTINUE;
404 
405 		ps = &tx->sdata->bss->ps;
406 	} else if (ieee80211_vif_is_mesh(&tx->sdata->vif)) {
407 		ps = &tx->sdata->u.mesh.ps;
408 	} else {
409 		return TX_CONTINUE;
410 	}
411 
412 
413 	/* no buffering for ordered frames */
414 	if (ieee80211_has_order(hdr->frame_control))
415 		return TX_CONTINUE;
416 
417 	if (tx->local->hw.flags & IEEE80211_HW_QUEUE_CONTROL)
418 		info->hw_queue = tx->sdata->vif.cab_queue;
419 
420 	/* no stations in PS mode */
421 	if (!atomic_read(&ps->num_sta_ps))
422 		return TX_CONTINUE;
423 
424 	info->flags |= IEEE80211_TX_CTL_SEND_AFTER_DTIM;
425 
426 	/* device releases frame after DTIM beacon */
427 	if (!(tx->local->hw.flags & IEEE80211_HW_HOST_BROADCAST_PS_BUFFERING))
428 		return TX_CONTINUE;
429 
430 	/* buffered in mac80211 */
431 	if (tx->local->total_ps_buffered >= TOTAL_MAX_TX_BUFFER)
432 		purge_old_ps_buffers(tx->local);
433 
434 	if (skb_queue_len(&ps->bc_buf) >= AP_MAX_BC_BUFFER) {
435 		ps_dbg(tx->sdata,
436 		       "BC TX buffer full - dropping the oldest frame\n");
437 		dev_kfree_skb(skb_dequeue(&ps->bc_buf));
438 	} else
439 		tx->local->total_ps_buffered++;
440 
441 	skb_queue_tail(&ps->bc_buf, tx->skb);
442 
443 	return TX_QUEUED;
444 }
445 
446 static int ieee80211_use_mfp(__le16 fc, struct sta_info *sta,
447 			     struct sk_buff *skb)
448 {
449 	if (!ieee80211_is_mgmt(fc))
450 		return 0;
451 
452 	if (sta == NULL || !test_sta_flag(sta, WLAN_STA_MFP))
453 		return 0;
454 
455 	if (!ieee80211_is_robust_mgmt_frame((struct ieee80211_hdr *)
456 					    skb->data))
457 		return 0;
458 
459 	return 1;
460 }
461 
462 static ieee80211_tx_result
463 ieee80211_tx_h_unicast_ps_buf(struct ieee80211_tx_data *tx)
464 {
465 	struct sta_info *sta = tx->sta;
466 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(tx->skb);
467 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)tx->skb->data;
468 	struct ieee80211_local *local = tx->local;
469 
470 	if (unlikely(!sta))
471 		return TX_CONTINUE;
472 
473 	if (unlikely((test_sta_flag(sta, WLAN_STA_PS_STA) ||
474 		      test_sta_flag(sta, WLAN_STA_PS_DRIVER)) &&
475 		     !(info->flags & IEEE80211_TX_CTL_NO_PS_BUFFER))) {
476 		int ac = skb_get_queue_mapping(tx->skb);
477 
478 		/* only deauth, disassoc and action are bufferable MMPDUs */
479 		if (ieee80211_is_mgmt(hdr->frame_control) &&
480 		    !ieee80211_is_deauth(hdr->frame_control) &&
481 		    !ieee80211_is_disassoc(hdr->frame_control) &&
482 		    !ieee80211_is_action(hdr->frame_control)) {
483 			info->flags |= IEEE80211_TX_CTL_NO_PS_BUFFER;
484 			return TX_CONTINUE;
485 		}
486 
487 		ps_dbg(sta->sdata, "STA %pM aid %d: PS buffer for AC %d\n",
488 		       sta->sta.addr, sta->sta.aid, ac);
489 		if (tx->local->total_ps_buffered >= TOTAL_MAX_TX_BUFFER)
490 			purge_old_ps_buffers(tx->local);
491 		if (skb_queue_len(&sta->ps_tx_buf[ac]) >= STA_MAX_TX_BUFFER) {
492 			struct sk_buff *old = skb_dequeue(&sta->ps_tx_buf[ac]);
493 			ps_dbg(tx->sdata,
494 			       "STA %pM TX buffer for AC %d full - dropping oldest frame\n",
495 			       sta->sta.addr, ac);
496 			ieee80211_free_txskb(&local->hw, old);
497 		} else
498 			tx->local->total_ps_buffered++;
499 
500 		info->control.jiffies = jiffies;
501 		info->control.vif = &tx->sdata->vif;
502 		info->flags |= IEEE80211_TX_INTFL_NEED_TXPROCESSING;
503 		skb_queue_tail(&sta->ps_tx_buf[ac], tx->skb);
504 
505 		if (!timer_pending(&local->sta_cleanup))
506 			mod_timer(&local->sta_cleanup,
507 				  round_jiffies(jiffies +
508 						STA_INFO_CLEANUP_INTERVAL));
509 
510 		/*
511 		 * We queued up some frames, so the TIM bit might
512 		 * need to be set, recalculate it.
513 		 */
514 		sta_info_recalc_tim(sta);
515 
516 		return TX_QUEUED;
517 	} else if (unlikely(test_sta_flag(sta, WLAN_STA_PS_STA))) {
518 		ps_dbg(tx->sdata,
519 		       "STA %pM in PS mode, but polling/in SP -> send frame\n",
520 		       sta->sta.addr);
521 	}
522 
523 	return TX_CONTINUE;
524 }
525 
526 static ieee80211_tx_result debug_noinline
527 ieee80211_tx_h_ps_buf(struct ieee80211_tx_data *tx)
528 {
529 	if (unlikely(tx->flags & IEEE80211_TX_PS_BUFFERED))
530 		return TX_CONTINUE;
531 
532 	if (tx->flags & IEEE80211_TX_UNICAST)
533 		return ieee80211_tx_h_unicast_ps_buf(tx);
534 	else
535 		return ieee80211_tx_h_multicast_ps_buf(tx);
536 }
537 
538 static ieee80211_tx_result debug_noinline
539 ieee80211_tx_h_check_control_port_protocol(struct ieee80211_tx_data *tx)
540 {
541 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(tx->skb);
542 
543 	if (unlikely(tx->sdata->control_port_protocol == tx->skb->protocol)) {
544 		if (tx->sdata->control_port_no_encrypt)
545 			info->flags |= IEEE80211_TX_INTFL_DONT_ENCRYPT;
546 		info->control.flags |= IEEE80211_TX_CTRL_PORT_CTRL_PROTO;
547 	}
548 
549 	return TX_CONTINUE;
550 }
551 
552 static ieee80211_tx_result debug_noinline
553 ieee80211_tx_h_select_key(struct ieee80211_tx_data *tx)
554 {
555 	struct ieee80211_key *key;
556 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(tx->skb);
557 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)tx->skb->data;
558 
559 	if (unlikely(info->flags & IEEE80211_TX_INTFL_DONT_ENCRYPT))
560 		tx->key = NULL;
561 	else if (tx->sta &&
562 		 (key = rcu_dereference(tx->sta->ptk[tx->sta->ptk_idx])))
563 		tx->key = key;
564 	else if (ieee80211_is_mgmt(hdr->frame_control) &&
565 		 is_multicast_ether_addr(hdr->addr1) &&
566 		 ieee80211_is_robust_mgmt_frame(hdr) &&
567 		 (key = rcu_dereference(tx->sdata->default_mgmt_key)))
568 		tx->key = key;
569 	else if (is_multicast_ether_addr(hdr->addr1) &&
570 		 (key = rcu_dereference(tx->sdata->default_multicast_key)))
571 		tx->key = key;
572 	else if (!is_multicast_ether_addr(hdr->addr1) &&
573 		 (key = rcu_dereference(tx->sdata->default_unicast_key)))
574 		tx->key = key;
575 	else if (info->flags & IEEE80211_TX_CTL_INJECTED)
576 		tx->key = NULL;
577 	else if (!tx->sdata->drop_unencrypted)
578 		tx->key = NULL;
579 	else if (tx->skb->protocol == tx->sdata->control_port_protocol)
580 		tx->key = NULL;
581 	else if (ieee80211_is_robust_mgmt_frame(hdr) &&
582 		 !(ieee80211_is_action(hdr->frame_control) &&
583 		   tx->sta && test_sta_flag(tx->sta, WLAN_STA_MFP)))
584 		tx->key = NULL;
585 	else if (ieee80211_is_mgmt(hdr->frame_control) &&
586 		 !ieee80211_is_robust_mgmt_frame(hdr))
587 		tx->key = NULL;
588 	else {
589 		I802_DEBUG_INC(tx->local->tx_handlers_drop_unencrypted);
590 		return TX_DROP;
591 	}
592 
593 	if (tx->key) {
594 		bool skip_hw = false;
595 
596 		tx->key->tx_rx_count++;
597 		/* TODO: add threshold stuff again */
598 
599 		switch (tx->key->conf.cipher) {
600 		case WLAN_CIPHER_SUITE_WEP40:
601 		case WLAN_CIPHER_SUITE_WEP104:
602 		case WLAN_CIPHER_SUITE_TKIP:
603 			if (!ieee80211_is_data_present(hdr->frame_control))
604 				tx->key = NULL;
605 			break;
606 		case WLAN_CIPHER_SUITE_CCMP:
607 			if (!ieee80211_is_data_present(hdr->frame_control) &&
608 			    !ieee80211_use_mfp(hdr->frame_control, tx->sta,
609 					       tx->skb))
610 				tx->key = NULL;
611 			else
612 				skip_hw = (tx->key->conf.flags &
613 					   IEEE80211_KEY_FLAG_SW_MGMT_TX) &&
614 					ieee80211_is_mgmt(hdr->frame_control);
615 			break;
616 		case WLAN_CIPHER_SUITE_AES_CMAC:
617 			if (!ieee80211_is_mgmt(hdr->frame_control))
618 				tx->key = NULL;
619 			break;
620 		}
621 
622 		if (unlikely(tx->key && tx->key->flags & KEY_FLAG_TAINTED &&
623 			     !ieee80211_is_deauth(hdr->frame_control)))
624 			return TX_DROP;
625 
626 		if (!skip_hw && tx->key &&
627 		    tx->key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE)
628 			info->control.hw_key = &tx->key->conf;
629 	}
630 
631 	return TX_CONTINUE;
632 }
633 
634 static ieee80211_tx_result debug_noinline
635 ieee80211_tx_h_rate_ctrl(struct ieee80211_tx_data *tx)
636 {
637 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(tx->skb);
638 	struct ieee80211_hdr *hdr = (void *)tx->skb->data;
639 	struct ieee80211_supported_band *sband;
640 	u32 len;
641 	struct ieee80211_tx_rate_control txrc;
642 	struct ieee80211_sta_rates *ratetbl = NULL;
643 	bool assoc = false;
644 
645 	memset(&txrc, 0, sizeof(txrc));
646 
647 	sband = tx->local->hw.wiphy->bands[info->band];
648 
649 	len = min_t(u32, tx->skb->len + FCS_LEN,
650 			 tx->local->hw.wiphy->frag_threshold);
651 
652 	/* set up the tx rate control struct we give the RC algo */
653 	txrc.hw = &tx->local->hw;
654 	txrc.sband = sband;
655 	txrc.bss_conf = &tx->sdata->vif.bss_conf;
656 	txrc.skb = tx->skb;
657 	txrc.reported_rate.idx = -1;
658 	txrc.rate_idx_mask = tx->sdata->rc_rateidx_mask[info->band];
659 	if (txrc.rate_idx_mask == (1 << sband->n_bitrates) - 1)
660 		txrc.max_rate_idx = -1;
661 	else
662 		txrc.max_rate_idx = fls(txrc.rate_idx_mask) - 1;
663 
664 	if (tx->sdata->rc_has_mcs_mask[info->band])
665 		txrc.rate_idx_mcs_mask =
666 			tx->sdata->rc_rateidx_mcs_mask[info->band];
667 
668 	txrc.bss = (tx->sdata->vif.type == NL80211_IFTYPE_AP ||
669 		    tx->sdata->vif.type == NL80211_IFTYPE_MESH_POINT ||
670 		    tx->sdata->vif.type == NL80211_IFTYPE_ADHOC);
671 
672 	/* set up RTS protection if desired */
673 	if (len > tx->local->hw.wiphy->rts_threshold) {
674 		txrc.rts = true;
675 	}
676 
677 	info->control.use_rts = txrc.rts;
678 	info->control.use_cts_prot = tx->sdata->vif.bss_conf.use_cts_prot;
679 
680 	/*
681 	 * Use short preamble if the BSS can handle it, but not for
682 	 * management frames unless we know the receiver can handle
683 	 * that -- the management frame might be to a station that
684 	 * just wants a probe response.
685 	 */
686 	if (tx->sdata->vif.bss_conf.use_short_preamble &&
687 	    (ieee80211_is_data(hdr->frame_control) ||
688 	     (tx->sta && test_sta_flag(tx->sta, WLAN_STA_SHORT_PREAMBLE))))
689 		txrc.short_preamble = true;
690 
691 	info->control.short_preamble = txrc.short_preamble;
692 
693 	if (tx->sta)
694 		assoc = test_sta_flag(tx->sta, WLAN_STA_ASSOC);
695 
696 	/*
697 	 * Lets not bother rate control if we're associated and cannot
698 	 * talk to the sta. This should not happen.
699 	 */
700 	if (WARN(test_bit(SCAN_SW_SCANNING, &tx->local->scanning) && assoc &&
701 		 !rate_usable_index_exists(sband, &tx->sta->sta),
702 		 "%s: Dropped data frame as no usable bitrate found while "
703 		 "scanning and associated. Target station: "
704 		 "%pM on %d GHz band\n",
705 		 tx->sdata->name, hdr->addr1,
706 		 info->band ? 5 : 2))
707 		return TX_DROP;
708 
709 	/*
710 	 * If we're associated with the sta at this point we know we can at
711 	 * least send the frame at the lowest bit rate.
712 	 */
713 	rate_control_get_rate(tx->sdata, tx->sta, &txrc);
714 
715 	if (tx->sta && !info->control.skip_table)
716 		ratetbl = rcu_dereference(tx->sta->sta.rates);
717 
718 	if (unlikely(info->control.rates[0].idx < 0)) {
719 		if (ratetbl) {
720 			struct ieee80211_tx_rate rate = {
721 				.idx = ratetbl->rate[0].idx,
722 				.flags = ratetbl->rate[0].flags,
723 				.count = ratetbl->rate[0].count
724 			};
725 
726 			if (ratetbl->rate[0].idx < 0)
727 				return TX_DROP;
728 
729 			tx->rate = rate;
730 		} else {
731 			return TX_DROP;
732 		}
733 	} else {
734 		tx->rate = info->control.rates[0];
735 	}
736 
737 	if (txrc.reported_rate.idx < 0) {
738 		txrc.reported_rate = tx->rate;
739 		if (tx->sta && ieee80211_is_data(hdr->frame_control))
740 			tx->sta->last_tx_rate = txrc.reported_rate;
741 	} else if (tx->sta)
742 		tx->sta->last_tx_rate = txrc.reported_rate;
743 
744 	if (ratetbl)
745 		return TX_CONTINUE;
746 
747 	if (unlikely(!info->control.rates[0].count))
748 		info->control.rates[0].count = 1;
749 
750 	if (WARN_ON_ONCE((info->control.rates[0].count > 1) &&
751 			 (info->flags & IEEE80211_TX_CTL_NO_ACK)))
752 		info->control.rates[0].count = 1;
753 
754 	return TX_CONTINUE;
755 }
756 
757 static ieee80211_tx_result debug_noinline
758 ieee80211_tx_h_sequence(struct ieee80211_tx_data *tx)
759 {
760 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(tx->skb);
761 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)tx->skb->data;
762 	u16 *seq;
763 	u8 *qc;
764 	int tid;
765 
766 	/*
767 	 * Packet injection may want to control the sequence
768 	 * number, if we have no matching interface then we
769 	 * neither assign one ourselves nor ask the driver to.
770 	 */
771 	if (unlikely(info->control.vif->type == NL80211_IFTYPE_MONITOR))
772 		return TX_CONTINUE;
773 
774 	if (unlikely(ieee80211_is_ctl(hdr->frame_control)))
775 		return TX_CONTINUE;
776 
777 	if (ieee80211_hdrlen(hdr->frame_control) < 24)
778 		return TX_CONTINUE;
779 
780 	if (ieee80211_is_qos_nullfunc(hdr->frame_control))
781 		return TX_CONTINUE;
782 
783 	/*
784 	 * Anything but QoS data that has a sequence number field
785 	 * (is long enough) gets a sequence number from the global
786 	 * counter.  QoS data frames with a multicast destination
787 	 * also use the global counter (802.11-2012 9.3.2.10).
788 	 */
789 	if (!ieee80211_is_data_qos(hdr->frame_control) ||
790 	    is_multicast_ether_addr(hdr->addr1)) {
791 		/* driver should assign sequence number */
792 		info->flags |= IEEE80211_TX_CTL_ASSIGN_SEQ;
793 		/* for pure STA mode without beacons, we can do it */
794 		hdr->seq_ctrl = cpu_to_le16(tx->sdata->sequence_number);
795 		tx->sdata->sequence_number += 0x10;
796 		return TX_CONTINUE;
797 	}
798 
799 	/*
800 	 * This should be true for injected/management frames only, for
801 	 * management frames we have set the IEEE80211_TX_CTL_ASSIGN_SEQ
802 	 * above since they are not QoS-data frames.
803 	 */
804 	if (!tx->sta)
805 		return TX_CONTINUE;
806 
807 	/* include per-STA, per-TID sequence counter */
808 
809 	qc = ieee80211_get_qos_ctl(hdr);
810 	tid = *qc & IEEE80211_QOS_CTL_TID_MASK;
811 	seq = &tx->sta->tid_seq[tid];
812 
813 	hdr->seq_ctrl = cpu_to_le16(*seq);
814 
815 	/* Increase the sequence number. */
816 	*seq = (*seq + 0x10) & IEEE80211_SCTL_SEQ;
817 
818 	return TX_CONTINUE;
819 }
820 
821 static int ieee80211_fragment(struct ieee80211_tx_data *tx,
822 			      struct sk_buff *skb, int hdrlen,
823 			      int frag_threshold)
824 {
825 	struct ieee80211_local *local = tx->local;
826 	struct ieee80211_tx_info *info;
827 	struct sk_buff *tmp;
828 	int per_fragm = frag_threshold - hdrlen - FCS_LEN;
829 	int pos = hdrlen + per_fragm;
830 	int rem = skb->len - hdrlen - per_fragm;
831 
832 	if (WARN_ON(rem < 0))
833 		return -EINVAL;
834 
835 	/* first fragment was already added to queue by caller */
836 
837 	while (rem) {
838 		int fraglen = per_fragm;
839 
840 		if (fraglen > rem)
841 			fraglen = rem;
842 		rem -= fraglen;
843 		tmp = dev_alloc_skb(local->tx_headroom +
844 				    frag_threshold +
845 				    tx->sdata->encrypt_headroom +
846 				    IEEE80211_ENCRYPT_TAILROOM);
847 		if (!tmp)
848 			return -ENOMEM;
849 
850 		__skb_queue_tail(&tx->skbs, tmp);
851 
852 		skb_reserve(tmp,
853 			    local->tx_headroom + tx->sdata->encrypt_headroom);
854 
855 		/* copy control information */
856 		memcpy(tmp->cb, skb->cb, sizeof(tmp->cb));
857 
858 		info = IEEE80211_SKB_CB(tmp);
859 		info->flags &= ~(IEEE80211_TX_CTL_CLEAR_PS_FILT |
860 				 IEEE80211_TX_CTL_FIRST_FRAGMENT);
861 
862 		if (rem)
863 			info->flags |= IEEE80211_TX_CTL_MORE_FRAMES;
864 
865 		skb_copy_queue_mapping(tmp, skb);
866 		tmp->priority = skb->priority;
867 		tmp->dev = skb->dev;
868 
869 		/* copy header and data */
870 		memcpy(skb_put(tmp, hdrlen), skb->data, hdrlen);
871 		memcpy(skb_put(tmp, fraglen), skb->data + pos, fraglen);
872 
873 		pos += fraglen;
874 	}
875 
876 	/* adjust first fragment's length */
877 	skb->len = hdrlen + per_fragm;
878 	return 0;
879 }
880 
881 static ieee80211_tx_result debug_noinline
882 ieee80211_tx_h_fragment(struct ieee80211_tx_data *tx)
883 {
884 	struct sk_buff *skb = tx->skb;
885 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
886 	struct ieee80211_hdr *hdr = (void *)skb->data;
887 	int frag_threshold = tx->local->hw.wiphy->frag_threshold;
888 	int hdrlen;
889 	int fragnum;
890 
891 	/* no matter what happens, tx->skb moves to tx->skbs */
892 	__skb_queue_tail(&tx->skbs, skb);
893 	tx->skb = NULL;
894 
895 	if (info->flags & IEEE80211_TX_CTL_DONTFRAG)
896 		return TX_CONTINUE;
897 
898 	if (tx->local->ops->set_frag_threshold)
899 		return TX_CONTINUE;
900 
901 	/*
902 	 * Warn when submitting a fragmented A-MPDU frame and drop it.
903 	 * This scenario is handled in ieee80211_tx_prepare but extra
904 	 * caution taken here as fragmented ampdu may cause Tx stop.
905 	 */
906 	if (WARN_ON(info->flags & IEEE80211_TX_CTL_AMPDU))
907 		return TX_DROP;
908 
909 	hdrlen = ieee80211_hdrlen(hdr->frame_control);
910 
911 	/* internal error, why isn't DONTFRAG set? */
912 	if (WARN_ON(skb->len + FCS_LEN <= frag_threshold))
913 		return TX_DROP;
914 
915 	/*
916 	 * Now fragment the frame. This will allocate all the fragments and
917 	 * chain them (using skb as the first fragment) to skb->next.
918 	 * During transmission, we will remove the successfully transmitted
919 	 * fragments from this list. When the low-level driver rejects one
920 	 * of the fragments then we will simply pretend to accept the skb
921 	 * but store it away as pending.
922 	 */
923 	if (ieee80211_fragment(tx, skb, hdrlen, frag_threshold))
924 		return TX_DROP;
925 
926 	/* update duration/seq/flags of fragments */
927 	fragnum = 0;
928 
929 	skb_queue_walk(&tx->skbs, skb) {
930 		const __le16 morefrags = cpu_to_le16(IEEE80211_FCTL_MOREFRAGS);
931 
932 		hdr = (void *)skb->data;
933 		info = IEEE80211_SKB_CB(skb);
934 
935 		if (!skb_queue_is_last(&tx->skbs, skb)) {
936 			hdr->frame_control |= morefrags;
937 			/*
938 			 * No multi-rate retries for fragmented frames, that
939 			 * would completely throw off the NAV at other STAs.
940 			 */
941 			info->control.rates[1].idx = -1;
942 			info->control.rates[2].idx = -1;
943 			info->control.rates[3].idx = -1;
944 			BUILD_BUG_ON(IEEE80211_TX_MAX_RATES != 4);
945 			info->flags &= ~IEEE80211_TX_CTL_RATE_CTRL_PROBE;
946 		} else {
947 			hdr->frame_control &= ~morefrags;
948 		}
949 		hdr->seq_ctrl |= cpu_to_le16(fragnum & IEEE80211_SCTL_FRAG);
950 		fragnum++;
951 	}
952 
953 	return TX_CONTINUE;
954 }
955 
956 static ieee80211_tx_result debug_noinline
957 ieee80211_tx_h_stats(struct ieee80211_tx_data *tx)
958 {
959 	struct sk_buff *skb;
960 	int ac = -1;
961 
962 	if (!tx->sta)
963 		return TX_CONTINUE;
964 
965 	skb_queue_walk(&tx->skbs, skb) {
966 		ac = skb_get_queue_mapping(skb);
967 		tx->sta->tx_fragments++;
968 		tx->sta->tx_bytes[ac] += skb->len;
969 	}
970 	if (ac >= 0)
971 		tx->sta->tx_packets[ac]++;
972 
973 	return TX_CONTINUE;
974 }
975 
976 static ieee80211_tx_result debug_noinline
977 ieee80211_tx_h_encrypt(struct ieee80211_tx_data *tx)
978 {
979 	if (!tx->key)
980 		return TX_CONTINUE;
981 
982 	switch (tx->key->conf.cipher) {
983 	case WLAN_CIPHER_SUITE_WEP40:
984 	case WLAN_CIPHER_SUITE_WEP104:
985 		return ieee80211_crypto_wep_encrypt(tx);
986 	case WLAN_CIPHER_SUITE_TKIP:
987 		return ieee80211_crypto_tkip_encrypt(tx);
988 	case WLAN_CIPHER_SUITE_CCMP:
989 		return ieee80211_crypto_ccmp_encrypt(tx);
990 	case WLAN_CIPHER_SUITE_AES_CMAC:
991 		return ieee80211_crypto_aes_cmac_encrypt(tx);
992 	default:
993 		return ieee80211_crypto_hw_encrypt(tx);
994 	}
995 
996 	return TX_DROP;
997 }
998 
999 static ieee80211_tx_result debug_noinline
1000 ieee80211_tx_h_calculate_duration(struct ieee80211_tx_data *tx)
1001 {
1002 	struct sk_buff *skb;
1003 	struct ieee80211_hdr *hdr;
1004 	int next_len;
1005 	bool group_addr;
1006 
1007 	skb_queue_walk(&tx->skbs, skb) {
1008 		hdr = (void *) skb->data;
1009 		if (unlikely(ieee80211_is_pspoll(hdr->frame_control)))
1010 			break; /* must not overwrite AID */
1011 		if (!skb_queue_is_last(&tx->skbs, skb)) {
1012 			struct sk_buff *next = skb_queue_next(&tx->skbs, skb);
1013 			next_len = next->len;
1014 		} else
1015 			next_len = 0;
1016 		group_addr = is_multicast_ether_addr(hdr->addr1);
1017 
1018 		hdr->duration_id =
1019 			ieee80211_duration(tx, skb, group_addr, next_len);
1020 	}
1021 
1022 	return TX_CONTINUE;
1023 }
1024 
1025 /* actual transmit path */
1026 
1027 static bool ieee80211_tx_prep_agg(struct ieee80211_tx_data *tx,
1028 				  struct sk_buff *skb,
1029 				  struct ieee80211_tx_info *info,
1030 				  struct tid_ampdu_tx *tid_tx,
1031 				  int tid)
1032 {
1033 	bool queued = false;
1034 	bool reset_agg_timer = false;
1035 	struct sk_buff *purge_skb = NULL;
1036 
1037 	if (test_bit(HT_AGG_STATE_OPERATIONAL, &tid_tx->state)) {
1038 		info->flags |= IEEE80211_TX_CTL_AMPDU;
1039 		reset_agg_timer = true;
1040 	} else if (test_bit(HT_AGG_STATE_WANT_START, &tid_tx->state)) {
1041 		/*
1042 		 * nothing -- this aggregation session is being started
1043 		 * but that might still fail with the driver
1044 		 */
1045 	} else {
1046 		spin_lock(&tx->sta->lock);
1047 		/*
1048 		 * Need to re-check now, because we may get here
1049 		 *
1050 		 *  1) in the window during which the setup is actually
1051 		 *     already done, but not marked yet because not all
1052 		 *     packets are spliced over to the driver pending
1053 		 *     queue yet -- if this happened we acquire the lock
1054 		 *     either before or after the splice happens, but
1055 		 *     need to recheck which of these cases happened.
1056 		 *
1057 		 *  2) during session teardown, if the OPERATIONAL bit
1058 		 *     was cleared due to the teardown but the pointer
1059 		 *     hasn't been assigned NULL yet (or we loaded it
1060 		 *     before it was assigned) -- in this case it may
1061 		 *     now be NULL which means we should just let the
1062 		 *     packet pass through because splicing the frames
1063 		 *     back is already done.
1064 		 */
1065 		tid_tx = rcu_dereference_protected_tid_tx(tx->sta, tid);
1066 
1067 		if (!tid_tx) {
1068 			/* do nothing, let packet pass through */
1069 		} else if (test_bit(HT_AGG_STATE_OPERATIONAL, &tid_tx->state)) {
1070 			info->flags |= IEEE80211_TX_CTL_AMPDU;
1071 			reset_agg_timer = true;
1072 		} else {
1073 			queued = true;
1074 			info->control.vif = &tx->sdata->vif;
1075 			info->flags |= IEEE80211_TX_INTFL_NEED_TXPROCESSING;
1076 			__skb_queue_tail(&tid_tx->pending, skb);
1077 			if (skb_queue_len(&tid_tx->pending) > STA_MAX_TX_BUFFER)
1078 				purge_skb = __skb_dequeue(&tid_tx->pending);
1079 		}
1080 		spin_unlock(&tx->sta->lock);
1081 
1082 		if (purge_skb)
1083 			ieee80211_free_txskb(&tx->local->hw, purge_skb);
1084 	}
1085 
1086 	/* reset session timer */
1087 	if (reset_agg_timer && tid_tx->timeout)
1088 		tid_tx->last_tx = jiffies;
1089 
1090 	return queued;
1091 }
1092 
1093 /*
1094  * initialises @tx
1095  */
1096 static ieee80211_tx_result
1097 ieee80211_tx_prepare(struct ieee80211_sub_if_data *sdata,
1098 		     struct ieee80211_tx_data *tx,
1099 		     struct sk_buff *skb)
1100 {
1101 	struct ieee80211_local *local = sdata->local;
1102 	struct ieee80211_hdr *hdr;
1103 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
1104 	int tid;
1105 	u8 *qc;
1106 
1107 	memset(tx, 0, sizeof(*tx));
1108 	tx->skb = skb;
1109 	tx->local = local;
1110 	tx->sdata = sdata;
1111 	__skb_queue_head_init(&tx->skbs);
1112 
1113 	/*
1114 	 * If this flag is set to true anywhere, and we get here,
1115 	 * we are doing the needed processing, so remove the flag
1116 	 * now.
1117 	 */
1118 	info->flags &= ~IEEE80211_TX_INTFL_NEED_TXPROCESSING;
1119 
1120 	hdr = (struct ieee80211_hdr *) skb->data;
1121 
1122 	if (sdata->vif.type == NL80211_IFTYPE_AP_VLAN) {
1123 		tx->sta = rcu_dereference(sdata->u.vlan.sta);
1124 		if (!tx->sta && sdata->dev->ieee80211_ptr->use_4addr)
1125 			return TX_DROP;
1126 	} else if (info->flags & (IEEE80211_TX_CTL_INJECTED |
1127 				  IEEE80211_TX_INTFL_NL80211_FRAME_TX) ||
1128 		   tx->sdata->control_port_protocol == tx->skb->protocol) {
1129 		tx->sta = sta_info_get_bss(sdata, hdr->addr1);
1130 	}
1131 	if (!tx->sta)
1132 		tx->sta = sta_info_get(sdata, hdr->addr1);
1133 
1134 	if (tx->sta && ieee80211_is_data_qos(hdr->frame_control) &&
1135 	    !ieee80211_is_qos_nullfunc(hdr->frame_control) &&
1136 	    (local->hw.flags & IEEE80211_HW_AMPDU_AGGREGATION) &&
1137 	    !(local->hw.flags & IEEE80211_HW_TX_AMPDU_SETUP_IN_HW)) {
1138 		struct tid_ampdu_tx *tid_tx;
1139 
1140 		qc = ieee80211_get_qos_ctl(hdr);
1141 		tid = *qc & IEEE80211_QOS_CTL_TID_MASK;
1142 
1143 		tid_tx = rcu_dereference(tx->sta->ampdu_mlme.tid_tx[tid]);
1144 		if (tid_tx) {
1145 			bool queued;
1146 
1147 			queued = ieee80211_tx_prep_agg(tx, skb, info,
1148 						       tid_tx, tid);
1149 
1150 			if (unlikely(queued))
1151 				return TX_QUEUED;
1152 		}
1153 	}
1154 
1155 	if (is_multicast_ether_addr(hdr->addr1)) {
1156 		tx->flags &= ~IEEE80211_TX_UNICAST;
1157 		info->flags |= IEEE80211_TX_CTL_NO_ACK;
1158 	} else
1159 		tx->flags |= IEEE80211_TX_UNICAST;
1160 
1161 	if (!(info->flags & IEEE80211_TX_CTL_DONTFRAG)) {
1162 		if (!(tx->flags & IEEE80211_TX_UNICAST) ||
1163 		    skb->len + FCS_LEN <= local->hw.wiphy->frag_threshold ||
1164 		    info->flags & IEEE80211_TX_CTL_AMPDU)
1165 			info->flags |= IEEE80211_TX_CTL_DONTFRAG;
1166 	}
1167 
1168 	if (!tx->sta)
1169 		info->flags |= IEEE80211_TX_CTL_CLEAR_PS_FILT;
1170 	else if (test_and_clear_sta_flag(tx->sta, WLAN_STA_CLEAR_PS_FILT))
1171 		info->flags |= IEEE80211_TX_CTL_CLEAR_PS_FILT;
1172 
1173 	info->flags |= IEEE80211_TX_CTL_FIRST_FRAGMENT;
1174 
1175 	return TX_CONTINUE;
1176 }
1177 
1178 static bool ieee80211_tx_frags(struct ieee80211_local *local,
1179 			       struct ieee80211_vif *vif,
1180 			       struct ieee80211_sta *sta,
1181 			       struct sk_buff_head *skbs,
1182 			       bool txpending)
1183 {
1184 	struct ieee80211_tx_control control;
1185 	struct sk_buff *skb, *tmp;
1186 	unsigned long flags;
1187 
1188 	skb_queue_walk_safe(skbs, skb, tmp) {
1189 		struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
1190 		int q = info->hw_queue;
1191 
1192 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG
1193 		if (WARN_ON_ONCE(q >= local->hw.queues)) {
1194 			__skb_unlink(skb, skbs);
1195 			ieee80211_free_txskb(&local->hw, skb);
1196 			continue;
1197 		}
1198 #endif
1199 
1200 		spin_lock_irqsave(&local->queue_stop_reason_lock, flags);
1201 		if (local->queue_stop_reasons[q] ||
1202 		    (!txpending && !skb_queue_empty(&local->pending[q]))) {
1203 			if (unlikely(info->flags &
1204 				     IEEE80211_TX_INTFL_OFFCHAN_TX_OK)) {
1205 				if (local->queue_stop_reasons[q] &
1206 				    ~BIT(IEEE80211_QUEUE_STOP_REASON_OFFCHANNEL)) {
1207 					/*
1208 					 * Drop off-channel frames if queues
1209 					 * are stopped for any reason other
1210 					 * than off-channel operation. Never
1211 					 * queue them.
1212 					 */
1213 					spin_unlock_irqrestore(
1214 						&local->queue_stop_reason_lock,
1215 						flags);
1216 					ieee80211_purge_tx_queue(&local->hw,
1217 								 skbs);
1218 					return true;
1219 				}
1220 			} else {
1221 
1222 				/*
1223 				 * Since queue is stopped, queue up frames for
1224 				 * later transmission from the tx-pending
1225 				 * tasklet when the queue is woken again.
1226 				 */
1227 				if (txpending)
1228 					skb_queue_splice_init(skbs,
1229 							      &local->pending[q]);
1230 				else
1231 					skb_queue_splice_tail_init(skbs,
1232 								   &local->pending[q]);
1233 
1234 				spin_unlock_irqrestore(&local->queue_stop_reason_lock,
1235 						       flags);
1236 				return false;
1237 			}
1238 		}
1239 		spin_unlock_irqrestore(&local->queue_stop_reason_lock, flags);
1240 
1241 		info->control.vif = vif;
1242 		control.sta = sta;
1243 
1244 		__skb_unlink(skb, skbs);
1245 		drv_tx(local, &control, skb);
1246 	}
1247 
1248 	return true;
1249 }
1250 
1251 /*
1252  * Returns false if the frame couldn't be transmitted but was queued instead.
1253  */
1254 static bool __ieee80211_tx(struct ieee80211_local *local,
1255 			   struct sk_buff_head *skbs, int led_len,
1256 			   struct sta_info *sta, bool txpending)
1257 {
1258 	struct ieee80211_tx_info *info;
1259 	struct ieee80211_sub_if_data *sdata;
1260 	struct ieee80211_vif *vif;
1261 	struct ieee80211_sta *pubsta;
1262 	struct sk_buff *skb;
1263 	bool result = true;
1264 	__le16 fc;
1265 
1266 	if (WARN_ON(skb_queue_empty(skbs)))
1267 		return true;
1268 
1269 	skb = skb_peek(skbs);
1270 	fc = ((struct ieee80211_hdr *)skb->data)->frame_control;
1271 	info = IEEE80211_SKB_CB(skb);
1272 	sdata = vif_to_sdata(info->control.vif);
1273 	if (sta && !sta->uploaded)
1274 		sta = NULL;
1275 
1276 	if (sta)
1277 		pubsta = &sta->sta;
1278 	else
1279 		pubsta = NULL;
1280 
1281 	switch (sdata->vif.type) {
1282 	case NL80211_IFTYPE_MONITOR:
1283 		if (sdata->u.mntr_flags & MONITOR_FLAG_ACTIVE) {
1284 			vif = &sdata->vif;
1285 			break;
1286 		}
1287 		sdata = rcu_dereference(local->monitor_sdata);
1288 		if (sdata) {
1289 			vif = &sdata->vif;
1290 			info->hw_queue =
1291 				vif->hw_queue[skb_get_queue_mapping(skb)];
1292 		} else if (local->hw.flags & IEEE80211_HW_QUEUE_CONTROL) {
1293 			dev_kfree_skb(skb);
1294 			return true;
1295 		} else
1296 			vif = NULL;
1297 		break;
1298 	case NL80211_IFTYPE_AP_VLAN:
1299 		sdata = container_of(sdata->bss,
1300 				     struct ieee80211_sub_if_data, u.ap);
1301 		/* fall through */
1302 	default:
1303 		vif = &sdata->vif;
1304 		break;
1305 	}
1306 
1307 	result = ieee80211_tx_frags(local, vif, pubsta, skbs,
1308 				    txpending);
1309 
1310 	ieee80211_tpt_led_trig_tx(local, fc, led_len);
1311 
1312 	WARN_ON_ONCE(!skb_queue_empty(skbs));
1313 
1314 	return result;
1315 }
1316 
1317 /*
1318  * Invoke TX handlers, return 0 on success and non-zero if the
1319  * frame was dropped or queued.
1320  */
1321 static int invoke_tx_handlers(struct ieee80211_tx_data *tx)
1322 {
1323 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(tx->skb);
1324 	ieee80211_tx_result res = TX_DROP;
1325 
1326 #define CALL_TXH(txh) \
1327 	do {				\
1328 		res = txh(tx);		\
1329 		if (res != TX_CONTINUE)	\
1330 			goto txh_done;	\
1331 	} while (0)
1332 
1333 	CALL_TXH(ieee80211_tx_h_dynamic_ps);
1334 	CALL_TXH(ieee80211_tx_h_check_assoc);
1335 	CALL_TXH(ieee80211_tx_h_ps_buf);
1336 	CALL_TXH(ieee80211_tx_h_check_control_port_protocol);
1337 	CALL_TXH(ieee80211_tx_h_select_key);
1338 	if (!(tx->local->hw.flags & IEEE80211_HW_HAS_RATE_CONTROL))
1339 		CALL_TXH(ieee80211_tx_h_rate_ctrl);
1340 
1341 	if (unlikely(info->flags & IEEE80211_TX_INTFL_RETRANSMISSION)) {
1342 		__skb_queue_tail(&tx->skbs, tx->skb);
1343 		tx->skb = NULL;
1344 		goto txh_done;
1345 	}
1346 
1347 	CALL_TXH(ieee80211_tx_h_michael_mic_add);
1348 	CALL_TXH(ieee80211_tx_h_sequence);
1349 	CALL_TXH(ieee80211_tx_h_fragment);
1350 	/* handlers after fragment must be aware of tx info fragmentation! */
1351 	CALL_TXH(ieee80211_tx_h_stats);
1352 	CALL_TXH(ieee80211_tx_h_encrypt);
1353 	if (!(tx->local->hw.flags & IEEE80211_HW_HAS_RATE_CONTROL))
1354 		CALL_TXH(ieee80211_tx_h_calculate_duration);
1355 #undef CALL_TXH
1356 
1357  txh_done:
1358 	if (unlikely(res == TX_DROP)) {
1359 		I802_DEBUG_INC(tx->local->tx_handlers_drop);
1360 		if (tx->skb)
1361 			ieee80211_free_txskb(&tx->local->hw, tx->skb);
1362 		else
1363 			ieee80211_purge_tx_queue(&tx->local->hw, &tx->skbs);
1364 		return -1;
1365 	} else if (unlikely(res == TX_QUEUED)) {
1366 		I802_DEBUG_INC(tx->local->tx_handlers_queued);
1367 		return -1;
1368 	}
1369 
1370 	return 0;
1371 }
1372 
1373 bool ieee80211_tx_prepare_skb(struct ieee80211_hw *hw,
1374 			      struct ieee80211_vif *vif, struct sk_buff *skb,
1375 			      int band, struct ieee80211_sta **sta)
1376 {
1377 	struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
1378 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
1379 	struct ieee80211_tx_data tx;
1380 
1381 	if (ieee80211_tx_prepare(sdata, &tx, skb) == TX_DROP)
1382 		return false;
1383 
1384 	info->band = band;
1385 	info->control.vif = vif;
1386 	info->hw_queue = vif->hw_queue[skb_get_queue_mapping(skb)];
1387 
1388 	if (invoke_tx_handlers(&tx))
1389 		return false;
1390 
1391 	if (sta) {
1392 		if (tx.sta)
1393 			*sta = &tx.sta->sta;
1394 		else
1395 			*sta = NULL;
1396 	}
1397 
1398 	return true;
1399 }
1400 EXPORT_SYMBOL(ieee80211_tx_prepare_skb);
1401 
1402 /*
1403  * Returns false if the frame couldn't be transmitted but was queued instead.
1404  */
1405 static bool ieee80211_tx(struct ieee80211_sub_if_data *sdata,
1406 			 struct sk_buff *skb, bool txpending,
1407 			 enum ieee80211_band band)
1408 {
1409 	struct ieee80211_local *local = sdata->local;
1410 	struct ieee80211_tx_data tx;
1411 	ieee80211_tx_result res_prepare;
1412 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
1413 	bool result = true;
1414 	int led_len;
1415 
1416 	if (unlikely(skb->len < 10)) {
1417 		dev_kfree_skb(skb);
1418 		return true;
1419 	}
1420 
1421 	/* initialises tx */
1422 	led_len = skb->len;
1423 	res_prepare = ieee80211_tx_prepare(sdata, &tx, skb);
1424 
1425 	if (unlikely(res_prepare == TX_DROP)) {
1426 		ieee80211_free_txskb(&local->hw, skb);
1427 		return true;
1428 	} else if (unlikely(res_prepare == TX_QUEUED)) {
1429 		return true;
1430 	}
1431 
1432 	info->band = band;
1433 
1434 	/* set up hw_queue value early */
1435 	if (!(info->flags & IEEE80211_TX_CTL_TX_OFFCHAN) ||
1436 	    !(local->hw.flags & IEEE80211_HW_QUEUE_CONTROL))
1437 		info->hw_queue =
1438 			sdata->vif.hw_queue[skb_get_queue_mapping(skb)];
1439 
1440 	if (!invoke_tx_handlers(&tx))
1441 		result = __ieee80211_tx(local, &tx.skbs, led_len,
1442 					tx.sta, txpending);
1443 
1444 	return result;
1445 }
1446 
1447 /* device xmit handlers */
1448 
1449 static int ieee80211_skb_resize(struct ieee80211_sub_if_data *sdata,
1450 				struct sk_buff *skb,
1451 				int head_need, bool may_encrypt)
1452 {
1453 	struct ieee80211_local *local = sdata->local;
1454 	int tail_need = 0;
1455 
1456 	if (may_encrypt && sdata->crypto_tx_tailroom_needed_cnt) {
1457 		tail_need = IEEE80211_ENCRYPT_TAILROOM;
1458 		tail_need -= skb_tailroom(skb);
1459 		tail_need = max_t(int, tail_need, 0);
1460 	}
1461 
1462 	if (skb_cloned(skb))
1463 		I802_DEBUG_INC(local->tx_expand_skb_head_cloned);
1464 	else if (head_need || tail_need)
1465 		I802_DEBUG_INC(local->tx_expand_skb_head);
1466 	else
1467 		return 0;
1468 
1469 	if (pskb_expand_head(skb, head_need, tail_need, GFP_ATOMIC)) {
1470 		wiphy_debug(local->hw.wiphy,
1471 			    "failed to reallocate TX buffer\n");
1472 		return -ENOMEM;
1473 	}
1474 
1475 	return 0;
1476 }
1477 
1478 void ieee80211_xmit(struct ieee80211_sub_if_data *sdata, struct sk_buff *skb,
1479 		    enum ieee80211_band band)
1480 {
1481 	struct ieee80211_local *local = sdata->local;
1482 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
1483 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
1484 	int headroom;
1485 	bool may_encrypt;
1486 
1487 	may_encrypt = !(info->flags & IEEE80211_TX_INTFL_DONT_ENCRYPT);
1488 
1489 	headroom = local->tx_headroom;
1490 	if (may_encrypt)
1491 		headroom += sdata->encrypt_headroom;
1492 	headroom -= skb_headroom(skb);
1493 	headroom = max_t(int, 0, headroom);
1494 
1495 	if (ieee80211_skb_resize(sdata, skb, headroom, may_encrypt)) {
1496 		ieee80211_free_txskb(&local->hw, skb);
1497 		return;
1498 	}
1499 
1500 	hdr = (struct ieee80211_hdr *) skb->data;
1501 	info->control.vif = &sdata->vif;
1502 
1503 	if (ieee80211_vif_is_mesh(&sdata->vif)) {
1504 		if (ieee80211_is_data(hdr->frame_control) &&
1505 		    is_unicast_ether_addr(hdr->addr1)) {
1506 			if (mesh_nexthop_resolve(sdata, skb))
1507 				return; /* skb queued: don't free */
1508 		} else {
1509 			ieee80211_mps_set_frame_flags(sdata, NULL, hdr);
1510 		}
1511 	}
1512 
1513 	ieee80211_set_qos_hdr(sdata, skb);
1514 	ieee80211_tx(sdata, skb, false, band);
1515 }
1516 
1517 static bool ieee80211_parse_tx_radiotap(struct sk_buff *skb)
1518 {
1519 	struct ieee80211_radiotap_iterator iterator;
1520 	struct ieee80211_radiotap_header *rthdr =
1521 		(struct ieee80211_radiotap_header *) skb->data;
1522 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
1523 	int ret = ieee80211_radiotap_iterator_init(&iterator, rthdr, skb->len,
1524 						   NULL);
1525 	u16 txflags;
1526 
1527 	info->flags |= IEEE80211_TX_INTFL_DONT_ENCRYPT |
1528 		       IEEE80211_TX_CTL_DONTFRAG;
1529 
1530 	/*
1531 	 * for every radiotap entry that is present
1532 	 * (ieee80211_radiotap_iterator_next returns -ENOENT when no more
1533 	 * entries present, or -EINVAL on error)
1534 	 */
1535 
1536 	while (!ret) {
1537 		ret = ieee80211_radiotap_iterator_next(&iterator);
1538 
1539 		if (ret)
1540 			continue;
1541 
1542 		/* see if this argument is something we can use */
1543 		switch (iterator.this_arg_index) {
1544 		/*
1545 		 * You must take care when dereferencing iterator.this_arg
1546 		 * for multibyte types... the pointer is not aligned.  Use
1547 		 * get_unaligned((type *)iterator.this_arg) to dereference
1548 		 * iterator.this_arg for type "type" safely on all arches.
1549 		*/
1550 		case IEEE80211_RADIOTAP_FLAGS:
1551 			if (*iterator.this_arg & IEEE80211_RADIOTAP_F_FCS) {
1552 				/*
1553 				 * this indicates that the skb we have been
1554 				 * handed has the 32-bit FCS CRC at the end...
1555 				 * we should react to that by snipping it off
1556 				 * because it will be recomputed and added
1557 				 * on transmission
1558 				 */
1559 				if (skb->len < (iterator._max_length + FCS_LEN))
1560 					return false;
1561 
1562 				skb_trim(skb, skb->len - FCS_LEN);
1563 			}
1564 			if (*iterator.this_arg & IEEE80211_RADIOTAP_F_WEP)
1565 				info->flags &= ~IEEE80211_TX_INTFL_DONT_ENCRYPT;
1566 			if (*iterator.this_arg & IEEE80211_RADIOTAP_F_FRAG)
1567 				info->flags &= ~IEEE80211_TX_CTL_DONTFRAG;
1568 			break;
1569 
1570 		case IEEE80211_RADIOTAP_TX_FLAGS:
1571 			txflags = get_unaligned_le16(iterator.this_arg);
1572 			if (txflags & IEEE80211_RADIOTAP_F_TX_NOACK)
1573 				info->flags |= IEEE80211_TX_CTL_NO_ACK;
1574 			break;
1575 
1576 		/*
1577 		 * Please update the file
1578 		 * Documentation/networking/mac80211-injection.txt
1579 		 * when parsing new fields here.
1580 		 */
1581 
1582 		default:
1583 			break;
1584 		}
1585 	}
1586 
1587 	if (ret != -ENOENT) /* ie, if we didn't simply run out of fields */
1588 		return false;
1589 
1590 	/*
1591 	 * remove the radiotap header
1592 	 * iterator->_max_length was sanity-checked against
1593 	 * skb->len by iterator init
1594 	 */
1595 	skb_pull(skb, iterator._max_length);
1596 
1597 	return true;
1598 }
1599 
1600 netdev_tx_t ieee80211_monitor_start_xmit(struct sk_buff *skb,
1601 					 struct net_device *dev)
1602 {
1603 	struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
1604 	struct ieee80211_chanctx_conf *chanctx_conf;
1605 	struct ieee80211_channel *chan;
1606 	struct ieee80211_radiotap_header *prthdr =
1607 		(struct ieee80211_radiotap_header *)skb->data;
1608 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
1609 	struct ieee80211_hdr *hdr;
1610 	struct ieee80211_sub_if_data *tmp_sdata, *sdata;
1611 	u16 len_rthdr;
1612 	int hdrlen;
1613 
1614 	/* check for not even having the fixed radiotap header part */
1615 	if (unlikely(skb->len < sizeof(struct ieee80211_radiotap_header)))
1616 		goto fail; /* too short to be possibly valid */
1617 
1618 	/* is it a header version we can trust to find length from? */
1619 	if (unlikely(prthdr->it_version))
1620 		goto fail; /* only version 0 is supported */
1621 
1622 	/* then there must be a radiotap header with a length we can use */
1623 	len_rthdr = ieee80211_get_radiotap_len(skb->data);
1624 
1625 	/* does the skb contain enough to deliver on the alleged length? */
1626 	if (unlikely(skb->len < len_rthdr))
1627 		goto fail; /* skb too short for claimed rt header extent */
1628 
1629 	/*
1630 	 * fix up the pointers accounting for the radiotap
1631 	 * header still being in there.  We are being given
1632 	 * a precooked IEEE80211 header so no need for
1633 	 * normal processing
1634 	 */
1635 	skb_set_mac_header(skb, len_rthdr);
1636 	/*
1637 	 * these are just fixed to the end of the rt area since we
1638 	 * don't have any better information and at this point, nobody cares
1639 	 */
1640 	skb_set_network_header(skb, len_rthdr);
1641 	skb_set_transport_header(skb, len_rthdr);
1642 
1643 	if (skb->len < len_rthdr + 2)
1644 		goto fail;
1645 
1646 	hdr = (struct ieee80211_hdr *)(skb->data + len_rthdr);
1647 	hdrlen = ieee80211_hdrlen(hdr->frame_control);
1648 
1649 	if (skb->len < len_rthdr + hdrlen)
1650 		goto fail;
1651 
1652 	/*
1653 	 * Initialize skb->protocol if the injected frame is a data frame
1654 	 * carrying a rfc1042 header
1655 	 */
1656 	if (ieee80211_is_data(hdr->frame_control) &&
1657 	    skb->len >= len_rthdr + hdrlen + sizeof(rfc1042_header) + 2) {
1658 		u8 *payload = (u8 *)hdr + hdrlen;
1659 
1660 		if (ether_addr_equal(payload, rfc1042_header))
1661 			skb->protocol = cpu_to_be16((payload[6] << 8) |
1662 						    payload[7]);
1663 	}
1664 
1665 	memset(info, 0, sizeof(*info));
1666 
1667 	info->flags = IEEE80211_TX_CTL_REQ_TX_STATUS |
1668 		      IEEE80211_TX_CTL_INJECTED;
1669 
1670 	/* process and remove the injection radiotap header */
1671 	if (!ieee80211_parse_tx_radiotap(skb))
1672 		goto fail;
1673 
1674 	rcu_read_lock();
1675 
1676 	/*
1677 	 * We process outgoing injected frames that have a local address
1678 	 * we handle as though they are non-injected frames.
1679 	 * This code here isn't entirely correct, the local MAC address
1680 	 * isn't always enough to find the interface to use; for proper
1681 	 * VLAN/WDS support we will need a different mechanism (which
1682 	 * likely isn't going to be monitor interfaces).
1683 	 */
1684 	sdata = IEEE80211_DEV_TO_SUB_IF(dev);
1685 
1686 	list_for_each_entry_rcu(tmp_sdata, &local->interfaces, list) {
1687 		if (!ieee80211_sdata_running(tmp_sdata))
1688 			continue;
1689 		if (tmp_sdata->vif.type == NL80211_IFTYPE_MONITOR ||
1690 		    tmp_sdata->vif.type == NL80211_IFTYPE_AP_VLAN ||
1691 		    tmp_sdata->vif.type == NL80211_IFTYPE_WDS)
1692 			continue;
1693 		if (ether_addr_equal(tmp_sdata->vif.addr, hdr->addr2)) {
1694 			sdata = tmp_sdata;
1695 			break;
1696 		}
1697 	}
1698 
1699 	chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);
1700 	if (!chanctx_conf) {
1701 		tmp_sdata = rcu_dereference(local->monitor_sdata);
1702 		if (tmp_sdata)
1703 			chanctx_conf =
1704 				rcu_dereference(tmp_sdata->vif.chanctx_conf);
1705 	}
1706 
1707 	if (chanctx_conf)
1708 		chan = chanctx_conf->def.chan;
1709 	else if (!local->use_chanctx)
1710 		chan = local->_oper_chandef.chan;
1711 	else
1712 		goto fail_rcu;
1713 
1714 	/*
1715 	 * Frame injection is not allowed if beaconing is not allowed
1716 	 * or if we need radar detection. Beaconing is usually not allowed when
1717 	 * the mode or operation (Adhoc, AP, Mesh) does not support DFS.
1718 	 * Passive scan is also used in world regulatory domains where
1719 	 * your country is not known and as such it should be treated as
1720 	 * NO TX unless the channel is explicitly allowed in which case
1721 	 * your current regulatory domain would not have the passive scan
1722 	 * flag.
1723 	 *
1724 	 * Since AP mode uses monitor interfaces to inject/TX management
1725 	 * frames we can make AP mode the exception to this rule once it
1726 	 * supports radar detection as its implementation can deal with
1727 	 * radar detection by itself. We can do that later by adding a
1728 	 * monitor flag interfaces used for AP support.
1729 	 */
1730 	if ((chan->flags & (IEEE80211_CHAN_NO_IR | IEEE80211_CHAN_RADAR)))
1731 		goto fail_rcu;
1732 
1733 	ieee80211_xmit(sdata, skb, chan->band);
1734 	rcu_read_unlock();
1735 
1736 	return NETDEV_TX_OK;
1737 
1738 fail_rcu:
1739 	rcu_read_unlock();
1740 fail:
1741 	dev_kfree_skb(skb);
1742 	return NETDEV_TX_OK; /* meaning, we dealt with the skb */
1743 }
1744 
1745 /*
1746  * Measure Tx frame arrival time for Tx latency statistics calculation
1747  * A single Tx frame latency should be measured from when it is entering the
1748  * Kernel until we receive Tx complete confirmation indication and the skb is
1749  * freed.
1750  */
1751 static void ieee80211_tx_latency_start_msrmnt(struct ieee80211_local *local,
1752 					      struct sk_buff *skb)
1753 {
1754 	struct timespec skb_arv;
1755 	struct ieee80211_tx_latency_bin_ranges *tx_latency;
1756 
1757 	tx_latency = rcu_dereference(local->tx_latency);
1758 	if (!tx_latency)
1759 		return;
1760 
1761 	ktime_get_ts(&skb_arv);
1762 	skb->tstamp = ktime_set(skb_arv.tv_sec, skb_arv.tv_nsec);
1763 }
1764 
1765 /**
1766  * ieee80211_subif_start_xmit - netif start_xmit function for Ethernet-type
1767  * subinterfaces (wlan#, WDS, and VLAN interfaces)
1768  * @skb: packet to be sent
1769  * @dev: incoming interface
1770  *
1771  * Returns: 0 on success (and frees skb in this case) or 1 on failure (skb will
1772  * not be freed, and caller is responsible for either retrying later or freeing
1773  * skb).
1774  *
1775  * This function takes in an Ethernet header and encapsulates it with suitable
1776  * IEEE 802.11 header based on which interface the packet is coming in. The
1777  * encapsulated packet will then be passed to master interface, wlan#.11, for
1778  * transmission (through low-level driver).
1779  */
1780 netdev_tx_t ieee80211_subif_start_xmit(struct sk_buff *skb,
1781 				    struct net_device *dev)
1782 {
1783 	struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
1784 	struct ieee80211_local *local = sdata->local;
1785 	struct ieee80211_tx_info *info;
1786 	int head_need;
1787 	u16 ethertype, hdrlen,  meshhdrlen = 0;
1788 	__le16 fc;
1789 	struct ieee80211_hdr hdr;
1790 	struct ieee80211s_hdr mesh_hdr __maybe_unused;
1791 	struct mesh_path __maybe_unused *mppath = NULL, *mpath = NULL;
1792 	const u8 *encaps_data;
1793 	int encaps_len, skip_header_bytes;
1794 	int nh_pos, h_pos;
1795 	struct sta_info *sta = NULL;
1796 	bool wme_sta = false, authorized = false, tdls_auth = false;
1797 	bool tdls_direct = false;
1798 	bool multicast;
1799 	u32 info_flags = 0;
1800 	u16 info_id = 0;
1801 	struct ieee80211_chanctx_conf *chanctx_conf;
1802 	struct ieee80211_sub_if_data *ap_sdata;
1803 	enum ieee80211_band band;
1804 
1805 	if (unlikely(skb->len < ETH_HLEN))
1806 		goto fail;
1807 
1808 	/* convert Ethernet header to proper 802.11 header (based on
1809 	 * operation mode) */
1810 	ethertype = (skb->data[12] << 8) | skb->data[13];
1811 	fc = cpu_to_le16(IEEE80211_FTYPE_DATA | IEEE80211_STYPE_DATA);
1812 
1813 	rcu_read_lock();
1814 
1815 	/* Measure frame arrival for Tx latency statistics calculation */
1816 	ieee80211_tx_latency_start_msrmnt(local, skb);
1817 
1818 	switch (sdata->vif.type) {
1819 	case NL80211_IFTYPE_AP_VLAN:
1820 		sta = rcu_dereference(sdata->u.vlan.sta);
1821 		if (sta) {
1822 			fc |= cpu_to_le16(IEEE80211_FCTL_FROMDS | IEEE80211_FCTL_TODS);
1823 			/* RA TA DA SA */
1824 			memcpy(hdr.addr1, sta->sta.addr, ETH_ALEN);
1825 			memcpy(hdr.addr2, sdata->vif.addr, ETH_ALEN);
1826 			memcpy(hdr.addr3, skb->data, ETH_ALEN);
1827 			memcpy(hdr.addr4, skb->data + ETH_ALEN, ETH_ALEN);
1828 			hdrlen = 30;
1829 			authorized = test_sta_flag(sta, WLAN_STA_AUTHORIZED);
1830 			wme_sta = test_sta_flag(sta, WLAN_STA_WME);
1831 		}
1832 		ap_sdata = container_of(sdata->bss, struct ieee80211_sub_if_data,
1833 					u.ap);
1834 		chanctx_conf = rcu_dereference(ap_sdata->vif.chanctx_conf);
1835 		if (!chanctx_conf)
1836 			goto fail_rcu;
1837 		band = chanctx_conf->def.chan->band;
1838 		if (sta)
1839 			break;
1840 		/* fall through */
1841 	case NL80211_IFTYPE_AP:
1842 		if (sdata->vif.type == NL80211_IFTYPE_AP)
1843 			chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);
1844 		if (!chanctx_conf)
1845 			goto fail_rcu;
1846 		fc |= cpu_to_le16(IEEE80211_FCTL_FROMDS);
1847 		/* DA BSSID SA */
1848 		memcpy(hdr.addr1, skb->data, ETH_ALEN);
1849 		memcpy(hdr.addr2, sdata->vif.addr, ETH_ALEN);
1850 		memcpy(hdr.addr3, skb->data + ETH_ALEN, ETH_ALEN);
1851 		hdrlen = 24;
1852 		band = chanctx_conf->def.chan->band;
1853 		break;
1854 	case NL80211_IFTYPE_WDS:
1855 		fc |= cpu_to_le16(IEEE80211_FCTL_FROMDS | IEEE80211_FCTL_TODS);
1856 		/* RA TA DA SA */
1857 		memcpy(hdr.addr1, sdata->u.wds.remote_addr, ETH_ALEN);
1858 		memcpy(hdr.addr2, sdata->vif.addr, ETH_ALEN);
1859 		memcpy(hdr.addr3, skb->data, ETH_ALEN);
1860 		memcpy(hdr.addr4, skb->data + ETH_ALEN, ETH_ALEN);
1861 		hdrlen = 30;
1862 		/*
1863 		 * This is the exception! WDS style interfaces are prohibited
1864 		 * when channel contexts are in used so this must be valid
1865 		 */
1866 		band = local->hw.conf.chandef.chan->band;
1867 		break;
1868 #ifdef CONFIG_MAC80211_MESH
1869 	case NL80211_IFTYPE_MESH_POINT:
1870 		if (!is_multicast_ether_addr(skb->data)) {
1871 			struct sta_info *next_hop;
1872 			bool mpp_lookup = true;
1873 
1874 			mpath = mesh_path_lookup(sdata, skb->data);
1875 			if (mpath) {
1876 				mpp_lookup = false;
1877 				next_hop = rcu_dereference(mpath->next_hop);
1878 				if (!next_hop ||
1879 				    !(mpath->flags & (MESH_PATH_ACTIVE |
1880 						      MESH_PATH_RESOLVING)))
1881 					mpp_lookup = true;
1882 			}
1883 
1884 			if (mpp_lookup)
1885 				mppath = mpp_path_lookup(sdata, skb->data);
1886 
1887 			if (mppath && mpath)
1888 				mesh_path_del(mpath->sdata, mpath->dst);
1889 		}
1890 
1891 		/*
1892 		 * Use address extension if it is a packet from
1893 		 * another interface or if we know the destination
1894 		 * is being proxied by a portal (i.e. portal address
1895 		 * differs from proxied address)
1896 		 */
1897 		if (ether_addr_equal(sdata->vif.addr, skb->data + ETH_ALEN) &&
1898 		    !(mppath && !ether_addr_equal(mppath->mpp, skb->data))) {
1899 			hdrlen = ieee80211_fill_mesh_addresses(&hdr, &fc,
1900 					skb->data, skb->data + ETH_ALEN);
1901 			meshhdrlen = ieee80211_new_mesh_header(sdata, &mesh_hdr,
1902 							       NULL, NULL);
1903 		} else {
1904 			/* DS -> MBSS (802.11-2012 13.11.3.3).
1905 			 * For unicast with unknown forwarding information,
1906 			 * destination might be in the MBSS or if that fails
1907 			 * forwarded to another mesh gate. In either case
1908 			 * resolution will be handled in ieee80211_xmit(), so
1909 			 * leave the original DA. This also works for mcast */
1910 			const u8 *mesh_da = skb->data;
1911 
1912 			if (mppath)
1913 				mesh_da = mppath->mpp;
1914 			else if (mpath)
1915 				mesh_da = mpath->dst;
1916 
1917 			hdrlen = ieee80211_fill_mesh_addresses(&hdr, &fc,
1918 					mesh_da, sdata->vif.addr);
1919 			if (is_multicast_ether_addr(mesh_da))
1920 				/* DA TA mSA AE:SA */
1921 				meshhdrlen = ieee80211_new_mesh_header(
1922 						sdata, &mesh_hdr,
1923 						skb->data + ETH_ALEN, NULL);
1924 			else
1925 				/* RA TA mDA mSA AE:DA SA */
1926 				meshhdrlen = ieee80211_new_mesh_header(
1927 						sdata, &mesh_hdr, skb->data,
1928 						skb->data + ETH_ALEN);
1929 
1930 		}
1931 		chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);
1932 		if (!chanctx_conf)
1933 			goto fail_rcu;
1934 		band = chanctx_conf->def.chan->band;
1935 		break;
1936 #endif
1937 	case NL80211_IFTYPE_STATION:
1938 		if (sdata->wdev.wiphy->flags & WIPHY_FLAG_SUPPORTS_TDLS) {
1939 			bool tdls_peer = false;
1940 
1941 			sta = sta_info_get(sdata, skb->data);
1942 			if (sta) {
1943 				authorized = test_sta_flag(sta,
1944 							WLAN_STA_AUTHORIZED);
1945 				wme_sta = test_sta_flag(sta, WLAN_STA_WME);
1946 				tdls_peer = test_sta_flag(sta,
1947 							 WLAN_STA_TDLS_PEER);
1948 				tdls_auth = test_sta_flag(sta,
1949 						WLAN_STA_TDLS_PEER_AUTH);
1950 			}
1951 
1952 			/*
1953 			 * If the TDLS link is enabled, send everything
1954 			 * directly. Otherwise, allow TDLS setup frames
1955 			 * to be transmitted indirectly.
1956 			 */
1957 			tdls_direct = tdls_peer && (tdls_auth ||
1958 				 !(ethertype == ETH_P_TDLS && skb->len > 14 &&
1959 				   skb->data[14] == WLAN_TDLS_SNAP_RFTYPE));
1960 		}
1961 
1962 		if (tdls_direct) {
1963 			/* link during setup - throw out frames to peer */
1964 			if (!tdls_auth)
1965 				goto fail_rcu;
1966 
1967 			/* DA SA BSSID */
1968 			memcpy(hdr.addr1, skb->data, ETH_ALEN);
1969 			memcpy(hdr.addr2, skb->data + ETH_ALEN, ETH_ALEN);
1970 			memcpy(hdr.addr3, sdata->u.mgd.bssid, ETH_ALEN);
1971 			hdrlen = 24;
1972 		}  else if (sdata->u.mgd.use_4addr &&
1973 			    cpu_to_be16(ethertype) != sdata->control_port_protocol) {
1974 			fc |= cpu_to_le16(IEEE80211_FCTL_FROMDS |
1975 					  IEEE80211_FCTL_TODS);
1976 			/* RA TA DA SA */
1977 			memcpy(hdr.addr1, sdata->u.mgd.bssid, ETH_ALEN);
1978 			memcpy(hdr.addr2, sdata->vif.addr, ETH_ALEN);
1979 			memcpy(hdr.addr3, skb->data, ETH_ALEN);
1980 			memcpy(hdr.addr4, skb->data + ETH_ALEN, ETH_ALEN);
1981 			hdrlen = 30;
1982 		} else {
1983 			fc |= cpu_to_le16(IEEE80211_FCTL_TODS);
1984 			/* BSSID SA DA */
1985 			memcpy(hdr.addr1, sdata->u.mgd.bssid, ETH_ALEN);
1986 			memcpy(hdr.addr2, skb->data + ETH_ALEN, ETH_ALEN);
1987 			memcpy(hdr.addr3, skb->data, ETH_ALEN);
1988 			hdrlen = 24;
1989 		}
1990 		chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);
1991 		if (!chanctx_conf)
1992 			goto fail_rcu;
1993 		band = chanctx_conf->def.chan->band;
1994 		break;
1995 	case NL80211_IFTYPE_ADHOC:
1996 		/* DA SA BSSID */
1997 		memcpy(hdr.addr1, skb->data, ETH_ALEN);
1998 		memcpy(hdr.addr2, skb->data + ETH_ALEN, ETH_ALEN);
1999 		memcpy(hdr.addr3, sdata->u.ibss.bssid, ETH_ALEN);
2000 		hdrlen = 24;
2001 		chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);
2002 		if (!chanctx_conf)
2003 			goto fail_rcu;
2004 		band = chanctx_conf->def.chan->band;
2005 		break;
2006 	default:
2007 		goto fail_rcu;
2008 	}
2009 
2010 	/*
2011 	 * There's no need to try to look up the destination
2012 	 * if it is a multicast address (which can only happen
2013 	 * in AP mode)
2014 	 */
2015 	multicast = is_multicast_ether_addr(hdr.addr1);
2016 	if (!multicast) {
2017 		sta = sta_info_get(sdata, hdr.addr1);
2018 		if (sta) {
2019 			authorized = test_sta_flag(sta, WLAN_STA_AUTHORIZED);
2020 			wme_sta = test_sta_flag(sta, WLAN_STA_WME);
2021 		}
2022 	}
2023 
2024 	/* For mesh, the use of the QoS header is mandatory */
2025 	if (ieee80211_vif_is_mesh(&sdata->vif))
2026 		wme_sta = true;
2027 
2028 	/* receiver and we are QoS enabled, use a QoS type frame */
2029 	if (wme_sta && local->hw.queues >= IEEE80211_NUM_ACS) {
2030 		fc |= cpu_to_le16(IEEE80211_STYPE_QOS_DATA);
2031 		hdrlen += 2;
2032 	}
2033 
2034 	/*
2035 	 * Drop unicast frames to unauthorised stations unless they are
2036 	 * EAPOL frames from the local station.
2037 	 */
2038 	if (unlikely(!ieee80211_vif_is_mesh(&sdata->vif) &&
2039 		     !multicast && !authorized &&
2040 		     (cpu_to_be16(ethertype) != sdata->control_port_protocol ||
2041 		      !ether_addr_equal(sdata->vif.addr, skb->data + ETH_ALEN)))) {
2042 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG
2043 		net_info_ratelimited("%s: dropped frame to %pM (unauthorized port)\n",
2044 				    dev->name, hdr.addr1);
2045 #endif
2046 
2047 		I802_DEBUG_INC(local->tx_handlers_drop_unauth_port);
2048 
2049 		goto fail_rcu;
2050 	}
2051 
2052 	if (unlikely(!multicast && skb->sk &&
2053 		     skb_shinfo(skb)->tx_flags & SKBTX_WIFI_STATUS)) {
2054 		struct sk_buff *orig_skb = skb;
2055 
2056 		skb = skb_clone(skb, GFP_ATOMIC);
2057 		if (skb) {
2058 			unsigned long flags;
2059 			int id;
2060 
2061 			spin_lock_irqsave(&local->ack_status_lock, flags);
2062 			id = idr_alloc(&local->ack_status_frames, orig_skb,
2063 				       1, 0x10000, GFP_ATOMIC);
2064 			spin_unlock_irqrestore(&local->ack_status_lock, flags);
2065 
2066 			if (id >= 0) {
2067 				info_id = id;
2068 				info_flags |= IEEE80211_TX_CTL_REQ_TX_STATUS;
2069 			} else if (skb_shared(skb)) {
2070 				kfree_skb(orig_skb);
2071 			} else {
2072 				kfree_skb(skb);
2073 				skb = orig_skb;
2074 			}
2075 		} else {
2076 			/* couldn't clone -- lose tx status ... */
2077 			skb = orig_skb;
2078 		}
2079 	}
2080 
2081 	/*
2082 	 * If the skb is shared we need to obtain our own copy.
2083 	 */
2084 	if (skb_shared(skb)) {
2085 		struct sk_buff *tmp_skb = skb;
2086 
2087 		/* can't happen -- skb is a clone if info_id != 0 */
2088 		WARN_ON(info_id);
2089 
2090 		skb = skb_clone(skb, GFP_ATOMIC);
2091 		kfree_skb(tmp_skb);
2092 
2093 		if (!skb)
2094 			goto fail_rcu;
2095 	}
2096 
2097 	hdr.frame_control = fc;
2098 	hdr.duration_id = 0;
2099 	hdr.seq_ctrl = 0;
2100 
2101 	skip_header_bytes = ETH_HLEN;
2102 	if (ethertype == ETH_P_AARP || ethertype == ETH_P_IPX) {
2103 		encaps_data = bridge_tunnel_header;
2104 		encaps_len = sizeof(bridge_tunnel_header);
2105 		skip_header_bytes -= 2;
2106 	} else if (ethertype >= ETH_P_802_3_MIN) {
2107 		encaps_data = rfc1042_header;
2108 		encaps_len = sizeof(rfc1042_header);
2109 		skip_header_bytes -= 2;
2110 	} else {
2111 		encaps_data = NULL;
2112 		encaps_len = 0;
2113 	}
2114 
2115 	nh_pos = skb_network_header(skb) - skb->data;
2116 	h_pos = skb_transport_header(skb) - skb->data;
2117 
2118 	skb_pull(skb, skip_header_bytes);
2119 	nh_pos -= skip_header_bytes;
2120 	h_pos -= skip_header_bytes;
2121 
2122 	head_need = hdrlen + encaps_len + meshhdrlen - skb_headroom(skb);
2123 
2124 	/*
2125 	 * So we need to modify the skb header and hence need a copy of
2126 	 * that. The head_need variable above doesn't, so far, include
2127 	 * the needed header space that we don't need right away. If we
2128 	 * can, then we don't reallocate right now but only after the
2129 	 * frame arrives at the master device (if it does...)
2130 	 *
2131 	 * If we cannot, however, then we will reallocate to include all
2132 	 * the ever needed space. Also, if we need to reallocate it anyway,
2133 	 * make it big enough for everything we may ever need.
2134 	 */
2135 
2136 	if (head_need > 0 || skb_cloned(skb)) {
2137 		head_need += sdata->encrypt_headroom;
2138 		head_need += local->tx_headroom;
2139 		head_need = max_t(int, 0, head_need);
2140 		if (ieee80211_skb_resize(sdata, skb, head_need, true)) {
2141 			ieee80211_free_txskb(&local->hw, skb);
2142 			skb = NULL;
2143 			goto fail_rcu;
2144 		}
2145 	}
2146 
2147 	if (encaps_data) {
2148 		memcpy(skb_push(skb, encaps_len), encaps_data, encaps_len);
2149 		nh_pos += encaps_len;
2150 		h_pos += encaps_len;
2151 	}
2152 
2153 #ifdef CONFIG_MAC80211_MESH
2154 	if (meshhdrlen > 0) {
2155 		memcpy(skb_push(skb, meshhdrlen), &mesh_hdr, meshhdrlen);
2156 		nh_pos += meshhdrlen;
2157 		h_pos += meshhdrlen;
2158 	}
2159 #endif
2160 
2161 	if (ieee80211_is_data_qos(fc)) {
2162 		__le16 *qos_control;
2163 
2164 		qos_control = (__le16*) skb_push(skb, 2);
2165 		memcpy(skb_push(skb, hdrlen - 2), &hdr, hdrlen - 2);
2166 		/*
2167 		 * Maybe we could actually set some fields here, for now just
2168 		 * initialise to zero to indicate no special operation.
2169 		 */
2170 		*qos_control = 0;
2171 	} else
2172 		memcpy(skb_push(skb, hdrlen), &hdr, hdrlen);
2173 
2174 	nh_pos += hdrlen;
2175 	h_pos += hdrlen;
2176 
2177 	dev->stats.tx_packets++;
2178 	dev->stats.tx_bytes += skb->len;
2179 
2180 	/* Update skb pointers to various headers since this modified frame
2181 	 * is going to go through Linux networking code that may potentially
2182 	 * need things like pointer to IP header. */
2183 	skb_set_mac_header(skb, 0);
2184 	skb_set_network_header(skb, nh_pos);
2185 	skb_set_transport_header(skb, h_pos);
2186 
2187 	info = IEEE80211_SKB_CB(skb);
2188 	memset(info, 0, sizeof(*info));
2189 
2190 	dev->trans_start = jiffies;
2191 
2192 	info->flags = info_flags;
2193 	info->ack_frame_id = info_id;
2194 
2195 	ieee80211_xmit(sdata, skb, band);
2196 	rcu_read_unlock();
2197 
2198 	return NETDEV_TX_OK;
2199 
2200  fail_rcu:
2201 	rcu_read_unlock();
2202  fail:
2203 	dev_kfree_skb(skb);
2204 	return NETDEV_TX_OK;
2205 }
2206 
2207 
2208 /*
2209  * ieee80211_clear_tx_pending may not be called in a context where
2210  * it is possible that it packets could come in again.
2211  */
2212 void ieee80211_clear_tx_pending(struct ieee80211_local *local)
2213 {
2214 	struct sk_buff *skb;
2215 	int i;
2216 
2217 	for (i = 0; i < local->hw.queues; i++) {
2218 		while ((skb = skb_dequeue(&local->pending[i])) != NULL)
2219 			ieee80211_free_txskb(&local->hw, skb);
2220 	}
2221 }
2222 
2223 /*
2224  * Returns false if the frame couldn't be transmitted but was queued instead,
2225  * which in this case means re-queued -- take as an indication to stop sending
2226  * more pending frames.
2227  */
2228 static bool ieee80211_tx_pending_skb(struct ieee80211_local *local,
2229 				     struct sk_buff *skb)
2230 {
2231 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
2232 	struct ieee80211_sub_if_data *sdata;
2233 	struct sta_info *sta;
2234 	struct ieee80211_hdr *hdr;
2235 	bool result;
2236 	struct ieee80211_chanctx_conf *chanctx_conf;
2237 
2238 	sdata = vif_to_sdata(info->control.vif);
2239 
2240 	if (info->flags & IEEE80211_TX_INTFL_NEED_TXPROCESSING) {
2241 		chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);
2242 		if (unlikely(!chanctx_conf)) {
2243 			dev_kfree_skb(skb);
2244 			return true;
2245 		}
2246 		result = ieee80211_tx(sdata, skb, true,
2247 				      chanctx_conf->def.chan->band);
2248 	} else {
2249 		struct sk_buff_head skbs;
2250 
2251 		__skb_queue_head_init(&skbs);
2252 		__skb_queue_tail(&skbs, skb);
2253 
2254 		hdr = (struct ieee80211_hdr *)skb->data;
2255 		sta = sta_info_get(sdata, hdr->addr1);
2256 
2257 		result = __ieee80211_tx(local, &skbs, skb->len, sta, true);
2258 	}
2259 
2260 	return result;
2261 }
2262 
2263 /*
2264  * Transmit all pending packets. Called from tasklet.
2265  */
2266 void ieee80211_tx_pending(unsigned long data)
2267 {
2268 	struct ieee80211_local *local = (struct ieee80211_local *)data;
2269 	unsigned long flags;
2270 	int i;
2271 	bool txok;
2272 
2273 	rcu_read_lock();
2274 
2275 	spin_lock_irqsave(&local->queue_stop_reason_lock, flags);
2276 	for (i = 0; i < local->hw.queues; i++) {
2277 		/*
2278 		 * If queue is stopped by something other than due to pending
2279 		 * frames, or we have no pending frames, proceed to next queue.
2280 		 */
2281 		if (local->queue_stop_reasons[i] ||
2282 		    skb_queue_empty(&local->pending[i]))
2283 			continue;
2284 
2285 		while (!skb_queue_empty(&local->pending[i])) {
2286 			struct sk_buff *skb = __skb_dequeue(&local->pending[i]);
2287 			struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
2288 
2289 			if (WARN_ON(!info->control.vif)) {
2290 				ieee80211_free_txskb(&local->hw, skb);
2291 				continue;
2292 			}
2293 
2294 			spin_unlock_irqrestore(&local->queue_stop_reason_lock,
2295 						flags);
2296 
2297 			txok = ieee80211_tx_pending_skb(local, skb);
2298 			spin_lock_irqsave(&local->queue_stop_reason_lock,
2299 					  flags);
2300 			if (!txok)
2301 				break;
2302 		}
2303 
2304 		if (skb_queue_empty(&local->pending[i]))
2305 			ieee80211_propagate_queue_wake(local, i);
2306 	}
2307 	spin_unlock_irqrestore(&local->queue_stop_reason_lock, flags);
2308 
2309 	rcu_read_unlock();
2310 }
2311 
2312 /* functions for drivers to get certain frames */
2313 
2314 static void __ieee80211_beacon_add_tim(struct ieee80211_sub_if_data *sdata,
2315 				       struct ps_data *ps, struct sk_buff *skb)
2316 {
2317 	u8 *pos, *tim;
2318 	int aid0 = 0;
2319 	int i, have_bits = 0, n1, n2;
2320 
2321 	/* Generate bitmap for TIM only if there are any STAs in power save
2322 	 * mode. */
2323 	if (atomic_read(&ps->num_sta_ps) > 0)
2324 		/* in the hope that this is faster than
2325 		 * checking byte-for-byte */
2326 		have_bits = !bitmap_empty((unsigned long*)ps->tim,
2327 					  IEEE80211_MAX_AID+1);
2328 
2329 	if (ps->dtim_count == 0)
2330 		ps->dtim_count = sdata->vif.bss_conf.dtim_period - 1;
2331 	else
2332 		ps->dtim_count--;
2333 
2334 	tim = pos = (u8 *) skb_put(skb, 6);
2335 	*pos++ = WLAN_EID_TIM;
2336 	*pos++ = 4;
2337 	*pos++ = ps->dtim_count;
2338 	*pos++ = sdata->vif.bss_conf.dtim_period;
2339 
2340 	if (ps->dtim_count == 0 && !skb_queue_empty(&ps->bc_buf))
2341 		aid0 = 1;
2342 
2343 	ps->dtim_bc_mc = aid0 == 1;
2344 
2345 	if (have_bits) {
2346 		/* Find largest even number N1 so that bits numbered 1 through
2347 		 * (N1 x 8) - 1 in the bitmap are 0 and number N2 so that bits
2348 		 * (N2 + 1) x 8 through 2007 are 0. */
2349 		n1 = 0;
2350 		for (i = 0; i < IEEE80211_MAX_TIM_LEN; i++) {
2351 			if (ps->tim[i]) {
2352 				n1 = i & 0xfe;
2353 				break;
2354 			}
2355 		}
2356 		n2 = n1;
2357 		for (i = IEEE80211_MAX_TIM_LEN - 1; i >= n1; i--) {
2358 			if (ps->tim[i]) {
2359 				n2 = i;
2360 				break;
2361 			}
2362 		}
2363 
2364 		/* Bitmap control */
2365 		*pos++ = n1 | aid0;
2366 		/* Part Virt Bitmap */
2367 		skb_put(skb, n2 - n1);
2368 		memcpy(pos, ps->tim + n1, n2 - n1 + 1);
2369 
2370 		tim[1] = n2 - n1 + 4;
2371 	} else {
2372 		*pos++ = aid0; /* Bitmap control */
2373 		*pos++ = 0; /* Part Virt Bitmap */
2374 	}
2375 }
2376 
2377 static int ieee80211_beacon_add_tim(struct ieee80211_sub_if_data *sdata,
2378 				    struct ps_data *ps, struct sk_buff *skb)
2379 {
2380 	struct ieee80211_local *local = sdata->local;
2381 
2382 	/*
2383 	 * Not very nice, but we want to allow the driver to call
2384 	 * ieee80211_beacon_get() as a response to the set_tim()
2385 	 * callback. That, however, is already invoked under the
2386 	 * sta_lock to guarantee consistent and race-free update
2387 	 * of the tim bitmap in mac80211 and the driver.
2388 	 */
2389 	if (local->tim_in_locked_section) {
2390 		__ieee80211_beacon_add_tim(sdata, ps, skb);
2391 	} else {
2392 		spin_lock_bh(&local->tim_lock);
2393 		__ieee80211_beacon_add_tim(sdata, ps, skb);
2394 		spin_unlock_bh(&local->tim_lock);
2395 	}
2396 
2397 	return 0;
2398 }
2399 
2400 void ieee80211_csa_finish(struct ieee80211_vif *vif)
2401 {
2402 	struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
2403 
2404 	ieee80211_queue_work(&sdata->local->hw,
2405 			     &sdata->csa_finalize_work);
2406 }
2407 EXPORT_SYMBOL(ieee80211_csa_finish);
2408 
2409 static void ieee80211_update_csa(struct ieee80211_sub_if_data *sdata,
2410 				 struct beacon_data *beacon)
2411 {
2412 	struct probe_resp *resp;
2413 	int counter_offset_beacon = sdata->csa_counter_offset_beacon;
2414 	int counter_offset_presp = sdata->csa_counter_offset_presp;
2415 	u8 *beacon_data;
2416 	size_t beacon_data_len;
2417 
2418 	switch (sdata->vif.type) {
2419 	case NL80211_IFTYPE_AP:
2420 		beacon_data = beacon->tail;
2421 		beacon_data_len = beacon->tail_len;
2422 		break;
2423 	case NL80211_IFTYPE_ADHOC:
2424 		beacon_data = beacon->head;
2425 		beacon_data_len = beacon->head_len;
2426 		break;
2427 	case NL80211_IFTYPE_MESH_POINT:
2428 		beacon_data = beacon->head;
2429 		beacon_data_len = beacon->head_len;
2430 		break;
2431 	default:
2432 		return;
2433 	}
2434 	if (WARN_ON(counter_offset_beacon >= beacon_data_len))
2435 		return;
2436 
2437 	/* warn if the driver did not check for/react to csa completeness */
2438 	if (WARN_ON(beacon_data[counter_offset_beacon] == 0))
2439 		return;
2440 
2441 	beacon_data[counter_offset_beacon]--;
2442 
2443 	if (sdata->vif.type == NL80211_IFTYPE_AP && counter_offset_presp) {
2444 		rcu_read_lock();
2445 		resp = rcu_dereference(sdata->u.ap.probe_resp);
2446 
2447 		/* if nl80211 accepted the offset, this should not happen. */
2448 		if (WARN_ON(!resp)) {
2449 			rcu_read_unlock();
2450 			return;
2451 		}
2452 		resp->data[counter_offset_presp]--;
2453 		rcu_read_unlock();
2454 	}
2455 }
2456 
2457 bool ieee80211_csa_is_complete(struct ieee80211_vif *vif)
2458 {
2459 	struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
2460 	struct beacon_data *beacon = NULL;
2461 	u8 *beacon_data;
2462 	size_t beacon_data_len;
2463 	int counter_beacon = sdata->csa_counter_offset_beacon;
2464 	int ret = false;
2465 
2466 	if (!ieee80211_sdata_running(sdata))
2467 		return false;
2468 
2469 	rcu_read_lock();
2470 	if (vif->type == NL80211_IFTYPE_AP) {
2471 		struct ieee80211_if_ap *ap = &sdata->u.ap;
2472 
2473 		beacon = rcu_dereference(ap->beacon);
2474 		if (WARN_ON(!beacon || !beacon->tail))
2475 			goto out;
2476 		beacon_data = beacon->tail;
2477 		beacon_data_len = beacon->tail_len;
2478 	} else if (vif->type == NL80211_IFTYPE_ADHOC) {
2479 		struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
2480 
2481 		beacon = rcu_dereference(ifibss->presp);
2482 		if (!beacon)
2483 			goto out;
2484 
2485 		beacon_data = beacon->head;
2486 		beacon_data_len = beacon->head_len;
2487 	} else if (vif->type == NL80211_IFTYPE_MESH_POINT) {
2488 		struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
2489 
2490 		beacon = rcu_dereference(ifmsh->beacon);
2491 		if (!beacon)
2492 			goto out;
2493 
2494 		beacon_data = beacon->head;
2495 		beacon_data_len = beacon->head_len;
2496 	} else {
2497 		WARN_ON(1);
2498 		goto out;
2499 	}
2500 
2501 	if (WARN_ON(counter_beacon > beacon_data_len))
2502 		goto out;
2503 
2504 	if (beacon_data[counter_beacon] == 0)
2505 		ret = true;
2506  out:
2507 	rcu_read_unlock();
2508 
2509 	return ret;
2510 }
2511 EXPORT_SYMBOL(ieee80211_csa_is_complete);
2512 
2513 struct sk_buff *ieee80211_beacon_get_tim(struct ieee80211_hw *hw,
2514 					 struct ieee80211_vif *vif,
2515 					 u16 *tim_offset, u16 *tim_length)
2516 {
2517 	struct ieee80211_local *local = hw_to_local(hw);
2518 	struct sk_buff *skb = NULL;
2519 	struct ieee80211_tx_info *info;
2520 	struct ieee80211_sub_if_data *sdata = NULL;
2521 	enum ieee80211_band band;
2522 	struct ieee80211_tx_rate_control txrc;
2523 	struct ieee80211_chanctx_conf *chanctx_conf;
2524 
2525 	rcu_read_lock();
2526 
2527 	sdata = vif_to_sdata(vif);
2528 	chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);
2529 
2530 	if (!ieee80211_sdata_running(sdata) || !chanctx_conf)
2531 		goto out;
2532 
2533 	if (tim_offset)
2534 		*tim_offset = 0;
2535 	if (tim_length)
2536 		*tim_length = 0;
2537 
2538 	if (sdata->vif.type == NL80211_IFTYPE_AP) {
2539 		struct ieee80211_if_ap *ap = &sdata->u.ap;
2540 		struct beacon_data *beacon = rcu_dereference(ap->beacon);
2541 
2542 		if (beacon) {
2543 			if (sdata->vif.csa_active)
2544 				ieee80211_update_csa(sdata, beacon);
2545 
2546 			/*
2547 			 * headroom, head length,
2548 			 * tail length and maximum TIM length
2549 			 */
2550 			skb = dev_alloc_skb(local->tx_headroom +
2551 					    beacon->head_len +
2552 					    beacon->tail_len + 256);
2553 			if (!skb)
2554 				goto out;
2555 
2556 			skb_reserve(skb, local->tx_headroom);
2557 			memcpy(skb_put(skb, beacon->head_len), beacon->head,
2558 			       beacon->head_len);
2559 
2560 			ieee80211_beacon_add_tim(sdata, &ap->ps, skb);
2561 
2562 			if (tim_offset)
2563 				*tim_offset = beacon->head_len;
2564 			if (tim_length)
2565 				*tim_length = skb->len - beacon->head_len;
2566 
2567 			if (beacon->tail)
2568 				memcpy(skb_put(skb, beacon->tail_len),
2569 				       beacon->tail, beacon->tail_len);
2570 		} else
2571 			goto out;
2572 	} else if (sdata->vif.type == NL80211_IFTYPE_ADHOC) {
2573 		struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
2574 		struct ieee80211_hdr *hdr;
2575 		struct beacon_data *presp = rcu_dereference(ifibss->presp);
2576 
2577 		if (!presp)
2578 			goto out;
2579 
2580 		if (sdata->vif.csa_active)
2581 			ieee80211_update_csa(sdata, presp);
2582 
2583 
2584 		skb = dev_alloc_skb(local->tx_headroom + presp->head_len);
2585 		if (!skb)
2586 			goto out;
2587 		skb_reserve(skb, local->tx_headroom);
2588 		memcpy(skb_put(skb, presp->head_len), presp->head,
2589 		       presp->head_len);
2590 
2591 		hdr = (struct ieee80211_hdr *) skb->data;
2592 		hdr->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
2593 						 IEEE80211_STYPE_BEACON);
2594 	} else if (ieee80211_vif_is_mesh(&sdata->vif)) {
2595 		struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
2596 		struct beacon_data *bcn = rcu_dereference(ifmsh->beacon);
2597 
2598 		if (!bcn)
2599 			goto out;
2600 
2601 		if (sdata->vif.csa_active)
2602 			ieee80211_update_csa(sdata, bcn);
2603 
2604 		if (ifmsh->sync_ops)
2605 			ifmsh->sync_ops->adjust_tbtt(
2606 						sdata);
2607 
2608 		skb = dev_alloc_skb(local->tx_headroom +
2609 				    bcn->head_len +
2610 				    256 + /* TIM IE */
2611 				    bcn->tail_len);
2612 		if (!skb)
2613 			goto out;
2614 		skb_reserve(skb, local->tx_headroom);
2615 		memcpy(skb_put(skb, bcn->head_len), bcn->head, bcn->head_len);
2616 		ieee80211_beacon_add_tim(sdata, &ifmsh->ps, skb);
2617 		memcpy(skb_put(skb, bcn->tail_len), bcn->tail, bcn->tail_len);
2618 	} else {
2619 		WARN_ON(1);
2620 		goto out;
2621 	}
2622 
2623 	band = chanctx_conf->def.chan->band;
2624 
2625 	info = IEEE80211_SKB_CB(skb);
2626 
2627 	info->flags |= IEEE80211_TX_INTFL_DONT_ENCRYPT;
2628 	info->flags |= IEEE80211_TX_CTL_NO_ACK;
2629 	info->band = band;
2630 
2631 	memset(&txrc, 0, sizeof(txrc));
2632 	txrc.hw = hw;
2633 	txrc.sband = local->hw.wiphy->bands[band];
2634 	txrc.bss_conf = &sdata->vif.bss_conf;
2635 	txrc.skb = skb;
2636 	txrc.reported_rate.idx = -1;
2637 	txrc.rate_idx_mask = sdata->rc_rateidx_mask[band];
2638 	if (txrc.rate_idx_mask == (1 << txrc.sband->n_bitrates) - 1)
2639 		txrc.max_rate_idx = -1;
2640 	else
2641 		txrc.max_rate_idx = fls(txrc.rate_idx_mask) - 1;
2642 	txrc.bss = true;
2643 	rate_control_get_rate(sdata, NULL, &txrc);
2644 
2645 	info->control.vif = vif;
2646 
2647 	info->flags |= IEEE80211_TX_CTL_CLEAR_PS_FILT |
2648 			IEEE80211_TX_CTL_ASSIGN_SEQ |
2649 			IEEE80211_TX_CTL_FIRST_FRAGMENT;
2650  out:
2651 	rcu_read_unlock();
2652 	return skb;
2653 }
2654 EXPORT_SYMBOL(ieee80211_beacon_get_tim);
2655 
2656 struct sk_buff *ieee80211_proberesp_get(struct ieee80211_hw *hw,
2657 					struct ieee80211_vif *vif)
2658 {
2659 	struct ieee80211_if_ap *ap = NULL;
2660 	struct sk_buff *skb = NULL;
2661 	struct probe_resp *presp = NULL;
2662 	struct ieee80211_hdr *hdr;
2663 	struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
2664 
2665 	if (sdata->vif.type != NL80211_IFTYPE_AP)
2666 		return NULL;
2667 
2668 	rcu_read_lock();
2669 
2670 	ap = &sdata->u.ap;
2671 	presp = rcu_dereference(ap->probe_resp);
2672 	if (!presp)
2673 		goto out;
2674 
2675 	skb = dev_alloc_skb(presp->len);
2676 	if (!skb)
2677 		goto out;
2678 
2679 	memcpy(skb_put(skb, presp->len), presp->data, presp->len);
2680 
2681 	hdr = (struct ieee80211_hdr *) skb->data;
2682 	memset(hdr->addr1, 0, sizeof(hdr->addr1));
2683 
2684 out:
2685 	rcu_read_unlock();
2686 	return skb;
2687 }
2688 EXPORT_SYMBOL(ieee80211_proberesp_get);
2689 
2690 struct sk_buff *ieee80211_pspoll_get(struct ieee80211_hw *hw,
2691 				     struct ieee80211_vif *vif)
2692 {
2693 	struct ieee80211_sub_if_data *sdata;
2694 	struct ieee80211_if_managed *ifmgd;
2695 	struct ieee80211_pspoll *pspoll;
2696 	struct ieee80211_local *local;
2697 	struct sk_buff *skb;
2698 
2699 	if (WARN_ON(vif->type != NL80211_IFTYPE_STATION))
2700 		return NULL;
2701 
2702 	sdata = vif_to_sdata(vif);
2703 	ifmgd = &sdata->u.mgd;
2704 	local = sdata->local;
2705 
2706 	skb = dev_alloc_skb(local->hw.extra_tx_headroom + sizeof(*pspoll));
2707 	if (!skb)
2708 		return NULL;
2709 
2710 	skb_reserve(skb, local->hw.extra_tx_headroom);
2711 
2712 	pspoll = (struct ieee80211_pspoll *) skb_put(skb, sizeof(*pspoll));
2713 	memset(pspoll, 0, sizeof(*pspoll));
2714 	pspoll->frame_control = cpu_to_le16(IEEE80211_FTYPE_CTL |
2715 					    IEEE80211_STYPE_PSPOLL);
2716 	pspoll->aid = cpu_to_le16(ifmgd->aid);
2717 
2718 	/* aid in PS-Poll has its two MSBs each set to 1 */
2719 	pspoll->aid |= cpu_to_le16(1 << 15 | 1 << 14);
2720 
2721 	memcpy(pspoll->bssid, ifmgd->bssid, ETH_ALEN);
2722 	memcpy(pspoll->ta, vif->addr, ETH_ALEN);
2723 
2724 	return skb;
2725 }
2726 EXPORT_SYMBOL(ieee80211_pspoll_get);
2727 
2728 struct sk_buff *ieee80211_nullfunc_get(struct ieee80211_hw *hw,
2729 				       struct ieee80211_vif *vif)
2730 {
2731 	struct ieee80211_hdr_3addr *nullfunc;
2732 	struct ieee80211_sub_if_data *sdata;
2733 	struct ieee80211_if_managed *ifmgd;
2734 	struct ieee80211_local *local;
2735 	struct sk_buff *skb;
2736 
2737 	if (WARN_ON(vif->type != NL80211_IFTYPE_STATION))
2738 		return NULL;
2739 
2740 	sdata = vif_to_sdata(vif);
2741 	ifmgd = &sdata->u.mgd;
2742 	local = sdata->local;
2743 
2744 	skb = dev_alloc_skb(local->hw.extra_tx_headroom + sizeof(*nullfunc));
2745 	if (!skb)
2746 		return NULL;
2747 
2748 	skb_reserve(skb, local->hw.extra_tx_headroom);
2749 
2750 	nullfunc = (struct ieee80211_hdr_3addr *) skb_put(skb,
2751 							  sizeof(*nullfunc));
2752 	memset(nullfunc, 0, sizeof(*nullfunc));
2753 	nullfunc->frame_control = cpu_to_le16(IEEE80211_FTYPE_DATA |
2754 					      IEEE80211_STYPE_NULLFUNC |
2755 					      IEEE80211_FCTL_TODS);
2756 	memcpy(nullfunc->addr1, ifmgd->bssid, ETH_ALEN);
2757 	memcpy(nullfunc->addr2, vif->addr, ETH_ALEN);
2758 	memcpy(nullfunc->addr3, ifmgd->bssid, ETH_ALEN);
2759 
2760 	return skb;
2761 }
2762 EXPORT_SYMBOL(ieee80211_nullfunc_get);
2763 
2764 struct sk_buff *ieee80211_probereq_get(struct ieee80211_hw *hw,
2765 				       struct ieee80211_vif *vif,
2766 				       const u8 *ssid, size_t ssid_len,
2767 				       size_t tailroom)
2768 {
2769 	struct ieee80211_sub_if_data *sdata;
2770 	struct ieee80211_local *local;
2771 	struct ieee80211_hdr_3addr *hdr;
2772 	struct sk_buff *skb;
2773 	size_t ie_ssid_len;
2774 	u8 *pos;
2775 
2776 	sdata = vif_to_sdata(vif);
2777 	local = sdata->local;
2778 	ie_ssid_len = 2 + ssid_len;
2779 
2780 	skb = dev_alloc_skb(local->hw.extra_tx_headroom + sizeof(*hdr) +
2781 			    ie_ssid_len + tailroom);
2782 	if (!skb)
2783 		return NULL;
2784 
2785 	skb_reserve(skb, local->hw.extra_tx_headroom);
2786 
2787 	hdr = (struct ieee80211_hdr_3addr *) skb_put(skb, sizeof(*hdr));
2788 	memset(hdr, 0, sizeof(*hdr));
2789 	hdr->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
2790 					 IEEE80211_STYPE_PROBE_REQ);
2791 	eth_broadcast_addr(hdr->addr1);
2792 	memcpy(hdr->addr2, vif->addr, ETH_ALEN);
2793 	eth_broadcast_addr(hdr->addr3);
2794 
2795 	pos = skb_put(skb, ie_ssid_len);
2796 	*pos++ = WLAN_EID_SSID;
2797 	*pos++ = ssid_len;
2798 	if (ssid_len)
2799 		memcpy(pos, ssid, ssid_len);
2800 	pos += ssid_len;
2801 
2802 	return skb;
2803 }
2804 EXPORT_SYMBOL(ieee80211_probereq_get);
2805 
2806 void ieee80211_rts_get(struct ieee80211_hw *hw, struct ieee80211_vif *vif,
2807 		       const void *frame, size_t frame_len,
2808 		       const struct ieee80211_tx_info *frame_txctl,
2809 		       struct ieee80211_rts *rts)
2810 {
2811 	const struct ieee80211_hdr *hdr = frame;
2812 
2813 	rts->frame_control =
2814 	    cpu_to_le16(IEEE80211_FTYPE_CTL | IEEE80211_STYPE_RTS);
2815 	rts->duration = ieee80211_rts_duration(hw, vif, frame_len,
2816 					       frame_txctl);
2817 	memcpy(rts->ra, hdr->addr1, sizeof(rts->ra));
2818 	memcpy(rts->ta, hdr->addr2, sizeof(rts->ta));
2819 }
2820 EXPORT_SYMBOL(ieee80211_rts_get);
2821 
2822 void ieee80211_ctstoself_get(struct ieee80211_hw *hw, struct ieee80211_vif *vif,
2823 			     const void *frame, size_t frame_len,
2824 			     const struct ieee80211_tx_info *frame_txctl,
2825 			     struct ieee80211_cts *cts)
2826 {
2827 	const struct ieee80211_hdr *hdr = frame;
2828 
2829 	cts->frame_control =
2830 	    cpu_to_le16(IEEE80211_FTYPE_CTL | IEEE80211_STYPE_CTS);
2831 	cts->duration = ieee80211_ctstoself_duration(hw, vif,
2832 						     frame_len, frame_txctl);
2833 	memcpy(cts->ra, hdr->addr1, sizeof(cts->ra));
2834 }
2835 EXPORT_SYMBOL(ieee80211_ctstoself_get);
2836 
2837 struct sk_buff *
2838 ieee80211_get_buffered_bc(struct ieee80211_hw *hw,
2839 			  struct ieee80211_vif *vif)
2840 {
2841 	struct ieee80211_local *local = hw_to_local(hw);
2842 	struct sk_buff *skb = NULL;
2843 	struct ieee80211_tx_data tx;
2844 	struct ieee80211_sub_if_data *sdata;
2845 	struct ps_data *ps;
2846 	struct ieee80211_tx_info *info;
2847 	struct ieee80211_chanctx_conf *chanctx_conf;
2848 
2849 	sdata = vif_to_sdata(vif);
2850 
2851 	rcu_read_lock();
2852 	chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);
2853 
2854 	if (!chanctx_conf)
2855 		goto out;
2856 
2857 	if (sdata->vif.type == NL80211_IFTYPE_AP) {
2858 		struct beacon_data *beacon =
2859 				rcu_dereference(sdata->u.ap.beacon);
2860 
2861 		if (!beacon || !beacon->head)
2862 			goto out;
2863 
2864 		ps = &sdata->u.ap.ps;
2865 	} else if (ieee80211_vif_is_mesh(&sdata->vif)) {
2866 		ps = &sdata->u.mesh.ps;
2867 	} else {
2868 		goto out;
2869 	}
2870 
2871 	if (ps->dtim_count != 0 || !ps->dtim_bc_mc)
2872 		goto out; /* send buffered bc/mc only after DTIM beacon */
2873 
2874 	while (1) {
2875 		skb = skb_dequeue(&ps->bc_buf);
2876 		if (!skb)
2877 			goto out;
2878 		local->total_ps_buffered--;
2879 
2880 		if (!skb_queue_empty(&ps->bc_buf) && skb->len >= 2) {
2881 			struct ieee80211_hdr *hdr =
2882 				(struct ieee80211_hdr *) skb->data;
2883 			/* more buffered multicast/broadcast frames ==> set
2884 			 * MoreData flag in IEEE 802.11 header to inform PS
2885 			 * STAs */
2886 			hdr->frame_control |=
2887 				cpu_to_le16(IEEE80211_FCTL_MOREDATA);
2888 		}
2889 
2890 		if (sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
2891 			sdata = IEEE80211_DEV_TO_SUB_IF(skb->dev);
2892 		if (!ieee80211_tx_prepare(sdata, &tx, skb))
2893 			break;
2894 		dev_kfree_skb_any(skb);
2895 	}
2896 
2897 	info = IEEE80211_SKB_CB(skb);
2898 
2899 	tx.flags |= IEEE80211_TX_PS_BUFFERED;
2900 	info->band = chanctx_conf->def.chan->band;
2901 
2902 	if (invoke_tx_handlers(&tx))
2903 		skb = NULL;
2904  out:
2905 	rcu_read_unlock();
2906 
2907 	return skb;
2908 }
2909 EXPORT_SYMBOL(ieee80211_get_buffered_bc);
2910 
2911 void __ieee80211_tx_skb_tid_band(struct ieee80211_sub_if_data *sdata,
2912 				 struct sk_buff *skb, int tid,
2913 				 enum ieee80211_band band)
2914 {
2915 	int ac = ieee802_1d_to_ac[tid & 7];
2916 
2917 	skb_set_mac_header(skb, 0);
2918 	skb_set_network_header(skb, 0);
2919 	skb_set_transport_header(skb, 0);
2920 
2921 	skb_set_queue_mapping(skb, ac);
2922 	skb->priority = tid;
2923 
2924 	skb->dev = sdata->dev;
2925 
2926 	/*
2927 	 * The other path calling ieee80211_xmit is from the tasklet,
2928 	 * and while we can handle concurrent transmissions locking
2929 	 * requirements are that we do not come into tx with bhs on.
2930 	 */
2931 	local_bh_disable();
2932 	ieee80211_xmit(sdata, skb, band);
2933 	local_bh_enable();
2934 }
2935