xref: /linux/net/mac80211/tx.c (revision 02bafd96f3a5d8e610b19033ffec55b92459aaae)
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  * Copyright 2013-2014  Intel Mobile Communications GmbH
7  *
8  * This program is free software; you can redistribute it and/or modify
9  * it under the terms of the GNU General Public License version 2 as
10  * published by the Free Software Foundation.
11  *
12  *
13  * Transmit and frame generation functions.
14  */
15 
16 #include <linux/kernel.h>
17 #include <linux/slab.h>
18 #include <linux/skbuff.h>
19 #include <linux/etherdevice.h>
20 #include <linux/bitmap.h>
21 #include <linux/rcupdate.h>
22 #include <linux/export.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 <net/codel.h>
28 #include <net/codel_impl.h>
29 #include <asm/unaligned.h>
30 #include <net/fq_impl.h>
31 
32 #include "ieee80211_i.h"
33 #include "driver-ops.h"
34 #include "led.h"
35 #include "mesh.h"
36 #include "wep.h"
37 #include "wpa.h"
38 #include "wme.h"
39 #include "rate.h"
40 
41 /* misc utils */
42 
43 static inline void ieee80211_tx_stats(struct net_device *dev, u32 len)
44 {
45 	struct pcpu_sw_netstats *tstats = this_cpu_ptr(dev->tstats);
46 
47 	u64_stats_update_begin(&tstats->syncp);
48 	tstats->tx_packets++;
49 	tstats->tx_bytes += len;
50 	u64_stats_update_end(&tstats->syncp);
51 }
52 
53 static __le16 ieee80211_duration(struct ieee80211_tx_data *tx,
54 				 struct sk_buff *skb, int group_addr,
55 				 int next_frag_len)
56 {
57 	int rate, mrate, erp, dur, i, shift = 0;
58 	struct ieee80211_rate *txrate;
59 	struct ieee80211_local *local = tx->local;
60 	struct ieee80211_supported_band *sband;
61 	struct ieee80211_hdr *hdr;
62 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
63 	struct ieee80211_chanctx_conf *chanctx_conf;
64 	u32 rate_flags = 0;
65 
66 	rcu_read_lock();
67 	chanctx_conf = rcu_dereference(tx->sdata->vif.chanctx_conf);
68 	if (chanctx_conf) {
69 		shift = ieee80211_chandef_get_shift(&chanctx_conf->def);
70 		rate_flags = ieee80211_chandef_rate_flags(&chanctx_conf->def);
71 	}
72 	rcu_read_unlock();
73 
74 	/* assume HW handles this */
75 	if (tx->rate.flags & (IEEE80211_TX_RC_MCS | IEEE80211_TX_RC_VHT_MCS))
76 		return 0;
77 
78 	/* uh huh? */
79 	if (WARN_ON_ONCE(tx->rate.idx < 0))
80 		return 0;
81 
82 	sband = local->hw.wiphy->bands[info->band];
83 	txrate = &sband->bitrates[tx->rate.idx];
84 
85 	erp = txrate->flags & IEEE80211_RATE_ERP_G;
86 
87 	/*
88 	 * data and mgmt (except PS Poll):
89 	 * - during CFP: 32768
90 	 * - during contention period:
91 	 *   if addr1 is group address: 0
92 	 *   if more fragments = 0 and addr1 is individual address: time to
93 	 *      transmit one ACK plus SIFS
94 	 *   if more fragments = 1 and addr1 is individual address: time to
95 	 *      transmit next fragment plus 2 x ACK plus 3 x SIFS
96 	 *
97 	 * IEEE 802.11, 9.6:
98 	 * - control response frame (CTS or ACK) shall be transmitted using the
99 	 *   same rate as the immediately previous frame in the frame exchange
100 	 *   sequence, if this rate belongs to the PHY mandatory rates, or else
101 	 *   at the highest possible rate belonging to the PHY rates in the
102 	 *   BSSBasicRateSet
103 	 */
104 	hdr = (struct ieee80211_hdr *)skb->data;
105 	if (ieee80211_is_ctl(hdr->frame_control)) {
106 		/* TODO: These control frames are not currently sent by
107 		 * mac80211, but should they be implemented, this function
108 		 * needs to be updated to support duration field calculation.
109 		 *
110 		 * RTS: time needed to transmit pending data/mgmt frame plus
111 		 *    one CTS frame plus one ACK frame plus 3 x SIFS
112 		 * CTS: duration of immediately previous RTS minus time
113 		 *    required to transmit CTS and its SIFS
114 		 * ACK: 0 if immediately previous directed data/mgmt had
115 		 *    more=0, with more=1 duration in ACK frame is duration
116 		 *    from previous frame minus time needed to transmit ACK
117 		 *    and its SIFS
118 		 * PS Poll: BIT(15) | BIT(14) | aid
119 		 */
120 		return 0;
121 	}
122 
123 	/* data/mgmt */
124 	if (0 /* FIX: data/mgmt during CFP */)
125 		return cpu_to_le16(32768);
126 
127 	if (group_addr) /* Group address as the destination - no ACK */
128 		return 0;
129 
130 	/* Individual destination address:
131 	 * IEEE 802.11, Ch. 9.6 (after IEEE 802.11g changes)
132 	 * CTS and ACK frames shall be transmitted using the highest rate in
133 	 * basic rate set that is less than or equal to the rate of the
134 	 * immediately previous frame and that is using the same modulation
135 	 * (CCK or OFDM). If no basic rate set matches with these requirements,
136 	 * the highest mandatory rate of the PHY that is less than or equal to
137 	 * the rate of the previous frame is used.
138 	 * Mandatory rates for IEEE 802.11g PHY: 1, 2, 5.5, 11, 6, 12, 24 Mbps
139 	 */
140 	rate = -1;
141 	/* use lowest available if everything fails */
142 	mrate = sband->bitrates[0].bitrate;
143 	for (i = 0; i < sband->n_bitrates; i++) {
144 		struct ieee80211_rate *r = &sband->bitrates[i];
145 
146 		if (r->bitrate > txrate->bitrate)
147 			break;
148 
149 		if ((rate_flags & r->flags) != rate_flags)
150 			continue;
151 
152 		if (tx->sdata->vif.bss_conf.basic_rates & BIT(i))
153 			rate = DIV_ROUND_UP(r->bitrate, 1 << shift);
154 
155 		switch (sband->band) {
156 		case NL80211_BAND_2GHZ: {
157 			u32 flag;
158 			if (tx->sdata->flags & IEEE80211_SDATA_OPERATING_GMODE)
159 				flag = IEEE80211_RATE_MANDATORY_G;
160 			else
161 				flag = IEEE80211_RATE_MANDATORY_B;
162 			if (r->flags & flag)
163 				mrate = r->bitrate;
164 			break;
165 		}
166 		case NL80211_BAND_5GHZ:
167 			if (r->flags & IEEE80211_RATE_MANDATORY_A)
168 				mrate = r->bitrate;
169 			break;
170 		case NL80211_BAND_60GHZ:
171 			/* TODO, for now fall through */
172 		case NUM_NL80211_BANDS:
173 			WARN_ON(1);
174 			break;
175 		}
176 	}
177 	if (rate == -1) {
178 		/* No matching basic rate found; use highest suitable mandatory
179 		 * PHY rate */
180 		rate = DIV_ROUND_UP(mrate, 1 << shift);
181 	}
182 
183 	/* Don't calculate ACKs for QoS Frames with NoAck Policy set */
184 	if (ieee80211_is_data_qos(hdr->frame_control) &&
185 	    *(ieee80211_get_qos_ctl(hdr)) & IEEE80211_QOS_CTL_ACK_POLICY_NOACK)
186 		dur = 0;
187 	else
188 		/* Time needed to transmit ACK
189 		 * (10 bytes + 4-byte FCS = 112 bits) plus SIFS; rounded up
190 		 * to closest integer */
191 		dur = ieee80211_frame_duration(sband->band, 10, rate, erp,
192 				tx->sdata->vif.bss_conf.use_short_preamble,
193 				shift);
194 
195 	if (next_frag_len) {
196 		/* Frame is fragmented: duration increases with time needed to
197 		 * transmit next fragment plus ACK and 2 x SIFS. */
198 		dur *= 2; /* ACK + SIFS */
199 		/* next fragment */
200 		dur += ieee80211_frame_duration(sband->band, next_frag_len,
201 				txrate->bitrate, erp,
202 				tx->sdata->vif.bss_conf.use_short_preamble,
203 				shift);
204 	}
205 
206 	return cpu_to_le16(dur);
207 }
208 
209 /* tx handlers */
210 static ieee80211_tx_result debug_noinline
211 ieee80211_tx_h_dynamic_ps(struct ieee80211_tx_data *tx)
212 {
213 	struct ieee80211_local *local = tx->local;
214 	struct ieee80211_if_managed *ifmgd;
215 
216 	/* driver doesn't support power save */
217 	if (!ieee80211_hw_check(&local->hw, SUPPORTS_PS))
218 		return TX_CONTINUE;
219 
220 	/* hardware does dynamic power save */
221 	if (ieee80211_hw_check(&local->hw, SUPPORTS_DYNAMIC_PS))
222 		return TX_CONTINUE;
223 
224 	/* dynamic power save disabled */
225 	if (local->hw.conf.dynamic_ps_timeout <= 0)
226 		return TX_CONTINUE;
227 
228 	/* we are scanning, don't enable power save */
229 	if (local->scanning)
230 		return TX_CONTINUE;
231 
232 	if (!local->ps_sdata)
233 		return TX_CONTINUE;
234 
235 	/* No point if we're going to suspend */
236 	if (local->quiescing)
237 		return TX_CONTINUE;
238 
239 	/* dynamic ps is supported only in managed mode */
240 	if (tx->sdata->vif.type != NL80211_IFTYPE_STATION)
241 		return TX_CONTINUE;
242 
243 	ifmgd = &tx->sdata->u.mgd;
244 
245 	/*
246 	 * Don't wakeup from power save if u-apsd is enabled, voip ac has
247 	 * u-apsd enabled and the frame is in voip class. This effectively
248 	 * means that even if all access categories have u-apsd enabled, in
249 	 * practise u-apsd is only used with the voip ac. This is a
250 	 * workaround for the case when received voip class packets do not
251 	 * have correct qos tag for some reason, due the network or the
252 	 * peer application.
253 	 *
254 	 * Note: ifmgd->uapsd_queues access is racy here. If the value is
255 	 * changed via debugfs, user needs to reassociate manually to have
256 	 * everything in sync.
257 	 */
258 	if ((ifmgd->flags & IEEE80211_STA_UAPSD_ENABLED) &&
259 	    (ifmgd->uapsd_queues & IEEE80211_WMM_IE_STA_QOSINFO_AC_VO) &&
260 	    skb_get_queue_mapping(tx->skb) == IEEE80211_AC_VO)
261 		return TX_CONTINUE;
262 
263 	if (local->hw.conf.flags & IEEE80211_CONF_PS) {
264 		ieee80211_stop_queues_by_reason(&local->hw,
265 						IEEE80211_MAX_QUEUE_MAP,
266 						IEEE80211_QUEUE_STOP_REASON_PS,
267 						false);
268 		ifmgd->flags &= ~IEEE80211_STA_NULLFUNC_ACKED;
269 		ieee80211_queue_work(&local->hw,
270 				     &local->dynamic_ps_disable_work);
271 	}
272 
273 	/* Don't restart the timer if we're not disassociated */
274 	if (!ifmgd->associated)
275 		return TX_CONTINUE;
276 
277 	mod_timer(&local->dynamic_ps_timer, jiffies +
278 		  msecs_to_jiffies(local->hw.conf.dynamic_ps_timeout));
279 
280 	return TX_CONTINUE;
281 }
282 
283 static ieee80211_tx_result debug_noinline
284 ieee80211_tx_h_check_assoc(struct ieee80211_tx_data *tx)
285 {
286 
287 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)tx->skb->data;
288 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(tx->skb);
289 	bool assoc = false;
290 
291 	if (unlikely(info->flags & IEEE80211_TX_CTL_INJECTED))
292 		return TX_CONTINUE;
293 
294 	if (unlikely(test_bit(SCAN_SW_SCANNING, &tx->local->scanning)) &&
295 	    test_bit(SDATA_STATE_OFFCHANNEL, &tx->sdata->state) &&
296 	    !ieee80211_is_probe_req(hdr->frame_control) &&
297 	    !ieee80211_is_nullfunc(hdr->frame_control))
298 		/*
299 		 * When software scanning only nullfunc frames (to notify
300 		 * the sleep state to the AP) and probe requests (for the
301 		 * active scan) are allowed, all other frames should not be
302 		 * sent and we should not get here, but if we do
303 		 * nonetheless, drop them to avoid sending them
304 		 * off-channel. See the link below and
305 		 * ieee80211_start_scan() for more.
306 		 *
307 		 * http://article.gmane.org/gmane.linux.kernel.wireless.general/30089
308 		 */
309 		return TX_DROP;
310 
311 	if (tx->sdata->vif.type == NL80211_IFTYPE_OCB)
312 		return TX_CONTINUE;
313 
314 	if (tx->sdata->vif.type == NL80211_IFTYPE_WDS)
315 		return TX_CONTINUE;
316 
317 	if (tx->flags & IEEE80211_TX_PS_BUFFERED)
318 		return TX_CONTINUE;
319 
320 	if (tx->sta)
321 		assoc = test_sta_flag(tx->sta, WLAN_STA_ASSOC);
322 
323 	if (likely(tx->flags & IEEE80211_TX_UNICAST)) {
324 		if (unlikely(!assoc &&
325 			     ieee80211_is_data(hdr->frame_control))) {
326 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG
327 			sdata_info(tx->sdata,
328 				   "dropped data frame to not associated station %pM\n",
329 				   hdr->addr1);
330 #endif
331 			I802_DEBUG_INC(tx->local->tx_handlers_drop_not_assoc);
332 			return TX_DROP;
333 		}
334 	} else if (unlikely(tx->sdata->vif.type == NL80211_IFTYPE_AP &&
335 			    ieee80211_is_data(hdr->frame_control) &&
336 			    !atomic_read(&tx->sdata->u.ap.num_mcast_sta))) {
337 		/*
338 		 * No associated STAs - no need to send multicast
339 		 * frames.
340 		 */
341 		return TX_DROP;
342 	}
343 
344 	return TX_CONTINUE;
345 }
346 
347 /* This function is called whenever the AP is about to exceed the maximum limit
348  * of buffered frames for power saving STAs. This situation should not really
349  * happen often during normal operation, so dropping the oldest buffered packet
350  * from each queue should be OK to make some room for new frames. */
351 static void purge_old_ps_buffers(struct ieee80211_local *local)
352 {
353 	int total = 0, purged = 0;
354 	struct sk_buff *skb;
355 	struct ieee80211_sub_if_data *sdata;
356 	struct sta_info *sta;
357 
358 	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
359 		struct ps_data *ps;
360 
361 		if (sdata->vif.type == NL80211_IFTYPE_AP)
362 			ps = &sdata->u.ap.ps;
363 		else if (ieee80211_vif_is_mesh(&sdata->vif))
364 			ps = &sdata->u.mesh.ps;
365 		else
366 			continue;
367 
368 		skb = skb_dequeue(&ps->bc_buf);
369 		if (skb) {
370 			purged++;
371 			ieee80211_free_txskb(&local->hw, skb);
372 		}
373 		total += skb_queue_len(&ps->bc_buf);
374 	}
375 
376 	/*
377 	 * Drop one frame from each station from the lowest-priority
378 	 * AC that has frames at all.
379 	 */
380 	list_for_each_entry_rcu(sta, &local->sta_list, list) {
381 		int ac;
382 
383 		for (ac = IEEE80211_AC_BK; ac >= IEEE80211_AC_VO; ac--) {
384 			skb = skb_dequeue(&sta->ps_tx_buf[ac]);
385 			total += skb_queue_len(&sta->ps_tx_buf[ac]);
386 			if (skb) {
387 				purged++;
388 				ieee80211_free_txskb(&local->hw, skb);
389 				break;
390 			}
391 		}
392 	}
393 
394 	local->total_ps_buffered = total;
395 	ps_dbg_hw(&local->hw, "PS buffers full - purged %d frames\n", purged);
396 }
397 
398 static ieee80211_tx_result
399 ieee80211_tx_h_multicast_ps_buf(struct ieee80211_tx_data *tx)
400 {
401 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(tx->skb);
402 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)tx->skb->data;
403 	struct ps_data *ps;
404 
405 	/*
406 	 * broadcast/multicast frame
407 	 *
408 	 * If any of the associated/peer stations is in power save mode,
409 	 * the frame is buffered to be sent after DTIM beacon frame.
410 	 * This is done either by the hardware or us.
411 	 */
412 
413 	/* powersaving STAs currently only in AP/VLAN/mesh mode */
414 	if (tx->sdata->vif.type == NL80211_IFTYPE_AP ||
415 	    tx->sdata->vif.type == NL80211_IFTYPE_AP_VLAN) {
416 		if (!tx->sdata->bss)
417 			return TX_CONTINUE;
418 
419 		ps = &tx->sdata->bss->ps;
420 	} else if (ieee80211_vif_is_mesh(&tx->sdata->vif)) {
421 		ps = &tx->sdata->u.mesh.ps;
422 	} else {
423 		return TX_CONTINUE;
424 	}
425 
426 
427 	/* no buffering for ordered frames */
428 	if (ieee80211_has_order(hdr->frame_control))
429 		return TX_CONTINUE;
430 
431 	if (ieee80211_is_probe_req(hdr->frame_control))
432 		return TX_CONTINUE;
433 
434 	if (ieee80211_hw_check(&tx->local->hw, QUEUE_CONTROL))
435 		info->hw_queue = tx->sdata->vif.cab_queue;
436 
437 	/* no stations in PS mode */
438 	if (!atomic_read(&ps->num_sta_ps))
439 		return TX_CONTINUE;
440 
441 	info->flags |= IEEE80211_TX_CTL_SEND_AFTER_DTIM;
442 
443 	/* device releases frame after DTIM beacon */
444 	if (!ieee80211_hw_check(&tx->local->hw, HOST_BROADCAST_PS_BUFFERING))
445 		return TX_CONTINUE;
446 
447 	/* buffered in mac80211 */
448 	if (tx->local->total_ps_buffered >= TOTAL_MAX_TX_BUFFER)
449 		purge_old_ps_buffers(tx->local);
450 
451 	if (skb_queue_len(&ps->bc_buf) >= AP_MAX_BC_BUFFER) {
452 		ps_dbg(tx->sdata,
453 		       "BC TX buffer full - dropping the oldest frame\n");
454 		ieee80211_free_txskb(&tx->local->hw, skb_dequeue(&ps->bc_buf));
455 	} else
456 		tx->local->total_ps_buffered++;
457 
458 	skb_queue_tail(&ps->bc_buf, tx->skb);
459 
460 	return TX_QUEUED;
461 }
462 
463 static int ieee80211_use_mfp(__le16 fc, struct sta_info *sta,
464 			     struct sk_buff *skb)
465 {
466 	if (!ieee80211_is_mgmt(fc))
467 		return 0;
468 
469 	if (sta == NULL || !test_sta_flag(sta, WLAN_STA_MFP))
470 		return 0;
471 
472 	if (!ieee80211_is_robust_mgmt_frame(skb))
473 		return 0;
474 
475 	return 1;
476 }
477 
478 static ieee80211_tx_result
479 ieee80211_tx_h_unicast_ps_buf(struct ieee80211_tx_data *tx)
480 {
481 	struct sta_info *sta = tx->sta;
482 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(tx->skb);
483 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)tx->skb->data;
484 	struct ieee80211_local *local = tx->local;
485 
486 	if (unlikely(!sta))
487 		return TX_CONTINUE;
488 
489 	if (unlikely((test_sta_flag(sta, WLAN_STA_PS_STA) ||
490 		      test_sta_flag(sta, WLAN_STA_PS_DRIVER) ||
491 		      test_sta_flag(sta, WLAN_STA_PS_DELIVER)) &&
492 		     !(info->flags & IEEE80211_TX_CTL_NO_PS_BUFFER))) {
493 		int ac = skb_get_queue_mapping(tx->skb);
494 
495 		if (ieee80211_is_mgmt(hdr->frame_control) &&
496 		    !ieee80211_is_bufferable_mmpdu(hdr->frame_control)) {
497 			info->flags |= IEEE80211_TX_CTL_NO_PS_BUFFER;
498 			return TX_CONTINUE;
499 		}
500 
501 		ps_dbg(sta->sdata, "STA %pM aid %d: PS buffer for AC %d\n",
502 		       sta->sta.addr, sta->sta.aid, ac);
503 		if (tx->local->total_ps_buffered >= TOTAL_MAX_TX_BUFFER)
504 			purge_old_ps_buffers(tx->local);
505 
506 		/* sync with ieee80211_sta_ps_deliver_wakeup */
507 		spin_lock(&sta->ps_lock);
508 		/*
509 		 * STA woke up the meantime and all the frames on ps_tx_buf have
510 		 * been queued to pending queue. No reordering can happen, go
511 		 * ahead and Tx the packet.
512 		 */
513 		if (!test_sta_flag(sta, WLAN_STA_PS_STA) &&
514 		    !test_sta_flag(sta, WLAN_STA_PS_DRIVER) &&
515 		    !test_sta_flag(sta, WLAN_STA_PS_DELIVER)) {
516 			spin_unlock(&sta->ps_lock);
517 			return TX_CONTINUE;
518 		}
519 
520 		if (skb_queue_len(&sta->ps_tx_buf[ac]) >= STA_MAX_TX_BUFFER) {
521 			struct sk_buff *old = skb_dequeue(&sta->ps_tx_buf[ac]);
522 			ps_dbg(tx->sdata,
523 			       "STA %pM TX buffer for AC %d full - dropping oldest frame\n",
524 			       sta->sta.addr, ac);
525 			ieee80211_free_txskb(&local->hw, old);
526 		} else
527 			tx->local->total_ps_buffered++;
528 
529 		info->control.jiffies = jiffies;
530 		info->control.vif = &tx->sdata->vif;
531 		info->flags |= IEEE80211_TX_INTFL_NEED_TXPROCESSING;
532 		info->flags &= ~IEEE80211_TX_TEMPORARY_FLAGS;
533 		skb_queue_tail(&sta->ps_tx_buf[ac], tx->skb);
534 		spin_unlock(&sta->ps_lock);
535 
536 		if (!timer_pending(&local->sta_cleanup))
537 			mod_timer(&local->sta_cleanup,
538 				  round_jiffies(jiffies +
539 						STA_INFO_CLEANUP_INTERVAL));
540 
541 		/*
542 		 * We queued up some frames, so the TIM bit might
543 		 * need to be set, recalculate it.
544 		 */
545 		sta_info_recalc_tim(sta);
546 
547 		return TX_QUEUED;
548 	} else if (unlikely(test_sta_flag(sta, WLAN_STA_PS_STA))) {
549 		ps_dbg(tx->sdata,
550 		       "STA %pM in PS mode, but polling/in SP -> send frame\n",
551 		       sta->sta.addr);
552 	}
553 
554 	return TX_CONTINUE;
555 }
556 
557 static ieee80211_tx_result debug_noinline
558 ieee80211_tx_h_ps_buf(struct ieee80211_tx_data *tx)
559 {
560 	if (unlikely(tx->flags & IEEE80211_TX_PS_BUFFERED))
561 		return TX_CONTINUE;
562 
563 	if (tx->flags & IEEE80211_TX_UNICAST)
564 		return ieee80211_tx_h_unicast_ps_buf(tx);
565 	else
566 		return ieee80211_tx_h_multicast_ps_buf(tx);
567 }
568 
569 static ieee80211_tx_result debug_noinline
570 ieee80211_tx_h_check_control_port_protocol(struct ieee80211_tx_data *tx)
571 {
572 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(tx->skb);
573 
574 	if (unlikely(tx->sdata->control_port_protocol == tx->skb->protocol)) {
575 		if (tx->sdata->control_port_no_encrypt)
576 			info->flags |= IEEE80211_TX_INTFL_DONT_ENCRYPT;
577 		info->control.flags |= IEEE80211_TX_CTRL_PORT_CTRL_PROTO;
578 		info->flags |= IEEE80211_TX_CTL_USE_MINRATE;
579 	}
580 
581 	return TX_CONTINUE;
582 }
583 
584 static ieee80211_tx_result debug_noinline
585 ieee80211_tx_h_select_key(struct ieee80211_tx_data *tx)
586 {
587 	struct ieee80211_key *key;
588 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(tx->skb);
589 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)tx->skb->data;
590 
591 	if (unlikely(info->flags & IEEE80211_TX_INTFL_DONT_ENCRYPT))
592 		tx->key = NULL;
593 	else if (tx->sta &&
594 		 (key = rcu_dereference(tx->sta->ptk[tx->sta->ptk_idx])))
595 		tx->key = key;
596 	else if (ieee80211_is_group_privacy_action(tx->skb) &&
597 		(key = rcu_dereference(tx->sdata->default_multicast_key)))
598 		tx->key = key;
599 	else if (ieee80211_is_mgmt(hdr->frame_control) &&
600 		 is_multicast_ether_addr(hdr->addr1) &&
601 		 ieee80211_is_robust_mgmt_frame(tx->skb) &&
602 		 (key = rcu_dereference(tx->sdata->default_mgmt_key)))
603 		tx->key = key;
604 	else if (is_multicast_ether_addr(hdr->addr1) &&
605 		 (key = rcu_dereference(tx->sdata->default_multicast_key)))
606 		tx->key = key;
607 	else if (!is_multicast_ether_addr(hdr->addr1) &&
608 		 (key = rcu_dereference(tx->sdata->default_unicast_key)))
609 		tx->key = key;
610 	else
611 		tx->key = NULL;
612 
613 	if (tx->key) {
614 		bool skip_hw = false;
615 
616 		/* TODO: add threshold stuff again */
617 
618 		switch (tx->key->conf.cipher) {
619 		case WLAN_CIPHER_SUITE_WEP40:
620 		case WLAN_CIPHER_SUITE_WEP104:
621 		case WLAN_CIPHER_SUITE_TKIP:
622 			if (!ieee80211_is_data_present(hdr->frame_control))
623 				tx->key = NULL;
624 			break;
625 		case WLAN_CIPHER_SUITE_CCMP:
626 		case WLAN_CIPHER_SUITE_CCMP_256:
627 		case WLAN_CIPHER_SUITE_GCMP:
628 		case WLAN_CIPHER_SUITE_GCMP_256:
629 			if (!ieee80211_is_data_present(hdr->frame_control) &&
630 			    !ieee80211_use_mfp(hdr->frame_control, tx->sta,
631 					       tx->skb) &&
632 			    !ieee80211_is_group_privacy_action(tx->skb))
633 				tx->key = NULL;
634 			else
635 				skip_hw = (tx->key->conf.flags &
636 					   IEEE80211_KEY_FLAG_SW_MGMT_TX) &&
637 					ieee80211_is_mgmt(hdr->frame_control);
638 			break;
639 		case WLAN_CIPHER_SUITE_AES_CMAC:
640 		case WLAN_CIPHER_SUITE_BIP_CMAC_256:
641 		case WLAN_CIPHER_SUITE_BIP_GMAC_128:
642 		case WLAN_CIPHER_SUITE_BIP_GMAC_256:
643 			if (!ieee80211_is_mgmt(hdr->frame_control))
644 				tx->key = NULL;
645 			break;
646 		}
647 
648 		if (unlikely(tx->key && tx->key->flags & KEY_FLAG_TAINTED &&
649 			     !ieee80211_is_deauth(hdr->frame_control)))
650 			return TX_DROP;
651 
652 		if (!skip_hw && tx->key &&
653 		    tx->key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE)
654 			info->control.hw_key = &tx->key->conf;
655 	}
656 
657 	return TX_CONTINUE;
658 }
659 
660 static ieee80211_tx_result debug_noinline
661 ieee80211_tx_h_rate_ctrl(struct ieee80211_tx_data *tx)
662 {
663 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(tx->skb);
664 	struct ieee80211_hdr *hdr = (void *)tx->skb->data;
665 	struct ieee80211_supported_band *sband;
666 	u32 len;
667 	struct ieee80211_tx_rate_control txrc;
668 	struct ieee80211_sta_rates *ratetbl = NULL;
669 	bool assoc = false;
670 
671 	memset(&txrc, 0, sizeof(txrc));
672 
673 	sband = tx->local->hw.wiphy->bands[info->band];
674 
675 	len = min_t(u32, tx->skb->len + FCS_LEN,
676 			 tx->local->hw.wiphy->frag_threshold);
677 
678 	/* set up the tx rate control struct we give the RC algo */
679 	txrc.hw = &tx->local->hw;
680 	txrc.sband = sband;
681 	txrc.bss_conf = &tx->sdata->vif.bss_conf;
682 	txrc.skb = tx->skb;
683 	txrc.reported_rate.idx = -1;
684 	txrc.rate_idx_mask = tx->sdata->rc_rateidx_mask[info->band];
685 	if (txrc.rate_idx_mask == (1 << sband->n_bitrates) - 1)
686 		txrc.max_rate_idx = -1;
687 	else
688 		txrc.max_rate_idx = fls(txrc.rate_idx_mask) - 1;
689 
690 	if (tx->sdata->rc_has_mcs_mask[info->band])
691 		txrc.rate_idx_mcs_mask =
692 			tx->sdata->rc_rateidx_mcs_mask[info->band];
693 
694 	txrc.bss = (tx->sdata->vif.type == NL80211_IFTYPE_AP ||
695 		    tx->sdata->vif.type == NL80211_IFTYPE_MESH_POINT ||
696 		    tx->sdata->vif.type == NL80211_IFTYPE_ADHOC ||
697 		    tx->sdata->vif.type == NL80211_IFTYPE_OCB);
698 
699 	/* set up RTS protection if desired */
700 	if (len > tx->local->hw.wiphy->rts_threshold) {
701 		txrc.rts = true;
702 	}
703 
704 	info->control.use_rts = txrc.rts;
705 	info->control.use_cts_prot = tx->sdata->vif.bss_conf.use_cts_prot;
706 
707 	/*
708 	 * Use short preamble if the BSS can handle it, but not for
709 	 * management frames unless we know the receiver can handle
710 	 * that -- the management frame might be to a station that
711 	 * just wants a probe response.
712 	 */
713 	if (tx->sdata->vif.bss_conf.use_short_preamble &&
714 	    (ieee80211_is_data(hdr->frame_control) ||
715 	     (tx->sta && test_sta_flag(tx->sta, WLAN_STA_SHORT_PREAMBLE))))
716 		txrc.short_preamble = true;
717 
718 	info->control.short_preamble = txrc.short_preamble;
719 
720 	/* don't ask rate control when rate already injected via radiotap */
721 	if (info->control.flags & IEEE80211_TX_CTRL_RATE_INJECT)
722 		return TX_CONTINUE;
723 
724 	if (tx->sta)
725 		assoc = test_sta_flag(tx->sta, WLAN_STA_ASSOC);
726 
727 	/*
728 	 * Lets not bother rate control if we're associated and cannot
729 	 * talk to the sta. This should not happen.
730 	 */
731 	if (WARN(test_bit(SCAN_SW_SCANNING, &tx->local->scanning) && assoc &&
732 		 !rate_usable_index_exists(sband, &tx->sta->sta),
733 		 "%s: Dropped data frame as no usable bitrate found while "
734 		 "scanning and associated. Target station: "
735 		 "%pM on %d GHz band\n",
736 		 tx->sdata->name, hdr->addr1,
737 		 info->band ? 5 : 2))
738 		return TX_DROP;
739 
740 	/*
741 	 * If we're associated with the sta at this point we know we can at
742 	 * least send the frame at the lowest bit rate.
743 	 */
744 	rate_control_get_rate(tx->sdata, tx->sta, &txrc);
745 
746 	if (tx->sta && !info->control.skip_table)
747 		ratetbl = rcu_dereference(tx->sta->sta.rates);
748 
749 	if (unlikely(info->control.rates[0].idx < 0)) {
750 		if (ratetbl) {
751 			struct ieee80211_tx_rate rate = {
752 				.idx = ratetbl->rate[0].idx,
753 				.flags = ratetbl->rate[0].flags,
754 				.count = ratetbl->rate[0].count
755 			};
756 
757 			if (ratetbl->rate[0].idx < 0)
758 				return TX_DROP;
759 
760 			tx->rate = rate;
761 		} else {
762 			return TX_DROP;
763 		}
764 	} else {
765 		tx->rate = info->control.rates[0];
766 	}
767 
768 	if (txrc.reported_rate.idx < 0) {
769 		txrc.reported_rate = tx->rate;
770 		if (tx->sta && ieee80211_is_data(hdr->frame_control))
771 			tx->sta->tx_stats.last_rate = txrc.reported_rate;
772 	} else if (tx->sta)
773 		tx->sta->tx_stats.last_rate = txrc.reported_rate;
774 
775 	if (ratetbl)
776 		return TX_CONTINUE;
777 
778 	if (unlikely(!info->control.rates[0].count))
779 		info->control.rates[0].count = 1;
780 
781 	if (WARN_ON_ONCE((info->control.rates[0].count > 1) &&
782 			 (info->flags & IEEE80211_TX_CTL_NO_ACK)))
783 		info->control.rates[0].count = 1;
784 
785 	return TX_CONTINUE;
786 }
787 
788 static __le16 ieee80211_tx_next_seq(struct sta_info *sta, int tid)
789 {
790 	u16 *seq = &sta->tid_seq[tid];
791 	__le16 ret = cpu_to_le16(*seq);
792 
793 	/* Increase the sequence number. */
794 	*seq = (*seq + 0x10) & IEEE80211_SCTL_SEQ;
795 
796 	return ret;
797 }
798 
799 static struct txq_info *ieee80211_get_txq(struct ieee80211_local *local,
800 					  struct ieee80211_vif *vif,
801 					  struct ieee80211_sta *pubsta,
802 					  struct sk_buff *skb)
803 {
804 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
805 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
806 	struct ieee80211_txq *txq = NULL;
807 
808 	if ((info->flags & IEEE80211_TX_CTL_SEND_AFTER_DTIM) ||
809 	    (info->control.flags & IEEE80211_TX_CTRL_PS_RESPONSE))
810 		return NULL;
811 
812 	if (!ieee80211_is_data(hdr->frame_control))
813 		return NULL;
814 
815 	if (pubsta) {
816 		u8 tid = skb->priority & IEEE80211_QOS_CTL_TID_MASK;
817 
818 		txq = pubsta->txq[tid];
819 	} else if (vif) {
820 		txq = vif->txq;
821 	}
822 
823 	if (!txq)
824 		return NULL;
825 
826 	return to_txq_info(txq);
827 }
828 
829 static ieee80211_tx_result debug_noinline
830 ieee80211_tx_h_sequence(struct ieee80211_tx_data *tx)
831 {
832 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(tx->skb);
833 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)tx->skb->data;
834 	u8 *qc;
835 	int tid;
836 
837 	/*
838 	 * Packet injection may want to control the sequence
839 	 * number, if we have no matching interface then we
840 	 * neither assign one ourselves nor ask the driver to.
841 	 */
842 	if (unlikely(info->control.vif->type == NL80211_IFTYPE_MONITOR))
843 		return TX_CONTINUE;
844 
845 	if (unlikely(ieee80211_is_ctl(hdr->frame_control)))
846 		return TX_CONTINUE;
847 
848 	if (ieee80211_hdrlen(hdr->frame_control) < 24)
849 		return TX_CONTINUE;
850 
851 	if (ieee80211_is_qos_nullfunc(hdr->frame_control))
852 		return TX_CONTINUE;
853 
854 	/*
855 	 * Anything but QoS data that has a sequence number field
856 	 * (is long enough) gets a sequence number from the global
857 	 * counter.  QoS data frames with a multicast destination
858 	 * also use the global counter (802.11-2012 9.3.2.10).
859 	 */
860 	if (!ieee80211_is_data_qos(hdr->frame_control) ||
861 	    is_multicast_ether_addr(hdr->addr1)) {
862 		/* driver should assign sequence number */
863 		info->flags |= IEEE80211_TX_CTL_ASSIGN_SEQ;
864 		/* for pure STA mode without beacons, we can do it */
865 		hdr->seq_ctrl = cpu_to_le16(tx->sdata->sequence_number);
866 		tx->sdata->sequence_number += 0x10;
867 		if (tx->sta)
868 			tx->sta->tx_stats.msdu[IEEE80211_NUM_TIDS]++;
869 		return TX_CONTINUE;
870 	}
871 
872 	/*
873 	 * This should be true for injected/management frames only, for
874 	 * management frames we have set the IEEE80211_TX_CTL_ASSIGN_SEQ
875 	 * above since they are not QoS-data frames.
876 	 */
877 	if (!tx->sta)
878 		return TX_CONTINUE;
879 
880 	/* include per-STA, per-TID sequence counter */
881 
882 	qc = ieee80211_get_qos_ctl(hdr);
883 	tid = *qc & IEEE80211_QOS_CTL_TID_MASK;
884 	tx->sta->tx_stats.msdu[tid]++;
885 
886 	if (!ieee80211_get_txq(tx->local, info->control.vif, &tx->sta->sta,
887 			       tx->skb))
888 		hdr->seq_ctrl = ieee80211_tx_next_seq(tx->sta, tid);
889 
890 	return TX_CONTINUE;
891 }
892 
893 static int ieee80211_fragment(struct ieee80211_tx_data *tx,
894 			      struct sk_buff *skb, int hdrlen,
895 			      int frag_threshold)
896 {
897 	struct ieee80211_local *local = tx->local;
898 	struct ieee80211_tx_info *info;
899 	struct sk_buff *tmp;
900 	int per_fragm = frag_threshold - hdrlen - FCS_LEN;
901 	int pos = hdrlen + per_fragm;
902 	int rem = skb->len - hdrlen - per_fragm;
903 
904 	if (WARN_ON(rem < 0))
905 		return -EINVAL;
906 
907 	/* first fragment was already added to queue by caller */
908 
909 	while (rem) {
910 		int fraglen = per_fragm;
911 
912 		if (fraglen > rem)
913 			fraglen = rem;
914 		rem -= fraglen;
915 		tmp = dev_alloc_skb(local->tx_headroom +
916 				    frag_threshold +
917 				    tx->sdata->encrypt_headroom +
918 				    IEEE80211_ENCRYPT_TAILROOM);
919 		if (!tmp)
920 			return -ENOMEM;
921 
922 		__skb_queue_tail(&tx->skbs, tmp);
923 
924 		skb_reserve(tmp,
925 			    local->tx_headroom + tx->sdata->encrypt_headroom);
926 
927 		/* copy control information */
928 		memcpy(tmp->cb, skb->cb, sizeof(tmp->cb));
929 
930 		info = IEEE80211_SKB_CB(tmp);
931 		info->flags &= ~(IEEE80211_TX_CTL_CLEAR_PS_FILT |
932 				 IEEE80211_TX_CTL_FIRST_FRAGMENT);
933 
934 		if (rem)
935 			info->flags |= IEEE80211_TX_CTL_MORE_FRAMES;
936 
937 		skb_copy_queue_mapping(tmp, skb);
938 		tmp->priority = skb->priority;
939 		tmp->dev = skb->dev;
940 
941 		/* copy header and data */
942 		memcpy(skb_put(tmp, hdrlen), skb->data, hdrlen);
943 		memcpy(skb_put(tmp, fraglen), skb->data + pos, fraglen);
944 
945 		pos += fraglen;
946 	}
947 
948 	/* adjust first fragment's length */
949 	skb_trim(skb, hdrlen + per_fragm);
950 	return 0;
951 }
952 
953 static ieee80211_tx_result debug_noinline
954 ieee80211_tx_h_fragment(struct ieee80211_tx_data *tx)
955 {
956 	struct sk_buff *skb = tx->skb;
957 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
958 	struct ieee80211_hdr *hdr = (void *)skb->data;
959 	int frag_threshold = tx->local->hw.wiphy->frag_threshold;
960 	int hdrlen;
961 	int fragnum;
962 
963 	/* no matter what happens, tx->skb moves to tx->skbs */
964 	__skb_queue_tail(&tx->skbs, skb);
965 	tx->skb = NULL;
966 
967 	if (info->flags & IEEE80211_TX_CTL_DONTFRAG)
968 		return TX_CONTINUE;
969 
970 	if (tx->local->ops->set_frag_threshold)
971 		return TX_CONTINUE;
972 
973 	/*
974 	 * Warn when submitting a fragmented A-MPDU frame and drop it.
975 	 * This scenario is handled in ieee80211_tx_prepare but extra
976 	 * caution taken here as fragmented ampdu may cause Tx stop.
977 	 */
978 	if (WARN_ON(info->flags & IEEE80211_TX_CTL_AMPDU))
979 		return TX_DROP;
980 
981 	hdrlen = ieee80211_hdrlen(hdr->frame_control);
982 
983 	/* internal error, why isn't DONTFRAG set? */
984 	if (WARN_ON(skb->len + FCS_LEN <= frag_threshold))
985 		return TX_DROP;
986 
987 	/*
988 	 * Now fragment the frame. This will allocate all the fragments and
989 	 * chain them (using skb as the first fragment) to skb->next.
990 	 * During transmission, we will remove the successfully transmitted
991 	 * fragments from this list. When the low-level driver rejects one
992 	 * of the fragments then we will simply pretend to accept the skb
993 	 * but store it away as pending.
994 	 */
995 	if (ieee80211_fragment(tx, skb, hdrlen, frag_threshold))
996 		return TX_DROP;
997 
998 	/* update duration/seq/flags of fragments */
999 	fragnum = 0;
1000 
1001 	skb_queue_walk(&tx->skbs, skb) {
1002 		const __le16 morefrags = cpu_to_le16(IEEE80211_FCTL_MOREFRAGS);
1003 
1004 		hdr = (void *)skb->data;
1005 		info = IEEE80211_SKB_CB(skb);
1006 
1007 		if (!skb_queue_is_last(&tx->skbs, skb)) {
1008 			hdr->frame_control |= morefrags;
1009 			/*
1010 			 * No multi-rate retries for fragmented frames, that
1011 			 * would completely throw off the NAV at other STAs.
1012 			 */
1013 			info->control.rates[1].idx = -1;
1014 			info->control.rates[2].idx = -1;
1015 			info->control.rates[3].idx = -1;
1016 			BUILD_BUG_ON(IEEE80211_TX_MAX_RATES != 4);
1017 			info->flags &= ~IEEE80211_TX_CTL_RATE_CTRL_PROBE;
1018 		} else {
1019 			hdr->frame_control &= ~morefrags;
1020 		}
1021 		hdr->seq_ctrl |= cpu_to_le16(fragnum & IEEE80211_SCTL_FRAG);
1022 		fragnum++;
1023 	}
1024 
1025 	return TX_CONTINUE;
1026 }
1027 
1028 static ieee80211_tx_result debug_noinline
1029 ieee80211_tx_h_stats(struct ieee80211_tx_data *tx)
1030 {
1031 	struct sk_buff *skb;
1032 	int ac = -1;
1033 
1034 	if (!tx->sta)
1035 		return TX_CONTINUE;
1036 
1037 	skb_queue_walk(&tx->skbs, skb) {
1038 		ac = skb_get_queue_mapping(skb);
1039 		tx->sta->tx_stats.bytes[ac] += skb->len;
1040 	}
1041 	if (ac >= 0)
1042 		tx->sta->tx_stats.packets[ac]++;
1043 
1044 	return TX_CONTINUE;
1045 }
1046 
1047 static ieee80211_tx_result debug_noinline
1048 ieee80211_tx_h_encrypt(struct ieee80211_tx_data *tx)
1049 {
1050 	if (!tx->key)
1051 		return TX_CONTINUE;
1052 
1053 	switch (tx->key->conf.cipher) {
1054 	case WLAN_CIPHER_SUITE_WEP40:
1055 	case WLAN_CIPHER_SUITE_WEP104:
1056 		return ieee80211_crypto_wep_encrypt(tx);
1057 	case WLAN_CIPHER_SUITE_TKIP:
1058 		return ieee80211_crypto_tkip_encrypt(tx);
1059 	case WLAN_CIPHER_SUITE_CCMP:
1060 		return ieee80211_crypto_ccmp_encrypt(
1061 			tx, IEEE80211_CCMP_MIC_LEN);
1062 	case WLAN_CIPHER_SUITE_CCMP_256:
1063 		return ieee80211_crypto_ccmp_encrypt(
1064 			tx, IEEE80211_CCMP_256_MIC_LEN);
1065 	case WLAN_CIPHER_SUITE_AES_CMAC:
1066 		return ieee80211_crypto_aes_cmac_encrypt(tx);
1067 	case WLAN_CIPHER_SUITE_BIP_CMAC_256:
1068 		return ieee80211_crypto_aes_cmac_256_encrypt(tx);
1069 	case WLAN_CIPHER_SUITE_BIP_GMAC_128:
1070 	case WLAN_CIPHER_SUITE_BIP_GMAC_256:
1071 		return ieee80211_crypto_aes_gmac_encrypt(tx);
1072 	case WLAN_CIPHER_SUITE_GCMP:
1073 	case WLAN_CIPHER_SUITE_GCMP_256:
1074 		return ieee80211_crypto_gcmp_encrypt(tx);
1075 	default:
1076 		return ieee80211_crypto_hw_encrypt(tx);
1077 	}
1078 
1079 	return TX_DROP;
1080 }
1081 
1082 static ieee80211_tx_result debug_noinline
1083 ieee80211_tx_h_calculate_duration(struct ieee80211_tx_data *tx)
1084 {
1085 	struct sk_buff *skb;
1086 	struct ieee80211_hdr *hdr;
1087 	int next_len;
1088 	bool group_addr;
1089 
1090 	skb_queue_walk(&tx->skbs, skb) {
1091 		hdr = (void *) skb->data;
1092 		if (unlikely(ieee80211_is_pspoll(hdr->frame_control)))
1093 			break; /* must not overwrite AID */
1094 		if (!skb_queue_is_last(&tx->skbs, skb)) {
1095 			struct sk_buff *next = skb_queue_next(&tx->skbs, skb);
1096 			next_len = next->len;
1097 		} else
1098 			next_len = 0;
1099 		group_addr = is_multicast_ether_addr(hdr->addr1);
1100 
1101 		hdr->duration_id =
1102 			ieee80211_duration(tx, skb, group_addr, next_len);
1103 	}
1104 
1105 	return TX_CONTINUE;
1106 }
1107 
1108 /* actual transmit path */
1109 
1110 static bool ieee80211_tx_prep_agg(struct ieee80211_tx_data *tx,
1111 				  struct sk_buff *skb,
1112 				  struct ieee80211_tx_info *info,
1113 				  struct tid_ampdu_tx *tid_tx,
1114 				  int tid)
1115 {
1116 	bool queued = false;
1117 	bool reset_agg_timer = false;
1118 	struct sk_buff *purge_skb = NULL;
1119 
1120 	if (test_bit(HT_AGG_STATE_OPERATIONAL, &tid_tx->state)) {
1121 		info->flags |= IEEE80211_TX_CTL_AMPDU;
1122 		reset_agg_timer = true;
1123 	} else if (test_bit(HT_AGG_STATE_WANT_START, &tid_tx->state)) {
1124 		/*
1125 		 * nothing -- this aggregation session is being started
1126 		 * but that might still fail with the driver
1127 		 */
1128 	} else if (!tx->sta->sta.txq[tid]) {
1129 		spin_lock(&tx->sta->lock);
1130 		/*
1131 		 * Need to re-check now, because we may get here
1132 		 *
1133 		 *  1) in the window during which the setup is actually
1134 		 *     already done, but not marked yet because not all
1135 		 *     packets are spliced over to the driver pending
1136 		 *     queue yet -- if this happened we acquire the lock
1137 		 *     either before or after the splice happens, but
1138 		 *     need to recheck which of these cases happened.
1139 		 *
1140 		 *  2) during session teardown, if the OPERATIONAL bit
1141 		 *     was cleared due to the teardown but the pointer
1142 		 *     hasn't been assigned NULL yet (or we loaded it
1143 		 *     before it was assigned) -- in this case it may
1144 		 *     now be NULL which means we should just let the
1145 		 *     packet pass through because splicing the frames
1146 		 *     back is already done.
1147 		 */
1148 		tid_tx = rcu_dereference_protected_tid_tx(tx->sta, tid);
1149 
1150 		if (!tid_tx) {
1151 			/* do nothing, let packet pass through */
1152 		} else if (test_bit(HT_AGG_STATE_OPERATIONAL, &tid_tx->state)) {
1153 			info->flags |= IEEE80211_TX_CTL_AMPDU;
1154 			reset_agg_timer = true;
1155 		} else {
1156 			queued = true;
1157 			if (info->flags & IEEE80211_TX_CTL_NO_PS_BUFFER) {
1158 				clear_sta_flag(tx->sta, WLAN_STA_SP);
1159 				ps_dbg(tx->sta->sdata,
1160 				       "STA %pM aid %d: SP frame queued, close the SP w/o telling the peer\n",
1161 				       tx->sta->sta.addr, tx->sta->sta.aid);
1162 			}
1163 			info->control.vif = &tx->sdata->vif;
1164 			info->flags |= IEEE80211_TX_INTFL_NEED_TXPROCESSING;
1165 			info->flags &= ~IEEE80211_TX_TEMPORARY_FLAGS;
1166 			__skb_queue_tail(&tid_tx->pending, skb);
1167 			if (skb_queue_len(&tid_tx->pending) > STA_MAX_TX_BUFFER)
1168 				purge_skb = __skb_dequeue(&tid_tx->pending);
1169 		}
1170 		spin_unlock(&tx->sta->lock);
1171 
1172 		if (purge_skb)
1173 			ieee80211_free_txskb(&tx->local->hw, purge_skb);
1174 	}
1175 
1176 	/* reset session timer */
1177 	if (reset_agg_timer && tid_tx->timeout)
1178 		tid_tx->last_tx = jiffies;
1179 
1180 	return queued;
1181 }
1182 
1183 /*
1184  * initialises @tx
1185  * pass %NULL for the station if unknown, a valid pointer if known
1186  * or an ERR_PTR() if the station is known not to exist
1187  */
1188 static ieee80211_tx_result
1189 ieee80211_tx_prepare(struct ieee80211_sub_if_data *sdata,
1190 		     struct ieee80211_tx_data *tx,
1191 		     struct sta_info *sta, struct sk_buff *skb)
1192 {
1193 	struct ieee80211_local *local = sdata->local;
1194 	struct ieee80211_hdr *hdr;
1195 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
1196 	int tid;
1197 	u8 *qc;
1198 
1199 	memset(tx, 0, sizeof(*tx));
1200 	tx->skb = skb;
1201 	tx->local = local;
1202 	tx->sdata = sdata;
1203 	__skb_queue_head_init(&tx->skbs);
1204 
1205 	/*
1206 	 * If this flag is set to true anywhere, and we get here,
1207 	 * we are doing the needed processing, so remove the flag
1208 	 * now.
1209 	 */
1210 	info->flags &= ~IEEE80211_TX_INTFL_NEED_TXPROCESSING;
1211 
1212 	hdr = (struct ieee80211_hdr *) skb->data;
1213 
1214 	if (likely(sta)) {
1215 		if (!IS_ERR(sta))
1216 			tx->sta = sta;
1217 	} else {
1218 		if (sdata->vif.type == NL80211_IFTYPE_AP_VLAN) {
1219 			tx->sta = rcu_dereference(sdata->u.vlan.sta);
1220 			if (!tx->sta && sdata->wdev.use_4addr)
1221 				return TX_DROP;
1222 		} else if (info->flags & (IEEE80211_TX_INTFL_NL80211_FRAME_TX |
1223 					  IEEE80211_TX_CTL_INJECTED) ||
1224 			   tx->sdata->control_port_protocol == tx->skb->protocol) {
1225 			tx->sta = sta_info_get_bss(sdata, hdr->addr1);
1226 		}
1227 		if (!tx->sta && !is_multicast_ether_addr(hdr->addr1))
1228 			tx->sta = sta_info_get(sdata, hdr->addr1);
1229 	}
1230 
1231 	if (tx->sta && ieee80211_is_data_qos(hdr->frame_control) &&
1232 	    !ieee80211_is_qos_nullfunc(hdr->frame_control) &&
1233 	    ieee80211_hw_check(&local->hw, AMPDU_AGGREGATION) &&
1234 	    !ieee80211_hw_check(&local->hw, TX_AMPDU_SETUP_IN_HW)) {
1235 		struct tid_ampdu_tx *tid_tx;
1236 
1237 		qc = ieee80211_get_qos_ctl(hdr);
1238 		tid = *qc & IEEE80211_QOS_CTL_TID_MASK;
1239 
1240 		tid_tx = rcu_dereference(tx->sta->ampdu_mlme.tid_tx[tid]);
1241 		if (tid_tx) {
1242 			bool queued;
1243 
1244 			queued = ieee80211_tx_prep_agg(tx, skb, info,
1245 						       tid_tx, tid);
1246 
1247 			if (unlikely(queued))
1248 				return TX_QUEUED;
1249 		}
1250 	}
1251 
1252 	if (is_multicast_ether_addr(hdr->addr1)) {
1253 		tx->flags &= ~IEEE80211_TX_UNICAST;
1254 		info->flags |= IEEE80211_TX_CTL_NO_ACK;
1255 	} else
1256 		tx->flags |= IEEE80211_TX_UNICAST;
1257 
1258 	if (!(info->flags & IEEE80211_TX_CTL_DONTFRAG)) {
1259 		if (!(tx->flags & IEEE80211_TX_UNICAST) ||
1260 		    skb->len + FCS_LEN <= local->hw.wiphy->frag_threshold ||
1261 		    info->flags & IEEE80211_TX_CTL_AMPDU)
1262 			info->flags |= IEEE80211_TX_CTL_DONTFRAG;
1263 	}
1264 
1265 	if (!tx->sta)
1266 		info->flags |= IEEE80211_TX_CTL_CLEAR_PS_FILT;
1267 	else if (test_and_clear_sta_flag(tx->sta, WLAN_STA_CLEAR_PS_FILT)) {
1268 		info->flags |= IEEE80211_TX_CTL_CLEAR_PS_FILT;
1269 		ieee80211_check_fast_xmit(tx->sta);
1270 	}
1271 
1272 	info->flags |= IEEE80211_TX_CTL_FIRST_FRAGMENT;
1273 
1274 	return TX_CONTINUE;
1275 }
1276 
1277 static void ieee80211_set_skb_enqueue_time(struct sk_buff *skb)
1278 {
1279 	IEEE80211_SKB_CB(skb)->control.enqueue_time = codel_get_time();
1280 }
1281 
1282 static void ieee80211_set_skb_vif(struct sk_buff *skb, struct txq_info *txqi)
1283 {
1284 	IEEE80211_SKB_CB(skb)->control.vif = txqi->txq.vif;
1285 }
1286 
1287 static u32 codel_skb_len_func(const struct sk_buff *skb)
1288 {
1289 	return skb->len;
1290 }
1291 
1292 static codel_time_t codel_skb_time_func(const struct sk_buff *skb)
1293 {
1294 	const struct ieee80211_tx_info *info;
1295 
1296 	info = (const struct ieee80211_tx_info *)skb->cb;
1297 	return info->control.enqueue_time;
1298 }
1299 
1300 static struct sk_buff *codel_dequeue_func(struct codel_vars *cvars,
1301 					  void *ctx)
1302 {
1303 	struct ieee80211_local *local;
1304 	struct txq_info *txqi;
1305 	struct fq *fq;
1306 	struct fq_flow *flow;
1307 
1308 	txqi = ctx;
1309 	local = vif_to_sdata(txqi->txq.vif)->local;
1310 	fq = &local->fq;
1311 
1312 	if (cvars == &txqi->def_cvars)
1313 		flow = &txqi->def_flow;
1314 	else
1315 		flow = &fq->flows[cvars - local->cvars];
1316 
1317 	return fq_flow_dequeue(fq, flow);
1318 }
1319 
1320 static void codel_drop_func(struct sk_buff *skb,
1321 			    void *ctx)
1322 {
1323 	struct ieee80211_local *local;
1324 	struct ieee80211_hw *hw;
1325 	struct txq_info *txqi;
1326 
1327 	txqi = ctx;
1328 	local = vif_to_sdata(txqi->txq.vif)->local;
1329 	hw = &local->hw;
1330 
1331 	ieee80211_free_txskb(hw, skb);
1332 }
1333 
1334 static struct sk_buff *fq_tin_dequeue_func(struct fq *fq,
1335 					   struct fq_tin *tin,
1336 					   struct fq_flow *flow)
1337 {
1338 	struct ieee80211_local *local;
1339 	struct txq_info *txqi;
1340 	struct codel_vars *cvars;
1341 	struct codel_params *cparams;
1342 	struct codel_stats *cstats;
1343 
1344 	local = container_of(fq, struct ieee80211_local, fq);
1345 	txqi = container_of(tin, struct txq_info, tin);
1346 	cparams = &local->cparams;
1347 	cstats = &local->cstats;
1348 
1349 	if (flow == &txqi->def_flow)
1350 		cvars = &txqi->def_cvars;
1351 	else
1352 		cvars = &local->cvars[flow - fq->flows];
1353 
1354 	return codel_dequeue(txqi,
1355 			     &flow->backlog,
1356 			     cparams,
1357 			     cvars,
1358 			     cstats,
1359 			     codel_skb_len_func,
1360 			     codel_skb_time_func,
1361 			     codel_drop_func,
1362 			     codel_dequeue_func);
1363 }
1364 
1365 static void fq_skb_free_func(struct fq *fq,
1366 			     struct fq_tin *tin,
1367 			     struct fq_flow *flow,
1368 			     struct sk_buff *skb)
1369 {
1370 	struct ieee80211_local *local;
1371 
1372 	local = container_of(fq, struct ieee80211_local, fq);
1373 	ieee80211_free_txskb(&local->hw, skb);
1374 }
1375 
1376 static struct fq_flow *fq_flow_get_default_func(struct fq *fq,
1377 						struct fq_tin *tin,
1378 						int idx,
1379 						struct sk_buff *skb)
1380 {
1381 	struct txq_info *txqi;
1382 
1383 	txqi = container_of(tin, struct txq_info, tin);
1384 	return &txqi->def_flow;
1385 }
1386 
1387 static void ieee80211_txq_enqueue(struct ieee80211_local *local,
1388 				  struct txq_info *txqi,
1389 				  struct sk_buff *skb)
1390 {
1391 	struct fq *fq = &local->fq;
1392 	struct fq_tin *tin = &txqi->tin;
1393 
1394 	ieee80211_set_skb_enqueue_time(skb);
1395 	fq_tin_enqueue(fq, tin, skb,
1396 		       fq_skb_free_func,
1397 		       fq_flow_get_default_func);
1398 }
1399 
1400 void ieee80211_txq_init(struct ieee80211_sub_if_data *sdata,
1401 			struct sta_info *sta,
1402 			struct txq_info *txqi, int tid)
1403 {
1404 	fq_tin_init(&txqi->tin);
1405 	fq_flow_init(&txqi->def_flow);
1406 	codel_vars_init(&txqi->def_cvars);
1407 
1408 	txqi->txq.vif = &sdata->vif;
1409 
1410 	if (sta) {
1411 		txqi->txq.sta = &sta->sta;
1412 		sta->sta.txq[tid] = &txqi->txq;
1413 		txqi->txq.tid = tid;
1414 		txqi->txq.ac = ieee802_1d_to_ac[tid & 7];
1415 	} else {
1416 		sdata->vif.txq = &txqi->txq;
1417 		txqi->txq.tid = 0;
1418 		txqi->txq.ac = IEEE80211_AC_BE;
1419 	}
1420 }
1421 
1422 void ieee80211_txq_purge(struct ieee80211_local *local,
1423 			 struct txq_info *txqi)
1424 {
1425 	struct fq *fq = &local->fq;
1426 	struct fq_tin *tin = &txqi->tin;
1427 
1428 	fq_tin_reset(fq, tin, fq_skb_free_func);
1429 }
1430 
1431 int ieee80211_txq_setup_flows(struct ieee80211_local *local)
1432 {
1433 	struct fq *fq = &local->fq;
1434 	int ret;
1435 	int i;
1436 
1437 	if (!local->ops->wake_tx_queue)
1438 		return 0;
1439 
1440 	ret = fq_init(fq, 4096);
1441 	if (ret)
1442 		return ret;
1443 
1444 	codel_params_init(&local->cparams);
1445 	codel_stats_init(&local->cstats);
1446 	local->cparams.interval = MS2TIME(100);
1447 	local->cparams.target = MS2TIME(20);
1448 	local->cparams.ecn = true;
1449 
1450 	local->cvars = kcalloc(fq->flows_cnt, sizeof(local->cvars[0]),
1451 			       GFP_KERNEL);
1452 	if (!local->cvars) {
1453 		spin_lock_bh(&fq->lock);
1454 		fq_reset(fq, fq_skb_free_func);
1455 		spin_unlock_bh(&fq->lock);
1456 		return -ENOMEM;
1457 	}
1458 
1459 	for (i = 0; i < fq->flows_cnt; i++)
1460 		codel_vars_init(&local->cvars[i]);
1461 
1462 	return 0;
1463 }
1464 
1465 void ieee80211_txq_teardown_flows(struct ieee80211_local *local)
1466 {
1467 	struct fq *fq = &local->fq;
1468 
1469 	if (!local->ops->wake_tx_queue)
1470 		return;
1471 
1472 	kfree(local->cvars);
1473 	local->cvars = NULL;
1474 
1475 	spin_lock_bh(&fq->lock);
1476 	fq_reset(fq, fq_skb_free_func);
1477 	spin_unlock_bh(&fq->lock);
1478 }
1479 
1480 struct sk_buff *ieee80211_tx_dequeue(struct ieee80211_hw *hw,
1481 				     struct ieee80211_txq *txq)
1482 {
1483 	struct ieee80211_local *local = hw_to_local(hw);
1484 	struct txq_info *txqi = container_of(txq, struct txq_info, txq);
1485 	struct ieee80211_hdr *hdr;
1486 	struct sk_buff *skb = NULL;
1487 	struct fq *fq = &local->fq;
1488 	struct fq_tin *tin = &txqi->tin;
1489 
1490 	spin_lock_bh(&fq->lock);
1491 
1492 	if (test_bit(IEEE80211_TXQ_STOP, &txqi->flags))
1493 		goto out;
1494 
1495 	skb = fq_tin_dequeue(fq, tin, fq_tin_dequeue_func);
1496 	if (!skb)
1497 		goto out;
1498 
1499 	ieee80211_set_skb_vif(skb, txqi);
1500 
1501 	hdr = (struct ieee80211_hdr *)skb->data;
1502 	if (txq->sta && ieee80211_is_data_qos(hdr->frame_control)) {
1503 		struct sta_info *sta = container_of(txq->sta, struct sta_info,
1504 						    sta);
1505 		struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
1506 
1507 		hdr->seq_ctrl = ieee80211_tx_next_seq(sta, txq->tid);
1508 		if (test_bit(IEEE80211_TXQ_AMPDU, &txqi->flags))
1509 			info->flags |= IEEE80211_TX_CTL_AMPDU;
1510 		else
1511 			info->flags &= ~IEEE80211_TX_CTL_AMPDU;
1512 	}
1513 
1514 out:
1515 	spin_unlock_bh(&fq->lock);
1516 
1517 	if (skb && skb_has_frag_list(skb) &&
1518 	    !ieee80211_hw_check(&local->hw, TX_FRAG_LIST)) {
1519 		if (skb_linearize(skb)) {
1520 			ieee80211_free_txskb(&local->hw, skb);
1521 			return NULL;
1522 		}
1523 	}
1524 
1525 	return skb;
1526 }
1527 EXPORT_SYMBOL(ieee80211_tx_dequeue);
1528 
1529 static bool ieee80211_tx_frags(struct ieee80211_local *local,
1530 			       struct ieee80211_vif *vif,
1531 			       struct ieee80211_sta *sta,
1532 			       struct sk_buff_head *skbs,
1533 			       bool txpending)
1534 {
1535 	struct ieee80211_tx_control control = {};
1536 	struct fq *fq = &local->fq;
1537 	struct sk_buff *skb, *tmp;
1538 	struct txq_info *txqi;
1539 	unsigned long flags;
1540 
1541 	skb_queue_walk_safe(skbs, skb, tmp) {
1542 		struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
1543 		int q = info->hw_queue;
1544 
1545 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG
1546 		if (WARN_ON_ONCE(q >= local->hw.queues)) {
1547 			__skb_unlink(skb, skbs);
1548 			ieee80211_free_txskb(&local->hw, skb);
1549 			continue;
1550 		}
1551 #endif
1552 
1553 		txqi = ieee80211_get_txq(local, vif, sta, skb);
1554 		if (txqi) {
1555 			info->control.vif = vif;
1556 
1557 			__skb_unlink(skb, skbs);
1558 
1559 			spin_lock_bh(&fq->lock);
1560 			ieee80211_txq_enqueue(local, txqi, skb);
1561 			spin_unlock_bh(&fq->lock);
1562 
1563 			drv_wake_tx_queue(local, txqi);
1564 
1565 			continue;
1566 		}
1567 
1568 		spin_lock_irqsave(&local->queue_stop_reason_lock, flags);
1569 		if (local->queue_stop_reasons[q] ||
1570 		    (!txpending && !skb_queue_empty(&local->pending[q]))) {
1571 			if (unlikely(info->flags &
1572 				     IEEE80211_TX_INTFL_OFFCHAN_TX_OK)) {
1573 				if (local->queue_stop_reasons[q] &
1574 				    ~BIT(IEEE80211_QUEUE_STOP_REASON_OFFCHANNEL)) {
1575 					/*
1576 					 * Drop off-channel frames if queues
1577 					 * are stopped for any reason other
1578 					 * than off-channel operation. Never
1579 					 * queue them.
1580 					 */
1581 					spin_unlock_irqrestore(
1582 						&local->queue_stop_reason_lock,
1583 						flags);
1584 					ieee80211_purge_tx_queue(&local->hw,
1585 								 skbs);
1586 					return true;
1587 				}
1588 			} else {
1589 
1590 				/*
1591 				 * Since queue is stopped, queue up frames for
1592 				 * later transmission from the tx-pending
1593 				 * tasklet when the queue is woken again.
1594 				 */
1595 				if (txpending)
1596 					skb_queue_splice_init(skbs,
1597 							      &local->pending[q]);
1598 				else
1599 					skb_queue_splice_tail_init(skbs,
1600 								   &local->pending[q]);
1601 
1602 				spin_unlock_irqrestore(&local->queue_stop_reason_lock,
1603 						       flags);
1604 				return false;
1605 			}
1606 		}
1607 		spin_unlock_irqrestore(&local->queue_stop_reason_lock, flags);
1608 
1609 		info->control.vif = vif;
1610 		control.sta = sta;
1611 
1612 		__skb_unlink(skb, skbs);
1613 		drv_tx(local, &control, skb);
1614 	}
1615 
1616 	return true;
1617 }
1618 
1619 /*
1620  * Returns false if the frame couldn't be transmitted but was queued instead.
1621  */
1622 static bool __ieee80211_tx(struct ieee80211_local *local,
1623 			   struct sk_buff_head *skbs, int led_len,
1624 			   struct sta_info *sta, bool txpending)
1625 {
1626 	struct ieee80211_tx_info *info;
1627 	struct ieee80211_sub_if_data *sdata;
1628 	struct ieee80211_vif *vif;
1629 	struct ieee80211_sta *pubsta;
1630 	struct sk_buff *skb;
1631 	bool result = true;
1632 	__le16 fc;
1633 
1634 	if (WARN_ON(skb_queue_empty(skbs)))
1635 		return true;
1636 
1637 	skb = skb_peek(skbs);
1638 	fc = ((struct ieee80211_hdr *)skb->data)->frame_control;
1639 	info = IEEE80211_SKB_CB(skb);
1640 	sdata = vif_to_sdata(info->control.vif);
1641 	if (sta && !sta->uploaded)
1642 		sta = NULL;
1643 
1644 	if (sta)
1645 		pubsta = &sta->sta;
1646 	else
1647 		pubsta = NULL;
1648 
1649 	switch (sdata->vif.type) {
1650 	case NL80211_IFTYPE_MONITOR:
1651 		if (sdata->u.mntr_flags & MONITOR_FLAG_ACTIVE) {
1652 			vif = &sdata->vif;
1653 			break;
1654 		}
1655 		sdata = rcu_dereference(local->monitor_sdata);
1656 		if (sdata) {
1657 			vif = &sdata->vif;
1658 			info->hw_queue =
1659 				vif->hw_queue[skb_get_queue_mapping(skb)];
1660 		} else if (ieee80211_hw_check(&local->hw, QUEUE_CONTROL)) {
1661 			ieee80211_purge_tx_queue(&local->hw, skbs);
1662 			return true;
1663 		} else
1664 			vif = NULL;
1665 		break;
1666 	case NL80211_IFTYPE_AP_VLAN:
1667 		sdata = container_of(sdata->bss,
1668 				     struct ieee80211_sub_if_data, u.ap);
1669 		/* fall through */
1670 	default:
1671 		vif = &sdata->vif;
1672 		break;
1673 	}
1674 
1675 	result = ieee80211_tx_frags(local, vif, pubsta, skbs,
1676 				    txpending);
1677 
1678 	ieee80211_tpt_led_trig_tx(local, fc, led_len);
1679 
1680 	WARN_ON_ONCE(!skb_queue_empty(skbs));
1681 
1682 	return result;
1683 }
1684 
1685 /*
1686  * Invoke TX handlers, return 0 on success and non-zero if the
1687  * frame was dropped or queued.
1688  */
1689 static int invoke_tx_handlers(struct ieee80211_tx_data *tx)
1690 {
1691 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(tx->skb);
1692 	ieee80211_tx_result res = TX_DROP;
1693 
1694 #define CALL_TXH(txh) \
1695 	do {				\
1696 		res = txh(tx);		\
1697 		if (res != TX_CONTINUE)	\
1698 			goto txh_done;	\
1699 	} while (0)
1700 
1701 	CALL_TXH(ieee80211_tx_h_dynamic_ps);
1702 	CALL_TXH(ieee80211_tx_h_check_assoc);
1703 	CALL_TXH(ieee80211_tx_h_ps_buf);
1704 	CALL_TXH(ieee80211_tx_h_check_control_port_protocol);
1705 	CALL_TXH(ieee80211_tx_h_select_key);
1706 	if (!ieee80211_hw_check(&tx->local->hw, HAS_RATE_CONTROL))
1707 		CALL_TXH(ieee80211_tx_h_rate_ctrl);
1708 
1709 	if (unlikely(info->flags & IEEE80211_TX_INTFL_RETRANSMISSION)) {
1710 		__skb_queue_tail(&tx->skbs, tx->skb);
1711 		tx->skb = NULL;
1712 		goto txh_done;
1713 	}
1714 
1715 	CALL_TXH(ieee80211_tx_h_michael_mic_add);
1716 	CALL_TXH(ieee80211_tx_h_sequence);
1717 	CALL_TXH(ieee80211_tx_h_fragment);
1718 	/* handlers after fragment must be aware of tx info fragmentation! */
1719 	CALL_TXH(ieee80211_tx_h_stats);
1720 	CALL_TXH(ieee80211_tx_h_encrypt);
1721 	if (!ieee80211_hw_check(&tx->local->hw, HAS_RATE_CONTROL))
1722 		CALL_TXH(ieee80211_tx_h_calculate_duration);
1723 #undef CALL_TXH
1724 
1725  txh_done:
1726 	if (unlikely(res == TX_DROP)) {
1727 		I802_DEBUG_INC(tx->local->tx_handlers_drop);
1728 		if (tx->skb)
1729 			ieee80211_free_txskb(&tx->local->hw, tx->skb);
1730 		else
1731 			ieee80211_purge_tx_queue(&tx->local->hw, &tx->skbs);
1732 		return -1;
1733 	} else if (unlikely(res == TX_QUEUED)) {
1734 		I802_DEBUG_INC(tx->local->tx_handlers_queued);
1735 		return -1;
1736 	}
1737 
1738 	return 0;
1739 }
1740 
1741 bool ieee80211_tx_prepare_skb(struct ieee80211_hw *hw,
1742 			      struct ieee80211_vif *vif, struct sk_buff *skb,
1743 			      int band, struct ieee80211_sta **sta)
1744 {
1745 	struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
1746 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
1747 	struct ieee80211_tx_data tx;
1748 	struct sk_buff *skb2;
1749 
1750 	if (ieee80211_tx_prepare(sdata, &tx, NULL, skb) == TX_DROP)
1751 		return false;
1752 
1753 	info->band = band;
1754 	info->control.vif = vif;
1755 	info->hw_queue = vif->hw_queue[skb_get_queue_mapping(skb)];
1756 
1757 	if (invoke_tx_handlers(&tx))
1758 		return false;
1759 
1760 	if (sta) {
1761 		if (tx.sta)
1762 			*sta = &tx.sta->sta;
1763 		else
1764 			*sta = NULL;
1765 	}
1766 
1767 	/* this function isn't suitable for fragmented data frames */
1768 	skb2 = __skb_dequeue(&tx.skbs);
1769 	if (WARN_ON(skb2 != skb || !skb_queue_empty(&tx.skbs))) {
1770 		ieee80211_free_txskb(hw, skb2);
1771 		ieee80211_purge_tx_queue(hw, &tx.skbs);
1772 		return false;
1773 	}
1774 
1775 	return true;
1776 }
1777 EXPORT_SYMBOL(ieee80211_tx_prepare_skb);
1778 
1779 /*
1780  * Returns false if the frame couldn't be transmitted but was queued instead.
1781  */
1782 static bool ieee80211_tx(struct ieee80211_sub_if_data *sdata,
1783 			 struct sta_info *sta, struct sk_buff *skb,
1784 			 bool txpending)
1785 {
1786 	struct ieee80211_local *local = sdata->local;
1787 	struct ieee80211_tx_data tx;
1788 	ieee80211_tx_result res_prepare;
1789 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
1790 	bool result = true;
1791 	int led_len;
1792 
1793 	if (unlikely(skb->len < 10)) {
1794 		dev_kfree_skb(skb);
1795 		return true;
1796 	}
1797 
1798 	/* initialises tx */
1799 	led_len = skb->len;
1800 	res_prepare = ieee80211_tx_prepare(sdata, &tx, sta, skb);
1801 
1802 	if (unlikely(res_prepare == TX_DROP)) {
1803 		ieee80211_free_txskb(&local->hw, skb);
1804 		return true;
1805 	} else if (unlikely(res_prepare == TX_QUEUED)) {
1806 		return true;
1807 	}
1808 
1809 	/* set up hw_queue value early */
1810 	if (!(info->flags & IEEE80211_TX_CTL_TX_OFFCHAN) ||
1811 	    !ieee80211_hw_check(&local->hw, QUEUE_CONTROL))
1812 		info->hw_queue =
1813 			sdata->vif.hw_queue[skb_get_queue_mapping(skb)];
1814 
1815 	if (!invoke_tx_handlers(&tx))
1816 		result = __ieee80211_tx(local, &tx.skbs, led_len,
1817 					tx.sta, txpending);
1818 
1819 	return result;
1820 }
1821 
1822 /* device xmit handlers */
1823 
1824 static int ieee80211_skb_resize(struct ieee80211_sub_if_data *sdata,
1825 				struct sk_buff *skb,
1826 				int head_need, bool may_encrypt)
1827 {
1828 	struct ieee80211_local *local = sdata->local;
1829 	int tail_need = 0;
1830 
1831 	if (may_encrypt && sdata->crypto_tx_tailroom_needed_cnt) {
1832 		tail_need = IEEE80211_ENCRYPT_TAILROOM;
1833 		tail_need -= skb_tailroom(skb);
1834 		tail_need = max_t(int, tail_need, 0);
1835 	}
1836 
1837 	if (skb_cloned(skb) &&
1838 	    (!ieee80211_hw_check(&local->hw, SUPPORTS_CLONED_SKBS) ||
1839 	     !skb_clone_writable(skb, ETH_HLEN) ||
1840 	     (may_encrypt && sdata->crypto_tx_tailroom_needed_cnt)))
1841 		I802_DEBUG_INC(local->tx_expand_skb_head_cloned);
1842 	else if (head_need || tail_need)
1843 		I802_DEBUG_INC(local->tx_expand_skb_head);
1844 	else
1845 		return 0;
1846 
1847 	if (pskb_expand_head(skb, head_need, tail_need, GFP_ATOMIC)) {
1848 		wiphy_debug(local->hw.wiphy,
1849 			    "failed to reallocate TX buffer\n");
1850 		return -ENOMEM;
1851 	}
1852 
1853 	return 0;
1854 }
1855 
1856 void ieee80211_xmit(struct ieee80211_sub_if_data *sdata,
1857 		    struct sta_info *sta, struct sk_buff *skb)
1858 {
1859 	struct ieee80211_local *local = sdata->local;
1860 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
1861 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
1862 	int headroom;
1863 	bool may_encrypt;
1864 
1865 	may_encrypt = !(info->flags & IEEE80211_TX_INTFL_DONT_ENCRYPT);
1866 
1867 	headroom = local->tx_headroom;
1868 	if (may_encrypt)
1869 		headroom += sdata->encrypt_headroom;
1870 	headroom -= skb_headroom(skb);
1871 	headroom = max_t(int, 0, headroom);
1872 
1873 	if (ieee80211_skb_resize(sdata, skb, headroom, may_encrypt)) {
1874 		ieee80211_free_txskb(&local->hw, skb);
1875 		return;
1876 	}
1877 
1878 	hdr = (struct ieee80211_hdr *) skb->data;
1879 	info->control.vif = &sdata->vif;
1880 
1881 	if (ieee80211_vif_is_mesh(&sdata->vif)) {
1882 		if (ieee80211_is_data(hdr->frame_control) &&
1883 		    is_unicast_ether_addr(hdr->addr1)) {
1884 			if (mesh_nexthop_resolve(sdata, skb))
1885 				return; /* skb queued: don't free */
1886 		} else {
1887 			ieee80211_mps_set_frame_flags(sdata, NULL, hdr);
1888 		}
1889 	}
1890 
1891 	ieee80211_set_qos_hdr(sdata, skb);
1892 	ieee80211_tx(sdata, sta, skb, false);
1893 }
1894 
1895 static bool ieee80211_parse_tx_radiotap(struct ieee80211_local *local,
1896 					struct sk_buff *skb)
1897 {
1898 	struct ieee80211_radiotap_iterator iterator;
1899 	struct ieee80211_radiotap_header *rthdr =
1900 		(struct ieee80211_radiotap_header *) skb->data;
1901 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
1902 	struct ieee80211_supported_band *sband =
1903 		local->hw.wiphy->bands[info->band];
1904 	int ret = ieee80211_radiotap_iterator_init(&iterator, rthdr, skb->len,
1905 						   NULL);
1906 	u16 txflags;
1907 	u16 rate = 0;
1908 	bool rate_found = false;
1909 	u8 rate_retries = 0;
1910 	u16 rate_flags = 0;
1911 	u8 mcs_known, mcs_flags, mcs_bw;
1912 	u16 vht_known;
1913 	u8 vht_mcs = 0, vht_nss = 0;
1914 	int i;
1915 
1916 	info->flags |= IEEE80211_TX_INTFL_DONT_ENCRYPT |
1917 		       IEEE80211_TX_CTL_DONTFRAG;
1918 
1919 	/*
1920 	 * for every radiotap entry that is present
1921 	 * (ieee80211_radiotap_iterator_next returns -ENOENT when no more
1922 	 * entries present, or -EINVAL on error)
1923 	 */
1924 
1925 	while (!ret) {
1926 		ret = ieee80211_radiotap_iterator_next(&iterator);
1927 
1928 		if (ret)
1929 			continue;
1930 
1931 		/* see if this argument is something we can use */
1932 		switch (iterator.this_arg_index) {
1933 		/*
1934 		 * You must take care when dereferencing iterator.this_arg
1935 		 * for multibyte types... the pointer is not aligned.  Use
1936 		 * get_unaligned((type *)iterator.this_arg) to dereference
1937 		 * iterator.this_arg for type "type" safely on all arches.
1938 		*/
1939 		case IEEE80211_RADIOTAP_FLAGS:
1940 			if (*iterator.this_arg & IEEE80211_RADIOTAP_F_FCS) {
1941 				/*
1942 				 * this indicates that the skb we have been
1943 				 * handed has the 32-bit FCS CRC at the end...
1944 				 * we should react to that by snipping it off
1945 				 * because it will be recomputed and added
1946 				 * on transmission
1947 				 */
1948 				if (skb->len < (iterator._max_length + FCS_LEN))
1949 					return false;
1950 
1951 				skb_trim(skb, skb->len - FCS_LEN);
1952 			}
1953 			if (*iterator.this_arg & IEEE80211_RADIOTAP_F_WEP)
1954 				info->flags &= ~IEEE80211_TX_INTFL_DONT_ENCRYPT;
1955 			if (*iterator.this_arg & IEEE80211_RADIOTAP_F_FRAG)
1956 				info->flags &= ~IEEE80211_TX_CTL_DONTFRAG;
1957 			break;
1958 
1959 		case IEEE80211_RADIOTAP_TX_FLAGS:
1960 			txflags = get_unaligned_le16(iterator.this_arg);
1961 			if (txflags & IEEE80211_RADIOTAP_F_TX_NOACK)
1962 				info->flags |= IEEE80211_TX_CTL_NO_ACK;
1963 			break;
1964 
1965 		case IEEE80211_RADIOTAP_RATE:
1966 			rate = *iterator.this_arg;
1967 			rate_flags = 0;
1968 			rate_found = true;
1969 			break;
1970 
1971 		case IEEE80211_RADIOTAP_DATA_RETRIES:
1972 			rate_retries = *iterator.this_arg;
1973 			break;
1974 
1975 		case IEEE80211_RADIOTAP_MCS:
1976 			mcs_known = iterator.this_arg[0];
1977 			mcs_flags = iterator.this_arg[1];
1978 			if (!(mcs_known & IEEE80211_RADIOTAP_MCS_HAVE_MCS))
1979 				break;
1980 
1981 			rate_found = true;
1982 			rate = iterator.this_arg[2];
1983 			rate_flags = IEEE80211_TX_RC_MCS;
1984 
1985 			if (mcs_known & IEEE80211_RADIOTAP_MCS_HAVE_GI &&
1986 			    mcs_flags & IEEE80211_RADIOTAP_MCS_SGI)
1987 				rate_flags |= IEEE80211_TX_RC_SHORT_GI;
1988 
1989 			mcs_bw = mcs_flags & IEEE80211_RADIOTAP_MCS_BW_MASK;
1990 			if (mcs_known & IEEE80211_RADIOTAP_MCS_HAVE_BW &&
1991 			    mcs_bw == IEEE80211_RADIOTAP_MCS_BW_40)
1992 				rate_flags |= IEEE80211_TX_RC_40_MHZ_WIDTH;
1993 			break;
1994 
1995 		case IEEE80211_RADIOTAP_VHT:
1996 			vht_known = get_unaligned_le16(iterator.this_arg);
1997 			rate_found = true;
1998 
1999 			rate_flags = IEEE80211_TX_RC_VHT_MCS;
2000 			if ((vht_known & IEEE80211_RADIOTAP_VHT_KNOWN_GI) &&
2001 			    (iterator.this_arg[2] &
2002 			     IEEE80211_RADIOTAP_VHT_FLAG_SGI))
2003 				rate_flags |= IEEE80211_TX_RC_SHORT_GI;
2004 			if (vht_known &
2005 			    IEEE80211_RADIOTAP_VHT_KNOWN_BANDWIDTH) {
2006 				if (iterator.this_arg[3] == 1)
2007 					rate_flags |=
2008 						IEEE80211_TX_RC_40_MHZ_WIDTH;
2009 				else if (iterator.this_arg[3] == 4)
2010 					rate_flags |=
2011 						IEEE80211_TX_RC_80_MHZ_WIDTH;
2012 				else if (iterator.this_arg[3] == 11)
2013 					rate_flags |=
2014 						IEEE80211_TX_RC_160_MHZ_WIDTH;
2015 			}
2016 
2017 			vht_mcs = iterator.this_arg[4] >> 4;
2018 			vht_nss = iterator.this_arg[4] & 0xF;
2019 			break;
2020 
2021 		/*
2022 		 * Please update the file
2023 		 * Documentation/networking/mac80211-injection.txt
2024 		 * when parsing new fields here.
2025 		 */
2026 
2027 		default:
2028 			break;
2029 		}
2030 	}
2031 
2032 	if (ret != -ENOENT) /* ie, if we didn't simply run out of fields */
2033 		return false;
2034 
2035 	if (rate_found) {
2036 		info->control.flags |= IEEE80211_TX_CTRL_RATE_INJECT;
2037 
2038 		for (i = 0; i < IEEE80211_TX_MAX_RATES; i++) {
2039 			info->control.rates[i].idx = -1;
2040 			info->control.rates[i].flags = 0;
2041 			info->control.rates[i].count = 0;
2042 		}
2043 
2044 		if (rate_flags & IEEE80211_TX_RC_MCS) {
2045 			info->control.rates[0].idx = rate;
2046 		} else if (rate_flags & IEEE80211_TX_RC_VHT_MCS) {
2047 			ieee80211_rate_set_vht(info->control.rates, vht_mcs,
2048 					       vht_nss);
2049 		} else {
2050 			for (i = 0; i < sband->n_bitrates; i++) {
2051 				if (rate * 5 != sband->bitrates[i].bitrate)
2052 					continue;
2053 
2054 				info->control.rates[0].idx = i;
2055 				break;
2056 			}
2057 		}
2058 
2059 		if (info->control.rates[0].idx < 0)
2060 			info->control.flags &= ~IEEE80211_TX_CTRL_RATE_INJECT;
2061 
2062 		info->control.rates[0].flags = rate_flags;
2063 		info->control.rates[0].count = min_t(u8, rate_retries + 1,
2064 						     local->hw.max_rate_tries);
2065 	}
2066 
2067 	/*
2068 	 * remove the radiotap header
2069 	 * iterator->_max_length was sanity-checked against
2070 	 * skb->len by iterator init
2071 	 */
2072 	skb_pull(skb, iterator._max_length);
2073 
2074 	return true;
2075 }
2076 
2077 netdev_tx_t ieee80211_monitor_start_xmit(struct sk_buff *skb,
2078 					 struct net_device *dev)
2079 {
2080 	struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
2081 	struct ieee80211_chanctx_conf *chanctx_conf;
2082 	struct ieee80211_radiotap_header *prthdr =
2083 		(struct ieee80211_radiotap_header *)skb->data;
2084 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
2085 	struct ieee80211_hdr *hdr;
2086 	struct ieee80211_sub_if_data *tmp_sdata, *sdata;
2087 	struct cfg80211_chan_def *chandef;
2088 	u16 len_rthdr;
2089 	int hdrlen;
2090 
2091 	/* check for not even having the fixed radiotap header part */
2092 	if (unlikely(skb->len < sizeof(struct ieee80211_radiotap_header)))
2093 		goto fail; /* too short to be possibly valid */
2094 
2095 	/* is it a header version we can trust to find length from? */
2096 	if (unlikely(prthdr->it_version))
2097 		goto fail; /* only version 0 is supported */
2098 
2099 	/* then there must be a radiotap header with a length we can use */
2100 	len_rthdr = ieee80211_get_radiotap_len(skb->data);
2101 
2102 	/* does the skb contain enough to deliver on the alleged length? */
2103 	if (unlikely(skb->len < len_rthdr))
2104 		goto fail; /* skb too short for claimed rt header extent */
2105 
2106 	/*
2107 	 * fix up the pointers accounting for the radiotap
2108 	 * header still being in there.  We are being given
2109 	 * a precooked IEEE80211 header so no need for
2110 	 * normal processing
2111 	 */
2112 	skb_set_mac_header(skb, len_rthdr);
2113 	/*
2114 	 * these are just fixed to the end of the rt area since we
2115 	 * don't have any better information and at this point, nobody cares
2116 	 */
2117 	skb_set_network_header(skb, len_rthdr);
2118 	skb_set_transport_header(skb, len_rthdr);
2119 
2120 	if (skb->len < len_rthdr + 2)
2121 		goto fail;
2122 
2123 	hdr = (struct ieee80211_hdr *)(skb->data + len_rthdr);
2124 	hdrlen = ieee80211_hdrlen(hdr->frame_control);
2125 
2126 	if (skb->len < len_rthdr + hdrlen)
2127 		goto fail;
2128 
2129 	/*
2130 	 * Initialize skb->protocol if the injected frame is a data frame
2131 	 * carrying a rfc1042 header
2132 	 */
2133 	if (ieee80211_is_data(hdr->frame_control) &&
2134 	    skb->len >= len_rthdr + hdrlen + sizeof(rfc1042_header) + 2) {
2135 		u8 *payload = (u8 *)hdr + hdrlen;
2136 
2137 		if (ether_addr_equal(payload, rfc1042_header))
2138 			skb->protocol = cpu_to_be16((payload[6] << 8) |
2139 						    payload[7]);
2140 	}
2141 
2142 	memset(info, 0, sizeof(*info));
2143 
2144 	info->flags = IEEE80211_TX_CTL_REQ_TX_STATUS |
2145 		      IEEE80211_TX_CTL_INJECTED;
2146 
2147 	rcu_read_lock();
2148 
2149 	/*
2150 	 * We process outgoing injected frames that have a local address
2151 	 * we handle as though they are non-injected frames.
2152 	 * This code here isn't entirely correct, the local MAC address
2153 	 * isn't always enough to find the interface to use; for proper
2154 	 * VLAN/WDS support we will need a different mechanism (which
2155 	 * likely isn't going to be monitor interfaces).
2156 	 */
2157 	sdata = IEEE80211_DEV_TO_SUB_IF(dev);
2158 
2159 	list_for_each_entry_rcu(tmp_sdata, &local->interfaces, list) {
2160 		if (!ieee80211_sdata_running(tmp_sdata))
2161 			continue;
2162 		if (tmp_sdata->vif.type == NL80211_IFTYPE_MONITOR ||
2163 		    tmp_sdata->vif.type == NL80211_IFTYPE_AP_VLAN ||
2164 		    tmp_sdata->vif.type == NL80211_IFTYPE_WDS)
2165 			continue;
2166 		if (ether_addr_equal(tmp_sdata->vif.addr, hdr->addr2)) {
2167 			sdata = tmp_sdata;
2168 			break;
2169 		}
2170 	}
2171 
2172 	chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);
2173 	if (!chanctx_conf) {
2174 		tmp_sdata = rcu_dereference(local->monitor_sdata);
2175 		if (tmp_sdata)
2176 			chanctx_conf =
2177 				rcu_dereference(tmp_sdata->vif.chanctx_conf);
2178 	}
2179 
2180 	if (chanctx_conf)
2181 		chandef = &chanctx_conf->def;
2182 	else if (!local->use_chanctx)
2183 		chandef = &local->_oper_chandef;
2184 	else
2185 		goto fail_rcu;
2186 
2187 	/*
2188 	 * Frame injection is not allowed if beaconing is not allowed
2189 	 * or if we need radar detection. Beaconing is usually not allowed when
2190 	 * the mode or operation (Adhoc, AP, Mesh) does not support DFS.
2191 	 * Passive scan is also used in world regulatory domains where
2192 	 * your country is not known and as such it should be treated as
2193 	 * NO TX unless the channel is explicitly allowed in which case
2194 	 * your current regulatory domain would not have the passive scan
2195 	 * flag.
2196 	 *
2197 	 * Since AP mode uses monitor interfaces to inject/TX management
2198 	 * frames we can make AP mode the exception to this rule once it
2199 	 * supports radar detection as its implementation can deal with
2200 	 * radar detection by itself. We can do that later by adding a
2201 	 * monitor flag interfaces used for AP support.
2202 	 */
2203 	if (!cfg80211_reg_can_beacon(local->hw.wiphy, chandef,
2204 				     sdata->vif.type))
2205 		goto fail_rcu;
2206 
2207 	info->band = chandef->chan->band;
2208 
2209 	/* process and remove the injection radiotap header */
2210 	if (!ieee80211_parse_tx_radiotap(local, skb))
2211 		goto fail_rcu;
2212 
2213 	ieee80211_xmit(sdata, NULL, skb);
2214 	rcu_read_unlock();
2215 
2216 	return NETDEV_TX_OK;
2217 
2218 fail_rcu:
2219 	rcu_read_unlock();
2220 fail:
2221 	dev_kfree_skb(skb);
2222 	return NETDEV_TX_OK; /* meaning, we dealt with the skb */
2223 }
2224 
2225 static inline bool ieee80211_is_tdls_setup(struct sk_buff *skb)
2226 {
2227 	u16 ethertype = (skb->data[12] << 8) | skb->data[13];
2228 
2229 	return ethertype == ETH_P_TDLS &&
2230 	       skb->len > 14 &&
2231 	       skb->data[14] == WLAN_TDLS_SNAP_RFTYPE;
2232 }
2233 
2234 static int ieee80211_lookup_ra_sta(struct ieee80211_sub_if_data *sdata,
2235 				   struct sk_buff *skb,
2236 				   struct sta_info **sta_out)
2237 {
2238 	struct sta_info *sta;
2239 
2240 	switch (sdata->vif.type) {
2241 	case NL80211_IFTYPE_AP_VLAN:
2242 		sta = rcu_dereference(sdata->u.vlan.sta);
2243 		if (sta) {
2244 			*sta_out = sta;
2245 			return 0;
2246 		} else if (sdata->wdev.use_4addr) {
2247 			return -ENOLINK;
2248 		}
2249 		/* fall through */
2250 	case NL80211_IFTYPE_AP:
2251 	case NL80211_IFTYPE_OCB:
2252 	case NL80211_IFTYPE_ADHOC:
2253 		if (is_multicast_ether_addr(skb->data)) {
2254 			*sta_out = ERR_PTR(-ENOENT);
2255 			return 0;
2256 		}
2257 		sta = sta_info_get_bss(sdata, skb->data);
2258 		break;
2259 	case NL80211_IFTYPE_WDS:
2260 		sta = sta_info_get(sdata, sdata->u.wds.remote_addr);
2261 		break;
2262 #ifdef CONFIG_MAC80211_MESH
2263 	case NL80211_IFTYPE_MESH_POINT:
2264 		/* determined much later */
2265 		*sta_out = NULL;
2266 		return 0;
2267 #endif
2268 	case NL80211_IFTYPE_STATION:
2269 		if (sdata->wdev.wiphy->flags & WIPHY_FLAG_SUPPORTS_TDLS) {
2270 			sta = sta_info_get(sdata, skb->data);
2271 			if (sta) {
2272 				bool tdls_peer, tdls_auth;
2273 
2274 				tdls_peer = test_sta_flag(sta,
2275 							  WLAN_STA_TDLS_PEER);
2276 				tdls_auth = test_sta_flag(sta,
2277 						WLAN_STA_TDLS_PEER_AUTH);
2278 
2279 				if (tdls_peer && tdls_auth) {
2280 					*sta_out = sta;
2281 					return 0;
2282 				}
2283 
2284 				/*
2285 				 * TDLS link during setup - throw out frames to
2286 				 * peer. Allow TDLS-setup frames to unauthorized
2287 				 * peers for the special case of a link teardown
2288 				 * after a TDLS sta is removed due to being
2289 				 * unreachable.
2290 				 */
2291 				if (tdls_peer && !tdls_auth &&
2292 				    !ieee80211_is_tdls_setup(skb))
2293 					return -EINVAL;
2294 			}
2295 
2296 		}
2297 
2298 		sta = sta_info_get(sdata, sdata->u.mgd.bssid);
2299 		if (!sta)
2300 			return -ENOLINK;
2301 		break;
2302 	default:
2303 		return -EINVAL;
2304 	}
2305 
2306 	*sta_out = sta ?: ERR_PTR(-ENOENT);
2307 	return 0;
2308 }
2309 
2310 /**
2311  * ieee80211_build_hdr - build 802.11 header in the given frame
2312  * @sdata: virtual interface to build the header for
2313  * @skb: the skb to build the header in
2314  * @info_flags: skb flags to set
2315  *
2316  * This function takes the skb with 802.3 header and reformats the header to
2317  * the appropriate IEEE 802.11 header based on which interface the packet is
2318  * being transmitted on.
2319  *
2320  * Note that this function also takes care of the TX status request and
2321  * potential unsharing of the SKB - this needs to be interleaved with the
2322  * header building.
2323  *
2324  * The function requires the read-side RCU lock held
2325  *
2326  * Returns: the (possibly reallocated) skb or an ERR_PTR() code
2327  */
2328 static struct sk_buff *ieee80211_build_hdr(struct ieee80211_sub_if_data *sdata,
2329 					   struct sk_buff *skb, u32 info_flags,
2330 					   struct sta_info *sta)
2331 {
2332 	struct ieee80211_local *local = sdata->local;
2333 	struct ieee80211_tx_info *info;
2334 	int head_need;
2335 	u16 ethertype, hdrlen,  meshhdrlen = 0;
2336 	__le16 fc;
2337 	struct ieee80211_hdr hdr;
2338 	struct ieee80211s_hdr mesh_hdr __maybe_unused;
2339 	struct mesh_path __maybe_unused *mppath = NULL, *mpath = NULL;
2340 	const u8 *encaps_data;
2341 	int encaps_len, skip_header_bytes;
2342 	int nh_pos, h_pos;
2343 	bool wme_sta = false, authorized = false;
2344 	bool tdls_peer;
2345 	bool multicast;
2346 	u16 info_id = 0;
2347 	struct ieee80211_chanctx_conf *chanctx_conf;
2348 	struct ieee80211_sub_if_data *ap_sdata;
2349 	enum nl80211_band band;
2350 	int ret;
2351 
2352 	if (IS_ERR(sta))
2353 		sta = NULL;
2354 
2355 	/* convert Ethernet header to proper 802.11 header (based on
2356 	 * operation mode) */
2357 	ethertype = (skb->data[12] << 8) | skb->data[13];
2358 	fc = cpu_to_le16(IEEE80211_FTYPE_DATA | IEEE80211_STYPE_DATA);
2359 
2360 	switch (sdata->vif.type) {
2361 	case NL80211_IFTYPE_AP_VLAN:
2362 		if (sdata->wdev.use_4addr) {
2363 			fc |= cpu_to_le16(IEEE80211_FCTL_FROMDS | IEEE80211_FCTL_TODS);
2364 			/* RA TA DA SA */
2365 			memcpy(hdr.addr1, sta->sta.addr, ETH_ALEN);
2366 			memcpy(hdr.addr2, sdata->vif.addr, ETH_ALEN);
2367 			memcpy(hdr.addr3, skb->data, ETH_ALEN);
2368 			memcpy(hdr.addr4, skb->data + ETH_ALEN, ETH_ALEN);
2369 			hdrlen = 30;
2370 			authorized = test_sta_flag(sta, WLAN_STA_AUTHORIZED);
2371 			wme_sta = sta->sta.wme;
2372 		}
2373 		ap_sdata = container_of(sdata->bss, struct ieee80211_sub_if_data,
2374 					u.ap);
2375 		chanctx_conf = rcu_dereference(ap_sdata->vif.chanctx_conf);
2376 		if (!chanctx_conf) {
2377 			ret = -ENOTCONN;
2378 			goto free;
2379 		}
2380 		band = chanctx_conf->def.chan->band;
2381 		if (sdata->wdev.use_4addr)
2382 			break;
2383 		/* fall through */
2384 	case NL80211_IFTYPE_AP:
2385 		if (sdata->vif.type == NL80211_IFTYPE_AP)
2386 			chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);
2387 		if (!chanctx_conf) {
2388 			ret = -ENOTCONN;
2389 			goto free;
2390 		}
2391 		fc |= cpu_to_le16(IEEE80211_FCTL_FROMDS);
2392 		/* DA BSSID SA */
2393 		memcpy(hdr.addr1, skb->data, ETH_ALEN);
2394 		memcpy(hdr.addr2, sdata->vif.addr, ETH_ALEN);
2395 		memcpy(hdr.addr3, skb->data + ETH_ALEN, ETH_ALEN);
2396 		hdrlen = 24;
2397 		band = chanctx_conf->def.chan->band;
2398 		break;
2399 	case NL80211_IFTYPE_WDS:
2400 		fc |= cpu_to_le16(IEEE80211_FCTL_FROMDS | IEEE80211_FCTL_TODS);
2401 		/* RA TA DA SA */
2402 		memcpy(hdr.addr1, sdata->u.wds.remote_addr, ETH_ALEN);
2403 		memcpy(hdr.addr2, sdata->vif.addr, ETH_ALEN);
2404 		memcpy(hdr.addr3, skb->data, ETH_ALEN);
2405 		memcpy(hdr.addr4, skb->data + ETH_ALEN, ETH_ALEN);
2406 		hdrlen = 30;
2407 		/*
2408 		 * This is the exception! WDS style interfaces are prohibited
2409 		 * when channel contexts are in used so this must be valid
2410 		 */
2411 		band = local->hw.conf.chandef.chan->band;
2412 		break;
2413 #ifdef CONFIG_MAC80211_MESH
2414 	case NL80211_IFTYPE_MESH_POINT:
2415 		if (!is_multicast_ether_addr(skb->data)) {
2416 			struct sta_info *next_hop;
2417 			bool mpp_lookup = true;
2418 
2419 			mpath = mesh_path_lookup(sdata, skb->data);
2420 			if (mpath) {
2421 				mpp_lookup = false;
2422 				next_hop = rcu_dereference(mpath->next_hop);
2423 				if (!next_hop ||
2424 				    !(mpath->flags & (MESH_PATH_ACTIVE |
2425 						      MESH_PATH_RESOLVING)))
2426 					mpp_lookup = true;
2427 			}
2428 
2429 			if (mpp_lookup) {
2430 				mppath = mpp_path_lookup(sdata, skb->data);
2431 				if (mppath)
2432 					mppath->exp_time = jiffies;
2433 			}
2434 
2435 			if (mppath && mpath)
2436 				mesh_path_del(sdata, mpath->dst);
2437 		}
2438 
2439 		/*
2440 		 * Use address extension if it is a packet from
2441 		 * another interface or if we know the destination
2442 		 * is being proxied by a portal (i.e. portal address
2443 		 * differs from proxied address)
2444 		 */
2445 		if (ether_addr_equal(sdata->vif.addr, skb->data + ETH_ALEN) &&
2446 		    !(mppath && !ether_addr_equal(mppath->mpp, skb->data))) {
2447 			hdrlen = ieee80211_fill_mesh_addresses(&hdr, &fc,
2448 					skb->data, skb->data + ETH_ALEN);
2449 			meshhdrlen = ieee80211_new_mesh_header(sdata, &mesh_hdr,
2450 							       NULL, NULL);
2451 		} else {
2452 			/* DS -> MBSS (802.11-2012 13.11.3.3).
2453 			 * For unicast with unknown forwarding information,
2454 			 * destination might be in the MBSS or if that fails
2455 			 * forwarded to another mesh gate. In either case
2456 			 * resolution will be handled in ieee80211_xmit(), so
2457 			 * leave the original DA. This also works for mcast */
2458 			const u8 *mesh_da = skb->data;
2459 
2460 			if (mppath)
2461 				mesh_da = mppath->mpp;
2462 			else if (mpath)
2463 				mesh_da = mpath->dst;
2464 
2465 			hdrlen = ieee80211_fill_mesh_addresses(&hdr, &fc,
2466 					mesh_da, sdata->vif.addr);
2467 			if (is_multicast_ether_addr(mesh_da))
2468 				/* DA TA mSA AE:SA */
2469 				meshhdrlen = ieee80211_new_mesh_header(
2470 						sdata, &mesh_hdr,
2471 						skb->data + ETH_ALEN, NULL);
2472 			else
2473 				/* RA TA mDA mSA AE:DA SA */
2474 				meshhdrlen = ieee80211_new_mesh_header(
2475 						sdata, &mesh_hdr, skb->data,
2476 						skb->data + ETH_ALEN);
2477 
2478 		}
2479 		chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);
2480 		if (!chanctx_conf) {
2481 			ret = -ENOTCONN;
2482 			goto free;
2483 		}
2484 		band = chanctx_conf->def.chan->band;
2485 		break;
2486 #endif
2487 	case NL80211_IFTYPE_STATION:
2488 		/* we already did checks when looking up the RA STA */
2489 		tdls_peer = test_sta_flag(sta, WLAN_STA_TDLS_PEER);
2490 
2491 		if (tdls_peer) {
2492 			/* DA SA BSSID */
2493 			memcpy(hdr.addr1, skb->data, ETH_ALEN);
2494 			memcpy(hdr.addr2, skb->data + ETH_ALEN, ETH_ALEN);
2495 			memcpy(hdr.addr3, sdata->u.mgd.bssid, ETH_ALEN);
2496 			hdrlen = 24;
2497 		}  else if (sdata->u.mgd.use_4addr &&
2498 			    cpu_to_be16(ethertype) != sdata->control_port_protocol) {
2499 			fc |= cpu_to_le16(IEEE80211_FCTL_FROMDS |
2500 					  IEEE80211_FCTL_TODS);
2501 			/* RA TA DA SA */
2502 			memcpy(hdr.addr1, sdata->u.mgd.bssid, ETH_ALEN);
2503 			memcpy(hdr.addr2, sdata->vif.addr, ETH_ALEN);
2504 			memcpy(hdr.addr3, skb->data, ETH_ALEN);
2505 			memcpy(hdr.addr4, skb->data + ETH_ALEN, ETH_ALEN);
2506 			hdrlen = 30;
2507 		} else {
2508 			fc |= cpu_to_le16(IEEE80211_FCTL_TODS);
2509 			/* BSSID SA DA */
2510 			memcpy(hdr.addr1, sdata->u.mgd.bssid, ETH_ALEN);
2511 			memcpy(hdr.addr2, skb->data + ETH_ALEN, ETH_ALEN);
2512 			memcpy(hdr.addr3, skb->data, ETH_ALEN);
2513 			hdrlen = 24;
2514 		}
2515 		chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);
2516 		if (!chanctx_conf) {
2517 			ret = -ENOTCONN;
2518 			goto free;
2519 		}
2520 		band = chanctx_conf->def.chan->band;
2521 		break;
2522 	case NL80211_IFTYPE_OCB:
2523 		/* DA SA BSSID */
2524 		memcpy(hdr.addr1, skb->data, ETH_ALEN);
2525 		memcpy(hdr.addr2, skb->data + ETH_ALEN, ETH_ALEN);
2526 		eth_broadcast_addr(hdr.addr3);
2527 		hdrlen = 24;
2528 		chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);
2529 		if (!chanctx_conf) {
2530 			ret = -ENOTCONN;
2531 			goto free;
2532 		}
2533 		band = chanctx_conf->def.chan->band;
2534 		break;
2535 	case NL80211_IFTYPE_ADHOC:
2536 		/* DA SA BSSID */
2537 		memcpy(hdr.addr1, skb->data, ETH_ALEN);
2538 		memcpy(hdr.addr2, skb->data + ETH_ALEN, ETH_ALEN);
2539 		memcpy(hdr.addr3, sdata->u.ibss.bssid, ETH_ALEN);
2540 		hdrlen = 24;
2541 		chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);
2542 		if (!chanctx_conf) {
2543 			ret = -ENOTCONN;
2544 			goto free;
2545 		}
2546 		band = chanctx_conf->def.chan->band;
2547 		break;
2548 	default:
2549 		ret = -EINVAL;
2550 		goto free;
2551 	}
2552 
2553 	multicast = is_multicast_ether_addr(hdr.addr1);
2554 
2555 	/* sta is always NULL for mesh */
2556 	if (sta) {
2557 		authorized = test_sta_flag(sta, WLAN_STA_AUTHORIZED);
2558 		wme_sta = sta->sta.wme;
2559 	} else if (ieee80211_vif_is_mesh(&sdata->vif)) {
2560 		/* For mesh, the use of the QoS header is mandatory */
2561 		wme_sta = true;
2562 	}
2563 
2564 	/* receiver does QoS (which also means we do) use it */
2565 	if (wme_sta) {
2566 		fc |= cpu_to_le16(IEEE80211_STYPE_QOS_DATA);
2567 		hdrlen += 2;
2568 	}
2569 
2570 	/*
2571 	 * Drop unicast frames to unauthorised stations unless they are
2572 	 * EAPOL frames from the local station.
2573 	 */
2574 	if (unlikely(!ieee80211_vif_is_mesh(&sdata->vif) &&
2575 		     (sdata->vif.type != NL80211_IFTYPE_OCB) &&
2576 		     !multicast && !authorized &&
2577 		     (cpu_to_be16(ethertype) != sdata->control_port_protocol ||
2578 		      !ether_addr_equal(sdata->vif.addr, skb->data + ETH_ALEN)))) {
2579 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG
2580 		net_info_ratelimited("%s: dropped frame to %pM (unauthorized port)\n",
2581 				    sdata->name, hdr.addr1);
2582 #endif
2583 
2584 		I802_DEBUG_INC(local->tx_handlers_drop_unauth_port);
2585 
2586 		ret = -EPERM;
2587 		goto free;
2588 	}
2589 
2590 	if (unlikely(!multicast && skb->sk &&
2591 		     skb_shinfo(skb)->tx_flags & SKBTX_WIFI_STATUS)) {
2592 		struct sk_buff *ack_skb = skb_clone_sk(skb);
2593 
2594 		if (ack_skb) {
2595 			unsigned long flags;
2596 			int id;
2597 
2598 			spin_lock_irqsave(&local->ack_status_lock, flags);
2599 			id = idr_alloc(&local->ack_status_frames, ack_skb,
2600 				       1, 0x10000, GFP_ATOMIC);
2601 			spin_unlock_irqrestore(&local->ack_status_lock, flags);
2602 
2603 			if (id >= 0) {
2604 				info_id = id;
2605 				info_flags |= IEEE80211_TX_CTL_REQ_TX_STATUS;
2606 			} else {
2607 				kfree_skb(ack_skb);
2608 			}
2609 		}
2610 	}
2611 
2612 	/*
2613 	 * If the skb is shared we need to obtain our own copy.
2614 	 */
2615 	if (skb_shared(skb)) {
2616 		struct sk_buff *tmp_skb = skb;
2617 
2618 		/* can't happen -- skb is a clone if info_id != 0 */
2619 		WARN_ON(info_id);
2620 
2621 		skb = skb_clone(skb, GFP_ATOMIC);
2622 		kfree_skb(tmp_skb);
2623 
2624 		if (!skb) {
2625 			ret = -ENOMEM;
2626 			goto free;
2627 		}
2628 	}
2629 
2630 	hdr.frame_control = fc;
2631 	hdr.duration_id = 0;
2632 	hdr.seq_ctrl = 0;
2633 
2634 	skip_header_bytes = ETH_HLEN;
2635 	if (ethertype == ETH_P_AARP || ethertype == ETH_P_IPX) {
2636 		encaps_data = bridge_tunnel_header;
2637 		encaps_len = sizeof(bridge_tunnel_header);
2638 		skip_header_bytes -= 2;
2639 	} else if (ethertype >= ETH_P_802_3_MIN) {
2640 		encaps_data = rfc1042_header;
2641 		encaps_len = sizeof(rfc1042_header);
2642 		skip_header_bytes -= 2;
2643 	} else {
2644 		encaps_data = NULL;
2645 		encaps_len = 0;
2646 	}
2647 
2648 	nh_pos = skb_network_header(skb) - skb->data;
2649 	h_pos = skb_transport_header(skb) - skb->data;
2650 
2651 	skb_pull(skb, skip_header_bytes);
2652 	nh_pos -= skip_header_bytes;
2653 	h_pos -= skip_header_bytes;
2654 
2655 	head_need = hdrlen + encaps_len + meshhdrlen - skb_headroom(skb);
2656 
2657 	/*
2658 	 * So we need to modify the skb header and hence need a copy of
2659 	 * that. The head_need variable above doesn't, so far, include
2660 	 * the needed header space that we don't need right away. If we
2661 	 * can, then we don't reallocate right now but only after the
2662 	 * frame arrives at the master device (if it does...)
2663 	 *
2664 	 * If we cannot, however, then we will reallocate to include all
2665 	 * the ever needed space. Also, if we need to reallocate it anyway,
2666 	 * make it big enough for everything we may ever need.
2667 	 */
2668 
2669 	if (head_need > 0 || skb_cloned(skb)) {
2670 		head_need += sdata->encrypt_headroom;
2671 		head_need += local->tx_headroom;
2672 		head_need = max_t(int, 0, head_need);
2673 		if (ieee80211_skb_resize(sdata, skb, head_need, true)) {
2674 			ieee80211_free_txskb(&local->hw, skb);
2675 			skb = NULL;
2676 			return ERR_PTR(-ENOMEM);
2677 		}
2678 	}
2679 
2680 	if (encaps_data) {
2681 		memcpy(skb_push(skb, encaps_len), encaps_data, encaps_len);
2682 		nh_pos += encaps_len;
2683 		h_pos += encaps_len;
2684 	}
2685 
2686 #ifdef CONFIG_MAC80211_MESH
2687 	if (meshhdrlen > 0) {
2688 		memcpy(skb_push(skb, meshhdrlen), &mesh_hdr, meshhdrlen);
2689 		nh_pos += meshhdrlen;
2690 		h_pos += meshhdrlen;
2691 	}
2692 #endif
2693 
2694 	if (ieee80211_is_data_qos(fc)) {
2695 		__le16 *qos_control;
2696 
2697 		qos_control = (__le16 *) skb_push(skb, 2);
2698 		memcpy(skb_push(skb, hdrlen - 2), &hdr, hdrlen - 2);
2699 		/*
2700 		 * Maybe we could actually set some fields here, for now just
2701 		 * initialise to zero to indicate no special operation.
2702 		 */
2703 		*qos_control = 0;
2704 	} else
2705 		memcpy(skb_push(skb, hdrlen), &hdr, hdrlen);
2706 
2707 	nh_pos += hdrlen;
2708 	h_pos += hdrlen;
2709 
2710 	/* Update skb pointers to various headers since this modified frame
2711 	 * is going to go through Linux networking code that may potentially
2712 	 * need things like pointer to IP header. */
2713 	skb_reset_mac_header(skb);
2714 	skb_set_network_header(skb, nh_pos);
2715 	skb_set_transport_header(skb, h_pos);
2716 
2717 	info = IEEE80211_SKB_CB(skb);
2718 	memset(info, 0, sizeof(*info));
2719 
2720 	info->flags = info_flags;
2721 	info->ack_frame_id = info_id;
2722 	info->band = band;
2723 
2724 	return skb;
2725  free:
2726 	kfree_skb(skb);
2727 	return ERR_PTR(ret);
2728 }
2729 
2730 /*
2731  * fast-xmit overview
2732  *
2733  * The core idea of this fast-xmit is to remove per-packet checks by checking
2734  * them out of band. ieee80211_check_fast_xmit() implements the out-of-band
2735  * checks that are needed to get the sta->fast_tx pointer assigned, after which
2736  * much less work can be done per packet. For example, fragmentation must be
2737  * disabled or the fast_tx pointer will not be set. All the conditions are seen
2738  * in the code here.
2739  *
2740  * Once assigned, the fast_tx data structure also caches the per-packet 802.11
2741  * header and other data to aid packet processing in ieee80211_xmit_fast().
2742  *
2743  * The most difficult part of this is that when any of these assumptions
2744  * change, an external trigger (i.e. a call to ieee80211_clear_fast_xmit(),
2745  * ieee80211_check_fast_xmit() or friends) is required to reset the data,
2746  * since the per-packet code no longer checks the conditions. This is reflected
2747  * by the calls to these functions throughout the rest of the code, and must be
2748  * maintained if any of the TX path checks change.
2749  */
2750 
2751 void ieee80211_check_fast_xmit(struct sta_info *sta)
2752 {
2753 	struct ieee80211_fast_tx build = {}, *fast_tx = NULL, *old;
2754 	struct ieee80211_local *local = sta->local;
2755 	struct ieee80211_sub_if_data *sdata = sta->sdata;
2756 	struct ieee80211_hdr *hdr = (void *)build.hdr;
2757 	struct ieee80211_chanctx_conf *chanctx_conf;
2758 	__le16 fc;
2759 
2760 	if (!ieee80211_hw_check(&local->hw, SUPPORT_FAST_XMIT))
2761 		return;
2762 
2763 	/* Locking here protects both the pointer itself, and against concurrent
2764 	 * invocations winning data access races to, e.g., the key pointer that
2765 	 * is used.
2766 	 * Without it, the invocation of this function right after the key
2767 	 * pointer changes wouldn't be sufficient, as another CPU could access
2768 	 * the pointer, then stall, and then do the cache update after the CPU
2769 	 * that invalidated the key.
2770 	 * With the locking, such scenarios cannot happen as the check for the
2771 	 * key and the fast-tx assignment are done atomically, so the CPU that
2772 	 * modifies the key will either wait or other one will see the key
2773 	 * cleared/changed already.
2774 	 */
2775 	spin_lock_bh(&sta->lock);
2776 	if (ieee80211_hw_check(&local->hw, SUPPORTS_PS) &&
2777 	    !ieee80211_hw_check(&local->hw, SUPPORTS_DYNAMIC_PS) &&
2778 	    sdata->vif.type == NL80211_IFTYPE_STATION)
2779 		goto out;
2780 
2781 	if (!test_sta_flag(sta, WLAN_STA_AUTHORIZED))
2782 		goto out;
2783 
2784 	if (test_sta_flag(sta, WLAN_STA_PS_STA) ||
2785 	    test_sta_flag(sta, WLAN_STA_PS_DRIVER) ||
2786 	    test_sta_flag(sta, WLAN_STA_PS_DELIVER) ||
2787 	    test_sta_flag(sta, WLAN_STA_CLEAR_PS_FILT))
2788 		goto out;
2789 
2790 	if (sdata->noack_map)
2791 		goto out;
2792 
2793 	/* fast-xmit doesn't handle fragmentation at all */
2794 	if (local->hw.wiphy->frag_threshold != (u32)-1 &&
2795 	    !local->ops->set_frag_threshold)
2796 		goto out;
2797 
2798 	rcu_read_lock();
2799 	chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);
2800 	if (!chanctx_conf) {
2801 		rcu_read_unlock();
2802 		goto out;
2803 	}
2804 	build.band = chanctx_conf->def.chan->band;
2805 	rcu_read_unlock();
2806 
2807 	fc = cpu_to_le16(IEEE80211_FTYPE_DATA | IEEE80211_STYPE_DATA);
2808 
2809 	switch (sdata->vif.type) {
2810 	case NL80211_IFTYPE_ADHOC:
2811 		/* DA SA BSSID */
2812 		build.da_offs = offsetof(struct ieee80211_hdr, addr1);
2813 		build.sa_offs = offsetof(struct ieee80211_hdr, addr2);
2814 		memcpy(hdr->addr3, sdata->u.ibss.bssid, ETH_ALEN);
2815 		build.hdr_len = 24;
2816 		break;
2817 	case NL80211_IFTYPE_STATION:
2818 		if (test_sta_flag(sta, WLAN_STA_TDLS_PEER)) {
2819 			/* DA SA BSSID */
2820 			build.da_offs = offsetof(struct ieee80211_hdr, addr1);
2821 			build.sa_offs = offsetof(struct ieee80211_hdr, addr2);
2822 			memcpy(hdr->addr3, sdata->u.mgd.bssid, ETH_ALEN);
2823 			build.hdr_len = 24;
2824 			break;
2825 		}
2826 
2827 		if (sdata->u.mgd.use_4addr) {
2828 			/* non-regular ethertype cannot use the fastpath */
2829 			fc |= cpu_to_le16(IEEE80211_FCTL_FROMDS |
2830 					  IEEE80211_FCTL_TODS);
2831 			/* RA TA DA SA */
2832 			memcpy(hdr->addr1, sdata->u.mgd.bssid, ETH_ALEN);
2833 			memcpy(hdr->addr2, sdata->vif.addr, ETH_ALEN);
2834 			build.da_offs = offsetof(struct ieee80211_hdr, addr3);
2835 			build.sa_offs = offsetof(struct ieee80211_hdr, addr4);
2836 			build.hdr_len = 30;
2837 			break;
2838 		}
2839 		fc |= cpu_to_le16(IEEE80211_FCTL_TODS);
2840 		/* BSSID SA DA */
2841 		memcpy(hdr->addr1, sdata->u.mgd.bssid, ETH_ALEN);
2842 		build.da_offs = offsetof(struct ieee80211_hdr, addr3);
2843 		build.sa_offs = offsetof(struct ieee80211_hdr, addr2);
2844 		build.hdr_len = 24;
2845 		break;
2846 	case NL80211_IFTYPE_AP_VLAN:
2847 		if (sdata->wdev.use_4addr) {
2848 			fc |= cpu_to_le16(IEEE80211_FCTL_FROMDS |
2849 					  IEEE80211_FCTL_TODS);
2850 			/* RA TA DA SA */
2851 			memcpy(hdr->addr1, sta->sta.addr, ETH_ALEN);
2852 			memcpy(hdr->addr2, sdata->vif.addr, ETH_ALEN);
2853 			build.da_offs = offsetof(struct ieee80211_hdr, addr3);
2854 			build.sa_offs = offsetof(struct ieee80211_hdr, addr4);
2855 			build.hdr_len = 30;
2856 			break;
2857 		}
2858 		/* fall through */
2859 	case NL80211_IFTYPE_AP:
2860 		fc |= cpu_to_le16(IEEE80211_FCTL_FROMDS);
2861 		/* DA BSSID SA */
2862 		build.da_offs = offsetof(struct ieee80211_hdr, addr1);
2863 		memcpy(hdr->addr2, sdata->vif.addr, ETH_ALEN);
2864 		build.sa_offs = offsetof(struct ieee80211_hdr, addr3);
2865 		build.hdr_len = 24;
2866 		break;
2867 	default:
2868 		/* not handled on fast-xmit */
2869 		goto out;
2870 	}
2871 
2872 	if (sta->sta.wme) {
2873 		build.hdr_len += 2;
2874 		fc |= cpu_to_le16(IEEE80211_STYPE_QOS_DATA);
2875 	}
2876 
2877 	/* We store the key here so there's no point in using rcu_dereference()
2878 	 * but that's fine because the code that changes the pointers will call
2879 	 * this function after doing so. For a single CPU that would be enough,
2880 	 * for multiple see the comment above.
2881 	 */
2882 	build.key = rcu_access_pointer(sta->ptk[sta->ptk_idx]);
2883 	if (!build.key)
2884 		build.key = rcu_access_pointer(sdata->default_unicast_key);
2885 	if (build.key) {
2886 		bool gen_iv, iv_spc, mmic;
2887 
2888 		gen_iv = build.key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_IV;
2889 		iv_spc = build.key->conf.flags & IEEE80211_KEY_FLAG_PUT_IV_SPACE;
2890 		mmic = build.key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_MMIC;
2891 
2892 		/* don't handle software crypto */
2893 		if (!(build.key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE))
2894 			goto out;
2895 
2896 		switch (build.key->conf.cipher) {
2897 		case WLAN_CIPHER_SUITE_CCMP:
2898 		case WLAN_CIPHER_SUITE_CCMP_256:
2899 			/* add fixed key ID */
2900 			if (gen_iv) {
2901 				(build.hdr + build.hdr_len)[3] =
2902 					0x20 | (build.key->conf.keyidx << 6);
2903 				build.pn_offs = build.hdr_len;
2904 			}
2905 			if (gen_iv || iv_spc)
2906 				build.hdr_len += IEEE80211_CCMP_HDR_LEN;
2907 			break;
2908 		case WLAN_CIPHER_SUITE_GCMP:
2909 		case WLAN_CIPHER_SUITE_GCMP_256:
2910 			/* add fixed key ID */
2911 			if (gen_iv) {
2912 				(build.hdr + build.hdr_len)[3] =
2913 					0x20 | (build.key->conf.keyidx << 6);
2914 				build.pn_offs = build.hdr_len;
2915 			}
2916 			if (gen_iv || iv_spc)
2917 				build.hdr_len += IEEE80211_GCMP_HDR_LEN;
2918 			break;
2919 		case WLAN_CIPHER_SUITE_TKIP:
2920 			/* cannot handle MMIC or IV generation in xmit-fast */
2921 			if (mmic || gen_iv)
2922 				goto out;
2923 			if (iv_spc)
2924 				build.hdr_len += IEEE80211_TKIP_IV_LEN;
2925 			break;
2926 		case WLAN_CIPHER_SUITE_WEP40:
2927 		case WLAN_CIPHER_SUITE_WEP104:
2928 			/* cannot handle IV generation in fast-xmit */
2929 			if (gen_iv)
2930 				goto out;
2931 			if (iv_spc)
2932 				build.hdr_len += IEEE80211_WEP_IV_LEN;
2933 			break;
2934 		case WLAN_CIPHER_SUITE_AES_CMAC:
2935 		case WLAN_CIPHER_SUITE_BIP_CMAC_256:
2936 		case WLAN_CIPHER_SUITE_BIP_GMAC_128:
2937 		case WLAN_CIPHER_SUITE_BIP_GMAC_256:
2938 			WARN(1,
2939 			     "management cipher suite 0x%x enabled for data\n",
2940 			     build.key->conf.cipher);
2941 			goto out;
2942 		default:
2943 			/* we don't know how to generate IVs for this at all */
2944 			if (WARN_ON(gen_iv))
2945 				goto out;
2946 			/* pure hardware keys are OK, of course */
2947 			if (!(build.key->flags & KEY_FLAG_CIPHER_SCHEME))
2948 				break;
2949 			/* cipher scheme might require space allocation */
2950 			if (iv_spc &&
2951 			    build.key->conf.iv_len > IEEE80211_FAST_XMIT_MAX_IV)
2952 				goto out;
2953 			if (iv_spc)
2954 				build.hdr_len += build.key->conf.iv_len;
2955 		}
2956 
2957 		fc |= cpu_to_le16(IEEE80211_FCTL_PROTECTED);
2958 	}
2959 
2960 	hdr->frame_control = fc;
2961 
2962 	memcpy(build.hdr + build.hdr_len,
2963 	       rfc1042_header,  sizeof(rfc1042_header));
2964 	build.hdr_len += sizeof(rfc1042_header);
2965 
2966 	fast_tx = kmemdup(&build, sizeof(build), GFP_ATOMIC);
2967 	/* if the kmemdup fails, continue w/o fast_tx */
2968 	if (!fast_tx)
2969 		goto out;
2970 
2971  out:
2972 	/* we might have raced against another call to this function */
2973 	old = rcu_dereference_protected(sta->fast_tx,
2974 					lockdep_is_held(&sta->lock));
2975 	rcu_assign_pointer(sta->fast_tx, fast_tx);
2976 	if (old)
2977 		kfree_rcu(old, rcu_head);
2978 	spin_unlock_bh(&sta->lock);
2979 }
2980 
2981 void ieee80211_check_fast_xmit_all(struct ieee80211_local *local)
2982 {
2983 	struct sta_info *sta;
2984 
2985 	rcu_read_lock();
2986 	list_for_each_entry_rcu(sta, &local->sta_list, list)
2987 		ieee80211_check_fast_xmit(sta);
2988 	rcu_read_unlock();
2989 }
2990 
2991 void ieee80211_check_fast_xmit_iface(struct ieee80211_sub_if_data *sdata)
2992 {
2993 	struct ieee80211_local *local = sdata->local;
2994 	struct sta_info *sta;
2995 
2996 	rcu_read_lock();
2997 
2998 	list_for_each_entry_rcu(sta, &local->sta_list, list) {
2999 		if (sdata != sta->sdata &&
3000 		    (!sta->sdata->bss || sta->sdata->bss != sdata->bss))
3001 			continue;
3002 		ieee80211_check_fast_xmit(sta);
3003 	}
3004 
3005 	rcu_read_unlock();
3006 }
3007 
3008 void ieee80211_clear_fast_xmit(struct sta_info *sta)
3009 {
3010 	struct ieee80211_fast_tx *fast_tx;
3011 
3012 	spin_lock_bh(&sta->lock);
3013 	fast_tx = rcu_dereference_protected(sta->fast_tx,
3014 					    lockdep_is_held(&sta->lock));
3015 	RCU_INIT_POINTER(sta->fast_tx, NULL);
3016 	spin_unlock_bh(&sta->lock);
3017 
3018 	if (fast_tx)
3019 		kfree_rcu(fast_tx, rcu_head);
3020 }
3021 
3022 static bool ieee80211_amsdu_realloc_pad(struct ieee80211_local *local,
3023 					struct sk_buff *skb, int headroom,
3024 					int *subframe_len)
3025 {
3026 	int amsdu_len = *subframe_len + sizeof(struct ethhdr);
3027 	int padding = (4 - amsdu_len) & 3;
3028 
3029 	if (skb_headroom(skb) < headroom || skb_tailroom(skb) < padding) {
3030 		I802_DEBUG_INC(local->tx_expand_skb_head);
3031 
3032 		if (pskb_expand_head(skb, headroom, padding, GFP_ATOMIC)) {
3033 			wiphy_debug(local->hw.wiphy,
3034 				    "failed to reallocate TX buffer\n");
3035 			return false;
3036 		}
3037 	}
3038 
3039 	if (padding) {
3040 		*subframe_len += padding;
3041 		memset(skb_put(skb, padding), 0, padding);
3042 	}
3043 
3044 	return true;
3045 }
3046 
3047 static bool ieee80211_amsdu_prepare_head(struct ieee80211_sub_if_data *sdata,
3048 					 struct ieee80211_fast_tx *fast_tx,
3049 					 struct sk_buff *skb)
3050 {
3051 	struct ieee80211_local *local = sdata->local;
3052 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
3053 	struct ieee80211_hdr *hdr;
3054 	struct ethhdr amsdu_hdr;
3055 	int hdr_len = fast_tx->hdr_len - sizeof(rfc1042_header);
3056 	int subframe_len = skb->len - hdr_len;
3057 	void *data;
3058 	u8 *qc;
3059 
3060 	if (info->flags & IEEE80211_TX_CTL_RATE_CTRL_PROBE)
3061 		return false;
3062 
3063 	if (info->control.flags & IEEE80211_TX_CTRL_AMSDU)
3064 		return true;
3065 
3066 	if (!ieee80211_amsdu_realloc_pad(local, skb, sizeof(amsdu_hdr),
3067 					 &subframe_len))
3068 		return false;
3069 
3070 	amsdu_hdr.h_proto = cpu_to_be16(subframe_len);
3071 	memcpy(amsdu_hdr.h_source, skb->data + fast_tx->sa_offs, ETH_ALEN);
3072 	memcpy(amsdu_hdr.h_dest, skb->data + fast_tx->da_offs, ETH_ALEN);
3073 
3074 	data = skb_push(skb, sizeof(amsdu_hdr));
3075 	memmove(data, data + sizeof(amsdu_hdr), hdr_len);
3076 	memcpy(data + hdr_len, &amsdu_hdr, sizeof(amsdu_hdr));
3077 
3078 	hdr = data;
3079 	qc = ieee80211_get_qos_ctl(hdr);
3080 	*qc |= IEEE80211_QOS_CTL_A_MSDU_PRESENT;
3081 
3082 	info->control.flags |= IEEE80211_TX_CTRL_AMSDU;
3083 
3084 	return true;
3085 }
3086 
3087 static bool ieee80211_amsdu_aggregate(struct ieee80211_sub_if_data *sdata,
3088 				      struct sta_info *sta,
3089 				      struct ieee80211_fast_tx *fast_tx,
3090 				      struct sk_buff *skb)
3091 {
3092 	struct ieee80211_local *local = sdata->local;
3093 	struct fq *fq = &local->fq;
3094 	struct fq_tin *tin;
3095 	struct fq_flow *flow;
3096 	u8 tid = skb->priority & IEEE80211_QOS_CTL_TAG1D_MASK;
3097 	struct ieee80211_txq *txq = sta->sta.txq[tid];
3098 	struct txq_info *txqi;
3099 	struct sk_buff **frag_tail, *head;
3100 	int subframe_len = skb->len - ETH_ALEN;
3101 	u8 max_subframes = sta->sta.max_amsdu_subframes;
3102 	int max_frags = local->hw.max_tx_fragments;
3103 	int max_amsdu_len = sta->sta.max_amsdu_len;
3104 	__be16 len;
3105 	void *data;
3106 	bool ret = false;
3107 	unsigned int orig_len;
3108 	int n = 1, nfrags;
3109 
3110 	if (!ieee80211_hw_check(&local->hw, TX_AMSDU))
3111 		return false;
3112 
3113 	if (!txq)
3114 		return false;
3115 
3116 	txqi = to_txq_info(txq);
3117 	if (test_bit(IEEE80211_TXQ_NO_AMSDU, &txqi->flags))
3118 		return false;
3119 
3120 	if (sta->sta.max_rc_amsdu_len)
3121 		max_amsdu_len = min_t(int, max_amsdu_len,
3122 				      sta->sta.max_rc_amsdu_len);
3123 
3124 	spin_lock_bh(&fq->lock);
3125 
3126 	/* TODO: Ideally aggregation should be done on dequeue to remain
3127 	 * responsive to environment changes.
3128 	 */
3129 
3130 	tin = &txqi->tin;
3131 	flow = fq_flow_classify(fq, tin, skb, fq_flow_get_default_func);
3132 	head = skb_peek_tail(&flow->queue);
3133 	if (!head)
3134 		goto out;
3135 
3136 	orig_len = head->len;
3137 
3138 	if (skb->len + head->len > max_amsdu_len)
3139 		goto out;
3140 
3141 	if (!ieee80211_amsdu_prepare_head(sdata, fast_tx, head))
3142 		goto out;
3143 
3144 	nfrags = 1 + skb_shinfo(skb)->nr_frags;
3145 	nfrags += 1 + skb_shinfo(head)->nr_frags;
3146 	frag_tail = &skb_shinfo(head)->frag_list;
3147 	while (*frag_tail) {
3148 		nfrags += 1 + skb_shinfo(*frag_tail)->nr_frags;
3149 		frag_tail = &(*frag_tail)->next;
3150 		n++;
3151 	}
3152 
3153 	if (max_subframes && n > max_subframes)
3154 		goto out;
3155 
3156 	if (max_frags && nfrags > max_frags)
3157 		goto out;
3158 
3159 	if (!ieee80211_amsdu_realloc_pad(local, skb, sizeof(rfc1042_header) + 2,
3160 					 &subframe_len))
3161 		goto out;
3162 
3163 	ret = true;
3164 	data = skb_push(skb, ETH_ALEN + 2);
3165 	memmove(data, data + ETH_ALEN + 2, 2 * ETH_ALEN);
3166 
3167 	data += 2 * ETH_ALEN;
3168 	len = cpu_to_be16(subframe_len);
3169 	memcpy(data, &len, 2);
3170 	memcpy(data + 2, rfc1042_header, sizeof(rfc1042_header));
3171 
3172 	head->len += skb->len;
3173 	head->data_len += skb->len;
3174 	*frag_tail = skb;
3175 
3176 	flow->backlog += head->len - orig_len;
3177 	tin->backlog_bytes += head->len - orig_len;
3178 
3179 	fq_recalc_backlog(fq, tin, flow);
3180 
3181 out:
3182 	spin_unlock_bh(&fq->lock);
3183 
3184 	return ret;
3185 }
3186 
3187 static bool ieee80211_xmit_fast(struct ieee80211_sub_if_data *sdata,
3188 				struct net_device *dev, struct sta_info *sta,
3189 				struct ieee80211_fast_tx *fast_tx,
3190 				struct sk_buff *skb)
3191 {
3192 	struct ieee80211_local *local = sdata->local;
3193 	u16 ethertype = (skb->data[12] << 8) | skb->data[13];
3194 	int extra_head = fast_tx->hdr_len - (ETH_HLEN - 2);
3195 	int hw_headroom = sdata->local->hw.extra_tx_headroom;
3196 	struct ethhdr eth;
3197 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
3198 	struct ieee80211_hdr *hdr = (void *)fast_tx->hdr;
3199 	struct ieee80211_tx_data tx;
3200 	ieee80211_tx_result r;
3201 	struct tid_ampdu_tx *tid_tx = NULL;
3202 	u8 tid = IEEE80211_NUM_TIDS;
3203 
3204 	/* control port protocol needs a lot of special handling */
3205 	if (cpu_to_be16(ethertype) == sdata->control_port_protocol)
3206 		return false;
3207 
3208 	/* only RFC 1042 SNAP */
3209 	if (ethertype < ETH_P_802_3_MIN)
3210 		return false;
3211 
3212 	/* don't handle TX status request here either */
3213 	if (skb->sk && skb_shinfo(skb)->tx_flags & SKBTX_WIFI_STATUS)
3214 		return false;
3215 
3216 	if (hdr->frame_control & cpu_to_le16(IEEE80211_STYPE_QOS_DATA)) {
3217 		tid = skb->priority & IEEE80211_QOS_CTL_TAG1D_MASK;
3218 		tid_tx = rcu_dereference(sta->ampdu_mlme.tid_tx[tid]);
3219 		if (tid_tx) {
3220 			if (!test_bit(HT_AGG_STATE_OPERATIONAL, &tid_tx->state))
3221 				return false;
3222 			if (tid_tx->timeout)
3223 				tid_tx->last_tx = jiffies;
3224 		}
3225 	}
3226 
3227 	/* after this point (skb is modified) we cannot return false */
3228 
3229 	if (skb_shared(skb)) {
3230 		struct sk_buff *tmp_skb = skb;
3231 
3232 		skb = skb_clone(skb, GFP_ATOMIC);
3233 		kfree_skb(tmp_skb);
3234 
3235 		if (!skb)
3236 			return true;
3237 	}
3238 
3239 	ieee80211_tx_stats(dev, skb->len + extra_head);
3240 
3241 	if ((hdr->frame_control & cpu_to_le16(IEEE80211_STYPE_QOS_DATA)) &&
3242 	    ieee80211_amsdu_aggregate(sdata, sta, fast_tx, skb))
3243 		return true;
3244 
3245 	/* will not be crypto-handled beyond what we do here, so use false
3246 	 * as the may-encrypt argument for the resize to not account for
3247 	 * more room than we already have in 'extra_head'
3248 	 */
3249 	if (unlikely(ieee80211_skb_resize(sdata, skb,
3250 					  max_t(int, extra_head + hw_headroom -
3251 						     skb_headroom(skb), 0),
3252 					  false))) {
3253 		kfree_skb(skb);
3254 		return true;
3255 	}
3256 
3257 	memcpy(&eth, skb->data, ETH_HLEN - 2);
3258 	hdr = (void *)skb_push(skb, extra_head);
3259 	memcpy(skb->data, fast_tx->hdr, fast_tx->hdr_len);
3260 	memcpy(skb->data + fast_tx->da_offs, eth.h_dest, ETH_ALEN);
3261 	memcpy(skb->data + fast_tx->sa_offs, eth.h_source, ETH_ALEN);
3262 
3263 	memset(info, 0, sizeof(*info));
3264 	info->band = fast_tx->band;
3265 	info->control.vif = &sdata->vif;
3266 	info->flags = IEEE80211_TX_CTL_FIRST_FRAGMENT |
3267 		      IEEE80211_TX_CTL_DONTFRAG |
3268 		      (tid_tx ? IEEE80211_TX_CTL_AMPDU : 0);
3269 
3270 	if (hdr->frame_control & cpu_to_le16(IEEE80211_STYPE_QOS_DATA)) {
3271 		*ieee80211_get_qos_ctl(hdr) = tid;
3272 		if (!ieee80211_get_txq(local, &sdata->vif, &sta->sta, skb))
3273 			hdr->seq_ctrl = ieee80211_tx_next_seq(sta, tid);
3274 	} else {
3275 		info->flags |= IEEE80211_TX_CTL_ASSIGN_SEQ;
3276 		hdr->seq_ctrl = cpu_to_le16(sdata->sequence_number);
3277 		sdata->sequence_number += 0x10;
3278 	}
3279 
3280 	if (skb_shinfo(skb)->gso_size)
3281 		sta->tx_stats.msdu[tid] +=
3282 			DIV_ROUND_UP(skb->len, skb_shinfo(skb)->gso_size);
3283 	else
3284 		sta->tx_stats.msdu[tid]++;
3285 
3286 	info->hw_queue = sdata->vif.hw_queue[skb_get_queue_mapping(skb)];
3287 
3288 	__skb_queue_head_init(&tx.skbs);
3289 
3290 	tx.flags = IEEE80211_TX_UNICAST;
3291 	tx.local = local;
3292 	tx.sdata = sdata;
3293 	tx.sta = sta;
3294 	tx.key = fast_tx->key;
3295 
3296 	if (fast_tx->key)
3297 		info->control.hw_key = &fast_tx->key->conf;
3298 
3299 	if (!ieee80211_hw_check(&local->hw, HAS_RATE_CONTROL)) {
3300 		tx.skb = skb;
3301 		r = ieee80211_tx_h_rate_ctrl(&tx);
3302 		skb = tx.skb;
3303 		tx.skb = NULL;
3304 
3305 		if (r != TX_CONTINUE) {
3306 			if (r != TX_QUEUED)
3307 				kfree_skb(skb);
3308 			return true;
3309 		}
3310 	}
3311 
3312 	/* statistics normally done by ieee80211_tx_h_stats (but that
3313 	 * has to consider fragmentation, so is more complex)
3314 	 */
3315 	sta->tx_stats.bytes[skb_get_queue_mapping(skb)] += skb->len;
3316 	sta->tx_stats.packets[skb_get_queue_mapping(skb)]++;
3317 
3318 	if (fast_tx->pn_offs) {
3319 		u64 pn;
3320 		u8 *crypto_hdr = skb->data + fast_tx->pn_offs;
3321 
3322 		switch (fast_tx->key->conf.cipher) {
3323 		case WLAN_CIPHER_SUITE_CCMP:
3324 		case WLAN_CIPHER_SUITE_CCMP_256:
3325 		case WLAN_CIPHER_SUITE_GCMP:
3326 		case WLAN_CIPHER_SUITE_GCMP_256:
3327 			pn = atomic64_inc_return(&fast_tx->key->conf.tx_pn);
3328 			crypto_hdr[0] = pn;
3329 			crypto_hdr[1] = pn >> 8;
3330 			crypto_hdr[4] = pn >> 16;
3331 			crypto_hdr[5] = pn >> 24;
3332 			crypto_hdr[6] = pn >> 32;
3333 			crypto_hdr[7] = pn >> 40;
3334 			break;
3335 		}
3336 	}
3337 
3338 	if (sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
3339 		sdata = container_of(sdata->bss,
3340 				     struct ieee80211_sub_if_data, u.ap);
3341 
3342 	__skb_queue_tail(&tx.skbs, skb);
3343 	ieee80211_tx_frags(local, &sdata->vif, &sta->sta, &tx.skbs, false);
3344 	return true;
3345 }
3346 
3347 void __ieee80211_subif_start_xmit(struct sk_buff *skb,
3348 				  struct net_device *dev,
3349 				  u32 info_flags)
3350 {
3351 	struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
3352 	struct sta_info *sta;
3353 	struct sk_buff *next;
3354 
3355 	if (unlikely(skb->len < ETH_HLEN)) {
3356 		kfree_skb(skb);
3357 		return;
3358 	}
3359 
3360 	rcu_read_lock();
3361 
3362 	if (ieee80211_lookup_ra_sta(sdata, skb, &sta))
3363 		goto out_free;
3364 
3365 	if (!IS_ERR_OR_NULL(sta)) {
3366 		struct ieee80211_fast_tx *fast_tx;
3367 
3368 		fast_tx = rcu_dereference(sta->fast_tx);
3369 
3370 		if (fast_tx &&
3371 		    ieee80211_xmit_fast(sdata, dev, sta, fast_tx, skb))
3372 			goto out;
3373 	}
3374 
3375 	if (skb_is_gso(skb)) {
3376 		struct sk_buff *segs;
3377 
3378 		segs = skb_gso_segment(skb, 0);
3379 		if (IS_ERR(segs)) {
3380 			goto out_free;
3381 		} else if (segs) {
3382 			consume_skb(skb);
3383 			skb = segs;
3384 		}
3385 	} else {
3386 		/* we cannot process non-linear frames on this path */
3387 		if (skb_linearize(skb)) {
3388 			kfree_skb(skb);
3389 			goto out;
3390 		}
3391 
3392 		/* the frame could be fragmented, software-encrypted, and other
3393 		 * things so we cannot really handle checksum offload with it -
3394 		 * fix it up in software before we handle anything else.
3395 		 */
3396 		if (skb->ip_summed == CHECKSUM_PARTIAL) {
3397 			skb_set_transport_header(skb,
3398 						 skb_checksum_start_offset(skb));
3399 			if (skb_checksum_help(skb))
3400 				goto out_free;
3401 		}
3402 	}
3403 
3404 	next = skb;
3405 	while (next) {
3406 		skb = next;
3407 		next = skb->next;
3408 
3409 		skb->prev = NULL;
3410 		skb->next = NULL;
3411 
3412 		skb = ieee80211_build_hdr(sdata, skb, info_flags, sta);
3413 		if (IS_ERR(skb))
3414 			goto out;
3415 
3416 		ieee80211_tx_stats(dev, skb->len);
3417 
3418 		ieee80211_xmit(sdata, sta, skb);
3419 	}
3420 	goto out;
3421  out_free:
3422 	kfree_skb(skb);
3423  out:
3424 	rcu_read_unlock();
3425 }
3426 
3427 /**
3428  * ieee80211_subif_start_xmit - netif start_xmit function for 802.3 vifs
3429  * @skb: packet to be sent
3430  * @dev: incoming interface
3431  *
3432  * On failure skb will be freed.
3433  */
3434 netdev_tx_t ieee80211_subif_start_xmit(struct sk_buff *skb,
3435 				       struct net_device *dev)
3436 {
3437 	__ieee80211_subif_start_xmit(skb, dev, 0);
3438 	return NETDEV_TX_OK;
3439 }
3440 
3441 struct sk_buff *
3442 ieee80211_build_data_template(struct ieee80211_sub_if_data *sdata,
3443 			      struct sk_buff *skb, u32 info_flags)
3444 {
3445 	struct ieee80211_hdr *hdr;
3446 	struct ieee80211_tx_data tx = {
3447 		.local = sdata->local,
3448 		.sdata = sdata,
3449 	};
3450 	struct sta_info *sta;
3451 
3452 	rcu_read_lock();
3453 
3454 	if (ieee80211_lookup_ra_sta(sdata, skb, &sta)) {
3455 		kfree_skb(skb);
3456 		skb = ERR_PTR(-EINVAL);
3457 		goto out;
3458 	}
3459 
3460 	skb = ieee80211_build_hdr(sdata, skb, info_flags, sta);
3461 	if (IS_ERR(skb))
3462 		goto out;
3463 
3464 	hdr = (void *)skb->data;
3465 	tx.sta = sta_info_get(sdata, hdr->addr1);
3466 	tx.skb = skb;
3467 
3468 	if (ieee80211_tx_h_select_key(&tx) != TX_CONTINUE) {
3469 		rcu_read_unlock();
3470 		kfree_skb(skb);
3471 		return ERR_PTR(-EINVAL);
3472 	}
3473 
3474 out:
3475 	rcu_read_unlock();
3476 	return skb;
3477 }
3478 
3479 /*
3480  * ieee80211_clear_tx_pending may not be called in a context where
3481  * it is possible that it packets could come in again.
3482  */
3483 void ieee80211_clear_tx_pending(struct ieee80211_local *local)
3484 {
3485 	struct sk_buff *skb;
3486 	int i;
3487 
3488 	for (i = 0; i < local->hw.queues; i++) {
3489 		while ((skb = skb_dequeue(&local->pending[i])) != NULL)
3490 			ieee80211_free_txskb(&local->hw, skb);
3491 	}
3492 }
3493 
3494 /*
3495  * Returns false if the frame couldn't be transmitted but was queued instead,
3496  * which in this case means re-queued -- take as an indication to stop sending
3497  * more pending frames.
3498  */
3499 static bool ieee80211_tx_pending_skb(struct ieee80211_local *local,
3500 				     struct sk_buff *skb)
3501 {
3502 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
3503 	struct ieee80211_sub_if_data *sdata;
3504 	struct sta_info *sta;
3505 	struct ieee80211_hdr *hdr;
3506 	bool result;
3507 	struct ieee80211_chanctx_conf *chanctx_conf;
3508 
3509 	sdata = vif_to_sdata(info->control.vif);
3510 
3511 	if (info->flags & IEEE80211_TX_INTFL_NEED_TXPROCESSING) {
3512 		chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);
3513 		if (unlikely(!chanctx_conf)) {
3514 			dev_kfree_skb(skb);
3515 			return true;
3516 		}
3517 		info->band = chanctx_conf->def.chan->band;
3518 		result = ieee80211_tx(sdata, NULL, skb, true);
3519 	} else {
3520 		struct sk_buff_head skbs;
3521 
3522 		__skb_queue_head_init(&skbs);
3523 		__skb_queue_tail(&skbs, skb);
3524 
3525 		hdr = (struct ieee80211_hdr *)skb->data;
3526 		sta = sta_info_get(sdata, hdr->addr1);
3527 
3528 		result = __ieee80211_tx(local, &skbs, skb->len, sta, true);
3529 	}
3530 
3531 	return result;
3532 }
3533 
3534 /*
3535  * Transmit all pending packets. Called from tasklet.
3536  */
3537 void ieee80211_tx_pending(unsigned long data)
3538 {
3539 	struct ieee80211_local *local = (struct ieee80211_local *)data;
3540 	unsigned long flags;
3541 	int i;
3542 	bool txok;
3543 
3544 	rcu_read_lock();
3545 
3546 	spin_lock_irqsave(&local->queue_stop_reason_lock, flags);
3547 	for (i = 0; i < local->hw.queues; i++) {
3548 		/*
3549 		 * If queue is stopped by something other than due to pending
3550 		 * frames, or we have no pending frames, proceed to next queue.
3551 		 */
3552 		if (local->queue_stop_reasons[i] ||
3553 		    skb_queue_empty(&local->pending[i]))
3554 			continue;
3555 
3556 		while (!skb_queue_empty(&local->pending[i])) {
3557 			struct sk_buff *skb = __skb_dequeue(&local->pending[i]);
3558 			struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
3559 
3560 			if (WARN_ON(!info->control.vif)) {
3561 				ieee80211_free_txskb(&local->hw, skb);
3562 				continue;
3563 			}
3564 
3565 			spin_unlock_irqrestore(&local->queue_stop_reason_lock,
3566 						flags);
3567 
3568 			txok = ieee80211_tx_pending_skb(local, skb);
3569 			spin_lock_irqsave(&local->queue_stop_reason_lock,
3570 					  flags);
3571 			if (!txok)
3572 				break;
3573 		}
3574 
3575 		if (skb_queue_empty(&local->pending[i]))
3576 			ieee80211_propagate_queue_wake(local, i);
3577 	}
3578 	spin_unlock_irqrestore(&local->queue_stop_reason_lock, flags);
3579 
3580 	rcu_read_unlock();
3581 }
3582 
3583 /* functions for drivers to get certain frames */
3584 
3585 static void __ieee80211_beacon_add_tim(struct ieee80211_sub_if_data *sdata,
3586 				       struct ps_data *ps, struct sk_buff *skb,
3587 				       bool is_template)
3588 {
3589 	u8 *pos, *tim;
3590 	int aid0 = 0;
3591 	int i, have_bits = 0, n1, n2;
3592 
3593 	/* Generate bitmap for TIM only if there are any STAs in power save
3594 	 * mode. */
3595 	if (atomic_read(&ps->num_sta_ps) > 0)
3596 		/* in the hope that this is faster than
3597 		 * checking byte-for-byte */
3598 		have_bits = !bitmap_empty((unsigned long *)ps->tim,
3599 					  IEEE80211_MAX_AID+1);
3600 	if (!is_template) {
3601 		if (ps->dtim_count == 0)
3602 			ps->dtim_count = sdata->vif.bss_conf.dtim_period - 1;
3603 		else
3604 			ps->dtim_count--;
3605 	}
3606 
3607 	tim = pos = (u8 *) skb_put(skb, 6);
3608 	*pos++ = WLAN_EID_TIM;
3609 	*pos++ = 4;
3610 	*pos++ = ps->dtim_count;
3611 	*pos++ = sdata->vif.bss_conf.dtim_period;
3612 
3613 	if (ps->dtim_count == 0 && !skb_queue_empty(&ps->bc_buf))
3614 		aid0 = 1;
3615 
3616 	ps->dtim_bc_mc = aid0 == 1;
3617 
3618 	if (have_bits) {
3619 		/* Find largest even number N1 so that bits numbered 1 through
3620 		 * (N1 x 8) - 1 in the bitmap are 0 and number N2 so that bits
3621 		 * (N2 + 1) x 8 through 2007 are 0. */
3622 		n1 = 0;
3623 		for (i = 0; i < IEEE80211_MAX_TIM_LEN; i++) {
3624 			if (ps->tim[i]) {
3625 				n1 = i & 0xfe;
3626 				break;
3627 			}
3628 		}
3629 		n2 = n1;
3630 		for (i = IEEE80211_MAX_TIM_LEN - 1; i >= n1; i--) {
3631 			if (ps->tim[i]) {
3632 				n2 = i;
3633 				break;
3634 			}
3635 		}
3636 
3637 		/* Bitmap control */
3638 		*pos++ = n1 | aid0;
3639 		/* Part Virt Bitmap */
3640 		skb_put(skb, n2 - n1);
3641 		memcpy(pos, ps->tim + n1, n2 - n1 + 1);
3642 
3643 		tim[1] = n2 - n1 + 4;
3644 	} else {
3645 		*pos++ = aid0; /* Bitmap control */
3646 		*pos++ = 0; /* Part Virt Bitmap */
3647 	}
3648 }
3649 
3650 static int ieee80211_beacon_add_tim(struct ieee80211_sub_if_data *sdata,
3651 				    struct ps_data *ps, struct sk_buff *skb,
3652 				    bool is_template)
3653 {
3654 	struct ieee80211_local *local = sdata->local;
3655 
3656 	/*
3657 	 * Not very nice, but we want to allow the driver to call
3658 	 * ieee80211_beacon_get() as a response to the set_tim()
3659 	 * callback. That, however, is already invoked under the
3660 	 * sta_lock to guarantee consistent and race-free update
3661 	 * of the tim bitmap in mac80211 and the driver.
3662 	 */
3663 	if (local->tim_in_locked_section) {
3664 		__ieee80211_beacon_add_tim(sdata, ps, skb, is_template);
3665 	} else {
3666 		spin_lock_bh(&local->tim_lock);
3667 		__ieee80211_beacon_add_tim(sdata, ps, skb, is_template);
3668 		spin_unlock_bh(&local->tim_lock);
3669 	}
3670 
3671 	return 0;
3672 }
3673 
3674 static void ieee80211_set_csa(struct ieee80211_sub_if_data *sdata,
3675 			      struct beacon_data *beacon)
3676 {
3677 	struct probe_resp *resp;
3678 	u8 *beacon_data;
3679 	size_t beacon_data_len;
3680 	int i;
3681 	u8 count = beacon->csa_current_counter;
3682 
3683 	switch (sdata->vif.type) {
3684 	case NL80211_IFTYPE_AP:
3685 		beacon_data = beacon->tail;
3686 		beacon_data_len = beacon->tail_len;
3687 		break;
3688 	case NL80211_IFTYPE_ADHOC:
3689 		beacon_data = beacon->head;
3690 		beacon_data_len = beacon->head_len;
3691 		break;
3692 	case NL80211_IFTYPE_MESH_POINT:
3693 		beacon_data = beacon->head;
3694 		beacon_data_len = beacon->head_len;
3695 		break;
3696 	default:
3697 		return;
3698 	}
3699 
3700 	rcu_read_lock();
3701 	for (i = 0; i < IEEE80211_MAX_CSA_COUNTERS_NUM; ++i) {
3702 		resp = rcu_dereference(sdata->u.ap.probe_resp);
3703 
3704 		if (beacon->csa_counter_offsets[i]) {
3705 			if (WARN_ON_ONCE(beacon->csa_counter_offsets[i] >=
3706 					 beacon_data_len)) {
3707 				rcu_read_unlock();
3708 				return;
3709 			}
3710 
3711 			beacon_data[beacon->csa_counter_offsets[i]] = count;
3712 		}
3713 
3714 		if (sdata->vif.type == NL80211_IFTYPE_AP && resp)
3715 			resp->data[resp->csa_counter_offsets[i]] = count;
3716 	}
3717 	rcu_read_unlock();
3718 }
3719 
3720 static u8 __ieee80211_csa_update_counter(struct beacon_data *beacon)
3721 {
3722 	beacon->csa_current_counter--;
3723 
3724 	/* the counter should never reach 0 */
3725 	WARN_ON_ONCE(!beacon->csa_current_counter);
3726 
3727 	return beacon->csa_current_counter;
3728 }
3729 
3730 u8 ieee80211_csa_update_counter(struct ieee80211_vif *vif)
3731 {
3732 	struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
3733 	struct beacon_data *beacon = NULL;
3734 	u8 count = 0;
3735 
3736 	rcu_read_lock();
3737 
3738 	if (sdata->vif.type == NL80211_IFTYPE_AP)
3739 		beacon = rcu_dereference(sdata->u.ap.beacon);
3740 	else if (sdata->vif.type == NL80211_IFTYPE_ADHOC)
3741 		beacon = rcu_dereference(sdata->u.ibss.presp);
3742 	else if (ieee80211_vif_is_mesh(&sdata->vif))
3743 		beacon = rcu_dereference(sdata->u.mesh.beacon);
3744 
3745 	if (!beacon)
3746 		goto unlock;
3747 
3748 	count = __ieee80211_csa_update_counter(beacon);
3749 
3750 unlock:
3751 	rcu_read_unlock();
3752 	return count;
3753 }
3754 EXPORT_SYMBOL(ieee80211_csa_update_counter);
3755 
3756 bool ieee80211_csa_is_complete(struct ieee80211_vif *vif)
3757 {
3758 	struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
3759 	struct beacon_data *beacon = NULL;
3760 	u8 *beacon_data;
3761 	size_t beacon_data_len;
3762 	int ret = false;
3763 
3764 	if (!ieee80211_sdata_running(sdata))
3765 		return false;
3766 
3767 	rcu_read_lock();
3768 	if (vif->type == NL80211_IFTYPE_AP) {
3769 		struct ieee80211_if_ap *ap = &sdata->u.ap;
3770 
3771 		beacon = rcu_dereference(ap->beacon);
3772 		if (WARN_ON(!beacon || !beacon->tail))
3773 			goto out;
3774 		beacon_data = beacon->tail;
3775 		beacon_data_len = beacon->tail_len;
3776 	} else if (vif->type == NL80211_IFTYPE_ADHOC) {
3777 		struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
3778 
3779 		beacon = rcu_dereference(ifibss->presp);
3780 		if (!beacon)
3781 			goto out;
3782 
3783 		beacon_data = beacon->head;
3784 		beacon_data_len = beacon->head_len;
3785 	} else if (vif->type == NL80211_IFTYPE_MESH_POINT) {
3786 		struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
3787 
3788 		beacon = rcu_dereference(ifmsh->beacon);
3789 		if (!beacon)
3790 			goto out;
3791 
3792 		beacon_data = beacon->head;
3793 		beacon_data_len = beacon->head_len;
3794 	} else {
3795 		WARN_ON(1);
3796 		goto out;
3797 	}
3798 
3799 	if (!beacon->csa_counter_offsets[0])
3800 		goto out;
3801 
3802 	if (WARN_ON_ONCE(beacon->csa_counter_offsets[0] > beacon_data_len))
3803 		goto out;
3804 
3805 	if (beacon_data[beacon->csa_counter_offsets[0]] == 1)
3806 		ret = true;
3807  out:
3808 	rcu_read_unlock();
3809 
3810 	return ret;
3811 }
3812 EXPORT_SYMBOL(ieee80211_csa_is_complete);
3813 
3814 static struct sk_buff *
3815 __ieee80211_beacon_get(struct ieee80211_hw *hw,
3816 		       struct ieee80211_vif *vif,
3817 		       struct ieee80211_mutable_offsets *offs,
3818 		       bool is_template)
3819 {
3820 	struct ieee80211_local *local = hw_to_local(hw);
3821 	struct beacon_data *beacon = NULL;
3822 	struct sk_buff *skb = NULL;
3823 	struct ieee80211_tx_info *info;
3824 	struct ieee80211_sub_if_data *sdata = NULL;
3825 	enum nl80211_band band;
3826 	struct ieee80211_tx_rate_control txrc;
3827 	struct ieee80211_chanctx_conf *chanctx_conf;
3828 	int csa_off_base = 0;
3829 
3830 	rcu_read_lock();
3831 
3832 	sdata = vif_to_sdata(vif);
3833 	chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);
3834 
3835 	if (!ieee80211_sdata_running(sdata) || !chanctx_conf)
3836 		goto out;
3837 
3838 	if (offs)
3839 		memset(offs, 0, sizeof(*offs));
3840 
3841 	if (sdata->vif.type == NL80211_IFTYPE_AP) {
3842 		struct ieee80211_if_ap *ap = &sdata->u.ap;
3843 
3844 		beacon = rcu_dereference(ap->beacon);
3845 		if (beacon) {
3846 			if (beacon->csa_counter_offsets[0]) {
3847 				if (!is_template)
3848 					__ieee80211_csa_update_counter(beacon);
3849 
3850 				ieee80211_set_csa(sdata, beacon);
3851 			}
3852 
3853 			/*
3854 			 * headroom, head length,
3855 			 * tail length and maximum TIM length
3856 			 */
3857 			skb = dev_alloc_skb(local->tx_headroom +
3858 					    beacon->head_len +
3859 					    beacon->tail_len + 256 +
3860 					    local->hw.extra_beacon_tailroom);
3861 			if (!skb)
3862 				goto out;
3863 
3864 			skb_reserve(skb, local->tx_headroom);
3865 			memcpy(skb_put(skb, beacon->head_len), beacon->head,
3866 			       beacon->head_len);
3867 
3868 			ieee80211_beacon_add_tim(sdata, &ap->ps, skb,
3869 						 is_template);
3870 
3871 			if (offs) {
3872 				offs->tim_offset = beacon->head_len;
3873 				offs->tim_length = skb->len - beacon->head_len;
3874 
3875 				/* for AP the csa offsets are from tail */
3876 				csa_off_base = skb->len;
3877 			}
3878 
3879 			if (beacon->tail)
3880 				memcpy(skb_put(skb, beacon->tail_len),
3881 				       beacon->tail, beacon->tail_len);
3882 		} else
3883 			goto out;
3884 	} else if (sdata->vif.type == NL80211_IFTYPE_ADHOC) {
3885 		struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
3886 		struct ieee80211_hdr *hdr;
3887 
3888 		beacon = rcu_dereference(ifibss->presp);
3889 		if (!beacon)
3890 			goto out;
3891 
3892 		if (beacon->csa_counter_offsets[0]) {
3893 			if (!is_template)
3894 				__ieee80211_csa_update_counter(beacon);
3895 
3896 			ieee80211_set_csa(sdata, beacon);
3897 		}
3898 
3899 		skb = dev_alloc_skb(local->tx_headroom + beacon->head_len +
3900 				    local->hw.extra_beacon_tailroom);
3901 		if (!skb)
3902 			goto out;
3903 		skb_reserve(skb, local->tx_headroom);
3904 		memcpy(skb_put(skb, beacon->head_len), beacon->head,
3905 		       beacon->head_len);
3906 
3907 		hdr = (struct ieee80211_hdr *) skb->data;
3908 		hdr->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
3909 						 IEEE80211_STYPE_BEACON);
3910 	} else if (ieee80211_vif_is_mesh(&sdata->vif)) {
3911 		struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
3912 
3913 		beacon = rcu_dereference(ifmsh->beacon);
3914 		if (!beacon)
3915 			goto out;
3916 
3917 		if (beacon->csa_counter_offsets[0]) {
3918 			if (!is_template)
3919 				/* TODO: For mesh csa_counter is in TU, so
3920 				 * decrementing it by one isn't correct, but
3921 				 * for now we leave it consistent with overall
3922 				 * mac80211's behavior.
3923 				 */
3924 				__ieee80211_csa_update_counter(beacon);
3925 
3926 			ieee80211_set_csa(sdata, beacon);
3927 		}
3928 
3929 		if (ifmsh->sync_ops)
3930 			ifmsh->sync_ops->adjust_tbtt(sdata, beacon);
3931 
3932 		skb = dev_alloc_skb(local->tx_headroom +
3933 				    beacon->head_len +
3934 				    256 + /* TIM IE */
3935 				    beacon->tail_len +
3936 				    local->hw.extra_beacon_tailroom);
3937 		if (!skb)
3938 			goto out;
3939 		skb_reserve(skb, local->tx_headroom);
3940 		memcpy(skb_put(skb, beacon->head_len), beacon->head,
3941 		       beacon->head_len);
3942 		ieee80211_beacon_add_tim(sdata, &ifmsh->ps, skb, is_template);
3943 
3944 		if (offs) {
3945 			offs->tim_offset = beacon->head_len;
3946 			offs->tim_length = skb->len - beacon->head_len;
3947 		}
3948 
3949 		memcpy(skb_put(skb, beacon->tail_len), beacon->tail,
3950 		       beacon->tail_len);
3951 	} else {
3952 		WARN_ON(1);
3953 		goto out;
3954 	}
3955 
3956 	/* CSA offsets */
3957 	if (offs && beacon) {
3958 		int i;
3959 
3960 		for (i = 0; i < IEEE80211_MAX_CSA_COUNTERS_NUM; i++) {
3961 			u16 csa_off = beacon->csa_counter_offsets[i];
3962 
3963 			if (!csa_off)
3964 				continue;
3965 
3966 			offs->csa_counter_offs[i] = csa_off_base + csa_off;
3967 		}
3968 	}
3969 
3970 	band = chanctx_conf->def.chan->band;
3971 
3972 	info = IEEE80211_SKB_CB(skb);
3973 
3974 	info->flags |= IEEE80211_TX_INTFL_DONT_ENCRYPT;
3975 	info->flags |= IEEE80211_TX_CTL_NO_ACK;
3976 	info->band = band;
3977 
3978 	memset(&txrc, 0, sizeof(txrc));
3979 	txrc.hw = hw;
3980 	txrc.sband = local->hw.wiphy->bands[band];
3981 	txrc.bss_conf = &sdata->vif.bss_conf;
3982 	txrc.skb = skb;
3983 	txrc.reported_rate.idx = -1;
3984 	txrc.rate_idx_mask = sdata->rc_rateidx_mask[band];
3985 	if (txrc.rate_idx_mask == (1 << txrc.sband->n_bitrates) - 1)
3986 		txrc.max_rate_idx = -1;
3987 	else
3988 		txrc.max_rate_idx = fls(txrc.rate_idx_mask) - 1;
3989 	txrc.bss = true;
3990 	rate_control_get_rate(sdata, NULL, &txrc);
3991 
3992 	info->control.vif = vif;
3993 
3994 	info->flags |= IEEE80211_TX_CTL_CLEAR_PS_FILT |
3995 			IEEE80211_TX_CTL_ASSIGN_SEQ |
3996 			IEEE80211_TX_CTL_FIRST_FRAGMENT;
3997  out:
3998 	rcu_read_unlock();
3999 	return skb;
4000 
4001 }
4002 
4003 struct sk_buff *
4004 ieee80211_beacon_get_template(struct ieee80211_hw *hw,
4005 			      struct ieee80211_vif *vif,
4006 			      struct ieee80211_mutable_offsets *offs)
4007 {
4008 	return __ieee80211_beacon_get(hw, vif, offs, true);
4009 }
4010 EXPORT_SYMBOL(ieee80211_beacon_get_template);
4011 
4012 struct sk_buff *ieee80211_beacon_get_tim(struct ieee80211_hw *hw,
4013 					 struct ieee80211_vif *vif,
4014 					 u16 *tim_offset, u16 *tim_length)
4015 {
4016 	struct ieee80211_mutable_offsets offs = {};
4017 	struct sk_buff *bcn = __ieee80211_beacon_get(hw, vif, &offs, false);
4018 	struct sk_buff *copy;
4019 	struct ieee80211_supported_band *sband;
4020 	int shift;
4021 
4022 	if (!bcn)
4023 		return bcn;
4024 
4025 	if (tim_offset)
4026 		*tim_offset = offs.tim_offset;
4027 
4028 	if (tim_length)
4029 		*tim_length = offs.tim_length;
4030 
4031 	if (ieee80211_hw_check(hw, BEACON_TX_STATUS) ||
4032 	    !hw_to_local(hw)->monitors)
4033 		return bcn;
4034 
4035 	/* send a copy to monitor interfaces */
4036 	copy = skb_copy(bcn, GFP_ATOMIC);
4037 	if (!copy)
4038 		return bcn;
4039 
4040 	shift = ieee80211_vif_get_shift(vif);
4041 	sband = hw->wiphy->bands[ieee80211_get_sdata_band(vif_to_sdata(vif))];
4042 	ieee80211_tx_monitor(hw_to_local(hw), copy, sband, 1, shift, false);
4043 
4044 	return bcn;
4045 }
4046 EXPORT_SYMBOL(ieee80211_beacon_get_tim);
4047 
4048 struct sk_buff *ieee80211_proberesp_get(struct ieee80211_hw *hw,
4049 					struct ieee80211_vif *vif)
4050 {
4051 	struct ieee80211_if_ap *ap = NULL;
4052 	struct sk_buff *skb = NULL;
4053 	struct probe_resp *presp = NULL;
4054 	struct ieee80211_hdr *hdr;
4055 	struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
4056 
4057 	if (sdata->vif.type != NL80211_IFTYPE_AP)
4058 		return NULL;
4059 
4060 	rcu_read_lock();
4061 
4062 	ap = &sdata->u.ap;
4063 	presp = rcu_dereference(ap->probe_resp);
4064 	if (!presp)
4065 		goto out;
4066 
4067 	skb = dev_alloc_skb(presp->len);
4068 	if (!skb)
4069 		goto out;
4070 
4071 	memcpy(skb_put(skb, presp->len), presp->data, presp->len);
4072 
4073 	hdr = (struct ieee80211_hdr *) skb->data;
4074 	memset(hdr->addr1, 0, sizeof(hdr->addr1));
4075 
4076 out:
4077 	rcu_read_unlock();
4078 	return skb;
4079 }
4080 EXPORT_SYMBOL(ieee80211_proberesp_get);
4081 
4082 struct sk_buff *ieee80211_pspoll_get(struct ieee80211_hw *hw,
4083 				     struct ieee80211_vif *vif)
4084 {
4085 	struct ieee80211_sub_if_data *sdata;
4086 	struct ieee80211_if_managed *ifmgd;
4087 	struct ieee80211_pspoll *pspoll;
4088 	struct ieee80211_local *local;
4089 	struct sk_buff *skb;
4090 
4091 	if (WARN_ON(vif->type != NL80211_IFTYPE_STATION))
4092 		return NULL;
4093 
4094 	sdata = vif_to_sdata(vif);
4095 	ifmgd = &sdata->u.mgd;
4096 	local = sdata->local;
4097 
4098 	skb = dev_alloc_skb(local->hw.extra_tx_headroom + sizeof(*pspoll));
4099 	if (!skb)
4100 		return NULL;
4101 
4102 	skb_reserve(skb, local->hw.extra_tx_headroom);
4103 
4104 	pspoll = (struct ieee80211_pspoll *) skb_put(skb, sizeof(*pspoll));
4105 	memset(pspoll, 0, sizeof(*pspoll));
4106 	pspoll->frame_control = cpu_to_le16(IEEE80211_FTYPE_CTL |
4107 					    IEEE80211_STYPE_PSPOLL);
4108 	pspoll->aid = cpu_to_le16(ifmgd->aid);
4109 
4110 	/* aid in PS-Poll has its two MSBs each set to 1 */
4111 	pspoll->aid |= cpu_to_le16(1 << 15 | 1 << 14);
4112 
4113 	memcpy(pspoll->bssid, ifmgd->bssid, ETH_ALEN);
4114 	memcpy(pspoll->ta, vif->addr, ETH_ALEN);
4115 
4116 	return skb;
4117 }
4118 EXPORT_SYMBOL(ieee80211_pspoll_get);
4119 
4120 struct sk_buff *ieee80211_nullfunc_get(struct ieee80211_hw *hw,
4121 				       struct ieee80211_vif *vif)
4122 {
4123 	struct ieee80211_hdr_3addr *nullfunc;
4124 	struct ieee80211_sub_if_data *sdata;
4125 	struct ieee80211_if_managed *ifmgd;
4126 	struct ieee80211_local *local;
4127 	struct sk_buff *skb;
4128 
4129 	if (WARN_ON(vif->type != NL80211_IFTYPE_STATION))
4130 		return NULL;
4131 
4132 	sdata = vif_to_sdata(vif);
4133 	ifmgd = &sdata->u.mgd;
4134 	local = sdata->local;
4135 
4136 	skb = dev_alloc_skb(local->hw.extra_tx_headroom + sizeof(*nullfunc));
4137 	if (!skb)
4138 		return NULL;
4139 
4140 	skb_reserve(skb, local->hw.extra_tx_headroom);
4141 
4142 	nullfunc = (struct ieee80211_hdr_3addr *) skb_put(skb,
4143 							  sizeof(*nullfunc));
4144 	memset(nullfunc, 0, sizeof(*nullfunc));
4145 	nullfunc->frame_control = cpu_to_le16(IEEE80211_FTYPE_DATA |
4146 					      IEEE80211_STYPE_NULLFUNC |
4147 					      IEEE80211_FCTL_TODS);
4148 	memcpy(nullfunc->addr1, ifmgd->bssid, ETH_ALEN);
4149 	memcpy(nullfunc->addr2, vif->addr, ETH_ALEN);
4150 	memcpy(nullfunc->addr3, ifmgd->bssid, ETH_ALEN);
4151 
4152 	return skb;
4153 }
4154 EXPORT_SYMBOL(ieee80211_nullfunc_get);
4155 
4156 struct sk_buff *ieee80211_probereq_get(struct ieee80211_hw *hw,
4157 				       const u8 *src_addr,
4158 				       const u8 *ssid, size_t ssid_len,
4159 				       size_t tailroom)
4160 {
4161 	struct ieee80211_local *local = hw_to_local(hw);
4162 	struct ieee80211_hdr_3addr *hdr;
4163 	struct sk_buff *skb;
4164 	size_t ie_ssid_len;
4165 	u8 *pos;
4166 
4167 	ie_ssid_len = 2 + ssid_len;
4168 
4169 	skb = dev_alloc_skb(local->hw.extra_tx_headroom + sizeof(*hdr) +
4170 			    ie_ssid_len + tailroom);
4171 	if (!skb)
4172 		return NULL;
4173 
4174 	skb_reserve(skb, local->hw.extra_tx_headroom);
4175 
4176 	hdr = (struct ieee80211_hdr_3addr *) skb_put(skb, sizeof(*hdr));
4177 	memset(hdr, 0, sizeof(*hdr));
4178 	hdr->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
4179 					 IEEE80211_STYPE_PROBE_REQ);
4180 	eth_broadcast_addr(hdr->addr1);
4181 	memcpy(hdr->addr2, src_addr, ETH_ALEN);
4182 	eth_broadcast_addr(hdr->addr3);
4183 
4184 	pos = skb_put(skb, ie_ssid_len);
4185 	*pos++ = WLAN_EID_SSID;
4186 	*pos++ = ssid_len;
4187 	if (ssid_len)
4188 		memcpy(pos, ssid, ssid_len);
4189 	pos += ssid_len;
4190 
4191 	return skb;
4192 }
4193 EXPORT_SYMBOL(ieee80211_probereq_get);
4194 
4195 void ieee80211_rts_get(struct ieee80211_hw *hw, struct ieee80211_vif *vif,
4196 		       const void *frame, size_t frame_len,
4197 		       const struct ieee80211_tx_info *frame_txctl,
4198 		       struct ieee80211_rts *rts)
4199 {
4200 	const struct ieee80211_hdr *hdr = frame;
4201 
4202 	rts->frame_control =
4203 	    cpu_to_le16(IEEE80211_FTYPE_CTL | IEEE80211_STYPE_RTS);
4204 	rts->duration = ieee80211_rts_duration(hw, vif, frame_len,
4205 					       frame_txctl);
4206 	memcpy(rts->ra, hdr->addr1, sizeof(rts->ra));
4207 	memcpy(rts->ta, hdr->addr2, sizeof(rts->ta));
4208 }
4209 EXPORT_SYMBOL(ieee80211_rts_get);
4210 
4211 void ieee80211_ctstoself_get(struct ieee80211_hw *hw, struct ieee80211_vif *vif,
4212 			     const void *frame, size_t frame_len,
4213 			     const struct ieee80211_tx_info *frame_txctl,
4214 			     struct ieee80211_cts *cts)
4215 {
4216 	const struct ieee80211_hdr *hdr = frame;
4217 
4218 	cts->frame_control =
4219 	    cpu_to_le16(IEEE80211_FTYPE_CTL | IEEE80211_STYPE_CTS);
4220 	cts->duration = ieee80211_ctstoself_duration(hw, vif,
4221 						     frame_len, frame_txctl);
4222 	memcpy(cts->ra, hdr->addr1, sizeof(cts->ra));
4223 }
4224 EXPORT_SYMBOL(ieee80211_ctstoself_get);
4225 
4226 struct sk_buff *
4227 ieee80211_get_buffered_bc(struct ieee80211_hw *hw,
4228 			  struct ieee80211_vif *vif)
4229 {
4230 	struct ieee80211_local *local = hw_to_local(hw);
4231 	struct sk_buff *skb = NULL;
4232 	struct ieee80211_tx_data tx;
4233 	struct ieee80211_sub_if_data *sdata;
4234 	struct ps_data *ps;
4235 	struct ieee80211_tx_info *info;
4236 	struct ieee80211_chanctx_conf *chanctx_conf;
4237 
4238 	sdata = vif_to_sdata(vif);
4239 
4240 	rcu_read_lock();
4241 	chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);
4242 
4243 	if (!chanctx_conf)
4244 		goto out;
4245 
4246 	if (sdata->vif.type == NL80211_IFTYPE_AP) {
4247 		struct beacon_data *beacon =
4248 				rcu_dereference(sdata->u.ap.beacon);
4249 
4250 		if (!beacon || !beacon->head)
4251 			goto out;
4252 
4253 		ps = &sdata->u.ap.ps;
4254 	} else if (ieee80211_vif_is_mesh(&sdata->vif)) {
4255 		ps = &sdata->u.mesh.ps;
4256 	} else {
4257 		goto out;
4258 	}
4259 
4260 	if (ps->dtim_count != 0 || !ps->dtim_bc_mc)
4261 		goto out; /* send buffered bc/mc only after DTIM beacon */
4262 
4263 	while (1) {
4264 		skb = skb_dequeue(&ps->bc_buf);
4265 		if (!skb)
4266 			goto out;
4267 		local->total_ps_buffered--;
4268 
4269 		if (!skb_queue_empty(&ps->bc_buf) && skb->len >= 2) {
4270 			struct ieee80211_hdr *hdr =
4271 				(struct ieee80211_hdr *) skb->data;
4272 			/* more buffered multicast/broadcast frames ==> set
4273 			 * MoreData flag in IEEE 802.11 header to inform PS
4274 			 * STAs */
4275 			hdr->frame_control |=
4276 				cpu_to_le16(IEEE80211_FCTL_MOREDATA);
4277 		}
4278 
4279 		if (sdata->vif.type == NL80211_IFTYPE_AP)
4280 			sdata = IEEE80211_DEV_TO_SUB_IF(skb->dev);
4281 		if (!ieee80211_tx_prepare(sdata, &tx, NULL, skb))
4282 			break;
4283 		ieee80211_free_txskb(hw, skb);
4284 	}
4285 
4286 	info = IEEE80211_SKB_CB(skb);
4287 
4288 	tx.flags |= IEEE80211_TX_PS_BUFFERED;
4289 	info->band = chanctx_conf->def.chan->band;
4290 
4291 	if (invoke_tx_handlers(&tx))
4292 		skb = NULL;
4293  out:
4294 	rcu_read_unlock();
4295 
4296 	return skb;
4297 }
4298 EXPORT_SYMBOL(ieee80211_get_buffered_bc);
4299 
4300 int ieee80211_reserve_tid(struct ieee80211_sta *pubsta, u8 tid)
4301 {
4302 	struct sta_info *sta = container_of(pubsta, struct sta_info, sta);
4303 	struct ieee80211_sub_if_data *sdata = sta->sdata;
4304 	struct ieee80211_local *local = sdata->local;
4305 	int ret;
4306 	u32 queues;
4307 
4308 	lockdep_assert_held(&local->sta_mtx);
4309 
4310 	/* only some cases are supported right now */
4311 	switch (sdata->vif.type) {
4312 	case NL80211_IFTYPE_STATION:
4313 	case NL80211_IFTYPE_AP:
4314 	case NL80211_IFTYPE_AP_VLAN:
4315 		break;
4316 	default:
4317 		WARN_ON(1);
4318 		return -EINVAL;
4319 	}
4320 
4321 	if (WARN_ON(tid >= IEEE80211_NUM_UPS))
4322 		return -EINVAL;
4323 
4324 	if (sta->reserved_tid == tid) {
4325 		ret = 0;
4326 		goto out;
4327 	}
4328 
4329 	if (sta->reserved_tid != IEEE80211_TID_UNRESERVED) {
4330 		sdata_err(sdata, "TID reservation already active\n");
4331 		ret = -EALREADY;
4332 		goto out;
4333 	}
4334 
4335 	ieee80211_stop_vif_queues(sdata->local, sdata,
4336 				  IEEE80211_QUEUE_STOP_REASON_RESERVE_TID);
4337 
4338 	synchronize_net();
4339 
4340 	/* Tear down BA sessions so we stop aggregating on this TID */
4341 	if (ieee80211_hw_check(&local->hw, AMPDU_AGGREGATION)) {
4342 		set_sta_flag(sta, WLAN_STA_BLOCK_BA);
4343 		__ieee80211_stop_tx_ba_session(sta, tid,
4344 					       AGG_STOP_LOCAL_REQUEST);
4345 	}
4346 
4347 	queues = BIT(sdata->vif.hw_queue[ieee802_1d_to_ac[tid]]);
4348 	__ieee80211_flush_queues(local, sdata, queues, false);
4349 
4350 	sta->reserved_tid = tid;
4351 
4352 	ieee80211_wake_vif_queues(local, sdata,
4353 				  IEEE80211_QUEUE_STOP_REASON_RESERVE_TID);
4354 
4355 	if (ieee80211_hw_check(&local->hw, AMPDU_AGGREGATION))
4356 		clear_sta_flag(sta, WLAN_STA_BLOCK_BA);
4357 
4358 	ret = 0;
4359  out:
4360 	return ret;
4361 }
4362 EXPORT_SYMBOL(ieee80211_reserve_tid);
4363 
4364 void ieee80211_unreserve_tid(struct ieee80211_sta *pubsta, u8 tid)
4365 {
4366 	struct sta_info *sta = container_of(pubsta, struct sta_info, sta);
4367 	struct ieee80211_sub_if_data *sdata = sta->sdata;
4368 
4369 	lockdep_assert_held(&sdata->local->sta_mtx);
4370 
4371 	/* only some cases are supported right now */
4372 	switch (sdata->vif.type) {
4373 	case NL80211_IFTYPE_STATION:
4374 	case NL80211_IFTYPE_AP:
4375 	case NL80211_IFTYPE_AP_VLAN:
4376 		break;
4377 	default:
4378 		WARN_ON(1);
4379 		return;
4380 	}
4381 
4382 	if (tid != sta->reserved_tid) {
4383 		sdata_err(sdata, "TID to unreserve (%d) isn't reserved\n", tid);
4384 		return;
4385 	}
4386 
4387 	sta->reserved_tid = IEEE80211_TID_UNRESERVED;
4388 }
4389 EXPORT_SYMBOL(ieee80211_unreserve_tid);
4390 
4391 void __ieee80211_tx_skb_tid_band(struct ieee80211_sub_if_data *sdata,
4392 				 struct sk_buff *skb, int tid,
4393 				 enum nl80211_band band)
4394 {
4395 	int ac = ieee802_1d_to_ac[tid & 7];
4396 
4397 	skb_reset_mac_header(skb);
4398 	skb_reset_network_header(skb);
4399 	skb_reset_transport_header(skb);
4400 
4401 	skb_set_queue_mapping(skb, ac);
4402 	skb->priority = tid;
4403 
4404 	skb->dev = sdata->dev;
4405 
4406 	/*
4407 	 * The other path calling ieee80211_xmit is from the tasklet,
4408 	 * and while we can handle concurrent transmissions locking
4409 	 * requirements are that we do not come into tx with bhs on.
4410 	 */
4411 	local_bh_disable();
4412 	IEEE80211_SKB_CB(skb)->band = band;
4413 	ieee80211_xmit(sdata, NULL, skb);
4414 	local_bh_enable();
4415 }
4416