xref: /openbmc/linux/net/mac80211/tx.c (revision 95e9fd10)
1 /*
2  * Copyright 2002-2005, Instant802 Networks, Inc.
3  * Copyright 2005-2006, Devicescape Software, Inc.
4  * Copyright 2006-2007	Jiri Benc <jbenc@suse.cz>
5  * Copyright 2007	Johannes Berg <johannes@sipsolutions.net>
6  *
7  * This program is free software; you can redistribute it and/or modify
8  * it under the terms of the GNU General Public License version 2 as
9  * published by the Free Software Foundation.
10  *
11  *
12  * Transmit and frame generation functions.
13  */
14 
15 #include <linux/kernel.h>
16 #include <linux/slab.h>
17 #include <linux/skbuff.h>
18 #include <linux/etherdevice.h>
19 #include <linux/bitmap.h>
20 #include <linux/rcupdate.h>
21 #include <linux/export.h>
22 #include <net/net_namespace.h>
23 #include <net/ieee80211_radiotap.h>
24 #include <net/cfg80211.h>
25 #include <net/mac80211.h>
26 #include <asm/unaligned.h>
27 
28 #include "ieee80211_i.h"
29 #include "driver-ops.h"
30 #include "led.h"
31 #include "mesh.h"
32 #include "wep.h"
33 #include "wpa.h"
34 #include "wme.h"
35 #include "rate.h"
36 
37 /* misc utils */
38 
39 static __le16 ieee80211_duration(struct ieee80211_tx_data *tx,
40 				 struct sk_buff *skb, int group_addr,
41 				 int next_frag_len)
42 {
43 	int rate, mrate, erp, dur, i;
44 	struct ieee80211_rate *txrate;
45 	struct ieee80211_local *local = tx->local;
46 	struct ieee80211_supported_band *sband;
47 	struct ieee80211_hdr *hdr;
48 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
49 
50 	/* assume HW handles this */
51 	if (info->control.rates[0].flags & IEEE80211_TX_RC_MCS)
52 		return 0;
53 
54 	/* uh huh? */
55 	if (WARN_ON_ONCE(info->control.rates[0].idx < 0))
56 		return 0;
57 
58 	sband = local->hw.wiphy->bands[tx->channel->band];
59 	txrate = &sband->bitrates[info->control.rates[0].idx];
60 
61 	erp = txrate->flags & IEEE80211_RATE_ERP_G;
62 
63 	/*
64 	 * data and mgmt (except PS Poll):
65 	 * - during CFP: 32768
66 	 * - during contention period:
67 	 *   if addr1 is group address: 0
68 	 *   if more fragments = 0 and addr1 is individual address: time to
69 	 *      transmit one ACK plus SIFS
70 	 *   if more fragments = 1 and addr1 is individual address: time to
71 	 *      transmit next fragment plus 2 x ACK plus 3 x SIFS
72 	 *
73 	 * IEEE 802.11, 9.6:
74 	 * - control response frame (CTS or ACK) shall be transmitted using the
75 	 *   same rate as the immediately previous frame in the frame exchange
76 	 *   sequence, if this rate belongs to the PHY mandatory rates, or else
77 	 *   at the highest possible rate belonging to the PHY rates in the
78 	 *   BSSBasicRateSet
79 	 */
80 	hdr = (struct ieee80211_hdr *)skb->data;
81 	if (ieee80211_is_ctl(hdr->frame_control)) {
82 		/* TODO: These control frames are not currently sent by
83 		 * mac80211, but should they be implemented, this function
84 		 * needs to be updated to support duration field calculation.
85 		 *
86 		 * RTS: time needed to transmit pending data/mgmt frame plus
87 		 *    one CTS frame plus one ACK frame plus 3 x SIFS
88 		 * CTS: duration of immediately previous RTS minus time
89 		 *    required to transmit CTS and its SIFS
90 		 * ACK: 0 if immediately previous directed data/mgmt had
91 		 *    more=0, with more=1 duration in ACK frame is duration
92 		 *    from previous frame minus time needed to transmit ACK
93 		 *    and its SIFS
94 		 * PS Poll: BIT(15) | BIT(14) | aid
95 		 */
96 		return 0;
97 	}
98 
99 	/* data/mgmt */
100 	if (0 /* FIX: data/mgmt during CFP */)
101 		return cpu_to_le16(32768);
102 
103 	if (group_addr) /* Group address as the destination - no ACK */
104 		return 0;
105 
106 	/* Individual destination address:
107 	 * IEEE 802.11, Ch. 9.6 (after IEEE 802.11g changes)
108 	 * CTS and ACK frames shall be transmitted using the highest rate in
109 	 * basic rate set that is less than or equal to the rate of the
110 	 * immediately previous frame and that is using the same modulation
111 	 * (CCK or OFDM). If no basic rate set matches with these requirements,
112 	 * the highest mandatory rate of the PHY that is less than or equal to
113 	 * the rate of the previous frame is used.
114 	 * Mandatory rates for IEEE 802.11g PHY: 1, 2, 5.5, 11, 6, 12, 24 Mbps
115 	 */
116 	rate = -1;
117 	/* use lowest available if everything fails */
118 	mrate = sband->bitrates[0].bitrate;
119 	for (i = 0; i < sband->n_bitrates; i++) {
120 		struct ieee80211_rate *r = &sband->bitrates[i];
121 
122 		if (r->bitrate > txrate->bitrate)
123 			break;
124 
125 		if (tx->sdata->vif.bss_conf.basic_rates & BIT(i))
126 			rate = r->bitrate;
127 
128 		switch (sband->band) {
129 		case IEEE80211_BAND_2GHZ: {
130 			u32 flag;
131 			if (tx->sdata->flags & IEEE80211_SDATA_OPERATING_GMODE)
132 				flag = IEEE80211_RATE_MANDATORY_G;
133 			else
134 				flag = IEEE80211_RATE_MANDATORY_B;
135 			if (r->flags & flag)
136 				mrate = r->bitrate;
137 			break;
138 		}
139 		case IEEE80211_BAND_5GHZ:
140 			if (r->flags & IEEE80211_RATE_MANDATORY_A)
141 				mrate = r->bitrate;
142 			break;
143 		case IEEE80211_BAND_60GHZ:
144 			/* TODO, for now fall through */
145 		case IEEE80211_NUM_BANDS:
146 			WARN_ON(1);
147 			break;
148 		}
149 	}
150 	if (rate == -1) {
151 		/* No matching basic rate found; use highest suitable mandatory
152 		 * PHY rate */
153 		rate = mrate;
154 	}
155 
156 	/* Don't calculate ACKs for QoS Frames with NoAck Policy set */
157 	if (ieee80211_is_data_qos(hdr->frame_control) &&
158 	    *(ieee80211_get_qos_ctl(hdr)) & IEEE80211_QOS_CTL_ACK_POLICY_NOACK)
159 		dur = 0;
160 	else
161 		/* Time needed to transmit ACK
162 		 * (10 bytes + 4-byte FCS = 112 bits) plus SIFS; rounded up
163 		 * to closest integer */
164 		dur = ieee80211_frame_duration(sband->band, 10, rate, erp,
165 				tx->sdata->vif.bss_conf.use_short_preamble);
166 
167 	if (next_frag_len) {
168 		/* Frame is fragmented: duration increases with time needed to
169 		 * transmit next fragment plus ACK and 2 x SIFS. */
170 		dur *= 2; /* ACK + SIFS */
171 		/* next fragment */
172 		dur += ieee80211_frame_duration(sband->band, next_frag_len,
173 				txrate->bitrate, erp,
174 				tx->sdata->vif.bss_conf.use_short_preamble);
175 	}
176 
177 	return cpu_to_le16(dur);
178 }
179 
180 /* tx handlers */
181 static ieee80211_tx_result debug_noinline
182 ieee80211_tx_h_dynamic_ps(struct ieee80211_tx_data *tx)
183 {
184 	struct ieee80211_local *local = tx->local;
185 	struct ieee80211_if_managed *ifmgd;
186 
187 	/* driver doesn't support power save */
188 	if (!(local->hw.flags & IEEE80211_HW_SUPPORTS_PS))
189 		return TX_CONTINUE;
190 
191 	/* hardware does dynamic power save */
192 	if (local->hw.flags & IEEE80211_HW_SUPPORTS_DYNAMIC_PS)
193 		return TX_CONTINUE;
194 
195 	/* dynamic power save disabled */
196 	if (local->hw.conf.dynamic_ps_timeout <= 0)
197 		return TX_CONTINUE;
198 
199 	/* we are scanning, don't enable power save */
200 	if (local->scanning)
201 		return TX_CONTINUE;
202 
203 	if (!local->ps_sdata)
204 		return TX_CONTINUE;
205 
206 	/* No point if we're going to suspend */
207 	if (local->quiescing)
208 		return TX_CONTINUE;
209 
210 	/* dynamic ps is supported only in managed mode */
211 	if (tx->sdata->vif.type != NL80211_IFTYPE_STATION)
212 		return TX_CONTINUE;
213 
214 	ifmgd = &tx->sdata->u.mgd;
215 
216 	/*
217 	 * Don't wakeup from power save if u-apsd is enabled, voip ac has
218 	 * u-apsd enabled and the frame is in voip class. This effectively
219 	 * means that even if all access categories have u-apsd enabled, in
220 	 * practise u-apsd is only used with the voip ac. This is a
221 	 * workaround for the case when received voip class packets do not
222 	 * have correct qos tag for some reason, due the network or the
223 	 * peer application.
224 	 *
225 	 * Note: ifmgd->uapsd_queues access is racy here. If the value is
226 	 * changed via debugfs, user needs to reassociate manually to have
227 	 * everything in sync.
228 	 */
229 	if ((ifmgd->flags & IEEE80211_STA_UAPSD_ENABLED) &&
230 	    (ifmgd->uapsd_queues & IEEE80211_WMM_IE_STA_QOSINFO_AC_VO) &&
231 	    skb_get_queue_mapping(tx->skb) == IEEE80211_AC_VO)
232 		return TX_CONTINUE;
233 
234 	if (local->hw.conf.flags & IEEE80211_CONF_PS) {
235 		ieee80211_stop_queues_by_reason(&local->hw,
236 						IEEE80211_QUEUE_STOP_REASON_PS);
237 		ifmgd->flags &= ~IEEE80211_STA_NULLFUNC_ACKED;
238 		ieee80211_queue_work(&local->hw,
239 				     &local->dynamic_ps_disable_work);
240 	}
241 
242 	/* Don't restart the timer if we're not disassociated */
243 	if (!ifmgd->associated)
244 		return TX_CONTINUE;
245 
246 	mod_timer(&local->dynamic_ps_timer, jiffies +
247 		  msecs_to_jiffies(local->hw.conf.dynamic_ps_timeout));
248 
249 	return TX_CONTINUE;
250 }
251 
252 static ieee80211_tx_result debug_noinline
253 ieee80211_tx_h_check_assoc(struct ieee80211_tx_data *tx)
254 {
255 
256 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)tx->skb->data;
257 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(tx->skb);
258 	bool assoc = false;
259 
260 	if (unlikely(info->flags & IEEE80211_TX_CTL_INJECTED))
261 		return TX_CONTINUE;
262 
263 	if (unlikely(test_bit(SCAN_SW_SCANNING, &tx->local->scanning)) &&
264 	    test_bit(SDATA_STATE_OFFCHANNEL, &tx->sdata->state) &&
265 	    !ieee80211_is_probe_req(hdr->frame_control) &&
266 	    !ieee80211_is_nullfunc(hdr->frame_control))
267 		/*
268 		 * When software scanning only nullfunc frames (to notify
269 		 * the sleep state to the AP) and probe requests (for the
270 		 * active scan) are allowed, all other frames should not be
271 		 * sent and we should not get here, but if we do
272 		 * nonetheless, drop them to avoid sending them
273 		 * off-channel. See the link below and
274 		 * ieee80211_start_scan() for more.
275 		 *
276 		 * http://article.gmane.org/gmane.linux.kernel.wireless.general/30089
277 		 */
278 		return TX_DROP;
279 
280 	if (tx->sdata->vif.type == NL80211_IFTYPE_WDS)
281 		return TX_CONTINUE;
282 
283 	if (tx->sdata->vif.type == NL80211_IFTYPE_MESH_POINT)
284 		return TX_CONTINUE;
285 
286 	if (tx->flags & IEEE80211_TX_PS_BUFFERED)
287 		return TX_CONTINUE;
288 
289 	if (tx->sta)
290 		assoc = test_sta_flag(tx->sta, WLAN_STA_ASSOC);
291 
292 	if (likely(tx->flags & IEEE80211_TX_UNICAST)) {
293 		if (unlikely(!assoc &&
294 			     ieee80211_is_data(hdr->frame_control))) {
295 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG
296 			sdata_info(tx->sdata,
297 				   "dropped data frame to not associated station %pM\n",
298 				   hdr->addr1);
299 #endif
300 			I802_DEBUG_INC(tx->local->tx_handlers_drop_not_assoc);
301 			return TX_DROP;
302 		}
303 	} else if (unlikely(tx->sdata->vif.type == NL80211_IFTYPE_AP &&
304 			    ieee80211_is_data(hdr->frame_control) &&
305 			    !atomic_read(&tx->sdata->u.ap.num_mcast_sta))) {
306 		/*
307 		 * No associated STAs - no need to send multicast
308 		 * frames.
309 		 */
310 		return TX_DROP;
311 	}
312 
313 	return TX_CONTINUE;
314 }
315 
316 /* This function is called whenever the AP is about to exceed the maximum limit
317  * of buffered frames for power saving STAs. This situation should not really
318  * happen often during normal operation, so dropping the oldest buffered packet
319  * from each queue should be OK to make some room for new frames. */
320 static void purge_old_ps_buffers(struct ieee80211_local *local)
321 {
322 	int total = 0, purged = 0;
323 	struct sk_buff *skb;
324 	struct ieee80211_sub_if_data *sdata;
325 	struct sta_info *sta;
326 
327 	/*
328 	 * virtual interfaces are protected by RCU
329 	 */
330 	rcu_read_lock();
331 
332 	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
333 		struct ieee80211_if_ap *ap;
334 		if (sdata->vif.type != NL80211_IFTYPE_AP)
335 			continue;
336 		ap = &sdata->u.ap;
337 		skb = skb_dequeue(&ap->ps_bc_buf);
338 		if (skb) {
339 			purged++;
340 			dev_kfree_skb(skb);
341 		}
342 		total += skb_queue_len(&ap->ps_bc_buf);
343 	}
344 
345 	/*
346 	 * Drop one frame from each station from the lowest-priority
347 	 * AC that has frames at all.
348 	 */
349 	list_for_each_entry_rcu(sta, &local->sta_list, list) {
350 		int ac;
351 
352 		for (ac = IEEE80211_AC_BK; ac >= IEEE80211_AC_VO; ac--) {
353 			skb = skb_dequeue(&sta->ps_tx_buf[ac]);
354 			total += skb_queue_len(&sta->ps_tx_buf[ac]);
355 			if (skb) {
356 				purged++;
357 				dev_kfree_skb(skb);
358 				break;
359 			}
360 		}
361 	}
362 
363 	rcu_read_unlock();
364 
365 	local->total_ps_buffered = total;
366 	ps_dbg_hw(&local->hw, "PS buffers full - purged %d frames\n", purged);
367 }
368 
369 static ieee80211_tx_result
370 ieee80211_tx_h_multicast_ps_buf(struct ieee80211_tx_data *tx)
371 {
372 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(tx->skb);
373 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)tx->skb->data;
374 
375 	/*
376 	 * broadcast/multicast frame
377 	 *
378 	 * If any of the associated stations is in power save mode,
379 	 * the frame is buffered to be sent after DTIM beacon frame.
380 	 * This is done either by the hardware or us.
381 	 */
382 
383 	/* powersaving STAs only in AP/VLAN mode */
384 	if (!tx->sdata->bss)
385 		return TX_CONTINUE;
386 
387 	/* no buffering for ordered frames */
388 	if (ieee80211_has_order(hdr->frame_control))
389 		return TX_CONTINUE;
390 
391 	/* no stations in PS mode */
392 	if (!atomic_read(&tx->sdata->bss->num_sta_ps))
393 		return TX_CONTINUE;
394 
395 	info->flags |= IEEE80211_TX_CTL_SEND_AFTER_DTIM;
396 	if (tx->local->hw.flags & IEEE80211_HW_QUEUE_CONTROL)
397 		info->hw_queue = tx->sdata->vif.cab_queue;
398 
399 	/* device releases frame after DTIM beacon */
400 	if (!(tx->local->hw.flags & IEEE80211_HW_HOST_BROADCAST_PS_BUFFERING))
401 		return TX_CONTINUE;
402 
403 	/* buffered in mac80211 */
404 	if (tx->local->total_ps_buffered >= TOTAL_MAX_TX_BUFFER)
405 		purge_old_ps_buffers(tx->local);
406 
407 	if (skb_queue_len(&tx->sdata->bss->ps_bc_buf) >= AP_MAX_BC_BUFFER) {
408 		ps_dbg(tx->sdata,
409 		       "BC TX buffer full - dropping the oldest frame\n");
410 		dev_kfree_skb(skb_dequeue(&tx->sdata->bss->ps_bc_buf));
411 	} else
412 		tx->local->total_ps_buffered++;
413 
414 	skb_queue_tail(&tx->sdata->bss->ps_bc_buf, tx->skb);
415 
416 	return TX_QUEUED;
417 }
418 
419 static int ieee80211_use_mfp(__le16 fc, struct sta_info *sta,
420 			     struct sk_buff *skb)
421 {
422 	if (!ieee80211_is_mgmt(fc))
423 		return 0;
424 
425 	if (sta == NULL || !test_sta_flag(sta, WLAN_STA_MFP))
426 		return 0;
427 
428 	if (!ieee80211_is_robust_mgmt_frame((struct ieee80211_hdr *)
429 					    skb->data))
430 		return 0;
431 
432 	return 1;
433 }
434 
435 static ieee80211_tx_result
436 ieee80211_tx_h_unicast_ps_buf(struct ieee80211_tx_data *tx)
437 {
438 	struct sta_info *sta = tx->sta;
439 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(tx->skb);
440 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)tx->skb->data;
441 	struct ieee80211_local *local = tx->local;
442 
443 	if (unlikely(!sta))
444 		return TX_CONTINUE;
445 
446 	if (unlikely((test_sta_flag(sta, WLAN_STA_PS_STA) ||
447 		      test_sta_flag(sta, WLAN_STA_PS_DRIVER)) &&
448 		     !(info->flags & IEEE80211_TX_CTL_NO_PS_BUFFER))) {
449 		int ac = skb_get_queue_mapping(tx->skb);
450 
451 		/* only deauth, disassoc and action are bufferable MMPDUs */
452 		if (ieee80211_is_mgmt(hdr->frame_control) &&
453 		    !ieee80211_is_deauth(hdr->frame_control) &&
454 		    !ieee80211_is_disassoc(hdr->frame_control) &&
455 		    !ieee80211_is_action(hdr->frame_control)) {
456 			info->flags |= IEEE80211_TX_CTL_NO_PS_BUFFER;
457 			return TX_CONTINUE;
458 		}
459 
460 		ps_dbg(sta->sdata, "STA %pM aid %d: PS buffer for AC %d\n",
461 		       sta->sta.addr, sta->sta.aid, ac);
462 		if (tx->local->total_ps_buffered >= TOTAL_MAX_TX_BUFFER)
463 			purge_old_ps_buffers(tx->local);
464 		if (skb_queue_len(&sta->ps_tx_buf[ac]) >= STA_MAX_TX_BUFFER) {
465 			struct sk_buff *old = skb_dequeue(&sta->ps_tx_buf[ac]);
466 			ps_dbg(tx->sdata,
467 			       "STA %pM TX buffer for AC %d full - dropping oldest frame\n",
468 			       sta->sta.addr, ac);
469 			dev_kfree_skb(old);
470 		} else
471 			tx->local->total_ps_buffered++;
472 
473 		info->control.jiffies = jiffies;
474 		info->control.vif = &tx->sdata->vif;
475 		info->flags |= IEEE80211_TX_INTFL_NEED_TXPROCESSING;
476 		skb_queue_tail(&sta->ps_tx_buf[ac], tx->skb);
477 
478 		if (!timer_pending(&local->sta_cleanup))
479 			mod_timer(&local->sta_cleanup,
480 				  round_jiffies(jiffies +
481 						STA_INFO_CLEANUP_INTERVAL));
482 
483 		/*
484 		 * We queued up some frames, so the TIM bit might
485 		 * need to be set, recalculate it.
486 		 */
487 		sta_info_recalc_tim(sta);
488 
489 		return TX_QUEUED;
490 	} else if (unlikely(test_sta_flag(sta, WLAN_STA_PS_STA))) {
491 		ps_dbg(tx->sdata,
492 		       "STA %pM in PS mode, but polling/in SP -> send frame\n",
493 		       sta->sta.addr);
494 	}
495 
496 	return TX_CONTINUE;
497 }
498 
499 static ieee80211_tx_result debug_noinline
500 ieee80211_tx_h_ps_buf(struct ieee80211_tx_data *tx)
501 {
502 	if (unlikely(tx->flags & IEEE80211_TX_PS_BUFFERED))
503 		return TX_CONTINUE;
504 
505 	if (tx->flags & IEEE80211_TX_UNICAST)
506 		return ieee80211_tx_h_unicast_ps_buf(tx);
507 	else
508 		return ieee80211_tx_h_multicast_ps_buf(tx);
509 }
510 
511 static ieee80211_tx_result debug_noinline
512 ieee80211_tx_h_check_control_port_protocol(struct ieee80211_tx_data *tx)
513 {
514 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(tx->skb);
515 
516 	if (unlikely(tx->sdata->control_port_protocol == tx->skb->protocol &&
517 		     tx->sdata->control_port_no_encrypt))
518 		info->flags |= IEEE80211_TX_INTFL_DONT_ENCRYPT;
519 
520 	return TX_CONTINUE;
521 }
522 
523 static ieee80211_tx_result debug_noinline
524 ieee80211_tx_h_select_key(struct ieee80211_tx_data *tx)
525 {
526 	struct ieee80211_key *key;
527 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(tx->skb);
528 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)tx->skb->data;
529 
530 	if (unlikely(info->flags & IEEE80211_TX_INTFL_DONT_ENCRYPT))
531 		tx->key = NULL;
532 	else if (tx->sta && (key = rcu_dereference(tx->sta->ptk)))
533 		tx->key = key;
534 	else if (ieee80211_is_mgmt(hdr->frame_control) &&
535 		 is_multicast_ether_addr(hdr->addr1) &&
536 		 ieee80211_is_robust_mgmt_frame(hdr) &&
537 		 (key = rcu_dereference(tx->sdata->default_mgmt_key)))
538 		tx->key = key;
539 	else if (is_multicast_ether_addr(hdr->addr1) &&
540 		 (key = rcu_dereference(tx->sdata->default_multicast_key)))
541 		tx->key = key;
542 	else if (!is_multicast_ether_addr(hdr->addr1) &&
543 		 (key = rcu_dereference(tx->sdata->default_unicast_key)))
544 		tx->key = key;
545 	else if (info->flags & IEEE80211_TX_CTL_INJECTED)
546 		tx->key = NULL;
547 	else if (!tx->sdata->drop_unencrypted)
548 		tx->key = NULL;
549 	else if (tx->skb->protocol == tx->sdata->control_port_protocol)
550 		tx->key = NULL;
551 	else if (ieee80211_is_robust_mgmt_frame(hdr) &&
552 		 !(ieee80211_is_action(hdr->frame_control) &&
553 		   tx->sta && test_sta_flag(tx->sta, WLAN_STA_MFP)))
554 		tx->key = NULL;
555 	else if (ieee80211_is_mgmt(hdr->frame_control) &&
556 		 !ieee80211_is_robust_mgmt_frame(hdr))
557 		tx->key = NULL;
558 	else {
559 		I802_DEBUG_INC(tx->local->tx_handlers_drop_unencrypted);
560 		return TX_DROP;
561 	}
562 
563 	if (tx->key) {
564 		bool skip_hw = false;
565 
566 		tx->key->tx_rx_count++;
567 		/* TODO: add threshold stuff again */
568 
569 		switch (tx->key->conf.cipher) {
570 		case WLAN_CIPHER_SUITE_WEP40:
571 		case WLAN_CIPHER_SUITE_WEP104:
572 		case WLAN_CIPHER_SUITE_TKIP:
573 			if (!ieee80211_is_data_present(hdr->frame_control))
574 				tx->key = NULL;
575 			break;
576 		case WLAN_CIPHER_SUITE_CCMP:
577 			if (!ieee80211_is_data_present(hdr->frame_control) &&
578 			    !ieee80211_use_mfp(hdr->frame_control, tx->sta,
579 					       tx->skb))
580 				tx->key = NULL;
581 			else
582 				skip_hw = (tx->key->conf.flags &
583 					   IEEE80211_KEY_FLAG_SW_MGMT) &&
584 					ieee80211_is_mgmt(hdr->frame_control);
585 			break;
586 		case WLAN_CIPHER_SUITE_AES_CMAC:
587 			if (!ieee80211_is_mgmt(hdr->frame_control))
588 				tx->key = NULL;
589 			break;
590 		}
591 
592 		if (unlikely(tx->key && tx->key->flags & KEY_FLAG_TAINTED))
593 			return TX_DROP;
594 
595 		if (!skip_hw && tx->key &&
596 		    tx->key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE)
597 			info->control.hw_key = &tx->key->conf;
598 	}
599 
600 	return TX_CONTINUE;
601 }
602 
603 static ieee80211_tx_result debug_noinline
604 ieee80211_tx_h_rate_ctrl(struct ieee80211_tx_data *tx)
605 {
606 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(tx->skb);
607 	struct ieee80211_hdr *hdr = (void *)tx->skb->data;
608 	struct ieee80211_supported_band *sband;
609 	struct ieee80211_rate *rate;
610 	int i;
611 	u32 len;
612 	bool inval = false, rts = false, short_preamble = false;
613 	struct ieee80211_tx_rate_control txrc;
614 	bool assoc = false;
615 
616 	memset(&txrc, 0, sizeof(txrc));
617 
618 	sband = tx->local->hw.wiphy->bands[tx->channel->band];
619 
620 	len = min_t(u32, tx->skb->len + FCS_LEN,
621 			 tx->local->hw.wiphy->frag_threshold);
622 
623 	/* set up the tx rate control struct we give the RC algo */
624 	txrc.hw = &tx->local->hw;
625 	txrc.sband = sband;
626 	txrc.bss_conf = &tx->sdata->vif.bss_conf;
627 	txrc.skb = tx->skb;
628 	txrc.reported_rate.idx = -1;
629 	txrc.rate_idx_mask = tx->sdata->rc_rateidx_mask[tx->channel->band];
630 	if (txrc.rate_idx_mask == (1 << sband->n_bitrates) - 1)
631 		txrc.max_rate_idx = -1;
632 	else
633 		txrc.max_rate_idx = fls(txrc.rate_idx_mask) - 1;
634 	memcpy(txrc.rate_idx_mcs_mask,
635 	       tx->sdata->rc_rateidx_mcs_mask[tx->channel->band],
636 	       sizeof(txrc.rate_idx_mcs_mask));
637 	txrc.bss = (tx->sdata->vif.type == NL80211_IFTYPE_AP ||
638 		    tx->sdata->vif.type == NL80211_IFTYPE_MESH_POINT ||
639 		    tx->sdata->vif.type == NL80211_IFTYPE_ADHOC);
640 
641 	/* set up RTS protection if desired */
642 	if (len > tx->local->hw.wiphy->rts_threshold) {
643 		txrc.rts = rts = true;
644 	}
645 
646 	/*
647 	 * Use short preamble if the BSS can handle it, but not for
648 	 * management frames unless we know the receiver can handle
649 	 * that -- the management frame might be to a station that
650 	 * just wants a probe response.
651 	 */
652 	if (tx->sdata->vif.bss_conf.use_short_preamble &&
653 	    (ieee80211_is_data(hdr->frame_control) ||
654 	     (tx->sta && test_sta_flag(tx->sta, WLAN_STA_SHORT_PREAMBLE))))
655 		txrc.short_preamble = short_preamble = true;
656 
657 	if (tx->sta)
658 		assoc = test_sta_flag(tx->sta, WLAN_STA_ASSOC);
659 
660 	/*
661 	 * Lets not bother rate control if we're associated and cannot
662 	 * talk to the sta. This should not happen.
663 	 */
664 	if (WARN(test_bit(SCAN_SW_SCANNING, &tx->local->scanning) && assoc &&
665 		 !rate_usable_index_exists(sband, &tx->sta->sta),
666 		 "%s: Dropped data frame as no usable bitrate found while "
667 		 "scanning and associated. Target station: "
668 		 "%pM on %d GHz band\n",
669 		 tx->sdata->name, hdr->addr1,
670 		 tx->channel->band ? 5 : 2))
671 		return TX_DROP;
672 
673 	/*
674 	 * If we're associated with the sta at this point we know we can at
675 	 * least send the frame at the lowest bit rate.
676 	 */
677 	rate_control_get_rate(tx->sdata, tx->sta, &txrc);
678 
679 	if (unlikely(info->control.rates[0].idx < 0))
680 		return TX_DROP;
681 
682 	if (txrc.reported_rate.idx < 0) {
683 		txrc.reported_rate = info->control.rates[0];
684 		if (tx->sta && ieee80211_is_data(hdr->frame_control))
685 			tx->sta->last_tx_rate = txrc.reported_rate;
686 	} else if (tx->sta)
687 		tx->sta->last_tx_rate = txrc.reported_rate;
688 
689 	if (unlikely(!info->control.rates[0].count))
690 		info->control.rates[0].count = 1;
691 
692 	if (WARN_ON_ONCE((info->control.rates[0].count > 1) &&
693 			 (info->flags & IEEE80211_TX_CTL_NO_ACK)))
694 		info->control.rates[0].count = 1;
695 
696 	if (is_multicast_ether_addr(hdr->addr1)) {
697 		/*
698 		 * XXX: verify the rate is in the basic rateset
699 		 */
700 		return TX_CONTINUE;
701 	}
702 
703 	/*
704 	 * set up the RTS/CTS rate as the fastest basic rate
705 	 * that is not faster than the data rate
706 	 *
707 	 * XXX: Should this check all retry rates?
708 	 */
709 	if (!(info->control.rates[0].flags & IEEE80211_TX_RC_MCS)) {
710 		s8 baserate = 0;
711 
712 		rate = &sband->bitrates[info->control.rates[0].idx];
713 
714 		for (i = 0; i < sband->n_bitrates; i++) {
715 			/* must be a basic rate */
716 			if (!(tx->sdata->vif.bss_conf.basic_rates & BIT(i)))
717 				continue;
718 			/* must not be faster than the data rate */
719 			if (sband->bitrates[i].bitrate > rate->bitrate)
720 				continue;
721 			/* maximum */
722 			if (sband->bitrates[baserate].bitrate <
723 			     sband->bitrates[i].bitrate)
724 				baserate = i;
725 		}
726 
727 		info->control.rts_cts_rate_idx = baserate;
728 	}
729 
730 	for (i = 0; i < IEEE80211_TX_MAX_RATES; i++) {
731 		/*
732 		 * make sure there's no valid rate following
733 		 * an invalid one, just in case drivers don't
734 		 * take the API seriously to stop at -1.
735 		 */
736 		if (inval) {
737 			info->control.rates[i].idx = -1;
738 			continue;
739 		}
740 		if (info->control.rates[i].idx < 0) {
741 			inval = true;
742 			continue;
743 		}
744 
745 		/*
746 		 * For now assume MCS is already set up correctly, this
747 		 * needs to be fixed.
748 		 */
749 		if (info->control.rates[i].flags & IEEE80211_TX_RC_MCS) {
750 			WARN_ON(info->control.rates[i].idx > 76);
751 			continue;
752 		}
753 
754 		/* set up RTS protection if desired */
755 		if (rts)
756 			info->control.rates[i].flags |=
757 				IEEE80211_TX_RC_USE_RTS_CTS;
758 
759 		/* RC is busted */
760 		if (WARN_ON_ONCE(info->control.rates[i].idx >=
761 				 sband->n_bitrates)) {
762 			info->control.rates[i].idx = -1;
763 			continue;
764 		}
765 
766 		rate = &sband->bitrates[info->control.rates[i].idx];
767 
768 		/* set up short preamble */
769 		if (short_preamble &&
770 		    rate->flags & IEEE80211_RATE_SHORT_PREAMBLE)
771 			info->control.rates[i].flags |=
772 				IEEE80211_TX_RC_USE_SHORT_PREAMBLE;
773 
774 		/* set up G protection */
775 		if (!rts && tx->sdata->vif.bss_conf.use_cts_prot &&
776 		    rate->flags & IEEE80211_RATE_ERP_G)
777 			info->control.rates[i].flags |=
778 				IEEE80211_TX_RC_USE_CTS_PROTECT;
779 	}
780 
781 	return TX_CONTINUE;
782 }
783 
784 static ieee80211_tx_result debug_noinline
785 ieee80211_tx_h_sequence(struct ieee80211_tx_data *tx)
786 {
787 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(tx->skb);
788 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)tx->skb->data;
789 	u16 *seq;
790 	u8 *qc;
791 	int tid;
792 
793 	/*
794 	 * Packet injection may want to control the sequence
795 	 * number, if we have no matching interface then we
796 	 * neither assign one ourselves nor ask the driver to.
797 	 */
798 	if (unlikely(info->control.vif->type == NL80211_IFTYPE_MONITOR))
799 		return TX_CONTINUE;
800 
801 	if (unlikely(ieee80211_is_ctl(hdr->frame_control)))
802 		return TX_CONTINUE;
803 
804 	if (ieee80211_hdrlen(hdr->frame_control) < 24)
805 		return TX_CONTINUE;
806 
807 	if (ieee80211_is_qos_nullfunc(hdr->frame_control))
808 		return TX_CONTINUE;
809 
810 	/*
811 	 * Anything but QoS data that has a sequence number field
812 	 * (is long enough) gets a sequence number from the global
813 	 * counter.
814 	 */
815 	if (!ieee80211_is_data_qos(hdr->frame_control)) {
816 		/* driver should assign sequence number */
817 		info->flags |= IEEE80211_TX_CTL_ASSIGN_SEQ;
818 		/* for pure STA mode without beacons, we can do it */
819 		hdr->seq_ctrl = cpu_to_le16(tx->sdata->sequence_number);
820 		tx->sdata->sequence_number += 0x10;
821 		return TX_CONTINUE;
822 	}
823 
824 	/*
825 	 * This should be true for injected/management frames only, for
826 	 * management frames we have set the IEEE80211_TX_CTL_ASSIGN_SEQ
827 	 * above since they are not QoS-data frames.
828 	 */
829 	if (!tx->sta)
830 		return TX_CONTINUE;
831 
832 	/* include per-STA, per-TID sequence counter */
833 
834 	qc = ieee80211_get_qos_ctl(hdr);
835 	tid = *qc & IEEE80211_QOS_CTL_TID_MASK;
836 	seq = &tx->sta->tid_seq[tid];
837 
838 	hdr->seq_ctrl = cpu_to_le16(*seq);
839 
840 	/* Increase the sequence number. */
841 	*seq = (*seq + 0x10) & IEEE80211_SCTL_SEQ;
842 
843 	return TX_CONTINUE;
844 }
845 
846 static int ieee80211_fragment(struct ieee80211_tx_data *tx,
847 			      struct sk_buff *skb, int hdrlen,
848 			      int frag_threshold)
849 {
850 	struct ieee80211_local *local = tx->local;
851 	struct ieee80211_tx_info *info;
852 	struct sk_buff *tmp;
853 	int per_fragm = frag_threshold - hdrlen - FCS_LEN;
854 	int pos = hdrlen + per_fragm;
855 	int rem = skb->len - hdrlen - per_fragm;
856 
857 	if (WARN_ON(rem < 0))
858 		return -EINVAL;
859 
860 	/* first fragment was already added to queue by caller */
861 
862 	while (rem) {
863 		int fraglen = per_fragm;
864 
865 		if (fraglen > rem)
866 			fraglen = rem;
867 		rem -= fraglen;
868 		tmp = dev_alloc_skb(local->tx_headroom +
869 				    frag_threshold +
870 				    IEEE80211_ENCRYPT_HEADROOM +
871 				    IEEE80211_ENCRYPT_TAILROOM);
872 		if (!tmp)
873 			return -ENOMEM;
874 
875 		__skb_queue_tail(&tx->skbs, tmp);
876 
877 		skb_reserve(tmp, local->tx_headroom +
878 				 IEEE80211_ENCRYPT_HEADROOM);
879 		/* copy control information */
880 		memcpy(tmp->cb, skb->cb, sizeof(tmp->cb));
881 
882 		info = IEEE80211_SKB_CB(tmp);
883 		info->flags &= ~(IEEE80211_TX_CTL_CLEAR_PS_FILT |
884 				 IEEE80211_TX_CTL_FIRST_FRAGMENT);
885 
886 		if (rem)
887 			info->flags |= IEEE80211_TX_CTL_MORE_FRAMES;
888 
889 		skb_copy_queue_mapping(tmp, skb);
890 		tmp->priority = skb->priority;
891 		tmp->dev = skb->dev;
892 
893 		/* copy header and data */
894 		memcpy(skb_put(tmp, hdrlen), skb->data, hdrlen);
895 		memcpy(skb_put(tmp, fraglen), skb->data + pos, fraglen);
896 
897 		pos += fraglen;
898 	}
899 
900 	/* adjust first fragment's length */
901 	skb->len = hdrlen + per_fragm;
902 	return 0;
903 }
904 
905 static ieee80211_tx_result debug_noinline
906 ieee80211_tx_h_fragment(struct ieee80211_tx_data *tx)
907 {
908 	struct sk_buff *skb = tx->skb;
909 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
910 	struct ieee80211_hdr *hdr = (void *)skb->data;
911 	int frag_threshold = tx->local->hw.wiphy->frag_threshold;
912 	int hdrlen;
913 	int fragnum;
914 
915 	/* no matter what happens, tx->skb moves to tx->skbs */
916 	__skb_queue_tail(&tx->skbs, skb);
917 	tx->skb = NULL;
918 
919 	if (info->flags & IEEE80211_TX_CTL_DONTFRAG)
920 		return TX_CONTINUE;
921 
922 	if (tx->local->ops->set_frag_threshold)
923 		return TX_CONTINUE;
924 
925 	/*
926 	 * Warn when submitting a fragmented A-MPDU frame and drop it.
927 	 * This scenario is handled in ieee80211_tx_prepare but extra
928 	 * caution taken here as fragmented ampdu may cause Tx stop.
929 	 */
930 	if (WARN_ON(info->flags & IEEE80211_TX_CTL_AMPDU))
931 		return TX_DROP;
932 
933 	hdrlen = ieee80211_hdrlen(hdr->frame_control);
934 
935 	/* internal error, why isn't DONTFRAG set? */
936 	if (WARN_ON(skb->len + FCS_LEN <= frag_threshold))
937 		return TX_DROP;
938 
939 	/*
940 	 * Now fragment the frame. This will allocate all the fragments and
941 	 * chain them (using skb as the first fragment) to skb->next.
942 	 * During transmission, we will remove the successfully transmitted
943 	 * fragments from this list. When the low-level driver rejects one
944 	 * of the fragments then we will simply pretend to accept the skb
945 	 * but store it away as pending.
946 	 */
947 	if (ieee80211_fragment(tx, skb, hdrlen, frag_threshold))
948 		return TX_DROP;
949 
950 	/* update duration/seq/flags of fragments */
951 	fragnum = 0;
952 
953 	skb_queue_walk(&tx->skbs, skb) {
954 		int next_len;
955 		const __le16 morefrags = cpu_to_le16(IEEE80211_FCTL_MOREFRAGS);
956 
957 		hdr = (void *)skb->data;
958 		info = IEEE80211_SKB_CB(skb);
959 
960 		if (!skb_queue_is_last(&tx->skbs, skb)) {
961 			hdr->frame_control |= morefrags;
962 			/*
963 			 * No multi-rate retries for fragmented frames, that
964 			 * would completely throw off the NAV at other STAs.
965 			 */
966 			info->control.rates[1].idx = -1;
967 			info->control.rates[2].idx = -1;
968 			info->control.rates[3].idx = -1;
969 			BUILD_BUG_ON(IEEE80211_TX_MAX_RATES != 4);
970 			info->flags &= ~IEEE80211_TX_CTL_RATE_CTRL_PROBE;
971 		} else {
972 			hdr->frame_control &= ~morefrags;
973 			next_len = 0;
974 		}
975 		hdr->seq_ctrl |= cpu_to_le16(fragnum & IEEE80211_SCTL_FRAG);
976 		fragnum++;
977 	}
978 
979 	return TX_CONTINUE;
980 }
981 
982 static ieee80211_tx_result debug_noinline
983 ieee80211_tx_h_stats(struct ieee80211_tx_data *tx)
984 {
985 	struct sk_buff *skb;
986 
987 	if (!tx->sta)
988 		return TX_CONTINUE;
989 
990 	tx->sta->tx_packets++;
991 	skb_queue_walk(&tx->skbs, skb) {
992 		tx->sta->tx_fragments++;
993 		tx->sta->tx_bytes += skb->len;
994 	}
995 
996 	return TX_CONTINUE;
997 }
998 
999 static ieee80211_tx_result debug_noinline
1000 ieee80211_tx_h_encrypt(struct ieee80211_tx_data *tx)
1001 {
1002 	if (!tx->key)
1003 		return TX_CONTINUE;
1004 
1005 	switch (tx->key->conf.cipher) {
1006 	case WLAN_CIPHER_SUITE_WEP40:
1007 	case WLAN_CIPHER_SUITE_WEP104:
1008 		return ieee80211_crypto_wep_encrypt(tx);
1009 	case WLAN_CIPHER_SUITE_TKIP:
1010 		return ieee80211_crypto_tkip_encrypt(tx);
1011 	case WLAN_CIPHER_SUITE_CCMP:
1012 		return ieee80211_crypto_ccmp_encrypt(tx);
1013 	case WLAN_CIPHER_SUITE_AES_CMAC:
1014 		return ieee80211_crypto_aes_cmac_encrypt(tx);
1015 	default:
1016 		return ieee80211_crypto_hw_encrypt(tx);
1017 	}
1018 
1019 	return TX_DROP;
1020 }
1021 
1022 static ieee80211_tx_result debug_noinline
1023 ieee80211_tx_h_calculate_duration(struct ieee80211_tx_data *tx)
1024 {
1025 	struct sk_buff *skb;
1026 	struct ieee80211_hdr *hdr;
1027 	int next_len;
1028 	bool group_addr;
1029 
1030 	skb_queue_walk(&tx->skbs, skb) {
1031 		hdr = (void *) skb->data;
1032 		if (unlikely(ieee80211_is_pspoll(hdr->frame_control)))
1033 			break; /* must not overwrite AID */
1034 		if (!skb_queue_is_last(&tx->skbs, skb)) {
1035 			struct sk_buff *next = skb_queue_next(&tx->skbs, skb);
1036 			next_len = next->len;
1037 		} else
1038 			next_len = 0;
1039 		group_addr = is_multicast_ether_addr(hdr->addr1);
1040 
1041 		hdr->duration_id =
1042 			ieee80211_duration(tx, skb, group_addr, next_len);
1043 	}
1044 
1045 	return TX_CONTINUE;
1046 }
1047 
1048 /* actual transmit path */
1049 
1050 static bool ieee80211_tx_prep_agg(struct ieee80211_tx_data *tx,
1051 				  struct sk_buff *skb,
1052 				  struct ieee80211_tx_info *info,
1053 				  struct tid_ampdu_tx *tid_tx,
1054 				  int tid)
1055 {
1056 	bool queued = false;
1057 	bool reset_agg_timer = false;
1058 	struct sk_buff *purge_skb = NULL;
1059 
1060 	if (test_bit(HT_AGG_STATE_OPERATIONAL, &tid_tx->state)) {
1061 		info->flags |= IEEE80211_TX_CTL_AMPDU;
1062 		reset_agg_timer = true;
1063 	} else if (test_bit(HT_AGG_STATE_WANT_START, &tid_tx->state)) {
1064 		/*
1065 		 * nothing -- this aggregation session is being started
1066 		 * but that might still fail with the driver
1067 		 */
1068 	} else {
1069 		spin_lock(&tx->sta->lock);
1070 		/*
1071 		 * Need to re-check now, because we may get here
1072 		 *
1073 		 *  1) in the window during which the setup is actually
1074 		 *     already done, but not marked yet because not all
1075 		 *     packets are spliced over to the driver pending
1076 		 *     queue yet -- if this happened we acquire the lock
1077 		 *     either before or after the splice happens, but
1078 		 *     need to recheck which of these cases happened.
1079 		 *
1080 		 *  2) during session teardown, if the OPERATIONAL bit
1081 		 *     was cleared due to the teardown but the pointer
1082 		 *     hasn't been assigned NULL yet (or we loaded it
1083 		 *     before it was assigned) -- in this case it may
1084 		 *     now be NULL which means we should just let the
1085 		 *     packet pass through because splicing the frames
1086 		 *     back is already done.
1087 		 */
1088 		tid_tx = rcu_dereference_protected_tid_tx(tx->sta, tid);
1089 
1090 		if (!tid_tx) {
1091 			/* do nothing, let packet pass through */
1092 		} else if (test_bit(HT_AGG_STATE_OPERATIONAL, &tid_tx->state)) {
1093 			info->flags |= IEEE80211_TX_CTL_AMPDU;
1094 			reset_agg_timer = true;
1095 		} else {
1096 			queued = true;
1097 			info->control.vif = &tx->sdata->vif;
1098 			info->flags |= IEEE80211_TX_INTFL_NEED_TXPROCESSING;
1099 			__skb_queue_tail(&tid_tx->pending, skb);
1100 			if (skb_queue_len(&tid_tx->pending) > STA_MAX_TX_BUFFER)
1101 				purge_skb = __skb_dequeue(&tid_tx->pending);
1102 		}
1103 		spin_unlock(&tx->sta->lock);
1104 
1105 		if (purge_skb)
1106 			dev_kfree_skb(purge_skb);
1107 	}
1108 
1109 	/* reset session timer */
1110 	if (reset_agg_timer && tid_tx->timeout)
1111 		tid_tx->last_tx = jiffies;
1112 
1113 	return queued;
1114 }
1115 
1116 /*
1117  * initialises @tx
1118  */
1119 static ieee80211_tx_result
1120 ieee80211_tx_prepare(struct ieee80211_sub_if_data *sdata,
1121 		     struct ieee80211_tx_data *tx,
1122 		     struct sk_buff *skb)
1123 {
1124 	struct ieee80211_local *local = sdata->local;
1125 	struct ieee80211_hdr *hdr;
1126 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
1127 	int tid;
1128 	u8 *qc;
1129 
1130 	memset(tx, 0, sizeof(*tx));
1131 	tx->skb = skb;
1132 	tx->local = local;
1133 	tx->sdata = sdata;
1134 	tx->channel = local->hw.conf.channel;
1135 	__skb_queue_head_init(&tx->skbs);
1136 
1137 	/*
1138 	 * If this flag is set to true anywhere, and we get here,
1139 	 * we are doing the needed processing, so remove the flag
1140 	 * now.
1141 	 */
1142 	info->flags &= ~IEEE80211_TX_INTFL_NEED_TXPROCESSING;
1143 
1144 	hdr = (struct ieee80211_hdr *) skb->data;
1145 
1146 	if (sdata->vif.type == NL80211_IFTYPE_AP_VLAN) {
1147 		tx->sta = rcu_dereference(sdata->u.vlan.sta);
1148 		if (!tx->sta && sdata->dev->ieee80211_ptr->use_4addr)
1149 			return TX_DROP;
1150 	} else if (info->flags & IEEE80211_TX_CTL_INJECTED ||
1151 		   tx->sdata->control_port_protocol == tx->skb->protocol) {
1152 		tx->sta = sta_info_get_bss(sdata, hdr->addr1);
1153 	}
1154 	if (!tx->sta)
1155 		tx->sta = sta_info_get(sdata, hdr->addr1);
1156 
1157 	if (tx->sta && ieee80211_is_data_qos(hdr->frame_control) &&
1158 	    !ieee80211_is_qos_nullfunc(hdr->frame_control) &&
1159 	    (local->hw.flags & IEEE80211_HW_AMPDU_AGGREGATION) &&
1160 	    !(local->hw.flags & IEEE80211_HW_TX_AMPDU_SETUP_IN_HW)) {
1161 		struct tid_ampdu_tx *tid_tx;
1162 
1163 		qc = ieee80211_get_qos_ctl(hdr);
1164 		tid = *qc & IEEE80211_QOS_CTL_TID_MASK;
1165 
1166 		tid_tx = rcu_dereference(tx->sta->ampdu_mlme.tid_tx[tid]);
1167 		if (tid_tx) {
1168 			bool queued;
1169 
1170 			queued = ieee80211_tx_prep_agg(tx, skb, info,
1171 						       tid_tx, tid);
1172 
1173 			if (unlikely(queued))
1174 				return TX_QUEUED;
1175 		}
1176 	}
1177 
1178 	if (is_multicast_ether_addr(hdr->addr1)) {
1179 		tx->flags &= ~IEEE80211_TX_UNICAST;
1180 		info->flags |= IEEE80211_TX_CTL_NO_ACK;
1181 	} else
1182 		tx->flags |= IEEE80211_TX_UNICAST;
1183 
1184 	if (!(info->flags & IEEE80211_TX_CTL_DONTFRAG)) {
1185 		if (!(tx->flags & IEEE80211_TX_UNICAST) ||
1186 		    skb->len + FCS_LEN <= local->hw.wiphy->frag_threshold ||
1187 		    info->flags & IEEE80211_TX_CTL_AMPDU)
1188 			info->flags |= IEEE80211_TX_CTL_DONTFRAG;
1189 	}
1190 
1191 	if (!tx->sta)
1192 		info->flags |= IEEE80211_TX_CTL_CLEAR_PS_FILT;
1193 	else if (test_and_clear_sta_flag(tx->sta, WLAN_STA_CLEAR_PS_FILT))
1194 		info->flags |= IEEE80211_TX_CTL_CLEAR_PS_FILT;
1195 
1196 	info->flags |= IEEE80211_TX_CTL_FIRST_FRAGMENT;
1197 
1198 	return TX_CONTINUE;
1199 }
1200 
1201 static bool ieee80211_tx_frags(struct ieee80211_local *local,
1202 			       struct ieee80211_vif *vif,
1203 			       struct ieee80211_sta *sta,
1204 			       struct sk_buff_head *skbs,
1205 			       bool txpending)
1206 {
1207 	struct sk_buff *skb, *tmp;
1208 	unsigned long flags;
1209 
1210 	skb_queue_walk_safe(skbs, skb, tmp) {
1211 		struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
1212 		int q = info->hw_queue;
1213 
1214 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG
1215 		if (WARN_ON_ONCE(q >= local->hw.queues)) {
1216 			__skb_unlink(skb, skbs);
1217 			dev_kfree_skb(skb);
1218 			continue;
1219 		}
1220 #endif
1221 
1222 		spin_lock_irqsave(&local->queue_stop_reason_lock, flags);
1223 		if (local->queue_stop_reasons[q] ||
1224 		    (!txpending && !skb_queue_empty(&local->pending[q]))) {
1225 			/*
1226 			 * Since queue is stopped, queue up frames for later
1227 			 * transmission from the tx-pending tasklet when the
1228 			 * queue is woken again.
1229 			 */
1230 			if (txpending)
1231 				skb_queue_splice_init(skbs, &local->pending[q]);
1232 			else
1233 				skb_queue_splice_tail_init(skbs,
1234 							   &local->pending[q]);
1235 
1236 			spin_unlock_irqrestore(&local->queue_stop_reason_lock,
1237 					       flags);
1238 			return false;
1239 		}
1240 		spin_unlock_irqrestore(&local->queue_stop_reason_lock, flags);
1241 
1242 		info->control.vif = vif;
1243 		info->control.sta = sta;
1244 
1245 		__skb_unlink(skb, skbs);
1246 		drv_tx(local, skb);
1247 	}
1248 
1249 	return true;
1250 }
1251 
1252 /*
1253  * Returns false if the frame couldn't be transmitted but was queued instead.
1254  */
1255 static bool __ieee80211_tx(struct ieee80211_local *local,
1256 			   struct sk_buff_head *skbs, int led_len,
1257 			   struct sta_info *sta, bool txpending)
1258 {
1259 	struct ieee80211_tx_info *info;
1260 	struct ieee80211_sub_if_data *sdata;
1261 	struct ieee80211_vif *vif;
1262 	struct ieee80211_sta *pubsta;
1263 	struct sk_buff *skb;
1264 	bool result = true;
1265 	__le16 fc;
1266 
1267 	if (WARN_ON(skb_queue_empty(skbs)))
1268 		return true;
1269 
1270 	skb = skb_peek(skbs);
1271 	fc = ((struct ieee80211_hdr *)skb->data)->frame_control;
1272 	info = IEEE80211_SKB_CB(skb);
1273 	sdata = vif_to_sdata(info->control.vif);
1274 	if (sta && !sta->uploaded)
1275 		sta = NULL;
1276 
1277 	if (sta)
1278 		pubsta = &sta->sta;
1279 	else
1280 		pubsta = NULL;
1281 
1282 	switch (sdata->vif.type) {
1283 	case NL80211_IFTYPE_MONITOR:
1284 		sdata = rcu_dereference(local->monitor_sdata);
1285 		if (sdata) {
1286 			vif = &sdata->vif;
1287 			info->hw_queue =
1288 				vif->hw_queue[skb_get_queue_mapping(skb)];
1289 		} else if (local->hw.flags & IEEE80211_HW_QUEUE_CONTROL) {
1290 			dev_kfree_skb(skb);
1291 			return true;
1292 		} else
1293 			vif = NULL;
1294 		break;
1295 	case NL80211_IFTYPE_AP_VLAN:
1296 		sdata = container_of(sdata->bss,
1297 				     struct ieee80211_sub_if_data, u.ap);
1298 		/* fall through */
1299 	default:
1300 		vif = &sdata->vif;
1301 		break;
1302 	}
1303 
1304 	result = ieee80211_tx_frags(local, vif, pubsta, skbs,
1305 				    txpending);
1306 
1307 	ieee80211_tpt_led_trig_tx(local, fc, led_len);
1308 	ieee80211_led_tx(local, 1);
1309 
1310 	WARN_ON_ONCE(!skb_queue_empty(skbs));
1311 
1312 	return result;
1313 }
1314 
1315 /*
1316  * Invoke TX handlers, return 0 on success and non-zero if the
1317  * frame was dropped or queued.
1318  */
1319 static int invoke_tx_handlers(struct ieee80211_tx_data *tx)
1320 {
1321 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(tx->skb);
1322 	ieee80211_tx_result res = TX_DROP;
1323 
1324 #define CALL_TXH(txh) \
1325 	do {				\
1326 		res = txh(tx);		\
1327 		if (res != TX_CONTINUE)	\
1328 			goto txh_done;	\
1329 	} while (0)
1330 
1331 	CALL_TXH(ieee80211_tx_h_dynamic_ps);
1332 	CALL_TXH(ieee80211_tx_h_check_assoc);
1333 	CALL_TXH(ieee80211_tx_h_ps_buf);
1334 	CALL_TXH(ieee80211_tx_h_check_control_port_protocol);
1335 	CALL_TXH(ieee80211_tx_h_select_key);
1336 	if (!(tx->local->hw.flags & IEEE80211_HW_HAS_RATE_CONTROL))
1337 		CALL_TXH(ieee80211_tx_h_rate_ctrl);
1338 
1339 	if (unlikely(info->flags & IEEE80211_TX_INTFL_RETRANSMISSION)) {
1340 		__skb_queue_tail(&tx->skbs, tx->skb);
1341 		tx->skb = NULL;
1342 		goto txh_done;
1343 	}
1344 
1345 	CALL_TXH(ieee80211_tx_h_michael_mic_add);
1346 	CALL_TXH(ieee80211_tx_h_sequence);
1347 	CALL_TXH(ieee80211_tx_h_fragment);
1348 	/* handlers after fragment must be aware of tx info fragmentation! */
1349 	CALL_TXH(ieee80211_tx_h_stats);
1350 	CALL_TXH(ieee80211_tx_h_encrypt);
1351 	if (!(tx->local->hw.flags & IEEE80211_HW_HAS_RATE_CONTROL))
1352 		CALL_TXH(ieee80211_tx_h_calculate_duration);
1353 #undef CALL_TXH
1354 
1355  txh_done:
1356 	if (unlikely(res == TX_DROP)) {
1357 		I802_DEBUG_INC(tx->local->tx_handlers_drop);
1358 		if (tx->skb)
1359 			dev_kfree_skb(tx->skb);
1360 		else
1361 			__skb_queue_purge(&tx->skbs);
1362 		return -1;
1363 	} else if (unlikely(res == TX_QUEUED)) {
1364 		I802_DEBUG_INC(tx->local->tx_handlers_queued);
1365 		return -1;
1366 	}
1367 
1368 	return 0;
1369 }
1370 
1371 /*
1372  * Returns false if the frame couldn't be transmitted but was queued instead.
1373  */
1374 static bool ieee80211_tx(struct ieee80211_sub_if_data *sdata,
1375 			 struct sk_buff *skb, bool txpending)
1376 {
1377 	struct ieee80211_local *local = sdata->local;
1378 	struct ieee80211_tx_data tx;
1379 	ieee80211_tx_result res_prepare;
1380 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
1381 	bool result = true;
1382 	int led_len;
1383 
1384 	if (unlikely(skb->len < 10)) {
1385 		dev_kfree_skb(skb);
1386 		return true;
1387 	}
1388 
1389 	rcu_read_lock();
1390 
1391 	/* initialises tx */
1392 	led_len = skb->len;
1393 	res_prepare = ieee80211_tx_prepare(sdata, &tx, skb);
1394 
1395 	if (unlikely(res_prepare == TX_DROP)) {
1396 		dev_kfree_skb(skb);
1397 		goto out;
1398 	} else if (unlikely(res_prepare == TX_QUEUED)) {
1399 		goto out;
1400 	}
1401 
1402 	tx.channel = local->hw.conf.channel;
1403 	info->band = tx.channel->band;
1404 
1405 	/* set up hw_queue value early */
1406 	if (!(info->flags & IEEE80211_TX_CTL_TX_OFFCHAN) ||
1407 	    !(local->hw.flags & IEEE80211_HW_QUEUE_CONTROL))
1408 		info->hw_queue =
1409 			sdata->vif.hw_queue[skb_get_queue_mapping(skb)];
1410 
1411 	if (!invoke_tx_handlers(&tx))
1412 		result = __ieee80211_tx(local, &tx.skbs, led_len,
1413 					tx.sta, txpending);
1414  out:
1415 	rcu_read_unlock();
1416 	return result;
1417 }
1418 
1419 /* device xmit handlers */
1420 
1421 static int ieee80211_skb_resize(struct ieee80211_sub_if_data *sdata,
1422 				struct sk_buff *skb,
1423 				int head_need, bool may_encrypt)
1424 {
1425 	struct ieee80211_local *local = sdata->local;
1426 	int tail_need = 0;
1427 
1428 	if (may_encrypt && sdata->crypto_tx_tailroom_needed_cnt) {
1429 		tail_need = IEEE80211_ENCRYPT_TAILROOM;
1430 		tail_need -= skb_tailroom(skb);
1431 		tail_need = max_t(int, tail_need, 0);
1432 	}
1433 
1434 	if (skb_cloned(skb))
1435 		I802_DEBUG_INC(local->tx_expand_skb_head_cloned);
1436 	else if (head_need || tail_need)
1437 		I802_DEBUG_INC(local->tx_expand_skb_head);
1438 	else
1439 		return 0;
1440 
1441 	if (pskb_expand_head(skb, head_need, tail_need, GFP_ATOMIC)) {
1442 		wiphy_debug(local->hw.wiphy,
1443 			    "failed to reallocate TX buffer\n");
1444 		return -ENOMEM;
1445 	}
1446 
1447 	return 0;
1448 }
1449 
1450 void ieee80211_xmit(struct ieee80211_sub_if_data *sdata, struct sk_buff *skb)
1451 {
1452 	struct ieee80211_local *local = sdata->local;
1453 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
1454 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
1455 	int headroom;
1456 	bool may_encrypt;
1457 
1458 	rcu_read_lock();
1459 
1460 	may_encrypt = !(info->flags & IEEE80211_TX_INTFL_DONT_ENCRYPT);
1461 
1462 	headroom = local->tx_headroom;
1463 	if (may_encrypt)
1464 		headroom += IEEE80211_ENCRYPT_HEADROOM;
1465 	headroom -= skb_headroom(skb);
1466 	headroom = max_t(int, 0, headroom);
1467 
1468 	if (ieee80211_skb_resize(sdata, skb, headroom, may_encrypt)) {
1469 		dev_kfree_skb(skb);
1470 		rcu_read_unlock();
1471 		return;
1472 	}
1473 
1474 	hdr = (struct ieee80211_hdr *) skb->data;
1475 	info->control.vif = &sdata->vif;
1476 
1477 	if (ieee80211_vif_is_mesh(&sdata->vif) &&
1478 	    ieee80211_is_data(hdr->frame_control) &&
1479 	    !is_multicast_ether_addr(hdr->addr1) &&
1480 	    mesh_nexthop_resolve(skb, sdata)) {
1481 		/* skb queued: don't free */
1482 		rcu_read_unlock();
1483 		return;
1484 	}
1485 
1486 	ieee80211_set_qos_hdr(sdata, skb);
1487 	ieee80211_tx(sdata, skb, false);
1488 	rcu_read_unlock();
1489 }
1490 
1491 static bool ieee80211_parse_tx_radiotap(struct sk_buff *skb)
1492 {
1493 	struct ieee80211_radiotap_iterator iterator;
1494 	struct ieee80211_radiotap_header *rthdr =
1495 		(struct ieee80211_radiotap_header *) skb->data;
1496 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
1497 	int ret = ieee80211_radiotap_iterator_init(&iterator, rthdr, skb->len,
1498 						   NULL);
1499 	u16 txflags;
1500 
1501 	info->flags |= IEEE80211_TX_INTFL_DONT_ENCRYPT |
1502 		       IEEE80211_TX_CTL_DONTFRAG;
1503 
1504 	/*
1505 	 * for every radiotap entry that is present
1506 	 * (ieee80211_radiotap_iterator_next returns -ENOENT when no more
1507 	 * entries present, or -EINVAL on error)
1508 	 */
1509 
1510 	while (!ret) {
1511 		ret = ieee80211_radiotap_iterator_next(&iterator);
1512 
1513 		if (ret)
1514 			continue;
1515 
1516 		/* see if this argument is something we can use */
1517 		switch (iterator.this_arg_index) {
1518 		/*
1519 		 * You must take care when dereferencing iterator.this_arg
1520 		 * for multibyte types... the pointer is not aligned.  Use
1521 		 * get_unaligned((type *)iterator.this_arg) to dereference
1522 		 * iterator.this_arg for type "type" safely on all arches.
1523 		*/
1524 		case IEEE80211_RADIOTAP_FLAGS:
1525 			if (*iterator.this_arg & IEEE80211_RADIOTAP_F_FCS) {
1526 				/*
1527 				 * this indicates that the skb we have been
1528 				 * handed has the 32-bit FCS CRC at the end...
1529 				 * we should react to that by snipping it off
1530 				 * because it will be recomputed and added
1531 				 * on transmission
1532 				 */
1533 				if (skb->len < (iterator._max_length + FCS_LEN))
1534 					return false;
1535 
1536 				skb_trim(skb, skb->len - FCS_LEN);
1537 			}
1538 			if (*iterator.this_arg & IEEE80211_RADIOTAP_F_WEP)
1539 				info->flags &= ~IEEE80211_TX_INTFL_DONT_ENCRYPT;
1540 			if (*iterator.this_arg & IEEE80211_RADIOTAP_F_FRAG)
1541 				info->flags &= ~IEEE80211_TX_CTL_DONTFRAG;
1542 			break;
1543 
1544 		case IEEE80211_RADIOTAP_TX_FLAGS:
1545 			txflags = get_unaligned_le16(iterator.this_arg);
1546 			if (txflags & IEEE80211_RADIOTAP_F_TX_NOACK)
1547 				info->flags |= IEEE80211_TX_CTL_NO_ACK;
1548 			break;
1549 
1550 		/*
1551 		 * Please update the file
1552 		 * Documentation/networking/mac80211-injection.txt
1553 		 * when parsing new fields here.
1554 		 */
1555 
1556 		default:
1557 			break;
1558 		}
1559 	}
1560 
1561 	if (ret != -ENOENT) /* ie, if we didn't simply run out of fields */
1562 		return false;
1563 
1564 	/*
1565 	 * remove the radiotap header
1566 	 * iterator->_max_length was sanity-checked against
1567 	 * skb->len by iterator init
1568 	 */
1569 	skb_pull(skb, iterator._max_length);
1570 
1571 	return true;
1572 }
1573 
1574 netdev_tx_t ieee80211_monitor_start_xmit(struct sk_buff *skb,
1575 					 struct net_device *dev)
1576 {
1577 	struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
1578 	struct ieee80211_channel *chan = local->hw.conf.channel;
1579 	struct ieee80211_radiotap_header *prthdr =
1580 		(struct ieee80211_radiotap_header *)skb->data;
1581 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
1582 	struct ieee80211_hdr *hdr;
1583 	struct ieee80211_sub_if_data *tmp_sdata, *sdata;
1584 	u16 len_rthdr;
1585 	int hdrlen;
1586 
1587 	/*
1588 	 * Frame injection is not allowed if beaconing is not allowed
1589 	 * or if we need radar detection. Beaconing is usually not allowed when
1590 	 * the mode or operation (Adhoc, AP, Mesh) does not support DFS.
1591 	 * Passive scan is also used in world regulatory domains where
1592 	 * your country is not known and as such it should be treated as
1593 	 * NO TX unless the channel is explicitly allowed in which case
1594 	 * your current regulatory domain would not have the passive scan
1595 	 * flag.
1596 	 *
1597 	 * Since AP mode uses monitor interfaces to inject/TX management
1598 	 * frames we can make AP mode the exception to this rule once it
1599 	 * supports radar detection as its implementation can deal with
1600 	 * radar detection by itself. We can do that later by adding a
1601 	 * monitor flag interfaces used for AP support.
1602 	 */
1603 	if ((chan->flags & (IEEE80211_CHAN_NO_IBSS | IEEE80211_CHAN_RADAR |
1604 	     IEEE80211_CHAN_PASSIVE_SCAN)))
1605 		goto fail;
1606 
1607 	/* check for not even having the fixed radiotap header part */
1608 	if (unlikely(skb->len < sizeof(struct ieee80211_radiotap_header)))
1609 		goto fail; /* too short to be possibly valid */
1610 
1611 	/* is it a header version we can trust to find length from? */
1612 	if (unlikely(prthdr->it_version))
1613 		goto fail; /* only version 0 is supported */
1614 
1615 	/* then there must be a radiotap header with a length we can use */
1616 	len_rthdr = ieee80211_get_radiotap_len(skb->data);
1617 
1618 	/* does the skb contain enough to deliver on the alleged length? */
1619 	if (unlikely(skb->len < len_rthdr))
1620 		goto fail; /* skb too short for claimed rt header extent */
1621 
1622 	/*
1623 	 * fix up the pointers accounting for the radiotap
1624 	 * header still being in there.  We are being given
1625 	 * a precooked IEEE80211 header so no need for
1626 	 * normal processing
1627 	 */
1628 	skb_set_mac_header(skb, len_rthdr);
1629 	/*
1630 	 * these are just fixed to the end of the rt area since we
1631 	 * don't have any better information and at this point, nobody cares
1632 	 */
1633 	skb_set_network_header(skb, len_rthdr);
1634 	skb_set_transport_header(skb, len_rthdr);
1635 
1636 	if (skb->len < len_rthdr + 2)
1637 		goto fail;
1638 
1639 	hdr = (struct ieee80211_hdr *)(skb->data + len_rthdr);
1640 	hdrlen = ieee80211_hdrlen(hdr->frame_control);
1641 
1642 	if (skb->len < len_rthdr + hdrlen)
1643 		goto fail;
1644 
1645 	/*
1646 	 * Initialize skb->protocol if the injected frame is a data frame
1647 	 * carrying a rfc1042 header
1648 	 */
1649 	if (ieee80211_is_data(hdr->frame_control) &&
1650 	    skb->len >= len_rthdr + hdrlen + sizeof(rfc1042_header) + 2) {
1651 		u8 *payload = (u8 *)hdr + hdrlen;
1652 
1653 		if (ether_addr_equal(payload, rfc1042_header))
1654 			skb->protocol = cpu_to_be16((payload[6] << 8) |
1655 						    payload[7]);
1656 	}
1657 
1658 	memset(info, 0, sizeof(*info));
1659 
1660 	info->flags = IEEE80211_TX_CTL_REQ_TX_STATUS |
1661 		      IEEE80211_TX_CTL_INJECTED;
1662 
1663 	/* process and remove the injection radiotap header */
1664 	if (!ieee80211_parse_tx_radiotap(skb))
1665 		goto fail;
1666 
1667 	rcu_read_lock();
1668 
1669 	/*
1670 	 * We process outgoing injected frames that have a local address
1671 	 * we handle as though they are non-injected frames.
1672 	 * This code here isn't entirely correct, the local MAC address
1673 	 * isn't always enough to find the interface to use; for proper
1674 	 * VLAN/WDS support we will need a different mechanism (which
1675 	 * likely isn't going to be monitor interfaces).
1676 	 */
1677 	sdata = IEEE80211_DEV_TO_SUB_IF(dev);
1678 
1679 	list_for_each_entry_rcu(tmp_sdata, &local->interfaces, list) {
1680 		if (!ieee80211_sdata_running(tmp_sdata))
1681 			continue;
1682 		if (tmp_sdata->vif.type == NL80211_IFTYPE_MONITOR ||
1683 		    tmp_sdata->vif.type == NL80211_IFTYPE_AP_VLAN ||
1684 		    tmp_sdata->vif.type == NL80211_IFTYPE_WDS)
1685 			continue;
1686 		if (ether_addr_equal(tmp_sdata->vif.addr, hdr->addr2)) {
1687 			sdata = tmp_sdata;
1688 			break;
1689 		}
1690 	}
1691 
1692 	ieee80211_xmit(sdata, skb);
1693 	rcu_read_unlock();
1694 
1695 	return NETDEV_TX_OK;
1696 
1697 fail:
1698 	dev_kfree_skb(skb);
1699 	return NETDEV_TX_OK; /* meaning, we dealt with the skb */
1700 }
1701 
1702 /**
1703  * ieee80211_subif_start_xmit - netif start_xmit function for Ethernet-type
1704  * subinterfaces (wlan#, WDS, and VLAN interfaces)
1705  * @skb: packet to be sent
1706  * @dev: incoming interface
1707  *
1708  * Returns: 0 on success (and frees skb in this case) or 1 on failure (skb will
1709  * not be freed, and caller is responsible for either retrying later or freeing
1710  * skb).
1711  *
1712  * This function takes in an Ethernet header and encapsulates it with suitable
1713  * IEEE 802.11 header based on which interface the packet is coming in. The
1714  * encapsulated packet will then be passed to master interface, wlan#.11, for
1715  * transmission (through low-level driver).
1716  */
1717 netdev_tx_t ieee80211_subif_start_xmit(struct sk_buff *skb,
1718 				    struct net_device *dev)
1719 {
1720 	struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
1721 	struct ieee80211_local *local = sdata->local;
1722 	struct ieee80211_tx_info *info;
1723 	int ret = NETDEV_TX_BUSY, head_need;
1724 	u16 ethertype, hdrlen,  meshhdrlen = 0;
1725 	__le16 fc;
1726 	struct ieee80211_hdr hdr;
1727 	struct ieee80211s_hdr mesh_hdr __maybe_unused;
1728 	struct mesh_path __maybe_unused *mppath = NULL, *mpath = NULL;
1729 	const u8 *encaps_data;
1730 	int encaps_len, skip_header_bytes;
1731 	int nh_pos, h_pos;
1732 	struct sta_info *sta = NULL;
1733 	bool wme_sta = false, authorized = false, tdls_auth = false;
1734 	bool tdls_direct = false;
1735 	bool multicast;
1736 	u32 info_flags = 0;
1737 	u16 info_id = 0;
1738 
1739 	if (unlikely(skb->len < ETH_HLEN)) {
1740 		ret = NETDEV_TX_OK;
1741 		goto fail;
1742 	}
1743 
1744 	/* convert Ethernet header to proper 802.11 header (based on
1745 	 * operation mode) */
1746 	ethertype = (skb->data[12] << 8) | skb->data[13];
1747 	fc = cpu_to_le16(IEEE80211_FTYPE_DATA | IEEE80211_STYPE_DATA);
1748 
1749 	switch (sdata->vif.type) {
1750 	case NL80211_IFTYPE_AP_VLAN:
1751 		rcu_read_lock();
1752 		sta = rcu_dereference(sdata->u.vlan.sta);
1753 		if (sta) {
1754 			fc |= cpu_to_le16(IEEE80211_FCTL_FROMDS | IEEE80211_FCTL_TODS);
1755 			/* RA TA DA SA */
1756 			memcpy(hdr.addr1, sta->sta.addr, ETH_ALEN);
1757 			memcpy(hdr.addr2, sdata->vif.addr, ETH_ALEN);
1758 			memcpy(hdr.addr3, skb->data, ETH_ALEN);
1759 			memcpy(hdr.addr4, skb->data + ETH_ALEN, ETH_ALEN);
1760 			hdrlen = 30;
1761 			authorized = test_sta_flag(sta, WLAN_STA_AUTHORIZED);
1762 			wme_sta = test_sta_flag(sta, WLAN_STA_WME);
1763 		}
1764 		rcu_read_unlock();
1765 		if (sta)
1766 			break;
1767 		/* fall through */
1768 	case NL80211_IFTYPE_AP:
1769 		fc |= cpu_to_le16(IEEE80211_FCTL_FROMDS);
1770 		/* DA BSSID SA */
1771 		memcpy(hdr.addr1, skb->data, ETH_ALEN);
1772 		memcpy(hdr.addr2, sdata->vif.addr, ETH_ALEN);
1773 		memcpy(hdr.addr3, skb->data + ETH_ALEN, ETH_ALEN);
1774 		hdrlen = 24;
1775 		break;
1776 	case NL80211_IFTYPE_WDS:
1777 		fc |= cpu_to_le16(IEEE80211_FCTL_FROMDS | IEEE80211_FCTL_TODS);
1778 		/* RA TA DA SA */
1779 		memcpy(hdr.addr1, sdata->u.wds.remote_addr, ETH_ALEN);
1780 		memcpy(hdr.addr2, sdata->vif.addr, ETH_ALEN);
1781 		memcpy(hdr.addr3, skb->data, ETH_ALEN);
1782 		memcpy(hdr.addr4, skb->data + ETH_ALEN, ETH_ALEN);
1783 		hdrlen = 30;
1784 		break;
1785 #ifdef CONFIG_MAC80211_MESH
1786 	case NL80211_IFTYPE_MESH_POINT:
1787 		if (!sdata->u.mesh.mshcfg.dot11MeshTTL) {
1788 			/* Do not send frames with mesh_ttl == 0 */
1789 			sdata->u.mesh.mshstats.dropped_frames_ttl++;
1790 			ret = NETDEV_TX_OK;
1791 			goto fail;
1792 		}
1793 		rcu_read_lock();
1794 		if (!is_multicast_ether_addr(skb->data)) {
1795 			mpath = mesh_path_lookup(skb->data, sdata);
1796 			if (!mpath)
1797 				mppath = mpp_path_lookup(skb->data, sdata);
1798 		}
1799 
1800 		/*
1801 		 * Use address extension if it is a packet from
1802 		 * another interface or if we know the destination
1803 		 * is being proxied by a portal (i.e. portal address
1804 		 * differs from proxied address)
1805 		 */
1806 		if (ether_addr_equal(sdata->vif.addr, skb->data + ETH_ALEN) &&
1807 		    !(mppath && !ether_addr_equal(mppath->mpp, skb->data))) {
1808 			hdrlen = ieee80211_fill_mesh_addresses(&hdr, &fc,
1809 					skb->data, skb->data + ETH_ALEN);
1810 			rcu_read_unlock();
1811 			meshhdrlen = ieee80211_new_mesh_header(&mesh_hdr,
1812 					sdata, NULL, NULL);
1813 		} else {
1814 			/* DS -> MBSS (802.11-2012 13.11.3.3).
1815 			 * For unicast with unknown forwarding information,
1816 			 * destination might be in the MBSS or if that fails
1817 			 * forwarded to another mesh gate. In either case
1818 			 * resolution will be handled in ieee80211_xmit(), so
1819 			 * leave the original DA. This also works for mcast */
1820 			const u8 *mesh_da = skb->data;
1821 
1822 			if (mppath)
1823 				mesh_da = mppath->mpp;
1824 			else if (mpath)
1825 				mesh_da = mpath->dst;
1826 			rcu_read_unlock();
1827 
1828 			hdrlen = ieee80211_fill_mesh_addresses(&hdr, &fc,
1829 					mesh_da, sdata->vif.addr);
1830 			if (is_multicast_ether_addr(mesh_da))
1831 				/* DA TA mSA AE:SA */
1832 				meshhdrlen =
1833 					ieee80211_new_mesh_header(&mesh_hdr,
1834 							sdata,
1835 							skb->data + ETH_ALEN,
1836 							NULL);
1837 			else
1838 				/* RA TA mDA mSA AE:DA SA */
1839 				meshhdrlen =
1840 					ieee80211_new_mesh_header(&mesh_hdr,
1841 							sdata,
1842 							skb->data,
1843 							skb->data + ETH_ALEN);
1844 
1845 		}
1846 		break;
1847 #endif
1848 	case NL80211_IFTYPE_STATION:
1849 		if (sdata->wdev.wiphy->flags & WIPHY_FLAG_SUPPORTS_TDLS) {
1850 			bool tdls_peer = false;
1851 
1852 			rcu_read_lock();
1853 			sta = sta_info_get(sdata, skb->data);
1854 			if (sta) {
1855 				authorized = test_sta_flag(sta,
1856 							WLAN_STA_AUTHORIZED);
1857 				wme_sta = test_sta_flag(sta, WLAN_STA_WME);
1858 				tdls_peer = test_sta_flag(sta,
1859 							 WLAN_STA_TDLS_PEER);
1860 				tdls_auth = test_sta_flag(sta,
1861 						WLAN_STA_TDLS_PEER_AUTH);
1862 			}
1863 			rcu_read_unlock();
1864 
1865 			/*
1866 			 * If the TDLS link is enabled, send everything
1867 			 * directly. Otherwise, allow TDLS setup frames
1868 			 * to be transmitted indirectly.
1869 			 */
1870 			tdls_direct = tdls_peer && (tdls_auth ||
1871 				 !(ethertype == ETH_P_TDLS && skb->len > 14 &&
1872 				   skb->data[14] == WLAN_TDLS_SNAP_RFTYPE));
1873 		}
1874 
1875 		if (tdls_direct) {
1876 			/* link during setup - throw out frames to peer */
1877 			if (!tdls_auth) {
1878 				ret = NETDEV_TX_OK;
1879 				goto fail;
1880 			}
1881 
1882 			/* DA SA BSSID */
1883 			memcpy(hdr.addr1, skb->data, ETH_ALEN);
1884 			memcpy(hdr.addr2, skb->data + ETH_ALEN, ETH_ALEN);
1885 			memcpy(hdr.addr3, sdata->u.mgd.bssid, ETH_ALEN);
1886 			hdrlen = 24;
1887 		}  else if (sdata->u.mgd.use_4addr &&
1888 			    cpu_to_be16(ethertype) != sdata->control_port_protocol) {
1889 			fc |= cpu_to_le16(IEEE80211_FCTL_FROMDS |
1890 					  IEEE80211_FCTL_TODS);
1891 			/* RA TA DA SA */
1892 			memcpy(hdr.addr1, sdata->u.mgd.bssid, ETH_ALEN);
1893 			memcpy(hdr.addr2, sdata->vif.addr, ETH_ALEN);
1894 			memcpy(hdr.addr3, skb->data, ETH_ALEN);
1895 			memcpy(hdr.addr4, skb->data + ETH_ALEN, ETH_ALEN);
1896 			hdrlen = 30;
1897 		} else {
1898 			fc |= cpu_to_le16(IEEE80211_FCTL_TODS);
1899 			/* BSSID SA DA */
1900 			memcpy(hdr.addr1, sdata->u.mgd.bssid, ETH_ALEN);
1901 			memcpy(hdr.addr2, skb->data + ETH_ALEN, ETH_ALEN);
1902 			memcpy(hdr.addr3, skb->data, ETH_ALEN);
1903 			hdrlen = 24;
1904 		}
1905 		break;
1906 	case NL80211_IFTYPE_ADHOC:
1907 		/* DA SA BSSID */
1908 		memcpy(hdr.addr1, skb->data, ETH_ALEN);
1909 		memcpy(hdr.addr2, skb->data + ETH_ALEN, ETH_ALEN);
1910 		memcpy(hdr.addr3, sdata->u.ibss.bssid, ETH_ALEN);
1911 		hdrlen = 24;
1912 		break;
1913 	default:
1914 		ret = NETDEV_TX_OK;
1915 		goto fail;
1916 	}
1917 
1918 	/*
1919 	 * There's no need to try to look up the destination
1920 	 * if it is a multicast address (which can only happen
1921 	 * in AP mode)
1922 	 */
1923 	multicast = is_multicast_ether_addr(hdr.addr1);
1924 	if (!multicast) {
1925 		rcu_read_lock();
1926 		sta = sta_info_get(sdata, hdr.addr1);
1927 		if (sta) {
1928 			authorized = test_sta_flag(sta, WLAN_STA_AUTHORIZED);
1929 			wme_sta = test_sta_flag(sta, WLAN_STA_WME);
1930 		}
1931 		rcu_read_unlock();
1932 	}
1933 
1934 	/* For mesh, the use of the QoS header is mandatory */
1935 	if (ieee80211_vif_is_mesh(&sdata->vif))
1936 		wme_sta = true;
1937 
1938 	/* receiver and we are QoS enabled, use a QoS type frame */
1939 	if (wme_sta && local->hw.queues >= IEEE80211_NUM_ACS) {
1940 		fc |= cpu_to_le16(IEEE80211_STYPE_QOS_DATA);
1941 		hdrlen += 2;
1942 	}
1943 
1944 	/*
1945 	 * Drop unicast frames to unauthorised stations unless they are
1946 	 * EAPOL frames from the local station.
1947 	 */
1948 	if (unlikely(!ieee80211_vif_is_mesh(&sdata->vif) &&
1949 		     !is_multicast_ether_addr(hdr.addr1) && !authorized &&
1950 		     (cpu_to_be16(ethertype) != sdata->control_port_protocol ||
1951 		      !ether_addr_equal(sdata->vif.addr, skb->data + ETH_ALEN)))) {
1952 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG
1953 		net_info_ratelimited("%s: dropped frame to %pM (unauthorized port)\n",
1954 				    dev->name, hdr.addr1);
1955 #endif
1956 
1957 		I802_DEBUG_INC(local->tx_handlers_drop_unauth_port);
1958 
1959 		ret = NETDEV_TX_OK;
1960 		goto fail;
1961 	}
1962 
1963 	if (unlikely(!multicast && skb->sk &&
1964 		     skb_shinfo(skb)->tx_flags & SKBTX_WIFI_STATUS)) {
1965 		struct sk_buff *orig_skb = skb;
1966 
1967 		skb = skb_clone(skb, GFP_ATOMIC);
1968 		if (skb) {
1969 			unsigned long flags;
1970 			int id, r;
1971 
1972 			spin_lock_irqsave(&local->ack_status_lock, flags);
1973 			r = idr_get_new_above(&local->ack_status_frames,
1974 					      orig_skb, 1, &id);
1975 			if (r == -EAGAIN) {
1976 				idr_pre_get(&local->ack_status_frames,
1977 					    GFP_ATOMIC);
1978 				r = idr_get_new_above(&local->ack_status_frames,
1979 						      orig_skb, 1, &id);
1980 			}
1981 			if (WARN_ON(!id) || id > 0xffff) {
1982 				idr_remove(&local->ack_status_frames, id);
1983 				r = -ERANGE;
1984 			}
1985 			spin_unlock_irqrestore(&local->ack_status_lock, flags);
1986 
1987 			if (!r) {
1988 				info_id = id;
1989 				info_flags |= IEEE80211_TX_CTL_REQ_TX_STATUS;
1990 			} else if (skb_shared(skb)) {
1991 				kfree_skb(orig_skb);
1992 			} else {
1993 				kfree_skb(skb);
1994 				skb = orig_skb;
1995 			}
1996 		} else {
1997 			/* couldn't clone -- lose tx status ... */
1998 			skb = orig_skb;
1999 		}
2000 	}
2001 
2002 	/*
2003 	 * If the skb is shared we need to obtain our own copy.
2004 	 */
2005 	if (skb_shared(skb)) {
2006 		struct sk_buff *tmp_skb = skb;
2007 
2008 		/* can't happen -- skb is a clone if info_id != 0 */
2009 		WARN_ON(info_id);
2010 
2011 		skb = skb_clone(skb, GFP_ATOMIC);
2012 		kfree_skb(tmp_skb);
2013 
2014 		if (!skb) {
2015 			ret = NETDEV_TX_OK;
2016 			goto fail;
2017 		}
2018 	}
2019 
2020 	hdr.frame_control = fc;
2021 	hdr.duration_id = 0;
2022 	hdr.seq_ctrl = 0;
2023 
2024 	skip_header_bytes = ETH_HLEN;
2025 	if (ethertype == ETH_P_AARP || ethertype == ETH_P_IPX) {
2026 		encaps_data = bridge_tunnel_header;
2027 		encaps_len = sizeof(bridge_tunnel_header);
2028 		skip_header_bytes -= 2;
2029 	} else if (ethertype >= 0x600) {
2030 		encaps_data = rfc1042_header;
2031 		encaps_len = sizeof(rfc1042_header);
2032 		skip_header_bytes -= 2;
2033 	} else {
2034 		encaps_data = NULL;
2035 		encaps_len = 0;
2036 	}
2037 
2038 	nh_pos = skb_network_header(skb) - skb->data;
2039 	h_pos = skb_transport_header(skb) - skb->data;
2040 
2041 	skb_pull(skb, skip_header_bytes);
2042 	nh_pos -= skip_header_bytes;
2043 	h_pos -= skip_header_bytes;
2044 
2045 	head_need = hdrlen + encaps_len + meshhdrlen - skb_headroom(skb);
2046 
2047 	/*
2048 	 * So we need to modify the skb header and hence need a copy of
2049 	 * that. The head_need variable above doesn't, so far, include
2050 	 * the needed header space that we don't need right away. If we
2051 	 * can, then we don't reallocate right now but only after the
2052 	 * frame arrives at the master device (if it does...)
2053 	 *
2054 	 * If we cannot, however, then we will reallocate to include all
2055 	 * the ever needed space. Also, if we need to reallocate it anyway,
2056 	 * make it big enough for everything we may ever need.
2057 	 */
2058 
2059 	if (head_need > 0 || skb_cloned(skb)) {
2060 		head_need += IEEE80211_ENCRYPT_HEADROOM;
2061 		head_need += local->tx_headroom;
2062 		head_need = max_t(int, 0, head_need);
2063 		if (ieee80211_skb_resize(sdata, skb, head_need, true))
2064 			goto fail;
2065 	}
2066 
2067 	if (encaps_data) {
2068 		memcpy(skb_push(skb, encaps_len), encaps_data, encaps_len);
2069 		nh_pos += encaps_len;
2070 		h_pos += encaps_len;
2071 	}
2072 
2073 #ifdef CONFIG_MAC80211_MESH
2074 	if (meshhdrlen > 0) {
2075 		memcpy(skb_push(skb, meshhdrlen), &mesh_hdr, meshhdrlen);
2076 		nh_pos += meshhdrlen;
2077 		h_pos += meshhdrlen;
2078 	}
2079 #endif
2080 
2081 	if (ieee80211_is_data_qos(fc)) {
2082 		__le16 *qos_control;
2083 
2084 		qos_control = (__le16*) skb_push(skb, 2);
2085 		memcpy(skb_push(skb, hdrlen - 2), &hdr, hdrlen - 2);
2086 		/*
2087 		 * Maybe we could actually set some fields here, for now just
2088 		 * initialise to zero to indicate no special operation.
2089 		 */
2090 		*qos_control = 0;
2091 	} else
2092 		memcpy(skb_push(skb, hdrlen), &hdr, hdrlen);
2093 
2094 	nh_pos += hdrlen;
2095 	h_pos += hdrlen;
2096 
2097 	dev->stats.tx_packets++;
2098 	dev->stats.tx_bytes += skb->len;
2099 
2100 	/* Update skb pointers to various headers since this modified frame
2101 	 * is going to go through Linux networking code that may potentially
2102 	 * need things like pointer to IP header. */
2103 	skb_set_mac_header(skb, 0);
2104 	skb_set_network_header(skb, nh_pos);
2105 	skb_set_transport_header(skb, h_pos);
2106 
2107 	info = IEEE80211_SKB_CB(skb);
2108 	memset(info, 0, sizeof(*info));
2109 
2110 	dev->trans_start = jiffies;
2111 
2112 	info->flags = info_flags;
2113 	info->ack_frame_id = info_id;
2114 
2115 	ieee80211_xmit(sdata, skb);
2116 
2117 	return NETDEV_TX_OK;
2118 
2119  fail:
2120 	if (ret == NETDEV_TX_OK)
2121 		dev_kfree_skb(skb);
2122 
2123 	return ret;
2124 }
2125 
2126 
2127 /*
2128  * ieee80211_clear_tx_pending may not be called in a context where
2129  * it is possible that it packets could come in again.
2130  */
2131 void ieee80211_clear_tx_pending(struct ieee80211_local *local)
2132 {
2133 	int i;
2134 
2135 	for (i = 0; i < local->hw.queues; i++)
2136 		skb_queue_purge(&local->pending[i]);
2137 }
2138 
2139 /*
2140  * Returns false if the frame couldn't be transmitted but was queued instead,
2141  * which in this case means re-queued -- take as an indication to stop sending
2142  * more pending frames.
2143  */
2144 static bool ieee80211_tx_pending_skb(struct ieee80211_local *local,
2145 				     struct sk_buff *skb)
2146 {
2147 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
2148 	struct ieee80211_sub_if_data *sdata;
2149 	struct sta_info *sta;
2150 	struct ieee80211_hdr *hdr;
2151 	bool result;
2152 
2153 	sdata = vif_to_sdata(info->control.vif);
2154 
2155 	if (info->flags & IEEE80211_TX_INTFL_NEED_TXPROCESSING) {
2156 		result = ieee80211_tx(sdata, skb, true);
2157 	} else {
2158 		struct sk_buff_head skbs;
2159 
2160 		__skb_queue_head_init(&skbs);
2161 		__skb_queue_tail(&skbs, skb);
2162 
2163 		hdr = (struct ieee80211_hdr *)skb->data;
2164 		sta = sta_info_get(sdata, hdr->addr1);
2165 
2166 		result = __ieee80211_tx(local, &skbs, skb->len, sta, true);
2167 	}
2168 
2169 	return result;
2170 }
2171 
2172 /*
2173  * Transmit all pending packets. Called from tasklet.
2174  */
2175 void ieee80211_tx_pending(unsigned long data)
2176 {
2177 	struct ieee80211_local *local = (struct ieee80211_local *)data;
2178 	unsigned long flags;
2179 	int i;
2180 	bool txok;
2181 
2182 	rcu_read_lock();
2183 
2184 	spin_lock_irqsave(&local->queue_stop_reason_lock, flags);
2185 	for (i = 0; i < local->hw.queues; i++) {
2186 		/*
2187 		 * If queue is stopped by something other than due to pending
2188 		 * frames, or we have no pending frames, proceed to next queue.
2189 		 */
2190 		if (local->queue_stop_reasons[i] ||
2191 		    skb_queue_empty(&local->pending[i]))
2192 			continue;
2193 
2194 		while (!skb_queue_empty(&local->pending[i])) {
2195 			struct sk_buff *skb = __skb_dequeue(&local->pending[i]);
2196 			struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
2197 
2198 			if (WARN_ON(!info->control.vif)) {
2199 				kfree_skb(skb);
2200 				continue;
2201 			}
2202 
2203 			spin_unlock_irqrestore(&local->queue_stop_reason_lock,
2204 						flags);
2205 
2206 			txok = ieee80211_tx_pending_skb(local, skb);
2207 			spin_lock_irqsave(&local->queue_stop_reason_lock,
2208 					  flags);
2209 			if (!txok)
2210 				break;
2211 		}
2212 
2213 		if (skb_queue_empty(&local->pending[i]))
2214 			ieee80211_propagate_queue_wake(local, i);
2215 	}
2216 	spin_unlock_irqrestore(&local->queue_stop_reason_lock, flags);
2217 
2218 	rcu_read_unlock();
2219 }
2220 
2221 /* functions for drivers to get certain frames */
2222 
2223 static void ieee80211_beacon_add_tim(struct ieee80211_sub_if_data *sdata,
2224 				     struct ieee80211_if_ap *bss,
2225 				     struct sk_buff *skb,
2226 				     struct beacon_data *beacon)
2227 {
2228 	u8 *pos, *tim;
2229 	int aid0 = 0;
2230 	int i, have_bits = 0, n1, n2;
2231 
2232 	/* Generate bitmap for TIM only if there are any STAs in power save
2233 	 * mode. */
2234 	if (atomic_read(&bss->num_sta_ps) > 0)
2235 		/* in the hope that this is faster than
2236 		 * checking byte-for-byte */
2237 		have_bits = !bitmap_empty((unsigned long*)bss->tim,
2238 					  IEEE80211_MAX_AID+1);
2239 
2240 	if (bss->dtim_count == 0)
2241 		bss->dtim_count = sdata->vif.bss_conf.dtim_period - 1;
2242 	else
2243 		bss->dtim_count--;
2244 
2245 	tim = pos = (u8 *) skb_put(skb, 6);
2246 	*pos++ = WLAN_EID_TIM;
2247 	*pos++ = 4;
2248 	*pos++ = bss->dtim_count;
2249 	*pos++ = sdata->vif.bss_conf.dtim_period;
2250 
2251 	if (bss->dtim_count == 0 && !skb_queue_empty(&bss->ps_bc_buf))
2252 		aid0 = 1;
2253 
2254 	bss->dtim_bc_mc = aid0 == 1;
2255 
2256 	if (have_bits) {
2257 		/* Find largest even number N1 so that bits numbered 1 through
2258 		 * (N1 x 8) - 1 in the bitmap are 0 and number N2 so that bits
2259 		 * (N2 + 1) x 8 through 2007 are 0. */
2260 		n1 = 0;
2261 		for (i = 0; i < IEEE80211_MAX_TIM_LEN; i++) {
2262 			if (bss->tim[i]) {
2263 				n1 = i & 0xfe;
2264 				break;
2265 			}
2266 		}
2267 		n2 = n1;
2268 		for (i = IEEE80211_MAX_TIM_LEN - 1; i >= n1; i--) {
2269 			if (bss->tim[i]) {
2270 				n2 = i;
2271 				break;
2272 			}
2273 		}
2274 
2275 		/* Bitmap control */
2276 		*pos++ = n1 | aid0;
2277 		/* Part Virt Bitmap */
2278 		skb_put(skb, n2 - n1);
2279 		memcpy(pos, bss->tim + n1, n2 - n1 + 1);
2280 
2281 		tim[1] = n2 - n1 + 4;
2282 	} else {
2283 		*pos++ = aid0; /* Bitmap control */
2284 		*pos++ = 0; /* Part Virt Bitmap */
2285 	}
2286 }
2287 
2288 struct sk_buff *ieee80211_beacon_get_tim(struct ieee80211_hw *hw,
2289 					 struct ieee80211_vif *vif,
2290 					 u16 *tim_offset, u16 *tim_length)
2291 {
2292 	struct ieee80211_local *local = hw_to_local(hw);
2293 	struct sk_buff *skb = NULL;
2294 	struct ieee80211_tx_info *info;
2295 	struct ieee80211_sub_if_data *sdata = NULL;
2296 	struct ieee80211_if_ap *ap = NULL;
2297 	struct beacon_data *beacon;
2298 	struct ieee80211_supported_band *sband;
2299 	enum ieee80211_band band = local->hw.conf.channel->band;
2300 	struct ieee80211_tx_rate_control txrc;
2301 
2302 	sband = local->hw.wiphy->bands[band];
2303 
2304 	rcu_read_lock();
2305 
2306 	sdata = vif_to_sdata(vif);
2307 
2308 	if (!ieee80211_sdata_running(sdata))
2309 		goto out;
2310 
2311 	if (tim_offset)
2312 		*tim_offset = 0;
2313 	if (tim_length)
2314 		*tim_length = 0;
2315 
2316 	if (sdata->vif.type == NL80211_IFTYPE_AP) {
2317 		ap = &sdata->u.ap;
2318 		beacon = rcu_dereference(ap->beacon);
2319 		if (beacon) {
2320 			/*
2321 			 * headroom, head length,
2322 			 * tail length and maximum TIM length
2323 			 */
2324 			skb = dev_alloc_skb(local->tx_headroom +
2325 					    beacon->head_len +
2326 					    beacon->tail_len + 256);
2327 			if (!skb)
2328 				goto out;
2329 
2330 			skb_reserve(skb, local->tx_headroom);
2331 			memcpy(skb_put(skb, beacon->head_len), beacon->head,
2332 			       beacon->head_len);
2333 
2334 			/*
2335 			 * Not very nice, but we want to allow the driver to call
2336 			 * ieee80211_beacon_get() as a response to the set_tim()
2337 			 * callback. That, however, is already invoked under the
2338 			 * sta_lock to guarantee consistent and race-free update
2339 			 * of the tim bitmap in mac80211 and the driver.
2340 			 */
2341 			if (local->tim_in_locked_section) {
2342 				ieee80211_beacon_add_tim(sdata, ap, skb,
2343 							 beacon);
2344 			} else {
2345 				unsigned long flags;
2346 
2347 				spin_lock_irqsave(&local->tim_lock, flags);
2348 				ieee80211_beacon_add_tim(sdata, ap, skb,
2349 							 beacon);
2350 				spin_unlock_irqrestore(&local->tim_lock, flags);
2351 			}
2352 
2353 			if (tim_offset)
2354 				*tim_offset = beacon->head_len;
2355 			if (tim_length)
2356 				*tim_length = skb->len - beacon->head_len;
2357 
2358 			if (beacon->tail)
2359 				memcpy(skb_put(skb, beacon->tail_len),
2360 				       beacon->tail, beacon->tail_len);
2361 		} else
2362 			goto out;
2363 	} else if (sdata->vif.type == NL80211_IFTYPE_ADHOC) {
2364 		struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
2365 		struct ieee80211_hdr *hdr;
2366 		struct sk_buff *presp = rcu_dereference(ifibss->presp);
2367 
2368 		if (!presp)
2369 			goto out;
2370 
2371 		skb = skb_copy(presp, GFP_ATOMIC);
2372 		if (!skb)
2373 			goto out;
2374 
2375 		hdr = (struct ieee80211_hdr *) skb->data;
2376 		hdr->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
2377 						 IEEE80211_STYPE_BEACON);
2378 	} else if (ieee80211_vif_is_mesh(&sdata->vif)) {
2379 		struct ieee80211_mgmt *mgmt;
2380 		struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
2381 		u8 *pos;
2382 		int hdr_len = offsetof(struct ieee80211_mgmt, u.beacon) +
2383 			      sizeof(mgmt->u.beacon);
2384 
2385 #ifdef CONFIG_MAC80211_MESH
2386 		if (!sdata->u.mesh.mesh_id_len)
2387 			goto out;
2388 #endif
2389 
2390 		if (ifmsh->sync_ops)
2391 			ifmsh->sync_ops->adjust_tbtt(
2392 						sdata);
2393 
2394 		skb = dev_alloc_skb(local->tx_headroom +
2395 				    hdr_len +
2396 				    2 + /* NULL SSID */
2397 				    2 + 8 + /* supported rates */
2398 				    2 + 3 + /* DS params */
2399 				    2 + (IEEE80211_MAX_SUPP_RATES - 8) +
2400 				    2 + sizeof(struct ieee80211_ht_cap) +
2401 				    2 + sizeof(struct ieee80211_ht_operation) +
2402 				    2 + sdata->u.mesh.mesh_id_len +
2403 				    2 + sizeof(struct ieee80211_meshconf_ie) +
2404 				    sdata->u.mesh.ie_len);
2405 		if (!skb)
2406 			goto out;
2407 
2408 		skb_reserve(skb, local->hw.extra_tx_headroom);
2409 		mgmt = (struct ieee80211_mgmt *) skb_put(skb, hdr_len);
2410 		memset(mgmt, 0, hdr_len);
2411 		mgmt->frame_control =
2412 		    cpu_to_le16(IEEE80211_FTYPE_MGMT | IEEE80211_STYPE_BEACON);
2413 		memset(mgmt->da, 0xff, ETH_ALEN);
2414 		memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
2415 		memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN);
2416 		mgmt->u.beacon.beacon_int =
2417 			cpu_to_le16(sdata->vif.bss_conf.beacon_int);
2418 		mgmt->u.beacon.capab_info |= cpu_to_le16(
2419 			sdata->u.mesh.security ? WLAN_CAPABILITY_PRIVACY : 0);
2420 
2421 		pos = skb_put(skb, 2);
2422 		*pos++ = WLAN_EID_SSID;
2423 		*pos++ = 0x0;
2424 
2425 		if (ieee80211_add_srates_ie(sdata, skb, true) ||
2426 		    mesh_add_ds_params_ie(skb, sdata) ||
2427 		    ieee80211_add_ext_srates_ie(sdata, skb, true) ||
2428 		    mesh_add_rsn_ie(skb, sdata) ||
2429 		    mesh_add_ht_cap_ie(skb, sdata) ||
2430 		    mesh_add_ht_oper_ie(skb, sdata) ||
2431 		    mesh_add_meshid_ie(skb, sdata) ||
2432 		    mesh_add_meshconf_ie(skb, sdata) ||
2433 		    mesh_add_vendor_ies(skb, sdata)) {
2434 			pr_err("o11s: couldn't add ies!\n");
2435 			goto out;
2436 		}
2437 	} else {
2438 		WARN_ON(1);
2439 		goto out;
2440 	}
2441 
2442 	info = IEEE80211_SKB_CB(skb);
2443 
2444 	info->flags |= IEEE80211_TX_INTFL_DONT_ENCRYPT;
2445 	info->flags |= IEEE80211_TX_CTL_NO_ACK;
2446 	info->band = band;
2447 
2448 	memset(&txrc, 0, sizeof(txrc));
2449 	txrc.hw = hw;
2450 	txrc.sband = sband;
2451 	txrc.bss_conf = &sdata->vif.bss_conf;
2452 	txrc.skb = skb;
2453 	txrc.reported_rate.idx = -1;
2454 	txrc.rate_idx_mask = sdata->rc_rateidx_mask[band];
2455 	if (txrc.rate_idx_mask == (1 << sband->n_bitrates) - 1)
2456 		txrc.max_rate_idx = -1;
2457 	else
2458 		txrc.max_rate_idx = fls(txrc.rate_idx_mask) - 1;
2459 	memcpy(txrc.rate_idx_mcs_mask, sdata->rc_rateidx_mcs_mask[band],
2460 	       sizeof(txrc.rate_idx_mcs_mask));
2461 	txrc.bss = true;
2462 	rate_control_get_rate(sdata, NULL, &txrc);
2463 
2464 	info->control.vif = vif;
2465 
2466 	info->flags |= IEEE80211_TX_CTL_CLEAR_PS_FILT |
2467 			IEEE80211_TX_CTL_ASSIGN_SEQ |
2468 			IEEE80211_TX_CTL_FIRST_FRAGMENT;
2469  out:
2470 	rcu_read_unlock();
2471 	return skb;
2472 }
2473 EXPORT_SYMBOL(ieee80211_beacon_get_tim);
2474 
2475 struct sk_buff *ieee80211_proberesp_get(struct ieee80211_hw *hw,
2476 					struct ieee80211_vif *vif)
2477 {
2478 	struct ieee80211_if_ap *ap = NULL;
2479 	struct sk_buff *presp = NULL, *skb = NULL;
2480 	struct ieee80211_hdr *hdr;
2481 	struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
2482 
2483 	if (sdata->vif.type != NL80211_IFTYPE_AP)
2484 		return NULL;
2485 
2486 	rcu_read_lock();
2487 
2488 	ap = &sdata->u.ap;
2489 	presp = rcu_dereference(ap->probe_resp);
2490 	if (!presp)
2491 		goto out;
2492 
2493 	skb = skb_copy(presp, GFP_ATOMIC);
2494 	if (!skb)
2495 		goto out;
2496 
2497 	hdr = (struct ieee80211_hdr *) skb->data;
2498 	memset(hdr->addr1, 0, sizeof(hdr->addr1));
2499 
2500 out:
2501 	rcu_read_unlock();
2502 	return skb;
2503 }
2504 EXPORT_SYMBOL(ieee80211_proberesp_get);
2505 
2506 struct sk_buff *ieee80211_pspoll_get(struct ieee80211_hw *hw,
2507 				     struct ieee80211_vif *vif)
2508 {
2509 	struct ieee80211_sub_if_data *sdata;
2510 	struct ieee80211_if_managed *ifmgd;
2511 	struct ieee80211_pspoll *pspoll;
2512 	struct ieee80211_local *local;
2513 	struct sk_buff *skb;
2514 
2515 	if (WARN_ON(vif->type != NL80211_IFTYPE_STATION))
2516 		return NULL;
2517 
2518 	sdata = vif_to_sdata(vif);
2519 	ifmgd = &sdata->u.mgd;
2520 	local = sdata->local;
2521 
2522 	skb = dev_alloc_skb(local->hw.extra_tx_headroom + sizeof(*pspoll));
2523 	if (!skb)
2524 		return NULL;
2525 
2526 	skb_reserve(skb, local->hw.extra_tx_headroom);
2527 
2528 	pspoll = (struct ieee80211_pspoll *) skb_put(skb, sizeof(*pspoll));
2529 	memset(pspoll, 0, sizeof(*pspoll));
2530 	pspoll->frame_control = cpu_to_le16(IEEE80211_FTYPE_CTL |
2531 					    IEEE80211_STYPE_PSPOLL);
2532 	pspoll->aid = cpu_to_le16(ifmgd->aid);
2533 
2534 	/* aid in PS-Poll has its two MSBs each set to 1 */
2535 	pspoll->aid |= cpu_to_le16(1 << 15 | 1 << 14);
2536 
2537 	memcpy(pspoll->bssid, ifmgd->bssid, ETH_ALEN);
2538 	memcpy(pspoll->ta, vif->addr, ETH_ALEN);
2539 
2540 	return skb;
2541 }
2542 EXPORT_SYMBOL(ieee80211_pspoll_get);
2543 
2544 struct sk_buff *ieee80211_nullfunc_get(struct ieee80211_hw *hw,
2545 				       struct ieee80211_vif *vif)
2546 {
2547 	struct ieee80211_hdr_3addr *nullfunc;
2548 	struct ieee80211_sub_if_data *sdata;
2549 	struct ieee80211_if_managed *ifmgd;
2550 	struct ieee80211_local *local;
2551 	struct sk_buff *skb;
2552 
2553 	if (WARN_ON(vif->type != NL80211_IFTYPE_STATION))
2554 		return NULL;
2555 
2556 	sdata = vif_to_sdata(vif);
2557 	ifmgd = &sdata->u.mgd;
2558 	local = sdata->local;
2559 
2560 	skb = dev_alloc_skb(local->hw.extra_tx_headroom + sizeof(*nullfunc));
2561 	if (!skb)
2562 		return NULL;
2563 
2564 	skb_reserve(skb, local->hw.extra_tx_headroom);
2565 
2566 	nullfunc = (struct ieee80211_hdr_3addr *) skb_put(skb,
2567 							  sizeof(*nullfunc));
2568 	memset(nullfunc, 0, sizeof(*nullfunc));
2569 	nullfunc->frame_control = cpu_to_le16(IEEE80211_FTYPE_DATA |
2570 					      IEEE80211_STYPE_NULLFUNC |
2571 					      IEEE80211_FCTL_TODS);
2572 	memcpy(nullfunc->addr1, ifmgd->bssid, ETH_ALEN);
2573 	memcpy(nullfunc->addr2, vif->addr, ETH_ALEN);
2574 	memcpy(nullfunc->addr3, ifmgd->bssid, ETH_ALEN);
2575 
2576 	return skb;
2577 }
2578 EXPORT_SYMBOL(ieee80211_nullfunc_get);
2579 
2580 struct sk_buff *ieee80211_probereq_get(struct ieee80211_hw *hw,
2581 				       struct ieee80211_vif *vif,
2582 				       const u8 *ssid, size_t ssid_len,
2583 				       const u8 *ie, size_t ie_len)
2584 {
2585 	struct ieee80211_sub_if_data *sdata;
2586 	struct ieee80211_local *local;
2587 	struct ieee80211_hdr_3addr *hdr;
2588 	struct sk_buff *skb;
2589 	size_t ie_ssid_len;
2590 	u8 *pos;
2591 
2592 	sdata = vif_to_sdata(vif);
2593 	local = sdata->local;
2594 	ie_ssid_len = 2 + ssid_len;
2595 
2596 	skb = dev_alloc_skb(local->hw.extra_tx_headroom + sizeof(*hdr) +
2597 			    ie_ssid_len + ie_len);
2598 	if (!skb)
2599 		return NULL;
2600 
2601 	skb_reserve(skb, local->hw.extra_tx_headroom);
2602 
2603 	hdr = (struct ieee80211_hdr_3addr *) skb_put(skb, sizeof(*hdr));
2604 	memset(hdr, 0, sizeof(*hdr));
2605 	hdr->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
2606 					 IEEE80211_STYPE_PROBE_REQ);
2607 	memset(hdr->addr1, 0xff, ETH_ALEN);
2608 	memcpy(hdr->addr2, vif->addr, ETH_ALEN);
2609 	memset(hdr->addr3, 0xff, ETH_ALEN);
2610 
2611 	pos = skb_put(skb, ie_ssid_len);
2612 	*pos++ = WLAN_EID_SSID;
2613 	*pos++ = ssid_len;
2614 	if (ssid_len)
2615 		memcpy(pos, ssid, ssid_len);
2616 	pos += ssid_len;
2617 
2618 	if (ie) {
2619 		pos = skb_put(skb, ie_len);
2620 		memcpy(pos, ie, ie_len);
2621 	}
2622 
2623 	return skb;
2624 }
2625 EXPORT_SYMBOL(ieee80211_probereq_get);
2626 
2627 void ieee80211_rts_get(struct ieee80211_hw *hw, struct ieee80211_vif *vif,
2628 		       const void *frame, size_t frame_len,
2629 		       const struct ieee80211_tx_info *frame_txctl,
2630 		       struct ieee80211_rts *rts)
2631 {
2632 	const struct ieee80211_hdr *hdr = frame;
2633 
2634 	rts->frame_control =
2635 	    cpu_to_le16(IEEE80211_FTYPE_CTL | IEEE80211_STYPE_RTS);
2636 	rts->duration = ieee80211_rts_duration(hw, vif, frame_len,
2637 					       frame_txctl);
2638 	memcpy(rts->ra, hdr->addr1, sizeof(rts->ra));
2639 	memcpy(rts->ta, hdr->addr2, sizeof(rts->ta));
2640 }
2641 EXPORT_SYMBOL(ieee80211_rts_get);
2642 
2643 void ieee80211_ctstoself_get(struct ieee80211_hw *hw, struct ieee80211_vif *vif,
2644 			     const void *frame, size_t frame_len,
2645 			     const struct ieee80211_tx_info *frame_txctl,
2646 			     struct ieee80211_cts *cts)
2647 {
2648 	const struct ieee80211_hdr *hdr = frame;
2649 
2650 	cts->frame_control =
2651 	    cpu_to_le16(IEEE80211_FTYPE_CTL | IEEE80211_STYPE_CTS);
2652 	cts->duration = ieee80211_ctstoself_duration(hw, vif,
2653 						     frame_len, frame_txctl);
2654 	memcpy(cts->ra, hdr->addr1, sizeof(cts->ra));
2655 }
2656 EXPORT_SYMBOL(ieee80211_ctstoself_get);
2657 
2658 struct sk_buff *
2659 ieee80211_get_buffered_bc(struct ieee80211_hw *hw,
2660 			  struct ieee80211_vif *vif)
2661 {
2662 	struct ieee80211_local *local = hw_to_local(hw);
2663 	struct sk_buff *skb = NULL;
2664 	struct ieee80211_tx_data tx;
2665 	struct ieee80211_sub_if_data *sdata;
2666 	struct ieee80211_if_ap *bss = NULL;
2667 	struct beacon_data *beacon;
2668 	struct ieee80211_tx_info *info;
2669 
2670 	sdata = vif_to_sdata(vif);
2671 	bss = &sdata->u.ap;
2672 
2673 	rcu_read_lock();
2674 	beacon = rcu_dereference(bss->beacon);
2675 
2676 	if (sdata->vif.type != NL80211_IFTYPE_AP || !beacon || !beacon->head)
2677 		goto out;
2678 
2679 	if (bss->dtim_count != 0 || !bss->dtim_bc_mc)
2680 		goto out; /* send buffered bc/mc only after DTIM beacon */
2681 
2682 	while (1) {
2683 		skb = skb_dequeue(&bss->ps_bc_buf);
2684 		if (!skb)
2685 			goto out;
2686 		local->total_ps_buffered--;
2687 
2688 		if (!skb_queue_empty(&bss->ps_bc_buf) && skb->len >= 2) {
2689 			struct ieee80211_hdr *hdr =
2690 				(struct ieee80211_hdr *) skb->data;
2691 			/* more buffered multicast/broadcast frames ==> set
2692 			 * MoreData flag in IEEE 802.11 header to inform PS
2693 			 * STAs */
2694 			hdr->frame_control |=
2695 				cpu_to_le16(IEEE80211_FCTL_MOREDATA);
2696 		}
2697 
2698 		if (!ieee80211_tx_prepare(sdata, &tx, skb))
2699 			break;
2700 		dev_kfree_skb_any(skb);
2701 	}
2702 
2703 	info = IEEE80211_SKB_CB(skb);
2704 
2705 	tx.flags |= IEEE80211_TX_PS_BUFFERED;
2706 	tx.channel = local->hw.conf.channel;
2707 	info->band = tx.channel->band;
2708 
2709 	if (invoke_tx_handlers(&tx))
2710 		skb = NULL;
2711  out:
2712 	rcu_read_unlock();
2713 
2714 	return skb;
2715 }
2716 EXPORT_SYMBOL(ieee80211_get_buffered_bc);
2717 
2718 void ieee80211_tx_skb_tid(struct ieee80211_sub_if_data *sdata,
2719 			  struct sk_buff *skb, int tid)
2720 {
2721 	int ac = ieee802_1d_to_ac[tid & 7];
2722 
2723 	skb_set_mac_header(skb, 0);
2724 	skb_set_network_header(skb, 0);
2725 	skb_set_transport_header(skb, 0);
2726 
2727 	skb_set_queue_mapping(skb, ac);
2728 	skb->priority = tid;
2729 
2730 	/*
2731 	 * The other path calling ieee80211_xmit is from the tasklet,
2732 	 * and while we can handle concurrent transmissions locking
2733 	 * requirements are that we do not come into tx with bhs on.
2734 	 */
2735 	local_bh_disable();
2736 	ieee80211_xmit(sdata, skb);
2737 	local_bh_enable();
2738 }
2739