xref: /openbmc/linux/net/mac80211/tx.c (revision ce932d0c5589e9766e089c22c66890dfc48fbd94)
1 /*
2  * Copyright 2002-2005, Instant802 Networks, Inc.
3  * Copyright 2005-2006, Devicescape Software, Inc.
4  * Copyright 2006-2007	Jiri Benc <jbenc@suse.cz>
5  * Copyright 2007	Johannes Berg <johannes@sipsolutions.net>
6  *
7  * This program is free software; you can redistribute it and/or modify
8  * it under the terms of the GNU General Public License version 2 as
9  * published by the Free Software Foundation.
10  *
11  *
12  * Transmit and frame generation functions.
13  */
14 
15 #include <linux/kernel.h>
16 #include <linux/slab.h>
17 #include <linux/skbuff.h>
18 #include <linux/etherdevice.h>
19 #include <linux/bitmap.h>
20 #include <linux/rcupdate.h>
21 #include <linux/export.h>
22 #include <net/net_namespace.h>
23 #include <net/ieee80211_radiotap.h>
24 #include <net/cfg80211.h>
25 #include <net/mac80211.h>
26 #include <asm/unaligned.h>
27 
28 #include "ieee80211_i.h"
29 #include "driver-ops.h"
30 #include "led.h"
31 #include "mesh.h"
32 #include "wep.h"
33 #include "wpa.h"
34 #include "wme.h"
35 #include "rate.h"
36 
37 /* misc utils */
38 
39 static __le16 ieee80211_duration(struct ieee80211_tx_data *tx,
40 				 struct sk_buff *skb, int group_addr,
41 				 int next_frag_len)
42 {
43 	int rate, mrate, erp, dur, i;
44 	struct ieee80211_rate *txrate;
45 	struct ieee80211_local *local = tx->local;
46 	struct ieee80211_supported_band *sband;
47 	struct ieee80211_hdr *hdr;
48 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
49 
50 	/* assume HW handles this */
51 	if (info->control.rates[0].flags & IEEE80211_TX_RC_MCS)
52 		return 0;
53 
54 	/* uh huh? */
55 	if (WARN_ON_ONCE(info->control.rates[0].idx < 0))
56 		return 0;
57 
58 	sband = local->hw.wiphy->bands[tx->channel->band];
59 	txrate = &sband->bitrates[info->control.rates[0].idx];
60 
61 	erp = txrate->flags & IEEE80211_RATE_ERP_G;
62 
63 	/*
64 	 * data and mgmt (except PS Poll):
65 	 * - during CFP: 32768
66 	 * - during contention period:
67 	 *   if addr1 is group address: 0
68 	 *   if more fragments = 0 and addr1 is individual address: time to
69 	 *      transmit one ACK plus SIFS
70 	 *   if more fragments = 1 and addr1 is individual address: time to
71 	 *      transmit next fragment plus 2 x ACK plus 3 x SIFS
72 	 *
73 	 * IEEE 802.11, 9.6:
74 	 * - control response frame (CTS or ACK) shall be transmitted using the
75 	 *   same rate as the immediately previous frame in the frame exchange
76 	 *   sequence, if this rate belongs to the PHY mandatory rates, or else
77 	 *   at the highest possible rate belonging to the PHY rates in the
78 	 *   BSSBasicRateSet
79 	 */
80 	hdr = (struct ieee80211_hdr *)skb->data;
81 	if (ieee80211_is_ctl(hdr->frame_control)) {
82 		/* TODO: These control frames are not currently sent by
83 		 * mac80211, but should they be implemented, this function
84 		 * needs to be updated to support duration field calculation.
85 		 *
86 		 * RTS: time needed to transmit pending data/mgmt frame plus
87 		 *    one CTS frame plus one ACK frame plus 3 x SIFS
88 		 * CTS: duration of immediately previous RTS minus time
89 		 *    required to transmit CTS and its SIFS
90 		 * ACK: 0 if immediately previous directed data/mgmt had
91 		 *    more=0, with more=1 duration in ACK frame is duration
92 		 *    from previous frame minus time needed to transmit ACK
93 		 *    and its SIFS
94 		 * PS Poll: BIT(15) | BIT(14) | aid
95 		 */
96 		return 0;
97 	}
98 
99 	/* data/mgmt */
100 	if (0 /* FIX: data/mgmt during CFP */)
101 		return cpu_to_le16(32768);
102 
103 	if (group_addr) /* Group address as the destination - no ACK */
104 		return 0;
105 
106 	/* Individual destination address:
107 	 * IEEE 802.11, Ch. 9.6 (after IEEE 802.11g changes)
108 	 * CTS and ACK frames shall be transmitted using the highest rate in
109 	 * basic rate set that is less than or equal to the rate of the
110 	 * immediately previous frame and that is using the same modulation
111 	 * (CCK or OFDM). If no basic rate set matches with these requirements,
112 	 * the highest mandatory rate of the PHY that is less than or equal to
113 	 * the rate of the previous frame is used.
114 	 * Mandatory rates for IEEE 802.11g PHY: 1, 2, 5.5, 11, 6, 12, 24 Mbps
115 	 */
116 	rate = -1;
117 	/* use lowest available if everything fails */
118 	mrate = sband->bitrates[0].bitrate;
119 	for (i = 0; i < sband->n_bitrates; i++) {
120 		struct ieee80211_rate *r = &sband->bitrates[i];
121 
122 		if (r->bitrate > txrate->bitrate)
123 			break;
124 
125 		if (tx->sdata->vif.bss_conf.basic_rates & BIT(i))
126 			rate = r->bitrate;
127 
128 		switch (sband->band) {
129 		case IEEE80211_BAND_2GHZ: {
130 			u32 flag;
131 			if (tx->sdata->flags & IEEE80211_SDATA_OPERATING_GMODE)
132 				flag = IEEE80211_RATE_MANDATORY_G;
133 			else
134 				flag = IEEE80211_RATE_MANDATORY_B;
135 			if (r->flags & flag)
136 				mrate = r->bitrate;
137 			break;
138 		}
139 		case IEEE80211_BAND_5GHZ:
140 			if (r->flags & IEEE80211_RATE_MANDATORY_A)
141 				mrate = r->bitrate;
142 			break;
143 		case IEEE80211_NUM_BANDS:
144 			WARN_ON(1);
145 			break;
146 		}
147 	}
148 	if (rate == -1) {
149 		/* No matching basic rate found; use highest suitable mandatory
150 		 * PHY rate */
151 		rate = mrate;
152 	}
153 
154 	/* Don't calculate ACKs for QoS Frames with NoAck Policy set */
155 	if (ieee80211_is_data_qos(hdr->frame_control) &&
156 	    *(ieee80211_get_qos_ctl(hdr)) | IEEE80211_QOS_CTL_ACK_POLICY_NOACK)
157 		dur = 0;
158 	else
159 		/* Time needed to transmit ACK
160 		 * (10 bytes + 4-byte FCS = 112 bits) plus SIFS; rounded up
161 		 * to closest integer */
162 		dur = ieee80211_frame_duration(local, 10, rate, erp,
163 				tx->sdata->vif.bss_conf.use_short_preamble);
164 
165 	if (next_frag_len) {
166 		/* Frame is fragmented: duration increases with time needed to
167 		 * transmit next fragment plus ACK and 2 x SIFS. */
168 		dur *= 2; /* ACK + SIFS */
169 		/* next fragment */
170 		dur += ieee80211_frame_duration(local, next_frag_len,
171 				txrate->bitrate, erp,
172 				tx->sdata->vif.bss_conf.use_short_preamble);
173 	}
174 
175 	return cpu_to_le16(dur);
176 }
177 
178 static inline int is_ieee80211_device(struct ieee80211_local *local,
179 				      struct net_device *dev)
180 {
181 	return local == wdev_priv(dev->ieee80211_ptr);
182 }
183 
184 /* tx handlers */
185 static ieee80211_tx_result debug_noinline
186 ieee80211_tx_h_dynamic_ps(struct ieee80211_tx_data *tx)
187 {
188 	struct ieee80211_local *local = tx->local;
189 	struct ieee80211_if_managed *ifmgd;
190 
191 	/* driver doesn't support power save */
192 	if (!(local->hw.flags & IEEE80211_HW_SUPPORTS_PS))
193 		return TX_CONTINUE;
194 
195 	/* hardware does dynamic power save */
196 	if (local->hw.flags & IEEE80211_HW_SUPPORTS_DYNAMIC_PS)
197 		return TX_CONTINUE;
198 
199 	/* dynamic power save disabled */
200 	if (local->hw.conf.dynamic_ps_timeout <= 0)
201 		return TX_CONTINUE;
202 
203 	/* we are scanning, don't enable power save */
204 	if (local->scanning)
205 		return TX_CONTINUE;
206 
207 	if (!local->ps_sdata)
208 		return TX_CONTINUE;
209 
210 	/* No point if we're going to suspend */
211 	if (local->quiescing)
212 		return TX_CONTINUE;
213 
214 	/* dynamic ps is supported only in managed mode */
215 	if (tx->sdata->vif.type != NL80211_IFTYPE_STATION)
216 		return TX_CONTINUE;
217 
218 	ifmgd = &tx->sdata->u.mgd;
219 
220 	/*
221 	 * Don't wakeup from power save if u-apsd is enabled, voip ac has
222 	 * u-apsd enabled and the frame is in voip class. This effectively
223 	 * means that even if all access categories have u-apsd enabled, in
224 	 * practise u-apsd is only used with the voip ac. This is a
225 	 * workaround for the case when received voip class packets do not
226 	 * have correct qos tag for some reason, due the network or the
227 	 * peer application.
228 	 *
229 	 * Note: ifmgd->uapsd_queues access is racy here. If the value is
230 	 * changed via debugfs, user needs to reassociate manually to have
231 	 * everything in sync.
232 	 */
233 	if ((ifmgd->flags & IEEE80211_STA_UAPSD_ENABLED)
234 	    && (ifmgd->uapsd_queues & IEEE80211_WMM_IE_STA_QOSINFO_AC_VO)
235 	    && skb_get_queue_mapping(tx->skb) == 0)
236 		return TX_CONTINUE;
237 
238 	if (local->hw.conf.flags & IEEE80211_CONF_PS) {
239 		ieee80211_stop_queues_by_reason(&local->hw,
240 						IEEE80211_QUEUE_STOP_REASON_PS);
241 		ifmgd->flags &= ~IEEE80211_STA_NULLFUNC_ACKED;
242 		ieee80211_queue_work(&local->hw,
243 				     &local->dynamic_ps_disable_work);
244 	}
245 
246 	/* Don't restart the timer if we're not disassociated */
247 	if (!ifmgd->associated)
248 		return TX_CONTINUE;
249 
250 	mod_timer(&local->dynamic_ps_timer, jiffies +
251 		  msecs_to_jiffies(local->hw.conf.dynamic_ps_timeout));
252 
253 	return TX_CONTINUE;
254 }
255 
256 static ieee80211_tx_result debug_noinline
257 ieee80211_tx_h_check_assoc(struct ieee80211_tx_data *tx)
258 {
259 
260 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)tx->skb->data;
261 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(tx->skb);
262 	bool assoc = false;
263 
264 	if (unlikely(info->flags & IEEE80211_TX_CTL_INJECTED))
265 		return TX_CONTINUE;
266 
267 	if (unlikely(test_bit(SCAN_SW_SCANNING, &tx->local->scanning)) &&
268 	    test_bit(SDATA_STATE_OFFCHANNEL, &tx->sdata->state) &&
269 	    !ieee80211_is_probe_req(hdr->frame_control) &&
270 	    !ieee80211_is_nullfunc(hdr->frame_control))
271 		/*
272 		 * When software scanning only nullfunc frames (to notify
273 		 * the sleep state to the AP) and probe requests (for the
274 		 * active scan) are allowed, all other frames should not be
275 		 * sent and we should not get here, but if we do
276 		 * nonetheless, drop them to avoid sending them
277 		 * off-channel. See the link below and
278 		 * ieee80211_start_scan() for more.
279 		 *
280 		 * http://article.gmane.org/gmane.linux.kernel.wireless.general/30089
281 		 */
282 		return TX_DROP;
283 
284 	if (tx->sdata->vif.type == NL80211_IFTYPE_WDS)
285 		return TX_CONTINUE;
286 
287 	if (tx->sdata->vif.type == NL80211_IFTYPE_MESH_POINT)
288 		return TX_CONTINUE;
289 
290 	if (tx->flags & IEEE80211_TX_PS_BUFFERED)
291 		return TX_CONTINUE;
292 
293 	if (tx->sta)
294 		assoc = test_sta_flag(tx->sta, WLAN_STA_ASSOC);
295 
296 	if (likely(tx->flags & IEEE80211_TX_UNICAST)) {
297 		if (unlikely(!assoc &&
298 			     ieee80211_is_data(hdr->frame_control))) {
299 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG
300 			printk(KERN_DEBUG "%s: dropped data frame to not "
301 			       "associated station %pM\n",
302 			       tx->sdata->name, hdr->addr1);
303 #endif /* CONFIG_MAC80211_VERBOSE_DEBUG */
304 			I802_DEBUG_INC(tx->local->tx_handlers_drop_not_assoc);
305 			return TX_DROP;
306 		}
307 	} else if (unlikely(tx->sdata->vif.type == NL80211_IFTYPE_AP &&
308 			    ieee80211_is_data(hdr->frame_control) &&
309 			    !atomic_read(&tx->sdata->u.ap.num_sta_authorized))) {
310 		/*
311 		 * No associated STAs - no need to send multicast
312 		 * frames.
313 		 */
314 		return TX_DROP;
315 	}
316 
317 	return TX_CONTINUE;
318 }
319 
320 /* This function is called whenever the AP is about to exceed the maximum limit
321  * of buffered frames for power saving STAs. This situation should not really
322  * happen often during normal operation, so dropping the oldest buffered packet
323  * from each queue should be OK to make some room for new frames. */
324 static void purge_old_ps_buffers(struct ieee80211_local *local)
325 {
326 	int total = 0, purged = 0;
327 	struct sk_buff *skb;
328 	struct ieee80211_sub_if_data *sdata;
329 	struct sta_info *sta;
330 
331 	/*
332 	 * virtual interfaces are protected by RCU
333 	 */
334 	rcu_read_lock();
335 
336 	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
337 		struct ieee80211_if_ap *ap;
338 		if (sdata->vif.type != NL80211_IFTYPE_AP)
339 			continue;
340 		ap = &sdata->u.ap;
341 		skb = skb_dequeue(&ap->ps_bc_buf);
342 		if (skb) {
343 			purged++;
344 			dev_kfree_skb(skb);
345 		}
346 		total += skb_queue_len(&ap->ps_bc_buf);
347 	}
348 
349 	/*
350 	 * Drop one frame from each station from the lowest-priority
351 	 * AC that has frames at all.
352 	 */
353 	list_for_each_entry_rcu(sta, &local->sta_list, list) {
354 		int ac;
355 
356 		for (ac = IEEE80211_AC_BK; ac >= IEEE80211_AC_VO; ac--) {
357 			skb = skb_dequeue(&sta->ps_tx_buf[ac]);
358 			total += skb_queue_len(&sta->ps_tx_buf[ac]);
359 			if (skb) {
360 				purged++;
361 				dev_kfree_skb(skb);
362 				break;
363 			}
364 		}
365 	}
366 
367 	rcu_read_unlock();
368 
369 	local->total_ps_buffered = total;
370 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
371 	wiphy_debug(local->hw.wiphy, "PS buffers full - purged %d frames\n",
372 		    purged);
373 #endif
374 }
375 
376 static ieee80211_tx_result
377 ieee80211_tx_h_multicast_ps_buf(struct ieee80211_tx_data *tx)
378 {
379 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(tx->skb);
380 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)tx->skb->data;
381 
382 	/*
383 	 * broadcast/multicast frame
384 	 *
385 	 * If any of the associated stations is in power save mode,
386 	 * the frame is buffered to be sent after DTIM beacon frame.
387 	 * This is done either by the hardware or us.
388 	 */
389 
390 	/* powersaving STAs only in AP/VLAN mode */
391 	if (!tx->sdata->bss)
392 		return TX_CONTINUE;
393 
394 	/* no buffering for ordered frames */
395 	if (ieee80211_has_order(hdr->frame_control))
396 		return TX_CONTINUE;
397 
398 	/* no stations in PS mode */
399 	if (!atomic_read(&tx->sdata->bss->num_sta_ps))
400 		return TX_CONTINUE;
401 
402 	info->flags |= IEEE80211_TX_CTL_SEND_AFTER_DTIM;
403 
404 	/* device releases frame after DTIM beacon */
405 	if (!(tx->local->hw.flags & IEEE80211_HW_HOST_BROADCAST_PS_BUFFERING))
406 		return TX_CONTINUE;
407 
408 	/* buffered in mac80211 */
409 	if (tx->local->total_ps_buffered >= TOTAL_MAX_TX_BUFFER)
410 		purge_old_ps_buffers(tx->local);
411 
412 	if (skb_queue_len(&tx->sdata->bss->ps_bc_buf) >= AP_MAX_BC_BUFFER) {
413 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
414 		if (net_ratelimit())
415 			printk(KERN_DEBUG "%s: BC TX buffer full - dropping the oldest frame\n",
416 			       tx->sdata->name);
417 #endif
418 		dev_kfree_skb(skb_dequeue(&tx->sdata->bss->ps_bc_buf));
419 	} else
420 		tx->local->total_ps_buffered++;
421 
422 	skb_queue_tail(&tx->sdata->bss->ps_bc_buf, tx->skb);
423 
424 	return TX_QUEUED;
425 }
426 
427 static int ieee80211_use_mfp(__le16 fc, struct sta_info *sta,
428 			     struct sk_buff *skb)
429 {
430 	if (!ieee80211_is_mgmt(fc))
431 		return 0;
432 
433 	if (sta == NULL || !test_sta_flag(sta, WLAN_STA_MFP))
434 		return 0;
435 
436 	if (!ieee80211_is_robust_mgmt_frame((struct ieee80211_hdr *)
437 					    skb->data))
438 		return 0;
439 
440 	return 1;
441 }
442 
443 static ieee80211_tx_result
444 ieee80211_tx_h_unicast_ps_buf(struct ieee80211_tx_data *tx)
445 {
446 	struct sta_info *sta = tx->sta;
447 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(tx->skb);
448 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)tx->skb->data;
449 	struct ieee80211_local *local = tx->local;
450 
451 	if (unlikely(!sta))
452 		return TX_CONTINUE;
453 
454 	if (unlikely((test_sta_flag(sta, WLAN_STA_PS_STA) ||
455 		      test_sta_flag(sta, WLAN_STA_PS_DRIVER)) &&
456 		     !(info->flags & IEEE80211_TX_CTL_NO_PS_BUFFER))) {
457 		int ac = skb_get_queue_mapping(tx->skb);
458 
459 		/* only deauth, disassoc and action are bufferable MMPDUs */
460 		if (ieee80211_is_mgmt(hdr->frame_control) &&
461 		    !ieee80211_is_deauth(hdr->frame_control) &&
462 		    !ieee80211_is_disassoc(hdr->frame_control) &&
463 		    !ieee80211_is_action(hdr->frame_control)) {
464 			info->flags |= IEEE80211_TX_CTL_NO_PS_BUFFER;
465 			return TX_CONTINUE;
466 		}
467 
468 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
469 		printk(KERN_DEBUG "STA %pM aid %d: PS buffer for AC %d\n",
470 		       sta->sta.addr, sta->sta.aid, ac);
471 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
472 		if (tx->local->total_ps_buffered >= TOTAL_MAX_TX_BUFFER)
473 			purge_old_ps_buffers(tx->local);
474 		if (skb_queue_len(&sta->ps_tx_buf[ac]) >= STA_MAX_TX_BUFFER) {
475 			struct sk_buff *old = skb_dequeue(&sta->ps_tx_buf[ac]);
476 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
477 			if (net_ratelimit())
478 				printk(KERN_DEBUG "%s: STA %pM TX buffer for "
479 				       "AC %d full - dropping oldest frame\n",
480 				       tx->sdata->name, sta->sta.addr, ac);
481 #endif
482 			dev_kfree_skb(old);
483 		} else
484 			tx->local->total_ps_buffered++;
485 
486 		info->control.jiffies = jiffies;
487 		info->control.vif = &tx->sdata->vif;
488 		info->flags |= IEEE80211_TX_INTFL_NEED_TXPROCESSING;
489 		skb_queue_tail(&sta->ps_tx_buf[ac], tx->skb);
490 
491 		if (!timer_pending(&local->sta_cleanup))
492 			mod_timer(&local->sta_cleanup,
493 				  round_jiffies(jiffies +
494 						STA_INFO_CLEANUP_INTERVAL));
495 
496 		/*
497 		 * We queued up some frames, so the TIM bit might
498 		 * need to be set, recalculate it.
499 		 */
500 		sta_info_recalc_tim(sta);
501 
502 		return TX_QUEUED;
503 	}
504 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
505 	else if (unlikely(test_sta_flag(sta, WLAN_STA_PS_STA))) {
506 		printk(KERN_DEBUG
507 		       "%s: STA %pM in PS mode, but polling/in SP -> send frame\n",
508 		       tx->sdata->name, sta->sta.addr);
509 	}
510 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
511 
512 	return TX_CONTINUE;
513 }
514 
515 static ieee80211_tx_result debug_noinline
516 ieee80211_tx_h_ps_buf(struct ieee80211_tx_data *tx)
517 {
518 	if (unlikely(tx->flags & IEEE80211_TX_PS_BUFFERED))
519 		return TX_CONTINUE;
520 
521 	if (tx->flags & IEEE80211_TX_UNICAST)
522 		return ieee80211_tx_h_unicast_ps_buf(tx);
523 	else
524 		return ieee80211_tx_h_multicast_ps_buf(tx);
525 }
526 
527 static ieee80211_tx_result debug_noinline
528 ieee80211_tx_h_check_control_port_protocol(struct ieee80211_tx_data *tx)
529 {
530 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(tx->skb);
531 
532 	if (unlikely(tx->sdata->control_port_protocol == tx->skb->protocol &&
533 		     tx->sdata->control_port_no_encrypt))
534 		info->flags |= IEEE80211_TX_INTFL_DONT_ENCRYPT;
535 
536 	return TX_CONTINUE;
537 }
538 
539 static ieee80211_tx_result debug_noinline
540 ieee80211_tx_h_select_key(struct ieee80211_tx_data *tx)
541 {
542 	struct ieee80211_key *key = NULL;
543 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(tx->skb);
544 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)tx->skb->data;
545 
546 	if (unlikely(info->flags & IEEE80211_TX_INTFL_DONT_ENCRYPT))
547 		tx->key = NULL;
548 	else if (tx->sta && (key = rcu_dereference(tx->sta->ptk)))
549 		tx->key = key;
550 	else if (ieee80211_is_mgmt(hdr->frame_control) &&
551 		 is_multicast_ether_addr(hdr->addr1) &&
552 		 ieee80211_is_robust_mgmt_frame(hdr) &&
553 		 (key = rcu_dereference(tx->sdata->default_mgmt_key)))
554 		tx->key = key;
555 	else if (is_multicast_ether_addr(hdr->addr1) &&
556 		 (key = rcu_dereference(tx->sdata->default_multicast_key)))
557 		tx->key = key;
558 	else if (!is_multicast_ether_addr(hdr->addr1) &&
559 		 (key = rcu_dereference(tx->sdata->default_unicast_key)))
560 		tx->key = key;
561 	else if (tx->sdata->drop_unencrypted &&
562 		 (tx->skb->protocol != tx->sdata->control_port_protocol) &&
563 		 !(info->flags & IEEE80211_TX_CTL_INJECTED) &&
564 		 (!ieee80211_is_robust_mgmt_frame(hdr) ||
565 		  (ieee80211_is_action(hdr->frame_control) &&
566 		   tx->sta && test_sta_flag(tx->sta, WLAN_STA_MFP)))) {
567 		I802_DEBUG_INC(tx->local->tx_handlers_drop_unencrypted);
568 		return TX_DROP;
569 	} else
570 		tx->key = NULL;
571 
572 	if (tx->key) {
573 		bool skip_hw = false;
574 
575 		tx->key->tx_rx_count++;
576 		/* TODO: add threshold stuff again */
577 
578 		switch (tx->key->conf.cipher) {
579 		case WLAN_CIPHER_SUITE_WEP40:
580 		case WLAN_CIPHER_SUITE_WEP104:
581 		case WLAN_CIPHER_SUITE_TKIP:
582 			if (!ieee80211_is_data_present(hdr->frame_control))
583 				tx->key = NULL;
584 			break;
585 		case WLAN_CIPHER_SUITE_CCMP:
586 			if (!ieee80211_is_data_present(hdr->frame_control) &&
587 			    !ieee80211_use_mfp(hdr->frame_control, tx->sta,
588 					       tx->skb))
589 				tx->key = NULL;
590 			else
591 				skip_hw = (tx->key->conf.flags &
592 					   IEEE80211_KEY_FLAG_SW_MGMT) &&
593 					ieee80211_is_mgmt(hdr->frame_control);
594 			break;
595 		case WLAN_CIPHER_SUITE_AES_CMAC:
596 			if (!ieee80211_is_mgmt(hdr->frame_control))
597 				tx->key = NULL;
598 			break;
599 		}
600 
601 		if (unlikely(tx->key && tx->key->flags & KEY_FLAG_TAINTED))
602 			return TX_DROP;
603 
604 		if (!skip_hw && tx->key &&
605 		    tx->key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE)
606 			info->control.hw_key = &tx->key->conf;
607 	}
608 
609 	return TX_CONTINUE;
610 }
611 
612 static ieee80211_tx_result debug_noinline
613 ieee80211_tx_h_rate_ctrl(struct ieee80211_tx_data *tx)
614 {
615 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(tx->skb);
616 	struct ieee80211_hdr *hdr = (void *)tx->skb->data;
617 	struct ieee80211_supported_band *sband;
618 	struct ieee80211_rate *rate;
619 	int i;
620 	u32 len;
621 	bool inval = false, rts = false, short_preamble = false;
622 	struct ieee80211_tx_rate_control txrc;
623 	bool assoc = false;
624 
625 	memset(&txrc, 0, sizeof(txrc));
626 
627 	sband = tx->local->hw.wiphy->bands[tx->channel->band];
628 
629 	len = min_t(u32, tx->skb->len + FCS_LEN,
630 			 tx->local->hw.wiphy->frag_threshold);
631 
632 	/* set up the tx rate control struct we give the RC algo */
633 	txrc.hw = &tx->local->hw;
634 	txrc.sband = sband;
635 	txrc.bss_conf = &tx->sdata->vif.bss_conf;
636 	txrc.skb = tx->skb;
637 	txrc.reported_rate.idx = -1;
638 	txrc.rate_idx_mask = tx->sdata->rc_rateidx_mask[tx->channel->band];
639 	if (txrc.rate_idx_mask == (1 << sband->n_bitrates) - 1)
640 		txrc.max_rate_idx = -1;
641 	else
642 		txrc.max_rate_idx = fls(txrc.rate_idx_mask) - 1;
643 	memcpy(txrc.rate_idx_mcs_mask,
644 	       tx->sdata->rc_rateidx_mcs_mask[tx->channel->band],
645 	       sizeof(txrc.rate_idx_mcs_mask));
646 	txrc.bss = (tx->sdata->vif.type == NL80211_IFTYPE_AP ||
647 		    tx->sdata->vif.type == NL80211_IFTYPE_MESH_POINT ||
648 		    tx->sdata->vif.type == NL80211_IFTYPE_ADHOC);
649 
650 	/* set up RTS protection if desired */
651 	if (len > tx->local->hw.wiphy->rts_threshold) {
652 		txrc.rts = rts = true;
653 	}
654 
655 	/*
656 	 * Use short preamble if the BSS can handle it, but not for
657 	 * management frames unless we know the receiver can handle
658 	 * that -- the management frame might be to a station that
659 	 * just wants a probe response.
660 	 */
661 	if (tx->sdata->vif.bss_conf.use_short_preamble &&
662 	    (ieee80211_is_data(hdr->frame_control) ||
663 	     (tx->sta && test_sta_flag(tx->sta, WLAN_STA_SHORT_PREAMBLE))))
664 		txrc.short_preamble = short_preamble = true;
665 
666 	if (tx->sta)
667 		assoc = test_sta_flag(tx->sta, WLAN_STA_ASSOC);
668 
669 	/*
670 	 * Lets not bother rate control if we're associated and cannot
671 	 * talk to the sta. This should not happen.
672 	 */
673 	if (WARN(test_bit(SCAN_SW_SCANNING, &tx->local->scanning) && assoc &&
674 		 !rate_usable_index_exists(sband, &tx->sta->sta),
675 		 "%s: Dropped data frame as no usable bitrate found while "
676 		 "scanning and associated. Target station: "
677 		 "%pM on %d GHz band\n",
678 		 tx->sdata->name, hdr->addr1,
679 		 tx->channel->band ? 5 : 2))
680 		return TX_DROP;
681 
682 	/*
683 	 * If we're associated with the sta at this point we know we can at
684 	 * least send the frame at the lowest bit rate.
685 	 */
686 	rate_control_get_rate(tx->sdata, tx->sta, &txrc);
687 
688 	if (unlikely(info->control.rates[0].idx < 0))
689 		return TX_DROP;
690 
691 	if (txrc.reported_rate.idx < 0) {
692 		txrc.reported_rate = info->control.rates[0];
693 		if (tx->sta && ieee80211_is_data(hdr->frame_control))
694 			tx->sta->last_tx_rate = txrc.reported_rate;
695 	} else if (tx->sta)
696 		tx->sta->last_tx_rate = txrc.reported_rate;
697 
698 	if (unlikely(!info->control.rates[0].count))
699 		info->control.rates[0].count = 1;
700 
701 	if (WARN_ON_ONCE((info->control.rates[0].count > 1) &&
702 			 (info->flags & IEEE80211_TX_CTL_NO_ACK)))
703 		info->control.rates[0].count = 1;
704 
705 	if (is_multicast_ether_addr(hdr->addr1)) {
706 		/*
707 		 * XXX: verify the rate is in the basic rateset
708 		 */
709 		return TX_CONTINUE;
710 	}
711 
712 	/*
713 	 * set up the RTS/CTS rate as the fastest basic rate
714 	 * that is not faster than the data rate
715 	 *
716 	 * XXX: Should this check all retry rates?
717 	 */
718 	if (!(info->control.rates[0].flags & IEEE80211_TX_RC_MCS)) {
719 		s8 baserate = 0;
720 
721 		rate = &sband->bitrates[info->control.rates[0].idx];
722 
723 		for (i = 0; i < sband->n_bitrates; i++) {
724 			/* must be a basic rate */
725 			if (!(tx->sdata->vif.bss_conf.basic_rates & BIT(i)))
726 				continue;
727 			/* must not be faster than the data rate */
728 			if (sband->bitrates[i].bitrate > rate->bitrate)
729 				continue;
730 			/* maximum */
731 			if (sband->bitrates[baserate].bitrate <
732 			     sband->bitrates[i].bitrate)
733 				baserate = i;
734 		}
735 
736 		info->control.rts_cts_rate_idx = baserate;
737 	}
738 
739 	for (i = 0; i < IEEE80211_TX_MAX_RATES; i++) {
740 		/*
741 		 * make sure there's no valid rate following
742 		 * an invalid one, just in case drivers don't
743 		 * take the API seriously to stop at -1.
744 		 */
745 		if (inval) {
746 			info->control.rates[i].idx = -1;
747 			continue;
748 		}
749 		if (info->control.rates[i].idx < 0) {
750 			inval = true;
751 			continue;
752 		}
753 
754 		/*
755 		 * For now assume MCS is already set up correctly, this
756 		 * needs to be fixed.
757 		 */
758 		if (info->control.rates[i].flags & IEEE80211_TX_RC_MCS) {
759 			WARN_ON(info->control.rates[i].idx > 76);
760 			continue;
761 		}
762 
763 		/* set up RTS protection if desired */
764 		if (rts)
765 			info->control.rates[i].flags |=
766 				IEEE80211_TX_RC_USE_RTS_CTS;
767 
768 		/* RC is busted */
769 		if (WARN_ON_ONCE(info->control.rates[i].idx >=
770 				 sband->n_bitrates)) {
771 			info->control.rates[i].idx = -1;
772 			continue;
773 		}
774 
775 		rate = &sband->bitrates[info->control.rates[i].idx];
776 
777 		/* set up short preamble */
778 		if (short_preamble &&
779 		    rate->flags & IEEE80211_RATE_SHORT_PREAMBLE)
780 			info->control.rates[i].flags |=
781 				IEEE80211_TX_RC_USE_SHORT_PREAMBLE;
782 
783 		/* set up G protection */
784 		if (!rts && tx->sdata->vif.bss_conf.use_cts_prot &&
785 		    rate->flags & IEEE80211_RATE_ERP_G)
786 			info->control.rates[i].flags |=
787 				IEEE80211_TX_RC_USE_CTS_PROTECT;
788 	}
789 
790 	return TX_CONTINUE;
791 }
792 
793 static ieee80211_tx_result debug_noinline
794 ieee80211_tx_h_sequence(struct ieee80211_tx_data *tx)
795 {
796 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(tx->skb);
797 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)tx->skb->data;
798 	u16 *seq;
799 	u8 *qc;
800 	int tid;
801 
802 	/*
803 	 * Packet injection may want to control the sequence
804 	 * number, if we have no matching interface then we
805 	 * neither assign one ourselves nor ask the driver to.
806 	 */
807 	if (unlikely(info->control.vif->type == NL80211_IFTYPE_MONITOR))
808 		return TX_CONTINUE;
809 
810 	if (unlikely(ieee80211_is_ctl(hdr->frame_control)))
811 		return TX_CONTINUE;
812 
813 	if (ieee80211_hdrlen(hdr->frame_control) < 24)
814 		return TX_CONTINUE;
815 
816 	if (ieee80211_is_qos_nullfunc(hdr->frame_control))
817 		return TX_CONTINUE;
818 
819 	/*
820 	 * Anything but QoS data that has a sequence number field
821 	 * (is long enough) gets a sequence number from the global
822 	 * counter.
823 	 */
824 	if (!ieee80211_is_data_qos(hdr->frame_control)) {
825 		/* driver should assign sequence number */
826 		info->flags |= IEEE80211_TX_CTL_ASSIGN_SEQ;
827 		/* for pure STA mode without beacons, we can do it */
828 		hdr->seq_ctrl = cpu_to_le16(tx->sdata->sequence_number);
829 		tx->sdata->sequence_number += 0x10;
830 		return TX_CONTINUE;
831 	}
832 
833 	/*
834 	 * This should be true for injected/management frames only, for
835 	 * management frames we have set the IEEE80211_TX_CTL_ASSIGN_SEQ
836 	 * above since they are not QoS-data frames.
837 	 */
838 	if (!tx->sta)
839 		return TX_CONTINUE;
840 
841 	/* include per-STA, per-TID sequence counter */
842 
843 	qc = ieee80211_get_qos_ctl(hdr);
844 	tid = *qc & IEEE80211_QOS_CTL_TID_MASK;
845 	seq = &tx->sta->tid_seq[tid];
846 
847 	hdr->seq_ctrl = cpu_to_le16(*seq);
848 
849 	/* Increase the sequence number. */
850 	*seq = (*seq + 0x10) & IEEE80211_SCTL_SEQ;
851 
852 	return TX_CONTINUE;
853 }
854 
855 static int ieee80211_fragment(struct ieee80211_tx_data *tx,
856 			      struct sk_buff *skb, int hdrlen,
857 			      int frag_threshold)
858 {
859 	struct ieee80211_local *local = tx->local;
860 	struct ieee80211_tx_info *info;
861 	struct sk_buff *tmp;
862 	int per_fragm = frag_threshold - hdrlen - FCS_LEN;
863 	int pos = hdrlen + per_fragm;
864 	int rem = skb->len - hdrlen - per_fragm;
865 
866 	if (WARN_ON(rem < 0))
867 		return -EINVAL;
868 
869 	/* first fragment was already added to queue by caller */
870 
871 	while (rem) {
872 		int fraglen = per_fragm;
873 
874 		if (fraglen > rem)
875 			fraglen = rem;
876 		rem -= fraglen;
877 		tmp = dev_alloc_skb(local->tx_headroom +
878 				    frag_threshold +
879 				    IEEE80211_ENCRYPT_HEADROOM +
880 				    IEEE80211_ENCRYPT_TAILROOM);
881 		if (!tmp)
882 			return -ENOMEM;
883 
884 		__skb_queue_tail(&tx->skbs, tmp);
885 
886 		skb_reserve(tmp, local->tx_headroom +
887 				 IEEE80211_ENCRYPT_HEADROOM);
888 		/* copy control information */
889 		memcpy(tmp->cb, skb->cb, sizeof(tmp->cb));
890 
891 		info = IEEE80211_SKB_CB(tmp);
892 		info->flags &= ~(IEEE80211_TX_CTL_CLEAR_PS_FILT |
893 				 IEEE80211_TX_CTL_FIRST_FRAGMENT);
894 
895 		if (rem)
896 			info->flags |= IEEE80211_TX_CTL_MORE_FRAMES;
897 
898 		skb_copy_queue_mapping(tmp, skb);
899 		tmp->priority = skb->priority;
900 		tmp->dev = skb->dev;
901 
902 		/* copy header and data */
903 		memcpy(skb_put(tmp, hdrlen), skb->data, hdrlen);
904 		memcpy(skb_put(tmp, fraglen), skb->data + pos, fraglen);
905 
906 		pos += fraglen;
907 	}
908 
909 	/* adjust first fragment's length */
910 	skb->len = hdrlen + per_fragm;
911 	return 0;
912 }
913 
914 static ieee80211_tx_result debug_noinline
915 ieee80211_tx_h_fragment(struct ieee80211_tx_data *tx)
916 {
917 	struct sk_buff *skb = tx->skb;
918 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
919 	struct ieee80211_hdr *hdr = (void *)skb->data;
920 	int frag_threshold = tx->local->hw.wiphy->frag_threshold;
921 	int hdrlen;
922 	int fragnum;
923 
924 	/* no matter what happens, tx->skb moves to tx->skbs */
925 	__skb_queue_tail(&tx->skbs, skb);
926 	tx->skb = NULL;
927 
928 	if (info->flags & IEEE80211_TX_CTL_DONTFRAG)
929 		return TX_CONTINUE;
930 
931 	if (tx->local->ops->set_frag_threshold)
932 		return TX_CONTINUE;
933 
934 	/*
935 	 * Warn when submitting a fragmented A-MPDU frame and drop it.
936 	 * This scenario is handled in ieee80211_tx_prepare but extra
937 	 * caution taken here as fragmented ampdu may cause Tx stop.
938 	 */
939 	if (WARN_ON(info->flags & IEEE80211_TX_CTL_AMPDU))
940 		return TX_DROP;
941 
942 	hdrlen = ieee80211_hdrlen(hdr->frame_control);
943 
944 	/* internal error, why isn't DONTFRAG set? */
945 	if (WARN_ON(skb->len + FCS_LEN <= frag_threshold))
946 		return TX_DROP;
947 
948 	/*
949 	 * Now fragment the frame. This will allocate all the fragments and
950 	 * chain them (using skb as the first fragment) to skb->next.
951 	 * During transmission, we will remove the successfully transmitted
952 	 * fragments from this list. When the low-level driver rejects one
953 	 * of the fragments then we will simply pretend to accept the skb
954 	 * but store it away as pending.
955 	 */
956 	if (ieee80211_fragment(tx, skb, hdrlen, frag_threshold))
957 		return TX_DROP;
958 
959 	/* update duration/seq/flags of fragments */
960 	fragnum = 0;
961 
962 	skb_queue_walk(&tx->skbs, skb) {
963 		int next_len;
964 		const __le16 morefrags = cpu_to_le16(IEEE80211_FCTL_MOREFRAGS);
965 
966 		hdr = (void *)skb->data;
967 		info = IEEE80211_SKB_CB(skb);
968 
969 		if (!skb_queue_is_last(&tx->skbs, skb)) {
970 			hdr->frame_control |= morefrags;
971 			/*
972 			 * No multi-rate retries for fragmented frames, that
973 			 * would completely throw off the NAV at other STAs.
974 			 */
975 			info->control.rates[1].idx = -1;
976 			info->control.rates[2].idx = -1;
977 			info->control.rates[3].idx = -1;
978 			info->control.rates[4].idx = -1;
979 			BUILD_BUG_ON(IEEE80211_TX_MAX_RATES != 5);
980 			info->flags &= ~IEEE80211_TX_CTL_RATE_CTRL_PROBE;
981 		} else {
982 			hdr->frame_control &= ~morefrags;
983 			next_len = 0;
984 		}
985 		hdr->seq_ctrl |= cpu_to_le16(fragnum & IEEE80211_SCTL_FRAG);
986 		fragnum++;
987 	}
988 
989 	return TX_CONTINUE;
990 }
991 
992 static ieee80211_tx_result debug_noinline
993 ieee80211_tx_h_stats(struct ieee80211_tx_data *tx)
994 {
995 	struct sk_buff *skb;
996 
997 	if (!tx->sta)
998 		return TX_CONTINUE;
999 
1000 	tx->sta->tx_packets++;
1001 	skb_queue_walk(&tx->skbs, skb) {
1002 		tx->sta->tx_fragments++;
1003 		tx->sta->tx_bytes += skb->len;
1004 	}
1005 
1006 	return TX_CONTINUE;
1007 }
1008 
1009 static ieee80211_tx_result debug_noinline
1010 ieee80211_tx_h_encrypt(struct ieee80211_tx_data *tx)
1011 {
1012 	if (!tx->key)
1013 		return TX_CONTINUE;
1014 
1015 	switch (tx->key->conf.cipher) {
1016 	case WLAN_CIPHER_SUITE_WEP40:
1017 	case WLAN_CIPHER_SUITE_WEP104:
1018 		return ieee80211_crypto_wep_encrypt(tx);
1019 	case WLAN_CIPHER_SUITE_TKIP:
1020 		return ieee80211_crypto_tkip_encrypt(tx);
1021 	case WLAN_CIPHER_SUITE_CCMP:
1022 		return ieee80211_crypto_ccmp_encrypt(tx);
1023 	case WLAN_CIPHER_SUITE_AES_CMAC:
1024 		return ieee80211_crypto_aes_cmac_encrypt(tx);
1025 	default:
1026 		return ieee80211_crypto_hw_encrypt(tx);
1027 	}
1028 
1029 	return TX_DROP;
1030 }
1031 
1032 static ieee80211_tx_result debug_noinline
1033 ieee80211_tx_h_calculate_duration(struct ieee80211_tx_data *tx)
1034 {
1035 	struct sk_buff *skb;
1036 	struct ieee80211_hdr *hdr;
1037 	int next_len;
1038 	bool group_addr;
1039 
1040 	skb_queue_walk(&tx->skbs, skb) {
1041 		hdr = (void *) skb->data;
1042 		if (unlikely(ieee80211_is_pspoll(hdr->frame_control)))
1043 			break; /* must not overwrite AID */
1044 		if (!skb_queue_is_last(&tx->skbs, skb)) {
1045 			struct sk_buff *next = skb_queue_next(&tx->skbs, skb);
1046 			next_len = next->len;
1047 		} else
1048 			next_len = 0;
1049 		group_addr = is_multicast_ether_addr(hdr->addr1);
1050 
1051 		hdr->duration_id =
1052 			ieee80211_duration(tx, skb, group_addr, next_len);
1053 	}
1054 
1055 	return TX_CONTINUE;
1056 }
1057 
1058 /* actual transmit path */
1059 
1060 static bool ieee80211_tx_prep_agg(struct ieee80211_tx_data *tx,
1061 				  struct sk_buff *skb,
1062 				  struct ieee80211_tx_info *info,
1063 				  struct tid_ampdu_tx *tid_tx,
1064 				  int tid)
1065 {
1066 	bool queued = false;
1067 	bool reset_agg_timer = false;
1068 	struct sk_buff *purge_skb = NULL;
1069 
1070 	if (test_bit(HT_AGG_STATE_OPERATIONAL, &tid_tx->state)) {
1071 		info->flags |= IEEE80211_TX_CTL_AMPDU;
1072 		reset_agg_timer = true;
1073 	} else if (test_bit(HT_AGG_STATE_WANT_START, &tid_tx->state)) {
1074 		/*
1075 		 * nothing -- this aggregation session is being started
1076 		 * but that might still fail with the driver
1077 		 */
1078 	} else {
1079 		spin_lock(&tx->sta->lock);
1080 		/*
1081 		 * Need to re-check now, because we may get here
1082 		 *
1083 		 *  1) in the window during which the setup is actually
1084 		 *     already done, but not marked yet because not all
1085 		 *     packets are spliced over to the driver pending
1086 		 *     queue yet -- if this happened we acquire the lock
1087 		 *     either before or after the splice happens, but
1088 		 *     need to recheck which of these cases happened.
1089 		 *
1090 		 *  2) during session teardown, if the OPERATIONAL bit
1091 		 *     was cleared due to the teardown but the pointer
1092 		 *     hasn't been assigned NULL yet (or we loaded it
1093 		 *     before it was assigned) -- in this case it may
1094 		 *     now be NULL which means we should just let the
1095 		 *     packet pass through because splicing the frames
1096 		 *     back is already done.
1097 		 */
1098 		tid_tx = rcu_dereference_protected_tid_tx(tx->sta, tid);
1099 
1100 		if (!tid_tx) {
1101 			/* do nothing, let packet pass through */
1102 		} else if (test_bit(HT_AGG_STATE_OPERATIONAL, &tid_tx->state)) {
1103 			info->flags |= IEEE80211_TX_CTL_AMPDU;
1104 			reset_agg_timer = true;
1105 		} else {
1106 			queued = true;
1107 			info->control.vif = &tx->sdata->vif;
1108 			info->flags |= IEEE80211_TX_INTFL_NEED_TXPROCESSING;
1109 			__skb_queue_tail(&tid_tx->pending, skb);
1110 			if (skb_queue_len(&tid_tx->pending) > STA_MAX_TX_BUFFER)
1111 				purge_skb = __skb_dequeue(&tid_tx->pending);
1112 		}
1113 		spin_unlock(&tx->sta->lock);
1114 
1115 		if (purge_skb)
1116 			dev_kfree_skb(purge_skb);
1117 	}
1118 
1119 	/* reset session timer */
1120 	if (reset_agg_timer && tid_tx->timeout)
1121 		mod_timer(&tid_tx->session_timer,
1122 			  TU_TO_EXP_TIME(tid_tx->timeout));
1123 
1124 	return queued;
1125 }
1126 
1127 /*
1128  * initialises @tx
1129  */
1130 static ieee80211_tx_result
1131 ieee80211_tx_prepare(struct ieee80211_sub_if_data *sdata,
1132 		     struct ieee80211_tx_data *tx,
1133 		     struct sk_buff *skb)
1134 {
1135 	struct ieee80211_local *local = sdata->local;
1136 	struct ieee80211_hdr *hdr;
1137 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
1138 	int tid;
1139 	u8 *qc;
1140 
1141 	memset(tx, 0, sizeof(*tx));
1142 	tx->skb = skb;
1143 	tx->local = local;
1144 	tx->sdata = sdata;
1145 	tx->channel = local->hw.conf.channel;
1146 	__skb_queue_head_init(&tx->skbs);
1147 
1148 	/*
1149 	 * If this flag is set to true anywhere, and we get here,
1150 	 * we are doing the needed processing, so remove the flag
1151 	 * now.
1152 	 */
1153 	info->flags &= ~IEEE80211_TX_INTFL_NEED_TXPROCESSING;
1154 
1155 	hdr = (struct ieee80211_hdr *) skb->data;
1156 
1157 	if (sdata->vif.type == NL80211_IFTYPE_AP_VLAN) {
1158 		tx->sta = rcu_dereference(sdata->u.vlan.sta);
1159 		if (!tx->sta && sdata->dev->ieee80211_ptr->use_4addr)
1160 			return TX_DROP;
1161 	} else if (info->flags & IEEE80211_TX_CTL_INJECTED ||
1162 		   tx->sdata->control_port_protocol == tx->skb->protocol) {
1163 		tx->sta = sta_info_get_bss(sdata, hdr->addr1);
1164 	}
1165 	if (!tx->sta)
1166 		tx->sta = sta_info_get(sdata, hdr->addr1);
1167 
1168 	if (tx->sta && ieee80211_is_data_qos(hdr->frame_control) &&
1169 	    !ieee80211_is_qos_nullfunc(hdr->frame_control) &&
1170 	    (local->hw.flags & IEEE80211_HW_AMPDU_AGGREGATION) &&
1171 	    !(local->hw.flags & IEEE80211_HW_TX_AMPDU_SETUP_IN_HW)) {
1172 		struct tid_ampdu_tx *tid_tx;
1173 
1174 		qc = ieee80211_get_qos_ctl(hdr);
1175 		tid = *qc & IEEE80211_QOS_CTL_TID_MASK;
1176 
1177 		tid_tx = rcu_dereference(tx->sta->ampdu_mlme.tid_tx[tid]);
1178 		if (tid_tx) {
1179 			bool queued;
1180 
1181 			queued = ieee80211_tx_prep_agg(tx, skb, info,
1182 						       tid_tx, tid);
1183 
1184 			if (unlikely(queued))
1185 				return TX_QUEUED;
1186 		}
1187 	}
1188 
1189 	if (is_multicast_ether_addr(hdr->addr1)) {
1190 		tx->flags &= ~IEEE80211_TX_UNICAST;
1191 		info->flags |= IEEE80211_TX_CTL_NO_ACK;
1192 	} else
1193 		tx->flags |= IEEE80211_TX_UNICAST;
1194 
1195 	if (!(info->flags & IEEE80211_TX_CTL_DONTFRAG)) {
1196 		if (!(tx->flags & IEEE80211_TX_UNICAST) ||
1197 		    skb->len + FCS_LEN <= local->hw.wiphy->frag_threshold ||
1198 		    info->flags & IEEE80211_TX_CTL_AMPDU)
1199 			info->flags |= IEEE80211_TX_CTL_DONTFRAG;
1200 	}
1201 
1202 	if (!tx->sta)
1203 		info->flags |= IEEE80211_TX_CTL_CLEAR_PS_FILT;
1204 	else if (test_and_clear_sta_flag(tx->sta, WLAN_STA_CLEAR_PS_FILT))
1205 		info->flags |= IEEE80211_TX_CTL_CLEAR_PS_FILT;
1206 
1207 	info->flags |= IEEE80211_TX_CTL_FIRST_FRAGMENT;
1208 
1209 	return TX_CONTINUE;
1210 }
1211 
1212 static bool ieee80211_tx_frags(struct ieee80211_local *local,
1213 			       struct ieee80211_vif *vif,
1214 			       struct ieee80211_sta *sta,
1215 			       struct sk_buff_head *skbs,
1216 			       bool txpending)
1217 {
1218 	struct sk_buff *skb, *tmp;
1219 	struct ieee80211_tx_info *info;
1220 	unsigned long flags;
1221 
1222 	skb_queue_walk_safe(skbs, skb, tmp) {
1223 		int q = skb_get_queue_mapping(skb);
1224 
1225 		spin_lock_irqsave(&local->queue_stop_reason_lock, flags);
1226 		if (local->queue_stop_reasons[q] ||
1227 		    (!txpending && !skb_queue_empty(&local->pending[q]))) {
1228 			/*
1229 			 * Since queue is stopped, queue up frames for later
1230 			 * transmission from the tx-pending tasklet when the
1231 			 * queue is woken again.
1232 			 */
1233 			if (txpending)
1234 				skb_queue_splice_init(skbs, &local->pending[q]);
1235 			else
1236 				skb_queue_splice_tail_init(skbs,
1237 							   &local->pending[q]);
1238 
1239 			spin_unlock_irqrestore(&local->queue_stop_reason_lock,
1240 					       flags);
1241 			return false;
1242 		}
1243 		spin_unlock_irqrestore(&local->queue_stop_reason_lock, flags);
1244 
1245 		info = IEEE80211_SKB_CB(skb);
1246 		info->control.vif = vif;
1247 		info->control.sta = sta;
1248 
1249 		__skb_unlink(skb, skbs);
1250 		drv_tx(local, skb);
1251 	}
1252 
1253 	return true;
1254 }
1255 
1256 /*
1257  * Returns false if the frame couldn't be transmitted but was queued instead.
1258  */
1259 static bool __ieee80211_tx(struct ieee80211_local *local,
1260 			   struct sk_buff_head *skbs, int led_len,
1261 			   struct sta_info *sta, bool txpending)
1262 {
1263 	struct ieee80211_tx_info *info;
1264 	struct ieee80211_sub_if_data *sdata;
1265 	struct ieee80211_vif *vif;
1266 	struct ieee80211_sta *pubsta;
1267 	struct sk_buff *skb;
1268 	bool result = true;
1269 	__le16 fc;
1270 
1271 	if (WARN_ON(skb_queue_empty(skbs)))
1272 		return true;
1273 
1274 	skb = skb_peek(skbs);
1275 	fc = ((struct ieee80211_hdr *)skb->data)->frame_control;
1276 	info = IEEE80211_SKB_CB(skb);
1277 	sdata = vif_to_sdata(info->control.vif);
1278 	if (sta && !sta->uploaded)
1279 		sta = NULL;
1280 
1281 	if (sta)
1282 		pubsta = &sta->sta;
1283 	else
1284 		pubsta = NULL;
1285 
1286 	switch (sdata->vif.type) {
1287 	case NL80211_IFTYPE_MONITOR:
1288 		sdata = NULL;
1289 		vif = NULL;
1290 		break;
1291 	case NL80211_IFTYPE_AP_VLAN:
1292 		sdata = container_of(sdata->bss,
1293 				     struct ieee80211_sub_if_data, u.ap);
1294 		/* fall through */
1295 	default:
1296 		vif = &sdata->vif;
1297 		break;
1298 	}
1299 
1300 	if (local->ops->tx_frags)
1301 		drv_tx_frags(local, vif, pubsta, skbs);
1302 	else
1303 		result = ieee80211_tx_frags(local, vif, pubsta, skbs,
1304 					    txpending);
1305 
1306 	ieee80211_tpt_led_trig_tx(local, fc, led_len);
1307 	ieee80211_led_tx(local, 1);
1308 
1309 	WARN_ON_ONCE(!skb_queue_empty(skbs));
1310 
1311 	return result;
1312 }
1313 
1314 /*
1315  * Invoke TX handlers, return 0 on success and non-zero if the
1316  * frame was dropped or queued.
1317  */
1318 static int invoke_tx_handlers(struct ieee80211_tx_data *tx)
1319 {
1320 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(tx->skb);
1321 	ieee80211_tx_result res = TX_DROP;
1322 
1323 #define CALL_TXH(txh) \
1324 	do {				\
1325 		res = txh(tx);		\
1326 		if (res != TX_CONTINUE)	\
1327 			goto txh_done;	\
1328 	} while (0)
1329 
1330 	CALL_TXH(ieee80211_tx_h_dynamic_ps);
1331 	CALL_TXH(ieee80211_tx_h_check_assoc);
1332 	CALL_TXH(ieee80211_tx_h_ps_buf);
1333 	CALL_TXH(ieee80211_tx_h_check_control_port_protocol);
1334 	CALL_TXH(ieee80211_tx_h_select_key);
1335 	if (!(tx->local->hw.flags & IEEE80211_HW_HAS_RATE_CONTROL))
1336 		CALL_TXH(ieee80211_tx_h_rate_ctrl);
1337 
1338 	if (unlikely(info->flags & IEEE80211_TX_INTFL_RETRANSMISSION)) {
1339 		__skb_queue_tail(&tx->skbs, tx->skb);
1340 		tx->skb = NULL;
1341 		goto txh_done;
1342 	}
1343 
1344 	CALL_TXH(ieee80211_tx_h_michael_mic_add);
1345 	CALL_TXH(ieee80211_tx_h_sequence);
1346 	CALL_TXH(ieee80211_tx_h_fragment);
1347 	/* handlers after fragment must be aware of tx info fragmentation! */
1348 	CALL_TXH(ieee80211_tx_h_stats);
1349 	CALL_TXH(ieee80211_tx_h_encrypt);
1350 	if (!(tx->local->hw.flags & IEEE80211_HW_HAS_RATE_CONTROL))
1351 		CALL_TXH(ieee80211_tx_h_calculate_duration);
1352 #undef CALL_TXH
1353 
1354  txh_done:
1355 	if (unlikely(res == TX_DROP)) {
1356 		I802_DEBUG_INC(tx->local->tx_handlers_drop);
1357 		if (tx->skb)
1358 			dev_kfree_skb(tx->skb);
1359 		else
1360 			__skb_queue_purge(&tx->skbs);
1361 		return -1;
1362 	} else if (unlikely(res == TX_QUEUED)) {
1363 		I802_DEBUG_INC(tx->local->tx_handlers_queued);
1364 		return -1;
1365 	}
1366 
1367 	return 0;
1368 }
1369 
1370 /*
1371  * Returns false if the frame couldn't be transmitted but was queued instead.
1372  */
1373 static bool ieee80211_tx(struct ieee80211_sub_if_data *sdata,
1374 			 struct sk_buff *skb, bool txpending)
1375 {
1376 	struct ieee80211_local *local = sdata->local;
1377 	struct ieee80211_tx_data tx;
1378 	ieee80211_tx_result res_prepare;
1379 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
1380 	bool result = true;
1381 	int led_len;
1382 
1383 	if (unlikely(skb->len < 10)) {
1384 		dev_kfree_skb(skb);
1385 		return true;
1386 	}
1387 
1388 	rcu_read_lock();
1389 
1390 	/* initialises tx */
1391 	led_len = skb->len;
1392 	res_prepare = ieee80211_tx_prepare(sdata, &tx, skb);
1393 
1394 	if (unlikely(res_prepare == TX_DROP)) {
1395 		dev_kfree_skb(skb);
1396 		goto out;
1397 	} else if (unlikely(res_prepare == TX_QUEUED)) {
1398 		goto out;
1399 	}
1400 
1401 	tx.channel = local->hw.conf.channel;
1402 	info->band = tx.channel->band;
1403 
1404 	if (!invoke_tx_handlers(&tx))
1405 		result = __ieee80211_tx(local, &tx.skbs, led_len,
1406 					tx.sta, txpending);
1407  out:
1408 	rcu_read_unlock();
1409 	return result;
1410 }
1411 
1412 /* device xmit handlers */
1413 
1414 static int ieee80211_skb_resize(struct ieee80211_sub_if_data *sdata,
1415 				struct sk_buff *skb,
1416 				int head_need, bool may_encrypt)
1417 {
1418 	struct ieee80211_local *local = sdata->local;
1419 	int tail_need = 0;
1420 
1421 	if (may_encrypt && sdata->crypto_tx_tailroom_needed_cnt) {
1422 		tail_need = IEEE80211_ENCRYPT_TAILROOM;
1423 		tail_need -= skb_tailroom(skb);
1424 		tail_need = max_t(int, tail_need, 0);
1425 	}
1426 
1427 	if (skb_cloned(skb))
1428 		I802_DEBUG_INC(local->tx_expand_skb_head_cloned);
1429 	else if (head_need || tail_need)
1430 		I802_DEBUG_INC(local->tx_expand_skb_head);
1431 	else
1432 		return 0;
1433 
1434 	if (pskb_expand_head(skb, head_need, tail_need, GFP_ATOMIC)) {
1435 		wiphy_debug(local->hw.wiphy,
1436 			    "failed to reallocate TX buffer\n");
1437 		return -ENOMEM;
1438 	}
1439 
1440 	return 0;
1441 }
1442 
1443 void ieee80211_xmit(struct ieee80211_sub_if_data *sdata, struct sk_buff *skb)
1444 {
1445 	struct ieee80211_local *local = sdata->local;
1446 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
1447 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
1448 	int headroom;
1449 	bool may_encrypt;
1450 
1451 	rcu_read_lock();
1452 
1453 	may_encrypt = !(info->flags & IEEE80211_TX_INTFL_DONT_ENCRYPT);
1454 
1455 	headroom = local->tx_headroom;
1456 	if (may_encrypt)
1457 		headroom += IEEE80211_ENCRYPT_HEADROOM;
1458 	headroom -= skb_headroom(skb);
1459 	headroom = max_t(int, 0, headroom);
1460 
1461 	if (ieee80211_skb_resize(sdata, skb, headroom, may_encrypt)) {
1462 		dev_kfree_skb(skb);
1463 		rcu_read_unlock();
1464 		return;
1465 	}
1466 
1467 	hdr = (struct ieee80211_hdr *) skb->data;
1468 	info->control.vif = &sdata->vif;
1469 
1470 	if (ieee80211_vif_is_mesh(&sdata->vif) &&
1471 	    ieee80211_is_data(hdr->frame_control) &&
1472 		!is_multicast_ether_addr(hdr->addr1))
1473 			if (mesh_nexthop_resolve(skb, sdata)) {
1474 				/* skb queued: don't free */
1475 				rcu_read_unlock();
1476 				return;
1477 			}
1478 
1479 	ieee80211_set_qos_hdr(sdata, skb);
1480 	ieee80211_tx(sdata, skb, false);
1481 	rcu_read_unlock();
1482 }
1483 
1484 static bool ieee80211_parse_tx_radiotap(struct sk_buff *skb)
1485 {
1486 	struct ieee80211_radiotap_iterator iterator;
1487 	struct ieee80211_radiotap_header *rthdr =
1488 		(struct ieee80211_radiotap_header *) skb->data;
1489 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
1490 	int ret = ieee80211_radiotap_iterator_init(&iterator, rthdr, skb->len,
1491 						   NULL);
1492 	u16 txflags;
1493 
1494 	info->flags |= IEEE80211_TX_INTFL_DONT_ENCRYPT |
1495 		       IEEE80211_TX_CTL_DONTFRAG;
1496 
1497 	/*
1498 	 * for every radiotap entry that is present
1499 	 * (ieee80211_radiotap_iterator_next returns -ENOENT when no more
1500 	 * entries present, or -EINVAL on error)
1501 	 */
1502 
1503 	while (!ret) {
1504 		ret = ieee80211_radiotap_iterator_next(&iterator);
1505 
1506 		if (ret)
1507 			continue;
1508 
1509 		/* see if this argument is something we can use */
1510 		switch (iterator.this_arg_index) {
1511 		/*
1512 		 * You must take care when dereferencing iterator.this_arg
1513 		 * for multibyte types... the pointer is not aligned.  Use
1514 		 * get_unaligned((type *)iterator.this_arg) to dereference
1515 		 * iterator.this_arg for type "type" safely on all arches.
1516 		*/
1517 		case IEEE80211_RADIOTAP_FLAGS:
1518 			if (*iterator.this_arg & IEEE80211_RADIOTAP_F_FCS) {
1519 				/*
1520 				 * this indicates that the skb we have been
1521 				 * handed has the 32-bit FCS CRC at the end...
1522 				 * we should react to that by snipping it off
1523 				 * because it will be recomputed and added
1524 				 * on transmission
1525 				 */
1526 				if (skb->len < (iterator._max_length + FCS_LEN))
1527 					return false;
1528 
1529 				skb_trim(skb, skb->len - FCS_LEN);
1530 			}
1531 			if (*iterator.this_arg & IEEE80211_RADIOTAP_F_WEP)
1532 				info->flags &= ~IEEE80211_TX_INTFL_DONT_ENCRYPT;
1533 			if (*iterator.this_arg & IEEE80211_RADIOTAP_F_FRAG)
1534 				info->flags &= ~IEEE80211_TX_CTL_DONTFRAG;
1535 			break;
1536 
1537 		case IEEE80211_RADIOTAP_TX_FLAGS:
1538 			txflags = get_unaligned_le16(iterator.this_arg);
1539 			if (txflags & IEEE80211_RADIOTAP_F_TX_NOACK)
1540 				info->flags |= IEEE80211_TX_CTL_NO_ACK;
1541 			break;
1542 
1543 		/*
1544 		 * Please update the file
1545 		 * Documentation/networking/mac80211-injection.txt
1546 		 * when parsing new fields here.
1547 		 */
1548 
1549 		default:
1550 			break;
1551 		}
1552 	}
1553 
1554 	if (ret != -ENOENT) /* ie, if we didn't simply run out of fields */
1555 		return false;
1556 
1557 	/*
1558 	 * remove the radiotap header
1559 	 * iterator->_max_length was sanity-checked against
1560 	 * skb->len by iterator init
1561 	 */
1562 	skb_pull(skb, iterator._max_length);
1563 
1564 	return true;
1565 }
1566 
1567 netdev_tx_t ieee80211_monitor_start_xmit(struct sk_buff *skb,
1568 					 struct net_device *dev)
1569 {
1570 	struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
1571 	struct ieee80211_channel *chan = local->hw.conf.channel;
1572 	struct ieee80211_radiotap_header *prthdr =
1573 		(struct ieee80211_radiotap_header *)skb->data;
1574 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
1575 	struct ieee80211_hdr *hdr;
1576 	struct ieee80211_sub_if_data *tmp_sdata, *sdata;
1577 	u16 len_rthdr;
1578 	int hdrlen;
1579 
1580 	/*
1581 	 * Frame injection is not allowed if beaconing is not allowed
1582 	 * or if we need radar detection. Beaconing is usually not allowed when
1583 	 * the mode or operation (Adhoc, AP, Mesh) does not support DFS.
1584 	 * Passive scan is also used in world regulatory domains where
1585 	 * your country is not known and as such it should be treated as
1586 	 * NO TX unless the channel is explicitly allowed in which case
1587 	 * your current regulatory domain would not have the passive scan
1588 	 * flag.
1589 	 *
1590 	 * Since AP mode uses monitor interfaces to inject/TX management
1591 	 * frames we can make AP mode the exception to this rule once it
1592 	 * supports radar detection as its implementation can deal with
1593 	 * radar detection by itself. We can do that later by adding a
1594 	 * monitor flag interfaces used for AP support.
1595 	 */
1596 	if ((chan->flags & (IEEE80211_CHAN_NO_IBSS | IEEE80211_CHAN_RADAR |
1597 	     IEEE80211_CHAN_PASSIVE_SCAN)))
1598 		goto fail;
1599 
1600 	/* check for not even having the fixed radiotap header part */
1601 	if (unlikely(skb->len < sizeof(struct ieee80211_radiotap_header)))
1602 		goto fail; /* too short to be possibly valid */
1603 
1604 	/* is it a header version we can trust to find length from? */
1605 	if (unlikely(prthdr->it_version))
1606 		goto fail; /* only version 0 is supported */
1607 
1608 	/* then there must be a radiotap header with a length we can use */
1609 	len_rthdr = ieee80211_get_radiotap_len(skb->data);
1610 
1611 	/* does the skb contain enough to deliver on the alleged length? */
1612 	if (unlikely(skb->len < len_rthdr))
1613 		goto fail; /* skb too short for claimed rt header extent */
1614 
1615 	/*
1616 	 * fix up the pointers accounting for the radiotap
1617 	 * header still being in there.  We are being given
1618 	 * a precooked IEEE80211 header so no need for
1619 	 * normal processing
1620 	 */
1621 	skb_set_mac_header(skb, len_rthdr);
1622 	/*
1623 	 * these are just fixed to the end of the rt area since we
1624 	 * don't have any better information and at this point, nobody cares
1625 	 */
1626 	skb_set_network_header(skb, len_rthdr);
1627 	skb_set_transport_header(skb, len_rthdr);
1628 
1629 	if (skb->len < len_rthdr + 2)
1630 		goto fail;
1631 
1632 	hdr = (struct ieee80211_hdr *)(skb->data + len_rthdr);
1633 	hdrlen = ieee80211_hdrlen(hdr->frame_control);
1634 
1635 	if (skb->len < len_rthdr + hdrlen)
1636 		goto fail;
1637 
1638 	/*
1639 	 * Initialize skb->protocol if the injected frame is a data frame
1640 	 * carrying a rfc1042 header
1641 	 */
1642 	if (ieee80211_is_data(hdr->frame_control) &&
1643 	    skb->len >= len_rthdr + hdrlen + sizeof(rfc1042_header) + 2) {
1644 		u8 *payload = (u8 *)hdr + hdrlen;
1645 
1646 		if (compare_ether_addr(payload, rfc1042_header) == 0)
1647 			skb->protocol = cpu_to_be16((payload[6] << 8) |
1648 						    payload[7]);
1649 	}
1650 
1651 	memset(info, 0, sizeof(*info));
1652 
1653 	info->flags = IEEE80211_TX_CTL_REQ_TX_STATUS |
1654 		      IEEE80211_TX_CTL_INJECTED;
1655 
1656 	/* process and remove the injection radiotap header */
1657 	if (!ieee80211_parse_tx_radiotap(skb))
1658 		goto fail;
1659 
1660 	rcu_read_lock();
1661 
1662 	/*
1663 	 * We process outgoing injected frames that have a local address
1664 	 * we handle as though they are non-injected frames.
1665 	 * This code here isn't entirely correct, the local MAC address
1666 	 * isn't always enough to find the interface to use; for proper
1667 	 * VLAN/WDS support we will need a different mechanism (which
1668 	 * likely isn't going to be monitor interfaces).
1669 	 */
1670 	sdata = IEEE80211_DEV_TO_SUB_IF(dev);
1671 
1672 	list_for_each_entry_rcu(tmp_sdata, &local->interfaces, list) {
1673 		if (!ieee80211_sdata_running(tmp_sdata))
1674 			continue;
1675 		if (tmp_sdata->vif.type == NL80211_IFTYPE_MONITOR ||
1676 		    tmp_sdata->vif.type == NL80211_IFTYPE_AP_VLAN ||
1677 		    tmp_sdata->vif.type == NL80211_IFTYPE_WDS)
1678 			continue;
1679 		if (compare_ether_addr(tmp_sdata->vif.addr, hdr->addr2) == 0) {
1680 			sdata = tmp_sdata;
1681 			break;
1682 		}
1683 	}
1684 
1685 	ieee80211_xmit(sdata, skb);
1686 	rcu_read_unlock();
1687 
1688 	return NETDEV_TX_OK;
1689 
1690 fail:
1691 	dev_kfree_skb(skb);
1692 	return NETDEV_TX_OK; /* meaning, we dealt with the skb */
1693 }
1694 
1695 /**
1696  * ieee80211_subif_start_xmit - netif start_xmit function for Ethernet-type
1697  * subinterfaces (wlan#, WDS, and VLAN interfaces)
1698  * @skb: packet to be sent
1699  * @dev: incoming interface
1700  *
1701  * Returns: 0 on success (and frees skb in this case) or 1 on failure (skb will
1702  * not be freed, and caller is responsible for either retrying later or freeing
1703  * skb).
1704  *
1705  * This function takes in an Ethernet header and encapsulates it with suitable
1706  * IEEE 802.11 header based on which interface the packet is coming in. The
1707  * encapsulated packet will then be passed to master interface, wlan#.11, for
1708  * transmission (through low-level driver).
1709  */
1710 netdev_tx_t ieee80211_subif_start_xmit(struct sk_buff *skb,
1711 				    struct net_device *dev)
1712 {
1713 	struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
1714 	struct ieee80211_local *local = sdata->local;
1715 	struct ieee80211_tx_info *info;
1716 	int ret = NETDEV_TX_BUSY, head_need;
1717 	u16 ethertype, hdrlen,  meshhdrlen = 0;
1718 	__le16 fc;
1719 	struct ieee80211_hdr hdr;
1720 	struct ieee80211s_hdr mesh_hdr __maybe_unused;
1721 	struct mesh_path __maybe_unused *mppath = NULL;
1722 	const u8 *encaps_data;
1723 	int encaps_len, skip_header_bytes;
1724 	int nh_pos, h_pos;
1725 	struct sta_info *sta = NULL;
1726 	bool wme_sta = false, authorized = false, tdls_auth = false;
1727 	bool tdls_direct = false;
1728 	bool multicast;
1729 	u32 info_flags = 0;
1730 	u16 info_id = 0;
1731 
1732 	if (unlikely(skb->len < ETH_HLEN)) {
1733 		ret = NETDEV_TX_OK;
1734 		goto fail;
1735 	}
1736 
1737 	/* convert Ethernet header to proper 802.11 header (based on
1738 	 * operation mode) */
1739 	ethertype = (skb->data[12] << 8) | skb->data[13];
1740 	fc = cpu_to_le16(IEEE80211_FTYPE_DATA | IEEE80211_STYPE_DATA);
1741 
1742 	switch (sdata->vif.type) {
1743 	case NL80211_IFTYPE_AP_VLAN:
1744 		rcu_read_lock();
1745 		sta = rcu_dereference(sdata->u.vlan.sta);
1746 		if (sta) {
1747 			fc |= cpu_to_le16(IEEE80211_FCTL_FROMDS | IEEE80211_FCTL_TODS);
1748 			/* RA TA DA SA */
1749 			memcpy(hdr.addr1, sta->sta.addr, ETH_ALEN);
1750 			memcpy(hdr.addr2, sdata->vif.addr, ETH_ALEN);
1751 			memcpy(hdr.addr3, skb->data, ETH_ALEN);
1752 			memcpy(hdr.addr4, skb->data + ETH_ALEN, ETH_ALEN);
1753 			hdrlen = 30;
1754 			authorized = test_sta_flag(sta, WLAN_STA_AUTHORIZED);
1755 			wme_sta = test_sta_flag(sta, WLAN_STA_WME);
1756 		}
1757 		rcu_read_unlock();
1758 		if (sta)
1759 			break;
1760 		/* fall through */
1761 	case NL80211_IFTYPE_AP:
1762 		fc |= cpu_to_le16(IEEE80211_FCTL_FROMDS);
1763 		/* DA BSSID SA */
1764 		memcpy(hdr.addr1, skb->data, ETH_ALEN);
1765 		memcpy(hdr.addr2, sdata->vif.addr, ETH_ALEN);
1766 		memcpy(hdr.addr3, skb->data + ETH_ALEN, ETH_ALEN);
1767 		hdrlen = 24;
1768 		break;
1769 	case NL80211_IFTYPE_WDS:
1770 		fc |= cpu_to_le16(IEEE80211_FCTL_FROMDS | IEEE80211_FCTL_TODS);
1771 		/* RA TA DA SA */
1772 		memcpy(hdr.addr1, sdata->u.wds.remote_addr, ETH_ALEN);
1773 		memcpy(hdr.addr2, sdata->vif.addr, ETH_ALEN);
1774 		memcpy(hdr.addr3, skb->data, ETH_ALEN);
1775 		memcpy(hdr.addr4, skb->data + ETH_ALEN, ETH_ALEN);
1776 		hdrlen = 30;
1777 		break;
1778 #ifdef CONFIG_MAC80211_MESH
1779 	case NL80211_IFTYPE_MESH_POINT:
1780 		if (!sdata->u.mesh.mshcfg.dot11MeshTTL) {
1781 			/* Do not send frames with mesh_ttl == 0 */
1782 			sdata->u.mesh.mshstats.dropped_frames_ttl++;
1783 			ret = NETDEV_TX_OK;
1784 			goto fail;
1785 		}
1786 		rcu_read_lock();
1787 		if (!is_multicast_ether_addr(skb->data))
1788 			mppath = mpp_path_lookup(skb->data, sdata);
1789 
1790 		/*
1791 		 * Use address extension if it is a packet from
1792 		 * another interface or if we know the destination
1793 		 * is being proxied by a portal (i.e. portal address
1794 		 * differs from proxied address)
1795 		 */
1796 		if (compare_ether_addr(sdata->vif.addr,
1797 				       skb->data + ETH_ALEN) == 0 &&
1798 		    !(mppath && compare_ether_addr(mppath->mpp, skb->data))) {
1799 			hdrlen = ieee80211_fill_mesh_addresses(&hdr, &fc,
1800 					skb->data, skb->data + ETH_ALEN);
1801 			rcu_read_unlock();
1802 			meshhdrlen = ieee80211_new_mesh_header(&mesh_hdr,
1803 					sdata, NULL, NULL);
1804 		} else {
1805 			int is_mesh_mcast = 1;
1806 			const u8 *mesh_da;
1807 
1808 			if (is_multicast_ether_addr(skb->data))
1809 				/* DA TA mSA AE:SA */
1810 				mesh_da = skb->data;
1811 			else {
1812 				static const u8 bcast[ETH_ALEN] =
1813 					{ 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };
1814 				if (mppath) {
1815 					/* RA TA mDA mSA AE:DA SA */
1816 					mesh_da = mppath->mpp;
1817 					is_mesh_mcast = 0;
1818 				} else {
1819 					/* DA TA mSA AE:SA */
1820 					mesh_da = bcast;
1821 				}
1822 			}
1823 			hdrlen = ieee80211_fill_mesh_addresses(&hdr, &fc,
1824 					mesh_da, sdata->vif.addr);
1825 			rcu_read_unlock();
1826 			if (is_mesh_mcast)
1827 				meshhdrlen =
1828 					ieee80211_new_mesh_header(&mesh_hdr,
1829 							sdata,
1830 							skb->data + ETH_ALEN,
1831 							NULL);
1832 			else
1833 				meshhdrlen =
1834 					ieee80211_new_mesh_header(&mesh_hdr,
1835 							sdata,
1836 							skb->data,
1837 							skb->data + ETH_ALEN);
1838 
1839 		}
1840 		break;
1841 #endif
1842 	case NL80211_IFTYPE_STATION:
1843 		if (sdata->wdev.wiphy->flags & WIPHY_FLAG_SUPPORTS_TDLS) {
1844 			bool tdls_peer = false;
1845 
1846 			rcu_read_lock();
1847 			sta = sta_info_get(sdata, skb->data);
1848 			if (sta) {
1849 				authorized = test_sta_flag(sta,
1850 							WLAN_STA_AUTHORIZED);
1851 				wme_sta = test_sta_flag(sta, WLAN_STA_WME);
1852 				tdls_peer = test_sta_flag(sta,
1853 							 WLAN_STA_TDLS_PEER);
1854 				tdls_auth = test_sta_flag(sta,
1855 						WLAN_STA_TDLS_PEER_AUTH);
1856 			}
1857 			rcu_read_unlock();
1858 
1859 			/*
1860 			 * If the TDLS link is enabled, send everything
1861 			 * directly. Otherwise, allow TDLS setup frames
1862 			 * to be transmitted indirectly.
1863 			 */
1864 			tdls_direct = tdls_peer && (tdls_auth ||
1865 				 !(ethertype == ETH_P_TDLS && skb->len > 14 &&
1866 				   skb->data[14] == WLAN_TDLS_SNAP_RFTYPE));
1867 		}
1868 
1869 		if (tdls_direct) {
1870 			/* link during setup - throw out frames to peer */
1871 			if (!tdls_auth) {
1872 				ret = NETDEV_TX_OK;
1873 				goto fail;
1874 			}
1875 
1876 			/* DA SA BSSID */
1877 			memcpy(hdr.addr1, skb->data, ETH_ALEN);
1878 			memcpy(hdr.addr2, skb->data + ETH_ALEN, ETH_ALEN);
1879 			memcpy(hdr.addr3, sdata->u.mgd.bssid, ETH_ALEN);
1880 			hdrlen = 24;
1881 		}  else if (sdata->u.mgd.use_4addr &&
1882 			    cpu_to_be16(ethertype) != sdata->control_port_protocol) {
1883 			fc |= cpu_to_le16(IEEE80211_FCTL_FROMDS |
1884 					  IEEE80211_FCTL_TODS);
1885 			/* RA TA DA SA */
1886 			memcpy(hdr.addr1, sdata->u.mgd.bssid, ETH_ALEN);
1887 			memcpy(hdr.addr2, sdata->vif.addr, ETH_ALEN);
1888 			memcpy(hdr.addr3, skb->data, ETH_ALEN);
1889 			memcpy(hdr.addr4, skb->data + ETH_ALEN, ETH_ALEN);
1890 			hdrlen = 30;
1891 		} else {
1892 			fc |= cpu_to_le16(IEEE80211_FCTL_TODS);
1893 			/* BSSID SA DA */
1894 			memcpy(hdr.addr1, sdata->u.mgd.bssid, ETH_ALEN);
1895 			memcpy(hdr.addr2, skb->data + ETH_ALEN, ETH_ALEN);
1896 			memcpy(hdr.addr3, skb->data, ETH_ALEN);
1897 			hdrlen = 24;
1898 		}
1899 		break;
1900 	case NL80211_IFTYPE_ADHOC:
1901 		/* DA SA BSSID */
1902 		memcpy(hdr.addr1, skb->data, ETH_ALEN);
1903 		memcpy(hdr.addr2, skb->data + ETH_ALEN, ETH_ALEN);
1904 		memcpy(hdr.addr3, sdata->u.ibss.bssid, ETH_ALEN);
1905 		hdrlen = 24;
1906 		break;
1907 	default:
1908 		ret = NETDEV_TX_OK;
1909 		goto fail;
1910 	}
1911 
1912 	/*
1913 	 * There's no need to try to look up the destination
1914 	 * if it is a multicast address (which can only happen
1915 	 * in AP mode)
1916 	 */
1917 	multicast = is_multicast_ether_addr(hdr.addr1);
1918 	if (!multicast) {
1919 		rcu_read_lock();
1920 		sta = sta_info_get(sdata, hdr.addr1);
1921 		if (sta) {
1922 			authorized = test_sta_flag(sta, WLAN_STA_AUTHORIZED);
1923 			wme_sta = test_sta_flag(sta, WLAN_STA_WME);
1924 		}
1925 		rcu_read_unlock();
1926 	}
1927 
1928 	/* For mesh, the use of the QoS header is mandatory */
1929 	if (ieee80211_vif_is_mesh(&sdata->vif))
1930 		wme_sta = true;
1931 
1932 	/* receiver and we are QoS enabled, use a QoS type frame */
1933 	if (wme_sta && local->hw.queues >= 4) {
1934 		fc |= cpu_to_le16(IEEE80211_STYPE_QOS_DATA);
1935 		hdrlen += 2;
1936 	}
1937 
1938 	/*
1939 	 * Drop unicast frames to unauthorised stations unless they are
1940 	 * EAPOL frames from the local station.
1941 	 */
1942 	if (unlikely(!ieee80211_vif_is_mesh(&sdata->vif) &&
1943 		     !is_multicast_ether_addr(hdr.addr1) && !authorized &&
1944 		     (cpu_to_be16(ethertype) != sdata->control_port_protocol ||
1945 		      compare_ether_addr(sdata->vif.addr, skb->data + ETH_ALEN)))) {
1946 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG
1947 		if (net_ratelimit())
1948 			printk(KERN_DEBUG "%s: dropped frame to %pM"
1949 			       " (unauthorized port)\n", dev->name,
1950 			       hdr.addr1);
1951 #endif
1952 
1953 		I802_DEBUG_INC(local->tx_handlers_drop_unauth_port);
1954 
1955 		ret = NETDEV_TX_OK;
1956 		goto fail;
1957 	}
1958 
1959 	if (unlikely(!multicast && skb->sk &&
1960 		     skb_shinfo(skb)->tx_flags & SKBTX_WIFI_STATUS)) {
1961 		struct sk_buff *orig_skb = skb;
1962 
1963 		skb = skb_clone(skb, GFP_ATOMIC);
1964 		if (skb) {
1965 			unsigned long flags;
1966 			int id, r;
1967 
1968 			spin_lock_irqsave(&local->ack_status_lock, flags);
1969 			r = idr_get_new_above(&local->ack_status_frames,
1970 					      orig_skb, 1, &id);
1971 			if (r == -EAGAIN) {
1972 				idr_pre_get(&local->ack_status_frames,
1973 					    GFP_ATOMIC);
1974 				r = idr_get_new_above(&local->ack_status_frames,
1975 						      orig_skb, 1, &id);
1976 			}
1977 			if (WARN_ON(!id) || id > 0xffff) {
1978 				idr_remove(&local->ack_status_frames, id);
1979 				r = -ERANGE;
1980 			}
1981 			spin_unlock_irqrestore(&local->ack_status_lock, flags);
1982 
1983 			if (!r) {
1984 				info_id = id;
1985 				info_flags |= IEEE80211_TX_CTL_REQ_TX_STATUS;
1986 			} else if (skb_shared(skb)) {
1987 				kfree_skb(orig_skb);
1988 			} else {
1989 				kfree_skb(skb);
1990 				skb = orig_skb;
1991 			}
1992 		} else {
1993 			/* couldn't clone -- lose tx status ... */
1994 			skb = orig_skb;
1995 		}
1996 	}
1997 
1998 	/*
1999 	 * If the skb is shared we need to obtain our own copy.
2000 	 */
2001 	if (skb_shared(skb)) {
2002 		struct sk_buff *tmp_skb = skb;
2003 
2004 		/* can't happen -- skb is a clone if info_id != 0 */
2005 		WARN_ON(info_id);
2006 
2007 		skb = skb_clone(skb, GFP_ATOMIC);
2008 		kfree_skb(tmp_skb);
2009 
2010 		if (!skb) {
2011 			ret = NETDEV_TX_OK;
2012 			goto fail;
2013 		}
2014 	}
2015 
2016 	hdr.frame_control = fc;
2017 	hdr.duration_id = 0;
2018 	hdr.seq_ctrl = 0;
2019 
2020 	skip_header_bytes = ETH_HLEN;
2021 	if (ethertype == ETH_P_AARP || ethertype == ETH_P_IPX) {
2022 		encaps_data = bridge_tunnel_header;
2023 		encaps_len = sizeof(bridge_tunnel_header);
2024 		skip_header_bytes -= 2;
2025 	} else if (ethertype >= 0x600) {
2026 		encaps_data = rfc1042_header;
2027 		encaps_len = sizeof(rfc1042_header);
2028 		skip_header_bytes -= 2;
2029 	} else {
2030 		encaps_data = NULL;
2031 		encaps_len = 0;
2032 	}
2033 
2034 	nh_pos = skb_network_header(skb) - skb->data;
2035 	h_pos = skb_transport_header(skb) - skb->data;
2036 
2037 	skb_pull(skb, skip_header_bytes);
2038 	nh_pos -= skip_header_bytes;
2039 	h_pos -= skip_header_bytes;
2040 
2041 	head_need = hdrlen + encaps_len + meshhdrlen - skb_headroom(skb);
2042 
2043 	/*
2044 	 * So we need to modify the skb header and hence need a copy of
2045 	 * that. The head_need variable above doesn't, so far, include
2046 	 * the needed header space that we don't need right away. If we
2047 	 * can, then we don't reallocate right now but only after the
2048 	 * frame arrives at the master device (if it does...)
2049 	 *
2050 	 * If we cannot, however, then we will reallocate to include all
2051 	 * the ever needed space. Also, if we need to reallocate it anyway,
2052 	 * make it big enough for everything we may ever need.
2053 	 */
2054 
2055 	if (head_need > 0 || skb_cloned(skb)) {
2056 		head_need += IEEE80211_ENCRYPT_HEADROOM;
2057 		head_need += local->tx_headroom;
2058 		head_need = max_t(int, 0, head_need);
2059 		if (ieee80211_skb_resize(sdata, skb, head_need, true))
2060 			goto fail;
2061 	}
2062 
2063 	if (encaps_data) {
2064 		memcpy(skb_push(skb, encaps_len), encaps_data, encaps_len);
2065 		nh_pos += encaps_len;
2066 		h_pos += encaps_len;
2067 	}
2068 
2069 #ifdef CONFIG_MAC80211_MESH
2070 	if (meshhdrlen > 0) {
2071 		memcpy(skb_push(skb, meshhdrlen), &mesh_hdr, meshhdrlen);
2072 		nh_pos += meshhdrlen;
2073 		h_pos += meshhdrlen;
2074 	}
2075 #endif
2076 
2077 	if (ieee80211_is_data_qos(fc)) {
2078 		__le16 *qos_control;
2079 
2080 		qos_control = (__le16*) skb_push(skb, 2);
2081 		memcpy(skb_push(skb, hdrlen - 2), &hdr, hdrlen - 2);
2082 		/*
2083 		 * Maybe we could actually set some fields here, for now just
2084 		 * initialise to zero to indicate no special operation.
2085 		 */
2086 		*qos_control = 0;
2087 	} else
2088 		memcpy(skb_push(skb, hdrlen), &hdr, hdrlen);
2089 
2090 	nh_pos += hdrlen;
2091 	h_pos += hdrlen;
2092 
2093 	dev->stats.tx_packets++;
2094 	dev->stats.tx_bytes += skb->len;
2095 
2096 	/* Update skb pointers to various headers since this modified frame
2097 	 * is going to go through Linux networking code that may potentially
2098 	 * need things like pointer to IP header. */
2099 	skb_set_mac_header(skb, 0);
2100 	skb_set_network_header(skb, nh_pos);
2101 	skb_set_transport_header(skb, h_pos);
2102 
2103 	info = IEEE80211_SKB_CB(skb);
2104 	memset(info, 0, sizeof(*info));
2105 
2106 	dev->trans_start = jiffies;
2107 
2108 	info->flags = info_flags;
2109 	info->ack_frame_id = info_id;
2110 
2111 	ieee80211_xmit(sdata, skb);
2112 
2113 	return NETDEV_TX_OK;
2114 
2115  fail:
2116 	if (ret == NETDEV_TX_OK)
2117 		dev_kfree_skb(skb);
2118 
2119 	return ret;
2120 }
2121 
2122 
2123 /*
2124  * ieee80211_clear_tx_pending may not be called in a context where
2125  * it is possible that it packets could come in again.
2126  */
2127 void ieee80211_clear_tx_pending(struct ieee80211_local *local)
2128 {
2129 	int i;
2130 
2131 	for (i = 0; i < local->hw.queues; i++)
2132 		skb_queue_purge(&local->pending[i]);
2133 }
2134 
2135 /*
2136  * Returns false if the frame couldn't be transmitted but was queued instead,
2137  * which in this case means re-queued -- take as an indication to stop sending
2138  * more pending frames.
2139  */
2140 static bool ieee80211_tx_pending_skb(struct ieee80211_local *local,
2141 				     struct sk_buff *skb)
2142 {
2143 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
2144 	struct ieee80211_sub_if_data *sdata;
2145 	struct sta_info *sta;
2146 	struct ieee80211_hdr *hdr;
2147 	bool result;
2148 
2149 	sdata = vif_to_sdata(info->control.vif);
2150 
2151 	if (info->flags & IEEE80211_TX_INTFL_NEED_TXPROCESSING) {
2152 		result = ieee80211_tx(sdata, skb, true);
2153 	} else {
2154 		struct sk_buff_head skbs;
2155 
2156 		__skb_queue_head_init(&skbs);
2157 		__skb_queue_tail(&skbs, skb);
2158 
2159 		hdr = (struct ieee80211_hdr *)skb->data;
2160 		sta = sta_info_get(sdata, hdr->addr1);
2161 
2162 		result = __ieee80211_tx(local, &skbs, skb->len, sta, true);
2163 	}
2164 
2165 	return result;
2166 }
2167 
2168 /*
2169  * Transmit all pending packets. Called from tasklet.
2170  */
2171 void ieee80211_tx_pending(unsigned long data)
2172 {
2173 	struct ieee80211_local *local = (struct ieee80211_local *)data;
2174 	struct ieee80211_sub_if_data *sdata;
2175 	unsigned long flags;
2176 	int i;
2177 	bool txok;
2178 
2179 	rcu_read_lock();
2180 
2181 	spin_lock_irqsave(&local->queue_stop_reason_lock, flags);
2182 	for (i = 0; i < local->hw.queues; i++) {
2183 		/*
2184 		 * If queue is stopped by something other than due to pending
2185 		 * frames, or we have no pending frames, proceed to next queue.
2186 		 */
2187 		if (local->queue_stop_reasons[i] ||
2188 		    skb_queue_empty(&local->pending[i]))
2189 			continue;
2190 
2191 		while (!skb_queue_empty(&local->pending[i])) {
2192 			struct sk_buff *skb = __skb_dequeue(&local->pending[i]);
2193 			struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
2194 
2195 			if (WARN_ON(!info->control.vif)) {
2196 				kfree_skb(skb);
2197 				continue;
2198 			}
2199 
2200 			spin_unlock_irqrestore(&local->queue_stop_reason_lock,
2201 						flags);
2202 
2203 			txok = ieee80211_tx_pending_skb(local, skb);
2204 			spin_lock_irqsave(&local->queue_stop_reason_lock,
2205 					  flags);
2206 			if (!txok)
2207 				break;
2208 		}
2209 
2210 		if (skb_queue_empty(&local->pending[i]))
2211 			list_for_each_entry_rcu(sdata, &local->interfaces, list)
2212 				netif_wake_subqueue(sdata->dev, i);
2213 	}
2214 	spin_unlock_irqrestore(&local->queue_stop_reason_lock, flags);
2215 
2216 	rcu_read_unlock();
2217 }
2218 
2219 /* functions for drivers to get certain frames */
2220 
2221 static void ieee80211_beacon_add_tim(struct ieee80211_sub_if_data *sdata,
2222 				     struct ieee80211_if_ap *bss,
2223 				     struct sk_buff *skb,
2224 				     struct beacon_data *beacon)
2225 {
2226 	u8 *pos, *tim;
2227 	int aid0 = 0;
2228 	int i, have_bits = 0, n1, n2;
2229 
2230 	/* Generate bitmap for TIM only if there are any STAs in power save
2231 	 * mode. */
2232 	if (atomic_read(&bss->num_sta_ps) > 0)
2233 		/* in the hope that this is faster than
2234 		 * checking byte-for-byte */
2235 		have_bits = !bitmap_empty((unsigned long*)bss->tim,
2236 					  IEEE80211_MAX_AID+1);
2237 
2238 	if (bss->dtim_count == 0)
2239 		bss->dtim_count = sdata->vif.bss_conf.dtim_period - 1;
2240 	else
2241 		bss->dtim_count--;
2242 
2243 	tim = pos = (u8 *) skb_put(skb, 6);
2244 	*pos++ = WLAN_EID_TIM;
2245 	*pos++ = 4;
2246 	*pos++ = bss->dtim_count;
2247 	*pos++ = sdata->vif.bss_conf.dtim_period;
2248 
2249 	if (bss->dtim_count == 0 && !skb_queue_empty(&bss->ps_bc_buf))
2250 		aid0 = 1;
2251 
2252 	bss->dtim_bc_mc = aid0 == 1;
2253 
2254 	if (have_bits) {
2255 		/* Find largest even number N1 so that bits numbered 1 through
2256 		 * (N1 x 8) - 1 in the bitmap are 0 and number N2 so that bits
2257 		 * (N2 + 1) x 8 through 2007 are 0. */
2258 		n1 = 0;
2259 		for (i = 0; i < IEEE80211_MAX_TIM_LEN; i++) {
2260 			if (bss->tim[i]) {
2261 				n1 = i & 0xfe;
2262 				break;
2263 			}
2264 		}
2265 		n2 = n1;
2266 		for (i = IEEE80211_MAX_TIM_LEN - 1; i >= n1; i--) {
2267 			if (bss->tim[i]) {
2268 				n2 = i;
2269 				break;
2270 			}
2271 		}
2272 
2273 		/* Bitmap control */
2274 		*pos++ = n1 | aid0;
2275 		/* Part Virt Bitmap */
2276 		skb_put(skb, n2 - n1);
2277 		memcpy(pos, bss->tim + n1, n2 - n1 + 1);
2278 
2279 		tim[1] = n2 - n1 + 4;
2280 	} else {
2281 		*pos++ = aid0; /* Bitmap control */
2282 		*pos++ = 0; /* Part Virt Bitmap */
2283 	}
2284 }
2285 
2286 struct sk_buff *ieee80211_beacon_get_tim(struct ieee80211_hw *hw,
2287 					 struct ieee80211_vif *vif,
2288 					 u16 *tim_offset, u16 *tim_length)
2289 {
2290 	struct ieee80211_local *local = hw_to_local(hw);
2291 	struct sk_buff *skb = NULL;
2292 	struct ieee80211_tx_info *info;
2293 	struct ieee80211_sub_if_data *sdata = NULL;
2294 	struct ieee80211_if_ap *ap = NULL;
2295 	struct beacon_data *beacon;
2296 	struct ieee80211_supported_band *sband;
2297 	enum ieee80211_band band = local->hw.conf.channel->band;
2298 	struct ieee80211_tx_rate_control txrc;
2299 
2300 	sband = local->hw.wiphy->bands[band];
2301 
2302 	rcu_read_lock();
2303 
2304 	sdata = vif_to_sdata(vif);
2305 
2306 	if (!ieee80211_sdata_running(sdata))
2307 		goto out;
2308 
2309 	if (tim_offset)
2310 		*tim_offset = 0;
2311 	if (tim_length)
2312 		*tim_length = 0;
2313 
2314 	if (sdata->vif.type == NL80211_IFTYPE_AP) {
2315 		ap = &sdata->u.ap;
2316 		beacon = rcu_dereference(ap->beacon);
2317 		if (beacon) {
2318 			/*
2319 			 * headroom, head length,
2320 			 * tail length and maximum TIM length
2321 			 */
2322 			skb = dev_alloc_skb(local->tx_headroom +
2323 					    beacon->head_len +
2324 					    beacon->tail_len + 256);
2325 			if (!skb)
2326 				goto out;
2327 
2328 			skb_reserve(skb, local->tx_headroom);
2329 			memcpy(skb_put(skb, beacon->head_len), beacon->head,
2330 			       beacon->head_len);
2331 
2332 			/*
2333 			 * Not very nice, but we want to allow the driver to call
2334 			 * ieee80211_beacon_get() as a response to the set_tim()
2335 			 * callback. That, however, is already invoked under the
2336 			 * sta_lock to guarantee consistent and race-free update
2337 			 * of the tim bitmap in mac80211 and the driver.
2338 			 */
2339 			if (local->tim_in_locked_section) {
2340 				ieee80211_beacon_add_tim(sdata, ap, skb,
2341 							 beacon);
2342 			} else {
2343 				unsigned long flags;
2344 
2345 				spin_lock_irqsave(&local->tim_lock, flags);
2346 				ieee80211_beacon_add_tim(sdata, ap, skb,
2347 							 beacon);
2348 				spin_unlock_irqrestore(&local->tim_lock, flags);
2349 			}
2350 
2351 			if (tim_offset)
2352 				*tim_offset = beacon->head_len;
2353 			if (tim_length)
2354 				*tim_length = skb->len - beacon->head_len;
2355 
2356 			if (beacon->tail)
2357 				memcpy(skb_put(skb, beacon->tail_len),
2358 				       beacon->tail, beacon->tail_len);
2359 		} else
2360 			goto out;
2361 	} else if (sdata->vif.type == NL80211_IFTYPE_ADHOC) {
2362 		struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
2363 		struct ieee80211_hdr *hdr;
2364 		struct sk_buff *presp = rcu_dereference(ifibss->presp);
2365 
2366 		if (!presp)
2367 			goto out;
2368 
2369 		skb = skb_copy(presp, GFP_ATOMIC);
2370 		if (!skb)
2371 			goto out;
2372 
2373 		hdr = (struct ieee80211_hdr *) skb->data;
2374 		hdr->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
2375 						 IEEE80211_STYPE_BEACON);
2376 	} else if (ieee80211_vif_is_mesh(&sdata->vif)) {
2377 		struct ieee80211_mgmt *mgmt;
2378 		u8 *pos;
2379 		int hdr_len = offsetof(struct ieee80211_mgmt, u.beacon) +
2380 			      sizeof(mgmt->u.beacon);
2381 
2382 #ifdef CONFIG_MAC80211_MESH
2383 		if (!sdata->u.mesh.mesh_id_len)
2384 			goto out;
2385 #endif
2386 
2387 		skb = dev_alloc_skb(local->tx_headroom +
2388 				    hdr_len +
2389 				    2 + /* NULL SSID */
2390 				    2 + 8 + /* supported rates */
2391 				    2 + 3 + /* DS params */
2392 				    2 + (IEEE80211_MAX_SUPP_RATES - 8) +
2393 				    2 + sizeof(struct ieee80211_ht_cap) +
2394 				    2 + sizeof(struct ieee80211_ht_info) +
2395 				    2 + sdata->u.mesh.mesh_id_len +
2396 				    2 + sizeof(struct ieee80211_meshconf_ie) +
2397 				    sdata->u.mesh.ie_len);
2398 		if (!skb)
2399 			goto out;
2400 
2401 		skb_reserve(skb, local->hw.extra_tx_headroom);
2402 		mgmt = (struct ieee80211_mgmt *) skb_put(skb, hdr_len);
2403 		memset(mgmt, 0, hdr_len);
2404 		mgmt->frame_control =
2405 		    cpu_to_le16(IEEE80211_FTYPE_MGMT | IEEE80211_STYPE_BEACON);
2406 		memset(mgmt->da, 0xff, ETH_ALEN);
2407 		memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
2408 		memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN);
2409 		mgmt->u.beacon.beacon_int =
2410 			cpu_to_le16(sdata->vif.bss_conf.beacon_int);
2411 		mgmt->u.beacon.capab_info |= cpu_to_le16(
2412 			sdata->u.mesh.security ? WLAN_CAPABILITY_PRIVACY : 0);
2413 
2414 		pos = skb_put(skb, 2);
2415 		*pos++ = WLAN_EID_SSID;
2416 		*pos++ = 0x0;
2417 
2418 		if (ieee80211_add_srates_ie(&sdata->vif, skb) ||
2419 		    mesh_add_ds_params_ie(skb, sdata) ||
2420 		    ieee80211_add_ext_srates_ie(&sdata->vif, skb) ||
2421 		    mesh_add_rsn_ie(skb, sdata) ||
2422 		    mesh_add_ht_cap_ie(skb, sdata) ||
2423 		    mesh_add_ht_info_ie(skb, sdata) ||
2424 		    mesh_add_meshid_ie(skb, sdata) ||
2425 		    mesh_add_meshconf_ie(skb, sdata) ||
2426 		    mesh_add_vendor_ies(skb, sdata)) {
2427 			pr_err("o11s: couldn't add ies!\n");
2428 			goto out;
2429 		}
2430 	} else {
2431 		WARN_ON(1);
2432 		goto out;
2433 	}
2434 
2435 	info = IEEE80211_SKB_CB(skb);
2436 
2437 	info->flags |= IEEE80211_TX_INTFL_DONT_ENCRYPT;
2438 	info->flags |= IEEE80211_TX_CTL_NO_ACK;
2439 	info->band = band;
2440 
2441 	memset(&txrc, 0, sizeof(txrc));
2442 	txrc.hw = hw;
2443 	txrc.sband = sband;
2444 	txrc.bss_conf = &sdata->vif.bss_conf;
2445 	txrc.skb = skb;
2446 	txrc.reported_rate.idx = -1;
2447 	txrc.rate_idx_mask = sdata->rc_rateidx_mask[band];
2448 	if (txrc.rate_idx_mask == (1 << sband->n_bitrates) - 1)
2449 		txrc.max_rate_idx = -1;
2450 	else
2451 		txrc.max_rate_idx = fls(txrc.rate_idx_mask) - 1;
2452 	memcpy(txrc.rate_idx_mcs_mask, sdata->rc_rateidx_mcs_mask[band],
2453 	       sizeof(txrc.rate_idx_mcs_mask));
2454 	txrc.bss = true;
2455 	rate_control_get_rate(sdata, NULL, &txrc);
2456 
2457 	info->control.vif = vif;
2458 
2459 	info->flags |= IEEE80211_TX_CTL_CLEAR_PS_FILT |
2460 			IEEE80211_TX_CTL_ASSIGN_SEQ |
2461 			IEEE80211_TX_CTL_FIRST_FRAGMENT;
2462  out:
2463 	rcu_read_unlock();
2464 	return skb;
2465 }
2466 EXPORT_SYMBOL(ieee80211_beacon_get_tim);
2467 
2468 struct sk_buff *ieee80211_proberesp_get(struct ieee80211_hw *hw,
2469 					struct ieee80211_vif *vif)
2470 {
2471 	struct ieee80211_if_ap *ap = NULL;
2472 	struct sk_buff *presp = NULL, *skb = NULL;
2473 	struct ieee80211_hdr *hdr;
2474 	struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
2475 
2476 	if (sdata->vif.type != NL80211_IFTYPE_AP)
2477 		return NULL;
2478 
2479 	rcu_read_lock();
2480 
2481 	ap = &sdata->u.ap;
2482 	presp = rcu_dereference(ap->probe_resp);
2483 	if (!presp)
2484 		goto out;
2485 
2486 	skb = skb_copy(presp, GFP_ATOMIC);
2487 	if (!skb)
2488 		goto out;
2489 
2490 	hdr = (struct ieee80211_hdr *) skb->data;
2491 	memset(hdr->addr1, 0, sizeof(hdr->addr1));
2492 
2493 out:
2494 	rcu_read_unlock();
2495 	return skb;
2496 }
2497 EXPORT_SYMBOL(ieee80211_proberesp_get);
2498 
2499 struct sk_buff *ieee80211_pspoll_get(struct ieee80211_hw *hw,
2500 				     struct ieee80211_vif *vif)
2501 {
2502 	struct ieee80211_sub_if_data *sdata;
2503 	struct ieee80211_if_managed *ifmgd;
2504 	struct ieee80211_pspoll *pspoll;
2505 	struct ieee80211_local *local;
2506 	struct sk_buff *skb;
2507 
2508 	if (WARN_ON(vif->type != NL80211_IFTYPE_STATION))
2509 		return NULL;
2510 
2511 	sdata = vif_to_sdata(vif);
2512 	ifmgd = &sdata->u.mgd;
2513 	local = sdata->local;
2514 
2515 	skb = dev_alloc_skb(local->hw.extra_tx_headroom + sizeof(*pspoll));
2516 	if (!skb)
2517 		return NULL;
2518 
2519 	skb_reserve(skb, local->hw.extra_tx_headroom);
2520 
2521 	pspoll = (struct ieee80211_pspoll *) skb_put(skb, sizeof(*pspoll));
2522 	memset(pspoll, 0, sizeof(*pspoll));
2523 	pspoll->frame_control = cpu_to_le16(IEEE80211_FTYPE_CTL |
2524 					    IEEE80211_STYPE_PSPOLL);
2525 	pspoll->aid = cpu_to_le16(ifmgd->aid);
2526 
2527 	/* aid in PS-Poll has its two MSBs each set to 1 */
2528 	pspoll->aid |= cpu_to_le16(1 << 15 | 1 << 14);
2529 
2530 	memcpy(pspoll->bssid, ifmgd->bssid, ETH_ALEN);
2531 	memcpy(pspoll->ta, vif->addr, ETH_ALEN);
2532 
2533 	return skb;
2534 }
2535 EXPORT_SYMBOL(ieee80211_pspoll_get);
2536 
2537 struct sk_buff *ieee80211_nullfunc_get(struct ieee80211_hw *hw,
2538 				       struct ieee80211_vif *vif)
2539 {
2540 	struct ieee80211_hdr_3addr *nullfunc;
2541 	struct ieee80211_sub_if_data *sdata;
2542 	struct ieee80211_if_managed *ifmgd;
2543 	struct ieee80211_local *local;
2544 	struct sk_buff *skb;
2545 
2546 	if (WARN_ON(vif->type != NL80211_IFTYPE_STATION))
2547 		return NULL;
2548 
2549 	sdata = vif_to_sdata(vif);
2550 	ifmgd = &sdata->u.mgd;
2551 	local = sdata->local;
2552 
2553 	skb = dev_alloc_skb(local->hw.extra_tx_headroom + sizeof(*nullfunc));
2554 	if (!skb)
2555 		return NULL;
2556 
2557 	skb_reserve(skb, local->hw.extra_tx_headroom);
2558 
2559 	nullfunc = (struct ieee80211_hdr_3addr *) skb_put(skb,
2560 							  sizeof(*nullfunc));
2561 	memset(nullfunc, 0, sizeof(*nullfunc));
2562 	nullfunc->frame_control = cpu_to_le16(IEEE80211_FTYPE_DATA |
2563 					      IEEE80211_STYPE_NULLFUNC |
2564 					      IEEE80211_FCTL_TODS);
2565 	memcpy(nullfunc->addr1, ifmgd->bssid, ETH_ALEN);
2566 	memcpy(nullfunc->addr2, vif->addr, ETH_ALEN);
2567 	memcpy(nullfunc->addr3, ifmgd->bssid, ETH_ALEN);
2568 
2569 	return skb;
2570 }
2571 EXPORT_SYMBOL(ieee80211_nullfunc_get);
2572 
2573 struct sk_buff *ieee80211_probereq_get(struct ieee80211_hw *hw,
2574 				       struct ieee80211_vif *vif,
2575 				       const u8 *ssid, size_t ssid_len,
2576 				       const u8 *ie, size_t ie_len)
2577 {
2578 	struct ieee80211_sub_if_data *sdata;
2579 	struct ieee80211_local *local;
2580 	struct ieee80211_hdr_3addr *hdr;
2581 	struct sk_buff *skb;
2582 	size_t ie_ssid_len;
2583 	u8 *pos;
2584 
2585 	sdata = vif_to_sdata(vif);
2586 	local = sdata->local;
2587 	ie_ssid_len = 2 + ssid_len;
2588 
2589 	skb = dev_alloc_skb(local->hw.extra_tx_headroom + sizeof(*hdr) +
2590 			    ie_ssid_len + ie_len);
2591 	if (!skb)
2592 		return NULL;
2593 
2594 	skb_reserve(skb, local->hw.extra_tx_headroom);
2595 
2596 	hdr = (struct ieee80211_hdr_3addr *) skb_put(skb, sizeof(*hdr));
2597 	memset(hdr, 0, sizeof(*hdr));
2598 	hdr->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
2599 					 IEEE80211_STYPE_PROBE_REQ);
2600 	memset(hdr->addr1, 0xff, ETH_ALEN);
2601 	memcpy(hdr->addr2, vif->addr, ETH_ALEN);
2602 	memset(hdr->addr3, 0xff, ETH_ALEN);
2603 
2604 	pos = skb_put(skb, ie_ssid_len);
2605 	*pos++ = WLAN_EID_SSID;
2606 	*pos++ = ssid_len;
2607 	if (ssid)
2608 		memcpy(pos, ssid, ssid_len);
2609 	pos += ssid_len;
2610 
2611 	if (ie) {
2612 		pos = skb_put(skb, ie_len);
2613 		memcpy(pos, ie, ie_len);
2614 	}
2615 
2616 	return skb;
2617 }
2618 EXPORT_SYMBOL(ieee80211_probereq_get);
2619 
2620 void ieee80211_rts_get(struct ieee80211_hw *hw, struct ieee80211_vif *vif,
2621 		       const void *frame, size_t frame_len,
2622 		       const struct ieee80211_tx_info *frame_txctl,
2623 		       struct ieee80211_rts *rts)
2624 {
2625 	const struct ieee80211_hdr *hdr = frame;
2626 
2627 	rts->frame_control =
2628 	    cpu_to_le16(IEEE80211_FTYPE_CTL | IEEE80211_STYPE_RTS);
2629 	rts->duration = ieee80211_rts_duration(hw, vif, frame_len,
2630 					       frame_txctl);
2631 	memcpy(rts->ra, hdr->addr1, sizeof(rts->ra));
2632 	memcpy(rts->ta, hdr->addr2, sizeof(rts->ta));
2633 }
2634 EXPORT_SYMBOL(ieee80211_rts_get);
2635 
2636 void ieee80211_ctstoself_get(struct ieee80211_hw *hw, struct ieee80211_vif *vif,
2637 			     const void *frame, size_t frame_len,
2638 			     const struct ieee80211_tx_info *frame_txctl,
2639 			     struct ieee80211_cts *cts)
2640 {
2641 	const struct ieee80211_hdr *hdr = frame;
2642 
2643 	cts->frame_control =
2644 	    cpu_to_le16(IEEE80211_FTYPE_CTL | IEEE80211_STYPE_CTS);
2645 	cts->duration = ieee80211_ctstoself_duration(hw, vif,
2646 						     frame_len, frame_txctl);
2647 	memcpy(cts->ra, hdr->addr1, sizeof(cts->ra));
2648 }
2649 EXPORT_SYMBOL(ieee80211_ctstoself_get);
2650 
2651 struct sk_buff *
2652 ieee80211_get_buffered_bc(struct ieee80211_hw *hw,
2653 			  struct ieee80211_vif *vif)
2654 {
2655 	struct ieee80211_local *local = hw_to_local(hw);
2656 	struct sk_buff *skb = NULL;
2657 	struct ieee80211_tx_data tx;
2658 	struct ieee80211_sub_if_data *sdata;
2659 	struct ieee80211_if_ap *bss = NULL;
2660 	struct beacon_data *beacon;
2661 	struct ieee80211_tx_info *info;
2662 
2663 	sdata = vif_to_sdata(vif);
2664 	bss = &sdata->u.ap;
2665 
2666 	rcu_read_lock();
2667 	beacon = rcu_dereference(bss->beacon);
2668 
2669 	if (sdata->vif.type != NL80211_IFTYPE_AP || !beacon || !beacon->head)
2670 		goto out;
2671 
2672 	if (bss->dtim_count != 0 || !bss->dtim_bc_mc)
2673 		goto out; /* send buffered bc/mc only after DTIM beacon */
2674 
2675 	while (1) {
2676 		skb = skb_dequeue(&bss->ps_bc_buf);
2677 		if (!skb)
2678 			goto out;
2679 		local->total_ps_buffered--;
2680 
2681 		if (!skb_queue_empty(&bss->ps_bc_buf) && skb->len >= 2) {
2682 			struct ieee80211_hdr *hdr =
2683 				(struct ieee80211_hdr *) skb->data;
2684 			/* more buffered multicast/broadcast frames ==> set
2685 			 * MoreData flag in IEEE 802.11 header to inform PS
2686 			 * STAs */
2687 			hdr->frame_control |=
2688 				cpu_to_le16(IEEE80211_FCTL_MOREDATA);
2689 		}
2690 
2691 		if (!ieee80211_tx_prepare(sdata, &tx, skb))
2692 			break;
2693 		dev_kfree_skb_any(skb);
2694 	}
2695 
2696 	info = IEEE80211_SKB_CB(skb);
2697 
2698 	tx.flags |= IEEE80211_TX_PS_BUFFERED;
2699 	tx.channel = local->hw.conf.channel;
2700 	info->band = tx.channel->band;
2701 
2702 	if (invoke_tx_handlers(&tx))
2703 		skb = NULL;
2704  out:
2705 	rcu_read_unlock();
2706 
2707 	return skb;
2708 }
2709 EXPORT_SYMBOL(ieee80211_get_buffered_bc);
2710 
2711 void ieee80211_tx_skb_tid(struct ieee80211_sub_if_data *sdata,
2712 			  struct sk_buff *skb, int tid)
2713 {
2714 	skb_set_mac_header(skb, 0);
2715 	skb_set_network_header(skb, 0);
2716 	skb_set_transport_header(skb, 0);
2717 
2718 	skb_set_queue_mapping(skb, ieee802_1d_to_ac[tid]);
2719 	skb->priority = tid;
2720 
2721 	/*
2722 	 * The other path calling ieee80211_xmit is from the tasklet,
2723 	 * and while we can handle concurrent transmissions locking
2724 	 * requirements are that we do not come into tx with bhs on.
2725 	 */
2726 	local_bh_disable();
2727 	ieee80211_xmit(sdata, skb);
2728 	local_bh_enable();
2729 }
2730